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Kim D.-C.,Research South, Inc. | Ku S.-W.,Daegu Haany University | Bae J.-S.,Kyungpook National University
BMB Reports | Year: 2012

Curcumin, a polyphenol responsible for the yellow color of the curry spice turmeric, possesses antiinflammatory, antiproliferative and antiangiogenic activities. However, anticoagulant activities of curcumin have not been studied. Here, the anticoagulant properties of curcumin and its derivative (bisdemethoxycurcumin, BDMC) were determined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT) as well as cell-based thrombin and activated factor X (FXa) generation activities. Data showed that curcumin and BDMC prolonged aPTT and PT significantly and inhibited thrombin and FXa activities. They inhibited the generation of thrombin or FXa. In accordance with these anticoagulant activities, curcumin and BDMC showed anticoagulant effect in vivo. Surprisingly, these anticoagulant effects of curcumin were better than those of BDMC indicating that methoxy group in curcumin positively regulated anticoagulant function of curcumin. Therefore, these results suggest that curcumin and BDMC possess antithrombotic activities and daily consumption of the curry spice turmeric might help maintain anticoagulant status.

Agency: National Aeronautics and Space Administration | Branch: | Program: STTR | Phase: Phase II | Award Amount: 600.00K | Year: 2011

The innovation of our Phase II STTR program is to develop and provide to NASA automatic mesh generation software for the simulation of fluid flows using Reynolds-Averaged Navier-Stokes codes. As a result of the successful Phase I work, these new tools are now capable of generating high-quality, highly-stretched (anisotropic) meshes in boundary layer regions and transition smoothly to inviscid flow regions, even in an adaptive context. The significance is that our method has the ability to generate a boundary layer mesh while keeping intact the previous adaptation procedures from non viscous simulations. This leads to a natural coupling between boundary layer mesh generation and anisotropic mesh adaptation. All of the Phase I objectives were met and all tasks were completed successfully. The Phase II project will include improvements in surface remeshing, coding for optimal speed and increased robustness of the solvers, adding a mesh optimization module, providing a link to general CAD packages, include unsteady coupling where the boundary layer mesh refinement evolves in time, conduct further validation and verification on NASA models by running flow cases with our solver, documenting the project, and delivering the new meshing software to NASA.

Agency: National Aeronautics and Space Administration | Branch: | Program: STTR | Phase: Phase I | Award Amount: 100.00K | Year: 2010

This proposal offers to provide NASA with an automatic mesh generator for the simulation of aerodynamic flows using Reynolds-Averages Navier-Stokes (RANS) models. The tools will be capable of generating high-quality, highly-stretched (anisotropic) grids in boundary layer regions and transition smoothly to inviscid flow regions even in an adaptive context. The objective of the work is to offer a unified view for generating quality and robust RANS meshes coupled naturally with anisotropic mesh adaptation. Our innovation is to view the anisotropic mesh generation within the Riemannian metric framework which thus far has been used exclusively in anisotropic mesh adaptation. Using the metric-based framework allows much easier handling of the large mesh size ratios involved in the computation, whereas traditional methods use the Euclidean framework to compute distance and volume. This innovative view to generate these meshes makes the entire procedure more generic and much more robust. The emphasis is being put on deriving a completely automatic process to generate quality and robust anisotropic meshes. Our existing and proven software package will be modified to include these innovative methods. A NASA test case will be computed for validation of the methods. The software will be delivered in Phase II.

