bluuebunny/crossref_metadata_2025 huggingface dataset:
Z‐Scheme 2D/2D Heterojunction of CsPbBr3/Bi2WO6 for Improved Photocatalytic CO2 Reduction
Authors: Jiang Yong , Chen Hong‐Yan , Li Jun‐Yan , Liao Jin‐Feng , Zhang Hong‐Hong , Wang Xu‐Dong , Kuang Dai‐Bin
Published: September 2020

Heterojunction engineering, especially 2D/2D heterojunctions, is regarded as a quite promising strategy to manipulate the photocatalytic performance of semiconductor catalysts. In this manuscript, a direct Z‐scheme 2D/2D heterojunction of CsPbBr3/Bi2WO6 is designed and fabricated by a simple electrostatic self‐assembly process. By using ultrathin nanosheets with several atomic layers as the building blocks, a close CsPbBr3/Bi2WO6 heterointerface over large area with quite a short charge transport distance is obtained, which enables a valid Z‐scheme interfacial charge transfer between Bi2WO6 and CsPbBr3 and thus boosts charge separation. The CsPbBr3/Bi2WO6 heterojunction exhibits a superior photocatalytic performance toward CO2 reduction. By incorporating Pt nanoparticles as the cocatalyst, a high photoelectron consumption rate of 324.0 µmol g−1 h−1 under AM 1.5G irradiation (150 mW cm−2) is obtained, which is 12.2 fold higher than that of CsPbBr3 nanosheets. Moreover, a stable product yield of up to 1582.0 µmol g−1 and electron consumption yield of 8603.0 µmol g−1 for photocatalytic CO2 reduction to CO (11.4%) and CH4 (84.3%) can be achieved after 30 h of continuous catalytic reaction. The accelerated photogenerated charge transfer and spatial charge separation are investigated in detail by ultrafast spectra, photoelectrochemical test, and Kelvin probe force microscopy.
Bifunctional 3D Hierarchical Hairy Foam toward Ultrastable Lithium/Sulfur Electrochemistry
Authors: Zeng Zhipeng , Li Wei , Chen Xiujuan , Liu Xingbo
Published: September 2020

The dendrite formation resulting from the irregular lithium deposition and the infinite volume expansion in lithium anodes significantly impede their commercialization for high energy applications. Herein, it is demonstrated that carbon nanofibers (CNFs) grown in situ on a nickel foam (CNF@Ni) can locally change the Li stripping/plating behavior by reducing the nucleation overpotential and regulating the electric field distribution. The 3D conductive hairy foam with a hierarchical structure can provide sufficient active sites for lithium nucleation. In addition, the numerous CNFs with protuberant tips can act as the charge centers and significantly increase the electrochemically active surface area, resulting in the locally reduced and uniformly distributed current density. The symmetric cells using CNF@Ni‐Li electrodes can achieve ultralong lifespan with low voltage hysteresis up to 1000 h. More remarkably, the CNF@Ni hairy foam can simultaneously enable reliable sulfur electrochemistry. The corresponding Li‐S full cell shows excellent cycle stability with a high capacity of ≈400 mAh g−1 at 5 C after 800 cycles. This work provides an exemplary way to concurrently address the challenges in lithium and sulfur electrodes toward the development of high‐performance Li–S batteries.
Long‐Term Retention of Low‐Power, Nonvolatile Organic Transistor Memory Based on Ultrathin, Trilayered Dielectric Containing Charge Trapping Functionality
Authors: Lee Changhyeon , Pak Kwanyong , Choi Junhwan , Kim Min Ju , Cho Byung Jin , Im Sung Gap
Published: September 2020

A new strategy for multilayer stacking using charge trapping layer (CTL) is proposed and a new CTL material is synthesized, which contains a trilayer dielectric with the total thickness less than 28 nm, deposited by initiated chemical vapor deposition (iCVD) process. 2.6 nm thick poly(1,3,5‐trimethyl‐1,3,5‐trivinyl cyclotrisiloxane) (pV3D3) and 19 nm thick poly(1,4‐butanediol diacrylate) (pBDDA) are employed as tunneling and blocking dielectric layers, respectively. A 6 nm thick ultrathin charge trapping layer containing hydroxyl group is inserted between the tunneling and the blocking layers for stable, long‐term memory operation. For this purpose, a homogeneous copolymer of 1,4‐butanediol diacrylate and 2‐hydroxyethyl acrylate is newly synthesized. The fabricated memory with the trilayer dielectric shows larger than 5.8 V of memory window at low programming/erasing voltage of 16 V. The retention characteristics of the low‐power organic memory device is improved significantly with the drain current decrease less than 0.40 order after 108 s, corresponding to one of the longest retention time periods obtained from organic NVM reported to date. The low‐power organic NVM could also be integrated on flexible substrate, which is fully operational even under 2.72% of applied strain.
Contact Aging Enhances Adhesion of Micropatterned Silicone Adhesives to Glass Substrates
Authors: Thiemecke Jonathan , Hensel René
Published: September 2020

The transfer of biological concepts into synthetic micropatterned adhesives has recently enabled a new generation of switchable, reversible handling devices. Over the last two decades, many design principles have been explored that helped to understand the underlying mechanics and to optimize such adhesives for certain applications. An aspect that has been overlooked so far is the influence of longer hold times on the adhesive contacts. Exemplarily, the pull‐off stress and work of separation of a micropatterned adhesive specimen are enhanced by factors 3 and 6, respectively, after 1000 min in contact with a glass substrate. In addition to such global measures, the increase of adhesion of all individual micropillars is analyzed. It is found that contact aging varied across the microarray, as it drastically depends on local conditions. Despite great differences on the micropillar scale, the adhesion of entire specimens increased with very similar power laws, as this is determined by the mean contact ageing of the individual structures. Overall, contact aging must be critically evaluated before using micropatterned adhesives, especially for long‐term fixations and material combinations that are chemically attractive to each other.
Structural Manipulation of Phase Transitions by Self‐Induced Strain in Geometrically Confined Thin Films
Authors: Kalcheim Yoav , Adda Coline , Salev Pavel , Lee Min‐Han , Ghazikhanian Nareg , Vargas Nicolás M. , del Valle Javier , Schuller Ivan K.
Published: September 2020

