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   4696篇
  免费   248篇
  国内免费   9篇
耳鼻咽喉   60篇
儿科学   318篇
妇产科学   91篇
基础医学   596篇
口腔科学   120篇
临床医学   332篇
内科学   1146篇
皮肤病学   99篇
神经病学   198篇
特种医学   118篇
外科学   682篇
综合类   204篇
一般理论   1篇
预防医学   213篇
眼科学   173篇
药学   307篇
  1篇
中国医学   23篇
肿瘤学   271篇
  2023年   33篇
  2022年   78篇
  2021年   175篇
  2020年   83篇
  2019年   130篇
  2018年   156篇
  2017年   109篇
  2016年   128篇
  2015年   147篇
  2014年   185篇
  2013年   217篇
  2012年   349篇
  2011年   333篇
  2010年   195篇
  2009年   147篇
  2008年   251篇
  2007年   267篇
  2006年   198篇
  2005年   189篇
  2004年   169篇
  2003年   148篇
  2002年   133篇
  2001年   96篇
  2000年   101篇
  1999年   83篇
  1998年   38篇
  1997年   21篇
  1994年   20篇
  1993年   16篇
  1992年   63篇
  1991年   66篇
  1990年   53篇
  1989年   63篇
  1988年   38篇
  1987年   44篇
  1986年   38篇
  1985年   37篇
  1984年   17篇
  1983年   24篇
  1982年   21篇
  1979年   26篇
  1977年   12篇
  1976年   23篇
  1975年   13篇
  1974年   13篇
  1973年   19篇
  1972年   14篇
  1969年   15篇
  1968年   16篇
  1966年   14篇
排序方式: 共有4953条查询结果,搜索用时 31 毫秒
991.
Congenital submitral left ventricular aneurysm is a rare entity, seen predominantly in the natives of South and West Africa. We report two cases, highlighting the cross-sectional echocardiographic features in each case.  相似文献   
992.
993.
We studied cardiac tissues of a patient who died of severe rheumatic myocarditis. Multiple Aschoff lesions were present throughout both ventricles and auricles. Immunofluorescence studies showed large monocytoid cells staining with OKM1 and anti-Leu M-3 as well as anti-Ia. Scattered T cells in areas of focal myocarditis stained with OKT3. Parallel staining for cardiac myosin-heavy chain antigens showed patchy dissolution of cardiac muscle fibers and traces of cardiac myosin within large monocytoid Aschoff cells.  相似文献   
994.
995.
The effect of consumption of isabgol husk for 3 weeks on faecal excretion and serum levels of lipids was investigated in 11 adolescent girls. The consumption of isabgol husk lowered serum lipids and increased faecal fat.  相似文献   
996.
997.
BACKGROUND CONTEXT: Polymethylmethacrylate (PMMA) is the most commonly used bone cement for vertebroplasties to treat osteoporotic vertebral compression fractures (VCFs). Several studies have described the reaction of normal bone to PMMA, but it is still unclear how fractured osteoporotic bone responds to PMMA. PURPOSE: To describe the response of fractured osteoporotic bone to PMMA after vertebroplasty. STUDY DESIGN/SETTING: Case report. METHODS: A 69-year-old woman with a previous vertebroplasty at T8 to treat an osteoporotic VCF was admitted to the hospital after she developed lower extremity motor weakness, diffuse hypoesthesia and decreased rectal tone. Magnetic resonance imaging studies of the thoracic spine showed that she had severe spinal cord compression at the level of T8 and T9, as well as akyphotic deformity. A corpectomy of T8 and T9 was performed as part of a spinal cord decompression procedure. Tissue from vertebral body T8, intervertebral discs T7-T8 and T8-T9 and the PMMA implant were then submitted for histologic evaluation.RESULTS: Vertebral body T8 demonstrated viable bone trabeculae, osteoid. fibrosis, granulation tissue and multinucleated giant cells containing PMMA. Scattered necrotic bone fragments were identified throughout the vertebral body, most evident near the PMMA. PMMA leakage into the T7-T8 disc was identified without significant disc inflammation or necrosis. CONCLUSION: Fractured osteoporotic bone is capable of undergoing a reparative healing response after vertebroplasty using PMMA.  相似文献   
998.
Reports in the literature indicate the use of animal models for testing newer anti-leishmanial drugs in vivo. However, in certain established cell lines and macrophages in vitro models have the advantage over the in vivo system of simplicity and speed with which the results can be obtained. A simple in vitro system using peritoneal exudate macrophages of BALB/c mice infected with Leishmania donovani promastigotes has been tested for its use in determining the efficacy of several new drugs. Two well-established drugs, amphotericin B and sodium stibogluconate, as expected, could kill the intracellular parasites effectively. Two relatively new drugs not routinely used against leishmania, rifampicin and metronidazole at concentrations of 20 g/ml and 10 g/ml, respectively, were also able to kill the intracellular leishmania parasites effectively. Critical factors for drug testing in vitro have been elucidated: the most important being the temperature of incubation after infection.  相似文献   
999.
1000.

The current study focused on the pollution remediation of textile industry wastewater by using Chlorella pyrenoidosa in two different physical forms: free algal biomass and immobilized algal biomass. The hypothesis behind the present study was to analyze the pollution reduction efficiency of immobilized algal biomass and free algal biomass on comparative scale on the basis of the adsorption process which is directly proportional with the surface area of the adsorbate. So, in this context the immobilized form of algae could enhance the pollution reduction efficiency due to availability of more surface area. So, the textile industry wastewater was treated by both free algal biomass and immobilized algal biomass and the major wastewater contributors like nitrate, phosphate, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) were assessed before and after the treatment process. To conclude the optimum comparative results, the pH of wastewater was maintained constant, as it can capitalize or moderate the adsorption process (initial pH of was 8.2?±?0.1, but it was maintained to 8). The contamination remediation was found to be effective with immobilized algal biomass (46.7% of nitrate, 59.4% of phosphate, 83.1% BOD and 83.0% of COD) than free algal biomass (43.2% of nitrate, 56.7% of phosphate, 71.4% of BOD and 78.0% COD).

  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