bluuebunny/crossref_metadata_2025 huggingface dataset:
Educação ambiental: instrumento de mudança de percepção ambiental de catadores de materiais recicláveis organizados em associação
Authors: Maia Hérika Juliana Linhares , Cavalcante Lívia Poliana Santana , Oliveira Alinne Gurjão de , Silva Monica Maria Pereira da
Published: April 2021

Este trabalho teve como objetivo avaliar a mudança de percepção ambiental dos catadores de materiais recicláveis associados à ARENSA (Associação dos Catadores de Materiais Recicláveis de Nossa Senhora Aparecida) Campina Grande–PB. O processo de formação dos catadores de materiais recicláveis acontece desde 2008. Contudo, a pesquisa exploratória, realizada de janeiro a fevereiro de 2012, foi construída a partir da análise comparativa de dados colhidos em 2010 e 2012. A mudança de percepção proporcionou aos catadores de materiais recicláveis a sua inserção no meio social permitindo o entendimento do valor da profissão exercida hodiernamente. A satisfação profissional demonstra que o grupo é detentor de grande autoestima, abstraindo-se da ideia de que a catação de resíduos é uma atividade inferior e vergonhosa, contrariando o cenário brasileiro. Apesar dos avanços originados do processo de educação ambiental desde 2008, há desafios a serem superados, dentre os quais: renda mensal digna e condições de infraestrutura.
Sintomas de ansiedade, depressão e ansiedade cardíaca pré-operatórios segundo o tipo de cirurgia cardíaca
Authors: Martins Letícia Mansano , Kazitani Bruna Sonego , Bolela Fabiana , Maier Suéllen Rodrigues de Oliveira , Dessotte Carina Aparecida Marosti
Published: April 2021

Introduction: observing the difference in profile of patients undergoing coronary artery bypass graft surgery from those undergoing surgical correction of valvular heart disease, it is considered important to assess the emotional state according to the surgery to be performed. Objective: to compare the symptoms of anxiety, depression, and cardiac anxiety of patients in the preoperative period, according to the type of cardiac surgery to be performed: myocardial revascularization or surgery to correct valvular heart diseases. Method: observational, analytical, cross-sectional study carried out in the surgery wards of a university hospital in the countryside of São Paulo. A consecutive and non-probabilistic sample was made up of older patients who came home for hospitalization and whose appointment for the surgery was elective. To evaluate the symptoms of anxiety and depression, the Hospital Anxiety and Depression Scale instrument was used; for the assessment of cardiac anxiety, the “Heart Anxiety Questionnaire” was used. To compare the measures of symptoms, according to the type of surgery, the Mann-Whitney test was performed for independent samples, with a significance level of 5%. Results: the groups were homogeneous among themselves, in terms of sociodemographic characterization, except for age. Patients in the preoperative period for correction of valvular heart disease had a higher score for the symptoms of cardiac anxiety when compared with patients in the preoperative period of myocardial revascularization, and the difference found was statistically significant (p=0.020). Conclusion: patients in the preoperative period for correction of valvular heart disease presented more symptoms of cardiac anxiety when compared with patients in the preoperative period of myocardial revascularization.
REFLEXÕES ACERCA DA "INFODEMIA" RELACIONADA À COVID-19
Authors: Alencastro Aynoan de Sousa Amaro , Melo Emanuella Silva Joventino
Published: April 2021

RESUMO Este estudo tem o objetivo de refletir sobre os impactos negativos que a disseminação desenfreada de notícias sobre a COVID-19 pode trazer para a saúde e para a sociedade. Desse modo, destaca-se a necessidade de ações e intervenções que previnam ou minimizem esses impactos e que sensibilizem a população quanto ao correto manejo das informações, de forma a diminuir as repercussões prejudiciais da infodemia acerca dessa nova afecção. Trata-se de uma análise reflexiva sobre as consequências que a "infodemia" pode causar à saúde e à sociedade, devido à divulgação desenfreada de notícias relacionadas à COVID-19. Nesse contexto, ressalta-se que foi possível perceber que a "infodemia", ou seja, o excesso de informações, precisas ou não, sobre a COVID-19 traz inúmeros impactos maléficos para a saúde mental da população e dos profissionais de saúde, bem como para os serviços de saúde e para a sociedade. Esse fato demonstra a necessidade de realização de pesquisas e de ações educativas que proporcionem a diminuição dos efeitos nocivos ocasionados por esse fenômeno.
VIOLÊNCIA POR PARCEIRO ÍNTIMO EM REGIÃO DE TRÍPLICE FRONTEIRA
Authors: Silva Gabriela Kauana , Rocha-Brischiliari Sheila Cristina , Miura Aline Suelen , Martins Wesley , Becker Mariane , Santos Marieta Fernandes
Published: April 2021

RESUMO Objetivo: analisar a prevalência da violência por parceiro íntimo contra mulheres e seus fatores associados. Método: estudo descritivo e transversal, quantitativo, com mulheres usuárias das unidades básicas de saúde de Foz do Iguaçu, análise realizada por meio de testes qui-quadrado de Mantel-Haenszel nos fatores de risco e proteção baseados na OddsRatio (OR). Resultados: foram realizadas 565 entrevistas com mulheres usuárias das unidades de saúde da família na atenção básica do município. A maior prevalência foi de violência psicológica (51,3%), seguida da física (36,5%) e sexual (22,8%). Com base nos dados, os maiores fatores de risco para a violência foram: idade; alto nível de escolaridade; estado civil divorciado; uso de drogas e antecedentes familiares de violência na família do parceiro; e temperamento do parceiro. Conclusão: conhecer os fatores associados ao agravo ajuda em sua identificação e melhor manejo na Estratégia Saúde da Família (ESF), bem como contribui para que o município estabeleça ações de educação continuada para profissionais do ESF, a fim de sensibilizar para uma abordagem da violência no cotidiano desses serviços.
VALIDAÇÃO DE CONTEÚDO DOS ENUNCIADOS DO SUBCONJUNTO CIPE® PARA PESSOAS COM ÚLCERAS VASCULOGÊNICAS
Authors: Pires Sandra Maria Bastos , Rodrigues Ana Luzia , Bastos Claudia Biancato , Cubas Marcia Regina
Published: April 2021

