374 research outputs found

    Разработка технологии получения твердой дозированной лекарственной формы Грамицидина С методом влажной грануляции во взвешенном слое

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    Работа посвящена исследованию процесса грануляции пептидного антибиотика с бета-циклодекстрином во взвешенном слое. Получен и охарактеризован комплекс включения антибиотика с бета-циклодекстрином. Изучены параметры, влияющие на эффективность процесса инкапсуляции. Анализ высвобождения показал растворимость грамицидина С в водном растворе. В работе были исследованы технологические свойства смеси и свойства таблетированной формы. Разработана технологическая схема производства.In this study granulation of a peptide antibiotic with beta-cyclodextrin in bed fluidization was investigated. The inclusion complex of antibiotic with beta-cyclodextrin was obtained and characterized. The parameters of granulation affecting on encapsulation process were studied. A release analysis showed the solubility of gramicidin S in aqueous solution. The processability of the mixture was investigated and the property of the bulk product was analyzed. The technological scheme of production is developed

    Evaluation of the efficiency of sludge lignin plasma disposal process

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    This article shows the review and analysis of literature on methods of sludge lignin utilization. It is the product obtained after processing of cellulose. As a result of the calculations the optimal compositions of water, organic materials with mechanical impurities with adiabatic combustion temperature of about 1200 K were determined. With the help of obtained results experimental studies were carried out in a plasma catalytic reactor and the reactor operation was optimized. The results can be used to build industrial plants on the basis of plasma catalytic reactors for utilization of sludge lignin

    Development of measures to prevent the occurrence of an emergency at an automobile gas filling station

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    В процессе исследования проводились анализ обеспечения безопасности функционирования АГЗС; анализ опасных факторов при эксплуатации АГЗС. В результате исследования произведен анализ опасных факторов на АГЗС. Проведена оценка вероятности возникновения аварийных ситуаций на АГЗС. Предложены мероприятия по предупреждению возникновения чрезвычайной ситуации на объекте.In the course of the researchthe analysis of ensuring the safety of the functioning of the filling station was carried out; analysis of hazardous factors during the operation of gas stations. As a result of the studyan analysis of hazardous factors at the gas station was made. The assessment of the likelihood of emergencies at the filling station was carried out. Measures are proposed to prevent an emergency at the facility

    A fluorescent polarization-based assay for the identification of disruptors of the RCAN1/calcineurin A protein complex

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    5 pages, 4 figures, a table. 19891949 [PubMed]Calcineurin is a Ca(2+)/calmodulin-dependent serine/threonine protein phosphatase involved in many biological processes and developmental programs, including immune response. One of the most studied substrates of calcineurin is the transcription factor NFAT (nuclear factor of activated T cells) responsible for T-cell activation. Different anticalcineurin drugs, such as cyclosporine A and FK506, are the most commonly used immunosuppressants in transplantation therapies. Unfortunately, their mechanism of action, completely blocking the calcineurin phosphatase activity while also requiring continuous administration, bears severe side effects. During recent years, the family of regulators of calcineurin (RCAN) has been described and studied extensively as modulators of calcineurin signaling pathways. The RCAN1 region, spanning amino acids 198 to 218 and responsible for inhibiting the calcineurin-NFAT signaling pathway in vivo, has been identified. An RCAN1-derived peptide spanning this sequence interferes with the calcineurin-NFAT interaction without affecting the general calcineurin phosphatase activity. Here we report the development of an optimized in vitro high-throughput fluorescence polarization assay based on the disruption of the RCAN1(198-218)-CnA interaction for identifying molecules with immunosuppressant potential. This approach led us to identify dipyridamole as a disruptor of such interaction. Moreover, three small molecules with a potential immunosuppressive effect were also identifiedThis work was supported by grants from Fundació La Marató de TV3 (Ref. 030830), the Spanish Ministry of Education and Science (SAF2006-04815, BIO2004-00998, BIO2007-60066, CTQ2005-00995/BQU), the Fundación Mutua Madrileña 2007 and from the Generalitat de Catalunya (Ref. 2006 BE 00051)Peer reviewe

    Transport properties of Layer-Antiferromagnet CuCrS2: A possible thermoelectric material

