bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversing the Enantioselectivity of Enzymatic Carbene N−H Insertion Through Mechanism‐Guided Protein Engineering**
Authors: Calvó‐Tusell Carla , Liu Zhen , Chen Kai , Arnold Frances H. , Garcia‐Borràs Marc
Published: June 2023

We report a computationally driven approach to access enantiodivergent enzymatic carbene N−H insertions catalyzed by P411 enzymes. Computational modeling was employed to rationally guide engineering efforts to control the accessible conformations of a key lactone‐carbene (LAC) intermediate in the enzyme active site by installing a new H‐bond anchoring point. This H‐bonding interaction controls the relative orientation of the reactive carbene intermediate, orienting it for an enantioselective N‐nucleophilic attack by the amine substrate. By combining MD simulations and site‐saturation mutagenesis and screening targeted to only two key residues, we were able to reverse the stereoselectivity of previously engineered S‐selective P411 enzymes. The resulting variant, L5_FL‐B3, accepts a broad scope of amine substrates for N−H insertion with excellent yields (up to >99 %), high efficiency (up to 12 300 TTN), and good enantiocontrol (up to 7 : 93 er).
Enantio‐ and Diastereoselective Synthesis of Chiral Tetrasubstituted α‐Amino Allenoates Bearing a Vicinal All‐Carbon Quaternary Stereocenter with Dual‐Copper‐Catalysis
Authors: Sheng Cheng , Ling Zheng , Xiao Junzhe , Yang Kai , Xie Fang , Ma Shengming , Zhang Wanbin
Published: June 2023

The skeletons of chiral tetrasubstituted allenes bearing a vicinal all‐carbon quaternary stereocenter are of importance but still challenging to synthesize. Herein, we report enantio‐ and diastereoselective γ‐additions of 1‐alkynyl ketimines with dual‐copper‐catalysis under mild conditions, affording chiral tetrasubstituted α‐amino allenoates bearing a vicinal all‐carbon quaternary stereocenter in high yields (up to 99 % yield) with excellent enantioselectivities (up to 99 % ee) and diastereoselectivities (up to >20 : 1 dr). Importantly, the stereodivergent synthesis of the products was realized by the asymmetric γ‐addition reaction and the Grignard reagent promoted epimerization. Moreover, the dual‐copper‐catalyzed γ‐addition reactions were smoothly applied to a gram‐scale reaction and adopted to introduce chiral tetrasubstituted allenyl moieties into bioactive molecules. Mechanistic experiments and density functional theory (DFT) calculations demonstrated that the asymmetric γ‐addition reactions were catalyzed by double chiral copper catalysts.
Copper (I)‐BOX Catalyzed Asymmetric 3‐Component Reaction for the Synthesis of Trifluoromethylated Propargylic Ethers and Anilines**
Authors: Ramirez Nieves P. , Waser Jerome
Published: June 2023

An asymmetric 3‐component reaction between EthynylBenziodoXoles (EBXs), 2,2,2‐trifluorodiazoethane and nucleophiles catalyzed by a CuI‐BOX (Bisoxazoline) catalyst is described. This protocol gives access to chiral trifluoromethylated propargyl ethers and anilines, which are valuable building blocks in synthetic and medicinal chemistry. The reaction proceeds with high enantioselectivity and yield with different nucleophiles such as primary, secondary and tertiary alcohols, as well as both electron‐rich and electron‐poor anilines. Aryl‐, alkyl‐ and silyl‐substituted alkynes can be successfully introduced as electrophiles. In case of chiral substrates, high catalyst control was observed, leading to good diastereoselectivity.
A Photosensitizing Metal–Organic Framework as a Tandem Reaction Catalyst for Primary Alcohols from Terminal Alkenes and Alkynes
Authors: Lin Xiao‐Chun , Wang Yu‐Mei , Chen Xu , You Pei‐Ye , Mo Kai‐Ming , Ning Guo‐Hong , Li Dan
Published: June 2023

Owing to the wide and growing demand for primary alcohols, the development of efficient catalysts with high regioselectivity remains a worthwhile pursuit. However, according to Markovnikov's rule, it is a challenge to obtain primary alcohols with high yields and regioselectivity from terminal alkenes or alkynes. Herein, we report the synthesis of a photosensitizing two‐dimensional (2D) metal–organic framework (MOF) from cyclic trinuclear copper(I) units (Cu‐CTUs) and a boron dipyrro‐methene (Bodipy) ligand. The MOF features broadband light absorption, excellent photoinduced charge separation efficiency, and photochemical properties. By integrating the copper‐catalyzed hydroboration and photocatalyzed aerobic oxidation, it can catalyze terminal alkenes and alkynes to produce primary alcohols via a one‐pot tandem reaction with excellent regioselectivity, good overall yields in two‐step reactions (up to 85 %), broad substrate compatibility (32 examples) and good reusability under mild conditions.
Perovskite Scintillators for Improved X‐ray Detection and Imaging
Authors: Wang Yumin , Li Ming , Chai Zhifang , Wang Yaxing , Wang Shuao
Published: June 2023

