bluuebunny/crossref_metadata_2025 huggingface dataset:
A Ge-based Schottky diode for 2.45 G weak energy microwave wireless energy transmission based on crystal orientation optimization and Sn alloying technology
Authors: Song Jian-Jun , Zhang Long-Qiang , Chen Lei , Zhou Liang , Sun Lei , Lan Jun-Feng , Xi Chu-Hao , Li Jia-Hao ,   State Key Laboratory of Nuclear Power Safety Monitoring Technology and Equipment, Shenzhen 518172, China,   Beijing Microelectronics Technology Institute, Beijing 100076, China,   School of Microelectronics, Xidian University, Xi’an 710071, China
Published: May 2021

With the development of modern communication technology, unlimited energy harvesting technology has become more and more popular. Among them, the weak energy density wireless energy harvesting technology has broken through the limitations in traditional transmission lines and can use the “waste” energy in the environment, which has become very popular. The Schottky diode is the core device of the 2.45 G weak energy density wireless energy harvesting system, and its performance determines the upper limit of the system's rectification efficiency. From the material design point of view, using crystal orientation optimization technology and Sn alloying technology, we propose and design a Ge-based compound semiconductor with large effective mass, large affinity, and high electron mobility. On this basis, the device simulation tool is further used to set reasonable device material physical parameters and geometric structure parameters, and a Ge-based Schottky diode for 2.45 G weak energy microwave wireless energy transmission is realized. The simulation of the ADS rectifier circuit based on the SPICE model of the device shows that comparing with the conventional Schottky diode, the turn-on voltage of the device is reduced by about 0.1 V, the zero-bias capacitance is reduced by 6 fF, and the reverse saturation current is also significantly increased. At the same time, the designed new Ge-based Schottky diode is used as the core rectifier device to simulate the rectifier circuit. The results show that the new-style Ge-based Schottky diode is in the weak energy working area with input energy in a range of –10 — –20 dBm. The energy conversion efficiency is increased by about 10%. The technical solutions and relevant conclusions of this article can provide a useful reference for solving the problem of low rectification efficiency of the 2.45 G weak energy density wireless energy harvesting system.
Dygdsetikk i møte med etiske dilemma i den kliniske kvardagen
Authors: Korsvoll Anne Guro , Thorkildsen Kari Marie
Published: May 2021

Omsorgsutøvarar møter dagleg etiske dilemma, og ei innebygd handlingsforventning fører ofte til at ein må ta val basert på personleg intuisjon meir enn systematisk refleksjon. Hensikten med artikkelen er å sjå kva dygder som hjelper og styrker omsorgsutøvaren i møte med etiske dilemma i den kliniske kvardagen. Det vart gjennomført eitt fokusgruppeintervju med seks omsorgsutøvarar frå ulike avdelingar i ein sjukeheim, og data vart analysert i trå med den fenomenologisk-hermeneutiske metoden til Lindseth og Norberg. Dygder, eller fråver av desse, kjem fram i følgjande tema å sjå situasjonen i ein større heilskap, å vekse i lag med andre, å vekse i seg sjølv, å kjenne seg åleine og å søke noko anna. Dygda fronesis, der bevisstgjort og tilegna kunnskap og erfaring vert aktualisert i den enkelte situasjon, kan hjelpe omsorgsutøvaren til å stå styrka i møte med etiske dilemma i den kliniske kvardagen.

Virtue ethics facing ethical dilemmas in clinical practice

Everyday care practitioners encounter ethical dilemmas, and situations that  require intervention often make the care practitioner base her choices on personal  intuition rather than systematical reflection. This article explores which virtues  help and strengthen the care practitioner in ethical dilemmas in her clinical  practice. Six care practitioners from different wards in a nursing home participated in one focus group interview, and the data was analyzed according to Lindseth and Norberg´s (2004) phenomenological-hermeneutical method. Virtues, or the  absence of them, appear in the following themes; to grow as an individual, to grow together with others, to feel alone, to seek something else, and to see the situation in a larger context. Phronesis as a virtue, where conscious and appropriated knowledge and experience are actualized in every single situation, can help the care practitioner to better meet ethical dilemmas in clinical practice.
Type of organic fertilizer rather than organic amendment per se increases abundance of soil biota
Authors: Viketoft Maria , Riggi Laura G.A. , Bommarco Riccardo , Hallin Sara , Taylor Astrid R.
Published: May 2021

Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.
Algunos problemas sobre el concepto de “tecnología” en el diseño: Entrevista a David Edgerton
Authors:   King's College London, Edgerton David , Palmarola Hugo ,   Pontificia Universidad Católica de Chile, Álvarez Caselli Pedro ,   Pontificia Universidad Católica de Chile
Published: May 2021

En esta entrevista, Edgerton critica el alcance de los estudios CTS (Ciencia, Tecnología y Sociedad) dentro del diseño, apuntando a la redundancia de aplicar perspectivas que resultan obvias para una disciplina que se ocupa de la invención y el uso. Además, señala que debemos abandonar el concepto de “tecnología” y reemplazarlo con términos más descriptivos, precisos y útiles.
Is Living in Mwanza Region More Economically Better and Happier than Living in Kagera Region? Finite Mixture (FIMIX) Approach
Authors: Bundala Ntogwa N. , Ngaruko Deus Dominic P. , Lyanga Timothy M.
Published: May 2021

