bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of hemocompatibility and endothelialization of hybrid poly(vinyl alcohol) (PVA)/gelatin polymer films
Authors: Ino Julia M. , Sju Ervi , Ollivier Véronique , Yim Evelyn K.F. , Letourneur Didier , Le Visage Catherine 
Published: July 2013

AbstractEngineered grafts are still needed for small diameter blood vessels reconstruction. Ideal materials would prevent thrombosis and intimal hyperplasia by displaying hemocompatibility and mechanical properties close to those of native vessels. In this study, poly(vinyl alcohol) (PVA)/gelatin blends were investigated as a potential vascular support scaffold. We modified a chemically crosslinked PVA hydrogel by incorporation of gelatin to improve endothelial cell attachment with a single‐step method. A series of crosslinked PVA/gelatin films with specific ratios set at 100:0, 99:1, 95:5, and 90:10 (w/w) were prepared and their mechanical properties were examined by uniaxial tensile testing. Tubes, obtained from sutured films, were found highly compliant (3.1–4.6%) and exhibited sufficient mechanical strength to sustain hemodynamic strains. PVA‐based hydrogels maintained low level of platelet adhesion and low thrombogenic potential. Endothelial cell adhesion and proliferation were drastically improved on PVA/gelatin films with a feed gelatin content as low as 1% (w/w), leading to the formation of a confluent endothelium. Hydrogels with higher gelatin content did not sustain complete endothelialization because of modifications of the film surface, including phase segregation and formation of microdomains. Thus, PVA/gelatin (99:1, w/w) hydrogels appear as promising materials for the design of endothelialized vascular materials with long‐term patency. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 101B: 1549–1559, 2013.
Bioglass/alginate composite hydrogel beads as cell carriers for bone regeneration
Authors: Zeng Qiongyu , Han Yan , Li Haiyan , Chang Jiang 
Published: July 2013

AbstractCell carrier is a useful biomedical tool to deliver particular kind of cells to a specific site for cell therapy or tissue regeneration. In the current study, 45S5 bioglass (BG) was introduced into alginate (ALG) to generate BG/ALG composite hydrogel beads as cell carriers. The ions releasing behavior, dimensional stability andin vitrobioactivity of the beads were investigated. Results showed that the BG/ALG beads revealed similar calcium ion releasing behavior as compared with ALG beads. In addition, silicon ion releasing was detected in BG/ALG beads. BG/ALG and ALG beads shared similar dimensional stability, and BG/ALG beads could induce apatite deposition on their surface after being soaked in stimulated body fluid. Then, the effects of ion extracts from hydrogel beads on cell behavior were investigated. Results confirmed that extracts of BG/ALG beads could simulate proliferation and osteogenic differentiation of mesenchymal stem cells as well as angiogenesis of endothelial cells. Furthermore, MC3T3‐E1 cells were successfully encapsulated in hydrogel beads. BG/ALG beads enhanced the cell proliferation and stimulated osteogenic differentiation of the encapsulated MC3T3‐E1 cells as compared with ALG beads. Therefore, BG/ALG composite hydrogel beads loaded with bone forming cells may be useful tools for bone regeneration and tissue engineering applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 42–51, 2014.
One‐pot, Green and Efficient Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones or Thiones Catalyzed by Citric Acid
Authors: Ghorbani‐Choghamarani Arash , Taghipour Tahereh , Azadi Gouhar 
Published: July 2013

AbstractOne‐pot three‐component condensation of ethyl acetoacetate, aldehyde and urea or thiourea in refluxing ethanol in the presence of catalytic amounts of citric acid afforded the corresponding 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones in high yields. The catalyst is reusable and can be applied several times without any decrease in product yield.
Fast and Efficient Reductive Amination of Aldehydes by NaBH4/B(OH)3 and NaBH4/Al(OH)3
Authors: Setamdideh Davood , Hasani Samira , Noori Shahla 
Published: July 2013

AbstractReductive amination a variety of aldehydes and anilines to their corresponding secondary amines were carried out with NaBH4/B(OH)3 and NaBH4/Al(OH)3 as new reducing systems in CH3CN at room temperature in high to excellent yields of products (90‐96%).
Observations of transverse Z mode and parametric decay in the solar wind
Authors: Kellogg P. J. , Goetz K. , Monson S. J. , Opitz A. 
Published: July 2013

