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   1356篇
  免费   81篇
  国内免费   7篇
耳鼻咽喉   3篇
儿科学   45篇
妇产科学   59篇
基础医学   162篇
口腔科学   23篇
临床医学   131篇
内科学   294篇
皮肤病学   16篇
神经病学   94篇
特种医学   18篇
外科学   142篇
综合类   29篇
一般理论   2篇
预防医学   219篇
眼科学   21篇
药学   98篇
中国医学   8篇
肿瘤学   80篇
  2024年   1篇
  2023年   19篇
  2022年   71篇
  2021年   69篇
  2020年   33篇
  2019年   56篇
  2018年   62篇
  2017年   42篇
  2016年   38篇
  2015年   49篇
  2014年   53篇
  2013年   72篇
  2012年   118篇
  2011年   114篇
  2010年   68篇
  2009年   51篇
  2008年   75篇
  2007年   85篇
  2006年   76篇
  2005年   66篇
  2004年   54篇
  2003年   58篇
  2002年   31篇
  2001年   15篇
  2000年   9篇
  1999年   6篇
  1998年   2篇
  1997年   5篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   4篇
  1991年   3篇
  1990年   6篇
  1989年   7篇
  1988年   4篇
  1987年   2篇
  1986年   3篇
  1985年   2篇
  1983年   1篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1974年   1篇
  1973年   1篇
  1964年   1篇
  1963年   1篇
排序方式: 共有1444条查询结果,搜索用时 15 毫秒
61.
62.
Autosomal dominant cerulean cataracts (ADCC) have previously been mapped to two loci: one on chromosome 17q24 and the other on chromosome 22q11.2-q12.2, which includes the beta-B2 crystallin (CRYBB2) candidate gene. Using polymorphic markers in these regions (D17S802, D17S836, D17S1806 and CRYBB2, D22S258) for linkage analysis, we excluded these loci in a large Moroccan family presenting with an unusual form of ADCC with early onset of lens opacities and rapid evolution. This finding confirms the clinical and genetic heterogeneity of autosomal dominant congenital cerulean cataracts.  相似文献   
63.
BACKGROUND: The clinical presentation of tinea is usually, but not always, characteristic. The purpose of this study was to determine whether the routine use of the periodic acid-Schiff (PAS) stain in inflammatory skin disorders is requisite for identifying clinically undiagnosed tinea cases and to ascertain whether there are histopathologic clues that suggest the diagnosis of a dermatophyte infection. METHODS: Hematoxylin and eosin (H&E)-stained slides from 60 PAS-positive tinea cases were examined histologically by two observers. One observer, aware of the diagnosis of tinea, searched for hyphal elements and also recorded in detail epidermal, dermal, and follicular changes. The second observer, not aware of the diagnosis beforehand, reviewed the same slides, together with randomly mixed slides from 21 non-tinea cases, recording the same parameters as the first reviewer. RESULTS: Of the 60 cases of tinea, only 45% were diagnosed clinically. Histologic examination of H&E sections by the two observers disclosed the presence of hyphal elements in 68 and 45%, respectively. No significant histologic differences, except for the presence of hyphae, were observed between tinea and non-tinea cases. CONCLUSIONS: The finding that only 57% of PAS-positive cases of tinea showed hyphal elements on H&E examination alone, together with no other differentiable histologic characteristics, lends strong support for the routine use of PAS-staining for inflammatory skin disorders.  相似文献   
64.
Erosive oral lichen planus (EOLP) is uncommon. We present nine cases of EOLP in patients aged from 39 to 77 years. The aim of our retrospective study was to determine the clinical particularities and the treatment difficulties of this disease.  相似文献   
65.
Soy-based formulae and infant growth and development: a review   总被引:3,自引:0,他引:3  
Soy-based infant formulae, initially developed for infants who were lactose intolerant or allergic to cow's milk-based formulae, now account for >25% of the infant formulae sold in the United States. Formulations have changed over the years to improve digestibility, the stability and availability of minerals, and protein quality. Recent concerns have been raised regarding the phytoestrogenic isoflavone content of soy-based formulae. A systematic review of the literature was conducted to evaluate various measures of infant health and development in clinical studies comparing modern soy-based formulae with other diets and to document areas in which further research seems warranted. Results suggest that modern soy-based formulae support normal growth and nutritional status in healthy term infants in y 1 of life. However, there are very limited data on sexual and reproductive development or outcomes such as immune function, visual acuity/cognitive development and thyroid function. Available data do not provide evidence of meaningful differences in timing of maturation, sexual development or fertility in adolescents or adults. Nonetheless, given evidence suggesting that early exposure to soy and/or isoflavones might have long-term effects, further research following infants fed soy-based formulae into adulthood is warranted.  相似文献   
66.
