bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory tests of steel simple torsionally unbalanced models
Authors: De‐la‐Colina Jaime , Acuña Qutberto , Hernández Alejandro , Valdés Jesús 
Published: November 2006

AbstractThe objective of this work is to obtain estimations of the amplification factors α and δ used for torsion design of buildings, from experiments. For this study, simple one‐storey torsionally unbalanced (TU) steel models were considered. Models consisted of a deck supported on four columns with a selected arrangement of hinges at column ends. Two theoretical structural eccentricities (e = 0.05 and 0.15) were considered. Models were excited with a simple long‐period pendulum consisting of a hanging platform with a forced‐vibration generator on it. Eight models were tested at several excitation levels (frequencies and force magnitudes) in both ranges of behaviour: elastic and inelastic. Experiments were conducted at three frequency ratios of excitation. Registered accelerations of the pendulum platform indicate that the experimental set‐up leads to excitations that resemble narrow‐band seismic ground motions. Frame shear force estimations, based on accelerations recorded at both deck sides, indicate that torsion design factors (α and δ) depend on eccentricity. Estimations of frame shears based on measurements indicate that for normalized eccentricities e ⩾ 0.025, the amplification α can be between 2 and 3; while δ factor resulted between 0.0 and 1.6. Copyright © 2006 John Wiley & Sons, Ltd.
Controlling the thermal environment in hot spots of buried power cables
Authors: Klimenta D. , Nikolajević S. , Sredojević M. 
Published: November 2006

AbstractAn approach to numerical modelling of temperature distributions around buried power cables using finite element analysis is presented in this paper. The finite element algorithms are based on time‐dependent heat sources of the environment and temperature‐dependent material properties of the cables. The nonlinear steady‐state and transient heat transfer algorithms are applied to the problem of controlling thermal environment in an actual hot spot of a 110 kV cable line installed in Belgrade, Republic of Serbia. Moreover, this paper outlines the influence of an underground heating pipeline on ampacities of the cable line, and two retrofitting procedures for optimising the thermal properties of cable environment. Two suggested procedures for thermal optimisation of the actual hot spot are: the use of a new‐mixed corrective backfill and the use of quartz sand. Finally, actual test cases using the measured data indicate the possibilities of using the proposed algorithms. Copyright © 2006 John Wiley & Sons, Ltd.
On the orbital motion of a rotating inner cylinder in annular flow
Authors: Feng Shunxin , Li Qibing , Fu Song 
Published: November 2006

AbstractIn this paper, numerical calculations have been performed to analyse the influence of the orbital motion of an inner cylinder on annular flow and the forces exerted by the fluid on the inner cylinder when it is rotating eccentrically. The flow considered is fully developed laminar flow driven by axial pressure gradient. It is shown that the drag of the annular flow decreases initially and then increases with the enhancement of orbital motion, when it has the same direction as the inner cylinder rotation. If the eccentricity and rotation speed of the inner cylinder keep unchanged (with respect to the absolute frame of reference), and the orbital motion is strong enough that the azimuthal component (with respect to the orbit of the orbital motion) of the flow‐induced force on the inner cylinder goes to zero, the flow drag nearly reaches its minimum value. When only an external torque is imposed to drive the eccentric rotation of the inner cylinder, orbital motion may occur and, in general, has the same direction as the inner cylinder rotation. Under this condition, whether the inner cylinder can have a steady motion state with force equilibrium, and even what type of motion state it can have, is related to the linear density of the inner cylinder. Copyright © 2006 John Wiley & Sons, Ltd.
Use of single saphenous interposition vein graft for primary arterial circuit and secondary recipient site in head and neck reconstruction: A case report
Authors: Chang Kao‐Ping , Lee Hsiao‐Chen , Lai Chung‐Sheng , Lin Sin‐Daw 
Published: November 2006

