bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrospun protein fibers loaded with yerba mate extract for bioactive release in food packaging
Authors: Pinheiro Bruni Graziella , dos Santos Acunha Tanize , de Oliveira Jean P , Martins Fonseca Laura , Tavares da Silva Francine , Martins Guimarães Vilásia , da Rosa Zavareze Elessandra
Published: March 2020

BACKGROUND

Yerba mate extract was encapsulated in electrospun zein fibers. Solutions were prepared with 30% (w/v) zein, and yerba mate extract was added at concentrations of 1%, 3%, and 5% (w/w). The rheology and electrical conductivity of the polymer solutions were evaluated. The extract and the fibers were characterized through an analysis of total and individual phenolic compounds, antioxidant activity, and Fourier‐transform infrared (FTIR) spectra. Morphology, size distribution, and thermal stability were also evaluated. The release kinetics of zein fibers loaded with different concentrations of yerba mate were evaluated in a hydrophilic food‐simulant medium (10% ethanol).

RESULTS

Yerba mate extract had a total phenolic compound content of 1287.76 ± 11.55 mg of gallic acid 100 g−1 yerba mate extract. The major individual phenolic compounds obtained were chlorogenic acid and rutin, quantified by high‐performance liquid chromatography and mess spectrometry (HPLC–MS). Zein fibers loaded with 5% extract exhibited higher antioxidant activity with 83.0% inhibition. The fibers with different concentrations of yerba mate displayed homogeneous morphology. Yerba mate extract encapsulated in zein fibers had greater thermal stability than the free extract. Zein fibers comprising 5% yerba mate extract, when in contact with a hydrophilic food simulant medium, showed a release of approximately 49% of extract within 50 h.

CONCLUSION

Zein fibers containing yerba mate extract may be used as antioxidant releasers for food packaging. © 2020 Society of Chemical Industry
Positron‐emitting tracer imaging of fluoride transport and distribution in tea plant
Authors: Niu Hui‐liang , Peng Chuan‐yi , Zhu Xu‐dong , Dong Yang‐yang , Li Ye‐yun , Tang Ling‐ling , Wan Xiao‐chun , Cai Hui‐mei
Published: March 2020

BACKGROUND

Tea (Camellia sinensis (L.) O. Kuntze) is a hyper‐accumulator of fluoride (F). To understand F uptake and distribution in living plants, we visually evaluated the real‐time transport of F absorbed by roots and leaves using a positron‐emitting (18F) fluoride tracer and a positron‐emitting tracer imaging system.

RESULTS

F arrived at an aerial plant part about 1.5 h after absorption by roots, suggesting that tea roots had a retention effect on F, and then was transported upward mainly via the xylem and little via the phloem along the tea stem, but no F was observed in the leaves within the initial 8 h. F absorbed via a cut petiole (leaf 4) was mainly transported downward along the stem within the initial 2 h. Although F was first detected in the top and ipsilateral leaves, it was not detected in tea roots by the end of the monitoring. During the monitoring time, F principally accumulated in the node.

CONCLUSION

F uptake by the petiole of excised leaf and root system was realized in different ways. The nodes indicated that they may play pivotal roles in the transport of F in tea plants. © 2020 Society of Chemical Industry
Chromatographic separation simulation of metal‐chelating peptides from surface plasmon resonance binding parameters
Authors: Muhr Laurence , Pontvianne Steve , Selmeczi Katalin , Paris Cédric , Boschi‐Muller Sandrine , Canabady‐Rochelle Laetitia
Published: March 2020

Some metal‐chelating peptides have antioxidant properties, with potential nutrition, health, and cosmetics applications. This study aimed to simulate their separation on immobilized metal ion affinity chromatography from their affinity constant for immobilized metal ion determined in surface plasmon resonance, both technics are based on peptide‐metal ion interactions. In our approach, first, the affinity constant of synthetic peptides was determined by surface plasmon resonance and used as input data to numerically simulate the chromatographic separation with a transport‐dispersive model based on Langmuir adsorption isotherm. Then, chromatographic separation was applied on the same peptides to determine their retention time and compare this experimental tR with the simulated tR obtained from simulation from surface plasmon resonance data. For the investigated peptides, the relative values of tR were comparable. Hence, our study demonstrated the pertinence of such numerical simulation correlating immobilized metal ion affinity chromatography and surface plasmon resonance.
Migratory Flyways May Affect Population Structure in Double‐Crested Cormorants
Authors: Kimble Steven J. A. , Dorr Brian S. , Hanson‐Dorr Katie C. , Rhodes Olin E. , Devault Travis L.
Published: March 2020

Double‐crested cormorants (Phalacrocorax auritus) recovered from a demographic bottleneck so well that they are now considered a nuisance species at breeding and wintering grounds across the United States and Canada. Management of this species could be improved by refining genetic population boundaries and assigning individuals to their natal population. Further, recent radio‐telemetry data suggest the existence of Interior and Atlantic migratory flyways, which could reduce gene flow and result in substantial genetic isolation. In this study, we used 1,784 individuals collected across the eastern United States, a large panel of microsatellite markers developed for this species, and individuals banded as chicks and recaptured as adults to explore the effects of migratory flyways on population structure, quantify the genetic effects of demographic bottlenecks, and determine whether individuals could be assigned to their natal population based on genotype. We found evidence for genetic population division only along migratory flyways, no evidence of genetic bottlenecks, and mixed effectiveness of assignment tests. Our population structure findings suggest that gene flow is high across large scales; for example, individuals from New York, Minnesota, and Alabama are all in panmixia. We also found that traditional subspecies ranges may not be valid because >1 subspecies was present in single genetic populations. The lack of evidence for genetic bottlenecks also likely underscores the vagility of this species, suggesting that even during demographic bottlenecks, populations were not isolated from allelic exchange. Finally, the failure of assignment tests to consistently perform is likely due in part to imperfect a priori sampling of Atlantic and Interior chicks and the high vagility of adults. We conclude that the demographic bottleneck is not likely to have reduced genetic diversity, and that assignment tests remain unreliable for this species. We recommend double‐crested cormorants be managed by flyway. Further development of genomic resources in this species could improve population subdivision resolution, improve assignment tests, and reveal further information on demographic histories. © 2020 The Wildlife Society.
Chinese researchers' perceptions and use of open access journals: Results of an online questionnaire survey
Authors: Xu Jie , He Chen , Su Jing , Zeng Yuanxiang , Wang Zixian , Fang Fei , Tang Wenhui
Published: March 2020

