bluuebunny/crossref_metadata_2025 huggingface dataset:
Discurso y trabajo de la economía colaborativa. El caso de Blablacar
Authors: Riesgo Gómez Víctor
Published: April 2022

La importancia creciente del campo de la economía colaborativa está asociada al crecimiento de las plataformas tecnológicas que desarrollan su modelo de negocio en este sector. Estas compañías ocupan una posición central en este espacio y acumulan cada vez más poder para definir el espacio de posibilidades de las prácticas que caben en la economía colaborativa. De todas ellas, la compañía europea Blablacar parece ocupar por derecho propio un lugar de privilegio en este sector. Su posición se ve reforzada por un discurso impregnado de la retórica colaborativa. Este factor, el discurso, es una seña de identidad de estas compañías. Su objetivo es tratar de encuadrar el modelo de negocio en un espacio diferente al del capitalismo más convencional. Sin embargo, nuestro análisis de este discurso nos permite identificar unos presupuestos filosóficos e ideológicos muy alejados de los valores altruistas. Por el contrario, induce a realizar una serie de tareas de vigilancia de los usuarios entre sí. En segundo término, el análisis por medio de etnografía virtual de sus sistemas de reputación nos permite señalar la importancia del trabajo oculto sobre el que se sostiene el sector. Se analizan las distintas dimensiones de este trabajo oculto. Finalmente, se sugiere la necesidad de, si se quiere conservar el rigor, dejar de emplear cualquier referencia al término colaborativo en los análisis de este plataforma o de otras basadas en condiciones similares.
The growing importance of the field of the collaborative economy is associated with the growth of the technological platforms that develop their business model in this sector. These companies occupy a central position in this space and accumulate more and more power to define the space of possibilities of the practices that fit in the collaborative economy. Of all of them, the European company Blablacar seems to occupy a privileged place in this sector. His position is reinforced by a discourse steeped in collaborative rhetoric. This factor, the speech, is a hallmark of these companies. Its objective is to try to frame the business model in a different space from that of more conventional capitalism. However, our analysis of this discourse allows us to identify philosophical and ideological assumptions far removed from altruistic values. On the contrary, it induces a series of surveillance tasks between users to be carried out. Second, the analysis by means of virtual ethnography of its reputation systems allows us to point out the importance of the hidden work on which the sector is sustained. The different dimensions of this hidden work are analyzed. Finally, it is suggested the need, if rigor is to be preserved, to stop using any reference to the term collaborative in the analyzes of this platform or of others based on similar conditions.
La obra nueva de la catedral de Sevilla y la familia Enríquez: un Libro de Fábrica de 1453 en el Archivo Histórico Casa de Alba
Authors: Belmonte Fernández Diego
Published: April 2022

El objetivo del presente trabajo es estudiar y poner en valor un librete de cuentas del año 1453 perteneciente a la mayordomía de Fábrica de la catedral de Sevilla hallado en el Archivo Histórico de la Casa de Alba y hasta ahora inédito. El análisis de su materialidad y sus aspectos formales nos permitirán encuadrarlo en el engranaje económico administrativo de la institución capitular en un momento crucial de su historia, el de la construcción del actual templo gótico en sustitución de la vieja mezquita aljama cristianizada durante el siglo XV. Con los datos recabados además hemos podido identificar con precisión al mayordomo que lo elaboró e integrarlo en uno de los linajes medievales más poderosos de Castilla, el de los Enríquez, almirantes, así como trazar el camino que llevó a este libro hasta su actual ubicación archivística. Se presenta, por último, una edición íntegra de su texto.
INFLUENCE OF SLICER SOFTWARE USED WITH 3D PRINTING FILAMENT EXTRUSION TECHNOLOGY ON PROPERTIES OF PRINTED PARTS WITH SHORT FIBER REINFORCED THERMOPLASTIC COMPOSITE
Authors: GOMEZ ALONSO JOSE LUIS , ALLUE SALVADOR ALEXANDRA , DE MARCO RODRIGUEZ ISABEL , RETOLAZA GAVIÑA JONE , DIEZ BARCENILLA GORKA
Published: April 2022

3D printing with filament extrusion technology is a process in which the thermoplastic molten material is sequentially accumulated layer by layer on a construction platform. 3D printers use a slicer software that converts 3D digital models into printing instructions. The software calculates the trajectory of the extruder within the printer, from three-dimensional mesh-based models. The input of the lamination software is a “.stl” file and the output is a “.gcode” file. For each layer, the lamination program generates the path that the printer extruder will travel, this could determine if a part is correctly made or not.
The objective of this study has been to analyze, with a view to industry implementation of the 3D printing, if the slicer software used in the extrusion 3D printing of short glass fiber reinforced thermoplastic, influences the final results that are obtained in the printed parts. It has been worked with four 3D printing slicer software, and it has been analyzed if there are significantly differences in mechanical and dimensional properties in the printed parts. For which, in the printing tests, always the same filament printer, printing material, part design, ".stl" file, and values for the percentage and type of filling, height layer and skin thickness have been used. The additive material used was a 2.85 mm diameter filament of 30% short glass fiber reinforced polyamide 6.

It has been concluded that the slicer software, considering the evaluated ones, influences the results of the percentage of deformation at maximum tension, of the printed parts. The influence on the values of the resistance and the tensile modulus is not significant.

