bluuebunny/crossref_metadata_2025 huggingface dataset:
Rating Evaluation of Fire Risk Associated with Plastics
Authors: You Ji Sun , Chung Yeong-jin
Published: May 2021

In this study, plastics such as glass fiber reinforced plastic (GFRP), polystyrene (PS), polycarbonate (PC), polypropylene (PP), polyvinyl chloride (PVC) were selected, and the fire risk associated with them was investigated using a cone calorimeter, as per ISO 5660-1. These values were measured to comprehensively predict the fire risk by Chung’s equations- Ⅱ. Standard materials (PMMA) were used to standardize the fire hazard assessment, and the fire risk was classified and evaluated by new Chung’s equations-III and Chung’s equation-IV. The fire performance index-II of Chung’s equations-Ⅱ showed that PVC had the highest FPI-II of 32.04 s2/kW, whereas PS had the lowest FPI-Ⅱ of 0.07 s2/kW. From the viewpoint of FGI-Ⅱ, the lowest fire growth index-Ⅱ was 0.09 kW/s2 for PVC, and the highest fire growth index-Ⅱ for PS was 3.41 kW/s2. The FPI-Ⅲ of Chung’s equations-Ⅲ had the lowest fire performance index-Ⅲ for PS (0.02) and highest fire performance index-Ⅲ for PVC (89). The FGI-Ⅲ had the highest fire growth index-Ⅲ of 20.1, and PS and PVC were found to be the safest materials with an FGI of 0.5. The FRI-Ⅳ of Chung’s equation-Ⅳ was in the following order: PS (100.5) ≫ PP (2.43) > PC (1.12) > PMMA (1.0) > FRP (0.19) > PVC (0.01). Therefore, it was concluded that the fire risk associated with PVC is lowest, whereas that associated with PS is highest.
Development and Safety Evaluation of Electrical Fire Prevention System (ETEC-DPS)
Authors: Choi Chung-Seog
Published: May 2021

In this study, we developed an electrical fire prevention system (ETEC-DPS) to prevent electrical fires by detecting the fire current (Igr) generated from electrical wires in real time. We aimed to present an evaluation of the product by verifying its safety. The printed circuit board (PCB) used inside the ETEC-DPS was 90 mm wide and 55 mm long. The PCB was produced using a flame-retardant ABS resin. Three valid numbers were displayed for the measurement of the fire current, and an Igr of up to 0.1 mA flowing into the wire was detected in real time. It was designed to sound an alarm at the same time that the LED lamp flashed as the Igr of the wire increased and the set value was reached. RS485 had a built-in communication function, which checked the real-time status of the electrical wire on the administrator's PC. In addition, a short circuit warning breaker (JER-E2S) with built-in LED lamps was installed in the quarterly circuit. In addition, for the safety assessment of the ETEC-DPS, the marking of Igr, flashing LED lamps, alarm sound transmission, and communication functions were evaluated. The developed ETEC-DPS satisfied all the assessment items and is believed to be able to fundamentally prevent the generation of electrical fires if installed in a building.
A Study of A Survey of Fire-Workers About Unwanted Fire Alarms
Authors: Choi Han-Bit , Hwang Euy-Hong , Lee Sung-Eun
Published: May 2021

Unwanted fire alarms of firefighting facilities is the cause of reducing the reliability of firefighting facilities for occupants. Accordingly, it is intended to review the theoretical background of unwanted fire alarms of firefighting facilities and to investigate opinions of firefighting-related workers on unwanted fire alarms. There were 282 participants, all of whom participated online. The majority of respondents were those who had a lot of experience and could distinguish between unwanted fire alarms and fire reports. In addition, in detail, the equipment and location of the generator, the time of the occurrence, the cause of the occurrence, the management method, and the subject were identified. As a result, it was confirmed that the most unwanted fire alarms were in the detector, and there was a problem in the function or environment. Hence, consideration of temperature and humidity was necessary.
Recognition and Status of Response Equipment Related to Chemical Accidents and Terrorism
Authors: Kim Si-Kuk , Choi Su-Gil , Nam Yeong-Jae , Hong Sung-Chul
Published: May 2021

This study analyzes the perception, status, and problems of domestic firefighters related to chemical accidents and chemical terror response equipment. “How to use on-site response facilities and equipment” was 10% when “0 times” and 28.4% when “1 to 4 times,” indicating that the importance of the ‘experience’ category is greatly increased when there is a lack of relative experience. As for whether measurement equipment is retained, 20.0% of negative responses in the ‘special structure’ were found to differ in function by “Duty.” The effects of equipment-related proficiency and preference appear to be differences in equipment primarily held by special and chemical rescue teams. Problems with on-site response will require advisory experts on post-processing and analyses and the training of professional firefighters. Accordingly, through intensive interest and analyses in the field of special disaster responses, securing expertise, and fostering professional personnel, these problems can be addressed.
Mediated Effect of Blended-Learning Strategy in Relationship between Adult Learner-Based Interaction and Learning Effectiveness: New Appointed Fire-Fighter Education
Authors: Seo Joo-Wan , Kim Hee-Dong
Published: May 2021

