FISH检测快速诊断曲霉菌感染的临床价值

目的探讨荧光原位杂交技术(FISH)检测曲霉菌感染的可行性和特异性,以期早期病原学诊断临床真菌感染。方法采用地高辛末端标记的18S-1寡核苷酸探针与27例经HE及PAS染色诊断为可疑真菌感染的石蜡包埋组织切片进行FISH检测。结果 HE及PAS染色可疑真菌感染分别为23例和27例。27例可疑真菌感染标本14例检出FISH阳性信号。结果 FISH可以特异性地检测出组织石蜡切片中的曲霉菌,设计不同菌属探针进行靶DNA杂交可以快速检测各种临床标本中的真菌感染,从而作为IFI早期病原学诊断的一种新策略。     

Inertia effects on characterization of dynamic response of brain tissue

Modeling and simulation of traumatic brain injury (TBI) resulted from collision or blast loading requires characterization of mechanical response over a wide range of loading rates under valid testing conditions. In this study, mechanical response of fresh bovine brain tissue was studied using the two modified Kolsky bar techniques. Radial deformation behavior of annular specimens, which are typically used to characterize the dynamic uniaxial compressive response of biological tissues, was examined using a modified Kolsky bar and a high speed camera to collect images while the specimen deforms at an axial strain rate of 2000s(-1). The high-speed images revealed inhomogeneous specimen deformation possibly brought about by radial inertia and causing a multi-axial stress state. To acquire valid stress-strain results that can be used to produce constitutive behavior of the soft materials, a novel torsion technique was developed to obtain pure shear response at dynamic loading rates. Experimental results show clear differences in the material response using the two methods. These results indicate that the previously demonstrated annular specimen geometry aimed at reducing inertia induced stress components for high rate soft materials uniaxial-compressive testing may still possess a significant component of radial inertia induced radial stress which consequently caused the observed inhomogeneous deformation in brain tissue test samples.     

Bacterial succession during 500?years of soil development under agricultural use

Soil bacterial succession under intensive anthropogenic disturbances is not well known. Using terminal restriction fragment length polymorphisms and 454 pyrosequencing of 16S rRNA genes, this study investigated how soil bacterial diversity and community structure changed under two agricultural land uses (paddy rice and upland cropping) in relation to soil development along a 500-year chronosequence created by intermittent reclamation of estuarine salt marshes. Multivariate analysis revealed orderly changes in soil physicochemical properties and bacterial community structure with time, confirming the occurrence of soil development and bacterial succession. Patterns of soil development and bacterial succession resembled each other, with recent land uses affecting their trajectories but not the overall direction. Succession of bacterial community structure was mainly associated with changes in ??-Proteobacteria and Verrucomicrobia. Two stages of bacterial succession were observed, a dramatic-succession stage during the first several decades when bacterial diversity increased evidently and bacterial community structure changed rapidly, and a long gradual-succession stage that lasted for centuries. Canonical correspondence analysis identified soil Na⁺, potentially mineralizable nitrogen, total phosphorous, and crystallinity of iron oxyhydrates as potential environmental drivers of bacterial succession. To conclude, orderly succession of soil bacterial communities occurred along with the long-term development of agroecosystems, which in turn was associated with soil physicochemical changes over time.     

中国东北落叶松属植物分类学特征的分析Ⅰ——球果形态的地理变异

从中国东北的大兴安岭、小兴安岭、张广才岭及长白山地区采集落叶松球果进行了测定分析,结果表明:大兴安岭和小兴岭的落叶松球果,其形态多呈椭圆形,相对稳定,变异较小。张广才岭和长白山的落叶松球果多呈广卵形和卵形,变异较大。球果的长度和宽度性状较不稳定,不宜作为东北地区落叶松属内种间分类的依据。     

融合蛋白与病毒入膜机制研究进展

包膜病毒感染细胞的第一步即病毒与靶细胞膜的融合,它由病毒包膜上的融合蛋白诱发,融合蛋白与受体分子相互作用后暴露出融合肽,它伸向靶膜使两膜紧密接近后,多肽周围的脂质分子进一步重排,通过中间态最后发生融合,本文将介绍近年来病毒融合蛋白及入膜机制研究进展。     

