全文获取类型
收费全文 | 2515篇 |
免费 | 148篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 77篇 |
妇产科学 | 49篇 |
基础医学 | 255篇 |
口腔科学 | 154篇 |
临床医学 | 382篇 |
内科学 | 747篇 |
皮肤病学 | 15篇 |
神经病学 | 101篇 |
特种医学 | 89篇 |
外科学 | 343篇 |
综合类 | 10篇 |
预防医学 | 204篇 |
眼科学 | 13篇 |
药学 | 153篇 |
中国医学 | 1篇 |
肿瘤学 | 67篇 |
出版年
2023年 | 24篇 |
2022年 | 13篇 |
2021年 | 54篇 |
2020年 | 29篇 |
2019年 | 60篇 |
2018年 | 55篇 |
2017年 | 54篇 |
2016年 | 50篇 |
2015年 | 61篇 |
2014年 | 62篇 |
2013年 | 106篇 |
2012年 | 166篇 |
2011年 | 184篇 |
2010年 | 102篇 |
2009年 | 77篇 |
2008年 | 130篇 |
2007年 | 169篇 |
2006年 | 158篇 |
2005年 | 142篇 |
2004年 | 121篇 |
2003年 | 105篇 |
2002年 | 108篇 |
2001年 | 55篇 |
2000年 | 68篇 |
1999年 | 67篇 |
1998年 | 22篇 |
1997年 | 20篇 |
1996年 | 19篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 21篇 |
1992年 | 38篇 |
1991年 | 35篇 |
1990年 | 23篇 |
1989年 | 35篇 |
1988年 | 16篇 |
1987年 | 19篇 |
1986年 | 16篇 |
1985年 | 18篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 9篇 |
1972年 | 12篇 |
排序方式: 共有2675条查询结果,搜索用时 15 毫秒
41.
Johnsrude CL Backer CL Deal BJ Strasburger JF Mavroudis C 《Journal of cardiovascular electrophysiology》1999,10(3):351-357
INTRODUCTION: Some patients with postoperative congenital heart disease require permanent cardiac pacing, but the use of transvenous or epicardial pacing leads may be limited by type of cardiac malformation, venous connections, body size, or fibrosis. Transmural atrial pacing may provide an alternative in difficult patients, but to date has been described in only a few articles with small patient numbers, and data from lead performance are lacking. METHODS AND RESULTS: Records were reviewed in 18 consecutive patients (4 months to 21 years old) with postoperative congenital heart disease receiving transmural atrial pacing leads from July 1994 to December 1996. Implantation materials and techniques were described. Lead sensing and capture thresholds obtained acutely and during short-term follow-up (mean: 11.0 months) were evaluated, and comparisons were made between patients with postoperative Fontan anatomy and non-Fontan patients, and between patients receiving steroid-eluting and nonsteroid leads. Overall, the median acute sensing and capture thresholds of transmural leads were 4.1 m V and 0.7 V at 0.5 msec, respectively. Median follow-up thresholds were 2.8 m V and 0.8 V, respectively. Performance of leads in Fontan patients was similar to those in non-Fontan patients. Steroid-eluting leads had a chronic capture threshold of 0.6 V versus 0.9 V for nonsteroid leads (P = 0.038). CONCLUSION: Transmural atrial pacing leads were successfully implanted in patients with diverse ages and types of postoperative congenital heart disease. Lead performance was acceptable both acutely and during the first year of follow-up. 相似文献
42.
De Sutter J Van de Wiele C Gheeraert P De Buyzere M Gevaert S Taeymans Y Dierckx R De Backer G Clement D 《The American journal of cardiology》1999,83(2):255-7, A5
In patients treated successfully with primary angioplasty for a first myocardial infarction, the Selvester 32-point score correlates well with infarct size measured with quantitative thallium-201 perfusion imaging. Therefore, it is a useful parameter for infarct sizing, particularly in patients with anterior infarction or reduced ejection fraction at discharge. 相似文献
43.
