11,743 research outputs found

    Full-Coupled Channel Approach to Doubly Strange ss-Shell Hypernuclei

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    We describe {\it ab initio} calculations of doubly strange, S=2S=-2, ss-shell hypernuclei (ΛΛ4^4_{\Lambda\Lambda}H, ΛΛ5^5_{\Lambda\Lambda}H, ΛΛ5^5_{\Lambda\Lambda}He and ΛΛ6^6_{\Lambda\Lambda}He) as a first attempt to explore the few-body problem of the {\it full}-coupled channel scheme for these systems. The wave function includes ΛΛ\Lambda\Lambda, ΛΣ\Lambda\Sigma, NΞN\Xi and ΣΣ\Sigma\Sigma channels. Minnesota NNNN, D2^\prime YNYN, and simulated YYYY potentials based on the Nijmegen hard-core model, are used. Bound state solutions of these systems are obtained. We find that a set of phenomenological B8B8B_8B_8 interactions among the octet baryons in S=0,1S=0, -1 and -2 sectors, which is consistent with all of the available experimental binding energies of S=0,1S=0, -1 and -2 ss-shell (hyper-)nuclei, can predict a particle stable bound state of ΛΛ4^4_{\Lambda\Lambda}H. For ΛΛ5^5_{\Lambda\Lambda}H and ΛΛ5^5_{\Lambda\Lambda}He, ΛNΣN\Lambda N-\Sigma N and ΞNΛΣ\Xi N-\Lambda\Sigma potentials enhance the net ΛΛNΞ\Lambda\Lambda-N\Xi coupling, and a large Ξ\Xi probability is obtained even for a weaker ΛΛNΞ\Lambda\Lambda-N\Xi potential.Comment: 4 pages, 1 figur

    Self-Consistent Velocity Dependent Effective Interactions

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    The theory of self-consistent effective interactions in nuclei is extended for a system with a velocity dependent mean potential. By means of the field coupling method, we present a general prescription to derive effective interactions which are consistent with the mean potential. For a deformed system with the conventional pairing field, the velocity dependent effective interactions are derived as the multipole pairing interactions in doubly-stretched coordinates. They are applied to the microscopic analysis of the giant dipole resonances (GDR's) of 148,154Sm{}^{148,154}Sm, the first excited 2+2^+ states of Sn isotopes and the first excited 33^- states of Mo isotopes. It is clarified that the interactions play crucial roles in describing the splitting and structure of GDR peaks, in restoring the energy weighted sum rule, and in reducing the values of B(Eλ)B(E\lambda).Comment: 35 pages, RevTeX, 7 figures (available upon request), to appear in Phys.Rev.

    Bigradient Phase Referencing

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    We propose bigradient phase referencing (BPR), a new radio-observation technique, and report its performance using the Japanese very-long-baseline-interferometry network (JVN). In this method, a weak source is detected by phase-referencing using a primary calibrator, in order to play a role as a secondary calibrator for phase-referencing to a weak target. We will be given the opportunity to select a calibrator from lots of milli-Jansky sources, one of which may be located at the position closer to the target. With such a smaller separation, high-quality phase-referencing can be achieved. Furthermore, a subsequent more-sophisticated calibration can relocate array's focus to a hypothetical point much closer to the target; a higher quality of phase referencing is available. Our demonstrative observations with strong radio sources have proved the capabilities of BPR in terms of image dynamic ranges and astrometric reproducibility. The image dynamic range on a target has been improved with a factor of about six compared to that of normal phase-referencing; the resultant position difference of target's emission between two epochs was only 62+-50 micro-arcsecond, even with less than 2300-km baselines at 8.4 GHz and fast-switching of a target-calibrator pair of a 2.1-degree separation.Comment: 10 pages, 4 figures, accepted for publication in PAS

    The 2016 Kumamoto Earthquakes: Cascading Geological Hazards and Compounding Risks

