2,284 research outputs found

    From Micro to Macro-Contaminants: The Impact of Low-Energy Titanium Dioxide Photocatalysis Followed by Filtration on The Mitigation of Drinking Water Organics

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    This study evaluated strategies targeting macro- and micro-organic contaminant mitigation using low-energy titanium dioxide photocatalysis. Energy inputs of 1, 2, and 5 kWh m−3 resulted in incomplete oxidation of macro-organic natural organic matter, signified by greater reductions of UV254 and specific ultraviolet UV absorbance (SUVA) in comparison to dissolved organic carbon (DOC). The rate of UV254 removal was 3 orders of magnitude greater than the rate of DOC degradation. Incomplete oxidation improved operation of downstream filtration processes. Photocatalysis at 2 kWh m−3 increased the bed life of downstream granular activated carbon (GAC) filtration by 340% relative to direct filtration pretreatment. Likewise, photocatalysis operated ahead of microfiltration decreased fouling, resulting in longer filter run times. Using 2 kWh m−3 photocatalysis increased filter run time by 36 times in comparison to direct filtration. Furthermore, levels of DOC and UV254 in the membrane permeate improved (with no change in removal across the membrane) using low-energy photocatalysis pretreatments. While high-energy UV inputs provided high levels of removal of the estrogenic micro-organics estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynlestradiol (EE2), low-energy photocatalysis did not enhance removal of estrogens beyond levels achieved by photolysis alone. In the cases of E1 and E3, the addition of TiO2 as a photocatalyst reduced degradation rates of estrogens compared to UV photolysis. Overall, process electrical energy per order magnitude reductions (EEOs) greatly improved using photocatalysis, versus photolysis, for the macro-organics DOC, UV254, and SUVA; however, energy required for removal of estrogens was similar between photolysis and photocatalysis

    The exchanged EF-hands in calmodulin and troponin C chimeras impair the Ca2+-induced hydrophobicity and alter the interaction with Orai1: a spectroscopic, thermodynamic and kinetic study

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    Background Calmodulin (CaM) plays an important role in Ca2+-dependent signal transduction. Ca2+ binding to CaM triggers a conformational change, forming a hydrophobic patch that is important for target protein recognition. CaM regulates a Ca2+-dependent inactivation process in store-operated Ca2+entry, by interacting Orai1. To understand the relationship between Ca2+-induced hydrophobicity and CaM/Orai interaction, chimera proteins constructed by exchanging EF-hands of CaM with those of Troponin C (TnC) are used as an informative probe to better understand the functionality of each EF-hand. Results ANS was used to assess the context of the induced hydrophobic surface on CaM and chimeras upon Ca2+ binding. The exchanged EF-hands from TnC to CaM resulted in reduced hydrophobicity compared with wild-type CaM. ANS lifetime measurements indicated that there are two types of ANS molecules with rather distinct fluorescence lifetimes, each specifically corresponding to one lobe of CaM or chimeras. Thermodynamic studies indicated the interaction between CaM and a 24-residue peptide corresponding to the CaM-binding domain of Orail1 (Orai-CMBD) is a 1:2 CaM/Orai-CMBD binding, in which each peptide binding yields a similar enthalpy change (ΔH = −5.02 ± 0.13 kcal/mol) and binding affinity (Ka = 8.92 ± 1.03 × 105 M−1). With the exchanged EF1 and EF2, the resulting chimeras noted as CaM(1TnC) and CaM(2TnC), displayed a two sequential binding mode with a one-order weaker binding affinity and lower ΔH than that of CaM, while CaM(3TnC) and CaM(4TnC) had similar binding thermodynamics as CaM. The dissociation rate constant for CaM/Orai-CMBD was determined to be 1.41 ± 0.08 s−1 by rapid kinetics. Stern-Volmer plots of Orai-CMBD Trp76 indicated that the residue is located in a very hydrophobic environment but becomes more solvent accessible when EF1 and EF2 were exchanged. Conclusions Using ANS dye to assess induced hydrophobicity showed that exchanging EFs for all Ca2+-bound chimeras impaired ANS fluorescence and/or binding affinity, consistent with general concepts about the inadequacy of hydrophobic exposure for chimeras. However, such ANS responses exhibited no correlation with the ability to interact with Orai-CMBD. Here, the model of 1:2 binding stoichiometry of CaM/Orai-CMBD established in solution supports the already published crystal structure

    In-vitro validation and quantitative measurements of graded burn wounds on a porcine model using handheld laser speckle imaging

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    Burn wound severity can be difficult to assess and the diagnosis is usually subjective. Optical techniques have emerged as alternative methods for providing objective, non-contact assessment of burn wound severity. One such technique is Laser Speckle Imaging (LSI), which quantifies superficial blood flow using coherent laser light. We have previously demonstrated that LSI can be used to accurately assess burn wounds. However, LSI is conventionally used in static designs, such as cart-based or tripod mounted configurations, due to the susceptibility of LSI to motion artifact. This can limit the portability and usability of the device in a clinical. Handheld LSI can potentially overcome these limitations. However, accounting for motion artifact associated with user movement must be addressed to obtain accurate and reliable blood flow measurements. Please click Additional Files below to see the full abstract

