bluuebunny/crossref_metadata_2025 huggingface dataset:
Transport security within the structure of national security of the Russian Federation
Authors: Zajkova Svetlana Nikolaevna
Published: January 2022

In view of the fact that transport continues to be appealing for committing unlawful acts, including terrorist attacks, the improvement of the forms and methods of managing transport sector remains a relevant topic of scientific research. The genesis of the Russian administrative-legal mechanism for ensuring transport security has its own peculiarities associated with the origin and development of state administration in the sphere of security, as well as in transport sector. Examination of the key trends and objective patterns of this process would allow modifying the existing legal regulation on the questions of security of the transport sector, taking into account the available experience, as well as historical trial and error. The article aims to determine the place of transport security within the structure of national security of the country. Comparison is conducted on the national security and transport security, as well as on the common and specific in state administration and legal regulation. The conclusion is made that the transport security is an integral part of national security of the country; therefore, the goals set by the government with regards to transport security contribute to comprehensive achievement of the goals of national security. Despite the exclusive competence of the Russian Federation in the sphere of security, there is practical legal regulation of certain issues of ensuring security, including transport, on the regional level. Special attention is given to the differences in normative legal regulation of national and transport security. The author introduces the original definition of the concept of “legislation of the Russian Federation in the sphere of transport security”, and substantiates the need for making amendments to the Federal Law “On Transport Security”. The scientific novelty is determined by articulation of the problem and consists carrying out special analysis of the legal regulation of relations in the sphere of ensuring national and transport security.
Incidence of Land use Change on Flooding and River Bank Erosion in Ngoketunjia Division, North West Region, Cameroon
Authors: Shende Kometa Sunday , Petiangma Dereck Mbeh , Kang Edwin Mua
Published: January 2022

Man in his unlimited quest for a good life through varied activities and land use changes have become an important geomorphic agent. Based on this assertion, this study was designed to examine the implications of land use changes on the incidence of flooding and river bank erosion in Ngoketunjia Division. The two-stage random sampling technique was used to administer questionnaires to 384 household heads who were predominantly farmers and occupants of flood prone areas. High resolution Landsat images of 1980 and 2016 were vectored, treated, and analysed in ArcGIS and used in conjunction with Google Earth images to delimit the bank line of a segment of the Noun River. The Pearson Correlation Coefficient (r) and the Spearman Rank Correlation coefficient (rho) were used to test the hypothesis of the study at 95% confident level. A significant positive correlation was found between the incidence of flooding and agricultural land use as well as between the incidence of flooding and settlement. The coefficients of determination (R2) of both correlation analyses revealed that agricultural land use contributed 60% of variability in the incidence of flooding while settlement shared 39.6% in the variability of its rank. An association was also noticed between some land uses and river bank processes. Mass movement and bank undercutting were found to be most dominant in cultivated areas and least in woodland areas. Geospatial analysis further revealed that between 1980 and 2016, a surface area of 2763m2 was eroded by the Upper Noun River within the approximately 4.59Km long segment delimited for the study as the gallery forest and wetlands of the area gradually gave way to farmlands and settlements. This gives an annual bank erosion rate of 76.75m2 within the segment during the 36 years’ period. The study recommends effective structural approaches to river bank stabilization, deepening and straightening of river channels while checking excessive upland degradation to reduce accelerated surface and river bank erosion.
Capsules as Miniature Factories: On‐Demand Synthesis in Prepackaged Capsules Enabled by Switching on a Catalytic Reaction
Authors: DeMella Kerry C. , Subraveti Sai Nikhil , Perry Karima J. , Karna Shashi P. , Raghavan Srinivasa R.
Published: January 2022

Biological cells convert reactants into products using enzymatic catalysis—moreover, such synthesis is done as needed. This paper presents a platform of polymer capsules that emulate the ability to synthesize products on‐demand (i.e., these “miniature factories” remain dormant at the outset, but can be switched on when needed). The structures created are multicompartment capsules (MCCs) having one or more internal compartments. Hydrophilic solutes are “hermetically sealed” in the compartments by constructing a hydrophobic wax shell around the aqueous core. While such a shell is initially impermeable, solute transport can be activated by a thermal switch, i.e., by melting the shell. The MCC factory is used to synthesize fluorescent nanoclusters (NCs) of gold and cadmium, which are useful as sensors and in bioimaging. The reaction is triggered by releasing a base from its compartment, whereupon a protein in the MCC lumen catalyzes the NC synthesis. In another example, a chemical fuel (H2O2) is released into the MCC lumen, where catalytic silver particles decompose the fuel to generate oxygen gas. The gas induces the MCC to inflate and eventually rupture—the MCC thus exhibits an emergent autonomous response that is the property of the whole, but not of any component parts.
Energy Optimization of a Mirror‐Symmetric Spherical Triboelectric Nanogenerator
Authors: Gravesen Jens , Willatzen Morten , Shao Jiajia , Wang Zhong Lin
Published: January 2022

