bluuebunny/crossref_metadata_2025 huggingface dataset:
Self‐Assembly of Nanographenes
Authors: Matsumoto Ikuya , Sekiya Ryo , Haino Takeharu
Published: March 2021

Suitably decorated small aromatic systems can organize stacked structures that display interesting properties arising from their unique morphologies. Although nanographenes produced by top‐down methods have graphitic domains and can in principle be applied for such supramolecular systems, to our knowledge, no such example has been reported thus far. This is partly because of their limited solubility in organic solvents and partly because of their wide lateral size distribution. To realize nanographene‐based supramolecular aggregates, nanographenes carrying alkyl chains with narrow lateral size distributions are employed. We find that the nanographenes undergo self‐assembly and that self‐assembly is regulated by concentration, solvent polarity, temperature, and sonication. Optical measurements and AFM images indicate that stacked structures are possible candidates for aggregates. A molecular mechanics calculation models the interactions in the aggregates. The nanographenes showed concentration‐dependent morphologies on mica, stacked structures at low concentrations and polymer‐like network structures on mica at higher concentrations.
Scalable Total Synthesis, IP3R Inhibitory Activity of Desmethylxestospongin B, and Effect on Mitochondrial Function and Cancer Cell Survival
Authors: Podunavac Maša , Mailyan Artur K. , Jackson Jeffrey J. , Lovy Alenka , Farias Paula , Huerta Hernan , Molgó Jordi , Cardenas Cesar , Zakarian Armen
Published: March 2021

The scalable synthesis of the oxaquinolizidine marine natural product desmethylxestospongin B is based on the early application of Ireland–Claisen rearrangement, macrolactamization, and a late‐stage installation of the oxaquinolizidine units by lactam reduction. The synthesis serves as the source of material to investigate calcium signaling and its effect on mitochondrial metabolism in various cell types, including cancer cells.
Dispersion‐Bound Isolated Dimers in the Gas Phase: Observation of the Shortest Intermolecular CH⋅⋅⋅H−C Distance via Stimulated Raman Spectroscopy
Authors: Maué Dominique , Strebert Patrick H. , Bernhard Dominic , Rösel Sören , Schreiner Peter R. , Gerhards Markus
Published: March 2021

The triphenylmethane and all‐meta tert‐butyl triphenylmethane dimers, (TPM)2 and (T tBuPM)2, respectively, were studied with ionization loss stimulated Raman spectroscopy in molecular beam experiments to resolve structure sensitive vibrations. This answers the question whether the recently reported linear head‐to‐head arrangement in (T tBuPM)2 results from crystal packing or prevails also in the gas phase, and therefore must result from extraordinarily strong London dispersion (LD) interactions. Our study clearly demonstrates that the head‐to‐head arrangement is maintained even under isolated molecular beam conditions in the absence of crystal packing effects. The central Raman‐active aliphatic C−D vibration of appropriately deuterated (T tBuPM)2 associated with an unusually short C−D⋅⋅⋅D−C distance exhibits a strong blue‐shift compared to the undisturbed case. As the LD stabilizing tert‐butyl groups are absent in (TPM)2, it displays an approximately S6‐symmetric tail‐to‐tail arrangement.
Strong Lewis and Brønsted Acidic Sites in the Borosulfate Mg3[H2O→B(SO4)3]2
Authors: Netzsch Philip , Stroh Regina , Pielnhofer Florian , Krossing Ingo , Höppe Henning A.
Published: March 2021

Borosulfates provide fascinating structures and properties that go beyond a pure analogy to silicates. Mg3[H2O→B(SO4)3]2 is the first borosulfate featuring a boron atom solely coordinated by three tetrahedra. Thus, the free Lewis acidic site forms a Lewis acid–base adduct with a water molecule. This is unprecedented for borosulfate chemistry and even for borates. Quantum chemical calculations on water exchange reactions with BF3 and B(C6F5)3 revealed a higher Lewis acidity for the borosulfate anion. Moreover, proton exchange reactions showed a higher Brønsted acidity than comparable silicates or phosphates. Additionally, Mg3[H2O→B(SO4)3]2 was characterised by X‐ray diffraction, infrared spectroscopy, thermogravimetric analysis, and density functional theory (DFT) calculations.
Endogenous Symbiotic Li3N/Cellulose Skin to Extend the Cycle Life of Lithium Anode
Authors: Luo Yang , Li Tianyu , Zhang Hongzhang , Liu Wei , Zhang Xiaoben , Yan Jingwang , Zhang Huamin , Li Xianfeng
Published: March 2021

Nitrocellulose (NC) is proposed to stabilize the electrolytes for Li metal batteries. The nitro group of NC preferentially reacts with Li metal, and along with the cellulose skeleton is tightly wrapped on the surface, so that the polymer–inorganic double layer is formed on the Li surface. XPS profile analysis and corroborative cryo‐environmental TEM reveal that the flexible outer layer of the bilayer is a C‐O organic layer, while the dense inner layer is mainly composed of crystalline lithium oxide, lithium oxynitride, and lithium nitride. The Li deposition process was observed via in situ optical microscopy, which indicated that the NC‐derived bilayer facilitates the uniform deposition of Li ions and inhibits the growth of dendrites. After the introduction of NC into the electrolyte, the cycle life of the Li battery is twice than that of the Li battery without NC at 1.0 and 3.0 mA cm−2.
Fabrication and evaluation of hydrophilic cross‐linked polystyrene nanoparticles as a potential in‐depth conformance control agent for low‐permeability reservoirs
Authors: He Jie , Chen Qingmei , Zhao Wei , Chen Fu , Shao Minglu
Published: March 2021