The study aimed to uncover the unobserved heterogeneity of the population in Mwanza and Kagera regions. The study examined if living in Mwanza region is more economically better and happier than living in Kagera region. The cross-sectional survey research used with the cross-sectional data from 211 individuals sampled randomly from 4 districts, Nyamagana and Misungwi from Mwanza region, and Bukoba and Muleba from Kagera region. The FIMIX-PLS used to analyse the data. The study found that the population of Mwanza and Kagera regions can be grouped into two mains classes which are class one with a lower annualised income below 1.5 TZS millions per capita and a lower mean score of fundamental psychological factors for happiness (FPFH) in comparing to the class two. The class two is characterised with a higher annualised income about 2.45 TZS millions per capita and a higher mean score of FPFH in comparing to class one. The study evidenced that respondents of Mwanza region have a higher annualised income and FPFH scores than respondents of Kagera region in each class. Therefore, the study concluded that living in Mwanza region is more economically better and happier than living in Kagera region. The study recommended the immigration to seek the economic opportunity and happiness, for example immigration from Kagera region to Mwanza region or nation to nation is encouraged. Moreover, further study recommended by using a panel data to attest the posed facts because this study limited to the cross-sectional data.
Comprehensive Survey for Cloud Computing Based Nature-Inspired Algorithms Optimization Scheduling
Authors: Yahia Hazha Saeed , Zeebaree Subhi R. M. , Sadeeq Mohammed A. M. , Salim Nareen O. M. , Kak Shakir Fattah , AL-Zebari Adel , Salih Azar Abid , Hussein Helat Ahmed
Published: May 2021

Many applications in the real world include optimizing specific targets, such as cost minimization, energy conservation, climate, and maximizing production, efficiency, and sustainability. The optimization problem is strongly non-linear with multifunctional landscapes under several dynamic, non-linear constraints in some instances. It is challenging to address those issues. Also, with the increasing strength of modern computers, simplistic brute force methods are still inefficient and unwanted. Practical algorithms are also vital for these implementations whenever possible.

Cloud computing has become an essential and popular emerging computing environment that supports on-demand services and provides internet-based services. Cloud computing allows a range of services and tools to be easily accessed from anywhere in the world. Since cloud computing has global access to its services, there will always be threats and challenges facing its servers and services, such as; task scheduling, security, energy efficiency, network load, and other challenges. In the research area, many algorithms have been addressed to solve these problems. This paper investigates relevant analysis and surveys on the above topics, threats, and outlooks. This paper offers an overview of nature-inspired algorithms, their applications, and valuation, emphasizing cloud computing problems. Many problems in science and engineering can be viewed as optimization problems with complex non-linear constraints. Highly nonlinear solutions typically need advanced optimization algorithms, and conventional algorithms can have difficulty addressing these issues. Because of its simplicity and usefulness, nature-inspired algorithms are currently being used. There are nevertheless some significant concerns with computing and swarming intelligence influenced by evolution.
Antimicrobial, Antioxidant and Antiproliferative Properties of the Leaves of Senna siamea
Authors: Oyebade K. F. , Daspan A. J. , Denkok Y. , Alemika T. E. , Ojerinde O. S.
Published: May 2021

The aim of this study was to investigate the antimicrobial, antioxidant and antiproliferative activities of leaves of Senna siamea. A sequential solvent extraction procedure was used in extracting powdered Senna leaves, starting with hexane, ethylacetate, ethanol and distilled water, respectively. Dry extracts obtained were tested at various concentrations against Pseudomonas aeruginosa, staphylococcus aureus, Salmonella typhi and Candida albicans. Antioxidant (Qualitative and quantitative) and antiproliferative tests were carried out on samples of the dry extracts. Ethylacetate extract of Senna siamea showed the highest antibacterial activity against S. typhi (zone of inhibition 15.0 mm) at concentration of 500mg/ml. The aqueous extract had the highest antioxidant activity, evidenced by a low IC50 value of 12.89µg/ml. Antiproliferative activity was determined by calculating the percentage inhibition of germination of Sorghum bicolor L. seeds under appropriate conditions. Plants that inhibit seed germination may inhibit tumour growth. At 24 hours, the plant showed strong antiproliferative activity as evidenced by the high percentage inhibition. Ethanolic extract had the highest antiproliferative activity (90%) at 5000µg/ml, followed by the aqueous extract (88.5%). However, at 48 hours, all organic extracts showed very weak antiproliferative activity as evidenced by the low % inhibition. Only the aqueous extract showed considerable antiproliferative activity at 5000µg/ml (45%). This implies that the aqueous extract has considerable antiproliferative activity, hence, it may be a promising anticancer drug or has components that have anticancer properties. This shows that Senna leaves could serve as source of bioactive compounds with potential antimicrobial, antioxidant and anticancer properties.
Scanning Electron Microscopic Evaluation of Marginal Adaptation of Three Endodontic Sealers: An Ex-Vivo Study
Authors: Padmawar Neeta , Moapagr Viddyasagar , Vadvadgi Vinay , Vishwas Jayshree , Joshi Sourabh , Padubidri Meghna
Published: May 2021

Introduction: To avoid the entry of micro-organism or their products, sealer should completely adapt to the root canal wall so that no gaps will be present. AH plus is the most routinely used sealer. EndoRez is methacrylate resin-based self as well as light cured sealer. Endosequence BC RCS is the recently introduced bioceramic based sealer.

