bluuebunny/crossref_metadata_2025_split huggingface dataset:
L’évaluation approfondie des difficultés d’apprentissage des mathématiques
Authors: Lafay Anne , Helloin Marie Christel 
Published: July 2020

Les troubles de la cognition mathématique (touchant 1 à 10 % d’enfants) recouvrent un large spectre de difficultés et représentent un handicap majeur pour l’intégration scolaire, sociale et professionnelle. Le modèle de la réponse à l’intervention est axé sur la prévention des difficultés d’apprentissage et sur la différenciation des interventions auprès des élèves. Une composante de cette approche est l’évaluation approfondie des habiletés mathématiques. L’objectif de cet article est de présenter une démarche d’évaluation approfondie des habiletés mathématiques d’un enfant permettant d’établir un portrait de forces et faiblesses dans le but de guider l’intervention. Sont proposées : 1) une courte synthèse critique des outils d’évaluation mathématiques à la disposition des professionnels et de leurs qualités psychométriques; 2) une démarche d’évaluation approfondie des habiletés mathématiques et cognitives; et 3) une étude de cas.
Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oils of Four Species of the Lamiaceae Family
Authors: Paulus Dalva , Luchesi Luana Aline , Busso Cleverson , Frata Marcela Tostes , Oliveira Paula Juliane Barbosa de 
Published: July 2020

Aims: The biological properties of essential oils represent possible therapeutic alternatives, with antimicrobial and antioxidant activities, and application in many areas of the industry. The objective was to determine the yield, chemical composition, antibacterial and antioxidant activities of the essential oils of Lavandula angustifolia, Pogostemon cablin, Rosmarinus officinalis, and Thymus vulgaris against Staphylococcus aureus, Salmonella enteritidis, Escherichia coli and Pseudomonas aeruginosa.
Place and Duration of Study: The experiment was conducted at the microbiology laboratory of the Federal University of Technology - Paraná, Brazil, in the period between June 2016 to May 2017.
Methodology: The essential oils were analyzed by gas chromatography coupled to mass spectrometry. The antibacterial activity was determined by microdilution in broth, showing minimum inhibitory concentration and minimum bactericidal concentration. The antioxidant activity was evaluated by scavenging of 2,2-diphenyl-1-picryl hydrazyl radical (DPPH).
Results: The average yields of essential oils from L. angustifolia, P. cablin, R. officinalis,and T. vulgaris were (%) 0.85; 2.0; 1.20, and 1.19, respectively. The major components of lavender essential oil were linalyl acetate (40.1%) and linalool (35.2%); for P. cablin - patchoulol (31.5%), seichelene (13.6%) and α-bulnesene (15.6%); for rosemary - camphor (32.5%), 1.8-cineole (13.6%) and α-pinene (9.8); for T. vulgaris - thymol (47%), o-scimene (21.6%), and carvacrol (11.4%). Thyme oil showed the best results for antibacterial activity, and low values (0.195 µL mL-1) of minimum inhibitory concentration were needed to inhibit S. aureus and S. enteritidis, and for L. angustifolia, P. cablin, and R. officinalis higher concentrations of essential oil were required. The essential oils of P. cablin and T. vulgaris had the strongest antioxidant properties (12.08 and 10.2 µmol trolox mL−1).
Conclusion: The essential oils evaluated have an inhibitory effect on the microorganisms under study and also interesting antioxidant activity, which could be used by medicine to control bacterial infections, with potential application as natural food preservatives and as nutraceuticals.
An Evaluation of Hand Hygiene Practice by Health Care Personnel at a Tertiary Hospital in North Eastern Nigeria
Authors: Imoudu I. A. , Zirami M. G. , Zamo A. B. , Idiodemise I. E. , Mahmood L. M. , Sambo H. , Abdul I. U. 
Published: July 2020