This paper reports the results of a survey on Chinese researchers' perceptions and use of open access journals (OAJs). A total of 381 Chinese researchers from different universities and disciplines were investigated through an online questionnaire survey in August and September 2018. The results showed that most Chinese researchers are familiar with and have positive attitude to OAJs. They know OAJs mainly through their peers, colleagues, and friends. PubMed Central, PLoS, and COAJ (China Open Access Journals) are the most well‐known OAJ websites among Chinese researchers. As for use, most of the respondents read and cite OAJs frequently and have experience of publishing in OAJs. However, they strongly prefer to use OAJs indexed in reputable databases (e.g. Web of Science, WoS) when making publishing decisions. Significant differences can be seen among disciplines, with researchers in HSS areas using OAJs less frequently than researchers from other disciplines, although they have the same positive attitudes and are equally well informed about them. Younger researchers preferred to rely on prestigious institutions and authors when using OAJs.
Modified mean curvature flow of entire locally Lipschitz radial graphs in hyperbolic space
Authors: Allmann Patrick , Lin Longzhi , Zhu Jingyong
Published: March 2020

The Asymptotic Plateau Problem asks for the existence of smooth complete hypersurfaces of constant mean curvature with prescribed asymptotic boundary at infinity in the hyperbolic space . The modified mean curvature flow (MMCF)
was firstly introduced by Xiao and the second author a few years back in [15], and it provides a tool using geometric flow to find such hypersurfaces with constant mean curvature in . Similar to the usual mean curvature flow, the MMCF is the natural negative L2‐gradient flow of the area‐volume functional associated to a hypersurface Σ. In this paper, we prove that the MMCF starting from an entire locally Lipschitz continuous radial graph exists and stays radially graphic for all time. In general one cannot expect the convergence of the flow as it can be seen from the flow starting from a horosphere (whose asymptotic boundary is degenerate to a point).
Laser‐Assisted Nanowetting: Selective Fabrication of Polymer/Gold Nanorod Arrays Using Anodic Aluminum Oxide Templates
Authors: He Hung‐Chieh , Yan Ai‐Ling , Karapala Vamsi Krishna , Wang Shun‐Fa , Shen Ming‐Hui , Lin Yu‐Liang , Chen Yi‐Fan , Sugiyama Teruki , Chen Jiun‐Tai
Published: March 2020

1D polymer nanomaterials have attracted significant interest in recent years because of their unique properties and promising applications in various fields. It is, however, still a challenge to fabricate polymer nanoarrays with desired sizes and controlled morphologies. Here, an unprecedented approach, the laser‐assisted nanowetting (LAN) method, to selectively fabricate polymer nanoarrays is presented. Polystyrene (PS) is blended with gold nanorods (AuNRs), which are used to absorb the energy from the laser. After the blend films are brought in contact with AAO templates, the AuNRs at regions shone by the laser beams absorb the energy and heat the surrounding polymer chains, resulting in the formation of PS/AuNRs arrays in selected areas. This work paves a new research direction for developing template‐based polymer nanomaterials.
A kernel‐based algorithm for the spectral fluence of clinical proton beams to calculate dose‐averaged LET and other dosimetric quantities of interest
Authors: Bertolet A. , Cortés‐Giraldo M. A. , Souris K. , Carabe A.
Published: March 2020

Purpose

To introduce a new analytical methodology to calculate quantities of interest in particle radiotherapy inside the treatment planning system. Models are proposed to calculate dose‐averaged LET (LETd) in proton radiotherapy.

Material and methods

A kernel‐based approach for the spectral fluence of particles is developed by means of analytical functions depending on depth and lateral position. These functions are obtained by fitting them to data calculated with Monte Carlo (MC) simulations using Geant4 in liquid water for energies from 50 to 250 MeV. Contributions of primary, secondary protons and alpha particles are modeled separately. Lateral profiles and spectra are modeled as Gaussian functions to be convolved with the fluence coming from the nozzle. LETd is obtained by integrating the stopping power curves from the PSTAR and ASTAR databases weighted by the spectrum at each position. The fast MC code MCsquare is employed to benchmark the results.

Results

Considering the nine energies simulated, fits for the functions modeling the fluence in‐depth provide an average

equal to 0.998, 0.995 and 0.986 for each one of the particles considered. Fits for the Gaussian lateral functions yield average

of 0.997, 0.982 and 0.993, respectively. Similarly, the Gaussian functions fitted to the computed spectra lead to average

of 0.995, 0.938 and 0.902. LETd calculation in water shows mean differences of −0.007 ± 0.008 keV/μm with respect to MCsquare if only protons are considered and 0.022 ± 0.007 keV/μm including alpha particles. In a prostate case, mean difference for all voxels with dose >5% of prescribed dose is 0.28 ± 0.23 keV/μm.