Strain engineering is a well‐known method often used to tune material properties in thin films. The most studied sources of strain are lattice mismatch and differential thermal contraction between the substrate and film. However, in materials which undergo a structural phase transition (SPT), a third and often overlooked source of strain may play a very significant role. If the substrate confines the area of the film, the SPT may induce stress which changes the evolution of the transition. This is a 2D analog of the isochoric phase transition between water and ice, where the freezing point drops below 0 °C. To illustrate this, the prototypical Mott insulator V2O3 which has an SPT coupled to a metal–insulator transition is used to show how self‐induced strain can drastically alter structural and electronic properties. This effect provides an elegant approach for mapping the phase diagram of the SPT and the transitions coupled to it. Moreover, the magnitude of self‐straining is tunable by modifying the substrate morphology. This effect may be important for numerous materials which exhibit an SPT and are subjected to geometrical constraints.
Highly Sensitive InSb Nanosheets Infrared Photodetector Passivated by Ferroelectric Polymer
Authors: Zhang Shukui , Jiao Hanxue , Wang Xudong , Chen Yan , Wang Hailu , Zhu Liqing , Jiang Wei , Liu Jingjing , Sun Liaoxin , Lin Tie , Shen Hong , Hu Weida , Meng Xiangjian , Pan Dong , Wang Jianlu , Zhao Jianhua , Chu Junhao
Published: September 2020

Indium antimony is a direct, narrow bandgap III–V semiconductor with ultrahigh carrier mobility and an attractive optoelectronic device candidate for use in the visible to infrared region. Here, an infrared (IR) photodetector based on high‐quality InSb nanosheets (NSs) is presented, which shows a clear photoresponse over a broad spectral range from visible (637 nm) to infrared (4.3 µm). Due to the high surface‐to‐volume ratio of nanostructured materials, defects on the sample surface can affect performance, which is a disadvantage for the ambipolar InSb photodetectors. To eliminate the impact of sample surface defects on performance, the surface of the sample is passivated with a ferroelectric film and the mechanism of increased sensitivity is explored. After covering the protective layer, the performance of the detector is greatly improved. The responsivity and detectivity of the photodetector are 311.5 AW−1 and 9.8 × 109 Jones, respectively. Compared with devices before passivation, the dark current is two orders of magnitude lower, the responsivity is 20 times higher, and the photoresponse time is shortened from seconds to the order of milliseconds. These InSb NSs with their outstanding photoelectric properties have great potential for developing next‐generation nanoscale optoelectronic devices.
Flexible/Stretchable Supercapacitors with Novel Functionality for Wearable Electronics
Authors: Keum Kayeon , Kim Jung Wook , Hong Soo Yeong , Son Jeong Gon , Lee Sang‐Soo , Ha Jeong Sook
Published: September 2020

With the miniaturization of personal wearable electronics, considerable effort has been expended to develop high‐performance flexible/stretchable energy storage devices for powering integrated active devices. Supercapacitors can fulfill this role owing to their simple structures, high power density, and cyclic stability. Moreover, a high electrochemical performance can be achieved with flexible/stretchable supercapacitors, whose applications can be expanded through the introduction of additional novel functionalities. Here, recent advances in and future prospects for flexible/stretchable supercapacitors with innate functionalities are covered, including biodegradability, self‐healing, shape memory, energy harvesting, and electrochromic and temperature tolerance, which can contribute to reducing e‐waste, ensuring device integrity and performance, enabling device self‐charging following exposure to surrounding stimuli, displaying the charge status, and maintaining the performance under a wide range of temperatures. Finally, the challenges and perspectives of high‐performance all‐in‐one wearable systems with integrated functional supercapacitors for future practical application are discussed.
Metal‐Free Halide Perovskite Single Crystals with Very Long Charge Lifetimes for Efficient X‐ray Imaging
Authors: Song Xin , Cui Qingyue , Liu Yucheng , Xu Zhuo , Cohen Hagai , Ma Chuang , Fan Yuanyuan , Zhang Yunxia , Ye Haochen , Peng Zhanhui , Li Ruipeng , Chen Yonghua , Wang Jianpu , Sun Huaming , Yang Zhou , Liu Zhike , Yang Zupei , Huang Wei , Hodes Gary , Liu Shengzhong (Frank) , Zhao Kui
Published: September 2020

