bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital transfrmation model of education processes through cloud services
Authors: Stefanović Nenad , Plašić Jelena
Published: February 2021

Education in the 21st century is confronted with many challenges - it needs to be personalized, adaptive to user needs, collaborative, social, multimedial, and technologically supported. The development of information technologies such as cloud computing, mobile technologies, platforms for social networking and collaboration, and intelligent systems, has created enormous opportunities for improvement of the education processes. In order to ensure required quality level, educational institutions are forced to enter the digital transformation process. In this paper, the analysis of the existing state of the education system and overview of the existing results in the digital transformation are given. Process model for digital transformation of education that encompasses the entire lifecycle, as well as the framework for implementation of cloud digital services with basic phases and steps is presented. The concrete use cases of application of the digital services in teaching and learning are shown. The results obtained show efficiency and effectiveness of the proposed process model and the framework, as well as the cloud-based digital platform. The main benefits include a higher satisfaction level of students and teachers, better exam results, more intensive collaboration and communication, knowledge exchange, lower costs, as well as a better reliability and security of the system. Service for monitoring and data analysis enable more efficient decision making and taking actions for improvements.
TG2 Innovative and Resilient Regions : Roadshow report
Authors: Teräs Jukka , Cuadrado Alex , Wøien Meijer Mari , Giacometti Alberto
Published: February 2021

This document reports on the Nordic TG2 Roadshow, which was commissioned by the Nordic Thematic Group for Innovative and Resilient Regions. The Nordic Thematic Group for Innovative and Resilient Regions 2017–2020 (TG2) was established by the Nordic Council of Ministers as a part of the Nordic Co-operation Programme for Regional Development and Planning 2017–2020. The TG2 group was organised under the Nordic Council of Ministers’ Committee of Civil Servants for Regional Affairs, and Nordregio has acted as Secretariat for the thematic groups.
Modelling and Forecasting Volatility on Electric Power Exchange SEEPEX
Authors: Terzić Ivica , Jeremić Zoran , Latas Tatjana
Published: February 2021

Research Question: The launch and the beginning of trade on the South East Electric Power Exchange (SEEPEX) in Belgrade, early in 2016, opened the issue of forecasting volatility and price movements in the market. Motivation: The issue is of vital importance for all market actors for the purpose of maximising profits, reducing risks, planning production and making investment decisions. Forecasting volatility and price movements in electric power markets is important for traders with profit maximisation and yield-to-risk ratio optimisation in mind and, equally, for producers, large industrial consumers, investors and portfolio managers. Idea: Exploring models and techniques to forecast volatility in electricity markets and subsequently testing statistical methods based on time series data, the ARMA-GARCH being the preferred model, with a view to identifying optimal methods for this market. The volatility of the power market and price movements have been tested during a given period. The results can be used to gauge market parameters and opportunities to extrapolate future volatility and movements in electricity prices. Data: For the purposes of this analysis, a time series involving price movements and trade volumes were used, covering a period between the SEEPEX trade launch and the end of 2019. Tools: In the empirical part of the paper, "Stata 13" statistical and econometric software was used to explore stylised facts and model the volatility of SEEPEX electricity price returns. Findings: The authors offer an overview of different methods used in the research, having selected different specifications of the ARMA-GARCH model as the most reliable in predicting volatility in the given market. The exponential GARCH model with student-t error distribution is believed to have provided the best overall performance in modelling the SEEPEX return volatility, as well as the best volatility forecast. Contribution: This is one of the first empirical studies of the Serbian power market that deals with risk modelling. Forecasting time-varying electricity exchange volatility is important for all market participants interested in variance forecasts to be used to calculate risk and hedging measures.
Evaluation of Rust code verbosity, understandability and complexity
Authors: Ardito Luca , Barbato Luca , Coppola Riccardo , Valsesia Michele
Published: February 2021

Rust is an innovative programming language initially implemented by Mozilla, developed to ensure high performance, reliability, and productivity. The final purpose of this study consists of applying a set of common static software metrics to programs written in Rust to assess the verbosity, understandability, organization, complexity, and maintainability of the language. To that extent, nine different implementations of algorithms available in different languages were selected. We computed a set of metrics for Rust, comparing them with the ones obtained from C and a set of object-oriented languages: C++, Python, JavaScript, TypeScript. To parse the software artifacts and compute the metrics, it was leveraged a tool called rust-code-analysis that was extended with a software module, written in Python, with the aim of uniforming and comparing the results. The Rust code had an average verbosity in terms of the raw size of the code. It exposed the most structured source organization in terms of the number of methods. Rust code had a better Cyclomatic Complexity, Halstead Metrics, and Maintainability Indexes than C and C++ but performed worse than the other considered object-oriented languages. Lastly, the Rust code exhibited the lowest COGNITIVE complexity of all languages. The collected measures prove that the Rust language has average complexity and maintainability compared to a set of popular languages. It is more easily maintainable and less complex than the C and C++ languages, which can be considered syntactically similar. These results, paired with the memory safety and safe concurrency characteristics of the language, can encourage wider adoption of the language of Rust in substitution of the C language in both the open-source and industrial environments.
DisCoVering potential candidates of RNAi-based therapy for COVID-19 using computational methods
Authors: Rohani Narjes , Ahmadi Moughari Fatemeh , Eslahchi Changiz
Published: February 2021

