oalib

OALib Journal期刊

ISSN: 2333-9721

费用:99美元

投稿

时间不限

2018 ( 64 )

2017 ( 88 )

2016 ( 115 )

2015 ( 1365 )

自定义范围…

匹配条件: “Yuequn Wei” ,找到相关结果约48466条。
列表显示的所有文章,均可免费获取
第1页/共48466条
每页显示
The Threshold Effect of R and D Intensity on Enterprise Performance—Evidence from the GEM Listed Company  [PDF]
Yuequn Wei, Guiping Bao
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104534
Abstract:
This paper mainly adopts the panel data of listed company in GEM from 2012 to 2016, with the threshold panel model, Deeply studying the influence of R & D investment intensity on enterprise performance, and discovering that R&D intensity has a double threshold effect on enterprise performance. When the sustainable ability of research and development activities is lower than the first threshold value, R & D intensity has a significant negative impact on firm performance; when the sustainable capacity is between the first threshold value and the second threshold value, the intensity of R & D investment and enterprise financial performance was negatively correlated, and positively correlated with production performance; when the sustainable capacity of R & D activity exceeded second threshold value, R & D intensity has a significant positive impact on enterprise performance. Therefore, to improve the sustainability of R & D activities is an important way for enterprises to improve their performance.
Threshold Effects of R&D Intensity on Enterprise Performance from the Perspective of Scientific Research Achievements Transformation Ability  [PDF]
Yuequn Wei, Guiping Bao
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104667
Abstract:
Based on the listed company data of high-tech enterprise of manufacturing industry from year 2012 to 2016, this paper analyzed the no-linear effect of R&D intensity on firm performance with different ability of R&D achievements transformation. The empirical results show that the R&D input intensity has a double threshold effect on the capability of R&D achievement conversion. When the conversion ability of R&D achievement is lower than the first threshold value of 2.19%, the R&D input intensity significantly positively affects the enterprise performance; after more than 2.19%, the role of R&D input will decrease significantly and become less significant. When more than second threshold of 6.75%, R&D input intensity will significantly negatively affect enterprise performance; the relationship between R&D input intensity and firm performance has significant industry differences. Therefore, paying close attention to the nature of the industry and improving the transformation capability of scientific research achievements is an important measure for high-tech enterprises to improve their R&D effect, seize the market and improve their performance.
The Influence of Angiotensin Converting Enzyme and Angiotensinogen Gene Polymorphisms on Hypertrophic Cardiomyopathy
Rong Luo, Xiaoping Li, Yuequn Wang, Yongqing Li, Yun Deng, Yongqi Wan, Zhigang Jiang, Wei Hua, Xiushan Wu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0077030
Abstract: Some studies have reported that angiotensin converting enzyme (ACE) and angiotensinogen (AGT) genes have been associated with hypertrophic cardiomyopathy (HCM). However, there have been inconsonant results among different studies. To clarify the influence of ACE and AGT on HCM, a systemic review and meta-analysis of case-control studies were performed. The following databases were searched to indentify related studies: PubMed database, the Embase database, the Cochrane Central Register of Controlled Trials database, China National Knowledge Information database, and Chinese Scientific and Technological Journal database. Search terms included “hypertrophic cardiomyopathy”, “angiotensin converting enzyme” (ACE) or “ACE” and “polymorphism or mutation”. For the association of AGT M235T polymorphism and HCM, “angiotensin converting enzyme” or “ACE” was replaced with “angiotensinogen”. A total of seventeen studies were included in our review. For the association of ACE I/D polymorphism and HCM, eleven literatures