bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monetary policy analysis and inflation targeting in a small open economy: a VAR approach*
Authors: Jacobson Tor , Jansson Per , Vredin Anders , Warne Anders 
Published: August 2002

AbstractEmpirical monetary policy research has increased in the last decade, possibly because deregulation and explicit monetary targets have made monetary policy issues more interesting. In particular, within the inflation targeting framework it has been argued that inflation forecasts can be used as optimal intermediate targets for monetary policy, and the development of empirical models that have good forecasting properties is therefore important. This paper shows that a VAR model with long‐run restrictions, justified by economic theory, is useful for both forecasting inflation and for analysing other issues that are central to the conduct of monetary policy. Copyright © 2001 John Wiley & Sons, Ltd.
Unemployment insurance and subsequent job duration: job matching versus unobserved heterogeneity
Authors: Belzil Christian 
Published: August 2002

AbstractThe relationship between Unemployment Insurance (UI) benefit duration, unemployment duration and subsequent job duration is investigated using a multi‐state duration model with state specific unobserved heterogeneity. I examine two potential explanations for the negative correlation between unemployment and job spell durations; UI benefits increase job matching quality (the ‘Matching’ effect) versus unobserved heterogeneity (‘Adverse Selection’). The Matching effect is found to be weak. Although new jobs accepted within 5 weeks of benefit termination seem to have a higher dissolution rate, the negative correlation between unemployment and job duration is mostly explained by unobserved heterogeneity. Various simulations indicate that increasing the maximum benefit duration by one week will raise expected unemployment duration by 1.0 to 1.5 days but will raise expected job duration by 0.5 to 0.8 day only. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of the oestrogenic (uterotrophic) activity of extracts of ‘general purpose polystyrene (GPPS)’ using immature female rats
Authors: Prinsen Menk K. , Gouko Nobuaki 
Published: August 2002

AbstractIn Japan there is growing concern about the possible adverse effects of consumption of food from styrene containers (mainly those made from polystyrene paper) due to the alleged oestrogenic activity of styrene oligomers (dimers and trimers), which may migrate into the food. To examine the possible oestrogenic activity of styrene dimers and trimers, extracts were made from ‘general purpose polystyrene (GPPS)’ and administered orally to immature female rats over a 4 day period. Increase of uterus weight (wet and blotted) was used for assessment of possible oestrogenic activity. To establish the sensitivity of the test method, immature rats were treated with diethylstilboestrol (DES), a well‐known oestrogenic compound.It was found that treatment of rats with levels of up to 60 μg of styrene dimers and 930 μg of styrene trimers per kilogram body weight per day did not give any statistically significant increase of the uterus weight (wet or blotted), whereas DES caused statistically significant, dose‐related increases in uterus weight at levels as low as 0.89 μg kg−1 body weight day−1. It was concluded that, compared with the estimated maximum human daily intake of styrene trimers of 1 μg kg−1 body weight day−1 from polystyrene food containers, the risk of adverse human health effects with respect to oestrogenicity may be considered negligible. Copyright © 2001 John Wiley & Sons, Ltd.
Influence of lead and zinc on rat male reproduction at ‘biochemical and histopathological levels’
Authors: Batra N. , Nehru B. , Bansal M. P. 
Published: August 2002

AbstractSequential lead accumulation and biochemical and histopathological changes were observed in rat testis and epididymis after oral administration at varied doses of lead (10, 50 and 200 mg kg−1 body wt.) for 3 months and also following the concomitant administration of lead with zinc (1 mg kg−1 body wt. +50 mg Pb kg−1 body wt.). Accumulation of lead in both testis and epididymis increased with dose. The concomitant administration of zinc reduced the lead levels. Similarly, dose‐related changes were seen in the activities of the enzymes alkaline phosphatase and Na+–K+‐ATPase, which decreased with increased dose of lead. A significant improvement in the activities of these enzymes was seen in the groups given both lead and zinc. Histologically, discernible changes were noticed only at higher doses (50 and 200 mg kg−1 body wt.), which included disorganization and disruption of spermatogenesis with accumulation of immature cells in lumen of tubule. At higher doses of lead, complete arrest of spermatogenesis was seen and a significant decrease in germ cell layer population was evident. Even in epididymis, the histoarchitecture was disrupted only at higher doses of lead both in the caput and corpus regions. The changes included damage of basement membrane, disorganization of epithelium and vacuolization of cells. The tubules were found almost empty, indicating arrest of spermatogenesis. However, with concomitant administration of lead and zinc both testis and epididymis presented a near‐normal picture, indicating the protective role of zinc. Hence, the data indicate that the protective effect of zinc on lead toxicity was mediated largely by significant competition between lead and zinc or due to reduction of the available binding sites. Copyright © 2001 John Wiley & Sons, Ltd.
In vivo evaluation of a dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to implantable medical devices
Authors: Hickey T. , Kreutzer D. , Burgess D. J. , Moussy F. 
Published: August 2002

