bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reappraising race? Dominicans in New York City
Authors: Howard David 
Published: July 2003

AbstractHow do Dominican migrants living in New York City relate to the changing social and cultural contexts that accompany experiences of migration, settlement and return? Dominicans, on migrating to the United States, confront a blunt racialised categorisation of black, white, Asian or latino/a, as opposed to the seemingly more fluid labelling in the Caribbean. In this paper, which draws on interview‐based research in the US and the Dominican Republic, I explore the impact of contemporary international migration on racialised discourse and identification among Dominicans. Given the popular and historical rejection of African Caribbean or black identity in Dominican society, migrants who would not identify asnegro/a(literally translated as black) ormulato/ain the Dominican Republic, find themselves being labelled as black Hispanic or latino/a in the US. Increasing emigration and transnational connections since the 1960s have not heralded a predicted re‐evaluation of racialised discourse in the Dominican Republic. The commonly used termindio/a, which retains meanings specific to the Dominican context with regard to the rejection ofnegritudand concomitant anti‐Haitian sentiment, remains a popular term of reference among Dominican migrants and returnees. While Dominicans living in the US may ‘overcome the legacy of denial regarding the African part of their heritage’ (Torres‐Saillant and Hernández, 1998: 145), I argue that the much‐vaunted dynamics of transnationalism have so far failed to lead to a full reappraisal of racialised identification in Dominican society, both on the island and within the US. Transnational experiences, rather than stimulating a wider understanding of race, have promoted stasis or further reinforced existing racialised identities and prejudice. Copyright © 2003 John Wiley & Sons, Ltd.
Diaspora unbound: Muslim identity and the erratic regulation of Islam in France
Authors: Samers Michael E. 
Published: July 2003

AbstractDespite the apparent innocuity of the diaspora concept, it has not escaped critical reflection and sustained debate. Some have bemoaned its obscurantist fetishism, and in particular its reliance on ‘ethnic essentialism’, while others defend it as a useful metaphor for explaining at least some types of migrant communities. In terms of the latter, Sayyid (2000) argued for a Muslim umma – a shared identity that may be considered ‘diasporic’. While he certainly had reservations about its use, he argued that reference to a diasporic umma need not imply unanimity among those supposedly divided by seemingly more ontologically grounded social categories such as class and gender. In this paper, then, I tread a path between the critique of diaspora as an essentialist concept, and how we might employ Sayyid's conceptualisation in the context of Maghrebin (North African) migrants in France during the 1980s and 1990s. In particular, I seek to demonstrate how the state in both Algeria and France shaped the relationship between Islam and identity among Muslims of Maghrebin origin in France. Copyright © 2003 John Wiley & Sons, Ltd.
Reactive oxygen species inhibited by titanium oxide coatings
Authors: Suzuki Richard , Muyco Julie , McKittrick Joanna , Frangos John A. 
Published: July 2003

AbstractTitanium is a successful biomaterial that possesses good biocompatibility. It is covered by a surface layer of titanium dioxide, and this oxide may play a critical role in inhibiting reactive oxygen species, such as peroxynitrite, produced during the inflammatory response. In the present study, titanium dioxide was coated onto silicone substrates by radio‐frequency sputtering. Silicone coating with titanium dioxide enhanced the breakdown of peroxynitrite by 79%. At physiologic pH, the peroxynitrite donor 3‐morpholinosydnonimine‐N‐ethylcarbamide (SIN‐1) was used to nitrate 4‐hydroxyphenylacetic acid (4‐HPA) to form 4‐hydroxy‐3‐nitrophenyl acetic acid (NHPA). Titanium dioxide‐coated silicone inhibited the nitration of 4‐HPA by 61% compared to aluminum oxide‐coated silicone and 55% compared to uncoated silicone. J774A.1 mouse macrophages were plated on oxide‐coated silicone and polystyrene and stimulated to produce superoxide and interleukin‐6. Superoxide production was measured by the chemiluminescent reaction with 2‐methyl‐6‐[p‐methoxyphenyl]‐3,7‐dihydroimidazo[1,2‐a]pyrazin‐3‐one (MCLA). Titanium dioxide‐coated silicone exhibited a 55% decrease in superoxide compared to uncoated silicone and a 165% decrease in superoxide compared to uncoated polystyrene. Titanium dioxide‐coated silicone inhibited IL‐6 production by 77% compared to uncoated silicone. These results show that the anti‐inflammatory properties of titanium dioxide can be transferred to the surfaces of silicone substrates. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 396–402, 2003
Multiaxial fatigue behavior of conventional and highly crosslinked UHMWPE during cyclic small punch testing
Authors: Villarraga M. L. , Kurtz S. M. , Herr M. P. , Edidin A. A. 
Published: July 2003

