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   22313篇
  免费   2393篇
  国内免费   403篇
耳鼻咽喉   406篇
儿科学   1057篇
妇产科学   1148篇
基础医学   2188篇
口腔科学   243篇
临床医学   2249篇
内科学   3398篇
皮肤病学   186篇
神经病学   1063篇
特种医学   647篇
外国民族医学   3篇
外科学   1579篇
综合类   1549篇
现状与发展   2篇
预防医学   3248篇
眼科学   529篇
药学   2306篇
  13篇
中国医学   455篇
肿瘤学   2840篇
  2024年   226篇
  2023年   495篇
  2022年   849篇
  2021年   1120篇
  2020年   1079篇
  2019年   1060篇
  2018年   973篇
  2017年   944篇
  2016年   997篇
  2015年   973篇
  2014年   1494篇
  2013年   2031篇
  2012年   1208篇
  2011年   1289篇
  2010年   1028篇
  2009年   1002篇
  2008年   1022篇
  2007年   958篇
  2006年   825篇
  2005年   684篇
  2004年   562篇
  2003年   552篇
  2002年   385篇
  2001年   354篇
  2000年   253篇
  1999年   264篇
  1998年   227篇
  1997年   209篇
  1996年   158篇
  1995年   149篇
  1994年   136篇
  1993年   108篇
  1992年   119篇
  1991年   87篇
  1990年   96篇
  1989年   64篇
  1988年   66篇
  1987年   60篇
  1985年   80篇
  1984年   54篇
  1982年   51篇
  1981年   55篇
  1980年   63篇
  1979年   56篇
  1978年   69篇
  1977年   61篇
  1976年   133篇
  1975年   115篇
  1974年   79篇
  1973年   85篇
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
71.
72.
73.
74.
75.
We analyzed the role of maternal C677T mutation in methylenetetrahydrofolate reductase (MTHFR) gene on spina bifida development in newborns. A total of 115 mothers who had given birth to a spina bifida child (SB mothers) gave 10 mL of blood together with written informed consent. The genotype distribution of C677T mutation was assessed and compared with that of the 4517 control individuals. The prevalence of the homozygous genotype (TT) among SB mothers was not significantly different from that among the controls (odds ratio [OR] = 0.65; 95% confidence interval [CI] = 0.31–1.25; P = 0.182), suggesting that MTHFR 677TT genotype in Japan is not associated with spina bifida development in newborns. The T allele frequency was not increased in SB mothers (34.8%) as compared to that of the control individuals (38.2%). Further, the internationally reported association between the two groups was found to be similar in all 15 countries studied except the Netherlands, where the TT genotype was found to be a genetic risk factor for spina bifida. For the prevention of affected pregnancy every woman planning to conceive has to take folic acid supplements 400 μg a day and the government is asked to take action in implementing food fortification with folic acid in the near future. In conclusion, it is not necessary for Japanese women to undergo genetic screening C677T mutation of the MTHFR gene as a predictive marker for spina bifida prior to pregnancy, because the TT genotype is not a risk factor for having an affected infant.  相似文献   
76.
Objective. The Nordic Orofacial Test-Screening (NOT-S) was developed as a comprehensive method to assess orofacial function. Results from the screening protocol have been presented in 11 international publications to date. This study reviewed these publications in order to compile NOT-S screening data and create profiles of orofacial dysfunction that characterize various age groups and disorders. Materials and methods. NOT-S results of nine reports meeting the inclusion criteria were reviewed. Seven of these studies not only provided data on the mean and range of total NOT-S scores, but also on the most common domains of orofacial dysfunction (highest rate of individuals with dysfunction scores), allowing the construction of orofacial dysfunction profiles based on the prevalence of dysfunction in each domain of NOT-S. Results. The compiled data comprised 669 individuals, which included healthy control subjects (n = 333) and various patient groups (n = 336). All studies reported differences between individuals with diagnosed disorders and healthy control subjects. The NOT-S data could measure treatment effects and provided dysfunction profiles characterizing the patterns of orofacial dysfunction in various diagnoses. Conclusions. This review corroborates previous results that the NOT-S differentiates well between patients and healthy controls and can also show changes in individuals after treatment. NOT-S could be used as a standard instrument to assess orofacial dysfunction, evaluate the outcomes of oral habilitation and rehabilitation and improve comparability in clinical practice and research.  相似文献   
77.
78.
目的比较筛查新生儿苯丙酮尿症(PKU)的2种检测苯丙氨酸(Phe)的方法——细菌抑制法(B IA)和荧光法。方法参加美国疾病控制中心(CDC)质量评价,分析B IA和荧光法的批内、批间误差及相对偏差,比较2种方法的结果。结果用CDC质控品测得BIA批内变异系数(CV)为14.29%,荧光法为5.85%;用不同浓度质控品测得B IA批间CV分别为25.34%、20.86%、34.78%和25.72%,荧光法为16.46%、13.22%、19.53%和15.41%;B IA的PKU阳性检出率为5.04/10万,荧光法为7.79/10万。结论荧光法较B IA具有更灵敏、准确、可定量、费时少的优点,国内今后应顺应其发展趋势,普及推广运用荧光法筛查新生儿PKU。  相似文献   
79.
Summary. Thirty patients (17 with restrictive, eight with chronic obstructive pulmonary disease and five with combined pulmonary changes) were studied. Ordinary pulmonary function tests were made and in addition the transfer factor (diffusion capacity) was measured at rest and compared to the arterial oxygen tension at rest and during maximal exercise. There was a significant correlation (r = 0–89) between the transfer factor at rest and the oxygen tension during maximal exercise in both the patients with restrictive and those with obstructive lung disease, but no correlation was found between the transfer factor and the resting oxygen tension. Exercise induced hypoxaemia (Po2< 8-8-5 kPa) occurred in some patients and this could be predicted with an excellent sensitivity and specificity if a discrimination point for the transfer factor of 50 per cent of predicted or less was chosen. Determination of the transfer factor at rest is thus a good screening test for exertional hypoxaemia and can be used to select patients for exercise testing when the purpose is to detect hypoxaemia.  相似文献   
80.
Ample evidence indicates that moderate regular exercise is beneficial for both normal individuals and patients with cardiovascular (CV) disease. However, intense and strenuous exercise in individuals with evident or occult underlying CV abnormalities may have adverse effects with provocation and exacerbation of arrhythmias that may lead to life‐threatening situations. Both of these aspects of exercise‐induced effects are herein reviewed.  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