Conclusion

This new spectral fluence‐based methodology allows for simultaneous calculations of quantities of interest in proton radiotherapy such as dose, LETd or microdosimetric quantities. The method also enables the inclusion of more particles by following an analogous process.
Improved compressed sensing and super‐resolution of cardiac diffusion MRI with structure‐guided total variation
Authors: Teh Irvin , McClymont Darryl , Carruth Eric , Omens Jeffrey , McCulloch Andrew , Schneider Jürgen E.
Published: March 2020

Purpose

Structure‐guided total variation is a recently introduced prior that allows reconstruction of images using knowledge of the location and orientation of edges in a reference image. In this work, we demonstrate the advantages of a variant of structure‐guided total variation known as directional total variation (DTV), over traditional total variation (TV), in the context of compressed‐sensing reconstruction and super‐resolution.

Methods

We compared TV and DTV in retrospectively undersampled ex vivo diffusion tensor imaging and diffusion spectrum imaging data from healthy, sham, and hypertrophic rat hearts.

Results

In compressed sensing at an undersampling factor of 8, the RMS error of mean diffusivity and fractional anisotropy relative to the fully sampled ground truth were 44% and 20% lower in DTV compared with TV. In super‐resolution, these values were 29% and 14%, respectively. Similarly, we observed improvements in helix angle, transverse angle, sheetlet elevation, and sheetlet azimuth. The RMS error of the diffusion kurtosis in the undersampled data relative to the ground truth was uniformly lower (22% on average) with DTV compared to TV.

Conclusion

Acquiring one fully sampled non‐diffusion‐weighted image and 10 diffusion‐weighted images at 8× undersampling would result in an 80% net reduction in data needed. We demonstrate efficacy of the DTV algorithm over TV in reducing data sampling requirements, which can be translated into higher apparent resolution and potentially shorter scan times. This method would be equally applicable in diffusion MRI applications outside the heart.
Non‐negative least squares computation for in vivo myelin mapping using simulated multi‐echo spin‐echo T2 decay data
Authors: Wiggermann V. , Vavasour I.M. , Kolind S.H. , MacKay A.L. , Helms G. , Rauscher A.
Published: March 2020

Multi‐compartment T2 mapping has gained particular relevance for the study of myelin water in the brain. As a facilitator of rapid saltatory axonal signal transmission, myelin is a cornerstone indicator of white matter development and function. Regularized non‐negative least squares fitting of multi‐echo T2 data has been widely employed for the computation of the myelin water fraction (MWF), and the obtained MWF maps have been histopathologically validated. MWF measurements depend upon the quality of the data acquisition, B1+ homogeneity and a range of fitting parameters. In this special issue article, we discuss the relevance of these factors for the accurate computation of multi‐compartment T2 and MWF maps. We generated multi‐echo spin‐echo T2 decay curves following the Carr‐Purcell‐Meiboom‐Gill approach for various myelin concentrations and myelin T2 scenarios by simulating the evolution of the magnetization vector between echoes based on the Bloch equations. We demonstrated that noise and imperfect refocusing flip angles yield systematic underestimations in MWF and intra−/extracellular water geometric mean T2 (gmT2). MWF estimates were more stable than myelin water gmT2 time across different settings of the T2 analysis. We observed that the lower limit of the T2 distribution grid should be slightly shorter than TE1. Both TE1 and the acquisition echo spacing also have to be sufficiently short to capture the rapidly decaying myelin water T2 signal. Among all parameters of interest, the estimated MWF and intra−/extracellular water gmT2 differed by approximately 0.13–4 percentage points and 3–4 ms, respectively, from the true values, with larger deviations observed in the presence of greater B1+ inhomogeneities and at lower signal‐to‐noise ratio. Tailoring acquisition strategies may allow us to better characterize the T2 distribution, including the myelin water, in vivo.
Prescribed Protein Intake Does Not Meet Recommended Intake in Moderate‐ and Late‐Preterm Infants: Contribution to Weight Gain and Head Growth
Authors: Gerritsen Linda , Lindeboom Robert , Hummel Thalia
Published: March 2020

Background

The purpose of the study was to evaluate differences between prescribed and recommended protein intake in moderate‐preterm (MP) and late‐preterm (LP) infants and examine the contribution of the first week's prescribed protein intake to growth until term age.

Methods

Data on intake and anthropometrics were collected retrospectively in 235 preterm infants admitted to our general hospital's neonatal ward: 60 MP (320/7–336/7 weeks’ gestational age) and 175 LP (340/7–366/7 weeks’ gestational age). Differences between prescribed and recommended protein intake during the first postnatal week and z‐score change for weight and head circumference (HC) between birth and term age were calculated. Multiple regression was used to evaluate the independent contribution of first week's prescribed protein intake to growth until term age.

Results

At day 7, 58% of MP and 19% of LP infants reached recommended protein intake. At term age, mean z‐score change was −0.4 for weight and +0.1 for HC. Mean protein intake (g/kg/d) was associated with z‐score change of +0.34 (95% CI, 0.14–0.53; P < .001) for weight and +0.25 (95% CI, 0–0.5; P = .03) for HC. Reaching recommended protein intake at day 7 was only independently associated with weight z‐score change (+0.22 [95% CI, 0.04–0.41; P = .002]).

