bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermoforming of tracheal cartilage: Viability, shape change, and mechanical behavior
Authors: Chae Yongseok , Protsenko Dmitriy , Holden Paul K. , Chlebicki Cara , Wong Brian J.F. 
Published: September 2008

AbstractBackground and ObjectivesTrauma, emergent tracheostomy, and prolonged intubation are common causes of severe deformation and narrowing of the trachea. Laser technology may be used to reshape tracheal cartilage using minimally invasive methods. The objectives of this study were to determine: (1) the dependence of tracheal cartilage shape change on temperature and laser dosimetry using heated saline bath immersion and laser irradiation, respectively, (2) the effect of temperature on the mechanical behavior of cartilage, and (3) tissue viability as a function of laser dosimetry.Materials and MethodsEx vivo rabbit trachea cartilage specimens were bent and secured around a cylinder (6 mm), and then immersed in a saline bath (45 and 72°C) for 5–100 seconds. In separate experiments, tracheal specimens were irradiated with a diode laser (λ = 1.45 µm, 220–400 J/cm2). Mechanical analysis was then used to determine the elastic modulus in tension after irradiation. Fluorescent viability assays combined with laser scanning confocal microscopy (LSCM) were employed to image and identify thermal injury regions.ResultsShape change transition zones, between 62 and 66°C in the saline heating bath and above power densities of 350 J/cm2(peak temperatures 65±10°C) for laser irradiation were identified. Above these zones, the elastic moduli were higher (8.2±4 MPa) than at lower temperatures (4.5±3 MPa). LSCM identified significant loss of viable chondrocytes within the laser‐irradiation zones.ConclusionOur results indicate a change in mechanical properties occurs with laser irradiation and further demonstrates that significant thermal damage is concurrent with clinically relevant shape change in the elastic cartilage tissues of the rabbit trachea using the present laser and dosimetry parameters. Lesers Surg. Med. 40:550–561, 2008. © 2008 Wiley‐Liss, Inc.
Disruption of the blood–brain barrier following ALA‐mediated photodynamic therapy
Authors: Hirschberg Henry , Uzal Francisco A. , Chighvinadze David , Zhang Michelle J. , Peng Qian , Madsen Steen J. 
Published: September 2008

AbstractBackground and ObjectivePhotodynamic therapy (PDT) is a local antineoplastic treatment with the potential for tumor cell specificity. PDT using either hematoporphyrin derivatives or 5‐aminolevulinic acid (ALA) has been reported to induce brain edema indicating disruption of the blood–brain barrier (BBB). We have evaluated the ability of ALA‐mediated PDT to open the BBB in rats. This will permit access of chemotherapeutic agents to brain tumor cells remaining in the resection cavity wall, but limit their penetration into normal brain remote from the site of illumination.Study Design/Materials and MethodsALA‐PDT was performed on non‐tumor bearing inbred Fischer rats at increasing fluence levels. Contrast T1‐weighted high field (3 T) magnetic resonance imaging (MRI) scans were used to monitor the degree of BBB disruption which could be inferred from the intensity and volume of the contrast agent visualized.ResultsPDT at increasing fluence levels between 9 and 26 J demonstrated an increasing contrast flow rate. A similar increased contrast volume was observed with increasing fluence rates. The BBB was found to be disrupted 2 hours following PDT and 80–100% restored 72 hours later at the lowest fluence level. No effect on the BBB was observed if 26 J of light was given in the absence of ALA.ConclusionALA‐PDT was highly effective in opening the BBB in a localized region of the brain. The degradation of the BBB was temporary in nature at fluence levels of 9 J, opening rapidly following treatment and significantly restored during the next 72 hours. No signs of tissue damage were seen on histological sections at this fluence level. However, higher fluences did demonstrate permanent tissue changes localized in the immediate vicinity of the light source. Lesers Surg. Med. 40:535–542, 2008. © 2008 Wiley‐Liss, Inc.
Temporary hair removal by low fluence photoepilation: Histological study on biopsies and cultured human hair follicles
Authors: Roosen Guido F. , Westgate Gillian E. , Philpott Mike , Berretty Paul J.M. , Nuijs Tom (A.M.) , Bjerring Peter 
Published: September 2008

