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   3210640篇
  免费   257464篇
  国内免费   9325篇
耳鼻咽喉   45264篇
儿科学   100892篇
妇产科学   86452篇
基础医学   446486篇
口腔科学   91972篇
临床医学   293524篇
内科学   634774篇
皮肤病学   69691篇
神经病学   269645篇
特种医学   129006篇
外国民族医学   1111篇
外科学   489566篇
综合类   76922篇
现状与发展   3篇
一般理论   1298篇
预防医学   262335篇
眼科学   73642篇
药学   233671篇
  9篇
中国医学   5772篇
肿瘤学   165394篇
  2018年   32857篇
  2016年   29203篇
  2015年   32881篇
  2014年   46833篇
  2013年   71067篇
  2012年   92207篇
  2011年   98220篇
  2010年   59256篇
  2009年   57114篇
  2008年   92744篇
  2007年   98781篇
  2006年   99885篇
  2005年   97304篇
  2004年   93400篇
  2003年   90485篇
  2002年   88115篇
  2001年   147403篇
  2000年   152376篇
  1999年   128305篇
  1998年   38626篇
  1997年   34854篇
  1996年   35160篇
  1995年   34630篇
  1994年   32467篇
  1993年   30395篇
  1992年   104897篇
  1991年   101669篇
  1990年   98094篇
  1989年   93970篇
  1988年   87454篇
  1987年   86248篇
  1986年   81629篇
  1985年   78444篇
  1984年   59783篇
  1983年   50950篇
  1982年   31504篇
  1981年   28339篇
  1980年   26667篇
  1979年   55691篇
  1978年   39830篇
  1977年   33547篇
  1976年   31342篇
  1975年   32907篇
  1974年   40100篇
  1973年   38194篇
  1972年   35722篇
  1971年   33101篇
  1970年   30926篇
  1969年   28796篇
  1968年   26494篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
41.
42.
43.
44.
45.
46.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease.  相似文献   
47.
48.
49.
We aimed to evaluate the potential of the cerebrospinal fluid (CSF) axonal damage biomarker NfH(SMI35) in the laboratory-supported differential diagnosis of parkinsonian syndromes. Patients with idiopathic Parkinson's disease (PD; n = 22), multiple-system atrophy (MSA; n = 21), progressive supranuclear palsy (PSP; n = 21), corticobasal degeneration (CBD; n = 6), and age-matched controls (n = 45) were included. CSF levels of NfH(SMI35) were measured using ELISA. Levels of CSF NfH(SMI35) were elevated in PSP compared to PD and controls (P < 0.05 each). They were also significantly higher in MSA than in PD and controls (P < 0.05 each). NfH(SMI35) differentiated PD from PSP with a sensitivity of 76.5% and a specificity of 94.4%. Axonal damage as measured by CSF NfH(SMI35) is most prominent in the more rapidly progressive syndromes PSP and MSA as compared to PD or CBD. CSF NfH(SMI35) may therefore be of some value for the laboratory-supported differential diagnosis of atypical parkinsonian syndromes.  相似文献   
50.
Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.  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