bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Shanghai case: a qualitative evaluation of community health reform in response to the challenge of population ageing
Authors: Wei Xiaolin , Zakus David , Liang Hong , Sun Xiaoming 
Published: August 2005

AbstractShanghai's health care system is facing a serious challenge of an ageing population, as 14% of its 17 million residents are 65 or older. In 2000, a community health reform was implemented to provide comprehensive and continuous primary care to community residents with a focus on seniors. The study employed the theoretical framework of examining primary care in terms of the constellation of its four unique elements (first contact, comprehensiveness, longitudinality and coordination) and three healthcare components (structure, process and outcome). The study aimed to evaluate the extent to which the reform has achieved its process goals and how the organizational context influenced the level of implementation. In‐depth interviews with 25 health providers, 15 seniors and four community leaders were carried out. The study found that the Shanghai community health reform has improved the structure and process of primary care regarding first contact, comprehensiveness and longitunality. However, the reform is constrained by structural barriers on seniors' financial access to resources and the capacity of primary care providers. The previous organization system also constrains the reform in CHCs financing and administration. The Shanghai case illustrates that a broad societal view has to be taken when analysing health reforms, which requires the involvement of multiple sectors including the government, health providers and health consumers. Copyright © 2005 John Wiley & Sons, Ltd.
In vitro and in vivo analysis of macroporous biodegradable poly(D,L‐lactide‐co‐glycolide) scaffolds containing bioactive glass
Authors: Day Richard M. , Maquet Véronique , Boccaccini Aldo R. , Jérôme Robert , Forbes Alastair 
Published: August 2005

AbstractRecent studies have demonstrated the angiogenic potential of 45S5 Bioglass®. However, it is not known whether the angiogenic properties of Bioglass® remain when the bioactive glass particles are incorporated into polymer composites. The objectives of the current study were to investigate the angiogenic properties of 45S5 Bioglass® particles incorporated into biodegradable polymer composites. In vitro studies demonstrated that fibroblasts cultured on discs consisting of specific quantities of Bioglass® particles mixed into poly(D,L‐lactide‐co‐glycolide) secreted significantly increased quantities of vascular endothelial growth factor. The optimal quantity of Bioglass® particles determined from the in vitro experiments was incorporated into three‐dimensional macroporous poly(D,L‐lactide‐co‐glycolide) foam scaffolds. The foam scaffolds were fabricated using either compression molding or thermally induced phase separation processes. The foams were implanted subcutaneously into mice for periods of up to 6 weeks. Histological assessment was used to determine the area of granulation tissue around the foams, and the number of blood vessels within the granulation tissue was counted. The presence of Bioglass® particles in the foams produced a sustained increase in the area of granulation tissue surrounding the foams. The number of blood vessels surrounding the neat foams was reduced after 2 weeks of implantation; however, compression‐molded foams containing Bioglass® after 4 and 6 weeks of implantation had significantly more blood vessels surrounding the foams compared with foams containing no Bioglass® at the same time points. These results indicate that composite polymer foam scaffolds containing Bioglass® particles retain granulation tissue and blood vessels surrounding the implanted foams. The use of this polymer composite for tissue engineering scaffolds might provide a novel approach for ensuring adequate vascular supply to the implanted device. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Preparation of thermosensitive microgels via suspension polymerization using different temperature protocols
Authors: Zhang Ying , Zhu Wen , Ding Jiandong 
Published: August 2005

AbstractA thermosensitive and biodegradable microgel for protein drug release was synthesized from a thermosensitive macromer via inverse suspension polymerization. Preparation was made under a constant temperature or under variable temperatures. In the latter protocol, dispersion was performed at a low temperature below lower critical solution temperature of the macromer aqueous solution and polymerization was performed at a high temperature above lower critical solution temperature. According to the experiments, the constant‐temperature method was not suitable for preparation of microgels when the macromer concentration was high, because early physical gelation at the preparation temperature seriously influenced formation of dispersed droplets. If the macromer concentration was low, both temperature protocols resulted in spherical hydrogel microparticles, but the properties of the resulting microgels were different to a certain degree. In both cases, the model protein bovine serum albumin was loaded into microgels by a postfabrication encapsulation technique, which takes advantage of the microgels' negative thermosensitivity. The results demonstrate that, in microgel preparation, the variable‐temperature protocol is useful in suspension polymerization of negatively thermosensitive macromers at a wide rage of monomer concentrations. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Controlling Drug Release from Imprinted Hydrogels by Modifying the Characteristics of the Imprinted Cavities
Authors: Hiratani Haruyuki , Mizutani Yuri , Alvarez‐Lorenzo Carmen 
Published: August 2005

