bluuebunny/crossref_metadata_2025 huggingface dataset:
Scientific Argumentation in Chemistry Education: Implications and Suggestions
Authors: Hong Lee Yeng , Talib Corrienna Abdul
Published: October 2018

The Malaysia Education Blueprint 2012-2025 reveals the aspiration of government to prepare Malaysian children to meet the challenges of a 21st century economy. Nonetheless, Malaysia has a long way to go to achieve this target. PISA (2015) result indicates that Malaysian students have problems in reasoning skills. To achieve the target, Educational Blueprint advocates infusion of inquiry-based instruction in classrooms for students to acquire critical thinking skill. Critical thinking skill is a 21st century learning skill the students need to possess in today’s global economy. This skill includes the ability of individual to reason effectively. Scientific argumentation is a skill to promote critical thinking of students. Being the essential element of scientific inquiry and important activity in scientific reasoning, scientific argumentation helps students to develop and refine scientific knowledge. It is imperative to implement scientific argumentation in science classrooms. The purpose of this paper aims to raise some issues, including the results of previous studies about the impact of scientific argumentation on science achievement, the rationale for focusing on monological models in the three classification of argumentation models, and address the issues about the appropriateness of Toulmin argument model (an example of monologoical models), which is prevailed in science education to promote students’ scientific argumentation skills. Finally, this paper will outline some suggestions regarding implementation of Toulmin argument model to promote scientific argumentation in chemistry education.
Employability Skills Based on Polytechnic Graduate Job Role: Immediate Supervisor Perception
Authors: Rahmat Normala , Buntat Yahya , Ayub Abdul Rahman
Published: October 2018

Twenty first century employers need quality graduates to be competitive in global currents. This study was conducted to identify the importance of employability skills constructs required to improve the work performance based on the perception of the immediate supervisor’s in the polytechnic electronic graduates’ job role. This study uses a descriptive survey study involving a quantitative approach. Data collection was done by obtaining and analyzing quantitative data through self-developed questionnaire consisting of 31 items based on seven constructs of employability skills such as communication skills; personal qualities; teamwork skills; critical thinking skills and problem solving; technology skills; organizational skills and continuous learning skills. The sample consists of 170 immediate supervisors who represent the employers in four units of electrical and electronics industries namely research and development unit, maintenance unit, production unit and; quality and assurance unit. The findings of the quantitative study were analyzed using the Winstep V3.69.1.11 software. The findings of the analysis of the importance level of employability skills construct needed to improve work performance in all units are high with different priority rankings based on the role of graduates in the unit. In addition, the findings also show that critical thinking skills and problem solving are the most important employability skill constructs as well as the personal qualities and the latter are technology skills that must be owned and possesses by graduates who choose career paths in the electrical and electronic industries. Therefore, with the clarity of the concept of employability skills based on the job role as a result of this study it will facilitate graduates to adapt to the current wave of industrial change towards the concept of industry 4.0 with the application of precise employability skills oriented in the polytechnic electrical engineering curriculum.
A Meta-Analysis: The Effects of Child Sexual Abuse Towards Children
Authors: Zainudin Nurul Farhana Binti , Ashari Zakiah Binti Mohamad
Published: October 2018

Recently, cases of sexual abuse against children became a phenomena and it is a traumatic events that give a deep impact towards the victim. Therefore, the purpose of this study was to conduct a meta- analysis on a published researched about effects of child sexual abuse towards children. There were 20 journal articles collected from Science Direct, SpringerLink, Willey Online Library and Web of Science databases with the keywords ‘child sexual abused’ ‘behavior’, ‘emotional’, ‘social’ and ‘academic’ being used. The year of papers selected were from 2010 until 2017. The researcher differentiated and analyzed the effect of child sexual abuse toward four themes: internalizing and externalizing behavior, emotional regulation, suicidal behavior and academic achievement and performance. The findings from this study shown that child with previous experiences as victims in child abuse display internalizing and externalizing behavior and poor on academic achievement and performance. The findings also shown that the sexually abused children especially girls has low emotional regulation and the victims also had suicidal ideation and suicidal attempt. The implication from this study was to provide the insight for future researchers on the effects of child sexual abuse in behavior, emotional, social and academic aspects. Since this study only focused on the effect of sexual abuse towards children, it was suggested that for future researches, the effects of sexual abuse towards different range of age such as adult with history of sexual abused should be further investigated and more effects apart from behavioral, emotional, social and academic should be considered.
Programming Skills and the Relation in Fostering Students’ Higher Order Thinking
Authors: Alshaye Ibrahim Abdullah , Jumaat Nurul Farhana , Tasir Zaidatun
Published: October 2018

Programming skills (PS) refer to coding and debugging that are required for those who write a program in any programming language. Coding can be described as the implementation aspect of programming, whereas debugging can broadly be defined as fixing any incorrect code that is found after running the programming test. Higher-order thinking skills (HOTs) refer to the top three levels of Bloom’s taxonomy which are Analysis, Synthesis, and Evaluation. This study aims to determine the relationship between PS and HOTs among secondary students. Many studies indicate that students who attend programming courses for first time have low levels of performance in PS. Coding and debugging skills reflect higher-order thinking levels. Therefore, an objective of this study was to investigate the effect of coding and debugging skills on their HOTs. The benefits of having PS among learners are that they are able to achieve HOTs. Indeed, these relationships may be explained by programmers need to apply all these HOTs throughout the three phases of the programming process. Students who have low levels of PS are able to achieve the analysis level, while students who have moderate levels of PS able to achieve the synthesis level, and finally, students with high levels of PS are able to achieve the evaluation level.
Het fideicommis en temporele problemen bij plaatsvervulling voor verwachters
Authors: Brinkman R.E.
Published: October 2018

