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   5651篇
  免费   272篇
  国内免费   33篇
耳鼻咽喉   109篇
儿科学   267篇
妇产科学   129篇
基础医学   470篇
口腔科学   235篇
临床医学   504篇
内科学   1315篇
皮肤病学   103篇
神经病学   277篇
特种医学   109篇
外科学   914篇
综合类   349篇
一般理论   4篇
预防医学   360篇
眼科学   186篇
药学   387篇
中国医学   32篇
肿瘤学   206篇
  2024年   4篇
  2023年   86篇
  2022年   280篇
  2021年   397篇
  2020年   183篇
  2019年   200篇
  2018年   228篇
  2017年   151篇
  2016年   185篇
  2015年   244篇
  2014年   281篇
  2013年   286篇
  2012年   425篇
  2011年   397篇
  2010年   231篇
  2009年   195篇
  2008年   303篇
  2007年   288篇
  2006年   297篇
  2005年   276篇
  2004年   227篇
  2003年   213篇
  2002年   169篇
  2001年   46篇
  2000年   49篇
  1999年   35篇
  1998年   28篇
  1997年   18篇
  1996年   19篇
  1995年   13篇
  1994年   15篇
  1993年   7篇
  1992年   22篇
  1991年   18篇
  1990年   19篇
  1989年   13篇
  1988年   14篇
  1987年   13篇
  1986年   5篇
  1985年   10篇
  1984年   5篇
  1983年   6篇
  1980年   5篇
  1979年   5篇
  1977年   5篇
  1974年   6篇
  1973年   4篇
  1972年   4篇
  1970年   5篇
  1969年   4篇
排序方式: 共有5956条查询结果,搜索用时 0 毫秒
31.
32.
33.
Wilting, especially of the leaves, was observed as an initial symptom of arsenate [As(V)] to Ludwigia octovalvis (Jacq.) P. H. Raven. The plants tolerated As(V) levels of 39 mg kg?1 for as long as 35 days of exposure. After 91 days, the maximum concentration of As uptake in the plant occurred at As(V) concentration of 65 mg kg?1 while As concentration in the stems, roots and leaves were 6139.9 ± 829.5, 1284.5 ± 242.9 and 1126.1 ± 117.2 mg kg?1, respectively. In conclusion, As(V) could cause toxic effects in L. octovalvis and the plants could uptake and accumulate As in plant tissues.  相似文献   
34.
Mass media is an important vehicle for health promotion in developing countries. In Bangladesh multiple media campaigns are being carried out to educate people about HIV/AIDS. We examined the extent of HIV/AIDS knowledge and the association of exposure to mass media among women in Bangladesh. The Bangladesh Demographic and Health Survey (BDHS) provides data for this article. We found that media exposure (combined index of television, radio, and newspaper) was a highly significant predictor of women's knowledge about HIV and AIDS. Other significant predictors of HIV knowledge include women's education, age, employment, and urban residence.  相似文献   
35.
36.
We used a lentiviral vector bearing the viral spike protein to detect neutralizing antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV) in persons from the Eastern Province of Saudi Arabia. None of the 268 samples tested displayed neutralizing activity, which suggests that MERS-CoV infections in humans are infrequent in this province.  相似文献   
37.
Neurotherapeutic potentials of Centella asiatica and its reputation to boost memory, prevent cognitive deficits and improve brain functions are widely acknowledged. The plant's bioactive compounds, i.e. asiaticoside, madecassoside and asiatic acid were reported to have central nervous system (CNS) actions, particularly in protecting the brain against neurodegenerative disorders. Hence, it is important for these compounds to cross the blood-brain barrier (BBB) to be clinically effective therapeutics. This study aimed to explore the capability of asiaticoside, madecassoside and asiatic acid to cross the BBB using in vitro BBB model from primary porcine brain endothelial cells (PBECs). Our findings showed that asiaticoside, madecassoside and asiatic acid are highly BBB permeable with apparent permeability (Papp) of 70.61 ± 6.60, 53.31 ± 12.55 and 50.94 ± 10.91 × 10?6 cm/s respectively. No evidence of cytotoxicity and tight junction disruption of the PBECs were observed in the presence of these compounds. Asiatic acid showed cytoprotective effect towards the PBECs against oxidative stress. This study reported for the first time that Centella asiatica compounds demonstrated high capability to cross the BBB, comparable to central nervous system drugs, and therefore warrant further development as therapeutics for the treatment of neurodegenerative diseases.  相似文献   
38.
39.
Objectives:To assess National Institutes of Health Stroke Scale (NIHSS), stroke volume, biochemical, and blood parameters for the prediction of one-month mortality in stroke patientsMethods:The study had retrospective design and 75 patients were involved that presented to a hospital Emergency Department between January 2016 and December 2017 in Adiyaman, Turkey diagnosed with acute ischemic cerebral infarction. The patients were divided into 2 groups according to whether mortality occurred within one month. Values for NIHSS, stroke volume, Glasgow Coma Scale, and blood parameters were compared between the groups.Results:Values for Glasgow Coma Scale p=0.002, NIHSS p=0.001, stroke volume p=0.003, monocyte/HDL ratio p=0.047, neutrophils p=0.01, white blood cell p=0.007, calcium p=0.016, and albumin p=0.027 were statistically significant for the prediction of one-month mortality. There were no significant differences between the groups for other parameters.Conclusion:The clinical, laboratory, and radiological findings individually provide significant support for the short-term prognosis of stroke. The evaluation of these results together can provide a clearer advance understanding of a prognosis to better manage the course of the disease and prevent death.

Stroke is the third most common cause of death for patients presenting to emergency departments worldwide.1 Thus, to foresee possible mortality and morbidity in stroke cases, adoption of the right treatment and follow-up approach is important.2 The quality of the health service in a hospital emergency department depends on the successful prediction of the course of the disease and the clinical picture that may arise. Being aware of the prognosis of the disease in advance is important not only for making optimal treatment decisions but also for correctly informing the patient and managing health expenditures.In the literature, clinical parameters such as C reactive protein (CRP), red cell distribution width (RDW), neutrophil/lymphocyte ratio, and routine blood parameters such as albumin, infarct volume on admission, and National Institutes of Health Stroke Scale (NIHSS) score have previously been defined for the prediction of mortality in stroke cases.2-5 Pro-brain natriuretic peptides and pro-atrial natriuretic peptides, 2 other biochemical parameters that are not among the routine blood parameters, have also been shown to be important markers of stroke prognosis.6,7This study aimed to evaluate the association of clinical, biochemical, and radiological parameters with one-month mortality in patients that presented to the emergency service and received a diagnosis of ischemic stroke.  相似文献   
40.
Objective Familial Mediterranean fever (FMF) is an autosomal recessive recurrent polyserositis with a higher prevalence in some ethnic groups, including Turks. Mutations in the FMF gene (MEFV) were found associated with FMF. The aim of this study was to analyze MEFV gene mutations in FMF patients to gain insight into the mutation phenotype correlation.Objectives We analyzed the most frequent mutations (M680I, M694V, V726A, and E148Q) in a group of young male Turkish FMF patients using an amplification refractory mutation system and a commercial kit.Results M694V mutation was detected in 80% of the patients. After making a strict diagnostic discrimination between arthralgia and arthritis, arthritis was present in 71% of homozygous and 29.4% of heterozygous patients for M694V mutation. Other mutations were not found to correlate with specific symptoms or findings.Conclusion The homozygosity of M694V mutation in the MEFV gene is associated with arthritis in FMF patients.  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