bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixed mode fracture characterization of hydroxylapatite–titanium alloy interface
Authors: Mann Kenneth A. , Edidin Avram A. , Kinoshita Roy K. , Manley Michael T. 
Published: May 2005

AbstractCantilever beam and four‐point bend specimen geometries were used to experimentally determine the critical energy release rates for a plasma sprayed hydroxylapatite‐titanium alloy (HA–Ti alloy) interface. A locus of energy release rates as a function of crack tip phase angle was determined where a 0° phase angle represented tensile opening (mode I) loading and a 90° phase angle represented in‐plane shear (mode II) loading. Energy release rates were found to increase substantially with an increase in phase angle. An energy release rate of 0.108 N/mm was determined for a phase angle of 0° (mode I). Energy release rates of 0.221, 0.686, and 1.212 N/mm were determined for phase angles of 66°, 69°, and 72°, respectively. The experimental data was matched to a phenomenological model for which crack propagation depended on mode I loading alone indicating that crack propagation at the Ha‐Ti alloy interface is dominated by the mode I loading alone indicating that crack propagation at the Ha–Ti alloy interface is dominated by the mode I loading component. Therefore, regions of HA coated implants that experience compressive or shear loading across the HA–Ti alloy interface may be much less likely to debond than regions that experience tensile loading. © 1994 John Wiley & Sons, Inc.
Load transfer through a hydroxyapatite‐coated canine hip implant
Authors: Szivek J. A. , Kersey R. C. , De Young D. W. , Ruth J. T. 
Published: May 2005

AbstractStrain transfer near hydroxyapatite (HA) coated canine hip implants was examined using simulated anatomical loading based on in vivo strain measurements. Strain changes near implants relative to intact control values were in excess of 100% for transverse and principal strains for zero time period (immediate postimplant) specimens. They were generally smaller (100% or less) for axial, transverse, and principal minimums in the same locations for 4 months postimplantation specimens.Cortical bone loss occurred in all implanted femora. The most extensive loss, up to 47%, occurred adjacent to the proximal section of the implant. Extensive trabecular bone formation, over 300% in some regions of each femur, was noted in all implanted femora.Backscattered electron imaging along the HA‐coated sections of the implants showed extensive bone bonded to the coating. Normal light and UV light micrographs showed direct bone apposition to the implant surfaces and extensive bone formation in all test animals. Microscopy revealed no evidence of any soft tissue layer between the implant and bone. Bone was typically found in direct contact with the implant surface.Histomorphometry indicated that bone formation rates in the implanted femora were elevated, up to 850%, relative to controls. Fewer formation sites were noted on the posterior and lateral (in two cases zero sites). Mineral apposition rates (MAR) from two of the dogs were slightly elevated (from 110–113%) in the implanted femora relative to controls and depressed (to about 83% of controls) in a third. © 1994 John Wiley & Sons, Inc.
Mechanical properties of vacuum‐mixed acrylic bone cement
Authors: Lewis Gladius , Ed Austin G. 
Published: May 2005

AbstractThe thrust of the present work was the experimental determination of the uniaxial static compressive and fully reversed tension‐compression fatigue properties of CMWTM 3 acrylic bone cement whose consituents were mixed in a properietary chamber while simultaneously subjected to a vacuum. Selected indices of performance in this material are: mean static compressive strength, 81.4 MPa; mean compressive modulus of elasticity, 1.95 GPa; endurance limit, 8.1 MPa; and characteristic fatigue life (using a three‐parameter Weibull fit to the fatigue test data obtained at a stress of ±10 MPa), 238 712 cycles. The difficulties in comparing results obtained using different cement formulations, preparation conditions, and test conditions are detailed. With this in mind, it is suggested that the present results are within the range of values reported by previous workers for other formulations mixed using a variety of methods. The clinical significance of the present results is discussed. © 1994 John Wiley & Sons, Inc.
Use of a compact sandwich specimen to evaluate fracture toughness and interfacial bonding of bone
Authors: Wang Xiaodu , Lankford Jim , Agrawal C. Mauli 
Published: May 2005

