全文获取类型
收费全文 | 113303篇 |
免费 | 10967篇 |
国内免费 | 5160篇 |
专业分类
耳鼻咽喉 | 320篇 |
儿科学 | 2248篇 |
妇产科学 | 605篇 |
基础医学 | 8565篇 |
口腔科学 | 648篇 |
临床医学 | 14009篇 |
内科学 | 12822篇 |
皮肤病学 | 356篇 |
神经病学 | 7495篇 |
特种医学 | 6342篇 |
外国民族医学 | 97篇 |
外科学 | 17296篇 |
综合类 | 21836篇 |
现状与发展 | 13篇 |
一般理论 | 1篇 |
预防医学 | 5454篇 |
眼科学 | 924篇 |
药学 | 10152篇 |
73篇 | |
中国医学 | 5441篇 |
肿瘤学 | 14733篇 |
出版年
2024年 | 354篇 |
2023年 | 1974篇 |
2022年 | 3618篇 |
2021年 | 5518篇 |
2020年 | 4939篇 |
2019年 | 3975篇 |
2018年 | 3932篇 |
2017年 | 4572篇 |
2016年 | 4854篇 |
2015年 | 4809篇 |
2014年 | 7718篇 |
2013年 | 8524篇 |
2012年 | 7127篇 |
2011年 | 7700篇 |
2010年 | 6310篇 |
2009年 | 5896篇 |
2008年 | 5805篇 |
2007年 | 5947篇 |
2006年 | 5502篇 |
2005年 | 4834篇 |
2004年 | 3825篇 |
2003年 | 3340篇 |
2002年 | 2760篇 |
2001年 | 2464篇 |
2000年 | 1991篇 |
1999年 | 1578篇 |
1998年 | 1369篇 |
1997年 | 1303篇 |
1996年 | 1077篇 |
1995年 | 874篇 |
1994年 | 746篇 |
1993年 | 578篇 |
1992年 | 555篇 |
1991年 | 432篇 |
1990年 | 391篇 |
1989年 | 330篇 |
1988年 | 282篇 |
1987年 | 256篇 |
1986年 | 225篇 |
1985年 | 232篇 |
1984年 | 167篇 |
1983年 | 116篇 |
1982年 | 127篇 |
1981年 | 118篇 |
1980年 | 116篇 |
1979年 | 77篇 |
1978年 | 47篇 |
1977年 | 44篇 |
1976年 | 33篇 |
1975年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
51.
52.
《Neurocirugía (Asturias, Spain)》2021,32(5):209-216
ObjectiveTo analyze the incidence and characteristics of traumatic spinal cord injury (SCI) in geriatric population of Galicia (Spain), hospital management and functional prognosis.MethodsComparative retrospective study. Patients admitted with acute traumatic SCI during the time period between January 2010 and December 2016 were included. Two groups established: The elderly over and under 75 years of age, with the latter acting as a control group.ResultsThree hundred seventy-nine patients were studied (27.2% ≥75 years). The main etiology in the >75 years group were falls: 80.6%. There were 65.7% who presented incomplete spinal cord injuries with mean motor index (MI) of 44.9/100. Upon discharge, 90.8% were dependent. Hospital mortality was 34.9%. Those >75 years suffered from more cervical injuries (74.8 vs. 51.2%; p<0.001), longer delay in diagnosis (31.1 vs. 9.2%; p<0.001) and higher hospital mortality (34.9 vs. 3.2%; p<0.001). Fewer surgical interventions were performed, with a longer delay. Percentages for admission into ICU, mechanical ventilation and performing a tracheostomy proved to be similar. There were no significant differences found in the evolution according to the ASIA scale or the MI.Conclusions1) The frequency of traumatic SCI in the elderly in Galicia is high; 2) Neurological evolution is similar to younger patients but the level of dependence is higher; 3) The level of care provided is similar in both groups, except for the surgical indication, and 4) Hospital mortality is high. 相似文献
53.
Elizabeth M. Broad Laura J. Newsome Dustin A. Dew 《The journal of spinal cord medicine》2020,43(3):388-397
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.Design: Cohort-based validation study.Setting. Paralympic team training camp.Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity. 相似文献
54.
冠状病毒(coronavirus,CoVs)感染主要累及肺部,但对心血管系统损伤作用也不容忽视。CoVs感染引起的心脏损伤并非罕见,其发生与病情的严重程度密切相关。本文首先从CoVs引起心血管损伤的证据入手,进一步探讨了CoVs对心肌的直接损伤,以及肾素血管紧张素(RAS)系统激活和细胞因子风暴与炎症反应对心血管损伤的可能作用机制。相关心血管损伤的可能机制包括,(1)病毒直接作用:CoVs在心肌细胞复制,损伤心肌;(2)RAS系统激活:感染CoVs后,心脏血管紧张素转化酶2(angiotensin-converting enzyme 2,ACE2)的表达下调,激活RAS系统,使得血管紧张素Ⅱ(AngiotensinⅡ,AngⅡ)收缩血管功能增强,Ang1-7保护心脏效应减弱;(3)诱发细胞因子风暴:循环细胞因子和全身炎症反应引起心脏损伤;(4)其他:包括低氧血症和儿茶酚胺心脏毒性。本文就相关内容作一综述,为后续的详尽机制和治疗策略研究提供思路。 相似文献
55.
