bluuebunny/crossref_metadata_2025 huggingface dataset:
Métricas para análise de poder em redes sociais e sua aplicação nas doações de campanha para o Senado Federal brasileiro
Authors: Verona Letícia , Oliveira Jonice , Campos Maria Luiza Machado
Published: February 2020

A análise de quanto poder um ator tem sobre o outro é fundamental para entender a que interesses suas ações estão subordinadas. Este trabalho apresenta métricas para a análise fundamentado em bases teóricas da sociologia que refletem o desequilíbrio entre as relações, principal fonte de poder em uma rede social. Métricas que se aplicam ao relacionamento entre cada par de nós, e são calculadas em relação a toda a estrutura de poder da rede. Como instrumento de validação empírico foi feito estudo de caso com as doações eleitorais recebidas por partidos e senadores nas campanhas de 2010 e 2014. A aplicação das métricas permitiu evidenciar alguns interesses corporativos e partidários existentes hoje no Senado Federal brasileiro.
Investigação do protótipo IRATI usando testbed FIBRE
Authors: Lima Filho Djalma A. , Monteiro José A. Suruagy
Published: February 2020

Arquitetura da Internet apresenta limitações que interferem no seu desenvolvimento. RINA é uma proposta clean slate para a Internet do futuro que propõem soluções para resolver as limitações na estrutura da Internet, enquanto que o FIBRE é uma rede de experimentação que permite trabalhar com novas propostas de arquiteturas. Neste contexto, esse artigo descreve um trabalho com finalidade de investigar o controle de acesso na arquitetura RINA utilizando o protótipo do projeto IRATI sobre o ambiente FIBRE utilizando a ilha UFPE. Será abordado experimento realizado que visa avaliar de maneira prática o funcionamento do controle de acesso, além de apresentar soluções propostas pela arquitetura para solucionar as limitações atuais.
Geração Automática de Código para Aplicações Móveis Centradas em Dados Suportando Diferentes Infraestruturas de Nuvem
Authors: Kurtz Kellerson , Yamin Adenauer Correa , Brisolara Lisane B.
Published: February 2020

Este trabalho propõe uma abordagem orientada a modelos para a geração de código para aplicações centrada em dados na nuvem. A mesma baseia-se na modelagem da aplicação usando diagramas UML e define regras para modelar a interação da aplicação com a nuvem, visando torná-la independente da infraestrutura de nuvem adotada. Desta forma, a abordagem proposta permite o emprego de diferentes infraestruturas de nuvem sem exigir conhecimentos específicos de suas APIs, além de permitir fácil migração entre diferentes infraestruturas. Além disso, este artigo discute a integração da abordagem proposta em uma ferramenta de geração de código. Abordagem e automatização propostas são validadas através de um estudo de caso.
Um Middleware para Gerenciamento de Sensores de Saúde Corporais em Dispositivos Móveis
Authors: Ferrigo Samuel Francisco , da Costa Cristiano André , Righi Rodrigo da Rosa
Published: February 2020

O uso de sensores IoT para monitoramento de sinais vitais apresenta uma série de desafios, como a busca pela eficiência energética e a sincronização entre sensores. Uma solução para estes problemas é apresentada pelo modelo MOMICARE, um middleware para smartphones para gerenciamento de uma rede de sensores sem fio corporais com ênfase no consumo de energia e na sincronização dos dados enviados por esses sensores. Como contribuição científica, o MOMICARE oferece baixo consumo de energia e sincronismo entre os dados coletados pelos sensores. A avaliação do modelo foi realizada por meio de simulações efetuadas no software Cooja, apresentando redução no consumo de energia.
Uma Abordagem Dinâmica para Descoberta de Recursos na IoT Explorando Processamento Semântico
Authors: Dilli Renato , Filho Huberto , De Azevedo Maurício , Cavalheiro Gerson , Pernas Ana Marilza , Yamin Adenauer
Published: February 2020

A Internet das Coisas considera um cenário no qual recursos dinamicamente entram e saem do ambiente computacional. O procedimento de descoberta neste cenário, cuja quantidade de recursos é crescente, caracteriza um desafio de pesquisa em aberto. Este artigo apresenta o EXEHDA-RD, um serviço de descoberta de recursos integrado ao middleware EXEHDA que emprega tecnologias de Web Semântica e o padrão arquitetural REST. Os principais componentes da arquitetura foram implementados considerando características relevantes para IoT, tais como: controle de presença, auto-descoberta e aumento de expressividade nas consultas. Os resultados obtidos se mostram promissores e apontam para continuidade dos esforços de estudo e pesquisa.
Plataforma Web para acesso e disponibilização de dados climáticos
Authors: Mazzonetto Angela , Borella Felipe , Chitolina Pablo , Tochetto Guilherme , Casiraghi Jonatas , de Oliveira Fábio Augusto Antunes , Chan Chou Sin , Pavan Willingthon , Holbig Carlos Amaral
Published: February 2020

A previsão do tempo e clima são ferramentas muito importantes para tomada de decisão em diversas áreas como, por exemplo, na agricultura, na hidrologia e na geração de energia. A combinação de tecnologias modernas e a disponibilização de dados meteorológicos fornecem um mecanismo para aumentar a produtividade e minimizar riscos relacionados ao clima. Neste artigo é descrito o desenvolvimento de uma plataforma para automatizar o processo de requisição, de disponibilização e de visualização de dados gerados pelos modelos de previsão de mudanças climáticas do CPTEC/INPE.
Avaliação de Diferentes Arquiteturas de Redes Neurais Recorrentes na Previsão do Nível de Atividade de Abelhas
Authors: Gomes Pedro A. B. , de Carvalho Eduardo C. , Arruda Helder M. , de Souza Paulo , Pessin Gustavo
Published: February 2020

