bluuebunny/crossref_metadata_2025 huggingface dataset:
УЧЕЊЕ И ЕМОЦИЈЕ УЧЕНИКА У ДИГИТАЛНОМ ОКРУЖЕЊУ
Authors: Вукановић Немања
Published: April 2019

У савременом друштву какво јеи наше већ двије деценије актуелнасу друштвена и нормативно-правнаопредјељења када је ријеч о дигита-лизацији процеса учења. Развојни путдигитализације процеса учења, одприједлога до афирмације, захтијеванаучна сазнања о томе у којој мјеритакво учење истински прихватајуученици, учитељи и родитељи.Експлицирајући релевантна тео-ријска полазишта, рад садржи ана-лизиране резултате емпиријског ис-траживања учења и емоција ученикау дигиталном окружењу на узорку од116 ученика осмог и деветог разредаса подручја Бањалуке и Приједора.Установљено је да не постоје стати-стички значајне разлике у процјенамаученика према полу и општем школ-ском успјеху, док је пронађена мини-мална статистички значајна повеза-ност између времена ког ученици про-веду радећи за рачунаром и њиховихпроцјена.
Identification and differential expression of piRNAs in the gonads of Amur sturgeon (Acipenser schrenckii)
Authors: Yuan Lihong , Li Linmiao , Zhang Xiujuan , Jiang Haiying , Chen Jinping
Published: April 2019

Objective

Sturgeons are considered living fossils, and have a very high conservation and economic value. Studies on the molecular mechanism of sturgeon gonadal development and sex differentiation would not only aid in understanding vertebrate sex determination but also benefit sturgeon aquaculture. Piwi-interacting RNAs (piRNAs) have been shown to function in germline or gonadal development. In this study, we performed small RNA deep sequencing and microarray hybridization to identify potential sturgeon piRNAs.

Methods

Male and female sturgeon gonads were collected and used for small RNA sequencing on an Illumina HiSeq platform with the validation of piRNA expression by microarray chip. The program Bowtie and k-mer scheme were performed to filter small RNA reads and discover potential sturgeon piRNAs. A known piRNA database, the coding sequence (CDS), 5′ and 3′ untranslated region (UTR) database of the A. Schrenckii transcriptome, Gene Ontology (GO) database and KEGG pathway database were searched subsequently to analyze the potential bio-function of sturgeon piRNAs.

Results

A total of 875,679 putative sturgeon piRNAs were obtained, including 93 homologous to known piRNAs and hundreds showing sex-specific and sex-biased expression. Further analysis showed that they are predominant in both the ovaries and testes and those with a sex-specific expression pattern are nearly equally distribution between sexes. This may imply a relevant role in sturgeon gonadal development. KEGG pathway and GO annotation analyses indicated that they may be related to sturgeon reproductive processes.

Conclusion

Our study provides the first insights into the gonadal piRNAs in a sturgeon species and should serve as a useful resource for further elucidation of the gene regulation involved in the sex differentiation of vertebrates. These results should also facilitate the technological development of early sex identification in sturgeon aquaculture.
Questões Identitárias: O Secretariado Executivo e as Atividades Tradutórias
Authors: Cantarotti Aline
Published: April 2019

Questões identitárias nos levam a refletir sobre o que significa ser tradutor para o secretariado executivo e o que significa também traduzir para esses profissionais, tema relevante para a formação. Considerando as línguas estrangeiras, corroboramos Rajagopalan (1998) quando ele problematiza uma ação errônea de linguístas os quais não se voltam para os falantes reais, com todas as hibridizações que possuem, com o atravessamento de diferentes perspectivas, culturas e contatos na constituição de uma sociedade. O pluralismo linguístico é um fenômeno social, assim como a constituição de comunidades linguisticamente pluralistas também é e o secretariado executivo se insere neste contexto. Tendo em vista que a globalização é contribuinte desse panorama e que a profissão do secretário executivo é globalizada, este estudo objetiva investigar e retratar a identidade do secretário executivo, na perspectiva dos alunos em formação, considerando atividades tradutórias em seu locus de trabalho. Para tanto, questionários foram aplicados aos alunos em um curso de secretariado executivo e suas respostas analisadas qualitativamente. Os futuros secretários percebem a necessidade de estudos na área de tradução e consideram que só poderão executar atividades tradutórias se forem expostos a esses conhecimentos e à sua prática ainda na graduação.
Towards Sustainability Through Incremental Innovation of a Low Cost Product: The Nespresso Case
Authors: Narazaki Rosana Yasue , Ruiz Mauro Silva , Kniess Cláudia Terezinha , Pedron Cristiane Drebes
Published: April 2019

