bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of vitamin formulations by electrokinetic chromatography utilizing tetradecylammonium ions as the pseudostationary phase
Authors: Næss Øystein , Tilander Tuija , Pedersen‐Bjergaard Stig , Rasmussen Knut Einar 
Published: May 2005

AbstractA recently proposed method for the separation of fat‐soluble vitamins by electrokinetic chromatography was further developed and investigated in the present study. The separation medium consisted of acetonitrile‐water (80:20 v/v) and contained 80 mM tetradecylammonium bromide (TDA+); the content of acetonitrile served to maintain the hydrophobic vitamins dissolved during electrophoresis, while the TDA+ ions served as the pseudostationary phase. With the cathode placed at the outlet of the capillary, the fat‐soluble vitamins were separated based on different hydrophobic interactions to the TDA+ ions and migrated in order of decreasing hydrophobicity prior to the electroosmotic flow. Migration time stability was significantly enhanced by the addition of 4 mM borate to the separation medium. The separation system was validated for the determination of vitamin E acetate in commercial tablets; quantitative results deviated by less than 3.5% from specified values, varying by less than 2.5% relative standard deviation (RSD) for within‐day experiments, and by less than 6.5% RSD during between‐day experiments. The separation system was compatible with injection solvents ranging in polarity from water to tetrahydrofuran, and was even capable of separating the water‐soluble vitamins B1, B2, B12, and nicotinamide.
Determination of bupivacaine and three of its metabolites in rat urine by capillary electrophoresis
Authors: Schieferecke Mark A. , McLaughlin Kieran J. , Faibushevich Alexander A. , Lunte Craig E. 
Published: May 2005

AbstractA capillary electrophoretic (CE) method for the analysis of urinary extracts of the local anesthetic, bupivacaine, and its three main metabolites, desbutylbupivacaine, 3′‐hydroxybupivacaine, and 4′‐hydroxybupivacaine, in rat urine has been developed. The limits of detection were 0.22 μM for desbutylbupivacaine and bupivacaine, 0.15 μM for 3′‐hydroxybupivacaine, and 0.16 μM for 4′‐hydroxybupivacaine. The linear range was from 0.7 μM to 16.8 μM for all four compounds. Migration time and peak height reproducibilities, and extraction efficiencies were determined for all four compounds. Peak height reproducibilities (n = 5) for the overall method were improved through the use of prilocaine as an internal standard. Peak height reproducibilities were 5.6% RSD for desbutylbupivacaine and bupivacaine, and 9.9% RSD for 3′‐hydroxybupivacaine and 4′‐hydroxybupivacaine. Migration time reproducibilities (n = 5) were 2.4% for all compounds. Urine samples were collected from rats administered therapeutic doses of bupivacaine and extracted using a solid‐phase extraction method (SPE). Separation of bupivacaine and its metabolites was achieved in 15 min.
Determination of atropine in biological fluids by micellar electrokinetic capillary chromatography in the presence of strychnine and tetracaine
Authors: Plaut Olivier , Staub Christian 
Published: May 2005

AbstractThe identification and quantitation of atropine, in whole blood and gastric contents in the presence of strychnine and tetracaine is described. This method uses liquid‐liquid extraction and micellar electrokinetic chromatography (MECC). Separations are made using a 50 cm long capillary and a borate/phosphate buffer at pH 9.2 with 50 mM sodium dodecyl sulfate (SDS). Linearity was established for the three compounds between 1.0 and 100 μ/mL, using scopolamine as internal standard. The limit of detection for atropine was estimated at 0.06 μ/mL and the limit of quantitation at 0.2 μg/mL. The run time is less than 30 min. Alternate parameters are proposed to reduce the run time to under 10 min. The method was applied to a forensic post‐mortem case.
Determination of titanocene, a new drug with anticancer potential, and its metabolism in solution by capillary electrophoresis
Authors: Wittrisch Holm , Schröer Hans‐Peter , Vogt Jürgen , Vogt Carla 
Published: May 2005