Conclusion

First week's prescribed protein intake does not meet recommended intake. Higher protein intakes in the first postnatal week result in increased weight gain and head growth until term age. Desirability and feasibility of increasing the protein intake need careful consideration and further discussion.
Rubber magnets based on NBR and lithium ferrite with the ability to absorb electromagnetic radiation
Authors: Kruželák Ján , Kvasničáková Andrea , Ušák Elemír , Ušáková Mariana , Dosoudil Rastislav , Hudec Ivan
Published: March 2020

Rubber magnetic composites were prepared through the incorporation of magnetic soft lithium ferrite into acrylonitrile butadiene rubber. Standard sulfur‐based curing and peroxide curing systems were used for cross‐linking of rubber matrices. The experimental part was focused on the investigation of ferrite content and curing system composition on cross‐link density, physical‐mechanical, magnetic and shielding characteristics of composites. The results demonstrated that cross‐link density and physical‐mechanical properties of composites can be modified by both the amount of ferrite and composition of the curing system. The influence of curing systems on magnetic properties was negligible. It can be stated that the application of lithium ferrite to rubber matrix leads to the preparation of rubber composites with the ability to efficiently absorb harmful electromagnetic radiation in the tested frequency range. The shielding efficiency of composites increased with increasing content of magnetic filler.
Synergistic effect of flame retardants and graphitic carbon nitride on flame retardancy of polylactide composites
Authors: Cao Xianwu , Chi Xiaoning , Deng Xueqin , Liu Tao , Yu Bin , Wang Bin , Yuen Anthony C. Y. , Wu Wei , Li Robert K. Y.
Published: March 2020

In order to improve the flame retardant of polylactide (PLA), the synergistic effect of graphitic carbon nitride (g‐C3N4) with commercial‐available flame retardants melamine pyrophosphate (MPP) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was investigated. The PLA composites containing 5 wt% g‐C3N4 and 10 wt% DOPO had a highest limited oxygen index (LOI) value of 29.5% and reached the V‐0 rating of UL‐94 test. The cone calorimeter tests exhibited that DOPO had a better synergistic effect with g‐C3N4 than MPP to improve flame retardancy of PLA. The peak heat release rate (pHRR) and total heat release (THR) of PLA composites containing 10 wt% DOPO could be reduced by 25.2% and 23.6%, respectively, as compared with those of pure PLA. The presence of rich phosphorus element and aromatic groups in DOPO contributed to obtain continuous compact char layer and increase the graphitization level of char residues, thereby, resulting in improving the flame retardancy of PLA together with g‐C3N4. In addition, the incorporation of DOPO can serve as a plasticizer to reduce the complex viscosity, improving the processability of PLA composites.
CDK9 is dispensable for YAP‐driven hepatoblastoma development
Authors: Chen Xinyan , Kiss Andras , Schaff Zsuzsa , Evert Katja , Zhang Yi , Zhong Sheng , Wang Jingxiao , Evert Matthias , Calvisi Diego F. , Chen Xin
Published: March 2020

Background

Hepatoblastoma (HB) is the most common pediatric liver malignancy, occurring mainly during the first 4 years of life. Recent studies unraveled the frequent, coordinated activation of Wnt/β‐catenin and YAP/Hippo (where YAP is yes‐associated protein) pathways in human HB samples. Furthermore, it was found that concomitant overexpression of activated forms of β‐catenin and YAP in the mouse liver triggers HB formation in YAP/β‐catenin mice. Cyclin‐dependent kinases 9 (CDK9) is an elongating kinase, which has been shown to mediate YAP‐driven tumorigenesis. The role of CDK9 in HB molecular pathogenesis has not been investigated to date.

Methods

CDK9 expression was determined in human HB lesions, HB cell lines, and YAP/β‐catenin mouse livers. CDK9 was silenced in human HB cell lines and the effects on growth rate and YAP targets were analyzed. Hydrodynamic transfection of YAPS127A and ∆N90‐β‐catenin together with either shCdk9 or control shLuc (where Luc is luciferase) plasmids was employed to assess the requirement of Cdk9 for HB development in vivo.

Results

Nuclear immunoreactivity for CDK9 protein was more pronounced in human HB samples and YAP/β‐catenin mouse HB tumor tissues than in corresponding surrounding nontumorous liver tissues. CDK9 protein was also expressed in human HB cell lines. Silencing of CDK9 in human HB cell lines did not lead to consistent effects on HB cell growth or YAP target gene expression. Surprisingly, silencing of Cdk9 led to accelerated liver tumorigenesis in YAP/β‐catenin mice.

Conclusion

CDK9 is not a major downstream mediator of YAP oncogenic function in HB development and progression.
Do children and adolescents with completely resected alveolar rhabdomyosarcoma require adjuvant radiation? A report from the Children's Oncology Group
Authors: Aye Jamie M. , Chi Yueh‐Yun , Tian Jing , Rudzinski Erin R. , Binitie Odion T. , Dasgupta Roshni , Wolden Suzanne L. , Hawkins Douglas S. , Gupta Abha A.
Published: March 2020

Background

The role of adjuvant radiotherapy (RT) remains unclear in patients with localized, completely resected (group I) alveolar rhabdomyosarcoma (ARMS).

Procedure

Patients with group I ARMS enrolled on any one of three prior Children's Oncology Group (COG) clinical trials (D9602, D9803, or ARST0531) were analyzed. All patients received systemic chemotherapy and 36 Gy adjuvant RT (if given) to the primary site at week 12 or week 4 for D9602/D9803 and ARST0531, respectively.

