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   372篇
  免费   16篇
  国内免费   1篇
儿科学   63篇
妇产科学   6篇
基础医学   54篇
口腔科学   5篇
临床医学   23篇
内科学   122篇
皮肤病学   7篇
神经病学   27篇
特种医学   5篇
外科学   40篇
综合类   1篇
预防医学   10篇
眼科学   1篇
药学   20篇
肿瘤学   5篇
  2023年   3篇
  2021年   6篇
  2020年   3篇
  2019年   3篇
  2018年   2篇
  2016年   4篇
  2014年   7篇
  2013年   11篇
  2012年   16篇
  2011年   17篇
  2010年   7篇
  2009年   8篇
  2008年   22篇
  2007年   19篇
  2006年   23篇
  2005年   22篇
  2004年   19篇
  2003年   13篇
  2002年   20篇
  2001年   8篇
  2000年   17篇
  1999年   11篇
  1998年   4篇
  1997年   4篇
  1995年   8篇
  1994年   4篇
  1993年   2篇
  1992年   6篇
  1991年   7篇
  1990年   12篇
  1989年   10篇
  1988年   3篇
  1987年   8篇
  1986年   6篇
  1985年   8篇
  1984年   4篇
  1983年   6篇
  1981年   5篇
  1980年   3篇
  1979年   6篇
  1978年   4篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1972年   1篇
  1971年   3篇
  1970年   1篇
  1968年   1篇
  1944年   1篇
  1933年   1篇
排序方式: 共有389条查询结果,搜索用时 15 毫秒
1.
Eosinophilic activation in cystic fibrosis.   总被引:1,自引:1,他引:0       下载免费PDF全文
D Y Koller  M Gtz  I Eichler    R Urbanek 《Thorax》1994,49(5):496-499
BACKGROUND--The neutrophil is a potent contributor to pulmonary destruction in cystic fibrosis. Since eosinophils also possess destructive potential the involvement of eosinophils in cystic fibrosis has been investigated. METHODS--Eosinophil numbers and levels of eosinophil cationic protein (ECP), a marker of eosinophil activation, were determined in the serum of 42 patients with cystic fibrosis and in the sputum of 10 of them. To determine neutrophil activation levels of myeloperoxidase (MPO) were also measured. RESULTS--In cystic fibrosis increased serum levels of ECP were detected compared with healthy non-atopic subjects. Serum ECP levels were not related to the peripheral blood eosinophil count. A strong correlation with ECP concentrations in sputum indicated that the level of ECP in serum was representative of its pulmonary level. Levels of MPO were also increased in cystic fibrosis. A strong correlation was found between MPO and pulmonary function. In addition, ECP was related to arterial oxygen and carbon dioxide tensions. Antibiotic treatment reduced neutrophil activation without effect on ECP levels. CONCLUSIONS--Until now Pseudomonas aeruginosa and neutrophils were held to be primarily responsible for progressive tissue damage in cystic fibrosis. The results of this study suggest that eosinophils might also participate in such pulmonary destruction.  相似文献   
2.
3.
The effect of cow's milk consumption on childhood asthma has been debated for several years. This study attempts to provide further insight into this association through the use of a longitudinal study design. Newborns from parents with atopic history were recruited from Germany, Austria, and England (n = 696). For five repeated ascertainments, information was collected on cow's milk exposure, incidence of doctor-diagnosed asthma, and confounders. Generalized estimation equations, incorporating different models (concurrent, delayed, combined, and reverse causation), were used to determine this association. No association between cow's milk consumption and childhood asthma was found for the concurrent effects model (OR = 0.81, 95% confidence interval [CI]: 0.55, 1.20). In the delayed effects model, the direction of the association varied with time of follow-up. Thus, we stratified by period, which resulted in a significant protective delayed effect at 36 months (OR = 0.18, 95% CI = 0.06, 0.49). However, reverse causation negated this finding since the presence of asthma in prior months led to a reduction in further exposure to cow's milk (OR = 0.40, 95% CI = 0.16, 0.99). Hence, cow's milk consumption does not protect against childhood asthma. The apparent protection of cow's milk against asthma may result from parents of asthmatic children avoiding cow's milk, rather than actual prophylaxis.  相似文献   
4.
To study efficacy of a purified and biologically standardized house dust mite extract 66 allergic children were investigated. 26 patients on immunotherapy and 21 controls with symptomatic treatment only finished the study. A significant reduction of the skin reactivity associated with an increase of allergen specific IgG-antibodies was observed. However, no significant differences were found correlating the results of inhalative provocation tests, specific IgE antibodies and symptom scores. The immunotherapy with house dust mite extracts needs further evaluation.  相似文献   
5.
A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for allergen-specific IgG antibodies is described. Various solid-phase supports (microtiter plates), coating procedures, binding kinetics, and presentation of allergen in the assay were investigated. Using optimal conditions the indirect ELISA, in which the allergen is coated onto the well, was capable of detecting 2.4 ng/ml specific IgG antibodies to bee venom phospholipase A2(PLA2). The sandwich ELISA, in which the allergen was immobilized via specific antibody precoated onto the well, detected 0.24 ng/ml IgG antibodies to PLA2.  相似文献   
6.
OBJECTIVES: The goal of this study was to describe the mapping and ablation of polymorphic ventricular tachycardia (VT) after myocardial infarction (MI). BACKGROUND: The initiating mechanisms of polymorphic VT after MI have not been reported. METHODS: Five patients (four males; age 61 +/- 7 years) with recurrent episodes of polymorphic VT after anterior MI (left ventricular ejection fraction 32 +/- 7%) despite revascularization and antiarrhythmic drugs were studied. All patients demonstrated frequent ventricular premature beats (PBs) initiating polymorphic VT. Pace mapping and activation mapping were used to identify the earliest site of PB activity. The presence of a Purkinje potential preceding PB defined its origin from the Purkinje network. Electroanatomic voltage mapping was performed to delineate the extent of MI. RESULTS: The PBs were observed in all cases to arise from the Purkinje arborization in the MI border zone. These PBs were right bundle-branch block in all five patients, with morphologic variations in the limb leads in four; one also had a left bundle-branch block morphology. The coupling interval of the PB to the preceding QRS complex demonstrated significant variations (320 to 600 ms). During PB, the Purkinje potential at the same site preceded the QRS complex by 20 to 160 ms and was associated with different morphologies. Repetitive Purkinje activity was documented during polymorphic VT. Splitting of Purkinje activity and Purkinje to muscle conduction block were also observed. Ablation at these sites eliminated all PBs. At 16 +/- 5 months follow-up using defibrillator memory interrogation, no patient has had recurrence of arrhythmia. CONCLUSIONS: The Purkinje arborization along the border-zone of scar has an important role in the mechanism of polymorphic VT in patients after MI. Ablation of the local Purkinje network allows suppression of polymorphic VT.  相似文献   
7.
8.
9.