Halide perovskites (HPs) recently have emerged as one class of competitive scintillators for X‐ray detection and imaging owing to its high quantum efficiency, short decay time, superior X‐ray absorption capacity, low cost, and ease of crystal growth. The tunable structure and versatile chemical compositions of halide perovskites provide distinguishable advantages over traditional inorganic scintillators for optimizing scintillation performance. Since the first observation of the scintillation phenomenon in HPs, substantial efforts have been devoted to expanding the inventory of HP scintillators and regulating material properties. Understanding the relationship between the structure and scintillation properties of HP scintillators is essential for developing materials with improved X‐ray detection and imaging capacities. This review summarizes strategies for improving the light yield of HP scintillators and provides a roadmap for improving the X‐ray imaging performance. Additionally, methods for controlling the light propagation direction in HP scintillators are highlighted for improving X‐ray imaging resolution. Finally, we highlight the current challenge in HP scintillators and provide a perspective on the future development of this emerging scintillator.
Size‐Transformable Superoxide‐Triggered Nanoreporters for Crosstalk‐Free Dual Fluorescence/Chemiluminescence Imaging and Urinalysis in Living Mice
Authors: Ruan Bankang , Yu Mengya , Zhou Ya , Xu Weiping , Liu Yi , Liu Biaoxiang , Zhu Lijuan , Yi Shujuan , Jiang Yuyan , Huang Jiaguo
Published: June 2023

Chemiluminescence imaging has been recognized as a valuable tool for ultrasensitive detection of physio‐pathological events through elimination of background autofluorescence. However, most chemiluminescent nanoprobes suffer from shallow imaging depths and slow clearance from living bodies, which impede their use in clinical settings. We herein report size‐transformable nanoreporters (ADN1 and ADN2) that could be activated at disease site by superoxide anion (O2⋅−) to trigger nanostructure disassembly into renal excretable fluorescent fragments as well as chemiluminescence turn‐on for crosstalk‐free duplex chemo‐fluorescence imaging and in vitro urinalysis. In peritonitis mouse model, we demonstrate that the representative nanoreporter ADN1 spontaneously accumulates at the disrupted peritoneum and is cleaved by upregulated O2⋅− to initiate depolymerization and result in red chemiluminescence at 620 nm, enabling sensitive detection of peritonitis at least 19 h earlier than gold standard histological assays. Additionally, the incorporation of a near‐infrared (NIR) dye into ADN1 results in ADN2 exhibiting intense and red‐shifted chemiluminescence at ≈800 nm, which permits early detection of deeply seated diseases such as drug‐induced hepatotoxicity. This study thus showcases a modular design strategy that is not only applicable to developing versatile chemiluminescent nanoprobes with switchable pharmacokinetics for early disease diagnosis, but also promising for future clinical translations.
Engineered polysaccharide alpha‐1,3‐glucan in highly filled thermoplastic polyurethane systems
Authors: Kim James , Qudsi Yazan H. , Mok Jorge , Lenges Christian , Simon Leonardo
Published: June 2023

This study explores the use of α‐1,3‐glucan, which can be produced through an enzymatic polymerization process, as additive for thermoplastic polyurethane composite systems. Most importantly, highly filled thermoplastic polyurethane composites can be achieved with up to 80% by weight polysaccharide content. Analysis of mechanical properties demonstrates that strength and modulus can be significantly improved, while the plasticizer content allows for adjustments of compound flexibility. The addition of 60% α‐1,3‐glucan increased the flexural modulus of the thermoplastic polyurethane by 497% while adding 80% α‐1,3‐glucan increased the flexural modulus by 3193%. Citrate esters can be incorporated as plasticizer to improve processibility and flexibility of the compounds. An increase in impact strength of 55% was achieved when 10% of tributyl citrate was added to the 80% α‐1,3‐glucan composite. Based on the compatibility and property enhancements, the use of these engineered polysaccharides may provide additional options for producing sustainable composite materials with high renewable content and unique properties.
Study on the effect of layered double hydroxide on the mechanical and thermal properties of nitrile butadiene rubber
Authors: Wang XIaosen , Zhang Yanbin , Li Kangshuai , Kang Qianrui , He Qiang
Published: June 2023

Nitrile rubber is a widely used rubber, so its basic mechanical properties are very important. In order to improve the mechanical properties of nitrile butadiene rubber (NBR), Mg‐Al hydrotalcite was introduced into NBR by mechanical blending and hot pressing, and the mechanical properties of the composites were studied. The results show that, compared with NBR, the maximum MH‐ML of 2%LDH/NBR composites reaches 1.795 N·m, and an is improved by 8.7%. The T90 of NBR and 2%LDH/NBR composites insignificant changed. In terms of mechanical performance, the optimal performance is achieved when two parts of layered double hydroxide (LDH) are added. Compared with the original NBR, the tensile elongation at break, tear strength, and 100% modulus stress increased by 11.6%, 7.1%, and 29.1%, respectively. The addition of LDH also has a certain influence on the thermal conductivity of the composites. Compared with the original NBR, the peak thermal conductivity of NBR with two parts of LDH increased by 2.4 mW. Under the condition of low filling, the mechanical properties such as elongation at break and tear strength of LDH/NBR composites have been improved, which provides a reference for the development of mechanical properties research of NBR.
Information misbehavior: How organizations use information to deceive
Authors: Choo Chun Wei , Meyer Marco
Published: June 2023

