bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Study for the Fire Performance of EIFS with a Drencher System
Authors: Choi Jihun , Choi Suhwan , Cho Kyungsuk , Chae Seungun
Published: June 2020

The exterior insulation finish system, in which insulation is installed on the outer wall of the building, is widely used due to its ease of construction and the effect of a shorter working period. However, the combustible insulation installed in the external insulation system is vulnerable to fire due to the sudden flame propagation in the event of a fire. For this reason, the Ministry of Land, Infrastructure, and Transport is carrying out support projects to strengthen the fire stability for buildings vulnerable to fire. In this study, the performance of the drencher system was evaluated through a large-scale exterior material experiment in a building equipped with a drench system. When a flammable insulation material was used as EPS, the fire spread to the inside and outer side of EPS after 530 s and 540 s of ignition, respectively, and the results of this experiment did not meet the performance evaluation criteria. When the drencher system was installed under the same conditions as stated above, the fire spread to the outside after 266 s of ignition, and this experiment satisfied the performance evaluation criteria.
A Study on the Change in Fire Risk by Occupancy Type Using Fire Statistics
Authors: Lee Jaewon , Jin Seunghyeon , Lee Byeongheun , Kwon Youngjin
Published: June 2020

This study, as the basic research for developing fire safety guidelines for a building, analyzed the fire risk in buildings according to their occupancy type through fire statistics. This study conducted the fire statistics analysis using data of 6 years (2012-2017) obtained from the National Fire Data System. The fire risk scale of casualties and property damage per fire was classified using Importance Performance Analysis (IPA) technique. As a result, residential, transportation & vehicles, industrial and medical welfare facilities were identified as the structures with high fire risk. In addition, this study presented the fire risk grade by dividing the risk of facilities into 5 phases through SFPE's structure fire risk analysis method and ArcGIS's natural division method through subdivision of 4 types of facilities previously identified using the IPA technique.
A Study on the Consideration of the Required Operational Capabilities for the Smart Defense Drone System against Hostile Drones in National Important Facilities
Authors: Ahn Hyochun , Kim Kukjoo , Yang Hyeonsang , Hong Kyu Dok , Park Young Jun
Published: June 2020

This study aims to derive the required operational capability for the defense drone system against hostile drones in national important facilities. For the Delphi survey, the panel comprises 30 experts related to the defense drone system as well as anti-aircraft operations. The first questionnaire investigates the considerations required for the operational capabilities, and then their agreements on each extracted consideration are analyzed statistically in the second to fourth questionnaire. Consequently, 15 final considerations are reclassified with five factors such as detecting, Enterprise data sharing, incapacitating, identifying and tracking, and universal supporting.
Experimental and Numerical Study for Analyzing Applicability of Helical Piles
Authors: Jun Sanghyun , Lee Hyungho , Park Byungsoo
Published: June 2020

A helical pile is a foundation type that can be constructed to improve the bearing capacity and pullout resistance using a spiral plate affixed to the central shaft of the pile. In the past, piles were applied in formulaic shapes, but based on recent developments of threaded joints, the specifications of a helical pile can be applied depending on the site conditions. In this study, model tests and numerical modeling were performed to analyze the bearing capacity and pullout resistance based on the number, size, and position of the helix, which were the main factors of the helical pile. The bearing capacity and pullout resistance improved as the number and diameter of the helix increased. When the helix was installed near the bottom of the pile, the helical pile showed an excellent performance. In addition, by analyzing the ratio of the increase in the bearing capacity according to the area ratio of the helix as a part of the economic analysis, it is essential to consider the installation position of the helix. Based on the analysis results, it was shown that the helical pile could be improved.
Seismic Structural Analysis of Buried Pipelines and Safety Evaluation Model Based on Response Surface Method
Authors: Choi Yangrok , Ann Hojune , Kwon Kyungrok , Jang Yun-Chan , Kim Young-Pyo , Kong Jung Sik
Published: June 2020

Based on the earthquakes that occurred recently in Gyeongju and Pohang provinces, the Korea Peninsula needs to be prepared for a strong earthquake that might occur in the future. In this study, a strain tendency model based on the response surface method was used to analyze buried straight pipelines. The strains of the buried pipelines were computed through structural dynamics analysis, considering the section properties and ground types. In the case of the buried straight pipelines, this strain tendency model provided the necessary information for setting the strain-based design and a guideline for predicting post-earthquake damages in the Korea Peninsula.
An Analysis of the Effectiveness of the National Prevention System: Response to the MERS Outbreak in 2018
Authors: Jeon Se Young
Published: June 2020

As international exchanges have become more active, the inflow of new infections has become easier and the damage from these new infections has increased. It is an important task for a nation to protect its people from disease. Therefore, in order to look at the governance of the national prevention system that was reorganized in 2015, we aimed to analyze how well the governance system was implemented by taking the MERS outbreak into account. We use the three aspects of prevention of domestic inflow, initial response site, and epidemic response based on four criteria: responsiveness, expertise, transparency, and connectivity. The analysis showed that the expertise and transparency have significantly improved and the responsiveness of the immigration control sector and the connection of the initial response site were insufficient. If these analyses make up for the deficiencies, it is expected to be resolved quickly and accurately even if there are new viruses in the future.
Analytical Study for the Development of Interaction Diagram of the Fire-damaged RC Columns with Varied Heated Areas
Authors: Ryu Eunmi , Kim Heesun , Shin Yeongsoo
Published: June 2020

