bluuebunny/crossref_metadata_2025 huggingface dataset:
The conversion of glycerol to methyl lactate catalyzed by tin‐exchanged montmorillonite‐supported gold catalysts
Authors: Li Jifan , Li Duo , Liu Chun‐Ling , Xu Chunli , Dong Wen‐Sheng
Published: February 2019

BACKGROUND

Glycerol is a versatile platform compound to produce valuable chemicals. One‐pot direct conversion of glycerol into methyl lactate with methanol as solvent is very attractive, because it can reduce intermediate steps and avoid the separation of glycerol/methanol mixtures.

RESULTS

A series of tin (Sn)‐exchanged montmorillonite(M)‐supported Au catalysts were prepared by a combination of ion exchange and colloidal deposition methods, and designed as bifunctional catalysts containing gold (Au) and solid acid. These catalysts were employed for one‐pot conversion of glycerol to methyl lactate in methanol. The Au/Sn(20)‐Mt catalyst gave a high yield of methyl lactate of 54% upon conversion of 0.25 mol L–1 glycerol methanol solution over 0.07 g catalyst at 210 °C under 3 MPa air for 5 h. The good performance of Au/Sn(20)‐Mt was ascribed to the coexistence of small Au particle and abundance of acid sites. The glycerol conversion remained almost unchanged in the five recycled runs, whereas the methyl lactate yield decreased after the first run but kept stably in the later four catalytic runs.

CONCLUSIONS

Among the series of Sn‐exchanged Mt‐supported Au catalysts, Au/Sn(20)‐Mt showed the highest glycerol conversion and methyl lactate yield. Containing both small Au particles and having an abundance of acid sites contributed to the excellent catalytic activity of Au/Sn(20)‐Mt. © 2019 Society of Chemical Industry
Sample preparation method for visualization of nanoparticulate captured on mixed cellulose ester filter media by enhanced darkfield microscopy and hyperspectral imaging
Authors: Neu‐Baker Nicole M. , Eastlake Adrienne C. , Brenner Sara A.
Published: February 2019

A significant hurdle in conducting effective health and safety hazard analysis and risk assessment for the nanotechnology workforce is the lack of a rapid method for the direct visualization and analysis of filter media used to sample nanomaterials from work environments that represent potential worker exposure. Current best‐known methods include transmission electron microscopy (TEM) coupled with energy dispersive x‐ray spectroscopy (EDS) for elemental identification. TEM‐EDS is considerably time‐, cost‐, and resource‐intensive, which may prevent timely health and safety recommendations and corrective actions. A rapid screening method is currently being explored using enhanced darkfield microscopy with hyperspectral imaging (EDFM‐HSI). For this approach to be effective, rapid, and easy, sample preparation that is amenable to the analytical technique is needed. Here, we compare the sample preparation steps for mixed cellulose ester (MCE) filter media specified in NIOSH Method 7400—Asbestos and Other Fibers by Phase Contrast Microscopy (PCM)—against a new method, which involves saturation of the filter media with acetone. NIOSH Method 7400 was chosen as a starting point since it is an established technique for preparing transparent MCE filters for optical microscopy. Limitations in this method led to the development and comparison of a new method. The new method was faster, easier, and rendered filters more transparent, resulting in improved visualization and analysis of nanomaterials via EDFM‐HSI. This new method is suitable for a rapid screening protocol due to its speed, ease of use, and the improvement in image acquisition and analysis.
A reproducing kernel Hilbert space method for solving the nonlinear three‐point boundary value problems
Authors: Foroutan Mohammadreza , Asadi Raheleh , Ebadian Ali
Published: February 2019

The main objective of this paper is to present a reproducing kernel Hilbert space method for computing solutions of nonlinear third‐order ordinary differential equations under multipoint boundary conditions. Some other aspects of the reproducing kernel Hilbert space method, such as convergence analysis and error estimate, are also discussed. The proposed method is a well‐performance technique for calculating the best approximate solution of nonlinear boundary value problems. Our numerical experiments validate our theoretical findings and demonstrate the desirable performance of the algorithm in terms of simplicity, accuracy, and efficiency.
Exploring the response of Actinobacteria to the presence of phosphorus salts sources: Metabolic and co‐metabolic processes
Authors: Solans Mariana , Messuti María I. , Reiner Gabriela , Boenel Micaela , Vobis Gernot , Wall Luis G. , Scervino Jose M.
Published: February 2019

This study tested the solubilization of phosphorus by five actinobacterial strains in liquid media containing Ca3PO4; AlPO4 or FePO4 as the sole phosphate source, and discusses the possible mechanisms involved in this process. P solubilization by different strains was accompanied by a significant drop in pH from 7.0 to 2.15–5.0 after 14 days. The efficiency of different strains depended on the P‐source. Streptomyces spp. MM140 and MM141 were the most efficient in solubilizing Ca3PO4, MM136, and MM141 were the most efficient in solubilizing AlPO4, while all strains were equally efficient in solubilizing FePO4. Gluconic, oxalic, citric, malic, succinic, formic, and acetic acid were detected in the medium with Ca3PO4, while all except acetic acid were detected in the media with FePO4 or AlPO4. Although we did not use an organic source of phosphorus in the media, all strains produced acid and alkaline phosphatase. It is concluded from this study that actinobacteria produced multiple organic acids followed by a decrease in the pH to solubilize phosphate salts. As well as producing phosphatase, these microorganisms were found to have different ways of making P available, suggesting an ecological advantage as they form part of soil microbiomes important for plants.
Teachers’ Beliefs of Creative Children
Authors: Paek Sue Hyeon , Sumners Sarah E. , Sharpe Desiree I.
Published: February 2019