Um terço dos alimentos consumidos pela humanidade são provenientes da ação das abelhas. Estes insetos também são fundamentais para a reprodução das plantas e estão desaparecendo do planeta. Um entendimento sobre o seu comportamento, aqui abordado sobre o ponto de vista do seu nível de atividade, pode ajudar a detectar situações adversas e até potencializar o uso das abelhas em culturas. Frente a isso, neste trabalho são avaliadas seis arquiteturas de Redes Neurais Recorrentes, alternando topologia e estruturas GRU e LSTM, para prever o nível de atividade de abelhas baseado nos valores de níveis passados. Mostra-se também como o modelo com menor erro é melhorado quando treinado com mais informações de níveis anteriores.
AGILITY SCRUM - Um Jogo para Ensino da Metodologia SCRUM
Authors: de Castro Ronney Moreira , Siqueira Sean Wolfgand Matsui , de Almeida Denilson Novais , Nascimento Felipe Calegario
Published: February 2020

Tendo em vista as dificuldades encontradas por docentes e discentes no ensino e no aprendizado da Metodologia Ágil Scrum como prática de Engenharia de Software, este artigo descreve uma abordagem diferente. A partir da criação de um jogo não computacional, os discentes puderam vivenciar uma experiência prática do uso da metodologia, o que por sua vez trouxe uma melhor aceitação, assimilação e resultado nos exercícios e trabalhos realizados, indicando assim um bom aproveitamento e eficácia na aplicação do conteúdo proposto pelos docentes.
Gamificação para o Ensino de Computação na Educação Básica
Authors: Brum Michel Girotto , da Cruz Marcia E. J. Kniphoff
Published: February 2020

O ensino de Computação no Brasil vem sendo incentivado com atividades pontuais, mas necessita de fomento para sua consolidação. Para contribuir com essa proposta este relato de experiência apresenta resultados de atividades realizadas em disciplina facultativa de Robótica, em escola de educação básica. Considerando que a Robótica possibilita a introdução de conteúdos da Computação e que os estudantes são nativos digitais, empregou-se a gamificação que consiste em utilizar os princípios de game design à metodologia de ensino. Os resultados apresentaram melhora significativa no aprendizado do conteúdo trabalhado na disciplina e ampliação de habilidades sociais.
Motivação de Estudantes Non-Majors em uma Disciplina de Programação
Authors: Santana Bianca L. , Figuerêdo José Solenir L. , Bittencourt Roberto A.
Published: February 2020

A motivação tem um papel importante no processo de aprendizagem dos estudantes, podendo ajudá-los a enfrentar dificuldades. Neste estudo, investigamos como uma abordagem de ensino de programação para non-majors, que faz uso do ambiente Scratch, da linguagem de programação Python com a biblioteca Turtle e com o ambiente de desenvolvimento JES, influencia na motivação dos estudantes. Verificamos que o Scratch contribuiu para a motivação dos estudantes, enquanto que o JES não mostrou o mesmo desempenho. Além disso, destacamos, a partir de um modelo de motivação, um conjunto de variáveis que podem despertar, manter ou diminuir a motivação.
5 Minutos de Programação em Exibições
Authors: von Wangenheim Christiane Gresse , von Wangenheim Aldo , Pacheco Fernando S. , Ferreira M. Nathalie F. , Hauck Jean C. R.
Published: February 2020

Para popularizar a computação de maneira lúdica em feiras científicas, criamos um estande para desmistificar a computação física e, ao mesmo tempo, motivar e estimular o interesse pela computação. Foram projetados dois robôs programáveis interativos, em forma de minion (um deles com mais de um metro de altura). Com ambos, pode-se mostrar como é fácil e interessante criar programas em poucos minutos utilizando uma linguagem visual como Scratch 2 ou Snap!. O hardware consiste em uma placa microcontrolada Arduino Nano e um conjunto de sensores e atuadores. A experiência na SEPEX 2015, com mais de 4 mil visitantes, mostra que a oferta de tais estandes ao público em geral pode ser uma alternativa envolvente para popularizar a computação com um custo baixo.
Contribuições da Extensão Universitária na formação social, acadêmica e profissional dos estudantes de Computação
Authors: dos Santos Juliana Maria Oliveira , Souza Cíntia Mercês , Santos Taiala Almeida , Alves Pietro Matheus Bompet Fontoura , Santos Débora Abdalla
Published: February 2020

A extensão, um dos pilares da Universidade, contribui para operacionalizar a relação transformadora entre Universidade e Sociedade. A Ação Curricular em Comunidade e em Sociedade (ACCS) vem cumprindo este papel, desenvolvendo ações de extensão, promovendo o intercâmbio, a reelaboração e a produção de conhecimento sobre a computação e sociedade. Este artigo apresenta as metodologias utilizadas para o desenvolvimento da ACCS: Onda Solidária de Inclusão Digital - Tecnologia a Serviço da Cidadania, bem como discute os impactos desta ação na formação social, acadêmica e profissional do estudante de ensino superior na área de computação.
A Utilização do Scratch como Ferramenta no Ensino de Pensamento Computacional para Crianças
Authors: Aono Alexandre Hild , Rody Hugo Vianna Silva , Musa Daniela Leal , Pereira Vanessa Andrade , Almeida Jurandy
Published: February 2020

Este artigo apresenta uma iniciativa de ensino de pensamento computacional para estudantes de uma escola de ensino fundamental com a utilização de uma metodologia expositiva aliada à utilização do Scratch como um ambiente de aprendizado intuitivo e acessível. O método de aula adotado consistiu em uma explicação teórica sobre um tópico relacionado à aquisição de pensamento computacional seguida de atividades práticas de programação nas quais os alunos construíram partes de um jogo que posteriormente foram reunidas em um projeto final. Este experimento permitiu avaliar metodologias para ensino de programação e utilização de games como ferramenta para incentivo pedagógico na área.
Oficina de Re(design) da Interação do Whatsapp para alunas da rede municipal de Petrópolis
Authors: Salgado Luciana , Cappelli Claudia , Avelino Meirylene Rosa Emidio
Published: February 2020

