HBV再激活研究进展

随着免疫抑制剂及细胞毒性药物的广泛应用,HBV再激活越来越受关注。HBV再激活患者可发生肝衰竭,甚至死亡。对有HBV再激活发生风险者进行筛查、预防性抗病毒治疗、监测,已经成为各大指南的共识。本文就HBV再激活的发生风险因素、发生机制、预防性抗病毒治疗药物及疗程作一综述。“十三五”国家科技重大专项(2012ZX10002004

Comparison of uncut Roux-en-Y anastomosis and traditional Roux-en-Y anastomosis in the totally laparoscopic distal gastrectomy for gastric cancer: An analysis of multiple centers' data

目的对比非离断式(Uncut)Roux-en-Y吻合和传统Roux-en-Y吻合应用于全腹腔镜远端胃癌根治术后消化道重建的安全性和短期疗效。方法回顾性分析国内10家单位共60例远端胃癌根治术后全腹腔镜消化道重建的胃癌病人临床资料,根据消化道重建方式不同分为Uncut Roux-en-Y组(Uncut组)34例,传统Roux-enY组(传统组)26例。结果 Uncut Roux-en-Y吻合在消化道重建时间方面用时更短[(51.5±13.3)min vs.(80.4±16.2)min,P=0.000],出血量更少[(60.0±35.6)m L vs.(132.9±65.1)m L,P=0.000],且在进食半流饮食时间方面具有优势[(4.6±1.5)d vs.(7.2±2.3)d,P=0.000]。两组病人在留置胃管时间、术后排气时间、进食流质时间和术后住院时间方面差异无统计学意义。两组病人均无围手术期死亡病例,并发症发生率差异无统计学意义(8.8%vs.7.7%,P=0.875)结论 Uncut Roux-en-Y吻合和传统Roux-en-Y吻合应用于全腹腔镜下消化道重建安全可行,Uncut Roux-en-Y吻合在重建时间和控制出血量方面具有优势。Objective To compare the security and short-term effect of the digestive tract reconstruction during the totally laparoscopic distal gastrectomy for gastric cancer between the Uncut Roux-en-Y anastomosis and the traditional Roux- en- Y anastomosis. Methods The clinical data of 60 gastric cancer patients with digestive reconstruction underwent totally laparoscopic distal gastrectomy between December 2012 and June 2015 in 10 domestic hospital were analyzed retrospectively. According to the difference of digestive reconstruction,it can be divided into the Uncut Rouxen-Y anastomosis group with 34 patients and the traditional Roux-en-Y anastomosis group with 26 patients. Results In uncut Roux-en-Y anastomosis group,the operative time in digestive reconstruction was shorter[(51.5±13.3)min vs.(80.4±16.2)min,P=0.000]; the intraoperative blood loss was less[(60.0±35.6)m L vs.(132.9±65.1)m L,P=0.000];semi-liquid diet time was earlier[(4.6±1.5)d vs.(7.2±2.3)d,P=0.000]. However,there was no difference between the two groups on nasogastric tubegastrointestinaltwo groups on nasogastric tube,gastrointestinal transit,fluid diet and the duration of postoperative hospital stay. Both groups had no death case during the perioperative period and there was no significant statistical difference in the postoperative complication rates(8.8% vs. 7.7%,P=0.875).Conclusion The Uncut Roux- en- Y anastomosis and the traditional Roux-en-Y anastomosis are both safe and feasible for the digestive reconstruction under the totally laparoscopic distal gastrectomy for gastric cancer. Besides,the Uncut Roux- en- Yanastomosis has other advantages such as less reconstruction time and less bleeding.广东省科技计划项目(No.2014A020212591

数字微流控技术及其在生物分析中的应用

数字微流控技术是一种基于微电极阵列来实现离散液滴精确控制的新型液滴操纵技术。这种基于介电润湿现象实现的液滴电操纵体系,相比于传统微流控芯片具有自动化、可寻址、可动态配置、易集成等特点。该文介绍了数字微流控技术液滴驱动原理,总结了芯片的结构和常用的制作方法,举例阐述了现阶段该技术在生物分析化学领域的应用,并对其应用前景做了展望。国家自然科学基金资助项目(21735004,21435004,21775128,21705024,21521004);;长江学者和创新研究团队项目(IRT13036

The relationship between nutrients and phytoplankton community structure in northern Beibu Gulf

