bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptive Switching Hybrid Blast-STBC MIMO System
Authors: Salemdeeb Mohammed , Abu-Hudrouss Ammar
Published: July 2021

Fading in a wireless channel has negative effects on the performance of communication systems. Bell Laboratories layered space-time (BLAST) has been used to get a high data rate while space-time block codes (STBC) have been used to get a low bit error rate (BER) performance. Under deep faded channels, hybrid BLAST-STBC systems are considered as a trade-off between BLAST and STBC systems. By exploiting the benefits of both systems, a new method to represent a 4 × 4 multiple-input and multiple-output (MIMO) system is proposed and studied, in which the transmission process is carried out adaptively between both 4 × 4 VBLAST, Quasi-Orthogonal STBC (QOSTBC) and Hybrid systems according to the transmit links state. The proposed adaptive switching hybrid system (ASHS) reduces the total transmitted power, achieves the maximum throughput by obtaining the best BER. An adaptive switching transmission scheme using the strategy of measuring the transmit links fading is investigated as well. The simulated results are obtained in an environment of a 4 × 4 MIMO system using MATLAB platform where the total transmitting power is normalized to unity. The detections are done using the maximum likelihood (ML) receiver. The proposed ASHS system shows a lot of advantages such as maximum throughput is obtained in bad channel states, no additional transmit power is needed and no additional bandwidth is needed. Finally, under deep fading condition, the proposed ASHS transmission scheme obtains the best BER, reduces wasting the total transmitted power, achieves the maximum throughput and obtains the best BER.
Equity‐focused online facilitation for adult learners
Authors: Alston Geleana D. , Hansman Catherine A. , Freeman Steven
Published: July 2021

This article describes equity‐focused online facilitation. Online approaches for fostering equity and strategies for inclusive practices are explained.
Facilitative communication mediated by technology
Authors: Yelich Biniecki Susan M.
Published: July 2021

Facilitating discussions is an integral part of virtual, synchronous and asynchronous adult and higher education settings. This article offers effective strategies for supporting learners and guiding discussion, particularly about social and critical content.
A Novel Approach to Robustly Determine Residual Stress in Additively Manufactured Microstructures Using Synchrotron Radiation
Authors: Aminforoughi Behzad , Degener Sebastian , Richter Julia , Liehr Alexander , Niendorf Thomas
Published: July 2021

In recent decades additive manufacturing (AM) for years has been in focus of academia and industry as its underlying production principle allows for the realization of designs of unprecedented geometrical complexity. However, often such structures are not realized due to the lack of understanding of structural and mechanical properties, this fact amongst others related to the unique microstructures established by the related processes. In this context, residual stresses, highly affected by the scan strategy and process parameters used, play an essential role. Generally, various methods and approaches can be used to determine residual stress states experimentally. However, especially in case of the unique microstructures formed by AM, most standard procedures cannot be applied reliably. Commonly used methods based on X‐ray diffraction rely on laboratory X‐ray sources and synchrotron radiation. In present work, a novel method is proposed for robustly calculating residual stresses based on the linear regression method (similar to the sin2
ψ approach in reflection mode). Data obtained by use of synchrotron radiation in transmission mode are applied. To assess the reliability of the novel procedure, results are validated using simulations and in situ tensile tests. For these tests the well‐known Ni‐base alloy INCONEL 718 processed by laser powder bed fusion (LPBF), being characterized by a complex microstructure, and a conventionally manufactured 100Cr6 steel sample are used.
Textronics—A Review of Textile‐Based Wearable Electronics
Authors: Choudhry Nauman A. , Arnold Lyndon , Rasheed Abher , Khan Imtiaz A. , Wang Lijing
Published: July 2021

Textronics contribute a significant part of Internet‐of‐Things (IoT), which empowers added functionalities by connecting smart clothing in a secure way for diverse applications. For the development of flexible and stretchable textile‐based electronics, a conductive material (yarn, fabric, etc.) must be used, and fabrication techniques play a vital role that significantly influences electronic textiles’ properties. Textile‐based sensors, electrodes, and other devices seem to be the favorite choice for continuous wearable monitoring due to their low cost, flexibility, and ease of embedding. Integrating smart capabilities into textiles provides substantial benefits in the fields of healthcare, sports, automobile, and military. These developments have a profound influence on the Fourth Industrial Revolution (4IR). This Review presents an in‐depth study of the current state of the art in the area of textile‐based electronics. The design, development, and evaluation techniques are discussed. Certain limitations and research gaps are also addressed regarding this emerging field. Critically, this Review is more application focused and indicates how the recent developments in electronic textiles will soon impact our lives. As these areas have typically been neglected in previous reviews, additional knowledge to the existing literature is provided by bridging the gap between the academic research and commercialization of wearable Textronics.
Laser‐Induced Graphene Assisting Self‐Conversion Reaction for Sulfur‐Free Aqueous Cu‐S Battery
Authors: Yang Zhengwei , Xu Chiwei , Yan Huihui , Liu Yiwen , Yue Chuang , Zhang Liyuan , Shui Miao , Hu Fang , Shu Jie
Published: July 2021

