bluuebunny/crossref_metadata_2025 huggingface dataset:
Celebrações do saber: exames finais nas escolas da região colonial italiana, Rio Grande do Sul, 1875 a 1930
Authors: Luchese Terciane Ângela
Published: May 2014

Resultado de pesquisa institucional sobre o processo escolar entre imigrantes italianos e seus descendentes, este artigo apresenta uma análise dos momentos de exames finais como elemento importante para pensarmos as práticas educativas e avaliativas. A partir de indícios documentais diversificados, o recorte espacial abrange a chamada região colonial italiana do Rio Grande do Sul (antigas colônias Dona Isabel, Caxias e Conde d’Eu). A análise privilegia o período de 1875 a 1930 e o referencial teórico-metodológico utilizado foi o da História Cultural. No cumprimento do calendário escolar um dos principais momentos, ao final do ano letivo, era o dos exames finais. Estes se constituíam no momento ápice da avaliação escolar. Eram celebrados e em torno de sua realização havia um ritual de relações de poder evidenciado pelos diversos registros – fotográficos, atas, jornais que publicavam os resultados e todo o conjunto de atividades de permeavam o ritual dos exames. Quem compunha a comissão examinadora? Por quem eram nomeados? Como procediam na aplicação dos exames? Quais os conhecimentos exigidos/valorizados? Como os professores preparavam a turma para os exames finais? O que eles dimensionam das relações de poder, das culturas escolares? Premiações, almoços festivos, que outros momentos eram preparados após os exames? Estas e algumas outras questões são o cerne deste estudo produzido a partir de fontes historiográficas diversificadas como relatórios, mapas de freqüência, correspondências diversas, cadernos de chamada, atas, jornais e fotografias. O estudo procura contribuir para o conhecimento da história da educação brasileira, considerando a multiplicidade cultural e étnica da Região.
Narrativas e atividade docente: perspectivas e desafios metodológicos para a pesquisa em educação e formação de professores
Authors: De Lima Elieuza Aparecida , De Castro Rosane Michelli
Published: May 2014

Este texto emerge de nossos percursos de pesquisa e extensão universitárias, a partir de nossas preocupações com a formação inicial e continuada de professores da e para a Educação Infantil e os anos iniciais do Ensino Fundamental. Tivemos, como intenção central, apresentar aspectos de alguns desses encaminhamentos efetivados em busca da criação de possibilidades para a construção coletiva de condições para nutrir todos os envolvidos nos processos investigativos com um conjunto de saberes necessários à tomada de decisões e posicionamentos sobre a e na prática pedagógica. Da ótica teórico-metodológica que baseou nossas pesquisas, os processos formativos de professores devem ir ao encontro da expressão das suas ações práticas, a fim de se produzir um novo conhecimento relativizado, entendido com base nas circunstâncias, dos sujeitos e dos lugares sociais daqueles que o elaboram e o disseminam. Essa compreensão foi responsável pelas opções metodológicas feitas para a proposição e o desenvolvimento de nossas pesquisas, prioritariamente a História Oral. Finalmente, concluímos, dentre outros aspectos, que a singularidade do que é realizado, pensado e falado no mundo da escola e, portanto, a prática da pesquisa pedagógica pela via da narrativa é prenhe de conteúdo para projeção de novas ações em favor da melhoria dos processos de ensino e de aprendizagem dirigidos à formação e atuação docentes e à humanização plena de adultos e crianças.
Grupos de interlocução como técnica de produção e sistematização na pesquisa em educação
Authors: Soares Ferreira Liliana , Pereira Alves Fiorin Bruna , De Castro do Amara Cláudia Letícia , Severo Maraschin Mariglei
Published: May 2014

Este artigo discute a pesquisa em educação na atualidade, considerando o viés da perspectiva crítica de apreensão do real, e a utilização de grupos de interlocução como técnica apropriada a ela. Inclusa no campo educacional, a pesquisa formaliza-se, passa a ser uma ação pedagógica cujos objetivos revelam a intencionalidade da instituição e do pesquisador. O grupo de interlocução é apresentado como um momento de interação entre pesquisador e sujeitos da pesquisa a fim de socializar os resultados do estudo e discutir sobre estes dados e sobre questões que ainda necessitam ser ampliadas. Através da linguagem, cada um dos sujeitos da pesquisa apresenta suas concepções, influenciados por suas experiências, mas, a partir deste momento de diálogo e interação, terão a possibilidade de socializar e problematizar o tema pesquisado com sujeitos que, possivelmente, tem algo comum entre si devido a sua proximidade com a pesquisa desenvolvida. Considera-se que o grupo de interlocução é mais do que uma coleta, apresentação ou quantificação de dados, é um momento de problematização conjunta acerca da pesquisa.
Estilos de fé e sentido da vida
Authors: Avellar de Aquino Thiago Antonio , Cabral Dantas Cintya Thaiana Araújo , Felinto Medeiros Ianny , Moraes Imytissonara Oliveira A. Leôncio de , Melo Myriam De Oliveira , Nascimento Najara Mirella Cordeiro do , O. Andrade Samkya Fernandes de , Do Socorro Abrantes Maria , Nunes Pires Vânia
Published: May 2014