根据2011年4月和8月北部湾北部(北部湾20°n以北的海域)的调查数据,北部湾北部春夏两季共鉴定出浮游植物312种,隶属于4门78属,硅藻是主要优势类群。春季优势种为细弱海链藻(THAlASSIOSIrA SubTIlIS)、丹麦细柱藻(lEPTOCylIndruS dAnICuS)、奇异棍形藻(bACIllArIA PArAdOXA)和尖刺拟菱形藻(PSEudOnITzSCHIA PungEnS);夏季优势种仅为海链藻(THAlASSIOSIrA SP.)。浮游植物群落在春季可划分为2个子群落(SPr1和SPr2),在夏季可划分为3个子群落(SuM1、SuM2和SuM3)。该海域n/P比值一直处于高的水平,绝大部分的水域表现为磷限制,这可能是硅藻大量生长所造成的。春季SPr2群落优势种的柔弱角毛藻(CHAETOCErOS dEbIlIS)与除铵盐之外的营养盐具显著相关关系,奇异棍形藻与环境因子无相关关系。夏季SuM3群落优势种的奇异棍形藻与磷酸盐具显著相关关系。分析表明,琼州海峡过道水为北部湾北部输送了磷酸盐,而硅酸盐则主要由陆地径流输入。Phytoplankton community and nutrient concentration in the northern Beibu Gulf in April and August 2011 were investigated.In this research, 312 phytoplankton taxa were identified, which belonged to four phyla and 78 genera, with Bacillariophyta being the main group.The dominant species were Thalassiosira subtilis, Leptocylindrus danicus, Bacillaria paradoxa, and Pseudonitzschia pungens in spring, and Thalassiosira sp.in summer.Phytoplankton community in northern Beibu Gulf could be divided into two natural groups in spring(spr1 & spr2) and three in summer(sum1, sum2 & sum3).N/P ratio was in a relatively high level in the study area, and most of the waters were phosphorus limitated which resulted from diatom blossom.Chaetoceros debilis was the dominant species of group spr1 and had significant correlation with nutrient in spring, except for ammonium.Bacillaria paradoxa was the dominant species of group sum3 and had significant correlation with phosphate in summer, but, it was uncorrelated with any environmental factors as the dominant species of group spr2 in spring.Phosphate was transported to northern Beibu Gulf through the Qiongzhou Strait corridor water, and silicate was input by land runoff.海洋公益性行业科研专项项目(201005012

调动学生学习兴趣提高解剖学教学效果

学习兴趣是指一个人对学习的一种积极的认识倾向与情绪状态,是一种带有趋向性的心理特征[1]。在教学实践中经常可以发现,尽管师资水平、教学方法、设备条件、学生的文化程度诸多因素基本

An ecological study on zooplankton in the northern Beibu Gulf V: the effects of microzooplankton grazing on phytoplankton in summer