Keywords: Filament fused fabrication (FFF), fused deposition modeling (FDM), short fibre composites, slicer software, printing parameters, tensile strength.
MOVING OBJECTS DETECTION, CLASSIFICATION AND TRACKING OF VIDEO STREAMING BY IMPROVED FEATURE EXTRACTION APPROACH USING K-SVM
Authors: RAJARAM DHIVYA , SIVAKUMAR KOGILAVANI
Published: April 2022

The computer vision plays a vital role in variety of applications such as traffic surveillance, robotics, human interaction devices, etc. The video surveillance system has designed to detect, track and classify the moving objects. The moving object detection, classification and tracking of video streaming has various challenges, which utilizes various novel approaches. The existing work uses spatiotemporal feature analysis using sample consistency algorithm for moving object detection and classification. It is not performed well with the complex scene on the video. The binary masking representation of moving object is the challenging task for the researchers. These video streams are partitioned based on the frames, shots, and scenes; here the proposed research work utilizes kernel-Support Vector Machine learning technique for moving object detection and tracking. In this approach, the MIO-TCD DATASET is used for moving object detection. Here the feature extraction is the major part of foreground and background analysis in the video streaming, which utilizes the vehicle features based video data. The SURF (Speeded-Up Robust Feature) feature is used to recognize/register the object and it also used for classification of moving objects. Here the optical flow method is to quantify the relative motion of object in the video streams. Based on the differences on the partitioned frames, the optical flow features hold the object for measuring the pixel of the moving objects. The feature extraction process is improved by combining feature class with intensity level of optical flow result, which makes the gradient analysis of first order derivative function. The proposed method achieves the result of recall, precision, and f-measures than the existing work. The proposed method is done with the help of MATLAB 2018a.

Keywords: Computer Vision and Pattern Recognition; Kernel-SVM; SURF features; Optical Flow; Texture feature; Moving object detection, tracking and classification;
IDENTIFICATION OF PARAMETERS FOR CHARACTERIZATION AT HIGH-TEMPERATURE OF 38MnVS6 STEEL USED IN HOT FORGING PROCESSES
Authors: GOMEZ MARQUEZ DIEGO ARMANDO , LEDESMA OROZCO ELIAS RIGOBERTO , HINO RYUTARO , AGUILERA  GOMEZ EDUARDO , HAMASAKI HIROSHI
Published: April 2022

Finite element reliability is highly sensitive to the input data quality and constitutive equations used. In this article, two constitutive equations for modeling the plastic flow of metals are used. Two equations commonly employed in metal forming finite element analysis were selected, e.g., the Hensel-Spittel and Johnson-Cook. Compression tests were conducted at various temperatures and strain rates to obtain the plastic flow stress curves. These experimental results were used as a target to fit the constitutive equation parameters. The parameter identification procedure was conducted by solving the so-called inverse problem. An objective function gives a value (error) that indicates how well a parameter set makes the equation fits the experimental results. This error value is minimized by applying optimization techniques; in this case, by using a Genetic Algorithm followed by a gradient-based strategy. Two objective functions are used; the first is based on the well-established least square approach, and the second is proposed. The proposed objective function shows a faster performance than the least square. In addition, the proposed objective function also gives the best fit for the Hensel-Spittel equation. The Johnson-Cook equation is fitted using only the proposed function. The Hensel-Spittel equation shows several local minimums, whereas the Johnson-Cook shows a global one.

Keywords: Hot forging, Parameter identification, constitutive equations, finite element analysis.
A review of welfare indicators for sea turtles undergoing rehabilitation, with emphasis on environmental enrichment
Authors: Diggins R , Burrie R , Ariel E , Ridley J , Olsen J , Schultz S , Pettett-Willmett A , Hemming G , Lloyd J
Published: April 2022

For animals undergoing rehabilitation it is vital to monitor welfare in a way that is feasible, practical, and limits stress to the animal. The industry gold standard is to assess welfare under the Five Domains model, including nutrition, environment, physical health, and behaviour as the first four physical domains and mental domain as the fifth. Feasibility and effectiveness of these domains for assessing welfare of sea turtles undergoing rehabilitation were reviewed and it was determined that the mental state can be best assessed through behavioural changes. A scoping review of the literature was conducted using Scopus and Web of Science to investigate use of environmental enrichment devices (EEDs) as a measure of welfare in sea turtles. Behavioural assessments using EEDs were found to be well-documented; however, most EED studies pertained largely to livestock or zoo animals. Furthermore, studies rarely concentrated on reptiles, and specifically sea turtles. Results also showed that certain welfare assessment methods may be less appropriate for short-term captivity experienced during rehabilitation. Additionally, the hospital environment limits the ability to address some of the domains (ie biosecurity, feasibility, safety of turtle, etc, might be compromised). This review shows that only three of the nine environmental enrichment strategies described in the literature suit the specific requirements of sea turtles in rehabilitation: feeding, tactile, and structural. It is documented that turtles display behaviours that would benefit from EEDs and, therefore, more specific studies are needed to ensure the best welfare outcomes for sea turtles undergoing rehabilitation.
Assisted Living
Authors: Small Helen
Published: April 2022

