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Shanghai, China

Tongji University , colloquially known as Tongji , located in Shanghai, has more than 50,000 students and 8,000 staff members . It offers degree programs at both undergraduate and postgraduate levels. Established in 1907 by the German government together with German physicians in Shanghai, Tongji is one of the oldest and most prestigious universities in China. Among its various departments it is especially highly ranked in engineering, among which its architecture, urban planning and civil engineering departments have consistently ranked first in China for decades, and its automotive engineering, oceanography, environmental science, software engineering, German language departments are also ones of the best domestically. Wikipedia.

Tang O.,Linkoping University | Tang O.,Tongji University | Nurmaya Musa S.,Linkoping University | Nurmaya Musa S.,University of Malaya
International Journal of Production Economics | Year: 2011

The purpose of this paper is to investigate the research development in supply chain risk management (SCRM), which has shown an increasing global attention in recent years. Literature survey and citation/co-citation analysis are used to fulfil the research task. Literature survey has undertaken a thorough search of articles on selected journals relevant to supply chain operations management. Meanwhile, citation/co-citation analysis uses Web of Sciences database to disclose SCRM development between 1995 and 2009. Both the approaches show similar trends of rising publications over the past 15 years. This review has piloted us to identify and classify the potential risk associated with different flows, namely material, cash and information flows. Consequently, we identify some research gaps. Even though there is a pressing need and awareness of SCRM from industrial aspect, quantitative models in the field are relatively lacking and information flow risk has received less attention. It is also interesting to observe the evolutions and advancements of SCRM discipline. One finding is that the intellectual structure of the field made statistically significant increase during 20002005 and evolved from passively reacting to vague general issues of disruptions towards more proactively managing supply chain risk from system perspectives. © 2010 Elsevier B.V. All rights reserved.

Prognostics is much efficient to achieve zero-downtime performance, maximum productivity and proactive maintenance of machines. Prognostics intends to assess and predict the time evolution of machine health degradation so that machine failures can be predicted and prevented. A novel prognostics system is developed based on the data-model-fusion scheme using the Bayesian inference-based self-organizing map (SOM) and an integration of logistic regression (LR) and high-order particle filtering (HOPF). In this prognostics system, a baseline SOM is constructed to model the data distribution space of healthy machine under an assumption that predictable fault patterns are not available. Bayesian inference-based probability (BIP) derived from the baseline SOM is developed as a quantification indication of machine health degradation. BIP is capable of offering failure probability for the monitored machine, which has intuitionist explanation related to health degradation state. Based on those historic BIPs, the constructed LR and its modeling noise constitute a high-order Markov process (HOMP) to describe machine health propagation. HOPF is used to solve the HOMP estimation to predict the evolution of the machine health in the form of a probability density function (PDF). An on-line model update scheme is developed to adapt the Markov process changes to machine health dynamics quickly. The experimental results on a bearing test-bed illustrate the potential applications of the proposed system as an effective and simple tool for machine health prognostics. © 2015 Elsevier Ltd.

Chen X.F.,Tongji University
Genetics and molecular research : GMR | Year: 2012

Recent studies have shown that 5p15.33 is one of the chromosomal regions that is most consistently altered in lung cancer; common variants that are located in this region have been genotyped in various populations. However, the genetic contribution of these variants to carcinogenesis is relatively unknown. A clinic-based case-control study in Shanghai was undertaken on 196 patients with lung cancer and 229 healthy individuals. TERT rs2736100 and CLPTM1L rs401681 and rs402710 were genotyped using the ABI TaqMan Allelic Discrimination assay. For rs2736100, the G variant and the GG genotype were more frequent, whereas the TT genotype was less frequent in patients with lung adenocarcinoma than in controls. The CT genotype at rs401681 was more common and the TT genotype was rare in patients, and the differences were significant between lung adenocarcinoma patients and controls. This was also true for rs402710. Moreover, the frequency of the GGCTCT haplotype was higher and the TTTTTT frequency was lower in patients, especially those with lung adenocarcinoma. Aberrant linkage disequilibrium among the three SNPs was found in patients with lung adenocarcinoma. We conclude that multiple variants at 5p15.33 contribute to susceptibility to lung adenocarcinoma.

Zhao L.,CAS Institute of Geology and Geophysics | Xue M.,Tongji University
Geochemistry, Geophysics, Geosystems | Year: 2010

We investigate the mantle flow pattern and geodynamic cause of North China Craton (NCC) reactivation using shear wave splitting measurements from 140 broadband stations. Using a newly developed method for simulating wave propagation in a two-dimensional anisotropic medium, we first examined the influence of sedimentary structures on SKS splitting measurements. The simulations show that a sedimentary layer, whether isotropic or anisotropic, significantly influences the waveform; however, the shear wave splitting parameters can be retrieved with negligible errors. As a result, this study included new splitting measurements at stations which were deployed within basins and not used previously. Among 121 broadband stations that contribute valid splitting results, 55 stations are newly added which were deployed within basins. This significantly improved the sampling coverage on the NCC. The complicated spatial patterns of the splitting parameters indicate that complex upper mantle deformation has occurred in the NCC. To obtain both deep kinematic and geometric information, we interpret our splitting measurements in the context of new high-resolution tomographic results for the NCC. By comparing our observations with three end-member conceptual models (upwelling, wedge flow, and lithospheric delamination), we found that the observed anisotropy pattern beneath the NCC is not completely consistent with any of them. Thus, we prefer a hybrid mantle flow model, where the subduction of the Pacific Plate causes a mantle wedge flow beneath the eastern Archean block and a regional upwelling beneath the central block which has been imaged as a low velocity anomaly in seismic tomography. Thus we speculate that the subduction of the Pacific Plate, compared to the NCC-Yangtze Craton amalgamation and the India-Eurasian collision, is most likely the geodynamic cause of the reactivation of the NCC eastern block during the Late Mesozoic to Cenozoic. Copyright 2010 by the American Geophysical Union.

Xing K.,Xian Jiaotong University | Han L.,Xian Jiaotong University | Zhou M.,Tongji University | Zhou M.,New Jersey Institute of Technology | Wang F.,Xian Jiaotong University
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2012

Deadlock-free control and scheduling are vital for optimizing the performance of automated manufacturing systems (AMSs) with shared resources and route flexibility. Based on the Petri net models of AMSs, this paper embeds the optimal deadlock avoidance policy into the genetic algorithm and develops a novel deadlock-free genetic scheduling algorithm for AMSs. A possible solution of the scheduling problem is coded as a chromosome representation that is a permutation with repetition of parts. By using the one-step look-ahead method in the optimal deadlock control policy, the feasibility of a chromosome is checked, and infeasible chromosomes are amended into feasible ones, which can be easily decoded into a feasible deadlock-free schedule. The chromosome representation and polynomial complexity of checking and amending procedures together support the cooperative aspect of genetic search for scheduling problems strongly. © 2012 IEEE.

Hu D.,Fudan University | He L.,Tongji University | Wang X.,Columbia University
IEEE Transactions on Wireless Communications | Year: 2011

In orthogonal frequency-division multiplexing (OFDM)-based cognitive radio (CR) systems, the subcarriers already occupied by the primary users cannot be used by the secondary users. This leads to possibly non-contiguous positions of the available subcarriers for the secondary users. The conventional pilot design methods are no longer effective for such systems. In this paper, we propose a new practical pilot design method for OFDM-based CR systems. We first formulate the pilot design as a new optimization problem. Instead of minimizing the mean-square error (MSE) of the least-squares (LS) channel estimator, we minimize an upper bound which is related to this MSE. We then propose an efficient scheme to solve the optimization problem. Specifically, the pilot indices are obtained sequentially by solving a series of one-dimensional optimization problems of significantly lower complexity. The computational complexity of the proposed scheme is low since it only involves real additions. Simulation results show that the pilot index sequences obtained by the proposed method exhibit significantly better performance than those obtained by existing pilot design methods. © 2011 IEEE.

Shang Y.,Tongji University
Networks and Heterogeneous Media | Year: 2014

This paper addresses group consensus problems in generic linear multi-agent systems with directed information flow over (i) fixed topology and (ii) randomly switching topology governed by a continuous-time homogeneous Markov process. We propose two types of pinning control protocols to ensure group consensus regardless of the magnitude of the coupling strengths among the agents. In the case of randomly switching topology, we show that the group consensus behavior is unrelated to the magnitude of the couplings among agents if the union of the topologies corresponding to the positive recurrent states of the Markov process possesses an acyclic partition. Sufficient conditions for achieving group consensus are presented in terms of simple graphic conditions, which are easy to be checked compared to conventional algebraic criteria. Simulation examples are also presented to validate the effectiveness of the theoretical results. © American Institute of Mathematical Sciences.

Hepatocellular carcinoma (HCC) is one of the most fatal cancers in the world, and metastasis is a significant cause to the high mortality in patients with HCC. However, the molecular mechanism behind HCC metastasis is not fully understood. Study of regulatory networks may help investigate HCC metastasis in the way of systems biology profiling. By utilizing both sequence information and parallel microRNA(miRNA) and mRNA expression data on the same cohort of HBV related HCC patients without or with venous metastasis, we constructed combinatorial regulatory networks of non-metastatic and metastatic HCC which contain transcription factor(TF) regulation and miRNA regulation. Differential regulation patterns, classifying marker modules, and key regulatory miRNAs were analyzed by comparing non-metastatic and metastatic networks. Globally TFs accounted for the main part of regulation while miRNAs for the minor part of regulation. However miRNAs displayed a more active role in the metastatic network than in the non-metastatic one. Seventeen differential regulatory modules discriminative of the metastatic status were identified as cumulative-module classifier, which could also distinguish survival time. MiR-16, miR-30a, Let-7e and miR-204 were identified as key miRNA regulators contributed to HCC metastasis. In this work we demonstrated an integrative approach to conduct differential combinatorial regulatory network analysis in the specific context venous metastasis of HBV-HCC. Our results proposed possible transcriptional regulatory patterns underlying the different metastatic subgroups of HCC. The workflow in this study can be applied in similar context of cancer research and could also be extended to other clinical topics.

Ke S.-H.,Tongji University | Ke S.-H.,Beijing Computational Science Research Center
Physical Review B - Condensed Matter and Materials Physics | Year: 2011

An efficient all-electron G0W0 method and a quasiparticle self-consistent GW (QSGW) method for molecules are proposed in the molecular-orbital space with the full random-phase approximation. The convergence with the basis set is examined. As an application, the ionization energy and electron affinity of a series of conjugated molecules (up to 32 atoms) are calculated and compared to the experiment. The QSGW result improves the G0W0 result and both of them are in significantly better agreement with experimental data than those from Hartree-Fock (HF) and hybrid density-functional calculations, especially for electron affinity. The nearly correct energy gap and suppressed self-interaction error by the HF exchange make our method a good candidate for investigating electronic and transport properties of molecular systems. © 2011 American Physical Society.

Yuan F.,Tongji University
Applied Immunohistochemistry and Molecular Morphology | Year: 2015

We optimized methanol treatment in paraformaldehyde-fixed slices for immunofluorescent staining of ependymal basal bodies in brain ventricles. As 100% methanol induced severe deformations to the slices (including rolling and folding over), we tried to decrease methanol concentration. We found that 33.3% to 75% methanol could result in ideal immunostaining of basal bodies without inducing obvious deformations. Instead of treating slices at −20°C (without proper cryoprotection measurements) as suggested in previous studies, we carried out methanol treatment at room temperature. Our modified protocol can not only raise immunostaining efficiency in tissue slices, it may also prevent potential freezing damages to the samples.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/4.0. Copyright 2015 Wolters Kluwer Health, Inc. All rights reserved.

Huang Y.-S.,National Ilan University | Pan Y.-L.,Air force Institute of Technology Taiwan | Zhou M.,Tongji University | Zhou M.,New Jersey Institute of Technology
IEEE Transactions on Systems, Man, and Cybernetics Part A:Systems and Humans | Year: 2012

Deadlock prevention, deadlock detection, and deadlock avoidance strategies are used to solve the deadlock problems of flexible manufacturing systems. The theory of regions is recognized as the unique method for obtaining maximally permissive (i.e., optimal) controllers in the existing literature. All legal and live maximal behavior of a Petri net model can be preserved by using a marking/transition-separation instance (MTSI). However, obtaining them is an extremely time consuming problem. This work proposes crucial MTSIs that allow designers to employ much fewer MTSIs to deal with deadlocks. The advantage of the proposed policy is that an optimal deadlock controller can be obtained with drastically reduced computation. Experimental results, by varying the markings of given net structures, indicate that it is the most efficient policy to obtain such controllers. © 2011 IEEE.

Zhang X.,Tongji University | Van Wee B.,Technical University of Delft
Engineering Optimization | Year: 2012

In previous studies of congestion pricing, the objective was to minimize total travel time or maximize total social welfare of all travellers in transportation networks. In this article, a new objective function of maximizing the reserve capacity of networks is proposed, and a new bi-level model is formulated for the implementation of congestion pricing, where either link tolls or path tolls are charged. Since the bi-level model is neither convex nor differentiable, the traditional gradient based methods cannot solve the problem for a global optimum. To circumvent the difficulty of computing, the congestion pricing problem of simultaneous toll link and toll level optimization is formulated as a single-level optimization program with equilibrium constraints. Then the equilibrium constraints, the travel time functions, and toll location constraints are all linearized by introducing mixed integer variables. As a result, the overall problem is formulated into a mixed-integer linear program, which can determine the global optimum. Numerical results show that this approach is effective and efficient. © 2012 Copyright Taylor and Francis Group, LLC.

Zhang L.,Tongji University
Molecular and cellular biochemistry | Year: 2012

Cell migration plays major roles in human breast cancer-related death, but the molecular mechanisms remain unclear. Valproic acid (VPA) is a broad-spectrum inhibitor of class I and II histone deacetylases and shows great anticancer activity in a variety of human cancers including breast cancer. In this study, we found that VPA significantly inhibited cell migration but not proliferation of human breast cancer MDA-MB-231 cells. Mechanistic studies found that VPA significantly inhibited the expression of Survivin. Knockdown of Survivin could obviously inhibited cell migration, while over-expression of Survivin markedly rescued the inhibition of VPA on cell migration. Further studies found that knockdown of HDAC2 completely mimicked the effects of VPA on Survivin and cell migration, and over-expression of Survivin could also rescue the effects of HDAC2 knockdown on cell migration. Collectively, these results indicated that HDAC2 may be the specific target of VPA in breast cancer cells, and specific inhibition of HDAC2, especially by small molecular chemicals may lead to less side-effects and provide a better strategy than VPA application for human breast cancer treatment.

Zhou F.,Tongji University | Young B.,University of Hong Kong
Engineering Structures | Year: 2013

This paper reports a numerical investigation of cold-formed high strength stainless steel square and rectangular hollow sections subjected to web crippling at elevated temperatures. Finite element analysis was conducted on cold-formed high strength austenitic and duplex stainless steel material. Four loading conditions specified in the American Specification and Australian/New Zealand Standard for cold-formed stainless steel structures were investigated in the numerical study. A non-linear finite element model which includes geometric and material non-linearities was developed and verified against experimental results. It was shown that the finite element model closely predicted the web crippling strengths and failure modes of the tested specimens under the four loading conditions. Hence, parametric study was carried out to investigate the web crippling behaviour of cold-formed high strength stainless steel square and rectangular hollow sections at elevated temperatures. The web crippling strengths predicted from the finite element analysis were compared with the design strengths obtained using the American, Australian/New Zealand and European specifications for stainless steel structures by substituting the reduced material properties in the current web crippling design equations. A unified web crippling equation for cold-formed high strength stainless steel square and rectangular hollow sections at elevated temperatures is proposed. It is demonstrated that the web crippling strength obtained using the proposed equation is safe and reliable using reliability analysis. © 2013 Elsevier Ltd.

Li P.,Tongji University
Differential Geometry and its Application | Year: 2016

Given a compatible vector field on a compact connected almost-complex manifold, we show in this article that the multiplicities of eigenvalues among the zero point set of this vector field have intimate relations. We highlight a special case of our result and reinterpret it as a vanishing-type result in the framework of the celebrated Atiyah-Bott-Singer localization formula. This new point of view, via the Chern-Weil theory and a strengthened version of Bott's residue formula, can lead to an obstruction to Killing real holomorphic vector fields on compact Hermitian manifolds in terms of a curvature integral. © 2015 Elsevier B.V.

Zhu H.,Nipissing University | Zhou M.,Tongji University
IEEE Transactions on Systems, Man, and Cybernetics Part A:Systems and Humans | Year: 2012

Many-to-Many (M-M) role transfers are generalized problems that are encountered in collaboration. Exhaustive-search-based algorithms are too computationally intensive. This paper introduces the Kuhn-Munkres (or Hungarian) algorithm for the general assignment problems (GAPs) and proposes a new efficient algorithm to solve the M-M role transfer problems by converting them to the GAPs. The experiments and results validate the proposed algorithms. © 2011 IEEE.

Du J.,Tongji University | Du J.,University of Sheffield | Armes S.P.,University of Sheffield
Soft Matter | Year: 2010

Patchy multi-compartment micelles are formed on direct dissolution of a primary amine-based triblock copolymer, poly(ethylene oxide)-b-poly(ε- caprolactone)-b-poly(2-aminoethyl methacrylate), PEO-b-PCL-b-PAMA, in water, with PCL chains forming the micelle cores and the PEO and PAMA chains forming phase-segregated patchy or hemispherical coronas. By selectively silicifying the PCL cores with tetramethyl orthosilicate (TMOS), the phase-separated character of these micelles is revealed by transmission electron microscopy. © 2010 The Royal Society of Chemistry.

Liu X.,Key Laboratory of Embedded System and Service Computing | Liu X.,Tongji University | Lu W.,Fudan University | Chen T.,Fudan University
IEEE Transactions on Automatic Control | Year: 2010

In this note, the consensus problem with infinite time-varying delays for linearly coupled static network is investigated. The delay affects only the off-diagonal terms in continuous-time equations. At first, we define an effective consensus ability index. Then, by using the graph theory and a new concept of consensus, we prove that under some mild conditions, the network can realize consensus. An example is given to show the validity of obtained results. © 2010 IEEE.

Yang J.,University of Tokyo | Yang J.,Tongji University | Sasaki T.,University of Tokyo
Crystal Growth and Design | Year: 2010

Single-crystalline Co3O4 crystals such as spheres, nanocubes, and rhombododecahedrons were obtained hydrothermally by employing differently charged surfactants and solvents. On the basis of calculations (charge density, atom density, and dipolar moment) on involved charged crystal planes of {100} for the cubes and {110} for the rhombododecahedrons, we proposed that the specific interactions between changed capping agents and crystal planes Of Co3O4 led to the selective formation of cubes with {100} orientation and rhombododecahedrons with {110} orientation, respectively. It was also found that the intrinsic structure of charged planes affected possibly not only the crystallization processes and final morphologies of Co3O4 crystals but also the assembly behaviors Of Co3O4 particles. Being in a typical spinel structure, the crystallization habits of Co3O4 crystals based on intrinsic structure directed by capping agents are possibly extended to other crystal systems in a similar structure, to get an optimized synthetic strategy and product, which, as well, is helpful for understanding the interactions on the organic-inorganic interfaces in depth. © 2010 Amerioan Chemical Society.

Yao X.,Tongji University
Modern Tunnelling Technology | Year: 2014

As a basic means for finding the problems of operating metro tunnel, defect detection can provide evidence for the evaluation of relevant structural behavior and operation safety. Regarding the two common and critical defects of apparent defect and section deformation, it cannot meet the future safety requirements of metro by traditional detection technology for its low efficiency, long feedback time and large difference for the data obtained. This paper introduced the fundamentals and procedures of a new technology to rapidly detect the defects mentioned above, and presented its application effect in Shanghai metro tunnels. ©, 2015, Editorial Office of "Modern Tunnelling Technology". All right reserved.

Wang S.,Tongji University | Yu J.,Shanghai University
Computers and Industrial Engineering | Year: 2010

Most production scheduling problems, including the standard flexible job-shop scheduling problem (FJSP), assume that machines are continuously available. However, in most realistic situations, machines may become unavailable during certain periods due to preventive maintenance (PM). In this paper, a flexible job-shop scheduling problem with machine availability constraints is considered. Each machine is subject to preventive maintenance during the planning period and the starting times of maintenance activities are either flexible in a time window or fixed beforehand. Moreover, two cases of maintenance resource constraint are considered: sufficient maintenance resource available or only one maintenance resource available. To deal with this variant FJSP problem with maintenance activities, a filtered beam search (FBS) based heuristic algorithm is proposed. With a modified branching scheme, the machine availability constraint and maintenance resource constraint can be easily incorporated into the proposed algorithm. Simulation experiments are conducted on some representative problems. The results demonstrate that the proposed filtered beam search based heuristic algorithm is a viable and effective approach for the FJSP with maintenance activities. © 2010 Elsevier Ltd. All rights reserved.

Dong B.,University of Texas at San Antonio | O'Neill Z.,University of Alabama | Li Z.,Tongji University
Automation in Construction | Year: 2014

Although energy-efficient building technologies are emerging, a key challenge is how to effectively maintain building energy performance over the evolving lifecycle of the building. Field experience shows that energy savings of 5-30% are typically achievable simply by applying energy Fault Detection and Diagnostics (FDD) and correcting faults diagnosed in buildings. Model-based FDD in buildings is a challenging task, not only because the task itself is difficult, but also because the workflow and information exchange behind the task is very complex and error prone. This complexity arises from several aspects. Firstly, creating a baseline building energy performance model suitable for FDD is both time and labor consuming. Secondly, the FDD module typically has its own ad-hoc platform, and the integration of this platform with the existing Building Energy Management System (BEMS) is technically challenging due to the incompatible interoperability. Finally, the information exchange itself is complex due to the existence of multiple functioning modules to make FDD workflow happen. To perform an efficient and effective FDD with the BEMS in buildings, information is needed to flow among an as-built building static information module, a building energy performance simulation module, a building operational data acquisition module and a FDD module. In such a complex process, it is challenging to ensure the information integrity and consistence. In this paper, we propose a Building Information Modeling (BIM) enabled information infrastructure for FDD, which streamlines the information exchange process and therefore has the potential to improve the efficiency of similar works in practice. The proposed information infrastructure was deployed and implemented in a real building for a FDD case study.

To study the outcome of basicervical intertrochanteric fractures of the proximal femur treated with cephalomeduallary hip nails. The clinical outcomes of 32 cases of basicervical intertrochanteric fractures treated with cephalomeduallary hip nails from January 2008 to June 2010 were retrospectively reviewed and the progress of fracture healing and occurrence of complications recorded. The function of the hip joints was evaluated by the Harris social index 2 years postoperatively. Thirty patients were followed up until fracture union for at least 24 months. Twenty-seven fractures had healed with no loss of position by 12 months postoperatively; the remaining three had mild varus deformity of the hip joint. No patient had evidence of avascular necrosis of the femoral head. No cut out of the helical blade was visible on radiographs. The mean Harris score was 86.5 (75-96) two years postoperatively, 11 patients having excellent scores, 15 good and 4 fair. Closed reduction and proximal femur intramedullary nail fixation for basicervical intertrochanteric fractures provides stable fixation and allows early exercise. It appears to have excellent outcomes in the short and medium term. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Guo Y.,McMaster University | Liu S.,Tongji University | Baetz B.W.,McMaster University
Water Resources Research | Year: 2012

Many rainfall-runoff models consider only the infiltration excess runoff generation process. The use of green roofs, bio-retention areas, and pervious pavements for urban storm water management purposes requires the modeling of surfaces where both infiltration and saturation excess runoff generation mechanisms need to be considered. Expanded from previous results of probabilistic rainfall-runoff transformation, analytical equations transforming the input rainfall frequency distribution to output runoff frequency distribution are derived to incorporate both runoff generation processes. These analytical equations can be used to calculate the average annual runoff volume and runoff event volume return period. Results from deterministic continuous simulation of various urban surfaces were compared to those from the analytical equations and satisfactory agreement was obtained. The analytical equations are therefore proposed as a complement to continuous simulation models for the modeling of urban catchments where both runoff generation processes occur. © 2012 American Geophysical Union. All Rights Reserved.

Leung E.L.,Macau University of Science and Technology | Cao Z.-W.,Tongji University | Jiang Z.-W.,Macau University of Science and Technology | Zhou H.,Macau University of Science and Technology | Liu L.,Macau University of Science and Technology
Briefings in Bioinformatics | Year: 2013

Network-based intervention has been a trend of curing systemic diseases, but it relies on regimen optimization and valid multi-target actions of the drugs. The complex multi-component nature of medicinal herbs may serve as valuable resources for network-based multi-target drug discovery due to its potential treatment effects by synergy. Recently, robustness of multiple systems biology platforms shows powerful to uncover molecular mechanisms and connections between the drugs and their targeting dynamic network. However, optimization methods of drug combination are insufficient, owning to lacking of tighter integration across multiple '-omics' databases. The newly developed algorithm- or network-based computational models can tightly integrate '-omics' databases and optimize combinational regimens of drug development, which encourage using medicinal herbs to develop into new wave of network-based multi-target drugs. However, challenges on further integration across the databases of medicinal herbs with multiple system biology platforms for multi-target drug optimization remain to the uncertain reliability of individual data sets, width and depth and degree of standardization of herbal medicine. Standardization of the methodology and terminology of multiple system biology and herbal database would facilitate the integration. Enhance public accessible databases and the number of research using system biology platform on herbal medicine would be helpful. Further integration across various '-omics' platforms and computational tools would accelerate development of network-based drug discovery and network medicine. © The Author 2012. Published by Oxford University Press.

Jin Q.,Tongji University | Overend M.,University of Cambridge
Energy and Buildings | Year: 2014

Early-stage façade design is a complex and multi-objective process. There are two principal barriers in the process of identifying an optimal façade solution. Firstly, the number of design variables and their uncertainty are relatively large, making design decisions difficult. Secondly, each design variable is likely to affect several performance indicators simultaneously, which makes it difficult to quantify the impacts of the design variables. In this paper, we perform sensitivity analyses on two generic building scenarios (a cellular office room and an open-plan office floor) in three geographic locations (London, Helsinki, and Rome). A series of façade sensitivity coefficient charts for early-stage façade design are produced for these locations thereby providing quantitative relationships between a comprehensive list of design variables and façade performance indicators. The sensitivity coefficient charts provide a guide for allocating the limited design time and construction budget to the design variables that will generate the largest impact on facade performance. © 2014 Elsevier B.V.

Yu G.R.,Tongji University
Orthopaedic surgery | Year: 2013

To discuss the operative methods and curative effect of calcaneal tuberosity fracture. A retrospective study was done to analyze 15 patients with calcaneal tuberosity fracture who received surgical management between January 2008 and June 2011. There were nine males and six females, with the age ranging from 31 to 68 years (average, 51.4 years). All the patients had unilateral acute injury, with the left foot in 7 cases and the right foot in 8 cases. According to the Beavis classification, there were three cases in type I and 12 cases in type II. All the cases in type I and 10 cases in type II were treated with open reduction and screw fixation. The other two cases in type II with larger fragment involving a portion of the subtalar joint were treated with plate and screw fixation. The effect of the treatment was assessed according to the ankle and hindfoot score system of American Orthopaedic Foot and Ankle Society (AOFAS) after the operation. Ten patients were followed up for 12 to 36 months (average, 20 months). The healing time in these patients ranged from 8 to 25 weeks (average, 12 weeks). The postoperative score ranged from 47 to 100 points (average, 91.1 points). Seven cases were rated as excellent, two as good, and one as poor. The rate of excellent and good was 90%. Necrosis of skin and soft tissue and exposure of the plate happened in one patient, who eventually healed after 3 weeks by debridement with plate preserved and peroneal artery perforator flap transplantation. Loss of reduction happened to another patient, who was treated with revision surgery by open reduction and screw fixation again. To patients with obvious fracture displacement, whose soft tissues are irritated severely, emergency open reduction and internal fixation operation should be offered to prevent the necrosis of the flaps as far as possible. To patients with small fractures, it is advisable to choose open reduction and large diameter screw fixation, while plate and screw fixation may be better for the patients with large fragments, especially for those with the fracture line extending to the subtalar joint. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

Jiang J.,Tongji University | Usmani A.,University of Edinburgh
Computers and Structures | Year: 2013

The OpenSees framework has been extended to deal with frame structures under fire conditions. OpenSees is an object-oriented, open source software framework developed at UC Berkeley and has so far been focused on providing an advanced computational tool for analyzing the non-linear response of structural frames subjected to seismic excitations. New classes defining time-dependent temperature distributions in the cross-section of members have been created and OpenSees material classes have been modified to include temperature dependent properties based on the Eurocode. New functions and interfaces have been added into existing element and section classes to calculate the member actions due to arbitrary thermal loading taking into account material degradation with increasing temperature for non-linear analyses. This paper reports on a number of benchmark tests to ascertain the performance of the new codes implemented in OpenSees for beams, frames, and plate structures. The analysis procedures being developed for structures exposed to fire in OpenSees will make it easier for users to define temperature-dependent material properties and allow for arbitrary non-uniform temperature distributions across and along an element by interfacing a fire and heat transfer analysis module also being developed for OpenSees. This work will also enable the modeling of earthquake damaged structural frames subjected to a subsequent fire. © 2012 Published by Elsevier Ltd. All rights reserved.

