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   146121篇
  免费   14339篇
  国内免费   8534篇
耳鼻咽喉   1118篇
儿科学   1834篇
妇产科学   1625篇
基础医学   21710篇
口腔科学   2581篇
临床医学   17849篇
内科学   20040篇
皮肤病学   1619篇
神经病学   7065篇
特种医学   5026篇
外国民族医学   69篇
外科学   13885篇
综合类   24144篇
现状与发展   30篇
一般理论   12篇
预防医学   10056篇
眼科学   3526篇
药学   17020篇
  134篇
中国医学   8149篇
肿瘤学   11502篇
  2024年   504篇
  2023年   2076篇
  2022年   5252篇
  2021年   7454篇
  2020年   5474篇
  2019年   4829篇
  2018年   5068篇
  2017年   4708篇
  2016年   4415篇
  2015年   6496篇
  2014年   8064篇
  2013年   7811篇
  2012年   10917篇
  2011年   11546篇
  2010年   8171篇
  2009年   6573篇
  2008年   7886篇
  2007年   7912篇
  2006年   7220篇
  2005年   6487篇
  2004年   5051篇
  2003年   4919篇
  2002年   4204篇
  2001年   3477篇
  2000年   3000篇
  1999年   2669篇
  1998年   1676篇
  1997年   1796篇
  1996年   1267篇
  1995年   1204篇
  1994年   1091篇
  1993年   767篇
  1992年   970篇
  1991年   890篇
  1990年   793篇
  1989年   727篇
  1988年   651篇
  1987年   554篇
  1986年   524篇
  1985年   424篇
  1984年   369篇
  1983年   302篇
  1982年   268篇
  1981年   229篇
  1980年   196篇
  1979年   199篇
  1978年   192篇
  1977年   211篇
  1976年   191篇
  1974年   156篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Erosive pustular dermatosis of the scalp (EPDS) is an uncommon chronic inflammatory response to scalp trauma that usually resolves with cicatricial alopecia. It most commonly affects elderly patients with a history of actinic damage. Herein, we describe a 16‐year‐old girl with acrofacial dysostosis type 1 presenting after surgery with crusting purulent scalp lesions, whose clinical presentation and histopathologic findings were consistent with EPDS. A review of the literature on EPDS in children is also detailed.  相似文献   
22.
23.
24.
Vegetation water content (VWC) is the key input parameter for a soil moisture retrieval algorithm based on microwave remote sensing, and VWC uncertainty can limit the estimated accuracy of soil moisture. There has been little research on VWC algorithm development and validation in China, and the uncertainty of the VWC estimation method has not been well evaluated. Therefore, the aim of this study is to evaluate the uncertainty of the VWC estimation method used in the SMAP (Soil Moisture Active Passive) algorithm on three spatial scales (the point-scale, 30 m scale, and 1 km scale) for maize in northeast China. Results from three ground experimental datasets showed that the SMAP VWC estimation method was strongly biased with an average overestimation of 1.16 kg m?2,1.04 kg m?2, and 1.13 kg m?2 for the point-scale, 30 m scale, and 1 km scale respectively, and maximum bias occurred in the mid-stage of maize. Also, a new power relationship between NDVI (Normalized Difference Vegetation Index) and VWC was proposed for the 30 m scale based on Sentinel 2 NDVI and field VWC values from 2017 experiment, with respective R2 (coefficient of determination) and Root Mean Squared Error (RMSE) values of 0.80 and 0.67 kg m?2. The results confirmed that this power relationship was still suitable for VWC estimation at the 1 km scale, and it has smaller bias than the original SMAP VWC method. Future work will be carried out to evaluate the applicability of this VWC estimation method over a lager region. It is expected that it can improve the accuracy of soil moisture by providing high precision VWC input parameters.  相似文献   
25.
26.
目的探讨腹腔镜经腹腹膜前疝修补术(TAPP)放置腹膜前引流对术后血肿及血清肿的影响。 方法选取2016年6月至2018年5月,江苏省苏州市中西医结合医院收治的单侧腹股沟疝患者90例,随机分为试验组和对照组,2组患者均行TAPP手术。试验组放置腹膜前引流管,对照组不放置引流管。收集2组患者的一般资料、手术相关资料及随访资料进行统计学分析,对比2组患者术后血肿及血清肿发生率差异。 结果全部患者均完成手术及随访。2组患者的一般资料、疝位置、疝分型、手术时间、住院花费、术后住院时间差异无统计学意义(P>0.05)。2组患者的术后发热发生率、急性疼痛发生率差异无统计学意义(P>0.05)。试验组术后血肿发生率明显低于对照组(P<0.05),试验组患者术后1和3个月血清肿发生率明显低于对照组,差异有统计学意义(P<0.05)。2组患者1年随访均观察到1例复发的病例,差异无统计学意义(P>0.05);随访期内2组患者均未出现感染的病例。 结论TAPP中,放置腹膜前引流管能够有效降低患者术后血肿和血清肿的发生率,同时并不增加感染和复发风险。  相似文献   
27.
Pharmaceutical Chemistry Journal - Three extracts were produced from the above-ground part of the meadowsweet Filipendula ulmaria (L.) Maxim. using water, 40% ethanol, and 70% ethanol. Comparative...  相似文献   
28.
Abstract

Objective

The sex, age, medical history, treatment, tobacco use, race risk (SAMe-TT2R2) Score; the sex, age, medical history, treatment, tobacco use, genotype combination (SAMe-TT2G2) Score; and the so-called modified SAMe-TT2R2 scores have been proposed to predict the anticoagulation quality for patients with non-valvular atrial fibrillation (NVAF). The data from a prospective controlled study is used to validate the SAMe-TT2R2 and SAMe-TT2G2 scores in Chinese NVAF patients treated with warfarin and to evaluate the association of factors with time in therapeutic range (TTR) to predict the quality of oral anticoagulation control.  相似文献   
29.
European Archives of Oto-Rhino-Laryngology - Several polymorphisms in a disintegrin and metalloproteinase 33 (ADAM33) have been implicated in susceptibility to allergic rhinitis (AR), but the...  相似文献   
30.
BACKGROUNDGuillain-Barré syndrome (GBS) is a rare disorder that typically presents with ascending weakness, pain, paraesthesias, and numbness, which mimic the findings in lumbar spinal stenosis. Here, we report a case of severe lumbar spinal stenosis combined with GBS.CASE SUMMARYA 70-year-old man with a history of lumbar spinal stenosis presented to our emergency department with severe lower back pain and lower extremity numbness. Magnetic resonance imaging confirmed the diagnosis of severe lumbar spinal stenosis. However, his symptoms did not improve postoperatively and he developed dysphagia and upper extremity numbness. An electromyogram was performed. Based on his symptoms, physical examination, and electromyogram, he was diagnosed with GBS. After 5 d of intravenous immunoglobulin (0.4 g/kg/d for 5 d) therapy, he gained 4/5 of strength in his upper and lower extremities and denied paraesthesias. He had regained 5/5 of strength in his extremities when he was discharged and had no symptoms during follow-up.CONCLUSIONGBS should be considered in the differential diagnosis of spinal disorder, even though magnetic resonance imaging shows severe lumbar spinal stenosis. This case highlights the importance of a careful diagnosis when a patient has a history of a disease and comes to the hospital with the same or similar symptoms.  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