536 research outputs found

    Cluster structures in 11^{11}B

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    Structures of excited states in 11^{11}B are investigated with a method of β\beta-γ\gamma constraint antisymmetrized molecular dynamics in combination with the generator coordinate method. Various excited states with developed cluster core structures are suggested in positive- and negative-parity states. For negative-parity states, we suggest a band with a 2α+t2\alpha+t cluster structure. This band starts from the 3/233/2^{-}_{3} state and can correspond to the experimental band observed recently. In positive-parity states, two α\alpha core cluster structures with surrounding nucleons are found. A Kπ=1/2+K^\pi=1/2^+ band is suggested to be constructed from a remarkably developed cluster structure with a large prolate deformation. We discuss features of the cluster structure in association with molecular orbital structures of 10^{10}Be.Comment: 13 pages, 9 figures. arXiv admin note: text overlap with arXiv:1004.495

    Cluster structures of excited states in 14^{14}C

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    Structures of excited states in 14^{14}C are investigated with a method of β\beta-γ\gamma constraint antisymmetrized molecular dynamics in combination with the generator coordinate method. Various excited states with the developed 3α3\alpha-cluster core structures are suggested in positive- and negative-parity states. In the positive-parity states, triaxial deformed and linear-chain structures are found to construct excited bands. Interestingly, 10^{10}Be+α\alpha correlation is found in the cluster states above the 10^{10}Be+α\alpha threshold energy.Comment: 17 pages, 9 figure

    Negative parity states of 11^{11}B and 11^{11}C and the similarity with $^{12}C

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    The negative parity states of 11^{11}B and 11^{11}C were studied based on the calculations of antisymmetrized molecular dynamics(AMD). The calculations well reproduced the experimental strengths of Gamov-Teller(GT), M1M1 and monopole transitions. We, especially, focused on the 3/233/2^-_3 and 5/225/2^-_2 states, for which GT transition strengths were recently measured. The weak M1M1 and GT transitions for the 3/233/2^-_3 in 11^{11}B and 11^{11}C are described by a well-developed cluster structure of 2α2\alpha+tt and 2α2\alpha+3^3He, respectively, while the strong transitions for the 5/225/2^-_2 is characterized by an intrinsic spin excitation with no cluster structure. It was found that the 3/233/2^-_3 state is a dilute cluster state, and its features are similar to those of the 12^{12}C(02+)(0^+_2) which is considered to be a gas state of three α\alpha clusters.Comment: 10 pages, 4 figures, submitterd to Physical Review

    Clustering and Triaxial Deformations of 40^{40}Ca

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    We have studied the positive-parity states of 40^{40}Ca using antisymmetrized molecular dynamics (AMD) and the generator coordinate method (GCM). Imposing two different kinds of constraints on the variational calculation, we have found various kinds of 40Ca^{40}{\rm Ca} structures such as a deformed-shell structure, as well as α\alpha-36^{36}Ar and 12^{12}C-28^{28}Si cluster structures. After the GCM calculation, we obtained a normal-deformed band and a superdeformed band together with their side bands associated with triaxial deformation. The calculated B(E2)B(E2) values agreed well with empirical data. It was also found that the normal-deformed and superdeformed bands have a non-negligible α\alpha-36^{36}Ar cluster component and 12^{12}C-28^{28}Si cluster component, respectively. This leads to the presence of an α\alpha-36^{36}Ar higher-nodal band occurring above the normal-deformed band.Comment: 11pages, 9 figure

