bluuebunny/crossref_metadata_2025_split huggingface dataset:
A chromatin immunoprecipitation screen in mouse keratinocytes reveals Runx1 as a direct transcriptional target of ΔNp63
Authors: Ortt Kori , Raveh Eli , Gat Uri , Sinha Satrajit 
Published: February 2008

AbstractDevelopment of the skin epidermis and appendages such as hair follicles involves coordinated processes of keratinocyte proliferation and differentiation. The transcription factor p63 plays a critical role in these steps as evident by a complete lack of these structures in p63 null mice. The p63 gene encodes for two proteins TAp63 and ΔNp63, the latter being the more prevalent and dominant isoform expressed in keratinocytes. Although numerous p63 target genes have been identified, these studies have been limited to transformed human keratinocyte cell lines. Here, we have employed a genomic screening approach of chromatin immunoprecipitation (ChIP) coupled with an enrichment strategy to identify ΔNp63 response elements in primary mouse keratinocytes. Analysis of p63‐ChIP‐derived DNA segments has revealed more than 100 potential target genes including novel as well as mouse counterparts of established human p63 targets. Among these is Runx1, a transcription factor important for hair follicle development. We demonstrate that ΔNp63 binds to a p63‐response element located within a well‐conserved enhancer of the Runx1 gene. Furthermore, siRNA mediated reduction of ΔNp63 in mouse keratinocytes reduces Runx1 expression. Consistent with this, endogenous Runx1 levels are lower in the skin of p63+/− animals as compared to wild type animals. Lastly, we demonstrate that ΔNp63 and Runx1 are co‐expressed in specific compartments of the hair follicle in a dynamic fashion. Taken together our data demonstrate that p63 directly regulates Runx1 gene expression through a novel enhancer element and suggests a role for these two transcription factors in dictating skin keratinocyte and appendage development. J. Cell. Biochem. 104: 1204–1219, 2008. © 2008 Wiley‐Liss, Inc.
Pathway crosstalk between Ras/Raf and PI3K in promotion of M‐CSF‐induced MEK/ERK‐mediated osteoclast survival
Authors: Bradley Elizabeth W. , Ruan Ming M. , Vrable Anne , Oursler Merry Jo 
Published: February 2008

AbstractWhile M‐CSF‐mediated MEK/ERK activation promotes osteoclast survival, the signaling pathway by which M‐CSF activates MEK/ERK is unresolved. Functions for PI3K, Ras, and Raf have been implicated in support of osteoclast survival, although interaction between these signaling components has not been examined. Therefore, the interplay between PI3K, Ras and Raf in M‐CSF‐promoted MEK/ERK activation and osteoclast survival was investigated. M‐CSF activates Ras to coordinate activation of PI3K and Raf/MEK/ERK, since Ras inhibition decreased PI3K activation and PI3K inhibition did not block M‐CSF‐mediated Ras activation. As further support for Ras‐mediated signaling, constitutively active (ca) Ras promoted MEK/ERK activation and osteoclast survival, which was blocked by inhibition of PI3K or Raf. Moreover, PI3K‐selective or Raf‐selective caRas were only partially able to promote osteoclast survival when compared to parental caRas. We then examined whether PI3K and Raf function linearly or in parallel downstream of Ras. Expression of caPI3K increased MEK/ERK activation and promoted osteoclast survival downstream of M‐CSF, supporting this hypothesis. Blocking Raf did not decrease osteoclast survival and MEK/ERK activation promoted by caPI3K. In addition, PI3K‐selective Ras‐mediated survival was not blocked by Raf inhibition. Taken together, our data support that Raf signaling is separate from Ras/PI3K signaling and PI3K signaling is separate from Ras/Raf signaling. These data therefore support a role for Ras in coordinate activation of PI3K and Raf acting in parallel to mediate MEK/ERK‐promoted osteoclast survival induced by M‐CSF. J. Cell. Biochem. 104: 1439–1451, 2008. © 2008 Wiley‐Liss, Inc.
Tribological aspect of lubrication in form tapping of high‐strength steel
Authors: Bierla A. , Fromentin G. , Martin J‐M. , Le Mogne T. , Genet N. 
Published: February 2008