AbstractThe purpose of this research effort was to evaluate in vivo a newly developed dexamethasone/PLGA microsphere system designed to suppress the inflammatory tissue response to an implanted device, in this case a biosensor. The microspheres were prepared using an oil/water (O/W) emulsion technique. The microsphere system was composed of drug‐loaded microspheres (including newly formulated and predegraded microspheres) and free dexamethasone. The combination of the drug and drug‐loaded microspheres provided burst release of dexamethasone followed by continuous release from days 2–14. Continuous release to at least 30 days was achieved by mixing predegraded and newly formulated microspheres. The ability of our mixed microsphere system to control tissue reactions to an implant then was tested in vivo using cotton thread sutures to induce inflammation subcutaneously in Sprague−Dawley rats. Two different in vivo studies were performed, the first to find the dosage level of dexamethasone that effectively would suppress the acute inflammatory reaction and the second to show how effective the dexamethasone delivered by PLGA microspheres was in suppressing chronic inflammatory response to an implant. The first in vivo study showed that 0.1 to 0.8 mg of dexamethasone at the site minimized the acute inflammatory reaction. The second in vivo study showed that our mixed microsphere system suppressed the inflammatory response to an implanted suture for at least 1 month. This study has proven the viability of microsphere delivery of an anti‐inflammatory to control the inflammatory reaction at an implant site. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 61: 180–187, 2002
Comparitive study of the formation of hydroxyapatite in simulated body fluid under static and flowing systems
Authors: Siriphannon Punnama , Kameshima Yoshikazu , Yasumori Atsuo , Okada Kiyoshi , Hayashi Shigeo 
Published: August 2002

Abstractα‐CaSiO3 ceramics of nominal composition CaO 46.0, SiO2 54.0, and Na2O 0.4 mass% were soaked in simulated body fluid (SBF). The soaking systems were maintained under both static and flowing conditions to study their effect on the formation of hydroxyapatite (HAp). Two different flowing systems were designed for soaking, namely, a closed system using a fast flow rate of about 2.8 mL/s (circulating system) and an open system using a slow flow rate of about 40 mL/day (slow flowing system). The HAp layer in all samples initially formed as a rough layer of ball‐like particles. Under a fast flow of SBF solution, silica gel particles peeled from silica‐rich interlayer during the first soaking period. The silica gel particles then reattached to the product HAp layer and induced the formation of new HAp particles of smaller size. In the slow flowing system, the rough HAp layer initially formed on the ceramic surfaces became gradually smoother after prolonged soaking. The formation rate and thickness of the HAp layer decreased with increasing flow rate of the SBF solution. These results indicate that flowing SBF solution gives rise to differences in the formation rates, formation behavior, and microstructure of the HAp layer. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 175–185, 2002
Biomechanical comparison of the sandblasted and acid‐etched and the machined and acid‐etched titanium surface for dental implants
Authors: Li Dehua , Ferguson Stephen J. , Beutler Thomas , Cochran David L. , Sittig Caroline , Hirt Hans Peter , Buser Daniel 
Published: August 2002