Teachers’ beliefs about characteristics of creative children do not always align with how creative children actually behave. Understanding these misaligned beliefs—defined as misconceptions—is important because teachers’ misconceptions can undermine efforts to foster children's creative development. This study aimed to identify teachers’ beliefs about the characteristics of creative children with an emphasis on their misconceptions about characteristics as either indicative or contraindicative of creative children. We analyzed responses of 136 teachers to 29 characteristics, indicating or contraindicating creative children, on Gough's (1979). Creative Personality Scale using the Rating Scale Model. Results revealed that teachers tended to have more misconceptions about characteristics contraindicative of creative children than characteristics indicative of creative children while teachers were able to accurately recognize certain characteristics when compared with explicit theories of creativity. In both the indicative and contraindicative characteristics, misconceptions appeared to increase if characteristics were desirable in the classroom. Teachers’ misconceptions may conceal creative potential in children who do not manage their undesirable characteristics in constructive ways. Findings provide practical implications to aid teachers and teacher educators in correcting misconceptions about the characteristics of creative children.
Effect of lactoferrin on physicochemical properties and microstructure of pullulan‐based edible films
Authors: Zhao Zhengtao , Xiong Xiong , Zhou Hui , Xiao Qian
Published: February 2019

BACKGROUND

Pullulan is a polysaccharide polymer commonly used to produce edible films. However, pure pullulan film is usually brittle and very hydrophilic, which limit its use in both food and pharmaceutical fields. The objective of this research is to improve the structural and mechanical properties of pullulan film by incorporating globular protein lactoferrin (LF).

RESULTS

The incorporation of LF increased the surface hydrophobicity and decreased the water vapor permeability (WVP) of pullulan film. The presence of low concentrations of LF (< 0.03%) has no significant influence on tensile strength (TS) and elongation at break (EAB) of pullulan film. However, further increase of LF concentration to levels > 0.03% resulted in a film‐weakening effect. LF molecules aggregated with each other during the film‐producing process, which presented as spherical particles from the observation of microscopy. LF aggregates dispersed homogeneously throughout the pullulan matrix and their size increased with increasing concentration. Analysis from Fourier transform infrared spectroscopy indicated that the secondary structure of LF molecules was modified during the drying process.

CONCLUSIONS

It is possible to increase the hydrophobicity of pullulan film while maintaining its mechanical properties. The produced composite film can be potentially used for food and medical packaging. © 2019 Society of Chemical Industry
Polypropylene Nanocomposite Employing Sodium Clay as Support for an Isospecific Metallocene Complex
Authors: Maria de Fátima V. Marques , Rocha Luiz F. M. , dos Santos Adriana R.
Published: February 2019

Propylene polymerization was performed using homogeneous and supported rac‐SiMe2(2‐Me‐Ind)2ZrCl2 catalysts. The supports used were commercial sodic bentonites from different sources. The influence of polymerization time and nature of catalyst support on the nanocomposites syntheses and the consequent properties of obtained composites, were evaluated at two different reaction temperatures and with two cocatalyst systems (MAO and a mixture of MAO/TIBA). The highest catalytic activities were obtained at 60 °C with the cocatalyst mixture MAO/TIBA in the reaction medium. Polymerization rate profiles were obtained as well as melting and crystallization temperatures, crystallinity degree, isotactic index, and number‐average molecular weight. The polypropylene produced with the supported catalyst pretreated with TIBA instead of MAO showed higher crystallinity degree, melting and crystallization temperatures, however, it presented lower catalyst activity. Clay exfoliation was verified by the absence of diffraction peak in the range of 2θ from 2.5° to 7° of X‐ray diffractometry analyses and by transmission electron microscopy. The thermogravimetric analyses showed an increase of PP degradation temperature of above 70 °C when synthesized with clay supported catalysts in relation to the PP obtained by means of homogeneous system.
Size and Vitamin E Release of Nanostructured Lipid Carriers with Different Liquid Lipids, Surfactants and Preparation Methods
Authors: de Souza Ingrid D. L. , Saez Vivian , de Campos Vânia E. B. , Mansur Cláudia R. E.
Published: February 2019

Solid lipid nanoparticles have excellent properties as delivery systems for dermal cosmetic and pharmaceutical formulations because they have good compatibility with the skin, protect the encapsulated substance from the medium, and control its release at the site of action. This work describes the preparation and characterization of nanostructured lipid carriers (NLC) containing vitamin E (NLC‐VE). The emulsion‐solidification technique was used to prepare the particles. Three non‐ionic surfactants (Tween 80, Cremophor RH40 and Pluronic F‐127) were used in two concentrations (5 and 10% (w/w)) and three liquid lipids (avocado oil, coconut oil and medium chain triglycerides (MCT)) were mixed with the solid lipid (stearic acid) to form the oil phase. Some processing variables (emulsification procedure, and time and energy during sonication) were modified to find the most suitable NLC in terms of particle size and release profile. Higher surfactant concentration produced more homogeneous nanoparticles with smaller diameter. The liquid lipid and its proportion in the oil phase also modified the characteristics of NLC‐VE. Time and sonication energy did not strongly affect the particle size (24–28 nm), with the exception of the highest time and amplitude, which produced particles with 14 nm. NLC‐VE prepared with stearic acid as solid lipid, 10% (w/w) Tween 80 as surfactant, and MCT as liquid lipid in a 1:3 mass proportion of solid lipid‐to‐liquid lipid, had a unimodal size distribution and the best vitamin E release (50% in 24 h). Results indicate that this system can be used to improve the delivery of vitamin E.
New Strategy to Prepare Luminescent Blend by Spin Coating
Authors: Menandro Alessandra S. , Parolin Giovana A. , Barbosa Camila G. , Faez Roselena , Péres Laura O.
Published: February 2019