Assessment of patient performance of the HandiHaler compared with the metered dose inhaler four weeks after instruction 总被引:2,自引:0,他引:2
The HandiHaler is a novel breath-actuated dry powder system designed for the delivery of tiotropium 18microg daily in the treatment of COPD. We compared patient ability to use the HandiHaler or metered dose inhaler (MDI) device correctly 4 weeks after receiving brief instructions and device demonstration. A single-blind study was conducted in COPD patients in two centers in Denmark. ALL patients (n = 151) received one placebo capsule via the HandiHaler daily and ipratropium (20 microg) two actuations via the MDI q.i.d. Mean FEV1 for all patients was 1.25 + 0.54 (46% predicted). Twelve instructions establishing proper device use were evaluated for the MDI and Handihaler. Error scores were analyzed by number of patients with less, equal or more errors when using HandiHaler compared to MDI in the total efficacy population (n = 139) and according to those who had not previously used an MDI for at least 12 months (MDI beginners) (n = 74) and those who had used an MDI (MDI experienced) (n = 65). Four weeks after device instruction, a higher proportion of patients in the total population (P < 0.01) had fewer errors with the HandiHaler (35.3%) compared to the MDI (15.1%). The number of errors was equal in 50% of patients. Similar findings were observed in the subgroup of patients who were MDI beginners (42% vs. 11%, P < 0.01) with non-significant trends in favor of the HandiHaler in those patients who were MDI experienced (29.7% vs. 18.9%, P = 0.096). Similar results in favor of HandiHaler were noted across different age and sex strata. The proportion of patients correctly using the device on the first of three attempts was 59.7% and 54.7% for the HandiHaler and MDI, respectively (P = 0.399). In summary, use of the HandiHaler can be easily taught with fewer errors compared to the MDI. Furthermore, patient performance using the HandiHaler was superior to that with an MDI despite prior MDI experience and more frequent usage. 相似文献
44.
Steen Nepper-Christensen Vibeke Backer Lawrence M DuBuske Hendrik Nolte 《Allergy and asthma proceedings》2003,24(4):253-258
For the diagnosis of allergy, presence of allergen-specific immunoglobulin E (IgE) usually is established either by allergen skin tests or by in vitro allergen-specific IgE measurements. However, in vitro assays of specific IgE often are modified as manufacturers improve allergens or change reagents to optimize test performance, affecting the diagnostic performance of in vitro allergen-specific IgE assays. This investigation compares the diagnostic outcomes of the Hitachi Chemical Diagnostics chemiluminescent assay (CLA) and Pharmacia, capsulated hydrophilic carrier polymer (CAP) in vitro allergen-specific IgE test methods in patients with inhalant allergy to a panel of selected allergens. Sera were obtained from 60 consecutive patients who had a clinical history suggesting inhalant allergy and were evaluated by allergen skin-prick test (SPT). Only patients with clinical findings of allergic asthma or rhinoconjunctivitis were included. Sera from patients with at least one positive SPT, which clinically correlated with the case history, were used for specific IgE measurements. Sensitivity and specificity were defined as conditional probabilities describing performances of the CAP system and the CLA system in reference to a standard composed of a combination of allergen-specific symptoms and a positive SPT. A test concordance of 79% was found between the CLA and CAP test results with a correlation coefficient of 0.8. Allergen-specific IgE assay sensitivity of the CLA and CAP systems was similar and allergen dependent, ranging from 67 to 100%. Assay specificity ranged from 39 to 86% for the CLA system and from 36 to 81% for the CAP system. When comparing the specific IgE results with allergen SPTs, 75% (+/- 3%) of CLApositive patients had a positive SPT, and 92% (+/- 4%) of CAPpositive patients had a positive SPT. Eighty-four percent (+/- 4%) of CLAnegative patients had a negative SPT, whereas 69% (+/- 5%) of CAPnegative patients had a negative SPT. The overall concordance between skin tests and in vitro tests was 76% for CLA and 67% for CAP. CLA and CAP score values showed good correlation and both tests may be useful when skin tests cannot be performed to identify subjects with IgE-mediated allergy. The CLA and CAP assays for allergen-specific IgE may be useful as part of an initial allergy evaluation because of the high negative predictive value of negative test results. For the majority of allergens the sensitivity was high. However, the specificity of both in vitro tests was low, indicating that positive in vitro test results should be evaluated carefully in conjunction with clinical symptoms and allergen-specific skin tests to determine the clinical relevance of the allergen sensitization. 相似文献
45.