Inconsistent damages over the surface of structural members are expected from a compartment fire situation, which may cause additional reduction of structural performances especially in the case of reinforced concrete (RC) columns. In this study, an analytical modeling method for simplified cross section was proposed and validated for the prediction of axial strength of fire-damaged RC columns. The proposed modeling method was subsequently used to develop interaction diagrams of fire-damaged RC columns with varied heat exposure areas. Compared to the experimental results, it was found that the P-M interaction diagram allowed estimating axial force and moment capacities of the fire-damaged concrete columns.
Conformational changes of DNA repair glycosylase MutM triggered by DNA binding
Authors: Landová Barbora , Šilhán Jan
Published: June 2020

Bacterial MutM is a DNA repair glycosylase removing DNA damage generated from oxidative stress and, therefore, preventing mutations and genomic instability. MutM belongs to the Fpg/Nei family of prokaryotic enzymes sharing structural and functional similarities with their eukaryotic counterparts, for example, NEIL1–NEIL3. Here, we present two crystal structures of MutM from pathogenic Neisseria meningitidis: a MutM holoenzyme and MutM bound to DNA. The free enzyme exists in an open conformation, while upon binding to DNA, both the enzyme and DNA undergo substantial structural changes and domain rearrangement. Our data show that not only NEI glycosylases but also the MutMs undergo dramatic conformational changes. Moreover, crystallographic data support the previously published observations that MutM enzymes are rather flexible and dynamic molecules.
Bifunctional Heterostructured Transition Metal Phosphides for Efficient Electrochemical Water Splitting
Authors: Zhang Haojie , Maijenburg A. Wouter , Li Xiaopeng , Schweizer Stefan L. , Wehrspohn Ralf B.
Published: June 2020

Reducing green hydrogen production costs is essential for developing a hydrogen economy. Developing cost‐effective electrocatalysts for water electrolysis is thus of great research interest. Among various material candidates, transition metal phosphides (TMP) have emerged as robust bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) due to their various phases and tunable electronic structure. Recently, heterostructured catalysts have exhibited significantly enhanced activities toward HER/OER. The enhancement can be attributed to the increased amount of accessible active sites, accelerated mass/charge transfer, and optimized adsorption of intermediates, which arise from the synergistic effects of the heterostructure. Herein, a comprehensive overview of the recent progress of bifunctional TMP‐based heterostructure is introduced to provide an insight into their preparation and corresponding reaction mechanisms. It starts with summarizing general fundamental aspects of HER/OER and the synergistic effect of heterostructures for enhanced catalytic activity. Next, the innovational strategies to design and construct bifunctional TMP‐based heterostructures with enhanced overall water splitting activity, as well as the related mechanisms, are discussed in detail. Finally, a summary and perspective for further opportunities and challenges are highlighted for the further development of bifunctional TMP‐based heterostructures from the points of practical application and mechanistic studies.
Understanding the Effect of Crystalline Structural Transformation for Lead‐Free Inorganic Halide Perovskites
Authors: Shi Ming , Li Guanna , Tian Wenming , Jin Shengye , Tao Xiaoping , Jiang Yiming , Pidko Evgeny A. , Li Rengui , Li Can
Published: June 2020

Lead‐free inorganic halide perovskites have triggered appealing interests in various energy‐related applications including solar cells and photocatalysis. However, why perovskite‐structured materials exhibit excellent photoelectric properties and how the unique crystalline structures affect the charge behaviors are still not well elucidated but essentially desired. Herein, taking inorganic halide perovskite Cs3Bi2Br9 as a prototype, the significant derivation process of silver atoms incorporation to induce the structural transformation from Cs3Bi2Br9 to Cs2AgBiBr6, which brings about dramatic differences in photoelectric properties is unraveled. It is demonstrated that the silver incorporation results in the co‐operated orbitals hybridization, which makes the electronic distributions in conduction and valence bands of Cs2AgBiBr6 more dispersible, eliminating the strong localization of electron–hole pairs. As consequences of the electronic structures derivation, exhilarating changes in photoelectric properties like band structure, exciton binding energy, and charge carrier dynamics are verified experimentally and theoretically. Using photocatalytic hydrogen evolution activity under visible light as a typical evaluation, such crystalline structure transformation contributes to a more than 100‐fold enhancement in photocatalytic performances compared with pristine Cs3Bi2Br9, verifying the significant effect of structural derivations on the exhibited performances. The findings will provide evidences for understanding the origin of photoelectric properties for perovskites semiconductors in solar energy conversion.
Ion Exchange Gels Allow Organic Electrochemical Transistor Operation with Hydrophobic Polymers in Aqueous Solution
Authors: Bischak Connor G. , Flagg Lucas Q. , Ginger David S.
Published: June 2020

Conjugated‐polymer‐based organic electrochemical transistors (OECTs) are being studied for applications ranging from biochemical sensing to neural interfaces. While new polymers that interface digital electronics with the aqueous chemistry of life are being developed, the majority of high‐performance organic transistor materials are poor at transporting biologically relevant ions. Here, the operating mode of an organic transistor is changed from that of an electrolyte‐gated organic field‐effect transistor (EGOFET) to that of an OECT by incorporating an ion exchange gel between the active layer and the aqueous electrolyte. This device works by taking up biologically relevant ions from solution and injecting more hydrophobic ions into the active layer. Using poly[2,5‐bis(3‐tetradecylthiophen‐2‐yl) thieno[3,2‐b]thiophene] as the active layer and a blend of an ionic liquid, 1‐butyl‐3‐methylimidazolium bis(trifluoromethylsulfonyl)imide, and poly(vinylidene fluoride‐co‐hexafluoropropylene) as the ion exchange gel, four orders of magnitude improvement in device transconductance and a 100‐fold increase in kinetics are demonstrated. The ability of the ion‐exchange‐gel OECT to record biological signals by measuring the action potentials of a Venus flytrap is demonstrated. These results show the possibility of using interface engineering to open up a wider palette of organic semiconductors as OECTs that can be gated by aqueous solutions.
Holistically Engineered Polymer–Polymer and Polymer–Ion Interactions in Biocompatible Polyvinyl Alcohol Blends for High‐Performance Triboelectric Devices in Self‐Powered Wearable Cardiovascular Monitorings
Authors: Wang Ruoxing , Mu Liwen , Bao Yukai , Lin Han , Ji Tuo , Shi Yijun , Zhu Jiahua , Wu Wenzhuo
Published: June 2020

