173 research outputs found
Content of total iron, copper and manganese in liver of animals during hypokinesia, muscle activity and process of recovery
It is shown that the content of total iron, copper and manganese in the liver of animals is altered depending on the intensity and duration of their swimming. Hypodynamia for 7 days does not alter the concentration of iron, but sufficiently increases the content of copper and manganese. The barometric factor effectively influences the maintenance of constancy in the content of microelements accumulated in the liver after intensive muscle activity
AlGaAs/GaAs photovoltaic converters for high power narrowband radiation
AlGaAs/GaAs-based laser power PV converters intended for operation with high-power (up to 100 W/cm(2)) radiation were fabricated by LPE and MOCVD techniques. Monochromatic (lambda = 809 nm) conversion efficiency up to 60% was measured at cells with back surface field and low (x = 0.2) Al concentration 'window'. Modules with a voltage of 4 V and the efficiency of 56% were designed and fabricated
Methods for stability analysis of nonlinear control systems with time delay for application in automatic devices
Anti-Inflammatory Effects of Concentrated Ethanol Extracts of Edelweiss ( Leontopodium alpinum
Edelweiss (Leontopodium alpinum Cass.) is traditionally employed in folk medicine as an anti-inflammatory remedy. In nature, the plant is sparsely available and protected; therefore production of callus cultures was established. A concentrated ethanolic extract of culture homogenate, with leontopodic acid representing 55 ± 2% of the total phenolic fraction (ECC55), was characterized for anti-inflammatory properties in primary human keratinocytes (PHKs) and endotheliocytes (HUVECs). Inflammatory responses were induced by UVA+UVB, lipopolysaccharide (LPS), oxidized low-density lipoprotein (oxLDL), and a mixture of proinflammatory cytokines. Trichostatin A, a sirtuin inhibitor, was used to induce keratinocyte inflammatory senescence. ECC55 (10–50 μg/mL) protected PHK from solar UV-driven damage, by enhancing early intracellular levels of nitric oxide, although not affecting UV-induced expression of inflammatory genes. Comparison of the dose-dependent inhibition of chemokine (IL-8, IP-10, MCP-1) and growth factor (GM-CSF) release from PHK activated by TNFα + IFNγ showed that leontopodic acid was mainly responsible for the inhibitory effects of ECC55. Sirtuin-inhibited cell cycle, proliferation, and apoptosis markers were restored by ECC55. The extract inhibited LPS-induced IL-6 and VCAM1 genes in HUVEC, as well as oxLDL-induced selective VCAM1 overexpression. Conclusion. Edelweiss cell cultures could be a valuable source of anti-inflammatory substances potentially applicable for chronic inflammatory skin diseases and bacterial and atherogenic inflammation
Влияние диметилформамида на пероксидазное окисление тетраметилбензидина и его ингибирование
The kinetics of the peroxidase-catalyzed tetramethylbanzidine (TMB) oxidation has been studied in phosphate-citrate buffer (pH 6.0 and 6.4), containing 3-25 % of dimethylformamide (DMF), at 20 °C. The relationship between DMF concentration and kinetic parameters kcat, KM and kcat/KM has been determined. It has been shown that lg kcat linearly decreased with increasing DMF concentration, whereas KM value did not change. Kinetics of peroxidase-dependent TMB oxidation inhibition by two synthetic sulphur-containing α-tocopherol analogs at various DMF concentrations (3-25%) has been studed, and the inhibition constants Ki have been determined. It has been shown that with increasing DMF concentration, Ki values decreased from 15.8 to 3.2 μM. This fact is accounted for by DMF effect on the structures of peroxidase and inhibitors, as well as on their interaction, where the electrostatic interactions play a great part, since lgKi is linearly dependent on (ε-1)/(2ε+1), where ε is the dielectric constant of the reaction medium.В смеси фосфатно-цитратного буфера (рН 6,0 и 6,4) с диметилформамидом (ДМФ, 3-30 %) при 20 °С изучена кинетика пероксидазного окисления тетраметилбензидина (ТМБ) и определены кинетические параметры kcat, константа Михаэлиса KM и kcat/ KM в зависимости от концентрации ДМФ. Показано, что lgkcat линейно уменьшается с ростом содержания ДМФ, а KM практически не зависит от него. Изучена кинетика ингибирования окисления ТМБ двумя синтетическими аналогами α-токоферола и определены константы ингибирования Ki, меняющиеся с ростом ДМФ от 15,8 до 3,2 мкМ, что объясняется действием ДМФ на структуру пероксида-зы и ингибиторов, а также их взаимодействие, в котором важная роль принадлежит электростатическим силам, так как lgKi линейно зависит от (ε-1)/(2ε+1), где ε - диэлектрическая проницаемость среды
Advances in thermosonication for the inactivation of endogenous enzymes in foods
The main objective of food pasteurization is to inactivate pathogens and reduce spoilage organisms. For certain foods (e.g. orange juice) and in particular with emerging non-thermal technologies such as ultrasound and high pressure processing, endogenous and deteriorative enzymes can be very resistant. Therefore, enzymes should also be used as pasteurization references to avoid spoilage of processed foods during storage. Thus, endogenous food enzymes should be inactivated to increase its shelf life. In this chapter a review of the effects of thermo-sonication (simultaneous ultrasound and heat) on food enzymes was carried out. The ultrasound treatment denatures the enzyme, resulting in enzyme conformational changes and decrease in its activity. A variety of foods has been processed by ultrasound without heat, thermos-sonication and mano-thermo-sonication and the effect on enzymes is reviewed. Thermo-sonication and mano-thermo-sonication are recommended for enzyme inactivation, since ultrasound at room temperature is often ineffective against most food enzymes. The most relevant plant endogenous enzymes are pectinmethylesterase (PME), polygalacturonase (PG), polyphenoloxidase (PPO) and peroxidase (PRO), which are important for fruit and vegetable products. In addition lactoperoxidase (LPO), γ-glutamyltranspeptidase (GTP) and alkaline phosphatase (AP) from milk and dairy products are also reviewe
