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   222篇
  免费   28篇
  2023年   2篇
  2022年   2篇
  2021年   7篇
  2019年   2篇
  2018年   2篇
  2017年   4篇
  2016年   3篇
  2015年   3篇
  2014年   5篇
  2013年   8篇
  2012年   15篇
  2011年   18篇
  2010年   14篇
  2009年   14篇
  2008年   11篇
  2007年   13篇
  2006年   8篇
  2005年   11篇
  2004年   13篇
  2003年   6篇
  2002年   9篇
  2001年   8篇
  2000年   7篇
  1999年   9篇
  1998年   4篇
  1997年   6篇
  1996年   2篇
  1995年   3篇
  1994年   2篇
  1992年   4篇
  1990年   3篇
  1989年   2篇
  1988年   9篇
  1987年   4篇
  1986年   1篇
  1984年   2篇
  1979年   1篇
  1978年   3篇
  1977年   3篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1967年   1篇
  1957年   1篇
排序方式: 共有250条查询结果,搜索用时 16 毫秒
131.
132.
133.
Sequencing of the complete mitochondrial DNA control region from 31 samples of the Eurasian otter, Lutra lutra , enabled us to establish the length and structure of this fragment, as well as to describe, for the first time, the RS3 repetitive region located at the 3' end. In addition, genetic variability of the 5' end was examined in 63 individuals, 57 of which were wild otters from the Iberian Peninsula and six captive reared otters. This analysis resulted in extremely low variability. All the samples from the Iberian Peninsula share a single haplotype, Lut 1, the most common haplotype in Europe. Captive otters showed two haplotypes: Lut 3, which has been described in wild otters from eastern Germany, and Lut 6, an haplotype not described to date. Higher variability was observed in the repetitive RS3 region. The tandem repeat was composed of an array of ten repeat units of 22 bp with differences in the repetitive motifs that differed in the arrays of different specimens. In total, 20 different haplotypes from 31 individuals were found. However, the geographical distribution of these haplotypes did not generate a phylogeographical signal. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 397–403.  相似文献   
134.
135.
FREE CHOICE PROFILING OF CHILEAN GOAT CHEESE   总被引:1,自引:0,他引:1  
Different goat cheeses from Chile were studied by Free-Choice Profile (FCP) analysis. Generalized Procrustes Analysis (GPA) applied to FCP data permitted differentiation between samples and informed on the attributes responsible for the observed differences. Appearance was a dominant factor in discriminating samples and to a lesser degree textural variables were also correlated with GPA dimensions. In acceptability the fresh cheeses were significantly preferred over the ripened ones.  相似文献   
136.

Background  

There are four widely used experimental strains of N. gonorrhoeae, one of which has been sequenced and used as the basis for the construction of a multi-strain, mutli-species pan-neisserial microarray. Although the N. gonorrhoeae population structure is thought to be less diverse than N. meningitidis, there are some recognized gene-complement differences between strains, including the 59 genes of the Gonococcal Genetic Island. In this study we have investigated the three experimental strains that have not been sequenced to determine the extent and nature of their similarities and differences.  相似文献   
137.
The purpose of this study was to examine parents' perceptions of the health and health-related quality of life in a series of children and adolescents with cleft and other craniofacial anomalies. The subjects for this prospective study were a consecutive series of 54 children and adolescents presenting to an outpatient craniofacial anomalies surgery clinic, ages 5 to 18 years (mean, 8.9 +/- 4.2 years), 50 percent with cleft lip and/or palate, 9 percent synostotic (two coronal, two bicoronal, and one sagittal), 17 percent syndromic (two Apert, one Crouzon, one Noonan, two Goldenhar, two Smith-Lemli-Opitz, and one brachio-oto-renal), and 24 percent with other diagnoses. Subjects were divided into two groups, those with primary cleft lip and/or palate and those with other craniofacial anomalies. Health and health-related quality of life were assessed with the Child Health Questionnaire version PF28, a reliable and valid 28-Likert-item questionnaire completed by parents and yielding physical and psychosocial status scale scores. Physical and psychosocial scale scores largely fell within normal limits for the subset of children with cleft lip and/or palate. There were significant group differences in parents' ratings of global health status, with greater health concerns noted in the non-cleft lip and/or palate group. There were no significant associations between either age or sex and physical or psychosocial health. Physical health, behavior, and psychological status were highly correlated. Using a health status and quality-of-life assessment instrument, findings indicate perceived health differences between groups with and without primary cleft lip and/or palate. In contrast to normative data with the Child Health Questionnaire, findings suggest that there is a significant association between perceived physical health and psychosocial adjustment in the population of children with craniofacial anomalies. The significant perceived health needs of the non-cleft lip and/or palate group and the association between physical health and psychological adjustment highlight the importance of the interdisciplinary nature of craniofacial teams.  相似文献   
138.
