bluuebunny/crossref_metadata_2025 huggingface dataset:
Ascorbic Acid Supplementation During Endurance Training in Hypertensive Men: Effect on Catalase, Nitric Oxide and Blood Pressure
Authors: Alishahi Ailin , Azizbeigi Kamal , Mohammadzadeh Salamat Khalid , Yektayar Mozafar
Published: March 2021

Objectives: The aim of this research was to study the influence of consuming ascorbic acid during high -intensity endurance training on catalase (CAT), nitric oxide (NO) concentration, and blood pressure (BP) in hypertensive male. Methods: 36 hypertensive male voluntary participated in the present study and randomly assigned into endurance training-ascorbic acid (HTC; n = 9), endurance training-placebo (HTP; n = 9), ascorbic acid (AA; n = 9) and control (n = 9). The exercise protocol was including continuous running exercise training with gradually increasing of duration and intensity, 3 times a week for 10 weeks. The supplement groups consumed daily 500 mg of ascorbic acid, and the placebo group consumed the same amount of maltodextrin. Fasting blood samples was gathered before the beginning exercise protocol and one day after last session for analyzing CAT and NO. Results: Results showed that activity of CAT and NO concentration were significantly increased only in the HTC and HTP (P ≤ 0.05). Also, in the HTP and HTC, a significant decrease observed in the systolic and diastolic (P ≤ 0.05). Nevertheless, there was no significant difference between HTC and HTP in SBP and DBP (P > 0.05). Conclusions: Finally, we concluded that, continuous running exercise training has positive effect on the catalase and oxide nitric activity, and can improve blood pressure in the hypertensive men. Anyway, combined the high -intensity aerobic training with ascorbic acid may have not more efficacy.
The Relationship between Time Management and Academic Burnout with the Mediating Role of Test Anxiety and Self-efficacy Beliefs among University Students
Authors: Kordzanganeh Zahra , Bakhtiarpour Saeed , Hafezi Fariba , Dashtbozorgi Zahra
Published: March 2021

Background: Academic burnout is one of the most important problems throughout all levels of the education system. Objectives: The present study aimed to investigate the relationship between time management and academic burnout with the mediating role of test anxiety and self-efficacy beliefs among university students in 2019. Methods: The study was a descriptive correlation performed by path analysis. The statistical population included all students of Islamic Azad University of Ahvaz and 222 of which were selected as the sample of the study using convenience sampling. The research instruments included the Academic Burnout Questionnaire, the Time Management Questionnaire, the test anxiety inventory, and the General Self-Efficacy Scale. The proposed model was evaluated using path analysis with AMOS software. Results: A direct and positive relationship was observed between time management and self-efficacy beliefs (β = 0.345, P = 0.0001) and between test anxiety and academic burnout (β = 0.515, P = 0.0001). The relationship between time management and test anxiety (β = -0.586, P=0.001) and between self-efficacy beliefs and academic burnout (β = -0.305, P = 0.0001) was negative. The relationship between time management and academic burnout was not significant (β = -0.051, P = 0.425). The results indicated that test anxiety and self-efficacy beliefs had a mediating role in the relationship between time management and academic burnout (β = -3.964, P = 0.001). Conclusions: According to research results, the proposed model had good fitness and is considered an important step in identifying the effective factors in students’ academic burnout.
Role osobních zájmen v odborném anglicky psaném diskurzu a rozvoj dovednosti akademického psaní
Authors: Stanislavová Veronika
Published: March 2021

The aim of the literature review is to map the research field associated with the topic of the frequency use of personal pronouns in written academic discourse of university students. The work discusses the main concepts, presents the analyses of 14 empirical studies, and answers two research questions: What are the main findings of the current research? What methods and approaches are preferred in this type of research?
Des méthodes pour évaluer l’état de conservation des habitats humides sur l’ensemble du territoire métropolitain
Authors: MISTARZ Margaux
Published: March 2021

Un des objectifs de la directive Habitats-Faune-Flore est le maintien, ou la restauration, dans un état de conservation (EC) favorable des habitats et des espèces d’intérêt communautaire (HIC) listés dans ses annexes. Afin de répondre à cet objectif, le ministère en charge de l’Écologie a confié au Muséum national d’Histoire naturelle la mise en place de méthodes d’évaluation de l’EC des HIC à l’échelle des sites Natura 2000. Ces méthodes doivent être simples, reproductibles et standardisées sur l’ensemble du territoire métropolitain. Les travaux sont engagés depuis 2008 et ont vu paraître plusieurs guides méthodologiques traitant des habitats forestiers, dunaires, agropastoraux, marins et lagunaires. Pour les habitats humides, un premier travail a porté sur les eaux courantes en 2013. Se sont succédés depuis plusieurs travaux, notamment sur les eaux dormantes, les habitats tourbeux ou encore les landes humides atlantiques. Cet article vise à présenter le principe méthodologique de l’évaluation de l’EC à l’échelle des sites, ainsi que le processus d’élaboration des grilles d’évaluation. Il vise également à faire le bilan de l’ensemble des méthodes disponibles à ce jour pour évaluer l’EC des HIC humides. À l’heure actuelle, 98 % des HIC humides recensés sur le territoire métropolitain sont couverts par une méthode d’évaluation ou ont fait l’objet d’une première approche méthodologique.
Docência e a aula como ensaio
Authors: Matos Sônia Regina da Luz , Schuler Betina
Published: March 2021