The capability of sensor systems to efficiently scavenge their operational power from stray, weak environmental energies through sustainable pathways could enable viable schemes for self‐powered health diagnostics and therapeutics. Triboelectric nanogenerators (TENG) can effectively transform the otherwise wasted environmental, mechanical energy into electrical power. Recent advances in TENGs have resulted in a significant boost in output performance. However, obstacles hindering the development of efficient triboelectric devices based on biocompatible materials continue to prevail. Being one of the most widely used polymers for biomedical applications, polyvinyl alcohol (PVA) presents exciting opportunities for biocompatible, wearable TENGs. Here, the holistic engineering and systematic characterization of the impact of molecular and ionic fillers on PVA blends’ triboelectric performance is presented for the first time. Triboelectric devices built with optimized PVA‐gelatin composite films exhibit stable and robust triboelectricity outputs. Such wearable devices can detect the imperceptible skin deformation induced by the human pulse and capture the cardiovascular information encoded in the pulse signals with high fidelity. The gained fundamental understanding and demonstrated capabilities enable the rational design and holistic engineering of novel materials for more capable biocompatible triboelectric devices that can continuously monitor vital physiological signals for self‐powered health diagnostics and therapeutics.
Initiating a Reversible Aqueous Zn/Sulfur Battery through a “Liquid Film”
Authors: Zhao Yuwei , Wang Donghong , Li Xinliang , Yang Qi , Guo Ying , Mo Funian , Li Qing , Peng Chengxin , Li Hongfei , Zhi Chunyi
Published: June 2020

Sulfur cathodes have been under intensive study in various systems, such as Li/S, Na/S, Mg/S, and Al/S batteries. However, to date, Zn/S chemistry has never been reported. The first reliable aqueous Zn/polysulfide system activated by a “liquid film” comprising 4‐(3‐butyl‐1‐imidazolio)‐1‐butanesulfoni ionic liquid (IL) encapsulated within PEDOT:PSS. CF3SO3− anions in the IL operating as Zn2+‐transfer channels is reported. Moreover, the PEDOT:PSS network retains the IL, which renders Zn2+‐transfer channels and a polysulfide cathode with enhanced structural stability. The Zn/polysulfide system delivers extraordinary capacity of 1148 mAh g−1 and overwhelming energy density of 724.7 Wh kg−1cathode at 0.3 Ag−1. During the discharging phase, S62− is dominantly reduced by Zn to S2− (S6  →  S2−). During the charging phase, these short chains are oxidized to form long‐chain ZnxLiyS3‐6. A further optimized high‐concentrated salt electrolyte is used to improve the reversibility of the battery, demonstrating an extended lifetime over 1600 cycles at 1 Ag−1 with a capacity retention of 204 mAh g−1. This facile approach and the superior performance of the developed aqueous Zn/S chemistry provide a new platform for sulfur‐based battery and potentially solve the problems of other metal/sulfur batteries.
Analyzing Interface Recombination in Lead‐Halide Perovskite Solar Cells with Organic and Inorganic Hole‐Transport Layers
Authors: Haddad Jinane , Krogmeier Benedikt , Klingebiel Benjamin , Krückemeier Lisa , Melhem Stephanie , Liu Zhifa , Hüpkes Jürgen , Mathur Sanjay , Kirchartz Thomas
Published: June 2020

The interfaces between absorber and transport layers are shown to be critical for perovskite device performance. However, quantitative characterization of interface recombination has so far proven to be highly challenging in working perovskite solar cells. Here, methylammonium lead halide (CH3NH3PbI3) perovskite solar cells are studied based on a range of different hole‐transport layers, namely, an inorganic hole‐transport layer CuOx, an organic hole‐transport layer poly(triarylamine) (PTAA), and a bilayer of CuOx/PTAA. The cells are completed by a [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)/bathocuproine/Ag electron contact. Energy levels are characterized using photoelectron spectroscopy and recombination dynamics by combining steady‐state photoluminescence and transient photoluminescence with numerical simulations. While the PTAA‐based devices hardly show any interface recombination losses and open‐circuit voltages >1.2 V, substantial losses are observed for the samples with a direct CuOx/perovskite interface. These losses are assigned to a combination of energetic misalignment at the CuOx/perovskite interface coupled with increased interface recombination velocities at the perovskite/PCBM interface.
Blood biomarkers for vibration‐induced white fingers. A case‐comparison study
Authors: Eriksson Kåre , Burström Lage , Nilsson Tohr
Published: June 2020

Background

Vibration induced white fingers (VWF) is one form of secondary Raynaud's phenomenon (RP).

