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   8602篇
  免费   664篇
  国内免费   62篇
耳鼻咽喉   62篇
儿科学   215篇
妇产科学   191篇
基础医学   1531篇
口腔科学   121篇
临床医学   837篇
内科学   2138篇
皮肤病学   123篇
神经病学   790篇
特种医学   177篇
外科学   696篇
综合类   40篇
一般理论   1篇
预防医学   745篇
眼科学   130篇
药学   757篇
中国医学   28篇
肿瘤学   746篇
  2023年   103篇
  2022年   65篇
  2021年   326篇
  2020年   208篇
  2019年   277篇
  2018年   324篇
  2017年   235篇
  2016年   226篇
  2015年   319篇
  2014年   357篇
  2013年   506篇
  2012年   718篇
  2011年   723篇
  2010年   391篇
  2009年   368篇
  2008年   613篇
  2007年   654篇
  2006年   584篇
  2005年   534篇
  2004年   437篇
  2003年   435篇
  2002年   392篇
  2001年   21篇
  2000年   31篇
  1999年   39篇
  1998年   52篇
  1997年   44篇
  1996年   26篇
  1995年   23篇
  1994年   11篇
  1993年   15篇
  1992年   10篇
  1991年   9篇
  1989年   8篇
  1988年   8篇
  1987年   10篇
  1986年   10篇
  1985年   16篇
  1984年   11篇
  1982年   7篇
  1981年   22篇
  1980年   10篇
  1979年   6篇
  1978年   11篇
  1977年   13篇
  1976年   8篇
  1975年   8篇
  1974年   7篇
  1971年   6篇
  1966年   6篇
排序方式: 共有9328条查询结果,搜索用时 234 毫秒
81.

Some 70–80% of subjects with psychotic risk syndrome (PRS) have lifetime comorbidity, with depressive disorders being the most common. A high proportion of patients with PRS present nonspecific symptoms which can be confounding factors for diagnosis. Depressive and negative symptoms may be difficult to distinguish and it is important to differentiate them. The aim of this study is to assess the presence of depressive disorder in a child and adolescent sample of PRS and to examine the presence of negative symptoms and detect possible confounding characteristics between them and depressive symptoms. This is a naturalistic multi-site study with subjects who met PRS criteria. A sample of 89 PRS adolescent patients was included. Major depressive disorder (MDD) is the most prevalent comorbid disorder (34.83%). The sample was divided into patients who met criteria for MDD (PRS-MDD, n = 31) and those who did not have this disorder (PRS-ND, n = 44). We obtained significant differences in the attenuated negative symptoms (ANS) between PRS-MDD and PRS-ND (68.18 vs. 90.32%, respectively, p = 0.021). Subjects with MDD presented a higher score in ANS and Hamilton Depression Rating Scale (HDRS). Moreover, we obtained a correlation between negative symptomatology and HDRS score with a higher score on HDRS in subjects with higher negative symptom scores (r = 0.533, p < 0.001). More research is needed to fine tune differentiation between depressive and negative symptoms and learn more about the possible impact of MDD on PRS children and adolescents.

  相似文献   
82.
International Urology and Nephrology - The association between end-stage renal disease and cardiovascular mortality may be influenced through vascular alterations, in particular atherosclerosis and...  相似文献   
83.
84.
Neurosurgical Review - Brachial plexus injuries are among the rarest but at the same time the most severe complications of shoulder dislocation. The symptoms range from transient weakening or...  相似文献   
85.
European Spine Journal - Hyaluronic acid plays an essential role in water retention of the intervertebral disc (IVD) and thus provides flexibility and shock absorbance in the spine. Hyaluronic acid...  相似文献   
86.
The impact of carnivore parvovirus infection on wild populations is not yet understood; disease signs are mainly developed in pups and assessing the health of litters in wild carnivores has big limitations. This study aims to shed light on the virus dynamics among wild carnivores thanks to the analysis of 213 samples collected between 1994 and 2013 in wild ecosystems from Spain. We determined the presence of carnivore parvovirus DNA by real‐time PCR and sequenced the vp2 gen from 22 positive samples to characterize the strains and to perform phylogenetic analysis. The presence of carnivore parvovirus DNA was confirmed in 18% of the samples, with a higher prevalence detected in wolves (Canis lupus signatus, 70%). Fourteen sequences belonging to nine wolves, three Eurasian badgers (Meles meles), a common genet (Genetta genetta) and a European wildcat (Felis silvestris) were classified as canine parvovirus 2c (CPV‐2c); five sequences from three wolves, a red fox (Vulpes vulpes) and a stone marten (Martes foina) as CPV‐2b; and three sequences from a badger, a genet and a stone marten as feline parvovirus (FPV). This was the first report of a wildcat infected with a canine strain. Sequences described in this study were identical or very close related to others previously found in domestic carnivores from distant countries, suggesting that cross‐species transmission takes place and that the parvovirus epidemiology in Spain, as elsewhere, could be influenced by global factors.  相似文献   
87.
88.
89.
BackgroundMultiple myeloma (MM) in Hispanics has never been studied. We therefore sought to determine the clinical characteristics and overall survival in MM of Hispanics compared to non-Hispanic whites (NHW) and non-Hispanic blacks (NHB).Patients and MethodsA single-center analysis of 939 patients diagnosed with MM from 2000 to 2017 with a large representation of NHB (n = 489), Hispanics (n = 281), and NHW (n = 169) was conducted to evaluate outcomes and disease characteristics. We used the Connect MM Registry, a large US multicenter prospective observational study with newly diagnosed MM patients, as a validation cohort.ResultsHispanics had a higher incidence of MM compared to NHW. The median age at presentation was 5 years younger (median, 65 years) in Hispanics compared to NHW (median, 70 years), and patients were more likely to present with renal dysfunction (estimated glomerular filtration rate < 30 mL/min). Hispanics had a higher proportion of Revised International Staging System (R-ISS) stage I disease compared to NHW and NHB (P = .03), while there was no difference in cytogenetics between Hispanics and NHB/NHW. In the multivariate analysis, only high-risk disease and response to first-line therapy significantly affected survival.ConclusionIn this first and largest analysis of MM in Hispanics, we found that Hispanics present at a younger age, have a higher incidence of renal dysfunction, and have low R-ISS stage disease at presentation. With equal access to therapy, Hispanics have survival similar to NHW/NHB.  相似文献   
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