1,034 research outputs found

    Prognosis of subglottic carcinoma: Is it really worse?

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    Coskun, H., Mendenhall, W.M., Rinaldo, A., Rodrigo, J.P., Suárez, C., Strojan, P., López, F., Mondin, V., Saba, N.F., Shaha, A.R., Smee, R., Takes, R.P., Ferlito, A

    Using Reduced Kinetic Model for the Multi-Objective Optimization of Thermal Section of the Claus Process Leading to a More Cost-Effective and Environmentally Friendly Operation

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    The Claus process is a sulfur recovery unit wherein hydrogen sulfide is converted into the elemental sulfur. This study aims to model the thermal section of the Claus process, which consists of a reaction furnace and a waste heat boiler, as a configuration of two reactors, and subsequently optimize the entire section. Two different reduced kinetic schemes were provided for both units. Using the validated kinetics, mathematical models were developed. The waste heat boiler was modeled as a plug flow reactor with heat transfer, instead of a heat exchanger. The main objective was to maximize the amount of elemental sulfur at the end of the thermal section. Additionally, maximizing the amount of steam generated in the WHB was considered as a secondary objective, and the multi-objective optimization problem was solved. The sulfur production was improved 14.1% and 30% as a result of single- and multi-objective optimization studies. In addition, as an alternative, the Taguchi method was also used for optimization studies, and optimum values were determined. Using the Taguchi method, we determined that an increase in sulfur production by 24% is possible

    Extracorporeal life support in pediatric patients with congenital heart diseases: outcome of a single centre

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    Aim. In pediatric patients with congenital heart disease low cardiac output (LCO) is the principal complication after corrective heart surgery. In LCO refractory to all therapeutic options, mechanical circulatory support is the final method to keep these patients alive. In this present study the authors reviewed the outcome of pediatric patients who required mechanical circulatory support after corrective surgery with extracorporeal membrane oxygenation or ventricle assisted devices (VAD). Methods. A retrospective single centre consecutive cohort study was carried out in children who required different mechanical circulatory support indicated by postcardiotomy low output syndrome between 1991 and 2004. A total of 20 patients received extracorporeal life support. The indications for surgery were: 12 transposition of great arteries, 1 Bland-White-Garland syndrome, 3 tetralogy of Fallot, 1 hypoplasia of aortic arch, 1 total anomalous pulmonary vein connection, and 2 ventricle septum defect. Results. Mean age was 1.29 years. Mean duration of assist was 8.87 days. Seven patients out of 20 survived, six could be discharged after myocardial recovery from LCO and one could be discharged after successful heart transplantation. The overall mortality in patients with extracorporeal life support was 65%. The causes of death were multiorgan failure and bleeding in one case was a VAD related complication. Conclusion. The use of extracorporeal life support (ECLS) shows a high mortality rate. However, ECLS can still help to keep some of those patients alive. Mechanical support devices are the ultimate chance to save time, to increase survival and to bridge the time until heart transplantation

    Extracorporeal life support in pediatric patients with congenital heart diseases: outcome of a single centre

    No full text
    Aim. In pediatric patients with congenital heart disease low cardiac output (LCO) is the principal complication after corrective heart surgery. In LCO refractory to all therapeutic options, mechanical circulatory support is the final method to keep these patients alive. In this present study the authors reviewed the outcome of pediatric patients who required mechanical circulatory support after corrective surgery with extracorporeal membrane oxygenation or ventricle assisted devices (VAD). Methods. A retrospective single centre consecutive cohort study was carried out in children who required different mechanical circulatory support indicated by postcardiotomy low output syndrome between 1991 and 2004. A total of 20 patients received extracorporeal life support. The indications for surgery were: 12 transposition of great arteries, 1 Bland-White-Garland syndrome, 3 tetralogy of Fallot, 1 hypoplasia of aortic arch, 1 total anomalous pulmonary vein connection, and 2 ventricle septum defect. Results. Mean age was 1.29 years. Mean duration of assist was 8.87 days. Seven patients out of 20 survived, six could be discharged after myocardial recovery from LCO and one could be discharged after successful heart transplantation. The overall mortality in patients with extracorporeal life support was 65%. The causes of death were multiorgan failure and bleeding in one case was a VAD related complication. Conclusion. The use of extracorporeal life support (ECLS) shows a high mortality rate. However, ECLS can still help to keep some of those patients alive. Mechanical support devices are the ultimate chance to save time, to increase survival and to bridge the time until heart transplantation

    Author Correction: Inceptor counteracts insulin signalling in β-cells to control glycaemia.