Het fideicommis en temporele problemen bij plaatsvervulling voor verwachters

In dit artikel worden enkele problemen besproken bij plaatsvervullings- en aanwasregelingen in fideicommissen. De problemen kunnen ontstaan door gebeurtenissen (zoals het overlijden van de eerstaangewezen verwachter) hangende de voorwaarde.
Testeren door minderjarigen en de maatschappelijke behoefte van artikel 4:58 BW
Authors: de Jonge H.J.
Published: October 2018

Testeren door minderjarigen en de maatschappelijke behoefte van artikel 4:58 BW

Minderjarigen die de leeftijd van 16 jaar hebben bereikt, kunnen uiterste wilsbeschikkingen maken. Uit cijfers verstrekt door de KNB blijkt dat op jaarbasis gemiddeld enkele tientallen testamenten door minderjarigen worden opgesteld. Dat was onder het oude erfrecht al zo. Indien een minderjarige testeert, mag hij op grond van artikel 4:58 BW geen uiterste wilsbeschikking maken ten voordele van zijn leermeester, met wie hij tezamen woont. In de literatuur wordt gesteld dat artikel 4:58 BW thans vrijwel achterhaald is en nauwelijks nog betekenis heeft. Ondanks het feit dat de resultaten van een door mij verricht praktijkonderzoek anders laten zien dan de heersende opvatting in de literatuur, ben ik het met deze stelling eens. Naar mijn mening is er voldoende reden om te stellen dat artikel 4:58 BW thans niet meer in een maatschappelijke behoefte voorziet. Daarnaast is er de bijstand van een notaris bij het opstellen van uiterste wilsbeschikkingen om ongewenste beïnvloeding van de testateur te voorkomen.
Measurements of 50 Non-polar Organic Compounds Including Polycyclic Aromatic Hydrocarbons, n-Alkanes and Phthalate Esters in Fine Particulate Matter (PM2.5) in an Industrial Area of Chiba Prefecture, Japan
Authors: Ichikawa Yujiro , Watanabe Takehisa , Horimoto Yasuhide , Ishii Katsumi , Naito Suekazu
Published: October 2018

Quantitative data of 50 non-polar organic compounds constituting PM2.5 were continuously collected and analyzed from June 2016 to October 2017 (approximately 17 months) at Ichihara, one of the largest industrial areas in Japan. Target non-polar organic compounds including 21 species of polycyclic aromatic hydrocarbons (PAHs), 24 species of n-alkanes and 5 species of phthalate esters (PAEs) were simultaneously measured by gas chromatography/mass spectrometry. Basically, the average concentrations of the total PAHs, n-alkanes and PAEs in each season remained nearly level, and seasonal variations were little throughout the study period. These results suggest that the emission sources, which are not influenced by the seasons, are the dominant inputs for the target organic compounds. Diagnostic ratios of PAHs, assessment of n-alkane homologue distributions, carbon preference index, and the contribution of wax n-alkanes from plants were used to estimate source apportionments. These results indicate that anthropogenic sources were the main contributor for most PAHs and n-alkanes throughout the study period. The concentrations of PAEs selected in this study were low because emission amounts of these chemicals were little within the source areas of the sampling site. To our knowledge, this study is the first attempt to simultaneously measure a high number of non-polar organic compounds in PM2.5 collected from the ambient air of Japan, and the resultant data will provide valuable data and information for environmental researchers.
Regional Tourist Organizations as a Destination Management Companies – a Proffesional Model of Action
Authors: Fedyk Wojciech
Published: October 2018

Purpose. Assessment of contradictions existing in the environment of researchers regarding effective models of management among the tourism sector in regions, and especially the management of tourism promotion, and the author's attempt to develop a ROT model in the DMC formula as a model for increasing the effectiveness of the organization. Method. The method of research included desk research of written resources, including ROT statuses (analysis of the structure of their aims) and in-depth analysis of data acquired during the author’s own questionnaire research. The conclusions were drawn with the use of the deductive method, comparative analysis, and – to simplify the presentation of problems – the reduction method, as well as the authors’ own observations. Findings. The study revealed the possibility of changing the ROT business model using the DMC formula, which could be crucial in assessing the effectiveness of the organization. Research and conclusions limitations. The study involved 16 ROTs, and survey research data were obtained from 15 organizations. The analysis allowed, however, to notice and outline regularities in the ROT activity features and a catalogue of conditions in their environment affecting the efficiency of functioning after transformation into the DMC. Practical implications. The research diagnoses the possibilities and conditions of changes in the ROT model of action using the DMC formula in the opinion of the organization's stakeholders. Originality. The analysis and identification of the catalogue of conditions in the environment of ROTs, in the context of tourism policy issues, system of organization of tourism and the behaviour of organizations, focused on business activities. The ROT model of operation in the DMC formula. Type of paper. The article presents the results of empirical research.
Review of the Book by Adam Szromek ”Organization of SPA Tourism and SPA Treatment”
Authors: Kruczek Zygmunt
Published: October 2018

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Calcifying Nested Stromal-Epithelial Tumor of the Liver: An Update and Literature Review
Authors: Benedict Mark , Zhang Xuchen
Published: October 2018