Na atualidade, temos uma das políticas nacionais de formação de professores se efetivando via Programa Institucional de Bolsa de Iniciação à Docência Programa (Pibid)1. Por meio dessa macropolítica, o projeto Práticas curriculares de escrita e leitura e a formação de professores participa desse espaço político, articulando a pesquisa universitária e a escola pública. O artigo versa sobre o tema aula a partir do aporte conceitual dos filósofos Nietzsche e Deleuze. Com eles, na primeira parte do artigo, definimos a docência como vontade criadora e a articulamos à noção de aula como ensaio. Apresentamos, em seguida, a operação da crítica genealógica como um dos principais elementos didáticos da aula como ensaio. A pesquisa, ao assumir esse posicionamento conceitual, apresenta, na terceira parte do texto a experimentação do elemento didático da crítica genealógica na aula intitulada “Oficinando com as bruxas: entre o bem e o mal”, desenvolvida junto a uma turma dos anos iniciais de uma escola pública via o Pibid. A partir disso, a personagem bruxa foi levada ao território da crítica genealógica como elemento didático da aula como ensaio, possibilitando a problematização da valoração dos valores e a desnaturalização de estereótipos.
Reviewers Wanted
Authors: Varnum Kenneth J.
Published: March 2021

Together with one of the other journals published by ALA’s Core division, Information Technology and Libraries(ITAL) and Library Leadership and Management (LL&M) invite applications for peer reviewers. Serving as a reviewer is a great opportunity for individuals from all types of libraries and with a wide variety of experience to contribute to scholarship within our chosen profession.
Marx et la critique de la technique : réflexions à partir des Grundrisse et du Capital
Authors: Ouellet Maxime
Published: March 2021

Cet article consiste en une réflexion sur la nature de la technique dans les écrits de Marx. Dans un premier temps, la manière dont Marx aborde la question de la technique à partir de son ontologie de l’autoproduction de l’être générique sera présentée. Par la suite, la critique marxienne du machinisme sera analysée à l’aune de son ontologie de l’autoproduction. L’analyse du machinisme proposée par Marx dans le chapitre XIII du Capital permettra de faire un retour critique sur le désormais célèbre passage des Grundrisse communément désigné en tant que « Fragment sur les machines », et qui est mobilisé par de nombreux théoriciens contemporains du post-capitalisme tels que les cognitivistes ou les accélérationnistes. Contre leur vision productiviste, il s’agira de proposer une lecture qui permettrait de dépasser les apories auxquelles mènent les analyses unilatérales du développement technologique sous le capitalisme, que celles-ci soient progressistes ou romantiques.
L’éternelle saison des amours : la soumission virtuelle de la pratique sociale au capital
Authors: Duhaime Éric N.
Published: March 2021

Cet article vise à problématiser les enjeux qui se rattachent au rôle de plus en plus central que jouent la science et la technologie dans l’économie. Développant notre réflexion à partir de l’oeuvre de Marx, nous cherchons d’abord à rendre compte des concepts de soumission formelle et de soumission réelle qu’il développa à son époque. En tenant compte du passage du capitalisme industriel au capitalisme avancé, nous proposons ensuite le concept de soumission virtuelle de la pratique sociale au capital afin de problématiser les enjeux liés à une nouvelle stratégie monopolistique qui fut mise en place par de grandes corporations au milieu du XXe siècle et qui conjugue la R-D et le marketing, c’est-à-dire la production et la commercialisation d’inventions brevetées. Il en résulte alors un contrôle sur la détermination des objets d’usage futurs qui viendront prendre place dans nos sociétés, lequel renvoie précisément au concept de soumission virtuelle de la pratique sociale au capital.
Palaeohistology and palaeopatology of an Aeolosaurini (Sauropoda: Titanosauria) from Morro do Cambambe (Upper Cretaceous, Brazil)
Authors: S. BRUM Arthur , L. N. BANDEIRA Kamila , HOLGADO Borja , G. SOUZA Lucy , V. PÊGAS Rodrigo , M. SAYÃO Juliana , A. CAMPOS Diogenes , Alexander Alexander
Published: March 2021

A recent publication of fossil bones of titanosaurs assigned to Aeolosaurini from the Morro do Cambambe site (Mato Grosso state, Brazil, Upper Cretaceous) reported anomalous growth in some of them. Here, we present osteohistological sections of elements to understand not only the microstructure and growth of such bones, but also the nature of those anomalies. The primary bone of all specimens consisted of a variation of the fibrolamellar complex, with the inner cortex being rich in woven bone with dispersed longitudinal canals, while the outer cortex was parallel-fibred with rows of longitudinal canals, interlayered by Lines of Arrested Growth (LAGs). We identified a maximum of two LAGs in the cervical rib and haemal arch, and four in the dorsal rib. The haemal arch shows an External Fundamental System (EFS) in most sections. The advanced remodelling and variation of the fibrolamellar bone in the cortex suggests that all the specimens represent individuals that reached sexual maturity. However, the haemal arch was distinct due to the wide distribution of EFS. The dorsal rib exhibited periosteal and endosteal outgrowth. Such microstructure was assigned to a reactive bone due to an intra-thoracic infection (a pneumonia, probably related to a tuberculosis), which is the first report in a non-avian dinosaur. The microstructure resembles the medullary bone recovered in dinosaurs, which suggests that further studies of medullary bone in thoracic bones should also regard the pathological cases.
Xanastur (Brachiopoda, Stringocephalacea) nomen novum pro Xana García-Alcalde, 1972 (non Xana Kurdjumov, 1917, Hymenoptera, Hexapoda)
Authors: GARCÍA-ALCALDE Jenaro L.
Published: March 2021

