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   5597篇
  免费   556篇
  国内免费   96篇
耳鼻咽喉   43篇
儿科学   134篇
妇产科学   246篇
基础医学   711篇
口腔科学   72篇
临床医学   593篇
内科学   1103篇
皮肤病学   97篇
神经病学   436篇
特种医学   381篇
外科学   734篇
综合类   174篇
预防医学   333篇
眼科学   105篇
药学   405篇
中国医学   27篇
肿瘤学   655篇
  2023年   27篇
  2022年   42篇
  2021年   125篇
  2020年   100篇
  2019年   178篇
  2018年   184篇
  2017年   125篇
  2016年   143篇
  2015年   190篇
  2014年   219篇
  2013年   330篇
  2012年   371篇
  2011年   380篇
  2010年   265篇
  2009年   221篇
  2008年   289篇
  2007年   296篇
  2006年   259篇
  2005年   273篇
  2004年   258篇
  2003年   216篇
  2002年   209篇
  2001年   179篇
  2000年   153篇
  1999年   154篇
  1998年   63篇
  1997年   61篇
  1996年   44篇
  1995年   38篇
  1994年   25篇
  1993年   32篇
  1992年   86篇
  1991年   85篇
  1990年   58篇
  1989年   59篇
  1988年   64篇
  1987年   58篇
  1986年   49篇
  1985年   55篇
  1984年   45篇
  1983年   33篇
  1982年   30篇
  1981年   16篇
  1980年   15篇
  1979年   12篇
  1978年   17篇
  1977年   14篇
  1975年   14篇
  1974年   11篇
  1958年   13篇
排序方式: 共有6249条查询结果,搜索用时 31 毫秒
181.
182.
183.
Purpose: To evaluate safety, tolerability, and seizure outcome data during long‐term treatment with once‐daily adjunctive perampanel (up to 12 mg/day) in patients with refractory partial‐onset seizures. Methods: Study 307 was an extension study for patients completing the double‐blind phase of three pivotal phase III trials (studies 304, 305, and 306). The study consisted of two phases: an open‐label treatment phase (including a 16‐week blinded conversion period and a planned 256‐week maintenance period) and a 4‐week follow‐up phase. Patients were blindly titrated during the conversion period to their individual maximum tolerated dose (maximum 12 mg/day). Adverse events (AEs) were monitored throughout the study and seizure frequency recorded. The interim data cutoff date for analyses was December 1, 2010. Key Findings: In total, 1,218 patients were enrolled in the study. At the interim cutoff date, 1,186 patients were in the safety analysis set; 1,089 (91.8%) patients had >16 weeks of exposure to perampanel, 580 (48.9%) patients had >1 year of exposure, and 19 (1.6%) patients had >2 years of exposure. At the interim analysis, 840 (70.8%) patients remained on perampanel treatment. The large majority of patients (n = 1,084 [91%]) were titrated to 10 mg or 12 mg/day. Median (range) duration of exposure was 51.4 (1.1–128.1) weeks. Treatment‐emergent AEs were reported in 87.4% of patients. The most frequent were dizziness (43.9%), somnolence (20.2%), headache (16.7%), and fatigue (12.1%). Serious AEs were reported in 13.2% of patients. In the intent‐to‐treat analysis set (n = 1,207), the frequency of all seizures decreased over the first 26 weeks of perampanel treatment in patients with at least 26 weeks of exposure to perampanel (n = 1,006 [83.3%]); this reduction was maintained in patients with at least 1 year of exposure (n = 588 [48.7%]). The overall median percent changes in seizure frequency in patients included in each 13‐week interval of perampanel treatment were ?39.2% for weeks 14–26 (n = 1,114), ?46.5% for weeks 40–52 (n = 731), and ?58.1% for weeks 92–104 (n = 59). Overall responder rates in patients included in each 13‐week interval of perampanel treatment were 41.4% for weeks 14–26 (n = 1,114), 46.9% for weeks 40–52 (n = 731), and 62.7% for weeks 92–104 (n = 59). During the blinded conversion period, the reduction in seizure frequency in patients previously randomized to placebo (?42.4%, n = 369) was similar to that in patients previously randomized to perampanel (?41.5%, n = 817). Significance: Consistent with pivotal phase III trials, these interim results demonstrated that perampanel had a favorable tolerability profile in patients with refractory partial‐onset seizures over the longer term. The decrease in seizure frequency was consistent and maintained in those patients over at least 1 year of perampanel exposure.  相似文献   
184.
