bluuebunny/crossref_metadata_2025 huggingface dataset:
Occupational Infection by the Hepatitis B Virus: Risk and Prevention Measures
Authors: Lima Bruno Francisco Real de , Waffae Maria Cristina , Figueiredo Elizabeth Niglio de , Filipinni Rosangela , Luz Maria Claudia De Brito , Azzalis Ligia Ajaime , Junqueira Virginia Berlanga Campos , Fonseca Fernando Luiz Affonso , Chaves Loide Corina
Published: February 2016

Resumo Introdução: a infecção pelo vírus da hepatite B (VHB) é um dos problemas mais sérios de saúde pública, em virtude do número elevado de pessoas infectadas por este agente etiológico. Objetivos: verificar o conhecimento apresentado pela equipe de enfermagem sobre o modo de transmissão do vírus da hepatite B (VHB) e os decorrentes agravos à saúde humana; Identificar o conhecimento da equipe de enfermagem sobre as medidas de prevenção utilizadas para evitar as infecções ocupacionais por este vírus e investigar a situação de imunização contra o VHB dos componentes da equipe de enfermagem. Método: estudo quantitativo realizado em 2008. A amostra foi composta por 38 componentes da equipe de enfermagem de um Hospital Público de Ensino do ABC paulista e, para a coleta de dados utilizou-se um formulário. Resultados: a transmissão sexual foi referida pela maior parte (24,57%) das respostas dos componentes da equipe de enfermagem, como modo de transmissão do VHB. O uso de equipamentos de proteção individual (EPI) foi citado por 41,54% destes profissionais como medida de prevenção para evitar a transmissão do VHB. Apenas 2,63% dos participantes referiram desconhecer algum caso de colega que já foi vítima de acidente com materiais perfuro cortantes. Todos os participantes deste estudo são imunizados contra o VHB. Conclusão: os profissionais deste estudo estão preparados quanto à utilização das precauções padrão.
Group Actions to Promote Adolescents Health
Authors: Macedo Etiene Oliveira Silva de , Conceição Maria Inês Gandolfo
Published: February 2016

ResumoO estudo analisou artigos brasileiros sobre pesquisas nas unidades básicas de saúde, que utilizaram como metodologia atividades educativas em grupo com adolescentes, para conhecer as características principais dessas atividades nos serviços de atenção primária à saúde. Foram acessadas as bases Lilacs, Scielo e Adolec. Os artigos foram categorizados segundo os critérios: (1) artigos publicados em periódicos brasileiros sobre (2) intervenções grupais com adolescentes para a promoção de saúde (3) nas unidades básicas de saúde, (4) entre 2000-2010. Os textos foram analisados de acordo com os itens: profissionais envolvidos, características metodológicas, temas abordados nos grupos, periodicidade, número de participantes, idade, sexo, concepção de adolescência presente nos estudos e resultados apresentados pelos autores. Os resultados mostraram um maior número de ações baseadas em pesquisas epidemiológicas e no enfoque biomédico da adolescência. As ações descritas nessas publicações focavam intervenções grupais para a prevenção de comportamentos de risco em saúde sexual e reprodutiva, em detrimento da diversidade de fatores relacionados à saúde integral dos adolescentes.
Incidence and Characteristics of Insufficient Birth Weight Newborns from a Cohort of Neonates in a Public Regional Hospital of a Metropolitan Area
Authors: Costa Roberta S. , Caldevilla Daniel E. , Gallo Paulo Rogério , Sena Brena Figueiredo , Leone Claudio
Published: February 2016

ResumoIntrodução: o peso de nascimento é um indicador utilizado na avaliação do crescimento intrauterino (IU) além de um marcador de risco de morbimortalidade. Já existe um número elevado de pesquisas sobre recém-nascidos (RN) de baixo peso (BPN), enquanto os sobre RN de peso de nascimento insuficiente (PNI) são raros, inclusive quanto às suas relações com o crescimento IU adequado ou restrito. Objetivo: estimar a incidência de peso insuficiente entre os recém-nascidos a termo e a proporção de pequenos para a idade gestacional entre os mesmos, em uma clientela urbana do SUS. Método: estudo observacional, em maternidade pública, do hospital Regional de Cotia, da região metropolitana de São Paulo que atende o SUS. Avaliou-se o universo de nascimentos vivos no último trimestre de 2009, determinando-se a proporção de RNPNI e a adequação do seu peso, segundo sexo e idade gestacional. Resultados: a incidência de PNI foi semelhante à observada no Brasil nas duas últimas décadas, correspondendo a 1/4 do total de nascimentos. A proporção de RN PIG foi pequena, afetando apenas 4,2% dos RN de PNI. Em 90% destes RN não se identificou patologias que explicassem o PNI. A proporção de nascimentos de partos cesáreos (47,1%) entre os RN de PNI, bem como a diferença de idade gestacional que os mesmos apresentavam em relação aos RN de peso adequado, cerca de 4 dias, do ponto de vista de crescimento IU não justificariam a diferença na média de peso existente entre os dois grupos. Conclusão: a incidência de PNI foi elevada, mas apenas uma pequena proporção destes RN era PIG. Os dados indicam a necessidade de se continuar pesquisando acerca do PNI, inclusive para fornecer subsídios que possam contribuir para melhorar a política e os programas de assistência pré e peri-natal.
Potenciais evocados auditivos de longa latência na síndrome de Asperger: estudo de dois casos
Authors: Gução Ana Cláudia Bianco , Romero Ana Carla Leite , Valenti Vitor Engracia , Cardoso Ana Cláudia Vieira , Misquiatti Andréa Regina Nunes , Frizzo Ana Claúdia Figueiredo
Published: February 2016