Metal‐free halide perovskites, as a specific category of the perovskite family, have recently emerged as novel semiconductors for organic ferroelectrics and promise the wide chemical diversity of the ABX3 perovskite structure with mechanical flexibility, light weight, and eco‐friendly processing. However, after the initial discovery 17 years ago, there has been no experimental information about their charge transport properties and only one brief mention of their optoelectronic properties. Here, growth of large single crystals of metal‐free halide perovskite DABCO‐NH4Br3 (DABCO = N‐N′‐diazabicyclo[2.2.2]octonium) is reported together with characterization of their instrinsic optical and electronic properties and demonstration, of metal‐free halide perovskite optoelectronics. The results reveal that the crystals have an unusually large semigap of ≈16 eV and a specific band nature with the valence band maximum and the conduction band minimum mainly dominated by the halide and DABCO2+, respectively. The unusually large semigap rationalizes extremely long lifetimes approaching the millisecond regime, leading to very high charge diffusion lengths (tens of μm). The crystals also exhibit high X‐ray attenuation as well as being lightweight. All these properties translate to high‐performance X‐ray imaging with sensitivity up to 173 μC Gyair−1 cm−2. This makes metal‐free perovskites novel candidates for the next generation of optoelectronics.
The Experimentalist's Guide to the Cycloid, or Noncollinear Antiferromagnetism in Epitaxial BiFeO3
Authors: Burns Stuart R. , Paull Oliver , Juraszek Jean , Nagarajan Valanoor , Sando Daniel
Published: September 2020

Bismuth ferrite (BiFeO3) is one of the most widely studied multiferroics. The coexistence of ferroelectricity and antiferromagnetism in this compound has driven an intense search for electric‐field control of the magnetic order. Such efforts require a complete understanding of the various exchange interactions that underpin the magnetic behavior. An important characteristic of BiFeO3 is its noncollinear magnetic order; namely, a long‐period incommensurate spin cycloid. Here, the progress in understanding this fascinating aspect of BiFeO3 is reviewed, with a focus on epitaxial films. The advances made in developing the theory used to capture the complexities of the cycloid are first chronicled, followed by a description of the various experimental techniques employed to probe the magnetic order. To help the reader fully grasp the nuances associated with thin films, a detailed description of the spin cycloid in the bulk is provided. The effects of various perturbations on the cycloid are then described: magnetic and electric fields, doping, epitaxial strain, finite size effects, and temperature. To conclude, an outlook on possible device applications exploiting noncollinear magnetism in BiFeO3 films is presented. It is hoped that this work will act as a comprehensive experimentalist's guide to the spin cycloid in BiFeO3 thin films.
An Antioxidant Enzyme Therapeutic for COVID‐19
Authors: Qin Meng , Cao Zheng , Wen Jing , Yu Qingsong , Liu Chaoyong , Wang Fang , Zhang Jianjun , Yang Fengmei , Li Yanyan , Fishbein Gregory , Yan Sen , Xu Bin , Hou Yi , Ning Zhenbo , Nie Kaili , Jiang Ni , Liu Zhen , Wu Jun , Yu Yanting , Li Heng , Zheng Huiwen , Li Jing , Jin Weihua , Pang Shen , Wang Shuai , Chen Jianfeng , Gan Zhihua , He Zhanlong , Lu Yunfeng
Published: September 2020

The COVID‐19 pandemic has taken a significant toll on people worldwide, and there are currently no specific antivirus drugs or vaccines. Herein it is a therapeutic based on catalase, an antioxidant enzyme that can effectively breakdown hydrogen peroxide and minimize the downstream reactive oxygen species, which are excessively produced resulting from the infection and inflammatory process, is reported. Catalase assists to regulate production of cytokines, protect oxidative injury, and repress replication of SARS‐CoV‐2, as demonstrated in human leukocytes and alveolar epithelial cells, and rhesus macaques, without noticeable toxicity. Such a therapeutic can be readily manufactured at low cost as a potential treatment for COVID‐19.
Synergistic Interface‐Assisted Electrode–Electrolyte Coupling Toward Advanced Charge Storage
Authors: Sun Shuo , Rao Dewei , Zhai Teng , Liu Qi , Huang Hao , Liu Bo , Zhang Hongshen , Xue Liang , Xia Hui
Published: September 2020

Owing to the limited charge storage capability of transitional metal oxides in aqueous electrolytes, the use of redox electrolytes (RE) represents a promising strategy to further increase the energy density of aqueous batteries or pseudocapacitors. The usual coupling of an electrode and an RE possesses weak electrode/RE interaction and weak adsorption of redox moieties on the electrode, resulting in a low capacity contribution and fast self‐discharge. In this work, Fe(CN)64− groups are grafted on the surface of Co3O4 electrode via formation of CoN bonds, creating a synergistic interface between the electrode and the RE. With such an interface, the coupled Co3O4–RE system exhibits greatly enhanced charge storage from both Co3O4 and RE, delivering a large reversible capacity of ≈1000 mC cm−2 together with greatly reduced self‐discharge. The significantly improved electrochemical activity of Co3O4 can be attributed to the tuned work function via charge injection from Fe(CN)64−, while the greatly enhanced adsorption of K3Fe(CN)6 molecules is achieved by the interface induced dipole–dipole interaction on the liquid side. Furthermore, this enhanced electrode–electrolyte coupling is also applicable in the NiO–RE system, demonstrating that the synergistic interface design can be a general strategy to integrate electrode and electrolyte for high‐performance energy storage devices.
Bandgap Renormalization in Monolayer MoS2 on CsPbBr3 Quantum Dots via Charge Transfer at Room Temperature
Authors: Adhikari Subash , Kim Ji‐Hee , Song Bumsub , Doan Manh‐Ha , Tran Minh Dao , Gomez Leyre , Kim Hyun , Gul Hamza Zad , Ghimire Ganesh , Yun Seok Joon , Gregorkiewicz Tom , Lee Young Hee
Published: September 2020