The purpose of this study is to examine the mediated effect of the blended-learning strategy in the relationship between the interaction and learning effectiveness of new firefighters. The Baron and Kenny method of mediated effect analysis was applied to 259 collected samples, and SPSS 18.0 was used to perform linear regression analysis. It was found that the blended-learning group was more effective in learning than the non-blended-learning group. The interaction and learning effectiveness between the targets showed significant results, and the learning strategy of blended-learning exhibited partial mediated effects in the relationship between interaction and learning effectiveness. In particular, the learning attitude of the learning strategy was the combination of learners, learning content, and learning effectiveness during an interaction and partial mediated effects on learning persistence were identified. Based on these results, practical implications on envisioning teaching and learning design from the learner's perspective as a learning strategy to enhance learning effectiveness in a blended-learning situation are presented.
Application of Oxygen Sensor for Healthcare to Measure Heat Release Rate Based on Oxygen Consumption Calorimetry
Authors: Yun Hong-Seok , Ryu Sang-Hoon , Hwang Cheol-Hong
Published: May 2021

In an oxygen consumption calorimeter system for measuring heat release rate, the CO/CO2 analyzer and the O2 analyzer for chemical species analysis of the sampling gas are the main factors that increase the construction cost of the system. In this experimental study, a low-cost device with performance similar to that of the existing high-cost device was developed. To evaluate the contribution of the CO/CO2 analyzer to the measurement of the heat release rate, the performance of unsteady and steady-state conditions depending on whether CO/CO2 was measured for diffusion flames with various fire growth rates was examined. As a result, it was confirmed that when only the O2 concentration was considered, the heat release rate could be measured accurately. Based on these results, the measurement performance of a low-cost O2 analyzer manufactured using an oxygen sensor for healthcare was verified. As a result of the verification of the low-cost O2 analyzer for diffusion flames with various fire growth rates, it was confirmed that the relative error was within 10% for unsteady and steady-state fire sources and can be used to measure the heat release rate.
Necessity of Applying Lifesaving Smart Technology for Vulnerable Class in Nursing Facilities: Focus on Introduction of RFID-based Positioning System and 3D Scanning Technology
Authors: Kwon Hyeok , Youn Chul Jin , Kim Hee Dong
Published: May 2021

This study was conducted to develop smart technology for early effective lifesaving in nursing facilities during fire outbreaks. A questionnaire was prepared for some expert groups, and the results confirmed that active information acquisition is necessary for initial lifesaving. In particular, initial information acquisition is vital. A 3D scanning and radio-frequency identification positioning system was used in this study. It was confirmed that the ultimate goal of technology development to improve field response capabilities is to minimize human damage, and the 3D scanning technology and location tag system technology applied in this study helped achieve the goal. In addition, 3D scanning and positioning system techniques are not limited to nursing facilities but may be extended and applied to targets with high fire risk, such as hospitals and children accommodation facilities with many prisoners.
Potential of Microalgae in Bioremediation of Wastewater
Authors: Ahmad Imran , Abdullah Norhayati , Koji I. , Yuzir A. , Mohamad S.E.
Published: May 2021

The increase in global pollution, industrialization and fast economic progress are considered to inflict serious consequences to the quality and availability of water throughout the world. Wastewater is generated from three major sources, i.e. industrial, agricultural, and municipal which contain pollutants, such as: xenobiotics, microplastics, heavy metals and augmented by high amount of carbon, phosphorus, and nitrogen compounds. Wastewater treatment is one of the most pressing issues since it cannot be achieved by any specific technology because of the varying nature and concentrations of pollutants and efficiency of the treatment technologies. The degradation capacity of these conventional treatment technologies is limited, especially regarding heavy metals, nutrients, and xenobiotics, steering the researchers to bioremediation using microalgae (Phycoremediation). Bioremediation can be defined as use of microalgae  for removal or biotransformation of pollutants and CO2 from wastewater with concomitant biomass production. However, the usage of wastewaters for the bulk cultivation of microalgae is advantageous for reducing carbon, nutrients cost, minimizing the consumption of freshwater, nitrogen, phosphorus recovery, and removal of other pollutants from wastewater and producing sufficient biomass for value addition for either biofuels or other value-added compounds. Several types of microalgae like Chlorella and Dunaliella have proved their applicability in the treatment of wastewaters. The bottlenecks concerning the microalgal wastewater bioremediation need to be identified and elucidated to proceed in bioremediation using microalgae. This objective of this paper is to provide an insight about the treatment of different wastewaters using microalgae and microalgal potential in the treatment of wastewaters containing heavy metals and emerging contaminants, with the specialized cultivation systems. This review also summarizes the end use applications of microalgal biomass which makes the bioremediation aspect more environmentally sustainable. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
An analysis on urban shrinkage trends of all Japanese cities by detecting relative densely inhabited districts – Changes in urban form of Japanese cities in an era of shrinking population, part 2
Authors: Kawabe Akihiro , Watanabe Shun
Published: May 2021

To analyze the method of urban shrinkage in Japan, a densely inhabited district (DID) has been applied in some previous studies as an index of urban areas or city centers. The problem with this method is that shrinkage in cities where no DID exists cannot be analyzed. Therefore, a relative threshold for urban areas or city centers is required. In this study, we propose a method for detecting a relative densely inhabited district (RDID) improved by information loss minimization. Furthermore, we identified the urban shrinkage or structural changes in Japanese cities using RDIDs and analyzed the changing trends from the years 1995–2015.
Influence of Cooling Rates on the Microstructure and Mechanical Properties of Aluminum Titanate Flexible Ceramic
Authors: Lian Jiawei , Shan Qingliang , Chen Weiwei , Ma Qian , Zeng Shenghui , Xiong Hao , Wang Yewei , Xu Qiankun , Shui Anze
Published: May 2021

