bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment abandonment and refusal among children with central nervous system tumors in Jordan
Authors: Amayiri Nisreen , Bouffet Eric
Published: May 2021

Background

Treatment abandonment and refusal are reported to contribute significantly to poor survival of children with cancer in low‐ and middle‐income countries. We aimed to assess this phenomenon among children diagnosed with central nervous system (CNS) tumors in Jordan.

Methods

We retrospectively reviewed the medical charts of children <18 years diagnosed with CNS tumors (2010–2020). Patients who abandoned or refused part of treatment were reviewed for their clinical characteristics, social circumstances, and possible reasons. We excluded patients referred for second opinion, radiotherapy only, or who traveled abroad for treatment.

Results

Four hundred seventy‐three Jordanian children were identified; 12 families (2.5%) abandoned treatment, and 15 refused part of therapy (3%). Most patients were females (67%) and most had good or moderate performance status (89%). Most families (93%) lived within 2 hours from King Hussein Cancer Center. Most parents were university graduates (71%) and all fathers were employed, while 71% of mothers were housewives. The most common reasons to abandon or refuse therapy were treatment intensity in view of poor tumor outcome or bad quality of life, conflicting recommendations from other health care providers, “personal beliefs” against chemotherapy, and preference to use alternative medicine.

Conclusions

Treatment abandonment and refusal in Jordanian children with CNS tumors is low. Universal cancer insurance, high level of education in the country, centralized cancer care in one institution, and the twinning program likely contributed to our low incidence. Improving knowledge on CNS tumors and better community rehabilitation and supportive services may help further decrease the abandonment and treatment refusal rate.
Naxitamab combined with granulocyte‐macrophage colony‐stimulating factor as consolidation for high‐risk neuroblastoma patients in complete remission
Authors: Mora Jaume , Castañeda Alicia , Gorostegui Maite , Santa‐María Vicente , Garraus Moira , Muñoz Juan Pablo , Varo Amalia , Perez‐Jaume Sara , Mañe Salvador
Published: May 2021

Background

Naxitamab is a humanized anti‐disialoganglioside (GD2) monoclonal antibody approved for treatment of bone/bone marrow refractory high‐risk neuroblastoma (HR‐NB). Compassionate use (CU) expanded access program at Hospital Sant Joan de Deu permitted treatment of patients in complete remission (CR). We here report the survival, toxicity, and relapse pattern of patients in first or second CR treated with naxitamab and sargramostim (GM‐CSF).

Procedure

Seventy‐three consecutive patients with HR‐NB (stage M at age >18 months or MYCN‐amplified stages L1/L2 at any age) were treated in first or second CR. Treatment comprised five cycles of subcutaneous (SC) GM‐CSF for 5 days at 250 μg/m2/day (days −4 to 0), followed by naxitamab + SC GM‐CSF for 5 days at 500 μg/m2/day (days 1–5). Naxitamab was infused over 30 minutes at 3 mg/kg/day, days 1, 3, and 5, outpatient.

Results

Fifty‐five patients were in first CR and 18 in second CR. Seventeen patients had MYCN‐amplified NB and 11 detectable minimal residual disease in the bone marrow. Fifty‐eight (79.5%) patients completed therapy. Four (5%) experienced grade 4 toxicities and 10 (14%) early relapse. Three‐year event‐free survival (EFS) 58.4%, 95% CI = (43.5%, 78.4%) and overall survival (OS) 82.4%, 95% CI = (66.8%, 100%). First CR patients 3‐year EFS 74.3%, 95% CI = (62.7%, 88.1%), and OS 91.6%, 95% CI = (82.4%, 100%). EFS is significantly different between first and second CR (p = .0029). The pattern of relapse is predominantly (75%) of an isolated organ, mainly bone (54%). Univariate Cox models show prior history of relapse as the only statistically significant predictor of EFS but not OS.

Conclusions

Consolidation with naxitamab and GM‐CSF resulted in excellent survival rates for HR‐NB patients in CR.
Effect of using multiwall carbon nanotube reinforced epoxy adhesive in enhancing glass fiber reinforced polymer composite through cocure manufacturing technique
Authors: Dhilipkumar Thulasidhas , Rajesh Murugan
Published: May 2021

The high‐performance epoxy‐based cocure manufacturing technique has been used to join composite structures such as wings, frames, and ribs in aerospace applications. The present study aims to examine the influence of multiwall carbon nanotubes (MWCNTs) addition on mechanical and free vibrational behavior of glass fiber reinforced polymer composites fabricated through cocure manufacture technique. The experimental results revealed that the addition of 1 wt.% of MWCNTs enriched the tensile and flexural properties of cocured composites by 27.8% (344 Mpa) and 26.16% (379.12 Mpa), respectively. Shear analysis depicted that 0.25 wt.% MWCNT reinforcement significantly enhanced the shear strength of cocured lap joints by 63.8% (16.79 MPa). The scanning electron microscopy and atomic force microscopy indicated that homogenous dispersion of MWCNTs enriched the interfacial bonding, deviated the crack path, and formed uneven surfaces. A comparison between the failure mode of neat and modified adhesive demonstrated the effective presence of MWCNTs in changing the adhesive failure mode of cocured composite to cohesive. Thus, it enhanced the failure strength of cocured composites. The experimental free vibrational analysis affirmed that addition of 1 wt.% MWCNTs enhanced the fundamental natural frequency whereas, lower wt.% MWCNT addition increased the cocured composites' inherent damping due to higher‐level formation of agglomeration area in the composite. Thus, it increased the stress level and minimized the bonding between fiber and matrix.
Chemical characterisation of Pelargonium sidoides root based on LC‐QToF‐MS non‐target screening strategies
Authors: Panara Anthi , Aalizadeh Reza , Thomaidis Nikolaos S.
Published: May 2021

Introduction

Pelargonium sidoides is a member of the Geraniaceae family and it originates from the coastal regions of South Africa. In the last decades, Pelargonium sidoides root has been subjected to several surveys due to the assertion of its health benefits, such as the relief of symptoms of acute bronchitis, common cold and acute rhinosinusitis. Many studies have been conducted to reveal its naturally occurring bioactive chemicals, yet no wide‐scope chemical characterisation strategies have been done using mass spectrometry.

