全文获取类型
收费全文 | 627篇 |
免费 | 88篇 |
国内免费 | 2篇 |
出版年
2019年 | 4篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 14篇 |
2015年 | 17篇 |
2014年 | 23篇 |
2013年 | 21篇 |
2012年 | 39篇 |
2011年 | 40篇 |
2010年 | 15篇 |
2009年 | 25篇 |
2008年 | 28篇 |
2007年 | 20篇 |
2006年 | 38篇 |
2005年 | 23篇 |
2004年 | 28篇 |
2003年 | 23篇 |
2002年 | 25篇 |
2001年 | 11篇 |
2000年 | 27篇 |
1999年 | 18篇 |
1998年 | 10篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1992年 | 16篇 |
1991年 | 13篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 12篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 14篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1978年 | 5篇 |
1973年 | 4篇 |
1971年 | 8篇 |
1970年 | 4篇 |
1969年 | 4篇 |
1965年 | 3篇 |
1964年 | 4篇 |
1960年 | 3篇 |
1923年 | 3篇 |
1922年 | 3篇 |
1910年 | 3篇 |
排序方式: 共有717条查询结果,搜索用时 293 毫秒
51.
Ammonia emissions during vermicomposting of sheep manure 总被引:2,自引:0,他引:2
The effect of C:N ratio, temperature and water content on ammonia volatilization during two-phase composting of sheep manure was evaluated. The aerobic phase was conducted under field conditions. This was followed by Phase II, vermicomposting, conducted in the laboratory under controlled conditions of water content (70% and 80%) and temperature (15 and 22 °C). The addition of extra straw lead to a 10% reduction in NH3 volatilization compared to sheep manure composted without extra straw. Temperature and water content significantly effected ammonia volatilization at 0 day in Phase II, with a water content of 70% and temperature of 22 °C leading to greater losses of ammonia. Nitrogen loss by ammonia volatilization during vermicomposting ranged from 8% to 15% of the initial N content. The addition of extra straw did not result in significant differences in total carbon content following vermicomposting. 相似文献
52.
Tran TD Pryde DC Jones P Adam FM Benson N Bish G Calo F Ciaramella G Dixon R Duckworth J Fox DN Hay DA Hitchin J Horscroft N Howard M Gardner I Jones HM Laxton C Parkinson T Parsons G Proctor K Smith MC Smith N Thomas A 《Bioorganic & medicinal chemistry letters》2011,21(8):2389-2393
The synthesis and structure-activity relationships of a series of novel interferon inducers are described. Pharmacokinetic studies and efficacy assessment of a series of 8-oxo-3-deazapurine analogues led to the identification of compound 33, a potent and selective agonist of the TLR7 receptor with an excellent in vivo efficacy profile in a mouse model. 相似文献
53.
Parkinson EI Jason Hatfield M Tsurkan L Hyatt JL Edwards CC Hicks LD Yan B Potter PM 《Bioorganic & medicinal chemistry》2011,19(15):4635-4643
Carboxylesterases (CE) are ubiquitous enzymes found in both human and animal tissues and are responsible for the metabolism of xenobiotics. This includes numerous natural products, as well as a many clinically used drugs. Hence, the activity of these agents is likely dependent upon the levels and location of CE expression. We have recently identified benzil is a potent inhibitor of mammalian CEs, and in this study, we have assessed the ability of analogues of this compound to inhibit these enzymes. Three different classes of molecules were assayed: one containing different atoms vicinal to the carbonyl carbon atom and the benzene ring [PhXC(O)C(O)XPh, where X=CH?, CHBr, N, S, or O]; a second containing a panel of alkyl 1,2-diones demonstrating increasing alkyl chain length; and a third consisting of a series of 1-phenyl-2-alkyl-1,2-diones. In general, with the former series of molecules, heteroatoms resulted in either loss of inhibitory potency (when X=N), or conversion of the compounds into substrates for the enzymes (when X=S or O). However, the inclusion of a brominated methylene atom resulted in potent CE inhibition. Subsequent analysis with the alkyl diones [RC(O)C(O)R, where R ranged from CH? to C?H??] and 1-phenyl-2-alkyl-1,2-diones [PhC(O)C(O)R where R ranged from CH? to C?H??], demonstrated that the potency of enzyme inhibition directly correlated with the hydrophobicity (clogP) of the molecules. We conclude from these studies that that the inhibitory power of these 1,2-dione derivatives depends primarily upon the hydrophobicity of the R group, but also on the electrophilicity of the carbonyl group. 相似文献
54.