were included in the meta-analysis on association of penetrance and genotype. Similarly, six case-control studies were included in the meta-analysis for AGT M235T. For ACE I/D polymorphism, the comparison of DI/II genotype vs DD genotype was performed in the present meta-analysis. The OR was 0.73 (95% CI: 0.527, 0.998, P = 0.049, power = 94%, alpha = 0.05) after the study which deviated from Hardy-Weinberg Equilibrium was excluded, indicating that the ACE I/D gene polymorphism might be associated with HCM. The AGT M235T polymorphism did not significantly affect the risk of HCM. In addition, ACE I/D gene polymorphism did not significantly influence the interventricular septal thickness in HCM patients. In conclusion, the ACE I/D polymorphism might be associated with the risk of HCM.
CTLH: A Novel Domain with A Typical "U" Shape Architecture
Weiqi Zeng,Yuequn Wang,Wuzhou Yuan,Yun Deng
Research Journal of Biological Sciences , 2006,
Abstract: We described here a novel domain, CTLH, which can be found in proteins of most already-researched species currently. The domain, consisted of 58 amino acid residues, is not often-conserved in sequence (but has 5 regularly-arranged leucines that are highly conserved). However, its 3D architecture conserves greatly with a typical `U` shape (alpha helix+beta turn+alpha helix). Although the function of CTLH domain remains unknown, related studies aiming at this domain suggest it participates in the regulation of certain signaling pathways like MAPK, and is involved in some living activities of cells such as protein degradation and mitosis.
Influence of different illuminations with xenon or microwave sulfur lamp on jointing and tillering of wheat
Qilin Chen,Yuequn Liu,Xinjian Yu,Jinxing Chen,Jun Weng,Chunhe Xu
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9316
Abstract: The emission of microwave sulfur lamp is mainly composed of visible light. The sulfur lamp, producing little infrared radiation, has high efficiency, long duration of illumination and less energy consumption. In order to probe the agricultural application of the lamp, experiments were carried out with wheat (cv. Yangmai 158) to emphatically study illuminating effects of xenon or sulfur lamp on tillering, jointing and net photosynthetic rate during tillering and jointing periods. Results indicated that there is almost no difference in net photosynthetic rate of wheat leaves growing under different lamps. Xenon lamp significantly advanced the time of jointing, decreased number of tillers, number of total leaves per plant and leaf size, as well as inhibited root growth. In contrast with xenon lamp, sulfur lamp evidently delays the time of heading and grain maturation, increased number of heads per plant, head length, total number of grains per plant, head weight and total grain weight per plant, accordingly significantly increased yield per plant. Strong infrared radiation might be the main cause to influence jointing and tillering. The development characteristics of wheat under sulfur lamp were much similar with those in natural condition.
CTLH: A Novel Domain with A Typical "U" Shape Architecture
Weiqi Zeng,Yuequn Wang,Wuzhou Yuan,Yun Deng,Yongqing Li,Chuanbing Zhu,Mingyao Liu,Xiushan Wu
Research Journal of Biological Sciences , 2012,
Abstract: We described here a novel domain, CTLH, which can be found in proteins of most already-researched species currently. The domain, consisted of 58 amino acid residues, is not often-conserved in sequence (but has 5 regularly-arranged leucines that are highly conserved). However, its 3D architecture conserves greatly with a typical U shape (alpha helix+beta turn+alpha helix). Although the function of CTLH domain remains unknown, related studies aiming at this domain suggest it participates in the regulation of certain signaling pathways like MAPK, and is involved in some living activities of cells such as protein degradation and mitosis.
THE CHANGES OF NITRATE REDUCTASE (NR) ACTIVITY AND PROTEIN CONTENT OF CHINESE PANAX GINSENG LEAVES AND ROOTS CULTIVATED UNDER DIFFERENT LIGHT QUALITIES
不同光质下栽培人参硝酸还原酶(NR)活性和蛋白质含量的变化

