检索结果-南通市图书馆

Density Functional Theory Study on Interaction between Catechin and Thymine

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2012年第6期25卷 642-648,I0003页

作者： wan-fei cai Yan Zheng Lai-cai Li An-min Tian Departement of Chemistry and Material Science Sichuan Normal University Chengdu 510065China Departement of Chemistry Sichuan University Chengdu 510054 China

The interacting patterns and mechanism of the catechin and thymine have been investigated with the density functional theory Becke＇s three-parameter nonlocal exchange functional and the Lee, Yang, and Parr nonlocal correlation functional （B3LYP） method by 6-31＋G＊ basis set. Thirteen stable structures for the catechin-thymine complexes have been found which form two hydrogen bonds at least. The vibrational frequencies are also studied at the same level to analyze these complexes. The results indicated that catechin interacted with thynfine by three different hydrogen bonds as N-H…O, C-H…O, O-H…O and the complexes are mainly stabilized by the hydrogen bonding interactions. Theories of atoms in molecules and natural bond orbital have been adopted to investigate the hydrogen bonds involved in all systems. The interaction energies of all complexes have been corrected for basis set superposition error, which are from -18.15 k J/mol to -32.99 kJ/mol. The results showed that the hydrogen bonding contribute to the interaction energies dominantly. The corresponding bonds stretching motions in all complexes are red-shifted relative to that of the inonomer, which is in agreement with experimental results.

关键词： Density functional theory Thymine Hydrogen bond Catechin

NONLINEAR NUMERICAL ANALYSIS OF A FLEXIBLE ROTOR EQUIPPED WITH SQUEEZE COUPLE STRESS FLUID FILM JOURNAL BEARINGS

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2007年第4期20卷 309-316页

作者： cai-wan Chang-Jian Her-Terng Yau Department of Mechanical and Automation Engineering I-Shou University Kaohsiung County 840 Taiwan China Department of Electrical Engineering Far-East College Tainan County 744 Taiwan China

This study performs a dynamic analysis of a rotor supported by two squeeze couple stress fluid film journal bearings with nonlinear suspension. The numerical results show that the stability of the system varies with the non-dimensional speed ratios and the dimensionless parameter l＊. It is found that the system is more stable with higher dimensionless parameter l＊. Thus it can conclude that the rotor-bearing system lubricated with the couple stress fluid is more stable than that with the conventional Newtonian fluid. The modeling results thus obtained by using the method proposed in this paper can be used to predict the stability of the rotor-bearing system and the undesirable behavior of the rotor and bearing center can be avoided.

关键词： couple stress fluid rotor-bearing system bifurcation chaos squeeze

Qili Qiangxin, a compound herbal medicine formula, alleviates hypoxia-reoxygenation-induced apoptotic and autophagic cell death via suppression of ROS/AMPK/mTOR pathway in vitro

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Medicine 2022年第4期20卷 365-375页

作者： cai-lian Fan wan-jun cai Meng-nan Ye Miao Chen Yi Dai Department of Cardiology the First Affiliated Hospital of Jinan UniversityJinan UniversityGuangzhou 510632Guangdong ProvinceChina College of Pharmacy Jinan UniversityGuangzhou 510632Guangdong ProvinceChina

Objective: Qili Qiangxin(QLQX), a compound herbal medicine formula, is used effectively to treat congestive heart failure in China. However, the molecular mechanisms of the cardioprotective effect are still unclear. This study explores the cardioprotective effect and mechanism of QLQX using the hypoxiareoxygenation(H/R)-induced myocardial injury ***: The main chemical constituents of QLQX were analyzed using high-performance liquid chromatography-evaporative light-scattering detection. The model of H/R-induced myocardial injury in H9c2 cells was developed to simulate myocardial ischemia–reperfusion injury. Apoptosis, autophagy,and generation of reactive oxygen species(ROS) were measured to assess the protective effect of QLQX. Proteins related to autophagy, apoptosis and signalling pathways were detected using Western ***: Apoptosis, autophagy and the excessive production of ROS induced by H/R were significantly reduced after treating the H9c2 cells with QLQX. QLQX treatment at concentrations of 50 and 250 μg/mL caused significant reduction in the levels of LC3Ⅱ and p62 degradation(P < 0.05), and also suppressed the AMPK/mTOR signalling pathway. Furthermore, the AMPK inhibitor Compound C(at 0.5 μmol/L),and QLQX(250 μg/mL) significantly inhibited H/R-induced autophagy and apoptosis(P < 0.01), while AICAR(an AMPK activator, at 0.5 mmol/L) increased cardiomyocyte apoptosis and autophagy and abolished the anti-apoptotic effect of QLQX. Similar phenomena were also observed on the expressions of apoptotic and autophagic proteins, demonstrating that QLQX reduced the apoptosis and autophagy in the H/R-induced injury model via inhibiting the AMPK/mTOR pathway. Moreover, ROS scavenger,N-Acetyl-L-cysteine(NAC, at 2.5 mmol/L), significantly reduced H/R-triggered cell apoptosis and autophagy(P < 0.01). Meanwhile, NAC treatment down-regulated the ratio of phosphorylation of AMPK/AMPK(P < 0.01), which showed a similar effect to ***: QLQX plays a