AbstractPrevious observations of reduced uniaxial elongation, fracture resistance, and crack propagation resistance of highly crosslinked ultrahigh molecular weight polyethylene (UHMWPE) have contributed to concern that the technology may not be appropriate for systems undergoing cyclic fatigue loading. Using a “total life” approach, we examined the influence of radiation crosslinking on the fatigue response of UHMWPE under cyclic loading via the small punch test. Our goal in this study was to evaluate the suitability of the small punch test for conducting miniature‐specimen, cyclic loading, and fatigue experiments of conventional and highly crosslinked UHMWPE. We subjected four types of conventional and highly crosslinked UHMWPE to cyclic loading at 200 N/s and at body temperature in a small punch test apparatus. After failure, the fracture surfaces were characterized with the use of field emission scanning electron microscopy to evaluate the fatigue mechanisms. Cyclic small punch testing under load control was found to be an effective and repeatable method for relative assessment of the fatigue resistance of conventional and highly crosslinked UHMWPE specimens under multiaxial loading conditions. For each of the four conventional and highly crosslinked UHMWPE materials evaluated in this study, fatigue failures were consistently produced according to a power law relationship in the low cycle regimen, corresponding to failures below 10,000 cycles. The fatigue failures were all found to be consistent with a single source of initiation and propagation to failure. Our long‐term goal in this research is to develop miniature‐specimen fatigue testing techniques for characterization of retrieved UHMWPE inserts. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 298–309, 2003
In vivo comparison of the osseointegration of vacuum plasma sprayed titanium‐ and hydroxyapatite‐coated implants
Authors: Aebli Nikolaus , Krebs Jörg , Stich Hermann , Schawalder Peter , Walton Mark , Schwenke Daryl , Gruner Heiko , Gasser Beat , Theis Jean‐Claude 
Published: July 2003

AbstractFor the last 15 years, orthopedic implants have been coated with hydroxyapatite (HA) to improve implant fixation. The osteoconductive effect of HA coatings has been demonstrated in experimental and clinical studies. However, there are ongoing developments to improve the quality of HA coatings. The objective of this study was to investigate whether a rough and highly crystalline HA coating applied by vacuum plasma spraying (VPS) had a positive effect on the osseointegration of special, high‐grade titanium (Ti) implants with the same surface roughness. Ti alloy implants were coated (VPS) with special, high‐grade Ti or HA. The osseointegration of the implants was evaluated by either light microscopy or pullout tests after 1, 2, and 4 weeks of unloaded implantation in the cancellous bone of 18 sheep. The interface shear strength increased significantly over all time intervals. By 4 weeks, values had reached ∼10N/mm2. However, the difference between the coatings was not significant at any time interval. Direct bone–implant contact was significantly different between the coatings after 2 and 4 weeks, and reached 46% for Ti and 68% for HA implants by 4 weeks. This study indicates that the use of a rough and highly crystalline HA coating, applied by VPS, enhances early osseointegration. Accelerated establishment of secondary implant fixation decreases the risk of early loosening. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 356–363, 2003
Preparation of macroporous biodegradable poly(L‐lactide‐co‐ϵ‐caprolactone) foams and characterization by mercury intrusion porosimetry, image analysis, and impedance spectroscopy
Authors: Maquet V. , Blacher S. , Pirard R. , Pirard J.‐P. , Vyakarnam M. N. , Jérôme R. 
Published: July 2003