García-Alcalde (1972) proposed the new genus Xana (type species Xana bubo García-Alcalde, 1972) for a terebratulid brachiopod included in the superfamily Stringocephalacea from the Lower Devonian of the Cantabrian Mountains (Northwestern Spain). In an email message sent on April 3, 2018, the entomologist Dr. Eduardo I. Faundez, from the Patagonia Institute, Magallanes University, Chile, warned the author that Xana was a name previously used by Kurdjumov (1917) for a hymenopteran genus. Xana García-Alcalde, 1972 would be so a later homonym of Xana Kurdjumov, 1917. In accordance with articles 52.3, 52.4, 53.2, 60.3 of the International Code of Zoological Nomenclature (ICZN) (2000), it is proposed here to replace the invalid name with the new name Xanastur.
A very general binomial matrix
Authors:   University of Florida, Betthauser Leo , Deveci Ömür ,   Kafkas University, Hiller Josh ,   Adelphi University
Published: March 2021

We define the very general binomial matrix and find its eigendecomposition over arbitrary rings when such a decomposition is possible. Using this decomposition, we are able to compute the order of several varieties of Pascal’s matrices.
Characterization of ideals of rhotrices over a ring and its applications
Authors:   Dharmsinh Desai University, Patil Kailash M.
Published: March 2021

We define higher order rhotrices over a commutative unital ring S and obtain a ring \mathcal{R}_n(S) of rhotrices of the order n \in \mathbb{N}. We characterize the ideals and maximal ideals of \mathcal{R}_n(S). As a particular case, we record ideals of rhotrix rings over integers and rhotrix algebras over complex plane \mathbb{C}. As an application, we characterize the maximal ideals of the commutative unital Banach algebra \mathcal{R}_n(\mathbb{C}).
Catalan transform of the k-Pell, k-Pell–Lucas and modified k-Pell sequence
Authors:   Erzincan Binali Yıldırım University, Taştan Merve , Özkan Engin ,   Erzincan Binali Yıldırım University
Published: March 2021

In this study, we present the Catalan transforms of the k-Pell sequence, the k-Pell–Lucas sequence and the Modified k-Pell sequence and examine the properties of the sequences. Then we apply the Hankel transform to the Catalan transforms of the k-Pell sequence, the Catalan transform of the k-Pell–Lucas sequence and the Catalan transform of the Modified k-Pell sequence. Also, we obtain the generating functions of the Catalan transform of the k-Pell sequence, k-Pell–Lucas sequence and Modified k-Pell sequence. Furthermore, we acquire an interesting characteristic related to the determinant of the Hankel transform of the sequences.
Odd/even cube-full numbers
Authors:   Department of Mathematics Statistics and Computer Science, Faculty of Liberal Arts and Science, Kasetsart University, Puttasontiphot Tippawan , Srichan Teerapat ,   Department of Mathematics, Faculty of Science, Kasetsart University
Published: March 2021

In this paper we use an elementary method to give an asymptotical ratio of odd to even cube-full numbers and show that it is asymptotically 1 : 1 + 2^{−1/3} + 2^{−2/3}.
On a Diophantine equation arising in the history of mathematics
Authors:   Babes-Bolyai University, Sándor József
Published: March 2021

In the present paper, we offer the complete solution to a Diophantine equation, considered by S. Naranan [2]. For the history of the problem, see also L. E. Dickson [1].
Swarming bacteria undergo localized dynamic phase transition to form stress-induced biofilms
Authors: Grobas Iago , Polin Marco , Asally Munehiro
Published: March 2021

Self-organized multicellular behaviors enable cells to adapt and tolerate stressors to a greater degree than isolated cells. However, whether and how cellular communities alter their collective behaviors adaptively upon exposure to stress is largely unclear. Here, we investigate this question using Bacillus subtilis, a model system for bacterial multicellularity. We discover that, upon exposure to a spatial gradient of kanamycin, swarming bacteria activate matrix genes and transit to biofilms. The initial stage of this transition is underpinned by a stress-induced multilayer formation, emerging from a biophysical mechanism reminiscent of motility-induced phase separation (MIPS). The physical nature of the process suggests that stressors which suppress the expansion of swarms would induce biofilm formation. Indeed, a simple physical barrier also induces a swarm-to-biofilm transition. Based on the gained insight, we propose a strategy of antibiotic treatment to inhibit the transition from swarms to biofilms by targeting the localized phase transition.
Ancient DNA reveals the lost domestication history of South American camelids in Northern Chile and across the Andes
Authors: Diaz-Maroto Paloma , Rey-Iglesia Alba , Cartajena Isabel , Núñez Lautaro , Westbury Michael V , Varas Valeria , Moraga Mauricio , Campos Paula F , Orozco-terWengel Pablo , Marin Juan Carlos , Hansen Anders J
Published: March 2021

The study of South American camelids and their domestication is a highly debated topic in zooarchaeology. Identifying the domestic species (alpaca and llama) in archaeological sites based solely on morphological data is challenging due to their similarity with respect to their wild ancestors. Using genetic methods also presents challenges due to the hybridization history of the domestic species, which are thought to have extensively hybridized following the Spanish conquest of South America that resulted in camelids slaughtered en masse. In this study, we generated mitochondrial genomes for 61 ancient South American camelids dated between 3,500 and 2,400 years before the present (Early Formative period) from two archaeological sites in Northern Chile (Tulán-54 and Tulán-85), as well as 66 modern camelid mitogenomes and 815 modern mitochondrial control region sequences from across South America. In addition, we performed osteometric analyses to differentiate big and small body size camelids. A comparative analysis of these data suggests that a substantial proportion of the ancient vicuña genetic variation has been lost since the Early Formative period, as it is not present in modern specimens. Moreover, we propose a domestication hypothesis that includes an ancient guanaco population that no longer exists. Finally, we find evidence that interbreeding practices were widespread during the domestication process by the early camelid herders in the Atacama during the Early Formative period and predating the Spanish conquest.
Human cytomegalovirus antagonizes activation of Fcγ receptors by distinct and synergizing modes of IgG manipulation
Authors: Kolb Philipp , Hoffmann Katja , Sievert Annika , Reinhard Henrike , Merce-Maldonado Eva , Le-Trilling Vu Thuy Khanh , Halenius Anne , Gütle Dominique , Hengel Hartmut
Published: March 2021