AbstractThis study aims at analysing the tribochemical mechanisms of lubrication during the process of form tapping and consequently optimising the formulation of the lubricant. In order to correlate the tribochemical reactions with the performance of a lubricant, we measure the alteration of the tapping torque according to the American Society for Testing and Materials D5619 standard.The objective of the study also relates to the identification of the additives and the association of their properties to the performance of the lubrication. The goal is to characterise the nature of the tribofilm created at the bottom of the threads, which is the zone that is most severely affected by the working tool. X‐ray photoelectron spectroscopy is used to characterise the surface of formed threads.This study demonstrates a link between the sulphur reactions on the metallic surface and the friction‐reducing performance of the lubricant during form tapping. Copyright © 2008 John Wiley & Sons, Ltd.
Catalytic Synthesis of a Monodisperse Olefin Block Copolymer Using a Living Polymerization System
Authors: Cai Zhengguo , Nakayama Yuushou , Shiono Takeshi 
Published: February 2008

AbstractPolymerization of norbornene has been conducted with [t‐BuNSiMe2(3,6‐t‐Bu2Flu)]TiMe2 (1) in toluene at 20 °C using modified methylaluminoxane that contained 0.4 mol‐% of triisobutylaluminium (TIBA) (dMMAO(0.4)) or 1.8 mol‐% of TIBA (dMMAO(1.8)). The 1‐dMMAO(0.4) catalytic system undergoes a living polymerization of norbornene. The catalysis of norbornene and propylene with the 1‐dMMAO(1.8) catalytic system gives markedly different results because of differences in transfer times of the polymers from Ti to TIBA. The successive addition of norbornene and propylene before the complete consumption of the norbornene in the 1‐dMMAO(1.8) system gives monodisperse PNB‐block‐poly(propylene‐ran‐norbornene)‐block‐PP terminated with a Ti–PP bond, which is exchanged with TIBA. Hence the repeated addition of the same amount of norbornene and propylene realizes the catalytic synthesis of monodisperse block copolymer in this system.magnified image
Biotin α‐End‐Functionalized Gradient Glycopolymers Synthesized by RAFT Copolymerization
Authors: Gody Guillaume , Boullanger Paul , Ladavière Catherine , Charreyre Marie‐Thérèse , Delair Thierry 
Published: February 2008

AbstractBiotinylated gradient glycopolymers have been synthesized via RAFT copolymerization of an acrylamide derivative of galactose with N‐acryloylmorpholine in the presence of a biotin CTA. The polymerization was controlled with a linear increase in molecular weights up to 80% conversion. Copolymer chains have a gradient microstructure with an increasing proportion of galactose units towards the ω chain end. The presence of the biotin ligand at the α end of the chains was confirmed by 1H NMR and MALDI‐ToF MS. This strategy based on the use of a biotin‐CTA instead of a post‐polymerization labelling of the chains resulted in a high percentage of α‐functionalized chains (92–95%). Such α‐end‐functionalized glycopolymer chains may interact with streptavidin‐modified surfaces.magnified image
Light‐Controlled On‐Off Switch of a Fluorescent Nanoparticle
Authors: Furukawa Hidemitsu , Misu Manami , Ando Kazuhiro , Kawaguchi Haruma 
Published: February 2008

AbstractA novel fluorescent nanoparticle with reversible on‐off switching properties has been synthesized. Three different wavelengths of light are used for switching‐on light, switching‐off light and excitation light, respectively. Thus, when this particle is used as a fluorescent probe by irradiation of the excitation light, the on‐off status can be maintained. We also showed that the on‐off status of the fluorescent particle even embedded in hydrogels can be remotely controlled by using two different wavelengths of light. These results promise that this kind of fluorescent particles will introduce a new concept and it will possibly be applied as a novel fluorescent probe, a photo memory, and a switching devise for photonics.magnified image
Supply contracts in manufacturer‐retailer interactions with manufacturer‐quality and retailer effort‐induced demand
Authors: Gurnani Haresh , Erkoc Murat 
Published: February 2008

