369 research outputs found

    Correlations in Nuclear Matter

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    We analyze the nuclear matter correlation properties in terms of the pair correlation function. To this aim we systematically compare the results for the variational method in the Lowest Order Constrained Variational (LOCV) approximation and for the Bruekner-Hartree-Fock (BHF) scheme. A formal link between the Jastrow correlation factor of LOCV and the Defect Function (DF) of BHF is established and it is shown under which conditions and approximations the two approaches are equivalent. From the numerical comparison it turns out that the two correlation functions are quite close, which indicates in particular that the DF is approximately local and momentum independent. The Equations of State (EOS) of Nuclear Matter in the two approaches are also compared. It is found that once the three-body forces (TBF) are introduced the two EOS are fairly close, while the agreement between the correlation functions holds with or without TBF.Comment: 11 figure

    Effect of hydroalcoholic extract of Matricaria chamomilla on passive avoidance memory and pain induced by global cerebral ischemia in Wistar rat

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    زمینه و هدف : ایسکمی مغزی و خونرسانی مجدد علت اصلی ناتوانی جدی و طولانی مدت در جهان است. هدف از مطالعه حاضر بررسی اثر عصاره هیدروالکلی بابونه بر اختلالات حافظه و درد ناشی از ایسکمی بود. روش بررسی: گل‌های خشک بابونه (Matricaria chamomilla) از عطاری تهیه شده و توسط الکل 70 درصد عصاره گیری شد. حیوانات به صورت تصادفی به 6 گروه 7 تایی تقسیم شدند. گروه کنترل فقط نرمال سالین دریافت کردند، گروه ایسکمی تحت ایسکمی قرار گرفته و نرمال سالین دریافت کردند، گروه شاهد(sham): تحت جراحی قرار گرفتند بدون اینکه شریان‌های کاروتید آن‌ها بسته شود. گروه‌های درمانی با عصاره تحت ایسکمی قرار گرفته و عصاره بابونه را به صورت داخل صفاقی در دوز 50، 100 و 200 میلی‌گرم بر کیلوگرم وزن بدن دریافت کردند. تست رفتاری توسط شاتل باکس و تست ضد درد توسط تست تیل فیلیک انجام شد. یافته ها : عصاره بابونه در غلظت‌های 50، 100 و 200 میلی‌گرم بر کیلوگرم حافظه احترازی غیرفعال موش‌های صحرایی تحت ایسکمی را به طور معنی‌دار افزایش داد. علاوه بر این عصاره بابونه زمان تأخیر ظهور رفلکس دردناک دم را در تست تیل فلیک به طور معنی‌داری افزایش داد و غلظت 50 میلی‌گرم بر کیلوگرم عصاره اثر بیشتری نسبت به غلظت‌های بالاتر آن نشان داد. بحث و نتیجه گیری: نتایج مطالعه حاضر حاکی از اثرات حفاظتی عصاره بابونه در برابر اختلال حافظه احترازی و درد ایجاد شده در اثر ایسکمی بود که احتمالا به دلیل اثرات آنتی‌اکسیدانی و ضدالتهابی عصاره گیاه می‌باش

    Investigation of relationship between musculoskeletal disorders and working conditions among workers at a pharmaceutical industry in Iran (2011-2012)

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    Musculoskeletal disorders may be observed in all industries and professions and most of these disorders are related to the back, upper and lower extremities of the body organs. In Pharmaceutical industry, almost lack of standard ergonomic conditions and sometimes can cause outbreaks of diseases and musculoskeletal disorders in various parts of the body. The aim of this study was to determine the relationship between musculoskeletal disorders and working on the packaging section of the pharmaceutical industry. The Nordic questionnaire and Rula method were used for collection of data and 392 workers were selected as the subjects of study. Based on the results of this study, (28.5%) of workers working in Packaging Unit complained of severe pain and discomfort in their neck, (23.7%) in their shoulder, (27.9%) in their hand and wrist and (33.2%) complained of severe pain in their back. The results indicate that workers in this industry could show musculoskeletal disorders based on age, education, gender and working conductions

    Halotolerant Ability and α-Amylase Activity of Some Saltwater Fungal Isolates

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    Four halotolerant fungal isolates originating from the saltwater Lake Urmia in Iran were selected during a screening program for salt resistance and α-amylase activity. The isolates were identified based on sequencing the ITS region and a part of the β-tubulin gene, as Penicillium chrysogenum (isolate U1; CBS 132820), Fusarium incarnatum (isolate U2; CBS 132821), and Penicillium polonicum (isolate U3; CBS 132822, and isolate U4; CBS 132823). The growth of these isolates was determined by measuring the colony diameter and mycelia dry weight in Sabouraud dextrose agar and yeast nitrogen base medium supplemented with NaCl, KCl, and LiCl. Isolate U4 showed a growth up in 15% NaCl and U1 was the only isolate that could grow in 20% KCl. None of the strains grew in a media containing LiCl. The salt supplemented medium did not increase the size of colony diameter in all isolates (p > 0.05). The ability of the selected isolates for amylase production was quantitatively tested and showed that P. polonicum isolate U4 was the most potent producer of amylase with a yield of 260.9 U/L after 60 h, whereas P. polonicum isolate U3 was the lowest one with a production level of 97.9 U/L after 48 h. P. polonicum isolate U4 could be a suitable candidate for production of amylase on an industrial scale after optimization. © 2013 by School of Pharmacy

    First-order phase transition from hypernuclear matter to deconfined quark matter obeying new constraints from compact star observations