Methods

Vibration exposed workers with RP and vibration exposed controls without RP participated. Blood samples were collected before and after cold challenge exposure (COP). The concentration of von Willebrand factor (vonWf), thrombomodulin (TM), serotonin (SER), endothelin‐1 (ET1), calcitonin gene‐related peptide, or thromboxane A2 was calculated. The diagnostic usefulness of the substances for ruling in the diagnosis of Raynaud's was evaluated.

Results

The cases showed a significant lower concentration of vonWf before and after COP, a significant increase of ET1 and a decrease of TM after COP. The diagnostic usefulness of vonWf showed a likelihood of defining a true case by 35%.

Conclusions

vonWf, TM, SER, or ET1 are suggested biomarkers for VWF. Diagnostic evaluation of vonWf showed a likelihood of defining a true case by 35% in the diagnosis of RP related to vibration.
Beyond the bubble that is Robodebt: How governments that lose integrity threaten democracy
Authors: Braithwaite Valerie
Published: June 2020

Robodebt describes the automated process of matching the Australian Taxation Office's income data with social welfare recipients' reports of income to Centrelink. Discrepancies signalling benefit overpayment trigger debt notices. The scheme has been criticised for inaccurate assessment, illegality, shifting the onus of proof of debt onto welfare recipients, poor support and communication, and coercive debt collection. Beyond immediate concerns of citizen harm, Robodebt harms democratic governance. Through persisting with Robodebt, the government is launching a regulatory assault on its own integrity. Two Senate inquiries reveal government endorsing (1) incoherence and inconsistency in public engagement, (2) unsound purposes and processes and (3) disregard for citizens. Such actions destroy trustworthiness. Citizens keep their distance and as a result, cooperation falters. At particular risk is the tax system. Citizens harmed by government turn to alternative authorities for help and opportunity, not always along legitimate pathways. The underground economy provides one such opportunity for fearful welfare recipients.
Impact of Zeolite Framework Composition and Flexibility on Methanol‐To‐Olefins Selectivity: Confinement or Diffusion?
Authors: Ferri Pau , Li Chengeng , Millán Reisel , Martínez‐Triguero Joaquín , Moliner Manuel , Boronat Mercedes , Corma Avelino
Published: June 2020

The methanol‐to‐olefins reaction catalyzed by small‐pore cage‐based acid zeolites and zeotypes produces a mixture of short chain olefins, whose selectivity to ethene, propene and butene varies with the cavity architecture and with the framework composition. The product distribution of aluminosilicates and silicoaluminophosphates with the CHA and AEI structures (H‐SSZ‐13, H‐SAPO‐34, H‐SSZ‐39 and H‐SAPO‐18) has been experimentally determined, and the impact of acidity and framework flexibility on the stability of the key cationic intermediates involved in the mechanism and on the diffusion of the olefin products through the 8r windows of the catalysts has been evaluated by means of periodic DFT calculations and ab initio molecular dynamics simulations. The preferential stabilization by confinement of fully methylated hydrocarbon pool intermediates favoring the paring pathway is the main factor controlling the final olefin product distribution.
Water Oxidation with Cobalt‐Loaded Linear Conjugated Polymer Photocatalysts
Authors: Sprick Reiner Sebastian , Chen Zheng , Cowan Alexander J. , Bai Yang , Aitchison Catherine M. , Fang Yuanxing , Zwijnenburg Martijn A. , Cooper Andrew I. , Wang Xinchen
Published: June 2020

The first examples of linear conjugated organic polymer photocatalysts that produce oxygen from water after loading with cobalt and in the presence of an electron scavenger are reported. The oxygen evolution rates, which are higher than for related organic materials, can be rationalized by a combination of the thermodynamic driving force for water oxidation, the light absorption of the polymer, and the aqueous dispersibility of the relatively hydrophilic polymer particles. We also used transient absorption spectroscopy to study the best performing system and we found that fast oxidative quenching of the exciton occurs (picoseconds) in the presence of an electron scavenger, minimizing recombination.
Enantioselective Synthesis of β‐Amino Acid Derivatives Enabled by Ligand‐Controlled Reversal of Hydrocupration Regiochemistry
Authors: Guo Sheng , Zhu Jiaqi , Buchwald Stephen L.
Published: June 2020

A Cu‐catalyzed enantioselective hydroamination of α,β‐unsaturated carbonyl compounds for the synthesis of β‐amino acid derivatives was achieved through ligand‐controlled reversal of the hydrocupration regioselectivity. While the hydrocupration of α,β‐unsaturated carbonyl compounds to form α‐cuprated species has been extensively investigated, we report herein that, in the presence of an appropriate ancillary chiral ligand, the opposite regiochemistry can be observed for cinnamic acid derivatives, leading to the delivery of the copper to the β‐position. This copper can react with an electrophilic aminating reagent, 1,2‐benzisoxazole, to provide enantioenriched β‐amino acid derivatives, which are important building blocks for the synthesis of natural products and bioactive small molecules.
Ordered Solid‐State Microstructures of Conjugated Polymers Arising from Solution‐State Aggregation
Authors: Yao Ze‐Fan , Wang Zi‐Yuan , Wu Hao‐Tian , Lu Yang , Li Qi‐Yi , Zou Lin , Wang Jie‐Yu , Pei Jian
Published: June 2020

