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   39952篇
  免费   4126篇
  国内免费   963篇
耳鼻咽喉   252篇
儿科学   1012篇
妇产科学   450篇
基础医学   1815篇
口腔科学   1060篇
临床医学   5787篇
内科学   3814篇
皮肤病学   251篇
神经病学   2290篇
特种医学   776篇
外国民族医学   7篇
外科学   2519篇
综合类   5262篇
现状与发展   2篇
一般理论   1篇
预防医学   10989篇
眼科学   204篇
药学   4195篇
  105篇
中国医学   2468篇
肿瘤学   1782篇
  2024年   94篇
  2023年   939篇
  2022年   1323篇
  2021年   1996篇
  2020年   2080篇
  2019年   1740篇
  2018年   1616篇
  2017年   1692篇
  2016年   1695篇
  2015年   1605篇
  2014年   3005篇
  2013年   3351篇
  2012年   2669篇
  2011年   2828篇
  2010年   2146篇
  2009年   2105篇
  2008年   2034篇
  2007年   1912篇
  2006年   1560篇
  2005年   1248篇
  2004年   1075篇
  2003年   922篇
  2002年   719篇
  2001年   629篇
  2000年   543篇
  1999年   475篇
  1998年   377篇
  1997年   311篇
  1996年   265篇
  1995年   274篇
  1994年   237篇
  1993年   191篇
  1992年   192篇
  1991年   155篇
  1990年   135篇
  1989年   123篇
  1988年   117篇
  1987年   78篇
  1986年   78篇
  1985年   112篇
  1984年   86篇
  1983年   53篇
  1982年   49篇
  1981年   41篇
  1980年   43篇
  1979年   24篇
  1978年   30篇
  1977年   19篇
  1976年   13篇
  1975年   13篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Chronic Hepatitis B is a highly prevalent disease worldwide and is estimated to cause more than 800000 annual deaths from complications such as cirrhosis and hepatocellular carcinoma (HCC). Although universal hepatitis B vaccination programs may have reduced the incidence and prevalence of chronic hepatitis B and related HCC, the disease still imposes a significant healthcare burden in many endemic regions such as Africa and the Asia-Pacific region. This is especially concerning given the global underdiagnosis of hepatitis B and the limited availability of vaccination, screening, and treatment in low-resource regions. Demographics including male gender, older age, ethnicity, and geographic location as well as low socioeconomic status are more heavily impacted by chronic hepatitis B and related HCC. Methods to mitigate this impact include increasing screening in high-risk groups according to national guidelines, increasing awareness and health literacy in vulnerable populations, and developing more robust vaccination programs in under-served regions.  相似文献   
2.
Interventions that involve key aspects of community organizing, such as quantitative community assessments and organizational partnership support for the community, may promote residents' health. We evaluated the effectiveness of this form of intervention on mortality and its variability across individual-level household equivalized income tertiles, comparing 52,858 residents aged 65 and above in 12 intervention municipalities to 39,006 residents in nine control municipalities in Japan. During 1,166 days of follow-up, the adjusted hazard ratio for cumulative mortality among men in the intervention municipalities was 0.92 (95% confidence interval: 0.86, 0.99) compared to those in the control group, with similar results being observed across all income levels. Active utilization of data to evaluate communities and building intersectoral partnerships might lower older male residents’ mortality risk, regardless of their income status.  相似文献   
3.
4.
5.
《Molecular therapy》2022,30(8):2856-2867
  1. Download : Download high-res image (173KB)
  2. Download : Download full-size image
  相似文献   
6.