Background: Hand hygiene when done satisfactorily is one of the most effective ways of preventing hospital acquired infections. However elementary the process may seem, it is one that has been shown to significantly elude health care personnel (HCP). This study aimed at assessing the knowledge, attitude and practice of hand hygiene by HCP at the Federal Medical Centre (FMC) Azare, North-Eastern Nigeria.
Methods: The study was a cross sectional survey of HCP who make direct contact with patients at four randomly selected units of FMC Azare. Using the purposive sampling technique, a structured questionnaire was administered on the respondents. The collected data was analyzed using the statistical package for social sciences (SPSS) version 20.0. Presentation of data was done with tables, in proportions and percentages.
Results: Eighty-two (82) HCP were recruited into the study, 64 (78.0%) were males and 18 (22.0%) were females, giving a ratio of 3.6:1. Nurses made up 43.9%, health assistants 34.1% and doctors 22.0% of the total number. The respondents exhibited a good knowledge of hand hygiene (93.2%). Seventy- seven (93.9%) of the respondents showed a positive attitude while 6.1% had a negative attitude towards hand hygiene. All categories of respondents had good practice scores regarding hand hygiene.
Conclusion: The knowledge, attitude and practice of hand hygiene of HCP at FMC Azare is optimal. However, continuous training on infection prevention and control with emphasis on hand hygiene and other strategies is recommended to allow for improvement in compliance to the concept of standard precautions.
Stem Cell Modelling in COVID-19
Authors: Nagpal Rajeev , Srivastava Akriti , Ekuta Victor 
Published: July 2020

The ability of stem cells to differentiate into any desired cell type can make them an indispensable tool in COVID-19 modelling studies. Stem cells derived from patients with preexisting conditions or derived from vulnerable populations such as children, can also assist scientists in understanding the unique contributions of these diverse factors to variations in COVID-19 infection responses. Innovative approaches are urgently needed to adequately address the global impact of COVID-19. Stem cell based strategies offer such an approach.
Enhanced Long-term Stability and Carbon Resistance of Ni/MnxOy-Al2O3 Catalyst in Near-equilibrium CO2 Reforming of Methane for Syngas Production
Authors: Djebarri Baya , Touahra Fouzia , Aider Nadia , Bali Ferroudja , Sehailia Moussa , Chebout Redouane , Bachari Khaldoun , Halliche Djamila 
Published: July 2020

Herein we study the catalytic activity/stability of a new generation of cheap and readily available Ni and Al-based catalysts using two Mn precursors, namely Mn(NO3)2 and Mn(EDTA)2- complex in the reaction of CO2 reforming of methane. In this respect, Ni/Al2O3 and two types of Ni/MnxOy-Al2O3 catalysts were successfully synthesized and characterized using various analytical techniques: TGA, ICP, XRD, BET, FTIR, TPR-H2, SEM-EDX, TEM, XPS and TPO-O2. Utilization of Mn(EDTA)2- as synthetic precursor successfully furnished Ni/Al2O3-MnxOyY (Y = EDTA) catalyst which was more active during CO2 reforming of methane when compared to Ni/MnxOy-Al2O3 catalyst, synthesized using Mn(NO3)2 precursor. Compared to Ni/MnxOy-Al2O3, Ni/Al2O3-MnxOyY catalyst afforded near-equilibrium conversion values at 700 °C (ca. 95% conversion for CH4 and CO2, and H2/CO = 0.99 over 50 h reaction time). Also, Ni/Al2O3-MnxOyY showed more resistance to carbon formation and sintering; interestingly, after 50 h reaction time, the size of Ni0 particles in Ni/MnxOy-Al2O3 almost doubled while that of Ni/Al2O3-MnxOyY remained unchanged. The elevated conversion of CO2 and CH4 in conjunction with the observed low carbon deposition on the surface of our best catalyst (Ni/Al2O3-MnxOyY) indicated the presence of MnxOy oxide positioning mediated simultaneous in-situ carbon elimination with subsequent generation of oxygen vacant sites on the surface for more CO2 adsorption. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).Corrigendum to this article is here: https://doi.org/10.9767/bcrec.15.3.9855.907-907
Teaching Children with Autism Reading Comprehension Skills using Online Reading Instruction: Preliminary Evaluation of Headsprout Reading Comprehension®
Authors: Grindle Corinna , Kurzeja Olivia , Tyler Emily , Saville Maria , Hughes J. Carl , Hastings Richard P. , Brown Freddy Jackson 
Published: July 2020

AbstractChildren with autism often exhibit difficulties with reading comprehension. Recent studies have demonstrated positive outcomes for typical learners from the internet-based reading comprehension program, Headsprout Reading Comprehension®. In the present study, a preliminary evaluation of HRC was conducted with six children with autism. The primary aim was to investigate whether it would be feasible to use HRC with children with autism and whether any adaptations to the standard teaching procedure and extra support would be needed. A secondary aim was to investigate the potential of HRC to improve reading comprehension skills. The study used a multiple case series design with six children. Results are discussed with reference to increased reading comprehension ability in the six children and the practical strategies required to support children with autism so that they may benefit from the program.
Swedish Final Year Early Childhood Preservice Teachers' Attitudes, Concerns and Intentions towards Inclusion
Authors: Uusimaki Liisa , Garvis Susanne , Sharma Umesh 
Published: July 2020

