bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthetic Gallic Acid Derivatives as Models for a Comprehensive Study of Antioxidant Activity
Authors: Belin Florence , Barthélémy Philippe , Ruiz Karine , Lacombe Jean Michel , Pucci Bernard 
Published: March 2003

AbstractThe synthesis and antioxidant efficiencies of amphiphilic gallic acid derivatives are reported. To specify the impact of chemical structure on the antioxidant efficiency, several structural modifications of gallic acid were performed. The following structural features were chosen: i) introduction of hydrophobic or hydrophilic residues on the gallic acid and the type of their linkage, ii) the hydrophilic and/or lipophilic character of the whole molecule. The physico‐chemical studies of the different series prepared revealed that the antioxidant efficiency of this polyphenol depends clearly on the nature of the linkage with both hydrophilic and hydrophobic parts. A push‐pull effect is always necessary, and ester or amide bonds seem well adapted to increase the antioxidant efficiency. Second, under the oxidation conditions applied, it was observed that the hydrophilic and/or lipophilic character affects drastically the antioxidant activity of gallic acid derivatives. The results obtained are in accordance with the polar paradox, hydrophobic derivatives inhibit oxidation in an aqueous phase, whereas hydrophilic products are not efficient.
T cells in myeloma
Authors: Raitakari M. , Brown R. D. , Gibson J. , Joshua D. E. 
Published: March 2003

AbstractThe current trend to develop immunotherapy strategies for patients with myeloma and other B cell malignancies has stimulated considerable interest in the functional state of the T cell population in these patients. Expanded clones of T cells exist in many patients with myeloma and their presence is associated with an improved survival. However, isolating T cells with tumour specificity has proven to be a difficult task and clinical immunization trials have so far failed to achieve a significant response. There is now evidence that tumour specific T cells are either tolerized or deleted following antigen presentation and that idiotype‐derived, immunodominant tumour peptides may not exist in all patients. In order to develop more effective immunotherapy strategies for patients with myeloma, further studies are urgently required to identify the most appropriate tumour antigen, the nature of the interactions which take place during antigen presentation, and how to promote the cytotoxicity of autologous T cells. Copyright © 2003 John Wiley & Sons, Ltd.
The impact of self‐assessment on provider performance in Mali
Authors: Kelley Edward , Kelley Allison Gamble , Simpara Cheick H. T. , Sidibé Ousmane , Makinen Marty 
Published: March 2003

AbstractImproving the quality of clinical care in developing country settings is a difficult task, both in public sector settings where supervision is infrequent and in private sector settings where supervision and certification are non‐existent. This study tested a low‐cost method, self‐assessment, for improving the quality of care that providers offer in a peri‐urban area in Mali. The study was a cross‐sectional, case–control study on the impact of self‐assessment on compliance with the quality of care standards. The two indicators of interest were the compliance with fever care standards and the compliance with structural quality standards. Both standards were derived from the Ministry of Health of Mali's standards for health care delivery. The study examined 36 providers, 12 of whom were part of the intervention and 24 of whom were part of the control group over a 3 month period from May to July 2001. Overall, the research team found a significant difference between the intervention and control groups in terms of overall compliance (p < 0.001) and in terms of assessment of fever (p < 0.005). The total costs for the intervention for 36 providers was less than US$250, which translated to approximately $6 per provider. The data appear to suggest that self‐assessment, when used in a regular fashion, can have a significant effect on compliance with standards. However, it is clear that self‐assessment is not a resource‐neutral intervention. All of the individuals from the intervention pool interviewed cited the extra work that they had to do to comply with the intervention protocol as a burden. In particular, study participants put an emphasis on the ‘long duration’ of the study that ‘discouraged’ the study participants. Future research on self‐assessment should include a larger sample of providers and should examine the impact of self‐assessment over time. Copyright © 2003 John Wiley & Sons, Ltd.
Costs of maternal health care services in three anglophone African countries
Authors: Levin Ann , Dmytraczenko Tania , McEuen Mark , Ssengooba Freddie , Mangani Ronald , Van Dyck Gerry 
Published: March 2003