The ongoing pandemic of a novel coronavirus (SARS-CoV-2) leads to international concern; thus, emergency interventions need to be taken. Due to the time-consuming experimental methods for proposing useful treatments, computational approaches facilitate investigating thousands of alternatives simultaneously and narrow down the cases for experimental validation. Herein, we conducted four independent analyses for RNA interference (RNAi)-based therapy with computational and bioinformatic methods. The aim is to target the evolutionarily conserved regions in the SARS-CoV-2 genome in order to down-regulate or silence its RNA. miRNAs are denoted to play an important role in the resistance of some species to viral infections. A comprehensive analysis of the miRNAs available in the body of humans, as well as the miRNAs in bats and many other species, were done to find efficient candidates with low side effects in the human body. Moreover, the evolutionarily conserved regions in the SARS-CoV-2 genome were considered for designing novel significant siRNA that are target-specific. A small set of miRNAs and five siRNAs were suggested as the possible efficient candidates with a high affinity to the SARS-CoV-2 genome and low side effects. The suggested candidates are promising therapeutics for the experimental evaluations and may speed up the procedure of treatment design. Materials and implementations are available at:https://github.com/nrohani/SARS-CoV-2.
High prevalence of circulating DS-1-like human rotavirus A and genotype diversity in children with acute gastroenteritis in Thailand from 2016 to 2019
Authors: Pasittungkul Siripat , Lestari Fajar Budi , Puenpa Jiratchaya , Chuchaona Watchaporn , Posuwan Nawarat , Chansaenroj Jira , Mauleekoonphairoj John , Sudhinaraset Natthinee , Wanlapakorn Nasamon , Poovorawan Yong
Published: February 2021

Background

Human rotavirus A (RVA) infection is the primary cause of acute gastroenteritis (AGE) in infants and young children worldwide, especially in children under 5 years of age and is a major public health problem causing severe diarrhea in children in Thailand. This study aimed to investigate the prevalence, genotype diversity, and molecular characterization of rotavirus infection circulating in children under 15 years of age diagnosed with AGE in Thailand from January 2016 to December 2019.

Methods

A total of 2,001 stool samples were collected from children with gastroenteritis (neonates to children <15 years of age) and tested for RVA by real-time polymerase chain reaction (RT-PCR). Amplified products were sequenced and submitted to an online genotyping tool for analysis.

Results

Overall, 301 (15.0%) stool samples were positive for RVA. RVA occurred most frequently among children aged 0-24 months. The seasonal incidence of rotavirus infection occurred typically in Thailand during the winter months (December-March). The G3P[8] genotype was identified as the most prevalent genotype (33.2%, 100/301), followed by G8P[8] (10.6%, 32/301), G9P[8] (6.3%, 19/301), G2P[4] (6.0%, 18/301), and G1P[6] (5.3%, 16/301). Uncommon G and P combinations such as G9P[4], G2P[8], G3P[4] and G3P[9] were also detected at low frequencies. In terms of genetic backbone, the unusual DS-1-like G3P[8] was the most frequently detected (28.2%, 85/301), and the phylogenetic analysis demonstrated high nucleotide identity with unusual DS-1-like G3P[8] detected in Thailand and several countries.

Conclusions

A genetic association between RVA isolates from Thailand and other countries ought to be investigated given the local and global dissemination of rotavirus as it is crucial for controlling viral gastroenteritis, and implications for the national vaccination programs.
Critical Review III to Standardize the Textbooks of Fundamentals of Nursing: Nutrition, Urinary and Bowel Elimination Needs
Authors: Yu Sun-Mi , Choi Dongwon , Jeong Hye Sun , Sohng Kyeong-Yae
Published: February 2021

Purpose: To identify the discrepancies in the textbook of fundamentals of nursing in nutrition and elimination needs in terms of number, range, definition and etc.Methods: The 10 textbooks which are the most frequently used were selected and reviewed. After then compared it with the protocols of essential nursing skills of Korean Accreditation Board of Nursing Education and evidence-based clinical nursing practice guidelines of Korean Hospital Nurses’ Association.Results: The most significant discrepancies in nutrition domain were criteria of obesity, confirmation of nasogastric tube placement. In elimination domain, there were several mixed or miss uses of French and number unit in catheter size. And appropriate catheter size for urinary catheterization and enema is different to books and guidelines.Conclusion: In order to conduct an effective resource in education of nursing, textbooks need to be revised constantly and contain the recent researches and guidelines.
Factors Influencing Career Preparation Behavior of Mature Age Student Nurses
Authors: Lim Jong Mi , Cho Ok-Hee
Published: February 2021

Purpose: This study was done to determine the correlations among grit, social support, career barriers, and career preparation behavior in mature age nursing students, and identify factors influencing their career preparation behavior.Methods: This cross-sectional, descriptive study included 106 undergraduate nursing students aged 25 years or older at the time of entering three universities in Korea. Grit, social support, career barriers, and career preparation behavior were investigated using structured questionnaires. Data analyses included descriptive statistics, independent t-test, one-way ANOVA, Pearson’s correlation analysis, and stepwise multiple regression analysis and were performed with the SAS program (version 9.4).Results: The factors influencing career preparation behavior of mature age nursing students included: persistence of efforts (β=.35, p<.001) and consistency of interests (β=-.21, p=.011) under the sub-domains of grit; informational support (β=.29, p<.001) under the sub-domains of social support; lack of job information (β=-.36, p<.001) and anxiety about the future(β=.28, p=.008) under the sub-domains of career barriers. These variables accounted for approximately 42% of the variance in career preparation behavior.Conclusion: The findings imply that in order to improve the career preparation behavior and lower the career barriers of mature age nursing students, their individual cognitive and psychological characteristics should be considered while providing diverse job information as part of career guidance.
Effects of Strategic Determinants on Implementation of County Annual Development Plans among County Governments in Kenya. A Case of Selected Kenyan Counties
Authors: Abdi Ali Hassan , Mbithi Mary , Kithinji Moses
Published: February 2021

