Investigation on apoptosis of neuronal cells induced by Amyloid beta-Protein

Objective: To construct a PC12 cell strain with neuronal differentiation, and observe the apoptosis and pro-liferation activity effects induced these cells by Amyloid beta-Protein (Aβ-43). Methods: 1) PC12 cells in logarithmicgrowth phase were subcultured for 24 h. After the culture fluid was changed, the cells were treated with Rat-β-NGF andcultured for 9 days. 2) Neuronal differentiation of PC12 cells in logarithmic growth phase were divided into four groups:control group (0), experimental group (1), experimental group (2) and experimental group (3). The concentrations of Aβ inthe four groups were 0 μmol/L, 1.25 μ mol/L, 2.5 μ mol/L and 5 μmol/L, respectively. The cells were harvested at 24, 48 and72 h later and stained with AnnexinV-FITC/PI after centrifugation and washing. Then flow cytometry was conducted toexamine the apoptosis percentage. 3) NGF-induced PC12 cells were selected and Aβ with different concentrations wasadded. The final concentrations of Aβ were 0 μmol/L, 1.25 μmol/L, 2.5 μmol/L and 5 μ mol/L, respectively. After the cellswere incubated in an atmosphere of 5% CO2 at 37 ℃ in an incubator for 72 h, the OD values were examined. Results: 1)Neuronal differentiated PC 12 cell lines were successfully established. 2) Flow cytometric examination indicated that Aβ(1.25, 2.5, and 5.0 μmol/L) could effectively induce apoptosis of neuronal-differented cells at the 24 h, 48 h and 72 h timepoints. 3) Aβ (0-5.00 μ mol/L) had no obvious effect on proliferation or restraining of the neuronal differentiation of thePC 12 cells after a 72 h interacting process. Conclusion: This investigation revealed successful neuronal differentiation of thePC12 cell strain. The induction of apoptosis of the neurocytes by various concentrations of Aβ was observed and the in-fluence of Aβ on induced proliferation of PC 12 cells by Rat-β-NGF was revealed. This study -05 provide basis for futureresearch on the molecular cure of AD and interdiction of AD evolution.     

Clinical analysis of minimally invasive McKeown esophagectomy in a single center by a single medical group

Objective: McKeown esophagectomy followed by cervical and abdominal procedures has been commonly used for invasive esophageal carcinoma. This minimally-invasive operative procedure in the lateral prone position has been considered to be the most appropriate method. We describe our experiences in minimally invasive McKeown esophagectomy (MIME) for esophageal cancer. Methods: Between March 2016 and February 2018, a total of 82 patients underwent MIME by a single group in our department (a single center). All procedure, operation, oncology, and complication data were reviewed. Results: All MIME procedures were completed successfully, with no conversions to open surgery. The median operative time was 260 min, and median blood loss was 100 ml. The average number of total harvested lymph nodes was 20.1 in the chest and 13.5 in the abdomen. There were no deaths within 30 postoperative days. Twenty cases (24.4%) developed postoperative complications, including anastomotic leak in 4 (4.9%), single lateral recurrent nerve palsy in 4 (4.9%), bilateral recurrent nerve palsy in 1 (1.2%), pulmonary problems in 3 (3.7%), chyle leak in 1 (1.2%), and other complications in 7 (including pleural effusions in 4, incomplete ileus in 2, and neck incision infection in 1; 8.54%). Average postoperative hospitalization time was 12 d. Blood loss, operation time, morbidity rate, and the number of harvested lymph nodes were analyzed by evaluating learning curves in different periods. Significant differences were found in operative time (P=0.006), postoperative hospitalization days (P=0.015), total harvested lymph nodes (P=0.003), harvested thoracic lymph nodes (P=0.006), and harvested abdominal lymph nodes (P=0.022) among different periods. Conclusions: Surgical outcomes following MIME for esophageal cancer are safe and acceptable. The MIME procedure for stages I and II could be performed proficiently and reached an experience plateau after approximately 25 cases.     

