bluuebunny/crossref_metadata_2025 huggingface dataset:
Niche determinants in a salamander complex: Does hybridism or reproductive parasitism explain patterns of distribution?
Authors: Mills Peter B. , Hossie Thomas J. , Murray Dennis L.
Published: October 2020

Organisms with multiple biotic attributes may also have conflicting niche determinants, and we assessed whether the realized niche reflects single or multiple biotic attributes. A group of all‐female salamanders found in eastern North America (unisexual salamanders; Ambystoma spp.) embody two potentially competing biotic states: hybridism and obligate reproductive parasitism. In theory, hybrids should occupy areas that are transitional to those used by parental species, parasites must live in syntopy with their hosts, and parasites that engage in ecological competition with hosts should be most successful in habitats that are moderately suitable for hosts. We built niche models for bisexual salamanders (Ambystoma laterale and Ambystoma jeffersonianum), as well as for unisexual Ambystoma that posses nuclear DNA from both of these species. These unisexuals are both phenotypic hybrids and obligate reproductive parasites of the bisexual species. We characterized realized niches predicted for unisexual Ambystoma via a hybrid‐framework model (e.g., using environmental predictors) and a parasite‐framework model (e.g., using host suitability predictors). Model validation using ancillary data permitted evaluation of which biotic state (hybrid vs. parasite) fit the observed patterns of occupancy. The hybrid model conformed strongly with predictions that the unisexual niche would be transitional between A. laterale and A. jeffersonianum bisexuals. Average annual temperatures and terrestrial salamander species richness (a proxy for competition) were particularly descriptive of parental niches and hybrid occupancy of transitional environments. While the parasite model behaved as expected, model validation did not fully corroborate its utility for determining patterns of occupancy. Instead, model selection revealed that the hybrid model was more descriptive of unisexual occurrence than the parasite model. Despite the fundamental importance of reproductive parasitism to the persistence of unisexual Ambystoma, we suggest that hybridism has greater contribution to the realized niche. When species have competing ecological attributes, one primary biotic state may dominate as a determinant of the realized niche.
Left ventricular systolic ejection time is an independent predictor of all‐cause mortality in heart failure with reduced ejection fraction
Authors: Alhakak Alia S. , Sengeløv Morten , Jørgensen Peter G. , Bruun Niels E. , Johnsen Cecilie , Abildgaard Ulrik , Iversen Allan Z. , Hansen Thomas F. , Teerlink John R. , Malik Fady I. , Solomon Scott D. , Gislason Gunnar , Biering‐Sørensen Tor
Published: October 2020

Aims

Colour tissue Doppler imaging (TDI) M‐mode through the mitral leaflet is an easy and precise method to obtain cardiac time intervals including isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT) and systolic ejection time (SET). The myocardial performance index (MPI) is defined as [(IVCT + IVRT)/SET]. Whether cardiac time intervals obtained by the TDI M‐mode method can be used to predict outcome in patients with heart failure with reduced ejection fraction (HFrEF) remains unknown.

Methods and results

A total of 997 patients with HFrEF (mean age 67 ± 11 years, 74% male) underwent an echocardiographic examination including TDI. During a median follow‐up of 3.4 years (interquartile range 1.9–4.8 years), 165 (17%) patients died. The risk of mortality increased by 9% per 10 ms decrease in SET [per 10 ms decrease: hazard ratio (HR) 1.09, 95% confidence interval (CI) 1.06–1.13; P < 0.001]. The association remained significant even after multivariable adjustment for clinical and echocardiographic parameters (per 10 ms decrease: HR 1.06, 95% CI 1.01–1.11; P = 0.030). The MPI was a significant predictor in an unadjusted model (per 0.1 increase: HR 3.06, 95% CI 1.16–8.06; P = 0.023). However, the association did not remain significant after multivariable adjustment. No significant associations between IVCT or IVRT and mortality were found in unadjusted nor adjusted models. Additionally, SET provided incremental prognostic information with regard to predicting mortality when added to established clinical predictors of mortality in patients with HFrEF.

Conclusion

In patients with HFrEF, SET provides independent and incremental prognostic information regarding all‐cause mortality.
A Poly(Propylene Imine) Dendrimer and Carbon Black Modified Flexible Screen Printed Electrochemical Sensor for Lead and Cadmium Co‐detection
Authors: Mazzaracchio Vincenzo , Tshwenya Luthando , Moscone Danila , Arduini Fabiana , Arotiba Omotayo A.
Published: October 2020

Towards the development of miniaturised and low‐cost sensors for heavy metals detection in water, herein we describe an electrochemical sensor for the co‐detection of lead and cadmium. The sensor was developed using screen‐printed electrode modified with a composite of poly(propylene imine) dendrimer and carbon black. The electrode was modified by drop casting of the carbon black and electrodeposition of the poly(propylene imine) dendrimer. This modified electrode (sensor) was characterised by cyclic voltammetry and electrochemical impedance spectroscopy, revealing improved electrochemical performances. Square wave anodic stripping voltammetry (SWASV) was used to achieve the simultaneous detection of Pb(II) and Cd(II) at trace level, obtaining satisfactory LOD of 3.6 ppb and 15.3 ppb respectively; and sensitivity of 0.49 μA/ppb and 0.57 μA/ppb in tap water.
Synthesis, Characterization of Cr Doped TeO2 Nanostructures and its Application as EGFET pH Sensor
Authors: Adimule Vinayak , Revaiah R. G. , Nandi Santosh S. , Jagadeesha Adarsha Haramballi
Published: October 2020