AbstractThe objective of the present study was to develop a reliable and statistically valid test to measure the fracture toughness of small specimens of bone, and by extension, prosthetic materials, using a compact sandwich specimen. Samples of bone were sandwiched between holders of a different material and using this specimen configuration a new technique was developed to test the fracture toughness of the bone interlayer. The effects of different speciments sizes and holder materials were investigated empirically. Using finite element analysis a correction factor was determined to account for the finite thickness of the interlayer and the analytical solutions governing the test specimen were accordingly modified. Bulk compact tension specimens of bone were tested for comparison. Both wet and dry bone were evaluated and the fracture surface morphology characterized using scanning electron microscopy. The results indicate no statistically significant differences between the fracture toughness values obtained from the compact tension and sandwich specimens. The application of this technique to the testing of interfacial bonding between bone and biomaterials is discussed. © 1994 John Wiley & Sons, Inc.
Apatite coated on organic polymers by biomimetic process: Improvement in its adhesion to substrate by NaOH treatment
Authors: Tanahashi Masami , Yao Takeshi , Kokubo Tadashi , Minoda Masahiko , Miyamoto Takeaki , Nakamura Takashi , Yamamuro Takao 
Published: May 2005

AbstractA dense, uniform and highly biologically active bone‐like apatite layer can be formed in arbitrary thickness on any kind and shape of solid substrate surface by the following biomimetic method at ordinary temperature and pressure. First, a substrate is set in contact with particles of bioactive CaO SiO2 based glass soaked in a simulated body fluid (SBF) with inorganic ion concentrations nearly equal to those of human blood plasma. Second, the substrate is soaked in another solution with ion concentrations 1.5 times those of SBF (1.5 SBF). In the present study, organic polymer substrates treated with 5 M NaOH solution were subjected to the above mentioned biomimetic process. The induction periods for the apatite nucleation on polyethyl‐eneterephthalate (PET), polymethylmethacrylate (PMMA), polyamide 6 (PA6), and polyethersulfone (PESF) substrates were reduced from 24 to 12 h with the NaOH treatment. The adhesive strength of the formed apatite layer were increased from 3.5 to 8.6 MPa, from 1.1 to 3.4 MPa, and from 0.6 to 5.3 MPa with the NaOH treatment, for PET, PMMA, and PA 6, respectively. It was assumed that highly polar groups, such as carboxyl and sulfinyl ones formed by the hydrolysis of an ester group on PET and PMMA and of an amide group on PA 6, or of a sulfonyl group on PESF with the NaOH treatment, attached a large number of hydrated silica dissolved from the glass particles, to accelerate the apatite nucleation, and also to form a strong bond with the apatite. The apatite‐organic polymer composites thus obtained are expected to be useful as bone‐repairing as well as soft tissue‐repairing materials. © 1994 John Wiley & Sons, Inc.
Improved sensitivity and decreased sample size in a cytotoxicity test for biomaterials: A modified colony microassay using a microplate and crystal violet staining
Authors: Tsuchiya Toshie , Ikarashi Yoshiaki , Arai Tadashi , Ohhashi Jyunichi , Nakamura Akitada 
Published: May 2005

AbstractModified Eagle's minimum essential medium supplemented with 5% fetal calf serum was highly sensitive to cytotoxicity and formed large control colonies in the V79 colony assay. A highly sensitive cytotoxicity test was developed using 96‐well microtiter plates. Test chemicals or extracts of polyurethane materials containing the same chemicals were added 24 h after inoculation of cell suspensions. The cells were fixed and stained with crystal violet after additional culture for 6 days (V79 cells) or 10 days (Balb/3T3 cells). In terms of sensitivity and rapid quantitative measurement, this modified colony microassay, using a low cell density in 96‐well microplates, was superior to various cytotxicity tests such as colony, growth inhibition, cytolethality, and agar diffusion assays. © 1994 John Wiley & Sons, Inc.
Effectiveness of cleaning surgical implants: Quantitative analysis of contaminant removal
Authors: Rowland Shane A. , Shalaby Shalaby W. , Latour Robert A. , Von Recum Andreas F. 
Published: May 2005

