全文获取类型
收费全文 | 334篇 |
免费 | 46篇 |
专业分类
380篇 |
出版年
2022年 | 2篇 |
2021年 | 7篇 |
2020年 | 6篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 20篇 |
2013年 | 23篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 17篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 17篇 |
2006年 | 12篇 |
2005年 | 17篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 13篇 |
1999年 | 4篇 |
1998年 | 14篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1975年 | 4篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1969年 | 2篇 |
1967年 | 4篇 |
1950年 | 2篇 |
1944年 | 2篇 |
1943年 | 2篇 |
排序方式: 共有380条查询结果,搜索用时 0 毫秒
61.
McCallum FJ Persson KE Mugyenyi CK Fowkes FJ Simpson JA Richards JS Williams TN Marsh K Beeson JG 《PloS one》2008,3(10):e3571
Background
Antibodies that inhibit the growth of blood-stage Plasmodium falciparum may play an important role in acquired and vaccine-induced immunity in humans. However, the acquisition and activity of these antibodies is not well understood.Methods
We tested dialysed serum and purified immunoglobulins from Kenyan children and adults for inhibition of P. falciparum blood-stage growth in vitro using different parasite lines. Serum antibodies were measured by ELISA to blood-stage parasite antigens, extracted from P. falciparum schizonts, and to recombinant merozoite surface protein 1 (42 kDa C-terminal fragment, MSP1-42).Results
Antibodies to blood-stage antigens present in schizont protein extract and to recombinant MSP1-42 significantly increased with age and were highly correlated. In contrast, growth-inhibitory activity was not strongly associated with age and tended to decline marginally with increasing age and exposure, with young children demonstrating the highest inhibitory activity. Comparison of growth-inhibitory activity among samples collected from the same population at different time points suggested that malaria transmission intensity influenced the level of growth-inhibitory antibodies. Antibodies to recombinant MSP1-42 were not associated with growth inhibition and high immunoglobulin G levels were poorly predictive of inhibitory activity. The level of inhibitory activity against different isolates varied.Conclusions
Children can acquire growth-inhibitory antibodies at a young age, but once they are acquired they do not appear to be boosted by on-going exposure. Inhibitory antibodies may play a role in protection from early childhood malaria. 相似文献62.
63.
Changes in macromolecular composition and morphology of Bacteroides fragilis cultured in a complex medium. 下载免费PDF全文
Changes in cell macromolecular composition during different phases of growth correlated with alterations in morphology of the obligately anaerobic bacterium, Bacteroides fragilis, grown in a complex medium. 相似文献
64.
Alistair Paterson Angzzas Kassim Susan McCallum Mary Woodhead Kay Smith Dzeti Zait Julie Graham 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2013,126(1):33-48
Raspberry volatiles are important for perceptions of sensory quality, mould resistance and some have nutraceutical activities. Twelve raspberry character volatiles were quantified, 11 of them in fruit from two seasons, from plants from the Glen Moy × Latham mapping population growing in both open field and under cover (polytunnels). Effects of season and environment were examined for their impact on the content of α-ionone, α-ionol, β-ionone, β-damascenone, linalool, geraniol, benzyl alcohol, (Z)-3-hexenol, acetoin, acetic and hexanoic acids, whilst raspberry ketone was measured in one season. A significant variation was observed in fruit volatiles in all progeny between seasons and method of cultivation. Quantitative trait loci were determined and mapped to six of the seven linkage groups, as were candidate genes in the volatiles pathways. 相似文献
65.
66.
Building strong relationships between conservation genetics and primary industry leads to mutually beneficial genomic advances 下载免费PDF全文
Stephanie J. Galla Thomas R. Buckley Rob Elshire Marie L. Hale Michael Knapp John McCallum Roger Moraga Anna W. Santure Phillip Wilcox Tammy E. Steeves 《Molecular ecology》2016,25(21):5267-5281
Several reviews in the past decade have heralded the benefits of embracing high‐throughput sequencing technologies to inform conservation policy and the management of threatened species, but few have offered practical advice on how to expedite the transition from conservation genetics to conservation genomics. Here, we argue that an effective and efficient way to navigate this transition is to capitalize on emerging synergies between conservation genetics and primary industry (e.g., agriculture, fisheries, forestry and horticulture). Here, we demonstrate how building strong relationships between conservation geneticists and primary industry scientists is leading to mutually‐beneficial outcomes for both disciplines. Based on our collective experience as collaborative New Zealand‐based scientists, we also provide insight for forging these cross‐sector relationships. 相似文献
67.