AbstractBackground.Autologous vein grafts are a valuable tool in microsurgical free tissue transfer. Interposition vein grafts offer the surgeon greater freedom when placing the free flap and choosing the recipient vessels, providing valuable options in case recipient vessels are not available for those patients with large wounds. Free flaps transferred to head and neck regions carry a higher risk of failure, which may be expected to increase more with the use of vein grafts.Methods.We present our case with the double use of a single vein graft for both primary arterial conduit in end‐to‐end fashion and secondary end‐to‐side recipient site in the microsurgical reconstruction of a complicated head and neck defect.Results.All these anastomoses and flaps survived perfectly, and the patient was discharged 14 days after the transfer of the second flap.Conclusion.Although the anastomosis of 2 flaps to a single vein graft was successful in our case, it represents a higher risk option than different recipient vessels. We provide this alternative procedure in selected patients, as there is no other receipt vessel or recipient blood flow strong enough to supply more than 1 flap. © 2006 Wiley Periodicals, Inc. Head Neck, 2007
Intraoral proliferative myositis: Case report and literature review
Authors: Brooks John K. , Scheper Mark A. , Kramer Richard E. , Papadimitriou John C. , Sauk John J. , Nikitakis Nikolaos G. 
Published: November 2006

AbstractBackground.Proliferative myositis is a rare, benign, reactive intramuscular lesion of fibroblastic/myofibroblastic origin; an identical lesion in a subcutaneous or fascial location is referred to as proliferative fasciitis. The rapid growth rate and unusual histopathologic features have frequently been mistaken for a malignant process and have promoted unnecessary invasive procedures. Here we present only the third oral case of proliferative myositis, arising from the tongue of a 65‐year‐old man.Methods and Results.Histologically, the resected lesion was composed of numerous fibroblastic or myofibroblastic spindle cells and variable numbers of large ganglion‐like cells infiltrating between and around muscle fascicles, resembling a “checkerboard” configuration. A demographic profile of proliferative myositis of the head and neck is also provided, compiled from 19 patients culled from an English‐language literature review and this report.Conclusions.Incisional biopsy or fine‐needle aspiration biopsy of proliferative myositis of the head and neck should lead to spontaneous resolution and is, therefore, sufficient to render the diagnosis and to provide conservative treatment. Recurrence is extremely rare. © 2006 Wiley Periodicals, Inc. Head Neck, 2007
In vivo response to starch‐based scaffolds designed for bone tissue engineering applications
Authors: Salgado A.J. , Coutinho O.P. , Reis R.L. , Davies J.E. 
Published: November 2006

AbstractOur purpose was to evaluate the in vivo endosseous response to three starch‐based scaffolds implanted in rats (n = 54). We implanted the three scaffold groups; a 50/50 (wt %) blend of corn starch and ethylene‐vinyl alcohol (SEVA‐C), the same composition coated with a biomimetic calcium phosphate (Ca‐P) layer (SEVA‐C/CaP), and a 50/50 (wt %) blend of corn starch and cellulose acetate (SCA), all produced by extrusion with blowing agents, into distal femurs proximal to the epiphyseal plate, for 1, 3, or 6 weeks. Our results showed that at 1 week considerable reparative bone formed around all scaffold groups, although the bone was separated from the scaffold by an intervening soft tissue interfacial zone that comprised two distinct compartments: the surface of the scaffold was occupied by multinucleate giant cells and the compartment between these cells and the surrounding bone was occupied by a streaming fibrous‐like tissue. The extracellular matrix of the latter was continuous with the extracellular bone matrix itself, labeled positively for osteocalcin and appeared mineralized by back‐scattered electron imaging. All three scaffolds showed a similar tissue response, with the soft tissue interface diminishing with time. No bone contact was observed with SEVA‐C at any time point, only transitory bone contact was observed with SEVA‐C/CaP at 3 weeks, but SCA exhibited direct bone contact at 6 weeks where 56.23 ± 6.46% of the scaffold surface was occupied by bone. We conclude that all materials exhibited a favorable bony response and that the rapidly forming initial “connective tissue” seen around all scaffolds was a very early form of bone formation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Preclinical biocompatibility assessment of the EVAHEART ventricular assist device: Coating comparison and platelet activation
Authors: Snyder Trevor A. , Tsukui Hiroyuki , Kihara Shin'Ichiro , Akimoto Takehide , Litwak Kenneth N. , Kameneva Marina V. , Yamazaki Kenji , Wagner William R. 
Published: November 2006

