On the Coarse Embeddability of l_p-Spaces Into l_2

对l(_P-)空间与l_2之间粗嵌入关系作进一步的研究,证明了度量空间X可粗嵌入进l_2当且仅当存在某个20 such that X can be coarsely embedded into {l_p,2<p≤p_0} uniformly.This gave an equivalent condition for the coarse embeddability of metric spaces into l_2.国家自然科学基金(11101340;11201160); 福建省自然科学基金(2010J05012;2012J05006); 华侨大学高层次人才科研启动项目(11BS223

Pathways between superoxide and peroxide species on small La-O clusters

采用密度泛函理论方法考察了lA-O团簇上超氧物种与过氧物种间转化的连接途径.单重态下,团簇上单个超氧物种可通过一系列臭氧物种转化为过氧物种,且转化能垒较高;三重态下,单个超氧物种则并无与过氧物种间连接的途径.然而,lA-O团簇上两超氧物种间的相互作用及其转化也具单重态和三重态两条途径.三重态下,超氧物种可很容易地转化为过氧物种(O2+O2O22+O2),超氧物种与过氧物种处于快速的交换状态之中;单重态下,超氧物种转化为过氧物种则需较高的活化能垒,表明在单重态下这些氧物种具有较高的稳定性.Density functional theory calculations were used to investigate the connection between superoxide and peroxide species on La-O clusters.In the singlet state,a superoxide species can transition into a peroxide species by moving through a substantial energy barrier via a series of ozonides.In the triplet state,there is no connection between the two species,although there are two paths(singlet and triplet) that allow the interaction and subsequent transformation of two superoxide molecules on a La-O cluster.The superoxide species readily transitions to a peroxide species through a triplet pathway(O2–+ O2– O22– + O2),in which the superoxide species undergoes rapid exchange with the peroxide.In the singlet path,however,the superoxide species must move through a pronounced energy barrier to change into a peroxide species,demonstrating that these oxygen species are high- ly stable in the singlet state.supportedbytheNationalBasicResearchProgramofChina(973Program;2010CB732303); theNationalNaturalScienceFoundationofChina(21033006;21373169;20373054); theProgramforChangjiangScholarsandInnovativeResearchTeamintheUniversity(IRT1036)~

Diet composition of Difflugia tuberspinifera( testate amoeba) based on a clone library technique

瘤棘砂壳虫是东亚特有的原生动物,广泛分布于长江与珠江中下游以及福建地区的湖泊和水库,作为水生态系统的捕食者,在维持水生态系统的结构与功能方面发挥着重要作用。利用18S rrnA基因PCr扩增和克隆文库测序等分子生物学技术方法,从基因水平研究瘤棘砂壳虫的食物组成。结果表明:所获得的46条序列在97%相似度水平含有11类OTuS(OPErATIOnAl TAXOnOMIC unITS,操作分类单元),其中包括轮虫6个,桡足类5个,说明瘤棘砂壳虫的捕食类群以轮虫和桡足类为主,同时也证明单细胞生物可以直接以多细胞的后生动物为食。此外,通过克隆文库测序技术分析原生动物的食物组成比例,不仅是一种方便、高效、快速,重复性高的方法,同时也为分析原生动物的生态功能提供了一种新的视角。Difflugia is a morphologically diverse genus of the free-living shelled amoeboid protozoa that are important components of freshwater ecosystems and play crucial roles in nutrient cycles and energy flow through food webs.Difflugia tuberspinifera is an endemic species of East Asia and is widely distributed in freshwater lakes and reservoirs in China.Clearly,this species plays a critical role in maintaining the structure and function of freshwater ecosystems.However,little is known about its diet composition and predatory behavior at both species and gene levels.This testate amoeba( D.tuberspinifera) was first found in the Wujiang River,Guizhou Province,China.Subsequently,more detailed studies on its morphology and biometry have been done on natural populations from Yangtze River and Pearl River valleys,and Fujian reservoirs.Recently,Han et al.illustrated that D.tuberspinifera is an active and agile hunting carnivore that can capture swimming prey including micro-particulates,rotifers,and other metazoans.In previous studies,however,the specimen identifications were done by microscopic examination,which requires a broad and deep taxonomic knowledge and is verylaborious,time-consuming,and somewhat variable because of insufficient taxonomic resolution.In order to facilitate the identification of diet composition in D.tuberspinifera,an inexpensive,efficient,rapid and easy-to handle gene clone library has been developed for diet detection and analysis.The plankton samples were collected from the Hubian Reservoir in Xiamen city in September of 2010.Individual cells were isolated using a glass capillary under an inverted microscope and washed 3—5 times with distilled water before DNA extraction and PCR amplification.The 18 S rRNA gene was amplified by the universal eukaryotic primers,and the purified PCR products were ligated into the p GEM-T vector and transformed into Escherichia coli DH5α-competent cells.In total,46 plasmids containing target gene fragments were successfully identified and sequenced.Each sequence was compared with sequences available in the Gen Bank database using BLAST,and the closest relatives were identified for diet or food composition analysis.Finally,11 OTUs( operational taxonomic units) were identified at 97% sequence similarity level,and they belonged to either Rotifera( 52%) or Copepoda( 48%).Our results,combined with existing data,suggested that:1) the diet composition of Difflugia tuberspinifera is composed of both rotifera and copepoda species;2) unicellular protozoa are not only the food of metazoa,but they can also prey on multicellular micro-metazoa;3) molecular methods are universally applicable,and the SSU rRNA( small subunit ribosomal RNA) gene clone library is an efficient,rapid,and repeatable approach to study the diet composition of protozoa.国家自然科学基金项目(31172114;30800097); 福建省杰出青年科学基金项目(2012J06009

