Examination of the astrophysical S-factors of the radiative proton capture on 2H, 6Li, 7Li, 12C and 13C

Astrophysical S-factors of radiative capture reactions on light nuclei have been calculated in a two-cluster potential model, taking into account the separation of orbital states by the use of Young schemes. The local two-body potentials describing the interaction of the clusters were determined by fitting scattering data and properties of bound states. The many-body character of the problem is approximatively accounted for by Pauli forbidden states. An important feature of the approach is the consideration of the dependence of the interaction potential between the clusters on the orbital Young schemes, which determine the permutation symmetry of the nucleon system. Proton capture on 2H, 6Li, 7Li, 12C, and 13C was analyzed in this approach. Experimental data at low energies were described reasonably well when the phase shifts for cluster-cluster scattering, extracted from precise data, were used. This shows that decreasing the experimental error on differential elastic scattering cross sections of light nuclei at astrophysical energies is very important also to allow a more accurate phase shift analysis. A future increase in precision will allow more definite conclusions regarding the reaction mechanisms and astrophysical conditions of thermonuclear reactions.Comment: 40p., 9 fig., 83 ref. arXiv admin note: substantial text overlap with arXiv:1005.1794, arXiv:1112.1760, arXiv:1005.198

Formation of 24Mg* in the Splitting of 28Si Nuclei by 1-GeV Protons

The 28Si(p, p' gamma)24Mg reaction has been studied at the ITEP accelerator by the hadron-gamma coincidence method for a proton energy of 1 GeV. Two reaction products are detected: a 1368.6-keV gamma-ray photon accompanying the transition of the 24Mg* nucleus from the first excited state to the ground state and a proton p' whose momentum is measured in a magnetic spectrometer. The measured distribution in the energy lost by the proton in interaction is attributed to five processes: the direct knockout of a nuclear alpha cluster, the knockout of four nucleons with a total charge number of 2, the formation of the DeltaSi isobaric nucleus, the formation of the Delta isobar in the interaction of the incident proton with a nuclear nucleon, and the production of a pi meson, which is at rest in the nuclear reference frame. The last process likely corresponds to the reaction of the formation of a deeply bound pion state in the 28P nucleus. Such states were previously observed only on heavy nuclei. The cross sections for the listed processes have been estimated.Comment: 14 pages, 3 figures submitted to JETP Letter

Microscopics of meson degrees of freedom in nucleons and mesons in nuclei - what can be seen in the process of quasielastic knockout of mesons by high-energy electrons

Developed earlier concept of quasielastic knock out of pions from nucleons by high-energy electrons is propounded as a tool for checking microscopical model ($^3P_0$ - fluctuation) for decay of N to different channels $\pi+B$ and Preparata model of nucleus structure.Comment: 6 pages, 5 figures, Talk given at 16 Baldin Symposium in June 200

In memoriam two distinguished participants of the Bregenz Symmetries in Science Symposia: Marcos Moshinsky and Yurii Fedorovich Smirnov

Some particular facets of the numerous works by Marcos Moshinsky and Yurii Fedorovich Smirnov are presented in these notes. The accent is put on some of the common interests of Yurii and Marcos in physics, theoretical chemistry, and mathematical physics. These notes also contain some more personal memories of Yurii Smirnov.Comment: Submitted for publication in Journal of Physics: Conference Serie

Astrophysical S-factor for the radiative capture reaction 13C(p,g)14N

The phase shift analysis, done on the basis of the known measurements of the differential cross-sections of the p13C elastic scattering at the energy range 250-750 keV, shows that it is enough to take into account only 3S1 wave in the considered energy region. The potential for the triplet 3S1 state in p13C system at the resonance energy 0.55 MeV corresponding to quantum numbers JpT = 1-1 as well as the potential for the 3P1 bound state of 14N were constructed on the basis of the obtained scattering phase shifts. The possibility to describe the experimental data of the astrophysical S-factor of the p13C radiative capture at the energies 0.03-0.8 MeV was considered within the potential cluster model with the forbidden states. It was shown that we properly succeed in explanation of the energy behavior of the astrophysical S-factor for the p13C radiative capture at the resonance energy range 0.55 MeV (laboratory system).Comment: 8 p., 2 fi

Astrophysical S-factor of 4He12C radiative capture at low energies

The possibility to describe the astrophysical S-factor of the 4He12C radiative capture is considered in the potential cluster model at the energy range 0.1-4.0 MeV. It is shown that the approach used, which takes into account E2 transitions only, gives a good description of the new experimental data for adjusted parameters of potentials and leads to the value S(300) = 16.0$\cdotp$keV b.Comment: 8 Pag

Экспериментальные подходы к созданию тканеспецифического матрикса для биоискусственной печени

