594 research outputs found

    Effects of Metal Hydride Coatings at the Electrodes on Neutron Production Rate in a Discharge-Type Fusion Neutron Source

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    A glow discharge (GD) fusion neutron source that utilizes nuclear fusion reactions of deuterium has been upgraded. The fusion reactions in this device mainly occur by collisions between the charged or neutral particles and the hydrogen isotopes trapped at the surface of electrodes. In addition, it is known that the metal hydride coating on the electrode enhances the neutron production rate (NPR). Therefore, the elemental distribution, including deuterium, in the depth direction on the electrode is an essential factor in neutron production. However, the distribution on the electrode has not been experimentally investigated. This study aims to analyze the distribution experimentally and indicate the effect of the metal hydride coatings. To achieve this purpose, we prepared the titanium (Ti)-coated cathode and the uncoated cathode, of which the base material was stainless steel. After that, the neutron production test was performed in the range of from 5-to 40-mA currents and from 20-to 60-kV applied voltage. This test indicated that the NPR was improved by coating the cathode with Ti than the uncoated cathode. In addition, depth profiling on the cathodes by glow discharge optical emission spectroscopy (GD-OES) was performed. While the analysis indicated that the concentration of deuterium on both cathodes was increased after the test, there was no significant difference in the concentration of deuterium between both cathodes. Furthermore, the concentration of Ti on the Ti-coated cathode was vastly decreased. The cause of these changes needs to be investigated

    Tbx20 Is Required in Mid-Gestation Cardiomyocytes and Plays a Central Role in Atrial Development.

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    RationaleMutations in the transcription factor TBX20 (T-box 20) are associated with congenital heart disease. Germline ablation of Tbx20 results in abnormal heart development and embryonic lethality by embryonic day 9.5. Because Tbx20 is expressed in multiple cell lineages required for myocardial development, including pharyngeal endoderm, cardiogenic mesoderm, endocardium, and myocardium, the cell type-specific requirement for TBX20 in early myocardial development remains to be explored.ObjectiveHere, we investigated roles of TBX20 in midgestation cardiomyocytes for heart development.Methods and resultsAblation of Tbx20 from developing cardiomyocytes using a doxycycline inducible cTnTCre transgene led to embryonic lethality. The circumference of developing ventricular and atrial chambers, and in particular that of prospective left atrium, was significantly reduced in Tbx20 conditional knockout mutants. Cell cycle analysis demonstrated reduced proliferation of Tbx20 mutant cardiomyocytes and their arrest at the G1-S phase transition. Genome-wide transcriptome analysis of mutant cardiomyocytes revealed differential expression of multiple genes critical for cell cycle regulation. Moreover, atrial and ventricular gene programs seemed to be aberrantly regulated. Putative direct TBX20 targets were identified using TBX20 ChIP-Seq (chromatin immunoprecipitation with high throughput sequencing) from embryonic heart and included key cell cycle genes and atrial and ventricular specific genes. Notably, TBX20 bound a conserved enhancer for a gene key to atrial development and identity, COUP-TFII/Nr2f2 (chicken ovalbumin upstream promoter transcription factor 2/nuclear receptor subfamily 2, group F, member 2). This enhancer interacted with the NR2F2 promoter in human cardiomyocytes and conferred atrial specific gene expression in a transgenic mouse in a TBX20-dependent manner.ConclusionsMyocardial TBX20 directly regulates a subset of genes required for fetal cardiomyocyte proliferation, including those required for the G1-S transition. TBX20 also directly downregulates progenitor-specific genes and, in addition to regulating genes that specify chamber versus nonchamber myocardium, directly activates genes required for establishment or maintenance of atrial and ventricular identity. TBX20 plays a previously unappreciated key role in atrial development through direct regulation of an evolutionarily conserved COUPT-FII enhancer

    Exposição de Tilápia do Nilo (Oreochromis niloticus) ao herbicida de cana-de-açúcar hexazinona + diuron.

