bluuebunny/crossref_metadata_2025 huggingface dataset:
A Safety Study of the Effects of 2‐Dimensional Shear Wave Elastography on Synaptic Morphologic Characteristics and Function in the Hippocampus of Neonatal Mice
Authors: Zhang Cheng , Li Nan , Li Changtian , Li Junlai
Published: July 2020

Objectives

The aim of this study was to determine the effects of 2‐dimensional (2D) shear wave elastography (SWE) on synaptic morphologic characteristics and function in the neonatal mouse hippocampus and whether it affects the capacity for learning and memory later in life.

Methods

We divided neonatal mice into a control group and a 2D SWE group scanned for 10, 20, or 30 minutes. Hippocampal morphologic characteristics were assessed by hematoxylin–eosin and Nissl staining. Ultrastructures of hippocampal neurons were visualized by electron microscopy. Protein and messenger RNA expression levels of synaptophysin, N‐methyl‐d‐aspartate receptor 1 (NMDAR1), NMDAR2A, and NMDAR2B were quantified by a western blot and polymerase chain reaction, respectively. Learning and memory of adult mice were evaluated by the Morris water maze and the novel object recognition task.

Results

Compared with the control group, the hippocampal morphologic characteristics of the experimental groups did not differ under light microscopy, and the synaptic structures assessed by electron microscopy appeared normal. Western blot and polymerase chain reaction results showed that expression of synaptophysin, NMDAR1, NMDAR2A, and NMDAR2B were downregulated after exposure to 2D SWE, but there were no statistical differences between the experimental groups. This downregulation disappeared within 24 hours. The results of the Morris water maze and novel object recognition suggested that the 2D SWE scanning on neonatal mice had no effect on learning and memory in adulthood.

Conclusions

This study demonstrated that when the mice were exposed to neonatal cranial ultrasound by 2D SWE lasting for longer than 10 minutes, the expression of genes involved in synaptic function was affected, but this effect lasted no longer than 24 hours and did not affect learning and memory in adulthood.
Factors Associated With Distribution of Female Otolaryngology Residents in United States
Authors: Sulibhavi Anita , Kaufmann Matthew R. , Shetty Kunal R. , Wulu Jacqueline A. , Tracy Lauren F. , Levi Jessica R.
Published: July 2020

Objective

The gender balance within medicine, and specifically within otolaryngology, is equalizing. It is important to determine the factors that impact the distribution of female residents among otolaryngology programs in the United States to better understand factors that may affect these changing trends.

Study Design

Retrospective Study.

Methods

Cross‐sectional analysis was performed using data from 2018 of otolaryngology residents at 90 programs across the United States. Each program's website was searched for a current resident roster. Data of geography, number of female faculty, number of female physicians in leadership positions, program setting, and program size were obtained. Statistical comparison of these factors with number of female residents was performed with P < .05 as significant.

Results

There was a significant association between programs having a higher‐than‐average female faculty representation and a greater representation of female residents (P < .001). Larger residency programs were more likely to have greater female representation (P = .010). There was a slight predominance of both female residents and female faculty at urban programs (odds ratio [OR] = 1.27, P = .04; OR = 1.28, P = .03). Geographic location, presence of a female chairperson, and presence of a female residency program director were not associated with higher female‐to‐male resident ratio.

Conclusion

Availability of female role models in faculty, along with program setting and size, may be more likely to promote greater female representation. Focusing on gender equality in the workplace can help promote diversity in the workforce and improve patient outcomes.

Level of Evidence

NA Laryngoscope, 131:E367–E372, 2021
Effect of Ti3SiC2 content on the corrosion behavior of Al/Ti3SiC2 composite coatings
Authors: Jamshidi Rasoul , Bayat Omid , Heidarpour Akbar
Published: July 2020

The purpose of this study was to investigate the electrochemical corrosion properties of flame‐sprayed Al and Al/(5, 10, 15)% Ti3SiC2 coatings in a 3.5% NaCl solution. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) were used for analyzing the microstructural characteristics of the coatings. For examining the corrosion behavior of the coatings, a potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS) were used. After the potentiodynamic polarization test, the SEM micrograph of coatings indicated that Ti3SiC2 particles played a significant role in pitting corrosion. The results of potentiodynamic polarization tests revealed that Al/Ti3SiC2 coating is nobler than that of the pure aluminum coating. On the contrary, the addition of Ti3SiC2 particles reduced the process of thickening the passive layer. The results of the EIS tests demonstrated that the presence of Ti3SiC2 particles significantly enhances the corrosion resistance of the coatings.
Effect of Macromolecular Crowders on the Self‐Assembly Process of Silk Fibroin
Authors: Dubey Priyanka , Seit Sinchan , Chowdhury Pramit K. , Ghosh Sourabh
Published: July 2020

Macromolecular crowding is known to have a significant impact on the aggregation and folding of proteins. In this study, the role of different macromolecular crowders such as polyethylene glycol (PEG 200 and PEG 6000) and dextran (dextran 6000 and 70000) on the self‐assembly of silk fibroin protein is explored. The data show that crowders induce a clear transition from random coil to β‐sheet secondary conformation in the fibroin as demonstrated by ThT fluorescence spectroscopy, circular dichroism, and ATR‐FTIR findings. However, this transition is not observed in case of control sample (fibroin without crowders). Excluded volume effects accelerate the kinetics of self‐association of the fibroin protein. Increasing the molecular weight of crowders increases the required time for maximum aggregation. This study suggests that treating the fibroin with different macromolecular crowders has modulated the propensity of fibroin going into β‐sheet conformation.
Flexible and Conductive 3D Printable Polyvinylidene Fluoride and Poly(N,N‐dimethylacrylamide) Based Gel Polymer Electrolytes
Authors: Rahman Md Sazzadur , Shiblee MD Nahin Islam , Ahmed Kumkum , Khosla Ajit , Ogawa Jun , Kawakami Masaru , Furukawa Hidemitsu
Published: July 2020