Aim: To evaluate the marginal adaptation of Endosequence BS RCS, EndoRez and AH plus as a root canal sealer to root dentin under electron scanning microscope.

Methods: Total 75 freshly extracted permanent maxillary central incisors with single canal were included in this study. All the teeth were decoronated till twelve millimeter and access cavity was prepared. All the teeth were prepared with rotary protaper till# F3 with intermediate copious irrigation with 3% sodium hypochlorite and 17%EDTA.Teeth were randomly divided into three groups according to sealers and were obturated- Endosequence BC RCS, Ah Plus and EndoRez. Access cavity was restored with glass ionomer type II in all the groups. After seven days, teeth were vertically sectioned and evaluated under electron scanning microscope for marginal adaptation.

Results: Marginal gaps were present in all groups. Maximum number of gaps were present in Ah plus group. Endosequence BC RCS group showed least number of gaps.

Discussion: Marginal adaptation of sealer depends upon the properties like flow, viscosity, presence or absence of smear layer etc. Better adaptation of Endosequence BC RCS to root dentin is due to formation of mineral infiltration zone which results in formation of calcific tags in dentine.

Conclusion: Within the limitation of present study, newly introduced Endosequence BC RCS showed better marginal adaptability to root dentine. Further studies are required to evaluate and corelate these findings with other properties of these sealers.
One Size Does Not Fit All: An Overview of Personalized Treatment in Cancer
Authors: Kulavi Sohini , Ghosh Chandreyi , Saha Moumita , Chatterjee Sirshendu
Published: May 2021

The last few decades have witnessed 'one size fits all' kind of conventional treatment strategy i.e. a similar line of treatment or usage of the same drug to treat a particular disease. This approach is not associated with specific personal characteristics but with individual genetic constitutions. Precision oncology holds great opportunities to improve prediction, treatment and follow-up care for the benefit of cancer patients. In this study, many pieces of literature and various clinical data have been surveyed to understand how multiple genes are responsible for a particular cancer type and tabulate them. Having the genetic information of a patient and knowing the genes that are susceptible to mutation can help in the diagnosis. That in turn help to get the most tailored medicines, which will decrease the chances of treatment failure, which is quite common in cancer therapies. This review focuses on providing an idea of the genes whose mutation directly or indirectly can lead to cancer and other diseases also, and hence might be helpful to design separate treatment strategies for each individual in future.
Multiple Heterogeneous Information Source
Authors: Raj A. Anto Lourdu Xavier , Macrino A. Mairo
Published: May 2021

Today, this fault location analysis is completed within the digital signal processing method. Scenario packet transmission source of some of the attacks and intruders get data packets, and route alters identity problem before cumulative. Reduces processing time can find significant speed advantage and the accuracy of the classical method of calculation failure and presents a simple analog implementation. Back-propagation time is modeled as a fault location estimation of each repeated signature and the switches along with the network. Rapid Packet Transmission Algorithm (RPTA) by a certain load distribution, which leads to restrictions to avoid packet loss. Due to increased packet transmission, improving technology to limit non-destructive testing costs is in great demand. Our algorithm means that each candidate seriously and error detection mechanisms and can provide any fault tolerance of the routing path assessment. Simulation results with different fault resistance indicate that these methods are robust, fault-type, and the initial angle of the disorder. To find the faulty segment, use the transient to the common connection point. Good accuracy for complex network topologies also reduces the overhead generation region by implication checking logic; thus, compared to the typical failure locations of the techniques developed to reduce the total number of required effects, this solution charm.
Playing cancer at its own game: activating mitogenic signaling as a paradoxical intervention
Authors: Dias Matheus Henrique , Bernards René
Published: May 2021

In psychotherapy, paradoxical interventions are characterized by a deliberate reinforcement of the pathological behavior to improve the clinical condition. Such a counter‐intuitive approach can be considered when more conventional interventions fail. The development of targeted cancer therapies has enabled the selective inhibition of activated oncogenic signaling pathways. However, in advanced cancers, such therapies, on average, deliver modest benefits due to the development of resistance. Here, we review the perspective of a ‘paradoxical intervention’ in cancer therapy: rather than attempting to inhibit oncogenic signaling, the proposed therapy would further activate mitogenic signaling to disrupt the labile homeostasis of cancer cells and overload stress response pathways. Such overactivation can potentially be combined with stress‐targeted drugs to kill overstressed cancer cells. Although counter‐intuitive, such an approach exploits intrinsic and ubiquitous differences between normal and cancer cells. We discuss the background underlying this unconventional approach and how such intervention might address some current challenges in cancer therapy.
Monte Carlo study of TG‐43 dosimetry parameters of GammaMed Plus high dose rate 192Ir brachytherapy source using TOPAS
Authors: Wu Jianan , Xie Yaoqin , Ding Zhen , Li Feipeng , Wang Luhua
Published: May 2021

Purpose

To develop a simulation model for GammaMed Plus high dose rate 192Ir brachytherapy source in TOPAS Monte Carlo software and validate it by calculating the TG‐43 dosimetry parameters and comparing them with published data.

