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   142篇
  免费   0篇
系统科学   4篇
理论与方法论   1篇
现状及发展   19篇
研究方法   30篇
综合类   83篇
自然研究   5篇
  2016年   1篇
  2015年   1篇
  2014年   2篇
  2013年   3篇
  2012年   15篇
  2011年   23篇
  2010年   2篇
  2009年   2篇
  2008年   18篇
  2007年   17篇
  2006年   14篇
  2005年   6篇
  2004年   9篇
  2003年   3篇
  2002年   10篇
  1998年   2篇
  1995年   1篇
  1984年   1篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1972年   2篇
  1971年   1篇
  1969年   2篇
排序方式: 共有142条查询结果,搜索用时 15 毫秒
101.
102.
Focus groups have the potential to provide rapid and timely collation, integration and assembly of the views of a variety of different types of stakeholders into a plausible theory. This article reflects on a tertiary education institution's utilisation of focus group interviews (FGIs) as a qualitative evaluation instrument, using action research as the methodology. Our results suggest that employing focus groups is a valuable method of gaining more insight into and adding more depth to quantitative findings during quality management. Results from focus groups enable quality assurance practitioners to provide better remedial action plans. A set of guidelines is provided for the effective conducting of focus group interviews as part of an institutional quality assurance system.  相似文献   
103.
Summary Based on immunological comparisons of the serum albumins of phyllomedusine frogs with both hyline and bufonid species, it is suggested that phyllomedusine frogs be erected to familial status within the superfamily Bufonoidea.This study was initiated in the Department of Biochemistry, University of California, Berkeley. Part of this work was supported by NSF grant No. DEB75-23543The author gratefully acknowledges the helpful advice and discussion ofA. C. Wilson. Thanks are also due toD. Wake, H. Cogger, W. Duellman andR. Heyer for generously supplying frog samples.  相似文献   
104.
Positional cloning of hereditary deafness genes is a direct approach to identify molecules and mechanisms underlying auditory function. Here we report a locus for dominant deafness, DFNA36, which maps to human chromosome 9q13-21 in a region overlapping the DFNB7/B11 locus for recessive deafness. We identified eight mutations in a new gene, transmembrane cochlear-expressed gene 1 (TMC1), in a DFNA36 family and eleven DFNB7/B11 families. We detected a 1.6-kb genomic deletion encompassing exon 14 of Tmc1 in the recessive deafness (dn) mouse mutant, which lacks auditory responses and has hair-cell degeneration. TMC1 and TMC2 on chromosome 20p13 are members of a gene family predicted to encode transmembrane proteins. Tmc1 mRNA is expressed in hair cells of the postnatal mouse cochlea and vestibular end organs and is required for normal function of cochlear hair cells.  相似文献   
105.
Zusammenfassung Die orale Verabreichung von Bromelain in Form von 2 Ananase®-100-Tabletten an freiwillige Versuchspersonen verminderte bei diesen die Empfänglichkeit für die durch ADP induzierte Aggregation der Blutplättchen.

This work was supported by the Honolulu Chamber of Commerce research grants.  相似文献   
106.
Zusammenfassung Die Auffassung, dass die Gewebsangiotensinase-Aktivität entscheidend sei, ob sich eine Gewebs-Tachiphylaxie gegenüber Angiotensin entwickelt oder nicht, konnte durch Versuche an verschiedenartigen Geweben keine Bestätigung finden.

Supported by grants from the John A. Hartford Foundation, Inc., and the U.S. Army R and D Command No. DA-49-193-MD 2497.  相似文献   
107.
Ankylosing spondylitis is a common form of inflammatory arthritis predominantly affecting the spine and pelvis that occurs in approximately 5 out of 1,000 adults of European descent. Here we report the identification of three variants in the RUNX3, LTBR-TNFRSF1A and IL12B regions convincingly associated with ankylosing spondylitis (P < 5 × 10(-8) in the combined discovery and replication datasets) and a further four loci at PTGER4, TBKBP1, ANTXR2 and CARD9 that show strong association across all our datasets (P < 5 × 10(-6) overall, with support in each of the three datasets studied). We also show that polymorphisms of ERAP1, which encodes an endoplasmic reticulum aminopeptidase involved in peptide trimming before HLA class I presentation, only affect ankylosing spondylitis risk in HLA-B27-positive individuals. These findings provide strong evidence that HLA-B27 operates in ankylosing spondylitis through a mechanism involving aberrant processing of antigenic peptides.  相似文献   
108.
Type 1 diabetes is an autoimmune disease influenced by multiple genetic loci. Although more than 20 insulin-dependent diabetes (Idd) loci have been implicated in the nonobese diabetic (NOD) mouse model, few causal gene variants have been identified. Here we show that RNA interference (RNAi) can be used to probe candidate genes in this disease model. Slc11a1 encodes a phagosomal ion transporter, Nramp1, that affects resistance to intracellular pathogens and influences antigen presentation. This gene is the strongest candidate among the 42 genes in the Idd5.2 region; a naturally occurring mutation in the protective Idd5.2 haplotype results in loss of function of the Nramp1 protein. Using lentiviral transgenesis, we generated NOD mice in which Slc11a1 is silenced by RNAi. Silencing reduced the frequency of type 1 diabetes, mimicking the protective Idd5.2 region. Our results demonstrate a role for Slc11a1 in modifying susceptibility to type 1 diabetes and illustrate that RNAi can be used to study causal genes in a mammalian model organism.  相似文献   
109.
Ichthyosis vulgaris (OMIM 146700) is the most common inherited disorder of keratinization and one of the most frequent single-gene disorders in humans. The most widely cited incidence figure is 1 in 250 based on a survey of 6,051 healthy English schoolchildren. We have identified homozygous or compound heterozygous mutations R501X and 2282del4 in the gene encoding filaggrin (FLG) as the cause of moderate or severe ichthyosis vulgaris in 15 kindreds. In addition, these mutations are semidominant; heterozygotes show a very mild phenotype with incomplete penetrance. The mutations show a combined allele frequency of approximately 4% in populations of European ancestry, explaining the high incidence of ichthyosis vulgaris. Profilaggrin is the major protein of keratohyalin granules in the epidermis. During terminal differentiation, it is cleaved into multiple filaggrin peptides that aggregate keratin filaments. The resultant matrix is cross-linked to form a major component of the cornified cell envelope. We find that loss or reduction of this major structural protein leads to varying degrees of impaired keratinization.  相似文献   
110.
We recently reported two common filaggrin (FLG) null mutations that cause ichthyosis vulgaris and predispose to eczema and secondary allergic diseases. We show here that these common European mutations are ancestral variants carried on conserved haplotypes. To facilitate comprehensive analysis of other populations, we report a strategy for full sequencing of this large, highly repetitive gene, and we describe 15 variants, including seven that are prevalent. All the variants are either nonsense or frameshift mutations that, in representative cases, resulted in loss of filaggrin production in the epidermis. In an Irish case-control study, the five most common European mutations showed a strong association with moderate-to-severe childhood eczema (chi2 test: P = 2.12 x 10(-51); Fisher's exact test: heterozygote odds ratio (OR) = 7.44 (95% confidence interval (c.i.) = 4.9-11.3), and homozygote OR = 151 (95% c.i. = 20-1,136)). We found three additional rare null mutations in this case series, suggesting that the genetic architecture of filaggrin-related atopic dermatitis consists of both prevalent and rare risk alleles.  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