In this work, 3D printable gel polymer electrolytes (GPEs) based on N,N‐dimethylacrylamide (DMAAm) and polyvinylidene fluoride (PVDF) in lithium chloride containing ethylene glycol solution are synthesized and their physicochemical properties are investigated. 3D printing is carried out with a customized stereolithography type 3D gel printer named “Soft and Wet Intelligent Matter‐Easy Realizer” and free forming GPE samples having variable shapes and sizes are obtained. Printed PVDF/PDMAAm‐based GPEs exhibit tunable mechanical properties and favorable thermal stability. Electrochemical proprieties of the printed GPEs are carried out via impedance spectroscopy in the temperature range of 25–90 °C by varying PVDF content. Ionic conductivity as high as 6.5 × 10−4 S cm−1 is achieved at room temperature for GPE containing low PVDF content (5 wt%) and conductivity of the GPEs is increased as temperature rises.
Multicompartment Polymeric Nanocarriers for Biomedical Applications
Authors: Nayanathara Umeka , Kermaniyan Sarah S. , Such Georgina K.
Published: July 2020

Multicompartment polymeric nanocarriers which mimic the compartmentalized architecture of living cells have received considerable research attention in the biomedical field. The advancement of synthetic polymeric chemistry has allowed multicompartment polymeric nanocarriers to be tailored for biomedical applications such as drug delivery, encapsulated catalysis, and artificial cellular mimics. In this review, polymer‐based multicompartment nanocarriers (multicompartment micelles, multicompartment polymersomes, and capsosomes) have been discussed. This review focuses on multicompartment systems applied to biomedical applications over the last ten years. The synthetic procedures and structural properties that impact the specific application are also highlighted.
Effect of rotor cage's outer and inner radii on the inner flow field of the turbo air classifier
Authors: Yu Y. , Kong X. , Liu J.
Published: July 2020

The effects of rotor cage's outer and inner radii on flow field of the turbo air classifier are comparatively analyzed by numerical simulation using ANSYS‐FLUENT. The results of quantitative analysis show when the rotor cage's outer and inner radii are increased, the tangential velocity, radial velocity and upward axial velocity decrease in the annular region and near the entrance of the rotor cage. However, when the rotor cage's outer and inner radii are too large or too small, the tangential velocity and radial velocity will be fluctuated greatly. Moreover, the rotor cage's outer and inner radii directly influence the radial velocity distribution in the rotor cage channel. The rotor cage's outer and inner radii should not be too large or too small. Therefore, in the seven contrast rotor cage models, model 100–70 and 90–60 are selected to carry out the calcium carbonate classification experiments due to their small tangential velocity and radial velocity fluctuations and well‐distribution in the rotor cage channel. The experimental results reflect the characteristics of the numerically simulated flow field in the classifier.
Effect of tempering temperature on microstructure and properties of aluminium‐bearing high boron high speed steel
Authors: Qu Y. , He X. , Zhang X. , Fu H. , Cheng X. , Liu X.
Published: July 2020

Heat treatment is of great significance to the performance improvement of high speed steel. Via heat treatment, the microstructure of high speed steel can be improved, thus greatly improving the material performance. The effect of tempering temperature on the microstructure of aluminium‐bearing high boron high speed steel (AB‐HSS) was investigated by optical microscope (OM), scanning electron microscope (SEM) and x‐ray diffraction (XRD). The hardness and wear resistance of the alloy at different tempering temperatures were tested by Rockwell hardness tester, micro‐hardness tester and wear tester. The experimental results indicate that the tempering microstructure of aluminium‐bearing high boron high speed steel consists of α‐Fe, M2B and a few of M23(C, B)6. Tempering temperature could greatly affect the wear resistance of materials. With the increase of tempering temperature, the wear resistance of aluminium‐bearing high boron high speed steel firstly increase and then decrease. The alloy tempered at 450 °C has the best wear resistance and minimum wear weight loss. This study provides a reference for the formulation of heat treatment process of aluminium‐bearing high boron high speed steel.
Quantitative Measurement of Metal Accumulation in Brain of Patients With Wilson's Disease
Authors: Li Gaiying , Wu Rong , Tong Rui , Bo Binshi , Zhao Yu , Gillen Kelly M. , Spincemaille Pascal , Ku Yixuan , Du Yasong , Wang Yi , Wang Xiaoping , Li Jianqi
Published: July 2020

Background

Currently, no study has evaluated metal accumulation in the brains of patients with Wilson's disease by using quantitative susceptibility mapping at 3T MRI. The objectives of this study were to qualitatively and quantitatively evaluate changes in magnetic susceptibility and R2* maps in deep gray matter nuclei to discriminate Wilson's disease patients from healthy controls and to evaluate their sensitivities in diagnosing Wilson's disease.