O presente trabalho teve como objetivo identificar os estilos de fé e relacioná-los com os níveis de religiosidade e vazio existencial. Para tanto, utilizou-se como principal referencial teórico a análise existencial de Viktor Frankl, que compreende a religiosidade como uma vontade de sentido último para a vida. A amostra foi constituída por 25 pessoas com idade média de 31 anos. Os instrumentos utilizados foram o Teste Propósito de Vida (PIL-Test), de James C. Crumbauch e Leonard T. Maholick, um questionário de atitude religiosa e seis perguntas da entrevista sobre o desenvolvimento da fé, originalmente elaborada por James W. Fowler. Por meio de análise de conteúdo foi possível identificar categorias pertinentes as concepções de Deus; o que faz a vida significante; crenças, valores e compromissos; momentos de comunhão ou harmonia com Deus ou com o universo; propósito da vida e o que é uma pessoa religiosa. Os resultados foram discutidos a luz da logoterapia e análise existencial de Viktor Frankl
Anomia organizacional: Discussão conceitual e desenvolvimento de escala
Authors: Aguiar de Souza Marcos , Ribas Junior Rodolfo De Castro
Published: May 2014

A anomia pode ser definida, entre outros aspectos, como sentimentos de alienação, inutilidade, despropósito, isolamento, confusão ou ansiedade vividos por indivíduos, grupos ou sociedades como resultado da ausência de normas, valores e ideais. O conceito tem sido cada vez mais empregado com o objetivo de explicar algumas das consequências das rápidas e profundas mudanças econômicas, sociais e políticas observadas nas últimas décadas. A anomia também tem sido empregada para explicar o comportamento de indivíduos em organizações. O presente trabalho tem basicamente três objetivos. Em primeiro lugar, discute-se o conceito de anomia e sua relação com normas sociais. Na sequência, são examinadas algumas pesquisas sobre anomia. Finalmente, é apresentado o desenvolvimento e validação psicométrica da Escala de Anomia Organizacional. Análises fatoriais exploratórias indicaram que a escala apresenta propriedades psicométricas adequadas. Foram identificadas correlações inversas e significativas entre medidas de anomia, autoconceito profissional e percepção de suporte organizacional, fornecendo bons indicadores da validade externa do instrumento.
Bullying na perspectiva de adolescentes que cometeram ato infracional
Authors: Osório Comis Thiago , Cardoso Siqueira Aline
Published: May 2014

A violência entre pares tem sido considerada há muito tempo um significante problema social com consequências potencialmente sérias para agressores e vítimas. Assim, o impacto do bullying pode ser devastador, visto que os perpetradores podem desenvolver comportamento antissocial e as vítimas podem até cometer suicídio. O objetivo deste estudo foi investigar o fenômeno bullying em adolescentes que cumprem medida socioeducativa. Foi realizada uma entrevista com cinco adolescentes, de 16 a 17 anos, que cumpriam medida socioeducativa de liberdade assistida. Entre os resultados destaca-se que todos já haviam se envolvido em algum episódio de bullying, tendo assumido o papel de agressor, vítima ou testemunha, e demonstrando flexibilidade dos papéis no fenômeno. Os jovens não apresentaram clareza sobre o que é o bullying, contudo, estavam cientes dos danos causados por essa violência. Programas de intervenção nas escolas que favoreçam a comunicação entre os jovens, os professores e as famílias, o esclarecimento sobre o bullying e suas consequências, bem como a construção de estratégias efetivas de enfrentamento do fenômeno são necessários.
Estresse em docentes universitários da saúde: situações geradoras, sintomas e estratégias de enfrentamento
Authors: Sanches Elizabeth Navas , France Santos Julius Diego de
Published: May 2014

O estresse relacionado ao trabalho é compreendido como uma resposta às situações em que a pessoa percebe seu ambiente de trabalho como ameaçador às necessidades de realização pessoal e profissional e/ou a sua saúde física/mental, prejudicando a interação com o trabalho e com o ambiente. Este estudo teve como objetivos analisar as situações geradoras do estresse ocupacional, os sintomas e as estratégias de enfrentamento em docentes universitários da área da saúde, em uma instituição de Ensino Superior. Foram entrevistados, entre outubro e novembro de 2009, 18 professores, sendo 12 do sexo feminino e seis do masculino, com idade variando de 36 a 66 anos. Para levantar as situações geradoras de estresse e as estratégias de enfrentamento, foi aplicada uma entrevista semiestruturada. Os sintomas de estresse foram obtidos por questionário. As entrevistas foram analisadas por meio da análise de conteúdo temático e os sintomas de estresse, em frequência simples, foram relacionados aos demais achados. Com os resultados, percebeu-se que as situações geradoras de estresse foram lidar com alunos despreparados; sobrecarga de trabalho; contexto da universidade; preocupação do docente com a aprendizagem do aluno e prazos institucionais. As estratégias de enfrentamento mais utilizadas foram: autocontrole; suporte social; resolução de problemas e reavaliação positiva. Dentre os principais sintomas de estresse encontrados destacam-se a tensão muscular, problemas com a memória, insônia, cefaleia, perda do senso de humor, sensação de desgaste físico, irritabilidade, sensibilidade emotiva excessiva e ansiedade.
The spiritual dimension of perceived life satisfaction in heart attack
Authors: Baldacchino Donia R
Published: May 2014

This descriptive exploratory study was conducted in Malta in the local acute general hospital. The spiritual dimension of life satisfaction was explored twice by audio-taped face to face interviews on patients, aged > 65 years old with heart attack across the first three months (Time 1: n = 63; Time 2: n = 51) following onset of myocardial infarction. The study was guided by the theory: hierarchy of human needs. The findings identified two main themes namely: positive and negative spiritual influencing factors. The positive spiritual enhancing factors included family relationships, achievement of life goals and helping others. The spiritual negative influencing factors consisted of unfinished business and unachieved goals in life. The spiritual dimension was oriented towards finding meaning and purpose in life and turning to God for empowerment to cope with their holistic needs. Similarities were found between the findings of both data collection. While acknowledging the limitations of the study, recommendations were set to the hospital management, education sector and further research
Bases teológicas cristãs para o discernimento do pluralismo religioso
Authors: Ribeiro Claudio De Oliveira
Published: May 2014