Sun Fei Cao Yuequn,
孙非
,曹悦群,刘立侠,唐树延

生物物理学报 , 1993,
Abstract: The effects of light qualities on the Nitrate Reductase (NR) activity and protein content of Chinese Panax ginseng were investigated. The results are as follow:The NR activity in leaves and roots was the highest at preblossom stage and declined as the roots matured and the leaves senesced. The NR activity in leaves was higher than that in roots. The soluble protein and the total protein nitrogen contents in leaves were reduced from the highest value at preblossom stage to the lowest at maturation stage, while that in roots were quite the reverse.The NR activity, soluble protein and total protein nitrogen contents in the leaves and roots cultivated were the highest under blue light membrane; and relatively lower under red or green light membranes. It is possible to increase NR activity and soluble protein content in leaves and roots by increasing the blue light component in red or red-green light membranes.The above results showed that in Ginseng cultivation increase of blue light is beneficial to the nitrogen metabolism.
Characterization of Mushy Zone Properties of AZ6x Magnesium Alloys
AZ6X镁合金的糊状区特性表征

MA Yuequn,LIANG Songmao,CHEN Rongshi,HAN Enhou,
马跃群
,梁松茂,陈荣石,韩恩厚

金属学报 , 2007,
Abstract: Mushy zone properties of AZ6x alloys were characterized and analysed by using cooling curve thermal analysis method and continuous torque measurement technique. The results show that Tn1 (first characteristic temperature of primary crystal nucleation), Tn2 (second characteristic temperature of primary crystal nucleation) and Tch (temperature of dendritic coherency) decrease with the increasing of zinc content, and the temperature difference of (Tn1-Tn2) grows slowly while the temperature difference of (Tn2-Tch) almost remains constant; The results also show that the fs-cc (solid fraction of dendritic coherency) of AZ6x alloys is about 0.27~0.35 while AM60 and AZ66 alloys having higher fs-ch and alloys with 2~5wt% zinc content having lower fs-ch and AZ62 alloy having the lowest fs-ch; The results also show that Tpk (temperature of dendritic packing) decrease with the increasing of zinc content, and the solid fraction at Tpk decreases with the increasing of zinc content, and the mushy zone strength at Tpk increases first and then decreases with the increasing of zinc content while mushy zone strength of alloys with 2~5wt% zinc content having relatively slow increasing speed. the results obtained by cooling curve thermal analysis method and continuous torque measurement technique are accordant to each other.
Receptor binding specificity and origin of 2009 H1N1 pandemic influenza virus  [PDF]
Wei Hu
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.33030
Abstract: Recently, a genetic variant of 2009 H1N1 has become the predominant virus circulating in the southern hemisphere, particularly Australia and New Zealand, and in Singapore during the winter of 2010. It was associated with several vaccine breakthroughs and fatal cases. We analyzed three reported mutations D94N, N125D, and V250A in the HA protein of this genetic variant. It appeared that the reason for D94N and V250A to occur in pairs was to maintain the HA binding to human type receptor, so the virus could replicate in humans efficiently. Guided by this interpretation, we discovered a new mutation V30A that could compensate for N125D as V250A did for D94N. We demonstrated that the presence of amino acids 30A and 125N in HA enhanced the binding to human type receptor, while 30V and 125D favored the receptors of avian type and of A/South Carolina/1/18 (H1N1). Furthermore, a combination of 94D, 125D, and 250V made the primary binding preference similar to that of A/South Carolina/1/18 (H1N1) and a combination of 94N, 125D, and 250A resulted in the primary binding affinity for avian type receptor, which clearly differed from that of A/California/07/2009 (H1N1), a strain used in the vaccine for 2009 H1N1. We also re-examined the origin of 2009 H1N1 to refine our knowledge of this important issue. Although the NP, PA, PB1, and PB2 of 2009 H1N1 were closest to North American swine H3N2 in sequence identity, their interaction patterns were closest to swine H1N1 in North America.
Highly conserved domains in hemagglutinin of influenza viruses characterizing dual receptor binding  [PDF]
Wei Hu
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.29123
Abstract: The hemagglutinin (HA) of influenza viruses in itiates virus infection by binding receptors on host cells. Human influenza viruses preferenti ally bind to receptors with α2,6 linkages to gala ctose, avian viruses prefer receptors with α2,3 linkages to galactose, and swine viruses favor both types of receptors. The pandemic H1N1 2009 remains a global health concern in 2010. The novel 2009 H1N1 influenza virus has its ge netic components from avian, human, and sw ine viruses. Its pandemic nature is characterized clearly by its dual binding to the α2,3 as well as α2,6 receptors, because the seasonal human H1N1 virus only binds to the α2,6 receptor. In pr evious studies, the informational spectrum me thod (ISM), a bioinformatics method, was appli ed to uncover highly conserved regions in the HA protein associated with the primary receptor binding preference in various subtypes. In the present study, we extended the previous work by discovering multiple domains in HA associa ted with the secondary receptor binding prefer ence in various subtypes, thus characterizing the distinct dual binding nature of these viruses. The domains discovered in the HA proteins were mapped to the 3D homology model of HA, which could be utilized as therapeutic and diag nostic targets for the prevention and treatment of influenza infection.
第1页/共48466条
每页显示


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.