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   2719篇
  免费   215篇
  国内免费   11篇
耳鼻咽喉   21篇
儿科学   101篇
妇产科学   112篇
基础医学   411篇
口腔科学   88篇
临床医学   346篇
内科学   551篇
皮肤病学   117篇
神经病学   153篇
特种医学   42篇
外科学   187篇
综合类   52篇
一般理论   4篇
预防医学   226篇
眼科学   71篇
药学   223篇
中国医学   50篇
肿瘤学   190篇
  2024年   8篇
  2023年   53篇
  2022年   169篇
  2021年   223篇
  2020年   164篇
  2019年   190篇
  2018年   188篇
  2017年   107篇
  2016年   140篇
  2015年   115篇
  2014年   156篇
  2013年   187篇
  2012年   245篇
  2011年   233篇
  2010年   115篇
  2009年   81篇
  2008年   113篇
  2007年   103篇
  2006年   87篇
  2005年   90篇
  2004年   59篇
  2003年   31篇
  2002年   30篇
  2001年   4篇
  2000年   1篇
  1999年   6篇
  1998年   2篇
  1997年   3篇
  1996年   2篇
  1995年   2篇
  1994年   3篇
  1993年   2篇
  1991年   1篇
  1990年   1篇
  1988年   5篇
  1987年   7篇
  1986年   2篇
  1985年   5篇
  1984年   2篇
  1980年   1篇
  1979年   4篇
  1977年   1篇
  1976年   1篇
  1973年   2篇
  1936年   1篇
排序方式: 共有2945条查询结果,搜索用时 15 毫秒
31.
32.
Prenatal psychopathology may have an adverse impact on mother and baby, but few women receive treatment. We offered a 10-week mindfulness yoga (M-Yoga) intervention to psychiatrically high-risk pregnant women as an alternative to pharmacological treatment. Participants (N = 18) were primiparous, 12–26 weeks pregnant, and had elevated scores (>9) on the Edinburgh Postnatal Depression Screen at baseline. In addition to a baseline diagnostic assessment, women completed self-ratings on depression, mindfulness, and maternal-fetal attachment before and after M-Yoga. Findings suggest that M-Yoga was feasible, accepted and effective. Symptoms of depression were significantly reduced (p = 0.025), while mindfulness (p = 0.007) and maternal-fetal attachment (p = 0.000) significantly increased. Overall, this pilot study is the first to demonstrate that M-Yoga may be an effective treatment alternative or augmentation to pharmacotherapy for pregnant women at high risk for psychopathology.  相似文献   
33.
34.
35.
36.
37.
Aim:  Iran's health-care system has witnessed profound changes in the last decades. Despite its progress, the system has currently faced many challenges in one of the important subsystems, nursing. The present review article aimed to present an overview of the opportunities and challenges of the Iranian nursing system, based on recent literature.
Methods:  A broad search of the English and Persian-language literature was carried out, incorporating both electronic and manual components from 1999 to 2009. The results of the investigations among the searched literature are summarized.
Results:  The major challenges are nursing shortages, job dissatisfaction, poor social position of nurses, the gap between theory and practice, lack of community-based nursing care, lack of an appropriate student recruiting system, and shortages in the nursing educational curriculums.
Conclusion:  The authors believe that media, political and public support play a pivotal role in improving the image of nursing in society, increasing motivation among Iranian nurses, and promoting the sociocultural climate and the welfare of nurses, which will result in higher levels of quality of care as well as greater patient satisfaction.  相似文献   
38.
