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   3263篇
  免费   201篇
  国内免费   8篇
耳鼻咽喉   50篇
儿科学   198篇
妇产科学   70篇
基础医学   462篇
口腔科学   28篇
临床医学   226篇
内科学   631篇
皮肤病学   88篇
神经病学   144篇
特种医学   107篇
外科学   365篇
综合类   182篇
预防医学   293篇
眼科学   63篇
药学   292篇
中国医学   52篇
肿瘤学   221篇
  2023年   25篇
  2022年   26篇
  2021年   117篇
  2020年   61篇
  2019年   62篇
  2018年   83篇
  2017年   61篇
  2016年   72篇
  2015年   94篇
  2014年   128篇
  2013年   143篇
  2012年   226篇
  2011年   233篇
  2010年   152篇
  2009年   100篇
  2008年   171篇
  2007年   178篇
  2006年   183篇
  2005年   153篇
  2004年   118篇
  2003年   110篇
  2002年   97篇
  2001年   91篇
  2000年   90篇
  1999年   62篇
  1998年   17篇
  1997年   12篇
  1996年   27篇
  1995年   21篇
  1993年   18篇
  1992年   43篇
  1991年   44篇
  1990年   42篇
  1989年   47篇
  1988年   39篇
  1987年   24篇
  1986年   24篇
  1985年   28篇
  1984年   15篇
  1983年   14篇
  1979年   24篇
  1978年   15篇
  1977年   13篇
  1975年   13篇
  1974年   12篇
  1973年   21篇
  1972年   12篇
  1971年   17篇
  1970年   16篇
  1969年   16篇
排序方式: 共有3472条查询结果,搜索用时 922 毫秒
71.
72.
The concept of defining essential medicines and establishing a list of them was aimed to improve the availability of affordable medicines for the world''s poor. Access to essential medicines is a major determinant of health outcomes. Several countries have made substantial progress towards increasing access to essential medicines, but access to essential medicines in developing countries like India is not adequate. In this review we have tried to present the Indian scenario in respect to availability and accessibility of essential medicines over last one decade. To enhance the credibility of Indian healthcare system, procurement and delivery systems of essential medicines have to be strengthened through government commitment, careful selection, adequate public sector financing, efficient distribution systems, control on taxes and duties, and inculcating a culture of rational use of medicines in current and future prescribers.  相似文献   
73.
Objective:Lead (Pb) is a long-known poison of environment and industrial origin. Its prolonged exposure affects cellular material and alters cellular genetics and produces oxidative damages. In this study, we investigated the exposure of chronic sustained hypoxia or lead acetate alone or in combination with or without supplementation of α-tocopherol on hepatic oxidative and nitrosative stress in rats.Results:Exposure of both lead and hypoxia showed decreased body weight, altered serum lipid profile, oxidant and enzymatic antioxidants status, serum HIF-1α and VEGF concentrations. Simultaneous α-tocopherol supplementation showed beneficial effects to all these alterations. Histopathological observations also showed hepatic degenerative changes after lead or hypoxia exposure either alone or in combination, but remarkable improvement has been noticed after α-tocopherol supplementation.Conclusion:Supplementation of α-tocopherol is beneficial to counter both lead acetate and hypoxia induced hepatic cytotoxicities possibly by reducing oxidative and nitrosative stress.KEY WORDS: α-tocopherol, hypoxia, lead acetate, nitrosative stress, oxidative stress  相似文献   
74.
Pathogens in the gastrointestinal tract exist within a vast population of microbes. We examined associations between pathogens and composition of gut microbiota as they relate to Shigella spp./enteroinvasive Escherichia coli infection. We analyzed 3,035 stool specimens (1,735 nondiarrheal and 1,300 moderate-to-severe diarrheal) from the Global Enteric Multicenter Study for 9 enteropathogens. Diarrheal specimens had a higher number of enteropathogens (diarrheal mean 1.4, nondiarrheal mean 0.95; p<0.0001). Rotavirus showed a negative association with Shigella spp. in cases of diarrhea (odds ratio 0.31, 95% CI 0.17–0.55) and had a large combined effect on moderate-to-severe diarrhea (odds ratio 29, 95% CI 3.8–220). In 4 Lactobacillus taxa identified by 16S rRNA gene sequencing, the association between pathogen and disease was decreased, which is consistent with the possibility that Lactobacillus spp. are protective against Shigella spp.–induced diarrhea. Bacterial diversity of gut microbiota was associated with diarrhea status, not high levels of the Shigella spp. ipaH gene.  相似文献   
75.
