bluuebunny/crossref_metadata_2025 huggingface dataset:
“Cada cual en su cuadrado” Segregación socioespacial y desigualdades raciales en Salvador contemporáneo
Authors:   Universidade Federal da Bahia, Salvador, Brasil., Carvalho Inaiá , Arantes Rafael ,   Universidade Federal da Bahia, Salvador, Brasil.
Published: April 2021

Este texto examina la forma en que los patrones de la segregación socioespacial y sus impactos se articulan con las desigualdades raciales en la sociedad brasileña. Procede con base en datos de los Censos demográficos, de las Encuestas Nacionales de Hogares y de algunas investigaciones empíricas realizadas en Salvador, capital del estado de Bahía, que constituye actualmente la cuarta ciudad más grande del país y donde los negros representan la mayoría absoluta de la población. Para ello se refiere inicialmente a la cuestión de la segregación y del denominado “efecto territorio”, abordando la literatura sobre esos fenómenos y sobre su desarrollo. Se analiza, a continuación, cómo los patrones de segregación se articulan con las desigualdades raciales y cómo la concentración de moradores pobres y mayoritariamente negros en áreas homogéneas, precarias y desasistidas agrava su desposesión y su vulnerabilidad, resaltando que la apropiación diferenciada del territorio urbano también contribuye a la persistencia y al agravamiento de las desigualdades raciales en Brasil.
Desplazamientos y gentrificación, ¿una relación necesaria? Estudio cuantitativo en la ciudad de Córdoba, Argentina (1991–2010)
Authors:   Centro de Estudios Urbanos y Regionales (ceurconicet), Buenos Aires, Argentina, Rodríguez Gonzalo-Martín
Published: April 2021

El fenómeno de los desplazamientos de población de clase baja se asume generalmente como asunto clave al momento de evaluar el impacto de políticas públicas e iniciativas privadas orientadas a la renovación urbana y gentrificación en las áreas centrales. El presente trabajo propone una metodología cuantitativa donde, a partir de datos censales, se examina si la llegada de clases medias y altas a un sector central de la ciudad (uno de los aspectos más característicos de la gentrificación) guarda relación con el posible desplazamiento de habitantes originarios de clase baja. El caso de estudio es la ciudad de Córdoba, Argentina, entre los años 1991 y 2010. Los resultados sugieren que el desplazamiento de clases bajas es fuerte en el área central, pero estos desplazamientos no estarían necesariamente vinculados a la gentrificación.
Seguridad, desconfianza y la dimensión simbólica de la segregación en urbanizaciones cerradas
Authors:   Universidad Autónoma Metropolitana Azcapotzalco, Ciudad de México, México, Capron Guénola
Published: April 2021

El artículo busca analizar la dimensión simbólica de la segregación residencial dentro de las urbanizaciones cerradas. A partir de un enfoque espacial micro, examina la idea de la integración social y funcional entre conjuntos cerrados y barrios pobres. Basado en entrevistas a residentes y empleados, propone estudiar las prácticas, sus significados y las representaciones de residentes y empleadas domésticas de urbanizaciones cerradas de la Zona Metropolitana del Valle de México. Si bien las prácticas de separación física y distanciación simbólica dentro de la casa reflejan una discriminación y una desconfianza histórica de las clases acomodadas hacia los pobres, los dispositivos sociales y espaciales de segurización y segregación que operan como clasificadores de los individuos en función de su grado de confiabilidad y peligrosidad, instauran un orden, nuevo, de una institución de vigilancia privada. La cercanía física entre grupos genera una segregación simbólica, efecto perverso de la segregación económica y política.
Cuando lo técnico se torna político: un análisis del proyecto de modificación excepcional del Plan de Ordenamiento Territorial de Bogotá a partir del marco de coaliciones promotoras
Authors:   Pontificia Universidad Católica de Chile, Santiago, Chile, Sánchez-Ospina Adriana-Marcela , Hernández-Mora Sebastián ,   Universidad Nacional Autónoma de México, Ciudad de México, México.
Published: April 2021

El Plan de Ordenamiento Territorial es una política pública de los municipios colombianos, que a través de un conjunto de directrices delimita instrumentos de planeación, gestión y financiación. Sin embargo, para que se implemente es necesario que el Concejo Distrital, un órgano político, lo apruebe. Este artículo analiza, a partir de entrevistas, actas del Concejo y revisión de la prensa, las creencias y posiciones de los actores políticos durante el trámite de modificación excepcional del Plan de Ordenamiento Territorial presentado al Concejo de Bogotá el año 2013, utilizando metodológicamente el marco de coaliciones promotoras. Se concluye que, pese a ser un proyecto técnico, la discusión alrededor del mismo se tornó política en el Concejo, por las relaciones tensas entre el gobierno nacional y el municipal y por la presión de los grupos de interés, que produjeron como resultado el archivo del proyecto normativo.
Consumo, ciudadanía y creditización de la vida urbana en ciudades medias brasileñas
Authors:   Universidade Estadual Paulista (unesp-Presidente Prudente), São Paulo, Brasil., Ruiz Nicolas
Published: April 2021

Título libro: Consumo, crédito e direito à cidade Autores: E. M. Góes, I. Catalão, M. A. O. Magrini, L. A. Furini, M. J. V. Catelan & M. E. B. Sposito Edición: Curitiba, Paraná: Editora Appris, 2019 (223 pgs.) ISBN: 978-85-473-8510-7
Empreendedorismo sustentável: mapeamento da produção científica internacional entre 2009 e 2019
Authors: Bezerra Paloma , Araújo de Souza Sandra , Gonçalves Geuda
Published: April 2021

