全文获取类型
收费全文 | 8628篇 |
免费 | 599篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 289篇 |
儿科学 | 224篇 |
妇产科学 | 124篇 |
基础医学 | 1301篇 |
口腔科学 | 241篇 |
临床医学 | 652篇 |
内科学 | 1536篇 |
皮肤病学 | 60篇 |
神经病学 | 545篇 |
特种医学 | 284篇 |
外国民族医学 | 1篇 |
外科学 | 1664篇 |
综合类 | 65篇 |
一般理论 | 6篇 |
预防医学 | 587篇 |
眼科学 | 723篇 |
药学 | 402篇 |
中国医学 | 5篇 |
肿瘤学 | 557篇 |
出版年
2023年 | 97篇 |
2022年 | 128篇 |
2021年 | 263篇 |
2020年 | 162篇 |
2019年 | 258篇 |
2018年 | 251篇 |
2017年 | 202篇 |
2016年 | 213篇 |
2015年 | 205篇 |
2014年 | 311篇 |
2013年 | 375篇 |
2012年 | 527篇 |
2011年 | 480篇 |
2010年 | 307篇 |
2009年 | 274篇 |
2008年 | 438篇 |
2007年 | 461篇 |
2006年 | 405篇 |
2005年 | 394篇 |
2004年 | 359篇 |
2003年 | 336篇 |
2002年 | 343篇 |
2001年 | 187篇 |
2000年 | 178篇 |
1999年 | 154篇 |
1998年 | 82篇 |
1997年 | 54篇 |
1996年 | 61篇 |
1995年 | 61篇 |
1994年 | 58篇 |
1993年 | 46篇 |
1992年 | 93篇 |
1991年 | 96篇 |
1990年 | 84篇 |
1989年 | 77篇 |
1988年 | 87篇 |
1987年 | 81篇 |
1986年 | 64篇 |
1985年 | 78篇 |
1984年 | 54篇 |
1983年 | 41篇 |
1979年 | 38篇 |
1978年 | 35篇 |
1933年 | 31篇 |
1930年 | 34篇 |
1928年 | 33篇 |
1927年 | 33篇 |
1926年 | 34篇 |
1925年 | 41篇 |
1924年 | 37篇 |
排序方式: 共有9266条查询结果,搜索用时 15 毫秒
1.
2.
3.
Mariagrazia Marucci Gert Ragnarsson Anders Axelsson 《Journal of controlled release》2006,114(3):369-380
In this work, Electronic Speckle Pattern Interferometry (ESPI) is presented as a non-invasive tool to study drug transport in controlled release systems. ESPI is shown to be a feasible tool to measure drug film permeability via comparison with an ordinary diaphragm cell. A specially designed cuvette was used in the release study: the polymeric film separated the donor and the receiving chambers of the cuvette to create a diffusion cell with no mixing in the two chambers. Thus, the cuvette mimicked a coated system immersed in a stagnant bulk liquid. Concentration profile data were obtained for the two compartments. Using these data, it was possible to visually discriminate between a film subject only to diffusion and a film subject to diffusion as well as osmotic effects. Moreover, using the concentration profile data collected at different time intervals, it was possible to follow the film properties in terms of drug permeability, thus studying how drug permeability depended on drug concentration. Compared to other measuring techniques, ESPI offers the advantages that no invasive measurements are needed, and that no sampling and calibration are required. Furthermore, the permeability can be measured with no influence of mass transfer in the boundary layers. 相似文献
4.
5.
6.
Comparison of ThinPrep versus conventional smear cytopreparatory techniques for fine-needle aspiration specimens of head and neck masses. 总被引:2,自引:0,他引:2
Lloyd Ford Barry M Rasgon Raymond L Hilsinger Raul M Cruz Karen Axelsson Gregory J Rumore Thomas M Schmidtknecht Balaram Puligandla John Sawicki William Pshea 《Otolaryngology--head and neck surgery》2002,126(5):554-561
OBJECTIVES: Diagnostic accuracy of the ThinPrep process (Cytyc, Boxborough, MA) was compared with that of conventional (smear) cytopreparation for fine-needle aspiration (FNA) of head and neck masses. METHODS: In a prospective, randomized, single-blinded study, 209 patients served as their own controls and underwent 236 FNAs using ThinPrep and conventional (smear) cytopreparatory techniques. RESULTS: ThinPrep produced less air-drying artifact and less mechanical distortion than the conventional method. The conventional technique was diagnostic in 63% of samples; the ThinPrep technique was diagnostic in 55% of samples. When all results were combined, pathologists subjectively preferred the conventional technique but accepted use of ThinPrep as the only cytopreparatory technique for most head and neck masses. CONCLUSIONS: For adequately experienced cytopathologists, ThinPrep is acceptable for FNA of salivary masses, neck cysts, metastatic lymph nodes, and thyroid lesions. Conventional smear technique should be used for FNA of nonmetastatic lymphoid lesions. Use of ThinPrep can complement use of the conventional (smear) cytopreparatory technique when aspirate is nondiagnostic or bloody, when the patient has a blood-borne infectious disease, when the clinician is inexperienced, or when aspirate has entered the syringe. 相似文献
7.
