全文获取类型
收费全文 | 3215篇 |
免费 | 172篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 70篇 |
妇产科学 | 25篇 |
基础医学 | 510篇 |
口腔科学 | 411篇 |
临床医学 | 214篇 |
内科学 | 709篇 |
皮肤病学 | 57篇 |
神经病学 | 317篇 |
特种医学 | 99篇 |
外科学 | 324篇 |
综合类 | 6篇 |
预防医学 | 177篇 |
眼科学 | 49篇 |
药学 | 221篇 |
中国医学 | 11篇 |
肿瘤学 | 179篇 |
出版年
2023年 | 23篇 |
2022年 | 44篇 |
2021年 | 87篇 |
2020年 | 47篇 |
2019年 | 62篇 |
2018年 | 92篇 |
2017年 | 67篇 |
2016年 | 87篇 |
2015年 | 86篇 |
2014年 | 142篇 |
2013年 | 158篇 |
2012年 | 256篇 |
2011年 | 267篇 |
2010年 | 154篇 |
2009年 | 138篇 |
2008年 | 243篇 |
2007年 | 210篇 |
2006年 | 215篇 |
2005年 | 168篇 |
2004年 | 177篇 |
2003年 | 179篇 |
2002年 | 109篇 |
2001年 | 39篇 |
2000年 | 32篇 |
1999年 | 38篇 |
1998年 | 17篇 |
1997年 | 31篇 |
1996年 | 22篇 |
1995年 | 26篇 |
1994年 | 17篇 |
1993年 | 3篇 |
1992年 | 28篇 |
1991年 | 16篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 6篇 |
1966年 | 2篇 |
1932年 | 2篇 |
1914年 | 2篇 |
排序方式: 共有3399条查询结果,搜索用时 9 毫秒
51.
Francisco Leonardo Galastri Guilherme Moratti Gilberto Breno Boueri Affonso Leonardo Guedes Moreira Valle Priscila Mina Falsarella Adriano Mendes Caixeta Camila Antunes Lima Marcela Juliano Silva Lucas Lembran a Pinheiro Conrado Dias Pacheco Annicchino Baptistella M rcio Dias de Almeida Rodrigo Gobbo Garcia Nelson Wolosker Felipe Nasser 《World journal of hepatology》2020,12(7):399-405
BACKGROUND Percutaneous transluminal angioplasty and stenting represent an effective treatment for hepatic artery stenosis after liver transplantation. In the first year after stenting, approximately 22% of patients experience in-stent restenosis, increasing the risk of artery thrombosis and related complications, and 50% experience liver failure. Although angiography is an important tool for diagnosis and the planning of therapeutic interventions, it may raise doubts, especially in small-diameter arteries, and it provides low resolution rates compared with newer intravascular imaging methods, such as optical coherence tomography(OCT).CASE SUMMARY A 64-year-old male developed hepatic artery stenosis one year after orthotropic liver transplantation and was successfully treated with percutaneous transluminal angioplasty with stenting. Five months later, the Doppler ultrasound results indicated restenosis. Visceral arteriography confirmed hepatic artery tortuosity but was doubtful for significant in-stent restenosis(ISR) and intrahepatic flow reduction. To confirm ISR, identify the etiology and guide treatment, OCT was performed. OCT showed severe stenosis due to four mechanisms: Focal and partial stent fracture, late stent malapposition, in-stent neointimal hyperplasia, and neoatherosclerosis.CONCLUSION Intravascular diagnostic methods can be useful in evaluating cases in which initial angiography results are not sufficient to provide a proper diagnosis of significant stenosis, especially with regard to ISR. A wide range of diagnoses are provided by OCT, resulting in different treatment options. Interventional radiologists should consider intravascular diagnostic methods as additional tools for evaluating patients when visceral angiography results are unclear. 相似文献
52.
