bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthetic Polymers with Finely Regulated Monomer Sequences: Properties and Emerging Applications
Authors: Laurent Eline , Szweda Roza , Lutz Jean‐François
Published: March 2022

The design of synthetic polymers with controlled monomer sequences is an important emerging trend in polymer science. This new field of research is bio‐inspired by sequence‐defined biopolymers such as proteins and nucleic acids. The chemical synthesis of nonnatural sequence‐controlled polymers (SCPs) has been described in several reviews. However, there is currently little information about the properties and applications of these polymers. In this context, the aim of this article is to give a comprehensive view on these aspects. After a general introduction and a short section about the synthesis of SCPs, the physicochemical properties of these synthetic macromolecules are described in detail. For instance, emphasis is put on the bulk and solution self‐assembly of SCPs. In the last part of this article, potential applications are reviewed and discussed. Overall, SCPs, which are more time‐consuming to synthesize than regular commodity polymers, are not meant to be used in high‐scale applications but more in specialty technologies with high‐added value. For instance, application areas such as data storage, anti‐counterfeiting technologies, catalysis, and photovoltaics are described in this article.
Synthetic Strategies Towards Cyclic Polymers
Authors: Jiang Yu , Ntetsikas Konstantinos , Polymeropoulos George , Zapsas George , Feng Xiaoshuang , Gnanou Yves , Hadjichristidis Nikos
Published: March 2022

Cyclic polymers have attracted considerable interest for their different physical properties compared to the corresponding linear polymers due to the lack of chain ends. The synthesis of cyclic macromolecules has always been a challenge for polymer scientists, mainly due to the difficulties in connecting the ends of the chain. In general, cyclic polymers are synthesized by ring‐closure or ‐expansion techniques, but the main challenge with both methods is the production of highly pure cyclic polymers. In the past two decades, significant developments have been reported, thanks to the advent of controlled polymerizations and efficient coupling reactions in organic chemistry. This article aims to provide a concise overview of the most critical and important synthetic contributions in this field of both ring‐closure and ‐expansion strategies.
Polymer Glasses
Authors: Roth Connie B.
Published: March 2022

Polymers exist in the glass state for a wide range of applications. The slow and limited crystallizability of polymers means that solid polymer materials are either wholly or in part glassy, giving them great importance. The glass is a nonequilibrium amorphous state that occurs because the cooperative molecular dynamics become kinetically trapped on cooling as the available thermal energy for molecular motion decreases. This article aims to provide the reader with a molecular picture of what this packing frustration that causes glass formation means for polymers. Experimental considerations for accurately measuring the glass transition temperature

given this nonequilibrium nature will be discussed. Basic concepts underpinning theoretical efforts to model the glass transition will be summarized to provide the reader with a lexicon and paradigm for understanding different approaches used in the field to capture the main characteristics of glasses. Current research areas of interest in polymer glasses will be briefly outlined. Hopefully, this article will provide the beginning investigator a starting point for their own studies.
Effect of Fiber Orientation on Microstructure and Texture Evolution During the Cold‐Rolling of Al–Mg–Si Alloy
Authors: Chrominski Witold , Lewandowska Malgorzata
Published: March 2022

A material with a strong double fibrous texture is subjected to rolling with various deformation paths—unidirectionally and with 90° rotations about the normal direction (cross‐rolling). Additionally, the orientation of the initial fiber is manipulated to force unlikely grain rotations. The purpose of these procedures is to study the dependence between crystallographic and morphological texture changes caused by the rolling. Microstructure observations show that deformation mechanism responsible for the final microstructure depends on the initial fiber orientation. The crystallographic texture is related to the deformation mode and leads toward expected orientations; however, the initial grain boundaries alignment has a strong impact on the final microstructure. Unidirectional rolling results in typical orientations along the β‐fiber in all investigated cases. The texture created during the more complex deformation path with inset rotations follows the geometrical constraints for fourfold symmetry, even if this required unlikely rotations toward the α‐fiber.
Electron Redistributed S‐Doped Nickel Iron Phosphides Derived from One‐Step Phosphatization of MOFs for Significantly Boosting Electrochemical Water Splitting
Authors: Li Songsong , Wang Lu , Su Hui , Hong Anh N. , Wang Yanxiang , Yang Huajun , Ge Lei , Song Weiyu , Liu Jian , Ma Tianyi , Bu Xianhui , Feng Pingyun
Published: March 2022

Nonprecious transition metal‐organic frameworks (MOFs) are one of the most promising precursors for developing electrocatalysts with high porosity and structural rigidity. This study reports the synthesis of high efficiency electrocatalysts based on S‐doped NiFeP. MOF‐derived S‐doped NiFeP structure is synthesized by a one‐step phosphorization process with using S‐doped MOFs as the precursor, which is more convenient and environment friendly, and also helps retain the samples’ framework. The oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance of the NiFeP catalysts can be improved after partially replacing P by S due to the tunable electronic structure. The optimized CCS‐NiFeP‐10 reaches a current density of 10 mA cm–2 for OER with an overpotential of 201 mV and outperforms most NiFe‐based catalysts. The S doping plays an important role in tuning the ΔG values for intermediates formation in Ni atoms to a suitable value and exhibits a pronouncedly improved the OER performance. CCS‐NiFeP‐20 sample presents excellent HER performance due to the d‐band center downshifting from the Fermi level. When the voltage of the electrolytic cell is 1.50 V, a current density of 10 mA cm–2 can be obtained. This strategy paves the way for designing highly active none‐noble metal catalysts.
A Fully Solution‐Printed Photosynaptic Transistor Array with Ultralow Energy Consumption for Artificial‐Vision Neural Networks
Authors: Shi Jialin , Jie Jiansheng , Deng Wei , Luo Gan , Fang Xiaochen , Xiao Yanling , Zhang Yujian , Zhang Xiujuan , Zhang Xiaohong
Published: March 2022

