bluuebunny/crossref_metadata_2025 huggingface dataset:
Tunable Grain Boundary of Lead‐Free All‐Inorganic Perovskite Films for Smart Photodetectors
Authors: Liu Dong , Zhang Kangning , Liu Fengjing , Yin Yanxue , Feng Xiao , Miao Chengcheng , Chen Ming , Zhuang Xinming , Hao Xiaotao , Yang Zai‐xing
Published: October 2021

The nonradiative recombination caused by the trap states at the grain boundaries (GBs) and surfaces directly limits the photoelectronic performance of lead‐free all‐inorganic perovskites films. In this work, the typical CsSnBr3 films with controlled GBs and surfaces are prepared successfully on glass by a solid‐source chemical vapor deposition method. The grain size of CsSnBr3 films increases with the increase of growth temperature, indicating the reduction of GBs. Time‐resolved photoluminescence spectra show that the lifetime of photogenerated carrier is longer in the large‐grain‐size CsSnBr3 film. Furthermore, the photodetector based on CsSnBr3 film with decreased GBs shows excellent performance with photocurrent up to 760 nA, responsivity up to 9200 mA W−1, and fast response times of 5/12 ms under the illumination of 405 nm laser. Moreover, the photodetector is also fabricated on a flexible substrate, demonstrating a good bending stability. This work provides a guideline in the growth of high‐quality perovskites films with controlled GBs and surfaces for next‐generation high‐performance photoelectronic devices.
Direct Nonoxidative Methane Conversion in an Autothermal Hydrogen‐Permeable Membrane Reactor
Authors: Sakbodin Mann , Schulman Emily , Cheng Sichao , Huang Yi‐Lin , Pan Ying , Albertus Paul , Wachsman Eric D. , Liu Dongxia
Published: October 2021

Direct nonoxidative methane conversion (DNMC) transforms CH4 to higher (C2+) hydrocarbons and H2 in a single step, but its utility is challenged by low CH4 equilibrium conversion, carbon deposition (coking), and its endothermic reaction energy requirement. This work reports a heat‐exchanged autothermal H2‐permeable tubular membrane reactor composed of a thin mixed ionic‐electronic conducting SrCe0.7Zr0.2Eu0.1O3–δ membrane supported on a porous SrCe0.8Zr0.2O3–δ tube in which a Fe/SiO2 DNMC catalyst is packed, that concurrently tackles all of these challenges. The H2‐permeation flux drives CH4 conversion. O2 from an air simulant (O2/He mixture) sweep outside the membrane reacts with permeated H2 to provide heat for the endothermic DNMC reaction. The energy balance between the endothermic DNMC and exothermic H2 combustion on opposite sides of the membrane is achieved, demonstrating the feasibility for autothermal operation using a simple air sweep gas. Moreover, the back diffusion of O2 from the sweep side to the catalyst side oxidizes any deposited carbon into CO. Thus, for the first time demonstrating all the desired attributes, a heat‐exchanged H2‐permeable membrane reactor capable of achieving single‐step auto‐thermal DNMC catalysis while simultaneously improving CH4 conversion and preventing coking is achieved.
Awakening the Photoelectrochemical Activity of α‐SnWO4 Photoanodes with Extraordinary Crystallinity Induced by Reductive Annealing
Authors: Liu Deyu , Chen Xiuyu , Qiao Yuepeng , Zhou Yang , Kuang Yongbo
Published: October 2021

Oxide‐based photoelectrodes for solar water splitting have gained growing attention because of their decent stability and cost‐effectiveness. Particularly, α‐SnWO4 has been regarded as a potential next‐generation light absorbing material due to the predicted favorable bandgap of 1.9 eV. Herein, the investigation and amelioration of the crystallinity as a performance dominating factor to the α‐SnWO4‐based photoanode are demonstrated. The improvement is attributed to a unique crystallization process induced by the formation of oxygen vacancies in the reductive atmosphere at 500 °C. The sample exhibits notably enhanced visible‐light absorption and an improved charge transport property. Electrochemical measurements reveal a cathodic shift of the flat‐band potential, corresponding to the impacted band position. The photocurrent is enhanced from 0.03 to 0.42 mA cm−2 (AM1.5, 1.23 VRHE). Such a new treatment can be used as an effective tool for developing α‐SnWO4 into efficient photoelectrocatalytic (PEC) materials.
Retrospective assessment of the association between noise exposure and nonfatal and fatal injury rates among miners in the United States from 1983 to 2014
Authors: Shkembi Abas , Smith Lauren M. , Neitzel Richard L.
Published: October 2021

Background

Mining is a significant economic force in the United States but has historically had among the highest nonfatal injury rates across all industries. Several factors, including workplace hazards and psychosocial stressors, may increase injury and fatality risk. Mining is one of the noisiest industries; however, the association between injury risk and noise exposure has not been evaluated in this industry. In this ecological study, we assessed the association between noise exposure and nonfatal and fatal occupational injury rates among miners.

Methods

Federal US mining accident, injury, and illness data sets from 1983 to 2014 were combined with federal quarterly mining employment and production reports to quantify annual industry rates of nonfatal injuries and fatalities. An existing job‐exposure matrix for occupational noise was used to estimate annual industry time‐weighted average (TWA, dBA) exposures. Negative binomial models were used to assess relationships between noise, hearing conservation program (HCP) regulation changes in 2000, year, and mine type with incidence rates of injuries and fatalities.

