bluuebunny/crossref_metadata_2025 huggingface dataset:
The Infinite Playground
Authors: De Koven Bernard , Gramazio Holly
Published: July 2020

A play-centered invitation to experience the power and delight unlocked by imagination.

Bernard De Koven (1941–2018) was a pioneering designer of games and theorist of fun. He studied games long before the field of game studies existed. For De Koven, games could not be reduced to artifacts and rules; they were about a sense of transcendent fun. This book, his last, is about the imagination: the imagination as a playground, a possibility space, and a gateway to wonder. The Infinite Playground extends a play-centered invitation to experience the power and delight unlocked by imagination. It offers a curriculum for playful learning.

De Koven guides the readers through a series of observations and techniques, interspersed with games. He begins with the fundamentals of play, and proceeds through the private imagination, the shared imagination, and imagining the world—observing, “the things we imagine can become the world.” Along the way, he reminisces about playing ping-pong with basketball great Bill Russell; begins the instructions for a game called Reception Line with “Mill around”; and introduces blathering games—Blather, Group Blather, Singing Blather, and The Blather Chorale—that allow the player's consciousness to meander freely.

Delivered during the last months of his life, The Infinite Playground has been painstakingly cowritten with Holly Gramazio, who worked together with coeditors Celia Pearce and Eric Zimmerman to complete the project as Bernie De Koven's illness made it impossible for him to continue writing. Other prominent game scholars and designers influenced by De Koven, including Katie Salen Tekinbaş, Jesper Juul, Frank Lantz, and members of Bernie's own family, contribute short interstitial essays.

Contributors

Ian Bogost, Stephen Conway, Adriaan de Jongh, Elyon De Koven, Rocky De Koven, Mary Flanagan, Gonzalo Frasca, Tracy Fullerton, Holly Gramazio, Catherine Herdlick, Jesper Juul, Frank Lantz, Colleen Macklin, Celia Pearce, Sebastian Quack, Lee Rush, Katie Salen Tekinbaş, John Sharp, Tassos Stevens, Akira Thompson, Greg Trefry, Douglas Wilson, Zach Wood, Eric Zimmerman
Digital Entrepreneurship in Africa
Authors: Friederici Nicolas , Wahome Michel , Graham Mark
Published: July 2020

The hope and hype about African digital entrepreneurship, contrasted with the reality on the ground in local ecosystems.

In recent years, Africa has seen a digital entrepreneurship boom, with hundreds of millions of dollars poured into tech cities, entrepreneurship trainings, coworking spaces, innovation prizes, and investment funds. Politicians and technologists have offered Silicon Valley–influenced narratives of boundless opportunity and exponential growth, in which internet-enabled entrepreneurship allows Africa to “leapfrog” developmental stages to take a leading role in the digital revolution. This book contrasts these aspirations with empirical research about what is actually happening on the ground. The authors find that although the digital revolution has empowered local entrepreneurs, it does not untether local economies from the continent's structural legacies.

Drawing on a five-year research project, the authors show how entrepreneurs creatively and productively adapt digital technologies to local markets rather than dreaming of global dominance, achieving sustainable businesses by scaling based on relationships and customizing digital platform business models for African infrastructure challenge. The authors examine African entrepreneurial ecosystems; show that African digital entrepreneurs have begun to form a new professional class, becoming part of a relatively exclusive cultural and economic elite; and discuss the impact of Silicon Valley's mythologies and expectations. Finally, they consider the implications of their findings and offer recommendations to policymakers and others.

The open access edition of this book was made possible by generous funding from Arcadia – a charitable fund of Lisbet Rausing and Peter Baldwin and by Knowledge Unlatched.
Factors Influencing Sustainable Agricultural Practices among Smallholder Farmers in Ogun State of Nigeria
Authors: Oyewole Samuel Olusola , Sennuga Samson Olayemi
Published: July 2020

The importance of adopting Sustainable Agricultural Practices (SAPs) approach to improve food production cannot be overemphasized in policy development and research agenda of many countries in sub-Saharan Africa. This study investigates how socio-demographic factors influence farm-level decision process associated with the adoption of sustainable agricultural practices among smallholder farmers in Ogun State. A multi-stage sampling technique was used to select 196 farmers. Primary data were collected with the aid of structured questionnaires. The data collected were analyzed using descriptive statistics, Likert scale rating and multivariate probit model. The results showed that majority of the farmers were male with mean age of 35 years cultivating an average farm size of 5.8 hectares. The use of improved variety was adopted by 95.41% and this was rank first among the practices adopted by the farmers. Agroforestry was rank second and adopted by 85.71% of the respondents. The extent of adoption by the respondents showed that 94.39 and 72.45 were practicing the use of improved variety and agroforestry regularly. The factors influencing adoption of sustainable practices were age, education, farm size, farming experience and membership of social organization. The result further revealed that young farmers are more likely to adopt sustainable agricultural practices as option to increase productivity and reduce vulnerability of environment to ecological problems. This suggests that campaign for adoption of sustainable agricultural practices should target young farmers. However, this is not to discriminate older farmers in the sustainable agriculture policy agenda. The study established that there are complementary and substitute effects between the sustainable agricultural practices. This showed that policy changes that affect adoption of a given practice can have spillover effect on the other. Hence, extension services and promotion agenda should always emphasize the effects between different practices to enhance farmers’ choice.
Agronomic Performance of Corn Cultivars as a Function of Phosphorus Use
Authors: Maciel Lucas Carneiro , Santos Weder Ferreira dos , Peluzio Joênes Mucci , Junior Osvaldo José Ferreira , Barbosa Adriano Silveira , Silva Rafael Marcelino da , Sodré Layanni Ferreira , Oliveira Magno De
Published: July 2020

Aims: The research was carried out to evaluate the agronomic performance of corn cultivars in contrasting phosphorus environments in the state of Pará, Brazil.