A general theoretical analysis of a 3D generic TENG structure is presented. Using a dimensionless formulation, it is demonstrated that the optimal TENG geometry does not depend on the frequency of the moving dielectric but the external ohmic impedance for maximum power output is inversely proportional to the frequency. It is also found that the energy is proportional to the cube of the size of the TENG, the square of the triboelectric charge density σT, and the angular frequency ω of the moving dielectric. In the case of a spherical TENG where the moving dielectric is a sphere and the electrodes are spherical caps on a larger sphere three dimensionless parameters that determine the harvested energy are identified: the ratio between the radii of the two spheres = r/R, the polar angle θ of the two spherical caps formed by the electrodes, and = ZεRω, whereZis the external impedance,Ris the radius of the large sphere, ε is the permittivity of the system, and ω is the angular frequency of the moving sphere. Under the crude assumption of constant charge density on the electrodes, the optimal parameters can be easily calculated. It is found that θ = 1.1 rad, = 0.67, and = 0.18.
Self‐Healing SeO2 Additives Enable Zinc Metal Reversibility in Aqueous ZnSO4 Electrolytes
Authors: Huang Cong , Zhao Xin , Hao Yisu , Yang Yujie , Qian Yang , Chang Ge , Zhang Yan , Tang Qunli , Hu Aiping , Chen Xiaohua
Published: January 2022

The development of aqueous zinc metal batteries (AZMBs) is significantly impeded by the poor cycle stability of Zn anodes due to the uncontrolled dendrite growth and low Coulombic efficiency (CE). Herein, for the first time, SeO2 additives are introduced into ZnSO4 electrolyte to enhance the stability of the Zn anode. According to the experimental results, the protective ZnSe layer is initially in‐situ formed on the Zn surface prior to the Zn plating, which acts as a shield for inhibiting the parasitic reactions and dendrite formation. Moreover, this additive strategy yields the unique characteristic of self‐healing for recovering the cracks in the consequence of huge volume change, ensuring the durability of ZnSe layer. Consequently, Zn|Zn symmetric cell using SeO2 additive delivers an enhanced cumulative plated capacity of 2.1 Ah cm−2 under practical test conditions, which far exceeds the previously reported works. Meanwhile, the average CE of 99.6% for 250 cycles is also demonstrated in Zn|Cu half cells with the presence of the SeO2 additive. In addition, the positive effect of the SeO2 additive is further illustrated in the Zn‐MnO2 full cells with a limited Zn.
Magic of Architecting Oligo‐DNAs: 3D Structure‐Dependent Stability and Programmable Specificity to Tumor Cells
Authors: Mei Lan , Chen Bo , Fan Rangrang , Wu Min , Weng Chengxin , Tong Aiping , Zou Bingwen , Yang Hui , Nie Chunlai , Guo Gang
Published: January 2022

Constructing oligo DNAs into assemblies dramatically changes the nature of those biomacromolecules. DNA crossover is one of the classic oligo‐based nanostructures in which two or more DNA double helixes connect to each other by crossover points showing the potential to be used as structural units to develop multifunctional systems. However, research about this motif is scarce, especially in the field of biomedicine. In this study, DNase‐resistant and tumor‐distinguishing DNA nano‐assemblies based on the crossover motifs called double crossover motif (DX) and three‐helix bundle motif (3HB) are constructed. Owning to the peculiarity of secondary structure, the crossover motif shows great resistance to DNases. Such resistance is closely relevant to the 3D structure, which is confirmed by circular dichroism spectra (CD) and kinetic studies. The aptamer, AS1411, is conjugated to DNA motifs on the predetermined sites with the specific number. Depending on computer‐aided design, up to two AS1411 are conjugated to DX (DX‐x), and up to three are conjugated to 3HB (3HB‐x). Surprisingly, 3HB equipped with 3 aptamers show the best tumor discriminating ability. Confirmed by super‐resolution microscopy and live cell imaging, the manipulatable tumor specificity renders the DNA motif a potential agent for biomedical applications, including in vivo application.
Electrostatically Driven Polarization Flop and Strain‐Induced Curvature in Free‐Standing Ferroelectric Superlattices
Authors: Li Yaqi , Zatterin Edoardo , Conroy Michele , Pylypets Anastasiia , Borodavka Fedir , Björling Alexander , Groenendijk Dirk J. , Lesne Edouard , Clancy Adam J. , Hadjimichael Marios , Kepaptsoglou Demie , Ramasse Quentin M. , Caviglia Andrea D. , Hlinka Jiri , Bangert Ursel , Leake Steven J. , Zubko Pavlo
Published: January 2022

The combination of strain and electrostatic engineering in epitaxial heterostructures of ferroelectric oxides offers many possibilities for inducing new phases, complex polar topologies, and enhanced electrical properties. However, the dominant effect of substrate clamping can also limit the electromechanical response and often leaves electrostatics to play a secondary role. Releasing the mechanical constraint imposed by the substrate can not only dramatically alter the balance between elastic and electrostatic forces, enabling them to compete on par with each other, but also activates new mechanical degrees of freedom, such as the macroscopic curvature of the heterostructure. In this work, an electrostatically driven transition from a predominantly out‐of‐plane polarized to an in‐plane polarized state is observed when a PbTiO3/SrTiO3 superlattice with a SrRuO3 bottom electrode is released from its substrate. In turn, this polarization rotation modifies the lattice parameter mismatch between the superlattice and the thin SrRuO3 layer, causing the heterostructure to curl up into microtubes. Through a combination of synchrotron‐based scanning X‐ray diffraction imaging, Raman scattering, piezoresponse force microscopy, and scanning transmission electron microscopy, the crystalline structure and domain patterns of the curved superlattices are investigated, revealing a strong anisotropy in the domain structure and a complex mechanism for strain accommodation.
Exploiting the Optical Limits of Thin‐Film Solar Cells: A Review on Light Management Strategies in Cu(In,Ga)Se2
Authors: Oliveira António J. N. , Teixeira Jennifer P. , Ramos Duarte , Fernandes Paulo A. , Salomé Pedro M. P.
Published: January 2022