Recent examples of organizational wrongdoing such as those that led to the opioid crisis and the 2008 financial meltdown show that organizations can deliberately use information to deceive others, resulting in serious harm. This brief communication explores the role of information in organizational wrongdoing. We analyze a dataset consisting of 80 cases of high‐penalty corporate wrongdoing in the United States in the period 2000–2020. Our analysis of documents filed by the US Department of Justice and federal regulatory agencies in those cases found that organizations use two general information strategies to deceive and mislead. First, organizations can “sow doubt” on statements by others that hurt the organization's interests. Second, organizations can “exploit trust” that others have placed in them to provide truthful information. Our analysis suggests that which strategy is adopted depends on the degree that the organization's external information use environment is “contested” or “controlled.” Across the cases examined, we observe three types of information behaviors that implement the strategy of sowing doubt and exploiting trust: information obfuscation, information concealment, and information falsification.
Elucidating Degradation Mechanisms of Silicon‐graphite Electrodes in Lithium‐ion Batteries by Local Electrochemistry
Authors: Jiyane Nomnotho , García‐Quismondo Enrique , Ventosa Edgar , Schuhmann Wolfgang , Santos Carla Santana
Published: June 2023

The integrity of the solid electrolyte interphase (SEI) formed on the negative electrode of lithium‐ion batteries (LIB) is especially critical for the performance of next‐generation LIBs comprising silicon‐carbon based electrode materials. The protecting character of the SEI is compromised due to volume expansion and shrinking during de/intercalation of Li ions leading to irreversible changes upon long‐term cycling. Scanning electrochemical microscopy (SECM) is proposed as local electrochemical technique to investigate the degradation mechanisms of advanced negative electrodes. The impact of charge/discharge cycling on the SEI properties on Si−C electrodes was investigated, and the sensitivity of SECM successfully reveals inhomogeneities at an early stage of the cycling already at about 5 cycles. Macroscopic EIS measurements and evaluation of the coulombic efficiency may result in misleading interpretations of degradation. SECM is demonstrated to be a powerful and complementary technique for revealing μm‐heterogeneities in the SEI surface reactivity after a few charge/discharge cycles.
Synthesis, antioxidant, and molecular docking of new fluorescent (4‐alkoxyphenyl)‐nitrothiophene compounds
Authors: Miled Wafa , Abomuti May Abdullah , Alotaibi Fatimah A. , Alhadhrami Nahlah A. , Zghab Imen
Published: June 2023

New fluorescent 4‐alkoxyphenyl‐nitrothiophene compounds 4a–d bearing diverse alkoxyl tails are described. The synthetic strategy was simply accomplished by alkali‐assisted alkylation of 4‐(5‐nitrothiophen‐2‐yl)phenol (3) with propyl, hexyl, nonyl, and/or dodecyl iodide. The molecular structures were determined using infrared (IR), 1H NMR, and mass spectroscopy. Ultraviolet–visible (UV–vis) absorption and emission spectra of the produced 4‐alkoxyphenyl‐nitrothiophenes revealed considerable extinction coefficients, which were shown to be controlled by the thiophene bridge in conjugation with the alkoxy donor moiety. It was found that the maximum absorbance wavelength was affected by the alkoxyl group‐bonded substituents. The antioxidant efficiency obtained from the 4‐alkoxyphenyl‐nitrothiophene hybrids was excellent compared with that widely used drugs [butylated hydroxytoluene (BHT) and vitamin C]. Unlike 2‐(4‐[dodecyloxy]phenyl)‐5‐nitrothiophene hybrid 4d, which has made solid claims about the good effect of its reference drugs and vitamins, Docking investigations of the prepared 4‐alkoxyphenyl‐nitrothiophene hybrids towards the selected 5IKQ protein revealed impressive coordination and antioxidant effectiveness.
Experimental and theoretical investigations of rotating algae biofilm reactors (RABRs): Areal productivity, nutrient recovery, and energy efficiency
Authors: Jones Gerald Benjamin , Sims Ronald C. , Zhao Jia
Published: June 2023

Microalgae biofilms have been demonstrated to recover nutrients from wastewater and serve as biomass feedstock for bioproducts. However, there is a need to develop a platform to quantitatively describe microalgae biofilm production, which can provide guidance and insights for improving biomass areal productivity and nutrient uptake efficiency. This paper proposes a unified experimental and theoretical framework to investigate algae biofilm growth on a rotating algae biofilm reactor (RABR). Experimental laboratory setups are used to conduct controlled experiments on testing environmental and operational factors for RABRs. We propose a differential–integral equation‐based mathematical model for microalgae biofilm cultivation guided by laboratory experimental findings. The predictive mathematical model development is coordinated with laboratory experiments of biofilm areal productivity associated with ammonia and inorganic phosphorus uptake by RABRs. The unified experimental and theoretical tool is used to investigate the effects of RABR rotating velocity, duty cycle (DC), and light intensity on algae biofilm growth, areal productivity, nutrient uptake efficiency, and energy efficiency in wastewater treatment. Our framework indicates that maintaining a reasonable light intensity range improves biomass areal productivity and nutrient uptake efficiency. Our framework also indicates that faster RABR rotation benefits biomass areal productivity. However, maximizing the nutrient uptake efficiency requires a reasonably low RABR rotating speed. Energy efficiency is strongly correlated with RABR rotating speed and DC.
Lignin‐based materials for the detection and adsorption of metal ions
Authors: Lee Sumin , Koo Byungjin
Published: June 2023

