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   16657篇
  免费   888篇
  国内免费   76篇
耳鼻咽喉   118篇
儿科学   408篇
妇产科学   403篇
基础医学   2257篇
口腔科学   285篇
临床医学   1602篇
内科学   3761篇
皮肤病学   453篇
神经病学   1411篇
特种医学   284篇
外科学   1567篇
综合类   80篇
一般理论   11篇
预防医学   1888篇
眼科学   400篇
药学   1197篇
中国医学   73篇
肿瘤学   1423篇
  2024年   17篇
  2023年   143篇
  2022年   320篇
  2021年   570篇
  2020年   310篇
  2019年   493篇
  2018年   529篇
  2017年   357篇
  2016年   358篇
  2015年   476篇
  2014年   678篇
  2013年   902篇
  2012年   1352篇
  2011年   1501篇
  2010年   808篇
  2009年   632篇
  2008年   1155篇
  2007年   1156篇
  2006年   1086篇
  2005年   1057篇
  2004年   913篇
  2003年   843篇
  2002年   779篇
  2001年   102篇
  2000年   68篇
  1999年   91篇
  1998年   132篇
  1997年   107篇
  1996年   69篇
  1995年   78篇
  1994年   68篇
  1993年   48篇
  1992年   42篇
  1991年   37篇
  1990年   37篇
  1989年   36篇
  1988年   35篇
  1987年   29篇
  1986年   26篇
  1985年   23篇
  1984年   20篇
  1983年   19篇
  1982年   18篇
  1981年   16篇
  1980年   16篇
  1979年   9篇
  1978年   8篇
  1977年   8篇
  1976年   7篇
  1974年   6篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
Objective: Autism spectrum disorders (ASDs) appear in the early stages of neurodevelopment, and they remain constant throughout life. Currently, due to limitations in ASDs treatment, alternative approaches, such as nutritional interventions, have frequently been implemented. The aim of this narrative review is to gather the most relevant and updated studies about dietary interventions related to ASDs etiopathogenesis. Results: Our literature search focused on the gluten- and casein-free (GFCF) diet. The literature found shows the inexistence of enough scientific evidence to support a general recommendation of dietary intervention in children with ASD. Protocols and procedures for assessing risk and safety are also needed. Future lines: Prospective and controlled research studies with larger sample sizes and longer follow-up times are scarce and needed. In addition, studies considering an assessment of intestinal permeability, bacterial population, enzymatic, and inflammatory gastrointestinal activity are interesting to identify possible responders. Besides brain imaging techniques, genetic tests can also contribute as markers to evaluate the comorbidity of gastrointestinal symptoms.  相似文献   
82.
Objective: To evaluate antioxidant, cytotoxic, and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr. Methods: Gas chromatography-mass spec...  相似文献   
83.
Fibromyalgia is a chronic pain disease whose clinical symptomatology also includes different symptom domains: fatigue, sleep disturbances, morning stiffness, dyscognition, and psychological distress. These associated symptoms usually vary in frequency and intensity from patient to patient. Because the efficacy of monotherapy is limited, more severely affected patients frequently require drug combinations. There is, however, scarce scientific information concerning the benefits and risks of such combinations. To date, only ten studies investigating the efficacy and tolerability of two-drug combinations have been published; some of these studies are old and/or studied drugs that are now known to be of little or no interest in fibromyalgia management. Thus, when polytherapy is considered, therapeutic decisions must be based on data from monotherapy trials and a sound knowledge of the pharmacological profile of each drug. Well-designed clinical trials exploring specific drug combinations selected on the basis of potential additive or synergistic effects should be performed.  相似文献   
84.
85.
86.
87.
88.
OBJECTIVES:: To compare causes of death (CoDs) from two independent sources: National Basic Death File (NBDF) and deaths reported to the Spanish HIV Research cohort [Cohort de adultos con infección por VIH de la Red de Investigación en SIDA CoRIS)] and compare the two coding algorithms: International Classification of Diseases, 10th revision (ICD-10) and revised version of Coding Causes of Death in HIV (revised CoDe). METHODS:: Between 2004 and 2008, CoDs were obtained from the cohort records (free text, multiple causes) and also from NBDF (ICD-10). CoDs from CoRIS were coded according to ICD-10 and revised CoDe by a panel. Deaths were compared by 13 disease groups: HIV/AIDS, liver diseases, malignancies, infections, cardiovascular, blood disorders, pulmonary, central nervous system, drug use, external, suicide, other causes and ill defined. RESULTS:: There were 160 deaths. Concordance for the 13 groups was observed in 111 (69%) cases for the two sources and in 115 (72%) cases for the two coding algorithms. According to revised CoDe, the commonest CoDs were HIV/AIDS (53%), non-AIDS malignancies (11%) and liver related (9%), these percentages were similar, 57, 10 and 8%, respectively, for NBDF (coded as ICD-10). When using ICD-10 to code deaths in CoRIS, wherein HIV infection was known in everyone, the proportion of non-AIDS malignancies was 13%, liver-related accounted for 3%, while HIV/AIDS reached 70% due to liver-related, infections and ill-defined causes being coded as HIV/AIDS. CONCLUSION:: There is substantial variation in CoDs in HIV-infected persons according to sources and algorithms. ICD-10 in patients known to be HIV-positive overestimates HIV/AIDS-related deaths at the expense of underestimating liver-related diseases, infections and ill defined causes. CoDe seems as the best option for cohort studies.  相似文献   
89.
90.
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