In the present work, Cr doped tellurium dioxide nanostructures (CTO NS)(1 wt %, 6 wt %, 8 wt % and 12 wt %) synthesized by co precipitation method and characterized by CV, UV‐Visible, SEM, XRD, XPS spectroscopic analysis. Electron beam deposited thin film of CTO NS having 12 wt % of Cr exhibited EGFET‐pH sensitivity of 62.03 mV/pH at 250 °C in buffer solutions of pH 6–12, linearity 0.9345, drift rate of 1.12 mV/h and deviation of 0.01145 as compared with 1 wt %, 6 wt % and 8 wt % of CTO NS.
Parking recommender system privacy preservation through anonymization and differential privacy
Authors: Saleem Yasir , Rehmani Mubashir Husain , Crespi Noel , Minerva Roberto
Published: October 2020

Recent advancements in the Internet of Things (IoT) have enabled the development of smart parking systems that use services of third‐party parking recommender system to provide recommendations of personalized parking spot to users based on their past experience. However, the indiscriminate sharing of users' data with an untrusted (or semitrusted) parking recommender system may breach the privacy because users' behavior and mobility patterns could be inferred by analyzing their past history. Therefore, in this article, we present two solutions that preserve privacy of users in parking recommender systems while analyzing the past parking history usingk‐anonymity (anonymization) and differential privacy (perturbation) techniques. Specifically, given an original parking database containing users' parking information, thek‐anonymity mechanism constructs an anonymized database, while differential privacy perturbs the query response using the Laplace mechanism, making the users indistinguishable in both approaches, hence preserving the privacy. Experimental results on a data set constructed from real parking measurements evaluate the trade‐off between privacy and utility, therefore enabling users to receive parking spots recommendations while preserving their privacy.
Visible‐Light‐Driven Electrocatalytic Oxygen Evolution Reaction: NiFe2O4/NiFe–Layered Double Hydroxide Z‐Scheme Heteronanosheet as a Model
Authors: Yan Lei , Ren Yanrong , Shen Junling , Wang Haiyan , Ning Jiqiang , Zhong Yijun , Hu Yong
Published: October 2020

A visible‐light‐driven electronic structure regulation strategy is developed to boost the oxygen evolution reaction (OER) activity of the nickel ferrite (NiFe2O4)/NiFe–layered double hydroxide (LDH) electrocatalyst whose typical Z‐scheme heterostructure makes it an ideal model to explore the mechanisms of photogenerated carriers in the electrocatalytic OER. The oxidation current of the composite increases significantly under visible light irradiation, resulting in a dramatic drop in the overpotential to 180 mV at a current density of 10 mA cm−2. The Z‐scheme heterostructure with efficient charge separation promotes photogenerated electron transfer from NiFe2O4 to NiFe–LDH, leading to the formation of an electron‐rich Ni and Fe sites in NiFe–LDH and abundant photogenerated holes left in NiFe2O4, which are responsible for the improved electrocatalytic performance. Herein, the important role of photoactivated electron structure regulation in electrocatalysis is highlighted.
Inorganic salt hydrate for thermal energy storage application: A review
Authors: Purohit B. K. , Sistla V. S.
Published: October 2020

Salt hydrates are one of the most common inorganic compounds that are used as phase change material (PCM). These are available for a wide range of phase transition temperature for thermal energy storage (TES) application. They have some most desired properties for TES applications like high latent heat value, good thermal conductivity, nonexpensive, and were nonflammable. Besides these, due to the undesirable properties like phase segregation, supercooling, and corrosion to the containers, this PCM not recommended for TES application. To mitigate these issues and to make salt hydrates suitable in TES application, much research has been carried out in past years. This main highlight of this article is to provide a comprehensive overview of the use of salt hydrates, their applications and summarize the research outcomes reported by various researchers to every issue for its TES application. This summarized information will be useful to those who are interested to work on this research area. Along with this literature focuses on the advantages, disadvantages, and mechanism of salt hydrates for TES system during its thermal cycle process.
Perforator‐based propeller flaps for reconstruction of massive anterolateral thigh donor site wounds
Authors: Hudson Caroline S. , Huang Andrew T.
Published: October 2020

Background

Wide anterolateral thigh (ALT) flap donor site defects may make primary closure difficult or impossible, with split thickness skin grafting and/or negative pressure therapy often used instead. Here, we describe a technique using propeller flaps based on varying thigh perforating vasculature in donor site reconstruction for these larger deformities.

Methods

Case series

Results

Three patients are described that had perforator‐based propeller flap reconstruction of large ALT donor site wounds that were not amenable to primary closure. Two propeller flaps were supplied by perforators of the transverse branch of the lateral circumflex femoral artery and one by a perforator of the deep femoral system. One patient experienced partial loss of the propeller flap, but completely healed with local wound care.

