Altered capacity for h 2 s production during the spontaneous differentiation of caco-2 cells to colonocytes due to reciprocal regulation of cbs and selenbp1

Hydrogen sulfide (H 2 S) has been proposed to promote tumor growth. Elevated H 2 S levels have been detected in human colorectal cancer (CRC) biopsies, resulting from the selective upregulation of cystathionine β-synthase (CBS). In contrast, the recently identified novel H 2 S-generating enzyme, selenium-binding protein 1 (SELENBP1), is largely suppressed in tumors. Here, we provide the first comparative analysis of the four human H 2 S-producing enzymes and the key H 2 S-catabolizing enzyme, sulfide:quinone oxidoreductase (SQOR), in Caco-2 human colorectal adenocarcinoma cells. The gene expression pattern of proliferating Caco-2 cells parallels that of CRC, while confluent cells undergo spontaneous differentiation to a colonocyte-like phenotype. SELENBP1 and SQOR were strongly upregulated during spontaneous differentiation, whereas CBS was downregulated. Cystathionine γ-lyase and 3-mercaptopyruvate sulfurtransferase remained unaffected. Terminally differentiated cells showed an enhanced capacity to produce H 2 S from methanethiol and homocysteine. Differentiation induced by exposure to butyrate also resulted in the upregulation of SELENBP1, accompanied by increased SELENBP1 promoter activity. In contrast to spontaneous differentiation, however, butyrate did not cause downregulation of CBS. In summary, SELENBP1 and CBS are reciprocally regulated during the spontaneous differentiation of Caco-2 cells, thus paralleling their opposing regulation in CRC. Butyrate exposure, while imitating some aspects of spontaneous differentiation, does not elicit the same expression patterns of genes encoding H 2 S-modulating enzymes

Разработка автоматической установки газового пожаротушения в помещениях химически опасных объектов

Целью работы является разработка автоматической установки газового пожаротушения на складе химических реактивов. В работе произведен анализ нормативных документов в области обеспечения пожарной безопасности, проанализированы системы автоматического пожаротушения, рассчитаны количества модулей пожаротушения, площади дополнительных проемов в помещении для сброса избыточного давления, определены мощности подачи огнетушащего вещества.The aim of the work is to develop an automatic gas fire extinguishing system in a chemical reagent warehouse. The paper analyzes the regulatory documents in the field of fire safety, analyzes the automatic fire extinguishing systems, calculates the number of fire extinguishing modules, the area of additional openings in the room for relieving excess pressure, and determines the supply capacity of the extinguishing agent

How battery calorimeters can help in advancing thermal management and safety of cells and packs

With increasing energy density the thermal management of Li-ion batteries is becoming more and more important, because the thermal runaway can cause an ignition or even explosion of the battery with simultaneous release of toxic gases. In the last five years we have established battery calorimetry as a powerful and versatile electrochemical-thermal characterization technique, which allows both advancements for the thermal management and the safety of batteries. With six adiabatic Accelerating Rate Calorimeters (ARC) of different sizes combined with cyclers the IAM-AWP now operates Europe’s largest battery calorimeter center, which enables the evaluation of thermodynamic, thermal and safety data on material, cell and pack level. Calorimetry is very important as it is fundamental to obtain quantitative data on the thermal behaviour – you need to know how many watts a cell or a pack will generate and dissipate under certain conditions. This information can then be used to define the requirements for cooling and thermal management and adapt them accordingly. It will be shown how sophisticated battery calorimetry combined with thermography for the spatial temperature variation allows finding new and quantitative correlations between different critical thermally and safety related parameters that will help to design safer systems. In addition it will be explained how calorimeters allow studying the thermal runaway propagation in order to develop and qualify suitable countermeasures, such as heat protection barriers, which is currently becoming a very hot topic. The top 3 learning \u27take aways\u27 are: • Delegates will get insights into the use of battery calorimetry to provide quantitative thermal and safety data for cell and packs. • Delegates will understand how these data help to improve the thermal management and can give guidelines for safer systems • Delegates will understand that these data combined with better BMS diagnostics provide a powerful tool for the thermal runaway prevention

How Calorimetry can help in Battery Research

With increasing energy density the safety and the thermal management of Li-ion batteries is becoming more and more important, because the thermal runaway can cause an ignition or even explosion of the battery with simultaneous release of toxic gases. In the last ten years, we have established battery calorimetry as a versatile characterization technique, which allows advancements for the thermal management and the safety of batteries. With six adiabatic Accelerating Rate Calorimeters of different sizes and two sensitive Tian-Calvet calorimeters combined with cyclers we operate Europe’s largest battery calorimeter center, which enables the evaluation of thermodynamic, thermal and safety data on material, cell and pack level under quasiadiabatic and isoperibolic environments for both normal and abuse conditions (thermal, electrical, mechanical). Calorimetry allows the collection of quantitative data required for optimum battery performance and safety. This information is applied to define the requirements for thermal management. It will be explained how calorimeters can be used for studies on heat generation and dissipation of Li-ion cells. It will be shown that by measuring the specific heat capacity and the heat transfer coefficient the measured temperature data during cycling can be converted into generated and dissipated heat data, which are needed for the adjustment of the thermal management systems. It will be presented how battery calorimeters provide thermodynamic and thermal stability data on materials level, e.g. of anodes, cathodes or electrolytes or there combinations and allow to perform safety tests on cell and pack level by applying thermal, mechanical or electrical abuse conditions. The studies on materials level are especially important for Post-Li cells, which make use of more abundant materials, such as sodium or magnesium instead of Li, nickel and cobalt, because these data help to develop safe cells from the beginning all along the value chain. For the advanced Li-ion technology, a holistic safety assessment is in the focus, because the thermal runaway can have multiple interacting causes and effects. A test in the calorimeter reveals the entire process of the thermal runaway with the different stages of exothermic reactions. As a result of the different tests quantitative and system relevant data for temperature, heat and pressure development of materials and cells are provided. In addition it will be explained how calorimeters allow studying the thermal runaway propagation in order to develop and qualify suitable countermeasures, such as heat protection barriers, which is currently becoming a very hot topic

