bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of chitosan/silk fibroin/hydroxyapatite porous scaffold and its characteristics in comparison to bi‐component scaffolds
Authors: Qi Xiao‐Ni , Mou Zhao‐Li , Zhang Jing , Zhang Zhi‐Qi 
Published: March 2013

AbstractComposite porous scaffolds have attracted extensive attention in the biomedical material field. The aim of this research was to prepare a novel tri‐component composite porous scaffold and to evaluate its relevant properties. The porous scaffold was composed of chitosan (CS), silk fibroin (SF), and nanohydroxyapatite particles (nHA), which we named CS/SF/nHA scaffold and prepared via salt fractionation method combined with lyophilization. The porous structure was achieved using a porogen (salt), and the pore size was controlled by the size of porogen. To evaluate the characteristics of the tri‐component scaffold, three bi‐component scaffolds, CS/SF, CS/nHA, and SF/nHA, were simultaneously prepared for comparison. The scaffolds were subjected to morphological, micro‐structural, and biodegradation analyses. Results demonstrated that all of the scaffolds had pore sizes of 100–300 μm and a porosity of 90.5–96.1%. The biodegradation characteristics of all scaffolds meet the requirements of good biomedical materials. The investigation of the mechanical properties showed that the tri‐component scaffold has better properties than the bi‐component scaffolds. The in vitro biocompatibility with osteoblast‐like MG‐63 cells showed that all the scaffolds are suitable for cell attachment and proliferation; however, the CS/SF/nHA composite porous scaffold is much more effective than the others. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 366–372, 2014.
Enhanced bioactivity and osteoconductivity of hydroxyapatite through chloride substitution
Authors: Cho Jung Sang , Yoo Dong Su , Chung Yong‐Chae , Rhee Sang‐Hoon 
Published: March 2013

AbstractThe effect of chloride‐substitution on bioactivity and osteoconductivity of hydroxyapatite (OHAp) was newly investigated. Chloride‐substituted hydroxyapatites (ClAp) with low and high chloride concentrations were synthesized by reacting Ca(OH)2 and H3PO4 with NH4Cl of low and high concentrations, with subsequent sintering. As a control, pure OHAp was prepared under the same conditions but without addition of NH4Cl. The ClAp showed markedly enhanced bioactivity in simulated body fluid (SBF) as the chloride substitution was increased. In contrast, OHAp did not show any bioactivity at all within the testing period. The solubility tests in deionized water also showed that the higher the chloride‐substituting amount, the higher the dissolution amounts of the constituent elements of apatite, which directly affect bioactivity by increasing the degree of supersaturation of apatite in SBF. In addition, ClAp also showed noticeably higher osteoconductivity within the 4 weeks of implantation in calvarial defects of New Zealand white rabbits, compared with that of OHAp. The total system energy of the apatite calculated by the ab initio method showed that the higher the chloride‐substituting amount, the higher the total system energy, which suggests that the ClAp was energetically less stable compared with OHAp. This result demonstrates the higher solubility of ClAp over that of OHAp in SBF and deionized water. The improved solubility of the OHAp enhances its bioactivity and consequent osteoconductivity. Taken together, it can be concluded that ClAp has encouraging potential for use as a bone grafting material due to its highly enhanced bioactivity and osteoconductivity compared with pure OHAp. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 455–469, 2014.
Dual antibacterial agents of nano‐silver and 12‐methacryloyloxydodecylpyridinium bromide in dental adhesive to inhibit caries
Authors: Zhang Ke , Li Fang , Imazato Satoshi , Cheng Lei , Liu Huaibing , Arola Dwayne D. , Bai Yuxing , Xu Hockin H. K. 
Published: March 2013

