全文获取类型
收费全文 | 2307篇 |
免费 | 120篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 85篇 |
儿科学 | 130篇 |
妇产科学 | 213篇 |
基础医学 | 199篇 |
口腔科学 | 106篇 |
临床医学 | 180篇 |
内科学 | 379篇 |
皮肤病学 | 25篇 |
神经病学 | 129篇 |
特种医学 | 142篇 |
外科学 | 512篇 |
综合类 | 34篇 |
预防医学 | 39篇 |
眼科学 | 94篇 |
药学 | 76篇 |
肿瘤学 | 101篇 |
出版年
2024年 | 3篇 |
2023年 | 23篇 |
2022年 | 23篇 |
2021年 | 58篇 |
2020年 | 39篇 |
2019年 | 66篇 |
2018年 | 87篇 |
2017年 | 73篇 |
2016年 | 105篇 |
2015年 | 110篇 |
2014年 | 102篇 |
2013年 | 160篇 |
2012年 | 192篇 |
2011年 | 189篇 |
2010年 | 105篇 |
2009年 | 101篇 |
2008年 | 172篇 |
2007年 | 197篇 |
2006年 | 159篇 |
2005年 | 157篇 |
2004年 | 90篇 |
2003年 | 76篇 |
2002年 | 49篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 18篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 1篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1978年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有2444条查询结果,搜索用时 26 毫秒
1.
Targeting in a cellular level is still one of the major challenges in biomedical treatments. However, new synthetic and analytical techniques now allow the development of precisely prepared macromolecules. Thus, glycopolymer chains are reported to be prepared with controlled length, monomer sequences, as well as chain‐folded structures. A high level of complexity in synthetic macromolecules also allows increased selectivity in targeting, which is a key factor in biomedical applications. 相似文献
2.
BACKGROUND: Posterior spinal procedures through tubular exposures have been described. However, tubes restrain visibility and require co-axial instrument manipulation, increasing difficulty and potentially compromising surgical results. An independent-blade retractor system overcomes the obstacles of working through a tube and has been used to perform minimally-disruptive decompression and instrumented tranforaminal lumbar interbody fusion (TLIF). PURPOSE: To evaluate the advantages to patient recovery and surgical efficacy of this technique. METHODS/RESULTS: Retrospective review of technique employing a minimally-disruptive approach to decompression and transforaminal lumber interbody fusion (TLIF). CONCLUSIONS: Minimally-disruptive decompression and instrumented TLIF can be performed in a safe and effective manner using an independent-blade retractor system. Relative to traditional-open techniques, surgical goals can be accomplished, but with the benefits of minimally-disruptive surgery. 相似文献
3.
4.
C.T.-guided stereotactic destructive pain procedures; percutaneous cordotomy, trigeminal tractotomy-nucleotomy and extralemniscal myelotomy are presented. All procedures were applied in 32 cases without any mispuncture or complication. Advantages of C.T. guidance are direct visualization of target electrode relations, measurements of spinal cord diameters at the lesion site, and demonstration of spinal cord displacement during the procedure. 相似文献
5.
Feza Karakayali Nihan Haberal Hale Tufan Nesrin Hasirci Ozgur Basaran Sinasi Sevmis Aydin Akdur Aysel Kiziltay Mehmet Haberal 《Journal of investigative surgery》2007,20(3):167-173
Tranilast is an antiallergic drug that interferes with proliferation and migration of vascular smooth muscle cell induced by platelet-derived growth factor (PDGF) and transforming growth factor-beta1 (TGF-beta1). We investigated the local effect of tranilast on neointimal hyperplasia using tranilast-coated prosthetic grafts. The inner sides of the thin-walled polytetrafluoroethylene (PTFE) grafts were coated with chitosan and tranilast containing chitosan solution. Wistar albino rats (32) were used in the study. Patches (1 x 2 mm) for vascular grafts were prepared. Three groups were tested: group 1 (n = 12; tranilast coated), group 2 (n = 10; adhesive-only film-layer-coated), and group 3 (n = 10; normal ePTFE patch grafts sutured to the carotid arteries of the rats). Recipient sites of the carotid arteries were excised 4 weeks after surgery. All sections were examined histologically for graft patency, thrombus formation, and neointimal thickness. Expression of PDGF, fibroblast growth factor, and TGF-beta1 on cross-sections of the neointima were evaluated by immunohistochemistry. No significant differences were found regarding mean neointimal thicknesses. PDGF and TGF-beta-1 expressions were significantly lower in group 1. Although a decrease in local effect of tranilast was observed for growth factor expressions at a drug concentration of 0.05 mg/cm(2), a significant reduction in neointimal hyperplasia was not achieved. The coating concentration of 0.05 mg/cm(2) may have been too low to produce an antiproliferative effect. Given our promising results, further studies are recommended and planned using different drug concentrations and time intervals. 相似文献
6.