Study Design: The experimental design was randomized blocks with ten treatments and three replications. The treatments were composed of ten cultivars: AG 1051, AG 8088PRO2, BR 206, BRS 3046, PR 27D28, 2B655PW, AL BANDEIRANTE, ANHEMBI, CATIVERDE 02 and ORION

Place and Duration of Study: In the 2017/18 crop, two competition trials of corn cultivars were carried out at Sítio Vitória, municipality of Santa Maria das Barreiras, state Pará, Brazil.

Methodology: Two competition trials of corn (Zea mays L.) cultivars were carried out under contracting conditions of phosphorus: high P (100 kg ha-1 of P2O5) and low P (50 kg ha-1 of P2O5), using simple superphosphate (18% P2O5) as the source. The agronomic efficiency of phosphorus use was obtained by the difference between grain yield in both levels, divided by the difference between doses. The variables evaluated were: ear height, plant height, ear diameter, number of rows per year, number of grains per rows and grain yield.

Results: The mean grain yield of the cultivars ranged from 5,446 kg ha-1 (low P) to 11,486 kg ha-1 (high P), and the means of all cultivars were higher in high P. The means agronomic efficiency ranged from 25.1 kg kg-1 (AL BANDEIRANTE) to 96.6 kg kg-1 (AG 1051).

Conclusion: The highest phosphorus dose (100 kg ha-1 of P2O5) resulted in higher values in the variables studied. The cultivars that stood out the most, under high and low phosphorus, were AG 8088PRO2, AG 1051 and BRS 3046, the last two being agronomically efficient.
Comparative Study between the Effect of Perineural versus Intravascular Dexmedetomidine in Ultrasound-Guided Supraclavicular Brachial Plexus Block
Authors: Mohasseb Mahmoud A. Al , Messbah Wael E. , Amin Sabry M. , Fattooh Nadia H.
Published: July 2020

Background: Augmentation of postoperative analgesia with various adjuvants has become a standard in regional anesthesia. There are no studies about dexmedetomidine multiple approaches in supraclavicular brachial plexus block (BPB) was contrasted. We compare perineural dexmedetomidine and intravenous dexmedetomidine Bupivacaine as adjuvant in supraclavicular brachial plexus block.

Materials and Methods: This prospective randomized controlled double-blind study was conducted on 120 patients with age between 20 and 60 years, both sexes, scheduled for elective upper limb surgery. Patients were randomly allocated into 3 groups, 40 patients in each received plain bupivacaine 0.5% (20 ml) in supraclavicular BPB; group I (Control group): add 1 mL normal saline perineural, group II: Bupivacaine with perineural dexmedetomidine (BDP) add 1 μg.kg-1dexmedetomidine perineurally. group III: Bupivacaine with intravenous dexmedetomidine (BDV) add 0.5 μg.kg-1 dexmedetomidine in 50 mL of normal saline administered as infusion over 10 min. Onset and duration of sensory and motor blocks, hemodynamic variables, adverse effects, and duration of analgesia were assessed.

Results: Heart rate and mean arterial pressure was significantly decrease in group III &group II compared to group I were compared by ANOVA (F) test. onset of sensory &motor block was statistically significant shorter in group II compared to group I & III. Duration of sensory &motor block was statistically significant longer in group II compared to group I & III. there was statistically significant decrease VAS in group II were analysed using Kruskal-Wallis test between three groups. There was statistically significant increase RSS in group II & III. The first time of analgesic request was statistically significant prolonged in duration in group II.

Conclusion: Perineural dexmedetomidine (1 µg/ kg) as an adjuvant to bupivacaine is significantly high thanIV dexmedetomidine (0.5 µg/ kg) and bupivacaine alone in supraclavicular BPB as regards to the onset and the duration of sensory block, so Increasingpostoperative analgesia.
Farmers’ Information Literacy and Productivity Performance of Smallholder Horticulture in a Highland Zone, Kenya
Authors: Sang Nelly Chebet , Cheruiyot Joseph Kipkorir
Published: July 2020