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    O objetivo deste trabalho foi avaliar a exposição de tilápias do Nilo ao hexazinona + diuron em duas etapas

    Soundness of Unravelings for Conditional Term Rewriting Systems via Ultra-Properties Related to Linearity

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    Unravelings are transformations from a conditional term rewriting system (CTRS, for short) over an original signature into an unconditional term rewriting systems (TRS, for short) over an extended signature. They are not sound w.r.t. reduction for every CTRS, while they are complete w.r.t. reduction. Here, soundness w.r.t. reduction means that every reduction sequence of the corresponding unraveled TRS, of which the initial and end terms are over the original signature, can be simulated by the reduction of the original CTRS. In this paper, we show that an optimized variant of Ohlebusch's unraveling for a deterministic CTRS is sound w.r.t. reduction if the corresponding unraveled TRS is left-linear or both right-linear and non-erasing. We also show that soundness of the variant implies that of Ohlebusch's unraveling. Finally, we show that soundness of Ohlebusch's unraveling is the weakest in soundness of the other unravelings and a transformation, proposed by Serbanuta and Rosu, for (normal) deterministic CTRSs, i.e., soundness of them respectively implies that of Ohlebusch's unraveling.Comment: 49 pages, 1 table, publication in Special Issue: Selected papers of the "22nd International Conference on Rewriting Techniques and Applications (RTA'11)

    Comparative virus replication and host innate responses in human cells infected with three prevalent clades (2.3.4, 2.3.2, and 7) of highly pathogenic avian influenza H5N1 viruses

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    Highly pathogenic avian influenza H5N1 virus clades 2.3.4, 2.3.2, and 7 are the dominant cocirculating H5N1 viruses in poultry in China. However, humans appear to be clinically susceptible mostly to the 2.3.4 virus clade. Here, we demonstrated that A549 cells and human macrophages infected with clade 2.3.4 viruses produced significantly more viruses than those infected with the other two clades. Likewise, clade 2.3.4-infected macrophages caused the most severe cellular damage and strongest proinflammatory response

    Variáveis hematológicas em tambaquis anestesiados com óleo de cravo e benzocaína.

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    O objetivo deste trabalho foi avaliar o efeito anestésico de óleo de cravo e benzocaína sobre os parâmetros hematológicas e a fragilidade osmótica dos eritrócitos em tambaqui (Colossoma macropomum)

    Path Integral Approach to the Non-Relativistic Electron Charge Transfer

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    A path integral approach has been generalized for the non-relativistic electron charge transfer processes. The charge transfer - the capture of an electron by an ion passing another atom or more generally the problem of rearrangement collisions is formulated in terms of influence functionals. It has been shown that the electron charge transfer process can be treated either as electron transition problem or as elastic scattering of ion and atom in the some effective potential field. The first-order Born approximation for the electron charge transfer cross section has been reproduced to prove the adequacy of the path integral approach for this problem.Comment: 19 pages, 1 figure, to appear in Journal of Physics B: Atomic, Molecular & Optical, vol.34, 200

    YAP/TAZ-CDC42 signaling regulates vascular tip cell migration

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    Angiogenesis and vascular remodeling are essential for the establishment of vascular networks during organogenesis. Here we show that the Hippo signaling pathway effectors YAP and TAZ are required, in a gene dosage-dependent manner, for the proliferation and migration of vascular endothelial cells (ECs) during retinal angiogenesis. Intriguingly, nuclear translocation of YAP and TAZ induced by Lats1/2-deletion blocked endothelial migration and phenocopied Yap/Taz-deficient mutants. Furthermore, overexpression of a cytoplasmic form of YAP (YAPS127D) partially rescued the migration defects caused by loss of YAP and TAZ function. Finally, we found that cytoplasmic YAP positively regulated the activity of the small GTPase CDC42, deletion of which caused severe defects in endothelial migration. These findings uncover a previously unrecognized role of cytoplasmic YAP/TAZ in promoting cell migration by activating CDC42 and provide insight into how Hippo signaling in ECs regulates angiogenesis

    Efeito de diferentes estressores sobre os parâmetros hematológicos e bioquímicos de tambaqui Colossoma macropomum.

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    Este estudo teve por objetivo avaliar as alterações hematológicas e bioquímicas determinadas pelo estresse por captura, com exposição aérea e por adensamento em tambaqui
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