bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of sema4D in vasculogenic mimicry formation in non‐small cell lung cancer and the underlying mechanisms
Authors: Xia Yun , Cai Xian‐Yi , Fan Ji‐Quan , Zhang Li‐Ling , Ren Jing‐Hua , Li Zhen‐Yu , Zhang Rui‐Guang , Zhu Fang , Wu Gang
Published: October 2018

Vasculogenic mimicry (VM) is a special vascular pattern in malignant tumors, which is composed of highly aggressive tumor cells. This tumor cell‐mediated blood supply pattern is closely associated with a poor prognosis in cancer patients. The interaction of axon guidance factor Sema4D and its high affinity receptor plexinB1 could activate small GTPase RhoA and its downstream ROCKs; this process has an active role in the migration of endothelial cells and tumor angiogenesis. Here, we have begun to uncover the role of this pathway in VM formation in non‐small cell lung cancer (NSCLC). First, we confirmed this special form of vasculature in NSCLC tissues and found the existence of VM channels in tumor tissues was correlated with Sema4D expression. Further, we found that inhibition of Sema4D in the human NSCLC cells H1299 and HCC827 reduces VM formation both in vitro and in vivo. Moreover, we demonstrated that downregulating the expression of plexinB1 by siRNA expressing vectors and inhibiting the RhoA/ROCK signaling pathway using fasudil can reduce VM formation of H1299 and HCC827 cells. Finally, we found that suppression of Sema4D leads to less stress fibers and depleted the motility of H1299 and HCC827 cells. Collectively, our study implicates Sema4D plays an important role in the process of VM formation in NSCLC through activating the RhoA/ROCK pathway and regulating tumor cell plasticity and migration. Modulation of the Sema4D/plexinB1 and downstream RhoA/ROCK pathway may prevent the tumor blood supply through the VM pattern, which may eventually halt growth and metastasis of NSCLC.
A Theoretical Schema for Building Weavings of Nets via Colored Tilings of Two‐Dimensional Spaces and Some Simple Polyhedral, Planar and Three‐Periodic Examples
Authors: Thompson Benjamin , Hyde Stephen T.
Published: October 2018

We analyse two‐component “weavings” made of a pair of dual (p,q) and (q,p) nets that undulate on both sides of the sphere, the plane and the hyperbolic plane. Families of weavings are described, sharing a common parent net. The examples describe zero‐, two‐ and three‐periodic weavings in three‐space. We derive all edge‐2‐transitive weavings with (p,q)=(3,3), (4,3), (4,4), (4,6) using Delaney‐Dress tiling theory, described in detail. The two‐dimensional hyperbolic weaving are mapped into (euclidean) three‐space to form a pair of catenated crystalline nets. The examples suggest generalisations to other weavings on surfaces, including weavings of filaments. A simple hyperbolic weaving of filaments is derived, analogous to the common warp‐and‐weft filament weaving in the plane. The resulting three‐periodic pattern is related to the molecular‐scale weaving in the synthetic COF‐505 material synthesized by Liu et al. [Science, vol. 351: 365–369, 2016].
Reaction mechanism of NO with hydrolysates of NAMI‐A: an MD simulation by combining the QM/MM(ABEEM) with the MD‐FEP method
Authors: Li Hui , Wang Di , Zhao Xin , Lu Li‐Nan , Liu Cui , Gong Li‐Dong , Zhao Dong‐Xia , Yang Zhong‐Zhi
Published: October 2018

Nitrosylation reaction mechanisms of the hydrolysates of NAMI‐A and hydrolysis reactions of ruthenium nitrosyl complexes were investigated in the triplet state and the singlet state. Activation free energies were calculated by combining the QM/MM(ABEEM) method with free energy perturbation theory, and the explicit solvent environment was simulated by an ABEEMσπ polarizable force field. Our results demonstrate that nitrosylation reactions of the hydrolysates of NAMI‐A occur in both the triplet and the singlet states. The Ru‐N‐O angle of the triplet ruthenium nitrosyl complexes is in the range of 132.0°–138.2°. However, all the ruthenium nitrosyl complexes at the singlet state show an almost linear Ru‐N‐O angle. The nitrosylation reaction happens prior to the hydrolysis reaction for the first‐step hydrolysates. The activation free energies of the nitrosylation reactions show that the H2O‐NO exchange reaction of [RuCl4(Im)(H2O)] in the singlet spin sate is the most likely one. Comparing with the activation free energies of the hydrolysis reactions of the ruthenium nitrosyl complexes, the results indicate that the rate of the DMSO–H2O exchange reaction of [RuCl3(NO)(Im)(DMSO)] is faster than that of [RuCl3(H2O)(Im)(DMSO)] in both the triplet spin state and the singlet spin state. © 2018 Wiley Periodicals, Inc.
Leiomyoma of the Retzius space in a male patient: A case report and a diagnostic approach to Retzius space diseases
Authors: Psichogios Christos I. , Chatziioannou Achilles N. , Klapa Ioanna H. , Psichogios Dimitris I. , Antoniou Aristides G.
Published: October 2018

Retzius space is a small anatomical compartment located directly posterior to the pubic symphysis and anterior to the urinary bladder. Diseases developing primarily in this space are rare; only 7 cases of leiomyomas of the Retzius space have been reported in the literature so far, all of them in female patients. We present a unique case of a leiomyoma of the Retzius space in a male patient. An imaging‐based diagnostic approach to Retzius space disease is proposed.
Synthesis and characterization of 11C‐labeled benzyl amidine derivatives as PET radioligands for GluN2B subunit of the NMDA receptors
Authors: Fuchigami Takeshi , Fujimoto Noriko , Haradahira Terushi , Nojiri Yumiko , Okauchi Takashi , Maeda Jun , Suhara Tetsuya , Yamamoto Fumihiko , Nakayama Morio , Maeda Minoru , Mukai Takahiro
Published: October 2018