AbstractTwo poly(L‐lactide‐co‐ϵ‐caprolactone) random copolymers containing 5 and 40 mol % of ϵ‐CL, namely P(LA‐co‐CL5) and P(LA‐co‐CL40), respectively, have been made macroporous by freeze‐drying solutions in dimethylcarbonate. Most of the freeze‐dried foams, prepared by varying polymer concentration and cooling rate, exhibited two main pore populations: (1) longitudinally oriented tube‐like macropores with diameters ≥100 μm, and (2) interconnected micropores (10–100 μm). Pore characteristics, including macropore density, mean diameter, and interdistance, as well as micropore density, area, and shape, were determined by image analysis of scanning electron micrographs in order to study the influence of processing and formulation parameters on foam structure and properties. The pore orientation and the 3‐D texture also were studied by image analysis and impedance spectroscopy. In the case of the P(LA‐co‐CL5), the macropore diameter increased with the cooling rate while the micropore diameter decreased. The micropores also became more circular when the cooling rate was increased. The pore size and morphology of the P(LA‐co‐CL40) were quite unchanged by varying the cooling rate. All the other conditions being the same, the P(LA‐co‐CL5) foams were better organized than the P(LA‐co‐CL40) foams, and pore orientation was improved at the higher cooling rate. Pore size and morphology also can be controlled by changing the polymer concentration (Cp), as we showed by studying P(LA‐co‐CL5) foams prepared by freeze‐drying solutions in the 1–10 w/v % Cp range. Macropore density, average diameter, and interdistance of P(LA‐co‐CL5) foams increased with Cp, but the micropore characteristics remained almost unchanged no matter the Cp. The reliability of the characterization methods has been discussed, with special attention to mercury intrusion porosimetry, which is used primarily for measurement of pore volume and pore size distribution. However, this technique is reported here as a destructive and unreliable method for the characterization of fragile P(LA‐co‐CL40) foams. This study shows that image analysis and impedance spectroscopy can give reliable information relative to the pore morphology and anisotropy of freeze‐dried foams. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A:199–213, 2003
Piezoelectric and mechanical properties in bovine cornea
Authors: Jayasuriya A. C. , Scheinbeim J. I. , Lubkin V. , Bennett G. , Kramer P. 
Published: July 2003

AbstractThe piezoelectric coefficient (d31) and Young's modulus (E) were investigated as a function of degree of hydration for bovine cornea. The piezoelectric and mechanical responses observed were anisotropic, and d31 decreased, whereas E increased with decreasing the degree of hydration. The anisotropic mechanical and electromechanical properties observed seem to be caused by oriented crystalline collagen fibrils. In addition, the loss of water molecules appears to decrease crystallinity (of the collagen) in the cornea. With dehydration of the cornea, a reduction in crystallinity and changes in hydrogen bonding were observed by wide‐angle X‐ray diffraction and Fourier transform infrared measurements. The decrease of piezoelectricity in cornea during dehydration is most likely caused by the increase in modulus and the loss of order to a nonpiezoelectric phase in the collagen. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 260–265, 2003
Surface chemistry modulates fibronectin conformation and directs integrin binding and specificity to control cell adhesion
Authors: Keselowsky Benjamin G. , Collard David M. , García Andrés J. 
Published: July 2003

AbstractIntegrin‐mediated cell adhesion to proteins adsorbed onto synthetic surfaces anchors cells and triggers signals that direct cell function. In the case of fibronectin (Fn), adsorption onto substrates of varying properties alters its conformation/structure and its ability to support cell adhesion. In the present study, self‐assembled monolayers (SAMs) of alkanethiols on gold were used as model surfaces to investigate the effects of surface chemistry on Fn adsorption, integrin binding, and cell adhesion. SAMs presenting terminal CH3, OH, COOH, and NH2 functionalities modulated adsorbed Fn conformation as determined through differences in the binding affinities of monoclonal antibodies raised against the central cell‐binding domain (OH > COOH = NH2 > CH3). Binding of α5β1 integrin to adsorbed Fn was controlled by SAM surface chemistry in a manner consistent with antibody binding (OH > COOH = NH2 > CH3), whereas αV integrin binding followed the trend: COOH >> OH = NH2 = CH3, demonstrating α5β1 integrin specificity for Fn adsorbed onto the NH2 and OH SAMs. Cell adhesion strength to Fn‐coated SAMs correlated with α5β1 integrin binding (OH > COOH = NH2 > CH3), and experiments with function‐perturbing antibodies demonstrated that this receptor provides the dominant adhesion mechanism in this cell model. This work establishes an experimental framework to analyze adhesive mechanisms controlling cell‐surface interactions and provides a general strategy of surface‐directed control of adsorbed protein activity to manipulate cell function in biomaterial and biotechnological applications. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 247–259, 2003
Influence of polymeric additives on the biological properties of brushite cements: An experimental study in rabbit
Authors: Flautre B. , Lemaître J. , Maynou C. , Van Landuyt P. , Hardouin P. 
Published: July 2003

