bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and quantitation of PVP content in a silicone hydrogel contact lens produced by dual‐phase polymerization processing
Authors: Hoteling Andrew J. , Nichols William F. , Harmon Patricia S. , Conlon Shawn M. , Nuñez Ivan M. , Hoff Joseph W. , Cabarcos Orlando M. , Steffen Robert B. , Hook Daniel J. 
Published: May 2017

AbstractPolyvinylpyrrolidone (PVP) has been incorporated over the years into numerous hydrogel contact lenses as both a primary matrix component and an internal wetting agent to increase lens wettability. In this study, complementary analytical techniques were used to characterize the PVP wetting agent component of senofilcon A and samfilcon A contact lenses, both in terms of chemical composition and amount present. Photo‐differential scanning calorimetry (photo‐DSC), gas chromatography with a flame ionization detector (GC‐FID), and high‐resolution/accurate mass (HR/AM) liquid chromatography‐mass spectrometry (LC‐MS) techniques confirmed dual phase reaction and curing of the samfilcon A silicone hydrogel material. Gel permeation chromatography (GPC) demonstrated that high molecular weight (HMW) polymer was present in isopropanol (IPA) extracts of both lenses. High‐performance liquid chromatography (HPLC) effectively separated hydrophilic PVP from the hydrophobic silicone polymers present in the extracts. Collectively, atmospheric solids analysis probe mass spectrometry (ASAP MS), Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (NMR) spectroscopy, GC‐FID, and LC‐MS analyses of the lens extracts indicated that the majority of NVP is consumed during the second reaction phase of samfilcon A lens polymerization and exists as HMW PVP, similar to the PVP present in senofilcon A. GC‐FID analysis of pyrolyzed samfilcon A and senofilcon A indicates fourfold greater PVP in samfilcon A compared with senofilcon A. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1064–1072, 2018.
Immobilization of lipase B from Candida antarctica on epoxy‐functionalized silica: characterization and improving biocatalytic parameters
Authors: de Souza Stefânia P , de Almeida Rayza AD , Garcia Gabriel G , Leão Raquel AC , Bassut Jonathan , de Souza Rodrigo OMA , Itabaiana Ivaldo 
Published: May 2017

AbstractBACKGROUNDIn this work, lipase B from Candida antarctica (CaLB) was immobilized on Purolite® ECR8205F, Purolite® ECR8214F and Immobead® IB150 P epoxy resins with no modification to their surfaces. Biocatalysts were evaluated for thermal stability and applied in reactions of hydrolysis, esterification and the synthesis of glyceryl carbonate by transesterification with dimethyl‐carbonate both with glycerol and Macauba oil as well as dynamic kinetic resolution of α‐methylbenzylamine, all of them compared with commercial Novozyme 435®.RESULTSProtein desorption of the biocatalysts with Triton X‐100 showed that lipase was immobilized by covalent single‐bond type binding. The immobilization efficiencies were 55.1% for the biocatalyst 8205, 57.1% for 8214, and 14.9 for the 150P, demonstrating the intense effect of surface and material composition on lipase immobilization. The biocatalysts also showed higher initial velocities of esterification and hydrolysis reactions as well as higher thermal stability than Novozyme 435®. On glycerol carbonate synthesis, conversion of 97% and selectivity higher than 99% was demonstrated by enzyme 8214, similar to Novozyme 435®. On kinetic dynamic resolution, conversions higher than 94% and and enantiomeric excesses greater than 90% were also depicted.CONCLUSIONCompared with commercial preparation Novozyme 435®, the novel biocatalysts obtained by immobilization on new epoxy resins demonstrated protein loads about 10‐fold lower and higher specific activity. In all reactions performed, competitive performances were found, demonstrating high potential for industrial applications. © 2017 Society of Chemical Industry
Tourist municipalities and local political corruption
Authors: Jiménez Juan Luis , Nombela Gustavo , Suárez‐Alemán Ancor 
Published: May 2017

