我国人粒细胞无形体病的研究进展

人粒细胞无形体病是由嗜吞噬细胞无形体引起的一种经蜱传播的人畜共患病。近年来,在美国、欧洲、非洲等地均有相关病例报道,我国也有病例发现。该病主要引起发热,血小板减少,严重可引起多脏器损害,甚至死亡。因此日益受到研究者们的关注与重视。本文分别从HGA的发现,临床特点,治疗,预防等方面介绍人粒细胞无形体病的研究进展。     

定量评价天敌昆虫控害功能的稳定同位素方法

天敌在区域性多作物农田景观系统中辗转捕食害虫,对调节和控制害虫种群数量发挥着非常重要的作用。明确天敌昆虫的食物来源和扩散规律是定量评价其控害功能的重要环节。其中,稳定同位素标记方法是追溯生物个体的食物来源和探究其运动规律的重要手段。本文首先介绍该标记方法的基本原理,接着以天敌昆虫龟纹瓢虫Propylea japonica(Thunberg)为例,应用稳定同位素碳标记方法追溯其在棉花和玉米农田景观系统中取食来源与食物比例;最后叙述了稳定同位素方法的应用前景和存在的问题。     

冬小麦原生质体培养的胚状体直接发生

冬小麦品种“京花一号”胚性愈伤组织在改良的N₆培养基(NBD培养基)上继代得到易碎型胚性愈伤组织,转入改良MS液体培养基(MSDL培养基)后得到胚性悬浮系,分离的原生质体在改良的MS培养基(MSDP培养基)上培养,再生细胞直接产生体细胞胚胎,并再生出完整植株。体细胞胚胎形成过程与小麦合子胚的形成过程十分相似。     

Bt毒蛋白Cry1Ac在人造土壤中对赤子爱胜蚓毒理及生化影响

Bt毒素能通过转基因作物的花粉、根和残株进入土壤.为评估转基因作物对土壤动物的影响,本文模拟转基因棉的Bt毒素进入土壤的发生程度,用含不同浓度Bt毒蛋白Cry1Ac的人造土壤处理蚯蚓,测定蚯蚓存活率、重量变化及体内总蛋白含量和过氧化氢酶(CAT)、乙酰胆碱酯酶(AchE)、谷胱甘肽-S-转移酶(GST)和纤维素酶活性.结果表明,Bt毒蛋白对蚯蚓的生物量和生理水平影响均不明显,不存在急毒性和亚致死毒性影响,对蚯蚓比较安全.     

The age of the 20 meter Solo River terrace, Java, Indonesia and the survival of Homo erectus in Asia

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35-50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report (40)Ar/(39)Ar incremental heating analyses and new ESR/U-series age estimates from the "20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The (40)Ar/(39)Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/-17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and (40)Ar/(39)Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted.     

猴头菌丝多糖降血糖作用研究

目的:研究猴头菌丝多糖的降血糖作用。方法:以液体发酵生产的猴头菌丝体为原料,经热水浸提、浓缩、酒精沉淀获得菌丝粗多糖;以常规降糖药物格列本脲为阳性治疗对照,通过四氧嘧啶诱发小鼠糖尿病的预防试验,比较猴头菌丝多糖各剂量与格列本脲的降血糖效果。结果:猴头菌丝多糖得率为7.14%,粗多糖再经Sevage法去除蛋白质,获得猴头菌丝精多糖(HMP),得率为10.92%;猴头多糖高、中、低三个剂量均能有效的对抗四氧嘧啶诱发的高血糖;其中,高剂量的降血糖作用与格列本脲相比,差异极显著。结论:猴头菌丝多糖对四氧嘧啶型高血糖模型小鼠有降血糖作用,作用效果优于格列本脲,对糖尿病小鼠的胰腺具有一定的保护作用。     

我国主要类型昆虫对CO_2升高响应的研究进展

大气CO2浓度增加已经受到国内外的极大关注。自2002年以来,在自行设计、组装的一系列密闭式动态CO2气室和开顶式CO2浓度控制箱基础上,研究了我国主要类型昆虫对CO2浓度升高响应的特征。结果显示,大气CO2浓度升高降低了棉铃虫Helicoverpa armigera的适合度和对棉花的危害作用,增加了棉花对棉铃虫为害的补偿作用,使以咀嚼式口器昆虫为代表的棉铃虫种群发生与危害下降;但大气CO2浓度升高改变了植物组织营养物质的组成与含量,提高了蚜虫Aphis gosypii对氨基酸营养的利用与补偿效率,降低了3种麦蚜的种间竞争,导致蚜虫种群发生与危害严重;而对烟粉虱Bemisia tabaci的种群特征影响较少。大气CO2浓度升高对天敌昆虫的影响存在种的特异性,表现出种群上升、下降和变化不大等特征。未来大气CO2浓度升高下,由于作物生长发育加快,生物量增加,蚜虫种群增多,导致吡虫啉农药防治效果下降,由此未来大气CO2浓度升高下农民将被迫使用更多的化学农药防治蚜虫类害虫,进而加重环境污染。     

