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   141篇
  免费   12篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   3篇
  2016年   5篇
  2015年   5篇
  2014年   5篇
  2013年   6篇
  2012年   15篇
  2011年   11篇
  2010年   11篇
  2009年   9篇
  2008年   10篇
  2007年   10篇
  2006年   8篇
  2005年   10篇
  2004年   5篇
  2003年   9篇
  2002年   9篇
  1999年   1篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1987年   1篇
  1981年   1篇
  1980年   1篇
  1977年   3篇
  1974年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有153条查询结果,搜索用时 16 毫秒
141.
Recently we described an unbiased bacterial whole-genome immunoinformatic analysis aimed at selection of potential CTL epitopes located in “hotspots” of predicted MHC-I binders. Applying this approach to the proteome of the facultative intra-cellular pathogen Francisella tularensis resulted in identification of 170 novel CTL epitopes, several of which were shown to elicit highly robust T cell responses. Here we demonstrate that by DNA immunization using a short DNA fragment expressing six of the most prominent identified CTL epitopes a potent and specific CD8+ T cell responses is being induced, to all encoded epitopes, a response not observed in control mice immunized with the DNA vector alone Moreover, this CTL-specific mediated immune response prevented disease development, allowed for a rapid clearance of the bacterial infection and provided complete protection against lethal challenge (10LD50) with F. tularensis holarctica Live Vaccine Strain (LVS) (a total to 30 of 30 immunized mice survived the challenge while all control DNA vector immunized mice succumbed). Furthermore, and in accordance with these results, CD8 deficient mice could not be protected from lethal challenge after immunization with the CTL-polyepitope. Vaccination with the DNA poly-epitope construct could even protect mice (8/10) against the more demanding pulmonary lethal challenge of LVS. Our approach provides a proof-of-principle for selecting and generating a multi-epitpoe CD8 T cell-stimulating vaccine against a model intracellular bacterium.  相似文献   
142.
143.
Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by a multitude of low density lipoprotein receptor (LDL-R) mutations. The purpose of the current investigation was to define the spectrum of mutations causing FH in Israel and determine their relative distribution among diverse origin groups. A total of 193 FH families were recruited in Israel, 54 of them through the MED PED (Make Early Diagnosis Prevent Early Death) FH program. Molecular analysis of the LDL-R using single-strand conformation polymorphism (SSCP) or denaturing gradient gel electrophoresis (DGGE) or both has been completed in 95 index cases. This analysis resulted in the identification of 15 LDL receptor mutations, including 7 novel mutations (del 197, C308G, R385W, splice junction mutation of intron 14, del 328, del 502–505, stop 10, del 165), that were present in 49 index cases (52%). The 15 mutations are mapped to three known functional domains of the receptor (7 in the LDL-binding region, 7 in the epidermal growth factor precursor homology region and 1 in the membrane-spanning region). Screening for the identified mutations in the remaining 98 index cases enabled the molecular diagnosis of 31 additional cases. It is therefore concluded that 80 out of 193 index cases (41%) harbor 1 of the 15 mutations described here. Three mutations – del197 (FH-Lithuania), D147H (FH-Sephardic), and stop660 (Lebanese allele) – were found in a total of 66 index cases (34%); these may be regarded as founder mutations in the three respective origin groups. In conclusion, in Israel molecular heterogeneity at the LDL receptor gene locus reflects the ethnic distribution of its origin groups. The results of the present investigation provide valuable diagnostic tools for a subset of the Israeli patients with FH who are at high risk for atherosclerosis and its complications. Received: 1 February 1996 / Revised: 22 May 1996  相似文献   
144.
Maintaining pregnancy to term is important as preterm delivery is a risk factor for impaired infant development, which may have negative long-term consequences. Therefore, developing biomarkers that can predict pregnancy longevity during early gestation is essential for the prevention of preterm birth. Here we explored whether maternal hair testosterone and cortisol, representing the pre-conception and first trimester periods respectively, may be used to predict pregnancy longevity. We recruited 125 pregnant women that contributed hair samples and answered a personal information questionnaire that included pre-conception smoking. We quantified steroids using commercial enzyme-linked immunosorbent assay kits. Gestational age at delivery was obtained from medical records. We used General Linear Models to predict gestation length. The model that included first trimester cortisol, pre-conception smoking, pre-conception testosterone and the interaction between first trimester cortisol and pre-conception smoking predicted 13% of the variance in gestation length (R2 = 0.130; n?=?105; p?=? 0.007). First trimester cortisol was the best predictor of gestational length. Women with high levels of cortisol in their first trimester had an increased probability of a full-term delivery. The effect of cortisol was especially pronounced in smokers (ß?=?1.69), compared to non-smokers (ß?=?0.45). Pre-conception testosterone also contributed to the model. Our study suggests that hair steroids may be used to predict pregnancy longevity, together with other contributing factors.  相似文献   
145.
