全文获取类型
收费全文 | 3110篇 |
免费 | 288篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 68篇 |
妇产科学 | 38篇 |
基础医学 | 347篇 |
口腔科学 | 73篇 |
临床医学 | 279篇 |
内科学 | 665篇 |
皮肤病学 | 39篇 |
神经病学 | 407篇 |
特种医学 | 91篇 |
外科学 | 584篇 |
综合类 | 52篇 |
一般理论 | 2篇 |
预防医学 | 245篇 |
眼科学 | 101篇 |
药学 | 142篇 |
中国医学 | 2篇 |
肿瘤学 | 223篇 |
出版年
2022年 | 19篇 |
2021年 | 58篇 |
2020年 | 27篇 |
2019年 | 64篇 |
2018年 | 64篇 |
2017年 | 43篇 |
2016年 | 48篇 |
2015年 | 73篇 |
2014年 | 74篇 |
2013年 | 103篇 |
2012年 | 128篇 |
2011年 | 152篇 |
2010年 | 75篇 |
2009年 | 74篇 |
2008年 | 133篇 |
2007年 | 147篇 |
2006年 | 133篇 |
2005年 | 143篇 |
2004年 | 146篇 |
2003年 | 112篇 |
2002年 | 124篇 |
2001年 | 87篇 |
2000年 | 104篇 |
1999年 | 98篇 |
1998年 | 48篇 |
1997年 | 43篇 |
1996年 | 43篇 |
1995年 | 24篇 |
1994年 | 42篇 |
1993年 | 35篇 |
1992年 | 71篇 |
1991年 | 99篇 |
1990年 | 79篇 |
1989年 | 62篇 |
1988年 | 47篇 |
1987年 | 48篇 |
1986年 | 47篇 |
1985年 | 48篇 |
1984年 | 28篇 |
1983年 | 32篇 |
1982年 | 31篇 |
1981年 | 22篇 |
1979年 | 31篇 |
1978年 | 23篇 |
1977年 | 18篇 |
1976年 | 20篇 |
1974年 | 30篇 |
1973年 | 24篇 |
1972年 | 18篇 |
1971年 | 18篇 |
排序方式: 共有3406条查询结果,搜索用时 23 毫秒
1.
2.
器官移植术是20世纪出现的针对器官功能衰竭的最有效治疗方法,每年拯救全球超过12万例患者。但供器官短缺的现状,与器官移植技术和辅助药物的发展不匹配,制约了器官移植事业的发展。我国自2015年起已成为全球器官捐献和移植大国之一,2017年公民逝世后器官捐献数量超过5 000例,占全球捐献总量的15%以上。黄洁夫教授总结的器官捐献与移植"中国模式"得到了世界卫生组织、国际移植界的高度重视和充分肯定。本文通过整理全球及各国的器官捐献与移植数据,剖析全球现状与发展趋势,进一步探索我国公民器官捐献的影响因素并提出针对性的应对策略,以期实现我国器官捐献和移植的"自给自足"。 相似文献
3.
4.
Body weight and comorbidity predict mortality in COPD patients treated with oxygen therapy. 总被引:1,自引:0,他引:1
The aim of this study was to investigate the association between clinical variables and all-cause and respiratory mortality in patients with chronic obstructive pulmonary disease (COPD) undergoing long-term oxygen therapy (LTOT). The authors retrospectively studied a historic cohort of 128 patients with COPD (126 males, mean age+/-SD 68.9+/-9.7 yrs, body mass index (BMI) 25.1+/-4.5 kg.m-2, and forced expiratory volume in one second 25.4+/-8.8% predicted), who were being treated with long-term oxygen therapy in a tertiary teaching hospital between 1992 and 1999. Comorbidity, assessed with the Charlson Index, was present in 38% of the patients. Vital status and cause of death were assessed through the population death registry. A total of 78 patients (61%) had died by the end of follow-up. Three-year survival was 55%. Death was due to respiratory causes in 77% of cases. On Cox analysis, BMI<25 kg.m-2, comorbid conditions, age>or=70 yrs and cor pulmonale were associated with all-cause mortality. The BMI and comorbidity were the only significant predictive factors when the analysis was restricted to respiratory mortality. In conclusion, body mass index<25 kg.m-2 and comorbidity were predictors of all-cause and respiratory mortality in a cohort of chronic obstructive pulmonary disease patients treated with long-term oxygen therapy. These factors should be taken into account when considering the management and prognosis of these patients. 相似文献
5.