AbstractTitanocene dichloride is one of the most promising cancerostatica of the future: nevertheless, its high activity against several tumor cells was discovered 20 years ago. Detailed knowledge of the mechanism of hydrolysis of titanocene dichloride and its stability in the infusion liquid is a prerequisite for clinical tests and for a successful application for permission as medication. Capillary electrophoresis (CE) was used to observe the hydrolysis behavior of titanocene dichloride in aqueous solutions. The hydrolysis products were separated in a 20 mM phosphate buffer, pH 6, and in a 20 mM malic acid buffer, pH 3. Up to five hydrolysis products were obtained. A significant influence of the sample preparation (pH, isoionic additives) on the hydrolysis rate was observed. The hydrolysis products were characterized by the UV scan and the element‐selective particle‐induced X‐ray emission (PIXE) detection technique. The results obtained correspond with the hydrolysis mechanism described in the literature. The determination of free titanocene dichloride in human plasma failed due to the high affinity of the plasma proteins for this compound.
Charged chelate—capillary electrophoresis of endogenous corticosteroids
Authors: Palmer James , Atkinson Shannon , Yoshida Wesley Y. , Stalcup Apryll M. , Landers James P. 
Published: May 2005

AbstractSeparation of endogenous 17‐ or 18‐hydroxylated corticosteroids (of the 21‐hydroxylated 4‐pregnen series) as charged chelates in capillary electrophoresis with borate as the ligand is demonstrated. Aldosterone, 18‐hydroxycorticosterone, 18‐hydroxy‐11‐deoxycorticosterone, cortisone, cortisol, and 11‐deoxycortisol are separated and resolved by 400 mM borate buffer at pH 9.0. Separation characteristics of the corticosteroid charged chelates were examined by varying the separation buffer borate concentration, pH, ionic strength, and addition of organic modifiers. The borate ion [B(OH)4]− is identified as the critical buffer component. Corticosteroids chelate borate with proximal hydroxyls composed of either the 17‐ or 18‐hydroxyl in combination with the 21‐position hydroxyl. Corticosteroid/borate chelation as indicated by CE results is corroborated with 11B‐nuclear magnetic resonance (11B‐NMR) sprectra. Chelation is a readily reversible process, with the strength of the resultant chelate, as opposed to the charge‐to‐mass ratio, predominantly determining analyte mobility in charged chelate ‐ capillary electrophoresis (CC‐CE).
Smoke dilution methods for the evaluation of the smoke emission from burning polymers: A comparative approach
Authors: Ballistreri Alberto , Montaudo Giorgio , Puglisi Concetto , Seamporrino Emilio , Vitalini Daniele 
Published: May 2005

AbstractA comparative approach to the determination of smoke emission from burning polymers has been attempted, and a number of combustion conditions and detection devices have been tried to choose a test method for measuring the smoke proiduction of materials. The combustion apparatus adopted is a hot‐air quartz furnace that permits the measured by dynamic method from combustion of PAN, PVC and PVC mixed with some metal oxiders, have been compared with those obtained by an accumulation mode. For PVC the intensity of the light scattered from the evolving smoke has been measured as an alternative to smoke density.
Customized neonatal incubator for measurement of platelet‐artificial microvascular graft interactions under controlled flow, temperature, and transmural pressure
Authors: Johnson Peter C. , Sheppeck Richard A. , Berceli Scott A. , Borovetz Harvey S. , Bentz Michael L. , Garrett Kevin O. , Janosky Janine E. 
Published: May 2005

AbstractA neonatal incubator has been custom modified to enable measurement of initial platelet retention on biomaterials in vitro under clinically relevant hemodynamic conditions. To calibrate this device, platelet retention on several materials having microconduit geometry (0.7–1.0 mm i.d.) has been measured after perfusion with citrated whole blood (containing 111 Indium‐labelled platelets) at a shear rate of 312 s−1, 37°C, and 80 cm H2O transmural pressure. The relative reactivity of these materials toward platelets was: glass < Fibrinogen(Fg)‐coatedglass < Fg‐coated polyethylene < polyethylene ∼ = Expanded polytetrafluoroethylene. Interindividual variation is relatively large (coefficient of variation = 35.5 ± 9.3%), but comparison to intraindividual controls reduces the variability to 14.8 ± 10.3%, a level which is suitable for economical testing of platelet retention to biomaterials in the presence or absence of drugs. This approach may have particular value in the study of the mechanism of platelet interactions with artificial microvascular grafts under perfusion conditions which are relevant to the first moments of flow, when initial platelet deposition occurs.
Vibrational response analysis: Non‐destructive evaluation of ingrowth into porous coated implants
Authors: George Thomas F. , Abrams Charlie F. , Richardson Daniel C. , Deyoung David J. , Carlson Cathy S. , Meutin Donald 
Published: May 2005