Herein, aluminum titanate (Al2TiO5, AT) flexible ceramics with different cooling rates (program‐controlling cooling (10 and 20 °C min−1), air cooling (≈400 °C min−1), and water cooling (>1000 °C min−1) are fabricated by reaction sintering of Al2O3and TiO2. The effect of cooling rates on microstructures and the mechanical properties of AT ceramics are systematically investigated. The microcrack width and density of AT ceramics with different cooling rates are statistically calculated. In addition, the effect of a microcracks structure on the mechanical properties of AT ceramics is deeply studied. Results show that the increase in cooling rate will increase the width and density of microcrack, leading to a suitable increase in flexibility and a slight decrease in strength. When AT is cooled in air, the best bending strain of 1.10% can be obtained, with a median microcrack width of 0.533 μm and a density of 6831.88 ± 374.87 N mm−2. It is hopeful that through this research, the effect of cooling rate on the mechanical properties of AT flexible ceramics can be deeply understood, and the strategy used in this research can be used in other exploration of similar material.
Engineered Electrode Structure for High‐Performance 3D‐Printed All‐Solid‐State Flexible Microsupercapacitors
Authors: Zhang Yan , Wang Yaling , Ganesh Anandha , Wang Guolong , Shi Xiaowei , Qiao Yide , Liu Jiamei , Liu Heguang , Li Lei
Published: May 2021

Graphene aggregation is the major issue limiting its electrochemical performance when used as electrode material for microsupercapacitors (MSCs) with the interdigitated architecture. Solving this issue boosts the device's electrochemical performance, especially the areal energy density, facilitating its applications in advanced miniaturized electronic systems. Herein, a facile method to prepare the graphene−carbon black composite ink for the direct 3D printing of electrodes of MSCs is developed. Carbon black present in the composite ink tailors the graphene sheets space in the electrode structure during the 3D printing process, relieving the graphene aggregation issue. The MSCs show great improved electrochemical performance with a high areal energy density (2.49 μWh cm−2), high power density (0.25 mW cm−2), promising cycling stability, and good mechanical flexibility. The method developed herein paves a way to prepare high‐performance, all‐solid‐state flexible MSCs in a scalable process.
Single‐Crystalline Silicon Frameworks: A New Platform for Transparent Flexible Optoelectronics
Authors: Zhang Bing‐Chang , Shi Yi‐Hao , Mao Jie , Huang Si‐Yi , Shao Zhi‐Bin , Zheng Cai‐Jun , Jie Jian‐Sheng , Zhang Xiao‐Hong
Published: May 2021

Single‐crystalline silicon (sc‐Si) is the dominant semiconductor material for the modern electronics industry. Despite their excellent photoelectric and electronic properties, the rigidity, brittleness, and nontransparency of commonly used silicon wafers limit their application in transparent flexible optoelectronics. In this study, a new type of Si microstructure, named single‐crystalline Si frameworks (sc‐SiFs), is developed, through a combination of wet‐etching and microfabrication technologies. The sc‐SiFs are self‐supported, flexible, lightweight, tailorable, and highly transparent. They can withstand a small bending radius of less than 0.5 mm and have a transparency of up to 96% in all wavelength ranges, owing to the hollowed‐out framework structures. Thus, the sc‐SiFs provide a new platform for high‐performance transparent flexible optoelectronics. Taking transparent flexible photodetectors (TFPDs) as an example, substrate‐free and self‐driven TFPDs are achieved based on the sc‐SiFs. The devices exhibit superior performance compared to other reported TFPDs and reveal the great potential for integrated optoelectronic applications. The development of sc‐SiFs paves the way toward the fabrication of high‐performance transparent flexible devices for a host of applications, including e‐skins, the Internet of Things, transparent flexible displays, and artificial visual cortexes.
Exceptional Cocatalyst‐Free Photo‐Enhanced Piezocatalytic Hydrogen Evolution of Carbon Nitride Nanosheets from Strong In‐Plane Polarization
Authors: Hu Cheng , Chen Fang , Wang Yonggang , Tian Na , Ma Tianyi , Zhang Yihe , Huang Hongwei
Published: May 2021

