全文获取类型
收费全文 | 603篇 |
免费 | 33篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 69篇 |
妇产科学 | 14篇 |
基础医学 | 65篇 |
口腔科学 | 11篇 |
临床医学 | 65篇 |
内科学 | 99篇 |
皮肤病学 | 7篇 |
神经病学 | 34篇 |
特种医学 | 67篇 |
外科学 | 49篇 |
综合类 | 8篇 |
预防医学 | 80篇 |
眼科学 | 6篇 |
药学 | 34篇 |
中国医学 | 3篇 |
肿瘤学 | 24篇 |
出版年
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 14篇 |
2015年 | 10篇 |
2014年 | 17篇 |
2013年 | 15篇 |
2012年 | 31篇 |
2011年 | 25篇 |
2010年 | 19篇 |
2009年 | 16篇 |
2008年 | 35篇 |
2007年 | 33篇 |
2006年 | 30篇 |
2005年 | 15篇 |
2004年 | 14篇 |
2003年 | 21篇 |
2002年 | 20篇 |
2001年 | 22篇 |
2000年 | 6篇 |
1999年 | 7篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 18篇 |
1995年 | 15篇 |
1994年 | 11篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 6篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1977年 | 7篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1974年 | 5篇 |
1972年 | 5篇 |
1969年 | 5篇 |
1968年 | 5篇 |
1967年 | 4篇 |
排序方式: 共有639条查询结果,搜索用时 31 毫秒
41.
42.
Preanalytical influences on the measurement of ghrelin 总被引:1,自引:0,他引:1
43.
The aim in this study was to find out if there were any revision operations in patients who underwent an arthroscopic partial meniscectomy and we attempted to identify the factor(s) that may be associated with the need for that revision. We reviewed 1,603 patients who underwent an arthroscopic partial meniscectomy, and 16 cases of revision were identified (rate 1%). Nine factors were analysed: age, sex, affected knee, affected meniscus, private or National Health Service (NHS) patient, symptoms prior to the most recent meniscectomy, type of tear, history of re-injury and the progression of Outerbridge changes to the articular surfaces. There was a significant risk for a revision meniscectomy in patients with horizontal/partial thickness tears compared to flap tears. No additional factor analysed was significantly associated with a revision procedure. 相似文献
44.
Laser Doppler fluxmetry (LDF) or photoplethysmography (PPG) are frequently used as non-invasive tools to assess skin blood flow. They are both thought to be suitable and interchangeable methods for the detection of sympathetically activated vasoconstrictive episodes that can be provoked by a voluntary deep inspiration (DI), the so-called inspiratory gasp response (IGR). However, a rigorous comparison of the two methods has not been reported in the literature. The aim of this study was to compare the detection of IGR with LDF and PPG. We investigated 14 healthy volunteers (five female, nine male, 25.4 +/- 2.7 years). A PPG probe was applied to the tip of the thumb of the dominant hand, a LDF sensor to the tip of the adjacent index finger. After adaptation and baseline measurements the subjects were asked to perform a DI with time intervals of 90, 60, 30 and 15 s. We found that both methods are useful to detect individual IGR. Overall correlation of IGR amplitude detected with LDF and PPG was significant (r=0.433). Surprisingly, there was a continuous increase of the correlation coefficient from the first (r=0.105) or second (r=-0.184) IGR to the fifth (r=0.727) IGR. This implies that experimental data obtained with PPG and LDF are not equivalent and that one has to be cautious regarding the comparison and interpretation of results obtained with these two different methods. 相似文献
45.