In aqueous/nonaqueous metal‐sulfur batteries, sulfur‐based redox couple exhibits significant challenges mainly due to its low electrochemical kinetics, potential shuttle effect, and large volume change. Although massive researches have been conducted to optimize or replace metal anode and cathode composite, major challenges caused by the dependency on sulfur‐based redox couple still remain. In this study, a novel redox couple of CuS/Cu2S, which provides the same theoretical capacity (based on conventional S/S2− redox couple) by changing the valence of ion charge carrier, is proposed. For achieving high reversibility, commercially viable laser‐induced graphene (LIG) is fabricated and used for the first time in aqueous metal‐sulfur batteries. By virtue of the synergism between novel redox couple and LIG, aqueous CuS/Cu2S battery delivers a highly reversible capacity of 1654.9 mAh g−1 in the initial cycle and retains 91.2% with 1509.5 mAh g−1 after 328 cycles. When being cycled at 2.8 A g−1, its reversible capacity still retains 92.1% after 410 cycles. This study provides a new choice by using a sulfur‐free redox couple from screening thermodynamic parameters and analyzes the functional mechanism of LIG by density functional theory, aiming to innovate the energy storage mechanism of aqueous metal‐sulfur batteries.
3D Transformable Modular Kirigami Based Programmable Metamaterials
Authors: Li Yanbin , Zhang Qiuting , Hong Yaoye , Yin Jie
Published: July 2021

Kirigami, the ancient paper art of cutting, has recently emerged as a new approach to construct metamaterials with novel properties imparted by cuts. However, most studies are limited to thin sheets‐based 2D kirigami metamaterials with specific forms and limited reconfigurability due to planar connection constraints of cut units. Here, 3D modular kirigami is introduced by cutting bulk materials into spatially closed‐loop connected cut cubes to construct a new class of 3D kirigami metamaterials. The module is transformable with multiple degrees of freedom that can transform into versatile distinct daughter building blocks. Their conformable assembly creates a wealth of reconfigurable and disassemblable metamaterials with diverse structures and unique properties, including reconfigurable 1D column‐like materials, 2D lattice‐like metamaterials with phase transition of chirality, as well as 3D frustration‐free multilayered metamaterials with 3D auxetic behaviors and programmable deformation modes. This study largely expands the design space of kirigami metamaterials from 2D to 3D.
Spin‐Orbit Torque in Van der Waals‐Layered Materials and Heterostructures
Authors: Tang Wei , Liu Haoliang , Li Zhe , Pan Anlian , Zeng Yu‐Jia
Published: July 2021

Spin‐orbit torque (SOT) opens an efficient and versatile avenue for the electrical manipulation of magnetization in spintronic devices. The enhancement of SOT efficiency and reduction of power consumption are key points for the implementation of high‐performance SOT devices, which strongly rely on the spin‐orbit coupling (SOC) strength and magnetic properties of ferromagnetic/non‐magnetic heterostructures. Recently, van der Waals‐layered materials have shown appealing properties for use in efficient SOT applications. On the one hand, transition‐metal dichalcogenides, topological insulators, and graphene‐based heterostructures possess appreciable SOC strength. This feature can efficiently converse the charge current into spin current and result in large SOT. On the other hand, the newly discovered layered magnetic materials provide ultra‐thin and gate‐tunable ferromagnetic candidates for high‐performance SOT devices. In this review, the latest advancements of SOT research in various layered materials are summarized. First, a brief introduction of SOT is given. Second, SOT studies of various layered materials and heterostructures are summarized. Subsequently, progresses on SOT‐induced magnetization switching are presented. Finally, current challenges and prospects for future development are suggested.
Mechanisms behind pH changes during electrocoagulation
Authors: Weiss Søren Fredberg , Christensen Morten Lykkegaard , Jørgensen Mads Koustrup
Published: July 2021

Electrocoagulation is a promising method for removing pollutants from surface water and industrial wastewater. The coagulation efficiency is dependent on pH but it is not fully understood how electrocoagulation affects pH of the treated water. Three series of experiments have been conducted to study how (1) chloride and sulfate anions, (2) negatively charged organic macromolecules, and (3) carbonate influence pH during electrocoagulation. It is found that dissolved carbonate has a significant influence on the pH change as CO2 is stripped off during electrocoagulation due to formation of H2 microbubbles at the cathode. The pH increased by 1 pH unit, which may significantly affect coagulation efficiency of iron. The pH increase depended strongly on the initial pH and the concentration of carbonate in the water. A secondary contribution to pH change was found to be ion exchange by sulfate and chloride ions into Fe(OH)3 flocs, whereby OH− was released into solution but only minor pH change was observed, not enough to affect the coagulation. The presence of charged organic macromolecules did not have any significant effect on pH.
The modulation of ethane‐selective adsorption performance in series of bimetal PCN‐250 metal–organic frameworks: Impact of metal composition
Authors: Wu Houxiao , Chen Yongwei , Yuan Yinuo , Lv Daofei , Tu Shi , Liu Zewei , Li Zhong , Xia Qibin
Published: July 2021

The developments of high‐performance adsorbents have attracted ever‐increasing attention in the separation of ethane/ethylene (C2H6/C2H4) mixtures. In this work, a series of ultra‐stable C2H6‐selective metal–organic frameworks (MOFs), PCN‐250, and its bimetal version PCN‐250(Fe2M2+, M2+ = Ni2+, Co2+, Zn2+, Mn2+), were synthesized to investigate the influence of metal compositions on the C2H6‐selective performance. Among the five materials, at 298 K and 100 kPa, PCN‐250(Fe2Co) showed the largest C2H6 uptake (6.21 mmol/g) while PCN‐250(Fe2Zn) exhibited the highest C2H6/C2H4 ideal adsorption solution theory (IAST) selectivity (1.70). The molecular simulation revealed that the introduced metal ions have different influences on the atomic partial charge within the framework which varied the framework adsorption affinities toward C2H6/C2H4 molecules. Moreover, the research on PCN‐250(Fe2Zn) suggested that the increased positive partial charge of metal sites together with a decreased charge density of benzene ring (BR) sites from the organic ligands will be beneficial to improve the desired C2H6 selectivity.
ThermosensitivePMMAcore/oligo(ethylene glycol)‐based shell microgels as drug carriers in detoxification treatment
Authors: Meng Yuting , Shen Jing , Fu Ting , Feng Xiyun , Wang Siping , Wang Tongwen , Zhang Xufeng
Published: July 2021