To address the poor injectivity of conventional chemicals, and the drawbacks of existing nanoparticles (NPs) in in‐depth conformance control in low‐permeability reservoirs, a hydrophilic cross‐linked polystyrene NPs named as CPSAs was fabricated via emulsion polymerization in this study. The reaction conditions were determined through orthogonal experiments, and the influence of each condition on the particle size of CPSAs was investigated with single factor experiments. The results showed that CPSAs with the mean diameter ranging from 73 to 95 nm could be readily produced by moderately changing the polymerization conditions, and the yield could be larger than 80%. The property evaluation results indicated that CPSAs can disperse well under reservoir conditions and was able to properly propagate to deep formation and block breakthrough regions, revealing the good injectivity and in‐depth conformance control capability in low‐permeability reservoirs.
Creep mechanical properties and creep model of high water material under step loading
Authors: Li Xiaolong , Liu Changwu
Published: March 2021

High water material, a kind of filling and supporting material, is widely used in underground engineering, whose creep mechanical properties are directly related to the underground engineering stability. In this paper, creep tests of different types of high water material are carried out. The results show that: for the complete specimen and the single and double crack specimens with crack inclination angles of 0°, 30°, and 60°, the curves present initial elastic, creep attenuation and creep stabilization in the first four stages, and the creep acceleration appears in the fifth stage, leading to the final failure of the specimen; for the single and double crack specimens with a crack inclination angle of 90°, no creep acceleration appears. According to the test results, a new nonlinear viscoplastic body is proposed, and connected with the traditional Nishihara model, forming the nonlinear Nishihara model. The new model can clearly describe the creep characteristics of complete and cracked specimens at different stages. Finally, according to the new creep model, crack parameters are discussed with the creep rate index and the starting time of accelerated failure.
Green analogs of polybutadienes from carbon dioxide and epoxy‐based feedstocks
Authors: Kansal Dhwani , Abouomar Ramadan , Rabnawaz Muhammad
Published: March 2021

Polybutadiene has widespread use as a commodity as well as a specialty polymer, but currently, it is prepared from non‐renewable feedstocks. Herein, we report the synthesis of rubbery unsaturated polycarbonates (RUPCs) as green alternatives for polybutadiene. We prepared two RUPCs (respectively, denoted as RUPC1 and RUPC2) via the copolymerization of carbon dioxide (CO2) and a mixture of saturated and unsaturated long‐chain epoxides using a Co(III) catalyst. The RUPCs were reacted with a styrene monomer via free‐radical polymerization to prepare RUPC‐graft‐Polystyrene. All of the prepared polymers were characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. For RUPC, the number average molecular weight (Mn) increased by three‐fold after the grafting reaction. Differential scanning calorimetry analysis confirmed that the glass transition temperature (Tg) of the RUPCs were low (~ −40°C) and approached those of polybutadienes. After polystyrene chains had been grafted onto the RUPC backbone, the Tg increased to 81°C. These green RUPCs have the potential to replace non‐renewable polybutadiene in some applications such as high impact materials.
An Overview on Protecting Metal Anodes with Alloy‐Type Coating
Authors: Touja Justine , Louvain Nicolas , Stievano Lorenzo , Monconduit Laure , Berthelot Romain
Published: March 2021

The current revival of lithium metal batteries (LMB) has been driven by both the search for high energy‐density systems and the development of solid‐state batteries. Lithium electrode surface engineering is crucial to limit both the dendritic growth and the electrolyte reduction. Among the various strategies to obtain protecting layers, there has been a recent growing interest in metal coatings forming alloys with lithium. Here, various strategies to coat lithium and other metal electrodes (sodium, potassium and magnesium) are reviewed and discussed with respect to their efficiency, versatility, and their possible practical transfer to the battery industry.
Entwicklung eines sensorintegrierten Verbundankers zur Überwachung der Befestigungssituation
Authors: Horn Sebastian , Gwosch Thomas , Matthiesen Sven
Published: March 2021

Der vorliegende Artikel stellt die Mechatronisierung eines herkömmlichen Verbundankersystems zur Integration einer sensorischen Zusatzfunktion für die zukünftige Überwachung von Befestigungssituationen vor. Hierzu wird die zentrale Fragestellung beantwortet, ob es möglich ist, Sensoren zur Zustandskontrolle der Befestigungssituation in ein chemisches Befestigungsmittel zu integrieren. Mit Erkenntnissen aus vorangegangenen Untersuchungen zu den Funktionsmechanismen und möglichen Designräumen in Verbundankern auf Vinylesterbasis werden Sensorelemente in solche Anker integriert. Um dies zu erreichen, werden relevante Schadensmechanismen ausgewählt, Randbedingungen für die Mechatronisierung eines Befestigungsmittels definiert und ein geeignetes physikalisches Messprinzip ausgewählt. Mit diesen Ergebnissen wird ein Sensorelement entworfen und in einen herkömmlichen Verbundanker auf Vinylesterbasis integriert. Dieses Sensorelement wird mit einer eigens hierfür entwickelten Messelektronik in einem Kalibrierprüfstand verifiziert. Durch die Validierung des Systems mit zentrischen Auszugsversuchen kann gezeigt werden, dass der integrierte kapazitive Abstandssensor die Detektion der Verbundankerverschiebung ermöglicht.
High‐Performance Asymmetric Supercapacitors Based on Monodisperse CuO@C Polyhedron Nanocomposites
Authors: Kim Hee Soo , Kang Min Seok , Heo Incheol , Yoo Won Cheol
Published: March 2021

