bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential expression of the glucose transporter geneglcHin response to glucose and light in marine picocyanobacteria
Authors: Moreno-Cabezuelo José Ángel , López-Lozano Antonio , Díez Jesús , García-Fernández José Manuel
Published: January 2019

Background

Our team discovered thatProchlorococcuscan take up glucose, in a process that changes the transcriptional pattern of several genes involved in glucose metabolization. We have also shown thatglcHencodes a very high affinity glucose transporter, and that glucose is taken up by naturalProchlorococcuspopulations. We demonstrated that the kinetic parameters of glucose uptake show significant diversity in differentProchlorococcusandSynechococcusstrains. Here, we tested whether the transcriptional response ofglcHto several glucose concentrations and light conditions was also different depending on the studied strain.

Methods

Cultures were grown in the light, supplemented with five different glucose concentrations or subjected to darkness, and cells harvested after 24 h of treatment. qRT-PCR was used to determineglcHexpression in fourProchlorococcusand twoSynechococcusstrains.

Results

In all studied strainsglcHwas expressed in the absence of glucose, and it increased upon glucose addition to cultures. The changes differed depending on the strain, both in the magnitude and in the way cells responded to the tested glucose concentrations. Unlike the other strains,SynechococcusBL107 showed the maximum glucose uptake at 5 nM glucose. Darkness induced a strong decrease inglcHexpression, especially remarkable inProchlorococcusMIT9313.

Discussion

Our results suggest that marine picocyanobacteria are actively monitoring the availability of glucose, to upregulateglcHexpression in order to exploit the presence of sugars in the environment. The diverse responses observed in different strains suggest that the transcriptional regulation of glucose uptake has been adjusted by evolutive selection. Darkness promotes a strong decrease inglcHexpression in all studied strains, which fits with previous results on glucose uptake inProchlorococcus. Overall, this work reinforces the importance of mixotrophy for marine picocyanobacteria.
The distribution and frequency of detection of woodland birds after selective logging of a small woodland remnant in an agricultural landscape in inland southern Australia
Authors: Murphy Michael J.
Published: January 2019

The majority of studies into the response of birds to logging in Australian forests has been done in forest-dominated landscapes or relatively large forest blocks, where the surrounding landscape can ameliorate impacts. This is the first study to examine the response of birds to logging of a small, relatively isolated woodland remnant in a landscape dominated by agriculture, with a focus on declining woodland birds. Approximately two thirds of a 120 ha cypress-eucalypt woodland remnant was selectively logged. Eighty bird species in total were recorded 2–3½ years after logging, including 18 recognised as declining woodland birds. Sixty-four species were recorded in the unlogged area and 72 in the logged area. Of the 31 species recorded sufficiently frequently for analysis, 19 showed no statistical difference in occurrence between logged and unlogged areas at the power of the study, nine were more prevalent in unlogged areas and three more prevalent in logged areas. Declining woodland birds comprised 22½% of overall species and 33% of those more prevalent in unlogged areas. Mapping of records enabled the response of a subset of species to be examined in greater detail. Four species illustrate the range of responses by declining woodland birds: Eastern Yellow Robin Eopsaltria australis was confined to unlogged areas, White-browed Babbler Pomatostomus superciliosus favoured unlogged areas, Varied Sittella Daphoenositta chrysoptera favoured proximity to unlogged areas and Red-capped Robin Petroica goodenovii was widely distributed in both logged and unlogged areas. The likelihood of recovery of local woodland bird populations is discussed in the context of limited landscape connectivity and the recent colonisation of the remnant by the hyper-aggressive Noisy Miner Manorina melanocephala. White-browed Babbler and Eastern Yellow Robin are considered to be at high risk of local extinction in the remnant.
I Simpósio Interdisciplinar de Órgãos e Sistemas
Authors: Araújo Roberto Paulo Correia de
Published: January 2019

Reconstruir o conhecimento científico e tecnológico de forma criativa, inovadora, questionadora, contemporânea se constitui no desafio imposto aos grupos de pesquisa. É possível se alcançar esta meta, desde que assimilada como política institucional permanente e cuidadosamente implementada no cotidiano do labor acadêmico nas salas de aula, nos laboratórios, nos ambientes destinados à promoção, à prevenção e ao tratamento da saúde, nas bibliotecas, enfim, em todos os espaços da Universidade. Inexiste outra fórmula para se alcançar este objetivo que não seja através da adequada formação acadêmico-profissional, mediante o compartilhamento de idéias e a cumplicidade de ideais aliados ao incentivo e financiamento responsável da pesquisa. 

Tendo como escopo a formação de Mestres e Doutores, o Programa de Pós-graduação Processos Interativos dos órgãos e Sistemas está voltado para a produção do conhecimento básico das Ciências Morfológicas, Ciências Fisiológicas e Ciências Patológicas a serviço da produção do conhecimento interdisciplinar das ciências da saúde sem perder de vista os distúrbios que comprometem a homeostasia. Visa a contribuir para o desenvolvimento de uma política de promoção e avanço da ciência capaz de gerar o saber renovado na busca pela excelência das práticas de cuidar e administrar. Este saber é construído a partir das atividades de pesquisa, ensino de graduação e de pós-graduação, extensão e prestação de serviços à comunidade. Nessa perspectiva, o processo do cuidar da saúde da coletividade resulta na preservação da qualidade da relação humana que se estabelece entre os indivíduos, famílias, grupos e comunidades, portanto, sempre voltado ao atendimento das suas necessidades universais e específicas, fundamentado na interdisciplinaridade da ciência, tecnologia, ética, bioética e biossegurança...
Delirium e deficiência colinérgica
Authors: Flôres Dimitri Gusmão , Castro Lucas De
Published: January 2019

