bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon nanotubes as electron sources
Authors: Milne W. I. , Teo K. B. K. , Mann M. , Bu I. Y. Y. , Amaratunga G. A. J. , De Jonge N. , Allioux M. , Oostveen J. T. , Legagneux P. , Minoux E. , Gangloff L. , Hudanski L. , Schnell J.‐P. , Dieumegard L. D. , Peauger F. , Wells T. , El‐Gomati M. 
Published: April 2006

AbstractCarbon nanotubes (CNTs) are a unique form of carbon filament/fiber in which the graphene walls roll up to form tubes. They can exhibit either metallic‐like or semiconductor‐like properties. With the graphene walls parallel to the filament axis, nanotubes (single wall metallic‐type or multi‐wall) exhibit high electrical conductivity at room temperature. This high electrical conductivity allied to their remarkable thermal stability has made CNTs one of the most intensely studied material systems for field emission (FE) applications. In this paper we will describe the growth of multiwall CNTs and their application in a range of field emission based systems including their use in SEM sources, emitters for use in microwave amplifiers and as emitters in field emission based displays (FEDs). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Buckling in boron sheets and nanotubes
Authors: Cabria Iván , Alonso Julio A. , López María J. 
Published: April 2006

AbstractDensity functional calculations have been carried out to obtain the geometric and electronic structure of boron sheets and nanotubes. The buckled boron sheet formed by alternating up and down rows of B atoms, with a buckling height of 0.85 Å, is about 0.20 eV/B atom more stable than the corresponding atomically flat sheet. Two different B–B bond‐lengths characterize the buckled geometry: (i) 1.63 Å between the B atoms in a row and (ii) 1.81 Å between the B atoms in adjacent rows. Boron nanotubes (BNTs) formed by rolling up a B sheet exhibit also a buckled surface when their helicity allows for the formation of alternating up and down B rows in the surface. In all other cases, BNTs exhibit only flat surfaces. Hence, all the (n , 0) BNTs have a buckled geometry, while not all the (n , n ) BNTs have the same geometry. The buckled and flat nanostructures have different geometric and bonding characteristics, but both are metallic. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
European research on emerging nanoelectronic information processing components
Authors: Van Hove P. 
Published: April 2006

AbstractThis contribution highlights advanced research challenges and opportunities in the area of devices and components responding to projected information processing requirements in a 10–20 year time frame. While CMOS technology is expected to be the major information technology vehicle in this time frame, the possibility of a transition to a complementary technology within 10–15 years opens up opportunities and requirements for research in new phenomena, new structures, new materials and new implementations of information processing components. In the presence of growing worldwide awareness of these needs, early European efforts in nanoelectronics should be pursued and well targeted. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Equiatomic FePt nanoparticles synthesized via pyrolysis of iron(III) ethoxide and platinum(II) acetylacetonate
Authors: Saita S. , Maenosono S. 
Published: April 2006

AbstractFePt nanoparticles (NPs) of 4.5 nm mean diameter were synthesized using iron(III) ethoxide and platinum(II) acetylacetonate as precursors. The reaction proceeded without any reducing agent, providing a facile way of synthesis of FePt NPs. FePt NPs were characterized by transmission electron microscopy (TEM), energy‐dispersive X‐ray fluorescence spectrometry (EDX), and inductively coupled plasma atomic emission spectrometry (ICP‐AES). The average composition of NPs was found to be equiatomic and the composition distribution of each NP was considerably narrow. The spatio‐temporal homogeneity and thermal decomposition mode of iron source are considered to be the reason for the improvement of composition distribution. Phase transfer of FePt NPs from oil phase to water phase was also investigated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Waferscale assembly of Field‐Aligned nanotube Networks (FANs)
Authors: Dimaki Maria , Bøggild Peter 
Published: April 2006

AbstractWe demonstrate the integration of nanotube networks on 512 individual devices on a full 4‐inch wafer in less than 60 seconds with a roughly 80% yield using dielectrophoresis. We present here investigations of the morphology and electrical resistance of such field aligned networks for different frequencies of the electrical field used to attract the nanotubes to the electrodes. Preliminary data of response to visible light irradiation as well as changes in the humidity indicate that the field aligned networks could be used as sensor components that may well integrate with CMOS due to mild assembly conditions. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rf glow discharge optical emission spectrometry for the analysis of arrays of Ni nanowires in nanoporous alumina and titania membranes
Authors: Prida V. M. , Navas D. , Pirota K. R. , Hernandez‐Velez M. , Menéndez A. , Bordel N. , Pereiro R. , Sanz‐Medel A. , Hernando B. , Vazquez M. 
Published: April 2006