二色桌片参酶解液的抗胃癌细胞MGc80-3作用

用二色桌片参［Ｍｅｎｓａｍａｒｉａｉｎｔｅｒｃｅｄｅｎｓ（Ｌａｍｐａｒｔ）］酶解液处理培养的人胃腺癌细胞ＭＧｃ８０－３后有如下效应：对其生长的抑制率可达３２．７５％，经处理后细胞铺展更好，透光性较好，细胞表面较光滑，微绒毛少，核膜规则而光滑，核仁明显．在软琼脂中的集落形成率由０．０１６７％下降为０．００４５％．Ｃｏｎ－Ａ介导的细胞凝集率在１００μｇ／ｍＬ浓度中下降４０．２个百分点，在２００μｇ／ｍＬ中下降３５．４个百分点；对裸小鼠致瘤的瘤重下降３３．０７％．结果表明二色桌片参酶解液对该胃癌细胞的生长有一定的抑制作用，对其恶性表型有一定的逆转作用

Bacterial community and its relation to environmental variables in a subtropical stratified reservoir for drinking water supply in autumn

水库在我国东南沿海地区是重要的饮用水水源地,对地区经济发展和社会稳定起到重要作用。选择亚热带地区典型的热分层水库——福建莆田东圳水库,于2011年秋季稳定分层期,以水体温度的垂直变化特征为依据进行分层采样。应用PCrdggE和克隆测序的方法研究浮游细菌群落的垂直分布特征,利用多元统计分析揭示细菌群落与热分层水体理化指标之间的关系。结果显示:溶解氧、电导率、叶绿素A、总氮、氨氮及硝氮在上下层水体中的分布有显著差异,下层缺氧区细菌的SHAnnOnWIEnEr指数和dggE条带数明显高于上层好氧区,表明东圳水库热分层水体中存在明显的物理、化学及生物分层现象。测序结果表明β-变形菌可能是东圳水库中占优势的细菌类群,统计结果提示溶解氧是显著影响细菌群落组成的环境因子。热分层水体的物理化学分层与水体细菌群落结构密切相关,提示水库生态学研究应对水体热分层给予重视。Fujian reservoirs in southeast China are important water resources for economic and social sustainable development,although few have been studied previously.Dongzhen Reservoir,a typical subtropical stratified reservoir in Fujian,was chosen for investigation of bacterial distribution,composition and diversity in autumn 2011.As the only built large reservoir in Putian City,it plays an important role in irrigation,flood control,hydroelectric power,and water supply.Dongzhen Reservoir shows an obvious phenomenon of water thermal stratification during summer and autumn,thus creates a unique gradient of environmental variables along the water column.We investigated the bacterial community and its relation to environmental variables in this study for a better understanding of vertical distribution of bacterial community and theprimary environmental drivers in a stratified reservoir.Five water samples were collected from five different depths according to the vertical changes of temperature.Both PCR-DGGE and sequencing were used to investigate the bacterial community and diversity.Moreover,physical and chemical parameters were measured according to the national standard methods.Multivariate statistical techniques were used to examine the relationship between bacterial community and environmental variables.Principal component analysis( PCA) clearly showed that water temperature,dissolved oxygen( DO),chlorophyll a( Chl a),total nitrogen( TN),ammonia nitrogen( NH4-N),nitrite / nitrate nitrogen( NOx-N) and electric conductivity of the upper aerobic zone were differed from those of the deeper anoxic zone.Both the number of DGGE bands and the Shannon-Wiener index of the deeper anoxic zone were higher than those of the upper aerobic zone.Further,two groups were distinguished by the cluster analysis of bacterial communities based on the Bray-Curtis similarity.Thus,Dongzhen Reservoir presented an obviously physical,chemical,and biological stratified phenomenon.Seven bands that common to all sampling depths were extracted and sequenced,and among which four were identified as Betaproteobacteria,indicating that Betaproteobacteria were the most dominant taxa in Dongzhen Reservoir in autumn.Bacterial community composition and diversity differed greatly among different sampling depths,and these differences were closely related to the physical and chemical stratification of the water body.Redundancy analysis( RDA) demonstrated DO was the significant environmental variable that shaping the bacterial community and diversity( P < 0.01).Therefore,we should pay more attention to DO and thermal stratification of reservoirs for sustainable reservoir management.国家重大科学研究计划(2012CB956103); 中国科学院知识创新工程方向项目(KZCX2-YW-QN401); 国家自然科学基金面上项目(31172114); 福建省杰出青年科学基金项目(2012J06009

