bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessment of Oral Health Knowledge, Attitude and Practice for Public Primary School Teachers in the City of Madinah, Saudi Arabia
Authors: Ali Al-Johani Wejdan , Elanbya May Gamar 
Published: April 2019

Background: School teachers can play an important role in helping to instill good health habits in their students. Consequently, teachers need to have an adequate knowledge and a proper attitude regarding oral health.
Method and Materials: This is a cross sectional study conducted among public primary school teachers in Al-Madinah city. A questionnaire was distributed in 10 randomly selected schools. All teachers were asked to participate. Data was analyzed using SPSS software.
Results: 200 teachers were asked to participate all of them responded. 81% of the teachers were aware that caries are caused by bacteria in the oral cavity. 69.5% of teachers thinks that fluorides strength teeth. 44.5 % of the teachers brushed their teeth twice a day. Only 15% of the teachers regularly discuss oral health topics with their students. 74.5% of them think that it is necessary to treat tooth caries in primary teeth. 70.5% think that dental health education should be included in the primary school curriculum. 64% of them believed that schools should restrict the consumption of caries causing snacks during school hours.
Conclusion: Teachers’ knowledge regarding oral health needs improvement. Their own oral health practices are fair; however, their attitude towards oral health is very positive.
Controlling Students’ Disciplinary Problems in Universities
Authors: Oboegbulem Angie Ijeoma , Onyejiuwa Okagu 
Published: April 2019

The study examined the management strategies for controlling students’ disciplinary problems in the universities south east geopolitical zone of Nigeria. Descriptive survey design was used for the study. The population of the study comprises of about 5037 administrators and student union executives; the sample of study was 1712 (980 males and 732 females) made up of 1,536 university administrators and student union executives in the ten public (five federal and five state-owned) universities in South East Geopolitical Zone. Five percent of 3,501 lecturers were selected using proportionate random sampling technique. Structured questionnaire, oral interview and focus group discussion guide were developed and used for data collection after validation by two experts in educational administration and educational evaluation. The instruments were trial-tested for reliability using Cronbach Alpha reliability coefficient to a random sample of 30 university administrators outside the study area. The overall internal consistency yielded 0.97.
Four research questions and one hypothesis guided the study. Mean and standard deviation were used to answer the four research questions, while oral interview and focus group discussion guide were analyzed qualitatively; t- test statistic was used to test the null hypothesis at 0.05 level of probability. There were no significant differences in the mean ratings of males and females, experienced and less experienced and institutional ownership on university administrators on the management strategies for controlling students’ disciplinary problems in universities. The result also revealed that there are students’ disciplinary problems that constrain the acts of teaching and learning in universities and management strategies like Administrative strategies, which include banning of the sale of alcohol and drugs in the school premises; Security strategies which include searching and ceasing all dangerous weapons from students from time to time; Education/Enlightenment strategies, which will create forum for university administrators and students dialogue in Universities in South East Nigeria.
A study on the relationship between usage and composition form of work‐unit type in schools of Sweden
Authors: Kakino Yoshinori , Hatsumi Manabu 
Published: April 2019

AbstractThis paper presents a study on work‐unit types of advanced schools in Sweden. The results of this study are as follows. (1) A work‐unit is composed of 11 kinds of rooms and 2 kinds of partitions, clearly separated from the whole of a school building by partitions such as doors. As there are not many furniture in common spaces, a work‐unit can be located as the most important space for learning. (2) Several cases have “architectural outside spaces” related to units and entrances; this refers to a new external space on the site, filled with natural environment. In the other words, a school building is located as an element that invents an external space with the feature. (3) “Architectural outside spaces” are planned with many “attractors,” for example, benches, equipments, and play ground. (4) Common spaces are more important for higher grade students than lower grade students. However, outside environment is useful and important for lower grade students.
In Operando Probing of Lithium‐Ion Storage on Single‐Layer Graphene
Authors: Ni Kun , Wang Xiangyang , Tao Zhuchen , Yang Jing , Shu Na , Ye Jianglin , Pan Fei , Xie Jian , Tan Ziqi , Sun Xuemei , Liu Jie , Qi Zhikai , Chen Yanxia , Wu Xiaojun , Zhu Yanwu 
Published: April 2019

