570 research outputs found

    Syntrophy drives the microbial electrochemical oxidation of toluene in a continuous-flow "bioelectric well"

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    Microbial electrochemical technologies (MET) are promising for the remediation of groundwater pollutants such as petroleum hydrocarbons (PH). Indeed, MET can provide virtually inexhaustible electron donors or acceptors directly in the subsurface environment. However, the degradation mechanisms linking contaminants removal to electric current flow are still largely unknown, hindering the development of robust design criteria. Here, we analysed the degradation of toluene, a model PH, in a bioelectrochemical reactor known as "bioelectric well"operated in continuous-flow mode at various influent toluene concentrations. With increasing concentration of toluene, the removal rate increased while the current tended to a plateau, hence the columbic efficiency decreased. Operation at open circuit confirmed that the bioelectrochemical degradation of toluene proceeded via a syntrophic pathway involving cooperation between different microbial populations. First of all, hydrocarbon degraders quickly converted toluene into metabolic intermediates probably by breaking the aromatic ring upon fumarate addition. Subsequently, fermentative bacteria converted these intermediates into volatile fatty acids (VFA) and likely also H2, which were then used as substrates by electroactive microorganisms forming the anodic biofilm. As toluene degradation is faster than subsequent conversion steps, the increase in intermediate concentration could not result in a current increase. This work provides valuable insights on the syntrophic degradation of BTEX, which are essential for the application of microbial electrochemical system to groundwater remediation of petroleum hydrocarbons

    Chapter 16 - Cross-cutting investment and finance issues

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    This is the first time an assessment report by the Intergovernmental Panel on Climate Change (IPCC) contains a chapter dedicated to investment and finance to address climate change. This reflects the growing awareness of the relevance of these issues for the design of efficient and effective climate policies

    Unexpected combination of acute croup and myocarditis: Case report

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    BACKGROUND: Lower vaccination coverage among foreign-born children is of concern because they live in households and communities characterized by more intense exposure to infectious diseases. Because of their higher prevalence rates, there is an increasing occurrence of infectious diseases imported into developed countries. This case report emphasizes the emerging necessity for new clinicians and pathologists of having competence with old infectious disease pathology. CASE PRESENTATION: A three and a half year old girl, who presented with croup history of 5 days and has been in severe respiratory distress, was admitted to the Pediatric Intensive Care Unit in shock and acute respiratory failure. The patient was immediately intubated, and a grayish nonadherent membrane extending through the glottis down into the larynx was apparent during the procedure. Echocardiographic findings, which were consistent with acute myocarditis, confirmed poor left ventricular contractility despite escalating high doses of inotropes. Autopsy showed numerous strains of toxigenic corynobacterium diphtheriae, which also grew on the Loeffler cultures of membranes received during the intubation. CONCLUSION: It is critical that new generations of clinicians and bio-pathologists not only be trained in the subspecialty of infectious disease pathology, but that they also be willing participants in the diagnosis and investigation of infectious diseases

    Casting for a sovereign role:Socialising an aspirant state in the Scottish independence referendum

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    This article examines international reactions to Scotland’s 2014 bid for independence as an instance of socialisation of an aspirant state, what we term ‘pre-socialisation’. Building on and contributing to research on state socialisation and role theory, this study proposes a nexus between roles and sovereignty. This nexus has three components: sovereignty itself is a role casted for by an actor; the sovereign role is entangled with the substantive foreign policy roles the actor might play; and the sovereign role implicates the substantive foreign policy roles of other actors. The Scottish debate on independence provides an effective laboratory to develop and explore these theoretical dimensions of pre-socialisation, revealing the contested value and meaning of sovereignty, the possible roles that an independent Scotland could play, and the projected implications for the role of the UK and other international actors. Our analysis of the Scottish case can provide insights for other cases of pre-socialisation and is more empirically significant following the UK’s 2016 referendum to leave the European Union.PostprintPeer reviewe

