bluuebunny/crossref_metadata_2025 huggingface dataset:
Stable Radicals with Protective Umbrellas Integrated on the Surface of 2D Layered Materials
Authors: Chen Yuanyuan , Peng Jian , Sheng Tian , Qin Ruixuan , Dai Shuqi , Shi Zaifa , Tang Zichao , Wang Laisen , Zhang Qinghua , Han Bin , Sun Liping , Xu Jun , Weng Jian
Published: July 2021

Radicals are closely related to human life and health and have been widely used in biology, chemistry, functional materials, etc. However, the high reactivity, disorder, and short half‐lives limit their wide applications. Therefore, it remains a great challenge to prepare stable and ordered radicals. Herein, radicals are prepared with protective umbrellas (diethylmethyleneamine, DEMA) that are integrated on the surface of 2D layered materials to isolate water and oxygen and enhance the stability of radicals. Taking 2D black phosphorus (BP) as an example: triethylamine reacts with dichloromethane to form quaternary ammonium salts with further Hoffmann elimination to produce DEMA radicals that could react with one electron of a lone pair electrons in P on the surface of BP to produce P radicals, which shows a prolonged half‐life of 21 days at room temperature. First‐principle calculations and electron paramagnetic resonance fitting confirm that the steric hindrance constructed by dense DEMA passivation layer acts as a protective umbrella and the 2D coupling of P radicals and other P atoms in 2D BP plane to enhance the stability and strong superexchange interaction of P radicals. Furthermore, it is a general strategy to produce stable radicals integrated on the 2D plane.
Photoactive Lanthanide‐Based Upconverting Nanoclusters for Antimicrobial Applications
Authors: Kandoth Noufal , Barman Subhadip , Chatterjee Atin , Sarkar Sandip , Dey Anik Kumar , Pramanik Sumit Kumar , Das Amitava
Published: July 2021

Developing photoactive nanosystems against microbial infection and its therapeutic application is compromised by the lack of suitable materials or molecular dyes activatable at biofriendly NIR light. In this direction, the upconverting nanoparticles based on core–shell lanthanide‐doped nanoclusters are developed synthetically to achieve a broad range of NIR‐active phototherapeutic antimicrobial agents. This review illustrates antimicrobial photodynamic therapy (aPDT) and multimodal therapy by NIR photoirradiation, generated by lanthanum doped upconverting nanoparticles (UCNPs). The objective herein is to discuss the insights in developing the UCNPs for designing efficient aPDTs and their efficacies against emerging antibiotic‐resistant bacterial colonies and their biofilms, drug‐resistant fungi, and viruses. The biosafety and biocompatibility of UCNPs at both in vitro and in vivo level are also presented in detail. Finally, our perspectives on the ways of future material engineering needed for the effective translation into their real‐world applications are also commented.
New Insights into the High‐Performance Black Phosphorus Anode for Lithium‐Ion Batteries
Authors: Li Minsi , Li Weihan , Hu Yongfeng , Yakovenko Andrey A. , Ren Yang , Luo Jing , Holden William M. , Shakouri Mohsen , Xiao Qunfeng , Gao Xuejie , Zhao Feipeng , Liang Jianwen , Feng Renfei , Li Ruying , Seidler Gerald T. , Brandys Frank , Divigalpitiya Ranjith , Sham Tsun‐Kong , Sun Xueliang
Published: July 2021

Black phosphorus (BP) is a promising anode material in lithium‐ion batteries (LIBs) owing to its high electrical conductivity and capacity. However, the huge volume change of BP during cycling induces rapid capacity fading. In addition, the unclear electrochemical mechanism of BP hinders the development of rational designs and preparation of high‐performance BP‐based anodes. Here, a high‐performance nanostructured BP–graphite–carbon nanotubes composite (BP/G/CNTs) synthesized using ball‐milling method is reported. The BP/G/CNTs anode delivers a high initial capacity of 1375 mA h g−1 at 0.15 A g−1 and maintains 1031.7 mA h g−1 after 450 cycles. Excellent high‐rate performance is demonstrated with a capacity of 508.1 mA h g−1 after 3000 cycles at 2 A g−1. Moreover, for the first time, direct evidence is provided experimentally to present the electrochemical mechanism of BP anodes with three‐step lithiation and delithiation using ex situ X‐ray diffraction (XRD), ex situ X‐ray absorption spectroscopy (XAS), ex situ X‐ray emission spectroscopy, operando XRD, and operando XAS, which reveal the formation of Li3P7, LiP, and Li3P. Furthermore, the study indicates an open‐circuit relaxation effect of the electrode with ex situ and operando XAS analyses.
Surface Diffusion and Epitaxial Self‐Planarization for Wafer‐Scale Single‐Grain Metal Chalcogenide Thin Films
Authors: Giri Anupam , Kumar Manish , Kim Jaeseon , Pal Monalisa , Banerjee Writam , Nikam Revannath Dnyandeo , Kwak Junghyeok , Kong Minsik , Kim Seong Hun , Thiyagarajan Kaliannan , Kim Geonwoo , Hwang Hyunsang , Lee Hyun Hwi , Lee Donghwa , Jeong Unyong
Published: July 2021