AbstractDental resins containing 12‐methacryloyloxydodecylpyridinium bromide (MDPB) showed potent antibacterial functions. Recent studies developed antibacterial resins containing nanoparticles of silver (NAg). The objectives of this study were to develop an adhesive containing dual agents of MDPB and NAg for the first time and to investigate the combined effects of antibacterial adhesive and primer on biofilm viability, metabolic activity, lactic acid, dentin bond strength, and fibroblast cytotoxicity. MDPB and NAg were incorporated into Scotchbond Multi‐Purpose (SBMP) adhesive “A” and primer “P”. Five systems were tested: SBMP adhesive A; A + MDPB; A+NAg; A + MDPB + NAg; P + MDPB + NAg together with A + MDPB + NAg. Dental plaque microcosm biofilms were cultured using mixed saliva from 10 donors. Metabolic activity, colony‐forming units, and lactic acid production of biofilms were investigated. Human fibroblast cytotoxicity of bonding agents was determined. MDPB + NAg in adhesive/primer did not compromise dentin bond strength (p > 0.1). MDPB or NAg alone in adhesive substantially reduced the biofilm activities. Dual agents MDPB + NAg in adhesive significantly reduced the biofilm viability compared with each agent alone (p < 0.05). The greatest inhibition of biofilms was achieved when both adhesive and primer contained MDPB + NAg. Fibroblast viability of groups with dual antibacterial agents was similar to control using culture medium without resin eluents (p > 0.1). In conclusion, this study showed for the first time that the antibacterial potency of MDPB adhesive could be substantially enhanced via NAg. Adding MDPB + NAg into both primer and adhesive achieved the strongest antibiofilm efficacy. The dual agent (MDPB + NAg) method could have wide applicability to other adhesives, sealants, cements, and composites to inhibit biofilms and caries. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
In vitro biological response of plasma electrolytically oxidized and plasma‐sprayed hydroxyapatite coatings on Ti–6Al–4V alloy
Authors: Yeung Wing Kiu , Reilly Gwendolen C. , Matthews Allan , Yerokhin Aleksey 
Published: March 2013

AbstractPlasma electrolytic oxidation (PEO) is a relatively new surface modification process that may be used as an alternative to plasma spraying methods to confer bioactivity to Ti alloy implants. The aim of this study was to compare physical, chemical and biological surface characteristics of two coatings applied by PEO processes, containing different calcium phosphate (CaP) and titanium dioxide phases, with a plasma‐sprayed hydroxyapatite (HA) coating. Coating characteristics were examined by X‐ray diffraction, energy dispersive X‐ray spectroscopy, scanning electron microscopy, surface profilometry, and wettability tests. The biological properties were determined using the human osteoblastic cell line MG‐63 to assess cell viability, calcium and collagen synthesis. The tests showed that PEO coatings are significantly more hydrophilic (6%) and have 78% lower surface roughness (Ra) than the plasma‐sprayed coatings. Cell behavior was demonstrated to be strongly dependent on the phase composition and surface distribution of elements in the PEO coating. MG‐63 viability for the TiO2‐based PEO coating containing amorphous CaPs was significantly lower than that for the PEO coating containing crystalline HA and the plasma‐sprayed coating. However, collagen synthesis on both the CaP and the TiO2 PEO coatings was significantly higher (92% and 71%, respectively) than on the plasma‐sprayed coating after 14 days. PEO has been demonstrated to be a promising method for coating of orthopedic implant surfaces. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.
Novel albendazole–chitosan nanoparticles for intestinal absorption enhancement and hepatic targeting improvement in rats
Authors: Liu Yang , Wang Xiao‐qing , Ren Wei‐xin , Chen Yuan‐lan , Yu Yang , Zhang Jian‐kang , Bawudong Dilimulati , Gu Jun‐peng , Xu Xiao‐dong , Zhang Xue‐nong 
Published: March 2013