    Long-term performance of a plant microbial fuel cell with Spartina anglica

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    The plant microbial fuel cell is a sustainable and renewable way of electricity production. The plant is integrated in the anode of the microbial fuel cell which consists of a bed of graphite granules. In the anode, organic compounds deposited by plant roots are oxidized by electrochemically active bacteria. In this research, salt marsh species Spartina anglica generated current for up to 119 days in a plant microbial fuel cell. Maximum power production was 100 mW m−2 geometric anode area, highest reported power output for a plant microbial fuel cell. Cathode overpotential was the main potential loss in the period of oxygen reduction due to slow oxygen reduction kinetics at the cathode. Ferricyanide reduction improved the kinetics at the cathode and increased current generation with a maximum of 254%. In the period of ferricyanide reduction, the main potential loss was transport loss. This research shows potential application of microbial fuel cell technology in salt marshes for bio-energy production with the plant microbial fuel cell

    High-Capacity Conductive Nanocellulose Paper Sheets for Electrochemically Controlled Extraction of DNA Oligomers

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    Highly porous polypyrrole (PPy)-nanocellulose paper sheets have been evaluated as inexpensive and disposable electrochemically controlled three-dimensional solid phase extraction materials. The composites, which had a total anion exchange capacity of about 1.1 mol kg−1, were used for extraction and subsequent release of negatively charged fluorophore tagged DNA oligomers via galvanostatic oxidation and reduction of a 30–50 nm conformal PPy layer on the cellulose substrate. The ion exchange capacity, which was, at least, two orders of magnitude higher than those previously reached in electrochemically controlled extraction, originated from the high surface area (i.e. 80 m2 g−1) of the porous composites and the thin PPy layer which ensured excellent access to the ion exchange material. This enabled the extractions to be carried out faster and with better control of the PPy charge than with previously employed approaches. Experiments in equimolar mixtures of (dT)6, (dT)20, and (dT)40 DNA oligomers showed that all oligomers could be extracted, and that the smallest oligomer was preferentially released with an efficiency of up to 40% during the reduction of the PPy layer. These results indicate that the present material is very promising for the development of inexpensive and efficient electrochemically controlled ion-exchange membranes for batch-wise extraction of biomolecules

    Quality of life after sleeve gastrectomy and adjustable gastric banding

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    Abstract Background: With the addition of laparoscopic vertical sleeve gastrectomy (SG) to the bariatric surgery procedural toolkit, patients desiring a restrictive bariatric procedure often choose between adjustable gastric banding (LAGB) and SG. One study compared quality of life after these 2 procedures and found no difference. The purpose of our study was to re-evaluate the postoperative quality of life in LAGB and SG patients at a military teaching hospital in the United States. Methods: A retrospective review of 108 consecutive laparoscopic restrictive bariatric procedures performed within 15 months at a Department of Defense hospital was conducted. Of these 108 patients, 69 had undergone laparoscopic vertical SG and 39 LAGB. A validated quality of life questionnaire (Bariatric Quality of Life) was conducted a mean of 9.3 Ï® 3.2 months (range 5-16) postoperatively. The weight loss and standard laboratory parameters were measured at 0, 1, 3, 6, and 12 months. Results: The quality of life assessment revealed significantly better scores after SG than after LAGB (66.5 versus 57.9, P Ï­ .0002). The excess weight loss and excess body mass index loss at 3, 6, and 12 months postoperatively were significantly greater in the laparoscopic SG group. The patients demonstrated a clear preference over time for SG once it was offered. Conclusion: Early postoperative quality of life was superior after SG than after LAGB. SG also resulted in superior early excess weight loss. In a practice not constrained by reimbursement, these findings were associated with increased patient choice of SG after it began to be offered. (Surg Obes Relat Dis 2012;8:31-40.

    Pharmacokinetic-Pharmacodynamic Modeling in Pediatric Drug Development, and the Importance of Standardized Scaling of Clearance.

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    Pharmacokinetic/pharmacodynamic (PKPD) modeling is important in the design and conduct of clinical pharmacology research in children. During drug development, PKPD modeling and simulation should underpin rational trial design and facilitate extrapolation to investigate efficacy and safety. The application of PKPD modeling to optimize dosing recommendations and therapeutic drug monitoring is also increasing, and PKPD model-based dose individualization will become a core feature of personalized medicine. Following extensive progress on pediatric PK modeling, a greater emphasis now needs to be placed on PD modeling to understand age-related changes in drug effects. This paper discusses the principles of PKPD modeling in the context of pediatric drug development, summarizing how important PK parameters, such as clearance (CL), are scaled with size and age, and highlights a standardized method for CL scaling in children. One standard scaling method would facilitate comparison of PK parameters across multiple studies, thus increasing the utility of existing PK models and facilitating optimal design of new studies
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