Lieve Debruyne Dirk De Bacquer Stefaan De Henauw Lea Maes Lieven Annemans Guy De Backer 《European journal of cardiovascular prevention and rehabilitation》2006,13(5):711-717
BACKGROUND: Guidelines on the prevention of cardiovascular disease recommend screening in close relatives of patients with premature coronary heart disease (CHD). This family history puts them at increased risk for CHD, independent of other major risk factors, but screening for CHD risk factors in these relatives is not widely practiced in Europe. This demonstration project examined how to improve screening of close relatives of patients with premature CHD in daily practice. METHODS: A controlled study design was used. Four hospitals were compared in a pre-test as to the actual screening of relatives of patients with premature CHD. Then they were arranged in pairs and randomly assigned to the Usual care (U) or Intervention group (I). An information and health education program--involving patients, relatives and family doctors--was developed in I to improve screening by the family doctor. RESULTS: The pre-test confirmed that screening of relatives of patients with premature CHD is poorly practiced in the four regions; no significant differences between I and U were observed. The screening of relatives during the study period reached 63.9% in I compared to 25.4% in U. This difference between I and U was present in siblings and offspring. The cardiovascular risk profile of the relatives of I was not optimal and needed improvement. CONCLUSION: Screening of first-degree relatives of patients with premature CHD can be significantly improved through a health education program. This is the first and necessary step to improve the management of risk factors in these people, who are at increased risk for CHD. 相似文献
46.
A. De Backer MD P. Haentjens MD Dr. G. Willems MD 《Digestive diseases and sciences》1985,30(9):884-890
The effect of a single instillation of acid and pepsin on the cell proliferation in the distal esophageal mucosa was investigated in four dogs. The doses of acid and pepsin used were lower than those provoking acute esophagitis and erosions. Usingin vitro labeling with [3H]thymidine and autoradiography, the epithelial mitotic and DNA synthesis indices were determined at 0, 4, 8, 12, 16, 20, and 24 hr after instillation of saline, of acid alone, or of acid with pepsin. Instillation of acid alone was followed, 16 hr later, by an increase (P<0.01) in DNA synthetic activity in the proliferative area. A mitotic peak (P<0.01) started from the 20th hour. After instillation of acid with pepsin in the same animals, a similar sequence of kinetic phenomena was observed, suggesting that the concentration of pepsin used did not potentiate the stimulating effect of acid on the cell proliferation in this epithelium. Our data indicate that hydrochloric acid stimulates the proliferative activity in the normal esophageal epithelium.This work was supported in part by a grant for cancer research from the Algemene Spaar-en Lijfrentekas and by the Fonds voor Geneeskundig Wetenschappelijk Onderzoek. 相似文献
47.
Ellen De Backer Rita Verhelst Hans Verstraelen Geert Claeys Gerda Verschraegen Marleen Temmerman Mario Vaneechoutte 《BMC infectious diseases》2006,6(1):51
Background
Previous studies have indicated that a recently described anaerobic bacterium, Atopobium vaginae is associated with bacterial vaginosis (BV). Thus far the four isolates of this fastidious micro-organism were found to be highly resistant to metronidazole and susceptible for clindamycin, two antibiotics preferred for the treatment of BV. 相似文献48.
49.
50.
A team fares well with a fair coach: Predictors of social loafing in interactive female sport teams 下载免费PDF全文
M. De Backer F. Boen B. De Cuyper R. Høigaard G. Vande Broek 《Scandinavian journal of medicine & science in sports》2015,25(6):897-908
The present research aimed to develop and test a theoretical model that links players' perceived justice of the coach to a more optimal motivational climate, which in turn increases players' team identification and cohesion, and results in lower levels of social loafing in female sport teams. Belgian elite female basketball, volleyball, and football players (study 1; N = 259; Mage = 22.6) and Norwegian world‐class female handball players (study 2; N = 110; Mage = 22.8) completed questionnaires assessing players' perceived justice (distributive and procedural), motivational climate, team identification, team cohesion (task and social), and social loafing (perceived and self‐reported). In both studies, confirmatory and exploratory path analyses indicated that perceived justice was positively related to a mastery climate (P < 0.05) and negatively to a performance climate (P < 0.05). In turn, a mastery climate was linked to increased levels of team identification (P < 0.05) and task cohesion (P < 0.05). Consequently, players' perceived and self‐reported social loafing decreased (P < 0.05). The findings of both independent studies demonstrated the impact of coaches' fairness, and consequently, the motivational climate created by the coach on the optimal functioning of female sport teams. 相似文献