AbstractThe frequency resolution of the Time Domain Samplers of the S/WAVES experiments on the STEREO spacecraft has allowed clear observations of the nature of the Langmuir‐Z‐mode waves observed in the solar Wind in conjunction with Type III radio bursts. These include observations of transverse polarization of what are usually identified as Langmuir waves, observations of three‐wave decay, indications of the cause of the broadening of the spectrum of the observed waves, new understanding of the threshold for the three‐wave‐decay instability, and contributions to the understanding of conversion of these waves to electromagnetic waves. Analysis, using the decay relations, shows that decay often occurs to the Z mode, or near it. Z‐mode waves cannot be produced directly by the electrons of Type III bursts. The damping of Z mode and near Z mode is very small, accounting for the common occurrence of this nonlinear process. In particular, three‐wave parametric decay of a Langmuir wave to another Langmuir wave has become recognized as the dominant nonlinear process for Langmuir waves from Type III bursts. It is found, however, that decay usually leaves much of the wave energy in the daughter wave and that this wave often falls in a region where modulational instability must be considered in addition to three‐wave decay. On rare occasions, further decays follow the first. In these cases, the path length of the stimulating electron beam can sometimes be determined.
Influence of mineral fraction on the rheological properties of forsterite + enstatite during grain‐size‐sensitive creep: 2. Deformation experiments
Authors: Tasaka Miki , Hiraga Takehiko , Zimmerman Mark E. 
Published: July 2013

AbstractIn order to understand the effects of secondary minerals on the flow properties of rocks, we have conducted uniaxial compression experiments on polycrystalline forsterite (Fo) + enstatite (En) samples. At constant temperature and strain rate, the flow stress of the samples decreases with increasing enstatite volume fraction ( fEn) for samples with 0 < fEn < 0.5 and increases with increasing fEn for samples with 0.5 < fEn < 1. The values of the preexponential term, stress and grain size exponents, and activation energy in the constitutive equation for a wide range of fEn were determined. Samples with a low fEn(≤0.03) deformed at strain rates of 2 × 10−5 to 2 × 10−4/s exhibit creep characteristics that correspond to dislocation‐accommodated grain boundary sliding creep (i.e., stress exponent, n = 3), whereas diffusion‐accommodated grain boundary sliding creep is typical of high fEn samples (i.e., stress exponent, n = 1). The change of flow strength as a function of fEn during grain‐size‐sensitive creep is primarily due to changes in grain size of both phases and secondarily due to changes in the volume fraction of phases with different flow strengths. Viscosities of all samples can be reproduced in a viscosity model that takes into account (1) the grain sizes estimated by the grain growth laws established in our part 1 paper and (2) flow laws determined for the individual phases, in this case, forsterite and enstatite. Furthermore, we demonstrate that our model can be extended to make predictions of viscosity in other mineral assemblages.
An analysis of diurnal cycles in the mass of ambient aerosols derived from biomass burning and agro‐industry
Authors: Caetano‐Silva L. , Allen A. G. , Lima‐Souza M. , Cardoso A. A. , Campos M. L. A. M. , Nogueira R. F. P. 
Published: July 2013

AbstractStrong diurnal cycles in ambient aerosol mass were observed in a rural region of Southeast Brazil where the trace composition of the lower troposphere is governed mainly by emissions from agro‐industry. An optical particle counter was used to record size‐segregated aerosol number concentrations between 13 May 2010 and 15 March 2011. The data were collected every 10 min and used to calculate aerosol mass concentrations. Aerosol samples were also collected onto filters during daytime (10:00–16:00 local time) and nighttime (20:00–06:00) periods, for subsequent analysis of soluble ions and water‐soluble organic carbon. Biomass burning aerosols predominated during the dry winter, while secondary aerosols were most important in the summer rainy season. In both seasons, diurnal cycles in calculated aerosol mass concentrations were due to the uptake of water by the aerosols and, to a lesser extent, to emissions and secondary aerosol formation. In neither season could the observed mass changes be explained by changes in the depth of the boundary layer. In the summer, nighttime increases in aerosol mass ranged from 2.7‐fold to 81‐fold, depending on particle size, while in the winter, the range was narrower, from 2.2‐fold to 9.5‐fold, supporting the possibility that the presence of particles derived from biomass burning reduced the overall ability of the aerosols to absorb water.
Evaluation of nonscarred myocardial T1 value using contrast‐enhanced look‐locker cardiac MRI and its relationship to cardiac function in dilated cardiomyopathy: Comparison of 1.5 and 3.0 Tesla MRI
Authors: Tachi Masaki , Amano Yasuo , Kobayashi Yasuhiro , Mizuno Kyoichi , Kumita Shinichiro 
Published: July 2013