With the increase of the population, it is imperative to expand the production of goods and services to meet the needs of individuals. Aggressive production practices are destroying and diminishing the world’s natural resources, without any consideration about its consequences and impact on future generations. In order to minimize this problem, organizations need to develop innovations, which focus on and address the economic, social and environmental dimensions, or Triple Bottom Line. This article presents a case study on Nespresso, and investigates their strategy of developing an innovative recyclable aluminum coffee capsule, and a closed-loop recycling process, with the purpose of meeting the Triple Bottom Line. Data collection was done through secondary data, video testimonies and public documents. The collected data was analyzed and validated using the Theoretical Framework of Sustainability. With the understanding of this case, it was sought to answer the following research question: How can a low-cost incremental innovation contribute to sustainability in a gourmet coffee company? The main finding is that a low-cost product with incremental innovation, designed to meet the purpose of the Triple Bottom Line and coupled with a value-sharing strategy, is capable of delivering economic, social, and environmental benefits.
Behaviour of Damaged B.F.I. Beam Repaired by CFRP Strips under Static or Fatigue Loads Using Finite Element Simulation
Authors: Refat Hala M. , Makhlouf Mohamed H.
Published: April 2019

This paper presents the numerical study to simulate the fatigue crack growth of artificially damaged steel Broad Flange I- beams section by single edge notched repaired with carbon fiber reinforced polymer CFRP strips. The study is carried out using ANSYS classic modeling approach is suggested to simulate the fatigue response of the beams, based on the cumulative damage theory and strain life method. Experimental test results were compared with FE results obtained. A parametric study was conducted using the validated model. The considered parameters were the number of CFRP strip layers used in the repair, the applied load range, initial crack length at time of strengthening and the thickness of CFRP strip. The numerical results indicated that the CFRP increased the critical crack length at which fracture occurred, and the strengthening was more effective at lower stress ranges. Moreover, the CFRP Strips can substantially delay failure and the results demonstrate the possibility of technique and highlight the importance of early intervention when repairing fatigue critical details. The ultimate load and ductility decreased substantially with increasing initial crack length at the time of installing the strengthening layer. Furthermore, increased capacity was achieved by increase the CFRP thickness and layers.
Factors of Increasing Benign Prostatic Hyperplasia in Saudi Arabia
Authors: Almaliki Abdullah
Published: April 2019

Benign  prostatic hyperplasia (BPH) is one of the conditions known as prostate growth that accompanied by the lower urinary tract symptoms. There are many researches that were conducted in Saudi Arabia in order to identify the most important factors that are working in increasing this disease. Most of the conducted studies have stated that there is a strong relation between age, metabolic syndrome, inflammation, hormonal alterations, and benign prostatic hyperplasia (BPH).

According to the researches, age and inflammation are playing the vital role as the main factors that cause the increasing cases of benign prostatic hyperplasia in the kingdom of Saudi Arabia. Data and results shown    in these studies demonstrate that ageing is the most significant risk factor for the development of BPH as 13% of men 40-49 of age versus 28% in subjects more than 70 year. It was also noticed that In ageing males, a significant tissue-remodeling process takes place within the prostate, especially in the transition zone. Another factors such as hormonal alternations and metabolic syndrome stated to be among the main factors of increasing the disease in the kingdom of Saudi Arabia.
Evaluation of Antioxidant, Anti-inflammatory and Analgesic Activities of Leaves of Saba senegalensis (A.DC) Pichon (Apocynaceae)
Authors: Belemlilga Mohamed Bonewendé , Traoré Tata Kady , Boly Gilchrist A. L. , Ouédraogo Noufou , Traoré Aristide , Lompo Marius , Ouédraogo Sylvin , Pierre Guissou Innocent
Published: April 2019

Aims: To evaluate antioxidant, anti-inflammatory and analgesic activities of extracts of Saba senegalensis leaves.