Many‐body effect and strong Coulomb interaction in monolayer transition metal dichalcogenides lead to intrinsic bandgap shrinking, originating from the renormalization of electrical/optical bandgap, exciton binding energy, and spin‐orbit splitting. This renormalization phenomenon has been commonly observed at low temperature and requires high photon excitation density. Here, the augmented bandgap renormalization (BGR) in monolayer MoS2 anchored on CsPbBr3 perovskite quantum dots at room temperature via charge transfer is presented. The amount of electrons significantly transferred from perovskite gives rise to the large plasma screening in MoS2. The bandgap in heterostructure is red‐shifted by 84 meV with minimal pump fluence, the highest BGR in monolayer MoS2 at room temperature, which saturates with a further increase of pump fluence. Further, it is found that the magnitude of BGR inversely relates to Thomas–Fermi screening length. This provides plenty of room to explore the BGR within existing vast libraries of large bandgap van der Waals heterostructure toward practical devices such as solar cells, photodetectors, and light‐emitting‐diodes.
Ion Transport of Biohybrid Asymmetric Membranes by pH and Light‐Cooperative Modulation
Authors: Lv Yujia , Yang Nannan , Lu Shanfu , Xiang Yan
Published: September 2020

Bacteriorhodopsin (bR) is an excellent light‐driven proton pump and plays a vital role in chemical and biological analytical processes, such as maintaining osmotic balance, intracellular acidity, and participating in photosynthesis. Inspired by the special membrane structure with 75% bR and 25% lipid forming a purple membrane (PM) embedded on the Halobacterium salinarum cell membrane, an asymmetric membrane is fabricated by covering an anodic aluminum oxide (AAO) with a mixture of PM and poly(vinyl alcohol) (PVA) and ion transport modulation is achieved via coordination of pH and light stimuli. The rectification ratio of the PM‐doped asymmetric membrane is increased from 2 to 14.43 under costimulation of pH and light. Because bR is a conventional proton pump, the mechanism of this device may shed light on the design of other ionic asymmetric membranes (e.g., Na+, Cl−) via homologs of bR.
The Nuclear Orphan Receptor NR2F6 Promotes Hepatic Steatosis through Upregulation of Fatty Acid Transporter CD36
Authors: Zhou Bing , Jia Lijing , Zhang Zhijian , Xiang Liping , Yuan Youwen , Zheng Peilin , Liu Bin , Ren Xingxing , Bian Hua , Xie Liwei , Li Yao , Lu Jieli , Zhang Huijie , Lu Yan
Published: September 2020

Nuclear receptors (NRs) are a superfamily of transcription factors which sense hormonal signals or nutrients to regulate various biological events, including development, reproduction, and metabolism. Here, this study identifies nuclear receptor subfamily 2, group F, member 6 (NR2F6), as an important regulator of hepatic triglyceride (TG) homeostasis and causal factor in the development of non‐alcoholic fatty liver disease (NAFLD). Adeno‐associated virus (AAV)‐mediated overexpression of NR2F6 in the liver promotes TG accumulation in lean mice, while hepatic‐specific suppression of NR2F6 improves obesity‐associated hepatosteatosis, insulin resistance, and methionine and choline‐deficient (MCD) diet‐induced non‐alcoholic steatohepatitis (NASH). Mechanistically, the fatty acid translocase CD36 is identified as a transcriptional target of NR2F6 to mediate its steatotic role. NR2F6 is able to bind directly onto the CD36 promoter region in hepatocytes and increases the enrichment of nuclear receptor coactivator 1 (SRC‐1) and histone acetylation at its promoter. Of pathophysiological significance, NR2F6 is significantly upregulated in the livers of obese mice and NAFLD patients. Moreover, treatment with metformin decreases NR2F6 expression in obese mice, resulting in suppression of CD36 and reduced hepatic TG contents. Therefore, these results provide evidence for an unpredicted role of NR2F6 that contributes to liver steatosis and suggest that NR2F6 antagonists may present a therapeutic strategy for reversing or treating NAFLD/NASH pathogenesis.
Neurocognitive, adaptive, and psychosocial functioning in individuals with Robinow syndrome
Authors: Schwartz David D. , Fein Rachel H. , Carvalho Claudia M. B. , Sutton V. Reid , Mazzeu Juliana F. , Axelrad Marni E.
Published: September 2020

It has been estimated that 10–15% of people with Robinow syndrome (RS) show delayed development, but no studies have formally assessed developmental domains. The objective of this study is to provide the first description of cognitive, adaptive, and psychological functioning in RS. Thirteen participants (10 males) aged 4–51 years were seen for neuropsychological screening. Eight had autosomal‐dominant RS (DVL1, n = 5; WNT5A, n = 3), four had autosomal‐recessive RS (NXN, n = 2; ROR2, n = 2), and one had a mutation on an RS candidate gene (GPC4). Participants completed measures of intellectual, fine‐motor, adaptive, executive, and psychological functioning. Findings indicated generally average intellectual functioning and low‐average visuomotor skills. Adaptive functioning was average in autosomal‐recessive RS (RRS) but low average in autosomal‐dominant RS (DRS). Parent‐report indicated executive dysfunction and attention problems in 4/8 children, 3/4 of whom had a DVL1 variant; adult self‐report did not indicate similar difficulties. Learning disabilities were also reported in 4/8 individuals with DRS, 3/4 of whom had a DVL1 variant. Peer problems were reported for a majority of participants, many of whom also reported emotional concerns. Altogether, the findings indicate average neurocognitive functioning in RRS. In contrast, DRS, especially DVL1 pathogenic alleles, may confer specific risk for neurodevelopmental disability.
Congenital diaphragmatic hernia as a prominent feature of a SPECC1L‐related syndrome
Authors: Wild K. Taylor , Gordon Tia , Bhoj Elizabeth J. , Du Haowei , Jhangiani Shalini N. , Posey Jennifer E. , Lupski James R. , Scott Daryl A. , Zackai Elaine H.
Published: September 2020

