首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   176篇
  免费   12篇
耳鼻咽喉   1篇
基础医学   27篇
口腔科学   1篇
临床医学   7篇
内科学   34篇
皮肤病学   1篇
神经病学   1篇
外科学   71篇
预防医学   11篇
药学   17篇
肿瘤学   17篇
  2021年   3篇
  2020年   1篇
  2019年   3篇
  2018年   4篇
  2017年   4篇
  2015年   3篇
  2013年   7篇
  2012年   12篇
  2011年   5篇
  2010年   3篇
  2009年   3篇
  2008年   9篇
  2007年   5篇
  2006年   10篇
  2005年   13篇
  2004年   11篇
  2003年   4篇
  2002年   7篇
  2001年   13篇
  2000年   9篇
  1999年   14篇
  1998年   3篇
  1997年   2篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1992年   5篇
  1991年   1篇
  1990年   3篇
  1989年   3篇
  1988年   4篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1975年   1篇
  1968年   1篇
排序方式: 共有188条查询结果,搜索用时 15 毫秒
71.
72.
BACKGROUND AND OBJECTIVES: An equivalence study was conducted in which the efficacy and safety of a daily dose of 800 microgram of beclomethasone diproprionate administered via a multidose powder inhaler, Easyhaler, and via a metered-dose inhaler (MDI) with a large-volume spacer were compared in adult, newly diagnosed, steroid-naive asthmatic patients. Acceptability of the medications was also compared. METHODS: One hundred and forty-four patients were recruited into the double-blind, double-dummy, randomised, parallel-group multicentre study. The study treatment period was 8 weeks. It was preceded by a 2-week run-in period. Morning and evening peak expiratory flow (PEF), numbers of inhalations of a sympathomimetic and asthma symptoms were recorded daily. Spirometry and histamine challenge were performed, and health-related quality of life and morning serum cortisol levels measured during control visits. RESULTS: Criteria indicating treatment equivalence were met. The mean of the primary outcome variable, morning PEF, increased significantly, from 426 to 461 litres/min in the Easyhaler group and from 436 to 467 litres/min in the MDI+spacer group. Similar improvements between groups were also seen in relation to all secondary variables. Changes in serum cortisol levels were minor. In 6 out of 10 questions about device acceptability, the majority of patients rated Easyhaler as better than the MDI+spacer combination. CONCLUSION: It was concluded that the devices tested were equivalent in terms of efficacy and safety.  相似文献   
73.
Koskela H  Taivainen A  Tukiainen H  Chan HK 《Chest》2003,124(1):383-391
STUDY OBJECTIVES: To identify which tests would be useful in selecting patients for a specific inhalation challenge with bovine dander allergens (bSIC). DESIGN: A prospective study. SETTING: A university hospital. PATIENTS: Thirty-seven dairy farmers with a clinical suspicion of occupational asthma due to bovine allergens. INTERVENTIONS: Each patient (n = 27) underwent histamine challenge, mannitol challenge, exhaled nitric oxide (NO) measurement, bovine-specific serum IgE measurement, and skin-prick test (SPT) with bovine allergens prior to undergoing a bSIC. RESULTS: Eleven patients responded to the inhalation challenge with bovine allergens. The sensitivity and specificity of the tests, based on this response, were 82% and 65%, respectively, for the histamine challenge; 20% and 94%, respectively, for the mannitol challenge; 27% and 77%, respectively, for the NO measurement; 82% and 100%, respectively, for the bovine-specific serum IgE measurement; and 100% and 50%, respectively, for the SPT. Multiple regression analysis revealed that only IgE-mediated sensitivity to bovine allergens, but neither bronchial hyperreactivity nor exhaled NO concentration, contributed significantly to the response. CONCLUSION: Only the SPT with bovine allergens and bovine-specific serum IgE measurements were useful in selecting patients for the bSIC. This challenge should not be performed in SPT-negative subjects. A diagnosis of occupational asthma due to bovine dander allergens could be made without an inhalation challenge test in asthmatic patients with high bovine-specific serum IgE levels. This practice would eliminate the need for the majority of bSICs.  相似文献   
74.
75.
Several epidemiological studies have revealed a large variety of adverse health effects related to exposure to microbes in moisture damaged buildings. Recently some evidence has been reported for a biochemical linkage between microbial exposure and the respiratory symptoms suffered by the occupants. The objective of the current study was to evaluate the value of nitric oxide (NO) measurements in determining the inflammatory status of airways in inhabitants of problem buildings. NO was measured by a chemiluminescence analyzer from the exhaled air. In addition, NO was determined as its metabolite nitrite from nasal lavage (NL) and induced sputum (IS) samples and also via the expression of inducible nitric oxide synthase (iNOS) in the cells. Occupants of moisture-damaged and reference schools were studied. The sampling was performed at the end of the spring term, at the end of the summer vacation, during the winter term, and after a 1-wk winter holiday. No statistically significant differences in NO levels were detected between the studied groups or between exposure and vacation periods. iNOS was not detected from IS or NL samples of the exposed occupants. These results suggest that NO measurements alone are not sufficient to quantify airway inflammation when evaluating subjects exposed to microbes present in moisture-damaged buildings.  相似文献   
76.