AbstractTo make a direct biomechanical comparison between the sandblasted and acid‐etched surface (SLA) and the machined and acid‐etched surface (MA), a well‐established animal model for implant removal torque testing was employed, using a split‐mouth experimental design. All implants had an identical cylindrical solid‐screw shape with the standard ITI thread configuration, without any macroscopic retentive structures. After 4, 8, and 12 weeks of bone healing, removal torque testing was performed to evaluate the interfacial shear strength of each surface type. Results showed that the SLA surface was more powerful in enhancing the interfacial shear strength of implants in comparison with the MA surface. Removal torque values of the SLA‐surfaced implants were about 30% higher than those of the MA‐surfaced implants (p = 0.002) except at 4 weeks, when the difference was at the threshold of statistical significance (p = 0.0519). The mean removal torque values for the SLA implants were 1.5074 Nm at 4 weeks, 1.8022 Nm at 8 weeks, and 1.7130 Nm at 12 weeks; and correspondingly, 1.1924 Nm, 1.3092 Nm, and 1.3226 Nm for the MA implants. It can be concluded that the SLA surface achieves a better bone anchorage than the MA surface, and that sandblasting before acid etching has a beneficial effect on the interfacial shear strength. As regards the bone–implant interfacial stiffness calculated from the torque‐rotation curve, the SLA implants showed an overall more than 5% higher stiffness compared with the MA implants, although the difference did not reach the statistical significance level. © 2002 John Wiley & Sons, Inc. J Biomed Mater Res 60: 325–332, 2002; DOI 10.1002/jbm.10063
Prophylactic treatment of gram‐positive and gram‐negative abdominal implant infections using locally delivered polyclonal antibodies
Authors: Poelstra Kornelis A. , Barekzi Nazir A. , Rediske Andrea M. , Felts Adrian G. , Slunt Jeffrey B. , Grainger David W. 
Published: August 2002

AbstractThe increasing clinical incidence and host risk of biomaterial‐centered infections, as well as the reduced effectiveness of clinically relevant antibiotics to treat such infections, provide compelling reasons to develop new approaches for treating implanted biomaterials in a surgical context. We describe the direct local delivery of polyclonal human antibodies to abdominal surgical implant sites to reduce infection severity and mortality in a lethal murine model of surgical implant‐centered peritoneal infection. Surgical implant‐centered peritonitis was produced in 180 female CF‐1 mice by the direct inoculation of surgical‐grade polypropylene mesh disks placed in the peritoneal cavity with lethal doses of either methicillin‐resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. Mice randomly received a resorbable antibody delivery vehicle at the implant site: either a blank carboxymethylcellulose (CMC) aqueous gel or the same CMC gel containing 10 mg of pooled polyclonal human immunoglobulin G locally on the implant after infection, either alone or in combination with systemic doses of cefazolin or vancomycin antibiotics. Human antibodies were rapidly released (first‐order kinetics) from the gel carrier to both peritoneal fluids and serum in both infection scenarios. Inocula required for lethal infection were substantially reduced by surgery and the presence of the implant versus a closed lethal peritonitis model. Survival to 10 days with two different gram‐negative P. aeruginosa strains was significantly enhanced (p < 0.01) by the direct application of CMC gel containing antibodies alone to the surgical implant site. Human‐equivalent doses of systemic vancomycin provided a significantly improved benefit (p < 0.01) against lethal, implant‐centered, gram‐positive MRSA infection. However, locally delivered polyclonal human antibodies in combination with a range of systemic vancomycin doses against MRSA failed to improve host survival. Successful antibody therapy against gram‐negative, implant‐centered infections complements the clinically routine use of systemic antibiotics, providing a mechanism of protection independent of antibiotic resistance. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 206–215, 2002
Biodegradable polyurethanes for implants. II. In vitro degradation and calcification of materials from poly(ϵ‐caprolactone)–poly(ethylene oxide) diols and various chain extenders
Authors: Gorna Katarzyna , Gogolewski Sylwester 
Published: August 2002