Light management strategies are of utmost importance to allow Cu(In,Ga)Se2(CIGS) technology market expansion, as it would enable a conversion efficiency boost as well as thinner absorber layers, increasing sustainability and reducing production costs. However, fabrication and architecture constraints hamper the direct transfer of light management architectures from other photovoltaic technologies. The demand for light management in thin and ultrathin CIGS cells is analyzed by a critical description of the optical loss mechanisms in these devices. Three main pathways to tackle the optical losses are identified: front light management architectures that assist for an omnidirectional low reflection; rear architectures that enable an enhanced optical path length; and unconventional spectral conversion strategies for full spectral harvesting. An outlook over the challenges and developments of light management architectures is performed, establishing a research roadmap for future works in light management for CIGS technology. Following the extensive review, it is expected that combining antireflection, light trapping, and conversion mechanisms, a 27% CIGS solar cell can be achieved.
Controllable Nitric Oxide‐Delivering Platforms for Biomedical Applications
Authors: Liu Shixin , Li Guowei , Ma Dong
Published: January 2022

Nitric oxide (NO) serves a multitude of functions in human physiology and pathology, and therapeutic NO‐releasing materials are vigorously developed for biomedical applications. Owing to its complex functions and its potential systemic effects, controllable NO release is desired for clinical applications. This review summarizes recent developments in the last five years in designing controllable NO‐delivering platforms for treating diseases such as cancer, bacterial infection, cardiovascular diseases, wounds, and eye diseases, with a focus on the most commonly used NO donors, includingN‐diazeniumdiolates,S‐nitrosothiols, arginine, andN‐nitrosoamines. The progress and success of NO delivery strategies are highlighted, and their limitations are also included. Moreover, the therapeutic mechanisms of NO in the diseases are summarized, along with the corresponding means of controlling NO release. Finally, the prospects and potential challenges regarding the development of NO gas therapy are described, with the hope of encouraging new research in this area.
Unraveling CoNiP‒CoP2 3D‐on‐1D Hybrid Nanoarchitecture for Long‐Lasting Electrochemical Hybrid Cells and Oxygen Evolution Reaction
Authors: Sekhar S. Chandra , Ramulu Bhimanaboina , Han Man Ho , Arbaz Shaik Junied , Nagaraju Manchi , Oh Hyung‐Suk , Yu Jae Su
Published: January 2022

Evolving cost‐effective transition metal phosphides (TMPs) using general approaches for energy storage is pivotal but challenging. Besides, the absence of noble metals and high electrocatalytic activity of TMPs allow their applicability as catalysts in oxygen evolution reaction (OER). Herein, CoNiP‒CoP2 (CNP‒CP) composite is in situ deposited on carbon fabric by a one‐step hydrothermal technique. The CNP‒CP reveals hybrid nanoarchitecture (3D‐on‐1D HNA), i.e., cashew fruit‐like nanostructures and nanocones. The CNP‒CP HNA electrode delivers higher areal capacity (82.8 μAh cm–2) than the other electrodes. Furthermore, a hybrid cell assembled with CNP‒CP HNA shows maximum energy and power densities of 31 μWh cm–2 and 10.9 mW cm–2, respectively. Exclusively, the hybrid cell demonstrates remarkable durability over 30 000 cycles. In situ/operando X‐ray absorption near‐edge structure analysis confirms the reversible changes in valency of Co and Ni elements in CNP‒CP material during real‐time electrochemical reactions.  Besides, a quasi‐solid‐state device unveils its practicability by powering electronic components. Meanwhile, the CNP‒CP HNA verifies its higher OER activity than the other catalysts by revealing lower overpotential (230 mV). Also, it exhibits relatively small Tafel slope (38 mV dec–1) and stable OER activity over 24 h. This preparation strategy may initiate the design of advanced TMP‐based materials for multifunctional applications.
Conjugated Mesopolymer Achieving 15% Efficiency Single‐Junction Organic Solar Cells
Authors: Zheng Bing , Ni Jianling , Li Shaman , Yue Yuchen , Wang Jingxia , Zhang Jianqi , Li Yongfang , Huo Lijun
Published: January 2022

The high‐performance organic solar cells (OSCs) tend to choose the polymers with high molecular weight as donors, which easily produce good crystallinity to facilitate intermolecular charge transfer. However, these polymers usually accompanied by the low solubility and synthetic difficulty, increasing batch‐to‐batch variations. The proposal of conjugated mesopolymers (molar mass (Mn) in 1–10 kDa) can overcome these problems. Herein, a new mesopolymer, MePBDFClH as donor material is designed and synthesized, and firstly applied in OSCs. As a comparison, other lower molecular weight mesopolymer of MePBDFClL and higher molecular weight polymer of PBDFCl with same structure are also prepared and investigated. Because of its appropriate phase separation and miscibility in the blend film, the MePBDFClH exhibits the highest power conversion efficiency (PCE) of 15.06% among the three materials. Meanwhile, the champion PCE is a new record for benzo[1,2‐b:4,5‐b′]difuran‐based photovoltaic materials. Importantly, comparing to the pronounced PCE decrease of polymer PBDFCl by about 12%, a slightly PCE difference for mespolymer MePBDFClL is only less than 5%, reducing the batch‐to‐batch variation. This work not only suggests that the benzo[1,2‐b:4,5‐b′]difuran unit is a promising electron‐donating core but also shows that the mesopolymers have great potentials to produce the low‐differentiated and high‐performance organic photovoltaic materials.
Long Cycle Life and High‐Rate Sodium Metal Batteries Enabled by Regulating 3D Frameworks with Artificial Solid‐State Interphases
Authors: Lai Xuejun , Xu Zhenming , Yang Xianfeng , Ke Qiongjie , Xu Qingshuai , Wang Zaisheng , Lu Yingying , Qiu Yongcai
Published: January 2022