AbstractAre tourist municipalities a breeding ground for corruption? Before the 2008 economic crisis, Spain experienced an economic boom, together with a surge in political corruption at the local level. In a tourism‐oriented economy – tourism represents above 11% of country GDP – where most of the tourism activity is focused on certain municipalities, understanding the link between tourism and corruption at the local level is crucial. Whether those municipalities present differences from non‐tourist local governments when it comes to corruption represents the main research question of the present paper. Also, this paper analyzes whether voting behavior in these municipalities hides some particularities related to corrupt activities. This paper gathers information on municipalities' public accounts and fiscal revenues generated by businesses in the local area, together with the results of four local recent elections. Estimations show how tourism contributes to the existence of local political corruption. Interestingly, local governments in tourist municipalities are also proven to be more stable than those in non‐tourist municipalities.
Differences in residents' attitudes towards tourism among mass tourism destinations
Authors: Martínez‐Garcia Esther , Raya Josep Maria , Majó Joaquim 
Published: May 2017

AbstractThis article contributes to extant knowledge by analysing differences in the attitudes towards tourism of residents living in several micro‐destinations (cities) within a larger tourism destination and by using a new approach, the Oaxaca‐Blinder decomposition. Results show that a significant part of the gap in attitudes among cities is explained by residents' perceived tourism impacts; the relevance of each of them in generating gaps is also identified and quantified. However, there is also a significant community adjustment to tourism impacts source of gap, different among cities.
Combined Delivery of a Lipopolysaccharide‐Binding Peptide and the Heme Oxygenase‐1 Gene Using Deoxycholic Acid‐Conjugated Polyethylenimine for the Treatment of Acute Lung Injury
Authors: Kim Ji Yeon , Piao Chunxian , Kim Gyeungyun , Lee Seonyeong , Lee Min Sang , Jeong Ji Hoon , Lee Minhyung 
Published: May 2017

A ternary complex comprising plasmid DNA, lipopolysaccharide‐binding peptide (LBP), and deoxycholic acid‐conjugated polyethylenimine (PEI‐DA) is prepared for combinational therapy of acute lung injury (ALI). The LBP is designed as an anti‐inflammatory peptide based on the lipopolysaccharide (LPS)‐binding domain of HMGB‐1. In vitro cytokine assays show that LBP reduces levels of proinflammatory cytokines by inhibiting LPS. PEI‐DA is synthesized as the gene carrier by conjugation of deoxycholic acid to low‐molecular weight polyethylenimine (2 kDa, PEI2k). PEI‐DA has higher transfection efficiency than high‐molecular weight polyethylenimine (25 kDa, PEI25k). The ternary complex of an HO‐1 plasmid (pHO‐1), PEI‐DA, and LBP is prepared as a combinational system to deliver the therapeutic gene and peptide. The transfection efficiency of the ternary complex is higher than that of the pHO‐1/PEI‐DA binary complex. The ternary complex also reduces TNF‐α secretion in LPS‐activated Raw264.7 macrophage cells. Administration of the ternary complex into the lungs of an animal ALI model by intratracheal injection induces HO‐1 expression and reduces levels of proinflammatory cytokines more efficiently than the pHO‐1/PEI‐DA binary complex or LBP alone. In addition, the ternary complex reduces inflammation in the lungs. Therefore, the pHO‐1/PEI‐DA/LBP ternary complex may be an effective treatment for ALI.
image
Developing Polyamine‐Based Peptide Amphiphiles with Tunable Morphology and Physicochemical Properties
Authors: Samad Mehdi Bin , Chhonker Yashpal Singh , Contreras Jacob I. , McCarthy Alec , McClanahan Megan M. , Murry Daryl J. , Conda‐Sheridan Martin 
Published: May 2017

The ability to tune supramolecular properties such as size, morphology, or metabolic stability is of paramount importance in the field of supramolecular chemistry. Peptide amphiphiles (PAs) are a family of functional self‐assembling biomaterials that have garnered widespread attention due to their broad applicability in medicine. PAs are generally comprised of an amino acid sequence connected to lipid tail(s) allowing them to self‐assemble into supramolecular structures with diverse morphologies. Herein, this study describes the synthesis of a new class of polyamine‐based “hybrid” PAs (PPAs) as novel self‐assembling systems. The described molecules possess diverse polyamine head groups with the goal of tuning physicochemical properties. The findings indicate that small changes in the polyamine head groups result in altered PPA morphologies (nanofibers, micelles, nanoworms). The PPAs present a wide range of physicochemical characteristics, show superior resistance to aggregation, a diverse metabolic profile, and varied assembling kinetics. Most of the PPAs do not show toxicity in the human cells lines evaluated. The PPAs described herein hold promising potential as a safe and nontoxic option for drug delivery, targeting, and tissue engineering applications.
image
Mechanically Robust, Tough, and Self‐Recoverable Hydrogels with Molecularly Engineered Fully Flexible Crosslinking Structure
Authors: Zhou Hongwei , Jin Xilang , Yan Bo , Li Xingjian , Yang Wen , Ma Aijie , Zhang Xiaohui , Li Ping , Ding Xiaobin , Chen Weixing 
Published: May 2017