AbstractThromboembolism and bleeding remain significant complications of ventricular assist device (VAD) support. Increasing the amount of biocompatibility data collected during preclinical studies can provide additional criteria to evaluate device refinements, while design changes may be implemented before entering clinical use. Twenty bovines were implanted with the EVAHEART centrifugal VAD for durations from 30 to 196 days. Titanium alloy pumps were coated with either diamond‐like carbon or 2‐methoxyethyloylphosphoryl choline (MPC). Activated platelets and platelet microaggregates were quantified by flow cytometry, including two new assays to quantify bovine platelets expressing CD62P and CD63. Temporally, all assays were low preoperatively, then significantly increased following VAD implantation, before declining to a lower, but still elevated level over 2–3 weeks. MPC‐coated VADs produced significantly fewer activated platelets after implant trauma effects diminished. Three animals receiving no postoperative anticoagulation had similar amounts of circulating activated platelets and platelet microaggregates as animals receiving warfarin anticoagulation. Two new methods to quantify bovine activated platelets using antibodies to CD62P and CD63 were characterized and applied. These measures, along with previously described assays, were able to differentiate between two biocompatible coatings and assess effects of anticoagulation regimen in VAD preclinical testing. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Comparison of the clinical and preclinical biocompatibility testing of dental materials: Are the ISO usage tests meaningful?
Authors: Murray Peter E. , Garcia‐Godoy Franklin 
Published: November 2006

AbstractInternational Organization for Standardization (ISO 10993 and 7405) guidelines recommends the preclinical screening of dental materials using non‐human primates. The literature contains no comparisons of responses to dental materials. To test the accuracy of preclinical screening tests for predicting human clinical responses, 106 class V pulp exposed cavities were prepared in human and non‐human primate teeth. Teeth were restored with calcium hydroxide and amalgam, zinc oxide eugenol or resin‐modified glass ionomer. Teeth were extracted after 10–163 days and prepared for histological analysis. Pulp cell numbers were compared and their reactionary dentin activity measured in response to cavity preparation. Pulp inflammatory activity was categorized according to ISO standards. There were no statistically significant differences between human and non‐human primate teeth in terms of pulp reactions to dental materials. The use of non‐human primates for preclinical biocompatibility investigation provided an accurate method of evaluating clinical responses to dental materials. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Surface functional group dependent apatite formation on bacterial cellulose microfibrils network in a simulated body fluid
Authors: Nge Thi Thi , Sugiyama Junji 
Published: November 2006

AbstractThe apatite forming ability of biopolymer bacterial cellulose (BC) has been investigated by soaking different BC specimens in a simulated body fluid (1.5 SBF) under physiological conditions, at 37°C and pH 7.4, mimicking the natural process of apatite formation. From ATR‐FTIR spectra and ICP‐AES analysis, the crystalline phase nucleated on the BC microfibrils surface was calcium deficient carbonated apatite through initial formation of octacalcium phosphate (OCP) or OCP like calcium phosphate phase regardless of the substrates. Morphology of the deposits from SEM, FE‐SEM, and TEM observations revealed the fine structure of thin film plates uniting together to form apatite globules of various size (from <1 μm to 3 μm) with respect to the substrates. Surface modification by TEMPO (2,2,6,6‐tetramethylpyperidine‐1‐oxyl)‐mediated oxidation, which can readily form active carboxyl functional groups upon selective oxidation of primary hydroxyl groups on the surface of BC microfibrils, enhanced the rate of apatite nucleation. Ion exchanged treatment with calcium chloride solution after TEMPO‐mediated oxidation was found to be remarkably different from other BC substrates with the highest deposit weight and the smallest apatite globules size. The role of BC substrates to induce mineralization rate differs according to the nature of the BC substrates, which strongly influences the growth behavior of the apatite crystals. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Tissue factor and thrombomodulin expression on endothelial cell‐seeded collagen modules for tissue engineering
Authors: She Mingyu , McGuigan Alison P. , Sefton Michael V. 
Published: November 2006