Results

Thirty‐six patients with group I ARMS were treated on D9602 (n = 6), D9803 (n = 17), or ARST0531 (n = 13), of whom 24 (67%) were male. The median age was 4.1 years (range, 0.8‐45.8). Twenty (56%) patients had an unfavorable primary site, and 10 (28%) had tumors > 5 cm. FOXO1‐fusion status was negative, positive, and unknown in 10 (28%), 15 (42%), and 11 (30%) tumors, respectively. Twenty‐two (61%) patients received RT. Overall, the four‐year event‐free survival (EFS) and overall survival (OS) were 70.8% and 88.3%, respectively. Patients with FOXO1 positivity who received RT had superior EFS compared with those who did not (77.8% vs 16.7%; P = 0.03). Among 10 patients who were FOXO1 negative, the outcome was similar with or without RT.

Conclusions

Although limited by a small sample size, data from this study support the routine use of adjuvant RT in patients with FOXO1‐positive disease even after complete resection. Additionally, omitting adjuvant RT is rational for patients with FOXO1‐negative ARMS and will be prospectively investigated in the current COG trial ARST1431.
Discordant fetal sex on NIPT and ultrasound
Authors: Smet Maria‐Elisabeth , Scott Fergus P. , McLennan Andrew C.
Published: March 2020

Prenatal diagnosis of sex discordance is a relatively new phenomenon. Prior to cell‐free DNA testing, the diagnosis of a disorder of sexual differentiation was serendipitous, either through identification of ambiguous genitalia at the midtrimester morphology ultrasound or discovery of genotype‐phenotype discordance in cases where preimplantation genetic diagnosis or invasive prenatal testing had occurred. The widespread integration of cfDNA testing into modern antenatal screening has made sex chromosome assessment possible from 10 weeks of gestation, and discordant fetal sex is now more commonly diagnosed prenatally, with a prevalence of approximately 1 in 1500‐2000 pregnancies. Early detection of phenotype‐genotype sex discordance is important as it may indicate an underlying genetic, chromosomal or biochemical condition and it also allows for time‐critical postnatal treatment. The aim of this article is to review cfDNA and ultrasound diagnosis of fetal sex, identify possible causes of phenotype‐genotype discordance and provide a systematic approach for clinicians when counseling and managing couples in this circumstance.
Creatinine recognition using designed synthetic receptors
Authors: Jana Subrata , Prajapati Sunita , Suryavanshi Kishor Kumar , Goswami Shyamaprosad , Parida Rakesh , Giri Santanab
Published: March 2020

A series of neutral nonenzymatic receptors have been synthesized for the recognition of creatinine in a nondegrative way. The receptors contain different heterocyclic moieties for better interactions between host and guest. Among these, 1, 4, and 5 are fluorescent receptors for creatinine. From this study, it was found that the receptors 1 and 4 containing the naphthyridine moiety have higher binding affinity to the guest creatinine than receptors containing other heterocyclic moiety. Theoretical studies for the calculation of binding energy were carried out using discrete Fourier transform (DFT) for the hosts and their complexation with creatinine in both gas phase and acetonitrile medium.
Radiobiological Implications of Nanoparticles Following Radiation Treatment
Authors: Ahmad Reem , Schettino Giuseppe , Royle Gary , Barry Miriam , Pankhurst Quentin A. , Tillement Olivier , Russell Ben , Ricketts Kate
Published: March 2020

Materials with a high atomic number (Z) are shown to cause an increase in the level of cell kill by ionizing radiation when introduced into tumor cells. This study uses in vitro experiments to investigate the differences in radiosensitization between two cell lines (MCF‐7 and U87) and three commercially available nanoparticles (gold, gadolinium, and iron oxide) irradiated by 6 MV X‐rays. To assess cell survival, clonogenic assays are carried out for all variables considered, with a concentration of 0.5 mg mL−1 for each nanoparticle material used. This study demonstrates differences in cell survival between nanoparticles and cell line. U87 shows the greatest enhancement with gadolinium nanoparticles (2.02 ± 0.36), whereas MCF‐7 cells have higher enhancement with gold nanoparticles (1.74 ± 0.08). Mass spectrometry, however, shows highest elemental uptake with iron oxide and U87 cells with 4.95 ± 0.82 pg of iron oxide per cell. A complex relationship between cellular elemental uptake is demonstrated, highlighting an inverse correlation with the enhancement, but a positive relation with DNA damage when comparing the same nanoparticle between the two cell lines.
Monodispersed β‐Glycerophosphate‐Decorated Bioactive Glass Nanoparticles Reinforce Osteogenic Differentiation of Adipose Stem Cells and Bone Regeneration In Vivo
Authors: Guo Yi , Xue Yumeng , Ge Juan , Lei Bo
Published: March 2020

Design and development of highly bioactive nanoscale biomaterials with enhanced osteogenic differentiation on adipose stem cells is rather important for bone regeneration and attracting much attention. Herein, monodispersed glycerophosphate‐decorated bioactive glass nanoparticles (BGN@GP) are designed and their effect is investigated on the osteogenic differentiation of adipose mesenchymal stem cells (ADMSCs) and in vivo bone regeneration. The surface‐modified BGN@GP can be efficiently taken by ADMSCs and shows negligible cytotoxicity. The in vitro results reveal that BGN@GP significantly enhances the alkaline phosphatase activity and calcium biominerialization of ADMSCs either under normal or osteoinductive medium as compared to BGNs. Further studies find that the osteogenic genes and proteins including Runx2 and Bsp in ADMSCs are significantly improved by BGN@GP even under normal culture medium. The in vivo animal experiment confirms that BGN@GP significantly promotes the new bone formation in a rat skull defect model. This study suggests that bioactive small molecule decorating is an efficient strategy to improve the osteogenesis capacity of inorganic ceramics nanomaterials.
Defect Generation Mechanism of Epitaxially Grown In Situ Phosphorus‐Doped Silicon on Silicon (111) Substrate
Authors: Lee Juhee , Ko Eunjung , Shin Hyunsu , Ko Dae-hong
Published: March 2020

