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   128187篇
  免费   5809篇
  国内免费   279篇
耳鼻咽喉   2026篇
儿科学   4005篇
妇产科学   2734篇
基础医学   17346篇
口腔科学   4547篇
临床医学   7840篇
内科学   31745篇
皮肤病学   4053篇
神经病学   10029篇
特种医学   2909篇
外国民族医学   1篇
外科学   15840篇
综合类   666篇
一般理论   36篇
预防医学   12709篇
眼科学   2865篇
药学   8802篇
中国医学   654篇
肿瘤学   5468篇
  2023年   801篇
  2022年   510篇
  2021年   2593篇
  2020年   1346篇
  2019年   2950篇
  2018年   5005篇
  2017年   2914篇
  2016年   2704篇
  2015年   3013篇
  2014年   3459篇
  2013年   5217篇
  2012年   9248篇
  2011年   9897篇
  2010年   4949篇
  2009年   3486篇
  2008年   7912篇
  2007年   8475篇
  2006年   7862篇
  2005年   7769篇
  2004年   6887篇
  2003年   6450篇
  2002年   6076篇
  2001年   3823篇
  2000年   4434篇
  1999年   3296篇
  1998年   505篇
  1997年   311篇
  1996年   307篇
  1995年   244篇
  1992年   1259篇
  1991年   1046篇
  1990年   929篇
  1989年   760篇
  1988年   634篇
  1987年   620篇
  1986年   614篇
  1985年   523篇
  1984年   386篇
  1983年   297篇
  1979年   330篇
  1978年   203篇
  1975年   266篇
  1974年   315篇
  1973年   349篇
  1972年   289篇
  1971年   310篇
  1970年   290篇
  1969年   292篇
  1968年   267篇
  1967年   236篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Clinical Oral Investigations - This overview analyzed the quality of the systematic reviews (SRs) available on treatments for molar-incisor hypomineralization (MIH). Six electronic databases were...  相似文献   
3.
4.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
5.
Clinical Oral Investigations - To determine the usefulness of Serum C-terminal telopeptide cross-link of type 1 collagen (sCTX) as a preoperative marker for predicting the risk of developing...  相似文献   
6.
Sleep and Breathing - There are no studies comparing tests performed at home with those carried out in the laboratory, using the same device. The only studies that have been performed...  相似文献   
7.
ObjectiveThe aim of this study was to create and validate an abbreviated version of the Spanish Transsexual Voice Questionnaire for Male-to-Female Transsexuals (SvTVQMtF).SettingThe study was conducted by two referral hospitals for voice feminization surgery and by a university department of psychology and speech therapy, all in Spain.Subjects and methodsWe prospectively studied 51 male-to-female transsexuals who underwent voice feminization surgery between January 2017 and December 2018. The SvTVQMtF was completed before and after surgery, and the 10 items with the greatest variation were selected by clinical consensus of an expert panel to develop the short version of the SvTVQMtF (SvTVQMtF-10). The correlation between the total score and the score for each item on the SvTVQMtF and the SvTVQMtF-10 was studied. The internal consistency of the SvTVQMtF-10 was analysed.ResultsGood correlation (Pearson coefficient above .90) was found between the two questionnaires. A significant correlation was found between the total SvTVQMtF-10 score and the score for each item. A significant negative correlation was found between the SvTVQMtF and fundamental frequency after voice feminization surgery. Cronbach's α was .79.ConclusionThe SvTVQMtF-10 is a valid short version of the SvTVQMtF and can be used to quantify voice-related quality of life in MtF transsexuals.  相似文献   
8.
9.
The CAV-AEP annually publishes the immunisation schedule considered optimal for all children and adolescent resident in Spain, taking into account the available evidence.The 2 + 1 schedule is recommended (2, 4, and 11 months) with hexavalent vaccines (DTPa-VPI-Hib-HB) and with 13-valent pneumococcal conjugate.A 6-year booster is recommended, preferably with DTPa (if available), with a dose of polio for those who received 2 + 1 schemes, as well as vaccination with Tdpa in adolescents and in each pregnancy, preferably between 27 and 32 weeks.Rotavirus vaccine should be systematic for all infants.Meningococcal B vaccine, with a 2 + 1 schedule, should be included in routine calendar.In addition to the inclusion of the conjugated tetravalent meningococcal vaccine (MenACWY) at 12 years of age with catch up to 18 years, inclusive, the CAV recommends this vaccine to be also included at 12 months of age, replacing MenC. Likewise, it is recommended in those over 6 weeks of age with risk factors or who travel to countries with a high incidence of these serogroups.Two-dose schedules for triple viral (12 months and 3-4 years) and varicella (15 months and 3-4 years) will be used. The second dose could be applied as a tetraviral vaccine.Universal systematic vaccination against HPV is recommended, regardless of gender, preferably at 12 years, and greater effort should be made to improve coverage. The 9 genotype extends coverage for both genders.  相似文献   
10.
Food-grade titanium dioxide (E171) is widely used as a food additive, and it is known that after oral consumption, E171 is translocated into the bloodstream reaching the highest titanium level at 6 h. E171 is accumulated in some organs triggering toxicity, but the effects on the blood parameters after oral consumption have been less studied. Recently, evidence shows that oral exposure to E171 induces behavioral signs of anxiety and depression. The relation between blood alterations and psychiatric disorders has been previously demonstrated. However, the oral exposure to E171 effects on alterations in blood parameters and effects linked to alterations in animal behavior has not been explored. In this short communication, we aimed to investigate the effects of E171 on specific blood parameters (hematocrit, hemoglobin, number of erythrocytes, and leukocytes) and anxiety and compulsive-like behavior in males and females orally exposed to ~5 mg/kg for 4 weeks. The results showed that E171 decreased hematocrit and hemoglobin in male but not in female mice while leukocyte and erythrocyte count remained unaltered. Oral consumption of E171 decreased the levels of anxiety-like behavior in females but not in male mice, while compulsive-like behavior was increased in both male and female mice.  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