The use of blends can be a strategy to obtain new properties or to optimize already existing properties in one of the polymers. In luminescent blends, the presence of a non‐conjugated polymer can maximize its emitting properties. However, the parameters to form this blend are fundamental to obtain homogeneous, translucent and good emission films. The present work analyzed parameters such as solution concentration, solvent, and amount of conjugated polymer, drying time, and drying temperature in order to obtain a luminescent blend. The results showed that these parameters are important in the absorption and emission of the materials, and as little as 5 wt% of the conjugated polymer in the blend allows obtaining an emitting blend with few aggregates.
Hybrid Microporous Membranes Applied in Wastewater Treatment
Authors: de Medeiros Keila M. , da N. Medeiros Vanessa , de F. Lima Diego , de Lima Carlos A. P. , Araújo Edcleide M. , de L. Lira Hélio
Published: February 2019

In this work, membranes of pure polyamide 6 (PA6) and hybrids with 1, 3, and 5% in weight of organophilic montmorillonite (OMMT) clay in the form of thin porous films are obtained by the phase inversion technique. The membranes are characterized by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), contact angle (CA), and flow measurements (FM). Through X‐ray diffraction, it is revealed that the hybrid membranes with OMMT have an exfoliated and/or partially exfoliated structure. From FTIR and DSC analyses of hybrid membranes with OMMT, it is found that the spectra and the crystalline melting temperature remained practically unchanged compared to PA6 membrane. From the SEM, it is verified that the addition of the clay caused an increase in the quantity and uniformity of pores distribution in the surface and cross section of these membranes. By MIP, it is observed that the presence of clay in the membrane caused an increase in the average pore diameters. By the contact angle, it is verified that the membrane with clay had a higher value of contact angle for the distilled water when compared to the angle obtained with the synthetic oil. The water flux of the membrane with clay is higher than that obtained by the membrane of pure PA6, due its surface structure with larger pore diameters, favoring its permeability. The obtained hybrid membrane presented adequate porosity morphology for wastewater treatment.
Study of Miscibility, Crystallization, and Biodegradation of Casting Films of Poly(butylene succinate‐co‐adipate) and Poly(ϵ‐Caprolactone) Blends
Authors: Batista Nicolino Marcos Vinícius , Oliveira Passos Marco Aurélio , Branciforti Marcia Cristina
Published: February 2019

This work presents the miscibility and crystallization evaluations of poly (butylene succinate‐co‐adipate) (PBSA) and poly (ϵ‐caprolactone) (PCL) blends by dynamic‐mechanical thermal analysis (DMTA) and polarized light optical microscopy (PLOM), as well as the assessment of biodegradability of pure polymers and its blends in compost soil. DMTA and PLOM results confirmed the immiscibility of the blends and pointed to the possibility of compatibility between the blend components of various compositions. Soil burial biodegradation assay demonstrates that the blends showed a higher biodegradation rate than pure polymers. Overall, results indicate that it is possible to improve mechanical properties by blending PBSA with PCL, without losing biodegradation properties.
Incorporation of Oregano Essential Oil Microcapsules in Starch‐Poly (Butylene Adipate Co‐Terephthalate) (PBAT) Films
Authors: de Medeiros João Augusto Salviano , Blick Ana Paula , Galindo Marcella V. , Alvim Izabela D. , Yamashita Fabio , Ueno Cláudio Takeo , Shirai Marianne Ayumi , Grosso Carlos Raimundo Ferreira , Corradini Elisângela , Sakanaka Lyssa Setsuko
Published: February 2019

Summary Cassava starch and poly(butylene adipate‐co‐terephthalate) (PBAT) based films containing microencapsulated oregano essential oil (OEO) and free OEO are produced by blow extrusion. Microcapsules produced by ionic gelation were characterized with respect to average size, morphology, and encapsulation efficiency. The microcapsules were spherical and ranged in size from 20 to 1000 μm. Encapsulation efficiency (EE) is 83%. The films are analyzed in terms of their morphology, mechanical properties, water vapor permeability (WVP) and antibacterial properties. The films containing OEO microcapsules exhibited lower ultimate tensile strength, Young's modulus and elongation at break than the control films and the films containing free OEO. The WVP of films containing free OEO is slightly lower, while that of films containing microencapsulated OEO did not differ significantly from the control films. Scanning electron microscopy (SEM) images showed that the surface of films containing microencapsulated OEO are less homogeneous than those of the control and free OEO films. Films containing free or microencapsulated OEO presented inhibitory activity against Staphylococcus aureus, but not against Escherichia coli.
Influence of Encapsulated Aroma Compounds on the Formation and Morphology of Gelatin Microparticles
Authors: da Silva Maíra Taynara Santos , Pinto José Carlos
Published: February 2019

