DDEFL1的结构和功能研究进展

DDEFL1又称为ASAP3(、ACAP4或UPLC1,属于小G蛋白家族中Arfs家族的一种ArfGAP。人的肝和肺是DDEFL1表达水平较高的两个组织[1]。了解DDEFL1的结构及功能,可以为肝癌或其它癌症患者提供一种新的基因治疗方案

澜沧江中上游鱼类生物多样性现状初报

对澜沧江上游及支流的鱼类和环境调查显示流域片段化对鱼类生物多样性产生了较大的影响。从漾濞江和西洱河的比较可以看出，前者因为没有梯级电站，鱼类的种类和数量并无太大的变化，而西洱河由于过度的梯级开发和污染，鱼类濒于灭绝，洱海由于江湖的隔绝，外来种的引入使得土著鱼类种群数量急剧减少。干流上大坝（漫湾水电站）的修建使得流水变为静水环境而产生一系列的变化使鱼类的种类和种群数量产生变化

Different roles of the left inferior prefrontal cortex in visual Chinese word recognition

目的 利用事件相关功能磁共振成像（functional MRI）技术比较中文双字真词与假词的认知加工的脑机制。方法 14名大学生在MR扫描过程中执行词汇判断任务，用视觉方式随机呈现120个双字词，其中真、假词各60个。结果 真、假词的判断激活了相似的包括双侧额下回，颞中回，梭状回和舌回，双侧缘上回，丘脑等区域。其中，左侧额下回（BA44／45区）在假词条件下的激活强度显著高于真词。结论 左额下回可能与语音存贮、行为选择或调控注意有关

New Anthraquinone Derivative Produced by Cultivation of Mangrove Endophytic Fungus Fusarium sp. ZZF60 from the South China Sea

通过人工发酵培养,从南海红树林内源真菌Fusarium sp.ZZF60的培养液中分离得到:1种新蒽醌衍生物,6,8-二甲氧基-1-甲基-2-(3-氧丁基)蒽醌(1),以及5种已知化合物:7-羟基-3-(4-甲氧基苯基)苯并-γ-吡喃酮(2),2,4-二羟基-6-[(1′E,3′E)-1′,3′-戊二烯基]苯甲醛(3),(E)-4-羟基肉桂酸甲酯(4),4-(4-羟基苯基)-2-丁醇(5),4-羟基苯甲酸(6)。它们的结构通过MS、NMR等波谱分析推导确定。初步药理活性显示,化合物1抑制体外培养人喉癌细胞Hep2和人肝癌细胞HepG2的IC50分别为16和23μmol/L。 A new anthraquinone derivative,6,8-dimethoxy-1-methyl-2-（3-oxobutyl） anthrakunthone（1）,together with five known compounds,7-hydroxy-3-（4-methoxyphenyl）-chromen-4-one（2）,2,4-dihydroxy-6-[（1′E,3′E）-penta-1′,3′-dienyl]-benzaldehyde（3）,（E）-4hydroxycinnamic acid methyl ester（4）,4-（4-hydroxyphenyl）-butan2-ol（5）,and 4-hydroxybenzoic acid（6）,were isolated from the marine mangrove endophytic fungus Fusarium sp.ZZF60 from the South China Sea.Their structures were elucidated by spectral data of IR,MS and NMR.In the preliminary bioassay,compound 1 showed cytotoxicity towards Hep2 and HepG2 with IC_50 values of 16 μmol/L and 23 μmol/L,respectively.国家“八六三”计划(2006AA09Z422);国家自然科学基金(20072058和20572136);广西自然科学基金(0832081);广西民族大学科学研究基金(200702YJ18)资助项

Alkaloid Metabolites of Mangrove Endophytic Fungus ZZF42 from the South China Sea

从南海红树林内生真菌ZZF42的代谢产物中分离得到4种生物碱:Apicidin(1),N-methylharman(2),环苯丙-酪肽(3),吲哚-3-乙酸(4)。它们的结构通过波谱方法得到确定。化合物1为首次从该海洋真菌中分离发现,化合物2为首次从该海洋微生物中分离发现。药理实验结果表明,化合物1对人鼻咽癌细胞株KB和人鼻咽癌细胞耐药株KBv200的IC50均小于0.78μg/ml。Four compounds, apicidin（ 1 ） , N-methylharman（ 2 ） , cylo （Phe-Tyr） （ 3 ） and indole-3-acetic acid （4） were isolated from the mangrove endophytic fungus ZZF42 from the South China Sea. Their structures were elucidated by spectral data. Compound 1 was first isolated from the marine fungus. Compound 2 was firstly isolated from marine microorganism. Compound 1 exhibited selective in vitro cytotoxicity towards KB and KBv200 with ICs0 values of less than 0. 78μg/ml.国家863科技攻关计划(2001AA624010);国家自然科学基金(20072058);广东省自然科学重点基金(021732

Influence of salinity and day and night rhythm on feeding rate(FR) of Ruditapes philippinarum

