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Search Results: 1 - 10 of 92320 matches for " Yang Xiao-Xuan "
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The Market Reaction To Stock Splits Used as Dividends  [PDF]
Yang Xiao-Xuan
Technology and Investment (TI) , 2013, DOI: 10.4236/ti.2013.41B009
Abstract: This paper investigates the market reaction to stock splits based on China’s A share companies between 2007 to 2010. I find significant positive abnormal returns around the announcement date (especially before the announcement date) as well as four to six days before the execution date of China stock splits. I also observe significant negative abnormal returns just around the execution date. The above phenomenon is relatively stable even if the selection of samples and empirical models may vary, but the degree of this phenomenon might change overtime. The cross sectional regression of the abnormal returns for the announcement date shows that the phenomenon is sensitive to the split ratio and the market, and it is not sensitive to industry, company size and cash dividends. Therefore, combining with the empirical data i have constructed a high Sharpe ratio short selling investment strategy around the execution date. Then, the article further discusses the operability of the investment strategy and its stability over time.
miR-424在人脂肪来源间充质干细胞成骨分化中的调控作用
Regulatory effect of miR-424 on the osteogenic differentiation of human adipose derived mesenchymal stem cells

余章,黄雅琢,杨潇璇,肖彩雯
YU Zhang
, HUANG Ya-zhuo, YANG Xiao-xuan, XIAO Cai-wen

- , 2016, DOI: 10.3969/j.issn.1674-8115.2016.07.003
Abstract: 目的 探讨miR-424在人脂肪来源间充质干细胞(hASC)成骨分化中的表达及miR-424对hASC体外成骨分化的生物学作用。方法 qPCR检测miR-424在hASC成骨分化不同阶段的表达水平。通过慢病毒颗粒在体外感染hASC,使miR-424过表达或抑制其表达,进行Western blotting、细胞免疫荧光试验及碱性磷酸酶(ALP)和茜素红(ARS)染色试验,研究miR-424对骨形态发生蛋白2(BMP-2)及成骨诱导液诱导hASC成骨分化过程的影响。预测miR-424的靶基因,并利用qPCR及Western blotting验证。结果 qPCR结果显示miR-424在hASC的表达量随着成骨诱导时间延长逐渐下降(P<0.05)。在BMP-2诱导下,过表达组的碱性磷酸酶(ALP)和骨桥蛋白(OPN)蛋白水平均下降,而抑制组的表达增加(P<0.05)。细胞免疫荧光显示,过表达miR-424的细胞骨唾液酸蛋白(BSP)阳性率显著下降(P<0.05)。ALP和ARS染色显示,过表达组ALP活性降低,钙盐沉积下降,而抑制组ALP活性升高,矿化能力增强。过表达miR-424能降低hASC中Smad5的mRNA和蛋白水平,而抑制miR-424则使其水平升高(P<0.05)。结论 miR-424在hASC成骨分化中表达下调,其在hASC体外成骨分化过程中起抑制作用。
: Objective To explore the expression and biological effect of miR-424 during osteogenic differentiation of human adipose derived mesenchymal stem cells (hASC). Methods The expressions of miR-424 at different stages of osteogenic differentiation of hASC were detected with real-time PCR. miR-424 was over-expressed or miR-424 expression was inhibited via infection of hASCs with lentivirus particles in vitro. Western blotting, immunocytochemistry, and alkaline phosphatase (ALP) staining and alizarin red (ARS) staining were performed. The effects of miR-424 on osteogenic differentiation of hASCs induced with BMP-2 and osteogenic differentiation medium were investigated. The target gene of miR-424 was predicted and was verified with qPCR and Western blotting. Results The results of qPCR revealed that the expression of miR-424 declined with the time of osteogenic differentiation (P<0.05). The protein levels of ALP and osteopontin (OPN) decreased in the over-expression group and increased in the inhibition group with the induction of bone morphogenetic protein 2(BMP-2) (P<0.05). The results of immunocytochemistry revealed that over-expression of miR-424 significantly reduced the cell positive rate of bone sialoprotein (BSP)(P<0.05). ALP and ARS staining showed that the activity of ALP and capacity of mineralization in the over-expression group decreased, while the activity of ALP and capacity of mineralization increased in the inhibition group. Over-expression of miR-424 could decrease the mRNA and protein expression levels of Smad5 in hASCs and inhibition of miR-424 could increase the mRNA and protein expression levels of Smad5 (P<0.05). Conclusion The expression of miR-424 declines during the osteogenic differentiation of hASCs and miR-424 inhibits the osteogenic differentiation of hASCs
Isolation and identification of the causative agent and histopathology observation of white-spots disease in internal organs of Larimichthys crocea
大黄鱼(Larimichthys crocea)内脏白点病的病原分离和组织病理学观察

