Marine flavobacterium Gramella flava JLT2011 utilization polysaccharide of phytoplankton and characterization of new species of Pelagibaca bacterium

海洋浮游植物是海洋食物网的初级生产者，是海洋有机质重要分泌者。海洋浮游植物光合作用产生的有机质,通过海洋细菌分泌的一系列胞外酶等将颗粒有机质POM（ParticleOrganicMatter,POM）进一步代谢为生物可利用的溶解有机质（BioavailableDissolvedOrganicMatter,BDOM）。在这一个过程中噬纤维菌-黄杆菌-拟杆菌(Cytophaga-Flavobacterium-Bacteroides,CFB)菌群起着重大的作用。这类细菌形态多样，一般具有较强的运动性和粘附性，能附着在大颗粒物质上生存，可以降解一般细菌难以利用的大分子有机质。从而削弱了基于浮游植物的沉...Marine phytoplankton, an important source of marine organic matter, is primary producers of the marine food web. Particle Organic Matter (POM), which is produced by marine phytoplankton photosynthesis, were further mineralized to bioavailable dissolved organic matter (BDOM) by marine bacteria through a series of secrete extracellular enzymes. In this process, Cytophaga - Flavobacterium - Bacteroid...学位：理学硕士院系专业：海洋与地球学院_海洋生物学学号：2232012115132

Phytoplankton community structures revealed by pigment signatures in Norwegian and Greenland Seas in summer 2012

对2012年中国第5次北极科学考察期间的挪威海和格陵兰海两个断面的光合色素进行了高效液相色谱(HPlC)分级分析,通过藻类色素化学分类分析软件(CHEMTAX)获得了不同浮游植物类群对叶绿素A的贡献,进而得到该海域表层和次表层(30 M)的浮游植物群落结构。结果表明:表层总叶绿素A的浓度为23.59 ng/l,低于次表层的30.38 ng/l,其中浮游植物根据粒径划分对总叶绿素A的贡献由高到低依次是微型浮游植物、小型浮游植物和微微型浮游植物。该海域同时存在葱绿叶绿素(PrASInO)、墨角藻黄素(fuCO)、别藻黄素(AllO)、多甲藻素(PErId)、玉米黄素(zEA)、19-丁墨甲藻黄素(19'bf)和19-六已墨甲藻黄素(19'Hf)等色素,其浓度和分布与温盐和营养盐等环境因子存在一定的相关性。不同粒径浮游植物色素组成显示,微微型浮游植物群落中以S型定鞭藻(28%)、n型定鞭藻(21%)、硅藻(18%)和青绿藻(12%)占优;微型浮游植物群落的优势类群为S型定鞭藻(53%)、n型定鞭藻(20%)和硅藻(12%);而小型浮游植物群落主要为硅藻(63%)和甲藻(17%)。Composition of phytoplankton controlled not only the formation of the Food Chain,but also the efficiency of energy transfer.At the same time,phytoplankton influenced the distribution of nutrient and the sedimentation of organic particulate matter.So study of phytoplankton community structures plays an important role in understanding the ecological function of phytoplankton.Photosynthetic pigments needed by photosynthesis,are very good biomarkers.They can be used to research and characterize phytoplankton community structure.Norwegian and Greenland Seas which are influenced by the Arctic water with low temperature and salinity and Atlantic water with high temperature and salinity.Understanding of correlation between environmental factors and phytoplankton community structure,is important for understanding the community structure of the marine organisms and their ecological function.During the 5thChinese Arctic Research Expedition in summer 2012,we analyze the photosynthetic pigments fromNorwegian and Greenland Seas by HPLC.Contributions of different phytoplankton assemblages to Chlorophyll a were obtained by Chemical Taxonomy( CHEMTAX),and thus resulted in composition of the phytoplankton community structure at the surface and subsurface water( about 30 m depth).The result showed that average concentration of Chlorophyll a at surface water was 23.59 ng / L,lower than that at upper water( 30.38 ng / L).The contributions of phytoplankton to Chlorophyll a were nano-> micro-> pico-one.Prasinoxanthin,Fucoxanthin,Alloxanthoxyletin,Peridinin,Zeaxanthin,19'-but-fucoxanthin,19-hexanoyloxyfucoxanthin were observed in the waters.Their distributions were relative to environmental factors,including Nutrients,temperature and salinity.These photosynthetic pigments showed negative correlations with temperature and salinity.Whereas they showed positive relations with nutrients,including NO-2,NO-3,SiO3 2-and PO3-4.The correlations of different phytoplankton and environmental factors were different.Diatoms had a very significant positive correlation with SiO3 2-,but had no correlation with PO3-4,NO-2and NO-3; Haptophytes-N had significant positive correlations with PO3-4,NO-2and NO-3; Haptophytes-S also had a positive correlation with PO3-4,but had no correlation with NO-2and NO-3.The maximum values of these photosynthetic pigments,except for Zea and Fuco,existed in the subsurface of the section BB.The distribution and concentration of photosynthetic pigments could explain the distribution and abundance of the phytoplankton to some extent.Not only because the pigments are complex and multiple,but also because there are inevitable errors in the testing and sampling,we cant determine the existence and abundance of the phytoplankton.So we use the CHEMTAX to obtain the contributions of different phytoplankton assemblages to Chlorophyll a,and thus resulted in composition of phytoplankton community structure.The composition of phytoplankton showed that Haptophytes-S( 28%), Haptophytes-N( 21%),Diatoms( 18%),and Prasinophytes( 12%) were main assemblages in the picoplankton; the main composition of nanophytoplankton were Haptophytes-S( 53%),Haptophytes-N( 20%),and Diatoms( 12%); meanwhile, Diatoms( 63%) dominated the microphytoplankton,followed by Dinoflagellates( 17%).Haptophytes-S,Haptophytes-N and Diatoms were dominant species in the surface and subsurface of section BB and AT belonging to the Norwegian and Greenland Sea.If Fucoxanthins and Diatomss existence in picophytoplankton could explain the tendency of phytoplankton to micro and miniaturization,these still need to be more sufficient evidence.国家自然科学基金(41076130;41206189); 南北极环境综合考察与评价专项(CHINARE2011-2015