Photosynaptic organic field‐effect transistors (OFETs) represent a viable pathway to develop bionic optoelectronics. However, the high operating voltage and current of traditional photosynaptic OFETs lead to huge energy consumption greater than that of the real biological synapses, hindering their further development in new‐generation visual prosthetics and artificial perception systems. Here, a fully solution‐printed photosynaptic OFET (FSP‐OFET) with substantial energy consumption reduction is reported, where a source Schottky barrier is introduced to regulate charge‐carrier injection, and which operates with a fundamentally different mechanism from traditional devices. The FSP‐OFET not only significantly lowers the working voltage and current but also provides extraordinary neuromorphic light‐perception capabilities. Consequently, the FSP‐OFET successfully emulates visual nervous responses to external light stimuli with ultralow energy consumption of 0.07–34 fJ per spike in short‐term plasticity and 0.41–19.87 fJ per spike in long‐term plasticity, both approaching the energy efficiency of biological synapses (1–100 fJ). Moreover, an artificial optic‐neural network made from an 8 × 8 FSP‐OFET array on a flexible substrate shows excellent image recognition and reinforcement abilities at a low energy cost. The designed FSP‐OFET offers an opportunity to realize photonic neuromorphic functionality with extremely low energy consumption dissipation.
Engineered Living Hydrogels
Authors: Liu Xinyue , Inda Maria Eugenia , Lai Yong , Lu Timothy K. , Zhao Xuanhe
Published: March 2022

Living biological systems, ranging from single cells to whole organisms, can sense, process information, and actuate in response to changing environmental conditions. Inspired by living biological systems, engineered living cells and nonliving matrices are brought together, which gives rise to the technology of engineered living materials. By designing the functionalities of living cells and the structures of nonliving matrices, engineered living materials can be created to detect variability in the surrounding environment and to adjust their functions accordingly, thereby enabling applications in health monitoring, disease treatment, and environmental remediation. Hydrogels, a class of soft, wet, and biocompatible materials, have been widely used as matrices for engineered living cells, leading to the nascent field of engineered living hydrogels. Here, the interactions between hydrogel matrices and engineered living cells are described, focusing on how hydrogels influence cell behaviors and how cells affect hydrogel properties. The interactions between engineered living hydrogels and their environments, and how these interactions enable versatile applications, are also discussed. Finally, current challenges facing the field of engineered living hydrogels for their applications in clinical and environmental settings are highlighted.
Phenotypic and molecular characterization of five patients with PIK3CA‐related overgrowth spectrum (PROS)
Authors: Gökpınar İli Ezgi , Taşdelen Elifcan , Durmaz Ceren Damla , Altıner Şule , Tuncalı Timur , Martinez‐Glez Victor , Karabulut Halil Gürhan , Vural Seçil , Ceylaner Serdar , Acar Mustafa Oğuz , Ilgın Ruhi Hatice
Published: March 2022

Somatic and germline PI3K‐AKT‐mTOR pathway pathogenic variants are involved in several segmental overgrowth phenotypes such as the PIK3CA‐related overgrowth spectrum (PROS), Proteus syndrome, and PTEN hamartoma tumor syndrome. In this study, we describe five patients with PROS. We identified by high‐throughput sequencing four different somatic PIK3CA pathogenic variants in five individuals. The Glu726Lys variant, which was previously reported in megalencephaly‐capillary malformation‐polymicrogyria (MCAP) syndrome, was identified in two patients with unclassified PROS. The Cys420Arg substitution, which was previously reported in CLOVES, was found in a patient with fibroadipose hyperplasia. Additionally, relatively rare pathogenic variants, His1047Tyr and Tyr1021Cys, were detected in two patients with MCAP. Therefore, we suggest performing deep sequencing of PIK3CA in all patients with suspected PROS, instead of targeted polymerase chain reaction for hotspot pathogenic variants.
Activation of CO Using a 1,2‐Disilylene: Facile Synthesis of an Abnormal N‐Heterocyclic Silylene
Authors: Garg Palak , Carpentier Ambre , Douair Iskander , Dange Deepak , Jiang Yixiao , Yuvaraj K. , Maron Laurent , Jones Cameron
Published: March 2022

Reaction of the 1,2‐disilylene, [{ArC(NDip)2}Si]2 1 (Dip=2,6‐diisopropylphenyl, Ar=4‐C6H4But), with CO proceeds via insertion of CO into one Si−N bond, and Si−Si bond cleavage, to cleanly give the bis(silylene), {ArC(NDip)2}Si(:)O
Ar 2, under ambient conditions. The reaction can be partially reversed when solutions of 2 are subjected to UV irradiation. The five‐membered heterocyclic fragment of 2 represents the first silicon analogue of an “abnormal” N‐heterocyclic carbene (aNHC), a view which is substantiated by a computational analysis of the compound. Reaction of 2 with [Mo(CO)6] under UV light affords the chelate complex, [Mo(CO)4(κ2‐Si,Si‐2)] 3, while reaction with [Fe(CO)5] gives the unusual silyleneyl bridged complex, [{Fe2(CO)6}{μ‐Si[(NDip)2CAr]}2] 4. The same coordination complexes can be accessed by reaction of 1 with [Mo(CO)6] or [Fe(CO)5] under UV light. As is the case for aNHCs, d‐block metal complexes of bis(silylene) 2 could prove useful as bespoke catalysts for organic transformations.
Gold(I)‐Catalyzed Nucleophilic Allylation of Azinium Ions with Allylboronates
Authors: O'Brien Luke , Argent Stephen P. , Ermanis Kristaps , Lam Hon Wai
Published: March 2022