Introdução: Os Potenciais Evocados Auditivos de Longa Latência avaliam o processamento auditivo central através da atividade neuroelétrica da via auditiva, analisando as atividades corticais envolvidas nas habilidades de discriminação, integração e atenção do cérebro. Indivíduos com Síndrome de Asperger apresentam alterações em tais habilidades, sendo importante a investigação desses potenciais nessa população. O objetivo do trabalho foi descrever os achados dos Potenciais Evocados Auditivos de Longa Latência de dois pacientes com Síndrome de Asperger. Método: Participaram do estudo dois pacientes com Síndrome de Asperger do sexo masculino, com idade de 7 e 12 anos, atendidos em um centro de estudos, isentos de alterações auditivas,detectadas por meio de anamnese, inspeção do conduto auditivo externo e avaliação audiológica. Foi aplicado o potencial evocado auditivo de longa latência e analisado os componentes P2, N2 e P3. Resultados: A latência dos componentes P2, N2 e P3 mostrou-se alongada nas duas orelhas nos dois pacientes. Quanto à amplitude, o componente P2 estava com valores reduzidosapenas para a orelha esquerda do paciente 1 e direita do paciente 2. O N2 estava com amplitude reduzida nas duas orelhas do paciente 1 e apenas na orelha direita do paciente 2, e o P3 apresentou diminuição de amplitude apenas na orelha direita nos dois pacientes. Conclusão: Pode-se concluir que há alteração no funcionamento da informação auditiva ao nível do córtex nas duas crianças com Síndrome de Asperger atendidas neste centro.
Estereofotografia de Moirè: uma alternativa para avaliação da escoliose na saúde de escolares
Authors: Silva Júlio Guilherme , Almeida Márcia Santos de , Costa Carolina Gomes da , Rocha Aline Fraga , Silva Priscila Moreira da , Silva Rodrigo Teixeira Gomes da , Mainenti Miriam Raquel Meira
Published: February 2016

A Estereofotografia de Moiré (EFM) é um método que através da assimetria das sombras formadas no dorso detecta escoliose. Poucos os estudos tem discutido o tempo de análise, interpretação e custo operacional desta técnica. Os objetivos deste trabalho foram analisar os aspectos operacionais da (EFM) em escolares e; verificar desvios posturais pela EFM nesse mesmo grupo. Neste estudo foram analisadas 58 meninos e através da EFM, foram avaliadas a presença de sombras (franjas) no dorso, onde cada assimetria corresponde cerca de 10º no ângulo de Cobb. As marcações do EFM foram utilizadas para determinar os possíveis desvios. Os dados interesse receberam tratamento estatístico descritivo nas variáveis massa corporal total, índice de massa corporal (IMC), estatura, escoliose, tempo médio de análise e diagnóstico e, uma avaliação do custo operacional do equipamento. Os sujeitos (9,91 ± 0,79 anos) apresentaram uma massa corporal total de 37,83 ± 10,45kg, estatura 1,42 ± 0,11m e o IMC de 18,53 ± 4,15 kg/m2. O tempo médio para análise foi de 3,25 ± 0,29min. Na amostra, 75% tiveram um desvio de até uma franja na região toracolombar o que indica uma escoliose menor que 10º. A EFM constituiu um método rápido e de baixo custo operacional podendo ser um instrumento importante no rastreamento de escoliose. Concluímos que a EFM de confirmou ser prático e de fácil manuseio que 94,6% dos sujeitos apresentaram escoliose. Os nossos dados sugerem que a é viável a inserção da EFM nos programas de saúde em escolares de detecção das escolioses.
Alimentação escolar: o que o desenho infantil revela
Authors: Assao Tatiana Yuri , Westphal Marcia Faria , Bógus Cláudia Maria , Lara Bruna Robba , Mancuso Ana Maria Cervato
Published: February 2016

Objetivo: Identificar as percepções das crianças do ensino fundamental de escola públicas do município de Guarulhos, São Paulo, sobre a alimentação escolar. Método: Trata-se de um estudo do tipo descritivo com abordagem qualitativa. Participaram 82 crianças de 4 escolas selecionadas por desenvolverem atividades educativas em alimentação e nutrição, dentre as 63 instituições. Para coleta dos dados optouse pela técnica do desenho e a entrevista com as crianças para sua interpretação do desenho. Foram apresentados 13 desenhos, aqueles representativos de conteúdos expressos por um dos grupos de crianças. As verbalizações das crianças descrevendo os desenhos foram gravadas e transcritas, e juntamente com o conteúdo resultante da análise do material gráfico, submetidos à análise de conteúdo. Resultados: De acordo com os desenhos das crianças e suas respectivas verbalizações, a alimentação escolar estava associada: aos alimentos, os que são ofertados, que estes saciam a fome e trata-se de um momento que proporciona prazer; ao ambiente, o destaque foi para a estrutura física em que eram realizadas as refeições e a organização da fila que se formavam para se servirem e nas relações, representando a alimentação como um momento de convivência, de conversar e socializar com os amigos. Considerações Finais: Para as crianças a alimentação escolar adquire uma representação que extrapola o ato da alimentação, é um momento que engloba a relação com os alimentos, o ambiente escolar e as relações com os pares. Desta forma, um dos desafios para os gestores e toda a comunidade envolvida, é incorporar essas dimensões que permeiam a alimentação e que foram apontados como fundamentais e parte integrante do cenário escolar.
What is and how can be explained pregnancy in adolescence
Authors: Queiroga Kallyne Rubyan Oliveira , Farias Maria do Carmo Andrade Duarte de , Casimiro Geofabio Sucupira , Nascimento Aissa Romina Silva do , Maia Paula Christianne Gomes Gouveia Souto , Abrantes Kennia Sibelly Marques de , Valenti Vitor Engrácia , Abreu Luiz Carlos de
Published: February 2016