Gao Y.-K.,Tongji University
Applied Surface Science | Year: 2013

The surface of TA15 titanium alloy was modified by pulsed electron beam and the hardness distribution along the treated surface layer was investigated by nanoindent technology. The grade characteristics were therefore analyzed by studying the distribution of hardness along surface layer of specimens. Moreover, the microstructure was investigated by OM, XRD and TEM techniques. Furthermore, the correlation of hardness to microstructure was analyzed. The results show that the grade fine grain microstructure is formed in the upper surface layer and the temperature grade or heat effect caused by pulsed electron beam treatment is the main reason to form grade fine grain microstructure in the surface layer. © 2012 Elsevier B.V. All rights reserved.

Yan B.,Tongji University
RSC Advances | Year: 2012

This critical review mainly focuses on recent research progress in photofunctional lanthanide hybrid materials. The review covers hybrids with complexes of organically modified silanes as precursors for sol-gel processing, hybrids with lanthanide complex units grafted onto the interior of mesoporous hosts, hybrids with lanthanide complex units on polymer chains, and other non-silica or composite-based lanthanide hybrids. The photophysical properties of lanthanide hybrids are also discussed. Finally, future challenges and opportunities in this field are discussed. © The Royal Society of Chemistry. 2012.

Yuan J.-J.,Tongji University
Telecommunication Systems | Year: 2014

Since wireless sensor networks (WSN) are often deployed in an unattended environment and sensor nodes are equipped with limited computing power modules, user authentication is a critical issue when a user wants to access data from sensor nodes. Recently, M.L. Das proposed a two-factor user authentication scheme in WSN and claimed that his scheme is secure against different kinds of attack. Later, Khan and Alghathbar (K-A) pointed out that Das' scheme has some security pitfalls and showed several improvements to overcome these weaknesses. However, we demonstrate that in the K-A-scheme, there is no provision of non-repudiation, it is susceptible to the attack due to a lost smart card, and mutual authentication between the user and the GW-node does not attained. Moreover, the GW-node cannot prove that the first message comes from the user. To overcome these security weaknesses of the K-A-scheme, we propose security patches and prove our scheme. © 2013 Springer Science+Business Media New York.

He L.,University of California at Riverside | Wang M.,University of California at Riverside | Ge J.,University of California at Riverside | Ge J.,Tongji University | Yin Y.,University of California at Riverside
Accounts of Chemical Research | Year: 2012

Responsive photonic structures can respond to external stimuli by transmitting optical signals. Because of their important technological applications such as color signage and displays, biological and chemical sensors, security devices, ink and paints, military camouflage, and various optoelectronic devices, researchers have focused on developing these functional materials. Conventionally, self-assembled colloidal crystals containing periodically arranged dielectric materials have served as the predominant starting frameworks. Stimulus-responsive materials are incorporated into the periodic structures either as the initial building blocks or as the surrounding matrix so that the photonic properties can be tuned. Although researchers have proposed various versions of responsive photonic structures, the low efficiency of fabrication through self-assembly, narrow tunability, slow responses to the external stimuli, incomplete reversibility, and the challenge of integrating them into existing photonic devices have limited their practical application.In this Account, we describe how magnetic fields can guide the assembly of superparamagnetic colloidal building blocks into periodically arranged particle arrays and how the photonic properties of the resulting structures can be reversibly tuned by manipulating the external magnetic fields. The application of the external magnetic field instantly induces a strong magnetic dipole-dipole interparticle attraction within the dispersion of superparamagnetic particles, which creates one-dimensional chains that each contains a string of particles. The balance between the magnetic attraction and the interparticle repulsions, such as the electrostatic force, defines the interparticle separation. By employing uniform superparamagnetic particles of appropriate sizes and surface charges, we can create one-dimensional periodicity, which leads to strong optical diffraction. Acting remotely over a large distance, magnetic forces drove the rapid formation of colloidal photonic arrays with a wide range of interparticle spacing. They also allowed instant tuning of the photonic properties because they manipulated the interparticle force balance, which changed the orientation of the colloidal assemblies or their periodicity.This magnetically responsive photonic system provides a new platform for chromatic applications: these colloidal particles assemble instantly into ordered arrays with widely, rapidly, and reversibly tunable structural colors, which can be easily and rapidly fixed in a curable polymer matrix. Based on these unique features, we demonstrated many applications of this system, such as structural color printing, the fabrication of anticounterfeiting devices, switchable signage, and field-responsive color displays. We also extended this idea to rapidly organize uniform nonmagnetic building blocks into photonic structures. Using a stable ferrofluid of highly charged magnetic nanoparticles, we created virtual magnetic moments inside the nonmagnetic particles. This "magnetic hole" strategy greatly broadens the scope of the magnetic assembly approach to the fabrication of tunable photonic structures from various dielectric materials. © 2012 American Chemical Society.

Huang Y.,Control Hosp. of Jinshan Dist. | Zhang C.,Tongji University | Luo Y.,Control Hosp. of Jinshan Dist.
International Orthopaedics | Year: 2013

Purpose: The purpose of this study was to compare the biomechanical strength of the cephalomedullary nail InterTAN in cases of intertrochanteric fractures with the commonly used PFNA. Methods: Sixteen fresh specimens of the proximal femur were used as intertrochanteric fracture models and were fixed using two fixation devices: the new proximal femoral nail (InterTAN) and proximal femoral nail antirotation (PFNA). An intertrochanteric fracture was created in composite bone models. Each specimen was loaded to simulate single leg stance while stiffness, migration (cut out), compressive force across the fracture site, and distal fragment rotation were monitored. The different internal fixation methods were tested by an experimental press analysis. Results: Results of tests for femoral strength, stiffness, stability, and bearing capacity demonstrated that the biomechanical function of InterTAN was better than that of PFNA (P < 0.05). Compared with the PFNA nail, InterTAN showed increased strength, stiffness, and resistance torque of 30 %, 15 %, and 27 %, respectively. Conclusion: Comparison of the treatment of intertrochanteric fractures with InterTAN and PFNA internal fixation showed that the InterTAN yielded improvement relative to the PFNA. InterTAN has a firmer and biomechanically superior performance and is therefore an ideal internal fixation method for treating intertrochanteric fractures. Additional research in osteopenic bone is necessary to comprehensively characterize the effects of the design enhancements of these two implants. © 2013 Springer-Verlag Berlin Heidelberg.

The purpose of this letter is to investigate the stochastic stability for a class of discrete-time Markovian jump delay neural networks with impulses and incomplete information on transition probability. By using Lyapunov functionals, some new results are provided. The obtained results show that impulses can stochastically stabilize an unstable discrete-time Markovian jump delay neural network. The obtained results also show that the stability property of the impulse-free neural network can be retained even under certain destabilizing impulses. Two examples together with their simulations are also presented to show the effectiveness and the advantage of the obtained results. © 2013 Elsevier Ltd.

Luo M.,Tongji University | Li Z.,Shanghai JiaoTong University | Wang W.,Shanghai JiaoTong University | Zeng Y.,Shanghai JiaoTong University | And 2 more authors.
Cancer Letters | Year: 2013

lncRNA H19 is essential for human tumor growth. However, little is known about whether H19 regulates bladder cancer metastasis. Here we found that H19 levels are remarkably increased in bladder cancer tissues, and upregulated H19 promotes bladder cancer cell migration in vitro and in vivo. H19 is associated with enhancer of zeste homolog 2 (EZH2), and that this association results in Wnt/β-catenin activation and subsequent downregulation of E-cadherin. A significant negative correlation is also observed between H19 levels and E-cad levels in vivo. These data suggest that upregulated H19 enhances bladder cancer metastasis by associating with EZH2 and inhibiting E-cad expression. © 2013 Elsevier Ireland Ltd.

Zhang R.J.,Tongji University
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2010

The Kirchhoff equations for flexible rods are extended to be able to describe size effects. Thus, the extended equations are applicable not only for macroscopic rods but also for ultrathin rods whose thickness is close to the material length. It is found that extensional size effects exist in flexible rods, namely, the external forces exerted on both ends of rods will increase as the rods are getting thinner if an identical deformation is remained. © 2010 The American Physical Society.

Wang J.,Tongji University
Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine | Year: 2012

A number of studies have investigated the role of matrix metalloproteinase 2 (MMP2) polymorphisms and expression in lung cancer, but have yielded inconsistent and inconclusive results. To derive a more precise estimate of the prognostic role of MMP2 expression and the susceptibility role of MMP2 polymorphisms in lung cancer, we reviewed published studies and carried out a meta-analysis. Eligible articles were identified in electronic databases. Case-control studies assessing the associations between MMP2 polymorphisms and lung cancer risk or cohort studies assessing the prognostic role of MMP2 expression in patients with lung cancer were included. Pooled odds ratio (OR) or hazard ratio (HR) with 95 % confidence interval (95 % CI) was used to assess the role of MMP2 polymorphisms and expression in lung cancer, respectively. Seven case-control studies (a total of 3,190 lung cancer cases and 3,013 controls) and 18 cohort studies (2,095 lung cancer patients) were eligible. Meta-analysis of seven case-control studies suggested that individuals with TT genotype of both MMP2 C735T and C1306T polymorphisms had obviously decreased risk of lung cancer compared with those with CC genotype (for MMP2 C735T, fixed effects OR = 0.69, 95 % CI 0.49-0.97, P = 0.032; for MMP2 C1306T, fixed effects OR = 0.54, 95 % CI 0.33-0.86, P = 0.010). Meta-analysis of 18 cohort studies suggested that patients with high MMP-2 expression had poorer overall survival (fixed effects HR = 1.82, 95 % CI 1.56-2.13, P < 0.001). Subgroup by study design, ethnicity and testing methods all further identified the prognostic value of MMP2 expression in lung cancer. In conclusion, MMP2 C735T and C1306T polymorphisms are both associated with lung cancer risk, and patients with high MMP2 expression levels have poorer overall survival compared with those with low MMP2 expression levels.

Shu S.,Tongji University | Lin F.,Wayne State University
IEEE Transactions on Automation Science and Engineering | Year: 2014

This paper considers fault-tolerant control that ensures the safety of a discrete-event system. We consider multiple faulty modes. Each faulty mode is modeled by an automaton. These automata, together with the automaton modeling normal mode, describe a discrete-event system with faults. Each faulty mode has some illegal states that must be avoided by control so that the fault can be tolerated. We assume that fault-tolerant control takes actions (disablements) only when the occurrence of a fault is certain. We consider cases of both full event observation and partial event observation. We derive necessary and sufficient conditions for the existence of fault-tolerant control. We also provide formulas and algorithms to calculate control actions if the necessary and sufficient conditions are satisfied. Both offline control synthesis (for full event observation) and online control synthesis (for partial event observation) are investigated. We allow multiple faults as well as single faults. © 2013 IEEE.

Ye S.,Duke University | Rathmell A.R.,Duke University | Chen Z.,Duke University | Chen Z.,Tongji University | And 2 more authors.
Advanced Materials | Year: 2014

There is an ongoing drive to replace the most common transparent conductor, indium tin oxide (ITO), with a material that gives comparable performance, but can be coated from solution at speeds orders of magnitude faster than the sputtering processes used to deposit ITO. Metal nanowires are currently the only alternative to ITO that meets these requirements. This Progress Report summarizes recent advances toward understanding the relationship between the structure of metal nanowires, the electrical and optical properties of metal nanowires, and the properties of a network of metal nanowires. Using the structure-property relationship of metal nanowire networks as a roadmap, this Progress Report describes different synthetic strategies to produce metal nanowires with the desired properties. Practical aspects of processing metal nanowires into high-performance transparent conducting films are discussed, as well as the use of nanowire films in a variety of applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wang S.,Tongji University
International Journal of Industrial and Systems Engineering | Year: 2014

Much of the research on operations scheduling problems has ignored setup times and also assumes that output warehouse (or buffer) is infinite. While in many real-world production scheduling systems, it requires explicit consideration of sequence-dependent setup times and limited capacity output warehouse. This paper studies a single machine scheduling (SMS) problem considering sequence-dependent setup times and limited capacity output warehouse simultaneously, with the objective of minimising the total tardiness. A mathematical model is constructed to depict the problem. As the problem is NP-hard, a modified ant colony optimisation (ACO) method based on ant system meta-heuristic is presented to solve the problem. Incorporated with different state transition rules due to different combinations of heuristic information, several versions of the ACO method are generated. For each method, parameters are tuned with design of experiments (DOE). Then, based on different settings of experimental simulation, the performance of the methods is discussed and also compared with those of genetic algorithm (GA) and dispatching rules. The results show the feasibility and effectiveness of the proposed method for the considered problem. © 2014 Inderscience Enterprises Ltd.

Zhou J.,Tongji University | Gallion P.,Telecom ParisTech
IEEE Photonics Technology Letters | Year: 2013

In this letter, a mode multiplexer/demultiplexer (MUX/DEMUX) for multi-core fibers (MCFs) based on multimode interference (MMI) effect is proposed. Due to the coincidence of the rows of the transfer matrix of an MMI coupler and the modal profile of the MCFs with linearly aligned cores, an MMI coupler with the aid of a phase shifter array is able to distinguish different super-modes of the MCFs. The output port number indicates the number of the super-modes inside the MCFs. Detailed theoretical derivations and numerical simulations are provided to demonstrate the multiplexing/demultiplexing capability of the device. The proposed mode MUX/DEMUX can be fiber based or waveguide based and is easy to be integrated with the fiber system. © 1989-2012 IEEE.

Zhou J.,Tongji University
Optics Express | Year: 2014

In this paper, an analytical approach is proposed to minimize the mode dependent gain as well as the wavelength dependent gain for the multimode fiber Raman amplifiers (MFRAs). It is shown that the optimal power integrals at the corresponding modes and wavelengths can be obtained by the non-negative least square method (NNLSM). The corresponding input pump powers can be calculated afterwards using the shooting method. It is demonstrated that if the power overlap integrals are not wavelength dependent, the optimization can be further simplified by decomposing the optimization problem into two sub optimization problems, i.e. the optimization of the gain ripple with respect to the modes, and with respect to the wavelengths. The optimization results closely match the ones in recent publications. ©2014 Optical Society of America.

Low B.K.,Nanyang Technological University | Zhang J.,Tongji University | Tang W.H.,Hong Kong University of Science and Technology
Computers and Geotechnics | Year: 2011

Although first-order reliability method is a common procedure for estimating failure probability, the formulas derived for bimodal bounds of system failure probability have not been widely used as expected in present reliability analyses. The reluctance for applying these formulas in practice may be partly due to the impression that the procedures to implement the system reliability theory are tedious. Among the methods for system reliability analysis, the approach suggested in Ditlevsen 1979 is considered here because it is a natural extension of the first-order reliability method commonly used for failure probability estimation corresponding to a single failure mode, and it can often provide reasonably narrow failure probability bounds. To facilitate wider practical application, this paper provides a short program code in the ubiquitous Excel spreadsheet platform for efficiently calculating the bounds for system failure probability. The procedure is illustrated for a semi-gravity retaining wall with two failure modes, a soil slope with two and eight failure modes, and a loaded beam with three failure modes. In addition, simple equations are provided to relate the correlated but unrotated equivalent standard normals of the Low and Tang 2007 FORM procedure with the uncorrelated but rotated equivalent standard normals of the classical FORM procedure. Also demonstrated are the need for investigating different permutations of failure modes in order to get the narrowest bounds for system failure probability, and the use of SORM reliability index for system reliability bounds in a case where the curvature of the limit state surface cannot be neglected. © 2010 Elsevier Ltd.

Meyer C.A.,Dana-Farber Cancer Institute | Tang Q.,Tongji University | Liu X.S.,Dana-Farber Cancer Institute
Molecular Endocrinology | Year: 2012

Next-generation sequencing technologies have expanded the experimental possibilities for studying the genome-wide regulation of transcription by nuclear receptors, their collaborating transcription factors, and coregulators. These technologies allow investigators to obtain abundance and DNA sequence information in a single experiment. In this review, we highlight proven and potential uses of next-generation sequencing in the study of gene regulation by nuclear receptors. We also provide suggestions on how to effectively leverage this technology in a collaborative environment. © 2012 by The Endocrine Society.

Sheikholeslami M.,Babol Noshirvani University of Technology | Rashidi M.M.,Tongji University | Rashidi M.M.,ENN Group
Journal of the Taiwan Institute of Chemical Engineers | Year: 2015

Effect of spatially variable magnetic field on ferrofluid flow and heat transfer is investigated. The enclosure is filled with Fe3O4-water nanofluid. Control volume based finite element method (CVFEM) is applied to solve the governing equations. The combined effects of ferrohydrodynamic and magnetohydrodynamic have been taken into account. The influences of Magnetic number, Hartmann number, Rayleigh number and nanoparticle volume fraction on the flow and heat transfer characteristics have been examined. Results show that enhancement in heat transfer decrease with increase of Rayleigh number while for two other active parameters different behavior is observed. Also it can be concluded that Nusselt number is an increasing function of Magnetic number, Rayleigh number and nanoparticle volume fraction while it is a decreasing function of Hartmann number. © 2015 Taiwan Institute of Chemical Engineers.

Chen J.,National University of Singapore | Zhang G.,Peking University | Li B.,National University of Singapore | Li B.,Tongji University
Nanoscale | Year: 2013

Thermal conductivity κ of both suspended and supported graphene has been studied by using molecular dynamics simulations. An obvious length dependence is observed in κ of suspended single-layer graphene (SLG), while κ of supported SLG is insensitive to the length. The simulation result of room temperature κ of supported SLG is in good agreement with the experimental value. In contrast to the decrease in κ induced by inter-layer interaction in suspended few-layer graphene (FLG), κ of supported FLG is found to increase rapidly with the layer thickness, reaching about 90% of that of bulk graphite at six layers, and eventually saturates at the thickness of 13.4 nm. More interestingly, unlike the remarkable substrate dependent κ in SLG, the effect of substrate on thermal transport is much weaker in FLG. The underlying physics is investigated and presented. This journal is © The Royal Society of Chemistry.

Partial liquid ventilation (PLV) with perfluorocarbons (PFC) seems not superior to conventional ventilation clinically. We hypothesized that a combination of continuous tracheal gas insufflation (TGI) with protective strategy of PLV (low dose of PFC, low inflation pressure, moderate inhalation of oxygen and moderate anesthesia) would improve cardiopulmonary function in acute lung injury. Twenty-four healthy juvenile piglets were anesthetized and mechanically ventilated at PEEP of 2 cmH(2)O with a peak inspiratory pressure of 10 cmH(2)O and FIO(2) of 0.4. The piglets were challenged with lipopolysaccharide and randomly assigned to four groups (n = 6 each): (1) mechanical ventilation alone (MV); (2) PLV with perfluorodecalin (10 ml/kg); (3) TGI with continuous airway flow 2 L/min; and (4) combination of PLV and TGI. The outcome was assessed functionally and histologically. All treatments except MV improved pH, PaO(2)/FIO(2), PaCO(2), ventilation efficacy index (VEI) and tidal volume. Both PLV-associated treatments also improved heart rate, respiratory rate, pulse contour cardiac output, systemic vascular resistance, dynamic lung compliance, mean airway resistance and mean airway pressure. The combination group resulted in higher PaO(2)/FIO(2), VEI and a better lung histology score than any other treatments. The new protective strategy may provide a better treatment for sepsis-induced acute lung injury.

Tan Y.,Tongji University | Wei B.,China Railway Eryuan Engineering Group Co.
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2011

A 16-18 m deep excavation for a metro station with in-plane dimensions of approximately 20 m wide by 290 m long was constructed by using the cut-and-cover technique in soft clay in the Shanghai metropolitan area, in which many high-rise buildings and utilities exist. To investigate the performance of this deep excavation and the associated effect on the adjacent buildings and utility pipelines, a long-term comprehensive instrumentation program was conducted during construction. Field observations included deflections of diaphragm walls, vertical movements at wall tops, ground settlements, and settlements of surrounding buildings and utilities. Analyses of field data indicated that overexcavation (i.e., removing more soil than designed) and a long construction duration caused the diaphragm walls to develop substantial deflections. The base and middle floor slabs played dominant roles in suppressing postexcavation wall deflections and ground settlements. This excavation in general exhibited different behaviors than other excavation projects because of its relatively long shape. Behaviors of deep excavations in Shanghai soft clay are affected not only by construction duration (i.e., time effects), but also by their geometries (i.e., space effects). This project serves as a special case study and provides insights into the design and construction of a long and deep excavation that uses the cut-and-cover technique in soft soils and in a metropolitan environment. © 2012 American Society of Civil Engineers.

Tang D.G.,University of Texas M. D. Anderson Cancer Center | Tang D.G.,Tongji University
Cell Research | Year: 2012

Heterogeneity is an omnipresent feature of mammalian cells in vitro and in vivo. It has been recently realized that even mouse and human embryonic stem cells under the best culture conditions are heterogeneous containing pluripotent as well as partially committed cells. Somatic stem cells in adult organs are also heterogeneous, containing many subpopulations of self-renewing cells with distinct regenerative capacity. The differentiated progeny of adult stem cells also retain significant developmental plasticity that can be induced by a wide variety of experimental approaches. Like normal stem cells, recent data suggest that cancer stem cells (CSCs) similarly display significant phenotypic and functional heterogeneity, and that the CSC progeny can manifest diverse plasticity. Here, I discuss CSC heterogeneity and plasticity in the context of tumor development and progression, and by comparing with normal stem cell development. Appreciation of cancer cell plasticity entails a revision to the earlier concept that only the tumorigenic subset in the tumor needs to be targeted. By understanding the interrelationship between CSCs and their differentiated progeny, we can hope to develop better therapeutic regimens that can prevent the emergence of tumor cell variants that are able to found a new tumor and distant metastases. © 2012 IBCB, SIBS, CAS All rights reserved.

Cheng C.,Tongji University | Sun Y.,CAS Shanghai Institute of Technical Physics
Applied Surface Science | Year: 2012

In the present study, we demonstrate a facile route to fabricate vertical-aligned carbon doped TiO2 nanowire arrays on FTO substrate by combining of a simple hydrothermal growth and a subsequent calcination process in air. The photoelectrochemical measurements indicate that the carbon doped TiO2 photoanode yields a ∼70% enhancement in the photocurrent density in comparison to that of the pristine TiO2. Further IPCE, diffuse reflectance spectra and electrochemical impedance characterizations confirm that the photocurrent improvement is mainly in the UV light region, which is arise from the increased charge carrier densities as well as improved charge transfer and separation induced by carbon doping. © 2012 Elsevier B.V.

Zhang J.,Tongji University | Shen L.,University of Shanghai for Science and Technology
Computational Intelligence and Neuroscience | Year: 2014

To organize the wide variety of data sets automatically and acquire accurate classification, this paper presents a modified fuzzy c-means algorithm (SP-FCM) based on particle swarm optimization (PSO) and shadowed sets to perform feature clustering. SP-FCM introduces the global search property of PSO to deal with the problem of premature convergence of conventional fuzzy clustering, utilizes vagueness balance property of shadowed sets to handle overlapping among clusters, and models uncertainty in class boundaries. This new method uses Xie-Beni index as cluster validity and automatically finds the optimal cluster number within a specific range with cluster partitions that provide compact and well-separated clusters. Experiments show that the proposed approach significantly improves the clustering effect. © 2014 Jian Zhang and Ling Shen.

Cui W.-W.,Shanghai JiaoTong University | Lu Z.,Tongji University | Pan E.,Shanghai JiaoTong University
Computers and Operations Research | Year: 2014

This paper addresses the problem of finding robust production and maintenance schedules for a single machine with failure uncertainty. Both production and maintenance activities occupy the machine×.

Kleemann W.,University of Duisburg - Essen | Miga S.,University of Silesia | Dec J.,University of Silesia | Zhai J.,Tongji University
Applied Physics Letters | Year: 2013

The electric susceptibilities χ1, χ2, and χ3 of BaTi1-xZrxO3 ceramics with 0.25 ≤ x ≤ 0.35 are measured at 90 ≤ T ≤ 350 K and 37 ≤ f ≤ 106 Hz. Crossover from ferroelectric (x = 0.25) to relaxor behavior (x = 0.35) via coexistence of both (x = 0.30) is indicated by increasing polydispersivity and suppression of χ2 intensity and negative χ3 tails. The relaxor properties are due to weak random fields acting on dipolar Ti4+ clusters in non-polar Zr4+ environment. Frustrated interaction between blocked polar nanoregions yields a cluster glass ground state for x = 0.35. © 2013 AIP Publishing LLC.

Mo F.,CAS Beijing National Laboratory for Molecular | Jiang Y.,Tongji University | Qiu D.,CAS Beijing National Laboratory for Molecular | Zhang Y.,CAS Beijing National Laboratory for Molecular | Wang J.,CAS Beijing National Laboratory for Molecular
Angewandte Chemie - International Edition | Year: 2010

Leave the metal out: Arylboronates are produced In moderate to good yields by direct borylation of readily available aryl amines (see scheme). The reaction can be carried out under air at room temperature and transition-metal catalysis is not required. The boronate products can be used without purification in SuzukiMiyaura cross-coupling reactions. Chemical equation representation © 2010 Wiley-VCH Verlag GmbH & Co. KGaA www.angewandte.org.

Hu W.,Tongji University
Nanotechnology | Year: 2010

The objectives of this work are twofold. Firstly, while most work on electrospinning is limited to the development of only functional materials, a structural application of electrospun nanofibers is explored. Secondly, a drug-loaded tissue suture is fabricated and its various properties are characterized. Braided drug-loaded nanofiber sutures are obtained by combining an electrospinning process with a braiding technique followed by a coating procedure. Two different electrospinning techniques, i.e. blend and coaxial electrospinning, to incorporate a model drug cefotaxime sodium (CFX-Na) into poly(L-lactic acid) (PLLA) nanofibers have been applied and compared with each other. Properties of the braided drug-loaded sutures are characterized through a variety of methods including SEM, TEM and tensile testing. The results show that the nanofibers had a preferable micromorphology. The drug was incorporated into the polymer nanofibers homogeneously, with no cross-linking. The nanofibers maintained their fibrous structures. An in vitro release study indicates that the drug-loaded nanofibers fabricated by blend electrospinning and coaxial electrospinning had a different drug release behavior. An inhibition zone experiment shows that both sutures obtained from the nanofibers of the different electrospinning techniques had favorable antibacterial properties. The drug-loaded sutures had preferable histological compatibility performance compared with commercial silk sutures in an in vivo comparative study.

Jones B.,University of Alberta | Peng X.,Tongji University
Sedimentary Geology | Year: 2012

Calcium carbonate nanoparticles are intimately associated with crystalline calcite and aragonite in the Eryuan, Gongxiaoshe, and Zhuyuan hot springs (water temperature >75°C), which are located in Yunnan Province, China. The nanoparticles, <1μm long, are spherical to disc-shaped and commonly fuse together into small clusters. Their general appearance and lack of crystal faces or edges indicate that they are noncrystalline. Morphologically, these nanoparticles are similar to calcified nannobacteria or the constituent grains in amorphous calcium carbonate (ACC), which can be formed by various biogenic and abiogenic processes. In the Chinese hot springs, the ACC is always found under, in, or on top of biofilms, commonly in close proximity to crystalline calcite and/or aragonite. Textural evidence indicates that the ACC probably developed in microdomains that develop in the complex biofilm hydrogels. Critically, there is no evidence to support the notion that the nanoparticles are calcified nannobacteria. In the Chinese springs, ACC appears to play a formative role in the development of wheat-sheaf arrays of aragonite crystals and some of the calcite crystals. Hollow cores in some of the aragonite bundles probably formed as ACC was dissolved and many of the aragonite crystals appear to have developed as ACC recrystallized. Similarly, layers of ACC that coat the surfaces of some calcite crystals could be diagenetically transformed into calcite. The development of ACC in hot spring systems may be widespread and may play a critical but transitory role in the development of crystalline CaCO 3 in these high temperature environments. © 2012 Elsevier B.V.

Xu Q.,Tongji University
Numerical Heat Transfer, Part B: Fundamentals | Year: 2013

This article presents the idea for calculating 2-D steady-state heat conduction problems with multidomain combination by employing the virtual boundary meshless least-square method. Being different from the conventional virtual boundary-element method (VBEM), this method incorporates the point interpolation method (PIM) with the compactly supported radial basis function (CSRBF) to approximately construct the virtual source function of the VBEM. Thus, the proposed method has the advantages of both the boundary-type meshless method and the virtual boundary element method. Since the configuration of the virtual boundary requires a certain preparation, the integration along the virtual boundary can be carried out over the smooth simple curve that can be structured beforehand (for 2-D problems) to reduce the complexity and difficulty of calculus without loss of accuracy, while the "vertex question" existing in the BEM can be avoided. Numerical examples show that the proposed method is more precise than several other numerical methods while selecting fewer degrees of freedom. In addition, its numerical stability is also verified by computing several cases. © 2013 Copyright Taylor and Francis Group, LLC.