Human cytomegalovirus (HCMV) is endowed with multiple highly sophisticated immune evasion strategies. This includes the evasion from antibody mediated immune control by counteracting host Fc-gamma receptor (FcγR) mediated immune control mechanisms such as antibody-dependent cellular cytotoxicity (ADCC). We have previously shown that HCMV avoids FcγR activation by concomitant expression of the viral Fc-gamma-binding glycoproteins (vFcγRs) gp34 and gp68. We now show that gp34 and gp68 bind IgG simultaneously at topologically different Fcγ sites and achieve efficient antagonization of host FcγR activation by distinct but synergizing mechanisms. While gp34 enhances immune complex internalization, gp68 acts as inhibitor of host FcγR binding to immune complexes. In doing so, gp68 induces Fcγ accessibility to gp34 and simultaneously limits host FcγR recognition. The synergy of gp34 and gp68 is compelled by the interfering influence of excessive non-immune IgG ligands and highlights conformational changes within the IgG globular chains critical for antibody effector function.
Stretch-activated ion channels identified in the touch-sensitive structures of carnivorous Droseraceae plants
Authors: Procko Carl , Murthy Swetha , Keenan William T , Mousavi Seyed Ali Reza , Dabi Tsegaye , Coombs Adam , Procko Erik , Baird Lisa , Patapoutian Ardem , Chory Joanne
Published: March 2021

In response to touch, some carnivorous plants such as the Venus flytrap have evolved spectacular movements to capture animals for nutrient acquisition. However, the molecules that confer this sensitivity remain unknown. We used comparative transcriptomics to show that expression of three genes encoding homologs of the MscS-Like (MSL) and OSCA/TMEM63 family of mechanosensitive ion channels are localized to touch-sensitive trigger hairs of Venus flytrap. We focus here on the candidate with the most enriched expression in trigger hairs, the MSL homolog FLYCATCHER1 (FLYC1). We show that FLYC1 transcripts are localized to mechanosensory cells within the trigger hair, transfecting FLYC1 induces chloride-permeable stretch-activated currents in naïve cells, and transcripts coding for FLYC1 homologs are expressed in touch-sensing cells of Cape sundew, a related carnivorous plant of the Droseraceae family. Our data suggest that the mechanism of prey recognition in carnivorous Droseraceae evolved by co-opting ancestral mechanosensitive ion channels to sense touch.
ISOTOPIA TEXTUAL E O MEIO PUBLICITÁRIO: OS CAMINHOS PARA A GERAÇÃO DE SENTIDO
Authors: Alves Farias Alcione , Costa Mouzinho Andréia , Melo das Neves Brenda , Diego Carmin Lavareda Welton
Published: March 2021

Tomando como base a perspectiva da Semiótica Discursiva, fundada por Algirdas Julien Greimas, o presente trabalho tem como objetivo analisar as estratégias textuais isotópicas utilizadas em um comercial da Rede Americana de Fast Food Burger King como artifício para o alcance de um determinado público-alvo. Sob esse prisma teórico, faz-se necessário um diálogo metodológico baseado em Barros (2005), Fiorin (1999) e Henn (2006), dentre outros autores que discorrem sobre as temáticas concernentes a esse campo de estudo. Uma peça publicitária produzida pela Burger King comporá o corpus e será tomada como objeto de significação e cultural, de interação entre os sujeitos, evidenciando possíveis relações ideológicas entre interlocutores.
O MINIMALISMO COMO ALTERNATIVA À SOCIEDADE DE CONSUMO
Authors: Morgana Boos de Quadros Cynthia , Duwe Camila , Durieux Zucco Fabricia , Foletto Fiuza Thamires
Published: March 2021

Este artigo apresenta os resultados de estudo sobre motivações que levam pessoas a buscarem um estilo de vida e de consumo minimalista, destacando as visões delas sobre a influência da publicidade e da mídia nas decisões de consumo. Por meio de pesquisa netnográfica foram analisados comentários e postagens de um grupo privado no Facebook, de onde foram coletados e categorizados os principais motivos explicitados pelos participantes. Além disso, foram identificadas características de personalidade que os consumidores minimalistas revelaram em relação ao papel da publicidade e da mídia. Foi possível perceber que essas pessoas buscam por esse estilo de vida por meio de mudanças de comportamento e de tomada de consciência como forma de crescimento pessoal em vários aspectos da vida.
Recombinant Protein rP21 from Trypanosoma cruzi has Effect on Inflammation, Angiogenesis and Fibrogenesis in Skin Wound Model C57BL/6 Mouse
Authors: Barbosa Jeranice Silva , Moura Francyelle Borges Rosa de , Ferreira Bruno Antonio , Martins Flávia Alves , Muniz Elusca Helena , Gomide José Augusto Leoncio , Silva Cláudio Vieira da , Ribeiro Daniele Lisboa , Araújo Fernanda de Assis , Tomiosso Tatiana Carla
Published: March 2021

Aims: Recombinant proteins rP2 has demonstrated biological activity in inflammation by acting on the recruitment of leukocytes and by inducing phagocytosis, also modulating the processes of angiogenesis and fibrogenesis in different experimental models. In this study we evaluated the effects of the recombinant protein rP21 from Trypanosama cruzi in cutaneous wounds.

