Density functional theory studies of hydrogen bonding vibrations in sI gas hydrates

Abstract To analyze the vibrational modes of water and methane in structure I gas hydrates, we constructed a 178-atom supercell with two small cages of type 512 and six large cages of type 51262. We applied the density functional theory method to simulate the vibrational spectrum and normal modes of methane hydrates. In accord with our previous studies, we confirmed that two groups of hydrogen bond (H-bond) peaks (at around 291 and 210 cm−1) in the translational bands come from two kinds of intermolecular H-bond vibrational modes. This is the first investigation of H-bond vibrations in methane hydrates. The partial modes of CH4 were extracted. We found that the CH4 phonons in the translational region are below 180 cm−1 so that the influence of methane on the H-bond is insignificant. We proposed a new method to decompose gas hydrates via direct application of terahertz radiation to the H-bonds. Herein, we confirmed that CH4 molecules do not absorb this energy.</jats:p

Prognostic value of PDCD-1 and CTLA-4 in ovarian cancer patients

Therapeutic effectiveness of treatments for ovarian cancer is not optimal. PDCD-1 and CTLA-4 offers the potential as a prognostic marker in addition to being a target for therapy. To assess the prognostic roles of PDCD-1 and CTLA-4 Gene in ovarian cancer, we utilized the Kaplan Meier plotter, a biomarker assessment tool with large quantities of data. The relationship between PDCD-1 and overall survival (OS) as well as CTLA-4 and OS were presented using Hazard Ratio, 95% CI and logrank P value. Then gene expression level was compared using H-Test and U test. The results were as follows: PDCD-1 and CTLA-4 gene expressions among 1582 ovarian cancer patients were shown with median gene expression value as the cut-off. Expression of PDCD-1 and CTLA-4 did not differ with regard to stages and P53 gene mutation. But the expression of CTLA-4 was higher in endometrioid than in serous cancer patients. Different grades of both PDCD-1 and CTLA-4 had different mean values. Higher expression of the PDCD-1 was not significantly correlated with better OS with HR 0.88 (95% CI: 0.77-1.01, P=0.061) but higher CTLA-4 was associated with better survival with HR 0.84 (95% CI: 0.73-0.96, P=0.0099) on the transcriptome level. In conclusion, lower expression of CTLA-4, but not PDCD-1 predicts worse survival

Dynamic model for landsliding monitoring under rigid body assumption

Author name used in this publication: 朱建军Author name used in this publication: 丁晓利, DING Xiao-liAuthor name used in this publication: 陈永奇Journal title in Traditional Chinese: 中國有色金屬學會會刊 (英文版)2000-2001 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

视觉分散和视听分散对接受结肠镜检病人焦虑和接受性的影响

2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Broadband gradient impedance matching using an acoustic metamaterial for ultrasonic transducers

2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaVersion of RecordPublishe

Two-dimensional co-seismic surface displacements field of the Chi-Chi earthquake inferred from SAR image matching

Author name used in this publication: Xiao-li Ding2008-2009 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

The Exotic XYZ Charmonium-like Mesons

Charmonium, the spectroscopy of c\bar{c} mesons, has recently enjoyed a renaissance with the discovery of several missing states and a number of unexpected charmonium-like resonances. The discovery of these new states has been made possible by the extremely large data samples made available by the B-factories at the Stanford Linear Accelerator Center and at KEK in Japan, and at the CESR e^+e^- collider at Cornell. Conventional c\bar{c} states are well described by quark potential models. However, many of these newly discovered charmonium-like mesons do not seem to fit into the conventional c\bar{c} spectrum. There is growing evidence that at least some of these new states are exotic, i.e. new forms of hadronic matter such as mesonic-molecules, tetraquarks, and/or hybrid mesons. In this review we describe expectations for the properties of conventional charmonium states and the predictions for molecules, tetraquarks and hybrids and the various processes that can be used to produce them. We examine the evidence for the new candidate exotic mesons, possible explanations, and experimental measurements that might shed further light on the nature these states.Comment: 28 pages, 7 figures. Review for Ann Rev Nucl & Part Sc

Quantitative study of atmospheric effects in spaceborne InSAR measurements

Author name used in this publication: 李志伟Author name used in this publication: 丁晓利, DING Xiao-liAuthor name used in this publication: 朱建军Author name used in this publication: 邹峥嵘Journal title in Traditional Chinese: 中南工業大學學報 (英文版)2005-2006 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Green tea polyphenols ameliorate non-alcoholic fatty liver disease through upregulating AMPK activation in high fat fed Zucker fatty rats

© The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved. To investigate protective effects and molecular mechanisms of green tea polyphenols (GTP) on nonalcoholic fatty liver disease (NAFLD) in Zucker fatty (ZF) rats. METHODS Male ZF rats were fed a high-fat diet (HFD) for 2 wk then treated with GTP (200 mg/kg) or saline (5 mL/kg) for 8 wk, with Zucker lean rat as their control. At the end of experiment, serum and liver tissue were collected for measurement of metabolic parameters, alanine aminotransferase (ALT) and aspartate aminotransferase (AST), inflammatory cytokines and hepatic triglyceride and liver histology. Immunoblotting was used to detect phosphorylation of AMP-activated protein kinase (AMPK) acetyl-CoA carboxylase (ACC), and sterol regulatory element-binding protein 1c (SREBP1c). RESULTS Genetically obese ZF rats on a HFD presented with metabolic features of hepatic pathological changes comparable to human with NAFLD. GTP intervention decreased weight gain (10.1%, P = 0.052) and significantly lowered visceral fat (31.0%, P < 0.01). Compared with ZF-controls, GTP treatment significantly reduced fasting serum insulin, glucose and lipids levels. Reduction in serum ALT and AST levels (both P < 0.01) were observed in GTP-treated ZF rats. GTP treatment also attenuated the elevated TNFα and IL-6 in the circulation. The increased hepatic TG accumulation and cytoplasmic lipid droplet were attenuated by GTP treatment, associated with significantly increased expression of AMPK-Thr172 (P < 0.05) and phosphorylated ACC and SREBP1c (both P < 0.05), indicating diminished hepatic lipogenesis and triglycerides out flux from liver in GTP treated rats. CONCLUSION The protective effects of GTP against HFD-induced NAFLD in genetically obese ZF rats are positively correlated to reduction in hepatic lipogenesis through upregulating the AMPK pathway

Extraordinary strain hardening by gradient structure

Gradient structures have evolved over millions of years through natural selection and optimization in many biological systems such as bones and plant stems, where the structures change gradually from the surface to interior. The advantage of gradient structures is their maximization of physical and mechanical performance while minimizing material cost. Here we report that the gradient structure in engineering materials such as metals renders a unique extra strain hardening, which leads to high ductility. The grain-size gradient under uniaxial tension induces a macroscopic strain gradient and converts the applied uniaxial stress to multiaxial stresses due to the evolution of incompatible deformation along the gradient depth. Thereby the accumulation and interaction of dislocations are promoted, resulting in an extra strain hardening and an obvious strain hardening rate up-turn. Such extraordinary strain hardening, which is inherent to gradient structures and does not exist in homogeneous materials, provides a hitherto unknown strategy to develop strong and ductile materials by architecting heterogeneous nanostructures.</p