嘉陵江8种鱼类不同组织微量元素含量分析

测定了黄颡鱼（Pelteobagrus fulvidraco）、中华倒刺钯（Spinibarbus sinensis）、大鳍鲠（Mystus macropterus）、长吻鲍（Leiocassis longirostris）、大眼鳜（Siniperca kneri）、小口鲇（Silurus asotus）、岩原鲤（Procypris rabaudi）和圆口铜鱼（Coreius guichenoti）8种嘉陵江名贵鱼不同组织微量元素含量及肌肉和脑中Ca、P含量,结果表明,鱼脑中各类矿物质元素显著高于肌肉;肌肉5种微量元素总量由低到高依次为：圆口铜鱼、中华倒刺鳃、长吻鲍、大鳍鲮、黄颡鱼、大眼鳜、岩原鲤、小口鲇;而脑由低到高依次为：大眼鳜、岩原鲤、小口鲇、圆口铜鱼、大鳍鲢、中华倒刺鳃、长吻鲍、黄颡鱼。微量元素在各内脏器官的分布：铁和铜以肝（胰）脏最高,肾脏其次,胃肠最低;锰和锌的含量肾脏〉肝（胰）脏〉胃肠;镁的分布各种鱼差异较大。     

三峡水库蓄水初期鱼体汞含量及其水生食物链累积特征

于2011-2012年在三峡库区干流水域及7条典型支流采集了11种鱼类样品,以稳定同位素(δ13C和δ15N)营养等级分析为基础,研究了三峡水库蓄水后的鱼类汞含量水平及其食物链累积特征.结果表明,库区鱼类(以鲤为例)平均总汞含量为57.1 μg/kg,与蓄水前鱼体总汞水平相当,但在库区不同水域鱼体总汞含量差异显著:干流入库水域(洛碛断面)鱼体总汞含量平均值为88.0μg/kg,显著高于水库腹区水域(巫山断面)的平均值43.1μg/kg.稳定同位素分析表明,库区支流鱼体的δ13C范围为-22.08‰--28.92‰,大于干流鱼体的δ13C范围(-23.11‰--26.87‰),表明支流鱼类的食物来源具有更明显的湖沼型特征.同时,支流鱼类食物链上汞的累积放大效率显著高于干流水域.水文水动力差异可能是库区内汞累积等生态过程存在空间差异的重要原因.     

长江三峡库区江段沉积物的重金属污染特征

测定了三峡库区江段沉积物中２１个元素的含量,比例比配统计分析指出,重庆至涪陵江段的沉积物样品间无明显相关,涪陵至巴陵段的沉积物间在９０％置信水平上显著相关;沉积物中钙、镁、锶、钡、铁、钴、镍、镉、锰、锌、铝、钒、镧、钇、钛等元素间在９０％置信水平上有显著相关,伸砷、镉、铜、汞、铜、磷等元素间以及它们与上述元素间无显著相关,这表明涪陵以上江段的沉积物因受重庆和长春污染影响大,样品间的相似性小,而涪陵     

长江朱杨江段和沱江富顺江段鱼类体内16种多环芳烃的含量

于2010年9-11月在长江朱杨江段采集到9种鱼类标本, 分别为瓦氏黄颡鱼(Pelteobagrus vachelli Richardson)、圆筒吻 (Rhinogobio cylindricus Gnther)、鲤(Cyprinus carpio Linnaeus)、鲫(Carassius auratus Linnaeus)、大眼鳜(Siniperca kneri Garman)、铜鱼(Coreius heterodon Bleeker)、圆口铜鱼(Coreius guichenoti Sauvage et Dabry)、大鳍鳠(Mystus macropterus Bleeker)和鲇(Silurus asotus Linnaeus); 在该江段上游支流沱江富顺江段采集到6种鱼类标本, 分别为鲫、黄颡鱼(Pelteobagrus fulvidraco Richardson)、鲤、大眼鳜、大鳍鳠和鲇, 每种鱼的样本量为6-11尾, 共计192尾。采用快速溶剂萃取及气相色谱法对鱼体中的16种多环芳烃(PAHs)含量进行了检测。结果显示, 在两个江段的各种鱼体样本中均检测到了多种多环芳烃的存在。在长江干流朱杨江段所采集到的9种鱼中瓦氏黄颡鱼体内多环芳烃总量(PAHs)最高, 其含量为(2803.78 215.37) ng/g; 鲇鱼体内PAHs最低, 其含量为(515.8638.80) ng/g。在沱江富顺江段采集到的6种鱼中鲫体内PAHs最高, 为(8498.571128.22) ng/g; 鲇鱼体内PAHs最低, 其含量为(1295.0569.69) ng/g。采集自长江朱杨段和沱江富顺段两采集地的相同种类有5种, 富顺段5种鱼体内PAHs均高于朱杨段同种类鱼体内的含量; 除大眼鳜外, 其余4种鱼的差异均达到显著水平。富顺江段鱼类体内高分子量多环芳烃比例较高, 而朱杨江段鱼类体内富集的低分子量多环芳烃和中分子量多环芳烃的比例较高。通过讨论认为, 长江朱杨段及其支流沱江富顺段的鱼体均受到了多环芳烃的污染, 并且沱江鱼类受多环芳烃的污染程度高于长江干流朱杨段鱼类。此外, 沱江富顺段鱼体所含的高分子量多环芳烃组成百分比高于长江干流朱杨段的鱼体, 但其中、低分子量多环芳烃组成百分比相对于干流鱼类较低, 可能的原因是两个江段多环芳烃的污染源不同。       