AbstractWe consider a decentralized distribution channel where demand depends on the manufacturer‐chosen quality of the product and the selling effort chosen by the retailer. The cost of selling effort is private information for the retailer. We consider three different types of supply contracts in this article: price‐only contract where the manufacturer sets a wholesale price; fixed‐fee contract where manufacturer sells at marginal cost but charges a fixed (transfer) fee; and, general franchise contract where manufacturer sets a wholesale price and charges a fixed fee as well. The fixed‐fee and general franchise contracts are referred to as two‐part tariff contracts. For each contract type, we study different contract forms including individual, menu, and pooling contracts. In the analysis of the different types and forms of contracts, we show that the price only contract is dominated by the general franchise menu contract. However, the manufacturer may prefer to offer the fixed‐fee individual contract as compared to the general franchise contract when the retailer's reservation utility and degree of information asymmetry in costs are high. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008
Simulation and implementation of a porous silicon reflector for epitaxial silicon solar cells
Authors: Duerinckx Filip , Kuzma‐Filipek Izabela , Van Nieuwenhuysen Kris , Beaucarne Guy , Poortmans Jef 
Published: February 2008

AbstractOne of the main challenges in the ongoing development of thin film crystalline silicon solar cells on a supporting silicon substrate is the implementation of a long‐wavelength reflector at the interface between the epitaxial layer and the substrate. IMEC has developed such a reflector based on electrochemical anodization of silicon to create a multi‐layer porous silicon stack with alternating high and low porosity layers. This innovation results in a 1–2% absolute increase in efficiency for screenprinted epitaxial cells with a record of 13·8%. To reach a better understanding of the reflector and to aid in its continued optimization, several extensive optical simulations have been performed using an in‐house‐developed optical software programme. This software is written as a Microsoft Excel workbook to make use of its user‐friendliness and modular structure. It can handle up to 15 individual dielectric layers and is used to determine the influence of the number and the sequence of the layers on the internal reflection. A sensitivity analysis is also presented. A study of the angle at which the light strikes the reflector shows separate regions in the physical working of the reflector which include a region where the Bragg effect is dominant as well as a region where total internal reflection plays the largest role. The existence of these regions is proved using reflection measurements. Based on these findings, an estimate is made for the achievable current gain with an ideal reflector and the potential of epitaxial silicon solar cells is determined. Copyright © 2008 John Wiley & Sons, Ltd.
Carbon Nanowalls Growth by Radiofrequency Plasma‐Beam‐Enhanced Chemical Vapor Deposition
Authors: Vizireanu Sorin , Nistor Leona , Haupt Michael , Katzenmaier Verena , Oehr Christian , Dinescu Gheorghe 
Published: February 2008

AbstractWe report the remote growth of carbon nanowalls in a plasma beam sustained by an expanding argon radiofrequency discharge and injected with a small amount of acetylene in the presence of hydrogen as active gas. The growth process was investigated by varying the mass flow rates, ratio and nature of gases (argon, ammonia/hydrogen, and acetylene), the substrate temperature, and the radiofrequency power. Scanning and transmission electron microscopy, Raman spectroscopy, and electron diffraction methods were used for the investigation of the deposited material. We found that although materials with various morphologies can be generally obtained, nanostructured carbon material with a 2D morphology is obtained within a specific range of parameter values.magnified image
Study of TATP: Spontaneous Transformation of TATP to DADP
Authors: Matyas Robert , Pachman Jiri , Ang How‐Ghee 
Published: February 2008

AbstractTATP, prepared in the presence of catalysts methanesulfonic, perchloric, or sulfuric acid, has been found to undergo transformation to DADP. However, no transformation occurs if TATP is purified or prepared involving catalysts such as hydrochloric acid, tin(IV) chloride, and nitric acid. The transformation has been monitored by the methods of DTA and HPLC.
Induced fit in liver X receptor beta: A molecular dynamics‐based investigation
Authors: Beautrait Alexandre , Karaboga Arnaud S. , Souchet Michel , Maigret Bernard 
Published: February 2008

AbstractLigand induced fit phenomenon occurring at the ligand binding domain of the liver X receptor beta (LXRβ) was investigated by means of molecular dynamics. Reliability of a 4‐ns trajectory was tested from two distinct LXRβ crystal complexes 1PQ6B/GW and 1PQ9B/T09 characterized by an open and a closed state of the pocket, respectively. Crossed complexes 1PQ6B/T09 and 1PQ9B/GW were then submitted to the same molecular dynamic conditions, which were able to recover LXRβ conformations similar to the original crystallography data. Analysis of “open to closed” and “closed to open” conformational transitions pointed out the dynamic role of critical residues lining the ligand binding pocket involved in the local remodeling upon ligand binding (e.g., Phe271, Phe329, Phe340, Arg319, Glu281). Altogether, the present study indicates that the molecular dynamic protocol is a consistent approach for managing LXRβ‐related induced fit process. This protocol could therefore be used for refining ligand docking solutions of a structure‐based design strategy. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Correlated mutations at gp120 positions 322 and 440: Implications for gp120 structure
Authors: Rosen Osnat , Samson Avraham O. , Anglister Jacob 
Published: February 2008

