镧系元素对海水小球藻的毒性效应

用评价化学品对藻类毒性的标准实验方法,研究了12种镧系元素对小球藻生长的抑制情况。结果表明,12种镧系元素抑制小球藻生长的96h半效应浓度(96h EC50 )均为2 9 0 0±0 5 0 μmol·L-1。对各剂量反应方程进行X2 检验,结果表明,符合精度要求,计算出的96h EC50 真实可靠。镧系元素对海水小球藻的生物毒性是相同的,此结果对探明镧系元素对藻类的生态毒理效应具有重要意义。     

Cannabis sativa: volatile compounds from pollen and entire male and female plants of two variants, Northern Lights and Hawaian Indica

Sixty-eight compounds were identified by coupled gas chromatography and mass spectrometry (GC-MS) in the chemosphere of Cannabis sativa L. pollen and entire male and female plants of two cultivated varieties, Northern Lights and Hawaian Indica. Twenty-one and 28 substances, respectively, were present in pollen of the two forms. To conserve the natural composition of volatiles a delicate headspace method was employed. The two varieties represent different chemotypes which distinguish themselves, in the main quantitatively, in the setup of volatiles from pollen and entire male and female plants. Twenty compounds were monoterpenes, including the five major components: β-myrcene (E)-β-ocimene, terpinolene, β-pinene and limonene; 25 were sesquiterpenes, and the other 23 were of mixed biogenetic origin, including 3-methyl-1-butanol and benzylalcohol which occurred only in pollen; two pyrazines occurred only in Northern Lights females. Besides being of interest in natural products chemistry, the results should have relevance for plant systematics and for the pharmaceutical and technical applications of Cannabis . We demonstrate that the pollen has a distinct chemical character in possessing two exclusive volatiles, while lacking seven compounds occurring in males and females of both variants.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 387–397.     

术前胸部CT检查对食管癌手术切除的价值

胸部CT不仅可作为一种诊断食管癌的辅助检查方法,而且对肿瘤的外浸程度、与周围器官关系、判断手术切除可能性能提供有价值的参考依据,弥补上消化道钡透及纤维胃镜检查的不足.随着相关领域研究的不断深入,术前胸部CT对食管癌的可切除判断的参考价值也越发重要与可靠,我们就术前胸部CT检查对食管癌手术切除做一综述.     

Mass changes in migrating birds: the evidence for fat and protein storage re-examined

The fact that one cannot kill a bird twice makes it very difficult to determine the relative contributions of fat and non-fat components to increases in body mass before migratory flights in individual birds. Knowing the relative contributions of these components is of obvious energetic interest since fat yields about eight times as much energy as fat-free muscle tissue. Several recent studies have failed to demonstrate convincingly, due to flaws in their analyses, that fat-free mass in addition to fat is accumulated before long-distance flights. We point out that regressions of fat or the non-fat component on total body mass cannot yield reliable estimates of the composition of individual mass changes in view of inter-individual variation in structural size, reserve levels or timing of storage. We suggest that studies over time of synchronous populations or marked individuals will give better answers. A re-analysis of published data indicates the widespread existence of fat-free tissue deposition during migration, whereas in some species fat alone explained the increase in total body mass. Larger species tend to incorporate a relatively higher proportion of non-fat components when increasing in mass. However, the comparative data set is not yet of sufficient quality to allow general statements on why, and to what extent in different individuals and species, non-fat tissue in addition to fat is deposited before take-off on migratory flights.     

ABCB_1基因C3435T多态性与耐药性癫痫的关系

目的：探讨中国粤西地区汉族人群ABCB1基因C3435T（rs1045642）的单核苷酸多态性与耐药性癫痫的关系。方法：研究对象128例,包括正常对照组60例和癫痫组68例。根据患者对抗癫痫药物的反应性将癫痫组分为耐药组（30例）和药物敏感组（38例）。提取所有研究对象外周血基因组DNA,采用PCR扩增后基因测序鉴定ABCB1基因C3435T多态性。测定该位点基因型频率和等位基因频率,并进行统计学分析。结果：各组ABCB1基因C3435T基因型频率的分布符合Hardy-Weinburg平衡,提示其来自同一孟德尔群体。正常对照组与药物敏感组及耐药组,药物敏感组与耐药组间基因型频率比较,差异均无统计学意义（P〉0.05）。正常对照组与药物敏感组及耐药组,药物敏感组与耐药组间等位基因型频率比较,差异亦无统计学意义（P〉0.05）。结论：本研究结果初步证实ABCB1基因C3435T位点多态性分布与耐药性癫痫之间无相关性。     