AbstractQuantitative methods of evaluating ingrowth into porous coated implants have traditionally involved destructive mechanical testing. In this study, it was hypothesized that the response to a vibrational stimulus could estimate the shear strength at the bone‐implant interface as measured by pushout. A derived model predicts that the square of the frequency at resonance is linearly related to this interfacial strength. It was further hypothesized that the level of vibration required for a meaningful response would not be destructive. This study was done using nonloaded, porous coated cylindrical implants which were press fit in the distal femora of dogs. Femora were harvested at 2, 4, and 6 weeks postimplantation. The implants were sectioned into 4‐mm slices and then evaluated by vibration, pushout, and light microscopy. Vibrational response analysis was conducted with broad band random excitation using Fast Fourier transform signal analysis. Pushout values were obtained using a materials testing machine. The resulting correlation was statistically significant (F = 201, r2 = 0.90, p < 10−6). Light microscopic evaluation of vibrated samples showed no difference at the bone‐implant interface when compared to controls.
Does vacuum mixing of bone cement affect heat generation? Analysis of four cement brands
Authors: Wang Jian‐Sheng , Franzén Herbert , Toksvig‐Larsen Søren , Lidgren Lars 
Published: May 2005

AbstractFour different brands of bone cement (Palacos R, Simplex P, Sulfix, CMW 1) were tested for exothermic changes during polymerization at atmospheric pressure and under partial vacuum of 0.2 bar. Palacos R was also mixed at four pressure levels (1.0, 0.2, 0.12, and 0.05 bar). The peak temperature in the bone cement was 46 to 124 °C, depending on the measuring point. There was no difference in peak temperature or duration of temperature increase above 50 °C during the curing of cement whether mixed at atmospheric pressure or under partial vacuum at different pressure levels. © 1995 John Wiley & Sons, Inc.
A new method for preparing nonthrombogenic plastic surfaces
Authors: Eriksson Jan Christer , Gillberg Gunilla , Lagergren Hans 
Published: May 2005

AbstractThe present paper describes a new technique for preparing the surface of polyethylene and polypropylene plastics for the adsorption of heparin. The procedure consists of exposing the plastic surface to a solution of cationic surfactants at a temperature close to the softening temperature of the plastic. The mechanism of adsorption of the anticoagulant of the surfaces is discussed.
Preliminary clinical trials of a new oral adhesive bandage
Authors: Scopp Irwin Walter , Heiser Ralph A. 
Published: May 2005

AbstractA new intraoral adhesive bandage composed of gelatin, sodium carboxymethylcellulose, and polyisobutylene backed by a layer of polyethylene film was used by 148 investigators in 1468 patients. The bandage adhered well to the fixed mucosa of the palate, gingiva, and teeth. It adhered less satisfactorily to the loose mucosa of the cheek and floor of the mouth. It did not adhere very well to the tongue. The duration of adhesion of the bandage was at least 5 hr in approximately 87% of all treated cases, and it remained in place for 9–51 hr for more than 50% of all treated patients. Tolerance of the application was good or excellent in 75% of all cases. There was no irritation attributable to the bandage in any patient. The bandage provided an effective means of protecting the vital repair mechanism of a wound during the early hours after extraction. The results of these trials indicate that the new adhesive bandage is safe and that it provides effective cover and protection of wounds and lesions of the mucous surface up to 24 hr.
Tissue reaction after implantation and in situ polymerization of hydrophilic gel
Authors: Hubacek J. , Kliment K. , Dusek J. , Hubacek Jar 
Published: May 2005

AbstractThe authors followed the tissue response of a new plastic tube composed of neutral hydrophilic gel, after implantation in the subcutis of rats. They further studied tissue reaction when gel rods were connected by polymerization in situ. After implantation, the gel tubes developed a fine encapsulation but no inflammatory response. The gel rods were connected “end to end” by means of a drop of the polymerizing mixture. The healing proceeded in the same manner with the exception that minute granules of macrocellular elements were formed in the ligament surrounding the polymerization mixture remnats. According to these results, the neutral hydrophilic gel has proved to be a suitable material for implantation.
Corrosion rate measurements in vivo
Authors: Colangelo V. J. , Greene N. D. , Kettelkamp D. B. , Alexander H. , Campbell C. J. 
Published: May 2005