Esta pesquisa teve o objetivo de mapear a produção científica internacional sobre empreendedorismo sustentável entre os anos de 2009 e 2019. Realizou-se um estudo exploratório e descritivo, no qual os dados coletados foram coletados da base de dados da Web Of Science. Foram delineados a evolução da produção científica sobre o tema, os autores mais prolíficos e as fontes de publicação com maior volume de publicações. O software bibliométrico VOSViewer foi utilizado para analisar as redes bibliométricas de: coocorrência de palavras-chave, coautoria e cocitação. Conclui-se que o tema está em evolução no cenário internacional, constatou-se uma grande dispersão nos estudos sobre o tema. Os estudos integram o empreendedorismo tradicional com diferentes eixos de pesquisa, em especial, à inovação, à gestão estratégica e à sustentabilidade social e ambiental.
A Relação entre a Prática Docente e a Síndrome de Burnout na Rede Pública de Ensino
Authors: Pimenta Brenda Fyamma Fernandes , De Oliveira Agostinha Mafalda Barra , De Sousa Juliana Carvalho , Da Silva Pablo Marlon Medeiros
Published: April 2021

O objetivo deste estudo consistiu em analisar a relação entre os fatores individuais, sociais, funcionais e organizacionais com a prevalência da SB em professores da rede pública de ensino. Para tanto, a pesquisa, de caráter descritivo e explicativo com abordagem quantitativa utilizou como instrumentos de coleta de dados dois questionários, o Maslach Burnout Inventory “Educators Survey-Es” (MBI-ED) e o Sócio-Funcional (QSF), adaptado de Carneiro (2010), aplicados com 65 professores efetivos de escolas do Estado do Rio Grande do Norte que ministram aulas no ensino médio. Os dados coletados foram submetidos a testes estatísticos envolvendo a correlação de Pearson e Anova com auxílio do SPSS versão 21. Os resultados apontaram que cerca de um quinto dos professores investigados apresentou alta prevalência da síndrome e outros 33% tendência a desenvolvê-la. Houve correlação significa entre um fator pessoal e dois fatores funcionais com uma das dimensões da SB. O estudo traz contribuições relevantes, uma vez que a conscientização organizacional acerca das nuances da síndrome e a adoção de medidas que visem amenizar seus impactos nos indivíduos pode tornar o ambiente de trabalho mais saudável e efetivo.
Motivação e desafios de empreendedores na criação e manutenção de organizações sociais em Aracaju: estudo de múltiplos casos
Authors: Brilhante Kamille , Olave Maria , Ouro Abimael
Published: April 2021

Este estudo buscou analisar como empreendedores sociais criam e mantêm suas instituições. Para tal, foram escolhidas três instituições sociais que atuam em Aracaju, Sergipe, sendo elas: AMO, AVOSOS E GAAC. O método de pesquisa adotado foi o estudo de casos múltiplos com abordagem qualitativa de caráter descritivo, utilizando como técnica de investigação a análise de conteúdo. As informações foram coletadas utilizando um roteiro de entrevista semiestruturado que foram aplicados junto aos representantes de cada instituição. A análise comparativa dos casos mostrou que a motivação dos empreendedores sociais se baseia na satisfação pessoal de ajudar o próximo, sendo a principal fonte de captação de recursos o telemarketing. O empreendedorismo social no contexto pesquisado nasce com o intuito de ajudar ao próximo, mas a manutenção e desenvolvimento demonstra ser de grandes desafios principalmente na área financeira. Os resultados demonstram que a abertura de empreendedorismo desse setor necessita de um planejamento bem estruturado para que a sua manutenção não fique ameaçada.
De repente professor: uma análise sobre a dupla jornada dos Secretários Executivos atuando como docentes
Authors: Rodrigues Juliene do Socorro Cardoso , Paes Raul Vitor Oliveira , Costa Wheeler Wallace Levy Sinezio
Published: April 2021

Para o profissional de secretariado, a docência tem emergido enquanto novo desafio. Considerando essa discussão, o presente trabalho objetivou analisar os benefícios, as dificuldades, semelhanças e diferenças da atuação paralela como secretário executivo (SE) e docente. O referencial teórico foi baseado nas temáticas sobre dupla jornada e trabalho docente, as vertentes de atuação do profissional de secretariado executivo contemporâneo, além de reflexões sobre a figura dos secretários-docentes. O estudo é de cunho exploratório e descritivo, com abordagem qualitativa e técnica de análise de conteúdo. A coleta de dados foi realizada por meio de questionário enviado a 11 (onze) profissionais de secretariado que atuam ou já atuaram em dupla jornada. Os resultados evidenciam que os principais benefícios são: intercâmbio de conhecimento, ampliação da rede de relacionamentos, atualização constante e transmissão de experiências profissionais. Entre as dificuldades estão a falta de tempo, desgaste psicológico, cansaço e acúmulo de funções. Quanto às semelhanças identificadas estão responsabilidade, comprometimento, gestão da informação e de pessoas, gestão do tempo e relacionamento interpessoal. As principais diferenças entre as duas atuações residem na flexibilidade da atuação docente e maior autonomia na docência.
As dimensões do cross-cultural competence inventory como estruturantes do desenvolvimento de competência intercultural em programas de mobilidade acadêmica internacional
Authors: De Melo José Lucas Lara , Bueno Janaina Maria , Domingues Carlos Roberto
Published: April 2021