The major challenge for sodium metal anodes is Na dendrite growth owing to the unstable and fragile solid–electrolyte interphase (SEI), leading to terrible cycle life and safety hazards. Constructing a robust SEI around a 3D porous host is considered to be a facile and efficient approach to stabilize Na metal anodes. Here, a durable 3D porous SnCl4@Na–rGO metal anode is fabricated by the in situ chemical reaction of SnCl4‐containing carbonate electrolyte with Na–rGO. Attributed to the robust SEI and the stereoscopic structure, the symmetric cells achieve a prolonged cycle life of 500 h without voltage fluctuation at 2 mA cm−2 and 2 mAh cm−2. Moreover, the Na3V2(PO4)3||SnCl4@Na–rGO full cell exhibits long‐term cycle stability (>600 cycles) and remarkable capacity retention (>92%). The novel approach provides an efficacious strategy for the practical implementation of Na metal batteries.
Flexible Strain Sensors for Wearable Hand Gesture Recognition: From Devices to Systems
Authors: Si Yuying , Chen Sujie , Li Ming , Li Siying , Pei Yisen , Guo Xiaojun
Published: January 2022

Hand gesture recognition has attracted extensive research interest, as an essential approach for human−machine interaction. The development of flexible strain sensors offers the possibility of directly measuring the finger motion behaviors for accurate and cost‐effective hand gesture recognition, by placing the sensors on the fingers or integrating them on data gloves. Herein, the operation mechanisms of various flexible strain sensor designs are introduced first. Progresses on related materials and device structures to achieve the demanded figure of merits for flexible strain sensors are then reviewed. In addition to continuous performance optimization of the flexible strain sensor devices, the development of system‐level algorithms is shown to be important for not only recognition functions but also for suppression of nonidealities of the sensor devices, which are difficult to be addressed at device and material level.
Broadband Petal‐Like Raman Laser
Authors: Miao Yujie , Zhang Lin , Dong Jun
Published: January 2022

High‐order Laguerre‐Gaussian (LG0,n) petal‐like lasers are extremely important for manipulating microparticles, creating 3D optical trapping structures, and free space optical communication. However, it is difficult to expand the wavelength of LG0,n petal‐like lasers owing to the narrow fluorescence spectrum of laser gain media. Here, a Raman laser constructed with a Yb3+:Y3Al5O12 (Yb:YAG) crystal and a yttrium vanadate (YVO4) is demonstrated for achieving a high‐order LG0,n petal‐like laser with broadband laser wavelength and high beam quality. High‐order LG0,n petal‐like lasers with n tunable from 3 to 11 are obtained. The LG0,11 petal‐like Raman laser oscillates from 1075.4 to 1088.7 nm with 44 longitudinal modes, and the bandwidth of the Raman laser is 13.3 nm. The output power of the LG0,11 petal‐like Raman laser is 126 mW with an optical efficiency of 1.5%. High‐order LG0,n petal‐like Raman lasers with tunable n provide flexible choices for potential applications in manipulating microparticles and biological molecules.
Light‐Harvesting Fluorescent Spherical Nucleic Acids Self‐Assembled from a DNA‐Grafted Conjugated Polymer for Amplified Detection of Nucleic Acids
Authors: Xiao Fan , Fang Xiaofeng , Li Hongyan , Xue Hanbing , Wei Zixiang , Zhang Wenkang , Zhu Yulin , Lin Li , Zhao Yan , Wu Changfeng , Tian Leilei
Published: January 2022

The ultralow concentration of nucleic acids in complex biological samples requires fluorescence probes with high specificity and sensitivity. Herein, a new kind of spherical nucleic acids (SNAs) is developed by using fluorescent π‐conjugated polymers (FCPs) as a light‐harvesting antenna to enhance the signal transduction of nucleic acid detection. Specifically, amphiphilic DNA‐grafted FCPs are synthesized and self‐assemble into FCP‐SNA structures. Tuning the hydrophobicity of the graft copolymer can adjust the size and light‐harvesting capability of the FCP‐SNAs. We observe that more efficient signal amplification occurs in larger FCP‐SNAs, as more chromophores are involved, and the energy transfer can go beyond the Förster radius. Accordingly, the optimized FCP‐SNA shows an antenna effect of up to 37‐fold signal amplification and the limit of detection down to 1.7 pM in microRNA detection. Consequently, the FCP‐SNA is applied to amplified in situ nucleic acid detecting and imaging at the single‐cell level.
New bio‐epoxy from sacha inchi oil by epoxidation reaction
Authors: Thuy Nguyen Thi , Tien Vu Dinh , Lan Pham Ngoc
Published: January 2022

Sacha inchi oil with large amount of double bonds (DBs) in allylic positions and double‐allylic positions was converted to an epoxidized oil by using H2O2 as the reactant. The success of this modification process has been demonstrated by Fourier transform infrared spectroscopy and 1H‐NMR spectra. The influence of the reaction agent, the components in the catalyst system such as Na2WO4, PTC (benzyldimethylstearylammonium chloride hydrate), H3PO4, and temperature on the epoxidation reaction has been studied systematically. Through the evaluation of oxirane oxygen of the epoxidized oil, the conversion of DBs, and the selectivity of the catalyst, the optimum conditions are found. They are as DB/H2O2/Na2WO4 molar ratio of 1/1.5/0.0075 and Na2WO4/PTC/H3PO4 molar ratio of 1/0.45/2. The reaction time was shortened to only 8 min when the epoxidation reaction was performed at 60°C. The epoxidized sacha inchi oil had the oxirane oxygen reaching 8.78% with a yield of 82.12% and a catalytic selectivity of 0.85.
Electrospun poly(e‐caprolactone)/propolis fiber morphology: A process optimisation study
Authors: Salimbeigi Golestan , Oliveira Renata Nunes , McGuinness Garrett Brian
Published: January 2022