How to reasonably fabricate polymer network for high performance hydrogels is a critical issue but remains a challenge. This work reports an approach to high performance hydrogels by molecularly engineering fully flexible crosslinking (ffC) network. A model network cross‐linked by fully flexible crosslinking points of triblock copolymer micelles and ionic interactions is fabricated. Due to the unique structure, the resulting ffC hydrogels are mechanically robust, tough, and self‐recoverable. For as‐prepared ffC hydrogels, a tensile stress more than 3.5 MPa can be achieved and the energy dissipation can reach up to 6.61 MJ m−3 at the tensile strain of 125%. Moreover, ffC hydrogels fabricated under constant strain can achieve an energy dissipation ability up to 11.63 MJ m−3 at the tensile strain of 100% and a tensile stress of 17.57 MPa. Based on these results, a dynamic molecular mechanism in the ffC hydrogel network under tensile deformation is proposed. The high performances of the ffC hydrogels can be possibly attributed to the sequential breakage and energy dissipation of the flexible crosslinking points and the easily accessible polymer chain orientation during tensile deformation.
image
End Functionalized Nonionic Water‐Dispersible Conjugated Polymers
Authors: Zhan Ruoyu , Liu Bin 
Published: May 2017

2,7‐Dibromofluorene monomers carrying two or four oligo(ethylene glycol) (OEG) side chains are synthesized. Heck coupling between the monomers and 1,4‐divinylbenzene followed by end capping with [4‐(4‐bromophenoxy)butyl]carbamic acid tert‐butyl ester leads to two nonionic water‐dispersible poly(fluorene‐alt‐1,4‐divinylenephenylene)s end‐functionalized with amine groups after hydrolysis. In water, the polymer with a lower OEG density (P1) has poor water dispersibility with a quantum yield of 0.24, while the polymer with a higher OEG density (P2) possesses excellent water‐dispersibility with a high quantum yield of 0.45. Both polymers show fluorescence enhancement and blue‐shifted absorption and emission maxima in the presence of surfactant sodium dodecyl sulfate and dodecyltrimethylammonium bromide. The polymers are also resistant to ionic strength with minimal nonspecific interactions to bovine serum albumin. When biotin is incorporated into the end of the polymer backbones through N‐hydroxysuccinimide/amine coupling reaction, the biotinylated polymers interact specifically with streptavidin on solid surface.
image
Magnetic resonance electrical properties tomography for small anomalies using boundary conditions: A simulation study
Authors: Lee Joonsung , Choi Narae , Seo Jin Keun , Kim Dong‐Hyun 
Published: May 2017