Kenya devolved governance, which is in massive transition, has devoted substantial efforts in developing strategic county annual development plans. However, the county governments are paying less attention on implementation of these viable plans. Despite a considerable research on implementation of strategic plans, the Kenya county government lack substantial empirical literature to guide in establishing strategic determinants informing implementation their plans among Kenya counties. So immediate analysis was appropriate for assessing these strategic determinants, hence this study. This study used descriptive survey research design with it is target population being the 531 officers actively involved in implementation of county annual development plans and particularly; county executive officers, administrators, and members of county assemblies from Kajiado Kiambu, Machakos and Nairobi counties. A sample size of 228 respondents was determined using Yamane formula; who were selected using stratified proportionate random sampling. The data was collected using questionnaire pre-tested for reliability and validity. Quantitative technique was exploited to yield descriptive statistics while ordinal logistics regressions was employed in assessing the relationships between strategic determinants and plans’ implementation. The study concludes that at 0.05 level of significance, there is a statistically significant effect of each of; strategic leadership characteristics, organizational resources, organizational culture and organizational structure on implementation of county annual development plans among County Governments in Kenya. The study recommends for the counties to review strategic leadership policies manage their organizational resources effectively, rethink their organizational cultures, and energise their organizational structures.
Assesment of Biochemical Forage Quality of Sweet Sorghum [Sorghum bicolor (L.) Moench ssp. saccharatum]
Authors: Oktem Abdullah , Yucel Celal , Oktem Ayse Gulgun
Published: February 2021

In this study, it was aimed to determine some forage quality characteristics of sweet sorghum genotypes in semi-arid climatic conditions. The experiment was set up in randomized complete block design with 4 replicates. Research was carried out in 2016 and 2017 under Harran Plain second crop conditions, Sanliurfa, Turkey. In the study 21 genotypes of sweet sorghum were used. Crude protein content, crude ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), dry matter digestibility, dry matter consumption, were determined in the study. Significant differences were found between the genotypes for tested characteristics (P≤0.01). According to average of two years, crude protein content ranged from 4.20% (Tracy) to 5.90% (USDA S.Africa), crude ash from 4.44% (Theis) to 6.90% (Topper 76), acid detergent fiber (ADF) from 27.84% (Nebraska sugar) to 36.30% (USDA-Zaire). The highest NDF value was obtained from USDA-Zaire genotype (56.49%) whereas the lowest values were seen at N98 genotype (43.11%). Dry matter digestibility values were between 60.62% (USDA-Zaire) and 67.21% (Nebraska sugar), dry matter consumption between 2.14% and 2.85%. The highest relative feed value was obtained from N98 genotype (148.95) whereas the lowest values were seen at USDA-Zaire genotype (101.00). Net energy values ranged from 1.38 Mcal kg-1 (USDA-Zaire) to 1.50 Mcal kg-1 (Nebraska sugar). Considering the properties examined in terms of feed quality, it was seen that the crude protein content and net energy value was low. But ADF, NDF, digestible dry matter, dry matter consumption and relative feed values were within acceptable levels. Nebraska sugar, Topper 76, N98, Roma, M81E, Tracy and Corina genotypes were found as the best for forage quality in sweet sorghum. It was determined that sweet sorghum can be used as a forage source.
Energy‐efficient operation of indirect adiabatic data center cooling systems via Newton‐like phasor extremum seeking control
Authors: Lionello Michele , Lucchese Riccardo , Rampazzo Mirco , Guay Martin , Atta Khalid
Published: February 2021

This paper considers the problem of optimizing the operation of Indirect Adiabatic Cooling (IAC) systems with application to data centers. Optimal operation is achieved when the required cooling demand is satisfied at the minimum energy cost. For this purpose, we design a supervisory control system, where the higher layer determines the optimal set‐points for the local controllers by employing an Extremum Seeking Control (ESC) scheme. In particular, we consider a Newton‐like phasor ESC, which augments the derivative estimator underlying the phasor approach to capture also the Hessian of the plant index and then it uses these estimates to steer the system along a Newton‐like direction. The effectiveness of the considered approach is tested in simulation by exploiting a Matlab‐based simulation environment including an IAC system and a computer room.
3D Printing of n‐Al/Polytetrafluoroethylene‐Based Energy Composites with Excellent Combustion Stability
Authors: Zheng Dawei , Huang Tianwei , Xu Bing , Zhou Xu , Mao Yaofeng , Zhong Lin , Gao Bing , Wang Dunju
Published: February 2021