AbstractAnodic alumina (Al2O3) and titania (TiO2) nanoporous oxide membranes are among the most widely studied self‐organized nanopore templates, formed by uniform and well aligned arrays of synthetized nanometric pores or tubes. Here, we perform a comparative study of the depth profiling analysis in self‐ordered alumina and titania nanoporous membrane templates by means of the radiofrequency glow discharge coupled to optical emission spectrometry (rf‐GD‐OES) technique. The densely packed columnar arrays of hexagonally self‐ordered nanoporous alumina membranes investigated, with an average inner pore diameter of 35 nm and 105 nm interspacing, give an uniform thickness pore length about more than 5 µm, depending on the anodization time. Meanwhile, the analysis of the anodized titania nanotubes, with an average inner pore diameter of 100 nm and 40 nm wall thickness, shown to be about 300 nm in length. Each type of membranes were also studied in both cases, when the nanopores were empty and after filling with electrodeposited Ni. The direct analysis by rf‐GD‐OES reveals the ability of this technique to control the quality of these so synthesized nanocomposites formed by electrodeposited Ni nanowires into the alumina and titania nanoporous templates. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characterization of Sn doped ZnO thin films by pulsed laser deposition
Authors: López‐Ponce E. , Costa‐Krämer J. L. , Martín‐González M. S. , Briones F. , Fernández J. F. , Caballero A. C. , Villegas M. , de Frutos J. 
Published: April 2006

AbstractSn:ZnO thin films with different Sn concentrations were grown by pulsed laser deposition (PLD) onto single‐crystal Si(001) substrates at an oxygen pressure of 2 × 10–2 mbar and substrate temperature of 600 °C. The targets used were high density Sn:ZnO pellets with different Sn concentrations produced by mixing ZnO and SnO2 by conventional ceramic routes. A deep structural and electrical characterization was carried out in order to determine the role of an increasing Sn nominal concentration on the ZnO film transport properties. Only films with a nominal 0.1 at% Sn show an improvement of the transport properties, lower resistivity and higher donor concentration, with respect to pure ZnO thin films. For films with larger Sn nominal concentrations segregated SnZnO phases appear that lead to larger film resistivities and no increase in donor concentration. The 0.1 at% Sn film is accordingly a good candidate to study the possible room temperature ferromagnetism when co doping with Mn. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and perspectives of complex crystalline nano‐structures
Authors: Kudera Stefan , Carbone Luigi , Zanella Marco , Cingolani Roberto , Parak Wolfgang J. , Manna Liberato 
Published: April 2006

AbstractResearch on inorganic colloidal nanocrystals has moved from the synthesis of simple structures, such as spherical nanoparticles, to more elaborate particles with shapes such as rods, stars, discs, and branched nanocrystals, and recently to nanoparticles that are composed out of sections of different materials. Nanocrystal heterostructures represent a convenient approach to the development of nanoscale building blocks, as they merge sections with different functionality in the same particle, without the need of inorganic cross‐linkers. The present article gives an overview of synthesis strategies to complex nanocrystals and will highlight their structural properties, as well as discuss some envisaged applications. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carbon nanotube based composites for electronic applications: CNT–conducting polymers, CNT–Cu
Authors: Ferrer‐Anglada N. , Gomis V. , El‐Hachemi Z. , Weglikovska U. Dettlaff , Kaempgen M. , Roth S. 
Published: April 2006

AbstractWe performed two different types of composites using single wall carbon nanotubes: 1) transparent electrodes, using a thin network of carbon nanotubes as electrode on which we can grow a conducting polymer electrochemically on it, polyaniline or polypirrole, CNT–CP; the obtained thin films are both transparent (transmission coefficient T from 70% to 95%) and electrically conducting. The samples were observed by AFM, optical and Raman spectroscopy, room temperature electrical conductivity were performed. 2) CNT with a metal, copper in our case (CNT–Cu), as a material with high electrical and thermal conductivity and low coefficient of thermal expansion (CTE), to be used in electronic packaging. We observed the samples by AFM and SEM. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Free‐electron spin surfaces in 3D and 2D zinc‐blende semiconductors
Authors: Dargys A. 
Published: April 2006

AbstractUsing the Dresselhaus Hamiltonian and parametrized form of the wave functions it is shown that 2D electron spin surfaces are the ellipsoids of rotation in zinc‐blende‐type semiconductors, when the spin‐splitting is included. However, in bulk semiconductors the exact solution shows that the spin surfaces are of higher, spherical symmetry. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The stability of two-phase flow over a swept wing
Authors: Coward Adrian V. , Hall Philip 
Published: April 2006