Controlling the solution‐state aggregation of conjugated polymers for producing specific microstructures remains challenging. Herein, a practical approach is developed to finely tune the solid‐state microstructures through temperature‐controlled solution‐state aggregation and polymer crystallization. High temperature generates significant conformation fluctuation of conjugated backbones in solution, which facilitates the polymer crystallization from solvated aggregates to orderly packed structures. The polymer films deposited at high temperatures exhibit less structural disorders and higher electron mobilities (up to two orders of magnitude) in field‐effect transistors, compared to those deposited at low temperatures. This work provides an effective strategy to tune the solution‐state aggregation to reveal the relationship between solution‐state aggregation and solid‐state microstructures of conjugated polymers.
New 1,2,3‐triazole–(thio)barbituric acid hybrids as urease inhibitors: Design, synthesis, in vitro urease inhibition, docking study, and molecular dynamic simulation
Authors: Asgari Mohammad S. , Azizian Homa , Nazari Montazer Mohammad , Mohammadi‐Khanaposhtani Maryam , Asadi Mehdi , Sepehri Saghi , Ranjbar Parviz R. , Rahimi Rahmatollah , Biglar Mahmood , Larijani Bagher , Amanlou Massoud , Mahdavi Mohammad
Published: June 2020

A new series of 1,2,3‐triazole–(thio)barbituric acid hybrids 8a–n was designed and synthesized on the basis of potent pharmacophores with urease inhibitory activity. Therefore, these compounds were evaluated against Helicobacter pylori urease. The obtained result demonstrated that all the synthesized compounds, 8a–n, were more potent than the standard urease inhibitor, hydroxyurea. Moreover, among them, compounds 8a, 8c–e, 8g,h, and 8k,l exhibited higher urease inhibitory activities than the other standard inhibitor used: thiourea. Docking studies were performed with the synthesized compounds. Furthermore, molecular dynamic simulation of the most potent compounds, 8e and 8l, showed that these compounds interacted with the conserved residues Cys592 and His593, which belong to the active site flap and are essential for enzymatic activity. These interactions have two consequences: (a) blocking the movement of a flap at the entrance of the active site channel and (b) stabilizing the closed active site flap conformation, which significantly reduces the catalytic activity of urease. Calculation of the physicochemical and topological properties of the synthesized compounds 8a–n predicted that all these compounds can be orally active. The ADME prediction of compounds 8a–n was also performed.
MoS2 quantum dots as a specific fluorescence sensor for selection of rutin and for temperature sensing
Authors: Sun Yunyun , He Wei , Sun Xiangying , Liu Bin
Published: June 2020

A selective and sensitive method for detecting rutin using MoS2 quantum dots (QDs) as a fluorescent probe is reported in the paper, a one‐step hydrothermal synthesis method was used to prepare MoS2 QDs. The synthesized MoS2 QDs had good stability and water solubility, and the fluorescence of MoS2 QDs was quenched by rutin due to the inner filter effect. There was a good linear relationship between the intensity of MoS2 QDs and rutin concentration ranging from 5.0 × 10−7 to 3.2 × 10−5 mol/L with a detection limit of 3.5 × 10−7 mol/L. MoS2 QDs showed temperature‐dependent fluorescence that had an excellent linear relationship between 20 and 80°C. Therefore MoS2 QDs can be used as specific fluorescence sensors for selection of rutin and for temperature sensing.
Enrichment of flavonoid‐rich extract from Bidens bipinnata L. by macroporous resin using response surface methodology, UHPLC–Q‐TOF MS/MS‐assisted characterization and comprehensive evaluation of its bioactivities by analytical hierarchy process
Authors: Yang Xiudong , Bai Zi‐Fan , Zhang Da‐Wei , Zhang Yan , Cui Hao , Zhou Hong‐Li
Published: June 2020

The extract of Bidens bipinnata L. exhibited wide spectrum of bioactivities owing to the presence of flavonoids. In this study, a purification process was developed to enrich the flavonoid‐rich extract from B. bipinnata L. (BBTF). AB‐8 resin was selected for the purification of total flavonoids. Response surface methodology coupled with Box–Behnken design was employed to optimize the purification condition; it was optimized as pH 5.1, volume of ethanol 80 ml, flow rate of ethanol 1.8 bed volume per hour (BV/h) and concentration of ethanol 76.0%. The total flavonoid content of BBTF was 56.48% under the optimal conditions. The identification of flavonoids in BBTF was conducted using UHPLC–ESI‐Q‐TOF MS. A total of 14 compounds, including 12 flavonoids, were identified in BBTF. Finally, the in vitro antioxidant activities, α‐glucosidase and α‐amylase inhibitory activities of BBTF were comprehensively analyzed by an analytical hierarchy process. The results indicated that it exhibited higher bioactivities than the crude extract. These findings suggested that the optimized process could significantly enhance the purity of flavonoids and their bioactivities. This study showed a comprehensive analysis of a total flavonoid extract of B. bipinnata L. for the first time, which could provide a useful approach for its purification process and quality control as well as bioactivities.
Implementation of Activated Sludge Model No. 3 as an educational tool: bioXL3
Authors: Demir Selami , Manav Demir Neslihan
Published: June 2020

Implementation of an Microsoft (MS) Excel add‐in, called bioXL3, is presented in this paper. bioXL3 is an educational tool for undergraduate‐ and graduate‐level education in the environmental engineering field. The add‐in is an open‐source tool and is used for the simulation of conventional biological wastewater treatment plants based on Activated Sludge Model No. 3. The software is developed using visual basic for applications (VBA) in MS Excel and is tested with a number of sample model setups. All formulations used in VBA programming are provided here. Also, simulation results of a sample predenitrification system are summarized. The performance of the software in engineering education was tested by a teaching session. Results indicated that the add‐in can prove useful in undergraduate and graduate‐level education in environmental engineering.
Synthesis and Evaluation of Anticonvulsant Activity of Some Schiff Bases of 7‐Amino‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one
Authors: Nilkanth Pankaj R. , Ghorai Sujit K. , Sathiyanarayanan Arulmozhi , Dhawale Kiran , Ahamad Tansir , Gawande Manoj B. , Shelke Sharad N.
Published: June 2020

