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   323篇
  免费   12篇
  国内免费   3篇
耳鼻咽喉   1篇
儿科学   18篇
妇产科学   2篇
基础医学   50篇
口腔科学   6篇
临床医学   28篇
内科学   56篇
皮肤病学   8篇
神经病学   41篇
特种医学   34篇
外科学   26篇
综合类   7篇
一般理论   1篇
预防医学   27篇
药学   15篇
中国医学   1篇
肿瘤学   17篇
  2023年   2篇
  2019年   3篇
  2018年   6篇
  2017年   2篇
  2016年   3篇
  2015年   4篇
  2014年   9篇
  2013年   12篇
  2012年   12篇
  2011年   12篇
  2010年   5篇
  2009年   11篇
  2008年   10篇
  2007年   10篇
  2006年   6篇
  2005年   10篇
  2004年   9篇
  2003年   10篇
  2002年   11篇
  2001年   7篇
  2000年   7篇
  1999年   7篇
  1998年   10篇
  1997年   14篇
  1996年   6篇
  1995年   15篇
  1994年   6篇
  1993年   7篇
  1992年   7篇
  1991年   4篇
  1990年   5篇
  1989年   7篇
  1988年   12篇
  1987年   7篇
  1986年   11篇
  1985年   8篇
  1984年   5篇
  1983年   6篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1976年   3篇
  1975年   5篇
  1973年   5篇
  1969年   2篇
  1966年   1篇
  1965年   1篇
排序方式: 共有338条查询结果,搜索用时 46 毫秒
1.
2.
Fulminant subacute sclerosing panencephalitis in association with pregnancy   总被引:1,自引:0,他引:1  
Subacute sclerosing panencephalitis developed during pregnancy in a 27-year-old woman and immediately after delivery in an 18-year-old woman. In both, disease took an acute and fulminant course culminating in a vegetative state within several weeks. It is suggested that the relative older age of disease presentation and the unusually rapid neurologic deterioration were partially due to immunologic and hormonal alterations of pregnancy.  相似文献   
3.
In the hatched chick the fibers of the two optic nerves segregate into clearly defined bundles when they cross to the other side. These bundles run in horizontally oriented tiers. The tiers are demarcated by blood vessels and pial tissue. The organization of these tiers was investigated qualitatively and quantitatively using light and electron microscopy as well as tracer techniques. The fibers within the tiers cross to the contralateral optic tract without leaving their respective tier. The mean total number of tiers is 34 with a great individual variation. A preference in the superposition of one side over the other could not be observed. Comparing these data with our earlier study (Rager et al.: Anat. Embryol., 179:135-148, 1988) it can be concluded that neither the segregation of fibers into discrete bundles nor the variability in the number of alternating tiers seem to disturb the topography of fibers as it is achieved in the optic nerve. The pattern of vascularization correlates with the order of crossing axon bundles and contributes to the demarcation of the tiers. The chiasm is vascularized by the Aa. preopticae and the A. infundibularis.  相似文献   
4.
Adrenaline infusion of 0.1 g · kg–1 · min–1 in healthy volunteers results in an increase of hepatic glucose production, an increase of the absolute number of occupied -adrenoceptors and specific changes in metabolism. To compare these effects with the changes induced by an endogenous catecholamine release, we investigated healthy volunteers during cycle ergometry. After fasting at least 14 h seven healthy subjects exercised for 90 min at an intensity of 20% below their individual anaerobic threshold. The rate of glucose production as well as the turnover rates of alanine and leucine were calculated using stable isotope tracers. High and low affinity -adrenergic binding sites on lymphocytes were determined by an equilibrium binding assay with (–)125 Iodocyanopindolol. After 90 min of cycling the rate of appearance of glucose increased significantly from means of 2.0 (SD 0.2) to 2.65 (SD 0.50) mg · kg–1 · min–1 with unchanged blood concentrations of glucose and lactate. The flux of the amino acids alanine and leucine decreased significantly from means of 0.91 (SD 0.21) to 0.62 (SD 0.14) mg · kg–1 · min–1 and from 0.40 (SD 0.05) to 0.32(SD 0.04) mg · kg–1 · min–1, respectively. The mean free fatty acid concentration increased significantly from 0.65 (SD 0.33) to 1.27 (SD 0.45) mmol · l–1 during the endurance trial. The increase of glucose turnover and the decrease of amino acid flux point to a metabolic shift towards enhanced utilization of free fatty acids. Adrenaline and noradrenaline concentrations showed a moderate but significant increase from means of 0.61 (SD 0.20) to 0.99 (SD 0.36) nmol · l–1 and from 2.27 (SD 0.75) to 3.46 (SD 0.38) nmol · 1–1, respectively. The number of high affinity -adrenergic binding sites per cell (-adrenoceptors) nearly doubled from 770 (SD 130) to 1490 (SD 150) during 90 min of cycling. The observed endogenous plasma catecholamine concentrations were not sufficient to change significantly the relative receptor occupancy. This would seem to indicate that the aerobic exercise induced effects depended more on the absolute number of occupied -adrenoceptors than on their relative receptor occupancy. When compared to the results of the adrenaline infusion experiment the increases of the hepatic glucose production and the increase of -adrenoceptors were very similar in both groups despite ten times higher adrenaline plasma concentrations in the infusion group. This would seem to indicate that -adrenoceptors mediated effects do not correlate with catecholamine plasma concentrations.  相似文献   
5.
