bluuebunny/crossref_metadata_2025 huggingface dataset:
Enteropathogen antibody dynamics and force of infection among children in low-resource settings
Authors: Arnold Benjamin F , Martin Diana L , Juma Jane , Mkocha Harran , Ochieng John B , Cooley Gretchen M , Omore Richard , Goodhew E Brook , Morris Jamae F , Costantini Veronica , Vinjé Jan , Lammie Patrick J , Priest Jeffrey W
Published: August 2019

Little is known about enteropathogen seroepidemiology among children in low-resource settings. We measured serological IgG responses to eight enteropathogens (Giardia intestinalis, Cryptosporidium parvum, Entamoeba histolytica, Salmonella enterica, enterotoxigenic Escherichia coli, Vibrio cholerae, Campylobacter jejuni, norovirus) in cohorts from Haiti, Kenya, and Tanzania. We studied antibody dynamics and force of infection across pathogens and cohorts. Enteropathogens shared common seroepidemiologic features that enabled between-pathogen comparisons of transmission. Overall, exposure was intense: for most pathogens the window of primary infection was <3 years old; for highest transmission pathogens primary infection occurred within the first year. Longitudinal profiles demonstrated significant IgG boosting and waning above seropositivity cutoffs, underscoring the value of longitudinal designs to estimate force of infection. Seroprevalence and force of infection were rank-preserving across pathogens, illustrating the measures provide similar information about transmission heterogeneity. Our findings suggest antibody response can be used to measure population-level transmission of diverse enteropathogens in serologic surveillance.
Rapid decline of bacterial drug-resistance in an antibiotic-free environment through phenotypic reversion
Authors: Dunai Anett , Spohn Réka , Farkas Zoltán , Lázár Viktória , Györkei Ádám , Apjok Gábor , Boross Gábor , Szappanos Balázs , Grézal Gábor , Faragó Anikó , Bodai László , Papp Balázs , Pál Csaba
Published: August 2019

Antibiotic resistance typically induces a fitness cost that shapes the fate of antibiotic-resistant bacterial populations. However, the cost of resistance can be mitigated by compensatory mutations elsewhere in the genome, and therefore the loss of resistance may proceed too slowly to be of practical importance. We present our study on the efficacy and phenotypic impact of compensatory evolution in Escherichia coli strains carrying multiple resistance mutations. We have demonstrated that drug-resistance frequently declines within 480 generations during exposure to an antibiotic-free environment. The extent of resistance loss was found to be generally antibiotic-specific, driven by mutations that reduce both resistance level and fitness costs of antibiotic-resistance mutations. We conclude that phenotypic reversion to the antibiotic-sensitive state can be mediated by the acquisition of additional mutations, while maintaining the original resistance mutations. Our study indicates that restricting antimicrobial usage could be a useful policy, but for certain antibiotics only.
Reverse engineering approach for improving the quality of mobile applications
Authors: Elsayed Eman K. , ElDahshan Kamal A. , El-Sharawy Enas E. , Ghannam Naglaa E.
Published: August 2019

Background

Portable-devices applications (Android applications) are becoming complex software systems that must be developed quickly and continuously evolved to fit new user requirements and execution contexts. Applications must be produced rapidly and advance persistently in order to fit new client requirements and execution settings. However, catering to these imperatives may bring about poor outline decisions on design choices, known as anti-patterns, which may possibly corrupt programming quality and execution. Thus, the automatic detection of anti-patterns is a vital process that facilitates both maintenance and evolution tasks. Additionally, it guides developers to refactor their applications and consequently enhance their quality.

Methods

We proposed a general method to detect mobile applications’ anti-patterns that can detect both semantic and structural design anti-patterns. The proposed method is via reverse-engineering and ontology by using a UML modeling environment, an OWL ontology-based platform and ontology-driven conceptual modeling. We present and test a new method that generates the OWL ontology of mobile applications and analyzes the relationships among object-oriented anti-patterns and offer methods to resolve the anti-patterns by detecting and treating 15 different design’s semantic and structural anti-patterns that occurred in analyzing of 29 mobile applications. We choose 29 mobile applications randomly. Selecting a browser is not a criterion in this method because the proposed method is applied on a design level. We demonstrate a semantic integration method to reduce the incidence of anti-patterns using the ontology merging on mobile applications.

Results

The proposed method detected 15 semantic and structural design anti-patterns which have appeared 1,262 times in a random sample of 29 mobile applications. The proposed method introduced a new classification of the anti-patterns divided into four groups. “The anti-patterns in the class group” is the most group that has the maximum occurrences of anti-patterns and “The anti-patterns in the operation group” is the smallest one that has the minimum occurrences of the anti-patterns which are detected by the proposed method. The results also showed the correlation between the selected tools which we used as Modelio, the Protégé platform, and the OLED editor of the OntoUML. The results showed that there was a high positive relation between Modelio and Protégé which implies that the combination between both increases the accuracy level of the detection of anti-patterns. In the evaluation and analyzing the suitable integration method, we applied the different methods on homogeneous mobile applications and found that using ontology increased the detection percentage approximately by 11.3% in addition to guaranteed consistency.
On the impact of service-oriented patterns on software evolvability: a controlled experiment and metric-based analysis
Authors: Bogner Justus , Wagner Stefan , Zimmermann Alfred
Published: August 2019

Background

Design patterns are supposed to improve various quality attributes of software systems. However, there is controversial quantitative evidence of this impact. Especially for younger paradigms such as service- and Microservice-based systems, there is a lack of empirical studies.

