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   11762篇
  免费   777篇
  国内免费   273篇
耳鼻咽喉   134篇
儿科学   290篇
妇产科学   245篇
基础医学   703篇
口腔科学   242篇
临床医学   1744篇
内科学   1976篇
皮肤病学   159篇
神经病学   1140篇
特种医学   1047篇
外科学   1440篇
综合类   1278篇
现状与发展   1篇
预防医学   896篇
眼科学   154篇
药学   656篇
  3篇
中国医学   177篇
肿瘤学   527篇
  2023年   238篇
  2022年   421篇
  2021年   641篇
  2020年   566篇
  2019年   595篇
  2018年   664篇
  2017年   487篇
  2016年   477篇
  2015年   463篇
  2014年   951篇
  2013年   832篇
  2012年   633篇
  2011年   753篇
  2010年   519篇
  2009年   564篇
  2008年   558篇
  2007年   513篇
  2006年   421篇
  2005年   328篇
  2004年   304篇
  2003年   235篇
  2002年   210篇
  2001年   147篇
  2000年   125篇
  1999年   130篇
  1998年   92篇
  1997年   75篇
  1996年   72篇
  1995年   70篇
  1994年   79篇
  1993年   58篇
  1992年   46篇
  1991年   43篇
  1990年   36篇
  1989年   20篇
  1988年   33篇
  1987年   29篇
  1986年   21篇
  1985年   58篇
  1984年   55篇
  1983年   23篇
  1982年   37篇
  1981年   40篇
  1980年   29篇
  1979年   17篇
  1978年   27篇
  1977年   11篇
  1976年   22篇
  1975年   12篇
  1974年   12篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
【目的】 在“中国科技期刊卓越行动计划”实施三周年之际,有必要对我国科技期刊2035年迈入“世界第一方阵”目标的具体任务进行重新审视和预判,以进一步明确发展方向,动态调整推进思路。【方法】 采用国内外科技期刊、科技论文、科技期刊评价成果的系统性发展数据对科技期刊“世界第一方阵” 国家(或地区)在高水平科技期刊数量与质量层面的入围标准进行界定,在深入总结现有基础和优势的同时,对我国科技期刊综合实力与“世界第一方阵”国家(或地区)的现实差距进行逐一梳理和剖析,并对实现目标的可行性和推进思路进行研判和设计。【结果】 必须继续加强高水平英文科技期刊创办和培育力度、持续加大优秀中文科技期刊的建设强度、快速推进国内外科技期刊论文等质同效评价制度的建设与引导,并积极探索建立科学家和科研机构办好一流科技期刊的责任制度和贡献激励机制、创新发展编辑人才队伍培养与激励管理思路、深入实践灵活多样的期刊出版市场资本运作模式、稳步推进期刊出版市场机制和管理制度改革,为我国科技期刊事业的高质量发展提速增效。【结论】 虽然当前阶段目标任务艰巨,但迈入“世界第一方阵”未来可期。  相似文献   
3.
BackgroundThis study aimed to investigate which gastric cancer patients could benefit the most from staging laparoscopy.MethodsA retrospective cohort study was carried out, including 316 (216 cM- and 100 cM+) gastric cancer patients who had undergone staging laparoscopy between 2010 and 2020 in seven GIRCG centers. A model including easily-accessible clinical, biochemical and pathological markers was constructed to predict the risk of carcinomatosis. ROC curve and decision curve analyses were used to verify its accuracy and net benefit.ResultsIn the cM-population staging laparoscopy could detect 67 cases who had peritoneal carcinomatosis or positive cytology, for a yield of 30.5%. In cM-patients, intestinal type tumors (0.25, 0.12–0.51; p = 0.002), cT4 tumors (2.18, 1.11–4.28; p = 0.023) and cancers of the lower third (0.31, 0.14–0.70; p = 0.004) were associated with the presence of peritoneal carcinomatosis and/or positive cytology. The ROC curve analysis of the model including the three variables showed an AUC of 0.75 (0.68–0.81, p < 0.001). The decision curve analyses showed that the model had a higher net benefit than the treating all strategy between threshold probabilities of 15 and 50%.ConclusionsStaging laparoscopy is a useful tool to address the patient with gastric cancer to the most adequate treatment. In cM-patients the assessment of the location of the tumor, the Lauren's histotype and the cT status may help in providing additional elements in indicating or not the use of staging laparoscopy.  相似文献   
4.
Aim of the studyOur study aimed to identify the characteristics of cardiac involvement in eosinophilic granulomatosis with polyangiitis (EGPA).MethodsWe conducted a retrospective analytic study including EGPA cases diagnosed between 2000 and 2019 in an internal medicine department. Diagnosis was made according to the 1990 American College of Rheumatology criteria and the 2012 Chapel Hill Concensus.ResultsEleven EGPA cases were included, 64% of patients were female. Median age at diagnosis was 52 years [42–58]. Heart damage revealed EGPA in 55% of cases with a significant predominance of women (p = 0.015). The main cardiac manifestations were myocarditis, ischemic cardiomyopathy due to small vessel vasculitis, cardiac tamponade and intracardiac thrombus. Cardiac magnetic resonance imaging (MRI) mainly showed subendocardial hyposignal in early infusion and late enhancement in the same areas, nodular by locations, associated with impaired left ventricle function and micro-infarctions by distal vasculitis. Cardiac damage was associated to ANCA negativity in 83.3% of cases. The median Birmingham Vasculitis Activity Score version3 (BVAS v3) was 16 [10–17]. Under conventional treatment, no relapses had occurred. The median vasculitis damage index (VDI) was 2 [1–2.3] and the mortality rate was zero after a mean follow-up of 43 months.ConclusionCardiomyopathy is a frequent revealing mode of EGPA. A late onset asthma and hypereosinophilia should guide the diagnosis. As ANCA research often turns out to be negative, histological evidence is recommended in this context. The contribution of cardiac MRI in the diagnosis of EGPA remains to be defined.  相似文献   
5.
The adrenal cortex gives rise to a biologically heterogenous group of neoplasms, each with a distinct morphology, antigen expression and molecular profile. Adrenal cortical adenomas have excellent prognosis and are usually cured by surgical resection alone, while adrenal cortical carcinomas are very aggressive tumors with a poor prognosis regardless of therapy. These tumors are rare and often challenging for a pathologist to diagnose, as significant overlap exists between benign and malignant lesions in some cases. In this review, we attempt to summarize most important histologic and clinical features of adrenal cortical adenomas and carcinomas, clarify the use of different grading systems, the use of special stains and the differential diagnosis for practicing pathologists. Most relevant hereditary syndromes associated with adrenal cortical tumors are listed. Updates in molecular alterations in adrenal cortical neoplasms and hyperplastic diseases as well as their clinical significance and potential therapeutic implications are also discussed.  相似文献   
6.
7.
8.
9.