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    A sequence of two strike-slip earthquakes occurred on April 14 and 16, 2016 in the intraplate region of Kyushu Island, Japan, apart from subduction zones, and caused significant damage and disruption to the Kumamoto region. The analyses of regional seismic catalog and available strong motion recordings reveal striking characteristics of the events, such as migrating seismicity, earthquake surface rupture, and major foreshock-mainshock earthquake sequences. To gain valuable lessons from the events, a UK Earthquake Engineering Field Investigation Team (EEFIT) was dispatched to Kumamoto, and earthquake damage surveys were conducted to relate observed earthquake characteristics to building and infrastructure damage caused by the earthquakes. The lessons learnt from the reconnaissance mission have important implications on current seismic design practice regarding the required seismic resistance of structures under multiple shocks and the seismic design of infrastructure subject to large ground deformation. The observations also highlight the consequences of cascading geological hazards on community resilience. To share the gathered damage data widely, geo-tagged photos are organized using Google Earth and the kmz file is made publicly available.The work is funded by the EPSRC grant (EP/I01778X/1) for the Earthquake Engineering Field Investigation Team (EEFIT). The financial supports for industrial members (GC, LH, LK, and RM) are provided by Arup, Mott MacDonald, and Willis

    Inhibition of Rho-associated coiled-coil containing protein kinase enhances the activation of epidermal growth factor receptor in pancreatic cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Rho-associated coiled-coil containing protein kinase (Rho-kinase/ROCK) is involved in various cellular functions including cell proliferation, and is generally considered to be oncogenic, while some studies show that ROCK functions as a negative regulator of cancer progression. As a result, the precise role of ROCK remains controversial. We have previously reported that Rho-kinase/ROCK negatively regulates epidermal growth factor (EGF)-induced cell proliferation in SW480 colon cancer cells. In the present study, we investigated the role of ROCK in EGF receptor (EGFR) signaling in the pancreatic cancer cell lines, Panc1, KP3 and AsPc1.</p> <p>Results</p> <p>In these cells, Y27632, a specific ROCK inhibitor, enhanced EGF-induced BrdU incorporation. The blockade of EGF stimulation utilizing anti-EGFR-neutralizing antibodies suppressed Panc1 cell proliferation. EGF induced RhoA activity, as well as the phosphorylation of cofilin and myosin light chain (MLC), both targets of ROCK signaling, and Y27632 suppressed both of these processes, indicating that the phosphorylation of cofilin and MLC by EGF occurs through ROCK in Panc1 cells. EGF-induced phosphorylation of EGFR at tyrosine residues was augmented when the cells were pretreated with Y27632 or were subjected to gene silencing using ROCK-siRNA. We also obtained similar results using transforming growth factor-α. In addition, EGF-induced phosphorylation of p44/p42 mitogen-activated protein kinase and Akt were also enhanced by Y27632 or ROCK-siRNA. Moreover, an immunofluorescence microscope study revealed that pretreatment with Y27632 delayed EGF-induced internalization of EGFR. Taken together, these data indicate that ROCK functions to switch off EGFR signaling by promoting the internalization of the EGFR.</p> <p>Conclusions</p> <p>While EGF first stimulates the activation of the EGFR and subsequently increases cancer cell proliferation, EGF concurrently induces the activation of ROCK, which then turns off the activated EGFR pathway via a negative feedback system.</p

    Overexpression of inhibitor of DNA-binding (ID)-1 protein related to angiogenesis in tumor advancement of ovarian cancers

