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   123496篇
  免费   8048篇
  国内免费   535篇
耳鼻咽喉   1315篇
儿科学   3637篇
妇产科学   2062篇
基础医学   16404篇
口腔科学   2207篇
临床医学   12217篇
内科学   26110篇
皮肤病学   1479篇
神经病学   11983篇
特种医学   3814篇
外国民族医学   1篇
外科学   17705篇
综合类   1658篇
现状与发展   1篇
一般理论   156篇
预防医学   10744篇
眼科学   3319篇
药学   8821篇
  1篇
中国医学   278篇
肿瘤学   8167篇
  2023年   609篇
  2022年   1066篇
  2021年   2368篇
  2020年   1410篇
  2019年   2402篇
  2018年   2803篇
  2017年   2039篇
  2016年   2379篇
  2015年   2745篇
  2014年   3958篇
  2013年   5559篇
  2012年   8471篇
  2011年   9100篇
  2010年   4966篇
  2009年   4635篇
  2008年   8025篇
  2007年   8520篇
  2006年   8074篇
  2005年   8127篇
  2004年   7672篇
  2003年   7072篇
  2002年   6820篇
  2001年   1198篇
  2000年   899篇
  1999年   1238篇
  1998年   1454篇
  1997年   1225篇
  1996年   950篇
  1995年   945篇
  1994年   800篇
  1993年   787篇
  1992年   671篇
  1991年   616篇
  1990年   546篇
  1989年   514篇
  1988年   508篇
  1987年   489篇
  1986年   431篇
  1985年   504篇
  1984年   575篇
  1983年   527篇
  1982年   699篇
  1981年   614篇
  1980年   535篇
  1979年   374篇
  1978年   353篇
  1977年   349篇
  1976年   291篇
  1975年   278篇
  1974年   283篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Three patients who presented with scrotal swelling within a few days of inguinal herniorrhaphy are reported. Ultrasonography scans performed in these patients all demonstrated features suspicious of recurrence of hernia. One patient underwent surgical exploration, which revealed only a scrotal haematoma without evidence of recurrent hernia. The other two patients were managed conservatively because clinically the swellings were regarded to be more compatible with haematoma. Both patients had subsequent resolution of the scrotal swelling with no clinical evidence of recurrence of hernia on follow‐up. It is concluded that sonographic diagnosis of recurrence of hernia shortly after inguinal herniorrhaphy can occasionally be misleading.  相似文献   
93.
A 68-year-old patient was scheduled for a thoracotomy. A double-lumen endobronchial tube was requested by the surgeon to facilitate operating conditions. Initial attempts at intubation by conventional methods were unsuccessful. The proximal ends of a 37F double-lumen tube were then shortened and a 4-mm fibreoptic bronchoscope was passed through the bronchial lumen. The patient's larynx was easily visualized and the bronchoscope was passed into the trachea. The double lumen tube was then advanced over the bronchoscope and correctly positioned. Shortening a double-lumen tube allows the use of a fibreoptic bronchoscope to aid in tracheal intubation in a patient whose larynx is difficult to visualize by conventional methods.  相似文献   
94.
Paul L. Booth  W. Eric Thomas   《Brain research》1991,548(1-2):163-171
Ramified microglial cells were investigated in primary cultures of dissociated cerebral cortical tissue from rats. The identification of these cells was confirmed through immunohistochemical staining with 7 monoclonal antibodies selective for microglia. While there was significant variation in staining intensity with different antibodies, all stained the identified ramified cells; the antibodies OX-42 and ED1 yielded the most intense immunoreactivity. Based on distinctive morphological features, the microglia could be identified in living cultures where they were monitored using time-lapse video recording. This technique revealed extremely dynamic features of cellular plasticity and motility. Ramified microglia exhibited constant and rapid alterations in the size and shape of their cell body with an associated extension and retraction of processes; concomitantly, the cells moved about in a circumscribed area. These features of plasticity and motility were unique to this cell type, and correlated with OX-42 immunostaining. The microglia also possessed a differentially high level of pinocytotic activity; this too was correlated with OX-42 staining. From the nature of their morphological plasticity and motility, high pinocytosis, and cellular distribution, it is hypothesized that the ramified microglia specifically function as a system of fluid cleansing in normal brain tissue.  相似文献   
95.
The original article to which this Erratum refers was published in Pharmacoepidemiology and Drug Safety 2005; 14: 239–247.  相似文献   
96.
97.
98.
Diarrhea in liver transplant recipients: etiology and management.   总被引:4,自引:0,他引:4  
Diarrhea is common after liver transplantation (LT). The true incidence of diarrhea in liver transplant recipients is unknown but possibly ranges from 10% to 43% based on a few published studies in other solid organ and bone marrow transplantation. Infectious etiologies, including cytomegalovirus (CMV), Clostridium difficile, and occasional atypical intestinal infections, are the most common causes. Diarrhea is also a frequent side effect of immunosuppressive medications. To variable extents, mycophenolate mofetil (MMF), cyclosporine A (CSA), tacrolimus, and sirolimus are all known to be associated with diarrhea. Rarely, graft-versus-host disease (GVHD), lymphoproliferative disorder, de novo inflammatory bowel disease (IBD), or colon cancer may present as diarrhea. Flare-up of preexisting IBD is also not uncommon after LT. However, the cause of acute diarrhea remains unidentified in 1 of 3 patients. This review summarizes the literature and provides recommendations on the management of acute diarrhea after LT. Although our focus is on LT, the etiology and management recommendations apply to most transplant recipients.  相似文献   
99.
INTRODUCTION: Angiotensin (Ang) IV enhances learning and memory in rats but there are strain differences in its effects in mice. Oxytocin (OT) also influences learning and memory in rats and mice and, in the light of the proposed effects of Ang IV on oxytocinase, the hypothesis that the effects of Ang IV on cognition in mice involve OT was tested. MATERIALS AND METHODS: The effects of Ang IV and OT, alone and combined, were determined in rat isolated uterine smooth muscle and in object recognition and forced swim tests in BKW mice. RESULTS: Ang potentiated the contractile effects of OT in the uterus. Neither peptide had any effect on object recognition nor locomotor activity. Ang IV had no effect in the forced swim test but abolished the effects of OT. CONCLUSIONS: Ang IV influences the actions of OT in vitro and in vivo, possibly by inhibition of oxytocinase, but the lack of effect of Ang IV on object recognition in BKW mice is unlikely to be a consequence of a deficiency endogenous OT. Unlike OT, Ang IV alone has no effect on learned helplessness in the forced swim test, an effect often used to predict potential antidepressant efficacy in humans.  相似文献   
100.
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