bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pedagogy in Speaking: Challenges Addressed by Teacher-Student in the ESL Context
Authors: Ahmed Md. Kawser 
Published: April 2018

Teaching speaking is perhaps one of the major challenges for teachers teaching in English as a Second Language (ESL) classroom environment. Like writing, speaking is not linear and easy approach to ensure the best utilization among learners. Since speaking is a real life event and face to face conversation, it needs more sophisticated care, practice oriented session for the students and effective means to implement it in the ESL situation. Even language experts often grope to outline effective and mediocre way to help learners have a good understanding in speaking. This paper attempts to delineate the focal points where teachers and students face problems in teaching and learning speaking. It immensely chalks out with methodological study, qualitative data analysis and the underlining factors ESL teachers face enormously in the pedagogy of speaking for second language learners. My paper will outline the pedagogical tenets of speaking in the realistic non-native set ups and diagnose the impediments faced by learners when they are supposed to speak and by teachers when they teach speaking for their students.
Determinants of Unmet Mental Healthcare Needs of Single Adults Who Are Homeless or Vulnerably Housed
Authors: Duhoux Arnaud , Aubry Tim , Ecker John , Cherner Rebecca , Agha Ayda , To Matthew J. , Hwang Stephen W. , Palepu Anita 
Published: April 2018

Persons who are homeless experience higher levels of mental illness, unmet mental healthcare needs, and physical healthcare needs than the general population. This study aimed (1) to determine the reasons contributing to having unmet mental healthcare needs (UMHCN) and (2) to examine the determinants of UMHCN among a representative sample of adults who are homeless or vulnerably housed in three Canadian cities (N=1190). Almost a quarter (23.3%) of the sample reported UMHCN in the past year. The reported reasons for having UMHCN pertained especially to the availability (31.5%), accommodation (22.1%), and acceptability (21.3%) of services. Age, city, and need-for-care variables were associated with UMHCN in multivariate analysis. Implications of the findings for policy and program planning are discussed.Les personnes sans-abri présentent des niveaux plus élevés de maladie mentale, de besoins de soins de santé et de besoins non comblés de soins de santé mentale que la population générale. Cette étude visait (1) à déterminer les raisons des besoins non comblés des soins de santé mentale (BNCSM) et (2) à examiner les déterminants des BNCSM auprès d›un échantillon représentatif d›adultes sans-abri ou logés de façon précaire dans trois villes canadiennes (N = 1190). Près d›un quart (23,3%) de l›échantillon a rapporté des BNCSM lors de l›année passée. Les raisons principales des BNCSM portaient sur la disponibilité (31,5%), l’accommodement (22,1%), et l›acceptabilité (21,3%) des services. L’âge, la ville et les besoins de soins étaient les variables associées aux BNCSM en analyse multivariée. Les implications des résultats pour la planification des services et le développement des politiques sont discutées.
Improved dose homogeneity using electronic compensation technique for total body irradiation
Authors: Tyson Tara E. , Podgorsak Matthew B. , Singh Anurag K. , Wang Iris Z. 
Published: April 2018

AbstractIn total body irradiation (TBI) utilizing large parallel‐opposed fields, the manual placement of lead compensators has conventionally been used to compensate for the varying thickness throughout the body. The goal of this study is to pursue utilizing the modern electronic compensation (E‐comp) technique to more accurately deliver dose to TBI patients. Bilateral parallel‐opposed TBI treatment plans were created using E‐comp for 15 patients for whom CT data had been previously acquired. A desirable fluence pattern was manually painted within each field to yield a uniform dose distribution. The conventional compensation technique was simulated within the treatment planning system (TPS) using a field‐in‐field (FIF) method. This allows for a meaningful evaluation of the E‐comp technique in comparison to the conventional method. Dose–volume histograms (DVH) were computed for all treatment plans. The mean total body dose using E‐comp deviates from the prescribed dose (4 Gy) by an average of 2.4%. The mean total body dose using the conventional compensation deviates from the prescribed dose by an average of 4.5%. In all cases, the mean body dose calculated using E‐comp technique deviates less than 10% from that of conventional compensation. The average reduction in maximum dose using E‐comp compared to that of the conventional method was 30.3% ± 6.6% (standard deviation). In all cases, the s‐index for the E‐comp technique was lower (10.5% ± 0.7%) than that of the conventional method (15.8% ± 4.4%), indicating a more homogenous dose distribution. In conclusion, a large reduction in maximum body dose can be seen using the proposed E‐comp technique while still producing a mean body dose that accurately complies with the prescription dose. Dose homogeneity was quantified using s‐index which demonstrated a reduction in hotspots with E‐comp technique. Electronic compensation technique is capable of more accurately delivering a total body dose compared to conventional methods.
Cognitive and functional connectivity alterations in Friedreich's ataxia
Authors: Cocozza Sirio , Costabile Teresa , Tedeschi Enrico , Abate Filomena , Russo Camilla , Liguori Agnese , Del Vecchio Walter , Paciello Francesca , Quarantelli Mario , Filla Alessandro , Brunetti Arturo , Saccà Francesco 
Published: April 2018