RESUMO Objetivo: validar o conteúdo dos enunciados do subconjunto terminológico da Classificação Internacional das Práticas de Enfermagem (CIPE®) para pessoas com úlceras vasculogênicas, baseado na teoria da adaptação de Roy. Método: trata-se de recorte de estudo metodológico, referente à fase de validação da terceira etapa do método brasileiro para desenvolvimento de subconjunto terminológico da CIPE®. Foram analisados, por seis especialistas selecionados, 59 diagnósticos e 103 resultados, distribuídos nos modos adaptativos de Roy, e 424 intervenções de Enfermagem, organizadas em grupos relacionados ao diagnóstico. Foi calculado o percentual de concordância e foram validados os enunciados com percentual igual ou superior a 80%. Resultados: dos diagnósticos, 10 obtiveram 100% de concordância, dos quais oito apresentaram seus resultados e intervenções com 100% de concordância. Dos 46 diagnósticos com 86% de concordância, oito tiveram seus resultados e intervenções com 100% de concordância. Não foram validados os diagnósticos com percentual de concordância de 50%, a saber: risco de função do sistema gastrointestinal, prejudicado; sono, prejudicado; e hipocalcemia. Conclusão: foram validados 56 diagnósticos, 99 resultados e 411 intervenções de Enfermagem. O modo fisiológico foi o mais representado, devido à característica da base empírica utilizada. Será necessário ampliar a lista com enunciados referentes à interdependência e função de papel.
Shared Features of Successful Interorganizational Collaboration to Promote Local Talent Development Environments in Denmark
Authors: Mathorne Ole , Stambulova Natalia , Book Rob , Storm Louise Kamuk , Henriksen Kristoffer
Published: April 2021

The aim of this study was to explore 11 case examples of successful talent development collaborations between sport federations, municipalities, and local clubs in Denmark in order to identify potential shared features of successful collaborations. We hypothesized that each case example would be unique, but that they would also share features that could be organized to provide practitioners with a model to guide the improvement of their practice. Grounded in the holistic ecological approach, the study was designed as a multiple case study to facilitate a cross-case analysis. Three Danish sport federations (handball, ice hockey, and swimming), nine municipalities, and eleven local clubs participated in the study, and the data was generated from 23 semi-structured interviews with stakeholders. Analysis led to the construction of six shared features of successful interorganizational collaboration organized into: (1) a list of features (SFIC-TD) with positive and opposite pole descriptors and three categories: collaborative philosophy, collaborative decisions, and collaborative actions, and (2) an applied framework termed the pyramid model for optimization of interorganizational collaboration in talent development (PIC-TD) which illustrates how the abovementioned categories lead to collaborative outcomes. Developing a shared philosophy of talent development was found to be a foundational starting point for successful collaboration between relevant organizations on the micro- and macro-level to improve the local athletic talent development environment.
La recherche qualitative : une analyse du vécu humain. Clarification conceptuelle à partir de nos recherches avec des personnes marginalisées
Authors: Guillemette François , Luckerhoff Jason , Plouffe Marie-Josée , Fall Ousmane Thiendella
Published: April 2021

Au cours de la première moitié du XXe siècle, dans un contexte d’hégémonie de la recherche quantitative et hypothético-déductive, la recherche qualitative a été présentée comme une façon d’analyser en profondeur un objet de recherche. Il n’y a pas de consensus sur la définition de la recherche qualitative et la diversité empreinte d’ambiguïtés se manifeste aussi dans les pratiques méthodologiques qui sont présentées sous l’appellation de la recherche qualitative. Les auteurs du présent article, en partant de leurs divers projets de recherche avec des personnes marginalisées, proposent ici une définition de la recherche qualitative en tant qu’étude du vécu humain. Pour eux, la recherche qualitative étudie le vécu humain à partir de la conscience que les vivants en ont. Pour réaliser cette étude, les chercheurs doivent recueillir des données sur cette conscience et ils doivent les analyser méthodiquement pour en proposer une compréhension pertinente. Ainsi, la recherche qualitative répond aux exigences essentielles de toute démarche scientifique, c’est-à-dire, d’une part, l’exigence de collecter des données qui proviennent du phénomène étudié (et qui ne sont pas inventées) et, d’autre part, l’exigence d’en faire une analyse sérieuse pour débusquer les idées reçues. Il s’agit donc d’étudier les phénomènes humains dans une grande ouverture à la découverte de ce qui n’est pas encore connu. Cette ouverture se traduit notamment dans une réserve ou une mise à distance des théories explicatives existantes.
Cadrage de l’épidémie de Zika de 2016 par la presse canadienne francophone
Authors: Khouiyi Al Hassania
Published: April 2021