AbstractSummary: The aim of this study was to analyse the influence of the template/functional monomer proportion on the achievement of molecularly imprinted hydrogels with cavities with a high enough affinity for the drug to sustain drug release. Imprinted hydrogels were prepared from N,N‐dimethylacrylamide and tris(trimethylsiloxy)sililpropyl methacrylate (DMAA and TRIS; main components), methacrylic acid (MAA; functional monomer), ethylene glycol dimethacrylate (EGDMA; cross‐linker), and timolol (template drug). Photo‐polymerization of the monomer solutions was carried out in poly(propylene) molds (0.3 mm thickness) to obtain contact lens‐like devices. Non‐imprinted control hydrogels were also prepared in the same way but without the addition of timolol. The imprinted hydrogels showed a higher affinity for timolol and a slower release rate than the non‐imprinted hydrogels. The release rate decreased by increasing the MAA/timolol ratio in the gel recipe. Hydrogels prepared with 400 × 10−3 M MAA, 600 × 10−3 M EGDMA, and a timolol/MAA mole ratio of 1:16–1:32 had drug diffusion coefficients two orders of magnitude below those of non‐imprinted hydrogels. The results obtained clearly indicate that the timolol release rate is critically affected by the conditions under which the hydrogels were synthesized. These effects are discussed on the basis of the influence of drug proportion on the conformation of the imprinted cavities.Timolol release profiles, in 0.9% NaCl at 25 °C, from the non‐imprinted and imprinted hydrogels prepared with 0.400 M MAA, 0.600 M EGDMA, and timolol (the ratio of timolol to MMA is as shown). Data are expressed as mean ± S.D. (n = 5).magnified imageTimolol release profiles, in 0.9% NaCl at 25 °C, from the non‐imprinted and imprinted hydrogels prepared with 0.400 M MAA, 0.600 M EGDMA, and timolol (the ratio of timolol to MMA is as shown). Data are expressed as mean ± S.D. (n = 5).
Schematic Models of Molecular Self‐Organization
Authors: Van Workum Kevin , Douglas Jack F. 
Published: August 2005

AbstractMolecular self‐organization is central to the formation of numerous biological structures and the emulation of this process through the creation of synthetic counterparts offers great promise for nanofabrication. Our approach to understanding the principles governing this process is inspired by existing models and measurements on the self‐organization of actin, tubulin and the ubiquitous icosahedral structures of viral capsids. We introduce a family of simple potentials that give rise to the self‐organization of chain‐like, random surface (‘membrane’), tubular (‘nanotube’) and hollow icosahedral structures that are similar in many respects to their biological counterparts.
Polymeric Scaffolds for Cartilage Tissue Engineering
Authors: Li Wan‐Ju , Tuan Rocky S. 
Published: August 2005

AbstractPolymeric scaffolds are three‐dimensional, porous structures that may be used as a vehicle to deliver cells or therapeutic factors to repair tissue defects. Both biodegradable and non‐biodegradable polymers have been developed for this purpose. In this review, we survey the polymers that have been investigated for cartilage tissue engineering and discuss the critical parameters for successful applications in the future.
Poly(vinyl alcohol)‐Amino Acid Hydrogels Fabricated into Tissue Engineering Scaffolds by Colloidal Gas Aphron Technology
Authors: Donaldson Elizabeth , Cuy Janet , Nair Prabha , Ratner Buddy 
Published: August 2005

AbstractA new class of hydrogels made from poly(vinyl alcohol) (PVA) and amino acid was formed into porous tissue engineering scaffolds by the colloidal gas aphron (CGA) method. CGA microfoams are formed using high speed stirring to generate uniform, micrometer scale bubbles. CGAs offer several advantages over conventional scaffold fabrication techniques including room temperature processing, aqueous conditions and utilization of air bubbles to create uniform pores. This technique eliminates the need for toxic solvents and salt templates. In addition, the novel poly(vinyl alcohol) hydrogels are inherently strong, eliminating the need for crosslinkers.
Electrostatically Self‐Assembled Multilayers of Chitosan and Xanthan Studied by Atomic Force Microscopy and Micro‐Interferometry
Authors: Maurstad Gjertrud , Bausch Andreas R. , Sikorski Pawel , Stokke Bjørn T. 
Published: August 2005

