Proteomic analysis of Bacillus cereus growing in liquid soil organic matter

Bacillus cereus is believed to be a soil bacterium, but studied solely in laboratory culture media. The aim of this study was to assess the physiology of B. cereus growing on soil organic matter by a proteomic approach. Cells were cultured to mid-exponential phase in soil extracted solubilized organic matter (SESOM), which mimics the nutrient composition of soil, and in Luria-Bertani broth as control. Silver staining of the two-dimensional gels revealed 234 proteins spots up-regulated when cells were growing in SESOM, with 201 protein spots down-regulated. Forty-three of these differentially expressed proteins were detected by Colloidal Coomassie staining and identified by matrix assisted laser desorption ionization-time of flight MS of tryptic digests. These differentially expressed proteins covered a range of functions, primarily amino acid, lipid, carbohydrate and nucleic acid metabolism. These results suggested growth on soil-associated carbohydrates, fatty acids and/or amino acids, concomitant with shifts in cellular structure.     

中亚热带红壤区油桐(Vernicia fordii)林冠水文效应特征

于从2004年7月到2005年9月,对南方红壤区油桐人工林的穿透雨、树干流和林冠截留的水文特征进行了监测,并对其影响因素进行初步分析,结果表明：在整个测定期间,油桐林穿透雨占总降雨量75.6%±8.6%,树干流占3.6%±1.1%,而截留量占20.8%±9.1%。油桐林冠对降雨的再分配受到降雨量和降雨强度的影响,随着雨量的增加,穿透雨、树干流和截留量相应地提高,并且树干流和截留量在高的雨量下逐渐趋于稳定;随着降雨强度的增加,穿透雨率逐渐升高,而树干流率和截留率降低。在不同雨量级间,油桐穿透雨具有显著性的差异,但树干流的差异不显著。油桐林下水分输入存在明显的空间异质性,穿透雨在不同观测点间具有显著性差异,靠近树干的林冠内部穿透雨低于林冠边缘,而且随着降雨量或降雨强度的增加,穿透雨的空间异质性(穿透雨率的变异系数CV)降低;树干流对降雨也具有明显的汇集作用,在树干周围输入的雨量是林外降雨量20~70倍,并且随着降雨量的增加,这种汇集效应（漏斗比率）先提高后降低。同时油桐单株树干流(cm³•mm^-1)与胸径、树高和冠层面积均呈显著正相关(p<0.05),但是与枝下高的相关性不显著(p>0.05)。     

Secretases as therapeutic targets for Alzheimer's disease

Accumulation of amyloid-β (Aβ) is widely accepted as the key instigator of Alzheimer’s disease (AD). The proposed mechanism is that accumulation of Aβ results in inflammatory responses, oxidative damages, neurofibrillary tangles and, subsequently, neuronal/synaptic dysfunction and neuronal loss. Given the critical role of Aβ in the disease process, the proteases that produce this peptide are obvious targets. The goal would be to develop drugs that can inhibit the activity of these targets. Protease inhibitors have proved very effective for treating other disorders such as AIDS and hypertension. Mutations in APP (amyloid-β precursor protein), which flanks the Aβ sequence, cause early-onset familial AD, and evidence has pointed to the APP-to-Aβ conversion as a possible therapeutic target. Therapies aimed at modifying Aβ-related processes aim higher up the cascade and are therefore more likely to be able to alter the progression of the disease. However, it is not yet fully known whether the increases in Aβ levels are merely a result of earlier events that were already causing the disease.     

银杏叶提取物对糖尿病大鼠心肌损伤的防护作用

目的:研究银杏叶提取物(EGb)对糖尿病大鼠心肌的防护作用.方法:用光镜和透射电镜观察EGb对糖尿病大鼠心肌的形态学改变,并测定心肌组织内超氧化物歧化酶(SOD)、一氧化氮合酶(NOS)、结构型一氧化氮合酶(cNOS)、诱导型一氧化氮合酶(iNOS)的活性及一氧化氮(NO)、丙二醛(MDA)的含量.结果:糖尿病大鼠心肌光镜下主要表现为心肌细胞空泡变性及心肌纤维局灶性溶解;电镜下主要表现为心肌线粒体肿胀,嵴变短,肌原纤维溶解;SOD活性下降,NOS、iNOS活性及MDA、NO含量增高.EGb治疗组病变明显减轻,EGb治疗组心肌组织内SOD活性明显高于糖尿病组,NOS、iNOS活性及MDA、NO含量低于糖尿病组.结论:EGb可能通过抗脂质过氧化作用和降低NO水平而对糖尿病心肌产生保护作用.     