Herein, CuO nanocrystals spatially embedded inside carbon polyhedron (CuO@C) derived via morphology‐preserved transformation of metal–organic frameworks (MOFs) are utilized for high‐performance asymmetric supercapacitors (SCs). Using a conventional MOF (several micrometers in size), pore‐filling with polymer inside MOF (polymer@MOF) via vapor‐phase polymerization (VPP) process was achieved that amount of polymer used for VPP can be readily adjusted to control the carbon content of CuO@C after thermolysis and subsequent oxidation processes. When monodisperse and nano‐sized MOF is used for CuO@C (denoted as nCuO@C_1), it presents superior electrochemical performance because monodispersity and smaller size reduce interfacial resistance and promote mass‐transport property, respectively. Asymmetric SC of nCuO@C_1 with carbon sphere (CS) as a counter electrode presents excellent energy density of 55.47 Wh/kg and long‐term stability of 88.7% at 5000 cycles, comparable to the best MO‐based asymmetric SCs derived from MOFs.
An interactive user interface for a structural analysis software using computer graphics techniques in MATLAB
Authors: C. Lopes Pedro , L. Rangel Rafael , Martha Luiz F.
Published: March 2021

This paper presents an interactive graphics tool for the structural analysis of one‐dimensional element models, such as trusses, frames, and grillages. The focus is on the creation of a graphical user interface for a previously developed analysis solver. This graphical interface is entirely implemented in the MATLAB environment and features intuitive resources so that modeling and verification of results become easy tasks for students and engineers. The management of mouse events and the adopted solutions to basic computer graphics issues that arise from interactive modeling in two‐dimensional and three‐dimensional canvases are discussed, including the strategies to pick objects in spatial coordinates and to identify crossing elements. The result is a new educational software that proved to be a very useful application in structural analysis and introductory computer graphics courses for engineering. The article also presents examples of using the software as an educational tool.
ZNF667 attenuates leukocyte‐endothelial adhesion via downregulation of P‐selectin in skin flap following remote limb ischemic preconditioning
Authors: Chen Zhuang , Liu Haifen , Li Yuanbin , Zhou Zhangfu , Qiu Jizhe , Tang Yi , Cui Taotao
Published: March 2021

We assessed the effects and potential mechanism of romote ischemic preconditioning (RIPC) on leukocytes‐endothelium cell adhesion in the flap microvessel after ischemia‐reperfusion (I/R) injury. Eight hours after reperfusion, edema and intravascular leukocyte aggregation were reduced and microvessels were more obvious in the group with superficial inferior epigastric artery (SIEA) perforator flap (SIEA‐flap) subjected to RIPC than in the I/R group. Zinc finger protein 667 (ZNF667) was significantly increased but P‐selectin was decreased in the flaps subjected to RIPC, compared to those in the I/R group. The low expression of P‐selectin was associated with ZNF667 expression and activation in human dermal microvascular endothelial cells in response to hypoxic preconditioning. ZNF667 bound to the P‐selectin promoter region, suppressing its transcription through a special core sequence. The ablation of P‐selectin by small interfering RNA effectively prevented the leukocytes‐endothelium cell adhesion effect of ZNF667‐knockdown. ZNF667 upregulation attenuates leukocyte‐endothelial cell adhesion by negatively regulating the expression of P‐selectin in SIEA‐flap subjected to RIPC.
Salmonella osteomyelitis complicating aseptic osteonecrosis: Don’t forget about the antiphospholipid syndrome
Authors: Daoud Fatma , Rachdi Imène , Frikha Olfa , Ben Salah Mohamed , Charaa Soumaya , Zoubeidi Hana , Somai Mehdi , Hadhri Khaled , Kooli Mondher , Chammakhi Chiraz , Boussema Fatma
Published: March 2021

Osteonecrosis in antiphospholipid syndrome is a diagnostic challenge for clinicians. Early diagnosis and intervention are important for better prognosis.
Case report of a pseudo‐isodicentric chromosome 9 resulting in mosaic trisomy 9
Authors: Beaudry Sarah M. , Shchelochkov Oleg , Trapane Pamela , Darbro Benjamin , Nagy Jaime M. W.
Published: March 2021

Due to the variable presentation of mosaic chromosomal abnormalities, cases such as this are needed to define the phenotypic spectrum. It also highlights the importance of chromosome analysis to identify structural abnormalities that result in aneuploidy.
Cytopathology of bronchoalveolar lavages in COVID‐19 pneumonia: A pilot study
Authors: Canini Valentina , Bono Francesca , Calzavacca Paolo , Capitoli Giulia , Foti Giuseppe , Fraggetta Filippo , Galimberti Stefania , Gianatti Andrea , Giani Marco , Nasr Ahmed , Paciocco Giuseppe , Pagni Fabio , Rona Roberto , L’Imperio Vincenzo
Published: March 2021

BACKGROUND

Bronchoalveolar lavage (BAL) in patients with severe coronavirus disease 2019 (COVID‐19) may provide additional and complementary findings for the management of these patients admitted to intensive care units (ICUs). This study addresses the cytological features of the infection and highlights the more influential inflammatory components. The correlation between pathological variables and clinical data is also analyzed.

METHODS

The authors performed a retrospective analysis of the cytopathological features of BAL in 20 COVID‐19 patients and 20 members of a matched cohort from a critical ICU who had acute respiratory distress syndrome caused by other pulmonary conditions.