Otosclerosis is a hereditary disease frequently encountered in Caucasian populations (0.1 to 2% prevalence). In Tunisia, prevalence varies from 0.4% to 0.8%. The presence of a genetic factor associated with hormonal, biochemical or environmental factors, probably lead to variable expression of the otosclerosis according to age and sex. Mean age at onset of disease is 25 years (range 16-35 year) for 61.5% of affected women. In men this proportion is 50.2%. The incidence of otosclerosis is high in the 26-35 year age group. Our study showed that in northeastern areas of Tunisia, women in this age group were affected twice as often as men in this age group. This probably suggests that an endocrine mechanism is involved in disease etiology. However, in northwestern areas, there was no significant difference between the rates of otosclerosis between sexes. Geographical distribution of affected subjects according to the ethnic origin of their parents showed that the areas with the highest concentration of affected individuals were urban or seaside areas such as the gouvernorate of Nabeul. The frequency of otosclerosis was lower in rural areas and/or areas far from the seaside.  相似文献   
67.
The purpose of this study is to investigate the association between maternal alcohol intake in pregnancy and the occurrence of early stillbirth using a retrospective cohort analysis of singleton births in Missouri that occurred in the period 1989 through 1997 (N=655,979). We used Cox proportional hazards regression to generate adjusted risk estimates for total, early, and late stillbirth associated with maternal alcohol intake and used the Robust Sandwich Estimator to adjust for intracluster correlations among sibships. Overall, a total of 3,508 counts of stillbirth were identified, yielding a stillbirth rate of 5.3 per 1,000. Among mothers who consumed alcohol during pregnancy, the stillbirth rate was 8.3 per 1,000. Mothers who consumed alcohol while pregnant were 40% more likely to experience stillbirth as compared with nondrinking mothers (adjusted hazards ratio=1.4, 95% confidence interval: 1.2-1.7). A dose-response relationship was evident; mothers who consumed five or more drinks per week during pregnancy experienced a 70% elevated risk of stillbirth compared with nondrinking mothers (adjusted hazards ratio=1.7; 95% confidence interval: 1.0-3.0). The risk of early stillbirth was 80% higher among drinking mothers compared with abstainers (adjusted hazards ratio=1.8; 95% confidence interval: 1.3-2.3). The elevated risks for both early and late stillbirth did not reach statistical significance when broken down by level of alcohol intake. In conclusion, maternal drinking during pregnancy is associated with an increased risk of early stillbirth. These findings underscore the need to reinforce current counseling strategies toward pregnant women and women who intend to conceive on the detrimental effects of alcohol use in pregnancy.  相似文献   
68.
Abstract: Focal dermal hypoplasia is a rare, X-linked dominant syndrome characterized by dysplasla of the skin, skeleton, and central nervous system. We report an intant who was born with severe focal dermal hypoplasla and an epigastric hernia. Operative timing and approach to abdominal wall defects in the presence of severe cutaneous dysplasia are discussed.  相似文献   
69.
Primary teratomas of the fallopian tube are extremely uncommon. To date, only about 50 cases have been reported in the literature. They occur usually in the fourth decade. There association with nulliparity and reduced parity has been noted. Many have been discovered incidentally and none has been diagnosed preoperatively. The majority are cystic, show great variation in size and are commonly located in the ampulla or the isthmus. They can be intraluminal, attached to the serous surface by a pedicule and rarely intramural. Histologically they are similar to teratoma of the ovary and elsewhere. We describe a mature cystic teratoma of the fallopian tube found incidentally in a 35-year-old woman operated for suspicion of ectopic tubal pregnancy. The feature of benign teratoma of the fallopian tube is discussed.  相似文献   
70.
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