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   204144篇
  免费   2988篇
  国内免费   158篇
耳鼻咽喉   1379篇
儿科学   7049篇
妇产科学   3297篇
基础医学   20864篇
口腔科学   2448篇
临床医学   15085篇
内科学   37792篇
皮肤病学   1109篇
神经病学   19760篇
特种医学   10660篇
外国民族医学   1篇
外科学   32652篇
综合类   2531篇
一般理论   12篇
预防医学   19208篇
眼科学   3301篇
药学   11078篇
中国医学   678篇
肿瘤学   18386篇
  2023年   249篇
  2022年   353篇
  2021年   823篇
  2020年   510篇
  2019年   720篇
  2018年   22560篇
  2017年   17867篇
  2016年   20213篇
  2015年   1865篇
  2014年   2007篇
  2013年   2247篇
  2012年   9340篇
  2011年   23296篇
  2010年   20167篇
  2009年   12738篇
  2008年   21499篇
  2007年   23664篇
  2006年   2614篇
  2005年   4098篇
  2004年   5043篇
  2003年   5889篇
  2002年   3952篇
  2001年   519篇
  2000年   604篇
  1999年   433篇
  1998年   498篇
  1997年   426篇
  1996年   250篇
  1995年   248篇
  1994年   220篇
  1993年   148篇
  1992年   105篇
  1991年   154篇
  1990年   170篇
  1989年   139篇
  1988年   96篇
  1987年   85篇
  1986年   65篇
  1985年   66篇
  1984年   54篇
  1983年   61篇
  1982年   60篇
  1980年   68篇
  1974年   46篇
  1938年   84篇
  1937年   55篇
  1935年   57篇
  1934年   53篇
  1932年   58篇
  1930年   52篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The aim of this retrospective single-center study was to investigate the short- and long-term impact of neutropenia occurring within the first year after kidney transplantation, with a special emphasis on different neutropenia grades. In this unselected cohort, 225/721 patients (31%) developed 357 neutropenic episodes within the first year post-transplant. Based on the nadir neutrophil count, patients were grouped as neutropenia grade 2 (<1.5–1.0*109/l; = 105), grade 3 (<1.0–0.5*109/l; = 65), and grade 4 (<0.5*109/l; = 55). Most neutropenia episodes were presumably drug-related (71%) and managed by reduction/discontinuation of potentially responsible drugs (mycophenolic acid [MPA] 51%, valganciclovir 25%, trimethoprim/sulfamethoxazole 19%). Steroids were added/increased as replacement for reduced/discontinued MPA. Granulocyte colony-stimulating factor was only used in 2/357 neutropenia episodes (0.6%). One-year incidence of (sub)clinical rejection, one-year mortality, and long-term patient and graft survival were not different among patients without neutropenia and neutropenia grade 2/3/4. However, the incidence of infections was about 3-times higher during neutropenia grade 3 and 4, but not increased during grade 2. In conclusion, neutropenia within the first year after kidney transplantation represents no increased risk for rejection and has no negative impact on long-term patient and graft survival. Adding/increasing steroids as replacement for reduced/discontinued MPA might supplement management of neutropenia.  相似文献   
992.
Increasing numbers of elderly (≥65 years) patients are listed for kidney transplantation. This study compares the survival outcome between living (LDK), regularly allocated (ETKAS), and Eurotransplant Senior Program (ESP) donor kidneys in elderly recipients. This is a single-center retrospective cohort study of elderly kidney transplant recipients transplanted between 2005 and 2017. Primary outcome measures were nondeath-censored graft, death-censored graft, and patient survival. In total, 348 patients were transplanted, 109 recipients (31.3%) received an LDK, 100 (28.7%) an ETKAS, and 139 (40%) an ESP kidney. 62.5% were male, and median age was 68 years. LDK recipients had significantly better 5-year nondeath-censored graft survival compared with ETKAS and ESP (resp. 71.0% vs. 66.1% vs. 55.6%, = 0.047). Death-censored graft survival after 1 year was significantly better in LDK recipients (99.1%) (ETKAS 90.8%; ESP 87.7%, P < 0.001). After 5 years, the difference remained significant (P < 0.001) with little additional graft loss (97.7% vs. 88.1% vs. 85.6). There was no significant difference in patient survival after 5 years (71.7% vs. 67.4% vs 61.9%, P = 0.480). In elderly recipients, the patient survival benefits of an LDK are limited, but there is decreased death-censored graft loss for LDK recipients. Nevertheless, graft survival in ETKAS and ESP remains satisfactory.  相似文献   
993.
Background There is limited information about the clinical characteristics, treatment and outcome of maintenance hemodialysis patients with COVID-19. Moreover, regional differences are also conceivable since the extend and severity of outbreaks varied among countries.Methods In this retrospective, observational, single-center study, we analyzed the clinical course and outcomes of 37 maintenance hemodialysis patients (median age 64 years, 51% men) hospitalized with COVID-19 from 24 March to 22 May 2020 as confirmed by real-time PCR.Results The most common symptoms at admission were fatigue (51%), fever (43%), dyspnea (38%) and cough (35%). There were 59% mild/moderate patients and 41% severe/critical patients. Patients in the severe/critical group had a significantly higher atherosclerotic burden since diabetic kidney disease and vascular nephropathies were the most common primary kidney diseases and eighty percent of them had coronary heart disease. Also, Charlson comorbidity score was higher in this group. At admission chest X-ray, 46% had ground-glass abnormalities. Overall, 60% patients received hydroxychloroquine, 22% lopinavir–ritonavir, 11% tocilizumab, 24% systemic glucocorticoids, and 54% received prophylactic anticoagulation. Seven (19%) patients died during hospitalization and 30 were discharged. The main causes of death were cardiovascular (5 patients) and respiratory distress syndrome (2 patients). In Cox regression analysis, lower oxygen saturation, anemia and hypoalbuminemia at admission were associated with increased mortality.Conclusions In conclusion, we observed a high mortality rate among maintenance hemodialysis patients hospitalized for COVID-19. Anemia, lower serum albumin and lower basal oxygen saturation at admission were factors associated with poor prognosis.  相似文献   
994.
995.
BackgroundLeukopenia is a common complication after kidney transplantation. The etiology is multifactorial, with medication adverse effects and cytomegalovirus infection as main causes. Optimal strategies to prevent or treat posttransplant leukopenia remain unknown. We aimed to identify risk factors for leukopenia and to investigate the benefit of switching the immunosuppressive therapy to hydrocortisone as a continuous infusion.MethodsWe retrospectively evaluated all patients with leukopenia after kidney transplantation between 2007 and 2017 at our center relative to age- and sex-matched controls.ResultsLeukopenia was associated with the degree of rejection therapy before leukopenia, the immunosuppressive therapy before transplantation, and an induction therapy with rabbit antithymocyte globulin. Patients with leukopenia exhibited increased mortality, an increased incidence of bacterial and viral infections, and more acute rejections. Switching to hydrocortisone as a continuous infusion in patients with severe leukopenia decreased the duration of leukopenia and the incidence of subsequent viral infections, especially with cytomegalovirus.ConclusionLeukopenia is a risk factor for infectious complications and mortality, and it is associated with acute rejection. Switching immunosuppressive therapy to hydrocortisone as a continuous infusion is a safe approach to reduce the duration of leukopenia and the incidence of viral infections.  相似文献   
996.
997.
998.
999.
Notfall + Rettungsmedizin - Der plötzliche Brust- und der plötzliche Unterleibsschmerz gehören zu den häufigsten Gründen, die Patienten in die Notaufnahme führen. Das...  相似文献   
1000.
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