Although wafer‐scale single‐grain thin films of 2D metal chalcogenides (MCs) have been extensively sought after during the last decade, the grain size of the MC thin films is still limited in the sub‐millimeter scale. A general strategy of synthesizing wafer‐scale single‐grain MC thin films by using commercial wafers (Si, Ge, GaAs) both as metal source and epitaxial collimator is presented. A new mechanism of single‐grain thin‐film formation, surface diffusion, and epitaxial self‐planarization is proposed, where chalcogen elements migrate preferentially along substrate surface and the epitaxial crystal domains flow to form an atomically smooth thin film. Through synchrotron X‐ray diffraction and high‐resolution scanning transmission electron microscopy, the formation of single‐grain Si2Te3, GeTe, GeSe, and GaTe thin films on (111) Si, Ge, and (100) GaAs is verified. The Si2Te3 thin film is used to achieve transfer‐free fabrication of a high‐performance bipolar memristive electrical‐switching device.
Molecular Engineering of Hydrogels for Rapid Water Disinfection and Sustainable Solar Vapor Generation
Authors: Guo Youhong , Dundas Christopher M. , Zhou Xingyi , Johnston Keith P. , Yu Guihua
Published: July 2021

Consumption of unsafe water is a major cause of morbidity and mortality in developing regions. Pasteurizing or boiling water to remove pathogens is energy‐intensive and often impractical to off‐grid communities. Therefore, low capital cost, rapid and energy‐efficient water disinfection methods are urgently required to address global challenges of safe water access. Here, anti‐bacterial hydrogels (ABHs) with catechol‐enabled molecular‐level hydrogen peroxide generators and quinone‐anchored activated carbon particles are designed for effective water treatment. The bactericidal effect is attributed to the synergy of hydrogen peroxide and quinone groups to attack essential cell components and disturb bacterial metabolism. ABHs can be directly used as tablets to achieve >99.999% water disinfection efficiency within 60 min without energy input. No harmful byproducts are formed during the treatment process, after which the ABH tablets can be easily removed without residues. Taking advantage of their excellent photothermal and biofouling‐resistant properties, ABHs can also be applied as solar evaporators to achieve stable water purification under sunlight (≤1 kW m−2) after months of storage and operation in bacteria‐containing river water. The ABH platform offers reduced energy and chemical demands for point‐of‐use water treatment technologies in remote areas and emergency rescue applications.
Avoiding the Center‐Symmetry Trap: Programmed Assembly of Dipolar Precursors into Porous, Crystalline Molecular Thin Films
Authors: Nefedov Alexei , Haldar Ritesh , Xu Zhiyun , Kühner Hannes , Hofmann Dennis , Goll David , Sapotta Benedikt , Hecht Stefan , Krstić Marjan , Rockstuhl Carsten , Wenzel Wolfgang , Bräse Stefan , Tegeder Petra , Zojer Egbert , Wöll Christof
Published: July 2021

Liquid‐phase, quasi‐epitaxial growth is used to stack asymmetric, dipolar organic compounds on inorganic substrates, permitting porous, crystalline molecular materials that lack inversion symmetry. This allows material fabrication with built‐in electric fields. A new programmed assembly strategy based on metal–organic frameworks (MOFs) is described that facilitates crystalline, noncentrosymmetric space groups for achiral compounds. Electric fields are integrated into crystalline, porous thin films with an orientation normal to the substrate. Changes in electrostatic potential are detected via core‐level shifts of marker atoms on the MOF thin films and agree with theoretical results. The integration of built‐in electric fields into organic, crystalline, and porous materials creates possibilities for band structure engineering to control the alignment of electronic levels in organic molecules. Built‐in electric fields may also be used to tune the transfer of charges from donors loaded via programmed assembly into MOF pores. Applications include organic electronics, photonics, and nonlinear optics, since the absence of inversion symmetry results in a clear second‐harmonic generation signal.
Atomistic Insights on the Rheological Property of Polycaprolactone Composites with the Addition of Graphene
Authors: Nie Yihan , Zhan Haifei , Kou Liangzhi , Gu Yuantong
Published: July 2021

To facilitate the biomedical applications of biocomposites, researchers have used different types of fillers to enhance their mechanical properties. However, the addition of fillers not only changes the mechanical performance of the biocomposites, but also affects their printability, that is, their rheological properties. With the aid of atomistic simulations, this work investigates the influence of graphene size and aggregation on the rheological properties of polycaprolactone (PCL) composites. For the same weight ratio, increasing the graphene size causes the viscosity of the PCL composite to increase until a threshold edge length equal to PCL's average radius of gyration. After this threshold value, the viscosity decreases with increasing edge length. The PCL composite with multilayered graphene exhibits a lower viscosity compared with its counterpart with monolayer graphene. Specifically, the addition of graphene is shown to augment the shear‐thinning effect. The findings in this work provide a fundamental understanding of the rheological property of PCL composites with the addition of 2D nanofillers, which shed light on the ink design for bioprinting.
Electrotherapies for Glioblastoma
Authors: Jenkins Elise P. W. , Finch Alina , Gerigk Magda , Triantis Iasonas F. , Watts Colin , Malliaras George G.
Published: July 2021