Abstract
This article explores ninety-seven (n=97) Swedish Early Childhood (EC) preservice teachers' attitudes, concerns, and intentions to include children with disabilities in regular classrooms. A six-part self-reporting questionnaire was used to examine participants' attitudes, concerns, efficacy, and intentions toward inclusion. The results showed that although the Swedish EC preservice teachers' in this study expressed 'some' concern about working with children the results indicated a high degree of teacher efficacy. To determine predictors of participants' intentions and use of inclusive practices a series of regression analysis were undertaken. Knowledge of local legislation emerged as significant predictor of participants' intention scores. Teaching efficacy scores were significant predictors for both intention and use of inclusive practices. The results are discussed in the context of the Swedish idea ‘a school for all' with a focus on the Swedish preschool teacher education program.
Prevalence and associated occupational factors of low back pain among the bank employees in Dhaka City
Authors: Ali Mohammad , Ahsan Gias U , Hossain Ahmed 
Published: July 2020

Abstract

Objective
Low back pain (LBP) is one of the common health problems among full-time office employees that causes absenteeism from work. The aim of the study is to identify the association between occupational factors and LBP among full-time bank employees in Dhaka City.

Materials and Methods
We conducted a cross-sectional study involving 593 full-time bank employees who were engaged in sedentary works. The 1-month complaint of LBP was measured using a subscale of subjective health complaints inventory. Multivariable logistic models were performed to identify variables related to LBP, and a random forest technique was performed to determine the top five important variables.

Results
The 1-month prevalence for LBP was found to be 36.6% among the bank employees, and the prevalence was the highest (64.3%) for the 51- to 59-year-old age group. The regression analysis indicates that respondents from both agegroups, 41-50 years (OR = 2.00, 95% confidence interval [CI] = 1.10-3.69) and 51-59 years age groups (OR = 5.14, 95% CI = 2.05-13.64), are significantly associated with LBP. Furthermore, obesity (OR = 2.06, 95% CI = 1.01-4.21), and prolong working hours (&gt;9 hours) (OR = 1.42, 95% CI = 1.01-2.0) are positively associated with LBP. The top five important variables for LBP identified by random forest technique are: age, length of employment, prolong office hours, presence of chronic illness, and physical activity.

Conclusion
LBP is highly prevalent in full-time bank employees. The occupational factors, including the length of employment (&gt;10 years) and long working hours, play a significant role in developing LBP among bank employees. Moreover, several factors, including age, chronic illness, obesity, and physical activity, should be taken into account in the prevention of LBP in bank employees.
Optical Forces: From Fundamental to Biological Applications
Authors: Xin Hongbao , Li Yuchao , Liu Yong‐Chun , Zhang Yao , Xiao Yun‐Feng , Li Baojun 
Published: July 2020

AbstractOptical forces, generally arising from changes of field gradients or linear momentum carried by photons, form the basis for optical trapping and manipulation. Advances in optical forces help to reveal the nature of light–matter interactions, giving answers to a wide range of questions and solving problems across various disciplines, and are still yielding new insights in many exciting sciences, particularly in the fields of biological technology, material applications, and quantum sciences. This review focuses on recent advances in optical forces, ranging from fundamentals to applications for biological exploration. First, the basics of different types of optical forces with new light–matter interaction mechanisms and near‐field techniques for optical force generation beyond the diffraction limit with nanometer accuracy are described. Optical forces for biological applications from in vitro to in vivo are then reviewed. Applications from individual manipulation to multiple assembly into functional biophotonic probes and soft‐matter superstructures are discussed. At the end future directions for application of optical forces for biological exploration are provided.
Toward Robust Macroscale Superlubricity on Engineering Steel Substrate
Authors: Li Panpan , Ju Pengfei , Ji Li , Li Hongxuan , Liu Xiaohong , Chen Lei , Zhou Huidi , Chen Jianmin 
Published: July 2020