ResumoIntrodução: O exercício da sexualidade de forma inconsequente pode gerar inúmeros conflitos e interferir nos planos futuros de cada adolescente, resultando em gravidez precoce, por exemplo. Objetivo: Descrever as ideias associadas à temática gravidez na adolescência. Método: Tratase de uma revisão sistemática com produção científica acerca da gravidez na adolescência divulgada em periódicos da área da saúde, no período 2006 a 2010. Tem abordagem quantitativa e qualitativa dos dados. A amostra analisada totalizou 20 artigos. O instrumento de coleta de dados foi um roteiro estruturado contendo questões objetivas e subjetivas. Os dados quantitativos foram apresentados em tabela, os subjetivos, em quadros, refletidos através da análise temática (Bardin). Resultados: Os achados revelam sentimentos negativos, dentre outros, associados à gravidez na adolescência e a sua ocorrência a fatores psicológicos e socioeconômicos. Discussões: A gravidez na adolescência pode ser vista como um período de busca da identidade, ocorrendo em virtude da rebeldia, muitas vezes vivenciada em relação a sua família e ao contexto histórico-social. Portanto, sua explicação é multifatorial. Conclusão: Este fenômeno pode ser algo vivenciado positivamente ou negativamente, de forma desejada ou indesejada, com apoio familiar ou não. Por isso, faz-se necessário uma visão holística do fato. Espera-se que este estudo elucide questões acerca da gravidez na adolescência e coopere para ações preventivas e educativas.
Respiratory muscle strength of Brazilian adolescents: obtained and predicted values
Authors: Furtado Priscilla Rique , Campos Tania Fernandes , Mendes Raquel Emanuele de França , Freitas Diana Amélia de , Chaves Gabriela Suéllen da Silva , Macêdo Thalita Medeiros Fernandes de , Mendonça Karla Morganna Pereira Pinto de
Published: February 2016

ResumoObjetivos: Comparar os valores encontrados para as pressões respiratórias máximas de uma amostra de adolescentes brasileiros com os valores preditos por Wilson et al e Domènech-Clar et al. Método: Foram avaliados 156 adolescentes (84 meninos) entre 12 e 17 anos. As pressões respiratórias máximas foram avaliadas por meio de um manovacuômetro digital com os adolescentes sentados e utilizando um clipe nasal. As avaliações das pressões inspiratória e expiratória máximas foram realizadas a partir do volume residual e da capacidade pulmonartotal, respectivamente. A comparação dos valores das pressões respiratórias máximas obtidos no atual estudo com os preditos pelas equações propostas por Wilson et al e Domènech-Clar et al, foi realizada pelo teste t de Student pareado. Para verificar a associação entre estes valores, foi utilizado o teste de correlação de Pearson. Resultados: A média da pressão inspiratória máxima foi de 74,66 ± 22,95 cm H2O e de 103,52 ± 25,67 cm H2O para meninas e meninos, respectivamente. A média da pressão expiratória máxima foi de 86,23 ± 25,92 cm H2O e de 120,08 ± 27,37 cm H2O para meninas e meninos, respectivamente. O svalores obtidos não diferiram e também não se correlacionaram significativamente com os preditos através das equações propostas por Wilson et al., e Domènech-Clar et al. Conclusões: As equações propostas por Wilson et al. e Domènech-Clar et al., não foram capazes de predizer os valores das pressões respiratórias máximas na população estudada, indicando a necessidade de se usar na prática clínica valores de referência advindos de uma população saudável de mesma etnia.
Feeding practices in the first year of life
Authors: Alleo Luciana Galve , Souza Sonia Buongermino de , Szarfarc Sophia Cornbluth
Published: February 2016

Introdução: A alimentação é especialmente importante no primeiro ano de vida quando ocorre o desmame progressivo e compete à alimentação complementar suprir as necessidades nutricionais da criança a fim de garantir o crescimento e desenvolvimento. Objetivo: Descrever a prática alimentar em crianças no primeiro ano de vida. Método: Estudo transversal, com aplicação de questionário sobre a prática alimentar da criança. A amostra foi constituída de 122 criançascom idade até 365 dias divididas em 2 grupos: com até 3 meses completos de idade (34 crianças) e o grupo 2 foi formado por 88 crianças de 4 a 12 meses. Resultados: Entre as crianças do grupo 1, apenas 35,29% estavam em aleitamento materno exclusivo porém 95,9% da população de estudo referiu ter sido amamentada e 55,68% das crianças do grupo 2 ainda tomam leite materno. Dentre os alimentos já introduzidos na alimentação das crianças do grupo 2, obtevese: 83% para frutas, 69% legumes, 52,27% caldo de carnes, 58% de carnes (bovina e frango), 76% caldo de feijão, 42% feijão, 59% arroz/macarrão, 78% batata, 22,72% gema de ovo,16% ovo inteiro e 61% pão e bolacha. Verificou-se ausência de referência a verduras entre 52,27% da população, 73,86% não introduziram peixe e 75% o fígado. Conclusão: As práticas alimentares das crianças que participaram do estudo incluem grande diversidade de alimentos, porém houve baixa proporção de aleitamento materno exclusivo, em consequência da introdução precoce da alimentação complementar. Foi verificado baixo consumo de alguns alimentos como verduras e fígado.
Glial and neuronal Semaphorin signaling instruct the development of a functional myotopic map for Drosophila walking
Authors: Syed Durafshan Sakeena , Gowda Swetha B.M. , Reddy O Venkateswara , Reichert Heinrich , VijayRaghavan K
Published: February 2016