Upcycling low‐valued materials and/or biobased wastes is a promising method to produce materials in an energy‐saving, sustainable way. Lignin is one of the underutilized biomasses and has been produced as a byproduct in paper‐making industry. Upcycling lignin into valuable products is key to solving problems associated with waste disposal, environmental pollution, and depletion of natural resources. One way to add values to lignin and its derivatives is to utilize them as sensors and adsorbents, in which toxic elements and materials can be detected and removed. In this review, we highlight the utility of lignin in the field of sensing and adsorbing metal ions. This review begins with the general overview of lignin as materials, followed by investigation of lignin and its derivatives in the detection and removal of metal ions. Lastly, we end this review with the prospects of lignin as sensors and adsorbents.
Exploring business stakeholder engagement in sustainable business practices: Evidence from the US pet amphibian industry
Authors: Cavasos Kevin , Poudyal Neelam C. , Brunner Jesse L. , Warwick Alexa R. , Jones Joshua , Moherman Neil , George Mark , Willard Joshua D. , Brinks Zachary T. , Gray Matthew J.
Published: June 2023

The recent decline in wild populations of amphibians worldwide coincides with the period of rapid growth in the global trade of wildlife. The potential for pathogen transmission within and beyond the pet amphibian trade network makes it important to explore the attitudes and behavior of businesses involved in the industry. We surveyed US businesses involved in the pet amphibian trade industry to characterize their attitudes and behaviors and identify business characteristics that could influence percieved risk of pathogen transmission in trade. We found that amphibian businesses acquire their animals from a variety of sources (e.g., importers, wholesalers, retailers, breeders, hobbyists, wild), are aware of the threat of emerging pathogens, and are concerned about the potential spillover of pathogens from captive to wild populations. Attitudes and behaviors of businesses toward pathogens varied among business types (e.g., size of business, the share of amphibian sales, mode of business operation). Moreover, businesses expressed a strong interest in acquiring amphibians that are free of pathogens and indicated a willingness to pay a price premium to acquire certified disease‐free animals. Our results indicate that the US pet amphibian trade industry is willing to participate in healthy (clean) trade practices and increasing product prices may be one option to compensate for expenses. A government program to support pathogen‐free certification would likely facilitate implementation.
FP(μ‐N)2S: A Sulfur‐Pnictogen Four‐Membered Ring with 6π Electrons
Authors: Zhu Bifeng , Song Yanlin , Zhu Jun , Rauhut Guntram , Jiang Junjie , Zeng Xiaoqing
Published: June 2023

The new 6π‐electron four‐membered ring compound 3‐fluoro‐1λ2,2,4,3λ3‐thiadiazaphosphetidine, FP(μ‐N)2S, has been generated in the gas phase through high‐vacuum flash pyrolysis (HVFP) of thiophosphoryl diazide, FP(S)(N3)2, at 1000 K. Subsequent isolation of FP(μ‐N)2S in cryogenic matrices (Ar, Ne, and N2) allows its characterization with matrix‐isolation IR and UV‐vis spectroscopy by combination with 15N‐isotope labeling and computations at the CCSD(T)‐F12a/VTZ‐F12 level of theory. Upon visible‐light irradiation at 550 nm, this cyclic compound undergoes ring‐opening to the thiazyl isomer FPNSN, followed by dissociation to FP and SN2 under subsequent UV‐irradiation at 365 nm. In sharp contrast to the square planar structure for the isolobal four‐membered ring S2N2, a puckered structure with significant biradical character has been found for FP(μ‐N)2S.
The Role of the Amino Acid Molecular Characteristics on the Formation of Fluorescent Gold‐ and Silver‐Based Nanoclusters
Authors: Bélteki Rita , Kuklis Loretta , Gombár Gyöngyi , Ungor Ditta , Csapó Edit
Published: June 2023

Role of amino acids like L‐phenylalanine (Phe), L‐glutamine (Gln) and L‐arginine (Arg) is described and interpreted in terms of their potential for preparation of fluorescent molecular‐like gold and silver nanostructures. We are among the first to demonstrate the effect of syntheses conditions as well as the molecular characteristics of Phe, Gln and Arg amino acids on the structure of the formed products. Comprehensive optical characterizations (lifetime, quantum yield (QY%)) of the blue‐emitting products were also carried out. It was confirmed that for all Au‐containing samples and for Gln‐Ag system the characteristic fluorescence originates from few‐atomic metallic nanoclusters (NCs) where the reduction of metal ions was promoted by citrate in some cases. Relatively high QY% (∼18 %) was obtained for Arg‐stabilized Au NCs due to the existence of an electrostatic interaction between the electron rich, positively charged guanidium side chain of Arg and the negatively charged carboxylate group of citrate on the metallic surface. Size and structural analysis of the products were evaluated by infrared measurements and dynamic light scattering techniques.
Non‐Conjugated Bis‐(Dithienylethene)‐Naphthalenediimide as a Dynamic Anti‐Counterfeiting Agent: Driving the Wheel of Photoswitching Enactment
Authors: Kumar Bag Sayan , Karmakar Manisha , Mondal Bijan , Thakur Arunabha
Published: June 2023