40多年来塔南策勒绿洲动态变化研究

 利用策勒绿洲1956、1990和1998年3个不同时期的遥感数据（航片、TM和SPOT）进行配准、解译与分类处理,比较分析绿洲40多年来的动态变化,并从自然和人为因素两个方面探讨绿洲变化的原因。结果表明,从1956年到1998年策勒绿洲西北部的景观格局发生了显著变化,绿洲面积增加了近20％;林地的分布明显改变;河道发生显著位移,据实地调查大约向北移动400 m。对1990年TM与1998年SPOT分类数据,用FRAGSTATS软件计算景观格局指数并比较分析,发现研究区的绿洲、绿洲 荒漠交错带、荒漠和沙丘4种景观类型发生了明显的变化。绿洲面积增加而斑块数减少了近一半;交错带面积减少而斑块数增加了35％;荒漠面积减少而斑块数增加了60％;沙丘面积基本没有变化但斑块数减少了20％。绿洲变化的总体趋势是人工绿洲的面积增大而绿洲 荒漠交错带的面积明显减少,同时整个绿洲的破碎度增加而连通性降低,绿洲的稳定性和自我调节的功能下降。     

人乳头瘤病毒特异性T细胞系细胞冻存后细胞的存活率及功能

研究人乳头瘤病毒特异性T细胞系细胞冻存后细胞的存活率及功能。应用包含10%二甲基亚砜、90%小牛血清的冻存液冻存6个T细胞系(5个CD4 T细胞系,1个CD8 T细胞系)细胞,液氮中冻存32~54个月后复苏,台盼蓝染色法检测复苏后T细胞系细胞的存活率,用酶联免疫斑点法(enzyme-linked immunospot assay,ELISPOT)检测复苏后T细胞系细胞的功能。结果显示,6个T细胞系细胞液氮冻存解冻后细胞的存活率为24.7%~93.5%,过夜培养后细胞的存活率为2.5%~72.2%。CD8 T细胞系细胞的存活率高于CD4 T细胞系细胞。6个复苏后的T细胞系细胞在PHA诱导后均能分泌IFN-γ。人乳头瘤病毒特异性T细胞系细胞冻存复苏后能够保持较好的存活率和功能。     

Dynamic micro-geographic and temporal genetic diversity in vertebrates: the case of lake-spawning populations of brown trout (Salmo trutta)

Conservation of species should be based on knowledge of effective population sizes and understanding of how breeding tactics and selection of recruitment habitats lead to genetic structuring. In the stream‐spawning and genetically diverse brown trout, spawning and rearing areas may be restricted source habitats. Spatio–temporal genetic variability patterns were studied in brown trout occupying three lakes characterized by restricted stream habitat but high recruitment levels. This suggested non‐typical lake‐spawning, potentially representing additional spatio–temporal genetic variation in continuous habitats. Three years of sampling documented presence of young‐of‐the‐year cohorts in littoral lake areas with groundwater inflow, confirming lake‐spawning trout in all three lakes. Nine microsatellite markers assayed across 901 young‐of‐the‐year individuals indicated overall substantial genetic differentiation in space and time. Nested gene diversity analyses revealed highly significant (≤P = 0.002) differentiation on all hierarchical levels, represented by regional lakes (F_LT = 0.281), stream vs. lake habitat within regional lakes (F_HL = 0.045), sample site within habitats (F_SH = 0.010), and cohorts within sample sites (F_CS = 0.016). Genetic structuring was, however, different among lakes. It was more pronounced in a natural lake, which exhibited temporally stable structuring both between two lake‐spawning populations and between lake‐ and stream spawners. Hence, it is demonstrated that lake‐spawning brown trout form genetically distinct populations and may significantly contribute to genetic diversity. In another lake, differentiation was substantial between stream‐ and lake‐spawning populations but not within habitat. In the third lake, there was less apparent spatial or temporal genetic structuring. Calculation of effective population sizes suggested small spawning populations in general, both within streams and lakes, and indicates that the presence of lake‐spawning populations tended to reduce genetic drift in the total (meta‐) population of the lake.