bluuebunny/crossref_metadata_2025 huggingface dataset:
Frontal bone defect repair with experimental glass‐fiber‐reinforced composite with bioactive glass granule coating
Authors: Tuusa S. M.‐R. , Peltola M. J. , Tirri T. , Lassila L. V. J. , Vallittu P. K.
Published: November 2006

Objective: The aim of this preliminary study was to test the bioactive glass‐coated fiber‐reinforced composite (FRC) as a reconstruction material in the treatment of experimental defects in the frontal bone of rabbits. Methods: FRC made of E‐glass fiber and BisGMA‐PMMA resin matrix system was used in the study. Pieces of nonpolymerized FRC were coated with particulate bioactive glass granules S53P4 (BAG), and then the FRC was polymerized and post‐cured by heat in air to reduce the quantity of residual monomers, and to sterilize the material for the animal study. Two round defects (5 mm in diameter) were drilled in the upper bony walls of 12 NZW rabbits' frontal sinuses, and rectangular FRC plates were applied over the defects. In the control group, no FRC plates were used. The bone defect healing process was evaluated on histological sections at 3, 6, and 8 weeks, postoperatively. SEM‐EDX analysis was used to determine reactive layers of bioactive glass granules. Results: The healing progressed from the fibroconnective tissue phase at 3 weeks to lamellar bone formation at 6 and 8 weeks. The difference in new bone formation between the implantation groups and control groups was not statistically significant, although in some animals the effect of the implant on bone healing was clearly positive. A moderate foreign body reaction was seen on the implant surface where BAG granules did not uniformly cover the implant's polymer matrix. Conclusions: This study suggests that the tested FRC implant with bioactive glass coating provides an alternative for bone defect reconstruction. However, more research on this composite material and its biocompatibility is needed. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
A‐part gel—An efficient adhesion prevention barrier
Authors: Weis Christine , Odermatt Erich K.
Published: November 2006

Two different poly(vinyl alcohol)‐based gels (A‐Part Gel) were compared and evaluated as possible adhesion prophylaxis gels. The gels were implanted to act as a physical barrier—and thus to prevent adhesions—in a rabbit sidewall model. The absorption time of any adhesion barrier is a critical parameter, since the wounded tissue needs to be covered during the healing process. Crosslinking by freeze‐thawing helped to prolong the absorption time of the gels. To better understand the in vivo absorption, the gels were investigated in various physical in vitro methods such as decay measurements and experiments performed in a Soxhlet extraction thimble. The in vivo applicability of the gels by surgeons was judged in squeezing force measurements. The ability to cover the wounded area securely was measured with simple spreading experiments. Both gels could be squeezed out of the syringes easily and showed a homogenous spreading behavior. Comparing the two gels, the results of the in vitro absorption experiments were contradictive. Further, in vivo tests with correlations to the proposed in vitro measurements will reveal the correct interpretation. Nevertheless, the results in a pilot rabbit sidewall model were excellent for both A‐Part gels, but only one gel was chosen for extended studies, showing only 20% adhesions when compared with the control group showing 100% strong adhesion formations. These data will be evaluated in other studies, and the use of an A‐Part PVA‐CMC gel for adhesion prevention has to be supported in clinical studies. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Hydrogel‐filled polylactide porous scaffolds for cartilage tissue engineering
Authors: Gong Yihong , He Lijuan , Li Jun , Zhou Qingliang , Ma Zuwei , Gao Changyou , Shen Jiacong
Published: November 2006

Polymer porous scaffolds and hydrogels have been separately employed as analogues of the native extra‐cellular matrix (ECM). However, both of these two kinds of materials have their own advantages and shortcomings. In this work, an attempt to combine the advantages of these two kinds of materials is carried out. Poly‐L‐lactide (PLLA) scaffolds with good mechanical properties were prepared by thermally induced phase separation, which were then filled with hydrogel aiming at entrapment of cells within a support of predefined shape. Agar, which has a function to promote chondrogenesis, was selected to entrap chondrocytes, acting as analogues of native ECM. A straight forward merit of this construct is that both mechanical strength and macroscopic shape, and analogous ECM can be simultaneously achieved. The morphology and distribution of the chondrocytes were studied by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The cell growth behaviors were determined by MTT assay and collagen and glycosaminoglycan (GAG) secretion. After culture for 7 and 14 days, the cells in the construct were round and surrounded by the hydrogel. The MTT viability and the cell secretion in the chondrocytes/agar/scaffold construct were also higher than that of the chondrocytes/scaffold construct (control). Gelatin was further introduced into the construct, yielding improved GAG secretion and cytoviability. After implantation in the subcutaneous dorsum of nude mice for 4 weeks, cartilage‐like specimens maintaining their original rectangular shapes were harvested. Histological examination showed that new cartilage was regenerated and a large quantity of collagen and GAG were secreted, while the cells in the control PLLA scaffold turned to be fibroblast‐like with less secretion of extracellular matrices. The method provides a useful pathway of scaffold preparation and cell transplantation, which can achieve suitable mechanical properties and good cell performance simultaneously. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Journey in reverse: TTP from bedside to blood bank to bench
Authors: Moake Joel L.
Published: November 2006

