bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of intermittent cyclic preloads on the response of articular cartilage explants to an excessive level of unconfined compression
Authors: Wei Feng , Golenberg Nurit , Kepich Eugene T. , Haut Roger C. 
Published: June 2008

AbstractMechanical loading of articular cartilage can influence chondrocyte metabolism and lead to alterations in cartilage matrix composition. Most previous studies have focused on the effect of cyclic loading on cartilage mechanical properties and proteoglycan synthesis. However, the role of proteoglycans synthesized from cyclically loaded cartilage in response to an acute overload has not been elucidated. Therefore, we conducted studies where low intensity, intermittent cyclic loading was applied to chondral explants prior to an acute unconfined compression on the tissue. The chondral explants were randomly assigned to three groups: 7, 14, and 21 days of 10 cycles of 0.2 Hz sinusoidal loading at 0.5 MPa followed by an unloaded interval of 3,600 s. All explants were then taken to 25 MPa of unconfined compression. Biochemical assays were conducted to determine the tissue proteoglycan and hydroxyproline contents. The results showed cyclic preloading increased the proteoglycan content and mechanically stiffened the explants, making them more resistant to matrix damage and cell death under 25 MPa of unconfined compression up to 14 days. After 21 days of cyclic loading, however, the explants lost compressive stiffness and suffered more extensive damage in the unconfined compression test. This study investigated the role of cyclic loading in response of chondral explants to a potentially damaging, acute overload. In the long term, these types of studies may help understand the role of preconditioning of articular cartilage for in vitro or even in vivo studies of blunt force trauma to a joint. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
New bone formation by murine osteoprogenitor cells cultured on corticocancellous allograft bone
Authors: Nelson Ehren R. , Huang Zhinong , Ma Ting , Lindsey Derek , Jacobs Christopher , Smith Robert L. , Goodman Stuart B. 
Published: June 2008

AbstractThe gold standard for bone grafting in orthopedics is autograft, however autograft has a limited supply and is associated with significant morbidity at the harvest site. One alternative, allograft bone, provides an osteoconductive scaffold, is in less limited supply, and it does not require a harvest from the patient. However, allograft lacks both osteogenic cells and osteoinductive proteins that make autograft bone so advantageous. This study provides a model to investigate strategies for augmentation of corticocancellous allograft bone discs with bone marrow‐derived osteoprogenitor cells (OPCs) plus exogenous growth factors in vitro. In this model, allograft bone discs were created by cutting 1‐mm thick slices from the distal femur and proximal tibia of euthanized mice. The allografts were sterilized and scanned by micro‐computed tomography (µCT) to provide the pre‐culture graft volume and trabecular characteristics. The discs were then seeded with OPCs harvested from murine bone marrow. The seeded grafts were placed in organ culture until harvest, after which they were re‐scanned by µCT and the data compared to the corresponding pre‐culture data. In addition, bone morphogenetic protein‐7 (BMP‐7, also know as osteogenic protein‐1 or OP‐1), basic fibroblast growth factor (bFGF), and OP‐1 combined with bFGF were added on a daily basis to the cultures. After final µCT scanning, all grafts were sectioned and evaluated histologically after hematoxylin and eosin (H&E) staining. µCT scans of cultured allografts with cells at 3, 5, and 9 weeks showed a time‐dependent, statistically significant increase in bone volume. The trabecular thickness (Tb.Th.) of grafts, from both groups that were augmented with OP‐1, showed a statistically significant increase in trabecular thickness of allografts with OPCs. These data suggest that bone marrow‐derived OPCs adhere to, and produce, new bone on corticocancellous allograft in vitro. When exogenous OP‐1 is added to this model, an increase in the production of bone onto the corticocancellous allograft bone disc is seen. This model allows for the investigation of the effects of multiple growth factors, and other interventions, on OPCs seeded onto allograft bone in vitro. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
The effect of hyaluronic acid on IL‐1β‐induced chondrocyte apoptosis in a rat model of osteoarthritis
Authors: Zhou Pang‐Hu , Liu Shi‐Qing , Peng Hao 
Published: June 2008