Study Design: The wounds were induced on the back of mice and treated with rP21 at 1 µg/mL and 50 µg/mL concentration, for 3 and 7 days.

Study Location and Duration: Institute of Biomedical Sciences and Animal Breeding Network and Rodents of the Federal University of Uberlândia, between February 2015 and February 2016.

Methodology: The contraction time of wound, inflammatory cell activities (neutrophils and macrophages), angiogenesis and local collagen density were evaluated.

Sample: Wound induction was performed on 64 male BALB / c mice approximately 9 weeks old.

Results: Wounds treated with rP21 showed less closure time, in addition to exhibiting greater neutrophil activity in the initial phasis, which was reduced simultaneously with the increased macrophage activity. The rP21 also performed pro-angiogenic and pro-fibrogenic activity in this study model.

Conclusion: These results demonstrate for the first time the biological potential of rP21 in accelerating skin tissue repair.
Foreign Direct Investment and the Effect on a Developing Economy
Authors: Ozuzu Sydney , Isukul Araniyar
Published: March 2021

This study examined the effect of foreign direct investment on a developing economy. The study employed multiple regression models to estimate the relationship that exists between sectorial inflow of foreign direct investment and Nigeria economic growth. Augmented Dickey Fuller Test, Johansen Co-integration test, normalized co-integrating equations, parsimonious vector error correction model and pair-wise causality tests were used to conduct the investigations and analysis. The findings of the result reveal that foreign direct investment in the agricultural sector have positive but no significant effect, foreign direct investment in the manufacturing sector have positive and significant effect, foreign direct investment in the mining and querying sector have negative but no significant effect, foreign direct investment in the transport and communication sector have positive and  significant effect while  foreign direct investment in the oil and gas sector have positive and significant effect on Nigeria real gross domestic products. The study concludes that the oil and gas sector have the greatest impact on Nigeria economic growth followed by manufacturing, agricultural, transport and communication sectors while mining and quarrying reduces gross domestic product. Nigerian policy makers should design sectoral policy reforms with the intention of creating an enabling business environment, improve infrastructure, address issues of insecurity in the north and south that hinder foreign direct investment in mining and quarrying sectors. Furthermore, there is the need to strengthen policy cohesion with regards to foreign direct investments to ensure that mining and quarrying sectors perform as well as the oil and gas sector.
Standardized Achievement Testing, Aptitude Testing, and Attitude Testing: How Similar or Different are these Concepts in Educational Assessment?
Authors: Nugba Regina Mawusi , Quansah Frank
Published: March 2021

Testing is an inevitable issue in educational and psychological measurement and assessment. Over the years, several tests and testing mechanisms have been developed to assess different latent traits of learners or examinees. Of these testing forms, standardized achievement, aptitude and attitude testing have taken the forefronts in education, psychology, and research. Whereas these concepts are distinct, they, however, play similar roles which have been misconceived by many, especially those without expertise in educational assessment and measurement. The aim of this paper is to compare standardized achievement testing, aptitude testing, and attitude testing, using a narrative literature review approach. The paper provides a synthesis of gathered information that delineates conditions necessary for the utilization of each testing approach.
Influence of Functional Groups on the Photophysical Properties of 1-(4-Methylsulfonyl Phenyl)-3-(4-n, n Dimethyl (amino Phenyl)-2-Propen-1-One Chalcone as Laser Dye
Authors: Attia M. F. , Elbadawi Abdelrahman A. , Ibnaouf K. H. , Elzupir A. O.
Published: March 2021

In this work, 1-(4-methylsulfonyl phenyl)-3-(4-N, N dimethyl amino phenyl)-2-propen-1-one (MSPPP) chalcone was synthesized and examined as optical materials. The absorption and fluorescence characteristics of MSPPP chalcone were recorded in ten different solvents. The influence of functional groups (FG) and solvents on their photophysical properties were investigated. These include absorption, fluorescence, stokes shift, and amplified spontaneous emission (ASE). The absorption spectra of MSPPP showed a wavelength band in the range 404 - 427 nm, whereas the fluorescence spectra exhibited a band at 473 - 533 nm. The FGs and solvents had an adorable effect on the optical properties of the synthesized materials. ASE was observed under pump pulse laser excitation, and the wavelengths were attuned from 511 to 548 nm.
Urinary Tract Infection in Omani Children: Etiology and Antimicrobial Resistance. A Comparison between First Episode and Recurrent Infection
Authors: El-Naggari Mohamed , Al-Mulaabed Sharef , Rabah Fatma , Idrees Ahmed B. , Muharrmi Zakaria Al , Nour Ibtisam El
Published: March 2021

Aims: The aims of this study were identification of the causative organisms, uropathogens’ resistance, and extended-spectrum β-lactamase producing bacteria in primary and recurrent urinary tract infection.

Study Design: A retrospective study included Omani children, less than 14 years, with any documented urinary tract infection.

Place and Duration of Study: Sultan Qaboos University Hospital between September 2008 and August 2012.

Methodology: Comparison was made between both groups using Chi-squared (χ2) test as appropriate.