The core‐shell structured polymer microgels were synthesized by coating the hydrophobic poly(methyl methacrylate) (PMMA) sphere cores with hydrophilic nonlinear poly(ethylene glycol)‐based gel shell layer. The uniqueness of these core‐shell microgels lies in the integration of the PMMA core microsphere with strong hydrophobicity and the novel oligo(ethylene glycol)‐based gel layer with well‐defined thermosensitivity for improving loading/release efficacy of two detoxification drugs (chlorpromazine and diltiazem). The hydrophilic shell is composed of hydrophilic copolymer of 2‐(2‐methoxyethoxy)ethyl methacrylate (MEO2MA) with oligo(ethylene glycol) methyl ether methacrylates (MEO5MA). It was found that the molar ratio of two shell monomersn(MEO2MA)/n(MEO5MA) of 1:6 was an ideal matching value for production of the P(MEO2MA)/P(MEO2MA‐co‐MEO5MA) core‐shell microgels with tunable volume phase transition temperature and excellent colloidal stability across the physiologically important temperature range. Moreover, chlorpromazine‐ and diltiazem‐loaded microgels can show an obvious thermosensitive release and in vitro sustained‐release characteristic up to 80 h.
Vulcanization, static mechanical properties, and thermal stability of activated calcium silicate/styrene‐butadiene rubber composites prepared via a latex compounding method
Authors: Wang Weijiang , Zhang Yinmin , Zhang Yongfeng , Sun Junmin
Published: July 2021

Herein, we describe the latex compounding preparation of activated calcium silicate (ACS)/styrene‐butadiene rubber (SBR) composites aiming to improve filler dispersibility. The effects of ACS particle size and filler content on the vulcanization, static mechanical properties, and thermal stability of composite materials were evaluated. FT‐IR analyses showed that the rubber macromolecules were chemically adsorbed on the surface of the ACS particles, while SEM and TEM indicated that the ACS particles were uniformly distributed in the composites, and agglomeration occurred only at high filler content levels. ACS particle size reductions accelerated composite vulcanization, whereas increasing filler content had the opposite effect. ACS particles strengthened the mechanical properties of prepared composites, with marked increases in tensile strength and tear strength as ACS particle size decreased and filler content rose, reaching maximal values of 15.37 MPa (increased by 932%) and 45.91 kN/m (increased by 425%), respectively, at an ACS average particle size of 1 μm and 90 phr loading. ACS particle integration also enhanced composite thermal stability. These data indicate that ACS enhances rubber composites owing to the incorporation of well‐dispersed ACS particles into the rubber matrix, strong interactions between ACS particles and rubber molecules, and the thermal barrier effects of these particles.
High‐Temperature and Large‐Polarization Ferroelectric with Second Harmonic Generation Response in a Novel Crown Ether Clathrate
Authors: Han Ding Chong , Tan Yu Hui , Li Yu Kong , Wen Jia Hui , Tang Yun Zhi , Wei Wen Juan , Du Peng Kang , Zhang Hao
Published: July 2021

Molecular ferroelectrics of high‐temperature reversible phase transitions are very rare and have attracted increasing attention in recent years. In this paper is described the successful synthesis of a novel high‐temperature host‐guest inclusion ferroelectric: [(C6H5NF3)(18‐crown‐6)][BF4] (1) that shows a pair of reversible peaks at 348 K (heating) and 331 K (cooling) with a heat hysteresis about 17 K by differential scanning calorimetry measurements, thus indicating that 1 undergoes a reversible structural phase transition. Variable‐temperature PXRD and temperature‐dependent dielectric measurements further prove the phase‐transition behavior of 1. The second harmonic response demonstrates that 1 belongs to a non‐centrosymmetric space group at room temperature and is a good nonlinear optical material. In its semiconducting properties, 1 shows a wide optical band gap of about 4.43 eV that comes chiefly from the C, H and O atoms of the crystals. In particular, the ferroelectric measurements of 1 exhibit a typical polarization‐electric hysteresis loop with a large spontaneous polarization (Ps) of about 4.06 μC/cm2. This finding offers an alternative pathway for designing new ferroelectric‐dielectric and nonlinear optical materials and related physical properties in organic‐inorganic and other hybrid crystals.
Continuous Flow Synthesis of [Au(NHC)(Aryl)] (NHC=N‐Heterocyclic Carbene) Complexes
Authors: Cauwenbergh Thibault , Tzouras Nikolaos V. , Scattolin Thomas , Bhandary Subhrajyoti , Simoens Andreas , Van Hecke Kristof , Stevens Christian V. , Nolan Steven P.
Published: July 2021