在实验室条件下 ,用流水系统测定盐度和昼夜节律对菲律宾蛤仔摄食率的影响 .分别对 1 5、2 0、2 5、3 0、3 5这 5个盐度梯度 ,以及连续 2 4h的 0 0 :0 0、0 4:0 0、0 8:0 0、1 2 :0 0、1 6:0 0、2 0 :0 0这 6个时间点下菲律宾蛤仔的摄食率进行了测定 .结果表明 :在1 5～ 2 5的盐度范围内 ,蛤仔的摄食率随着盐度的升高而增大 ,在盐度 2 5时达到最大 ,而在 2 5～ 3 5盐度范围内随盐度的增加而减小 ;在一个昼夜里 ,蛤仔的摄食率存在显著的差异 ,夜间的摄食率明显高于白昼 ,0 0 :0 0和 1 2 :0 0分别是两个极值 ;菲律宾蛤仔是一个有着明显昼夜节律性的底栖动物 ,并且对盐度有一个适应范围 ,盐度 2 5～ 3 0是其最适的盐度 .本实验为以后进一步研究菲律宾蛤仔在贝类混养虾池中的作用奠定了基础 .The FR of Ruditapes philippinarum was determined at salinity of 15‰,20‰,25‰,30‰,35‰ and 00:00,04:00,08:00,12:00,16:00,20:00, in consecutive 24 hours. The results showed that the FR of Ruditapes was significantly high at salinity of 25‰ to 30‰,low at other salinity. Difference also showed in the experiments of day and night rhythm. The FR in mid-night(24:00) was extreme high and mid-noon's(12:00) FR was the lowest. It appeared that Ruditapes philippinarum is a species of mollusk with day and night rhythm feeding behavior. That salinity of 25‰ to 30‰ was suitable to Ruditapes philippinarum's can also be concluded. This work will do good for further research to make clear what role Ruditapes philippinarum played in composite-cultivating shrimp-ponds.福建省“重中之重”基金项

Metabolites of Mangrove Endophytic Fungus ZSU-H19 from South China Sea

对南海红树林内生真菌ZSU-H19代谢产物进行研究,从菌体中分离得到6个化合物,现代谱学方法分析表明它们是:ophioglonin(1)、ophioglonin-7-O-β-D-glucopyranoside(2)、吲哚-3-乙酸(3)、尿囊素(4)、环(酪氨酰-亮氨酸)(5)、环(色氨酰-丙氨酸)(6),其中1和2为首次从微生物中分离发现。初步药理活性显示,1和2对人鼻咽癌细胞株KB显示微弱抑制活性,IC50分别为3.0×10-2和1.0×10-2g/L。国家自然科学基金资助项目(20072058,20572136);广西自然科学基金资助项目(0832081);广西民族大学科学研究基金资助项

sicpmg复合材料的制备及其阻尼特性研究

采用搅拌铸造法在真空度为200Pa的条件下制备得到含有微量氧化物的SiCp/Mg复合材料,通过显微组织观察和动态热机械分析等对其阻尼特性进行了研究。结果表明,所制备的SiCp/Mg复合材料基体晶界处分布着附着有氧化物的网状结构,且随着SiCp含量的增加,网状结构增多,且分布更加分散。此结构增大了位错密度和晶粒界面滑移,位错脱钉和界面滑移在振动过程中耗能量增大,因此所制备的SiCp/Mg复合材料具有理想的阻尼性能

sicpmg复合材料的制备及其阻尼特性研究

采用搅拌铸造法在真空度为200Pa的条件下制备得到含有微量氧化物的SiCp/Mg复合材料,通过显微组织观察和动态热机械分析等对其阻尼特性进行了研究。结果表明,所制备的SiCp/Mg复合材料基体晶界处分布着附着有氧化物的网状结构,且随着SiCp含量的增加,网状结构增多,且分布更加分散。此结构增大了位错密度和晶粒界面滑移,位错脱钉和界面滑移在振动过程中耗能量增大,因此所制备的SiCp/Mg复合材料具有理想的阻尼性能

Uptake and accumulation of microplastics in a cereal plant wheat

Microplastics pollution is becoming a global environmental concern, and growing evidence has demonstrated the accumulation and distribution of microplastics in terrestrial ecosystems. Once entering into soil, microplastics can change the physical, chemical and biological properties of soil, and then affect the growth of plants. Currently, most attentions have focused on the toxic effects of microplastics on terrestrial plants, only very limited report showed the uptake of microplastics by higher plants under hydroponic culture conditions. The nutrient solution is useful in understanding the mechanism of microplastics uptake, however, it does not account for the importance of affecting factors in the real environment (e.g., the presence of soil organic matter) and therefore do not represent the actual uptake of microplastics in the real-world. Here, we aim to determine whether wheat plants growing in a sand matrix are able to take up 0.2 mum polystyrene (PS) microbeads and translocate these particles from roots to shoots. Wheat was chosen as a representative of cereal crops because it is one of the main staple foods worldwide. A simple and rapid approach for the imaging of fluorescently labelled PS microbeads within plant tissues by confocal laser scanning microscope (CLSM) was used to investigate the uptake, accumulation, translocation and distribution of microspheres in the wheat plant. Two different fluorescent dyes were encapsulated into the PS microbeads matrix and they were used to detect the localization of PS beads in the root and the green tissue respectively. The presence of PS microbeads in plant tissue was then verified using scanning electron microscopy (SEM). Confocal images revealed that the PS luminescence signals were mainly located in the vascular system and on the cell walls of the cortex tissue of the wheat seedling roots after exposure in sand matrix with a concentration of 0.5 g kg~(-1) of PS beads for 21 d, indicated that the beads passed through the intercellular space via the apoplastic transport system. Microbeads clusters were observed in the intercellular space of epidermal tissues and the steles by SEM. Once inside the central cylinder, the 0.2 mum PS beads were transferred from the roots to the stems and leaves via the vascular system. Here, for the first time, we provide evidence of the adherence, uptake, accumulation, and translocation of submicrometer (0.2 mum) PS within the cereal plant in real sand matrix. Our findings provide a methodology and scientific basis for study of the accumulation mechanism of microplastics in soil-crop systems and their potential risk in food chain transfer