A pesquisa girou em torno de possibilidades de discernimento bíblico-teológico das realidades sociais marcadas pelo pluralismo religioso. Metodologicamente, três passos foram dados: (i) a identificação da noção bíblica de alteridade, (ii) a identificação da abertura ao diálogo e a prática interativa que a visão trinitária da fé cristã oferece, e (iii) um levantamento das questões em torno do desafio da visão cristológica diante do quadro de valorização do pluralismo religioso. Os resultados da pesquisa mostram que cada expressão religiosa tem sua proposta salvífica e de fé, que deve ser aceita, respeitada, valorizada e aprimorada a partir de diálogo e aproximação mútuos. Tal perspectiva não anula nem diminui o valor das identidades religiosas — no caso da fé cristã, a importância de Cristo —, mas leva-as a um aprofundamento e amadurecimento, movidos pelo diálogo e pela confrontação justa, amável e corresponsável. Assim, a fé cristã, por exemplo, seria reinterpretada a partir do confronto dialógico e criativo com as demais fés. O mesmo deve se dar com toda e qualquer tradição religiosa.
Sentidos da morte segundo A Igreja de Jesus Cristo dos Santos dos Últimos Dias
Authors: Peressute Ariana , Hola Adriano Furtado
Published: May 2014

O objetivo deste trabalho é descrever aspectos dos fundamentos doutrinários de A Igreja de Jesus Cristo dos Santos dos Últimos Dias, no que concerne principalmente ao tema da morte. Espera-se encontrar contribuições acerca da seguinte questão: a proposta doutrinária da Igreja de Jesus Cristo dos Santos dos Últimos Dias é capaz de servir como recurso para o enfrentamento do luto? Realizou-se análise documental, a fim de colher dados básicos sobre sua doutrina, no que concerne à questão da morte, para verificar a hipótese de que a adesão a uma religião pode estar vinculada às respostas existenciais que o ser humano tanto busca e que pode servir de apoio para amenizar o sofrimento causado pela morte de alguém próximo. Foi realizada uma seleção de artigos na revista mensal da Igreja, bem como nos livros oficiais, nos capítulos que enunciavam algo relacionado à morte ou à adversidade, e descreveu-se o que a Igreja pensa a respeito. Conclui-se, pela análise de depoimentos, que a Igreja é uma fonte de conhecimento e consolo para seus membros, nos momentos de perda e enfrentamento da morte, e que o estudo do tema é pertinente para o desenvolvimento de todo e qualquer ser humano.
O “canto do cisne” do Leonardo da Vinci russo: introdução à obra carcerária de Pavel A. Florenskij
Authors: Fernandes Márcio Luiz , Žak Lubomir
Published: May 2014

P. A. Florenskij (1882-1937), pensador e cientista russo, reconhecido pelo seu poliédrico interesse no campo do conhecimento, foi um dos defensores da necessidade de um pensamento capaz de aproximar e descrever o real em sua multiforme complexidade. O eloquente e convincente testemunho deste pensamento é a sua copiosa e ampla produção filosófico-teológica e científica. Em 1933, quando regime soviético decidiu levar Florenskij para a prisão em um campo de concentração, as cartas escritas aos familiares tornaram-se ocasião para que ele pudesse refletir pela última vez sobre aquelas intuições originais que estavam na base do seu projeto sobre o “pensamento integral”. Este artigo pretende mostrar como esta particular intenção — com suas características e aplicações — está presente na correspondência carcerária. O objetivo principal será apresentar as cartas do gulag como uma obra que consegue concretizar o ambicioso e sempre atual projeto de Florenskij em um modo lúcido e exemplar, demonstrando sua funcionalidade até mesmo nas condições dramáticas e proibitivas de vida e trabalho.
Improved transport estimate of the East Icelandic Current 2002–2012
Authors: Macrander Andreas , Valdimarsson Héðinn , Jónsson Steingrímur
Published: May 2014

The East Icelandic Current (EIC) is one of the major export pathways from the Iceland Sea north of Iceland, carrying mostly cold and fresh waters of Arctic origin. In this study, volume and freshwater transports are estimated using current profiles and salinity time series from a mooring deployed from 2011 to 2012 over the insular slope northeast of Iceland. These data are extended by hydrographic sections spanning the entire EIC four times per year. In combination with altimetry, geostrophic current profiles of the whole section are obtained for the period 2002–2012. The data are analyzed with respect to volume and freshwater transport variability and their relation to atmospheric forcing. The observations show a mean transport of 0.75 ± 0.08 Sv, and a mean freshwater transport of 3.4 ± 0.3 mSv in the upper 170 m. There is large interannual variability which appears to depend more on local conditions rather than large‐scale atmospheric forcing. The freshwater transport is small compared to the export in the East Greenland Current.
Characterization and variability of particle size distributions in Hudson Bay, Canada
Authors: Xi Hongyan , Larouche Pierre , Tang Shilin , Michel Christine
Published: May 2014