Ceribelli A Yao B Dominguez-Gutierrez PR Nahid MA Satoh M Chan EK 《Arthritis research & therapy》2011,13(4):229
MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded RNAs about 21 nucleotides in length. miRNAs have been shown
to regulate gene expression and thus influence a wide range of physiological and pathological processes. Moreover, they are
detected in a variety of sources, including tissues, serum, and other body fluids, such as saliva. The role of miRNAs is evident
in various malignant and nonmalignant diseases, and there is accumulating evidence also for an important role of miRNAs in
systemic rheumatic diseases. Abnormal expression of miRNAs has been reported in autoimmune diseases, mainly in systemic lupus
erythematosus and rheumatoid arthritis. miRNAs can be aberrantly expressed even in the different stages of disease progression,
allowing miRNAs to be important biomarkers, to help understand the pathogenesis of the disease, and to monitor disease activity
and effects of treatment. Different groups have demonstrated a link between miRNA expression and disease activity, as in the
case of renal flares in lupus patients. Moreover, miRNAs are emerging as potential targets for new therapeutic strategies
of autoimmune disorders. Taken together, recent data demonstrate that miRNAs can influence mechanisms involved in the pathogenesis,
relapse, and specific organ involvement of autoimmune diseases. The ultimate goal is the identification of a miRNA target
or targets that could be manipulated through specific therapies, aiming at activation or inhibition of specific miRNAs responsible
for the development of disease. 相似文献
55.
Satoh M Krzyszczak ME Li Y Ceribelli A Ross SJ Chan EK Segal MS Bubb MR Sobel ES Reeves WH 《Arthritis research & therapy》2011,13(3):R73
Introduction
The presence of anti-topoisomerase I (topo I) antibodies is a classic scleroderma (SSc) marker presumably associated with a unique clinical subset. Here the clinical association of anti-topo I was reevaluated in unselected patients seen in a rheumatology clinic setting. 相似文献56.
Plant-based microarray data at the European Bioinformatics Institute. Introducing AtMIAMExpress, a submission tool for Arabidopsis gene expression data to ArrayExpress 下载免费PDF全文
Mukherjee G Abeygunawardena N Parkinson H Contrino S Durinck S Farne A Holloway E Lilja P Moreau Y Oezcimen A Rayner T Sharma A Brazma A Sarkans U Shojatalab M 《Plant physiology》2005,139(2):632-636
ArrayExpress is a public microarray repository founded on the Minimum Information About a Microarray Experiment (MIAME) principles that stores MIAME-compliant gene expression data. Plant-based data sets represent approximately one-quarter of the experiments in ArrayExpress. The majority are based on Arabidopsis (Arabidopsis thaliana); however, there are other data sets based on Triticum aestivum, Hordeum vulgare, and Populus subsp. AtMIAMExpress is an open-source Web-based software application for the submission of Arabidopsis-based microarray data to ArrayExpress. AtMIAMExpress exports data in MAGE-ML format for upload to any MAGE-ML-compliant application, such as J-Express and ArrayExpress. It was designed as a tool for users with minimal bioinformatics expertise, has comprehensive help and user support, and represents a simple solution to meeting the MIAME guidelines for the Arabidopsis community. Plant data are queryable both in ArrayExpress and in the Data Warehouse databases, which support queries based on gene-centric and sample-centric annotation. The AtMIAMExpress submission tool is available at http://www.ebi.ac.uk/at-miamexpress/. The software is open source and is available from http://sourceforge.net/projects/miamexpress/. For information, contact miamexpress@ebi.ac.uk. 相似文献
57.