RESULTS

A comparison of the controls (n = 20) and the COVID‐19 patients (n = 20) revealed that the latter had a higher neutrophil count (median, 63.8% of the cell count) with lower percentages of macrophages and lymphocytes. An increase in the expression of CD68‐positive, monocytic multinucleated giant cells (MGCs) was reported; megakaryocytes were not detected on CD61 staining. Perls staining showed isolated elements. In situ RNA analysis demonstrated scattered chromogenic signals in type II pneumocytes. An ultrastructural analysis confirmed the presence of intracytoplasmic vacuoles containing rounded structures measuring 140 nm in diameter (putative viral particles). In COVID‐19 patients, the clinicopathological correlation revealed a positive correlation between lactate dehydrogenase values and MGCs (r = 0.54).

CONCLUSIONS

The analysis of BAL samples might be implemented as a routine practice for the evaluation of COVID‐19 patients in ICUs in the appropriate clinical scenario. Additional studies using a larger sample size of patients who developed COVID‐19 during the second wave of the epidemic in the autumn of 2020 are needed to further support our findings.
Clinical validation of a novel bioluminescence imaging technology for aiding the assessment of carious lesion activity status
Authors: Pitts Nigel , Shanks Neil , Longbottom Christopher , Willins Marjory , Vernon Bruce
Published: March 2021

Objectives

Clinical validation of a bioluminescence imaging system (Cis) as measured by the level of agreement between clinician visual and tactile assessment of carious lesion presence and activity and the presence/absence of elevated luminescence on a tooth surface determined from intraoral image mapping.

Materials and Methods

This was a regulatory clinical study designed in consultation with the FDA. The design was a prospective, five‐investigator, nonrandomized, post‐approval, clinical study utilizing the Cis to provide images of elevated calcium ion concentration (indicative of active demineralization) on tooth surfaces via use of a photoprotein. Imaged teeth were identified as “sound” or having “active lesions.” Images were scored independently for luminescence.

Results

A total of 110 participants aged 7–74 years were imaged. Of the 90 teeth assessed as “sound,” 88 were deemed to show no luminescence by the reviewing investigator, a negative percentage agreement of 97.8% (significantly >50% agreement [p < .0001]; one‐sided 97.5% confidence interval [CI]: 0.9220). Of the 86 teeth initially assessed as having an “active lesion,” 78 were deemed to show luminescence by the reviewing investigator, a positive percentage agreement of 90.7% (significantly >50% agreement [p < .0001]; 97.5% CI: 0.8249). There were no patient‐related adverse events.

Conclusions

Results show, with a high level of agreement, that Cis can differentiate tooth surfaces clinically identified as involving active enamel lesions (ICDAS code 2/3), from sound sites (biochemically equivalent to inactive lesions) and that the system is safe for clinical use.
Flame‐Retardant, Highly Conductive, and Low‐Temperature‐Resistant Organic Gel Electrolyte for High‐Performance All‐Solid Supercapacitors
Authors: Wang Jijun , Li Xuelin , Yang Jianbo , Sun Weigang , Ban Qing , Gai Ligang , Gong Yingying , Xu Zhen , Liu Libin
Published: March 2021

Traditional liquid electrolytes are volatile, flammable, and easy to leak, which makes the energy storage device easy to burn and explode in the case of overcharge and short circuit. Here, by utilizing the active P−H bond of a flame retardant (DOPO) to graft onto the polymer chain, flame‐retardant organic gel electrolytes were fabricated to address these issues. The gel electrolyte had good ionic conductivity of 4 mS cm−1 at 20 °C and good flame retardant ability. By changing the molar ratio of the monomers and the salt concentrations, the mechanical strength of the gel electrolyte could be adjusted (maximum stress≈28 KPa, maximum strain≈305 %). The transport mechanism of lithium ions in the gel polymer electrolyte was proposed. The gel electrolyte‐assembled supercapacitor (SC) possessed better electrochemical properties than that of SC assembled by liquid electrolyte. Importantly, the gel‐based SC remained basically unchanged under multiple bending cycles. Additionally, the gel electrolyte had good low‐temperature tolerance (0.1 mS cm−1 at −40 °C). The gel electrolyte‐assembled SC could work normally in the temperature range of −20 to 60 °C. The multiple advantages of gel electrolyte expand the applications in ionic conductor and energy storage devices.
Fractional CO2 laser‐assisted scar regeneration and repair: A review
Authors: Lei Ying , Gold Michael H. , Ouyang Hua‐Wei , Tan Jun
Published: March 2021

Hypertrophic scars are one of the more difficult problems to treat in our clinical practice. In this review, we cover our approach, from basic science research in our laboratory to the clinical theater on how we approach and treat these patients to improve cosmetic appearance and functional capabilities for patients suffering from hypertrophic scars.
A cell‐free bioassay for the detection of androgens
Authors: Cooper Elliot R. , Hughes Gillian , Kauff Alexia , Sutherland Emma , Ashley Zoe , Heather Alison K.
Published: March 2021