Conclusion

The propeller flap is a safe method to reconstruct large ALT donor sites not amenable to primary closure.
Staying smoke‐free: Factors associated with nonsmoking among urban Aboriginal adolescents in the Study of Environment on Aboriginal Resilience and Child Health (SEARCH)
Authors: Heris Christina , Thurber Katherine A , Wright Darryl , Thomas David , Chamberlain Catherine , Gubhaju Lina , Sherriff Simone , McNamara Bridgette , Banks Emily , Smith Natalie , Eades Sandra
Published: October 2020

Issue addressed

To examine the factors associated with preventing regular smoking among Aboriginal adolescents.

Methods

Cross‐sectional analysis of data from 106 Aboriginal adolescents aged 12‐17 years, and their caregivers, from four Aboriginal Community Controlled Health Services in urban New South Wales, 2008‐2012. The relation of individual, social, environmental and cultural factors to having ‘never’ smoked tobacco regularly was examined using Poisson regression.

Results

Overall, 83% of adolescents had never smoked regularly; 13 reported current and five past smoking. Most lived in smoke‐free homes (60%) despite 75% reporting at least one current smoker caregiver. Participants were significantly more likely to have never smoked regularly if they had good mental health (PR = 1.4, 95% CI: 1.1‐1.9), their mother as their primary caregiver (1.3, 1.0‐1.6), good family relationships (1.2, 1.0‐1.5), stable housing (1.3, 1.1‐1.7), had never used alcohol (1.8, 1.3‐2.4), were not sexually active (3.1, 1.3‐ 7.2) and had no criminal justice interactions (1.8, 1.2‐2.8).

Conclusions

Most participants lived in smoke‐free homes and the vast majority had never smoked regularly. Promoting good mental health and strengthening social connections may be protective against smoking as those experiencing less social disruption were more likely to have never smoked regularly. Smoking may be an indicator of psychosocial conditions and a prompt for screening and simultaneous treatment.

So what?

Organisations should be resourced to deliver holistic adolescent health promotion programs. Programs and policies should support positive family relationships and stable housing as this may protect against the uptake of regular smoking.
Informant discrepancies in the rating of Chinese preschoolers' approaches to learning: Looking for the role of parent–teacher relationships
Authors: Ren Lixin , Fan Jieqiong
Published: October 2020

Ratings from multiple informants, such as parents and teachers, are often used in child development research. Although informant discrepancies have been the rule rather than the exception, factors that may contribute to such discrepancies are not well understood. This study examined the role of parent–teacher relationships in the discrepancies between parents' and teachers' ratings of approaches to learning in Chinese preschoolers. Data were collected from the parents and teachers of 354 Chinese children (Mage = 5.26 years). Discrepancies between parents' and teachers' ratings were analysed, and poor agreement was found. Better parent–teacher relationships slightly contributed to smaller parent–teacher discrepancies on ratings of children's attention/persistence and competence motivation. The findings suggest that strategies promoting parent–teacher relationships may improve the consistency between parents' and teachers' view on children's learning behaviours to some degree. The observed discrepancies also imply that multi‐informant ratings are imperative to achieve comprehensive understandings of children's behaviour.

This study examined the role of parent–teacher relationships in cross‐informant discrepancies on ratings of Chinese preschoolers' approaches to learning.

Remarkable discrepancies were found between parents' and teachers' ratings. Better parent–teacher relationships were related to smaller discrepancies.

Improving parent–teacher relationships can help families and schools achieve a more congruent perception of young children's learning behaviours.
Chronic toxicity of 50 metals to Ceriodaphnia dubia
Authors: Okamoto Akira , Masunaga Shigeki , Tatarazako Norihisa
Published: October 2020

Metals are essential elements for human life but may cause disorders when exposure is excessive. Previously, we reported on the acute toxicity of 50 metals; however, the chronic toxicity data of some metals are not available. Therefore, we conducted chronic toxicity tests to determine the effects of 50 metals on the water flea, Ceriodaphnia dubia. The IC20 of 20 metals (Be, Sc, Cr, Co, Ni, Cu, Zn, Y, Ru, Ag, Cd, In, Te, W, Os, Pt, Au, Hg, Tl and Pb) were <100 μg/L; nine metals (Al, V, As, Se, Zr, Nb, Rh, Sb and Bi) were 100 ≤ IC20 < 1000 μg/L; 16 metals (Li, Mg, K, Ti, Mn, Fe, Ga, Ge, Rb, Sr, Mo, Sn, Cs, Ba, Re and Ir) were 1000 ≤ IC20 ≤ 100 000 μg/L; and two metals (Na and Ca) were >100 000 μg/L. Three metals (Pd, Hf and Ta) did not show IC20 at the upper limit of respective aqueous solubility, and IC20s were not obtained. The maximum test concentrations (almost aqueous solubility) of Pd, Hf and Ta were 83, 2400 and 5.3 μg/L, respectively. These data show the high correlation between our IC50s for C. dubia and those for Dahpnia magna published previously. The IC50s of 47 metals were not correlated with electronegativity, first ionization energy, atomic weight, atomic number, covalent radius, atomic radius or ionic radius.
High levels of modified ceramides are a defining feature of murine and human cancer cachexia
Authors: Morigny Pauline , Zuber Julia , Haid Mark , Kaltenecker Doris , Riols Fabien , Lima Joanna D.C. , Simoes Estefania , Otoch José Pinhata , Schmidt Sören Fisker , Herzig Stephan , Adamski Jerzy , Seelaender Marilia , Berriel Diaz Mauricio , Rohm Maria
Published: October 2020

Background

Cancer cachexia (CCx) is a multifactorial energy‐wasting syndrome reducing the efficiency of anti‐cancer therapies, quality of life, and survival of cancer patients. In the past years, most studies focused on the identification of tumour and host‐derived proteins contributing to CCx. However, there is still a lack of studies addressing the changes in bioactive lipids. The aim of this study was to identify specific lipid species as a hallmark of CCx by performing a broad range lipid analysis of plasma from well‐established CCx mouse models as well as cachectic and weight stable cancer patients.