Thrombotic thrombocytopenic purpura (TTP) is the most extensive and dangerous intravascular platelet clumping disorder. For more than a half‐century after its initial recognition, mortality was near 100% and the etiology totally obscure. Then, in the late 1970s to early 1980s, empiric, but successful, therapy by a few clinician/blood bank partnerships was followed by sudden laboratory insight into pathophysiology. The discussion that follows was prepared in conjunction with the 2006 Francis Morrison, M.D., Memorial Lecture at the 27th Annual Meeting of the American Society for Apheresis. J. Clin. Apheresis. © 2006 Wiley‐Liss, Inc.
What is the function of centrioles?
Authors: Marshall Wallace F.
Published: November 2006

The function of centrioles has been controversial and remains incompletely resolved. This is because centrioles, in and of themselves, do not directly perform any physiological activity. Instead, their role is only to act as a jig or breadboard onto which other functional structures can be built. Centrioles are primarily involved in forming two structures—centrosomes and cilia. Centrioles bias the position of spindle pole formation, but because spindle poles can self‐organize, the function of the centriole in mitosis is not obligatory. Consequently, lack of centrioles does not generally prevent mitosis, although recent experiments suggest acentriolar spindles have reduced fidelity of chromosome segregation. In contrast, centrioles are absolutely required for the assembly of cilia, including primary cilia that act as cellular antennae. Consistent with this requirement, it is now becoming clear that many ciliary diseases, including nephronophthisis, Bardet‐Biedl syndrome, Meckel Syndrome, and Oral‐Facial‐Digital syndrome, are caused by defects in centriole‐associated proteins. J. Cell. Biochem. 100: 916–922, 2007. © 2006 Wiley‐Liss, Inc.
Palladin regulates cell and extracellular matrix interaction through maintaining normal actin cytoskeleton architecture and stabilizing Beta1‐integrin
Authors: Liu Xue‐Song , Luo Hui‐Jun , Yang Hua , Wang Long , Kong Hui , Jin Yue‐E , Wang Fang , Gu Ming‐Min , Chen Zhu , Lu Zhen‐Yu , Wang Zhu‐Gang
Published: November 2006

Cell and extracellular matrix (ECM) interaction plays an important role in development and normal cellular function. Cell adhesion and cell spreading on ECM are two basic cellular behaviors related to cell‐ECM interaction. Here we show that palladin, a novel actin cytoskeleton‐associated protein, is actively involved in the regulation of cell‐ECM interaction. It was found that palladin‐deficient mouse embryonic fibroblasts (MEFs) display decreased cell adhesion and compromised cell spreading on various ECMs. Disorganized actin cytoskeleton architecture characterized by faint stress fibers, less lamellipodia and focal adhesions can account for the weakened cell‐ECM interaction in palladin−/− MEFs. Furthermore, decreased polymerized filament actin and increased globular actin can be observed in palladin−/− MEFs, strongly suggesting that palladin is essential for the formation or stabilization of polymerized filament actin. Elevated phospho‐cofilin level and proper responses in cofilin phosphorylation to either Rho signal agonist or antagonist in palladin−/− MEFs indicate that disrupted stress fibers in palladin−/− MEFs is not associated with cofilin phosphorylation. More interestingly, the protein level of ECM receptor β1‐integrin is dramatically decreased in MEFs lacking palladin. Down‐regulation of β1‐integrin protein can be restored by proteasome inhibitor MG‐132 treatment. All these data implicate that palladin is essential for cell‐ECM interaction through maintaining normal actin cytoskeleton architecture and stabilizing β1‐integrin protein. J. Cell. Biochem. 100: 1288–1300, 2007. © 2006 Wiley‐Liss, Inc.
The origin of the two‐electron/four‐centers CC bond in π‐TCNE22− dimers: Electrostatic or dispersion?
Authors: García‐Yoldi Iñigo , Mota Fernando , Novoa Juan J.
Published: November 2006

The structure and stability of the π‐TCNE22− dimers in K2TCNE2 aggregates is revisited trying to find if the origin of their two‐electron/four‐centers CC bond are the electrostatic K+‐TCNE− interactions or the dispersion interactions between the anions. The study is done at the HF, B3LYP, CASSCF (2,2), and MCQDPT/CASSCF (2,2) levels using the 6‐31+G(d) basis set. Our results show that the only minima of this aggregate that preserves the π‐TCNE22− structure has the two K+ atoms placed in equatorial positions in between the two TCNE− planes. When the K+ atoms are placed along the D2h axis of the anions the structure is not a minimum. The main energetic component responsible for the stability of these aggregates comes from the cation–anion interactions. However, a proper accounting of the dispersion component (as done in the MCQDPT/CASSCF (2,2) calculations) is needed to make the closed‐shell singlet more stable than the open‐shell singlet. Thus, the bond results from the combination of the electrostatic and dispersion components, being the first the dominant one. The optimum geometry of the closed‐shell singlet is very similar to the experimental one found in crystals. © 2006 Wiley Periodicals, Inc. J Comput Chem 2007
Atom–atom partitioning of total (super)molecular energy: The hidden terms of classical force fields
Authors: Rafat M. , Popelier P. L. A.
Published: November 2006