Methods

Magnetic susceptibility and R2* maps and conventional T1‐weighted, T2‐weighted, and T2‐weighted fluid‐attenuated inversion recovery images were obtained from 17 Wilson's disease patients and 14 age‐matched healthy controls on a 3T MRI scanner. Differences between Wilson's disease and healthy control groups in susceptibility and R2* values in multiple deep nuclei were evaluated using a Mann‐Whitney U test and receiver operating characteristic curves. The correlations of susceptibility and R2* values with Unified Wilson's Disease Rating Scale score were also performed.

Results

Magnetic susceptibility and R2* can effectively distinguish different types of signal abnormalities. Magnetic susceptibility and R2* values in multiple deep nuclei of Wilson's disease patients were significantly higher than those in healthy controls. Magnetic susceptibility value in the substantia nigra had the highest area under the curve (0.888). There were positive correlations of the Unified Wilson's Disease Rating Scale score with susceptibility values in the caudate nucleus (r = 0.757, P = 0.011), putamen (r = 0.679, P = 0.031), and red nucleus (r = 0.638, P = 0.047), as well as R2* values in the caudate nucleus (r = 0.754, P = 0.012).

Conclusions

Quantitative susceptibility mapping at 3T could be a useful tool to evaluate metal accumulation in deep gray matter nuclei of Wilson's disease patients. © 2020 International Parkinson and Movement Disorder Society
MicroRNA Deregulation in Blood Serum Identifies Multiple System Atrophy Altered Pathways
Authors: Pérez‐Soriano Alexandra , Bravo Paloma , Soto Marta , Infante Jon , Fernández Manel , Valldeoriola Francesc , Muñoz Esteban , Compta Yaroslau , Tolosa Eduard , Garrido Alicia , Ezquerra Mario , Fernández‐Santiago Rubén , Martí María‐José ,   the Catalan MSA registry (CMSAR)
Published: July 2020

Background and Objectives

MicroRNA (miRNA) changes are observed in PD but remain poorly explored in other α‐synucleinopathies such as MSA.

Methods

By genome‐wide analysis we profiled microRNA expression in serum from 20 MSA cases compared to 40 controls. By qPCR we validated top differentially expressed microRNAs in another sample of 20 MSA and 20 controls. We also assessed the expression of MSA differentially expressed microRNAs in two consecutive sets of 19 and 18 PD patients.

Results

In the discovery set we identified 25 differentially expressed microRNAs associated with MSA, which are related to prion disease, fatty acid metabolism, and Notch signaling. Among these, we selected nine differentially expressed microRNAs and by qPCR confirmed array findings in a second MSA sample. MicroRNA‐7641 and microRNA‐191 consistently differentiated between MSA and PD.

Conclusions

Serum microRNA changes occur in MSA and may reflect disease‐associated mechanisms. We identified two microRNAs which may differentiate MSA from PD. © 2020 International Parkinson and Movement Disorder Society
A new class of wideband microstrip falcate patch antennas with reconfigurable capability at circular‐polarization
Authors: Shirkolaei M. Mohammadi , Jafari M.
Published: July 2020

A new wideband microstrip antenna, based on the falcate‐shaped patch, with reconfigurable capability at circular‐polarization is presented in this article. To achieve both properties of stable radiation characteristics and impedance matching across a broad bandwidth, the combination of the L‐probe feeding and falcate‐shaped patch is used. An RF‐switch is utilized to excite the L‐probes and generate either left‐hand circular polarization or right‐hand circular polarization over the wide operating bandwidth. A prototype of the proposed antenna is fabricated. An excellent agreement exists between the simulation and measurement results. The results reveal a wide impedance matching (|S11| <  − 10 dB), bandwidth of 55% (1.42‐2.5 GHz), and a 3 dB axial ratio bandwidth of 44% (1.6‐2.5 GHz). Furthermore, results confirm good radiation and impedance matching performance of the fabricated antenna over the wide bandwidth in comparison with previous related investigations. The reported reconfigurable antenna can be used as a suitable choice for GPS, ISM band, or RFID applications
The effect of pulmonary vessel suppression on computerized detection of nodules in chest CT scans
Authors: Gu Xiaomeng , Xie Weiyang , Fang Qiming , Zhao Jun , Li Qiang
Published: July 2020

Purpose

In chest computed tomography (CT) scans, pulmonary vessel suppression can make pulmonary nodules more evident, and therefore may increase the detectability of early lung cancer. The purpose of this study was to develop a computer‐aided detection (CAD) system with a vessel suppression function and to verify the effectiveness of the vessel suppression on the performance of the pulmonary nodule CAD system.

Methods

A CAD system with a vessel suppression function capable of suppressing vessels and detecting nodules was developed. First, a convolutional neural network (CNN)‐based pulmonary vessel suppression technique was employed to remove the vessels from lungs while preserving the nodules. Then, a CNN‐based pulmonary nodule detector was utilized to sequentially generate nodule candidates and reduce false positives (FPs). The performance levels of CAD systems with and without the vessel suppression function were compared using 888 three‐dimensional chest CT scans from the Lung Nodule Analysis 2016 (LUNA16) dataset. The pulmonary nodule detection results were quantitatively evaluated using the average sensitivity at seven predefined FP rates: 0.125, 0.25, 0.5, 1, 2, 4, and 8 FPs per scan.

Results

The developed pulmonary nodule CAD system improved the average sensitivity to 0.977 from 0.950 owing to the addition of the vessel suppression function.