AbstractBackground and ObjectivesWe have recently shown that repeated low fluence photoepilation (LFP) with intense pulsed light (IPL) leads to effective hair removal, which is fully reversible. Contrary to permanent hair removal treatments, LFP does not induce severe damage to the hair follicle. The purpose of the current study is to investigate the impact of LFP on the structure and the physiology of the hair follicle.Study Design/Materials and MethodsSingle pulses of IPL with a fluence of 9 J/cm2 and duration of 15 milliseconds were applied to one lower leg of 12 female subjects, followed by taking a single biopsy per person, either immediately, or after 3 or 7 days. Additionally, we present a novel approach to examine the effects of LFP, in which ex vivo hairy human scalp skin was exposed to IPL pulses with the same parameters as above, followed by isolation and culturing of the hair follicles over several days. Samples were examined histologically and morphologically.ResultsThe majority of the cultured follicles that had been exposed to LFP treatment showed a marked treatment effect. The melanin containing part of the hair follicle bulb was the target and a catagen‐like transformation was observed demonstrating that hair formation had ceased. The other follicles that had been exposed to LFP showed a less strong or no response. The skin biopsies also revealed that the melanin‐rich region of the hair follicle bulb matrix was targeted; other parts of the follicle and the skin remained unaffected. Catagen/telogen hair follicles were visible with unusual melanin clumping, indicating this cycle phase was induced by the IPL treatment.ConclusionsLow fluence photoepilation targets the pigmented matrix area of the anagen hair follicle bulb, causing a highly localized but mild trauma that interrupts the hair cycle, induces a catagen‐like state and eventually leads to temporary loss of the hair. Lesers Surg. Med. 40:520–528, 2008. © 2008 Wiley‐Liss, Inc.
Oncogenic and ligand‐dependent activation of KIT/PDGFRA in surgical samples of imatinib‐treated gastrointestinal stromal tumours (GISTs)
Authors: Negri T , Bozzi F , Conca E , Brich S , Gronchi A , Bertulli R , Fumagalli E , Pierotti MA , Tamborini E , Pilotti S 
Published: September 2008

AbstractAs the range of receptor tyrosine kinase (RTK) inhibitors widens, a detailed understanding of the activating mechanisms of KIT/platelet‐derived growth factor receptor (PDGFR)A and the related downstream pathways involved in the development and maintenance of GISTs is becoming increasingly important. We analysed areas with different histological response ratios in surgical specimens taken from imatinib‐treated and untreated GIST patients in order to investigate KIT and PDGFRA expression/activation, the presence of their cognate ligands and the activation of downstream signalling, by means of biochemistry, immunohistochemistry and flow cytometry. All of the cases showed KIT and PDGFRA co‐expression. In addition to the oncogenic activation of mutated receptors, activation of wild‐type KIT and wild‐type PDGFRA, sustained by heterodimerization and an autocrine–paracrine loop, was demonstrated by the presence of their specific ligands, stem cell factor (SCF) and PDGFA. To confirm RTK activation further, all of the samples (including those with the highest regression ratios) were investigated for downstream effectors, and all proved to have activated downstream signalling. The results show that after the mutated receptors are switched off, heterologous wild‐type receptors become important in imatinib‐treated GISTs as a means of maintaining signalling activation. Taken together, our findings suggest that drugs targeting wild‐type receptors should be tested in imatinib‐treated GIST patients. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
E2Fs mediate a fundamental cell‐cycle deregulation in high‐grade serous ovarian carcinomas
Authors: De Meyer T , Bijsmans ITGW , Van de Vijver KK , Bekaert S , Oosting J , Van Criekinge W , van Engeland M , Sieben NLG 
Published: September 2008