Shortage of donor organs for liver transplantation in the treatment of end-stage liver disease dictates the need to develop alternative methods that include technologies on tissue engineering and regenerative medicine. Objective: to study the ability of a tissue-specific matrix from decellularized human liver fragments (DHLF) to maintain adhesion and proliferation of human adipose tissue-derived mesenchymal stem cells (hAT-MSCs) and HepG2 under static conditions and in a flow-through bioreactor. Materials and methods. Treatment with surfactants (SAS) – sodium dodecyl sulfate, Triton X-100 – followed by exposure to DNase was used for decellularization of human liver fragments (no more than 8 mm3). Biochemical screening included the determination of DNA quantity in the test samples. Efficiency of surfactant washing was assessed by the cytotoxicity of the matrix in the NIH 3T3 fibroblast culture. Viability and metabolic activity of cells were assessed via vital staining with a complex of fluorescent dyes LIVE/DEAD ® and PrestoBlue™ (Invitrogen, USA). Morphological examination of the liver cell-engineered constructs was carried out through histological staining and scanning electron microscopy with lanthanide contrast. Results. It was shown that the liver decellularization method used allows to obtain a biocompatible matrix with a residual DNA quantity <1%, which is capable of maintaining adhesion and proliferation of hAT-MSCs and HepG2. On day 7 of cultivation in the bioreactor, there was formation of a single conglomerate of the DHLF matrix with numerous groups of viable cells with a high nuclear-cytoplasmic ratio. The urea content in the culture medium is 1.5 ± 0.1 mmol/L, exceeding that of samples obtained under static conditions. This indicates the metabolic activity of HepG2 in the composition of the obtained culture systems. It was shown that constant flow of the culture medium in the perfusion bioreactor increased the proliferative activity of HepG2 and allowed to provide a more uniform colonization by matrix cells in comparison with static cultivation conditions. Conclusion. The conditions for uniform colonization of DHLFs in a flow-through bioreactor with cell cultures were established. The ability of the matrix to maintain adhesion and proliferation of hADSCs and HepG2 for 11 days indicates that it could be used in liver tissue engineering.Дефицит донорских органов для трансплантации печени при лечении терминальных стадий печеночной недостаточности диктует необходимость разработки альтернативных методов, к которым относятся технологии тканевой инженерии и регенеративной медицины. Целью работы было исследование способности тканеспецифического матрикса из децеллюляризованных фрагментов печени человека (ДФПч) поддерживать адгезию и пролиферацию мезенхимальных стромальных клеток жировой ткани человека (МСК ЖТч) и HepG2 в статических условиях и в проточном биореакторе. Материалы и методы. Для децеллюляризации фрагментов (не более 8 мм3) печени человека использовали обработку поверхностноактивными веществами (ПАВ) – додецилсульфатом натрия, Тритоном Х-100 с последующей экспозицией в ДНКазе. Биохимические исследования включали определение количества ДНК в исследуемых образцах. Эффективность отмывки от ПАВ оценивали по цитотоксичности матрикса на культуре фибробластов NIH 3T3. Оценку жизнеспособности и метаболической активности клеток проводили методом прижизненного окрашивания комплексом флюоресцентных красителей LIVE/DEAD ® и PrestoBlue™ (Invitrogen, США). Морфологическое исследование клеточно-инженерных конструкций печени проводили с использованием методов гистологического окрашивания и сканирующей электронной микроскопии с лантаноидным контрастированием. Результаты. Показано, что использованная методика децеллюляризации печени позволяет получать биосовместимый матрикс с остаточным количеством ДНК менее 1%, способный поддерживать адгезию и пролиферацию МСК ЖТч и HepG2. В биореакторе на 7-е сутки культивирования наблюдали образование единого конгломерата матрикса ДФПч с многочисленными группами жизнеспособных клеток с высоким ядерно-цитоплазматическим отношением. Содержание мочевины в культуральной среде превышает значение для образцов, полученных в статических условиях, и составляет 1,5 ± 0,1 ммоль/л, что свидетельствует о метаболической активности HepG2 в составе полученных культуральных систем. Показано, что постоянный поток культуральной среды перфузионного биореактора способствовал росту пролиферативой активности HepG2 и позволил обеспечить более равномерную колонизацию клетками матрикса по сравнению со статическими условиями культивирования. Заключение. Найдены условия равномерного заселения ДФПч в проточном биореакторе клеточными культурами. Способность матрикса поддерживать адгезию и пролиферацию МСК ЖТч и HepG2 в течение 11 суток свидетельствует о возможности его использования в тканевой инженерии печени

Daily omega-3 fatty acid intake and depression in Japanese patients with newly diagnosed lung cancer

patients with newly diagnosed lung cance