Photochromic fluorescent molecules dramatically extend their fields of applications ranging from optical memories, bioimaging, photoswitches, photonic devices, anti‐counterfeiting technology and many more. Here, we have logically designed and synthesized a triazole appended bis‐(dithienylethene)‐naphthalenediimide based photo‐responsive material, 5, which demonstrated fluorescence enhancement property upon photocyclization (ΦF=0.42), with high photocyclization (44 s, ksolution=0.0355 s−1, ksolid=0.0135 s−1) and photocycloreversion (160 s, ksolution=0.0181 s−1, ksolid=0.0085 s−1) rate and decent photoreaction quantum yield (Φo→c=0.93 and Φc→o=0.11). The open isomer almost converted to the closed isomer at photo‐stationary state (PSS) with distinct color change from colorless to blue with 92.85 % conversion yield. A reversible noninvasive modulation of fluorescence through efficient photoinduced electron transfer (PET) process was observed both in solution as well as in solid state. The fluorescence modulation through PET process was further corroborated with thermodynamic calculations using the Rehm–Weller equation and quantum chemical studies (DFT). The thermally stable compound 5 exhibits high fatigue resistance property (up to 50 cycles) both in solution and solid state. Furthermore, the compound 5 was successfully applied as erasable ink and in deciphering secret codes (Quick Response/bar code) portending potential promising application in anti‐counterfeiting.
Numerical investigation on effects of fuel rod with different shapes of bow deformation on the subcooled boiling of coolant in a fuel assembly
Authors: Zhi Changshuang , Wang Xusheng , Jiang Hantao , Yang Peng , Liu Yingwen
Published: June 2023

The Eulerian two‐phase boiling model of the subcooled boiling of coolant in a 3 × 3 fuel assembly is established and compared with the experimental data to verify its accuracy. The effects of four shapes of bow deformation on subcooled boiling flow and heat transfer characteristics are obtained by comparing and analyzing the distributions of thermal–hydraulic parameters, including the axial wall superheat, liquid phase temperature, axial void fraction, various heat fluxes, heat transfer coefficient, and turbulent kinetic energy. All shapes of bow deformation will lead to the redistribution of coolant among different subchannels, and the distributions of thermal–hydraulic parameters would be greatly affected. The bow deformation of fuel rod easily causes local boiling, which results in local high temperature of liquid phase and bubble accumulation, and a decrease in the area of high liquid phase heat transfer coefficient on the surface of bowing fuel rod. Additionally, the non‐uniform distribution of turbulent kinetic energy caused by bow deformation in different axial sections not only affects the heat transfer performance of coolant, but also causes the increment in pressure drop, which has negative effects on the safe operation of the nuclear reactor. This paper can provide data and theoretical support for engineering design.
A comparative study of the catalytic nitration of toluene over bimetallic Ce‐Mn modified Hβ zeolite
Authors: Deng Renjie , Ni Wenjin , Tian Yao
Published: June 2023

Bimetallic cerium‐manganese modified Hβ zeolite sample (Ce/Mn‐Hβ) was prepared by ultrasonic assisted impregnation method and applied in nitration of toluene. The characterization results show that the active components (Ce and Mn) are successfully introduced into the framework of Hβ zeolite. The catalyst shows excellent catalytic activity and reusability for the nitration of toluene, giving high para selectivity. Under optimized conditions, it gives 68.7% selectivity to para‐nitrotoluene at 88.6% conversion over Ce/Mn‐Hβ in the presence of acetic anhydride (Ac2O). The theoretical calculations indicate that the Ce/Mn bimetallic active sites in modified Hβ zeolite can easily activate the nitrification reagent (AcONO2), and the enhancement of para selectivity is owing to the steric hindrance of catalyst. Furthermore, the reaction mechanism was proposed by the combination of experimental results and theoretical calculations.
Atomistic Simulations of Hydrated Sulfonated Polybenzophenone Block Copolymer Membranes
Authors: Sunda Anurag Prakash , Singh Soni , Yadav Sonia , Singh Raman K.
Published: June 2023

We present a classical molecular dynamics simulations study on the nanostructures of the sulfonated polybenzophenone (SPK) block copolymer membranes at 300 K and 353 K. The results of the radial distribution function (RDF) show that the interactions of the sulfonate groups of the membrane with the hydronium ions are more significant than those of water due to the strong electrostatic attraction over the hydrogen bonding. However, the effect of temperatures on the RDF profile seems insignificant. Furthermore, the spatial distribution function (SDF) portrays that the sulfonate groups of the hydrophilic components are preferential binding sites for hydronium ions against the hydrophobic counterpart of the SPK membrane. The mobility of the H3O+ ions at 300 K and 353 K is two (or three) times lower than that of Nafion/Aciplex. However, the diffusion coefficients for water molecules closely agree with Nafion/Aciplex. This study suggests that water clusters are more localized around the sulfonate groups in the SPK membranes. Thus, the molecular modeling study of SPK block copolymer membranes is warranted to design better‐performing membrane electrolytes.
Formation and Characterization of MgSe Alloys by Pulsed Laser Welding Technique
Authors: Almotiri R. A. , Qasrawi A. F.
Published: June 2023

Herein, MgSe alloys with different compositions are fabricated using laser welding techniques within a couple of minutes in an argon atmosphere. The optimum laser welding parameters, which reveal the correct compositional ratios, are determined by varying arc voltage, pulse width, welding frequency, and laser beam diameter. The structure of the MgSe alloy is monoclinic. Additionally, scanning electron microscopy studies have shown that MgSe alloys are least porous and have a layered structure. The electrical resistance of the welded alloys depends on the Mg content in the samples. Measurements from impedance spectroscopy have shown that the alloys can function as band filters, displaying cutoff frequency values of ≈16 GHz for AC signals propagating at a driving frequency of 1.0 GHz with an amplitude of 0.10 V. The properties of the MgSe alloys make them attractive for use in 5G/6G technology applications as band filters.
Outage probability analysis of multiple intelligent reflecting surface‐assisted single‐input single‐output system with switched diversity
Authors: Kumar Hindustani Rahul , Dixit Dharmendra , Sharma Sanjeev
Published: June 2023