SEMO ‐1, a novel methanethiol oxidase in Caenorhabditis elegans , is a pro‐aging factor conferring selective stress resistance

Methanethiol is a toxic gas produced through bacterial degradation of sulfur‐containing amino acids. Applying a novel enzymatic assay, we here identified a methanethiol oxidase (MTO) that catalyzes the degradation of methanethiol in the nematode Caenorhabditis elegans ( C. elegans ). The corresponding protein, Y37A1B.5, previously characterized as a C. elegans ortholog of human selenium‐binding protein 1 (SELENBP1), was renamed SEMO‐1 (SELENBP1 ortholog with methanethiol oxidase activity). Worms rendered deficient in SEMO‐1 not only showed decreased hydrogen sulfide production from methanethiol catabolism but they were also more resistant to oxidative stress and had an elevated life span. In contrast, resistance to selenite was significantly lowered in SEMO‐1‐deficient worms. Naturally occurring mutations of human SELENBP1 were introduced to recombinant SEMO‐1 through site‐directed mutagenesis and resulted in loss of its MTO activity, indicating a similar enzymatic mechanism for SELENBP1 and SEMO‐1. In summary, SEMO‐1 confers resistance to toxic selenite and the ability to metabolize toxic methanethiol. These beneficial effects might be a trade‐off for its negative impact on C. elegans life span

On the anomalous optical conductivity dispersion of electrically conducting polymers: Ultra-wide spectral range ellipsometry combined with a Drude-Lorentz model

Electrically conducting polymers (ECPs) are becoming increasingly important in areas such as optoelectronics, biomedical devices, and energy systems. Still, their detailed charge transport properties produce an anomalous optical conductivity dispersion that is not yet fully understood in terms of physical model equations for the broad range optical response. Several modifications to the classical Drude model have been proposed to account for a strong non-Drude behavior from terahertz (THz) to infrared (IR) ranges, typically by implementing negative amplitude oscillator functions to the model dielectric function that effectively reduce the conductivity in those ranges. Here we present an alternative description that modifies the Drude model via addition of positive-amplitude Lorentz oscillator functions. We evaluate this so-called Drude-Lorentz (DL) model based on the first ultra-wide spectral range ellipsometry study of ECPs, spanning over four orders of magnitude: from 0.41 meV in the THz range to 5.90 eV in the ultraviolet range, using thin films of poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:Tos) as a model system. The model could accurately fit the experimental data in the whole ultrawide spectral range and provide the complex anisotropic optical conductivity of the material. Examining the resonance frequencies and widths of the Lorentz oscillators reveals that both spectrally narrow vibrational resonances and broader resonances due to localization processes contribute significantly to the deviation from the Drude optical conductivity dispersion. As verified by independent electrical measurements, the DL model accurately determines the electrical properties of the thin film, including DC conductivity, charge density, and (anisotropic) mobility. The ellipsometric method combined with the DL model may thereby become an effective and reliable tool in determining both optical and electrical properties of ECPs, indicating its future potential as a contact-free alternative to traditional electrical characterization. © The Royal Society of Chemistry 2019

On the anomalous optical conductivity dispersion of electrically conducting polymers: Ultra-wide spectral range ellipsometry combined with a Drude-Lorentz model

Electrically conducting polymers (ECPs) are becoming increasingly important in areas such as optoelectronics, biomedical devices, and energy systems. Still, their detailed charge transport properties produce an anomalous optical conductivity dispersion that is not yet fully understood in terms of physical model equations for the broad range optical response. Several modifications to the classical Drude model have been proposed to account for a strong non-Drude behavior from terahertz (THz) to infrared (IR) ranges, typically by implementing negative amplitude oscillator functions to the model dielectric function that effectively reduce the conductivity in those ranges. Here we present an alternative description that modifies the Drude model via addition of positive-amplitude Lorentz oscillator functions. We evaluate this so-called Drude-Lorentz (DL) model based on the first ultra-wide spectral range ellipsometry study of ECPs, spanning over four orders of magnitude: from 0.41 meV in the THz range to 5.90 eV in the ultraviolet range, using thin films of poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:Tos) as a model system. The model could accurately fit the experimental data in the whole ultrawide spectral range and provide the complex anisotropic optical conductivity of the material. Examining the resonance frequencies and widths of the Lorentz oscillators reveals that both spectrally narrow vibrational resonances and broader resonances due to localization processes contribute significantly to the deviation from the Drude optical conductivity dispersion. As verified by independent electrical measurements, the DL model accurately determines the electrical properties of the thin film, including DC conductivity, charge density, and (anisotropic) mobility. The ellipsometric method combined with the DL model may thereby become an effective and reliable tool in determining both optical and electrical properties of ECPs, indicating its future potential as a contact-free alternative to traditional electrical characterization. © The Royal Society of Chemistry 2019