The development of 3D printing technology provides a new idea for the application of energy‐containing materials as functional reactive materials, which helps Al–F high‐energy materials to achieve customized performance and structure, so that energy transmit can be targeted. A high fuel‐load ink (up to 90 wt%) based on Al‐polytetrafluoroethylene (PTFE) is designed and fabricated using fluororubber (FR) as a binder. The content of FR is directly related to the mechanical properties of ink, and the customized structure from the uniform and stable deposition can be obtained by adjusting the content of FR (10–20 wt%). Under the display of high‐speed photography, the ink shows a strong stability in combustion performance, which is conducive to realize the performance customization of the ink in the application. To better understand the combustion mechanism, the thermal properties and combustion process are analyzed in brief through thermal analysis and the combustion snapshots.
Kinetic Control of Long‐Range Cationic Ordering in the Synthesis of Layered Ni‐Rich Oxides
Authors: Wang Suning , Hua Weibo , Missyul Alexander , Darma Mariyam Susana Dewi , Tayal Akhil , Indris Sylvio , Ehrenberg Helmut , Liu Laijun , Knapp Michael
Published: February 2021

Deciphering the sophisticated interplay between thermodynamics and kinetics of high‐temperature lithiation reaction is fundamentally significant for designing and preparing cathode materials. Here, the formation pathway of Ni‐rich layered ordered LiNi0.6Co0.2Mn0.2O2 (O‐LNCM622O) is carefully characterized using in situ synchrotron radiation diffraction. A fast nonequilibrium phase transition from the reactants to a metastable disordered Li1−x(Ni0.6Co0.2Mn0.2)1+xO2 (D‐LNCM622O, 0 < x < 0.95) takes place while lithium/oxygen is incorporated during heating before the generation of the equilibrium phase (O‐LNCM622O). The time evolution of the lattice parameters for layered nonstoichiometric D‐LNCM622O is well‐fitted to a model of first‐order disorder‐to‐order transition. The long‐range cation disordering parameter, Li/TM (TM = Ni, Co, Mn) ion exchange, decreases exponentially and finally reaches a steady‐state as a function of heating time at selected temperatures. The dominant kinetic pathways revealed here will be instrumental in achieving high‐performance cathode materials. Importantly, the O‐LNCM622O tends to form the D‐LNCM622O with Li/O loss above 850 °C. In situ XRD results exhibit that the long‐range cationic (dis)ordering in the Ni‐rich cathodes could affect the structural evolution during cycling and thus their electrochemical properties. These insights may open a new avenue for the kinetic control of the synthesis of advanced electrode materials.
New Insight into Microstructure Engineering of Ni‐Rich Layered Oxide Cathode for High Performance Lithium Ion Batteries
Authors: Jung Chul‐Ho , Kim Do‐Hoon , Eum Donggun , Kim Kyeong‐Ho , Choi Jonghyun , Lee Jongwon , Kim Hyung‐Ho , Kang Kisuk , Hong Seong‐Hyeon
Published: February 2021

Ni‐rich layered LiNixCoyMn1−x−yO2 (LNCM) with Ni content over >90% is considered as a promising lithium ion battery (LIB) cathode, attributed by its low cost and high practical capacity. However, Ni‐rich LNCM inevitably suffers rapid capacity fading at a high state of charge due to the mechanochemical breakdown; in particular, the microcrack formation has been regarded as one of the main culprits for Ni‐rich layered cathode failure. To address these issues, Ni‐rich layered cathodes with a textured microstructure are developed by phosphorous and boron doping. Attributed by the textured morphology, both phosphorous‐ and boron‐doped cathodes suppress microcrack formation and show enhanced cycle stability compared to the undoped cathode. However, there exists a meaningful capacity retention difference between the doped cathodes. By adapting the various analysis techniques, it is shown that the boron‐doped Ni‐rich layered cathode displays better cycle stability not only by its ability to suppress microcracks during cycling but also by its primary particle morphology that is reluctant to oxygen evolution. The present work reveals that not only restraint of particle cracks but also suppression of oxygen release by developing the oxygen stable facets is important for further improvements in state‐of‐the‐art Li ion battery Ni‐rich layered cathode materials.
Using Preformed Meisenheimer Complexes as Dopants for n‐Type Organic Thermoelectrics with High Seebeck Coefficients and Power Factors
Authors: Han Jinfeng , Ganley Connor , Hu Qin , Zhao Xingang , Clancy Paulette , Russell Thomas P. , Katz Howard E.
Published: February 2021

A pre‐formed Meisenheimer complex of a naphthalenediimide (NDI) with tetrabutylammonium fluoride (TBAF) is obtained in a simple way by mixing dibrominated 4,9‐dibromo‐2,7‐bis(2‐octyldodecyl)benzo[lmn][3,8]phenanthroline‐1,3,6,8(2H,7H)‐tetraone and TBAF in solution and used as a dopant for n‐type organic thermoelectrics. Two n‐type polymers PNDIClTVT and PBDOPVTT are synthesized, n‐doped, and characterized as conductive and thermoelectric materials. PNDIClTVT doped with NDI‐TBAF presents a high σ value of 0.20 S cm–1, a Seebeck coefficient (S) of −1854 µV K–1, and a power factor (PF) of 67 µW m–1 K–2, among the highest reported PF in solution‐processed conjugated n‐type polymer thermoelectrics. Using 4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzoimidazol‐2‐yl)phenyl)dimethylamine and NDI‐TBAF as co‐dopants, PNDIClTVT has a PF > 35 µW m–1 K–2; while for PBDOPVTT σ = 0.75 S cm–1 and PF = 58 µW m–1 K–2. In this study it is found that an ionic adduct together with a neutral dopant improves the performance of n‐type organic thermoelectrics leading to an enhanced power factor, and more generally, the role of such an adduct in polymer doping is also elucidated.
Pulverizing Fe2O3 Nanoparticles for Developing Fe3C/N‐Codoped Carbon Nanoboxes with Multiple Polysulfide Anchoring and Converting Activity in Li‐S Batteries
Authors: Zhou Changyu , Li Xiangcun , Jiang Helong , Ding Yu , He Gaohong , Guo Jiao , Chu Zhong , Yu Guihua
Published: February 2021