Conclusions

The vessel suppression function considerably improved the performance of the CAD system for pulmonary nodule detection. In practice, it would be embedded in CAD systems to assist radiologists in detecting pulmonary nodules in chest CT scans.
Three‐element matching networks for receive‐only MRI coil decoupling
Authors: Wang Wenjun , Zhurbenko Vitaliy , Sánchez‐Heredia Juan Diego , Ardenkjær‐Larsen Jan Henrik
Published: July 2020

Purpose

Preamplifier decoupling is useful for minimizing interaction between MRI array elements. The purpose of this work is to propose a general approach to designing networks for preamplifier decoupling while keeping the number of elements to a minimum. The approach is applicable to arbitrary impedance preamplifiers and arbitrary coil impedances.

Methods

Closed form design equations for decoupling networks are derived based on maximum decoupling and minimum preamplifier noise conditions. The analytical solutions are verified using numerical simulations. Design examples at 32.1, 64, 128, and 298 MHz are shown. One of the examples is realized on a test bench. The fabricated circuit is tested for decoupling and minimum noise properties.

Results

The design equations are verified numerically and experimentally. The fabricated network demonstrates 30.7 dB of decoupling and minimum output noise at the design frequency.

Conclusion

The design equations lead to four alternative network solutions. Each network is realized as a T‐shape or Π‐shape three elements circuit topology. All four networks are identical in performance providing minimum amplifier noise and maximum decoupling for a given preamplifier and coil combination. An MRI array designer can choose any solution out of four. The considerations for choosing the most practical solution are given. The presented method enables the use of arbitrary impedance preamplifiers or transistors (not necessary 50 Ω) and provides the most compact design possible (with the least number of components), which is particularly useful in multi‐element systems.
Effects of physical activity and melatonin on brain‐derived neurotrophic factor and cytokine expression in the cerebellum of high‐fat diet‐fed rats
Authors: Sugiyama Ai , Kato Hisashi , Takakura Hisashi , Osawa Seita , Maeda Yuki , Izawa Tetsuya
Published: July 2020

Aims

Obesity suppresses brain‐derived neurotrophic factor (BDNF) expression and increases the expression of pro‐inflammatory cytokines. Herein, we assessed whether exercise training (ET), melatonin administration (MT), or their combination can affect the expressions of BDNF and cytokines in the cerebellum of high‐fat diet (HFD)‐fed rats.

Methods

Wistar rats (4 weeks old) were divided into five groups: normal diet (ND)‐fed control (ND‐SED), HFD‐fed control (HFD‐SED), HFD‐fed ET (HFD‐ET), HFD‐fed MT (HFD‐MT), and HFD‐fed MT plus ET (HFD‐ETMT) group. The rats were fed ND or HFD for 17 weeks. Rats were subjected to ET (running on a treadmill) and/or MT (melatonin 5 mg/kg body weight, i.p.) for 9 weeks, 8 weeks after beginning the diet intervention. Changes in BDNF and cytokine expression levels were determined using immunoblotting and cytokine arrays, respectively, 36 hours following the last bout of ET.

Results

Neither HFD‐ET nor HFD‐MT rats exhibited enhanced BDNF expression in the cerebellum, but HFD‐ETMT rats had higher level of BDNF expression compared with the others. The expression of TrkB, a BDNF receptor, was higher in HFD‐ETMT rats than in HFD‐ET and HFD‐MT rats. HFD enhanced the expression of interleukin (IL)‐1, IL‐2, and interferon‐γ but reduced the expression of IL‐4, IL‐6, and IL13. ET and ET plus MT counteracted these HFD‐induced changes in cytokine expressions.

Conclusion

Exercise in combination with melatonin confers the potential benefits of increasing BDNF and improving HFD‐induced dysregulations of cytokines in the cerebellum.
Podocytes present antigen to activate specific T cell immune responses in inflammatory renal disease
Authors: Li Shan , Liu Ying , He Yueqin , Rong Weiwei , Zhang Mingchao , Li Limin , Liu Zhihong , Zen Ke
Published: July 2020

Infiltration of activated T cells into renal tissue plays an essential role in inflammatory nephropathy. However, the mechanism enabling the renal recruitment and activation of T cells remains elusive. Here we report that inflammatory cytokine‐promoted antigen presentation by podocytes is a key for recruiting and activating specific T cells. Our results showed that diabetes‐associated inflammatory cytokines IFNγ and IL‐17 all upregulated expression of MHC‐I, MHC‐II, CD80 and CD86 on the podocyte surface. Both IFNγ and IL‐17 stimulated the uptake and processing of ovalbumin (OVA) by mouse podocytes, resulting in presentation of OVA antigen peptide on the cell surface. OVA antigen presentation by podocytes was also validated using human podocytes. Furthermore, OVA antigen‐presenting mouse podocytes were able to activate OT‐I mouse T cell proliferation and inflammatory cytokine secretion, which in turn caused podocyte injury and apoptosis. Finally, OT‐I mice subjected to direct renal injection of OVA plus IFNγ/IL‐17 but not OVA alone exhibited OVA antigen presentation by podocytes and developed nephropathy in 4 weeks. In conclusion, antigen presentation by podocytes under inflammatory conditions plays an important role in activating T cell immune responses and facilitating immune‐mediated glomerular disease development. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Synthesis of diagnostic quality cancer pathology images by generative adversarial networks
Authors: Levine Adrian B , Peng Jason , Farnell David , Nursey Mitchell , Wang Yiping , Naso Julia R , Ren Hezhen , Farahani Hossein , Chen Colin , Chiu Derek , Talhouk Aline , Sheffield Brandon , Riazy Maziar , Ip Philip P , Parra‐Herran Carlos , Mills Anne , Singh Naveena , Tessier‐Cloutier Basile , Salisbury Taylor , Lee Jonathan , Salcudean Tim , Jones Steven JM , Huntsman David G , Gilks C Blake , Yip Stephen , Bashashati Ali
Published: July 2020