Introdução: Delirium é uma disfunção cerebral aguda, caracterizada por um estado confusional, bastante prevalente em ambiente hospitalar. A despeito de um melhor conhecimento sobre diagnóstico, fatores de riscos e prognóstico, o delirium continua sem bases fisiopatológicas claras. Parece existir um papel importante de alguns neurotransmissores na sua gênese, tais como acetilcolina, serotonina, noradrenalina e dopamina. Evidências sugerem que a deficiência de acetilcolina tem papel fundamental na fisiopatologia do delirium. Objetivo: Revisar a literatura que trata da hipótese da deficiência colinérgica na patogênese do delirium. Metodologia: Realizado busca no PUBMED com os termos “delirium” e “acetylcholine” ou “cholinergic deficiency”. Os artigos selecionados foram analisados e novas buscas foram realizadas através das referências bibliográficas. Resultado: Descrição de evidências que envolvam o sistema colinérgico seja por redução na sua síntese, interferência na transmissão, desequilíbrio de neurotransmissores ou deficiência nos níveis séricos, como base fisiopatológica do delirium. Conclusão: A hipótese da deficiência colinérgica parece ter fundamental importância na origem do delirium.
Helicobacter pylori: Associação com o câncer gástrico e novas descobertas sobre os fatores de virulência
Authors: Barbosa Joel Antonio , Schinonni Maria Isabel
Published: January 2019

Objetivo: Realizar uma revisão bibliográfica sobre a ação da bactéria Helicobacter pylori nas alterações gastrointestinais visando a  entender o papel dos chamados “fatores de virulência”,  assim como estudar a associação do H. pylori com doenças gastrointestinais e os mecanismos imunológicos desencadeados pela presença desta bactéria. Método: Foram selecionados os trabalhos publicados em revistas indexadas nas bases de dados MedLine e PubMed, sob os unitermos “H. pylori”, “gastrite”, “câncer”, “resposta imune”, “Cag A” e “VacA” com maior ênfase nos artigos publicados nos últimos 5 anos. Resultado: Trinta e dois artigos foram selecionados, todos de revistas estrangeiras, sendo um dos trabalhos desenvolvido por grupo de cientistas brasileiros. Os artigos selecionados mostraram o amplo espectro de ação da H. pylori através de seus “fatores de virulência” tais como a vacuolização de células infectadas provocada pela proteína VacA e a adesão da bactéria às células através da atividade das adesinas e proteínas de membrana. Também foram descritas as interações da H. pylori com doenças gastrointestinais e com o sistema endócrino assim como as peculiaridades da resposta imunológica humoral e celular contra esta bactéria. Conclusões: Fica clara a importância epidemiológica da H. pylori por sua evidente associação com o câncer gástrico e o importante papel desempenhado pelos fatores de virulência codificados pela bactéria.
SUBJECT INDEX
Authors: Revista Ciências Médicas e Biológicas Revista Ciências Médicas e Biológicas
Published: January 2019

SUBJECT INDEX
ÍNDICE DE AUTOR / AUTHOR INDEX
Authors: Revista Ciências Médicas e Biológicas Revista Ciências Médicas e Biológicas
Published: January 2019

ÍNDICE DE AUTOR / AUTHOR INDEX
Delegação de funções ao pessoal auxiliar odontológico pelos cirurgiões-dentistas da cidade de Campina Grande - PB
Authors: Sales Cristiane Valeska Moura , Pinto Ana Emília Almeida , Cavalcanti Alessandro Leite , Lucas Rilva Suely de Castro C. , Lins Sérgio D‘Ávila
Published: January 2019

Este estudo avaliou a utilização do pessoal auxiliar odontológico pelos cirurgiões-dentistas com atuação em consultórios odontológicos privados no município de Campina Grande-PB. A amostra foi constituída por 67 profissionais selecionados dentre aqueles com registro no Conselho Regional de Odontologia - PB. Para a coleta dos dados, foi elaborado um questionário específico que envolvia as atividades desenvolvidas pelos auxiliares. Dentre os principais resultados, verificou-se que 71,7% (48) dos profissionais utilizam pessoal auxiliar. Contudo, apenas 39,6% (19) dos auxiliares possuem registro no Conselho Regional. Dentre as tarefas realizadas, a marcação de consultas foi a mais delegada (95,8%), seguida da organização dos arquivos e fichários (89,5%). Os resultados permitem concluir que há uma subutilização do pessoal auxiliar pelos dentistas e a eficiência da prática odontológica poderia ser maior se esses auxiliares fossem utilizados adequadamente.
Displasia cleidocraniana: aspectos clínicos e radiográficos e relato de um caso clínico
Authors: Silva Júnior Aurelício Novaes , Hernandez Pedro Antonio Gonzalez , Vargas Ivana Ardenghi , Corvello Paula Chiattone , Gehlen Daniela Leal Barreto , Hoffmann Renata Da Rocha , Gassen Humberto Thomazi
Published: January 2019

A Displasia Cleidocraniana (DCC) é caracterizada por múltiplas anormalidades, principalmente aquelas pertencentes ao esqueleto craniofacial e corporal, e também anormalidades buco-dentais. O objetivo deste artigo é apresentar o caso de uma paciente, gênero feminino, 25 anos, portadora de sinais característicos dessa entidade patológica. Os aspectos gerais da doença, assim como os sinais clínicos e radiográficos da síndrome são também discutidos e enfatizados, dada a sua rara ocorrência.
Desempenho funcional de crianças com paralisiacerebral diparéticas e hemiparéicas
Authors: Marinho Ana Paula S. , Souza Mayana De A. B. de , Pimentel Adriana M.
Published: January 2019