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    <p>Abstract</p> <p>Background</p> <p>The inhibitor of DNA-binding (ID) has been involved in cell cycle regulation, apoptosis and angiogenesis. This prompted us to study ID functions in tumor advancement of ovarian cancers.</p> <p>Methods</p> <p>Sixty patients underwent surgery for ovarian cancers. In ovarian cancers, the levels of ID-1, ID-2 and ID-3 mRNAs were determined by real-time reverse transcription-polymerase chain reaction. The histoscore with the localization of ID-1 was determined by immunohistochemistry. Patient prognosis was analyzed with a 36-month survival rate. Microvessel counts were determined by immunohistochemistry for CD34 and factor VIII-related antigen.</p> <p>Results</p> <p>ID-1 histoscores and mRNA levels both significantly (p < 0.001) increased in ovarian cancers according to clinical stage, regardless of histopathological type. Furthermore, 30 patients with high ID-1 expression had a lower survival rate (53%) compared to patients with low ID-1 expression (80%). ID-1 histoscores and mRNA levels significantly (p < 0.0001) correlated with microvessel counts in ovarian cancers.</p> <p>Conclusion</p> <p>ID-1 increased in ovarian cancer cells during tumor progression. Moreover, ID-1 expression levels correlated with microvessel counts. Therefore, ID-1 might work on tumor advancement via angiogenesis and is considered to be a candidate for a prognostic indicator in ovarian cancers.</p

    4-(4-Octyloxybenzo­yloxy)benzoic acid

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    The title compound, C22H26O5, is an important inter­mediate for the synthesis of side-chain ligands for polymeric liquid crystals. The octyl group is coplanar with the central C6O moiety, where the maximum deviation of a C atom in the octyl group from the C6O plane is 0.161 (5) Å. The crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonds

    (E)-4-(4-Fluoro­styr­yl)benzoic acid

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    The title compound, C15H11FO2, is an important inter­mediate in the synthesis of side-chain ligands for polymeric liquid crystals. The vinyl group is almost coplanar with both the aromatic rings. The crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonding

    Purification of functional baculovirus particles from silkworm larval hemolymph and their use as nanoparticles for the detection of human prorenin receptor (PRR) binding

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    <p>Abstract</p> <p>Background</p> <p>Baculovirus, which has a width of 40 nm and a length of 250-300 nm, can display functional peptides, receptors and antigens on its surface by their fusion with a baculovirus envelop protein, GP64. In addition, some transmembrane proteins can be displayed without GP64 fusion, using the native transmembrane domains of the baculovirus. We used this functionality to display human prorenin receptor fused with GFP<sub>uv </sub>(GFP<sub>uv</sub>-hPRR) on the surface of silkworm <it>Bombyx mori </it>nucleopolyhedrovirus (BmNPV) and then tested whether these baculovirus particles could be used to detect protein-protein interactions.</p> <p>Results</p> <p>BmNPV displaying GFP<sub>uv</sub>-hPRR (BmNPV-GFP<sub>uv</sub>-hPRR) was purified from hemolymph by using Sephacryl S-1000 column chromatography in the presence of 0.01% Triton X-100. Its recovery was 86% and the final baculovirus particles number was 4.98 × 10<sup>8 </sup>pfu. Based on the results of enzyme-linked immunosorbent assay (ELISA), 3.1% of the total proteins in BmNPV-GFP<sub>uv</sub>-hPRR were GFP<sub>uv</sub>-hPRR. This value was similar to that calculated from the result of western blot by a densitometry (2.7%). To determine whether BmNPV-GFP<sub>uv</sub>-hPRR particles were bound to human prorenin, ELISA results were compared with those from ELISAs using protease negative BmNPV displaying β1,3-<it>N</it>-acetylglucosaminyltransferase 2 fused with the gene encoding GFP<sub>uv </sub>(GGT2) (BmNPV-<it>CP</it><sup>-</sup>-GGT2) particles, which do not display hPRR on their surfaces.</p> <p>Conclusion</p> <p>The display of on the surface of the BmNPV particles will be useful for the detection of protein-protein interactions and the screening of inhibitors and drugs in their roles as nanobioparticles.</p

    5-(4-Fluoro­phen­yl)-5-methyl­imidazolidine-2,4-dione

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    In the title compound, C10H9FN2O2, the dihedral angle between the hydantoin unit and the benzene ring is 65.55 (5)°. The atoms in the hydantoin ring are coplanar, with a mean deviation of 0.015 Å and a maximum deviation of 0.075 (2) Å for one carbonyl O atom. N—H⋯O hydrogen bonds link the mol­ecules into one-dimensional chains, with one carbonyl group acting as a bifurcated acceptor and the other accepting no hydrogen bonds
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