1,004 research outputs found

    New Integrable Multi-Component NLS Type Equations on Symmetric Spaces: Z_4 and Z_6 Reductions

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    The reductions of the multi-component nonlinear Schrodinger (MNLS) type models related to C.I and D.III type symmetric spaces are studied. We pay special attention to the MNLS related to the sp(4), so(10) and so(12) Lie algebras. The MNLS related to sp(4) is a three-component MNLS which finds applications to Bose-Einstein condensates. The MNLS related to so(12) and so(10) Lie algebras after convenient Z_6 or Z_4 reductions reduce to three and four-component MNLS showing new types of chi ^(3)-interactions that are integrable. We briefly explain how these new types of MNLS can be integrated by the inverse scattering method. The spectral properties of the Lax operators L and the corresponding recursion operator Lambda are outlined. Applications to spinor model of Bose-Einstein condensates are discussed.Comment: Reported to the Seventh International conference "Geometry, Integrability and Quantization", June 2--10, 2005, Varna, Bulgari

    Fordy-Kulish models and spinor Bose-Einstein condensates

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    A three-component nonlinear Schrodinger-type model which describes spinor Bose-Einstein condensate (BEC) is considered. This model is integrable by the inverse scattering method and using Zakharov-Shabat dressing method we obtain three types of soliton solutions. The multi-component nonlinear Schrodinger type models related to symmetric spaces C.I Sp(4)/U(2) is studied.Comment: 8 pages, LaTeX, jnmp styl

    Directed current due to broken time-space symmetry

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    We consider the classical dynamics of a particle in a one-dimensional space-periodic potential U(X) = U(X+2\pi) under the influence of a time-periodic space-homogeneous external field E(t)=E(t+T). If E(t) is neither symmetric function of t nor antisymmetric under time shifts E(t±T/2)E(t)E(t \pm T/2) \neq -E(t), an ensemble of trajectories with zero current at t=0 yields a nonzero finite current as tt\to \infty. We explain this effect using symmetry considerations and perturbation theory. Finally we add dissipation (friction) and demonstrate that the resulting set of attractors keeps the broken symmetry property in the basins of attraction and leads to directed currents as well.Comment: 2 figure

    Применение обогащенной тромбоцитами плазмы с целью профилактики поздних осложнений и болевого синдрома после герниопластики

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    Цель. За счет применения обогащенной тромбоцитами плазмы (ОTП) снизить степень выраженности поздних осложнений у больных, оперированных по поводу инцизионных вентральных грыж. Материалы и методы. В клиническое исследование, проведенное в условиях хирургического отделения Центра реконструктивной и восстановительной медицины (Университетская клиника) Одесского национального медицинского университета с 2013 по 2019 г., включены 84 больных, оперированных по поводу послеоперационных вентральных грыж. Средний возраст больных составил (60,1 ± 7,6) года, размер грыжевых дефектов - 8,2 см, средний индекс массы тела – 31,8 кг/м2. Больным по показаниям выполнен стандартный объем оперативного вмешательства: грыжесечение, герниопластика передней брюшной стенки облегченным (80 г/м2) полипропиленовым имплантатом. Пациентам основной группы после выполнения пластики зону имплантации протеза инфильтрировали активированной аутологичной ОТП, которая была заготовлена путем двойного центрифугирования, в объеме 14 – 38 мл. Пациентам контрольной группы инфильтрацию ОТП не выполняли. Качество жизни пациентов оценивали с помощью стандартизированного опросника SF-36 до операции, а также в послеоперационном периоде. С целью дифференцирования нейропатической боли применяли опросники DN4 и ID Pain. Результаты. У пациентов обеих групп в послеоперационном периоде отмечали повышение показателей качества жизни. Статистическая достоверность различий показателей была выше у пациентов с надапоневротическим расположением протеза. Показатели физического здоровья и ассоциированные с ними показатели социальной активности, общего состояния здоровья демонстрировали значимо более высокий уровень качества жизни у пациентов основной группы. Показатель общего состояния здоровья у больных после надапоневротической герниопластики с применением ОТП был достоверно выше, чем в контрольной группе – соответственно 69,3 ± 3,8 и 59,7 ± 4,1 (p < 0,05). Выводы. Техника инфильтрации мягких тканей, контактирующих с полипропиленовым протезом, безопасна, достоверно не увеличивает риск возникновения локальных или системных осложнений. Предложенная методика за счет модификации репаративных процессов в зоне герниопластики способствует интеграции протеза, снижает риск развития и степень выраженности биомеханических нарушений, хронического болевого синдрома, что положительно сказывается на качестве жизни пациентов. Эффективность техники статистически достоверно выше у пациентов после надапоневротической герниопластики

    Selected Extracts of Chinese Herbal Medicines: Their Effect on NF-κB, PPARα and PPARγ and the Respective Bioactive Compounds

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    Chinese herbal medicinal (CHM) extracts from fourteen plants were investigated in cell-based in vitro assays for their effect on nuclear factor κB (NF-κB), a key regulator of inflammation, as well as on peroxisome proliferator-activated receptors (PPARs) being key regulators of genes involved in lipid and glucose metabolism. 43% of the investigated CHMs showed NF-κB inhibitory and 50% PPARα and PPARγ activating effects. Apolar extracts from cortex and flos of Albizia julibrissin Durazz. and processed rhizomes of Arisaema sp. and Pinellia ternata (Thunb.) Breit. that effectively inhibited TNF-α-induced NF-κB activation and dose-dependently activated PPARα and PPARγ were further investigated. Bioassay-guided fractionation and analysis by GC-MS led to the identification of fatty acids as PPAR agonists, including linoleic and palmitic acid