PurposeTo assess relationship between nonscarred myocardial T1 value measured using contrast‐enhanced Look‐Locker MRI and cardiac function in dilated cardiomyopathy (DCM) at 1.5 Tesla (T) and 3.0T MRI.Materials and MethodsContrast‐enhanced Look‐Locker MRI was performed in 35 DCM patients. Nonscarred myocardial and blood T1 values were calculated from the signal intensity values and the delay time obtained on Look‐Locker MRI. We assessed the correlation between the myocardial T1 value or myocardial T1 minus blood T1 value and cardiac function estimated using cine MRI (e.g., end‐diastolic volume: EDV, left ventricular ejection fraction: LVEF) or brain natriuretic peptide (BNP).ResultsWith 1.5T MRI (n = 16), the myocardial T1 value correlated negatively with the EDV(r = −0.66) and end‐systolic volume (ESV; r = −0.68), and positively with the LVEF (r = 0.51); the myocardial T1 minus blood T1 value correlated inversely with EDV (r = −0.70), ESV (r = −0.62), and brain natriuretic peptide (BNP; r = −0.56). With 3.0T MRI (n = 17), the myocardial T1 value correlated negatively with ESV (r = −0.44), septal thickness (r = −0.60), and BNP (r = −0.51), and positively with LVEF (r = 0.61); the myocardial T1 minus blood T1 value negatively correlated with BNP (r = −0.50) and positively with LVEF (r = 0.54).ConclusionThe nonscarred myocardial T1 value measured with either 1.5T or 3.0T contrast‐enhanced Look‐Locker MRI is significantly related to cardiac dysfunction in DCM. J. Magn. Reson. Imaging 2013;38:1395–1401. © 2013 Wiley Periodicals, Inc.
Prospects ofin ovofeeding and nutrient supplementation for poultry: the science and commercial applications—a review
Authors: Kadam Mukund M , Barekatain Mohammad R , K Bhanja Subrat , Iji Paul A 
Published: July 2013

AbstractIn ovosupplementation of poultry embryos was first reported several decades ago, but it is only recently that concerted research has been directed at developing the technology for this process to be routinely used by the poultry industry. Although the technology ofin ovofeeding was patented more than 10 years ago, it has not been widely adopted by the poultry industry. This review examines the early development of the enteric system of the poultry embryo; defines and distinguishes betweenin ovofeeding andin ovonutrient administration; highlights the importance of early feeding of the chick; and discusses the development ofin ovofeeding technology and its effects on hatchability, growth, gut health and immune response of chicks. The range of possible nutrients that can be administered is also explored. The limitations associated with embryo development and nutrient metabolism are highlighted, leading to the prediction of the future role ofin ovofeeding in the poultry industry. © 2013 Society of Chemical Industry
Managing Organisational Knowledge: A Case Study of a Global Energy Consulting Group
Authors: Skok Walter , Clarke Kevin , Krishnappa Sandeep 
Published: July 2013

ABSTRACTThis paper describes a two‐year project to improve the management of organisational knowledge within a global energy consulting group by reviewing current practice and implementing new working practices, processes and systems.The case study approach adopted is divided into three parts and includes the following: the review of the initial situation, the desired future aims (covering core processes of generation, storage, distribution and application of knowledge) and a comprehensive implementation strategy. The paper outlines the corresponding management of change initiative to promote a new Knowledge Management (KM) programme throughout the organisation and the introduction of new processes, staff responsibilities and roles, knowledge dissemination and sharing, intranet design using SharePoint 2010 and an engagement plan for stakeholder involvement.The findings first confirm the classic success factors for KM projects, such as management buy‐in, stakeholder participation, comprehensive training and need for super users. Second, they highlight the problems associated with standardising business processes across disparate locations where the staff have local customs and knowledge. Finally, the case demonstrates the importance of initially considering information rather than KM issues and explicitly showing potential benefits to individuals. In this way, careful consideration of business, people and technology factors can produce gains at an individual level that can then lead to long term organisational benefits, such as faster and comprehensive proposal preparation, improved client satisfaction and more effective knowledge sharing. The results will be of practical use to organisations undertaking similar global KM initiatives. Copyright © 2013 John Wiley & Sons, Ltd.
Whose experience is measured?: A pilot study of patient satisfaction demographics in pediatric otolaryngology
Authors: Nieman Carrie L. , Benke James R. , Ishman Stacey L. , Smith David F. , Boss Emily F. 
Published: July 2013