Objective

This research aimed to comprehensively characterise the chemical profile of Pelargonium sidoides root via high‐resolution mass spectrometry.

Methodology

The Pelargonium sidoides root was extracted by a mixture of methanol: water in the proportion of 80:20. The extraction procedure included vortexing, shaking as well as the use of an ultrasound sonication bath under 40°C. After centrifugation, the supernatant was evaporated to dryness. The dry residue was reconstituted with a mixture of methanol/water (50:50, v/v), filtered and injected into an ultra‐high‐pressure liquid chromatography‐quadruple time‐of‐flight mass spectrometer.

Results

Overall, 33 compounds were identified in the root using suspect and non‐target screening. These compounds were originated from different classes of compounds such as amino acids, phenolic acids, α‐hydroxy‐acids, vitamins, polyphenols, flavonoids, coumarins, coumarins glucosides, coumarin sulphates and nucleotides. Quantitative results were provided for the identified compounds, where their reference standards were available.

Conclusion

Some important compounds were elucidated, belonging to different classes of compounds such as antioxidants (coumarins and phenolic compounds), amino acids, nucleotides and vitamins revealing the importance of the bioactive content of this root.
Thermal processing of a degradable carboxylic acid‐functionalized polycarbonate into scaffolds for tissue engineering
Authors: Murthy N. Sanjeeva , Shultz Robert B. , Iovine Carmine P. , Kohn Joachim
Published: May 2021

Degradable polymers are often desirable for the fabrication of medical implants, but thermal processing of these polymers is a challenge. We describe here how these problems can be addressed by discussing the extrusion of fibers and injection molding of bone pins from a hydrolytically degradable tyrosine‐derived polycarbonate. Our initial attempts produced fibers and pins with bubbles, voids, and discoloration and resulted in the formation of large polymer plugs that seized screws and blocked extruder dies. The material and process parameters that contribute to these issues were investigated by studying the physical and chemical changes that occur during processing. Differential scanning calorimetry and thermogravimetric analysis combined with IR analysis showed that residual moisture and solvents in conjunction with heat cause degradation and crosslinking as indicated by gel permeation chromatography. Rheology and melt flow index measurements were useful in characterizing the extent of dependence of polymer viscosity on temperature and molecular weight. With these insights, we could process our polymer into fibers and rods by controlling residual moisture, time, and temperature and by adjusting processing parameters in real time. The systematic approach described here is applicable to other degradable polymers that are difficult to process.
Outcomes of patients with COVID‐19 after inpatient rehabilitation
Authors: Groah Suzanne L. , Pham Cynthia T. , Rounds Amanda K. , Semel Jennifer J.
Published: May 2021

Background

Rehabilitation outcomes of patients with coronavirus disease 2019 (COVID‐19) are unknown.

Objective

To describe patients with COVID‐19 who are undergoing inpatient rehabilitation and their rehabilitation outcomes.

Design

Retrospective observational cohort study of all inpatients from a rehabilitation hospital between March 1 and September 30, 2020.

Setting

Inpatient rehabilitation hospital.

Patients

Among all inpatients, inclusion criteria are: ≥18 years of age and admission and discharge within the study time frame. The initial search yielded 920 patients; 896 met the inclusion criteria. Subjects were stratified by COVID‐19 status and rehabilitation impairment.

Main Outcome Measures

Data included age, gender, body mass index (BMI), length of stay (LOS), discharge location, and functional ability in self‐care and mobility (FA‐SC, FA‐Mob). One‐sample t‐tests were used to assess the difference of age, BMI, LOS, FA‐SC, FA‐Mob, and FA efficiency between COVID‐19+ and COVID‐19− patients.

Results

COVID‐19+ patients were younger (59.4 years vs 62.9 years; t[894] = −2.05, p = .04) with a higher mean BMI (32 vs 28; t[894] = 3.51, p < .01) than COVID‐19− patients. COVID‐19+ patients had equivalent or superior improvements in FA‐SC and FA‐Mob, functional change efficiency, and LOS relative to COVID‐19− patients. When medically complex patients were compared, those with COVID‐19 had greater FA‐SC and FA‐Mob efficiencies than COVID‐19− patients. COVID‐19+ patients had similar rates of return to the community.