AbstractObjectiveThe aim of this study was to perform the first resting‐state functional MRI (RS‐fMRI) analysis in Friedreich's ataxia (FRDA) patients to assess possible brain functional connectivity (FC) differences in these patients, and test their correlations with neuropsychological performances.MethodsIn total, 24 FRDA patients (M/F: 15/9, mean age 31.3 ± 15.0) and 24 healthy controls (HC; M/F: 15/9, mean age 30.7 ± 15.5) were enrolled in this cross‐sectional study. All patients underwent a thorough neuropsychological battery, investigating different cognitive domains. RS‐fMRI data were analyzed using a seed‐based approach, probing the FC of cortical areas potentially referable to specific executive and cognitive functions compromised in FRDA.ResultsCompared to HC, FRDA patients showed overall worse neuropsychological scores in several domains, including global cognitive assessment, spatial memory, visuoperception and visuospatial functions, and executive functions. Analysis of RS‐fMRI data showed a higher FC in FRDA patients compared to HC between paracingulate gyri and the medial frontal gryrus, between the superior frontal gyrus and bilateral angular gyri, and between the middle temporal gyrus and the cingulate gyrus, with a reduced FC between the medial frontal gryrus and the cerebellum.InterpretationWe found a reduction in FC between frontal areas and the contralateral cerebellar cortex in FRDA, in line with the known alteration in cerebello‐cortical pathway in this condition. On the other hand, a higher FC between different cortical areas was shown, possibly reflecting a compensatory phenomenon. These results, in conjunction with clinical findings, may shed new light on the pattern of supratentorial and infratentorial involvement, and on dynamics of brain plasticity in this disease.
Atomic Scale Modulation of Self‐Rectifying Resistive Switching by Interfacial Defects
Authors: Wu Xing , Yu Kaihao , Cha Dongkyu , Bosman Michel , Raghavan Nagarajan , Zhang Xixiang , Li Kun , Liu Qi , Sun Litao , Pey Kinleong 
Published: April 2018

AbstractHigher memory density and faster computational performance of resistive switching cells require reliable array‐accessible architecture. However, selecting a designated cell within a crossbar array without interference from sneak path currents through neighboring cells is a general problem. Here, a highly doped n++ Si as the bottom electrode with Ni‐electrode/HfOx/SiO2 asymmetric self‐rectifying resistive switching device is fabricated. The interfacial defects in the HfOx/SiO2 junction and n++ Si substrate result in the reproducible rectifying behavior. In situ transmission electron microscopy is used to quantitatively study the properties of the morphology, chemistry, and dynamic nucleation–dissolution evolution of the chains of defects at the atomic scale. The spatial and temporal correlation between the concentration of oxygen vacancies and Ni‐rich conductive filament modifies the resistive switching effect. This study has important implications at the array‐level performance of high density resistive switching memories.
Highly Sensitive Field‐Effect Ammonia/Amine Sensors with Low Driving Voltage Based on Low Bandgap Polymers
Authors: Wang Zhijie , Liu Zitong , Chen Liangliang , Yang Yang , Ma Jing , Zhang Xisha , Guo Yunlong , Zhang Guanxin , Zhang Deqing 
Published: April 2018

AbstractAmmonia/amine gas sensors have received increasing attention in recent years, due to their applications in monitoring of meat and seafood spoilage and air pollution as well as diagnosis of chronic diseases. Herein, a new conjugated polymer PTTEH is developed, which is composed of thieno[3,4‐b]thiophene units, with very low bandgap. The low bandgap and the existence of radical state endow the polymer thin film with good electrical conductivity. As a result, PTTEH is successfully utilized for construction of a field‐effect transistor (FET) sensor for ammonia and amines at low driving voltages, which are advantageous for practical applications. Moreover, this FET sensor shows good selectivity and high sensitivity (down to 10 ppb) toward ammonia and amines. Accordingly, the real‐time monitoring of meat spoilage is achieved with this FET sensor. These studies will open a new venue to fabricate sensitive, portable, and small size sensors for real‐time monitoring of chemical vapors.
Solution‐Processable Conjugated Polymers as Anode Interfacial Layer Materials for Organic Solar Cells
Authors: Xu Bowei , Hou Jianhui 
Published: April 2018