Androgens remain abused performance‐enhancing drugs in sports. Technologies based on mass spectrometry can detect all forms of androgens but fail if the androgen represents a novel structure. A bioassay detects androgens based on function rather than structure. To date, there has been limited adoption of cell‐based in vitro bioassays as a screening tool for nontargeted androgen detection because they require expert personnel and specialized equipment to perform. We now describe the development of a cell‐free version of an androgen in vitro bioassay. Stage 1 involved in vitro transcription/translation reactions (IVTT) using a DNA template encoding an enhancer/androgen response element (ARE) regulatory region upstream of a minimal promoter that drives expression of a reporter protein. The assay detected testosterone across the concentration range of 106.7 to 0.0144 ng/ml (3.7 × 10−7 to 5 × 10−11 M), with an EC50 of 6.63 ng/ml (23 nM). To reduce complexity, Stages 2–4 of development included just in vitro transcription (IVT) reactions, whereby the output was an RNA molecule. Stage 2 involved directly labelling the RNA molecule with fluorophore‐labelled nucleotide triphosphates, Stage 3 involved reverse transcription‐polymerase chain reaction (PCR) of the RNA molecule, and Stage 4 utilized an RNA aptamer, Mango II, as its RNA output. The Stage 4 product detected testosterone across the range of 106.7–0.0001 ng/ml (3.7 × 10−7 to 5 × 10−13 M), with an EC50 of 0.04 ng/ml (0.155 nM). Further to this, we show that the Stage 4 product can detect other androgenic molecules. Relative to cell‐based bioassays, the Stage 4 product is easy to perform and could be developed into a routine, high‐throughput, nontargeted androgen screen.
Diversity and characterization of bacterial communities of five co‐occurring species at a hydrothermal vent on the Tonga Arc
Authors: Lee Won‐Kyung , Juniper S. Kim , Perez Maëva , Ju Se‐Jong , Kim Se‐Joo
Published: March 2021

Host–symbiont relationships in hydrothermal vent ecosystems, supported by chemoautotrophic bacteria as primary producers, have been extensively studied. However, the process by which densely populated co‐occurring invertebrate hosts form symbiotic relationships with bacterial symbionts remains unclear. Here, we analyzed gill‐associated symbiotic bacteria (gill symbionts) of five co‐occurring hosts, three mollusks (“Bathymodiolus” manusensis, B. brevior, and Alviniconcha strummeri) and two crustaceans (Rimicaris variabilis and Austinograea alayseae), collected together at a single vent site in the Tonga Arc. We observed both different compositions of gill symbionts and the presence of unshared operational taxonomic units (OTUs). In addition, the total number of OTUs was greater for crustacean hosts than for mollusks. The phylogenetic relationship trees of gill symbionts suggest that γ‐proteobacterial gill symbionts have coevolved with their hosts toward reinforcement of host specificity, while campylobacterial Sulfurovum species found across various hosts and habitats are opportunistic associates. Our results confirm that gill symbiont communities differ among co‐occurring vent invertebrates and indicate that hosts are closely related with their gill symbiont communities. Considering the given resources available at a single site, differentiation of gill symbionts seems to be a useful strategy for obtaining nutrition and energy while avoiding competition among both hosts and gill symbionts.
Rhodium(III)‐Catalyzed Oxidative Intramolecular 1,1‐Oxyamination of Alkenes with Protected Amino Acids to Produce Oxazoloisoindole‐2,5‐diones
Authors: Takahashi Hiroto , Nagashima Yuki , Tanaka Ken
Published: March 2021

It has been established that an electron‐deficient bis(ethoxycarbonyl)‐substituted cyclopentadienyl (CpE) rhodium(III) complex catalyzes the oxidative intramolecular 1,1‐oxyamination of alkenes with N‐benzoyl amino acids to produce oxazoloisoindole‐2,5‐diones. Experimental and theoretical mechanistic studies revealed that this oxidative 1,1‐oxyamination proceeds via not the aza‐Wacker reaction but the formation of a rhoda(III)oxazolidine initiated by the carboxylic acid‐directed N−H bond cleavage.
Impact of Soret and Dufour on bioconvective flow of nanofluid in porous square cavity
Authors: Balla Chandra Shekar , Ramesh Alluguvelli , Kishan Naikoti , Rashad Ahmed Mohamed
Published: March 2021

This article addresses the bioconvection in a porous cavity associated with Soret and Dufour effects. The bioconvective flow in a porous medium is based on Hillesdon and Pedley's model and is governed by nonlinear partial differential equations. These equations are transformed into a dimensionless form with suitable nondimensional parameters. The finite element method is employed to solve the dimensionless equations. The outcomes of the study are presented by streamlines, temperature distributions, isoconcentrations of solute, nanoparticles, and microorganisms. Furthermore, the tendency of average Nusselt number and average Sherwood number and the influence of Soret parameter, Dufour parameter, Peclet number, and bioconvective Rayleigh number is interpreted. Thermophoresis and Soret number show a strong effect on the concentration of nanoparticles. Brownian motion and thermophoresis exhibit a significant effect on the density distributions of microorganisms. The novelty of the paper is to combine the effects of Soret–Dufour and oxytactic bioconvection. The present study can be useful in the following applications: microbial‐enhanced oil recovery, toxin removal, antibiotics, and modeling of microfluidic devices.
Hepatoprotective effect of the tyrosine kinase inhibitor nilotinib against cyclosporine‐A induced liver injury in rats through blocking the Bax/Cytochrome C/caspase‐3 apoptotic signaling pathway
Authors: Serrya Marwa S. , Nader Manar A. , Abdelmageed Marwa E.
Published: March 2021