Objective

In this study, we focused on the effect of four service-based patterns—namely Process Abstraction, Service Façade, Decomposed Capability, and Event-Driven Messaging—on the evolvability of a system from the viewpoint of inexperienced developers.

Method

We conducted a controlled experiment with Bachelor students (N = 69). Two functionally equivalent versions of a service-based web shop—one with patterns (treatment group), one without (control group)—had to be changed and extended in three tasks. We measured evolvability by the effectiveness and efficiency of the participants in these tasks. Additionally, we compared both system versions with nine structural maintainability metrics for size, granularity, complexity, cohesion, and coupling.

Results

Both experiment groups were able to complete a similar number of tasks within the allowed 90 min. Median effectiveness was 1/3. Mean efficiency was 12% higher in the treatment group, but this difference was not statistically significant. Only for the third task, we found statistical support for accepting the alternative hypothesis that the pattern version led to higher efficiency. In the metric analysis, the pattern version had worse measurements for size and granularity while simultaneously having slightly better values for coupling metrics. Complexity and cohesion were not impacted.

Interpretation

For the experiment, our analysis suggests that the difference in efficiency is stronger with more experienced participants and increased from task to task. With respect to the metrics, the patterns introduce additional volume in the system, but also seem to decrease coupling in some areas.

Conclusions

Overall, there was no clear evidence for a decisive positive effect of using service-based patterns, neither for the student experiment nor for the metric analysis. This effect might only be visible in an experiment setting with higher initial effort to understand the system or with more experienced developers.
Serological evidence of hepatitis A, B, and C virus infection in older adults in Khon Kaen, Thailand and the estimated rates of chronic hepatitis B and C virus infection in Thais, 2017
Authors: Posuwan Nawarat , Vuthitanachot Viboonsak , Chinchai Teeraporn , Wasitthankasem Rujipat , Wanlapakorn Nasamon , Poovorawan Yong
Published: August 2019

Hepatitis A (HAV), hepatitis B (HBV), and hepatitis C (HCV) viruses are hepatotropic viruses responsible for acute/chronic hepatitis associated with liver failure, cirrhosis, and hepatocellular carcinoma. Due to the limited data on the prevalence of hepatitis in the older population in Thailand, this study aimed to evaluate the seroprevalence of these viruses in elderly Thais. Using an automated immunoassay, serum samples from individuals older than 60 years of age in Chum Phae district of Khon Kaen province in northeast Thailand were analyzed for anti-HAV (n = 93), HBV markers (n = 460, HBsAg, anti-HBs, and anti-HBc), and anti-HCV (n = 460). Samples were classified into five age groups (61–65, 66–70, 71–75, 76–80, and >80 years). The overall seroprevalence of anti-HAV, HBsAg, anti-HBc, anti-HBs, and anti-HCV was 98.9%, 4.6%, 51.5%, 32.4%, and 1.3%, respectively. When samples were stratified into three groups representing three generations (children/young adults aged 6 months-30 years and middle-aged adults between 31–60 years old from a previous survey, and older adults aged >60 years from the current study), the highest levels of anti-HAV and anti-HBc were found in older adults. Children/young adults had the lowest levels of HBsAg and anti-HCV, and the highest level of anti-HBs. These findings are consistent with the integration of HBV vaccination into the Expanded Program on Immunization (EPI) in 1992 and coincide with increased awareness of blood-borne viral transmission in Thailand. Extrapolating from our data, the estimated numbers of cases of chronic HBV and HCV infection in Thailand in 2017 were 2.2 and 0.79 million, respectively. Thus, effective treatments for viral hepatitis B and C for middle-aged and elderly Thais are needed. This seroprevalence survey could be used to help formulate policies and possible guidelines for treatment and prevention in specific age groups, which is recommended to facilitate the elimination of viral hepatitis by 2030.
Improvement of subsoil physicochemical and microbial properties by short-term fallow practices
Authors: Li Guangyu , de Vries Walter Timo , Wu Cifang , Zheng Hongyu
Published: August 2019

Fallow management can improve the soil nutrients in the topsoil and upper subsoil. However, little is known about the effects of short-term (one year) fallowing with different treatments, such as vegetation and fertilization, on subsoil (20–40 cm) properties. We conducted field trials to explore the changes in subsoil properties in response to such treatments in the Yellow River Delta region in China. Different vegetation and fertilization treatments were applied, and we measured the carbon and nitrogen contents, microbial biomass and microbial community structure in the subsoil. Fallowing without manure resulted in the storage of more total nitrogen (16.38%) than fallowing with manure, and meadow vegetation improved the ammonium nitrogen content (45.71%) relative to spontaneous vegetation. Spontaneous vegetation with manure improved the microbial biomass nitrogen (P < 0.05). Although the impact of short-term fallowing on microbial community structure was low, an effect of management was observed for some genera. Blastopirellula, Lysobacter, and Acidobacteria Gp6 showed significant differences among fallow treatments by the end of the year (P < 0.05). Blastopirellula abundance was related to the microbial biomass nitrogen and nitrogen mineralization rate in the subsoil. Manure retained a high abundance of Lysobacter, which may strengthen soil-borne disease resistance. The response of Acidobacteria Gp6 showed that meadow vegetation without manure may not benefit future crops. Although the treatments did not significantly improve microbial community structure in the one-year period, annual fallowing improved certain subsoil properties and increased the number of functional genera, which may enhance crop productivity in the future.
Trophic upgrading and mobilization of wax esters in microzooplankton
Authors: Roohani Keyana , Haubrich Brad A. , Yue Kai-Lou , D’Souza Nigel , Montalbano Amanda , Rynearson Tatiana , Menden-Deuer Susanne , Reid Christopher W.
Published: August 2019