Methods

We built a model for GammaMed Plus high dose rate brachytherapy source in TOPAS. The TG‐43 dosimetry parameters including air‐kerma strength SK, dose‐rate constant Λ, radial dose function gL(r), and 2D anisotropy function F(r,θ) were calculated using Monte Carlo simulation with Geant4 physics models and NNDC 192Ir spectrum. Calculations using an old 192Ir spectrum were also carried out to evaluate the impact of incident spectrum and cross sections. The results were compared with published data.

Results

For calculations using the NNDC spectrum, the air‐kerma strength per unit source activity SK/A and Λ were 1.0139 × 10‐7 U/Bq and 1.1101 cGy.h−1.U−1, which were 3.56% higher and 0.62% lower than the reference values, respectively. The gL(r) agreed with reference values within 1% for radial distances from 2 mm to 20 cm. For radial distances of 1, 3, 5, and 10 cm, the agreements between F(r,θ) from this work and the reference data were within 1.5% for 15° < θ < 165°, and within 4% for all θ values. The discrepancies were attributed to the updated source spectrum and cross sections. They caused deviations of the SK/A of 2.90% and 0.64%, respectively. As for gL(r), they caused average deviations of −0.22% and 0.48%, respectively. Their impact on F(r,θ) was not quantified for the relatively high statistical uncertainties, but basically they did not result in significant discrepancies.

Conclusion

A model for GammaMed Plus high dose rate 192Ir brachytherapy source was developed in TOPAS and validated following TG‐43 protocols, which can be used for future studies. The impact of updated incident spectrum and cross sections on the dosimetry parameters was quantified.
Genetically Encoding Light‐Responsive Protein‐Polymers Using Translation Machinery for the Multi‐Site Incorporation of Photo‐Switchable Unnatural Amino Acids
Authors: Israeli Bar , Strugach Daniela S. , Gelkop Sigal , Weber Shir , Gozlan Dor S. , Amiram Miriam
Published: May 2021

A general and versatile technology to engineer light‐responsive protein‐based biomaterials can enable the manipulation and interrogation of proteins, pathways, and cells, and it will assist the design of “smart” light‐responsive biomaterials. This study reports the evolution of chromosomal aminoacyl‐tRNA synthetases (aaRSs) for azobenzene‐bearing unnatural amino acids (uAAs) with up to ≈40‐fold increased protein production and improved fidelity, as compared with a previously described aaRS. The evolved translation systems enable efficient and accurate incorporation of up to 10 instances of the various light‐responsive uAAs in elastin‐like polypeptides (ELPs). Azobenzene‐containing ELPs are capable of isothermal, reversible, light‐mediated soluble‐to‐insoluble phase transition, with up to a 12  °C difference in the ELP transition temperature upon cis‐to‐trans azobenzene isomerization. Furthermore, the incorporation of azobenzene‐uAAs in ELP diblock‐copolymers enables the creation of light‐responsive self‐assembled nanostructures. Finally, light‐responsive resilin‐inspired polymers are also generated by multi‐site azobenzene‐incorporation. The translation machinery evolved in this study can be used for the multi‐site incorporation of azobenzene moieties at the polypeptide level and constitute a universal methodology for the design of light‐responsive proteins and additional families of protein‐based biomaterials with customized and tunable light‐responsive behavior.
Brønsted Base‐Catalyzed Tandem [2+4] Annulation/Tautomerization/Aromatization Reaction of α‐Alkylidene Succinimides with 5‐Alkenyl Thiazolones
Authors: Yuan Chunhao , Yang Huimin , Gong Qi , Luo Shan , Gu Jing , Ge Yanqing , Guo Hongchao , Xie Lei
Published: May 2021

A Brønsted base‐catalyzed tandem [2+4] annulation/tautomerization/aromatization reaction of α‐alkylidene succinimides with 5‐alkenyl thiazolones has been developed for synthesis of functionalized thiazolo pyrones under mild conditions. The prepared thiazolo pyrones show fluorescent properties.

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Thermal and Humidity Stability of Mixed Spacer Cations 2D Perovskite Solar Cells
Authors: Yu Huayang , Xie Yulin , Zhang Jia , Duan Jiashun , Chen Xu , Liang Yudong , Wang Kai , Xu Ling
Published: May 2021

In this article, two different types of spacer cations, 1,4‐butanediamonium (BDA2+) and 2‐phenylethylammonium (PEA+) are co‐used to prepare the perovskite precursor solutions with the formula of (BDA)1‐a(PEA2)aMA4Pb5X16. By simply mixing the two spacer cations, the self‐assembled polycrystalline films of (BDA)0.8(PEA2)0.2MA4Pb5X16 are obtained, and BDA2+ is located in the crystal grains and PEA+ is distributed on the surface. The films display a small exciton binding energy, uniformly distributed quantum wells and improved carrier transport. Besides, utilizing mixed spacer cations also induces better crystallinity and vertical orientation of 2D perovskite (BDA)0.8(PEA2)0.2MA4Pb5X16 films. Thus, a power conversion efficiency (PCE) of 17.21% is achieved in the optimized perovskite solar cells with the device structure of ITO/PEDOT:PSS/Perovskite/PCBM/BCP/Ag. In addition, the complementary humidity and thermal stability are obtained, which are ascribed to the enhanced interlayer interaction by BDA2+ and improved moisture resistance by the hydrophobic group of PEA+. The encapsulated devices are retained over 95% or 75% of the initial efficiency after storing 500 h in ambient air under 40 ± 5% relative humidity or 100 h in nitrogen at 60 °C.
Defect Passivation of CsPbBr3 with AgBr for High‐Performance All‐Inorganic Perovskite Solar Cells
Authors: Chen Shoulong , Liu Xiaolin , Wang Zhen , Li Wenhui , Gu Xiaoyu , Lin Jia , Yang Tieying , Gao Xingyu , Kyaw Aung Ko Ko
Published: May 2021