Classical force fields describe the interaction between atoms that are bonded or nonbonded via simple potential energy expressions. Their parameters are often determined by fitting toab initioenergies and electrostatic potentials. A direct quantum chemical guide to constructing a force field would be the atom–atom partitioning of the energy of molecules and van der Waals complexes relevant to the force field. The authors used the theory of quantum chemical topology to partition the energy of five systems [H2, CO, H2O, (H2O)2, and (HF)2] in terms of kinetic, Coulomb, and exchange intra‐atomic and interatomic contributions. The authors monitored the variation of these contributions with changing bond length or angle. Current force fields focus only on interatomic interaction energies and assume that these purely potential energy terms are the only ones that govern structure and dynamics in atomistic simulations. Here the authors highlight the importance of self‐energy terms (kinetic and intra‐atomic Coulomb and exchange). © 2006 Wiley Periodicals, Inc. J Comput Chem 2007
Gilbert N. Lewis and the chemical bond: The electron pair and the octet rule from 1916 to the present day
Authors: Gillespie R. J. , Robinson E. A.
Published: November 2006

We describe the development of Lewis's ideas concerning the chemical bond and in particular the concept of the electron pair bond and the octet rule. We show that the concept of the electron pair bond has endured to the present day and is now understood to be a consequence of the Pauli principle. In contrast the octet rule is now regarded as much less important than was originally generally believed, although Lewis himself knew several exceptions and regarded it as less important than what he called the rule of two (the electron pair). The octet rule was more strongly promoted by Langmuir who is also responsible for the term covalent bond. However, many more exceptions to the octet rules than were known to Lewis are now known and the terms hypervalent and hypovalent used to describe such molecules are no longer particularly useful. Today it is realized that bonding electron pairs in many molecules are not as well localized as Lewis believed, nevertheless resonance structures, i.e., plausible alternative Lewis structures, are still often used to describe such molecules. Moreover electrons are not always found in pairs, as for example in linear molecules, which can, however, be satisfactorily described by Linnett's double quartet theory. The electron density distribution in a molecule can now be analyzed using the ELF and other functions of the electron density to show where electron pairs are most probably to be found in a molecule. © 2006 Wiley Periodicals, Inc. J Comput Chem 2007
Lipid raft‐dependent endocytosis of metallothionein in HepG2 cells
Authors: Hao Qiang , Hong Sung‐Hye , Maret Wolfgang
Published: November 2006

Human hepatocellular carcinoma (HepG2) cells take up metallothionein (MT) by endocytosis. MT co‐localizes with albumin but not with transferrin, indicating uptake via a non‐classical pathway rather than via clathrin‐mediated endocytosis. A lipid raft‐dependent uptake is indicated by pravastatin inhibition of cholesterol synthesis and methyl‐β‐cyclodextrin inhibition of cholesterol translocation to the plasma membrane, reducing MT uptake by 29% and 69%, respectively. Subcellular fractionation after MT uptake reveals significant amounts of MT in vesicular fractions including lysosomes but virtually no MT in the cytosol. Metals bound to MT are released into the cytosol, however. The findings define a pathway for cellular metal acquisition. Together with results from other studies demonstrating secretion of MT from different cells and the presence of MT in extracellular fluids, the results suggest a function of MT in intercellular communication. J. Cell. Physiol. 210: 428–435, 2007. © 2006 Wiley‐Liss, Inc.
The search for non‐chordate retinoic acid signaling: lessons from chordates
Authors: Simões‐costa Marcos S. , Azambuja Ana Paula , Xavier‐Neto José
Published: November 2006

Signaling by retinoic acid (RA) is an important pathway in the development and homeostasis of vertebrate and invertebrate chordates, with a critical role in mesoderm patterning. Classical studies on the distribution of nuclear receptors of animals suggested that the family of RA receptors (RARs/NR1B) was restricted to chordates, while the family of RA X receptors (RXR/NR2B) was distributed from cnidarians to chordates. However, the accumulation of data from genome projects and studies in non‐model species is questioning this traditional view. Here we discuss the evidence for non‐chordate RA signaling systems in the light of recent advances in our understanding of carotene (pro‐Vitamin A) metabolism and of the identification of potential RARs and members of the NR1 family in echinoderms and lophotrochozoan trematodes, respectively. We conclude, as have others before (Bertrand et al., 2004. Mol Biol Evol 21(10):1923–1937), that signaling by RA is more likely an ancestral feature of bilaterians than a chordate innovation. J. Exp. Zool. (Mol. Dev. Evol.) 310B:54–72, 2008. © 2006 Wiley‐Liss, Inc.
The minimum degree of Ramsey‐minimal graphs
Authors: Fox Jacob , Lin Kathy
Published: November 2006

We write H → G if every 2‐coloring of the edges of graph H contains a monochromatic copy of graph G. A graph H is G‐minimal if H → G, but for every proper subgraph H′ of H, H′ ↛ G. We define s(G) to be the minimum s such that there exists a G‐minimal graph with a vertex of degree s. We prove that s(Kk) = (k − 1)2 and s(Ka,b) = 2 min(a,b) − 1. We also pose several related open problems. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 167–177, 2007
Independent dominating sets and hamiltonian cycles
Authors: Haxell Penny , Seamone Ben , Verstraete Jacques
Published: November 2006