There are many studies regarding improving the quality of in situ phosphorus‐doped (ISPD) epitaxial silicon films as a source and drain material to achieve low specific contact resistivity. The top surfaces of these films, contact interface, in 3D structure devices such as Fin field‐effect transistor and gate‐all‐around field‐effect transistor are grown from diamond‐shaped source and drain with four edges of the (111) surfaces. Therefore, the physical properties of these sources and drains in a 3D structure device are strongly related to those of ISPD silicon grown on the (111) substrate. Here, ISPD silicon is grown using reduced pressure chemical vapor deposition on a silicon (111) substrate at 700 °C, and this film is analyzed using high‐resolution transmission electron microscopy, atom probe tomography, and energy‐dispersive X‐ray spectroscopy (EDX). The results show that this film exhibits many defects such as twin or stacking fault, and phosphorus exhibits cluster distribution. To confirm the relationship between phosphorus and defect generation, an atomic resolution EDX mapping of phosphorus atoms is used, and the position of the observed defects corresponds with the clustered phosphorus in a mapping image.
State‐dependent switching law design with guaranteed dwell time for switched nonlinear systems
Authors: Liu Qian , Long Lijun
Published: March 2020

In this article, without the help of predesigned dwell time constraints, a new state‐dependent switching law with guaranteed dwell time for switched nonlinear systems is studied. Some sufficient conditions for asymptotic stability of switched nonlinear systems are derived. Also, all the abovementioned conditions can be transformed to a set of sum of squares (SOS) constraints, which can be checked by using the bilinear SOS methodology. Meanwhile, an improved path following method is provided to solve a bilinear SOS problem. Finally, three simulation examples are given to demonstrate the effectiveness of the obtained results.
The way to sustainable development through income equality: The impact of trade liberalisation and financial development
Authors: Gharleghi Behrooz , Jahanshahi Asghar Afshar
Published: March 2020

The main aim of this paper is to examine the threshold impact of financial development and trade liberalization on income inequality as a measure of sustainable development in a sample of developed and developing countries using panel threshold analysis. Two major dimensions of financial development are considered: liquid liabilities and stock market capitalization. The empirical results revealed that financial development reduces income inequality only in countries where their GDP per capita is above ~US$11,000. It has no significant impact in reducing inequality in developing countries. This implies that institutional reforms in less developed and developing countries are necessary in order to reap the gains from financial development. Trade liberalization is found to have a positive impact on income inequality for both country groups—that is, trade benefits have worsened the income distribution.
Large‐scale quantification of aluminum in AlxGa1‐xN alloys by ToF‐SIMS: The benefit of secondary cluster ions
Authors: Huang Rong , Chen Xiao , Li Fangsen , Ding Sunan , Yang Hui
Published: March 2020

Precise determination of composition is requisite for AlxGa1‐xN‐based energy band engineering. Secondary cluster ions in a time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) full spectrum are introduced for accurate quantification of Al in AlxGa1‐xN for AlGaN‐based devices. It was found that statistical analysis with huge number of large secondary cluster ions (without small ions) show much better linear dependence with apparent compensation of matrix effect, particularly in negative polarity. For AlxGa1‐xN with x = 0 to 0.7, x values calculated based on large negative cluster ions (NCIs) show excellent linear dependence with real values. Besides, atomic count ratio of C (Al)/C (Ga) and C (Ga)/C (Al) also shows great linear relationships with corresponding mole fraction ratios in a large range. Overlap of these linear ranges offers a reliable and convenient quantification protocol of AlxGa1‐xN covering a full range of x = 0 to 1. This study verifies that the secondary cluster ions are beneficial for quantification of AlxGa1‐xN‐based materials.
Preparation and In Vitro Biological Evaluation of Lawsone Loaded O‐Carboxymethyl Chitosan/Zinc Oxide Nanocomposite for Wound‐Healing Application
Authors: Sakthiguru Nagarajan , Sithique Mohamed Aboobucker
Published: March 2020

A biopolymer based nanocomposite with O‐Carboxymethyl chitosan (O‐Cmc), nano zinc oxide (ZnO) and Lawsone (Ln) with proving advantages in antibacterial wound healing application was prepared. The physiochemical characteristics of the nanocomposite (NCs) was analysed by Fourier Transmission Infrared spectroscopy (FT‐IR), X‐Ray Diffractometer (XRD), Scanning electron Microscopy (SEM), Transmission electron microscope (TEM) and Thermogravimetric analysis (TGA). The biological properties such as anti‐inflammatory, anti‐oxidant activities were investigated in vitro. The nanocomposite also possesses efficient drug encapsulation and releasing profile with greater stability in phosphate buffer saline (PBS) and Dulbecco's minimal essential medium (DMEM). The results of the antibacterial studies show its enhanced bactericidal nature. The results obtained from MTT assay, Ethidium bromide stained fluorescence image and in vitro wound scratch assay show greater cell viability with the closure of scratch wound obviously proves it′s prominent biocompatible, wound closure nature. These biological properties show that the prepared nanocomposite has a greater potential to act as an excellent biomaterial in the field of wound care applications.
Solvent‐Free Synthesis and In Vitro Antitumor Activity of a New Class of (Z)‐3‐Arylidene‐1H‐pyrano[3,4‐b]quinolin‐4(3H)‐ones
Authors: Li Yang , Tang Bingyue , Dong Shiyu , Gao Wentao , Jiang Wenting , Chen Yu
Published: March 2020