Sluggish redox kinetics, shuttle effect, poor conductivity, and large volume change of sulfur limit the practical applications of lithium‐sulfur batteries. Hollow, porous, and necklace‐like Fe3C/N‐codoped carbon nanoboxes (Fe3C/NC) connected by N‐doped carbon (NC) nanofibers are designed by pulverizing Fe2O3 embedded in polyacrylonitrile (PAN) fibers to produce multifunctional sulfur hosts, which exhibit multiple polysulfide anchoring and catalytic conversion activities. Experimental and first‐principles density functional theory studies reveal that the uniformly distributed Fe3C and N units in the nanoboxes can significantly suppress the polysulfide shuttle effect. The conversion of polysulfides (LiPSs) to Li2S is catalyzed during discharge. The process relies on the fast electron transfer through the NC nanofibers and facilitated Li+ diffusion through the porous nanobox shells. The structural characteristics (“boxes in fibers”) of the nanoboxes influence the high sulfur loading and tolerance of volume variation of LiPSs, resulting in the synergistic catalysis of the redox reactions. A high capacity of 645 mAh g−1 after 240 cycles at 1 C, a high capacity of 712 mAh g−1 at a high sulfur loading of 5 mg cm−2 after 100 cycles at 0.2 C, and an enhanced areal capacity of 3.6 mAh cm−2 are demonstrated.
Ultra‐Compliant and Tough Thermochromic Polymer for Self‐Regulated Smart Windows
Authors: Zhang Qiuhong , Jiang Yuanwen , Chen Litong , Chen Wei , Li Jinxing , Cai Yifeng , Ma Chaoqun , Xu Wenhui , Lu Yanqing , Jia Xudong , Bao Zhenan
Published: February 2021

Smart windows have shown powerful potential in modulating sunlight and energy management. However, there has not been a single system that can simultaneously possess all desired properties, that is, high compliance, wide tunability, and autonomous regulation. Here, a novel system based on polyhedral oligomeric silsesquioxane crosslinked poloxamer is demonstrated. The as‐synthesized material simultaneously possesses a number of the desired properties for smart windows. In addition, with the incorporation of gold nanorods, the as‐fabricated smart window can be operated in an autonomous fashion with its transmission being modulated automatically upon environmental temperature shifts. Finally, the high toughness and high stretchability (10 000% strain) of the material also pave a way for future applications in wearable displays or flexible window screens.
A Flash‐Induced Robust Cu Electrode on Glass Substrates and Its Application for Thin‐Film μLEDs
Authors: Shin Jung Ho , Park Jung Hwan , Seo Jeongmin , Im Tae Hong , Kim Jong Chan , Lee Han Eol , Kim Do Hyun , Woo Kie Young , Jeong Hu Young , Cho Yong‐Hoon , Kim Taek‐Soo , Kang Il‐Suk , Lee Keon Jae
Published: February 2021

A robust Cu conductor on a glass substrate for thin‐film μLEDs using the flash‐induced chemical/physical interlocking between Cu and glass is reported. During millisecond light irradiation, CuO nanoparticles (NPs) on the display substrate are transformed into a conductive Cu film by reduction and sintering. At the same time, intensive heating at the boundary of CuO NPs and glass chemically induces the formation of an ultrathin Cu2O interlayer within the Cu/glass interface for strong adhesion. Cu nanointerlocking occurs by transient glass softening and interface fluctuation to increase the contact area. Owing to these flash‐induced interfacial interactions, the flash‐activated Cu electrode exhibits an adhesion energy of 10 J m−2, which is five times higher than that of vacuum‐deposited Cu. An AlGaInP thin‐film vertical μLED (VLED) forms an electrical interconnection with the flash‐induced Cu electrode via an ACF bonding process, resulting in a high optical power density of 41 mW mm−2. The Cu conductor enables reliable VLED operation regardless of harsh thermal stress and moisture infiltration under a high‐temperature storage test, temperature humidity test, and thermal shock test. 50 × 50 VLED arrays transferred onto the flash‐induced robust Cu electrode show high illumination yield and uniform distribution of forward voltage, peak wavelength, and device temperature.
Degradable Poly(vinyl alcohol)‐Based Supramolecular Plastics with High Mechanical Strength in a Watery Environment
Authors: Li Yixuan , Li Siheng , Sun Junqi
Published: February 2021

