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   38406篇
  免费   1822篇
  国内免费   201篇
耳鼻咽喉   504篇
儿科学   718篇
妇产科学   587篇
基础医学   4910篇
口腔科学   1337篇
临床医学   2951篇
内科学   9166篇
皮肤病学   947篇
神经病学   2766篇
特种医学   1532篇
外科学   6263篇
综合类   248篇
一般理论   2篇
预防医学   1188篇
眼科学   735篇
药学   2726篇
中国医学   53篇
肿瘤学   3796篇
  2022年   448篇
  2021年   771篇
  2020年   385篇
  2019年   555篇
  2018年   772篇
  2017年   558篇
  2016年   628篇
  2015年   721篇
  2014年   946篇
  2013年   1071篇
  2012年   1728篇
  2011年   1854篇
  2010年   1053篇
  2009年   930篇
  2008年   1664篇
  2007年   1720篇
  2006年   1767篇
  2005年   1772篇
  2004年   1706篇
  2003年   1623篇
  2002年   1636篇
  2001年   1267篇
  2000年   1431篇
  1999年   1266篇
  1998年   455篇
  1997年   335篇
  1996年   353篇
  1995年   317篇
  1994年   269篇
  1993年   254篇
  1992年   820篇
  1991年   773篇
  1990年   693篇
  1989年   719篇
  1988年   695篇
  1987年   679篇
  1986年   681篇
  1985年   618篇
  1984年   449篇
  1983年   358篇
  1979年   346篇
  1978年   234篇
  1977年   202篇
  1975年   204篇
  1974年   230篇
  1973年   209篇
  1972年   198篇
  1971年   209篇
  1970年   205篇
  1969年   226篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Since the prevalence and clinical characteristics of young-onset hypertension are still to be elucidated, we performed targeted-screening at an annual university health check-up for two consecutive years. Out of 16,464 subjects in 2003 and 17,032 in 2004 that were aged less than 30 years, 22 and 26 students (all males) exhibited high blood pressure (BP), respectively, on three occasions during casual BP measurements at the Tohoku University Health Center (systolic and diastolic BP of 140 and/or 90 mmHg or greater, respectively). These students were asked to measure their BP at home, and 9 subjects in total were diagnosed as having essential hypertension (EH). The remaining students were diagnosed as having white coat hypertension (WCH). In 8 out of 9 EH students, their father and/or mother had also been treated with antihypertensive medication. Adjustment by attendance ratio for each BP measurement suggested that the incidence of EH was around 0.1% and that of hypertension (EH and WCH) was around 0.5% in university students aged less than 25 years, since most of the subjects and hypertensive students were between 18 and 24 years old. Body mass index of the EH, which was more than 25 kg/m2 (overweight), was significantly higher than that with WCH. In conclusion, the combination of repeated casual BP measurements and home BP effectively identified young-onset EH. The clinical parameters indicated that male gender, genetic background, and excessive weight were risk factors for young-onset hypertension.  相似文献   
52.
We describe a 54-year-old woman with primary pulmonary adenocarcinoma showing a characteristic papillary architecture and prominent cilia formation. Immunohistochemically, the tumor cells were positive for carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA) and Leu Ml, and negative for lactoferrin and surfactant apoprotein. An ultrastructural study also indicated differentiation toward bronchial surface epithelial cells. To our knowledge, this type of neoplasm has not been reported as peripheral-type adenocarcinoma of the lung. Acta Pathol Jpn 42: 745–750, 1992.  相似文献   
53.
54.
55.
Background Evidence suggests that, as a group, patients with schizophrenia have intellectual deficits that may precede the manifestation of psychotic symptoms; however, how successfully intelligence tests are able to discriminate schizophrenia from other psychotic disorders has yet to be investigated in detail. Methods Using Wechsler Adult Intelligence Scale – Revised (WAIS‐R) data for 55 inpatients with schizophrenia and 28 inpatients with non‐schizophrenic psychotic disorders (NSPD) (schizophreniform disorder, brief psychotic disorder, delusional disorder, psychotic disorder due to a general medical condition, and psychotic disorders not otherwise specified), intelligence performance was compared between schizophrenia and NSPD and among different subtypes of schizophrenia. Results There were no significant differences in intelligence quotient (IQ), verbal IQ (VIQ) and performance IQ (PIQ) discrepancy, and subtest scores of WAIS‐R between the patients with schizophrenia and those with NSPD. These diagnostic groups were not discriminated well by any WAIS‐R variables. Schizophrenia patients with prominent negative symptoms, on the other hand, had a significantly larger IQ discrepancy (VIQ > PIQ) than those without prominent negative symptoms and NSPD patients. Intelligence performance in schizophrenia did not differ with respect to diagnostic subtypes and longitudinal courses. Conclusions The current study failed to show diagnostic usefulness of WAIS‐R in discriminating schizophrenia and other psychoses. A diagnosis of schizophrenia does not significantly impact intellectual deficits in psychotic disorders.  相似文献   
56.
57.
Radiographic studies of three cases of hypoplasia of the humeral trochlea were done. Several other anomalies were also detected, including a hypoplastic capitellum in case 2, a hyperplastic radial head in cases 2 and 3, and bulging of the loose joint capsule in case 3. Operations in cases 1 and 3, disclosed that ganglions and fibrous septa compressed the ulnar nerve. The cause of ulnar nerve palsy in patients with hypoplasia of the humeral trochlea is thought to be associated with the high incidence of ganglions in hypoplastic elbow joints. The ganglion may play a role.  相似文献   
58.
59.
60.
Abstract: The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and stroma-free hemoglobin (SFH) on vascular responsiveness to various vasoactive substances were examined in isolated perfused rat kidneys. The kidneys isolated from rats were perfused with 6% PHP, 6% SFH, and 6% hydroxyethylstarch (HES) solution at a constant flow rate. Vascular responsiveness to acetylcholine (ACh), nitroglycerin (NG), norepinephrine (NE), and angiotensin-II (ANG-II) was examined by measuring the perfusion pressure (PP). Effects of inhibition of endothelium-derived relaxing factor (EDRF) by NG-monomethyl L-arginine (L-NMMA) on NE-induced and ANG-II-induced renal vascular responses were examined. ACh and NG induced a dose-dependent decrease in perfusion pressure (PP) in all groups. NE and ANG-II induced an increase in PP in all groups, but NE-induced and ANG-II-induced responses in the PHP-perfused and SFH-perfused groups were significantly larger than those in the HES-perfused group. L-NMMA did not alter vascular responsiveness to NE and ANG-II. These results indicate that PHP and SFH do not inhibit EDRF induced by ACh, but hemoglobin moiety per se does augment the vascular responsiveness to NE and ANG-II in the isolated perfused rat kidney.  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