全文获取类型
收费全文 | 858篇 |
免费 | 49篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 59篇 |
妇产科学 | 24篇 |
基础医学 | 110篇 |
口腔科学 | 10篇 |
临床医学 | 62篇 |
内科学 | 182篇 |
皮肤病学 | 6篇 |
神经病学 | 45篇 |
特种医学 | 17篇 |
外科学 | 177篇 |
综合类 | 20篇 |
一般理论 | 2篇 |
预防医学 | 65篇 |
眼科学 | 3篇 |
药学 | 36篇 |
中国医学 | 3篇 |
肿瘤学 | 86篇 |
出版年
2023年 | 6篇 |
2022年 | 27篇 |
2021年 | 37篇 |
2020年 | 18篇 |
2019年 | 37篇 |
2018年 | 33篇 |
2017年 | 17篇 |
2016年 | 19篇 |
2015年 | 17篇 |
2014年 | 36篇 |
2013年 | 42篇 |
2012年 | 40篇 |
2011年 | 63篇 |
2010年 | 36篇 |
2009年 | 29篇 |
2008年 | 53篇 |
2007年 | 48篇 |
2006年 | 58篇 |
2005年 | 61篇 |
2004年 | 41篇 |
2003年 | 25篇 |
2002年 | 29篇 |
2001年 | 20篇 |
2000年 | 22篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有913条查询结果,搜索用时 15 毫秒
1.
M Ben Farhat H Boussadia I Gandjbakhch H Mzali A Chouaieb M Ayari K Ben Salah 《The Journal of thoracic and cardiovascular surgery》1990,99(4):639-644
Controversy persists regarding whether the efficacy of closed instrumental mitral commissurotomy compares well enough with that of open commissurotomy to warrant its continued use. The purpose of this study was to compare the results of operation as determined by catheterization studies in 63 patients with pure, severe, and noncalcified mitral stenosis. The patients were randomly assigned to one of two groups: thirty-two patients were operated on by the closed technique (group I) and 31 by the open technique (group II). All patients underwent left-sided and right-sided catheterization before and 4 months after operation. Preoperatively the two groups were statistically similar with regard to major clinical data and hemodynamic findings. There were no deaths at operation or systemic embolism in the two groups. The prevalence of surgically induced mitral regurgitation was similar in the two groups (12.4% versus 12.9%). Pulmonary arterial pressure and arteriolar and total pulmonary vascular resistance decreased significantly in the two groups. Pulmonary capillary wedge pressure decreased from 23.3 +/- 8.5 to 15.8 +/- 7 mm Hg in group I (p less than 0.001) and from 23.7 +/- 6 to 14 +/- 5.8 mm Hg in group II (p less than 0.001). Cardiac index increased from 2.86 +/- 0.84 to 3.14 +/- 0.78 L/min/m2 in group I, but this increase did not reach statistical significance. In group II cardiac index increased from 2.89 +/- 0.6 to 3.6 +/- 0.6 L/min/m2 (p less than 0.005). The mean and end-diastolic transmitral pressure gradients decreased significantly in the two groups, but the decrease was statistically greater in the open mitral commissurotomy group (p less than 0.001). Mitral valve area increased from 0.82 +/- 0.18 to 1.4 +/- 0.40 cm2 in group I (p less than 0.01) and from 0.84 +/- 0.15 to 2.14 +/- 0.53 cm2 in group II (p less than 0.001). The mean increase in mitral valve area was 0.61 cm2 in group I and 1.34 cm2 in group II (p less than 0.001). At exercise, in patients with resting pulmonary capillary wedge pressures of 18 mm Hg or less, cardiac index increased by 36% in group I (23 patients) and 48% in group II (24 patients), because of a smaller mitral valve area in group I (1.61 +/- 0.39 cm2) than in group II (2.45 +/- 0.65 cm2). Thus open commissurotomy improved hemodynamic values to a greater extent than closed commissurotomy at both rest and exercise.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
2.
A wide variety of health care options--home-based, indigenous, and cosmopolitan--exists in northern Balochistan, Pakistan. This paper examines health-seeking behavior in the area of mother and child health for villagers in this pluralistic medical setting. The analysis of a specific series of illness episodes shows that the majority of cases obtain treatment from different medical systems for a single episode. Interest in medications takes precedence over practitioners, and the meaning the villagers attach to such substances is explored. Long-established patterns of behavior relating to indigenous medicine continue to occur when cosmopolitan medicine is utilized. Information presented here helps to explain problems in utilization of cosmopolitan pharmaceuticals and delineates areas for future health programme activity. 相似文献
3.
4.
5.