AbstractThis paper is a synthesis of a case study of provider and consumer costs, along with selected quality indicators, for six maternal health services provided at one public hospital, one mission hospital, one public health centre and one mission centre, in Uganda, Malawi and Ghana. The study examines the costs of providing the services in a selected number of facilities in order to examine the reasons behind cost differences, assess the efficiency of service delivery, and determine whether management improvements might achieve cost savings without hurting quality. This assessment is important to African countries with ambitious goals for improving maternal health but scarce public health resources and limited government budgets. The study also evaluates the costs that consumers pay to use the maternal health services, along with the contribution that revenues from fees for services make to recovering health facility costs.The authors find that costs differ between hospitals and health centres as well as among mission and public facilities in the study sample. The variation is explained by differences in the role of the facility, use and availability of materials and equipment, number and level of personnel delivering services, and utilization levels of services. The report concludes with several policy implications for improvements in efficiency, financing options and consumer costs. Copyright © 2003 John Wiley & Sons, Ltd.
Recharge of aquifers by flood events in an arid region
Authors: Shentsis Isabella , Rosenthal Eliyahu 
Published: March 2003

AbstractThe process of aquifer recharge by flood events in an arid region was investigated as applied to the Hazeva Formation (the Karkom graben, the Wadi Paran watershed, Israel). The hydrological model was established as a complex system, with due regard for groundwater and transmission losses of surface runoff. It was based on a previously outlined hydrogeological model of the Karkom graben and a model of transmission losses in arid watercourses under conditions of data deficiency. Proceeding from calculation of groundwater balances, the contribution of surface runoff as a decisive balance component was confirmed. The main characteristics of aquifer regimes, such as changes in storage volume and groundwater level, as well as lateral flow, were all found to be dependent upon the net extraction rate, i.e. pumpage discounting replenishment by flood events. Analysis and physical interpretation of model parameters enabled assessment of the influence of groundwater extraction on aquifer recharge. This became apparent as increasing absorption capacity and recharge availability of the aquifer as a result of the groundwater abstraction. Copyright © 2002 John Wiley & Sons, Ltd.
Increasing transmission losses from flood events due to groundwater extraction
Authors: Shentsis Isabella 
Published: March 2003

AbstractThis study continues the examination of the influence of groundwater exploitation upon the process of aquifer recharge by flood events. In the course of the developing an earlier hydrological model for the Hazeva Formation aquifer (the Wadi Paran watershed, southern Israel), it became apparent that groundwater extraction influenced absorption capacity of sub‐aquifers and regulated the distribution of percolating surface water between units. The present study lends numerical proof regarding the influence of Hazeva aquifer exploitation upon the regime of runoff and enhancement of transmission losses from flood events in Wadi Paran, and, as a result, upon increased recharge to the aquifer. Copyright © 2002 John Wiley & Sons, Ltd.
Concentrations and transport of different forms of phosphorus during snowmelt runoff from an illite clay soil
Authors: Ulén Barbro 
Published: March 2003

AbstractDuring a 16 day period with pronounced snowmelt via surface runoff, high water concentrations (usually 0·4–0·5 mg l−1) of dissolved molybdate‐reactive phosphorus (MRP) were detected in surface runoff water from a clay soil of illite type. Other phosphorus fractions defined were: phosphorus in particles with a higher settling coefficient than 80 000 S (SPP); colloidal phosphorus caught on filters with a pore size of 0·2 µm but with a smaller settling coefficient (CPP); and dissolved phosphorus not reacting with molybdate (DUP). The order of concentrations was MRP > SPP > CPP > DUP. Nearly identical amounts of MRP, CPP, and DUP (in total 0·3 kg ha−1) were lost from a grass–clover ley and a ploughed soil. However, more of the heavier phosphorus‐containing material was lost from the ploughed area. In drainpipe water, CPP was the largest fraction (28%), and in stream water from mixed arable/forest land, MRP dominated (33%). Loss on ignition of the settling material slowly decreased from 10 to 8% (dry weight) during the snowmelt period. Total phosphorus concentrations in the material followed the runoff pattern, with slightly higher phosphorus concentrations during fast runoff. The large amounts of readily dissolved or colloidal‐bound phosphorus (70–80%) transported from this clay soil during snowmelt are discussed with regard to the use of grass buffer strips as a measure against phosphorus losses from arable land. Copyright © 2002 John Wiley & Sons, Ltd.
Analytical solutions of one‐dimensional infiltration before and after ponding
Authors: Chen Jiann‐Mou , Tan Yih‐Chi , Chen Chu‐Hui 
Published: March 2003

