165 research outputs found

    Efficient Agrobacterium tumefaciens -mediated transformation of Malus zumi (Matsumura) Rehd using leaf explant regeneration system

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    Malus zumi is known as an excellent dwarfing apple rootstock occurring in natural or arid/semiarid soil or salina. Gene manipulation of M. zumi through transgenic technology can modify plant feature for further improvement fruit tree production by grafting the scion on a transgenic rootstock. Here, we report the establishment of an efficient, in vitro, shoot regeneration system and Agrobacterium tumefaciens - mediated transformation from the leaf explants for Malus zumi (Matsumura) Rehd. Leaf explants were infected with Agrobacterium strains containing nptII and gus gene. The highest frequency of shoot regeneration was obtained on MS medium containing 500 mg l-1 Lactalbumin hydrolysate, 30 g l-1 fructose, supplemented with 3.0 mg l-1 BA, 0.2 mg l-1 NAA.Using fructose instead of sucrose significantly increases the shoot regeneration and decreases vitrification. This regeneration procedure was incorporated into an Agrobacterium-mediated transformation procedure in M. zumi. Kanamycin was an efficient selective agent for selection. Pre-selection (5 days after co-cultivation) improved the transformation efficiency. The emergence of expected bands by PCR analysis and Southern blot in transgenic plantlets confirmed the transformation of foreign DNA into plant genome

    The Supersymmetric Standard Models with Decay and Stable Dark Matters

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    We propose two supersymmetric Standard Models (SMs) with decaying and stable dark matter (DM) particles. To explain the SM fermion masses and mixings and have a heavy decay DM particle S, we consider the Froggatt-Nielsen mechanism by introducing an anomalous U(1)_X gauge symmetry. Around the string scale, the U(1)_X gauge symmetry is broken down to a Z_2 symmetry under which S is odd while all the SM particles are even. S obtains a vacuum expectation value around the TeV scale, and then it can three-body decay dominantly to the second/third family of the SM leptons in Model I and to the first family of the SM leptons in Model II. Choosing a benchmark point in the constrained minimal supersymmetric SM with exact R parity, we show that the lightest neutralino DM is consistent with the CDMS II experiment. Considering S three-body decay and choosing suitable parameters, we show that the PAMELA and Fermi-LAT experiments and the PAMELA and ATIC experiments can be explained in Model I and Model II, respectively.Comment: RevTex4, 26 pages, 6 figures, references added, version to appear in EPJ

    Higher algebraic KK-groups and D\mathcal D-split sequences

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    In this paper, we use D\mathcal D-split sequences and derived equivalences to provide formulas for calculation of higher algebraic KK-groups (or mod-pp KK-groups) of certain matrix subrings which cover tiled orders, rings related to chains of Glaz-Vasconcelos ideals, and some other classes of rings. In our results, we do not assume any homological requirements on rings and ideals under investigation, and therefore extend sharply many existing results of this type in the algebraic KK-theory literature to a more general context.Comment: 20 page

    ZnO Nanorods via Spray Deposition of Solutions Containing Zinc Chloride and Thiocarbamide

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    In this work we present the results on formation of ZnO nanorods prepared by spray of aqueous solutions containing ZnCl2and thiocarbamide (tu) at different molar ratios. It has been observed that addition of thiocarbamide into the spray solution has great impact on the size, shape and phase composition of the ZnO crystals. Obtained layers were characterized by scanning electron microscopy (SEM) equipped with energy selected backscattered electron detection system (ESB), X-ray diffraction (XRD) and photoluminescence spectroscopy (PL). Small addition of thiocarbamide into ZnCl2solution (ZnCl2:tu = 1:0.25) supports development of significantly thinner ZnO nanorods with higher aspect ratio compared to those obtained from ZnCl2solution. Diameter of ZnO rods decreases from 270 to 100 nm and aspect ratio increases from ∼2.5 to 12 spraying ZnCl2and ZnCl2:tu solutions, respectively. According to XRD, well crystallized (002) orientated pure wurtzite ZnO crystals have been formed. However, tiny ‘spot’—like formations of ZnS were detected on the side planes of hexagonal rods prepared from the thiocarbamide containing solutions. Being adsorbed on the side facets of the crystals ZnS inhibits width growth and promotes longitudinalc-axis growth

    Resolving Fermi, PAMELA and ATIC anomalies in split supersymmetry without R-parity

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    A long-lived decaying dark matter as a resolution to Fermi, PAMELA and ATIC anomalies is investigated in the framework of split supersymmetry (SUSY) without R-parity, where the neutralino is regarded as the dark matter and the extreme fine-tuned couplings for the long-lived neutralino are naturally evaded in the usual approach.Comment: 14 pages, 6 figures. Erroneous results concerning the cascade processes removed. Main results unchange

    Prunella vulgaris: A comprehensive review of chemical constituents, pharmacological effects and clinical applications.

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    Prunella vulgaris (PV) is a perennial herb belonging to the Labiate family and is widely distributed in northeastern Asian countries such as Korea, Japan, and China. It is reported to display diverse biological activities including anti-microbial, anti-cancer, and anti-inflammation as determined by in vitro or in vivo studies. So far, about 200 compounds have been isolated from PV plant and majority of these have been characterized mainly as triterpenoids, sterols and flavonoids, followed by coumarins, phenylpropanoids, polysaccharides and volatile oils. This review summarizes and analyzes the current knowledge on the chemical constituents, pharmacological activities, mechanisms of action and clinical applications of the PV plant including its potential as a future medicinal plant. Although some of the chemical constituents of the PV plant and their mechanism of action have been investigated the biological activities of many of these remain unknown and further clinical trials are required to further enhance its reputation as a medicinal plant

    Strategies for Controlled Placement of Nanoscale Building Blocks

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    The capability of placing individual nanoscale building blocks on exact substrate locations in a controlled manner is one of the key requirements to realize future electronic, optical, and magnetic devices and sensors that are composed of such blocks. This article reviews some important advances in the strategies for controlled placement of nanoscale building blocks. In particular, we will overview template assisted placement that utilizes physical, molecular, or electrostatic templates, DNA-programmed assembly, placement using dielectrophoresis, approaches for non-close-packed assembly of spherical particles, and recent development of focused placement schemes including electrostatic funneling, focused placement via molecular gradient patterns, electrodynamic focusing of charged aerosols, and others
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