742 research outputs found
A unified survey of Si-H and H-H bond activation catalysed by electron-deficient boranes
The bond activation chemistry of B(C6F5)(3) and related electron-deficient boranes is currently experiencing a renaissance due to the fascinating development of frustrated Lewis pairs (FLPs). B(C6F5)(3)'s ability to catalytically activate Si-H bonds through eta(1) coordination opened the door to several unique reduction processes. The ground-breaking finding that the same family of fully or partially fluorinated boron Lewis acids allows for the related H-H bond activation, either alone or as a component of an FLP, brought considerable momentum into the area of transition-metal-free hydrogenation and, likewise, hydrosilylation. This review comprehensively summarises synthetic methods involving borane-catalysed Si-H and H-H bond activation. Systems corresponding to an FLP-type situation are not covered. Aside from the broad manifold of C=X bond reductions and C=X/C-X defunctionalisations, dehydrogenative (oxidative) Si-H couplings are also included.DFG, EXC 314, Unifying Concepts in Catalysi
EFFECTS OF AN 8-WEEK KNEE INJURY PREVENTION PROGRAM AND TECHNIQUE MODIFICATION TRAINING ON CHANGE-OF-DIRECTION PERFORMANCE
The purpose of this analysis was to determine whether an 8-week knee injury prevention program with an additional focus on change-of-direction (COD) technique training results in improved COD performance compared to a control training group with a focus on linear sprint training. Although both groups showed indicators for superior performance during a 135-degree COD, such as a more effective reorientation of the body, the COD technique modification component was ineffective in improving overall COD completion time or ground contact times. Follow-up analyses will show whether the COD group adopted a safer COD movement strategy following training, e.g. by reducing the knee valgus loading
As time goes by - Overlooking 40 years of inpatient burn treatment at a national pediatric burn center in Switzerland
BACKGROUND
Despite extensive prevention programs, burns remain a frequent cause of injury in Switzerland with a known age peak in children. Pediatric burns may cause substantial morbidity, a psyochological burden and therapy related high economic costs. To improve preventive measures, precise knowledge of etiology and treatment of pediatric burns in Switzerland as well as their temporal evolution is indispensable.
METHODS
The present retrospective analysis included pediatric burn patients admitted for acute treatment to the Pediatric Burn Center of the University Children`s Hospital Zurich over the last four decades. Sociodemographic, injury related, and treatment related data were extracted from medical records. Linear regression analysis was applied to determine temporal changes during the past four decades and chi-square and t-tests were applied wherever applicable.
RESULTS
A total of 3425 acute burn patients were included in the study between 1977 and 2020, corresponding to a mean of 89 patients/year. Mean age was 3.60 ± 4.12 years, three quarters of all patients were preschool children (0-5 years) and mean total body surface area (TBSA) burned was 8.01% ± 9.57%, however only around one fifth had severe burns (>10% TBSA). Scald burns (65.31%) and flame burns (32.99%) were most commonly seen. Linear regression analysis showed the total number of thermal injuries treated at our center to have increased significantly as of 2004 (p < 0.001). Separate analysis showed the same for small and medium (<10% TBSA) burns (p < 0.001), whereas the number of severe burns did not increase significantly. Length of stay (LOS) was highly associated with %TBSA burned. The percentage of female patients amongst all patients increased over time (p = 0.012). LOS per TBSA burned decreased significantly (p < 0.001).
CONCLUSION
The present data show pediatric burns to remain a major health burden in Switzerland, especially small and medium burns in preschool children. Prevention programs should focus on this age population as well as on scald and flame burns as most common etiologies. The observed decrease in length of stay suggests a major improvement in overall quality of care in pediatric burns and supports centralization of care
Controlled Photographic Images for Visual Search Experiments with Quantified Contextual Priors
PERCEPÇÃO DOS GESTORES DAS EMPRESAS EM RELAÇÃO AO PROFISSIONAL CONTÁBIL: UM ESTUDO NAS MICRO E PEQUENAS EMPRESAS DA ATIVIDADE DE COMÉRCIO NO MUNICÍPIO DE PINHALZINHO – SC
Fetal-Maternal Surgery for Spina Bifida in a HIV-Infected Mother
Introduction: In select cases, in utero surgery for myelomeningocele (MMC) leads to better outcomes than postnatal repair. However, maternal HIV infection constitutes a formal exclusion criterion due to the potential of vertical HIV transmission. Encouraged by a previous case of a successful fetal spina bifida repair in a Hepatitis Bs antigen-positive woman, a plan was devised allowing for fetal surgery.
Case report: In utero MMC repair was performed although the mother was HIV-infected. To minimize the risk of in utero HIV transmission, the mother was treated by highly active antiretroviral therapy throughout gestation as well as intravenous zi-dovudine administration during maternal-fetal surgery. The mother tolerated all procedures very well without any sequelae. The currently 20 month-old toddler is HIV negative and has significantly benefitted from fetal surgery.