AbstractThe creation of functional tissue engineering constructs to repair or replace diseased tissues requires a well‐formed vasculature network within the construct and the endothelial cells lining that vascular bed must display a nonthrombogenic phenotype. A new approach to tissue engineering involves the assembly of smaller components (modules fabricated at the hundred micron scale) into larger constructs. The modules, collagen gel containing the particular tissue cell of interest, are covered with endothelial cells prior to assembly so that the interconnected channels that are formed are lined with endothelial cells, creating a mimic of a vascular network. Here, we confirmed (using confocal microscopy primarily) that the human umbilical vein endothelial cells, seeded on collagen gel modules without a second embedded cell and without flow, bore the molecular markers of low thrombogenicity. Two days, after seeding on the modules, endothelial cells displayed the typical cobblestone morphology, formed tight cell–cell junctions and covered the whole module surface. Immunofluorescence staining showed that at both 2 days and 7 days after seeding, only a few cells expressed tissue factor while this number was dramatically increased after TNFα stimulation. On the other hand, thrombomodulin was expressed by the majority of seeded cells and expression was reduced after TNFα stimulation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
The role of biological extracellular matrix scaffolds in vascularized three‐dimensional tissue growth in vivo
Authors: Cronin Kevin J. , Messina Aurora , Thompson Erik W. , Morrison Wayne A. , Stevens Geoffrey W. , Knight Kenneth R. 
Published: November 2006

AbstractAn in vivo murine vascularized chamber model has been shown to generate spontaneous angiogenesis and new tissue formation. This experiment aimed to assess the effects of common biological scaffolds on tissue growth in this model. Either laminin‐1, type I collagen, fibrin glue, hyaluronan, or sea sponge was inserted into silicone chambers containing the epigastric artery and vein, one end was sealed with adipose tissue and the other with bone wax, then incubated subcutaneously. After 2, 4, or 6 weeks, tissue from chambers containing collagen I, fibrin glue, hyaluronan, or no added scaffold (control) had small amounts of vascularized connective tissue. Chambers containing sea sponge had moderate connective tissue growth together with a mild “foreign body” inflammatory response. Chambers containing laminin‐1, at a concentration 10‐fold lower than its concentration in Matrigel™, resulted in a moderate adipogenic response. In summary, (1) biological hydrogels are resorbed and gradually replaced by vascularized connective tissue; (2) sponge‐like matrices with large pores support connective tissue growth within the pores and become encapsulated with granulation tissue; (3) laminin‐containing scaffolds facilitate adipogenesis. It is concluded that the nature and chemical composition of the scaffold exerts a significant influence on the amount and type of tissue generated in this in vivo chamber model. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Histological and histomorphometrical comparative study of the degradation and osteoconductive characteristics of α‐ and β‐tricalcium phosphate in block grafts
Authors: Yamada Masahiro , Shiota Makoto , Yamashita Yasuo , Kasugai Shohei 
Published: November 2006

AbstractThe purpose of the present study was to compare α‐ and β‐tricalcium phosphate (TCP) as bone graft material for augmenting highly resorbed alveolar ridges. The cranial bones of 15 rabbits were used. Three titanium chambers filled with porous blocks of α‐TCP, β‐TCP, or blood clots were placed in each slit. The two TCP blocks had similar inner/outer structures and purities. Animals were sacrificed after 2, 4, and 8 weeks. Specimens were embedded in polyester resin as nondecalcified specimens, and evaluated both histologically and histomorphometrically. In both TCP groups, blocks had hardly degraded at 2 weeks while in the α‐TCP group, the block had notably started degrading after 4 weeks. In the β‐TCP group, degradation began at 4 weeks and this degradation had increased just slightly after 8 weeks. The α‐TCP block degraded significantly more than the β‐TCP block. Residual α‐TCP particles surrounded by newly formed bone decreased over time, and both particles and newly formed bone were simultaneously absorbed by osteoclast‐like cells. These observations suggest that residual α‐TCP particles surrounded by newly formed bone may disappear progressively from bone and could be incorporated into the bone remodeling cycle in combination with newly formed bone. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Internal adaptation and some physical properties of methacrylate‐based denture base resins polymerized by different techniques
Authors: Ganzarolli Solimar M. , Nunes de Mello José A. , Shinkai Rosemary S. , Del Bel Cury Altair A. 
Published: November 2006