Calcifying nested stromal-epithelial tumor is a rare entity that has gone by a variety of names in the literature: ossifying malignant mixed epithelial and stromal tumor, ossifying stromal-epithelial tumor, and desmoplastic nested spindle cell tumor of the liver. To our knowledge, approximately 38 cases have been reported in the literature. The histogenesis is still largely unknown but histopathologically is characterized by nests of spindle and epithelioid cells in an organoid arrangement surrounded by a prominent dense myofibroblastic stroma with occasional psammomatous calcification and focal heterotopic ossification. Vascular invasion is rare and tumoral recurrence is uncommon with only a single reported case of metastasis leading to death. Treatment is mainly by surgical intervention with the role of chemotherapy seeming limited, but lack of data hinders a true recommendation. It is important to rule out other processes such as hepatoblastoma, calcified hemangioma, synovial sarcoma, metastatic gastrointestinal stromal tumor, desmoplastic small round cell tumor, among others, which appear similar radiographically and histopathologically.
Molecular Testing for Cutaneous Melanoma: An Update and Review
Authors: Lee Jonathan J. , Lian Christine G.
Published: October 2018

Context.—

The steady rise in the incidence of cutaneous malignant melanoma and its inherently difficult-to-interpret histopathology continues to fuel an increasing demand for diagnostically and prognostically insightful adjunctive molecular tests among both clinicians and dermatopathologists. A number of DNA, RNA, and epigenetically based assays have now been developed and are at various stages of experimental and/or clinical use.

Objective.—

To examine the evidence for the utility and limitations of these leading candidates for the diagnosis and risk stratification of melanoma and related melanocytic neoplasms.

Data Sources.—

The available English medical literature was reviewed in the preparation of this manuscript.

Conclusions.—

Comparative genomic hybridization, fluorescence in situ hybridization, RNA-based gene expression profiling, and immunohistochemical assays for novel genetic and epigenetic markers will help bring diagnostic and prognostic accuracy to the assessment of melanocytic neoplasms.
Carolina Maria de Jesus - de Bitita a Quarto de Despejo: enunciações dissonantes e as marcas de um discurso político
Authors: Sá Janaína Da Silva
Published: October 2018

Resumo: Esta análise visa à compreensão da obra da escritora mineira Carolina Maria de Jesus, cujo embate primordial está em conceber-se um novo espaço de enunciação para discursos tidos, até há pouco tempo, como inexpressivos e que, por conta desse juízo de valor, desapareciam ou eram negligenciados. A escritura dessa autora aponta para uma ressignificação das mentalidades e para um novo entendimento de valores significativos de nossa formação histórico-cultural, ressaltando um discurso político, uma vez que desvela as peculiaridades de um povo que tem, em sua matriz, o estigma da diversidade étnica.
Political discourse analysis (PDA): theoretical and practical considerations
Authors: DeSouza Vilmar Ferreira
Published: October 2018

O objetivo deste artigo é determinar, por meio da Linguística SistêmicoFuncional (LSF), como o modal dever é empregado e quais contornos semânticos apresenta nas vozes textuais dos políticos participantes das Audiências Públicas (APs). Para que este trabalho fosse realizado, foram selecionadas seis Audiências Públicas sobre meio ambiente e desenvolvimento sustentável correspondentes aos anos de 2012 e 2013 para identificação do grau de comprometimento dos políticos em seus discursos, ou seja, da modalidade. Os resultados indicam que as manifestações nas APs partem de uma orientação subjetiva implícita, pois os políticos são a fonte da convicção, ao mesmo tempo em que instigam a avaliação dos presentes na sessão.
A avaliação em um discurso do presidente Michel Temer: uma análise a partir dos recursos de gradação
Authors: Farencena Gessélda Somavilla , Santos Marli Ferraz dos
Published: October 2018

O presente trabalho é o resultado de uma análise do discurso do Presidente da República, Michel Temer, proferido durante a cerimônia de comemoração do Dia Internacional da Mulher de 2017. A questão principal deste estudo foi verificar como os recursos de gradação contribuíam para a construção da avaliação e para a caracterização do discurso quanto ao grau de envolvimento do Presidente. Nesse intuito, adotamos como principal aporte teórico o Sistema de Avaliatividade (WHITE, 2004; MARTIN; WHITE, 2015), de modo especial o subsistema de gradação.  Resultados mostraram a predominância de recursos de gradação do tipo força intensificação que contribuíram para construir a ideia de assertividade do discurso.
Using Secant Parabolas to Find Roots
Authors: Yang Yajun , Gordon Sheldon P.
Published: October 2018

Almost all root finding methods use linear functions to calculate the next approximation to a real root. The authors introduce a method based on using parabolas through three points and use one of the two roots via the quadratic formula to identify the following approximation.
Breaking down walls
Authors: Shaku Moagi Tube , Kana Bavesh Davandra
Published: October 2018

A better understanding of the mechanisms underpinning the growth of mycobacteria could help identify targets for new antibiotics.
Phylogenomics picks out the par excellence markers for species phylogeny in the genus Staphylococcus
Authors: Graña-Miraglia Lucia , Arreguín-Pérez César , López-Leal Gamaliel , Muñoz Alan , Pérez-Oseguera Angeles , Miranda-Miranda Estefan , Cossío-Bayúgar Raquel , Castillo-Ramírez Santiago
Published: October 2018

