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   5846篇
  免费   528篇
  国内免费   94篇
耳鼻咽喉   66篇
儿科学   50篇
妇产科学   120篇
基础医学   690篇
口腔科学   184篇
临床医学   538篇
内科学   704篇
皮肤病学   129篇
神经病学   323篇
特种医学   80篇
外国民族医学   1篇
外科学   1393篇
综合类   447篇
预防医学   773篇
眼科学   34篇
药学   592篇
  4篇
中国医学   80篇
肿瘤学   260篇
  2024年   14篇
  2023年   158篇
  2022年   214篇
  2021年   228篇
  2020年   247篇
  2019年   285篇
  2018年   251篇
  2017年   249篇
  2016年   217篇
  2015年   253篇
  2014年   431篇
  2013年   456篇
  2012年   320篇
  2011年   325篇
  2010年   266篇
  2009年   231篇
  2008年   225篇
  2007年   210篇
  2006年   187篇
  2005年   196篇
  2004年   156篇
  2003年   141篇
  2002年   126篇
  2001年   101篇
  2000年   97篇
  1999年   83篇
  1998年   97篇
  1997年   88篇
  1996年   62篇
  1995年   77篇
  1994年   51篇
  1993年   42篇
  1992年   39篇
  1991年   32篇
  1990年   33篇
  1989年   32篇
  1988年   33篇
  1987年   36篇
  1986年   43篇
  1985年   34篇
  1984年   22篇
  1983年   13篇
  1982年   16篇
  1981年   17篇
  1980年   9篇
  1979年   9篇
  1978年   6篇
  1977年   5篇
  1974年   2篇
  1972年   2篇
排序方式: 共有6468条查询结果,搜索用时 15 毫秒
31.
32.
目的 统计某医院外科病人手术部位感染发生率,找出导致术后感染的相关因素,对外科病人发生术后感染的机率进行科学预测。方法 研究对象选取2012—2015年某三甲教学医院术后病人,发生275例手术部位感染的病人为病例组,另按照1∶1比例选取术后无感染266例病人为对照组,进行病例回顾性调查研究,统计检出致病菌和手术感染部位情况,探讨手术部位感染综合因素,结合术后感染统计分析数据构建人工网络模型。结果 手术部位感染率0.35%。多因素分析结果表明,手术部位感染的独立危险因素分别是手术类型、是否有原发疾病、切口类别、ASA病情分级、病人年龄、手术时长、手术例次(OR=11.043,9.587,2.136,1.818,1.299, 1.293,1.041,P<0.05)。最终确定网络模型运行结果如下,平均误差为0.040%,网络错分率 0.038% ;通过曲线下面积(ROC)大于0.9。结论 部位感染危险因素前三位是手术类型、是否患有原发疾病、切口类别。人工网络模型针对手术部位感染危险度的预测结果较理想,建立与其相关预报信息平台系统,为临床院感管控决策提供指导依据。  相似文献   
33.
一氧化氮与阻塞性黄疸肾功能障碍关系的实验研究   总被引:2,自引:1,他引:2  
目的: 研究一氧化氮(N0)与阻塞性黄疸(OJ)肾功能障碍的关系. 方法: 雄性SD大鼠胆总管结扎后随机分成5 d、10 d及15 d三组(B1组、B2组、B3组),同时建立对应的假手术对照组.观察肾功能的变化,同时测定血和肾组织N0水平及一氧化氮合酶(NOS)活性,并用图像分析检测NOS-mRNA于肾脏表达的部位和量的变化. 结果: B1、B2及B3各组的血及肾组织NO含量分别是(43.72±10.61)μm01/L,(0.515±0.082)μmol/g@pro;(34.44±9.63)μmol/L,(0.375±0.096)μmoL/g@pro;(27.34±8.88)μmol/L,(0.251±0.086)μmol/g@pro.血及肾组织NO与内生肌酐清除率(Ccr)、肾皮质血流(RCBF)呈正相关.肾组织iNOSmRNA表达增加,血和肾组织NOS活性降低. 结论: 血和肾组织NO水平下降,是导致OJ时肾功能损伤的原因之一,体内NO水平的持续下降是由于NOS活性降低而非NOS基因表达减少.  相似文献   
34.
视频喉镜是能够提供上呼吸道间接视野的新型气管插管设备。在困难气道管理处理方面.与直接喉镜相比.视频喉镜能够改善声门显露的Cormack—Lehane分级,并能在较短时间内达到相同或更高的气管插管成功率。尽管视频喉镜可获得非常好的声门显露.但是应用视频喉镜时插入和推进气管导管有时可发生失败。到目前为止,尚无确切证据表明在正常或困难气道患者视频喉镜应取代直接喉镜。  相似文献   
35.
36.
Skin is the most commonly used tissue for the transplantation. A meticulous care of the donor site is needed to prevent scarring, delayed healing, and pain. Various agents and dressing materials have been reported to help healing of skin graft donor sites. Sucralfate is an extensively used agent, which provides acute gastroprotection and acceleration of chronic ulcer healing. In this study, we assessed the effects of topical sucralfate on the healing of the split thickness skin graft donor sites in a prospective comparative way. The study was carried out on 32 randomly chosen patients undergoing surgery for various causes and requiring split thickness skin graft resurfacing. The upper halves of the skin graft donor sites on the thighs were simply covered with paraffin gauze and the lower half was covered with sucralfate-soaked paraffin gauzes. The day of full epithelization varied from 6 to 9 days and 8–12 days on the sucralfate-applied areas and on the control sites, respectively. The mean value of the healing was 7.01 days in the studied lower halves and 10.8 days in the upper halves. The healing rate was strikingly faster and less painful on the sucralfate-applied areas. We were able to discharge patients earlier than usual, and patients’ comfort increased. It seems that sucralfate is a promising topical agent to increase the healing rate and decrease the incidence of associated problems such as pain and hypertrophic scar.  相似文献   
37.
38.
The ovariectomized (OVX) rat is widely used in osteoporosis research, but no standard model exists. The individual effects of rat age, skeletal site, and time post‐ovariectomy (post‐OVX) on bone have been examined. However, the relationship between them is not yet fully explored. This study examined how various combinations of rat age, skeletal site, and time post‐OVX affect bone mineral and microarchitecture. The rats used were 12 (n = 28), 24 (n = 28), and 44 (n = 31) weeks old. In each age group, approximately half underwent OVX and other half underwent Sham surgeries. Bone mineral (content and density) and trabecular morphology was assessed at 2, 5, 10, 15, 20, 25, and 30 weeks post‐surgery. Sites examined included the proximal tibia, spine, distal femur, and proximal femur. Overall, the proximal tibia showed the earliest and greatest differences between OVX and Sham groups. The 24‐week‐old group showed the best osteoporotic response. The 12‐week‐old group showed growth effects, whilst the 44‐week‐old group showed aging effects. The response of certain sites to OVX was also found to depend on the rat age used. These findings may aid in explaining discrepancies reported in the literature as well as synergistic combinations that may signify advanced conditions. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:189–196, 2011  相似文献   
39.