In the present work aromatic essential oils obtained from orange (OO), basil (BO), cinnamon (CNO), and citronella (CO) were encapsulated in natural gelatin matrices through inverse suspension processes and the effects of oil encapsulation on the formation and morphology of the obtained gelatin microspheres were analyzed. Particularly, it is shown that each oil affected the course of the encapsulation process differently, leading to decrease of the viscosity of the dispersed phase of almost 70% during the reaction course, when compared with oil‐free gelatin solutions. Additionally, the interfacial tensions of the aqueous solutions containing essential oils were slightly higher than in absence of oils. Particle size distributions of the final particles were relatively broad, while the obtained beads presented spherical morphology and irregular surfaces. Finally, the thermal resistances of the oil‐containing microparticles were higher than observed in absence of oil, despite the relatively low oil contents of the final products.
Analysis of PVC Produced With An Environmentally Friendly Additive Exposed to Gamma Radiation
Authors: da Silva Lindomar Avelino , Araújo Carlos Henrique Lucena , Madaleno Emerson , de Araújo Elmo Silvano , da Silva Aquino e Kátia Aparecida
Published: February 2019

Commercial Poly(vinyl chloride) (PVC) compounds are based on the combination of the polymer and additives that gives the formulation necessary for the end‐use. In medical‐device applications, PVC may be treated by gamma irradiation in sterilization process. As a consequence of ionization during irradiation, PVC chains undergo simultaneously crosslinking and scission effects. Therefore, it is necessary the study of new additives with radiolytic stabilization characteristics. In this study, the vegetable oil extracted from coffee grounds (OCG) was incorporated in PVC resin as an additive to produce PVC films and PVC test specimens. The viscosity measurements showed that OCG is a promising radioprotection at 0.5 wt% concentration. The results of mechanical and thermal properties are also discussed. The aim of this study is to show that it is possible to develop a formulation for processing PVC with radiation resistance and, at the same time, friendly to the environment due to recycle the wastes from coffee industry.
Modified laser beam welding of aluminum‐silicon coated 22MnB5
Authors: Gerhards B. , Engels O. , Olschok S. , Reisgen U.
Published: February 2019

Press hardened 22MnB5 is an excellent structural material, but there are several issues when it comes to welding. Especially in the case of overlap joint laser welding, the most severe issue is precipitation of the aluminium silicon (AlSi) coating at the fusion line. If the coating remains on the sheets, an ultimate strength of 20 kN with a crack initiation at the fusion line is reached in tensile tests instead of 30 kN with a crack initiation in the heat affected zone (HAZ) when the coating is removed prior to welding. In the presented work, the influence of coating on the material properties as well as the structure of the precipitation at the fusion line are examined and discussed. It is stated that the precipitation does not consist of AlxFey intermetallic phases, but of an iron, aluminium and silicon solid solution. The fractured surfaces of tensile tests show brittle behavior for the precipitation and ductile behavior for areas where the crack propagated through the steel. A modified beam oscillation in the shape of a recumbent “8” in welding direction is introduced. It was possible to increase the ultimate strength by 10 kN and nearly double the possible elongation.
The regulation of oxidative phosphorylation pathway on Vibrio alginolyticus adhesion under adversities
Authors: Huang Li , Huang Lixing , Zhao Lingmin , Qin Yingxue , Su Yongquan , Yan Qingpi
Published: February 2019

Vibrio alginolyticus is one of the most important pathogens in mariculture and leading to heavy losses. After treatment with Cu2+, Pb2+, and low pH, the expression of oxidative phosphorylation pathway genes, including coxA, coxB, coxC, ccoN, ccoO, and ccoQ, was found commonly downregulated by RNA‐seq as well as quantitative real‐time PCR. RNAi significantly reduced the expression of coxA, coxB, coxC, ccoN, ccoO, and ccoQ in V. alginolyticus. Compared with the wild‐type strain, the adhesion abilities of RNAi strains of V. alginolyticus were significantly impaired, as well as their cytochrome C oxidase activity. ccoQ appeared to be more important in the regulation of bacterial adhesion in these target genes, while ccoO was relatively weak in the regulation of the adhesion. Meanwhile, the changes of temperature, salinity, pH, and starvation affected coxA, coxB, coxC, ccoN, ccoO, and ccoQ expression remarkably. These findings indicated that: the oxidative phosphorylation pathway is a critical regulator of adhesion in V. alginolyticus; coxA, coxB, coxC, ccoN, ccoO, and ccoQ regulate the bacterial adhesion in response to environmental changes such as temperature, salinity, pH, and starvation.
MLR, PLSR‐BR Analysis and MBPLSR to Interpret Multivariate QSPR Models. The Case of a Micellar Liquid Chromatography Descriptor (log KWSDS)
Authors: Ermondi Giuseppe , Caron Giulia
Published: February 2019

Improving the interpretability of multivariate QSPR models is a major issue in modern drug discovery. In this study we applied three strategies to model and deconvolute the balance of intermolecular forces governing log KWSDS, a chromatographic descriptor of potential relevance in the prediction of ADME phenomena.