Hemodynamic effects of pneumoperitoneum in lithotomy position 总被引:2,自引:0,他引:2
AIM OF STUDY: The study investigates the haemodynamic effects of the varying intraabdominal pressures and patient positions during gynecological procedures employing pneumoperitoneum in lithotomy positions. METHODES: TEE was used to determine end-diastolic and end-systolic left ventricular surface areas and ejection fractions were calculated from these data. To evaluate intraabdominal volume shifts the diameter of the internal iliac vein was measured by mean of vaginal ultrasound. RESULTS: In the horizontal lithotomy position both LVEDA and LVESA increased when intraabdominal pressure increased by 10 and 15 mmHg, respectively. LVAEF significantly decreased when intraabdominal pressure increased by 15 mmHg. Also DVII decreased. In Trendelenburg position there was no change in LVEDA, LVESA, LVAEF and DVII. In Anti-Trendelenburg position LVEDA and LVESA decreased. However, LVAEF remained constant and DVII increased. CONCLUSION: The increase of the intraabdominal pressure in the lithotomy position results in an increase in intrathoracic volume and an decrease in LVAEF via elevation of the the lower extremities and compression of the splanchnic vessels. There are no changes in Trendelenburg position. However, in Anti-Trendelenburg position, gravity results in a decrease in intrathoracic blood volume. In the decreased, dilatated heart the increase in intrathoracic volume may increase myocardial wall tension and hence oxygen demand, ultimately leading to an acute heart failure. As a result laparoscopic procedures in horizontal lithotomy position should be avoided in patients with dilatative cardiomyopathy. 相似文献
46.
During 1998, the Department of Health proposed to use survival rates of cervical and breast cancer in the 1989/90 incidence cohort as indicators of care. Valid interpretation was of concern within Trent and the Trent Cancer Registry responded by performing additional analyses. Trent Cancer Registry registrations for 1989/90 were re-analysed and the stability of districts' ranks for that cohort was investigated using random simulation techniques. Stability of ranks across more recent cohorts was investigated and attempts made to use all available information.The Department of Health's analyses were confirmed by our re-analysis of the 1989/90 cohort: Rotherham residents appeared to have the "worst" survival for cervical cancer, and Sheffield residents for breast cancer, although not statistically significantly so. Random simulations indicated that ranks based on a single cohort are not stable: for example Sheffield (ranked tenth for 1-y breast cancer survival) was ranked third or better in 6% of randomisations. Ranks were also unstable across cohorts: for example Rotherham 1-y cervical cancer survival was ranked tenth for 1989/90, fifth for 1991/92 and tenth for 1993/94. Analysis of 3-y running averages provided better information than the league table approach. Most districts improved over time, to different degrees, and similar sized gaps remained between the "best" and the "worst" districts. This analysis illustrates the need to be circumspect when interpreting "league tables" based on a single year or cohort analysis. League tables are based on ranks: clearly a large difference in rank may reflect only trivial (ie medically unimportant) differences in actual outcome. Lack of a statistically significant difference in survival between two districts does not mean their survival is equivalent. Even for a common cancer, like breast cancer, rankings were unstable from cohort to cohort. At the Registry we propose to perform these trend analyses routinely in future, adjusting, when possible, for the effects of deprivation and stage at diagnosis. 相似文献
47.
Evaluating plasma levels of cortisol and corticosterone after ACTH-stimulation, and the urinary metabolites tetrahydrocortisone and tetrahydrocortisol in asthmatic children it could be demonstrated, that in most cases there was no suppression of adrenal function following treatment over 6 to 18 months with a daily dose of 200 to 300 microgram beclomethasone dipropionate. Since in a few patients suppression was found, an ACTH stimulation after a six months treatment is recommended. 相似文献
48.
Gastroduodenoscopy and retrograde cholangiopancreatography has been performed on 25 occasions in 20 children aged between 7 and 16. Radiographs of the clinically relevant duct or ducts were achieved in 96% of attempts, with no complications. The diagnostic information proved useful clinically; in particular it provided a precise map if biliary or pancreatic surgery was being contemplated. Several unexpected congenital duct anomalies were found. This and other recent reports, particularly from Germany, indicate that endoscopic retrograde cholangiopancreatography deserves greater application in children, and can also be used in babies. 相似文献
49.
50.