The use of weak and inexpensive bases has recently opened promising perspectives towards the simpler and more sustainable synthesis of Au(I)‐aryl complexes with valuable applications in catalysis, medicinal chemistry, and materials science. In recent years, continuous manufacturing has shown to be a reliable partner in establishing sustainable and controlled process scalability. Herein, the first continuous flow synthesis of a range of Au(I)‐aryl starting from widely available boronic acids and various [Au(NHC)Cl] (NHC=N‐heterocyclic carbene) complexes in unprecedentedly short reaction times and high yields is reported. Successful synthesis of previously non‐ or poorly accessible complexes exposed fascinating reactivity patterns. Via a gram‐scale synthesis, convenient process scalability of the developed protocol was showcased.
Unveiling the Role of Hydrogen Bonds in Luminescent N‐Annulated Perylene Liquid Crystals
Authors: Bujosa Sergi , Greciano Elisa E. , Martínez Manuel A. , Sánchez Luis , Soberats Bartolome
Published: July 2021

We report the liquid‐crystalline (LC) and luminescent properties of a series of N‐annulated perylenes (1–4) in whose molecular structures amide and ester groups alternate. We found that the LC properties of these compounds not only depend on the number of hydrogen‐bonding units, but also on the relative position of the amide linkers in the molecule. The absence of amide groups in compound 1 leads to no LC properties, whereas four amide groups induce the formation of a wide temperature range columnar hexagonal phase in compound 4. Remarkably, compound 3, with two amide groups in the inner part of the structure, stabilizes the columnar LC phases better than its structural isomer 2, with the amide groups in the outer part of the molecule. Similarly, we found that only compounds 1 and 2, which have no hydrogen bonding units in the inner part of the molecule, exhibit luminescence vapochromism upon exposure to organic solvent vapors.
Life‐history responses of a freshwater rotifer to copper pollution
Authors: Schanz Federica R. , Sommer Stefan , Lami Andrea , Fontaneto Diego , Ozgul Arpat
Published: July 2021

In organisms with dormant stages, life‐history responses to past pollution can be studied retrospectively. Here, we study such responses in a rotifer (Brachionus calyciflorus) from the once heavily copper‐polluted Lake Orta (Italy). We extracted resting eggs from sediments, established clonal lineages from hatchlings, and exposed newborns of these lineages to one of three copper concentrations that each mimicked a specific period in the lake's pollution history. For each rotifer, we daily collected life‐table data. We then estimated treatment‐specific vital rates and used a stage‐structured population model to project population growth rate λ. We also estimated elasticities of λ to vital rates and contributions of vital rates to observed Δλ between copper treatments. As expected, λ decreased with increasing copper concentration. This decrease resulted mostly from a decline in juvenile survival rate (SJ) and partly from a decline in the survival rate of asexually reproducing females (SA). Maturation rate, and with one exception fecundity, also declined but did not contribute consistently to Δλ. λ was most elastic to SJ and SA, indicating that survival rates were under stronger selection than maturation rate and fecundity. Together, our results indicate that variation in juvenile survival is a key component in the rotifers’ copper response. The consistent decrease in SJ with increasing copper stress and the sensitivity of λ to that decrease also suggest that juvenile survival is a useful indicator of population performance under environmental pollution.
Spatio‐temporal heterogeneities in water quality and their potential drivers in Lake Chaohu (China) from 2001 to 2017
Authors: Zhang Lei , Fang Yong , Cai Hua , Zhang Siqing
Published: July 2021

Damage to the water ecosystems and the deterioration of lake water resources may negatively affect the surface water resources, particularly, which of the daily drinking water supply of residents. Therefore, it is particularly important to study the spatio‐temporal heterogeneity of water quality in large lakes. We analysed the data from six sampling sites in Lake Chaohu from 2001 to 2017 and eight sampling sites of the inflow rivers in 2001, 2009 and 2017. The six sampling sites were divided into SG I and SG II through cluster analysis, and the spatio‐temporal changes of the water quality in the Lake Chaohu Basin were studied. The results indicated the following: All nutrient variables had relatively high concentrations in SG II except DO, while SG I had relatively high concentrations of only TN. Besides, the value of Chl a in each group is generally high. On the temporal scale, the changes in the water quality of the lake showed strong seasonality; the nutrient variable (TN, TP, NH4‐N and CODMn) except DO in the inflow rivers is generally higher than that of the lake; the water quality of Lake Chaohu has improved during the study period, and it has also improved to a certain extent compared with that of the late 1980s. Fortunately, parts water quality parameters of Lake Chaohu have improved faster than that of the other four largest freshwater lakes in China. This research result has a certain guiding significance for the prevention and control of large lake water pollution.
Synthesis of 10H‐Indolo[1,2‐a]indole Derivatives via Intramolecular Cycloaddition and H‐Migration
Authors: Zhao Yulei , Li Shuai , Fan Yuhang , Guo Xuqiang , Jiao Xin , Tian Laijin , Sun Xuejun
Published: July 2021

A novel method for synthesizing 10H‐indolo[1,2‐a]indole derivatives is reported here. All products are prepared by applying the intramolecular cyclization strategy at room temperature. The reaction was realized through I2/ZnI2 catalyzed intramolecular nucleophilic addition, hydrogen migration, and rearrangement procedures. The electronic effect and steric hindrance have a significant influence on the reactivity. Moreover, the synthetic value of 10H‐indolo[1,2‐a]indole was also exemplified by the selective decarboxylation and aromatization.
Fracturing and production analysis of the efficacy of hydraulic fracture stage reduction in the improvement of cost‐effectiveness in shale oil development: A case study of Jimsar shale oil, China
Authors: Zhi Dongming , Guo Xuyang , Wang Wei , Jin Yan , Liu Caiguang , Chen Gang , Wang Zhenlin
Published: July 2021