Documentary film and television have played, and continue to play, a major role in shaping public conversations about standards of care today for those in later life who are no longer able to live independently. The starkest example in the UK in recent years was the BBC Panorama documentary Undercover Care: The Abuse Exposed, aired in May 2011, which contributed heavily to official denunciation of the Care Quality Commission as “unfit for purpose.” This paper looks in detail at a less gruelling example of the genre. Neither an exposé of malpractice nor a fly-on-wall documentary, Room 335 (HBO Documentary Films, 2006) is closer to participant anthropology—though it is not quite that either. The paper, delivered as a plenary lecture to the British Society of Gerontology Annual Conference, September 2013, makes a case for valuing the quality of the film’s improvisational, non-“findings driven” engagement with its subjects, and the light it sheds on the nature and sig- nificance of friendship in old age. The film can be downloaded from Apple iTunes at https://itunes.apple.com/ca/artist/andrew-jenks/id563448630.
“I’m an old fucking woman as of today”
Authors: Henderson Julia
Published: April 2022

Sally Clark has been an influential figure in Canadian theatre and scholarship since the 1980s. While some critics have traced feminist impulses in her work, none have yet considered how some of her plays unsettle dominant paradigms of aging and old age. This article analyses Clark’s dramaturgy in two plays that offer compelling portraits of women aging into and experiencing old age: Moo and Ten Ways to Abuse an Old Woman. While at times Clark reinscribes ageist narratives, she also offers resistant and rebellious alterna- tives to dominant age ideology, particularly in her disruption of the decline narrative. Clark’s use of achronicity, disruption of rising conflict, intratextual polyvocality, ambiguous endings, and humor results in constructions of female aging and old age that highlight performativity, challenge disease (senility) as an objective category, and disrupt the simplistic association between aging and loss. Through considering how a play’s dramatic structure works to expose or conceal, subvert or reinforce dominant age ideology, this analysis reveals the complex processes through which age narratives are imprinted on our cultural consciousness in the ways that stories are told—not just through their themes, but also through their structure, which influences how we understand time, the finitude of events, and the prominence of voices.
Review of 'Discourses of Ageing in Fiction and Feminism: The Invisible Woman' by Jeanette King
Authors: Pellegrino Olivia
Published: April 2022

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Enhancing the GDEMs of Egypt Using a Surface Subtraction Approach
Authors: El-Ashmawy Nagwa , Al-Krargy Essam
Published: April 2022

This paper proposes an enhancement approach to improve the accuracy of global Digital Elevation Models (GDEMs) in Egypt. The proposed approach is an empirical one that depends on subtracting the heights error from the original DEM. The research includes the evaluation and enhancement of SRTM-1 (SRTM v4.1), ASTER GDEM v2, and AW3D30 v2 GDEMs, in Egypt, using 980 well distributed GPS/levelling points, that cover the entire country. The GPS/levelling points are divided into 500 control and 390 check points. The results show that the root mean square error (RMSE) in the SRTM, ASTER and AW3D30 are 3.99 m, 8.81 m, and 2.98 m respectively.For enhancing purposes, two different approaches are used: a linear regression analysis approach, and the proposed empirical surface subtraction approach. The results of the linear regression analysis approach show that the accuracies are improved by 3%, 16%, and 3% for SRTM, ASTER and AW3D30 respectively. However, the accuracies are improved by 5%, 23%, and 16% for SRTM, ASTER and AW3D30 respectively when the proposed approach is followed. After using the proposed approach, the obtained accuracy of the enhanced DEM reached 2.5 m.
New aspects for the oscillation of first-order difference equations with deviating arguments
Authors: Attia Emad R. , El-Matary Bassant M.
Published: April 2022

We study the oscillation of first-order linear difference equations with non-monotone deviating arguments. Iterative oscillation criteria are obtained which essentially improve, extend, and simplify some known conditions. These results will be applied to some numerical examples.
Assessment of the Effect of Electromagnetic Field on Bacterial Load and Physicochemical Properties of A Selected Food and Dairy Industry Effluent in Akure
Authors: A. M. Ilemobayo, , O. D. Teniola,
Published: April 2022

Management of industrial effluents is one of the major challenges affecting developing nations of the world. Many of these industries release their effluents indiscriminately into the environment without proper treatment, which has caused a great health hazards to the environment and living population of this nation. The aim of this study was to determine the effect of electromagnetic field on microbial load of industrial effluents from food and dairy industry at Akure, Ondo state, Nigeria. Bacteria were isolated and identified using biochemical and molecular methods. Microbiological analysis and physicochemical characterization of the industrial effluent were carried out to determine the effect of electromagnetic field on microbial load and physicochemical parameters of the industrial effluents. Eleven bacteria were isolated from the effluents, the morphological, microscopic and biochemical characteristics of the eleven isolated bacteria suggests  the isolates to be  Bacillus cereus, Bacillus  subtilis ,Enterobacter aerogenes, Enterococcus faecalis, Lactococcous lactis, Micoccocus luteus, Pseudomonas aeruginosa, Proteus vulgaris, Rhodococcus equi, Serratia marcesans and Staphylococcous aureus. It was observed that electromagnetic field (EMF) had significant effect on the bacterial load of the industrial effluent. Mean differences was considered significant at P≤0.05. Bacterial load decreases as the magnitude of the EMF increases with time. The physicochemical analysis of the raw and EMF treated effluents revealed that EMF treated effluent had lower mean values of physicochemical. This outcome of study shows that Electromagnetic field treatment of effluent is effective in reducing the bacterial load of food and dairy industrial effluents, hence making the effluent safe for the environment to which it will be discharged. The method for the treatment can be developed and modified for effective use in industrial settings which will be of great economic importance to food and dairy industries and waste water management of developing nations.
The Impact of Personal Selling on Consumer Buying
Authors: Samyuktha S. , Sreethulasi T. , Evangelin Andrea , Prabha Dr.D. Divya , Mathipurani Dr.V.B.
Published: April 2022

