190 research outputs found

    Bisphenol A: Quantification in Complex Matrices and Removal by Anaerobic Sludges

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    The endocrine disruptor bisphenol A (BPA) is one of the most commonly found micropollutants in the environment. However, the biodegradation of BPA under anaerobic (methanogenic) conditions is still an understudied process in wastewater treatment systems. The current study thus addresses the need for a simple and user-friendly analytical method for the rapid and accurate quantification of BPA in complex matrices such as digested and co-digester sludges. We established a microwave-assisted extraction method, followed by derivatization and gas chromatography–mass spectrometry to quantify BPA by comparing it with a deuterated internal standard. The BPA removal capabilities of three digester sludges and three co-digester sludges were examined under mesophilic methanogenic conditions in biogas plants. The endogenous BPA concentration (dry weight) ranged from 1596 to 10,973 ”g kg −1 in digested sewage sludges, and from below the limit of quantification to 9069 ”g kg −1 in co-digester sludges. When BPA was added to the sludges, the removal capabilities ranged from not significant to 50% after 21 days of incubation. Biogas production was unaffected by the addition of BPA (228 ”g kg −1 ) to the aqueous sludge. The study demonstrated that BPA could be removed under anaerobic conditions in accustomed inoculates. The findings have far-reaching implications for understanding BPA persistence and detoxification under anaerobic conditions

    Effect of pancreatic and/or renal transplantation on diabetic autonomic neuropathy

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    Thirty-nine Type 1 (insulin-dependent) diabetic patients were studied prospectively after simultaneous pancreas and kidney (n=26) and kidney grafting alone (n=13) by measuring heart rate variation during various manoeuvers and answering a standardized questionnaire every 6 to 12 months post-transplant. While age, duration of diabetes, and serum creatinine (168.1±35.4 vs 132.7±17.7 mgrmol/l) were comparable, haemoglobin A1 levels were significantly lower (6.6±0.2 vs 8.5±0.3%; p<0.01) and the mean observation time longer (35±2 vs 25±3 months; p<0.05) in the pancreas recipients when compared with kidney transplanted patients. Heart rate variation during deep breathing, lying/standing and Valsalva manoeuver were very similar in both groups initially and did not improve during follow-up. However, there was a significant reduction in heart rate in the pancreas recipient group. Autonomic symptoms of the gastrointestinal and thermoregulatory system improved more in the pancreas grafted subjects, while hypoglycaemia unawareness deteriorated in the kidney recipients. This study suggests that long-term normoglycaemia by successful pancreatic grafting is able to halt the progression of autonomic dysfunction

    Recent progress and emerging application areas for lithium-sulfur battery technology

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    Electrification is progressing significantly within the present and future vehicle sectors such as large commercial vehicles (e. g. trucks and busses), high altitude long endurance (HALE), high altitude pseudo satellites (HAPS), and electric vertical take‐off and landing (eVTOL). The battery systems performance requirements differ across these applications in terms of power, cycle life, system cost, etc. However, the need for high gravimetric energy density, 400 Wh kg−1 and beyond, is common across them all, since it will enable vehicles to achieve extended range, longer mission duration, lighter weight or increased payload. The system level requirements of these emerging applications can be broken down into the component level developments required to integrate Li‐S technology as the power system of choice. In order to adapt the batteries’ properties, such as energy and power density, to the respective application, the academic research community has a key role to play in component level development. However, materials and component research must be conducted within the context of a viable Li‐S cell system. Herein, the key performance benefits, limitations, modelling and recent progress of the Li‐S battery technology and its adaption towards real world application are discusse

    Electron Cryotomography of Bacterial Secretion Systems

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    In biology, function arises from form. For bacterial secretion systems, which often span two membranes, avidly bind to the cell wall, and contain hundreds of individual proteins, studying form is a daunting task, made possible by electron cryotomography (ECT). ECT is the highest-resolution imaging technique currently available to visualize unique objects inside cells, providing a three-dimensional view of the shapes and locations of large macromolecular complexes in their native environment. Over the past 15 years, ECT has contributed to the study of bacterial secretion systems in two main ways: by revealing intact forms for the first time and by mapping components into these forms. Here we highlight some of these contributions, revealing structural convergence in type II secretion systems, structural divergence in type III secretion systems, unexpected structures in type IV secretion systems, and unexpected mechanisms in types V and VI secretion systems. Together, they offer a glimpse into a world of fantastic forms—nanoscale rotors, needles, pumps, and dart guns—much of which remains to be explored

    Aconitate decarboxylase 1 participates in the control of pulmonary Brucella infection in mice

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    Brucellosis is one of the most widespread bacterial zoonoses worldwide. Here, our aim was to identify the effector mechanisms controlling the early stages of intranasal infection with Brucella in C57BL/6 mice. During the first 48 hours of infection, alveolar macrophages (AMs) are the main cells infected in the lungs. Using RNA sequencing, we identified the aconitate decarboxylase 1 gene ( Acod1 ;also known as Immune responsive gene 1), as one of the genes most upregulated in murine AMs in response to B .melitensis infection at 24 hours post-infection. Upregulation of Acod1 was confirmed by RT-qPCR in lungs infected with B .melitensis and B .abortus .We observed that Acod1 -/- C57BL/6 mice display a higher bacterial load in their lungs than wild-type (wt) mice following B .melitensis or B .abortus infection, demonstrating that Acod1 participates in the control of pulmonary Brucella infection. The ACOD1 enzyme is mostly produced in mitochondria of macrophages, and converts cis-aconitate, a metabolite in the Krebs cycle, into itaconate. Dimethyl itaconate (DMI), a chemically-modified membrane permeable form of itaconate, has a dose-dependent inhibitory effect on Brucella growth in vitro .Interestingly, structural analysis suggests the binding of itaconate into the binding site of B .abortus isocitrate lyase. DMI does not inhibit multiplication of the isocitrate lyase deletion mutant Δ aceA B .abortus in vitro .Finally, we observed that, unlike the wt strain, the Δ aceA B .abortus strain multiplies similarly in wt and Acod1 -/- C57BL/6 mice. These data suggest that bacterial isocitrate lyase might be a target of itaconate in AMs.info:eu-repo/semantics/publishe
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