Toward detection of electron-hole pair excitation in H-atom collisions with Au(111): Adiabatic molecular dynamics with a semi-empirical full-dimensional potential energy surface.

We report an analytic potential energy surface (PES) based on several hundred DFT energies for H interacting with a Au(111) surface. Effective medium theory is used to fit the DFT data, which were obtained for the Au atoms held at their equilibrium positions. This procedure also provides an adequate treatment of the PES for displacements of Au atoms that occur during scattering of H atoms. The fitted PES is compared to DFT energies obtained from ab initio molecular dynamics trajectories. We present molecular dynamics simulations of energy and angle resolved scattering probabilities at five incidence angles at an incidence energy, Ei = 5 eV, and at a surface temperature, TS = 10 K. Simple single bounce trajectories are important at all incidence conditions explored here. Double bounce events also make up a significant fraction of the scattering. A qualitative analysis of the double-bounce events reveals that most occur as collisions of an H-atom with two neighboring surface gold atoms. The energy losses observed are consistent with a simple binary collision model, transferring typically less than 150 meV to the solid per bounce

O Profmat E A Formação Do Professor De Matemática: Uma Análise Curricular A Partir De Uma Perspectiva Processual E Descentralizadora

This paper analyzes the PROFMAT curriculum from the procedural and decentralized perspective of Sacristán (1998, 2013), adopting as references researches which aim was to study the teacher's knowledge needed to teach mathematics in basic school. Therefore, we analyzed: the academic project of this course; textbooks belonging to "PROFMAT Collection" used in the disciplines; data from classroom observation, the national schedule of disciplines; questionnaires answered by academics; and classroom assessments. From the analysis we conclude that there is no close connection between the elements that make up the PROFMAT curriculum and its intended goals, since these goals are not consubstantiated in the teaching material used in the classes, or in the curriculum modeling process by teachers and its development in the classroom, nor in the curriculum "accomplished" and "evaluated" especially because PROFMAT curriculum phases are not directly related to the math teacher of basic education practice.305690692

Charge-based continuous model for long-channel Symmetric Double-Gate Junctionless Transistors

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Noninvasive Assessment of Hemodynamic Stress Distribution after Indirect Revascularization for Pediatric Moyamoya Vasculopathy

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Prevalence, risk factors and outcomes of patients coming from the community with sepsis due to multidrug resistant bacteria

Background: Although previous studies showed an increasing prevalence of infections due to multi-drug resistant (MDR) bacteria in the community, specific data on sepsis are lacking. We aimed to assess prevalence, risk factors and outcomes of patients with sepsis due to MDR bacteria. Methods: An observational, retrospective study was conducted on consecutive adult patients coming from the community and admitted to the Policlinico Hospital, Milan, Italy, with a diagnosis of sepsis between January 2011 and December 2015. Primary study outcome was in-hospital mortality. Results: Among 518 patients, at least one MDR bacteria was isolated in 88 (17%). ESBL+ Enterobacteriaceae were the most prevalent MDR bacteria (9.7%) followed by MRSA (3.9%). Independent risk factors for sepsis due to MDR bacteria were septic shock (OR: 2.2; p = 0.002) and hospitalization in the previous 90 days (OR: 2.3; p = 0.003). Independent risk factors for sepsis due to ESBL+ bacteria were hospitalization in the previous 90 days (OR: 2.1; p = 0.02) and stroke (OR: 2.1; p = 0.04). A significantly higher mortality was detected among patients with vs. without MDR bacteria (40.2% vs. 23.1% respectively, p = 0.001). Independent risk factors for mortality among patients with sepsis were coagulation dysfunction (OR: 3.2; p = 0.03), septic shock (OR: 3.2; p = 0.003), and isolation of a MDR bacteria (OR: 4.6; p < 0.001). Conclusion: In light of the prevalence and impact of MDR bacteria causing sepsis in patients coming from the community, physicians should consider ESBL coverage when starting an empiric antibiotic therapy in patients with specific risk factors, especially in the presence of septic shock

Determination of Lightning Currents from Far Electromagnetic Fields: Effect of a Strike Object

We discuss in this paper the influence of the presence of an elevated strike object on the peak of the lightning return stroke current determined from remote field measurements. We develop analytical expressions relating the lightning return stroke channel-base current and the far electromagnetic field for different specific cases, namely, (1) ground-initiated return strokes (classical transmission line (TL) model), (2) ground-initiated return strokes including possible reflections at ground level, (3) tall strike objects for which the current's zero-to-peak time is smaller than the travel time along the object, and (4) electrically short strike objects. It is shown that for tall structures, the field enhancement relative to a return stroke initiated at ground level is expressed through a factor equal to ktall = [1 + c / v (1 - 2 ρt)] / (1 - ρt), where v and c are the return stroke front speed and the speed of light in vacuum, respectively, and ρt is the top reflection coefficient. For very short towers and/or very slow return stroke current wavefronts, when the condition tf very much greater than h / c applies, expressions relating the far electromagnetic field and the return stroke current were also derived. For case (2), return strokes initiated at ground level, the field enhancement relative to a return stroke initiated at ground level, case (1), is expressed through a factor equal to kshort = (1 + (c / v) ρch - g) / (1 + ρch - g), where ρch-g represents the reflection coefficient between the lightning channel and the grounding impedance