Na Paralisia Cerebral (PC), o ideal é associar o desempenho funcional com características topográficas e alterações de tônus. Entretanto, grande parte da bibliografia descreve apenas a doença e suas conseqüências, e, quando se avalia o desempenho funcional, não se consideram as diferenças existentes nos tipos de PC ou se utiliza apenas um tipo. Na literatura, foi encontrada apenas uma referência bibliográfica que diferencia diparéticos e hemiparéticos quanto ao seu autocuidado, e nenhuma que compare a mobilidade entre eles. Este trabalho teve por objetivo avaliar a relação do desempenho funcional de crianças com PC diparéticas e hemiparéticas. Para tanto, fez-se um estudo transversal com portadores de PC diparéticos e hemiparéticos espásticos, de ambos os sexos, de três a sete anos, que estavam realizando fisioterapia. Excluíram-se crianças que não andavam e (ou) com déficit cognitivo. Foram realizadas entrevistas com cuidadores, utilizando-se a parte 1 (desempenho funcional nas áreas de autocuidado e mobilidade) do Inventário de Avaliação Pediátrica de Incapacidade (PEDI), assim como um questionário com dados pessoais das crianças. Utilizou-se programa BioEstat 4.0, e o teste estatístico Mann-Whitney, para verificação da associação proposta. Aceitou-se α  0,05 como inferência estatística. A amostra foi composta de 40 crianças, 22 diparéticas e 18 hemiparéticas. A maioria era do sexo feminino (53%) e realizava tratamento associado à fisioterapia (88%). A área de autocuidado (p=0,16) não apresentou diferença entre os grupos. Todavia mobilidade, (p=0,02) sugere que o grupo hemiparético possui melhor desempenho funcional. Concluiu-se que os hemiparéticos possuem melhor mobilidade que os diparéticos, enquanto que, no autocuidado, não se observou diferença estatística entre os grupos.
Análise acústica da voz falada nos períodos pré e pós- menstrual: estudo comparativo
Authors: Souza Lourdes Bernadete Rocha de , Monteiro Daniely Freire , Araújo Thaisa Rafaela De Sousa
Published: January 2019

Este trabalho teve por objetivo analisar acusticamente a voz falada nos períodos pré e pós-menstrual, bem como verificar possíveis alterações vocais existentes nesse período, realizando um estudo comparativo. Participaram do estudo 27 mulheres, com idades entre 19 e 39 anos. Para análise acústica da voz, foram realizadas gravações da voz falada nos dois dias que antecedem o período menstrual e três dias após o término desse período. Os parâmetros analisados demonstraram alterações estatisticamente significantes entre os dois períodos. Concluiu-se que as alterações hormonais existentes nesse período influenciam de maneira significativa a voz, modificando a qualidade vocal, apesar de a maioria das participantes deste estudo não o perceberem.
Atividade de um exaguatório bucal com clorexidina a 0,12% sobre a microbiota sacarolítica da saliva
Authors: Moreira Ana Cristina Azevedo , Santos Tiago Afonso Maltez dos , Carneiro Milena Couto , Porto Mariana Ribeiro
Published: January 2019

Este trabalho avaliou a ação de um enxaguatório bucal com gluconato de clorexidina a 0,12% sobre o crescimento e produção de placa in vitro de estreptococos do grupo mutans e de outros microrganismos da saliva. A amostra foi composta por um pool de saliva, fracionada em duas partes, constituindo dois grupos. No grupo 1, adicionou-se 0,1 ml de saliva pura a tubos com caldo tioglicolato com 5% de sacarose e um bastão de vidro. No grupo 2, adicionou-se ao mesmo meio de cultura 0,1 ml de saliva previamente misturada a enxaguatório com gluconato de clorexidina a 0,12%, por 1 minuto. Após incubação a 37ºC, observou-se o aspecto dos meios de cultura e a presença de placa no bastão de vidro, seguindo-se de coloração de Gram e isolamento de estreptococos do grupo mutans. Em 100% dos tubos do grupo 1, observou-se produção de placa in vitro, turbidez e sedimento. Ao Gram, foram visualizados estreptococos, bacilos Gram positivos, bacilos Gram negativos, com alguns fusiformes e leveduras. Na cultura, foram isolados estreptococos do grupo mutans. No grupo 2, não houve produção de placa in vitro na maioria dos tubos (75%), e constatou-se escassez ou ausência de turbidez e sedimento, não sendo isolados estreptococos do grupo mutans. Nesse grupo, onde houve pouco crescimento bacteriano e placa in vitro (25%), foram isolados Streptococcus sp. Os resultados confirmaram a efetividade da clorexidina a 0,12% incorporada a enxaguatórios na redução da microbiota da saliva, inibição do crescimento de estreptococos do grupo mutans, leveduras e formação do biofilme dental.
Assistência pré-natal: cuidados executados e opinião da usuária do SUS
Authors: Justo Mariel Tobal , Toledo Flavia Danielle Rubim de , Tavares Beatriz Barco
Published: January 2019