Congenital diaphragmatic hernias (CDH) confer substantial morbidity and mortality. Genetic defects, including chromosomal anomalies, copy number variants, and sequence variants are identified in ~30% of patients with CDH. A genetic etiology is not yet found in 70% of patients, however there is a growing number of genetic syndromes and single gene disorders associated with CDH. While there have been two reported individuals with X‐linked Opitz G/BBB syndrome with MID1 mutations who have CDH as an associated feature, CDH appears to be a much more prominent feature of a SPECC1L‐related autosomal dominant Opitz G/BBB syndrome. Features unique to autosomal dominant Opitz G/BBB syndrome include branchial fistulae, omphalocele, and a bicornuate uterus. Here we present one new individual and five previously reported individuals with CDH found to have SPECC1L mutations. These cases provide strong evidence that SPECC1L is a bona fide CDH gene. We conclude that a SPECC1L‐related Opitz G/BBB syndrome should be considered in any patient with CDH who has additional features of hypertelorism, a prominent forehead, a broad nasal bridge, anteverted nares, cleft lip/palate, branchial fistulae, omphalocele, and/or bicornuate uterus.
Obtaining Protoanemonin through Selective Oxidation of D‐Fructose and 5‐(Hydroxymethyl)furfural in a Self‐catalysed Reaction
Authors: Martínez José J. , Páez Luis A. , Gutiérrez Luisa F. , Pardo Cuervo Oscar H. , Rojas Hugo A. , Romanelli Gustavo P. , Portilla Jaime , Castillo Juan‐Carlos , Becerra Diana
Published: September 2020

Although different ways of converting 5‐(hydroxymethyl)furfural (1) to various substrates with high value have been sought, few transformations have obtained building blocks that can be very useful in the area of fine chemistry. Herein, we report the synthesis of protoanemonin (5‐methylenefuran‐2(5H)‐one) from D‐fructose via compound (1), a versatile γ‐alkylidenebutenolide, using an efficient self‐catalysed process with formic acid, with high reaction performance and selectivity (up to 94% yield and 98% conversion from (1), while 28% yield from D‐fructose). This efficient and simple operational process involved a two‐phase aqueous‐organic system between chlorinated solvents (CHxCly) and hydrogen peroxide as the initial oxidizing agent. The reaction presents a key cleavage in the 5‐hydroxymethyl moiety of (1), due to the Baeyer‐Villiger oxidation (BVO) process that generates formic acid in situ. Ultimately, DFF and HMF were successfully obtained in 80% and 98% yield, respectively, starting from D‐fructose and using Preyssler heteropolyacids as Brønsted acid catalysts under an atmosphere of oxygen in the absence of hydrogen peroxide.
Life history and socioecology of infancy
Authors: Helfrecht Courtney , Roulette Jennifer W. , Lane Avery , Sintayehu Birhanu , Meehan Courtney L.
Published: September 2020

Objectives

Evolution of human maternal investment strategies is hypothesized to be tied to biological constraints and environmental cues. It is likely, however, that the socioecological context in which mothers' decisions are made is equally important. Yet, a lack of studies examining maternal investment from a cross‐cultural, holistic approach has hindered our ability to investigate the evolution of maternal investment strategies. Here, we take a systems‐level approach to study how human life history characteristics, environments, and socioecology influence maternal investment in their children.

Materials and methods

We test how infant age and sex, maternal age, parity, and child loss, and the composition of a child's cooperative breeding network are associated with maternal investment across three small‐scale (hunter‐gatherer, horticultural, and agropastoral), sub‐Saharan populations (N= 212). Naturalistic behavioral observations also enable us to illustrate the breadth and depth of the human cooperative breeding system.

Results

Results indicate that infant age, maternal age and parity, and an infant's cooperative childcare network are significantly associated with maternal investment, controlling for population. We also find that human allomaternal care is conducted by a range of caregivers, occupying different relational, sex, and age categories. Moreover, investment by allomothers is widely distributed.

Discussion

Our findings illustrate the social context in which children are reared in contemporary small‐scale populations, and in which they were likely reared throughout our evolutionary history. The diversity of the caregiving network, coupled with life history characteristics, is predictive of maternal investment strategies, demonstrating the importance of cooperation in the evolution of human ontogeny.
Conversion of spent coffee grounds to biochar as promising TiO2 support for effective degradation of diclofenac in water
Authors: Lazarotto Joseane Sarmento , de Lima Brombilla Vitória , Silvestri Siara , Foletto Edson Luiz
Published: September 2020

A novel composite, biochar derived from spent coffee grounds with immobilized TiO2 (biochar–TiO2) was prepared, characterized, and applied as an alternative, effective, and sustainable photocatalyst for degrading diclofenac from aqueous solution. Composites with different mass ratios between TiO2 and biochar were prepared by mechanical mixing and subsequent pyrolysis in an inert atmosphere of N2 at 650°C. The sample with biochar–TiO2 ratio of 1:1 presented a degradation efficiency of 90% at just 120 min versus 40% for TiO2 used as reference. This fact is associated with a set of intrinsic characteristics obtained during the formation of the composite, such as superior pore size, avoiding the recombination of the ē/h+ pair, bandgap reduction, and promotion of reactive oxygen species due to phenolic groups present on the biochar surface. The dominant reactive species involved during the photocatalytic degradation of diclofenac were h+ and •OH. The diclofenac degradation pathways were determined based on the identification of intermediates and nonpurgeable organic carbon (NPOC) analysis. The novel biochar–TiO2 composite prepared in this work showed high physical–chemical stability and efficiency over five consecutive cycles of reuse, proving to be a highly promising photocatalyst for degrading diclofenac in water.
Dechlorination of 2,4‐dichlorophenoxyacetic acid using biochar‐supported nano‐palladium/iron: Preparation, characterization, and influencing factors
Authors: Zhou Hongyi , Huang Ning , Zhao Yongkang , Baig Shams Ali , Xiang Junchao
Published: September 2020