The horticulture sub-sector contributes substantially to the Kenyan economy, but smallholder productivity is low. This study investigated the role of information literacy on smallholder horticultural productivity performance in a lower highland zone of Belgut Sub-county, Kericho County, Kenya. The study used descriptive cross-sectional survey design. Data were collected between January and April 2019. Smallholder horticulture farmers who previously participated in a program; NALEP, in Belgut Sub-county were purposely selected and interviewed. Data was collected from 31 respondents through face-to-face household interviews using pre-tested semi-structured interview schedules and analyzed using Statistical Package for Social Sciences (SPSS) version 20. Descriptive statistics were utilized to document the farmers’ information sources. Associations between attributes were analyzed by running Goodman and Kruskals’ gamma and Somers’ d. Findings indicated that the smallholder horticulture farmers obtained horticultural information mostly from the public extension, but also from private companies, NGOs/FBOs, mass media, and other farmers. Farmers’ level of formal education, organizational skills, accounting, and farming skills; as indicators of information literacy, showed moderate strength of relationship with productivity and profitability (Gamma = 0.200 to 0.563) but showed mixed strength with horticultural produce quality (Gamma = 0.138 to 0.948).Somers delta showed similar patterns (Somers d = 0.089 to 0.684). When the four indicators of information literacy were amalgamated into an information literacy score, there was evidence of a moderate strength monotonic relationship between information literacy and performance as measured by the Spearman rank correlation; rs (29) = .571, P = .001.The study concludes that farmers obtain horticultural information from diverse sources. Information literacy contributes to the productivity and profitability of smallholder horticulture. Capacity building of the farmers on information literacy is recommended.
DIFICULDADES INSTITUCIONAIS E ECONÔMICAS PARA O ORÇAMENTO PARTICIPATIVO EM MUNICÍPIOS BRASILEIROS
Authors: Dias Peres Ursula
Published: July 2020

Este artigo faz parte de uma agenda de pesquisa que tem origem na abordagem institucional e na economia política do orçamento público para a construção de modelo de análise da governança orçamentária em cidades brasileiras. O objetivo do artigo é analisar o processo de participação e conflito distributivo inerente ao orçamento público partindo de evidências dos municípios brasileiros no período de 2005 a 2018. Este texto apresenta reflexões iniciais sobre os limites para a realização do Orçamento Participativo decorrentes da crescente setorialização de gastos, da estrutura de receitas municipais e da crise de financiamento nos municípios, principalmente, a partir de 2014, que têm infligido dificuldades para a construção de uma arena coletiva para participação e negociação do conflito distributivo.

 

INSTITUTIONAL AND ECONOMIC DIFFICULTIES FOR PARTICIPATORY BUDGETING IN BRAZILIAN MINICIPALITIES

This article is part of a research agenda based on the institutional approach and the political economy of public budgeting to develop an analyticalframeworkfor the budgetary governance in Brazilian cities. The article aims to understand the participatory and distributive conflict inherent to the public budgeting,based on evidence from Brazilian municipalities from 2005 to 2018. This paper presents initial remarks on the limits to the Participatory Budgeting arising from the growing sectorization of spending, the structure of municipal revenues and the fiscal crisis in the municipalities, especially since 2014, which have complicated the construction of a collective arena for participation and negotiation of distributive conflict.

Keywords: Public budgeting, Local government, Distributive conflict, Participatory budgeting, Municipalities.

 

DIFFICULTÉS INSTITUTIONNELLES ET ÉCONOMIQUES POUR LA BUDGÉTISATION PARTICIPATIVE DANS LESMUNICIPALITÉS BRÉSILIENNES

Cet article a pour origine un programme de recherche issu de l’approcheinstitutionnelle et de l’économie politique du budget public pour la construction d’un modèled’analyse de la gouvernancebudgétaire des villesbrésiliennes. L’objectif de cet article est de comprendre le processus de participation et les conflits de répartition intrinsèques au budget public à partir des informations financières des municipalités brésiliennes entre 2005 et 2018. Cet étude présente des réflexions initiales à propos des limites de la budgétisation participative suite à la croissante spécialitébudgétairedes dépenses, à la structure de recettes municipales et à la crise du financement municipal, en particulier depuis 2014, qui brident la construction d’un espace collectif de participation et de négociation des conflits distributifs.

Mots clés: Budget public; Gouvernement local, Conflit distributif, Budget publique, Budgétisation participative, Municipalités.
Apresentação
Authors: Marcelino Douglas Attila
Published: July 2020

Morte, poder e política.
Editorial
Authors: Rodrigues Claudia , Nascimento Mara Regina do
Published: July 2020

A Revista M. chega ao seu quarto número trazendo aos leitores o Dossiê temático As celebrações da morte na Antiguidade, organizado pela professora Luciane Munhoz  de  Omena,  da  Universidade  Federal  de Goiás, e pelos professores Darío N. Sánchez Vendramini e Pedro Paulo A. Funari, respectivamente, da Universidade Nacional de Córdoba/Argentina, e da Universidade Estadual de Campinas. O foco privilegiado do Dossiê recai desta vez sobre os estudos das representações da morte entre as sociedades do mundo antigo, notadamente o universo romano. Entram em cena no conjunto de artigos publicados os modos de expressão e da vivência da morte nas narrativas literárias e nos poemas épicos, nas práticas dos jogos e cortejos civis, na cultura religiosa e tramas políticas e, ainda, nos suicídios aristocráticos.
Apresentação
Authors: Omena Luciane Munhoz de , Vendramini Darío N. Sánchez , Funari Pedro Paulo A.
Published: July 2020

As celebrações da morte na Antiguidade.
Os funerais heroicos e a celebração dos mortos na Eneida de Virgílio: uma abordagem das práticas mortuárias na Antiguidade Romana
Authors: Mota Thiago Eustáquio Araújo
Published: July 2020