In the present investigation, an efficient and green synthesis of an intriguing array of structurally novel quinoline‐based α‐arylidene cycloketones i. e., (Z)‐3‐arylidene/ferrocenylmethylene‐5‐methyl/phenyl‐1H‐pyrano[3,4‐b]quinolin‐4(3H)‐ones (6 a‐z, 6 aa and 6 ab) has been successfully accomplished involving solvent‐free reaction between pyrano[3,4‐b]quinolin‐4(3H)‐ones (7 a‐b) and various aromatic aldehydes by simple hand‐grinding in a mortar and pestle using KOH as base at room temperature. The synthetic strategy has the attractive features such as experimental simplicity, mild and environmentally benign reaction conditions, easy work‐up procedure and good yields. A primary screening for their in vitro inhibitory activities against cancer cell lines A549, HT29 and T‐24 revealed that compounds 6 g and 6 t containing 3,4,5‐trimethoxyphenyl moiety showed promising antitumor activity against A549 (IC50 = 3.68 ± 0.69 and 4.82 ± 0.19 μmol•mL−1) and HT29 (IC50 = 6.69 ± 1.16 and 7.69 ± 0.64 μmol•mL−1.
Synthesis and Antibacterial Activity of New N‐Substituted Hexahydroquinolinone Derivatives and X‐Ray Crystallographic Studies
Authors: Vinoth Nangagoundan , Kalaiarasi Chinnasamy , Kumaradhas Poomani , Vadivel Pullar , Lalitha Appaswami
Published: March 2020

A novel series of 2‐amino‐4‐aryl‐7,7‐dimethyl‐5‐oxo‐1‐(phenylamino)‐1,4,5,6,7,8‐hexahydroquinoline‐3‐carbonitrile derivatives has been designed using aryl aldehydes, 5,5‐dimethyl‐3‐(2‐phenylhydrazinyl)cyclohex‐2‐enone (phenylhydrazone of dimedone) and malononitrile with piperidine at room temperature. The structures of the synthesized compounds have been well elucidated by various spectroscopic techniques and X‐ray crystal diffraction studies. Selected compounds have also been evaluated for their antibacterial activities against human pathogenic bacteria.
Highly Efficient Solar‐Catalytic Degradation of Reactive Black 5 Dye Using Mesoporous Plasmonic Ag/g‐C3N4 Nanocomposites
Authors: Asadi Fatemeh , Goharshadi Elaheh K. , Sadeghinia Mohammad
Published: March 2020

An azo dye, Reactive Black 5 (RB5), was degraded by three photocatalysts of g‐C3N4, Ag(2 %)/g‐C3N4, and Ag(5 %)/g‐C3N4 with the specific surface areas of 34.41, 28.70, and 35.58 m2 g−1 and the band gaps of 2.52, 1.56, and 1.71 eV under sunlight illumination, respectively. The results showed 40 mg/L of g‐C3N4 could degrade completely 10 ppm RB5 at pH 3.4 within 10 min under sunlight irradiation with the first‐order rate constant of 0.312 min−1. Under the same conditions, the complete degradation time of RB5 reduced to 5 and 7 min when the plasmonic nanocomposites of Ag (2 %)/g‐C3N4 and Ag (5 %)/g‐C3N4 were used as photocatalysts, respectively. Ag content had an important influence on the photocatalytic activity of g‐C3N4 against RB5 so that Ag (2 %)/g‐C3N4 possessed the best photocatalytic efficiency with the rate constant of 0.795 min−1. In fact, Ag nanoparticles through the surface plasmon resonance effects and by accepting the photogenerated electrons could improve the visible‐light absorption and increase charge separation of g‐C3N4. The results showed superoxide radical is the main oxidant in the photodegradation of RB5.
A Novel Strategy for Sustainable Synthesis of Soluble‐Graphene by a Herb Delphinium denudatum Root Extract for Use as Light‐Weight Supercapacitors
Authors: Manchala Saikumar , Tandava VSRK , Jampaiah Deshetti , Bhargava Suresh K. , Shanker Vishnu
Published: March 2020

Synthesis of high‐quality graphene nanosheets under eco‐friendly strategies is of enormous interest today hence graphene‐based materials offer unique advantages in a wide range of applications including light‐weight supercapacitors. The reduction of graphene oxide (GO) by chemical reagents frequently involves hazardous reductants that are also dangerous to humans. In view of sustainability, we develop a facile and green procedure to synthesize soluble‐graphene by reducing the GO in delphinium root extraction for the first time. The reducing property of organic compounds that exist in the aqueous delphinium root extract may be accountable for the reduction of exfoliated GO to D‐graphene under reflux condition. The efficient elimination of oxygen functionalities from GO was verified by powder X‐ray diffraction (PXRD), UV‐Visible spectroscopy (UV‐Vis), Fourier transform infrared (FT‐IR), and X‐ray photoelectron spectroscopy (XPS) studies. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) studies indicate the successful development of few‐layer graphene. The electrochemical activities are delivered by cyclic voltammetry (CV) and galvanic charge‐discharge (GCD) studies. This uniquely‐synthesized D‐graphene electrode offers superior electrochemical performance at 2 A g−1 with an utmost specific capacitance (Cs) of 158 F g−1 and high energy density (E) of 22 Wh Kg−1. Taking the above remarkable results, the characteristics of eco‐friendly, easy synthesis and cheap endow this green approach as a promising avenue for the exploitation of graphene‐based materials in numerous applications, particularly for graphene‐based light‐weight supercapacitors.
Effective Carbon Composite Electrode for Low‐Cost Perovskite Solar Cell with Inorganic CuIn0.75Ga0.25S2 Hole Transport Material
Authors: Behrouznejad Fatemeh , Forouzandeh Mozhdeh , Khosroshahi Rouhollah , Meraji Kazem , Badrabadi Moosa Nakhaee , Dehghani Mehdi , Li Xiaoguo , Zhan Yiqiang , Liao Yuan , Ning Zhijun , Taghavinia Nima
Published: March 2020