O Programa Meninas Digitais quer atrair meninas para a área de computação. Este trabalho apresenta a execução de uma oficina no LNCC (Laboratório Nacional de Ciência da Computação) em Petrópolis, Rio de Janeiro, para duas turmas de ensino fundamental de escola pública. Após uma palestra sobre o Projeto, conduzimos uma oficina para o (re)Projeto da Interação Humano Computador, em um cenário de desenvolvimento de software, onde os alunos teriam que entender o cliente e apresentar soluções possíveis para os problemas apresentados.
Construção identitária das mulheres no campo da computação. Imagens reforçadas, distâncias ampliadas
Authors: Castelini Pricila , Amaral Marília Abrahão
Published: February 2020

Este artigo analisa, com base em Análise de Discurso, as identidades construídas das mulheres na divulgação do Programaê. O Programaê divulga imagens que constroem discursivamente representações de estilos e identidades formadas socialmente, culturalmente e historicamente que reforçam os binarismos homem/mulher, masculino/feminino. Nessa perspectiva teórica, são apresentadas três imagens do corpus (N=50) para destacar a reprodução e reforço dos binarismos da computação.
Uma Pesquisa com Alunas do Ensino Fundamental e Médio sobre os Cursos da Área de Computação
Authors: de Holanda Maristela Terto , Mourão Roberto , Ramos Guilherme N. , de Araújo Aleteia Patrícia F. , Walter Maria Emília T.
Published: February 2020

Este artigo apresenta dados coletados pelo Projeto Meninas.comp sobre a percepção das meninas do ensino fundamental e médio em Brasília em relação ao curso de Ciência da Computação. A pesquisa foi aplicada durante os anos de 2011, 2012, 2013 e 2014 por meio de um formulário em papel durante a Semana Nacional de Ciência e Tecnologia (SNCT). A partir dessa coleta composta de 3.707 respondentes, foram realizadas análises com o programa R, e algumas discussões sobre a importância da família e o interesse por Comuptação por nível escolar são apresentados.
Alocação de Recursos em Funções de Redes Virtualizadas: Desafios e Perspectivas Aplicado em Data enter
Authors: Souza Rafael , Santos Marcelo , Fernandes Stênio
Published: February 2020

A implementação de uma Network Function Virtualization (NFV) denota uma mudança generalizada nos serviços de comunicação e rede de uma rede de provedores de serviços para uma rede baseada em nuvem. Seu uso tem o potencial de fornecer serviços de rede baseados em nuvem com menores custos operacionais e de capital. Neste contexto, este trabalho visa identificar e discutir aplicações de NFV em arquiteturas de data center. Este estudo realiza uma revisão da literatura, para levantar as principais pesquisas sobre alocação de recurso de NFV no data center. A partir dessa pesquisa, foi identificado evidências sobre os problemas e soluções associadas a alocação de recursos de NFV em data centers. Finalmente, identificamos lacunas, desafios abertos que podem ser usadas para direcionar pesquisa futura.
1917, cien años después. Aurora, cénit y ocaso del comunismo ruso
Authors: Vidal Castaño José Antonio
Published: February 2020

La revolución bolchevique de 1917 cambió radicalmente el rumbo de la vida en buena parte del planeta, a expensas de la Gran Guerra europea y la determinación de sus dirigentes. El artículo narra los acontecimientos y las fases de este experimento sociopolítico y cultural que ha durado setenta años. Cien años después, pretende reabrir la reflexión, contando con el impacto que produjo en la política y las ideas en España y su influencia en la historia del presente.
Entre la ortodoxia y la revolución: Schumpeter y Keynes
Authors: García Monerris Carmen
Published: February 2020

Tal vez, Joseph Alois Schumpeter y John Maynard Keynes fueron los economistas que mejor diagnosticaron la naturaleza de los nuevos cambios del capitalismo. ¿Cambios? ¿Qué cambios? ¿Cuándo? A finales del siglo XIX. En este texto se repasan sus principales contribuciones. En el contexto de la crisis, la profunda crisis de la modernidad más reciente. En este artículo se examina y se revisa su distinto compromiso, su compromiso con la realidad política. Sus propuestas fueron no solo un ataque contra la ortodoxia heredada, sino también una alternativa razonable y razonada a la revolución.
Dullard-mediated Smad1/5/8 inhibition controls mouse cardiac neural crest cells condensation and outflow tract septation
Authors: Darrigrand Jean-François , Valente Mariana , Comai Glenda , Martinez Pauline , Petit Maxime , Nishinakamura Ryuichi , Osorio Daniel S , Renault Gilles , Marchiol Carmen , Ribes Vanessa , Cadot Bruno
Published: February 2020

The establishment of separated pulmonary and systemic circulation in vertebrates, via cardiac outflow tract (OFT) septation, is a sensitive developmental process accounting for 10% of all congenital anomalies. Neural Crest Cells (NCC) colonising the heart condensate along the primitive endocardial tube and force its scission into two tubes. Here, we show that NCC aggregation progressively decreases along the OFT distal-proximal axis following a BMP signalling gradient. Dullard, a nuclear phosphatase, tunes the BMP gradient amplitude and prevents NCC premature condensation. Dullard maintains transcriptional programs providing NCC with mesenchymal traits. It attenuates the expression of the aggregation factor Sema3c and conversely promotes that of the epithelial-mesenchymal transition driver Twist1. Altogether, Dullard-mediated fine-tuning of BMP signalling ensures the timed and progressive zipper-like closure of the OFT by the NCC and prevents the formation of a heart carrying the congenital abnormalities defining the tetralogy of Fallot.
Wicked problems, wicked play
Authors: Perera Dulmini
Published: February 2020