O pré-natal de qualidade se reflete na redução da morbimortalidade materna e perinatal. Os objetivos deste estudo foram identificar os cuidados prestados às gestantes no pré-natal e suas opiniões sobre esse atendimento. É um estudo quantitativo, prospectivo e descritivo. Participaram 169 puérperas atendidas em um hospital de ensino, no interior do Estado de São Paulo, de julho a setembro de 2008. Os dados foram coletados da carteira do pré-natal e em uma entrevista, e transcritos em uma planilha de Excel 2003. Foram analisados a média e o desvio padrão, e foi comparada a presença de dúvidas das gestantes com o Teste Qui-Quadrado e o Teste Kruskal-Wallis, cujo nível de significância adotado foi de p< 0,05. Constatou-se que 24,9% eram adolescentes; 87,0% tinham companheiros; 100% realizaram o pré-natal; 80,4% iniciaram no 1º trimestre e, dessas, 78,0% compareceram a seis ou mais consultas e 86,3% fizeram os exames laboratoriais preconizados pelo PHPN; 77,2% não participaram de grupo de gestantes; 78,1% tinham dúvidas que não conseguiram sanar; 43,2% sugeriram que a equipe de saúde deve prestar melhor atendimento com mais atenção. Concluiu-se que essa assistência de pré-natal está dentro do determinado no PHPN, porém a educação da gestante, que é um dos objetivos do programa, foi falha, pois as mulheres não conseguiram sanar suas dúvidas durante o pré-natal, nem participaram de grupo de gestantes. Ainda, relataram a necessidade de maior atenção no momento da consulta. É necessário, portanto, intensificar a educação no pré-natal. Assim, o profissional de saúde, principalmente o enfermeiro, deve estar atento às necessidades das gestantes.
Climatic drivers of pinyon mouse Peromyscus truei population dynamics in a resource‐restricted environment
Authors: Srivathsa Arjun , Tietje William , Rolland Virginie , Polyakov Anne , Oli Madan K.
Published: January 2019

Highly variable patterns in temperature and rainfall events can have pronounced consequences for small mammals in resource‐restricted environments. Climatic factors can therefore play a crucial role in determining the fates of small mammal populations. We applied Pradel's temporal symmetry model to a 21‐year capture–recapture dataset to study population dynamics of the pinyon mouse (Peromyscus truei) in a semi‐arid mixed oak woodland in California, USA. We examined time‐, season‐ and sex‐specific variation in realized population growth rate (λ) and its constituent vital rates, apparent survival and recruitment. We also tested the influence of climatic factors on these rates. Overall monthly apparent survival was 0.81 ± 0.004 (estimate ± SE). Survival was generally higher during wetter months (October–May) but varied over time. Monthly recruitment rate was 0.18 ± 0.01, ranging from 0.07 ± 0.01 to 0.63 ± 0.07. Although population growth rate (λ) was highly variable, overall monthly growth rate was close to 1.0, indicating a stable population during the study period (λ ± SE = 0.99 ± 0.01). Average temperature and its variability negatively affected survival, whereas rainfall positively influenced survival and recruitment rates, and thus the population growth rate. Our results suggest that seasonal rainfall and variation in temperature at the local scale, rather than regional climatic patterns, more strongly affected vital rates in this population. Discerning such linkages between species' population dynamics and environmental variability are critical for understanding local and regional impacts of global climate change, and for gauging viability and resilience of populations in resource‐restricted environments.
Markov chain analysis of sessile community dynamics in a degraded Philippine reef to support restoration of coral populations
Authors: Punongbayan Andalus T.
Published: January 2019

Quantitative approaches are needed for assessing assisted recovery potential in degraded coral reefs. A lagoonal community (Bolinao, Philippines) that has experienced severe disturbances (overfishing, blast fishing and coral bleaching) in the past was observed for 26 months. Benthic state sequences in 4 × 4 cm patches were used to quantify monthly probabilities of transitions between reef states. Benthic cover distribution was consistent with a spatially heterogeneous Markov process, with high variability in transition probabilities within a subset of four states: crustose algae with cropped turf, the codominant sponge Callyspongia samarensis, articulated coralline algae and fleshy macroalgae (MA). Once a patch is dominated by any of these states, there is high likelihood of cycling within the set before escaping to the rarer invertebrate groups. The assemblage is unlikely to recover naturally given prevailing conditions. Patches dominated by juvenile and adult corals have mean turnover times of about 3 and 5 months, respectively, due to (partial) mortality and competition. Asymmetry was detected for coral–macroalgal competition, despite low fleshy algal cover (9.5%), that was more adverse for coral juveniles than adults. While competition between coral and the mat‐forming C. samarensis was symmetrical, loss of coral cover through this path is relatively higher as a result of the higher interaction frequency. Articulated coralline algae do not appear as a constraint. Complementary strategies for assisted recovery were inferred from successional indices as well as the sensitivity of stationary coral cover to changes in transition probabilities. Results demonstrate that short‐term, fine‐scale observations of state variables can be used to resolve biotic constraints to inform restoration initiatives.
Synchronized expression of FLOWERING LOCUS T between branches underlies mass flowering in Fagus crenata
Authors: Satake Akiko , Kawatsu Kazutaka , Chiba Yukako , Kitamura Keiko , Han Qingmin
Published: January 2019

Masting is the intermittent and synchronized production of a large amount of flower and seed in plant populations. This population‐level phenomenon is caused by individual‐level variability in reproduction and its synchrony between individuals. The variability at the individual level is induced by synchronized reproduction between branches within an individual because a tree is an assemblage of branches that are considered as semiautonomous units. However, there have been no empirical studies that quantify the degree of reproductive synchrony at the branch level within the same tree in masting species. Here, we evaluated the reproductive synchrony within individuals by monitoring flowering dynamics and expression level of a flowering‐time gene at the branch‐level in a typical masting species, Fagus crenata Blume. The 4‐year census showed that the branch‐level gene expression was highly variable between years and was strongly synchronized between branches. The branch‐level synchrony in flowering‐time gene expression was followed by coherent flowering cycle at the whole individual. To examine the causal relationship between gene expression and climatic factors, we performed a nonlinear statistical analysis called convergent cross‐mapping using the time course data of gene expression and environmental variables. Our results indicated that the observed gene expression pattern was well cross‐mapped by temperature or precipitation. However, this cross‐mapping skill was lower than that of randomly generated seasonal dynamics, implying a combination of internal and external environmental signals is more likely to regulate gene expression dynamics in F. crenata. Our results provide the first empirical evidence that synchronized expression of a flowering‐time gene between branches underlies integrated flowering behavior at the individual level.
Observer design for neutral‐type neural networks with discrete and distributed time‐varying delays
Authors: Dong Yali , Chen Laijun , Mei Shengwei
Published: January 2019