Deep learning‐based computer vision methods have recently made remarkable breakthroughs in the analysis and classification of cancer pathology images. However, there has been relatively little investigation of the utility of deep neural networks to synthesize medical images. In this study, we evaluated the efficacy of generative adversarial networks to synthesize high‐resolution pathology images of 10 histological types of cancer, including five cancer types from The Cancer Genome Atlas and the five major histological subtypes of ovarian carcinoma. The quality of these images was assessed using a comprehensive survey of board‐certified pathologists (n = 9) and pathology trainees (n = 6). Our results show that the real and synthetic images are classified by histotype with comparable accuracies and the synthetic images are visually indistinguishable from real images. Furthermore, we trained deep convolutional neural networks to diagnose the different cancer types and determined that the synthetic images perform as well as additional real images when used to supplement a small training set. These findings have important applications in proficiency testing of medical practitioners and quality assurance in clinical laboratories. Furthermore, training of computer‐aided diagnostic systems can benefit from synthetic images where labeled datasets are limited (e.g. rare cancers). We have created a publicly available website where clinicians and researchers can attempt questions from the image survey (http://gan.aimlab.ca/). © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Tools to guide the identification and implementation of care consistent with the psychosocial Standards of care
Authors: Wiener Lori , Kupst Mary Jo , Pelletier Wendy , Kazak Anne E. , Thompson Amanda L.
Published: July 2020

Fifteen evidence‐based Standards of psychosocial care for children with cancer and their families have been established. Despite the importance of implementing the standards, significant barriers and challenges exist. In order to overcome barriers to implementation and assess the level of current psychosocial care, a model of evaluating psychosocial care (Matrix) and a set of pathways toward achieving optimal care (Guidelines) were developed. This special report describes the process involved in the creation of standard templates and development of content based on rigorous reviews from multidisciplinary psychosocial experts, focus groups, and multiple revisions based on further expert review. The resulting Matrix and Guidelines are included as Supplemental Information.
Enhanced mechanical and tribological properties of Kevlar/PTFE‐phenolic composites by improving interfacial properties by aramid nanofibers
Authors: Yang Mingming , Zhang Zhaozhu , Yuan Junya , Wu Liangfei , Li Peilong , Zhao Xin , Men Xuehu
Published: July 2020

To gain an in‐depth understanding of improving interfacial properties of the fabric‐reinforced polymer composites, aramid nanofibers (ANFs) were constructed in situ on Kevlar and PTFE fiber surface to promote the mechanical and tribologic properties of Kevlar/PTFE‐phenolic composites. Through rich interactions between in situ ANFs and the phenolic matrix, the interfacial characteristics of the inert and smooth functional fibers contained in the prepared composite change greatly. The tensile and bonding strength of ANF‐reinforced Kevlar/PTFE‐phenolic composite are increased by 32.1% and 30.32%, respectively. More importantly, the wear rate of ANF‐modified Kevlar/PTFE‐phenolic composites is decreased by 76.1%, compared with pristine composite. This work demonstrates that in situ formation ANFs on continuous Kevlar and PTFE fibers surface may endow robust interfacial adhesion strength and outstanding mechanical properties that are necessary for functional applications.
Stepwise mass spectrometry‐based approach for confirming the presence of benzoxazinoids in herbs and vegetables
Authors: Bhattarai Bina , Steffensen Stine K. , Gregersen Per L. , Kristensen Hanne L. , Fomsgaard Inge S.
Published: July 2020

Introduction

Benzoxazinoids (BXs) are plant phytochemicals that have both defensive properties in plants and therapeutic effects in humans. The presence of BXs has been largely studied in the Poaceae family (monocots). To study the presence or absence of BXs in dicotyledons and monocotyledons outside the Poaceae family, parts of 24 plant species at several growth stages were selected for analysis, some of which were already known to contain BXs.

Objectives

To devise a stepwise mass spectrometry‐based approach for confirming the presence of BXs in plant samples, and to use the method to explore the status of BXs in selected plant species.

Experimental

Plant samples were extracted using accelerated solvent extraction and analysed using triple‐quadrupole liquid chromatography‐mass spectrometry.

Results

The use of different columns, double mass transitions, and ion ratios proved to be a robust tool for confirming the presence of BXs in different plant species. By this method, the presence of BXs was confirmed in three of the 24 species. Double‐hexose forms of BXs, which have not been reported before in dicotyledons, were confirmed to be present in the dicotyledon plants Acanthus mollis and Lamium galeobdolon, and the presence of BXs in the seeds of Consolida orientalis is reported for the first time here. High concentrations of BXs were found in the aerial parts of Acanthus mollis and Lamium galeobdolon, at 20 and 32 μmol/g plant dry weight, respectively.