Introduction

Quantitative assessment of scars is needed in clinical practice and in scientific studies. To date, there have been no entirely objective methods available for these purposes. We introduce a new method developed for scar assessment combining standardized digital imaging (SDI) and spectral modelling (SpM). With this method, the estimated concentration changes (ECCs) of haemoglobin and melanin in the scar can be determined quantitatively.

Patient and methods

: In the current study, 22 skin graft donor site (SGDS) wounds were treated with two alternative dressing materials, Suprathel® and Mepilex Transfer®, side by side on the same wound. The SGSD scars were assessed using SDI and SpM. The scars were given subjective ratings by three surgeons using the POSAS and the Vancouver Scar Scale (VSS). The correlations between the ECCs of melanin and haemoglobin and the corresponding subjective ratings were calculated as well as the Intraclass Correlation Coefficient (ICC) of the subjective ratings.

Results

There was a statistically significant correlation between the ECCs of melanin and haemoglobin and the subjective ratings. A single observer could reliably assess pigmentation with the POSAS scale (ICC = 0.75) but not vascularity (ICC = 0.51). The reliability ratings of the VSS were unacceptably low.

Conclusions

The ECC values of haemoglobin and melanin give accurate documentation of the scar status. The results also show that the subjective ratings in this study were unreliable especially when interfering pigmentation and increased vascularity were both present at the same time.  相似文献   
40.
目的探讨胎盘部位滋养细胞肿瘤(PSTT)保留生育功能治疗的方法并分析其结局。方法对1999年1月至2008年10月在本院行保留生育功能治疗的5例PSTT进行回顾性分析。结果3例病理大体类型为结节息肉型,行诊刮加联合化疗有效;2例肿块型行开腹子宫病灶切除术加联合化疗有效。平均随诊47.2个月,均完全缓解(CR)无复发,月经均恢复正常。1例已成功妊娠,现宫内孕6月余。结论PSTT患者年龄〈35岁,有保留生育功能的要求,病变局限于子宫,除外子宫多发病灶(病理除外弥漫浸润型),病理未显示不良预后因素者可试行保留生育功能的治疗。  相似文献   
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