Lorsqu’il s’agit de renseignements dépassant le quotidien des citoyens, ces derniers se tournent vers les médias comme principaux pourvoyeurs d’information. La relation de dépendance entre citoyens et médias revêt une délicate importance lorsqu’il s’agit de situations d’exception comme les épidémies. Nous nous intéressons à la manière dont la presse canadienne francophone a couvert et cadré l’épidémie de Zika de 2016 en nous inspirant des théories du cadrage. Dans cette étude exploratoire et qualitative, nous avons analysé 45 articles publiés entre octobre 2015 et mai 2017. Notre analyse thématique a permis d’identifier quatre cadres : le cadre informationnel, le cadre émotionnel, le cadre institutionnel et le cadre moralisateur. L’analyse a révélé que le cadrage de l’épidémie de Zika a été un cadrage en mouvance qui est passé du caractère thématique au caractère épisodique au fur et à mesure que l’épidémie a évolué.
Le livre numérique et les pratiques numériques : un état de la situation
Authors: Labrousse Marie , Lapointe Marie-Claude
Published: April 2021

Le livre numérique occupe à l’heure actuelle une place plutôt marginale, que ce soit d’un point de vue économique ou social. La situation est particulièrement perceptible au Québec, où seuls 12 % de la population déclarait lire régulièrement des livres numériques en 2014 (Ministère de la Culture et des Communications [MCC], 2016), et où les ventes ont considérablement baissé en 2017 et en 2018 selon les données de l’Observatoire de la culture et des communications du Québec [OCCQ] (Routhier, 2019). Cet insuccès relatif peut apparaitre paradoxal dans la mesure où la lecture de livres papier et un certain nombre de pratiques numériques sont bien répandues au Québec (MCC, 2016; Centre facilitant la recherche et l’innovation dans les organisations [CEFRIO], 2016, 2019). Ce texte veut apporter un éclairage sur l’état des données dont le Québec dispose sur les plans économique et social à propos de la lecture du livre numérique, et le lien avec d’autres pratiques numériques. Ce faisant, il met aussi en lumière que, alors qu’elles pourraient apporter un éclairage pertinent sur la situation, les études portant sur les publics du livre numérique sont peu répandues, et celles portant sur ses non-publics sont plus rares encore.
Recent progress of non-thermal plasma material surface treatment and functionalization
Authors: Zhang Hai-Bao , Chen Qiang ,   Laboratory of Plasma Physics and Materials, Beijing Institute of Graphic Communication, Beijing 102600, China
Published: April 2021

Plasma technology plays an important role in preparing and processing materials nowadays. This review focuses on the applications of non-thermal plasma (NTP) in the surface treatment and functionalization of materials, including the plasma sources for generating plasmas, NTP techniques and specific application fields. The plasma sources include inductively coupled plasma, capacitively coupled plasma, electron cyclotron resonance plasma, surface wave plasma, helicon wave plasma, atmospheric pressure plasma jet, and dielectric barrier discharge plasma. The NTP techniques for material surface treatment and functionalization include plasma surface grafting and polymerization, plasma enhanced chemical vapor deposition, plasma assisted atomic layer deposition, plasma enhanced reactive ion etching, and plasma assisted atomic layer etching. Specific applications of plasma surface treatment and functionalization cover hydrophilic/hydrophobic surface modification, surface micro-nano processing, biological tissue surface treatment, and catalyst surfaces treatment. Finally, the application prospects and development trends of NTP technology for material surface treatment and functionalization are proposed.
The mechanism underlying transient weakness in myotonia congenita
Authors: Myers Jessica H , Denman Kirsten , DuPont Chris , Hawash Ahmed A , Novak Kevin R , Koesters Andrew , Grabner Manfred , Dayal Anamika , Voss Andrew A , Rich Mark M
Published: April 2021

In addition to the hallmark muscle stiffness, patients with recessive myotonia congenita (Becker disease) experience debilitating bouts of transient weakness that remain poorly understood despite years of study. We performed intracellular recordings from muscle of both genetic and pharmacologic mouse models of Becker disease to identify the mechanism underlying transient weakness. Our recordings reveal transient depolarizations (plateau potentials) of the membrane potential to −25 to −35 mV in the genetic and pharmacologic models of Becker disease. Both Na+and Ca2+currents contribute to plateau potentials. Na+persistent inward current (NaPIC) through NaV1.4 channels is the key trigger of plateau potentials and current through CaV1.1 Ca2+channels contributes to the duration of the plateau. Inhibiting NaPIC with ranolazine prevents the development of plateau potentials and eliminates transient weakness in vivo. These data suggest that targeting NaPIC may be an effective treatment to prevent transient weakness in myotonia congenita.
Protomer alignment modulates specificity of RNA substrate recognition by Ire1
Authors: Li Weihan , Crotty Kelly , Garrido Ruiz Diego , Voorhies Mark , Rivera Carlos , Sil Anita , Mullins R Dyche , Jacobson Matthew P , Peschek Jirka , Walter Peter
Published: April 2021

The unfolded protein response (UPR) maintains protein folding homeostasis in the endoplasmic reticulum (ER). In metazoan cells, the Ire1 branch of the UPR initiates two functional outputs—non-conventional mRNA splicing and selective mRNA decay (RIDD). By contrast, Ire1 orthologs from Saccharomyces cerevisiae and Schizosaccharomyces pombe are specialized for only splicing or RIDD, respectively. Previously, we showed that the functional specialization lies in Ire1’s RNase activity, which is either stringently splice-site specific or promiscuous (Li et al., 2018). Here, we developed an assay that reports on Ire1’s RNase promiscuity. We found that conversion of two amino acids within the RNase domain of S. cerevisiae Ire1 to their S. pombe counterparts rendered it promiscuous. Using biochemical assays and computational modeling, we show that the mutations rewired a pair of salt bridges at Ire1 RNase domain’s dimer interface, changing its protomer alignment. Thus, Ire1 protomer alignment affects its substrates specificity.
Simple biochemical features underlie transcriptional activation domain diversity and dynamic, fuzzy binding to Mediator
Authors: Sanborn Adrian L , Yeh Benjamin T , Feigerle Jordan T , Hao Cynthia V , Townshend Raphael JL , Lieberman Aiden Erez , Dror Ron O , Kornberg Roger D
Published: April 2021