AbstractSurgical implants need to be free from contaminants before implantation. The effectiveness of a presently used Clemson bioengineering cleaning (CBC) protocol was evaluated for cleaning three different biomaterials (titanium, aluminum oxide, and polyethylene terephthalate, PET) contaminated with three different contaminants (calcium chloride, zinc chloride, and hexadecane). Radiolabeled tracer analysis (RTA), with the use of liquid scintillation, was used as the surface analytical technique to quantitatively determine the removed from the biomaterial surface. On average, the ultrasonic cleaning step removed 99.96% of all three contaminants from both titanium and aluminum oxide. The CBC protocol did not sufficiently clean PET fabric contaminated with hexadecane leaving 11.76% of the contaminant after the ultrasonic step. With the use of isopropyl alcohol in series with 1% Liquinox, the ultrasonic step cleaned the fabric soiled with hexadecane within 30 min, removing 99.85% of the hexadecane initially on the surface. RTA proved to be an excellent method of quantifying surface contamination on implant materials, and for assessing the effectiveness of cleaning protocols in question. © 1995 John Wiley & Sons, Inc.
A quantitative technique for reporting surface degradation patterns of UHMWPE components of retrieved total knee replacements
Authors: Cornwall G. Bryan , Bryant J. Tim , Hansson Carolyn M. , Rudan John , Kennedy Lloyd A. , Cooke T. Derek V. 
Published: May 2005

AbstractA quantitative method of reporting surface degradation of the ultra‐high molecular weight polyethylene (UHMWPE) tibial component from retrieved total knee replacements (TKR) was developed. Specific features include a qualitative assessment expressing the patterns in which the damage was detected as well as a quantitative summary of the observed degradation mechanisms. In addition, a method of measuring lower limb alignment changes with time is described and related to the observed damage patterns. Two case studies are presented. One case illustrated that changes in alignment resulted from factors other than wear. The damage observed on the tibial plateau appeared to occur subsequent to the changes in alignment. The second case illustrated that the wear of the UHMWPE tibial insert lead to the changes in the overall lower limb alignment. The methods described provide additional information regarding TKR failure mechanisms compared to reporting methods currently available. In particular, the collection of temporal alignment data at clinical follow‐up visits enhanced the assessment of the retrieved TKR. © 1995 John Wiley & Sons, Inc.
In vitro cytotoxicity testing of neodymium‐iron‐boron magnets
Authors: Donohue V. E. , McDonald Fraser , Evans R. 
Published: May 2005

AbstractNeodymium‐iron‐boron magnets are being increasingly used in orthodontic and orthopedic appliances. The purpose of this study was to investigate the in vitro cytotoxicity of these new “super” magnets. A modified agar overlay technique was performed using both L929 mouse fibroblasts and adult human oral mucosal fibroblasts. The neodyium‐iron‐boron magnets were tested in the following forms: uncoated magnetized, uncoated demagnetized, parylene coated demagnetized, and parylene coated magnetized. Results revealed that uncoated magnetized, uncoated demagnetized, and parylene coated magnetized were cytotoxic to both L929 mouse fibroblasts and human oral mucosal fibroblasts. However the parylene coated demagnetized neodymium magnets were only cytotoxic to the human mucosal fibroblasts. This study supports the hypothesis that these are cytotoxic effects of possibly corrosion products and of magnetism. The specific toxic effects of parylene were not examined in this present study. Statistical analysis (Mann‐Whitney U‐test, p = 0.014) suggested that, in this experiment, the human oral mucosal fibroblasts were more sensitive to the effects of these rare earth magnets. With the evidence of a biological effect, the use of implanted magnets must at present be limited until the safety can be assured. © 1995 John Wiley & Sons, Inc.
The response of cancellous and cortical canine bone to hydroxylapatite‐coated and uncoated titanium rods
Authors: Rashmir‐Raven A. M. , Richardson D. C. , Aberman H. M. , De Young D. J. 
Published: May 2005

AbstractBecause of the recent trend in total hip arthroplasty to achieve direct contact of the endoprosthesis with cortical bone, comparison of bone apposition from cortical bone and cancellous bone was performed. The response of cortical and cancellous bone to hydroxylapatite was also compared. Implants in cortical bone demonstrated a higher interface shear strength and more bone apposition than those in cancellous bone over all time periods tested. Hydroxylapatite coating increased the interfacial shear and bone apposition in cortical bone at all time periods and in both the 3‐ and 6‐week cancellous bone models. The potential effect of stress shielding (and subsequent bone resorption) by femoral stems ingrown with cortical bone is discussed. © 1995 John Wiley & Sons, Inc.
Modification of polyethylene terephthalate (dacron) via denier reduction: Effects on material tensile strength, weight, and protein binding capabilities
Authors: Phaneuf Matthew D. , Quist William C. , Bide Martin J. , LoGerfo Frank W. 
Published: May 2005