Gold(I)‐catalyzed nucleophilic allylations of pyridinium and quinolinium ions with various allyl pinacolboronates are reported. The reactions are completely selective with respect to the site of the azinium ion that is attacked, to give various functionalized 1,4‐dihydropyridines and 1,4‐dihydroquinolines. Evidence suggests that the reactions proceed through nucleophilic allylgold(I) intermediates formed by transmetalation from allylboronates. Density functional theory (DFT) calculations provided mechanistic insight.
Time‐of‐flight secondary ion mass spectrometric analysis of polymer surfaces: A review
Authors: Prasad Ananthu , Salim Nisa V. , Mozetič Miran , Kailas Lekshmi , Thomas Sabu
Published: March 2022

Time of flight‐secondary ion mass spectrometry (ToF‐SIMS) is a SIMS based surface sensitive technique that provide specific compound identification of surface molecules. Recently, the importance of ToF‐SIMS has grown for the characterization and utilization of polymers, pharmaceuticals, semi‐conductors. The compound specificity of ToF‐SIMS distinguishes it from other surface characterization techniques such as X‐ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), and so forth, making it a preferred tool for the effective surface analysis of polymers. The purpose of this review is to elucidate the capability of ToF‐SIMS technique to effectively analyze the surface chemistry of polymer materials.
Disturbance observer‐based tracking control with prescribed performance specifications for a class of nonlinear systems subject to mismatched disturbances
Authors: Zhou Chengqian , Dai Chen , Yang Jun , Li Shihua
Published: March 2022

This work investigates simultaneous prescribed performance tracking control and mismatched disturbance rejection problems for a class of strict‐feedback nonlinear systems. A novel control scheme combining prescribed performance control, disturbance observer technique, and backstepping method is proposed. The disturbance estimations are introduced into the design of virtual control law design in each step to compensate the mismatched disturbances. To further improve the control performance, a prescribed performance function characterizing the error convergence rate, maximum overshoot, and steady‐state error is used to construct the composite controller. The proposed controller guarantees transient and steady‐state performance specifications of tracking error and provides much better disturbance attenuation ability simultaneously. Rigorous stability analysis for the closed‐loop system is established by direct Lyapunov function method. It is shown that all the states in the resulting closed‐loop system are stable, and the tracking error evolves within the prescribed performance boundaries and asymptotically converges to zero even in the presence of mismatched external disturbances. Finally, theoretical results are illustrated and demonstrated by two simulation examples.
Distributed second‐order multi‐agent constrained optimization algorithm with time‐varying cost function
Authors: Hu Haokun , Mo Lipo , Long Fei
Published: March 2022

This paper mainly discusses distributed constrained optimization problem for second‐order multi‐agent system under undirected communication network. The task of all agents is to minimize the sum of the local convex functions, where each agent is individual and only accesses to one objective function. Different from the most existing results, where the objective functions are assumed to be time‐invariable, this paper considers the situation of time‐varying objective function. Besides, we don't require that the Hessian matrices are identical and the gradients are bounded. First, a novel time‐varying optimization algorithm is proposed based on the projection algorithm. Second, by using convex analysis and Lyapunov theory, it is shown that the states of all agents can reach consensus and asymptotically converge to the neighborhood of the optimal solution. Finally, some numerical examples are given to verify the effectiveness of our algorithms.
Influence of different salts of alkali and alkaline earth metals on the pyrolysis of Prosopis juliflora
Authors: Saynik Philip Bernstein , Moholkar Vijayanand S.
Published: March 2022

This study explores the effect of acetate, oxide and chloride salts of alkali and alkaline earth metals (AAEMs) on the pyrolysis of lignocellulosic biomass. Prosopis juliflora samples were infused using 2% acetate and chloride salts of potassium (CH3COOK, KCl) and the oxide and chloride salts of magnesium (MgO, MgCl2). Dry impregnation technique was employed for the infusion of salts into the biomass matrix. The AAEM salt‐infused biomass was pyrolyzed using a semi‐batch pyrolysis reactor, and the bio‐oils were characterized for variation in chemical composition using gas chromatography–mass spectroscopy. The AAEM salts significantly influenced the pyrolysis process by catalyzing different degradation pathways. Potassium salts catalyzed the ring fission reactions of carbohydrates, resulting in an increase in carboxylic acid yield. On the other hand, magnesium salts promoted the cyclization of the fragmented radicals of the ring fission, resulting in enhanced furan and cycloketone yield. AAEM salts were most effective in catalyzing carbohydrate degradation pathways over the lignin degradation reactions owing to their ability to easily influence polysaccharide C–C bond cleavage over those of lignin aromatic rings. This study also revealed that the anions of AAEM salts also play a major role in biomass pyrolysis. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd
Multiple gene expression in plants using MIDAS‐P, a versatile type II restriction‐based modular expression vector
Authors: Pinneh Elizabeth C. , van Dolleweerd Craig J. , Göritzer Kathrin , Drake Pascal M. W. , Ma Julian K‐C. , Teh Audrey Y‐H.
Published: March 2022