In this paper, we have presented the outage probability analysis of multiple intelligent reflecting surface (IRS)‐assisted single‐input‐single‐output (SISO) system with switched diversity schemes. The switched diversity is simpler than the selection combining diversity technique, which can help in reducing the channel estimation overhead. There are two main types of switch diversity schemes, namely, switch and stay combining (SSC) and switch and examine combining (SEC). We consider a SISO wireless scenario in which a single transmitting antenna is sending its message to the receiving antenna with the aid of multiple IRS panels. This communication scenario will arise as a typical application of uplink scenario for future 6G wireless systems. The outage probability (OP) expressions for dual‐IRS‐panel‐aided SSC system and multiple‐IRS‐panel‐aided SEC system are analyzed, respectively, over Rician fading channels. We derive tight approximate OP expressions in closed form for a large number of IRS elements. Further, we derive a simple asymptotic OP for studying diversity order and coding gain. The OP performance with respect to each system parameter is thoroughly explored. Several numerical OP results are presented with corresponding simulated OP results to validate the accuracy of the presented analytical analysis.
Body dissatisfaction, ideals, and identity in the development of disordered eating among adolescent ballet dancers
Authors: Ohashi Yuri‐Grace B. , Wang Shirley B. , Shingleton Rebecca M. , Nock Matthew K.
Published: June 2023

Objective

Little is known about how female adolescent ballet dancers—a group at high‐risk for the development of body dissatisfaction and eating disorders—construct body ideals, and how their social identities interact with body ideals to confer risk for disordered eating. Using a novel body figure behavioral task, this study investigated (1) whether degree of body dissatisfaction corresponded to severity of disordered eating thoughts and behaviors, and (2) how ballet identity corresponded with ideal body figure size among adolescent ballet dancers.

Methods

Participants were 188 female ballet dancers ages 13‐18 years who completed self‐report measures of study constructs and the behavioral task.

Results

Linear regression models indicated that more severe body dissatisfaction was positively associated with increased disordered eating thoughts and behaviors (p < .19), except for muscle building (p = .32). We also found that identifying more strongly as a ballet dancer was correlated with having a smaller ideal body size (p = .017).

Conclusion

Findings from this study suggest desire to achieve smaller body sizes is correlated with more severe disordered eating endorsement and stronger ballet identity. Instructors and clinicians may consider assessing the extent to which individuals identify as a ballet dancer as a risk factor for disordered eating and encourage adolescent dancers to build and nurture other identities beyond ballet.

Public significance

Eating disorders are debilitating conditions that can lead to malnutrition, social isolation, and even premature death. Though disordered eating thoughts and behaviors can affect anyone, adolescents in physically demanding and body image‐driven activities including ballet dance are particularly vulnerable. Investigating how factors like body dissatisfaction and strength of identity are associated with disordered eating among high‐risk groups is crucial for developing effective prevention and intervention methods that minimize harm.
Appearance of ghost bands in gel electrophoresis depending on agarose concentration
Authors: Raab Jana , Fink Beate , Bauer Mario
Published: June 2023

Standard agarose gel electrophoresis is a widely used method to analyse diversity of nucleic acids. Certain conditions, however, may give rise to artefactual bands. We report on artefactual bands frequently occurring, especially when partially homologous nucleic acids, such as splicing variants of DNA transcripts, are analysed simultaneously. Interestingly, to some extent agarose concentration may influence the occurrence of artefactual bands.
An intelligent recommendation method for coal mine accident case via ontology knowledge service
Authors: Zhao Zhigang , Luo Xiong , Zhang Xinju , Chen Maojian
Published: June 2023

Coal mine accidents, for example, water leakage and collapse, can damage the circuit system, and they in turn can affect the stable operation of the coal mine. Therefore, it is necessary to identify the causes of coal mine accidents and reduce the number of accidents in coal mines. Government and enterprises have already accumulated numerous coal mine accident cases. To summarize the characteristics and rules of accidents, survey the deep cause of the accident, avoid the recurrence of similar accidents, and early pre‐control of risk source, there is a need to analyze the correlation in the accident characteristics. Then, with the help of ontology knowledge service model, we address this issue in this article. For guaranteeing the inference efficiency of ontology knowledge, we propose a semiautomatic construction method for coal mine accident cases to construct ontology. Here, the reliability of ontology construction and the professionalism of domain knowledge provide a feasible approach to ontology learning using structured and semi‐structured data sources. Furthermore, the weighted Word2vec and spectral clustering method are combined, an intelligent recommendation algorithm with accident ontology is accordingly presented, while presenting a local optimal distance calculation similarity strategy. This method can serve as an assistant to help users mine similar coal mine accident cases. Finally, the experimental results show that after comparing with some other popular methods, the proposed approach can achieve a satisfactory performance on the coal mine dataset with an accuracy of 99.47%, the precision of 98.92%, and the F1‐score of 99.35.
Se Atom Doping Enhances the Catalytic Activity of Co@NC for Oxygen Reduction Reaction
Authors: Guo Siwen , Lian Jie , Zhao Jinyu , Zhang Yixing , Wang Xiaomin
Published: June 2023