A expansão internacional das organizações e a valorização da diversidade cultural demandam por profissionais interculturalmente competentes (Spitzberg, 2009), sendo a Competência Intercultural um conjunto de atitudes, habilidades e conhecimentos que permitem ao indivíduo prosperar em ambientes e relações multiculturais (Deardorff, 2006). Frente a esta realidade, as Instituições de Ensino Superior (IES) têm investido esforços para viabilizar a mobilidade acadêmica internacional dos docentes e discentes, o que contribui para a inserção internacional destas instituições e formação de cidadãos globais (Pagani, Kovaleski & Kovaleski, 2016). Neste contexto, o objetivo deste ensaio teórico foi discutir como a competência intercultural pode ser desenvolvida e mensurada em programas de mobilidade acadêmica internacional de IES brasileiras, a partir das dimensões validadas no Cross-Cultural Competence Inventory (CCCI) de Ross, Thomson, Mcdonald e Arrastia (2009) e sua versão adaptada ao português (Guedes Neto, Avrichir, Silva & Figueiredo, 2016). Conclui-se que as 6 dimensões validadas no CCCI se constituem em importante guia para ações de programas de mobilidade acadêmica internacional de IES brasileiras. Ademais, é necessária a aproximação dos estudos sobre internacionalização de IES com a discussão e proposições de políticas e programas de mobilidade acadêmica e a literatura sobre competência intercultural, abrindo possibilidades de pesquisa e contribuições práticas.
Behavioural Changes in the Personal and Professional Lives of Doctors during COVID-19 Pandemic: A Cross-sectional Observational Study
Authors: Parasher Vivek , Shekhawat Kamlesh Kanwar , Bhati Sonal , Sharma Mansi
Published: April 2021

Introduction: During the Corona Virus Disease (COVID-19) pandemic, Health Care Workers (HCWs) have experienced an unexpected increase in workload which leads to feelings of uncertainty, anxiety, and isolation. Furthermore, they are more vulnerable to contract the infection and transmit it to their family and colleagues. Aim: To evaluate the effect of COVID-19 pandemic on doctors life in term of personal and professional changes. Materials and Methods: The present observational, cross-sectional study was conducted on doctors in various institutes of Udaipur, Rajasthan, India. The study comprised an online questionnaire survey which consisted of three parts; the first part constituted demographic data, the second one constituted questions on the personal life status and changes, and the third part constituted questions regarding the professional life and some miscellaneous questions gauging the doctor’s knowledge of the current scenario. The collected data were entered in a Microsoft excel sheet, and the results were calculated. Results: Most of the participants were between 25-34 years (47.8%) and male (71%). A majority of the doctors had a family with children (44.2%) and a spouse who was a HCW too (59.8%). A majority of the practitioners worked with patients with coronavirus (52.3%) and thus felt worried about their family members (93.3%). Although most participants knew about telemedicine (89.3%), most of the practitioners did not practice it (76.8%). Conclusion: Although HCWs do not face harassment, they suffer anxiety regarding contracting COVID-19 themselves and transmitting it to their family members.
An Observational Study to Assess Anxiety Disorder among Women during COVID-19 Pandemic
Authors: Sain Sonali , Dey Indira
Published: April 2021

Introduction: World Health Organisation (WHO) declared 2019 Coronavirus Disease (COVID-19) infection as a pandemic. Government of India imposed a nationwide lockdown to break the chain of transmission in the community to halt the pandemic. The unprecedented measure led to severe emotional distress among the general population, especially women. Aim: To assess the burden of anxiety disorder perceived by women during the COVID-19 pandemic and their precipitating factors. Materials and Methods: An observational cross-sectional study was conducted among the women residing in West Bengal for more than six months and has access to electronic media, internet services, and/or with an account in any social media. The online survey was conducted via electronic communication and the snowball sampling method was used to recruit 980 study participants. An electronic version of a semi-structured questionnaire was developed with a consent form attached to it and the link of the questionnaire was sent through e-mails, WhatsApp, and other social media to the contacts of the researcher. A self-administered questionnaire obtained information regarding socio-demographic features, personal history, past history of chronic morbidity, family history, and anxiety disorder by Generalised Anxiety Disorder-7 item (GAD-7) scale. Chi-square test and multiple logistic regression were used as a test of significance. The data was compiled, analysed, and presented. Results: Around 203 (20.7%) adult women were suffering from reasonable anxiety. Socio-demographic factors like residence, religion, education, and profession were more significantly associated but age, family type, and marital status were not significantly associated. Addiction, chronic morbidity, and experience of recurrent non-specific signs and symptoms had a significant association with reasonable anxiety. The regression model explained that working women had less chance and those with recurrent non-specific symptoms had more chance to suffer from reasonable anxiety. Conclusion: The study assessed the burden of anxiety disorder faced by women during the pandemic. It has provided further insight into the risk factors associated with it and a person’s vulnerability to anxiety disorder. Thus, it helped in developing targeted intervention strategies for the vulnerable segment of the population.
Externally added cystatin C reduces growth of A375 melanoma cells by increasing cell cycle time
Authors: Wallin Hanna , Hunaiti Samar , Abrahamson Magnus
Published: April 2021