GluN2B‐containing NMDA receptors (NMDARs) play fundamental roles in learning and memory, although they are also associated with various brain disorders. In this study, we synthesized and evaluated three 11C‐labeled N‐benzyl amidine derivatives 2‐[11C]methoxybenzyl) cinnamamidine ([11C]CBA), N‐(2‐[11C]methoxybenzyl)‐2‐naphthamidine ([11C]NBA), and N‐(2‐[11C]methoxybenzyl)quinoline‐3‐carboxamidine ([11C]QBA) as PET radioligands for these receptors. The 11C‐benzyl amidines were synthesized via conventional methylation of corresponding des‐methyl precursors with [11C]CH3I. In vitro binding characteristics were examined in brain sagittal sections using various GluN2B modulators and off‐target ligands. Further, in vivo brain distribution studies were performed in normal mice. The 11C‐labeled benzyl amidines showed high‐specific binding to the GluN2B subunit at in vitro. In particular, the quinoline derivative [11C]QBA had the best binding properties in terms of high‐brain localization to GluN2B‐rich regions and specificity to the GluN2B subunit. Conversely, these 11C‐radioligands showed the brain distributions were inconsistent with GluN2B expression in biodistribution experiments. The majority of the radiolabeled compounds were identified as metabolized forms of which amido derivatives seemed to be the major species. Although these 11C‐ligands had high‐specific binding to the GluN2B subunit, significant improvement in metabolic stability is necessary for successful positron emission tomography (PET) imaging of the GluN2B subunit of NMDARs.
Soil nitrous oxide emissions from grassland: Potential inhibitor effect of hippuric acid
Authors: Ciganda Verónica S. , López-Aizpún María , Repullo Miguel A. , Wu Di , Terra José A. , Elustondo David , Clough Tim , Cardenas Laura M.
Published: October 2018

In grassland systems, cattle and sheep urine patches are recognized as nitrous oxide (N2O) emission hot spots due to the high urinary nitrogen (N) concentrations. Hippuric acid (HA) is one of the constituents of ruminant urine that has been reported as a natural inhibitor of soil N2O emissions. The aim of this study was to examine the potential for elevated ruminant urine HA concentrations to reduce N2O emissions, in situ, on an acidic heavy clay soil under poorly drained conditions (WFPS > 85%). A randomized complete block design experiment with three replications and four treatments was conducted using the closed‐static‐flux chamber methodology. The four treatments were applied inside the chambers: control with no artificial urine application (C), control artificial urine (U), and enriched artificial urine with two rates of HA (55.8 and 90 mM, U+HA1, U+HA2). Soil inorganic‐N, soil dissolved organic carbon (DOC), soil pH as well as N2O and methane (CH4) fluxes were monitored over a 79‐d period. Although N2O emissions were not affected by the HA enriched urine treatments, U+HA2 positively affected the retention of N as
until day 3, when the soil pH dropped to values < 5. Subsequently, as a consequence of rainfall events and soil acidification, it is likely that leaching or sorption onto clay reduced the efficacy of HA, masking any treatment differential effect on N2O emissions. Moreover, CH4 fluxes as well as DOC results reflected the soil anaerobic conditions which did not favour nitrification processes. Further research is needed to determine the fate of HA into the soil which might clarify the lack of an in situ effect of this compound.
Automatic Raman spectroscopic urine crystal identification system using fluorescent image‐guided 2D scanning platform with Fe3O4crystal violet nanoclusters
Authors: Lo Pei‐An , Huang Yi‐Hsiu , Chiu Yi‐Chun , Huang Li‐Ci , Bai Jia‐Lun , Wu Shu‐Han , Huang Chih‐Chia , Chiang Huihua Kenny
Published: October 2018

Urolithiasis is a common urological disease with a very high recurrence rate, within 5 years. Urine stones are formed by urine crystals. Although the relationship between the composition of the urine stone and the type of urine crystal has been recognized, the efficient collection and accurate identification of the type of urine crystal in clinics remains a challenge. In this study, we develop an automatic Raman spectroscopic urine crystal collection and identification system. Custom‐developed Fe3O4crystal violet nanoclusters are used for (a) separating the urine crystals from the urine samples by a custom‐developed urine processing system and for (b) fluorescent labeling, image guiding, and the Raman spectroscopic measurement of the urine crystals on a 2D scanning stage. The control of the system and the Raman spectroscopic analysis are developed in a LabVIEW environment. This system is a fast and convenient method for the efficient collection and analysis of urinary crystals from urine samples, within 9 min. This automatic urine crystal identification system can enable the early prediction of the types of urine stones and the diet management for urolithiasis patients.
Hairy polyps: A new case presentation and a pathogenetic hypothesis
Authors: Simmonds Jonathan C. , Jabbour Jad , Vaughn Jennifer A. , Paulson Vera A. , Poe Dennis S. , Rahbar Reza
Published: October 2018

Hairy polyps are benign lesions found in the oropharynx or nasopharynx that are thought to be present at birth and can lead to upper airway obstruction in infants. Also known as naso‐oropharyngeal choristoma, they are increasingly viewed as aggregates of bigeminal tissue, likely from the first or second branchial arches, found in aberrant locations. They are benign lesions that are usually successfully treated by surgical excision. Here we present a rare case of a hairy polyp originating in the eustachian tube of a 7‐week‐old male, discuss our management of the patient, and put forth a new hypothesis as to the origin of these lesions.

