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1.
本文采用生命表和数值模型分析等方法,对中国卤虫(Artemiasinica)的温度特性做了研究。1.孵化发育起始温度9.07℃,幼虫发育起始温度9.07℃。有效积温(℃·d)前者为0.921±0.979,后者为205.26±24.1,平均世代有效积温458.4±39.6。2.各项生命表参数均与温度呈显著的函数关系,其适温范围基本介于18─34℃,最适点介于26.5─28.5℃,种群增长倍数>2的温度范围在18─34℃。3.在山西盐池水域,该卤虫的年世代数为6.2±0.62个世代、第2─5个世代是种群生产力高峰期。在此期间种群的加倍时间<15d.内禀增长率>0.04d ̄(-1),因此资源开发价值最大  相似文献   

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烧伤猪肠道膜菌群的微生态失调研究   总被引:1,自引:1,他引:0  
本研究定量地分析了烧伤猪山莨菪碱治疗组和对照组的肠道粘膜及内容物中5类菌群,对内脏标本进行了细菌培养。其中治疗组猪的空肠膜菌群,肠杆菌的活菌计数(Lg10 ̄(x±s))为5.67±0.85,肠球菌为2.60±0.23,双歧杆菌为5.27±0.71,类杆菌为3.91±0.83,乳杆菌为2.20±0.13;回肠膜菌群中5类菌活菌计数分别为5.83±0.42,2.58±0.21,5.63±1.02,4.03±1.11,2.58±0.21,5.63±1.02,4.03±1.11,2.58±0.2;盲肠菌膜群依次为6.62±1.27,2.71±0.45,6.23±1.52,6.67±1.29,3.43±1.29;而盲肠内容物的5类菌数分别为8.05±0.31,3.57±0.65,7.78±0.62,6.91±0.96,5.44±1.98。内脏组织发生了细菌移位.对照组与治疗组都出现了微生态失调。结果显示山莨菪碱不能调整菌群失调症。  相似文献   

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应用草型塘模型生态系统研究化学品的整体生态效应   总被引:5,自引:1,他引:4  
本文叙述草型塘模型生态系统的结构、功能及应用于评价化学品引起生态效应的可能性。模型塘由8个3m×1m×1m(V=3m ̄3)的玻璃钢水槽组成。每个槽的底部铺设10cm厚的带有水生生物种子、孢子和卵子的河泥,灌注自来水,添加一定量的KNO_3和NaH_2PO_4.使起始氮、磷含量达到中-富营养水平。在室外自然光照条件下培养,实验历时4个多月。经1个多月的培养,各槽即形成结构复杂的沉水植物群落,除各种常见的沉水植物外,尚有多种藻类、浮游动物、底栖动物及微生物。各群落之间的相似性较好,藻类、浮游甲壳类及底栖动物多样性指数变异系数分别为17.7%、18.0%和36.0%。群落功能稳定,9月中旬各槽群落总产氧量平均为5.75±0.30g/m ̄2·d’P/R比值平均为1.26±0.07,二者的变异系数分别为5.2%和5.6%。经单甲脒农药污染影响实验,本模型生态系统中的群落结构及功能产生一系列明显反应。说明草型塘模型生态系统结构、功能比较复杂,稳定,可比性较强,对药物污染反应灵敏,是生态系统水平上生态效应评价的良好工具。  相似文献   

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本文对87例不明原因不育的男性患者的精液,进行了溶脲脲原体的分离,检出率为62.07%,而38例正常对照中,溶脲脲原体的检出率为18.42%,二者差别非常显著(P<0.001)。溶脲脲原体感染者精子的活动率与活动力同正常人相比,差异显著(P<0.05),提示溶脲脲原体感染与部分男性不育有关。  相似文献   

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牙龈卟啉单胞菌及其细胞外膜泡多克隆抗体的比较研究   总被引:1,自引:0,他引:1  
分别制备牙龈卟啉单胞菌47A- 1 及其膜泡的多克隆抗体,并用间接免疫荧光法对67 个临床标本进行检测。结果经统计学检验,两种抗体显著相关,P< 0.01 ,符合率为82.1 % ;膜泡抗体的检出率高于菌体抗体,P<0.05 ;膜泡抗体相对于菌体抗体的敏感性为93.5 % 。膜泡抗体与牙龈卟啉单胞菌以外的其他口腔细菌无交叉反应,说明膜泡抗体的特异性较强。  相似文献   