The Chemopreventive Effects of Protandim: Modulation of p53 Mitochondrial Translocation and Apoptosis during Skin Carcinogenesis
Protandim, a well defined dietary combination of 5 well-established medicinal plants, is known to induce endogenous antioxidant enzymes, such as manganese superoxide dismutase (MnSOD). Our previous studies have shown through the induction of various antioxidant enzymes, products of oxidative damage can be decreased. In addition, we have shown that tumor multiplicity and incidence can be decreased through the dietary administration of Protandim in the two-stage skin carcinogenesis mouse model. It has been demonstrated that cell proliferation is accommodated by cell death during DMBA/TPA treatment in the two-stage skin carcinogenesis model. Therefore, we investigated the effects of the Protandim diet on apoptosis; and proposed a novel mechanism of chemoprevention utilized by the Protandim dietary combination. Interestingly, Protandim suppressed DMBA/TPA induced cutaneous apoptosis. Recently, more attention has been focused on transcription-independent mechanisms of the tumor suppressor, p53, that mediate apoptosis. It is known that cytoplasmic p53 rapidly translocates to the mitochondria in response to pro-apoptotic stress. Our results showed that Protandim suppressed the mitochondrial translocation of p53 and mitochondrial outer membrane proteins such as Bax. We examined the levels of p53 and MnSOD expression/activity in murine skin JB6 promotion sensitive (P+) and promotion-resistant (P-) epidermal cells. Interestingly, p53 was induced only in P+ cells, not P- cells; whereas MnSOD is highly expressed in P- cells when compared to P+ cells. In addition, wild-type p53 was transfected into JB6 P- cells. We found that the introduction of wild-type p53 promoted transformation in JB6 P- cells. Our results suggest that suppression of p53 and induction of MnSOD may play an important role in the tumor suppressive activity of Protandim
СИНТЕЗ РЕЧЕПОДОБНЫХ СИГНАЛОВ НА БЕЛОРУССКОМ ЯЗЫКЕ
The methods of synthesis of speech-like signal on the basis of allophones are anylized. The development urgency of speech-like signals synthesis in the Belarusian language is grounded. The methodology of forming the base of allophones in the Belarusian language with the phonetic features of the Belarusian language is described.Проанализированы методы синтеза речеподобных сигналов по базе аллофонов. Обоснована актуальность разработки синтеза речеподобных сигналов на белорусском языке. Изложена методология формирования базы аллофонов на белорусском языке с учетом фонетических особенностей белорусского языка
The impact of polyphenols on chondrocyte growth and survival: a preliminary report
Background: Imbalances in the functional binding of fibroblast growth factors (FGFs) to their receptors (FGFRs) have consequences for cell proliferation and differentiation that in chondrocytes may lead to degraded cartilage. The toxic, proinflammatory, and oxidative response of cytokines and FGFs can be mitigated by dietary polyphenols.
Objective: We explored the possible effects of polyphenols in the management of osteoarticular diseases using a model based on the transduction of a mutated human FGFR3 (G380R) in murine chondrocytes. This mutation is present in most cases of skeletal dysplasia and is responsible for the overexpression of FGFR3 that, in the presence of its ligand, FGF9, results in toxic effects leading to altered cellular growth.
Design: Different combinations of dietary polyphenols derived from plant extracts were assayed in FGFR3 (G380R) mutated murine chondrocytes, exploring cell survival, chloride efflux, extracellular matrix (ECM) generation, and grade of activation of mitogen-activated protein kinases.
Results: Bioactive compounds from Hibiscus sabdariffa reversed the toxic effects of FGF9 and restored normal growth, suggesting a probable translation to clinical requests in humans. Indeed, these compounds activated the intracellular chloride efflux, increased ECM generation, and stimulated cell proliferation. The inhibition of mitogen-activated protein kinase phosphorylation was interpreted as the main mechanism governing these beneficial effects.
Conclusions: These findings support the rationale behind the encouragement of the development of drugs that repress the overexpression of FGFRs and suggest the dietary incorporation of supplementary nutrients in the management of degraded cartilage.The authors are grateful for the constant support provided by the Hospital Universitari de Sant Joan and the Universitat Rovira i Virgili. Salvador Fernández-Arroyo is the recipient of a Sara Borrell grant (CD12/00672) from the Instituto de Salud Carlos III, Madrid, Spain. The authors also thank the Andalusian Regional Government Council of Innovation and Science for the Excellence Project P11-CTS-7625 and Generalitat Valenciana for the project PROMETEO/2012/007. This work was also supported by projects of the Fundación Areces and the Fundación MAGAR
Estimation of the overall kinetic parameters of enzyme inactivation using an isoconversional method
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