Neste artigo abordamos a ritualização da morte em Roma, a partir dos funerais heroicos descritos na Eneida de Virgílio, tendo em vista as relações entre morte e memória. O recorte cronológico deste estudo compreende sobretudo o século I a.C. Problematizamos os tabus religiosos romanos e os riscos de polução relativos à presença do cadáver, assim como os danos representados pelo morto insepulto. Analisamos as várias etapas do funus, desde a toalete do morto até a deposição no sepulcro e a instituição do culto aos manes do falecido pela família.
Dossiê Temático Morte
Authors: Rodrigues Claudia , Nascimento Mara Regina do
Published: July 2020

É com muita satisfação que a Revista M. chega ao seu quinto número, trazendo aos leitores e às leitoras o Dossiê Temático Morte, regimes políticos e violência, organizado pela professora da área de História Sandra Gayol, da Universidad Nacional de General Sarmiento-UNGS, e pelo professor da área de Sociologia Gabriel Kessler, da Universidad Nacional de La Plata.
Del punitivismo carcelario a la matanza sistemática: El avance de los operativos militarizados en la era post-Chávez
Authors: Zubillaga Verónica , Hanson Rebecca
Published: July 2020

Este ensayo, basado en dos investigaciones cualitativas en curso, plantea que para comprender el aumento reciente de las muertes violentas en Venezuela y específicamente en Caracas en el período post Chávez, tenemos que colocar en el centro del análisis los discursos y las prácticas de un actor privilegiado como lo es el Estado, en un contexto de colapso de los precios petroleros. Se propone que esta inusitada violencia letal puede ser comprendida por el  impacto  que  ha  ocasionado,  dentro del histórico proceso de militarización de la seguridad ciudadana, un punitivismo carcelario que con el pasar de los años ha venido abriendo el paso y yuxtaponiéndose a una práctica de matanza sistemática extralegal implicada en la extrema violencia policial y militar de operativos militarizados focalizados en los sectores pobres. Esta avanzada militar, se puede decir, forma parte del avance de una necropolítica en el país en tiempos de Revolución Bolivariana post-Chavista.
O morto no lugar dos mortos: classificações, sistemas de controle e necropolítica no Rio de Janeiro
Authors: Santos Flavia Medeiros
Published: July 2020

Neste artigo apresento reflexões elaboradas a partir das etnografias que realizei em instituições policiais que atuam na gestão de mortes e mortos na região metropolitana do Rio de Janeiro/Brasil entre 2010 a 2014. Particularmente, apresento dados produzidos no âmbito do Instituto Médico-Legal e da Divisão de Homicídios para demonstrar como a violência que produz mortos é tratada pelos mecanismos de classificação e poder mobilizados por um estado, através de suas instituições policiais. Por práticas, burocracias e moralidades, demonstro como agentes policiais organizam um regime necropolítico presente, tanto pela centralidade da morte no cotidiano dos sujeitos e instituições quanto na multiplicidade de tempos e espacialidades que os mortos constituem. Neste sentido, abordo o papel do controle estatal da vida social dos mortos, para discutir o que os mortos alvo da violência submetidos a essa política de morte podem vir a produzir.
Editorial
Authors: Rodrigues Claudia , Nascimento Mara Regina do
Published: July 2020

Esse sexto número de nossa Revista M. apresenta o Dossiê Temático Arqueologia Funerária: Performance, Morte e Corpo, organizado pelos historiadores Adriene Baron Tacla, da Universidade Federal Fluminense, e Pedro Vieira da Silva Peixoto, vinculado à Universidade Federal do Rio de Janeiro.
Cruzar oceanos para salvar almas
Authors: Martins William De Souza
Published: July 2020

Resenha do livro: SÁ, Isabel dos Guimarães. O regresso dos mortos: os doadores da Misericórdia do Porto e a expansão oceânica (séculos XVI-XVII). Lisboa: Imprensa de Ciências Sociais, 2018. 331 p.
Suicídio por contágio e o papel das mídias de comunicação em massa
Authors: Kovács Maria Júlia , Hwang Esther
Published: July 2020

Este artigo tem como objetivo (i) explorar, em termos gerais, a temática do suicídio por contágio e o papel dos meios de comunicação em massa nesse fenômeno; (ii) investigar, em termos mais específicos, a possibilidade de suicídios por contágio em conexão com (a) suicídios de celebridades e (b) suicídios em espaços públicos em que são registrados altos índices de morte voluntária; e (iii) propor reflexões sobre a prevenção do suicídio no que diz respeito à atuação das mídias de comunicação em massa. Para tanto, utilizamos o método da revisão bibliográfica e uma pesquisa de campo. Observa-se que a simples exposição do tema do suicídio na mídia não causa diretamente suicídios subsequentes, embora possa ser um fator de influência, dependendo da abordagem. O suicídio por contágio está associado ao processo de identificação e imitação, à influência sócio-histórica-cultural dos locais, dos métodos e do próprio ato suicida influenciador, sendo imprescindível refletir sobre os meandros da relação pessoa-ambiente para a elaboração de medidas preventivas.
Effect of implementing an overwork-prevention act on working hours and overwork-related disease: A mediation analysis
Authors: Lin Ro-Ting , Liang Ying-Wen , Takahashi Masaya , Eguchi Hisashi , Tsutsumi Akizumi , Lin Sheng-Hsuan
Published: July 2020

Objectives

Overwork has been recognized as a risk factor for cerebrovascular and cardiovascular disease (CCVD). To our best knowledge, Japan is the first country in the world to implement an independent act (the 2014 Act) for the prevention of overwork-related disease, which was promoted through application of preventive measures, such as reductions in working hours. We assessed changes in working hours and overwork-related CCVD before and after introduction of the 2014 Act.

