排序方式: 共有171条查询结果,搜索用时 31 毫秒
41.
Stefaan Rossenu Daisy Dewitte Joël Vandekerckhove Christophe Ampe 《The protein journal》1997,16(5):499-503
Phage display is a technique in which a foreign protein or peptide is presented at the surface of a (filamentous) bacteriophage. This system, developed by Smith [(1985), Science 228, 1315–1317], was originally used to create large libraries of antibodies for the purpose of selecting those that strongly bound a particular antigen. More recently it was also employed to present peptides, domains of proteins, or intact proteins at the surface of phages, again to identify high-affinity interactions with ligands. Here we want to illustrate the use of phage display, in combination with PCR saturation mutagenesis, for the study of protein–protein interactions. Rather than selecting for mutants having high affinity, we systematically investigate the binding of every variant with its natural ligand. Via a modified ELISA we can calculate a relative affinity. As a model system we chose to display thymosin β4 on the phage surface in order to study its interaction with actin. 相似文献
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A Low Resistance Calcium/Reduced Titania Passivated Contact for High Efficiency Crystalline Silicon Solar Cells 下载免费PDF全文
Thomas G. Allen James Bullock Quentin Jeangros Christian Samundsett Yimao Wan Jie Cui Aïcha Hessler‐Wyser Stefaan De Wolf Ali Javey Andres Cuevas 《Liver Transplantation》2017,7(12)
Recent advances in the efficiency of crystalline silicon (c‐Si) solar cells have come through the implementation of passivated contacts that simultaneously reduce recombination and resistive losses within the contact structure. In this contribution, low resistivity passivated contacts are demonstrated based on reduced titania (TiOx) contacted with the low work function metal, calcium (Ca). By using Ca as the overlying metal in the contact structure we are able to achieve a reduction in the contact resistivity of TiOx passivated contacts of up to two orders of magnitude compared to previously reported data on Al/TiOx contacts, allowing for the application of the Ca/TiOx contact to n‐type c‐Si solar cells with partial rear contacts. Implementing this contact structure on the cell level results in a power conversion efficiency of 21.8% where the Ca/TiOx contact comprises only ≈6% of the rear surface of the solar cell, an increase of 1.5% absolute compared to a similar device fabricated without the TiOx interlayer. 相似文献
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Ibraheem Adetunji Glenda Willems Hendrik Tschoep Alexandra Bürkholz Steve Barnes Martin Boer Marcos Malosetti Stefaan Horemans Fred van Eeuwijk 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2014,127(3):559-571
Key message
Linkage disequilibrium decay in sugar beet is strongly affected by the breeding history, and varies extensively between and along chromosomes, allowing identification of known and unknown signatures of selection.Abstract
Genetic diversity and linkage disequilibrium (LD) patterns were investigated in 233 elite sugar beet breeding lines and 91 wild beet accessions, using 454 single nucleotide polymorphisms (SNPs) and 418 SNPs, respectively. Principal coordinate analysis suggested the existence of three groups of germplasm, corresponding to the wild beets, the seed parent and the pollen parent breeding pool. LD was investigated in each of these groups, with and without correction for genetic relatedness. Without correction for genetic relatedness, in the pollen as well as the seed parent pool, LD persisted beyond 50 centiMorgan (cM) on four (2, 3, 4 and 5) and three chromosomes (2, 4 and 6), respectively; after correction for genetic relatedness, LD decayed after <6 cM on all chromosomes in both pools. In the wild beet accessions, there was a strong LD decay: on average LD disappeared after 1 cM when LD was calculated with a correction for genetic relatedness. Persistence of LD was not only observed between distant SNPs on the same chromosome, but also between SNPs on different chromosomes. Regions on chromosomes 3 and 4 that harbor disease resistance and monogermy loci showed strong genetic differentiation between the pollen and seed parent pools. Other regions, on chromosomes 8 and 9, for which no a priori information was available with respect to their contribution to the phenotype, still contributed to clustering of lines in the elite breeding material. 相似文献46.
Xinbo Yang Erkan Aydin Hang Xu Jingxuan Kang Mohamed Hedhili Wenzhu Liu Yimao Wan Jun Peng Christian Samundsett Andres Cuevas Stefaan De Wolf 《Liver Transplantation》2018,8(20)
Minimizing carrier recombination at contact regions by using carrier‐selective contact materials, instead of heavily doping the silicon, has attracted considerable attention for high‐efficiency, low‐cost crystalline silicon (c‐Si) solar cells. A novel electron‐selective, passivating contact for c‐Si solar cells is presented. Tantalum nitride (TaN x ) thin films deposited by atomic layer deposition are demonstrated to provide excellent electron‐transporting and hole‐blocking properties to the silicon surface, due to their small conduction band offset and large valence band offset. Thin TaNx interlayers provide moderate passivation of the silicon surfaces while simultaneously allowing a low contact resistivity to n‐type silicon. A power conversion efficiency (PCE) of over 20% is demonstrated with c‐Si solar cells featuring a simple full‐area electron‐selective TaNx contact, which significantly improves the fill factor and the open circuit voltage (Voc) and hence provides the higher PCE. The work opens up the possibility of using metal nitrides, instead of metal oxides, as carrier‐selective contacts or electron transport layers for photovoltaic devices. 相似文献
47.