AbstractThe resorbability and ability of calcium phosphate hydraulic cements to promote new bone formation was investigated in vivo. The effects of two hydrosoluble polymeric additives (hyaluronic acid, and xanthan gum,) on the biological response of two brushite cement formulations (BHC‐A vs BHC‐B) was investigated. The brushite cements differed in P/Ca (0.71 vs 0.98) and S/Ca (0.10 vs 0.005) atomic ratios and by the presence of calcium sulfate hemihydrate in BHC‐A. Polymer‐free cements were used as controls. Cement specimens were injected in cylindrical bone defects manually drilled in the distal condyle of rabbit femora. The implants were harvested at 12 and 24 weeks after implantation and subjected to quantitative histomorphometry. The study showed a significantly lower resorption rate for cement BHC‐A, which induces the formation of well‐mineralized bone in close apposition to the residual material. In contrast, cement BHC‐B showed a significant increase of bone formation period and the formation of a thick layer of unmineralized osteoid tissue at the bone/residual cement interface. The presence of xanthan gum made the biological response even worse, particularly in the case of cement BHC‐B. The presence of hyaluronic acid has little effect, except for a slight decrease in initial resorption rate, in the case of cement BHC‐A. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 214–223, 2003
Flexible chitin films as potential wound‐dressing materials: Wound model studies
Authors: Yusof Nealda Leila Binte Muhammad , Wee Aileen , Lim Lee Yong , Khor Eugene 
Published: July 2003

AbstractChitin films possessing increased flexibility, softness, transparency, and conformability have been prepared. These attributes enable the potential application of chitin films as occlusive, semipermeable film wound dressings similar to commercial products such as Opsite™. The chitin films are generally nonabsorbent, exhibiting a total weight gain of only up to 120–160% in physiological fluid. Dry chitin films transpire water vapor at a rate of about 600 g/m2/24 h, similar to commercial polyurethane‐based film dressings, but rises to 2400 g/m2/24 h, when wet, which is higher than the water vapor transmission rate of intact skin. The chitin films are nontoxic to human skin fibroblasts, maintaining 70–80% cell viability. Wound studies using a rat model showed no signs of allergenicity or the high inflammatory response associated with biodegradable biomaterials. The chitin films displayed accelerated wound‐healing properties. Based on histological examination, wound sites dressed with the chitin films stabilized and healed faster, and appeared stronger than those dressed with Opsite™ and gauze dressings after 7 days of healing. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 224–232, 2003
Preparation of antibacterial silver‐doped silica glass microspheres
Authors: Kawashita Masakazu , Toda Shogo , Kim Hyun‐Min , Kokubo Tadashi , Masuda Noriaki 
Published: July 2003

