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   1352569篇
  免费   98676篇
  国内免费   4463篇
耳鼻咽喉   19901篇
儿科学   40432篇
妇产科学   38847篇
基础医学   189012篇
口腔科学   40208篇
临床医学   114953篇
内科学   264367篇
皮肤病学   30390篇
神经病学   107105篇
特种医学   54360篇
外国民族医学   445篇
外科学   209856篇
综合类   35734篇
现状与发展   13篇
一般理论   436篇
预防医学   93733篇
眼科学   31928篇
药学   102301篇
  21篇
中国医学   4783篇
肿瘤学   76883篇
  2018年   12458篇
  2016年   11247篇
  2015年   12853篇
  2014年   17923篇
  2013年   26388篇
  2012年   34550篇
  2011年   36536篇
  2010年   21911篇
  2009年   21167篇
  2008年   34710篇
  2007年   37681篇
  2006年   38239篇
  2005年   36805篇
  2004年   35759篇
  2003年   34871篇
  2002年   34283篇
  2001年   64148篇
  2000年   65716篇
  1999年   55637篇
  1998年   14787篇
  1997年   13615篇
  1996年   13054篇
  1995年   12326篇
  1994年   11559篇
  1992年   42814篇
  1991年   41330篇
  1990年   40581篇
  1989年   39582篇
  1988年   36985篇
  1987年   36429篇
  1986年   34920篇
  1985年   33114篇
  1984年   24828篇
  1983年   21055篇
  1982年   12667篇
  1981年   11574篇
  1979年   23925篇
  1978年   17068篇
  1977年   14834篇
  1976年   13386篇
  1975年   15267篇
  1974年   18080篇
  1973年   17560篇
  1972年   16810篇
  1971年   15717篇
  1970年   14914篇
  1969年   14346篇
  1968年   13460篇
  1967年   11990篇
  1966年   11241篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
2.
目的 鉴定当地民间应用普遍的野生药用真菌,并探讨其治疗肿瘤的作用机制。方法 采用形态学和分子生物学方法对一株采自定陶仿山野生药用真菌进行鉴定,确定为硬皮马勃。通过文献检索收集硬皮马勃化学成分,利用PubChem软件和TCMSP、GCS数据库得到化学成分结构信息及其药用动力学参数和相关靶点分析,通过SysDT和WES系统鉴定潜在化学成分靶点,利用CTD数据库获得靶点功能,将潜在化合物和肿瘤相关靶点导入Cytoscape3.8.0软件构建分子-靶标网络。应用DAVID数据库对肿瘤相关靶点进行GO和KEGG富集分析,揭示有关活性成分靶点所涉及的生物学过程和通路,将肿瘤相关靶点和通路导入Cytoscape3.8.0软件构建靶点-通路网络。结果 从文献中获得硬皮马勃的化学成分59个,通过ADME计算系统筛选出5个潜在活性的化合物即活性成分,预测到38个靶点,其中与肿瘤相关靶点16个。这些活性成分主要通过Toll-like receptor、PI3K-AKT、MAPK和NF-kappa B等通路参与免疫应答,抑制肿瘤细胞生长、增殖,促进其凋亡。结论 表明硬皮马勃治疗肿瘤具有多靶点、多途径协同作用的特点,并通过多层次效应达到治疗肿瘤的效果。本研究为更好理解硬皮马勃作用肿瘤的机制和肿瘤药物开发提供理论依据。  相似文献   
3.

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017–6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21lo/neg cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21lo/neg B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21lo/neg cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21lo/neg B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.

  相似文献   
4.
Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster...  相似文献   
5.
6.
BackgroundTotal hip and knee arthroplasties are increasingly performed operations, and routine follow-up places huge demands on orthopedic services. This study investigates the effectiveness, patients’ satisfaction, and cost reduction of Virtual Joint Replacement Clinic (VJRC) follow-up of total hip arthroplasty and total knee arthroplasty patients in a university hospital. VJRC is especially valuable when in-person appointments are not advised or feasible such as during the COVID-19 pandemic.MethodsA total of 1749 patients who were invited for VJRC follow-up for knee or hip arthroplasty from January 2017 to December 2018 were included in this retrospective study. Patients were referred to VJRC after their 6-week postoperative review. Routine VJRC postoperative review was undertaken at 1 and 7 years and then 3-yearly thereafter. We evaluated the VJRC patient response rate, acceptability, and outcome. Patient satisfaction was measured in a subgroup of patients using a satisfaction survey. VJRC costs were calculated compared to face-to-face follow-up.ResultsThe VJRC had a 92.05% overall response rate. Only 7.22% required further in-person appointments with only 3% being reviewed by an orthopedic consultant. VJRC resulted in an estimated saving of £42,644 per year at our institution. The patients’ satisfaction survey showed that 89.29% of the patients were either satisfied or very satisfied with VJRC follow-up.ConclusionVJRC follow-up for hip and knee arthroplasty patients is an effective alternative to in-person clinic assessment which is accepted by patients, has high patient satisfaction, and can reduce the cost to both health services and patients.  相似文献   
7.
8.
9.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion.  相似文献   
10.
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