AbstractThe thickness and surface morphology of electrostatically self‐assembled films of chitosan and xanthan (persistence length of ∼120nm) have been studied using dual‐wavelength Reflection Interference Contrast Microscopy (DW‐RICM) and tapping mode Atomic Force Microscopy (AFM). The multilayers were prepared at two ionic strengths (5mM and 150mM). When the multilayers were assembled at 150 mM a network like morphology was observed after one bilayer. This structure was found to be of large influence in the further growth of the multilayers, with the same kind of network structure being observed at all number of bilayers. A lack of swelling behaviour, as well as the network structure and the poresize of the network, is suggested to originate from the high chain stiffness of xanthan.
Hydrogel Nanocomposite as a Synthetic Intra‐Ocular Lens Capable of Accommodation
Authors: Ravi Nathan , Aliyar Hyder Ali , Hamilton Paul D. 
Published: August 2005

AbstractA hydrogel nanocomposite was designed, synthesized, and evaluated for use as an auto‐focusing intra‐ocular lens. The hydrogel scaffold was composed of a monomer‐free, thiol that contained polyacrylamide (5%), which was allowed to gel in the presence of nanoparticles at pH 7.4, 25°C. The nanoparticles consisted of a proteo‐mimetic polyacrylamide nanogel (∼42 nm), bovine serum albumin (BSA) (∼6 nm), and hydrophilized silica (∼3 nm). The extent of nanoparticle loading increased with decreasing particle size. The elastic modulus increased with increasing loading of the proteo‐mimetic nanogels and BSA, and it decreased with hydrophilized silica. In this investigation, the hydrogel that contained silica was the most promising class of nanocomposite hydrogels with properties comparable to that of a young porcine lens. A nanocomposite that consisted of 10% hydrogel scaffold and 24% hydrophilized silica (elastic [E] modulus of ∼1.0 kPa and refractive index [RI] of 1.42) was injected into a pre‐evacuated porcine lens capsular bag. The composite lens was evaluated in a custom‐designed four‐arm radial stretcher, and its force‐time spectrum was characterized by time constants of 60 ± 8.9 and 800 ± 32 ms. These results were comparable to a young porcine lens (E Modulus of 1.2 kPa; RI of 1.4105; time constants of 48.3 ± 0.58 and 668 ± 24.6 ms, respectively)
Three‐Dimensional Nanoparticle Arrays Templated by Self‐Assembled Block‐Copolymer Gels
Authors: Pozzo Danilo C. , Walker Lynn M. 
Published: August 2005

AbstractWater‐soluble triblock copolymers (PEO‐PPO‐PEO) are utilized to provide thermoreversible micellar templates for three‐dimensional nanoparticle arrays. The triblock forms a cubic micellar structure with typical dimensions of tens of nanometers. The temperature‐dependent amphiphilic nature of the block copolymers provides increased structure control and allows the use of pre‐made silica and gold nanoparticles as well as globular proteins. Using rheology and small‐angle neutron scattering (SANS), we characterize the influence of the nanoparticles on the local particle structure and on the macroscopic mechanical properties. We are able to incorporate significant quantities of nanoparticles into the block copolymer gel without destroying the ordered structure. Contrast matching SANS demonstrates that some level of the template structure is transferred to the nanoparticles. This study demonstrates the feasibility and potential of using this simple approach to generate novel nanoparticles‐polymer composites.
Probing the Hydrodynamic Behavior of Drug‐Induced Tubulin Rings by Fluorescence Correlation Spectroscopy
Authors: Boukari Hacène , Sackett Dan L. , Nossal Ralph 
Published: August 2005

