首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   61篇
  免费   2篇
  国内免费   25篇
  2020年   3篇
  2019年   2篇
  2015年   2篇
  2014年   2篇
  2013年   2篇
  2012年   2篇
  2011年   2篇
  2010年   2篇
  2009年   2篇
  2008年   3篇
  2007年   3篇
  2006年   4篇
  2005年   6篇
  2004年   1篇
  2003年   4篇
  2002年   7篇
  2001年   6篇
  2000年   5篇
  1999年   3篇
  1997年   5篇
  1996年   3篇
  1995年   3篇
  1994年   2篇
  1993年   3篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1985年   2篇
  1980年   1篇
  1979年   1篇
  1972年   1篇
排序方式: 共有88条查询结果,搜索用时 812 毫秒
61.
In 1986–88, 46 poisonings (4 of which were fatal) caused by amatoxin mushroom were reported. The fatalities were males aged between 7 and 65 years. They all had gastrointestinal symptoms and three of the patients died of acute hepatic insufficiency. The fourth died as a result of an intestinal perforation. The clinical and pathological alterations are compared with the findings of other authors.  相似文献   
62.
西藏地区已知鹅膏菌属(Amanita)真菌28种。西藏东南部的生态环境有利于该属种类的繁殖生长,约有90%以上的种集中分布在这里,同时反映了十分明显的垂直分布和对高山的适应特征。绝大多数种分布在海拔2500~3500m的森林带。另外该属全部种均属树木的外生菌根菌。本文还将鹅膏菌属的菌托初步划分为袋状型(Saccate type)、浅杯型(Vadosocupulatetype)、领口型(Collared type)、颗粒型(易碎型Granulate type)、小托型(Microvolvate type)、粉托型(Pulverulent type)等六种类型,并简要讨论了各种菌托类型与所处生态环境的适应性。  相似文献   
63.
Kinetics of electron-donor oxidation, storage-polymer formation and growth were studied in continuous cultures ofChromatium under conditions of balanced growth as well as during transient states.Under steady-state conditions, glycogen was accumulated at all dilution rates. This observation is consistent with previously postulated ideas about an ineffective glycogen-synthesis regulation.Upon perturbing the steady states, brought about by injection of extra sulfide into steady-state cultures, the following phenomena were observed immediately, irrespective of the dilution rate: the specific rate of sulfide oxidation increased to the value found in batch cultures, the sulfur-oxidation rate was decreased, the specific glycogen-synthesis rate increased, the increment being higher the lower the dilution rate, but an increase in the specific growth rate, if any, was below the limit of detection. The inverse relationship between the specific rates of glycogen synthesis and growth after removing the substrate limitation is to be explained by a shortage of intermediates, rather than by a growth-rate dependent intrinsic glycogen-synthesis limitation, because upon complete inhibition of growth a further increase in the rate of glycogen synthesis was observed. Essayed in this way, identical glycogen-synthesis rates were found at all dilution rates.Competitive advantages of such an apparently not adapted metabolism in environments with diurnal fluctuations in substrate concentrations are discussed.Non-Standard Abbreviations Nc cell nitrogen - TS total sugar - PHB poly--hydroxybutyrate - D dilution rate - SR reservoir concentration of the growth-limiting substrate - CAP chloramphenicol  相似文献   
64.
65.
舒畅  陶文沂  周荼 《微生物学报》2007,26(2):284-288
研究了致命鹅膏中的毒素在安全剂量下抑制小鼠皮肤肿瘤的效果,并对此毒素的药用安全性进行初步评价。采用经典的DMBA/巴豆油诱导小鼠皮肤乳头状瘤形成的二阶段致癌模型,观察和评价致命鹅膏毒素在不同剂量下抑制肿瘤的效果,并且通过测定血清中氨基己糖的含量来判断对肝损伤的情况。结果表明,致命鹅膏毒素在某一低剂量下对DMBA/巴豆油诱导小鼠皮肤乳头状瘤有较好的治愈效果,且对小鼠肝脏无损伤,证明了致命鹅膏毒素可以较好地治疗皮肤癌。  相似文献   
66.
