16 research outputs found
Empirical Study on the Market Reflection of Senior Managers’ Shares Reduction of Listed Companies on GEM
2010年11月1日,创业板首批28家上市公司迎来股权解禁之日。自此,创业板上市公司高管(包括董事、监事和高级管理人员)减持拉开了序幕,并且减持之风愈演愈烈,在2011年3月、5月、11月先后迎来高管减持高峰。根据深圳证券交易所公开披露数据的统计结果显示,创业板上市公司高管在13个月内减持规模超过30亿元,而高管增持规模仅有200万元左右。对于刚刚成立两年多的创业板块,上市公司股权解禁后的疯狂减持行为究竟对股票市场产生了何种影响以及市场反应如何,这是一个值得关注和探索的问题。 本文从现代企业的委托代理问题和信息不对称问题出发,分析了高管减持的股票价格反应机制,并以创业板上市公司高管减持事件为...The restricted shares of 28 first-batch GEM listed companies began to circulate on the secondary market in November 1, 2010. Since then, senior managers, including directors, supervisors and managers, arose the wave of selling shares, and got more and more intensive. Later, the peak of shares reduction came up one by one in March, May and November of 2011. According to the disclosure of Shenzhen S...学位:管理学硕士院系专业:管理学院会计系_会计学学号:1752009115101
乳腺癌病人血清HER-2/neu检测及其临床意义
【目的】本研究分析晚期乳腺癌患者血清HER-2/neu的水平与预后的关系,并探讨其临床意义。【方法】酶联免疫法(ELISA)检测94例晚期乳腺癌患者血清HER-2/neu的浓度.分析血清与组织中HER-2/neu表达的相关性,并分析其与患者预后的关系。【结果】94例晚期乳腺癌患者就诊时的血清HER-2/neu浓度为0.34-275.25μg/L(平均浓度为23.69μg/L)。血清HER-2/neu浓度的高低与化疗的有效性、疾病进展时间的长短无关。晚期乳腺癌患者的血清HER-2/neu浓度与肿瘤组织中HER-2/neu表达强阳性是一致的。【结论】血清HER-2/neu尚不能确立为独立的预后指标,需要更多的病例进行分析
不同强度深蹲对高水平男子篮球运动员纵跳能力影响研究
纵跳能力是以快速力量为主导的影响最终运动成绩的重要因素,纵跳能力不仅能够影响篮球运动员的投篮命中率、争抢篮板球以及盖帽能力,还能够在关键时候提高团队士气,从而间接影响球队最终成绩。科学界研究发现激活后增强效应(Post - activation Potentiation,PAP)有可能通过赛前准备来提高运动员在比赛中的具体表现,但是对于诱导强度并不明确。经研究表明高水平运动员的实验效果较为明显,故此文旨在探讨不同强度抗阻深蹲刺激以诱导激活后增强效应对于高水平篮球运动员纵跳能力的短期影响及其差异,为将此方法合理运用到训练和比赛实践中提供理论参考。</jats:p
磺化酞菁铝修饰氨基功能化磁性材料及其光敏化降解双酚A
采用溶剂热法制备氨基功能化Fe_3O_4磁性材料(NH_2@nFe_3O_4),通过浸渍法将磺化酞菁铝(AlPcS)负载于NH_2@nFe_3O_4。材料的傅立叶红外、漫反射、X射线衍射、扫描电镜、透射电镜、振动磁强计等表征表明:AlPcS主要通过静电作用与NH_2@nFe_3O_4结合,AlPcS-NH_2@nFe_3O_4平均粒径为127 nm,饱和磁化强度为75.3 emu·g-1。在可见光和空气作用下,该功能化磁性材料对降解弱碱性水溶液中环境内分泌干扰物双酚A(BPA)具有较高的光敏化活性。随着AlPcS负载量的增加活性呈先升高后下降的趋势,负载量为3.4%(质量分数)的复合材料性能最佳,反应60 min后,20.0 mg·L-1BPA降解率为96%;循环使用10次,BPA降解率仍保持93%以上。通过NaN3猝灭实验探讨了反应机理,证实1O2是光敏化过程中的主要活性物种
比较经颅超声造影和数字减影血管造影对大脑中动脉狭窄的诊断价值研究 Diagnostic Value of Transcranial Contrast-enhanced Ultrasound and Digital Subtraction Angiography for Middle Cerebral Artery Stenosis
【摘要】
目的 比较经颅超声造影(transcranial contrast-enhanced ultrasound,t-CEUS)和DSA在大脑中动脉(middle cerebral artery,MCA)狭窄性疾病中的诊断价值。
方法 收集2017年12月-2019年4月疑似MCA狭窄或闭塞的患者197例,记录其225条狭窄或闭塞的大脑中动脉的t-CEUS和DSA检查结果。根据MCA狭窄程度分为轻度狭窄(30%~50%),中度狭窄(50%~69%),重度狭窄(70%~99%)和闭塞(100%),以DSA为金标准,分析t-CEUS对轻、中和重度MCA狭窄的诊断价值。
结果 197例疑似MCA狭窄闭塞患者中,男132例,女65例,年龄43~72岁,平均(58.4±4.6)岁。经DSA确诊的狭窄和闭塞的225条MCA中,轻度狭窄16条,中度狭窄70条,重度狭窄121条,闭塞18条。t-CEUS诊断狭窄和闭塞的共224条MCA,其中,轻度狭窄18条,中度狭窄76条,重度狭窄112条,闭塞18条。t-CEUS和DSA诊断MCA狭窄和闭塞高度吻合(Kappa=0.91)。t-CEUS诊断轻度MCA狭窄的敏感度、特异度和准确度分别为80%、80%和91%;诊断中度MCA狭窄的敏感度、特异度和准确度分别为83%、93%和97%;诊断重度MCA狭窄的敏感度、特异度和准确度分别为83%、96%和96%。
结论 t-CEUS能够清楚地显示轻、中、重度MCA狭窄和闭塞,适用于MCA狭窄和闭塞类疾病患者的确诊,尤其是适用于不适合DSA检查的疑似MCA狭窄和闭塞患者。
【Abstract】
Objective To investigate the diagnostic value of transcranial contrast-enhanced ultrasound (t-CEUS) and digital subtraction angiography (DSA) for middle cerebral artery (MCA) stenosis or occlusion.