Motoneurons developmentally acquire appropriate cellular architectures that ensure connections with postsynaptic muscles and presynaptic neurons. In Drosophila, leg motoneurons are organized as a myotopic map, where their dendritic domains represent the muscle field. Here, we investigate mechanisms underlying development of aspects of this myotopic map, required for walking. A behavioral screen identified roles for Semaphorins (Sema) and Plexins (Plex) in walking behavior. Deciphering this phenotype, we show that PlexA/Sema1a mediates motoneuron axon branching in ways that differ in the proximal femur and distal tibia, based on motoneuronal birth order. Importantly, we show a novel role for glia in positioning dendrites of specific motoneurons; PlexB/Sema2a is required for dendritic positioning of late-born motoneurons but not early-born motoneurons. These findings indicate that communication within motoneurons and between glia and motoneurons, mediated by the combined action of different Plexin/Semaphorin signaling systems, are required for the formation of a functional myotopic map.
Simulation of conventional bipolar logic technologies in 4H-SiC for harsh environment applications
Authors: Elgabra Hazem , Siddiqui Amna , Singh Shakti
Published: February 2016

Silicon carbide (SiC) is a wide bandgap semiconductor that is inherently capable of operation in unforgiving environments such as high temperatures and radiation. Currently, the control circuitry for SiC based power devices and sensors are silicon based, limiting the overall efficiency of the system in such environments. 4H-SiC integrated circuits, based on different conventional logic technologies, have been investigated in the past using different device structures, by various research groups. This paper presents a thorough investigation of conventional bipolar logic technologies in 4H-SiC simulated across a wide range of temperatures (300–773 K) and power supply voltages (7–17 V). Unlike previous studies, this paper evaluates different technologies using the same device structure in the simulation, to highlight the true merits of each logic technology. The stable performance of all the studied logic technologies in SiC validates the potential of 4H-SiC ICs in small scale logic applications.
The origin of the medial circumflex femoral artery: a meta-analysis and proposal of a new classification system
Authors: Tomaszewski Krzysztof A. , Henry Brandon M. , Vikse Jens , Roy Joyeeta , Pękala Przemysław A. , Svensen Maren , Guay Daniel L. , Saganiak Karolina , Walocha Jerzy A.
Published: February 2016

Background and Objectives.The medial circumflex femoral artery (MCFA) is a common branch of the deep femoral artery (DFA) responsible for supplying the femoral head and the greater trochanteric fossa. The prevalence rates of MCFA origin, its branching patterns and its distance to the mid-inguinal point (MIP) vary significantly throughout the literature. The aim of this study was to determine the true prevalence of these characteristics and to study their associated anatomical and clinical relevance.

Methods.A search of the major electronic databases Pubmed, EMBASE, Scopus, ScienceDirect, Web of Science, SciELO, BIOSIS, and CNKI was performed to identify all articles reporting data on the origin of the MCFA, its branching patterns and its distance to the MIP. No data or language restriction was set. Additionally, an extensive search of the references of all relevant articles was performed. All data on origin, branching and distance to MIP was extracted and pooled into a meta-analysis using MetaXL v2.0.

Results.A total of 38 (36 cadaveric and 2 imaging) studies (n= 4,351 lower limbs) were included into the meta-analysis. The pooled prevalence of the MCFA originating from the DFA was 64.6% (95% CI [58.0–71.5]), while the pooled prevalence of the MCFA originating from the CFA was 32.2% (95% CI [25.9–39.1]). The CFA-derived MCFA was found to originate as a single branch in 81.1% (95% CI [70.1–91.7]) of cases with a mean pooled distance of 50.14 mm (95% CI [42.50–57.78]) from the MIP.

Conclusion.The MCFA’s variability must be taken into account by surgeons, especially during orthopedic interventions in the region of the hip to prevent iatrogenic injury to the circulation of the femoral head. Based on our analysis, we present a new proposed classification system for origin of the MCFA.
Modeling the magnetospheric X‐ray emission from solar wind charge exchange with verification from XMM‐Newton observations
Authors: Whittaker Ian C. , Sembay Steve , Carter Jennifer A. , Read Andrew M. , Milan Steve E. , Palmroth Minna
Published: February 2016

An MHD‐based model of terrestrial solar wind charge exchange (SWCX) is created and compared to 19 case study observations in the 0.5–0.7 keV emission band taken from the European Photon Imaging Cameras on board XMM‐Newton. This model incorporates the Global Unified Magnetosphere‐Ionosphere Coupling Simulation‐4 MHD code and produces an X‐ray emission datacube from O7+ and O8+ emission lines around the Earth using in situ solar wind parameters as the model input. This study details the modeling process and shows that fixing the oxygen abundances to a constant value reduces the variance when comparing to the observations, at the cost of a small accuracy decrease in some cases. Using the ACE oxygen data returns a wide ranging accuracy, providing excellent correlation in a few cases and poor/anticorrelation in others. The sources of error for any user wishing to simulate terrestrial SWCX using an MHD model are described here and include mask position, hydrogen to oxygen ratio in the solar wind, and charge state abundances. A dawn‐dusk asymmetry is also found, similar to the results of empirical modeling. Using constant oxygen parameters, magnitudes approximately double that of the observed count rates are returned. A high accuracy is determined between the model and observations when comparing the count rate difference between enhanced SWCX and quiescent periods.
Seismic reflection imaging of the Juan de Fuca plate from ridge to trench: New constraints on the distribution of faulting and evolution of the crust prior to subduction
Authors: Han Shuoshuo , Carbotte Suzanne M. , Canales Juan Pablo , Nedimović Mladen R. , Carton Hélène , Gibson James C. , Horning Greg W.
Published: February 2016