Gene activator proteins comprise distinct DNA-binding and transcriptional activation domains (ADs). Because few ADs have been described, we tested domains tiling all yeast transcription factors for activation in vivo and identified 150 ADs. By mRNA display, we showed that 73% of ADs bound the Med15 subunit of Mediator, and that binding strength was correlated with activation. AD-Mediator interaction in vitro was unaffected by a large excess of free activator protein, pointing to a dynamic mechanism of interaction. Structural modeling showed that ADs interact with Med15 without shape complementarity (‘fuzzy’ binding). ADs shared no sequence motifs, but mutagenesis revealed biochemical and structural constraints. Finally, a neural network trained on AD sequences accurately predicted ADs in human proteins and in other yeast proteins, including chromosomal proteins and chromatin remodeling complexes. These findings solve the longstanding enigma of AD structure and function and provide a rationale for their role in biology.
Improvement of deep cross-modal retrieval by generating real-valued representation
Authors: Bhatt Nikita , Ganatra Amit
Published: April 2021

The cross-modal retrieval (CMR) has attracted much attention in the research community due to flexible and comprehensive retrieval. The core challenge in CMR is the heterogeneity gap, which is generated due to different statistical properties of multi-modal data. The most common solution to bridge the heterogeneity gap is representation learning, which generates a common sub-space. In this work, we propose a framework called “Improvement of Deep Cross-Modal Retrieval (IDCMR)”, which generates real-valued representation. The IDCMR preserves both intra-modal and inter-modal similarity. The intra-modal similarity is preserved by selecting an appropriate training model for text and image modality. The inter-modal similarity is preserved by reducing modality-invariance loss. The mean average precision (mAP) is used as a performance measure in the CMR system. Extensive experiments are performed, and results show that IDCMR outperforms over state-of-the-art methods by a margin 4% and 2% relatively with mAP in the text to image and image to text retrieval tasks on MSCOCO and Xmedia dataset respectively.
Histo-CADx: duo cascaded fusion stages for breast cancer diagnosis from histopathological images
Authors: Attallah Omneya , Anwar Fatma , Ghanem Nagia M. , Ismail Mohamed A.
Published: April 2021

Breast cancer (BC) is one of the most common types of cancer that affects females worldwide. It may lead to irreversible complications and even death due to late diagnosis and treatment. The pathological analysis is considered the gold standard for BC detection, but it is a challenging task. Automatic diagnosis of BC could reduce death rates, by creating a computer aided diagnosis (CADx) system capable of accurately identifying BC at an early stage and decreasing the time consumed by pathologists during examinations. This paper proposes a novel CADx system named Histo-CADx for the automatic diagnosis of BC. Most related studies were based on individual deep learning methods. Also, studies did not examine the influence of fusing features from multiple CNNs and handcrafted features. In addition, related studies did not investigate the best combination of fused features that influence the performance of the CADx. Therefore, Histo-CADx is based on two stages of fusion. The first fusion stage involves the investigation of the impact of fusing several deep learning (DL) techniques with handcrafted feature extraction methods using the auto-encoder DL method. This stage also examines and searches for a suitable set of fused features that could improve the performance of Histo-CADx. The second fusion stage constructs a multiple classifier system (MCS) for fusing outputs from three classifiers, to further improve the accuracy of the proposed Histo-CADx. The performance of Histo-CADx is evaluated using two public datasets; specifically, the BreakHis and the ICIAR 2018 datasets. The results from the analysis of both datasets verified that the two fusion stages of Histo-CADx successfully improved the accuracy of the CADx compared to CADx constructed with individual features. Furthermore, using the auto-encoder for the fusion process has reduced the computation cost of the system. Moreover, the results after the two fusion stages confirmed that Histo-CADx is reliable and has the capacity of classifying BC more accurately compared to other latest studies. Consequently, it can be used by pathologists to help them in the accurate diagnosis of BC. In addition, it can decrease the time and effort needed by medical experts during the examination.
Mediterraneibacter catenae SW178 sp. nov., an intestinal bacterium of feral chicken
Authors: Wongkuna Supapit , Ghimire Sudeep , Chankhamhaengdecha Surang , Janvilisri Tavan , Scaria Joy
Published: April 2021

A Gram-positive, coccobacillus, white raised and circular with an entire edge colony, and obligately anaerobic bacterium, strain SW178 was isolated from the cecum content of feral chickens in Brookings, South Dakota, USA. The most closely related strain based on 16S rRNA gene sequence analysis of strain SW178 was Mediterraneibacter torques ATCC 27756T (Ruminococcus torques ATCC 27756T) with 96.94% similarity. The genome of strain SW178 is 3.18 Mbp with G+C content of 46.9 mol%. The optimal temperature and pH for growth in modified brain heart infusion (BHI-M) medium were 45 °C and pH 7.5, respectively. The sole carbon sources of the strain were dextrin, L-fucose, D-galacturonic, α-D-glucose, L-rhamnose and D-sorbitol. The primary cellular fatty acids were C14 : 0, C16 : 0 and C16 : 0 dimethyl acetal (DMA). Based on the genotypic and phenotypic comparison, we proposed that strain SW178 belong to the genus Mediterraneibacter in the family Lachnospiraceae as a novel species, in which the name Mediterraneibacter catenae is proposed. The type strain is SW178 (= DSM 109242T = CCOS 1886T).
Design of Affordable Solar Photovoltaic Systems in Nigeria: A Cost Implication Analysis
Authors: Izuchukwu Oji-Okoro , Peace Aimua Ehigocho
Published: April 2021

