鳖、蛙及鲢免疫组织中两种不同淋巴细胞的分布

国家“淡水生态和生物技术”重点实验室;湖北省自然科学基金;国家自然科学基金

鳜消化器官的组织学观察

“八五”国家科技攻关项目85-908-01-03-02

三种有机磷萃取剂对水生生物的毒性效应

通过３种有机磷萃取剂：甲基磷酸二仲辛酯（Ｐ３５０）、异辛基磷酸单异辛酯（Ｐ５０７）和磷酸二异辛酸（Ｐ２０４）对不同营养级水平的单种生物：藻类（斜生棚藻）、草履虫（尾草履虫）、类（大型）、鱼类（鱼苗）的毒性试验，结果表明：３种有机磷萃取剂的毒性效应浓度（半致死浓度或半抑制浓度）为Ｐ３５０：０．４０～９．３０ｍｇ／Ｌ，Ｐ５０７：２３．３２～１１２．００ｍｇ／Ｌ，Ｐ２０４：５９．５０～１３８．００ｍｇ／Ｌ；毒性强弱的顺序为Ｐ３５０＞Ｐ５０７＞Ｐ２０４；建议把Ｐ３５０、Ｐ５０７、Ｐ２０４在水体中的安全浓度暂分别定

钩虾体内寄生棘头虫幼虫在中国的首次报道

钩虾体内寄生棘头虫幼虫在中国的首次报道聂品（中国科学院水生生物研究所，武汉４３００７２）ＴＨＥＦＩＲＳＴＦＩＮＤＩＮＧＯＦＣＹＳＴＡＣＡＮＴＨＳＯＦＡＮＡＣＡＮＴＨＯＣＥＰＨＡＬＡＮＩＮＧＡＭＭＡＲＵＳＳＰ．ＩＮＣＨＩＮＡ￥ＮｉｃＰｉｎ（Ｉｎｓｔｉｔ...

Variables affecting melanoidins removal from molasses wastewater by coagulation/flocculation

Coagulation/flocculation process was applied in the polishing treatment of molasses wastewater on a bench-scale. Important operating variables, including coagulant type and dosage, solution pH, rapid mixing conditions as well as the type and dosage of polyeletrolytes were investigated based on the maximum removal efficiencies of chemical oxygen demand (COD) and color, residual turbidity and settling characteristics of flocs. HPSEC was utilized to evaluate the removal of molecular weight fractions of melanoidins-dominated organic compounds. Experimental results indicate that ferric chloride was the most effective among the conventional coagulants, achieving 89% COD and 98% color eliminations; while aluminum sulfate was the least effective, giving COD and color reductions of 66% and 86%, respectively. In addition to metal cations, counter-ions exert significant influence on the coagulation performance since Cl--based metal salts attained better removal efficiency than SO42--based ones at the optimal coagulant dosages. Coagulation of molasses effluent is a highly pH-dependent process, with better removal efficiency achieved at lower pH levels. Rapid mixing intensity, rather than rapid mixing time, has relatively strong influence on the settling characteristics of flocs formed. Lowering mixing intensity resulted in increasing settling rate but the accumulation of floating flocs. When used as coagulant aids, synthetic polyelectrolytes showed little effects on the improvement in organic removal. On the other hand, cationic polyacrylamide was observed to substantially enhance the settleability of flocs as compared to anionic polyacrylamide. The effects of rapid mixing conditions and polymer flocculants on the coagulation performance were discussed. (C) 2009 Elsevier B.V. All rights reserved.

Ultraviolet-B exposure induces photo-oxidative damage and subsequent repair strategies in a desert cyanobacterium Microcoleus vaginatus Gom.

Biological soil crusts are important in reversing desertification. Ultraviolet radiation, however, may be detrimental for the development of soil crusts. The cyanobacterium Microcoleus vaginatus can be a dominant species occurring in desert soil crusts all over the world. To investigate the physico-chemical consequences of ultraviolet-B radiation on M. vaginatus, eight parameters including the contents of chlorophyll a, reactive oxygen species, malondialdehyde and proline, as well as the activities of photosynthesis, superoxide dismutase (EC 1.15.1.1), peroxiclase (EC 1.11.1.7) and catalase (EC 1.11.1.6) were determined. As shown by the results of determinations, ultraviolet-B radiation caused decreases both in contents of chlorophyll a and in ratios of variable fluorescence over maximum fluorescence that indicate the growth and photosynthesis of M. vaginatus, besides, increases both in levels of reactive oxygen species and in contents of malondialdehyde and proline, while intensified activities of superoxide dismutase, peroxiclase and catalase reflecting the abilities of enzymatic preventive substances to oxidative stress of the treated cells. Therefore, ultraviolet-B radiation affects the growth of M. vaginatus and leads to oxidative stress in cells. Under ultraviolet-B radiation, the treated cells can improve their antioxidant abilities to alleviate oxidative injury. The change trends of reactive oxygen species, superoxide dismutase, peroxiclase and catalase are synchronous. These results suggest that a balance between the antioxidant system and the reactive oxygen species content may be one part of a complex stress response pathway in which multiple environmental factors including ultraviolet-B radiation affect the Survival of M. vaginatus. (C) 2009 Elsevier Masson SAS. All rights reserved.