To determine the etiology of community-acquired pneumonia in the adult population of a defined area, specific antibody responses in paired serum samples, levels of circulating pneumococcal immune complexes in serum samples, and pneumococcal antigen in urine were measured. Samples (304 paired serum samples and 300 acute urine samples) were obtained from 345 patients > or =15 years old with community-acquired, radiologically confirmed pneumonia, which comprised all cases in the population of 4 municipalities in eastern Finland during 1 year. Specific infecting organisms were identified in 183 patients (including 49 with mixed infection), as follows: Streptococcus pneumoniae, 125 patients; Haemophilus influenzae, 12; Moraxella catarrhalis, 8; chlamydiae, 37 (of which, Chlamydia pneumoniae, 30); Mycoplasma pneumoniae, 30; and virus species, 27. The proportion of patients with pneumococcal infections increased and of those with Mycoplasma infections decreased with age, but for each age group, the etiologic profile was similar among inpatients and among outpatients. S. pneumoniae was the most important etiologic agent. The annual incidence of pneumococcal pneumonia per 1000 inhabitants aged > or =60 years was 8.0.  相似文献   
77.
78.
Planned ventral hernia is a management strategy in which the abdominal fascial layer has been left unclosed and the viscera are covered only with original or grafted skin. Leaving the fascia open can be deliberate or unavoidable and most commonly results from staged repair of the abdominal wall due to trauma, peritonitis, pancreatitis, abdominal vascular emergencies, or abdominal compartment syndrome. The abdominal wall defects can be categorized as type I or II defects depending on whether there is intact, stable skin coverage. In defects with intact skin coverage, the most commonly used methods are the components separation technique and a prosthetic repair, sometimes used in combination. The advantages of the components separation technique is the ability to close the linea alba at the midline, creating a better functional result than a repair with inert mesh. Although the reherniation risk seems higher after components separation, the risk of infection is considerably lower. With a type II defect, with absent or unstable skin coverage, fascial repair alone is inadequate. Of the more complex reconstruction techniques, the use of a free tensor fasciae latae (TFL) flap utilizing a saphenous vein arteriovenous loop is the most promising. The advantages of the TFL flap include constant anatomy of the pedicle, a strong fascial layer, large-caliber vessels matching the size of the AV loop, and the ability to use large flaps (up to 20 × 35 cm). Whatever technique is used, the repair of complex abdominal wall defects requires close collaboration with plastic and abdominal surgeons, which is best managed in specialized centers.  相似文献   
79.
Evaluation of blood flow in free microvascular flaps   总被引:2,自引:0,他引:2  
Free flap surgery is routine today, yet little is known of its pathophysiology. In this study, the authors evaluated the hemodynamics in different types of free microvascular flaps, by measuring intraoperative transit-time flow. Eighty-six free transplants--21 free TRAM flaps for breast reconstruction, 18 radial forearm flaps for head and neck reconstructions, and 47 muscle flaps for head and neck, trunk and lower extremity reconstructions--were studied. Donor artery flow was highest in the radial artery (mean: 57.5 +/- 50 (SD) ml/min) but dropped (p < 0.001) to one tenth (6.1 +/- 2 ml/min) after anastomosis. The flow was lowest (4.9 +/- 3 ml/min) in the recipient artery of the TRAM flap but, after anastomosis, increased significantly (13.7 +/- 5 ml/min) to the level of the flow in the donor artery. The donor-artery flow in muscle flaps had a mean of 15.9 +/- 11 ml/min, and it significantly increased after anastomosing (23.9 +/- 12 ml/min). Weight-related intake of blood was highest in the radial forearm flap (18.5 +/- 6 ml/ min/100g) and lowest in the TRAM flap (2.5 +/- 1 ml/min/100g). The study showed that blood flow through a free microvascular flap does not depend on recipient artery flow. Even low-flow arteries can be used as recipients, because the flow increases according to free-flap requirements. The blood flow through a free microvascular flap depends on the specific tissue components of the flap.  相似文献   
80.
The alveolar content of fibres and asbestos bodies was assessed by bronchoalveolar lavage (BAL) in 21 asbestos sprayers. Transmission and scanning electron microscopy (TEM and SEM) and two light microscopical (LM) methods, cytocentrifugation, and Millipore filtration were used. The subjects had been exposed mainly to crocidolite asbestos for an average of 2.8 (range 0.2-13) years in 1950-75. The mean (median) total fibre count (of asbestos bodies and uncoated fibres) per ml of BAL fluid was 5500 (2800) by TEM and 2900 (1000) by SEM. The mean (median) count of asbestos bodies per ml with LM was 810 (500) with cytocentrifugation and 750 (480) with Millipore filtration, 840 (320) by TEM, and 1750 (420) by SEM. The mean proportion of coated fibres was 35% by TEM and 45% by SEM. The mean length of the coated fibres was 22 (range 4-65) microns by TEM and 34 (range 4.5-170) microns by SEM. The total fibre count exceeded 1000 fibres per ml in 70% of the cases by TEM. Asbestos body counts exceeded 1 per ml in 95% of the cases by LM. The fibre counts by SEM were in good accordance with counts by TEM except in a few cases in which the TEM result was considerably higher. In these cases the proportion of coated fibres was also low. All four counting methods appeared to give consistent results in heavily exposed cases when fibre load in the lungs was high. The counting of asbestos bodies may, however, underestimate the total alveolar fibre load in some cases.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号