Clement A.F.,University College London | Hillson S.W.,University College London | Aiello L.C.,Research South, Inc.
Journal of Human Evolution | Year: 2012

The Anterior Dental Loading Hypothesis states that the unique Neanderthal facial and dental anatomy was an adaptive response to the regular application of heavy forces resulting from both the masticatory and cultural use of the anterior teeth. Heavy anterior tooth wear frequently observed in Neanderthal specimens is cited as a main source of evidence for heavy forces being applied to these teeth. From this, it might be predicted that the wear shown on the anterior teeth of Neanderthals would greatly exceed that of the posterior teeth and that this differential would be greater than in other hominins with different facial morphologies.In this paper, a new method of examining tooth wear patterns is used to test these predictions in a large assemblage of Late Pleistocene hominins and a group of recent hunter-gatherers from Igloolik, Canada. The results show that all Late Pleistocene hominins, including Neanderthals, had heavily worn anterior teeth relative to their posterior teeth but, contrary to expectations, this was more pronounced in the modern humans than in the Neanderthals. The Igloolik Inuit showed heavier anterior tooth wear relative to their posterior teeth than any Late Pleistocene hominins. There was, however, a characteristic Neanderthal pattern in which wear was more evenly spread between anterior teeth than in modern humans. Overall, the evidence presented here suggests that all Late Pleistocene hominins habitually applied heavy forces between their anterior teeth and that Neanderthals were not exceptional in this regard. These results therefore does not support the Anterior Dental Loading Hypothesis. © 2012 Elsevier Ltd.

Kim M.-K.,Kongju National University | Kim S.,Research South, Inc.
Atmospheric Environment | Year: 2011

The quantitative values of the urban warming effect over city stations in the Korean peninsula were estimated by using the warming mode of Empirical Orthogonal Function (EOF) analysis of 55 years of temperature data, from 1954 to 2008. The estimated amount of urban warming was verified by applying the multiple linear regression equation with two independent variables: the rate of population growth and the total population. Through the multiple linear regression equation, we obtained a significance level of 0.05% and a coefficient of determination of 0.60. This means that it is somewhat liable to the estimated effects of urbanization, in spite of the settings of some supposition. The cities that show great warming due to urbanization are Daegu, Pohang, Seoul, and Incheon, which show values of about 1.35, 1.17, 1.16, and 1.10 °C, respectively. The areas that showed urban warming less than 0.2 °C are Chupungnyeong and Mokpo. On average, the total temperature increase over South Korea was about 1.37 °C; the amount of increase caused by the greenhouse effect is approximately 0.60 °C, and the amount caused by urban warming is approximately 0.77 °C. © 2011 Elsevier Ltd.

Kim D.,Korea Research Institute of Standards and Science | Han J.,Research South, Inc. | Choi Y.,Jeonju University
Analytical and Bioanalytical Chemistry | Year: 2013

A method using on-line solid-phase microextraction (SPME) on a carbowax-templated fiber followed by liquid chromatography (LC) with ultraviolet (UV) detection was developed for the determination of triclosan in environmental water samples. Along with triclosan, other selected phenolic compounds, bisphenol A, and acidic pharmaceuticals were studied. Previous SPME/LC or stir-bar sorptive extraction/LC-UV for polar analytes showed lack of sensitivity. In this study, the calculated octanol-water distribution coefficient (log D) values of the target analytes at different pH values were used to estimate polarity of the analytes. The lack of sensitivity observed in earlier studies is identified as a lack of desorption by strong polar-polar interactions between analyte and solid-phase. Calculated log D values were useful to understand or predict the interaction between analyte and solid phase. Under the optimized conditions, the method detection limit of selected analytes by using on-line SPME-LC-UV method ranged from 5 to 33 ng L-1, except for very polar 3-chlorophenol and 2,4-dichlorophenol which was obscured in wastewater samples by an interfering substance. This level of detection represented a remarkable improvement over the conventional existing methods. The on-line SPME-LC-UV method, which did not require derivatization of analytes, was applied to the determination of TCS including phenolic compounds and acidic pharmaceuticals in tap water and river water and municipal wastewater samples. [Figure not available: see fulltext.] © 2012 Springer-Verlag Berlin Heidelberg.