Objectives/HypothesisDespite a national emphasis on patient‐centered care and cultural competency, minority and low‐income children continue to experience disparities in health care quality. Patient satisfaction scores are a core quality indicator. The objective of this study was to evaluate race and insurance‐related disparities in parent participation with pediatric otolaryngology satisfaction surveys.Study DesignObservational analysis of patient satisfaction survey respondents from a tertiary pediatric otolaryngology division.MethodsDemographics of survey respondents (Press Ganey Medical Practice Survey©) between January and July 2012 were compared to a clinic comparison group using t test and chi‐square analyses. Multivariate logistic regression analyses were performed to assess likelihood to complete a survey based on race or insurance status.ResultsA total of 130 survey respondents were compared to 1,251 patients in the comparison group. The mean patient age for which the parent survey was completed was 5.7 years (6.1 years for the comparison group, P = 0.18); 59.2% of children were ≤5 years old. Relative to the comparison group, survey respondents were more often white (77.7% vs. 58.1%; P <0.001) and privately insured (84.6% vs. 60.8%; P <0.001). Similarly, after controlling for confounding variables, parents of children who were white (OR 1.8, 95% CI 1.13–2.78, P = 0.013) or privately insured (OR 2.9, 95% CI 1.74–4.85, P <0.001) were most likely to complete a survey.ConclusionMethods to evaluate satisfaction did not capture the racial or socioeconomic patient distribution within this pediatric division. These findings challenge the validity of applying patient satisfaction scores, as currently measured, to indicate health care quality. Future efforts to measure and improve patient experience should be inclusive of a culturally diverse population.Level of Evidence2c. Laryngoscope, 124:290–294, 2014
Kinetics of Dithiobenzoate‐Mediated Methyl Methacrylate Polymerization
Authors: Sidoruk Alana , Buback Michael , Meiser Wibke 
Published: July 2013

AbstractThe equilibrium constant, Keq, of the reversible addition–fragmentation chain transfer (RAFT) model system methyl methacryl dithiobenzoate (MMADB) and of methyl methacrylate (MMA) polymerization mediated by MMADB is studied via electron paramagnetic resonance (EPR) spectroscopy in the range 70 to 110 °C and at −40 °C, respectively. The measured difference in activation energy of the addition and fragmentation steps is: Ea(kad) – Ea(kfrag) ≈ −36.6 kJ mol−1. Significant amounts of “missing step” products from reaction of the cross‐termination product with a methyl methacrylyl radical are found. The fast “missing step” reaction and low Keq, due to slow kad, are responsible for rate retardation being absent in dithiobenzoate‐mediated MMA polymerization.magnified image
Synthesis and Characterization of Ethyl Cellulose Microcapsules Containing Model Active Ingredients
Authors: Pitol‐Filho Luizildo , Kokol Vanja , Voncina Bojana 
Published: July 2013

SummaryPolymers have a wide range of applications, including controlled drug release. In this paper, the methodology to produce microcapsules containing limonene and vanillin as model active ingredients is reported. Polymeric solutions composed by ethyl acetate as solvent, ethyl cellulose as the polymer and an active ingredient were prepared. The microcapsules were produced by dropping the polymeric solution on a coagulation bath, composed by water, sodium dodecyl sulfate, and acetic acid in different concentrations. The variation in concentrations was set to configurate coagulation baths with a wide range of surface tensions. According to the surface tensions, and through Scanning Electron Microscopy (SEM), different structures were observed: spongeous particles, polymeric dense rings or spherical microcapsules. The microparticles obtained had an average diameter of 30 µm. Selected structures were characterized internally by using SEM and Focused Ion Beam (FIB) in a Dual Beam Microscope. The external surface of the spherical particles was mostly dense, with observed nanopores, while micropores were distributed all along the inner structure, probably containing the active ingredient. The artifacts produced during characterization by FIB, as well the thermodynamics of the microcapsules formation are also discussed.
Amphiphilic Block Copolymer Vesicles for Active Wound Dressings: Synthesis of Model Systems and Studies of Encapsulation and Release
Authors: Haas Simon , Chen Yizhou , Fuchs Christian , Handschuh Stephan , Steuber Marc , Schönherr Holger 
Published: July 2013