Non‐thermal, intermediate frequency (100–500 kHz) electrotherapies present a unique therapeutic strategy to treat malignant neoplasms. Here, pulsed electric fields (PEFs) which induce reversible or irreversible electroporation (IRE) and tumour‐treating fields (TTFs) are reviewed highlighting the foundations, advances, and considerations of each method when applied to glioblastoma (GBM). Several biological aspects of GBM that contribute to treatment complexity (heterogeneity, recurrence, resistance, and blood‐brain barrier(BBB)) and electrophysiological traits which are suggested to promote glioma progression are described. Particularly, the biological responses at the cellular and molecular level to specific parameters of the electrical stimuli are discussed offering ways to compare these parameters despite the lack of a universally adopted physical description. Reviewing the literature, a disconnect is found between electrotherapy techniques and how they target the biological complexities of GBM that make treatment difficult in the first place. An attempt is made to bridge the interdisciplinary gap by mapping biological characteristics to different methods of electrotherapy, suggesting important future research topics and directions in both understanding and treating GBM. To the authors' knowledge, this is the first paper that attempts an in‐tandem assessment of the biological effects of different aspects of intermediate frequency electrotherapy methods, thus offering possible strategies toward GBM treatment.
Phononic Thermal Transport along Graphene Grain Boundaries: A Hidden Vulnerability
Authors: Tong Zhen , Pecchia Alessandro , Yam ChiYung , Dumitrică Traian , Frauenheim Thomas
Published: July 2021

While graphene grain boundaries (GBs) are well characterized experimentally, their influence on transport properties is less understood. As revealed here, phononic thermal transport is vulnerable to GBs even when they are ultra‐narrow and aligned along the temperature gradient direction. Non‐equilibrium molecular dynamics simulations uncover large reductions in the phononic thermal conductivity (κp) along linear GBs comprising periodically repeating pentagon‐heptagon dislocations. Green's function calculations and spectral energy density analysis indicate that the origin of the κp reduction is hidden in the periodic GB strain field, which behaves as a reflective diffraction grating with either diffuse or specular phonon reflections, and represents a source of anharmonic phonon–phonon scattering. The non‐monotonic dependence with dislocation density of κp uncovered here is unaccounted for by the classical Klemens theory. It can help identify GB structures that can best preserve the integrity of the phononic transport.
Comparing and Quantifying Indoor Performance of Organic Solar Cells
Authors: Lübke Dana , Hartnagel Paula , Angona Johanna , Kirchartz Thomas
Published: July 2021

With increasing efficiencies of non‐fullerene acceptor‐based organic solar cells, thin‐film technology is becoming a promising candidate for indoor light harvesting applications. However, the lack of standardized comparison methods makes it difficult to quantify progress and to compare indoor performance. Herein, a simple method to calculate the efficiency of solar cells under any possible light source and illuminance with only using simple standard measurements (current–voltage curves and quantum efficiency) is presented. Thereby, equal evaluation conditions are ensured, so that indoor solar cells can be ranked and compared according to their efficiency. Efficiencies are shown to typically vary by ±20% when using different different light emitting diode spectra with color temperatures ranging from 2700 to 6500 K. Calculations based on a detailed balance model indicate that the optimal bandgap of the absorber material depends on the used light source and ranges between 1.75 and 2 eV. The approach is validated by comparison with literature data and many calculated efficiencies match well with experimental data obtained with a specific light source. However, some reported efficiencies cannot be reproduced with the model, which highlights the need to reassess low light measuring techniques. Furthermore, a script is provided for use by the community.
A Thiadiazole‐Based Conjugated Polymer with Ultradeep HOMO Level and Strong Electroluminescence Enables 18.6% Efficiency in Organic Solar Cell
Authors: Zhang Tao , An Cunbin , Bi Pengqing , Lv Qianglong , Qin Jinzhao , Hong Ling , Cui Yong , Zhang Shaoqing , Hou Jianhui
Published: July 2021

Under the premise of ensuring favorable bulk heterojunction morphology in organic solar cells (OSCs), conjugated polymer donors with deep‐lying highest occupied molecular orbital (HOMO) levels are highly important to improve power conversion efficiencies (PCEs) by reducing photovoltage loss. However, the development of such materials has lagged. Herein, a thiadiazole‐based conjugated polymer, PB2F is reported, which has a very deep HOMO level of −5.64 eV, and high electroluminescence quantum efficiency of 3.9 × 10−3. In OSCs, the PB2F‐based OSC gives an excellent PCE of 14.5% with an ultrahigh open‐circuit voltage (VOC) of 0.957 V by blending with an electron acceptor of IT‐4F. More importantly, the PB2F as a third component is added into the PBDB‐TF:BTP‐eC9 blend to achieve an outstanding PCE of 18.6% (certified PCE 18.2%), which is one of the highest PCEs in OSCs.
Regenerative agriculture and integrative permaculture for sustainable and technology driven global food production and security
Authors: McLennon Everald , Dari Biswanath , Jha Gaurav , Sihi Debjani , Kankarla Vanaja
Published: July 2021

A growing world population and increases in food and energy consumption have placed production agriculture in a difficult situation. The rapid growth in food production through specialized operations such as monoculture cropping systems has aligned to satisfy increases in demand for food and fiber. However, its adverse impacts on natural resources pose huge challenges for the sustainability of food production. The situation is direr for developing countries or rural regions of the world due to the limited resources available to farming communities in these regions. To avoid production agriculture being at the proverbial crossroads we suggest an alternate approach. One that involves the sustainable use of natural resources without adverse environmental impacts by relying less on production inputs whether it be agrochemicals or machineries. We examined the extent to which regenerative agriculture, permaculture, and smart technology have evolved in response to sustainable agricultural production, agricultural decision support system, and overall global food security. Collectively, regenerative agriculture and permaculture are semi‐closed holistic systems approach designed to reduce or eliminate dependence on external inputs (e.g., chemicals) which restores and maintains natural systems (e.g., soil quality, biodiversity, and ecosystem services). We suggest that fully embracing modern regenerative agriculture as well as integrated permaculture will improve soil health, ecosystem biodiversity, land and resource conservation, agricultural sustainability, and food security. Identifying and implementing practices towards regenerative agriculture, integrated permaculture, digital agriculture, and sustainable agricultural management utilizing modern agricultural technologies infused with data science (artificial intelligence [AI] or machine learning [ML]) is critical.
What is the best anthropometric predictor for identifying higher risk for cardiovascular diseases in afro‐descendant Brazilian women? A cross‐sectional population‐based study
Authors: Ferreira Haroldo S. , Soares Mariana L. , Krakauer Nir Y. , Santos Ewerton A. , Krakauer Jesse C. , Uchôa Tainá C. , Santos Tamara R. , dos Anjos Luiz Antonio
Published: July 2021

