全文获取类型
收费全文 | 1017830篇 |
免费 | 61051篇 |
国内免费 | 3697篇 |
专业分类
耳鼻咽喉 | 14471篇 |
儿科学 | 30031篇 |
妇产科学 | 26736篇 |
基础医学 | 155472篇 |
口腔科学 | 29751篇 |
临床医学 | 83921篇 |
内科学 | 192999篇 |
皮肤病学 | 24379篇 |
神经病学 | 75337篇 |
特种医学 | 39354篇 |
外国民族医学 | 169篇 |
外科学 | 158477篇 |
综合类 | 19116篇 |
现状与发展 | 1篇 |
一般理论 | 214篇 |
预防医学 | 62361篇 |
眼科学 | 25151篇 |
药学 | 80065篇 |
1篇 | |
中国医学 | 3406篇 |
肿瘤学 | 61166篇 |
出版年
2018年 | 11648篇 |
2017年 | 8882篇 |
2016年 | 10254篇 |
2015年 | 11509篇 |
2014年 | 14787篇 |
2013年 | 21195篇 |
2012年 | 29683篇 |
2011年 | 30757篇 |
2010年 | 18233篇 |
2009年 | 16560篇 |
2008年 | 29475篇 |
2007年 | 32015篇 |
2006年 | 32187篇 |
2005年 | 31181篇 |
2004年 | 30008篇 |
2003年 | 28997篇 |
2002年 | 28502篇 |
2001年 | 54713篇 |
2000年 | 56135篇 |
1999年 | 46543篇 |
1998年 | 11615篇 |
1997年 | 9796篇 |
1996年 | 9337篇 |
1995年 | 8491篇 |
1994年 | 7792篇 |
1993年 | 7353篇 |
1992年 | 32516篇 |
1991年 | 31954篇 |
1990年 | 31520篇 |
1989年 | 30638篇 |
1988年 | 27832篇 |
1987年 | 27228篇 |
1986年 | 25415篇 |
1985年 | 24042篇 |
1984年 | 17164篇 |
1983年 | 14370篇 |
1982年 | 7767篇 |
1979年 | 15723篇 |
1978年 | 10897篇 |
1977年 | 9324篇 |
1976年 | 8362篇 |
1975年 | 9898篇 |
1974年 | 11547篇 |
1973年 | 10772篇 |
1972年 | 10575篇 |
1971年 | 10202篇 |
1970年 | 9351篇 |
1969年 | 9053篇 |
1968年 | 8390篇 |
1967年 | 7519篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
G. Gherardini R. Zaccheddu S. M. Milner M. El-Shazlyl I. Liapakis 《European journal of plastic surgery》2006,29(1):9-12
Breast augmentation is one of the most frequently performed cosmetic surgery procedures worldwide. We report on a series of 502 consecutive cosmetic breast augmentations by a single surgeon, using both the submuscular and submammary approaches. A vacuum drain was placed in the surgical pocket at the end of the procedure. The drain fluid collection was recorded immediately after the surgery and the following day before removal. A tenfold increase in the amount of fluid collection was noted in the drain’s reservoir. Thirteen patients presented with minor wound healing problems at the second postoperative follow-up, which were treated conservatively; two of them had the implant removed and replaced after 2 months. There were only two capsular contractions at 1-year follow-up. We focus our discussion on the drainage in the early postoperative period and conclude that the routine use of a surgical drainage reduces the risk for complications. Based on our findings, we advocate that short-term routine use of a surgical drain is advisable. 相似文献
993.
E Erdogan O Ongürü N Bulakbasi A Baysefer F Gezen E Timurkaynak 《Minimally invasive neurosurgery》2003,46(1):50-53
Intracerebral and intramedullary schwannomas are uncommon; but, in general, spinal intramedullary schwannomas are more frequent than intracerebral schwanomas. We present a case of right lateral ventricle schwannoma in a 21-year-old man and review the associated literature. The 21-year-old right-handed man presented with loss of the left-eye vision approximately 8 months before referral to an ophthalmologist. The patient was immediately subjected to computed tomography (CT) scan, which showed an enhanced lesion with cystic component in the right occipital horn of the lateral ventricle. And consecutively, he was admitted to our department. The tumor was evacuated via craniotomy with marked improvement in his clinical state. The postoperative course was uneventful and postoperative CT control showed no residue. On MRI control no recurrence was noted after a follow-up period of 8 years. Intracerebral schwannoma is a rare, benign neoplasm. It is usually located superficially or adjacent to a ventricle. Characteristic imaging features include cyst formation, calcification, and evidence of peritumoral edema or gliosis. The recognition of this benign and potentially curable neoplasm and its differentiation from other neoplasms, some of which have less favourable outcomes, is of obvious importance. 相似文献
994.