Particle size distribution (PSD) plays a significant role in many aspects of aquatic ecosystems, including phytoplankton dynamics, sediment fluxes, and optical scattering from particulates. As of yet, little is known on the variability of particle size distribution in marine ecosystems. In this study, we investigated the PSD properties and variability in Hudson Bay based on measurements from a laser diffractometer (LISST‐100X Type‐B) in concert with biogeochemical parameters collected during summer 2010. Results show that most power‐law fitted PSD slopes ranged from 2.5 to 4.5, covering nearly the entire range observed for natural waters. Offshore waters showed a predominance of smaller particles while near the coast, the effect of riverine inputs on PSD were apparent. Particulate inorganic matter contributed more to total suspended matter in coastal waters leading to lower PSD slopes than offshore. The depth distribution of PSD slopes shows that larger particles were associated with the pycnocline. Below the pycnocline, smaller particles dominated the spectra. A comparison between a PSD slope‐based method to derive phytoplankton size class (PSC) and pigment‐based derived PSC showed the two methods agreed relatively well. This study provides valuable baseline information on particle size properties and phytoplankton composition estimates in a sub‐arctic environment subject to rapid environmental change.
Cross‐shore tracer exchange between the surfzone and inner‐shelf
Authors: Hally‐Rosendahl Kai , Feddersen Falk , Guza R. T.
Published: May 2014

Cross‐shore tracer exchange between the surfzone and inner‐shelf is examined using temperature and dye measurements at an approximately alongshore‐uniform beach. An alongshore‐oriented plume is created by releasing dye continuously for 4.5 h in a surfzone alongshore current. The plume is sampled for 13 h from the release point to 700 m downstream, between the shoreline and 250 m offshore (6 m water depth). Within the surfzone (≤2 m depth), water is relatively warm, and dye is vertically well mixed. On the inner‐shelf (3–6 m depth), alongshore currents are weak, and elevated temperature and dye co‐occur in 25–50 m wide alongshore patches. Within the patches, dye is approximately depth‐uniform in the warm upper 3 m where thermal stratification is weak, but decreases rapidly below 3 m with a strong thermocline. Dye and temperature vertical gradients are correlated, and dye is not observed below 18 °C. The observations and a model indicate that, just seaward of the surfzone, thermal stratification inhibits vertical mixing to magnitudes similar to those in the ocean interior. Similar surfzone and inner‐shelf mean alongshore dye dilution rates are consistent with inner‐shelf dye properties being determined by local cross‐shore advection. The alongshore‐patchy and warm inner‐shelf dye is ejected from the surfzone by transient rip currents. Estimated Stokes drift driven cross‐shore exchange is small. The transient rip current driven depth‐normalized heat flux out of the surfzone has magnitude similar to those of larger‐scale shelf processes. Dye recycling, from the inner‐shelf back to the surfzone, is suggested by relatively long surfzone dye residence times.
Global ocean current reconstruction from altimetric and microwave SST measurements
Authors: González‐Haro C. , Isern‐Fontanet J.
Published: May 2014

Ocean currents are a key component to understanding many oceanic and climatic phenomena and knowledge of them is crucial for both navigation and operational applications. Currently, they are derived from Sea Surface Height (SSH) measurements provided by altimeters. However, distances between tracks and the limited number of available altimeters lead to errors in the accurate location of oceanic currents. In this study, we investigate the capability of Sea Surface Temperature (SST) observations to reconstruct surface currents at a global scale. The methodology we use consists of estimating the stream function by taking the phase from SST and the spectrum of SSH and then comparing it with altimetric measurements. Results reveal that SST provided by microwave radiometers can be used to retrieve ocean currents during winter near the major extratropical current systems, which are characterized by an intense mesoscale activity and the presence of strong thermal gradients. We have also found that surface ocean current reconstruction based on Surface Quasi‐Geostrophic approach can be improved if the information about the energy spectrum provided by altimeters is used. This points to the development of a new method of reconstructing ocean currents based on the combination of the phase of SST images with the energy spectrum derived from along‐track altimetric measurements.
Vertical velocity in shallow convection for different plume types
Authors: Wang Xiaocong , Zhang Minghua
Published: May 2014

This study investigates the bulk budgets of the vertical velocity and its parameterization in convective cores, convective updrafts, and clouds by using large‐eddy simulation (LES) of four shallow convection cases in the Global Energy and Water Cycle Experiment (GEWEX) Cloud System Study (GCSS) programs. The relative magnitudes of the dominant momentum budget terms for the three types of plumes are presented. For all shallow cumulus except stratocumulus, the buoyancy force and the subplume transport in the core plume are the momentum source that offset the pressure gradient force. In the cloud updraft and cloud plumes, the buoyancy source is dominant in the lower and middle parts of the clouds, while the subgrid transport is a dominant source in the upper part, and the entrainment term is also a momentum source. For the stratocumulus, the subplume transport is a sink almost in the whole convective layer. For all types of plumes, the Simpson and Wiggert (1969) equation is found to be good paramaterization of the mean plume vertical velocity when appropriate scaling coefficients to buoyancy and entrainment terms are used. Optimal forms of the Simpson and Wiggert equation are given for convective cores, convective updrafts, and convective clouds. Results are compared with other studies published in the literature.
Brief Communication: Quantitative‐ and molecular‐genetic differentiation in humans and chimpanzees: Implications for the evolutionary processes underlying cranial diversification
Authors: Weaver Timothy D.
Published: May 2014

