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Search Results: 1 - 10 of 78880 matches for " Chen Zang "
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Association of Body Mass Index with Semen Quality and Sexual Hormone Levels among Men in Intrauterine Insemination  [PDF]
Erhong Zhang, Hui Zhang, Zhijun Zang, Bin Zhang, Jun Chen
Health (Health) , 2014, DOI: 10.4236/health.2014.614218
Abstract: Background: The available evidence on the role of obesity and BMI on male infertility has been controversial or inconclusive to some extent. Objectives: To investigate the role of BMI on semen quality and hormone levels in men received intrauterine insemination. Material and Methods: A total of 390 males seeking artificial insemination in our department were recruited. BMI, blood pressure and semen parameters were assessed. Morning blood sample was taken for serum levels of testosterone (T), prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E2). Results: Subjects were divided into four groups according to BMI. There was no significant difference among groups in any of semen parameters and serum levels of FSH, LH, PRL and E2. Obese and overweight men were found having lower serum levels of T and higher levels of E2/T ratio than those of normal and underweight men. BMI was not found to be associated with semen parameters. Conclusion: This study has not found evidence of an association between BMI and semen parameters, but obesity has a negative effect on serum testosterone levels.
Growth and characterization of large, high quality cubic diamond crystals
ChuanYi Zang,Ming Li,LunJian Chen
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5023-4
Abstract: High quality cubic diamond crystals were grown using the temperature gradient method at high pressure and high temperature (HPHT), in a new FeNi alloy as solvent. The crystals were grown at relatively low temperatures suitable for the growth of {100} faces. An increase in the radial growth rate, and inhibition of the axial growth caused the growth of large, high quality cubic diamond single crystals at high growth rates. For example, over 33 h, the radial growth rate was 0.22 mm/h, while the axial growth rate was only 0.08 mm/h; the growth rate by weight was also increased to 7.3 mg/h. The yellow color of our crystal samples was more uniform than samples from Sumitomo Corporation of Japan and Element Six Corp. The Raman FWHW of the 1332 cm 1 peak in our diamond sample was smaller than the Element Six Corp. sample, but larger than that of the Sumitomo Corp. sample. The nitrogen content of our diamond samples was 240 ppm, which was much higher than the Sumitomo and Element Six samples because of the higher growth rate of our diamond samples.
Magic wavelengths for lattice trapped Rubidium four-level active optical clock
Xiaorun Zang,Tonggang Zhang,Jingbiao Chen
Physics , 2012, DOI: 10.1088/0256-307X/29/9/090601
Abstract: After pumped from $5s_{1/2}$ ground state to $6p_{1/2}$ state, the population inversion between $6s_{1/2}$ and $5p_{1/2,3/2}$ will be established for Rubidium four-level active optical clock. In this paper, we calculate AC Stark shift due to lattice trapping laser which dominates the frequency shift of clock transition in lattice trapped Rubidium four-level active optical clock. Several magic wavelengths are found that can form desired optical lattice trapping potential. By choosing a proper intensity and linewidth of trapping laser, the fractional frequency uncertainty of clock transition due to AC Stark shift of trapping laser, is estimated to be below 10^-18
Coloring Digraphs with Forbidden Cycles
Zhibin Chen,Jie Ma,Wenan Zang
Mathematics , 2014,
Abstract: Let $k$ and $r$ be two integers with $k \ge 2$ and $k\ge r \ge 1$. In this paper we show that (1) if a strongly connected digraph $D$ contains no directed cycle of length $1$ modulo $k$, then $D$ is $k$-colorable; and (2) if a digraph $D$ contains no directed cycle of length $r$ modulo $k$, then $D$ can be vertex-colored with $k$ colors so that each color class induces an acyclic subdigraph in $D$. The first result gives an affirmative answer to a question posed by Tuza in 1992, and the second implies the following strong form of a conjecture of Diwan, Kenkre and Vishwanathan: If an undirected graph $G$ contains no cycle of length $r$ modulo $k$, then $G$ is $k$-colorable if $r\ne 2$ and $(k+1)$-colorable otherwise. Our results also strengthen several classical theorems on graph coloring proved by Bondy, Erd\H{o}s and Hajnal, Gallai and Roy, Gy\'arf\'as, etc.