A graph is uniquely hamiltonian if it contains exactly one hamiltonian cycle. In this note we prove that there are no r‐regular uniquely hamiltonian graphs when r > 22. This improves upon earlier results of Thomassen. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 233–244, 2007
Seasonal characteristics of diurnal precipitation variation in Kraków (South Poland)
Authors: Twardosz Robert
Published: November 2006

This paper describes the diurnal cycle of liquid precipitation using the amplitude and phase of two precipitation characteristics: frequency and totals. A uniquely long set of uniform hourly precipitation data from Kraków (South Poland) was used. This vast and reliable basic material was collected by the author using pluviographic data covering the period 1886–2002. The role of precipitation type in forming the general diurnal cycle of precipitation was discussed. Two precipitation types, frontal and air mass, were taken into consideration. The role of particular air masses (polar maritime and polar continental) and atmospheric fronts (warm and cold fronts) in the 24‐h precipitation cycle was determined. The frontal and air mass precipitation events were identified using a documentation of synoptic situations by Niedźwiedź over the area of southern Poland for the 1951–2002 period.

Depending on the precipitation characteristic (frequency or totals), season of the year and precipitation type, the diurnal precipitation cycle may have one or two modes. The bimodality of the distribution occurs mainly for air mass precipitation. The morning maximum of precipitation frequency in all seasons of the year mimics the diurnal variation of precipitation in maritime polar air masses. Precipitation concentration in the afternoon hours is determined mainly by the intensity of processes in the cold front zone and in the homogeneous polar continental and maritime air masses. Significant differences in precipitation distribution in cold and warm fronts are connected with the time of precipitation concentration within the diurnal period. The type of atmospheric front determines the layout of precipitation clouds, intensity of precipitation formation and the velocity of front movement. Copyright © 2006 Royal Meteorological Society
From protection to innovation: BT's journey in corporate social responsibility
Authors: Blake Janet
Published: November 2006

British telecommunications giant BT demonstrates that corporate social responsibility (CSR) extends well beyond just being a “good guy.” The author traces the three stages of evolution of BT's CSR efforts—protector, builder, and innovator—noting the value drivers for the company and some of BT's initiatives and accomplishments at each stage. Several of BT's initiatives are examples of Europeancompanies' leading‐edge efforts in reducing greenhouse gas emissions and creating new “bottom of the pyramid” products and services for developing countries that are also sustainable solutions for reducing poverty. Having proven the business case time and again, BT now leverages its CSR competencies into marketplace innovations and sustainable solutions with long‐term benefits for us all. © 2006 BT Group plc.
Real Madrid football club: A new model of business organization for sports clubs in Spain
Authors: Callejo Miguel Blanco , Forcadell Francisco Javier
Published: November 2006

World soccer clubs, constrained by their inability to increase their income from their traditional businesses, have begun to adopt strategies to transform themselves into modern sports and media companies. Under the recent presidency of Florentino Pérez, the Spanish football club Real Madrid presents a good example of the application of this expanded vision. One of the fundamental pillars of this model has involved designing and implementing a new marketing strategy aimed at strengthening the value of the club's brand. The adoption of this model has resulted in a significant increase in income from marketing. Undeniably, in this area, Real Madrid has become the leader in world soccer. © 2006 Wiley Periodicals, Inc.
Evaluation of a novel biomaterial for intrasubstance muscle laceration repair
Authors: Crow Bradley D. , Haltom J. Douglas , Carson William L. , Greene Walter B. , Cook James L.
Published: November 2006

The authors compare the effects of small intestinal submucosa (SIS) treatment to suture repair with respect to histologic and functional outcomes for complete muscle lacerations in a rabbit model. The authors hypothesized that SIS treatment of full‐thickness muscle belly lacerations would significantly improve muscle function, strength, and regeneration compared to the current standard‐of‐care treatment. Muscle belly lacerations were created in the extensor digitorum longus (EDL) of both hind limbs of each rabbit. After randomization, lacerations were left unrepaired (n = 48) or repaired using a 4‐0 Prolene modified Kessler stitch (n = 48). A flap of SIS graft was sutured into half (n = 24 each) of the repaired and unrepaired muscles forming four study groups. Suture repair with SIS augmentation of complete muscle lacerations resulted in healed tissue that most closely resembled normal muscle in terms of morphology and function when compared to current standard‐of‐care treatments. Active force production in this group reached 79% of uninjured controls 12 weeks after surgery. SIS may have important clinical advantages over suture repair alone and warrants further clinical study. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
The balance between endotoxin accumulation and clearance during particle‐induced osteolysis in murine calvaria
Authors: Tatro Joscelyn M. , Taki Naoya , Islam Andrew S. , Goldberg Victor M. , Rimnac Clare M. , Doerschuk Claire M. , Stewart Matthew C. , Greenfield Edward M.
Published: November 2006

