全文获取类型
收费全文 | 519篇 |
免费 | 32篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 15篇 |
妇产科学 | 7篇 |
基础医学 | 97篇 |
口腔科学 | 12篇 |
临床医学 | 34篇 |
内科学 | 94篇 |
皮肤病学 | 24篇 |
神经病学 | 42篇 |
特种医学 | 7篇 |
外科学 | 28篇 |
综合类 | 1篇 |
预防医学 | 94篇 |
眼科学 | 8篇 |
药学 | 50篇 |
中国医学 | 2篇 |
肿瘤学 | 29篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 14篇 |
2016年 | 19篇 |
2015年 | 19篇 |
2014年 | 25篇 |
2013年 | 25篇 |
2012年 | 38篇 |
2011年 | 48篇 |
2010年 | 24篇 |
2009年 | 13篇 |
2008年 | 33篇 |
2007年 | 48篇 |
2006年 | 34篇 |
2005年 | 30篇 |
2004年 | 37篇 |
2003年 | 30篇 |
2002年 | 24篇 |
2001年 | 5篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1968年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有551条查询结果,搜索用时 15 毫秒
21.
Eldar-Geva T Zylber-Haran E Babayof R Halevy-Shalem T Ben-Chetrit A Tsafrir A Varshaver I Brooks B Margalioth EJ 《Reproductive biomedicine online》2007,14(2):148-154
The pregnancy rates after triggering of final oocyte maturation with gonadotrophin-releasing hormone (GnRH) agonist in GnRH-antagonist ovarian stimulation protocols are lower than those following triggering with human chorionic gonadotrophin (HCG). Furthermore, lower pregnancy rates following GnRH-antagonist protocols compared with long GnRH-agonist protocols have been reported. The differences might be due to an impact on oocyte number and quality or on the endometrium. If any stimulation protocol had a negative impact on oocyte quality, then further evidence of this effect would be observed following frozen-thawed embryo transfer originating from that stimulation cycle. The outcome of frozen-thawed embryo transfer was retrospectively analysed using the long protocol with triptorelin depot 3.75 mg (n = 215) or 0.1 mg/day (n = 83), or GnRH-antagonist protocol with either HCG (n = 69) or GnRH-agonist (n = 25) for final oocyte maturation. The outcomes measured were implantation rate, clinical pregnancy rate, ongoing pregnancy rate and embryo survival rate. All outcomes were similar in the four groups. It is concluded that the potential for frozen-thawed embryos to implant and develop following transfer is independent of the GnRH-analogue and the final oocyte maturation protocol used in the collection cycle. Lower IVF embryo transfer success using GnRH-antagonist/GnRH-agonist protocol does not appear to be related to an adverse effect on oocyte quality. 相似文献
22.
23.
Edit Roxana Moldovan Carlos Concheso Doria Jos Luis Ocaa Liana Sanda Baltes Elena Manuela Stanciu Catalin Croitoru Alexandru Pascu Ionut Claudiu Roata Mircea Horia Tierean 《Materials》2022,15(8)
Due to its wide applicability in industry, devising microstructures on the surface of materials can be easily implemented and automated in technological processes. Laser Surface Texturing (LST) is applied to modify the chemical composition, morphology, and roughness of surfaces (wettability), cleaning (remove contaminants), reducing internal stresses of metals (hardening, tempering), surface energy (polymers, metals), increasing the adhesion (hybrid joining, bioengineering) and decreasing the growth of pathogenic bacteria (bioengineering). This paper is a continuation and extension of our previous studies in laser-assisted texturing of surfaces. Three different patterns (crater array-type C, two ellipses at 90° overlapping with its mirror-type B and 3 concentric octagons-type A) were applied with a nanosecond pulsed laser (active medium Nd: Fiber Diode-pumped) on the surface of a ferritic stainless steel (AISI 430). Micro texturing the surface of a material can modify its wettability behavior. A hydrophobic surface (contact angle greater than 90°) was obtained with different variations depending on the parameters. The analysis performed in this research (surface roughness, wettability) is critical for assessing the surface functionality, characteristics and properties of the stainless steel surface after the LST process. The values of the surface roughness and the contact angle are directly proportional to the number of repetitions and inversely proportional to the speed. Recommendations for the use of different texturing pattern designs are also made. 相似文献
24.
25.
26.