The effective production of shale oil is important for the cost‐effectiveness in the oil and gas industry. Oil price volatility and uncertainty require suitable hydraulic fracturing schemes to maximize production and to minimize fracturing costs. Since the reduction of fracture stage saves bridge plugs and fracturing costs, it is considered as a possible method to improve the cost‐effectiveness. To maintain the stimulated reservoir volume, cluster numbers per stage are consequently increased, which may induce nonuniform fracture propagation and interference which affects the stimulation efficiency. This study conducts a comparative study for single‐stage (reduced) and two‐stage (not reduced) fracturing schemes with the same fracturing fluid volume. Reservoir geomechanics and rock mechanics analyses are conducted for Jimsar shale oil in north‐western China with a single‐stage multicluster fracturing model established. Fracture geometries and key factors are investigated followed by the evaluation of the fractured well production. The relationship between multicluster parameters and production is quantified. Meanwhile, two‐stage fracturing modeling is also set up to compare with single‐stage fracturing modeling. Fracturing results show that although single‐stage fracturing results in nonuniform fracture propagation, the overall stimulation is satisfactory. Production results show that the nonuniform growth of fracture clusters leads to different contributions to the production from individual clusters and the production from inner fractures is significantly inhibited. Compared with two‐stage fracturing with the same pumping volume, it is found out that single‐stage fracturing can lead to cost‐effective horizontal well production in Jimsar shale oil given certain values of hydraulic fracturing costs, and the reduced stage scheme is preferable in low oil price and high uncertainty scenarios.
Feeding containing the aerial part of Scutellaria baicalensis promotes the growth and nutritive value of rabbit fish Siganus fuscescens
Authors: Xia Yi‐Teng , Cheng Edwin Hok‐Chi , Zheng Brody Zhong‐Yu , Wu Qi‐Yun , Dong Tina Ting‐Xia , Duan Ran , Qin Qi‐Wei , Wang Wen‐Xiong , Tsim Karl Wah‐Keung
Published: July 2021

The root of Scutellaria baicalensis (Scutellaria Radix) has been used as herbal medicine for years, while its stem and leaf (aerial part) are considered as waste. The water extract from the aerial part of S. baicalensis (named as SBA) being included in the feeding of Siganus fuscescens (grey rabbit fish) has been shown to replace antibiotics in aquaculture with excellent outcome. To strengthen the usage of SBA in fish feeding, the total fish output and its nutritive value were determined here. Feeding the fishes with different doses of SBA for a month, the body length and weight were significantly increased after intake of standard feed containing 1% SBA. In parallel, the expressions of alkaline phosphatase and growth‐related factors in bone, liver, and muscle of 1% SBA‐fed fishes were markedly increased, suggesting the beneficial effects of SBA. The composition of amino acid and fatty acid in fish muscle, after intaking 1% SBA‐containing feed, was altered. In SBA‐fed fish muscle, the amounts of threonine and methionine were increased, while the amount of leucine was decreased, as compared with control group. The amounts of fatty acids, including docosahexaenoic acid, phosphatidylcholine, and phosphatidylethanolamine, were increased in the 1% SBA‐fed fish, while the amounts of triglycerides were decreased. The results indicated the growth‐promoting activity of SBA in an in vivo culture of S. fuscescens, as well as to increase the nutritive values of the muscle. Thus, the re‐cycle of waste products during the farming of S. baicalensis herb in serving as fish feeding should be encouraged.
The opportunity cost of hedging under incomplete information: Evidence from ETF/Ns
Authors: Cui Zhenyu , Simaan Majeed
Published: July 2021

This paper considers the optimal hedge ratio problem under estimation risk. Due to incomplete information, the decision‐maker evaluates the opportunity cost of hedging using exchange‐traded funds or notes (ETF/Ns). Using a backtesting procedure over the last 5 years and 13 different hedging instruments—both inverse‐equity ETFs and volatility ETNs—we quantify the proposed opportunity cost using different out‐of‐sample performance metrics. Given the greater accessibility of commission‐free brokers for small investors along with the popularity of ETF/Ns, our paper appeals to retail investors and provides guidance in terms of choosing the optimal hedge ratio under estimation risk.
Overlapping and specific neural correlates for empathizing, affective mentalizing, and cognitive mentalizing: A coordinate‐based meta‐analytic study
Authors: Arioli Maria , Cattaneo Zaira , Ricciardi Emiliano , Canessa Nicola
Published: July 2021

While the discussion on the foundations of social understanding mainly revolves around the notions of empathy, affective mentalizing, and cognitive mentalizing, their degree of overlap versus specificity is still unclear. We took a meta‐analytic approach to unveil the neural bases of cognitive mentalizing, affective mentalizing, and empathy, both in healthy individuals and pathological conditions characterized by social deficits such as schizophrenia and autism. We observed partially overlapping networks for cognitive and affective mentalizing in the medial prefrontal, posterior cingulate, and lateral temporal cortex, while empathy mainly engaged fronto‐insular, somatosensory, and anterior cingulate cortex. Adjacent process‐specific regions in the posterior lateral temporal, ventrolateral, and dorsomedial prefrontal cortex might underpin a transition from abstract representations of cognitive mental states detached from sensory facets to emotionally‐charged representations of affective mental states. Altered mentalizing‐related activity involved distinct sectors of the posterior lateral temporal cortex in schizophrenia and autism, while only the latter group displayed abnormal empathy related activity in the amygdala. These data might inform the design of rehabilitative treatments for social cognitive deficits.
Automated segmentation of deep brain nuclei using convolutional neural networks and susceptibility weighted imaging
Authors: Beliveau Vincent , Nørgaard Martin , Birkl Christoph , Seppi Klaus , Scherfler Christoph
Published: July 2021