This study focuses on combining the synthetic polymer poly(Ɛ‐caprolactone) with the natural antibacterial propolis, and uses response surface methodology based on a three‐level, four‐variable Box–Behnken design, to model the dependence of fiber diameter distribution on process parameters. The effect of the concentration of the antibacterial substance, the flow rate, the voltage, and the collector distance were analyzed. The linear coefficients of the antibacterial content and flow rate, and the quadratic coefficients of the voltage, distance and flow rate as well as the interaction effect between voltage and distance were found to be statistically significant. Parameters capable of forming small diameter fibers were targeted for higher surface area to material volume ratios. The parameters predicted to produce a minimum average fiber diameter of 0.506 μm were then validated in a confirmatory experiment giving a 0.505 μm average. The model maps the impact of electrospinning parameters on the fabrication and morphology of PCL/propolis scaffolds, which have potential woundcare applications.
Developmental toxicity induced by triclosan exposure in zebrafish embryos
Authors: Iannetta Annamaria , Caioni Giulia , Di Vito Viviana , Benedetti Elisabetta , Perugini Monia , Merola Carmine
Published: January 2022

Objectives

The present study aimed to investigate the acute toxicity and the developmental alterations induced by triclosan (TCS) exposure in zebrafish early‐life stages using fish embryo acute toxicity tests as a methodological approach.

Material and Methods

Zebrafish embryos were exposed to five concentrations of TCS and the four lethal alterations were daily recorded to determine the toxicological endpoints of acute toxicity. Furthermore, sublethal alterations were recorded to assess the effect of exposure concentrations on zebrafish embryo's development.

Results

The TCS toxicity was determined at 96 h of exposure as lethal concentration 10, lethal concentration 20, lethal concentration 50, lowest observed effects concentration, and no observed effects concentration, reported the following values: 168, 197.2, 267.8, 300, and 200 μg/L. Exposed larvae showed a delay in hatching rate and developed sublethal alterations including reduced blood flow, pericardial oedemata, reduced heartbeat, blood congestion, and craniofacial malformations. The number of zebrafish larvae developing cardiovascular alterations changed according to the tested concentrations and time of evaluation.

Conclusion

The data confirmed the developmental toxicity of TCS on aquatic organisms and the sublethal alterations developed by zebrafish larvae, indicated its cardiotoxicity and neurotoxicity. Moreover, the developmental toxicity was strongly influenced by the concentration tested and the number of survived zebrafish developing this alteration varying according to the time of exposure.
Tuning of Oxygen Reduction Pathways through Structural Variation in Transition Metal‐Doped Ba2In2O5
Authors: Thundiyil Shibin , Pandikassala Ajmal , Kurungot Sreekumar , Devi R. Nandini
Published: January 2022

Oxygen reduction reaction (ORR) can take place either through a two‐electron pathway to form H2O2 or through a four‐electron pathway to form H2O. Both the reactions are important in the respective fields, viz., H2O2 production as well as fuel cell technology, and rational design of catalysts is mandatory to acquire high energy efficiency in both cases. Here, we report the structure‐electrochemical property correlation of a series of perovskite related brownmillerite compounds, Ba2In0.75M0.25O5 (M=Mn/Fe/Co/Ni/Cu), synthesized by solid‐state method. On transition metal doping, octahedral distortions were observed, and the highly disordered material tends to follow the 4e transfer mechanism. More symmetrical structures followed the 2e pathway to form H2O2 as the product with high peroxide selectivity. The distortion in the octahedral arrangement can be a descriptor to finetune the selectivity of the catalysts towards the 2e and 4e pathways of ORR.
Prebiotic properties of jiaogulan in the context of gut microbiome
Authors: Huang Gouxin , Yasir Muhammad , Zheng Yilin , Khan Imran
Published: January 2022

Jiaogulan (Gynostemma pentaphyllum) is a traditional Chinese medicinal herb that has been widely used in food and supplemental products. In the last 20 years, extensive research has been conducted to investigate the medicinal prospects of jiaogulan, and in this regard, more than 200 compounds have been isolated with various medicinal properties such as anticancer, anti‐obesity, anti‐inflammation, and antioxidation. In respect of potential benefits, jiaogulan market is likely growing, and various food items comprised of jiaogulan (beverage, sport drinks, cola, beer, tea, bread, and noodles) have been commercialized in the United States of America, China, and other Asian countries. More recently, there has been growing interest in the prebiotic potential of jiaogulan, especially at the interface of the gut microbiota. This review focuses on the prebiotic and therapeutic aspects of saponins and polysaccharides of jiaogulan tea by summarizing the literature on cancer, obesity, antioxidant activity, and immune‐modulatory properties.
Numerical investigation of a convective hybrid nanofluids around a rotating sheet
Authors: Prathiba Alfunsa , Akavaram Venkata Lakshmi
Published: January 2022