Study Design: In vitro antioxidant assay and in vivo anti-inflammatory, analgesic assay of Saba senegalensis extracts.

Place and Duration of Study: Saba senegalensis leaves, were collected in the Centre Region of Burkina Faso, in June–July 2015. The experiments were conducted at the department of Medicine and Traditional Pharmacopeia-Pharmacy (MEPHATRA-PH) of Institute of Research in Health Science (IRSS).

Methodology: The anti-oedematous tests with carrageenan and the analgesic with acetic acid and investigate effect on isolated organ were carried out. The standards were acetylsalicylic acid and paracetamol.

Results: After five hours of carrageenan-induced edema test, aqueous decoction (AD) presented better inhibition on all measure. In fact, at the different doses of 200 mg/kg, 400 mg/kg, and                600 mg/kg it presented percentages of inhibitions respectively of 30.81%, 62.27% and 72.71%. For the analgesic test, the hydroethanol macerate (HEM) showed a better pain reduction compared to the AD with a maximum effect of 77.28% at 400 mg/kg. Antioxidant activity with AD and his fractions shows that AD showed a better activity for the DPPH assay with an IC50 of 1.74 ±                0.10 μg/mL and a reducing power of 59.53 ± 2.16 mmol ET/g Sample. For HEM and his fractions, the ethyl acetate fraction (FHEM-AcOEt) showed a better IC50 of 0.18 ± 0.01 μg/mL for the DPPH test and dichloromethane fraction (FHEM-DCM) a reducing power agent of 88.88 ± 2.65 mmol ET/g Sample. All fractions were endowed with antioxidant properties by both methods.

Conclusion: The study findings suggest that the presence of phenolic and terpenoid compounds could explain the antioxidant, anti-inflammatory and analgesic properties of these extracts.
Effects of the Mixture of ‎ Cynara cardunculus var scolymus and Cinnamomum zeylanicum on Hepatic Enzymes Activity and Lipid Profiles in Patients with Non-alcoholic Fatty Liver Disease
Authors: Poor Razieh Yosef , Abdollahi Mohammad , Malekirad Ali Akbar , Movahednia Esmaeil , Mostafalou Sara , Sheybani Asl Zeynab
Published: April 2019

Objective: Nonalcoholic fatty liver disease (NAFLD) is rapidly going to be one of the most common metabolic diseases which can negatively affect the liver function and needs to be more explored within the context of new and efficient therapies. The aim of this study was to determine the benefit of ‎ Cynara cardunculus var scolymus and Cinnamomum zeylanicum mixture infusion (1.5 and 0.25 g/100 mL and twice/day) on patients with NAFLD.

Methods: The study was designed as a before-after clinical trial and performed on 20 patients having NAFLD. They were asked to use the mixture of extracts prepared in special bags twice a day for 30 days. Before and after using the mixture, Liver markers of NAFLD including alanin aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphates (ALP), cholesterol (chol), triglycerides (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) and also, fatty liver ultrasonograhic grading were measured.

Results: Treatment with mixture of extracts in patients with NAFLD resulted in a significant decrease in ALT, AST, and ALP. Also there was a significant improvement in lipid profile of the patients given by decreased TG, Chol, and LDL and increased HDL in serum. Moreover, a significant decrease in grade of sonographic examination was showed. No significant linear correlation was found between age, BMI and gender one way side and biochemical parameters and liver enzymes.

