氢化物原子荧光法测定人血、内脏及其它生态环境样中的硒

目前硒与生态环境和人体健康的关系已非常引人注目，氢化物原子荧光光谱法(HGAFS)测血^[1]及土壤样^[2，3]中硒已有过报道。我们曾用本法分析过小白鼠肝胃中硒。最近应肿瘤治疗及预防之需，研究了人体全血，膀胱病灶和病周组织中硒的测定。从土壤植物标样的分析数据及与催化极谱法测硒的对照结果看，方法可行。     

鼠尾藻中褐藻多酚化合物的抑菌活性研究

采用平板生长抑制法对鼠尾藻(SargassumthunbergiiKuntze)中多酚化合物的抑菌活性进行研究。结果表明,在一定浓度范围内试样对除大肠杆菌外的受试菌均有较明显的抑菌活性,抑菌活性的大小与多酚浓度和分子质量密切相关。其中,透析内液对溶藻胶弧菌(Vibrioalginolyticus)和鳗弧菌(V.anguillarum)、透析外液对鳗弧菌和副溶血弧菌(V.parahaemolyticus)的抑制效果尤其明显。     

三沙市发展海洋生物质能源构想

文章介绍了大型海藻作为一种新的生物质能源,生长速度快、繁殖周期短,不与粮争地,对农产品的产量和价格没有影响,所以以大型海藻为主的生物质能成为生物质能研究的新焦点。大型海藻对水环境的适应能力强,对维持海洋生态系统的平衡有很重要的意义。分析和探讨在三沙市海域进行大型海藻养殖,可以充分利用海洋资源,发展新能源。     

中国发现最古老灵长类动物化石距今5500万年

正新浪科技讯北京时间6月10日消息,据国外媒体报道,科学家在中国长江流域发现世界上最古老的灵长类动物化石,距今5500万年。这种灵长类动物被命名为"阿喀琉斯基猴",体型很小,还不及侏儒鼠狐猴,可以放在手掌上。侏儒鼠狐猴是当前世界上最小的灵长类动物。在《自然》杂志上,科学家对这种最古老灵长类动物的骨架进行了描述。     

荣成俚岛野生鼠尾藻资源调查

2014年4月至2015年2月对荣成俚岛湾鼠尾藻(Sargassum thunbergii)的生长情况进行了调查。实验设计采用样方法观测了鼠尾藻体长结构的季节变化和繁殖特性。结果表明,(1)鼠尾藻一年有一次繁殖季节,有性繁殖盛期在6月下旬至7月下旬;(2)不同潮带间的主枝平均长度由大到小依次为低潮带、中潮带和高潮带,并且低潮带的SGR最大值出现的时间较中潮带和高潮带早;(3)在6月和7月体长结构组成最丰富。     

鼠尾藻和小珊瑚藻对赤潮异弯藻克生效应的初步研究

通过共培养的方法,比较了鼠尾藻(Surgassum thunbergii)和小珊瑚藻(Corallina pilulifera)新鲜组织、干粉末、水溶性抽提液、培养水的过滤液对赤潮异弯藻(Heterosigam akashiwo)生长的克生效应。结果表明,鼠尾藻和小珊瑚藻的新鲜组织对赤潮异弯藻的生长都具有显著的抑制作用;与鼠尾藻相比,小珊瑚藻的抑制作用更强。2种大型海藻的干粉末在2个高浓度(1.2,2.4 g.L-1)时对赤潮异弯藻的生长都产生了抑制作用,小珊瑚藻的抑制作用更为明显。2种大型海藻高浓度的水溶性抽提液(24 g.L-1)在实验的48 h内使赤潮异弯藻完全致死。在2种大型海藻培养水过滤液对赤潮异弯藻的作用实验中,在一次性添加方式下,小珊瑚藻的培养水过滤液对赤潮异弯藻的生长没有表现出明显的抑制作用,而在半连续添加方式下,却显著抑制了赤潮异弯藻的生长。与小珊瑚藻相比,无论在一次性还是在半连续添加方式下,鼠尾藻的培养水过滤液对赤潮异弯藻的生长都没有显示出显著的抑制作用。     