Cyclosporine‐A (CsA) is a powerful immunosuppressive agent and hepatotoxicity results from CsA treatment. This study aimed to elucidate the effectiveness of tyrosine kinase inhibitor nilotinib against CsA‐induced hepatotoxicity and the underlying molecular mechanisms. Male Sprague‐Dawley rats were allocated into four groups and received drugs for 28 days as follows: Control group: received vehicle, Nilotinib group: received nilotinib (20 mg/kg orally), CsA group: received CsA by subcutaneous injection (20 mg/kg daily), CsA‐nilotinib: received nilotinib and CsA. Serum lactate dehydrogenase (LDH), liver function biomarkers, hepatic levels of oxidative stress biomarkers, nuclear factor erythroid‐2 like‐2 (Nrf2), total antioxidant capacity (TAC), interleukin‐2 (IL‐2), IL‐1β, IL‐6, and cytochrome‐C were assessed. Additionally, the protein levels and mRNA expression of Bcl2 associated X protein (Bax), caspase‐3, nuclear factor‐κB (NF‐κB), hemoxygenase‐1 (HO‐1) were measured. Moreover, liver tissues were assessed histopathologically using hematoxylin–eosin and Masson trichrome stain. Nilotinib treatment decreased serum LDH, alanine aminotransferase, aspartate aminotransferase, and γ‐glutamyltransferase (γ‐GT), hepatic malondialdehyde, and cytochrome‐C. It also increased superoxide dismutase, reduced glutathione, glutathione reductase, glutathione peroxidase, glutathione‐S‐transferase (GST), TAC, and Nrf2 compared to CsA‐injected rats. In addition, nilotinib decreased NF‐κB, IL‐1β, IL‐6, Bax, and caspase‐3, while elevated IL‐2 and immunoexpression of HO‐1. Additionally, mRNA expression of Bax and caspase‐3 was elevated and that of HO‐1 and inhibitory protein κB‐α was reduced in the nilotinib‐treated group. Moreover, nilotinib significantly attenuated CsA‐induced histopathological alterations. Nilotinib may have a promising role as a hepato‐protective through its antiapoptotic, antioxidant, and anti‐inflammatory effects.
Cost saving, patient centered algorithm for progenitor cell mobilization for autologous hematopoietic cell transplantation
Authors: Sanikommu Srinivasa Reddy , Reese Emily S. , He Jiaxian , Lee Carlos , Ai Jing , Butler Candace M. , Jacobs Ryan , Hu Bei , Atrash Shebli , Trivedi Jigar , Bhutani Manisha , Voorhees Peter , Usmani Saad Z. , Ghosh Nilanjan , Fasan Omotayo , Druhan Lawrence J. , Symanowski James , Copelan Edward A. , Avalos Belinda R.
Published: March 2021

Administration of plerixafor with granulocyte‐colony stimulating factor (G‐CSF) mobilizes CD34+ cells much more effectively than G‐CSF alone, but cost generally limits plerixafor use to patients at high risk of insufficient CD34+ cell collection based on low peripheral blood (PB) CD34+ counts following 4 days of G‐CSF. We analyzed costs associated with administering plerixafor to patients with higher day 4 CD34+ cell counts to decrease apheresis days and explored the use of a fixed split dose of plerixafor instead of weight‐based dosing. We analyzed 235 patients with plasma cell disorders or non‐Hodgkin's lymphoma who underwent progenitor cell mobilization and autologous hematopoietic cell transplantation (AHCT) between March 2014 and December 2017. Two hundred ten (89%) received G‐CSF plus Plerixafor and 25 (11%) received G‐CSF alone. Overall, 180 patients (77%) collected in 1 day, 53 (22%) in 2 days and 2 (1%) in 3 days. Based on our data, we present a probabilistic algorithm to identify patients likely to require more than one day of collection using G‐CSF alone. CD34+ cell yield, ANC and platelet recovery were not significantly different between fixed and standard dose plerixafor. Plerixafor enabled collection in 1 day and with estimated savings of $5000, compared to patients who did not receive plerixafor and required collection for three days. While collection and processing costs and patient populations vary among institutions, our results suggest re‐evaluation of current algorithms.
Measuring potential effects of the developmental burden associated with the vertebrate notochord
Authors: Fujimoto Satoko , Yamanaka Kaori , Tanegashima Chiharu , Nishimura Osamu , Kuraku Shigehiro , Kuratani Shigeru , Irie Naoki
Published: March 2021

The notochord functions primarily as a supporting tissue to maintain the anteroposterior axis of primitive chordates, a function that is replaced entirely by the vertebral column in many vertebrates. The notochord still appears during vertebrate embryogenesis and plays a crucial role in the developmental pattern formation of surrounding structures, such as the somites and neural tube, providing the basis for the vertebrate body plan. The indispensable role of the notochord has often been referred to as the developmental burden and used to explain the evolutionary conservation of notochord; however, the existence of this burden has not been successfully exemplified so far. Since the adaptive value of target tissues appears to result in the evolutionary conservation of upstream structures through the developmental burden, we performed comparative gene expression profiling of the notochord, somites, and neural tube during the mid‐embryonic stages in turtles and chicken to measure their evolutionary conservation. When compared with the somites and neural tube, overall gene expression profiles in the notochord showed significantly lower or merely comparable levels of conservation. However, genes involved in inductive signalings, such as the sonic hedgehog (Shh) cascade and the formation of functional primary cilia, showed relatively higher levels of conservation in all the three structures analyzed. Collectively, these results suggest that shh signals are critical as the inductive source and receiving structures, possibly constituting the inter‐dependencies of developmental burden.
A sub‐regional approach to the influence analysis of teleconnection patterns on precipitation in Calabria (southern Italy)
Authors: Caroletti Giulio N. , Coscarelli Roberto , Caloiero Tommaso
Published: March 2021

