全文获取类型
收费全文 | 14440篇 |
免费 | 853篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 197篇 |
儿科学 | 433篇 |
妇产科学 | 220篇 |
基础医学 | 1589篇 |
口腔科学 | 401篇 |
临床医学 | 1186篇 |
内科学 | 3186篇 |
皮肤病学 | 328篇 |
神经病学 | 768篇 |
特种医学 | 586篇 |
外国民族医学 | 5篇 |
外科学 | 2120篇 |
综合类 | 494篇 |
一般理论 | 8篇 |
预防医学 | 955篇 |
眼科学 | 375篇 |
药学 | 1433篇 |
2篇 | |
中国医学 | 168篇 |
肿瘤学 | 934篇 |
出版年
2023年 | 166篇 |
2022年 | 475篇 |
2021年 | 686篇 |
2020年 | 400篇 |
2019年 | 548篇 |
2018年 | 623篇 |
2017年 | 392篇 |
2016年 | 488篇 |
2015年 | 495篇 |
2014年 | 636篇 |
2013年 | 776篇 |
2012年 | 1120篇 |
2011年 | 1106篇 |
2010年 | 722篇 |
2009年 | 512篇 |
2008年 | 748篇 |
2007年 | 760篇 |
2006年 | 668篇 |
2005年 | 608篇 |
2004年 | 503篇 |
2003年 | 398篇 |
2002年 | 374篇 |
2001年 | 208篇 |
2000年 | 184篇 |
1999年 | 172篇 |
1998年 | 115篇 |
1997年 | 82篇 |
1996年 | 86篇 |
1995年 | 70篇 |
1994年 | 70篇 |
1993年 | 70篇 |
1992年 | 80篇 |
1991年 | 95篇 |
1990年 | 86篇 |
1989年 | 102篇 |
1988年 | 69篇 |
1987年 | 78篇 |
1986年 | 71篇 |
1985年 | 62篇 |
1984年 | 45篇 |
1983年 | 28篇 |
1982年 | 39篇 |
1981年 | 38篇 |
1980年 | 38篇 |
1979年 | 43篇 |
1978年 | 32篇 |
1977年 | 30篇 |
1976年 | 19篇 |
1975年 | 33篇 |
1974年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Izaz Ahmad Mudasir Iqbal Asim Abbas Yasir Irfan Badrashi Arshad Jamal Shahid Ullah Ahmed M. Yosri Moustafa Hamad 《Materials》2022,15(9)
Steel fibers are widely extracted from scrap tyres, causing environmental concerns. This paper presents the use of steel fibers in variable proportions extracted from scrap tyres. The enhancement of the confinement was envisaged through the addition of steel fibers obtained from scrap tyres. The study included an experimental program for the development of constitutive material models for ordinary Portland cement (OPC) concrete and concrete with added steel fibers. A mix design was carried out for OPC, targeting a compressive strength of 3000 psi. Steel fibers were added to OPC in ratios of 1.0% to 3.0%, with an increment of 0.5%. Concrete columns, with cross-sectional dimensions of 6 × 6 inches and a length of 30 inches, were cast with both OPC and fiber-reinforced concrete. The column confinement was evaluated with a different spacing of ties (3- and 4-inch center-to-center). Compression tests on the concrete columns indicate that the addition of steel fibers to a concrete matrix results in an appreciable increase in strength and ductility. Overall, increasing the percentage of steel fibers increased the compression strength and the ductility of concrete. The maximum strain in the concrete containing 2.5% steel fibers increased by 285% as compared to the concrete containing 1% of steel fibers. An optimum percentage of 2.5% steel fibers added to the concrete resulted in a 39% increase in compressive strength, accompanied by a significant improvement in ductility. The optimum content of steel fibers, when used in confined columns, showed that confined compression strength increased with the addition of steel fibers. However, it is recommended that additional columns on the basis of the optimum steel fiber content shall be tested to evaluate their effectiveness in reducing the stirrup spacing. 相似文献
82.
Osama Y Kentab Ahmad A Al Ibrahim Khaled R Soliman Marzooqah Alanazi Ahmed Alsunaid Abdalmohsen Ababtain Abdulaziz I Alresseeni Abdulaziz Algarni Khlalid Aljohani Muna Aljahany 《The Journal of international medical research》2022,50(5)
ObjectiveThis study investigated the role of objective olfactory dysfunction (OD) and gustatory dysfunction (GD) testing among patients with suspected coronavirus disease 2019 (COVID-19) who presented with respiratory symptoms.MethodsA prospective, blinded, observational study was conducted in the emergency units of two tertiary hospitals. Participants were asked to identify scents in the pocket smell test (PST) and flavors in four different solutions in the gustatory dysfunction test (GDT). We assessed the level of agreement between objective findings and self-reported symptoms. We evaluated the diagnostic accuracy of chemosensory dysfunction for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.ResultsOf 250 participants, 74 (29.6%) were SARS-CoV-2-positive. There was slight agreement between self-reported symptoms and objective findings (kappa = 0.13 and 0.10 for OD and GD, respectively). OD assessed by the PST was independently associated with COVID-19 (adjusted odds ratio = 1.89, 95% confidence interval, 1.04–3.46). This association was stronger when OD was combined with objective GD, cough, and fever (adjusted odds ratio = 7.33, 95% confidence interval, 1.17–45.84).ConclusionsNeither the PST nor GDT alone are useful screening tools for COVID-19. However, a diagnostic scale based on objective OD, GD, fever, and cough may help triage patients with suspected COVID-19. 相似文献
83.