Laryngoscope, 129:2398–2402, 2019
Association between audiometric patterns and probabilities of cardiovascular diseases
Authors: Bertrand Robert A. , Huang Zhaoxing
Published: October 2018

Objectives

The aim of this study was to analyze the progression of the audiometric pattern of serial screening tests in companies with hearing conservation program (HCP) to clinical audiometric tests to identify individuals more susceptible to develop cardiovascular diseases (CVDs). The procedure is based on the analysis of various audiometric patterns that have been demonstrated to have a statistically significant relation to certain CVDs. Identifying these individuals, based on pattern progression of hearing loss, could result in earlier detection to prevent disease or decrease its morbidity.

Study design

Using the data from the clinical and screening audiograms, pattern analysis was performed and statistical analysis using Fisher's exact test, odds ratios and P values were used to calculate the confidence intervals.

Methods

The analysis was based on potential risk factors related to CVD in 29 cohorts of 10,105 subjects. Of these, a total of 704 subjects also had clinical audiometric tests and examination by an ENT to verify the exactitude of the screening test questionnaire and pattern relation with the clinical audiogram.

Results

A first analysis was made on 704 subjects who had clinical evaluation and clinical audiometric tests showed results comparable to those of Friedland. A correlation between the questionnaire of the clinical and the self‐reporting screening tests questionnaires was performed and showed a correlation between the following risk factors: diabetes, hypertension, hyperlipidemia and smoking. Analysis of the progression of audiometric patterns suggested a relationship with the predictive probabilities of developing CVDs.

Conclusion

Progression toward low‐frequency hearing loss patterns provides early identification of patients whose audiometric pattern progression suggests increased probability of developing CVDs. The treating physician, by prescribing further investigations, could potentially prevent or reduce the morbidity of these diseases.

Level of Evidence

III
Biogeochemical tools for characterizing organic carbon in inland aquatic ecosystems
Authors: McCallister S. L. , Ishikawa N. F. , Kothawala D. N.
Published: October 2018

Integration of inland waters into regional and global carbon (C) budgets requires a comprehensive understanding of factors regulating organic carbon (OC) delivery and in situ processing. This study reviews advances in optical, molecular, and isotopic approaches to resolve the sources, ages, and transformations of OC in aquatic systems. OC characterization using excitation emission matrix spectra, Fourier transform ion cyclotron mass spectrometry, and nuclear magnetic resonance provides detailed molecular level insight. Radiocarbon isotopic approaches and compound‐specific techniques resolve the input, metabolic fate, and turnover time of OC in ecosystems ranging in size from streams to the open ocean. Accumulating evidence suggests that aquatic OC is composed of diverse biogeochemical components. We conclude with enduring and emerging questions that underscore the role of inland systems in the global C cycle and propose unique combinations of approaches to better discern their role in the delivery and transformation of OC from soils to seas.
A numerical approach to solve the model of an electromechanical system
Authors: Alkan Sertan , Aydin Merve Nilay , Coban Ramazan
Published: October 2018

In this paper, the model of an electromechanical system, which is a system of linear differential equations, is studied. Haar wavelet collocation method (HWCM) is applied for finding the approximate solution of the model. HWCM reduces the system of the model into a matrix‐vector form that contains the unknown Haar coefficients, and these coefficients are easily calculated. To demonstrate the validity and applicability of HWCM, numerical solutions of the system for different parameter values in the system are presented. The obtained results demonstrate the efficiency and accuracy of the method. All of the computations are performed via a program written in Mathematica.
Couple stress fluid flow with variable properties: A second law analysis
Authors: Jangili Srinivas , Adesanya Samuel Olumide , Ogunseye Hammed Abiodun , Lebelo Ramoshweu
Published: October 2018

The present work examines the combined influence of variable thermal conductivity and viscosity on the irreversibility rate in couple stress fluid flow in between asymmetrically heated parallel plates. The dimensionless fluid equations are solved by using homotopy analysis method (HAM) and validated with Runge‐Kutta shooting method (RKSM). The convergent series solution is then used for the irreversibility analysis in the flow domain. The effects of thermal conductivity and viscosity variation parameters, couple stress parameter, Reynolds number, Grashof number, Hartmann number on the velocity profile, temperature distribution, entropy production, and heat irreversibility ratio are presented through graphs, and salient features of the solutions are discussed. The computations show that the entropy production rate decreases with increased magnetic field and thermal conductivity parameters, whereas it rises with increasing values of couple stress parameter, Brinkman number, viscosity variation parameter, and Grashof number. The study is relevant to lubrication theory.
Approximation by an iterative method of a low‐Mach model with temperature dependent viscosity
Authors: Calgaro Caterina , Colin Claire , Creusé Emmanuel , Zahrouni Ezzeddine
Published: October 2018

In this work, we prove the existence and the uniqueness of the strong solution of a low‐Mach model, for which the dynamic viscosity of the fluid is a given function of its temperature. The method is based on the convergence study of a sequence towards the solution, for which the rates are also given. The originality of the approach is to consider the system in terms of the temperature and the velocity, leading to a nonlinear temperature equation and the development of some specific tools and results.
Stabilized mixed finite element methods for the Navier‐Stokes equations with damping
Authors: Li Zhenzhen , Shi Dongyang , Li Minghao
Published: October 2018