In this study, the problem of determining, with an adequate statistical significance, the relationship between teleconnection pattern indices and precipitation at climatological time scales has been addressed through a novel technique based on a rainfall zonation, by means of creating a regional precipitation database for a whole‐region correlation approach. Pearson correlation was performed to evaluate the mesoscale influence on precipitation in the Calabria region over the 1951–2010 time period, by means of a database of 79 rain gauges, divided in five Rainfall Zones (RZs) and seven teleconnection pattern indices relevant to the Mediterranean region, searching where results were significant (significance level < 0.05) and with an absolute correlation value higher than a prefixed threshold equal to 0.2. The Calabria region was chosen as it is located in the centre of the Mediterranean area, which constitutes a hot spot for climate change, and because it is equipped with a high‐density, long‐time series of precipitation gauge network, recently validated and homogenized. Correlation analysis between seasonal teleconnection indices and seasonal cumulated precipitation showed that the Western Mediterranean Oscillation and the East Atlantic/West Russian patterns were the most relevant teleconnections over all Calabria. Correlations of 3‐month averaged teleconnection indices versus monthly precipitation showed that the Mediterranean and Western Mediterranean Oscillations produce most significant results with correlation values higher than 0.2, with East Atlantic pattern a third close. Comparison between monthly teleconnection indices and monthly cumulated precipitation indicate that all modes of variability taken into account share a similarly weak correlation. Comparing the rainfall zone‐based study and the technique of averaging individual stations results post‐correlation, it was shown that on average only 43% of the stations would produce useful correlations, while the novel technique used all the valid and available station data, resulting in statistically more robust findings.
Retreat dynamics of the eastern sector of the British–Irish Ice Sheet during the last glaciation
Authors: Evans David J. A. , Roberts David H. , Bateman Mark D. , Clark Chris D. , Medialdea Alicia , Callard Louise , Grimoldi Elena , Chiverrell Richard C. , Ely Jeremy , Dove Dayton , Ó Cofaigh Colm , Saher Margot , Bradwell Tom , Moreton Steven G. , Fabel Derek , Bradley Sarah L.
Published: March 2021

The findings of BRITICE‐CHRONO Transect 2 through the North Sea Basin and eastern England are reported. We define ice‐sheet marginal oscillation between ~31 and 16 ka, with seven distinctive former ice‐sheet limits (L1–7) constrained by Bayesian statistical analysis. The southernmost limit of the North Sea Lobe is recorded by the Bolders Bank Formation (L1; 25.8–24.6 ka). L2 represents ice‐sheet oscillation and early retreat to the northern edge of the Dogger Bank (23.5–22.2 ka), with the Garret Hill Moraine in north Norfolk recording a significant regional readvance to L3 at 21.5–20.8 ka. Ice‐marginal oscillations at ~26–21 ka resulted in L1, L2 and L3 being partially to totally overprinted. Ice‐dammed lakes related to L1–3, including Lake Humber, are dated at 24.1–22.3 ka. Ice‐sheet oscillation and retreat from L4 to L5 occurred between 19.7 and 17.3 ka, with grounding zone wedges marking an important transition from terrestrial to marine tidewater conditions, triggered by the opening of the Dogger Lake spillway between 19.9 and 17.5 ka. L6 relates to ice retreat under glacimarine conditions and final ice retreat into the Firth of Forth by 15.8 ka. L7 (~15 ka) represents an ice retreat from Bosies Bank into the Moray Firth.
In situ high temperature Raman and DFT analysis of cerium fluoride and oxyfluoride structures in molten FLiNaK
Authors: Cui Rongrong , Wang Chenyang
Published: March 2021

In order to investigate the species in the FLiNaK–CeF3 and FLiNaK–CeF3–Li2O melts, in situ high temperature Raman spectroscopy was used with the aid of density functional theory (DFT) calculation. In molten FLiNaK, the CeF63− octahedra affected by alkali cations were identified to be the predominan species. Binuclear cerium oxyfluoride anions Ce2OF84− and Ce2OF106− were formed after adding O2− into the molten FLiNaK‐CeF3 (20 mol%) mixtures. Both of these two species were predicted to have Ce−O−Ce geometries with two CeF4/CeF5 moieties bridged by a single oxygen atom.
Prosocial skills development in children and social value creation during COVID‐19
Authors: Arslan Ahmad , Haapanen Lauri , Tarba Shlomo
Published: March 2021

Development of prosocial skills in children in their middle childhood and the role of computer games is analyzed in our case study based on an entrepreneurial venture (School of Gaming, Oulu). This venture was launched almost at the same time as the COVID‐19 pandemic hit the globe. It has operated successfully during COVID‐19, not only in Finland but also has expanded to Indonesia in this limited time period. It created social value by offering the children a possibility to be with their friends during the lockdown as well as develop skills like empathy, sharing, and trust. The case study further revealed that affordable pricing, the use of professional gaming instructors and adaptation played an important role in organizational success during this tough time period.
Attachment styles moderate customer responses to frontline service robots: Evidence from affective, attitudinal, and behavioral measures
Authors: Pozharliev Rumen , De Angelis Matteo , Rossi Dario , Romani Simona , Verbeke Willem , Cherubino Patrizia
Published: March 2021

Despite the growing application of interactive technologies like service robots in customer service, there is limited understanding about how customers respond to interactions with frontline service robots compared to those with frontline human employees. Moreover, it is unclear whether all customers respond to the interaction with frontline service robots in the same way. Our research looks at how individual differences in social behaviors, specifically in customers' attachment styles, influence three types of customer responses: affective responses (experienced pleasantness), attitudinal responses (perceived empathy, satisfaction), and behavioral responses (word‐of‐mouth). Three experimental studies reveal that customers with low (vs. high) scores on anxious attachment style (AAS) measures respond more negatively to frontline service robot (compared to a frontline human agent). We investigate alternative explanations for these findings, such as robots' level of anthropomorphism and we show that human‐likeness features such as voice type and level of human‐like physical appearance, cannot explain our findings. Our results indicate that for low‐AAS customers replacing frontline human service agent with frontline robot undermines customer attitude and behavioral responses to service robots, leading to possible implications on customer segmentation, targeting, and marketing communication.
Reward‐based or meaningful gaming? A field study on game mechanics and serious games for sustainability
Authors: Whittaker Lucas , Russell‐Bennett Rebekah , Mulcahy Rory
Published: March 2021