Although genome sequencing has become a very promising approach to conduct microbial taxonomy, few labs have the resources to afford this especially when dealing with data sets of hundreds to thousands of isolates. The goal of this study was to identify the most adequate loci for inferring the phylogeny of the species within the genus Staphylococcus; with the idea that those who cannot afford whole genome sequencing can use these loci to carry out species assignation confidently. We retrieved 177 orthologous groups (OGs) by using a genome-based phylogeny and an average nucleotide identity analysis. The top 26 OGs showed topologies similar to the species tree and the concatenation of them yielded a topology almost identical to that of the species tree. Furthermore, a phylogeny of just the top seven OGs could be used for species assignment. We sequenced four staphylococcus isolates to test the 26 OGs and found that these OGs were far superior to commonly used markers for this genus. On the whole, our procedure allowed identification of the most adequate markers for inferring the phylogeny within the genus Staphylococcus. We anticipate that this approach will be employed for the identification of the most suitable markers for other bacterial genera and can be very helpful to sort out poorly classified genera.
Are seductive details seductive only when you think they are relevant? An experimental test of the moderating role of perceived relevance
Authors: Eitel Alexander , Bender Lisa , Renkl Alexander
Published: October 2018

We investigated whether seductive details (i.e., interesting but irrelevant adjuncts) are harmful to learning only when students (mistakenly) think that they are relevant. We therefore conducted a study in which participants (N = 86) learned either without seductive details (control condition) or with seductive details—in the latter case with or without being informed about the seductive details' irrelevance. In line with our hypotheses, only participants who were not informed about the irrelevance of seductive details revealed worse learning outcomes than those in the control condition, thereby revealing a seductive details effect. Extraneous cognitive load, but not perceived time pressure, mediated the negative effects of being uninformed about the irrelevance of seductive details on learning outcomes. Taken together, our results suggest that the perceived relevance of seductive details is a boundary condition of the seductive details effect.
Distributing mathematical practice of third and seventh graders:Applicability of the spacing effect in the classroom
Authors: Barzagar Nazari Katharina , Ebersbach Mirjam
Published: October 2018

We examined the effect of distributed practice on the mathematical performance of third and seventh graders (N = 213) in school. Students first received an introduction to a mathematical topic, derived from their curriculum. Thereafter, they practiced in one of two conditions. In the massed condition, they worked on three practice sets in 1 day. In the distributed condition, they worked on one practice set per day for 3 consecutive days. Bayesian analyses of the performance in two follow‐up tests 1 and 6 weeks after the last practice set revealed a positive effect of distributed practice as compared with massed practice in Grade 7. In Grade 3, a positive effect of distributed practice was supported by the data only in the test 1 week after the last practice set. The results suggest that distributed practice is a powerful learning tool for both elementary and secondary school students in the classroom.
Architectured Leaf‐Inspired Ni0.33Co0.66S2/Graphene Aerogels via 3D Printing for High‐Performance Energy Storage
Authors: Tang Xingwei , Zhu Chengling , Cheng Dongdong , Zhou Han , Liu Xianghui , Xie Peiwen , Zhao Qibin , Zhang Di , Fan Tongxiang
Published: October 2018

The construction of high‐performance electrodes with sufficient active sites and interconnected networks for rapid electron/ions transport is challengeable for energy storage devices. Inspired by natural leaves, a facile 3D‐printing strategy for constructing architected Ni0.33Co0.66S2/graphene (3DP‐NCS/G) aerogels to mimic the analogous mass transfer process toward superior electrochemical performances is demonstrated. The key step is to develop hybrid inks with printability and homogeneity by introducing sodium alginate into graphene oxide solutions to boost viscoelastic responses and adopting a new developed precursor Ni0.33Co0.66(OH)2·xH2O with ultrafine and high stable features. Benefiting from high‐speed channels for electron/ion transport provided by the interconnected graphene frameworks and massive exposed edge sites provided by the uniformly dispersed Ni0.33Co0.66S2 nanoparticles, the 3DP‐NCS/G electrode exhibits capacities of 217.6 mAh g−1 at 1 A g−1 and 164.6 mAh g−1 at 10 A g−1. Furthermore, a hybrid device is demonstrated for the first time with both electrodes manufactured by 3D‐printing technique, which delivers excellent areal energy/power densities with values comparable to those of commercial devices, even at a practical level of electrode mass loading (17.86 mg cm−2). This work offers a versatile strategy for integrating various functional nanomaterials with programmable architectures toward myriad applications.
Coherent Pixel Design of Metasurfaces for Multidimensional Optical Control of Multiple Printing‐Image Switching and Encoding
Authors: Bao Yanjun , Yu Ying , Xu Haofei , Lin Qiaoling , Wang Yin , Li Juntao , Zhou Zhang‐Kai , Wang Xue‐Hua
Published: October 2018

Printing image based on metasurface has attracted enormous research interests due to its subwavelength resolution, full‐color printing, and durable properties. Based on the spatially multiplexed pixels, the printing image using metasurface can be switched optically by altering the optical parameters, such as polarization and incident wavelength. However, such multiplexed pixel design has several problems, including the cross‐talk among different wavelengths, limitation to linear polarizations, and incapability for incident‐angle control. Here, a general method for pixel design, called the coherent pixel, which can overcome the problems and be used for multiple printing‐image switching controlled by arbitrary optical parameters (arbitrary incident angle, polarization, and wavelength) is proposed. Based on this coherent pixel, metasurface devices with novel functionalities can be realized, such as incident‐angle controlled and arbitrary polarization‐controlled printing images, which are not feasible with previous conventional pixel design method. The suitability and superiority of the coherent pixel for encryption application is also discussed. Such printing‐image switching controlled with arbitrary optical parameters should pave the way for various applications, including various functional switchable optical devices, image displays, and information encryption.
Self‐Template Synthesis of Mesoporous Metal Oxide Spheres with Metal‐Mediated Inner Architectures and Superior Sensing Performance
Authors: Wang Gen , Qin Jing , Zhou Xinran , Deng Yonghui , Wang Huanting , Zhao Yongxi , Wei Jing
Published: October 2018