AbstractThrombosis remains a significant and potentially catastrophic complication of polyethylene terephthalate (Dacron) prosthetic vascular graft implantation. Numerous attempts have been made to create a novel surface that reduces the adverse effects of blood interaction with the material. The purpose of this study was to create reactive groups on Dacron without significantly altering the chemical and physical properties of the biomaterial. These groups would then serve as “anchor sites” for covalent attachment of the blood protein albumin to the surface, thus creating a more biocompatible surface. Denier reduction, an established textile chemistry procedure that creates carboxyl groups on the fiber surface via hydrolysis of the material, was performed at 100°C using sodium hydroxide concentrations of 0.5, 1.0, 2.5, and 5.0% (treated materials referred to as 0.5% hydrolyzed etc.). Tensile strength determination of hydrolyzed materials revealed no statistically significant difference in material strength between control, 0.5, and 1.0% hydrolyzed materials; the 2.5 and 5.0% hydrolyzed materials had significant strength loss as compared to the controls. Significant fiber weight loss occurred in the 1.0, 2.5, and 5.0% hydrolyzed Dacron segments. The 0.5% hydrolyzed material did not have any significant weight loss. Covalent linkage of 125I‐albumin to these modified materials using the crosslinker 1‐ethyl‐3‐(3‐dimethyl aminopropyl)‐carbodiimide hydrochloride (EDC) resulted in the 0.5% hydrolyzed material having the greatest protein binding (330 ng/mg Dacron, 2.4‐fold greater than control). Incubation of the 0.5% hydrolyzed material with EDC and various concentrations of 125I‐albumin resulted in the 14.80 m̈M solution permitting the greatest binding per milligram Dacron (330 ng/mg Dacron). Scanning electron microscopy, performed blindly, revealed no change in the 0.5% hydrolyzed Dacron as compared to untreated Dacron. The 5.0% hydrolyzed Dacron, however, had noticeable structural damage on the outer periphery of the fiber surface. Observation of the untreated Dacron with nonspecifically bound albumin showed scattered areas of albumin adherent to the fiber surface whereas covalent linkage of albumin to the 0.5% hydrolyzed Dacron via EDC crosslinking showed numerous albumin moieties on each fiber. This study demonstrates that a clinically accepted biomaterial (Dacron) can be chemically modified, without significantly altering the physical and chemical characteristics of the biomaterial, in order to covalently bind albumin to the fiber surface. Thus, these results serve as foundation for creating potential novel biomaterials without significantly altering the properties of the original biomaterial. © 1995 John Wiley & Sons, Inc.
Determination of volatile halogenated hydrocarbons in tap water, seawater and industrial effluents by glass capillary gas chromatography and electron capture detection
Authors: Eklund Göran , Josefsson Björn , Roos Claes 
Published: May 2005

AbstractA rapid and sensitive method to determine volatile organohalides in different types of waters has been developed. The chromatographic system is based on the resolving power of the glass capillary column and the high sensitivity of the electron capture detector. The capillary columns were connected to the detector so that the eluate from the column is mixed with thermostatted purge gas to minimize band broadening due to dead volumes. The low column bleeding and decreased band spreading from capillary columns enhance the sensitivity to very low levels: 1 fg (10−15g) for carbon tetrachloride, despite dilution of the column eluate by the purge gas.The water samples of 100 ml were extracted with 1 to 10 ml n‐pentane which is the most practical alkane with respect to purity. When using high water to pentane ratios corrections had to be made, due to low extraction yield, to get accurate quantifications.A column with Carbowax 400 stationary phase permits direct tap water injection. The water peak concealed the substances eluated after CHCl3 and CHBrCl2.The gas chromatographic separation of haloforms in tap water could be shortened to 30 seconds using a 10 m SE–52 column with an increased film thickness.Besides tap water and seawater, industrial waste water from a pulp mill was analyzed. Ten different halogenated organic compounds, ranging from 1 ng/I to 760 μg/I, were quantified in the different waters. Bromoform, which had not previously been found in seawater, was detected.Chromatogram of a standard mixture containing 11 organohalides. Stationary phase, SE‐52; 33 m × 0.3 mm i.d. inj. temp. 200°, column temp. 50°, interface 250°, detector temp. 250°. Helium carrier gas flow rate, 36 cm/s, scavenger'gas flow 30 ml/min.Split ratio 1:20, 1 = CH2CI2, 2 = CHC13, 3 = CH3CC13, 4 = CC14, 5 = CHCICCI2, 6 = CHBrCI2, 7 = CBrC13, 8 = CHBr2Cl, 9 = CCl2CC12, 10 = CHCl2l, 11 = CHBr3.
Capillary gas‐liquid chromatography of bile acids: Improvement with on‐column injection
Authors: Kariaganis Georg , Paumgartner Gustav 
Published: May 2005