Results

Noise, HCP regulation changes, and mine type were each independently associated with nonfatal injuries and fatalities. In multivariate analysis, each doubling (5 dB increase) of TWA was associated with 1.08 (95% confidence interval: 1.05, 1.11) and 1.48 (1.23, 1.78) times higher rate of nonfatal injuries and fatalities, respectively. HCP regulation changes were associated with 0.61 (0.54, 0.70) and 0.49 (0.34, 0.71) times lower nonfatal injury and fatality rates, respectively.

Conclusion

Noise may be a significant independent risk factor for injuries and fatalities in mining.
Ivacaftor restores delayed mucociliary transport caused by Pseudomonas aeruginosa–induced acquired cystic fibrosis transmembrane conductance regulator dysfunction in rabbit nasal epithelia
Authors: Cho Do‐Yeon , Zhang Shaoyan , Skinner Daniel F. , Lim Dong Jin , Banks Catherine , Grayson Jessica W. , Tearney Guillermo J. , Rowe Steven M. , Woodworth Bradford A.
Published: October 2021

Background

Abnormal chloride (Cl–) transport dehydrates airway surface liquid (ASL) in sinonasal epithelium leading to mucus stasis and chronic rhinosinusitis. As an experimental epithelium, rabbit tissue provides an excellent representation of human sinus disease, and the rabbit sinusitis model is both established and well suited for therapeutic interventions in vivo. Our objective in this study was to evaluate whether ivacaftor reverses the consequences of Pseudomonas aeruginosa–induced acquired cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction.

Methods

Rabbit nasal cavities were assessed for responsiveness to ivacaftor in vivo (by nasal potential difference [NPD] assay). Rabbit nasal epithelial (RNE) cultures were incubated with an ultrafiltrate of P aeruginosa (PAO1 strain) for 4 hours and tested for acquired CFTR dysfunction. Markers of mucociliary function, including airway surface liquid depth (ASL), periciliary liquid depth (PCL), ciliary beat frequency (CBF), and mucociliary transport (MCT), were measured by micro‐optical coherence tomography (μOCT) after PAO1 and/or ivacaftor incubation.

Results

Ivacaftor resulted in a significant mean NPD polarization of 21.8 ± 2.1 mV, which was significantly greater than that seen in the low Cl− control (12.9 ± 1.3; p = 0.01). PAO1 exposure induced a state of acquired CFTR dysfunction in rabbit nasal epithelium as measured by forskolin‐stimulated short‐circuit current (ISC) (control, 37.0 ± 1.1 μA/cm2; PAO1, 24.4 ± 1.1 μA/cm2; p < 0.001). RNE cultures exposed to PAO1 had inhibited mucociliary function, whereas coincubation with ivacaftor restored mucociliary clearance, as measured by μOCT.

Conclusion

In rabbit nasal epithelium, ivacaftor robustly stimulates CFTR‐mediated Cl− secretion and normalizes ASL and CBF in PAO1‐induced acquired CFTR dysfunction. Preclinical testing of CFTR potentiators as therapy for P aeruginosa rabbit sinusitis is planned.
Determinants of survival in sinonasal and skull base chondrosarcoma: An analysis of the National Cancer Database
Authors: Rimmer Ryan A. , Mace Jess C. , Andersen Peter E. , Cetas Justin S. , Ciporen Jeremy N. , Dogan Aclan , Smith Timothy L. , Geltzeiler Mathew
Published: October 2021

Background

Chondrosarcomas are rare, malignant chondroid tumors that can occur in the sinonasal and skull base regions. Surgery is a mainstay of treatment, but complete resection can be challenging because of the close proximity of critical neurovascular structures. Because of their rarity and relatively indolent nature, optimal treatment regimens are not established. Our objective was to assess determinants of survival for sinonasal and skull base chondrosarcomas utilizing the National Cancer Database (NCDB).

Methods

The NCDB (2004–2017) was queried for cases of sinonasal and skull base chondrosarcoma. Multivariate hazard regression modeling was used to identify significant predictors of 60‐month and 120‐month overall survival (OS).

Results

Seven hundred thirty‐six cases met inclusion criteria. OS for all treatment types was 84.7% [SE±0.02] at 60 months and 75.6% [SE±0.02] at 120 months. Surgery with or without adjuvant treatment was found to associate with highest OS at 60 and 120 months. For patients receiving adjuvant radiation during treatment, proton therapy had significantly better OS at 60 months (95.4% [SE±0.03] vs 82.3% [SE±0.03], ‐2 = 5.27; p = 0.02) and 120 months (85.1% [SE±0.08] vs 72.8% [SE±0.05], ‐2 = 4.11; p = 0.04) compared with conventional external beam. After adjustment for primary site, multivariate Cox regression modeling (n = 561) identified cofactors significantly associated with variation in mortality risk at 60 and 120 months, including age, Charlson‐Deyo total score ≥ 3, insurance provision status, and tumor grade.

Conclusions

Sinonasal and skull base chondrosarcoma are primarily treated with surgery with favorable OS. Adjuvant treatment may be required and proton radiation was associated with improved 60‐month and 120‐month survival compared with conventional radiation.
Electrophilic Activation of [1.1.1]Propellane for the Synthesis of Nitrogen‐Substituted Bicyclo[1.1.1]pentanes
Authors: Livesley Sarah , Sterling Alistair J. , Robertson Craig M. , Goundry William R. F. , Morris James A. , Duarte Fernanda , Aïssa Christophe
Published: October 2021