Methods

Plasma from non‐cachectic (PBS‐injected mice, NC26 tumour‐bearing mice), pre‐cachectic and cachectic mice (C26 and LLC tumour‐bearing mice, ApcMin/+ mutant mice), and plasma from weight stable and cachectic patients with gastrointestinal cancer, were analysed using the Lipidyzer™ platform. In total, 13 lipid classes and more than 1100 lipid species, including sphingolipids, neutral and polar glycerolipids, were covered by the analysis. Correlation analysis between specific lipid species and readouts of CCx were performed. Lipidomics data were confirmed by gene expression analysis of metabolic organs to analyse enzymes involved in sphingolipid synthesis and degradation.

Results

A decrease in several lysophosphatidylcholine (LPC) species and an increase in numerous sphingolipids including sphingomyelins (SMs), ceramides (CERs), hexosyl‐ceramides (HCERs) and lactosyl‐ceramides (LCERs), were mutual features of CCx in both mice and cancer patients. Notably, sphingolipid levels gradually increased during cachexia development. Key enzymes involved in ceramide synthesis were elevated in liver but not in adipose, muscle, or tumour tissues, suggesting that ceramide turnover in the liver is a major contributor to elevated sphingolipid levels in CCx. LPC(16:1), LPC(20:3), SM(16:0), SM(24:1), CER(16:0), CER(24:1), HCER(16:0), and HCER(24:1) were the most consistently affected lipid species between mice and humans and correlated negatively (LPCs) or positively (SMs, CERs and HCERs) with the severity of body weight loss.

Conclusions

High levels of sphingolipids, specifically ceramides and modified ceramides, are a defining feature of murine and human CCx and may contribute to tissue wasting and skeletal muscle atrophy through the inhibition of anabolic signals. The progressive increase in sphingolipids during cachexia development supports their potential as early biomarkers for CCx.
Production of [68Ga]Ga‐PSMA: Comparing a manual kit‐based method with a module‐based automated synthesis approach
Authors: Kleynhans Janke , Rubow Sietske , le Roux Jannie , Marjanovic‐Painter Biljana , Zeevaart Jan Rijn , Ebenhan Thomas
Published: October 2020

The labeling of peptides with gallium‐68 is often initially performed by manual labeling, but with high clinical demand, other alternatives are needed. Cold‐kits or automated synthesis are viable options for standardized methods and deemed pharmaceutically more acceptable. This study compares these [68Ga]Ga‐PSMA‐11 production methods. Data from 40 kit‐based and 40 automated syntheses of [68Ga]Ga‐PSMA‐11 were analyzed. Pre‐set criteria were evaluated including radiochemical purity, radionuclidic purity, chemical purity, physiological acceptability and sterility. The operator time and radiation dose received were measured. The robustness and repeatability of each method were assessed and a comparison of the running costs of each method is also provided. For both the methods all the analyzed products met the release criteria. No differences were found in radiochemical purity, radiochemical identity, radionuclidic purity, and sterility. However, radiochemical yield and apparent molar activity showed significant differences. For both methods, whole body radiation exposure to operators was lower than with manual labeling (25 – 40 μSv). The exposure during kit‐based labeling (14.5 ± μSv) was seven times higher than that of automated synthesis (2.05 ± 0.99 μSv). The automated synthesis was the more expensive method. Both methods are sound alternatives to manual synthesis and offer higher quality, better radiation protection and a more reliable manufacturing of radiopharmaceuticals.
Gait mechanics are influenced by quadriceps strength, age, and sex after total knee arthroplasty
Authors: Christensen Jesse C. , Capin Jacob J. , Hinrichs Lauren A. , Aljehani Moiyad , Stevens‐Lapsley Jennifer E. , Zeni Joseph A.
Published: October 2020