Wang J.,City University of Hong Kong | Jiang M.,Tongji University
Granular Matter | Year: 2011

Based on a detailed analysis of DEM simulation data, this paper provides new insights into the effects of boundary surface topography on the mobilized stress ratio and stress-displacement behavior in the interface shear test and the direct shear test. The soil mechanics observed in the two types of tests are unified under a novel perspective of boundary-induced soil behavior. It is shown that the principal direction of the contact force anisotropy developed at the soil-surface boundary has an exclusive control over the peak stress ratio measured both at the boundary and inside the sampling window. However, a subtle change in the roles of the principal direction and the magnitude of contact force anisotropy is found as the contact force chains extend from the surface into the interphase soil. © 2011 Springer-Verlag.

Lei J.,Tongji University
Annals of Thoracic Surgery | Year: 2010

Mucoepidermoid carcinoma is a rare tumor of the lung that accounts for 0.1% to 0.2% of all pulmonary tumors. Herein we report our experience with a patient who suffered from bronchial mucoepidermoid carcinoma and 2-year left lung atelectasis. The tumor originated from the orifice of the left upper bronchus and obstructed the left main stem bronchus. A left upper sleeve lobectomy was performed and the remaining atelectatic lower lobe was fully expanded by 6 months postoperatively. The patient's pulmonary function significantly improved. © 2010 The Society of Thoracic Surgeons.

The feasibility of electrolysis integrated with Fe(II)-activated persulfate (S2O8(2-)) oxidation to improve waste activated sludge (WAS) dewaterability was evaluated. The physicochemical properties (sludge volume (SV), total suspended solids (TSS) and volatile suspended solids (VSS)) and extracellular polymeric substances (EPS), including slime EPS, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were characterized to identify their exact roles in sludge dewatering. While dewaterability negatively corresponded to LB-EPS, TB-EPS, protein (PN) and polysaccharide (PS) in LB-EPS and TB-EPS, it was independent of SV, TSS, VSS, slime EPS and PN/PS. Further study through scanning electron microscope (SEM) verified the entrapment of bacterial cells by TB-EPS, protecting them against electrolysis disruption. Comparatively, electrolysis integrated with S2O8(2-)/Fe(II) oxidation was able to effectively disrupt the protective barrier and crack the entrapped cells, releasing the water inside EPS and cells. Therefore, the destruction of both TB-EPS and cells is the fundamental reason for the enhanced dewaterability. Copyright © 2013 Elsevier Ltd. All rights reserved.

Zhang J.,Tongji University
International journal of medical sciences | Year: 2012

To investigate the effects of bone morphogenetic protein-2 (BMP-2) on the proliferation, differentiation and apoptosis of normal human gastric mucosal cells and gastric cancer cells. Poorly differentiated gastric cancer BGC823 cells, moderately differentiated gastric cancer cells and normal human gastric mucosal epithelial GES-1 cells were independently treated with recombinant human BMP-2 or its inhibitor Noggin. MTT assay was performed to detect the proliferation, flow cytometry done to measure the cell cycle and apoptosis and immunohistochemistry carried out to determine the expression of cyclin-dependent kinase 4 (CDK4). BMP-2 exerted inhibitory effect on the growth of all types of cells and the inhibition become more evident with the increase of BMP-2 dose. After treatment with 200 ng/ml BMP-2, cancer cells arrested in G1 phase and those in S phase reduced. Gastric cancer cells had higher CDK4 expression than GES-1 cells. BMP-2 decreased CDK-4 expression in cancer cells but had no influence in GES-1 cells. Noggin conferred promotive effect on the growth of 3 types of cells. In 2 types of cancer cells, treatment with 2000 ng/ml Noggin significantly increased the proportion of cells in S phase but reduced that in G1 phase. However, Noggin did not affect the cell cycle of GES-1 cells. The CDK4 expression was markedly increased in 2 types of cancer cells but that of GES-1 remained unchanged after treatment with 2000 ng/ml Noggin. BMP-2 may inhibit the proliferation of both normal and malignant gastric epithelial cells, down-regulate CDK4 expression in gastric cancer cells and arrest gastric cancer cells in G1-phase in cell cycle. Through antagonizing BMP-2, Noggin, may accelerate the proliferation of gastric cancer cells. Thus, the abnormality of BMP signaling pathway may play an important role in the pathogenesis of gastric cancer.

In recent years, bezafibrate (BZF) has been frequently detected in environmental media. In order to reveal the toxicity of such an emerging pollutant, its interaction with human serum albumin (HSA) was studied by fluorescence spectrometry, circular dichroism, and equilibrium dialysis. Fluorescence data showed that the fluorescence quenching of HSA by BZF resulted from the formation of HSA-BZF complex. The binding constants were determined to be 3.33 × 10 3, 2.84 × 10 3 M -1 at 298 and 309.5 K, respectively. The thermodynamic determination indicated that the hydrophobic and electrostatic interaction were the dominant binding force. The conformational investigation showed that the presence of BZF increased the α-helix content of HSA and induced the slight unfolding of the polypeptides of protein. Finally, the equilibrium dialysis showed that 0.56 mM BZF decreased the binding of vitamin B 2 to HSA by 29%.

Geng H.,Tongji University | Clopotel C.S.,University of Wisconsin - Madison | Bahia H.U.,University of Wisconsin - Madison
Construction and Building Materials | Year: 2013

Several factors related to the performance of high modulus asphalt binders (HMABs) in pavement engineering were studied: stiffness, elastic recovery, asphalt layer thickness reduction, workability and thermal cracking resistance. Results showed that HMABs had higher stiffness and elasticity than neat binder. The asphalt layers thickness could be significantly reduced by replacing neat binder with HMABs. The coarse aggregate absorption method provided reasonable means to estimate mixing temperature for HMABs. The application of HMABs where the low design temperature of the pavement is lower than -16 C should be with caution based on the low temperature performance grades of HMABs. Crown Copyright © 2013 Published by Elsevier Ltd. All rights reserved.

Zhou J.,Tongji University | Gallion P.,Telecom ParisTech
IEEE Photonics Technology Letters | Year: 2014

In this letter, a mode multiplexer/demultiplexer (MUX/DEMUX) for multicore fibers with 2D aligned cores is proposed. The device is based on the concept of 2D multimode interference (2DMMI) effect. If the 2D waveguide array is aligned within a square lattice, the supermodes of the array will obey the sinusoidal function and coincide with the transfer matrix of the 2DMMI couplers with phase shifter arrays. Therefore, a mode MUX/DEMUX with high mode extinction ratio can be realized based on this principle. © 2014 IEEE.

Yu Z.,Tongji University | Yu Z.,Thomas Jefferson University | Pestell R.G.,Thomas Jefferson University
Journal of Mammary Gland Biology and Neoplasia | Year: 2012

Small non-coding RNAs include siRNA, miRNA, piRNA and snoRNA. The involvement of miRNAs in the regulation of mammary gland tumorigenesis has been widely studied while the role for other small non-coding RNAs remains unclear. Here we summarize the involvement of miRNA in breast cancer onset and progression through regulating the cell cycle and cellular proliferation. The regulation of breast cancer stem cells and tumor regeneration by miRNA is reviewed. In addition, the emerging evidence demonstrating the involvement of piRNA and snoRNA in breast cancer is briefly described. © 2012 The Author(s).

Han T.,National University of Singapore | Bai X.,National University of Singapore | Thong J.T.L.,National University of Singapore | Li B.,National University of Singapore | And 2 more authors.
Advanced Materials | Year: 2014

Thermal camouflage and cloaking can transform an actual heat signature into a pre-controlled one. A viable recipe for controlling and manipulating heat signatures using thermal metamaterials to empower cloaking and camouflage in heat conduction is demonstrated. The thermal signature of the object is thus metamorphosed and perceived as multiple targets with different geometries and compositions, with the original object cloaked. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heinz N.A.,California Institute of Technology | Ikeda T.,Ibaraki University | Pei Y.,Tongji University | Snyder G.J.,California Institute of Technology
Advanced Functional Materials | Year: 2014

Microstructure control in functional materials draws from a historical reserve rich in established theory and experimental observation of metallurgy. Methods such as rapid solidification, eutectoid reaction, and nucleation and growth precipitation have all proven to be effective means to produce microstructure relevant for a wide array of applications. Here, the available parameters to control structure morphology, size, and spacing are discussed using thermoelectric composites as an example. Moreover, exploiting different aspects of a material system's phase diagram enables a controlled introduction of nanostructures. While much of this discussion is pertinent to the rapidly developing field of thermal conductivity control in thermoelectric composites, these techniques can be applied to a variety of other material systems where their use may lead to novel electrical, optical, as well as thermal properties of semiconductors and insulators as it has in the past for the mechanical properties of metals. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In this paper, we propose a novel 1 to N optical power splitter and a 1 to N optical switch for a multi-core fiber (MCF) with N circularly aligned cores. The splitter and the switch are based on the multimode interference (MMI) effect inside a ring core fiber. The MMI effect will convert one image into N output images in the ring and therefore, the ring shape MMI coupler can act as a 1 to N power splitter. These images will have different phases. If two ring shape MMI couplers are used and a tunable phase shifter array and a fixed phase shifter array are placed between them, by properly setting the phases of the N images in the middle of the MMI couplers, the images will converge to one output port of the 2nd MMI coupler. The output port number can be changed by tuning the phase shifters. In this way, the input signal at one of the cores of the MCF can be switched to the other core, and a 1 to N switch can be realized. In the analysis, it is found that only one control parameter is required for the phase adjustment of the tunable phase shifter array in order to achieve the switching between the cores. © 2015 Optical Society of America.

Li W.Z.,Tongji University
Genetics and molecular research : GMR | Year: 2012

The GAL4/UAS binary system has been widely used in Drosophila melanogaster for ectopic expression of transgenes in a tissue-specific manner. The GMR-GAL4 driver, which expresses the yeast transcription factor GAL4 under the control of glass multiple reporter (GMR) promoter elements, has been commonly utilized to express target transgenes, specifically in the developing eye. However, we have observed abnormal wing phenotypes; this is a result of the activity of critical wing developing genes, e.g., components of the Notch or Wg pathway, that are up- or down-regulated under the control of the GMR-GAL4 driver. X-gal staining confirmed that UAS-LacZ is expressed in third-instar larva wing imaginal discs, as well as in eye discs, when driven by the GMR-GAL4 driver. Furthermore, we found that GMR-GAL4 also drives UAS-LacZ expression in other tissues, such as brain, trachea, and leg discs. These results indicate that GMR-GAL4 has a broad expression profile, rather than the eye-specific pattern described previously, and that one should be careful when using it as a tool for targeted gene expression.

Wang S.,Tongji University
International Journal of Impact Engineering | Year: 2016

This manuscript presents studies from brittle to ductile fracture by a simplified meshfree method. The Johnson-Cook model is employed to model the behaviour in the bulk, while the cracking particles methods (CPM) are used to model discrete cracks. The influence of a cohesive zone model on the crack paths and the crack speed is studied. It will be shown that it has only a minor influence on the results for ductile fracture while it affects the crack speed for brittle fracture. Furthermore, the influence of temperature is tested, and it is shown that for ductile fracture, the temperature is the key parameter while it has less effect for brittle fracture. Double-notched and single-notched specimens are tested, and the experimental results are compared to results of our computational method for different discretisations. These results reveal that our method is a good pathway to study the failure transition from brittle-to-ductile fracture. © 2015 Elsevier Ltd. All rights reserved.

Feng Y.,Tongji University | Feng Y.,Beijing Jiaotong University | Chen X.,Beijing Jiaotong University | Xu X.F.,Beijing Jiaotong University | Xu X.F.,Stevens Institute of Technology
Renewable and Sustainable Energy Reviews | Year: 2014

This research focuses on the enhanced geothermal systems (EGS) potential in China and related technology, especially induced microseismicity and carbon storage combination. Hydraulic fracturing mechanisms applied in EGS were compared with similar fracturing mechanisms for shale gas. Besides, geothermal gradient in China was mapped based on the most recent heat flow values with interpolation method. The development history of geothermal plants in China was comprehensively reviewed through case studies. This paper revealed that the geothermal measuring wells in China were too shallow and too few to offer an accurate estimation. A coming work should aim at heat flow survey in deep layer, induced microseismicity mechanisms, and economically feasible scope in China. These problems will strengthen practical understanding and facilitate extensive application of EGS in China. © 2014 Elsevier Ltd.

Song Y.,Tongji University | Zou X.,University of Western Ontario
Computers and Mathematics with Applications | Year: 2014

Spatiotemporal dynamics in a ratio-dependent predator-prey model with diffusion is studied by analytical methods. Normal forms associated with codimension-two Hopf-Turing bifurcation are derived, which can be used to understand and classify the spatiotemporal dynamics of the model for values of parameters close to the Hopf-Turing bifurcation point. In the vicinity of this degenerate point, a wealth of complex spatiotemporal dynamics are observed. Our theoretical results are confirmed by numerical simulations. © 2014 Elsevier Ltd. All rights reserved.

Yao Z.L.,Tongji University
Genetics and molecular research : GMR | Year: 2012

Oryzias latipes (Adrianichthyidae), known as Japanese medaka or Japanese killifish, is a small 2-4 cm long fish common in rice paddies in coastal Southeast Asia and is also a popular aquarium fish. It has been widely used as a research model because of its small size and because it is very easy to rear. Alkalinity stress is considered to be one of the major stressors on fish in saline-alkaline water. As very little is known about molecular genetic responses of aquatic organisms to alkalinity stress, we examined genome-wide gene expression profiles of Japanese medaka in response to carbonate alkalinity stress. Adult fish were exposed to freshwater and high carbonate alkaline water in the laboratory. We designed a microarray containing 26,429 genes for measuring gene expression change in the gills of the fish exposed to high carbonate alkalinity stress. Among these genes, 512 were up-regulated and 501 were down-regulated in the gills. These differentially expressed genes can be divided into gene groups using gene ontology, including biological processes, cellular components and molecular function. These gene groups are related to acid-base and ion regulation, cellular stress response, metabolism, immune response, and reproduction processes. Biological pathways including amino sugar and nucleotide sugar metabolism, porphyrin and chlorophyll metabolism, metabolism of xenobiotics by cytochrome P450, drug metabolism, aminoacyl-tRNA biosynthesis, glycine, serine and threonine metabolism, ascorbate and aldarate metabolism, pentose and glucuronate interconversions, glutathione metabolism, and fructose and mannose metabolism were significantly up-regulated. Alkalinity stress stimulates the energy and ion regulation pathways, and it also slows down the pathways related to the immune system and reproduction.

Mei X.,National University of Singapore | Zheng H.,National University of Singapore | Zheng H.,Tongji University | Ouyang J.,National University of Singapore
Journal of Materials Chemistry | Year: 2012

Graphene has been attracting strong attention due to its interesting structure and properties and important applications in many areas. The process of the oxidation of graphite into graphene oxide (GO) and the subsequent reduction of GO into graphene is regarded as an effective process to produce graphene on a large scale. The quality of the reduced GO is strongly dependent on the reduction method. This paper reports the reduction of GO with Zn powder in neutral and alkaline aqueous solutions at room temperature. The reducing capability of Zn powder can be significantly improved through the complex formation of Zn 2+ with other species in solution, which greatly lowers the Zn 2+ concentration. Ethylenediaminetetraacetic acid (EDTA) can form an Zn-EDTA 2- complex with Zn 2+ and it is used for the reduction of GO by Zn in a neutral solution. The complex formation gives rise to quite low Zn 2+ concentrations in solution. This effectively lowers the reduction potential of Zn/Zn 2+ and enables the reduction of GO in neutral solutions. GO can be effectively reduced by Zn powder in alkaline solutions without EDTA as well. This is attributed to the complex formation of Zn 2+ with OH -, where Zn 2+ + 4OH -→ Zn(OH) 4 2-. The reduced GO produced by these methods has high quality. Their C/O ratios for products obtained through GO reductions in neutral and alkaline solutions are 33.0 and 31.2 and their conductivities are 142 and 135 S cm -1, respectively. © 2012 The Royal Society of Chemistry.

Li B.,Tongji University
Journal of Surveying Engineering | Year: 2016

The ballastless track can overcome the disadvantages of a traditional ballast track, such as lower longitudinal and lateral permanent stability and expensive maintenance, and is thus suitable for a high-speed railway (HSR) that is 350 km/h or even faster. The continuous track slabs in the ballastless track have very precise geometric parameters andmust be precisely installed to guarantee the ride comfort of a high-speed train. Therefore, the so-called CPIII control network was built, for which both careful field surveying and rigorous data adjustment were performed. In this paper, howthe CPIII network is built in a hierarchical procedure will be systematically introduced. More importantly, a new dataprocessing strategy is proposed, including free and constrained network adjustment realized by using different S-datummatrices. In free network adjustment, data snooping and variance component estimation (VCE) are interactively implemented for excluding outliers and retrieving realistic observation precisions. In constrained network adjustment, quasi-stable adjustment along with hypothesis testing is implemented to select the stable control points, followed by tightly constrained adjustment to obtain the coordinates of CPIII points. With the first ballastless track HSR in China as an example, the performance of proposed data-processing strategies is demonstrated, showing the importance and efficiency of data snooping,VCE, and selection of stable points. Following the strategy of network design, field data collection, and data processing, the ultraprecision results with reasonable quality control can be achieved to meet HSR demand. © 2016 American Society of Civil Engineers.

Zhou J.,Tongji University
Optics Express | Year: 2014

In this paper, a non-orthogonal coupled mode theory is proposed to analyze the super-modes of multi-core fibers (MCFs). The theory is valid in the strong coupling regime and can provide accurate analytical formulas for the super-modes inside MCFs. MCFs with circularly distributed cores are analyzed as an example. Analytical formulas are derived both for the refractive indexes and the eigen vectors of the super-modes. It is rigorously revealed that the eigen vectors for the super-modes of such MCFs are the row vectors of the inverse discrete Fourier transform (IDFT) matrix. Therefore, by pre-coding the signal channels via IDFT, one is able to generate the super-modes for the MCFs with circularly distributed cores. © 2014 Optical Society of America.

Gu W.-J.,Central China Normal University | Li G.-X.,Central China Normal University | Yang Y.-P.,Tongji University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We investigate the generation of squeezed states in a movable mirror in dissipative optomechanics in which the oscillating mirror modulates both the resonance frequency and the linewidth of the cavity mode. Via feeding broadband squeezed-vacuum light accompanying a coherent driving laser field into the cavity, the master equation for the cavity-mirror system is derived by following the general reservoir theory. When the mirror is weakly coupled to the cavity mode, we find that the driven cavity field can effectively perform as a squeezed-vacuum reservoir for the movable mirror via utilizing the completely destructive interference of quantum noise. Efficient transfer of squeezing from the light to the movable mirror occurs, irrespective of the ratio between the cavity damping rate and the mechanical frequency. Moreover, when the mirror is moderately coupled to the cavity mode, photonic excitation can preclude the completely destructive interference of quantum noise. As a consequence, the mirror deviates from the ideal squeezed state. © 2013 American Physical Society.

Zheng H.,National University of Singapore | Zheng H.,Tongji University | Neo C.Y.,National University of Singapore | Ouyang J.,National University of Singapore
ACS Applied Materials and Interfaces | Year: 2013

To increase the open-circuit voltage (Voc) of dye-sensitized solar cells (DSCs), it is crucial to enhance the photovoltaic efficiency of DSCs. Here, we report an effective method to significantly improve the V oc and photovoltaic efficiency of DSCs by using gel-coated composites of reduced graphene oxide (rGO) and single-walled carbon nanotubes (SWCNTs) as the counter electrode. Gel-coated rGO-SWCNT composites outperform Pt, rGO and SWCNTs in catalyzing the reduction of I3 - and functioning as the counter electrode of DSCs. The Voc and power conversion efficiency (PCE) are 0.86 V and 8.37% for fresh DSCs with the composite of 80 wt % rGO and 20 wt % SWCNTs, significantly higher than those (Voc = 0.77 V, PCE = 7.79%) of control DSCs with Pt fabricated by pyrolysis as the counter electrode. The Voc value of DSCs with rGO-SWCNT composites as the counter electrode further increases to 0.90 V after one week. The high Voc and PCE are ascribed to the synergetic effects of rGO and SWCNTs in reducing the overpotential of the I3 - reduction. RGO with high specific surface area can have high electrocatalytic activity, whereas SWCNTs give rise to high conductivity for the composites and facilitate the penetration of the redox species into rGO sheets by preventing the agglomeration of the rGO sheets. To the best of our knowledge, this is the first time to report iodide/triiodide DSCs with both high Voc and PCE. © 2013 American Chemical Society.

In this paper, we propose to generate/detect orbital angular momentum (OAM) states based on the multimode interference (MMI) effect in a piece of ring core fiber. A comprehensive theory for the MMI process inside ring core fibers is presented. The MMI process inside ring core fibers will convert one input image into multiple equally spaced duplicated output images. After phase adjustment by a fixed phase shifter array, these output images will stimulate OAM states in the ring core fiber or in free space. Henceforth, a novel OAM multiplexer/de-multiplexer (MUX/DEMUX) can be realized by a piece of ring core fiber and a fixed phase shifters array. © 2015 Optical Society of America.

Shi Q.,Tongji University | Blomquist T.,Umea University
International Journal of Project Management | Year: 2012

As an alternative solution, the Dependency Structure Matrix (DSM) is a useful tool in project scheduling when approaching information dependency issues between activities. However, the current DSM approach faces the dilemma that the overlap of activities cannot be precisely estimated in the planning stage of a project, and the solution calls for a robust methodology for managing schedules within uncertain conditions of information dependency. The aim of our research is to propose an approach that utilizes fuzzy set theory to solve the problem within an uncertain environment. As an extension of traditional DSM-based scheduling, we describe the overlap and duration of activities as fuzzy numbers and put forth a systematic algorithm to calculate the time variables of activities and project duration thereof. An example is also provided to demonstrate the effectiveness of the algorithm. © 2011 APM and IPMA and Elsevier Ltd.

STUDY DESIGN.: Bibliometric analysis. OBJECTIVE.: This study aimed to reveal the characteristics of world productivity in the field of minimally invasive spine surgery (MISS) research and to provide a general picture for surgeons and researchers. SUMMARY OF BACKGROUND DATA.: Significant growth has been observed in the field of minimally invasive spine surgery research in recent years. However, bibliometric studies concerning the quantity and quality of articles published in MISS journals are scarce. METHODS.: All the data concerning MISS in this study originate from the Web of Science (Thomson Reuters, New York, USA) without restrictions. All selected literates were evaluated in the following aspects: publication year, publication journals, author, times cited, Web of Science category, countries/territories. RESULTS.: A total number of 2051 articles were published worldwide. The articles published during 2000 to 2015 are more than 11.28 times when compared to those published before 2000. The United States published the largest number of articles (855/2051, 41.7%), followed by Germany (245/2051, 11.9%), South Korea (160/2051, 7.8%), China (147/2051, 7.2%), Japan (108/2051, 5.2%) and had the highest total citations (16626). Additionally, the United States had the highest average citations per article (12.14), followed by Japan (11.98), Germany (11.19), South Korea (11.04) and China (10.95). High income countries published 98.73% of articles, upper middle income countries published 0.24 % of articles and middle income countries published 1.03% of articles. CONCLUSIONS.: The time trend for the number of MISS articles showed a significant increase over time with an average of 93.23 articles per year. The United States was the most productive country and had the highest average citations per article. Among related journals, SPINE published the largest number of articles in MISS research and was the most popular one in the top 5 countries.Level of Evidence: 5 Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.

In this paper, super-modes inside multi-core fibers with circularly distributed cores are analyzed in detail. Cores are arranged within one ring, two rings, and multiple rings. Also, MCFs with a center core embedded inside the rings are discussed. In these analyses, analytical formulas are derived for the propagation constants as well as the modal distribution vectors of the super-modes. © 2014 Optical Society of America.

Yu H.-Y.,Tongji University
Journal of Iron and Steel Research International | Year: 2013

In order to uncover the mechanism of elastic modulus degradation during plastic deformation, uniaxial tensile test of transformation-induced plasticity (TRIP) steels under different prestrain levels was carried out. The real elastic modulus unloaded at each prestrain was calculated by linearly fitting. The microstructure evolution with plastic strain and the fracture morphology were monitored by using a scanning electron microscope (SEM). Dislocation density and its distribution were detected under a transmission electron microscope (TEM). Microscopic mechanism of the elastic modulus degradation of TRIP steels was discussed in detail. Experimental results indicated that the investigated TRIP600 steel was of severe elastic modulus degradation during plastic deformation. The new-born martensite distributed among the retained austenite, resulting in the combination of good ductility and high strength for TRIP steels. It was the change of dislocation movement that induced the variation of atomic binding force and finally led to the variation of elastic modulus. © 2013 Central Iron and Steel Research Institute.

Ming Z.,Xidian University | Zhou M.,Tongji University | Zhou M.,New Jersey Institute of Technology
IEEE Transactions on Industrial Electronics | Year: 2011

Motivated by the method to analyze the impact of dead time in hard-switching converters, this paper, for the first time, analyzes the impact of zero-voltage notches on the outputs of soft-switching pulsewidth modulation (PWM) converters. It proves that the output distortion of soft-switching converters due to their deviation voltage is independent of the direction of their output current. Hence, their compensation strategies require no sensor to detect the current's direction, which is required by dead-time compensation methods in hard-switching converters. A simple yet effective compensation algorithm is presented for soft-switching converters. The analysis result and effectiveness of the proposed algorithm are experimentally verified via a three-phase inverter that represents an important class of converters. © 2010 IEEE.

Yang Y.,Jiaxing University | Kuang C.,Tongji University
European Journal of Organic Chemistry | Year: 2014

A new efficient method for the direct alkenylation of 3-arylsydnones by palladium-catalyzed C-H functionalization was developed. The reaction proceeded smoothly at room temperature and delivered the product in yields up to 83%. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Feng J.,Tongji University
Current protocols in bioinformatics / editoral board, Andreas D. Baxevanis ... [et al.] | Year: 2011

Model-based Analysis of ChIP-Seq (MACS) is a command-line tool designed by X. Shirley Liu and colleagues to analyze data generated by ChIP-Seq experiments in eukaryotes, especially mammals. MACS can be used to identify transcription factor binding sites and histone modification-enriched regions if the ChIP-Seq data, with or without control samples, are given. This unit describes two basic protocols that provide detailed information on how to use MACS to identify either the binding sites of a transcription factor or the enriched regions of a histone modification with broad peaks. Furthermore, the basic ideas for the MACS algorithm and its appropriate usage are discussed.

The objective of the present investigation was to evaluate the antibacterial properties and the biocompatibility of composite electrospun nanofibrous membranes (NFMs) with low-molecular-weight fish scale collagen peptides (FSCP) and chito-oligosaccharide (COS), to determine their potential for use as wound dressings. Low-molecular-weight FSCP were combined with COS to prepare nanofibers by electrospinning, and polyvinyl alcohol (PVA) was used for enhancing fiber-forming ability. Transmission electron microscope and scanning electron microscope methods were used to observe bacterial adhesion and the bacterial cell membrane. Fibroblast cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The best FSCP/COS mass ratio for electrospinning was 2:1, and the nanofibers had small dimensions ranging from 50 to 100 nm. The NFM showed good antibacterial activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The antibacterial activity against S. aureus was higher than against E. coli. The pili and adhesive fimbriae of E. coli promoted bacterial adhesion to the NFM surfaces, and S. aureus biofilms aided S. aureus adhesion on the surface of NFMs. Damage to the bacterial cell membrane indicates that the NFMs could lead to the release of intracellular materials, particularly with S. aureus. In addition, FSCP/COS NFM rapidly increased the permeability of the outer membranes of E. coli. The electrospun NFM with FSCP and COS had good biocompatibility in vitro and supported proliferation of human skin fibroblasts. FSCP are superior to mammalian collagen, and have feasibility and potency for wound dressings. FSCP/COS NFMs had good anti-bactericidal activity that improved with increased COS, and showed good biocompatibility in vitro and supported the proliferation of fibroblasts.