AIM: Venous obstruction following transvenous device implantation rarely cause immediate clinical problems. When lead revision or device upgrade is indicated, venous obstruction become a significant challenge. The aim of this study was to determine the predictors of venous obstruction after transvenous device implantation, and to asess likely effects of antiplatelet/anticoagulant drugs in preventing venous thrombosis. METHODS AND RESULTS: Between March 2005 and July 2006, contrast venography was performed in 100 patients who were candidates for generator change, lead revision, or device upgrade. Vessel patency was graded as either completely obstructed, partially obstructed (>70%), or patent. The incidence of venous obstruction was 26%, with 9% of patients having total obstruction and 17% of patients exhibiting partial obstruction. No statistically significant differences between obstructed and non-obstructed patients were seen for age, sex, indication for device implantation, atrial fibrillation, cardiothoracic ratio, insulation material, operative technique, device type, and manufacturer (all Ps > 0.05). In a univariate analysis, multiple leads (P = 0.033), and presence of dilated cardiomyopathy (P = 0.036) were associated with higher risk of venous obstruction, whereas anticoagulant/antiplatelet therapy (P = 0.047) significantly reduced incidence of venous obstruction. Multivariate logistic regression analysis showed that only number of the leads (P = 0.039, OR: 2.22, and 95% CI: 1.03-4.76) and antiplatelet/anticoagulant therapy (P = 0.044, OR: 2.79, and 95% CI: 0.98-7.96) were predictors of venous obstruction. CONCLUSION: Total or partial obstruction of the access veins occurs relatively frequently after pacemaker or ICD implantation. Multiple pacing or ICD leads are associated with an increased risk of venous obstruction, whereas antiplatelet/anticoagulant therapy appears to have a preventive effect on development of access vein thrombosis.  相似文献   
39.
BACKGROUND: Approximately 30% of all accessory pathways (APs) are located in the septal area, and understanding the electrocardiographic and electrophysiologic of these APs is crucial for safe and effective ablation of these pathways. OBJECTIVE: In this study, the electrocardiographic and electrophysiologic characteristics of anteroseptal, midseptal, and posteroseptal APs were investigated in detail to elucidate unique electrical properties of APs in each location. METHODS: From April 2002 to October 2006, a total of 120 patients with a septal AP-mediated tachycardia were enrolled in the study. A detailed examination including electrocardiographic analysis and electrophysiologic study was performed in all patients. RESULTS: A total of 120 patients, including 98 patients with posteroseptal APs, 14 patients with anteroseptal APs, and 8 patients with midseptal APs, were studied. The anteroseptal APs could be differentiated from the midseptal APs by the 2 or more positive delta waves in inferior leads, whereas there is significant overlap in electrocardiographic features of midseptal and posteroseptal APs. The mean tachycardia cycle length was significantly shorter in patients with midseptal AP compared with those with anteroseptal and posteroseptal APs (284 +/- 49 ms vs 342 +/- 46 ms vs 350 +/- 68 ms, P = .03). The AH interval during tachycardia was also shorter in patients with midseptal APs (149 +/- 16 ms vs 200 +/- 51 ms vs 168 +/- 48 ms, P = .04). The patients with posteroseptal AP had a significantly higher incidence of atrial fibrillation (35%) than those with either midseptal (12%) or anteroseptal (14%) APs (P = .04). The patients with posteroseptal APs also had a significantly shorter antegrade effective refractory period of the AP (276 +/- 54 ms) than those with either midseptal (313 +/- 71 ms) or anteroseptal (325 +/- 61) APs (P = .036). CONCLUSION: Electrocardiographic analysis is a reliable method for differentiation of the anteroseptal from the midseptal APs, whereas the same is not true for the midseptal and posteroseptal APs. Midseptal APs were characterized by faster orthodromic tachycardia, whereas posteroseptal APs had a higher inducibility of atrial fibrillation.  相似文献   
40.
The newly identified tripartite motif (TRIM) family of proteins mediate innate immunity and other critical cellular functions. Here we show that TRIM21, which mediates the autoimmune diseases rheumatoid arthritis, systemic lupus erythematosus, and Sjögren''s syndrome, is a previously undescribed IgG receptor with a binding mechanism unlike known mammalian Fcγ receptors. TRIM21 simultaneously targets conserved hot-spot residues on both Ig domains of the Fc fragment using a PRYSPRY domain with a preformed multisite interface. The binding sites on both TRIM21 and Fc are highly conserved to the extent that the proteins are functionally interchangeable through murine, canine, primate, and human species. Pre-steady-state analysis exposes mechanistic conservation at the level of individual residues, which make the same energetic and kinetic contributions to binding despite varying in sequence. Together, our results reveal that TRIM21 is a previously undescribed type of IgG receptor based on a non-Ig scaffold whose interaction at the fundamental level—structural, thermodynamic, and kinetic—is evolutionarily conserved.  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