AbstractVarious types of inorganic substances doped with silver ions have been developed as antibacterial materials, and some have already been commercialized. Colorless and chemically durable materials that slowly release silver ions are, however, still need to be developed. The present authors have previously shown that when a silica glass doped with silver and aluminium ions is prepared using the sol‐gel method, the resultant product is colorless, chemically durable, and slowly releases silver ions into water over a long period. The doped silica glass takes a form of microspheres <1 μm in diameter, it is easily mixed with organic polymers, and the mixture can be formed into a thin film or fine fibers, etc. We report on the preparation of silver doped silica glass microspheres having a diameter =1 μm, using the sol‐gel method. Initially, tetraethoxysilane was partially prehydrolyzed by water in ethanol, and then aluminium triisopropoxide was added to the solution to form SiOAl bonds. Finally, an ammonia solution containing silver nitrate was added to form silica microspheres doped with silver ion together with aluminium ions. The results show monodispersed microspheres 0.4–0.6 μm in diameter were obtained with nominal compositions of Si/Al/Ag = 1/0.01–0.03/0.003–0.03, with a molar ratio of Al/Ag = 1–3.3. The microspheres were colorless, showed a high chemical durability, and slowly released silver ions into water at 37°C. Microspheres with the composition Si/Al/Ag = 1/0.01/0.01 showed excellent antibacterial activity against Escherichia coli. The minimum inhibitory concentration (MIC) of the microspheres was 400, which is less than the MIC value (800) of commercial antibacterial materials. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 266–274, 2003
Exposure of fibrinogen‐adherent platelets to plasma proteins: A new method for studying protein interactions with platelets
Authors: Broberg Marita , Nygren Håkan 
Published: July 2003

AbstractTo understand the effects of mediators in coagulating blood at biomaterial surfaces, it is important to use methods that resemble the normal sequence of events in wound healing around implants. The initial adhesion of platelets from whole blood onto material surfaces is mediated by the fibrinogen receptor glycoprotein IIb/IIIa, as shown in a previous study (Broberg et al., J Lab Clin Med 2002; 139:163–172). In this study, isolated platelets were adhered to fibrinogen and exposed to IgG, von Willebrand factor, or thrombin. The response was detected as the number of adherent platelets, the spreading of platelets, the exposure of CD62P (P‐selectin), and the release of platelet factor 4 (PF4), ADP, and ATP. These results were compared to the response of platelets adhering to surfaces coated with the same proteins. Fibrinogen‐adherent platelets exposed to thrombin generated the significantly highest exposure of CD62P and release of PF4, ADP, and ATP. When platelets were adhered to different protein coatings, von Willebrand factor generated the most CD62P exposure, IgG generated the most PF4 release, and thrombin generated the highest concentration of ADP. These results indicate that protein interactions with platelets may generate different results, depending on the mode of protein exposure. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 403–410, 2003
A preliminary study on the enhancement of the osteointegration of a novel synthetic hydroxyapatite scaffold in vivo
Authors: Damien Elsie , Hing Karin , Saeed Suhur , Revell Peter A. 
Published: July 2003

AbstractSynthetic hydroxyapatite, a bioactive calcium phosphate, is clinically used as a bone replacement bioceramic because of its similarity in composition to bone mineral, biocompatibility, and osteoconductive nature. The aim of this study was to evaluate the bioactivity of a novel synthetic porous hydroxyapatite (PHA) in vivo in rabbit and to investigate the enhancement of its bioactivity and osteointegration. In the investigation reported here, insulin‐like growth factor‐I (IGF‐I) has been used to enhance the bioactivity of PHA. Cylindrical PHA implants with or without IGF‐I were implanted bilaterally in rabbit femurs. Fluorochrome bone markers were administered at 7‐day intervals. The implants with the attached bone were retrieved at postmortem, 1 and 3 weeks after implantation, for histological and histomorphometric analysis. Undecalcified sections stained with toluidine blue showed new bone formation. Mineralization of the new bone formed in the interface, surrounding trabecular bone, and within the pores of the implants was studied. Lamellar bone mineral apposition rate (MAR) was assessed and compared among treatment groups, sham, PHA alone, and PHA with IGF‐I (500 ng/implant), by fluorochrome label incorporation using UVL microscopy. We report for the first time, that the supplementation of PHA implants with IGF‐I significantly increased new bone formation and MAR (6.58 ± 0.08 μm/day) compared with implantation of PHA alone (4.08 ± 0.05 μm/day) or sham operation (3.11 ± 0.12 μm/day). These results suggest that synthetic PHA might provide a delivery system for bioactive agents to accelerate bone healing in orthopedic procedures. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 66A: 241–246, 2003