Strategies commonly used for the synthesis of functionalised bicyclo[1.1.1]pentanes (BCP) rely on the reaction of [1.1.1]propellane with anionic or radical intermediates. In contrast, electrophilic activation has remained a considerable challenge due to the facile decomposition of BCP cations, which has severely limited the applications of this strategy. Herein, we report the electrophilic activation of [1.1.1]propellane in a halogen bond complex, which enables its reaction with electron‐neutral nucleophiles such as anilines and azoles to give nitrogen‐substituted BCPs that are prominent motifs in drug discovery. A detailed computational analysis indicates that the key halogen bonding interaction promotes nucleophilic attack without sacrificing cage stabilisation. Overall, our work rehabilitates electrophilic activation of [1.1.1]propellane as a valuable strategy for accessing functionalised BCPs.
Ein Designeraußenmembranprotein fördert die Aufnahme von Täuschmolekülen in einen auf Zytochrom P450BM3 beruhenden Ganzzellbiokatalysator
Authors: Karasawa Masayuki , Yonemura Kai , Stanfield Joshua Kyle , Suzuki Kazuto , Shoji Osami
Published: October 2021

Wir berichten über eine OmpF‐Schleifenlöschungsmutante, welche die Zellaufnahme externer Additiva in einen Escherichia‐coli‐Ganzzellbiokatalysator verbessert. Durch die Koexprimierung der OmpF‐Mutante mit Wildtyp‐P450BM3 in Gegenwart von Täuschmolekülen konnte die Ausbeute der Ganzzellbiotransformation Benzols erheblich gesteigert werden. Insbesondere mit dem Täuschmolekül C7AM‐Pip‐Phe verzwölffachte sich die Ausbeute von 5.7 % auf 70 % mit einer Phenolselektivität von 80 %. Die Untersuchung der benzylischen Hydroxylierung von Alkyl‐ und Zykloalkylbenzolen ergab, dass mit Hilfe von Täuschmolekülen Propylbenzol und Tetralin jeweils mit 78 % Ausbeute und einer Selektivität von 94 % (R) ee für Propylbenzol and 92 % Ausbeute und einer Selektivität von 94 % (S) ee für Tetralin in ihre 1‐Hydroxylierungsprodukte überführt wurden. Unsere Ergebnisse deuten darauf hin, dass sowohl das Täuschmolekül als auch das Substrat den künstlichen OmpF‐Kanal durchqueren und dadurch die Ganzzellbiotransformation in ganzen Zellen synergetisch verstärken.
Re‐imagining Priorities for Chemistry: A Central Science for “Freedom from Fear and Want”
Authors: Matlin Stephen A. , Krief Alain , Hopf Henning , Mehta Goverdhan
Published: October 2021

Human security, defined as “freedom from want and fear and freedom to live in dignity”, provides an overarching concept to address threats to human security dimensions such as health, food, economics, the environment and sustainable development, while placing the individual at the centre of attention. Chemistry is central to addressing these challenges, but surprisingly its role and contributions to human security have hitherto not been explicitly set out. This article situates chemistry in the human security framework, highlighting areas where chemistry knowledge, methods and products are vital. It underscores three complementary facets: 1) chemistry contributes to many dimensions of human security, but needs to do much more in the light of oncoming global challenges; 2) the human security framing illuminates areas where chemistry itself needs to adapt to contribute better, by intensification of current approaches and/or by building or strengthening chemistry tools, skills and competencies; and 3) repositioning as central to human security affords chemistry a powerful opportunity to refresh itself as a science for the benefit of society—and it will need to engage more directly and dynamically at the interface of science, society and policy in order to do so.
Bulk Electrocatalytic NADH Cofactor Regeneration with Bipolar Electrochemistry
Authors: Zhang Chunhua , Zhang Huiting , Pi Junying , Zhang Lin , Kuhn Alexander
Published: October 2021

Electrochemical regeneration of reduced nicotinamide adenine dinucleotide (NADH) is an extremely important challenge for the electroenzymatic synthesis of many valuable chemicals. Although some important progress has been made with modified electrodes concerning the reduction of NAD+, the scale‐up is difficult due to mass transport limitations inherent to large‐size electrodes. Here, we propose instead to employ a dispersion of electrocatalytically active modified microparticles in the bulk of a bipolar electrochemical cell. In this way, redox reactions occur simultaneously on all of these individual microelectrodes without the need of a direct electrical connection. The concept is validated by using [Rh(Cp*)(bpy)Cl]+ functionalized surfaces, either of carbon felt as a reference material, or carbon microbeads acting as bipolar objects. In the latter case, enzymatically active 1,4‐NADH is electroregenerated at the negatively polarized face of the particles. The efficiency of the system can be fine‐tuned by controlling the electric field in the reaction compartment and the number of dispersed microelectrodes. This wireless bioelectrocatalytic approach opens up very interesting perspectives for electroenzymatic synthesis in the bulk phase.
Ultrahigh Supramolecular Cascaded Room‐Temperature Phosphorescence Capturing System
Authors: Huo Man , Dai Xian‐Yin , Liu Yu
Published: October 2021

An ultrahigh supramolecular cascaded phosphorescence‐capturing aggregate was constructed by multivalent co‐assembly of cucurbit[7]uril (CB[7]) and amphipathic sulfonatocalix[4]arene (SC4AD). The initial dibromophthalimide derivative (G) generated a weak phosphorescent emission at 505 nm by host–guest interaction with CB[7], which further assembled with SC4AD to form homogeneously spherical nanoparticles with a dramatic enhancement of both phosphorescence lifetime to 1.13 ms and emission intensity by 40‐fold. Notably, this G⊂CB[7]@SC4AD aggregate exhibited efficient phosphorescence energy transfer to Rhodamine B (RhB) and benzothiadiazole (DBT) with high efficiency (ϕET) of 84.4 % and 76.3 % and an antenna effect (AE) of 289.4 and 119.5, respectively, and then each of these can function as a bridge to further transfer their energy to second near‐IR acceptors Cy5 or Nile blue (NiB) to achieve cascaded phosphorescence energy transfer. The final aggregate with long‐range effect from 425 nm to 800 nm and long‐lived photoluminescence was further employed as an imaging agent for multicolour cell labeling.
Metal‐Triazolate‐Framework‐Derived FeN4Cl1 Single‐Atom Catalysts with Hierarchical Porosity for the Oxygen Reduction Reaction
Authors: Hu Linyu , Dai Chunlong , Chen Liwei , Zhu Yuhao , Hao Yuchen , Zhang Qinghua , Gu Lin , Feng Xiao , Yuan Shuai , Wang Lu , Wang Bo
Published: October 2021