Results: The first group included 175 children with first attack of urinary tract infection. Escherichia coli was the leading pathogen (69%), Klebsiella pneumonia (17%; P<0.001), and extended-spectrum β-lactamase producing bacteria (3%). 230 isolated uropathogens from 74 patients with recurrent urinary tract infection. The most common isolated pathogen was Escherichia coli 187 (81.3%; P<0.001), followed by Klebsiella pneumonia 12 (5.1%), and extended-spectrum β-lactamase producing bacteria (7%; P=0.042). Overall resistance to parenteral antibiotics was less evident than oral antibiotics, with least resistance to Meropenem and Imipenem (1% each). Higher resistance was found in recurrent urinary tract infection to Augmentin, Cefuroxime, Ceftriaxone, and Cefotaxime. Oral Nitrofurantoin showed least resistance in first and recurrent urinary tract infection, but increased in non- Escherichia coli uropathogens.

Conclusion: Escherichia coli and ESBL were more common in recurrent urinary tract infection, while Klebsiella pneumonia were found more in first urinary tract infection. Meropenem, Imipenem, Amikacin, and Piperacillin/Tazobactam can be used cautiously and selectively, while Cefotaxime and Ceftriaxone cannot be used in both groups. Our report shows high resistance rates to Ampicillin, Cefuroxime, and Amoxicillin/Clavulanate. First-generation cephalosporin is not recommended for use as empiric therapy. We recommend the use of Ciprofloxacin and Nitrofurantoin as empiric treatment in both groups, with close monitoring of clinical response. Indeed, a larger scale multicenter national and regional studies are recommended in Oman and gulf region.
Pharmacy and Medicine Students' Self-assessment of Their Knowledge about Rare Diseases
Authors: Ahmed Nehad J. , Alrawili Abdulrahman S. , Alkhawaja Faisal Z.
Published: March 2021

Aim: The aim of this study was to describe the knowledge of pharmacy and medicine students about rare diseases.

Methodology: This is a cross sectional study that was conducted in January 2021. The study included a questionnaire that was adapted from a previous study. The questionnaire was translated to Arabic and after validation it was converted to online form to be filled by the students.

Results: Most of the students were pharmacy students (60.78%) and the majority of them were females (72.55%).  Only 11.76% of the students reported that their knowledge is very good about rare diseases. About 52.94% of them said that they are prepared for caring for patients with rare diseases. The majority of the students agreed that they need to broad their knowledge about rare diseases (97.06%). More than half of the students said that they get knowledge about rare disease from internet (51.96%) and scientific literature and research (48.04%).

Conclusion: The present study showed poor knowledge of pharmacy and medicine students about rare diseases. There is an urgent need to raise the awareness of medical students on rare diseases and educate them about these diseases by adding a course on rare diseases in their medical curricula.
Evaluation of the Phytochemical Constituents of Extracts of Kigelia africana Fruit and Sorghum bicolor, Stalk in Lagos Nigeria
Authors: Obianagha Nkem F. , Okafor Chukwuma J. , Chukwuani Ufuoma , Ogundahunsi Omobolanle Abioye , Ogbonnia Steve O. , Obeagu Emmanuel Ifeanyi , Haji Hassan Thabit , Said Othman Hakum
Published: March 2021

The use of herbal medicines and phytonutrients or nutraceuticals with numerous secondary metabolites continues to expand rapidly across the world, with many people now resorting to these products to treat various health challenges in different national healthcare settings. Therefore, the study is aimed at evaluating the phytochemical composition in the fruit extract of Kigelia africana and Sorghum bicolor stalks bought from the Mushin market in Lagos, Nigeria to ascertain its numerous pharmacological activities and identify the various chemical compounds responsible for these activities. Ethanol extracts of identified fresh fruits of K. africana  and S. bicolor stalks (L) were prepared for phytochemical screening using established methods for Alkaloids, Tannins, Phenols, Flavonoids, and Terpenoids testing as well as Gas Chromatography-Mass Spectrometry Analysis (GC-MS) for the analysis of the extracts. The chemical constituents present in both extracts were tannins, phenols, flavonoids, and saponins as well as alkaloids found only in K. africana. Also, the chromatogram of K. africana revealed the presence of forty-four (44) phytochemical constituents. At the same time, that of S. bicolor were twenty-nine (29) phytochemical constituents that could contribute to the medicinal quality of the plant with 9, 12-Octadeadienoic acid (Z, Z), and 13-Docosenoic acid, methyl ester, (Z) found as the major compounds respectively. The K africana and S. bicolor African indigenous plants in Lagos, Nigeria, possess different phytocomponents of scientific importance, biological action, and potential medicinal properties. There is a need for more standardization and purification of this herbal formulation for the treatment of diseases.
Nanomechanical Characterization of the Deformation Response of Orthotropic Ti–6Al–4V
Authors: Rojas-Ulloa Carlos , Bouffioux Chantal , Jaramillo Andrés F. , García-Herrera Claudio M. , Hussain Tanvir , Duchêne Laurent , Riu Guiomar , Josep Roa Joan , Flores Paulo , Marie Habraken Anne , Tuninetti Víctor
Published: March 2021

The nanoindentation‐induced mechanical deformation response is applied to identify the orthotropic elastic moduli using the Delafargue and Ulm method as well as to validate the asymmetric orthotropic CPB06 nonlinear plasticity model required in simulations of nonuniform macroscopic mechanical response of the Ti–6Al–4V alloy. Scanning electron microscope (SEM) technique allows to select the maximum penetration depth for the indentation in the deformed alpha phase and alpha–beta interphase,αandα/β, respectively. The apparent macromechanical response can be successfully derived from several residual imprints conducted at micro‐ and/or submicrometric length scale and distributed throughout samples of the investigated bulk alloy, as demonstrated by correlation with finite element simulations based on the orthotropic elastoplastic model. The accurate numerical response obtained validates the material model and the Delafargue and Ulm approach, opening a window for next generation identification methods of macromechanical plasticity models with hybrid experimental–numerical method based on instrumented indentation and the use of SEM technique.
Effects of Mo Single‐Layer Thickness on Microstructure and Tribological Behavior of WSx/Mo/a‐C/Mo Multilayer Films
Authors: Zheng Xiao-Hua , Wang Tao , Wang Gong-Qi , Zhang Wan-Kun , Yang Fang-Er
Published: March 2021