A variety of 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethines and 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one benzamide were prepared, characterized and evaluated for the anticonvulsant activity in the rat using picrotoxin‐induced seizure model. The prepared 1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one azomethine derivatives emerged potentially anticonvulsant molecular scaffolds exemplified by compounds, 7‐{(E)‐[(4‐nitrophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, 7‐{(E)‐[(4‐bromo‐2,6‐difluorophenyl)methylidene]amino}‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one and 7‐[(E)‐{[3‐(4‐fluorophenyl)‐1‐phenyl‐1H‐pyrazol‐4‐yl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one. All these four compounds have shown substantial decrease in the wet dog shake numbers and grade of convulsions with respect to the standard drug diazepam. The most active compound, 7‐[(E)‐{[4‐(dimethylamino)phenyl]methylidene}amino]‐5‐phenyl‐1,3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one, exhibited 74 % protection against convulsion which was higher than the standard drug diazepam. Furthermore, to identify the binding mode of the interaction amongst the target analogs and binding site of the benzodiazepine receptor, molecular docking study and molecular dynamic simulation were carried out. Additionally, in silico pharmacokinetic and toxicity predictions of target compounds were carried out using AdmetSAR tool. Results of ADMET studies suggest that the pharmacokinetic parameters of all the target compounds were within the acceptable range to become a potential drug candidate as antiepileptic agents.
Efficient Chemoenzymatic Synthesis of N‐Glycans with a β1,4‐Galactosylated Bisecting GlcNAc Motif
Authors: Weiss Michael , Ott Dimitri , Karagiannis Theodoros , Weishaupt Markus , Niemietz Mathäus , Eller Steffen , Lott Marie , Martínez‐Orts Mónica , Canales Ángeles , Razi Nahid , Paulson James C. , Unverzagt Carlo
Published: June 2020

In human serum immunoglobulin G (IgG), a rare modification of biantennary complex N‐glycans lead to a β1,4‐galactosylated bisecting GlcNAc branch. We found that the bisecting GlcNAc on a biantennary core‐fucosylated N‐glycan was enzymatically galactosylated under stringent reaction conditions. Further optimizations led to an efficient enzymatic approach to this particular modification for biantennary substrates. Notably, tri‐ and tetra‐antennary complex N‐glycans were not converted by bovine galactosyltransferase. An N‐glycan with a galactosylated bisecting GlcNAc was linked to a lanthanide binding tag. The pseudo‐contact shifts (PCS) obtained from the corresponding Dy‐complex were used to calculate the conformational preferences of the rare N‐glycan. Besides two extended conformations only a single folded conformation was found.
Phrenic nerve injury secondary to extracorporeal membrane oxygenation in pregnancy: A case report
Authors: Godcharles Cheryl , Safarzadeh Melody , Oliver Emily A. , Roman Amanda , Al‐Kouatly Huda B.
Published: June 2020

Extracorporeal membrane oxygenation (ECMO) is used to provide acute respiratory and/or hemodynamic support to patients with severe, refractory respiratory failure. Phrenic nerve injury with subsequent hemidiaphragm paralysis should be included in the differential diagnosis of pregnant women with persistent hypoxia after ECMO cannulation.
Simultaneous Detection of Quercetin and Carbendazim in Wine Samples Using Disposable Electrochemical Sensors
Authors: Raymundo‐Pereira Paulo A. , Gomes Nathalia O. , Carvalho Jefferson H. S. , Machado Sergio A. S. , Oliveira Osvaldo N. , Janegitz Bruno C.
Published: June 2020

Developing low‐cost and fast methods for on‐site analysis is a long‐sought goal of the wine industry, especially to detect excessive concentrations of naturally occurring compounds such as polyphenols and pesticide residues. In this paper, we report on the treatment of screen‐printed electrodes, which were capable of detecting the flavonoid quercetin and the pesticide carbendazim simultaneously in wine samples with limits of detection of 51.8×10−9 mol L−1 and 60×10−9 mol L−1, respectively. Furthermore, no significant interference was observed with electroactive substances that can co‐exist in wine. We found that the electrochemical pretreatment in Na2CO3 solution eliminated residues and impurities from homemade carbon ink comprising graphite and alkyd resin eventually deposited on the electrodes, which were characterized by combining scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. These findings pave the way for monitoring multiple analytes with screen‐printed electrodes, which could be extended to clinical biomarkers.
Rapid Discrimination of Crystal Handedness by X‐ray Natural Circular Dichroism (XNCD) Mapping
Authors: Cortijo Miguel , Valentín‐Pérez Ángela , Rogalev Andrei , Wilhelm Fabrice , Sainctavit Philippe , Rosa Patrick , Hillard Elizabeth A.
Published: June 2020