MIDAS‐P is a plant expression vector with blue/white screening for iterative cloning of multiple, tandemly arranged transcription units (TUs). We have used the MIDAS‐P system to investigate the expression of up to five genes encoding three anti‐HIV proteins and the reporter gene DsRed in Nicotiana benthamiana plants. The anti‐HIV cocktail was made up of a broadly neutralizing monoclonal antibody (VRC01), a lectin (Griffithsin), and a single‐chain camelid nanobody (J3‐VHH). Constructs containing different combinations of 3, 4, or 5 TUs encoding different components of the anti‐HIV cocktail were assembled. Messenger RNA (mRNA) levels of the genes of interest decreased beyond two TUs. Coexpression of the RNA silencing suppressor P19 dramatically increased the overall mRNA and protein expression levels of each component. The position of individual TUs in 3 TU constructs did not affect mRNA or protein expression levels. However, their expression dropped to non‐detectable levels in constructs with four or more TUs each containing the same promoter and terminator elements, with the exception of DsRed at the first or last position in 5 TU constructs. This drop was alleviated by co‐expression of P19. In short, the MIDAS‐P system is suitable for the simultaneous expression of multiple proteins in one construct.
Prevention of epicardial coronary artery spasm with intracoronary nitroglycerine during acetylcholine testing in a female patient with resting angina—implications for optimal pharmacological management
Authors: Martínez Pereyra Valeria , Seitz Andreas , Sechtem Udo , Ong Peter
Published: March 2022

We here present the case of a 55‐year old woman who presented with recurrent angina at rest followed by presyncopal attacks and nausea to our clinic. Her only cardiovascular risk factor was arterial hypertension. High‐sensitive troponin T was 3 pg/ml (n < 14 pg/ml) and the 12‐lead resting ECG was unremarkable. Differential diagnoses included stenosing coronary artery disease and coronary artery spasm. Thus, invasive coronary angiography was performed showing unobstructed coronary arteries. Acetylcholine (ACh) provocation testing in search of coronary spasm showed diffuse epicardial spasm of the left anterior descending coronary artery (LAD) and focal spasm of the left circumflex coronary artery (LCX), which could be resolved by intracoronary administration of 0.2 mg nitroglycerine (NTG). To evaluate the potential protective effect of NTG, ACh provocation testing was repeated after NTG injection. This rechallenge showed no more epicardial spasm, suggesting that NTG had a protective antispastic effect on the epicardial arteries in this patient. Symptom control in patients with angina due to coronary artery spasm can be challenging as pharmacological agents are often prescribed on a trial and error basis. With this case, we present a novel approach toward a more individualized pharmacotherapy in coronary artery spasm using a modified protocol for invasive coronary spasm testing, which could avoid ineffective treatment trials in such patients.
Crimean‐Congo hemorrhagic fever in the COVID‐19 pandemic: A case study
Authors: Mardani Masoud , Aghazadeh Sarhangipour Kouros , Nikpour Shahriar , Hakamifard Atousa
Published: March 2022

In the COVID‐19 pandemic, the overlap of clinical features between other viral infections makes a reliable diagnosis difficult in the initial stage of illness. We describe a confirmed case of CCHF in Tehran Province during this year, who was first misdiagnosed as COVID‐19 infection.
A variant of Takotsubo syndrome concomitant with left atrial myxoma
Authors: Ishibashi Naoki , Nagai Michiaki , Dote Keigo , Kato Masaya , Oda Noboru , Tachibana Hitoshi , Katayama Akira
Published: March 2022

We treated an 80‐year‐old Japanese woman who had Takotsubo syndrome (TTS) concomitant with a left atrial (LA) tumor. Left ventriculography revealed a variant of TTS. In cardiac surgery, the LA mass was successfully resected without embolism, with the pathological diagnosis of myxoma.
Lipodystrophy: Still an underdiagnosed complication of subcutaneous insulin administration
Authors: Barbosa Mariana , Silva Ana Sara , Fernandes Vera
Published: March 2022

Lipodystrophy is a common but often underdiagnosed complication of subcutaneous insulin injections. We present an illustrative case, aiming to remind physicians to consider lipodystrophy when evaluating a patient under insulin therapy with otherwise unexplained metabolic decompensation. A complete physical examination and patient education are crucial in this setting.
Progressive compression and weight reinforcement for spiking neural networks
Authors: Elbez Hammouda , Kamel Benhaoua Mohammed , Devienne Philippe , Boulet Pierre
Published: March 2022

Neuromorphic architectures are one of the most promising architectures to reduce the energy consumption of tomorrow's computers. These architectures are inspired by the behavior of the brain at a fairly precise level and consist of artificial spiking neural networks. To optimize the implementation of these architectures, we propose in this article a novel progressive network compression and reinforcement technique. This technique consists of two functions: progressive pruning and dynamic synaptic weight reinforcement, which we apply after each training batch. The proposed approach delivers a highly compressed network (up to 80% of compression rate) while preserving the network performance when tested with MNIST.
Ethyl Zinc β‐Ketoiminates and β‐Amidoenoates: Influence of Precursor Design on the Properties of Highly Conductive Zinc Oxide Thin Films from Aerosol‐Assisted Chemical Vapour Deposition.
Authors: Bhide Malavika A. , Carmalt Claire J. , Knapp Caroline E.
Published: March 2022

