全文获取类型
收费全文 | 1781篇 |
免费 | 58篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 119篇 |
妇产科学 | 99篇 |
基础医学 | 153篇 |
口腔科学 | 56篇 |
临床医学 | 154篇 |
内科学 | 368篇 |
皮肤病学 | 61篇 |
神经病学 | 99篇 |
特种医学 | 114篇 |
外科学 | 351篇 |
综合类 | 17篇 |
预防医学 | 34篇 |
眼科学 | 26篇 |
药学 | 105篇 |
中国医学 | 5篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 26篇 |
2021年 | 39篇 |
2020年 | 27篇 |
2019年 | 29篇 |
2018年 | 35篇 |
2017年 | 39篇 |
2016年 | 53篇 |
2015年 | 55篇 |
2014年 | 90篇 |
2013年 | 116篇 |
2012年 | 151篇 |
2011年 | 126篇 |
2010年 | 70篇 |
2009年 | 48篇 |
2008年 | 86篇 |
2007年 | 116篇 |
2006年 | 124篇 |
2005年 | 134篇 |
2004年 | 119篇 |
2003年 | 94篇 |
2002年 | 71篇 |
2001年 | 20篇 |
2000年 | 24篇 |
1999年 | 22篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1981年 | 1篇 |
1980年 | 6篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有1841条查询结果,搜索用时 15 毫秒
21.
Hasan Yuksel Cengiz Kirmaz Ozge Yilmaz Ercan Pinar Seda Vatansever Papatya Bayrak Degirmenci Kemal Ozbilgin 《Annals of allergy, asthma & immunology》2008,100(1):12-16
BACKGROUND: Nitric oxide (NO) has contradictory roles in the pathophysiology of allergic inflammation in both allergic rhinitis (AR) and asthma. Small amounts of NO produced by constitutive NO synthase (NOS) is anti-inflammatory, whereas large amounts produced by inducible NOS (iNOS) are proinflammatory. OBJECTIVE: To investigate the difference in constitutive endothelial NOS (eNOS) and iNOS expression in nonallergic and allergic mucosa and the possible relation of this to the coexistence of asthma in seasonal AR. METHODS: Seventeen patients (10 women and 7 men) with seasonal AR and 9 nonallergic patients (5 women and 4 men) with nasal septum deviation were enrolled. Inferior turbinate nasal biopsy specimens were obtained in all. Levels of eNOS and iNOS expressed as immunohistochemical scores (HSCOREs) were determined immunohistochemically from the specimens. RESULTS: The mean +/- SD HSCOREs for eNOS in patients with seasonal AR were not significantly different from those of the nonallergic controls (1.85 +/- 0.78 vs 1.63 +/- 0.54; P = .12). On the other hand, the mean +/- SD HSCOREs for iNOS were significantly higher in patients with seasonal AR (1.75 +/- 0.75 vs 0.71 +/- 0.6; P = .004). Furthermore, although eNOS expression was not different between seasonal AR patients with and without asthma, the mean +/- SD HSCOREs for iNOS were significantly higher in the patients with asthma (1.93 +/- 0.78 vs 1.65 +/- 0.55; P = .01). CONCLUSION: Increased expression of iNOS might have a role in the development of allergic inflammation in upper and lower airways and in comorbidity of AR and asthma. 相似文献
22.
Arca M Montali A Ombres D Battiloro E Campagna F Ricci G Verna R 《Clinical genetics》2001,60(5):374-380
The anti-atherogenic effect of cholesteryl ester transfer protein (CETP) genetic variants associated with lowered enzyme activity is controversial. Moreover, in a few studies, this effect has been evaluated in the presence of a certain risk factor constellation. We addressed this issue in a case-control study, where 415 subjects with angiographically documented coronary artery disease (CAD +), 397 subjects without CAD (in 215, CAD was excluded by coronarography (CAD-)), and 188 healthy population controls, were screened for the CETP TaqIB polymorphism. The prevalence of the low-activity TaqIB2 allele was 0.396 in CAD+, and 0.428 and 0.416 in CAD- and population controls, respectively (p = 0.40). Its presence was significantly associated with increased high-density lipoprotein cholesterol (HDL-C) in population controls (1.40 +/- 0.40 mmol/l in B1B1, 1.52 +/- 0.39 mmol/l in B1B2 and 1.58 + 0.46 mmol/l in B2B2; p < 0.03 for trend), but not in the other groups. The CETP TaqIB polymorphism accounted for < 1% of the HDL-C variance in the whole cohort (p = 0.048). After adjustment for other risk factors, the CETP TaqIB2 allele was found not to be associated with significant changes in CAD risk independently of an assumed either dominant (odds ratio (OR) 0.97; 95% confidence interval (CI) 0.66-1.44; p = 0.89) or recessive effect (OR 0.68; 95% CI 0.42-1.12; p = 0.13). The CETP TaqIB polymorphism did not show a significant interaction with other risk factors in influencing CAD risk. Our findings do not support the hypothesis that a genetic variant resulting in lowered CETP activity is associated with reduced risk of coronary atherosclerosis. 相似文献
23.
Ozlem Dural Funda Gungor Ugurlucan Cenk Yasa Ercan Bastu Hulya Eren Bahar Yuksel Serdal Celik Suleyman Engin Akhan 《Journal of pediatric and adolescent gynecology》2017,30(1):e7-e10
Background
Isolated distal vaginal agenesis is a rare anomaly and mostly becomes symptomatic after menarche. We describe an unusual presentation of this anomaly in a prepubertal girl.Case
An 11-year-old prepubertal girl presented with recurrent urinary tract infection, pyuria, and right-sided renal agenesis. The findings of perineal inspection, ultrasonography, and magnetic resonance imaging were consistent with a distal vaginal agenesis with pyometrocolpos. Discharging pyometrocolpos with dissection of the atretic portion and a pull-through vaginoplasty were performed. A cystoscopy showed no sign of a vesicovaginal or uterine fistula.Summary and Conclusion
This rare presentation of distal vaginal agenesis reminds us that congenital malformations of the female genital tract should be considered in patients with congenital anomalies of the urinary system and/or recurrent urinary tract infection, even during the prepubertal period. 相似文献24.