Desorption Electrospray Ionization Mass Spectrometry for Monitoring the Kinetics of Baeyer-Villiger Solid-State Organic Reactions

Desorption electrospray ionization mass spectrometry (DESI-MS) has been used for monitoring solid-state organic reaction in ambient air, specifically the Baeyer-Villiger (BV) type reaction involving the oxidation of ketones (benzophenone or deoxybenzoin) by m-chloroperbenzoic acid (m-CPBA) in solid-state. The DESI mass spectra obtained at regular intervals during the BV reaction processes are featured, with the amount of ester products increasing as those of ketone reactants decrease. Quantitative analyses of relative intensities of the product, made to quantify the reaction degree of typical solid-state organic reaction (SSOR), show a precision with RSDs of around 5% to 12%, though the RSDs for direct analysis of intensities of the reactant or the product in the solid-state are obviously larger. The kinetics of the Baeyer-Villiger type reactions in solid-state are shown to be dramatically different, in reaction rate, kinetic curve, as well as concentration dependence, from those of the same reactions taking place in solution.NSFC,20525103,20721001 National Basic Research Program of China (973 Program)2007CB81530

Trisomy 21-induced Dysregulation of Microglial Homeostasis in Alzheimer’s Brains is Mediated by USP25

阿尔茨海默病（Alzheimer’s disease, AD）是一种最为常见的与记忆、认知能力退化相关的渐进性神经退行性疾病。唐氏综合征（Down’s syndrome, DS）是早发型阿尔茨海默病的一个重要风险因素，作为最常见的智力障碍遗传疾病，厦门大学医学院神经科学研究所王鑫教授团队揭示了治疗阿尔茨海默病和唐氏综合征新的治疗靶点，并且在小鼠模型上利用USP25小分子抑制剂成功地改善了阿尔茨海默病小鼠的认知功能，缓解了神经退行性病变的病理进程。该研究工作由王鑫教授指导完成，厦门大学医学院助理教授郑秋阳和博士生李桂林完成主要实验工作，王世华、朱琳、高月、邓青芳、张洪峰、张丽珊、吴美玲、狄安洁参与了部分研究工作。厦门大学医学院许华曦、赵颖俊和孙灏教授在研究过程中给予大力帮助和支持，清华大学董晨教授提供了Usp25基因敲除小鼠，厦门大学附属妇女儿童医院周裕林教授和郑良楷博士帮助收集了脑组织样品。Down syndrome (DS), caused by trisomy of chromosome 21, is the most significant risk factor for early-onset Alzheimer’s disease (AD); however, underlying mechanisms linking DS and AD remain unclear. Here, we show that triplication of homologous chromosome 21 genes aggravates neuroinflammation in combined murine DS-AD models. Overexpression of USP25, a deubiquitinating enzyme encoded by chromosome 21, results in microglial activation and induces synaptic and cognitive deficits, whereas genetic ablation of Usp25 reduces neuroinflammation and rescues synaptic and cognitive function in 5×FAD mice. Mechanistically, USP25 deficiency attenuates microglia-mediated proinflammatory cytokine overproduction and synapse elimination. Inhibition of USP25 reestablishes homeostatic microglial signatures and restores synaptic and cognitive function in 5×FAD mice. In summary, we demonstrate