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   26篇
  免费   0篇
现状及发展   2篇
研究方法   1篇
综合类   21篇
自然研究   2篇
  2019年   1篇
  2016年   1篇
  2011年   1篇
  2010年   1篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   2篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
  1991年   1篇
  1987年   1篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1970年   1篇
排序方式: 共有26条查询结果,搜索用时 15 毫秒
1.
A reappraisal of human beta MSH   总被引:10,自引:0,他引:10  
  相似文献   
2.
3.
4.
The peculiar object P/2010?A2 was discovered in January 2010 and given a cometary designation because of the presence of a trail of material, although there was no central condensation or coma. The appearance of this object, in an asteroidal orbit (small eccentricity and inclination) in the inner main asteroid belt attracted attention as a potential new member of the recently recognized class of main-belt comets. If confirmed, this new object would expand the range in heliocentric distance over which main-belt comets are found. Here we report observations of P/2010?A2 by the Rosetta spacecraft. We conclude that the trail arose from a single event, rather than a period of cometary activity, in agreement with independent results. The trail is made up of relatively large particles of millimetre to centimetre size that remain close to the parent asteroid. The shape of the trail can be explained by an initial impact ejecting large clumps of debris that disintegrated and dispersed almost immediately. We determine that this was an asteroid collision that occurred around 10 February 2009.  相似文献   
5.
本通过对几种拆分手性药物的方法的列举,比较几种方法,详细介绍了几种方法的特点,以及它们的不同作用。各个方法中又列出了不同的线索,根据这些线索来研究这几种拆分的方法,它们的优缺点以及针对这些缺点的解决方法,最后给出了几个典型的用该方法的实验,以辨别它们的效用。  相似文献   
6.
Summary The failure of Australian goats fedLeucaena leucocephala (leucaena) to degrade 3-hydroxy-4(1H) pyridone (DHP), the goitrogenic metabolite of mimosine, was overcome when they were infused with rumen fluid from an Indonesían goat. The leucaena toxicity problem in Australia may well be solved by transfer of specific bacteria capable of degrading DHP anaerobically.We acknowkledge the assistance of R.G. Megarrity in preparation of the goats in Australia and R. Dixon and staff at the CSIRO Lansdown Research Station for preparation of the feed. In Balai Penelitian Ternak; G. Riding, and Suwandi for the metabolism study facilities, Riad the feeding, Miss Leanne Rochanda sample preparation and Mrs M. Young for veterinary assistance. Analyses were carried out by R. Lowe, Jernih Rosida and Wildan.  相似文献   
7.
8.
K J Tracey  Y Fong  D G Hesse  K R Manogue  A T Lee  G C Kuo  S F Lowry  A Cerami 《Nature》1987,330(6149):662-664
Bacterial infection of the mammalian bloodstream can lead to overwhelming sepsis, a potentially fatal syndrome of irreversible cardiovascular collapse (shock) and critical organ failure. Cachectin, also known as tumour necrosis factor, is a macrophage-derived peptide hormone released in response to bacterial lipopolysaccharide, and it has been implicated as a principal mediator of endotoxic shock, although its function in bacterial sepsis is not known. Anaesthetized baboons were passively immunized against endogenous cachectin and subsequently infused with an LD100 dose of live Escherichia coli. Control animals (not immunized against cachectin) developed hypotension followed by lethal renal and pulmonary failure. Neutralizing monoclonal anti-cachectin antibody fragments (F(ab')2) administered to baboons only one hour before bacterial challenge protected against shock, but did not prevent critical organ failure. Complete protection against shock, vital organ dysfunction, persistent stress hormone release and death was conferred by administration of antibodies 2 h before bacterial infusion. These results indicate that cachectin is a mediator of fatal bacteraemic shock, and suggest that antibodies against cachectin offer a potential therapy of life-threatening infection.  相似文献   
9.
The present study reviews the taxonomy of the Phtisicidae (Crustacea: Amphipoda) from the coast of New South Wales, Australia. The following seven species are described; Dodecas decacentrum Stebbing, 1910b, Dodecas hexacentrum Mayer, 1903, Hircella cornigera (Haswell, 1879b), Metaproto novaehollandiae (Haswell, 1879a), Notoprotomima smithi gen. nov., sp. nov., Paraproto sp. and Perotripus sp. Generic diagnoses of Notoprotomima gen. nov., Dodecas, Hircella and Metaproto are provided based on the present materials. Notoprotomima smithi is fully described as a new species of the new genus. Dodecas decacentrum differs from Dodecas hexacentrum by the presence of paired dorsodistal projections on pereonite 2, paired mid-dorsal projections on pereonites 3 and 4 and shorter gill length on pereonites 2 and 3. Hircella cornigera and Metaproto novaehollandiae are described in detail. The larger mature males of M. novaehollandiae possess the unusual massive type of the propodus of gnathopod 2. The extended distribution of Perotripus to the New South Wales coast is noted. A key for these phtisicid amphipods from New South Wales, Australia is provided.  相似文献   
10.
E Potter  D P Behan  W H Fischer  E A Linton  P J Lowry  W W Vale 《Nature》1991,349(6308):423-426
Corticotropin-releasing factor (CRF), is a potent stimulator of synthesis and secretion of preopiomelanocortin-derived peptides. Although CRF concentrations in the human peripheral circulation are normally low, they increase throughout pregnancy and fall rapidly after parturition. Maternal plasma CRF probably originates from the placenta, which responds to the bioactive peptide and produces the peptide and its messenger RNA. Even though CRF concentrations in late gestational maternal plasma are similar to those in rat hypothalamic portal blood and to those that can stimulate release of adrenocorticotropic hormone (ACTH) in vitro, maternal plasma ACTH concentrations increase only slightly with advancing gestation and remain within the normal range. Several groups have now reported the existence of a CRF-binding protein in human plasma which inactivates CRF and which has been proposed to prevent inappropriate pituitary-adrenal stimulation in pregnancy. The binding protein was recently purified from human plasma. We have now isolated and partially sequenced the binding protein, allowing us to clone and characterize its complementary DNA from human liver and rat brain. Expression of the cDNAs for human and rat binding protein in COS7 cells showed that these proteins bind CRF with the same affinity as the native human protein. Both rat and human recombinant binding proteins inhibit CRF binding to a CRF antibody and inhibit CRF-induced ACTH release by pituitary cells in vitro.  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