A Study of Myocardial Ischemia Model Induced by Left Coronary Artery Ligation in Rats  [PDF]
Hailin Wang, Chunyu Cao, Lianqiang Hui, Ting Liu, Yanli Wang, Shuangrong Gao, Yi Zhang, Ran Hao, Chun Li, Chen Zang
World Journal of Cardiovascular Diseases (WJCD) , 2016, DOI: 10.4236/wjcd.2016.65014
Abstract: Objective: Coronary artery was ligated to study the characteristics of myocardial ischemia in rats. Methods: The left anterior descending artery was ligated to establish the rat model of acute myocardial ischemia. All animals were divided into normal control group, sham operation group and model group. 1, 2 and 4 weeks after modeling, ECG (II lead) was recorded, the weight of whole heart and left ventricle were recorded and organ indexes were calculated; myocardial infarct size was determined by TTC; CK, CK-MB, LDH, AST contents of serum were detected; cardiac function was determined by left ventricular intubation via carotid artery and left ventricular was taken to perform pathological observation. Results: 1 week after modeling, compared with the sham operation group, the ECG and heart function index of rats model had significant change, but the myocardial enzymes did not change significantly; 4 weeks after modeling, the ECG and cardiac function of animal models had a recovery trend, but the myocardial enzymes, including CK, CK-MB, LDH, AST, were significantly increased; 1 week after modeling, the left ventricular indexes of model rats were increased; the infarct size was about 30%, myocardial cell necrosis and granulation tissue hyperplasia could be observed in infarction area; with the modeling time extended, from 2 to 4 weeks, the left ventricular and heart indexes of model group were significantly increased; the infarct size was relatively constant, left ventricular became thickly, and fibrous or granulation tissue was significantly proliferated in infarction area under microscope. Conclusion: The indexes of myocardial ischemia induced by coronary artery ligation in rats are different at different time points. The results suggest that the time point should be selected to observe the anti-myocardial ischemia effect of the subjects from different aspects.
Hepatoprotective Activity of Yigan Mingmu Oral Liquid against Isoniazid/Rifampicin-Induced Liver Injuries in Rats  [PDF]
Yuxin Chen, Qigui Mo, Baibo Xie, Bingxin Ma, Xinyu Zang, Gao Zhou, Linyou Cheng, James Hua Zhou, Youwei Wang
Chinese Medicine (CM) , 2018, DOI: 10.4236/cm.2018.94010
Abstract:

Background: To explore the hepatoprotective effect of Yigan mingmu oral liquid (YGMM) on isoniazid-rifampicin induced liver injury in rats. Methods: Total 38 SD rats were randomly divided into 6 groups including control group, model group, silymarin positive control group, and three YGMM treatment groups. Model group was administered intragastrically with INH (100 mg/kg) and RIF (100 mg/kg) for 14 days. Silymarin group and YGMM treatment groups were administered intragastrically with silymarin (100 mg/kg) and different doses of YGMM (1, 2.5, 5 mg/kg) 2 hours before INH and RIF administration from day 4 to day 14.Results: Rats were sacrificed 16 hours after the last day treatment to determine the activities of serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP), as well as total bilirubin (TB) content. Oxidative stress was evaluated by measuring total superoxide dismutase (T-SOD) and malondialdehyde (MDA) levels. Histopathological changes in liver tissues were observed under an optical microscope by using hematoxylin and eosin staining. The mice?in model groups showed significantly (p < 0.05) increased levels in AST, ALT, ALP, TB and MDA compared to their control groups; and showed significantly (p < 0.05) decreased level in T-SOD. These changes were significantly (p < 0.05) reversed by the YGMM treatments in a dose-dependent manner. Hepatic pathological changes were attenuated or even reversed by silymarin or YGMM treatments. Conclusions: YGMM has a good hepatoprotective activity on isoniazid-rifampicin induced liver

Selectivity by host plants affects the distribution of arbuscular mycorrhizal fungi: evidence from ITS rDNA sequence metadata
Haishui Yang, Yanyan Zang, Yongge Yuan, Jianjun Tang, Xin Chen
BMC Evolutionary Biology , 2012, DOI: 10.1186/1471-2148-12-50
Abstract: We defined 305 ITS virtual taxa (ITS-VTs) among all sequences of the Glomeromycota by using a comprehensive maximum likelihood phylogenetic analysis. Each host taxonomic order averaged about 53% specific ITS-VTs, and approximately 60% of the ITS-VTs were host specific. Those ITS-VTs with wide host range showed wide geographic distribution. Most ITS-VTs occurred in only one type of host functional group. The distributions of most ITS-VTs were limited across ecosystem, across continent, across biogeographical realm, and across climatic zone. Non-metric multidimensional scaling analysis (NMDS) showed that AMF community composition differed among functional groups of hosts, and among ecosystem, continent, biogeographical realm, and climatic zone. The Mantel test showed that AMF community composition was significantly correlated with plant community composition among ecosystem, among continent, among biogeographical realm, and among climatic zone. The structural equation modeling (SEM) showed that the effects of ecosystem, continent, biogeographical realm, and climatic zone were mainly indirect on AMF distribution, but plant had strongly direct effects on AMF.The distribution of AMF as indicated by ITS rDNA sequences showed a pattern of high endemism at large scales. This pattern indicates high specificity of AMF for host at different scales (plant taxonomic order and functional group) and high selectivity from host plants for AMF. The effects of ecosystemic, biogeographical, continental and climatic factors on AMF distribution might be mediated by host plants.Arbuscular mycorrhizal fungi (AMF) are widespread in terrestrial ecosystems and form obligatory symbiotic relationships with most land plants [1]. These symbioses are not host specific but are to some extent host-preferential [1]. AMF may have a biogeographical distribution partially because of their soil-borne life form, host preference, and limited dispersal resulting from geographic isolation [2]. Increasingly,
Mechanism of diamond-to-graphite transformation at diamond-stable conditions
ChuangYi Zang,XiaoZhou Chen,Qiang Hu,HongAn Ma,XiaoPeng Jia
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0401-2
Abstract: The diamond-to-graphite transformation at diamond-stable conditions is studied by temperature gradient method (TGM) under high pressure and high temperature (HPHT), although it is unreasonable from the view of thermodynamic considerations. It is found that, at diamond-stable conditions, for example, at 5.5 GPa and 1550 K, with fine diamond grits as carbon source and NiMnCo alloy as metal solvent assisted, not only large diamond crystals, but metastable regrown graphite crystals would be grown by layer growth mechanism, and the abundance of carbon source in the higher temperature region is indispensable for the presence of metastable regrown graphite crystals. From this transformation, it is concluded that, with metal solvent assisted, although the mechanism of crystal growth could be understood by the macro-mechanism of solubility difference between diamond and graphite in metal solvents, from the point of micro-mechanism, the minimum growth units for diamond or graphite crystals should be at atomic level and unrelated to the kinds of carbon source (diamond or graphite), which could be accumulated free-selectively on the graphite with sp2п or diamond crystals with sp3 bond structure.
The Westerly Anomalies over the Tropical Pacific and Their Dynamical Effect on the ENSO Cycles during 1980-1994

Huang Ronghui,Zang Xiaoyun,Zhang Renhe,Chen Jilong,

大气科学进展 , 1998,
Abstract: In this paper, the zonal wind anomalies in the lower troposphere over the tropical Pacific during 1980-1994 are analyzed by using the observed data. The results show that during the formation of the 1982 / 83, 1986 / 87 and 1991/92 ENSO events, there were the larger westerly anomalies in the lower troposphere over the equatorial Pacific. Moreover, it is explained by using the correlation analyses that the westerly anomalies over the equatorial Pacific could cause the warm episodes of the equatorial central and eastern Pacific. A simple air-sea coupled model is used to discuss theoretically the dynamical effect of the observed westerly anomalies of wind stress near the sea surface of the equatorial Pacific on the ENSO cycle occurred in the period of 1981-1983. It is shown by using the theoretical calculations of the equatorial oceanic Kelvin wave and Rossby waves responding to the forcing of the observed anomalies of zonal wind stress near the sea surface of the equatorial Pacific that the westerly anomalies of wind stress near the sea surface of the equatorial Pacific make significant dynamical ef?fect on the ENSO cycles occurred in the period of 1982-1983.
Association between Interleukin-4 Receptor α Chain (IL4RA) I50V and Q551R Polymorphisms and Asthma Risk: An Update Meta-Analysis
Wei Nie, Yuansheng Zang, Jiquan Chen, Qingyu Xiu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069120
Abstract: Background The associations between the interleukin-4 receptor α chain (IL4RA) I50V and Q551R polymorphisms and asthma risk remained controversial. Methods We searched the Pubmed, Embase, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases for studies published before February 2013. The strengths of the associations were calculated using odds ratios (ORs) with 95% confidence intervals (CIs). Results A total of 50 studies were included in this meta-analysis. There was a significant association between the IL4RA I50V polymorphism and asthma risk in a dominant genetic model (OR = 1.13, 95% CI 1.04–1.23, P = 0.005). The IL4RA Q551R polymorphism was associated with a significantly elevated asthma risk in a recessive genetic model (OR = 1.46, 95% CI 1.22–1.75, P<0.0001). Subgroup analyses found that the IL4RA I50V polymorphism was significantly associated with asthma risk in Asians (OR = 1.72, 95% CI 1.31–2.25, P<0.0001), pediatric asthma risk (OR = 1.50, 95% CI 1.13–1.99, P = 0.005), and atopic asthma risk (OR = 1.88, 95% CI 1.27–2.79, P = 0.002). Conclusions The results of this meta-analysis suggested that the IL4RA I50V and Q551R polymorphisms may be risk factors for developing asthma.
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