Chen X.,Research South, Inc. | D'Souza R.,Chonbuk National University | Hong S.-T.,Research South, Inc.
Protein and Cell | Year: 2013

Brain and the gastrointestinal (GI) tract are intimately connected to form a bidirectional neurohumoral communication system. The communication between gut and brain, knows as the gut-brain axis, is so well established that the functional status of gut is always related to the condition of brain. The researches on the gut-brain axis were traditionally focused on the psychological status affecting the function of the GI tract. However, recent evidences showed that gut microbiota communicates with the brain via the gut-brain axis to modulate brain development and behavioral phenotypes. These recent findings on the new role of gut microbiota in the gut-brain axis implicate that gut microbiota could associate with brain functions as well as neurological diseases via the gut-brain axis. To elucidate the role of gut microbiota in the gut-brain axis, precise identification of the composition of microbes constituting gut microbiota is an essential step. However, identification of microbes constituting gut microbiota has been the main technological challenge currently due to massive amount of intestinal microbes and the difficulties in culture of gut microbes. Current methods for identification of microbes constituting gut microbiota are dependent on omics analysis methods by using advanced high tech equipment. Here, we review the association of gut microbiota with the gut-brain axis, including the pros and cons of the current high throughput methods for identification of microbes constituting gut microbiota to elucidate the role of gut microbiota in the gut-brain axis. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Lihh W.-S.,Research South, Inc.
IEEE Transactions on Antennas and Propagation | Year: 2010

When asymptotically describing the wave fields on the denser side of a planar permittivity interface, the canonical head-wave fields of the tangential-magnetic (TM) set show discrepancies with the full-wave fields. This paper derives the correction fields that supplement the canonical TM head-wave fields, by taking into account the proximity between the head-wave branch point and an extraneous pole in the wavenumber domain. The validity of the correction is demonstrated in the time domain by comparing the waveforms of a corrected field and the full-wave field, for various ratios of permittivity and at various locations of observation. Consideration is also given to the case of a conducting medium. © 2010 IEEE.

Kim D.S.,Research South, Inc.
Human Vaccines and Immunotherapeutics | Year: 2013

The 13th annual World Vaccine Congress held in Washington DC (April 16-18, 2013) sponsored a plenary and a session focused on cancer vaccine. The cancer vaccine session consisted of three presentations: "Cancer vaccine landscape overview" by Dr Jeffrey Schlom, a Chief of the Laboratory of Tumor Immunology and Biology, Center for Cancer Research (CCR), National Cancer Institute (NCI); "Immune-system based cancer vaccines" by Dr Geert-Jan Boons, the Complex Carbohydrate Research Center of the University of Georgia; "Peptide vaccine for malignant gliomas" by Dr Robert Fenstermaker, Chair of the Department of Neurosurgery at Roswell Park Cancer Institute. As Dr Jay Berzofsky, Chief of the new Vaccine Branch (CCR, NCI) pointed out in the plenary, not only the quantity but also the quality (avidity and longevity)1 of T cell activation is important for the clearance of cancer cells, each of the presented cancer vaccine platforms will first be reviewed by its immunological design to promote the activation of T cells. Then, the benefits of combined cancer vaccines therapy with conventional cancer therapy will be discussed with a mathematical model from NCI prostate cancer trials. © 2013 Landes Bioscience.

Lee S.,Research South, Inc. | Park J.,Seoul National University of Science and Technology | Choi S.,Seoul National University of Science and Technology
IEEE Transactions on Power Electronics | Year: 2011

In this paper, a new active-clamped three-phase current-fed push-pull dc-dc converter is proposed for high-power applications where low-voltage high-current input sources such as fuel cells are used. The proposed converter has the following features: active clamping of the transient surge voltage caused by transformer leakage inductances, natural zero-voltage switching turn-on of main switches using energy stored in transformer leakage inductor, small current rating and zero-voltage and zero-current switching of clamp switches, no additional start-up circuitry for soft starting due to the operating duty cycle range between 0 and 1, and zero-current switching turn-off of rectifier diodes leading to negligible voltage surge associated with the diode reverse recovery. A comparative study along with loss analysis is performed. Experimental results from 5-kW laboratory prototypes of the proposed active-clamped converter and the passive-clamped converter are provided. © 2011 IEEE.

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