Methods

We calculated the overwork-related CCVD incidence rate and average monthly working hours for 10 industry groups in Japan with data from 2012 to 2018. We applied a causal mediation analysis to estimate the total effect of implementing the 2014 Act on the overwork-related CCVD and the effect mediated by working hours.

Results

An average of 271 for every 48 million employees developed overwork-related CCVD per year. After introducing the 2014 Act, the incidence rate ratio of overwork-related CCVD was 0.881-fold lower (95% CI 0.780-0.995) compared with before the policy change. The 2014 Act contributed to a decrease of 26% (78 cases per year; 95% CI 29-173) of the overwork-related CCVD incidence per year. Approximately 41% (32 cases per year) of this effect could be explained by reduced working hours.

Conclusions

Our study highlights the impact of the 2014 Act in Japan on the reduction in working hours, which further contributes to the reduction in overwork-related CCVD. Policymakers should consider adopting our innovative approach to assess the mediation effect underlying the implementation of new policies.
A moderated mediation analysis of occupational stress, presenteeism, and turnover intention among occupational therapists in Korea
Authors: Chun Byung-Yoon , Song Chiang-Soon
Published: July 2020

Objectives

Presenteeism is undoubtedly a widespread phenomenon in organizations. Research on presenteeism has been conducted for decades in the broader workforce (eg, nurses, doctors, teachers, police officers). Occupational stress and turnover intention in occupational therapy have been extensively studied. However, the effect of presenteeism on the relationship between occupational stress and resultant turnover intention among occupational therapists is unclear. This study aims to explore the mediating effect of presenteeism and moderating effect of perceived organizational support in the relationship between occupational stress and turnover intention among occupational therapists in Korea.

Methods

We conducted an individual and cross-sectional analysis of 257 occupational therapists from various health care institutions in Korea. Data were collected and hypotheses were tested via Process macro. Quantitative analyses were conducted with SPSS 26 and LISREL 8.54.

Results

Occupational stress was strongly related to presenteeism, which in turn predicted turnover intention. Presenteeism played a mediating role between occupational stress and turnover intention. Moreover, occupational therapists’ perception of organizational support acted as an important mechanism through which presenteeism mediated the relationship between occupational stress and turnover intention.

Conclusions

This study highlights the need to maximize employee productivity and retain talent by providing managers with insight into the mechanism of presenteeism in relation to occupational stress and turnover intention among occupational therapists in Korea.
ELT Management and Leadership Training
Authors: Quirke Phil
Published: July 2020

A decade ago, I wrote: “All too often in educational management we see quality teaching struggle against administrative and paperwork constraints.” Despite technological advances that should have simplified administrative tasks and reduced paperwork load, we are faced with an ever‐increasing volume of data that must be collated, analysed, interpreted, and reported on. Teachers are finding that increasing numbers of what were previously considered management and leadership roles are now part of their professional responsibilities, and the constraints on quality teaching and learning are tightening rather than relaxing. This author would argue there is still little training and development for teachers that specifically focuses on these management and leadership roles. This entry aims to address this by presenting one educational management and leadership professional development course that has been run successfully for over a decade.
Research of the Micropores and Maximum Temperature of a New Type of Nickel‐Based Single Crystal Superalloy during Homogenization
Authors: Li Yiling , Jia Zhihong , Lu Yuanyong , Liang Xiangfeng , Tang Wei , Fu Hao , Jing Wenxiang , Ji Jiaming , Xu Weitai , Zhao Yutao , Zou Zhengyang
Published: July 2020

Herein, the cause and change of micropores, the cause of the incipient melting structures, and the increase of the maximum homogenization temperature of a nickel‐based single crystal (SC) superalloy during homogenization are researched. The results show that the micropores are generated because of unbalanced diffusion during homogenization and form incipient melting structures at high temperature because of the lack of rhenium (Re) and tungsten (W). With the diffusion of Re and W, the porosity is decreased from 0.169% to 0.06% and cannot be further decreased because of the existence of shrinkage pores, the maximum homogenization temperature is increased to more than 1350 °C, and the rupture life at 1100 °C/150 MPa is improved to 217 h.
Principles Governing Control of Aggregation and Dispersion of Graphene and Graphene Oxide in Polymer Melts
Authors: Suter James L. , Sinclair Robert C. , Coveney Peter V.
Published: July 2020