The demand for electricity generation around the world has significantly increased over the past decades, this is due to the growth in the world’s population, industrialization, economic activities and technological innovation; with various countries opting for alternative sources of renewable energy sources to replace the use of fossil fuel sources of energy whose availability has rapidly declined. The Nigeria power sector has experienced a major setback in power generation, distribution and the power consumption rates in the country has been very low compare to other African countries in electricity per capita. This study examines the designing of an affordable solar photovoltaic (PV) system in Nigeria using the cost and benefit method. Furthermore, a proposed PV electrification model was designed to calculate the Financial Internal Rate of Return (FIRR), Net Present Value (NPV) and Sensitivity analysis of installing a mini-grid system within the Federal Capital Territory (FCT). The result however showed that the system efficiency was calculated as FIRR was 17.5% and the NPV was at N320,897,841 which suggest that the project on this scale is economically viable in the FCT, making the life cycle cost per kWh, including the grid extension cost relatively low. Furthermore, the result obtained revealed that electricity generated from solar energy can contribute to the country’s economy and also eliminate or cut the pollution and toxic waste from the burning excess fossil fuel that releases large amount of CO2 into the atmosphere which affects human health and the environment.
Riding the Wave of New Opportunities in Boron Chemistry
Authors: Fernández Elena
Published: April 2021

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Cathode‐Electrolyte‐Interphase Film Formation on a LiNiO2 Surface in Conventional Aqueous Electrolytes: Simple Method to Improve the Electrochemical Performance of LiNiO2 Electrodes for Use in Aqueous Li‐Ion Batteries
Authors: Lee Changhee , Yokoyama Yuko , Kondo Yasuyuki , Miyahara Yuto , Abe Takeshi , Miyazaki Kohei
Published: April 2021

Passivation films, the so‐called solid–electrolyte interphase and cathode–electrolyte interphase (CEI), are considered to be essential for the operation of rechargeable batteries because they have a positive impact on electrochemical performance including cyclability. In the field of aqueous Li‐ion batteries (ALIBs) to date, it is generally accepted that these films can only be formed in super‐concentrated electrolytes containing fluorine‐based organic anions such as N(SO2CF3)2 and SO3CF3. This study demonstrates for the first time that a CEI film can be created on a LiNiO2 (LNO) electrode in conventional aqueous electrolytes and improve electrochemical performance such as reversible capacities and cyclability. The results reveal that a CEI film, mainly composed of Li2CO3 and LiOH, is formed on the LNO surface in a saturated LiNO3 aqueous electrolyte containing LiOH beginning at the first de‐intercalation of Li+ ions, suppressing side reactions between the surface and aqueous electrolyte, and improving the recovery rate of structural changes of LNO during the charge/discharge process. As a result, this study suggests that LNO has great potential for application as a cathode material for high energy density ALIBs.
Na9Bi5Os3O24: A Diamagnetic Oxide Featuring a Pronouncedly Jahn–Teller‐Compressed Octahedral Coordination of Osmium(VI)
Authors: Thakur Gohil S. , Reuter Hans , Ushakov Alexey V. , Gallo Gianpiero , Nuss Jürgen , Dinnebier Robert E. , Streltsov Sergey V. , Khomskii Daniel I. , Jansen Martin
Published: April 2021

The Jahn–Teller (JT) theorem constitutes one of the most fundamental concepts in chemistry. In transition‐element chemistry, the 3d4 and 3d9 configurations in octahedral complexes are particularly illustrative, where a distortion in local geometry is associated with a reduction of the electronic energy. However, there has been a lasting debate about the fact that the octahedra are found to exclusively elongate. In contrast, for Na9Bi5Os3O24, the octahedron around Os6+(5d2) is heavily compressed, lifting the degeneracy of the t2g set of 5d orbitals such that in the sense of a JT compression a diamagnetic ground state results. This effect is not forced by structural constraints, the structure offers sufficient space for osmium to shift the apical oxygen atoms to a standard distance. The relevance of these findings is far reaching, since they provide new insights in the hierarchy of perturbations defining ground states of open shell electronic systems.
CeCl3/n‐BuLi: Unraveling Imamoto's Organocerium Reagent
Authors: Berger Tassilo , Lebon Jakob , Maichle‐Mössmer Cäcilia , Anwander Reiner
Published: April 2021