Recently, Biswas et al. (Phys Wave Phenom 19:24–29, 2011) derived exact bright and dark solitary solutions for the Rosenau–Kawahara equation with power law nonlinearity, and Hu et al. (Adv Math Phys 11, Article ID 217393, 2014) proposed two conservative finite difference schemes for the usual Rosenau–Kawahara equation. In this paper, we obtain another set of exact solitary solutions for the Rosenau–Kawahara equation with power law nonlinearity. More importantly, a conservative finite difference method is presented. The fundamental energy conservation law is preserved by the current numerical scheme. And the existence and uniqueness of the numerical solution are proved. The convergence and stability of the numerical solution are also shown. The method is second-order convergent both in time and in space. Finally, numerical results confirm well with the theoretical results and show that the current method can be well used to study the solitary wave at long time. © 2015 Springer Science+Business Media Dordrecht

Hot springs at Gongxiaoshe and Zhuyuan (maximum temperatures of 73 to 84°C, respectively) are characterized by deposits formed of calcite, aragonite, non-crystalline Si-Mg-Fe deposits, and minor amounts of barite and gypsum. The deposits at Gongxiaoshe are formed largely of alternating calcite and aragonite laminae, whereas those at Zhuyuan are formed largely of calcite. The calcite is in the form of: (i) pseudodendrites that grew as sub-crystals stacked upon each other; and (ii) unattached euhedral and incompletely formed dodecahedral and rhombohedral crystals. Amorphous CaCO3, formed of nanoparticles <1 μm long, is common in some of the Zhuyuan deposits, but minor in the Gongxiaoshe deposits. The morphologically diverse arrays of aragonite crystals that lie parallel to bedding were not nucleated on a growth surface. Many substrates in these deposits are covered with reticulate coatings that are formed largely of Si and Mg with minor Fe and micro-granular coatings that are formed largely of Si and Fe. Biofilms, with their extracellular polymeric substances, and microbes are common at both springs. The compositionally and crystallographically diverse precipitates at these two springs are attributed to a biologically influenced model with precipitation taking place in micro-domains that developed in the extracellular polymeric substances. According to this model, precipitation varied at the micron-scale influenced by the elemental concentrations that developed in the hydrogel of extracellular polymeric substances. Critically, the very low preservation potential of the extracellular polymeric substance and its formative microbes means that the precipitates will rapidly lose evidence of their biotic origin. The compositional diversity of the precipitates, the crystallographic diversity of the calcite and aragonite with numerous incompletely formed crystals, and local concentrations of Si, Mg and Fe may, however, serve as proxies of that biologically influenced precipitation. © 2013 International Association of Sedimentologists.

Liu Z.,Virginia Polytechnic Institute and State University | Ye W.,Virginia Polytechnic Institute and State University | Ye W.,Tongji University | Little J.C.,Virginia Polytechnic Institute and State University
Building and Environment | Year: 2013

Volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) constitute important classes of indoor air contaminants and characterizing their emissions from building materials and consumer products is of interest for risk assessment and the development of environmentally benign products. Compared with emission chamber studies, emission models provide a more cost effective and powerful way to examine the emission behavior of VOCs and SVOCs. The objective of this paper is to review existing mechanistic models for predicting VOC and SVOC emissions from various sources, investigate their differences and similarities, and discuss the mass-transfer mechanisms on which the models are constructed. Because the usefulness of the emission models largely depends on the availability and reliability of model parameters, techniques for estimating key model parameters are also reviewed. The models covered in this review fall into three categories: models for VOC emissions from solid materials; models for VOC emissions from liquid materials; and models for SVOC emissions. VOC and SVOC emissions can be modeled within a consistent mass-transfer framework with the three model categories being intimately related. While substantial advances have been made in developing predictive models and understanding emission mechanisms, large knowledge gaps exist and further research is needed. © 2013 Elsevier Ltd.

Pan Z.,Tongji University | Li B.,Nanyang Technological University | Lu Z.,Nanjing Southeast University
Engineering Structures | Year: 2014

Beam deflections in cases of diagonal and bending cracking of reinforced concrete (RC) beams can be attributed equally to shear and flexural deformations. However, the extent of contribution by shear deformation is hard to quantify and is often underestimated in practical design. To address this, a quantitative analysis of the effect of shear deformation was conducted, considering the effect of tension stiffening after diagonal cracking, and a formula to derive effective shear stiffness is proposed. Five RC beams, comprising of three RC T-section beams with thin web and two RC rectangular beams, were tested to verify the theoretical models with minimum crack angle and total deflection as key points of comparison. The fully cracked responses were analyzed using truss model analogies while exact models applied depended on the crack angle. Results show that shear contribution to the total deflection in the diagonally cracked RC beam is significant. © 2013 Elsevier Ltd.

Lu L.S.,Tongji University
European review for medical and pharmacological sciences | Year: 2012

There is emerging evidence that matrix metalloproteinase (MMP)-2 plays a crucial role in cancer invasion/metastasis. However, little evidence is available about the connections of multidrug resistance protein 1 (MDR1) and cancer invasion/metastasis so far. To investigate the expression of MDR1 and MMP2 in primary breast tumors and their corresponding metastasized lymph nodes. Only lymph nodes which were pathologically identified as metastases were included in this study to compare with the corresponding primary tumor. We determined the expression of MDR1 and MMP2 in primary breast tumor and its metastasized lymph node specimens of 21 patients. The quantitative real-time polymerase chain reaction (Q-RT-PCR) technique was used to assess the MDR1 and MMP2 RNA expression levels in primary breast tumor and lymph nodal specimens. Target gene copies were normalized using beta-actin (beta-actin) gene copies. Tumor characteristics and number of metastatic lymph nodes were gathered from the pathology reports. The Q-RT-PCR data showed that MDR1 expression in metastasized lymph node was higher than that of their corresponding primary tumors (p < 0.05), MMP2 expression in metastasized lymph nodes was also even higher compared with their matched primary tumors (p < 0.01). But SPSS bivariate correlation analysis revealed that MDR1 expression in lymph node was not correlated with MMP-2 expression in lymph node, number of metastasized lymph nodes and tumor size (p > 0.05). MDR1 expression in primary tumors was highly correlated with in corresponding lymph node metastases (p < 0.01 r = 0.795). All those indicated that MMP-2 should play an important role in the lymph node metastasis. However, further clinical studies with larger sample size need to be performed to verify these findings.

Huang Z.-M.,Tongji University | Liu L.,Zernike Institute for Advanced Materials
International Journal of Mechanical Sciences | Year: 2014

A long standing and very challenging problem is to predict the ultimate strength of a fibrous laminate under arbitrary load condition only based on the mechanical properties of its constituents measured independently. Although the Bridging Model is unique for calculating the internal stresses in the constituent fiber and resin (which stands for a matrix material throughout this paper) materials subjected to any load including a temperature variation, the in situ mechanical properties of the constituents must be provided beforehand. A unidirectional (UD) composite exhibits a transverse tensile strength smaller than the tensile strength of the monolithic resin material, indicating that the in situ tensile strength of the resin in the transverse direction is different from that measured using monolithic material specimens. This is attributed to a stress concentration. The stress concentration factors (SCFs) of the resin material in a RVE (representative volume element) due to occurrence of the fiber are determined in terms of elasticity theory. The resin in situ tensile, compressive, and shear strengths in the transverse plane are obtained by the corresponding resin strengths measured independently divided by the respective SCFs, whereas the resin in situ longitudinal strengths together with all the other constituent properties are the same as their original counterparts. Using these originally provided constituent properties as input data, the Bridging Model has been applied to analyze the second World-Wide Failure Exercise (WWFE-II) problems. The model's predictions for all the problems have been compared with available experimental data. Favorable correlation has been found. © 2013 Elsevier Ltd.

Wei Y.,Zhejiang University | Zhang Z.,Tongji University
Land Use Policy | Year: 2012

The fragmentation of construction land due to decentralised urban development, disorderly mixed land use, and large-scale transportation infrastructure poses a threat to urban integrity. There is a need to quantify the fragmentation level in a consistent way for inclusion in planning-related decisions. In the context of China's urban sprawl, this study develops a quantitative and intuitive index approach that planners can use to analyse multiple fragmentation features of construction land within urban areas. The approach can be used in planning policy reviews for timely land-use assessment and can be integrated into urban planning processes for developing strategic land-use scenarios. The method was applied in Shunde, a typical urban area in southern China, and construction-land fragmentation and its impacts on environmental quality were analysed. The results show that the entire built-up area in Shunde displays a high level of fragmentation. Patches of industrial and rural residence have been identified specifically higher fragmentation level. The shortage of available construction land makes land consolidation within built-up areas very important in planning Shunde's future development. Moreover, the land shortage requires the progressive reduction of construction land fragmentation. The results of the study also indicate that although land fragmentation has been affected by transportation infrastructure and the existence of rivers and hills in this region, decentralised decisions from hierarchical local governance regimes have greatly exacerbated this situation. Shunde provides examples of typical land-use problems associated with quasi-urbanised regions in China; construction-land fragmentation is a greater determinant for the sustainable development of urban and rural areas than construction-land growth. © 2011 Elsevier Ltd.

Yuan H.,Tongji University | Shim T.,University of Michigan
International Journal of Precision Engineering and Manufacturing | Year: 2013

In this paper, by explicitly considering a dynamic model of the robots, the coefficients of trajectories are determined by boundary conditions, optimal performance index and collision avoidance conditions. The planned trajectory is feasible and has a closed loop expression, which is efficient for real-time updating. There are two main improvements compared with existing parametric approaches. Firstly, most of existing methods use the kinematic models of the robots, which could cause curvature discontinuities when trajectories are updated in real-time. Secondly, in some existing parametric methods, the initial position and ending waypoints cannot be aligned vertically due to singularities. The approach proposed in this paper overcomes this limitation. Computer simulations verified the effectiveness of the proposed method. © 2013 Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg.

Chern M.-S.,National Tsing Hua University | Pan Q.,Tongji University | Teng J.-T.,William Paterson University | Chan Y.-L.,Asia University, Taiwan | Chen S.-C.,National Chengchi University
International Journal of Production Economics | Year: 2013

In practice, vendors (or sellers) often offer their buyers a fixed credit period to settle the account. The benefits of trade credit are not only to attract new buyers but also to avoid lasting price competition. On the other hand, the policy of granting a permissible delay adds not only an additional cost but also an additional dimension of default risk to vendors. In this paper, we will incorporate the fact that granting a permissible delay has a positive impact on demand but negative impacts on both costs and default risks to establish vendor-buyer supply chain models. Then we will derive the necessary and sufficient conditions to obtain the optimal solution for both the vendor and the buyer under non-cooperative Stackelberg equilibrium. Finally, we will use two numerical examples to show that (1) granting a permissible delay may significantly improve profits for both the vendor and the buyer, (2) the sensitivity analysis on the optimal solution with respect to each parameter, and (3) the comparisons between Nash and Stackelberg solutions. © 2013 Elsevier B.V. All rights reserved.

Li S.,Tongji University
Journal of Pipeline Systems Engineering and Practice | Year: 2013

Horizontal directional drilling (HDD) is an important technology for the placement of municipal pipelines, including water and sewer lines. This paper describes the in situ monitoring of the installation of a gas pipeline during HDD construction by using a gyroscope position-detection system and fiber optic sensing technique. The three dimensional (3D) spatial coordinates of the overall pipeline have been measured, allowing calculation of the product pipe strains and corresponding axial forces and moments during the installation. The results verify that the longitudinal strains and the section moments are sharply increased as the pipe traverses the bore path, with a simultaneous bend in the horizontal and vertical planes. The recorded data is available for the further theoretical analysis, as desired, and the monitoring strategy can be adopted for other similar projects. © 2013 American Society of Civil Engineers.

Chen J.,Tongji University | Georgakis C.T.,Technical University of Denmark
Journal of Sound and Vibration | Year: 2013

With wind turbines growing in size and cost, it is necessary to reduce their dynamic responses and improve their fatigue lifetime. A passive tuned-mass damper (TMD) is a very efficient solution for vibration control in structures subjected to wind excitations. In this study, a tuned rolling-ball damper characterized by single or multiple steel balls rolling in a spherical container is proposed to be mounted on the top of wind turbines to reduce the wind-induced vibration. A 1/20 scale shaking table model was developed to evaluate the control effectiveness of the damper. The wind-induced dynamic responses of the test model with and without TMD were obtained from the shaking table tests. The test results indicated that the rolling-ball dampers could effectively suppress the wind-induced vibration of wind turbines. The damper with three balls in one container had better control effectiveness than that with only one ball because of the impact effect and the rolling friction. The control effectiveness of the damper cannot be improved further when the number of balls is increased beyond a certain point. © 2013 Elsevier Ltd. All rights reserved.

Wang S.,Tongji University
International Journal of Production Research | Year: 2013

This paper deals with an integrated bi-objective optimisation problem for production scheduling and preventive maintenance in a single-machine context with sequence-dependent setup times. To model its increasing failure rate, the time to failure of the machine is subject to Weibull distribution. The two objectives are to minimise the total expected completion time of jobs and to minimise the maximum of expected times of failure of the machine at the same time. During the setup times, preventive maintenance activities are supposed to be performed simultaneously. Due to the assumption of non-preemptive job processing, three resolution policies are adapted to deal with the conflicts arising between job processing and maintenance activities. Two decisions are to be taken at the same time: find the permutation of jobs and determine when to perform the preventive maintenance. To solve this integrated problem, two well-known evolutionary genetic algorithms are compared to find an approximation of the Pareto-optimal front, in terms of standard multi-objective metrics. The results of extensive computational experiments show the promising performance of the adapted algorithms. © 2013 Taylor and Francis.

Yu R.,University of Central Florida | Yu R.,Tongji University | Abdel-Aty M.,University of Central Florida
Accident Analysis and Prevention | Year: 2013

The Bayesian inference method has been frequently adopted to develop safety performance functions. One advantage of the Bayesian inference is that prior information for the independent variables can be included in the inference procedures. However, there are few studies that discussed how to formulate informative priors for the independent variables and evaluated the effects of incorporating informative priors in developing safety performance functions. This paper addresses this deficiency by introducing four approaches of developing informative priors for the independent variables based on historical data and expert experience. Merits of these informative priors have been tested along with two types of Bayesian hierarchical models (Poisson-gamma and Poisson-lognormal models). Deviance information criterion (DIC), R-square values, and coefficients of variance for the estimations were utilized as evaluation measures to select the best model(s). Comparison across the models indicated that the Poisson-gamma model is superior with a better model fit and it is much more robust with the informative priors. Moreover, the two-stage Bayesian updating informative priors provided the best goodness-of-fit and coefficient estimation accuracies. Furthermore, informative priors for the inverse dispersion parameter have also been introduced and tested. Different types of informative priors' effects on the model estimations and goodness-of-fit have been compared and concluded. Finally, based on the results, recommendations for future research topics and study applications have been made. © 2013 Elsevier Ltd. All rights reserved.

Zhang Y.,Tongji University
Asian Journal of Control | Year: 2013

This paper investigates robust exponential stability for discrete-time delay impulsive systems with parametric uncertainties. The parametric uncertainties in the systems are assumed to be time varying and norm bounded. Using Lyapunov functionals, some robust exponential stability criteria are given. It is shown that the time interval between the nearest two impulses should be small enough, i.e., impulses must act frequently, when the impulses are employed to stabilize the original impulse-free system that is not robustly stable. Conversely, when the original system without impulses is robustly stable, the time interval between the nearest two impulses should be large enough to let the system with impulsive perturbations retain its stability property. It should be noted that this is the first time that impulsive robust exponential stabilization results are given via Lyapunov functionals for discrete-time uncertain delay impulsive systems. Some examples, including an example which cannot be studied by the existing results, are also presented to illustrate the effectiveness of the obtained results. © 2012 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society.

Hu B.,Hefei University of Technology | Hu B.,Tongji University
Engineering Structures | Year: 2013

This paper presents the assessment results of existing criteria for sufficiently/insufficiently fiber-reinforced polymer (FRP)-confined concrete, develops a unified ultimate axial stress model and proposes an improved criterion. The existing criteria for FRP-confined concrete in circular and rectangular columns are reviewed. A large database has been established by collecting the available experimental results from the open literature for evaluation of the existing criteria. The assessment results indicate that there is still room for improvement in the existing criteria, especially in those for rectangular specimens. An improved criterion for FRP-confined concrete in both circular and rectangular columns is proposed on the basis of the existing criteria and deduced from the unified ultimate axial stress model which is developed in this paper as well. Comparisons between the criterion predictions and the test results demonstrate the accuracy of the proposed criterion. © 2012 Elsevier Ltd.

Yu F.,Shanghai JiaoTong University | Ma J.,Tongji University | Wu Y.,Shanghai JiaoTong University
Journal of Hazardous Materials | Year: 2011

The purified and oxidized multi-walled carbon nanotubes (MWCNTs) with different oxygen contents are employed as adsorbents to study their physicochemical properties and adsorption behaviors of toluene, ethylbenzene and m-xylene (TEX) in aqueous solutions. The results demonstrate that adsorption capacity is significantly enhanced for 3.2% surface oxygen, but is dramatically reduced for 5.9% oxygen concentration. The adsorption kinetics is investigated and fitted with pseudo-second-order model. The adsorption isotherms are found to be fitted with Langmuir model. More interestingly, with the increasing of surface oxygen content, maximum adsorption capacities firstly increased, and then, began to decrease. In the first stage, dispersion is the most important factor. A better dispersive interaction increases the available adsorption sites, which consequently can be favorable for the aqueous phase adsorption. Therefore, maximum adsorption capacity is remarkably enhanced with the increasing of oxygen content, which is according with our results. However, in the second stage, when oxygen content increases to a certain extent, hydroxyl groups cause water clusters formation on the surface or tube end of MWCNTs, which hinder the interaction between TEX and MWCNTs. Consequently, more oxygen content leads to the decrease in maximum adsorption capacity. The decrease indicates that the formation of water clusters plays a more important role than the better dispersion of MWCNTs for TEX adsorption. © 2011 Elsevier B.V.

Yuan S.,Tongji University
International Journal of Mechanical Engineering Education | Year: 2013

Websites are increasingly becoming a major source of information. Nowadays, many international design schools utilize their websites to help promote their programs and attract prospective students. However, design schools in China are lagging behind in using websites effectively. Five typical websites of Chinese design schools were analyzed to identify existing problems, and a study was carried out on 10 top design schools located in the USA, Europe, and Asia, to synthesize best practices in website design. End-users' information requirements were captured by a questionnaire distributed to 112 design students in China. It was found that Chinese students were most interested in project details and portfolios (of both graduates and teachers) when browsing design schools' websites. An open-ended card-sorting test with 22 navigation tags was conducted among seven testers. The studies resulted in a set of cards that provided a common information category structure, which was then evaluated by another card-sorting test. Strategies are proposed to help Chinese design schools develop more effective websites. © Manchester University Press.

Yang D.,Tongji University | Ye S.,East China Normal University | Ge J.,East China Normal University
Advanced Functional Materials | Year: 2014

An efficient and straightforward method is developed to prepare a mechanochromic photonic gel by fixing the metastable SiO2 colloidal crystalline array (CCA) in the mixture of ethylene glycol (EG) and poly(ethylene glycol) methacrylate (PEGMA) through photopolymerization. Thanks to the recent fabrication of solvent-wrapped, metastable CCA, a high volume fraction of EG (46%) is introduced to the photonic gel before particle assembly, but not by swelling after polymerization, which leads to a more deformable composite than most reported opal gels. Compared to traditional photonic gels, this opal gel not only has improved mechanochromic sensitivity to weak external force and extended color tuning range from red to blue (Δλ = 150 nm), but also possesses fast and reversible response in millisecond level (20-200 ms), repeatable reflection signals in cycling and fatigue tests, and good resolution in response to localized deformation, which renders it an ideal deformation-based photonic display screen. A new trigger system is designed to solve the large deformation causing color fading in conventional mechanochromic gels and brilliant red, green, and blue (RGB) pixels can be conveniently manipulated by 'pushing' operations. A mechanochromic photonic gel is prepared by fixing metastable SiO2 colloidal crystalline array in the mixture of EG and PEGMA through photopolymerization. Compared to traditional opal gels, it has improved mechanochromic sensitivity, a broad color tuning range, fast response, repeatable reflection signals in cycling and fatigue tests, and good resolution for localized deformation, which makes it a good deformation-based photonic display panel with controllable RGB pixels. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Liu D.,Xidian University | Li Z.,Xidian University | Zhou M.,Tongji University | Zhou M.,New Jersey Institute of Technology
Automatica | Year: 2013

The work proposes a synthesis method of supervisors for flexible manufacturing systems modeled by a class of generalized Petri nets. A concept of resource usage ratios (RU-ratios) is first presented to describe the occupation degree of a resource by an operation. Next, an intrinsically live structure characterized by a special numerical relationship between arc-weights and initial markings is investigated from a perspective of RU-ratios. Then, a new kind of supervisors is synthesized on the ground of the generic nature of the intrinsically live structure. Such a supervisor can achieve the purposes of both liveness-enforcement and resource usage ratio-enforcement of the system under consideration. Given a plant, it is easy to determine the topological structure of such a supervisor and the number of monitors is bounded by that of resources used in the plant. In addition, when the configuration of the plant model changes, the supervisor can be reusable through adjusting control parameters only without rearrangement of connections. This makes it easy enough and intuitive to be used by industrial practitioners. Instead of maximal behavioral permissiveness, it pursues a precise usage of shared resources that are limited and valuable. Several examples are used to illustrate the proposed methods. © 2013 Elsevier Ltd. All rights reserved.

Boyce D.,Northwestern University | Xie J.,Tongji University
Transportation Research Part A: Policy and Practice | Year: 2013

Static user-equilibrium traffic assignment, the standard method for predicting traffic flows on urban road networks, is based on the principle that drivers choose their own least cost routes from their origins to their destinations. This principle may be formally described by user-equilibrium conditions, which correspond to the optimal solution to a nonlinear minimization problem. Although the total flows on links of the road network are uniquely determined by this formulation, multiple user-class link flows, as well as route flows, are not. Nevertheless, professionals frequently use class link flows output by their software for project evaluation, and class route flows to perform select link analyses. These applications may result in misleading findings, for example, in scenario analyses. An additional assumption may be imposed to determine these user class link flows and route flows uniquely. A possible assumption is the condition of proportionality, namely that the proportion of vehicles on each of two alternative, equal-cost segments (sequences of links) should be the same regardless of their user class, origin or destination. This paper compares two assignments in which the order of the car and truck trip matrices was specified as car followed by truck, and truck followed by car. Although the total link flows for the two assignments are effectively equal, substantial differences exist between the user class link flows determined by the different orderings of the matrices. Post-processing to impose the condition of proportionality on the class O-D flows removes about 90% of these differences. Analyses of class link flows of cars and trucks before and after imposing the condition of proportionality for one of these assignments reveal that about half of all links experience differences in user class flows, ranging up to ±300. vph. These findings offer insights into the magnitude of the differences arising from the non-uniqueness of class link flows, and identify which links are subject to differences. Imposing the condition of proportionality in multi-class traffic assignments is recommended in travel forecasting practice. © 2013 Elsevier Ltd.

Song Z.,Shanghai Ocean University | Xu J.,Tongji University
Science China Technological Sciences | Year: 2014

In this paper, we investigate an inertial two-neural coupling system with multiple delays. We analyze the number of equilibrium points and demonstrate the corresponding pitchfork bifurcation. Results show that the system has a unique equilibrium as well as three equilibria for different values of coupling weights. The local asymptotic stability of the equilibrium point is studied using the corresponding characteristic equation. We find that multiple delays can induce the system to exhibit stable switching between the resting state and periodic motion. Stability regions with delay-dependence are exhibited in the parameter plane of the time delays employing the Hopf bifurcation curves. To obtain the global perspective of the system dynamics, stability and periodic activity involving multiple equilibria are investigated by analyzing the intersection points of the pitchfork and Hopf bifurcation curves, called the Bogdanov-Takens (BT) bifurcation. The homoclinic bifurcation and the fold bifurcation of limit cycle are obtained using the BT theoretical results of the third-order normal form. Finally, numerical simulations are provided to support the theoretical analyses. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.

Fan Z.,Tongji University
Zhonghua kou qiang yi xue za zhi = Zhonghua kouqiang yixue zazhi = Chinese journal of stomatology | Year: 2010

To determine whether the roughness of titanium implant can influence its osseointegration by affecting the growth, alkaline phosphatase (ALP) production and expression of core binding factor alpha 1 subunit (Cbfα1) of osteoblasts. Totally 48 titanium disc specimens, 15 mm in diameter and 2 mm in thickness, were included in the study and divided equally into 4 groups with 12 specimens in each group. Specimens were coarsened by sandblasting with carborundum granula and acid etching with mixing liquid of hydrochloric acid and sulphuric acid under diverse conditions. In the four groups, three were treated with different surface roughness: micro-roughness [(1.00 ± 0.20) μm], midrange roughness [(1.67 ± 0.08) μm] and severe roughness [(2.40 ± 0.20) μm], while the group untreated with surface roughness [(0.12 ± 0.03) μm] was set as control. Scanning electron microscope, acridine orange fluorescence staining and coomassie brilliant blue staining were used to observe morphology and growth of osteoblasts incubating on these specimens. Enzyme linked immunosorbent assay (ELISA) and fluorescence quantitative real-time polymerase chain reaction were used to evaluate ALP production and gene expression of Cbfα1 of osteoblasts among different groups. Growth, ALP production and Cbfα1 mRNA expression of osteoblasts in experimental groups were higher than those in control group (P < 0.05). Significant differences of these data were also found among three experimental groups (P < 0.05). Midrange roughness group showed the highest level of gene expression of Cbfα1 mRNA, which was 0.93 ± 0.03. While that in the micro-roughness group (0.50 ± 0.03) came second, and the severe roughness group had the lowest data, which was 0.37 ± 0.07. Results indicated that rough surface was more suitable for the adherence and propagation of the osteoblasts than smooth one did. Surface with roughness of 1-2 μm may be a better choice for osseointegration between osteoblasts and dental implants than others are.

Guo L.,Shanghai Finance University | Song Z.-G.,Shanghai Ocean University | Xu J.,Tongji University
Communications in Nonlinear Science and Numerical Simulation | Year: 2014

In this paper, we present a Leslie-Gower type of food chain system composed of three species, which are resource, consumer, and predator, respectively. The digestion time delays corresponding to consumer-eat-resource and predator-eat-consumer are introduced for more realistic consideration. It is called the resource digestion delay (RDD) and consumer digestion delay (CDD) for simplicity. Analyzing the corresponding characteristic equation, the stabilities of the boundary and interior equilibrium points are studied. The food chain system exhibits the species coexistence for the small values of digestion delays. Large RDD/CDD may destabilize the species coexistence and induce the system dynamic into recurrent bloom or system collapse. Further, the present of multiple delays can control species population into the stable coexistence. To investigate the effect of time delays on the recurrent bloom of species population, the Hopf bifurcation and periodic solution are investigated in detail in terms of the central manifold reduction and normal form method. Finally, numerical simulations are performed to display some complex dynamics, which include multiple periodic solution and chaos motion for the different values of system parameters. The system dynamic behavior evolves into the chaos motion by employing the period-doubling bifurcation. © 2014 Elsevier B.V.

Yu G.R.,Tongji University
Zhonghua wai ke za zhi [Chinese journal of surgery] | Year: 2010

To explore the operative methods of malunited or nonunited talus fractures. Twenty-two patients of malunions or nonunions after displaced talar fractures were treated from January 2000 to January 2008. There were 17 males and 5 females with an average age of 34 years (ranged from 15 to 52 years). According to classification of posttraumatic talar deformities (Zwipp 2003), there were 10 cases of type I (malunion and/or joint displacement), 8 cases of type II (nonunion with joint displacement), 4 cases of type III (type I/II with partial AVN). The surgical treatments included open reduction, osteotomy, correction and internal fixation with plate, screw or K-wire, or the ankle, subtalar arthrodesis. Seventeen patients were followed up for 14 months in average (ranged from 12 to 24 months). No wound healing problems or infections were observed. Solid union was obtained without redislocation in all patients. The mean time of bone union was 14 weeks (ranged from 12 to 18 weeks). The mean time of completely weight loading was 14 weeks (ranged from 12 to 18 weeks). The mean AOFAS ankle and hindfoot score increased from 35.4 (ranged from 28.0 to 41.0) to 86.6 (ranged from 78.0 to 98.0). As to posttraumatic talar deformities, surgical treatment can lead to a favorable outcome. According to concrete status of malunions or nonunions after displaced talar fractures, suitable surgical treatment should be applied to obtain satisfactory outcome.

Ye H.,Astrazeneca | Liu Q.,Tongji University | Wei J.,Astrazeneca
PLoS ONE | Year: 2014

Drugs with similar side-effect profiles may share similar therapeutic properties through related mechanisms of action. In this study, a drug-drug network was constructed based on the similarities between their clinical side effects. The indications of a drug may be inferred by the enriched FDA-approved functions of its neighbouring drugs in the network. We systematically screened new indications for 1234 drugs with more than 2 network neighbours, 36.87% of the drugs achieved a performance score of Normalized Discounted Cumulative Gain in the top 5 positions (NDCG@5)≥0.7, which means most of the known FDA-approved indications were well predicted at the top 5 positions. In particular, drugs for diabetes, obesity, laxatives and antimycobacterials had extremely high performance with more than 80% of them achieving NDCG@5≥0.7. Additionally, by manually checking the predicted 1858 drug-indication pairs with Expression Analysis S ystematic Explorer (EASE) score≤10-5 (EASE score is a rigorously modified Fisher exact test p value), we found that 80.73% of such pairs could be verified by preclinical/clinical studies or scientific literature. Furthermore, our method could be extended to predict drugs not covered in the network. We took 98 external drugs not covered in the network as the test sample set. Based on our similarity criteria using side effects, we identified 41 drugs with significant similarities to other drugs in the network. Among them, 36.59% of the drugs achieved NDCG@5≥0.7. In all of the 106 drug-indication pairs with an EASE score≤0.05, 50.94% of them are supported by FDA approval or preclinical/clinical studies. In summary, our method which is based on the indications enriched by network neighbors may provide new clues for drug repositioning using side effects. © 2014 Ye et al.