Utilizing mechanical energy to produce hydrogen is emerging as a promising way to generate renewable energy, but is challenged by low efficiency and scanty cognition. In this work, graphitic carbon nitride (g‐C3N4) with an atomically thin sheet‐like structure is applied for prominent piezocatalytic and photo‐enhanced piezocatalytic H2 production. It is revealed that the anomalous piezoelectricity in g‐C3N4 originates from the strong in‐plane polarization along the a‐axis, contributed by the superimposed polar tri‐s‐triazine units and flexoelectric effect derived from the structured triangular cavities, which provides powerful electrochemical driving force for the water reduction reaction. Furthermore, the photo‐enhanced charge transfer enables g‐C3N4 nanosheets to reserve more energized polarization charges to fully participate in the reaction at the surface reactive sites enriched by strain‐induced carbon vacancies. Without any cocatalysts, an exceptional photo‐piezocatalytic H2 evolution rate of 12.16 mmol g−1 h−1 is delivered by the g‐C3N4 nanosheets, far exceeding that of previously reported piezocatalysts and g‐C3N4 photocatalysts. Further, high pure‐water‐splitting performance with production of the value‐added oxidation product H2O2 via photo‐piezocatalysis is also disclosed. This work not only exposes the potential of g‐C3N4 as a piezo‐semiconductor for catalytic H2 evolution, but also breaks a new ground for the conversion of solar and mechanical energy by photomediated piezocatalytic reaction.
Surface Plasmon Resonance of Gold Nano‐Sea‐Urchins Controlled by Machine‐Learning‐Based Regulation in Seed‐Mediated Growth
Authors: Wu Chia-Chen , Pan Fei , Su Yen-Hsun
Published: May 2021

Gold sea‐urchin‐like nanoparticles (GSNPs) are promising candidates for cancer thermotherapy. Due to the complex growth of GSNPs and the need for a precise prediction of their surface plasmon wavelength, genetic‐algorithm‐based artificial neural networks (GANNs) are used to determine the relationship between synthesis parameters and the surface plasmon wavelength of GSNPs grown via seed‐mediated growth assisted by machine learning. Herein, a low‐data test is trained by varying the ratio and concentration of gold seeds, sodium citrate, hydroquinone, and HAuCl4. Then, a big data confirmation is conducted through massive parameter collection from over 684 samples. The well‐trained GANN can guide parameter selection for seed‐mediated growth to obtain the desired surface plasmon wavelength. An optimal model can be obtained after big data evolution to assist the growth method screening of the seed‐mediated growth of sea‐urchin‐like gold nanoparticles (SGNPs) to achieve a stronger electromagnetic field of the surface plasmons. Machine learning has an advantage over empirical method for seed‐mediated growth and surface plasmon wavelength prediction, which increases research efficiency and decreases cost. The performance of the grown SGNPs is substantially improved in the visible domain.
An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
Authors: Solís‐Muñana Pablo , Salam Joanne , Ren Chloe Z.‐J. , Carr Bronte , Whitten Andrew E. , Warr Gregory G. , Chen Jack L.‐Y.
Published: May 2021

An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil‐water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems.

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Apparent nitrogen limitation of Robusta coffee yields in young agroforestry systems
Authors: Chavez Eduardo , Wade Jordon , Miernicki Elizabeth A. , Torres Malena , Stanek Erik C. , Subía Cristian , Caicedo Carlos , Tinoco Leider , Margenot Andrew J.
Published: May 2021

Robusta coffee (Coffea canephora Pierre ex Froehner) is an important cash crop in the lowland tropics. Similar to Arabica (C. arabica L.), agroforestry is common in these systems, though comparatively little is known about how nutrient inputs and leguminous shade trees influence Robusta nutritional status and yield. We evaluated how shading with leguminous trees across four input systems, defined largely by quantity and form (compost vs. synthetic) of nitrogen (N), phosphorus (P), and potassium (K), influenced Robusta‐based cropping systems in the Ecuadorian Amazon. Soil fertility was largely unaffected by compost and synthetic fertilizer (NPK) inputs or by shade species, and was weakly related to coffee productivity based on principal component analysis (PCA). Though litter appeared to be an agronomically appreciable source of N and P, this was only somewhat reflected in soil extractable N and P, presumably due to nutrient losses under high rainfall conditions (>3,000 mm yr−1). Patterns of variation suggest transfer of N and P from litter to soil to leaf. Conversely, litter K was unrelated to soil K, but soil K was closely related to leaf K. Robusta yields appeared to be largely N limited and were more influenced by input type (i.e., synthetic vs. organic nutrient sources) than by shade species or amount of N inputs in the form of compost or synthetic N, P, and K fertilizers. Additionally, yields across all treatments were significantly higher than regional averages, suggesting that slight investments in inputs can substantially increase productivity in maturing Robusta systems, irrespective of shade tree species selection.
Activity‐based smart AIEgens for detection, bioimaging, and therapeutics: Recent progress and outlook
Authors: Li Haidong , Kim Heejeong , Han Jingjing , Nguyen Van‐Nghia , Peng Xiaojun , Yoon Juyoung
Published: May 2021

Activity‐based approaches for designing AIEgens possess prominent advantages including high selectivity, sensitivity, and signal‐to‐noise ratio, and they have received more attention in recent years. Excellent activatable AIE probes have been reported for detecting toxic substances, imaging intracellular active molecules/biomolecules, as well as monitoring the activity of overexpressed enzymes in cancers. Moreover, the majority of activatable theranostic AIEgens can be specifically triggered in cancer cells and can kill these cells under light irradiation, while they have no distinct effect on normal cells, demonstrating satisfactory therapeutic selectivity that is superior to that of traditional chemotherapy. Thus, in this review, we systematically summarized the development of activatable AIE bioprobes in recent years from molecular design principles to biological applications. The challenges of activatable AIE probes and the corresponding solutions are described. We hope that the information provided in this review will facilitate the design of more activatable AIE probes to promote practical application of corresponding AIEgens.
Unexpected difficult tracheal intubation secondary to subglottic stenosis leading to emergency front‐of‐neck airway
Authors: Ellis H. , Iliff H. A. , Lahloub F. M. F. , Smith D. R. K. , Rees G. J.
Published: May 2021