CeCl3(thf) reacts at low temperatures with MeLi, t‐BuLi, and n‐BuLi to isolable organocerium complexes. Solvent‐dependent extensive n‐BuLi dissociation is revealed by7Li NMR spectroscopy, suggesting “Ce(n‐Bu)3(thf)x” or solvent‐separated ion pairs like “[Li(thf)4][Ce(n‐Bu)4(thf)y]” as the dominant species of the Imamoto reagent. The stability of complexes Li3Ln(n‐Bu)6(thf)4increases markedly with decreasing LnIIIsize. Closer inspection of the solution behavior of crystalline Li3Lu(n‐Bu)6(thf)4and mixtures of LuCl3(thf)2/n‐BuLi in THF indicates occurring n‐BuLi dissociation only at molar ratios of <1:3. n‐BuLi‐depleted complex LiLu(n‐Bu)3Cl(tmeda)2was obtained by treatment of Li2Lu(n‐Bu)5(tmeda)2with ClSiMe3, at the expense of LiCl incorporation. Imamoto's ketone/tertiary alcohol transformation was examined with 1,3‐diphenylpropan‐2‐one, affording 99 % of alcohol.
The effects of processing variables on electrospun poly(ethylene glycol) fibrous hydrogels formed from the thiol‐norbornene click reaction
Authors: Sharma Sadhana , Monteleone Nicholas , Kopyeva Irina , Bryant Stephanie J.
Published: April 2021

Electrospinning has been used to create scaffolds with tunable micro/nano architecture, stiffness, and porosity to mimic native extracellular matrix. This study investigated the effects of electrospinning parameters and hydrogel formulation (solvent and crosslinker type) on the architecture and properties of fibrous poly(ethylene glycol) (PEG) hydrogels formed from a photoclick thiol‐norbornene reaction. Fibrous hydrogels were prepared using hydrogel precursors (four‐arm PEG norbornene and multi‐thiol crosslinker), sacrificial poly(ethylene oxide) (PEO, 400 kDa), and photoinitiator (I2959) in either 2,2‐triflouroethanol (TFE) or water. Three thiol crosslinkers‐ 2,2′‐(ethylenedioxy)diethanethiol (EDT), pentaerythritol tetrakis(3mercaptopropionate) (PTMP), and PEG dithiol (PEGDT)‐ were investigated. Fibrous PEG networks with uniform fibers were produced at applied voltages of 10 or 12 kV for TFE and 16 kV for water. Fiber diameters of electrospun hydrogels were largely affected by the solvent when combined with PEO concentration and ranged from 0.5 to 3.5 mm in dry state. While the effect of crosslinker type on fiber diameter, morphology, and porosity of the fibrous hydrogel was minimal, it did modulate its shear modulus. To this end, this study provides the groundwork for selecting processing parameters to achieve desired properties of fibrous PEG thiol‐norbornene hydrogels for intended tissue engineering applications ranging from neural, cardiovascular to musculoskeletal.
Effect of nitrogen pretreatment on the skin‐core structure of thermal oxidative stabilization polyacrylonitrile fibers
Authors: Ge Yuan , Fu Zhongyu , Deng Yunjiao , Zhang Huixuan
Published: April 2021

Polyacrylonitrile precursor was pretreated under nitrogen to study the effect of the extent of cyclization of pretreated fibers on the chemical structure, crystal structure and skin‐core structure of thermal oxidative stabilization (TOS) fibers. Based on the FTIR spectra, the cyclization degree of pretreated fibers was quantitatively calculated by a combination of peak‐fitting and second‐derivative operations. Combining the results of wide‐angle X‐ray diffraction, Raman spectroscopy and scanning electron microscope analysis, pretreatment was beneficial to increase the cyclized structure of TOS fibers, but inhibited the oxidation reactions in the TOS process. As the increase of cyclization degree of pretreated fibers, the oxygen content and crystal size of TOS fibers decreased and the crystal interplanar spacing increased; in the skin layer of TOS fibers, the ID/IGratio increased and brittle fracture area decreased. When the cyclization degree of pretreated fibers was in the range of 10%–35%, the skin‐core structure of TOS fibers was weakened, which demonstrated that proper pretreatment before TOS process can improve the skin‐core structure.
In vitro evaluation of 99mTc‐sultamicillin for infection imaging
Authors: Durkan Kubra , Tuncel Ayca , Yurt Fatma
Published: April 2021

Early detection of the site of infection non‐invasively with radiolabeled molecules is important for the success of treatment. Technetium‐99m labeled antibiotics have the potential to discriminate between bacterial infection and sterile inflammation. Sultamicillin is the tosylate salt of the double ester of sulbactam plus ampicillin. In this study, sultamicillin was labeled with 99mTc according to the stannous chloride method. Quality control studies of radiolabeled sultamicillin were performed by radiochromatographic methods. In vitro binding assays were performed in live and heat‐killed gram‐positive Staphylococcus aureus and gram‐negative Escherichia coli strains. The radiolabeling yield of 99mTc‐sultamicillin was determined as 97.8% ± 3.1% (n = 5). The maximum bacterial uptake of 99mTc‐sultamicillin was 80.7% ± 11.00% at 4 h for living S. aureus and 93.2% ± 4.40% at 2 h for E. coli. Bacterial uptake study results show that sultamicillin has the potential to be a nuclear imaging agent, especially in infections caused by gram‐negative E. coli and gram‐positive S. aureus.
Identifying anatomical structures on ultrasound: assistive artificial intelligence in ultrasound‐guided regional anesthesia
Authors: Bowness James , Varsou Ourania , Turbitt Lloyd , Burkett‐St Laurent David
Published: April 2021