This paper is concerned with the problem of state estimation for a class of neural networks with discrete and distributed interval time‐varying delays. We propose a new approach of nonlinear estimator design for the class of neutral‐type neural networks. By constructing a newly augmented Lyapunov‐Krasovskii functional, we establish sufficient conditions to guarantee the estimation error dynamics to be globally exponentially stable. The obtained results are formulated in terms of linear matrix inequalities (LMIs), which can be easily verified by the MATLAB LMI control toolbox. Then, the desired estimators gain matrix is characterized in terms of the solution to these LMIs. Three numerical examples are given to show the effectiveness of the proposed design method.
Territorial Robots
Authors: Young Liam
Published: January 2019

In satellite photography, individuals on Earth are too small to be visible, yet our impact through technology is plain to see. American artist Jenny Odell tells Guest‐ Editor Liam Young how she has been scouring satellite imagery for industrial landscapes that serve as portraits by proxy, underlining our reliance on the machines we have created.
Museum in the Countryside: Aesthetics of the Data Centre
Authors: Koolhaas Rem ,   OMA
Published: January 2019

As part of OMA's forthcoming exhibition ‘Countryside: Future of the World’, which opens at the Solomon R Guggenheim Museum in New York this autumn, the office is cataloguing the emergence of a new kind of architecture, the data centre. These vast, monolithic facilities are not designed to be inhabited by humans, but through their unimaginable scale and radical starkness they illicit the sensibilities of a new technological sublime. OMA founder Rem Koolhaas explores the ways through which architects might be able to engage this condition through cultural programmes and make it accessible to the people it would otherwise exclude.
Disciplinary Hybrids: Retail Landscapes of the Post‐Human City
Authors: Lyster Clare
Published: January 2019

What does the rise of automated retail mean for our future? Architect Clare Lyster, who is Associate Professor at the University of Illinois at Chicago, looks at its various emerging forms: cashierless grocery stores, low‐cost solar‐powered mobile retail units, self‐driving food delivery vehicles, walls of QR codes in public places … Rather than signalling a dystopian future of diminishing human interaction, she sees them as being in the lineage of work by visionary architects and urbanists from the 1960s such as Yona Friedman and Cedric Price, with the potential to increase urban equitability and empower remote communities.
‘I'm a Cloud of Infinitesimal Data Computation’ When Machines Talk Back: An interview with Deborah Harrison, one of the personality designers of Microsoft's Cortana AI
Authors: Young Liam
Published: January 2019

How is the personality of an artificial intelligence crafted, and what are the issues at stake? As one of the original architects of Microsoft's digital assistant Cortana's personality, Deborah Harrison knows the process inside out. In an interview with Guest‐Editor Liam Young, she examines the questions that creating this AI raised in terms of gender, culture and ethics, and considers the future of machine interactions. Wataru Sasaki, lead developer of the software behind the AI pop star Hatsune Miku, and android engineer Kohei Ogawa also join the discussion.
Influence of Pendant Group on Mobility of Organic Thin Film Transistor in Correlation with Reorganization Energy of Molecules
Authors: Patrikar Kalyani , Jain Nakul , Chakraborty Dwaipayan , Johari Priya , Rao Valipe Ramgopal , Kabra Dinesh
Published: January 2019

Charge transport properties of common donor copolymers in organic photovoltaics, poly({4,8‐bis[(2‐ethylhexyl)oxy]benzo[1,2‐b:4,5‐b′]dithiophene‐2,6‐diyl}{3‐fluoro‐2‐[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7) and poly([2,6′‐4,8‐di(5‐ethylhexylthienyl)benzo[1,2‐b;3,3‐b]dithiophene]{3‐fluoro‐2[(2‐ethylhexyl) carbonyl]thieno[3,4‐b]thiophenediyl}) (PTB7‐Th), with molecular structures differing only in the pendant group, are studied. This is the first report of field‐effect transistor mobility (µFET) of PTB7‐Th (0.14 cm2 V−1 s−1) and the highest µFET for PTB7 (0.01 cm2 V−1 s−1). µFET of PTB7‐Th is found to be almost one order of magnitude higher than PTB7. To understand the influence of molecular structure on charge transport, hole reorganization energy (λh) is calculated from first‐principles. λh of PTB7‐Th (≈150 meV) is found to be lower than PTB7 (≈346 meV). Further, the ratio of hopping rate versus square of charge transfer integral calculated from Marcus theory using λh for these systems is found to indicate a higher rate of hole transfer across dimers or homojunction interface for PTB7‐Th. These results are supplemented by experimentally determined λ using bulk‐heterojunction organic solar cells, where λPTB7‐Th≈200 meV and λPTB7≈310 meV follow a similar trend. The effective hole‐mobility estimation from BHJ devices correlates well with these λ values. This study provides understanding of charge transport properties via reorganization energy, as a function of pendant group without altering the backbone of the chains.
Pseudoelasticity of Metal Nanoparticles Is Caused by Their Ultrahigh Strength
Authors: Sharma Amit , Gazit Nimrod , Klinger Leonid , Rabkin Eugen
Published: January 2019