The advent of susceptibility‐sensitive MRI techniques, such as susceptibility weighted imaging (SWI), has enabled accurate in vivo visualization and quantification of iron deposition within the human brain. Although previous approaches have been introduced to segment iron‐rich brain regions, such as the substantia nigra, subthalamic nucleus, red nucleus, and dentate nucleus, these methods are largely unavailable and manual annotation remains the most used approach to label these regions. Furthermore, given their recent success in outperforming other segmentation approaches, convolutional neural networks (CNN) promise better performances. The aim of this study was thus to evaluate state‐of‐the‐art CNN architectures for the labeling of deep brain nuclei from SW images. We implemented five CNN architectures and considered ensembles of these models. Furthermore, a multi‐atlas segmentation model was included to provide a comparison not based on CNN. We evaluated two prediction strategies: individual prediction, where a model is trained independently for each region, and combined prediction, which simultaneously predicts multiple closely located regions. In the training dataset, all models performed with high accuracy with Dice coefficients ranging from 0.80 to 0.95. The regional SWI intensities and volumes from the models' labels were strongly correlated with those obtained from manual labels. Performances were reduced on the external dataset, but were higher or comparable to the intrarater reliability and most models achieved significantly better results compared to multi‐atlas segmentation. CNNs can accurately capture the individual variability of deep brain nuclei and represent a highly useful tool for their segmentation from SW images.
Healthcare utilization at retirement in China
Authors: Zhou Qin , Eggleston Karen , Liu Gordon G.
Published: July 2021

Previous studies, mostly analyzing data from high‐income economies, present mixed evidence on the relationship between retirement and healthcare utilization. This study leverages administrative data for over 80,000 urban Chinese workers to explore the effect of retirement on outpatient and inpatient care utilization using a fuzzy regression discontinuity design. The analyses of medical claims from a large city in China complement and extend the current literature by providing evidence of potential mechanisms underlying increased short‐run utilization. In this relatively well‐insured population, annual total healthcare expenditures significantly increase primarily because of more intensive use of outpatient care at retirement, especially at the right tail of the distribution of outpatient visits. This increase in outpatient care appears to stem from a decline in the patient cost‐sharing rate and the reduced opportunity cost of time upon retirement, interacting with supplier‐induced demand, not from any sudden impact on health. We do not find evidence of change in inpatient care at retirement. The results hold for both females and males, and are robust to a number of sensitivity analyses.
Insulin‐like growth factor 1 gene transfer for sporadic Alzheimer's disease: New evidence for trophic factor mediated hippocampal neuronal and synaptic recovery‐based behavior improvement
Authors: Zappa Villar María Florencia , López Hanotte Juliette , Crespo Rosana , Pardo Joaquín , Reggiani Paula Cecilia
Published: July 2021

Sporadic Alzheimer's disease (sAD) is the most prevalent neurodegenerative disorder with no cure. Patients typically suffer from cognitive impairment imprinted by irreversible neocortex and hippocampal degeneration with overt synaptic and neuron dysfunction. Insulin‐like growth factor 1 (IGF1) has proven to be a potent neuroprotective molecule in animal models of age‐related neurodegeneration. In this regard, adenoviral gene transfer aiming at IGF1 brain overexpression has been hitherto an underexplored approach for the sAD treatment. We postulated enhanced IGF1 signaling in the brain as a restorative means in the diseased brain to revert cognitive deficit and restore hippocampal function. We implemented recombinant adenovirus mediated intracerebroventricular IGF1 gene transfer on the streptozotocin (STZ) induced sAD rat model, using 3‐month‐old male Sprague Dawley rats. This approach enhanced IGF1 signaling in the hippocampus and dampened sAD phosphorylated Tau. We found a remarkable short‐term improvement in species‐typical behavior, recognition memory, spatial memory, and depressive‐like behavior. Histological analysis revealed a significant recovery of immature hippocampal neurons. We additionally recorded an increase in hippocampal microglial cells, which we suggest to exert anti‐inflammatory effects. Finally, we found decreased levels of pre‐ and postsynaptic proteins in the hippocampus of STZ animals. Interestingly, IGF1 gene transfer increased the levels of PSD95 and GAD65/67 synaptic markers, indicating that the treatment enhanced the synaptic plasticity. We conclude that exogenous activation of IGF1 signaling pathway, 1 week after intracerebroventricular STZ administration, protects hippocampal immature neurons, dampens phosphorylated Tau levels, improves synaptic function and therefore performs therapeutically on the sAD STZ model. Hence, this study provides strong evidence for the use of this trophic factor to treat AD and age‐related neurodegeneration.
Long‐term ecosystem monitoring at Huntington Forest: Integrating hydrology, biogeochemistry and climatic controls on watershed processes
Authors: Beier Colin , Mills James , McHale Patrick , Driscoll Charles T. , Mitchell Myron J.
Published: July 2021