Highly transparent (>85 %) and conductive (1.086×10−3 Ω cm) zinc oxide thin films have been deposited from specifically selected precursors allowing us to establish a direct correlation between their molecular structure and the optoelectronic properties of the deposited films. Mono‐ligated ethyl zinc compounds of varying steric bulk: [EtZn(OC(Me)CH(Me)N(iPr))]2 (1), [EtZn(OC(OEt)CH(Me)N(iPr))]2 (2) and [EtZn(OC(OEt)CH(CH3)N(Dipp))]2 (3) were compared with the related bis‐ligated zinc complexes [Zn(OC(Me)CH(Me)N(iPr))2] (4), [Zn(OC(OEt)CH(Me)N(iPr))2] (5) and [Zn(OC(OEt)CH(Me)N(Dipp))2] (6). In all cases bulkier ligands resulted in poorer electronic properties of deposited films, whilst all mono‐ligated compounds were shown as superior precursors. All complexes were characterised by 1H and 13C{1H} NMR and elemental analysis, with the structure of 6 determined by single crystal X‐ray diffraction. Zinc oxide films were deposited from single and dual source (with methanol) reactions of these precursors, and analysed via XRD, XPS and EDX. Optoelectronic properties were investigated through UV/vis spectroscopy and Hall effect measurements, and morphology was examined via SEM. Tauc plots from UV/vis data indicated that Film A showed the lowest band gap of 3.31 eV. Varying the elemental composition of the precursors led to changes in the elemental composition of the resultant films, as well as changes in their structural and optoelectronic properties. Using this approach of precursor design, we have been able to tune single source precursors towards zinc oxide to deposit films with specific properties.
Photovoltaic‐based grid‐connected transformer‐less three‐phase cascaded diode‐clamped multilevel inverter with reduced leakage current
Authors: Rao Pandry Narendra , Saini Lalit Mohan
Published: March 2022

A photovoltaic (PV) transformer‐less grid‐connected cascaded diode‐clamped half‐bridge multilevel inverter (MLI) is presented in this paper. Compared with the conventional cascaded H‐bridge (CHB) multilevel inverter, the projected inverter permits connection of double the DC‐link voltage and hence enhances its rating. The most common problem the PV‐based transformer‐less grid‐connected CHB MLI system faces is the flow of leakage currents created by parasitic capacitances due to the disparity in common‐mode voltage. As per the German standards VDE‐V‐0126‐1‐1, the leakage current must be less than 30 mA. In the proposed inverter, due to the high‐frequency pulse width modulation of voltage, a peak leakage current flow of nearly 300 mA at switching frequency (2500 Hz) and about 150 mA at its subsequent harmonics is observed. Therefore, LC‐filters are employed in the proposed inverter to suppress the peak leakage currents to less than 3 mA. Also, the LC‐filters improve the total harmonic distortion (THD) profile of the injected grid current. Further, the proposed inverter is also designed to address the temporary faults. The proposed transformer‐less inverter is simulated using the MatLab/Simulink platform, and the results are experimentally validated by performing on a real‐time hardware‐in‐the‐loop using OPAL‐RT OP5700 digital simulator as plant and dSPACE 1202 as controller.
Probabilistic classification of anti‐SARS‐CoV‐2 antibody responses improves seroprevalence estimates
Authors: Castro Dopico Xaquin , Muschiol Sandra , Grinberg Nastasiya F , Aleman Soo , Sheward Daniel J , Hanke Leo , Ahl Marcus , Vikström Linnea , Forsell Mattias , Coquet Jonathan M , McInerney Gerald , Dillner Joakim , Bogdanovic Gordana , Murrell Ben , Albert Jan , Wallace Chris , Karlsson Hedestam Gunilla B
Published: March 2022

Objectives

Population‐level measures of seropositivity are critical for understanding the epidemiology of an emerging pathogen, yet most antibody tests apply a strict cutoff for seropositivity that is not learnt in a data‐driven manner, leading to uncertainty when classifying low‐titer responses. To improve upon this, we evaluated cutoff‐independent methods for their ability to assign likelihood of SARS‐CoV‐2 seropositivity to individual samples.

Methods

Using robust ELISAs based on SARS‐CoV‐2 spike (S) and the receptor‐binding domain (RBD), we profiled antibody responses in a group of SARS‐CoV‐2 PCR+ individuals (n = 138). Using these data, we trained probabilistic learners to assign likelihood of seropositivity to test samples of unknown serostatus (n = 5100), identifying a support vector machines‐linear discriminant analysis learner (SVM‐LDA) suited for this purpose.

Results

In the training data from confirmed ancestral SARS‐CoV‐2 infections, 99% of participants had detectable anti‐S and ‐RBD IgG in the circulation, with titers differing > 1000‐fold between persons. In data of otherwise healthy individuals, 7.2% (n = 367) of samples were of uncertain serostatus, with values in the range of 3‐6SD from the mean of pre‐pandemic negative controls (n = 595). In contrast, SVM‐LDA classified 6.4% (n = 328) of test samples as having a high likelihood (> 99% chance) of past infection, 4.5% (n = 230) to have a 50–99% likelihood, and 4.0% (n = 203) to have a 10–49% likelihood. As different probabilistic approaches were more consistent with each other than conventional SD‐based methods, such tools allow for more statistically‐sound seropositivity estimates in large cohorts.