AbstractThe purpose of this article was to study the effect of hyaluronic acid (HA) on chondrocyte apoptosis in a rat osteoarthritis in vitro model (exposure to IL‐1β) and explore its mechanism. A rat in vitro model of osteoarthritis (OA) was established using 10 ng/mL IL‐1β as a modulating and chondrocyte apoptosis inducing agent. Different doses of HA (10, 20, and 40 µg/mL) were added 1 h prior to the addition of IL‐1β to a monolayer culture of freshly isolated juvenile rat chondrocytes. The ratio of apoptotic cell death was surveyed by Annexin V‐FITC and propidium iodide double‐labeling FACS analysis. The mitochondrial membrane potential of chondrocytes was evaluated by rhodamine‐123 fluorescence. The mitochondrial function was evaluated through detecting the ATP production by a luciferase assay. The reverse transcription polymerase chain reaction (RT‐PCR) was performed to measure mRNA expression levels of inducible oxide synthase (iNOS). HA could inhibit IL‐1β‐induced chondrocyte apoptosis in our cell culture model system. It was showed that addition of HA to the medium was able in a dose‐dependent way to reduce the impairment of the mitochondrial membrane potential and to restore mitochondrial ATP production. This study shows that HA could suppress in a dose‐dependent way chondrocyte apoptosis in our IL‐1β‐induced osteoarthritis model. The suppression of inflammatory cytokine activity within the joint might be one important mechanism of the clinical action of intraarticular injection of HA in the treatment of OA. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
The effect of oxidative aging on the wear performance of highly crosslinked polyethylene knee inserts under conditions of severe malalignment
Authors: Hermida Juan C. , Fischler Andrew , Colwell Clifford W. , D'Lima Darryl D. 
Published: June 2008

AbstractFirst‐generation crosslinked polyethylene developed for total hip arthroplasty has not gained wide acceptance for knee arthroplasty because of the increased potential for failure under high stresses and the increased risk for oxidative damage caused by free radicals. Sequentially crosslinked polyethylene (SQXL) is a second‐generation crosslinked polyethylene that is reported to reduce the level of free radicals and preserve mechanical properties. Three groups of ultrahigh molecular weight polyethylene inserts were wear tested after artificial aging as per ASTM F2003: gamma‐irradiated in air (GA‐aged), sequentially crosslinked (SQXL‐aged), and electron‐beam irradiated and remelted (EBeam‐aged). Inserts were tested in an AMTI knee wear simulator under malalignment conditions that were two standard deviations from the mean reported for computer‐navigated and conventionally aligned techniques. GA‐aged inserts delaminated by 500,000 cycles, and were severely damaged after 1 million cycles. None of the highly crosslinked inserts (SQXL‐aged or EBeam‐aged) delaminated or showed any signs of severe wear. Mean wear rate for GA‐aged inserts was 124.6 ± 49.4 mg/million cycles. Mean wear rates for SQXL‐aged and EBeam‐aged inserts were significantly lower (1.74 ± 0.3 and 4.72 ± 0.7, respectively). These results support the low levels of free radicals and preservation of mechanical properties reported in second‐generation crosslinked ultrahigh molecular weight polyethylene. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res, 2008
Effects of changing strategies of fracture fixation on immunologic changes and systemic complications after multiple trauma: Damage control orthopedic surgery
Authors: Pape Hans‐Christoph 
Published: June 2008

AbstractIn the treatment of polytrauma patients, multiple studies have shown how the timing and the type of the initial surgery of long bone fractures influence the incidence of systemic complications. Database analyses documented that unduly long surgical procedures undertaken early after trauma increase the risk of acute respiratory distress syndrom (ARDS), especially when femoral shaft fractures are stabilized. Animal research and prospective clinical studies also support the fact that the type of stabilization of a femoral shaft fracture may influence the systemic response to trauma. Reamed intramedullary reaming and nailing for a femoral shaft fracture is associated with an increased risk of pulmonary fat embolization from the medullary canal. This can result in pulmonary compromise if certain cofactors are also present. Modified reamers have been developed to reduce this side effect. The mediating effects are immunologic changes, varying according to the magnitude of the surgical procedure. Pro‐inflammatory markers (e.g., Interleukins) may be used to assess the inflammatory response to injury as well as the magnitude of surgery and the systemic impact induced by surgery. Serum levels of such markers can be used clinically to tailor the amount of surgery that is performed to the clinical condition of the patient. The potentially negative impact of excessive surgery in high‐risk patients can be avoided by using a new grading system for the assessment of the clinical status of the injured patient. Most recently, a large prospective randomized multicenter study has documented that this grading system is effective for identifying these borderline patients, and that in the borderline patient a staged surgical approach, such as temporary femoral stabilization with an external fixator, reduces the incidence of systemic complications. This work has changed the surgical management of multiply injured patients toward an approach that is tailored to the clinical condition of the patient, as indicated by well‐defined clinical parameters as well as objective measurements of serum cytokine levels. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1478–1484, 2008
The ruminal degradability of fibre explains part of the low nutritional value and reduced methanogenesis in highly tanniniferous tropical legumes
Authors: Tiemann Tassilo T , Lascano Carlos E , Kreuzer Michael , Hess Hans Dieter 
Published: June 2008