PurposeMagnetic resonance electrical property tomography (MREPT) is an emerging imaging modality using measured B1 maps from magnetic resonance imaging (MRI) to measure a distribution of electric conductivity and permittivity of the subject at the Larmor frequency. Conventional MREPT approaches at single transmit channel system using the Helmholtz equation rely on an assumption that conductivity and permittivity of the subject are locally homogeneous. For small tissue structures and tissue boundaries, in which the assumption of locally homogeneous conductivity and permittivity does not hold, the reconstructed conductivity values deviated from the actual values, so called “Boundary Artifacts.” The aim of this study is to propose new reconstruction processes based on time‐harmonic Maxwell's equations to reconstruct conductivity for small tissue structures and tissue boundaries.MethodsInstead of removing the electric fields from the equations as done in the Helmholtz equation, three key identities of circularly polarized and longitudinal components of electric fields, circularly polarized component of magnetic fields, and electric properties from time‐harmonic Maxwell's equations are derived. Based on the three key identities, the proposed reconstruction methods determine conductivity, permittivity, and circularly polarized component and longitudinal component of electric fields using the measured H1+. In each iterative step, estimated conductivity, permittivity, electric fields, and artifact‐free mask region, Ω, where the contribution of the boundary artifacts is small, were updated. Using the estimated values in the artifact‐free mask region as boundary conditions, the estimates beyond the mask region were updated. EM simulations were performed on three types of numerical phantoms with very small regions of homogeneous conductivity and permittivity. The performance of the proposed methods was evaluated using the simulated electric and magnetic fields.ResultsFor the numerical simulation model, the proposed methods significantly reduced the boundary artifacts compared to conventional methods using Helmholtz equations. In addition, previous methods using the Helmholtz equation could measure conductivity of only large anomalies, but the proposed method can measure the conductivity of the small compartments whose size is 2–3 voxels. The proposed approaches are compatible with spatial filtering which can be used to reduce noise. If a good image segmentation is available as a prior information, better initial boundary conditions can be estimated, and thus the proposed approach can be more accurate for small tissue structures.ConclusionsThe proposed reconstruction method not only determines electrical properties, but also circularly polarized component and longitudinal component of electric fields using an iterative process. The proposed method can quantitatively detect the conductivity of the small anomalies better than conventional methods.
Propylene Polymerization Reactor Control and Estimation Using a Particle Filter and Neural Network
Authors: Dias Ana Carolina Spindola Rangel , da Silva Wellington Betencurte , Dutra Julio Cesar Sampaio 
Published: May 2017

AbstractPolymeric materials are present in various industrial sectors and in daily life, presenting advantages such as low cost and durability. Several processes for manufacturing have been developed. To achieve safety and operational goals measurement methods for proper process monitoring and effective control are needed. However, in real polymer plants, measuring devices are subject to uncertainties and are not always available. Hence, this paper proposes a virtual sensor scheme based on a particle filter and artificial neural network (ANN) that is applied to a simulated polymerization reactor. This scheme reduces uncertainties and enables the observation of latent variables. The ANN is also used for predicting the final properties of the polymer. The goal is to provide controllers with more complete and improved information. The results show that the virtual sensor scheme improves the process control, providing accurate estimates and action times that are consistent with industrial sampling intervals, which highlights its potential for practical applications.
image
Effect of electromyographic biofeedback as an add‐on to pelvic floor muscle exercises on neuromuscular outcomes and quality of life in postmenopausal women with stress urinary incontinence: A randomized controlled trial
Authors: Bertotto Adriane , Schvartzman Renata , Uchôa Silvana , Wender Maria Celeste Osório 
Published: May 2017

AimsTo compare the efficacy of pelvic floor muscle exercises (PFME) with and without electromyographic biofeedback (BF) in increasing muscle strength, improving myoelectric activity, and improving pre‐contraction and quality of life in postmenopausal women with stress urinary incontinence.MethodsRandomized controlled trial of 49 postmenopausal women with stress urinary incontinence. Participants were allocated across three groups: control, PFME alone, and PFME + BF. Forty‐five women completed the study (14 control, 15 PFME, 16 PFME + BF; mean age 58.26 years). Outcome assessment was carried out using digital palpation (modified Oxford grading scale), electromyography, and the International Consultation Incontinence Questionnaire‐Short Form (ICIQ‐SF) quality of life instrument. The treatment protocol consisted of eight twice‐weekly, 20‐min one‐on‐one sessions. Controls were assessed only at baseline and after 1 month.ResultsThe PFME and PFME + BF groups exhibited significant increases in muscle strength (Oxford scale) (P < 0.0001), precontraction while coughing (P < 0.0001), maximum voluntary contraction, duration of endurance contraction, and ICIQ‐SF scores (P < 0.0001). PFME + BF was associated with significantly superior improvement of muscle strength, precontraction while coughing, maximum voluntary contraction, and duration of endurance contraction as compared to PFME alone (P < 0.05).ConclusionsThis preliminary study suggests that pelvic floor muscle training, with and without biofeedback, is associated with increased muscle strength, myoelectric activity, precontraction of pelvic floor muscles, and improved quality of life in postmenopausal women with stress urinary incontinence.
Simple cylindrical and spherical finite elements
Authors: Heyliger Paul R. 
Published: May 2017