ObjectiveTo compare clinical outcomes of 3 treatment regimens—glucocorticoids (GCs), oral contraceptives (OCs), or a combination of both—administered to adolescents and young women diagnosed in childhood with nonclassical congenital adrenal hyperplasia (NCCAH), who had been treated with GCs until their adult height was achieved.MethodsA retrospective study of medical records of 53 female patients with NCCAH followed in 3 tertiary pediatric endocrinology institutes. The 3 treatment groups were compared for the prevalence of hirsutism and acne, standardized body mass index (BMI)-standard deviation score (SDS), and androgen levels at the attainment of adult height (baseline), 1-year later, and at the last documented visit.ResultsAt baseline, there were no significant differences among groups in BMI-SDS, androgen levels, hirsutism prevalence, acne, or irregular menses. From baseline to the last visit, the rate of hirsutism declined significantly only in the OC group (37.5% vs 6.2%, respectively; P = .03). The rate of acne declined in the combined group (50% vs 9%, respectively; P = .03) with a similar tendency in the OC group (50% vs 12.5%, respectively; P = .05). No significant changes were observed in BMI-SDS for the entire cohort or any subgroup during follow-up. A significant rise in androstenedione (P < .001), testosterone (P < .01), and 17-hydroxyprogesterone (P < .01) levels was observed only in the OC group.ConclusionIn girls diagnosed in childhood with NCCAH, who require treatment for hyperandrogenism following completion of linear growth, management should be tailored individually using a patient-centered approach. Treatment with OCs might be better than that with GCs for regression of hirsutism and acne. The long-term effects of elevated levels of androgens associated with this treatment regimen should be further studied.  相似文献   
146.
147.
Marginating-pulmonary (MP) leukocytes are leukocytes that adhere to the inner endothelium of the lung capillaries. MP-leukocytes were shown to exhibit unique composition and characteristics compared to leukocytes of other immune compartments. Evidence suggests higher cytotoxicity of natural killer cells, and a distinct pro- and anti-inflammatory profile of the MP-leukocyte population compared to circulating or splenic immunocytes. The method presented herein enables selective harvesting of MP-leukocytes by forced perfusion of the lungs in either mice or rats. In contrast to other methods used to extract lung-leukocytes, such as tissue grinding and biological degradation, this method exclusively yields leukocytes from the lung capillaries, uncontaminated with parenchymal, interstitial, and broncho-alveolar cells. In addition, the perfusion technique better preserves the integrity and the physiological milieu of MP-leukocytes, without inducing physiological responses due to tissue processing. This unique MP leukocyte population is strategically located to identify and react towards abnormal circulating cells, as all circulating malignant cells and infected cells are detained while passing through the lung capillaries, physically interacting with endothelial cells and resident leukocytes,. Thus, selective harvesting of MP-leukocytes and their study under various conditions may advance our understanding of their biological and clinical significance, specifically with respect to controlling circulating aberrant cells and lung-related diseases.  相似文献   
148.
Lim Boo  Liat 《Journal of Zoology》1967,152(4):375-379
Examination of the endoparasites and stomach contents of Moonrats and Pentail treeshrews helps to establish certain facts as to the behaviour and food preference in their natural environment. Earthworms and arthropods are the main diet of Moonrats in the wild, with fish, crabs and land molluscs as supplementary food. In captivity, this animal fed primarily on fresh fish. The Pentail tree-shrews, on the other hand are more insectivorous although meat is occasionally eaten. This animal apparently is not strictly a canopydweller as was previously believed. The stomach contents, and the fact that some specimens were trapped on the forest floor indicates that they may often descend to ground level.  相似文献   
149.
MicroRNAs (miRNAs) have been reported to be involved in a variety of functions, including skeletal development and longitudinal growth. The aim of this study was to investigate the role of miRNAs in food-restriction-induced growth attenuation and nutrition-induced catch-up growth in the epiphyseal growth plate (EGP). Prepubertal rats were fed ad libitum or were subjected to 40% food restriction for 10 days followed by a renewal of the regular food supply. At sacrifice, tibial EGPs were excised, and the total RNA was extracted and loaded on miRNA microarrays. The miRNA microarray yielded more than 400 miRNAs that are expressed in the EGP of mature animals. Results were confirmed by quantitative polymerase chain reaction. Chondrocyte-specific miR-140-3p showed the highest expression in the mature EGP, and it was one of the few miRNAs that were significantly reduced following nutrition restriction. Changes in predicted miRNA targets were then followed with Western immunoblotting. Direct binding was demonstrated using exogenous miRNA, the 3′UTR of the target mRNA and a luciferase reporter assay. Nutrition restriction induced an increase in the level of the miR-140-3p target, NAD+-dependent SIRT1. This study is the first to show that SIRT1 and miRNAs expressed in the mature EGP are responsive to nutritional cues. Nutrition-induced epigenetic regulation of growth activates two parts of the epigenetic world — miRNAs and histone deacetylases — that are interconnected. Deciphering the role of epigenetic regulation in growth may open a new era of research and pave the way for the development of new treatments for children with growth disorders.  相似文献   
150.
The body temperature and oxygen consumption of freshly trapped Slow Loris (Nycticebus coucang) and Common Tree Shrews (Tupaia glis) were measured in Malaysia. The Slow Loris had a low body temperature and oxygen consumption, while the values for the Common Tree Shrew were relatively high. The data are discussed in relation to information obtained from captive animals. The importance of the Slow Loris is stressed because it represents one of the few natural hypometabolic states in primates.  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