在线课程质量观和质量要素的质性研究--基于专家、实践者和学习者的视角

本文采用扎根理论研究方法,通过对学术专家、实践者和学习者三类相关群体的访谈,调查高等教育和继续教育在线课程相关人群关于在线课程的质量观与对质量构成的认识,探索在线课程质量框架与要素,以期为促进人们对在线课程质量的共识,为改进和优化现有在线课程质量标准提供参考。研究通过对20位受访者累计22万字访谈文本的编码分析,发现四种质量观--服务质量观、系统性质量观、目标性质量观和增值性质量观,并定义出设计开发与实施运行两大类的九个在线课程质量要素--课程目标、课程内容、学习过程、学习支持服务、学习评价、媒体与技术环境、实施效果、改进发展和社会影响。其中,课程目标、学习内容与实施效果被定义为核心要素。本文基于TF-IDF关键词统计方法对三类群体的在线课程质量观差异进行了分析,并结合已有远程教育质量观和在线课程质量标准相关成果对本研究发现和定义的在线课程质量观、质量框架和质量要素进行了讨论与反思。     

开放、多元、综合的艺术教育——美国艺术教育考察报告

本文通过对美国艺术教育的实地考察和分析 ,指出美国艺术教育是在人文科技视野下实施的开放、多元、综合的艺术教育 ,具有如下几个特点 :从教育内容看 ,是跨学科、多层面、综合的 ;从教学方法看 ,是探究性和多元化的 ;从教育途径看 ,是学校、社会和家庭积极合作、互动的 ;艺术教师队伍结构灵活、专兼并举、素质较高。作者还就改革和加强我国艺术教育提出了若干思考     

关于我国换股合并会计处理方法的探讨

尽管权益结合法存在许多缺陷，但由于购买法目前在我国尚不具备现实运用环境，且为了促进我国企业合并的发展，现阶段应允许我国进行换股合并的食业采采权豁结合法。     

国际贸易中EDI的法律问题初探

EDI贸易方式的产生,给国际贸易中传统的“纸单证”带来了划时代的商业变革。EDI的迅速发展,不仅给实物界带来了重大影响,而且对传统法律提出了严峻挑战。由于数据电文的虚拟性和快捷性,加上传统立法对EDI缺乏规定,引发了与EDI有关的书面形式问题、签字问题、证据力问题、合同成立问题、信息失误的责任问题等一系列的法律问题。利用EDI从事国际贸易正成为商事交易的发展方向,传统的游戏规则应逐步淡出历史舞台,接受新事物已成为改善生产关系的必然选择。     

构建现代教育服务体系的理论与实践

大连教育学院为了很好地服务于本市新时期的初、中等教育,坚持科学发展观,积极构建现代教育服务体系:以"原野行动"服务于新农村建设的教师培训;以"大篷车计划"构建服务于教师专业发展的网络平台;以"空中课堂"服务于农村小学的英语教学;以"村小校长培训"服务于推进区域教育均衡发展的校长培训末梢工程;以"名师名校长培训"服务于全面实施素质教育的校长、教师培训;以"二二三四"工作服务于大连市的初、中等教育与教学。     

毛泽东时代的西部建设对西部大开发的启迪

本文全面总结分析了毛泽东时代西部建设的历史阶段和特点,进而提出今天西部大开发应汲取的历史上的经验教训.     

2015年高职高专全国大学英语竞赛测试分析与探讨

本文以2015年高职高专全国大学英语竞赛测试真题为例,对试题的结构、考察内容、测试题型、题量、分值比例进行归类量化分析,发现该竞赛试题的题量与难度呈逐年上升的趋势,测试内容愈加广泛,题型多样化的特点愈加明显;从而探讨该竞赛的测试特点与发展趋势,充分发挥大学英语竞赛对英语教学实践的促进作用。     

利用语音识别引擎实现电脑英语语音测试的探索

介绍了作研发的一套英语语音测试系统软件，能利用计算机判断识别学生的语言，可代替教师进行英语语音测试的繁重工作。