Gao L.,East China Normal University | Li D.,East China Normal University | Zhang Y.,Tongji University
Journal of Geophysical Research: Biogeosciences | Year: 2012

From September 2009 to August 2010, intensive monthly sampling of nutrients was conducted at two stations at the mouth of the Changjiang (Yangtze River). Particulate organic carbon (POC), particulate nitrogen (PN), and their stable isotope values (δ13C and δ15N) were also measured in selected samples of all months. Most nutrients (nitrate, phosphate, ammonia, and nitrite) as well as POC, PN, and δ13C displayed peak values when the highest or lowest Changjiang monthly discharges occurred, suggesting the Changjiang discharges strongly influence the seasonal variations of these chemicals. The sharply increases in concentrations of ammonia and nitrite in winter probably suggest nitrification was greatly depressed during this cold period. Using five interpolation methods, the annual discharge fluxes of nutrients, POC, and PN from the Changjiang to the East China Sea shelf were calculated. Combining this nutrient data with data from previous studies, the seasonal Mann-Kendall test, in which the influence of seasonal variation was considered, suggests concentrations of nitrate and phosphate in the Changjiang have significantly increased during recent decades at rates of 2.2 M yr -1 and 0.03 M yr-1, respectively; no significant trend for silicate was noted. Decreased POC annual fluxes along with sharply decreased suspended particulate matter yields were also seen in recent years (1993-2010). However, no distinct changes of δ13C, δ15N, and the POC/PN ratio, which describe the particulate organic matter properties, were observed during this period. © 2012. American Geophysical Union. All Rights Reserved.

Xue M.,Tongji University | Xue M.,University of California at Berkeley | Allen R.M.,University of California at Berkeley
Journal of Geophysical Research: Solid Earth | Year: 2010

We present tomographic images of the mantle structure beneath the western United States. Our Dynamic North America Models of P and S velocity structure (DNA07-P and DNA07-S) use teleseismic body waves recorded at ∼600 seismic stations provided by the Earthscope Transportable Array and regional networks. DNA07-P and -S benefit from the unprecedented aperture of the network while maintaining a dense station distribution providing high-resolution body wave imaging of features through the transition zone and into the lower mantle. The main features imaged include (1) the Juan de Fuca subduction system that bottoms at ∼400 km beneath Oregon, implying interaction with the Yellowstone anomaly; (2) a low-velocity conduit beneath Yellowstone National Park that bottoms at 500 km and dips toward the northwest; (3) shallow low-velocity anomalies (upper 200 km) beneath the eastern Snake River Plain (ESRP) and the High Lava Plains, and a deep low-velocity anomaly (>600 km) beneath the ESRP but not Newberry; (4) a low-velocity "slab gap" to ∼400 km depth immediately south of the Mendocino Triple Junction and south of the Gorda slab; and (5) high-velocity "drips" beneath the Transverse Ranges, the southern Central Valley/Sierra Nevada, and central Nevada. These observations reveal extremely heterogeneous mantle structure for the western United States and suggest that we are only just beginning to image the complex interactions between geologic objects. The transportable array allows for analysis of the relationships between these anomalies in an internally consistent single tomographic model. The DNA velocity models are available for download and slicing at http://dna.berkeley.edu. © 2010 by the American Geophysical Union.

To improve the CO(2) fixation efficiency of non-photosynthetic microbial community (NPMC) isolated from sea water under aerobic conditions without hydrogen, the concentration of inorganic compounds as electron donors and their ratios were optimized using response surface methodology design (RSMD). These results indicated that Na(2)S, followed by Na(2)S(2)O(3) and NaNO(2) enhanced the CO(2) fixation by NPMC and the efficiency was increased about 100%, 200% and 200%, respectively. Some interaction between NaNO(2) and Na(2)S(2)O(3), as well as between Na(2)S(2)O(3) and Na(2)S was observed. Central composite RSMD experimentation predicted that the optimal concentration of these inorganic compounds and their ratios was 0.457% NaNO(2), 0.50% Na(2)S(2)O(3) and 1.25% Na(2)S. Under these conditions, the fixed CO(2) was 105.76 mg/L, which obviously exceeded the amount before optimization, as well as that obtained using hydrogen as the electron donor. This indicates that the NPMC using the established electron donors system can effectively fix CO(2) without light and hydrogen gas under aerobic condition. Copyright 2010 Elsevier Ltd. All rights reserved.

Zhang J.,Tongji University | Zhang J.,Hong Kong University of Science and Technology | Zhang L.M.,Hong Kong University of Science and Technology | Tang W.H.,Hong Kong University of Science and Technology
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012

Reliability-based optimization (RBO) intends to minimize the cost involved in a design while satisfying all technical requirements specified by using reliability theory. Although this idea is attractive, its implementation is generally difficult because an accurate evaluation of the reliability constraints is often computationally prohibitive when it is coupled with the minimization of a cost function. This paper suggests an indirect method for RBO of geotechnical systems initially on the basis of the mean first-order reliability method (MFORM). Because reliability analysis with MFORM is very efficient, the computational work involved in RBO is greatly reduced. The major concern about MFORM is that it is not an accurate reliability method. A reliability index mapping function was used to relate the reliability index calculated by MFORM to that calculated by a more accurate method. When the mapping function perfectly reflects the relationship between MFORM reliability index and that from an accurate reliability method, the RBO from MFORM and the original RBO problem are equivalent. When a perfect mapping function cannot be built, a procedure has been suggested to fine-tune the optimal design such that accurate reliability constraints can be maintained in the final optimal design. The proposed method is illustrated with two geotechnical examples: the optimal design of a shallow foundation and a gravity retaining wall. © 2011 American Society of Civil Engineers.

Wang F.,Tongji University | Yang Y.,Houston Methodist Research Institute
Breast Cancer Research and Treatment | Year: 2014

The xCT antiporter is known to be upregulated in 30 % of triple-negative breast cancer (TNBC) cell lines. The xCT-CD44 variant (CD44v) system regulates the levels of reactive oxygen species (ROS) in cancer cells and promotes tumor growth. Here, the role of this antiporter system in relation to chemotherapy was evaluated. MDA-MB-231 and MDA-MB-436 cells were transfected with lentiviral vectors expressing short hairpin RNA against xCT or CD44v. Following doxorubicin treatment, cellular proliferation was monitored, ROS were measured, and intracellular levels of cysteine and glutathione (GSH) were determined using liquid chromatography-mass spectrometry. A TNBC orthotopic tumor model was used to evaluate the impact of xCT-CD44v inhibition on doxorubicin efficacy in vivo. Doxorubicin treatment of TNBC cells caused increased expression of xCT through upregulation of CD44v. Consequently, the intracellular uptake of cystine increased, enabling rapid synthesis of GSH, and neutralization of doxorubicin-induced ROS. Suppression of xCT or CD44v impaired the defense against drug-induced oxidative stress, thereby sensitizing cells to doxorubicin. The importance of the xCT-CD44v in supporting tumor growth during doxorubicin treatment was also demonstrated in an in vivo tumor model of TNBC. These findings suggest that the antiporter system could serve as a target for increasing the anticancer efficacy of conventional therapy in patients with TNBC. © 2014 Springer Science+Business Media.

Human behavior has the positive and negative impact on ecosystem. To study the interaction between ecosystem and behavior system, per-capita energy ecological footprint (EEF) is selected as the ecosystem threshold. Elasticity coefficient of environmental investment (ECEI) and elasticity coefficient of energy consumption (ECEC) represent the positive and negative human impact on ecosystem, respectively. It takes Shanghai, China as the empirical area to implement grey relational analysis of per-capita EEF (consist of coal, coke, fuel oil, and electricity), ECEC and ECEI from 1978 to 2010. The grey correlation coefficients show that negative behavior of energy consumption has the closer influence on the ecosystem than positive behavior of environmental protection. Electricity is the most significant factor of the energy consumption and the highest sensitive indicator to the environmental capital input-output. From the perspective of government policy, "energy saving" is more efficient than "emission reduction". Reducing the negative activities is imminent in the current process of development. © 2013 Elsevier Ltd.

Yan Y.,Shaoxing University | Zhao H.,Tongji University
Journal of Physics Condensed Matter | Year: 2012

We investigate quantum heat transport in a one-dimensional harmonic system with random couplings. In the presence of randomness, phonon modes may normally be classified as ballistic, diffusive or localized. We show that these modes can roughly be characterized by the local nearest-neighbor level spacing distribution, similarly to their electronic counterparts. We also show that the thermal conductance G th through the system decays rapidly with the system size (G thL α). The exponent α strongly depends on the system size and can change from α<1 to α>1 with increasing system size, indicating that the system undergoes a transition from a heat conductor to a heat insulator. This result could be useful in thermal control of low-dimensional systems. © 2012 IOP Publishing Ltd.

Song Y.,Tongji University | Zou X.,University of Western Ontario
Nonlinear Dynamics | Year: 2014

In this paper, a ratio-dependent predator–prey model with diffusion is considered. The stability of the positive constant equilibrium, Turing instability, and the existence of Hopf and steady state bifurcations are studied. Necessary and sufficient conditions for the stability of the positive constant equilibrium are explicitly obtained. Spatially heterogeneous steady states with different spatial patterns are determined. By calculating the normal form on the center manifold, the formulas determining the direction and the stability of Hopf bifurcations are explicitly derived. For the steady state bifurcation, the normal form shows the possibility of pitchfork bifurcation and can be used to determine the stability of spatially inhomogeneous steady states. Some numerical simulations are carried out to illustrate and expand our theoretical results, in which, both spatially homogeneous and heterogeneous periodic solutions are observed. The numerical simulations also show the coexistence of two spatially inhomogeneous steady states, confirming the theoretical prediction. © 2014, Springer Science+Business Media Dordrecht.

Hu Y.,Tongji University
The journal of headache and pain | Year: 2013

Randomized clinical trials (RCT) assessing the efficacy and tolerability of triptans compared with placebo as short-term prophylaxis of menstrual migraine (MM) were systematically reviewed in this study. Triptans, which interfere with the pathogenesis of migraine and are effective in relieving associated neurovegetative symptoms, have been extensively proposed for prevention of menstrual migraine attacks. We searched Cochrane CENTRAL, MEDLINE and EMBASE for randomized, double-blind, placebo-controlled trials on triptans for MM until 1 Oct, 2012. A total of six RCTs were identified. Two authors independently assessed trial's quality and extracted data. Numbers of participants free from MM per perimenstrual period (PMP), requiring rescue medication, suffering from headache-associated symptoms and experiencing adverse events in treatment and control groups were used to calculate relative risk (RR) and number needed to treat (NNT) with their corresponding 95% confidence interval (CI). A total of 633 participants received frovatriptan 2.5 mg QD, 584 received frovatriptan 2.5 mg BID, 392 received naratriptan 1 mg BID, 70 received naratriptan 2.5 mg BID, 80 received zolmitriptan 2.5 mg BID, 83 received zolmitriptan 2.5 mg TID and 1104 received placebo. Overall, triptans is an effective, short-term, prophylactic treatment of choice for MM. Considering MM frequency, severity and adverse events, frovatriptan 2.5 mg BID and zolmitriptan 2.5 mg TID tend to be the preferred regimens.

Yang D.,Tongji University | Ye S.,East China Normal University | Ge J.,East China Normal University
Journal of the American Chemical Society | Year: 2013

Solvent wrapped "metastable" crystalline colloidal arrays (CCAs) have been prepared by supersaturation induced precipitation and self-assembly of monodisperse particles in polar/nonpolar organic solvents. These metastable CCAs possess ordered structures but with less stability comparing with traditionally fixed colloidal crystal systems. They are stabilized by the balance between long-range attraction and electrostatic repulsion of neighboring like-charged particles. Monitoring the reflection intensity during evaporation suggests that these crystals can exist for several hours at 90 C and even longer at room temperature. Based on the evolution of particle volume fraction in whole suspension (φSiO2), crystal phase (φcrystal) , and liquid phase (φliquid), the formation of metastable CCAs can be understood as a microscopic phase separation process, where the homogeneous dispersion will separate into a "crystal phase" with orderly stacked particles and a "liquid phase" with randomly dispersed particles. Further calculation of the volume fraction of crystal phase (V crystal/Vtotal) and the ratio of particles in crystal phase (fcrystal) shows that with the increase of designed ΦSiO2, more particles precipitate to form colloidal crystals with larger sizes but the lattice spacing of the microcrystals remains constant. Unlike fixed or traditional responsive CCAs, these metastable CCAs can reversibly assemble and disassemble with great ease, because little energy is involved or required in this transformation. Therefore, they can sense weak external disturbances, including subtle motion and slight friction or shearing forces. © 2013 American Chemical Society.

Stochastic models are important in global navigation satellite systems (GNSS) estimation problems. One can achieve reliable ambiguity resolution and precise positioning only by use of a suitable stochastic model. The BeiDou system has received increased research focus, but based only on empirical stochastic models from the knowledge of GPS. In this paper, we will systematically study the estimation, assessment and impacts of a triple-frequency BeiDou stochastic model. In our estimation problem, a single-difference, geometry-free functional model is used to extract pure random noise. A very sophisticated structure of unknown variance matrix is designed to allow the estimation of satellite-specific variances, cross correlations between two arbitrary frequencies, as well as the time correlations for phase and code observations per frequency. In assessing the stochastic models, six data sets with four brands of BeiDou receivers on short and zero-length baselines are processed, and the results are compared. In impact analysis of stochastic model, the performance of integer ambiguity resolution and positioning are numerically demonstrated using a realistic stochastic model. The results from ultrashort (shorter than 10 m) and zero-length baselines indicate that BeiDou stochastic models are affected by both observation and receiver brands. The observation variances have been modeled by an elevation-dependent function, but the modeling errors for geostationary earth orbit (GEO) satellites are larger than for inclined geosynchronous satellite orbit (IGSO) and medium earth orbit (MEO) satellites. The stochastic model is governed by both the internal errors of the receiver and external errors at the site. Different receivers have different capabilities for resisting external errors. A realistic stochastic model is very important for achieving ambiguity resolution with a high success rate and small false alarm and for determining realistic variances for position estimates. To the best of our knowledge, this paper is the first comprehensive study on such stochastic models used specifically with BeiDou data. © 2016 Springer-Verlag Berlin Heidelberg

Li J.,Nanjing University | Tang O.,Linkoping University | Tang O.,Tongji University
International Journal of Production Economics | Year: 2012

We analyze consumers choice and overflow behavior between two potential market segments with different fares, capacity allocated, and then develop the optimal capacity and pricing polices assuming that such consumers strategic behavior can be observed. Every consumer prefers to choose a fare to obtain their utmost value surplus, and select the second if the first-best choice cannot be satisfied. Our study indicates that the effort of fencing the segments should be considered to cope properly with pricing and capacity decisions in order to direct the overflows. Disregarding overflows could create differences in decisions as well as economic consequences. The study results can be implemented, but not limited, to understand the flight seat allocation problem with strategic consumers. © 2012 Elsevier B.V. All rights reserved.

Thiosemicarbazide-grafted multi-walled carbon nanotubes were prepared and employed to investigate the pre-concentration of Cd(II), Cu(II) and Pb(II) from aqueous solution prior to their determination by ICP-OES. The resulting material was characterized by FT-IR, TGA and SEM. Various factors influencing the separation and pre-concentration were investigated. The enrichment factor typically is 60. Under optimized experimental conditions, the maximum adsorption capacities of Cd(II), Cu(II) and Pb(II) were found to be 1.98, 10.94, 3.69 mg/g, and the relative standard deviations are < 3.5% (. n = 6). The new adsorbent shows superior reusability and stability. The procedure was successfully applied to the determination of trace quantities of Cd(II), Cu(II) and Pb(II) in water samples. © 2013.

Zhuang S.,Tongji University | Zhuang S.,Brown University
Cellular Signalling | Year: 2013

Signal transducers and activators of transcription (STAT) belong to a family of latent cytoplasmic factors that can be activated by tyrosine phosphorylation by the members of the Jak tyrosine kinase family in response to a variety of cytokines and growth factors. Activated STATs form dimers and translocate into nucleus to induce expression of critical genes essential for normal cellular events. In the past several years, significant progress has been made in the characterization of STAT acetylation, which is dependent on the balance between histone deacetylases (HDACs) and histone acetyltransferases (HATs) such as CBP/p300. Acetylation of STAT1, STAT2, STAT3, STAT5b and STAT6 has been identified. This review will highlight acetylation on the modulation of STAT activation. © 2013 Elsevier Inc.

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) was reported to be useful for diagnosis of tuberculosis (TB) lymphadenitis, although its indication remains unclear for suspicious pulmonary TB patients. To clarify the role of EBUS-TBNA for the diagnosis of immunocompetent TB patients with intrathoracic lymphadenopathy, we compared two diagnostic modalities: traditional bronchoscopy alone and EBUS-TBNA combined with bronchoscopy. We retrospectively studied 175 patients of suspicious pulmonary TB with intrathoracic lymphadenopathy in a single institute (Tongji University, Shanghai, China) from January 2010 to May 2011. Ninety-seven patients underwent traditional bronchoscopy alone while 78 received the combined diagnostic techniques. Sensitivity and specificity were 18.1% and 100%, respectively, in the bronchoscopy group alone, and 80% and 92.3%, respectively, in the EBUS-TBNA combination group (absolute increase in sensitivity, 61.9%; P<0.001; 95% CI, 48.7-75.1%). In the combination group, EBUS-TBNA alone was diagnostic of TB in 42 patients (64.6%, 95% CI, 53-76.2%). Bleeding without hemodynamic instability developed in two patients during the procedure of EBUS-TBNA and no hospitalization prolongation happened in the both arms. Combination of EBUS-TBNA with standard bronchoscopic technique is safe and significantly increases the diagnostic yield in patients of suspicious pulmonary TB with lymphadenopathy.

An inertance tube pulse tube refrigerator with a step piston compressor is a reversible refrigerator which means that it can be operated as a refrigerator, a cold engine, a heat engine, and a heat pump. We call it as a pulse tube machine. In this paper, a numerical simulation is conducted on an inertance tube pulse tube machine with a step piston compressor. The result shows that the pulse tube machine can work as a refrigerator, a cold engine, a heat engine, and a heat pump, depending on the swept volume ratio of the step piston compressor. © 2016 Elsevier Ltd.

Multi-targeted tyrosine kinase inhibitors (TKIs) have played an increasingly important role in the treatment of non-small cell lung cancer (NSCLC). Many recently published phase III trials have shown bittersweet efficacies of these drugs. How to optimize the efficacies of TKIs has been a hot topic in the era of individualized therapy. In this article, we review the up-to-dated advances in research on the application of TKIs for NSCLC treatment. © Translational lung cancer research.

Jia X.,Tongji University
Applied Immunohistochemistry and Molecular Morphology | Year: 2016

Synchronous double primary lung cancer (SDPLC) is detected more frequently than in the past. However, the genetic features, diagnosis, and outcome are not well known. For diagnostic and management applications, we collected 110 lesions from 55 patients who underwent surgical resection to analyze the 5 known driver mutations (EGFR, KRAS, BRAF, EML4-ALK, and ROS1) and programmed cell death ligand 1 (PD-L1) expression in various histologic types of SDPLC. Among 110 tumor lesions, 55 (50%) tumors were found harboring EGFR mutations. In addition, there were 5 (4.55%) tumors harboring EML4-ALK fusions, and 9 (8.18%) KRAS mutations. Only 1 tumor had the coexistence of L858R mutation and EML4-ALK fusion. No BRAF or ROS1 aberrations could be detected. Combining the results for the mutation and fusion patterns, 4 (7.27%) and 47 (85.5%) patients were assessed as having the same clonality and different clonality, respectively. Strikingly, patients with EGFR mutations classified as having same clonality were commonly observed among patients aged above 65 years old (P=0.021). The frequency of PD-L1 expression was 14.54% (16/110). PD-L1 had higher positive results in male, in squamous cell carcinoma subtype, and in tumors >3 cm in diameter. Univariable analysis revealed that lymph node metastasis, smoking history, and male predict worse replase-free survival and overall survival. EGFR/KRAS mutation and EML4-ALK fusion status evaluation was an important tool to support the diagnosis of SDPLC. Following resection, these marks could be used to guide targeted treatment decisions. Copyright 2016 Wolters Kluwer Health, Inc. All rights reserved.

Cheng J.,Tongji University
Journal of Constructional Steel Research | Year: 2010

The design of steel truss arch bridges is formulated as an optimization problem. The objective function considered is the weight of the steel truss arch bridge. The objective function is minimized subjected to the design constraints of strength (stress) and serviceability (deflection). An efficient, accurate, and robust algorithm is proposed for optimal design of steel truss arch bridges. The proposed algorithm integrates the concepts of the genetic algorithm (GA) and the finite element method. A real-coded/integercoded method is used to realistically represent the values of the design variables. Three GA operators consisting of constraint aggregate selection procedure, arithmetic crossover, and non-uniform mutation are proposed. Finite element method is used to compute values of implicit objective functions. A numerical example involving a detailed computational model of a long span steel truss arch bridge with a main span of 552 m is presented to demonstrate the applicability and merits of the proposed method. © 2010 Elsevier Ltd. All rights reserved.

Xue W.,Tongji University
PCI Journal | Year: 2010

This paper presents the results of experimental investigations on four full-scale precast concrete connections and a half-scale, two-story, two-bay, precast concrete, moment-resisting frame, which consisted of composite concrete beams and cast-in-place concrete columns, under cyclic loading. The precast concrete connections investigated in this paper included an exterior connection, an interior connection, a T connection, and a knee connection. Test results revealed that the four precast concrete connections, as expected, exhibited a strong column-weak beam failure mechanism and failed due to concrete crushing and fracturing of longitudinal bars as a result of forming a plastic hinge at the fixed end of the beam. The four connections behaved in a ductile manner. However, the displacement ductility of the knee connection was the poorest among them. The precast concrete frame exhibited a mixed side-sway mechanism and behaved in a ductile manner. The hysteresis curves of the frame were full and exhibited good energy-dissipation capacity. The global and interstory displacement ductility of the frame was not less than 4.5. In general, the seismic behavior of the precast concrete frame was satisfactory. This research could provide structural engineers with useful information about the safety of precast concrete-frame structures.

Zou Y.,University of Western Ontario | Zou Y.,Nanjing University of Posts and Telecommunications | Wang X.,University of Western Ontario | Shen W.,Tongji University | Shen W.,National Research Council Canada
IEEE Journal on Selected Areas in Communications | Year: 2013

In this paper, we explore the physical-layer security in cooperative wireless networks with multiple relays where both amplify-and-forward (AF) and decode-and-forward (DF) protocols are considered. We propose the AF and DF based optimal relay selection (i.e., AFbORS and DFbORS) schemes to improve the wireless security against eavesdropping attack. For the purpose of comparison, we examine the traditional AFbORS and DFbORS schemes, denoted by T-AFbORS and T-DFbORS, respectively. We also investigate a so-called multiple relay combining (MRC) framework and present the traditional AF and DF based MRC schemes, called T-AFbMRC and T-DFbMRC, where multiple relays participate in forwarding the source signal to destination which then combines its received signals from the multiple relays. We derive closed-form intercept probability expressions of the proposed AFbORS and DFbORS (i.e., P-AFbORS and P-DFbORS) as well as the T-AFbORS, T-DFbORS, T-AFbMRC and T-DFbMRC schemes in the presence of eavesdropping attack. We further conduct an asymptotic intercept probability analysis to evaluate the diversity order performance of relay selection schemes and show that no matter which relaying protocol is considered (i.e., AF and DF), the traditional and proposed optimal relay selection approaches both achieve the diversity order M where M represents the number of relays. In addition, numerical results show that for both AF and DF protocols, the intercept probability performance of proposed optimal relay selection is strictly better than that of the traditional relay selection and multiple relay combining methods. © 2013 IEEE.

Liu H.-C.,Tokyo Institute of Technology | Liu L.,Tongji University | Liu N.,Chongqing Jiaotong University | Mao L.-X.,Nanjing University
Expert Systems with Applications | Year: 2012

Failure mode and effects analysis (FMEA) is a widely used risk assessment tool for defining, identifying, and eliminating potential failures or problems in products, process, designs, and services. In traditional FMEA, the risk priorities of failure modes are determined by using risk priority numbers (RPNs), which can be obtained by multiplying the scores of risk factors like occurrence (O), severity (S), and detection (D). However, the crisp RPN method has been criticized to have several deficiencies. In this paper, linguistic variables, expressed in trapezoidal or triangular fuzzy numbers, are used to assess the ratings and weights for the risk factors O, S, and D. For selecting the most serious failure modes, the extended VIKOR method is used to determine risk priorities of the failure modes that have been identified. As a result, a fuzzy FMEA based on fuzzy set theory and VIKOR method is proposed for prioritization of failure modes, specifically intended to address some limitations of the traditional FMEA. A case study, which assesses the risk of general anesthesia process, is presented to demonstrate the application of the proposed model under fuzzy environment. © 2012 Elsevier Ltd. All rights reserved.

Fu Y.Y.,Tongji University
Zhonghua xin xue guan bing za zhi | Year: 2010

To investigate the prevalence and percentage of dyslipidemia awareness among overweight and obese residents in Beijing community. Cross-sectional data of 9786 subjects from capital cholesterol education and intervention program (CCEIP) were analyzed. Participants were divided into 3 groups (Normal, overweight and obese) based on body mass index (BMI). Blood lipid levels were determined from overnight fasting plasma samples. Questionnaires were collected to estimate awareness of dyslipidemia. (1) Blood lipids levels were positively correlated with BMI (r = 0.17, 0.18, -0.26 and 0.35 between total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride and BMI, respectively, all P < 0.01). (2) Prevalence of dyslipidemia increased in proportion with increase of BMI. The age-standardized prevalence of dyslipidemia of normal, overweight and obese population was 23. 9%, 43.3% and 65.4% in men and 17.9%, 29.2% and 42.3% in women. Dyslipidemia was more frequent in obese men than obese women (65.4% vs. 42.3%, P < 0.01). However, this gender difference decreased gradually with the increase of age. Risk of hypercholesterolemia, high LDL-C, low HDL-C and hypertriglyceridemia in obese men was 1.6, 2.9, 2.4, and 2.7 folders higher than in the normal body weight men and was 1.3, 1.9, 1.7 and 2.1 folders higher in obese women than in normal body weight women. (3) Unexpectedly, the percentage of dyslipidemia awareness in overweight and obese population was not significantly higher than in the normal body weight group (P > 0.05). The prevalence of dyslipidemia was high while the percentage of dyslipidemia awareness was rather low in obese population. Aggressive intervention should be taken in obese population, especially in the young obese men, to effectively reduce dyslipidemia.

Guo F.,Virginia Polytechnic Institute and State University | Wang X.,Tongji University | Abdel-Aty M.A.,University of Central Florida
Accident Analysis and Prevention | Year: 2010

Intersections in close spatial proximity along a corridor should be considered as correlated due to interacted traffic flows as well as similar road design and environmental characteristics. It is critical to incorporate this spatial correlation for assessing the true safety impacts of risk factors. In this paper, several Bayesian models were developed to model the crash data from 170 signalized intersections in the state of Florida. The safety impacts of risk factors such as geometric design features, traffic control, and traffic flow characteristics were evaluated. The Poisson and Negative Binomial Bayesian models with non-informative priors were fitted but the focus is to incorporate spatial correlations among intersections. Two alternative models were proposed to capture this correlation: (1) a mixed effect model in which the corridor-level correlation is incorporated through a corridor-specific random effect and (2) a conditional autoregressive model in which the magnitude of correlations is determined by spatial distances among intersections. The models were compared using the Deviance Information Criterion. The results indicate that the Poisson spatial model provides the best model fitting. Analysis of the posterior distributions of model parameters indicated that the size of intersection, the traffic conditions by turning movement, and the coordination of signal phase have significant impacts on intersection safety. © 2009 Elsevier Ltd. All rights reserved.

Shang Y.,Tongji University
Physica A: Statistical Mechanics and its Applications | Year: 2016

How complex a network is crucially impacts its function and performance. In many modern applications, the networks involved have a growth property and sparse structures, which pose challenges to physicists and applied mathematicians. In this paper, we introduce the forest likelihood as a plausible measure to gauge how difficult it is to construct a forest in a non-preferential attachment way. Based on the notions of admittable labeling and path construction, we propose algorithms for computing the forest likelihood of a given forest. Concrete examples as well as the distributions of forest likelihoods for all forests with some fixed numbers of nodes are presented. Moreover, we illustrate the ideas on real-life networks, including a benzenoid tree, a mathematical family tree, and a peer-to-peer network. © 2016 Elsevier B.V. All rights reserved.