Every firm requires sales staff to help them advertise their products and services to customers through its sales representatives. In todays industry, sales promotion and distribution are critical components of success. As a result, it is critical to understand how far these marketing strategies are succeeding in raising brand awareness in the minds of customers and impacting them to purchase products and services. It is also necessary to improve the quality, creativity, and use of technology in the distribution and sales promotion processes. Main goal of the study is to examine the advertising and promotional strategies used by FMCG firms to advertise their products and services, as well as to determine which sales promotion techniques are the most effective for specific items offered by the companies under consideration. For this purpose, a sample of 150 respondents was gathered, and the data was analysed using percentage analysis, mean rank, and chi square as statistical tools. The findings revealed that while the companies have a reach towards the advertisements they produce, more effective measures must be implemented by the companies in order to make the advertisements more effective in the future.
Management Students Perception towards Entrepreneurship as a Career
Authors: Faizal Afraz , Saranyan Sethuraman Rathina Sai , Srinandh K , Sairagav S. , Prabha Dr.D. Divya
Published: April 2022

Student entrepreneurship is defined as the practice of seeking out novel solutions to societal problems while still in school. Individual student entrepreneurs take on the aim of creating and maintaining societal value, to be more precise. These individuals draw on appropriate thinking from both the business and nonprofit worlds, and they work in a wide range of organisations, including large and small organisations, new and old organisations, religious and secular organisations, nonprofit organisations, for-profit organisations, and hybrid organisations. The challenge is to determine why it is essential, what the scope of the problem is, what the contributing variables are, and what the underlying reasons are. The main objectives of this study is to analyse the characteristics of student entrepreneurs in the city of Coimbatore in order to fully understand the effects of student entrepreneurs on society and to unravel patterns in the behaviour of effective student entrepreneurs. This research will be conducted in the city of Coimbatore, India. Primary data will be collected from the respondents for this reason, and a sample size of 125 students who are currently employed as student entrepreneurs in Coimbatore would be utilized for the study. For the purpose of assessing the data, percentage analysis, chi-square analysis, and factor analysis will be employed as statistical tools. Following the analysis, conclusions about the research will be drawn in accordance with the findings of the study.
Investigation of the Structural Coating Homogeneity in Open‐Porous Nickel/Polyurethane Hybrid Foams Produced by Flow‐Controlled Electrodeposition
Authors: Kunz Francesco , Jung Anne
Published: April 2022

In today's world, the saving of raw materials together with the reduction of emissions necessitates the development of new, customized and application‐oriented materials which fulfill various requirements at the same time. Metal foams achieve a high strength combined with low weight. The present work deals with a flow‐controlled production technique for hybrid foams to deposit a nanocrystalline nickel (Ni) layer on pre‐treated, open‐porous polyurethane (PU) foams. The analysis of the resulting coating thickness distributions with gravimetric and microscopic methods shows the qualitative and quantitative influences on the local deposition by varying the process parameters. For the first time, the coating thickness distribution of Ni/PU hybrid foams is investigated regarding the analysis of a global and local homogeneity. The comparison of experimental data with simulated flow velocity profiles leads to an estimation of the correlation between flow velocity, anode distance, and coating thickness distribution, which represents the mass transport. The correlations show, that the coating process is strongly controlled by the electrolyte's flow velocity as well as the distribution of the electric field.
Natural Silk Spinning‐Inspired Meso‐Assembly‐Processing Engineering Strategy for Fabricating Soft Tissue‐Mimicking Biomaterials
Authors: Zhang Yuehua , Ye Shasha , Cao Leitao , Lv Zhuochen , Ren Jing , Shao Zhengzhong , Yao Yuan , Ling Shengjie
Published: April 2022

Natural silk spinning is the strategy used by spiders and silkworms to construct their ultra‐strong‐and‐tough silks. It can be considered as an optimized meso‐assembly processing engineering (MAPE) strategy that effectively coordinates molecular‐and‐supramolecular assembly and native spinning. Inspired by this process, this study develops a biomimetic MAPE strategy to fabricate biomaterials mimicking the structural and mechanical characteristics of biological tissues. The structural and mechanical mimetics are realized by synergistically integrating phase transition‐induced meso‐assembly and mechanical training‐induced structural remodeling. Through this approach, highly‐hydrated silk fibroin materials with exceptional tunable mechanical properties, such as softness, high stretchability (failure strain larger than 1200%), and high strength and toughness (strength of 5 ± 1 MPa, stiffness 18 ± 2 MPa, and toughness of 6 ± 1 MJ m−3) are produced. Thanks to their structural and mechanical tissue‐matching features, these biomimetic meso‐assembled materials exhibit advances in the modulation of different cell morphologies. The gradient architecture deformation (aspect ratio, spreading area, and perimeter) is evidenced, and the interplay between cytoskeleton (actin and tubulin) and matrix adaptation orientation is substantiated. These findings advance the application of silk fibroin biomaterials in the regulation of adaptive cell reconstruction, since the morphology of cells is the basis for their physiological functions.
Targeted Delivery of DNA Topoisomerase Inhibitor SN38 to Intracranial Tumors of Glioblastoma Using Sub‐5 Ultrafine Iron Oxide Nanoparticles
Authors: Li Yuancheng , Xie Manman , Jones Joshua B. , Zhang Zhaobin , Wang Zi , Dang Tu , Wang Xinyu , Lipowska Malgorzata , Mao Hui
Published: April 2022