Conclusions

The stepwise approach described in this work confirmed the presence of BXs in new samples.
Using l‐Carnitine as a Pharmacologic Probe of the Interpatient and Metabolic Variability of Sepsis
Authors: Jennaro Theodore S. , Puskarich Michael A. , McCann Marc R. , Gillies Christopher E. , Pai Manjunath P. , Karnovsky Alla , Evans Charles R. , Jones Alan E. , Stringer Kathleen A.
Published: July 2020

Objective

The objective of this review is to discuss the therapeutic use and differential treatment response to Levo‐carnitine (l‐carnitine) treatment in septic shock, and to demonstrate common lessons learned that are important to the advancement of precision medicine approaches to sepsis. We propose that significant interpatient variability in the metabolic response to l‐carnitine and clinical outcomes can be used to elucidate the mechanistic underpinnings that contribute to sepsis heterogeneity.

Methods

A narrative review was conducted that focused on explaining interpatient variability in l‐carnitine treatment response. Relevant biological and patient‐level characteristics considered include genetic, metabolic, and morphomic phenotypes; potential drug interactions; and pharmacokinetics (PKs).

Main Results

Despite promising results in a phase I study, a recent phase II clinical trial of l‐carnitine treatment in septic shock showed a nonsignificant reduction in mortality. However, l‐carnitine treatment induces significant interpatient variability in l‐carnitine and acylcarnitine concentrations over time. In particular, administration of l‐carnitine induces a broad, dynamic range of serum concentrations and measured peak concentrations are associated with mortality. Applied systems pharmacology may explain variability in drug responsiveness by using patient characteristics to identify pretreatment phenotypes most likely to derive benefit from l‐carnitine. Moreover, provocation of sepsis metabolism with l‐carnitine offers a unique opportunity to identify metabolic response signatures associated with patient outcomes. These approaches can unmask latent metabolic pathways deranged in the sepsis syndrome and offer insight into the pathophysiology, progression, and heterogeneity of the disease.

Conclusions

The compiled evidence suggests there are several potential explanations for the variability in carnitine concentrations and clinical response to l‐carnitine in septic shock. These serve as important confounders that should be considered in interpretation of l‐carnitine clinical studies and broadly holds lessons for future clinical trial design in sepsis. Consideration of these factors is needed if precision medicine in sepsis is to be achieved.
Graft modification of starch nanoparticles with pH‐responsive polymers via nitroxide‐mediated polymerization
Authors: Cazotti Jaime C. , Fritz Alexander T. , Garcia‐Valdez Omar , Smeets Niels M. B. , Dubé Marc A. , Cunningham Michael F.
Published: July 2020

The grafting to approach and nitroxide‐mediated polymerization (NMP) were used to graft modify starch nanoparticles (SNP) with pH‐responsive polymers. SG1‐capped poly(2‐(dimethylamino)ethyl methacrylate‐co‐styrene), P(DMAEMA‐co‐S), and poly(2‐(diethylamino)ethyl methacrylate‐co‐styrene), P(DEAEMA‐co‐S), with relatively low dispersity and high degree of livingness was synthesized in bulk via NMP using a commercial available alkoxyamine. These macroalkoxyamines were then grafted to vinyl benzyl‐functionalized SNP (SNP‐VBC) to obtain pH‐responsive materials. The grafted SNP were characterized by proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and elemental analysis confirming the successful synthesis of these new materials. Low grafting efficiencies (~6%) were observed for both SNP‐grafted materials with pH‐responsive polymers, as expected when using the grafting to approach. The pH‐responsiveness of SNP‐g‐P(DMAEMA‐co‐S) and SNP‐g‐P(DEAEMA‐co‐S) was confirmed by measuring the ζ‐potential at different pH values. At acidic conditions (pH 3–6) the grafted materials were protonated and exhibited positive ζ‐potential, whereas at basic conditions (pH 10–13) the same grafted materials were deprotonated and exhibited negative ζ‐potential.
Effects of active chitosan‐flaxseed mucilage‐based films on the preservation of minced trout fillets: A comparison among aerobic, vacuum, and modified atmosphere packaging
Authors: Karami Negin , Kamkar Abolfazl , Shahbazi Yasser , Misaghi Ali
Published: July 2020

The objectives of the current study were to examine physical–mechanical, structural, and morphological characteristics of chitosan‐flaxseed mucilage films enriched with Ziziphora clinopodioides essential oil (ZEO; 0%, 0.25%, and 0.5%) and sesame oil (SO; 0% and 0.75%) and to provide useful information for the preservation of minced trout fillet's using antimicrobial films under aerobic, vacuum, and modified atmosphere conditions for 16 days. The films showed thickness, tensile strength, puncture force, puncture deformation, water vapor transmission rate, water vapor permeability, swelling index, and oxygen permeability values ranging 0.082–0.86 mm, 33.34–46.83 MPa, 25.69–53.08 N, 11.45–28.45 mm, 17.48–26.73 g/m2 h, 8.57–12.49 × 10−4 g mm/m2 h Pa, 12.45–38.43%, and 3.02–13.32 × 10−12 cm3/m2 s Pa, respectively. The following order of effect on the microbial spoilage population of treated samples was found in the applied packaging methods: modified atmosphere packaging > vacuum packaging > aerobic packaging. The final microbial population of treated samples was 0.35–4.91 log CFU/g lower than the controls after 16 days of refrigerated storage. At the end of the storage, the total volatile base nitrogen, peroxide value, and thiobarbituric acid reactive substances of untreated samples were 34.02–48.6 mg of N/100 g, 1.43–2.32 meq of peroxide/1000 g, and 3.33–4.24 mg of malondialdehyde/kg, respectively. The lowest corresponding values were recorded for the treated samples with ZEO 0.5% + SO 0.75% films by 14.26–17.73 mg of N/100 g, 0.48–0.86 meq of peroxide/1000 g, and 1.08–1.48 mg of malondialdehyde/kg, respectively.
Direct 4D‐Var assimilation of space‐borne cloud radar reflectivity and lidar backscatter. Part I: Observation operator and implementation
Authors: Fielding Mark D. , Janisková Marta
Published: July 2020