A 26‐year‐old woman presenting for an elective day case procedure under general anaesthesia had undiagnosed subglottic stenosis leading to a life threatening airway emergency requiring emergency front‐of‐neck airway. We outline the case and discuss key anaesthetic considerations in subglottic stenosis, including concerning features of a medical/anaesthetic history and the potential for rapid deterioration of a stenotic airway following manipulation. We also consider the effect of anaesthesia on the calibre of subglottic stenosis and the effects of positive pressure ventilation. Subglottic stenosis is a rare condition with congenital, acquired and idiopathic origins; however, iatrogenic trauma is the most common cause. We are aware of a small number of published case reports of previously undiagnosed subglottic stenosis in adults discovered after induction of anaesthesia; situational deterioration to ‘cannot intubate, cannot oxygenate’ scenarios appear even rarer.
Simultaneously improved solid particle erosion resistant and strength of graphene nanoplates/carbon nanotube enhanced thermoplastic polyurethane films
Authors: Ma Yuji , Fang Mei , Huang Ming , Zhang Na , Lu Bo , Yang Peipei , Liu Chuntai , Shen Changyu
Published: May 2021

Up to now, it is a major challenge to protect leading edge of the blades from solid particle erosion. Herein, we propose a structure optimization strategy to fabricate non‐woven (NW) enhanced thermoplastic polyurethane nanocomposite films (thermoplastic polyurethane [TPU]‐NW@G/Cx) with “sandwich‐like” structure by hot pressing technology. TPU NW/graphene nanoplates/carbon nanotube (NW@G/Cx) interlayer film were first fabricated by spraying method. Then the interlayer film was laminated between TPU films to fabricate nanocomposite films. Such prepared TPU‐NW@G/Cx film shows excellent solid particle erosion resistance and high‐tensile strength. For example, the “steel‐and‐mortar” structure of NW fabric in TPU film results in high‐tensile strength of 45 MPa and storage modulus of 21.2 MPa for TPU‐NW@G/C1.0, increasing by 25% and 171% compared with original TPU film (35 MPa, 8 MPa), respectively. In addition, compared with pure TPU film, the “sandwich‐like” structure endows TPU‐NW@G/C1.2 with excellent solid particle erosion resistance and the thermal conductivity (0.251 W/m·K). These superior properties extends application of the TPU‐NW@G/Cx film on wind turbine blades.
Growth factor mimetics for skin regeneration: In vitro profiling of primary human fibroblasts and keratinocytes
Authors: Horinouchi Cintia D. S. , Oostendorp Corien , Schade Dennis , van Kuppevelt Toin H. , Daamen Willeke F.
Published: May 2021

Small molecules have gained considerable interest in regenerative medicine, as they can effectively modulate cell fates in a spatiotemporal controllable fashion. A continuous challenge in the field represents genuine mimicry or activation of growth factor signaling with small molecules. Here, we selected and profiled three compounds for their capacity to directly or indirectly activate endogenous FGF‐2, VEGF, or SHH signaling events in the context of skin regeneration. Phenotypic and functional analysis of primary skin fibroblasts and keratinocytes revealed unique, cell‐specific activity profiles for the FGF‐2 mimetic SUN11602 and the putative VEGF mimetic ONO‐1301. Whereas SUN11602 exclusively stimulated keratinocyte differentiation, ONO‐1301 mainly affected the proliferation and migration behavior of fibroblasts. In each skin cell type, both compounds selectively enhanced the expression of MMP1 and VEGFA. A combined small molecule FGF‐2/VEGF mimicry may not only improve angiogenesis‐related microcirculation but also reduce early fibrosis while facilitating wound remodeling at later stages. SUN11602 and ONO‐1301 represent valuable tools for improving the management of difficult‐to‐heal wounds, particularly for the design and development of small molecule‐functionalized, next‐generation, engineered skin substitutes.
Sensitive analysis of single nucleotide variation by Cas13d orthologs, EsCas13d and RspCas13d
Authors: Qiao Xin , Gao Yanmin , Li Jiaojiao , Wang Zhaoguan , Qiao Hongyan , Qi Hao
Published: May 2021

RNA‐guided CRISPR (RNA‐targeting clustered regularly interspaced short palindromic repeats) effector Cas13d is the smallest Class II subtype VI proteins identified so far. Here, two recently identified Cas13d effectors from Eubacterium siraeum (Es) and Ruminococcus sp. (Rsp) were characterized and applied for sensitive nucleic acid detection. We demonstrated that the special target triggered collateral cleavage of these two Cas13d orthologs could provide rapid target RNA detection in picomolar range and then the tolerance for mismatch between crRNA and target RNA was characterized as well. Finally, an additional single mismatch was introduced into crRNA to enhance the two Cas13d orthologs mediated detection of low variant allele fraction, 0.1% T790M. Overall, this study demonstrated that both EsCas13d and RspCas13d could robustly detect target RNA carrying special single‐nucleotide variation with high specificity and sensitivity, thereby providing newly qualified machinery in toolbox for efficient molecular diagnostics.
Revisiting the nodal voltage method for both human comprehension and software implementation: Towards a teaching/self‐learning simulation tool
Authors: Sousa Lino , Rocha André , Alves Mário , Pereira Francisco
Published: May 2021