Stefaan P. O. Werbrouck Bruno van der Jeugt Walter Dewitte Els Prinsen Harry A. Van Onckelen Pierre C. Debergh 《Plant cell reports》1995,14(10):662-665
In Spathiphyllum floribundum Petite, which was cultured on medium containing benzyladenine (BA), uptake of this cytokinin and its conversion to 9-ß-D-ribofuranosyl-benzyladenine (9R-BA) or 9-ß-glucopyranosyl-benzyladenine (9G-BA) was monitored. BA and extremely large quantities of 9G-BA were exclusively located in the basal part of the plant (callus and meristems). 9R-BA was found in the basal part, the petioles and the leaf blades. After an acclimatisation period of 9 weeks the plants still contained high levels of 9G-BA, but BA and 9R-BA could no longer be detected after one week. The possible role of BA and its derivatives on inhibition of root initiation or irreversible chloroplast deficiency is discussed.Abbreviations 3G-BA
3-ß-glucopyranosyl-benzyladenine
- 7G-BA
7-ß-glucopyranosyl-benzyladenine
- 9G-BA
9-ß-glucopyranosyl-benzyladenine
- 9R-BA
9-ß-D-ribofuranosyl-benzyladenine
- au
absorption units
- HPLC
high-performance liquid chromatography
- LC-MS
liquid chromatography—mass spectrometry
- MeOH
methanol
- NaFeEDTA
ethylenediaminetetra-acetic acid
- NH4Ac
ammonium acetate
- PAR
photo-synthetic active radiation
- UV
ultra-violet 相似文献
48.
Stefaan Rossenu Daisy Dewitte Joël Vandekerckhove Christophe Ampe 《Journal of Protein Chemistry》1997,16(5):499-503
Phage display is a technique in which a foreign protein or peptide is presented at the surface of a (filamentous) bacteriophage. This system, developed by Smith [(1985), Science
228, 1315–1317], was originally used to create large libraries of antibodies for the purpose of selecting those that strongly bound a particular antigen. More recently it was also employed to present peptides, domains of proteins, or intact proteins at the surface of phages, again to identify high-affinity interactions with ligands. Here we want to illustrate the use of phage display, in combination with PCR saturation mutagenesis, for the study of protein–protein interactions. Rather than selecting for mutants having high affinity, we systematically investigate the binding of every variant with its natural ligand. Via a modified ELISA we can calculate a relative affinity. As a model system we chose to display thymosin 4 on the phage surface in order to study its interaction with actin. 相似文献
49.
Four decades of post-agricultural forest development have caused major redistributions of soil phosphorus fractions 总被引:3,自引:0,他引:3
De Schrijver A Vesterdal L Hansen K De Frenne P Augusto L Achat DL Staelens J Baeten L De Keersmaeker L De Neve S Verheyen K 《Oecologia》2012,169(1):221-234
Fertilisation of agricultural land causes an accumulation of nutrients in the top soil layer, among which phosphorus (P) is particularly persistent. Changing land use from farmland to forest affects soil properties, but changes in P pools have rarely been studied despite their importance to forest ecosystem development. Here, we describe the redistributions of the P pools in a four-decadal chronosequence of post-agricultural common oak (Quercus robur L.) forests in Belgium and Denmark. The aim was to assess whether forest age causes a repartitioning of P throughout the various soil P pools (labile P, slowly cycling P and occluded P); in particular, we addressed the time-related alterations in the inorganic versus organic P fractions. In less than 40 years of oak forest development, significant redistributions have occurred between different P fractions. While both the labile and the slowly cycling inorganic P fractions significantly decreased with forest age, the organic fractions significantly increased. The labile P pool (inorganic + organic), which is considered to be the pool of P most likely to contribute to plant-available P, significantly decreased with forest age (from >20 to <10% of total P), except in the 0-5 cm of topsoil, where labile P remained persistently high. The shift from inorganic to organic P and the shifts between the different inorganic P fractions are driven by biological processes and also by physicochemical changes related to forest development. It is concluded that the organic labile P fraction, which is readily mineralisable, should be taken into account when studying the bioavailable P pool in forest ecosystems. 相似文献
50.
Veronique Troch Stefaan Werbrouck Danny Geelen Marie-Christine Van Labeke 《Plant Cell, Tissue and Organ Culture》2009,98(1):115-123
Factors affecting conversion of horse chestnut (A. hippocastanum L.) somatic embryos into plantlets were evaluated. Anther filament derived embryogenic tissue developed bipolar structures
with two cotyledons and a well-developed shoot and root apical meristem upon auxin omittance from the culturing medium. The
impact of carbohydrate type (glucose, fructose, sucrose and maltose) and concentration (3 and 6%) on somatic embryo maturation
and conversion were evaluated. Although conversion frequencies were high for all treatments, overall quality of regenerated
plantlets was poor. Increasing the carbohydrate concentration in the maturation medium did not increase conversion of somatic
embryos or quality of regenerated plantlets in terms of shoot height. On the contrary, addition of PEG (polyethylene glycol)
in maturation media had a beneficial effect on shoot quality of regenerated plantlets. Sucrose was a superior carbon source
when PEG was included in the maturation medium, in terms of conversion rate (65.7%) as well as of shoot quality of plantlets
(43.8% of plantlets had shoots >2 cm). Clonal fidelity of the different development stages of somatic embryogenesis and of
converted plantlets was assessed by flow cytometry and no major ploidy changes were found. 相似文献