In this paper, the stabilized mixed finite element methods are presented for the Navier‐Stokes equations with damping. The existence and uniqueness of the weak solutions are proven by use of the Brouwer fixed‐point theorem. Then, optimal error estimates for the H1‐norm and L2‐norm of the velocity and the L2‐norm of the pressure are derived. Moreover, on the basis of the optimal L2‐norm error estimate of the velocity, a stabilized two‐step method is proposed, which is more efficient than the usual stabilized methods. Finally, two numerical examples are implemented to confirm the theoretical analysis.
Dose volume histogram‐based optimization of image reconstruction parameters for quantitative 90Y‐PET imaging
Authors: Siman Wendy , Mikell Justin K. , Mawlawi Osama R. , Mourtada Firas , Kappadath S. Cheenu
Published: October 2018

Purpose

90Y‐microsphere radioembolization or selective internal radiation therapy is increasingly being used as a treatment option for tumors that are not candidates for surgery and external beam radiation therapy. Recently, volumetric 90Y‐dosimetry techniques have been implemented to explore tumor dose–response on the basis of 3D 90Y‐activity distribution from PET imaging. Despite being a theranostic study, the optimization of quantitative 90Y‐PET image reconstruction still uses the mean activity concentration recovery coefficient (RC) as the objective function, which is more relevant to diagnostic and detection tasks than is to dosimetry. The aim of this study was to optimize 90Y‐PET image reconstruction by minimizing errors in volumetric dosimetry via the dose volume histogram (DVH). We propose a joint optimization of the number of equivalent iterations (the product of the iterations and subsets) and the postreconstruction filtration (FWHM) to improve the accuracy of voxel‐level 90Y dosimetry.

Methods

A modified NEMA IEC phantom was used to emulate clinically relevant 90Y‐PET imaging conditions through various combinations of acquisition durations, activity concentrations, sphere‐to‐background ratios, and sphere diameters. PET data were acquired in list mode for 300 min in a single‐bed position; we then rebinned the list mode PET data to 60, 45, 30, 15, and 5 min per bed, with 10 different realizations. Errors in the DVH were calculated as root mean square errors (RMSE) of the differences in the image‐based DVH and the expected DVH. The new optimization approach was tested in a phantom study, and the results were compared with the more commonly used objective function of the mean activity concentration RC.

Results

In a wide range of clinically relevant imaging conditions, using 36 equivalent iterations with a 5.2‐mm filtration resulted in decreased systematic errors in volumetric 90Y dosimetry, quantified as image‐based DVH, in 90Y‐PET images reconstructed using the ordered subset expectation maximization (OSEM) iterative reconstruction algorithm with time of flight (TOF) and point spread function (PSF) modeling. Our proposed objective function of minimizing errors in DVH, which allows for joint optimization of 90Y‐PET iterations and filtration for volumetric quantification of the 90Y dose, was shown to be superior to conventional RC‐based optimization approaches for image‐based absorbed dose quantification.

Conclusion

Our proposed objective function of minimizing errors in DVH, which allows for joint optimization of iterations and filtration to reduce errors in the PET‐based volumetric quantification 90Y dose, is relevant to dosimetry in therapy procedures. The proposed optimization method using DVH as the objective function could be applied to any imaging modality used to assess voxel‐level quantitative information.
Bulk Free‐Radical Co‐ and Terpolymerization of n‐Butyl Acrylate/2‐Ethylhexyl Acrylate/Methyl Methacrylate
Authors: Gabriel Vida A. , Dubé Marc A.
Published: October 2018

n‐Butyl acrylate (BA), 2‐ethylhexyl acrylate (EHA), and methyl methacrylate (MMA) are commonly used monomers in pressure‐sensitive adhesive formulations. The bulk free‐radical copolymerizations of BA/EHA, MMA/EHA, and BA/MMA are studied at 60 °C to demonstrate the use of copolymer reactivity ratios for the prediction of BA/MMA/EHA terpolymer composition. The reactivity ratios for BA/EHA and MMA/EHA copolymer systems are determined using low conversion experiments; BA/MMA reactivity ratios are already known from the literature. The reactivity ratio estimates for the BA/EHA system are r
BA  = 0.994 and r
EHA  = 1.621 and the estimates for MMA/EHA are r
MMA  = 1.496 and r
EHA  = 0.315. High conversion experiments are conducted to validate the reactivity ratios. The copolymer reactivity ratios are shown to predict terpolymer composition of high conversion BA/MMA/EHA experiments.
Magnetic resonance fingerprinting with quadratic RF phase for measurement of T2* simultaneously with δf, T1, and T2
Authors: Wang Charlie Yi , Coppo Simone , Mehta Bhairav Bipin , Seiberlich Nicole , Yu Xin , Griswold Mark Alan
Published: October 2018

Purpose

This study explores the possibility of using a gradient moment balanced sequence with a quadratically varied RF excitation phase in the magnetic resonance fingerprinting (MRF) framework to quantify T2* in addition to , T1, and T2 tissue properties.

Methods

The proposed quadratic RF phase‐based MRF method (qRF‐MRF) combined a varied RF excitation phase with the existing balanced SSFP (bSSFP)‐based MRF method to generate signals that were uniquely sensitive to , T1, T2, as well as the distribution width of intravoxel frequency dispersion, . A dictionary, generated through Bloch simulation, containing possible signal evolutions within the physiological range of , T1, T2, and , was used to perform parameter estimation. The estimated T2 and were subsequently used to estimate T2*. The proposed method was evaluated in phantom experiments and healthy volunteers (N = 5).

