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   46篇
  完全免费   1篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2014年   3篇
  2013年   4篇
  2012年   3篇
  2011年   3篇
  2010年   5篇
  2009年   1篇
  2008年   5篇
  2007年   3篇
  2006年   6篇
  2005年   4篇
  2003年   2篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1995年   1篇
  1987年   1篇
排序方式: 共有47条查询结果,搜索用时 31 毫秒
1.
中国北京地区的多孔菌   总被引:9,自引:1,他引:8       下载免费PDF全文
戴玉成  袁海生  贺伟  Cony  DECOCK 《菌物学报》2006,25(3):368-373
本文报道产于中国北方北京地区的非褶菌目孔状真菌72种,并列出了每种的寄主。其中大部分种类为该地区首次报道。王氏薄孔菌为一新种,它的主要特征为子实体平伏反转,孔口表面奶油色至浅黄色,担孢子圆柱型并略弯曲,生长在李属树木上。该新种与垫状薄孔菌相似,但后者孢子较宽且是完全平伏的种类。  相似文献
2.
De novo cholesterol synthesis and hexose monophosphate (HMP) shunt were studied in rat kidney stimulated to proliferate by a single administration of lead nitrate. Lead-treated rat kidneys showed an increase in DNA synthesis, as measured by [3H]thymidine incorporation starting at 18 h and with a maximum at 24 h. Renal DNA synthesis was preceded by an increase in de novo cholesterol synthesis and an enhancement in the activity of the HMP shunt, as indicated by increased activity of G6PDH and 6PGDH. These findings indicate that enhancement of cholesterol synthesis and of the HMP shunt is closely associated with the active proliferative process induced in the kidney by treatment with lead nitrate.  相似文献
3.
Ophiostoma arduennense sp. nov. is described from several cultures isolated from Fagus sylvatica in southern Belgium. The species is mainly characterized by globose perithecia with small button-like bases ornamented with brown hyphal hairs of variable length and, long cylindrical necks ending in ostiolate hyphae. It is homothallic with small reniform ascospores and no apparent anamorph. It is closely associated with the ambrosia beetles Xyloterus domesticus and X. signatus. Its phylogenetic relationships within Ophiostoma are discussed and the species is compared with other Ophiostoma species associated with European beech or other broad-leaved trees in Europe, especially species of the O. quercusO. piceae complex. The species is responsible for a dark brown staining of the sapwood and its role in the decline of beech in Southern Belgium is also discussed.  相似文献
4.
In the Monte desert of Argentina open woodlands of several species of Prosopis occur in areas with accessible underground water. The great latitudinal extent of the Monte (26–43°S) exhibits strong climatic gradients involving temperature, rainfall seasonality, and wind regime. Prosopis woodlands have been a source of subsistence for human communities for several centuries and continue to be exploited by the local inhabitants. The “mining” of this resource has led to severe desertification and consequent impoverishment of the local people. In order to suggest strategies for the better management and recuperation of these woodlands we studied the population structure and productivity of Prosopis flexuosa from multiple plots at Pipanaco (27°58′S), Telteca (32°20′S), and Ñacuñán (34°03′S). For each plot we measured the density of P. flexuosa trees, number of stems, basal diameter (DAB), height and canopy diameter of each tree. Tree ring data were used to determine the growth rates, annual wood production and biological rotation age for each area. The ecological structure of the woodlands differs between the three sites. Along this north–south transect, there is a decrease in adult tree density, mean basal diameter, mean tree height, canopy cover, productivity and total wood biomass. Consequently, the potential sustainable use of these woodlands varies. Only the northern, Pipanaco, woodlands have the potential for lumber production. In contrast, the short, multi-stem and low-productivity trees in the Telteca and Ñacuñán areas can only sustain a combination of local firewood production and activities such as extensive grazing by livestock. The present, uniform regulations for harvesting wood in these areas must be changed to acknowledge these differences in order to optimize wood production in, and conservation of, these woodlands.  相似文献
5.
6.
7.
8.
Decock C  Huret S  Charue P 《Mycologia》2006,98(3):488-498
Morphological and molecular studies of Gliocephalotrichum collections from rain forest leaf litter in French Guyana revealed the occurrence of two undescribed species, described here as G. bacillisporum and G. longibrachium. Both species have a whorl of sterile stipe extensions directly subtending the conidiogenous penicilli. Gliocephalotrichum bulbilium also was isolated from leaf litter in French Guyana. Two sequences in GenBank, of uncultured ascomycetes from Gabon, Africa, cluster in the Gliocephalotrichum clade, suggesting the probable existence of additional undescribed taxa from the Central African rainforest.  相似文献
9.
This study provides an analysis of the vegetative incompatibility system in Serpula lacrymans (Basidiomycota), a genetic system used to recognize nonself in fungi. Seventy-five worldwide isolates could be grouped into eight vegetative compatibility (VC) types, some of them distributed on different continents. Mating studies combined with vegetative incompatibility analyses revealed that the vegetative incompatibility response between isolates mainly could be explained by two biallelic vegetative incompatibility (vic) loci. The frequency distributions of the interpreted vic alleles do not seem to support the idea of frequency-dependent or balancing selection acting on the vic loci. We find little genetic variation at the vic loci and in one of the loci there was a significant heterozyote deficiency among strains in the overall material. The results may be explained by a recent worldwide dispersal of a few S. lacrymans isolates and, correspondingly, only a few vic alleles are being maintained in these populations.  相似文献
10.
ATP7B is a copper transporting P-type ATPase, also known as Wilson disease protein, which plays a key role in copper distribution inside cells. Recent experimental data in cell culture have shown that ATP7B putatively serves a dual function in hepatocytes: when localized to the Golgi apparatus, it has a biosynthetic role, delivering copper atoms to apoceruloplasmin; when the hepatocytes are under copper stress, ATP7B translocates to the biliary pole to transport excess copper out of the cell and into the bile canaliculus for subsequent excretion from the body via the bile. The above data on ATP7B localization have been mainly obtained in tumor cell systems in vitro. The aim of the present work was to assess the presence and localization of the Wilson disease protein in the human liver. We tested immunoreactivity for ATP7B in 10 human liver biopsies, in which no significant pathological lesion was found using a polyclonal antiserum specific for ATP7B. In the normal liver, immunoreactivity for ATP7B was observed in hepatocytes and in biliary cells. In the hepatocytes, immunoreactivity for ATP7B was observed close to the plasma membrane, both at the sinusoidal and at the biliary pole. In the biliary cells, ATP7B was localized close to the cell membrane, mainly concentrated at the basal pole of the cells. The data suggest that, in human liver, ATP7B is localized to the plasma membrane of both hepatocytes and biliary epithelial cells.  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