Design methods need to reconsider ways to avoid othering messiness (or what appears to be contradictory or nonsensical) within wicked problem situations, particularly crisis sites. As such, this paper suggests that play frames (defined as Fun Machines) can be utilised as situated strategies that designers can apply to address paradoxes and contradictions. The paper presents the theoretical framework for a Fun Machine by focusing on second-generation design methods and how they facilitate conversation, while simultaneously exploring an often-neglected playful aspect of conversation that is usually found in fun-making. The applications of a Fun Machine are discussed in the historical context (Cedric Price’s Fun Palace) and with a pilot project conducted at a contemporary crisis site (Dessau).
Effects of Malting on Nutritional Characteristics of Pigeon Pea (Cajanus cajan)
Authors: Asouzu A. I. , Umerah N. N.
Published: February 2020

Background/Objective: Malting is a process that is not expensive and is technologically effective in improving the nutritional quality of food. The objective of this study was to determine the effect of malting on the nutritional characteristics of pigeon pea (Cajanus cajan).

Materials and Methods: The pigeon pea seeds were sorted and washed. The seeds were then steeped in water at 29°C for 24 hours. Changing of water at 6 hours interval was observed during steeping. The resultant steeped seeds were spread on jute bag and were covered with white cotton cloth to germinate for 72 hours. The sprouted seeds were oven dried at a temperature of 50°C for 1 hour and thereafter, the plumules were separated from the seed and the malted seeds were dried and milled into flour. Both the raw and malted samples were subjected to laboratory analysis for proximate, mineral element composition, anti-nutrients and functional properties. The results were determined in triplicate and subjected to statistical analysis using SPSS version 20.

Results: The result of the proximate analysis showed that the samples were generally low in moisture which are 12.81±0.07 and 15.10±0.81%, protein content are 19.01±0.08 and 22.10±0.16%, Ash content are 2.27±0.23 and 3.18±0.47%, Fat content are 1.02±0.32 and 1.68±0.81%, fibre content are 0.45±0.52 and 1.23±0.63%, carbohydrate are 57.37±0.28 and 63.78±0.01% and energy were 300.32 and 326.20 Kcal/100 g for raw and malted sample respectively. The result of minerals are iron 0.13±0.12 and 1.03±0.08 mg/100 g, magnesium 50.30±0.01 and 68.24±0.45 mg/100 g, zinc 0.27±0.21 an 0.88±0.32 mg/100 g, phosphorus 13.10±0.57 and 18.30±0.32 mg/100 g, potassium 2.10±0.62 and 4.50±0.08 mg/100 g, sodium 6.10±0.31 and 9.33±0.07 mg/100 g and calcium 7.28±0.41 and 10.11±0.22 mg/100 g for raw and malted sample respectively. The anti-nutrients determined are phytate 19.86±0.03 and 7.22±0.78 mg/100 g, oxalate 1.78±0.03 and 0.02±0.42 mg/100 g, trypsin inhibitor 40.53±0.42 and 10.30 m±0.07 g/100 g, tannins 28.80±0.50 and 9.12±0.18 mg/100 g and hydrogen cyanide 1.63±0.68 and 0.68±0.04 mg/100 g, for the raw and malted pigeon pea respectively. The functional properties are Bulk density 0.62±0.81 and 0.98±0.01 g/cm3, water absorption capacity 227.05±0.24 and 261.220.38%, oil absorption capacity 162.72±0.11 and 170.54%±0.42, foaming capacity 18.80±0.28 and 37.73±0.21% and swelling capacity 4.08±0.13 and 6.24±0.31%.

Conclusion: It was observed that highly nutritious flour can be produced from pigeon pea using malting.
Impact of Reject of Dairy Wastewater into the Aquatic Environment: Case of the Bayo Dairy Company (Brazzaville-Congo)
Authors: Litébé A. C. , Ngakegni-Limbili C. A. , Mvouezolo R. F. Louzayadio , Loupangou C. Nkounkou , Nzobadila D. , Ouamba J. M.
Published: February 2020

The development of industrial activities is the source of the production of large quantities of wastewater. The last-mentioned are rejected in the environment often without any prior treatment and have serious short-term and sometimes long-term environmental consequences. The objective of this work is to assess the environmental impacts and to propose a process for treating wastewater of reject from Bayo dairy in Brazzaville-Congo. The samples were taken at four (4) stations before, during and after production of dairy products. Multivariate statistical analysis of the physicochemical data was carried out using Statistica 7.1 software. The results obtained show that the wastewater from the Bayo dairy has a basic pH which fluctuates between 8.32 and 9.17 with standard temperatures of reject. The salinity of the wastewater increases greatly during production, which shows rising mineralization. The contents of MES (49.78-181.80 mg/L), MO (40.23-72.64 mg O2/L), COD (51.08-98.91 mg O2/L), BOD5 (34.80-59.50 mg O2/L) and the turbidity (26-179) NTU are moderately high and reflect an increase pollutant load before, during and after production of dairy products in stations S2 and S3. The COD/BOD5 ratio reveals that the Bayo dairy wastewater is moderately biodegradable before, during and after production with a biodegradability coefficient which varies between 1.40 and 1.78. The ACP approves possible industrial pollution from wastewater from the Bayo dairy and reports on the impact of the rejects in the environment. Thus, this study is a contribution to raising awareness among the Congolese population and decision-makers on the quality of wastewater rejected by local industries.
Impact of Laser Treatment on Hydrogenated Amorphous Silicon Properties
Authors: Maurer Claudia , Beyer Wolfhard , Hülsbeck Markus , Breuer Uwe , Rau Uwe , Haas Stefan
Published: February 2020