AbstractWe describe fluorescence correlation spectroscopy measurements of tubulin polymers composed of tubulin and either of two cytotoxic peptides – dolastatin 10 and cryptophycin 1. These peptides inhibit tubulin polymerization into microtubules, a major component of cellular networks, and instead induce the formation of predominantly single‐walled tubulin rings. We determine ratios of the hydrodynamic diameter of dolastatin‐tubulin or cryptophycin‐tubulin polymers to that of tubulin dimers, which are compared with corresponding ratios calculated for two simple models: 1) a circular ring made with N contiguous spherical beads and 2) a circular ring constructed with N non‐spherical monomers, each monomer being represented by 21‐minibeads. We find that the computed ratios from the 21‐minibead representation agree well with the measured ones when N = 28 and N = 16 for dolastatin‐tubulin and cryptophycin‐tubulin ring polymers, respectively. That is, the rings are made with 14 and 8 tubulin dimers, confirming the numbers derived by other techniques. The present results further support the applicability of theories that have been developed for calculating hydrodynamic properties of supramolecular biological structures.
Actin Polymerization in a Thermal Gradient
Authors: Pomerance Andrew , Matthews Jermey , Ferguson Matthew , Urbach Jeffrey S. , Losert Wolfgang 
Published: August 2005

AbstractActin polymerization was studied as a function of temperature and in controlled thermal gradients. In the absence of a thermal gradient, we observe a polymerization transition with a temperature increase of less than 10K, and we verify that microrheology provides a local measure of the polymerized fraction. Both of these results are in good agreement with prior observations. Thermal gradients allow us to generate polymerization gradients. This polymerization gradient induces motion in embedded microspheres that is not seen in control samples.
Controlled Release from and Tissue Response to Physically Bonded Hydrogel Nanoparticle Assembly
Authors: Hu Zhibing , Xia Xiaohu , Marquez Manuel , Weng Hong , Tang Liping 
Published: August 2005

AbstractOur recent work on synthesis and application of thermally gelling nanoparticle dispersions is briefly reviewed here. These nanoparticles consist of interpenetrating polymer networks (IPN) of poly‐acrylic acid (PAAc) and poly(N‐isopropylacrylamide) (PNIPAM). The aqueous IPN nanoparticle dispersions with polymer concentrations above 2.5 wt % underwent an inverse thermoreversible gelation at about 33 °C. Dextran markers of various molecular weights as model macromolecular pseudodrugs were mixed with the IPN nanoparticle dispersion at room temperature. At body temperature, the dispersion became a gel. The dextran release profiles were then measured using UV‐visible spectroscopy. The biocompatibility of this nanoparticle assembly was assessed using an animal implantation model.
Pulsatile Release of Insulin from Layer‐by‐Layer Assembled Microgel Thin Films
Authors: Nolan Christine M. , Serpe Michael J. , Lyon L. Andrew 
Published: August 2005

AbstractWe describe studies concerning the construction and characterization of insulin‐impregnated poly(N‐isopropylacrylamide‐co‐acrylic acid) microgel thin films prepared by Layer‐by‐Layer (LbL) polyelectrolyte assembly. These films can be built up in a highly uniform fashion and display linear buildup dependence even up to 30 layers. Thermoresponsivity of these drug loaded films can be utilized to obtain extended pulsatile release of insulin over many cycles. Continuous thermal pulsing allows solubilization of the embedded peptide and subsequent diffusion through the film layers. The magnitude of release can be tuned based on film thickness. This type of microgel thin film construct proves to be extremely robust and can potentially pulse out constant bursts of peptide for more than one month at a time.
Features of the Morphology of 2‐Hydroxyethyl Acrylate ω‐Polymer
Authors: Rozenberg Boris , Chalykh Anatolii 
Published: August 2005

AbstractΩ‐Polymer of 2‐Hydroxyethyl acrylate (HEA) with nanoporous morphology is formed and characterized. Some kinetic peculiarities and mechanism of HEA low‐temperature ω‐polymerization is discussed. It is suggested to use ω‐polymerization of vinyl monomers for preparation of functionalized nanoporous polymer composites for different .technical and biomedical applications.
Design of a planar half‐circle‐shaped UWB notch antenna
Authors: Lee Hyo K. , Park Jong K. , Lee Jung N. 
Published: August 2005

