全文获取类型
收费全文 | 20274篇 |
免费 | 3301篇 |
国内免费 | 329篇 |
专业分类
耳鼻咽喉 | 818篇 |
儿科学 | 390篇 |
妇产科学 | 342篇 |
基础医学 | 1731篇 |
口腔科学 | 533篇 |
临床医学 | 2377篇 |
内科学 | 4405篇 |
皮肤病学 | 884篇 |
神经病学 | 1781篇 |
特种医学 | 1040篇 |
外科学 | 4543篇 |
综合类 | 78篇 |
现状与发展 | 2篇 |
一般理论 | 3篇 |
预防医学 | 1167篇 |
眼科学 | 559篇 |
药学 | 939篇 |
中国医学 | 144篇 |
肿瘤学 | 2168篇 |
出版年
2024年 | 106篇 |
2023年 | 587篇 |
2022年 | 375篇 |
2021年 | 706篇 |
2020年 | 878篇 |
2019年 | 473篇 |
2018年 | 952篇 |
2017年 | 855篇 |
2016年 | 1153篇 |
2015年 | 1150篇 |
2014年 | 1479篇 |
2013年 | 1603篇 |
2012年 | 1218篇 |
2011年 | 1062篇 |
2010年 | 1103篇 |
2009年 | 1236篇 |
2008年 | 889篇 |
2007年 | 713篇 |
2006年 | 763篇 |
2005年 | 628篇 |
2004年 | 496篇 |
2003年 | 418篇 |
2002年 | 340篇 |
2001年 | 431篇 |
2000年 | 324篇 |
1999年 | 324篇 |
1998年 | 323篇 |
1997年 | 322篇 |
1996年 | 357篇 |
1995年 | 335篇 |
1994年 | 215篇 |
1993年 | 159篇 |
1992年 | 199篇 |
1991年 | 182篇 |
1990年 | 109篇 |
1989年 | 161篇 |
1988年 | 135篇 |
1987年 | 108篇 |
1986年 | 111篇 |
1985年 | 109篇 |
1984年 | 95篇 |
1983年 | 78篇 |
1982年 | 76篇 |
1981年 | 55篇 |
1980年 | 59篇 |
1979年 | 37篇 |
1978年 | 50篇 |
1977年 | 49篇 |
1976年 | 38篇 |
1975年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
Jin Hwan Ahn Joon Ho Wang Jae Chul Yoo Sung Kon Kim Jung Ho Park Jong Woong Park 《Knee surgery, sports traumatology, arthroscopy》2006,14(12):1288-1291
This article describes a modified suture technique designed for the vertical repair of the anterior horn of the meniscus after arthroscopic decompression of a large meniscal cyst. This procedure comprises of three steps: first, the meniscus was pierced vertically using a suture hook and a No. 0 PDS suture. Second, both ends of the No. 0 PDS on the femoral and tibial surfaces of the meniscus were pulled to the outside of the joint capsule using a spinal needle preloaded with suture material. Finally, a skin incision was made adjacent to the suture materials, and both ends were tied. We recommend this technique not only for the vertical repair of the anterior horn of the meniscus after decompression of large meniscal cyst, but also to repair a longitudinal tear of the meniscus. 相似文献
4.
5.
6.
Michael C. Dalsing MD Melissa Kevorkian BS Beth Raper BA Craig Nixon MS Stephen G. Lalka MD Dolores F. Cikrit MD Joseph L. Unthank PhD Malcolm B. Herring MD 《Annals of vascular surgery》1989,3(2):127-133
This study evaluates the potential for endothelial seeding of a collagen-impregnated Dacron graft with or without surface modifiers (fibronectin, heparin) to attach and retain these cells during flow. Human umbilical endothelial cells were harvested, cultured, labeled with Indium111-oxine and seeded onto 30 mm X 4 mm diameter grafts. Six graft surfaces were studied: 1) a collagen-impregnated Dacron graft, HemashieldR (C); 2) C + fibronectin (C + F); 3) C + heparin (C + H); 4) C + F + H; 5) HytrelR + F (Hyt + F); and 6) Hyt + F + H. Radioactive loss determined the percentage attachment and then percentage retention of labeled inoculum after a one-hour in vitro perfusion. Scanning electron and light microscopy demonstrated the endothelium on the graft surface following perfusion. Fibronectin-coated grafts had a significantly higher percentage attachment than those without fibronectin (ANOVA, P less than 0.05). However, the percentage retention following perfusion was similar for all Dacron grafts and statistically inferior to the HytrelR grafts studied (ANOVA, P less than 0.05). SEM evaluation of the C + F + H graft surface was qualitatively the most impressive Dacron surface for seeding, yet was inferior to the HytrelR graft. We conclude that fibronectin benefits the initial attachment of endothelium to collagen-coated Dacron rivaling the HytrelR surface. Fibronectin does not improve percentage retention of the HemashieldR surface during perfusion, therefore, some of its initial benefit is lost. 相似文献
7.