Effectively delivering therapeutics for treating brain tumors is hindered by the physical and biological barriers in the brain. Even with the compromised blood–brain barrier and highly angiogenic blood–tumor barrier seen in glioblastoma (GBM), most drugs, including nanomaterial‐based formulations, hardly reach intracranial tumors. This work investigates sub‐5 nm ultrafine iron oxide nanoparticles (uIONP) with 3.5 nm core diameter as a carrier for delivering DNA topoisomerase inhibitor 7‐ethyl‐10‐hydroxyl camptothecin (SN38) to treat GBM. Given a higher surface‐to‐volume ratio, uIONP shows one‐ or three‐folds higher SN38 loading efficiency (48.3 ± 6.1%, mg/mg Fe) than those with core sizes of 10 or 20 nm. SN38 encapsulated in the coating polymer exhibits pH sensitive release with <10% over 48 h at pH 7.4, but 86% at pH 5, thus being protected from converting to inactive glucuronide by UDP‐glucuronosyltransferase 1A1. Conjugating αvβ3‐integrin‐targeted cyclo(Arg‐Gly‐Asp‐D‐Phe‐Cys) (RGD) as ligands, RGD‐uIONP/SN38 demonstrates targeted cytotoxicity to αvβ3‐integrin‐overexpressed U87MG GBM cells with a half‐maximal inhibitory concentration (IC50) of 30.9 ± 2.2 nm. The efficacy study using an orthotopic mouse model of GBM reveals tumor‐specific delivery of 11.5% injected RGD‐uIONP/SN38 (10 mg Fe kg−1), significantly prolonging the survival in mice by 41%, comparing to those treated with SN38 alone (p < 0.001).
Lensless Wavefront Parallel Processing of Vector Beams by Self‐Images of a Self‐Organized Q‐Plates Microarray
Authors: Sasaki Yuji , Yamazaki Kenji , Murakami Naoshi , Yamane Keisaku , Orihara Hiroshi
Published: April 2022

Wavefront shaping of structured light beams is attracting considerable attention in optics and related technologies. Due to the potential benefits, it is crucial to develop versatile methods for controlling the wavefront in a compact space with the capacity for high‐throughput parallel processing. Herein, a unique concept is introduced for converting the wavefront of multiple structured light beams, which are periodically packed in a microscopic area. An experimental demonstration is provided by using transmissive planar optical elements consisting of a microarray of geometric phase based on nematic liquid crystals. The periodic microstructure is fabricated by the directed self‐organization of topological defects present in a nanoscale relief obtained by area‐selective surface modification. The conversion of multiple wavefronts is realized by using the Talbot self‐imaging effect of the microarray. The integrated geometric phase microarray has potential applications in vortex beam emitters to harness structured light, such as for optical manipulation and lithography.
Tunable Broadband Photoresponse Electron‐Emission Nanostructure: Metasurface‐Extended Spectrum‐Selecting and Plasmon‐Enhanced Emitting
Authors: Shen Yan , Han Yuchen , Chen Huanjun , Xu Ningsheng , Deng Shaozhi
Published: April 2022

Exploring novel nanotechnology schemes for tunable broadband vacuum photodetection devices is of great significance. Herein, a strategy to combine a field‐emission cold cathode with plasmonic nanostructures to form a plasmon‐enhanced field‐emission metasurface array is proposed. Mo nanostructures with excellent emission properties act as field‐emission cold cathode materials. Au nanospheres are applied to enhance the photocurrent of Mo nanopyramid emitters and to generate tunable resonance responses by plasmonic couplings. The response frequency and polarization can be selective in a broadband range from visible to near‐infrared, which originates from the periodic couplings of the Mo–Mo microcavities and the Au–Mo interfaces in the designed metasurface emitter arrays. The amplitude of photodetection signals is experimentally demonstrated to be tunable not only by the geometrical dimensions of the Mo nanopyramid and the number of decorated Au plasmons, but also by the applied external electrostatic fields. This plasmon‐enhanced photoresponse field‐emission process is attributed to plasmon‐mediated electron emission. Herein, a route to tunable broadband photoresponse electron‐emission nanostructures at room temperature (≈300 K) and low energy consumption for photocathode and vacuum device applications is provided in the results.
Cells‐Micropatterning Biomaterials for Immune Activation and Bone Regeneration
Authors: Zhang Bingjun , Han Fei , Wang Yufeng , Sun Yuhua , Zhang Meng , Yu Xiaopeng , Qin Chen , Zhang Hongjian , Wu Chengtie
Published: April 2022