Bacterial endotoxin may contribute to aseptic loosening of orthopedic implants even in the absence of clinical or microbiological evidence of infection. One potential source of endotoxin during aseptic loosening is systemically circulating endotoxin, derived from intestinal flora, minor infections, or dental procedures, that may bind to wear particles. The current study demonstrates that systemically derived endotoxin accumulates when ‘endotoxin‐free’ titanium and polyethylene particles are implanted on murine calvaria. Time‐course experiments and experiments using germ‐free mice rule out the possibility that the observed endotoxin accumulation may be due to bacterial contamination. In contrast, endotoxin is cleared from titanium particles that originally carry high amounts of adherent endotoxin. The mechanism of endotoxin clearance is not dependent on induction of a respiratory burst. Taken together, these results indicate that a balance between endotoxin accumulation and endotoxin clearance controls the steady‐state level of endotoxin surrounding orthopedic wear particles implanted on murine calvaria. This balance may regulate the rate of osteolysis in the murine calvaria model as well as in patients with aseptic loosening. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Oxidative stress‐induced c‐Jun N‐terminal kinase (JNK) activation in tendon cells upregulates MMP1 mRNA and protein expression
Authors: Wang Fang , Murrell George A.C. , Wang Min‐Xia
Published: November 2006

To explore the potential mechanisms of tendon degeneration, we investigated the role of c‐Jun N‐terminal Kinase (JNK) activation and the regulation of matrix metalloproteinase 1 (MMP1) in tendon matrix degradation under oxidative stress. JNK and MMP1 activity in samples from normal and ruptured human supraspinatus tendons was evaluated by immunohistochemistry. Real‐time quantitative PCR was utilized to evaluate MMP1 mRNA expression and Western blotting for MMP1 and JNK protein detection. JNK activation and increased MMP1 activity were found in the torn human supraspinatus tendon tissue, as well as in human tendon cells under in vitro oxidative stress. Inhibition of JNK prevented MMP1 overexpression in oxidative stressed human tendon cells. Results from the current study indicated that stress activated JNK plays an important role in tendon matrix degradation, possibly through upregulating of MMP1. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
In vivo three‐dimensional skeletal alignment analysis of the hindfoot valgus deformity in patients with rheumatoid arthritis
Authors: Liu Hongbo , Sugamoto Kazuomi , Itohara Tomonobu , Tomita Tetsuya , Hashimoto Jun , Yoshikawa Hideki
Published: November 2006

The purpose of this study was to analyze the skeletal alignment of the hindfoot valgus deformity in patients with rheumatoid arthritis using bone models reconstructed from three‐dimensional computerized tomography data. Computed tomography was performed on 21 feet of patients with rheumatoid arthritis, and magnetic resonance imaging was taken of 10 normal feet of eight volunteers. An image processing system was used to create bone models and analyze the three‐dimensional displacement of the calcaneus, talus, navicular, and cuboid bones. With a standard coordinate system in the distal tibia and a local coordinate system in each bone of the hindfoot, three rotational parameters and three translational parameters were used to evaluate the relative displacement. The talus showed plantar flexion. Both the calcaneus and navicular bones had valgus and lateral shift displacements. However, the cuboid had no displacement relative to the calcaneus, and the navicular showed no displacement relative to the cuboid. The calcaneus, navicular, and cuboid bones have the same pattern of deformity in patients with rheumatoid arthritis. This three‐dimensional image‐based technique successfully quantified the hindfoot valgus deformity resulting from rheumatoid arthritis and is beneficial for better understanding the deformity pathomechanism. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Short‐term immunosuppression and surgical neoangiogenesis with host vessels maintains long‐term viability of vascularized bone allografts
Authors: Pelzer Michael , Larsen Mikko , Chung Yang‐Guk , Ohno Teruyasu , Platt Jeffrey L. , Friedrich Patricia F. , Bishop Allen T.
Published: November 2006

Currently available methods to reconstruct large skeletal defects have limitations. These include nonunion and stress fractures in structural allografts, and inability to match the size, shape, and/or strength of most recipient sites using vascularized fibular autografts. Prosthetic diaphyseal replacements may loosen or produce periprosthetic fractures. Transplantation of living allogenic bone would enable matching donor bone to the recipient site, combined with the desirable healing and remodeling properties of living bone. We propose a novel method by which the transplantation of such tissue might be done without the risks of life‐long immunosuppression, using surgical neoangiogenesis to develop a new host‐derived osseous blood supply. We performed vascularized femoral allografts from 86 female Dark Agouti donor rats to male Piebald Virol Glaxo recipients across a major histocompatibility (MHC) barrier. In addition to microvascular reconstruction of the nutrient vessel, we surgically implanted a host arteriovenous (AV) bundle into the medullary canal to promote host vessel neoangiogenesis. Independent variables included patency of the implanted AV bundle, and use of 2 weeks' FK‐506 immunosuppression. After 18 weeks, bone blood flow was measured, and neoangiogenic capillary density quantified. Bone blood flow and capillary density were significantly greater in transiently immunosuppressed recipients with a patent AV pedicle. We conclude that neoangiogenesis from implanted host‐derived AV‐bundles, combined with short‐term immunosuppression maintains blood flow in vascularized bone allografts, and offers potential for clinical application. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Regulation of implant surface cell adhesion: characterization and quantification of S‐phase primary osteoblast adhesions on biomimetic nanoscale substrates
Authors: Biggs Manus J.P. , Richards R.G. , Gadegaard N. , Wilkinson C.D.W. , Dalby M.J.
Published: November 2006