Gabriel S. A. Moreira Edson A. Adriano Marcia R. M. Silva Paulo S. Ceccarelli Antônio A. M. Maia 《Parasitology research》2014,113(5):1703-1711
A new species of myxosporea (Henneguya rotunda n. sp.) was found in the membrane of the gill arch and the fins of Salminus brasiliensis in the Mogi Guaçu River, municipality of Pirassununga, São Paulo state, Brazil. Morphological and morphometric analyses using light microscopy revealed parasites with similar characteristics at both infection sites. The mature spores found infecting the fins had oval spore body with 7.1?±?0.2 μm in length, 5.6?±?0.2 μm in width, 3.7?±?0.1 μm in thickness, 16.4?±?1.2 μm in length of the caudal process, and 23.6?±?1.1 μm in total length of the spore. In a frontal view, the polar capsule was observed to be symmetrical with 3.4?±?0.2 μm in length and 1.8?±?0.1 μm in width. Mature spores contain six to seven turns of the polar filaments. The morphometric data concerning the spores obtained from plasmodia from the membrane of the gill arch were similar to those from the fins. Ultrastructure analysis revealed that the plasmodial wall was formed by a single membrane and had numerous pinocytotic canals connecting the outside of the plasmodia to the ectoplasm zone. Beyond that, various electron-translucent vesicles also were observed at the periphery of the plasmodium. The molecular analyses of the 18S rDNA gene from the spores obtained from the gill arch membrane and fin membrane showed that these sequences shared 100 % similarity. Phylogenetic studies using maximum parsimony and maximum likelihood methods demonstrated the polyphyletic clustering of the myxosporean parasites of characiform fishes. H. rotunda n. sp. clustered as a sister species of Myxobolus pantanalis, also a parasite of S. brasiliensis. 相似文献
53.
54.
Alessia Rosetti Rosella Ferretti Leo Zanitti Adriano Casulli Claudio Villani Roberto Cirilli 《Journal of Pharmaceutical Analysis》2020,10(6):610-616
A direct enantio-, diastereo-, and chemo-selective high-performance liquid chromatographic method was developed for determining the content, enantiomeric purity, and related substances of the chiral antidepressant drug sertraline HCl in a single chromatographic run. The separation was achieved on a chiral stationary phase based on amylose tris(3-chloro-5-methylphenylcarbamate) under reversed-phase conditions. The method was optimized by evaluating the influence of the temperature and mobile phase composition on the retention and selectivity. The application of the single-run approach allowed to baseline resolve all investigated species in less than 15 min, without using buffers or tandem-coupled columns. The chromatographic method was validated according to the guidelines of the Official Medicines Control Laboratory and applied to control the content of sertraline HCl and related chiral substances in a generic antidepressant formulation. 相似文献
55.
56.
Juliana Pereira Borges Gustavo Santos Masson Eduardo Tibiri?á Marcos Adriano Lessa 《Arquivos brasileiros de cardiologia》2014,102(1):47-53
Background
Aerobic interval exercise training has greater benefits on cardiovascular function as compared with aerobic continuous exercise training.Objective
The present study aimed at analyzing the effects of both exercise modalities on acute and subacute hemodynamic responses of healthy rats.Methods
Thirty male rats were randomly assigned into three groups as follows: continuous exercise (CE, n = 10); interval exercise (IE, n = 10); and control (C, n = 10). Both IE and CE groups performed a 30-minute exercise session. The IE group session consisted of three successive 4-minute periods at 60% of maximal velocity (Max Vel), with 4-minute recovery intervals at 40% of Max Vel. The CE group ran continuously at 50% of Max Vel. Heart rate (HR), blood pressure(BP), and rate pressure product (RPP) were measured before, during and after the exercise session.Results
The CE and IE groups showed an increase in systolic BP and RPP during exercise as compared with the baseline values. After the end of exercise, the CE group showed a lower response of systolic BP and RPP as compared with the baseline values, while the IE group showed lower systolic BP and mean BP values. However, only the IE group had a lower response of HR and RPP during recovery.Conclusion
In healthy rats, one interval exercise session, as compared with continuous exercise, induced similar hemodynamic responses during exercise. However, during recovery, the interval exercise caused greater reductions in cardiac workload than the continuous exercise. 相似文献57.
Adriano Schimmenti Alessia Passanisi Alessia Maria Gervasi Sergio Manzella Francesca Isabella Famà 《Child psychiatry and human development》2014,45(5):588-595
Studies on the role played by attachment attitudes among late adolescents who show Problematic Internet Use (PIU) are still lacking. Three self-report measures concerning attachment attitudes, childhood experiences of abuse, and Internet addiction were administered to 310 students (49 % males) aged 18–19 attending the last year of high school. Students who screened positive for PIU were more likely to be male and to have suffered childhood experiences of physical and sexual abuse; they also scored higher than the other participants on scales assessing anxious and avoidant attachment attitudes. A logistic regression showed that the classification of participants in the PIU group was predicted by male gender, having suffered from physical and sexual abuse in childhood, and preoccupation with relationships. Keeping constant the effects of gender and childhood experiences of abuse in the equation model, increasing values of preoccupation with relationships were reflected by an exponential growth in the probability curve for PIU classification. Findings of the study support the hypothesis that insecure attachment attitudes (particularly the preoccupation with relationships) are involved in the development of PIU among late adolescents. 相似文献
58.
59.