Background

Early interdisciplinary rehabilitation (EIR) in neurointensive care is a limited resource reserved for patients with moderate to severe traumatic brain injury (TBI) believed to profit from treatment. We evaluated how key parameters related to injury severity and patient characteristics were predictive of receiving EIR, and whether these parameters changed over time.

Methods

Among 1003 adult patients with moderate to severe TBI admitted over 72 h to neurointensive care unit during four time periods between 2005 and 2020, EIR was given to 578 and standard care to 425 patients. Ten selection criteria thought to best represent injury severity and patient benefit were evaluated (Glasgow Coma Scale, Head Abbreviated Injury Scale, New-Injury-Severity-Scale, intracranial pressure monitoring, neurosurgery, age, employment, Charlson Comorbidity Index, severe psychiatric disease, and chronic substance abuse).

Results

In multivariate regression analysis, patients who were employed (adjOR 1.99 [95% CI 1.41, 2.80]), had no/mild comorbidity (adjOR 3.15 [95% CI 1.72, 5.79]), needed neurosurgery, had increasing injury severity and were admitted by increasing time period were more likely to receive EIR, whereas receiving EIR was less likely with increasing age (adjOR 0.97 [95% CI 0.96, 0.98]) and chronic substance abuse. Overall predictive ability of the model was 71%. Median age and comorbidity increased while employment decreased from 2005 to 2020, indicating patient selection became less restrictive with time.

Conclusion

Injury severity and need for neurosurgery remain important predictors for receiving EIR, but the importance of age, employment, and comorbidity have changed over time. Moderate prediction accuracy using current clinical criteria suggest unrecognized factors are important for patient selection.  相似文献   
10.
It is unclear which criteria should be used to define readiness for tracheal extubation in the operating theatre. We studied the effects of desaturation in the operating theatre immediately after tracheal extubation on long-term outcomes. Performing a pre-specified, retrospective analysis of 71,025 cases involving previously independent adults undergoing non-cardiac surgery, we evaluated the association between desaturation events (oxygen saturation < 90%) within 10 min of tracheal extubation and adverse discharge (to a skilled nursing facility or long-term care facility). A total of 404 (12.3%) cases with, and 5035 (7.4%) cases without, early postoperative desaturation had an adverse discharge. Early postoperative desaturation was associated with higher odds of being discharged to a nursing facility (adjusted odds ratio 1.36 (95%CI 1.20–1.54); p < 0.001). Increased duration of desaturation augmented the effect (p for trend < 0.001). Desaturation was associated with a higher risk of respiratory, renal and cardiovascular complications as well as increased duration of hospital stay, postoperative intensive care unit admission frequency and cost. Several modifiable factors were associated with desaturation including: high intra-operative long-acting opioid administration; high neostigmine dose; high intra-operative inspired oxygen concentration; and low oxygen delivery immediately before tracheal extubation. There was substantial provider variability between anaesthetists in the incidence of postoperative desaturation unexplained by patient- and procedure-related factors. Early postoperative desaturation is a potentially preventable complication associated with a higher risk of adverse discharge disposition. Anaesthetists may consider developing guidelines to define tracheal extubation readiness that contain postoperative desaturation as an adverse outcome after tracheal extubation.  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