Although most patients are satisfied with outcomes after total knee arthroplasty (TKA), many retain preoperative altered gait mechanics. Identifying patient characteristics associated with gait mechanics will improve rehabilitation strategies and enhance our understanding of movement disorders. Therefore, the purpose of this study was to identify which patient characteristics are related to gait mechanics in the surgical limb during walking post‐TKA. Patient characteristics included age, body mass, sex, quadriceps strength, self‐reported function, and knee pain. General linear regression was used to compare patient characteristics associated with gait mechanics, after controlling for gait speed, functional capacity and time from surgery. We tested 191 patients cross‐sectionally at 6–24 months after primary, unilateral TKA. Quadriceps weakness in the surgical limb was associated with less peak vertical ground reaction force (PvGRF) (β = .245, p = .044), knee extension moment (β = .283, p = .049), and knee extension excursion (β = .298, p = .038). Older age (β = .168, p = .050) was associated with less PvGRF. Quadriceps strength in the nonsurgical limb (β = −.357, p = .021) was associated with greater knee extension excursion in the surgical limb. Females with TKA (β = −.276, p = .007) had less knee flexion excursion compared to males. Faster gait speed was also associated with greater PvGRF (β = .585, p < .001), knee extensor moment (β = .481, p < .001), and knee flexion excursion (β = .318, p < .001). Statement of Clinical Significance: This study showed quadriceps weakness, slower gait speed, older age and being female were related to altered gait mechanics post‐TKA. These findings will help clinicians better educate patients and develop targeted interventions for improving care in patients post‐TKA.
Relationship of Patent Ductus Arteriosus Echocardiographic Markers With Descending Aorta Diastolic Flow
Authors: Martins Fernando de Freitas , Bassani Diego G. , Rios Daniel Ibarra , Resende Maura Helena F. , Weisz Dany , Jain Amish , Lopes Jose Maria de Andrade , McNamara Patrick J.
Published: October 2020

Objectives

To characterize the relationship of echocardiographic markers of left heart overload and flow in peripheral major end‐organ vessels (eg, celiac artery) with the presence of reversed holodiastolic flow in the descending aorta, considered a surrogate marker of an increased transductal shunt volume, in preterm patients with a patent ductus arteriosus (PDA).

Methods

This work was a retrospective study of data from echocardiography performed to investigate the hemodynamic significance of a PDA in preterm patients. We studied differences in echocardiographic markers of the PDA shunt volume according to patterns of flow in the postductal descending aorta (no PDA, PDA with antegrade diastolic flow, and PDA with reversed diastolic flow). The strength of the association between each echocardiographic marker and the presence of aortic holodiastolic flow reversal was investigated.

Results

We studied 137 patients with a median (interquartile range) birth weight of 850 (694–1030) g and a median gestational age of 25 (24–27) weeks. Among patients with a PDA (113), those with diastolic flow reversal in the descending aorta (44) presented had increased echocardiographic markers representative of the shunt volume (increased left ventricular output, left atrial‐to‐aortic ratio, pulmonary vein D wave, and shorter isovolumic relaxation time) compared to those with aortic antegrade diastolic flow. A positive, albeit weak, correlation between diastolic flow reversal and shunt volume echocardiographic markers was found. Abnormal diastolic flow in the celiac artery had the strongest correlation (R2 = 0.24).

Conclusions

In preterm patients with a PDA, echocardiographic markers of the shunt volume were more abnormal in patients with reversed diastolic flow in the descending aorta. These data support the assumption that variance in these markers are related to the shunt volume, which needs consideration when adjudicating hemodynamic significance.
Poly(L‐Glutamic Acid)‐Drug Conjugates for Chemo‐ and Photodynamic Combination Therapy
Authors: Yu Haiyang , Bao Yanli , Xu Caina , Chen Li , Tang Zhaohui
Published: October 2020

Despite the polymeric vascular disrupting agent (poly(L‐glutamic acid)‐graft‐methoxy poly(ethylene glycol)/combretastatin A4) nanoparticles can efficiently inhibit cancer growth, their further application is still a challenge owing to the tumor recurrence and metastasis after treatment. In this study, two poly(L‐glutamic acid)‐drug conjugates for chemo‐and photodynamic combination therapy are fabricated. PLG‐g‐mPEG‐CA4 nanoparticles are prepared by combretastatin A4 (CA4) and poly(L‐glutamic acid)‐graft‐methoxy poly(ethylene glycol) (PLG‐g‐mPEG) using the Yamaguchi esterification reaction. PLG‐g‐mPEG‐TPP (TPP: 5, 10, 15, 20‐tetraphenylporphyrin) nanoparticles are constructed using PLG‐g‐mPEG and amine porphyrin through condensation reaction between carboxyl group of PLG‐g‐mPEG and amino group of porphyrin. The results showed that PLG‐g‐mPEG‐CA4 nanoparticles have good antitumor ability. PLG‐g‐mPEG‐TPP nanoparticles can produce singlet oxygen under the laser irradiation. Moreover, the combined therapy of PLG‐g‐mPEG‐CA4 and PLG‐g‐mPEG‐TPP nanoparticles has higher antitumor effect than the single chemotherapy or the single photodynamic therapy in vitro. The combination of CA4 nondrug and photodynamic therapy provides a new insight for enhancing the tumor therapeutic effect with vascular disrupting agents and other therapy.
Polymer Grafting of Boron Nitride Nanosheets via Reduction Chemistry and Their Reinforcement for Polymeric Composite
Authors: He Zhiyan , Zhao Jian , Guo Fuhai , Zhang Deli , Guo Hongge , Hu Haiqing
Published: October 2020

Covalent functionalization of hexagonal boron nitride nanosheets (BNNSs) is very challenging because of their surface inactivity. In this work, a simple reductive activation method is reported to covalently decorate BNNSs with polymers. BNNSs are initially negatively charged through effective reductive treatment and subsequently reacted with bromine‐terminated poly(methyl methacrylate) chains bearing different molecular weights to obtain a series of polymer‐grafted BNNSs, which greatly enhances their compatibility and dispersibility within acetone. With the increase of the molecular weight, grafting ratio and the density of grafted chains on BNNS surfaces show decreasing trends due to steric hinderance. Addition of functionalized BNNSs at a low filler content significantly improves reinforcement performance for polymer composites. The functionalization via the reduction treatment represents a novel and versatile route to anchor a range of functionalized species to manipulate surface chemistry toward the production of functional BNNSs for broad applications.
Social media influencers: A route to brand engagement for their followers
Authors: Delbaere Marjorie , Michael Brittany , Phillips Barbara J.
Published: October 2020