Photobiomodulation by light in the red to near infrared range (630-1000 nm) using low energy lasers or light-emitting diode (LED) arrays has been shown to accelerate wound healing, improve recovery from ischemic injury in the heart and attenuate degeneration in the injured optic nerve. Recent evidence indicates that the therapeutic effects of red to near infrared light result, in part, from intracellular signaling mechanisms triggered by the interaction of NIR light with the mitochondrial photoacceptor molecule cytochrome c oxidase. We have demonstrated that NIR-LED photo-irradiation increases the production of cytochrome oxidase in cultured primary neurons and reverses the reduction of cytochrome oxidase activity produced by metabolic inhibitors. We have also shown that NIR-LED treatment prevents the development of oral mucositis in pediatric bone marrow transplant patients. Photobiomodulation improves wound healing in genetically diabetic mice by upregulating genes important in the promotion of wound healing. More recent studies have provided evidence for the therapeutic benefit of NIR-LED treatment in the survival and functional recovery of the retina and optic nerve in vivo after acute injury by the mitochondrial toxin, formic acid generated in the course of methanol intoxication. Gene discovery studies conducted using microarray technology documented a significant upregulation of gene expression in pathways involved in mitochondrial energy production and antioxidant cellular protection. These findings provide a link between the actions of red to near infrared light on mitochondrial oxidative metabolism in vitro and cell injury in vivo. Based on these findings and the strong evidence that mitochondrial dysfunction is involved in the pathogenesis of numerous diseases processes, we propose that NIR-LED photobiomodulation represents an innovative and non-invasive therapeutic approach for the treatment of tissue injury and disease processes in which mitochondrial dysfunction is postulated to play a role including diabetic retinopathy, age-related macular degeneration, Leber's hereditary optic neuropathy and Parkinson's disease.  相似文献   
139.
Mammalian Alix is a multifunctional adaptor protein involved in cell death, receptor endocytosis, endosomal protein sorting and cell adhesion by associating with various proteins such as ALG-2, CIN85/Rukl/SETA, endophilins, CHMP4s and TSG101. HD-PTP is a paralog of Alix and a putative protein tyrosine phosphatase (PTP) that contains a Bro1 domain, coiled-coils, a proline-rich region (PRR) in addition to a PTP domain. We investigated interactions between HD-PTP and Alix-binding proteins. In the yeast two-hybrid assay, HD-PTP showed positive interactions with CHMP4b/Shax1, TSG101, endophilin A1 and ALG-2 but not with either RabGAPLP or CIN85. We confirmed the interactions in a mammalian system by Strep-pulldown assays in which pulldown products from the lysates of HEK293T cells expressing either Strep-tagged HD-PTP alone or co-expressing with epitope-tagged proteins were analyzed by Western blotting using specific antibodies. While Alix associated with both ALG-2 and TSG101 in a Ca2+-dependent manner, HD-PTP interacted with ALG-2 Ca2+-dependently but with TSG101 Ca2+-independently.  相似文献   
140.
文章对相同条件下培养的莱茵衣藻野生型CC-137和八氢番茄红素脱氢酶(phytoene desaturase,PDS)基因突变株Nfr-4的生长进行分析;并用反相高效液相色谱分析总有色类胡萝卜素以及叶绿素含量变化,结果表明两者生长的差异明显;Nfr-4突变株的单细胞叶绿素和总有色类胡萝卜素含量高于野生型CC-137的。  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