Natural tissues are composed of ordered architectural organizations of multiple tissue cells. The spatial distribution of cells is crucial for directing cellular behavior and maintaining tissue homeostasis and function. Herein, an artificial bone bioceramic scaffold with star‐, Tai Chi‐, or interlacing‐shaped multicellular patterns is constructed. The “cross‐talk” between mesenchymal stem cells (MSCs) and macrophages can be effectively manipulated by altering the spatial distribution of two kinds of cells in the scaffolds, thus achieving controllable modulation of the scaffold‐mediated osteo‐immune responses. Compared with other multicellular patterns, the Tai Chi pattern with a 2:1 ratio of MSCs to macrophages is more effective in activating anti‐inflammatory M2 macrophages, improving MSCs osteogenic differentiation, and accelerating new bone formation in vivo. In brief, the Tai Chi pattern generates a more favorable osteo‐immune environment for bone regeneration, exhibiting enhanced immunomodulation and osteogenesis, which may be associated with the activation of BMP‐Smad, Oncostatin M (OSM), and Wnt/β‐catenin signaling pathways in MSCs mediated by macrophage‐derived paracrine signaling mediators. The study suggests that the manipulation of cell distribution to improve tissue formation is a feasible approach that can offer new insights for the design of tissue‐engineered bone substitutes with multicellular interactions.
Constructing Complementary Catalytic Components on Co4N Nanowires to Achieve Efficient Hydrogen Evolution Catalysis
Authors: Han Dongdong , Cai Jinyan , Xie Yufang , Wu Yishang , Niu Shuwen , Zang Yipeng , Pan Hongge , Qu Wengang , Wang Gongming , Qian Yitai
Published: April 2022

Cobalt nitrides with a high ratio of cobalt–cobalt interaction have been extensively explored as electrocatalysts for hydrogen evolution reaction (HER) catalysis. However, the tilted orbital orientation and limited empty d‐orbitals above the Fermi level (EF) result in unfavorable water adsorption/activation. Herein, facile interfacial engineering by in situ growing of MoN particles on Co4N nanowire arrays to explore the interfacial synergistic mechanism for boosting HER catalysis is developed. The overpotential of the prepared MoN–Co4N at 10 mA cm−2 is only 45.1 mV, which is substantially better than the pristine Co4N (207 mV). According to density functional theory (DFT) calculations, MoN with vertical orbital orientation and more empty d‐orbitals above EF contributes to water adsorption and activation, while the Co4N surface is responsible for the adsorption/desorption of the intermediate H. Understanding the synergistic effects of each catalytic component at the atomic levels offers valuable insights for rational design of efficient HER catalysts and beyond.
Solution Processing via Dynamic Sulfide Radical Anions for Sulfide Solid Electrolytes
Authors: Gamo Hirotada , Nishida Jin , Nagai Atsushi , Hikima Kazuhiro , Matsuda Atsunori
Published: April 2022

Solution processing technology for the manufacturing of all‐solid‐state batteries (ASSBs) holds great promise of scalability and low cost over ball milling and solid‐state methods. However, conventional liquid‐phase synthesis for solid electrolytes has yet to translate into large‐scale manufacturing to address commercialization challenges. Herein, solution processing via dynamic sulfide radical anions is developed, providing rapid and scalable manufacturing of Li7P3S11 solid electrolytes (SEs). A mixture of Li2S, P2S5, and excess elemental sulfur in a mixed solvent of acetonitrile, tetrahydrofuran, and ethanol forms a homogenous precursor solution containing the S3
·− radical anion. The presence of ethanol enhances the chemical stability of S3
·−. The resulting sulfide radical anions serve as a mediator with two strategies: the soluble polysulfide formation and activation of P2S5, and thus allows the generation of the precursor solution in 2 min. The Li7P3S11 is prepared in 2 h without the need for ball milling or high‐energy treatment, which shows higher ionic conductivity (1.2 mS cm−1 at 25 °C) and excellent cell performance of ASSBs cells than Li7P3S11 prepared by ball milling. The solution processing technology reported here paves the way for the accelerated adoption of practical ASSBs manufacturing.
Traceless Benzylic C−H Amination via BifunctionalN‐Aminopyridinium Intermediates
Authors: Roychowdhury Pritam , Herrera Roberto G. , Tan Hao , Powers David C.
Published: April 2022

C−H amination reactions provide the opportunity to streamline the synthesis of nitrogen‐containing organic small molecules. The impact of intermolecular C−H amination methods, however, is currently limited the frequent requirement for the amine precursors to bear activating groups, such asN‐sulfonyl substituents, that are both challenging to remove and not useful synthetic handles for subsequent derivatization. Here, we introduce traceless nitrogen activation for C−H amination—which enables application of selective C−H amination chemistry to the preparation of diverseN‐functionalized products—via sequential benzylic C−HN‐aminopyridylation followed by Ni‐catalyzed C−N cross‐coupling with aryl boronic acids. Unlike many C−H amination reactions that provide access to protected amines, the current method installs an easily diversifiable synthetic handle that serves as a lynchpin for C−H amination, deaminative N−N functionalization sequences.
In Vivo Production of Diverse β‐Amino Acid‐Containing Proteins
Authors: Lakis Edgars , Magyari Sarolt , Piel Jörn
Published: April 2022