Located in the Adirondack Mountains of northern New York State, Huntington Wildlife Forest (HWF) is a 6000‐ha research and education facility operated by SUNY ESF (State University of New York, College of Environmental Science and Forestry) with continuous long‐term monitoring (LTM) programs spanning over six decades. One of the ‘cradles’ of acid rain research in North America, HWF was in the first cohort of National Atmospheric Deposition Program (NADP) sites beginning in 1978. HWF is currently the only location (NY‐20) in New York with the full suite of NADP programs in operation, including atmospheric mercury speciation (AMNet), along with EPA CASTNET. Nearby to NY‐20 at HWF, Arbutus Lake and its forested watershed have been the focus of intensive LTM since installation of v‐notch weirs at the lake outlet and inlet in 1991 and 1994, respectively. Discharge at these locations has been monitored continuously at 15‐min intervals since 1999. Lake outlet water chemistry samples were collected starting in 1983. Weekly sampling of water chemistry at both weirs began in 1995 and was expanded to include two headwater streams and groundwater wells in 2007. More recently, LTM programs at HWF have been augmented by participation in the PhenoCam Network since 2008, collection of high‐resolution LiDAR in 2009, and installation of a precision NY Mesonet weather station in 2016. In 2018, we installed sensor networks that continuously monitor soil microclimate and snow depth. Lastly, we improved data access via a new website (www.adk-ltm.org) where users can create custom queries and visualize outputs.
Changes to the genetic counseling workforce as a result of the COVID‐19 pandemic
Authors: MacFarlane Ian , Johnson Amber , Zierhut Heather
Published: July 2021

The COVID‐19 pandemic has affected all aspects of our lives. The full impact of the pandemic is still unfolding and will take years to fully understand. This longitudinal study followed a sample of 189 genetic counselors from June to November of 2020, starting with an online retrospective baseline survey of pre‐COVID‐19 functioning and continuing with a monthly online survey (average retention = 89.2%) to assess changes in self‐reported stress, employment status, billing practices, self‐efficacy, and their use of telehealth. Participants were recruited from specific states representing geographic diversity with publicly available databases of contact information as well as social media. The sample was largely reflective of the professional demographics reported in the 2020 Professional Status Survey (PSS). Comparisons were made between the PSS, baseline assessment of pre‐COVID‐19 status, June, and November data. Genetic counselor workload did not significantly change in terms of hours worked from baseline to November, though patients served per week dropped initially before returning to pre‐COVID‐19 levels. Genetic counselors were increasingly working remotely and supervising students less frequently in November compared to pre‐COVID‐19 baseline. Approximately 50% of the sample were unable to bill for services throughout the study period, with billing practices not changing during this time. Approximately 40% experienced a negative employment change in June, which dropped to ~10% in November. Personal and family stress levels were elevated during the study period, while financial stress increased from baseline to June it returned to pre‐COVID‐19 levels by November. Self‐efficacy for common genetic counseling skills decreased from baseline to June but returned to baseline levels by November. The results suggest the workforce faced transitions but has rebounded in most areas studied. The pandemic highlighted pre‐existing billing issues, and the current billing structures were not able to shift in the face of practice transitions. The long‐term implications of the pandemic remain to be seen, but the results indicate returns toward baseline data in most areas with the exceptions of supervision, personal and family stress, and billing.
New implementations for the ASPEN clinical guidelines and a call for protocol review on the nutrition guidelines for adult head and neck cancer
Authors: McKeever Liam
Published: July 2021

The current article details new upgrades to the guideline methodology, including the publication of "a priori" protocols, methods for assuring agreement between reviewers, adoption of Covidence software for tracking reasons for article exclusion, the establishment of a separate bias panel to improve study quality assessment, an algorithm for study design inclusion, and Delphi technique implementation for the management and external validation of expert opinion. These methodologic additions will provide greater transparency and accountability for the choices made during the guideline development process.
Application of Raman spectroscopy for the identification of phosphate minerals from REE supergene deposit
Authors: Zhukova Irina A. , Stepanov Aleksandr S. , Korsakov Andrey V. , Jiang Shao‐Yong
Published: July 2021

Among critical metals, rare‐earth elements (REEs) are irreplaceable for their role in the high‐tech industry. The REE deposits commonly host REEs in fine‐grained mixtures of phosphate minerals characterized by the variable content of volatile components. However, identification of the volatile components may present challenges for laser‐ablation inductively coupled plasma mass spectrometer (LA‐ICP‐MS) and electron microprobe (EPMA) techniques. Therefore, Raman spectroscopy was applied to laterite and carbonatite samples from the Mount Weld deposit, one of the major REE deposits in Western Australia. The hydrous REE phosphate, rhabdophane, can be confidently distinguished from monazite by the presence of peaks in the region 2800–3600 cm−1. The presence of peaks at 428, 448, 579, 589, and 605 cm−1 in the Raman spectra of apatite from carbonatite allows its identification as hydroxyfluorapatite with high concentrations of F and water, and negligible Cl, SO42−, and SiO42−. The Raman spectra and composition of silcrete and carbonatite apatite are similar; thus, silcrete apatite was identified as hydroxyfluorapatite as well. The content of CO32− in both types of apatite was negligible despite the crystallization from carbonatitic magma. The aluminophosphate florencite is characterized by the presence of PO43−‐related peaks at 639, 1113, and 1609 cm−1 and H2O/OH‐related bands in the 2750–3075 cm−1 and together with rhabdophane has been identified in fine‐grained mineral mixtures. Our study demonstrates that combining Raman spectroscopy with compositional data is a powerful method for the characterization of phosphate minerals in REE deposits.
Medical and aesthetic improvement of photodamaged skin by the combination of intense pulsed light and photodynamic therapy with 10% aminolevulinic acid hydrochloride gel
Authors: Abrouk Michael , Dong Joanna , Waibel Jill S.
Published: July 2021

Objective

To evaluate the efficacy and safety of photodynamic therapy (PDT) with the novel 10% aminolevulinic acid (ALA) hydrochloride gel (10% ALA gel) and BF‐RhodoLED® light (635 nm; 37 J/cm2) in combination with intense pulsed light (IPL) to augment the medical and aesthetic improvement of photodamaged skin of the décolleté.