Objectives

Excessive adiposity is associated with cardiovascular disease (CVD). Anthropometric indices are useful in screening individuals at higher risk for these diseases. However, there are no studies that show which of these indices has the best discriminatory power among Afro‐descendant Brazilian women. The objective of this study was to assess the accuracy of anthropometric indices in identifying risk factors for CVD in Afro‐descendant Brazilian women and define the one most suitable for use under the operating conditions prevailing in Quilombola communities.

Methods

A household random sample of 1661 women descendants of African slaves were analyzed. The anthropometric predictors analyzed were waist circumference (WC), body mass index, waist‐to‐height ratio, conicity index (C‐index), body shape index, and percentage of body fat (%BF; estimated by bioimpedance). The assessed risk factors for CVD were arterial hypertension, diabetes mellitus, and dyslipidemias (hypertriglyceridemia; hypercholesterolemia; low high‐density lipoprotein). To identify the statistical significance between the differences in the areas under the ROC curves (AUC) obtained with the different predictors and outcomes, was used the Bonferroni test adjusted for multiple analyses by the Sidak method.

Results

The AUC obtained with WC was higher (p < .05) or similar (p > .05) to those obtained with the other predictors 29 times out of 30 possibilities (six predictors x five outcomes). Only the AUC obtained with C‐index in identifying hypercholesterolemia was significantly higher than that with WC.

Conclusion

Due to its accuracy and greater operational simplicity, WC was the most adequate predictor for identifying Afro‐descendant women at greatest risk for CVD.
Cleft palate morphology, genetic etiology, and risk of mortality in infants with Robin sequence
Authors: Wenger Tara L. , Perkins Jonathan , Parish‐Morris Julia , Hing Anne V. , Chen Maida L. , Cielo Christopher M. , Li Dong , Bhoj Elizabeth J. , Hakonarson Hakon , Zackai Elaine , McDonald‐McGinn Donna M. , Taylor Jesse A. , Jackson Oksana , Sie Kathleen , Bly Randall , Dahl John , Evans Kelly N.
Published: July 2021

Robin sequence (RS) has many genetic and nongenetic causes, including isolated Robin sequence (iRS), Stickler syndrome (SS), and other syndromes (SyndRS). The purpose of this study was to determine if the presence and type of cleft palate varies between etiologic groups. A secondary endpoint was to determine the relationship of etiologic group, cleft type, and mortality. Retrospective chart review of patients with RS at two high‐volume craniofacial centers. 295 patients with RS identified. CP was identified in 97% with iRS, 95% with SS, and 70% of those with SyndRS (p < .0001). U‐shaped CP was seen in 86% of iRS, 82% with SS, but only 27% with SyndRS (p < .0001). At one institution, 12 children (6%) with RS died, all from the SyndRS group (p < .0001). All died due to medical comorbidities related to their syndrome. Only 25% of children who died had a U‐shaped CP. The most common palatal morphology among those who died was an intact palate. U‐shaped CP was most strongly associated with iRS and SS, and with a lower risk of mortality. RS with submucous CP, cleft lip and palate or intact palate was strongly suggestive of an underlying genetic syndrome and higher risk of mortality.
Radical 1,4‐Aryl Migration Enabled Remote Cross‐Electrophile Coupling of α‐Amino‐β‐Bromo Acid Esters with Aryl Bromides
Authors: Tang Shi , Xu Zhen‐Hua , Liu Ting , Wang Shuo‐Wen , Yu Jian , Liu Jian , Hong Yu , Chen Shi‐Lu , He Jin , Li Jin‐Heng
Published: July 2021

We report an unprecedented, efficient nickel‐catalysed radical relay for the remote cross‐electrophile coupling of β‐bromo‐α‐benzylamino acid esters with aryl bromides via 1,4‐aryl migration/arylation cascades. β‐Bromo‐α‐benzylamino acid esters are considered as unique molecular scaffolds allowing for aryl migration reactions, which are conceptually novel variants for the radical Truce–Smiles rearrangement. This reaction enables the formation of two new C(sp3)−C(sp2) bonds using a bench‐stable Ni/bipyridine/Zn system featuring a broad substrate scope and excellent diastereoselectivity, which provides an effective platform for the remote aryl group migration and arylation of amino acid esters via redox‐neutral C(sp3)−C(sp2) bond cleavage. Mechanistically, this cascade reaction is accomplished by combining two powerful catalytic cycles consisting of a cross‐electrophile coupling and radical 1,4‐aryl migration through the generation of C(sp3)‐centred radical intermediates from the homolysis of C(sp3)−Br bonds and the switching of the transient alkyl radical into a robust α‐aminoalkyl radical.
After 200 Years: The Structure of Bleach and Characterization of Hypohalite Ions by Single‐Crystal X‐Ray Diffraction**
Authors: Topić Filip , Marrett Joseph M. , Borchers Tristan H. , Titi Hatem M. , Barrett Christopher J. , Friščić Tomislav
Published: July 2021