Heterotrophic protists play pivotal roles in aquatic ecosystems by transferring matter and energy, including lipids, from primary producers to higher trophic predators. Using Oxyrrhis marina as a model organism, changes to the non-saponifiable protist lipids were investigated under satiation and starvation conditions. During active feeding on the alga Cryptomonas sp., the O. marina hexane soluble non-saponifiable fraction lipid profile reflected its food source with the observed presence of long chain mono-unsaturated fatty alcohols up to C25:1. Evidence of trophic upgrading in O. marina was observed with long chain mono-unsaturated fatty alcohol accumulation of up to C35:1. To the best of our knowledge, this is the first evidence that heterotrophic dinoflagellates are capable of producing ester derived alcohols and that dinoflagellates like O. marina are capable of synthesizing fatty alcohols up to C35. Additionally, we show evidence of trophic upgrading of lipids. During a 20-day resource deprivation, the lipid profile remained constant. During starvation, the mobilization of wax esters as energy stores was observed with long chain fatty alcohols mobilized first. Changes in lipid class profile and utilization of wax esters in O. marina provides insight into the types of lipids available for energy demand, the transfer of lipids through the base of marine food webs, and the catabolic response induced by resource deprivation.
Quality Evaluation of Fresh Tomato Stored in Evaporative Coolers
Authors: Balogun A. A. , Ariahu C. C. , Ikya J. K.
Published: August 2019

A study was conducted to assess the performance of evaporative coolers for the storage of fruits and vegetables. Two evaporative coolers [Aluminum-cladded burnt-clay-brick evaporative cooler (ABBEC) and non-cladded burnt-clay-brick evaporative cooler (NBBEC)] for the storage of fruits and vegetables were designed, constructed and tested. The evaporative coolers comprised of double burnt-brick walls (1.29×2.55×2.56 m) external and (1.13×1.27×2.08 m) internal, (L×W×H). The physicochemical, microbiological and sensory attributes of fresh tomatoes stored in the coolers and at ambient were evaluated. Metabolic rates of tomatoes were highest at ambient storage followed by NBBEC with the least value in ABBEC. Beta carotene, ascorbic acid and acidity decreased while total soluble solids, pH and microbial loads increased during storage of tomatoes. Fresh tomatoes stored in ABBEC exhibited lower biochemical and physiological reaction rates hence tissue breakdown, colour changes, pH and titratable acidity were lower in ABBEC than NBBEC and ambient. ABBEC storage further improved the microbial quality and shelf life of fresh tomatoes. The aluminum cladded evaporative cooler was the best storage facility for stop gap extension of shelf life of tomatoes.
Developing Sets of Labour and Wage Rates for Appropriate Remuneration Review toward Improving Delivery of Electricity Power Project in the South Eastern Nigeria
Authors: Felix Ikechukwu, Uche
Published: August 2019

In an effort to address the problem of ineffective power project delivery and poor electricity supply in the south eastern part of Nigeria especially, studies on implications of socio-economic characteristics of the construction skilled labour on effective delivery of electricity in the power sector have reported that remuneration factor among others is very critical for improved electricity power project (EPP) delivery. To confirm the finding, this study therefore investigates the salary and wage rates of the construction professionals and the skilled labour in the government establishments and private firms respectively. Using activity sampling technique, the masonry (block laying) and carpentry trades in the power sector of the south east were investigated. Findings have shown that the average non productive and active times of the trades respectively are at an average ranges of 25% - 37.20% and 62.5% - 75% for the masonry trade; and average of 18.80% - 31.20% and 68.80% - 81.20% for carpentry trade respectively. The study also proves that standard times and standard outputs of the trades respectively stand at 1.37 hr/m2 and 0.75 m2/hr for the masonry trade; and 0.85 hr/m2 and 1.19 m2/hr for carpentry trade respectively. Consequently, the labour rates of the masonry and carpentry trades are estimated at 6 m2 and 9.52 m2 respectively. In an effort to compare the labour rate of the skilled workers in the EPP with those in some major private construction firms and civil service, it was discovered that labour rates of workers in EPP are lesser than the others; likewise the wage rates respectively. Although the labour rate of the skilled labour in EPP are lesser than those in the other places of work, the wage rates of the work trades in EPP are far lesser than the wage rates in the other areas of employment; hence the ratio of the wage rate to labor rates in EPP are significantly lesser than the ratios in the other areas especially, the construction firms in the study area. This study recommends therefore an establishment of a data base framework in the power sector for improved remuneration of the skilled labour that incorporates need based and certified training programme, towards effective delivery of EPP in the south east and Nigeria in general.
Development of Models for Rainfall Intensity- duration-frequency for Akure, South-west, Nigeria
Authors: David A. O. , Nwaogazie Ify L. , Agunwamba J. C.
Published: August 2019