We present prestack time‐migrated multichannel seismic images along two cross‐plate transects from the Juan de Fuca (JdF) Ridge to the Cascadia deformation front (DF) offshore Oregon and Washington from which we characterize crustal structure, distribution and extent of faults across the plate interior as the crust ages and near the DF in response to subduction bending. Within the plate interior, we observe numerous small offset faults in the sediment section beginning 50–70 km from the ridge axis with sparse fault plane reflections confined to the upper crust. Plate bending due to sediment loading and subduction initiates at ~120–150 km and ~65–80 km seaward of the DF, respectively, and is accompanied by increase in sediment fault offsets and enhancement of deeper fault plane reflectivity. Most bend faulting deformation occurs within 40 km from the DF; on the Oregon transect, bright fault plane reflections that extend through the crust and 6–7 km into the mantle are observed. If attributed to serpentinization, ~0.12–0.92 wt % water within the uppermost 6 km of the mantle is estimated. On the Washington transect, bending faults are confined to the sediment section and upper‐middle crust. The regional difference in subduction bend‐faulting and potential hydration of the JdF plate is inconsistent with the spatial distribution of intermediate‐depth intraslab seismicity at Cascadia. A series of distinctive, ridgeward dipping (20°–40°) lower crustal reflections are imaged in ~6–8 Ma crust along both transects and are interpreted as ductile shear zones formed within the ridge's accretionary zone in response to temporal variations in mantle upwelling, possibly associated with previously recognized plate reorganizations at 8.5 Ma and 5.9 Ma.
Atmospheric ionization by high‐fluence, hard‐spectrum solar proton events and their probable appearance in the ice core archive
Authors: Melott Adrian L. , Thomas Brian C. , Laird Claude M. , Neuenswander Ben , Atri Dimitra
Published: February 2016

Solar energetic particles ionize the atmosphere, leading to production of nitrogen oxides. It has been suggested that some such events are visible as layers of nitrate in ice cores, yielding archives of energetic, high‐fluence solar proton events (SPEs). This has been controversial, due to slowness of transport for these species down from the upper stratosphere; past numerical simulations based on an analytic calculation have shown very little ionization below the midstratosphere. These simulations suffer from deficiencies: they consider only soft SPEs and narrow energy ranges; spectral fits are poorly chosen; and with few exceptions secondary particles in air showers are ignored. Using improved simulations that follow development of the proton‐induced air shower, we find consistency with recent experiments showing substantial excess ionization down to 5 km. We compute nitrate available from the 23 February 1956 SPE, which had a high‐fluence, hard‐spectrum, and well‐resolved associated nitrate peak in a Greenland ice core. For the first time, we find that this event can account for ice core data with timely (~2 months) transport downward between 46 km and the surface, thus indicating an archive of high‐fluence, hard‐spectrum SPEs covering the last several millennia. We discuss interpretations of this result, as well as the lack of a clearly defined nitrate spike associated with the soft‐spectrum 3–4 August 1972 SPE. We suggest that hard‐spectrum SPEs, especially in the 6 months of polar winter, are detectable in ice cores and that more work needs to be done to investigate this.
Sensitivity of thin cirrus clouds in the tropical tropopause layer to ice crystal shape and radiative absorption
Authors: Russotto R. D. , Ackerman T. P. , Durran D. R.
Published: February 2016

Subvisible cirrus clouds in the tropical tropopause layer (TTL) play potentially important roles in Earth's radiation budget and in the transport of water into the stratosphere. Previous work on these clouds with 2‐D cloud‐resolving models has assumed that all ice crystals were spherical, producing too few crystals greater than 60 μm in length compared with observations. In this study, the System for Atmospheric Modeling cloud‐resolving model is modified in order to calculate the fall speeds, growth rates, and radiative absorption of nonspherical ice crystals. This extended model is used in simulations that aim to provide an upper bound on the effects of ice crystal shape on the time evolution of thin cirrus clouds and to identify the physical processes responsible for any such effects. Model runs assuming spheroidal crystals result in a higher center of cloud ice mass than in the control, spherical case, while the total mass of ice is little affected by the shape. Increasing the radiative heating results in less total cloud ice mass relative to the control case, an effect which is robust with more extreme perturbations to the absorption coefficients. This is due to higher temperatures reducing the relative humidity in the cloud and its environment, and greater entrainment of dry air due to dynamical changes. Comparisons of modeled ice crystal size distributions with recent airborne observations of TTL cirrus show that incorporating nonspherical shape has the potential to bring the model closer to observations.
Controls on and effects of armoring and vertical sorting in aeolian dune fields: A numerical simulation study
Authors: Gao Xin , Narteau Clément , Rozier Olivier
Published: February 2016

Unlike ripples, there are only few numerical studies on grain size segregation at the scale of dunes in aeolian environments. Here we use a cellular automaton model to analyze vertical sorting in granular mixtures under steady unidirectional flow conditions. We investigate the feedbacks between dune growth and the segregation mechanisms by varying the size of coarse grains and their proportion within the bed. We systematically observe the development of a horizontal layer of coarse grains at the top of which sorted bed forms may grow by amalgamation. The formation of such an armor layer controls the overall sediment transport and availability. The emergence of dunes and the transition from barchan to transverse dune fields depend only on the grain size distribution of the initial sediment layer. As confirmed by observation, this result indicates that armor layers should be present in most arid deserts, where they are likely to control dune morphodynamics.
Basic Principles of Inverse Problems for Optical Scientists
Authors: Anastasio Mark A. , Schoonover Robert W.
Published: February 2016