Kenneth K. H. Chao BS Eric Cheung BS William B. Armstrong MD Brian J. F. Wong MD 《Otolaryngology--head and neck surgery》2002,126(6):593
Objective: The study goal was to compare the laser spot size created using reflective and refractive micromanipulators with a CO2 laser and to determine the sensitivity of spot size to laser power. Study Design and Setting: A CO2 laser and operating microscope (400-mm focal length) was coupled to either a reflective (Cassegrain-like) or refractive micromanipulator. Laser spot size was determined by measuring the region of ablation created by laser irradiation of wood (dry tongue depressors), exposed photographic film, and agar gel using optical micrometry. Laser power varied from 0.5 to 20 W with pulse durations of 0.1 and 0.5 second. Results: The reflective micromanipulator demonstrated overall smaller spot sizes for a given laser power and lower incremental change in spot size with increasing power. The reflective design demonstrated less sensitivity to increases in laser power. Conclusions: Micromanipulator optical design can result in significant differences in laser spot size. The reflective device used in this study demonstrated less sensitivity to increasing laser power. (Otolaryngol Head Neck Surg 2002;126:593-597.) 相似文献
8.
Cheung-Yeoul Park Su-Gwan Kim Myung-Duck Kim Tae-Gwan Eom Jung-Hoon Yoon Sang-Gun Ahn 《Journal of oral and maxillofacial surgery》2005,63(10):1522-1527
OBJECTIVES: Dental lasers have been used for uncovering submerged implants as well as decontaminating implant surfaces when treating peri-implantitis. The objective of this study was to compare the possible alterations of the smooth surface and resorbable blast material (RBM) surface implants after using NdYAG and CO(2) lasers at various energies. MATERIALS AND METHODS: Ten smooth surface implants and 10 RBM surface implants were used. Two smooth surface implants and 2 RBM surface implants served as a control group that was not lased. The remaining implants were treated using NdYAG and CO(2) lasers. The surface of each implant was treated for 10 seconds on the second and third threads. The smooth surface implants (group 1) were treated using a pulsed contact NdYAG laser at power settings of 1, 2, 3.5, and 5 W, which are commonly used for soft tissue surgery; the corresponding energy and frequency were 50 mJ and 20 Hz, 100 mJ and 20 Hz, 350 mJ and 10 Hz, and 250 mJ and 20 Hz, respectively. The group 2 RBM implants were treated using a pulsed contact NdYAG laser. The group 3 smooth surface implants were treated using a pulsed wave non-contact CO(2) laser at 1, 2, 3.5, and 5 W, and the group 4 RBM implants were treated using a pulsed wave non-contact CO(2) laser. Data were analyzed using scanning electron microscopy. RESULTS: The control surface was very regular and smooth. After NdYAG laser treatment, the implant surface showed alterations of all the surfaces. The amount of damage was proportional to the power. A remarkable finding was the similarity of the lased areas on the smooth and RBM surfaces. CO(2) laser at power settings of 1.0 or 2.0 W did not alter the implant surface, regardless of implant type. At settings of 3.5 and 5 W, there was destruction of the micromachined groove and gas formation. CONCLUSION: This study supports that CO(2) laser treatment appears more useful than NdYAG laser treatment and CO(2) laser does not damage titanium implant surface, which should be of value when uncovering submerged implants and treating peri-implantitis. 相似文献
9.
10.