AbstractSeveral studies described a role for the E2F/Rb pathway in ovarian serous carcinomas (SCAs). Since E2F/Rb pathway deregulation is a general hallmark of human cancer, it remains unclear whether this deregulation is of particular importance in SCAs or whether it reflects a common oncological feature. Here, we have clarified this issue by the examination of microarray expression profiles of SCAs and particularly by the comparison with another, less malignant, ovarian cancer type, serous borderline tumours (SBTs). Results were validated by quantitative RT‐PCR, both on the microarray samples and on an independent panel, and TP53 mutation analysis was performed. This integrated analysis revealed a significant increase in the expression of the transcription factors E2F1 and E2F3 in SCAs, when compared to SBTs. This was associated with vast overexpression of E2F target genes in SCAs compared to SBTs. High‐grade SCAs in particular exhibited a major deregulated E2F target expression pattern. Generally, overexpression of E2F targets in SCAs appeared to be well structured since those targets considered negative regulators of the cell cycle or promoters of apoptosis were usually not overexpressed in SCAs. Similar to E2F target deregulation, TP53 mutations were identified in SCA3s, to a lesser extent in SCA1s, and not in SBTs. These results suggest that a structured, generally up‐regulated E2F transcription factor activity is associated with a global cell‐cycle disturbance in high‐grade SCAs and exceeds typical E2F/Rb pathway disruption in tumours, at least compared with SBTs. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Preimplantation genetic diagnosis of Morquio disease
Authors: Qubbaj Wafa , Al‐Aqeel Aida I. , Al‐Hassnan Zuhair , Al‐Duraihim Adel , Awartani Khalid , Al‐Rejjal Rafat , Coskun Serdar 
Published: September 2008

AbstractObjectivesMorquio syndrome is an autosomal recessive disease and mutations in the N‐acetylgalactosamine 6‐sulfate sulfatase (GALNS) gene cause Morquio type A disease. Preimplantation genetic diagnosis (PGD), an early form of prenatal diagnosis for couples at risk of transmitting inherited diseases, was applied to prevent transmission of this disease.MethodsA couple with three affected children, having homozygous W159C (p. Trp 159 Cys) mutation in GALNS gene, underwent in vitro fertilization (IVF) treatment and PGD. Mutation analyses from the embryos were performed following whole genome amplification of single blastomeres using multiple displacement amplification (MDA).ResultsThree embryos were diagnosed as normal and two were transferred on day 4. The cycle resulted in a pregnancy and a live birth of a carrier male infant. Genetic haplotyping analysis of the infant and the leftover MDA samples enabled us to determine which embryo was implanted. The discrepancy in results was explained by allele dropout (ADO) of the mutant allele from the MDA product.ConclusionsA feasible strategy for PGD of Morquio disease including whole genome amplification by MDA and the use of preimplantation genetic haplotyping is described. MDA product archiving will be useful for future investigations if needed. Copyright © 2008 John Wiley & Sons, Ltd.
In situsynthesis of bone‐like hydroxyapatite/polyamide 6 nanocomposites
Authors: Li Lanjie , Yang Guisheng 
Published: September 2008

AbstractBACKGROUND:Polymer/hydroxyapatite (HA) nanocomposites have emerged in recent years as a new class of biomaterials that can be used as artificial bone. Compared to pure HA or HA‐based bioceramics, and metallic implants, they exhibit good plasticity, improved toughness and good mechanical compatibility with natural bone. Compared to their microcomposite counterparts and the pristine polymer matrix, they show increased tensile strength and modulus, and enhanced bioactivity.RESULTS:In this study, polyamide 6 (PA6)/nanoscale HA (n‐HA) nanocomposites were prepared viain situhydrolytic ring‐opening polymerization of ε‐caprolactam in the presence of newly synthesized n‐HA aqueous slurry. The synthesized n‐HA, which is similar to bone apatite in chemical composition, microscopic morphology and phase composition, dispersed uniformly in the composites even if its loading was up to 60 wt%. The PA6/n‐HA composites show a similarity to natural bone in chemical composition to a certain extent. Mechanical tests show that the composites are reinforced considerably by the incorporation of needle‐like n‐HA, and the composites have mechanical properties near to those of natural bone.CONCLUSION:The PA6/n‐HA nanocomposite with high n‐HA content shows a similarity to natural bone in terms of chemistry and mechanical properties. This makes it a possible candidate for biomaterials suitable for bone repair or fixation. Copyright © 2008 Society of Chemical Industry
Kinetic study on the living/controlled cationic polymerization of p‐methoxystyrene coinitiated by tris(pentafluorophenyl)borane
Authors: Radchenko Alexei V. , Kostjuk Sergei V. , Vasilenko Irina V. , Ganachaud François , Kaputsky Fyodor N. , Guillaneuf Yohann 
Published: September 2008