The rainfall Intensity-Duration-Frequency (IDF) relationship is widely used for adequate estimation of rainfall intensity over a particular catchment. A 25 year daily rainfall data were collected from Nigerian Meteorological Agency (NIMET) Abuja for Akure station. Twenty five year annual maximum rainfall amounts with durations of 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240, 300 and 420 minutes were extracted and subjected to frequency analysis using the excel solver software wizard. A total of six (6) return period specific and one (1) general IDF models were developed for return periods of 2, 5, 10, 25, 50 and 100 years using Gumbel Extreme Value Type-1 and Log Pearson Type -3 distributions. Anderson Darling goodness of fit test was used to ascertain the best fit probability distribution. The R2 values range from 0.982 to 0.985 for GEVT -1 and 0.978 to 0.989 for Log Pearson type -3 while the Mean Squared Error from 33.56 to 156.50 for GEVT -1 and 43.01 to 150.63 Log Pearson Type III distributions respectively. The probability distribution models are recommended for the prediction of rainfall intensities for Akure metropolis.
A Educação Socialista na China durante a Grande Revolução Cultural Proletária (1966-1976)
Authors: Souza Marilsa Miranda de
Published: August 2019

O artigo apresenta alguns apontamentos sobre a educação na China Socialista, especialmente no curso da Grande Revolução Cultural Proletária (GRCP) de 1966 a 1976. A primeira fase da Revolução Chinesa se desenvolveu na ordem econômica e política e posteriormente passou para o campo ideológico com a GRCP que desencadeou a chamada Revolução no Ensino, fundada nos princípios do Marxismo-Leninismo e do Pensamento Mao Tsetung. A Revolução no Ensino teve como pilar fundamental a vinculação do ensino com o trabalho produtivo e contou com ampla participação das massas operárias e camponesas que tomaram em suas mãos a tarefa de defender o socialismo contra o processo de restauração capitalista na China.
Escola Única do Trabalho Pós-Revolução Russa de 1917 e o Trabalho como Princípio Educativo
Authors: Leite Valter De Jesus , Porto Borges Liliam Farias
Published: August 2019

Nos marcos dos cem anos da revolução Russa de 1917, objetivamos, neste artigo, indicar elementos que integraram a experiência da Escola Única do Trabalho pós-revolução Russa (1917-1931). Para tal, recorremos a um estudo bibliográfico, que tem por base, essencialmente os escritos de Pistrak, Lunatcharski, Krupskaia, Shulgin, Lenin, Freitas, Saviani e os Programas Oficiais da Educação na República dos Soviets. Destacamos, a partir desses estudos, que construir os embriões da sociedade socialista é educar e agir nas contradições das condições e das determinações da sociedade capitalista na atualidade com vistas à transformação social.
A política educacional nas primeiras décadas do século XXI: formas de expansão dos interesses das classes dominantes na história da educação nacional
Authors: Felix Rosar Maria De Fatima
Published: August 2019

Resumo: Destaca-se neste artigo a necessidade de se compreender a política educacional como uma das formas de expressão da desigualdade intrínseca à estrutura da sociedade de classes. A análise e interpretação percuciente da política educacional brasileira, nesse contexto, tem sido a tônica da contribuição dos autores dos artigos da Germinal nos quais são destacadas as particularidades desse processo histórico, como se pretende ressaltar ao revisitar parte da produção contida nos diversos números editados, desde o ano de 2009.

 
Educação Física na Germinal: 10 anos de contribuições em defesa do Marxismo
Authors: Taffarel Celi Nelza Zulke , Hack Cássia , Morschbacher Márcia
Published: August 2019

Este texto apresenta balanço das contribuições da área da Educação Física em Germinal: Marxismo e Educação em Debate. A análise considerou os desafios do tempo histórico, reconhecendo limites, contradições frente às contingências. Nas conclusões são apresentadas possibilidades superadoras considerando a luta de classes, no contexto brasileiro de avanços das forças destrutivas na economia, da extrema-direita neofascista na política, com a consolidação do Estado militarizado e de exceção e, na educação e ciência com a negação da verdade, o esvaziamento dos currículos de conteúdos nucleares, a destruição da razão humana e os ataques contra o marxismo.
Germinal: Marxismo e Educação em Debate: 10 anos!!
Authors: Peixoto Elza Margarida de Mendonça
Published: August 2019

Os planos do Conselho Editorial para as comemorações dos 10 anos de Germinal eram ambiciosos!! Avaliávamos que esta primeira década deste instrumento de luta não poderia passar sem um adequado balanço das condições em que vimos produzindo Germinal. Pretendíamos realizar um documentário retratando a história da Revista, com depoimentos de editores, autores e leitores que a vêm construindo. A falta de recursos e as demandas da conjuntura impossibilitaram a conclusão deste intento que fica aguardando melhor oportunidade. O que fazer? Decidimos direcionar o balanço à seção Entrevista, avaliando que a alternativa mais correta era trazer as posições dos membros do Conselho Editorial da Germinal sobre estes dez anos. Convocamos a todos os membros do Conselho para a resposta ao roteiro elaborado sob encomenda pelos professores Lucelma Silva Braga (UFMA), Marcelo Pereira de Almeida Ferreira (UFPA), Hugo Rodrigues e Leandro Sartori Gonçalves (UNICAMP), Rogério Massarotto (UEM) e Itamar Silva de Sousa (UNEB). Responderam ao roteiro e à proposta de balanço por parte do Conselho, Elza Margarida de Mendonça Peixoto, Maria de Fátima Félix Rosar, Paulino Orso, Celi Nelza Zulke Taffarel e José Claudinei Lombardi. O resultado é um interessante balanço das condições nas quais Germinal surge e dos desafios para a sua produção e permanência.
Increased mistranslation protects E. coli from protein misfolding stress due to activation of a RpoS‐dependent heat shock response
Authors: Evans Christopher R. , Fan Yongqiang , Ling Jiqiang
Published: August 2019