Suleyman Ercan M.D. Gokhan Gokaslan M.D. Vedat Davutoglu M.D. Ibrahim Halil Inanc M.D. Vuslat Bosnak M.D. Hayati Deniz M.D. 《Echocardiography (Mount Kisco, N.Y.)》2013,30(8):E236-E238
Herein, we present a case of asymptomatic isolated cardiac cystic echinococcosis localized entirely to the inter‐atrial septum in a pregnant woman. The patient underwent successful surgery. Cardiac cystic echinococcosis is rarely seen in pregnancy. A high index of suspicion is necessary for the diagnosis of a cardiac cyst hydatid. The treatment of cardiac cyst hydatid is surgical and should not be delayed during pregnancy. Early surgery might prevent septic embolization and cardiac life‐threatening complications and save the lives of both mother and baby as in the present case. 相似文献
25.
Different approaches have been applied for quantitative analysis of EMG signals. This study introduces the effect of Multiscale Principal Component Analysis (MSPCA) denoising method in ElectroMyoGram (EMG) signal classification. The effect of the MSPCA denoising method discussed on EMG signal classification. In addition, effect of Multiple Single Classification (MUSIC) feature extraction method presented and compared for the classification of EMG signals. The results were accomplished on the basis of EMG signal data to classify into normal, ALS or myopathic. Furthermore, total accuracy of classifiers such as k-Nearest Neighbor (k-NN), Artificial Neural Network (ANN) and Support Vector Machines (SVMs) were discussed. Significant results were found by using MSPCA denoising method. The comparisons between the developed classifiers were based on a number of scalar performances such as sensitivity, specificity, accuracy, F-measure and area under ROC curve (AUC). The results show that MSPCA de-noising has considerably increased the accuracy as compared to EMG data without MSPCA de-noising. 相似文献
26.
Nuriye Aslı Melekoğlu Ali Bay Elif H. Aktekin Mehmet Yilmaz Ercan Sivasli 《Indian journal of hematology & blood transfusion》2017,33(2):211-215
Neonates born to mothers with immune thrombocytopenia (ITP) have an increased risk for neonatal thrombocytopenia and hemorrhagic complications. The aim of this study was to determine the maternal and neonatal outcomes of pregnancies with ITP and also to identify risk factors that predicts neonatal thrombocytopenia. We performed a retrospective analysis of 40 pregnancies with ITP and their 40 neonates. Among the 40 neonates, thrombocytopenia (platelet count of less than 150 × 109/L) was detected in 15 neonates (37.5 %) whom 8 of them had severe thrombocytopenia (platelet count of less than 50 × 109/L). Ten of the 15 neonates with thrombocytopenia required treatment to increase the platelet counts. There was statistically significant association between neonatal thrombocytopenia and maternal splenectomy history and maternal duration of thrombocytopenia. There was no statistically significant correlation between maternal platelet count and neonatal platelet count. Clinicians should pay special attention in these neonates because of risk for development of neonatal thrombocytopenia. Maternal and neonatal outcomes in patients with idiopathic thrombocytopenic purpura is generally good. 相似文献
27.
Effects of acute kidney injury on clinical outcomes in patients with upper gastrointestinal bleeding
Umit Cakmak Ozgur Merhametsiz Zafer Ercan Ayhan Haspulat Selma Karaahmetoglu Ozkan 《Renal failure》2016,38(2):176-184
Aim Upper gastrointestinal bleeding (UGIB) is a very frequently encountered condition that has a high morbidity and which increases treatment costs. Duration of hospital stay and mortality increases in patients with UGIB complicated by acute kidney injury (AKI). The aim of this study was to reveal risk factors in patients with UGIB developing AKI and to compare clinical outcomes and hospital costs between patients with UGIB developing AKI and those with UGIB not developing AKI.Material and methods This retrospective study included 245 patients admitted to the emergency unit and the intensive care unit for internal diseases at Ankara Numune Education and Research Hospital, Turkey. Results The difference in mortality rates between the patients with AKI and those without AKI was significant (p?0.001). The mean duration of intensive care unit stay was 0.2?±?1.1 days in the patients without AKI (n?=?143) and 2.5?±?5.6 days in the patients with AKI. It was significantly higher in the patients with AKI (p?0.001). Hospital stay was significantly longer in the patients with AKI than those without AKI, and as severity of AKI increased, hospital stay became considerably longer (p?0.001). Hospital costs were significantly higher in the patients with AKI than those without AKI, and as severity of AKI increased, hospital costs considerably rose (p?0.001). Conclusion AKI is a condition that lengthens hospital stay, increases hospital costs and creates a burden on health care systems. Detect kidney injury earlier and administering an appropriate treatment can improve clinical outcomes in patients with UGIB developing AKI. 相似文献
28.
29.
30.
Dear editor, Here, we discuss an unusual prosthesis migration to the thigh region. Because the incidence of erectile dysfunction increases in par-allel with the prevalence of neurological, degenerative and vascular diseases among elderly men, the use of penile prostheses is common in this age group. Still, cylinder migration following the implantation of a malleable penile prosthesis is a very rare entity. 相似文献