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   6852篇
  免费   353篇
  国内免费   39篇
耳鼻咽喉   35篇
儿科学   149篇
妇产科学   176篇
基础医学   894篇
口腔科学   148篇
临床医学   620篇
内科学   1845篇
皮肤病学   213篇
神经病学   510篇
特种医学   119篇
外科学   655篇
综合类   21篇
预防医学   793篇
眼科学   79篇
药学   447篇
中国医学   21篇
肿瘤学   519篇
  2023年   54篇
  2022年   118篇
  2021年   250篇
  2020年   118篇
  2019年   236篇
  2018年   285篇
  2017年   132篇
  2016年   164篇
  2015年   165篇
  2014年   278篇
  2013年   379篇
  2012年   555篇
  2011年   648篇
  2010年   321篇
  2009年   288篇
  2008年   449篇
  2007年   437篇
  2006年   408篇
  2005年   451篇
  2004年   325篇
  2003年   351篇
  2002年   266篇
  2001年   48篇
  2000年   47篇
  1999年   53篇
  1998年   52篇
  1997年   58篇
  1996年   26篇
  1995年   27篇
  1994年   18篇
  1993年   22篇
  1992年   18篇
  1991年   26篇
  1990年   22篇
  1989年   25篇
  1988年   16篇
  1987年   15篇
  1986年   8篇
  1985年   9篇
  1984年   7篇
  1983年   8篇
  1980年   5篇
  1979年   4篇
  1978年   4篇
  1976年   4篇
  1974年   7篇
  1973年   5篇
  1966年   3篇
  1964年   3篇
  1963年   3篇
排序方式: 共有7244条查询结果,搜索用时 31 毫秒
991.
992.
IntroductionFarnesol is a sesquiterpenoid that has been described as impairing bacterial growth. Therefore, the goal of this study was to compare the in vitro postantimicrobial effect (PAE) of farnesol against Staphylococcus epidermidis with the corresponding values of most common practice antibiotics and also to evaluate the combined effect of farnesol with these antibiotics against planktonic and biofilm cells.MethodsAfter exposure of S epidermidis cells to farnesol and antibiotics at minimum inhibitory concentration for 1 hour, the cells were regrown in medium without any antimicrobial agent. Cellular viability was assessed by colony-forming units, every hour for 12 hours, and then, the PAE was determined. The combined effect of farnesol (0, 30, 100 and 300 μM) with vancomycin, tetracycline and rifampicin was also evaluated, by using these antibiotics at peak serum concentration.ResultsWhen PAE is concerned, it was found that cells grown in 100 μM of farnesol behaved similarly to cells that had never been in contact with farnesol, whereas a clear difference was obtained with cells exposed to 300 μM of farnesol, displaying a longer PAE. Farnesol showed a combined effect with the tested antibiotics against planktonic cells, although this was not so evident against biofilm cells.ConclusionsDespite the reduced efficacy against biofilm cells, farnesol seems to be a potential adjuvant therapeutic agent to antibiotics against S epidermidis planktonic cells. Moreover, its long PAE makes farnesol a potential candidate in the prevention of biofilm formation because it showed to be very effective against planktonic cells alone as well.  相似文献   
993.
We assessed the performance characteristics of two rK39 immunochromatographic tests, a direct agglutination test (DAT), and an indirect immunofluorescent antibody test (IFAT) in the site of a new epidemic of visceral leishmaniasis (VL) in northwestern Ethiopia. The study population was composed of 179 patients with suspected VL and 67 controls. The sensitivities of Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT in 35 polymerase chain reaction–confirmed VL cases were 94.3%, 91.4%, 91.4%, and 100%, respectively, and the specificities were 98.5%, 94%, 98.5%, and 98.5%, respectively. In a Bayesian latent class analysis of all 246 specimens, the estimated sensitivities were 90.5%, 89%, 88.8%, and 96% for Kalazar Detect®, DiaMed-IT Leish®, DAT, and IFAT, respectively; DAT showed the highest estimated specificity (97.4%). Both rK39 immunochromatographic tests perform as well as DAT, and are suitable for VL diagnosis in first-level health centers in this area of Ethiopia.  相似文献   
994.