It is challenging to fabricate degradable poly(vinyl alcohol) (PVA)‐based plastics that can be used in watery environments because PVA is soluble in water. In this study, PVA‐based supramolecular plastics with excellent degradability in soil and high mechanical strength in watery environments are fabricated by the complexation of vanillin‐grafted PVA (VPVA), hydrophobic humic acid (HA), and Fe3+ ions (hereafter denoted as VPVA–HA–Fe complexes). Large‐area PVA‐based plastics can be easily prepared from a solution of VPVA–HA–Fe complexes using a blade‐coating method. The high‐density of hydrogen bonds and coordination interactions, as well as the reinforcement of self‐assembled Fe3+‐chelated HA nanoparticles, facilitate the fabrication of PVA‐based plastics with a breaking strength of ≈85.0 MPa. After immersion in water at room temperature for 7 d, the PVA‐based plastics exhibit a breaking strength of ≈26.2 MPa, which is similar to that of polyethylene in its dry state. Furthermore, owing to the reversibility of the hydrogen bonds and coordination interactions, the VPVA–HA–Fe plastics are recyclable and can be conveniently processed into plastic products with desired shapes. After being placed under soil for ≈108 d, the PVA‐based plastics are completely degraded into nontoxic species without requiring manual interference.
Trap Energy Upconversion‐Like Near‐Infrared to Near‐Infrared Light Rejuvenateable Persistent Luminescence
Authors: Chen Xingzhong , Li Yang , Huang Kai , Huang Ling , Tian Xiumei , Dong Huafeng , Kang Ru , Hu Yihua , Nie Jianmin , Qiu Jianrong , Han Gang
Published: February 2021

Persistent‐luminescence phosphors (PLPs) have a wide variety of applications in the fields of photonics and biophotonics due to their ultralong afterglow lifetime. However, the existing PLPs are charged and recharged with short‐wavelength high‐energy photons or inconvenient and potentially risky X‐ray beams. To date, deep tissue penetrable NIR light has mainly been used for photostimulated afterglow emission, which continues to decay and weaken after each cycle, Herein, a new paradigm of trap energy upconversion‐like near‐infrared (NIR) to near‐infrared light rejuvenateable persistent luminescence in bismuth‐doped calcium stannate phosphors and nanoparticles is reported. In contrast to the existing PLPs and persistent‐luminescence nanoparticles, the materials enable the occurrence of a reversed transition of the carriers from a deep‐level energy trap to a shallow‐level trap upon excitation by low‐energy NIR photons. Thus these new materials can be charged circularly via deep‐tissue penetrable NIR photons, which is unable to be done for existing PLPs, and emit afterglow signals. This conceptual work will lay the foundation to design new categories of NIR‐absorptive–NIR‐emissive PLPs and nanoparticles featuring physically harmless and deep tissue penetrable NIR light renewability and sets the stage for numerous biological applications, which have been limited by current materials.
Solar Driven Interfacial Steam Generation Derived from Biodegradable Luffa Sponge
Authors: Saleque Ahmed Mortuza , Ma Sainan , Ahmed Safayet , Hossain Mohammad Ismail , Qarony Wayesh , Tsang Yuen Hong
Published: February 2021

A chemically treated luffa sponge (LS) derived from the ripe fruit of the Luffa cylindrica (LC) plant is investigated as an efficient solar photothermal conversion material for water purification applications for the very first time. Hydrophilicity and solar absorbance of the LS are enhanced by dopamine treatment and candle soot surface coating. The fabricated surface modified LS (SM‐LS) leads to a superb solar evaporation rate of water as high as 1.30 kg m−2 h−1, which is five times higher than that of the freshwater under 1 sun illumination. The outdoor experiment shows an excellent solar evaporation efficiency of 79.98%, which is significantly higher than other low‐cost materials. Such SM‐LS can be further applied to desalinate seawater, where it is shown that 1 m2 of surface‐modified LS can produce 7.5–8 L of freshwater per day. Hence, the proposed system can be utilized in remote areas and refugee camps.
Controllable Thin‐Film Approaches for Doping and Alloying Transition Metal Dichalcogenides Monolayers
Authors: Lin Yu‐Chuan , Torsi Riccardo , Geohegan David B. , Robinson Joshua A. , Xiao Kai
Published: February 2021

Two‐dimensional (2D) transition metal dichalcogenides (TMDs) exhibit exciting properties and versatile material chemistry that are promising for device miniaturization, energy, quantum information science, and optoelectronics. Their outstanding structural stability permits the introduction of various foreign dopants that can modulate their optical and electronic properties and induce phase transitions, thereby adding new functionalities such as magnetism, ferroelectricity, and quantum states. To accelerate their technological readiness, it is essential to develop controllable synthesis and processing techniques to precisely engineer the compositions and phases of 2D TMDs. While most reviews emphasize properties and applications of doped TMDs, here, recent progress on thin‐film synthesis and processing techniques that show excellent controllability for substitutional doping of 2D TMDs are reported. These techniques are categorized into bottom–up methods that grow doped samples on substrates directly and top–down methods that use energetic sources to implant dopants into existing 2D crystals. The doped and alloyed variants from Group VI TMDs will be at the center of technical discussions, as they are expected to play essential roles in next‐generation optoelectronic applications. Theoretical backgrounds based on first principles calculations will precede the technical discussions to help the reader understand each element's likelihood of substitutional doping and the expected impact on the material properties.
Optimization of tobacco water‐fertilizer coupling scheme under effective microorganisms biochar‐based fertilizer application condition
Authors: Li Xiuneng , Shao Xiaohou , Li Rongqi , Gao Chao , Yang Xu , Ding Fuzhang , Yuan Youbo
Published: February 2021