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姚素艳  张朝阳 《遗传学报》1994,21(3):188-192
1文报道雌鼠及雌雄性小鼠分别受到0.15-1.56Gt^60coγ-射线照射后,在不同时间进行同笼,取其胚胎观察形态、大小等并制备每个胚胎的染体标本。分析胚胎细胞染色体数目异常、结构畸变及显性致死效应。结果表明,染色体数目异常发生率与剂量呈直线关系。单纯雌鼠受到1.07Gy照射后观察到平衡易位携带者的再现率为0.99%。雌雄鼠均受到1.07及1.56Gy照射后观察到平衡易位携带者的再现率为0.99  相似文献   

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本实验采用四氧嘧啶损伤大鼠胰岛β细胞,复制糖尿病动物模型。若预先腹腔注射汉防己甲素(100mg/kg)则可完全预防引发的糖尿病。预防组血糖(7.63±0.44mmol/L)明显低于对照组(25.46±1.21mmol/L,P<0.001);血清胰岛素水平(11.33±1.97μU/ml)高于对照组(7.13±0.45μU/ml,P<0.05);血浆胰高血糖素(66.85±5.07pg/ml)明显低于对照组(90.35±3.15pg/ml,P<0.01).口服葡萄糖耐量实验显示预防组耐糖功能较对照组明显改善,糖耐量曲线下血糖面积预防组(29.45±1.63ml·h/L)低于对照组(113.28±5.02mmol·h/L,p<0.001)。胰岛β细胞免疫组织化学染色结果显示,预防组胰岛β细胞数目及胰岛素分泌颗粒的含量均与正常大鼠胰岛相同,无形态学改变,而对照组胰岛内β细胞免疫反应阳性产物减少甚至消失。结果表明,汉防己甲素对四氧嘧啶引起的胰岛β细胞急性损伤有保护作用。  相似文献   

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本文报道雌鼠及雌雄性小鼠分别受到0.15-1.56Gy~60Coγ-射线照射后,在不同时间进行同笼,取其胚胎观察形态、大小等并制备每个胚胎的染色体标本。分析胚胎细胞染色体数目异常、结构畸变及显性致死效应。结果表明,染色体数目异常发生率与剂量呈直线关系。单纯雌鼠受到1.07Gy照射后观察到平衡易位携带者的再现率为0.99%。雌雄鼠均受到1.07及1.56Gy照射后其F_1子代中平衡易位携带者的再现率皆为0.32%。雌雄鼠均受照射组中的显性致死率明显高于雌鼠受照射组,且剂量效应关系为直线相关  相似文献   

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低压值下体负压(LBNP)可仅使心肺压力感受器卸荷。采用-2kPaLBNP实验结果表明:LBNP既不引起动脉血压变化,也不引起心率改变,但却引起基础胸阻抗(Z。)从对照的21.8±0.4升高到22.5±0.5Ω(P<0.01),前臂血管阻力(FVR)从12.3±0.9升高到19.9±1.4U(P<0.01),前臂血流(FBF)从对照时7.1±0.5降低到4.3±0.3ml·min ̄(-1)·100ml ̄(-1),心率变异性谱(HRV)未发生任何变化,即心肺压力感受器卸荷时心脏自主神经活动水平与均衡性不受影响。由于FVR和FBF的变化可间接反映外周血管交感传出活动水平,上述实验结果提示,心肺压力感受器对外周血管及心脏自主神经活动的调节可能存在机能分化现象。  相似文献   

10.
Acetobacter xylinum生产纤维素的最适培养基成分   总被引:10,自引:0,他引:10  
探索出胶醋杆菌在摇瓶培养最适培养基成分为蛋白胨浓度1.0%、酵母膏0.5%、葡萄糖浓度2.0%、柠檬酸0.115%、乙醇1%、Na2HPO40.5%,pH6.0,160r/min的条件下进行摇瓶培养,细菌纤维素最大产量为7.55g/l。  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

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Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

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Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.  相似文献   

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正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases  相似文献   

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