Hypertension is 1 of the most prevalent cardiovascular risk factors; nevertheless, some studies have reported that the antecedent of hypertension does not impair prognosis in patients with established cardiovascular disease. The objective of this study was to describe the impact of hypertension on readmission and 1-year mortality in patients admitted to a single cardiology hospitalization unit. All consecutive hospitalizations in a single cardiology department through 10 months were included, and 1-year follow-up was performed. Clinical antecedents, risk factors, and main discharge diagnoses were collected. A total of 1,007 patients were included (mean age 71.1 ± 13.5 years). The antecedent of hypertension was present in 69.0%, and these patients had older mean age and higher prevalence of risk factors and previous cardiovascular disease. No differences in hospital discharge main diagnoses were observed according to the antecedent of hypertension. During a mean follow-up period of 404.82 ± 122.2 days, patients with hypertension had higher rates of rehospitalization for cardiac causes (31.1% vs 17.9%, p = 0.01) and of total (17.4% vs 9.3%, p <0.01) and cardiovascular (13.9% vs 5.9%, p <0.01) mortality. Multivariate analysis identified the antecedent of hypertension as an independent risk factor for cardiovascular readmission (hazard ratio 1.46, 95% confidence interval 1.10 to 1.98) and the combined end point of readmission or mortality (hazard ratio 1.45, 95% confidence interval 1.12 to 1.88); no independent association was observed for total mortality. In conclusion, hypertension was present in most patients admitted to a cardiology unit, and they had higher rates of rehospitalization and mortality at 1-year follow-up.  相似文献   
995.
Several works have endorsed a significant role of the immune system and inflammation in the pathogenesis of heart failure. As indirect evidence, an association between a low relative lymphocyte count (RLC%) and worse outcomes found in this population has been suggested. Nevertheless, the role of RLC% for risk stratification in a large and nonselected population of patients with acute heart failure (AHF) has not yet been determined. Thus, the aim of this study was to determine the association between low RLC% and 1-year mortality in patients with AHF and consequently to define whether it has any role for early risk stratification. A total of 1,192 consecutive patients admitted for AHF were analyzed. Total white blood cell and differential counts were measured on admission. RLC% (calculated as absolute lymphocyte count/total white blood cell count) was categorized in quintiles and its association with all-cause mortality at 1 year assessed using Cox regression. At 1 year, 286 deaths (24%) were identified. A negative trend was observed between 1-year mortality rates and quintiles of RLC%: 31.5%, 27.2%, 23.1%, 23%, and 15.5% in quintiles 1 to 5, respectively (p for trend <0.001). After thorough covariate adjustment, only patients in the lowest quintile (<9.7%) showed an increased risk for mortality (hazard ratio 1.76, 95% confidence interval 1.17 to 2.65, p = 0.006). When RLC% was modeled with restricted cubic splines, a stepped increase in risk was observed patients in quintile 1: those with RLC% values <7.5% and <5% showed 1.95- and 2.66-fold increased risk for death compared to those in the top quintile. In conclusion, in patients with AHF, RLC% is a simple, widely available, and inexpensive biomarker, with potential for identifying patients at increased risk for 1-year mortality.  相似文献   
996.
997.
998.
999.
1000.
The aim of the current pilot study was to compare two strategies in the application of the cognitive differentiation program of Integrated Psychological Therapy for people with schizophrenia. Twenty-six outpatients were randomly assigned to the application of the program in group sessions (CDg), or to its application in individualized sessions (CDi). The program provides cognitive exercises to promote better performance in cognition, and both groups of participants completed the same number of exercises following the same number of sessions per week. Outcomes were assessed on neuropsychological measures of attention, executive functioning and everyday memory, and everyday functioning. Effect sizes showed the absence of effects in everyday memory and social functioning, higher improvements in the CDi group in attention, and a higher improvement in the CDg condition in executive functioning. The results suggest that the program application model could be individualized, depending on patient-specific cognitive deficits.  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