An appropriate coupling of water fertilizer can improve the quality and yield of tobacco (Nicotiana tabacum L.). However, the optimal scheme of that is still unknown under the condition of effective microorganisms (EM) biochar‐based fertilizer application. In this study, 12 treatments were set up, which were divided into four fertilization gradients (0, 100, 300, and 600 g pot–1, represented CK1–CK3, T1–T3, T4–T6, and T7–T9, respectively), and each fertilization gradient had three irrigation gradients (40, 80, and 120 L pot–1). Each treatment was set in triplicate. Compared to CK, the nicotine content, reducing sugar, total nitrogen, potassium, chlorine, and yield of flue‐cured tobacco increased by 13.22–48.87%, 1.53–13.46%, 7.68–29.23%, 7.73–21.76%, 6.48–34.55%, and 7.93–65.51% after the application of EM biochar‐based fertilizer. The quality of flue‐cured tobacco was less affected by the amount of irrigation (P > .05), and the yield was positively correlated with the amount of irrigation and EM biochar‐based fertilizer (P < .05). The principal component analysis (PCA) was performed on all indexes of flue‐cured tobacco quality and established the comprehensive evaluation system. Analytic hierarchy process–entropy weight method (AHP–EWM) and projection pursuit classification (PPC) algorithms were utilized to build the model, and the optimal water–fertilizer coupling scheme was selected according to AHP–EWM score and projection values. In conclusion, 120 L pot–1 irrigation combined with 100 g pot–1 of EM biochar‐based fertilizer application treatment was the best water‐fertilizer coupling scheme, and the AHP–EWM score and projection value were .632 and 1.169. The results of this study might provide theoretical and practical guidance for the plantation of flue‐cured tobacco in production areas.
Using workers' compensation claims to investigate occupational injuries among residential day laborers and domestic workers
Authors: Riley Kevin , Majano Rosario
Published: February 2021

Background

While many states have legal provisions to extend workers' compensation eligibility to day laborers or domestic workers hired directly by homeowners or families, little is known about the nature or frequency of injury claims submitted on behalf of these “residential employees.”

Methods

We examined California workers' compensation claims records for injuries that appear to have occurred in residential settings between 2008 and 2018 and where the employer of record was an individual or family. We examined the demographic, occupational, and injury characteristics of our sample and analyzed factors that contribute to the likelihood of a claim resulting in some sort of payment.

Results

We identified 5,463 workers' compensation claims that were likely submitted on behalf of residential employees. Claims most commonly reflected injuries to workers performing housekeeping tasks, followed by construction/maintenance and caregiving. Workers performing construction/maintenance or gardening/landscaping tasks were more likely to be injured on the same day of hire and were more likely to require hospitalization or emergency treatment for their injuries; however, these workers also had a smaller proportion of claims that resulted in payment. We found that employment tenure had the biggest impact on the likelihood of payment, with the odds increasing sharply after the first day of work.

Conclusions

Although the claims in our data set likely represent only a small fraction of all injuries to residential day laborers and domestic workers during this period, we suggest that workers' compensation claims can provide valuable clues for better understanding occupational injuries among workers in this largely informal sector.
Precisely Constructed Silver Active Sites in Gold Nanoclusters for Chemical Fixation of CO2
Authors: Li Guangjun , Sui Xin , Cai Xiao , Hu Weigang , Liu Xu , Chen Mingyang , Zhu Yan
Published: February 2021

Precise control of the composition and structure of active sites in an atom‐by‐atom fashion remains insuperable for heterogeneous catalysts. Here, we introduce tailor‐made catalytic sites for the cycloaddition of CO2 to epoxides achieved by implementing Ag atoms at different levels of liberation in atomically precise Au nanoclusters. Our results reveal that a single open Ag site on the Au19Ag4 cluster improves the ring‐opening of epoxides and sequent CO2 insertion, while the partially exposed Ag site on the Au20Ag1 cluster exhibits a weak affinity for epoxides and poor efficiency for CO2 capture. Structural tunability imparted by the atom‐by‐atom tailoring and unusual atomic charges distributed on Au and Ag atoms of the three clusters seem to be crucial for promoting challenging bond cleavages and formations in the chemical utilization of CO2.
New Synthetic Approaches toN‐Aryl and π‐Expanded Diketopyrrolopyrroles as New Building Blocks for Organic Optoelectronic Materials
Authors: Jiang Wenlin , Liu Zitong , Zhu Danlei , Zheng Wenyu , Chen Liangliang , Zhang Xisha , Zhang Guanxin , Yi Yuanping , Jiang Lang , Zhang Deqing
Published: February 2021

Diketopyrrolopyrrole (DPP) as a building block has been intensively investigated for organic semiconductors and light emitting materials. The synthesis ofN‐aryl DPPs remains challenging. Herein, we firstly report a new easily handled synthetic method towardN‐aryl DPPs through H‐DPP with diaryliodonium salt in the presence of CuI, which shows broad reaction scope. SixteenN‐aryl DPPs, including phenyl, furan and thiophene as flanking aromatic groups, were synthesized with yields up to 78 %. TheseN‐aryl DPPs are fluorescent in both solutions and solid states, with quantum yields up to 96 % and 40 %, respectively. Moreover, we show that the reaction between H‐DPP and diaryliodonium salt can lead to π‐expanded DPPs by using Pd(OAc)2as catalyst. Nine π‐expanded DPPs were obtained in 27–61 % yields. These π‐expanded DPPs exhibit good semiconducting properties with hole mobility of 0.71 cm2 V−1 s−1, demonstrating that they are useful building blocks for high performance organic semiconductors.
Parahydrogen‐Induced Polarization of Amino Acids
Authors: Pravdivtsev Andrey N. , Buntkowsky Gerd , Duckett Simon B. , Koptyug Igor V. , Hövener Jan‐Bernd
Published: February 2021