An assembly of hemispherical Ag nanoparticles is prepared by solid‐state dewetting of thin Ag film deposited on the sapphire substrate. The in situ nanomechanical compression testing of the particles with a flat diamond punch inside the scanning electron microscope demonstrates the deformation behavior typical for the nucleation‐controlled plasticity: high elastic deformation followed by an abrupt particles collapse. The latter is associated with the dislocations nucleation in otherwise pristine particle. The average contact pressure in the contact zone at the onset of dislocation‐controlled plasticity is about 8 GPa, and does not depend on particle size. This observation supports the hypothesis that the pseudoelasticity of much smaller Ag nanoparticles is intrinsically related to their ultrahigh strength. A stress‐induced diffusion along the particle–substrate and particle–punch interfaces is identified as a factor controlling the pseudoelastic deformation. The corresponding diffusion model allows estimating the room‐temperature self‐diffusion coefficient of Ag along the Ag–W and Ag–zirconia interfaces, which is quite close to the estimated value of the grain boundary self‐diffusion coefficient in Ag. Based on this finding, the map of pseudoelastic deformation of crystalline materials is proposed.
Designing Next‐Generation Local Drug Delivery Vehicles for Glioblastoma Adjuvant Chemotherapy: Lessons from the Clinic
Authors: Tabet Anthony , Jensen Melanie P. , Parkins Christopher C. , Patil Parag G. , Watts Colin , Scherman Oren A.
Published: January 2019

To date, the clinical outcomes and survival rates for patients with glioblastoma (GB) remain poor. A promising approach to disease‐modification involves local delivery of adjuvant chemotherapy into the resection cavity, thus circumventing the restrictions imposed by the blood–brain barrier. The clinical performance of the only FDA‐approved local therapy for GB [carmustine (BCNU)‐loaded polyanhydride wafers], however, has been disappointing. There is an unmet medical need in the local treatment of GB for drug delivery vehicles that provide sustained local release of small molecules and combination drugs over several months. Herein, key quantitative lessons from the use of local and systemic adjuvant chemotherapy for GB in the clinic are outlined, and it is discussed how these can inform the development of next‐generation therapies. Several recent approaches are highlighted, and it is proposed that long‐lasting soft materials can capture the value of stiff BCNU‐loaded wafers while addressing a number of unmet medical needs. Finally, it is suggested that improved communication between materials scientists, biomedical scientists, and clinicians may facilitate translation of these materials into the clinic and ultimately lead to improved clinical outcomes.
Simultaneous Production and Functionalization of Boron Nitride Nanosheets by Sugar‐Assisted Mechanochemical Exfoliation
Authors: Chen Shaohua , Xu Runzhang , Liu Jiaman , Zou Xiaolong , Qiu Ling , Kang Feiyu , Liu Bilu , Cheng Hui‐Ming
Published: January 2019

Due to their extraordinary properties, boron nitride nanosheets (BNNSs) have great promise for many applications. However, the difficulty of their efficient preparation and their poor dispersibility in liquids are the current factors that limit this. A simple yet efficient sugar‐assisted mechanochemical exfoliation (SAMCE) method is developed here to simultaneously achieve their exfoliation and functionalization. This method has a high actual exfoliation yield of 87.3%, and the resultant BNNSs are covalently grafted with sugar (sucrose) molecules, and are well dispersed in both water and organic liquids. A new mechanical force–induced exfoliation and chemical grafting mechanism is proposed based on experimental and density functional theory investigations. Thanks to the good dispersibility of the nanosheets, flexible and transparent BNNS/poly(vinyl alcohol) (PVA) composite films with multifunctionality is fabricated. Compared to pure PVA films, the composite films have a remarkably improved tensile strength and thermal dissipation capability. Noteworthy, they are flame retardant and can effectively block light from the deep blue to the UV region. This SAMCE production method has proven to be highly efficient, green, low cost, and scalable, and is extended to the exfoliation and functionalization of other two‐dimensional (2D) materials including MoS2, WS2, and graphite.
Bismuth Sulfide Nanorods with Retractable Zinc Protoporphyrin Molecules for Suppressing Innate Antioxidant Defense System and Strengthening Phototherapeutic Effects
Authors: Cheng Yan , Chang Yun , Feng Yanlin , Jian Hui , Wu Xiaqing , Zheng Runxiao , Xu Keqiang , Zhang Haiyuan
Published: January 2019

Bismuth (Bi)‐based nanomaterials (NMs) are widely used for computed tomography (CT) imaging guided photothermal therapy, however, the photodynamic property is hardly exhibited by these NMs due to the fast electron–hole recombination within their narrow bandgap. Herein, a sophisticated nanosystem is designed to endow bismuth sulfide (Bi2S3) nanorods (NRs) with potent photodynamic property. Zinc protoporphyrin IX (ZP) is linked to Bi2S3 NRs through a thermoresponsive polymer to form BPZP nanosystems. The stretching ZP could prebind to the active site of heme oxygenase‐1 overexpressed in cancer cells, suppressing the cellular antioxidant defense capability. Upon NIR laser irradiation, the heat released from Bi2S3 NRs could retract the polymer and drive ZP to the proximity of Bi2S3 NRs, facilitating an efficient electron–hole separation in ZP and Bi2S3 NRs, and leading to reactive oxygen species generation. In vitro and in vivo studies demonstrate the promising photodynamic property of BPZP, together with their photothermal and CT imaging performance.
Compositional Engineering for Thermally Stable, Highly Efficient Perovskite Solar Cells Exceeding 20% Power Conversion Efficiency with 85 °C/85% 1000 h Stability
Authors: Matsui Taisuke , Yamamoto Teruaki , Nishihara Takashi , Morisawa Ryosuke , Yokoyama Tomoyasu , Sekiguchi Takashi , Negami Takayuki
Published: January 2019