Nagy ZZ Palágyi-Deak I Kovács A Kelemen E Förster W 《Journal of refractive surgery (Thorofare, N.J. : 1995)》2002,18(5):S620-S623
PURPOSE: To compare the results of traditional laser photoablation and wavefront-supported customized ablation (WASCA) in hyperopic photorefractive keratectomy (H-PRK). METHODS: This was a prospective study, comparing two treatment groups, each comprising 40 eyes of 20 patients. Wavefront aberrations were examined using a Shack-Hartmann aberrometer. Preoperative refraction was similar in the two groups; in the traditional H-PRK group (Group 1) it was +3.10 +/- 0.85 D, and in the WASCA-guided group (Group 2) it was +2.90 +/- 0.80 D. H-PRK was performed with the Asclepion-Meditec MEL 70 flying-spot excimer laser. The follow-up time was 6 months. RESULTS: In Group 1, mean postoperative refraction was +0.14 +/- 0.24 D, and in Group 2, -0.10 +/- 0.25 D; mean uncorrected visual acuity was 0.92 +/- 0.16 in Group 1 and 0.95 +/- 0.18 in Group 2. Mean best spectacle-corrected visual acuity was 0.96 +/- 0.04 in Group 1 and 1.06 +/- 0.13 in Group 2. In Group 1, 67.5% (27 of 40 eyes), and in Group 2, 85% (34 of 40 eyes) were within +/-0.50 D of target refraction. Regarding change of spectacle-corrected visual acuity in Group 1, 5% (2 of 40 eyes), and in Group 2, 20% (8 of 40 eyes) gained one Snellen line compared to the preoperative; in Group 1, 10% (4 of 40 eyes), and in Group 2, 12.5% (5 of 40 eyes) lost two Snellen lines. In Group 2, the root mean square value for the higher order aberration increased from the initial 0.134 to 0.257 microm at 6 months after surgery. CONCLUSIONS: WASCA-guided hyperopic-PRK treatment was found to be safe and predictable. The results were better than those achieved with traditional PRK performed using the same flying-spot type excimer laser. 相似文献
27.
The importance of antibiotic consumption and bacterial resistance analysis is unquestionable. Although the WHO has been recommending the use of ATC/DDD method for the analysis of drug utilization for about 20 years, only limited numbers of publications are available considering the antibiotic consumption of in-patients. In the present study--with the help of the mentioned method--we analysed the utilization of antibiotics in 5 clinical departments. We also investigated the connection between antibiotic consumption, bacterial resistance and enterococcal sepsis at the haematologic department. We could follow the successful impact of the implementation of the new guideline. 相似文献
28.
Balogh Z Wolfárd A Szalay L Orosz E Simonka JA Boros M 《The Journal of trauma》2002,52(6):1062-9; discussion 1070
BACKGROUND: Ischemia/reperfusion-induced polymorphonuclear neutrophil leukocyte (PMN) adhesion and extravasation are pivotal for the development of postinjury multiple organ failure. We hypothesized that the deleterious microcirculatory consequences of hemorrhagic shock (HS) could be altered by low-molecular-weight heparin (LMWH) therapy. Our aim was to investigate the effects of dalteparin sodium on leukocyte-endothelial cell interactions when LMWH treatment was initiated before HS or during resuscitation. METHODS: Anesthetized dogs underwent HS (40 mm Hg mean arterial pressure for 60 minutes) and resuscitation either with shed blood or with lactated Ringer's (LR) solution. LMWH or conventional heparin sodium pretreatment was administered subcutaneously before hemorrhage; or LMWH was given intravenously during resuscitation. Mesenteric postcapillary venules were observed by intravital video microscopy before and after HS, and 60 minutes, 120 minutes, and 180 minutes after resuscitation, and leukocyte rolling and firm adherence were determined. RESULTS: HS significantly increased PMN rolling and adhesion in the mesenteric microcirculation. LMWH, but not heparin sodium pretreatment, significantly inhibited both primary and secondary interactions. LMWH treatment was also effective when initiated during resuscitation. LMWH exerted the same inhibitory effect regardless of the type of resuscitation. CONCLUSION: LMWH treatment during resuscitation effectively inhibits PMN rolling and adhesion. 相似文献
29.
Simon E Péter M Benkó K Horkay E Erdélyi G Péter M Szúcs-Farkas Z Tóth J Kovács I Fülöp B 《Orvosi hetilap》2002,143(14):721-723
INTRODUCTION: The screening mammography decreases the mortality of female breast cancer. METHODS: A complex, independent centre of screening mammography has been operating in Debrecen since 1999. RESULTS: The number of the examinations were 10,399 in 1999 and 13,800 in 2000. The number of explored breast cancer cases were 43 (0.41%) in 1999 and 62 (0.45%) in 2000. CONCLUSION: Although the mortality reduction can be exactly measured after several years, we are convinced that the chances for a better life of these 107 women operated on with breast cancer in early state increased thanks to our project. The results of the breast cancer screening program in Debrecen fulfilled the professional requirements of mammographic service-screening. 相似文献
30.