WS2/a‐C multilayer films exhibit good friction reduction but relatively low hardness and load‐bearing capacity. To further enhance the tribological properties of WS2/a‐C films, Mo layers with different thicknesses are introduced into WSx/a‐C multilayer films to fabricate WSx/Mo/a‐C/Mo multilayer films by magnetron sputtering. The microstructure and tribological properties of the films are characterized by X‐ray diffractometry, scanning electron microscopy, nanoindentation, and ball‐on‐disk tribotesting. The results show that the WSx/Mo/a‐C/Mo multilayer films have better mechanical and tribological properties than WSx/a‐C multilayer films. With increasing Mo single‐layer thickness, the hardness of the multilayer films initially increases and then decreases slightly; moreover, an increased elastic modulus and decreased adhesion are observed. The multilayer film with an Mo single‐layer thickness of 2 nm demonstrates the optimal set of comprehensive properties (i.e., a maximum hardness (H)/elastic modulus (E) ratio of 0.0793, H3/E2 ratio of 0.0812 GPa, binding force of 30.4 N, minimum friction coefficient of 0.187, and wear rate of 1.01 × 10−14 m3 N−1 m−1).
Performance and Stability of Magnetorheological Fluids—A Detailed Review of the State of the Art
Authors: Thiagarajan Sandhiya , Koh Amanda S.
Published: March 2021

Magnetorheological fluids (MRFs) are functional materials, prepared by dispersing magnetic particles in a nonmagnetic carrier fluid, that exhibit a change in mechanical properties (e.g., increase in viscosity and yield stress) when subjected to a magnetic field. Change in mechanical properties is demonstrated by a fast (i.e., fraction of milliseconds) and reversible transition from a liquid‐ to a solid‐like state. This transition, due to a structural reorganization of magnetic particles in the carrier fluid, makes MRFs a valuable material for damping, breaking systems, medical and prosthetics, and robotics. Since the discovery of MRFs in 1948, developing MRF preparation methods that result in improved performance and the storage without oxidation and settling is paramount. This article presents a review on recent developments in the preparation process of MRFs with a special emphasis on the state of the art in additives and coatings used in enhancing MRF chemical, colloidal, and thermal stability. Recent advances in MRF materials and formulations that have increased yield stress and magnetic properties are discussed. Finally, this review analyses the present‐day challenges in MRF research and makes suggestions for the field to improve MRF stability and performance drawing on previous MRF work and work outside of the fields.
An Ion‐Pairing Approach to Stereoselective Metal‐Free Ring‐Opening Metathesis Polymerization
Authors: Yang Xuejin , Gitter Sean R. , Roessler Allison G. , Zimmerman Paul M. , Boydston Andrew J.
Published: March 2021

Stereochemistry can have a profound impact on polymer and materials properties. Unfortunately, straightforward methods for realizing high levels of stereocontrolled polymerizations are often challenging to achieve. In a departure from traditional metal‐mediated ring‐opening metathesis polymerization (ROMP), we discovered a remarkably simple method for controlling alkene stereochemistry in photoredox mediated metal‐free ROMP. Ion‐pairing, initiator sterics, and solvation effects each had profound impact on the stereochemistry of polynorbornene (PNB). Simple modifications to the reaction conditions produced PNB with trans alkene content of 25 to >98 %. High cis content was obtained from relatively larger counterions, toluene as solvent, low temperatures (−78 °C), and initiators with low Charton values. Conversely, smaller counterions, dichloromethane as solvent, and enol ethers with higher Charton values enabled production of PNB with high trans content. Data from a combined experimental and computational investigation are consistent with the stereocontrolling step of the radical cationic mechanism proceeding under thermodynamic control.
A Colorimetric Method for Quantifying Cis and Trans Alkenes Using an Indicator Displacement Assay
Authors: Valenzuela Stephanie A. , Crory Hannah S. N. , Yao Chao‐Yi , Howard James R. , Saucedo Gabriel , de Silva A. Prasanna , Anslyn Eric V.
Published: March 2021

A colorimetric indicator displacement assay (IDA) amenable to high‐throughput experimentation was developed to determine the percentage of cis and trans alkenes. Using 96‐well plates two steps are performed: a reaction plate for dihydroxylation of the alkenes followed by an IDA screening plate consisting of an indicator and a boronic acid. The dihydroxylation generates either erythro or threo vicinal diols from cis or trans alkenes, depending upon their syn‐ or anti‐addition mechanisms. Threo diols preferentially associate with the boronic acid due to the creation of more stable boronate esters, thus displacing the indicator to a greater extent. The generality of the protocol was demonstrated using seven sets of cis and trans alkenes. Blind mixtures of cis and trans alkenes were made, resulting in an average error of ±2 % in the percentage of cis or trans alkenes, and implementing E2 and Wittig reactions gave errors of ±3 %. Furthermore, we developed variants of the IDA for which the color may be tuned to optimize the response for the human eye.
Chemical Imaging of Hierarchical Porosity Formation within a Zeolite Crystal Visualized by Small‐Angle X‐Ray Scattering and In‐Situ Fluorescence Microscopy
Authors: Filez Matthias , Vesely Martin , Garcia‐Torregrosa Ivan , Gambino Marianna , Attila Özgün , Meirer Florian , Katrukha Eugene A. , Roeffaers Maarten B. J. , Garrevoet Jan , Kapitein Lukas C. , Weckhuysen Bert M.
Published: March 2021