AbstractAnalysis of V3 and C4 sequences of HIV‐1 reveals correlated mutations at gp120 positions 322 and 440, and a very strong preference for a positively charged residue at position 440 when position 322 is negatively charged. This observation suggests that these two residues are close to each other and interact electrostatically in R5 viruses. This interaction was used to model V3 in the context of gp120 using NMR data for the V3 loop and the crystal structure of the gp120‐core. The interaction between residues 322 and 440 may serve as part of the molecular switch for HIV‐1 phenotype conversion. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Compact dimension of denatured states of staphylococcal nuclease
Authors: Chow C.‐Y. , Wu Ming‐Chya , Fang Huey‐Jen , Hu Chin‐Kun , Chen Hueih‐Min , Tsong Tian‐Yow 
Published: February 2008

AbstractFluorescence and circular dichroism stopped‐flow have been widely used to determine the kinetics of protein folding including folding rates and possible folding pathways. Yet, these measurements are not able to provide spatial information of protein folding/unfolding. Especially, conformations of denatured states cannot be elaborated in detail. In this study, we apply the method of fluorescence energy transfer with a stopped‐flow technique to study global structural changes of the staphylococcal nuclease (SNase) mutant K45C, where lysine 45 is replaced by cysteine, during folding and unfolding. By labeling the thiol group of cysteine with TNB (5,5′‐dithiobis‐2‐nitrobenzoic acid) as an energy acceptor and the tryptophan at position 140 as a donor, distance changes between the acceptor and the donor during folding and unfolding are measured from the efficiency of energy transfer. Results indicate that the denatured states of SNase are highly compact regardless of how the denatured states (pH‐induced or GdmCl‐induced) are induced. The range of distance changes between two probes is between 25.6 and 25.4 Å while it is 20.4 Å for the native state. Furthermore, the folding process consists of three kinetic phases while the unfolding process is a single phase. These observations agree with our previous sequential model: N0 ⇆ D1 ⇆ D2 ⇆ D3 (Chen et al., J Mol Biol 1991;220:771–778). The efficiency of protein folding may be attributed to initiating the folding process from these compact denatured structures. Proteins 2008. © 2008 Wiley‐Liss, Inc.
QED theory for excitons with microscopic nonlocality
Authors: Bamba Motoaki , Ishihara Hajime 
Published: February 2008

AbstractWe have constructed QED theory for excitons with microscopic nonlocality or nonlocal susceptibility originating from their center‐of‐mass motion. The nonlocality must be properly considered in excitons' weak (center‐of‐mass) confinement regime where the long wavelength approximation is breakdown. This theory keeps good correspondences with its underlying theories, the QED theory for dispersive and absorptive local dielectrics and the microscopic nonlocal theory developed in the semiclassical framework. Our theory provides correlation functions of excitons, which renormalize radiative shift, transition between exciton states via electromagnetic fields, radiative and nonradiative relaxation processes. By using these functions, we can systematically study various nonlinear, dephasing, and emission processes of excitons in weak‐confinement to bulk‐like systems
Purcell effect in micropillars with oxidized Bragg mirrors
Authors: Cavigli L. , Lunghi L. , Abbarchi M. , Vinattieri A. , Alloing B. , Zinoni C. , Fiore A. , Gerardino A. , Frigeri P. , Seravalli L. , Franchi S. , Gurioli M. 
Published: February 2008