Changes in biomechanical properties of the coronary artery wall contribute to maintained contractile responses to endothelin-1 in atherosclerosis.

AIMS: Our aim was to determine whether alterations in biomechanical properties of human diseased compared to normal coronary artery contribute to changes in artery responsiveness to endothelin-1 in atherosclerosis. MAIN METHODS: Concentration-response curves were constructed to endothelin-1 in normal and diseased coronary artery. The passive mechanical properties of arteries were determined using tensile ring tests from which finite element models of passive mechanical properties of both groups were created. Finite element modelling of artery endothelin-1 responses was then performed. KEY FINDINGS: Maximum responses to endothelin-1 were significantly attenuated in diseased (27±3 mN, n=55) compared to normal (38±2 mN, n=68) artery, although this remained over 70% of control. There was no difference in potency (pD2 control=8.03±0.06; pD2 diseased=7.98±0.06). Finite element modelling of tensile ring tests resulted in hyperelastic shear modulus μ=2004±410 Pa and hardening exponent α=22.8±2.2 for normal wall and μ=2464±1075 Pa and α=38.3±6.7 for plaque tissue and distensibility of diseased vessels was decreased. Finite element modelling of active properties of both groups resulted in higher muscle contractile strain (represented by thermal reactivity) of the atherosclerotic artery model than the normal artery model. The models suggest that a change in muscle response to endothelin-1 occurs in atherosclerotic artery to increase its distensibility towards that seen in normal artery. SIGNIFICANCE: Our data suggest that an adaptation occurs in medial smooth muscle of atherosclerotic coronary artery to maintain distensibility of the vessel wall in the presence of endothelin-1. This may contribute to the vasospastic effect of locally increased endothelin-1 production that is reported in this condition.

1-mm gate periphery AlGaN/AIN/GaN HEMTs on SiC with output power of 9.39 W at 8 GHz

AlGaN/AlN/GaN high electron mobility transistor (HEMT) structures with high mobility GaN channel layer were grown on 50 min diameter semi-insulating (SI) 6H-SiC substrates by metalorganic chemical vapor deposition and large periphery HEMT devices were fabricated and characterized. High two-dimensional electron gas mobility of 2215 cm(2)/V s at room temperature with sheet electron concentration of 1.044 x 10(13)/cm(2) was achieved. The 50 mm diameter HEMT wafer exhibited a low average sheet resistance of 251.0 Omega/square, with the resistance uniformity of 2.02%. Atomic force microscopy measurements revealed a smooth AlGaN surface with a root-mean-square roughness of 0.27 nm for a scan area of 5 mu mi x 5 pm. The 1-mm gate width devices fabricated using the materials demonstrated a very high continuous wave output power of 9.39 W at 8 GHz, with a power added efficiency of 46.2% and power gain of 7.54 dB. A maximum drain current density of 1300 mA/mm, an extrinsic transconductance of 382 mS/mm, a current gain cutoff frequency of 31 GHz and a maximum frequency of oscillation 60 GHz were also achieved in the same devices. (C) 2007 Elsevier Ltd. All rights reserved.

Controllable growth of semiconductor nanometer structures

Self-assembled quantum dots and wires were obtained in the InxGa1-xAs/GaAs and InAs/In0.52Al0.48As/InP systems, respectively, using molecular beam epitaxy (MBE). Uniformity in the distribution, density, and spatial ordering of the nanostructures can be controlled to some extent by adjusting and optimizing the MBE growth parameters. In addition, some interesting observation on the InAs wire alignment on InP(001) is discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.

一种任务优先级的综合设计方法

提出了一种基于优先级表设计的调度算法.将任务的相对截止期和空闲时间这两个特征参数结合起来,综合设计任务的优先级表,使得截止期越早或空闲时间越短,任务的优先级越高,而且任务的优先级由相对截止期和空闲时间惟一确定.对于任意一个任务,可通过对设计的优先级表进行二元多点插值获得相应任务的惟一优先级.与传统的EDF和LSF算法进行仿真比较,仿真结果表明,通过优先级表设计方法来确定任务的优先级,提高了任务调度的成功率,降低了任务截止期的错失率.该方法可应用于实时系统中实时任务的动态调度中.