Abstract“Structural superlubricity” is an important fundamental phenomenon in modern tribology that is expected to greatly diminish friction in mechanical engineering, but now is limited to achieve only at nanoscale and microscale in experiment. A novel principle for broadening the structural superlubricating state based on numberless micro‐contact into macroscale superlubricity is demonstrated. The topography of micro‐asperities on engineering steel substrates is elaborately constructed to divide the macroscale surface contact into microscale point contacts. Then at each contact point, special measures such as pre‐running‐in period and coating heterogeneous covalent/ionic or ionic/ionic nanocomposite of 2D materials are devised to manipulate the interfacial ordered layer‐by‐layer state, weak chemical interaction, and incommensurate configuration, thereby satisfying the prerequisites responsible for structural superlubricity. Finally, the robust superlubricating states on engineering steel–steel macroscale contact pairs are achieved with significantly reduced friction coefficient in 10−3 magnitude, extra‐long antiwear life (more than 1.0 × 106 laps), and good universality to wide range of materials and loads, which can be of significance for the industrialization of “structural superlubricity.”
Flexible Large‐Area Light‐Emitting Devices Based on WS2 Monolayers
Authors: Andrzejewski Dominik , Oliver Ruth , Beckmann Yannick , Grundmann Annika , Heuken Michael , Kalisch Holger , Vescan Andrei , Kümmell Tilmar , Bacher Gerd 
Published: July 2020

AbstractStrong covalent in‐plane bonds and a tiny thickness in the nanometer range make two‐dimensional (2D) materials ideally suited for flexible electronic or optoelectronic applications. Despite this exciting perspective, only a few prototypes of such flexible devices—photodetectors and transistors—have been reported until now. The first large‐area flexible light‐emitting device (LED) based on 2D materials is realized by integrating a transition metal dichalcogenide (TMDC) monolayer synthesized by metal organic chemical vapor deposition (MOCVD) into a p–n architecture on conductive polymer foil. This flexible LED demonstrates homogeneous red light emission from a few square millimeter area in a scalable design. Uniquely, the electroluminescence can be tuned over 30 meV simply by bending the devices, i.e., by applying a defined strain. This approach combines the flexibility of organic semiconductor device concepts with the durability of inorganic semiconductor technology.
Novel Organic Semiconductors Based on 1,5‐Naphthyridine‐2,6‐Dione Unit for Blue‐Selective Organic Phototransistor
Authors: Kim Jin Hong , Choi Min‐Woo , Kim Su‐Yeon , Jung Seyoung , Choi Yeong Suk , Park Soo Young 
Published: July 2020

AbstractNovel bis‐lactam based narrowband blue light absorbing organic p‐type semiconducting molecules including 3,7‐di(naphthalen‐1‐yl)‐1,5‐dioctyl‐1,5‐naphthyridine‐2,6‐dione (C8‐NTDN1) are synthesized and their phototransistor properties are investigated. Based on the excellent optical (absorption peak at 446 nm with full width at half‐maximum value of 70.7 nm) and electrical properties (field effect hole mobility of up to 0.38 cm2 V−1 s−1), C8‐NTDN1 phototransistor shows decent photoresponsivity of up to 3.6 × 102 A W−1, which can be further improved to 2.1 × 103 A W−1 by overlaying discontinuous C60 layer on top of C8‐NTDN1 thin‐film.
Aliovalent Doping and Surface Grafting Enable Efficient and Stable Lead‐Free Blue‐Emitting Perovskite Derivative
Authors: Xiong Guangting , Yuan Lifang , Jin Yahong , Wu Haoyi , Li Zhenzhang , Qu Bingyan , Ju Guifang , Chen Li , Yang Shihe , Hu Yihua 
Published: July 2020

AbstractLead halide perovskites have emerged as superstar semiconductors owing to their superior optoelectronic properties. However, the issues of chemical and thermodynamic instability and toxicity are yet to be resolved. Here, the non‐ and Bi3+‐doped all‐inorganic lead‐free perovskite derivatives are reported. Most remarkable is the successful extending of excitation of Cs2ZrCl6 to match with the commercial near ultraviolet light‐emitting diode chips via deliberate Bi3+ aliovalent doping. The blue emission, contrary to self‐trapped exciton (STE) emissions amply reported previously, originates from Bi3+ ionoluminescence with a high photoluminescence quantum efficiency of 50%. The competition for harvesting electrons between STEs and Bi3+ is studied in detail by steady‐ and transient‐state fluorescence spectroscopy in combination with theoretical calculations. Surface grafting endows Cs2ZrCl6:Bi3+ with a robust water‐resistant core–shell‐like structure and abiding emission. Surprisingly, the emission intensity even increases to 115.94% of the initial level after immersing in water for 2 h. The as‐obtained phosphor enables the fabrication of a white light‐emitting diode (w‐LED), achieving CCT = 4179 K and Ra = 81.9. This work not only promotes the step toward development of lead‐free, stable, and high‐efficiency perovskite derivatives for the next‐generation warm w‐LEDs, but also reveals the structure–PL relationship.
Thermally Activated Delayed Phosphorescence and Interchromophore Exciton Coupling in a Platinum‐Based Organometallic Emitter
Authors: Mak Chun Hong , Liu Rugeng , Han Xu , Tang Yunqi , Zou Xingli , Shen Hsin‐Hui , Meng Yao , Zou Guizheng , Hsu Hsien‐Yi 
Published: July 2020