AbstractA kinetic study of the living cationic polymerization of p‐methoxystyrene using 1‐(4‐methoxyphenyl)ethanol (1)/B(C6F5)3 initiating system in a mixture of CH3CN with CH2Cl2 1:1 (v/v) at room temperature was carried out utilizing a wide variety of conditions. The polymerization proceeded in a living fashion even in the presence of a large amount of water ([H2O]/[B(C6F5)3] ratio up to 20) to afford polymers whose Mn increased in direct proportion to monomer conversion with fairly narrow MWDs (Mw/Mn ≤ 1.3). The investigation revealed that the rate of polymerization was first‐order in B(C6F5)3 concentration, while a negative order in H2O concentration close to −2 was obtained. It was also found that the rate of polymerization decreased with lowering temperature, which could be attributed to a decreased concentration in free Lewis acid, the true coinitiator of polymerization. A mechanistic scheme to explain the kinetic behavior of living p‐methoxystyrene polymerization is proposed, which has been validated by PREDICI simulation on multiple‐data curves obtained by 1H NMR in situ polymerization experiment. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6928–6939, 2008
Preparation of polypyrrole‐graft‐poly(N‐isopropylacrylamide)/silver nanocomposites from pyrrolyl‐capped macromonomer by AgNO3 and their stimuli responsibility of light emission
Authors: Sun Xiao‐Li , He Wei‐Dong , Li Jian , He Ning , Han Shou‐Chen , Li Li‐Ying 
Published: September 2008

AbstractPyrrolyl‐capped poly(N‐isopropylacrylamide) macromonomers (Py‐PNIPAM) were prepared through reversible addition‐fragmentation‐transfer polymerization with benzyl 1‐pyrrolylcarbodithioate as chain‐transfer agent. Polymerizations of Py‐PNIPAM with/without pyrrole using AgNO3 as oxidizing agent and dimethylforamide as solvent resulted in graft copolymers of polypyrrole‐graft‐poly(N‐isopropylacrylamide) (PPy‐g‐PNIPAM) as well as silver nanoparticles, leading to the formation of PPy‐g‐PNIPAM/silver nanocomposites. The resulting nanocomposites were soluble in water when the content of PPy was low, and when the molar ratio of Py/Py‐PNIPAM increased to 30, the resulting products became insoluble in water. The resulting nanocomposites had special optical properties because of PPy as well as the temperature‐responsible PNIPAM. The chemical structure and composition of nanocomposite were characterized by 1H nuclear magnetic resonance spectroscopy, gel permeation chromatograms, fourier transform infrared spectroscopy, and X‐ray diffraction. Their optical properties were characterized by UV–vis and fluorescence spectroscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6950–6960, 2008
Imidazolium ionic liquids with short polyoxyethylene chains
Authors: Biedroń Tadeusz , Kubisa Przemysław 
Published: September 2008

AbstractIt has been observed by us earlier that imidazolium ionic liquids ([bmim][BF4] react with paraformaldehyde giving in nearly quantitative yield imidazolium ionic liquids substituted at 2‐position with hydroxymethyl group ([bhmim][BF4]). In this article, we describe the application of those ionic liquids (after converting hydroxyl group into alkoxide anion by reaction with sodium hydride) as initiators for anionic polymerization of ethylene oxide (EO). Up to DPn ∼ 30 polymerization proceeds without side reactions, and the product is exclusively low‐molecular‐weight polyoxyethylene containing imidazolium head group (POE‐IL) with DPn equal to [EO]/[bhmim] ratio. By increasing [EO]/[bhmim] ratio further, side reaction start to interfere, and macromolecules that does not contain imidazolium head groups are also formed, as evidenced by analysis of MALDI TOF spectra. Blending of POE‐IL with high‐molecular‐weight POE leads to significant reduction of crystallinity of POE. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6961–6968, 2008
Modelling binary mixtures of herbicides in populations resistant to one of the components: evaluation for resistance management
Authors: Jacquemin Bertrand , Gasquez Jacques , Reboud Xavier 
Published: September 2008