AbstractThis paper is a continuation of previous research, which obtained a convenient solution for arbitrary surface fluxes before ponding. By means of Fourier Transformation this has been extended to derive analytical solutions of a linearized Richards' equation for arbitrary input fluxes after surface saturation. Copyright © 2003 John Wiley & Sons, Ltd.
Characterization of lake water and ground water movement in the littoral zone of Williams Lake, a closed‐basin lake in north central Minnesota
Authors: Schuster Paul F. , Reddy Michael M. , LaBaugh James W. , Parkhurst Renee S. , Rosenberry Donald O. , Winter Thomas C. , Antweiler Ronald C. , Dean Walter E. 
Published: March 2003

AbstractWilliams Lake, Minnesota is a closed‐basin lake that is a flow‐through system with respect to ground water. Ground‐water input represents half of the annual water input and most of the chemical input to the lake. Chemical budgets indicate that the lake is a sink for calcium, yet surficial sediments contain little calcium carbonate. Sediment pore‐water samplers (peepers) were used to characterize solute fluxes at the lake‐water–ground‐water interface in the littoral zone and resolve the apparent disparity between the chemical budget and sediment data. Pore‐water depth profiles of the stable isotopes δ18O and δ2H were non‐linear where ground water seeped into the lake, with a sharp transition from lake‐water values to ground‐water values in the top 10 cm of sediment. These data indicate that advective inflow to the lake is the primary mechanism for solute flux from ground water. Linear interstitial velocities determined from δ2H profiles (316 to 528 cm/yr) were consistent with velocities determined independently from water budget data and sediment porosity (366 cm/yr). Stable isotope profiles were generally linear where water flowed out of the lake into ground water. However, calcium profiles were not linear in the same area and varied in response to input of calcium carbonate from the littoral zone and subsequent dissolution. The comparison of pore‐water calcium profiles to pore‐water stable isotope profiles indicate calcium is not conservative. Based on the previous understanding that 40–50 % of the calcium in Williams Lake is retained, the pore‐water profiles indicate aquatic plants in the littoral zone are recycling the retained portion of calcium. The difference between the pore‐water depth profiles of calcium and δ18O and δ2H demonstrate the importance of using stable isotopes to evaluate flow direction and source through the lake‐water–ground‐water interface and evaluate mechanisms controlling the chemical balance of lakes. Published in 2003 by John Wiley & Sons, Ltd.
Modulation of bone ingrowth and tissue differentiation by local infusion of interleukin‐10 in the presence of ultra‐high molecular weight polyethylene (UHMWPE) wear particles
Authors: Goodman Stuart , Trindade Michael , Ma Ting , Lee Mel , Wang Neal , Ikenou Takashi , Matsuura Ippe , Miyanishi Keita , Fox Nora , Regula Donald , Genovese Mark , Klein John , Bloch Dan , Smith R. Lane 
Published: March 2003