AbstractTo improve the treatment of helminthiasis, filariasis, and colorectal cancer, albendazole‐associated chitosan nanoparticles (ABZ‐CS‐NPs) were prepared using the emulsion crosslinking volatile technique with contained sodium tripolyphosphate as the crosslinking agent and Poloxamer 188 as the auxiliary solvent. The structural characteristics of the NPs were determined using X‐ray diffraction to analyze the interaction between CS and the drug. The NPs were then evaluated in terms of their physicochemical characteristics, drug release behavior, in vivo pharmacokinetic parameters, and biodistribution in animal studies. ABZ‐loaded NPs with a uniformly spherical particle sizes (157.8 ± 2.82 nm) showed efficient drug loading, encapsulated efficiency, and high physical stability. The drug release from ABZ‐CS‐NPs was extended over several periods. Kinetic models were then fitted to determine the release mechanisms. ABZ and its metabolite albendazole sulfoxide (ABZSX) were analyzed in rats with mebendazole as the internal standard using reversed‐phase high‐performance liquid chromatography. Compared with the ABZ suspension groups, the relative bioavailability values of ABZ and ABZSX were 146.05 and 222.15%, respectively. In addition, the plasma concentration versus time curve is consistent with that of the two compartment models in the plasma concentration versus time curve. The results indicate that the ABZ‐loaded NPs are promising novel ABZ candidates for passive diffusion in the treatment of hydatid cysts in the liver via oral administration. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Evaluation of industrial wastes as sources of fertilizer silicon using chemical extractions and plant uptake
Authors: Haynes Richard J. , Belyaeva O. N. , Kingston G. 
Published: March 2013

AbstractSix inorganic industrial‐waste materials (coal fly ash, bauxite‐processing mud, steel slag, two samples of air‐cooled blast furnace [BF] slag, and one sample of water‐cooled BF slag), along with wollastonite, were evaluated as fertilizer‐Si sources. Evaluation was carried out by analyzing total and extractable Si fractions in the materials, by incubating them at two rates with a Si‐deficient soil and measuring potentially available extractable Si and by measuring yield and Si uptake by two successive rice crops grown in the fertilized soils. Of the waste materials used, fly ash had the highest total Si content (29%) but a negligible quantity was present in extractable forms. Steel slag and bauxite‐processing mud had only 5%–7% Si content while BF slags contained 14%–18% Si. All materials, other than fly ash, increased the amount of extractable Si present in the soil. Additions of steel slag and bauxite‐processing mud caused greater increases in Si extractability than the air‐cooled BF slags while water‐cooled BF slag–treated soils contained notably high acid‐extractable Si. Because of the alkaline nature of the materials, and their reaction products, there was a positive relationship between extractable soil Si and soil pH. However, an equilibration experiment using NaSiO3 as the Si source confirmed that Si solubility in the soil decreased with increasing pH. Dry‐matter yields of rice, at the lower rate of Si addition, were increased by all treatments other than fly ash. The higher rates of steel slag and bauxite‐processing mud caused yield depressions. Total Si uptake by rice was increased by all treatments, other than fly ash, and was greater at the higher rate of Si addition. It was concluded that the BF slags are the most effective waste materials as fertilizer‐Si sources and that, in slag‐amended soils, CaCl2 and NH4 acetate are the most reliable soil‐test extractants.
Perspectives on the Regional Economic Value of a Pilgrimage
Authors: Saayman Andrea , Saayman Melville , Gyekye Agyapong 
Published: March 2013

ABSTRACTPilgrimages around the world attract large numbers of followers, often classified as religious tourists. More than a million people attend the annual Easter weekend meeting of The Zion Christian Church in the Limpopo Province of South Africa. It is one of the largest pilgrimages in the world and could be expected to have a significant impact on the regional economy. The aim of this paper is to shed light on the spending behaviour of pilgrims at the gathering and the impact that the event has on the economy of Limpopo – one of the poorest provinces in South Africa. Copyright © 2013 John Wiley & Sons, Ltd.
Experimental and Kinetic Modeling Study of Methanol Ignition and Oxidation at High Pressure
Authors: Aranda V. , Christensen J. M. , Alzueta M. U. , Glarborg P. , Gersen S. , Gao Y. , Marshall P. 
Published: March 2013