Modern optical imaging systems are complicated in nature and require solution of a mathematical inverse problem for image formation. In this article, we provide an overview of some basic concepts and mathematical descriptions of linear inverse problems. This includes a review of linear vector spaces, Hilbert spaces, and operators. The singular value decomposition (SVD) is reviewed as a tool to analyze imaging system models. Methods for finding solutions to the inverse problem for discrete systems are subsequently provided, as well as a specific example from differential phase contrast tomography.
Robust switched control based on strictly positive real systems and variable structure control techniques
Authors: Cardim Rodrigo , Teixeira Marcelo C. M. , Assunção Edvaldo , Ribeiro Jean M. S. , Covacic Márcio R. , Gaino Ruberlei
Published: February 2016

This paper is concerned with the design of variable structure controllers for uncertain switched linear plants. The proposed method is based on Lyapunov–Metzler inequalities and on properties of strictly positive real (SPR) systems, with the advantage that it can be applied in control of uncertain switched linear system. The first contribution shows that there exists a solution of the SPR synthesis for a class of linear uncertain switched systems using switched static output feedback, if and only if there exists a solution of this SPR synthesis with switched static state feedback. This result is a generalization of known conditions regarding this problem, for linear time‐invariant and known (without uncertainties) plants, and offers a possible procedure for output feedback SPR synthesis: first solve the state feedback SPR synthesis and then, using the obtained solution, find a solution for the output feedback SPR synthesis. Next are presented necessary and sufficient (sufficient) conditions for the SPR synthesis for a class of linear uncertain switched systems using switched static output feedback, for plants with the same number of inputs and outputs (with the number of outputs greater than the number of inputs). Two examples illustrate the effectiveness of the robust control system, including applications of the proposed methods, considering switched static state feedback and switched static output feedback, in the design of switching control strategies for active suspensions systems in road vehicles. Performance indices such as decay rate, guaranteed cost, and restriction in the norm of controller gains are considered in these designs. Copyright © 2016 John Wiley & Sons, Ltd.
Nanostructured Titanium for Maxillofacial Mini‐Implants
Authors: Semenova Irina P. , Klevtsov Gennady V. , Klevtsova Natal'ya A. , Dyakonov Grigory S. , Matchin Aleksandr A. , Valiev Ruslan Z.
Published: February 2016

This paper studies nanostructured commercially pure Ti (CP Ti) used in producing miniature implants for osteosynthesis in the cranio‐facial and mandibular areas. Ti Grade 4 rods are nanostructured by equal‐channel angular pressing via the Conform scheme (ECAP‐C) and subsequent drawing. Plate‐shaped items are designed and produced from nano‐Ti. The cross‐section of items is reduced, but their static and fatigue strength values are retained. Geometrical aspect and surface treatment of implants produced from nanostructured Ti materials are discussed.
Outputting Olfactory Bionic Electric Impulse by PANI/PTFE/PANI Sandwich Nanostructures and their Application as Flexible, Smelling Electronic Skin
Authors: Xue Xinyu , Fu Yongming , Wang Qiang , Xing Lili , Zhang Yan
Published: February 2016

A new flexible smelling electronic skin (e‐skin) has been realized from PANI(polyaniline)/PTFE(polytetrafluoroethylene)/PANI sandwich nano­structures basing on the triboelectrification/gas‐sensing coupling effect. The e‐skin can be driven by human motion/breath and efficiently convert mechanical vibration into electric impulse. And the output current/voltage is significantly dependent on the environmental atmosphere (volatile organic compounds in air), which can act as olfactory bionic electric impulse. Taking ethanol gas as an example, the detection limit of the e‐skin at room temperature is 30 ppm, and the response is up to 66.8 upon exposure to 210 ppm ethanol. Interestingly, the response of the e‐skin keeps stable with different dimensional sizes or under different strains/bending status. The working mechanism can be ascribed to the coupling of triboelectrification effect and surface reaction at the interfaces. Furthermore, an application of the flexible smelling e‐skin for visually identifying drunken driver without any external electricity power has been demonstrated. The results can open a possible new direction for the development of specialized‐function e‐skin and will further expand the scope for self‐powered nanosystems.
Programming Mechanical and Physicochemical Properties of 3D Hydrogel Cellular Microcultures via Direct Ink Writing
Authors: McCracken Joselle M. , Badea Adina , Kandel Mikhail E. , Gladman A. Sydney , Wetzel David J. , Popescu Gabriel , Lewis Jennifer A. , Nuzzo Ralph G.
Published: February 2016

3D hydrogel scaffolds are widely used in cellular microcultures and tissue engineering. Using direct ink writing, microperiodic poly(2‐hydroxyethyl‐methacrylate) (pHEMA) scaffolds are created that are then printed, cured, and modified by absorbing 30 kDa protein poly‐l‐lysine (PLL) to render them biocompliant in model NIH/3T3 fibroblast and MC3T3‐E1 preosteoblast cell cultures. Spatial light interference microscopy (SLIM) live cell imaging studies are carried out to quantify cellular motilities for each cell type, substrate, and surface treatment of interest. 3D scaffold mechanics is investigated using atomic force microscopy (AFM), while their absorption kinetics are determined by confocal fluorescence microscopy (CFM) for a series of hydrated hydrogel films prepared from prepolymers with different homopolymer‐to‐monomer (Mr) ratios. The observations reveal that the inks with higher Mr values yield relatively more open‐mesh gels due to a lower degree of entanglement. The biocompatibility of printed hydrogel scaffolds can be controlled by both PLL content and hydrogel mesh properties.
A Surface Plasmon Enhanced Near‐Infrared Nanophotodetector
Authors: Luo Lin‐Bao , Zou Yi‐Feng , Ge Cai‐Wang , Zheng Kun , Wang Dan‐Dan , Lu Rui , Zhang Teng‐Fei , Yu Yong‐Qiang , Guo Zhong‐Yi
Published: February 2016

