bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Crosslinked Structure and Thermal Properties of Polymer Networks Based on Tung Oil and PVA with Different Catalytic Systems
Authors: Jianprasert Apichaya , Monvisade Pathavuth , Yamaguchi Masayuki 
Published: April 2017

SummaryThis work focuses on the effect of different catalytic systems on network structures and thermal properties of the polymer networks from poly(vinyl alcohol) (PVA) and Tung oil. The polymer networks based on Tung oil and PVA using potassium persulfate (KPS) as a thermal catalyst or KPS and sodium thiosulfate as a redox catalyst were performed at 60 °C and 80 °C. FTIR results confirmed that Tung oil could be crosslinked by both catalysts. Moreover, at 60 °C, it can be seen that the crosslinking reaction with the redox catalyst could occur better than with the thermal catalyst. To prove the crosslinking reaction of PVA in the polymer networks, water resistance of the polymer networks was also investigated. It was found that the PVA was successfully crosslinked by thermal catalyst but was not by redox catalyst. Besides, from this result, it could be suggested that, in the redox system, structure of the polymer networks was mainly formed by Tung oil. From DMA results, Tg of PVA with the thermal catalyst is higher than that with the redox catalyst because of the network formation of PVA in thermal catalytic system. While the Tg of Tung oil in the polymer networks with the redox catalyst is higher than that with the thermal catalyst. This is reasonable because the crosslinking reaction of Tung oil with the redox catalyst could easily occur better than with the thermal catalyst. Altogether, crosslink structure of Tung oil exhibited major influence on properties of PVA/Tung oil polymer network.
Unreactive Gel Networks as Versatile Confined Spaces for Enhanced Photoinduced Processes
Authors: Häring Marleen , Abramov Alex , Díaz Díaz David 
Published: April 2017

SummaryGel materials have been recognized as promising confined media to enhance photoinduced reactions of reactants that are physically embedded in the gel network. In particular, stimuli‐responsive supramolecular self‐assembled gels that are unreactive to light irradiation constitute versatile materials to enhance both unimolecular and bimolecular photoinduced processes (in comparison to those carried out in solution) such as dimerization, isomerization and redox reactions, including multistep mechanisms.
A Comparison of How Well Two Different Models of Thermo‐Setting Polymers Predict Their Thermo‐Mechanical Aspects
Authors: Lowe Chris , Taylor Ambrose 
Published: April 2017

SummaryThe output from a molecular model of a polyester melamine thermoset coating, generated using techniques developed for modelling biological systems, that attempts to predict the performance of free films in a tensile test, is compared to empirical results and the out‐put from a phenomenological model. The latter was constructed using standard equations used by engineers to predict the behaviour of polymers under various conditions from a set of parameters measured by Dynamic Mechanical Analysis. Both come close to predicting reality but a more rapid change in intermolecular forces with temperature, for the first model, would help it to achieve more accurate predictions. Associating some of the parameters of the phenomenological model with molecular mass and chain length may help improve the second model.
Bridging Type 2 Diabetes and Alzheimer's Disease: Assembling the Puzzle Pieces in the Quest for the Molecules With Therapeutic and Preventive Potential
Authors: de Matos Ana Marta , de Macedo Maria Paula , Rauter Amélia Pilar 
Published: April 2017

AbstractType 2 diabetes (T2D) and Alzheimer's disease (AD) are two age‐related amyloid diseases that affect millions of people worldwide. Broadly supported by epidemiological data, the higher incidence of AD among type 2 diabetic patients led to the recognition of T2D as a tangible risk factor for the development of AD. Indeed, there is now growing evidence on brain structural and functional abnormalities arising from brain insulin resistance and deficiency, ultimately highlighting the need for new approaches capable of preventing the development of AD in type 2 diabetic patients. This review provides an update on overlapping pathophysiological mechanisms and pathways in T2D and AD, such as amyloidogenic events, oxidative stress, endothelial dysfunction, aberrant enzymatic activity, and even shared genetic background. These events will be presented as puzzle pieces put together, thus establishing potential therapeutic targets for drug discovery and development against T2D and diabetes‐induced cognitive decline—a heavyweight contributor to the increasing incidence of dementia in developed countries. Hoping to pave the way in this direction, we will present some of the most promising and well‐studied drug leads with potential against both pathologies, including their respective bioactivity reports, mechanisms of action, and structure–activity relationships.
Assessment of TRMM data for precipitation measurement in Bangladesh
Authors: Tarek Mehedi Hasan , Hassan Adil , Bhattacharjee Joy , Choudhury Sayedul Hasan , Badruzzaman Abu Borhan Md. 
Published: April 2017