Despite investigating digital gaming for commercial purposes, less scholarly attention exists on digital gaming for societal purposes such as sustainability (“serious games”). The current study investigates whether a serious game can enhance sustainability marketing outcomes, including knowledge, value‐in‐behavior, and behavioral intentions longitudinally (pre‐gameplay to post‐gameplay). Further, the study seeks to understand the influence of reward‐based and meaningful game mechanics on these sustainability marketing outcomes. We recruited 387 participants for a week‐long field study using a serious game which encourages household energy conservation. The findings show that the serious game significantly increased sustainability knowledge, value‐in‐behavior, and sustainable behavioral intention after one week. Reward‐based game mechanics (badges and trophies) significantly influenced sustainability knowledge and indirectly influenced value‐in‐behavior via sustainability knowledge, whereas reward‐based (points) and meaningful (educational messages) game mechanics had little impact. The results empirically support the conceptual model theorization—underpinned by a “do–learn–feel” behavioral learning approach—which possessed superior fit to a “do–feel–learn” rival model. This study provides novel insights regarding eliciting value‐in‐behavior longitudinally within serious games. Our multidimensional approach to assessing reward‐based game mechanics extends prior studies and suggests that higher‐tier rewards are more influential than lower‐tiered rewards to achieve sustainability marketing outcomes. We further demonstrate that reward‐based game mechanics outperform meaningful game mechanics at influencing desired outcomes, challenging existing gaming literature.
Earnings management, capital structure, and the role of corporate governance: Evidence from sub‐Saharan Africa
Authors: Okyere Sarah Anobil , Fiador Vera , Sarpong‐Kumankoma Emmanuel
Published: March 2021

This study investigates the effect of earnings management and corporate governance on the capital structure decision of firms. We utilized data of non‐financial firms from selected sub‐Saharan African countries over the period 2008 to 2018. Both fixed and random effect regressions were the methods of analysis employed. Our findings indicate that earnings management is associated with low equity usage and by implication, high leverage levels among firms. Importantly, the presence of corporate governance was found to mitigate the high leverage implication of earnings management. We therefore recommend an improvement in corporate governance practices to minimize the occurrence of earnings management.
Trading off spatio‐temporal properties in 3D high‐speed fMRI using interleaved stack‐of‐spirals trajectories
Authors: Riemenschneider Bruno , Akin Burak , LeVan Pierre , Hennig Jürgen
Published: March 2021

Purpose

Highly undersampled acquisitions have been proposed to push the limits of temporal resolution in functional MRI. This contribution is aimed at identifying parameter sets that let the user trade‐off between ultra‐high temporal resolution and spatial signal quality by varying the sampling densities. The proposed method maintains the synergies of a temporal resolution that enables direct filtering of physiological artifacts for highest statistical power, and 3D read‐outs with optimal use of encoding capabilities of multi‐coil arrays for efficient sampling and high signal‐to‐noise ratio (SNR).

Methods

One‐ to four‐shot interleaved spherical stack‐of‐spiral trajectories with repetition times from 96 to 352 ms at a nominal resolution of 3 mm using different sampling densities were compared for image quality and temporal SNR (tSNR). The one‐ and three‐shot trajectories were employed in a resting state study for functional characterization.

Results

Compared to a previously described single‐shot trajectory, denser sampled trajectories of the same type are shown to be less prone to blurring and off‐resonance vulnerability that appear in addition to the variable density artifacts of the point spread function. While the multi‐shot trajectories lead to a decrease in tSNR efficiency, the high SNR due to the 3D read‐out, combined with notable increases in image quality, leads to superior overall results of the three‐shot interleaved stack of spirals. A resting state analysis of 15 subjects shows significantly improved functional sensitivity in areas of high off‐resonance gradients.

Conclusion

Mild variable‐density sampling leads to excellent tSNR behavior and no increased off‐resonance vulnerability, and is suggested unless maximum temporal resolution is sought.
Structure‐preserving space‐time discretization of large‐strain thermo‐viscoelasticity in the framework of GENERIC
Authors: Schiebl Mark , Betsch Peter
Published: March 2021

Large‐strain thermo‐viscoelasticity is described in the framework of GENERIC. To this end, a new material representation of the inelastic part of the dissipative bracket is proposed. The bracket form of GENERIC generates the governing equations for large‐strain thermo‐viscoelasticity including the nonlinear evolution law for the internal variables associated with inelastic deformations. The GENERIC formalism facilitates the free choice of the thermodynamic variable. In particular, one may choose (i) the internal energy density, (ii) the entropy density, or (iii) the absolute temperature as the thermodynamic variable. A mixed finite element method is proposed for the discretization in space which preserves the GENERIC form of the resulting semi‐discrete evolution equations. The GENERIC‐consistent space discretization makes possible the design of structure‐preserving time‐stepping schemes. The mid‐point type discretization in time yields three alternative schemes. Depending on the specific choice of the thermodynamic variable, these schemes are shown to be partially structure‐preserving. In addition to that, it is shown that a slight modification of the mid‐point type schemes yields fully structure‐preserving schemes. In particular, three alternative energy‐momentum‐entropy consistent schemes are devised associated with the specific choice of the thermodynamic variable. Numerical investigations are presented which confirm the theoretical findings and shed light on the numerical stability of the newly developed schemes.