中国汉族人群若干疾病相关基因的定位研究

1. 中国一个轴前多指 II/III 型家系候选基因的定位 轴前多指（PPD）是人类众多肢体异常症状中比较常见的一种。前人的研 究把它定位到染色体7q36 上450Kb 的区段内。在这个候选区段内，不同的遗传 背景的几个多指家系的致病突变已被发现，它们位于SHH 基因的顺式调控元件 （ZRS）上，这个调控元件调控SHH 正常的时空表达，对指/趾的正常发育起着 重要的作用。在本研究之中，我们分析了我国一个大的多指家系，这个家系的多 指疾病的遗传方式是常染色体显性遗传并有接近100%的疾病外显率。通过连锁 分析和单倍型构建，我们把这个家系的致病基因定位到染色体7q36 上微卫星标 记D7S2465 和 D7S2423 之间1.7cM 的区域内，这个区域包含了上述的450Kb。 为了确定这个家系的致病突变，我们采用了直接测序的方法，筛查了我们定位的 这个区段内的5 个基因（HLXB9, C7orf2, NOM1, RNF32 和C7orf4）的编码区， SHH 基因的ZRS，C7orf2 基因的第5 内含子，和18 个在多物种中保守的非编码 区段（CNS）。我们的结果表明，在这个中国多指家系中，不是上述的5 个基因 和18 个多物种中保守非编码区段（CNS）的突变导致了多指的表型，也不是其 他研究小组报道的SHH 基因的ZRS 突变导致了多指表型。是否在我们界定的这 1.7cM 的候选区段内还存在着SHH 基因的其他调控元件，它的突变也一样会引 起SHH 基因异常的时空表达，最终导致多指表型的产生还需要进一步的研究来 证实。 2. 中国一个单纯性小眼球家系致病基因的定位 先天性小眼球是一种在临床上具有异质性的眼球发育异常疾病，表型从单 侧眼球体积变小到两侧眼球组织的完全缺失。单纯性小眼球疾病指的是除了眼球 的异常不伴随身体其他组织的异常，其遗传学上的致病机理到目前为止还未完全 清楚。之前的研究表明，不同遗传背景的小眼球家系的致病基因被定位到完全不 同的染色体区段上。本研究中的这个中国单纯性小眼球家系，具有常染色体显性的遗传方式，而且是第一个在分子水平上被研究的中国小眼球家系。为了研究这 个家系的致病基因，我们使用了382 个微卫星标记对这个家系进行了全基因组的 扫描，结果表明这个中国小眼球家系的致病基因定位于2 号染色体长臂上，这个 结果不同于以往报道的任何其他小眼球家系。两点连锁分析在重组率为0 时在微 卫星标记D2S2265 上得到最大值3.290，单倍型分析表明所有的受累个体在染色 体2q11-14 上微卫星标记D2S1890 和 D2S347 之间共享相同的单倍型，所以将 这个家系的致病基因定位到染色体2q11-14 上15 cM 的区段内。我们的结果进一 步提示了小眼球疾病的遗传异质性，并且定位了一个新的关于眼球发育的相关基 因。 3. 19 号染色体C 型凝集素家族与中国南方汉族人群的SARS 易感性研究 2003 年SARS 在全球爆发时，不同的个体在感染后表现出不同的病程和 最终的治疗结果，这被认为是个体本身的遗传因素在这个过程中起了一定的作 用，即不同个体在一些基因上的多态影响了他们对一些疾病的易感性。CD209L 基因是19 号染色体上C 型凝集素家族中的一员，它被证明是SARS 病毒的受体， 并且它的第4 外显子的VNTR 多态被认为和宿主对病毒的易感性有关。但是这 个结论在其后其他两个研究小组的工作未被得到证实。可能的原因有：(1) CD209L 基因本身的多态和宿主对SARS 病毒的易感性无关，而是和它紧密连锁 的其它基因的多态发挥真正的作用；(2)可能是由于以前未检测到的群体分层现 象的存在，使最初的研究得到了一个假阳性的结果。为了探讨这个问题，我们对 19 号染色体上C 型凝集素家族的4 个成员(FCER2, CLEC4G, CD209 和 CD209L) 作了全面的研究，我们采用了检测tagSNPs 的方法，在C 型凝集素家族基因簇上 选取了23 个tagSNPs 位点来代表这个基因簇的多态。我们检测了来自中国香港 的181 个SARS 病人和172 个匹配的正常对照，结果表明C 型凝集素家族的4 个基因跟中国南方汉族群体对SARS 病毒的易感之间没有相关性。同时我们检测 了来自中国不同地区的1145 个汉族样本CD209L 基因VNTR 的多态分布情况， 结果表明这个位点在中国人群中存在群体分层现象，这也解释了之前的研究小组 得到的假阳性结果可能正是由于他们忽略了这个问题而导致的

南海东沙西南海域冷泉碳酸盐岩特征及其意义

海底冷泉流体或自生碳酸盐沉积可为碳氢化合物（主要指常规油气或天然气水