抗病毒治疗HIV/AIDS患者抑郁状况及其影响因素分析

目的了解接受抗病毒治疗HIV/AIDS患者抑郁状况及其影响因素。方法2022年7月-2022年9月，采用连续抽样法从南京市抗病毒治疗机构招募接受抗病毒治疗HIV/AIDS患者，进行匿名问卷调查，收集患者基本信息，采用患者健康问卷抑郁量表（PHQ-9）、简化的Berger艾滋病感知歧视量表（BHSS）及感知社会支持的多维度量表（MSPSS）调查抑郁状况、HIV耻辱得分以及社会支持水平等。采用多因素Logistic回归分析患者抑郁的影响因素。结果本研究共收集有效问卷1 879份，抑郁检出率为50.1%，多因素logistic回归分析结果显示：相较于初中及以下文化程度的患者，研究生及以上文化程度抑郁的风险更低［OR=0.534，95%CI（0.341，0.835），P=0.006］；相较于抗病毒治疗时长&lt;1年，抗病毒治疗时长1~5年［OR=0.729，95%CI（0.536，0.991）］、&gt;5~10年［OR=0.516，95%CI（0.379，0.702）］、&gt;10年［OR=0.603，95%CI（0.375，0.969）］抑郁的风险更低；相较于中低社会支持水平，高社会支持水平是HIV/AIDS患者抑郁保护性因素［OR=0.430，95%CI（0.349，0.530），P＜0.001］；相较于未存在治疗药物副作用，存在药物副作用发生抑郁的风险更高［OR=2.260，95%CI（1.833，2.786），P＜0.001］；同时在HIV耻辱感量表得分越高，抑郁的可能性越高。结论南京市抗病毒治疗患者抑郁检出率较高，启动抗病毒治疗后应加强患者的药物副作用及心理状态监测，开展心理干预，缓解心理问题出现，提高患者的生命质量

弹道靶上的跨音速实验

本文介绍用弹道靶作跨音速试验的新方法,在二级轻气炮上采用了二个特殊的新技术:充气放炮能发射模型达到亚音速,低充填条件能发射模型达到跨、超音速。由于初始加速度较小,发射的模型外形完整,姿态稳定;加上没有支撑干扰和小洞壁效应的优点,使弹道靶设备在跨音速实验方面有特殊的优越性,用上述技术得到了圆球跨音速流场的清晰照片,其中击波脱体距离、分离点位置、颈部宽度、尾迹形状与超音速、高超音速流动比较有明显变化。文中M≈1.010和M≈0.99的二张全流场照片是十分有意义的。最后提出一个想法,用靶场加压、降温的方法可以提高雷诺数直到10~7以上

福建城市化发展战略博士笔谈

2003年5月,“福建省博士创业促进会”在福州举办了福建省城市发展战略“博士月谈”,与会者主要是省内高校和科研单位的专家、博士。会上,大家用书面发表意见,畅所欲言,崇论宏议。本刊精选部分意见,以飨读者。相信这些意见对福建城市化问题研究的深化将起到积极的推动作用