AbstractDespite high‐surface area carbons, e.g., graphene‐based materials, being investigated as anodes for lithium (Li)‐ion batteries, the fundamental mechanism of Li‐ion storage on such carbons is insufficiently understood. In this work, the evolution of the electrode/electrolyte interface is probed on a single‐layer graphene (SLG) film by performing Raman spectroscopy and Fourier transform infrared spectroscopy when the SLG film is electrochemically cycled as the anode in a half cell. The utilization of SLG eliminates the inevitable intercalation of Li ions in graphite or few‐layer graphene, which may have complicated the discussion in previous work. Combining the in situ studies with ex situ observations and ab initio simulations, the formation of solid electrolyte interphase and the structural evolution of SLG are discussed when the SLG is biased in an electrolyte. This study provides new insights into the understanding of Li‐ion storage on SLG and suggests how high‐surface‐area carbons could play proper roles in anodes for Li‐ion batteries.
Scalable Polymer Nanocomposites with Record High‐Temperature Capacitive Performance Enabled by Rationally Designed Nanostructured Inorganic Fillers
Authors: Li He , Ai Ding , Ren Lulu , Yao Bin , Han Zhubing , Shen Zhonghui , Wang Jianjun , Chen Long‐Qing , Wang Qing 
Published: April 2019

AbstractNext‐generation microelectronics and electrical power systems call for high‐energy‐density dielectric polymeric materials that can operate efficiently under elevated temperatures. However, the currently available polymer dielectrics are limited to relatively low working temperatures. Here, the solution‐processable polymer nanocomposites consisting of readily prepared Al2O3 fillers with systematically varied morphologies including nanoparticles, nanowires, and nanoplates are reported. The field‐dependent electrical conduction of the polymer nanocomposites at elevated temperatures is investigated. A strong dependence of the conduction behavior and breakdown strength of the polymer composites on the filler morphology is revealed experimentally and is further rationalized via computations. The polymer composites containing Al2O3 nanoplates display a record capacitive performance, e.g., a discharged energy density of 3.31 J cm−3 and a charge–discharge efficiency of >90% measured at 450 MV m−1 and 150 °C, significantly outperforming the state‐of‐the‐art dielectric polymers and nanocomposites that are typically prepared via tedious, low‐yield approaches.
Scalable Processing Ultrathin Polymer Dielectric Films with a Generic Solution Based Approach for Wearable Soft Electronics
Authors: Chen Sujie , Peng Sai , Sun Wenjian , Gu Guoying , Zhang Qing , Guo Xiaojun 
Published: April 2019

AbstractWearable intelligence on human body requires light and soft electronics built on ultrathin supporting films. It would be ideal to have a generic and scalable approach for processing such ultrathin electronics based on various materials to accommodate different design requirements. In this work, a solution based delamination approach is developed using sodium hydroxide (NaOH) treated cross‐linked polymethylmethacrylate (c‐PMMA) film as the separation layer to process ultrathin polymer films. The c‐PMMA layer has resistance to various solvents for coating different polymer materials on top. Reaction of the c‐PMMA surface with mixture of NaOH and water reduces adhesion between the polymer film and the carrier substrate. The polymer film is thus able to be delaminated with facile processes. The approach is applied to fabricate ultrathin flexible or stretchable transparent conductive films, and resistive strain sensors using different polymer materials. A new wrinkle structure capacitive pressure sensor is also realized by integrating different ultrathin polymer films, and presents higher or comparable sensitivity (2.76 kPa−1) compared to previous work but with a much lighter weight (<60 g m−2). Wearable systems using these sensors are finally built for real time measuring wrist pulse waves, and controlling all actions of a shooting computer game with only three fingers.
Epitaxial Liftoff of Wafer‐Scale VO2 Nanomembranes for Flexible, Ultrasensitive Tactile Sensors
Authors: Li Xingxing , Yin Zhigang , Zhang Xingwang , Wang Ye , Wang Denggui , Gao Menglei , Meng Junhua , Wu Jinliang , You Jingbi 
Published: April 2019