2011年8月份于北部湾北部海域5个观测站位获得的分层水样,分析了表层叶绿素A含量和表层微型浮游动物丰度以及类群组成;同时于现场采用稀释培养法研究了该海域浮游植物生长率(μ)和微型浮游动物的摄食率(g)。分析和测定结果表明:调查海区的微型浮游动物丰度400—1167个/l,类群组成以无壳纤毛虫为主;浮游植物的生长率为-1.50—1.13 d-1,微型浮游动物摄食率为0.33—1.08 d-1;推算微型浮游动物对浮游植物现存量以及初级生产力的摄食压力分别为28.1%—66.0%和-7.4%—438.4%。相对于中国其他海区,8月份北部湾北部海域微型浮游动物摄食速率处于中等水平。调查期间,广西沿海高生产力海区,浮游植物生长率大于微型浮游动物动物的摄食率,浮游植物生物量处于积累期;涠洲岛以南海域,浮游植物生产力较低,微型浮游动物摄食作用是控制浮游植物生长的重要因素。In August 2011,we quantified the impact of microzooplankton grazing on phytoplankton production in the surface waters of the northern Beibu Gulf,Vietnam.Shipboard dilution incubation experiments were carried out at five stations to calculate phytoplankton specific growth rates and the specific rates of grazing losses to microzooplankton.Dilution experiments using chlorophyll a( Chl a) as a tracer were used to estimate daily rates in two size fractions; image-analyzed microscopy provided quantitative estimates of microzooplankton standing stock( including ciliate and vertebrate larvae).PFW( particle-free water) was used to dilute seawater to five target dilutions of 0%,20%,40%,60%,and 80%.Microzooplankton grazing and phytoplankton growth rates were estimated by the linear regression of AGR( apparent growth rate) versus dilution factor.We estimated the grazing impact of microzooplankton on phytoplankton by calculating the percentage of phytoplankton standing stock and potential primary production ingested.Average total chlorophyll a concentration was( 0.67 ± 0.58) μg / L.Small-celled phytoplankton dominated this particular community.A notable characteristic of the phytoplankton community structure was that nano- and picoplankton made up a significant portion.Aloricate ciliates dominated the microzooplankton samples,in particular Strombidium,which accounted for 27.2% of total aloricate ciliate abundance.In addition,loricate ciliates and copepod nauplii were recorded.Microzooplankton densityvaried from 400 to 1167 ind / L.The horizontal distribution of microzooplankton was greater in nearshore than in offshore waters.Abundance did not differ significantly with chlorophyll a concentration in this study; however,there was a positive correlation between microzooplankton abundance and temperature.The phytoplankton growth rate( < 200 μm) ranged between-1.50 and 1.13 d-1,with the highest values being associated with nearshore waters.Meanwhile phytoplankton mortality due to microzooplankton grazing( 0.33—1.08 d-1) was highest at the same nearshore sites; however,growth rates were low at these sites.Consequently,microzooplankton consumed 28.1%—66.0% of chlorophyll a standing stocks and-8.1%—438.4% of the primary production per day.However,the grazing rate of microzooplankton on nanoplankton( 2— 20 μm) varied from 1.87 to 0.52 d-1,with an average of( 0.94±0.57) d-1.Given that the rates of grazing on phytoplankton of <200 μm were lower than those on nanoplankton,we conclude that microzooplankton prefer to graze on nanoplankton.There was a positive correlation between phytoplankton growth rate and grazing rate; in addition,significant differences between grazing rate and chlorophyll a were found.This suggests that microzooplankton grazing activity is the main factor regulating the community structure and restraining the growth of phytoplankton.During the investigation period, microzooplankton grazing effectively controlled the growth of phytoplankton,consuming 176.2% of primary production on average.When grazing rates are far greater than phytoplankton growth rates,energy is transferred from lower to higher trophic levels more effectively.In the surface waters of the northern Beibu Gulf,microzooplankton largely control the growth of phytoplankton by grazing offshore rather than in nearshore waters where primary production is high.The growth and grazing rates combined promote planktonic ecosystem stability in this area.These results indicate that grazing by microzooplankton is a key process controlling the growth of phytoplankton in this area.海湾公益项目(201005012

Ecosystem structure and function in northern Beibu Gulf: zooplankton spatial niche and its differentiation

根据2006—2007年北部湾北部海域4个航次调查资料,采用k-优势度曲线法对浮游动物种(类)群进行排序分析,运用lEVInS公式和PIAnkA指数分析了主要优势种(类)群的生态位宽度值和生态位重叠程度,并通过除趋势典范对应分析(dCCA)研究生态位分化状况。结果表明,该海区浮游动物优势种(类)群按生态位宽度值可划分为广生态位、中生态位和窄生态位三大类型。其中,广生态位的种(类)群如肥胖软箭虫、亚强次真哲水蚤、长尾类幼体等具有较强的生态适应性,生活范围较广;窄生态位的种(类)群,对环境的适应性较差,对海流和水团等环境因素的变化具有指示意义。生态位宽度能够反映种(类)群丰度季节变化,但不能反映具体丰度大小。北部湾北部全年主要优势种(类)群的生态位宽度值介于0.08—0.77之间,并且各优势种(类)群的生态位宽度差异较大,种对间生态位重叠值介于0.02—0.89之间,平均生态位重叠指数为0.45,种(类)群之间利用资源环境的互补性较强,这与海域内生境多样化并且各优势种对环境适应能力的差异存在一定联系。dCCA分析表明,影响浮游动物分布的主要因子是水深、温度和盐度,其次是叶绿素A和溶解氧。The concept of ecological niche had remained as one of the core ideas in ecological research for almost a century,which was closely linked with interspecific competition,resource utilization had played an important role in the study of community composition and function,of the relationships among species,biodiversity,community succession and population evolution.Based on four seasonal investigations( Spring 2007,Summer 2006,Autumn 2007 and Winter 2006) in northern Beibu Gulf from 2006 to 2007,the niche breadth,niche overlap,spatial differentiation and environment effects on the abundance and spatial distribution of zooplankton were studied with qualitative and quantitative methods.The cumulative top 80% of zooplankton dominant populations were selected by the K-dominant curve method,then the niche breadths and their overlaps of zooplankton were measured using the formulas proposed by Levins Niche Breadth index and the Pianka Niche Overlap index,and the spatial niche differentiation was studied by using Detrended Canonical Correspondence Analysis( DCCA) method.The results showed that the zooplankton dominant species in northern Beibu Gulf were classified in to three groups,i e.,wide niche breadth groups( Bi= 0.60—0.77),middle niche breadth groups( Bi= 0.30—0.60),narrow niche breadth groups( Bi= 0.08—0.30) based on the niche breadth value.The niche breadths of zooplankton such as Sagitta enflata,Subeucalanus subcrassus and Macrura larvae were wider,which was related with their own characteristics and the capability of adapting environment,while the species whose niche breadths were narrower such as Doliolum denticulatum and Dolioletta gegenbauri will be considered as an indicative significance for ocean currents and water masses.Niche breadth could reflect the zooplankton abundance with the seasonal dynamic changes,and also could objectively reflect the species in the habitat in which the distributions of degree but it could not reflect the Accurate zooplankton abundance.The niche breadth values of dominance zooplankton species ranged between 0.08 and 0.77 in the whole year and The niche breadth difference among the dominant populations was great; The niche overlap values of dominance zooplankton species ranged between 0.02 and 0.89 in the whole year and the average niche overlap index was 0.45,there was strong complementarity in terms of the utility of resource among zooplankton populations,which had certain relationship with northern Beibu Gulf habitat diversification and the strong complementarity in terms of the utility of resource among zooplankton populations.The Detrended Canonical Correspondence Analysis result showed that depth,temperature and salinity had more important influence on the species spatial distribution than Chlorophyll a and dissolved oxygen.海湾公益项目(201005012); 我国近海海洋综合调查与评价专项(908-01-ST09