an unprecedented role for trisomy 21 and pathogenic effects associated with microgliosis as a result of the increased USP25 dosage, implicating USP25 as a therapeutic target for neuroinflammation in DS and AD.This work was supported by the National Natural Science Foundation of China (31871077, 81822014, and 81571176 to X.W.; 81701130 to Q.Z.), the National Key R&D Program of China (2016YFC1305900 to X.W.), the Natural Science Foundation of Fujian Province of China (2017J06021 to X.W.), the Fundamental Research Funds for the Chinese Central Universities (20720150061 to X.W.), and the BrightFocus Foundation (A2018214F to Yingjun Zhao). 该研究工作得到国家重点研发计划项目、国家自然科学基金、福建省自然科学基金、厦门大学校长基金的资助和支持

SPATIAL DISTRIBUTION of PICO-AND NANO-PHYTOPLANKTON AND BACTERIA IN THE CHUKCHI SEA WITH RELATION TO WATER MASSES

利用2008年中国第三次北极科学考察的机会,分析夏季楚科奇海微微型、微型浮游植物和细菌丰度的分布特征,并探讨它们与楚科奇海水团之间的关系。结果表明:与北冰洋的其他海域相比,楚科奇海的微型浮游植物丰度相对较高(0.03—10.23x103CEllS·Ml-1),微微型浮游植物则大致相同(0.01—2.21x103CEllS·Ml-1),而浮游细菌丰度明显较高(0.21—9.61x106CEllS·Ml-1)。白令海陆架水与海冰融化混合水和阿纳德尔水浮游植物群落结构不同,夏季随着太平洋水入流水对楚科奇海的日益影响,其水体本身的群落结构可能被外来群落替代。Based on the third Chinese Arctic Expedition cruise in the summer of 2008,the distribution patterns of pico-and nano-plankton and bacterial abundances were studied in the Chukchi Sea.Pico-and nano-phytoplankton abundances ranged from 0.01×103 to 5.51×103 cells·mL-1 and from 0.01×103 to 5.51×103 cells·mL-1,respectively.The lowest numbers of bacteria in the entire water column were recorded at station R17 at 100 m depth(0.21×106 cells·mL-1),and the highest concentration was observed at station R09 at 10 m depth(9.61×106 cells·mL-1).Our results demonstrate that melting sea ice affects the physical characteristics of the Chukchi Sea by reducing the salinity of the surface mixed layer which,in turn,results in greater hydrodynamic stability of the water column.These changes were accompanied by increasing bacterial concentrations.Pacific warm water brought high nutrient concentrations into the Chukchi Sea,which led to higher abundances of bacteria and nano-phytoplankton compared to other regions of the Arctic Ocean.However,the number of pico-phytoplankton in the Anadyr Water related well to chlorophyll a,and the number was greater than those in the other two water masses.The structure of pico-and nano-plankton communities,coupled with the water masses in the Chukchi Sea,can be considered indicators of the inflow of Pacific warm water into the Chukchi Sea.国家自然科学基金(41076130;40576002);科技部国际合作司对欧盟科技合作专项经费项目(1105);国家海洋局青年海洋科学基金项目(2010116)资

尊重生命 尊重成长

自然孕育，自然分娩，是每一个妇产科医生对准妈妈的忠告和祝福。但同时我们也得认识到：需要进行干预的时候接受干预，也是顺应自然。现实生活中，走向任何极端，都不是真正地尊重自然。</p