AbstractHighly sensitive tactile sensors with long‐term stability and low power consumption are one of the key components for flexible electronics. Here, for the first time, the fabrication of VO2 nanomembrane tactile sensors by epitaxial liftoff from ZnO sacrificial layer is reported. The wafer‐scale nanomembranes inherit the structural and electrical properties of the as‐grown films, and the wet transfer generates negligible influence on the quality of VO2. Most importantly, giant electrical responses to external strains are found due to the release of substrate clamping, and a high gauge factor up to ≈1100 is derived. Furthermore, the electrical properties show no deterioration after repeatedly bending the nanomembranes for 10 000 times at a radius of 1 cm. The VO2 nanomembrane sensors are utilized to monitor the radial artery pulse, and totally reproducible waveforms with ultrahigh sensitivity to the tactile stimuli are observed. Moreover, the power dissipation of the VO2 tactile sensors can be lowered down to the picowatt level, allowing for the future construction of self‐powered sensing systems together with nanogenerators. This study provides a substantial step toward large‐scale preparation of oxide nanomembranes and therefore paves a promising way for flexible oxide electronics.
Interface‐Modification‐Induced Gradient Energy Band for Highly Efficient CsPbIBr2 Perovskite Solar Cells
Authors: Subhani Waqas Siddique , Wang Kai , Du Minyong , Wang Xiuli , Liu Shengzhong (Frank) 
Published: April 2019

AbstractInorganic cesium lead halide perovskite solar cells (PSCs) have received enormous attention due to their excellent stability compared with that of their organic–inorganic counterparts. However, the lack of optimization strategies leads the inorganic PSCs to suffer from low efficiency arising from significant recombination. To overcome this dilemma, a surface modification of the electron transport layer (ETL)/perovskite interface is undertaken by using SmBr3 to improve the crystallization and morphology of the perovskite layer for enhanced ETL/perovskite interface interaction. Encouragingly, a gradient energy band is created at the interface with an outstanding hole blocking effect. As a result, both the charge recombination occurring at the interface and the nonradiative recombination inside the perovskite are suppressed, and, simultaneously, the charge extraction is improved successfully. Therefore, the power conversion efficiency of the CsPbIBr2 PSCs is increased to as high as 10.88% under one sun illumination, which is 30% higher than its counterparts without the modification. It is logically inferred that this valuable optimization strategy can be extended to other analogous structures and materials.
Synthesis and Characterization of a Molecularly Designed High‐Performance Organodisulfide as Cathode Material for Lithium Batteries
Authors: Shadike Zulipiya , Lee Hung‐Sui , Tian Chuanjin , Sun Ke , Song Liang , Hu Enyuan , Waluyo Iradwikanari , Hunt Adrian , Ghose Sanjit , Hu Yongfeng , Zhou Jigang , Wang Jian , Northrup Paul , Bak Seong‐Min , Yang Xiao‐Qing 
Published: April 2019

AbstractAn innovative organodisulfide compound, 2,3,4,6,8,9,10,12‐Octathia biscyclopenta[b,c]‐5,11‐anthraquinone‐1,7‐dithione (TPQD), has been successfully designed, synthesized, and characterized as a cathode material for lithium batteries. A benzoquinone is introduced to coordinate with dithiolane through 1,4‐dithianes. The molecular structure, electrochemical performances, and the lithiation/delithiation mechanism of the TPQD cathode have been systematically investigated. TPQD can deliver an initial capacity of 251.7 mAh g−1 at a rate of C/10, which corresponds to the transfer of 4.7 electrons per formula. Highly reversible capacities and stable cyclic performances can be achieved at rates from C/10 to 5 C. Very interestingly, TPQD can retain a capacity of 120 mAh g−1 after 200 cycles at the 5 C rate, which is quite impressive for organodisulfide compounds. X‐ray absorption spectroscopy measurements and density functional theory calculation results suggest that such a high capacity is contributed by both O redox of the quinone group and the cleavage and recombination of the disulfide bond. Moreover, the extended π‐conjugation structure of the material, introduced by benzoquinone and dithiane, is beneficial for improving the high rate capability and cyclic stability. This study illustrates an innovative approach in designing new organodisulfide compounds with improved cyclability and rate capability as cathode materials for high performance lithium batteries.
Catalytic Generation of C1 Ammonium Enolates from Halides and CO for Asymmetric Cascade Reactions
Authors: Li Lu‐Lu , Ding Du , Song Jin , Han Zhi‐Yong , Gong Liu‐Zhu 
Published: April 2019