Conclusion

Probabilistic antibody testing frameworks can improve seropositivity estimates in populations with large titer variability.
Morphology analysis of unlabeled red blood cells based on quantitative differential phase contrast microscopy
Authors: He Linna , Shao Meng , Yang Xiao , Si Li , Jiang Mengduo , Wang Tao , Ke Zeyu , Peng Tao , Fang Shu , Zhang Shengzhao , Ouyang Xilin , Zhao Gang , Zhou Jinhua
Published: March 2022

The current classical blood smear technique to observe the morphology of single red blood cells (RBCs) for classification is a laborious and error‐prone process. To objectively evaluate the morphology of blood cells, we established a method of computational imaging based on a programmable light emitting diode array. By using quantitative differential phase contrast (qDPC), we characterized the morphology of unlabeled RBCs as well as blood smears. By focusing on comparing the difference of imaging between unlabeled RBCs and stained RBCs under multimode microscopic imaging technology, we demonstrated that qDPC could clearly differentiate discocytes and spherocytes in both unlabeled RBCs and blood smears. The phase map provided by quantitative phase imaging further enhanced the classification accuracy. According to statistical analysis from morphological indexes, the qDPC imaging has a significantly improvement in non‐circularity, texture inhomogeneity and equivalent diameters of cells. Thus, this method has a significant superiority in the capability to analyze the morphology of RBCs and could be applied to clinical assays for determining morphological, functional, and structural deterioration of RBCs.
Vanet‐TSMA: A traffic safety management approach for smart road transportation in vehicular ad hoc networks
Authors: Kaul Ajay , Altaf Insha
Published: March 2022

Over the past two decades, vehicular collisions have been a significant concern for governments, researchers, and automobile manufacturers. However, collisions are unexpected and occur regularly on roads, resulting in deaths, infrastructure destruction, and health injuries. As a result, it is essential to avoid, prevent, and detect traffic collisions at the highest degree possible for minimizing human loss. In this article, the trend of road traffic accidents in India has been analyzed graphically. Towards the end, a VANET‐based traffic safety management approach (VANET‐TSMA) has been proposed to reduce road accidents in India. This approach uses message distribution, traffic management, and congestion control efficiently for reducing the overall rate of road accidents. This method is based on multiple information and communication technology (ICT)‐based safety mechanisms which include collision avoidance, collision detection, and traffic congestion avoidance for the protection of future connected automobiles on roads.
Development of dynamic wireless power transfer system for vehicle logistics robot
Authors: Shimizu Osamu , Hanabusa Kazuyoshi , Arasaki Kota , Gunji Daisuke , Sakai Yuto , Ikeda Hiromori , Matsuoka Fuminori
Published: March 2022

Laborsaving is a major issue in production. In an automotive production line, a yard that is used as a temporary storage for vehicles before shipping. The vehicle‐loading robot that operates autonomously has been proposed to automate the alignment of vehicles in the yard instead of human driving. In this study, the dynamic wireless power transfer (DWPT) system that includes the structure of the roadside for the vehicle‐loaded robot is proposed. It is proven that the transmitter coil has enough durability for the load of the robot weight using simulation and actual measurement. It is also shown that the reinforcement bars of the road structure cause considerable eddy current loss even with stainless steel. This is similar to loss by coil resistance. This system achieves a 1.8 kW DWPT with an automated coil detection system and a frequency control system, under factory conditions.
Fluid friction/heat transfer irreversibility and heat function study on MHD free convection within the MWCNT–water nanofluid‐filled porous cavity
Authors: Kumar Alagarsamy Vanav , Lawrence Jino , Saravanakumar G.
Published: March 2022

The study comprises the effect of natural/free convection on an MWCNT–water nanofluid‐filled cavity. The porous cavity is heated/cooled to the left/right walls and the horizontal wall is maintained adiabatically. The flow behavior and entropy analysis are evaluated numerically using the finite difference approximation techniques. This study is bounded with various dimensional parameters such as —nanoparticle concentration, Ha—Hartmann number, Ra—Rayleigh number, and Da—Darcy number. The results of the study are illustrated using —streamlines or stream function, —isotherms, —heatlines or heat function, —fluid friction irreversibility, —heat transfer irreversibility, —cup‐mixing temperature, and —root‐mean‐square deviation. Also, —average Nusselt number and —average Bejan number are used to represent the transfer rate of heat and irreversibility of fluid friction/heat transfer, respectively. The domination of conduction on lower Ra and Da are noticed and, domination of convection on higher Ra and Da are observed using a heatline map. The fluid friction and heat transfer irreversibilities are highly noted near the vertical boundaries for increasing Rayleigh number and Darcy number.
Selective inhibitors of bromodomain BD1 and BD2 of BET proteins modulate radiation‐induced profibrotic fibroblast responses
Authors: Liu Chun‐Shan , Rioja Inmaculada , Bakr Ali , Veldwijk Marlon R. , Sperk Elena , Herskind Carsten , Weichenhan Dieter , Prinjha Rab K. , Plass Christoph , Schmezer Peter , Popanda Odilia
Published: March 2022