In the present study, peanut shell, a green waste raw material, was used to prepare biochar (BC) and to obtain BC‐supported nano‐palladium/iron (BC‐nPd/Fe) composites for removing 2,4‐dichlorophenoxyacetic acid (2,4‐D) from water. Characterization analysis demonstrated that nPd/Fe particles were well dispersed on the BC surface with weakened magnetic properties. The average particle diameter and specific surface area of nPd/Fe were 101.3 nm and 6.7 m2 g−1, whereas the corresponding values of the BC‐nPd/Fe materials were 88.8 nm and 14.8 m2 g−1, respectively. Several factors were found to influence the dechlorination of 2,4‐D, including the weight ratio of BC to Fe, Pd loading ratio, initial solution pH, 2,4‐D concentration, and reaction temperature. Dechlorination results indicated that the 2,4‐D removal and phenoxyacetic acid (PA) generation rates were 44.1% and 20.1%, respectively, in the nPd/Fe system, and 100.0% and 92.1%, respectively, in the BC‐nPd/Fe system. The dechlorination of 2,4‐D was well described by the pseudo‐first‐order kinetic model (R2 > 0.97), and the observed rate constants kobs were 0.0042 min (nPd/Fe) and 0.0578 min (BC‐nPd/Fe), respectively. The reaction mechanism indicated that the dechlorination hydrogenation was the main process to remove 2,4‐D from water in the BC‐nPd/Fe system. In addition, BC inhibited the formation of a passivation layer on the particle surface during the reaction, thus maintaining the high reactivity of BC‐nPd/Fe. The easy preparation technique, high 2,4‐D dechlorination capacity, and mild reaction conditions suggest that BC‐nPd/Fe may be a promising alternative composite to remove 2,4‐D from water.
Comparison of liquid‐phase and methanol‐swelling crosslinking processes of polyimide dense membrane forCO2/CH4separation
Authors: Kim Seong‐Joong , Ahn Yeojin , Kim Jeong F. , Nam Seung‐Eun , Park Hosik , Cho Young Hoon , Baek Kyung‐youl , Park You‐In
Published: September 2020

To overcome the plasticization effect in polyimide membranes, many researchers have proposed crosslinking method. This can reduce an inter‐segmental mobility by tightening and rigidifying the polymer chains. However, it is difficult to modify the whole polymer chains throughout the membrane because the reaction can be hindered by the diffusion rate of the crosslinker. In particular, it is hard for bulky crosslinker to penetrate a dense membrane with a small d‐spacing. This study investigated the effect of crosslinking a dense Matrimid membrane withp‐phenylenediamine (p‐PDA) via two different crosslinking methods (i.e., methanol‐swelling crosslinking process [M‐SCP] and liquid‐phase crosslinking process [L‐PCP]). Most of the crosslinking reaction in M‐SCP occurs on the membrane surface due to difficulty in penetration of the bulkyp‐PDA into the Matrimid dense membrane. In contrast, the L‐PCP allows uniform crosslinking across the membrane. The membranes crosslinked using L‐PCP showed excellent chemical resistance. Furthermore, the plasticization phenomenon was not observed in the membranes crosslinked using L‐PCP withp‐PDA more than 15%. Meanwhile, the membrane crosslinked using M‐SCP exhibited poor plasticization and chemical resistance properties. These results showed that the L‐PCP method can be more effective for the crosslinking of dense membrane to deliver both high plasticization and chemical resistance.
Preparation and mechanism of free‐radical/cationic hybrid photosensitive resin with high tensile strength for three‐dimensional printing applications
Authors: Yang Zijun , Shan Junyang , Huang Yuchen , Dong Xianming , Zheng Wenxu , Jin Yifei , Zhou Wuyi
Published: September 2020

A ultraviolet (UV)‐curing free‐radical/cationic hybrid resin is designed and developed by blending epoxy resin with an acrylic resin, including N‐acryloyl morpholine, polyurethane acrylic ester (PUA), free‐radical and cationic photoinitiator. During UV‐curing, crosslinking locks the acrylate and epoxide polymers together through non‐covalent interaction. Most likely, the interpenetrating polymer network (IPN) structure can be generated in the three‐dimensional (3D)‐printed objects. The obtained results from Fourier transform infrared spectroscopy (FT‐IR) show that bisphenol A epoxy resin and acrylic resin are both successfully involved in the UV‐curing process. In addition, the effects of the mass ratio of epoxy to acrylic resin and the UV irradiation time on the properties of the hybrid resin are systematically investigated using liquid crystal display (LCD) 3D printers. It is found that the tensile strength of the hybrid resin increases in a certain range and the elongation at the break maintains an upward trend with the increasing mass ratio. Finally, it is found that the shrinkage of the hybrid resin also depends on the mass ratio of epoxy to acrylic resin, which decreases with the increase of the epoxy resin content in a certain range. Thus, herein we propose a feasible UV‐curing mechanism for the synthesis of hybrid resins for 3D printing applications.
Relationship between the residual and total strain from creep‐recovery tests of polypropylene/multiwall carbon nanotube composites
Authors: Starkova Olesja , Aniskevich Klara , Sevcenko Jevgenijs , Bulderberga Olga , Aniskevich Andrey
Published: September 2020