An original method for determining the handedness of individual non‐centrosymmetric crystals in a mixture using a tightly‐focused, circularly polarized X‐ray beam is presented. The X‐ray natural circular dichroism (XNCD) spectra recorded at the metal K‐edge on selected crystals of [Δ‐M(en)3](NO3)2 and [Λ‐M(en)3](NO3)2 (M=CoII, NiII) show extrema at the metal pre‐edge (7712 eV for Co, 8335 eV for Ni). A mapping of a collection of some 220 crystals was performed at the respective energies by using left and right circular polarizations. The difference in absorption for the two polarizations, being either negative or positive, directly yielded the handedness of the crystal volume probed by the beam. By using this technique, it was found that the addition of l‐ascorbic acid during the synthesis of [Co(en)3](NO3)2 resulted in an enantiomeric enrichment of the Λ‐isomer of 67±13 %, whereas the Ni analogue was similarly, but conversely, enriched in the Δ‐isomer (65±22 %).
Pseudocapacitive Lithium Storage of Cauliflower‐Like CoFe2O4 for Low‐Temperature Battery Operation
Authors: Fan Honghong , Bahmani Farzaneh , Kaneti Yusuf Valentino , Guo Yanna , Alothman Asma A. , Wu Xinglong , Yamauchi Yusuke , Li Wenliang , Zhang Jingping
Published: June 2020

Binary transition‐metal oxides (BTMOs) with hierarchical micro–nano‐structures have attracted great interest as potential anode materials for lithium‐ion batteries (LIBs). Herein, we report the fabrication of hierarchical cauliflower‐like CoFe2O4 (cl‐CoFe2O4) via a facile room‐temperature co‐precipitation method followed by post‐synthetic annealing. The obtained cauliflower structure is constructed by the assembly of microrods, which themselves are composed of small nanoparticles. Such hierarchical micro–nano‐structure can promote fast ion transport and stable electrode–electrolyte interfaces. As a result, the cl‐CoFe2O4 can deliver a high specific capacity (1019.9 mAh g−1 at 0.1 A g−1), excellent rate capability (626.0 mAh g−1 at 5 A g−1), and good cyclability (675.4 mAh g−1 at 4 A g−1 for over 400 cycles) as an anode material for LIBs. Even at low temperatures of 0 °C and −25 °C, the cl‐CoFe2O4 anode can deliver high capacities of 907.5 and 664.5 mAh g−1 at 100 mA g−1, respectively, indicating its wide operating temperature. More importantly, the full‐cell assembled with a commercial LiFePO4 cathode exhibits a high rate performance (214.2 mAh g−1 at 5000 mA g−1) and an impressive cycling performance (612.7 mAh g−1 over 140 cycles at 300 mA g−1) in the voltage range of 0.5–3.6 V. Kinetic analysis reveals that the electrochemical performance of cl‐CoFe2O4 is dominated by pseudocapacitive behavior, leading to fast Li+ insertion/extraction and good cycling life.
Temperature Induced Aggregation of Organic Semiconductors
Authors: Du Baocai , Yi Jicheng , Yan He , Wang Tao
Published: June 2020

One important feature of organic semiconductors is their solution processability, which allows researchers to tune their aggregation states in solution and solid states and to control the processing conditions to reach desirable electronic and optoelectronic properties. Temperature is one of the most important processing parameters of organic semiconductors and has been studied extensively particularly for those conjugated small‐ and macro‐ molecules with strong temperature‐dependent aggregation properties. This minireview summarizes the temperature‐induced aggregation behaviors of organic semiconductors in solution, during solution casting and upon thermal annealing post‐treatment of solid‐state thin films. The influences of different aggregation states on the optoelectronic properties, in particular the photovoltaic properties, are discussed. The conclusions in this work will provide a rational guide to precisely control the aggregation states of organic semiconductors to fabricate high‐performance optoelectronic devices.
Nickel‐Catalyzed Amination of (Hetero)aryl Halides Facilitated by a Catalytic Pyridinium Additive
Authors: Han Dongyang , Li Sasa , Xia Siqi , Su Mincong , Jin Jian
Published: June 2020

An efficient and operationally simple Ni‐catalyzed amination protocol has been developed. This methodology features a simple NiII salt, an organic base and catalytic amounts of both a pyridinium additive and Zn metal. A diverse number of (hetero)aryl halides were coupled successfully with primary and secondary alkyl amines, and anilines in good to excellent yields. Similarly, benzophenone imine gave the corresponding N‐arylation product in an excellent yield.
Improved region convolutional neural network for ship detection in multiresolution synthetic aperture radar images
Authors: Xiao Qilin , Cheng Yun , Xiao Minlei , Zhang Jun , Shi Hongji , Niu Lihui , Ge Chenguang , Lang Haitao
Published: June 2020

Effectively obtaining the location and direction of the ship target is an important prerequisite for maritime traffic management and marine accident rescue. Thanks to the rapid development of the target detection methods based on deep learning, this article proposed a ship target detection method for multiresolution synthetic aperture radar (SAR) images based on improved region convolution neural network (R‐CNN). According to the characteristics of ship target in the SAR images, we make several improvements such as enlarging the input, proposal optimization, database target categorization, and weight balance on the basis of the standard Faster R‐CNN. The experimental results proved that the proposed method can detect target effectively and precisely in complicated scenes of multiresolution SAR images, such as in‐shore and dense targets. It has a good potential in practical application.
Searchable encryption scheme for multiple cloud storage using double‐layer blockchain
Authors: Fu Shaojing , Zhang Chao , Ao Weijun
Published: June 2020

With the emergence of cloud storage security, how to ensure the security of cloud storage has become a research focus. The typical searchable encryption model consists of a single cloud service provider and has some unsolvable drawbacks. In this article, a new searchable encryption scheme in multi‐cloud was proposed based on blockchain. We first define a system model in multiple clouds and combine multiple cloud service providers to store data through a consortium chain. Then we store the encrypted documents and indexes in The Interplanetary File System (IPFS) and store the hash value and IPFS address of the documents in the blockchain. Our scheme can provide outsourced encrypted data retrieval based on multiple keywords, as well as verification schemes for the integrity of retrieved files. The theoretical analysis and experiments on real‐world data show the security and high performance of our scheme.
Sentiment analysis on product reviews based on weighted word embeddings and deep neural networks
Authors: Onan Aytuğ
Published: June 2020