QIU Yang-Yu,ZHENG Lei,MAO Zhi-Juan,CHEN Xiao-Xuan,
邱杨玉
,郑磊,毛芝娟,陈孝煊

微生物学通报 , 2012,
Abstract: Objective] In order to find the pathogenic bacteria of white-spots disease in internal organs of Larimichthys crocea. Methods] Using the method of isolation and identification of the causative agent in combination with 16S rRNA sequencing to find the pathogenic bacteria.Besides it was determined by artificial infection. The tissue of diceased fish were pathologically analyzed by paraffin histological section techniques. Results] The bacterium Pseudomonas putida was responsible for the disease. Affected fish showed obvious inflammation and cell deformation or disintegration of the liver, kidney and spleen. Conclusion] The conducted study was necessary in order to reveal the reason for the high mortality of cultured yellow croaker in the Xiangshan bay. Furthermore, the results of this study can help to early recognize such disease outbreaks, hence preventing drastic economic losses in the future.
NHD: System Based on Separation between Storage and Computation
基于存储和计算分离的NHD系统

LIU Hai-yang,MENG Xiao-xuan,XU Lu,KU Yi-nan,
刘海洋
,孟晓烜,许鲁,库依楠

计算机应用研究 , 2007,
Abstract: This article introduced a novel computer system,named NHD(Network Hard Disk),which was based on the theory model of the separation between computation and storage resources.In order to meet different applications' requirements,the NHD system utilized a specialized hardware equipment installed on the side of client to combine those two resources on demand.This newly reconstructed computing environment has advantages of dynamics,individuation and easy management.
A Drug Screening Method Based on the Autophagy Pathway and Studies of the Mechanism of Evodiamine against Influenza A Virus
Jian-Ping Dai, Wei-Zhong Li, Xiang-Feng Zhao, Ge-Fei Wang, Jia-Cai Yang, Lin Zhang, Xiao-Xuan Chen, Yan-Xuan Xu, Kang-Sheng Li
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042706
Abstract: In this research, we have established a drug screening method based on the autophagy signal pathway using the bimolecular fluorescence complementation - fluorescence resonance energy transfer (BiFC-FRET) technique to develop novel anti-influenza A virus (IAV) drugs. We selected Evodia rutaecarpa Benth out of 83 examples of traditional Chinese medicine and explored the mechanisms of evodiamine, the major active component of Evodia rutaecarpa Benth, on anti-IAV activity. Our results showed that evodiamine could significantly inhibit IAV replication, as determined by a plaque inhibition assay, an IAV vRNA promoter luciferase reporter assay and the Sulforhodamine B method using cytopathic effect (CPE) reduction. Additionally, evodiamine could significantly inhibit the accumulation of LC3-II and p62, and the dot-like aggregation of EGFP-LC3. This compound also inhibited the formation of the Atg5-Atg12/Atg16 heterotrimer, the expressions of Atg5, Atg7 and Atg12, and the cytokine release of TNF-α, IL-1β, IL-6 and IL-8 after IAV infection. Evodiamine inhibited IAV-induced autophagy was also dependent on its action on the AMPK/TSC2/mTOR signal pathway. In conclusion, we have established a new drug screening method, and selected evodiamine as a promising anti-IAV compound.
Variation of functional bacteria during start-up and operation of partial nitrification process
短程硝化启动运行中功能菌群变化研究