CsPbBr3‐based perovskite solar cells possess both high humidity and temperature tolerance, and also have excellent long‐term stability in air, but the defect states in the bulk perovskite are always an obstacle for further improvement of their efficiency. Herein, a doping strategy is demonstrated in which AgBr is directly added to the precursor solution in the first step. An appropriate amount of Ag+ ion doping can passivate the defects in bulk or at grain boundaries, reduce the defect density of the film, and form a pinhole‐free film. Finally, the best power conversion efficiency of the solar cell reaches to 6.92% and exhibits a long‐term stability in a humid environment. This work provides a simple and effective method for improving the quality of CsPbBr3 film and the performance of CsPbBr3‐based perovskite solar cells.
Metal‐Free Electrocatalysts for Oxygen Reduction to Hydrogen Peroxide
Authors: Wang Zhe , James Dustin K. , Tour James M.
Published: May 2021

Hydrogen peroxide (H2O2), as an environmentally friendly and highly efficient oxidation reagent, is now widely and increasingly used in many areas. The traditional anthraquinone synthesis process, however, is energy and capital intensive with low efficiency. Electrochemically reducing oxygen (O2) to H2O2 with metal‐free catalysts is considered a promising alternative. This work describes the two‐electron oxygen reduction process from both thermodynamic and kinetic aspects and summarizes the designing rules for effective H2O2 formation catalysts. This includes tuning the binding energy of the intermediate species, the concentration of dissociation active sites, and adjusting the dielectric constant of solvents. These principles are successfully applied to the design of various metal‐free catalysts by proper structure engineering and heteroatom doping, which shows both high activity and efficiency. Furthermore, pH and temperature effects are presented with a view toward reaction optimization. An outlook of future challenges is also discussed.
Mechanophore activation enhanced by hydrogen bonding of diarylurea motifs: An efficient supramolecular force‐transducing system
Authors: Kida Jumpei , Aoki Daisuke , Otsuka Hideyuki
Published: May 2021

Macromolecules are efficient as mechanical transducers for mechanically induced chemical bond cleavage reactions. Although various classes of polymers have been studied as effective mechanical‐force transducers for mechanophores, alternatives to polymer chains, that is, small molecules, have rarely been studied. In this paper, the role of hydrogen bonding as small‐molecule mechanical‐force transducers for the activation of mechano‐responsive molecular units (mechanophores) in the bulk is investigated. The introduction of diarylurea linkage motifs, which are known as strong hydrogen bonding groups, enhances the mechanochemical activation of the fluorescent mechanophore tetraarylsuccinonitrile (TASN) as effectively as the attachment of a typical macromolecular transducer. Electron paramagnetic resonance measurements of mechanically activated TASN with diphenyl urea motifs demonstrate its higher carbon–carbon bond dissociation ratio compared to that of TASN without diphenyl urea motifs. This efficient supramolecular‐force‐transducing system represents a new concept in the field of mechanochemistry, namely, the enhancement of mechanochemical bond scission by simply changing the substituents of a mechanophore, even in small molecules.
High‐Output Force Electrohydraulic Actuator Powered by Induced Interfacial Charges
Authors: Kim Hyunwoo , Ma Jihyeong , Kim Minki , Nam Jongseok , Kyung Ki-Uk
Published: May 2021

Herein, a novel soft actuator design is presented that simultaneously enables a high‐output force at a low operating voltage and an adjustable large normal displacement. The electrohydraulic actuator powered by induced interfacial charge (EPIC) uses the amplified electrostatic force when the surface charge‐inducing phenomenon of the polyvinyl chloride (PVC) gel and the geometrical gradient of the actuator are combined to reinforce the zipping motion of the liquid layer. This actuator produces a more than 50‐fold higher blocking force than conventional dielectric liquid‐coupled electrostatic actuators at 2 kV. This implies the possibility of expanding the applicability of soft actuators to high‐power transducers. This actuator is modeled as parallel capacitors by considering the interfacial‐induced charge; the ratio of the dielectric constant of the polymer film to that of the dielectric liquid is analyzed as the principal design criterion for optimizing the performance characteristics. The actuator prototype exerts a force as high as 16 times its body weight (25.5 g) and exhibits a large normal displacement of more than 20% of its height (8.5 mm). Furthermore, four actuators can lift a weight of 1.25 kg and one actuator can be used as a large‐aperture (diameter: 30 mm) varifocal lens (374% focal length variation).
Comprehensive Analysis of Binding Sites in Tubulin
Authors: Mühlethaler Tobias , Gioia Dario , Prota Andrea E. , Sharpe May E. , Cavalli Andrea , Steinmetz Michel O.
Published: May 2021

