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   3034篇
  免费   151篇
  国内免费   79篇
耳鼻咽喉   18篇
儿科学   191篇
妇产科学   57篇
基础医学   340篇
口腔科学   80篇
临床医学   290篇
内科学   765篇
皮肤病学   86篇
神经病学   195篇
特种医学   407篇
外科学   264篇
综合类   47篇
预防医学   131篇
眼科学   113篇
药学   111篇
  2篇
肿瘤学   167篇
  2023年   5篇
  2022年   14篇
  2021年   38篇
  2020年   23篇
  2019年   29篇
  2018年   55篇
  2017年   40篇
  2016年   41篇
  2015年   54篇
  2014年   80篇
  2013年   85篇
  2012年   79篇
  2011年   88篇
  2010年   130篇
  2009年   116篇
  2008年   108篇
  2007年   154篇
  2006年   112篇
  2005年   111篇
  2004年   78篇
  2003年   89篇
  2002年   83篇
  2001年   76篇
  2000年   97篇
  1999年   67篇
  1998年   137篇
  1997年   165篇
  1996年   137篇
  1995年   117篇
  1994年   119篇
  1993年   102篇
  1992年   48篇
  1991年   49篇
  1990年   52篇
  1989年   62篇
  1988年   60篇
  1987年   47篇
  1986年   51篇
  1985年   48篇
  1984年   29篇
  1983年   17篇
  1982年   24篇
  1981年   29篇
  1980年   25篇
  1979年   6篇
  1978年   8篇
  1977年   18篇
  1976年   26篇
  1975年   15篇
  1970年   5篇
排序方式: 共有3264条查询结果,搜索用时 0 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.
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   
3.
4.
5.
Cutaneous aspergillosis is generally associated with immunosuppression, burns, and major trauma. Most cases are acquired by direct inoculation, although cutaneous involvement does occasionally occur with disseminated disease. Surgical wound infections caused by Aspergillus species are very unusual and to our knowledge have not been described in the setting of organ transplantation. We describe two liver transplant recipients who developed wound aspergillosis during a nosocomial outbreak of Aspergillus infection. Infection developed in the second and fourth postoperative week respectively, and in both cases wound appearance mimicked necrotizing fasciitis. Both patients died despite local debridement and antifungal therapy with amphotericin B. Aspergillus must be added to the list of potential pathogens of surgical wounds, especially in the setting of organ transplantation.  相似文献   
6.
7.
Interleukin-1 (IL-1) is a cytokine produced by the macrophage-monocyte system that has important effects on immunological responses and inflammatory reactions. Several clinical studies have shown that severe protein energy malnutrition adversely effects cell-mediated immune responses and the functional state of macrophages. The objective of this study was to analyse IL-1 production by adherent cells stimulated in vitro with lipopolysaccharide B (LPS) from patients with alcoholic cirrhosis of the liver and its possible relationship with nutritional states. Forty-five patients with alcoholic cirrhosis and 28 healthy donors were investigated. A combined index of nine anthropometric and biochemical parameters was used to evaluate nutritional status of cirrhotic patients, allowing a distinction to be made between those patients with acceptable nutrition (group I: 40%), those with slight malnutrition (group II: 37.7%), and those with severe malnutrition (group III: 22.3%). IL-1 activity was significantly lower in the cirrhosis patients than in the controls (P less than 0.001). This activity also was significantly lower in samples obtained from cirrhotics with severe malnutrition than in those with acceptable nutrition (P less than 0.05); the combined index and the sole anthropometric index gave the same results, suggesting that malnutrition may play a role in the immunoregulatory disturbances in the pathogenesis of alcoholic liver disease.  相似文献   
8.
9.
10.
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.  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