Hybrid nanofluids are formulated with various kinds of base fluids. They are designed to provide good heat transfer performance. They can achieve this by dispersing various kinds of nanoparticles in the base materials. This new technology of formulating hybrid nanofluids has a wide range of applications in various industries such as solar energy, medical equipment, and aerospace. Keeping these applications in view, this study provides an insight into the effects of convective heat transport on a Hybrid nanofluid, across a rotating sheet with a variable heat source. In this investigation, the governing boundary layer partial differential equations were modified into the ordinary differential equations, by using the proper similarity transformations. Later, they were solved numerically, with the support of the Lobatto IIIA technique in MATLAB. The influence of the Richardson number on flow parameters was studied, and it was discovered that increasing Ri increases the velocity while decreasing temperature and concentration profiles. The impact of various other flow parameters on the flow fields and also on the behavior of Nusselt number, coefficient skin friction, and Sherwood number were studied and represented graphically. The outcomes were found to be in excellent accord when compared with quoted studies.
Mixed convection and entropy production of a hybrid nanofluid in a porous cylindrical enclosure with rotating top wall
Authors: Bellout Saliha , Bessaїh Rachid
Published: January 2022

A numerical study is carried out to investigate heat transfer and entropy production of a hybrid nanofluid in a porous cylindrical enclosure with a rotating top wall. The bottom wall of the cylinder is taken as hot, the sidewall is adiabatic, except the top wall is considered cold and rotates at an angular velocity (ΩR). The effects of a hybrid nanofluid flow on heat transfer and entropy generation are examined for an aspect ratio (H/R = 1). A FORTRAN program was elaborated for solving the governing equations based on the finite volume method. Good agreement was found when comparing results from this study against published data. Our results are presented for different Reynolds number values (100 ≤ Re ≤ 1500), nanoparticle fraction NP (0 ≤ ϕ ≤ 0.08), Darcy number (10−4 ≤ Da ≤ 10−1) and porosity of the porous medium (0.2 ≤ ε ≤ 0.99) for Ri = 0.5, 1,5 and 8, where (Ri = Gr/Re2). They reveal that the heat transfer increases with Re, ϕ, Da, Ri, and decreasing ε. The simulation data were used to propose four different correlations for and Stot as Re, Da, Ri, ϕ, and ε.
Cervical ripening with multiple medical or combined induction methods: Risks of subsequent preterm birth in nulliparous women
Authors: Farago Naama , Ginsberg Yuval , Bachar Gal , Beloosesky Ron , Zipori Yaniv , Vitner Dana , Weiner Zeev , Ganem Nadir , Khatib Nizar
Published: January 2022

Objective

To determine the impact of combined medical and medical/mechanical methods for cervical ripening on the risk of preterm birth in subsequent pregnancy, in nulliparous women.

Methods

A retrospective cohort study of nulliparous women with term singleton gestations induced by single or combined methods at one center who had their subsequent second birth in the same center. Study groups were compared with a control group of nulliparous women not induced. The primary outcome was risk of preterm labor in the second consecutive birth. Secondary outcomes included neonatal and maternal complications.

Results

Cohort included 1277 nulliparous women who underwent cervical ripening by single or combined methods. The study group consisted of 942 women induced by one dose of prostaglandin E2, 248 women induced by combined methods, and 87 women induced by a mechanical method. The control group consisted of 3903 women. Demographic data of the groups were comparable. Rates of spontaneous preterm birth and early spontaneous preterm birth in the subsequent births did not differ between the groups.

Conclusion

Cervical ripening with combined methods or multiple medical methods did not increase the rate of subsequent spontaneous preterm births in nulliparous women or change the neonatal and maternal complications rate.
Estrogen-Responsive Gene MAST4 Regulates Myeloma Bone Disease
Authors: Cui Yushan , Wang Fangfang , Zhang Danfeng , Huang Jingcao , Yang Yan , Xu Juan , Gao Yuhan , Ding Hong , Qu Ying , Zhang Wenyan , Liu Weiping , Pan Ling , Zhang Li , Liu Zhigang , Niu Ting , Liu Ting , Zheng Yuhuan
Published: January 2022

Our previous data showed that young female multiple myeloma (MM) patients had a low frequency of osteolytic lesions. Based on this clinical observation, we found that estrogen cell signaling played a regulatory role in MM bone disease (MMBD), and the estrogen-responsive gene microtubule-associated serine/threonine kinase family member 4 (MAST4) was a critical factor. The presence of estrogen in cell cultures promoted MAST4 expression in MM cells, while knocking down estrogen receptor 1 (ESR1) inhibited MAST4 expression. Chromatin immunoprecipitation assay suggested a binding site of ESR1 on the MAST4 promoter. Bisphosphonates, such as zoledronic acid (ZOL), which was widely used in MMBD control, could stimulate MAST4 expression in MM cells by promoting ESR1 expression. MAST4 interacted with phosphatase and tensin homolog (PTEN), therefore regulating the PI3K-Akt-mTOR pathway and the expression of downstream cytokines, such as CCL2/3/4. MAST4 knockdown (MAST4-KD) or ESR1 knockdown (ESR1-KD) MM cells had repressed PTEN activity, elevated PI3K-Akt-mTOR activity, and increased CCL2/3/4 expressions. Coculture of MAST4-KD or ESR1-KD MM cells with pre-osteoclasts (pre-OCs) stimulated OC formation in vitro, whereas neutralizing antibodies of CCL2/3/4 attenuated such stimulation. In mouse models, mice inoculated with MAST4-KD or ESR1-KD MM cells had severer MMBD than control knockdown (CTR-KD). The correlations between MAST4 and ESR1 expressions in MMBD, as well as related cell signaling pathways, were confirmed in analyses using gene expression profiles (GEPs) of patients' MM cells. The negative correlation of MAST4 expression and occurrence of MMBD was further validated by patients' immunohistochemical tissue array. Overall, our data suggested that estrogen cell signaling negatively regulated MMBD through MAST4. © 2022 American Society for Bone and Mineral Research (ASBMR).
Distributions of Microdamage Are Altered Between Trabecular Rods and Plates in Cancellous Bone From Men With Type 2 Diabetes Mellitus
Authors: Sacher Sara E. , Hunt Heather B. , Lekkala Sashank , Lopez Kelsie A. , Potts Jesse , Heilbronner Alison K. , Stein Emily M. , Hernandez Christopher J. , Donnelly Eve
Published: January 2022