995.
G Weiss†‡ Y Confino† A Shemer†‡ H Trau†‡ 《Journal of the European Academy of Dermatology and Venereology》2004,18(3):324-327
We report one patient with cardiofaciocutaneous (CFC) syndrome. He presented with clinical findings characteristic of this condition such as: cutaneous abnormalities, including ichthyosis, widespread keratosis pilaris, a peculiar craniofacial appearance with sparse, curly hair and low-set posteriorly rotated ears; congenital heart defects; and mild mental and motor retardation. We submit a comprehensive review of previously published articles regarding the dermatological findings in CFC syndrome (recently shown to be a variant of Noonan syndrome) emphasizing diagnostic criteria and its differentiation from the Costello syndrome. 相似文献
996.
Frontmatter 总被引:1,自引:0,他引:1
997.
998.
Claudia Brogsitter Thomas Grüning Reiner Weise Peter Wielepp Oliver Lindner Reiner K?rfer Wolfgang Burchert 《Journal of nuclear medicine》2005,46(1):19-24
(18)F-FDG PET is an important diagnostic tool for detecting myocardial viability in patients with coronary artery disease. In combination with perfusion scanning, (18)F-FDG PET allows differentiation between reversibly and irreversibly damaged myocardium and selection of patients likely to benefit from revascularization. Viability PET is usually performed in two-dimensional (2D) mode. Taking into account the rising number of three-dimensional (3D)-only scanners, a validation of 3D acquisition is required. METHODS: Twenty-one patients with coronary artery disease referred for (18)F-FDG PET underwent an imaging protocol of nongated 2D (2D-NG) and gated 2D (2D-G) acquisitions for 15 min each, followed by 3D gated acquisitions for 10 min (3D-10) and 5 min (3D-5), using an ECAT Exact HR+ scanner. Results were analyzed using a 20-segment polar map in terms of activity concentration (Bq/mL), viability (50% uptake threshold), regional activity distribution, visual assessment of viability based on a 3-point rating scale, and left ventricular ejection fraction. RESULTS: Activity concentration measured in each segment with 2D-G, 3D-10, and 3D-5 showed a good linear correlation with 2D-NG. Quantitative viability assessment with 3D-5 gave a sensitivity of 84% and a specificity of 98%, compared with 2D-NG. No differences in regional activity distribution and visual viability assessment were found between the various protocols. Left ventricular ejection fractions obtained with 3D-10 and 3D-5 showed a good linear correlation with those measured with 2D-G. CONCLUSION: An ECG-gated 3D imaging protocol gave results comparable to those of 2D acquisition with regard to absolute and regional myocardial activity distribution, left ventricular function, and visual viability assessment. Sensitivity for viability assessment with a 50% uptake threshold was significantly less with 3D, but specificity was maintained. This protocol delivers a clinical performance nearly equivalent to that of 2D acquisition. 相似文献
999.
In-situ forming drug delivery systems are prepared by dissolving a drug and a biodegradable polymer (poly(D,L-lactide-co-glycolide), PLGA) in a biocompatible organic solvent (In-situ implant, ISI) or further emulsified into an external phase (oil or aqueous solution), resulting in oil-in-oil or oil-in-water emulsions (In-situ forming microparticles, ISM). The chemical stability of PLGA and the drug is a major concern. In this study, the stability of PLGA and leuprolide acetate in the in-situ forming systems and lyophilized sponges was investigated. The degradation of PLGA increased with increasing storage temperature and water content in the biocompatible solvents. A faster degradation occurred in polar protic solvents (2-pyrrolidone, PEG 400, triethyl citrate) than in polar aprotic solvents (N-methyl-2-pyrrolidone, DMSO, triacetin, ethyl acetate). The presence of leuprolide acetate significantly accelerated PLGA degradation, especially in solution state. PLGA was stable in oily suspensions at 4 degrees C and degraded only slightly faster than solid powder at 25 degrees C. No interaction between the oils and the PLGA was observed as indicated by an unchanged T(g) of approx. 47 degrees C. PLGA underwent a slight degradation at 4 degrees C after 150 days in water and saturated sodium chloride solution. The degradation was slower in saturated sodium chloride solution than in water at 25 degrees C. Residual acetic acid in lyophilized sponges facilitated the PLGA degradation in contrast to dioxane. Leuprolide acetate did not affect the PLGA stability negatively. However, lidocaine significantly enhanced the polymer degradation in the sponges. Finally, leuprolide acetate was chemically stable in the sponges, the oils and the polymer solutions in suspension state, but unstable (aggregation) when dissolved in the polymer solutions and stored at 25 degrees C and 40 degrees C. 相似文献
1000.