AbstractCorrosion resistance is particularly important in medical treatments requiring implantation of metallic objects in the human body. Unfortunately, weight loss measurements and other conventional corrosion testing techniques are insufficiently sensitive and difficult to adapt to in vivo environments. The linear polarization technique can be used to remotely meaure the corrosion rates of metals implanted in tissue using needle probes. The principles of this technique are reviewed and the results of tests performed on steel, cobalt, and molybdenum implanted in experimental animals are discussed.
Phenols and blood coagulation
Authors: Nour‐Eldin F. 
Published: May 2005

AbstractThe effect of phenol and certain phenyl compounds on the different stages of the blood coagulation and fibrinolytic mechanism is investigated. Phenol has a complex action on blood coagulation. In an optimal concentration of 0.3% it produced a definite, though suboptimal platelet factor 3 activity, evolved factor XII, accelerated thrombin–fibrinogen interaction, retarded clot retraction, enhanced the action of streptokinase on plasminogen, and inhibited plasmin. In addition, in the absence of factor XIII and calcium, it increased the solubility of fibrin in urea. Phenyl acetaldehyde, benzyl benzoate, and styrene (phenyl ethylene) accelerated stypven clotting time and thrombin–fibrinogen reaction. Unpolymerized styrene and phenyl ethanol specifically inhibited the action of plasma thromboplastin, formed in a system lacking in factor VIII or IX. A study is also reported on the changes responsible for the stabilization with phenol of brain thromboplastic activity. The action is not purely bactericidal, but is dependent on the presence of brain tissue particles in suspension. The contribution of platelets to plasma thromboplastin formation is examined in the light of these investigations, showing the ability of phosphorus‐free compounds to supply a platelet‐like activity.
Segmented polyurethane: A polyether polymer. An initial evalution for biomedical applications
Authors: Boretos John W. , Pierce William S. 
Published: May 2005

AbstractA segmented polyurethane elastomer, originally developed for elastic thread, is now being used for molded prostheses. Chemical, mechanical, and biological properties are described. Hydrolytic stability of this polymer is compared to that of a polyester urethan. Experience with the material used in components of an experimental heart‐assist pump has shown excellent flex endurance, wear resistance, and intravascular acceptability.
Oral and cutaneous tissue reactions to injected fluid silicones
Authors: Nedelman C. I. 
Published: May 2005

AbstractDuring the period covered by this investigation, toxicological studies were carried out in hamsters and rabbits. The results of injections, subcutaneously and in the buccal pouch of hamsters, indicated that the silicones used were nontoxic, non‐absorbable, and well encapsulated by connective tissue elements with moderate tissue reaction. Further studies of various combinations of roomtemperature vulcanizing silastics indicated similar reactions when injected submucosally in the alveolar ridges and palate of rabbits. The injected materials remained in situ in the injected submucosal area and became well encapsulated by the proliferation of connective tissue and collagenous fibers. There was no evidence of macrophages or foreign body giant‐cells in and around the proliferating connective tissue capsule. There were no macroscopic or microscopic signs of tumor formation. The encapsulated masses did not elicit bone resorption when localized adjacent to bone tissue.
Determination of residual ethylene oxide in catheters by gas—liquid chromatography
Authors: Kulkarni R. K. , Bartak D. , Ousterhout D. K. , Leonard Fred 
Published: May 2005

AbstractA quantitative method for determining residual ethylene oxide in plastic and rubber catheters using gas–liquid chromatography has been developed. Tests on ethylene oxide stabilized catheters indicated that the amount of ethylene oxide in the catheters decreased as a function of aeration time up to 48 hr. After this period, a steady concentration of ethylene oxide in the catheters appeared to have been reached up to one week's testing.
α‐Cyanoacrylate adhesive bond strengths with proteinaceous and nonproteinaceous substrates
Authors: Leonard Fred , Hodge J. W. , Houston Stuart , Ousterhout D. K. 
Published: May 2005

AbstractThe higher n‐alkyl α‐cyanoacrylate homologs had been previously found to wet, spread, and rapidly polymerize on tissue substrates whereas the lower homologs do not wet and polymerize slowly. The reverse effect is noted on nonproteinaceous substrates such as distilled water and saline solution. Tissue bonds were prepared and tested in vivo in rats. Bonds prepared with the higher n‐alkyl α‐cyanoacrylate homologs were found to be stronger than those prepared with the lower homologs. The data are in general accord with the wetting and spreading characteristics of the n‐alkyl α‐cyanoacrylate homologs. On aluminum surfaces, the opposite effect was noted. Bonds prepared with the lower homologs were stronger than those prepared with the higher homologs.
Semipermeable aqueous microcapsules (artificial cells). V. Permeability characteristics
Authors: Chang Thomas M. S. , Poznansky Mark J. 
Published: May 2005