Low temperature scattering with the R-matrix method: the Morse potential

Experiments are starting to probe collisions and chemical reactions between atoms and molecules at ultra-low temperatures. We have developed a new theoretical procedure for studying these collisions using the R-matrix method. Here this method is tested for the atom -- atom collisions described by a Morse potential. Analytic solutions for continuum states of the Morse potential are derived and compared with numerical results computed using an R-matrix method where the inner region wavefunctions are obtained using a standard nuclear motion algorithm. Results are given for eigenphases and scattering lengths. Excellent agreement is obtained in all cases. Progress in developing a general procedure for treating ultra-low energy reactive and non-reactive collisions is discussed.Comment: 18 pages, 6 figures, 3 tables, conferenc

A PROBLEMÁTICA DO MONITORAMENTO DAS INFECÇÕES DE SÍTIO CIRÚRGICO E A NECESSIDADE DE PADRONIZAÇÃO DE CRITÉRIOS PARA SEU DIAGNÓSTICO E NOTIFICAÇÃO.

Las infecciones hospitalarias (IH) ocurren como un problema de salud pública mundial, siendo la Infección del Sitio Quirúrgico la tercera topografia más común, de 14% a 16% de todas las IH. Cuando un paciente muere por una causa asociada a la IH, 77% están relacionadas con la ISC; 93% de ellas con infecciones serias que invaden órganos o espacios accedidos durante un procedimiento quirúrgico. Directamente, las repercusiones de las ISC aparecen en los costos hospitalarios, pues aumentan la permanencia hospitalaria entre 7 a 10 días, amén de las readmisiones; pero, de manera indirecta, igualmente o más importante, están los costos indirectos que causan impactos emocionales desastrosos en los pacientes y en la familia. Los criterios más utilizados para diagnóstico de ISC son los Centers for Diseases Control (CDC); otros criterios desarrollados por especialistas ingleses como el National Prevalence Survey Study (NPS) también son utilizados. El objetivo de este estudio fue buscar una respuesta, en la literatura, para la práctica del controlador de infección hospitalaria en lo que respecta a la existencia de un “patrón-oro” para el diagnóstico de ISC, con el fin de soportar los resultados obtenidos y las consecuentes acciones. Una revisión sistemática ha mostrado que comparándose las definiciones del CDC y NPS de 93 heridas operatorias, 24% han quedado sin diagnóstico al utilizarse criterios del CDC y 19% cuando se utilizaron criterios del NPS. La conclusión de este estudio es que no hay un “patrón-oro” para el diagnóstico de ISC, pues el juicio es subjetivo, y sujeto a variaciones de acuerdo con el observador. Es necesario que cada servicio de salud junto al grupo Comissão de Controle de Infeccção Hospitalar -CCIH (Comisión de Control de Infección Hospitalaria) asuma y reglamente, por medio de la mejor evidencia científica, cuáles son los mejores criterios para diagnóstico y notificación de ISC, cuál es el mejor método de trabajo para vigilancia después del alta, teniendo en cuenta la factibilidad y las necesidades locales.As infecções hospitalares (IH) surgem como um problema de saúde pública mundial sendo a Infecção de Sítio Cirúrgico (ISC) a terceira topografia mais comum, de 14% a 16% de todas as IH. Quando um paciente morre por causa associada à IH, 77% estão relacionadas a ISC; 93% deles com infecções sérias que invadem órgãos ou espaços acessados durante o procedimento cirúrgico. Diretamente, as repercussões das ISC aparecem nos custos hospitalares pois aumentam a permanência hospitalar entre 7 a 10 dias, além das readmissões; mas de forma indireta e tão ou mais importante, estão os custos indiretos que provocam impactos emocionais desastrosos nos pacientes e familiares. Os critérios mais utilizados para diagnóstico de ISC são os do Centers for Diseases Control (CDC), outros critérios desenvolvidos por especialistas ingleses como o National Prevalence Survey Study (NPS) também são utilizados. O objetivo deste estudo foi buscar resposta, na literatura, para a pratica do controlador de infecção hospitalar no que tange a existência de um padrão ouro para o diagnostico de ISC, a fim de respaldar os resultados obtidos e as conseqüentes ações. Uma revisão sistemática mostrou que se comparando as definições do CDC e NPS de 93 feridas operatórias, 24% ficaram sem diagnóstico quando usados critérios do CDC e 19% quando usados critérios do NPS. A conclusão deste estudo é que não há padrão ouro, no diagnóstico de ISC, pois o julgamento é subjetivo e sujeito a variações de acordo com o observador. É preciso que cada serviço de saúde, junto ao grupo da Comissão de Controle de Infecção Hospitalar (CCIH) assuma e normatize, por meio da melhor evidência científica, quais os melhores critérios para diagnóstico e notificação de ISC, qual o melhor método de trabalho para vigilância no pós-alta; levando em conta a factibilidade e as necessidades locais