185.
The following abstracts won prizes at the 153rd East Midlands Surgical Society meeting held on 9 November 2012 at Leicester General Hospital. First prize was won by George et al. The paper by Ogunbiyi et al was placed second and the paper by Khanna et al was placed third.  相似文献   
186.
Plasmapheresis not only removes circulating antibodies but also modulates cellular immunity, including lymphocyte subsets. To investigate the effect of double‐filtration plasmapheresis (DFPP) on the ratio of lymphocyte subsets in patients with myasthenia gravis (MG), we examined the percentages of B‐cells, T‐cells, T helper (Th) cells, T suppressor (Ts) cells, natural killer (NK) cells, NKT cells, and Th/Ts ratio before and after a single DFPP session and after a course of DFPP. A total of 26 patients were recruited; their peripheral blood lymphocyte subsets were assayed using flow cytometry. After a single session of DFPP treatment, the percentages of T‐cells (P = 0.0200), Th cells (P = 0.0178), and the Th/Ts ratio (P = 0.0309) decreased significantly, whereas the percentage of NK cells (P = 0.0007) increased significantly. More importantly, after one course of DFPP treatment, the reduced clinical quantitative MG (QMG) score was correlated with the decrease of the percentage of T‐cells (r = 0.5005, P = 0.0092). Fourteen thymectomized MG patients had decreased percentages of T‐cells (P = 0.0304) and Th cells (P = 0.0444), whereas they had increased NK cells (P = 0.0197) after a single DFPP session. Here, transiently decreased percentages of T‐cells after the full DFPP course could enhance the effectiveness of plasmapheresis for MG patients.  相似文献   
187.
Background : The association between QT interval and mortality has been demonstrated in large, prospective population‐based studies, but the strength of the association varies considerably based on the method of heart rate correction. We examined the QT‐mortality relationship in the Framingham Heart Study (FHS). Methods : Participants in the first (original cohort, n = 2,365) and second generation (offspring cohort, n = 4,530) cohorts were included in this study with a mean follow up of 27.5 years. QT interval measurements were obtained manually using a reproducible digital caliper technique. Results : Using Cox proportional hazards regression adjusting for age and sex, a 20 millisecond increase in QTc (using Bazett's correction; QT/RR1/2 interval) was associated with a modest increase in risk of all‐cause mortality (HR 1.14, 95% CI 1.10–1.18, P < 0.0001), coronary heart disease (CHD) mortality (HR 1.15, 95% CI 1.05–1.26, P = 0.003), and sudden cardiac death (SCD, HR 1.19, 95% CI 1.03–1.37, P = 0.02). However, adjustment for heart rate using RR interval in linear regression attenuated this association. The association of QT interval with all‐cause mortality persisted after adjustment for cardiovascular risk factors, but associations with CHD mortality and SCD were no longer significant. Conclusion : In FHS, there is evidence of a graded relation between QTc and all‐cause mortality, CHD death, and SCD; however, this association is attenuated by adjustment for RR interval. These data confirm that using Bazett's heart rate correction, QTc, overestimates the association with mortality. An association with all‐cause mortality persists despite a more complete adjustment for heart rate and known cardiovascular risk factors.  相似文献   
188.
189.
190.
In this study, hierarchically mesoporous silica (HMS) with properties such as high specific surface area, high photostability, and no cellular toxicity was synthesized. The synthesized silica can be considered as an excellent carrier candidate material. Through the use of nitrogen adsorption and desorption analysis, the shape of the hysteresis loop implied the presence of mesoporous structures in the HMS powder. In addition, the encapsulation efficiency was more than 90%. These results showed that avobenzone could be encapsulated into the HMS powder because of its high specific surface area and pore volume. Additionally, X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and UV-visible (Vis) spectrophotometry were used to prove that the hierarchically mesoporous silica was able to effectively encapsulate avobenzone. In addition, the new synthetic sunscreen kept its excellent UVA absorption properties after being encapsulated.

This study provides a preparing method for mesoporous silica to effectively encapsulate with avobenzone.  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