Radiotherapy can induce various adverse effects including fibrosis in cancer patients. Radiation‐induced aberrant expression of profibrotic genes has been associated with dysregulated epigenetic mechanisms. Pan‐BET (bromodomain and extraterminal domain) inhibitors, such as JQ1 and I‐BET151, have been reported to attenuate the profibrotic response after irradiation. Despite their profound preclinical efficacy, the clinical utility of pan‐inhibitors is limited due to observed cytotoxicicities. Recently, inhibitors were developed that selectively target the first (BD1) and second (BD2) bromodomain of the BET proteins (iBET‐BD1 [GSK778] and iBET‐BD2 [GSK046]). Here, their potential to attenuate radiation‐induced fibroblast activation with low‐toxicity was investigated. Our results indicated that cell proliferation and cell cycle progression in fibroblasts from BJ cells and six donors were reduced when treated with I‐BET151 and iBET‐BD1, but not with iBET‐BD2. After irradiation, induction of DGKA and profibrotic markers, especially COL1A1 and ACTA2, was attenuated with all BET inhibitors. H3K27ac enrichment was similar at the DGKA enhancer region after I‐BET151 treatment and irradiation, but was reduced at the COL1A1 transcription start site and the ACTA2 enhancer site. iBET‐BD2 did not change H3K27ac levels in these regions. BRD4 occupancy at these regions was not altered by any of the compounds. Cell migration activity was measured as a characteristic independent of extracellular matrix production and was unchanged in fibroblasts after irradiation and BET inhibitor‐treatment. In conclusion, iBET‐BD2 efficiently suppressed radiation‐induced expression of DGKA and profibrotic markers without showing cytotoxicity. Thus BD2‐selective targeting is a promising new therapeutic avenue for further investigations to prevent or attenuate radiotherapy‐induced fibrosis.
Social and general anhedonia in adolescents: Stability and associations with other symptoms
Authors: Yang Xinhua , Guo Yuqi , Harrison Phillippa , Liu Xiaoqun
Published: March 2022

Introduction

Recent works have developed two self‐report measures of general and social anhedonia for adolescents. Little is known about the relative stability of these constructs and their associations with psychopathological symptoms over time.

Methods

A total of 694 Chinese adolescents aged 14–16 years (74.6% girls) completed measures of anhedonia at two time points 1 year apart. General anhedonia was assessed using the Snaith Hamilton Pleasure Scale while social anhedonia was assessed using the Adolescent Anticipatory and Consummatory Interpersonal Pleasure Scale.

Results

General and social anhedonia significantly increased over time, F(1, 693) =16.54, p < .001, η2 = 0.02; F(1, 693) =27.31, p < .001, η2 = 0.04. Greater depression (b = ‐0.10, p = .006), suicidal ideation (b = ‐0.55, p < .001), generalized anxiety (b = ‐0.28, p = .012), social anxiety (b = ‐0.28, p = .002), and interpersonal stressful events (b = ‐0.20, p = .035) were associated with greater social anhedonia. Suicidal ideation was associated with general anhedonia (b = 0.29, p = .004). Higher positive schizotypal personality was associated with less general and social anhedonia (b = ‐0.18, b = 0.16, all p < .001) whereas higher negative schizotypal personality was associated with greater general and social anhedonia (b = 0.34, b = ‐0.58, all p < .001).

Conclusions

This finding suggests that anhedonia is an increasing trend during adolescence. The relationship between anhedonia and psychopathology was specific to social anhedonia.
A method to measure the uniformity of the virtual image distance in an augmented reality or virtual reality device
Authors: Hong Hyungki
Published: March 2022

The virtual image distance in an augmented reality (AR) or virtual reality (VR) device is an important factor in determining its performance. In this paper, a method for measuring the virtual image distance and its uniformity is proposed. The setup for measurement consists of a two‐dimensional spatial sensor array on the translational stage and a pinhole array plate placed in front of the AR or VR device. As the distance between the pinhole plate and the two‐dimensional spatial sensor array were changed, the positions of the rays through each pinhole were measured by a two‐dimensional spatial sensor array. The ray trajectories through each pinhole were obtained by fitting these positions to straight lines. The relative distances between these ray trajectories were calculated with respect to the distance from the pinhole plate. This method is effective for measuring the uniformity, such as the azimuthal dependence of the virtual image distance or the dependence of the virtual image distance on the distance from the optical axis of the VR lens.
R&D performance and international diversification: Evidence from an emerging market
Authors: Chang Tzu‐Lin , Wang Hsiao‐Wen , Lin Keng‐Pei , Chen Hsin‐Yu
Published: March 2022

This study investigates the impact of international diversification on the lag effect of R&D performance for implementing an international diversification strategy. The study uses the sales base amount and the number of countries, respectively, to explain the depth and breadth of international diversification. The results suggest that the higher the level of international diversification, the more profound the positive impact of the international diversification on the R&D activities‐derived operating performance. The study also confirms that companies with broader international diversification have a higher positive R&D lag effect. The empirical results are robust to the problem of endogeneity.
Substitutability research for forward‐scatter meters in indoor low‐visibility environments
Authors: Zhuang Zibo , Li Jinfeng , Chan Pak Wai , Tai Hongda
Published: March 2022

Visibility is a crucial parameter for aeronautical operations. Forward‐scatter meters are recommended to measure it because of inherent advantages. With wide use at airports, the substitutability among forward‐scatter meters is worth paying attention to, especially in low‐visibility environments. To confirm the substitutability among forward‐scatter meters, eight kinds of forward‐scatter meters were installed in an indoor atmospheric environment simulation chamber. The observed values of each of the eight forward‐scatter meters in haze and smoke low‐visibility environments were collected. By least‐squares fitting analysis and the ATE/LER zones method, in the haze, the two sets of CS125 can be substituted for each other in visibilities lower than 2000 m. PWD20 and V30 can be substituted for each other at visibilities lower than approximately 1200 m. From 1200 to 2000 m, the consistency of the two instruments is poor. In the smoke, CS125 and PWD20 display good substitutability with each other when visibility is less than 2000 m. If only focusing on visibilities less than approximately 1000 m, the VPF‐710 and V30 instruments can be substituted with each other.
Predictors of post‐hip fracture knee pain in hospitalized older adults with intertrochanteric femoral fracture
Authors: Kaizu Yoichi , Miyata Kazuhiro , Arii Hironori
Published: March 2022

Background

Post‐hip fracture knee pain (PHFKP) is an important issue that contributes to reduced gait speed and prolonged hospitalization. Femoral morphology has been reported to contribute to the development of PHFKP, but an independent association has not been confirmed and clinically applicable cutoffs for predicting the development of PHFKP remain unclear.