Wu H.,Tongji University
Journal of Materials Processing Technology | Year: 2012

The cold expansion method is an effective method widely used for retarding the initiation of the fatigue crack. In the present work, the finite element analysis is performed to determine the residual stress distribution around the cold expanded hole and the ε - N method is implemented to predict the fatigue crack initiation lives. The superposition of the mean stress is used to analyze the fatigue crack initiation. It is found that the effect of K f, which decreases the K t effect, must be taken into account for the small stop-hole. Estimates of the fatigue life quantities correlate well with the experimental results. © 2012 Elsevier B.V. All rights reserved.

Shi Q.,Tongji University
International Journal of Project Management | Year: 2011

The right implementation of project management can add great value to an organization. Nevertheless, some organizations have gained little value from project management due to the fact that they have not introduced and applied project management correctly. Therefore, it is very important for an organization to enhance the soft system and the hard system synchronously in the process of implementing project management. In this paper, the author has put forward an approach named Value Adding Path Map (VAPM) which can be used to direct an organization to implement project management in the most reasonable, logical, and economical way. At last, a case has been presented to show how to apply this approach. © 2010 Elsevier B.V.

In this paper, we study the solitary wave solution and numerical simulation for the generalized Rosenau–Kawahara-RLW equation with generalized Novikov type nonlinear perturbation, which is an extension of our recent work He and Pan (Appl Math Comput 271:323–336, 2015), He (Nonlinear Dyn 82:1177–1190, 2015). We first derive the exact solitary wave solution for the newly proposed perturbed Rosenau–Kawahara-RLW equation with power law nonlinearity and then develop a three-level linearly implicit difference scheme for solving the equation. We prove that the proposed scheme is energy-conserved, unconditionally stable and second-order convergent both in time and space variables. Finally, numerical experiments are carried out to confirm the energy conservation, the convergence rates of the scheme and effectiveness for long-time simulation. © 2016 Springer Science+Business Media Dordrecht

OBJECTIVE—: α7 nicotinic acetylcholine receptor (α7nAChR) is a subtype of nAChR and has been reported to be involved in hypertension end-organ damage. In this study, we tested the role of α7nAChR in angiotensin II (Ang II)–induced senescence of vascular smooth muscle cells (VSMCs). APPROACH AND RESULTS—: Expression of α7nAChR was not influenced by Ang II. Ang II induced remarkable senescent phenotypes in rodent and human VSMCs, including increased senescence-associated β-galactosidase activity, phosphorylation of H2A.X, phosphorylation of Chk1, reduced replication, and downregulation of proliferating cell nuclear antigen. Activation of α7nAChR with a selective agonist PNU-282987 blocked Ang II–induced senescence in cultured VSMCs. Moreover, PNU-282987 treatment attenuated the Ang II infusion–induced VSMC senescence in wild-type but not in α7nAChR mice. PNU-282987 reduced the Ang II–enhanced reactive oxygen species, lipid peroxidation, and the expression of NADPH oxidase 1, NADPH oxidase 4, and p22 in cultured VSMCs isolated from wild-type but not in α7nAChR mice. Furthermore, PNU-282987 diminished Ang II–induced prosenescence signaling pathways, including p53, acetyl-p53, p21, and p16. Finally, although α7nAChR activation by PNU-282987 did not affect the Ang II–induced downregulation of SIRT1, it significantly increased intracellular NAD levels, and thereby enhanced SIRT1 activity in an AMP-dependent protein kinase–independent manner. Depletion of SIRT1 by knockdown or SIRT1 inhibitor EX527 abrogated the antisenescence effect of α7nAChR against Ang II. CONCLUSIONS—: Our results demonstrate that activation of α7nAChR alleviates Ang II–induced VSMC senescence through promoting NAD–SIRT1 pathway, suggesting that α7nAChR may be a potential therapeutic target for the treatment of Ang II–associated vascular aging disorders. © 2016 American Heart Association, Inc.

Mao S.,University of Wisconsin - Milwaukee | Lu G.,University of Wisconsin - Milwaukee | Yu K.,University of Wisconsin - Milwaukee | Bo Z.,University of Wisconsin - Milwaukee | And 2 more authors.
Advanced Materials | Year: 2010

(Figure Presented) A highly sensitive and selective fieldeffect transistor biosensor using thermally reduced graphene oxide (TRCO) sheet decorated with gold nanoparticle-antibody conjugates is demonstrated. Probe antibody (anti-Immunoglobulin G) is labeled on the surface of the TRCO sheet through gold nanoparticles and electrical detection of the protein binding (Immunoglobulin C and anti-lmmunoglobulin G) is accomplished by FET and dc measurements. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ge J.,University of California at Riverside | Ge J.,Tongji University | Yin Y.,University of California at Riverside
Angewandte Chemie - International Edition | Year: 2011

This Review summarizes recent developments in the field of responsive photonic crystal structures, including principles for design and fabrication and many strategies for applications, for example as optical switches or chemical and biological sensors. A number of fabrication methods are now available to realize responsive photonic structures, the majority of which rely on self-assembly processes to achieve ordering. Compared with microfabrication techniques, self-assembly approaches have lower processing costs and higher production efficiency, however, major efforts are still needed to further develop such approaches. In fact, some emerging techniques such as spin coating, magnetic assembly, and flow-induced self-assembly have already shown great promise in overcoming current challenges. When designing new systems with improved performance, it is always helpful to bear in mind the lessons learnt from natural photonic structures. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Zhang Z.G.,Tongji University
European review for medical and pharmacological sciences | Year: 2013

Heart failure is a major public health problem worldwide. However, the molecular mechanism is still unclear. This study aims to discover differentially expressed genes (DEGs) between non-ischemic or ischemic heart failure samples and healthy control, which may be used for diagnosis and treatment of heart failure. Gene expression profile GSE9128 was downloaded from Gene Expression Omnibus, including 3 normal samples, 4 non-ischemic heart failure samples and 4 ischemic samples. Data processing and differential analysis were carried out with packages of R. Cluster analysis was also performed for all the samples to globally observe the difference among the three groups of samples. Interactors of the DEGs were retrieved with Osprey and then networks were constructed. The overlapping part of the network was selected out using Cytoscape, for which functional enrichment analysis was applied with DAVID tools. A total of 293 and 133 DEGs were obtained for non-ischemic and ischemic heart failure, respectively. Two networks were established and then functional enrichment analysis revealed that "regulation of programmed cell death" was most significantly over-represented in common DEGs. Genes differentially expressed in non-ischemic and ischemic heart failure can be biomarkers to distinguish the two types of heart failure. Besides, these genes can be targets to develop treatments.

Yin F.,Tongji University
European review for medical and pharmacological sciences | Year: 2013

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic synovitis that progresses to destruction of cartilage and bone. The purpose of this study was to employ microarray analysis combined with bioinformatics techniques to evaluate differential gene expression in BM-derived mononuclear cells obtained from patients with rheumatoid arthritis (RA) or osteoarthritis (OA) to study the pathogenesis of this disease. Gene expression profiles in BM-derived mononuclear cells from 9 RA and 10 OA patients were obtained from GEO. The bone marrow (BM) mononuclear cells showed 2581 up-regulated and 649 down-regulated genes in RA patients relative to the OA group: Our analysis indicated that several differentially expressed genes might play crucial roles in RA development, including SP1, RARA, ETS1, ETS2, FOS and ESR1. Further analysis predicted these genes might be involved in RA through cancer related pathways and immunity related pathways. Furthermore, these genes may serve as novel therapeutic targets for the treatment of RA.

Sun B.,Tongji University | Ma W.,Lanzhou Jiaotong University
Artificial Intelligence Review | Year: 2014

Recently, the theory and applications of soft set has brought the attention by many scholars in various areas. Especially, the researches of the theory for combining the soft set with the other mathematical theory have been developed by many authors. In this paper, we propose a new concept of soft fuzzy rough set by combining the fuzzy soft set with the traditional fuzzy rough set. The soft fuzzy rough lower and upper approximation operators of any fuzzy subset in the parameter set were defined by the concept of the pseudo fuzzy binary relation (or pseudo fuzzy soft set) established in this paper. Meanwhile, several deformations of the soft fuzzy rough lower and upper approximations are also presented. Furthermore, we also discuss some basic properties of the approximation operators in detail. Subsequently, we give an approach to decision making problem based on soft fuzzy rough set model by analyzing the limitations and advantages in the existing literatures. The decision steps and the algorithm of the decision method were also given. The proposed approach can obtain a object decision result with the data information owned by the decision problem only. Finally, the validity of the decision methods is tested by an applied example.©Springer Science+Business Media B.V. 2011.

Wang Z.-B.,University of Connecticut Health Center | Zhang X.,Tongji University | Li X.-J.,University of Connecticut Health Center
Cell Research | Year: 2013

Establishing human cell models of spinal muscular atrophy (SMA) to mimic motor neuron-specific phenotypes holds the key to understanding the pathogenesis of this devastating disease. Here, we developed a closely representative cell model of SMA by knocking down the disease-determining gene, survival motor neuron (SMN), in human embryonic stem cells (hESCs). Our study with this cell model demonstrated that knocking down of SMN does not interfere with neural induction or the initial specification of spinal motor neurons. Notably, the axonal outgrowth of spinal motor neurons was significantly impaired and these disease-mimicking neurons subsequently degenerated. Furthermore, these disease phenotypes were caused by SMN-full length (SMN-FL) but not SMN-Δ7 (lacking exon 7) knockdown, and were specific to spinal motor neurons. Restoring the expression of SMN-FL completely ameliorated all of the disease phenotypes, including specific axonal defects and motor neuron loss. Finally, knockdown of SMN-FL led to excessive mitochondrial oxidative stress in human motor neuron progenitors. The involvement of oxidative stress in the degeneration of spinal motor neurons in the SMA cell model was further confirmed by the administration of N-acetylcysteine, a potent antioxidant, which prevented disease-related apoptosis and subsequent motor neuron death. Thus, we report here the successful establishment of an hESC-based SMA model, which exhibits disease gene isoform specificity, cell type specificity, and phenotype reversibility. Our model provides a unique paradigm for studying how motor neurons specifically degenerate and highlights the potential importance of antioxidants for the treatment of SMA. © 2013 IBCB, SIBS, CAS All rights reserved.

Ge Y.-J.,Tongji University
Gongcheng Lixue/Engineering Mechanics | Year: 2011

With the rapid development of long span bridges in China in past three decades, this paper presented technical challenges of wind resistance on three type long-span bridges, including flutter instability and control of suspension bridges, wind induced vibration of cable stayed bridges and control of wind-rain induced cable vibration, vortex induced vibration and control of arch bridges, and the refinements on aerodynamic flutter and buffeting of super long span bridges. It can be concluded that the intrinsic limit of a span length due to aerodynamic stability is about 1, 500m for suspension bridges, and beyond or even approaching this limit, designers should be prepared to improve its aerodynamic stability. The cable-stayed bridges with a main span over 1000m have high enough critical flutter speed, but the main aerodynamic concern is the rain-wind induced vibration of long stay cables. Except one example of vortex-induced vibration, long-span arch bridges have no wind resistance problem. The refinement research on wind resistance of long-span bridges was also introduced with a full-mode flutter analysis method, the bridge buffeting frequency-domain analysis under skew wind action, the bridge flutter and buffeting reliability evaluation method based on second order theory and first passage theory, and the unveiling of a bridge flutter evolution process, generation mechanism and control law.

Zhang Z.,Tongji University | Huang H.,University of Utah | Yang X.,University of Utah | Zang L.,University of Utah
Journal of Physical Chemistry Letters | Year: 2011

Intrinsic graphene is a semimetal or zero bandgap semiconductor, which hinders its applications for nanoelectronics. To develop high-performance nanodevices with graphene, it is necessary to open the bandgap and precisely control the charge carrier type and density. In this perspective, we focus on tailoring the electronic properties of graphene by noncovalent stacking with aromatic molecules through π-π interaction. Different types of molecules (functioning as either an electron donor or acceptor when stacked with graphene) as reported in recent literature are presented regarding surface patterning, bandgap engineering, surface doping, as well as applications in nanodevices, particularly the field-effect transistors (FETs). On the basis of the current progress along this research line, future issues and challenges are also briefly discussed. © 2011 American Chemical Society.

Denisov S.,Sumy State University | Denisov S.,University of Augsburg | Denisov S.,Nizhny Novgorod State Technical University | Flach S.,Massey University | And 2 more authors.
Physics Reports | Year: 2014

Transport properties of particles and waves in spatially periodic structures that are driven by external time-dependent forces manifestly depend on the space-time symmetries of the corresponding equations of motion. A systematic analysis of these symmetries uncovers the conditions necessary for obtaining directed transport. In this work we give a unified introduction into the symmetry analysis and demonstrate its action on the motion in one-dimensional periodic, both in time and space, potentials. We further generalize the analysis to quasi-periodic drives, higher space dimensions, and quantum dynamics. Recent experimental results on the transport of cold and ultracold atomic ensembles in ac-driven optical potentials are reviewed as illustrations of theoretical considerations. © 2014 Elsevier B.V.

Huang M.,Tongji University
SAE International Journal of Passenger Cars - Mechanical Systems | Year: 2014

A 2 DOF nonlinear dynamic model of the automotive wiper system is established. Complex eigenvalues are calculated based on the complex modal theory, and the system stability as well as its dependence on wiping velocity is analyzed. Bifurcation characteristics of frictional self-excited vibration and stick-slip vibration relative to wiping velocity are studied through numerical analysis. Research of nonlinear vibration characteristics under various wiping velocities is conducted by means of phase trajectories, Poincarȳ map and frequency spectrum. The pervasive stick-slip vibration during wiping is confirmed, and its temporal and spatial distributions are analyzed by way of time history and contour map. Duty ratio of stick vibration and statistics of scraping residual are introduced as quantitative indexes for wiping effect evaluation. Results indicate that the negative slop of frictional-velocity characteristic is the root cause of system instability. As the wiping velocity decreases, the vibration state transforms from periodic to quasi-periodic and then to chaos in both high and low velocity ranges. The wiping process is accompanied with prominent stick-slip vibration except when the nominal wiping velocity exceeds 0.725m/s. To increase the wiping velocity can improve system stability, restrain stick-slip vibration and reduce adverse impacts on wiping effect caused by the uneven distribution of scrapings. © 2014 SAE International.

Central precocious puberty (CPP) is a common pediatric endocrine disease caused by early activation of hypothalamic-putuitary-gonadal (HPG) axis, yet the exact mechanism was poorly understood. Although there were some proofs that an altered metabolic profile was involved in CPP, interpreting the biological implications at a systematic level is still in pressing need. To gain a systematic understanding of the biological implications, this paper analyzed the CPP differential urine metabolites from a network point of view. In this study, differential urine metabolites between CPP girls and age-matched normal ones were identified by LC-MS. Their basic topological parameters were calculated in the background network. The network decomposition suggested that CPP differential urine metabolites were most relevant to amino acid metabolism. Further proximity analysis of CPP differential urine metabolites and neuro-endocrine metabolites showed a close relationship between CPP metabolism and neuro-endocrine system. Then the core metabolic network of CPP was successfully constructed among all these differential urine metabolites. As can be demonstrated in the core network, abnormal aromatic amino acid metabolism might influence the activity of HPG and hypothalamic pituitary adrenal (HPA) axis. Several adjustments to the early activation of puberty in CPP girls could also be revealed by urine metabonomics. The present article demonstrated the ability of urine metabonomics to provide several potential metabolic clues for CPP's mechanism. It was revealed that abnormal metabolism of amino acid, especially aromatic amino acid, might have a close correlation with CPP's pathogenesis by activating HPG axis and suppressing HPA axis. Such a method of network-based analysis could also be applied to other metabonomics analysis to provide an overall perspective at a systematic level.

In this paper, the robust exponential stability of uncertain impulsive neural networks with time-varying delays and delayed impulses is considered. It is assumed that the considered impulsive neural networks have norm-bounded parametric uncertainties and time-varying delays and the state variables on the impulses may relate to the time-varying delays. By using Lyapunov functions together with Razumikhin technique or with differential inequalities, some new robust exponential stability criteria are provided. Some examples and their simulations, including examples that the stability of which can not be tackled by the existing results, are also presented to illustrate the effectiveness and the advantage of the obtained results. © 2011 Elsevier B.V.

Du Z.,Tongji University
International Journal of Quantum Chemistry | Year: 2012

The Wiener index of a connected graph is defined as the sum of distances between all unordered pairs of its vertices. It has found various applications in chemical research. We determine the minimum and the maximum Wiener indices of trees with given bipartition and the minimum Wiener index of monocyclic graphs with given bipartition, respectively. We also characterize the graphs whose Wiener indices attain these values. © 2011 Wiley Periodicals, Inc.

An unnoticed chaotic firing pattern, lying between period-1 and period-2 firing patterns, has received little attention over the past 20 years since it was first simulated in the Hindmarsh-Rose (HR) model. In the present study, the rat sciatic nerve model of chronic constriction injury (CCI) was used as an experimental neural pacemaker to investigate the transition regularities of spontaneous firing patterns. Chaotic firing lying between period-1 and period-2 firings was observed located in four bifurcation scenarios in different, isolated neural pacemakers. These bifurcation scenarios were induced by decreasing extracellular calcium concentrations. The behaviors after period-2 firing pattern in the four scenarios were period-doubling bifurcation not to chaos, period-doubling bifurcation to chaos, period-adding sequences with chaotic firings, and period-adding sequences with stochastic firings. The deterministic structure of the chaotic firing pattern was identified by the first return map of interspike intervals and a short-term prediction using nonlinear prediction. The experimental observations closely match those simulated in a two-dimensional parameter space using the HR model, providing strong evidences of the existence of chaotic firing lying between period-1 and period-2 firing patterns in the actual nervous system. The results also present relationships in the parameter space between this chaotic firing and other firing patterns, such as the chaotic firings that appear after period-2 firing pattern located within the well-known combshaped region, periodic firing patterns and stochastic firing patterns, as predicted by the HR model. We hope that this study can focus attention on and help to further the understanding of the unnoticed chaotic neural firing pattern. © 2013 Huaguang Gu.

Li X.,Tongji University | Baki M.F.,University of Windsor | Aneja Y.P.,University of Windsor
Computers and Operations Research | Year: 2010

In this paper we propose an ant colony optimization metaheuristic (ACO-CF) to solve the machinepart cell formation problem. ACO-CF is a MAXMIN ant system, which is implemented in the hyper-cube framework to automatically scale the objective functions of machinepart cell formation problems. As an intensification strategy, we integrate an iteratively local search into ACO-CF. Based on the assignment of the machines or parts, the local search can optimally reassign parts or machines to cells. We carry out a series of experiments to investigate the performance of ACO-CF on some standard benchmark problems. The comparison study between ACO-CF and other methods proposed in the literature indicates that ACO-CF is one of the best approaches for solving the machinepart cell formation problem. © 2010 Elsevier Ltd. All rights reserved.

Karuturi S.K.,Nanyang Technological University | Luo J.,Nanyang Technological University | Cheng C.,Nanyang Technological University | Cheng C.,Tongji University | And 4 more authors.
Advanced Materials | Year: 2012

A 3D hierarchically ordered nanobush structure is fabricated for use as a photoanode in photoelectrochemical cells. The photoanode structure has several favorable intrinsic characteristics, including high interface area, direct electron transport pathways, and engineered light scattering centers. Sensitization with CdS quantum dots is demonstrated, and this nanobush photoanode is expected to be advantageous also in solar cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In this paper, we propose a second-order three-level linearly implicit finite difference method for solving the extended Fisher-Kolmogorov equation in both 1D and 2D. The existence and uniqueness of the proposed scheme is proved, the stability and convergence of numerical solution in L∞-norm are established. The proposed linear method is generally much more efficient than the existing nonlinear methods. © 2016 Elsevier Ltd.

Li X.,Tongji University | Leung S.C.H.,City University of Hong Kong | Tian P.,Shanghai JiaoTong University
Expert Systems with Applications | Year: 2012

This paper addressed the heterogeneous fixed fleet open vehicle routing problem (HFFOVRP), in which the demands of customers are fulfilled by a fleet of fixed number of vehicles with various capacities and related costs. Moreover, the vehicles start at the depot and terminate at one of the customers. This problem is an important variant of the classical vehicle routing problem and can cover more practical situations in transportation and logistics. We propose a multistart adaptive memory programming metaheuristic with modified tabu search algorithm to solve this new vehicle routing problem. The algorithmic efficiency and effectiveness are experimentally evaluated on a set of generated instances. © 2011 Elsevier Ltd. All rights reserved.

NRAGE, a neurotrophin receptor-interacting melanoma antigen-encoding gene homolog, is significantly increased in the nucleus of radioresistant esophageal tumor cell lines and is highly upregulated to promote cell proliferation in esophageal carcinomas (ECs). However, whether the overexpressed NRAGE promotes cell growth by participating in DNA-damage response (DDR) is still unclear. Here we show that NRAGE is required for efficient double-strand breaks (DSBs) repair via homologous recombination repair (HRR) and downregulation of NRAGE greatly sensitizes EC cells to DNA-damaging agents both in vitro and in vivo. Moreover, NRAGE not only regulates the stability of DDR factors, RNF8 and BARD1, in a ubiquitin-proteolytic pathway, but also chaperons the interaction between BARD1 and RNF8 via their RING domains to form a novel ternary complex. Additionally, the expression of NRAGE is closely correlated with RNF8 and BARD1 in esophageal tumor tissues. In summary, our findings reveal a novel function of NRAGE that will help to guide personalized esophageal cancer treatments by targeting NRAGE to increase cell sensitivity to DNA-damaging therapeutics in the long run.Cell Death and Differentiation advance online publication, 1 April 2016; doi:10.1038/cdd.2016.29. © 2016 Macmillan Publishers Limited

In this paper, stochastic stability for a class of discrete-time Markovian jump delay systems with delayed impulses and partly unknown transition probabilities is investigated. Some new results are given based on stochastic Lyapunov functionals. It is shown that an unstable discrete-time Markovian jump delay system can be stochastically stable under certain stabilizing impulses. It is also shown that, when the nearest impulsive time interval is appropriately large, a stable discrete-time Markovian jump delay system can retain its stochastic stability property even with destabilizing impulses. Numerical examples together with their simulations are provided to demonstrate the effectiveness of the derived results. © 2013 Springer Science+Business Media Dordrecht.

Nie G.J.,Tongji University | Nie G.J.,Virginia Polytechnic Institute and State University | Batra R.C.,Virginia Polytechnic Institute and State University
Journal of Elasticity | Year: 2010

We employ the Airy stress function to derive analytical solutions for plane strain static deformations of a functionally graded (FG) hollow circular cylinder with Young's modulus E and Poisson's ratio v taken to be functions of the radius r. For E 1 and v 1 power law functions of r, and for E 1 an exponential but v 1 an affine function of r, we derive explicit expressions for stresses and displacements. Here E 1 and v 1 are effective Young's modulus and Poisson's ratio appearing in the stress-strain relations. It is found that when exponents of the power law variations of E 1 and v 1 are equal then stresses in the cylinder are independent of v 1; however, displacements depend upon v 1. We have investigated deformations of a FG hollow cylinder with the outer surface loaded by pressure that varies with the angular position of a point, of a thin cylinder with pressure on the inner surface varying with the angular position, and of a cut circular cylinder with equal and opposite tangential tractions applied at the cut surfaces. When v 1 varies logarithmically through-the-thickness of a hollow cylinder, then the maximum radial stress, the maximum hoop stress and the maximum radial displacements are noticeably affected by values of v 1. Conversely, we find how E 1 and v 1 ought to vary with r in order to achieve desired distributions of a linear combination of the radial and the hoop stresses. It is found that for the hoop stress to be constant in the cylinder, E 1 and v 1 must be affine functions of r. For the in-plane shear stress to be uniform through the cylinder thickness, E 1 and v 1 must be functions of r 2. Exact solutions and optimal design parameters presented herein should serve as benchmarks for comparing approximate solutions derived through numerical algorithms. © 2010 Springer Science+Business Media B.V.

Nie G.J.,Tongji University | Batra R.C.,Virginia Polytechnic Institute and State University
Composite Structures | Year: 2010

We analyze axisymmetric deformations of a rotating disk with its thickness, mass density, thermal expansion coefficient and shear modulus varying in the radial direction. The disk is made of a rubberlike material that is modeled as isotropic, linear thermoelastic and incompressible. We note that the hydrostatic pressure in the constitutive relation of the material is to be determined as a part of the solution of the problem since it cannot be determined from the strain field. The problem is analyzed by using an Airy stress function φ. The non-homogeneous ordinary differential equation with variable coefficients for φ is solved either analytically or numerically by the differential quadrature method. We have also analyzed the challenging problem of tailoring the variation of either the shear modulus or the thermal expansion coefficient in the radial direction so that a linear combination of the hoop stress and the radial stress is constant in the disk. For a rotating annular disk we present the explicit expression of the thermal expansion coefficient for the hoop stress to be uniform within the disk. For a rotating solid disk we give the exact expressions for the shear modulus and the thermal expansion coefficient as functions of the radial coordinate so as to achieve constant hoop stress. Numerical results for a few typical problems are presented to illuminate effects of material inhomogeneities on deformations of a hollow and a solid rotating disk. © 2009 Elsevier Ltd. All rights reserved.

Nie G.J.,Tongji University | Batra R.C.,Virginia Polytechnic Institute and State University
Composite Structures | Year: 2010

We use the Airy stress function to derive exact solutions for plane strain deformations of a functionally graded (FG) hollow cylinder with the inner and the outer surfaces subjected to different boundary conditions, and the cylinder composed of an isotropic and incompressible linear elastic material. For the shear modulus given by either a power law or an exponential function of the radius r, we derive explicit expressions for stresses, the hydrostatic pressure and displacements. Conversely, we find the variation with r of the shear modulus for a linear combination of the radial and the hoop stresses to have a pre-assigned variation in the cylinder; this inverse problem is usually called material tailoring. The shear modulus found while solving the inverse problem must be positive everywhere. Results for a few problems are computed and presented graphically. It seems that the Airy stress function approach is used here for the first time to analyze two-dimensional problems for incompressible materials. When studying axisymmetric deformations of an FG cylinder, it is found that for the hoop stress to be uniform through the cylinder thickness the shear modulus must be proportional to the radial coordinate r as found earlier by Batra [Batra RC. Optimal design of functionally graded incompressible linear elastic cylinders and spheres. AIAAJ 2008;46(8):2005-7.] and for the maximum in-plane shear stress to be constant the shear modulus must vary as r2. The expression for the maximum in-plane shear stress in terms of pressures and the radii of the inner and the outer surfaces of the cylinder is a universal result valid for all materials for which the shear modulus is proportional to r2. For a hollow cylinder fixed on the inner surface and subjected to tangential tractions on the outer surface (or vice versa) the through-the-thickness in-plane shear stress distribution is also universal and is determined by surface tractions and the outer radius of the cylinder; it is independent of the spatial variation of the shear modulus. © 2009 Elsevier Ltd. All rights reserved.

Cheng Y.S.,Tongji University
World journal of gastroenterology : WJG | Year: 2010

To compare the efficacy of self-expanding metallic stents (SEMSs) for the long-term clinical treatment of achalasia. Ninety achalasic patients were treated with a temporary SEMS with a diameter of 20 mm (n = 30, group A), 25 mm (n = 30, group B) or 30 mm (n = 30, group C). Data on clinical symptoms, complications and treatment outcomes were collected, and follow-up was made at 6 mo and at 1, 3-5, 5-8, 8-10 and > 10 years, postoperatively. Stent placement was successful in all patients. Although chest pain occurrence was high, stent migration was less in group C than in groups A and B. The clinical remission rate at 5-8, 8-10 and > 10 years in group C was higher than that in the other two groups. The treatment failure rate was lower in group C (13%) than in groups A (53%) and B (27%). SEMSs in group C resulted in reduced dysphagia scores and lowered esophageal sphincter pressures, as well as normal levels of barium height and width during all the follow-up time periods. Conversely, these parameters increased over time in groups A and B. The primary patency in group C was longer than in groups A and B. A temporary SEMS with a diameter of 30 mm is associated with a superior long-term clinical efficacy in the treatment of achalasia compared with a SEMS with a diameter of 20 mm or 25 mm.

Liu X.,Tongji University | Chen T.,Fudan University
IEEE Transactions on Neural Networks | Year: 2011

In this paper, we investigate the cluster synchronization problem for linearly coupled networks, which can be recurrently connected neural networks, cellular neural networks, Hodgkin-Huxley models, Lorenz chaotic oscillators, etc., by adding some simple intermittent pinning controls. We assume the nodes in the network to be identical and the coupling matrix to be asymmetric. Some sufficient conditions to guarantee global cluster synchronization are presented. Furthermore, a centralized adaptive intermittent control is introduced and theoretical analysis is provided. Then, by applying the adaptive approach on the diagonal submatrices of the asymmetric coupling matrix, we also get the corresponding cluster synchronization result. Finally, numerical simulations are given to verify the theoretical results. © 2011 IEEE.

In this letter, we propose to realize optical discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) on one single multimode interference (MMI) coupler. In comparison to the previous MMI coupler-based DFT device, this device does not require any couplers or cascaded structures. The simulation results show that it can realize the DFT/IDFT precisely. © 2010 IEEE.