Methods

This was a single‐site prospective, randomized, intraindividual split chest pilot study with 20 female subjects with moderate to severe photodamage of the décolleté. Subjects were randomized to ALA‐PDT + IPL to one split‐side of the chest and ALA‐PDT only to the contralateral side. Three blinded raters assessed aesthetic improvement using the global aesthetic improvement scale (GAIS).

Results

Eighteen subjects completed the study. Superior GAIS results were achieved on the ALA‐PDT + IPL treatment side than on the ALA‐PDT only treatment side (p < 0.001) after 24 weeks of follow‐up.

Conclusions

ALA‐PDT using 10% ALA hydrochloride gel and BF‐RhodoLED® light had superior rejuvenation effects on the décolleté when combined with IPL compared to ALA‐PDT alone.
Design, Bio‐evaluation and Molecular Dynamics Simulation of Novel GSK‐3β Inhibitors
Authors: Lyu Weiping , Li Qihang , Li Qi , Chen Ying , Wang Yingming , Tang Tongzhong , Feng Feng , Chi Heng , Li Yuan , Liu Wenyuan , Sun Haopeng
Published: July 2021

Glycogen synthase kinase 3 beta (GSK‐3β) is considered as a promising drug target for the treatment of Alzheimer's disease (AD). In the present study, two compound libraries were selected for virtual screening based on pharmacophore models of GSK‐3β to discover new inhibitors. Nine potential hits were retained for biological investigation and four of these compounds showed GSK‐3β inhibitory activity (with the IC50 values in sub‐micromolar range on GSK‐3β). Compounds 6 and 9 have good safety. They do not have any significant in vitro cytotoxicity against PC12 and SH‐SY5Y neuroblastoma cells at concentrations up to 90 μM. Based on the inhibitory activity and druggability properties, compound 8 is the preferred molecule, and it is a promising lead for the development of the GSK‐3β inhibitors for reducing the abnormal hyperphosphorylation of tau protein and relieving AD.
Archaeogeophysical exploration in Neuss‐Norf, Germany using electrical resistivity tomography and magnetic data
Authors: Ibraheem Ismael M. , Bergers Rainer , Tezkan Bülent
Published: July 2021

A combination of electrical resistivity tomography (ERT) and magnetic gradiometry was selected to examine a hypothesis concerning the presence of remains of one of the oldest archaeological churches in the Rhineland, located in Neuss‐Norf, Germany. The gradiometer survey was carried out to measure the vertical gradient of the magnetic field using a proton precession magnetometer along several profiles. The magnetic data were reduced to the magnetic pole; then analytic signal and power spectrum techniques were applied. The ERT survey was based on the magnetic results, and both Wenner and dipole–dipole configurations were employed to collect the apparent resistivity data along 12 ERT profiles. The field ERT data from these two arrays were merged into one dataset to form a non‐conventional mixed array. The robust (blocky) inversion technique was applied to the resistivity data in order to derive the two‐dimensional resistivity distribution of the subsurface. Despite the noisy surroundings, the magnetic survey was able to give an indication of potential walls of the ancient church in addition to several subsurface magnetic sources. Moreover, highly resistivity anomalies were observed within the first 1–2 m of the subsurface soil and were interpreted as possible remains of man‐made structures. This depth range was also confirmed by the spectral analysis of the magnetic data. A strong consistency between the two methods was observed in some locations of the site. In addition, the ERT measurements confirm and complement most of the magnetic results. We successfully detected anomalous zones that could be associated with the walls of at least one ancient church building in addition to several possible archaeological structures in the survey area.
First principle investigations of long‐range magnetic exchange interactions via polyacene couplers
Authors: Kaur Prabhleen , Ali Md. Ehesan
Published: July 2021

The electronic and magnetic properties of polyacenes become quite fascinating as the number of linearly conjugated benzene rings increases. Higher‐order conjugated polyacenes develop radicaloid characters due to the transition of electronic structures from closed‐shell to the open‐shell system. Here we have investigated the role of such polyacenes as the magnetic coupler when placed between the two spin‐sources based on nitroxy radicals. To do so, the magnetic exchange interactions () are computed employing broken‐symmetry (BS) approach within the density functional theory (DFT). In this approach, various genre of exchange‐ correlation (XC) functionals such as generalized gradient approximation (GGA), meta‐GGA, hybrid functional, constrained spin density (i.e. CDFT) and on‐site Coulomb correlation corrected GGA + U functionals are adopted. All DFT based calculations estimate an exponential increase in values with the length of the couplers. This observation has been understood in terms of increase in number of near‐degenerate or quasi‐degenerate molecular orbitals (MOs), reduction of HOMO‐LUMO energy gap and descend of low‐lying excited states as the number of fused benzene rings are increased.