Results

The T1 and T2 values from the phantom by qRF‐MRF demonstrated good agreement with values obtained by traditional gold standard methods (r2 = 0.995 and 0.997, respectively; concordance correlation coefficient = 0.978 and 0.995, respectively). The T2* values from the phantom demonstrated good agreement with values obtained through the multi‐echo gradient‐echo method (r2 = 0.972, concordance correlation coefficient = 0.983). In vivo qRF‐MRF‐measured T1, T2, and T2* values were compared with measurements by existing methods and literature values.

Conclusion

The proposed qRF‐MRF method demonstrated the potential for simultaneous quantification of , T1, T2, and T2* tissue properties.
Development of a Questionnaire for the Reflective Practice of Nursing Involving Invasive Mechanical Ventilation: Assessment of validity and reliability
Authors: Tsukuda Makoto , Fukuda Atsuko , Taru Chiemi , Miyawaki Ikuko
Published: October 2018

Aim

To develop the Questionnaire for Reflective Practice of Nursing Involving Invasive Mechanical Ventilation (Q‐RPN‐IMV), a Japanese self‐evaluation instrument for ward nurses’ IMV practices.

Design

Cross‐sectional survey.

Methods

Participants were 305 ward nurses from five hospitals in Japan with nursing involving invasive mechanical ventilation. Items concerning the process of nursing practice, including the thought process related to ventilator care, were collected from the literature and observation and interviews with five IMV specialists. Construct validity, concurrent validity, internal consistency and test–retest reliability were tested.

Results

Initially, 141 items were collected and classified into three domains (i.e., observation, assessment and practice). Examination of exploratory factor analysis yielded five factors in the observation domain, six factors in the assessment domain and six factors in the practice domain. The data exhibited internal consistency, stability and concurrent validity. Items of practical content, including thoughts on ventilator care, are useful for preparing educational programmes.
Protein‐based bioadhesives and bioglues
Authors: Rathi Sneha , Saka Raju , Domb Abraham J. , Khan Wahid
Published: October 2018

Bioadhesives and glues are widely used as an adjunct to conventional methods employed in healing the post‐surgical injuries and restoration of normal tissue functions. Protein‐based bioadhesives have been used for a long time, and they are a more biocompatible alternative compared with synthetic adhesives. They offer advantages such as ease of application, reduction in surgery time, improved quality and strength of the seal, and effective sealing. Also, bioadhesives are being exploited in different fields like controlled and site‐specific drug delivery systems, and in tissue engineering and regeneration. There are various marketed protein‐based glues that are available in different forms. Thus, all in all, it is a patient compliant system, thereby increasing its recent popularity. This article provides insight into different types and sources of protein‐based bioadhesives, their history of use, mechanism of adhesion. and various products that have been approved by the regulatory authorities for clinical use. It also includes information regarding the products in clinical trials and potential applications.
Nanocomposite Containing Cross‐linked Poly(Methyl‐Methacrylate)/Multiwall Carbon Nanotube as a Selective Y3+ Sensor Probe
Authors: Hussein Mahmoud A. , Alam M. M. , Albeladi Hasinah K. , El‐Shishtawy Reda M. , Asiri Abdullah M. , Rahman Mohammed M.
Published: October 2018

This article explains how composite thin films, that are made of both cross‐linked poly(methyl methacrylate) (PMMA) and reinforced with multi‐walled carbon nanotube (CNTs), are designed, fabricated and developed for selective cationic sensing applications. The C‐PMMA‐CNTsa‐e nanocomposites were prepared by in situ cross‐linking reaction technique using 4,4′‐diaminobiphenyl (DABP) as the cross‐linking agent. Variable loading of CNTs varied from 2 to 40 wt% was utilized during the cross‐linking process. The nanocomposite films have been structurally characterized by Fourier transform infrared and XRD and the results confirm the incorporation of CNTs in the C‐PMMA matrix, while the dispersion of CNTs in C‐PMMA was characterized using SEM and TEM. The dispersion of CNTs in the composites was excellent, even at high CNTs loading as indicated by SEM and TEM. TEM images of C‐PMMA‐CNTs nanocomposites reveal a core‐shell structure in which CNTs as the core and C‐PMMA as the shell. The thermal features of the nanocomposite films were investigated through their TGA and DTG data. The results confirmed the importance of CNTs content in enhancing the thermal stability of the nanocomposite. The desired yttrium (Y3+) cation sensor was fabricated using glassy carbon electrode coating with a thin uniform layer of synthesized C‐PMMA‐CNTse nanocomposite. A calibration curve was plotted as current vs. concentration of Y3+ ion. The resulted calibration curve is found linear over linear dynamic range of 0.1 nM–0.1 mM. The slope of calibration curve is used to measure the sensitivity (27.2943 μA μM−1 cm−2), limit of detection (3.48 ± 0.17 pM), and limit of quantification (LOQ; 11.6 ± 0.57 pM) of Y3+ cation. It is also found as reliable sensor to detect Y3+ ion in real environmental samples. Considering the contamination of environment, this research might be reliable way for the development of future prospective cationic sensor for the safety of healthcare and ecological fields. POLYM. COMPOS., 40:E1673–E1684, 2019. © 2018 Society of Plastics Engineers
Residual wall thickness of water‐powered projectile‐assisted injection molding pipes
Authors: Kuang Tang‐Qing , Pan Jun‐Yu , Feng Qiang , Liu He‐Sheng , Xu Bai‐Ping , Liu Wen‐Wen , Turng Lih‐Sheng
Published: October 2018

