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   622篇
  免费   21篇
耳鼻咽喉   3篇
儿科学   123篇
妇产科学   24篇
基础医学   64篇
临床医学   61篇
内科学   110篇
皮肤病学   10篇
神经病学   95篇
特种医学   25篇
外科学   61篇
预防医学   15篇
眼科学   5篇
药学   18篇
肿瘤学   29篇
  2022年   5篇
  2021年   10篇
  2019年   18篇
  2018年   13篇
  2017年   6篇
  2016年   8篇
  2015年   7篇
  2014年   11篇
  2013年   13篇
  2012年   28篇
  2011年   23篇
  2010年   18篇
  2009年   11篇
  2008年   24篇
  2007年   23篇
  2006年   21篇
  2005年   25篇
  2004年   16篇
  2003年   20篇
  2002年   34篇
  2001年   23篇
  2000年   27篇
  1999年   26篇
  1998年   9篇
  1997年   8篇
  1996年   6篇
  1995年   11篇
  1994年   6篇
  1993年   8篇
  1992年   18篇
  1991年   10篇
  1990年   10篇
  1989年   12篇
  1988年   11篇
  1987年   13篇
  1986年   7篇
  1985年   6篇
  1984年   10篇
  1983年   7篇
  1981年   4篇
  1979年   7篇
  1978年   4篇
  1977年   8篇
  1974年   4篇
  1972年   8篇
  1970年   4篇
  1969年   8篇
  1968年   4篇
  1967年   5篇
  1966年   4篇
排序方式: 共有643条查询结果,搜索用时 11 毫秒
71.
72.
73.
74.
75.
Anemia in premature infants can be prevented by prophylactic treatment with recombinant human erythroprotein (r-huEPO). r-HuEPO as been used for a long time in patients with end-stage renal failure. The main factor which can limit r-HuEPO efficiency is limited iron bioavailability. Adapted iron supplementation is needed when preterm infants receive r-HuEPO in order to avoid the depletion of iron stores. Oral iron supplementation is simple but indigestibility is frequent. Furthermore, the intestinal absorption and utilization of oral iron is limited. Parenteral iron supplementation is possible in infants who are very pre-term as they are parenterally fed during the first weeks of life. There are various preparations of intravenous iron with different physicochemical properties. Toxicity and side-effects of parenteral iron preparations depend on these properties. Two parenteral iron preparations are available in France: iron-saccharate (Venofer) and iron-dextrin (Maltofer). Iron delivery and possible side-effects of these preparations are different and need to be considered before use in preterm infants.  相似文献   
76.
77.
The ideal timing and nature of surgical reconstruction in individuals with Disorders of Sex Development (DSD) is highly controversial. Despite the increasing number of publications on this topic, evidence-based recommendations still cannot be made. However it is generally accepted that optimal care for DSD requires an experienced multidisciplinary team. This means that surgical decisions are now made within the context of a multidisciplinary team and all members of the team – and not just specialist surgeons – may be called upon to discuss choices for surgery with patients and parents. To do this well, every clinician in the team should have an understanding of the range of techniques available for genital surgery, the risks and benefits of procedures and the controversies surrounding timing of surgery.The aim of this paper is to give an overview of the variety of surgical procedures in current use and in what situation a particular technique would be indicated. The short-term risks and benefits are described and where available long-term outcome data is discussed. To date, discussions surrounding genital surgery have been led primarily by surgeons. Some non-surgical clinicians have expressed unease about decision making in genital surgery but have felt ill equipped to comment on an area with which they are unfamiliar. This review gives a detailed explanation of current surgical practice offered in a specialized center for DSD and such information should facilitate a more balanced discussion.  相似文献   
78.
79.
Hair analysis for the major metabolite of cocaine, benzoylecgonine (BZE) was performed in a cohort of 251 predominantly African-American newborns utilizing a modified radioimmunoassay (RIA) (Abuscreen Roche Laboratories, Nutley, N.J., USA). Maternal drug intake was confirmed by positive urine drug screen for cocaine metabolites at the time of delivery. The BZE concentrations reported here are the composites of both the parent compound cocaine (hydrolyzed to BZE) and the native BZE metabolized by the patient and deposited in the hair follicle. Hair analysis as an indicator for gestational cocaine exposure had a sensitivity of 88%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 85%. The range of BZE was 99-23,300 ng/g of hair, with 79% having hair BZE levels <5,000 ng/g of hair. The BZE RIA was confirmed by gas chromatography and mass spectrometry (GC/MS). Of the 18 mother/infant pairs tested, the hair BZE ratio (maternal to neonatal) varied from 0.5 to 8.9 in 13 pairs. In spite of maternal high hair BZE levels, 5 newborns had no evidence of hair BZE, stressing the importance of the placental role for the cocaine transfer to the fetus. After controlling for gestational age, higher BZE levels significantly correlated with smaller head circumference (p < 0.03) and birth weight (p < 0.01).  相似文献   
80.
Summary. Leucine-rich repeats are conserved structural motifs present in the four components of the human platelet glycoprotein Ib/IX/V complex receptor for the adhesive protein von Willebrand factor. The absence or abnormality of this complex is responsible for Bernard-Soulier disease, an autosomal recessive bleeding disorder. We report a deletion of leucine 179, located in a highly conserved position of the seventh leucine-rich repeat of GPIbα, found in a variant form of Bernard-Soulier disease (Bernard-Soulier Nancy I). Three affected siblings of a family were characterized by absence of ristocetin-induced platelet agglutination, although ADP aggregation was normal. Flow cytometry studies showed detectable amounts of all four members of the GPIb/IX/V complex on the surface of the patients' platelets. Western blotting revealed normal levels of GPIX, decreased levels of GPIbβ and GPV, and <1% of GPIbα. RT-PCR studies showed the presence of mRNA coding for GPIbα. GPIbβ, GPIX and GPV. Sequencing showed a three-base deletion which results in the absence of a leucine residue, highly conserved across the seven leucine-rich repeats of GPIbα and also within the other members of the leucine-rich glycoprotein family. The absence of the leucine 179 in a patient's GPIbα is believed to cause a conformational change in the protein which would account for the lack of binding of most of the MoAbs tested and would be responsible for the absence of von Willebrand factor binding. These results point to the leucine-rich region of GPIbα as being required for the correct exposure of the von Willebrand binding site as well as for the correct assembly and stability of the GPIb IX V complex on the platelet surface.  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