Conclusions

Patients with COVID‐19 who meet the admission criteria for inpatient rehabilitation can benefit from inpatient rehabilitation similarly to their non‐COVID‐19 counterparts with similar rehabilitation‐specific diagnoses.
Narcolepsy in Children: Sleep disorders in children, A rapidly evolving field seeking consensus
Authors: Dye Thomas J. , Simakajornboon Narong
Published: May 2021

Narcolepsy is a life‐long sleep disorder with two distinct subtypes, narcolepsy type I and narcolepsy type II. It is now well recognized that the loss of hypocretin neurons underlies the pathogenesis of narcolepsy type I, however, the pathogenesis of narcolepsy type II is currently unknown. Both genetic and environmental factors play an important role in the pathogenesis of narcolepsy. There is increasing evidence that autoimmune processes may play a critical role in the loss of hypocretin neurons. Infections especially streptococcus and influenza have been proposed as a potential trigger for the autoimmune‐mediated mechanism. Several recent studies have shown increased cases of pediatric narcolepsy following the 2009 H1N1 pandemic. The increased cases in Europe seem to be related to a specific type of H1N1 influenza vaccination (Pandemrix), while the increased cases in China are related to influenza infection. Children with narcolepsy can have an unusual presentation at disease onset including complex motor movements which may lead to delayed diagnosis. All classic narcolepsy tetrads are present in only a small proportion of children. The diagnosis of narcolepsy is confirmed by either obtaining cerebrospinal fluid hypocretin or overnight sleep study with the multiple sleep latency test (MSLT). There are limitations of using MSLT in young children such that a negative MSLT test cannot exclude narcolepsy. HLA markers have limited utility in narcolepsy, but it may be useful in young children with clinical suspicion of narcolepsy. For management, both pharmacologic and non‐pharmacologic treatments are important in the management of narcolepsy. Pharmacotherapy is primarily aimed to address excessive daytime sleepiness and REM‐related symptoms such as cataplexy. In addition to pharmacotherapy, routine screening of behavioral and psychosocial issues is warranted to identify patients who would benefit from bio‐behavior intervention.
Elucidation of ligand binding and dimerization of NADPH:protochlorophyllide (Pchlide) oxidoreductase from pea (Pisum sativum L.) by structural analysis and simulations
Authors: Sameer Hassan , Victor Guallar , Katalin Solymosi , Henrik Aronsson
Published: May 2021

NADPH:protochlorophyllide (Pchlide) oxidoreductase (POR) is a key enzyme of chlorophyll biosynthesis in angiosperms. It is one of few known photoenzymes, which catalyzes the light‐activated trans‐reduction of the C17‐C18 double bond of Pchlide's porphyrin ring. Due to the light requirement, dark‐grown angiosperms cannot synthesize chlorophyll. No crystal structure of POR is available, so to improve understanding of the protein's three‐dimensional structure, its dimerization, and binding of ligands (both the cofactor NADPH and substrate Pchlide), we computationally investigated the sequence and structural relationships among homologous proteins identified through database searches. The results indicate that α4 and α7 helices of monomers form the interface of POR dimers. On the basis of conserved residues, we predicted 11 functionally important amino acids that play important roles in POR binding to NADPH. Structural comparison of available crystal structures revealed that they participate in formation of binding pockets that accommodate the Pchlide ligand, and that five atoms of the closed tetrapyrrole are involved in non‐bonding interactions. However, we detected no clear pattern in the physico‐chemical characteristics of the amino acids they interact with. Thus, we hypothesize that interactions of these atoms in the Pchlide porphyrin ring are important to hold the ligand within the POR binding site. Analysis of Pchlide binding in POR by molecular docking and PELE simulations revealed that the orientation of the nicotinamide group is important for Pchlide binding. These findings highlight the complexity of interactions of porphyrin‐containing ligands with proteins, and we suggest that fit‐inducing processes play important roles in POR‐Pchlide interactions.
Study of Electronic States in LaNiO3/SrRuO3Bilayers: Interface‐Induced Magnetism and Charge Transfer
Authors: Tanguturi Ranganadha Gopalarao , Zhou Peng , Yan Zhuo , Qi Yajun , Xia Zhengcai , Liu Yong , Xiong Rui , Guo Yizhong , Wang Lihua , Srinivasan Gopalan , Zhang Tianjin
Published: May 2021

The results of a study on the electronic states and valence band offset (VBO) in heterostructures of the transition metal oxide LaNiO3(LNO)/SrRuO3(SRO) grown on (001) SrTiO3(STO) substrates are reported. X‐ray photoelectron spectroscopy (XPS) data reveal the presence of Ni2+states in LNO layer that can develop a reduced bandwidth of O‐2pand Ni‐3d. Further analysis of XPS data confirms the presence of a VBO, and the value of VBO is found to be +0.02 eV and –0.38 eV for the bilayers of STO/LaNiO3/SrRuO3(BL‐1) and STO/SrRuO3/LaNiO3(BL‐2), respectively. Distinct signs of VBO are noticed between the bilayers due to the relative shift of the valence band of the top layer with respect to the bottom layer. Such band shifts can lead to the charge transfer across the (3d−4d) interface, which significantly modifies the global electronic transport and magnetic properties of the bilayers. A detailed discussion on the underlying physical phenomena of electrical transport and magnetic responses triggered by the interface is also incorporated herein.
Propagating Surface Plasmon Polaritons Excited at the Graphene Oxide/AgAu Alloy Interface Enhance Nonlinearity
Authors: Simone Giuseppina
Published: May 2021