The construction of single‐atom catalysts (SACs) with high single atom densities, favorable electronic structures and fast mass transfer is highly desired. We have utilized metal‐triazolate (MET) frameworks, a subclass of metal–organic frameworks (MOFs) with high N content, as precursors since they can enhance the density and regulate the electronic structure of single‐atom sites, as well as generate abundant mesopores simultaneously. Fe single atoms dispersed in a hierarchically porous N‐doped carbon matrix with high metal content (2.78 wt %) and a FeN4Cl1 configuration (FeN4Cl1/NC), as well as mesopores with a pore:volume ratio of 0.92, were obtained via the pyrolysis of a Zn/Fe‐bimetallic MET modified with 4,5‐dichloroimidazole. FeN4Cl1/NC exhibits excellent oxygen reduction reaction (ORR) activity in both alkaline and acidic electrolytes. Density functional theory calculations confirm that Cl can optimize the adsorption free energy of Fe sites to *OH, thereby promoting the ORR process. The catalyst demonstrates great potential in zinc‐air batteries. This strategy selects, designs, and adjusts MOFs as precursors for high‐performance SACs.
Monometallic and heterobimetallic ruthenium (II) and palladium (II) complexes based on a pyridine‐hydrazone ligand as bifunctional catalysts for ROMP of norbornene and ethylene polymerization
Authors: Gois Patrik Dione de Santana , Maia Juliana Iris Pereira , Masson Gustavo Henrique Cicero , Martins Daniele Maria , Machado Antonio Eduardo da Hora , Goi Beatriz Eleutério , Maia Pedro Ivo da Silva , Carvalho‐Jr Valdemiro Pereira de
Published: October 2021

The monometallic complex [Pd(L)(PPh3)] (mono‐Pd) was synthesized using a potentially tridentate hydrazone (H2L) and used as precursor to prepare a heterobimetallic ruthenium (II)‐palladium (II) complex [Cl2(p‐cymene)Ru(μ‐L)Pd (PPh3)] (Ru‐Pd). Mono‐Pd and Ru‐Pd were characterized by fourier transform infrared spectroscopy (FTIR), ultraviolet‐visible spectroscopy (UV–Vis), 1H, 13C{1H} and 31P{1H} nuclear magnetic ressonance(NMR) spectroscopy, elemental analysis, cyclic voltammetry, matrix‐assisted laser desorption/ionization ‐ time of flight (MALDI‐TOF) mass spectrometry, and computational methods. The mono‐Pd was additionally studied by single‐crystal X‐ray diffraction. The complex [RuCl2(p‐cymene)(Isoniazid)] (mono‐Ru) was also obtained following literature methods aiming a comparison in the catalytic activity. The ring opening metathesis polymerization (ROMP) of norbornene (NBE) using mono‐Ru or Ru‐Pd as precatalysts in the presence of ethyl diazoacetate (EDA) was evaluated as a function of time (10–60 min) using [NBE]/[EDA]/[Ru] = 5000/28/1 at 50°C. The time increases produced good yields of polyNBE, reaching 38% and 46% for mono‐Ru and Ru‐Pd, respectively. The polyNBE produced was measured by size‐exclusion chromatography (SEC) and reached an order of magnitude of 105 g·mol−1 of Mn, with Ð values ranging from 2.51 to 1.86 for mono‐Ru and from 3.50 to 1.66 for Ru‐Pd. The catalytic activity of mono‐Pd and Ru‐Pd on ethylene polymerization was assessed with a range of [Al]/[Pd] molar ratio between 350 and 1750, 30–70°C temperature, 2 to 4 h reaction time, and total reaction volume of 25 and 50 ml. Mono‐Pd achieved an activity of 22.80 kg PE (mol Pd)−1 h−1 at 60°C after 4 h using [Al]/[Pd] = 1050, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. For Ru‐Pd, an activity of 20.35 kg PE (mol Pd)−1 h−1 at 60°C after 4 h was obtained using [Al]/[Pd] = 1750, 7 μmol of catalyst in 25 ml of toluene, and 116 psi ethylene. Overall, Ru‐Pd showed to be active in both ROMP and ethylene polymerization reactions, being categorized as a bifunctional catalyst.
Mixed Alkyl/Aryl Diphos Ligands for Iron‐Catalyzed Negishi and Kumada Cross Coupling Towards the Synthesis of Diarylmethane
Authors: Ma Xufeng , Wang Han , Liu Yao , Zhao Xing , Zhang Jun
Published: October 2021

Mixed alkyl/aryl diphos ligands have been prepared and their application in iron‐catalyzed cross coupling of benzylic chlorides with diaryl zinc (Negishi) or aryl Grignard reagents (Kumada) towards the synthesis of diarylmethane has been evaluated. The iron−diphos catalytic system exhibited the enhanced activity and selectivity in the two coupling reactions. The electron‐rich mixed PPh2/PCy2ligands outperformed their symmetrical PPh2congeners, and led to decreased homocoupling byproduct formation. It indicates that the electronic effect of the ligands plays an important role in the catalytic performance. The Fe catalyst supported byL8bearing an electron‐rich PCy2substituent and a sterically demanding tert‐butyl on ethene backbone exhibited the best catalytic performance and good functional group tolerance in the two cross coupling reactions.
Progress of Solid‐state Electrolytes Used in Organic Secondary Batteries
Authors: Wang Shaolong , Lv Jing , Wang Xuehan , Cui Haixia , Huang Weiwei , Wang Yanzhi
Published: October 2021