AbstractA general strategy for the design of asymmetric cascade reactions using readily available halides and carbon monoxide (CO) as substrates is developed. The key is the catalytic generation of C1‐ammonium enolates for the subsequent asymmetric cascade reactions through the combination of palladium‐catalyzed carbonylation and chiral Lewis base catalysis. Utilizing this strategy, we have established asymmetric formal [1+1+4] and [1+1+2] reactions to afford chiral dihydropyridones and β‐lactams with high yields and high enantio‐ and diastereoselectivities.
Catalytic Asymmetric (4+3) Cyclizations of In Situ Generated ortho‐Quinone Methides with 2‐Indolylmethanols
Authors: Sun Meng , Ma Chun , Zhou Si‐Jia , Lou Sai‐Fan , Xiao Jian , Jiao Yinchun , Shi Feng 
Published: April 2019

AbstractThe first catalytic asymmetric (4+3) cyclization of in situ generated ortho‐quinone methides with 2‐indolylmethanols has been established, which constructed seven‐membered heterocycles in high yields (up to 95 %) and excellent enantioselectivity (up to 98 %). This approach not only represents the first catalytic asymmetric (4+3) cyclization of o‐hydroxybenzyl alcohols, but also enabled an unprecedented catalytic asymmetric (4+3) cyclization of 2‐indolylmethanols. In addition, a scarcely reported catalytic asymmetric (4+3) cyclization of para‐quinone methide derivatives was accomplished.
Nitriding‐Interface‐Regulated Lithium Plating Enables Flame‐Retardant Electrolytes for High‐Voltage Lithium Metal Batteries
Authors: Tan Shuang‐Jie , Yue Junpei , Hu Xin‐Cheng , Shen Zhen‐Zhen , Wang Wen‐Peng , Li Jin‐Yi , Zuo Tong‐Tong , Duan Hui , Xiao Yao , Yin Ya‐Xia , Wen Rui , Guo Yu‐Guo 
Published: April 2019

AbstractSafety concerns are impeding the applications of lithium metal batteries. Flame‐retardant electrolytes, such as organic phosphates electrolytes (OPEs), could intrinsically eliminate fire hazards and improve battery safety. However, OPEs show poor compatibility with Li metal though the exact reason has yet to be identified. Here, the lithium plating process in OPEs and Li/OPEs interface chemistry were investigated through ex situ and in situ techniques, and the cause for this incompatibility was revealed to be the highly resistive and inhomogeneous interfaces. Further, a nitriding interface strategy was proposed to ameliorate this issue and a Li metal anode with an improved Li cycling stability (300 h) and dendrite‐free morphology is achieved. Meanwhile, the full batteries coupled with nickel‐rich cathodes, such as LiNi0.8Co0.1Mn0.1O2, show excellent cycling stability and outstanding safety (passed the nail penetration test). This successful nitriding‐interface strategy paves a new way to handle the incompatibility between electrode and electrolyte.
Efficient Electrochemical Reduction of CO2 to HCOOH over Sub‐2 nm SnO2 Quantum Wires with Exposed Grain Boundaries
Authors: Liu Subiao , Xiao Jing , Lu Xue Feng , Wang Jiong , Wang Xin , Lou Xiong Wen (David) 
Published: April 2019

AbstractElectrochemical reduction of CO2 could mitigate environmental problems originating from CO2 emission. Although grain boundaries (GBs) have been tailored to tune binding energies of reaction intermediates and consequently accelerate the CO2 reduction reaction (CO2RR), it is challenging to exclusively clarify the correlation between GBs and enhanced reactivity in nanostructured materials with small dimension (<10 nm). Now, sub‐2 nm SnO2 quantum wires (QWs) composed of individual quantum dots (QDs) and numerous GBs on the surface were synthesized and examined for CO2RR toward HCOOH formation. In contrast to SnO2 nanoparticles (NPs) with a larger electrochemically active surface area (ECSA), the ultrathin SnO2 QWs with exposed GBs show enhanced current density (j), an improved Faradaic efficiency (FE) of over 80 % for HCOOH and ca. 90 % for C1 products as well as energy efficiency (EE) of over 50 % in a wide potential window; maximum values of FE (87.3 %) and EE (52.7 %) are achieved.
Mixed‐Metal MOFs: Unique Opportunities in Metal–Organic Framework (MOF) Functionality and Design
Authors: Masoomi Mohammad Yaser , Morsali Ali , Dhakshinamoorthy Amarajothi , Garcia Hermenegildo 
Published: April 2019