Estimates of the amount of genetic differentiation in humans among major geographic regions (e.g., Eastern Asia vs. Europe) from quantitative‐genetic analyses of cranial measurements closely match those from classical‐ and molecular‐genetic markers. Typically, among‐region differences account for ∼10% of the total variation. This correspondence is generally interpreted as evidence for the importance of neutral evolutionary processes (e.g., genetic drift) in generating among‐region differences in human cranial form, but it was initially surprising because human cranial diversity was frequently assumed to show a strong signature of natural selection. Is the human degree of similarity of cranial and DNA‐sequence estimates of among‐region genetic differentiation unusual? How do comparisons with other taxa illuminate the evolutionary processes underlying cranial diversification? Chimpanzees provide a useful starting point for placing the human results in a broader comparative context, because common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) are the extant species most closely related to humans. To address these questions, I used 27 cranial measurements collected on a sample of 861 humans and 263 chimpanzees to estimate the amount of genetic differentiation between pairs of groups (between regions for humans and between species or subspecies for chimpanzees). Consistent with previous results, the human cranial estimates are quite similar to published DNA‐sequence estimates. In contrast, the chimpanzee cranial estimates are much smaller than published DNA‐sequence estimates. It appears that cranial differentiation has been limited in chimpanzees relative to humans. Am J Phys Anthropol 154:615–620, 2014. © 2014 Wiley Periodicals, Inc.
Decreasing bacterial cross‐contamination with a pulsating nasal irrigation device
Authors: Keen Mark , Chen Philip G. , Wormald Peter‐John
Published: May 2014

Background

The use of nasal irrigation in the management of postoperative endoscopic sinus surgery (ESS) patients is commonplace; however, the potential contamination of these bottles is concerning. The Sinugator® cordless pulsating nasal wash (NeilMed Pharmaceuticals, Inc., Santa Rosa, CA) is a battery‐operated, positive pressure, pulsatile pump with a unidirectional flow. The principal aim of this study was to determine the incidence of cross‐contamination using the pulsating nasal irrigation device and compare it with the traditional squeeze bottle.

Methods

Eleven post‐ESS patients were given a NeilMed Sinugator nasal wash to use 3 times per day. A sterile nasal swab was obtained at the initial and second postoperative visits. A swab of the plastic irrigation reservoir was collected at the second visit.

Results

The overall contamination rate of bottles was found to be 45%. During the study several different organisms were cultured in the nose and bottles. The most commonly isolated organisms were coliforms and Staphylococcus aureus. We did not observe concomitant organisms in the nasal cultures and bottles in any subject.

Conclusion

Despite using a motorized irrigation device, patients and their bottles grew positive cultures. However, no cross‐contamination between the patients and bottles was identified, which can be attributed to a design that minimizes backwash.
Guest‐Induced Photophysical Property Switching of Artificial Light‐Harvesting Dendrimers
Authors: Jeong Young‐Hwan , Son Minjung , Yoon Hongsik , Kim Pyosang , Lee Do‐Hyung , Kim Dongho , Jang Woo‐Dong
Published: May 2014

An artificial light‐harvesting multiporphyrin dendrimer (8PZnPFB) composed of a focal freebase porphyrin (PFB) with eight zinc(II) porphyrin (PZn) wings exhibited unique photophysical property switching in response to specific guest molecule binding. UV/Vis titration studies indicated stable 1:2 host–guest complex formation between 8PZnPFB and meso‐tetrakis(4‐pyridyl)‐porphyrin (TPyP) for which the first and second association constants were estimated to be >108 M−1 and 3.0×107 M−1, respectively. 8PZnPFB originally shows 94 % energy transfer efficiency from PZn to the focal PFB. By the formation of the host–guest complex (8PZnPFB⋅2TPyP) the emission intensity of 8PZnPFB is significantly decreased, and an ultrafast charge separation state is generated. The energy transfer process from PZn wings to the PFB core in 8PZnPFB is almost entirely switched to an electron transfer process by the formation of 8PZnPFB⋅2TPyP.
Organic Photovoltaics: Elucidating the Ultra‐Fast Exciton Dissociation Mechanism in Disordered Materials
Authors: Heitzer Henry M. , Savoie Brett M. , Marks Tobin J. , Ratner Mark A.
Published: May 2014

Organic photovoltaics (OPVs) offer the opportunity for cheap, lightweight and mass‐producible devices. However, an incomplete understanding of the charge generation process, in particular the timescale of dynamics and role of exciton diffusion, has slowed further progress in the field. We report a new Kinetic Monte Carlo model for the exciton dissociation mechanism in OPVs that addresses the origin of ultra‐fast (<1 ps) dissociation by incorporating exciton delocalization. The model reproduces experimental results, such as the diminished rapid dissociation with increasing domain size, and also lends insight into the interplay between mixed domains, domain geometry, and exciton delocalization. Additionally, the model addresses the recent dispute on the origin of ultra‐fast exciton dissociation by comparing the effects of exciton delocalization and impure domains on the photo‐dynamics.This model provides insight into exciton dynamics that can advance our understanding of OPV structure–function relationships.
Ligand‐Enabled Triple CH Activation Reactions: One‐Pot Synthesis of Diverse 4‐Aryl‐2‐quinolinones from Propionamides
Authors: Deng Youqian , Gong Wei , He Jian , Yu Jin‐Quan
Published: May 2014

Diverse 4‐aryl‐2‐quinolinones are prepared from propionamides in one pot by ligand‐promoted triple sequential CH activation reactions and a stereospecific Heck reaction. In these cascade reactions, three new CC bonds and one CN bond are formed to rapidly build molecular complexity from propionic acid.
Comparative α‐Helicity of Cyclic Pentapeptides in Water
Authors: de Araujo Aline D. , Hoang Huy N. , Kok W. Mei , Diness Frederik , Gupta Praveer , Hill Timothy A. , Driver Russell W. , Price David A. , Liras Spiros , Fairlie David P.
Published: May 2014