    Управління загрозами фінансовій безпеці підприємства

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    Розроблено блок-схему алгоритму управління загрозами фінансовій безпеці підприємства; виділено основні етапи здійснення цього процесу: оцінювання, аналіз та управління. Визначено сутність, зміст, переваги та недоліки застосування методів оцінювання загроз фінансовій безпеці в системі фінансового менеджменту підприємства. Ключові слова: підприємство, фінансова безпека, загрози, оцінювання, аналіз, управління.Составлена блок-схема алгоритма управления угрозами финансовой безопасности предприятия. Выделены основные этапы осуществления данного процесса: оценивание, анализ и управление. Определены сущность, содержание, преимущества и недостатки методов оценивания угроз финансовой безопасности в системе финансового менеджмента предприятия. Ключевые слова: предприятие, финансовая безопасность, угрозы, оценивание, анализ, управление.Enterprise financial security threats management main terms essence and contents were defined on the basis of financial and economic literature analysis and generalization: enterprise financial security threats management is a multistage process, which includes evaluation, management and analysis of enterprise financial security threats management; evaluation of enterprise financial security threats is a process of identification of threats influence on enterprise financial security; analysis of enterprise financial security threats is a process of threats identification, which influence on enterprise financial security. It is established that the majority of modern domestic and foreign scientists consider two groups of enterprise financial security threats estimation: qualitative or subjective (expert, probabilistic (concerning loss, favorable possibilities), consequences analysis) and quantitative or objective (statistical, analytical, rating, expense expediency, analogues, decision tree, normative). Comparative analysis of qualitative and quantitative enterprise financial security threats estimation enables to detect that use either of them has its own advantages and disadvantages. Some methods require using the considerable mass data and at the same time leave out of the account the time factor; others are insufficiently developed for using in the domestic economic conditions. Therefore the choice of the method is made only owing to the purpose of the enterprise financial security threats estimation. It is proved that the methods of the enterprise financial security threats management could be divided into three groups: reduction, maintenance and transmission. Reduction of enterprise financial security threats level provides preventive management and logistical measures implementation as to unfavorable events in financial and economic activities prevention or negative consequences liquidation. As measures, implemented for enterprise financial security threats level maintaining, could be referred the following: getting loans on compensation for losses, which enterprise got as a result of unforeseen, unfavorable events in its financial and economic activities, resumption of output production (goods, works, services) with the help of finance and credit establishments activities, government grants etc. Keywords: enterprise, financial security, threats, evaluation, analysis, management

    Temporally Programmed CD8α+ DC Activation Enhances Combination Cancer Immunotherapy

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    Numerous synergistic cancer immunotherapy combinations have been identified, but the effects of relative dose timing are rarely considered. In established syngeneic mouse tumor models, we found that staggering interferon-α (IFNα) administration after, rather than before or simultaneously with, serum-persistent interleukin-2 (IL-2) and tumor-specific antibody significantly increased long-term survival. Successful combination therapy required IFNα-induced activation of cross-presenting CD8α[superscript +] dendritic cells (DCs) following the release of antigenic tumor debris by the IL-2- and antibody-mediated immune response. Due to decreased phagocytic ability post-maturation, DCs activated too early captured less antigen and could not effectively prime CD8[superscript +] T cells. Temporally programming DC activation to occur after tumoricidal activity enhanced tumor control by multiple distinct combination immunotherapies, highlighting dose schedule as an underappreciated factor that can profoundly affect the success of multi-component immunotherapies.National Cancer Institute (U.S.) (Grants NCI CA174795 and CA101830)Ludwig Center for Molecular Oncology at MIT (Graduate Fellowship)Thomas and Stacey Siebel Foundation (Scholarship)National Science Foundation (U.S.). Graduate Research Fellowship ProgramHertz Foundation (Fellowship

    Th17 Cell Response in SOD1G93A Mice following Motor Nerve Injury

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    An increased risk of ALS has been reported for veterans, varsity athletes, and professional football players. The mechanism underlying the increased risk in these populations has not been identified; however, it has been proposed that motor nerve injury may trigger immune responses which, in turn, can accelerate the progression of ALS. Accumulating evidence indicates that abnormal immune reactions and inflammation are involved in the pathogenesis of ALS, but the specific immune cells involved have not been clearly defined. To understand how nerve injury and immune responses may contribute to ALS development, we investigated responses of CD4(+) T cell after facial motor nerve axotomy (FNA) at a presymptomatic stage in a transgenic mouse model of ALS (B6SJL SOD1(G93A)). SOD1(G93A) mice, compared with WT mice, displayed an increase in the basal activation state of CD4(+) T cells and higher frequency of Th17 cells, which were further enhanced by FNA. In conclusion, SOD1(G93A) mice exhibit abnormal CD4(+) T cell activation with increased levels of Th17 cells prior to the onset of neurological symptoms. Motor nerve injury exacerbates Th17 cell responses and may contribute to the development of ALS, especially in those who carry genetic susceptibility to this disease
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