Controlling the structure of graphene and graphene oxide (GO) phases is vitally important for any of its widespread intended applications: highly ordered arrangements of nanoparticles are needed for thin‐film or membrane applications of GO, dispersed nanoparticles for composite materials, and 3D porous arrangements for hydrogels. By combining coarse‐grained molecular dynamics and newly developed accurate models of GO, the driving forces that lead to the various morphologies are resolved. Two hydrophilic polymers, poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVA), are used to illustrate the thermodynamically stable morphologies of GO and relevant dispersion mechanisms. GO self‐assembly can be controlled by changing the degree of oxidation, varying from fully aggregated over graphitic domains to intercalated assemblies with polymer bilayers between sheets. The long‐term stability of a dispersion is extremely important for many commercial applications of GO composites. For any degree of oxidation, GO does not disperse in PVA as a thermodynamic equilibrium product, whereas in PEG dispersions are only thermodynamically stable for highly oxidized GO. These findings—validated against the extensive literature on GO systems in organic solvents—furnish quantitative explanations for the empirically unpredictable aggregation characteristics of GO and provide computational methods to design directed synthesis routes for diverse self‐assemblies and applications.
Photoactivation Strategies for Therapeutic Release in Nanodelivery Systems
Authors: Choi Seok Ki
Published: July 2020

Control of therapeutic release constitutes one of most critical aspects considered in the design of nanoscale delivery systems. There are a variety of cellular factors and external stimuli employed for release control. Of these, use of light offers various photoactivation mechanisms that enable to effectively engage in therapeutic release. It also allows a higher degree of spatial and temporal control. Over recent decades, the application of photoactivation strategies has seen remarkable growth and made a significant impact on rapid advances in the field of drug delivery. This Review aims to summarize the fundamental concepts and practical applications demonstrated recently in numerous therapeutic areas from cancers to infectious diseases. Its scope is defined by a focus on those photoactivation strategies that occur via either linker cleavage, nanocontainer gating, or disassembly. Each of these is discussed with specific examples and underlying mechanisms that comprise linker photolysis, photoisomerization, photothermal heating, or photodynamic reactions with reactive oxygen species. In summary, this Review provides an inclusive summary of new developments and insights obtained from recent progress in photoactivation strategies and their applications in therapeutic nanodelivery.
Stamping Fabrication of Flexible Planar Micro‐Supercapacitors Using Porous Graphene Inks
Authors: Li Fei , Qu Jiang , Li Yang , Wang Jinhui , Zhu Minshen , Liu Lixiang , Ge Jin , Duan Shengkai , Li Tianming , Bandari Vineeth Kumar , Huang Ming , Zhu Feng , Schmidt Oliver G.
Published: July 2020

High performance, flexibility, safety, and robust integration for micro‐supercapacitors (MSCs) are of immense interest for the urgent demand for miniaturized, smart energy‐storage devices. However, repetitive photolithography processes in the fabrication of on‐chip electronic components including various photoresists, masks, and toxic etchants are often not well‐suited for industrial production. Here, a cost‐effective stamping strategy is developed for scalable and rapid preparation of graphene‐based planar MSCs. Combining stamps with desired shapes and highly conductive graphene inks, flexible MSCs with controlled structures are prepared on arbitrary substrates without any metal current collectors, additives, and polymer binders. The interdigitated MSC exhibits high areal capacitance up to 21.7 mF cm−2 at a current of 0.5 mA and a high power density of 6 mW cm−2 at an energy density of 5 µWh cm−2. Moreover, the MSCs show outstanding cycling performance and remarkable flexibility over 10 000 charge–discharge cycles and 300 bending cycles. In addition, the capacitance and output voltage of the MSCs are easily adjustable through interconnection with well‐defined arrangements. The efficient, rapid manufacturing of the graphene‐based interdigital MSCs with outstanding flexibility, shape diversity, and high areal capacitance shows great potential in wearable and portable electronics.
Produced water's impact on soil properties: Remediation challenges and opportunities
Authors: Green A. , DeSutter T.M. , Meehan M.A. , Daigh A.L.M. , O'Brien P.L.
Published: July 2020

The choice of remediation of oil‐produced water (aka brine) spills depends on the severity of contamination, environmental factors, cost‐effectiveness, and relative efficiency of salt removal. The objective of this review is to summarize the current practices that are used to remediate brine spills or abandoned evaporation pits within the Bakken and Three Forks regions of the Williston Basin within the upper Great Plains. The most common current methods are “dig and haul” and the use of chemical amendments such as gypsum (CaSO4) or organic amendments (manure, straw, etc.) to promote soil flocculation and the downward leaching of salts out of the topsoil. These methods, however, can fail to achieve sustained remediation success in a cost‐effective and timely manner, making continued research into alternative methods necessary. The use of electrokinetics, crystallization inhibitors, wicking materials, and plant‐growth promoting rhizobacteria hold promise for in‐situ cleanup of contaminated sites.
Dry matter and nutrient partitioning changes for the past 30 years of cotton production
Authors: Pabuayon Irish Lorraine B. , Lewis Katie L. , Ritchie Glen L.
Published: July 2020