The development of a general strategy to synthesize mesoporous metal oxide spheres (MMOSs) with tailorable compositions and architectures is desirable and challenging. Herein, a general self‐template strategy is demonstrated for the synthesis of MMOSs with tunable compositions (i.e., ZnO, Al2O3, Co3O4, Fe2O3, CuO) and metal‐mediated inner architectures via thermal decomposition of metal‐phenolic coordination polymers (MPCPs). The metal species in MPCPs can obviously influence the decomposition temperature of the polymer networks (Td). The inner architectures of MMOSs are determined by Td and the crystallization temperature of metal oxides (Tc). The MMOSs show solid inner architectures when Td > Tc or Td < Tc and hollow structure when Td ≈ Tc. Encouraged by their high surface area and accessible mesopores, gas sensors based on MMOSs (i.e., ZnO) are fabricated, which shows a low working temperature (250 °C) for detection of ethanol gas. The MMOSs (i.e., Co3O4) can further be used to fabricate sensing platform for detecting DNA analogue of miRNA‐21 (a biomarker abnormally expressed in most of solid tumors). Such MMOSs show high sensitivity (0.19 × 10−9m) and can even efficiently distinguish the target DNA from single‐, double‐ and triple‐base mismatched DNA.
2D Transition Metal Dichalcogenide Thin Films Obtained by Chemical Gas Phase Deposition Techniques
Authors: Park Gyu‐Hyeon , Nielsch Kornelius , Thomas Andy
Published: October 2018

Ultrathin 2D transition metal dichalcogenide (TMD) thin films have attracted much attention due to their very good electrical, optical, and electrochemical properties. Chemical vapor deposition (CVD) and atomic layer deposition (ALD), which is in some regards an enhanced version of CVD, are techniques that can provide exceptionally conformal large‐area coatings, even for complex surface geometries. Besides, these techniques include the transport of one or more precursor chemicals in the gas phase onto a substrate. Subsequently, a chemical reaction occurs, resulting in the deposition of a film of a solid material on the substrate. One of the advantageous aspects of chemical deposition methods, such as CVD and ALD, is the growth of thin films onto a variety of substrates as well as 3D structures. Because of their chemical approach, these techniques are well suited to synthesizing 2D materials (2DMs) with a low defect concentration. Furthermore, the scalability would allow industrial application, as opposed to, e.g., micromechanical cleavage. Here, the recent progress in 2D TMD thin films is reviewed and the current applications of these materials fabricated by CVD and ALD are surveyed.
Mononuclear Silver Complexes for Efficient Solution and Vacuum‐Processed OLEDs
Authors: Romanov Alexander S. , Jones Saul T. E. , Yang Le , Conaghan Patrick J. , Di Dawei , Linnolahti Mikko , Credgington Dan , Bochmann Manfred
Published: October 2018

Carbene metal amides are a new class of highly efficient light‐emitting molecules based on a linear donor–metal–acceptor geometry. Here the synthesis, structure, and photo‐ and electroluminescence of carbene silver carbazolato complexes, (AdL)Ag(Cz) [AdL = adamantyl‐substituted cyclic (alkyl)(amino)carbene; Cz = carbazolate (1) and 3,6‐tBu2Cz (2)], are reported. They display green emission with photoluminescence quantum yields of up to 74%. Efficient mixing of triplet and singlet excited states is observed, with sub‐microsecond thermally activated radiative triplet lifetimes. These complexes provide prototype organic light‐emitting diodes based exclusively on silver emitters, with external quantum efficiencies of up to 14%.
Efficient Non‐Catalytic Carboxylation of Diamines to Cyclic Ureas Using 2‐Pyrrolidone as a Solvent and a Promoter
Authors: Hwang Junhyeok , Han Donggu , Oh Jin Joo , Cheong Minserk , Koo Hyun‐Joo , Lee Je Seung , Kim Hoon Sik
Published: October 2018

Carboxylation reactions of diamines were found to proceed rapidly and non‐catalytically, producing corresponding cyclic ureas in excellent yields and selectivities when 2‐pyrrolidone (2‐PY) was used as a solvent. A similar promoting effect with 2‐PY was also observed for the carboxylation of monoamines by carbon dioxide (CO2). Most notably, the carboxylation reactions of mono‐ and diamines conducted in 2‐PY afforded 2–4 times higher yields of corresponding dialkyl ureas and cyclic ureas compared with those in N‐methyl‐2‐pyrrolidone (NMP). Such a dramatic promoting effect using 2‐PY is believed to be associated with the multiple hydrogen bonding interactions between 2‐PY and the CO2‐containing species of amines. Due to such favorable interactions, carboxylation reactions seem to be more facilitated in 2‐PY than in NMP.