We report the first X‐ray single crystal structures of hypochlorite (ClO−) and hypobromite (BrO−) salts, including hydrated sodium hypochlorite, a staple of the chlorine industry and ubiquitous bleaching and disinfection agent for almost 200 years. The structures, supported by variable‐temperature Raman spectroscopy on individual crystals and periodic density‐functional theory (DFT) calculations, provide insight into solid‐state geometry and supramolecular chemistry of hypohalite ions.
Fabrication of Differently Shaped Polymeric Nanoneedle Arrays via Multistep Plasma Etching Using Silica Microparticles as Masks
Authors: Lee Dong‐Hyun , Park Hyung Joon , Park Yong Gi Cha , Lee Kyu Back
Published: July 2021

We established a method to produce differently shaped polymeric nanoneedle arrays using silica microparticles by using multistep plasma etch processes. The etching conditions of each step were determined by exploring etching parameters such as power, bias power, gas composition and amount, pressure and time. The silica microparticles became unstable and irregular nanoneedle arrays were formed due to difference of etching rates between silica and polymer when silica microparticles were etched continuously in one step. Through the introduction of stabilization step in which selective etching is done on silica microparticle to reduce the diameter of silica microparticles and hence to move the center of mass of the silica microparticle inward, the instability of silica mask was removed and irregularity of nanostructures was minimized. As a result, multistep etching process to fabricate polymeric nanoneedle arrays was established. Depending on the conditions of each step, polymeric nanostructure arrays with various morphology were fabricated.
A novel undergraduate biomedical laboratory course concept in synergy with ongoing faculty research
Authors: Schot Willemijn D. , Hegeman Maria A. , ten Broeke Toine , Valentijn Floris A. , Meijerman Irma , Prins Frans J. , Dictus Wim J. A. G. , Bovenschen Niels
Published: July 2021

Optimal integration of education and ongoing faculty research in many undergraduate science programs is limited to the capstone project. Here, we aimed to develop a novel course‐based undergraduate research experience (CURE) in synergy with ongoing faculty research. This 10‐week course called Biomedical Research Lab is embedded in the curriculum of the undergraduate program Biomedical Sciences and grounded in the theoretical framework of research‐based learning. Four groups of four students work together in a dedicated laboratory on an actual ongoing research problem of faculty. All groups work on the same research problem, albeit from different (methodological) perspectives, thereby stimulating interdependence between all participants. Students propose new research, execute the experiments, and collectively report in a single research article. According to students, the course enhanced scientific, laboratory, and academic skills. Students appreciated ownership and responsibilities of the research, laboratory teachers as role models, and they were inspired and motivated by doing authentic actual research. The course resulted in a better understanding of what doing research entails. Faculty valued the didactical experience, research output and scouting opportunities. Since topics can change per course edition, we have showcased a widely applicable pedagogy creating synergy between ongoing research and undergraduate education.
Large‐scale collaboration in ENIGMA‐EEG: A perspective on the meta‐analytic approach to link neurological and psychiatric liability genes to electrophysiological brain activity
Authors: Smit Dirk J. A. , Andreassen Ole A. , Boomsma Dorret I. , Burwell Scott J. , Chorlian David B. , de Geus Eco J. C. , Elvsåshagen Torbjørn , Gordon Reyna L. , Harper Jeremy , Hegerl Ulrich , Hensch Tilman , Iacono William G. , Jawinski Philippe , Jönsson Erik G. , Luykx Jurjen J. , Magne Cyrille L. , Malone Stephen M. , Medland Sarah E. , Meyers Jacquelyn L. , Moberget Torgeir , Porjesz Bernice , Sander Christian , Sisodiya Sanjay M. , Thompson Paul M. , van Beijsterveldt Catharina E. M. , van Dellen Edwin , Via Marc , Wright Margaret J.
Published: July 2021

Background and purpose

The ENIGMA‐EEG working group was established to enable large‐scale international collaborations among cohorts that investigate the genetics of brain function measured with electroencephalography (EEG). In this perspective, we will discuss why analyzing the genetics of functional brain activity may be crucial for understanding how neurological and psychiatric liability genes affect the brain.

Methods

We summarize how we have performed our currently largest genome‐wide association study of oscillatory brain activity in EEG recordings by meta‐analyzing the results across five participating cohorts, resulting in the first genome‐wide significant hits for oscillatory brain function located in/near genes that were previously associated with psychiatric disorders. We describe how we have tackled methodological issues surrounding genetic meta‐analysis of EEG features. We discuss the importance of harmonizing EEG signal processing, cleaning, and feature extraction. Finally, we explain our selection of EEG features currently being investigated, including the temporal dynamics of oscillations and the connectivity network based on synchronization of oscillations.

Results

We present data that show how to perform systematic quality control and evaluate how choices in reference electrode and montage affect individual differences in EEG parameters.