Christopher J. Morrison Rahul Godawat Scott A. McCallum Shekhar Garde Steven M. Cramer 《Biotechnology and bioengineering》2009,102(5):1428-1437
A parallel batch screening technique was employed to identify chemically selective displacers which exhibited exclusive separation behavior for the protein pair α‐chymotrypsin/ribonuclease A on a strong cation exchange resin. Two selective displacers, 1‐(4‐chlorobenzyl)piperidin‐3‐aminesulfate and N′1′‐(4‐methyl‐quinolin‐2‐yl)‐ethane‐1,2‐diamine dinitrate, and one non‐selective displacer, spermidine, were selected as model systems to investigate the mechanism of chemically selective displacement chromatography. Saturation transfer difference (STD) NMR was used to directly evaluate displacer–protein binding. The results indicated that while binding occurred between the two chemically selective displacers and the more hydrophobic protein, α‐chymotrypsin, no binding was observed with ribonuclease A. Further, the non‐selective displacer, spermidine, was not observed to bind to either protein. Importantly, the binding event was observed to occur primarily on the aromatic portion of the selective displacers. Extensive molecular dynamic simulations of protein–displacer–water solution were also carried out. The MD results corroborated the NMR findings demonstrating that the binding of selective displacers occurred primarily on hydrophobic surface patches of α‐chymotrypsin, while no significant long term binding to ribonuclease A was observed. The non‐selective displacer did not show significant binding to either of the proteins. MD simulations also indicated that the charged amine group of the selective displacers in the bound state was primarily oriented towards the solvent, potentially facilitating their interaction with a resin surface. These results directly confirm that selective binding between a protein and displacer is the mechanism by which chemically selective displacement occurs. This opens up many possibilities for future molecular design of selective displacers for a range of applications. Biotechnol. Bioeng. 2009;102: 1428–1437. © 2008 Wiley Periodicals, Inc. 相似文献
68.
Wanhua Lu Lynn McCallum Alexandra E. Irvine 《Journal of cell communication and signaling》2009,3(2):147-149
We have adapted the CyQuant® assay to provide a simple, rapid, sensitive and highly reproducible method for measuring cell adhesion. The modified CyQuant® assay eliminates the requirement for labour intensive fluorescent labelling protocols prior to experimentation and has the sensitivity to measure small numbers (>1000) of adherent cells. 相似文献
69.
McCallum SE Parameswaran N Perez XA Bao S McIntosh JM Grady SR Quik M 《Journal of neurochemistry》2006,96(4):960-972
Clinical symptoms of Parkinson's disease only become evident after 70-80% reductions in striatal dopamine. To investigate the importance of pre-synaptic dopaminergic mechanisms in this compensation, we determined the effect of nigrostriatal damage on dopaminergic markers and function in primates. MPTP treatment resulted in a graded dopamine loss with moderate to severe declines in ventromedial striatum (approximately 60-95%) and the greatest reductions (approximately 95-99%) in dorsolateral striatum. A somewhat less severe pattern of loss was observed for striatal nicotinic receptor, tyrosine hydroxylase and vesicular monoamine transporter expression. Declines in striatal dopamine uptake and transporter sites were also less severe than the reduction in dopamine levels, with enhanced dopamine turnover in the dorsolateral striatum after lesioning. The greatest degree of adaptation occurred for nicotine-evoked [(3)H]dopamine release from striatal synaptosomes, which was relatively intact in ventromedial striatum after lesioning, despite > 50% declines in dopamine. This maintenance of evoked release was not due to compensatory alterations in nicotinic receptor characteristics. Rather, there appeared to be a generalized preservation of release processes in ventromedial striatum, with K(+)-evoked release also near control levels after lesioning. These combined compensatory mechanisms help explain the finding that Parkinson's disease symptomatology develops only with major losses of striatal dopamine. 相似文献
70.
Samantha Baldwin Roopashree Revanna Meeghan Pither-Joyce Martin Shaw Kathryn Wright Susan Thomson Leire Moya Robyn Lee Richard Macknight John McCallum 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(3):535-547