A dataset of 77 compounds was set‐up and an ad hoc pool of VS+ descriptors calculated. The data matrix was firstly submitted to a PCA run for a preliminary analysis and outliers detection. To model and interpret log KWSDS three chemoinformatic approaches implementing either variable selection or grouping tools were used: a) MLR and GA, b) PLSR combined with BR analysis and c) MBPLSR. Results provided by the three methods were largely superposable both in terms of prediction performances and mechanistic interpretation. Overall, they showed that log KWSDS is a complex descriptor mainly governed by the dimension, polarity and HBD solutes’ properties.

Chemoinformatic strategies as those reported in this paper might be applied to any chromatographic system and thus represent a potent tool to exploit the full potential of chromatographic descriptors in pharmaceutical, toxicological and related sciences.
Long‐term safety and efficacy of eculizumab in generalized myasthenia gravis
Authors: Muppidi Srikanth , Utsugisawa Kimiaki , Benatar Michael , Murai Hiroyuki , Barohn Richard J. , Illa Isabel , Jacob Saiju , Vissing John , Burns Ted M. , Kissel John T. , Nowak Richard J. , Andersen Henning , Casasnovas Carlos , de Bleecker Jan L. , Vu Tuan H. , Mantegazza Renato , O'Brien Fanny L. , Wang Jing Jing , Fujita Kenji P. , Howard James F. ,   for the Regain Study Group
Published: February 2019

Introduction: Eculizumab is effective and well tolerated in patients with antiacetylcholine receptor antibody‐positive refractory generalized myasthenia gravis (gMG; REGAIN; NCT01997229). We report an interim analysis of an open‐label extension of REGAIN, evaluating eculizumab's long‐term safety and efficacy. Methods: Eculizumab (1,200 mg every 2 weeks for 22.7 months [median]) was administered to 117 patients. Results: The safety profile of eculizumab was consistent with REGAIN; no cases of meningococcal infection were reported during the interim analysis period. Myasthenia gravis exacerbation rate was reduced by 75% from the year before REGAIN (P < 0.0001). Improvements with eculizumab in activities of daily living, muscle strength, functional ability, and quality of life in REGAIN were maintained through 3 years; 56% of patients achieved minimal manifestations or pharmacological remission. Patients who had received placebo during REGAIN experienced rapid and sustained improvements during open‐label eculizumab (P < 0.0001). Discussion: These findings provide evidence for the long‐term safety and sustained efficacy of eculizumab for refractory gMG. Muscle Nerve 2019
Fat suppression for ultrashort echo time imaging using a single‐point Dixon method
Authors: Jang Hyungseok , Carl Michael , Ma Yajun , Jerban Saeed , Guo Tan , Zhao Wei , Chang Eric Y. , Du Jiang
Published: February 2019

Purpose

In ultrashort echo time (UTE) imaging, fat suppression can improve short T2* contrast but can also reduce short T2* signals. The conventional two‐point Dixon (2p‐Dixon) method does not perform well due to short T2* decay. In this study, we propose a new method to suppress fat for high contrast UTE imaging of short T2 tissues, utilizing a single‐point Dixon (1p‐Dixon) method.

Methods

The proposed method utilizes dual‐echo UTE imaging, where UTE is followed by the second TE, chosen flexibly. Fat is estimated by applying a 1p‐Dixon method to the non‐UTE image after correction of phase errors, which is used to suppress fat in the UTE image. In vivo ankle and knee imaging were performed at 3 T to evaluate the proposed method.

Result

It was observed that fat and water signals in tendons were misestimated by the 2p‐Dixon method due to signal decay, while the 1p‐Dixon method showed reliable fat and water separation not affected by the short T2* signal decay. Compared with the conventional chemical shift based fat saturation technique, the 1p‐Dixon based approach showed much stronger signal intensities in the Achilles, quadriceps, and patellar tendons, with significantly improved contrast to noise ratios (CNRs) of 11.8 ± 2.2, 16.0 ± 1.6, and 26.8 ± 1.3 with the 1p‐Dixon method and 0.6 ± 0.2, 4.6 ± 1.0, and 17.5 ± 1.4 with regular fat saturation, respectively.

Conclusion

The proposed 1p‐Dixon based fat suppression allows more flexible selection of imaging parameters and more accurate fat and water separation over the conventional 2p‐Dixon in UTE imaging. Moreover, the proposed method provides much improved CNR for short T2 tissues over the conventional fat saturation method.
On error controlled numerical model reduction in FE2‐analysis of transient heat flow
Authors: Ekre Fredrik , Larsson Fredrik , Runesson Kenneth
Published: February 2019

Numerical model reduction is exploited for solving the two‐scale problem that arises from the computational homogenization of a model problem of transient heat flow. Since the problem is linear, an orthogonal basis is obtained via the method of spectral decomposition. A key feature is the construction of a symmetrized version of the space‐time variational format, by which it is possible to estimate the error from the model reduction in (i) energy norm and in (ii) a given quantity of interest. In previous work by the authors, this strategy has been applied to the solution of an individual representative volume element problem, whereas the error transport to the macroscale problem in the finite element squared (FE2) approach was ignored. In this paper, such transport of error is included in the error estimate. It is remarkable that it is (still) possible to obtain guaranteed bounds on the error, as compared to the fully resolved discrete finite element problem, while using only the reduced basis and with minor extra computational effort. The performance of the error estimates is demonstrated via numerical results, whereby the subscale is modeled in three dimensions, whereas the macroscale problem is either one or two dimensional.
Time evolution of discrete fourth‐order elliptic operators
Authors: Ben‐Artzi Matania , Croisille Jean‐Pierre , Fishelov Dalia
Published: February 2019

