31,671 research outputs found
Comparison of protein extraction methods suitable for proteomics analysis in seedling roots of Jerusalem artichoke under salt (NaCl) stress
An efficient protein extraction method is a prerequisite for successful implementation of proteomics. In this study, seedling roots of Jerusalem artichoke were treated with the concentration of 250 mM NaCl for 36 h. Subsequently, six different protocols of protein extraction were applied to seedling roots of Jerusalem artichoke for comparing extraction efficiency by conducting two-dimensional electrophoresis (2-DE). The first-dimensional electrophoresis was differently performed by using tube gel and immobilized pH gradient (IPG) strips, respectively. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the second dimension was equally carried out. The results indicated that precipitation of ammonium acetate in methanol after phenol extraction (Method 6) provided the best effect. Less impurity was contained in extracted proteins and the 2-DE gel images showed less horizontal and vertical stripes, the most proteineous spots were extracted on the basis of the protocol, up to 903. Trichloroacetic acid (TCA) method (Method 1) exhibited relative less quality gel images. 248 protein spots were only obtained according to the protocol and were the least among six protocols. Although, Mg/Nonidet P-40 (NP-40) methods (Methods 3 and 4) could extract a large number of proteins, it exhibited the worst quality gel images among all protocols and the horizontal and vertical stripes on the gel images were the most severe. It might be caused by a high salt content in extracted proteins.Key words: Proteomics, Jerusalem artichoke, roots, two-dimensional electrophoresis (2-DE), protocol, salt
Supersymmetry in Quantum Mechanics of Colored Particles
The role of supercharge operators is studied in the case of a Dirac particle
moving in a constant chromomagnetic field. The Hamiltonian is factorised and
the ground state wave function in the case of unbroken supersymmetry is
determined.Comment: 8 pages, no figure
Nonlocal Gravitational Models and Exact Solutions
A nonlocal gravity model with a function , where is
the d'Alembert operator, is considered. The algorithm, allowing to reconstruct
, corresponding to the given Hubble parameter and the state
parameter of the matter, is proposed. Using this algorithm, we find the
functions , corresponding to de Sitter solutions.Comment: 5 pages, v2: refs. added, to appear in the proceedings of the
International Workshop "Supersymmetries and Quantum Symmetries" (SQS'2011),
Dubna, Russia, July 18-23, 2011, http://theor.jinr.ru/sqs/2011
Design of a pulse power supply unit for micro-ECM
Electrochemical micro-machining (μECM) requires a particular pulse power supply unit (PSU) to be developed in order to achieve desired machining performance. This paper summarises the development of a pulse PSU meeting the requirements of μECM. The pulse power supply provides tens of nanosecond pulse duration, positive and negative bias voltages and a polarity switching functionality. It fulfils the needs for tool preparation with reversed pulsed ECM on the machine. Moreover, the PSU is equipped with an ultrafast overcurrent protection which prevents the tool electrode from being damaged in case of short circuits. The developed pulse PSU was used to fabricate micro-tools out of 170 μm WC-Co alloy shafts via micro-electrochemical turning and drill deep holes via μECM in a disk made of 18NiCr6. The electrolyte used for both processes was a mixture of sulphuric acid and NaNO3 aqueous solutions.The research reported in this paper is supported by the European Commission within the project “Minimizing Defects in Micro-Manufacturing Applications (MIDEMMA)” (FP7-2011-NMP-ICT-FoF-285614
Human settlement of the last glaciation on the Tibetan plateau
An archaeological site with 19 handprints and footprints of Homo sapiens and the remnant of a fireplace have been found on hot spring travertine at an elevation of 4200 m on the Tibetan plateau. The prints were pressed on soft travertine by humans. The age of the prints and fireplace is estimated to be around 20,000 years using the optically stimulated luminescence method. The result suggests that humans came to the plateau much earlier than was previously thought. This evidence of human settlement implies that the Tibetans occupy high plateau much earlier than the Andeans and the ice sheet did not cover the entire Tibetan plateau during the Last Glacial Maximum.published_or_final_versio
汉诺坝玄武岩中麻粒岩和辉石岩捕虏体Sr-Nd-Pb同位素五维空间特征及其地质意义
研究了汉诺坝玄武岩中麻粒岩和辉石岩捕虏体在Sr-Nd-Pb同位素五维空间中的特征 .结合捕虏体的空间分布相对位置, 认为层离作用可较好地解释不同类型捕虏体同位素之间的相互关系。published_or_final_versio
Atomic layer deposition of ZnS nanotubes
We report on growth of high-aspect-ratio () zinc sulfide
nanotubes with variable, precisely tunable, wall thicknesses and tube diameters
into highly ordered pores of anodic alumina templates by atomic layer
deposition (ALD) at temperatures as low as 75 C. Various
characterization techniques are employed to gain information on the
composition, morphology, and crystal structure of the synthesized samples.
Besides practical applications, the ALD-grown tubes could be envisaged as model
systems for the study of a certain class of size-dependent quantum and
classical phenomena.Comment: 1 LaTeX source file, 8 eps figures, and the manuscript in PDF forma
Deletion within the Src homology domain 3 of Bruton's tyrosine kinase resulting in X-linked agammaglobulinemia (XLA).
The gene responsible for X-linked agammaglobulinemia (XLA) has been recently identified to code for a cytoplasmic tyrosine kinase (Bruton's agammaglobulinemia tyrosine kinase, BTK), required for normal B cell development. BTK, like many other cytoplasmic tyrosine kinases, contains Src homology domains (SH2 and SH3), and catalytic kinase domain. SH3 domains are important for the targeting of signaling molecules to specific subcellular locations. We have identified a family with XLA whose affected members have a point mutation (g-->a) at the 5' splice site of intron 8, resulting in the skipping of coding exon 8 and loss of 21 amino acids forming the COOH-terminal portion of the BTK SH3 domain. The study of three generations within this kinship, using restriction fragment length polymorphism and DNA analysis, allowed identification of the mutant X chromosome responsible for XLA and the carrier status in this family. BTK mRNA was present in normal amounts in Epstein-Barr virus-induced B lymphoblastoid cell lines established from affected family members. Although the SH3 deletion did not alter BTK protein stability and kinase activity of the truncated BTK protein was normal, the affected patients nevertheless have a severe B cell defect characteristic for XLA. The mutant protein was modeled using the normal BTK SH3 domain. The deletion results in loss of two COOH-terminal beta strands containing several residues critical for the formation of the putative SH3 ligand-binding pocket. We predict that, as a result, one or more crucial SH3 binding proteins fail to interact with BTK, interrupting the cytoplasmic signal transduction process required for B cell differentiation
Atmospheric deposition of heavy metals in the Pearl River Delta, China
Author name used in this publication: C. S. C. WongAuthor name used in this publication: X. D. LiAuthor name used in this publication: G. ZhangAuthor name used in this publication: S. H. QiAuthor name used in this publication: X. Z. Peng2002-2003 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
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