AbstractAnalysis of trimethylsilylethers of methyl esters of bile acids exhibits high separation efficiency with a 20 m × 0.3 mm glass capillary column covered with a crystal layer of barium carbonate and coated with polyethyleneglycol 20000 as liquid phase [3]. The sensitivity and reproducibility of this method can be further improved by an on‐column injection technique according to Grob et al. [4].
Splitless injection and the solvent effect
Authors: Grob K. , Grob K. 
Published: May 2005

AbstractSplitless injection is based on the solvent effect as a mechanism condensing large vapour clouds down to infinitely shortened bands. The effect is controlled by the parameters column temperature, volatility and amount of solvent, and rate of injection. By properly selecting the variables the effect can easily be optimized for any combination of sample and column. It is the purpose of this paper to provide the mechanistic understanding as required for this optimization, as well as some rules for the experimental realization. Potentialities and limitations of splitless injection are discussed, and the role of the solvent effect in on‐column injection is emphasized.
GC/MS investigations of the constituents in a diethyl ether extract of an acidified roast coffee infusion
Authors: Rahn W. , König W. A. 
Published: May 2005

AbstractA roast coffee infusion (nicaragua arabica) was acidified (pH 1,5) with hydrochloric acid and extracted with diethyl ether in a perforator. After evaporation of the solvent the residue was treated with N‐methyl‐N‐trimethylsilyl trifluoroacetamide and analyzed by glass capillary GC/MS. The main components were identified by their electron impact and isobutane chemical ionization mass spectra. 1,2,4‐trihydroxy benzene, 1‐ethyl‐3, 4‐dihydroxy benzene and 2,3‐dihydroxy toluene were identified as new constituents of roast coffee with possible emetic properties.
Systematic and statistical errors in quantitative evaluation in TLC and HPTLC. 1. Evaluation by graphic methods
Authors: Ebel S. , Hocke J. 
Published: May 2005

AbstractThe paper discusses errors and error propagation in respect of graphic methods in quantitative in situ measurements in TLC. An error of 0.3% is possible by measuring only peak height if optimal conditions are chosen. This is in good agreement with analysis done practically which gives errors in the order of 0.3–0.6%. If the peak area is evaluated using the approximation peak height × half width, the error is in the order of 0.6%, but in real experiments only 1.5% had been found. Systematic errors in determining peak heights are introduced by the time constant of the amplifiers and the recorder.
GLC studies of diffusion of some selected solvents in polypropylene and the calculation of the activation energy of diffusion
Authors: Abushihada A. M. , Shunbo F. E. , Al‐Sultan Y. Y. 
Published: May 2005

AbstractA thorough survey of the past and current available literature shows that the diffusion of the solvents toluene, ethylbenzene, ortho‐, meta‐, and para‐xylenes in polypropylene has not been studied so far, although such studies find practical applications in various industrial problems. Diffusitives and the activation energies of the above mentioned solvents in polypropylene were determined in the temperature range of 45–120°C by gas chromatography. The values obtained in this communication compare fairly with those determined by conventional techniques for analogous systems, confirming the reliability of the gas chromatography as a powerful tool for diffusion measurement and the authenticity of the data presented herein.
The absolute retention index in chromatography. Part 1
Authors: Said A. S. , Hussein F. H. 
Published: May 2005

AbstractA definition for an absolute retention index is given. This index is independent of whether the process is isothermal or temperature programmed. The relation between this index and Kovats's index is discussed. General equations are derived for the retention times of homologous series, from which the position of the air peak or missing members can be determined. Methods used in the literature for air peak determination are improved and extended to other cases of interest. The retention index in temperature programmed chromatography is reexamined in the light of recent publications on temperature programming.