Methods A total of 197 patients with suspected MCA stenosis or occlusion from December 2017 to April 2019 were enrolled. A total of 225 stenostic or occluded MCAs were diagnosed by t-CEUS and DSA, according to the degree of MCA stenosis, the MCAs were divided into four groups: mild (30%-50%), moderate (50%-69%), severe (70%-99%) and occlusion (100%). Taking DSA diagnosis as the golden standard, the specificity, sensitivity, and accuracy of t-CEUS diagnosis were analyzed by comparing the results of ultrasound imaging.
Results Of all the 197 patients, 132 male and 65 female, with the average age (58.4+4.6) years and the range 43 to 72 years. Of 225 MCAs diagnosed by DSA, 16 MCAs were mild, 70 were moderate, 121 were severe, and 18 were occluded. Of 224 MCAs diagnosed by t-CEUS, 18 were mild, 76 were moderate, 112 were severe, and 18 were occluded. The diagnosis of MCA stenosis/occlusion using t-CEUS and DSA had a high consistency (Kappa=0.91). The sensitivity, specificity and accuracy of t-CEUS for the diagnosis of mild MCAs were 80%, 80%, and 91%, respectively; the sensitivity, specificity and accuracy of t-CEUS for the diagnosis of moderate MCAs were 83%, 93%, and 97%, respectively; the sensitivity, specificity and accuracy of t-CEUS for the diagnosis of severe MCA were 83%, 96%, and 96%, respectively.
Conclusions t-CEUS can clearly show mild, moderate and severe stenosis and occlusion in MCAs, and it is suitable for the diagnosis of patients with MCA stenosis and occlusion, especially for the patients with suspected MCA stenosis and who are not suitable for DSA
污染环境中细菌质粒的研究
本研究主要调查了受石油,农药和汞等污染的环境中好氧异养菌的种类及其所携带的质粒,并在恒化器中半连续培养和观察细菌质粒的变化。结果表明在恒化器小生境中76株初始菌检出29株带质粒,6个月后检测出6株菌全带质粒。 从不同地区分离出470株好氧异养菌,用硷裂解和琼脂糖电泳技术测出质粒菌的百分数,它们分别为:石油污染土49%;五氯酚污染土41%,对照土11.3%。 抗汞菌质粒检出数为62%。在1?2株带质粒菌中有78%对石油烃有不同程度的降解作用,这些带质粒菌74.6%是革兰氏阴性菌,其中假单胞菌类占31.6%
Different-Order Quasi-Phase Matching Harmonics in Quasiperiodic Ferroelectric Crystals
体细胞核移植牛肺脏中&lt;italic&gt;H19&lt;/italic&gt;和&lt;italic&gt;Xist&lt;/italic&gt;基因的DNA甲基化状态
应用ICP─AES法测定东北虎血清金属元素
用电感耦合等离子发射光谱分析(ICP一AES)法对8只东北虎血清中11种金属宏量和微量元素的含量进行了测定,8只东北虎各种元素平均含量的置信区间(μ)钠为242±83(mg/d1)、钾为128土42(mg/L)、钙为42上17(mg/L)、铜为O.26±O.O9(ms/L)、镁为11.1土4.2(mg/L)、锌为1.75±1.31(mg/L)、铁为1.6±O.5(mg/L)、钴为1.5±0.25μg/L)、锰为13.2土3.8μg/L)、钼为1O.4士O.67(μg/L)和铝为39.1±3.3(μg/L)。本文首次报道了多只东北虎血清多种元素的生理参考值,为东北虎多方面的研究和应用提供了科学依据