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Development of new bio‐based polyol ester from palm oil for potential polymeric drug carrier
Authors: Tajau Rida , Rohani Rosiah , Wan Isahak Wan Nor Roslam , Salleh Mek Zah , Ghazali Zulkafli
Published: October 2018

The polyol ester derived from palm oil polymers is a promising material for utilizing it as a polymeric drug carrier due to its natural and biocompatible properties. In this study, the palm oil‐based diol is used as a precursor for developing the polyol ester via the transesterification‐alcoholysis reaction of the diol with triethanolamine and lithium hydroxide. Preliminary results showed that the polyol ester displayed high hydroxyl value at 182.51 mgKOH/g with the yield reached more than 90%. Meanwhile, its molecular weight was around 5,000 Dalton. The appearances of ester (C–O) between 1,300 and 1,000 cm−1in the Fourier transform infrared (FTIR) spectra have confirmed the hydrolyzable ester structure of the polyol ester. Consequently, the δH‐ and δC‐NMRspectra also confirmed the presences of the ester proton (i.e., ‐COO–CH2‐) and the ester carbons (i.e., ‐CH2CH2CO(O)C‐, ‐CH2COO‐, ‐CH2C(O)OC‐). Thermogravimetric analysis of the polyol ester displayed three stages of maximum decomposition temperature (Tmax): 203.56°C, 362.79°C, and 481.91°C. Differential scanning chromatography (DSC) analysis indicated that the glass transition temperature (Tg) of the polyol ester was found between −3.27 and 7.5°C. As a result, the analyses affirmed that this polyol ester is a hydrolytically degradable polymer due to the presence of its hydrolyzable ester bonds. Its low molecular weight and low‐melting biodegradable properties could show a faster degradation compared to the higher molecular weight synthetic polymers. Thus, the characteristic of the developed polyol ester demonstrates promising physicochemical and good thermal properties, which makes it a potential candidate for a polymeric drug delivery system.
Effect of the novel biodegradable copolymer and soil salinity on the growth of corn plant
Authors: Torğut Gülben , Beker Akbulut Gülcin
Published: October 2018

Biodegradable and biocompatible poly (1,2‐epoxy‐3‐phenoxy propane)‐co‐(ε‐caprolactone) poly(EPP‐co‐ε‐CL) copolymers were synthesized by ring‐opening polymerization method at four different ε‐CL ratios. Copolymers were characterized using Fourier‐transform infrared spectroscopy, proton nuclear magnetic resonance (1H‐NMR), thermogravimetric analysis, and differential scanning calorimetry. To examine their possible applications in agriculture, germination test and growth analyses of corn plants were carried out. For this purpose, corn (Zea mays L. cv. “72 May 80”) was allowed to germinate under suitable conditions. Copolymers, 200 mM salt (NaCl) solution, and both copolymers and salt solution were applied to the plants and compared with the control groups. On the 21st day, all the plants were harvested and were stored at −80°C until analysis. Differences in growth parameters, lipid peroxidation degrees, pigment analysis, and total carbohydrate analysis were tested in order to put forward copolymer and NaCl sensitivity of the corn. Statistical analysis was carried out using the SPSS 17.0 software program and the results were compared with each other. These results showed that the copolymers both have a positive effect on the carbohydrate and malondialdehyde (MDA), a product of lipid peroxidation content as well as the chlorophyll content. Moreover, poly(EPP‐co‐ε‐CL0.88) was more efficient than was the other copolymers in the improvement of the detrimental effects of salinity in increasing chlorophyll, carbohydrate, and MDA content, and growth of corn plants. As a result of the study, it was demonstrated that all of the investigated parameters were affected by the applications of salt and copolymers.
Enhanced Raman Investigation of Cell Membrane and Intracellular Compounds by 3D Plasmonic Nanoelectrode Arrays
Authors: Caprettini Valeria , Huang Jian‐An , Moia Fabio , Jacassi Andrea , Gonano Carlo Andrea , Maccaferri Nicolò , Capozza Rosario , Dipalo Michele , De Angelis Francesco
Published: October 2018

3D nanostructures are widely exploited in cell cultures for many purposes such as controlled drug delivery, transfection, intracellular sampling, and electrical recording. However, little is known about the interaction of the cells with these substrates, and even less about the effects of electroporation on the cellular membrane and the nuclear envelope. This work exploits 3D plasmonic nanoelectrodes to study, by surface‐enhanced Raman scattering (SERS), the cell membrane dynamics on the nanostructured substrate before, during, and after electroporation. In vitro cultured cells tightly adhere on 3D plasmonic nanoelectrodes precisely in the plasmonic hot spots, making this kind of investigation possible. After electroporation, the cell membrane dynamics are studied by recording the Raman time traces of biomolecules in contact or next to the 3D plasmonic nanoelectrode. During this process, the 3D plasmonic nanoelectrodes are intracellularly coupled, thus enabling the monitoring of different molecular species, including lipids, proteins, and nucleic acids. Scanning electron microscopy cross‐section analysis evidences the possibility of nuclear membrane poration compatible with the reported Raman spectra. These findings may open a new route toward controlled intracellular sampling and intranuclear delivery of genic materials. They also show the possibility of nuclear envelope disruption which may lead to negative side effects.
Excitation Density Dependent Photoluminescence Quenching and Charge Transfer Efficiencies in Hybrid Perovskite/Organic Semiconductor Bilayers
Authors: Kim Jinhyun , Godin Robert , Dimitrov Stoichko D. , Du Tian , Bryant Daniel , McLachlan Martyn A. , Durrant James R.
Published: October 2018