ABSTRACTApplication of the Tropical Rainfall Measuring Mission (TRMM) can be an efficient method for precipitation measurement in Bangladesh. The TRMM was a joint US−Japan space programme used to measure tropical rainfall with spatial and temporal distribution. This study analyses the reliability of TRMM data by comparing them with the rain gauge data of Bangladesh Meteorological Department at 35 different locations. The comparison is made for the data from 1998 to 2010. Extensive analyses were performed on the basis of different temporal scales (daily, monthly, seasonal and yearly). Both datasets were compared for average, peak and total values. The correlation co‐efficient and bias of TRMM rainfall data with respect to rain gauge values were also determined. However, the rainfall products are also compared at the two most extreme elevation stations to observe the influence of station topography (if any). Results show that TRMM rainfall data closely match with rain gauge data for average values on an annual basis, and the correlation co‐efficient is found to be greater than 0.90. However, significant deviation is found for daily peak rainfall values. Again, a seasonal comparison shows that the TRMM data outputs match with station data except during the dry season. The rainfall data at the highest and lowest elevations show that the TRMM data follow a similar trend to the station data but they underestimate the value to some extent, especially during the wet season. Finally, it is inferred that the TRMM data are reliable in estimating the average rainfall in Bangladesh for hydrological analyses of watersheds.
Generative Topographic Mapping of Conformational Space
Authors: Horvath Dragos , Baskin Igor , Marcou Gilles , Varnek Alexandre 
Published: April 2017

AbstractHerein, Generative Topographic Mapping (GTM) was challenged to produce planar projections of the high‐dimensional conformational space of complex molecules (the 1LE1 peptide). GTM is a probability‐based mapping strategy, and its capacity to support property prediction models serves to objectively assess map quality (in terms of regression statistics). The properties to predict were total, non‐bonded and contact energies, surface area and fingerprint darkness. Map building and selection was controlled by a previously introduced evolutionary strategy allowed to choose the best‐suited conformational descriptors, options including classical terms and novel atom‐centric autocorrellograms. The latter condensate interatomic distance patterns into descriptors of rather low dimensionality, yet precise enough to differentiate between close favorable contacts and atom clashes. A subset of 20 K conformers of the 1LE1 peptide, randomly selected from a pool of 2 M geometries (generated by the S4MPLE tool) was employed for map building and cross‐validation of property regression models. The GTM build‐up challenge reached robust three‐fold cross‐validated determination coefficients of Q2=0.7…0.8, for all modeled properties. Mapping of the full 2 M conformer set produced intuitive and information‐rich property landscapes. Functional and folding subspaces appear as well‐separated zones, even though RMSD with respect to the PDB structure was never used as a selection criterion of the maps.
Free‐breathing liver fat quantification using a multiecho 3D stack‐of‐radial technique
Authors: Armstrong Tess , Dregely Isabel , Stemmer Alto , Han Fei , Natsuaki Yutaka , Sung Kyunghyun , Wu Holden H. 
Published: April 2017

PurposeThe diagnostic gold standard for nonalcoholic fatty liver disease is an invasive biopsy. Noninvasive Cartesian MRI fat quantification remains limited to a breath‐hold (BH). In this work, a novel free‐breathing 3D stack‐of‐radial (FB radial) liver fat quantification technique is developed and evaluated in a preliminary study.MethodsPhantoms and healthy subjects (n = 11) were imaged at 3 Tesla. The proton‐density fat fraction (PDFF) determined using FB radial (with and without scan acceleration) was compared to BH single‐voxel MR spectroscopy (SVS) and BH 3D Cartesian MRI using linear regression (correlation coefficient ρ and concordance coefficient ρc) and Bland‐Altman analysis.ResultsIn phantoms, PDFF showed significant correlation (ρ > 0.998, ρc > 0.995) and absolute mean differences < 2.2% between FB radial and BH SVS, as well as significant correlation (ρ > 0.999, ρc > 0.998) and absolute mean differences < 0.6% between FB radial and BH Cartesian. In the liver and abdomen, PDFF showed significant correlation (ρ > 0.986, ρc > 0.985) and absolute mean differences < 1% between FB radial and BH SVS, as well as significant correlation (ρ > 0.996, ρc > 0.995) and absolute mean differences < 0.9% between FB radial and BH Cartesian.ConclusionAccurate 3D liver fat quantification can be performed in 1 to 2 min using a novel FB radial technique. Magn Reson Med 79:370–382, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Frequency response as a surrogate eigenvalue problem in topology optimization
Authors: Andreassen Erik , Ferrari Federico , Sigmund Ole , Diaz Alejandro R. 
Published: April 2017