Water‐powered projectile‐assisted injection molding (W‐PAIM) is an innovative molding process for the production of hollow shaped polymer parts. The W‐PAIM utilizes high pressure water as a power to drive a solid projectile to displace the molten polymer core to form the hollow space. The residual wall thickness (RWT) and its distribution are the important quality criteria. The experimental and numerical investigations were conducted. Experimental specimens showed that the RWT of a W‐PAIM pipe was much thinner than that of a water‐assisted injection molding pipe. The cross‐section size of the projectile defined the basic penetration section size. The software FLUENT was used to obtain the instantaneous distributions of the flow field, which revealed the forming mechanism of the RWT. The experiments indicated that the processing parameters, such as melt temperature, melt injection pressure, mold temperature, and water injection delay time had obvious effects on the RWT, while the water pressure had little effect on it. The RWT of curved pipes was thin at the inner concave side while thick at the outer convex side. The RWTs at the bend portion are influenced by the deflection angle and bending radius, which is due to the pressure difference between the two sides. POLYM. ENG. SCI., 59:295–303, 2019. © 2018 Society of Plastics Engineers
Improving the electrical conductivity of ethylene 1‐octene copolymer/cyclic olefin copolymer immiscible blends by interfacial localization of MWCNTs
Authors: Hosseinpour Ali , Nasseri Rasool , Ghiassinejad Sina , Mehranpour Milad , Katbab Ali Asghar , Nazockdast Hossein
Published: October 2018

The localization of multiwall carbon nanotubes (MWCNTs) in the immiscible blends of ethylene–1‐octene copolymer (EOC) and cyclic olefin copolymer (COC) with the sea–island morphology and electrical conductivity of resulting nanocomposites were investigated. Depending on the feeding orders, as the MWCNTs were located in the COC droplet, the electrical conductivity was obtained as high as 5.71 × 10−7 S/cm, while the MWCNTs were located in EOC/COC interface, the electrical conductivity increased significantly up to 1.72 × 10−2 S/cm. The improved electrical conductivity in EOE/COC/MWCNTs nanocomposite is attributed to the interfacial localization of MWCNTs which is resulted from thermodynamic affinity of MWCNTs to COC, as well as an interconnected structure via deformed and swelled COC droplets. Thermodynamic affinity of MWCNTs to COC and established interconnected structure are confirmed by rheological characterization, microscopic observations, dynamic mechanical analysis, and electrical conductivity measurements. Therefore, as a result of selective localization of MWCNTs and well‐designed phase morphology, lower rheological and especially electrical percolation thresholds could be obtained in the ternary nanocomposites compared to the binary systems. POLYM. ENG. SCI., 59:447–456, 2019. © 2018 Society of Plastics Engineers
Effect of aluminum oxide nanoparticles additives and gamma irradiation on the structural and optical properties of syndiotactic polystyrene
Authors: Elhady M. A. , Abdeldaym A.
Published: October 2018

Aluminum oxide nanoparticles (Al2O3) were prepared and the obtained structure and size of the prepared Al2O3nanoparticles were studied via X‐ray diffraction (XRD) and transmission electron microscopy. The effect of adding various concentrations of the Al2O3and gamma radiation on the structural and optical properties of syndiotactic polystyrene (sPS) were investigated using XRD and UV‐spectroscopy. XRD data showed that the addition of the various concentrations of the Al2O3influenced the crystallinity of the nanocomposites. A significant change in the lattice structure and the optical parameters were observed. The results showed that a sample with the Al2O3concentration of 10% achieved a higher refractive index and optical conductivity. Effect of gamma irradiation on sPS sample loaded with 10% Al2O3was studied. The results showed several changes in the structure and optical properties of the resulting films due to crosslinking between the polymer chains. This result reflects that the polymer suffered from structural rearrangement due to the irradiation treatments. POLYM. ENG. SCI., 59:555–565, 2019. © 2018 Society of Plastics Engineers
Effect of copolymers containing glycidyl methacrylate functional groups on the rheological, mechanical, and morphological properties of poly(ethylene terephthalate)
Authors: do Nascimento Walber Alexandre , Agrawal Pankaj , de Mélo Tomás Jeferson Alves
Published: October 2018

The aim of this work was to investigate the effect of ethylene‐glycidyl methacrylate (EGMA) and ethylene‐methyl acrylate‐glycidyl methacrylate (EMAGMA) copolymers on the rheological, mechanical, and morphological properties of Poly(ethylene terephthalate) (PET). The results of torque rheometry showed an increase in the torque of PET with the addition of EGMA and EMAGMA copolymers due to the reactions between the GMA groups present in the copolymers and the carboxyl and hydroxyl groups present in PET. The torque of PET/copolymer blends increased with the increase in the copolymer content and was more pronounced for the blends containing EGMA copolymer. X‐ray diffraction and differential scanning calorimetry analyzes showed that neat PET and the PET in PET/copolymer blends are amorphous. The addition of EGMA and EMAGMA copolymers delayed the crystallization of PET. Rheological measurements showed an increase in the viscosity at low frequencies with the addition of EGMA and EMAGMA copolymers to PET. This increase was more pronounced for PET/copolymer blends containing higher amount of copolymers and for the blends containing EGMA, corroborating the results obtained by torque rheometry. The impact strength of PET/EMAGMA blends was higher than that of PET/EGMA blends. Morphology analysis by SEM showed that PET/EMAGMA blends presented higher average dispersed phase domains size than PET/EGMA blends. POLYM. ENG. SCI., 59:683–693, 2019. © 2018 Society of Plastics Engineers
Preparation of stimulus‐responsive, polyfluorene‐wrapped carbon nanotubes via palladium cross coupling
Authors: Fong Darryl , Andrews Grace M. , Adronov Alex
Published: October 2018