Validity and reliability of the Turkish version of the pressure injury knowledge assessment tool 2.0
《Journal of tissue viability》2021,30(4):582-587
AimThe aim of this study was to develop a Turkish version of the Pressure Ulcer Knowledge Assessment Tool 2.0 (PUKAT 2.0) and determine its validity and reliability.Materials and MethodsThis was a cross-cultural adaptation and validation study. The study sample included a total of 451 participants (232 nurses and 219 nursing students). The validity of the Turkish version of the PUKAT 2.0 was evaluated with linguistic validity, content validity, item validity (item difficulty, discriminating index), and construct validity (known-groups technique) analyses. The reliability of the tool was evaluated by conducting a test–retest analysis.ResultsContent validity index (CVI) for the items (Item-CVI) ranged from 0.83 to 1.00 and the CVI for the scale (Scale-CVI) was 0.95. The difficulty index for 21 items ranged from 0.10 to 0.63. Four items were found to be too difficult. Item discriminating index values ranged from 0.00 to 0.61. The overall intraclass correlation coefficient (ICC) was found to be 0.80.ConclusionThe Turkish version of the Pressure Injury Knowledge Assessment Tool 2.0 (PIKAT 2.0-Tr) is supported by acceptable psychometric properties and can be used to evaluate the knowledge of nurses and nursing students in Turkey about the prevention of PI. 相似文献
56.
Margaret H. Lauerman Karen Irizarry Clint Sliker Brandon R. Bruns Ronald Tesoriero Thomas M. Scalea Deborah M. Stein 《Injury》2019,50(1):131-136
Background
Current blunt cerebrovascular injury (BCVI) grading grossly differentiates injury characteristics such as luminal stenosis (LS) and aneurysmal disease. The effect of increasing degree of LS beyond the current BCVI grading scale on stroke formation is unknown.Study Design
BCVI over a 3-year period were retrospectively reviewed. To investigate influence of LS beyond the BCVI grading scale within aneurysmal and non-aneurysmal BCVI, grade 2 BCVI were subdivided into BCVI with ≥ 25% and ≤ 50% LS and BCVI with > 50% and ≤ 99% LS. Grade 3 BCVI were subdivided into BCVI with pseudoaneurysm (PSA) without LS and BCVI with PSA and LS. We hypothesized increased LS beyond the current BCVI grade distinctions would be associated with higher rates of stroke formation.Results
312 BCVI were included, of which 140 were carotid BCVI and 172 vertebral BCVI. Sixteen carotid BCVI underwent endovascular intervention (EI) and 19 suffered a stroke. In carotid BCVI stroke rates increased sequentially with BCVI grade except in grade 3. There was a stroke rate of 12% in grade 1 carotid BCVI, 18% in grade 2, 6% in grade 3, and 31% in grade 4. In subgroup analysis for grade 2 carotid BCVI, BCVI with > 50% and ≤ 99% LS had higher rates of stroke (22% vs. 15%, p?=?0.44) than BCVI with ≥ 25% and ≤ 50% LS. In subgroup analysis of grade 3 carotid BCVI, BCVI with PSA and LS had higher rates of stroke (9% vs. 4%, p?=?0.48) than BCVI with PSA without LS. Higher rates of EI in grade 2 carotid BCVI with > 50% and ≤ 99% LS (22% vs. 5%, p?=?0.14) and grade 3 carotid BCVI with PSA and LS (35% vs. 4%, p?=?0.01) were noted in subgroup analysis.Conclusion
Higher percentage LS beyond the currently used BCVI grading scale has a non-significantly increased rate of stroke in both aneurysmal and non-aneurysmal BCVI. Grade 3 BCVI with PSA and LS seems to be a high-risk subgroup. Use of EI confounds modern measurement of stroke risk in higher LS BCVI. 相似文献57.
58.
59.
目的:研究乳腺癌细胞中转录调节因子c-Myb的表达对肺转移的影响及其分子机制。方法:构建c-Myb高表达的4T1乳腺癌细胞株,种植小鼠构建乳腺癌动物模型,检测实验动物肺转移情况,通过荷瘤抑制试验检测肺转移抑制效果。提取组织进行荧光PCR检测相关炎症因子的表达。利用Medisapiens数据库的生物信息学资源,对c-Myb和Ccl2的表达与乳腺癌患者的预后进行分析。结果:高表达c-Myb的荷瘤小鼠肺部转移灶明显减少,其中炎症相关因子表达受限。由数据库分析得出,c-Myb高表达患者生存期得以延长。结论:乳腺癌中c-Myb的表达能够通过炎症因子Ccl2抑制肺转移从而延长患者生存期。 相似文献
60.