SummaryThis article discusses the use of frequency response surrogates for eigenvalue optimization problems in topology optimization that may be used to avoid solving the eigenvalue problem. The motivation is to avoid complications that arise from multiple eigenvalues and the computational complexity associated with computation of eigenvalues in very large problems. Copyright © 2017 John Wiley & Sons, Ltd.
Improvement in treatment abandonment in pediatric patients with cancer in Guatemala
Authors: Alvarez Elysia , Seppa Midori , Rivas Silvia , Fuentes Lucia , Valverde Patricia , Antillón‐Klussmann Federico , Castellanos Mauricio , Sweet‐Cordero E. Alejandro , Messacar Kevin , Kurap John , Bustamante Marisol , Howard Scott C. , Efron Bradley , Luna‐Fineman Sandra 
Published: April 2017

AbstractBackgroundTreatment refusal and abandonment are major causes of treatment failure for children with cancer in low‐ and middle‐income countries (LMICs), like Guatemala. This study identified risk factors for and described the intervention that decreased abandonment.MethodsThis was a retrospective study of Guatemalan children (0–18 years) with cancer treated at the Unidad Nacional de Oncología Pediátrica (UNOP), 2001–2008, using the Pediatric Oncology Network Database. Treatment refusal was a failure to begin treatment and treatment abandonment was a lapse of 4 weeks or longer in treatment. The impact of medicina integral, a multidisciplinary psychosocial intervention team at UNOP was evaluated. Cox proportional hazards analysis identified the effect of demographic and clinical factors on abandonment. Kaplan–Meier analysis estimated the survival.ResultsOf 1,789 patients, 21% refused or abandoned treatment. Abandonment decreased from 27% in 2001 to 7% in 2008 following the implementation of medicina integral. Factors associated with increased risk of refusal and abandonment: greater distance to the centre (P < 0.001), younger age (P = 0.017) and earlier year of diagnosis (P < 0.001). Indigenous race/ethnicity (P = 0.002) was associated with increased risk of abandonment alone. Abandonment correlated with decreased overall survival: 0.57 ± 0.02 (survival ± standard error) for those who completed therapy versus 0.06 ± 0.02 for those who abandoned treatment (P < 0.001) at 8.3 years.ConclusionThis study identified distance, age, year of diagnosis and indigenous race/ethnicity as risk factors for abandonment. A multidisciplinary intervention reduced abandonment and can be replicated in other LMICs.
Tailoring polymers through interplay of ligands within precatalysts: 8‐(Nitro/benzhydryl‐arylimino)‐7,7‐dimethyl‐5,6‐dihydroquinolylnickel halides in ethylene polymerization
Authors: Huang Chuanbing , Zeng Yanning , Flisak Zygmunt , Zhao Zhijuan , Liang Tongling , Sun Wen‐Hua 
Published: April 2017