Qiao J.,Shanghai JiaoTong University | Li A.,Tongji University | Jin X.,Shanghai JiaoTong University
Immunology and Cell Biology | Year: 2011

The respiratory syncytial virus (RSV) is a primary cause of lower respiratory tract infections in children, the elderly and in people who are immune suppressed, and is also the cause for the development of asthma primarily in infants. However, the immunological mechanisms by which RSV enhances allergic sensitization and asthma remain unclear. The aim of this study was to examine the influence of RSV-infected airway epithelial cells on the activation and functions of rat myeloid dendritic cells (mDCs).We found that the exposure of primary rat airway epithelial cells (PRAECs) to RSV induced a rapid (6 h), high (12 h) and persistent (18 h) increase in thymic stromal lymphopoietin (TSLP) mRNA compared with untreated PRAECs. TSLP protein expression was also enhanced by RSV infection. Functional maturation of mDCs was induced by RSV-treated PRAECs, as shown by their enhanced levels of OX40L and thymus- and activation-regulated chemokine (TARC) mRNAs, which increased the expressions of major histocompatibility complex II (MHCII) and CD86 costimulatory molecules and promoted enhanced T-cell proliferation in mixed lymphocyte reactions. These activities were inhibited in cocultures with RSV-infected RTECs (rat tracheal epithelial cells, an immortalized cell strain) that had been pretreated with TSLP-targeted small interfering RNA. These results suggest that RSV can induce epithelial cells to produce TSLP, which in turn promotes the maturation of mDCs that might support Th2 cell polarization. © 2011 Australasian Society for Immunology Inc. All rights reserved.

A new molecularly imprinted polymer (MIP) adsorbent for clofibric acid (CA) was prepared by a non-covalent protocol. Characterization of the obtained MIP was achieved by scanning electron microscopy (SEM) and nitrogen sorption. Sorption experimental results showed that the MIP had excellent binding affinity for CA and the adsorption of CA by MIP was well described by pseudo-second-order model. Scatchard plot analysis revealed that two classes of binding sites were formed in the MIP with dissociation constants of 7.52 ± 0.46 mg L(-1) and 114 ± 4.2 mg L(-1), respectively. The selectivity of MIP demonstrated higher affinity for CA over competitive compound than that of non-imprinted polymers (NIP). The MIP synthesized was used to remove CA from spiked surface water and exhibited significant binding affinity towards CA in the presence of total dissolved solids (TDS). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance.

Ding J.,Fudan University | Zhou S.,Fudan University | Guan J.,Tongji University
BMC Bioinformatics | Year: 2010

Background: MicroRNAs (simply miRNAs) are derived from larger hairpin RNA precursors and play essential regular roles in both animals and plants. A number of computational methods for miRNA genes finding have been proposed in the past decade, yet the problem is far from being tackled, especially when considering the imbalance issue of known miRNAs and unidentified miRNAs, and the pre-miRNAs with multi-loops or higher minimum free energy (MFE). This paper presents a new computational approach, miRenSVM, for finding miRNA genes. Aiming at better prediction performance, an ensemble support vector machine (SVM) classifier is established to deal with the imbalance issue, and multi-loop features are included for identifying those pre-miRNAs with multi-loops.Results: We collected a representative dataset, which contains 697 real miRNA precursors identified by experimental procedure and other computational methods, and 5428 pseudo ones from several datasets. Experiments showed that our miRenSVM achieved a 96.5% specificity and a 93.05% sensitivity on the dataset. Compared with the state-of-the-art approaches, miRenSVM obtained better prediction results. We also applied our method to predict 14 Homo sapiens pre-miRNAs and 13 Anopheles gambiae pre-miRNAs that first appeared in miRBase13.0, MiRenSVM got a 100% prediction rate. Furthermore, performance evaluation was conducted over 27 additional species in miRBase13.0, and 92.84% (4863/5238) animal pre-miRNAs were correctly identified by miRenSVM.Conclusion: MiRenSVM is an ensemble support vector machine (SVM) classification system for better detecting miRNA genes, especially those with multi-loop secondary structure. © 2010 Zhou et al; licensee BioMed Central Ltd.

Han F.,Tongji University
Journal of Convergence Information Technology | Year: 2011

Data mining promises to discover actionable patterns to users. However, patterns generated from traditional association mining that are often difficult to understand and put into action, thus cannot satisfy the needs of real world completely. Actionable patterns address that patterns are deemed actionable if the user can act upon them in her favor. Recent studies present combined association rule mining can help extract useful knowledge from learned single rules, but even in this case, there still exists some interesting rules which cannot be found out by combined association rule mining. Therefore, in order to extract further actionable pattern and perfect combined association rule mining, this study proposes a novel approach to discover actionable combined patterns with composite items.

Wu X.,Tongji University
International Journal of Digital Content Technology and its Applications | Year: 2011

Customer relationship management data mining are introduced In this paper. BP neural network is used in intelligent business-to-customer relationship evaluation. The customer relationship evaluation model is built based on the evaluation index system, which can train data samples and then obtain evaluation results. This paper also describes analysis of a customer relationship evaluation system based on neural network technology that is implemented using ASP.NET 2.0, SQL Server 2005 and MATLAB, conceptual design of the system, and implementation of the system. It is worth mentioning that the system has solved the MATLAB mixed programming problem, which promote the programming development of MATLAB application.

Ren J.,King Abdullah University of Science and Technology | Wu J.H.,Tongji University
Calcified Tissue International | Year: 2012

Estrogen regulates critical cellular functions, and its deficiency initiates bone turnover and the development of bone mass loss in menopausal females. Recent studies have demonstrated that 17β-estradiol (E 2) induces rapid non-genomic responses that activate downstream signaling molecules, thus providing a new perspective to understand the relationship between estrogen and bone metabolism. In this study, we investigated rapid estrogen responses, including calcium release and MAPK phosphorylation, in osteocyte-like MLO-Y4 cells. E 2 elevated [Ca 2+] i and increased Ca 2+ oscillation frequency in a dose-dependent manner. Immunolabeling confirmed the expression of three estrogen receptors (ERα, ERβ, and G protein-coupled receptor 30 [GPR30]) in MLO-Y4 cells and localized GPR30 predominantly to the plasma membrane. E 2 mobilized calcium from intracellular stores, and the use of selective agonist(s) for each ER showed that this was mediated mainly through the GPR30 pathway. MAPK phosphorylation increased in a biphasic manner, with peaks occurring after 7 and 60 min. GPR30 and classical ERs showed different temporal effects on MAPK phosphorylation and contributed to MAPK phosphorylation sequentially. ICI182,780 inhibited E 2 activation of MAPK at 7 min, while the GPR30 agonist G-1 and antagonist G-15 failed to affect MAPK phosphorylation levels. G-1-mediated MAPK phosphorylation at 60 min was prevented by prior depletion of calcium stores. Our data suggest that E 2 induces the non-genomic responses Ca 2+ release and MAPK phosphorylation to regulate osteocyte function and indicate that multiple receptors mediate rapid E 2 responses. © 2012 Springer Science+Business Media, LLC.

Rycaj K.,University of Texas M. D. Anderson Cancer Center | Tang D.G.,University of Texas M. D. Anderson Cancer Center | Tang D.G.,Tongji University
International Journal of Radiation Biology | Year: 2014

Purpose: Radiation therapy has made significant contributions to cancer treatment. However, despite continuous improvements, tumor recurrence and therapy resistance still occur in a high proportion of patients. One underlying reason for this radioresistance might be attributable to the presence of cancer stem cells (CSC). The purpose of this review is to discuss CSC-specific mechanisms that confer radiation resistance. Conclusions: We focus our discussions on breast cancer and glioblastoma multiforme (GBM) and conclude that both CSC-intrinsic and CSC-extrinsic factors as well as adaptive responses in CSC caused by irradiation and microenvironmental changes all make contributions to CSC-mediated radioresistance. Our discussions emphasize CSC as novel therapeutic targets in order to potentiate radiotherapy efficacy. © 2014 Informa UK, Ltd.

Yang L.,Tongji University | Li Y.,University of Shanghai for Science and Technology
Sustainable Cities and Society | Year: 2013

The establishment of low-carbon city is the key to achieving low-carbon future. Low-carbon city should give consideration to both low-carbon production and low-carbon consumption. Based on the rapid development of economy and continuous improvement of living standard, the low-carbon transformation of economical development, the consumption concept and living style is conducive to achieve the goal of low energy consumption and low carbon dioxide emission. The development of low carbon city is the need to cope with global climate change, which is also the must choice for China to guarantee sustainable development of economic society. As the second largest economy in the world, China is in the economical transition period. Actions need to be taken to speed up the development of ecology city construction according to our national condition, formulating and implementing related policy. Meanwhile, low-carbon technology and low-carbon industry should be vigorously developed to advance the green, cyclic and low-carbon development. We are striving for resource-saving and the environment-protecting industrial structure, production method and life style. To keep running in front in the third Industrial Revolution medium-distance, to complete the well-off society comprehensively and to realize the sustainable development, the reason why China has to choose the low-carbon road and the way of developing low-carbon city are analyzed in this paper. Then some specific requests to establish low-carbon city are put forward. © 2013 Elsevier B.V. All rights reserved.

Xu B.,Tongji University | Zhu Y.,University of California at Los Angeles
Transportation Research Part D: Transport and Environment | Year: 2013

To determine ways to reduce commuters' ultrafine particle exposure, factors such as ventilation condition, mechanical airflow rate, driving speed, cabin air filter quality, and cabin air filter use are examined. The results show that the in-cabin to on-roadway ratio is reduced by 20% when the fan is set to recirculation-on versus when set to recirculation-off because fewer ultrafine particles are exchanged between the inside and outside of the cabin. Also, when the fan is set to recirculation-off, the ratio is reduced by 40% at lower mechanical airflow rates. The thickest cabin air filter resulted in a 30% in-cabin to on-roadway ratio decrease compared with the thinnest. Thus, driving conditions with the least UFP in-cabin to on-roadway ratio is when a vehicle is operating with a high efficiency cabin filter, the ventilation set to fan-on and recycling is recirculation on, and at a high ventilation airflow rate. Furthermore, recirculating in-cabin air through a high efficiency particulate air filter was found to significantly reduce in-cabin UFP exposure. © 2012 Elsevier Ltd.

Mei J.,Tongji University
Zhonghua yi shi za zhi (Beijing, China : 1980) | Year: 2014

In 1858, a German surgeon named Von Langenbeck did the first internal fixation of femoral neck fracture (FNF) with metal silver screw. In 1875, a German doctor Franz K?nig did the same operation successfully with metal screws under antiseptic condition. In 1883, an American surgeon, Nicholass Senn suggested that all of the FNF should be treated by operation, but the proposition was not accepted extensively. In 1931, Smith-Petersen from the USA and his colleagues first published the report on the result of open reduction and internal fixation of FNF by the use of trifin nail. Due to the help of auxiliary appliance designed separately by the Swedish Sven Johansson (1932) and American H. Heyward Wescott (1934). In 1941, the American Academy of Orthopaedic Surgeons (AAOS) advocated the technique of trifin nail for its internal fixation. However, in 1976, the British Medical Research Council pointed out that the trifin nail was not suitable for the displaced FNF. The Asnis cannulated screws appeared in 1980, that is still in use today. In the 1940s, Chi-mao Meng and Yan-qing Ye started to treat FNF with trifin nail. In 1989, Jie Wei cured the FNF with cannulated screws produced by AO company first, which was extensively applied nationwide soon.

Yan J.,Tongji University | Li S.,University of Houston | Li S.,University of Pittsburgh
International Reviews of Immunology | Year: 2014

Despite the progress made in the clinical management of sepsis, sepsis morbidity and mortality rates remain high. The inflammatory pathogenesis and organ injury leading to death from sepsis are not fully understood for vital organs, especially the liver. Only recently has the role of the liver in sepsis begun to be revealed. Pre-existing liver dysfunction is a risk factor for the progression of infection to sepsis. Liver dysfunction after sepsis is an independent risk factor for multiple organ dysfunction and sepsis-induced death. The liver works as a lymphoid organ in response to sepsis. Acting as a double-edged sword in sepsis, the liver-mediated immune response is responsible for clearing bacteria and toxins but also causes inflammation, immunosuppression, and organ damage. Attenuating liver injury and restoring liver function lowers morbidity and mortality rates in patients with sepsis. This review summarizes the central role of liver in the host immune response to sepsis and in clinical outcomes. © 2014 Informa Healthcare USA, Inc.

Chen F.,Shanghai Institute of Technology | Zhu D.,Tongji University
Habitat International | Year: 2013

This paper addresses the background research on the low-carbon city and determines its definition, models and methods of appraisal. It carries out a quantitative and empirical analysis of carbon emissions in the process of Shanghai's development in order to seek out the conflicts of interest and the issues involved and to determine the overall strategic objectives for building, industry (production) and transportation in the future. In conclusion, the article sets development strategies for concepts in low-carbon lifestyle, recycling of materials and intensive use of urban space. © 2011 Elsevier Ltd.

Zhang W.-J.,Shanghai JiaoTong University | Zhang C.-L.,Tongji University
Energy Conversion and Management | Year: 2011

Rapid cycling the compressor is an alternative of the variable speed compressor to modulate the capacity of refrigeration systems for the purpose of energy saving at part-load conditions. The multi-evaporator air conditioner combined with the rapid cycling compressor brings difficulties in control design because of the sophisticated system physics and dynamics. In this paper the transient model of a multi-split air conditioner with a digital scroll compressor is developed for predicting the system transients under performance modulations. The predicted cycling dynamics are in good agreement with the experimental data. Based on the validated model, the impact of compressor idle power and cycle period to the part load performance is discussed. © 2010 Published by Elsevier Ltd.

Yan G.,National University of Singapore | Ren J.,National University of Singapore | Ren J.,Los Alamos National Laboratory | Lai Y.-C.,Arizona State University | And 3 more authors.
Physical Review Letters | Year: 2012

The outstanding problem of controlling complex networks is relevant to many areas of science and engineering, and has the potential to generate technological breakthroughs as well. We address the physically important issue of the energy required for achieving control by deriving and validating scaling laws for the lower and upper energy bounds. These bounds represent a reasonable estimate of the energy cost associated with control, and provide a step forward from the current research on controllability toward ultimate control of complex networked dynamical systems. © 2012 American Physical Society.

Liang H.,Tongji University
Journal of Systems Science and Complexity | Year: 2011

Consider heteroscedastic regression model Y ni = g(x ni) + σ nie{open} ni (1 ≤ i ≤ n), where σ ni 2 = f(u ni), the design points (x ni, u ni) are known and nonrandom, g(·) and f(·) are unknown functions defined on closed interval [0, 1], and the random errors {e{open} ni, 1 ≤ i ≤ n} are assumed to have the same distribution as {ξ i, 1 ≤ i ≤ n}, which is a stationary and α-mixing time series with Eξ i = 0. Under appropriate conditions, we study asymptotic normality of wavelet estimators of g(·) and f(·). Finite sample behavior of the estimators is investigated via simulations, too. © 2011 Institute of Systems Science, Academy of Mathematics and Systems Science, CAS and Springer-Verlag Berlin Heidelberg.

Gao Y.-B.,Tongji University
Soils and Foundations | Year: 2013

A series of undrained and drained triaxial tests were conducted to investigate the yielding behavior of anisotropically consolidated reconstituted Shanghai clay under triaxial compression and extension loading conditions. The soil was consolidated with K of 0.5, where K is the ratio of cell pressure to axial pressure. The tests included drained constant η (q/p′) loading tests and undrained and drained triaxial compression and extension shear tests on anisotropically consolidated specimens. It was found that the anisotropically consolidated Shanghai clay obeys Rendulic's principle under compression loading, but not under extension loading, and that the yield surface inclined inside the state boundary surface under extension loading. Moreover, the pre-yield behavior and the post-yield behavior were found to be very different under these two loading conditions (compression and extension loading). The test results confirm the validity of the sloping elastic wall theory, and the influence of anisotropic parameter β on the shape of the yield curve in the p′-v plane was also studied in the paper. Constitutive modeling methods for anisotropic consolidated soils were also discussed based on the test results. © 2013 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.

Calcaneal fractures are rare injuries in children and adolescents, and fractures with displaced intra-articular fracture patterns are even more rare. The purpose of this study was to report 9 intra-articular calcaneal fractures in 8 children (mean age, 12.6 years; range,10-15 years) treated with open reduction and internal fixation (ORIF) and to examine cases reported in the literature to better define the classification characteristics and operational outcomes of this uncommon fracture. Preoperative radiographs and computed tomography scans were used to evaluate and classify the fractures. Clinical and radiographic examinations were performed at postoperative follow-up, and functional outcome was assessed with the modified American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score. Mean follow-up was 47 months (range, 21-72 months). Mean time to union was 9.2 weeks (range, 8-12 weeks). Mean modified AOFAS score was 65.2 points (range, 53-68 points). One foot experienced a minor complication.After a systematic review of the literature, 4 studies with a total of 35 patients (37 fractures) were included. All fractures were caused by high-energy injuries. Based on the Essex-Lopresti classification, 40.5% (15/37) were tongue-type fractures and 59.5% (22/37) were joint depression-type fractures. Based on the Sanders classification, 62.2% (23/37) of fractures were 2 parts, 32.4% (12/37) were 3 parts, and 5.4% (2/37) showed comminution. No significant difference was found in classification information between children and adults. The authors concluded that the characteristics of intra-articular calcaneal fractures in children are similar to those in adults, and operative treatment of these fractures yields good results with few complications. Copyright 2012, SLACK Incorporated.

Zhang Y.,Tongji University
Journal of the Franklin Institute | Year: 2013

The purpose of this paper is to investigate the exponential stability for discrete-time impulsive delay neural networks and the robust exponential stability for discrete-time impulsive delay neural networks with uncertainty. By using Lyapunov functionals, first some new results on exponential stability for neural networks without uncertainty are presented, and then some results on robust exponential stability for neural networks with uncertainty are provided. Both the stability results that impulses act as perturbations and the stability results that impulses act as stabilizer are given. The obtained results have the virtue that they can deal with neural networks with any fixed time delay. Moreover, the impulsive interval is larger than 2 or the time delay is not needed in the main results. Some examples together with their simulations are also presented to show the effectiveness and the advantage of the obtained results. © 2013 The Franklin Institute. Published by Elsevier Ltd. All rights reserved.

Shen H.,Purdue University | Tan H.,Tongji University | Tzempelikos A.,Purdue University
Energy and Buildings | Year: 2011

This paper presents an experimental study on the impact of reflective coatings on indoor environment and building energy consumption. Three types of coatings were applied on identical buildings and their performance was compared with three sets of experiments in both summer and winter. The first experiment considers the impact of coatings on exterior and interior surface temperatures, indoor air temperatures, globe temperature, thermal stratification and mean radiant temperatures for non-conditioned buildings (free-floating case); the second one focused on the impact of coatings on reduction of electricity consumption in conditioned spaces; in the third experiment, the impact of different envelope material properties equipped with different coatings was investigated. The results showed that, depending on location, season and orientation, exterior and interior surface temperatures can be reduced by up to 20 °C and 4.7 °C respectively using different coatings. The maximum reduction in globe temperature and mean radiant temperature was 2.3 °C and 3.7 °C in that order. For the conditioned case, the annual reduction in electricity consumption for electricity reached 116 kWh. Nevertheless, the penalty in increased heating demand can result in a negative all-year effect in Shanghai, which is characterized by hot summers and cold winters. © 2010 Elsevier B.V. All rights reserved.

Huang Z.,Jiangsu University | Chen Z.,Jiangsu University | Lv C.,Jiangsu University | Meng H.,Tongji University | Zhang C.,Jiangsu University
ACS Nano | Year: 2014

The exploitation of a low-cost catalyst is desirable for hydrogen generation from electrolysis or photoelectrolysis. In this study we have demonstrated that nickel phosphide (Ni12P5) nanoparticles have efficient and stable catalytic activity for the hydrogen evolution reaction. The catalytic performance of Ni12P5 nanoparticles is favorably comparable to those of recently reported efficient nonprecious catalysts. The optimal overpotential required for 20 mA/cm 2 current density is 143 ± 3 mV in acidic solution (H 2SO4, 0.5 M). The catalytic activity of Ni 12P5 is likely to be correlated with the charged natures of Ni and P. Ni12P5 nanoparticles were introduced to silicon nanowires, and the power conversion efficiency of the resulting composite is larger than that of silicon nanowires decorated with platinum particles. This result demonstrates the promising application potential of metal phosphide in photoelectrochemical hydrogen generation. © 2014 American Chemical Society.

A mathematical model for describing groundwater flow to a partially penetrating pumping well of a finite diameter in an anisotropic leaky confined aquifer is developed. The model accounts for the jointed effects of aquitard storage, aquifer anisotropy, and wellbore storage by treating the aquitard leakage as a boundary condition at the aquitard-aquifer interface rather than a volumetric source/sink term in the governing equation, which has never developed before. A new semi-analytical solution for the model is obtained by the Laplace transform in conjunction with separation of variables. Specific attention was paid on the flow across the aquitard-aquifer interface, which is of concern if aquitard and aquifer have different pore water chemistry. Moreover, Laplace-domain and steady-state solutions are obtained to calculate the rate and volume of (total) leakage through the aquitard-aquifer interface due to pump in a partially penetrating well, which is also useful for engineers to manager water resources. The sensitivity analyses for the drawdown illustrate that the drawdown is most sensitive to the well partial penetration. It is apparently sensitive to the aquifer anisotropic ratio over the entire time of pumping. It is moderately sensitive to the aquitard/aquifer specific storage ratio at the intermediate times only. It is moderately sensitive to the aquitard/aquifer vertical hydraulic conductivity ratio and the aquitard/aquifer thickness ratio with the identical influence at late times. © 2014 Elsevier B.V.

Zhou Y.-N.,Fudan University | Xue M.-Z.,Tongji University | Fu Z.-W.,Fudan University
Journal of Power Sources | Year: 2013

Extensive research is underway to yield greater insights into the intrinsic properties of electrode materials for lithium storage. Presently, nanostructured thin-film electrodes without any additives and binders used in powder-based electrodes have been employed as the "ideal" system for fundamental research because of their low resistance, cleanliness and purity. This review summarizes the research on, and progress in such nanostructured thin-film electrode materials for lithium storage and for all-solid-state thin film batteries. Nanostructured thin film electrodes with various electrochemical reaction mechanisms based on nanometer-size effects, chemical composition and structure are summarized. Thin film electrodes used in all-solid-state thin film batteries are also described. © 2013 Elsevier B.V. All rights reserved.

Wang W.,Tongji University
Applied Mechanics and Materials | Year: 2011

Based on interior configurations of railway vehicle of China and simulation using modeling of MADYMO Hybrid III 50% Dummy, the occupant injury of interior impact in railway crash events is analyzed according the European and American standard. The results indicated that in the face to face seating without table, the injury is serious then face to back and face to face with table. The other affect factors are the stiffness of interior equipment and the distance of seats. It is needed to optimize the parameter of interior equipment to reduce injury risk for the occupants under collision scenarios. At last the suggestions and methods for railway vehicle occupant safety protection are put forward in the paper. © (2011) Trans Tech Publications.

Shen H.,Tongji University
Molecular Physics | Year: 2014

Molecular dynamics method was used to simulate the twists of four GNRs (graphene nanoribbons), two AGNRs (armchair GNRs), and two ZGNRs (zigzag GNRs). Thermal conductivity of the length-fixing GNRs under torsion and at high temperature was calculated. It is found that the ZGNRs have better torsional rigidity than the AGNRs; under the torsional deformation of 34.2°/nm local buckling occurs in the length-fixing GNRs, and under the deformation of 22.8°/nm overall buckling occurs in the ones with free-length. In the range of investigated twist-angle and temperature, the thermal conductivity of the length-fixing GNRs decreases with the increase of torsional deformation and temperature. The wider GNRs have better anti-torsion capability and thermal conductivity. © 2014 Taylor & Francis.

The study investigated the effects and mechanism of duodenal-jejunal bypass (DJB) and sleeve gastrectomy (SG) on the expression of liver GLUT2 and glucokinase (GCK) in diabetic rats. Animal models of Goto-Kakizaki (GK) rats were established for the investigation of DJB and SG. Results of weight, food intake, fasting plasma glucose level, oral glucose tolerance test and insulin were compared. Liver tissues were harvested 8 weeks postoperatively. Reverse transcription-PCR and western blot were used to detect liver GLUT2 and GCK mRNA and protein expression after operation. Fasting plasma glucose levels of DJB group and SG group in GK rats were markedly declined at 3 days and l, 2, 4, 6, and 8 weeks postoperatively (P <0.01), whereas the levels of the sham-operated group only dropped at 3 days and 1 week postoperatively, and there were no significant differences 2 weeks postoperatively (P >0.05). In the liver of GK rats, GLUT2 mRNA level and protein expression after DJB were higher than those in sham-operated group and control group. GLUT2 mRNA level and protein expression after SG were significantly lower than those in control group (P <0.01). GCK mRNA and protein experienced similar expression change. Both DJB and SG can decrease the plasma glucose levels of GK rats, whereas they have different effects on the expression of liver GLUT2 and GCK.

A rapid, simple, and low-cost diagnostic tool for tuberculosis (TB) detection is urgently needed in countries with a high TB burden. Here, we report a novel loop-mediated isothermal amplification (LAMP) assay targeting the hspX gene for the rapid detection of Mycobacterium tuberculosis, M. bovis, M. africanum, and M. microti. The specificity of this assay was evaluated using 4 reference strains of Mycobacterium tuberculosis complex (MTC), 22 species of non-tuberculous mycobacteria (NTM), 7 non-mycobacterial species, and 50 clinical M. tuberculosis isolates. All the reference MTC strains and M. tuberculosis clinical isolates were successfully detected by this method, and there were no false-positive results with NTM or non-mycobacterial species, which demonstrates the high specificity of this assay for MTC. The detection limit was 10 copies of MTC genome within 27 min, and the detection speed of this assay was higher than that of any other isothermal methods reported so far. Because of its speed, simplicity, sensitivity, specificity, and inexpensiveness, the TB hspX LAMP assay is a potential gene diagnostic method for TB detection in developing countries with a high TB burden.

CCL21 is known to attract dendritic cells (DCs) and T cells that may reverse tumor-mediated immune suppression. The massive infiltration of tumors by regulatory T cells (Tregs) prevents the development of a successful helper immune response. In this study, we investigated whether elimination of CD4(+) CD25(+) Tregs in the tumor microenvironment using anti-CD25 monoclonal antibodies (mAbs) was capable of enhancing CCL21-mediated antitumor immunity in a mouse hepatocellular carcinoma (HCC) model. We found that CCL21 in combination with anti-CD25 mAbs (PC61) resulted in improved antitumor efficacy and prolonged survival, not only inhibited tumor angiogenesis and cell proliferation, but also led to significant increases in the frequency of CD4(+), CD8(+) T cells and CD11c(+) DCs within the tumor, coincident with marked induction of tumor-specific CD8(+) cytotoxic T lymphocytes (CTLs) at the local tumor site. The intratumoral immune responses were accompanied by the enhanced elaboration of IL-12 and IFN-γ, but reduced release of the immunosuppressive mediators IL-10 and TGF-β1. The results indicated that depletion of Tregs in the tumor microenvironment could enhance CCL21-mediated antitumor immunity, and CCL21 combined with anti-CD25 mAbs may be a more effective immunotherapy to promote tumor rejection.

Ding X.,Tongji University | Ding X.,Seoul National University
Journal of Materials Chemistry C | Year: 2014

We report the fabrication and characterization of large-scale graphene quantum dots (GQDs) grown on hexagonal boron nitride (h-BN) substrates with different layers and similar size of island diameters. The GQDs on h-BN synthesized by chemical vapor deposition (CVD) exhibit excellent morphology, unambiguous interfaces and well-ordered arrangement. These characteristics were achieved by adjusting the control parameters in the growth process, including the gas flow rate, temperature and pressure. The synthesized GQDs were shown to possess a thickness-dependent photoluminescence (PL) feature. Broad and red-shift emission features in monolayer GQDs suggest that the inhomogeneity of the surfaces, shapes and edges in the quantum dots of the nearby one-layer thickness sensitively affect the PL spectra. However, the GQDs with a thickness of more than 10 layers emit very sharp PL spectra with nearly identical shape and position independent of the excitation wavelength. The results suggest routes towards creating large-scale optoelectronic devices in solid-state white-light emission, photovoltaic solar cells, and flat panel displays. © 2014 the Partner Organisations.