Curcumin has been transformed to several diversely substituted bis-pyrrolizidino/thiopyrrolizidino oxindolo/acenaphthyleno curcuminoids via a sequential azomethine ylide cycloaddition reaction using isatins/acenaphthoquinone and proline/thioproline as the reagents. The products were separated via extensive chromatography and characterized by 1D/2D NMR and HRMS analysis.

Curcumin has been transformed to several diversely substituted bis-pyrrolizidino/thiopyrrolizidino oxindolo/acenaphthyleno curcuminoids via a sequential azomethine ylide cycloaddition reaction.  相似文献   
76.
Clinical Rheumatology - (1) Development and validation of a composite ultrasound score (cUSS) for the diagnosis of carpal tunnel syndrome (CTS). (2) To predict treatment response after local...  相似文献   
77.
Autoimmune hemolytic anaemia (AIHA) has traditionally been classified based on the temperature sensitivity of the autoagglutinins as warm (WAIHA), cold (CAIHA) and mixed type. Autoagglutinin may be of IgG or IgM type. The present prospective study was conducted to evaluate the profile of clinical picture, severity of haemolysis, treatment response of steroid. This study on patients of adult primary AIHA was conducted by taking complete history followed by detail physical examination. Laboratory investigations were performed to establish haemolytic anaemia and to assess severity of haemolysis. Immunehematological work up including blood grouping, direct antiglobulin test (DAT), IAT, antibody screening, adsorption elution was performed to diagnose type of AIHA. All cases were followed up to assess the response to prednisolone. All the data were collected and analysed by SPSS 19. Out of 62 primary AIHA cases, female were affected more than male (41:21). WAIHA is most common type (42, 67.8%) followed by mixed (20.9%) and cold AIHA (11.3%). Severity of haemolysis showed significant correlation with the DAT strength and not with type of AIHA. (P < 0.05) On oral prednisolone, 22 cases attended complete remission, while relapse, drug dependency and partial remission was achieved in 13, 9, 3 cases respectively. Severity of haemolysis in AIHA is directly related with DAT strength. WAIHA is most common type and can be managed with oral prednisolone (cr 45.2%), without red cell transfusion in most of cases. Mixed type AIHA cases were presented mostly with severe haemolysis, with minimum therapeutic response to prednisolone and maximum relapse/drug dependency.  相似文献   
78.
Secretory immunoglobulin A (S-IgA), coproantibody titre (antiamoebic) and IgA, IgG, IgM immunocytes in rectal mucosa were studied in 13 patients with amoebic liver abscess (ALA) prior to and 4-6 weeks after completion of antiamoebic therapy. Ten asymptomatic Entamoeba histolytica cyst passers and 17 healthy age and sex matched volunteers served as controls. Fecal S-IgA levels and counts of IgA bearing immunocytes in mucosa were significantly higher in patients with ALA and cyst passers as compared to healthy controls and showed a significant fall after treatment. Fecal antiamoebic antibodies were high in cyst passers and in cases of ALA after treatment. Raised levels of S-IgA and IgA class immunocyte counts probably indicate a local mucosal immune response directed at containing the infection.  相似文献   
79.
80.
Cardiovascular disease is common, affecting an increasing number of persons as the population ages. To combat this growing health problem, physicians use a multitude of medications in the treatment of their patients. Although pharmacologic therapy greatly enhances quality of life for a majority of patients, there is always the potential for an unfavorable reaction. For example, cardiovascular drugs can induce a vast array of adverse dermatologic responses. This article reviews the various cutaneous reaction patterns that can occur as a result of treatment with vasodilators and other antihypertensive drugs, anticoagulants and antiplatelet drugs, thrombolytic agents, and lipid-lowering agents.  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