An assessment of accumulated irreversible strains in polymer composites is a crucial element for controlling dimensional stability of structural components and their remnant life. The residual strains as functions of total creep strains are analyzed by example of creep‐recovery data of polypropylene (PP)/multiwall carbon nanotube (MWCNT) composites. To cover wide range of strains, creep test regimes with different stresses, loading time, and number of cycles were applied. Totally, data of 62 single creep‐recovery tests for 7 material compositions were used for analysis. A general empirical relationship between the residual and total creep strain is established and finely described by a power law. The residual strain increases with increasing stress and time of loading and decreases with growing amount of MWCNT. The total creep strain, which is implicitly related to stress, time, and sample specificity, determines the contribution of irreversible deformation. This fact overcomes data variability within one series of samples. Similar empirical relationships are obtained for 25 polymer composites from literature reinforced with different types and amount of fillers and tested under different temperatures. The empirical relationship can be used for an express assessment of residual strains accumulated in a long term by performing just a few short‐term control tests.
Microwave‐assisted rapid fabrication of robust polyetherimide bead foam parts
Authors: Feng Dong , Liu Pengju
Published: September 2020

Polyetherimide (PEI) is an important candidate for fabrication of high‐performance polymer foams. Nevertheless, the manufacture of PEI foamed parts with specific three‐dimensional geometry shape and lightweight properties remains a big challenge worldwide. Herein, a microwave (MW)‐assisted foaming and selective sintering approach was proposed towards rapid fabrication of robust PEI bead foams. During the process, compressed carbon dioxide/tetrahydrofuran was used as physical co‐foaming agent, and the surface‐coated graphene nanoplatelets (GNPs) was used as MW absorbent. Upon MW irradiation, the GNPs selectively heated and served as solders that effectively facilitated the foaming of expandable PEI (EPEI) beads, and strongly promoted the local polymer melt and entanglement across the surface of EPEI beads. The MW irradiation power and time were considered as the important parameters to achieve fine inter‐bead bonding strength between foamed beads. As a model system, we successfully fabricated a 25‐mm‐thickness foamed part with an apparent density of 0.32 g/cm3and achieved excellent inter‐bead bonding performance. Specifically, we also utilized the COMSOL Multiphysics simulations to study the MW selective heating mechanism. This MW‐assisted fabrication strategy offers a new foaming approach toward high‐performance polymer foamed parts for many advanced applications.
Achieving Purely‐Organic Room‐Temperature Aqueous Phosphorescence via a Two‐Component Macromolecular Self‐Assembly Strategy
Authors: Guo Wang , Wang Xuepu , Zhou Bei , Zhang Kaka
Published: September 2020

Manipulation of supramolecular behaviors and aggregation states represents an important topic in devising intriguing photofunctional systems. Here we report a two‐component macromolecular self‐assembly strategy for achieving aqueous room‐temperature phosphorescence (RTP) in purely organic systems. Amphiphilic triblock copolymers are used to modulate the self‐assembly of planar RTP molecules in aqueous solution, leading to the formation of sheet‐like RTP objects with well‐defined morphology, uniform crystalline nanostructures and excellent aqueous dispersity. In contrast, the addition of the planar RTP molecules into aqueous medium only leads to precipitation and quenching of RTP properties. Powder X‐ray diffraction and single‐crystal X‐ray diffraction studies reveal that the amphiphilic triblock copolymers can assist supramolecular columnar packing of the planar RTP molecules where multiple non‐covalent interactions stabilize the triplet excited states. Interestingly, it is found that luminescent signals of the sheet‐like RTP objects can be extracted from strong fluorescent environments by phosphorescence mode and emission lifetime measurement.
On‐surface Synthesis of a Chiral Graphene Nanoribbon with Mixed Edge Structure
Authors: Keerthi Ashok , Sánchez‐Sánchez Carlos , Deniz Okan , Ruffieux Pascal , Schollmeyer Dieter , Feng Xinliang , Narita Akimitsu , Fasel Roman , Müllen Klaus
Published: September 2020

Chiral graphene nanoribbons represent an important class of graphene nanomaterials with varying combinations of armchair and zigzag edges conferring them unique structure‐dependent electronic properties. Here, we describe the on‐surface synthesis of an unprecedented cove‐edge chiral GNR with a benzo‐fused backbone on a Au(111) surface using 2,6‐dibromo‐1,5‐diphenylnaphthalene as precursor. The initial precursor self‐assembly and the formation of the chiral GNRs upon annealing are revealed, along with a relatively small electronic bandgap of approximately 1.6 eV, by scanning tunnelling microscopy and spectroscopy.
Heteroatom Doping Strategy for Establishing Hematite Homojunction as Efficient Photocatalyst for Accelerating Water Splitting
Authors: Tao Shang‐Mao , Chung Ren‐Jei , Lin Lu‐Yin
Published: September 2020

Hematite (α‐Fe2O3) is one of the promising photocatalysts for water oxidation, owing to its stable, abundant and visible‐light responsive features. Enhancing electrical conductivity and accelerating oxidation evolution kinetics are expected to improve photocatalytic ability of hematite toward water oxidation. In this work, strategies of doping heteroatoms and developing pn homojunction are adopted to enhance the photocatalytic ability of hematite electrodes. The Ti and Mg dopants are separately incorporated in two layers of hematite electrodes via two‐step hydrothermal reaction and one‐step annealing process. The effect of regrowth time for synthesizing Mg‐doped hematite on the photoelectrochemical performance of Mg‐doped and Ti‐doped hematite (Mg−Fe2O3/Ti−Fe2O3) electrode is studied. The size of rod‐like structure and gaps in‐between play important roles on the photocatalytic ability of Mg−Fe2O3/Ti−Fe2O3. The optimized Mg−Fe2O3/Ti−Fe2O3 electrode is prepared by using merely 10 min for synthesizing the Mg‐doped hematite top layer, which shows the highest photocurrent density of 2.83 mA/cm2 at 1.60 VRHE along with the highest carrier density of 5.89×1016 cm−3 and the smallest charge‐transfer resistance. This largely improved photoelectrochemical performance is attributed to the more donor generation with heteroatom‐doping and more efficient charge cascade with homojunction establishment. Other p‐type metals are encouraged to dope in hematite as the second layer to couple with the n‐type Ti‐doped hematite for developing efficient pn homojunction and improve the photocatalytic ability of hematite in the near future.
Recent Advances in Oxide‐based Nonlinear Optical Materials with Wide Infrared Transparency Beyond 6 μm
Authors: Chen Xinglong , Ok Kang Min
Published: September 2020

