bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro corrosion study by EIS of an equiatomic NiTi alloy and an implant quality AISI 316 stainless steel
Authors: Rondelli G. , Torricelli P. , Fini M. , Rimondini L. , Giardino R. 
Published: July 2006

AbstractThe electrochemical impedance spectroscopy (EIS) technique was used for the study of the electrochemical behavior of an equiatomic NiTi alloy and an implant quality AISI 316 stainless steel type ASTM F138. Experiments were carried out using four different different test solutions: phosphate buffered saline (PBS), Dulbecco minimum essential medium (MEM), MEM + fetal calf serum (FCS), and MEM + fetal calf serum + fibroblast cell (CELL). Specimens were finished to 600‐grit SiC paper and were tested in conditions that did not provoke abrupt mechanical damage of the passive film. Bode‐phase spectra showed the presence of two maxima and were fitted with an equivalent circuit characterized by two parallel combinations (R, resistance; CPE, constant phase element). The R1 and CPE1 branch was assigned to the inner compact passive film and the R2 and CPE2 branch to the external porous film. The resistance of the inner film R1, roughly corresponding to the polarization resistance (Rp), which is inversely proportional to the material's corrosion rate, increased with the immersion time and was generally greater in PBS than in other media. With the exception of FCS solution, R1 for NiTi alloy is better or similar to that of ASTM F138. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Characteristic comparison of bioactive scaffolds based on polyhydroxyalkoanate/bioceramic hybrids
Authors: Zheng Yudong , Wang Yingjun , Yang Huai , Chen Xiaofeng , Chen Zhonghua 
Published: July 2006

AbstractIn this study, bioactive hybrid scaffolds were prepared by combining poly(β‐hydroxybutyrate‐co‐β‐hydroxyvalerate) (PHBV) with three kinds of bioceramics, which are sol–gel bioglass (SGBG), tricalcium phosphate (TCP), and hydroxyaptite. The bioactivity and biodegradation of various scaffolds were analyzed with simulated experiments in vitro by immersing the scaffolds into simulated body fluid to evaluate their biomineralizing ability. The changes of the surface components and structures were determined by FTIR, XRD, and SEM analyses. Cell cultures and observation were made in vitro to assess the proliferation of osteoblast on these scaffolds. The results show that there might be ion exchanges and biodegradation reactions occurring between the hybrids and simulated body fluid solution, which result in the weight loss of the scaffolds and the pH changes in solution. An obvious biomineralized deposit layer was formed on the surface of the PHBV/SGBG and PHBV/TCP scaffolds, which was determined to be the bonelike crystalline hydroxyl‐carbonate‐apatite. The experiments on cell culture show that osteoblast could grow and proliferate on the bioactive hybrid scaffolds. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
The effect of nanofiller on the opacity of experimental composites
Authors: Kim Jong‐Jin , Moon Hyun‐Jung , Lim Bum‐Soon , Lee Yong‐Keun , Rhee Sang‐Hoon , Yang Heong‐Cheol 
Published: July 2006

AbstractThe purpose of this study was to evaluate the effect of the nanofiller in experimental composites on opacity (contrast ratio). Thirteen experimental composites were prepared with three different sizes of fillers: barium glass minifiller (1 μm; 69–76 wt %), silica microfiller (0.04 μm; 0–6 wt %), and silica nanofiller (7 nm; 0–7 wt %). After disk‐type specimens were irradiated with a halogen light curing unit at 500 mW/cm2 for 30 s, the specimens were aged for 6 h at room conditions and were stored in deionized water for 1, 7, 14, 21, 28, 56, and 84 days. The contrast ratios of the specimens were measured as a function of aging period using a spectrophotometer. The distribution morphology of the filler particles in the resin matrix was also examined using energy‐filtering transmission electron microscopy. The experimental composites that contained more than 3% nanofiller had significantly lower contrast ratios (p < 0.05). The composites that contained 6 wt % nanofiller had contrast ratios 34–65% lower than the composite that did not contain nanofiller. The values of the contrast ratio from the composites that excluded microfiller were lower than the values from the composites that included microfiller. From the comparison with the 3 different sizes of filler, the contrast ratio of the composite that contained 70 wt % minifiller and 6 wt % microfiller was the highest, the contrast ratio of the composite that contained only 76 wt % minifiller was the median value, and the contrast ratio of the composite that contained 70 wt % minifiller and 6 wt % nanofiller was the lowest. When the microfiller content was decreased from 6 wt % to 0 wt %, the contrast ratio decreased 6–9%. Energy‐filtering transmission electron microscopy images indicated that the contrast ratio of experimental composites is related to the distribution morphology of the filler particles in the resin matrix. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Fracture of titanium plates used for mandibular reconstruction following ablative tumor surgery
Authors: Martola Martta , Lindqvist Christian , Hänninen Hannu , Al‐Sukhun Jehad 
Published: July 2006