AbstractHere we report the growth and the characterization of pillar microcavities, constituted by Bragg mirrors, which are composed by alternate layers of GaAs and aluminum oxide. The selective oxidation of the AlAs layers allowed to increase the refraction index mismatch between the GaAs and AlAs. As a consequence we obtained high reflectivity Bragg mirrors even with only three layers, a factor three less than usually necessary in the more common GaAs/AlAs Bragg reflectors.This not only simplifies the growth process, but also gives a reduction of the cavity mode volume. We have examined several MESAs with pillar diameter ranging from 1 to 10 mm, containing a system of InAs quantum dots. The quality factors of the cavities range from Q = 600–2000. Enhancement of the spontaneous emission rate of QDs was observed when the emission is on resonance with cavity modes. Purcell factors up to 2 were measured. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Resonant nonlinear studies of trapped 0D‐microcavity polaritons
Authors: Nardin Gaël , Daïf Ounsi El , Paraïso Taofiq K. , Baas Augustin , Richard Maxime , Morier‐Genoud Francois , Deveaud Benoit 
Published: February 2008

AbstractWe performed studies on microcavity polaritons trapped along the three dimensions of space, under resonant excitation on a confined lower polariton state.We observed various nonlinear behaviors as a function of the pump power, without any apparent loss of the strong‐coupling. That may be understood as effects of Coulomb interaction. Indications of bistable behaviors in the system are observed and discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton‐polaritonic effects in the optical absorption by regular and disordered arrays of quantum wells
Authors: Kosobukin V. A. , Poddubny A. N. 
Published: February 2008

AbstractExciton‐polaritonic transfer and absorption are theoretically studied in short‐period, Bragg‐type and disordered quantum‐well (QW) arrays. In all cases, the integral absorptivity is shown to increase monotonously with the nonradiative decay rate of quasi‐2D excitons and the number of QWs. The scale and growth rate of integral absorptivity depend essentially on the above type of multiple‐QW structure under consideration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibrational polaritons in thin oxide and nitride films
Authors: Yakovlev V. A. , Vinogradov E. A. , Novikova N. N. , Mattei G. , Godinho V. , Fernández‐Ramos C. , Fernández A. , Delplancke‐Ogletree M. P. 
Published: February 2008

AbstractAngular dependencies of infrared reflectivity spectra of thin silicon oxinitride amorphous films on silicon and porous aluminum oxide films on aluminum had been measured. These spectra show vibrational bands and strong interference bands allowing film thickness and dielectric function calculation and providing useful information on the bonding structure of the coatings. Angular dependencies of these bands give the dispersion of vibrational and interference polariton modes in the films. The intersection of vibrational and interference polaritons has been observed for silicon oxinitride film. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carrier dynamics of straininduced quantum dots and THz radiation‐induced exciton cooling
Authors: Boxberg Fredrik , Tulkki Jukka 
Published: February 2008

AbstractWe have modeled strain‐induced quantum dots and analyzed previous anomalous experimental observations of a cooling of radiative quantum dot (QD) excitons by THz radiation. We have made three‐dimensional (3D) modeling of the elastic strain and piezoelectric fields. The 3D electronic structure was simulated using multiband envelope function techniques and used as a basis for Monte‐Carlo simulations of the carrier dynamics.We have found that the THz radiation‐induced QD exciton cooling is due to an electron‐hole separation and a related THz radiation excitation of holes within the quantum dot. This phenomenon is maintained by an effective relaxation of holes into states which are well separated from the confined electrons. The relaxation of holes is attributed to acoustic phonon emission and, at high carrier densities, to Auger processes. The electron and hole populations of the quantum dot tend towards a highly polarized state that cannot be broken without external excitations of the holes (by e.g. THz radiation or a thermal bath). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hierarchical spatial hashing‐based collision detection and hybrid collision response in a haptic surgery simulator
Authors: Li X. , Gu L. , Zhang S. , Zhang J. , Zheng G. , Huang P. , Xu J. 
Published: February 2008

AbstractBackgroundCollision detection and response are two crucial aspects in a virtual surgery simulator, which significantly affect the output in real‐time response and simulation realism.MethodsWe propose a collision detection algorithm which employs a novel hierarchical spatial hashing to effectively achieve appropriate parameters. Thereafter we present a hybrid collision response scheme which takes the advantages of three traditional methods and introduces a ‘force filter’ to obtain more realistic feedback force.ResultsThe average performance of our proposed collision detection has been improved by 15.65% against the traditional method. After collision response processing the smoothness of feedback force has been greatly enhanced, and this indicates a more realistic feedback force without restricting the range of force inputs.ConclusionsThe experimental results reveal that the proposed approaches can achieve the real‐time response and simulation realism required by a haptic surgery simulator. Copyright © 2008 John Wiley & Sons, Ltd.