Graphene oxide (GO) contains intrinsic tunable plasmons, leading to highly attractive plasmonic phenomena, besides the GO coupling with metal nanostructures is promising for plasmonics. Herein, a system consisting of an AgAu alloy entangled in a protein network, AgAu@cages, coupled with a GO layer is designed and analyzed. To overcome the challenges posed by the synthesis of the hybrid GO/metal system, the AgAu alloy is grown inside a proteinaceous network. The approach allows control over the alloy size distribution and a close contact with the samples, with positive impact on the plasmonic analysis. The hybrid system reveals a strong dependence on the incident angle and a shorter linewidth as well as a redshift, motivating further investigations to elucidate the phenomenon. Combined experimental and numerical investigations lead to the displaying of the strong coupling that occurs between the plasmons and the molecular cavity of GO, and a coherent amplification of molecular motion. In conclusion, the versatility of GO‐based systems allows the manufacture of plasmonic and optical devices sensitive to a wide range of frequencies, from terahertz to the visible frequencies, with extremely low driving voltage.
The Nature of Chemical Bonds in the Tetragonal Polymorph of InTe: First‐Principles‐Based Topological Analysis
Authors: Kovalenko Aleksey V. , Bandura Andrei V. , Kuruch Dmitry D. , Lukyanov Sergey I. , Evarestov Robert A.
Published: May 2021

The topological analysis of the electron density is first performed for a bulk InTe crystal using the density functional theory calculations. Several types of two‐center chemical interactions have been identified. Crystal orbital Hamilton population method is used to estimate the corresponding bond strength. As expected, the InTe chemical bonds in the –InTe2– ring chains turn out to be the strongest and have a noticeable covalent contribution. The InIn metallic bonds in linear –In– chains are much weaker. The results obtained reveal that the additional InTe bonds between the –In– and –InTe2– chains can be attributed to weak dative interactions. However, due to their multiplicity, these bonds can play an important role in the stability of the tetragonal InTe phase. The van der Waals interactions of neighboring –InTe2– chains also stabilize the crystal structure. Both Hirshfeld and Bader populations show that the effective charge of indium in the –InTe2– ring chain is noticeably greater than that in the –In– linear chain.
Atomic‐Ordering‐Induced Modulated Properties of Zigzag ZnTe Nanotubes
Authors: Das Monoj , Chowdhury Somnath , Gupta Bikash C.
Published: May 2021

In this work, zigzag ZnTe nanotubes of various diameters are constructed from a ZnTe sheet and are optimized geometrically through density functional theory based energy minimization calculations. The energetically optimized nanotubes are then used to examine their electronic properties. It is found that the band gap of a nanotube may be adjusted over a wide range from 0.5 to 2.3 eV and the work function of a nanotube may be adjusted in the range from 4.7 to 5.8 eV by choosing a nanotube of appropriate diameter. Thus, zigzag ZnTe nanotube may serve as an important band gap material for technological purposes.
Tunable Polymer/Air‐Bragg Optical Microcavity Configurations for Controllable Light–Matter Interaction Scenarios
Authors: Palekar Chirag Chandrakant , Rahimi-Iman Arash
Published: May 2021

Complex optical systems such as high‐quality microcavities enabled by advanced lithography and processing techniques have paved the way to various light–matter interaction (LMI) studies. Sub‐micrometer‐precise lithographic development of a polymer photoresist allows construction of microcavity structures for various spectral regions based on the material's transparency and the geometrical sizes. On the other hand, this approach also avoids lattice‐matching constraints in epitaxy, complex coating techniques, and shaky open‐cavity constructions. Herein, a new approach based on 3D nanowriting in a photoresist is introduced, which can be used to achieve microscopic photonic Fabry–Pérot cavity structures with mechanically tunable resonator modes and polymer/air‐Bragg mirrors, directly on a chip or device substrate. By transfer‐matrix calculations and computer‐assisted modeling, it is demonstrated that open microcavities with up to two “air‐Bragg” reflectors comprising alternating polymer/air‐mirror‐pair layers enable compression‐induced mode tuning that can benefit many LMI experiments, such as with 2D materials, nanoparticles, and molecules.
Simple methods to test the accuracy of MRgFUS robotic systems
Authors: Antoniou Anastasia , Drakos Theocharis , Giannakou Marinos , Evripidou Nikolas , Georgiou Leonidas , Christodoulou Theodora , Panayiotou Natalie , Ioannides Cleanthis , Zamboglou Nikolaos , Damianou Christakis
Published: May 2021

Background

Robotic‐assisted diagnostic and therapeutic modalities require a highly accurate performance to be certified for clinical application. In this paper, three simple methods for assessing the accuracy of motion of magnetic resonance‐guided focused ultrasound (MRgFUS) robotic systems are presented.

Methods

The accuracy of motion of a 4 degrees of freedom robotic system intended for preclinical use of MRgFUS was evaluated by calliper‐based and magnetic resonance imaging (MRI) methods, as well as visually by performing multiple ablations on a plastic film.

Results

The benchtop results confirmed a highly accurate motion in all axes of operation. The spatial positioning errors estimated by MRI evaluation were defined by the size of the imaging pixels. Lesions arrangement in discrete and overlapping patterns confirmed satisfactory alignment of motion trajectories.