Organic electrode materials (OEMs) have attracted intensive attention owing to their high energy density, diverse structures and environmental friendliness. Unfortunately, the easy dissolution of OEMs in the organic liquid electrolytes (OLEs) severely damages the cycle stability of batteries. There is a hidden danger of catching fire due to a lot of heat generated from overcharge of the batteries. Moreover, OLEs are liable to leak and unstable at high voltage. Using solid‐state electrolytes (SSEs) could effectively alleviate the above‐mentioned problems at some extent. However, SSEs still show some weaknesses, including the large impedance of electrolyte‐electrode interface (EEI) and low ion conductivity. In this review, the latest progress in the research of SSEs used in organic secondary batteries (OSBs) are summarized, with particularly focus on the ionic conductivity of SSEs, the combination of organic electrodes/solid‐state electrolytes, the optimization of EEI and the batteries cycle stability. Future directions for the development of OSBs are given from viewpoints of solid batteries.
Immobilized Poly(anthraquinones) for Electrochemical Energy Storage Applications: Structure‐Property Relations
Authors: Wielend Dominik , Salinas Yolanda , Mayr Felix , Bechmann Matthias , Yumusak Cigdem , Neugebauer Helmut , Brüggemann Oliver , Sariciftci Niyazi Serdar
Published: October 2021

The majority of energy storage devices like batteries, fuel cells or electrolyzers require heterogeneous electrodes. Immobilization of redox‐active organic molecules by a polymeric approach seems to be a promising route towards organic electrodes for electrocatalytic energy storage or in batteries. Although numerous reports on synthesis and application of new poly‐anthraquinones exist, a universal guideline or tool for selection of the best polymer, concerning several energy storage applications, is still underdeveloped. Moving into the direction of developing such a tool, we have selected and synthesized three poly(anthraquinones). NMR, FTIR, UV‐Vis, TGA, contact angle measurement and SEM revealed certain structure‐property trends, which can be correlated with the performance in the electrochemical investigation. The insights gained within this work demonstrate correlations between the FTIR frequencies and the electrochemical reduction potential, as well as between the polymer hydrophobicity and the electrochemical performance.
Highly Efficient Thermally Activated Delayed Fluorescence from Pyrazine‐Fused Carbene Au(I) Emitters
Authors: Yang Jian‐Gong , Song Xiu‐Fang , Wang Jian , Li Kai , Chang Xiaoyong , Tan Li‐Ying , Liu Chu‐Xuan , Yu Fei‐Hu , Cui Ganglong , Cheng Gang , To Wai‐Pong , Yang Chuluo , Che Chi‐Ming , Chen Yong
Published: October 2021

Metal‐based thermally activated delayed fluorescence (TADF) is conceived to inherit the advantages of both phosphorescent metal complexes and purely organic TADF compounds for high‐performance electroluminescence. Herein a panel of new TADF Au(I) emitters has been designed and synthesized by using carbazole and pyrazine‐fused nitrogen‐heterocyclic carbene (NHC) as the donor and acceptor ligands, respectively. Single‐crystal X‐ray structures show linear molecular shape and coplanar arrangement of the donor and acceptor with small dihedral angles of <6.5°. The coplanar orientation and appropriate separation of the HOMO and LUMO in this type of molecules favour the formation of charge‐transfer excited state with appreciable oscillator strength. Together with a minor but essential heavy atom effect of Au ion, the complexes in doped films exhibit highly efficient (Φ∼0.9) and short‐lived (<1 μs) green emissions via TADF. Computational studies on this class of emitters have been performed to decipher the key reverse intersystem crossing (RISC) pathway. In addition to a small energy splitting between the lowest singlet and triplet excited states (ΔEST), the spin‐orbit coupling (SOC) effect is found to be larger at a specific torsion angle between the donor and acceptor planes which favours the RISC process the most. This work provides an alternative molecular design to TADF Au(I) carbene emitters for OLED application.
Versatile Para‐Substituted Pyridine Lanthanide Coordination Complexes Allow Late Stage Tailoring of Complex Function
Authors: Starck Matthieu , Fradgley Jack D. , De Rosa Davide F. , Batsanov Andrei S. , Papa Maria , Taylor Michael J. , Lovett Janet E. , Lutter Jacob C. , Allen Matthew J. , Parker David
Published: October 2021

A series of cationic and neutral p−Br and p−NO2 pyridine substituted Eu(III) and Gd(III) coordination complexes serve as versatile synthetic intermediates. Nucleophilic aromatic substitution occurs readily at the para position under mild conditions, allowing C−N and C−C bond forming reactions to take place, permitting the introduction of azide, amino and alkynyl substituents. For Eu(III) complexes, this approach allows late stage tuning of absorption and emission spectral properties, exemplified by the lowering of the energy of an LMCT transition accompanied by a reduction in the Eu−Npy bond length. Additionally, these complexes provide direct access to the corresponding Eu(II) analogues. With the Gd(III) series, the nature of the p‐substituent does not significantly change the EPR properties (linewidth, relaxation times), as required for their development as EPR spin probes that can be readily conjugated to biomolecules under mild conditions.
Real‐time Voltammetric Anion Sensing Under Flow**
Authors: Patrick Sophie C. , Hein Robert , Sharafeldin Mohamed , Li Xiaoxiong , Beer Paul D. , Davis Jason J.
Published: October 2021

