全文获取类型
收费全文 | 55892篇 |
免费 | 5125篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 497篇 |
儿科学 | 1769篇 |
妇产科学 | 1307篇 |
基础医学 | 7475篇 |
口腔科学 | 1230篇 |
临床医学 | 6495篇 |
内科学 | 10203篇 |
皮肤病学 | 856篇 |
神经病学 | 5022篇 |
特种医学 | 2122篇 |
外国民族医学 | 3篇 |
外科学 | 7886篇 |
综合类 | 1056篇 |
一般理论 | 62篇 |
预防医学 | 6103篇 |
眼科学 | 1351篇 |
药学 | 4274篇 |
中国医学 | 63篇 |
肿瘤学 | 3330篇 |
出版年
2022年 | 435篇 |
2021年 | 1060篇 |
2020年 | 576篇 |
2019年 | 1033篇 |
2018年 | 1137篇 |
2017年 | 829篇 |
2016年 | 899篇 |
2015年 | 1007篇 |
2014年 | 1470篇 |
2013年 | 2100篇 |
2012年 | 3163篇 |
2011年 | 3096篇 |
2010年 | 1781篇 |
2009年 | 1612篇 |
2008年 | 2863篇 |
2007年 | 2962篇 |
2006年 | 2994篇 |
2005年 | 2900篇 |
2004年 | 2782篇 |
2003年 | 2497篇 |
2002年 | 2360篇 |
2001年 | 1425篇 |
2000年 | 1441篇 |
1999年 | 1285篇 |
1998年 | 666篇 |
1997年 | 561篇 |
1996年 | 514篇 |
1995年 | 442篇 |
1994年 | 470篇 |
1993年 | 447篇 |
1992年 | 953篇 |
1991年 | 926篇 |
1990年 | 902篇 |
1989年 | 792篇 |
1988年 | 830篇 |
1987年 | 769篇 |
1986年 | 704篇 |
1985年 | 763篇 |
1984年 | 651篇 |
1983年 | 522篇 |
1982年 | 360篇 |
1981年 | 382篇 |
1980年 | 334篇 |
1979年 | 542篇 |
1978年 | 422篇 |
1977年 | 315篇 |
1976年 | 313篇 |
1974年 | 334篇 |
1973年 | 325篇 |
1972年 | 319篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Increased production of peroxidation products associated with cardiac operations. Evidence for free radical generation 总被引:7,自引:0,他引:7
D Royston J S Fleming J B Desai S Westaby K M Taylor 《The Journal of thoracic and cardiovascular surgery》1986,91(5):759-766
We investigated the degree and time course of neutrophil sequestration into human lungs during cardiac operations. At the same time, measurement of the concentration of peroxidation products in the plasma was used as an index of oxidant free radical activity. The study was performed in two groups of patients. Group A (n = 11) had studies extending over the entire operative period and showed a highly significant sequestration of neutrophils into the lung, together with a highly significant (p less than 0.001) rise in peroxidation products from 2.8 +/- 0.12 nmol/ml(mean +/- standard error of the mean)before bypass to a peak of 5.05 +/- 0.13 nmol/ml at the end of bypass. As these changes occurred only during the time after release of the aortic cross-clamp, we investigated this period in more detail in a second group of patients (Group B, n = 7). Results from this group showed that significant release of peroxidation products occurred at the same time as pulmonary neutrophil sequestration. This study has produced evidence of increased oxidant activity in the lung associated with cardiac operations. Nevertheless, it is not known whether the neutrophils sequestered into the lung alone induced the increased activity. Similarly, whether neutrophil-derived oxidant species are the sole cause of lung tissue injury remains unproved. 相似文献
23.
PRIMARY LYMPHOSARCOMA OF THE STOMACH 总被引:3,自引:3,他引:0
Taylor ES 《Annals of surgery》1939,110(2):200-221
24.
25.
Introduction
Although ependymoma is the third most common pediatric brain tumor, we know little about the genetic/epigenetic basis of its initiation, maintenance, or progression. This is due in part to the heterogeneity of the disease, as well as the small sample size of the cohorts analyzed in most studies. 相似文献26.
NTS fallout-induced multiple myeloma in Utah. 总被引:1,自引:0,他引:1
27.
Predicting failure in polytetrafluoroethylene vascular access grafts for hemodialysis: a pilot study
C R Shackleton D C Taylor A R Buckley V A Rowley P L Cooperberg P D Fry 《Canadian journal of surgery》1987,30(6):442-444
In order to determine if serial, noninvasive evaluation of polytetrafluoroethylene (PTFE) vascular access grafts could identify a subgroup of patients at risk for thrombosis, the authors studied flow characteristics, using duplex ultrasonic scanning, in 18 hemodialysis patients with forearm loop grafts. On average, five examinations were performed per patient over the 10-month study period. Seven episodes of thrombosis occurred in six patients. The mean Doppler flow in grafts that subsequently thrombosed was significantly lower than in those that did not (544 +/- 218 ml/min versus 843 +/- 391 ml/min, p less than 0.001). The interval from last examination to thrombosis ranged from 13 to 58 days. At a defined cut-off flow of 450 ml/min, this test yielded a sensitivity of 83% and a specificity of 75% for episodes of thrombosis occurring within 2 to 6 weeks. The authors conclude that episodes of thrombosis in PTFE arm loop grafts are usually preceded by significantly lower Doppler-measured flow than grafts that do not thrombose and that it may be possible, by this means, to identify grafts at risk. 相似文献
28.
Alan Willmore Tim Sladden Lucy Bates Craig B Dalton 《International journal of health geographics》2006,5(1):30-14
Background
To determine patterns of childhood lead exposure in a community living near a lead and zinc smelter in North Lake Macquarie, Australia between 1991 and 2002. 相似文献29.
30.
Kevin Gruffydd-Jones Sandra Hollinghurst Sabbi Ward Gordon Taylor 《The British journal of general practice》2005,55(521):918-923
BACKGROUND: There is a high non-attendance rate for traditional clinic-based routine asthma care in general practice. Alternative methods of providing routine asthma care need to be examined. AIM: To examine the cost and effectiveness of targeted routine asthma care in general practice using telephone triage, compared to usual clinic care. DESIGN OF STUDY: An open randomised controlled trial. SETTING: A single semi-rural practice in the southwest of England. METHOD: Adult patients with asthma were randomised to receive either their routine asthma care in the surgery or care by telephone triage. Asthma control parameters, health status and NHS resource utilisation were measured over the 12-month study period. RESULTS: One hundred and ninety-four patients were randomised and 35% per cent more patients (n = 84 versus n = 62) received more than one consultation in the telephone group. Asthma control as measured by the asthma control questionnaire (ACQ) was similar in the clinic and telephone groups: mean change in ACQ = -0.11 (95% CI = -0.32 to 0.11) versus -0.18 (95% CI = -0.38 to 0.02). Mean NHS costs were 210 pounds sterling per patient per year in the telephone group compared to 334 pounds sterling in the clinic group (P-value of bootstrapped difference = 0.071). CONCLUSION: Targeted routine asthma care by telephone triage of adult asthmatics can lead to more asthma patients being reviewed, at less cost per patient and without loss of asthma control compared to usual routine care in the surgery. 相似文献