SummaryFinite element approximations are developed for three‐dimensional domains naturally represented in either cylindrical or spherical coordinates. Lines of constant radius, axial length, or angle are used to represent the domain and cast approximations that are natural for these geometries. As opposed to general isoparametric three‐dimensional elements generated in conventional parent space, these elements can be evaluated analytically and do not generate geometric discretization error. They also allow for anisotropic material coefficients that are frequently aligned in either cylindrical or spherical coordinates. Several examples are provided that show convergence properties and comparison with analytical solutions of the Poisson equation.
Dosing anticancer drugs in infants: Current approach and recommendations from the Children's Oncology Group's Chemotherapy Standardization Task Force
Authors: Balis Frank M. , Womer Richard B. , Berg Stacey , Winick Naomi , Adamson Peter C. , Fox Elizabeth ,   for the Children's Oncology Group Chemotherapy Standardization Task Force
Published: May 2017

AbstractAn analysis of dose modifications for infants in 29 Children's Oncology Group protocols across 10 cancer types revealed 11 sets of criteria defining the infant population using age, weight, body surface area (BSA), or a combination of these parameters and eight dose modification methods. A new method of dosing anticancer drugs in infants was developed based on the rationale that prior modifications were implemented to reduce toxicity, which is not cancer‐specific. The new method uses BSA dose banding in dosing tables for infants and children with a BSA <0.6 m2 and gradually transitions from body weight based to BSA‐based dosing.
No improvement in clinical trial enrollment for adolescents and young adults with cancer at a children's hospital
Authors: Jacob Seethal A. , Shaw Peter H. 
Published: May 2017

AbstractBackgroundWe have previously published data from 2001 to 2006 showing that adolescent and young adult (AYA) oncology patients have significantly lower therapeutic clinical trial enrollment rates than younger patients. Our objective was to determine if the enrollment of AYA patients on therapeutic studies at the same institution has improved in recent years with the greater focus on this population locally and nationally.MethodsWe retrospectively analyzed cancer registry data at the Children's Hospital of Pittsburgh (CHP) for all new oncologic diagnoses between January 2010 and December 2014. These data included age, gender, diagnosis, race and whether the patient was enrolled on an open treatment study. Univariate analyses were carried out to compare demographic data between AYA patients (aged 15–22) who enrolled on study and those who did not.ResultsEight hundred sixty‐five new oncology patients were seen at CHP during this time, 23% of whom were 15 years or older; 33% of all patients were treated on a clinical trial, including 34% of younger patients and 24% of older patients (P = 0.0017). The differences between these rates and those from prior years in both age groups (38% and 27%, respectively) were not statistically significant (P = 0.15, 0.53). The most common reason for the low enrollment rates was again the lack of an open therapeutic trial.ConclusionDespite initiatives at CHP and on the national level to enroll more AYA patients on clinical trials, our most recent data show no improvement. This is a potentially remediable factor that needs to continue to be prioritized nationally.
The effect of a p‐phenylen‐bis‐maleamic acid grafted atactic polypropylene interfacial agent on the dynamic‐mechanical properties of iPP/Mica composites measured at the polymer transitions
Authors: García‐Martínez Jesús‐María , Collar Emilia P. 
Published: May 2017

This work deals with the study of the evolution (with temperature) of the in‐phase (E′) and the out‐of‐phase (E″) moduli of polypropylene/mica composites with improved interfacial interactions by the presence of an industrial waste based interfacial modifier named as p‐phenylen‐bis‐maleamic (pPBMA) acid grafted atactic polypropylene (aPP–pPBMA). This additive contains 15% w/w grafted pPBMA (5.0·10−4 g mol−1) obtained from polymer industrial wastes in the Polymer Engineering Group (GIP) labs. The purpose of the work is twofold. One, dynamic mechanical analysis (DMA) has been used to evidence the improvement in properties due to the interfacial modifications by the addition of the novel interfacial modifier (aPP–pPBMA). And two, to obtain a mathematical model to predict the DMA moduli of the composite at α and β transition temperatures. So, a Box–Wilson experimental design considering the amount of mica particles and of interfacial agent as independent variables, and the modulus as the dependent ones at each transition was used. Thus, the final purpose of the work is obtaining forecasts for the DMA parameters as a function of the composite components and of the type of temperature dependent relaxation phenomena taking place. POLYM. ENG. SCI., 57:746–755, 2017. © 2017 Society of Plastics Engineers