AbstractLinear, biodegradable, aliphatic polyurethanes with various degrees of hydrophilicity were synthesized in bulk at 50–100°C. The ratios between the hydrophilic and hydrophobic segments were 0:100, 30:70, 40:60, 50:50, and 70:30, respectively. The hydrophilic segment consisted of poly(ethylene oxide) (PEO) diol (molecular weight = 600 or 2000) or the poly(ethylene–propylene–ethylene oxide) (PEO–PPO–PEO) diol Pluronic F‐68 (molecular weight = 8000). The hydrophobic segment was made of poly(ϵ‐caprolactone) diol (molecular weight = 530, 1250, or 2000). The chain extenders were 1,4‐butane diol and 2‐amino‐1‐butanol. The diisocyanate was aliphatic hexamethylene diisocyanate. The polymers absorbed water in an amount that increased with the increasing content of the PEO segment in the polymer chain. The total amount of absorbed water did not exceed 2% for the poly(ester urethane)s and was as high as 212% for some poly(ester ether urethane)s that behaved in water like hydrogels. The polymers were subjected to in vitro degradation at 37 ± 0.1°C in phosphate buffer solutions for up to 76 weeks. The poly(ester urethane)s showed 1–2% mass loss at 48 weeks and 1.1–3.8% mass loss at 76 weeks. The poly(ester ether urethane)s manifested 1.6–76% mass loss at 48 weeks and 1.6–96% mass loss at 76 weeks. The increasing content and molecular weight of the PEO segment enhanced the rate of mass loss. Similar relations were also observed for polyurethanes from PEO–PPO–PEO (Pluronic) diols. Materials obtained with 2‐amino‐1‐butanol as the chain extender degraded at a slower rate than similar materials synthesized with 1,4‐butane diol. All the materials already manifested a progressive decrease in the molecular weight in the first month of in vitro aging. The rate of molecular weight loss was higher for poly(ester ether urethane)s than for poly(ester urethane)s. For poly(ester ether urethane)s, the rate of molecular weight loss was higher for materials containing Pluronic than for those containing PEO segments. All polymers calcified in vitro. The susceptibility to calcification increased with material hydrophilicity. The progressive deposition of calcium salt on the film surfaces resulted in the formation of large crystal aggregates, the structure of which depended on the chemical composition of the calcified material. Needlelike aggregates, resembling brushite, formed on the hydrophobic polyurethane, and platelike crystals formed on the highly hydrophilic material. The calcium‐to‐phosphorus atomic ratio of the crystals growing on the samples was dependent on the chemical composition of the material and varied from 0.94 to 1.55. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 592–606, 2002
Concentration‐ and composition‐dependent effects of metal ions on human MG‐63 osteoblasts
Authors: Hallab Nadim James , Vermes Csaba , Messina Carlo , Roebuck Kenneth A. , Glant Tibor T. , Jacobs Joshua J. 
Published: August 2002

AbstractMetal debris from implants has been shown to alter the function of osteoblasts in cell cultures. Its remains unclear, however, if specific forms of released ionic metals are involved in the pathogenesis of periprosthetic osteolysis. We evaluated the relative effects of ionic forms of implant metals by treating human osteoblast‐like MG‐63 osteosarcoma cells with eight concentrations (0.001–10.0 mM) of Cr+3, Mo+5, Al+3, Ta+5, Co+2, Ni+2, Fe+3, Cu+2, Mn+2, Mg+2, Na+2, and V+3 chloride solutions. The results demonstrated that the metal ions differentially affected osteoblast proliferation, viability, type‐I collagen gene expression, and cytokine release. The metal ions were ranked in order from least to most toxic (based on a 50% reduction in viability) as follows: Na < Cr < Mg < Mo < Al < Ta < Co < Ni < Fe < Cu < Mn < V. Metal‐induced decreases in osteoblast proliferation were similar in ranking. Nontoxic concentrations of metals had no effect on procollagen α1[I] gene expression; only at toxic concentrations did metals produce a decrease in gene expression. The most toxic metals (V, Mn, Fe, and Ni) were also the only metals found to induce IL‐6 secretion on a per cell basis (of the cytokines tested, interleukin 6 (IL‐6), interleukin beta 1 (IL‐1β), transforming growth factor beta 1 (TGF‐β1), and tumor necrosis factor alpha (TNF‐α), only IL‐6 was detectable in the culture medium after 48 h for any metal at any concentration). Less toxic metals (e.g., Co and Cr) had little effect on IL‐6 release, even at high concentrations. In general, metal ions reduced osteoblast function (i.e., proliferation and collagen gene expression) in proportion to the degree of toxicity. These results support the hypothesis that adverse local cellular responses (particularly necrotic responses) associated with metal debris from implanted metallic devices may be due in part to metal ions released from implants or from particulate debris. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 60: 420–433, 2002; DOI 10.1002/jbm.10106
A comparison of the shapes of hydroxyapatite implants before and after implantation
Authors: Abe Keita , Ono Ichiro 
Published: August 2002