Nuclear magnetic resonance (NMR) has become a universal method for biochemical and biomedical studies, including metabolomics, proteomics, and magnetic resonance imaging (MRI). By increasing the signal of selected molecules, the hyperpolarization of nuclear spin has expanded the reach of NMR and MRI even further (e.g. hyperpolarized solid‐state NMR and metabolic imaging in vivo). Parahydrogen (pH2) offers a fast and cost‐efficient way to achieve hyperpolarization, and the last decade has seen extensive advances, including the synthesis of new tracers, catalysts, and transfer methods. The portfolio of hyperpolarized molecules now includes amino acids, which are of great interest for many applications. Here, we provide an overview of the current literature and developments in the hyperpolarization of amino acids and peptides.
Exact simultaneous confidence intervals for logical selection of a biomarker cut‐point
Authors: Han Yang , Tang Szu‐Yu , Lin Hui‐Min , Hsu Jason C.
Published: February 2021

This article proposes four new principles for logical biomarker cut‐point selection methods to adhere to: subgroup sensibility, sensitivity, specificity, and target monotonicity. At every cut‐point value, our method gives confidence intervals not only for the efficacy at that cut‐point value, but also efficacies in the marker‐positive and marker‐negative subgroups defined by that cut‐point. These confidence intervals are given simultaneously for all possible cut‐point values. Using Alzheimer's disease (AD) and type 2 diabetes (T2DM) as examples, we show our method achieves the four principles. Our method strongly controls familywise type I error rate (FWER) across both levels of multiplicity: the multiplicity of having marker‐positive and marker‐negative subgroups at each cut‐point, and the multiplicity of searching through infinitely many cut‐points. This is in contrast to other available methods. The confidence level of our simultaneous confidence intervals is in fact exact (not conservative). An application (app) is available, which implements the method we propose.
UPLC–MS/MS method for the simultaneous quantification of pravastatin, fexofenadine, rosuvastatin, and methotrexate in a hepatic uptake model and its application to the possible drug–drug interaction study of triptolide
Authors: Wu Wei , Cheng Rui , Jiang Zhenzhou , Zhang Luyong , Huang Xin
Published: February 2021

A rapid and specific UPLC–MS/MS method with a total run time of 3.5 min was developed for the determination of pravastatin, fexofenadine, rosuvastatin, and methotrexate in rat primary hepatocytes. After protein precipitation with 70% acetonitrile (containing 30% H2O), these four analytes were separated under gradient conditions with a mobile phase consisting of 0.03% acetic acid (v/v) and methanol at a flow rate of 0.50 mL/min. The linearity, recovery, matrix effect, accuracy, precision, and stability of the method were well validated. We evaluated drug–drug interactions based on these four compounds in freshly suspended hepatocytes. The hepatic uptake of pravastatin, fexofenadine, rosuvastatin, and methotrexate at 4°C was significantly lower than that at 37°C, and the hepatocytes were saturable with increased substrate concentration and culture time, suggesting that the rat primary hepatocyte model was successfully established. Triptolide showed a significant inhibitory effect on the hepatic uptake of these four compounds. In conclusion, this method was successfully employed for the quantification of pravastatin, fexofenadine, rosuvastatin, and methotrexate and was used to verify the rat primary hepatocyte model for Oatp1, Oatp2, Oatp4, and Oat2 transporter studies. Then, we applied this model to explore the effect of triptolide on these four transporters.
Preparation of silicon‐based soybean base oil by modified soybean oil by transesterification and hydrosilation
Authors: Zhu Xiaobin , Yun Zhi , Gui Xia
Published: February 2021

A new green lubricating base oil was synthesized from soybean oil and triethyl silane by a combination of transesterification and hydrosilylation. The factors affecting the process of hydrosilylation were thoroughly investigated. AlCl3/C catalyst as catalyst for hydrosilylation showed better catalytic performance, and a higher yield of 36.79% was obtained under optimal condition of molar ratio of transesterified soybean oils/triethyl silane (1:1.1), reaction temperature 120°C, and reaction time 8 h. In addition, the performance of silicon‐based soybean base oil was tested according to industry standards. Compared with soybean oil, silicon‐based soybean base oil was obtained with high viscosity index, good pour point of −17°C, and excellent wear characteristic.
Tissue engineering and regenerative therapeutics: The nexus of chemical engineering and translational medicine
Authors: Arambula‐Maldonado Rebeca , Geraili Armin , Xing Malcolm , Mequanint Kibret
Published: February 2021

Since its emergence nearly 30 years ago with the goal of fabricating replacement human tissues or assisting the body in repairing itself, several advances have been made in the fields of tissue engineering and regenerative medicine. The assembly of living cells into tissues is akin to the scale‐up operation of a chemical or biochemical process with several modules or units affecting the final product. The major modules or units in tissue engineering and regenerative medicine are cells, biodegradable scaffolds, bioreactors, and biomolecules. Each module is analogous to unit operations, where individual units must come together to successfully design engineered tissues for therapeutic and drug discovery applications. Basic principles of biological sciences, chemical engineering, materials chemistry, and polymer processing are frequently employed. More specifically, knowledge about viscous fluid flow, mass transfer, and reaction engineering is essential in tissue engineering. In this review article, we present the nexus between chemical engineering and tissue engineering for the rational design of engineered tissues or injectable cell‐laden hydrogel systems.