Conclusion

The long list of potential challenges to our large‐scale meta‐analytic approach requires extensive effort and organization between participating cohorts; however, our perspective shows that these challenges are surmountable. Our perspective argues that elucidating the genetic of EEG oscillatory activity is a worthwhile effort in order to elucidate the pathway from gene to disease liability.
Rivastigmine for minor visual hallucinations in Parkinson's disease: A randomized controlled trial with 24 months follow‐up
Authors: van Mierlo Tom J. M. , Foncke Elisabeth M. J. , Post Bart , Schmand Ben A. , Bloem Bastiaan R. , van Harten Barbera , Tissingh Gerrit , Munts Alexander G. , de Haan Rob J. , de Bie Rob M. A. ,   other individuals of the CHEVAL Study Group
Published: July 2021

Background

Visual hallucinations are common in patients with Parkinson's disease and represent probably the major independent predictor for cognitive deterioration and nursing home placement.

Objective

To investigate if treatment of minor visual hallucinations in Parkinson's disease with rivastigmine delays the progression to psychosis.

Methods

A multicenter, randomized, double‐blind, placebo‐controlled trial was conducted which aimed to recruit 168 patients with Parkinson's disease reporting minor visual hallucinations 4 weeks before it. Important exclusion criteria were Parkinson's disease dementia, current delirium, and treatment with antipsychotics or drugs that have significant anti‐cholinergic side effects. Subjects were randomized to rivastigmine capsules, 3–6 mg twice a day, or placebo for 24 months. The primary outcome was the time to Parkinson's disease psychosis, which was defined as the need to start with antipsychotics.

Results

The trial was stopped prematurely because of slow recruitment. Ninety‐one patients were randomized: 46 patients were assigned to rivastigmine and 45 patients to placebo. No effect of rivastigmine could be demonstrated on the transition time to psychosis or dementia during the 24‐month follow‐up period. After 6 months of study treatment, cognition, mood, motor performance, and non‐motor performance did not differ significantly between the rivastigmine‐group and the placebo‐group.

Conclusions

Because the study was terminated early, it was insufficiently powered to properly evaluate the primary outcome. The limited data of the study favor a wait and see approach instead of early treatment with rivastigmine in PD patients with minor VH.
Aqueous‐alcoholic Ferulla extract reduces memory impairments in rats exposed to cadmium chloride
Authors: Fadaei Homeyra , Mirhosseiniardakani Soheilaalsadat , Farajzadeh Asghar , Aghayan Seyed Sharokh , Jafarisani Moslem , Garmabi Behzad
Published: July 2021

Introduction

Cadmium (Cd) is the most dangerous heavy metal that is becoming more widespread in nature as a result of industrial activities. One of the toxic effects of Cd on the body is its neurological effect. The mechanism of these effects has been attributed to the induction of oxidative stress. Ferulla plant has antioxidant properties. In the present study, the aim was to reduce the toxic effects of Cd on memory impairment in rats by through the consumption of Ferulla extract.

Materials & Method

Rats were randomly divided into five groups of six: (1) control group, (2) 300 μM cadmium exposure group, and three treatment groups with doses of (3) 100, (4) 300, and (5) 600 mg/kg.BW of F. Ferulla extract after Cd exposure. To induce neurotoxicity, Cd was daily injected peritoneally at a concentration of 300 μM in 1 ml of normal saline for a week. Next, for 3 weeks, the Cd group received 1 ml of normal peritoneal saline, and the treatment groups received F. Ferulla extract at concentrations of 100, 300, and 600 mg/kg.BW in 1 ml of normal saline daily for a week. At the end of the treatment period, a water maze was used to assess memory disorders. Malondialdehyde (MDA), glutathione concentration (GSH), and glutathione peroxidase (GPX) activity in nerve tissue were also measured. Morris water maze was also performed after intervention.

Results

Cd‐induced neurotoxicity was shown in Cd groups. MDA, GSH, and GPX have a significant difference in comparison between the Cd and 300, 600 treated groups. MDA has a significant increase (p < 0.05), and GSH and GPX have a significant decrease (p < 0.05). The results of the Morris water maze showed that the Cd group spent either 300 or 600 more distances and time to find a place to escape, which was significant (p < 0.05)

Conclusion

Cd exposure can induce neurotoxicity and disrupt learning and memory. On the other hand, Ferulla extract can improve learning and memory in Cd‐induced neurotoxicity model via induced antioxidant defense system.
Non‐motor phenotypic subgroups in adult‐onset idiopathic, isolated, focal cervical dystonia
Authors: Wadon Megan E. , Bailey Grace A. , Yilmaz Zehra , Hubbard Emily , AlSaeed Meshari , Robinson Amy , McLauchlan Duncan , Barbano Richard L. , Marsh Laura , Factor Stewart A. , Fox Susan H. , Adler Charles H. , Rodriguez Ramon L. , Comella Cynthia L. , Reich Stephen G. , Severt William L. , Goetz Christopher G. , Perlmutter Joel S. , Jinnah Hyder A. , Harding Katharine E. , Sandor Cynthia , Peall Kathryn J.
Published: July 2021

Background: Non‐motor symptoms are well established phenotypic components of adult‐onset idiopathic, isolated, focal cervical dystonia (AOIFCD). However, improved understanding of their clinical heterogeneity is needed to better target therapeutic intervention. Here, we examine non‐motor phenotypic features to identify possible AOIFCD subgroups.

Methods: Participants diagnosed with AOIFCD were recruited via specialist neurology clinics (dystonia wales: n = 114, dystonia coalition: n = 183). Non‐motor assessment included psychiatric symptoms, pain, sleep disturbance, and quality of life, assessed using self‐completed questionnaires or face‐to‐face assessment. Both cohorts were analyzed independently using Cluster, and Bayesian multiple mixed model phenotype analyses to investigate the relationship between non‐motor symptoms and determine evidence of phenotypic subgroups.