In this work, we present a plasmonic near infrared light photodetector for the detection of 980 nm illumination. The plasmonic photodetector is fabricated by modifying single layer graphene (SLG)/InP Schottky junction diode with SiO2 encapsulated gold nanorods (SiO2@AuNR), which can confine the incident NIR light by inducing obvious localized surface plasmon resonance, according to theoretical simulation based on finite element method. This study shows that after decoration with plasmonic SiO2@AuNR, the device performance in terms of photocurrent and responsivity is considerably enhanced. In addition, the device exhibited a very fast respose rate which is able to monitor switching optical signals with a frequency as high as 1 MHz, suggesting a potential application for sensing high‐frequency optical signals. This study manifests that the present plasmonic NIR photodetector will have great potential in future optoelectronic devices application.
Size‐Dependent Structures and Optical Absorption of Boron‐Hyperdoped Silicon Nanocrystals
Authors: Ni Zhenyi , Pi Xiaodong , Zhou Shu , Nozaki Tomohiro , Grandidier Bruno , Yang Deren
Published: February 2016

Hyperdoping silicon nanocrystals (Si NCs) is emerging as an effective means to obtain novel properties such as localized surface plasmon resonance (LSPR) from Si. Here it is shown that the physical properties and in particular the LSPR of boron (B)‐hyperdoped Si NCs significantly change as the NC size decreases from 6.8 to 2.4 nm. While the largest Si NCs undergo a stronger reduction of the average lattice spacing upon doping with respect to the smallest ones, they suffer much less from disorder and show LSPR over a wider range of B concentration. As a result, by taking advantage of the tunability of the NC size and doping level, the LSPR energy can be changed, making attractive the development of novel Si structures and devices based on B‐hyperdoped Si NCs.
Highly Efficient All‐Solution‐Processed Low‐Voltage Organic Transistor with a Micrometer‐Thick Low‐k Polymer Gate Dielectric Layer
Authors: Tang Wei , Feng Linrun , Yu Pengfei , Zhao Jiaqing , Guo Xiaojun
Published: February 2016

The development of organic thin‐film transistors (OTFTs) towards commercial viability must overcome a critical hurdle: achieving low operation voltage and high power efficiency with a fully printable device structure. This work realizes all‐solution‐processed low‐voltage OTFTs on a micrometer‐thick (1.16 μm) gate dielectric layer of very common material (commercial SU8 photoresist) by reducing the sub‐gap density of states at the channel. Being operated with a similar low voltage but at a gate dielectric capacitance of orders‐of‐magnitude smaller than that of conventional low voltage OTFTs, the fabricated device presents the best reported power efficiency. Logic circuits using this OTFT are shown to be able to run faster but consume significantly less power. Moreover, since being operated at a record low gate field of 0.05 MV cm−1 attributed to the thick dielectric layer, the device also exhibits several other attractive features such as large gate input impedance and the capability of sustaining high voltage operation. This device design would be an ideal solution to address the material and process issues for developing fully‐printable low voltage OTFTs with desired performance for the envisioned applications.
A three‐dimensional geometric morphometrics view of the cranial shape variation and population history in the New World
Authors: Galland Manon , Friess Martin
Published: February 2016

Objectives

Craniofacial variation in past and present Amerindians has been attributed to the effect of multiple founder events, or to one major migration followed byin situdifferentiation and possibly recurrent contacts among Circum‐Arctic groups. Our study aims to: (i) detect morphological differences that may indicate several migrations; (ii) test for the presence of genetic isolation; and (iii) test the correlation between shape data and competing settlement hypotheses by taking into account geography, chronology, climate effects, the presence of genetic isolation and recurrent gene flow.

Methods

We analyzed a large sample of three‐dimensional (3D) cranial surface scans (803 specimens) including past and modern groups from America and Australasia. Shape variation was investigated using geometric morphometrics. Differential external gene flow was evaluated by applying genetic concepts to morphometric data (Relethford‐Blangero approach). Settlement hypotheses were tested using a matrix correlation approach (Mantel tests).

Results

Our results highlight the strong dichotomy between Circum‐Arctic and continental Amerindians as well as the impact of climate adaptation, and possibly recurrent gene flow in the Circum‐Arctic area. There is also evidence for the impact of genetic isolation on phenetic variation in Baja California. Several settlement hypotheses are correlated with our data.

Conclusions

The three approaches used in this study highlight the importance of local processes especially in Baja California, and caution against the use of overly simplistic models when searching for the number of migration events. The results stress the complexity of the settlement of the Americas as well as the mosaic nature of the processes involved in this process. Am. J. Hum. Biol. 28:646–661, 2016. © 2016 Wiley Periodicals, Inc.
Der Einfluss des nacnac‐Liganden in der Eisen(I)‐vermittelten P4‐Umwandlung
Authors: Spitzer Fabian , Graßl Christian , Balázs Gábor , Zolnhofer Eva M. , Meyer Karsten , Scheer Manfred
Published: February 2016