AbstractA rapid mixing and sampling technique was used to study the permeability characteristics of semipermeable aqueous microcapsules (artificial cells). Urea, creatine, creatinine, uric acid, glucose, sucrose, and salicylic acid equilibrated rapidly across nylon microcapsules of 207 μ diameter (e.g., T 1/2 for urea of 3.4 sec). From these results the permeability constants were calculated (e.g., P for urea of 2 × 10−4 cm/sec). Very much the same permeability constants were found for collodion microcapsules. The equivalent pore radius of the membrane of the nylon microcapsules were estimated to be 18 A.
Surgical suture–canine tissue interaction for six common suture types
Authors: Homsy C. A. , McDonald K. E. , Akers W. W. , Short C. , Freeman B. S. 
Published: May 2005

AbstractMaximum extraction stress and integrated extraction work were measured for sutures implanted for 3, 7, and 14 day periods. Six common non‐absorbable sutures, representative of braided and monofilamentary forms, were implanted subdermally and were used for cutaneous incision closure with purebred pointer dogs. The data show: (1) Braided sutures, polyester/Teflon, silk‐type B, and silk–silicone interacted with peripheral tissue to a significantly greater degree than the monofilamentary types, nylon, polypropylene, and polyethylene; (2) polyester–Teflon braided suture interacted to a lesser degree than the other braided sutures; (3) the relatively intense interaction of plain silk and silicone‐treated silk appears to reflect the combined effects of mechanical aspects of braiding and of biochemical response; and (4) all braided sutures swelled over the implantation periods with as much as a 70% increase in diameter after 14 days for silk.
Enzyme entrapment within hydrophobic and hydrophilic matrices
Authors: Brown Harry Darrow , Patel Anil B. , Chattopadhyay Swaraj K. 
Published: May 2005

AbstractATP‐diphosphohydrolase, trypsin, and chymotrypsin have been insolubilized by lattice‐entrapment using hydrophilic polyacrylamide gel and hydrophobic Silastic matrices. The entrapped enzymes were stable and unaffected by washing or wet storage. Thermal inactivation properties of polyacrylamide‐entrapped ATP‐diphosphohydrolase were different from those of the same enzyme in solution. Several substrates were used for each of the proteolytic enzymes. Esterase activities of both trypsin and chymotrypsin were unaltered by entrapment within Silastic. The entrapment of enzymes and other active proteins is potentially of consequence in continuous‐flow substrate conversion systems. Silastic with a surface proteolytic activity derived from an entrapped enzyme is of possible medical utility for implantation elements.
Silastic entrapment of glucose oxidase–peroxidase and acetylcholine esterase
Authors: Pennington S. N. , Brown H. D. , Patel A. B. , Chattopadhyay S. K. 
Published: May 2005

AbstractAcetylcholine esterase and the glucose oxidase–peroxidase systems have been entrapped in Silastic matrices. The entrapped acetylcholine esterase exhibited remarkable stability as compared to the free enzyme in solution. The glucose oxidase–peroxidase system indicated that consecutive reactions may be carried out by several enzymes entrapped within a single matrix. The effect of various inorganic materials on the entrapped enzymes was also investigated.
In vitro testing of silicone rubber heart‐valve poppets for lipid absorption
Authors: Carmen Raleigh , Kahn Paul 
Published: May 2005

AbstractAn in vitro procedure for measuring the affinity of silicone rubber balls for lipid is described. The method appears to duplicate weight and volume increases occasionally noted in vivo. Potential lipid absorption is shown to increase with degree of cure, and decrease with filler content.
Attachment of prostheses to the musculo‐skeletal system by tissue ingrowth and mechanical interlocking
Authors: Hulbert S. F. , Cooke F. W. , Klawitter J. J. , Leonard R. B. , Sauer B. W. , Moyle D. D. , Skinner H. B. 
Published: May 2005

AbstractThe concept of tissue ingrowth into porous biomaterials as a means of attaching prostheses to the musculo‐skeletal system is reviewed. A compilation of the various ceramic materials studied in vivo to date along with the results of the studies is presented. Results of studies on kinetics of tissue ingrowth into porous biomaterials are summarized. A discussion of the parameters controlling the rate of tissue ingrowth into porous implants is presented.