CHEN Xiao-Xuan,LIU Chun,YANG Jing-Liang,ZHANG Run,YANG Hui-Na,
陈晓轩
,刘春,杨景亮,张润,杨辉娜

微生物学通报 , 2012,
Abstract: Objective] Partial nitrification-anammox is considered as the shortest?process for biological nitrogen removal and partial nitrification is the important part of this process. Methods] The variation of functional bacteria during start-up and stable operation of partial nitrification process was investigated in a SBR bioreactor in this study. Results] The results indicated that ammonia-oxidizing bacteria (AOB) population was expanded significantly and nitrite-oxidizing bacteria (NOB) population was inhibited when DO concentration was controlled lower than 1 mg/L and ammonia loading of the influent increased gradually. As a result, start-up and stable operation of partial nitrification process was realized. When ammonia volumetric loading of the influent was 0.055 kg/(m3·d), the average ammonia removal volumetric loading and sludge loading were 0.043 kg/(m3·d) and 0.16?kg/(kg·d), respectively. In addition, the average nitrite accumulation rate was 83.4% at this time. AOB population density and relative abundance increased from 4.5×104 CFU/mL to 1.5×107CFU/mL and from 0.18% to 7.25%, respectively, during start-up and stable operation of partial nitrification process. At the same time, NOB population density and relative abundance decreased from 2.0×105 CFU/mL to 1.5×104 CFU/mL?and from 5.51% to 2.14%, respectively. Conclusion] The expansion of AOB population was responsible for realization of partial nitrification and ammonia removal. High ammonia concentration and loading?also caused the activity inhibition of partial nitrification.
Optimization Study on k Value of K-means Algorithm
K-means 算法中的k 值优化问题研究

YANG Shan-lin,LI Yong-sen,HU Xiao-xuan,PAN Ruo-yu,
杨善林
,李永森,胡笑旋,潘若愚

系统工程理论与实践 , 2006,
Abstract: 在空间聚类中,最佳聚类数K求解的关键是构造合适的聚类有效性函数.典型K-平均算法中的聚类数K必须是事先给定的确定值,然而,实际中K很难被精确地确定,使得该算法对一些实际问题无效.文章提出距离代价函数作为最佳聚类数的有效性检验函数,建立了相应的数学模型,并据此设计了一种新的K值优化算法.同时,给出了K值最优解KOPT及其上界KMAX的条件,在理论上证明了经验规则KMAX≤N的合理性,实例结果进一步验证了新方法的有效性.
RESOLUTION IMPROVEMENT OF RAMAN DEPTH PROFILE
提高深度剖析拉曼光谱的纵向分辨能力

XU Xiao-Xuan LIN Hai-Bo WU Zhong-Chen YANG Yan-Yong,ZHU Jian ZHANG Cun-Zhou ZHANG Guang-Yin,
徐晓轩
,杨延勇