The development of real‐life applicable ion sensors, in particular those capable of repeat use and long‐term monitoring, remains a formidable challenge. Herein, we demonstrate, in a proof‐of‐concept, the real‐time voltammetric sensing of anions under continuous flow in a 3D‐printed microfluidic system. Electro‐active anion receptive halogen bonding (XB) and hydrogen bonding (HB) ferrocene‐isophthalamide‐(iodo)triazole films were employed as exemplary sensory interfaces. Upon exposure to anions, the cathodic perturbations of the ferrocene redox‐transducer are monitored by repeat square‐wave voltammetry (SWV) cycling and peak fitting of the voltammograms by a custom‐written MATLAB script. This enables the facile and automated data processing of thousands of SW scans and is associated with an over one order‐of‐magnitude improvement in limits of detection. In addition, this improved analysis enables tuning of the measurement parameters such that high temporal resolution can be achieved. More generally, this new flow methodology is extendable to a variety of other analytes, including cations, and presents an important step towards translation of voltammetric ion sensors from laboratory to real‐world applications.
Electrospun Tungsten‐Polyurethane Composite Nanofiber Mats for Medical Radiation‐Shielding Applications
Authors: Yun Jaehan , Hou Jian , Jang Wongi , Kim Sung‐Yul , Byun Hongsik
Published: October 2021

Electrospun composite nanofiber mats consisting of polyurethane (PU) and nontoxic tungsten powder are manufactured via electrospinning for use as X‐ray shielding materials. Upon systematical formation of tungsten‐PU composite nanofiber layers, heat and pressure are simultaneously treated to design light‐weight mats containing various amount of tungsten metals. After examining their structural and physical properties, the X‐ray mass attenuation coefficient, nitrogen permeability, and flexibility of the resulting mats are compared to conventional film‐type shielding mats. While the nanofiber‐based composite mats still exhibit a comparable X‐ray mass attenuation coefficient (9.64 cm2/g), their gas permeability (8.56 L/min) and flexibility (bending angle of 28.8°) are almost two and five times higher than those of conventional mats, respectively. This work clearly demonstrates the preparation of effective composite mats with controlled properties for the development of nontoxic shielding suits that can replace conventional lead‐based materials possessing environmental and health concerns.
MrFbP: Markov random field‐driven spatial entropy‐based routing protocol in opportunistic networks
Authors: Kumar Arun , Dutta Aniruddha A. , Jain Nayan , Dhurandher Sanjay K.
Published: October 2021

Recently, research towards technologies associated with the 5G communication is in full operation. Amongst these enabling technologies, device‐to‐device(D2D) communication is one of the critical factors for scaling up the network efficiency in 5G communication. Intermittent connections due to higher mobility lead to frequent path breaks, and hence a mobility‐based opportunistic routing is suitable enough to control the forwarding process. Opportunistic networks (OppNet) use the pairwise opportunistic contacts and higher mobility to rely on the store‐carry and forward mechanism for routing purpose. In this work, a novel mobility‐induced context‐based routing process has been designed to support D2D communication. The designed Markov random field‐induced protocol (MrFbP) is based on spatial entropy for capturing the coverage span of the forwarding node in the network. The work relies on the monitored historic mobility of a node and is then used to capture the utility metric for taking forwarding decision. MrFbP is compared against the established Direct Delivery (DD), Epidemic (EP), Spray & Wait (SW), and PropHet (PR) on parameters like throughput, delay, hops, overheads, and energy consumption. Simulation has been carried out using ONE simulator to validate an improvement in the design of a designed protocol against the baseline protocols.
Applying deep neural networks to predict incidence and phenology of plant pests and diseases
Authors: Grünig Marc , Razavi Elisabeth , Calanca Pierluigi , Mazzi Dominique , Wegner Jan Dirk , Pellissier Loïc
Published: October 2021

A major challenge of agriculture is to improve the sustainability of food production systems in order to provide enough food for a growing human population. Pests and pathogens cause vast yield losses, while crop protection practices raise environmental and human health concerns. Decision support systems provide detailed information on optimal timing and necessity of crop protection interventions, but are often based on phenology models that are time‐, cost‐, and labor‐intensive in development. Here, we aim to develop a data‐driven approach for pest damage forecasting, relying on big data and deep learning algorithms. We present a framework for the development of deep neural networks for pest and pathogen damage classification and show their potential for predicting the phenology of damages. As a case study, we investigate the phenology of the pear leaf blister moth (Leucoptera malifoliella, Costa). We employ a set of 52,322 pictures taken during a period of 19 weeks and establish deep neural networks to categorize the images into six main damage classes. Classification tools achieved good performance scores overall, with differences between the classes indicating that the performance of deep neural networks depends on the similarity to other damages and the number of training images. The reconstructed damage phenology of the pear leaf blister moth matches mine counts in the field. We further develop statistical models to reconstruct the phenology of damages with meteorological data and find good agreement with degree‐day models. Hence, our study indicates a yet underexploited potential for data‐driven approaches to enhance the versatility and cost efficiency of plant pest and disease forecasting.
Mutual cheating strengthens a tropical seed dispersal mutualism
Authors: Cao Lin , Jansen Patrick A. , Wang Bo , Yan Chuan , Wang Zhenyu , Chen Jin
Published: October 2021