Ultrasound‐guided regional anesthesia involves visualizing sono‐anatomy to guide needle insertion and the perineural injection of local anesthetic. Anatomical knowledge and recognition of anatomical structures on ultrasound are known to be imperfect amongst anesthesiologists. This investigation evaluates the performance of an assistive artificial intelligence (AI) system in aiding the identification of anatomical structures on ultrasound. Three independent experts in regional anesthesia reviewed 40 ultrasound scans of seven body regions. Unmodified ultrasound videos were presented side‐by‐side with AI‐highlighted ultrasound videos. Experts rated the overall system performance, ascertained whether highlighting helped identify specific anatomical structures, and provided opinion on whether it would help confirm the correct ultrasound view to a less experienced practitioner. Two hundred and seventy‐five assessments were performed (five videos contained inadequate views); mean highlighting scores ranged from 7.87 to 8.69 (out of 10). The Kruskal–Wallis H‐test showed a statistically significant difference in the overall performance rating (χ2[6] = 36.719, asymptotic p < 0.001); regions containing a prominent vascular landmark ranked most highly. AI‐highlighting was helpful in identifying specific anatomical structures in 1330/1334 cases (99.7%) and for confirming the correct ultrasound view in 273/275 scans (99.3%). These data demonstrate the clinical utility of an assistive AI system in aiding the identification of anatomical structures on ultrasound during ultrasound‐guided regional anesthesia. Whilst further evaluation must follow, such technology may present an opportunity to enhance clinical practice and energize the important field of clinical anatomy amongst clinicians.
Cyano Derivatives of 7‐Aminoquinoline That Are Highly Emissive in Water: Potential for Sensing Applications
Authors: Chang Kai‐Hsin , Chao Wei‐Chih , Yang Yu‐Hsuan , Wu Cheng‐Ham , Li Zhi‐Bin , Chen Hung‐Che , Chou Yi‐Te , Annie Ho Ja‐an , Li Xin‐Cheng , Peng Yu‐Chiang , Liao Yu‐Chan , Liu Kuan‐Miao , Chao Chi‐Min , Chou Pi‐Tai
Published: April 2021

6‐Cyano‐7‐aminoquinoline (6CN−7AQ) and 3‐cyano‐7‐aminoquinoline (3CN−7AQ) were synthesized and found to exhibit intense emission with quantum yield as high as 63 % and 85 %, respectively, in water. Conversely, their derivatives 6‐cyano‐7‐azidoquinoline (6CN−7N3Q) and 3‐cyano‐7‐azidoquinoline (3CN−7N3Q) show virtually no emission, which makes them suitable to be used as recognition agents in azide reactions based on fluorescence recovery. Moreover, conjugation of 6CN−7AQ with a hydrophobic biomembrane‐penetration peptide PFVYLI renders a nearly non‐emissive 6CN−7AQ‐PFVYLI composite, which can be digested by proteinase K, recovering the highly emissive 6CN−7AQ with ∼200‐fold enhancement. The result provides an effective early confirmation for RT‐qPCR in viral detection.
Catalytic Gold Chemistry: From Simple Salts to Complexes for Regioselective C−H Bond Functionalization
Authors: Praveen Chandrasekar , Dupeux Aurélien , Michelet Véronique
Published: April 2021

Gold coordinated to neutral phosphines (R3P), N‐heterocyclic carbenes (NHCs) or anionic ligands is catalytically active in functionalizing various C−H bonds with high selectivity. The sterics/electronic nature of the studied C−H bond, oxidation state of gold and stereoelectronic capacity of the coordinated auxiliary ligand are some of the associated selectivity factors in gold‐catalyzed C−H bond functionalization reactions. Hence, in this review a comprehensive update about the action of different types of gold catalysts, from simple to sophisticated ones, on C−H bond reactions and their regiochemical outcome is disclosed. This review also highlights the catalytic applications of Au(I)‐ and Au(III)‐species in creating new opportunities for the regio‐ and site‐selective activation of challenging C−H bonds. Finally, it also intends to stress the potential applications in selective C−H bond activation associated with a variety of heterocycles recently described in the literature.
Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
Authors: Chen Junjun , Hua Kaimin , Liu Xiaofang , Deng Yuchao , Wei Baiyin , Wang Hui , Sun Yuhan
Published: April 2021

Performing carbonylation without the use of carbon monoxide for high‐value‐added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear‐selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
Complementary switching enabled cascaded boost‐buck‐boost (BS‐BB) and buck‐boost‐buck (BB‐BU) converters
Authors: Naresh SVK , Peddapati Sankar
Published: April 2021

In this paper, two cascaded buck‐boost nature converters are developed; one converter is capable of producing high step‐up gain, and the other converter addresses high step‐down gain. In proposed converters, for a given voltage gain, two distinct duty ratios are possible due to their ability in handling complementary switching schemes. This feature is effective for voltage‐sensitive applications like LED systems. The operation principle, steady‐state analysis, and the design of the passive components for each switching scheme are presented for the proposed converters. Comparative analysis with competitive converters profound the merits of the proposed converters in terms of voltage gain and the continuous nature of the output. Experiments are conducted on both proposed converters for simultaneous and complementary switching schemes, and they validate the theoretical steady‐state performance.
Cytomorphometry and morphology analysis of human papillomavirus type 16 in liquid‐based cervical cytology samples
Authors: Safi Oz Zehra , Onak Kandemir Nilufer , Kokturk Furuzan , Ozdamar Sukru Oguz
Published: April 2021

Background

Human papillomavirus (HPV) is the main causal factor of cervical carcinoma. HPV 16 is one of the most prominent oncogenic types. We aimed to evaluate the cytomorphometric and morphological alterations caused by HPV 16 in liquid‐based cytology (LBC).