This paper outlines an application—dubbedU=RIsolve(read as “you resolve”)—for helping students to learn the Nodal (or Node) Voltage Analysis method (NVM, for short) for electrical circuit analysis. The NVM enables determining the voltage in every Node in the circuit, related to a reference (Ground) Node. In turn, this enables to compute the current in every Branch (and therefore, the voltage across every component). TheU = RIsolveapplication goes far beyond the capabilities of traditional circuit simulators; as it outputs the fundamental circuit information, the methodology, the equations, and the results related to the NVM for a given circuit previously simulated inQuite Universal Circuit Simulator (QUCS). QUCS can generate a text file (callednetlist) that identifies all the circuit components/connections and that serves as an input to theU = RIsolveapplication. Additionally, users can also upload the circuit schematics to facilitate the analysis of the U = RIsolve output. Then, the user just needs to click a button to get all the reasoning of the NVM analysis.
Extended Enolates: Versatile Intermediates for Asymmetric C‐H Functionalization via Noncovalent Catalysis
Authors: Oiarbide Mikel , Palomo Claudio
Published: May 2021

Catalyst‐controlled functionalization of unmodified carbonyl compounds is a relevant operation in organic synthesis, especially when high levels of site‐ and stereoselectivity can be attained. This objective is now within reach for some subsets of enolizable substrates using various types of activation mechanisms. Recent contributions to this area include enantioselective transformations that proceed via transiently generated noncovalent di(tri)enolate‐catalyst coordination species. While relatively easier to form than simple enolate congeners, di(tri)enolates are ambifunctional in nature and so control of the reaction regioselectivity becomes an issue. This Minireview discusses in some detail this and other problems, and how noncovalent activation approaches based on metallic and metal free catalysts have been developed to advance the field.
CoaSmbOx Catalyst with Excellent Catalytic Performance for NH3 Decomposition
Authors: Wu Cui‐Ping , Jin Zhao , Xu Kai , Wang Wei‐Wei , Jia Chun‐Jiang
Published: May 2021

Main observation and conclusion

Transition metal‐rare earth oxide catalysts had the ability to catalyze ammonia decomposition according to recent years’ scientific reports. However, most of those catalysts had their own limitations: the catalytic activity was poor, and/or the active species could not clearly be identified. Here we report the CoaSmbOx catalysts with good dispersion, controllable content, and excellent catalytic performance for ammonia decomposition. The various content catalysts were synthesized by aerosol‐assisted self‐assembly approach. These catalysts had high dispersion and great morphology according to the images of the transmission electron microscope (TEM) and the scanning electron microscope (SEM). The temperature‐programmed reduction by hydrogen (H2‐TPR) and in‐situ X‐ray diffraction (XRD) results indicated that the interaction between cobalt oxide and samarium oxide influenced the redox properties of cobalt oxide. Combined with in‐situ Raman, we found that Co0 was an active species of the CoaSmbOx catalysts in ammonia decomposition. Moreover, the temperature‐programmed desorption of NH3 (NH3‐TPD) data illustrated that the addition of Sm was beneficial to the adsorption of NH3. In general, we successfully obtained the CoaSmbOx catalyst with high activity and good stability. More importantly, we have identified the structure‐function relationship of catalysts by exploring the active species in the reaction process.
Systematic review and meta‐analysis of cervical metastases in oral maxillary squamous cell carcinoma
Authors: Chia Clemente , Key Seraphina , Hasan Zubair , Virk Sohaib , Riffat Faruque
Published: May 2021

Background

Management of the node‐negative neck in oral maxillary squamous cell carcinoma (SCC), encompassing the hard palate and upper alveolar subsites of the oral cavity, is controversial, with no clear international consensus or recommendation regarding elective neck dissection in the absence of cervical metastases.

Aim

To assess the occult metastatic rate in patients with clinically node negative oral maxillary SCC; both as an overall metastatic rate, and a comparison of patients managed with an elective neck dissection at index surgery, compared to excision of the primary with clinical observation of the neck.

Methods and results

A systematic review was performed by two independent investigators for studies relating to oral maxillary SCC and analysed according to PRISMA criteria. Data were extracted from Pubmed, Ovid MEDLINE, EMBASE, and SCOPUS via relevant MeSH terms. Grey literature was searched through Google Scholar and OpenGrey. Five hundred and fifty‐three articles were identified on the initial search, 483 unique articles underwent screening against eligibility criteria, and 29 studies were identified for final data extraction. Incidence of occult metastases in patients with clinically node negative oral maxillary SCC was identified either on primary elective neck dissection or on routine follow up. Meta‐analyses were performed. Of 553 relevant articles identified on initial search, 29 were included for analysis. The pooled overall rate of occult metastases in patients initially presenting with clinically node‐negative disease was 22.2%. There is a statistically significant effect of END on decreasing regional recurrence demonstrated in this study (RR 0.36, 95% CI 0.24, 0.59).