关键词： Herbal medicine Qili Qiangxin formula Hypoxia–reoxygenation Reactive oxygen species Autophagy Apoptosis AMPK/mTOR pathway

A method for analyzing on-line video images of crystallization at high-solid concentrations

在线全文

学校读者我要写书评

暂无评论

Particuology 2008年第1期6卷 9-15页

作者： Jian wan cai Y. Ma Xue Z. wang Institute of Particle Science and Engineering School of Process Environmental and Materials Engineering University of Leeds Leeds LS2 9JT UK

Recent research has demonstrated that on-line video imaging is a very promising technique for monitoring crystallization processes. The bottleneck in applying the technique for real-time closed-loop control is considered as image analysis that needs to be robust, fast and able to handle varied image qualities due to temporal variations of operating conditions such as mixing and solid concentrations. Image analysis at highsolid concentrations turns out to be extremely challenging because crystals tend to overlap or attach to each other and the boundaries between the crystals are usually ambiguous. This paper presents an image segmentation algorithm that can effectively deal with images taken at high-solid concentrations. The method segments crystals attached to each other along the mostly related concave points on the contours of crystal blocks. The detailed procedure is introduced with application to crystallization of L-glutamic acid in a hot-stage reactor.

关键词： Crystallization High-solid concentrations Image processing Multi-scale segmentation Watershed segmentation Crystal size distribution

Total Routhian Surface Calculations on Hf Isotopes

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2008年第8期50卷 459-462页

作者： YU Shao-Ying LI Yan-Xia SHEN cai-wan College of Science Huzhou Teachers College Huzhou 313000 China College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua 321000 China Institute of Theoretical Physics the Chinese Academy of Sciences Beijing 100080 China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000China

The two-dimensional total routhian surface calculations have been carried out to stud）, the triaxial superdeformed structure of a neutron-rich nucleus ^173 Hf firstly. In particular the effects of the rotational frequency ω and pairing-energy gap parameter A are discussed in detail in the course of shaping its triaxial superdeformation; additionally the neutron-shell correction energy is analyzed with emphasis in the confirmed triaxial superdeformed nucleus ^173Hf. Finally, more systematical results have been investigated for some confirmed superdeformed nuclei experimentally and a few predicted triaxial superdeformed nuclei theoretically with quadropole deformation ε2 ≈0.4 and triaxial deformation γ≈20° or 30° in the Z = 72 region.

关键词： triaxial superdeformed nucleus total routhian surface

An explanation of the elliptic flow difference between proton and anti-proton from the UrQMD model with hadron potentials

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2016年第3期59卷 60-65页

作者： Qing Feng Li Yong Jia wang Xiao Bao wang cai wan Shen School of Science Huzhou University

The time evolution of both proton and anti-proton v2 flows from Au＋Au collisions at √SNN=7.7 GeV are examined by using both pure cascade and mean-field potential versions of the UrQMD model. Due to a stronger repulsion at the early stage introduced by the repulsive potentials and hence much less annihilation probabilities, anti-protons are frozen out earlier with smaller v2 values. Therefore, the experimental data of anti-proton v2 as well as the flow difference between proton and anti-proton can be reasonably described with the potential version of UrQMD.

关键词： elliptic flow difference UrQMD mean field potential annihilation process

An Experimental Study of Partial Melting of Metafelsic Rocks:Constraints on the Feature of Anatectic Melts and the Origin of Garnets in Collisional Orogens

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2022年第3期33卷 753-769页

作者： Xu Luo Qiong-Xia Xia Yong-Fei Zheng wan-cai Li CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Center of Excellence in Comparative Planetology Chinese Academy of Sciences(CAS)Hefei 230026China Department of Earth Environmental and Planetary SciencesCase Western Reserve UniversityCleveland OH 44106USA