AbstractInterleukin‐10 (IL‐10) is a cytokine that plays a major role in suppressing the inflammatory response, particulary cell‐mediated immunity that is characteristic of the TH1 response. The purpose of this study was to determine whether local infusion of IL‐10 could mitigate the suppression of bone ingrowth associated with polyethylene wear particles. Drug test chambers were implanted in the proximal tibia of 20 mature New Zealand white rabbits. The DTC provided a continuous 1 × 1 × 5‐mm canal for tissue ingrowth. After a 6‐week period for osseointegration, the DTC was then connected to an osmotic diffusion pump. IL‐10 at doses of 0.1–100 ng/mL (0.25 μL/h) was infused with or without ultra‐high molecular weight polyethylene particles (0.5 ± 0.2 μm diameter, 1012 particles/mL) present in the chamber for a 3‐ or 6‐week period. The tissue in the chamber was harvested after each treatment; sections were stained with hematoxylin and eosin for morphometric analysis. Osteoclast‐like cells were identified by immunohistochemical staining using a monoclonal antibody directed against the alpha chain of the vitronectin receptor, CD51. Osteoblasts were identified using alkaline phosphatase staining. In dose–response studies, infusion of 1 ng/mL IL‐10 yielded the greatest bone ingrowth in the presence of particles. The addition of polyethylene particles evoked a marked foreign body reaction and fibrosis; bone ingrowth was significantly suppressed (p = 0.0003). Bone ingrowth was increased by over 48% with infusion of IL‐10 for the final 3 weeks of a 6‐week ultra‐high molecular weight polyethylene particle exposure compared with particles alone (p = 0.027). IL‐10 is a cytokine that plays a major role in suppressing the inflammatory response, especially cell‐mediated immunity that is characteristic of the TH1 response. Local infusion of immune‐modulating cytokines such as IL‐10 may prove to be useful in abating particle‐induced periprosthetic osteolysis. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 43–50, 2003
ICAM‐1 and VCAM‐1 expression by endothelial cells grown on fibronectin‐coated TCPS and PS
Authors: van der Zijpp Ype J.T. , Poot Andre A. , Feijen Jan 
Published: March 2003

AbstractSmall‐diameter vascular grafts rapidly fail as a result of blood coagulation and platelet deposition. Endothelial cells lining the inner side of blood vessels can provide the graft lumen with an antithrombogenic surface. One of the remaining problems is cell detachment after restoration of blood flow, because of infiltration of leukocytes that respond to an inflammatory‐like activation of the endothelial cells. This endothelial activation is possibly caused by the surface characteristics of the underlying polymer. To get more insight into the effects of the polymer surface on endothelial cell activation, we seeded human umbilical vein endothelial cells (HUVECs) in various densities and subsequently grew them on tissue culture polystyrene (TCPS; hydrophilic) and polystyrene (PS; hydrophobic) surfaces. To improve cell adhesion, surfaces were coated with purified fibronectin prior to cell seeding. During proliferation, the expressions of the leukocyte adhesion molecules ICAM‐1 and VCAM‐1 were determined. Results indicate that ICAM‐1 expression is not influenced by the character of the polymer surface, and that VCAM‐1 expression is slightly higher on the TCPS surface. Expressions of both adhesion molecules are influenced by the seeding density and time of proliferation. At low seeding densities (≤ 10,000 cells/cm2), a relatively low percentage of nonexogenously activated cells expressed ICAM‐1 during the first 3 days of proliferation compared to higher seeding densities. Although less pronounced, this was also observed for the percentage of cells expressing VCAM‐1. During proliferation, the amount of ICAM‐1 per endothelial cell increased, whereas the expression of VCAM‐1 remained low. The absence of large differences in leukocyte adhesion molecule expression by endothelial cells grown on TCPS or PS is possibly caused by coating of the surfaces with fibronectin. It is known that surface hydrophilicity influences protein adsorption. Although this had no or little effect on leukocyte adhesion molecule expression, endothelial cell growth was affected, because proliferation was slower on the hydrophobic PS. © 2003 Wiley Periodicals Inc. J Biomed Mater Res 65A: 51–59, 2003
Anisotropic properties of tracheal smooth muscle tissue
Authors: Sarma P. A. , Pidaparti R. M. , Meiss R. A. 
Published: March 2003

AbstractThe anisotropic (directional‐dependent) properties of contracting tracheal smooth muscle tissue are estimated from a computational model based on the experimental data of length‐dependent stiffness. The area changes are obtained at different muscle lengths from experiments in which stimulated muscle undergoes unrestricted shortening. Then, through an interative process, the anisotropic properties are estimated by matching the area changes obtained from the finite element analysis to those derived from the experiments. The results obtained indicate that the anisotropy ratio (longitudinal stiffness to transverse stiffness) is about 4 when the smooth muscle undergoes 70% strain shortening, indicating that the transverse stiffness reduces as the longitudinal stiffness increases. It was found through a sensitivity analysis from the simulation model that the longitudinal stiffness and the in‐plane shear modulus are not very sensitive as compared to major Poisson's ratio to the area changes of the muscle tissue. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 1–8, 2003
Casein and soybean protein‐based thermoplastics and composites as alternative biodegradable polymers for biomedical applications
Authors: Vaz C. M. , Fossen M. , van Tuil R. F. , de Graaf L. A. , Reis R. L. , Cunha A. M. 
Published: March 2003