Helix‐constrained polypeptides have attracted great interest for modulating protein–protein interactions (PPI). It is not known which are the most effective helix‐inducing strategies for designing PPI agonists/antagonists. Cyclization linkers (X1–X5) were compared here, using circular dichroism and 2D NMR spectroscopy, for α‐helix induction in simple model pentapeptides, Ac‐cyclo(1,5)‐[X1‐Ala‐Ala‐Ala‐X5]‐NH2, in water. In this very stringent test of helix induction, a Lys1→Asp5 lactam linker conferred greatest α‐helicity, hydrocarbon and triazole linkers induced a mix of α‐ and 310‐helicity, while thio‐ and dithioether linkers produced less helicity. The lactam‐linked cyclic pentapeptide was also the most effective α‐helix nucleator attached to a 13‐residue model peptide.
Direct Observation of the Orientation Dynamics of Single Protein‐Coated Nanoparticles at Liquid/Solid Interfaces
Authors: Xu Dong , He Yan , Yeung Edward S.
Published: May 2014

We have observed the rotational dynamics of single protein‐coated gold nanorods (AuNRs) on C18‐modified silica surfaces in real time by dual‐channel polarization dark‐field microscopy. Four different rotational states were identified, depending on the apparent strength of interactions between the AuNRs and the surface. The distributions of the states could be regulated by adjusting the salt concentration, and the state transitions were verified by monitoring the entire desorption process of a single AuNR. Our study provides insight into the interfacial orientation and dynamics of nanoparticles and could be useful for in vitro biophysics and the separation of proteins.
Building Proficient Enzymes with Foldamer Prostheses
Authors: Mayer Clemens , Müller Manuel M. , Gellman Samuel H. , Hilvert Donald
Published: May 2014

Foldamers are non‐natural oligomers that adopt stable conformations reminiscent of those found in proteins. To evaluate the potential of foldameric subunits for catalysis, semisynthetic enzymes containing foldamer fragments constructed from α‐ and β‐amino acid residues were designed and characterized. Systematic variation of the α→β substitution pattern and types of β‐residue afforded highly proficient hybrid catalysts, thus demonstrating the feasibility of expanding the enzyme‐engineering toolkit with non‐natural backbones.
Towards a Practical Development of Light‐Driven Acceptorless Alkane Dehydrogenation
Authors: Chowdhury Abhishek Dutta , Weding Nico , Julis Jennifer , Franke Robert , Jackstell Ralf , Beller Matthias
Published: May 2014

The efficient catalytic dehydrogenation of alkanes to olefins is one of the most investigated reactions in organic synthesis. In the coming years, an increased supply of shorter‐chain alkanes from natural and shale gas will offer new opportunities for inexpensive carbon feedstock through such dehydrogenation processes. Existing methods for alkane dehydrogenation using heterogeneous catalysts require harsh reaction conditions and have a lack of selectivity, whereas homogeneous catalysis methods result in significant waste generation. A strong need exists for atom‐efficient alkane dehydrogenations on a useful scale. Herein, we have developed improved acceptorless catalytic systems under optimal light transmittance conditions using trans‐[Rh(PMe3)2(CO)Cl] as the catalyst with different additives. Unprecedented catalyst turnover numbers are obtained for the dehydrogenation of cyclic and linear (from C4) alkanes and liquid organic hydrogen carriers. These reactions proceed with unique conversion, thereby providing a basis for practical alkane dehydrogenations.
Synthesis of Long‐Sought C66 with Exohedral Stabilization
Authors: Gao Cong‐Li , Li Xiang , Tan Yuan‐Zhi , Wu Xin‐Zhou , Zhang Qianyan , Xie Su‐Yuan , Huang Rong‐Bin
Published: May 2014

Previously reported fused‐pentagon fullerenes stabilized by exohedral derivatization do not share the same cage with those stabilized by endohedral encapsulation. Herein we report the crystallographic identification of #4348C66Cl10, which has the same cage as that of previously reported Sc2@C66. According to the geometrical data of #4348C66Cl10, both strain relief (at the fused pentagons) and local aromaticity (on the remaining sp2‐hybrided carbon framework) contribute to the exohedral stabilization of this long‐sought 66 carbon atom cage.
A Tandem In Situ Peptide Cyclization through Trifluoroacetic Acid Cleavage
Authors: Chandra Koushik , Roy Tapta Kanchan , Shalev Deborah E. , Loyter Abraham , Gilon Chaim , Gerber R. Benny , Friedler Assaf
Published: May 2014

We present a new approach for peptide cyclization during solid phase synthesis under highly acidic conditions. Our approach involves simultaneous in situ deprotection, cyclization and trifluoroacetic acid (TFA) cleavage of the peptide, which is achieved by forming an amide bond between a lysine side chain and a succinic acid linker at the peptide N‐terminus. The reaction proceeds via a highly active succinimide intermediate, which was isolated and characterized. The structure of a model cyclic peptide was solved by NMR spectroscopy. Theoretical calculations support the proposed mechanism of cyclization. Our new methodology is applicable for the formation of macrocycles in solid‐phase synthesis of peptides and organic molecules.
Single‐Particle Tracking and Modulation of Cell Entry Pathways of a Tetrahedral DNA Nanostructure in Live Cells
Authors: Liang Le , Li Jiang , Li Qian , Huang Qing , Shi Jiye , Yan Hao , Fan Chunhai
Published: May 2014