While cheating can cause the degradation or collapse of mutualisms, mutualisms may theoretically stabilize or strengthen if the cheating is mutual. Here, we present an asymmetric two‐player game model to explore the evolutionary dynamics of mutual cheating in a mutualistic interaction. We found that the interaction evolved toward mutual cheating if cheating can help both partners obtain higher benefits or if counter‐cheating yields more benefits to victims than simply tolerating exploitation by partners. Then, we present empirical evidence for such mutual cheating strengthening a seed dispersal mutualism in which rodents disperse seeds by scatter hoarding, rodents sabotage seed germination by pruning radicles, and seeds escape rodents by resprouting. By tracking >8,000 Pittosporopsis kerrii seeds throughout the dispersal process in a tropical forest in southwest China, we found that rodents provided better dispersal to seeds that they pruned, i.e., pruned seeds were dispersed farther and were more likely to establish seedlings than unpruned seeds. Compared with unpruned seeds, pruned seeds retained more of their nutrients, i.e., dry mass of pruned seeds was greater than that of unpruned seeds, and were stored for longer by rodents. These findings indicate that mutual cheating benefited both partners. Payoffs estimated from the field experiments indicated that mutual cheating was indeed favored in rodents and plants P. kerrii, and that neither partner was enslaved by the other under mutual cheating. Rather, the mutualism remained stable because the partners were able to exploit each other, and each partner attempted to gain the maximum benefits from the interaction. Our findings indicate that mutual cheating between two mutualists can enhance and stabilize mutualisms.
Ring‐Closing Metathesis of Aliphatic Ethers and Esterification of Terpene Alcohols Catalyzed by Functionalized Biochar
Authors: Vidal Juliana L. , Wyper Olivia M. , MacQuarrie Stephanie L. , Kerton Francesca M.
Published: October 2021

Functionalized biochars, renewable carbon materials prepared from waste biomass, can catalyze transformations of a range of oxygen‐containing substrates via hydrogen‐bonding interactions. Good conversions (up to 75.2 %) to different O‐heterocycles are obtained from ring‐closing C−O/C−O metathesis reactions of different aliphatic ethers under optimized conditions using this heterogeneous, metal‐free, and easy separable catalyst. The diversity in the sorts of O‐containing feedstocks is further demonstrated by the utilization of functionalized biochar to promote the esterification of terpene alcohols, an important reaction in food and flavor industries. Under the optimized conditions, full conversions to various terpene esters are obtained. Moreover, both of the reactions studied herein are performed under neat conditions, thus increasing the overall sustainability of the process described.
Small‐Molecular Crowding Electrolyte Enables High‐Voltage and High‐Rate Supercapacitors
Authors: Wang Wenkang , Yang Cheng , Chi Xiaowei , Liu Jiahe , Wen Bo , Liu Yu
Published: October 2021

Aqueous energy storage devices attract increased attention due to their high safety, low cost, and easy maintenance. However, the low energy density caused by the narrow electrochemical stability window (ESW) of aqueous electrolytes severely restricts their widespread applications. Herein, a new type of “small‐molecule crowding” electrolyte of 95EG‐H2O (95 wt% ethylene glycol [EG]) is proposed for the first time. Significant enhancement of water molecular stability is accomplished through the engineering of a hydrogen bond network. The small‐molecular crowding agent (EG) not only expands the ESW to 3.2 V, but also endows the electrolyte with low viscosity. As a proof‐of‐concept device, the symmetry carbon‐based supercapacitor using the newly developed electrolyte exhibits a so far record‐high operating voltage of 2.8 V, a high energy density of 58.7 Wh kg−1 at a power density of 1.4 and 30.3 Wh kg−1 at a power density of 42 kW kg−1, and a durable lifespan exceeding 20 000 cycles at a current density of 5 A g−1.
Tectonic settings of thePlio–Quaternaryvolcanism in Iran from multidimensional and multielement solutions
Authors: Verma Surendra P. , Molaei‐Yeganeh Tahereh
Published: October 2021

Geochemical data for 435 samples of the Pliocene to Quaternary (P–Q) volcanic rocks from Iran, distributed mostly along a NW–SE trending belt, were compiled from 28 papers (12 written in Persian). Until now, the rock nomenclature employed has been inconsistent with the recommendations of the International Union of Geological Sciences (IUGS). Moreover, older bivariate and ternary tectonic discrimination diagrams and only traditional qualitative approaches using Nb and Ta anomalies, have been used to understand the origin and evolution of the P–Q magmas. The P–Q magma and rock types were classified by strictly following the IUGS recommendations. Two geochemometric multidimensional models based on 10 and 16 elements, along with two decision procedures, capable of discriminating 29 fine tectonic settings, were used to document the existence of six tectonic settings in Iran during the P–Q. The rare earth elements indicated that the evolved intermediate and silicic rocks had a significant crustal component in their origin. The quantification of Nb and Ta anomalies in multielement diagrams was used to support the tectonic inferences from the multidimensional geochemometric models.
White matter hyperintensities segmentation using an ensemble of neural networks
Authors: Li Xinxin , Zhao Yu , Jiang Jiyang , Cheng Jian , Zhu Wanlin , Wu Zhenzhou , Jing Jing , Zhang Zhe , Wen Wei , Sachdev Perminder S. , Wang Yongjun , Liu Tao , Li Zixiao
Published: October 2021