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    The electrical, thermal conductivity and Seebeck coefficient of the quenched, annealed and slowly cooled phases of the layer compound CuCrS2 have been reported between 15K to 300K. We also confirm the antiferromagnetic transition at 40K in them by our magnetic measurements between 2K and 300K. The crystal flakes show a minimum around 100K in their in-plane resistance behavior. For the polycrystalline pellets the resistivity depends on their flaky texture and it attains at most 10 to 20 times of the room temperature value at the lowest temperature of measurement. The temperature dependence is complex and no definite activation energy of electronic conduction can be discerned. We find that the Seebeck coefficient is between 200-450 microV/K and is unusually large for the observed resistivity values of between 5-100 mOhm-cm at room temperature. The figure of merit ZT for the thermoelectric application is 2.3 for our quenched phases, which is much larger than 1 for useful materials. The thermal conductivity K is mostly due to lattice conduction and is reduced by the disorder in Cu- occupancy in our quenched phase. A dramatic reduction of electrical and thermal conductivity is found as the antiferromagnetic transition is approached from the paramagnetic region, and K subsequently rises in the ordered phase. We discuss the transport properties as being similar to a doped Kondo-insulator

    Metal hydrides for concentrating solar thermal power energy storage

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    The development of alternative methods for thermal energy storage is important for improving the efficiency and decreasing the cost for Concentrating Solar-thermal Power (CSP). We focus on the underlying technology that allows metal hydrides to function as Thermal Energy Storage (TES) systems and highlight the current state-of-the-art materials that can operate at temperatures as low as room-temperature and as high as 1100 oC. The potential of metal hydrides for thermal storage is explored while current knowledge gaps about hydride properties, such as hydride thermodynamics, intrinsic kinetics and cyclic stability, are identified. The engineering challenges associated with utilising metal hydrides for high-temperature thermal energy storage are also addressed

    Molecular biology of the blood-brain and the blood-cerebrospinal fluid barriers: similarities and differences

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    Efficient processing of information by the central nervous system (CNS) represents an important evolutionary advantage. Thus, homeostatic mechanisms have developed that provide appropriate circumstances for neuronal signaling, including a highly controlled and stable microenvironment. To provide such a milieu for neurons, extracellular fluids of the CNS are separated from the changeable environment of blood at three major interfaces: at the brain capillaries by the blood-brain barrier (BBB), which is localized at the level of the endothelial cells and separates brain interstitial fluid (ISF) from blood; at the epithelial layer of four choroid plexuses, the blood-cerebrospinal fluid (CSF) barrier (BCSFB), which separates CSF from the CP ISF, and at the arachnoid barrier. The two barriers that represent the largest interface between blood and brain extracellular fluids, the BBB and the BCSFB, prevent the free paracellular diffusion of polar molecules by complex morphological features, including tight junctions (TJs) that interconnect the endothelial and epithelial cells, respectively. The first part of this review focuses on the molecular biology of TJs and adherens junctions in the brain capillary endothelial cells and in the CP epithelial cells. However, normal function of the CNS depends on a constant supply of essential molecules, like glucose and amino acids from the blood, exchange of electrolytes between brain extracellular fluids and blood, as well as on efficient removal of metabolic waste products and excess neurotransmitters from the brain ISF. Therefore, a number of specific transport proteins are expressed in brain capillary endothelial cells and CP epithelial cells that provide transport of nutrients and ions into the CNS and removal of waste products and ions from the CSF. The second part of this review concentrates on the molecular biology of various solute carrier (SLC) transport proteins at those two barriers and underlines differences in their expression between the two barriers. Also, many blood-borne molecules and xenobiotics can diffuse into brain ISF and then into neuronal membranes due to their physicochemical properties. Entry of these compounds could be detrimental for neural transmission and signalling. Thus, BBB and BCSFB express transport proteins that actively restrict entry of lipophilic and amphipathic substances from blood and/or remove those molecules from the brain extracellular fluids. The third part of this review concentrates on the molecular biology of ATP-binding cassette (ABC)-transporters and those SLC transporters that are involved in efflux transport of xenobiotics, their expression at the BBB and BCSFB and differences in expression in the two major blood-brain interfaces. In addition, transport and diffusion of ions by the BBB and CP epithelium are involved in the formation of fluid, the ISF and CSF, respectively, so the last part of this review discusses molecular biology of ion transporters/exchangers and ion channels in the brain endothelial and CP epithelial cells
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