Eine Studie zur P4‐Umwandlung an niedervalenten Eisenkomplexen wird vorgestellt, bei der β‐Diketiminato(L)‐FeI‐Komplexe vom Typ [LFe(tol)] (tol=Toluol; L=L1 (1 a), L2 (1 b), L3 (1 c)) mit unterschiedlichen Kombinationen von aromatischen und Rückgrat‐Substituenten am Liganden genutzt werden. Die Produkte [(LFe)4(μ4‐η2:η2:η2:η2‐P8)] (L=L1 (2 a), L2 (2 b)), die ein P8‐Gerüst enthalten, werden durch die Reaktion von 1 a,b mit P4 in Toluol bei Raumtemperatur erhalten. Bei Verwendung eines etwas sperrigeren Liganden in 1 c wird [(L3Fe)2(μ‐η4:η4‐P4)] (2 c) gebildet, welches eine cyclo‐P4‐Einheit enthält. Die Verbindungen 2 a–c wurden umfassend charakterisiert und ihre elektronische Struktur durch SQUID‐Magnetisierung und 57Fe‐Mössbauer‐Spektroskopie sowie mittels DFT‐Methoden untersucht.
Total Synthesis of (−)‐Nakadomarin A
Authors: Clark J. Stephen , Xu Chao
Published: February 2016

A highly efficient 12‐step synthesis of the marine alkaloid (−)‐nakadomarin A has been accomplished. The key advanced intermediate, a tetracyclic ketone derivative, was constructed in just seven steps using a sequence that includes an asymmetric Pauson–Khand reaction, an Overman rearrangement reaction, a ring‐closing metathesis reaction, and an amination reaction. Late introduction of the furan ring during the synthesis of (−)‐nakadomarin A means that the key tetracyclic ketone derivative has the potential to serve as an advanced intermediate for the synthesis of related marine alkaloids.
An integrated numerical study of coextrusion flow inside and outside the die
Authors: Yang Chuan , Li Ziran
Published: February 2016

The three‐dimensional coextrusion flow of two polymer melts is solved over the die‐extrudate region using the finite element method. As elastic recovery is known to be the main source of extrudate swelling, a viscoelastic constitutive model (the Phan‐Thien‐Tanner or PTT model) is adopted to characterize the rheological behavior of the elastomers. A major challenge in the simulation of multilayer flow inside and outside the die is to update multiple moving surfaces (material interface and extrudate free surface) simultaneously. This difficulty is resolved by introducing a two‐step updating algorithm which decouples the iterations of the interface and the free surface. The effects of extrudate swelling and bending on interface deformation are investigated herein, together with the interface shape dependency on flow elasticity. The numerical method is also applied to an industrial profile and the simulation result is in quantitative agreement with the experimental coextrusion data. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43522.
Chemical Composition and Antimicrobial Activity of the Essential Oil and Methanol Extract of Hypericum aegypticum subsp. webbii (Spach) N. Robson
Authors: Marčetić Mirjana D. , Milenković Marina T. , Lakušić Dmitar V. , Lakušić Branislava S.
Published: February 2016

Hypericum aegypticum subsp. webbii is an evergreen shrub spread in Mediterranean part of central and southeastern Europe. The chemical composition and antimicrobial activity of the essential oil and MeOH extract of H. aegypticum subsp. webbii were investigated. The monoterpenes α‐pinene (63.4 – 68.5%) and β‐pinene (16.9 – 17.0%) were main compounds in the volatile oil from aerial parts. In the cluster analysis, the essential oil of H. aegypticum subsp. webbii was separated and chemically different from the oil of other subspecies of H. aegypticum as well as other Hypericum species from Greece. SIMPER analysis revealed that α‐pinene (24.79%) was the component that contributed the most to differences between all oils. Also, there was extremely high overall dissimilarity between three subspecies of H. aegypticum. MeOH extract of aerial parts of H. aegypticum subsp. webbii contained flavonoids rutin (56.4 ± 0.9 mg/g), hyperoside and quercetin, and phenolic acids chlorogenic and caffeic acid, while naphthodianthrones were not detected. The antimicrobial activity of essential oil was moderate (MIC from 100 to >200 μg/ml), while MeOH extract inhibited the growth of Gram‐positive bacteria Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, and Micrococcus luteus (MIC 50 – 100 μg/ml), more pronounced than the extract of H. perforatum (MIC 200 – >200 μg/ml).
Computational Fluid Dynamics Simulation of Multiscale Mixing in Anionic Polymerization Tubular Reactors
Authors: Xie Le , Zhu Li‐Tao , Luo Zheng‐Hong
Published: February 2016

The molecular properties of polymers are greatly influenced by operation parameters during polymerization in reactors. Since operation parameter distributions in reactors also result in molecular property distributions, polymerization bridges the gap between molecular properties and operation parameters. The combination of the computational fluid dynamics technology with the method of moments to form a uniquely coupled model was used to describe multiscale mixing fields in the reactor. The coupled model was validated by open experimental data, and the effects of polymerization kinetics on macroscopic and microscopic fields were investigated numerically. Also, the coupled model was applied to numerically predict the impacts of some key operation conditions on the main macroscopic flow field parameters and polymer molecular properties.
Solvent‐Aided Layer Crystallization of Glycerol – Post‐Treatment and the Influence of Agitation
Authors: Eisenbart Felix J. , Ulrich Joachim
Published: February 2016

The purification of glycerol from water by melt layer crystallization with an additional solvent to influence the crystallization kinetics is investigated. Static cold finger experiments including a sweating‐like post‐treatment were carried out. A simple seeding technique is introduced to facilitate layer crystallization without primary nucleation or agitation. It is shown that the glycerol crystal layers tend to burst in a traditional sweating procedure, but a modified temperature profile allows a post‐treatment with a similar effect. The solvent improved the separation efficiency of the growth step and also the one of the sweating step. Therefore, its effect does not only result from its influence on forced convection but also that on natural convection and diffusion.