AbstractThis work reports on the development and characterization of novel meltable polymers and composites based on casein and soybean proteins. The effects of inert (Al2O3) and bioactive (tricalcium phosphate) ceramic reinforcements over the mechanical performance, water absorption, and bioactivity behavior of the injection‐molded thermoplastics were examined. It was possible to obtain materials and composites with a range of mechanical properties, which might allow for their application in the biomedical field. The incorporation of tricalcium phosphate into the soybean thermoplastic decreased its mechanical properties but lead to the nucleation of a bioactive calcium‐phosphate film on their surface when immersed in a simulated body fluid solution. When compounded with 1% of a zirconate coupling agent, the nucleation and growth of the bioactive films on the surface of the referred to composites was accelerated. The materials degradation was studied for ageing periods up to 60 days in an isotonic saline solution. Both water uptake and weight loss were monitored as a function of the immersion time. After 1 month of immersion, the materials showed signal of chemical degradation, presenting weight losses up to 30%. However, further improvement on the mechanical performance and the enhancement of the hydrolytic stability of those materials will be highly necessary for applications in the biomedical field. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 60–70, 2003
Local induction of calcium phosphate formation on TiO2 coatings on titanium via surface treatment with a CO2 laser
Authors: Moritz N. , Jokinen M. , Peltola T. , Areva S. , Yli‐Urpo A. 
Published: March 2003

AbstractSol–gel‐derived TiO2 coatings are known to promote bonelike hydroxyapatite formation on their surfaces in vitro and in vivo. Hydroxyapatite integrates into bone tissue. In some clinical applications, the surface of an implant is simultaneously interfaced with soft and hard tissues, so it should match the properties of both. A new method is introduced for treating the coatings locally in a controlled manner. The local densification of sol–gel‐derived titania coatings on titanium substrates with a CO2 laser was studied in terms of the in vitro calcium phosphate‐inducting properties. CO2‐laser‐treated multilayer coatings were compared with furnace‐fired coatings prepared with the same recipe and previously shown to be bioactive. Additionally, local areas of furnace‐fired multilayer coatings (previously shown to be bioactive in vitro) were further laser‐treated to achieve various properties in the same implant. Topological surface properties were examined with atomic force microscopy. The formation of hydroxyapatite was studied with Fourier transform infrared and scanning electron microscopy energy‐dispersive X‐ray analysis. The results show that calcium phosphate formation can be adjusted locally by laser treatment. Calcium phosphate is a bonelike hydroxyapatite. The local treatment of sol–gel‐derived coatings with a CO2 laser is a promising technique for creating implants with various properties to interface different tissues and a possible way of coating implants that do not tolerate furnace firing. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 9–16, 2003
Biphasic materials for bone grafting and hyperthermia treatment of cancer
Authors: Arcos D. , del Real R. P. , Vallet‐Regí M. 
Published: March 2003

AbstractThree biphasic materials have been synthesized from a magnetic glass–ceramic (Si‐Ca‐Fe) and a bioactive sol–gel glass (Si‐P‐Ca). The ratios of glass–ceramic:sol–gel glass used in this work were 1:1, 2:1, and 5:1. These materials show bioactive and magnetic properties and can be used as thermoseeds for hyperthermia treatment of bone tumors. The sol–gel glass content affects the textural properties of the glass–ceramic, giving rise to porosity, which plays a fundamental role in the formation of an apatite‐like layer on the surface. On the other hand, as the sol–gel glass content increases, the magnetic properties change due to the diffusion of Fe ions to the glassy phases of the biphasic materials. The biphasic nature of these materials allows the changing of both properties, depending on the requirements of the patient. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 71–78, 2003