Conclusions

We believe the methods presented here should serve as a standard for evaluating the accuracy of motion of MRgFUS robotic systems.
Robust static output feedback based iterative learning control design with a finite‐frequency‐range two‐dimensional specification for batch processes subject to nonrepetitive disturbances
Authors: Hao Shoulin , Liu Tao , Paszke Wojciech , Gałkowski Krzysztof , Wang Qing‐Guo
Published: May 2021

For industrial batch processes subject to time‐varying uncertainties and nonrepetitive disturbances, this article proposes a robust static output feedback (SOF) based iterative learning control (ILC) design with a finite‐frequency‐range two‐dimensional (2D) performance specification. An important advantage of the proposed design lies in its simple structure and easy implementation, with no need to store the state information of the learning controller as used in the existing 2D dynamic output feedback based ILC methods. Based on a 2D Roesser system setting, sufficient conditions are established in terms of nonlinear matrix inequalities to guarantee robust stability of the resulting closed‐loop ILC systems along both the time and batch directions, by using the matrix dilatation technique. Moreover, a finite‐frequency‐range 2D performance specification for attenuating nonrepetitive disturbances is introduced for control synthesis. To derive the feasible SOF based ILC controller gains, a two‐stage heuristic approach is developed for iterative computation based on predesigning the corresponding state feedback based ILC gains. An illustrative example is used to demonstrate the effectiveness and merits of the proposed method.
Does financial inclusion limit carbon dioxide emissions? Analyzing the role of globalization and renewable electricity output
Authors: Qin Lingui , Raheem Syed , Murshed Muntasir , Miao Xu , Khan Zeeshan , Kirikkaleli Dervis
Published: May 2021

On the role of financial inclusion in terms of promoting a sustainable environment, very limited number of studies are available in the existing literature. These studies do not directly address or link financial inclusion with carbon dioxide emissions. Therefore, this study aims to specifically investigate the effects of financial inclusion on carbon dioxide emissions along with the role of globalization and renewable electricity generation for the case of the emerging seven economies over the 2004–2016 period. This study uses panel quantile regression analysis for estimations, which takes into account the non‐normality issue of the data. The long‐run relationships among carbon dioxide emissions, financial inclusion, renewable electricity generation, globalization, and economic growth are confirmed by Kao and Johansen panel cointegration tests. Besides, the results from quantile regression analysis confirmed that financial inclusion is linked with carbon dioxide emission reductions at the 25th and 50th quantiles; however, it cannot explain the variations in the carbon dioxide emission levels at the 75th and 95th quantiles. Moreover, globalization and renewable energy electricity are found to curb carbon dioxide emissions at all quantiles. Further, the results confirmed the EKC hypothesis for E7 countries at all the quantiles. In line with these findings, this study recommends enhancing financial inclusivity, promoting globalization, elevating renewable electricity generation capacities, and ensuring greener economic growth to lower down the carbon dioxide emission levels across the E7 countries.
Preparation of a New Copper/Mercury‐Based Amalgam Electrode with Minimal Mercury Content and Its Application for the Determination of Azathioprine in Biological Fluids
Authors: Alizadeh Taher , Shojaeianfar Moslem , Reza Ganjali Mohammad
Published: May 2021

Herein, a new copper/mercury‐based amalgam electrode with 45 wt % copper was introduced. An amalgam electrode with the lowest mercury content among all amalgam electrodes, reported so far,was introduced. The method of making and activating the electrode was investigated and the working conditions were established. The as‐prepared electrode was employed to determine azathioprine(Aza) using differential pulse adsorptive stripping voltammetry (DPASV) method. The required factors were considered for the electrode voltammetric response to evaluate and optimize Aza level. The proper response of this electrode was obtained in Brinton‐Robinson buffer(BRB) (pH 2) at −0.15 V for 200 seconds. The electrode response to the target compound was linear in the concentration range from 0.04 to 1.0 μM. The detection limit was found to be about 1.6×10−8 M. The relative standard deviation (RSD) for 5 determinations was obtained to be about 3.5 % (the average of RSDs calculated for all concentrations, represented in the calibration curve). The method was successfully applied for Aza determination in plasma and urine samples which led to satisfactory results. It can be concluded that the presence of high levels of potential interfering agents such as ascorbic acid and cysteine did not affect the Aza determination.
Research on Ethanol Sensing Characteristics of Pd/Neck‐Connected‐ZnO Based Chemiresistive Sensors
Authors: Qi Tianjiao , Sun Jie , Yang Xi
Published: May 2021

Different amounts of Pd‐doped neck‐connected‐ZnO (NC‐ZnO) gas sensing materials were successfully synthesized by one‐step hydrothermal method. As a gas sensing material, the sensing performance of Pd‐doped NC‐ZnO has been systematically studied. The results show that palladium doping can improve the performance of NC‐ZnO sensors. NC‐ZnO doped with 5 wt % Pd showed the highest response to ethanol at 250 °C with a response of 311 to 50 ppm ethanol. After palladium doping, due to the catalytic effect of Pd, the ratio of oxygen vacancies on the surface of the material to chemisorption oxygen increases, and the reaction between ethanol molecules and oxygen ions is promoted, thereby greatly improving the gas sensitivity of undoped NC‐ZnO. Therefore, palladium‐doped NC‐ZnO should be a promising method for designing and manufacturing high performance gas sensors.
Magnetic‐Nanoparticle‐Based Dispersive Micro‐Solid Phase Extraction for the Determination of Crystal Violet in Environmental Water Samples
Authors: Shojaei Siroos , Rahmani Mashaallah , Khajeh Mostafa , Abbasian Ahmad Reza
Published: May 2021