AbstractPurposeThe purpose of this study was to identify reasons for fracture of titanium mandibular reconstruction plates, when used to bridge lateral mandibular defects after ablative tumor surgery.Materials and MethodsSixteen titanium reconstruction plates from sheep mandibles were examined to identify reasons for the plate fractures. The broken plates and the seemingly unbroken plates were examined separately. The plates were removed from the mandibular bone and inspected by dye penetrant examination, metallography, optical microscope, scanning electron microscope, and energy dispersive X‐ray spectrometer. Furthermore, axial load fatigue tests were performed in two different environments, air and physiologic salt solution, 0.9% NaCl, to compare titanium behavior in air and the human body.ResultsThe site of crack initiation was the inner curvature of the reconstruction plate, and the cracks initiated as a result of stress concentration in the shoulder fillet of the plate. The cracks grew in a cyclic manner under masticatory loading of the mandible and the plate. The plate fracture occurred by means of fatigue. The corrosive environment did not affect the failure of the titanium plate, and the fracture was not caused by hydrogen embrittlement. The results revealed that the fatigue properties of the plates may have been impaired by the residual stresses generated in plate bending.ConclusionsAdjustive bending of the plates, in the surgical operation, may thus be an important cause of fracture of the reconstruction plates, because of generated residual stresses, which affect the mean stress in fatigue loading. To make the plates function without failure the plates should match closely with the three‐dimensional shape of the mandible, to avoid any bending in the operative phase. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Effects of chitosan solution concentration and incorporation of chitin and glycerol on dense chitosan membrane properties
Authors: Dallan Paula Rulf Marreco , da Luz Moreira Patrícia , Petinari Leandro , Malmonge Sônia Maria , Beppu Marisa Masumi , Genari Selma Candelária , Moraes Angela Maria 
Published: July 2006

AbstractThe aim of this work was to perform a systematic study about the effects induced by chitosan solution concentration and by chitin or glycerol incorporation on dense chitosan membranes with potential use as burn dressings. The membrane properties analyzed were total raw material cost, thickness, morphology, swelling ratio, tensile strength, percentage of strain at break, crystallinity, in vitro enzymatic degradation with lysozyme, and in vitro Vero cells adhesion. While the use of the most concentrated chitosan solution (2.5% w/w) increased membrane cost, it also improved the biomaterial mechanical resistance and ductility, as well as reduced membrane degradation when exposed for 2 months to lysozyme. The remaining evaluated properties were not affected by initial chitosan solution concentration. Chitin incorporation, on the other hand, reduced the membranes cost, swelling ratio, mechanical properties, and crystallinity, resulting in thicker biomaterials with irregular surface more easily degradable when exposed to lysozyme. Glycerol incorporation also reduced the membranes cost and crystallinity and increased membranes degradability after exposure to lysozyme. Strong Vero cells adhesion was not observed in any of the tested membrane formulations. The overall results indicate that the majority of the prepared membranes meet the performance requirements of temporary nonbiodegradable burn dressings (e.g. adequate values of mechanical resistance and ductility, low values of in vitro cellular adhesion on their surfaces, low extent of degradation when exposed to lysozyme solution, and high stability in aqueous solutions). © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Effect of different γ‐irradiation doses on cytotoxicity and material properties of porous polyether‐urethane polymer
Authors: Haugen H. J. , Brunner M. , Pellkofer F. , Aigner J. , Will J. , Wintermantel E. 
Published: July 2006

