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   11910篇
  免费   1316篇
  国内免费   67篇
耳鼻咽喉   63篇
儿科学   338篇
妇产科学   377篇
基础医学   1620篇
口腔科学   212篇
临床医学   1376篇
内科学   2770篇
皮肤病学   205篇
神经病学   1312篇
特种医学   700篇
外科学   1241篇
综合类   221篇
一般理论   11篇
预防医学   1180篇
眼科学   162篇
药学   712篇
中国医学   2篇
肿瘤学   791篇
  2021年   126篇
  2020年   120篇
  2019年   149篇
  2018年   184篇
  2017年   153篇
  2016年   169篇
  2015年   210篇
  2014年   280篇
  2013年   403篇
  2012年   541篇
  2011年   518篇
  2010年   328篇
  2009年   330篇
  2008年   563篇
  2007年   557篇
  2006年   487篇
  2005年   497篇
  2004年   407篇
  2003年   363篇
  2002年   321篇
  2001年   321篇
  2000年   381篇
  1999年   325篇
  1998年   205篇
  1997年   202篇
  1996年   235篇
  1995年   163篇
  1994年   145篇
  1993年   142篇
  1992年   266篇
  1991年   284篇
  1990年   262篇
  1989年   265篇
  1988年   233篇
  1987年   252篇
  1986年   281篇
  1985年   261篇
  1984年   170篇
  1983年   161篇
  1982年   116篇
  1981年   96篇
  1980年   101篇
  1979年   177篇
  1978年   114篇
  1977年   98篇
  1976年   93篇
  1975年   107篇
  1974年   103篇
  1973年   104篇
  1972年   93篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Sequential salivary gland scintigraphy with 99mTc-technetium pertechnetate (Tc-99) is a safe, minimally invasive test for study of major salivary glands. However, its relationship to salivary function has not been investigated in detail. We have investigated the relationship between major salivary gland flow rates and Tc-99 scans and developed a new rating scale using scans of a control group with normal salivary function. Salivary flow rates and Tc-99 scans were obtained from healthy, non-medicated subjects (n = 33) and from xerostomic patients (n = 22). There were significant differences between the groups for salivary flow rates and Tc-99 ratings. Significant correlations were found between salivary flow rates and Tc-99 ratings in the control and xerostomic groups. The Tc-99 rating scale proved reliable in assessing salivary dysfunction, and showed a high inter-examiner correlation. These results demonstrate the usefulness of salivary gland scintigraphy in assessing major salivary gland flow rates and the utility of a new rating scale.  相似文献   
72.
73.
A wheat embryo cytokinin-binding protein was covalently modified with the radiolabeled photoaffinity ligand 2-azido-N6-[14C]benzyladenine. A single labeled peptide was obtained after proteolytic digestion and isolation by reversed-phase and anion-exchange HPLC. Sequencing by classical Edman degradation identified 11 of the 12 residues but failed to identify the labeled amino acid. Analysis by laser photodissociation Fourier-transform mass spectrometry of 10 pmol of the peptide independently confirmed the Edman data and also demonstrated that the histidine residue nearest the C terminus (underlined) was modified by the reagent in the sequence Ala-Phe-Leu-Gln-Pro-Ser-His-His-Asp-Ala-Asp-Glu.  相似文献   
74.
Background. Paragangliomas of the head and neck are slow-growing tumors that originate from neural crest cells. Between 7% and 9% of these tumors have a familial occurrence. The suspected gene for familial paragangliomas (FP) is transmitted with an autosomal dominant mode of inheritance with incomplete penetrance, and appears to exhibit genomic imprinting. It has been demonstrated by family studies that individuals who inherit the gene(s) from their father will develop the disease. Through linkage analysis, the gene(s) for FP has been postulated to be located on the long arm of chromosome 11. The discovery of many different genes has been elucidated through the cytogenetic analysis of affected individuals who carry specific chromosome aberrations. This project was designed to look for chromosome abnormalities in several second-generation family members to further assist in the localization of the gene(s) for FP. Methods. This study involved the cytogenetic evaluation of lymphocytes, fibroblasts, and tumor cells of several second-generation family members from a three-generation family with FP of the head and neck to look for chromosome abnormalities generally, and for abnormalities of chromosome 11 specifically. Standard cytogenetic techniques were used for lymphocyte and fibroblast cultures. Tumor cells were cultured in a collagen matrix with F12 medium supplemented with 3% L-glutamine and 10% fetal calf serum. Results. There were no detectable abnormalities of chromosome 11 in any of the cells. However, nonrandom abnormalities of chromosomes 5 and 7 were seen in some of the tumor cells of one FP patient. To our knowledge, this is the first article which demonstrated the ability to successfully culture FP of the head and neck. © 1995 Jons Wiley & Sons, Inc.  相似文献   
75.
76.
Male genital oedema can be defined as swelling or the appearance of swelling of the scrotum and/or the penile shaft and prepuce. Despite the various causes of genital oedema reported in the published work, a concise approach to the evaluation and management has not been sufficiently addressed.  相似文献   
77.
78.
Although Acinetobacter is usually a species of low virulence, it is becoming increasingly more important as a cause of hospital outbreaks, particularly on intensive care units. Antibiotic resistance can develop rapidly. This organism has not been reported to cause skin abscesses previously. We describe a case of a neonate who developed an Acinetobacter abscess on our neonatal intensive care unit.  相似文献   
79.
80.
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