84.
ObjectiveTo ascertain changes in fertility in post Fournier's gangrene patients on account of changed scrotal environment.MethodsSixty post Fournier's patients were as cases and 50 non Fournier's individuals aptlyserved as controls. All subjects were followed up for 1 year. Aspects of fertility were investigated by means of a seminogram at 6 months and analysis for volume, viscosity, sperm concentration, motility and morphology according to WHO guidelines was done. Ability of the couples to conceive children in 1 year was also noted. The control group was investigated similarly and values were compared for significance.ResultsThe seminogram results were found out to be highly significant as there was marked difference in values (chi-square value 6.28, P-value< 0.012) whereas there was no significant association between attaining pregnancy at 1 year in two groups.ConclusionsA readily palpable difference in the seminogram values observed in Fournier's patients is the most significant finding of this study. Also highlighted was that despite such seminogram changes the overall ability of the couple to achieve pregnancy remains unaltered. 相似文献
85.
86.
Darwazah AK 《Journal of cardiothoracic surgery》2012,7(1):62
ABSTRACT: Prosthetic valve dysfunction at aortic position is commonly caused by pannus formation. The exact etiology is not known. It arises from ventricular aspect of the prosthesis encroaching its leaflets causing stenosis or it may remain localized causing left ventricular outflow tract obstruction without affecting valve function. The difference in location entails different approaches in management. Such a pathology requires surgical excision of the pannus with or without valve re-replacement. A recurrent pannus was observed in a female patient who needed repeated surgical intervention to excise a localized pannus without re-replacement of a well functioning prosthetic valve. Management of our case presents several questions, whether recurrence of pannus is caused by sparing the prosthetic valve, is it simply an exaggeration of an inflammatory healing process in certain individuals or is it ideal to re-replace the valve despite a well preserved function. 相似文献
87.
Lorna A. Brudie Giorgia Gaia Sarfraz Ahmad Neil J. Finkler Glenn E. Bigsby IV Giselle B. Ghurani James E. Kendrick IV Joseph A. Rakowski Jessica H. Groton Robert W. Holloway 《Journal of robotic surgery》2012,6(4):317-322
We analyzed peri-operative outcomes of 80 patients who underwent robotic-assisted laparoscopic surgery and were diagnosed with stage IV endometriosis (revised American Society for Reproductive Medicine) between January 2007 and December 2010 at a tertiary gynecologic oncology referral center with a fellowship training program. Eligible women had a combination of one or more factors: pelvic mass, sub-acute or chronic pelvic pain, dysmenorrhea, dyspareunia, elevated serum CA-125, diagnosed with stage IV endometriosis at surgery with robotic-assisted gynecologic procedures using the da Vinci? Surgical System. The mean age was 43.7?±?7.0?years, body mass index 27.5?±?7.4?kg/m2, and 23 (28.9%) patients had prior endometriosis surgery. Presenting symptoms included: chronic pelvic pain (48.8%), dysmenorrhea (40.3%), and dyspareunia (33.8%). Sixty-nine (86%) patients had pelvic masses (43 unilateral and 26 bilateral). Thirty-seven (46.3%) had elevated CA-125 levels (mean 97.9?±?71.6 U/ml). Forty-eight (60%) underwent robotic-assisted laparoscopic hysterectomy (RALH)/bilateral salpingo-oophorectomy (BSO), 9 (11.3%) RALH/unilateral salpingo-oophorectomy (USO), 5 (6.3%) modified radical hysterectomy, and 10 (13%) USO or BSO only. Four (5%) had ovarian cystectomies with excision of endometriotic implants. Three (3.8%) underwent appendectomy and no patient required bowel resection. Four (5%) patients required conversion to laparotomy during the first 15 cases of this series [dense adhesions (3) and ureteral injury (1)]. Mean operative time was 115?±?46?min, blood loss 88?±?67?ml, and length of stay 1.0?±?0.4?days. There were four (5%) complications (ureteral injury, cuff abscess, cuff hematoma, re-admission for nausea and vomiting secondary to narcotics) and no transfusions. One (1.3%) patient underwent a second surgery for pain (dyspareunia). Robotic-assisted surgery for stage IV endometriosis resulted in excellent pain relief, with few laparotomy conversions or complications during a robotic learning-curve experience. 相似文献
88.
89.
Ahmad Azhar 《Journal of the Saudi Heart Association》2012,24(3):195-199
Neonatal fungal endocarditis is a rare but serious infection, which does not have a well-accepted management method. This is the second report of this condition in Saudi Arabia. A preterm, very low birth weight, female neonate presented with fever and shortness of breath. An echocardiogram showed moderate pericardial effusion and two masses in the heart, one in the right ventricle and the other in the inferior portion of the posterior mitral valve of the left ventricle. Blood and pericardial fluid cultures revealed an infection with Candida albicans. The patient received a 60 days course of intravenous fluconazole and amphotericin B lipid complex. At the conclusion of treatment, she was discharged in good condition with no echocardiographic evidence of pericardial effusion or fungal vegetations. Thus, a successful outcome to a serious case of fungal endocarditis was achieved through aggressive antifungal therapy with intravenous fluconazole and amphotericin B lipid complex. 相似文献