首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   45777篇
  免费   2715篇
  国内免费   66篇
耳鼻咽喉   737篇
儿科学   2073篇
妇产科学   1142篇
基础医学   5312篇
口腔科学   2278篇
临床医学   4042篇
内科学   9465篇
皮肤病学   1279篇
神经病学   3700篇
特种医学   1419篇
外国民族医学   1篇
外科学   7284篇
综合类   237篇
一般理论   21篇
预防医学   2888篇
眼科学   1177篇
药学   2926篇
中国医学   182篇
肿瘤学   2395篇
  2024年   51篇
  2023年   431篇
  2022年   322篇
  2021年   936篇
  2020年   609篇
  2019年   950篇
  2018年   1604篇
  2017年   1141篇
  2016年   1232篇
  2015年   1088篇
  2014年   1264篇
  2013年   2108篇
  2012年   3242篇
  2011年   3861篇
  2010年   1784篇
  2009年   1052篇
  2008年   3174篇
  2007年   3407篇
  2006年   3308篇
  2005年   3300篇
  2004年   3103篇
  2003年   2885篇
  2002年   2724篇
  2001年   883篇
  2000年   998篇
  1999年   595篇
  1998年   279篇
  1997年   254篇
  1996年   206篇
  1995年   172篇
  1994年   172篇
  1993年   137篇
  1992年   108篇
  1991年   89篇
  1990年   96篇
  1989年   82篇
  1988年   75篇
  1987年   60篇
  1986年   61篇
  1985年   59篇
  1984年   68篇
  1983年   52篇
  1982年   64篇
  1981年   56篇
  1980年   56篇
  1979年   42篇
  1978年   39篇
  1977年   51篇
  1976年   29篇
  1973年   24篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.

Introduction and hypothesis

The purpose of this study was to investigate the success and complication rates of single-incision sling for treating stress urinary incontinence (SUI), with a 3-year follow-up.

Methods

This study comprised 173 female patients with SUI or mixed urinary incontinence (MUI) with dominant SUI who underwent minisling procedure. All patients had positive cough stress test preoperatively; they were followed up for 3 years after surgery (1, 3, 6, 12 months, and yearly).

Results

Total follow-up was 36 months, and mean age 51 years (44–77); 128 (74 %) patients presented SUI and 45 (26 %) MUI. Objective and subjective cure and failure rates were 83.8 % (145 cases), 6.4 % (11 cases), and 9.8 % (17 cases), respectively. There were no differences in cure rates between 1 and 3 years. Mean body mass index was 28.7 (26.1–35.2), and mean operating time 7.9 min. (6.5–11.9). There were no major intraoperative complications. Eleven patients (6.4 %) had de novo urge incontinence that resolved using anticholinergic drugs; no patient had urinary retention. Vaginal mesh extrusion was reported in nine (5.2 %) patients.

Conclusions

The minisling system attained high success rates at 3 years’ follow-up. The procedure was easy to learn and has lower complication rate.
  相似文献   
992.
The present study aimed to assess the effects of low-level laser therapy (GaAlAs) on the bone repair process within titanium scaffolds in the femurs of healthy and osteoporotic rats. Fifty-six rats were divided into four groups: group Sh: SHAM animals that received scaffolds; group LSh: SHAM animals that received scaffolds and were subjected to laser therapy; group OV: ovarietomized (OVX) animals that received scaffolds; and group LOV: OVX animals that received scaffolds and were subjected to laser therapy. Thirty days following ovariectomy or sham surgery, scaffolds were implanted in the left femurs of all animals in the study. Immediately after opening the surgical site, the inner part of the surgical cavity was stimulated with low-level laser (GaAlAs). In addition to this procedure, the laser group was also subjected to sessions of low-level laser therapy (LLLT) at 48-h intervals, with the first session performed immediately after surgery. The rats were sacrificed at 2 and 6 weeks, time in which femur fragments were submitted for histological and histomorphometric examination, and skin tissue above the scaffold was submitted to histological analysis. At the end of the study, greater bone formation was observed in the animals submitted to LLLT. At 2 and 6 weeks, statistically significant differences were observed between LSh and Sh groups (p?=?0.009 and 0.0001) and LOV and OV (p?=?0.0001 and 0.0001), respectively. No statistical difference was observed when assessing the estrogen variable. On the basis of our methodology and results, we conclude that LLLT improves and accelerates bone repair within titanium scaffolds in both ovariectomized and healthy rats, when compared to animals not subjected to radiation.  相似文献   
993.
UltraSeal XT® hydro? is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro? as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro? was applied to each group of teeth (n?=?10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50 °C with a dwell time of 30 s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p?>?0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p?<?0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro? essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface.  相似文献   
994.
To evaluate the effect of irradiation with light-emitting diode (LED; 455 nm) on the viability and synthesis of dentin matrix proteins by odontoblast-like cells, MDPC-23 cells were cultivated (104 cells/cm2) in 24-well culture plates. After 12 h incubation in Dulbecco’s modified Eagle’s medium (DMEM), the cells were submitted to nutritional restriction by means of reducing the concentration of fetal bovine serum (FBS) for an additional 12 h. Cells were irradiated one single time with one of the following energy densities (EDs): 0.5, 2, 4, 10, or 15 J/cm2 and irradiance fixed at 20 mW/cm2. Non-irradiated cells served as control. After 72 h, cells were evaluated with regard to viability (methylthiazol tetrazolium technique (MTT)), mineralization nodule (MN) formation, total protein (TP) production, alkaline phosphatase activity (ALP), and collagen synthesis (Sircol), n?=?8. The data were submitted to Kruskal–Wallis and Mann–Whitney tests (p?>?0.05). There was no statistical difference between the viability of cells irradiated or not (control), for all the EDs. However, an increase in TP was observed for all the EDs when compared with the control group. A reduced ALP activity was seen in all irradiated groups, except for the ED of 0.5 J/cm2, which did not differ from the control. There was no difference between the irradiated groups and control regarding collagen synthesis, with the exception of the ED of 10 J/cm2, which inhibited this cell function. Significant reduction in MN occurred only for the EDs of 0.5 and 2 J/cm2. The single irradiation with blue LED (455 nm), irradiance of 20 mW/cm2, and energy densities ranging from 0.5 to 15 J/cm2 exerted no effective biostimulatory capacity on odontoblast-like cells.  相似文献   
995.
The aim of this study was to investigate whether retinal vasculature changes had occurred (retinal artery diameter, retinal vein diameter and artery/vein ratio) in patients with varicocele. This pilot study included 50 healthy subjects with any eye disease apart from slight refractive errors and 55 patients with varicocele. Retinal arteriolar and venular diameters were measured and summarised as central retinal arteriolar equivalent (CRAE) and central retinal venular equivalent (CRVE). Retinal microvascular diameters and the arteriolar–to‐venular ratio (AVR) were assessed with a digital retinal camera. All measurements and calculations were performed using a computer‐based program. The mean CRAE value was 151.8 ± 3.6 μm in the study group and 150.4 ± 4.5 μm in the control group. Mean CRVE value was 209.4 ± 5.9 μm in the study group and 200.1 ± 8.7 μm in the control group. AVR was found 0.72 ± 0.02 in the study group and 0.75 ± 0.03 in the control group. There were significant differences between groups in terms of CRVE and AVR. There were no significant differences between groups in terms of CRAE. The results of this study showed that the patients with varicocele showed significant changes on retinal vascular diameter.  相似文献   
996.
997.
998.
999.
1000.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号