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   2995862篇
  免费   236675篇
  国内免费   5171篇
耳鼻咽喉   43513篇
儿科学   89189篇
妇产科学   78670篇
基础医学   422904篇
口腔科学   88158篇
临床医学   270744篇
内科学   584785篇
皮肤病学   61422篇
神经病学   247377篇
特种医学   119207篇
外国民族医学   941篇
外科学   461818篇
综合类   68316篇
现状与发展   2篇
一般理论   1156篇
预防医学   232863篇
眼科学   70708篇
药学   227671篇
  7篇
中国医学   5883篇
肿瘤学   162374篇
  2018年   29832篇
  2016年   25547篇
  2015年   28946篇
  2014年   41254篇
  2013年   62399篇
  2012年   84348篇
  2011年   88937篇
  2010年   52454篇
  2009年   50225篇
  2008年   85089篇
  2007年   90171篇
  2006年   91529篇
  2005年   89092篇
  2004年   85870篇
  2003年   82776篇
  2002年   81681篇
  2001年   145862篇
  2000年   151109篇
  1999年   127588篇
  1998年   34967篇
  1997年   31559篇
  1996年   31381篇
  1995年   30184篇
  1994年   28337篇
  1993年   26317篇
  1992年   101956篇
  1991年   98371篇
  1990年   95019篇
  1989年   91960篇
  1988年   85006篇
  1987年   83393篇
  1986年   78833篇
  1985年   75383篇
  1984年   56247篇
  1983年   47970篇
  1982年   28009篇
  1981年   24834篇
  1980年   23208篇
  1979年   52158篇
  1978年   36259篇
  1977年   30771篇
  1976年   28318篇
  1975年   30249篇
  1974年   37211篇
  1973年   35293篇
  1972年   33190篇
  1971年   30874篇
  1970年   29087篇
  1969年   27224篇
  1968年   24713篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia.  相似文献   
33.
34.
35.
36.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
37.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
38.
Aims: In neuropsychological evaluations, it is often difficult to ascertain whether poor performance on measures of validity is due to poor effort or malingering, or whether there is genuine cognitive impairment. Dunham and Denney created an algorithm to assess this question using the Medical Symptom Validity Test (MSVT). We assessed the ability of their algorithm to detect poor validity versus probable impairment, and concordance of failure on the MSVT with other freestanding tests of performance validity.

Methods: Two previously published datasets (n?=?153 and n?=?641, respectively) from outpatient neuropsychological evaluations were used to test Dunham and Denney’s algorithm, and to assess concordance of failure rates with the Test of Memory Malingering and the forced choice measure of the California Verbal Learning Test, two commonly used performance validity tests.

Results: In both datasets, none of the four cutoff scores for failure on the MSVT (70%, 75%, 80%, or 85%) identified a poor validity group with proportionally aligned failure rates on other freestanding measures of performance validity. Additionally, the protocols with probable impairment did not differ from those with poor validity on cognitive measures.

Conclusions: Despite what appeared to be a promising approach to evaluating failure on the easy MSVT subtests when clinical data are unavailable (as recommended in the advanced interpretation program, or advanced interpretation [AI], of the MSVT), the current findings indicate the AI remains the gold standard for doing so. Future research should build on this effort to address shortcomings in measures of effort in neuropsychological evaluations.  相似文献   

39.
Gattermann  J. 《Der Onkologe》2020,26(11):1010-1018
Die Onkologie - Die Corona-Pandemie hat in den letzten Monaten verdeutlicht, dass das Thema Sterblichkeit trotz erheblicher Fortschritte im Bereich der Hospiz- und Palliativversorgung zu...  相似文献   
40.
Objective: Human epidermal growth factor receptor 2 (erbb2/HER2) overexpression, has now been implicatedin advanced gastric and gastroesophageal junction cancers. The study was conducted to determine the rate of HER2positivity in patients with locally advanced or metastatic gastric and gastroesophageal adenocarcinoma in North-EastIndia and to assess the impact of various demographic and clinical parameters on HER2 positivity. Methods: A total of68 patients of age >18 years of gastric and gastroesophageal adenocarcinoma diagnosed on histopathological examinationfrom September 2016 to February 2018 at Dr B Borooah Cancer Institute, Assam were enrolled for the observational(epidemiological) study. All patients were subjected to the HER2 immunohistochemistry test using a FDA-approved,standardized test kit. HER2 expression was correlated with various demographic and clinicopathological parameters.Results: The overall rate of HER2 positivity in the population studied was 56% (n=38). The rate was non-significantlyhigher in male, older age group (>60 years) and Hindu population. Similarly, HER2 positivity rate was higher in patientswith well differentiated histology and was more common in patients with stage II and III diseases, but neither of theassociations is statistically significant. HER2 positivity rate was significantly higher in proximal and in GEJ tumours(56% versus 44%, P=0.002). Conclusion: HER2 overexpression was evident in 56% of the North-East Indian patientswith locally advanced and metastatic gastric and gastroesophageal adenocarcinoma. The overexpression correlatedsignificantly with primary tumour site. Routine testing of gastric and gastroesophageal tumours for HER2 expressionis recommended to provide a therapeutic advantage in Indian patients.  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