The misincorporation of an incorrect amino acid into a polypeptide during protein synthesis is considered a detrimental phenomenon. A mistranslated protein is often misfolded and degraded or nonfunctional and results in an increased cost to quality control machinery. Despite these costs, errors during protein synthesis are common in bacteria. Here, we report that mistranslation in Escherichia coli increase the protein level of the heat shock sigma factor RpoH and protect cells against heat stress. Surprisingly, this increase in RpoH due to mistranslation is dependent on the presence of the general stress response sigma factor RpoS. This report provides evidence for a protective function of mistranslation and suggests a novel regulatory role of RpoS in the heat shock response.
Association between substance use disorders and self‐ and other‐directed aggression: An integrated model approach
Authors: Ghossoub Elias , Adib Salim M. , Maalouf Fadi T. , Fuleihan Ghada E.‐H. , Tamim Hani , Nahas Ziad
Published: August 2019

Our study's objective is to determine whether substance use disorders’ association with aggression differs according to the type of substance and/or the form of aggression, within the same population. We used data from the National Survey on Drug Use and Health across 2008–2014, with a pooled sample of 270,227 adult respondents. We used regression models to estimate the odds ratios for those having alcohol and/or drug use disorder(s) perpetrating (a) each form of aggression compared with no aggression and (b) other‐directed compared with self‐directed aggression. Alcohol use disorder alone and drug use disorder(s) alone were both associated with significantly increased odds of committing self‐directed, other‐directed, and combined aggression. Individuals with drug use disorder(s) alone were more likely to commit other‐directed than self‐directed aggression (adjusted odds ratio = 1.46, 95% CI = 1.04–2.05). Individuals with alcohol use disorder alone were not likely to commit one over the other (adjusted odds ratio = 1.20, 95% CI = 0.90–1.61). In conclusion, the integrated model of aggression based on the stress–diathesis model is a relevant framework to study risk factors for aggression. Further research is needed to identify longitudinal predictors of directionality of aggression.
DPA's drug prevention curriculum teaches responsible use, no‐use at the same time
Authors: Knopf Alison
Published: August 2019

Although it's not officially released yet, the prevention curriculum for schools from the Drug Policy Alliance (DPA) is not getting favorable reviews from prevention experts. ADAW shared a July 23 press release about the curriculum, called “Safety First: Real Drug Education for Teens,” with these experts, and then received a draft of the curriculum itself.
Switchable Friction across Insulator–Metal Transition in VO2
Authors: Singh Davinder , Mittal Prashant , Gosvami Nitya Nand , Balakrishnan Viswanath
Published: August 2019

Significant friction turnover across the insulator to metal phase transition of VO2 microcrystals as measured by friction force microscopy (FFM) and nanoscratch experiments is reported. Insulator to metal transition in chemical vapor deposition‐grown VO2 platelet is confirmed by in situ Raman investigations and electrical resistance measurements that show more than four orders of magnitude change in electrical resistance across transition temperature. The coefficient of friction (COF) for the high‐temperature metallic phase, that is about two times higher than that of room‐temperature insulating phase, is demonstrated. To avoid temperature effects on friction, the friction of coexisting insulating and metallic phases at a constant temperature of ≈69 °C is measured. Additionally, the results also show that this twofold increase in COF is fully reversible when the phase transition is triggered by a heating–cooling cycle and can potentially be used as tuneable friction‐based gripping systems.
Fabrication of Graphene‐Covered Micro‐Tubes for Process Intensification
Authors: Chong Jeng Y. , Wang Bo , Sherrell Peter C. , Pesci Federico M. , Mattevi Cecilia , Li Kang
Published: August 2019

Graphene is known for its high surface‐area‐to‐mass ratio. However, for using graphene in engineering processes such as catalytic reactors or heat exchangers, a high surface‐area‐to‐volume ratio is essential. Currently, graphene is only prepared in sheet form, which limits its surface‐area‐to‐volume ratio to around 200 m2 m−3. Herein, a technique based on chemical vapor deposition (CVD) to realize graphene on a micro‐tubular substrate to not only substantially increase its surface‐area‐to‐volume ratio to a value over 2000 m2 m−3 but also to eliminate the maldistribution of flows commonly unavoidable in flat‐sheet configurations is proposed and demonstrated. This approach uses a dual‐layer micro‐tubular substrate fabricated by a phase‐inversion technique. In the substrate, a thin copper outer layer is used to enable the CVD growth of graphene, and an inner Cu–Fe layer is adopted to provide a strong mechanical support. This approach is feasible to produce graphene with a very high surface‐area‐to‐volume ratio for possible applications in catalytic reactors or heat exchangers, although problems such as inter‐diffusion between the two metal layers and defects in graphene need to be addressed. To the best of our knowledge, this study is the first attempt to prepare graphene with high surface‐area‐to‐volume ratios by a CVD route.
Two‐Sidedness of Surface Reaction Mediation
Authors: Chen Haoran , Zhu Hao , Huang Zhichao , Rong Wenhui , Wu Kai
Published: August 2019