Mehdi Slim Sameh Ben Farhat Sami Ben Ouannes Raoudha Chrigui Faten Yahya Houceme Thabet Houda Ghardallou Rym Gribaa Aymen Elhraiech Elies Neffati 《La Tunisie médicale》2022,100(6):450
Introduction . Percutaneous closure of congenital ventricular septal defects (VSDs) represents a promising alternative to surgery with lower rate of complications and shorter hospital stay. Its main limitation is the choice of the appropriate device for each type of defect. Aim. To report the experience of the service of cardiology (Sahloul hospital, Sousse, Tunisia) in percutaneous closure of congenital VSDs with Amplatzer Duct Occluder II (ADOII). Methods. This was a retrospective, monocentric study, conducted from January 2013 to December 2017. The study included patients treated by percutaneous closure of congenital VSDs with the ADOII device. Results. Twelve patients (6 boys; 6 girls) were included. The mean±SD of patients’ age and weight were 65±41 months and 23±10 kg, respectively. VSDs were peri-membranous (n=9) and muscular (n=3), and defects were restrictive (n=11) and non-restrictive (n=1). The mean (minimum-maximum) size of VSDs was 4.72 (3-6) mm. Eleven ADOII prostheses were successfully implanted. One failure procedure was noted with migration of the device into the pulmonary artery. A second child with perimembranous defect developed transient atrioventricular block. No deaths occurred. Conclusion. The present early experience shows that percutaneous closure with ADOII device of perimembranous and trabecular VSDs is safe and effective. 相似文献
6.
Polyphenols and Their Role in Obesity Management: A Systematic Review of Randomized Clinical Trials 下载免费PDF全文
Polyphenols have been suggested to reduce body weight and modify body composition through different mechanisms. These effects have been extensively studied in animals and in vitro and to a lesser extent in humans. The aim of this review is to consider the association between polyphenols and body weight status by focusing on human intervention studies. We conducted a systematic literature search in MEDLINE (via EBSCOhost), ProQuest CENTRAL, and Cochrane CENTRAL without time restrictions. Randomized controlled trials assessing the effect of polyphenols on weight and/or body composition in the overweight and/or obese population were included. Nineteen studies met our inclusion criteria. Results suggest that further research is required before supporting a potential role of polyphenols in reducing weight in overweight and obese individuals (nine studies showed a significant decrease in weight by a mean of 1.47 ± 0.58 kg). Nevertheless, several studies indicated that polyphenols might be effective in preventing small increases in weight during periods of overfeeding rather than reducing weight as such. The outcomes noted do not yet support polyphenol supplementation as a complementary approach in weight loss diets. Further larger trials with a duration of 12 months or more are needed to elucidate the effect of polyphenols on body weight status. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
7.
Fouad Damiri Swetha Andra Nagavendra Kommineni Satheesh Kumar Balu Raviteja Bulusu Amira A. Boseila Damilola O. Akamo Zubair Ahmad Farhat S. Khan Md. Habibur Rahman Mohammed Berrada Simona Cavalu 《Materials》2022,15(15)
Water contamination is one of the most urgent concerns confronting the world today. Heavy metal poisoning of aquatic systems has piqued the interest of various researchers due to the high toxicity and carcinogenic consequences it has on living organisms. Due to their exceptional attributes such as strong reactivity, huge surface area, and outstanding mechanical properties, nanomaterials are being produced and employed in water treatment. In this review, recent advances in the use of nanomaterials in nanoadsorptive membrane systems for wastewater treatment and heavy metal removal are extensively discussed. These materials include carbon-based nanostructures, metal nanoparticles, metal oxide nanoparticles, nanocomposites, and layered double hydroxide-based compounds. Furthermore, the relevant properties of the nanostructures and the implications on their performance for water treatment and contamination removal are highlighted. The hydrophilicity, pore size, skin thickness, porosity, and surface roughness of these nanostructures can help the water permeability of the nanoadsorptive membrane. Other properties such as surface charge modification and mechanical strength can improve the metal adsorption effectiveness of nanoadsorptive membranes during wastewater treatment. Various nanocomposite membrane fabrication techniques are also reviewed. This study is important because it gives important information on the roles of nanomaterials and nanostructures in heavy metal removal and wastewater treatment. 相似文献
8.
Raazia Tasadduq Laiba Ajmal Farhat Batool Tehniyat Zafar Aleena Babar Amna Riasat Abdul-Rauf Shakoori 《Human immunology》2021,82(3):162-169
Maintenance and progression of pregnancy is an intricate process governed by a variety of developmental cues. Recurrent pregnancy loss (RPL) is a complication experienced by expecting mothers that is defined as three or more consecutive pregnancy losses. This review focuses on the dysfunctions of the immune system as one of the key contributors towards RPL. The current data suggests that the alloimmune and autoimmune factors contribute to the loss of fetus. Such causes despite being recognized as a definitive reason for recurrent pregnancy loss, are still under extensive investigation with new parameters being discovered and scrutinized for their association with RPLs. More in-depth and high throughput studies are required for devising better diagnostic tools and management strategies for the affected female so that they can carry their pregnancy to term. 相似文献
9.
Mohammad Khalid Parvez Deepak Sehgal Shiv Kumar Sarin Seemi Farhat Basir Shahid Jameel 《World journal of gastroenterology : WJG》2006,12(19)
AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine.METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization.RESULTS: IFN-γ at 0.1 to 5 μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells.At 5 μg/L, IFN-γ also suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γ showed no additive effect,sequential treatment first with lamivudine and then IFN-γ was found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2 μmol/L lamivudine for two days, followed by 1 μg/L IFN-γ for another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2 μmol/L lamivudine for two days, followed by 5 μg/L IFN-γ for six days showed a 72% reduction in HBV cccDNA pool.CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γ and lamivudine,especially in IFN-α non-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants. 相似文献
10.