AbstractMixed‐metal metal–organic frameworks (MM‐MOFs) can be considered to be those MOFs having two different metals anywhere in the structure. Herein we summarize the various strategies for the preparation of MM‐MOFs and some of their applications in adsorption, gas separation, and catalysis. It is shown that compared to homometallic MOFs, MM‐MOFs bring about the opportunity to take advantage of the complexity and the synergism derived from the presence of different metal ions in the structure of MOFs. This is reflected in a superior performance and even stability of MM‐MOFs respect to related single‐metal MOFs. Emphasis is made on the use of MM‐MOFs as catalysts for tandem reactions.
Atypical Lone Pair–π Interaction with Quinone Methides in a Series of Imido‐Ferrociphenol Anticancer Drug Candidates
Authors: Wang Yong , Pigeon Pascal , Top Siden , Sanz García Juan , Troufflard Claire , Ciofini Ilaria , McGlinchey Michael J. , Jaouen Gérard 
Published: April 2019

AbstractFerrociphenols, especially those possessing a heterocycle at the terminus of an aliphatic chain, display strong anticancer activity through a novel redox mechanism that generates active metabolites such as quinone methides (QMs). X‐ray crystallography and UV/Vis spectroscopy reveal that the specific lone pair (lp)–π interaction between a carbonyl group of the imide and the quinone motif of the QM plays an important role in the exceptional cytotoxic behaviour of their imido‐ferrociphenol precursors. This intramolecular lp–π interaction markedly enhanced the stability of the QMs and lowered the pKa values of the corresponding phenol/phenolate couples. As the first example of such a non‐covalent interaction that stabilizes QMs remotely, it not only expands the scope of the lp–π interaction in supramolecular chemistry, but also represents a new mode of stabilization of a QM. This unprecedented application of lp–π interactions in imido‐ferrociphenol anticancer drug candidates may also have great potential in drug discovery and organocatalyst design.
An In‐Depth Look at the Reactivity of Non‐Redox‐Metal Alkylperoxides
Authors: Pietrzak Tomasz , Justyniak Iwona , Kubisiak Marcin , Bojarski Emil , Lewiński Janusz 
Published: April 2019

AbstractOver the past 150 years, a certain mythology has arisen around the mechanistic pathways of the oxygenation of organometallics with non‐redox‐active metal centers as well as the character of products formed. Notably, there is a widespread perception that the formation of commonly encountered metal alkoxide species results from the auto‐oxidation reaction, in which a parent metal alkyl compound is oxidized by the metal alkylperoxide via oxygen transfer reaction. Now, harnessing a well‐defined zinc ethylperoxide incorporating a β‐diketiminate ligand, the investigated alkylperoxide compounds do not react with the parent metal alkyl complex as well as Et2Zn to form a zinc alkoxide. Upon treatment of the zinc ethylperoxide with Et2Zn, a previously unobserved ligand exchange process is favored. Isolation of a zinc hydroxide carboxylate as a product of decomposition of the parent zinc ethylperoxide demonstrates the susceptibility of the latter to O−O bond homolysis.
Reimagining life and death: Results and interpretation of geophysical and ethnohistorical investigations of earth mounds, Mapoon, Cape York Peninsula, Queensland, Australia
Authors: ST PIERRE EMMA , CONYERS LAWRENCE , SUTTON MARY‐JEAN , MITCHELL PETER , WALKER CHESTER , NICHOLLS DIANNE 
Published: April 2019

ABSTRACTGround‐penetrating radar (GPR) and magnetic surveys were conducted on 13 earth mounds within Mapoon Aboriginal Lands, western Cape York Peninsula, Queensland. Detailed analysis of GPR profiles and amplitude maps of the mounds were compared to those from previously recorded, known burials at the Mapoon Mission Cemetery. Based on these models, burials were identified in ten of the 13 mounds. Both European‐style (coffin) and traditional burials were identified, suggesting that they were used for human interment for some time and that there may have been continuity of burial practice in these features after European contact. GPR and magnetics also indicate that a number of mounds had constructed floors or platforms at the base of the mounds, and evidence for burning. Stratigraphic layers identified with GPR show that many of these mounds have complex internal layering, suggesting multiple building episodes. Based on the GPR and magnetics results, in conjunction with ethnohistorical and oral history research, we conclude that the mounds are constructed features that appear to have had a long history of use for multiple purposes, including mortuary. These results demonstrate the cultural continuity of mortuary practices within Mapoon from pre‐contact times to the present.