Discussion/conclusion: This case shows that maternal HIV is not a priori a diagnosis that excludes fetal surgery. Rather, it might be a surrogate for moving towards personalized medicine and away from applying too rigorous exclusion criteria in the selection of candidates for maternal-fetal surgery.
Keywords: HIV; Maternal-fetal surgery; Myelomeningocele; Post-exposure prophylaxis; Zidovudin
Development of a risk assessment tool for contact tracing people after contact with infectious patients while travelling by bus or other public ground transport: a Delphi consensus approach
Background: Tracing persons who have been in contact with an infectious patient may be very effective in preventing the spread of communicable diseases. However, criteria to decide when to conduct contact tracing are not well established. We have investigated the available evidence for contact tracing with a focus on public ground transport aiming to give guidance in what situations contact tracing should be considered. Methods: Relevant infectious diseases suitable for contact tracing in ground transport and a set of disease-specific epidemiological criteria were defined through literature search and structured multistep expert consultations. We developed continuous scales for each criterion to be rated for its relevance to contact tracing in ground transport. We used the Delphi method with an international expert panel to position the values of criteria on the respective scales. Results: The study led to the development of the ‘Contact Tracing-Risk Assessment Profile’ (CT-RAP), a decision-making instrument, taking into account pathogen-specific as well as situation-specific criteria. This report describes the methodology of this instrument and presents two examples of ready-to-use CT-RAP for tuberculosis and for meningococcal disease in public ground transport. Discussion: The systematic and transparent use of the CT-RAP for tuberculosis and meningococcal disease is likely to facilitate reasonable, efficient and user-friendly decisions with respect to contact tracing. New CT-RAPs for additional pathogens and different settings such as schools and kindergartens are being planned
PERCEPÇÃO DOS GESTORES DAS EMPRESAS EM RELAÇÃO AO PROFISSIONAL CONTÁBIL: UM ESTUDO NAS MICRO E PEQUENAS EMPRESAS DA ATIVIDADE DE COMÉRCIO NO MUNICÍPIO DE PINHALZINHO – SC.
Accounting was seen for a long time as a tax information system, but its function goes far beyond it, it represents a necessary tool for the management of entrepreneurs with accurate information that contributes to the decision-making process in an efficient way. The general objective of this research is to identify and understand the perception of managers of micro and small companies in the commercial activity of the municipality of Pinhalzinho in relation to the accounting professional. For data collection, a questionnaire consisting of 23 questions was used, applied to all micro and small companies in the commercial activity of the municipality of Pinhalzinho - SC. The research is framed by the descriptive method and the data were presented through qualitative analysis that aims to explore and understand the perceptions of the respondents. The results obtained indicate the evolution of the accounting professional in the way of providing services to companies. Its importance was significantly observed in companies, with the appreciation of the activities developed and the contribution of information in decision making.Keywords: Accounting professional. managers. Perception.A contabilidade foi vista durante muito tempo como um sistema de informações tributárias, mas sua função está muito além, ela representa uma ferramenta necessária para a gestão dos empresários com informações precisas que contribuem no processo de tomada de decisão de maneira eficiente. O objetivo geral desta pesquisa consiste em identificar e compreender a percepção dos gestores das micro e pequenas empresas da atividade de comércio do município de Pinhalzinho em relação ao profissional contábil. Para a coleta de dados, utilizou-se um questionário composto por 23 questões, aplicado a todas as micro e pequenas empresas da atividade de comércio do município de Pinhalzinho – SC. A pesquisa se enquadra pelo método descritivo e os dados foram apresentados por meio de análise qualitativa que visa explorar e entender as percepções dos respondentes. Os resultados obtidos indicam a evolução do profissional contábil na forma de prestar os serviços as empresas. Sua importância foi observada de modo significativo nas empresas, com a valorização das atividades desenvolvidas e a contribuição das informações na tomada de decisão.
Palavras-chave: Profissional contábil. Gestores. Percepção
Experimental Realisation of High-sensitivity Laboratory X-ray Grating-based Phase-contrast Computed Tomography
The possibility to perform high-sensitivity X-ray phase-contrast imaging with laboratory grating-based phase-contrast computed tomography (gbPC-CT) setups is of great interest for a broad range of high-resolution biomedical applications. However, achieving high sensitivity with laboratory gbPC-CT setups still poses a challenge because several factors such as the reduced flux, the polychromaticity of the spectrum, and the limited coherence of the X-ray source reduce the performance of laboratory gbPC-CT in comparison to gbPC-CT at synchrotron facilities. In this work, we present our laboratory X-ray Talbot-Lau interferometry setup operating at 40 kVp and describe how we achieve the high sensitivity yet unrivalled by any other laboratory X-ray phase-contrast technique. We provide the angular sensitivity expressed via the minimum resolvable refraction angle both in theory and experiment, and compare our data with other differential phase-contrast setups. Furthermore, we show that the good stability of our high-sensitivity setup allows for tomographic scans, by which even the electron density can be retrieved quantitatively as has been demonstrated in several preclinical studies
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