Conclusion: Taken together, it is concluded that the mixture of Cynara cardunculus var scolymus, Cinnamomum zeylanicum can have beneficial effects on hepatic function and lipid profiles of patients with NAFLD.
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

This 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

Despite 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

Next‐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

Wearable 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

Highly 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

Inorganic 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

An 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

A 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

The 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

Safety 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

Electrochemical 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

Mixed‐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

Ferrociphenols, 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

Over 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

Ground‐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.
Zum Entwerfen im Schalenbau: der neue Bistro‐Pavillon „Subway“ in Kelley Barracks, Stuttgart
Authors: Wilhelm Viktor , Brixner Robert
Published: April 2019

Die Verwendung von modularen Holzschaltischen ermöglicht die Wiederbelebung des Betonschalenbaus in Form von Faltwerken. Während einer „Stagnationsphase“ im Schalenbau haben sich jedoch die normativen bauphysikalischen und bautechnischen Anforderungen an die Betonbauten verändert. Am Beispiel der Dachschale des neuen „Subways“ innerhalb der „Kelley Barracks“ Stuttgart‐Möhringen werden im nachfolgenden Bericht die wesentlichen Aspekte des Entwerfens und Realisierens moderner Faltwerke angesprochen. In Zusammenhang mit der höheren Fertigungsfreundlichkeit ihrer Formen konnte unter Verwendung eines Faltwerks ein wirtschaftliches Ergebnis erzielt werden. Ihr Vorteil liegt des Weiteren in der einfachen Durchbildung von Temperaturstößen bzw. Temperaturblöcken. Nicht zuletzt haben die Autoren beim Entwurf der Dachschale die Einbaubarkeit von linearen thermischen Isokörben mitentwickelt.
Comparison of expression optimization of new derivative of staphylokinase (SAK‐2RGD‐TTI) with the rSAK
Authors: Faraji Habibollah , Ramezani Mohammad , Mashkani Baratali , Sadeghnia Hamid R. , Benhangi Hamid M. , Hosseini Teshnizi Saeed , Soltani Fatemeh
Published: April 2019

Staphylokinase (SAK) is a promising thrombolytic agent for the treatment of patients suffering from blood‐clotting disorders. To increase the potency of SAK and to minimize vessel reocclusion, a new construct bearing SAK motif fused to tsetse thrombin inhibitor (TTI) via a 20‐amino acid linker with 2 RGD (2 × arginine‐glycine‐aspartic acid inhibiting platelet aggregation via attachment to integrin receptors of platelet) was codon optimized and expressed comparatively in Pichia pastoris GS115 as a Mut+ strain and KM71H as a Muts strain. Fusion protein was optimized in terms of best expression condition and fibrinolytic activity and compared with the rSAK. Expression level of the designed construct reached up to 175 mg/L of the culture medium after 72‐hr stimulation with 2.5% methanol and remained steady for 3–4 days. The highest expression was obtained at the range of 2–3% methanol. The SAK‐2RGD‐TT (relative activity >82%) was more active at 25–37 °C than rSAK (relative activity of 93%). Further, it showed relative activity >80% at pH ranges of 7–9. Western blot analysis showed two bands of nearly 27 and 24 kDa at ratio of 5 to 3, respectively. The specific fibrinolytic activity of the SAK‐2RGD‐TTI was measured as 8,269 U/mg, and 19,616 U/mg for the nonpurified and purified proteins, respectively. Deglycosylation by using tunicamycin in culture medium resulted in higher fibrinolytic activity of SAK‐2RGD‐TTI (2.2 fold). Consequently, compared to the rSAK, at the same equimolar proportion, addition of RGD and TTI fragments could increase fibrinolytic activity. Also, P. pastoris can be considered as an efficient host for overexpression of the soluble SAK‐2RGD‐TTI with high activity without requiring a complicated purification procedure.
Recent Chemical Approaches for Site‐Specific Conjugation of Native Antibodies: Technologies toward Next‐Generation Antibody–Drug Conjugates
Authors: Yamada Kei , Ito Yuji
Published: April 2019