Perovskite solar cells have received great attention because of their rapid progress in efficiency, with a present certified highest efficiency of 23.3%. Achieving both high efficiency and high thermal stability is one of the biggest challenges currently limiting perovskite solar cells because devices displaying stability at high temperature frequently suffer from a marked decrease of efficiency. In this report, the relationship between perovskite composition and device thermal stability is examined. It is revealed that Rb can suppress the growth of PbI2 even under PbI2‐rich conditions and decreasing the Br ratio in the perovskite absorber layer can prevent the generation of unwanted RbBr‐based aggregations. The optimized device achieved by engineering perovskite composition exhibits 92% power conversion efficiency retention in a stress test conducted at 85 °C/85% relative humidity (RH) according to an international standard (IEC 61215) while exceeding 20% power conversion efficiency (certified efficiency of 20.8% at 1 cm2). These results reveal the great potential for the practical use of perovskite solar cells in the near future.
Suppressed Triplet Exciton Diffusion Due to Small Orbital Overlap as a Key Design Factor for Ultralong‐Lived Room‐Temperature Phosphorescence in Molecular Crystals
Authors: Narushima Kaishi , Kiyota Yasuhiro , Mori Takehiko , Hirata Shuzo , Vacha Martin
Published: January 2019

Persistent room‐temperature phosphorescence (RTP) under ambient conditions is attracting attention due to its strong potential for applications in bioimaging, sensing, or optical recording. Molecular packing leading to a rigid crystalline structure that minimizes nonradiative pathways from triplet state is often investigated for efficient RTP. However, for complex conjugated systems a key strategy to suppress the nonradiative deactivation is not found yet. Here, the origin of small rates of a nonradiative decay process from triplet states of conjugated molecular crystals showing RTP is reported. Optical microscopy analysis showed that, despite a favorable molecular stacking, an aromatic crystal with strong RTP is characterized by small diffusion length and small values of the diffusion coefficient of triplet excitons. Quantum chemical calculations reveal a large overlap between the lowest unoccupied molecular orbitals but very small overlap between the highest occupied molecular orbitals (HOMOs). Inefficient electron exchange caused by the small overlap of HOMOs prevents triplet excitons from diffusing over long distances and consequently from quenching at defect sites inside the crystal or at the crystal surface. These results will allow design of comprehensive molecular structures to obtain molecular solids with more efficient RTP.
Ab Initio Design of Graphene Block Enables Ultrasensitivity, Multimeter‐Like Range Switchable Pressure Sensor
Authors: Zang Xiaoling , Wang Xusheng , Xia Jiahao , Chai Yuqiao , Ma Xinlei , Li Rui , Ji Junhui , Xu Huaping , Xue Mianqi
Published: January 2019

In pursuit of the next‐generation pressure sensors, the fabrication of graphene‐based devices is considered to be one of the most promising approaches to address the unsatisfied sensitivity within a wide pressure range. Here, an ab initio design based on the graphene block is proposed to realize a high‐performance and multimeter‐like range switchable pressure sensor. The sensor contains three designed graphene‐based foams with different initial resistances, which enable continuous resistance‐change behavior induced by the pressure. Specifically, the reduced graphene oxide (rGO) foam–based sensor demonstrates a three times resistance change within the pressure range of 0–300 Pa, the rGO/polyurethane (rGO/PU) foam–based sensor presents a six times resistance change within the pressure range of 0.09–30 kPa, and the selenium‐functionalized rGO/PU (SFrGO/PU) foam–based sensor displays a resistance change of more than 1000‐fold within the pressure range of 1–72 kPa. Such different initial resistances and responses endow the device with controllable estimating pressure ranges, offering a switchable multimeter‐like function for various applications. This ab initio design, which is applicable to various 2D materials and operation modes, can provide a facile and feasible approach toward the next‐generation pressure sensors and other application fields related to 2D materials.
Palladium/Unichiral Ligand‐Catalyzed Decarboxylative Asymmetric Protonation of Racemic β‐Oxoallyl Esters
Authors: Muzart Jacques
Published: January 2019

The palladium‐catalyzed decarboxylative asymmetric protonation (DAP) of racemic allyl β‐keto esters using achiral protic species, first disclosed in 2006, is now a mature methodology for applications in asymmetric organic synthesis. In contrast, the mechanism of protonation remains unclear despite experimental and computational studies. The aim of this review is, firstly, to gather together the literature results, observations and proposals and, secondly, to suggest, for the enantioselectivity‐determining step, transition states depending on the substrate and the proton source.

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What makes a weed a weed? A large‐scale evaluation of arable weeds through a functional lens
Authors: Bourgeois Bérenger , Munoz François , Fried Guillaume , Mahaut Lucie , Armengot Laura , Denelle Pierre , Storkey Jonathan , Gaba Sabrina , Violle Cyrille
Published: January 2019

Premise of the Study

Despite long‐term research efforts, a comprehensive perspective on the ecological and functional properties determining plant weediness is still lacking. We investigated here key functional attributes of arable weeds compared to non‐weed plants, at large spatial scale.