Objective

To determine whether femoral morphology and knee extension range of motion limitation are independent factors in PHFKP and to determine cutoffs for predicting the development of PHFKP.

Design

Retrospective chart review study.

Setting

Convalescent inpatient rehabilitation hospital.

Participants

Patients in a convalescent ward after intertrochanteric femoral fracture surgery.

Main Outcome Measures

PHFKP development, radiographic femoral morphology (leg length discrepancy and neck‐shaft angle), and knee extension range of motion limitation.

Results

PHFKP developed in 36 (35%) of the 103 patients enrolled. The PHFKP group had a longer hospital stay (p = .029), greater weight (p = .031), greater knee extension range of motion limitation (p = .001), and more varus neck‐shaft angle (p < .001) compared to the non‐PHFKP group. Varus neck‐shaft angle (odds ratio, 0.85; 95% confidence interval [CI], 0.78–0.92; p < .001) and knee extension range of motion limitation (odds ratio, 1.18; 95% CI, 1.07–1.30; p = .001) were significant factors for PHFKP development. Neck‐shaft angle discrepancy and knee extension range of motion limitation demonstrated moderate accuracy in discriminating development of PHFKP according to receiver operating characteristic analysis, with cutoffs of 9.6° and 7.5°, respectively. Areas under the receiver operating characteristic curve were 0.77 (95% CI, 0.66–0.88; p < .001) for neck‐shaft angle discrepancy and 0.67 (95% CI, 0.56–0.79; p = .004) for knee extension range of motion limitation.

Conclusions

Varus neck‐shaft angle and knee extension range of motion limitation were identified as independent predictors of PHFKP. The cutoff for neck‐shaft angle may be useful for predicting PHFKP development and to define an acceptable angle of fracture reduction to prevent PHFKP.
3D Printing of Thiol‐Yne Photoresins through Visible Light Photoredox Catalysis
Authors: Wu Yimei , Simpson M. Cather , Jin Jianyong
Published: March 2022

In this work, we report a visible light active thiol‐yne photoresin formulation that is printable with digital light processing (DLP) 3D printer under irradiation of blue‐light (λmax=470 nm). The resulting objects have the Z axis resolution of 250 μm (layer thickness) and building speed of (5 mm/h). Uniquely, our thiol‐yne photoresin contains photoredox catalysts Eosin Y and fac‐Ir(ppy)3, which initiate the photopolymerization through a photoredox mechanism. The optimized dual catalysts EY/fac‐Ir(ppy)3 system not only facilitate the faster thiol‐yne reaction but also potentially enables wider visible light wavelength coverage for 3D printing process. This work illustrates the possibility of replacing traditional photoinitiator with photoredox catalysts in the visible light range, thus, enriching the photoresin formulations for polymer‐based 3D printing industry.
Visible light driven instantaneous photocatalytic degradation of aniline blue (AB) and methyl violet (MV) by strontium ferrite nanoparticles
Authors: Thakurata Debasish Guha , Das Krishna Chandra , Paul Arijita , Dhar Siddhartha Sankar
Published: March 2022

Toxic organic dyes released into aquatic sources as a result of industrial activities pose a significant threat to the environment. The removal of such dyes from water sources is a challenging task in the context of environmental emergencies. In this present effort, the strontium ferrite nanoparticles were synthesized by coprecipitation followed by a calcination method and is applied for photocatalytic degradation of such organic dyes. The ferrite nanoparticles were characterized by FTIR, XRD, VSM, SEM‐EDX, TEM, and HR‐TEM studies. In the existence of H2O2 under visible light, the catalyst performs efficient degradation of aniline blue (AB) and methyl violet (MV) dyes in a remarkably short interval of time. The superparamagnetic performance of the catalyst was confirmed by VSM, and thus it can be easily recovered from the degraded dye by applying an external magnet. The Fenton mechanism justifies the elevated rate of photo degradation, which generates hydroxyl and perhydroxyl radicals in the progress of the reaction.
Scaling black holes and modularity
Authors: Chattopadhyaya Aradhita , Manschot Jan , Mondal Swapnamay
Published: March 2022

Abstract

Scaling black holes are solutions of supergravity with multiple black hole singularities, which can be adiabatically connected to a single center black hole solution. We develop techniques to determine partition functions for such scaling black holes, if each constituent carries a non-vanishing magnetic charge corresponding to a D4-brane in string theory, or equivalently M5-brane in M-theory. For three constituents, we demonstrate that the partition function is a mock modular form of depth two, and we determine the appropriate non-holomorphic completion using generalized error functions. From the four-dimensional perspective, the modular parameter is the axion-dilaton, and our results show that S-duality leaves this subset of the spectrum invariant. From the five-dimensional perspective, the modular parameter is the complex structure of a torus T2, and the scaling black holes are dual to states in the dimensional reduction of the M5-brane worldvolume theory to T2. As a case study, we specialize the compactification manifold to a K3 fibration, and explicitly evaluate holomorphic parts of partition functions.