A heterogeneous catalytic process involves many surface elementary steps that affect the overall catalytic performance in one way or another. In general, a high‐performance heterogeneous catalyst should meet the main criteria: excellent catalytic activity and high selectivity toward target products. Using surface science techniques, the two‐sidedness of the surface reaction mediations can be explored, from the perspectives of the surface and the molecule manipulations. The surface manipulation refers to a reaction that is mediated by composition and structure of the substrate as well as surface species, while the molecular manipulation relates to a reaction that is mediated by the reacting molecule via the precursor selection, environmental control, or external excitation. The best catalytic system should consist of the most efficient catalyst and the best suitable reacting molecule, in addition to its economic benefit and environmental amity. Recent research progress in surface reaction mediation is outlined, and its two‐sidedness is governed by the Arrhenius equation. This should shed new light on the connection between basic theory and surface reaction mediation strategies. To conclude, challenges and possible opportunities are elaborated for efficient surface reaction mediations.
Ultrastretchable and Wireless Bioelectronics Based on All‐Hydrogel Microfluidics
Authors: Liu Yaming , Yang Tiyun , Zhang Yuyan , Qu Gang , Wei Shanshan , Liu Zhou , Kong Tiantian
Published: August 2019

Hydrogel bioelectronics that can interface biological tissues and flexible electronics is at the core of the growing field of healthcare monitoring, smart drug systems, and wearable and implantable devices. Here, a simple strategy is demonstrated to prototype all‐hydrogel bioelectronics with embedded arbitrary conductive networks using tough hydrogels and liquid metal. Due to their excellent stretchability, the resultant all‐hydrogel bioelectronics exhibits stable electrochemical properties at large tensile stretch and various modes of deformation. The potential of fabricated all‐hydrogel bioelectronics is demonstrated as wearable strain sensors, cardiac patches, and near‐field communication (NFC) devices for monitoring various physiological conditions wirelessly. The presented simple platform paves the way of implantable hydrogel electronics for Internet‐of‐Things and tissue–machine interfacing applications.
Formal [5+3] Cycloaddition of Vinylethylene Carbonates with Isatin‐Based α‐(Trifluoromethyl)imines for Diastereoselective Synthesis of Medium‐Heterocycle‐Fused Spirooxindoles
Authors: Zhao Hong‐Wu , Wang Li‐Ru , Guo Jia‐Ming , Ding Wan‐Qiu , Song Xiu‐Qing , Wu Hui‐Hui , Tang Zhe , Fan Xiao‐Zu , Bi Xiao‐Fan
Published: August 2019

In the presence of Pd(PPh3)4 (2.5 mol%), PPh3 (10 mol%) and pyridine (2.0 equiv.), the formal [5+3] cycloaddition of vinylethylene carbonates with isatin‐based α‐(trifluoromethyl)imines proceeded readily, and delivered trans‐configured novelmedium‐heterocycle‐fused spirooxindoles in 75–97% chemical yields with excellent diastereoselectivities. The relative stereochemical configuration of the title products was identified by X‐ray diffraction analysis.

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Enhancing thermostability by modifying flexible surface loops in an evolved high‐redox potential laccase
Authors: Vicente Ana I. , Viña‐Gonzalez Javier , Mateljak Ivan , Monza Emanuele , Lucas Fatima , Guallar Victor , Alcalde Miguel
Published: August 2019

High‐redox potential laccases (HRPLs) from white‐rot fungi are versatile biocatalysts whose practical use is highly dependent on their thermostability. In this work, an evolved HRPL variant was subjected to structure‐guided evolution to improve its thermostability. We first selected several surface flexible loops in the laccase structure by inspecting them through molecular dynamics and an analysis of B‐factors. The resulting segments were grouped into three MORPHING (Mutagenic Organized Recombination Process by Homologous In vivo Grouping) blocks, which were constructed in Saccharomyces cerevisiae and explored at high temperatures. This evolution process gave rise to a double mutant that showed a half‐life at 70°C enhanced by 31 min with an optimum temperature for activity of 75°C and similar kinetic parameters. The Ser264Lys and Ser356Asn mutations modified the contacts established between these residues and those that surround them, altering the surface loops and thereby the enzyme properties.
A novel eye‐tracking paradigm for indexing social avoidance‐related behavior in fragile X syndrome
Authors: Klusek Jessica , Moser Carly , Schmidt Joseph , Abbeduto Leonard , Roberts Jane E.
Published: August 2019

Fragile X syndrome (FXS) is characterized by hallmark features of gaze avoidance, reduced social approach, and social anxiety. The development of therapeutics to manage these symptoms has been hindered, in part, by the lack of sensitive outcome measures. This study investigated the utility of a novel eye‐tracking paradigm for indexing social avoidance‐related phenotypes. Adolescent/young adult‐aged males with FXS (n = 24) and typical development (n = 23) participated in the study. Participants viewed faces displaying direct or averted gaze and the first fixation duration on the eyes was recorded as an index of initial stimulus registration. Fixation durations did not differ across the direction of gaze conditions in either group, although the control group showed longer initial fixations on the eyes relative to the FXS group. Shorter initial fixation on averted gaze in males with FXS was a robust predictor of the severity of their social avoidance behavior exhibited during a social greeting context, whereas parent‐reported social avoidance symptoms were not related to performance in the semi‐naturalistic context. This eye‐tracking paradigm may represent a promising outcome measure for FXS clinical trials because it provides a quantitative index that closely maps onto core social avoidance phenotypes of FXS, can be completed in less than 20 min, and is suitable for use with individuals with low IQ.
Two‐Dimensional Conjugated Aromatic Networks as High‐Site‐Density and Single‐Atom Electrocatalysts for the Oxygen Reduction Reaction
Authors: Yang Shaoxuan , Yu Yihuan , Dou Meiling , Zhang Zhengping , Dai Liming , Wang Feng
Published: August 2019