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of fragility fracture despite exhibiting normal to high bone mineral density (BMD). Conditions arising from T2DM, such as reduced bone turnover and alterations in microarchitecture, may contribute to skeletal fragility by influencing bone morphology and microdamage accumulation. The objectives of this study were (i) to characterize the effect of T2DM on microdamage quantity and morphology in cancellous bone, and (ii) relate the accumulation of microdamage to the cancellous microarchitecture. Cancellous specimens from the femoral neck were collected during total hip arthroplasty (T2DM: n = 22, age = 65 ± 9 years, glycated hemoglobin [HbA1c] = 7.00% ± 0.98%; non-diabetic [non-DM]: n = 25, age = 61 ± 8 years, HbA1c = 5.50% ± 0.4%), compressed to 3% strain, stained with lead uranyl acetate to isolate microdamage, and scanned with micro–computed tomography (μCT). Individual trabeculae segmentation was used to isolate rod-like and plate-like trabeculae and their orientations with respect to the loading axis. The T2DM group trended toward a greater BV/TV (+27%, p = 0.07) and had a more plate-like trabecular architecture (+8% BVplates, p = 0.046) versus non-DM specimens. Rods were more damaged relative to their volume compared to plates in the non-DM group (DVrods/BVrods versus DVplates/BVplates: +49%, p < 0.0001), but this difference was absent in T2DM specimens. Longitudinal rods were more damaged in the non-DM group (DVlongitudinal rods/BVlongitudinal rods: +73% non-DM versus T2DM, p = 0.027). Total damage accumulation (DV/BV) and morphology (DS/DV) did not differ in T2DM versus non-DM specimens. These results provide evidence that cancellous microarchitecture does not explain fracture risk in T2DM, pointing to alterations in material matrix properties. In particular, cancellous bone from men with T2DM may have an attenuated ability to mitigate microdamage accumulation through sacrificial rods. © 2022 American Society for Bone and Mineral Research (ASBMR).

Abstract

Reconstructions of representative T2DM cancellous specimen with highlighted plate microdamage (green) and rod microdamage (red). Rods were more damaged relative to their volume vs. plates in non-DM specimens but this difference was absent in T2DM specimens.
Seroepidemiology of SARS‐CoV‐2 in pediatric population during a 16‐month period prior to vaccination
Authors: Filippatos Filippos , Tatsi Elizabeth‐Barbara , Dellis Charilaos , Efthymiou Vasiliki , Margeli Alexandra , Papassotiriou Ioannis , Syriopoulou Vasiliki , Michos Athanasios
Published: January 2022

Limited prospective serosurveillance data in children regarding severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection have been reported. We prospectively investigated SARS‐CoV‐2 seropositivity in children during a 16‐month period of the coronavirus disease 2019 (COVID‐19) pandemic, including the four waves of the pandemic, before SARS‐CoV‐2 adolescents' vaccination. Serum samples from children admitted to the major tertiary Greek pediatric hospital for any cause, except for COVID‐19 infection, were randomly collected from 05/2020 to 08/2021. The study period was divided into four 4‐month periods representing relevant epidemic waves. Total SARS‐CoV‐2 antibodies for nucleocapsid protein were determined using the Elecsys® Anti‐SARS‐CoV‐2 reagent. A total of 3099 children (0–16 years) were included in the study. A total of 344 (11.1%) seropositive children were detected (males: 205 [59.5%]; median age [interquartile range [IQR]]: 3 years [0.6–10]). Seropositivity rates (%) increased during the four 4‐month periods: 1.4%, 8.6%, 17.2%, and 17.6%, respectively. A correlation of seropositivity rates in children with new diagnosed SARS‐CoV‐2 cases in the community was detected. No significant differences were detected between males and females. Seropositivity was significantly higher in hospitalized than in nonhospitalized children and in non‐Greek compared to Greek children (p < 0.001). The lowest seropositivity rate before school opening (9/2021) was detected in the age groups 6–12 years (14.4%) and 12–16 years (16.1%). However, compared with the other age groups, the lowest median antibody titers were observed in children 0–1 year (median [IQR]: 13.9 cut‐off index: [4.5–53.9] [p < 0.001]). Although the seropositivity of children was related to the community epidemic waves, the exposure was limited. Low seropositivity rates in school‐age children support the need for SARS‐CoV‐2 immunization.
Soil nematode communities and functions: Ecological package restoration responses in damaged desert steppe open‐pit mining ecosystems
Authors: Gao Zhiwei , Liu Ziying , Wu Zhaohui , Huang Jing , Zhang Li , Zhang Guogang , Jia Meiqing , Han Guodong
Published: January 2022