Modern cotton (Gossypium hirsutumL.) cultivars are more productive and have unique growth and fruiting characteristics due to optimization of genetics and management practices in the past 30 yr. The most recent work evaluating nutrient uptake and partitioning by cotton was conducted in the early 1990s, necessitating a re‐evaluation of nutrient accumulation and requirements in modern high productivity cultivars. Modern cultivar (FiberMax [FM] 958 and Deltapine [DP] 1646) resource allocation, including dry matter production, yields, and accumulation and partitioning of N, P, K, Ca, Mg, and S to different organs, was compared with that of a 1990s cultivar (Paymaster [PM] HS26) in 2018 and 2019. The modern cultivars tested in this study partitioned a greater percentage of dry matter, N, P, K, and S into the fruit than the older cultivar, highlighting the importance of partitioning for increased production potential of these cultivars from the 1990s to the 2010s. Greater efficiencies in partitioning and remobilization of N, P, K, and S resulted in 66, 88, 64, and 30% increase in the amount of lint yield produced for every unit of uptake, respectively, under favorable growing conditions. These findings suggest that existing fertility paradigm in cotton may underestimate the accumulation expectations during the middle and latter part of the growing season. These results can be a basis for optimizing nutrient application to address partitioning changes. Adjusting nutrient recommendations to the shift in cultivar growth characteristics may improve both yield and application efficiency of fertilizers.
Tumor‐Triggered Disassembly of a Multiple‐Agent‐Therapy Probe for Efficient Cellular Internalization
Authors: Yang Juliang , Dai Jun , Wang Quan , Cheng Yong , Guo Jingjing , Zhao Zujin , Hong Yuning , Lou Xiaoding , Xia Fan
Published: July 2020

Integration of multiple agent therapy (MAT) into one probe is promising for improving therapeutic efficiency for cancer treatment. However, MAT probe, if entering the cell as a whole, may not be optimal for each therapeutic agent (with different physicochemical properties), to achieve their best performance, hindering strategy optimization. A peptide‐conjugated‐AIEgen (FC‐PyTPA) is presented: upon loading with siRNA, it self‐assembles into FCsiRNA‐PyTPA. When approaching the region near tumor cells, FCsiRNA‐PyTPA responds to extracellular MMP‐2 and is cleaved into FCsiRNA and PyTPA. The former enters cells mainly by macropinocytosis and the latter is internalized into cells mainly through caveolae‐mediated endocytosis. This two‐part strategy greatly improves the internalization efficiency of each individual therapeutic agent. Inside the cell, self‐assembly of nanofiber precursor F, gene interference of CsiRNA, and ROS production of PyTPA are activated to inhibit tumor growth.
Iodane‐Guided ortho C−H Allylation
Authors: Chen Wei W. , Cunillera Anton , Chen Dandan , Lethu Sébastien , López de Moragas Albert , Zhu Jun , Solà Miquel , Cuenca Ana B. , Shafir Alexandr
Published: July 2020

A metal‐free C−H allylation strategy is described to access diverse functionalized ortho‐allyl‐iodoarenes. The method employs hypervalent (diacetoxy)iodoarenes and proceeds through the iodane‐guided “iodonio‐Claisen” allyl transfer. The use of allylsilanes bearing electron‐withdrawing functional groups unlocks the functionalization of a broad range of substrates, including electron‐neutral and electron‐poor rings. The resulting ortho‐allylated iodoarenes are versatile building blocks, with examples of downstream transformation including a concise synthesis of the experimental antimitotic core of Dosabulin. DFT calculations shed additional light on the reaction mechanism, with notable aspects including the aromatic character of the transition‐state structure for the [3,3] sigmatropic rearrangement, as well as the highly stereoconvergent nature of the trans‐product formation.
Optical Control of a CRISPR/Cas9 System for Gene Editing by Using Photolabile crRNA
Authors: Zhang Yu , Ling Xinyu , Su Xiaoxuan , Zhang Shilin , Wang Jing , Zhang Pingjing , Feng Wenjian , Zhu York Yuanyuan , Liu Tao , Tang Xinjing
Published: July 2020

Currently CRISPR/Cas9 is a widely used efficient tool for gene editing. Precise control over the CRISPR/Cas9 system with high temporal and spatial resolution is essential for studying gene regulation and editing. Here, we synthesized a novel light‐controlled crRNA by coupling vitamin E and a photolabile linker at the 5′ terminus to inactivate the CRISPR/Cas9 system. The vitamin E modification did not affect ribonucleoprotein (RNP) formation of Cas9/crRNA/tracrRNA complexes but did inhibit the association of RNP with the target DNA. Upon light irradiation, vitamin E‐caged crRNA was successfully activated to achieve light‐induced genome editing of vascular endothelial cell‐growth factor A (VEGFA) in human cells through a T7E1 assay and Sanger sequencing as well as gene knockdown of EGFP expression in EGFP stably expressing cells. This new caging strategy for crRNA could provide new methods for spatiotemporal photoregulation of CRISPR/Cas9‐mediated gene editing.
Highly Cooperative Photoswitching in Dihydropyrene Dimers
Authors: Liesfeld Pauline , Garmshausen Yves , Budzak Simon , Becker Jonas , Dallmann André , Jacquemin Denis , Hecht Stefan
Published: July 2020

We present a strategy to achieve highly cooperative photoswitching, where the initial switching event greatly facilitates subsequent switching of the neighboring unit. By linking donor/acceptor substituted dihydropyrenes via suitable π‐conjugated bridges, the quantum yield of the second photochemical ring‐opening process could be enhanced by more than two orders of magnitude as compared to the first ring‐opening. As a result, the intermediate mixed switching state is not detected during photoisomerization although it is formed during the thermal back reaction. Comparing the switching behavior of various dimers, both experimentally and computationally, helped to unravel the crucial role of the bridging moiety connecting both photochromic units. The presented dihydropyrene dimer serves as model system for longer cooperative switching chains, which, in principle, should enable efficient and directional transfer of information along a molecularly defined path. Moreover, our concept allows to enhance the photosensitivity in oligomeric and polymeric systems and materials thereof.
Synthetic Tailoring of Graphene Nanostructures with Zigzag‐Edged Topologies: Progress and Perspectives
Authors: Liu Junzhi , Feng Xinliang
Published: July 2020