ABSTRACTA series of 8‐(nitro/benzhydryl‐substituted arylimino)‐7,7‐dimethyl‐5,6‐dihydroquinolines and the corresponding nickel halide complexes were synthesized and characterized. Molecular structures of representative nickel complexes were determined by single crystal X‐ray diffraction, showing the dinuclear dimers with distorted square‐pyramidal geometry around the nickel center. The binding energies determined by X‐ray photoelectron spectroscopy (XPS) indicate the effective coordination between the sp2‐nitrogen and nickel atoms as well as the influence of both the halogen ligands and the substituents within dihydroquinolines on the strength of the NiN bond. Ethylene polymerization with the nickel precatalysts in presence of either methylaluminoxane or diethylaluminum chloride was explored in detail. For the complexes containing the nitro substituent within the organic ligand, the catalytic activity is inversely proportional to the electron density around the nickel core determined by XPS; such phenomenon is consistent with the conclusion of the computational study stating that the activity of precatalysts is correlated with the net charge on the metal center. In the polymerization process, unimodal and branched polyethylenes containing vinyl or vinylene groups were obtained. The nickel precatalysts bearing bulky benzhydryl within the organic ligand as well as bromide rather than chloride attached to the nickel atom produce polymers with relatively large amount of vinylene groups. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2071–2083
Dependence of electrical performance on structural organization in polymer field effect transistors
Authors: Bittle Emily G. , Ro Hyun Wook , Snyder Chad R. , Engmann Sebastian , Kline R. Joseph , Zhang Xinran , Jurchescu Oana D. , DeLongchamp Dean M. , Gundlach David J. 
Published: April 2017

ABSTRACTOrganic semiconductors (OSCs) are strong contenders for use in printed, flexible electronics. Although organic electronic materials have been studied for many years, the physics of charge transport is still under investigation. This is in part due to variability resulting from the large variety of molecules that can be synthesized and inconsistency in electrical characterization due to device and processing conditions. Molecular ordering in OSCs is known to alter the charge transport characteristics and attention to long range and short range ordering provides clues as to the nature of transport pathways. Here, we study ordered regioregular poly(3‐hexylthiophene‐2,5‐diyl) films carefully prepared to obtain a set of three samples with incrementally increasing order on identical transistor architectures. Ordering was characterized using a variety of short and long range techniques to probe the coherence and number of crystallites formed during processing, and the correlation between these different measures of order are quantified. We observe three changes in transistor behavior that show a shift from non‐ideal to more textbook‐like characteristics with increasing order: reduction of the contact resistance, shift to field‐independent mobility, and a shift from a diode‐like (S‐shaped) to linear response at low lateral fields. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1063–1074
Theoretical study on the translocation of partially charged polymers through nanopore
Authors: Wu Fan , Yang Xiao , Luo Meng‐Bo 
Published: April 2017

ABSTRACTThe translocation time τ of partially charged polymers through a neutral nanopore is calculated using Fokker–Planck equation with adsorbing–adsorbing boundary conditions. For the polymer with one charged monomer, we find that τ is dependent on the position of the charged monomer and on the magnitude of the driving force f inside the nanopore. When the charge is located at the front half of the polymer chain, τ is larger than that of neutral polymer and increases with f. When the charge is located at the back half, it is smaller than that of the neutral polymer and decreases with increasing f. We have also studied the behavior of a symmetrical polymer with two like charges located symmetrically in the chain and that of an asymmetrical polymer with two unlike charges. Moreover, we have calculated the translocation time for a general condition of polymer with two randomly distributed charges. All results show that τ is dependent on the positions of charges in the polymer chain and on the magnitude of the driving force. The results can be explained qualitatively by the free‐energy landscape of polymer translocation. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1017–1025
Structural rearrangement and stiffening of hydrophobically modified supramolecular hydrogels during thermal annealing
Authors: Wang Chao , Wiener Clinton G. , Yang Yiming , Weiss R. A. , Vogt Bryan D. 
Published: April 2017

ABSTRACTDynamic crosslinks formed by thermoreversible associations provide an energy dissipation mechanism to toughen hydrogels. However, the details of the organization of these crosslinks impact the hydrogel properties through constraints on the network chain conformation. The physical crosslinks generated by hydrophobic association of the 2‐(N‐ethylperfluorooctane‐sulfonamido)ethyl methacrylate (FOSM) groups in a random copolymer ofN,N‐dimethylacrylamide (DMA) and FOSM provide a simple system to investigate how the hydrogel structure (as determined from small angle neutron scattering impacts the mechanical properties of the hydrogel. The initial hydration of the copolymer at 25 °C leads to a kinetically trapped structure with large‐scale heterogeneities. Heating the hydrogel at 60 °C, which is above the glass transition temperature for the FOSM domains, allows the hydrogel structure to rearrange to reduce the density of network defects and the structural heterogeneities. That effectively increases the crosslink density of the network, which stiffens the hydrogel and decreases the swelling at equilibrium at 25 °C. The processing history determines how the hydrophobes aggregate to form the physically crosslinked network, whose structure defines the mechanical properties of these hydrogels. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2017,55, 1036–1044
Robust state estimation for wireless sensor networks with data‐driven communication
Authors: Liu Huabo , Wang Dongqing 
Published: April 2017