The evolution equation is considered. A discrete parabolic methodology is developed, based on a discrete elliptic (fourth‐order) calculus. The main ingredient of this calculus is a discrete biharmonic operator (DBO). In the general case, it is shown that the approximate solutions converge to the continuous one. An “almost optimal” convergence result (O(h4 − ϵ)) is established in the case of constant coefficients, in particular in the pure biharmonic case. Several numerical test cases are presented that not only corroborate the theoretical accuracy result, but also demonstrate high‐order accuracy of the method in nonlinear cases. The nonlinear equations include the well‐studied Kuramoto–Sivashinsky equation. Numerical solutions for this equation are shown to approximate remarkably well the exact solutions. The numerical examples demonstrate the great improvement achieved by using the DBO instead of the standard (five‐point) discrete bilaplacian.
Food security and access to healthy foods in Indian country: Learning from the Food Distribution Program on Indian Reservations
Authors: Pindus Nancy , Hafford Carol
Published: February 2019

Food access, food security, and nutrition‐related health disparities have long been recognized as particular challenges for Native Americans living on tribal land. The U.S. Department of Agriculture (USDA) provides nutrition assistance to tribal communities through the Food Distribution Program on Indian Reservations (FDPIR). In 2016, we completed a study of the FDPIR program for USDA's Food and Nutrition Service. This was the first national update since 1990. We found that FDPIR continued to serve people of all ages. However, since 1990, participation by children decreased whereas participation by elders increased. Consistent with the 1990 study, we found that FDPIR households are a very low‐income population. Households reported significantly higher rates of food insecurity than national averages—34% experienced low food security, and about 22% experienced very low food security. Changing demographics call for continued attention to the diverse nutritional needs of young and elderly program participants in tribal communities. Although barriers to food access persist in Indian country, FDPIR and locally sourced food initiatives help to meet needs. Nutrition and wellness education addresses health disparities and fosters healthy lifestyles. Partnerships operating at multiple levels support food production and distribution, improve access to healthy foods, and encourage healthy diets. From a policy and practice perspective, the study findings offer insights for tribal communities and rural areas that have limited access to healthy food options and illustrate how nutrition assistance programs can coexist with local initiatives to provide practical approaches to ensure healthy and adequate nutritional support.
Critical review of the management of primary central nervous nongerminomatous germ cell tumors
Authors: Abu Arja Mohammad H. , Bouffet Eric , Finlay Jonathan L. , AbdelBaki Mohamed S.
Published: February 2019

Multimodal strategies have significantly improved the outcomes for patients with central nervous system nongerminomatous germ cell tumors. Two large cooperative group studies have recently reported much improved outcomes compared with historical series. However, a substantial proportion of patients still attain inadequate responses to initial chemotherapy prior to irradiation, with adverse impact upon survival; optimal induction chemotherapy regimens and radiotherapy strategies are as yet unidentified. Outcomes for patients with relapsed disease remain poor. There is an obvious need to incorporate molecular studies within prospective clinical trials that will likely lead to the incorporation of targeted, more effective future treatment strategies.
Novel reactive thermoplastic resin as a matrix for laminates containing phase change microcapsules
Authors: Fredi Giulia , Dorigato Andrea , Pegoretti Alessandro
Published: February 2019

This work aims at developing multifunctional thermoplastic laminates combining structural and heat storage/management functions. The laminates are constituted by paraffin microcapsules as phase change materials (PCM), continuous carbon fibers, and a novel thermoplastic liquid methyl methacrylate resin (Elium), processable as a thermoset. The characterization aims to study how the paraffin microcapsules influence the thermo‐mechanical properties and thermal management performance of Elium and of the relative composite laminates. For the Elium/PCM systems, the phase change enthalpy increased with the experimental PCM concentration up to 101 J/g, but the mechanical properties decreased concurrently. The melting enthalpy of the laminates also increased with the microcapsule amount, up to 66.8 J/g, which indicates that the mild conditions applied in the processing of the liquid resin allow the integrity of the microcapsules to be preserved. This is also confirmed by the improved thermal management performance observed through thermal camera imaging measurements. Microscopy techniques showed that the PCM phase is preferentially distributed in the interlaminar region, which accounts for the observed decrease in the interlaminar strength and the flexural properties with an increase in the PCM content. These results show a potential for the future development of multifunctional thermoplastic composites with elevated thermal energy storage capabilities. POLYM. COMPOS., 40:3711–3724, 2019. © 2019 Society of Plastics Engineers
Academic socialization, parental educational expectations, and academic self‐efficacy among Latino adolescents
Authors: Cross Fernanda L. , Marchand Aixa D. , Medina Michael , Villafuerte Andrea , Rivas‐Drake Deborah
Published: February 2019

This study examined the direct association between parental educational expectations and adolescents’ academic self‐efficacy, as well as the moderating influence of parental academic socialization messages. Participants were 148 Latino parent–adolescent dyads with the majority of Mexican origin (80.4%). Most of the parent participants were mothers (85.8%). Adolescents were 13 (46%) or 14 (54%) years of age, and 53% identified as female. Adolescents reported their academic self‐efficacy and perceptions of their parents’ educational expectations; parents reported on their academic socialization messages of shame/pressure and effort regarding academics. The results suggest that, after accounting for parents’ level of education and immigrant status, parental educational expectations were positively associated with adolescent academic self‐efficacy. This association was stronger among adolescents whose parents reported transmitting fewer messages of shame/pressure and academic effort. These results point to the importance of nuances in the content and type of academic socialization messages within Latino families.
Young adolescent psychological need profiles: Associations with classroom achievement and well‐being
Authors: Earl Stephen R. , Taylor Ian M. , Meijen Carla , Passfield Louis
Published: February 2019