Social Media Influencers (SMIs) are micro‐celebrities with large followings on social media platforms who engage consumers and hold the potential to promote customer‐brand relationships across different product categories. SMIs have an existing relationship of trust with consumers, and consumers seek out the content created by SMIs for valuable information and advice. This study explores the process of brand engagement between consumers and brands in the digital content marketing environment, specifically examining the research question: Do SMIs act as a route to brand engagement for their followers? The context for this study is the beauty community on YouTube; over 60,000 user comments were analyzed through automated text analysis. This study is among the first to provide empirical evidence that SMIs do act as a route to brand engagement through the three dimensions of cognitive processing, affection and activation.
Influence of tilting effect on charge structure and lightning flash density in two different convective environments
Authors: Gharaylou Maryam , Pegahfar Nafiseh , Farahani Majid M.
Published: October 2020

The influence of the tilting effect on charge density and lightning flash density was investigated using idealized Weather Research and Forecasting explicit charging/discharge module (WRF‐ELEC) simulations for two thunderclouds. No shear (NS) and with shear (WS) simulations were conducted based on different values of wind velocity components in input sounding. Results from the NS and WS simulations show that the tilting effect extended the lifetime of the simulated convective clouds in both case studies, while leading to higher maximum vertical velocity only for the environment with intense convection. The ice and graupel in the cloud cell appear almost simultaneously in both the NS and WS simulations for the two case studies, but larger values are obtained for the WS simulations. It is noted that the increase of convection intensity postpones the larger values to the mature stage. The tilting effect results in an increase of total non‐inductive charging, especially in a severe thundercloud. Moreover, the tilting effect does not lead to the same results for the polarity and intensity of charge density in the two studied cases. In the real case study, a dipolar charge structure was seen for both NS and WS simulations, but the intensity of charge density decreased with regard to the tilting effect. In contrast, the intensity of the charge increased with the tilting effect and resulted in tripolarity in the idealized case with a high value of convective available potential energy. Finally, considering the tilting effect leads to an increase of the number of lightning occurrences in the two case studies.
Existence and nonexistence results for a class of fourth‐order coupled singular boundary value problems arising in the theory of epitaxial growth
Authors: Verma Amit K. , Pandit Biswajit , Agarwal Ravi P.
Published: October 2020

In this article, we propose novel coupled nonlinear singular boundary value problems arising in epitaxial growth theory. The coupled equations are nonlinear, non‐self‐adjoint, and singular and have no exact solutions. We derive some qualitative properties of the coupled solutions, which depend on the size of parameters that occur in the coupled system. To prove the existence of the coupled solutions, we apply the monotone iterative technique on equivalent coupled integral equations in the presence of upper and lower solutions. We also compute the bounds for the parameters, which indicates the existence of coupled solutions for small values of the parameters, and nonexistence for large positive values of these parameters. To illustrate the theory developed, we consider test cases and compute the sequence of upper and lower solutions. To verify the bounds on the parameters, we have used a type of Adomian decomposition method.
A parameter‐uniform scheme for the parabolic singularly perturbed problem with a delay in time
Authors: Kumar Devendra
Published: October 2020

In this paper, a parameter‐uniform numerical scheme for the solution of singularly perturbed parabolic convection–diffusion problems with a delay in time defined on a rectangular domain is suggested. The presence of the small diffusion parameterϵleads to a parabolic right boundary layer. A collocation method consisting of cubicB‐spline basis functions on an appropriate piecewise‐uniform mesh is used to discretize the system of ordinary differential equations obtained by using Rothe's method on an equidistant mesh in the temporal direction. The parameter‐uniform convergence of the method is shown by establishing the theoretical error bounds. The numerical results of the test problems validate the theoretical error bounds.
The relationship between e‐learning and academic performance of students
Authors: Rasheed Hafiz Muhammad Wasif , He Yuanqiong , Khalid Junaid , Khizar Hafiz Muhammad Usman , Sharif Suhail
Published: October 2020

The purpose of this paper is to investigate the relationship of service quality dimensions (tangibility, responsiveness, assurance, reliability, empathy, and e‐learning) on student's academic performance through student motivation, and student satisfaction. Primary data were collected from 384 participants studying in higher education institutes (HEI's) in the Punjab province of Pakistan and the research model was empirically tested. The findings reveal that all service quality dimensions (tangibility, responsiveness, assurance, reliability, empathy, and e‐learning) are positively associated with student's academic performance through student's motivation and student satisfaction. This study makes a substantial contribution to the literature of service quality, by adding a novel dimension “e‐learning” into the most renowned and frequently used SERVQUAL (tangibility, reliability, empathy, assurance, and responsiveness) model. By doing so we not only establish the link between e‐learning and student's academic performance through student satisfaction and student motivation but also extended the SERVQUAL model by incorporating an important neglected area.
The burden of respiratory syncytial virus infections among children with sickle cell disease
Authors: Rostad Christina A. , Maillis Alexander N. , Lai Kristina , Bakshi Nitya , Jerris Robert C. , Lane Peter A. , Yee Marianne E. , Yildirim Inci
Published: October 2020

Background

Although respiratory syncytial virus (RSV) is the leading cause of pediatric lower respiratory tract infections, the burden of RSV in children with sickle cell disease (SCD) is unknown.