7.
This study aimed to evaluate human antibody responses to diphtheria toxin subunits in various age groups. Antibodies against the intact diphtheria toxin and the diphtheria toxin subunits A and B were evaluated in 1319 individuals using a double-antigen ELISA. Although high levels of protection (83.6%, 95% CI 79.2-87.4) were found in children and adolescents, the middle-aged adult population was less protected (28.8%, 95% CI 24.3-33.6). An increase in age was associated with a decrease in the frequency of protected individuals in the 0-39-year age group (p <0.001). Anti-subunit B levels correlated well (p <0.01) with levels of antibodies against the intact toxin. In children aged < or =16 years, the intervals at which the peaks in geometric mean titres of anti-subunit B antibodies were observed were found to correlate with the ages at which booster doses are administered. Overall, males appeared to be more protected than females (OR 1.67, 95% CI 1.34-2.08, p <0.001). A small group of individuals had antibody levels of > or =0.1 IU/mL against the intact toxin, but did not have protective antibody against subunit B. Determination of anti-subunit B antibody levels should help in evaluating the effectiveness of diphtheria boosters and other aspects of diphtheria immunity. 相似文献
8.
Purpose: to determine wheather an association exists between sensorineural hearing loss and pseudoexfoliation. Methods: Hearing thresholds were determined by using pure-tone au-diometry in 75 patients with pseudoexfoliation syndrome and in the control group of 75 subjects without pseudoexfoliation The groups were sex and age matched. Results: The frequency of 相似文献
9.
Mete Isikoglu Kemal Ozgur Sergio Oehninger Sebahat Ozdem Murat Seleker 《Gynecological endocrinology》2006,22(5):256-260
BACKGROUND: We aimed to determine whether serum concentrations of anti-Müllerian hormone (AMH) can be used as a tool for prediction of the efficacy of sperm retrieval. METHODS: This was a prospective cohort observational study. AMH levels were determined in 47 men presenting for infertility evaluation. Group 1 consisted of 24 infertile patients diagnosed with non-obstructive azoospermia. Group 1 was further divided into two subgroups. The patients with spermatozoa in their testicular samples constituted group 1a (n = 13), while the patients with absence of spermatozoa constituted group 1b (n = 11). Twenty-three normozoospermic fertile men constituted group 2. Serum AMH was measured before obtaining testicular specimens. RESULTS: Testicular spermatozoa were recovered in 13 out of the 24 patients (54%). Demographic characteristics of the three groups were similar. The difference between serum AMH levels among the three groups did not reach statistical significance. CONCLUSIONS: We speculated that although AMH is secreted predominantly into the seminiferous tubules, studying serum samples might be more advantageous than seminal plasma because the presence of seminal proteases could influence AMH levels in the latter. However, our results did not demonstrate differences in serum concentrations of AMH between the studied groups. Studies with extended patient populations focusing on seminal plasma concentrations of AMH are warranted. 相似文献
10.
Gursel Dursun Ozan Bagis Ozgursoy Ozgur Kemal Isil Coruh 《European archives of oto-rhino-laryngology》2007,264(9):1027-1032
The purpose of this study was to present our experience with combined use of CO2 laser and cold instrumentation for Reinke’s edema surgery and to evaluate 1-year follow-up results of the technique in a
series of professional voice users. Fifteen patients with Reinke’s edema who underwent microlaryngoscopic surgery were included.
Videolaryngostroboscopy, perceptual and acoustic voice analyses were performed before and after surgery. During the 1-year
follow-up, no recurrence of Reinke’s edema was encountered. Significant postoperative improvement was obtained in the quality
of voice, in terms of GRBAS scores, Fo, jitter, shimmer and NHR. No evidence of laryngeal cancer was found on the histological
examinations. Combined use of CO2 laser and cold instrumentation provides a reliable and safe method for Reinke’s edema surgery, and cessation of smoking,
voice rest and control of the laryngopharyngeal reflux contribute to the success of surgery. We consider that the removal
of redundant mucosa of the vocal fold reduces the risk of the recurrence of Reinke’s edema and provides better quality of
voice. However, it does not imply that our method is superior to others’, but this procedure constitutes an effective treatment
of choice for Reinke’s edema patients, including professional voice users. 相似文献