Experimental and theoretical investigations have revealed that the chemical and physical properties of graphene are crucially determined by their topological structures. Therefore, the atomically precise synthesis of graphene nanostructures is essential. A particular example is graphene nanostructures with zigzag‐edged structures, which exhibit unique (opto)electronic and magnetic properties owing to their spin‐polarized edge state. Recent progress in the development of synthetic methods and strategies as well as characterization methods has given access to this class of unprecedented graphene nanostructures, which used to be purely molecular objectives in theoretical chemistry. Thus, clear insight into the structure–property relationships has become possible as well as new applications in organic carbon‐based electronic and spintronic devices. In this Minireview, we discuss the recent progress in the controlled synthesis of zigzag‐edged graphene nanostructures with different topologies through a bottom‐up synthetic strategy.
Preparing Pd catalysts based on urea ligand via electrospinning for Suzuki–Miyaura cross‐coupling reactions
Authors: Bao Guangyang , Fan Xiaoye , Xu Tong , Li Chunping , Bai Jie
Published: July 2020

Pd‐catalyzed Suzuki–Miyaura cross‐coupling (SMC) reactions are important in chemistry. In this work, using electrospinning technology, we prepared a novel type of composite catalyst with ligand structures such as urea‐Pd/PAN (polyacrylonitrile) and used them to catalyze SMC reactions in nontoxic systems and “green” conditions (air atmosphere, low temperature, and short reaction time). This method of preparing hybrid materials is simple and easy to operate. The higher catalytic activity of the catalysts is attributed to active centers with rich electrons transferred from ligands with unique structures, which can decrease the activation energy of the rate‐determining step (oxidative addition). In addition, urea‐Pd/PAN composite catalysts exhibit higher catalytic performance than those reduced by H2 because of the smaller size of active species and the more‐efficient oxidative addition to Pd0–ligand complexes compared to Pd0.
A new protocol for assessing the conservation priority of groundwater‐dependent ecosystems
Authors: Fattorini Simone , Fiasca Barbara , Di Lorenzo Tiziana , Di Cicco Mattia , Galassi Diana M. P.
Published: July 2020

Species of conservation concern are usually considered important elements in site prioritization for biodiversity conservation. To overcome the lack of information on species conservation status, multidimensional measures of species rarity can be used as proxies of species vulnerability.

Under this assumption, a two‐step protocol for site prioritization of aquatic groundwater‐dependent ecosystems is proposed using invertebrate vulnerability estimated from species' traits. In the first step, each species occurring in the sites of interest are scored according to their vulnerability. In the second step, sites are prioritized using species' scores.

Species vulnerability scores are based on five dimensions, for which various traits are scored: (i) geography, (ii) ecology, (iii) biology, (iv) population, and (v) evolutionary history. For each species, the scores of the various traits belonging to the same dimension are multiplied to obtain a synthetic score. These scores are then ranked into four classes and, for each dimension, each species receives a new score that reflects its rank. The sum of these scores represents the species' overall score.

Site conservation priorities are assessed by combining species scores into three indices: Sum of Species Scores, Biodiversity Conservation Concern (which relates the sum of species scores with the local species richness) and Groundwater Biodiversity Concern (which is the average of the former two). The protocol is illustrated using case studies in Italy and it is fully implemented in the software AQUALIFE which is freely available at:http://app.aqualifeproject.euby registered users.

Sensitivity analyses showed that the protocol is robust against the lack of information on species biology or sampling limitations. However, trait scoring rests with the user, who must be familiar with the study group.

This approach can be applied at any spatial scale and to different types of aquatic groundwater‐dependent ecosystems.
Phenoxazine‐based Near‐infrared Fluorescent Probes for the Specific Detection of Copper (II) Ions in Living Cells
Authors: Shen Yang , Zheng Wubin , Yao Yusi , Wang Dongmei , Lv Guanglei , Li Chunxia
Published: July 2020

Abstract: It is well known that copper ions play a critical role in various physiological processes. However, a variety of human diseases are tightly correlated with copper overload. Although there are numerous fluorescent probes capable of detecting copper ions, most of them are “turn‐off” probes owing to copper (II) ions fluorescence quenching effect, resulting in poor sensitivity. Herein, a novel “turn‐on” near‐infrared (NIR) fluorescent probe PZ‐N based on phenoxazine was designed and synthesized for the selective detection of copper (II) ions (Cu2+). Upon the addition of Cu2+, the probe could quickly react with Cu2+ and emit strong fluorescence, along with colour change from colourless to obvious blue. Moreover, the probe PZ‐N showed good water solubility, high selectivity, and excellent sensitivity with low limit of detection (1.93 nM) towards copper (II) ions. More importantly, PZ‐N was capable of effectively detecting Cu2+ in living cells.