Ecological restoration of open‐pit mine wasteland is critical to the sustainable development of the mining industry. Using high‐throughput sequencing, we analyzed soil properties and nematode community structure and function to evaluate the impact of ecological package restoration on the quality of underground ecosystem reclamation in desert steppe open‐pit mine wasteland. After 7 years of ecological package restoration at an open‐pit quarry, two management methods (annual removal of dominant plant genera and annual reseeding of missing plants) achieved the expected outcomes of the restoration project (return to the conditions of the pre‐disturbed ecosystem). Based on LEfSe multi‐level discriminant analysis and shared genera analysis, we suggest that Oxydirus, Dorylaimus, Trichotylenchus, Plectus, Scutylenchus, Paratylenchus, Tylencholaimus, and Cephalobus may be the key soil nematode genera in the damaged open‐pit quarry ecosystem. We also evaluated the soil health status of different ecological package restoration time periods (2 and 5 years) at an abandoned desert steppe open‐pit iron mine by analysis of the soil properties and nematode communities. We suggest that ecological package restoration for 5 years achieved the expected restoration outcomes in the open‐pit iron mine wasteland. Based on LEfSe analysis and shared genera analysis, we suggest that Acrobeles, Microdorylaimus, Cehalobus, Tripylina, and Ecumenicus may be the key soil nematode genera in the damaged open‐pit iron mine ecosystem. Our findings provide a reference for evaluating the reclamation effect of ecological package restoration in open‐pit mine areas.
The corrosion of carbon steel under delaminating repair coatings after long‐term marine splash zone exposure
Authors: Momber Andreas W. , Krenz Andreas , Buchbach Sascha
Published: January 2022

Organic repair coatings are applied to repair areas of previously coated low‐carbon steel samples, and the samples are exposed to the splash zone in an offshore environment (Helgoland, North Sea) for 57 months. The volume loss of the steel underneath the delaminated coating is estimated with a three‐dimensional optical stripe line projection. The samples show a small variation in the degree of delamination (22%) only. The steel volume loss values, in contrast, range between 164 × 109 and 320 × 109 µm³, which is a variation of 196%. The degree of delamination of the scribed coatings does not mirror the corrosion of the steel underneath the delaminated sections. The coating with the widest degree of delamination exhibits the lowest steel volume loss due to corrosion. A good scribe performance of a coating is, therefore, no guarantee for a low corrosion loss nor for a low local corrosion depth in the steels to be protected.
On‐Chip Direct Laser Writing of PAN‐Based Carbon Supercapacitor Electrodes
Authors: Hoffmann Andreas , Jiménez‐Calvo Pablo , Bansmann Joachim , Strauss Volker , Kuehne Alexander J. C.
Published: January 2022

The carbonization of polyacrylonitrile (PAN) by direct laser writing to produce microsupercapacitors directly on‐chip is reported. The process is demonstrated by producing interdigitated carbon finger electrodes directly on a printed circuit board (PCB), which is then employed to characterize the supercapacitor electrodes. By varying the laser power, the process can be tuned from carbonization to material ablation. This allows to not only convert pristine PAN films into carbon electrodes, but also to pattern and cut away non‐carbonized material to produce completely freestanding carbon electrodes. While the carbon electrodes adhere well to the printed circuit board, non‐carbonized PAN is peeled off the substrate. Specific capacities as high as 260 µF cm⁻2 are achieved in a supercapacitor with 16 fingers.
Functionalizing mesoporous silica with a nano metal–organic phosphonate towards mechanical‐robust, thermal‐resistant, and fire‐safety epoxy resin
Authors: Wang Wenduo , Wang Zhengzhou
Published: January 2022

Epoxy resin (EP) has featured many industrial and practical applications, but was plagued by its inherent flammability. Herein, a hybrid flame retardant (mSiO2@TETP) was fabricated by in‐situ immobilizing tin ethylenediamine tetramethylene phosphonate (TETP) on the mesoporous silica (mSiO2) surface, and was used to prepare mechanical‐robust, flame‐retardant, and thermal‐resistant EP composites. It is found that the introduction of only 1.0 wt% mSiO2@TETP into EP leads to a 20.5%, 19.7%, and 12.8% incremental tensile modulus, tensile strength, and impact strength, respectively. The EP composite with 5.0 wt% mSiO2@TETP (EP/mSiO2@TETP‐5) succeeds to the UL‐94 V‐0 grade, with a limiting oxygen index value of 29.0%. And the peak heat release rate, total heat release, peak smoke production rate, total smoke release, and peak CO production rate of EP/mSiO2@TETP‐5 decrease by 54.0%, 52.1%, 53.9%, 51.1%, and 55.7%, respectively in contrast with the values of pure EP. Moreover, the introduction of mSiO2@TETP results in an improvement in both the charring capacity and the initial thermal resistance (an increment in the glass transition temperature) of EP.
Academic self‐efficacy and academic performance among high school students: A moderated mediation model of academic buoyancy and social support
Authors: Lei Weina , Wang Xuewei , Dai David Yun , Guo Xipei , Xiang Shuoqi , Hu Weiping
Published: January 2022

Previous studies have illustrated a robust relationship between academic self‐efficacy and academic performance. However, the underlying psychological mechanism of this relationship is still unclear. This study employed a moderated mediation model to examine whether academic buoyancy (ability to deal with academic challenges and setbacks in school daily life) mediated the relationship between academic self‐efficacy and academic performance and whether social support moderated the mediation process. A total of 860 (M = 16.39, SD = 0.73) high school students in China completed questionnaires on academic self‐efficacy, academic buoyancy, and social support. Academic performance was measured by standardized tests. The results indicated that academic buoyancy partially mediated the association between academic self‐efficacy and academic performance. Social support moderated the first half of the path of the mediation model. The findings of the present study provide educational guidelines and suggestions for improving academic performance among high school students.