Two‐dimensional conjugated aromatic networks (CAN) with ultra‐thin conjugated layers (ca. 3.5 nm) and high single‐metal‐atom‐site density (mass content of 10.7 wt %, and 0.73 metal atoms per nm2) are prepared via a facile pyrolysis‐free route involving a one‐step ball milling of the solid‐phase‐synthesized polyphthalocyanine. These materials display outstanding oxygen reduction reaction (ORR) mass activity of 47 mA mgcat.−1 represents 1.3‐ and 6.4‐fold enhancements compared to Pt and Pt/C in benchmark Pt/C, respectively. Moreover, the primary Zn‐air batteries constructed with CAN as an air electrode demonstrate a mass/volume power density of 880 W gcat.−1/615 W cmcat.−3 and stable long‐term operation for 100 h. This strategy offers a new way to design high‐performance electrocatalysts with atomic precision for use in other energy‐storage and conversion applications.
Unveiling the Hidden, Dark, and Short Life of a Vibronic State in a Boron Difluoride Formazanate Dye
Authors: Melenbacher Adyn , Dhindsa Jasveer S. , Gilroy Joe B. , Stillman Martin J.
Published: August 2019

Boron difluoride (BF2) formazanate dyes are contenders for molecular species that exhibit a large Stokes shift and bright red emission. Excitation of 3‐cyanoformazanate complexes with 10 μs wide pulses of specific wavelengths resulted in strong luminescence at 663 nm at both room temperature in solution and at 77 K in a frozen solution. Analysis of the short‐lived excitation spectrum from this luminescence shows that it arises from a vibronic manifold of a higher‐lying excited state. This dark state relaxes to the emitting state over 10 μs. TD‐DFT calculations of the two lowest‐energy excited states show that the relaxed geometries are planar for S1 but highly distorted in S2. The specific time‐ and wavelength‐dependence of the excitation profile provides a unique optical encryption capability through the comparison of emission intensities between adjacent vibronic bands only accessible in the 0–12 μs time domain.
Three's a crowd: Stella's pregnancy and the arrival of an “other” in A Streetcar Named Desire
Authors: Jacobs Daniel
Published: August 2019

This paper explores the difficulties that may arise for some men when their wives become pregnant. The advent of a child may threaten the intense marital dyadic relationship on which a man may depend. The author explores how this particular threat to a husband's sense of security is manifest dramatically in Tennessee Williams's A Streetcar Named Desire. In this reading of the play, Stella's pregnancy and Stanley's feelings about it lie at the heart of the drama.
Improving Pulverized Coal and Biomass Co‐Combustion in a Cement Rotary Kiln by Computational Fluid Dynamics
Authors: Mikulčić Hrvoje , Cerinski Damijan , Baleta Jakov , Wang Xuebin
Published: August 2019

The cement industry is one of the largest pollutant emitters. One way to cope with high pollutant emissions is to co‐combust biomass with pulverized coal. A mathematical model was developed, which is detailed enough to consider the complex physical and chemical behavior of the co‐combustion process but simple enough to perform simulations with a real geometry of cement rotary kiln within reasonable time. Numerical simulation with a 20‐% share of pulverized biomass of total fuel heating value was performed. An industrial rotary kiln geometry was simulated; temperature and velocity fields along with mass fractions of released volatiles and combustion products were analyzed. The model allows better insights in the co‐firing process with the main goal to reduce CO2 emissions by optimizing the combustion process inside the rotary kiln.
High‐Voltage Performance of Ni‐Rich NCA Cathodes: Linking Operating Voltage with Cathode Degradation
Authors: David Lamuel , Mohanty Debasish , Geng Linxiao , Ruther Rose E. , Sefat Athena S. , Cakmak Ercan , Veith Gabriel M. , Meyer Harry M. , Wang Hsin , Wood David L.
Published: August 2019

High‐voltage Ni‐rich cathodes have been studied as a possible way to achieve high energy density in Li‐ion batteries. However, capacity fade due to structural changes at high voltages has limited their applications. This study identifies 4.5 V (vs. graphite) as the optimum upper cutoff voltage (UCV) for a Ni‐rich NCA cathode [LiNi0.8Co0.15Al0.05O2]. At this UCV, NCA delivers a 12 % increase in reversible capacity (when discharged to 2.5 V) and retains 92 % of its initial capacity after 100 cycles at 1C/‐1C cycling when compared to 4.2 V as UCV. By increasing UCV to 4.7 V, the discharge capacity can be raised to >200 mAh/g. However, the rate of capacity fade is greater when compared to 4.5 V as UCV. This increased rate of capacity fade, at higher UCV, is related to irreversible lattice contractions that leads to structural rearrangement at charged states during high‐voltage cycling. Our results show a change in transition metal oxidation states and an onset of structural ordering occurs when the UCV is 4.7 V.
Colorimetric and Fluorimetric DNA Detection with a Hydroxystyryl–Quinolizinium Photoacid and Its Application for Cell Imaging
Authors: Das Avijit Kumar , Druzhinin Sergey I. , Ihmels Heiko , Müller Mareike , Schönherr Holger
Published: August 2019