This study addresses the dependence of charge transfer efficiency between bilayers of methylammonium lead iodide (MAPI3) with PC61BM or poly(3,4‐ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) charge transfer layers on excitation intensity. It analyzes the kinetic competition between interfacial electron/hole transfer and charge trapping and recombination within MAPI3 by employing a range of optical measurements including steady‐state (SS) photoluminescence quenching (PLQ), and transient photoluminescence and absorption over a broad range of excitation densities. The results indicate that PLQ measurements with a typical photoluminescence spectrometer can yield significantly different transfer efficiencies to those measured under 1 Sun irradiation. Steady‐state and pulsed measurements indicate low transfer efficiencies at low excitation conditions (<5E + 15 cm−3) due to rapid charge trapping and low transfer efficiencies at high excitation conditions (>5E + 17 cm−3) due to fast bimolecular recombination. Efficient transfer to PC61BM or PEDOT:PSS is only observed under intermediate excitation conditions (≈1 Sun irradiation) where electron and hole transfer times are determined to be 36 and 11 ns, respectively. The results are discussed in terms of their relevance to the excitation density dependence of device photocurrent generation, impact of charge trapping on this dependence, and appropriate methodologies to determine charge transfer efficiencies relevant to device performance.
Nickel compounds in the workplaces: Occupations and activities involving high‐risk exposures in Italy
Authors: Scarselli Alberto , Di Marzio Davide , Marinaccio Alessandro , Iavicoli Sergio
Published: October 2018

Background

Nickel (Ni) compounds have been classified as carcinogenic to humans. The aim of the study is to evaluate exposures to Ni at workplaces in Italy.

Methods

Data on Ni compounds were collected from an occupational exposure registry. Statistical analysis was carried out for exposure‐related variables. The number of workers potentially exposed was estimated for selected industrial sectors. Concurrent exposures with other occupational carcinogens were investigated using two‐step cluster analysis.

Results

Overall 10 083 measurements were analyzed during 1996‐2016, having a geometric mean of 2.93 μg/m3. Most exposures occurred in manufacture of metal products (50%) and among metal finishing machine operators (46%). A total of 56 046 workers potentially exposed to Ni was estimated. Concurrent exposures were frequently detected, mainly with chromium VI and cobalt compounds.

Conclusions

Systematic recording of occupational exposures provides a data source that allows recognition of high risk situations for workers’ health and helps improve exposure assessment in epidemiologic studies.
One‐Pot Oxidative Aromatization and Dearomatization of Tetrahydro[5]helicene Diols: Synthesis, Structure, Photophysical and Chiroptical Properties of Chiral π‐Extended Diones
Authors: Fang Lei , Li Meng , Lin Wei‐Bin , Shen Yun , Chen Chuan‐Feng
Published: October 2018

One‐pot oxidative aromatization and dearomatization (OADA) reactions of tetrahydro[5]helicene diols with 2,3‐dichloro‐5,6‐dicyanobenzoquinone (DDQ) as the oxidant were demonstrated, which provided an efficient method for the synthesis of chiral π‐extended diones. Consequently, a series of enantiomeric π‐extended diones were obtained in high yields by a one‐pot OADA of dibromo‐substituted tetrahydro[5]helicene diols, and then followed by Suzuki‐Miyaura cross‐coupling reactions, or vice versa. The absolute configurations of the chiral diones were determined by their CD spectral analysis and X‐ray structure of the dibromo‐substituted dione. Moreover, the enantiomeric diones also exhibited mirror‐imaged CD spectra and showed mirror‐imaged circularly polarized luminescence (CPL) properties with the luminescence dissymmetry factor up to ±9.0×10−4. It was further found that the chiral diones showed different fluorescence spectra, and substituent‐dependent fluorescence quantum yields. For the chiral diones with strong electron‐donating groups, high fluorescence quantum yields of up to 30.3% were found. Such chiral diones with high fluorescence quantum yields and significant CPL properties might have potential applications not only in asymmetric catalytic synthesis, but also chiroptical materials.
Boranchemie aus einer neuen Perspektive: Nukleophilie der B‐H‐Bindungselektronen
Authors: Zhao Qianyi , Dewhurst Rian D. , Braunschweig Holger , Chen Xuenian
Published: October 2018

Eine ganze Reihe erst kürzlich verwirklichter nukleophiler Borverbindungen wie Borylanionen oder Borylene brechen die üblichen mit dem Element Bor bzw. borhaltigen Verbindungen assoziierten Regeln und verhalten sich keineswegs wie Lewis‐Säuren bzw. Elektrophile. Auch das B‐H‐Bindungselektronenpaar in Boranen zeigt häufig einen nukleophilen Charakter, was im Allgemeinen auf die geringere Elektronegativität von Bor im Vergleich zu Wasserstoff zurückgeführt wird. Obwohl diese Eigenschaft bislang eher wenig Aufmerksamkeit erregt hat, ermöglichten erste Studien zur Nukleophilie der B‐H‐Bindungselektronen bereits die Entdeckung interessanter Strukturmotive mit B‐H‐B‐verbrückten Einheiten und B‐H⋅⋅⋅H‐Y‐Wasserstoffbrücken, auf deren Grundlage sich ein komplett eigenständiges Forschungsgebiet entwickelt hat. Hierzu zählen unter anderem 1) die Aufklärung der mechanistischen Details zur Bildung von Aminodiboran (ADB), des Diammoniakats von Diboran (DADB) sowie der Lithium‐ und Natriumsalze von Octahydrotriborat (B3H8−) und 2) die Entwicklung verbesserter experimenteller Zugänge zu diesen Reagenzien. Eine umfassende Auseinandersetzung mit den nukleophilen Eigenschaften des B‐H‐Bindungselektronenpaares hat zudem zu einem tieferen Verständnis der unterschiedlichen Mechanismen von Hydroborierungsreaktionen beigetragen.
Successive Protonation of an N‐Heterocyclic Imine Derived Carbonyl: Superelectrophilic Dication Versus Masked Acylium Ion
Authors: Loh Ying Kai , Ángeles Fuentes M. , Vasko Petra , Aldridge Simon
Published: October 2018