Herein, the application of laser radiation to locally modify the hydrogen distribution within hydrogenated amorphous silicon films on a short time scale is studied. The impact of laser power and irradiation time on the temperature of the silicon layer during the laser treatment and the hydrogen outdiffusion is analyzed. Moreover, the resulting optoelectronic properties of the amorphous silicon are examined. On a timescale of a few seconds or less, the hydrogen concentration in the near‐surface region of the silicon layer can be successfully decreased without major impact on the optoelectronic properties.
Gallium‐ and Cerium‐Doped Phosphate Glasses with Antibacterial Properties for Medical Applications
Authors: Łapa Agata , Cresswell Mark , Campbell Ian , Jackson Phil , Goldmann Wolfgang H. , Detsch Rainer , Boccaccini Aldo R.
Published: February 2020

Novel cerium‐ (Ce) and gallium (Ga)‐doped phosphate glasses (PGs) are successfully obtained by the peroxidation method. The new glasses are characterized using Fourier‐transform infrared spectroscopy (FTIR), Raman spectroscopy, X‐ray diffraction, inductively coupled plasma‐optical emission spectroscopy (ICP‐OES), and pH measurements. A strong correlation between glass properties and their composition is found. The incorporation of Ga/Ce in the glass structure is confirmed by peak shifts in Raman and FTIR spectra. Degradation tests conducted in water confirm the soluble character of the PGs and reveal the influence of Ga and Ce on the degradation rate. Ga‐doped glasses are found to be less soluble than Ce‐doped ones (43%, 33%, 21%, and 16% of dry mass remained after 7 weeks for 7Ga, 5Ga, 5Ce, and 7Ce, respectively). Biological evaluation using ST‐2 cells shows adequate cell response with a cell viability of 80% measured using the indirect contact method depending on the composition. The cell viability decreases with an increase in Ga content and increases with Ce content. The antibacterial character of Ga/Ce‐doped PGs is confirmed by turbidity measurements against Escherichia coli and Staphylococcus carnosus. The novel Ce/Ga‐doped PGs exhibiting antibacterial properties and biocompatibility reported here are interesting for tissue engineering and wound healing applications.
Wavelength‐Dependent Stiffening of Hydrogel Matrices via Redshifted [2+2] Photocycloadditions
Authors: Kalayci Kubra , Frisch Hendrik , Barner‐Kowollik Christopher , Truong Vinh X.
Published: February 2020

Hydrogels with on‐demand tunable mechanical properties within sensitive biological environments are of critical importance for examining cellular responses to cell culture platforms. Herein, the first bio‐orthogonal hydrogel that can be formed and subsequently tuned in its mechanical properties by simply switching different wavelengths of visible light (i.e., 455 and 420 nm) is reported. Specifically, both the initial hydrogelation and the tuning of the mechanical properties can be fully decoupled and selectively initiated by different colors of light. Sparing the need for any catalysts, the development of such a dual wavelength selective hydrogel for biological applications spans four levels: First, the development of the until today most redshifted photocycloaddition to allow for the selective initiation of only one photoreaction; second, the investigation of its wavelength‐dependent ligation efficiency; third, translation of the ligation chemistry into a hydrogelator, and fourth, establishing a biocompatible hydrogel platform for applications in biomaterials engineering including detachment of fibroblasts from 2D culture areas or primary 3D culture of human mesenchymal stem cells. The introduced platform technology enables the fabrication of a hydrogel of predefined mechanical properties exclusively with visible light.
Nanogap Plasmonic Structures Fabricated by Switchable Capillary‐Force Driven Self‐Assembly for Localized Sensing of Anticancer Medicines with Microfluidic SERS
Authors: Lao Zhaoxin , Zheng Yuanyuan , Dai Yichuan , Hu Yanlei , Ni Jincheng , Ji Shengyun , Cai Ze , Smith Zachary J. , Li Jiawen , Zhang Li , Wu Dong , Chu Jiaru
Published: February 2020

Nanogap plasmonic structures, which can strongly enhance electromagnetic fields, enable widespread applications in surface‐enhanced Raman spectroscopy (SERS) sensing. Although the directed self‐assembly strategy has been adopted for the fabrication of micro/nanostructures on open surfaces, fabrication of nanogap plasmonic structures on complex substrates or at designated locations still remains a grand challenge. Here, a switchable self‐assembly method is developed to manufacture 3D nanogap plasmonic structures by combining supercritical drying and capillary‐force driven self‐assembly (CFSA) of micropillars fabricated by laser printing. The polymer pillars can stay upright during solvent development via supercritical drying, and then can form the nanogap after metal coating and subsequent CFSA. Due to the excellent flexibility of this method, diverse patterned plasmonic nanogap structures can be fabricated on planar or nonplanar substrates for SERS. The measured SERS signals of different patterned nanogaps in fluidic environment show a maximum enhancement factor ≈8 × 107. Such nanostructures in microchannels also allow localized sensing for anticancer drugs (doxorubicin). Resulting from the marriage of top‐down and self‐assembly techniques, this method provides a facile, effective, and controllable approach for creating nanogap enabled SERS devices in fluidic channels, and hence can advance applications in precision medicine.
Plasmonic‐Assisted Graphene Oxide Films with Enhanced Photothermal Actuation for Soft Robots
Authors: Yang Yuanyuan , Liu Yanting , Shen Yajing
Published: February 2020

Carbon‐based materials are widely used as light‐driven soft actuators relying on their thermal desorption or expansion. However, applying a passive layer in such film construction greatly limits the actuating efficiency, e.g., bending amplitude and speed. In this work, a dual active layer strengthened bilayer composite film made of graphene oxide (GO)–polydopamine (PDA)–gold nanoparticles (Au NPs)/polydimethylsiloxane (PDMS) is developed. In this film, the conventional passive layer is replaced by another AuNPs‐enhanced thermal responsive layer. When applying NIR light exposure, the whole film deforms controllably resulting from the water loss in the GO–PDA–Au NPs layer and thermal expansion in the PDMS layer. Benefiting from the dual active bilayer mechanism, the thin film's actuating efficiency is dramatically improved compared with that of conventional methods. Specifically, the bending amplitude is enhanced up to 173%, and the actuating speed is improved to 3.5‐fold. The soft actuator can act as an artificial arm with high actuating strength and can be used as a wireless gripper. Moreover, the film can be designed as soft robots with various locomotion modes including linear, rolling, and steering motions. The developed composite film offers new opportunities for biomimetic soft robotics as well as future applications.
Rafting‐Enabled Recovery Avoids Recrystallization in 3D‐Printing‐Repaired Single‐Crystal Superalloys
Authors: Chen Kai , Huang Runqiu , Li Yao , Lin Sicong , Zhu Wenxin , Tamura Nobumichi , Li Ju , Shan Zhi‐Wei , Ma Evan
Published: February 2020