ABSTRACTA detailed chemical kinetic model for oxidation of CH3OH at high pressure and intermediate temperatures has been developed and validated experimentally. Ab initio calculations and Rice–Ramsperger–Kassel–Marcus/transition state theory (RRKM/TST) analysis were used to obtain rate coefficients for , , , and . The experiments, involving CH3OH/O2 mixtures diluted in N2, were carried out in a high‐pressure flow reactor at 600–900 K and 20–100 bar, varying the reaction stoichiometry from very lean to fuel‐rich conditions. Under the conditions studied, the onset temperature for methanol oxidation was not dependent on the stoichiometry, whereas increasing pressure shifted the ignition temperature toward lower values. Model predictions of the present experimental results, as well as rapid compression machine data from the literature, were generally satisfactory. The governing reaction pathways have been outlined based on calculations with the kinetic model. Unlike what has been observed for unsaturated hydrocarbons, the oxidation pathways for CH3OH under the investigated conditions were very similar to those prevailing at higher temperatures and lower pressures. At the high pressures, the modeling predictions for onset of reaction were particularly sensitive to the reaction.
Approximate Analytical Expressions for the Steady‐State Concentration of Substrate and Cosubstrate over Amperometric Biosensors for Different Enzyme Kinetics
Authors: Rasi M. , Indira K. , Rajendran L. 
Published: March 2013

ABSTRACTMathematical models of amperometric biosensors at three basic types of enzyme kinetics in nonstationary diffusion conditions are discussed. The models are based on nonstationary diffusion equations containing a linear term related to the first‐order and nonlinear term related to the Michaelis–Menten and ping–pong of the enzymatic reaction mechanism. In this paper, we obtain approximate closed‐form analytical solutions for the nonlinear equations under steady‐state condition by using the homotopy analysis method. Analytical expressions for concentrations of substrate and cosubstrate and corresponding current response have been derived for all possible values of parameters. Furthermore, in this work, the numerical simulation of the problem is also reported using Scilab/MATLAB program. An agreement between analytical and numerical results is noted.
Characterization and Minimization of Block Copolypeptide Vesicle Cytotoxicity Using Different Hydrophobic Chain Lengths
Authors: Choe Uh‐Joo , Rodriguez April R. , Li Zhibo , Boyarskiy Sergey , Deming Timothy J. , Kamei Daniel T. 
Published: March 2013

AbstractThe previously reported amphiphilic block copolypeptide, poly(l‐lysine)60‐block‐poly(l‐leucine)20 (K60L20), is able to form vesicles that can be manipulated to different sizes and be prepared in large quantities. This study expands upon that work by varying the length of the hydrophobic segment to optimize the vesicles so that they are monodisperse and low in toxicity. Copolypeptides with longer oligoleucine segments are found to have fewer toxic micelles, small aggregates, and unstable vesicles, and exhibit lower toxicity than vesicles formed from copolypeptides with shorter hydrophobic domains. Oligoleucine segments that are too long, however, result in rigid hydrophobic membranes that prevent the vesicular assemblies from being extruded into a monodisperse population of nanoscale vesicles.
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Efficient numerical tool for the analysis and design of reflectarrays based on cells with three parallel dipoles
Authors: Florencio Rafael , Boix Rafael R. , Carrasco Eduardo , Encinar José A. , Losada Vicente 
Published: March 2013

AbstractIn this article, the Method of Moments in the spectral domain (MoM‐SD) is applied to the analysis of multilayered periodic structures, containing three coplanar parallel dipoles in the unit cell. It is shown that the use of basis functions with edge singularities in the modeling of the current density on the dipoles leads to important computer memory and CPU times savings in the analysis of the periodic structures. The MoM‐SD home‐made software is used in the analysis of a shaped beam reflectarray antenna made of cells with three parallel dipoles under the local periodicity assumption. The numerical results obtained for the radiation pattern of the antenna are compared with numerical results provided by the commercial software CST® and with measurements and good agreement is found. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1212–1216, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27533
A power efficient active integrated antenna
Authors: Lee Joungyoung , Wu Chung‐Tse Michael , Itoh Tatsuo 
Published: March 2013