Introducing hierarchical porosity to zeolites is vital for providing molecular access to microporous domains. Yet, the dynamics of meso‐ and macropore formation has remained elusive and pore space ill‐characterized by a lack of (in situ) microscopic tools sensitive to nanoporosity. Here, we probe hierarchical porosity formation within a zeolite ZSM‐5 crystal in real‐time by in situ fluorescence microscopy during desilication. In addition, we introduce small‐angle X‐ray scattering microscopy as novel characterization tool to map intracrystal meso‐ and macropore properties. It is shown that hierarchical porosity formation initiates at the crystal surface and propagates to the crystal core via a pore front with decreasing rate. Also, hierarchical porosity only establishes in specific (segments of) subunits which constitute ZSM‐5. Such space‐dependent meso‐ and macroporosity implies local discrepancies in diffusion, performance and deactivation behaviors even within a zeolite crystal.
Sequence‐Selective Protection of Peptides from Proteolysis
Authors: Li Xiaowei , Chen Kaiqian , Zhao Yan
Published: March 2021

Proteolysis of proteins and peptides is involved in the infection of cells by enveloped viruses and also in the invasion and spread of cancer cells. Shutting down broad‐specificity proteases, however, is problematic because normal functions by these proteases will be affected. Herein, nanoparticle receptors were prepared from molecular imprinting for complex biological peptides. Their strong and selective binding enabled them to protect their targeted sequences from proteolysis in aqueous solution at stoichiometric amounts. Generality of the method was demonstrated by the protection of hydrophobic and hydrophilic peptides from different proteases, selective protection of a segment of a long peptide, and selective protection of a targeted peptide in a mixture. Most interestingly, two receptors targeting different parts of a long peptide could work in cooperation to protect the overall sequence, highlighting the versatility of the method.
Reversed Active Sites Boost the Intrinsic Activity of Graphene‐like Cobalt Selenide for Hydrogen Evolution
Authors: Shen Shijie , Lin Zhiping , Song Kai , Wang Zongpeng , Huang Liangai , Yan Linghui , Meng Fanqi , Zhang Qinghua , Gu Lin , Zhong Wenwu
Published: March 2021

Optimizing the hydrogen adsorption Gibbs free energy (ΔGH) of active sites is essential to improve the overpotential of the electrocatalytic hydrogen evolution reaction (HER). We doped graphene‐like Co0.85Se with sulfur and found that the active sites are reversed (from cationic Co sites to anionic S sites), which contributed to an enhancement in electrocatalytic HER performance. The optimal S‐doped Co0.85Se composite has an overpotential of 108 mV (at 10 mA cm−2) and a Tafel slope of 59 mV dec−1, which exceeds other reported Co0.85Se‐based electrocatalysts. The doped S sites have much higher activity than the Co sites, with a hydrogen adsorption Gibbs free energy (ΔGH) close to zero (0.067 eV), which reduces the reaction barrier for hydrogen production. This work provides inspiration for optimizing the intrinsic HER activity of other related transition metal chalcogenides.
In‐Situ Intermolecular Interaction in Composite Polymer Electrolyte for Ultralong Life Quasi‐Solid‐State Lithium Metal Batteries
Authors: He Kangqiang , Cheng Samson Ho‐Sum , Hu Jieying , Zhang Yangqian , Yang Huiwen , Liu Yingying , Liao Wenchao , Chen Dazhu , Liao Chengzhu , Cheng Xin , Lu Zhouguang , He Jun , Tang Jiaoning , Li Robert K. Y. , Liu Chen
Published: March 2021

Solid‐state lithium metal batteries built with composite polymer electrolytes using cubic garnets as active fillers are particularly attractive owing to their high energy density, easy manufacturing and inherent safety. However, the uncontrollable formation of intractable contaminant on garnet surface usually aggravates poor interfacial contact with polymer matrix and deteriorates Li+ pathways. Here we report a rational designed intermolecular interaction in composite electrolytes that utilizing contaminants as reaction initiator to generate Li+ conducting ether oligomers, which further emerge as molecular cross‐linkers between inorganic fillers and polymer matrix, creating dense and homogeneous interfacial Li+ immigration channels in the composite electrolytes. The delicate design results in a remarkable ionic conductivity of 1.43×10−3 S cm−1 and an unprecedented 1000 cycles with 90 % capacity retention at room temperature is achieved for the assembled solid‐state batteries.
Access to Functionalized Pyrenes, Peropyrenes, Terropyrenes, and Quarterropyrenes via Reductive Aromatization
Authors: Werner Simon , Vollgraff Tobias , Sundermeyer Jörg
Published: March 2021

Herein we report a versatile concept for the synthesis of fourfold functionalized, soluble pyrenes, peropyrenes, terropyrenes, and quarterropyrenes. They were obtained by a modular stepwise approach towards the rylene scaffold via Suzuki–Miyaura cross coupling, oxidative cyclodehydrogenation in the presence of caesium hydroxide under air, and finally zinc‐mediated reductive silylation. The silylated reaction products were characterized by X‐ray crystallography. The first example of a synthesized and crystallized quarterropyrene is presented and its oxidation reaction investigated. The functionalized ropyrenes were systematically characterized by means of UV/Vis–NIR and photoluminescence spectroscopy showing a bathochromic shift of 80 nm per naphthalene unit and a nearly linear increase of the extinction coefficients. Cyclic voltammograms and DFT calculations identify them as electron‐rich dyes and show a narrowing of the electrochemically determined HOMO–LUMO gap and lower oxidation potentials for the higher homologues.