SIV DNA vaccine co-administered with IL-12 expression plasmid enhances CD8 SIV cellular immune responses in cynomolgus macaques 总被引:5,自引:0,他引:5
Boyer JD Robinson TM Kutzler MA Parkinson R Calarota SA Sidhu MK Muthumani K Lewis M Pavlakis G Felber B Weiner D 《Journal of medical primatology》2005,34(5-6):262-270
Current evidence suggests that a strong induced CD8 human immunodeficiency virus type 1 (HIV-1)-specific cell mediated immune response may be an important aspect of an HIV vaccine. The response rates and the magnitude of the CTL responses induced by current DNA vaccines in humans need to be improved and cellular immune responses to DNA vaccines can be enhanced in mice by co-delivering DNA plasmids expressing immune modulators. Two reported to work well in the mouse systems are interleukin (IL)-12 and CD40L. We sought to compare these molecular adjuvants in a primate model system. The cDNA for macaque IL-12 and CD40L were cloned into DNA vectors. Groups of cynomolgus macaques were immunized with 2 mg of plasmid expressing SIVgag alone or in combination with either IL-12 or CD40L. CD40L did not appear to enhance the cellular immune response to SIVgag antigen. However, more robust results were observed in animals co-injected with the IL-12 molecular adjuvant. The IL-12 expanded antigen-specific IFN-gamma positive effector cells as well as granzyme B production. The vaccine immune responses contained both a CD8 component as well a CD4 component. The adjuvanted DNA vaccines illustrate that IL-12 enhances a CD8 vaccine immune response, however, different cellular profiles. 相似文献
58.
Leung S Holbrook A King B Lu HT Evans V Miyamoto N Mallari C Harvey S Davey D Ho E Li WW Parkinson J Horuk R Jaroch S Berger M Skuballa W West C Pulk R Phillips G Bryant J Subramanyam B Schaefer C Salamon H Lyons E Schilling D Seidel H Kraetzschmar J Snider M Perez D 《Journal of biomolecular screening》2005,10(2):157-167
Effector functions and proliferation of T helper (Th) cells are influenced by cytokines in the environment. Th1 cells respond to a synergistic effect of interleukin-12 (IL-12) and interleukin-18 (IL-18) to secrete interferon-gamma (IFN-gamma). In contrast, Th2 cells respond to interleukin-4 (IL-4) to secrete IL-4, interleukin-13 (IL-13), interleukin-5 (IL-5), and interleukin-10 (IL-10). The authors were interested in identifying nonpeptide inhibitors of the Th1 response selective for the IL-12/IL-18-mediated secretion of IFN-gamma while leaving the IL-4-mediated Th2 cytokine secretion relatively intact. The authors established a screening protocol using human peripheral blood mononuclear cells (PBMCs) and identified the hydrazino anthranilate compound 1 as a potent inhibitor of IL-12/IL-18-mediated IFN-gamma secretion from CD3(+) cells with an IC(50) around 200 nM. The inhibitor was specific because it had virtually no effect on IL-4-mediated IL-13 release from the same population of cells. Further work established that compound 1 was a potent intracellular iron chelator that inhibited both IL-12/IL-18- and IL-4-mediated T cell proliferation. Iron chelation affects multiple cellular pathways in T cells. Thus, the IL-12/IL-18-mediated proliferation and IFN-gamma secretion are very sensitive to intracellular iron concentration. However, the IL-4-mediated IL-13 secretion does not correlate with proliferation and is partially resistant to potent iron chelation. 相似文献
59.
60.
Stimulus- and cell-type-specific release of purines in cultured rat forebrain astrocytes and neurons
Adenosine is formed during conditions that deplete ATP, such as ischemia. Adenosine deaminase converts adenosine into inosine, and both adenosine and inosine can be beneficial for postischemic recovery. This study investigated adenosine and inosine release from astrocytes and neurons during chemical hypoxia or oxygen-glucose deprivation. In both cell types, 2-deoxyglucose was the most effective stimulus for depleting cellular ATP and for evoking inosine release; in contrast, oxygen-glucose deprivation evoked the greatest adenosine release. alpha,beta-Methylene ADP, an inhibitor of ecto-5'nucleotidase, significantly reduced adenosine release from astrocytes but not neurons. Dipyridamole, an inhibitor of equilibrative nucleoside transporters, inhibited both adenosine and inosine release from neurons. Erythro-9-(2-hydroxy-3-nonyl)adenine, an inhibitor of adenosine deaminase, reduced neuronal inosine release evoked by oxygen-glucose deprivation but not by 2-deoxyglucose treatment. These data indicate that (1). astrocytes release adenine nucleotides that are hydrolyzed extracellularly to adenosine, whereas neurons release adenosine per se, (2). inosine is formed intracellularly and released via nucleoside transporters, and (3). inosine is formed by an adenosine deaminase-dependent pathway during oxygen-glucose deprivation but not during 2-deoxyglucose treatment. In summary, the metabolic pathways for adenosine formation and release were cell-type dependent whereas the pathways for inosine formation were stimulus dependent. 相似文献