Some secreted cysteine protease inhibitors of the cystatin family appear to affect intracellular proteolysis and growth of human cells, as a result of internalization. Here, we studied the effects of external addition of the most abundant human cystatin, cystatin C, on viability and proliferation of cancer cells in culture. A dose‐dependent decrease in viable cells was seen for A375 melanoma, MCF‐7 breast cancer, and PC‐3 prostate cancer cells cultured in 1–5 µm cystatin C after 24 h. Real‐time assessment of growth rates in A375 cell cultures for 48 h by digital holographic microscopy showed an increased doubling time for cells cultured in the presence of 5 µm cystatin C (20.1 h) compared with control cells (14.7 h). A prolonged doubling time was already observed during the first 12 h, indicating a rapid general decrease in cell proliferation at the population level. Tracking of individual cells in phase holographic images showed that dividing cells incubated with 5 µm cystatin C underwent fewer mitoses during 48 h than control cells. In addition, the time between cell divisions was longer, especially for the first cell cycle. Incubation with the variant W106F‐cystatin C (with high cellular uptake rate) resulted in a lower number of viable cells and a prolonged doubling time than when cells were incubated with wild‐type cystatin C, but no effect was observed for (R24A,R25A)‐cystatin C (low cellular uptake). Thus, cystatin C causes prolonged cell division leading to decreased proliferation of melanoma cells, and internalization seems to be a prerequisite for this effect.
Nonfragile control design for consensus of semi‐Markov jumping multiagent systems with disturbances
Authors: Sakthivel Rathinasamy , Parivallal Arumugam , Huy Tuan Nguyen , Manickavalli Subramanian
Published: April 2021

The consensus problem for multiagent systems (MASs) with semi‐Markov jumping parameters under the influence of disturbances is investigated in this article. In the first part of this article, an extended dissipative approach is used for the consensus of MASs with semi‐Markovian jumping parameters and external disturbances via nonfragile controller with randomly occurring gain fluctuations. Besides, in the second part of the article, the consensus of stochastic semi‐Markovian jumping MASs via nonfragile controller subject to probabilistic time‐varying delay is discussed. The primary motive of this article is to develop a robust controller such that the considered MASs with semi‐Markov jumping parameters achieve consensus in the presence of external disturbances. For this, the chosen problems are first converted to stabilization problems then by using Lyapunov stability theory and linear matrix inequality approach, the stabilization criterion have been established. At last, two numerical examples are worked out to illustrate the efficiency of the proposed control methodologies.
Engineering Solid Electrolyte Interface at Nano‐Scale for High‐Performance Hard Carbon in Sodium‐Ion Batteries
Authors: Ma Mengying , Cai Haoran , Xu Chenlu , Huang Renzhi , Wang Shurong , Pan Huilin , Hu Yong‐Sheng
Published: April 2021

Engineering the structure and chemistry of solid electrolyte interface (SEI) on electrode materials is crucial for rechargeable batteries. Using hard carbon (HC) as a platform material, a correlation between Na+ storage performance, and the properties of SEI is comprehensively explored. It is found that a “good” SEI layer on HC may not be directly associated with certain kinds of SEI components, such as NaF and Na2O. Whereas, arranging nano SEI components with refined structures constructs the foundation of “good” SEI that enables fast Na+ storage and interface stability of HC in Na‐ion batteries. A layer‐by‐layer SEI on HC with inorganic‐rich inner layer and tolerant organic‐rich outer flexible layer can facilitate excellent rate and cycling life. Besides, SEI layer as the gate for Na+ from electrolyte to HC electrode can modulate interfacial crystallographic structures of HC with pillar‐solvent that function as “pseudo‐SEI” for fast and stable Na+ storage in optimal 1 m NaPF6‐TEGDME electrolytes. Such a layer‐by‐layer SEI combined with a “pseudo‐SEI” layer for HC enables an outstanding rate of 192 mAh g−1 at 2 C and stable cycling over 1100 cycles at 0.5 C. This study provides valuable guidance to improve the electrochemical performance of electrode materials through regulation of SEI in optimal electrolytes.
Biocompatibility Evolves: Phenomenology to Toxicology to Regeneration
Authors: Crawford Lars , Wyatt Meghan , Bryers James , Ratner Buddy
Published: April 2021

The word “biocompatibility,” is inconsistent with the observations of healing for so‐called biocompatible biomaterials. The vast majority of the millions of medical implants in humans today, presumably “biocompatible,” are walled off by a dense, avascular, crosslinked collagen capsule, hardly suggestive of life or compatibility. In contrast, one is now seeing examples of implant biomaterials that lead to a vascularized reconstruction of localized tissue, a biological reaction different from traditional biocompatible materials that generate a foreign body capsule. Both the encapsulated biomaterials and the reconstructive biomaterials qualify as “biocompatible” by present day measurements of biocompatibility. Yet, this new generation of materials would seem to heal “compatibly” with the living organism, where older biomaterials are isolated from the living organism by the dense capsule. This review/perspective article will explore this biocompatibility etymological conundrum by reviewing the history of the concepts around biocompatibility, today's standard methods for assessing biocompatibility, a contemporary view of the foreign body reaction and finally, a compendium of new biomaterials that heal without the foreign body capsule. A new definition of biocompatibility is offered here to address advances in biomaterials design leading to biomaterials that heal into the body in a facile manner.
An Adhesive‐Integrated Stretchable Silver‐Silver Chloride Electrode Array for Unobtrusive Monitoring of Gastric Neuromuscular Activity
Authors: Kurniawan Jonas F. , Tjhia Boris , Wu Vincent M. , Shin Andrew , Sit Nathan L. J. , Pham Timothy , Nguyen Andrew , Li Carleen , Kumar Rajan , Aguilar‐Rivera Marcelo , Lerman Imanuel , Kunkel David C. , Coleman Todd P.
Published: April 2021

