Zhang C.,Dalian University
Surgical Laparoscopy, Endoscopy and Percutaneous Techniques | Year: 2017
BACKGROUND:: The formation of gallbladder stones is associated with dysfunctional contraction and duodenal papilla diseases. However, endoscopic sphincterotomy can improve the contraction of the gallbladder and resolve duodenal papilla disease. AIM:: The aim of the study was to assess the feasibility and effectiveness of endoscopic sphincterotomy in the treatment of muddy stones or sludge in the gallbladder during papillary disease. METHODS:: The clinical data of 53 patients with gallbladder muddy stones or sludge undergoing endoscopic sphincterotomy were retrospectively analyzed. RESULTS:: A total of 53 patients received successful endoscopic sphincterotomy with no serious complications. Sphincterotomy did not significantly lower resting gallbladder volume from 63.2±10.8 to 50.1±5.9 mL (P>0.05), but significantly increased gallbladder ejection fraction from 0.41±0.13 to 0.63±0.16 (P<0.01), as measured by the lipoid food test. The static liver and gallbladder imaging examination also showed an increase in gallbladder ejection fraction from 0.45±0.08 to 0.68±0.11 (P<0.01). In addition, the choledochus pressure reduced from 21.9±4.0 to 15.6±2.5 mm Hg, and the gallbladder muddy stones or sludge disappeared after endoscopic sphincterotomy. At the end of the follow-up period, there was no relapse of sludge or muddy stones in the gallbladder. CONCLUSIONS:: The formation of gallbladder muddy stones or sludge is associated with papilla disease. Endoscopic sphincterotomy can resolve papilla disease, decrease gallbladder bile stasis, improve gallbladder evacuation, and prevent the formation of gallbladder stones. Copyright © 2017 Wolters Kluwer Health, Inc. All rights reserved.
Niu Y.-J.,Dalian University |
Wang X.-Y.,Dalian University of Technology
Nonlinear Dynamics | Year: 2013
This paper is concerned with the stabilization problem for a class of uncertain chaotic systems. Based on a set of linguistic rules, a novel variable universe fuzzy sliding-mode control approach is designed to improve the robustness and the stability of system. Based on Lyapunov stability theory, the overall closed-loop system is shown to be stable. The designed controller not only can control the uncertain chaotic system to a desired state, but also the control action is smooth without chattering. Simulation examples are presented to further illustrate the advantage of the proposed method. © 2012 Springer Science+Business Media B.V.
Ma K.,Dalian University |
Ruan Z.,Key Laboratory of Microbial Resources |
Ruan Z.,Chinese Academy of Agricultural Sciences
Bioresource Technology | Year: 2015
Aiming at improving the efficiency of transferring corn stover into sugars, an efficient lignocellulolytic enzyme system was developed and investigated by co-cultivation of the Coprinus comatus with Trichoderma reesei in a single bioreactor. The results showed that the lignocellulolytic enzyme activities of the co-culture exceeded that of the monoculture, suggesting synergistic interaction between two fungi. The highest laccase activity from the co-culture was 2.6-fold increase over that of the C. comatus monoculture and reached a peak 3. days earlier. The maximum delignification obtained was 66.5% and about 82% of the original polysaccharides were converted into fermentable sugars by simultaneous bio-delignification and saccharification process. Correlation analysis showed that sugar yields were directly proportional to the lignin degradation. Our results suggested that co-fungi cultivation was a valuable technique for corn stover bioconversion, which could produce high efficiency of lignocellulolytic enzyme system as a cheaper alternative to commercial enzymes for industrial utilization. © 2014 Elsevier Ltd.
Zhang X.,Dalian University
Pancreas | Year: 2016
OBJECTIVE: This paper aimed to assess the physiological effects of p53 on glucose homeostasis in vivo. METHODS: A recombinant adenoviral p53 (rAd-p53) vector was administered to insulin-resistant diabetic mice. Intraperitoneal glucose tolerance test was performed in all groups of mice. Changes in fasting blood glucose, serum triglycerides, C-peptide, and insulin concentrations in treated and untreated mice were measured. Analyses of the target genes related to glucose metabolism were performed. RESULTS: Treatment with the rAd-p53 improved glucose control in a dose- and time-dependent manner and lowered significantly the fasting blood glucose, the serum triglycerides, and improved tolerance test of glucose as compared to control. Lowered blood glucose was associated with up-regulation of genes in the glycogenesis pathways, and down-regulation of genes in the gluconeogenesis pathways in the liver. Overexpressions of GLUT2, GK, PPAR-γ, and insulin receptor precursor were also observed in the liver and the pancreas of treated animals. CONCLUSIONS: Activation of p53-mediated glucose metabolism led to insulin-like antidiabetic effect in the mouse model especially by changing hepatic insulin sensitivity in the diabetic mouse model. Copyright © 2016 Wolters Kluwer Health, Inc. All rights reserved.