Li X.Z.,Tongji University
Zhongguo Zhong xi yi jie he za zhi Zhongguo Zhongxiyi jiehe zazhi = Chinese journal of integrated traditional and Western medicine / Zhongguo Zhong xi yi jie he xue hui, Zhongguo Zhong yi yan jiu yuan zhu ban | Year: 2011

To investigate the accumulation of advanced glycation end products (AGEs) and expression of receptor for AGEs (RAGE) in streptozocin (STZ)-induced diabetic nephropathy in rats, and the role of antioxidants on the AGEs-RAGE signaling. Diabetic rats were induced by once intraperitoneal injection of STZ at the dose of 60 mg/kg, and randomly divided into the DN group (n=12, treated with normal saline by intraperitoneal injection, once daily), the extract of Ginkgo biloba (EGb) group (n=14, treated with EGb 300 mg/kg by oral administration, once every other day), and the alpha-lipoic acid (ALA) group (n=12, treated with ALA at the dose of 35 mg/kg by intraperitoneal injection, once every other day). Rats of the normal control group (n=10) were given vehicle citrate buffer at the dose of 60 mg/kg. Rats were sacrificed at the 12th week and the 20th week of this study. The four groups were compared in terms of body weight, blood glucose, renal function, 24-h urine protein. Renal pathological changes were observed by PAS staining. Oxidative stress indices were detected using spectrophotometry. The concentrations of AGEs were measured using fluoro spectrophotometry, and the expressions of RAGE were detected by Real-time PCR and Western blot. Compared with the normal control group, the 24-h urine protein quantitation was higher and the glomerular filtration rate increased in rats at the 12th week and the 20th week. The pathological tissue staining showed dilated glomerular mesangium, proliferated glomerular matrix, vacuolar degeneration of the renal tubular epithelium. Malonaldehyde (MDA) levels and 8-hydroxide radical guanine deoxyriboside (8-OHdG) levels increased, and catalase (CAT) and reduced glutathione hormone (GSH) levels decreased. The AGEs contents in serum and renal tissue homogenate increased. The expressions of RAGE mRNA and protein increased in the DN group at the 12th and the 20th week. The 24-h urine protein quantitation was reduced in the EGb group and the ALA group, with alleviated pathological changes, lowered MDA and 8-OHdG levels, increased CAT and GSH levels, decreased AGEs contents, and down-regulated RAGE expressions. AGEs contents increased and RAGE expression up-regulated in the circulation and local renal tissues in DN rats. EGb and ALA could inhibit AGEs production and down-regulate RAGE expressions by reducing oxidative stress, thus further improving the renal tissue structure and renal functions of DN rats. It had better application prospect in treatment and prevention of DN.

Coggins M.K.,University of North Carolina at Chapel Hill | Zhang M.-T.,University of North Carolina at Chapel Hill | Zhang M.-T.,Tsinghua University | Chen Z.,University of North Carolina at Chapel Hill | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2014

The complex CuII(Py3P) (1) is an electrocatalyst for water oxidation to dioxygen in H2PO4 -/HPO4 2- buffered aqueous solutions. Controlled potential electrolysis experiments with 1 at pH 8.0 at an applied potential of 1.40 V versus the normal hydrogen electrode resulted in the formation of dioxygen (84 % Faradaic yield) through multiple catalyst turnovers with minimal catalyst deactivation. The results of an electrochemical kinetics study point to a single-site mechanism for water oxidation catalysis with involvement of phosphate buffer anions either through atom-proton transfer in a rate-limiting O-O bond-forming step with HPO4 2- as the acceptor base or by concerted electron-proton transfer with electron transfer to the electrode and proton transfer to the HPO4 2- base. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dong H.,Hong Kong University of Science and Technology | Guan X.,Tongji University | Lo I.M.C.,Hong Kong University of Science and Technology
Water Research | Year: 2012

Nano zero-valent iron (NZVI) offers a promising approach for arsenic remediation, but the spent NZVI with elevated arsenic content could arouse safety concerns. This study investigated the fate of As(V)-treated NZVI (As-NZVI), by examining the desorption potential of As under varying conditions. The desorption kinetics of As from As-NZVI as induced by phosphate was well described by a biphasic rate model. The effects of As(V)/NZVI mass ratio, pH, and aging time on arsenic desorption from As-NZVI by phosphate were investigated. Less arsenic desorption was observed at lower pH or higher As(V)/NZVI mass ratio, where stronger complexes (bidentate) formed between As(V) and NZVI corrosion products as indicated by FTIR analysis. Compared with the fresh As-NZVI, the amount of phosphate-extractable As significantly decreased in As-NZVI aged for 30 or 60 days. The results of the sequential extraction experiments demonstrated that a larger fraction of As was sorbed in the crystalline phases after aging, making it less susceptible to phosphate displacement. However, at pH 9, a slightly higher proportion of phosphate-extractable As was observed in the 60-day sample than in the 30-day sample. XPS results revealed the transformation of As(V) to more easily desorbed As(III) during aging and a higher As(III)/As(V) ratio in the 60-day sample at pH 9, which might have resulted in the higher desorption. © 2012 Elsevier Ltd.

Large-scale time-evolving networks have been generated by many natural and technological applications, posing challenges for computation and modeling. Thus, it is of theoretical and practical significance to probe mathematical tools tailored for evolving networks. In this paper, on top of the dynamic Estrada index, we study the dynamic Laplacian Estrada index and the dynamic normalized Laplacian Estrada index of evolving graphs. Using linear algebra techniques, we established general upper and lower bounds for these graph-spectrumbased invariants through a couple of intuitive graph-theoretic measures, including the number of vertices or edges. Synthetic random evolving small-world networks are employed to show the relevance of the proposed dynamic Estrada indices. It is found that neither the static snapshot graphs nor the aggregated graph can approximate the evolving graph itself, indicating the fundamental difference between the static and dynamic Estrada indices. © 2015 Yilun Shang.

Yu X.,Tongji University
Applied Mechanics and Materials | Year: 2012

Internal combustion Rankine cycle engine uses oxygen instead of air as oxidant during the combustion process in gasoline engine. Recycled fluid is employed to control the reaction rate and recycles the exhaust heat inside the cylinder as well. CO 2 could be recaptured after separated from the exhaust gas (CO 2 and water vapor) during condensation, and an ultra-low emission working cycle is achieved. Considering the side effects of water injection process, EGR is employed to control the combustion process and thermal efficiency of the oxy-fuel combustion cycle is calculated and optimized in this paper. Results show that the application of EGR could slow down the combustion process effectively, and appropriate EGR rate matched with ignition timing would control the reaction rate and cylinder pressure, therefore enhance the engine performance. © (2012) Trans Tech Publications, Switzerland.

Zhao Y.,Hefei University of Technology | Zhao Y.,Chinese Academy of science | Huang D.-S.,Tongji University | Jia W.,Chinese Academy of science
IEEE Transactions on Image Processing | Year: 2012

In this brief, a novel local descriptor, named local binary count (LBC), is proposed for rotation invariant texture classification. The proposed LBC can extract the local binary grayscale difference information, and totally abandon the local binary structural information. Although the LBC codes do not represent visual microstructure, the statistics of LBC features can represent the local texture effectively. In addition, a completed LBC (CLBC) is also proposed to enhance the performance of texture classification. Experimental results obtained from three databases demonstrate that the proposed CLBC can achieve comparable accurate classification rates with completed local binary pattern. © 1992-2012 IEEE.

Tong M.S.,Tongji University
IEEE Transactions on Components, Packaging and Manufacturing Technology | Year: 2011

Efficient electromagnetic analysis for interconnect and packaging structures is developed by solving surface integral equations (SIEs) with the method of moments. Since the SIEs include both electric and magnetic currents as unknowns on the interfaces of dielectric materials, two basis functions are needed to represent them. The robust Rao-Wilton-Glisson (RWG) basis function is a natural choice to represent the electric current, but how one represents the magnetic current is less obvious. One may employ n × RWG basis function, where n is a unit normal vector on the material interfaces or the RWG basis function again to represent the magnetic current, but both choices are not ideal. In this paper, we use the dual basis function proposed by Chen and Wilton in 1990 to represent the magnetic current, and find that it is robust though complicated in implementation. The interconnect and packaging analysis requires extra cares on numerical procedure because of the multiscale features and low-frequency effects of the structures. With the use of RWG and dual basis functions together, both electric and magnetic currents are well represented and the system matrix is well conditioned. Therefore, the low-frequency effects are alleviated and the poor mesh quality can be sustained without special treatment. Numerical examples for typical structures are presented to illustrate the merits of the scheme. © 2011-2012 IEEE.

Changshui Z.,Tsinghua University | Guangdong H.,Tsinghua University | Jun W.,Tongji University
Renewable Energy | Year: 2011

In the design of a wind farm, the placement of turbines is an important factor that affects the efficiency and profit, but automatic placement of turbines is still a challenging problem.This study reveals the " submodular" property of the wind turbine positioning problem based on Jensen wake model. Based on this property, a " lazy greedy" algorithm is used to optimize the placement. This method can obtain solutions with theoretical guarantee of quality. It can also estimate the lower bound of the optimal value of the objective function. This method is tested on three types of wind scenarios. Compared to previous research, this algorithm takes much less time, and always gains a better solution.To enlarge the application scope, the wake model is extended to the large scale complex terrain in this study. The present algorithm and some other algorithms are tested in the simulation of the complex terrain. The experimental results demonstrate the present method's superior performance. © 2011 Elsevier Ltd.

OBJECTIVE: The interleukin (IL)-23/IL-17 axis plays an important role in various inflammatory conditions but its function in acute pancreatitis (AP) is not well understood. The present study investigated the relationship between serum levels of IL-23, IL-17, and C-reactive protein (CRP) in patients and the severity of AP.METHODS: Eighty-five patients with AP were categorized into mild group, moderately severe group, and severe group according to the revised Atlanta classification, 2012. Serum levels of IL-23 and IL-17 were measured by enzyme-linked immunosorbent assay in patients 48 hours after admission. The CRP levels of patients were also measured on admission and 48 hours after admission.RESULTS: The serum levels of CRP of patients on admission and 48 hours after admission and levels of IL-23 and IL-17 of patients 48 hours after admission increased alone with the severity of AP, respectively (P < 0.01). The serum levels of IL-23 and IL-17 in the patients were correlated with CRP levels (r = 0.234, r = 0.552, P < 0.001, respectively).CONCLUSIONS: The serum levels of IL-17, IL-23, and CRP are correlated with the severity of AP and represent valuable prognostic factors in the assessment of disease severity of patients with AP. © 2014 by Lippincott Williams & Wilkins.

A high level of plasma homocysteine (Hcy) increases the risk for neurodegenerative diseases. One such disorder is Alzheimer's disease, which involves marked neuronal apoptosis of unknown etiology. This study shows that Hcy inhibits expression of 14-3-3ε and activates calcineurin in rat hippocampal neurons in a dose-dependent manner. Calcineurin-mediated Bad dephosphorylation, which is blocked by calcineurin inhibition and Ca(2+) chelation, causes mitochondrial translocation of Bad and apoptosis; this step in the apoptotic pathway is synergistically blocked by calcineurin inhibition and overexpression of 14-3-3ε. These findings demonstrated that calcineurin activation and downregulation of 14-3-3ε may be one of the mechanisms of Hcy-induced apoptosis of hippocampal neurons.

Lin R.,Fudan University | Tao R.,Tongji University | Gao X.,Fudan University | Li T.,Fudan University | And 6 more authors.
Molecular Cell | Year: 2013

Increased fatty acid synthesis is required to meet the demand for membrane expansion of rapidly growing cells. ATP-citrate lyase (ACLY) is upregulated or activated in several types of cancer, and inhibition of ACLY arrests proliferation of cancer cells. Here we show that ACLY is acetylated at lysine residues 540, 546, and 554 (3K). Acetylation at these three lysine residues is stimulated by P300/calcium-binding protein (CBP)-associated factor (PCAF) acetyltransferase under high glucose and increases ACLY stability by blocking its ubiquitylation and degradation. Conversely, the protein deacetylase sirtuin 2 (SIRT2) deacetylates and destabilizes ACLY. Substitution of 3K abolishes ACLY ubiquitylation and promotes de novo lipid synthesis, cell proliferation, and tumor growth. Importantly, 3K acetylation of ACLY is increased in human lung cancers. Our study reveals a crosstalk between acetylation and ubiquitylation by competing for the same lysine residues in the regulation of fatty acid synthesis and cell growth in response to glucose. © 2013 Elsevier Inc.

Liu H.-C.,Tokyo Institute of Technology | Liu L.,Tongji University | Lin Q.-L.,TU Berlin
IEEE Transactions on Reliability | Year: 2013

The main objective of this paper is to propose a new risk priority model for prioritizing failures in failure mode and effects analysis (FMEA) on the basis of fuzzy evidential reasoning (FER) and belief rule-based (BRB) methodology. The technique is particularly intended to resolve some of the shortcomings in fuzzy FMEA (i.e., fuzzy rule-based) approaches. In the proposed approach, risk factors like occurrence (O), severity (S), and detection (D), along with their relative importance weights, are described using fuzzy belief structures. The FER approach is used to capture and aggregate the diversified, uncertain assessment information given by the FMEA team members; the BRB methodology is used to model the uncertainty, and nonlinear relationships between risk factors and corresponding risk level; and the inference of the rule-based system is implemented using the weighted average-maximum composition algorithm. The Dempster rule of combination is then used to aggregate all relevant rules for assessing and prioritizing the failure modes that have been identified in FMEA. A case study concerning an ocean going fishing vessel in a marine industry is provided and conducted using the proposed model to illustrate its potential applications and benefits. © 1963-2012 IEEE.

Zhang J.,Tongji University
European review for medical and pharmacological sciences | Year: 2012

The objective of this study was to investigate the association between platelet glycoprotein (GP) Ia C807T polymorphisms and ischemic stroke in young Chinese Han Population. We conducted a case-control study in 92 consecutive young ( 50 years), and 160 age- and sex-matched healthy control. Genotyping of platelet GP Ia C807Tpolymorphisms was performed by polymerase chain reaction followed by sequencing nucleic acid with dideoxy chain-termination method and an ABI PRISM3100 (Perkin-Elmer Co) genetic analyzer. Student's t-test, chi-square test, and logistic regression modeling were used for data significance analyses. Hypertension and smoking were found to be the independent risk factors for ischemic stroke patients (aged 50 years). There was no significant difference observed in the T allele frequency of GPIa C807T polymorphisms between young stroke patients and corresponding controls. These findings suggest that there is no role of GPIa C807T polymorphisms in the development of young first-ever ischemic stroke in Chinese Han Population.

Lu D.,Tulane University | Lu D.,Tongji University | Han C.,Tulane University | Wu T.,Tulane University
Gastroenterology | Year: 2011

Background & Aims: Microsomal prostaglandin E synthase-1 (mPGES-1) is a rate-limiting enzyme that is coupled with cyclooxygenase (COX)-2 in the synthesis of prostaglandin E2. Although COX-2 is involved in the development and progression of various human cancers, the role of mPGES-1 in carcinogenesis has not been determined. We investigated the role of mPGES-1 in human cholangiocarcinoma growth. Methods: We used immunohistochemical analyses to examine the expression of mPGES-1 in formalin-fixed, paraffin-embedded human cholangiocarcinoma tissues. The effects of mPGES-1 on human cholangiocarcinoma cells were determined in vitro and in SCID mice. Immunoblotting and immunoprecipitation assays were performed to determine the levels of PTEN and related signaling molecules in human cholangiocarcinoma cells with overexpression or knockdown of mPGES-1. Results: mPGES-1 is overexpressed in human cholangiocarcinoma tissues. Overexpression of mPGES-1 in human cholangiocarcinoma cells increased tumor cell proliferation, migration, invasion, and colony formation; in contrast, RNA interference knockdown of mPGES-1 inhibited tumor growth parameters. In SCID mice with tumor xenografts, mPGES-1 overexpression accelerated tumor formation and increased tumor weight (P < .01), whereas mPGES-1 knockdown delayed tumor formation and reduced tumor weight (P < .01). mPGES-1 inhibited the expression of phosphatase and tensin homologue deleted on chromosome 10 (PTEN), leading to activation of the epidermal growth factor/phosphoinositide 3-kinase/AKT/mammalian target of rapamycin signaling pathways in cholangiocarcinoma cells. mPGES-1mediated inhibition of PTEN is regulated through blocking of early growth response-1 sumoylation and binding to the 5′-untranslated region of the PTEN gene. Conclusions: mPGES-1 promotes experimental cholangiocarcinogenesis and tumor progression by inhibiting PTEN. © 2011 AGA Institute.

Wang H.,Tongji University
Chinese Physics Letters | Year: 2015

First-principles calculations predict that SrFBiS2 has a superior birefringence of 1.28, which is larger than the giant birefringence of LaOBiS2 [Wang H, Chin. Phys. Lett. 31 (2013) 047802]. An AF layer (i.e., SrF) is shown to be important by the further investigations on AFBiS2 (A=Mg, Ca, Ba). Here MgFBiS2 exhibits the largest inherent birefringence (∼1.66) among single-crystal compounds. The origin of SBF is also discussed based on the electronic structure and refractive index. © 2015 Chinese Physical Society and IOP Publishing Ltd.

El-Mowafy A.,Curtin University Australia | Hu C.,Tongji University
Journal of Applied Geodesy | Year: 2014

This study presents validation of BeiDou measurements in un-differenced standalone mode and experimental results of its application for real data. A reparameterized form of the unknowns in a geometry-free observation model was used. Observations from each satellite are independently screened using a local modeling approach. Main advantages include that there is no need for computation of inter-system biases and no satellite navigation information are needed. Validation of the triple-frequency BeiDou data was performed in static and kinematic modes, the former at two continuously operating reference stations in Australia using data that span two consecutive days and the later in a walking mode for three hours. The use of the validation method parameters for numerical and graphical diagnostics of the multi-frequency BeiDou observations are discussed. The precision of the system's observations was estimated using an empirical method that utilizes the characteristics of the validation statistics. The capability of the proposed method is demonstrated in detection and identification of artificial errors inserted in the static BeiDou data and when implemented in a single point positioning processing of the kinematic test. © 2014 by Walter de Gruyter Berlin/Boston.

Chen J.,National University of Singapore | Zhang G.,Peking University | Li B.,National University of Singapore | Li B.,Tongji University
Nano Letters | Year: 2012

By using nonequilibrium molecular dynamics simulations, we demonstrated that thermal conductivity of germanium nanowires can be reduced more than 25% at room temperature by atomistic coating. There is a critical coating thickness beyond which thermal conductivity of the coated nanowire is larger than that of the host nanowire. The diameter-dependent critical coating thickness and minimum thermal conductivity are explored. Moreover, we found that interface roughness can induce further reduction of thermal conductivity in coated nanowires. From the vibrational eigenmode analysis, it is found that coating induces localization for low-frequency phonons, while interface roughness localizes the high-frequency phonons. Our results provide an available approach to tune thermal conductivity of nanowires by atomic layer coating. © 2012 American Chemical Society.

Liu C.,Tongji University
Shiyou Xuebao/Acta Petrolei Sinica | Year: 2010

High resolution study on the source rocks in Yacheng Formation and Lingshui Formation of Qiongdongnan Basin was carried out by using the backscattered electron imaging (BSEI) technology. The study results show that the organic matters of these source rocks include foraminifers, calcareous nannofossils, organic matter lamination and terrigenous plant debris. The organic matters were distributed in source rocks with four types of continuous lamination, intermittent lamination, scatter and flocculation. According to the composition and distribution characteristics of organic matters, five types of source rocks in Qiongdongnan Basin can be subdivided, including the continuous lamination mudstone, intermittent lamination mudstone, foraminiferal and calcareous nannofossil mudstone, terrigenous plant debris mudstone and scattering organic matter mudstone. The quantitative analysis on calcareous nannofossil of the Oligocene rock samples obtained from 5 wells was carried out. According to the nannofossil assemblages, abundance and diversity, it is suggested that the sedimentary environments of the Oligocene source rocks are the littoral environment and shallow sea environment.

Liu Z.,Tongji University | Cao A.T.,University of Texas Medical Branch | Cong Y.,University of Texas Medical Branch
Seminars in Cancer Biology | Year: 2013

The host and microbiota have evolved mechanisms for coexistence over millions of years. Accumulating evidence indicates that a dynamic mutualism between the host and the commensal microbiota has important implications for health, and microbial colonization contributes to the maintenance of intestinal immune homeostasis. However, alterations in communication between the mucosal immune system and gut microbial communities have been implicated as the core defect that leads to chronic intestinal inflammation and cancer development. We will discuss the recent progress on how gut microbiota regulates intestinal homeostasis and the pathogenesis of inflammatory bowel disease and colorectal cancer. © 2013 Elsevier Ltd.

Han T.,National University of Singapore | Bai X.,National University of Singapore | Gao D.,National University of Singapore | Thong J.T.L.,National University of Singapore | And 3 more authors.
Physical Review Letters | Year: 2014

Invisibility has attracted intensive research in various communities, e.g., optics, electromagnetics, acoustics, thermodynamics, dc, etc. However, many experimental demonstrations have only been achieved by virtue of simplified approaches due to the inhomogeneous and extreme parameters imposed by the transformation-optic method, and usually require a challenging realization with metamaterials. In this Letter, we demonstrate a bilayer thermal cloak made of bulk isotropic materials, and it has been validated as an exact cloak. We experimentally verified its ability to maintain the heat front and its heat protection capabilities in a 2D proof-of-concept experiment. The robustness of this scheme is validated in both 2D (including oblique heat front incidence) and 3D configurations. The proposed scheme may open a new avenue to control the diffusive heat flow in ways inconceivable with phonons, and also inspire new alternatives to the functionalities promised by transformation optics. © 2014 American Physical Society.

Xia Q.,Tongji University
Zhongguo shi yan xue ye xue za zhi / Zhongguo bing li sheng li xue hui = Journal of experimental hematology / Chinese Association of Pathophysiology | Year: 2012

This study was aimed to investigate the abnormal expression of microRNA-124 (miR-124) in bone marrow cells of patients with leukemia or myelodysplastic syndrome (MDS) and its significance. The relative expression levels of miR-124 in bone marrow mononuclear cells from 33 patients with newly diagnosed leukemia or MDS, and 10 normal donors (as controls) were detected by stem-loop fluorescence real-time quantitative RT-PCR. The methylation levels of miR-124 promoter were detected by quantitative methylation specific PCR in partial MDS samples. The results indicated that as compared with normal control, lower levels of miR-124 (≤ 1/3) were found in 2/18 of leukemia patients and in 5/15 of MDS patients (among them ≤ 1/4 in 3/15 MDS patients). No statistically significance difference was observed between leukemia patients and normal controls (P = 0.725). However the difference was statistically significant between MDS group and control group (P = 0.031). Furthermore, an elevated methylation level of miR-124 promoter region in some of MDS patients (7/11) was detected by using quantitative methylation-specific PCR. The expression level of miR-124 was related with methylation level of promoter region (R(2) = 0.339, P = 0.018). It is concluded that the expression of miR-124 in partial MDS patients is inhibited, which may be associated with the abnormal methylation of its promoter.

Zhou J.,Tongji University
IEEE Photonics Technology Letters | Year: 2010

In this letter, an all-optical discrete Fourier transform (DFT) device based on multimode interference (MMI) couplers is proposed. The DFT device is composed of a discrete sine transform device and a discrete cosine transform device, both of which are based on MMI couplers. The main advantage of this DFT device is that it is composed of two compact MMI couplers, which greatly reduces the fabrication effort on planar lightwave circuits. © 2006 IEEE.

To build an effective nonlinear three-dimensional finite-element (FE) model of T(11)-L(3) segments for a further biomechanical study of thoracolumbar spine. The CT (computed tomography) scan images of healthy adult T(11)-L(3) segments were imported into software Simpleware 2.0 to generate a triangular mesh model. Using software Geomagic 8 for model repair and optimization, a solid model was generated into the finite element software Abaqus 6.9. The reasonable element C3D8 was selected for bone structures. Created between bony endplates, the intervertebral disc was subdivided into nucleus pulposus and annulus fibrosus (44% nucleus, 56% annulus). The nucleus was filled with 5 layers of 8-node solid elements and annulus reinforced by 8 crisscross collagenous fiber layers. The nucleus and annulus were meshed by C3D8RH while the collagen fibers meshed by two node-truss elements. The anterior (ALL) and posterior (PLL) longitudinal ligaments, flavum (FL), supraspinous (SSL), interspinous (ISL) and intertransverse (ITL) ligaments were modeled with S4R shell elements while capsular ligament (CL) was modeled with 3-node shell element. All surrounding ligaments were represented by envelope of 1 mm uniform thickness. The discs and bone structures were modeled with hyper-elastic and elasto-plastic material laws respectively while the ligaments governed by visco-elastic material law. The nonlinear three-dimensional finite-element model of T(11)-L(3) segments was generated and its efficacy verified through validating the geometric similarity and disc load-displacement and stress distribution under the impact of violence. Using ABAQUS/ EXPLICIT 6.9 the explicit dynamic finite element solver, the impact test was simulated in vitro. In this study, a 3-dimensional, nonlinear FE model including 5 vertebrae, 4 intervertebral discs and 7 ligaments consisted of 78 887 elements and 71 939 nodes. The model had good geometric similarity under the same conditions. The results of FEM intervertebral disc load-displacement curve were similar to those of in vitro test. The stress distribution results of vertebral cortical bone, posterior complex and cancellous bone were similar to those of other static experiments in a dynamic impact test under the observation of stress cloud. With the advantages of high geometric and mechanical similarity and complete thoracolumbar, hexahedral meshes, nonlinear finite element model may facilitate the impact loading test for a further dynamic analysis of injury mechanism for thoracolumbar burst fracture.

In this letter, all-optical two-dimensional discrete sine transform and discrete cosine transform (2DDST/DCT) are proposed to be realized on two-dimensional multimode interference (2DMMI) couplers. Similar to the one-dimensional case, the 2DDST/DCT requires only one 2DMMI coupler and a few phase shifters. © 2006 IEEE.

Zhang Y.,Tongji University
IET Control Theory and Applications | Year: 2013

The purpose of this study is to investigate the stability for a class of discrete-time delay Markovian jump systems with stochastic non-linearity and impulses. By using stochastic Lyapunov functionals, some new results are given. Impulse effects on the stability of the systems are revealed. Some examples together with their simulations are also presented to illustrate the effectiveness of the proposed results. © The Institution of Engineering and Technology 2013.

Huang X.-L.,Tongji University | Wang G.,Harbin Institute of Technology | Hu F.,University of Alabama
IEEE Transactions on Vehicular Technology | Year: 2013

Recently, compressive sensing (CS) and spectrum sensing have been two hot topics in the signal processing and cognitive radio network (CRN) fields, respectively. Due to the sampling rate limitation of the analog-to-digital converter in spectrum-sensing circuits, some works have proposed integrating these two techniques to achieve low-overhead spectrum sensing in CRNs. These works aim to minimize spectrum reconstruction errors based on linear regression methods, and ℓ1-norm is typically used to make a tradeoff between spectrum sparseness and reconstruction accuracy. However, since the interference range of primary users is limited, multiple clusters in the CRN may not share a common sparse spectrum, and thus, the ℓ1-norm may not be appropriate to handle all clusters in CS inversion. Hence, we propose a novel multitask spectrum-sensing method based on spatiotemporal data mining methods. In each cluster, we assume that the spectrum sensing is executed in a synchronized way. The cluster head (CH) manages the operations, and a common sparseness hyperparameter is used to make a consensus decision. Among multiple clusters, synchronized CS sampling is not required in our scheme; instead, the Dirichlet process prior is employed to make an automatic grouping of the spectrum-sensing results among different clusters with a common sparseness hyperparameter shared inside each group. To exploit the time-domain relevance among consecutive CS observations, a hidden Markov model is employed to describe the relationship between the hidden subcarrier states and the consecutive CS observations, and the Viterbi algorithm is used to make an accurate spectrum decision for each secondary user. Simulation results show that our proposed algorithm can successfully exploit the spatiotemporal relationship to achieve higher spectrum-sensing performance in terms of normalized mean square error, probability of correct detection, and probability of false alarm, compared with a few other related works. © 1967-2012 IEEE.

Ding Z.,Tongji University | Tamura Y.,Tokyo Polytechnic University
Journal of Wind Engineering and Industrial Aerodynamics | Year: 2013

Internal forces in cladding support components of large-span roof structures under wind loads were usually estimated only based on the local wind loads imposed on tributary areas. However, internal forces on such members depend not only on local behaviors caused by local wind loads but also on wind-induced overall behaviors of main structural frames. By ignoring the contribution of overall behaviors of main structural frames, internal forces in cladding support components may be underestimated following current wind load codes or recommendations. It is necessary to investigate the contributions of local and overall behaviors to improve the wind-resistant design of the cladding support component members on large-span roof systems. In this paper, a method was proposed to separate the internal forces of cladding support components due to wind-induced local and overall behaviors and investigate the corresponding contributions for the largest internal forces. Wind loads used for loading effects estimation were obtained based on wind pressures measured from a 1:400 scaled roof model under a boundary layer wind flow configuration. Wind loading effects considering wind-induced total behaviors (overall behaviors and local behaviors together) for axial force, bending moment and shear force were calculated by time-history analysis using finite element (FE) models of the prototype structure. Meanwhile, internal forces in cladding support components only considering local behaviors were extracted by using local wind loads based on quasi-static assumption. Finally, based on the contributions to the largest wind-induced internal forces resulting from the proposed method, a procedure for remedying the current wind load codes for such members were discussed. © 2013 Elsevier Ltd.