In present study, a rapid and simple method based on ultrasonic‐assisted magnetic dispersive micro‐solid phase extraction (MD‐μ‐SPE) using magnetic ZnFe2O4‐ZnS nanocomposites has been proposed for the determination of crystal violet (CV) in environmental water samples. To increase the extraction efficiency, the affecting factors on the ultrasonic‐assisted magnetic dispersive micro‐solid phase extraction method were investigated and optimized by Taguchi method, artificial neural network (ANN), and response surface methodology (RSM). For proposed method, the crystal violet was selected as target dye. Under optimal conditions, the limits of detection were obtained 25 ng mL−1 and the calibration curve showed linearity in the range of 100–600 ng mL−1. The good extraction efficiency obtained indicates that the proposed MD‐μ‐SPE possesses a good potential for the determination of CV in environmental water samples.
Study on the Performance of Copper‐Manganese Composite Oxide Catalysts for Toluene
Authors: Yang Xiaobo , Zhang Zhihong
Published: May 2021

Copper‐manganese (CuMn) composite oxide catalysts were prepared for the catalytic combustion of a common volatile organic compound, namely toluene. The structural properties of the catalysts were analysed by X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET) theory, X‐ray photoelectron spectroscopy (XPS) and hydrogen temperature‐programmed reduction (H2‐TPR). The catalytic stability was examined after 100 h. It was found that Cu1Mn1 exhibited the highest catalytic ability when the molar ratio of Cu : Mn was 1 : 1. The removal of toluene reached 90 % at a temperature below 229 °C. It was speculated that the Cu1.5Mn1.5O4 spinel structure and CuO were formed in the catalyst. The catalyst surface area was not the main factor affecting the catalytic activity. The catalysts displayed good stability and maintained high catalytic activity for a long time. Notably, fresh catalysts contained high amounts of high‐valent Mn4+ and Cu2+ cations, which played important roles in the catalytic combustion of toluene. The cations initiated the redox process and led to the conversion of toluene to CO2 and H2O. The reduced lattice oxygen supplied from air was transformed into surface oxygen on the catalyst. The catalytic combustion of toluene in the presence of CuMn composite oxide catalysts followed the Mars‐van Krevelen mechanism.
Hybridization of Imidazole with Various Heterocycles in Targeting Cancer: A Decade's Work
Authors: Teli Ghanshyam , Chawla Pooja A.
Published: May 2021

Cancer is the world‘s biggest global health concern. The prevalence and mortality rates of cancer remain high despite significant progress in cancer therapy. The search for more effective, as well as less toxic treatment methods for cancer, is at the focus of current studies. Approximately 24.6 million people are suffering from cancer across the world as per the world health organization (WHO). In the year 2020, approximately 10 million deaths were reported due to cancer which has emerged as the second leading cause of mortality across the globe. Anticancer medicines have played a pivotal role in the medication of different types of cancers; however, they are associated with several side effects and relevance of drug resistance which evoke an immediate need for designing of new anticancer agents with multitargeted effect. Imidazole is a heterocyclic compound privileged with considerable anticancer activities and some imidazole derivatives have already got approval to treat cancer. Many hybrid molecules are available that play an important role in the treatment of cancer like chalcone, pyrazole, purine, triazine etc., and their pharmacophore provide the anticancer drug with low drug resistance and high efficacy, with low chances of toxicity and side effects. This review provides various approaches for the drug development of new safe and efficient antitumor agents imidazole hybrids with other heterocyclic moieties. An attempt has been made to advancement of the anticancer potential of the derivatives and hybrids of imidazole having intact or condensed imidazole moiety in the last decade along with the structure‐activity relationship studies, and mechanism of action.
Facile Preparation of CeO2 Supported on Graphene Oxide Sheets for NH3‐SCR: Improvement of Catalytic Activity and SO2 Tolerance
Authors: Zhou Zhiyuan , Wang Yongzhao , Yuan Qunfu , Guo Yanle , Guo Wenyao , Xin Zhiling , Zhang Bingsen , Guo Ruitang
Published: May 2021

In this paper, a series of highly dispersed CeO2 catalysts on graphene oxide sheets (GO) were prepared by simple impregnation method. The catalysts were applied for selective catalytic reduction(SCR) of NO with NH3. Compared with the 5 wt %CeO2/GO and 15 wt %CeO2/GO catalysts, 10 wt %CeO2/GO catalyst exhibited better catalytic performance in the temperature range of 175–325 °C and higher SO2 resistance at 275 °C. The as‐prepared catalysts were characterized by TEM, AFM, XPS, XRD, BET, H2‐TPR, NH3‐TPD and FT‐IR, respectively. The characterization results indicated that 10 wt %CeO2/GO catalyst possessed larger specific surface area, enriched surface acidic sites, high redox capacity and oxygen vacancies. In addition, Ce3+ on the surface of CeO2/GO catalyst could reduce the oxidation property of SO2, thus improving the SO2 resistance of the catalyst. Meanwhile, the stability of 10 wt %CeO2/GO catalyst was tested. At 275 °C, the NO conversion maintained at 94 % within 30 hours, suggesting the excellent stability.
Combat and blast exposure blunt sympathetic response to acute exercise stress in specialised military men
Authors: Taylor Marcus K. , Barczak‐Scarboro Nikki E. , Laver D. Christine , Hernández Lisa M.
Published: May 2021