Methods

We used an intensive survey of plant communities in cultivated and non‐cultivated habitats to define a pool of plants occurring in arable fields (weeds) and one of plants occurring only in open non‐arable habitats (non‐weeds) in France. We compared the two pools based on nine functional traits and three functional spaces (LHS, reproductive and resource requirement hypervolumes). Within the weed pool, we quantified the trait variation of weeds along a continuum of specialization to arable fields.

Key Results

Weeds were mostly therophytes and had higher specific leaf area, earlier and longer flowering, and higher affinity for nutrient‐rich, sunny and dry environments compared to non‐weeds, although functional spaces of weeds and non‐weeds largely overlapped. When fidelity to arable fields increased, the spectrum of weed ecological strategies decreased as did the overlap with non‐weeds, especially for the resource requirement hypervolume.

Conclusions

Arable weeds constitute a delimited pool defined by a trait syndrome providing tolerance to the ecological filters of arable fields (notably, regular soil disturbances and fertilization). The identification of such a syndrome is of great interest to predict the weedy potential of newly established alien plants. An important reservoir of plants may also become weeds after changes in agricultural practices, considering the large overlap between weeds and non‐weeds.
Heartbreak: A case of post‐infarction cardiogenic shock
Authors: Mukherjee Ashes , Fong Jason
Published: January 2019

Ventricular septal rupture is a rare but catastrophic complication of acute myocardial infarction. Although it has declined in incidence since the introduction of percutaneous coronary intervention, there hasn't been a significant change of mortality from the condition. In the chain of survival, prompt diagnosis and definitive surgery form the cardinal links. Prolonged medical management is not a feasible option as it is likely to be futile but the aim should be to reduce afterload with the help of intra‐aortic balloon pump or support with ventricular assist devices. Echocardiography sits at the heart of the diagnosis of this time critical condition and will guide accurate therapy and intervention. We present the first reported case from an Australian emergency department, where the echocardiography done by the emergency physician clinched the diagnosis. We emphasise here the paramountcy of emergency physicians being proficient in basic echocardiography to achieve rapid diagnosis. Once diagnosed it is critical to have an individual case‐tailored multi‐disciplinary discussion between emergency medicine, cardiothoracic surgery, cardiology and intensive care as to plan the optimal timing of surgery.
Information Theory for Fields
Authors: Enßlin Torsten A.
Published: January 2019

A physical field has an infinite number of degrees of freedom since it has a field value at each location of a continuous space. Therefore, it is impossible to know a field from finite measurements alone and prior information on the field is essential for field inference. An information theory for fields is needed to join the measurement and prior information into probabilistic statements on field configurations. Such an information field theory (IFT) is built upon the language of mathematical physics, in particular, on field theory and statistical mechanics. IFT permits the mathematical derivation of optimal imaging algorithms, data analysis methods, and even computer simulation schemes. The application of IFT algorithms to astronomical datasets provides high fidelity images of the Universe and facilitates the search for subtle statistical signals from the Big Bang. The concepts of IFT may even pave the road to novel computer simulations that are aware of their own uncertainties.
High‐Resolution Hydrogen Spectroscopy and The Proton Radius Puzzle
Authors: Thomas Simon , Fleurbaey Hélène , Galtier Sandrine , Julien Lucile , Biraben François , Nez François
Published: January 2019

High resolution spectroscopy of the hydrogen atom takes on particular importance in the new SI, as it allows to accurately determine fundamental constants, such as the Rydberg constant and the proton charge radius. Recently, the second most precisely measured transition frequency in hydrogen, , is obtained by our group. In the context of the Proton Radius Puzzle, this result calls for further investigation.
Proactively Reducing Anti‐Drug Antibodies via Immunomodulatory Bioconjugation
Authors: Zhang Peng , Jain Priyesh , Tsao Caroline , Wu Kan , Jiang Shaoyi
Published: January 2019

Although PEGylation reduces the immunogenicity of protein drugs to some extent, its limitations for highly immunogenic biotherapeutics have been demonstrated. Herein, a proactive strategy to alleviate the development of anti‐drug antibodies (ADAs) against protein drugs by immunomodulatory bioconjugation is reported. Rapamycin was conjugated to a PEGylated protein therapeutic via a cleavable disulfide linker. The conjugated rapamycin can be released from the bioconjugate and prevent immune responses once the bioconjugate is uptaken by antigen‐presenting cells. The immunomodulatory bioconjugate significantly reduced the titers of ADAs compared with a PEGylated protein. The inhibition of immune responses was specific to the conjugated antigen, avoiding systemic immune suppression and the risk of increased susceptibility to infections. The reported approach breaks the limitations of PEGylation by the proactive prevention of ADAs.
Electrocatalytic Volleyball: Rapid Nanoconfined Nicotinamide Cycling for Organic Synthesis in Electrode Pores
Authors: Megarity Clare F. , Siritanaratkul Bhavin , Heath Rachel S. , Wan Lei , Morello Giorgio , FitzPatrick Sarah R. , Booth Rosalind L. , Sills Adam J. , Robertson Alexander W. , Warner Jamie H. , Turner Nicholas J. , Armstrong Fraser A.
Published: January 2019

In living cells, redox chains rely on nanoconfinement using tiny enclosures, such as the mitochondrial matrix or chloroplast stroma, to concentrate enzymes and limit distances that nicotinamide cofactors and other metabolites must diffuse. In a chemical analogue exploiting this principle, nicotinamide adenine dinucleotide phosphate (NADPH) and NADP+ are cycled rapidly between ferredoxin–NADP+ reductase and a second enzyme—the pairs being juxtaposed within the 5–100 nm scale pores of an indium tin oxide electrode. The resulting electrode material, denoted (FNR+E2)@ITO/support, can drive and exploit a potentially large number of enzyme‐catalysed reactions.