Understanding the patterns of biodiversity through time and space is a challenging task. However, phylogeny‐based macroevolutionary models allow us to account and measure many of the processes responsible for diversity buildup, namely speciation and extinction. The general latitudinal diversity gradient (LDG) is a well‐recognized pattern describing a decline in species richness from the equator polewards. Recent macroecological studies in ectomycorrhizal (EM) fungi have shown that their LDG is shifted, peaking at temperate rather than tropical latitudes. Here we investigate this phenomenon from a macroevolutionary perspective, focusing on a well‐sampled group of edible EM mushrooms from the genus Amanita—the Caesar's mushrooms, which follow similar diversity patterns. Our approach consisted in applying a suite of models including (1) nontrait‐dependent time‐varying diversification (Bayesian analysis of macroevolutionary mixtures [BAMM]), (2) continuous trait‐dependent diversification (quantitative‐state speciation and extinction [QuaSSE]), and (3) diversity‐dependent diversification. In short, results give strong support for high speciation rates at temperate latitudes (BAMM and QuaSSE). We also find some evidence for different diversity‐dependence thresholds in “temperate” and “tropical” subclades, and little differences in diversity due to extinction. We conclude that our analyses on the Caesar's mushrooms give further evidence of a temperate‐peaking LDG in EM fungi, highlighting the importance and the implications of macroevolutionary processes in explaining diversity gradients in microorganisms.  相似文献   
67.
四种剧毒鹅膏菌肽类毒素的HPLC分离与鉴定   总被引:1,自引:0,他引:1  
利用反相高效液相色谱(HPLC)、紫外吸收光谱、质谱分析了灰花纹鹅膏Amanitafuliginea,白毒鹅膏A.verna,鳞柄白毒鹅膏A.virosa,豹斑鹅膏A.pantherina等四种剧毒鹅膏菌的肽类毒素,结果表明:A.fuliginea、A.verna含有九种标样毒素中的七种。A.virosa含有标样中的五种;A.pantherina含有标样中的四种毒素。A.fuliginea的毒素含量最高,其中最重要的a-amanitin含量高达6788.2(g/g干子实体,是A.verna的4倍,β-amanitin含量(2633.8μg/g干子实体)是Averna的6倍。  相似文献   
68.
7种鹅膏菌属真菌肽类毒素的HPLC分析   总被引:1,自引:0,他引:1  
利用HPLC法对长白山地区分布的7种鹅膏属真菌成熟子实体中的α鹅膏毒肽(αamanitin)、β鹅膏毒肽(βamanitin)和鬼笔毒肽(phalloidin)的含量进行了测定。结果表明:芥橙黄鹅膏(Amanitasubjunquillea)和橙黄鹅膏(Amanitaaff.citrina)中均含有3种毒素,其中芥橙黄鹅膏的α鹅膏毒肽含量为2395.91μg/g、β鹅膏毒肽含量为1653.75μg/g和鬼笔毒肽含量为405.26μg/g;橙黄鹅膏的分别为1121μg/g、4244μg/g和9442μg/g。芥橙黄鹅膏白色变种(Amanitasubjunquilleavar.abla)中含有β鹅膏毒肽,其含量为614.00μg/g。其他5种鹅膏中均未检测到上述3种毒素。  相似文献   
69.
A Study of Cultural Bias in Field Guide Determinations of Mushroom Edibility Using the Iconic Mushroom, Amanita muscaria , as an Example. Mushroom field guides teach identification skills as well as provide information on the edible or toxic qualities of each species of wild mushroom. As such they function as modern-day village elders for an increasingly urban, nature-ignorant population. This paper identifies underlying cultural bias in the determination of mushroom edibility in English-language field guides, using the iconic mushroom, Amanita muscaria, as an example. We explore a selection of ethnographic and medical texts that report the use of A. muscaria as a food, and we accept parboiling as a safe method of detoxifying it for the dinner table. Mushroom field guides, however, almost universally label the mushroom as poisonous. We discuss the cultural underpinnings and literary form of mushroom field guides and demonstrate that they work within a mostly closed intellectual system that ironically shares many of the same limitations of cultural bias found in traditional folk cultures, but with the pretense of being modern and scientific. An erratum to this article can be found at  相似文献   
70.
采集并组织分离到块磷鹅膏Amanita spissa的纯培养菌丝。探讨了各种培养条件对块磷鹅膏菌丝生长的影响,实验结果表明,在28℃,pH 6.0,避光的条件下块磷鹅膏的菌丝体生长最好。液体反应器人工培养块磷鹅膏获得成功,其液体培养的菌丝体干重在摇瓶中为0.893g/L,在气升式反应器内可达到2.33g/L。固体斜面培养和气升式反应器液体培养的菌丝体的HPLC分析表明菌丝体内含有鹅膏毒肽,而不含有鬼笔毒肽。两种培养条件下菌丝体的-αamanitin毒素含量略有不同,固体斜面菌丝体为26.02μg/gDCW、反应器培养菌丝体为15.25μg/gDCW。通过抑芽法试验也证明固体和液体培养菌丝体中含有-αamanitin,且具有和子实体中-αamanitin相同的生物学活性。结果表明有可能通过液体大规模培养鹅膏菌丝体来生产鹅膏毒素。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号