    Optically induced coherent intra-band dynamics in disordered semiconductors

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    On the basis of a tight-binding model for a strongly disordered semiconductor with correlated conduction- and valence band disorder a new coherent dynamical intra-band effect is analyzed. For systems that are excited by two, specially designed ultrashort light-pulse sequences delayed by tau relatively to each other echo-like phenomena are predicted to occur. In addition to the inter-band photon echo which shows up at exactly t=2*tau relative to the first pulse, the system responds with two spontaneous intra-band current pulses preceding and following the appearance of the photon echo. The temporal splitting depends on the electron-hole mass ratio. Calculating the population relaxation rate due to Coulomb scattering, it is concluded that the predicted new dynamical effect should be experimentally observable in an interacting and strongly disordered system, such as the Quantum-Coulomb-Glass.Comment: to be published in Physical Review B15 February 200

    On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes

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    A series of water-bridged dinickel complexes of the general formula [Ni&lt;sub&gt;2&lt;/sub&gt;(μ&lt;sub&gt;2&lt;/sub&gt;-OH&lt;sub&gt;2&lt;/sub&gt;)(μ2- O&lt;sub&gt;2&lt;/sub&gt;C&lt;sup&gt;t&lt;/sup&gt;Bu)&lt;sub&gt;2&lt;/sub&gt;(O&lt;sub&gt;2&lt;/sub&gt;C&lt;sup&gt;t&lt;/sup&gt;Bu)2(L)(L0)] (L = HO&lt;sub&gt;2&lt;/sub&gt;C&lt;sup&gt;t&lt;/sup&gt;Bu, L0 = HO&lt;sub&gt;2&lt;/sub&gt;C&lt;sup&gt;t&lt;/sup&gt;Bu (1), pyridine (2), 3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized and structurally characterized by X-ray crystallography. The magnetic properties have been probed by magnetometry and EPR spectroscopy, and detailed measurements show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange interaction can be related to the angle between the nickel centers and the bridging water molecule, while the magnitude of D can be related to the coordination sphere at the nickel sites

    The Effect of Natural Antioxidants on Quality and Shelf Life of Beef and Beef Products

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    Oksidacijski procesi su glavni razlog kvarenja mesa i kraće trajnosti mesnih proizvoda i uzrokuju nepoželjne promjene hranjive vrijednosti te senzorskih i fizikalno-kemijskih svojstava mesa. Dosad su se za sprječavanje oksidacijskih procesa najčešće koristili sintetski antioksidansi poput butil-hidroksianisola (BHA), koji mogu predstavljati rizik za zdravlje ljudi te povećati toksičnost proizvoda. Međutim, prirodni antioksidansi mogu riješiti taj problem jer su biljke i biljni materijal bogati bioaktivnim spojevima (prirodnim antioksidansima) koji mogu pozitivno utjecati na zdravlje. Nadalje, zanimanje potrošača za prirodne proizvode i dalje je u porastu, pri čemu se očekuje da se sintetski antioksidansi i konzervansi zamijene prirodnim. Svrha je ovog preglednog rada prikazati učinak prirodnih antioksidanasa, i to povrća i voća kao što su masline, nar i grožđe, ali i ljekovitog bilja i začina poput ružmarina, origana, kadulje, kima i crnog kima ili kurkume, bogatih bioaktivnim spojevima, na kakvoću i trajnost goveđeg mesa i njegovih prerađevina.Oxidation processes are the major cause of deterioration of meat quality and shelf life of meat products, leading to negative changes in nutritive value and in sensory and physicochemical properties of meat. Until now, the synthetic antioxidants like butylated hydroxyl anisole have been commonly used to prevent oxidation, which however may cause potential human health risks and increase toxicity of the product. However, natural antioxidants can be the alternative solution for this problem since plants and plant materials are rich in bioactive compounds (as natural antioxidants) with potential health beneficial effects. Moreover, the interest of consumers in using natural products is still increasing. There is an expectation of replacing synthetic antioxidants and preservatives by natural ones. Therefore, the aim of the present review is to provide information on the effect of natural antioxidants from vegetables and fruits like olives, pomegranate or grapes, and herbs and spices like rosemary, oregano, sage, black cumin or turmeric, rich in bioactive compounds on quality and shelf life of beef and beef products

    Studies of the Response of the Prototype CMS Hadron Calorimeter, Including Magnetic Field Effects, to Pion, Electron, and Muon Beams

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    We report on the response of a prototype CMS hadron calorimeter module to charged particle beams of pions, muons, and electrons with momenta up to 375 GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. The effects of a magnetic field of up to 3 Tesla on the response of the calorimeter to muons, electrons, and pions are presented, and the effects of an upstream lead tungstate crystal electromagnetic calorimeter on the linearity and energy resolution of the combined calorimetric system to hadrons are evaluated. The results are compared with Monte Carlo simulations and are used to optimize the choice of total absorber depth, sampling frequency, and longitudinal readout segmentation.Comment: 89 pages, 41 figures, to be published in NIM, corresponding author: P de Barbaro, [email protected]
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