AbstractIn recent years, solution‐processed conjugated polymers have been extensively used as anode interfacial layer (AIL) materials in organic solar cells (OSCs) due to their excellent film‐forming property and low‐temperature processing advantages. In this review, the authors focus on the recent advances in conjugated polymers as AIL materials in OSCs. Several of the main classes of solution‐processable conjugated polymers, including poly(3,4‐ethylenedioxythiophene):(styrenesulfonate), polyaniline, polythiophene, conjugated polyelectrolytes, sulfonated poly(diphenylamine), and crosslinked polymers as AIL materials are discussed in depth, and the mechanisms of these AIL materials in enhancing OSC performances are also elucidated. The structure–property relationships of various conjugated polymer AIL materials are analyzed, and some important design rules for such materials toward high efficiencies and stable OSCs are presented. In addition, some chemical and physical approaches to optimize the photoelectronic and physic properties of conjugated polymer AIL materials, which improve their performance in modifying OSCs, are also highlighted. Considering the significance of tandem OSCs, the relevant applications of conjugated polymer AIL materials in constructing interconnection layers for tandem OSCs are also mentioned. Finally, a brief summary is presented and some perspectives to help researchers understand the current challenges and opportunities in this area are proposed.
Metallic Twin Boundaries Boost the Hydrogen Evolution Reaction on the Basal Plane of Molybdenum Selenotellurides
Authors: Kosmala Tomasz , Coy Diaz Horacio , Komsa Hannu‐Pekka , Ma Yujing , Krasheninnikov Arkady V. , Batzill Matthias , Agnoli Stefano 
Published: April 2018

AbstractThe hydrogen evolution reaction (HER) is a fundamental process that impacts several important clean energy technologies. Great efforts have been taken to identify alternative materials that could replace Pt for this reaction or that may present additional functional properties such as optical activity and advanced electronic properties. Herein, a comparative study of the HER activity for ultrathin films of MoTe2, MoSe2, and their solid solutions on highly oriented pyrolytic graphite is reported. Combining advanced characterization techniques and density functional theory calculations with electrochemical measurements, it is shown that the chemical activity of the scarcely reactive 2H phases can be boosted by the presence of metallic twin boundaries. These defects, which are thermodynamically stable and naturally present in Mo‐enriched MoTe2 and MoSe2, endow the basal plane of the 2H phase with a high chemical activity, which is comparable to the metastable 1T polymorph.
Highly Tunable Heterojunctions from Multimetallic Sulfide Nanoparticles and Silver Nanowires
Authors: Liu Dongliang , Liu Yong , Huang Peng , Zhu Cheng , Kang Zhenhui , Shu Jie , Chen Muzi , Zhu Xing , Guo Jun , Zhuge Lanjian , Bu Xianhui , Feng Pingyun , Wu Tao 
Published: April 2018

AbstractA facile and general strategy is presented to create well‐defined heterojunctions with ultra‐small multimetallic sulfide nanoparticles (MMSNPs) uniformly coated on sliver nanowires. A unique aspect of this method is the atomic‐level pre‐integration of multimetallic components by exploiting recently developed supertetrahedral metal sulfide nanoclusters. The use of such nanoclusters also enables the convenient formation of the ultrathin interfacial Ag2S layer via etching. The heterojunctions (denoted as MMSNPs/Ag2S/Ag‐NWs) benefit from adjustable multimetallic components and display tunable visible‐light‐driven photocatalytic performance owing to the synergistic effect of multimetallic components from MMSNPs and the high carrier mobility of Ag‐NWs. The synthetic strategy opens new routes to designing and fabricating various heterojunctions with multimetallic components, which could further expand their applications in catalysis, electronics, and photonics.
Free‐Standing Air Cathodes Based on 3D Hierarchically Porous Carbon Membranes: Kinetic Overpotential of Continuous Macropores in Li‐O2 Batteries
Authors: Xu Shu‐Mao , Liang Xiao , Ren Zhi‐Chu , Wang Kai‐Xue , Chen Jie‐Sheng 
Published: April 2018