Here, an unobtrusive, adhesive‐integrated electrode array for continuous monitoring of stomach electric activity is introduced. This patient‐friendly, disposable peel‐and‐stick adhesive device represents an important advancement over existing arrays that require placement of each electrode individually and are thus also labor intensive and are in general more rigid and cumbersome. In comparison to other silver–silver chloride electrodes, this skin conformal array does not require gel and thus can withstand low impedance over the duration of long recordings. Interfacing these electrodes with miniaturized electronic recording and wireless telemetry systems has the potential to enable scalable population health opportunities to perform objective gastrointestinal assessment and optimization of treatment regimens.
Highly Sensitive and Selective Gas Sensor Using Heteroatom Doping Graphdiyne: A DFT Study
Authors: Wu Yang , Chen Xingzhu , Weng Kaiyi , Arramel  , Jiang Jizhou , Ong Wee‐Jun , Zhang Peng , Zhao Xiujian , Li Neng
Published: April 2021

The emergence of a two‐dimensional (2D) functionalized‐graphene structure, graphdiyne (GDY), promoting non‐metallic single atoms level to tailor its gas sensing performance. Herein, pristine, non‐metallic atom (N, B) doped 2D GDY is investigated for toxic and greenhouse gases sensing (CO, CO2, CH4, HCHO, H2S, SO2, SO3, NO2, NO, and NH3). The B‐doped GDY (B‐GDY) compared with pure or N doped GDY displays gas sensitivity, especially excellent sensitivity and selectivity toward NO, NO2, and NH3. Additionally, a humid environment has demonstrated no effect on the weakening selectivity of B‐GDY for the studied gases. Meanwhile, the effect of external electric field (E‐field) on sensing was calculated, indicating that the bandgap of NO‐adsorbed system reached the lowest 0.188 eV at −0.5 V Å−1 and the highest 0.363 eV at −0.1 V Å−1. This work paves the way on designing efficient and effective gas sensor toward toxic nitrogen‐based gases on GDY.
Spinterfaces Manipulate Large Magnetic Field Effects in 3D and Quasi‐2D Organic–Inorganic Hybrid Perovskites
Authors: Pan Ruiheng , Wang Kai , Li Yang , Yu Haomiao , Li Jinpeng , Xu Ling
Published: April 2021

Spinterfaces are due to the orbital hybridization at an interface of a ferromagnet and a nonmagnetic semiconductor. Interfacial densities of states (i‐DOS) are spin‐dependent, which may offer the spin‐filter effect for enhancing spin‐polarized charge injection efficiency and magnetic field effects (MFEs). In the work, a prototypical perovskite spin valve (PeSV) comprising Ni/MAPbI3−xClx/Ni (MA = CH3NH3) is fabricated, showing a clear magnetic switching behavior in the ambient condition. It is further explored by studying the magnetophotocurrent (MPC) at the short‐circuit current density condition (magneto‐Jsc). Anomalously large magneto‐Jsc can be detected by comparing to devices with nonmagnetic Au electrodes. The effect can be more pronounced for the quasi‐2D perovskite such as (PEA)2(MA)3Pb4I13 (PEA = C6H5(CH2)2NH3). At low fields, the hyperfine field induced spin‐mixing shows remarkable magneto‐Jsc signals for it. In addition, the circularly and linearly polarized laser beam can effectively manipulate the magnitude of magneto‐Jsc for both MAPbI3−xClx and (PEA)2(MA)3Pb4I13. It is postulated that the formation of the spinterfaces may play a dominant role for the large and tunable magneto‐Jsc effect. These studies may pave the way for future experimental and theoretical studies in the field.
Guiding the Design of Heterogeneous Electrode Microstructures for Li‐Ion Batteries: Microscopic Imaging, Predictive Modeling, and Machine Learning
Authors: Xu Hongyi , Zhu Juner , Finegan Donal P. , Zhao Hongbo , Lu Xuekun , Li Wei , Hoffman Nathaniel , Bertei Antonio , Shearing Paul , Bazant Martin Z.
Published: April 2021

Electrochemical and mechanical properties of lithium‐ion battery materials are heavily dependent on their 3D microstructure characteristics. A quantitative understanding of the role played by stochastic microstructures is critical for the prediction of material properties and for guiding synthesis processes. Furthermore, tailoring microstructure morphology is also a viable way of achieving optimal electrochemical and mechanical performances of lithium‐ion cells. To facilitate the establishment of microstructure‐resolved modeling and design methods, a review covering spatially and temporally resolved imaging of microstructure and electrochemical phenomena, microstructure statistical characterization and stochastic reconstruction, microstructure‐resolved modeling for property prediction, and machine learning for microstructure design is presented here. The perspectives on the unresolved challenges and opportunities in applying experimental data, modeling, and machine learning to improve the understanding of materials and identify paths toward enhanced performance of lithium‐ion cells are presented.
How ancestral subsistence strategies solve salmon starvation and the “protein problem” of Pacific Rim resources
Authors: Tushingham Shannon , Barton Loukas , Bettinger Robert L.
Published: April 2021