C Niek van Dijk Ben Willem J. Mol Liesbeth S. L. Lim Rene K. Marti Patrick M. M. Bossuyt 《Acta orthopaedica》1996,67(6):566-570
We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on. 122 of these patients had ligament ruptures.
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.
Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information. 相似文献
6.
Calcitonin gene-related peptide: functional role in cerebrovascular regulation. 总被引:14,自引:1,他引:13
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J McCulloch R Uddman T A Kingman L Edvinsson 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(15):5731-5735
Distribution studies disclosed that all major cerebral arteries and cortical arterioles of the cat were invested with fine varicose nerve fibers that contained calcitonin gene-related peptide (CGRP)-like immunoreactivity; the trigeminal ganglia likewise contained CGRP immunoreactivity. Sequential immunostaining with antibodies to CGRP and to substance P (SP) revealed identical distributions of these two peptides in trigeminal ganglia and cerebrovascular nerve fibers, suggesting that CGRP and SP are colocalized in these nerves. CGRP completely disappeared from ipsilateral blood vessels after unilateral section of the trigeminal nerve. Exogenous CGRP was a potent relaxant of feline middle cerebral arteries in vitro (maximum relaxation, 10.5 +/- 1.5 mN; concentration eliciting half-maximal response, 9.6 +/- 1.3 nM). Perivascular microapplication of CGRP to individual cortical arterioles of chloralose-anesthetized cats provoked dose-dependent dilatations (maximum increase in diameter, 38 +/- 5%; concentration eliciting half-maximal response, approximately equal to 3 nM). CGRP was significantly more potent than SP as a cerebrovascular dilator, both in vitro and in situ. Chronic division of the ipsilateral trigeminal nerve in cats did not modify the magnitude of arteriolar responses to perivascular microapplication of either vasoconstrictor or vasodilator agents, but the duration of vasoconstrictor responses to norepinephrine (0.1 mM) or alkaline solutions (pH 7.6) was significantly increased. The cerebrovascular trigeminal neuronal system, in which CGRP is the most potent vasoactive constituent, may participate in a reflex or local response to excessive cerebral vasoconstriction that restores normal vascular diameter. 相似文献
7.
In a large sample of joggers, endurance capacity was inversely, but weekly mileage, competitive training motive, and female gender were positively and independently related to use of ambulatory care. Despite the significance of regression models, sports activity and psychological characteristics of the joggers explained only a modest part of their low overall physician visit rates. 相似文献
8.
9.
10.
Nonprogression of subclinical beta-cell dysfunction among first-degree relatives of IDDM patients. 5-yr follow-up of the Seattle Family Study 总被引:4,自引:0,他引:4
D K McCulloch L J Klaff S E Kahn S L Schoenfeld C J Greenbaum R S Mauseth E A Benson G T Nepom L Shewey J P Palmer 《Diabetes》1990,39(5):549-556
It is unknown among first-degree relatives of individuals with insulin-dependent diabetes mellitus (IDDM) whether the disease process occurs in relatively few but always progresses to clinical IDDM or whether subclinical disease is more common but remains nonprogressive in many cases. Islet cell antibodies (ICAs) were found in 21 of 724 (2.9%) first-degree relatives during screening in the greater Seattle area between 1983 and 1988. Measures of beta-cell function (glucose disappearance rate [Kg], fasting insulin, acute insulin response to intravenous arginine [AIRarg], acute insulin response to intravenous glucose [AIRgluc], slope of glucose potentiation of AIRarg) and insulin sensitivity were obtained. Twenty individuals, 9 ICA+ relatives and 11 ICA- relatives, were evaluated prospectively. When expressed in relation to the expected AIRgluc based on each subject's sensitivity index, AIRgluc in 18 of 20 relatives fell below 100%, indicating inappropriately low insulin secretion (subclinical beta-cell dysfunction). After a median follow-up of 42 mo, 10 of 11 ICA- relatives remained ICA-. None showed deteriorating beta-cell dysfunction, and none developed diabetes. Five ICA+ relatives showed persistent immunologic positivity. beta-Cell function remained remarkably stable in all except 2 relatives. One was a 15-yr-old boy who developed IDDM shortly after screening and before evaluation of beta-cell function could be carried out. The other was an 18-yr-old monozygotic twin who developed IDDM after 27 mo. Both of these individuals had ICAs of 80 Juvenile Diabetes Foundation U and had been discordant for less than 5 yr.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献