Intentionally introduced species: more easily invited than removed

Alien species are brought into countries world wide on a massive scale for agricultural production, ex situ conservation, landscape aesthetics, gardens, and ecosystem restoration. Unfortunately, some of these species have escaped and adversely impacted on regional as well as global biodiversity conservation and agricultural production. To reduce such risks, it is necessary to implement specific and effective measures. Since various government departments and institutions are involved in the management of alien species, it is difficult to prevent native and agroecosystems from being invaded by invited species. We propose the establishment of a supervision and inspection continuum over intentional species introduction, similar to that which exists in some countries over unintentional species introductions. Namely, a justification of the necessity to import, a risk assessment, assurances as to provision of an adequate containment facility assessment, and a damage-limitation protocol should that need to be invoked. These requirements should be satisfied before an alien species is knowingly imported, and the necessary follow-up supervision is important post- importation.     

CO_2倍增对植物生长和土壤微生物生物量碳、氮的影响

关于大气ＣＯ２浓度倍增（即为７００μｍｏｌＣＯ２·ｍｏｌ－１空气）将对植物生长产生诸多影响,已有大量报道［１,２］。但ＣＯ２倍增对植物及所在土壤中微生物影响的研究甚少［３,４］。土壤微生物是陆地生态系统中最活跃的成分,担负着分解动植物残体的重要作用,...     

PCR快速检测伪狂犬病病毒野毒感染

根据已发表的伪狂犬病病毒(PrV)gE、gI基因的序列,设计并合成了一对引物,以PrV容A株细胞培养毒为模板,筛选最佳反应条件和试剂工作浓度,建立了区分PrV野毒株和疫苗弱毒的鉴别PCR方法。该方法能从PrV容A株(RA)、上海株(SH)、鲁A株(LA)中扩增出一条848bp的片段,但Bartha-K61株没有扩增出该片段。测序结果表明PCR扩增产物和方法的特异性。对正常细胞与其它6种引起猪病毒性疫病相关病毒进行检测,结果均为阴性,没有出现交叉反应。对PrV容A株细胞毒提取物DNA进行检测,其最低检出量为5pg。PCR对感染野毒的发病猪不同组织器官检测发现,淋巴结检出率最高,依次为脾、脑(海马角)、肺、肾、肝等。对2003～2004年期间江苏、浙江、安徽、福建、上海等省市的37个大中型猪场送检的172份病料进行PCR检测病料阳性率为20．34％(35／172),猪场阳性率为40.54％(15／37)。实验结果表明所建立的PCR技术可用于伪狂犬病野毒感染的快速鉴定和流行病学调查。     

菊花中一个新的多糖的研究

通过热水提取、离子交换层析和凝胶层析,从菊花(Chrysanthemum morifolium Ramat.)中分离得到一个新的多糖.根据糖组成分析、甲基化分析、高碘酸氧化、部分酸水解和NMR谱图分析,确定其结构如下:[→4)-Galp-(1→4)-Galp-(1→4)-Galp-(1→4)-Galp-(1→6)-Galp-(1]→F3L2Araf-(1→5)-Araf-(1→4)-Glcp-(1→4)-Glcp1→6 F3[→4)-Galp-(1→4)-Galp-(1→4)-Galp-(1→4)-Ga6p-(1→6)-Galp-(1]→n     

不同植被类型对土壤水蚀的影响

不同植被类型对土壤水蚀的影响因子是计算土壤水蚀速率以及选择适当土地利用方式的基本参数.本文以土壤侵蚀模型中的植被因子(C因子)为指标,研究不同植被类型对土壤水蚀的影响.根据6个水土保持试验项目33个小区共195个小区年的资料,计算了剌槐、柠条、沙棘、沙棘-杨树,沙棘-油松、沙打旺、红豆草、苜蓿和草木樨等9种林草植被因子值.林地植被因子介于0.004到0.164之间,以刺槐林的C值最低.草地植被因子介于0.071到0.377之间,以第一年的草木樨C值为最高.定量对比说明林草植被的水土保持效益明显优于农作物.本项研究结果可以用于定量比较不同植被类型覆盖下的土壤流失速率,对于北方农牧交错带退耕还林还草政策的实施具有参考价值.