Antibody–drug conjugates (ADCs), which consist of three components, antibody, linker, and payload, can function as “magic bullets”. These conjugates offer the ability to target drug delivery to specific cells, based on cell‐specific recognition and the binding of an antigen by a monoclonal antibody (mAb). In particular, by delivering a cytotoxic payload to cancer cells, ADCs are expected to provide a breakthrough in oncology treatments by providing a way to increase efficacy and decrease toxicity, in comparison with traditional chemotherapeutic treatments. The development of ADC therapeutics has dramatically progressed in the past decade and two ADCs have been approved and used as anticancer drugs in the clinic. However, several critical issues regarding the performance of ADCs are still being discussed and investigated. Indeed, in the past few years, several groups have reported that, changing the number and position of the drug payloads in the ADCs, affects the pharmacokinetics, drug release rates, and biological activity. The use of conventional heterogeneous conjugation methods for ADC preparation results in the drug/antibody ratio and connecting position of the payload having stochastic distributions. Therefore, it is important to investigate how these potential problems can be circumvented through site‐specific conjugation. Herein, various site‐specific chemical conjugation strategies with native mAbs that are currently used for the production of ADCs, including residue‐selective labeling for generating ADCs, disulfide rebridging, and affinity‐peptide‐mediated site‐specific chemical conjugation technologies, are reviewed and described.
Chrysophanol attenuated isoproterenol‐induced cardiac hypertrophy by inhibiting Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway
Authors: Yuan Jing , Hong Huiqi , Zhang Yuhong , Lu Jing , Yu Youhui , Bi Xueying , Wang Junjian , Ye Jiantao
Published: April 2019

Cardiac hypertrophy is a common pathological change found in various cardiovascular diseases. Although it has long been recognized as an important risk factor responsible for heart failure, there is still a lack of effective treatments in clinic. Chrysophanol is a natural compound with multiple biological activities and protective roles in the cardiovascular system. However, its potential effect on cardiac hypertrophy remains unclear. In the current study, we found that chrysophanol could protect against isoproterenol (ISO)‐induced cardiac hypertrophy both in vitro and in vivo. Increase of cell surface and hypertrophic marker expression induced by ISO in neonatal rat cardiomyocytes was downregulated by chrysophanol. Moreover, chrysophanol ameliorated the abnormal changes of cardiac structure and function in rats subjected to ISO injection, as shown by echocardiography and morphometry measurements. Further mechanistical investigation demonstrated that chrysophanol inhibited phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) induced by ISO. Nuclear translocation of STAT3 and transcription of downstream genes promoted by ISO treatment were also remarkably suppressed by chrysophanol. Taken together, our findings revealed that chrysophanol attenuated ISO‐induced cardiac hypertrophy by inhibiting JAK2/STAT3 signaling pathway. Chrysophanol may be a potential candidate compound for the prevention and treatment of hypertrophy‐related cardiomyopathy.
Neurodegeneration, demyelination, and astrogliosis in rat spinal cord by chronic lead treatment
Authors: Villa‐Cedillo Sheila Adela , Nava‐Hernández Martha Patricia , Soto‐Domínguez Adolfo , Hernández‐Ibarra José Anselmo , Perez‐Trujillo José Juan , Saucedo‐Cárdenas Odila
Published: April 2019

Early exposure to lead (Pb) has been associated with an elevated risk of developing neurodegenerative diseases. There is evidence that neuronal damage in chronic Pb exposure can be caused by the convergence of glial damage. Apoptosis may be a possible mechanism of Pb‐induced cell death in the central nervous system. We tested cellular damage and apoptosis in the spinal cord of Wistar rats treated with Pb. Twelve rats were divided into two groups (n = 6): the control group was treated with only drinking water and the other group received 500 ppm of Pb acetate. After 3 months of Pb treatment, all animals were euthanized and spinal cords were extracted. Morphology was evaluated by Nissl and Kluver‐Barrera stainings. Apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Specific antibodies were used to evaluate Pb damage in oligodendrocytes, astrocytes, and microglia. A large number of apoptotic bodies was observed in the white matter of the Pb‐treated group. The Pb‐treated group also showed a reduced number of neurons and oligodendrocytes but had an increased number of astrocytes compared with the nontreated group. Our results demonstrate that chronic Pb treatment induces neurodegeneration, demyelination, and astrogliosis in the rat spinal cord.
Velocity and attenuation analysis methods for characterizing the properties of wheat flour noodle dough
Authors: Strybulevych Anatoliy , Diep Sally , Daugelaite Daiva , Guillermic Reine‐Marie , Page John H. , Hatcher David W. , Scanlon Martin G.
Published: April 2019

