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   1664篇
  免费   136篇
  国内免费   5篇
耳鼻咽喉   25篇
儿科学   21篇
妇产科学   15篇
基础医学   238篇
口腔科学   24篇
临床医学   156篇
内科学   370篇
皮肤病学   29篇
神经病学   345篇
特种医学   91篇
外科学   140篇
综合类   19篇
一般理论   2篇
预防医学   163篇
眼科学   23篇
药学   100篇
中国医学   1篇
肿瘤学   43篇
  2021年   24篇
  2020年   14篇
  2019年   23篇
  2018年   26篇
  2017年   30篇
  2016年   34篇
  2015年   33篇
  2014年   32篇
  2013年   56篇
  2012年   85篇
  2011年   98篇
  2010年   35篇
  2009年   34篇
  2008年   66篇
  2007年   64篇
  2006年   69篇
  2005年   71篇
  2004年   65篇
  2003年   61篇
  2002年   76篇
  2001年   50篇
  2000年   70篇
  1999年   58篇
  1998年   19篇
  1997年   23篇
  1996年   23篇
  1995年   17篇
  1994年   23篇
  1993年   30篇
  1992年   38篇
  1991年   31篇
  1990年   29篇
  1989年   36篇
  1988年   19篇
  1987年   25篇
  1986年   34篇
  1985年   32篇
  1984年   20篇
  1983年   18篇
  1979年   17篇
  1978年   15篇
  1976年   9篇
  1975年   10篇
  1973年   9篇
  1972年   11篇
  1971年   12篇
  1970年   14篇
  1969年   13篇
  1968年   13篇
  1966年   10篇
排序方式: 共有1805条查询结果,搜索用时 192 毫秒
1.
The following recommendations of the Neonatal Hemostasis Subcommittee of the Scientific and Standardization Committee of the ISTH for the management of neonatal immune thrombocytopenia were prepared by the working party on neonatal immune thrombocytopenia. Evaluation, diagnosis, and treatment of the mother and neonate with alloimmune and autoimmune thrombocytopenia are discussed and current recommendations provided. This document is likely to require frequent future revision(s).  相似文献   
2.
It has been previously demonstrated that the generation of measles virus (MV)-specific cytotoxicity (CTL) is reduced in patients with multiple sclerosis (MS). By contrast, CTL specific for influenza virus (FLU) and mumps virus is normal. It is uncertain if reduced CTL is limited to MV in MS patients, or if reduced CTL may be found to other viruses as well. Since MV-specific CTL is predominantly restricted by HLA class II molecules, while FLU-specific and mumps-specific CTL have large HLA class I-restricted components, reduced MV-specific CTL may reflect a broader reduction in HLA class II-restricted CTL in patients with MS. To examine this question we studied the generation of CTL specific for herpes simplex virus type I (HSV). HSV-specific CTL, like MV-specific CTL is predominantly restricted by HLA class II molecules. We found that patients with MS had reduced generation of CTL to both MV and HSV. Most, but not all patients who had reduced generation of CTL to one virus also had a similar impairment with respect to the second virus. Some patients, however, had a reduction in the generation of CTL only to MV or to HSV. These findings extend our earlier observations regarding reduced MV-specific CTL in patients with MS to a second HLA class II-restricted virus, HSV. Such a reduction may reflect discrete impairments in immune function to separate viruses, possibly those that are associated with viral persistence, or may reflect a more generalized defect in HLA class II-restricted CTL.  相似文献   
3.
4.
5.
Reflex responses recorded from the upper and lower divisions of the human orbicularis oris muscle were studied as a function of the site of stimulation. Stimuli were applied to 11 sites, ranging from the glabrous skin of the upper and lower lip vermilion borders to the hairy skin of the cheek. Highly localized, innocuous mechanical stimuli were created by displacing a servo-controlled probe over the surface of the perioral skin. Reflex response amplitude was strongly dependent on the site of stimulation. Stimulation of some sites, for example the ipsilateral corner of the mouth, the chin, and cheek, produced no responses, whereas stimulation of other sites, particularly the ipsilateral vermilion borders, produced large reflex responses. Changes in response amplitude as a function of stimulation site were the same for the upper lip and lower lip muscle recordings, with the largest responses at both recording sites produced by stimulation of the ipsilateral upper lip vermilion border. These results suggest that the upper and lower divisions of orbicularis oris share common synaptic drive, at least from inputs generated via reflex pathways, and that the upper vermilion border may be more densely innervated with mechanoreceptors than the lower. The latter hypothesis was supported by an additional experiment examining two-point discrimination thresholds for the glabrous skin of the upper and lower lips. Two-point thresholds were significantly smaller for the upper compared with the lower lip vermilion border.  相似文献   
6.
7.
8.
9.
We report a case of neonatal alloimmune thrombocytopenia and intracranial hemorrhage in an infant whose mother received immunizations of paternal mononuclear cells. This therapy is designed to prevent unexplained first trimester miscarriages. No previous cases of platelet autoimmunization associated with maternal immunization with paternal mononuclear cells has been reported. Treatment with antenatal maternal infusions of intravenous gamma globulin (IVGG) did not prevent fetal thrombocytopenia, but IVGG may become the treatment of choice for postnatal, antibody-mediated thrombocytopenia of the newborn.  相似文献   
10.
A continuous air monitor has been developed that includes provisions for improving the detection of alpha-emitting aerosol particles in the presence of radon/thoron progeny that are unattached to ambient aerosol particles. Wind tunnel tests show that 80% of 10-microns aerodynamic equivalent diameter particles penetrate the flow system from the ambient air to the collection filter when the flow rate is 57 L min-1 (2 cfm) and the wind speed is 1 m s-1. Uniformity of aerosol collection on the filter, as characterized by the coefficient of variation of the areal density deposits, is less than 15% for 10-microns aerodynamic-equivalent-diameter aerosol particles. Tests with unattached radon daughters in a flow-through chamber showed that approximately 99% of the 218Po was removed by an inlet screen that is designed to collect radon daughters that are in the size range of molecular clusters. The inlet screen offers the opportunity to improve the signal-to-noise ratio of energy spectra in the regions of interest (subranges of the energy spectrum) of transuranic elements and thereby enhance the performance of background compensation algorithms.  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