Electrodermal activity (EDA)—a measure of electrical skin conductance reflecting (exclusive) sympathetic control of the eccrine sweat gland—holds promise as an indicator of central sympathetic activation. The aim of this study was to determine whether combat and blast exposure modulate the EDA response to acute exercise stress in specialised military men. Fifty‐one men (age M = 36.1, SD = 6.5) participated in this study as part of the Explosive Ordnance Disposal Operational Health Surveillance System. The EDA complex (i.e., tonic + phasic conductance) was continuously measured throughout a maximal effort, graded exercise test. As expected, exercise stress resulted in measurable, stepwise increases in EDA before tapering at higher exercise intensities. Individuals with more substantial combat exposure and those with blast exposure demonstrated blunted EDA patterns in comparison to their low/nonexposed counterparts. This blunted pattern might imply sub‐optimal sympathetic nervous system function in the exposed cohorts and enhances our knowledge of factors influencing resilience in these men.
The effects of work and nonwork boundary fit on role satisfaction and subjective well‐being
Authors: Michel Jesse S. , Rotch Michael A. , O’Neill Sadie K.
Published: May 2021

Employees manage work and nonwork boundaries, or socially constructed lines of demarcation, in different ways due to their preferences and ability to do so. When an individual’s integration‐segmentation boundary enactment matches their boundary preference, they possess greater boundary fit. We examined the impact of work and nonwork boundary fit on subjective well‐being, mediated by work and nonwork satisfaction. Results from a three‐wave study confirmed positive direct effects for work/nonwork boundary fit on role satisfaction and role satisfaction on subjective well‐being. We also found significant mediation effects for role satisfaction between work/nonwork boundary fit and subjective well‐being. Overall, work boundary fit had stronger direct and indirect effects than nonwork boundary fit. This research helps clarify theoretical distinctions among work‐nonwork fit constructs and extends the boundary fit literature through an atomistic fit perspective. Future research could consider examining boundary fit through cross‐lagged panel designs and response surface modelling, as well as extending our model to examine nuanced aspects of boundary fit (e.g., physical, temporal, cognitive) and its relationship with additional outcomes (e.g., performance, burnout) and contextual factors (e.g., part‐time vs. full‐time employment, frontline vs. office‐based employment).
Be careful what you wish for: CEO and analyst firm performance attributions and CEO dismissal
Authors: Park Sun Hyun , Chung Sung Hun (Brian) , Rajagopalan Nandini
Published: May 2021

Research Summary

Chief executive officers (CEOs) often make internal attributions of positive firm performance outcomes by highlighting their strategic choices as the cause of favorable performance results. We investigate the dynamic consequences of CEO internal performance attributions along a CEO's tenure. CEO internal attributions create an expectation that favorable firm performance will continue under the CEO's leadership. When firm performance turns negative, however, financial analysts also make internal attributions, pointing to the strategies highlighted by the CEO as the cause of performance downfall. Analysts' internal attributions provide a board with a legitimate account casting doubt on the CEO's leadership efficacy, increasing the likelihood of dismissal. We find strong empirical support for our hypotheses in a panel dataset that tracks CEO and analyst interviews in news media around quarterly earnings announcements.

Managerial Summary

While prior studies of chief executive officers (CEOs) dismissal have considered different factors leading to CEO dismissal, our study highlights the role played by the CEO's own public performance attributions. Our results show that when CEOs attribute positive performance outcome to their leadership, financial analysts are also more likely to attribute subsequent negative performance outcomes to their leadership, which in turn ultimately leads to CEO dismissal. Given the difficulty of predicting firm performance over an extended period of time, CEOs should be aware that when they take credit for positive performance outcomes they may be setting themselves up for subsequent blame from external constituents seeking explanations for negative performance outcomes. Thus, our results suggest that CEOs may stand to gain from more self‐effacing behaviors.
Recommendations in paediatric echocardiography: A green light?
Authors: Gordon Justin
Published: May 2021

The performance of paediatric and congenital heart disease echocardiography requires extensive knowledge of all cardiac anomalies and their physiologic interactions along with an understanding of the surgical or interventional procedures used in the treatment of these lesions. This knowledge is gained through a supervised training program and ongoing performance of paediatric echocardiography supported by an appropriate quality assurance program. Studies have shown a high incidence of errors in paediatric echocardiography when performed by those with limited exposure to this speciality, highlighting the need for appropriate referral of patients with suspected congenital heart disease. With the recent publication of Recommendations for the Adult Cardiac Sonographer Performing Echocardiography to Screen for Critical Congenital Heart Disease in the Newborn from the American Society of Echocardiography, this commentary aims to address the perception that these recommendations may provide the key points necessary for adult trained echocardiographers to perform diagnostic echocardiography in patients with suspected critical congenital heart disease.
Experimental Study of Blast Furnace Hearth Drainage Based on Image Analysis
Authors: Liu Weiqiang , Shao Lei , Saxén Henrik
Published: May 2021

A smooth hearth drainage is one of the key requirements for maintaining an efficient blast furnace operation. For achieving this, it is necessary to understand the hearth drainage behavior and the effect of related process parameters. To investigate the drainage, a set of experiments is conducted in a 2D Hele−Shaw model, where the influence of the initial accumulated amount of molten liquids (iron and slag), blast pressure, and slag viscosity on the drainage behavior is studied using water and oil as liquids. To quantify the findings, an image analysis‐based algorithm is applied to extract drainage information that is used to analyze the effect of the mentioned process factors on the evolution of the liquid levels and volumes, flow rates, share oil in the outflow, and angle of the interfaces at the outlet. Herein, the implications of the results for the operation of the blast furnace hearth are discussed.
Influences of Quenching Temperature on the Microstructure Evolution and Strength−Toughness of a Novel Medium‐Carbon Ti−Mo‐Bearing Martensite Steel
Authors: Guan Jisheng , Yuan Qing , Yuan Qinpan , Fan Lei , Yang Yuebiao , Xu Guang
Published: May 2021