AbstractBiomaterials respond to sterilization methods differently. Steam sterilization might decrease the performance of thermoplastic polyether‐urethane (TPU); however, the effect of different γ‐radiation doses on this polymer is contradictory in present literature. The purpose of this study was to investigate the differences between irradiative doses in comparison with steam sterilization on a porous TPU scaffold produced by a new processing method. No significant differences in the surface chemical structure were found with attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR) analysis when comparing with the sterilization methods. The molecular weight (Mw) had a net increase from 11.5 ± 0.039 to 13.2 ± 0.072 kDa by γ‐sterilization from 10 to 60 kGy. The samples that were irradiated (>60 kGy) had also an increase in polydispersity index (PDI; 1.45 ± 0.007) in comparison with the nonsterile ones (1.31 ± 0.017), which indicate branching. Liquid chromatography/mass spectroscopy (LC/MS) analysis showed that there was a correlation between the concentration of the breakdown product, methyl dianiline, and cytotoxicity. The concentration of this compound was found to be four times higher in steam‐sterilized sample (1.3 ± 0.01 ppb) compared with that of the polymer sample γ‐sterilized at 10 kGy (0.3 ± 0.01 ppb). The cytotoxicity of TPU was found to decrease with higher radiation doses, and was significantly higher for the steam‐sterilized samples. It is recommended that TPU produced with the described foaming method should be sterilized by γ‐irradiation at 25 kGy or higher doses. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Effect of biopassive and bioactive surface‐coatings on the hemocompatibility of membrane oxygenators
Authors: Zimmermann Anja K. , Weber Norbert , Aebert Hermann , Ziemer Gerhard , Wendel Hans P. 
Published: July 2006

AbstractPostoperative complications associated with cardiopulmonary bypass (CPB) surgery and extracorporeal circulation (ECC) procedures are still a major clinical issue. Improving the hemocompatibility of blood contacting devices used for ECC procedures may ameliorate various postpump syndromes. In a simulated CPB model using human blood, we investigated the hemocompatibility, fibrinogen adsorption, and platelet receptor (GPIIb‐IIIa) binding capacity of surface‐modified membrane oxygenators (Jostra Quadrox). Three groups were compared: (i) biopassive protein coatings (SafeLine®), (ii) bioactive heparin coatings (BioLine®), and (iii) noncoated controls. During the 2 h recirculation period, plasma concentrations of activation markers for platelets (β‐thromboglobulin), inflammation (elastase), complement (C5a), and coagulation (prothrombin fragment 1+2, thrombin–antithrombin III) were lower in the groups with biopassive and bioactive coatings compared to the noncoated group (p < 0.01). These parameters did not significantly differ between the two surface‐coated groups, except for complement activation: C5a levels were higher in the biopassive group compared to the bioactive group (p < 0.01). Moreover, surface‐coated oxygenators showed less fibrinogen adsorption, GPIIb‐IIIa binding, and platelet/leukocyte adhesion (p < 0.01). We assume that fewer fibrinogen and platelet receptor molecules bound to the surface‐coated oxygenator surfaces results in fewer platelet adhesion and activation, which will significantly contribute to the improved hemocompatibility of the biopassive and bioactive oxygenators. Our results suggest that the application of bioactive oxygenators (BioLine®) during CPB surgery may reduce postoperative complications for the patient more effectively than biopassive oxygenators (SafeLine®). © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Behavior of the different implant materials in acute infection and efficacy of antibiotherapy: Experimental study in rats
Authors: Silistreli Özlem Karatas̨ , Çapar Mustafa , Ulusal Betul Gozel , Ekinci Nes̨e , Aytug Zeynep , Öztan Yücel 
Published: July 2006