The combination of styryl dye properties with the acidity and strong photoacidity of the 2,2′‐[(1′′‐hydroxy‐4′′‐methyl‐(E)‐2′′,6′′‐phenylene)]‐bisquinolizinium enables the detection of DNA by distinct absorption and emission color changes and the fluorimetric detection of DNA in cells with epifluorescence and confocal fluorescence microscopy.
Innovative Linker Strategies for Tumor‐Targeted Drug Conjugates
Authors: Dal Corso Alberto , Pignataro Luca , Belvisi Laura , Gennari Cesare
Published: August 2019

The covalent conjugation of potent cytotoxic agents to either macromolecular carriers or small molecules represents a well‐known approach to increase the therapeutic index of these drugs, thus improving treatment efficacy and minimizing side effects. In general, cytotoxic activity is displayed only upon cleavage of a specific chemical bond (linker) that connects the drug to the carrier. The perfect balance between the linker stability and its selective cleavage represents the key for success in these therapeutic approaches and the chemical toolbox to reach this goal is continuously expanding. In this Review article, we highlight recent advances on the different modalities to promote the selective release of cytotoxic agents, either by exploiting specific hallmarks of the tumor microenvironment (e.g. pH, enzyme expression) or by the application of external triggers (e.g. light and bioorthogonal reactions).
Neural attention model with keyword memory for abstractive document summarization
Authors: Choi YunSeok , Kim Dahae , Lee Jee‐Hyong
Published: August 2019

Abstractive summarization is the task of creating summaries by generating a set of novel sentences based on the information extracted from the original document, while most of summarization researches are based on extractive or compressive approaches. These approaches extract phrases from the original document and concatenate them by post‐processing and cannot truly encapsulate the contents of summaries, because they only reuse the phrases in the given document. Moreover, there are limits for paraphrasing and re‐organizing of the original contents with the current Natural Language Processing (NLP) techniques. With these reasons, we propose a novel abstractive summarization method. The main goal of our paper is to generate a long sequence of words with coherent sentences by reflecting the key concepts of the original document and the contents of summaries. To achieve this goal, we propose an attention mechanism that uses Document Content Memory for learning the language model effectively. To evaluate its effectiveness, the proposed methods are compared with other language models and an extractive summarization method. We demonstrate that our proposed methods improve summarization results in ROUGE score using ACL dataset. The experimental results show that our proposed methods using keyword memory are effective to generate long sequence summary.
Varieties of capitalism, corporate governance mechanisms, and stakeholder engagement: An overview of coordinated and liberal market economies
Authors: Pucheta‐Martínez María Consuelo , Gallego‐Álvarez Isabel , Bel‐Oms Inmaculada
Published: August 2019

This paper examines those aspects of national institutions that affect corporate governance mechanisms at international level. The study uses the “varieties of capitalism” approach, which is concerned with the way companies interact strategically to solve the coordination problems arising from their activities. This research is based on a sample of countries operating in coordinated market economies and liberal market economies. The data were collected from the Thomson Reuters database. The findings suggest that the institutional context is associated with several corporate governance mechanisms. Specifically, our results find that the proportion of female directors on boards and the presence of corporate governance committees are higher in firms operating in liberal market economies than in those domiciled in coordinated market economies. Regarding the disclosure of corporate social responsibility information, the evidence shows that it is not affected by the varieties of capitalism measured, whereas board‐specific skills are higher in the latter than in the former. This paper offers empirical evidence at international level for the varieties of capitalism that contribute to better corporate governance structures. With regard to managerial implications, our findings show that belonging (or not) to a specific variety of capitalism impacts various mechanisms of corporate governance.
Biomimetic Reductive Cleavage of Keto Aryl Ether Bonds by Small‐Molecule Thiols
Authors: Klinger Grace E. , Zhou Yuting , Hao Pengchao , Robbins Jacob , Aquilina Jake M. , Jackson James E. , Hegg Eric L.
Published: August 2019

The nucleophilic and reductive properties of thiolates and thiols make them ideal candidates as redox mediators via the thiol/disulfide couple. One mechanism for biological lignin depolymerization entails reduction of keto aryl ether bonds by an SN2 mechanism with the thiol redox mediator glutathione. In this study, mimicking this chemistry in a simple protein‐ and metal‐free process, several small organic thiols are surveyed for their ability to cleave aryl keto ethers that model the β‐O‐4 linkages found in partially oxidized lignin. In polar aprotic solvents, β‐mercaptoethanol and dithiothreitol yielded up to 100 % formation of phenol and acetophenone products from 2‐phenoxyacetophenone, but not from its reduced alcohol congener. The effects of reaction conditions and of substituents on the aryl rings and the keto ether linkage are assessed. These results, together with activation barriers computed by quantum chemical simulations and direct observation of the expected intermediate thioether, point to an SN2 mechanism. This study confirms that small organic thiols can reductively break down lignin‐relevant keto aryl ether linkages.
An Organic Molecular Photocatalyst Releasing Oxygen from Water
Authors: Li Qinghe , Liu Feng , Lin Feng , Lin Wei , Wang Xinchen
Published: August 2019

Artificial photosynthesis employing solar energy is one of the best means of reaching a sustainable energy cycle, in which water is oxidized to oxygen and supplies electrons for fuel generation. The development of suitable oxygen evolution materials driven by sunlight is hence the most challenging research topic in the field of photocatalysis. Herein, photocatalytic O2 production from water at a rate of 22.6 μmol h−1 was performed by using a pyrene‐based organic molecule constructed through the Ullmann coupling reaction. Its significantly improved light‐harvesting ability and notably accelerated separation and transfer of photogenerated charges enhanced the O2 evolution efficiency. This study highlights the structural design of organic molecules applied to photocatalytic water splitting.