Methods

We conducted a retrospective, nested, case‐control study of children with SCD <18 years who had respiratory viral panels (RVPs) performed at Children's Healthcare of Atlanta from 2012 to 2019. We abstracted the medical records to describe the demographics, clinical features, and outcomes of children who tested positive for RSV (cases) versus children who tested negative (controls). We calculated the annual incidence of RSV and related hospitalization rates with 95% confidence intervals (CIs) and used multivariate logistic regression to evaluate associations.

Results

We identified 3676 RVP tests performed on 2636 patients over seven respiratory seasons resulting in 219/3676 (6.0%) RSV‐positive tests among 160/2636 (6.1%) patients. The average annual incidence of laboratory‐confirmed RSV infection among children with SCD was 34.3 (95% CI 18.7‐49.8) and 3.8 (95% CI 0.5‐7.0) cases per 1000 person‐years for those <5 years and 5‐18 years, respectively. The RSV‐related hospitalization rate for children <5 years was 20.7 (95% CI 8.5‐32.8) per 1000 person‐years. RSV‐positive cases were significantly younger than RSV‐negative patients (3.8 years vs 7.6 years, P < .001). Of RSV‐positive cases, 22 (13.8%) developed acute chest syndrome and nine (5.6%) required intensive care, which was not significantly different from RSV‐negative children with SCD.

Conclusion

RSV infections are common in children with SCD with higher burden in younger patients. RSV is associated with considerable morbidity, including higher rates of hospitalization compared to the general population.
Comparison of influenza type A and B with COVID‐19: A global systematic review and meta‐analysis on clinical, laboratory and radiographic findings
Authors: Pormohammad Ali , Ghorbani Saied , Khatami Alireza , Razizadeh Mohammad Hossein , Alborzi Ehsan , Zarei Mohammad , Idrovo Juan‐Pablo , Turner Raymond J.
Published: October 2020

We compared clinical symptoms, laboratory findings, radiographic signs and outcomes of COVID‐19 and influenza to identify unique features. Depending on the heterogeneity test, we used either random or fixed‐effect models to analyse the appropriateness of the pooled results. Overall, 540 articles included in this study; 75,164 cases of COVID‐19 (157 studies), 113,818 influenza type A (251 studies) and 9266 influenza type B patients (47 studies) were included. Runny nose, dyspnoea, sore throat and rhinorrhoea were less frequent symptoms in COVID‐19 cases (14%, 15%, 11.5% and 9.5%, respectively) in comparison to influenza type A (70%, 45.5%, 49% and 44.5%, respectively) and type B (74%, 33%, 38% and 49%, respectively). Most of the patients with COVID‐19 had abnormal chest radiology (84%, p < 0.001) in comparison to influenza type A (57%, p < 0.001) and B (33%, p < 0.001). The incubation period in COVID‐19 (6.4 days estimated) was longer than influenza type A (3.4 days). Likewise, the duration of hospitalization in COVID‐19 patients (14 days) was longer than influenza type A (6.5 days) and influenza type B (6.7 days). Case fatality rate of hospitalized patients in COVID‐19 (6.5%, p < 0.001), influenza type A (6%, p < 0.001) and influenza type B was 3%(p < 0.001). The results showed that COVID‐19 and influenza had many differences in clinical manifestations and radiographic findings. Due to the lack of effective medication or vaccine for COVID‐19, timely detection of this viral infection and distinguishing from influenza are very important.
Fixed‐time sliding mode cooperative control for multiagent networks via event‐triggered strategy
Authors: Song Ge , Shi Peng , Agarwal Ramesh K.
Published: October 2020

In this article, the problem of event‐triggered‐based fixed‐time sliding mode cooperative control is addressed for a class of leader‐follower multiagent networks with bounded perturbation. First, a terminal integral sliding mode manifold with fast convergent speed is designed. Then, a distributed consensus tracking control strategy based on event‐triggered and sliding mode control is developed that guarantees the multiagent networks achieve consensus within a fixed time which is independent of initial states of agents in comparison with the finite‐time convergence. Furthermore, the update frequency of control law can be considerably reduced and Zeno behavior can be removed by utilizing the proposed event‐triggered control algorithm. Simulation examples are used to show the effectiveness of the new control protocol.
Progenitor cell therapy for acquired pediatric nervous system injury: Traumatic brain injury and acquired sensorineural hearing loss
Authors: Baumgartner James E. , Baumgartner Linda S. , Baumgartner Michael E. , Moore Ernest J. , Messina Steven A. , Seidman Michael D. , Shook David R.
Published: October 2020