Sentiment analysis is one of the major tasks of natural language processing, in which attitudes, thoughts, opinions, or judgments toward a particular subject has been extracted. Web is an unstructured and rich source of information containing many text documents with opinions and reviews. The recognition of sentiment can be helpful for individual decision makers, business organizations, and governments. In this article, we present a deep learning‐based approach to sentiment analysis on product reviews obtained from Twitter. The presented architecture combines TF‐IDF weighted Glove word embedding with CNN‐LSTM architecture. The CNN‐LSTM architecture consists of five layers, that is, weighted embedding layer, convolution layer (where, 1‐g, 2‐g, and 3‐g convolutions have been employed), max‐pooling layer, followed by LSTM, and dense layer. In the empirical analysis, the predictive performance of different word embedding schemes (ie, word2vec, fastText, GloVe, LDA2vec, and DOC2vec) with several weighting functions (ie, inverse document frequency, TF‐IDF, and smoothed inverse document frequency function) have been evaluated in conjunction with conventional deep neural network architectures. The empirical results indicate that the proposed deep learning architecture outperforms the conventional deep learning methods.
Morphological and Interaction Characteristics of Surface‐Active Ionic Liquids and Palmitic Acid in Mixed Monolayers
Authors: Eftaiha A. F. , Qaroush Abdussalam K. , Kayed Ghada G. , Abdel Rahman Abdel Rahman K. , Assaf Khaleel I. , Paige Matthew F.
Published: June 2020

A series of water soluble, surface‐active ionic liquids (SAILs), namely, 1‐alkyl‐3‐methyl imidazolium chlorides ([Cn‐mim]Cl) and their mixtures with palmitic acid (PA) are investigated in Langmuir monolayers and Langmuir–Blodgett films. It is inferred from the surface pressure‐area isotherms that C16‐mim‐IL mixes non‐ideally with PA and stabilizes the binary mixed films. In addition, the residence of mim‐IL at the water surface is enhanced as a function of the increasing alkyl side chain length. Generally, the compressional moduli values decrease upon increasing the content of the mim‐ILs over a wide range of compositions. Furthermore, film relaxation measurements indicate that the IL component is selectively excluded from the mixed films upon achieving a certain target pressure. Brewster angle microscope images demonstrate minimal changes on the PA domains in the presence of either C4‐ and C8‐mim‐ILs, whereas presence of the hexadecyl counterpart results in the formation of condensed sheets. Atomic force microscopy imaging of deposited films show the formation of propeller‐like aggregates when C8‐ or C16‐mim‐IL is present in the mixed films.
Gas Phase Formation of Methylgermylene (HGeCH3)
Authors: Yang Zhenghai , He Chao , Doddipatla Srinivas , Krasnoukhov Vladislav S. , Azyazov Valeriy N. , Mebel Alexander M. , Kaiser Ralf I.
Published: June 2020

The methylgermylene species (HGeCH3; X1A′) has been synthesized via the bimolecular gas phase reaction of ground state methylidyne radicals (CH) with germane (GeH4) under single collision conditions in crossed molecular beams experiments. Augmented by electronic structure calculations, this elementary reaction was found to proceed through barrierless insertion of the methylidyne radical in one of the four germanium‐hydrogen bonds on the doublet potential energy surface yielding the germylmethyl (CH2GeH3; X2A′) collision complex. This insertion is followed by a hydrogen shift from germanium to carbon and unimolecular decomposition of the methylgermyl (GeH2CH3; X2A′) intermediate by atomic hydrogen elimination leading to singlet methylgermylene (HGeCH3; X1A′). Our investigation provides a glimpse at the largely unknown reaction dynamics and isomerization processes of the carbon‐germanium system, which are quite distinct from those of the isovalent carbon system thus providing insights into the intriguing chemical bonding of organo germanium species on the most fundamental, microscopic level.
Selective Hydrogenation of Biomass‐Derived Furfural: Enhanced Catalytic Performance of Pd−Cu Alloy Nanoparticles in Porous Polymer
Authors: Salnikova Ksenia E. , Larichev Yurii V. , Sulman Esther M. , Bykov Alexey V. , Sidorov Alexander I. , Demidenko Galina N. , Sulman Mikhail G. , Bronstein Lyudmila M. , Matveeva Valentina G.
Published: June 2020

Here, the development of a new catalyst is reported for the selective furfural (FF) hydrogenation to furfuryl alcohol (FA) based on about 7 nm sized Pd−Cu alloy nanoparticles (NPs) formed in inexpensive, commercially available micro/mesoporous hypercrosslinked polystyrene (HPS). A comparison of the catalytic properties of as‐synthesized and reduced (denoted “r”) catalysts as well as Pd−Cu alloy and monometallic palladium NPs showed a considerable enhancement of the catalytic performance of Pd−Cu/HPS‐r compared to other catalysts studied, resulting in about 100 % FF conversion, 95.2 % selectivity for FA and a TOF of 1209 h−1. This was attributed to the enrichment of the NP surface with copper atoms, disrupting the furan ring adsorption, and to the presence of both zerovalent and cationic palladium and copper species, resulting in optimal hydrogen and FF adsorption. These factors along with exceptional stability of the catalyst in ten consecutive catalytic cycles make it highly promising in practical applications.