Crustal anatexis in continental subduction zones has great bearing on chemical differentiation of the continental crust at convergent plate *** was experimentally investigated for ultrahigh-pressure(UHP)metafelsic rocks at 0.5-3.0 GPa and 650-900℃.The results show that partial melting begins at about 750℃ when pressure drops from 3.0 to 2.0 GPa,corresponding to decompressional exhumation of the deeply subducted continental *** the pressure further decreases to 1.0 GPa,the partial melting degree reaches the maximum of~25%at 900℃.Partial melts produced in these experiments are rich in silica and alkali,and poor in iron,manganese and *** the degree of partial melting increases,the composition of partial melts gradually converges toward homogeneous *** the absence of free water,the partial melting of metafelsic rocks were triggered by the breakdown of hydrous *** low temperatures of~750℃at 1.0-2.0 GPa,phengite dehydration melting occurs at first,giving rise to small amounts of felsic melts and peritectic *** the temperature rises up to 850-900℃,biotite begins to break down and gives rise to large amounts of felsic melts and peritectic minerals such as garnet,K-feldspar and *** is noted that peritectic garnet is much different from anatectic garnet crystallized from anatectic melts and metamorphic garnet formed through metamorphic dehydration reaction under subsolidus *** peritectic garnet is characterized not only by anhedral shapes with many multiphase crystal inclusions but also by compositions poor in spessartine and grossular but rich in almandine and *** the other hand,the anatectic garnets are characterized not only by euhedral shapes with few inclusions but also by compositions rich in grossular and spessartine but poor in almandine and *** observations provide experimental constraints on the origin of garnets in UHP metamorphic rocks,which have great bearing on understanding of

关键词： collisional orogen partial melting experimental petrology metafelsic rocks garnet melts

Retrospective analysis of influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 patients

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第31期9卷 9481-9490页

作者： Jia Zeng Xiao-Xia Qi wan-wan cai Ya-Ping Pan Yi Xie Department of Aviation Disease Naval Medical Center of PLAShanghai 200052China No.1 Department of Infection Optical Valley Campus of Hubei Maternal and Child Health Care HospitalWuhan 430073Hubei ProvinceChina Department of Traditional Chinese Medicine Naval Medical Center of PLAShanghai 200052China Department of Naval Diving Medicine Naval Medical Center of PLAShanghai 200052China Traditional Chinese Medicine Naval Medical Center of PLAShanghai 200052China Department of Hepatobiliary Surgery Naval Medical Center of PLAShanghai 200052China

BACKGROUND The novel coronavirus disease 2019(COVID-19)has spread widely around the world with strong infectivity,rapid mutation and a high mortality *** ventilation has been included in the Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia(Trial Version 8)as an important treatment for severe and critical COVID-19 patients,but its clinical efficacy in COVID-19 patients is ***,it is necessary to study the influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 *** The aim of this study was to determine the influencing factors on the efficacy of mechanical ventilation in severe and critical COVID-19 *** A total of 27 severe and critical COVID-19 patients were enrolled in this study and treated with mechanical ventilation at the Optical Valley Campus of Hubei Maternal and Child Health Care Hospital(Wuhan,Hubei Province)from February 20,2020 to April 5,*** to the final treatment outcomes,the patients were divided into the“effective group”and“death group.”The clinical data of the two groups,such as the treatment process and final outcome,were retrospectively analyzed in order to determine the specific curative effects on the two groups and the reasons for the differences in such curative effects,as well as to explore the factors related to *** This study enrolled 27 severe and critical COVID-19 patients,including 17 males(63.0%)and 10 females(37.0%).Their ages were 74.41±11.73-years-old,and 19 patients(70.4%)were over *** COVID-19 patients over 70-yearsold who were treated with mechanical ventilation died in 14 cases(82.4%);thus,this was the peak age.A total of 17 patients died of basic disease,16 of whom had more than two basic *** basic diseases were hypertension,diabetes,and cardiovascular and cerebrovascular *** the same time,13 patients(76.5%)died from an abnormal increase in blood *** them,eight had dia

关键词： COVID-19 Mechanical ventilation Efficacy Factors Prognosis

Microwave-assisted One-pot Three-component Polymerization of Alkynes, Aldehydes and Amines toward Amino-functionalized Optoelectronic Polymers

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2017年第2期35卷 269-281页

作者： tao jia nan-nan zheng wan-qing cai jie zhang lei ying 黄飞 yong cao Institute of Polymer Optoeleetronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou 510640 China

We present a microwave-assisted one-pot polymerization with three-components of alkynes, aldehydes and amines for the synthesis of new amino-functionalized optoelectronic polymers. The polymerization of diynes （la-lc）, dialdehydes （2a and 2b） and dibenzylamine catalyzed by InC13 was carried out smoothly within 1 h under microwave radiation, yielding four soluble polymers with high molecular weights. The resulting polymers P1 and P2 could be easily dissolved in alcohol and thus utilized as the cathode interlayer for polymer solar cells （PSCs）. Compared with the control device, the PSCs with P1 and P2 as the cathode interlayer and PTB7-Th：PC71BM as the photoactive layer exhibited significantly higher power conversion efficiencies （PCEs） of 9.49% and 9.16%, respectively. These results suggest that this polycoupling reaction is an efficient approach to construct three-component polymers for the practical applications.

关键词： One-pot three-component polymerization Polymer solar cells Cathode interlayer