Results: Independent cluster analysis of the two cohorts suggests two predominant phenotypic subgroups, one consisting of approximately a third of participants in both cohorts, experiencing increased levels of depression, anxiety, sleep impairment, and pain catastrophizing, as well as, decreased quality of life. The Bayesian approach reinforced this with the primary axis, which explained the majority of the variance, in each cohort being associated with psychiatric symptomology, and also sleep impairment and pain catastrophizing in the Dystonia Wales cohort.

Conclusions: Non‐motor symptoms accompanying AOIFCD parse into two predominant phenotypic sub‐groups, with differences in psychiatric symptoms, pain catastrophizing, sleep quality, and quality of life. Improved understanding of these symptom groups will enable better targeted pathophysiological investigation and future therapeutic intervention.
Support for rights of Syrian refugees in Turkey: The role of secondary transfer effects in intergroup contact
Authors: Ünver Halime , Çakal Hüseyin , Güler Meltem , Tropp Linda R.
Published: July 2021

This study explored the role of secondary transfer effects (STEs) to test whether and how contact between advantaged Turks and disadvantaged Kurds may shape support for the rights of Syrian refugees. We investigated whether dimensions of contact, positive versus negative, between a historically advantaged group (Turks, n = 300) and a disadvantaged group (Kurds, n = 127), extend to a novel disadvantaged outgroup (Syrian refugees) via attitude generalization and as a function of the perceived threat from the novel outgroup. Controlling for the effects of contact with Syrian refugees, findings show that both positive and negative contacts with the primary outgroups are associated with support for policies benefiting the secondary outgroup, Syrian refugees, but these associations are moderated by perceived threats posed by the secondary outgroup. We discuss the implications of these findings for future research on secondary transfer processes of contact and for research on multiple group contexts. Please refer to the Supplementary Material section to find this article's Community and Social Impact Statement.
The Dirichlet model in marketing
Authors: Driesener Carl , Rungie Cam
Published: July 2021

We present a review of Gerald Goodhardt's most famous contribution to marketing science—the NBD‐Dirichlet model. This provides a powerful illustration of the complex pathway and useful associated discoveries that over 25 years lead to the specification and application of a key marketing model. We identify the process that started with the negative binomial distribution (NBD) applied to purchase incidence, examined alternatives such as the logarithmic series distribution (LSD) and the beta binomial distribution (BBD), and along the way developed conditional trend analysis (CTA). We then explore the development of brand choice beginning with duplication of purchase as a method for understanding the underlying patterns, before moving into various approaches to modelling choice including a multivariate NBD, and eventually a multivariate BBD—the Dirichlet multinomial distribution (DMD). We discuss key events in modelling consumer behaviour and outline the model's implications for how marketers should think about consumers, or more specifically the Dirichlet consumer. Finally, we provide a survey of the model's applications uncovering a rich recent history and bright future for Goodhardt's legacy.
Molecular Electrocatalytic Hydrogenation of Carbonyls and Dehydrogenation of Alcohols
Authors: von Wolff Niklas , Rivada‐Wheelaghan Orestes , Tocqueville Damien
Published: July 2021

The development of safe and energy efficient redox processes is key for a future sustainable organic chemistry and energy storage/vector applications. Molecular electrocatalysts have demonstrated their potential in the realm of CO2 reduction, however, successful implementations for the reduction of other carbonyl groups remain sporadic. Building on the reversibility of hydrogenation and dehydrogenation of carbonyls and alcohols, an overview of current molecular electrocatalytic systems is presented. Key mechanistic concepts are emphasized to facilitate the link with more mature schemes in transfer hydrogenation, proton‐ and CO2‐reduction. Thus, this work contributes to future catalyst generation development bridging fundamental aspects of electrochemical bond activation with molecular catalytic concepts in the context of societal challenges of today.
Genetic Algorithm‐Based Improvement to Equivalent Circuit Analysis of Experimental Data in Electrochemical Impedance Spectroscopy
Authors: Kowski Marek , Palys Marcin J.
Published: July 2021

The paper discusses implementation of a hybrid algorithm for the optimization of equivalent circuit (EQC) parameters in the processing of electrochemical impedance data. Similar to other works, we use the genetic algorithm (GA) to find approximate values of parameters, which are further refined by a complex nonlinear least squares (CNLS) method, e. g. Levenberg‐Marquardt. This removes the important drawback of CNLS: the need to supply optimized starting values that are close to optimal ones. We propose the sequence of GA operations and values of GA parameters. In comparison to other works, our algorithm is designed to simplify connection of its GA part to existing CNLS procedures in electrochemical software packages. The algorithm was tested with datasets generated for both simple and complex EQCs, with and without added noise. No starting values were needed and the allowed ranges for EQC parameter variations were broader than found in usual experimental practice. For GA population as small as 300 individuals and the limit of only 500 GA cycles, more than 85 % of runs were successful, while in many cases the success rate was 100 %, also for smaller populations.
Wireless Anodization of Ti in Closed Bipolar Cells
Authors: Sopha Hanna , Rodriguez‐Pereira Jhonatan , Cicmancova Veronika , Macak Jan M.
Published: July 2021

