全文获取类型
收费全文 | 212篇 |
免费 | 18篇 |
专业分类
230篇 |
出版年
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 5篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 18篇 |
2009年 | 10篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 10篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 4篇 |
1972年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1958年 | 1篇 |
1955年 | 1篇 |
1952年 | 1篇 |
1948年 | 1篇 |
1947年 | 1篇 |
1936年 | 1篇 |
1913年 | 1篇 |
1911年 | 2篇 |
排序方式: 共有230条查询结果,搜索用时 0 毫秒
61.
Ferry Cornelissen Adriana MC Mus Patrick S Asmawidjaja Jan Piet van Hamburg Joel Tocker Erik Lubberts 《Arthritis research & therapy》2009,11(6):R194
Introduction
Interleukin (IL)-23 is essential for the development of various experimental autoimmune models. However, the role of IL-23 in non-autoimmune experimental arthritis remains unclear. Here, we examined the role of IL-23 in the non-autoimmune antigen-induced arthritis (AIA) model. In addition, the regulatory potential of IL-23 in IL-17A and retinoic acid-related orphan receptor gamma t (RORγt) expression in CD4+ and TCRγδ+ T cells was evaluated systemically as well as at the site of inflammation. 相似文献62.
In 4-d-old dark-grown oat (Avena sativa L.) seedlings, the majority of the type-I-phytochrome (phyA) mRNA was found within 10 mm of the tip of the coleoptile sheath and in the mesocotyl node; almost none was detected in the enclosed primary leaf. In contrast, chlorophyll-a/b-binding-protein (cab) mRNAs were found almost exclusively in the enclosed primary leaf and were barely detectable in total-RNA samples from the coleoptile sheath or mesocotyl node of red-light-treated etiolated seedlings. Separated, dark-grown primary leaves responded to a red-light treatment by increasing cab-mRNA abundance in the absence of the coleoptile sheath or mesocotyl node tissues.Abbreviations
cab
gene for chlorophyll-a/b-binding protein
- kb
kilobase
-
phyA
gene for type-I-phytochrome protein
We are grateful to the members of the laboratory Dave Higgs, Theresa Tirimanne, Dr. Dennis Byrne, Bruce Held, Linda Barnes, Dr. Isaac John, and Iffat Rahim, for their helpful discussions and critical review. This work was supported by USDA grant No. 88-37261-4196 and No. 91-37304-6397, the Iowa State University Biotechnology Program, and the Molecular, Cellular, and Developmental Biology Program. 相似文献
63.
Novel propeptide function in 20 S proteasome assembly influences beta subunit composition 总被引:1,自引:0,他引:1
The assembly of eukaryotic 20 S proteasomes involves the formation of half-proteasomes where precursor beta-type subunits gather in position on an alpha-subunit ring, followed by the association of two half-proteasomes and beta-subunit processing. In vertebrates three additional beta-subunits (beta1i/LMP2, beta2i/MECL1, and beta5i/LMP7) can be synthesized and substituted for constitutive homologues (beta1/delta, beta2/Z, and beta5/X) to yield immunoproteasomes, which are important for generating certain antigenic peptides. We have shown previously that when all six beta-subunits are present, cooperative assembly mechanisms limit the diversity of proteasome populations. Specifically, LMP7 is incorporated preferentially over X into preproteasomes containing LMP2 and MECL1. We show here that the LMP7 propeptide is responsible for this preferential incorporation, and it also enables LMP7 to incorporate into proteasomes containing delta and Z. In contrast, the X propeptide restricts incorporation to proteasomes with delta and Z. Furthermore, we demonstrate that the LMP7 propeptide can function in trans when expressed on LMP2, and that its NH(2)-terminal and mid-regions are particularly critical for function. In addition to identifying a novel propeptide function, our results raise the possibility that one consequence of LMP7 incorporation into both immunoproteasomes and delta/Z proteasomes may be to increase the diversity of antigenic peptides that can be generated. 相似文献
64.
65.