The wide range of moieties installed in ribosomally synthesized and post‐translationally modified peptides (RiPPs) suggests largely untapped potential for protein engineering. However, many RiPP maturases recognize target peptide precursors through an N‐terminal leader sequence that is challenging to adapt to proteins. We have recently reported a family of enzymes that splice XYG sites in RiPPs to install α‐keto‐β‐amino acids. Backbone modifications influence diverse protein properties, yet the toolkit to install β‐amino acids is limited. Here we report their leader‐independent incorporation into proteins in E. coli. Integrating an 11‐residue splice tag into six different proteins permitted the site‐selective introduction of β‐residues in vivo. The motif fusion at C‐, N‐terminal, and internal positions yielded various β‐residues. Our approach complements the few existing methods to introduce β‐amino acids or ketone‐bearing moieties, suggesting diverse applications in chemical biology.
Silver‐Templated γ‐Keggin Alkyltin‐Oxo Cluster: Electronic Structure and Optical Limiting Effect
Authors: Zhu Yu , Wang Zirui , Li Dejing , Zhu Yin‐Di , Li Qiao‐Hong , Li Dong‐Sheng , Zhang Lei
Published: April 2022

As one of the most representative polyoxometalate (POM) structures, Keggin clusters have attracted considerable attention. Nevertheless, the noble‐metal‐templated Keggin structure has not been reported to date. In this work, for the first time, a Ag atom was successfully incorporated to template the formation of a γ‐Keggin alkytin‐oxo cluster. Moreover, the central Ag atom has brought a significant heavy atom effect, showing the important influence on the electronic structure and optical properties. Theoretical calculations demonstrate that the Ag atom affects the frontier molecular orbitals and excited states of the AgSn12 cluster, and also the process of electron transfer. The solid structure of the AgSn12 cluster exhibits a significant third‐order nonlinear optical (NLO) response, and an excellent optical limiting effect has been experimentally verified. The success of this work opens the way for the construction and optical properties modulation of noble metal templated Keggin structures.
Saving the Energy Loss in Lithium‐Mediated Nitrogen Fixation by Using a Highly Reactive Li3N Intermediate for C−N Coupling Reactions
Authors: Chen Gao‐Feng , Savateev Aleksandr , Song Zihan , Wu Haoyu , Markushyna Yevheniia , Zhang Lili , Wang Haihui , Antonietti Markus
Published: April 2022

Direct synthesis of N‐containing organic compounds from dinitrogen (N2) can make synthetic chemistry more sustainable. Previous bottlenecks in lithium‐mediated N2fixation were resolved by loading Li‐metal anodes covered with the typical Li+ion‐conducting solid electrolyte interface, which are subsequently allowed to react with N2. The developed strategy allowed us to reach high Faradaic efficiencies toward Li3N. These reactive Li3N were then contacted with acylchlorides. Surface nitride ions are more nucleophilic than amines which direct the two C−N coupling reactions toward formation of imides rather than amides, and an integrated current efficiency of 57–77 % could be realized. This study thereby not only provides a feasible electrochemical Li3N synthesis, but also delineates an economical and green synthesis of highly valuable N‐containing compounds from N2under mild conditions, just using commercial spare parts and processes from the omnipresent Li battery technology.
Controlling Reaction Routes in Noble‐Metal‐Catalyzed Conversion of Aryl Ethers
Authors: Schmid Julian , Wang Meng , Gutiérrez Oliver Y. , Bullock R. Morris , Camaioni Donald M. , Lercher Johannes A.
Published: April 2022

Hydrogenolysis and hydrolysis of aryl ethers in the liquid phase are important reactions for accessing functionalized cyclic compounds from renewable feedstocks. On supported noble metals, hydrogenolysis is initiated by a hydrogen addition to the aromatic ring followed by C−O bond cleavage. In water, hydrolysis and hydrogenolysis proceed by partial hydrogenation of the aromatic ring prior to water or hydrogen insertion. The mechanisms are common for the studied metals, but the selectivity to hydrogenolysis increases in the order Pd<Rh<Ir<Ru≈Pt in decalin and water; the inverse was observed for the selectivity to hydrolysis in water. Hydrogenolysis selectivity correlates with the Gibbs free energy of hydrogen adsorption. Hydrogenolysis has the highest standard free energy of activation and a weak dependence on H2 pressure, thus, the selectivity to hydrogenolysis is maximized by increasing temperature and decreasing H2 pressure. Selectivity to C−O bond cleavage reaches >95 % in water and alkaline conditions.
Site‐Selective Pyridylic C−H Functionalization by Photocatalytic Radical Cascades
Authors: Kim Myojeong , You Euna , Kim Jieun , Hong Sungwoo
Published: April 2022

An efficient pyridylic C(sp3)−H functionalization has been developed through photocatalytic radical‐mediated fluoroalkylation or cascade reactions. This method is enabled by the reversible formation of alkylidene dihydropyridine intermediates via the facile enolate formation of C4‐alkylN‐amidopyridinium salts in the absence of an external base, thereby establishing the conditions necessary for subsequent intermolecular radical trapping. Rapid structural diversification of the pyridylic site can be achieved through photocatalytic multicomponent cascade reactions involving alkene trifluoromethylation, SO2‐reincorporation, and sulfonyl radical addition. This operationally simple method features a broad substrate scope and high chemoselectivity and offers a unique approach for the rational modification of the heterobenzylic C−H bonds of pyridines and quinolines with uniform site‐selective control. Furthermore, experimental and theoretical studies were performed to elucidate the reaction mechanism.
Recent Breakthroughs in P4 Chemistry: Towards Practical, Direct Transformations into P1 Compounds
Authors: Scott Daniel J.
Published: April 2022