Integration of an orthopedic prosthesis for bone repair must be associated with osseointegration and implant fixation, an ideal that can be approached via topographical modification of the implant/bone interface. It is thought that osteoblasts use cellular extensions to gather spatial information of the topographical surroundings prior to adhesion formation and cellular flattening. Focal adhesions (FAs) are dynamic structures associated with the actin cytoskeleton that form adhesion plaques of clustered integrin receptors that function in coupling the cell cytoskeleton to the extracellular matrix (ECM). FAs contain structural and signalling molecules crucial to cell adhesion and survival. To investigate the effects of ordered nanotopographies on osteoblast adhesion formation, primary human osteoblasts (HOBs) were cultured on experimental substrates possessing a defined array of nanoscale pits. Nickel shims of controlled nanopit dimension and configuration were fabricated by electron beam lithography and transferred to polycarbonate (PC) discs via injection molding. Nanopits measuring 120 nm diameter and 100 nm in depth with 300 nm center–center spacing were fabricated in three unique geometric conformations: square, hexagonal, and near‐square (300 nm spaced pits in square pattern, but with ±50 nm disorder). Immunofluorescent labeling of vinculin allowed HOB adhesion complexes to be visualized and quantified by image software. Perhipheral adhesions as well as those within the perinuclear region were observed, and adhesion length and number were seen to vary on nanopit substrates relative to smooth PC. S‐phase cells on experimental substrates were identified with bromodeoxyuridine (BrdU) immunofluorescent detection, allowing adhesion quantification to be conducted on a uniform flattened population of cells within the S‐phase of the cell cycle. Findings of this study demonstrate the disruptive effects of ordered nanopits on adhesion formation and the role the conformation of nanofeatures plays in modulating these effects. Highly ordered arrays of nanopits resulted in decreased adhesion formation and a reduction in adhesion length, while introducing a degree of controlled disorder present in near‐square arrays, was shown to increase focal adhesion formation and size. HOBs were also shown to be affected morphologicaly by the presence and conformation of nanopits. Ordered arrays affected cellular spreading, and induced an elongated cellular phenotype, indicative of increased motility, while near‐square nanopit symmetries induced HOB spreading. It is postulated that nanopits affect osteoblast–substrate adhesion by directly or indirectly affecting adhesion complex formation, a phenomenon dependent on nanopit dimension and conformation. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:273–282, 2007
Raman identification of green and blue pigments in Etruscan polychromes on architectural terracotta panels
Authors: Bordignon F. , Postorino P. , Dore P. , Trojsi G.
Published: November 2006

Micro‐Raman measurements were performed on two Etruscan polychromes on architectural terracotta panels now on display at the Villa Giulia Etruscan Museum in Rome. These painted panels, dated from 530 to 520 B.C., are of particular interest because of the unusual presence of green and blue layers. Etruscans in the Archaic Age indeed mainly used white, red, and black colours for painted terracotta panels. Raman spectra allowed the analytical identification of green (malachite) and blue (Egyptian blue) pigments employed by Etruscans for this kind of artistic production. This finding provides evidence for a larger use of malachite and Egyptian blue, previously well documented only in Etruscan wall paintings. The use of different pigments to obtain different colour tones has been also observed. Egyptian blue is indeed mixed with malachite to obtain different green tones, and a black pigment seems to have been applied over the Egyptian blue layer to obtain a dark blue tone. Copyright © 2006 John Wiley & Sons, Ltd.
IR, Raman and SERS spectra of 5‐sulphosalicylic acid dihydrate
Authors: Varghese Hema Tresa , Panicker C. Yohannan , Philip Daizy
Published: November 2006

IR, Raman and surface‐enhanced Raman scattering (SERS) spectra of 5‐sulphosalicylic acid were recorded and analysed. The vibrational wavenumbers were computed by density functional theoretical (DFT) method using B3LYP/6–31G* basis. The bands due to the stretching modes CO, CS and SO2 are intense in the SERS spectrum. The CH stretching mode also appears in the SERS spectrum. The molecule is found to adsorb through both the carboxyl and sulphonyl groups. A possible tilted orientation of the molecule is suggested. Copyright © 2006 John Wiley & Sons, Ltd.
Monocarboxylate transporter expression is associated with the absorption of benzoic acid in human intestinal epithelial cells
Authors: Haughton Emma , Clifford Michael N , Sharp Paul
Published: November 2006

A diet rich in fruit and vegetables is associated with a decreased risk of developing a number of chronic diseases including colon cancer. The active components of the diet which exert these protective effects are unknown but may include small aromatic and phenolic acids. To elicit a physiological response, these acids must first be absorbed by the intestinal epithelium and the present study has focussed on one potential absorptive pathway—the monocarboxylate transporter MCT1. Using Caco‐2 cells (a human intestinal cell line) we have established that benzoic acid uptake is pH‐dependent (resulting in intracellular acidification) and is enhanced in cells expressing higher levels of MCT1 protein. A number of monohydroxybenzoic acids (including salicylic acid) also induced a decrease in intracellular pH which was of a similar magnitude to that elicited by benzoic acid itself, suggesting that they may all be substrates for the same transport pathway. The role of these small organic acids in maintaining normal cell physiology remains to be fully explored. Copyright © 2006 Society of Chemical Industry
Effects of storage conditions on the accumulation of ferulic acid derivatives in white asparagus cell walls
Authors: Jaramillo Sara , Rodríguez Rocío , Jiménez Ana , Guillén Rafael , Fernández‐Bolaños Juan , Heredia Antonia
Published: November 2006