Decoration of carbon nanotube surfaces without damaging nanotube optoelectronic properties is an ongoing challenge. Here, we utilize Sonogashira coupling chemistry to decorate the nanotube surface without perturbing optoelectronic properties. Reactive, noncovalently functionalized polymer–nanotube complexes were prepared using a polyfluorene with aryl iodide groups in its side chains. The aryl iodides enable Pd cross coupling between polymer–nanotube complexes and small molecules or polymers derivatized with an alkyne. Modestly efficient coupling was found to occur under dilute conditions at elevated temperatures. Successful coupling between aryl iodide and alkyne partners was observed using infrared spectroscopy via the appearance of carbonyl stretches that originate from covalently linked, carbonyl‐containing alkynes, and thermogravimetric analysis was used to measure reaction conversion under various conditions. Grafting of the hydrophobic polymer–nanotube complex with poly(ethylene glycol) enabled the dispersion to be transferred from organic to aqueous solution. This chemistry resulted in no damage to the nanotube sidewall, as evidenced by Raman spectroscopy. The aryl iodide‐containing polyfluorene–nanotube complex was also coupled to a photoswitchable alkyne‐containing spiropyran moiety and it was found that the photoswitch retained its functionality after coupling to the polymer–nanotube complex. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2723–2729
Structural and transport phenomena of urocanate‐based proton carrier in sulfonated poly(ether ether ketone) membrane composite
Authors: Nimmanpipug Piyarat , Kodchakorn Kanchanok , Lee Vannajan Sanghiran , Yana Janchai , Jarumaneeroj Chatchai , Phongtamrug Suttinun , Chirachanchai Suwabun
Published: October 2018

Proton transport is one of crucial phenomena in electrolytic part highly considered to overcome a limit in fuel cell efficiency improvement. Proton conducting organic electrolyte was modeled and simulated at atomistic level of calculation by doping of butyl urocanate (C4U), a composite material with imidazole substructure, with sulfonated poly(ether ether ketone) (SPEEK) amorphous membrane at various working temperature. Molecular dynamics simulations were used to investigate structural and dynamics characteristic of C4U in the membrane comparing with the SPEEK‐hydronium membrane model as a control. From simulations, thermal effect on water and proton carriers cluster surrounding the sulfonate groups was explored. At higher temperature, the more transport dynamics of C4U ions in SPEEK membranes were found than that of hydronium ions in the control system. Likewise, phase separation of hydrophobic and hydrophilic parts was taken into consideration here. A critical role of the enhancing proton conductivity by increasing the diffusion coefficient at temperature beyond C4U melting point in composite polymer membrane was emphasized. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 1625–1635
Risk of dermal and inhalation exposure to chlorantraniliprole assessed by using whole‐body dosimetry in Korea
Authors: Noh Hyun H , Lee Jae Y , Park Hyo K , Lee Jung W , Jo Seung H , Kim Jeong‐Han , Kwon Hyeyoung , Kyung Kee S
Published: October 2018

BACKGROUND

We determined the characteristics and evaluated associated risks of sprayed pesticide exposure among workers cultivating Korean cabbage. The test pesticide, a mixture of 3% chlorantraniliprole and 4% indoxacarb wettable granules diluted 2000 times, was sprayed on Korean cabbage within a 3000 m2 area in Goesan, Korea. Dermal exposures were measured using a whole‐body dosimetry method.

RESULTS

Exposure to chlorantraniliprole was observed among ten individuals, ranging from 140.4 to 4234.0 µg person−1. The legs were the most prominent exposure area (86.35%), with the face being the least exposed (0.06%). Exposure risk was assessed by calculating the margin of safety (MOS) on the exposure amount for each body part. The MOS based on dermal and inhalation exposure doses ranged from 59 to 1765.

CONCLUSION

Exposure was the greatest for the legs, probably as a result of the low height of the crop and the use of a long‐wand sprayer. An MOS value >1 indicates a low risk for applicators using this method of application. However, with tall crops, exposure level and MOS values can vary widely, as MOS increases or decreases based on exposure dose. Therefore, future research is needed to better understand appropriate safety precautions when working with potent pesticides. © 2018 Society of Chemical Industry
Absence of Evidence for Fixed Charge in Metal–Aluminum Oxide–Silicon Tunnel Diodes
Authors: Marstell Roderick J. , Pugliese Anthony , Strandwitz Nicholas C.
Published: October 2018

Here, a controlled variation in the fixed charge density (NF) and thickness of aluminum oxide tunnel insulators is reported, and the impact on Schottky barrier height in metal–insulator–semiconductor (MIS) diodes is studied. Analysis of metal–aluminum oxide–silicon capacitor structures indicates a change in NF from +1 × 1012 cm−2 in as‐deposited films to −2 × 1012 cm−2 in annealed films. An analytical model and numerical device physics simulations are used to predict changes in ­based on these changes in NF and alumina thickness. Surprisingly, Mott–Schottky derived values did not follow the trends predicted by these electrostatic models. In fact, there seems to be no discernable effect of NF in diodes with alumina thicknesses below 2 nm, contrary to contactless measurements of the fixed charge of films of similar thickness. The trends are better explained by a dipole model. It is further shown that in as‐deposited MIS diodes, the dipole is a function of alumina layer thickness, whereas in annealed MIS diodes, the dipole and were roughly constant independent of alumina thickness. These data suggest a strategy by which the of MIS tunnel contacts can be controlled and which has implication for the design of electrical contacts.
Studies towards the Synthesis of Portentol
Authors: Kumar Gavireddy Chaithanya , Satyanarayana Vavilapalli , Muralikrishna Katta , Yadav Jhillu Singh
Published: October 2018