Heung Bae Kim James J Pomposelli Craig W Lillehei Roger L Jenkins Maureen M Jonas Laura E Krawczuk Steven J Fishman 《Liver transplantation》2005,11(11):1389-1394
Extrahepatic portal vein thrombosis (EHPVT) may occur in children or adults and usually comes to clinical attention due to complications of portal hypertension such as variceal hemorrhage. A variety of standard surgical techniques exist to manage these patients, but when these fail surgical options are limited. We describe two novel portosystemic shunts that utilize the gonadal vein as an autologous conduit. Four patients were evaluated for EHPVT with variceal bleeding. None of the patients were candidates for a standard splenorenal shunt due to prior surgical procedures. The first patient underwent a left mesogonadal shunt and the remaining 3 patients underwent a right mesogonadal shunt. Postoperative ultrasound or computed tomography (CT) scan confirmed early patency of the shunt in each patient. There have been no further episodes of variceal hemorrhage with follow-up of 3.5 years in the child who underwent the left mesogonadal shunt, and 17, 19, and 20 months in the patients who underwent the right mesogonadal shunt. Three of the 4 shunts remain patent. One shunt thrombosis occurred in a patient homozygous for the Factor V Leiden mutation despite anticoagulation with coumadin. This is the first report of the successful use of the gonadal vein as an in situ conduit for constructing a portosystemic shunt. In conclusion, the right and left mesogonadal shunts may be useful as salvage operations for patients with EHPVT who have failed standard surgical shunt procedures. 相似文献
8.
Can carotid endarterectomy be justified? No 总被引:1,自引:0,他引:1
S Jonas 《Archives of neurology》1987,44(6):652-654
9.
Michael Hermansson Anders Ekedahl Jonas Ranstam Thomas Zilling 《BMC gastroenterology》2009,9(1):25-13
Background
Despite a decreasing incidence of peptic ulcer disease, most previous studies report a stabile incidence of ulcer complications. We wanted to investigate the incidence of peptic ulcer complications in Sweden before and after the introduction of the proton pump inhibitors (PPI) in 1988 and compare these data to the sales of non-steroid anti-inflammatory drugs (NSAID) and acetylsalicylic acid (ASA). 相似文献10.
Jenny Andersson Barbro Linderholm Jonas Bergh Goran Elmberger 《Applied immunohistochemistry & molecular morphology》2004,12(1):14-20
We have studied the intratumor HER-2/neu heterogeneity in 78 consecutive and population-based primary invasive breast carcinomas. Within the invasive component, heterogeneity was detected in only 1 of 78 tumors. In 48 tumors (62%), we found both in situ and invasive components in analyzed tissue sections. Twelve of these 48 tumors had a difference of at least 2 arbitrary units in the in situ compared with the invasive part of the tumor with regard to the HER-2/neu status analyzed by HercepTest (immunohistochemistry). Eight of these 12 tumors were reanalyzed with fluorescent in situ hybridization and immunohistochemistry with and without a new Automated Cellular Imaging System. In this limited material, immunohistochemistry in combination with the Automated Cellular Imaging System seemed to have a better correlation with fluorescent in situ hybridization than immunostaining analyzed manually. In conclusion, HER-2/neu expression is not seldom heterogeneous in invasive compared with in situ components within a tumor. This finding should be considered in the choice of evaluation method. To avoid heterogeneity as a confounding factor in HER-2/neu analyses, detection methods such as immunohistochemistry and fluorescent in situ hybridization, which can provide evaluation in a preserved tissue architecture, should be used. Perhaps the intratumor HER-2/neu heterogeneity can explain some of the unexpected failures of trastuzumab therapy. 相似文献