AbstractBased on helical volume scan computed tomography (HVCT) data, it has been demonstrated previously that real‐size models can be prepared with the binder‐jet method with extremely high precision of various parts ranging from the outer structure of the cranio‐maxillofacial bone to such fine parts as the cranial base and the orbital walls. The application of this method to clinical cases with large cranial bone defects has also been studied. The results showed the usefulness of the binder‐jet method, employing starch for fixing, with which a model can be prepared faster and with less deformity caused by the weight of the material itself. Therefore, the binder‐jet method is expected to attain greater clinical significance in this field.In this study the comparison between the shapes of implants before and after implantation revealed that the most important aspect of the design of hydroxyapatite (HAP) implants was determining the shapes of edges, especially its angles. That is, an implant needs very little trimming before being implanted to the patient's defective site if the shape of the edges of the implant can be designed and prepared to fix the incised bone surfaces properly. In addition, to obtain optimum results it was also shown that it is necessary to design optimal shapes of implants, taking into account thickness, porosity, and curvature, before processing the shapes of edges. It was found necessary to establish a technology and a method for producing HAP implants that perfectly fit cranial bone defects. For this purpose, it would be useful to make a template of the implants using the mirror‐reversion and binder‐jet methods. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 312–318, 2002
The hydrolytic degradation of polydioxanone (PDSII) sutures. Part II: Micromechanisms of deformation
Authors: Ping Ooi Chui , Cameron Ruth E. 
Published: August 2002

AbstractAn investigation of morphological changes in hydrolytically degraded polydioxanone sutures (PDSII) during in situ tensile deformation is reported. These changes were followed with the use of real‐time small‐angle X‐ray scattering with simultaneous tensile deformation experiments. The results are correlated with separately performed wide‐angle X‐ray scattering, and optical microscopy experiments on the effects of tensile strain. Interlamellar and interfibrillar amorphous regions appear to control the microdeformation and the shape of the stress‐strain curves of PDSII sutures. The fibers deform initially by interlamellar separation and at larger strains by fibrillar slip. Fractures appear to be caused by the catastrophic growth of cracks. The degradation of interlamellar tie chains in PDSII sutures does not appear to significantly affect the progress of deformation, because deformation through interlamellar separation is largely unchanged by degradation. Conversely, hydration and scission of interfibrillar tie chains lowers the load required to propagate interfibrillar shear. The fibers fail at progressively lower strains as degradation proceeds. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 291–298, 2002
Porous structure of Purevision™ versus Focus® Night&Day™ and conventional hydrogel contact lenses
Authors: López‐Alemany Antonio , Compañ Vicente , Refojo Miguel F. 
Published: August 2002

AbstractThe surface and bulk structures of hydrogel contact lenses that contain siloxane moieties, Purevision™ (balafilcon A) and Focus®Night&Day™ (lotrafilcon A), were investigated. Standard hydrogel lenses of low (Seequence®), medium (Acuvue®), and high water content (Precision UV®) were used as controls. All the lenses were dehydrated in a series of ethanol solutions of increased concentration, critical‐point dried in CO2, and sputter coated with gold/palladium before they were examined by scanning electron microscopy. Of all lenses examined, only the balafilcon lenses presented, in addition to the polymer network porosity characteristic of all hydrogels, a macroporous structure that was observed on the front and back surfaces, and in their bulk. The average diameter of the macropores appears to be much larger, from one to several orders of magnitude, than the network porosity of standard hydrogel lenses. The macropores might contribute to the gas and water permeability of these lenses, as well as to their mobility on the cornea. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res (Appl Biomater) 63: 319–325, 2002