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   28133篇
  免费   1657篇
  国内免费   259篇
耳鼻咽喉   240篇
儿科学   547篇
妇产科学   605篇
基础医学   2809篇
口腔科学   676篇
临床医学   1988篇
内科学   8066篇
皮肤病学   383篇
神经病学   2539篇
特种医学   1075篇
外科学   5307篇
综合类   57篇
一般理论   5篇
预防医学   1050篇
眼科学   522篇
药学   1677篇
中国医学   55篇
肿瘤学   2448篇
  2023年   278篇
  2022年   237篇
  2021年   933篇
  2020年   597篇
  2019年   852篇
  2018年   1018篇
  2017年   739篇
  2016年   897篇
  2015年   910篇
  2014年   1244篇
  2013年   1521篇
  2012年   2319篇
  2011年   2206篇
  2010年   1270篇
  2009年   1226篇
  2008年   1905篇
  2007年   1849篇
  2006年   1746篇
  2005年   1730篇
  2004年   1629篇
  2003年   1394篇
  2002年   1248篇
  2001年   149篇
  2000年   148篇
  1999年   196篇
  1998年   173篇
  1997年   150篇
  1996年   138篇
  1995年   158篇
  1994年   128篇
  1993年   127篇
  1992年   113篇
  1991年   78篇
  1990年   86篇
  1989年   58篇
  1988年   49篇
  1987年   57篇
  1986年   56篇
  1985年   46篇
  1984年   48篇
  1983年   36篇
  1982年   54篇
  1981年   32篇
  1980年   31篇
  1979年   21篇
  1978年   13篇
  1977年   11篇
  1976年   11篇
  1975年   10篇
  1974年   11篇
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
81.
82.
Although the impact of dopamine on reward learning is well documented, its influence on other aspects of behavior remains the subject of much ongoing work. Dopaminergic drugs are known to increase risk-taking behavior, but the underlying mechanisms for this effect are not clear. We probed dopamine''s role by examining the effect of its precursor L-DOPA on the choices of healthy human participants in an experimental paradigm that allowed particular components of risk to be distinguished. We show that choice behavior depended on a baseline (ie, value-independent) gambling propensity, a gambling preference scaling with the amount/variance, and a value normalization factor. Boosting dopamine levels specifically increased just the value-independent baseline gambling propensity, leaving the other components unaffected. Our results indicate that the influence of dopamine on choice behavior involves a specific modulation of the attractiveness of risky options—a finding with implications for understanding a range of reward-related psychopathologies including addiction.  相似文献   
83.
84.
85.
86.
Gallium is an iron mimetic which has recently been repurposed as an antibacterial agent due to its capability to disrupt bacterial iron metabolism. In this study, the antibacterial activity of gallium nitrate [Ga(NO3)3] was investigated in complement-free human serum (HS) on 55 Pseudomonas aeruginosa clinical isolates from cystic fibrosis and non-cystic fibrosis patients. The susceptibility of P. aeruginosa to Ga(NO3)3 in HS was dependent on the bacterial ability to acquire iron from serum binding proteins (i.e., transferrin). The extent of serum protein degradation correlated well with P. aeruginosa growth in HS, while pyoverdine production did not. However, pyoverdine-deficient P. aeruginosa strains were unable to grow in HS and overcome iron restriction, albeit capable of releasing proteases. Predigestion of HS with proteinase K promoted the growth of all strains, irrespective of their ability to produce proteases and/or pyoverdine. The MICs of Ga(NO3)3 were higher in HS than in an iron-poor Casamino Acids medium, where proteolysis does not affect iron availability. Coherently, strains displaying high proteolytic activity were less susceptible to Ga(NO3)3 in HS. Our data support a model in which both pyoverdine and proteases affect the response of P. aeruginosa to Ga(NO3)3 in HS. The relatively high Ga(NO3)3 concentration required to inhibit the growth of highly proteolytic P. aeruginosa isolates in HS poses a limitation to the potential of Ga(NO3)3 in the treatment of P. aeruginosa bloodstream infections.  相似文献   
87.
88.
Abstract

This study is a single-center, retrospective analysis of postmenopausal women presenting with dyspareunia and vulvar pain, aiming to evaluate relative effectiveness of vestibular CO2 laser therapy as a treatment. Three monthly sessions of laser were performed to each patient and thereafter a three-months follow-up was stablished. A total number of 72 patients undergoing vestibular laser treatment were recruited from patient files in the period between 2016 and 2018. Among these, 39 women also received a concomitant treatment with ospemifene (60?mg/day) during the study period. There was a statistically significant reduction of all the symptoms in both groups up to the three month follow-up. Regarding dryness and dyspareunia, the relief tent to be more prominent in the ospemifene?+?laser group at all follow-ups and remained statistically significant at three-month follow-up. Specifically, vestibular dryness was significantly lower in the ospemifene?+?laser group compared with the laser treatment group (?87% vs???34%, respectively), and the vestibular health score started declining faster in the ospemifene?+?laser group. Although, additional research is needed to understand the mechanism of action, our data shows that a combination regimen of laser and ospemifene may improve clinical effectiveness for long-term treatment of symptoms associated with the under-recognized genitourinary syndrome of menopause.  相似文献   
89.
BackgroundThere is poor data on the prognostic role of Comprehensive Geriatric Assessment (CGA) in older patients with metastatic renal cell carcinoma (mRCC) treated with first line Tyrosine Kinase Inhibitors (TKIs).Materials and MethodsWe retrospectively reviewed the clinical charts of mRCC patients older than 70 years treated at our Institute with first-line Sunitinib or Pazopanib for at least 6 months. Every patient received a CGA at baseline and was identified as fit, vulnerable or frail according to Balducci's Criteria. We then assessed the impact of CGA category on survival, disease control and tolerability of TKIs.ResultsWe identified 86 eligible patients. Median age: 74.5 years, 56% males; 45.4% were fit, 37.2% vulnerable and 17.4% frail at CGA. There were no significant differences in the rate of Grade (G)1–2 and G3-4 toxicities, dose reduction rates, PFS and OS between Sunitinib and Pazopanib. Fit, vulnerable and frail patients achieved significantly different median PFS (18.9 vs 11.2 vs 5.1 months; p < 0.001) and OS (35.5 vs 14.6 vs 10.9 months; p < 0.001). Patients categorized as fit had higher chance of receiving a second-line treatment (66.6% vs 28.9% in vulnerable/frail; p = 0.002). The incidence of G3/4 events was significantly lower in the fit subgroup (19% vs 45% in vulnerable/frail; p = 0.0025).ConclusionsIn our retrospective single-center experience, CGA could accurately discriminate patients with higher risk of experiencing G3/4 toxicities, shorter PFS, and lower chance of receiving a second line treatment. CGA strongly impacted on OS, independently from International mRCC Database Consortium (IMDC) classification.  相似文献   
90.
Mechanical intravascular hemolysis is frequently observed following procedures on heart valves and uncommonly observed in native valvular disease. In most cases, its severity is mild. Nevertheless, it can be clinically significant and even life threatening, requiring multiple blood transfusions and renal replacement therapy. This paper reviews the current knowledge on mechanical intravascular hemolysis in valvular disease, before and after correction, focusing on pathophysiology, approach to diagnosis, and impact of other hematological conditions on the resultant anemia. The importance of a multidisciplinary management is underscored. Laboratory data are provided about subclinical hemolysis that is commonly observed following the implantation of surgical and transcatheter valve prostheses and devices. Finally, clinical scenarios are reviewed and current medical and surgical treatments are discussed, including alternative options for inoperable 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