Drawing on self‐determination theory, a person‐centered methodology was adopted to identify distinct pupil profiles based on their psychological need satisfaction. A sample of 586 pupils (387 male, 199 female; mean age = 12.6, range 11–15 years old) from three secondary schools reported their psychological need satisfaction, and well‐ and ill‐being, with teachers rating pupil achievement. Hierarchical cluster analysis revealed five distinct profiles. Four profiles indicated synergy existed between the three needs, showing similar in‐group levels of satisfaction across the needs but in varying amounts. Univariate and multivariate analyses, controlling for school and taught subject, revealed the satisfied group displayed the highest classroom performance (F4,540 = 7.03; p < 0.001; ηp2 = 0.05), well‐being (F8,1,136 = 45.63; p < 0.001; Wilk's Λ = 0.57; ηp2 = 0.24) and lowest ill‐being (F8,1,134 = 23.39; p < 0.001; Wilk's Λ = 0.74, ηp2 = 0.14), whereas the dissatisfied group displayed the most adverse outcomes. The findings illustrate that the three psychological needs may operate interdependently and should be considered in combination rather than in isolation. The research offers practical insights into why pupils may function differently in classrooms and could inform targeted initiatives towards pupils with psychological need satisfaction deficits.
Electron Density of Polymeric Nanoparticles Determined by Image Processing of Transmission Electron Micrographs: Insights into Heavy Metal Staining Processes
Authors: Reifarth Martin , Müller Walter , Shkodra‐Pula Blerina , Görls Helmar , Schubert Ulrich S. , Heintzmann Rainer , Hoeppener Stephanie
Published: February 2019

A crucial parameter for the investigation of in particular low electron scattering materials by transmission electron microscopy is their ability to attenuate the electron beam and by this to generate appropriate contrast. Surprisingly little attempts have been devoted to at least qualitatively judge on this property of materials. Here an automated imaging analysis algorithm is introduced for the determination of a characteristic electron attenuation factor for homo‐ and (co)polymer nanoparticles which provides a means to access a measure for the contrast in a systematic study of the inherent contrast as well as of the contrast of the nanoparticles after staining procedures. The determination is based on similar imaging conditions for different nanoparticle systems, which enables a comparative approach. Additionally, based on the importance and versatility of osmium tetroxide staining, experiments are conducted elucidating the staining process of model nanoparticle systems bearing olefinic groups. The binding of osmium tetroxide in the environment of the nanoparticle is investigated by means of high‐resolution electrospray mass spectrometry.
Roles of the ClpX IGF loops in ClpP association, dissociation, and protein degradation
Authors: Amor Alvaro J. , Schmitz Karl R. , Baker Tania A. , Sauer Robert T.
Published: February 2019

IGF‐motif loops project from the hexameric ring of ClpX and are required for docking with the self‐compartmentalized ClpP peptidase, which consists of heptameric rings stacked back‐to‐back. Here, we show that ATP or ATPγS support assembly by changing the conformation of the ClpX ring, bringing the IGF loops closer to each other and allowing efficient multivalent contacts with docking clefts on ClpP. In single‐chain ClpX pseudohexamers, deletion of one or two IGF loops modestly slows association with ClpP but strongly accelerates dissociation of ClpXP complexes. We probe how changes in the sequence and length of the IGF loops affect ClpX–ClpP interactions and show that deletion of one or two IGF loops slows ATP‐dependent proteolysis by ClpXP. We also find that ClpXP degradation is less processive when two IGF loops are deleted.
Celastrol attenuates renal injury in diabetic rats via MAPK/NF‐κB pathway
Authors: Zhang Min , Chen Yan , Yang Mei‐ju , Fan Xin‐Rong , Xie Hui , Zhang Ling , Nie Yu‐Song , Yan Miao
Published: February 2019

The purpose of this study was to investigate the renal protective effect of celastrol on diabetic rats. Furthermore, the mechanism of its action was discussed whether it was related to MAPK/NF‐κB signaling pathway. There were a total of 36 rats. Six rats were randomly chosen as the control group. The remaining 30 rats were given 1% streptozotocin intraperitoneal injection (50 mg/kg) and were randomly divided into five groups: the model control group, the low‐dose celastrol group, the high‐dose celastrol group, the Tripterygium wilfordii polyglycosides group, and the MAPK/NF‐κB inhibitor group. After 4 weeks of continuous administration, 24‐hr urine volume, urinary protein, blood urea nitrogen, and serum creatinine content were observed, and hematoxylin–eosin (HE) staining of the kidney and liver were evaluated. p38MAPK was designated by immunohistochemical method, and NF‐κB p65 in renal tissue was detected by western blotting. Our results showed that celastrol could not only reduce contents of creatinine and urea nitrogen in blood but also reduce excretion of urinary protein in diabetic rats, improve renal pathological injury, and down‐regulate the expression of p38MAPK and NF‐κB p65. In conclusion, celastrol could protect kidney of diabetic rats by regulating the signal pathway of MAPK/NF‐κB, inhibiting inflammation and delaying renal injury.
Semiglobal finite‐time synchronization of complex networks with stochastic disturbance via intermittent control
Authors: Jiang Wenlin , Li Liangliang , Tu Zhengwen , Feng Yuming
Published: February 2019