DNA is typically impermeable to the plasma membrane due to its polyanionic nature. Interestingly, several different DNA nanostructures can be readily taken up by cells in the absence of transfection agents, which suggests new opportunities for constructing intelligent cargo delivery systems from these biocompatible, nonviral DNA nanocarriers. However, the underlying mechanism of entry of the DNA nanostructures into the cells remains unknown. Herein, we investigated the endocytotic internalization and subsequent transport of tetrahedral DNA nanostructures (TDNs) by mammalian cells through single‐particle tracking. We found that the TDNs were rapidly internalized by a caveolin‐dependent pathway. After endocytosis, the TDNs were transported to the lysosomes in a highly ordered, microtubule‐dependent manner. Although the TDNs retained their structural integrity within cells over long time periods, their localization in the lysosomes precludes their use as effective delivery agents. To modulate the cellular fate of the TDNs, we functionalized them with nuclear localization signals that directed their escape from the lysosomes and entry into the cellular nuclei. This study improves our understanding of the entry into cells and transport pathways of DNA nanostructures, and the results can be used as a basis for designing DNA‐nanostructure‐based drug delivery nanocarriers for targeted therapy.
The Highly Lewis Acidic Dicationic Phosphonium Salt: [(SIMes)PFPh2][B(C6F5)4]2
Authors: Holthausen Michael H. , Mehta Meera , Stephan Douglas W.
Published: May 2014

The dicationic imidazolium‐phosphonium salt [(SIMes)PFPh2][B(C6F5)4]2 has been prepared and shown to exhibit remarkable Lewis acidity in stoichiometric reactions and acting as an effective Lewis acid catalyst for the hydrodefluorination of fluoroalkanes and the hydrosilylation of olefins.
Palladium‐Catalyzed Decarboxylative Cycloaddition of Vinylethylene Carbonates with Formaldehyde: Enantioselective Construction of Tertiary Vinylglycols
Authors: Khan Ajmal , Zheng Renfeng , Kan Yuhe , Ye Jiang , Xing Juxiang , Zhang Yong Jian
Published: May 2014

An efficient method for the enantioselective construction of tertiary vinylglycols through a palladium‐catalyzed asymmetric decarboxylative cycloaddition of vinylethylene carbonates with formaldehyde was developed. By using a palladium complex generated in situ from [Pd2(dba)3]⋅CHCl3 and a phosphoramidite ligand as a catalyst under mild reaction conditions, the process allows conversion of racemic 4‐substituted 4‐vinyl‐1,3‐dioxolan‐2‐ones into the corresponding 1,3‐dioxolanes, as methylene acetal protected tertiary vinylglycols, in high yields with good to excellent enantioselectivities.
Synthesis, characterization, and properties of a polyhedral oligomeric octadiphenylsulfonylsilsesquioxane
Authors: Li Ziqian , Yang Rongjie
Published: May 2014

A novel polyhedral oligomeric octadiphenylsulfonylsilsesquioxane (ODPSS) was synthesized from octaphenylsilsesquioxane and benzenesulfonyl chloride via a Friedel–Crafts reaction with a high yield. ODPSS was identified by Fourier transform infrared spectroscopy, 1H‐NMR, 13C‐NMR, 29Si‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI–TOF MS), wide‐angle X‐ray diffraction, and elemental analysis to be a kind of polyhedral oligomeric silsesquioxane of a T8R8 structure. ODPSS exhibited superior thermal stability according to thermogravimetric analysis. Its initial thermal decomposition temperature (Tonset) was at 491°C in air and 515°C in nitrogen. Thermal and mechanical properties of epoxy resin (EP) composites with ODPSS added were studied by differential scanning calorimetry and tensile testing. The results show that the incorporation of ODPSS at a low loading content not only improved the glass‐transition temperature of the EP composites but also enhanced their tensile strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40892.
Preparation and characterization of carboxymethyl starch under ultrasound‐microwave synergistic interaction
Authors: Shi Haixin , Yin Yanzhen , Jiao Shufei
Published: May 2014

Using native cassava starch as raw materials, carboxymethyl starch (CMS) was prepared by ethanol solvent method under the ultrasound‐microwave synergistic interaction. And the structure of CMS was characterized employing Fourier transform infrared (FTIR) spectrometer, scanning electron microscopy (SEM), X‐ray diffraction (XRD) and thermogravimetric analyzer. Typically, the optimal synthesis conditions for the preparation process confirmed by orthogonal experiment L18 (61 × 36) were shown as follows: the ultrasonic treatment temperature was fixed to 35°C and two steps alkalization was employed; the ultrasonic time was 40 min before alkalizing and the ultrasonic power was 220 W; the amount of sodium hydroxide was 8.8 g, the microwave alkalization time was 2 min; the amount of monochloroacetic acid was 11.34 g; the amount of 95% (v/v) ethanol was 70 mL; the microwave etherification time was 3 min. The degree of substitution of prepared CMS was 1.089 ± 0.041, which was increased 30.4% compared with the prepared sample without ultrasound‐microwave synergistic treatment. FTIR results showed that the strong COO characteristic absorption peaks of the stretching vibration were observed at 1613 and 1421 cm−1, which proved that the carboxymethylation of cassava starch was occurred. SEM results suggested that there were many cracks and dents on CMS granules; and, XRD results indicated that the carboxymethylation of starch occurred both in amorphous region and crystalline region, the noticeable damage of crystalline region by carboxymethylation was observed. Thermogravimetric analysis (TG) and derivative TG showed that thermal stability of CMS changed better compared with native starch. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40906.
Processing of a multi‐layer polyetheretherketone composite for use in acetabular cup prosthesis
Authors: Abdullah Mohammed Ruslan , Goharian Amirhossein , Abdul Kadir Mohammed Rafiq , Wahit Mat Uzir
Published: May 2014