AbstractBACKGROUND: Limited forage quality and low methanogenesis from fermentation of tropical shrub legumes is often attributed to high contents of condensed tannins (CTs), but characteristics of the fibre may be important, too. Using the rumen‐simulation technique an attempt was made to separate the influence of tannins and fibre on ruminal digestion and methanogenesis. Legumes with CTs (Calliandra calothyrsus, Flemingia macrophylla) and plants free of CTs (Vigna unguiculata, Brachiaria humidicola) were used. To separate effects, either CTs were inactivated using polyethylene glycol or purified fibres free of CTs were obtained. In experiment 1, legumes replaced one third of grass in the diet and urea was supplemented. In experiment 2, only purified fibres and casein were incubated.RESULTS: Purified fibres had a different degradability (low in legumes with CTs). Lignin prevented mainly hemicellulose from being degraded while the extent of degradation of hemicellulose seemed to have determined methanogenesis. In the mixed diets these effects were small when the supply of N was sufficient. When CTs were inactivated, fibre degradation was still lower with Calliandra than with Vigna.CONCLUSION: Properties of fibre, especially lignification, of CT‐rich plants help to explain the low feeding value of such forages, but CTs represent the over‐riding factor. Copyright © 2008 Society of Chemical Industry
Relative importance of texture properties in the sensory quality and acceptance of commercial crispy products
Authors: Jaworska Danuta , Hoffmann Monika 
Published: June 2008

AbstractBACKGROUND: Understanding the textural properties of a food can be important for producers and marketers of crispy products. Relationships between texture, overall sensory quality (OSQ) and consumer acceptance of different products have been a field of interest for many authors. Despite this, results of research concerning the importance of texture remain inconclusive. The aim of this study was to evaluate the relationship between texture and other sensory attributes on an example of potato chips and their OSQ and consumer acceptance. To determine which attributes played a dominant role in the OSQ of chips, statistical correlations were calculated.RESULTS: Among the 11 attributes analysed, three had a positive relationship with the OSQ. These were: fried potato odour (r = 0.487), fried potato flavour (r = 0.597) and crispness (r = 0.570). The negative relation was observed for off‐flavour notes (r = − 0.740; − 0.693). Among the texture attributes, also negative, but without a dominant influence on OSQ, were hardness and undesirable type of fragmentation.CONCLUSION: Texture properties were found to be significantly correlated with OSQ as well as with consumer acceptance, but other attributes, especially those with negative sensory effects, determined OSQ of the products examined and are of crucial importance for consumer acceptance. Copyright © 2008 Society of Chemical Industry
Structure and Properties of PHA/Clay Nano‐Biocomposites Prepared by Melt Intercalation
Authors: Bordes Perrine , Pollet Eric , Bourbigot Serge , Avérous Luc 
Published: June 2008

AbstractPHA‐based nano‐biocomposites have been prepared by melt intercalation. Two main PHAs, poly(hydroxybutyrate) and poly(hydroxybutyrate‐co‐hydroxyvalerate) have been studied. Structural characterizations were conducted by advanced techniques like SAXS and TEM. A recent method has determined the degree of clay intercalation and dispersion using solid‐state NMR. Well intercalated small tactoids (3–10 layers) homogeneously dispersed into the polymer are obtained when good PHA–clay affinity exists, i.e., with organo‐modified MMT. In the case of non‐modified MMT, microcomposites are evidenced. Crystallization, mechanical, and thermal properties have been correlated to the materials structures.magnified image
Straightforward Determination of the Degree of N‐Acetylation of Chitosan by Means of First‐Derivative UV Spectrophotometry
Authors: da Silva Ricardo M. P. , Mano João F. , Reis Rui L. 
Published: June 2008