Feng M.,Dalian University
Advanced Materials Research | Year: 2014
Based on fuzzy decision theory, multi objective fuzzy optimization is done for three dynamic model scheme of self-anchored cable-stayed suspension bridge. Combining the fuzzy decision method with engineering practice and using two comparison theory solves the problem of quantifying the qualitative indexes. Comparison results show that it is more reasonable to place viscous dampers between main tower and girder, with longitudinal displacement on mid-span of girder on the same time. This method can provide a reference for structure selection in practical conceptual design phase. © (2014) Trans Tech Publications, Switzerland.
Dong X.Y.,Dalian University
Advanced Materials Research | Year: 2014
In this study, we investigated the effect of DBD plasma at atmospheric pressure on membrane permeability, potential membrane and cytoplasmic free calcium concentration in Saccharomyces cerevisiae. S. cerevisiae cells were treated with DBD plasma for 0, 1, 2, 3, 4 and 5 min and then subjected to various analyses before the commencement of fermentation or at the middle (9 h) and end (21 h) stages of fermentation. The results show that compared to non-treated cells, cells treated with plasma for 2-5 min show significant increase in membrane potential, while cells treated for 2-4 min show significant increase in membrane permeability prior to fermentation. Plasma-treated cells also show increased cytoplasmic free Ca2+ that depends on plasma treatment time, with the highest increase, 35%, observed for 5-min treatment time. However, at the middle (9 h) and end (21 h) stages of fermentation, these changes become insignificant compared to the control. © (2014) Trans Tech Publications, Switzerland.
Li L.,Dalian University
Signal, Image and Video Processing | Year: 2015
This paper presents a novel method for joint parameter estimation of multiple targets for bistatic multiple-input multiple-output radar system in impulsive noise. Firstly, a new signal array model is constructed according to a 3-D motion characteristics of target in impulsive noise environment. Secondly, Doppler frequency parameters are jointly estimated by peak searching of a fractional lower-order ambiguity function based on fractional Fourier transform (FLOS-FAF) and a dechirping method. Furthermore, two modified algorithms are proposed for the estimation of direction-of-departure and direction-of-arrival, including the MUSIC algorithm based on the fractional lower-order ambiguity function (FF-MUSIC) and the ESPRIT algorithm based on the fractional lower-order ambiguity function (FF-ESPRIT) in the fractional Fourier transform domain. Simulation results are presented to verify the effectiveness of the proposed method. © 2014, Springer-Verlag London.
Du X.,Dalian University
Advanced Materials Research | Year: 2013
The differences of instantaneous frequency (IF) characteristics between the defect echo and the noise can be sed to detect defect and suppress noise for ultrasonic testing signal. Therefore, the IF is one of the important instantaneous parameters of ultrasonic testing signal. To estimate the IF of ultrasonic testing signals more effectively, the peak of time-frequency representation (TFR) from matching pursuits (MP) decomposition is proposed. The performances of IF estimators are compared on the simulated signals at different signal-to-noise ratio (SNR) and the real ultrasonic testing signal. The simulation results present that the proposed method can estimate accurate IF at different SNR. © (2013) Trans Tech Publications, Switzerland.
Sun C.,Dalian University |
Wang X.,Dalian University
Plasmonics | Year: 2015
We report on an investigation into the light trapping efficiency for structures of thin film silicon solar cells, with silver nanoparticle arrays at both front and rear surfaces of the cells. The light trapping efficiencies of the structures are quantified by the weighted mean values of the photons absorbed by the silicon layer, over a wavelength range of 400 to 1100 nm. The weighted mean values are calculated under various combinations of the structural parameters for the silver nanoparticle arrays. The results show that efficient light trapping structures of the solar cells can be achieved by carefully choosing the structural parameters of the metal arrays. This great light absorption by the cell is attributed to the effects induced by the surface plasmon excitation of the metal particles. Based on the analyses, we also suggest that the method employed in this work may be a useful tool to probe other similar structures of the solar cells with metal nanoparticle arrays. © 2015, Springer Science+Business Media New York.
Li L.,Dalian University
Applied Mechanics and Materials | Year: 2014
The problem of Cramer-Rao bound for parameter estimation in norrowband bistatic Multiple-Input Multiple-Output (MIMO) radar system is considered. In this paper, we propose a new narrowband signal model to accurately estimate parameter from a moving target. The Cramer-Rao bound for target parameter estimation is derived and computed in closed form which shows that the optimal performance is achieved. Target location and parameter estimation performances are evaluated and studied theoretically and via simulations. © (2014) Trans Tech Publications, Switzerland.