《Pancreatology》2022,22(2):270-276
Backgroundand purpose: Zinc is an essential element for human health and plays an important role in metabolic, immunological and other biological processes. The present study was conducted to investigate the association between zinc deficiency (ZD) and the perioperative clinical course in patients with pancreatic ductal adenocarcinoma (PDAC).MethodsOf 216 patients with PDAC who underwent elective pancreatectomy between 2013 and 2017 at our institution, 206 patients with sufficient clinical data were retrospectively reviewed. The perioperative variables were compared and the risk factors associated with infectious complications were identified.ResultsZD was preoperatively present in 36 (17.5%) of 206 patients with PDAC. In the patients of the ZD group, a higher proportion of males, higher preoperative modified Glasgow prognostic scores, a higher neutrophil-to-lymphocyte ratio, and a higher occurrence of postoperative infectious complications after pancreatectomy were observed, compared to the non-ZD group. By a univariate analysis, three risk factors were significantly associated with infectious complications after pancreatectomy: ZD (vs non-ZD: p = 0.002), serum albumin <3.5 g/dl (vs ≥ 3.5 g/dl: p = 0.005), and the procedure of pancreaticoduodenectomy (vs others: p = 0.013). By multivariate logistic regression analysis, the occurrence of infectious complications was significantly associated with ZD (OR 3.430, 95%CI 1.570 to 7.490, p = 0.002) and the procedure of pancreaticoduodenectomy (OR 2.030, 95%CI 1.090 to 3.770, p = 0.025).ConclusionsThe current study newly demonstrated that ZD could serve as a preoperative predictor of infectious complications after pancreatectomies in the patients with PDAC.  相似文献   
7.
8.
9.
《Value in health》2022,25(6):1018-1029
ObjectivesThis study aimed to explore quality-adjusted life-year (QALY) and subsequent cost-effectiveness estimates based on the more physical health–focused EQ-5D 5-level version (EQ-5D-5L) value set for England or cross-walked EQ-5D 3-level version UK value set scores or more mental health recovery-focused Recovering Quality of Life Utility Index (ReQoL-UI), when using alternative within-trial statistical methods. We describe possible reasons for the different QALY estimates based on the interaction between item scores, health state profiles, preference-based scores, and mathematical and statistical methods chosen.MethodsQALYs are calculated over 8 weeks from a case study 2:1 (intervention:control) randomized controlled trial in patients with anxiety or depression. Complete case and with missing cases imputed using multiple-imputation analyses are conducted, using unadjusted and regression baseline-adjusted QALYs. Cost-effectiveness is judged using incremental cost-effectiveness ratios and acceptability curves. We use previously established psychometric results to reflect on estimated QALYs.ResultsA total of 361 people (241:120) were randomized. EQ-5D-5L crosswalk produced higher incremental QALYs than the value set for England or ReQoL-UI, which produced similar unadjusted QALYs, but contrasting baseline-adjusted QALYs. Probability of cost-effectiveness <£30 000 per QALY ranged from 6% (complete case ReQoL-UI baseline-adjusted QALYs) to 64.3% (multiple-imputation EQ-5D-5L crosswalk unadjusted QALYs). The control arm improved more on average than the intervention arm on the ReQoL-UI, a result not mirrored on the EQ-5D-5L nor condition-specific (Patient-Health Questionnaire-9, depression; Generalized Anxiety Disorder-7, anxiety) measures.ConclusionsReQoL-UI produced contradictory cost-effectiveness results relative to the EQ-5D-5L. The EQ-5D-5L’s better responsiveness and “anxiety/depression” and “usual activities” items drove the incremental QALY results. The ReQoL-UI’s single physical health item and “personal recovery” construct may have influenced its lower 8-week incremental QALY estimates in this patient sample.  相似文献   
10.
目的 本实验采用HPLC方法建立来自3个产地15批怀牛膝药材的指纹图谱,并对β-蜕皮甾酮,25R-牛膝甾酮,25S-牛膝甾酮进行含量测定,同时通过化学计量学的方法对15批怀牛膝进行质量评价。方法 选用Waters SunFire C18(150 mm×4.6 mm,5 μm)色谱柱,检测波长280 nm,以乙腈-0.1%甲酸水梯度洗脱,流速为1.0 mL·min-1,柱温25℃,进样量10 μL。以β-蜕皮甾酮峰为参照峰,运用软件《中药色谱指纹图谱相似度评价系统(2012版)》对15批怀牛膝药材进行相似度分析,使用Metabo Analyst 5.0网站进行聚类热图分析,使用SIMCA 14.1软件进行PCA和PLS-DA分析。结果 标定了31个共有指纹峰,指认了3个已知成分,并对其进行含量测定,化学计量学分析结果将15批怀牛膝药材样品分为3类,并且筛选了不同产地间潜在的差异性成分。结论 该方法具有良好的精密度、重复性以及稳定性,可为怀牛膝的质量评价与控制提供科学依据及参考。  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