全文获取类型
收费全文 | 91篇 |
免费 | 4篇 |
国内免费 | 1篇 |
出版年
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 5篇 |
2010年 | 11篇 |
2009年 | 8篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有96条查询结果,搜索用时 46 毫秒
1.
The signal produced by fluorescence in situ hybridization (FISH) often is inconsistent among cells and sensitivity is low. Small DNA targets on the chromatin are difficult to detect. We report here an improved nick translation procedure for Texas red and Alexa Fluor 488 direct labeling of FISH probes. Brighter probes can be obtained by adding excess DNA polymerase I. Using such probes, a 30?kb yeast transgene, and the rp1, rp3 and zein multigene clusters were clearly detected. 相似文献
2.
A.J.E. Pedro P.S. Fevereiro M.L. Serralheiro M.R. Aires-Barros 《Biocatalysis and Biotransformation》2013,31(2):129-135
The stability of a cationic peroxidase isolated and purified from a cell suspension of Vaccinium myrtillus, microencapsulated in reverse micelles of sodium dioctylsulfosuccinate (AOT) was evaluated. By using a central composite design (CCD), some relevant parameters for the enzymatic activity, such as surfactant and water concentration, pH and buffer molarity, were analysed. The response surface curves showed that 50 mM AOT, 500 mM water, 80 mM buffer and pH 7.6 were the best conditions for enzyme stability. The effect of carbohydrates and polyols on enzyme stability was also evaluated. At 20 mM, carbohydrates like arabinose, and trehalose increased the enzymatic stability by a factor of 4.4 and 2.3, respectively, but melezitose had no effect. From the three polyols tested, inositol and sorbitol increased the peroxidase stability by a factor of 3.8 and 1.8, respectively, while mannitol had no effect. 相似文献
3.
Cátia Nunes Henriette Schluepmann Thierry L Delatte Astrid Wingler Anabela B Silva Pedro S Fevereiro Marcus Jansen Fabio Fiorani Anika Wiese-Klinkenberg Matthew J Paul 《Plant signaling & behavior》2013,8(12)
Carbon signaling can override carbon supply in the regulation of growth. At least some of this regulation is imparted by the sugar signal trehalose 6-phosphate (T6P) through the protein kinase, SnRK1. This signaling pathway regulates biosynthetic processes involved in growth under optimal growing conditions. Recently, using a seedling system we showed that under sub-optimal conditions, such as cold, carbon signaling by T6P/ SnRK1 enables recovery of growth following relief of the stress. The T6P/ SnRK1 mechanism thus could be selected as a means of improving low temperature tolerance. High-throughput automated Fv/Fm measurements provide a potential means to screen for T6P/ SnRK1, and here we confirm through measurements of Fv/Fm in rosettes that T6P promotes low temperature tolerance and recovery during cold to warm transfer. Further, to better understand the coordination between sugars, trehalose pathway, and temperature-dependent growth, we examine the interrelationship between sugars, trehalose phosphate synthase (TPS), and trehalose phosphate phosphatase (TPP) gene expression and T6P content in seedlings. Sucrose, particularly when fed exogenously, correlated well with TPS1 and TPPB gene expression, suggesting that these enzymes are involved in maintaining carbon flux through the pathway in relation to sucrose supply. However, when sucrose accumulated to higher levels under low temperature and low N, TPS1 and TPPB expression were less directly related to sucrose; other factors may also contribute to regulation of TPS1 and TPPB expression under these conditions. TPPA expression was not related to sucrose content and all genes were not well correlated with endogenous glucose. Our work has implications for understanding acclimation to sink-limited growth conditions such as low temperature and for screening cold-tolerant genotypes with altered T6P/ SnRK1 signaling. 相似文献
4.
Uxmal and Tulum are two important Mayan sites in the Yucatan peninsula. The buildings are mainly composed of limestone and grey/black discoloration is seen on exposed walls and copious greenish biofilms on inner walls. The principal microorganisms detected on interior walls at both Uxmal and Tulum were cyanobacteria; heterotrophic bacteria and filamentous fungi were also present. A dark‐pigmented mitosporic fungus and Bacillus cereus, both isolated from Uxmal, were shown to be acidogenic in laboratory cultures. Cyanobacteria belonging to rock‐degrading genera Synechocystis and Gloeocapsa were identified at both sites. Surface analysis previously showed that calcium ions were present in the biofilms on buildings at Uxmal and Tulum, suggesting the deposition of biosolubilized stone. Apart from their potential to degrade the substrate, the coccoid cyanobacteria supply organic nutrients for bacteria and fungi, which can produce organic acids, further increasing stone degradation. 相似文献
5.
