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   2842篇
  免费   160篇
  国内免费   82篇
耳鼻咽喉   9篇
儿科学   221篇
妇产科学   41篇
基础医学   332篇
口腔科学   78篇
临床医学   319篇
内科学   742篇
皮肤病学   88篇
神经病学   164篇
特种医学   401篇
外科学   175篇
综合类   48篇
预防医学   164篇
眼科学   27篇
药学   128篇
  2篇
中国医学   5篇
肿瘤学   140篇
  2023年   6篇
  2022年   20篇
  2021年   31篇
  2020年   30篇
  2019年   36篇
  2018年   57篇
  2017年   38篇
  2016年   39篇
  2015年   60篇
  2014年   78篇
  2013年   100篇
  2012年   94篇
  2011年   83篇
  2010年   123篇
  2009年   119篇
  2008年   98篇
  2007年   137篇
  2006年   122篇
  2005年   97篇
  2004年   63篇
  2003年   52篇
  2002年   54篇
  2001年   63篇
  2000年   58篇
  1999年   59篇
  1998年   138篇
  1997年   158篇
  1996年   135篇
  1995年   114篇
  1994年   117篇
  1993年   99篇
  1992年   37篇
  1991年   45篇
  1990年   40篇
  1989年   60篇
  1988年   54篇
  1987年   45篇
  1986年   51篇
  1985年   48篇
  1984年   28篇
  1983年   19篇
  1982年   26篇
  1981年   29篇
  1980年   26篇
  1979年   7篇
  1978年   11篇
  1977年   21篇
  1976年   26篇
  1975年   14篇
  1970年   5篇
排序方式: 共有3084条查询结果,搜索用时 15 毫秒
1.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
2.
3.
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2, PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α.  相似文献   
4.
Patients frequently present to the emergency room (ER) with mental status changes without obvious cause. The EEG is underused in this population. The authors investigated whether an abbreviated EEG (AbEEG) can be incorporated in the early evaluation of these patients to provide useful information. A 5-minute AbEEG was performed using a preformed electrode placement system on 25 patients who presented to the ER with mental status changes of unknown cause. AbEEG findings were categorized as normal, showing diffuse abnormalities, focal abnormalities, electrographic seizures, or uninterpretable. Using retrospective chart review, the authors determined if the cause of mental status change was a diffuse encephalopathy or a nonneurologic event (DENNE), a focal brain abnormality, nonconvulsive status epilepticus (NCSE), psychogenic, or unknown, and if particular AbEEG findings were associated with specific causes of altered sensorium. The AbEEG identified NCSE in two patients who presented with new-onset seizures. The presence of diffuse slowing on the AbEEG was highly suggestive of mental status changes due to DENNE. AbEEGs can be successfully incorporated in the early evaluation of patients who present to the ER with mental status changes of unknown cause and provide useful information in this setting.  相似文献   
5.
6.
7.
8.
This study elucidates the in vivo metabolic response of different liver cells after a single phagocytic challenge. In vivo glucose uptake of different tissues and isolated liver cells was determined by a sequential double labeling version of the 2-deoxyglucose technique. After latex administration, glucose uptake more than doubled in the liver, increased by about 50% in the spleen and lung and was not changed in muscle and testis. Within 10 min after intravenous injection of latex beads, neutropenia developed, with no change in the number of lymphocytes. This was accompanied by a marked influx of polymorphonuclear leukocytes into the liver. Latex was found in 52%, 35%, and 14% of the isolated Kupffer cells, polymorphonuclear leukocytes and endothelial cells, respectively. In vivo glucose uptake increased by 111%, 142%, and 43% in these cells. Glucose uptake by the latex-free hepatocytes was also elevated, presumably by way of intercellular signals between parenchymal and non-parenchymal liver cells. Indomethacin pretreatment resulted in the delay of neutrophil immigration into tissues without any change in the glucose response of different liver cells. Thus phagocytic stimulation in vivo results in marked neutropenia, migration of neutrophils into the liver, increased glucose uptake by phagocytic cells of the liver and enhanced glucose metabolism by the non-phagocytic parenchymal cells.  相似文献   
9.
10.
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