This article provides a theoretical treatment of hunter–gatherer diet and physiology. Through a synthesis of nutritional studies, informed by ethno‐archaeological data, we examine the risk of protein‐rich diets for human survival, and how societies circumvent "salmon starvation" in the northeastern Pacific Rim. Fundamental nutritional constraints associated with salmon storage and consumption counter long‐standing assumptions about the engine of cultural evolution in the region. Excess consumption of lean meat can lead to protein poisoning, termed by early explorers “rabbit starvation.” While consumption of fats and carbohydrates is widely portrayed as a pathway to “offsetting” protein thresholds, there are true limits to the amount of protein individuals can consume, and constraints are most extreme for smaller individuals, children, and pregnant/nursing mothers. While this problem is not usually perceived as associated with fish, the risk of protein poisoning limits the amount of low‐fat fish that people can eat safely. Compared with smaller, mass‐harvested species (e.g., eulachon), dried salmon are exceedingly lean. Under certain circumstances fattier foods (small forage fish, marine mammals, whales, and even bears) or carbohydrate‐rich plants may have been preferred not just for taste but to circumvent this “dietary protein ceiling.” Simply put, “salmon specialization” cannot evolve without access to complimentary caloric energy through fat‐rich or carbohydrate‐rich resources. By extension, the evolution of storage‐based societies requires this problem be solved prior to or in tandem with‐salmon intensification. Without such solutions, increased mortality and reproductive rates would have made salmon reliance unsustainable. This insight is in line with genomic research suggesting protein toxicity avoidance was a powerful evolutionary force, possibly linked to genetic adaptations among First Americans. It is also relevant to evaluating the plausibility of other purportedly “focal” economies and informs understanding of the many solutions varied global societies have engineered to overcome physiological protein limits.
Evidence of Mars‐Van‐Krevelen Mechanism in the Electrochemical Oxygen Evolution on Ni‐Based Catalysts
Authors: Ferreira de Araújo Jorge , Dionigi Fabio , Merzdorf Thomas , Oh Hyung‐Suk , Strasser Peter
Published: April 2021

Water oxidation is a crucial reaction for renewable energy conversion and storage. Among the alkaline oxygen evolution reaction (OER) catalysts, NiFe based oxyhydroxides show the highest catalytic activity. However, the details of their OER mechanism are still unclear, due to the elusive nature of the OER intermediates. Here, using a novel differential electrochemical mass spectrometry (DEMS) cell interface, we performed isotope‐labelling experiments in 18O‐labelled aqueous alkaline electrolyte on Ni(OH)2 and NiFe layered double hydroxide nanocatalysts. Our experiments confirm the occurrence of Mars‐van‐Krevelen lattice oxygen evolution reaction mechanism in both catalysts to various degrees, which involves the coupling of oxygen atoms from the catalyst and the electrolyte. The quantitative charge analysis suggests that the participating lattice oxygen atoms belong exclusively to the catalyst surface, confirming DFT computational hypotheses. Also, DEMS data suggest a fundamental correlation between the magnitude of the lattice oxygen mechanism and the faradaic efficiency of oxygen controlled by pseudocapacitive oxidative metal redox charges.
Rational Design of Multicolor‐Emitting Chiral Carbonized Polymer Dots for Full‐Color and White Circularly Polarized Luminescence
Authors: Ru Yi , Sui Laizhi , Song Haoqiang , Liu Xingjiang , Tang Zhiyong , Zang Shuang‐Quan , Yang Bai , Lu Siyu
Published: April 2021

Light‐emitting chiral carbonized polymer dots (Ch‐CPDs) are attracting great interest because of their extraordinary photonic properties, but modulating their band‐gap emission, especially at long wavelength, and maintaining their chiral structure to achieve multicolor, high‐emission Ch‐CPDs remains challenging. Reported here for the first time is the synthesis of red‐ and multicolor‐emitting Ch‐CPDs using the common precursorsL‐/D‐tryptophan ando‐phenylenediamine, and a solvothermal approach at one temperature. The quantum yield of the Ch‐CPDs was between 31 % and 54 %. Supramolecular self‐assembly provided multicolor‐emitting Ch‐CPDs showing novel circularly polarized luminescence, with the highest dissymmetric factor (glum) of 1×10−2. Importantly, circularly polarized white‐emitting CPDs were fabricated for the first time by tuning the mixing ratio of the three colored Ch‐CPDs in a gel. This strategy affords exciting opportunities for designing functional chiroptical materials.
Exciton‐Mediated Energy Transfer in Heterojunction Enables Infrared Light Photocatalysis
Authors: Li Yuanjin , Wang Hui , Zhang Xiaodong , Wang Shuhui , Jin Sen , Xu Xiaoliang , Liu Wenxiu , Zhao Zhi , Xie Yi
Published: April 2021

Although a few semiconductors can directly absorb infrared light, their intrinsic properties like improper band‐edge position and strong electron–hole interaction restrict further photocatalytic applications. Herein, we propose an exciton‐mediated energy transfer strategy for realizing efficient infrared light response in heterostructures. Using black phosphorous/polymeric carbon nitride (BP/CN) heterojunction, CN could be indirectly excited by infrared light with the aid of nonradiatively exciton‐based energy transfer from BP. At the same time, excitons are dissociated into free charge carriers at the interface of BP/CN heterojunction, followed by hole injection to BP and electron retainment in CN. As a result of these unique photoexcitation processes, BP/CN heterojunction exhibits promoted conversion rate and selectivity in amine–amine oxidative coupling reaction even under infrared light irradiation. This study opens a new way for the design of efficient infrared light activating photocatalysts.
Merging Pincer Motifs and Potential Metal–Metal Cooperativity in Cobalt Dinitrogen Chemistry: Efficient Catalytic Silylation of N2 to N(SiMe3)3
Authors: Li Ming , Gupta Sandeep K. , Dechert Sebastian , Demeshko Serhiy , Meyer Franc
Published: April 2021