The Seismic Detecting Technique on Gas Hydrates Based on Wave Impedance Inversion

天然气水合物作为特殊的地质体,可以有效地粘结碎屑颗粒,降低沉积物孔隙度,它的存在改变了地层沉积物的物理性质,造成天然气水合物与围岩速度反差较大,从而与围岩之间存在明显的波阻抗差。为了对地层中是否有天然气水合物赋存进行地震检测,对南海北部神狐海域的天然气水合物赋存区域的地震资料进行波阻抗反演分析,结果显示波阻抗反演方法能够作为探测天然气水合物的一种技术手段,研究区天然气水合物矿体的波阻抗呈高值分布特征,波阻抗值约为3 850--3 960 g/CM3.M/S。综合分析认为,波阻抗反演方法能够用于天然气水合物的地震探测、储层分析和综合研究工作中,反演结果可以为天然气水合物储量计算提供比较准确的矿体面积和厚度参数。As specific geologic body,gas hydrate can cement effectively clastic particles and reduce porosity of deposition,so its presence changes physical property of the sedimentary strata and results in the difference of seismic-wave velocity between gas hydrate and the surrounding rock,and there exists obviously wave impedance difference.In order to detect the presence of sediments with gas hydrate,seismic data of gas hydrate zone in the Shenhu area of the northern South China Sea were used in the wave impedance inversion through practice,testing and summary.Wave impedance inversion method is considered as a kind of good seismic detection technique for identification of gas hydrates,meanwhile,the wave impedance of gas hydrate zone shows high value in the study area,and the wave impedance value is about 3,850-3,960 g/cm3·m/s.All the results suggested that wave impedance inversion can be used for detection,reservoir analysis and comprehensive research of gas hydrates.The wave impedance inversion results can provide comparatively accurate area and thickness parameters of gas hydrate zone for reserves calculation.国家高技术研究发展计划项目(2006AA09A202);国土资源部公益性行业科研专项项目(200811014);国土资源部海洋油气资源与环境地质重点实验室资助项目(MRE200911);国家重点基础研究发展计划项目(2009CB219502

Impeded Nedd4-1-Mediated Ras Degradation Underlies Ras-Driven Tumorigenesis

RAS genes are among the most frequently mutated proto-oncogenes in cancer. However, how Ras stability is regulated remains largely unknown. Here, we report a regulatory loop involving the E3 ligase Nedd4-1, Ras, and PTEN. We found that Ras signaling stimulates the expression of Nedd4-1, which in turn acts as an E3 ubiquitin ligase that regulates Ras levels. Importantly, Ras activation, either by oncogenic mutations or by epidermal growth factor (EGF) signaling, prevents Nedd4-1-mediated Ras ubiquitination. This leads to Ras-induced Nedd4-1 overexpression, and subsequent degradation of the tumor suppressor PTEN in both human cancer samples and cancer cells. Our study thus unravels the molecular mechanisms underlying the interplay of Ras, Nedd4-1, and PTEN and suggests a basis for the high prevalence of Ras-activating mutations and EGF hypersignaling in cancer. © 2014 The Authors