AbstractThe comprehension of triplet exciton mechanisms in organic–inorganic semiconductors has a significant impact on emerging optoelectronic and biosensing technologies. The capability to mutually integrate the photophysical properties of conjugated organic semiconductor with those of well‐characterized heavy metals is therefore of utmost importance. Due to heavy‐atom effect, the platinum‐based triplet emitter, PPtTPtT, achieves highly efficient phosphorescence. Here, it is first demonstrated that π‐conjugated PPtTPtT organometallics in electrochemiluminescence (ECL) devices exhibit precisely dual and blueshifted phosphorescence simultaneously induced by thermally activated delayed phosphorescence (TADP) and interchromophore exciton interaction in H‐aggregates. Utilizing a combination of photophysical and electrochemical techniques, the distinctive ECL process involving energy sufficient singlet route (S‐route), intersystem crossing, as well as triplet relaxation, hereafter called SIT‐route, is reported for the first time. The hybrid TADP materials designed with donor–acceptor–donor system enable potential applications, including but not limited to organic light‐emitting diodes, light‐emitting electrochemical cells, imaging devices, and other bio‐related detections.
Recent Advances in the Synthesis of Imidazolines (2009–2020)
Authors: Mehedi Md Shafaat Al , Tepe Jetze J. 
Published: July 2020

AbstractImidazoline is an important class of compounds found in numerous natural and pharmaceutical products. The compounds are also used as an intermediate in the synthesis of organic molecules. Moreover, chiral imidazolines are widely utilized as organocatalysts to synthesize various natural and synthetic organic compounds. In the past decade, there was an increase in interest in developing new methods to synthesize these imidazoline analogs. Both modification of the previously established methods and the development of new methods are carried out significantly. This review article highlights the progress of the synthesis of imidazoline scaffolds in the last few years (2009‐present). The review also described the proposed mechanism illustrated in many of the reports.magnified image
Asymmetric Nazarov Cyclizations of Unactivated Dienones by Hydrogen‐Bond‐Donor/Lewis Acid Co–Catalyzed, Enantioselective Proton‐Transfer
Authors: Metternich Jan B. , Reiterer Martin , Jacobsen Eric N. 
Published: July 2020

AbstractWe report an enantioselective Nazarov cyclization catalyzed by chiral hydrogen‐bond‐donors in concert with silyl Lewis acids. The developed transformation provides access to tri‐substituted cyclopentenones in high levels of enantioselectivity (up to 95% e.e.) from a variety of simple unactivated dienones. Kinetic and mechanistic studies are consistent with a reversible 4π‐electrocyclization C−C bond‐forming step followed by rate‐ and enantio‐determining proton‐transfer as the mode of catalysis.magnified image
Polyisocyanide Hydrogels as a Tunable Platform for Mammary Gland Organoid Formation
Authors: Zhang Ying , Tang Chunling , Span Paul N. , Rowan Alan E. , Aalders Tilly W. , Schalken Jack A. , Adema Gosse J. , Kouwer Paul H. J. , Zegers Mirjam M. P. , Ansems Marleen 
Published: July 2020

AbstractIn the last decade, organoid technology has developed as a primary research tool in basic biological and clinical research. The reliance on poorly defined animal‐derived extracellular matrix, however, severely limits its application in regenerative and translational medicine. Here, a well‐defined, synthetic biomimetic matrix based on polyisocyanide (PIC) hydrogels that support efficient and reproducible formation of mammary gland organoids (MGOs) in vitro is presented. Only decorated with the adhesive peptide RGD for cell binding, PIC hydrogels allow MGO formation from mammary fragments or from purified single mammary epithelial cells. The cystic organoids maintain their capacity to branch for over two months, which is a fundamental and complex feature during mammary gland development. It is found that small variations in the 3D matrix give rise to large changes in the MGO: the ratio of the main cell types in the MGO is controlled by the cell–gel interactions via the cell binding peptide density, whereas gel stiffness controls colony formation efficiency, which is indicative of the progenitor density. Simple hydrogel modifications will allow for future introduction and customization of new biophysical and biochemical parameters, making the PIC platform an ideal matrix for in depth studies into organ development and for application in disease models.