Using a pyrazolate‐bridged dinucleating ligand that provides two proximate pincer‐type PNN binding sites (“two‐in‐one pincer”), different synthetic routes have been developed towards its dicobalt(I) complex 2 that features a twice deprotonated ligand backbone and two weakly activated terminal N2 substrate ligands directed into the bimetallic pocket. Protonation of 2 is shown to occur at the ligand scaffold and to trigger conversion to a tetracobalt(I) complex 4 with two end‐on μ1,2‐bridging N2; in THF 4 is labile and undergoes temperature‐dependent N2/triflate ligand exchange. These pyrazolate‐based systems combine the potential of exhibiting both metal–metal and metal–ligand cooperativity, viz. two concepts that have emerged as promising design motifs for molecular N2 fixation catalysts. Complex 2 serves as an efficient (pre)catalyst for the reductive silylation of N2 into N(SiMe3)3 (using KC8 and Me3SiCl), yielding up to 240 equiv N(SiMe3)3 per catalyst.
Triarylmethanes and their Medium‐Ring Analogues by Unactivated Truce–Smiles Rearrangement of Benzanilides
Authors: Abrams Roman , Jesani Mehul H. , Browning Alex , Clayden Jonathan
Published: April 2021

Intramolecular nucleophilic aromatic substitution (Truce–Smiles rearrangement) of the anions of 2‐benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SNAr reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring‐expanding variant (n to n+4) of the reaction provided a route to doubly benzo‐fused medium ring lactams of 10 or 11 members. Hammett analysis returned a ρ value consistent with the operation of a partially concerted reaction mechanism.
A Double Deprotonation Strategy for Cascade Annulations of Palladium–Trimethylenemethanes and Morita–Baylis–Hillman Carbonates to Construct Bicyclo[3.1.0]hexane Frameworks
Authors: Yang Zhen‐Hong , Chen Peng , Chen Zhi‐Chao , Chen Zhi , Du Wei , Chen Ying‐Chun
Published: April 2021

Here we report that the chemoselective activation of Tsuji's 2‐(cyanomethyl)allyl carbonates to generate the palladium–trimethylenemethane 1,3‐dipoles via a deprotonation strategy can be realized in the presence of Morita–Baylis–Hillman carbonates from substantial activated ketones. The following SN2′‐addition enables the formation of new 1,3‐dipole species having an activated alkene moiety through a second deprotonation process, which then undergo cascade [1+2]/[3+2] annulations to furnish complex bicyclic [3.1.0]hexane frameworks having three contiguous quaternary stereogenic centers with good to excellent enantioselectivity. Moreover, by using benzoyl aldehyde‐derived substrates, a [1+4]/[3+2] annulation sequence is similarly developed to produce fused cyclopenta[b]furan architectures.
Catalytic Asymmetric Synthesis of Silicon‐Stereogenic Dihydrodibenzosilines: Silicon Central‐to‐Axial Chirality Relay
Authors: Guo Yonghong , Liu Meng‐Meng , Zhu Xujiang , Zhu Liru , He Chuan
Published: April 2021

A Rh‐catalyzed asymmetric synthesis of silicon‐stereogenic dihydrodibenzosilines featuring axially chiral 6‐membered bridged biaryls is demonstrated. In the presence of a RhI catalyst with a chiral diphosphine ligand, a wide range of dihydrodibenzosilines containing both silicon‐central and axial chiralities are conveniently constructed in excellent enantioselectivities via dehydrogenative C(sp3)−H silylation. Absolute configuration analysis by single‐crystal X‐ray structures revealed a novel silicon central‐to‐axial chirality relay phenomenon, which we believe will inspire further research in the field of asymmetric catalysis and chiroptical materials.
Research on rotary nozzle structure and flow field of the spinneret for centrifugal spinning
Authors: Lai Zilong , Wang Jiawei , Liu Kang , Li Wenhui , Zhang Zhiming , Chen Boya
Published: April 2021

High‐speed centrifugal spinning is a novel method of fabricating nanofibers by use of centrifugal force field. The neoteric designs and proper structural parameters of spinning nozzle will change the outlet velocity and velocity distribution uniformity of spinning solution, which could affect the quality of nanofibers. Four different spinning nozzles that can be used for high‐speed centrifugal spinning are proposed. The flow of spinning solution in the different rotary nozzles is simulated based on the theoretical analysis. It can be found that the curved‐tube nozzle is better for high‐speed centrifugal spinning comparing with the velocity distribution of spinning solution in the four different spinning nozzles. The influence degree of the structure parameters of the curved‐tube nozzle on the solution outlet‐velocity is explored by orthogonal test method. The result shows that the curved‐tube nozzle with an inlet diameter of 10 mm, conical transition pipe length of 3 mm, nozzle outlet diameter of 0.8 mm, curvature radius of 4 mm, and central angle of curved tube of 30°, can effectively enhance the outlet velocity of spinning solution. Finally, it is proved by centrifugal spinning experiment that the curved‐tube nozzle after optimization can improve the morphology and quality of nanofibers.
Anatomical and developmental aspects of iatrogenic injury to the right recurrent laryngeal nerve in surgical resections of substernal goiter
Authors: Fiorelli Rossano Kepler Alvim , Duarte Alfredo Jorge Vasconcelos , de Quadros Teixeira Aline , Montenegro Thiago Scharth , Portari Filho Pedro Eder , Morard Maria Ribeiro Santos , da Silva Ascenção Agostinho Manuel , Oliveira Carlos Alberto Basílio , Novellino Pietro
Published: April 2021

