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   7809篇
  免费   492篇
  国内免费   32篇
耳鼻咽喉   116篇
儿科学   256篇
妇产科学   131篇
基础医学   1133篇
口腔科学   333篇
临床医学   565篇
内科学   1945篇
皮肤病学   257篇
神经病学   660篇
特种医学   112篇
外科学   741篇
综合类   33篇
一般理论   2篇
预防医学   752篇
眼科学   248篇
药学   518篇
中国医学   35篇
肿瘤学   496篇
  2024年   7篇
  2023年   84篇
  2022年   169篇
  2021年   339篇
  2020年   193篇
  2019年   295篇
  2018年   290篇
  2017年   208篇
  2016年   197篇
  2015年   246篇
  2014年   335篇
  2013年   444篇
  2012年   687篇
  2011年   701篇
  2010年   338篇
  2009年   299篇
  2008年   477篇
  2007年   487篇
  2006年   453篇
  2005年   411篇
  2004年   388篇
  2003年   328篇
  2002年   284篇
  2001年   91篇
  2000年   101篇
  1999年   98篇
  1998年   42篇
  1997年   29篇
  1996年   23篇
  1995年   15篇
  1994年   19篇
  1993年   13篇
  1992年   30篇
  1991年   21篇
  1990年   14篇
  1989年   18篇
  1988年   21篇
  1987年   14篇
  1986年   19篇
  1985年   16篇
  1984年   9篇
  1983年   5篇
  1981年   5篇
  1980年   8篇
  1979年   7篇
  1977年   5篇
  1974年   5篇
  1973年   5篇
  1969年   5篇
  1965年   4篇
排序方式: 共有8333条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Arsenic pollution has become increasingly severe. It occurs as the result of geological processes and different human activities. Arsenic toxicity at the respiratory level occurs mainly by inhalation of products of coal combustion. The aim of this study was to evaluate sodium arsenite (As3+) toxicity in murine alveolar macrophages (AMs) in vitro and its association with the alterations in cell metabolism.

No changes in viability, apoptosis or cell area were detected in AMs treated with As3+ concentrations up to 2 μM for 24–96 h. A marked decrease in these end-points was observed for As3+ concentrations ranging from 2.5 μM to 10 μM.

Regarding the dynamics of the endo-exocytic process triggered by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell incorporation, no variations were detected for As3+ concentrations lower than 2 μM while higher concentrations markedly modified this response.

MTT specific activity, as a measure of cell metabolic activity, was not modified irrespective of the As3+ concentration assayed. However, nitroblue tetrazolium (NBT) specific activity, as a measure of superoxide anion generation, is responsive but only to low As3+ doses.

Although this study focuses on lung macrophages, the effects of As3+ described herein may also apply to the response of macrophages residing in other organs.

Arsenite modifies the metabolic and the oxidative status of AMs in vitro. When macrophages are in an As3+ rich medium, they exhibit a reduction in respiratory burst levels and lose their intrinsic capacity to respond to toxicants.  相似文献   

5.
6.
7.
Colorectal cancer is one of the best studied of all malignant diseases interms of genetics and/or molecular prognostic factors. These factors, and relationships with prognosis, may have important implications especially in the design of surgical and adjuvant chemo-radiotherapy options. However, the true prognostic significance of all known factors has yet to be realised. We have reviewed the literature with specific focus on the role of molecular markers involved in prognosis and the prediction of response to adjuvant treatment.  相似文献   
8.
9.
Bacterial infections are frequent in cadaveric organ donors and can be transmitted to the transplantation recipient, which could have devastating consequences for the recipients if adequate preventive measures are not adopted.
From the 355 consecutive brain dead cadaveric organ donors procured at our center in the last four years, 2000–2003, four of them (1.1%) had bacterial endocarditis as cause of death. The bacteria responsible for the endocarditis were Staphylococcus epidermidis, coagulase-negative Staphylococcus , Staphylococcus hominis and Streptococcus viridans , respectively. We performed five kidney and two liver transplantations on seven recipients. All donors and recipients received antibiotic treatment against the germ causing the respective endocarditis.
Infection by the bacteria responsible for the endocarditis in the respective donors was not transmitted to any of the recipients. Six of the seven recipients were alive with normal-functioning grafts after between 13 and 24 months' follow-up. Transplantectomy was performed on one kidney recipient due to thrombosis of the renal vein of the graft not related to the endocarditis.
Liver and kidney transplantation from donors dying from bacterial endocarditis can be performed without causing the transmission of infection to the recipient or the dysfunction of the graft.  相似文献   
10.
To examine the relationship between demographic, clinical and psychosocial variables and diabetes self-care management in Mexican type 2 diabetic patients. Cross-sectional study of 176 consecutive patients with type 2 diabetes aged 30-75 years, attending a tertiary health-care center in Mexico City. A brief medical history and previously validated questionnaires were completed. The study group consisted of 64 males/112 females, aged 55 +/- 11 years, mean diabetes duration of 12 +/- 8 years and HbA1c of 9.0 +/- 2.0%, 78.4% reported following the correct dose of diabetes pills or insulin, 58% ate the recommended food portions, and 44.3% did exercise three or more times per week. A good adherence to these three recommendations was observed in only 26.1% of the patients. These patients considered as a group were characterized by a greater knowledge about the disease (P < 0.00001), regular home blood glucose monitoring (P < 0.01), an inner perception of better diabetes control (P = 0.007), good health (P = 0.004) and better communication with their physician (P < 0.02). A poor adherence to two or the three main diabetes care recommendations was associated with a depressive state (OR 2.38, 95% CI 1.1-4.9, P < 0.01) and a history of excessive alcohol intake (OR 4.03, 95% CI 1.1-21.0, P = 0.03). Poor adherence to standard diabetes care recommendations is frequently observed in patients with type 2 diabetes attending a specialized health care center in Mexico City. Depression must be identified and treated effectively.  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