The repair of damaged Ni‐based superalloy single‐crystal turbine blades has been a long‐standing challenge. Additive manufacturing by an electron beam is promising to this end, but there is a formidable obstacle: either the residual stress and γ/γ  ′ microstructure in the single‐crystalline fusion zone after e‐beam melting are unacceptable (e.g., prone to cracking), or, after solutionizing heat treatment, recrystallization occurs, bringing forth new grains that degrade the high‐temperature creep properties. Here, a post‐3D printing recovery protocol is designed that eliminates the driving force for recrystallization, namely, the stored energy associated with the high retained dislocation density, prior to standard solution treatment and aging. The post‐electron‐beam‐melting, pre‐solutionizing recovery via sub‐solvus annealing is rendered possible by the rafting (i.e., directional coarsening) of γ  ′ particles that facilitates dislocation rearrangement and annihilation. The rafted microstructure is removed in subsequent solution treatment, leaving behind a damage‐free and residual‐stress‐free single crystal with uniform γ  ′ precipitates indistinguishable from the rest of the turbine blade. This discovery offers a practical means to keep 3D‐printed single crystals from cracking due to unrelieved residual stress, or stress‐relieved but recrystallizing into a polycrystalline microstructure, paving the way for additive manufacturing to repair, restore, and reshape any superalloy single‐crystal product.
Inhibiting Random Droplet Motion on Hot Surfaces by Engineering Symmetry‐Breaking Janus‐Mushroom Structure
Authors: Liu Minjie , Li Jing , Zhou Xiaofeng , Li Jiaqian , Feng Shile , Cheng Yaqi , Wang Steven , Wang Zuankai
Published: February 2020

Concentrating impacting droplets onto a localized hotspot and inducing them to remain in a preferential heat transfer mode is essential for efficient thermal management such as spray cooling. Conventionally, droplets impacting on hot surfaces can randomly bounce off without becoming fully evaporated, resulting in low heat transfer efficiency. Although the directional and guided transport of impacting droplets to a preferential location can be achieved through the introduction of a structural gradient, the manifestation of such a motion requires the meticulous control of the spatial location where the droplet is released. Here, a novel surface consisting of regularly patterned posts with Janus‐mushroom structure (JMS) is designed, in which the sidewalls of the individual posts are decorated with straight and curved morphologies. It is revealed that such structural symmetry‐breaking in the individual posts leads to directional liquid penetration and vapor flow toward the straight sidewall, and also reduces the work of adhesion, altogether triggering collective and preferential droplet transport at a high temperature. By surrounding a conventional surface with JMS endowed with favorable directionality, it is possible to concentrate small impacting droplets preferentially onto a localized hotspot to achieve enhanced cooling efficiency.
FIB‐Patterned Nano‐Supercapacitors: Minimized Size with Ultrahigh Performances
Authors: Zhuang Peiyuan , Sun Yangye , Li Lei , Chee Mason Oliver Lam , Dong Pei , Pei Liyuan , Chu Hang , Sun Zhengzong , Shen Jianfeng , Ye Mingxin , Ajayan Pulickel M.
Published: February 2020

Advances in microelectronic system technology have necessitated the development and miniaturization of energy storage devices. Supercapacitors are an important complement to batteries in microelectronic systems; and further reduction of the size of micro‐supercapacitors is challenging. Here, a novel strategy is demonstrated to break through the resolution limit of micro‐supercapacitors by preparing nano‐supercapacitors (NSCs) with interdigital nanosized electrodes using focused ion beam technology. The minimization of the size of the NSCs leads to a large increase in capacitance, with a high areal capacitance of 9.52 mF cm−2 and a volumetric capacitance of 18 700 F cm−3, far superior to those of other reported works. Size reduction and the narrowing of the physical separation between nanoelectrodes are proved to be the most crucial factors in the enhancement of capacitive performances. New charge‐storage mechanisms are discovered with a remarkable nonfaradaic double‐layer capacitance that exists due to the considerable inner electric field force at the nanoscale. The developed strategy and the first set of data provided here shed light on the design and fabrication of flexible interdigitated NSCs that rival state‐of‐the‐art supercapacitors in performance.
Biocompatible Janus Membrane with Double Self‐Healing Ability for Intelligent Anticorrosion
Authors: Cui Han‐Rui , Wang Chun‐Lei , Bi Yan‐Ze , Zhao Jian‐Liang , Dong Zhen‐Zhen , Wang Yan‐Dong , Li Yan , Wang Cai‐Qi
Published: February 2020