AbstractFree‐standing macroporous air electrodes with enhanced interfacial contact, rapid mass transport, and tailored deposition space for large amounts of Li2O2 are essential for improving the rate performance of Li‐O2 batteries. An ordered mesoporous carbon membrane with continuous macroporous channels was prepared by inversely topological transformation from ZnO nanorod array. Utilized as a free‐standing air cathode for Li‐O2 battery, the hierarchically porous carbon membrane shows superior rate performance. However, the increased cross‐sectional area of the continuous macropores on the cathode surface leads to a kinetic overpotential with large voltage hysteresis and linear voltage variation against Butler–Volmer behavior. The kinetics were investigated based on the rate‐determining step of second electron transfer accompanied by migration of Li+ in solid or quasi‐solid intermediates. These discoveries shed light on the design of the air cathode for Li‐O2 batteries with high‐rate performance.
Frustrierte Helizität: Zusammenführung divergierender Enden einer stabilen aromatischen Amid‐Helix zu einem fluxionalen Makrocyclus
Authors: Urushibara Ko , Ferrand Yann , Liu Zhiwei , Masu Hyuma , Pophristic Vojislava , Tanatani Aya , Huc Ivan 
Published: April 2018

AbstractDie Makrocyclisierung eines stabilen zweiwindigen helikalen aromatischen Pentamids – eine Struktur mit zwei divergierenden Enden, die nicht anfällig für einen Ringschluss sind – wurde durch die transiente Einführung von Helizitätsstörern in Form von säurelabilen tertiären Dimethoxybenzylamiden möglich gemacht. Nach dem Entfernen der Helizitätsstörern zeigen NMR‐Spektroskopie, Kristallstrukturanalyse und theoretische Studien, dass die Makrocyclen eine gespannte Struktur besitzen, die sie dazu veranlasst, einen möglichst hohen Grad an Helizität anzustreben, obwohl es sich immer noch um eine cyclische Struktur handelt. Zwei mögliche Punkte für eine solche Störung in ihrer Helizität sind insbesondere cis‐amidische Bindungen. Auf fluxionale Art und Weise können sich diese Störungen in der Helix entlang des Makrocyclus in definierten Bahnen ausbreiten, und somit zehn degenerierte Konformationen erzeugen.
Optically Matched Semiconductor Quantum Dots Improve Photophosphorylation Performed by Chloroplasts
Authors: Xu Youqian , Fei Jinbo , Li Guangle , Yuan Tingting , Xu Xia , Wang Chenlei , Li Junbai 
Published: April 2018

AbstractA natural–artificial hybrid system was constructed to enhance photophosphorylation. The system comprises chloroplasts modified with optically matched quantum dots (chloroplast–QD) with a large Stokes shift. The QDs possess a unique optical property and transform ultraviolet light into available and highly effective red light for use by chloroplasts. This favorable feature enables photosystem II contained within the hybrid system to split more water and produce more protons than chloroplasts would otherwise do on their own. Consequently, a larger proton gradient is generated and photophosphorylation is improved. At optimal efficiency activity increased by up to 2.3 times compared to pristine chloroplasts. Importantly, the degree of overlap between emission of the QDs and absorption of chloroplasts exerts a strong influence on the photophosphorylation efficiency. The chloroplast–QD hybrid presents an efficient solar energy conversion route, which involves a rational combination of a natural system and an artificial light‐harvesting nanomaterial.
Graphene‐like Molecules with Four Zigzag Edges
Authors: Gu Yanwei , Wu Xiaojin , Gopalakrishna Tullimilli Y. , Phan Hoa , Wu Jishan 
Published: April 2018

AbstractAn efficient synthetic method toward graphene‐like molecules (GLMs), having four zigzag edges, is described. They were obtained as stable materials and their structures were confirmed by X‐ray crystallographic analysis. They exhibit topology‐ and size‐dependent electronic properties and global aromaticity, which are all different from GLMs having either all‐armchair edges, or three zigzag edges, or two armchair/two zigzag edges. They can be reversibly oxidized and reduced into stable charged species, which show fragmental aromatic character to minimize anti‐aromaticity. Our studies give some new insights into the electronic structures and properties of a new type of rarely studied GLMs.
Tunable Multicolor Phosphorescence of Crystalline Polymeric Complex Salts with Metallophilic Backbones
Authors: Liu Qi , Xie Mo , Chang Xiaoyong , Cao Shuang , Zou Chao , Fu Wen‐Fu , Che Chi‐Ming , Chen Yong , Lu Wei 
Published: April 2018