The simultaneous improvement of strength and toughness in high‐strength steels is a challenging task. Herein, a novel medium‐carbon Ti−Mo‐bearing martensite steel is developed. The influences of quenching temperature on microstructure evolution and strength−toughness are investigated. Microstructure and precipitation analyses are conducted to clarify possible reasons for the improvement of strength−toughness in the as‐developed steel. After the addition of Ti and Mo, the martensite steel yields a high tensile strength of ≈1700 MPa and an impact energy of 43 J at –40 °C. The improved strength and toughness is attributed to better grain refinement strengthening and precipitation strengthening by combination of thermo−mechanical control process (TMCP) and quenching and tempering (Q−T) processes. Although no significant variation is observed in the strengths of Ti−Mo‐bearing martensite steels quenched at a temperature range of 850−910 °C, the impact energy of Ti−Mo‐bearing martensite steel obviously decreases at a higher quenching temperature of 910 °C. The decreased low‐temperature impact energy is caused by the coarsening of (Ti, Mo)C precipitates.
Extraction, Purification, Characterization, and Bioactive Properties of Polysaccharides from Sphallerocarpus gracilis
Authors: Li Yan , Assani Israa , Wang Jia‐Wei , Wang Chun‐Gu , Sun Bo , Liu Ling‐Fei , Wang Mu‐Xuan , Chen Zhi , Liao Zhi‐Xin
Published: May 2021

Four new polysaccharides, SGP‐1‐4, are isolated and purified from Sphallerocarpus gracilis (S. gracilis) . The monosaccharide analysis revealed that the isolated polysaccharides are composed of different molar ratios of glucose (Glu), galactose (Gal), rhamnose (Rha), mannose (Man), and arabinose (Ara). Congo red test showed that no triple helical structure is detected in SGP‐1‐4. The Zeta potentials of SGP‐1‐4 are negative. The antioxidant activities are evaluated using DPPH and Superoxide radical assays. In vitro antitumor activities are investigated by MTT assay and Calcein‐AM/PI staining confocal imaging. The hypolipidemic activities are measured by the bile‐salt binding capacity in vitro. The results indicated that SGP‐1‐4 possessed significant antioxidant and hypolipidemic abilities. At the concentration of 0.2 mg/mL, the purified polysaccharides possess no significant effects against MGC‐803 (Human gastric cancer cells), A2780 (Human ovarian cancer cells), T24 (Human bladder cancer cells), CNE‐2 (Human nasopharyngeal cancer cells), and 4T1 (Mouse breast cancer cells) tumor cells in vitro. However, the SGP‐2 shows potential as a DOX‐chemotherapy against 4T1 cells, which indicated that SGP‐2 could exert antitumor effects. These findings provide a scientific basis for the further use of S. gracilis polysaccharides as a natural antioxidant, antitumor, and hypolipidemic agent in industry.
“There are other ways to help besides using the stuff”: Using activity theory to understand dynamic student participation in small group science, technology, engineering, and mathematics activities
Authors: Wieselmann Jeanna R. , Dare Emily A. , Roehrig Gillian H. , Ring‐Whalen Elizabeth A.
Published: May 2021

Integrated approaches to teaching science, technology, engineering, and mathematics (STEM) are increasingly being implemented in elementary and middle school classrooms, and despite a variety of conceptions of integrated STEM, researchers agree that small group activities and teamwork play a central role in STEM learning. However, little is known about how students participate in the small group portions of integrated STEM curricular units. In this study, a microvideo ethnography framed within activity theory was used to examine small group interactions among sixth‐grade students completing integrated STEM activities related to the properties of light. Students working in three different small groups (all‐girl, all‐boy, and mixed‐gender) were included in the analysis. Findings highlight differences in the activity systems across activity type (science vs. engineering) and across small groups, with students focusing on different objectives for completing STEM activities, utilizing different tools as they sought to reach their objectives, and dividing labor differently. Findings from this study suggest that these students, and girls in particular, were less prepared to navigate open‐ended engineering activities than highly structured science activities. Theoretical and practical implications for curriculum development and pedagogical strategies are discussed.
Humeral intracondylar fissures in French bulldogs
Authors: Strohmeier Ulrike W. , Harris Karen P.
Published: May 2021

Background

French bulldogs have previously been reported to be at an increased risk of developing humeral condylar fractures (HCF). Humeral intracondylar fissures (HIF) are thought to be a predisposing factor for HCF occurrence in skeletally mature dogs particularly when the fracture occurs during normal activity. We hypothesised that HIF may be a predisposing factor for HCF in French bulldogs.

Methods

A retrospective case series of nine French bulldogs that had sustained HCF and where CT was performed prior to surgery.

Results

Five of the fractured humeri had sclerosis adjacent to the fracture site. Six of the contralateral intact humeri were diagnosed with HIF on the basis of a partial (2/6) or complete (4/6) hypoattenuating area extending between the distal articular surface and the supratrochlear foramen in the sagittal plane, with adjacent sclerosis (6/6).

Conclusions

Recognition of sclerosis at the intracondylar fracture surface on CT can prompt suspicion that HIF preceded HCF. A predisposing HIF has potentially great clinical significance for this breed if we draw parallels with breeds such as the springer spaniel for whom HIF and HIF‐associated condylar fracture is well documented.