Biocompatible Janus composite membrane with double self‐repairing ability is constructed on the surface of magnesium, using paeonol‐doped poly(ε‐caprolactone) (P@PCL) as a hydrophobic layer and imide‐bond‐based chitosan hydrogel (PGD) as a hydrophilic layer. A copper mesh is used as the base to indirectly study this specific ability of the as‐prepared Janus membrane. The water contact angle of the Janus copper mesh‐P@PCL‐PGD with the hydrophobic layer at the bottom and the hydrophilic layer at the top is 65°, and its water retention height reached 5.1 cm, showing the strongest prevention capacity of water infiltration. Further, the damage of the hydrophobic layer is repaired by the corrosion inhibitor and the magnesium ion complex membrane; the hydrophilic layer is healed by the quick response of the imine bond in the gel to the pH change. Among all samples, the weight loss rate of Mg‐P@PCL‐PGD is found to be the smallest—only 1.19% after 12 d and 5.20% after 21 d. In short, effective protection of magnesium is achieved which is conducive to cell adhesion and proliferation, through systematically summarizing the synergy between Janus membrane and dual self‐repair. The related results are distinctive and will open up new research directions for corrosion protection of metals.
Synthesis of Benzo[b]thiophenes through Rhodium‐Catalyzed Three‐Component Reaction using Elemental Sulfur
Authors: Moon Sanghun , Kato Moena , Nishii Yuji , Miura Masahiro
Published: February 2020

A benzo[b]thiophene synthesis by Rh‐catalyzed three‐component coupling reaction of arylboronic acids, alkynes, and elemental sulfur (S8) is developed. A notable feature of this protocol is that the thienannulation (thiophene annulation) proceeds with high regioselectivity via the sequential alkyne insertion, C−H activation, and then sulfur atom transfer to the metallacycle intermediate. In a similar manner, dibenzothiophenes can be synthesized from the parent biarylboronic acids and S8.

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Combinations of rolling, mineral oil, sulfur, and phosphorous acid affect Microdochium patch severity
Authors: Mattox Clint M. , Kowalewski Alec R. , McDonald Brian W. , Lambrinos John G. , Pscheidt Jay W.
Published: February 2020

Microdochium patch is a turfgrass disease that occurs in cool, humid regions caused by the fungal pathogen Microdochium nivale (Fr.) Samuels & Hallett [Teleomorph = Monographella nivalis (Schaffnit) E. Müll]. Fungicide applications are the predominant method of control; however, pesticide restrictions have generated concern regarding the use of traditional chemicals to manage turfgrass pests. The objective of this research was to evaluate the effects of the cultural practice of rolling in combination with applications of mineral oil, S, and/or phosphorous acid (H3PO3) on the suppression of Microdochium patch on an annual bluegrass (Poa annua L.) putting green. A 2‐yr field trial took place from September 2013 to June 2014 and was repeated from September 2014 to June 2015 on a sand‐based annual bluegrass putting green in Corvallis, OR. Experimental design was a 2 × 4 × 2 × 2 randomized complete split‐plot design with four replications. Factors included rolling, the fertility products S and H3PO3 applied alone and in combination, mineral oil treatment, and year. Mineral oil suppressed Microdochium patch although applications led to turfgrass thinning. The combination of S and H3PO3 provided greater Microdochium patch disease suppression compared to applying either alone. Rolling also suppressed Microdochium patch in the second year of this study. Further research to determine how to best utilize these combined cultural practices to manage Microdochium patch is warranted.
Congenital cataracts – Clinical considerations in ultrasound diagnosis and management
Authors: Thayalan Krishanthy , Kothari Anoushka , Khanna Yash , Kothari Alka
Published: February 2020

Paediatric cataracts are one of the more common ocular abnormalities that occur in approximately 6 in 10,000 infants and are a major cause of childhood blindness. A suggested pathological mechanism for congenital cataract formation is the abnormal arrangement of lens fibres during embryogenesis. While toxins, chromosomal abnormalities, infections and metabolic disorders account for the majority of the cases, up to 87% of unilateral cataracts remain idiopathic, making disease prevention an ongoing challenge. Early diagnosis and timely referral to ensure effective genetic counselling and postnatal follow‐up is paramount to prevent long‐term visual consequences. We describe three cases of congenital cataracts with incongruence in antenatal ultrasound findings and postnatal results. Improvement over time in the diagnostic sensitivity of ultrasound allows for early diagnosis of congenital cataracts, yet there is little published evidence regarding the sensitivity and specificity of ultrasound as a diagnostic modality. As congenital cataracts have significant long‐term implications if left untreated, such as loss of visual capacity and amblyopia, a targeted ultrasound survey should be performed at morphology scans, with a special focus on the orbital region. This should be extended to those with a significant family history of fetal eye abnormalities and severe malformations. Given the high proportion of idiopathic congenital cataracts, the scope of developing other preventative strategies is limited. Early and accurate diagnosis in the antenatal period may be feasible, by thorough examination of the eyes to detect ocular anomalies, especially in high‐risk individuals.
Echo workforce development in the Fiji Islands
Authors: Harris Anna
Published: February 2020

Echocardiography has a wide scope of practice and requires many years of training and experience for one to be proficient; however, contextualised echo may be taught for the purpose of screening for rheumatic heart disease (RHD). In recent experience in the Fiji Islands, an echo workforce training programme was implemented with the intention of teaching general sonographers and physicians echo for the purpose of screening RHD with very positive results. This course was completed over three separate one week courses in a clinical setting.
How to perform a gynaecological ultrasound in the paediatric or adolescent patient
Authors: Deslandes Alison , Pannucio Catrina , Parasivam Shreya , Balogh Marianne , Short Asha
Published: February 2020

Ultrasound is the first‐line imaging modality in the assessment of the female reproductive system in all age groups. However, the paediatric and adolescent subset of patients present a particular set of challenges. These include technical challenges that come from largely being limited by transabdominal imaging as well as dealing with the often‐complex social issues around the sexual health of adolescents. In addition, this group of patients has a unique set of pathologies that are not seen in the adult population and conversely, common gynaecological conditions affecting adults such as endometriosis and polycystic ovarian syndrome are difficult to diagnose in adolescents. Therefore, we propose that paediatric and adolescent gynaecological ultrasound requires a different approach. This paper summarises the differences in technique, common pathologies and touches on some of the relevant social issues that are unique to this population of patients.
Synthesis and Functionalization of Allenes by Direct Pd‐Catalyzed Organolithium Cross‐Coupling
Authors: Mateos‐Gil Jaime , Mondal Anirban , Castiñeira Reis Marta , Feringa Ben L.
Published: February 2020