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    We reconsider the problem of the hyperon puzzle and its suggested solution by quark deconfinement within the two-phase approach to hybrid compact stars with recently obtained hadronic and quark matter equations of state. For the hadronic phase we employ the hypernuclear equation of state from the lowest order constrained variational method and the quark matter phase is described by a sufficiently stiff equation of state based on a color superconducting nonlocal Nambu-Jona-Lasinio model with constant (model nlNJLA) and with density-dependent (model nlNJLB) parameters. We study the model dependence of the phase transition obtained by a Maxwell construction. Our study confirms that also with the present set of equations of state quark deconfinement presents a viable solution of the hyperon puzzle even for the new constraint on the lower limit of the maximum mass from PSR J0740+6620. In this work we provide with model nlNJLB for the first time a hybrid star EoS with an intermediate hypernuclear matter phase between the nuclear and color superconducting quark matter phases, for which the maximum mass of the compact star reaches 2.2 M2.2~M_\odot, in accordance with most recent constraints. In model nlNJLA such a phase cannot be realised because the phase transition onset is at low densities, before the hyperon threshold density is passed. We discuss possible consequences of the hybrid equation of state for the deconfinement phase transition in symmetric matter as it will be probed in future heavy-ion collisions at FAIR, NICA and corresponding energy scan programs at the CERN and RHIC facilities.Comment: 37 pages, 13 figures, 1 table, references added, text and figures revised, version accepted for publication in Phys. Rev.

    LOCV calculation for Beta-stable matter at finite temperature

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    The method of lowest-order constrained variational, which predicts reasonably the nuclear matter semi-empirical data is used to calculate the equation of state of beta-stable matter at finite temperature. The Reid soft-core with and without the N-Δ\Delta interactions which fits the N-N scattering data as well as the UV14UV_{14} potential plus the three-nucleon interaction are considered in the nuclear many-body Hamiltonian. The electron and muon are treated relativistically in the total Hamiltonian at given temperature, to make the fluid electrically neutral and stable against beta decay. The calculation is performed for a wide range of baryon density and temperature which are of interest in the astrophysics. The free energy, entropy, proton abundance, etc. of nuclear beta-stable matter are calculated. It is shown that by increasing the temperature, the maximum proton abundance is pushed to the lower density while the maximum itself increases as we increase the temperature. The proton fraction is not enough to see any gas-liquid phase transition. Finally we get an overall agreement with other many-body techniques, which are available only at zero temperature.Comment: LaTex, 20 page

    T-lymphocyte Tyrosine Hydroxylase Regulates T H 17 T-lymphocytes During Repeated Social Defeat Stress

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    Posttraumatic stress disorder (PTSD) is a debilitating psychiatric disorder which results in deleterious changes to psychological and physical health. Patients with PTSD are especially susceptible to life-threatening co-morbid inflammation-driven pathologies, such as autoimmunity, while also demonstrating increased T-helper 17 (TH17) lymphocyte-driven inflammation. While the exact mechanism of this increased inflammation is unknown, overactivity of the sympathetic nervous system is a hallmark of PTSD. Neurotransmitters of the sympathetic nervous system (i.e., catecholamines) can alter T-lymphocyte function, which we have previously demonstrated to be partially mitochondrial redox-mediated. Furthermore, we have previously elucidated that T-lymphocytes generate their own catecholamines, and strong associations exist between tyrosine hydroxylase (TH; the rate-limiting enzyme in the synthesis of catecholamines) and pro-inflammatory interleukin 17A (IL-17A) expression within purified T-lymphocytes in a rodent model of psychological trauma. Therefore, we hypothesized that T-lymphocyte-generated catecholamines drive TH17 T-lymphocyte polarization through a mitochondrial superoxide-dependent mechanism during psychological trauma. To test this, T-lymphocyte-specific TH knockout mice (THT-KO) were subjected to psychological trauma utilizing repeated social defeat stress (RSDS). RSDS characteristically increased tumor necrosis factor-α (TNFα), IL-6, IL-17A, and IL-22, however, IL-17A and IL-22 (TH17 produced cytokines) were selectively attenuated in circulation and in T-lymphocytes of THT-KO animals. When activated ex vivo, secretion of IL-17A and IL-22 by THT-KO T-lymphocytes was also found to be reduced, but could be partially rescued with supplementation of norepinephrine specifically. Interestingly, THT-KO T-lymphocytes were still able to polarize to TH17 under exogenous polarizing conditions. Last, contrary to our hypothesis, we found RSDS-exposed THT-KO T-lymphocytes still displayed elevated mitochondrial superoxide, suggesting increased mitochondrial superoxide is upstream of T-lymphocyte TH induction, activity, and TH17 regulation. Overall, these data demonstrate TH in T-lymphocytes plays a critical role in RSDS-induced TH17 T-lymphocytes and offer a previously undescribed regulator of inflammation in RSDS

    Controlling surface statistical properties using bias voltage: Atomic force microscopy and stochastic analysis

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    The effect of bias voltages on the statistical properties of rough surfaces has been studied using atomic force microscopy technique and its stochastic analysis. We have characterized the complexity of the height fluctuation of a rough surface by the stochastic parameters such as roughness exponent, level crossing, and drift and diffusion coefficients as a function of the applied bias voltage. It is shown that these statistical as well as microstructural parameters can also explain the macroscopic property of a surface. Furthermore, the tip convolution effect on the stochastic parameters has been examined.Comment: 8 pages, 11 figures
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