226 research outputs found
Ground-state properties of neutron-rich Mg isotopes
We analyze recently-measured total reaction cross sections for 24-38Mg
isotopes incident on 12C targets at 240 MeV/nucleon by using the folding model
and antisymmetrized molecular dynamics(AMD). The folding model well reproduces
the measured reaction cross sections, when the projectile densities are
evaluated by the deformed Woods-Saxon (def-WS) model with AMD deformation.
Matter radii of 24-38Mg are then deduced from the measured reaction cross
sections by fine-tuning the parameters of the def-WS model. The deduced matter
radii are largely enhanced by nuclear deformation. Fully-microscopic AMD
calculations with no free parameter well reproduce the deduced matter radii for
24-36Mg, but still considerably underestimate them for 37,38Mg. The large
matter radii suggest that 37,38Mg are candidates for deformed halo nucleus. AMD
also reproduces other existing measured ground-state properties (spin-parity,
total binding energy, and one-neutron separation energy) of Mg isotopes.
Neutron-number (N) dependence of deformation parameter is predicted by AMD.
Large deformation is seen from 31Mg with N = 19 to a drip-line nucleus 40Mg
with N = 28, indicating that both the N = 20 and 28 magicities disappear. N
dependence of neutron skin thickness is also predicted by AMD.Comment: 15 pages, 13 figures, to be published in Phys. Rev.
Electrochemical Na-insertion/extraction properties of Sn-P anodes
Thick-film electrodes of tin phosphides, Sn4P3 and SnP3, were prepared using a mechanical alloying method followed by a gas-deposition method, and were evaluated as Na-ion battery anodes in an organic electrolyte and ionic liquid electrolytes. The Sn4P3 electrode showed a better cycling performance in the organic electrolyte compared with the SnP3 electrode and an Sn electrode. The performance of the Sn4P3 electrode was further improved by using ionic liquid electrolytes because of a uniformly formed surface layer and resulting uniform sodiation/desodiation reactions on the electrode
Adjuvant Antitumor Immunity Contributes to the Overall Antitumor Effect of Pegylated Liposomal Doxorubicin (Doxil®) in C26 Tumor-Bearing Immunocompetent Mice
Doxorubicin (DXR) has been reported to have direct cytotoxicity against cancer cells and indirect immunotoxicity by modulation of host antitumor immunity. Hence, it may prevent cancer progression by a dual mechanism. Doxil®, a formulation of DXR encapsulated in polyethylene glycol modified (PEGylated) liposomes, is the most widely used of the clinically approved liposomal anticancer drugs. However, the effect of Doxil® on host antitumor immunity is not well understood. In this study, Doxil® efficiently suppressed tumor growth in immunocompetent mice bearing C26 murine colorectal carcinomas, but not in T cell-deficient nude mice, indicating a contribution of T cells to the overall antitumor effect of Doxil®. In immunocompetent mice, Doxil® increased major histocompatibility complex (MHC-1) levels in C26 tumors, which may be an indicator of increased immunogenicity of tumor cells, and potentially amplified tumor immunogenicity by decreasing immunosuppressive cells such as regulatory T cells, tumor-associated microphages and myeloid-derived suppressor cells that collectively suppress T cell-mediated antitumor responses. This suggests that encapsulation of DXR into PEGylated liposomes increased the therapeutic efficacy of DXR though effects on host antitumor immunogenicity in addition to direct cytotoxic effects on tumor cells. This report describes the role of host antitumor immunity in the overall therapeutic effects of Doxil®. Manipulating pharmacokinetics and biodistribution of chemotherapeutic agents with immunomodulatory properties may increase their therapeutic efficacies by amplifying host antitumor immunity in addition to direct cytotoxic effects on tumor cells
Dominance in self-compatibility between subgenomes of allopolyploid Arabidopsis kamchatica shown by transgenic restoration of self-incompatibility
The evolutionary transition to self-compatibility facilitates polyploid speciation. In Arabidopsis relatives, the self-incompatibility system is characterized by epigenetic dominance modifiers, among which small RNAs suppress the expression of a recessive SCR/SP11 haplogroup. Although the contribution of dominance to polyploid self-compatibility is speculated, little functional evidence has been reported. Here we employ transgenic techniques to the allotetraploid plant A. kamchatica. We find that when the dominant SCR-B is repaired by removing a transposable element insertion, self-incompatibility is restored. This suggests that SCR was responsible for the evolution of self-compatibility. By contrast, the reconstruction of recessive SCR-D cannot restore self-incompatibility. These data indicate that the insertion in SCR-B conferred dominant self-compatibility to A. kamchatica. Dominant self-compatibility supports the prediction that dominant mutations increasing selfing rate can pass through Haldane’s sieve against recessive mutations. The dominance regulation between subgenomes inherited from progenitors contrasts with previous studies on novel epigenetic mutations at polyploidization termed genome shock
A functional genomics tool for the Pacific bluefin tuna: Development of a 44K oligonucleotide microarray from whole-genome sequencing data for global transcriptome analysis
AbstractBluefin tunas are one of the most important fishery resources worldwide. Because of high market values, bluefin tuna farming has been rapidly growing during recent years. At present, the most common form of the tuna farming is based on the stocking of wild-caught fish. Therefore, concerns have been raised about the negative impact of the tuna farming on wild stocks. Recently, the Pacific bluefin tuna (PBT), Thunnus orientalis, has succeeded in completing the reproduction cycle under aquaculture conditions, but production bottlenecks remain to be solved because of very little biological information on bluefin tunas. Functional genomics approaches promise to rapidly increase our knowledge on biological processes in the bluefin tuna. Here, we describe the development of the first 44K PBT oligonucleotide microarray (oligo-array), based on whole-genome shotgun (WGS) sequencing and large-scale expressed sequence tags (ESTs) data. In addition, we also introduce an initial 44K PBT oligo-array experiment using in vitro grown peripheral blood leukocytes (PBLs) stimulated with immunostimulants such as lipopolysaccharide (LPS: a cell wall component of Gram-negative bacteria) or polyinosinic:polycytidylic acid (poly I:C: a synthetic mimic of viral infection). This pilot 44K PBT oligo-array analysis successfully addressed distinct immune processes between LPS- and poly I:C- stimulated PBLs. Thus, we expect that this oligo-array will provide an excellent opportunity to analyze global gene expression profiles for a better understanding of diseases and stress, as well as for reproduction, development and influence of nutrition on tuna aquaculture production
Novel extrapancreatic effects of incretin
The hormonal factors implicated as transmitters of signals from the gut to pancreatic -cells are referred to as incretins. Gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are incretins. In addition to the insulinotropic effects, we have shown, using the GIP receptor and GLP-1 receptor-deficient mice, that GIP and GLP-1 have direct actions on adipocytes and the kidney, respectively. Because GIP receptors and GLP-1 receptors are differentially expressed in a tissue-specific manner, GIP and GLP-1 have specific physiological activities, and further comprehensive characterization of the extrapancreatic actions of GIP and GLP-1 is anticipated, as dipeptidyl peptidaseIV inhibitors activate both GIP and GLP-1 signaling
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