AbstractFirst‐derivative UV spectrophotometry is shown to be a reliable method for the determination of the degree of N‐acetylation of chitosan samples. A mathematical expression is derived that allows to determine the DA directly from the mass concentration of a chitosan solution and the first derivative of its UV spectrum at 202 nm, thus eliminating the need for empiric correction curves for highly deacetylated samples. A procedure is proposed for the accurate mass determination of the hygroscopic chitosan. The proposed approach facilitates the routine determination of the DA, especially when using potent multiwell microplate readers, which allow hundreds of samples to be measured in just a few minutes.magnified image
Effect of Glutaraldehyde Crosslinking Conditions on the Strength and Water Stability of Wheat Gluten Fibers
Authors: Reddy Narendra , Tan Yeanching , Li Ying , Yang Yiqi 
Published: June 2008

AbstractRegenerated protein fibers from plant proteins including wheat gluten lack the mechanical properties and water stability desired for usual applications. Crosslinking has been used to improve the properties of regenerated proteins fibers. Although glutaraldehyde is commonly used to crosslink proteins, the effect of various crosslinking conditions on the properties of the materials has not been studied. In this work, a systematic study of glutaraldehyde crosslinking conditions of wheat gluten fibers is presented and shows that even low concentrations of glutaraldehyde (0.05%) can improve the strength and water stability of wheat gluten fibers.magnified image
A Highly Selective, Colorimetric, and Fluorometric Multisignaling Chemosensor for Hg2+ Based on Poly(p‐phenyleneethynylene) Containing Benzo[2,1,3]thiadiazole
Authors: Liu Shu‐Juan , Fang Chun , Zhao Qiang , Fan Qu‐Li , Huang Wei 
Published: June 2008

AbstractA novel colorimetric and fluorometric chemosensor for Hg2+ detection based on poly(p‐phenyleneethynylene) (PPE) containing benzo[2,1,3]thiadiazole (BDT) has been developed. A highly Hg2+‐selective fluorescence quenching property in conjunction with a visible colorimetric change from yellow to violet can be observed, which indicates that PPE‐BDT can serve as a sensitive ‘naked‐eye’ indicator for Hg2+.magnified image
Porous Protein‐Based Nanoparticle Hydrogel for Protein Chips with Improved Sensitivity
Authors: Tanaka Hiroyuki , Isojima Tatsushi , Hanasaki Minako , Ifuku Yasuo , Takeuchi Hisao , Kawaguchi Haruma , Shiroya Toshifumi 
Published: June 2008

AbstractWe have discovered a novel method to prepare a protein‐based hydrogel, that is, a ‘three‐dimensional nanostructured protein hydrogel’ (3D NPH), which is composed of loosely inter‐connected protein–polymer hybrid nanoparticles. The 3D NPH can be easily prepared by spotting a protein/polymer mixture on a substrate. Surprisingly, gold nanoparticles carrying protein molecules easily diffuse into the 3D NPH through pores and spaces. We have shown that the protein chip made by our 3D NPH method has tremendously improved sensitivity in detecting protein–protein interactions compared with that by direct protein immobilization methods.magnified image
Towards Multipotent Coatings: Chemical Vapor Deposition and Biofunctionalization of Carbonyl‐Substituted Copolymers
Authors: Elkasabi Yaseen , Yoshida Mutsumi , Nandivada Himabindu , Chen Hsien‐Yeh , Lahann Joerg 
Published: June 2008