For several decades, academic researchers have been intensively studying the chemistry of white phosphorus (P4) in the hope of developing direct methods for its transformation into useful P‐containing products. This would bypass the hazardous, multistep procedures currently relied on by industry. However, while academically interesting P4 activation reactions have become well established, their elaboration into useful, general synthetic procedures has remained out of reach. Very recently, however, a series of independent reports has begun to change this state of affairs. Each shows how relatively simple and practical synthetic methods can be used to access academically or industrially relevant P1 compounds from P4 directly, in “one pot” or even in a catalytic fashion. These reports mark a step change in the field of P4 chemistry, and suggest its possible transition from an area of largely academic interest to one with the promise of true synthetic relevance.
Unravelling the Turn‐On Fluorescence Mechanism of a Fluorescein‐Based Probe in GABAA Receptors
Authors: Singer Nadja K. , Sánchez‐Murcia Pedro A. , Ernst Margot , González Leticia
Published: April 2022

GABAA (γ‐aminobutyric acid type A) receptors are ligand‐gated ion channels mediating fast inhibitory transmission in the mammalian brain. Here we report the molecular and electronic mechanism governing the turn‐on emission of a fluorescein‐based imaging probe able to target the human GABAA receptor. Multiscale calculations evidence a drastic conformational change of the probe from folded in solution to extended upon binding to the receptor. Intramolecular ππ‐stacking interactions present in the folded probe are responsible for quenching fluorescence in solution. In contrast, unfolding within the GABAA receptor changes the nature of the bright excited state triggering emission. Remarkably, this turn‐on effect only manifests for the dianionic prototropic form of the imaging probe, which is found to be the strongest binder to the GABAA receptor. This study is expected to assist the design of new photoactivatable screening tools for allosteric modulators of the GABAA receptor.
Disorder–Order Conversion‐Induced Enhancement of Thermal Stability of Pyroxene Near‐Infrared Phosphors for Light‐Emitting Diodes
Authors: Wen Dawei , Liu Hongmin , Guo Yue , Zeng Qingguang , Wu Mingmei , Liu Ru Shi
Published: April 2022

The minimization of thermal quenching, which leads to luminescence loss at high temperatures, is one of the most important issues for near‐infrared phosphors. In the present work, we investigated the properties of near‐infrared Ca(Sc,Mg)(Al, Si)O6 : Cr3+ phosphors with a pyroxene‐type structure under blue light excitation. The CaScAlSiO6 : Cr3+ end member of Ca(Sc,Mg)(Al,Si)O6 : Cr3+ phosphor led to broadband emission at a full‐width half maximum of 215 nm, whereas the CaMgSi2O6 : Cr3+ end member exhibited high thermal stability at 150 °C, with an intensity of 88.4 % of that at room temperature. The structural analysis and density functional theory calculations revealed the absence of soft conformations and local space confinement contributed to the high structural rigidity and weakened the thermal quenching effect.
Neochamaejasmin B extracted from Stellera chamaejasme L. induces apoptosis through caspase‐10‐dependent way in insect neuronal cells
Authors: Gu Guirong , Jiang Mingfang , Hu Hanying , Qiao Weijie , Jin Hong , Hou Taiping , Tao Ke
Published: April 2022

To explore the toxicity mechanisms of neochamaejasmin B (NCB) extracted from Stellera chamaejasme L., we first evaluated its cytotoxicity in neuronal cells of Helicoverpa zea (AW1 cells). NCB inhibited cell growth and was cytotoxic to AW1 cells in a dose‐dependent manner. Further, transmission electron microscopy (TEM) was used to analyze the microstructure, and typical apoptotic characteristics were observed in AW1 cells treated with NCB. Moreover, the NCB‐induced apoptosis was dose dependent. Subsequently, we explored the mechanism of apoptosis. A decline in the mitochondrial membrane potential (MMP) was found. Also, the levels of Bax were increased with increases in drug concentration, but there was no statistical difference in Bcl‐2 levels at different NCB doses. Caspase‐3 and caspase‐10 activity was increased. These findings confirmed that NCB induced apoptosis in AW1 cells through a caspase‐10‐dependent mechanism. The results provide the basic information needed for understanding the toxicity and mechanisms of action of NCB, which could potentially be used to develop NCB as a new insecticide.
An Aluminum‐Benzo[1,2‐b:4,5‐b’]dithiophene‐4,8‐dione Organic Rechargeable Battery Featuring Low Self‐Discharge
Authors: Wang Yijia , Long Ng Kok , Azimi Gisele
Published: April 2022

The achievable cell‐level specific energy density of existing aluminum‐ion batteries (AIBs) employing AlCl4− intercalation type cathodes is intrinsically limited by the chloroaluminate anolyte. Towards achieving AIBs with higher specific energy, it is imperative to explore alternative cell chemistries that fundamentally tap the capacity of Al metal anode. Here, we report a benzo[1,2‐b:4,5‐b’]dithiophene‐4,8‐dione (BDTD) organic electrode material with favorable AlCl2+ intercalation mechanism. This BDTD cathode delivers a specific capacity of 143 mAh g−1, and the resulting battery exhibits a well‐defined voltage plateau at ∼1.2 V. This characteristic voltage plateau is mainly driven by the predominant diffusive charge storage in BDTD cathode, which accounts for up to 85 % of the total charge‐storage contribution. As a result, the BDTD cathode demonstrates exceptional self‐discharging resistance by recovering >95 % of its capacity upon 24‐h resting.