SummaryRobust state estimation problem for wireless sensor networks composed of multiple remote sensor nodes and a fusion node is investigated subject to a limitation on the communication rate. An analytical robust fusion estimator based on a data‐driven transmission strategy is derived to save the sensor energy consumption and reduce the network traffic congestion. The conditions guaranteeing the uniform boundedness of estimation errors of the robust fusion estimator are investigated. Numerical simulations are provided to show the effectiveness of the proposed approach. Copyright © 2017 John Wiley & Sons, Ltd.
Facile Large‐Scale Synthesis of Nanoscale Fayalite, α‐Fe2SiO4
Authors: Chang Qiang , Zhang Chenghua , Liu Chengwei , Li Ke , Yun Yifeng , Cheruvathur Ajin V. , Yang Yong , Li Yongwang 
Published: April 2017

AbstractFayalite has been found various applications in many fields. However, it is scarce in Earth's crust. Most of the preparation methods reported earlier are slightly rigorous or complicated and mainly used for preparing large crystal or single crystal fayalite. Because of the potential applications in the field of functional materials and catalysis, nanoscale fayalite would be interesting and attractive. Herein we designed a new method to synthesize nanoscale α‐Fe2SiO4 via a H2‐assisted gas‐solid reaction. We have used three different approaches based on the above method. The highly dispersed precursor, which was prepared by a continuous co‐precipitation method, was heated to a phase‐transition temperature (∼600 °C) under H2 atmosphere to synthesize nanoscale α‐Fe2SiO4. The fayalites were characterized by XAD, XAS and FT‐IR. Comparing with the earlier reported methods, our method largely reduces the reaction temperature, and facilitates large scale synthesis of nanoscale fayalite. It is found that the well distribution of Fe−O and Si−O domains in a nanometer scale plays an important role in the preparation.
Measuring Self‐Association of Pt Complexes by 195Pt NMR
Authors: Suleymanova Alfiya F. , Eltsov Oleg S. , Kozhevnikov Dmitry N. , Lantushenko Anastasia O. , Evstigneev Maxim P. , Kozhevnikov Valery N. 
Published: April 2017

AbstractA highly soluble neutral cyclometallated Pt complex of C N N type was prepared and its self‐aggregation in CDCl3 solution was studied by NMR dilution method. It was shown that 195Pt NMR can be used to quantify aggregation and therefore be potentially applied to many other Pt complexes. Two‐dimensional HMBC 1H‐195Pt technique increases sensitivity of experiment and allowed recording 195Pt chemical shift values at concentration as low as 1 mM and it was observed that opposite to shielding of aromatic protons, Pt nucleus is deshielded upon increase of concentration.
Interorganizational Imitation and Acquisitions of High‐tech Ventures
Authors: Ozmel Umit , Reuer Jeffrey J. , Wu Cheng‐Wei 
Published: April 2017

Research summary: This article shows that there is a positive association between the changes in the number of prior acquisitions or the changes in the prominence of prior acquirers within the focal venture's subfield and the venture's likelihood to be acquired. Results are in line with the existence of frequency‐ and trait‐based imitation in acquisitions targeting tech ventures. More importantly, these positive associations are more pronounced when (a) exogenous technological uncertainty within the venture's subfield increases and (b) there are significant differences between the focal venture's and acquirer's technological resources. Our findings are in accord with the suggestion that uncertainty in the technology domain is an important boundary condition in moderating the extent of imitation in technology acquisitions. We also discuss alternative explanations and implications.Managerial summary: The findings of this article suggest that when deciding whether or not to acquire a technology venture (i.e., startup company in a high‐tech industry), managers infer information by observing other acquisitions in the venture's subfield to make assessments about the underlying value of the potential targets. We also find that receiving some informational cues from previous acquisitions would be more useful when there is high technological uncertainty in the potential target's subfield about which technologies will be dominant, and when the potential acquirer and the tech venture operate in dissimilar technological areas. This article shows that imitation can be one way to deal with decision‐making under uncertainty when making acquisition decisions in high‐tech environments. Copyright © 2017 John Wiley & Sons, Ltd.