White asparagus cell walls have shown to contain important amounts of phenolics, including ferulic acid and its dimers and trimers. It has been suggested that these phenolic compounds are mainly responsible for cross‐linking the different cell wall polymers related to asparagus hardening. During post‐harvest storage, the asparagus texture and the amount of cell wall phenolics increased significantly. In the present work, the effect of post‐harvest storage conditions on the accumulation of ferulic acid and its derivatives has been investigated. Three different storage conditions were used: keeping the spears in aerobic conditions at room temperature (ART) and at 4 °C (A4 °C), and in anaerobic conditions at room temperature (AnRT). A direct relationship between phenol accumulation and increases in texture was observed, and these changes are dependent on temperature and storage atmosphere. An increase in temperature led to a higher amount of cell wall phenolics and the absence of oxygen in the storage atmosphere delayed their accumulation. The evolution of ferulic dimers during the three storage conditions suggests a relevant role of 8‐O‐4′‐diFA and 8,5′‐BAdiFA in white asparagus hardening. Copyright © 2006 Society of Chemical Industry
Blue and red light combination LED phototherapy for acne vulgaris in patients with skin phototype IV
Authors: Lee Seung Yoon , You Chung Eui , Park Mi Youn
Published: November 2006

Background and Objectives

Blue light is effective for acne treatment, inducing photodynamic destruction of Propionibacterium acnes (P. acnes). This study was designed to investigate the efficacy of combined blue and red light‐emitting diode (LED) phototherapy for acne vulgaris.

Materials and Methods

Twenty‐four patients with mild to moderately severe facial acne were treated with quasimonochromatic LED devices, alternating blue (415 nm) and red (633 nm) light. The treatment was performed twice a week for 4 weeks. Objective assays of the skin condition were carried out before and after treatment at each treatment session. Clinical assessments were conducted before treatment, after the 2nd, 4th, and 6th treatment sessions and at 2, 4, and 8 weeks after the final treatment by grading and lesion counting.

Results

The final mean percentage improvements in non‐inflammatory and inflammatory lesions were 34.28% and 77.93%, respectively. Instrumental measurements indicated that the melanin levels significantly decreased after treatment. Brightened skin tone and improved skin texture were spontaneously reported by 14 patients.

Conclusion

Blue and red light combination LED phototherapy is an effective, safe and non‐painful treatment for mild to moderately severe acne vulgaris, particularly for papulopustular acne lesions. Lasers Surg. Med. 39:180–188, 2007. © 2007 Wiley‐Liss, Inc.
Nanoindentation and Morphological Studies of Epoxy Nanocomposites
Authors: Shen Lu , Wang Lei , Liu Tianxi , He Chaobin
Published: November 2006

Summary: This paper investigates the mechanical properties of the epoxy–organoclay nanocomposites by the nanoindentation technique. The nanocomposites were prepared by in situ polymerization and a mixture of exfoliated and intercalated composites structure was obtained as evidenced by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The hardness, elastic modulus, and the creep behavior of the nanocomposites have been evaluated as a function of clay concentration. It has been found that incorporation of 7.5 wt.‐% of clay nanofiller enhances the elastic modulus and hardness of the epoxy matrix by about 20 and 6%, respectively. The elastic modulus data calculated from indentation experiments are comparable with those obtained from a tensile test. An optimum clay loading level was found to be 2.5 wt.‐% to maximum enhance the creep resistance of the epoxy matrix. The lowered creep resistance with higher clay loading could be due to the reduced crosslinking density near the clay surface caused by the plasticizing effect from the pending of alkyl ammonium chains on the clay surface. An attempt has been made to correlate the fracture toughness of the nanocomposites with the ratio of modulus to hardness obtained from nanoindentation experiments.

Ratio of modulus to hardness (E/H) and the fracture toughness (KIC) versus clay loading for the epoxy nanocomposites.

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Ratio of modulus to hardness (E/H) and the fracture toughness (KIC) versus clay loading for the epoxy nanocomposites.
Manipulation of the Microstructure of Injection Moldings in a Special Mold and Their Mechanical Behavior
Authors: Silva Cristina A. , Viana Júlio C. , Cunha António M.
Published: November 2006

Summary: In this work, the relationships between the microstructure and the mechanical properties of injection moldings using a special mold for manipulation of their microstructure are studied. Distinct molding microstructures were obtained by superimposing a mold surface rotation action in different rotation modes during the filling stage of a center‐gated disk. For this, disks were injected in the special molding tool—the RCE mold—with distinct filling sequences (stationary, continuous, stepped, and pulsed rotation modes) for two different thicknesses (1.5 and 2.5 mm) in a propylene homopolymer. This enables the development of a wide range of microstructures, which were characterized by polarized light microscopy. The mechanical behavior of the moldings was assessed by tensile and impact testing. The results are presented in terms of the relationships between the developed microstructure and the assessed mechanical properties. The imposition of a rotation action of the molds wall influences the development of the microstructure, and hence the mechanical properties of the moldings.