AbstractIn this study, we propose a comparison of the behaviors of four different implant materials in case of acute infection: expanded polytetrafluoroethylene (e‐PTFE), porous high density polyethylene (PHDPE), silicone, and autogenous cartilage tissue. The efficacy of prophylactic and therapeutic antibiotic therapies was also investigated in a rat model as four groups: group A, acute infection and no antibiotic therapy (n = 24); group B, acute infection and prophylactic antibiotic therapy (n = 24); group C, acute infection and therapeutic antibiotic therapy (n = 24); and control, no infection and no antibiotic therapy (n = 24). All materials with dimensions of ∼1 × 1 cm2 diameter were implanted separately under the dorsal skin of rats. Staphylococcus aureus was used as the infectious agent and antibiotic therapy was done with seftriaxone (Desefin™, I.M., 20 mg/kg/day). Tissue specimens were obtained on postoperative days 14 and 21. Semiquantitative and qualitative alterations existing in the connective tissue neighboring the implant material (reaction zone‐capsule tissue), fixation to the host tissue, cellular ingrowth (interstice qualitatively), and infection signs were assessed either macroscopically or microscopically. In group A, all materials were affected negatively that led to continuous regression in the wound healing process. Fixation of the cartilage to the surrounding tissue was weak compared with other groups. Fibrovascular tissue ingrowth in porous implants was delayed, and no regular capsule formation was observed around silicone implants. In group B, outcomes were similar to control groups. Porous materials showed tissue ingrowth into the pores as good as the control group. Regular capsular tissue formed around the silicone implants and cartilage tissues. In group C, where silicone had been used, wound healing was not as good as in group B and the control group. In the e‐PTFE group, the granulation tissue forming through the pores did not show a good quality as the control group, and capsule formation around the material was irregular, leading to insufficient fixation. While the wound healing properties of the PHDPE group were not as good as the control group, there was no difference in terms of fixation to the wound bed. On the other hand, wound healing of the cartilage group was as satisfying as the control group. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Enhanced biological treatment of spent metalworking fluids by prior removal of a polymer
Authors: Connolly Helen E , van der Gast Christopher J , Wylie Doug , Stephenson Tom , Thompson Ian P 
Published: July 2006

AbstractThe biological treatment of spent synthetic metalworking fluid (MWF) has been investigated in many studies, with most reporting the presence of undegraded components in the residual waste. In this study a hybrid approach to waste treatment of spent MWF, involving both physical treatment and microbial degradation, was investigated. The effect of the removal of a synthetic polymer on biological degradation was investigated in a bioreactor system. Polymer removal was found to have little effect on the degradation efficiency of the remaining components but resulted in a waste product with 14% lower chemical oxygen demand. An additional benefit of this approach is that it enables the possibility of recycling of the recovered components, with the aim of economising on future product formulation and reducing waste discharge. Copyright © 2006 Society of Chemical Industry
Anaerobic biodegradation of two‐phase olive mill solid wastes and liquid effluents: kinetic studies and process performance
Authors: Borja Rafael , Rincón Bárbara , Raposo Francisco 
Published: July 2006

AbstractThe new two‐phase olive oil mills produce three identifiable and separate waste streams, namely (1) the wash waters from the initial cleansing of the fruit, (2) the aqueous solid residues from the primary centrifugation and (3) the wash waters from the secondary centrifugation. As well as offering process advantages, they also consume less water. Therefore the solid residue, two‐phase olive mill solid waste (OMSW), has a high organic matter concentration, giving it an elevated polluting load, and cannot be easily handled by traditional technology which deals with the conventional three‐phase olive cake. In addition, the new two‐phase olive mill effluents (TPOME) are made up of a mixture of effluents (1) and (3), the total volume of TPOME generated being ∼0.25 dm3 kg−1 olives processed. This review aims to report the main features and characteristics of two‐phase OMSW and TPOME as compared with the classical olive cake and olive mill wastewater (OMW) derived from the three‐phase manufacturing process. The advantages and disadvantages of the two‐phase decanting process are summarised. The anaerobic digestibility of two‐phase OMSW using different influent substrate concentrations is reported. Kinetic studies of anaerobic digestion of two‐phase OMSW are also reviewed and summarised, as well as mass balances to predict the behaviour of the reactor and simplified kinetic models for studying the hydrolysis, acidogenic and methanogenic steps of one‐ and two‐stage anaerobic digestion of OMSW. The review also includes the following: assays of anaerobic digestion of wastewaters from the washing of olives, of olive oil and the two together using fluidised beds and hybrid reactors; the kinetics, performance, stability, purification efficiencies and methane yield coefficients. Copyright © 2006 Society of Chemical Industry
Use of an electric field‐assisted biosorption process in the removal of hazardous or precious ionic species from wastewater streams
Authors: Nomikou Nikolitsa , Hughes Paul , McHale Anthony P 
Published: July 2006