SummaryPolystyrene‐block‐poly(acrylic acid) (PS‐b‐PAA) diblock copolymers were synthesized via atom transfer radical polymerization (ATRP). Self‐assembly of these block copolymers into polymeric vesicles, so‐called polymersomes, was performed by addition of water to a solution of the block copolymers in tetrahydrofuran (THF). Various antimicrobial compounds and dyes were incorporated in the polymersomes and in addition to the corresponding size distributions, as determined by dynamic light scattering (DLS), the maximum attainable loading concentrations were determined. Using the release of incorporated calcein, which is a pH responsive dye, the principle of a light up probe approach for advanced in situ diagnostics was demonstrated. The release from PS‐b‐PAA vesicles via a vesicle‐to‐micelle transition was triggered by heating a vesicle suspension after addition of the plasticizer THF to 50 °C. Furthermore, a biocompatible and degradable block copolymer system, which contains degradable ester bonds in the main chain, was synthesized and investigated. In particular, poly(ethylene glycol)‐block‐polycaprolactone (PEG‐b‐PCL) copolymers were synthesized via ring‐opening polymerization (ROP). These copolymers were shown to form polymersomes as well and represent a promising family of degradable amphiphilic block copolymers for active wound dressings and related applications.
Synthesis and Characterization of Ethylene/1‐Octene Copolymer Based Ionomer Nanocomposite
Authors: Pradhan Sharmila , Scholtissek Stefanie , Ghimire Ajit , Lach Ralf , Grellmann Wolfgang , Adhikari Rameshwar 
Published: July 2013

SummaryA new type of ionomeric nanocomposite based on elastomeric ethylene/1‐octene copolymer (EOC) and organophilically modified layered silicate was synthesized through sulfonation of the EOC followed by solution casting. The morphology–mechanical properties correlation of the product was studied with the help of scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy and recording microindentation measurement. The nanocomposite with uniformly distributed filler morphology could be conveniently prepared. It was found that the Martens hardness of ionomer nanocomposite comprising 5 wt.‐% layered silicate is approximately threefold of the neat elastomer.
Elevated arteriolar cerebral blood volume in prodromal Huntington's disease
Authors: Hua Jun , Unschuld Paul G. , Margolis Russell L. , van Zijl Peter C. M. , Ross Christopher A. 
Published: July 2013

ABSTRACTBackgroundNeurovascular alterations have been implicated in the pathophysiology of Huntington's disease (HD). Because arterioles are most responsive to metabolic alterations, arteriolar cerebral blood volume (CBVa) is an important indicator of cerebrovascular regulation. The objective of this pilot study was to investigate potential neurovascular (CBVa) abnormality in prodromal‐HD patients and compare it with the widely used imaging marker: brain atrophy.MethodsCBVa and brain volumes were measured with ultra‐high‐field (7.0‐Telsa) magnetic resonance imaging in seven prodromal‐HD patients and nine age‐matched controls.ResultsCortical CBVa was elevated significantly in prodromal‐HD patients compared with controls (relative difference, 38.5%; effect size, 1.48). Significant correlations were found between CBVa in the frontal cortex and genetic measures. By contrast, no significant brain atrophy was detected in the prodromal‐HD patients.ConclusionsCBVa may be abnormal in prodromal‐HD, even before substantial brain atrophy occurs. Further investigation with a larger cohort and longitudinal follow‐up is merited to determine whether CBVa could be used as a potential biomarker for clinical trials. © 2013 Movement Disorder Society
Development of Cyclic Propagation Kinetics for Modeling the Nitroxide‐mediated Radical Copolymerization of Styrene–Divinylbenzene
Authors: Aguiar Leandro G. , Gonçalves Miguel A. D. , Pinto Virgínia D. , Dias Rolando C. S. , Costa Mário Rui P. F. N. , Giudici Reinaldo 
Published: July 2013

AbstractA kinetic model including the cyclic propagation (cyclization) is proposed for the nitroxide‐mediated radical copolymerization of styrene–divinylbenzene. The method involves a balance of sequences of units, which connect a radical center and a pendant double bond present in the same polymer chain. The rate constant for cyclization was considered a function of the sequence length. Good agreement between the model predictions and experimental data for solution and suspension controlled copolymerizations was found. The rate constant of cyclization for the smallest ring (3 monomeric units) was estimated to be 700 s−1 at 90 °C, and the activation energy was estimated to be 32 500 cal mol−1.