    Pengaruh Aromaterapi Rosemary Terhadap Atensi

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    Latar belakang : Aromaterapi merupakan suatu metode pengobatan alternatif berupa media bau-bauan yang berasal dari bahan tanaman mudah menguap. Selain berperan sebagai media relaksasi, aromaterapi juga memiliki pengaruh yang positif terhadap beberapa fungsi kognitif. Salah satu parameter untuk mengevaluasi kemampuan kognisi adalah atensi. Atensi merupakan suatu USAha pemusatan pikiran terhadap suatu objek untuk menghadapi objek tersebut dimana melibatkan berbagai macam aspek psikologis dan neurologis. Atensi terdiri dari tiga aspek, yaitu alerting, orienting, dan executive attention.Tujuan : Mengetahui pemberian aromaterapi rosemary terhadap peningkatan atensi.Metode : Penelitian ini menggunakan metode eksperimental murni. Sampel penelitian adalah mahasiswa Fakultas Kedokteran Undip (n=20) yang diukur atensinya menggunakan software Attention Network Test sebelum dan sesudah diberikan paparan aromaterapi Rosemary selama ± 30 menit. Atensi antara sebelum dan sesudah bermain video game dianalisis menggunakan uji T berpasangan, sedangkan Perubahan atensi antar kelompok dianalisis dengan menggunakan uji T tidak berpasangan.Hasil : Ditemukan rerata peningkatan atensi pada fungsi alerting subjek penelitian yang diberikan paparan aromaterapi rosemary selama ± 30 menit dari 47,77 ± 21,77 ms menjadi 29,00 ± 6,14 ms dengan p = 0,001 (p < 0,05).Kesimpulan : Pemberian paparan aromaterapi rosemary dapat meningkatkan atensi pada fungsi alerting

    Nano-Architecture of Osteocyte Lacunae

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    Cluster formations in deformed states for 28^{28}Si and 32^{32}S

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    We study cluster formation in strongly deformed states for 28^{28}Si and 32^{32}S using a macroscopic-microscopic model. The study is based on calculated total-energy surfaces, which are the sums of deformation-dependent macroscopic-microscopic potential-energy surfaces and rotational-energy contributions. We analyze the angular-momentum-dependent total-energy surfaces and identify the normal- and super-deformed states in 28^{28}Si and 32^{32}S, respectively. We show that at sufficiently high angular momenta strongly deformed minima appear. The corresponding microscopic density distributions show cluster structure that closely resemble the 16^{16}O+12^{12}C and 16^{16}O+16^{16}O configurations. At still higher deformations, beyond the minima, valleys develop in the calculated surfaces. These valleys lead to mass divisions that correspond to the target-projectile configurations for which molecular resonance states have been observed. We discuss the relation between the one-body deformed minima and the two-body molecular-resonance states.Comment: 6 pages, 7 figure

    Reassessing the Role of APOBEC3G in Human Immunodeficiency Virus Type 1 Infection of Quiescent CD4+ T-Cells

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    HIV-1 is restricted for infection of primary quiescent T-cells. After viral entry, reverse transcription is initiated but is not completed. Various hypotheses have been proposed for this cellular restriction including insufficient nucleotide pools and cellular factors, but none have been confirmed as the primary mechanism for restriction. A recent study by Chiu et al. implicates APOBEC3G, an anti-retroviral cytidine deaminase, as the cellular restriction factor. Here, we attempted to confirm these findings using the same strategy as reported by Chiu et al. of siRNA targeting knock-down of APOBEC3G expression. In contrast to the published study, our results do not support a role for APOBEC3G in restriction of HIV-1 in quiescent CD4+ T-cells. In our study, we tested the same siRNA as reported by Chiu et al. as well as two additional siRNAs targeting APOBEC3G, one of which showed 2-fold greater knock-down of APOBEC3G mRNA. However, none of the three siRNAs tested had a discernable effect on enhancing infection by HIV-1 in quiescent CD4+ T-cells. Therefore, we conclude that the primary mechanism of HIV-1 restriction in quiescent CD4+ T-cells remains to be elucidated

    A MULTIMEDIA MODEL FOR THE EVALUATION OF ENVIRONMENTAL BEHAVIOR OF DIOXINS

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    Joint Research on Environmental Science and Technology for the Eart

    The high correlation between counts and area fractions of lipofuscin granules, a biomarker of oxidative stress in muscular dystrophies

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    Images of cryostat unstained sections of two skeletal muscles, diaphragm and extensor digitorum longus (EDL), from wild-type normal and dystrophic mdx mice were captured with a fluorescence microscope, binarised and analysed by an automated procedure using ImageJ free software. The numbers, Feret diameters and areas of autofluorescent lipofuscin (LF)-like granules in the sections were determined from the binary images. The mean numbers of counted LF granules per mm(3) muscle tissue correlated highly (r ≥ 0.9) with the area fractions of the granules in sections of both normal and mdx muscles. The similar distribution patterns of granule sizes in sections of diaphragm and EDL muscles are consistent with the high correlations
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