水库鱼体汞积累的预测

回归分析表明,在所研究的长江流域的１２个水库中,水库与河流鲤鱼汞含量的比值Ｆ与水库集水面积Ａ和径流量Ｑ的比值呈显著的同相关：Ｆ＝２．５０９６－０．４８０４７Ａ／Ｑ（ｒ＝－０．７９５,ｎ＝１２）凤滩水库调查结果证实了此回归方程的可靠性。实测的Ｆ值与预测值比较,相对误差为２３．１％。用此模型预测三峡大坝建成蓄水后将加剧鱼体对汞的生物富集作用,局部水域存在鱼体汞含量超过我国食品汞含量标准的可能性。本文讨     

贵州百花湖鱼体汞污染现状

以西南汞污染严重的贵州百花湖为对象,选取湖中优势鱼、贝类,通过测定其总汞和甲基汞含量,并结合水体、沉积物汞含量和相关水质参数,探讨了百花湖鱼类汞污染的现状及其影响因素.百花湖鱼体总汞平均含量为28.0ng·g-1,变化范围为4.2～143ng·g-1;甲基汞的平均含量为10.9ng·g-1,变化范围为3.0～39.3ng·g-1.虽然百花湖遭受上游贵州有机化工厂含汞废水的严重污染,但鱼体汞含量并没有超过国家食品卫生标准.其主要原因可能是:百花湖的鱼主要是人工养殖的草食性或杂食性鱼类,鱼龄较小,且其摄取的食物汞含量低、食物链简单,不利于汞的富集;其次,其较快的生长速度对鱼体汞具有生物稀释的作用.     

长江三峡库区鱼类资源现状的研究

1997－2000年在长江三峡库区的巴南和万州江段共监测1292船次,统计 渔获物4096．38kg,生物学测定2464尾,共采集鱼类30种,分属8科24属,目前库区渔获物组成和结构与20世纪70年代相比发生了较大变化,白甲鱼,中华倒刺靶,岩原鲤等在渔获物中比较已经很少,铜鱼资源也明显下降,Gua,Gan,鳊等在渔获物中已基本消失,而南方鲇,鲤,黄颡鱼等比较相对上升,渔获物中高龄鱼个体减少,低龄鱼及幼鱼个体比重增加,与70年代资料相比,三峡库区鱼区资源已呈衰退趋势。     

岩原鲤消化能力和营养价值的初步研究

用常规方法测得岩原鲤（Procyprisrabaudi）比肠长222±0．251,比内脏重0．0743±0．00752,比肝胰重0.0294±0.007711,比肠重0.0243±0．00591。体重与体长关系为：y＝0．02635X2.977,肠道前部pH值68-70,中部8－9,后部7.0－7．6,岩原鲤消化道器官组织具有较高的蛋白酶和淀粉酶活力,活力大小顺序对蛋白酶和淀粉酸在肠道均为前肠＜中肠＜后肠。岩原鲤含肉率73．9±025％,肌肉粗蛋白质75.9±3.0％,粗脂肪14.4±4．33％,肌肉必需氨基酸组成与必需氨基酸指数分析结果表明,岩原鲤为淡水鱼类中营养价值最好的一种鱼。     

瓣结鱼含肉率及肌肉脂肪酸、矿质元素的分析

本文测定和分析了瓣结鱼的含肉率及肌肉中脂肪酸和矿质元素组成。结果表明,瓣结鱼平均含肉率为66．91％。瓣结鱼肌肉中共有14种脂肪酸。其中饱和脂肪酸为5种,平均质量分数为39．49％;不饱和脂肪酸有9种,质量分数平均值为58．83％。瓣结鱼肌肉9种矿质元素中,钙等常量元素的平均含量在116．35mg／100g～1313．33mg／100g之间,而铜等微量元素含量的平均值则在0．19mg／100g～5．20mg／100g之间。瓣结鱼肌肉平均钙磷比为1：4．31。相关分析表明,瓣结鱼的含肉率及肌肉中脂肪酸和矿质元素随其生长变化显著。t-检验表明,瓣结龟肌肉中脂肪酸和矿质元素在清水江标本和都柳江标本之间存在着显著性差异。     

三峡水库蓄水后铜鱼和圆口铜鱼肌肉和肝脏中重金属水平

为了解三峡水库蓄水后鱼体重金属富集现状及其潜在的生态风险和食品安全, 测定了三峡水库上、中、下游不同年龄组铜鱼(Coreius heterodon)和圆口铜鱼(C. guichenoti)肌肉和肝脏中重金属含量。利用等离子吸收光谱法、石墨炉原子吸收光谱法、原子荧光光谱法检测样品中Cu、Zn、Cr、Pb、Cd、Hg、As 等 7种重金属含量。结果表明: 7 种重金属在铜鱼和圆口铜鱼体内的含量水平基本一致, 重金属在铜鱼和圆口铜鱼肌肉中含量大小均为Zn Cu Cr Hg AsPb Cd, 在铜鱼肝脏中含量大小为Zn Cu Pb Cd Cr As Hg, 而在圆口铜鱼肝脏中含量大小为Zn Cu Pb Cr Cd Hg As。铜鱼和圆口铜鱼肝脏中重金属含量显著高于肌肉(P0.05)。两种鱼类间大部分重金属在库区上、中、下游无显著差异(P 0.05)。铜鱼和圆口铜鱼肌肉(可食用部分)中7 种重金属含量均未超过国家食品安全卫生标准, 属于安全食用范围;肝脏中除Cd 和Pb 外的其他元素含量均未超过国家标准。相关结果反映了三峡水库175 m 蓄水后底栖土著经济鱼类重金属的污染状况, 对了解该地区水产品质量安全状况及水产品安全评价提供了参考依据。       

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.