Background and objectives

Noodles are a traditional staple of the Asian diet, and ensuring quality during production is important for both producers and consumers. Ultrasound is sensitive to the mechanical properties of dough that relate to product texture and is therefore a promising quality assessment tool. For optimal results, it is important to assess the merits of different ultrasonic analysis methods.

Findings

Mechanical properties of raw Asian noodle dough made from two red spring wheat varieties were measured by a low‐frequency ultrasonic transmission technique. Entire transmitted ultrasonic pulses, having passed through disks of the noodle dough, were analyzed using fast Fourier transform (FFT) techniques, enabling the transmitted phase and amplitude as a function of frequency to be compared for samples of different thickness. This approach allows noodles made from different wheat varieties to be discriminated through ultrasonic velocity and attenuation measurements.

Conclusions

The frequency dependence of both velocity and attenuation coefficient, which was revealed the FFT method, points to the presence of gas bubbles, which even in small amounts can influence texture and hence noodle quality.

Significance and novelty

In addition to providing insights on properties that influence noodle quality, the frequency dependence of velocity and attenuation found by the FFT analysis can explain differences reported by different analysis techniques.
Black Current: Structure, Characterization, and Optoelectronic Properties of Ce3Cl3[MoO6]
Authors: Dorn Katharina V. , Blaschkowski Björn , Bamberger Heiko , van Slageren Joris , Doll Klaus , Claus Ralf , Matsumoto Yosuke , Takagi Hidenori , Hartenbach Ingo
Published: April 2019

The admixture of CeO2, Ce, CeCl3, and MoO3 with an excess of LiCl as flux in evacuated silica ampules leads to large black single crystals as well as a black microcrystalline powder of Ce3Cl3[MoO6] after tempering at 850 °C for three days. The title compound crystallizes in the hexagonal space group P63/m (a=934.93(4), c=538.86(2) pm) with two formula units per unit cell. The crystal structure consists of rather unusual trigonal‐prismatic [MoO6]6− units besides Ce3+ ions in a tetra‐capped trigonal‐prismatic coordination, formed by four Cl− and six O2− ions. The black color is related to an optical band gap of 1.35(2) eV, which was determined by diffuse reflectance spectroscopy and confirmed by theoretical calculations. The low band gap between the 4f1 state of cerium (HOMO) and the 5d0 state of molybdenum (LUMO) gave rise to the idea of electronic excitation between these two states by IR irradiation, creating a drop in the resistivity of the material, which was detected by appropriate measurements.
One‐Pot Sequential Kumada–Tamao–Corriu Couplings of (Hetero)Aryl Polyhalides in the Presence of Grignard‐Sensitive Functional Groups Using Pd‐PEPPSI‐IPentCl
Authors: Sinha Narayan , Champagne Pier Alexandre , Rodriguez Michael J. , Lu Yu , Kopach Michael E. , Mitchell David , Organ Michael G.
Published: April 2019

We report a general and rapid chemoselective Kumada–Tamao–Corriu (KTC) cross‐coupling of aryl bromides in the presence of chlorides or triflates with functionalized Grignard reagents at 0 °C in 15 min by using Pd‐PEPPSI‐IPentCl (C4). Nucleophiles and electrophiles (or both) can contain Grignard‐sensitive functional groups (‐CN, ‐COOR, etc.). Control experiments together with DFT calculations suggest that transmetallation is rate limiting for the selective cross‐coupling of Br in the presence of Cl/OTf with functionalized Grignard reagents. One‐pot sequential KTC/KTC cross‐couplings with bromo–chloro arenes have been demonstrated for the first time. We also report the one‐pot sequential KTC/Negishi cross‐couplings using C4 showcasing the versatility of this methodology.