Nonlinear optical (NLO) materials are indispensable for laser frequency conversion, by which the output wavelength of laser can be greatly expanded. A prerequisite for the applications of NLO materials is that they must be optically transparent in the working spectral range. Although the widely used infrared (IR) NLO crystals such as AgGaS2, AgGaSe2, and ZnGeP2 have very broad mid‐IR (2–20 μm) transparency, they are all inherently suffered by low laser‐induced damage thresholds (LDTs). Oxide‐based materials usually possess desirably high LDTs, however, most of them have quite limited IR transparency, typically, within 6 μm. In this Minireview, we focus on new oxide‐based NLO materials showing exceptionally wide IR transparent ranges beyond 6 μm, in which significant developments have been achieved in recent years. Nine relevant NLO materials are investigated and analyzed from the aspects of design strategy, synthesis and large crystal growth, optical and NLO properties as well as composition‐structure‐property correlations. A brief perspective on the future research directions is also provided.
On the new operational characteristic for degrading systems executing missions of fixed duration
Authors: Finkelstein Maxim , Levitin Gregory
Published: September 2020

In practice, it is often important to know how a system is performing as compared with initial, prior assessment of its reliability characteristics (black‐box scenario). For degrading systems, this comparison can be executed by observing degradation dynamically and then comparing the corresponding remaining lifetime of an operating system at each instant of time with that of the black‐box scenario. As a motivating example, the 1 out of n cold standby system is considered. Then the results of comparisons are generalized to the case of the general monotone stochastic processes of deterioration. Finally, based on the developed reasoning, a problem of describing the quality of performance of systems executing missions of the fixed duration is considered for the cost‐wise and probability‐wise criteria. The detailed numerical examples for the homogeneous gamma process of deterioration are presented.
Color Tuning of Light Emitted from the Cathodoluminescence of (Ca1 − xEux)Ga2S4 Phosphors
Authors: Cho Young‐Sik , Park Hye‐Jin , Kim Eung‐Dab , Jang Min‐Kyeong , Huh Young‐Duk
Published: September 2020

(Ca1‐xEux)Ga2S4 (x = 0.10, 0.40, 0.70, 1.0) phosphors were synthesized from CaS, EuS, and Ga2S3 via a solid‐state reaction, and their crystal structures were investigated by X‐ray diffraction analysis. Cathodoluminescence (CL) spectra of these phosphors under moderate electron‐beam voltages from 4 to 10 kV were investigated to assess their applicability in carbon nanotube field‐emission displays. The wavelength at maximum intensity (λmax) of the CL spectra changed gradually from 557 to 546 nm with increasing europium‐ion mole fraction (x) in the (Ca1‐xEux)Ga2S4 phosphors. These bands were attributed to the transitions from the lowest energy level of the 4f65d1 excited state to the 4f7 (8S7/2) ground state of the Eu2+ ions. The blue shift of this wavelength was interpreted on the basis of the crystal structures of the phosphors. The color of light emitted from the (Ca1‐xEux)Ga2S4 phosphors was confirmed to be tunable.
UHPLC/GC‐TOF‐MS metabolomics, MTT assay, and molecular docking studies reveal physostigmine as a new anticancer agent from the ethyl acetate and butanol fractions ofKigelia africana(Lam.) Benth. fruit extracts
Authors: Fagbohun Oladapo F. , Olawoye Babatunde , Ademakinwa Adedeji N. , Oriyomi Olumayowa V. , Fagbohun Oladoyin S. , Fadare Olatomide A. , Msagati Titus A.M.
Published: September 2020

Kigelia africanaplant is widely used as a herbal remedy in preventing the onset and the treatment of cancer‐related infections. With the increase in the research interest of the plant, the specific chemical compound or metabolite that confers its anticancer properties has not been adequately investigated. The ethyl acetate and butanol fractions of the fruit extracts were evaluated by 2‐(4,5‐dimethylthiazol‐2‐yl)‐3,5‐diphenyl‐2H‐tetrazolium bromide assay against four different cell lines, with the ethyl acetate fraction having inhibition concentration values of 0.53 and 0.42 μM against Hep G2 and HeLa cells, respectively. More than 235 phytoconstituents were profiled using UHPLC‐TOF‐MS, while more than 15 chemical compounds were identified using GC–MS from the fractions. Molecular docking studies revealed that physostigmine, fluazifop, dexamethasone, sulfisomidine, and desmethylmirtazapine could favorably bind at higher binding energies of –8.3, –8.6, –8.2, and –8.1 kcal/mol, respectively, better than camptothecin with a binding energy of –7.9 kcal/mol. The results of this study showed that physostigmine interacted well with topoisomerase IIα and had a high score of pharmacokinetic prediction using absorption, distribution, metabolism, excretion, and toxicity profiles, thereby suggesting that drug design using physostigmine as a base structure could serve as an alternative against the toxic side effects of doxorubicin and camptothecin.