Conclusion

The results of this systematic review and meta‐analysis suggest elective neck dissection for patients presenting with hard palate or upper alveolar SCC, even in a clinically node negative neck.
Elastic scheduler: Heterogeneous and dynamic deep Learning in the cloud
Authors: Yin Lujia , Zhang Yiming , Peng Yuxing , Li Dongsheng
Published: May 2021

GPUs and CPUs have been widely used for model training of deep learning (DL) in the cloud, where both DL workloads and resource usage might heavily change over time. Traditional training methods require beforehand specification on the type (either GPUs or CPUs) and amount of computing devices, and thus cannot elastically schedule the dynamic DL workloads onto available GPUs/CPUs. In this paper, we propose Elastic Scheduler (ES), a novel approach that efficiently supports both heterogeneous training (with different device types) and dynamic training (with varying device numbers). ES (i) accumulates local gradients and simulates multiple virtual workers on one GPU to alleviate the performance gap between GPUs and CPUs for achieving similar accuracy in heterogeneous GPU‐CPU‐hybrid training as in homogeneous training and (ii) uses local gradients stabilizes batch sizes for high accuracy without long compensation. Experiments show that ES achieves significantly higher performance than existing methods for heterogeneous and dynamic training as well as inference.
A LoRaWAN monitoring system for large buildings based on embedded edge computing in indoor environment
Authors: Li Wei , Shen Guanxi , Zhang Jingfang , Liu Dong , Choi Chang
Published: May 2021

At present, the influence of the surrounding environment on the health of humans is attracting increasing attention, and the indoor environment plays a significant role in people's health. Therefore, it is necessary to effectively monitor indoor environments in real time. With the increase of end‐devices, the rapid growth of data is exerting a pressure on the network bandwidth. To solve this problem, a LoRaWAN monitoring system for indoor environments based on embedded edge computing is proposed here. A hardware architecture of end‐devices and the workflow of the LoRaWAN gateway are designed. In the gateway, edge computing is applied to manage the integrated access device and clean data. The experimental results show that the data reduction rate increased obviously after using edge computing. The environmental data can be transmitted in real time, and the communication efficiency of the system can be improved.
Bachman's Sparrow survival and nest predation response to a hardwood canopy reduction experiment
Authors: Malone Kristen M. , Terhune Theron M. , Sieving Kathryn E.
Published: May 2021

Where historical fire regimes have been disrupted, reduction in woody vegetation is often used to maintain or restore habitat for grassland and early successional birds. In pine savanna ecosystems of the southeastern USA, mechanical hardwood canopy reduction can restore pine savanna communities and is often employed on privately owned lands to improve habitat for the Northern Bobwhite (Colinus virginianus), although scant empirical evidence exists of its effects on target or non‐target species. We measured the response of a pine savanna specialist, the Bachman's Sparrow (Peucaea aestivalis), to large‐scale hardwood reduction in a before–after–control–impact design on two properties where two‐year fire‐return intervals were established and the Bachman's Sparrow population was stable. We investigated the effects of mechanical hardwood reduction on Bachman's Sparrow daily nest survival, cause‐specific nest mortality and adult male annual survival. During the four‐year study, we monitored 107 Bachman's Sparrow nests, recorded 49 nest predation events, and banded 113 adult male Bachman's Sparrows. We found Bachman's Sparrow nest and adult survival were resilient to changes in the hardwood canopy and did not differ significantly between treatment and control sites. Average annual adult male survival was 0.41 (0.32–0.52) and daily survival rate of nests with surveillance declined annually from 0.94 (0.92–0.96) to 0.88 (0.83–0.92). The identity of predators at nests was dominated by two snake species, black racer (Coluber constrictor) and corn snake (Pantherophis guttata). We found evidence for opposing treatment effects on the frequency of nest depredations by the dominant species; racers responded positively and corn snakes responded negatively. Our results suggest a moderate midstory canopy does not limit Bachman's Sparrow vital rates when management includes frequent prescribed fire. Our results also suggest hardwood reduction to mitigate nest predation may be complicated with a diverse predator suite.
Outcomes among acute heart failure emergency department patients by preserved vs. reduced ejection fraction
Authors: Sax Dana R. , Rana Jamal S. , Mark Dustin G. , Huang Jie , Collins Sean P. , Liu Dandan , Storrow Alan B. , Reed Mary E. ,   KP CREST Network
Published: May 2021

Aims

This study aimed to assess short‐term outcomes among emergency department (ED) patients with acute heart failure (AHF) by preserved (≥50%) vs. reduced (<50%) ejection fraction (EF).