AbstractUse of an electric field‐assisted biosorption system to remove and recover toxic or precious entities from solution is described. The biosorbent materials are housed in a membrane‐enclosed space together with an electrode and a counter electrode is placed in the external solution containing the relevant sorbate. The system is shown to be capable of removing toxic entities such as Cd, Cs, Cu and Cr from solution and additionally is shown to be capable of recovering precious species such as Ag and Pt from relatively dilute solutions. In addition, the potential diversity of application of the system is demonstrated by the efficient sequestration of hazardous organic entities such as glyphosate and phthalate from dilute solutions. Copyright © 2006 Society of Chemical Industry
Investigation of cellulose convertibility and ethanolic fermentation of sugarcane bagasse pretreated by wet oxidation and steam explosion
Authors: Martín Carlos , González Yosmel , Fernández Teresa , Thomsen Anne Belinda 
Published: July 2006

AbstractSugarcane bagasse was pretreated by wet oxidation (WO) at 195 °C for 15 min under either alkaline, neutral or acidic conditions, and by steam explosion (STEX) at 205 °C for 10 min. Alkaline WO was more favourable than neutral and acidic WO for the following enzymatic hydrolysis of cellulose, giving 792 g kg−1 glucose yield after 48 h. The enzymatic hydrolysis of the fibres in the whole slurry was inhibited by inhibitory compounds contained in the prehydrolysate in comparison with the hydrolysis of the washed solid fibres in buffer. The inhibition increased proportionally with formic acid concentration in the pretreated liquid fraction. Cellulose conversion was higher for simultaneous saccharification and fermentation (SSF) than for separate hydrolysis. The highest SSF conversion (829 g kg−1) was obtained for the material treated by alkaline WO. The fermentability of the prehydrolysates by Saccharomyces cerevisiae was evaluated. Stronger inhibition of ethanolic fermentation was observed in the prehydrolysate obtained by steam explosion. The inhibition was more noticeable for the volumetric productivity than for the ethanol yield. The volumetric productivity was reduced by 94.5 and 91.2% for STEX and WO, respectively, whereas the ethanol yield was reduced only by 45.2 and 31.0%, correspondingly, for STEX and WO. Furan aldehydes seemed to be mainly responsible for the inhibition of the fermentation. Copyright © 2006 Society of Chemical Industry
Lipase‐catalyzed dynamic hydrolytic resolution of (R,S)‐2,2,2‐trifluoroethyl α‐chlorophenyl acetate in water‐saturated isooctane
Authors: Wen Wen‐Yen , Ng I‐Sin , Tsai Shau‐Wei 
Published: July 2006

AbstractThe hydrolytic resolution of (R,S)‐2,2,2‐trifluoroethyl α‐chlorophenylacetate in water‐saturated isooctane containing Lipase MY(I) at 35 °C is selected as the best reaction condition for producing (R)‐α‐chlorophenyl acetic acid. The kinetic constants, and hence an enantiomeric ratio of 33.6, are estimated and employed for the modeling of time‐course conversions of both substrates by considering product inhibition and enzyme deactivation effects. A successful dynamic kinetic resolution is also achieved, giving the desired (R)‐α‐chlorophenylacetic acid of 93.0% yield and eeP = 89.5% when 80 mmol dm−3 trioctylamine acting as the racemization catalyst and enzyme activator is initially added. Copyright © 2006 Society of Chemical Industry