Malignancy may adversely influence the quality and behaviour of oocytes   总被引:1,自引:1,他引:1  
A case series of eight cycles of in-vitro fertilization (IVF) in five women diagnosed with malignant disorders is presented. These patients chose to defer definitive treatment for a chance for preservation of potential fertility. The response of these patients to ovarian stimulation, and the outcome, was compared with 17 IVF cycles in 12 age- matched patients with isolated tubal infertility. An apparent adverse influence of malignant disease on the quality and behaviour of oocytes was observed. Despite a comparable total number of oocytes per cycle in the two groups, a significantly reduced percentage of mature oocytes was retrieved per cycle from patients with malignant diseases. The oocytes from patients with malignant disorders were of a poorer quality and exhibited a significantly impaired fertilization rate compared to the controls. We propose that neoplastic processes, irrespective of the site or cell of origin, may have a detrimental impact on the biology of oocytes, an effect akin to that seen on spermatozoa in men with certain malignancies.   相似文献   
6.

Background  

The role of both microglial activation and alpha-synuclein deposition in Parkinson's disease remain unclear. We have tested the hypothesis that if microglia play a primary role in Parkinson's disease pathogenesis, the microglial "activated" phenotype should be associated with histopathological and/or clinical features of the disease.  相似文献   
7.
Summary WGA-HRP injections were placed into area 17 close to the border with area 18 of Tupaia belangeri in order to study the callosal connections of the striate area in this animal. Most callosal neurons were found in the striate cortex (57.6–86.9%), some in the extrastriate area 18 (10.6–28.1%), and a few in even more temporal regions (2.5–14.3%). Concerning only the area 17, reciprocal homotopic connections could be observed as a strip along the area 17/18 border. Additionally, heterotopic callosal connections could be seen in regions representing the binocular visual field, especially the lower part. The area 17 cells were mostly located in the supragranular layers II and III (94.1–97.2%). But neurons could also be found in the infragranular layers, especially layer VI (2.6–5.2%) and in layer IV (0.2–1.1%). Homotopic projections were mostly seen in layers IIIc and V. The majority of the supragranular and infragranular neurons are pyramidal cells. However, a newly defined subpopulation of neurons, most probably stellate cells, were discovered forming a band in sublayer IIIc, very close to the layer III/IV border.  相似文献   
8.
We used the rapid Golgi and horseradish peroxidase (HRP) techniques to study the dendritic spread of relay neurons in functionally distinct laminae of the tree shrew dorsal lateral geniculate nucleus (LGNd). On the basis of their dendritic spread in relation to laminar and interlaminar zones, we describe three classes of relay neurons. Unilaminar neurons with multipolar radiate, bitufted, and intermediate types of dendrites. Dendrites of these neurons are confined to one lamina only, but also can have some of their segments in adjacent interlaminar zones. Multilaminar neurons with multipolar radiate, bitufted, and intermediate types of dendrites. Independent of the site of their cell bodies in a laminar or interlaminar zone, these neurons spread their dendrites over two or more laminae. Interlaminar neurons whose cell bodies and dendrites are confined to a single interlaminar zone. Unilaminar neurons are found in all the laminae. In the medial three laminae, they are more of the radiate type, whereas in laminae 4 and 5 their dendrites tend to be more of a tufted nature. Lamina 6 shows a preponderance of the elongated bitufted type. Multilaminar neurons, although less common as compared to the unilaminar, are also observed in all the laminae. Some neurons have their dendrites confined to an interlaminar zone. By retrograde transport of HRP injected into the visual cortex, we have shown that these neurons are, in fact, relay neurons. In addition to relay neurons, there are small interneurons with "axoniform" dendrites and an unmyelinated axon whose arborization is confined within the limits of the neuron's dendritic spread. Neurons of this type are not labeled with HRP injected into the visual cortex. We conclude that although each lamina is functionally specialized by input from ipsilateral or contralateral retina and by segregation of neurons responding to on or off stimuli, some multilaminar neurons can be found in each lamina. Thus, laminar as well as interlaminar zones contain a class of neurons that could provide a cross-talk between the functionally specialized laminae. Most relay neurons in all the laminae, however, confine their dendrites to their home lamina. Thus, the dendritic architecture of relay neurons allows for processing of information both within channels and between channels.  相似文献   
9.
Characteristics of 1096 recidivistic mentally ill criminal offenders admitted to a specialized hospital in France are described. All subjects were mentally ill and had been judged nonresponsible for an act of crime. Crimes against persons (murder or assault) accounted for 42% of the crimes for which these patients were admitted. The remaining causes of admission were crimes against property (theft) and "victimless" crimes. Subject files indicated a wide difference in cause of admission for violent acts among the different diagnostic categories. Although the frequency of readmission and violent acts at readmission did not change for the group as a whole, they did change between admissions for the different diagnostic groups. Results indicate that differences exist between diagnostic categories of mentally ill offenders in terms of not only the type of crime committed but also the likelihood of recidivism.  相似文献   
10.
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