根据外部形态特征试论披碱草属3组植物间的系统关系

通过对披碱草属中小颖组、宽颖组和长颖组种类外部形态的观察,总结了3组植物外部形态特征的异同,探讨了形态学特征的分类学意义。同时,根据3组植物外部形态性状—花序、小穗、小花、以及内稃的演化趋势,分析了各组的演化关系和系统位置。结果表明：小颖组最原始,宽颖组较进化,长颖组最高级;小颖组可能直接派生了较进化的宽颖组,并在宽颖组的基础上进而产生了最高级的长颖组。此外,本文对披碱草属参试种的系统关系也作了一定程度的探讨,结果显示圆锥披碱草最原始,墨西哥披碱草最进化,其余参试种居于两者之间。上述研究工作为整个披碱草属系统与进化方面的探讨提供了形态学方面的理论证据。     

小鼠心肌纤维化模型的制备及其胶原沉积的机制

目的 建立缺血性心肌纤维化小鼠模型并探讨其胶原沉积机制.方法 将BALB/c小鼠随机分为实验组和对照组,每组10只.实验组予以腹部皮下注射异丙肾上腺素50 ms/kg,每天2次,连续10 d.对照组同法注射生理盐水.对比体表心电图,45 d后处死小鼠,天狼猩红染色观察心脏Ⅰ、Ⅲ型胶原纤维含量,荧光定量PCR检测心脏基质金属蛋白酶9(MMP-9)、基质金属蛋白酶组织抑制剂一1(TIMP-1)基因表达,免疫组化染色分析心、肝、肾组织层粘连蛋白(LN)的表达.结果 实验组小鼠室性心律失常增多,心率加快(P<0.05);心脏胶原沉积较多,MMP-9、TIMP-1、LN表达上调(P<0.05),肝、肾组织LN无明显改变(P>0.05).结论 异丙肾上腺素能制备缺血性心肌纤维化小鼠模型,其机制与MMP-TIMP失衡有关.     

麻孢菌属的一个中国新记录种（英文）

从采自河南境内伏牛山的野生碎米桠中分离到1株内生真菌,经鉴定为麻孢菌属的中国新记录种——宇田川麻孢菌Gelasinospora udagawae,根据研究菌株对其进行了形态描述、显微照相及分析讨论。     

大白菜胞质雄性不育系RC7及其保持系的细胞学和蕾期基因表达差异分析

以大白菜雄性不育材料RC7及其保持系B7为材料,通过对两材料花药发育过程进行细胞学观察,并利用cDNA-AFLP技术分析两材料花蕾的基因表达差异,以明确RC7发生雄性败育的时期和方式,为大白菜CMS的分子机理研究提供依据。结果显示:(1)细胞学观察发现,大白菜雄性不育材料RC7及其保持系B7的小孢子母细胞减数分裂属同时型,小孢子在四分体中的排列属四面体型,保持系B7花药的绒毡层属于腺质型;不育材料RC7在四分体时期绒毡层细胞内出现大的液泡,呈现败育征兆,单核期绒毡层解体,中层退化,小孢子核开始解体、败育,属于单核花粉败育型。(2)对两材料蕾期基因的cDNA-AFLP差显比较分析表明,共获得了23条阳性差异片段,其中在不育系RC7花蕾中特异表达的有8条,在保持系B7花蕾中特异表达有10条,两系中共有条带5条。(3)对不育系中特异表达的8条谱带进行Blast搜索发现,H1与拟南芥光合反应蛋白基因有较高的一致性,H26与拟南芥钙调磷酸酶类磷酸酯酶家族蛋白质的部分序列存在90%的一致性,属于细胞信号转导基因;对来自保持系的10条谱带的差异片段功能以及一致性进行比对分类发现,它们包括糖代谢基因、蛋白质的合成与运输基因、乙烯诱导基因、电子传递和能量途径基因、未知或假定蛋白等。研究表明,大白菜雄性不育材料RC7可能是由于绒毡层细胞液泡化和径向肥大,小孢子受挤压后破裂降解,不能形成正常的成熟花粉粒而败育;乙烯诱导基因(H29)在保持系中特异表达,在不育系中沉默,表明不育系中缺乏乙烯相关基因。     

江西武宁地区二叠系瓜德鲁普统䗴类生物地层研究

在江西武宁的二叠系栖霞组、茅口组和龙潭组下部获得?类化石8属30种,并对其中10个属种进行系统描述。对获得的?类化石自下而上建立六个?带,分别是Schwagerina anhuiensis-Schwagerina chihsiaensis带、Schwagerina chihsianesis regularis带、Chusenella conicocylindrica带、Chusenella douvillei带、Chusenella ishanensis带和Pseudodoliolina pseudolepida带。通过与南京栖霞山,贵州盘县火铺镇等地的?类化石带对比,本研究区的栖霞组上部、茅口组和龙潭组中下部的地质时代分别为罗德期、沃德期和卡匹敦期。