Effect of the rotating mode: stationary, continuous (R), stepped (RS), and pulsed modes (RC), at 150 rpm on the microstructure at position P2 (cuts to transversal flow direction). Thickness: 1.50 mm.

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Effect of the rotating mode: stationary, continuous (R), stepped (RS), and pulsed modes (RC), at 150 rpm on the microstructure at position P2 (cuts to transversal flow direction). Thickness: 1.50 mm.
Miscibility in Blends of Isotactic/Syndiotactic Polystyrenes at Melt or Quenched Amorphous Solid State
Authors: Li Shu Hsien , Woo Eamor M.
Published: November 2006

Summary: Miscibility in amorphous phase and behavior in a crystalline phase of blends of two semicrystalline and isomeric polymers, isotactic polystyrene (iPS) and syndiotactic polystyrene (sPS), was probed. Optical and scanning electron microscopy results indicate no discernible heterogeneity in iPS/sPS blends in either melt state or rapidly quenched amorphous super‐cooled state, while the Tg behavior of the quenched amorphous blends shows an intimately mixed state of two polymer chains. The crystal forms of the blends were further analyzed to provide additional evidence of miscibility in the amorphous domain. The sPS in the iPS/sPS blends upon melt crystallization was found to predominantly exist as the more stable β‐form (rather than mixed β‐form and α‐form in neat sPS), which also suggests evidence of miscibility in the iPS/sPS blends. The melting behavior of semicrystalline sPS in the iPS/sPS mixtures was analyzed using the Flory‐Huggins approach for estimation of interactions. By measuring the equilibrium melting point of the higher‐melting sPS species in the sPS/iPS blends, a small negative value, for the interaction parameter (χ ≈ −0.11) was found. Further, by introducing a third polymer, poly(2,6‐dimethyl‐p‐phenylene oxide) (PPO), a ternary iPS/sPS/PPO blend system was also proven miscible, which constituted a further test for stable phase miscibility in the iPS/sPS blend. General nature of miscibility in blends composed of two crystalline isomeric polymers is discussed. Issues in dealing with blends of polymers of the same chemical repeat unit but different tacticities were addressed.

X‐ray diffractograms for neat sPS and iPS/sPS blends, each having been isothermally crystallized at 245 °C for 4 h.

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X‐ray diffractograms for neat sPS and iPS/sPS blends, each having been isothermally crystallized at 245 °C for 4 h.
Chemical Recycling of PET by Glycolysis: Polymerization and Characterization of the Dimethacrylated Glycolysate
Authors: Karayannidis George P. , Nikolaidis Alexandros K. , Sideridou Irini D. , Bikiaris Dimitris N. , Achilias Dimitris S.
Published: November 2006

Summary: In the framework of chemical recycling of polymers, leading to the generation of secondary value‐added products, PET flakes taken from post‐consumer soft drink bottles, were glycolyzed with DEG. The oligomers obtained were analyzed for their molecular weight and characterized by FT‐IR and POM. Subsequently, dimethacrylated oligoesters of PET glycolysate (PET‐GLY‐DMA) were synthesized by methacrylation of the glycolyzed PET product. The resulted monomer PET‐GLY‐DMA was studied by FT‐IR, POM and DSC. Thermal polymerization of this monomer was carried out at 80 °C in the presence of benzoyl peroxide as initiator. A UV‐curable formulation was also prepared on the basis of neat PET‐GLY‐DMA, as well as by mixing PET‐GLY‐DMA with styrene, using DMPA as photoinitiator. Nanoparticles of SiO2 were dispersed into PET‐GLY‐DMA/styrene copolymers as reinforcing agents and the mechanical properties of resins formed were studied.

Preparation of methacrylated PET glycolysate.

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Preparation of methacrylated PET glycolysate.
Influence of Carbon‐Black Nanoparticles on Poly(butylene terephthalate) Fractionated Crystallization in Bicomponent Poly(butylene terephthalate)/Poly[ethylene‐co‐(ethyl acrylate)] Blends
Authors: Pillin Isabelle , Feller Jean‐François
Published: November 2006

Summary: The crystallization of the PBT minor phase in an EEA continuous matrix has been studied by DSC and SEM. When PBT is the minor phase, PBT crystallizes at a lower temperature, as expected, near Tc,f1 = 105 °C. Introducing different CB nanoparticles into the EEA continuous phase at contents increasing from 0.02 to 5 wt.‐% leads to important modifications of the PBT crystallization. A new PBT exotherm appears at Tc,f2 = 144 °C on the addition of CB, becoming really visible at Tc,f3 = 158 °C and finally moving to Tc,n = 185 °C at high content. The areas corresponding to these new peaks were found to increase to the detriment of that of the fractionated crystallization at Tc,f1 = 105 °C. Morphological studies and interfacial tension measurements were made to understand the surprising activity of the CB. Moreover, the substitution of the EEA phase with the less polar LLDPE confirmed the importance of the strong interactions developed by EEA with CB aggregates.

Melting and recrystallization DSC curves for the PBT/EEA 60/40 blend.

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Melting and recrystallization DSC curves for the PBT/EEA 60/40 blend.