Methods

The Cobas 4800 HPV system was used for the detecting and typing HPV DNA in cervical specimens. In this study, 30 HPV 16 positive and 30 HPV 16 negative cervical samples were evaluated for micronuclei (MN), nonclassical cytologic abnormalities, and the nuclear‐to‐cytoplasmic ratio. Nuclear and cellular areas were evaluated using image analysis software and the nuclear‐to‐cytoplasm ratio was calculated. All analyses were performed blinded to the patients' HPV status. Statistical evaluation was carried out using the χ2 and Fisher test; P‐values < .05 were considered significant.

Results

The frequencies of micronucleated cells and koilocytes were higher in the HPV 16 infected group (P < .05). Cells with perinuclear halo in control group were higher than the HPV 16 infected group (P < .05). The mean nuclear‐to‐cytoplasm ratio in HPV 16 patients was higher than the control value, but the difference was not statistically significant.

Conclusion

LBC can be used to detect morphological and morphometric changes. HPV 16 induces the formation of MN and koilocytosis. The evaluation of MN could provide additional information in monitoring genomic instability and of koilocytes could provide information about damage to the cytoskeleton filaments in HPV infection. Further studies are needed to investigate the effects of HPV‐18 and other high‐risk HPV types on the cell size and nucleus‐to‐cytoplasm ratio.
Sulfide‐Based Nickel‐Plated Fabrics for Foldable Quasi‐Solid‐State Supercapacitors
Authors: Wei Zhihao , Liu Tao , Zhang Liuyang , Yu Jiaguo
Published: April 2021

Smart wearable market is burgeoning, and flexible energy storage is crucial to cope with its development. The commonly‐used metal‐based current collectors are heavy with limited flexibility. Other carbon‐based current collectors are expensive and fragile. Moreover, the poor interface between active material and current collector leads to unsatisfactory stability. Herein, these two issues are attempted to be solved by using cheap and lightweight polyester‐based fabrics as well as in‐situ growth. A deposited thin layer of nickel on the fabrics not only enhances the conductivity, but also serves as the sacrificial precursor for the growth of active materials. Thus, intimate contact is secured via chemical bonding. The electrode with ternary (metal‐inorganic‐organic) component shows excellent electrochemical performance. Namely, high areal capacity is realized (2.2 C cm−2 at 2 mA cm−2), which is far superior to its rigid nickel‐foam‐based counterpart. Furthermore, an all‐solid‐state supercapacitor device was assembled. The device provides an areal capacity of 2.03 C cm−2 at the current density of 2 mA cm−2. It realizes an energy density of 0.45 mWh cm−2 when the power density is 1.6 mW cm−2. This work offers a feasible and cost‐efficient way for fabricating electrode materials with excellent performance for portable supercapacitors.
Mixing characteristics of a bubble mixing microfluidic chip for genomic DNA extraction based on magnetophoresis: CFD simulation and experiment
Authors: Sun Lin , K. Siddique Muhammad , Wang Lei , Li Songjing
Published: April 2021

Mixing a small amount of magnetic beads and regents with large volume samples evenly in microcavities of a microfluidic chip is always the key step for the application of microfluidic technology in the field of magnetophoresis analysis. This article proposes a microfluidic chip for DNA extraction by magnetophoresis, which relies on bubble rising to generate turbulence and microvortices of various sizes to mix magnetic beads with samples uniformly. The construction and working principle of the microfluidic chip are introduced. CFD simulations are conducted when magnetic beads and samples are irritated by the generation of gas bubbles with the variation of supply pressures. The whole mixing process in the microfluidic chip is observed through a high‐speed camera and a microfluidic system when the gas bubbles are generated continuously. The influence of supply pressure on the mixing characteristics of the microfluidic chip is investigated and discussed with both simulation and experiments. Compared with magnetic mixing, bubble mixing can avoid the magnetic beads gather phenomenon caused by magnetic forces and provide a rapid and high efficient solution to realize mixing small amount of regents in large volume samples in a certain order without complex moving structures and operations in a chip. Two applications of mixing with the proposed microfluidic chip are also carried out and discussed.
Chemostratigraphy and pyrite morphology across theWuchiapingian‐Changhsingianboundary in the Middle Yangtze Platform, South China
Authors: Wei Hengye , Tang Wei , Gu Heng , Fu Xiugen , Zhang Xuan
Published: April 2021

Separated mass extinction occurred at the beginning and the ending of the Late Permian, called end‐Guadalupian and end‐Permian mass extinctions, respectively. Palaeoenvironmental changes in the middle of the Late Permian could give more insights into the environmental causes for the Permian extinctions. In this contribution, we analysed carbonate carbon isotope and carbonate‐associated‐sulphate sulphur isotope compositions to constrain the carbon and sulphur cycles across the Wuchiapingian‐Changhsingian boundary (WCB) at Yanglinqiao in Zigui in the Middle Yangtze Platform. Pyrite morphology and pyrite framboids size distribution were used to analyse redox conditions variations across the WCB. Our results show that an episodic euxinia event occurred across the WCB. This anoxic/euxinic event across the WCB was a global event, and was mainly caused by the upwelling during the cooling event. Both inorganic‐ and organic‐carbon isotopic compositions show covariance of a negative shift across the WCB at Yanglinqiao and other places in South China. This carbon‐isotopic negative excursion across the WCB was a regional carbon cycle perturbation and may be linked to the light‐carbon input from the upwelling water mass. Although the seawaterδ34S across the WCB recorded a negative excursion in two locations in South China, it reflects the riverine input of32S‐enriched sulphate and represent a regional signal. These environmental anomalies such as oceanic anoxia/euxinia, global carbon cycle perturbation, cooling, end of the Emeishan large igneous province movement across the WCB may have delayed the recovery from the end‐Guadalupian mass extinction.