A palladium‐catalyzed cross‐coupling between in situ generated allenyl/propargyl‐lithium species and aryl bromides to yield highly functionalized allenes is reported. The direct and selective formation of allenic products preventing the corresponding isomeric propargylic product is accomplished by the choice of SPhos or XPhos based Pd catalysts. The methodology avoids the prior transmetalation to other transition metals or reverse approaches that required prefunctionalization of substrates with leaving groups, resulting in a fast and efficient approach for the synthesis of tri‐ and tetrasubstituted allenes. Experimental and theoretical studies on the mechanism show catalyst control of selectivity in this allene formation.
Visible‐Light‐Promoted C(sp3)−H Alkylation by Intermolecular Charge Transfer: Preparation of Unnatural α‐Amino Acids and Late‐Stage Modification of Peptides
Authors: Wang Chao , Qi Rupeng , Xue Hongxiang , Shen Yuxuan , Chang Min , Chen Yaqiong , Wang Rui , Xu Zhaoqing
Published: February 2020

Disclosed herein is the visible‐light‐promoted deaminative C(sp3)−H alkylation of glycine and peptides using Katritzky salts as electrophiles. Simple reaction conditions and excellent functional‐group tolerance provide a general strategy for the efficient preparation of unnatural α‐amino acids and precise modification of peptides with unnatural α‐amino‐acid residues. Mechanistic studies suggest that visible‐light‐promoted intermolecular charge transfer within a glycine–Katritzky salt electron donor‐acceptor (EDA) complex induces a single‐electron transfer process without the assistance of photocatalyst.
Gold(I)‐katalysierte Haloalkinylierung von Arylalkinen: Zwei Wege, ein Ziel
Authors: Kreuzahler Mathis , Haberhauer Gebhard
Published: February 2020

Haloalkinylierungsreaktionen sind effiziente Methoden zur gleichzeitigen Einführung eines Halogenatoms und einer Acetyleneinheit. Wir stellen hier zum ersten Mal eine Gold(I)‐katalysierte Haloalkinylierung von Arylalkinen vor, die ausschließlich das cis‐Additionsprodukt liefert. Dieses Protokoll ermöglicht den direkten Zugang zu konjugierten und halogenierten Eninen mit Ausbeuten bis zu 90 %. Bemerkenswert ist hierbei, dass quantenchemische Berechnungen ein außergewöhnliches Wechselspiel für den regioselektiven Angriff auf das Chloracetylen zeigen: Ganz gleich welche C‐C‐Bindung geknüpft wird, es entsteht stets das gleiche Enin. Dies ist nur durch Umlagerung des entsprechenden Molekülgerüstes möglich. Hierbei verläuft ein Reaktionspfad über ein Chloroniumion mit anschließender Arylumlagerung. Im zweiten Fall wird das entsprechende Vinylkation über eine 1,3‐Chlorumlagerung stabilisiert. 13C‐Markierungsexperimente bestätigen, dass die Reaktion über beide Reaktionspfade verläuft.
Electrochemical Synthesis of Thienoacene Derivatives: Transition‐Metal‐Free Dehydrogenative C−S Coupling Promoted by a Halogen Mediator
Authors: Mitsudo Koichi , Matsuo Ren , Yonezawa Toki , Inoue Haruka , Mandai Hiroki , Suga Seiji
Published: February 2020

The first electrochemical dehydrogenative C−S bond formation leading to thienoacene derivatives is described. Several thienoacene derivatives were synthesized by dehydrogenative C−H/S−H coupling. The addition of nBu4NBr, which catalytically promoted the reaction as a halogen mediator, was essential.
Electrocatalytic hydrogen evolution using triaryl corrole cobalt complex
Authors: Lin Huan , Hossain Md Sahadat , Zhan Shu‐Zhong , Liu Hai‐Yang , Si Li‐Ping
Published: February 2020

Three cobalt triaryl corroles bearing an electron‐withdrawing or electron‐donating group at 10‐meso‐phenyl were synthesized and characterized. Two of them are new cobalt corroles prepared in this study. These cobalt corroles were characterized using high‐resolution mass spectrometry, UV–Vis., nuclear magnetic resonance, X‐ray photoelectron spectroscopy, and single‐crystal X‐ray structure determination. All synthesized cobalt corroles efficiently catalyzed the hydrogen evolution reaction (HER) in neutral aqueous media at an overpotential of 838 mV. The HER activity of these cobalt corroles significantly depended on the virtue of peripheral substituents.
Simulation, equipment performance evaluation and sensitivity analysis as a comprehensive parametric study of sulfur recovery unit
Authors: Hashemi Meysam , Pourfayaz Fathollah , Mehrpooya Mehdi
Published: February 2020

The sulfur recovery unit based on modified Claus process with split flow was simulated, so that the validation results showed satisfactory agreement with the refinery data. In this study, comprehensive investigation was carried out on various parameters of the unit. Concentration changes of compounds were investigated as the process stream passes along various equipment. Composite curves were generated, and the minimum approach temperature was calculated as one of the operational parameters of heat exchangers. Fluid condensation probability was investigated in catalytic reactors. The recovery of sulfur and the amount of sulfur production were calculated by process streams passing along catalytic reactors and condensers respectively. The most influential performance parameters including the fuel flow rate, combustion air flow rate, and bypasses fraction were considered as sensitivity analysis parameters, and their variation influences were investigated on the recovery of sulfur, the ratio of hydrogen sulfide to sulfur dioxide, the amount of produced steam, and the furnace outlet stream temperature. The optimal amounts for fuel flow rate and inlet air flow rate were calculated with the values of 0 and 202 mol/s, respectively, and according to the results, 15% of the mainstream flow rate gives the optimum amount of bypass fraction.