This paper focuses on the problem of semiglobal finite‐time synchronization of stochastic complex networks via an intermittent control strategy. By establishing a finite‐time criterion condition and a novel finite‐time
‐operator differential inequality, combined with convex techniques, some sufficient conditions are obtained to ensure finite‐time synchronization for stochastic complex networks with time delays. An effective controller is given to guarantee inner finite‐time synchronization, especially for a nondelayed dynamic system. This paper provides a simple controller. Finally, a numerical simulation is given to demonstrate the effectiveness of our results.
The influence of riparian vegetation on water quality in a mixed land use river basin
Authors: Chua Evan M. , Wilson Scott P. , Vink Sue , Flint Nicole
Published: February 2019

Worldwide, agricultural activities are associated with environmental impacts including riparian degradation and increased waterway pollution. The Fitzroy Basin of Central Queensland lies within the Brigalow Belt Bioregion, which is currently experiencing the highest rates of tree clearing in Australia driven by grazing activities, and this is likely to increase riparian degradation. Local riparian condition, however, has not been consistently monitored within the Fitzroy Basin, and its relationship with water quality has not been well established. This study assessed riparian condition of waterways in the Fitzroy Basin using two established scoring methods (the Rapid Appraisal of Riparian Condition and the Australian Rivers Assessment System Habitat Assessment) and statistically investigated the relationship between stream water quality and local riparian condition. Twelve sites in six waterways were sampled four times over two years, during ambient (nonflood) conditions. Upstream creeks with poorer riparian condition had elevated dissolved organic carbon (DOC), dissolved manganese, sulfate, and total nitrogen (TN) concentrations. High concentrations of these water quality variables were associated with poor local riparian scores in principal components analysis. Dissolved manganese and sulfate were included in the multiple regression model for riparian scores (r values: 0.83 to 0.86; p < 0.001), and DOC and TN were very significantly negatively correlated with riparian scores (r values: −0.55 to −0.69; p < 0.001). Overall, the results suggest that protecting riparian vegetation in the Fitzroy Basin and restoring degraded riparian zones could aid in improving water quality in waterways within this region.
Aggregation‐Induced Ultraviolet Emission Enhancement and the Electroluminescence Based on New Phenanthrene Derivatives
Authors: Ye Chang‐Qing , Zhou Li‐Wei , Fan Cong‐Bin , Dai Guo‐Liang , Wang Xiao‐Mei , Tao Xu‐Tang , Tang Peng‐Yu , Su Wen‐Ming
Published: February 2019

A series of new fused‐heterocycle phenanthrene derivatives, namely 9‐(o‐benzofuryl)phenanthrene (Compd. 1), 9,10‐bis(o‐benzofuryl)phenanthrene (Compd. 2), 9‐(o‐dibenzofuryl)phenanthrene (Compd. 3) and 9‐(o‐benzothienyl)phenanthrene (Compd. 4) were designed and synthesized in an effort to obtain aggregation‐induced emission enhancement (AIEE) of ultraviolet (UV) light. The results have shown that Compd. 1 and 2 possess the AIEE of UV‐blue light while Compd. 3 presents UV‐AIEE characteristic. However, Compd. 4 is AIEE‐inactive due to sulfur's heavy atom effect. Based on the absorption and fluorescence in both solution and aggregation, it was found that there is no direct correlation of the intramolecular change‐transfer (ICT) and AIEE properties. Associated with the single‐crystal analyses, it was confirmed that the twisted molecular configuration leading to rigid stacking arrangement with larger intermolecular distance is not immediately relevent to AIEE intensity. It was the degree of the restricted intramolecular rotation (DRIR) in the aggregation that shows direct proportional to the AIEE intensity, in the order of Compd. 1 (5.4‐fold increase) > Compd. 3 (3.2‐fold increase) > Compd. 2 (2.6‐fold increase). UV electroluminescence (EL) from organic light‐emitting diode (OLED) consisting of Compd. 3 as emitting layer was firstly reported.
Hydrogenation of Cinnamaldehyde to Hydrocinnamyl Alcohol on Pt/Graphite Catalyst
Authors: Chang Susheng , Meng Sugang , Fu Xianliang , Zhang Sujuan , Zheng Xiuzhen , Chen Shifu
Published: February 2019

Chemoselectivity is a cornerstone of catalysis, permitting the targeted modification of specific functional groups within complex starting materials. Herein, we elucidate key structural and electronic factors in converting cinnamaldehyde to related hydrocinnamyl alcohol over Pt/graphite composites. Pt/graphite composites were prepared by a facile hydrothermal method, and performed excellent catalytic performance and selectivity in cinnamaldehyde conversion. When the ratio of Pt loading reaches 4%, cinnamaldehyde conversion is 97.3%, and the yield of hydrocinnamyl alcohol is 94.6%, with the selectivity high to 97.2%. Besides graphite, other support materials (BN, SiO2, TiO2, Al2O3, activated carbon, graphene and g‐C3N4), are also investigated to probe the reaction mechanism. This work indicates that the chemoselective hydrogenation of cinnamaldehyde over supported Pt catalyst can be flexibly controlled by tuning Pt loading amount and support materials.