Methods and results

We conducted a retrospective, multicentre study of adult ED patients with AHF from 2017 to 2018 in an integrated healthcare system with 21 hospitals. Among patients with known EF, our primary outcome was 30 day all‐cause mortality, comparing patients with heart failure with preserved EF (HFpEF) and heart failure with reduced EF (HFrEF), adjusted for known risk factors. We ran separate multivariate regression models to compare 30 day mortality between HFpEF and HFrEF patients stratified by ED disposition (admit, observe, and discharge). Our secondary outcomes were adjusted 30 day all‐cause return hospital admission and rates of non‐fatal serious adverse events, including new intra‐aorta balloon pump, endotracheal intubation, renal failure requiring dialysis, myocardial infarction, or coronary revascularization. We conducted a sensitivity analysis among patients with EF ≤ 40% and compared our primary and secondary outcomes among patients with EF ≤ 40% with those with EF ≥ 50%. Among the 26 050 total ED encounters for AHF, 15 275 (58.6%) had known EF and 62.4% had HFpEF. The mean age was 76, 49.6% were women, and 60.5% were white. We found that 62.4% of patients were admitted, 18.3% were observed, and 19.3% were discharged from the ED. The 30 day all‐cause mortality rate was lowest among discharged patients (3.9%), intermediate among observed patients (5.9%), and highest among admitted patients (13.9%). Overall, the adjusted 30 day mortality rate was significantly higher among HFpEF patients compared with HFrEF patients (10.2% vs. 8.4%, P = 0.0004). HFpEF patients had higher mortality regardless of ED disposition, although the difference was only significant among admitted patients. The adjusted 30 day return hospital admission rates were not significantly different between HFpEF and HFrEF patients (17.9% vs. 17.8%, P = 0.89). The adjusted 30 day non‐fatal serious adverse event rates were significantly higher among HFrEF patients compared with HFpEF patients (13.7% vs. 11.1%, P < 0.0001), driven by myocardial infarction and coronary revascularization. We found that 3692 patients had EF ≤ 40%. Patients with EF ≥ 50% had significantly higher adjusted 30 day mortality rates compared with those with EF ≤ 40% (10.2% vs. 8.4%, P < 0.05).

Conclusion

In a contemporary population, almost three quarters of ED patients with AHF and known EF have HFpEF. These patients have higher 30 day adjusted mortality compared with those with HFrEF. Further studies might evaluate the underlying factors associated with this difference and target interventions to improve outcomes.
Epinephrine administration in venoarterial extracorporeal membrane oxygenation patients is associated with mortality: a retrospective cohort study
Authors: Massart Nicolas , Mansour Alexandre , Ross James T. , Ecoffey Claude , Aninat Caroline , Verhoye Jean‐Philippe , Launey Yoann , Tadie Jean‐Marc , Auffret Vincent , Flecher Erwan , Nesseler Nicolas
Published: May 2021

Aims

Knowledge about the impact of epinephrine on the outcome in venoarterial (VA) extracorporeal membrane oxygenation (ECMO) patients is limited, and existing data are conflicting.

Methods and results

We conducted a retrospective cohort study in a 1500 bed tertiary university hospital. Five hundred and eighty‐nine VA‐ECMO patients were analysed. The median age was 57 years [47–65], 68% of male. The major indications for ECMO were post‐cardiotomy cardiogenic shock (CS) (38%) and medical CS (36%). Two hundred and sixty‐two (44.5%) patients received epinephrine alone or associated with another catecholamine while on ECMO. Baseline factors significantly associated with epinephrine administration were younger age, higher sequential organ failure assessment score, cardiac arrest at implantation, and intra‐aortic balloon pump support at implantation, whereas medical CS and dobutamine administration were significantly associated with a lower risk of epinephrine administration. Epinephrine administration was independently associated with death [hazard ratio = 1.68 (1.44–2.23); P < 0.01]. A sensitivity analysis with propensity score inverse probability weighting in complete cases confirmed a significant association of epinephrine administration with death [hazard ratio = 1.69 (1.43–2.00); P < 0.001].

Conclusions

Among patients who required VA‐ECMO, epinephrine administration was associated with an increased risk for death.
Emissive Platforms Employing NaYF4‐based Upconverting Nanoparticles and Mesoporous Metal Oxide Thin Films
Authors: Fernanda Torresan M. , Morrone Josefina , Sorbello Cecilia , Etchenique Roberto , Angelomé Paula C. , Wolosiuk Alejandro
Published: May 2021

We present the design and synthesis of a novel optically transparent platform based on the combination of NaYF4: Er3+, Yb3+ upconverting nanoparticles (UCNPs) and mesoporous metal oxide thin films (MOTFs). The UCNP were obtained by the thermolysis method and were deposited onto a glass substrate by spin coating. The MOTFs (TiO2, ZrO2 and SiO2), prepared by the combination of the sol‐gel approach and the self‐assembly of surfactants, were subsequently deposited on top of the particles giving rise to an ultrathin composite. The characterization of the obtained composite films indicates that they blend the properties of both starting materials: they exhibit upconverting properties, as they are capable of emitting visible light when irradiated in the NIR region, and the MOTFs deposited on top provide an ordered array of mesopores with highly accessible porosity. As the UCNPs emission properties depend on their surrounding temperature, the composite films were tested for temperature sensing applications, using both emission intensity and lifetimes of different signals, with promising results.
Studies Toward the Total Synthesis of Schinortriterpenoids: Diastereoselective Synthesis of the Left‐Hand Fragment
Authors: Yagita Ryotaro , Irie Kazuhiro , Tsukano Chihiro
Published: May 2021

Schinortriterpenoids, such as pre‐schisanartanin A and arisanlactone C, are complex and highly oxygenated polycyclic terpenes. In this study, the left‐hand fragment of this class terpenes, which possesses oxygen‐functionality at C19, was synthesized through [3+2] cycloaddition with excellent diastereoselectivity. This stereoselectivity was investigated by computational studies. Further selective transformation provided a tricyclic skeleton with the desired stereochemistry.