天然矿物的药用价值

雄黄又名"薰黄"、"石黄"、"鸡冠石"等,成书于西汉末年的医书《神农本草经》最早把矿物作为药剂,其中就包括雄黄,书中写道:"雄黄味苦平,主寒热、鼠瘘、恶疮、疽痔、死肌,杀精物、恶鬼、邪气、百虫毒,胜五兵。"由此可见,古人很早就已经知道,作为一种天然产出的矿物,雄黄具有解毒、杀虫、除恶疮的功效,可治疗疮痛、蛇虫咬伤、疟疾寒热等病症。     

Soil Erosion and Vegetation Succession in Alpine Kobresia Steppe Meadow Caused by Plateau Pika A Case Study of Nagqu County, Tibet

This paper evaluated the impacts of mounds created by the plateau pika (Ochotona curzoniae) on the vege- tation composition, structure, and species diversity of an alpine Kobresia steppe meadow in Nagqu County, Tibet Autonomous Region, China. Based on mound height or the depth of erosion pit, we defined five stages of erosion and compared the floristic features of communities at these stages with those in undisturbed sites. In the study area, the mounds and pits covered up to 7% of the total area. Lancea tibetica, Lamiophlomis rotata, and Potentilla bifurca were the dominant species in erosion pits, and Kobresia pygmaea, the dominant species in undisturbed sites, became a com- panion species in eroded areas. In the process of erosion, the original vegetation was covered by soil ejected by the pika, then the mounds were gradually eroded by wind and rain, and finally erosion pits formed. The vegetation coverage in- creased with increasing erosion stages but remained significantly lower than that in undisturbed sites. Improved coverage eventually reduced soil erosion, and pit depth eventually stabilized at around 20cm. Aboveground biomass increased with increasing erosion stage, but the proportion of low-quality forage reached more than 94%. The richness index and Shannon-Wiener index increased significantly with increasing erosion stage, but the richness index in mound and pit areas was significantly lower than that in undisturbed sites.     

Paliurus (Paliureae,Rhamnaceae) from the Miocene of East China and its Macrofossil-based Phylogenetic and Phytogeographical History

The extant genus Paliurus Miller is divided into P. ramosissimus and P. spina-christi groups and is diagnostically characterized by distinctive orbicular-winged fruits with a trilocular （or often bilocular） ovary and basally triveined leaves with a subentire to serrate margin. Here, structurally preserved winged fruits and associated compressed leaves of Paliurus （Paliureae, Rhamnaceae） are reported from the Middle-Upper Miocene Shengxian Formation of Tiantai, Zhejiang, eastern China. The fruits can be identified as Paliurus microcarpa Xiang-Chuan Lisp. nov., the diagnostic characters of external morphology and anatomy of which differ from those of both extant and fossil generic members; the leaves can be designated as Paliurus sp. The species based on winged fruits, P. microcarpa, might represent an ancient intermediate link exclusively known across the P. ramosissimus and P. spina-christi groups, showing a closer affinity to the P. ramosissimus group based on the resemblant smaller fruits with a narrower wing, and to the P. spina-christi group based on the similar wing structure and texture, respectively. Morphological analyses of the present and previous fossil fruit records around the world indicate that diversification of Paliurus had begun in northern transpacific regions by the Late Eocene. The macrofossil records, i.e., fruits and leaves of Paliurus globally when projected on paleoenvironmental maps in view of changing continental positions through time （from Eocene to Miocene） display that the past distribution of the genus was much wider than the present and belongs to a tropical and warm temperate realm of the Northern Hemisphere. Therefore, the modern restricted disjunction in tropical and warm temperate regions of East Asia and South Europe （even eastwards West Asia） might represent glacial refugia for some of the generic ancient lineages to survive severe cold at least since the terminal Pliocene.