The direct assimilation of space‐borne cloud radar and lidar observations into a global numerical weather prediction model has not previously been attempted for several reasons. Firstly, the modification of a data assimilation system to handle space‐borne profiling observations is a technical challenge. Secondly, the relationship between model‐scale control variables and the relatively narrow footprint of the radar and lidar instruments were thought to be unrepresentative and too nonlinear for a variational assimilation system that is based on assumptions of linearity. However, motivation was provided when previous experiments assimilating cloud radar and lidar profiles showed, using an intermediary step to generate pseudo‐observations of temperature and humidity, that there was potential for the observations to improve both the analysis and the subsequent forecast. This article presents the developments made to facilitate the direct assimilation of cloud radar and lidar observations into the four‐dimensional variational assimilation (4D‐Var) system of the European Centre for Medium‐Range Weather Forecasts (ECMWF). A review of the observation operators shows how they have been optimised for data assimilation with an emphasis on efficiency, consistency and differentiability. A key part of this work is the specification of a new fully flow‐dependent characterisation of the observation error. By taking an error inventory approach, we account for different sources of error in a physical way. Also, to avoid degrading the analysis, careful screening, quality control and bias correction is necessary and is described herein. Finally, an initial assessment of the impact of the observations is achieved through single‐analysis tests that show that the analysis fit to the new observations is improved. In‐depth results demonstrating the impact of these observations are shown in the second part of this two‐part series.
Rapid mixing of the switch Markov chain for strongly stable degree sequences
Authors: Amanatidis Georgios , Kleer Pieter
Published: July 2020

The switch Markov chain has been extensively studied as the most natural Markov chain Monte Carlo approach for sampling graphs with prescribed degree sequences. We show that the switch chain for sampling simple undirected graphs with a given degree sequence is rapidly mixing when the degree sequence is so‐called strongly stable. Strong stability is satisfied by all degree sequences for which the switch chain was known to be rapidly mixing based on Sinclair's multicommodity flow method up until a recent manuscript of Erdős and coworkers in 2019. Our approach relies on an embedding argument, involving a Markov chain defined by Jerrum and Sinclair in 1990. This results in a much shorter proof that unifies (almost) all the rapid mixing results for the switch chain in the literature, and extends them up to sharp characterizations of P‐stable degree sequences. In particular, our work resolves an open problem posed by Greenhill and Sfragara in 2017.
Signaling a successor? A theoretical and empirical analysis of the executive compensation‐chief executive officer succession relationship
Authors: Essman Spenser M. , Schepker Donald J. , Nyberg Anthony J. , Ray Caitlin
Published: July 2020

Research Summary

Extant research rarely explores the relationship between executive compensation and chief executive officer (CEO) succession planning, despite practitioner claims that executive pay disparities indicate succession planning (in)effectiveness. Leveraging signaling theory, we use 830 succession events from 2010 to 2017 to show that pay disparity between the CEO and the highest paid non‐CEO executive is positively related to the likelihood of outside CEO succession. Thus, boards need to be aware of the implications of possible unintentional signals sent via executive compensation decisions. We do not find evidence of an interactive effect when compensation and CEO succession are co‐managed using linking pin directors—directors with compensation and CEO succession responsibilities—but supplemental analyses suggest a positive main effect of linking pin directors on the likelihood of inside CEO succession.

Managerial Summary

Powerful watchdog agencies assert that high pay differences between a firm's CEO and its next highest paid executive (CEO–HPE pay disparity) indicate succession planning challenges. This assertion has profound implications for stakeholders, but evidence supporting it is unclear. Our study examines the relationship between CEO–HPE pay disparity and the board's choice of an outside CEO, an indicator of ineffective succession planning. We find evidence that higher pay disparity signals an increased likelihood of choosing an outside CEO successor. We also find that boards who co‐manage compensation and succession may be more likely to hire an inside CEO successor. Our findings suggest that boards need to understand how compensation decisions may be inadvertently signaling future CEO succession choices.
Template Engineering of CuBi2O4 Single‐Crystal Thin Film Photocathodes
Authors: Lee Jongmin , Yoon Hongji , Choi Kyoung Soon , Kim Seungkyu , Seo Sehun , Song Jaesun , Choi Byeong‐Uk , Ryu Jiseung , Ryu Sangwoo , Oh Jihun , Jeon Cheolho , Lee Sanghan
Published: July 2020

To develop strategies for efficient photo‐electrochemical water‐splitting, it is important to understand the fundamental properties of oxide photoelectrodes by synthesizing and investigating their single‐crystal thin films. However, it is challenging to synthesize high‐quality single‐crystal thin films from copper‐based oxide photoelectrodes due to the occurrence of significant defects such as copper or oxygen vacancies and grains. Here, the CuBi2O4 (CBO) single‐crystal thin film photocathode is achieved using a NiO template layer grown on single‐crystal SrTiO3 (STO) (001) substrate via pulsed laser deposition. The NiO template layer plays a role as a buffer layer of large lattice mismatch between CBO and STO (001) substrate through domain‐matching epitaxy, and forms a type‐II band alignment with CBO, which prohibits the transfer of photogenerated electrons toward bottom electrode. The photocurrent densities of the CBO single‐crystal thin film photocathode demonstrate −0.4 and −0.7 mA cm−2 at even 0 VRHE with no severe dark current under illumination in a 0.1 m potassium phosphate buffer solution without and with H2O2 as an electron scavenger, respectively. The successful synthesis of high‐quality CBO single‐crystal thin film would be a cornerstone for the in‐depth understanding of the fundamental properties of CBO toward efficient photo‐electrochemical water‐splitting.
Generation of 2D DNA Microstructures via Topographic Control and Shearing
Authors: Park Soon Mo , Park Geonhyeong , Cha Yun Jeong , Yoon Dong Ki
Published: July 2020