Thyroid surgery is the primary treatment for substernal goiters, and iatrogenic injury to the recurrent laryngeal nerve (RNL) is always a risk. The literature suggests that iatrogenic lesions of the RNL post resection of substernal goiter are not equally distributed, being more frequent on the right recurrent laryngeal nerve (R‐RLN) in comparison to the left recurrent laryngeal nerve (L‐RLN). The relative paucity of basic anatomical and clinical reportages on R‐RLN iatrogenic injuries and on the developmental factors that may help explain its higher incidence justifies this study's undertaking. Here we compare incidence of right versus left iatrogenic injuries to the RLN in surgical resections of substernal goiters and discuss the anatomical and embryological factors involved. This report is part of a larger retrospective observational cohort study of 239 patients surgically treated for substernal goiter in the Gaffrée and Guinle University Hospital, Rio de Janeiro, from 2006 to 2018. From 239 patients, 13 presented with iatrogenic RLN injury, one patient presented bilateral lesion, totalling 15 iatrogenic lesions. Our analysis showed that the R‐RLN seems to be anatomically more vulnerable to injury due to the embryological underpinnings addressed in this review, R‐RLN = 64.29% (n = 9) and L‐RLN = 35.71% (n = 5). Pathological factors like malignancy and size of the mass are relevant issues to be considered. The knowledge of anatomical landmarks and embryological development of the thyroid and associated structures can improve our understanding and teaching of surgical anatomy, thus helping prevent and reduce the number of iatrogenic injuries on right RLNs.
The Integration of Prelaboratory Assignments within Neuroanatomy Augment Academic Performance, Increase Engagement, and Enhance Intrinsic Motivation in Students
Authors: Rao Bhagavathula Venugopala , Bhagavathula Viswakanth , Moinis Rohan S. , Chaudhuri Joydeep Dutta
Published: April 2021

The study of neuroanatomy imposes a significant cognitive load on students since it includes huge factual information and therefore demands diverse learning strategies. In addition, a significant amount of teaching is carried out through human brain demonstrations, due to limited opportunities for cadaveric dissection. However, reports suggest that students often attend these demonstrations with limited preparation, which detrimentally impacts their learning. In the context of student learning, greater levels of engagement and intrinsic motivation (IM) are associated with better academic performance. However, the maintenance of engagement and the IM of students in neuroanatomy is often challenging for educators. Therefore, this study aimed to explore the role of prelaboratory assignments (PLAs) in the improvement of academic performance, augmentation of engagement, and enhancement of IM in occupational therapy students enrolled in a human neuroanatomy course. One cohort of students in the course was expected to complete PLAs prior to each brain demonstration session. The PLAs contained a list of structures, and students were expected to write a brief anatomical description of each structure. Another cohort of students who were not provided with similar PLAs constituted the control group. Students who completed PLAs had a higher score on the final examinations as compared to students who were not required to complete PLAs. These students also demonstrated greater engagement and IM, and indicated that they perceived PLAs to be valuable in the learning of neuroanatomy. Therefore, PLAs represent a useful teaching tool in the neuroanatomy curriculum.
Three‐Dimensional Tooth Models with Pulp Cavity Enhance Dental Anatomy Education
Authors: Sun Wen , Chen Hongyu , Zhong Yi , Zhang Wei , Chu Fengqing , Li Lin , Chen Yue , Wang Xiang , Wang Qirui , Wang Yuxin , Wei Yongyue , Liu Laikui , Xu Yan
Published: April 2021

Dental anatomy is an integrated, core fundamental dental course, which prepares students for all future clinical dental courses. This study aimed to build up an online dental learning platform of micro‐computed tomography‐based three‐dimensional (3D) tooth models with pulp cavity, and to further evaluate its effectiveness for dental anatomy education using a cohort study. First, ninety‐six extracted permanent teeth were scanned by micro‐computed tomography and the enamel, dentine, and pulp cavity of each was distinguished by different grey‐scale intensities using Mimics software. Three‐dimensional images allowed further discrimination and insights into permanent three‐rooted premolars, central tip, and dental diseases including deep caries and wedge‐shaped defects. Furthermore, a second mesiobuccal canal (MB2) in maxillary permanent molar teeth and Vertucci type III root canal configuration in mandibular anterior teeth could be detected using the 3D analytical tool. A digitized 3D tooth model learning platform was implemented. Last, two groups of dental students were assessed to evaluate the effect of 3D models on dental anatomy education. Participants in the Digital group were allowed to use the online dental learning platform freely after class, while the participants in the Traditional group were not. Assessment quizzes showed that participants' scores improved in the Digital group with the use of the learning platform compared with scores in the Traditional group. A questionnaire survey indicated that the participants had a positive attitude toward the 3D models. Thus, adding digital 3D resources to a traditional curriculum may have a positive effect on academic achievements.
Pyrimidinetrione‐imidazoles as a Unique Structural Type of Potential Agents towards Candida Albicans: Design, Synthesis and Biological Evaluation
Authors: Sui Yan‐Fei , Ansari Mohammad Fawad , Zhou Cheng‐He
Published: April 2021

Substantial morbidity and mortality of fungal infections have aroused concerns all over the world, and common Candida spp. currently bring about severe systemic infections. A series of pyrimidinetrione‐imidazole conjugates as potentially antifungal agents were developed. Bioassays manifested that 4‐fluobenzyl pyrimidinetrione imidazole 5 f exerted favorable inhibition towards C. albicans (MIC=0.002 mM), being 6.5 folds more active than clinical antifungal drug fluconazole (MIC=0.013 mM). Preliminary mechanism research indicated that compound 5 f could not only depolarize membrane potential but also permeabilize the membrane of C. albicans. Molecular docking was operated to simulate the interaction mode between molecule 5 f and CYP51. In addition, hybrid 5 f might form 5 f‐DNA supramolecular complex via intercalating into DNA. The interference of membrane and DNA might contribute to its fungicidal capacity with no obvious tendency to induce the resistance against C. albicans. Conjugate 5 f endowed good blood compatibility as well as low cytotoxicity towards HeLa and HEK‐293T cells.