In this work, the anodization of Ti foils in closed bipolar cells is shown for the first time. Depending on the applied potential, i. e. direct or alternating potential, TiO2 nanotube (TNT) layers can either be prepared on one side or on both sides of a Ti foil. It is shown that due to the use of closed bipolar cells, potentials with different amplitudes can be applied within the individual two half‐cells. Additionally, different electrolytes can be used for the anodization of the two sides of a Ti substrate. Thus, the TNT layers obtained under alternating potential on both sides of a Ti foil can have completely different dimensions, i. e. TNT diameter and TNT layer thickness. Furthermore, by employing alternating potentials, black TNT layers can be synthesized on the side of the Ti foil, while being reduced during the last anodization step at negative potentials.
Deep chemometrics: Validation and transfer of a global deep near‐infrared fruit model to use it on a new portable instrument
Authors: Mishra Puneet , Passos Dário
Published: July 2021

Recently, a large near‐infrared spectroscopy data set for mango fruit quality assessment was made available online. Based on that data, a deep learning (DL) model outperformed all major chemometrics and machine learning approaches. However, in earlier studies, the model validation was limited to the test set from the same data set which was measured with the same instrument on samples from a similar origin. From a DL perspective, once a model is trained it is expected to generalise well when applied to a new batch of data. Hence, this study aims to validate the generalisability performance of the earlier developed DL model related to DM prediction in mango on a different test set measured in a local laboratory setting, with a different instrument. At first, the performance of the old DL model was presented. Later, a new DL model was crafted to cover the seasonal variability related to fruit harvest season. Finally, a DL model transfer method was performed to use the model on a new instrument. The direct application of the old DL model led to a higher error compared to the PLS model. However, the performance of the DL model was improved drastically when it was tuned to cover the seasonal variability. The updated DL model performed the best compared to the implementation of a new PLS model or updating the existing PLS model. A final root‐mean‐square error prediction (RMSEP) of 0.518% was reached. This result supports that, in the availability of large data sets, DL modelling can outperform chemometrics approaches.
Phosphine‐Stabilized Pnictinidenes
Authors: Raiser Dominik , Eichele Klaus , Schubert Hartmut , Wesemann Lars
Published: July 2021

The reaction of the intramolecular germylene‐phosphine Lewis pair (o‐PPh2)C6H4GeAr* (1) with Group 15 element trichlorides ECl3 (E=P, As, Sb) was investigated. After oxidative addition, the resulting compounds (o‐PPh2)C6H4(Ar*)Ge(Cl)ECl2 (2: E=P, 3: E=As, 4: E=Sb) were reduced by using sodium metal or LiHBEt3. The molecular structures of the phosphine‐stabilized phosphinidene (o‐PPh2)C6H4(Ar*)Ge(Cl)P (5), arsinidene (o‐PPh2)C6H4(Ar*)Ge(Cl)As (6) and stibinidene (o‐PPh2)C6H4(Ar*)Ge(Cl)Sb (7) are presented; they feature a two‐coordinate low‐valent Group 15 element. After chloride abstraction, a cyclic germaphosphene [(o‐PPh2)C6H4(Ar*)GeP] [B(C6H3(CF3)2)4] (8) was isolated. The 31P NMR data of the germaphosphene were compared with literature examples and analyzed by quantum chemical calculations. The phosphinidene was treated with [iBu2AlH]2, and the product of an Al−H addition to the low‐valent phosphorus atom (o‐PPh2)C6H4(Ar*)Ge(H)P(H)Al(C4H9)2 (9) was characterized.
Model selection properties of forward selection and sequential cross‐validation for high‐dimensional regression
Authors: Wieczorek Jerzy , Lei Jing
Published: July 2021

Forward selection (FS) is a popular variable selection method for linear regression. But theoretical understanding of FS with a diverging number of covariates is still limited. We derive sufficient conditions for FS to attain model selection consistency. Our conditions are similar to those for orthogonal matching pursuit, but are obtained using a different argument. When the true model size is unknown, we derive sufficient conditions for model selection consistency of FS with a data‐driven stopping rule, based on a sequential variant of cross‐validation. As a byproduct of our proofs, we also have a sharp (sufficient and almost necessary) condition for model selection consistency of “wrapper” forward search for linear regression. We illustrate intuition and demonstrate performance of our methods using simulation studies and real datasets.
Exploring the Microbial Ecological Functions in Response to Vertical Gradients in a Polluted Urban River
Authors: Cai Wei , Li Yi , Hu Jian , Cheng Haomiao
Published: July 2021

Sharp vertical environmental gradients could differentially affect the structure and function of microbes. Here, the authors provide some of the first insights into the vertical distribution of microbial functions in a polluted urban river using Geochip 5.0 microarray. A total of 89 615 functional genes belonging to 1213 categories are detected in Jinchuan River in China. Genes involved in metal homeostasis, stress response, carbon cycling, antibiotic resistance, and organic contaminant degradation are the primary gene categories detected and comprise 24.63%, 15.20%, 14.17%, 10.59%, and 8.03% of total genes. There are no significant differences in the abundance of functional gene groups at varying depths. Different gene categories showed small fluctuations in their metabolic potentials at varying depths. Functional gene diversity in bottom water and sediment layers is higher than in surface layers. Additionally, functional potentials of antibiotic resistance, organic contaminant degradation, and pigment genes are stronger in water than in sediment, while those of nitrogen cycling and microbial defense increased with depth. The surface sediment layer and surface water layer have the greatest metabolic potential for the carbon cycle and organic pollutant degradation processes, respectively. The middle sediment layer has the highest potential for the nitrogen and phosphorus cycles.