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   1122篇
  免费   9篇
  国内免费   1篇
  2013年   169篇
  1984年   7篇
  1964年   8篇
  1963年   7篇
  1962年   6篇
  1960年   10篇
  1959年   9篇
  1953年   7篇
  1952年   7篇
  1951年   7篇
  1950年   11篇
  1949年   5篇
  1948年   6篇
  1947年   12篇
  1946年   8篇
  1945年   5篇
  1944年   7篇
  1943年   30篇
  1942年   19篇
  1941年   10篇
  1940年   28篇
  1939年   42篇
  1938年   30篇
  1937年   27篇
  1936年   34篇
  1935年   27篇
  1934年   36篇
  1933年   28篇
  1932年   21篇
  1931年   25篇
  1930年   35篇
  1929年   25篇
  1928年   36篇
  1927年   28篇
  1926年   21篇
  1925年   24篇
  1924年   20篇
  1923年   10篇
  1922年   10篇
  1921年   11篇
  1920年   14篇
  1919年   15篇
  1917年   15篇
  1916年   7篇
  1915年   13篇
  1913年   10篇
  1911年   7篇
  1909年   7篇
  1907年   7篇
  1904年   5篇
排序方式: 共有1132条查询结果,搜索用时 15 毫秒
31.
Three types of degenerating peptidergic neurosecretory fibres have been found in the posterior pituitary of chronically dehydrated albino rats. "Dark" neurosecretory fibres and their swellings contain neurosecretory granules, neurotubules, shrunken mitochondria and diffusely distributed fine dense material. Some swellings are filled with synaptic vesicles and/or conglomerations of dense membranes. The transitional forms exist between these fibres and extracellular accumulations of electron dense material. Synaptic vesicles, single neurosecretory granules, lipid-like droplets and lamellar bodies occur in the latter. Some neurosecretory fibres and swellings have numerous polymorphous inclusions arising due to degradation of secretory inclusions and organelles, mitochondria and neurotubules in particular. "Dark" neurosecretory elements and those with numerous polymorphous inclusions are enveloped by pituicyte cytoplasm. Sometimes the plasma membranes both of the pituicytes and neurosecretory fibres are destroyed or transformed into a multi-membrane complex. It is assumed that pituicytes may phagocytize degenerating neurosecretory elements. N urosecretory fibres with a locally dissolved neuroplasm and/or large lucent vacuoles seem to be due to axonal degeneration by the "light" type. These neurosecretory elements, the largest of them in particular, may transform into large cavities bordered by a membrane and containing flake-like material and single-membrane vacuoles. Degeneration of neurosecretory elements seems to occur mainly due to hyperfunction of the hypothalamo-hypophysial neurosecretory system.  相似文献   
32.
Spindle- or needle-shaped crystalloids are observed in Sertoli cells of the intersex and experimental cryptorchid swine in the light and electron microscopes. Small crystalloids are also observed in Sertoli cells of the normal swine only by electron microscopy. These crystalloids consist of fine filaments. The filaments are about 5 nm in diameter and arranged parallel to the long axis of the drystalloid. In cross sections of the crystalloid, the close backing of the filaments shows hexagonal arrays. The interfilamentous distance is about 5 nm. In all animals, bundles of short filaments, which are 5nm in diameter, are observed in the basal part of the Sertoli cells. Ultrastructural similarities among the crystalloids, the bundles of fine filaments, and the filamentous layer in the junctional specialization of the Sertoli cell are shown. These morphological similarities suggest that the crystalloids are formed by the aggregation of the bundles in the Sertoli cells of azoospermic testes.  相似文献   
33.
34.
35.
36.
37.
38.
MANGEL SCAB—ITS CAUSE AND HISTOGENY   总被引:2,自引:0,他引:2  
  相似文献   
39.
We stressed in our wourk the necessity of knowing the details of the interaction between the acid mucopolysaccharides and the collagen. Employing the appropriate methods we carried out the measurements of birefringence of strictly limited parts of collagen bundles. The measurements were carried out before and after the collagen bundles were subjected to the action of testicular hyaluronidase.The statistic study of the data we arrived have revealed that the testicular hyaluronidase which removes the acid mucopolysaccharides causes a decrease of form birefringence.These results are discussed on the regard to former research with done by the author and the conclusions may be drawn that the acid mucopolysaccharides play a part in the form birefringence of collagen bundles, and therefore have a macromolecular orientation.The author is indebted to Prof. Lucien Lison who has done the statistical processing.  相似文献   
40.
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