2D DNA microstructures are fabricated by applying the shear force to the DNA solution on the microchannels. The “U”‐like textures of DNA are clearly observed when the mechanical shearing is applied on the aqueous DNA sample under the topographic confinement, in which the shearing direction is perpendicular to the grooves. The optical textures of U‐like microstructures are directly observed by polarized optical microscopy (POM) and laser scanning fluorescent confocal polarizing microscopy (FCPM). The DNA microstructures can be modified by varying the width, showing the multiple U‐patterns along with channel direction due to the synergistic interaction between the elastic behavior of DNA chains and topographic boundary condition. The resultant microstructures can be used to align rod‐like liquid crystals (LCs) to generate alternatively oriented nematic phase and tilted focal conic domains (FCDs) in the smectic A phase. It is believed that this approach can suggest a hint to use to DNA materials for organizing multiscale hierarchical structures of soft‐ and biomaterials.
Solution‐Processed Pure Sulfide Cu2(Zn0.6Cd0.4)SnS4 Solar Cells with Efficiency 10.8% Using Ultrathin CuO Intermediate Layer
Authors: Zhuk Siarhei , Wong Terence Kin Shun , Petrović Miloš , Kymakis Emmanuel , Hadke Shreyash Sudhakar , Lie Stener , Wong Lydia Helena , Sonar Prashant , Dey Avishek , Krishnamurthy Satheesh , Dalapati Goutam Kumar
Published: July 2020

Herein, it is demonstrated that incorporating ultrathin p‐type cupric oxide (CuO) enhances the performance and stability of solution‐processed Cu2(Zn0.6Cd0.4)SnS4 (CZCTS)/CdS thin film solar cells. In sol–gel CZCTS/CdS thin film solar cells, nanoscale CuO films (4–32 nm) are deposited on top of molybdenum (Mo) by magnetron sputtering and this is used as an intermediate layer (IL). The CuO IL thickness has a significant effect on the short‐circuit current density (JSC) in CZCTS/CdS solar cell devices. As a result, a maximum power conversion efficiency (PCE) of 10.77% is measured for the optimized device with 4 nm CuO compared with 10.03% for the reference device without a CuO layer. Furthermore, the stability of the devices is enhanced significantly by incorporating the CuO IL. This work demonstrates that through proper design of the CuO IL thickness, both the back interface quality and optical property of the CZCTS absorber can be tuned to enhance the device performance.
Message‐sensing classified transmission scheme based on mobile edge computing in the Internet of Vehicles
Authors: Zhao Haitao , Zhu Yinyang , Tang Jiawen , Han Zhe , Aujla Gagangeet Singh
Published: July 2020

With the rapid development of intelligent transportation, vehicle terminals generate a large number of data messages that need to be processed in real time, and the required computing and storage resources far exceed the load capacity of vehicle terminals. Mobile edge computing enables data resources to be processed near device terminals, and provides low‐latency and high‐reliability computing services to meet the power and service quality requirements of terminal devices. Therefore, in order to achieve better data resource management, this paper introduces mobile edge computing technology, and mainly researches secure message transmission optimization algorithms based on mobile edge computing. Firstly, we prioritize secure messages through the analytic hierarchy process. This can guarantee that the most urgent messages get the highest transmission level. Secondly, we establish an optimal task offloading model of delay and energy loss by assigning different weight factors to delay and energy loss. The Lagrangian relaxation method is used to transform the nonconvex problem into a convex problem. We use greedy algorithm to solve the main problem. Finally, the vehicle transmits secure messages through the topology of the local network within its defined communication range. Performance evaluation results show that the scheme not only reduces the redundant transmission of messages, but also improves the performance of end‐to‐end delay and message deliver success ratio of secure messages.
Effects of Finish Rolling Temperature and Deformation on Microstructural Evolution and Precipitation Behavior of Non‐quenched and Tempered Carbide‐Free Bainitic Steel
Authors: Chen Xi , Yang Zhanbing , Wang Fuming , Li Changrong
Published: July 2020

Double compression tests are carried out to investigate the microstructural evolution and precipitation behavior of Nb–Ti microalloyed carbide‐free bainitic steel under different finish rolling conditions. With decreasing finish rolling temperature and increasing finish rolling deformation, the area fraction of lath bainite (LB) and martensite (M) was increased, the width of bainitic ferrite lath was decreased, the dislocation density and the number fraction of high‐angle grain boundaries are raised. Meanwhile, the larger deformation and lower temperature reduce the amount of retained austenite (RA) and refine the precipitated particles, which benefit the performance further. Hence, the phase transformation strengthening, refinement strengthening, dislocation strengthening, and precipitation strengthening synergistically contribute to the increase in hardness with increasing deformation and decreasing temperature.