Carbonyl cations are among the most commonly invoked reactive intermediates in organic synthesis. While Olah pioneered superacids to provide a “stable ion” environment for their study in situ, isolated examples are rare. Here, we disclose successive protonation of an N‐heterocyclic imine (NHI) derived carbonyl compound (IDippN)2CO,2, to the monocation [(IDippN)(IDippNH) CO]+, [3]+, and the doubly protonated dication [(IDippNH)2CO]2+, [4]2+. [3]+represents a rare example of an N‐protonated carbonyl cation and [4]2+the first example of a superelectrophilic carbonyl dication. All three compounds have been characterized by X‐ray crystallography and IR spectroscopy, revealing stepwise strengthening of the C=O bond on protonation. The unique stability of these systems is attributed to the enhanced basicity and steric profile provided by the NHI substituents. In addition, we report the related singly NHI‐stabilized cation [IDippNCO]+, [5]+. Crystallographic and DFT analyses provide insight into the interaction between the carbonyl fragment and the NHI, which reveals that the [CNCO]+unit (isoelectronic to CCCO) can be described as an acylium cation “masked” as a cumulene.
Single bubble breakup in the flow field induced by a horizontal jet—The experimental research
Authors: Feng Junjie , Cao Jiaying , Jiang Jie , Sun Bing , Cai Ziqi , Gao Zhengming
Published: October 2018

Bubble breakup in multiphase reactors has a direct and important impact on the mass transfer and reaction process. This paper experimentally investigated the single bubble behaviors of deformation and breakup under the affecting of a jet submerged in a water‐filled tank. The dispersed phase motion was captured by a high speed camera, while the continuous phase flow field was analyzed by Particle Image Velocimetry. By changing the downstream location of bubble generation, the liquid flow rate and the initial bubble size, the breakup processes were analyzed and discussed. The breakup point, break pattern, and distribution of daughter bubbles were summarized. The position where the bubble gets the maximum acceleration was defined as the shear position, and the forces on the bubble at the shear position had a significant impact on whether breakup will occur. The expected bubble number, which could reflect a combination of the breakup probability and daughter bubbles distribution, was defined and found to be directly proportional to the capillary number of bubbles at the shear position. The research result will contribute to promoting the understanding and control of multiphase flow, and providing a theoretical basis and technical support for the design and optimization of multiphase reactors.
Cell‐Selective Delivery of MicroRNA with a MicroRNA–Peptide Conjugate Nanocomplex
Authors: Xiao Xiao , Wang Xingxing , Gao Haidong , Chen Xi , Li Jinbo , Zhang Yan
Published: October 2018

Targeted delivery of microRNA (miRNA) into specific cells has been regarded as an efficient strategy to enhance miRNA‐targeted therapeutics. However, concurrent delivery of therapeutic miRNAs into different target cells that is conducive to multi‐target therapy is still underdeveloped. Here, we report a novel strategy for cell‐selective delivery of miRNA into different target cells by using miRNA nanocomplexes (MINRCs) formed by miRNA with peptide conjugates. The peptide conjugates comprised a cationic cell‐penetrating peptide nona‐arginine and a targeting ligand that is cyclic RGD or folic acid. Upon mixing in buffer, the peptide conjugates and miR‐34a readily formed two MINRCs, respectively. These two MINRCs facilitated the targeted delivery of miR‐34a into RGD receptor‐positive U87MG cells or folate receptor‐positive HeLa cells via ligand–receptor interaction. We also demonstrated that co‐incubation of these two MINRCs with U87MG and HeLa cells led to cell‐selective delivery of miR‐34a.
GC–MS Method for the Quantitative Analysis of Limonene from Genetically Engineered Saccharomyces cerevisiae
Authors: Son Minhee , Yang Jeongmo , Cho Sukhyeong , Lee Jinwon , Oh Han Bin
Published: October 2018

In this study, a gas chromatography–mass spectrometry (GC–MS) analysis method was developed and validated for the quantitative analysis of limonene that was attempted to be industrially mass‐produced from genetically engineered Saccharomyces cerevisiae (S. cerevisiae). Owing to the high potential economic value of limonene, (e.g., for biofuels, fragrant additives, pharmaceuticals, or organic solvents), it is important to develop and validate a readily available quantitative analysis method for limonene produced from genetically engineered yeast or microorganisms. The engineered S. cerevisiae was cultured using two‐phase extractive fermentation with n‐dodecane, which is known to alleviate monoterpene toxicity, used as an extractive solvent. The quantitative GC–MS analysis of the n‐dodecane overlay that contained limonene produced from the engineered S. cerevisiae was validated to be in accord with the international standards set forth by the Food and Drug Administration.