Perovskite solar cells are well known for being low cost, solution‐based, and efficient solar cells; however, the high price of the conventional hole‐collector electrode (Spiro‐OMeTAD/Gold) and the high price and complexity of depositing gold on large scales are major barriers against commercializing them. Herein, an effective carbon composite electrode is introduced for a low‐cost perovskite solar cell with CuIn0.75Ga0.25S2 hole transport material to solve this problem. The carbon electrode is deposited by the doctor blade method using a paste composed of flakes of graphite, carbon black, and a kind of hydrophobic polymer (polystyrene or poly‐methyl methacrylate). It is investigated how the weight ratio of carbon black to graphite and type of binder affect sheet resistance and resistivity of carbon composite layer. The effects of carbon electrode composition on the charge transport resistance at the CuIn0.75Ga0.25S2/perovskite interface are investigated using impedance spectroscopy in different light intensities of white light and light with different wavelengths of 530, 660, and 740 nm. The best efficiency of 15.9% is obtained for the champion cell (fabricated outside the glovebox), which is close to the best efficiency of the reference cell with conventional Spiro‐OMeTAD/Gold hole‐collector that is 16.3%.
Effects of Long‐Term Ageing at High Temperatures on Oxide Scale Development and Evolution of Austenitic Steels Microstructure
Authors: Zieliński Adam , Dudziak Tomasz Pawel , Golański Grzegorz , Gazdowicz Jarosław , Kołodziej Anna
Published: March 2020

This study is conducted to investigate the effects of long‐term air oxidation on the microstructural stability of HR3C, HR6W, and Sanicro 25 stainless steel. The materials are exposed to air atmosphere for 1000 and 10 000 h at 650, 700, and 750 °C respectively. The postexposed materials indicate some microstructural changes: the HR3C stainless steel develops Fe–Cr‐rich oxide scale, whereas HR6W steel forms a brittle, low adherent oxide scale consisting different concentrations of Cr, Mn, Fe, and Ni. Finally, Sanicro 25 stainless steel promotes the formation of a homogeneous‐rich Cr oxide scale at high temperatures. The analyses are performed using scanning electron microscopy (SEM)/energy‐dispersive X‐ray spectrometry (EDS) and X‐ray mappings.
An investigation of key mechanical and durability properties of coconut shell concrete with partial replacement of fly ash
Authors: Prakash Ramaiah , Thenmozhi Rajagopal , Raman Sudharshan N. , Subramanian Chidambaram , Divyah Nagarajan
Published: March 2020

This study investigated the effect of adding fly ash on the mechanical and durability characteristics of coconut shell (CS) concrete. Two different mixes were developed, one with CS and the other with conventional aggregate and CS as coarse aggregate. Cement was replaced with Class F fly ash in terms of weight at 0, 10, 20, and 30% in both mixes. Test result showed that the CS concrete with 10% fly ash replacement level exhibited the highest compressive and tensile strength. The addition of fly ash decreased the porosity of CS concrete due to its fineness and increased hydration products in the matrix at later ages. Additionally, it also improved the weak aggregate interfacial transition zone of CS lightweight concrete. Thus, the fly ash addition in CS concrete showed lower values of water absorption, permeable voids, sorptivity, and chloride permeability. Furthermore, the increasing content of fly ash addition improved the durability characteristics of CS concrete considerably.
Partial replacement of cement by ground granulated blast furnace slag and silica fume in two‐stage concrete (preplaced aggregate concrete)
Authors: Das Kunal K. , Lam Eddie S. S. , Tang Ho H.
Published: March 2020

An experimental investigation was carried out to enhance the properties of two‐stage concrete, also known as preplaced aggregate concrete (PAC), by adding ground granulated blast furnace slag (GGBS) and silica fume (SF) as partial replacement of cement at different proportions. PAC was produced using the gravity process by first placing the coarse aggregates into the formwork and then injecting a grout to fill in the voids in‐between the aggregates. Partial replacement of cement by GGBS and SF at 30 and 10%, respectively were found to be a suitable mix for PAC. Even though incorporation of GGBS and SF increased the shrinkage, strength and durability were improved. Generally, shrinkage produced by PAC was significantly lower than that of conventional concrete. By applying preplaced aggregate with an improved composition of grouts, properties of concrete, like strength and permeability, can be enhanced with shrinkage kept within an acceptable level.
Experimental study on wind load characteristics of high‐rise buildings with opening
Authors: Li Yong‐Gui , Zhang Ming‐Yue , Li Yi , Li Qiu‐Sheng , Liu Si‐Jia
Published: March 2020

For investigation of the wind load characteristics on high‐rise buildings with opening, a series of rigid rectangular high‐rise building models with opening were tested by synchronous multi‐pressure sensing system (SMPSS) in a boundary wind tunnel. Influence parameters including different opening heights, opening rates, opening patterns, and terrain categories are studied in detail. Based on the test results, the local wind force coefficients, base moment coefficients, and power spectral densities were discussed. The results indicated that the opening could affect the wind loads acting on high‐rise buildings to different extent. The distinct reduction of wind loads on high‐rise buildings was found at along‐wind direction, which could be evaluated by a proposed simplified expression accordingly. This study aims to provide useful information for the wind‐resistant design of high‐rise buildings with opening.