Bone dysplasia sclerosteosis results from loss of the SOST gene product, a novel cystine knot-containing protein 总被引:20,自引:0,他引:20
Brunkow ME Gardner JC Van Ness J Paeper BW Kovacevich BR Proll S Skonier JE Zhao L Sabo PJ Fu Y Alisch RS Gillett L Colbert T Tacconi P Galas D Hamersma H Beighton P Mulligan J 《American journal of human genetics》2001,68(3):577-589
Sclerosteosis is an autosomal recessive sclerosing bone dysplasia characterized by progressive skeletal overgrowth. The majority of affected individuals have been reported in the Afrikaner population of South Africa, where a high incidence of the disorder occurs as a result of a founder effect. Homozygosity mapping in Afrikaner families along with analysis of historical recombinants localized sclerosteosis to an interval of approximately 2 cM between the loci D17S1787 and D17S930 on chromosome 17q12-q21. Here we report two independent mutations in a novel gene, termed "SOST." Affected Afrikaners carry a nonsense mutation near the amino terminus of the encoded protein, whereas an unrelated affected person of Senegalese origin carries a splicing mutation within the single intron of the gene. The SOST gene encodes a protein that shares similarity with a class of cystine knot-containing factors including dan, cerberus, gremlin, prdc, and caronte. The specific and progressive effect on bone formation observed in individuals affected with sclerosteosis, along with the data presented in this study, together suggest that the SOST gene encodes an important new regulator of bone homeostasis. 相似文献
66.
67.
Jennifer Gettings Braden O'Neill Dave A. Chokshi James A. Colbert Peter Gill Gerald Lebovic Joel Lexchin Navindra Persaud 《PloS one》2014,9(1)
Background
Pharmaceutical advertisements have been argued to provide revenue that medical journals require but they are intended to alter prescribing behaviour and they are known to include low quality information. We determined whether a difference exists in the current level of pharmaceutical advertising in print general medical journals, and we estimated the revenue generated from print pharmaceutical advertising.Methods
Six print general medical journals in Canada, the United States, and the United Kingdom were sampled between 2007 and 2012. The number of advertisements and other journal content in selected issues of the Canadian Medical Association Journal (CMAJ), Canadian Family Physician (CFP), Journal of the American Medical Association (JAMA), New England Journal of Medicine (NEJM), British Medical Journal (BMJ), and Lancet were determined. Revenue gained from pharmaceutical advertising was estimated using each journal''s 2013 advertising price list.Findings
The two Canadian journals sampled (CMAJ, CFP) contained five times more advertisements than the two American journals (JAMA, NEJM), and two British journals (BMJ, Lancet) (p<0.0001). The estimated annual revenue from pharmaceutical advertisements ranged from £0.025 million (for Lancet) to £3.8 million (for JAMA). The cost savings due to revenue from pharmaceutical advertising to each individual subscriber ranged from £0.02 (for Lancet) to £3.56 (for CFP) per issue.Conclusion
The volume of pharmaceutical advertisements differs between general medical journals, with the two Canadian journals sampled containing the most advertisements. International and temporal variations suggest that there is an opportunity for all general medical journals to reduce the number of pharmaceutical advertisements, explore other sources of revenue, and increase transparency regarding sources of revenue. 相似文献68.
A genome survey of Moniliophthora perniciosa gives new insights into Witches' Broom Disease of cacao
Jorge MC Mondego Marcelo F Carazzolle Gustavo GL Costa Eduardo F Formighieri Lucas P Parizzi Johana Rincones Carolina Cotomacci Dirce M Carraro Anderson F Cunha Helaine Carrer Ramon O Vidal Raíssa C Estrela Odalys García Daniela PT Thomazella Bruno V de Oliveira Acássia BL Pires Carolina S Maria Rio Marcos Renato R Araújo Marcos H de Moraes Luis AB Castro Karina P Gramacho Marilda S Gonçalves José P Moura Neto Aristóteles Góes Neto Luciana V Barbosa Mark J Guiltinan Bryan A Bailey Lyndel W Meinhardt Julio CM Cascardo Gonçalo AG Pereira 《BMC genomics》2008,9(1):1-25
69.
Coombes S Timofeeva Y Svensson CM Lord GJ Josić K Cox SJ Colbert CM 《Biological cybernetics》2007,97(2):137-149
Dendrites form the major components of neurons. They are complex branching structures that receive and process thousands of
synaptic inputs from other neurons. It is well known that dendritic morphology plays an important role in the function of
dendrites. Another important contribution to the response characteristics of a single neuron comes from the intrinsic resonant
properties of dendritic membrane. In this paper we combine the effects of dendritic branching and resonant membrane dynamics
by generalising the “sum-over-trips” approach (Abbott et al. in Biol Cybernetics 66, 49–60 1991). To illustrate how this formalism
can shed light on the role of architecture and resonances in determining neuronal output we consider dual recording and reconstruction
data from a rat CA1 hippocampal pyramidal cell. Specifically we explore the way in which an I
h
current contributes to a voltage overshoot at the soma. 相似文献
70.