White matter hyperintensities (WMHs) represent the most common neuroimaging marker of cerebral small vessel disease (CSVD). The volume and location of WMHs are important clinical measures. We present a pipeline using deep fully convolutional network and ensemble models, combining U‐Net, SE‐Net, and multi‐scale features, to automatically segment WMHs and estimate their volumes and locations. We evaluated our method in two datasets: a clinical routine dataset comprising 60 patients (selected from Chinese National Stroke Registry, CNSR) and a research dataset composed of 60 patients (selected from MICCAI WMH Challenge, MWC). The performance of our pipeline was compared with four freely available methods: LGA, LPA, UBO detector, and U‐Net, in terms of a variety of metrics. Additionally, to access the model generalization ability, another research dataset comprising 40 patients (from Older Australian Twins Study and Sydney Memory and Aging Study, OSM), was selected and tested. The pipeline achieved the best performance in both research dataset and the clinical routine dataset with DSC being significantly higher than other methods (p < .001), reaching .833 and .783, respectively. The results of model generalization ability showed that the model trained on the research dataset (DSC = 0.736) performed higher than that trained on the clinical dataset (DSC = 0.622). Our method outperformed widely used pipelines in WMHs segmentation. This system could generate both image and text outputs for whole brain, lobar and anatomical automatic labeling WMHs. Additionally, software and models of our method are made publicly available at https://www.nitrc.org/projects/what_v1.
Universal oral health coverage – Perspectives from a developing country
Authors: Purohit Bharathi M. , Kharbanda O. P. , Priya Harsh
Published: October 2021

Universal Health Coverage (UHC) is where people have access to health services without suffering financial hardship to pay for it, provide equitable health‐care services that are appropriate, accessible and affordable for all people, particularly poor and disadvantaged communities. However, optimal intervention in relation to oral disease is not universally available or affordable specifically in developing countries because of limited resources at public sector, escalating costs of treatment and inadequate emphasis on primary prevention of oral diseases. Similar barriers also exist in utilisation of dental services among the Indian population. Integrating oral health into UHC will help improve oral health outcomes and reduce inequalities in access to care. To strengthen the oral health system towards UHC, public sector spending on oral health‐care should be equally focused on primary care instead of directing mainly into only tertiary care, which could help reduce the number of complications progress to more expensive and more aggressive treatment.
Denoising of computed tomography using bilateral median based autoencoder network
Authors: Juneja Mamta , Joshi Saasha , Singla Naveen , Ahuja Shaurya , Saini Sumindar Kaur , Thakur Niharika , Jindal Prashant
Published: October 2021

Denoising of Computed tomography (CT) images is a critical aspect of image processing that is expected to improve the performance of Computer‐aided diagnosis (CAD) systems. However, the use of complex imaging modalities such as CT imaging to ascertain pancreatic cancer is vulnerable to gaussian and poisson noises, making image denoising an imperative step for the accurate performance of CAD systems. This paper presents a Bilateral median based autoencoder network (BMAuto‐Net) constructed with intermediate batch normalization layers and dropout factors to eliminate gaussian noise from the CT images. The skip connections adjoining the network, prevent performance degradation that generally occurs in most autoencoder architectures. Based on the presented study, BMAuto‐Net is reckoned to outperform other traditional filters and autoencoders. The performance measurement of the proposed architecture is performed using the peak signal‐to‐noise ratio (PSNR), mean squared error (MSE), and structured similarity index (SSIM) metric values. The Cancer imaging archive (TCIA) dataset consisting of 19 000 CT images is used to validate the performance of the architecture with average PSNR values of 30.01, 30.53, and 30.52, MSE values of 98.23, 98.87, and 98.94, and SSIM of values of 0.67, 0.60, and 0.57 for noise factors (NFs) of 0.1, 0.3, and 0.5 respectively.
“To imagine I almost said ‘no’”: A Reluctant Student’s Transformation Using Challenging Texts
Authors: Fletcher Lauren
Published: October 2021

This article investigates one undergraduate’s path towards critical literacy around racial inequalities as a result of engaging with, reading, and discussing a challenging children’s novel during a book study with peers. Using Cultural Historical Activity Theory, the author examines the personal and cultural resources the students brought to the experience, the stances she developed while engaging in the book, and the contextual resources that mediated her understanding of racial inequalities. This article further investigates how educators can leverage challenging texts in classrooms to support critical literacy development around societal issues.
Evaluation of antibody response after COVID‐19 vaccination of healthcare workers
Authors: Uysal Elif B. , Gümüş Sibel , Bektöre Bayhan , Bozkurt Hale , Gözalan Ayşegül
Published: October 2021

The common goal of all vaccines developed against COVID‐19, although they have been designed with different methods, is to develop an effective immunity and antibody response against SARS‐CoV‐2. However, the postvaccination immune response and antibody levels differ between individuals. This study examined the relationship between postvaccine seropositivity rates, age, gender, smoking, and body mass index (BMI), and antibody titers. A total of 314 healthcare workers (HCW) who were not previously infected with COVID‐19 and who had received two doses of CoronaVac inactivated vaccine participated in the study. Seropositivity against the receptor‐binding domain (RBD) of the SARS‐CoV‐2 spike protein was measured from the participants 4 weeks after the second dose of vaccine using the electrochemiluminescence (ECLIA) method. In addition, the antibody developed against the nucleocapsid protein (NCP) was evaluated and compared using Elecsys Anti‐SARS‐CoV‐2 kit. One hundred and eighty‐one of the participants were female (57.6%) with a median age of 39 (interquartile range [IQR], 10) and 133 (42.4%) were male with a median age of 41 (IQR, 11). 99.6% of the volunteers developed seropositivity 4 weeks after the second dose of vaccine. It was also observed that the rate of RBD protein antibody titer was >250 U/ml in smokers, which is quite low compared to nonsmokers (p = 0.032), and that high RBD antibody titers were proportionally lower in obese participants, according to BMI values, compared to those with normal BMI (49.5% and 9.9%). It was observed that seropositivity developed in almost all participants after the CoronaVac vaccine. However, it was determined that the antibody titer measured varied depending on factors such as smoking, BMI, and duration.