AbstractA total of 35 [Au(NHC)2][MX2] (NHC=N‐heterocyclic carbene; M=Au or Cu; X=halide, cyanide or arylacetylide) complex salts were synthesized by co‐precipitation of [Au(NHC)2]+ cations and [MX2]− anions. These salts contain crystallographically determined polymeric Au⋅⋅⋅Au or Au⋅⋅⋅Cu interactions and are highly phosphorescent with quantum yields up to unity and emission color tunable in the entire visible regions. The nature of the emissive excited states is generally assigned to ligand (anion)‐to‐ligand (cation) charge‐transfer transitions assisted by d10⋅⋅⋅d10 metallophilicity. The emission properties can be further tuned by controlled triple‐component co‐crystallization or by epitaxial growth. Correct recipes for white light‐emitting phosphors with quantum yields higher than 70 % have been achieved by screening the combinatorial pool.
Frustrated Helicity: Joining the Diverging Ends of a Stable Aromatic Amide Helix to Form a Fluxional Macrocycle
Authors: Urushibara Ko , Ferrand Yann , Liu Zhiwei , Masu Hyuma , Pophristic Vojislava , Tanatani Aya , Huc Ivan 
Published: April 2018

AbstractMacrocyclization of a stable two‐turn helical aromatic pentamide, that is, an object with diverging ends that are not prone to cyclization, was made possible by the transient introduction of disruptors of helicity in the form of acid‐labile dimethoxybenzyl tertiary amide substituents. After removal of the helicity disruptors, NMR, X‐ray crystallography, and computational studies show that the macrocycle possesses a strained structure that tries to gain as high a helical content as possible despite being cyclic. Two points of disruption of helicity remain, in particular a cis amide bond. This point of disruption of helicity can propagate along the cycle in a fluxional manner according to defined trajectories to produce ten degenerate conformations.
Iron‐Catalyzed Reaction of γ‐Tocopherol with Methyl Linoleate Hydroperoxides in Solutions
Authors: Yamauchi Ryo , Kinoshita Tomomi , Iwamoto Satoshi 
Published: April 2018

Abstractγ‐Tocopherol is one of the main constituents in vegetable oils and acts as an antioxidant by trapping lipid‐peroxyl radicals. This study reports reaction products of γ‐tocopherol with lipid‐peroxyl radicals formed by iron‐catalyzed decomposition of methyl linoleate hydroperoxides (MeLOOH) in toluene and methanol solutions. The products in toluene solution were tocored, methyl (8a‐dioxy‐γ‐tocopherone)‐epoxyoctadecenoates (γT‐OO‐epoxyMeL), methyl (8a‐dioxy‐γ‐tocopherone)‐octadecadienoates (γT‐OO‐MeL), γ‐tocopherol biphenyl dimer (γTBD), γ‐tocopherol diphenylether dimer (γTED), and adducts of γ‐tocopherol dimers with the MeLOOH‐derived peroxyl radicals (γTED‐OO‐epoxyMeL, γTBD‐OO‐MeL, and γTED‐OO‐MeL). The iron‐catalyzed reaction in toluene proceeded slowly, whereas the reaction in methanol was relatively fast. The reaction products in methanol were γT‐OO‐epoxyMeL and γTED‐OO‐epoxyMeL together with tocored, γTBD, and γTED. The results indicate that the iron‐catalyzed decomposition of MeLOOH in toluene produces both epoxyperoxyl and peroxyl radicals and that the decomposition in methanol yields only the epoxyperoxyl radicals. These peroxyl radicals could react with the 8a‐carbon‐centered radical of γ‐tocopherol or its dimers.
Effect of Moisture and Heat Treatment of Corn Germ on Oil Quality
Authors: Zheng Liyou , Ji Congli , Jin Jun , Xie Dan , Liu Ruijie , Wang Xingguo , Jin Qingzhe , Huang Jianhua 
Published: April 2018

AbstractThe changes in the quality of crude corn oil caused by moisture and two different thermal pretreatments (oven heating and steam heating) of wet‐milled corn germ were evaluated and compared with those of untreated oil. Increasing the moisture content of the corn germ from 8 to 25% before oil extraction increased the acid value (AV) (3.02–4.01 mg KOH g−1), peroxide value (PV) (0.52–1.05 meq kg−1), and the red value (7.3–8.7) and decreased the content of total tocopherols by 37% and that of γ‐tocopherols by 31%. Oven heating tended to decrease the AV and PV while steam heating significantly increased the total and individual tocopherol contents (P < 0.05). The different moisture contents and thermal pretreatments of corn germ caused no significant differences in the fatty acid composition and the contents of total and individual phytosterols of the crude oils. The γ‐tocopherol contents were found to be highly correlated with the red values (the corresponding R2 reached 0.9977 and 0.9089 for moisture and heat pretreatments, respectively).