Background &; Aims

Wilson disease (WD) is an inherited disorder of copper disposition caused by an ATP7B transporter gene mutation, leading to copper accumulation in predisposed tissues. In addition to a genetic predisposition, other factors are likely to contribute to its clinical manifestation. The aim of the study was to assess whether oxidative stress affects the phenotypic manifestation of WD.

Methods

In 56 patients with WD (29 men; 26 with the hepatic form, 22 with the neurologic form, and eight asymptomatic; mean age 38.5?±?12 years), total serum antioxidant capacity (TAC) and inflammatory parameters (hs-CRP, IL-1??, IL-2, IL-6, IL-10, and TNF-??) were analyzed and related to the clinical manifestation, and mutations of the ATP7B gene. The control group for the TAC and inflammatory parameters consisted of 50 age- and gender-matched healthy individuals.

Results

WD patients had a significantly lower TAC (p?Conclusions Data from our study suggest that the increased oxidative stress contributes significantly to the clinical manifestation of WD; as a lower TAC is associated with the neurological symptoms in WD patients.  相似文献   
10.
Although reactive hyperemia index (RHI) predicts future coronary events, associations with intravascular ultrasound (IVUS)-assessed coronary plaque structure have not been reported. This study therefore investigated associations between RHI and IVUS-assessed coronary plaques. In 362 patients RHI was measured by noninvasive peripheral arterial tonometry and coronary plaque components (fibrous, fibrofatty, necrotic core, and dense calcium) were identified by IVUS in 594 vessel segments of the left anterior descending, circumflex, and/or right coronary arteries. RHI values <1.67 were considered abnormal. Analysis of variance was used to detect independent associations between RHI and plaque composition. Patients with an abnormal RHI had greater plaque burden (41% vs 39% in patients with normal RHI, p = 0.047). Compared to patients with normal RHI, plaque of patients with abnormal RHI had more necrotic core (21% vs 17%, p <0.001) and dense calcium (19% vs 15%, p <0.001) and less fibrous (49% vs 54%, p <0.001) and fibrofatty (11% vs 14%, p = 0.002) tissue. After adjustment for age, gender, cardiovascular risk factors, and drug therapy, abnormal RHI remained significantly associated with fibrous (F ratio 14.79, p <0.001), fibrofatty (F ratio 5.66, p = 0.018), necrotic core (F ratio 14.47, p <0.001), and dense calcium (F ratio 10.80, p = 0.001) volumes. In conclusion, coronary artery plaques of patients with abnormal RHI had a larger proportion of necrotic core and dense calcium. The association of an abnormal RHI with a plaque structure that is more prone to rupture may explain why these patients exhibit a greater risk of coronary events.  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