As the most promising nonprecious metal oxygen reduction reaction (ORR) catalyst, Co@NC catalysts have attracted much attention. Herein, to further improve the activity of Co@NC catalysts, Co and Se atoms are embedded in metal organic framework‐derived nitrogen‐doped porous carbon (NC) using a high‐temperature reduction strategy, and then Co–Se@NC catalysts are constructed. The ORR catalytic activity of the catalysts is evaluated by rotating disc electrodes, and the results show that the ORR catalytic activity of the Co–Se@NC catalysts is significantly enhanced compared to the Co@NC and Se@NC catalysts, demonstrating that the introduction of Se atoms into Co@NC catalysts can significantly improve the ORR catalytic activity. Spectral characterization and pore size analysis shows that the introduction of Se atoms has multiple effects, including providing new active sites, improving the pore structure of the catalyst, and promoting electron transfer and mass transport. This study shows that the Co–Se@NC catalysts has excellent catalytic performance for ORRs, reaching half‐wave potentials of 0.765 V in acidic electrolytes and 0.831 V in alkaline electrolytes, demonstrating that the introduction of Se atoms can effectively improve the ORR catalytic activity, thus providing a unique insight into the rational construction of ORR catalysts.
An Insight into the Wearable Technologies Based on Novel Hybrid Piezoelectric‐Triboelectric Nanogenerators
Authors: Padha Bhavya , Verma Sonali , Mahajan Prerna , Sundramoorthy Ashok K. , Arya Sandeep
Published: June 2023

Hybrid piezoelectric‐triboelectric nanogenerators (HPTNGs) are a new energy storage device that combines the benefits of both technologies. This technology can revolutionize energy storage and bring down solar and renewable costs. HPTNGs are becoming increasingly popular in the wearable technology market due to their unique characteristics. HPTNGs feature hybrid piezoelectric and triboelectric modes, allowing them to generate electricity from low voltage and sound waves. This combination gives them a higher performance than either type of generator, making them ideal for applications such as mobile banking, health monitoring, and smart home control. This article begins with a discussion on the structural configuration of hybrid HPTNGs, followed by describing their coupling effect and applications in wearable technology. Furthermore, it also focuses on the challenges, possible solutions, and prospects of this device in the wearable industry.
Application of Perforated Reference Electrodes in Small Cell Formats for Rate Tests and Electrochemical Impedance Spectroscopy
Authors: Stehle Philipp , Rutz Daniel , Bazzoun Ali Mohammad , Seidl Christoph , Bauer Ingolf , Anjass Montaha
Published: June 2023

The use of reference electrodes (REs) in lithium‐ion batteries allows enhanced electrochemical analysis of individual electrodes via potential monitoring or electrochemical impedance spectroscopy (EIS). The previous publication presents a concept for a laser‐perforated RE (PRE). Herein, this PRE is applied in ≈60 mAh graphite/NMC811 pouch cells. Despite more than 17% of the electrode surface being covered by the PRE, only negligible capacity differences are observed for charge rates up to 2C compared to cells without PRE. At higher rates up to 5C, the blocking effect is present but stable. Reproducible and plausible anode voltage curves are obtained and the beginning of Li plating is detected. Cell EIS spectra are in good agreement with comparison cells without RE. The impedance spectra of the individual electrodes recorded by the PRE are confirmative and, with one exception, artifact‐free. The results demonstrate that our PRE can be reliably applied for investigating lab‐scale electrode coatings in small pouch cell formats.
Harmonizing Seismic Performance via Risk Targeted Spectra: State of the art, dependencies, and implementation proposals
Authors: Spillatura Andrea , Vamvatsikos Dimitrios , Kohrangi Mohsen , Bazzurro Paolo
Published: June 2023

Design spectra are commonly defined for a constant value of hazard associated to an “ultimate” limit state (LS) of reference, typically 10% in 50 years. Given a specific structure, this approach results in different limit‐state exceedance risk levels even for sites characterized by the same design peak ground acceleration (PGA), mainly because of differences in hazard curve shape/slope. Instead, Risk Targeted design maps (first applied in ASCE7‐10) suggest the application of suitable spectra adjustment factors, the so‐called risk coefficients, in order to ensure a uniform collapse risk across different sites and buildings. Making use of simplified single‐degree‐of‐freedom (SDoF) structures for several configurations of vibration period and ductility, we test the effectiveness of the adjustment factors computed under different assumptions in matching a specific target risk or, at least, in harmonizing the risk of multiple buildings at different sites with respect to different LSs. Although risk matching is shown to be only theoretically possible and unachievable in practice, we claim that harmonization remains a viable target, and we offer insights for possible future adoption of Risk Targeted Spectra in the European code provisions.
Study on the influence law of well location and water injection displacement on heat extraction performance of EGS
Authors: Zhao Kai , Song Wenjie , Wang Xiaoyun , Xu Zhihui , Shi Shuyi
Published: June 2023