鳜血清免疫球蛋白的分离纯化及其亚单位分子量的测定

免疫球蛋白(Immunoglobulin,Ig)在脊椎动物体液免疫中起着十分重要的作用.近年来,鱼类屹的研究已受到免疫学家的广泛关注。大多数硬骨鱼类只发现有一种Ig,类似于哺乳动物的IgM,但不是五聚体,而是由8条重链(H链)和8条轻链(L链)组成的四聚体.然而,IgM的结构在不同鱼类甚至同一种鱼的不同部位(如血液、粘液和胆汁等)有所差异。       

6-苄基腺嘌呤和激动素对香石竹切花衰老的生理效应

6-苄基腺嘌呤（6-BA）和激动素（KT）均能改善香石竹切花体内的水分平衡,增加切花的鲜重,增大花径,提高过氧化物酶（POD）活性,延缓可溶性蛋白质含量下降以及丙二醛（MDA）含量和O2^-·于生成速率的增加,延长切花瓶插寿命2～3d。     

有机铬对实验性糖尿病大鼠胰岛β细胞形态结构及功能的影响

目的探讨有机铬(2-吡啶甲酸铬)对大鼠胰岛β细胞形态结构及内分泌功能的影响。方法首先通过尾静脉注射新鲜配制的1.5%四氧嘧啶溶液制备糖尿病大鼠模型;通过灌胃的方式提高糖尿病大鼠体内有机铬含量;治疗12周后,通过氧化酶法测定大鼠血清葡萄糖水平,利用免疫组织化学方法和放射免疫学方法分别观察大鼠胰岛β细胞形态结构的改变及大鼠血清胰岛素含量的变化。结果两治疗组大鼠血清葡萄糖水平明显下降,与糖尿病模型组相比,差异均有显著性;400μg治疗组大鼠体内胰岛素水平明显升高,与糖尿病模型组相比差异有显著性,而200μg治疗组大鼠血清胰岛素水平虽有所增加但与糖尿病组相比,差异无显著性;免疫组化显示治疗组大鼠胰岛β细胞数量增多,胞质内胰岛素免疫反应阳性颗粒明显增多。结论有机铬对糖尿病大鼠具有明显的降低血糖功能,并能促进受损胰岛及β细胞形态结构功能的恢复,对糖尿病大鼠病理状态具有明显的改善作用。     

不同营养条件对金鱼藻净化作用及其生理生态的影响

以沉水植物金鱼藻（Ceratophyllum demersum）为研究对象,研究了较高营养条件（N:1030 mg/L,P:13 mg/L）对金鱼藻去除氮、磷能力的影响,金鱼藻的含磷量、生物量与净光合作用速率对营养负荷的响应。结果表明,金鱼藻-沉积物处理系统可有效去除氮、磷（去除率80%以上）,但去除效率随水中营养盐浓度的升高而下降。试验结束时各试验组金鱼藻总磷含量达7.0113.09 mg/g （平均9.03 mg/g）,显著高于对照组（2.853.17 mg/g,平均3.05 mg/g）,表明金鱼藻可以吸收水体中的磷。营养盐对金鱼藻生长有明显抑制,其抑制作用随营养盐浓度增高而加剧,除对照组外,各试验组金鱼藻均有叶片脱落,试验结束时金鱼藻生物量降至初始生物量的48.3%63.3%。在较高营养水体中,金鱼藻的净光合作用速率由试验开始时-0.0370.058 mg/（gh）显著上升至试验结束时0.180.44 mg/（gh）,而对照组变化不大,这表明在试验后期,随着水体营养盐浓度降低,金鱼藻开始进行恢复性生长,说明水体营养盐浓度对金鱼藻的净光合作用速率和生长速率有明显影响。金鱼藻尚不适宜作为滇池草海生态修复的先锋物种。