AbstractFuture advances in designing bioactive materials, such as antithrombotic coatings for cardiovascular stents, will require widely applicable and robust methods of surface modification. In this paper, we report on the development of multifunctional polymer coatings made by chemical vapor deposition (CVD) copolymerization. Polymer coatings of various [2.2]paracyclophane derivatives were co‐deposited in controlled ratios and their chemical composition verified by FT‐IR and X‐ray photoelectron spectroscopy. Furthermore, preliminary biocompatibility of these coatings was assessed using human umbilical vein endothelial cells and 3T3 murine fibroblasts. The parallel immobilization of two different antithrombotic biomolecules onto a CVD‐based copolymer is also demonstrated by orthogonal immobilization strategies.magnified image
Ultrasound‐Assisted Synthesis of Hybrid Vanadium Oxide/Polyaniline Nanowires
Authors: Malta Marcos , Silva Luiz Henrique , Galembeck André , Korn Mauro 
Published: June 2008

AbstractA single‐step sonochemical procedure to synthesize hybrid vanadium oxide/polyaniline nanowires starting from crystalline V2O5 and aniline in aqueous medium is presented. The synthesis explores the effect of high power ultrasounds on heterogeneous solid–aqueous phases, which leads to 30 nm width wires of 5 to 10 µm in length. Monomer intercalation and oxidative polymerization within the inorganic matrix proceed simultaneously with morphological changes. The electronic conductivity of hybrid nanowires reaches 0.8 S · cm−1 at room temperature.magnified image
Analysis of a particle method for the one‐dimensional Vlasov‐Maxwell system
Authors: Bostan Mihai 
Published: June 2008

AbstractIn this article we present a particle method for solving numerically the one‐dimensional Vlasov‐Maxwell equations. This method is based on the formulation by characteristics. We perform the error analysis and we investigate the properties of this scheme. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Time‐course and risk factors of hypothyroidism following allogeneic hematopoietic stem cell transplantation (HSCT) in children conditioned with fractionated total body irradiation
Authors: Bailey Heidi K. , Kappy Michael S. , Giller Roger H. , Gralla Jane 
Published: June 2008

AbstractBackgroundHypothyroidism is a complication of hematopoietic stem cell transplantation (HSCT)1 that has been studied primarily in children after matched sibling bone marrow transplantation. Unrelated donors and umbilical cord blood (CB) are now used in transplantation, and hypothyroidism in these populations is undocumented. Children who underwent fractionated total body irradiation (fTBI) and received bone marrow or umbilical cord blood transplantation from siblings or unrelated donors were examined for hypothyroidism over time.ProcedureAll children who received fTBI prior to allogeneic HSCT at The Children's Hospital (TCH), Denver between 1994 and 2002, and survived >1 year were included (N = 41 eligible; N = 33 met inclusion criteria). Probability of hypothyroidism was estimated by the Kaplan–Meier method and groups were compared using Cox's proportional hazards regression model.ResultsHypothyroidism developed in 52% of the children at a median time of 1.9 years (range 0.7–8.3 years). Primary compensated hypothyroidism was diagnosed in 94% of those affected. Children who received unrelated donor HSCT were 8.4 times more likely to develop hypothyroidism than those receiving matched sibling HSCT. Recipients of CB were 4.6 times more likely to have hypothyroidism than recipients of bone marrow.ConclusionsThere is a significant risk of developing hypothyroidism following fTBI, and allogeneic HSCT, that appears greater in recipients of unrelated donor HSCT and CB transplantation. Most of our patients who received BMT had sibling donors and the majority of CB transplants were from unrelated donors. It is difficult to determine which association is related to hypothyroidism, but the combination is significant. Pediatr Blood Cancer 2008;51:405–409. © 2008 Wiley‐Liss, Inc.
Spontaneous regression of an EBV‐associated monoclonal large B cell proliferation in the mastoid of a young child following surgical biopsy
Authors: McCabe Martin G. , Hook C. Elizabeth , Burke G.A. Amos 
Published: June 2008

AbstractWe report the spontaneous regression of an Epstein‐Barr virus‐associated monoclonal lymphoid proliferation in an immunocompetent child. A 2‐year‐old male with acute otitis media presented with a right‐sided facial palsy secondary to acute mastoiditis. During mastoid decompression a polypoid mass, a histologically diffuse large B cell lymphoma, was found. Staging revealed localized disease. At surgical re‐exploration 5 weeks later the disease had resolved. Retrospective serological testing was consistent with an acute Epstein‐Barr viral infection and in situ hybridization of the tumour tissue was positive for Epstein‐Barr RNA. Pediatr Blood Cancer 2008;51:557–559. © 2008 Wiley‐Liss, Inc.