红外与毫米波学报 , 2003,
Abstract: The resolution ability of confocal Raman microscopy on the depth direction was theoretically discussed, and the response equation of confocal Raman microscopy on the depth direction was obtained by using properly approximation. A simply convolution model of thin sample (just like semiconductor film) was designed. Based on the confocal Raman spectrometer and depth profile method, the character of crystalline phase in laser recrystallized poly-Si thin films was researched. By using the deconvolution algorithm, the higher resolution structure distribution on depth direction of the film was obtained , and nano-crystalline phase was discovered locating only in the middle of thin film.
Drug Screening for Autophagy Inhibitors Based on the Dissociation of Beclin1-Bcl2 Complex Using BiFC Technique and Mechanism of Eugenol on Anti-Influenza A Virus Activity
Jian-Ping Dai, Xiang-Feng Zhao, Jun Zeng, Qian-Ying Wan, Jia-Cai Yang, Wei-Zhong Li, Xiao-Xuan Chen, Ge-Fei Wang, Kang-Sheng Li
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061026
Abstract: Autophagy is involved in many human diseases, such as cancer, cardiovascular disease and virus infection, including human immunodeficiency virus (HIV), hepatitis C virus (HCV), influenza A virus (IAV) and coxsackievirus B3/B4 (CVB3/B4), so a drug screening model targeting autophagy may be very useful for the therapy of these diseases. In our study, we established a drug screening model based on the inhibition of the dissociation of Beclin1-Bcl2 heterodimer, an important negative regulator of autophagy, using bimolecular fluorescence complementation (BiFC) technique for developing novel autophagy inhibitors and anti-IAV agents. From 86 examples of traditional Chinese medicines, we found Syzygium aromaticum L. had the best activity. We then determined the anti-autophagy and anti-IAV activity of eugenol, the major active compound of Syzygium aromaticum L., and explored its mechanism of action. Eugenol could inhibit autophagy and IAV replication, inhibited the activation of ERK, p38MAPK and IKK/NF-κB signal pathways and antagonized the effects of the activators of these pathways. Eugenol also ameliorated the oxidative stress and inhibited the expressions of autophagic genes. We speculated that the mechanism underlying might be that eugenol inhibited the oxidative stress and the activation of ERK1/2, p38MAPK and IKK/NF-κB pathways, subsequently inhibited the dissociation of Beclin1-Bcl2 heterodimer and autophagy, and finally impaired IAV replication. These results might conversely display the reasonableness of the design of our screening model. In conclusion, we have established a drug screening model for developing novel autophagy inhibitor, and find eugenol as a promising inhibitor for autophagy and IAV infection.
Toxocara Seroprevalence among Clinically Healthy Individuals, Pregnant Women and Psychiatric Patients and Associated Risk Factors in Shandong Province, Eastern China
Wei Cong equal contributor,Xiao-Xuan Zhang equal contributor,Na Zhou,Chang-Zheng Yu,Jia Chen,Xiang-Yang Wang,Bing Li,Ai-Dong Qian,Xing-Quan Zhu
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0003082
Abstract: Background Toxocarosis is a widespread zoonosis caused by the ascarid nematodes Toxocara canis and Toxocara cati, which primarily infect dogs and cats, respectively. Most human infections with Toxocara are asymptomatic; however, some infected individuals may develop a serious illness and even death. Nevertheless, epidemiological knowledge regarding the prevalence and risks associated with Toxocara infection is limited in China. Therefore, we performed a cross-sectional pilot study and estimated the seroprevalence of Toxocara infection in humans in Shandong Province, eastern China for the first time, from June 2011 to July 2013, involving clinically healthy individuals, pregnant women and psychiatric patients, aiming to attract public attention to Toxocara infection. Methodology/Principle Findings Seroprevalence of Toxocara was determined using an enzyme-linked immunosorbent assay based on a cross-sectional study conducted in Qingdao and Weihai, Shandong Province, eastern China. Factors potentially associated with Toxocara infection were identified by logistic regression analysis. The overall Toxocara seroprevalence among the study population (n = 2866) was 12.25%, and a significantly higher seroprevalence in psychiatric patients (16.40%, 73/445) than that in clinically healthy individuals (13.07%, 187/1431) and pregnant women (9.19%, 91/990) was revealed. Univariate analyses suggested that keeping dogs at home (OR = 0.06, 95% CI 0.05–0.08, P<0.001), contact with cats and dogs (OR = 0.42, 95% CI 0.33–0.53, P<0.001) and exposure with soil (OR = 0.37, 95% CI 0.28–0.49, P<0.001) were risk factors associated with Toxocara infection. Conclusions/Significance The present study revealed, for the first time, that human infection with Toxocara is common in eastern China, posing a significant public health concern. Increasing human and dog populations, population movements and climate change all will serve to increase the importance of this zoonosis. Further studies under controlled conditions are necessary to define potential morbidity associated with Toxocara infection.
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