AbstractWe have integrated a microwave oscillator with a zeroth‐order resonance antenna to build an active oscillating antenna using the coplanar waveguide technology. In this design, the antenna is electrically small and the oscillator has an excellent phase noise performance of 92.5 dBc/Hz. Also, 16.11 dBm (40.83 mW) of effective isotropic radiated power is radiated with high direct current to radio frequency efficiency (27.2%), which is much higher than many other active oscillating antenna designs. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1240–1243, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27543
Radar cross section (RCS) statistical characterization using weibull distribution
Authors: Shi Weiqiang , Shi Xiao‐Wei , Xu Le 
Published: March 2013

AbstractRadar target's backscatter varies rapidly because of change in the relative position of each scatterer, body vibration while moving and so on. Weibull distribution is adopted as an inclusive description of the envelope of various targets' backscattering in this paper. Weibull distribution is expressed as a function of two parameters, shape parameter and scale parameter. The parametric meanings are discussed with the distribution curves of different parameter values plotted. The authors find that Weibull distribution with a proper shape parameter can be an impressively good approximation of some existing RCS distribution models. A parameter estimation method is provided. Two examples are shown to illustrate the application of Weibull distribution. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1355–1358, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27557
DC‐bias and oscillation‐amplitude dependent frequency‐tuning characteristics of varactor‐switching dual‐band CMOS VCOs
Authors: Jang Sheng‐Lyang , Jain Sanjeev , Huang Jhin‐Fang , Hsue Ching‐Wen 
Published: March 2013

AbstractThis article studies the bias and oscillation‐amplitude dependent RF tuning property of varactor‐switching dual‐band voltage‐controlled oscillators (VCOs). The dual‐resonance LC‐tank n‐core and p‐core VCOs have been fabricated using 0.18 μm CMOS technology, and they use dual‐resonance LC resonator consisted of a parallel‐tuned LC resonator and a series resonant resonator. The accumulation‐mode MOS varactors are used. The RF circuit parameters such as oscillation frequency, tuning range, and transition frequency between low‐band and high band as a function of varactor bias, supply voltage, and oscillation amplitude are examined experimentally. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1389–1393, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27574
Peripheral Neuropathy: Assessment of Proximal Nerve Integrity By Diffusion Tensor Imaging
Authors: Mathys Christian , Aissa Joel , Zu Hörste Gerd Meyer , Reichelt Dorothea C. , Antoch Gerald , Turowski Bernd , Hartung Hans‐Peter , Sheikh Kazim A. , Lehmann Helmar C. 
Published: March 2013

ABSTRACTIntroduction: We investigated the utility of diffusion tensor imaging (DTI) for detecting neuropathic changes in proximal nerve segments in patients with peripheral neuropathy. Methods: Twenty‐one individuals with (n = 11) and without (n = 10) peripheral neuropathy underwent DTI of a defined sciatic nerve segment. Patients and controls were evaluated by clinical examination and nerve conduction studies at baseline and 6 months after the initial DTI scan. Results: The mean fractional anisotropy (FA) value was significantly lower in sciatic nerves from patients with peripheral neuropathy as compared with controls. Sciatic nerve FA values correlated with clinical disability scores and electrophysiological parameters of axonal damage at baseline and 6 months after MRI scan. Conclusions: DTI‐derived FA values are a sensitive measure to discriminate healthy from functionally impaired human sciatic nerve segments. DTI of proximal nerve segments may be useful for estimating the proximal axonal degeneration burden in patients with peripheral neuropathies. Muscle Nerve 48: 889–896, 2013
High‐order iterative bracketing methods
Authors: Fried Isaac 
Published: March 2013

SUMMARYThis paper presents high‐order, single‐point, iterative methods for the numerical solution of the general non‐linear equilibrium equation. The methods are designed so that the approximations provided by the iterative process alternate about the targeted root, thus providing progressively better upper, as well as lower bounds on the sought root, which is thus numerically bracketed ever tighter. The effectiveness of the proposed methods is demonstrated by applying them to obtain close bounds on the extreme eigenvalues of the finite elements global stiffness matrix of the hanging string. Copyright © 2013 John Wiley & Sons, Ltd.