A highly stereoselective and competent approach for studies towards the synthesis of Portentol has been described. The salient features of the synthesis are the utilization of desymmetrization protocol, Crimmin's non‐Evans syn aldol reaction, C−C bond formation through an intermolecular Aldol reaction and Barton‐McCombie deoxygenation.
Preparation of Water‐Soluble CsPbBr3 Perovskite Quantum Dot Nanocomposites via Encapsulation into Amphiphilic Copolymers
Authors: Lee See Mak , Jung Hyunsung , Park Woon Ik , Lee Younki , Koo Eunhae , Bang Jiwon
Published: October 2018

Water‐dispersible and stable fluorescent CsPbBr3 perovskite quantum dots (QDs)‐loaded polymeric nanospheres were prepared by an emulsification process. Colloidal CsPbBr3 QDs that were initially prepared in organic solvents were transferred to an aqueous solution by coating with non‐ionic amphiphilic polymers, viz., poly(ethyleneoxide)‐poly(propyleneoxide)‐poly(ethyleneoxide) triblock‐copolymer and polyethylene glycolylated hydrogenated castor oil. The polymer‐encapsulated CsPbBr3 QDs‐loaded nanospheres have an average diameter of ∼55 nm and they disperse well in aqueous solutions without aggregation or flocculation. The fabricated CsPbBr3 QDs‐loaded nanospheres retain their luminescence properties in pure and salt‐containing water, which indicates that the polymeric shell of the QDs‐polymer nanospheres effectively blocks the diffusion of water and ions into the nanospheres. The results of this study might open many new possibilities for the fluorescent cesium lead halide QDs in a wide variety of applications; for example, they can serve as fluorescent bio‐imaging probes.
The Optical Diode Ideality Factor Enables Fast Screening of Semiconductors for Solar Cells
Authors: Babbe Finn , Choubrac Leo , Siebentritt Susanne
Published: October 2018

In the search for new materials for solar cells, a fast feedback is needed. Radiative efficiency measurements based on photoluminescence (PL) are the tool of choice to screen the voltage a material is capable of. Additionally the dependence of the radiative efficiency on excitation density contains information on the diode ideality factor, which determines in turn the fill factor of the solar cell. Both parameters are immediate ingredients of the efficiency of a solar cell and can be determined from PL measurements, which allow fast feedback. The method to determine the optical diode ideality factor from PL measurements and compare to electrical measurements in finished solar cells are discussed.
Estimation of Outlet Temperature of a Flow Reactor Heated by Microwave Irradiation
Authors: Takeda Kazuhiro , Yanagi Nana , Nonaka Keisuke , Mase Nobuyuki
Published: October 2018

Flow reactors heated by microwave irradiation attract attention. The reactors are suitable for difficult synthesis processes due to rapid heating and cooling, and easy pressurization. In order to predict the quality of the product, it is appropriate to estimate the outlet conditions of the reactor. In this paper, the outlet temperature of the flow direction is estimated by using the flow condition and dynamic thermal energy balance of the reactor.
Molecular Design Tactics for Highly Efficient Thermally Activated Delayed Fluorescence Emitters for Organic Light Emitting Diodes
Authors: Konidena Rajendra Kumar , Lee Jun Yeob
Published: October 2018

Recently, pure organic thermally activated delayed fluorescence (TADF) emitters have attracted considerable interest from the scientific community in the field of organic light emitting diodes (OLEDs) as they can theoretically realize 100 % of the internal quantum efficiency by exploiting both the singlet and triplet excitons via the reverse intersystem crossing enabled by small singlet‐triplet energy splitting. Currently, the external quantum efficiency of the TADF emitters is reaching the level of phosphorescent emitters. Therefore, the TADF approach is considered as a potential alternative to the low efficiency conventional fluorescent and expensive phosphorescent emitters. In this account, we summarized our recent development of blue and green TADF molecular designs to improve the device performances of the TADF devices.
Peptide Nanomaterials Designed from Natural Supramolecular Systems
Authors: Inaba Hiroshi , Matsuura Kazunori
Published: October 2018

Natural supramolecular assemblies exhibit unique structural and functional properties that have been optimized over the course of evolution. Inspired by these natural systems, various bio‐nanomaterials have been developed using peptides, proteins, and nucleic acids as components. Peptides are attractive building blocks because they enable the important domains of natural protein assemblies to be isolated and optimized while retaining the original structures and functions. Furthermore, the peptide subunits can be conjugated with exogenous molecules such as peptides, proteins, nucleic acids, and metal nanoparticles to generate advanced functions. In this personal account, we summarize recent progress in the construction of peptide‐based nanomaterial designed from natural supramolecular systems, including (1) artificial viral capsids, (2) self‐assembled nanofibers, and (3) protein‐binding motifs. The peptides inspired by nature should provide new design principles for bio‐nanomaterials.
“What am I going to do?” A veteran teacher's journey of teaching writing to newcomer English language learners
Authors: Andrei Elena , Ellerbe Marcie , Kidd Brenda
Published: October 2018

This study looks at the reflections on successes and challenges of an English language arts (ELA) veteran teacher on teaching writing to two newcomer English language learners (ELLs). The research questions are as follows: (1) What does the veteran ELA teacher identify as challenges and successes in her reflections on teaching writing to two newcomer ELLs? (2) What does the veteran ELA teacher identify as new learnings about teaching ELLs in her reflections on teaching writing to two newcomer ELLs? Data consisted of documents the teacher submitted as part of an independent study: a journal, a presentation, and an essay. The themes identified during qualitative analysis of the data highlight the challenges and successes of specific classroom activities and strategies and their effect on ELL progress and on the teacher's self‐assessment.