Tubulin plays essential roles in vital cellular activities and is the target of a wide range of proteins and ligands. Here, using a combined computational and crystallographic fragment screening approach, we addressed the question of how many binding sites exist in tubulin. We identified 27 distinct sites, of which 11 have not been described previously, and analyzed their relationship to known tubulin–protein and tubulin–ligand interactions. We further observed an intricate pocket communication network and identified 56 chemically diverse fragments that bound to 10 distinct tubulin sites. Our results offer a unique structural basis for the development of novel small molecules for use as tubulin modulators in basic research applications or as drugs. Furthermore, our method lays down a framework that may help to discover new pockets in other pharmaceutically important targets and characterize them in terms of chemical tractability and allosteric modulation.
Head‐to‐Tail Oligomerization by Silylene‐Tethered Sonogashira Coupling on Ag(111)
Authors: Sun Kewei , Sagisaka Keisuke , Peng Lifen , Watanabe Hikaru , Xu Feng , Pawlak Rémy , Meyer Ernst , Okuda Yasuhiro , Orita Akihiro , Kawai Shigeki
Published: May 2021

On‐surface synthesis is a powerful method for the fabrication of π‐conjugated nanomaterials. Herein, we demonstrate chemoselective Sonogashira coupling between (trimethylsilyl)ethynyl and chlorophenyl groups in silylethynyl‐ and chloro‐substituted partially fluorinated phenylene ethynylenes (SiCPFPEs) on Ag(111). The desilylative Sonogashira coupling occurred with high chemoselectivity up to 75 %, while the competing Ullmann and desilylative Glaser homocoupling reactions were suppressed. A combination of bond‐resolved scanning tunneling microscopy/atomic force microscopy (STM/AFM) and DFT calculations revealed that the oligomers were obtained by the formation of intermolecular silylene tethers (‐Me2Si‐) through CH3−Si bond activation at 130 °C and subsequent elimination of the tethers at an elevated temperature of 200 °C.
Formulating the Electrolyte Towards High‐Energy and Safe Rechargeable Lithium–Metal Batteries
Authors: Ma Qiang , Yue Junpei , Fan Min , Tan Shuang‐Jie , Zhang Juan , Wang Wen‐Peng , Liu Yuan , Tian Yi‐Fan , Xu Quan , Yin Ya‐Xia , You Ya , Luo An , Xin Sen , Wu Xiong‐Wei , Guo Yu‐Guo
Published: May 2021

Rechargeable lithium–metal batteries with a cell‐level specific energy of >400 Wh kg−1 are highly desired for next‐generation storage applications, yet the research has been retarded by poor electrolyte–electrode compatibility and rigorous safety concerns. We demonstrate that by simply formulating the composition of conventional electrolytes, a hybrid electrolyte was constructed to ensure high (electro)chemical and thermal stability with both the Li‐metal anode and the nickel‐rich layered oxide cathodes. By employing the new electrolyte, Li∥LiNi0.6Co0.2Mn0.2O2 cells show favorable cycling and rate performance, and a 10 Ah Li∥LiNi0.8Co0.1Mn0.1O2 pouch cell demonstrates a practical specific energy of >450 Wh kg−1. Our findings shed light on reasonable design principles for electrolyte and electrode/electrolyte interfaces toward practical realization of high‐energy rechargeable batteries.
Discovery of a Low Thermal Conductivity Oxide Guided by Probe Structure Prediction and Machine Learning
Authors: Collins Christopher M. , Daniels Luke M. , Gibson Quinn , Gaultois Michael W. , Moran Michael , Feetham Richard , Pitcher Michael J. , Dyer Matthew S. , Delacotte Charlene , Zanella Marco , Murray Claire A. , Glodan Gyorgyi , Pérez Olivier , Pelloquin Denis , Manning Troy D. , Alaria Jonathan , Darling George R. , Claridge John B. , Rosseinsky Matthew J.
Published: May 2021

We report the aperiodic titanate Ba10Y6Ti4O27 with a room‐temperature thermal conductivity that equals the lowest reported for an oxide. The structure is characterised by discontinuous occupancy modulation of each of the sites and can be considered as a quasicrystal. The resulting localisation of lattice vibrations suppresses phonon transport of heat. This new lead material for low‐thermal‐conductivity oxides is metastable and located within a quaternary phase field that has been previously explored. Its isolation thus requires a precisely defined synthetic protocol. The necessary narrowing of the search space for experimental investigation was achieved by evaluation of titanate crystal chemistry, prediction of unexplored structural motifs that would favour synthetically accessible new compositions, and assessment of their properties with machine‐learning models.
Degradation in Order: Simple and Versatile One‐Pot Combination of Two Macromolecular Concepts to Encode Diverse and Spatially Regulated Degradability Functions
Authors: Fuoco Tiziana
Published: May 2021