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    In this Article, the affiliations for author Ünal Coskun were incorrect. They should be ‘German Center for Diabetes Research (DZD), Neuherberg, Germany’, ‘Paul Langerhans Institute Dresden of Helmholtz Center Munich, Technical University Dresden, Dresden, Germany’ and ‘Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Clinic Carl Gustav Carus, Technical University Dresden, Dresden, Germany’ (affiliations 2, 10 and 14, respectively), and not ‘Department of Microsystems Engineering (IMTEK), University of Freiburg, Freiburg, Germany’ (affiliation 5). The original Article has been corrected online

    Ten Theses on Logic Languages for the Semantic Web

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    This articles discusses the logic, or logic-based, languages required for a full deployment of the SemanticWeb. It presents ten theses addressing 1. the kinds of logic languages needed, 2. data and data processing, 3. semantics, and 4. engineering and rendering issues. The views reported about in this article have been presented at the W3C Workshop on Rule Languages for Interoperability (27-28 April 2005,Washington, D.C., USA, http://www.w3.org/2004/12/rules-ws/)

    Undergraduate psychiatric education: Current situation and way forward

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    Undergraduate psychiatric education is essential for the training of medical students and for their recruitment into psychiatry. A significant shortage of graduates choosing a career in psychiatry has been recently documented, and this trend might have many causes. When medical students have positive experiences of teaching, elective placements and exposure to psychiatric patients, their attitudes towards psychiatry are significantly better. Therefore, there is a need to improve the quality of undergraduate training courses in psychiatry. Innovative teaching strategies are suggested, including the use of movies, virtual reality, simulated patients and multiprofessional training wards

    A Light-Gated STOP-GO Molecular Shuttle

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    Degenerate [2]rotaxanes, with their two identical binding sites, generally exhibit equilibrium dynamics with free energies of activation (Delta G(double dagger)) for the shuttling process starting as low as 10 kcal.mol(-1). This Delta G(double dagger) value can be raised quite dramatically by inserting "speed bumps" in the form of steric and/or electrostatic barriers into the linkers between the two identical binding sites. In our more recent research targeted toward the exploitation of the 4,4'-azobiphenyloxy unit (ABP) as a light-operated gate, we decided to introduce (i) four methyl groups on the one hand and (ii) four fluorine atoms on the other, at the 3,5,3',5'-positions of the ABP units to curtail binding by the CBPQT(4+) ring if not sterically in the case of i, then electronically in the case of ii. The first approach led to a gate (ABP-Me(4)) that remains closed all the time, whereas the second approach affords a gate (ABP-F(4)) that we can close with UV light and open with visible light. Herein, we show how light can be used, in conjunction with thermal energy, to raise and tower the free energy barrier at will and, in so doing, impart STOP and GO instructions upon the operation of a molecular shuttle

    Training the trainers: Finding new educational opportunities in the virtual world

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    The COVID-19 pandemic has disrupted scientific gatherings and conferences, opening up opportunities for virtual learning platforms. Realizing the potential of online academic exchanges, the World Psychiatric Association (WPA) also developed virtual avenues and information systems for capacity building of mental health professionals across the world. Among its first such initiatives, the WPA organized a virtual Train the Trainers workshop, where 123 psychiatrists, psychiatric trainees, and educators from 45 countries participated. The innovative and interactive workshop allowed participants to get to know each other, exchange educational and professional experiences, and ask questions or receive advice from experts. Keynote speakers, including WPA President Prof. Afzal Javed and Prof. Norman Sartorius, stressed upon the importance of finding innovative solutions in psychiatry training and the need to improve teaching and training in the field of psychiatry, especially in the provision of leadership and communication skills. Online training methods can provide easy access to academics and students while reducing the organizational and logistical costs. They have the potential to improve educational equality and allow the voice of the underprivileged scientists to be heard across the globe. The devastating impact on access to mental health services during COVID-19 underscores the urgent need for online training, particularly in countries where the ratio of psychiatrists to patients is inadequate and doctors concentrate more on treatment than on research and education. Virtual educational interventions could prove incredibly useful in the future just as they are being successfully utilized in local and regional contexts during the pandemic
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