The enhanced geothermal system (EGS) is the key to improving the heat production efficiency of hot dry rock (HDR). Due to the existence of EGS, the reservoir produces significant heterogeneity, so the optimal design of well location and injection rate has an important influence on the heat recovery effect of an EGS. To solve this problem, a calculation model for the heat output of an EGS under multifield coupling is established in this paper, and the influence of well location and injection rate on the heat recovery effect under different scales of EGS is deeply analyzed. The results show that the production well location and injection well displacement have a great influence on the heat recovery effect under different fracture‐network scales. The larger the size of the fracture network, the larger the effective utilization area of reservoir heat recovery and the better the effect of heat recovery. The closer the production well is to the fracture network and in the direction of the fracture network, the larger the effective utilization area of reservoir heat recovery is, and the better the effect of heat recovery is. The higher the injection well displacement is, the larger the effective utilization area of reservoir heat recovery is, and the better the heat recovery effect is. The research results have important guiding significance for the optimization of the scale, well placement, and water injection displacement of the EGS in the HDR reservoir.
Correction of sideband effects of nuclear magnetic resonance carbon spectrum in coal and its application in coal structure analysis
Authors: Chang Tianyi , Zhou Xingyu , Deng Xiaopeng , Xiang Jianhua
Published: June 2023

In the nuclear magnetic resonance (NMR) test of coal, when the spinning frequency of magic‐angle spinning (MAS) is less than the frequency range of chemical shift anisotropy, serious aromatic carbon spinning sidebands will appear. Existing solutions to the sideband effect, such as changing the MAS frequency, inserting total suppression of sidebands (TOSS) pulse sequences, or simply defining the peak after chemical shift of 200 ppm as the sideband peaks generated by aromatic carbon peak, multipling the identified sideband integral by 2 and adding to the main peaks of protonated aromatic carbon and aromatic bridgehead carbon. None of these methods can reasonably correct for the sideband effect and cause errors to accurately quantifying the carbon structure parameters. Compared with 13C nuclear magnetic resonance (13C NMR) spectrum without sideband suppression (13C CP‐MAS NMR) and 13C NMR spectrum under sideband suppression conditions (13C CP‐MAS/TOSS NMR), according to the chemical shifts of the main peaks of four aromatic carbons, namely protonated aromatic carbon, aromatic bridgehead carbon, alkylated aromatic carbon and oxygen‐linked aromatic carbon, combined with the MAS frequency, the first‐ and second‐level sideband peaks generated by four types of aromatic carbons were accurately located and quantified, and they were added to the corresponding aromatic carbon main peaks in 13C CP‐MAS/TOSS NMR spectrum, thus realizing the accurate correction of sideband effect of the solid‐state 13C NMR spectrum of coal samples. The relative area of corrected aliphatic carbon, carbonyl (carboxyl) carbon, and various aromatic carbons were recalculated, and more accurate carbon structure parameters were obtained, which is significant for studying the coal structure from a microscopic perspective.
Shoreline change dynamics along the Augusta coast, eastern Sicily, South Italy
Authors: Laksono FX Anjar Tri , Borzi Laura , Distefano Salvatore , Czirok Lili , Halmai Ákos , Di Stefano Agata , Kovács János
Published: June 2023

The coastal region of Augusta, eastern Sicily, Italy, is a densely populated zone, where human pressures profoundly shaped the coastal and land dynamics. So far, understanding the interaction between natural and human processes in modelling coastal geomorphology is still quite challenging. However, coastal and environmental monitoring poses the bases for managing coastal areas properly. Therefore, the aim of this research was first to understand the medium‐term shoreline changes along Augusta Bay between 1972 and 2021, and then assess the main local coastal modifications determined by the increasing coastal armouring. To do so, the shorelines dataset was extracted from Landsat and Sentinel‐2 satellite imageries using the NDWI and mNDWI methods and then statistical parameters were computed using Digital Shoreline Analysis System (DSAS). Results show that this coastal fringe experienced significant shoreline recession over the studied time interval. Negative shoreline shifts are higher in correspondence with torrent deltas, as a result of the increasing human and natural forces insisting on the land and coastal environments. Since 1970s, Augusta Bay registered a significant increase in artificial coastal length and a coastal armouring index of Maximal level was reached today.
An overview of LTE/LTE‐A heterogeneous networks for 5G and beyond
Authors: Alam Mohammed Jaber , Hossain Md Rahat , Azad Salahuddin , Chugh Ritesh
Published: June 2023

The potential of fifth‐generation (5G) and beyond wireless connectivity is to deliver higher data rates, much lower latency, more frequent increase in channel capacity, and significant improvements in Quality of Service (QoS), compared to the current Long Term Evolution (LTE) networks. The continued growth of smart devices, the introduction of trending multimedia applications, and the dramatic increase in demand and use of wireless data communication are already causing a significant load on current mobile networks. 5G wireless networks, with enhanced user data rates, delays, capacity and QoS, are anticipated to solve many of the existing problems of mobile networks. In this study, we review the emergent wireless LTE‐A and 5G networks to provide an overview of the challenges and the solutions suggested in recent literature towards forthcoming 6G networks. We first discuss the new structural changes associated with the Radio Access Network (RAN) design, heterogeneous network and LTE or LTE‐Advanced (LTE‐A) network. To understand the challenges and research gaps in 5G and beyond networks, the paper reviews the outstanding features of the new QoS and Self‐Organization Networks (SON) related to the emerging 5G networks. Data rates, bandwidth and coverage have been given significance throughout this review because these are some major challenges towards 6G networks. Since understanding the present state of 5G usage is critical to its adoption, the paper also discusses related field tests, trials, and simulation tests. Finally, we identify existing major research problems and outline potential research areas.