AbstractIn this paper, we propose a small, lightweight, and low‐cost ultra‐wideband (UWB) antenna that exhibits a notch characteristic in the 5‐GHz WLAN band (5.15–5.825 GHz) using a planar half‐circle shape patch, a two‐step matching stub, a coplanar waveguide (CPW)‐type feed, and a hat‐shaped slot. The notch frequency of the proposed antenna can be adjusted by controlling the slot length. The measured results are in reasonably good agreement with the simulated results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 9–11, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21065
Loaded frequency selective surface
Authors: Gao Qiang , Yan Dun‐Bao , Fu Yun‐Qi , Yuan Nai‐Chang 
Published: August 2005

AbstractIn this paper a new frequency‐selective surface (FSS) with loadings, is introduced and analyzed using period moments methods. The simulated results show that FSS may operate in different bands and especially generate a large reduction in the resonant frequency for a fixed unit‐cell size through different loadings. This provides a new orientation for FSS development. Practical circuits are fabricated, and the measured results basically agree well with the simulated ones. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 47–49, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21077
Modeling of lossy multiregion substrates in microelectronic circuits using time‐domain surface integral equations
Authors: Yang Chuanyi , Jandhyala Vikram 
Published: August 2005

AbstractIn this work, the electromagnetic modeling of multiregion, finite‐sized lossy substrates in microelectronic circuits is carried out utilizing time‐domain surface integral equations. To reduce the additional computational complexity in the implementation caused by the decaying “wake” of the Green's function in lossy media, the resulting temporal convolution is addressed by the creation and use of an a priori exponential fitting table for discrete distances through Prony's method. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 68–73, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21084
Doppler effects in a left‐handed material: A first‐principles theoretical study
Authors: Xiao Sanshui , Qiu Min 
Published: August 2005

AbstractThe Doppler effects for the reflected wave from moving media are systemically analyzed in this paper. The theoretical formula for the Doppler shift in left‐handed material, which is described by Drude's dispersion model, is presented. This formula is examined by first‐principles numerical experiments, which are in agreement with the theoretical results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 76–79, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21086
Multidomain pseudospectral time‐domain method for computation of electromagnetic scattering by bodies of revolution
Authors: Shi Yan , Su Tao , Liang Chang‐Hong 
Published: August 2005

AbstractWe present a multidomain pseudospectral method using cylindrical and spherical coordinates for the accurate and efficient time‐domain computation of scattering by bodies of revolution (BOR). In the BOR formulation of Maxwell's equations, the Fourier collocation method is utilized in the azimuthal direction and the Chebyshev collocation method in the other directions. Using the complex‐coordinate‐stretching approach, the strongly well‐posed perfectly matched layer (PML) formulations are derived in cylindrical and spherical coordinates. A comparison of the results obtained using the multidomain pseudospectral method and those using the finite‐difference time‐domain (FDTD) method clearly illustrates the superiority of the algorithm developed in this paper. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 92–96, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21091
Novel sulfobetaine‐sulfonic acid‐contained superswelling hydrogels
Authors: Kabiri Kourosh , Faraji‐Dana Sara , Zohuriaan‐Mehr Mohammad J. 
Published: August 2005

AbstractNovel hydrogels based on zwitterionic monomer [3‐(methacrylamido)propyl] dimethyl (3‐sulfopropyl) ammonium hydroxide (MPDSAH) and a strong acid monomer (2‐acrylamido‐2‐methylpropane sulfonic acid, AMPS) were synthesized through solution polymerization under normal conditions to achieve nearly quantitative gel yield. The structure of the gels was confirmed using infrared spectroscopy. Thermal properties were simultaneously studied by differential scanning calorimetry and thermogravimetric analysis (DSC/TGA). The effects of the polymerization variables on the swelling capacity of the products were investigated. It was found that, in a certain range of the monomers mol ratio, increase of AMPS content was surprisingly accompanied with swelling reduction. The swelling exhibited lower sensitivity to the crosslinker concentration (range 0.6–1.2 wt%) compared with the conventional superabsorbents. However, in contrast with the conventional acrylic acid‐based superabsorbents, the neutralization degree of AMPS part of the new gels had only a small enhancing effect on their swelling capacity. The effect of total monomer concentration on the hydrogel absorbency was also studied. The fully ionic hydrogels showed an unusual pH‐independency behavior, so that their absorbency was nearly unchanged in a wide range of pH. Such unexpected behavior was also observed for the swelling in the ionic environments with various ionic strengths. Copyright © 2005 John Wiley & Sons, Ltd.