The hydroxyapatite polyetheretherketone (HAPEEK) as a non‐degradable bioactive polymer composite material with coating of hydroxyapatite (HA) as a bioactive ceramic material can enhance the osteointegration of carbon fiber reinforced polyetheretherketone (CFRPEEK) as a non‐degradable bioinert polymer composite. This study describes the joining process of CFRPEEK and HAPEEK beam components and coating process of HA on the HAPEEK substrate to achieve the multi‐layer PEEK composite for use in the application of acetabular cup prosthesis. The CFRPEEK and HAPEEK components were ultrasonically welded while the HA was plasma sprayed on the HAPEEK substrate. Ultrasonic welding parameters (length and direction of the energy directors at the interface, welding time, and pressure) were investigated by single cantilever beam and lap shear tests to achieve the optimum bonding strength of CFRPEEK and HAPEEK components. Plasma spraying parameters (e.g., surface speed, powder feed, current, primary gas flow, and system voltage) were altered to achieve the good adhesion of HA coating on the HAPEEK substrate, which was evaluated by scratch test. The results showed that the proposed multi‐layer composite was successfully processed by carrying out the ultrasonic welding and plasma spraying coating processes. The outcomes of this study could be used to develop a non‐metal acetabular cup prosthesis using the proposed multi‐layer composition. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40915.
Self‐catalyzed silicon‐containing phthalonitrile resins with low melting point, excellent solubility and thermal stability
Authors: Zhang Zongbo , Li Zheng , Zhou Heng , Lin Xiankai , Zhao Tong , Zhang Mingyan , Xu Caihong
Published: May 2014

A series of silicon‐containing self‐catalyzed phthalonitrile derivatives (SiPNs) have been successfully synthesized from reaction of 4‐(4‐aminophenoxy)phthalonitrile (APN) with corresponding chlorosilanes. The chemical structures of the SiPNs were confirmed by spectroscopic techniques. The introduction of silicon‐containing unit into the phthalonitrile structure has dramatically decreased the melting point from 143°C for APN to 40–60°C for the new SiPNs, which also exhibit improved solubility and are soluble in many common solvents. Differential scanning calorimetry analysis showed that they possess the self‐catalyzed behavior with the temperature of exothermic peak due to the self‐catalyzed reaction between 255 and 281°C. The cured SiPNs exhibit excellent thermal stability with glass transition temperature above 450°C, the temperature of 5% weight loss in range of 535–570°C under nitrogen, and 543–562°C under air. Their char yields at 1000°C are in the range of 80.2–82.6% in nitrogen, and 10.1–12.5% in air, respectively. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40919.
A Hybrid Coumarin–Thiazole Fluorescent Sensor for Selective Detection of Bisulfite Anions in Vivo and in Real Samples
Authors: Peng Meng‐Jiao , Yang Xiao‐Feng , Yin Bing , Guo Yuan , Suzenet Franck , En Da , Li Jin , Li Chang‐Wei , Duan Yu‐Wei
Published: May 2014

A hybrid coumarin–thiazole compound was developed as a novel ratiometric and colorimetric sensor for bisulfite anions. Structure identification of the compound was confirmed by 1H NMR, 13C NMR, 1H,1H COSY, heteronuclear single quantum coherence (HSQC), IR, and HRMS spectroscopy. The detection of bisulfite anions was performed through the Michael addition of the bisulfite anion toward the hybrid coumarin–thiazole sensor. The reaction between the sensor and bisulfite anion caused the fluorescence intensity to decrease at 600 nm and to increase at 450 nm and simultaneously yielded a visible color change from purplish red to colorless because the π conjugation between thiazole and coumarin was blocked. The sensor possessed high selectivity and sensitivity for bisulfite with respect to other common anions in aqueous solution. Moreover, the practical value of this sensor was confirmed by its application in the detection of bisulfite anion in human breast adenocarcinoma cells and granulated sugar.
Modeling mechanical signals on the surface of µCT and CAD based rapid prototype scaffold models to predict (early stage) tissue development
Authors: Hendrikson W. J. , van Blitterswijk C. A. , Verdonschot N. , Moroni L. , Rouwkema J.
Published: May 2014

In the field of tissue engineering, mechano‐regulation theories have been applied to help predict tissue development in tissue engineering scaffolds in the past. For this, finite element models (FEMs) were used to predict the distribution of strains within a scaffold. However, the strains reported in these studies are volumetric strains of the material or strains developed in the extracellular matrix occupying the pore space. The initial phase of cell attachment and growth on the biomaterial surface has thus far been neglected. In this study, we present a model that determines the magnitude of biomechanical signals on the biomaterial surface, enabling us to predict cell differentiation stimulus values at this initial stage. Results showed that magnitudes of the 2D strain—termed surface strain—were lower when compared to the 3D volumetric strain or the conventional octahedral shear strain as used in current mechano‐regulation theories. Results of both µCT and CAD derived FEMs from the same scaffold were compared. Strain and fluid shear stress distributions, and subsequently the cell differentiation stimulus, were highly dependent on the pore shape. CAD models were not able to capture the distributions seen in the µCT FEM. The calculated mechanical stimuli could be combined with current mechanobiological models resulting in a tool to predict cell differentiation in the initial phase of tissue engineering. Although experimental data is still necessary to properly link mechanical signals to cell behavior in this specific setting, this model is an important step towards optimizing scaffold architecture and/or stimulation regimes. Biotechnol. Bioeng. 2014;111: 1864–1875. © 2014 Wiley Periodicals, Inc.