The clever one‐pot combination of two macromolecular concepts, ring‐opening polymerization (ROP) and step‐growth polymerization (SGP), is demonstrated to be a simple, yet powerful tool to design a library of sequence‐controlled polymers with diverse and spatially regulated degradability functions. ROP and SGP occur sequentially at room temperature when the organocatalytic conditions are switched from basic to acidic, and each allows the encoding of specific degradable bonds. ROP controls the sequence length and position of the degradability functions, while SGP between the complementary vinyl ether and hydroxyl chain‐ends enables the formation of acetal bonds and high‐molar‐mass copolymers. The result is the rational combination of cleavable bonds prone to either bulk or surface erosion within the same macromolecule. The strategy is versatile and offers higher chemical diversity and level of control over the primary structure than current aliphatic polyesters or polycarbonates, while being simple, effective, and atom‐economical and having potential for scalability.
Rational Design and Engineering of One‐Dimensional Hollow Nanostructures for Efficient Electrochemical Energy Storage
Authors: Fang Yongjin , Luan Deyan , Gao Shuyan , Lou Xiong Wen (David)
Published: May 2021

The unique structural characteristics of one‐dimensional (1D) hollow nanostructures result in intriguing physicochemical properties and wide applications, especially for electrochemical energy storage applications. In this Minireview, we give an overview of recent developments in the rational design and engineering of various kinds of 1D hollow nanostructures with well‐designed architectures, structural/compositional complexity, controllable morphologies, and enhanced electrochemical properties for different kinds of electrochemical energy storage applications (i.e. lithium‐ion batteries, sodium‐ion batteries, lithium‐sulfur batteries, lithium‐selenium sulfur batteries, lithium metal anodes, metal‐air batteries, supercapacitors). We conclude with prospects on some critical challenges and possible future research directions in this field. It is anticipated that further innovative studies on the structural and compositional design of functional 1D nanostructured electrodes for energy storage applications will be stimulated.
1,1,2‐Ethenetriol: The Enol of Glycolic Acid, a High‐Energy Prebiotic Molecule
Authors: Mardyukov Artur , Keul Felix , Schreiner Peter R.
Published: May 2021

As low‐temperature conditions (e.g. in space) prohibit reactions requiring large activation energies, an alternative mechanism for follow‐up transformations of highly stable molecules involves the reactions of higher energy isomers that were generated in a different environment. Hence, one working model for the formation of larger organic molecules is their generation from high‐lying isomers of otherwise rather stable molecules. As an example, we present here the synthesis as well as IR and UV/Vis spectroscopic identification of the previously elusive 1,1,2‐ethenetriol, the higher energy enol tautomer of glycolic acid, a rather stable and hence unreactive biological building block. The title compound was generated in the gas phase by flash vacuum pyrolysis of tartronic acid at 400 °C and was subsequently trapped in argon matrices at 10 K. The spectral assignments are supported by B3LYP/6–311++G(2d,2p) computations. Upon photolysis at λ=180–254 nm, 1,1,2‐ethenetriol rearranges to glycolic acid and ketene.
Azacalix[3]triazines: A Substructure of Triazine‐Based Graphitic Carbon Nitride Featuring Anion‐π Interactions
Authors: Gong Hao , Zhang Cheng , Ogaki Takuya , Inuzuka Hiroyuki , Hashizume Daisuke , Miyajima Daigo
Published: May 2021

Graphitic carbon nitride (GCN) has garnered broad research interest due to its unique catalytic properties. However, GCN, prepared by general methods, possesses myriad structural defects and it has been difficult to elucidate their intrinsic physical properties. We report the development of azacalix[3]triazines (AC3Ts), a substructure of triazine‐based GCN (Tz‐GCN). Despite the electron‐deficient natures of triazine, AC3Ts capture protons as organic superbases. We reveal the unique anion‐π interactions of AC3Ts that alters the ionization potentials of AC3Ts. To the best of our knowledge, these features have not yet been recognized for Tz‐GCN. These unveiled features of AC3Ts are expected to expand the usage scope and possibilities for GCNs.
Dioxygen Activation and Pyrrole α‐Cleavage with Calix[4]pyrrolato Aluminates: Enzyme Model by Structural Constraint
Authors: Sigmund Lukas Maximilian , Ehlert Christopher , Enders Markus , Graf Jürgen , Gryn'ova Ganna , Greb Lutz
Published: May 2021

The present work describes the reaction of triplet dioxygen with the porphyrinogenic calix[4]pyrrolato aluminates to alkylperoxido aluminates in high selectivity. Multiconfigurational quantum chemical computations disclose the mechanism for this spin‐forbidden process. Despite a negligible spin–orbit coupling constant, the intersystem crossing (ISC) is facilitated by singlet and triplet state degeneracy and spin–vibronic coupling. The formed peroxides are stable toward external substrates but undergo an unprecedented oxidative pyrrole α‐cleavage by ligand aromatization/dearomatization‐initiated O−O σ‐bond scission. A detailed comparison of the calix[4]pyrrolato aluminates with dioxygen‐related enzymology provides insights into the ISC of metal‐ or cofactor‐free enzymes. It substantiates the importance of structural constraint and element–ligand cooperativity for the functions of aerobic life.
Monumental funerary landscapes of Dhar Tagant (south‐eastern Mauritania): Towards ethical satellite remote sensing in the West African Sahel
Authors: Linares Matás Gonzalo J. , Lim Jonathan S.
Published: May 2021