AbstractThis study evaluated the internal adaptation, porosity, transverse and impact strength of three denture base polymers: (1) conventional heat‐polymerized, (2) microwave‐polymerized, and (3) injection‐molded resins. Internal adaptation was measured by weighing a vinyl polysiloxane film reproducing the gap between the denture base and the metallic master model of an edentulous maxilla. The measurements were performed immediately after finishing and after 30‐day storage in water. Porosity was evaluated by weighing each specimen in air and in water using an analytical scale balance. Transverse strength test (three‐point bending test) was performed using a universal machine under axial load, at a crosshead speed of 5 mm/min. Impact strength test (Charpy's test) was performed with a 40 kJ/cm load. Data were analyzed by ANOVA and Tukey test (α = 0.05). Internal adaptation, porosity, transverse and impact strength varied according to the type of acrylic resin and the processing technique. The injection‐molded resin showed better internal adaptation compared with the conventional heat‐polymerized and the microwave‐polymerized resins, particularly after 30 days, but there was no relevant improvement of porosity, transverse and impact strength. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Biocompatibility of electrophoretical deposition of nanostructured hydroxyapatite coating on roughen titanium surface: In vitro evaluation using mesenchymal stem cells
Authors: Chen F. , Lam W. M. , Lin C. J. , Qiu G. X. , Wu Z. H. , Luk K. D. K. , Lu W. W. 
Published: November 2006

AbstractA nano hydroxyapatite (HAp) layer was coated on a roughen titanium surface by means of electrophoretic deposition with an acetic anhydride solvent system. The objectives of this current study are to investigate whether nano‐HAp can improve mechanical strength at a lower sintering temperature and biocompatibility. Densification temperature was lowered from usual 1000 to 800°C. The coating interfacial bonding strength, phase purity, microstructure, and biocompatibility were investigated. Degradation of HA phase was not detected in XRD. A porous TiO2 layer acts as a gradient coating layer with an intermediate thermal expansion coefficient between hydroxyapatite and titanium that reduces the thermal stress. From SEM image, the coating does not contain any crack. Mesenchymal stem cell (MSC) is the progenitor cell for various tissues in mature animals, which can improve integration of bone tissue into implant. In this in vitro study, rabbit MSCs culture indicated that the HAp/Ti nanocomposite biomaterial had good biocompatibility and bioactivity. Around materials and on its surface cell grew well with good morphology. Proliferation of the MSCs on the nano‐HAp coating was higher than its micron counterpart in XTT assay. These properties show potential for the orthopaedic and dental applications. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Material model measurements and predictions for a random pore poly(ϵ‐caprolactone) scaffold
Authors: Quinn T. P. , Oreskovic T. L. , Landis F. A. , Washburn N. R. 
Published: November 2006

AbstractWe investigated material models for a polymeric scaffold used for bone. The material was made by co‐extruding poly(ε‐caprolactone) (PCL), a biodegradable polyester, and poly(ethylene oxide) (PEO). The water soluble PEO was removed resulting in a porous scaffold. The stress–strain curve in compression was fit with a phenomenological model in hyperbolic form. This material model will be useful for designers for quasi‐static analysis as it provides a simple form that can easily be used in finite element models. The ASTM D‐1621 standard recommends using a secant modulus based on 10% strain. The resulting modulus has a smaller scatter in its value compared with the coefficients of the hyperbolic model, and it is therefore easier to compare differences in material processing and ensure quality of the scaffold. A prediction of the small–strain elastic modulus was constructed from images of the microstructure. Each pixel of the micrographs was represented with a brick finite element and assigned the Young's modulus of bulk PCL or a value of 0 for a pore. A compressive strain was imposed on the model and the resulting stresses were calculated. The elastic constants of the scaffold were then computed with Hooke's law for a linear‐elastic isotropic material. The model was able to predict the small–strain elastic modulus measured in the experiments to within one standard deviation. Thus, by knowing the microstructure of the scaffold, its bulk properties can be predicted from the material properties of the constituents. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006