AbstractBACKGROUND: Herbicide mixtures are commonly proposed to delay the selection of herbicide resistance in susceptible populations (called the SM strategy). However, in practice, herbicide mixtures are often used when resistance to one of the two active ingredients has already been detected in the targeted population (called the RM strategy). It is doubtful whether such a practice can select against resistance, as the corresponding selection pressure is still exerted. As a consequence, the effect of mixtures on the evolution of an already detected resistance to one of the herbicides in the combination remains largely unexplored. In the present work, a simple model was developed to explore further the necessary and sufficient conditions under which a binary RM strategy might stabilise or even reduce resistance frequency.RESULTS: Covering the hypothetical largest range of parameters, 39% of 9000 random simulations attest that the RM strategy might theoretically reduce resistance frequency. When strong enough, high genetic cost of resistance, negative cross‐resistance between the herbicides associated in the mixture and reduced selection differential between resistant and susceptible plants can counterbalance the resistance advantage to one of the two applied herbicides. However, the required conditions for an RM strategy to ensure resistance containment in natural conditions seldom overlap with experimental parameter estimates given in the literature.CONCLUSION: It is concluded that the sufficient conditions for an RM strategy to be effective would rarely be encountered. As a consequence, the strategy of formulating mixtures with herbicides for which resistance has already been detected should be avoided. Copyright © 2008 Society of Chemical Industry
Monolithic integrated microring resonators: The fundamental building block towards “dense” photonic integration
Authors: Mikroulis S. , Syvridis D. 
Published: September 2008

AbstractSemiconductor microring resonators are excellent fundamental building blocks for fabrication of Optoelectronic Integrated Circuits (OEICs), due to their large third‐order nonlinearities enhanced by the resonance effect, compactness which can lead to ultrahigh device integration densities and monolithic integration capability. In this work the key role of the fundamental design parameters will be highlighted in order to evaluate microring resonators for novel photonic function applications. These applications include but not limited to wavelength conversion, all‐optical regeneration, all‐optical logic, and information transmission and the dependence of each device's performance on the above parameters will be analyzed emphasizing on the induced fabrication limitations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Charge trapping and de‐trapping in Si‐nanoparticles embedded in silicon oxide films
Authors: Morales‐Sánchez A. , Barreto J. , Domínguez C. , Aceves M. , Yu Z. , Luna J. A. 
Published: September 2008

AbstractElectrical properties of silicon nanoparticles (Si‐np's) embedded in a silicon oxide matrix were studied using MOS‐like structures. Si‐np's were created after silicon rich oxide (SRO) films were thermally annealed at 1100 °C. Capacitance–voltage (C–V) characteristics showed downward and upward peaks in the accumulation region. Current–voltage (I–V) measurements exhibited current valleys and downward and upward peaks. Current versus time (I–t) measurements were also done at a negative constant gate voltage. A switching behaviour between two current states (ON and OFF) was observed. These effects have been related to the charge trapping and de‐trapping of the Si‐np's embedded in the SRO films. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ideality factor dependence of capacitance and reverse current noise in Au/n‐GaAs Schottky diodes with embedded self‐assembled InAs quantum dots
Authors: Arpatzanis N. , Hastas N. A. , Dimitriadis C. A. , Charitidis C. , Song J. D. , Choi W. J. , Lee J. I. 
Published: September 2008

AbstractThe trap properties of Au/n‐GaAs Schottky diodes with embedded InAs quantum dots (QDs) and different ideality factors were studied by capacitance‐voltage (C‐V) and low‐frequency noise (LFN) measurements in the reverse bias regime. The reverse current noise spectra show 1/f behaviour and g‐r noise, attributed to uniformly distributed traps in energy or to a discrete trap level in the energy band‐gap of the GaAs capping layer, respectively. The Schottky contact performance or characteristics is closely related with the level of these noise sources. The C‐V characteristics indicate the existence of traps with Gaussian energy distribution in the GaAs capping layer and in the InAs QDs layer. From analysis of the C‐V characteristics, the density and the activation energy of these trap distributions are determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design to improve the capacitive contact quality in piezoelectric actuation
Authors: Achkar Hikmat , Peyrou David , Pennec Fabienne , Al Ahmad Mahmoud , Pons Patrick , Plana Robert 
Published: September 2008

AbstractRF MEMS switches with piezoelectric actuation permits us to obtain a reliable switch relative to electrostatic actuated switches since the dielectric charging is reduced and fast respond. The problem here is the deformation induced by the actuation is transmitted to the capacitor plate and by consequences; we lose in the value of capacitance in the down state due to the air gap. A study of the air gap effect on the capacitance value in the down state is done in the first part, showing the importance of flatness in capacitor plate designs. The design that is described in this paper, deals with the point of the application of the force in order to flatten the contact between the electrodes forming the capacitor. An analytical model describing the deformation of the switch was developed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)