The remembrance of the dead is a ubiquitous dimension of most human societies, and the spatial dimension of mortuary practices actively constitutes an essential element of the cultural significance of certain places in the landscape. The visual prominence of stone‐built funerary monuments in dry upland areas is particularly conducive to their multiscalar study through above‐ground remote sensing methods. In this paper, we characterize the nature and distribution of Late Holocene drystone funerary monuments in the Dhar Tagant region of south‐eastern Mauritania using freely available, very high‐resolution (VHR) satellite imagery. We contextualize them in relation to the monumental mortuary records of Senegal and Mali within the West African Sahel, exploring their similarities and differences with other monumental funerary landscapes in semi‐arid environments. Ethical considerations and a self‐reflective attitude must be at the forefront of archaeological research, and we discuss the ethics of remote sensing research in the study of funerary practices in Africa, as well as the opportunities and challenges for remote collaborative engagement with local communities in the context of fieldwork restrictions.
Risk of COVID‐19 in Rheumatoid Arthritis: A National Veterans Affairs Matched Cohort Study in At‐Risk Individuals
Authors: England Bryant R. , Roul Punyasha , Yang Yangyuna , Kalil Andre C. , Michaud Kaleb , Thiele Geoffrey M. , Sauer Brian C. , Baker Joshua F. , Mikuls Ted R.
Published: May 2021

Objective

Rheumatoid arthritis (RA) and its treatments are associated with an increased risk of infection, but it remains unclear whether these factors have an impact on the risk or severity of COVID‐19. The present study was undertaken to assess the risk and severity of COVID‐19 in a US Department of Veterans Affairs (VA) cohort of patients with RA and those without RA.

Methods

A matched cohort study using national VA data was conducted. Patients diagnosed as having RA were identified among nondeceased individuals who were active in the VA health care system as of January 1, 2020 and who had received care in a VA medical center in 2019; patients for whom no RA diagnostic code was indicated were matched to the RA patients (1:1) by age, sex, and VA site (non‐RA controls). Patients diagnosed as having COVID‐19 and those with severe COVID‐19 (defined as requiring hospitalization or leading to death) were ascertained from a national VA COVID‐19 surveillance database through December 10, 2020. Multivariable Cox models were used to compare the risk of COVID‐19 and COVID‐19 hospitalization or death between RA patients and non‐RA controls, after adjusting for demographic characteristics, comorbidities, health care utilization and access, and county‐level COVID‐19 incidence rates.

Results

This VA cohort of RA patients and non‐RA controls (n = 33,886 subjects per group) predominantly comprised male patients (84.5%), and the mean age was 67.8 years. During follow‐up, 1,503 patients in the cohort were diagnosed as having COVID‐19; among them, 388 patients had severe COVID‐19 (hospitalization or death), while in 228 patients, the deaths were not related to COVID‐19. In the multivariable model, RA was associated with a higher risk of COVID‐19 (adjusted hazard ratio [HR] 1.25 [95% confidence interval (95% CI) 1.13–1.39]) and a higher risk of COVID‐19 hospitalization or death (adjusted HR 1.35 [95% CI 1.10–1.66]) as compared to non‐RA controls. Use of disease‐modifying antirheumatic drugs and prednisone, as well as self‐reported Black race, self‐reported Hispanic ethnicity, and presence of several chronic conditions, but not seropositivity for RA autoantibodies, were each associated with risk of COVID‐19 and severe COVID‐19 (hospitalization or death).

Conclusion

Patients with RA are at higher risk of developing COVID‐19 and severe COVID‐19 (leading to hospitalization or death) compared to those without RA. With a risk of COVID‐19 that approaches that of other recognized chronic conditions, these findings suggest that RA patients should be prioritized for COVID‐19 prevention and management strategies.
Association between spectral electroencephalography power and autism risk and diagnosis in early development
Authors: Huberty Scott , Carter Leno Virginia , van Noordt Stefon J. R. , Bedford Rachael , Pickles Andrew , Desjardins James A. , Webb Sara Jane ,   The BASIS Team, Elsabbagh Mayada
Published: May 2021

Autism spectrum disorder (ASD) has its origins in the atypical development of brain networks. Infants who are at high familial risk for, and later diagnosed with ASD, show atypical activity in multiple electroencephalography (EEG) oscillatory measures. However, infant‐sibling studies are often constrained by small sample sizes. We used the International Infant EEG Data Integration Platform, a multi‐site dataset with 432 participants, including 222 at high‐risk for ASD, from whom repeated measurements of EEG were collected between the ages of 3–36 months. We applied a latent growth curve model to test whether familial risk status predicts developmental trajectories of spectral power across the first 3 years of life, and whether these trajectories predict ASD outcome. Change in spectral EEG power in all frequency bands occurred during the first 3 years of life. Familial risk, but not a later diagnosis of ASD, was associated with reduced power at 3 months, and a steeper developmental change between 3 and 36 months in nearly all absolute power bands. ASD outcome was not associated with absolute power intercept or slope. No associations were found between risk or outcome and relative power. This study applied an analytic approach not used in previous prospective biomarker studies of ASD, which was modeled to reflect the temporal relationship between genetic susceptibility, brain development, and ASD diagnosis. Trajectories of spectral power appear to be predicted by familial risk; however, spectral power does not predict diagnostic outcome above and beyond familial risk status. Discrepancies between current results and previous studies are discussed.

Lay Summary

Infants with an older sibling who is diagnosed with ASD are at increased risk of developing ASD themselves. This article tested whether EEG spectral power in the first year of life can predict whether these infants did or did not develop ASD.