S. S. Araújo A. S. Duque J. M. Silva D. Santos A. B. Silva P. Fevereiro 《Biologia Plantarum》2013,57(1):159-163
In this article, we present the response of Medicago truncatula Gaert. cv. Jemalong plants expressing constitutively the Dsp22 gene from Craterostigma plantagineum to water stress and rehydration. The Dsp22 gene encodes an ELIP-like protein thought to protect the chloroplast against photooxidative damage during the dehydration and rehydration. The Dsp22 transgenic homozygous M. truncatula plants showed higher amount of chlorophyll (Chl), lower Chl a/Chl b ratio and higher actual efficiency of energy conversion in photosystem 2 (ΦPSII) after rehydration, when compared to the wild type. The combined data from the Chl a fluorescence analysis, pigment quantification and biomass accumulation showed that transgenic M. truncatula plants are able to recover from water deprivation better than wild type plants. 相似文献
6.
7.
Background
One of the major challenges in the field of vaccine design is to predict conformational B-cell epitopes in an antigen. In the past, several methods have been developed for predicting conformational B-cell epitopes in an antigen from its tertiary structure. This is the first attempt in this area to predict conformational B-cell epitope in an antigen from its amino acid sequence.Results
All Support vector machine (SVM) models were trained and tested on 187 non-redundant protein chains consisting of 2261 antibody interacting residues of B-cell epitopes. Models have been developed using binary profile of pattern (BPP) and physiochemical profile of patterns (PPP) and achieved a maximum MCC of 0.22 and 0.17 respectively. In this study, for the first time SVM model has been developed using composition profile of patterns (CPP) and achieved a maximum MCC of 0.73 with accuracy 86.59%. We compare our CPP based model with existing structure based methods and observed that our sequence based model is as good as structure based methods.Conclusion
This study demonstrates that prediction of conformational B-cell epitope in an antigen is possible from is primary sequence. This study will be very useful in predicting conformational B-cell epitopes in antigens whose tertiary structures are not available. A web server CBTOPE has been developed for predicting B-cell epitope http://www.imtech.res.in/raghava/cbtope/. 相似文献8.
9.
André M. Almeida Enrique Villalobos Susana S. Araújo Luis A. Cardoso Dulce M. Santos Maria A. Santos Pedro S. Fevereiro José M. Torné 《Acta Physiologiae Plantarum》2007,29(3):273-281
Trehalose is a non-reducing disaccharide of glucose that occurs in a large number of organisms, playing an important role
in desiccation and heat stress protection. Trehalose accumulation has proven to be an effective way of increasing drought
tolerance in both model plants such as tobacco and important crops such as potato or rice. In this work we aim to genetically
engineer maize with the Arabidopsis thaliana trehalose phosphate synthase gene (AtTPS1), involved in trehalose biosynthesis via electroporation. A cassette harboring the
AtTPS1 gene under the control of the CaMV35S promoter and the Bialaphos resistance gene Bar as a selective agent was inserted
in the plasmid vector pGreen0229 and used to transform maize inbred line Pa91 via electroporation. Fifteen putative transgenic
plants (T0 generation) were obtained. Transgene integration in T0 plants was analyzed by Southern-blot analysis. T0 plants
had normal phenotypes, although smaller than wild type plants. Contrary to wild type plants, when sexual organs emerged, tassels
appeared at least 15 days earlier than ears in the same plant, rendering impossible the self-pollination of the T0 plant.
These plants were then crossed with wild type plants and in some cases T1 seeds were obtained. T1 seeds presented deformities,
especially the lack of endosperm, but it was still possible to germinate some of these seeds. The so obtained plants were
tested by Northern blot but no AtTPS1 gene expression was detected, a fact possibly due to the incomplete insertion of the
AtTPS1 gene or an extremely low gene expression level. 相似文献
10.
André M. Almeida Luís A. Cardoso Dulce M. Santos José M. Torné Pedro S. Fevereiro 《In vitro cellular & developmental biology. Plant》2007,43(3):167-177
Trehalose, a nonreducing disaccharide of glucose, is one of the most effective osmoprotectants. Several strategies leading
to its accumulation have been envisaged in both model and crop plants using genes of bacterial, yeast and, more recently,
plant origin. Significant levels of trehalose accumulation have been shown to cause abiotic stress tolerance in transgenic
plants. In this review, we describe the most biologically relevant features of trehalose: chemical and biological properties;
occurrence and metabolism in organisms with special reference to plants; protective role in stabilizing molecules; physiological
role in plants with special reference to carbohydrate metabolism. The emphasis of this review, however, will be on manipulation
of trehalose metabolism to improve abiotic stress tolerance in plants. 相似文献