While cell therapies hold remarkable promise for replacing injured cells and repairing damaged tissues, cell replacement is not the only means by which these therapies can achieve therapeutic effect. For example, recent publications show that treatment with varieties of adult, multipotent stem cells can improve outcomes in patients with neurological conditions such as traumatic brain injury and hearing loss without directly replacing damaged or lost cells. As the immune system plays a central role in injury response and tissue repair, we here suggest that multipotent stem cell therapies achieve therapeutic effect by altering the immune response to injury, thereby limiting damage due to inflammation and possibly promoting repair. These findings argue for a broader understanding of the mechanisms by which cell therapies can benefit patients.
Rabbit neurospheres as a novel in vitro tool for studying neurodevelopmental effects induced by intrauterine growth restriction
Authors: Barenys Marta , Illa Miriam , Hofrichter Maxi , Loreiro Carla , Pla Laura , Klose Jördis , Kühne Britta Anna , Gómez-Catalán Jesús , Braun Jan Matthias , Crispi Fatima , Gratacós Eduard , Fritsche Ellen
Published: October 2020

The aim of this study was to develop a rabbit neurosphere culture to characterize differences in basic processes of neurogenesis induced by intrauterine growth restriction (IUGR). A novel in vitro neurosphere culture has been established using fresh or frozen neural progenitor cells from newborn (PND0) rabbit brains. After surgical IUGR induction in pregnant rabbits and cesarean section 5 days later, neural progenitor cells from both control and IUGR groups were isolated and directly cultured or frozen at −80°C. These neural progenitor cells spontaneously formed neurospheres after 7 days in culture. The ability of control and IUGR neurospheres to migrate, proliferate, differentiate to neurons, astrocytes, or oligodendrocytes was compared and the possibility to modulate their responses was tested by exposure to several positive and negative controls. Neurospheres obtained from IUGR brains have a significant impairment in oligodendrocyte differentiation, whereas no significant differences are observed in other basic processes of neurogenesis. This impairment can be reverted by in vitro exposure of IUGR neurospheres to thyroid hormone, which is known to play an essential role in white matter maturation in vivo. Our new rabbit neurosphere model and the results of this study open the possibility to test several substances in vitro as neuroprotective candidates against IUGR induced neurodevelopmental damage while decreasing the number of animals and resources and allowing a more mechanistic approach at a cellular functional level.
Nanonickel Oxides Prepared by Atomic Layer Deposition as Efficient Catalyst for the Dehydrogenation of N‐Heterocycles
Authors: Du Liyong , Shi Li , Liu Yunxiao , Ling Yong , Zhang Yanan , Zhou Changjian , Xiong Biao
Published: October 2020

An efficient heterogeneous catalyst nickel oxide supported on graphene nanoplatelets (NiO/Gr) has been developed for the aerobic and additive‐free dehydrogenation of N‐heterocycles. This catalyst was easily prepared by atomic layer deposition from nickel(II) diketonate–diamine and ozone, which has advantages of excellent activity, low metal loading, simple preparation, stability for multiple reuse. The reactions proceed in good yields with broad substrate scope under mild conditions by using tiny quantity of catalyst. Interestingly, pharmaceutically relevant tetrahydro‐β‐carboline derivative can also be oxidized successfully to afford the important intermediate. The control experiments suggest that this catalytic dehydrogenation experiences radical‐type oxidation.
Amyloid Fibril‐Templated High‐Performance Conductive Aerogels with Sensing Properties
Authors: Han Yangyang , Cao Yiping , Bolisetty Sreenath , Tian Tian , Handschin Stephan , Lu Canhui , Mezzenga Raffaele
Published: October 2020

Amyloid fibrils have garnered increasing attention as viable building blocks for functional material design and synthesis, especially those derived from food and agricultural wastes. Here, amyloid fibrils generated from β‐lactoglobulin, a by‐product from cheese industries, have been successfully used as a template for the design of a new class of high‐performance conductive aerogels with sensing properties. These mechanically stable aerogels with three‐dimensional porous architecture have a large surface area (≈159 m2 g−1), low density (≈0.044 g cm−3), and high electrical conductivity (≈0.042 S cm−1). A pressure sensing device is developed from these aerogels based on their combined electrical conductivity and compressible properties. More interestingly, these aerogels can be employed to design novel enzyme sensors by exploiting the proteinaceous nature of amyloid fibrils. This study expands the scope of structured amyloid fibrils as scaffolds for in situ polymerization of conducting polymers, offering new opportunities to design materials with multiple functionalities.
The SU(3) spin model with chemical potential by series expansion techniques
Authors: Kim Jangho , Pham Anh Quang , Philipsen Owe , Scheunert Jonas
Published: October 2020

Abstract

The SU(3) spin model with chemical potential corresponds to a simplified version of QCD with static quarks in the strong coupling regime. It has been studied previously as a testing ground for new methods aiming to overcome the sign problem of lattice QCD. In this work we show that the equation of state and the phase structure of the model can be fully determined to reasonable accuracy by a linked cluster expansion. In particular, we compute the free energy to 14-th order in the nearest neighbour coupling. The resulting predictions for the equation of state and the location of the critical end points agree with numerical determinations to $$ \mathcal{O} $$
O
(1%) and $$ \mathcal{O} $$
O
(10%), respectively. While the accuracy for the critical couplings is still limited at the current series depth, the approach is equally applicable at zero and non-zero imaginary or real chemical potential, as well as to effective QCD Hamiltonians obtained by strong coupling and hopping expansions.