We use numerical and asymptotic techniques to study the stability of a two-phase air/water flow above a flat porous plate. This flow is a model of the boundary layer which forms on a yawed cylinder and can be used as a useful approximation to the air flow over swept wings. The air and water form an immiscible interface which can destabilize the flow, leading to travelling wave disturbances which move along the attachment line. This instability occurs for lower Reynolds numbers than is the case in the absence of a water layer. The two-fluid flow can be used as a crude model of the effect of heavy rain on the leading edge of a swept wing.We also investigate the instability of inviscid stationary modes. We calculate the effective wavenumber and orientation of the stationary disturbance when the fluids have identical physical properties. Using perturbation methods we obtain corrections due to a small stratification in viscosity, thus quantifying the interfacial effects. Our analytical results are in agreement with the numerical solution which we obtain for arbitrary fluid properties.
Cellular cholesterol controls TRPC3 function: evidence from a novel dominant-negative knockdown strategy
Authors: Graziani Annarita , Rosker Christian , Kohlwein Sepp D. , Zhu Michael X. , Romanin Christoph , Sattler Wolfgang , Groschner Klaus , Poteser Michael 
Published: April 2006

TRPC3 (canonical transient receptor potential protein 3) has been suggested to be a component of cation channel complexes that are targeted to cholesterol-rich lipid membrane microdomains. In the present study, we investigated the potential role of membrane cholesterol as a regulator of cellular TRPC3 conductances. Functional experiments demonstrated that cholesterol loading activates a non-selective cation conductance and a Ca2+ entry pathway in TRPC3-overexpressing cells but not in wild-type HEK-293 (human embryonic kidney 293) cells. The cholesterol-induced membrane conductance exhibited a current-to-voltage relationship similar to that observed upon PLC (phospholipase C)-dependent activation of TRPC3 channels. Nonetheless, the cholesterol-activated conductance lacked negative modulation by extracellular Ca2+, a typical feature of agonist-activated TRPC3 currents. Involvement of TRPC3 in the cholesterol-dependent membrane conductance was further corroborated by a novel dominant-negative strategy for selective blockade of TRPC3 channel activity. Expression of a TRPC3 mutant, which contained a haemagglutinin epitope tag in the second extracellular loop, conferred antibody sensitivity to both the classical PLC-activated as well as the cholesterol-activated conductance in TRPC3-expressing cells. Moreover, cholesterol loading as well as PLC stimulation was found to increase surface expression of TRPC3. Promotion of TRPC3 membrane expression by cholesterol was persistent over 30 min, while PLC-mediated enhancement of plasma membrane expression of TRPC3 was transient in nature. We suggest the cholesterol content of the plasma membrane as a determinant of cellular TRPC3 activity and provide evidence for cholesterol dependence of TRPC3 surface expression.
Characterization of yeast pyruvate kinase 1 as a protein kinase A substrate, and specificity of the phosphorylation site sequence in the whole protein
Authors: Portela Paula , Moreno Silvia , Rossi Silvia 
Published: April 2006

Pyk1 (pyruvate kinase 1) from Saccharomyces cerevisiae was characterized as a substrate for PKA (protein kinase A) from bovine heart and yeast. By designing Pyk1 synthetic peptides containing potential PKA sequence targets (Ser22, Thr94 and Thr478) we determined that the peptide S22 was a substrate for PKA in vitro, with a Ksp* (specificity constant) 10-fold and 3-fold higher than Kemptide for bovine heart and yeast PKA respectively. In vitro phosphorylation of the Pyk1 S22A mutant protein was decreased by as much as 90% when compared with wild-type Pyk1 and the Pyk1 T94A mutant. The Ksp* values for Pyk1 and Pyk1 T94A were the same, indicating that both proteins are phosphorylated at the same site by PKA. Two-dimensional PAGE of Pyk1 and Pyk1 S22A indicates that in vivo the S22A mutation prevented the formation of one of the Pyk1 isoforms. We conclude that in yeast the major PKA phosphorylation site of Pyk1 is Ser22.
Phosphorylation of Ser22 leads to a Pyk1 enzyme that is more active in the absence of FBP (fructose 1,6-bisphosphate). The specificity of yeast and mammalian PKA towards the S22 peptide and towards whole Pyk1 protein was measured and compared. The Ksp* for the S22 peptide is higher than that for Pyk1, indicating that the peptide modelled on Pyk1 is a much better substrate than Pyk1, regardless of which tissue was used as the source of PKA. However, the Km of Pyk1 protein is lower than that of the better substrate, the S22 peptide, indicating that ground-state substrate binding is not the major determinant of substrate specificity for PKA.
Evolutionary trace report_maker: a new type of service for comparative analysis of proteins
Authors: Mihalek I. , Reš I. , Lichtarge O. 
Published: April 2006

Abstract
Summary: Evolutionary trace report_maker offers a new type of service for researchers investigating the function of novel proteins. It pools, from different sources, information about protein sequence, structure and elementary annotation, and to that background superimposes inference about the evolutionary behavior of individual residues, using real-valued evolutionary trace method. As its only input it takes a Protein Data Bank identifier or UniProt accession number, and returns a human-readable document in PDF format, supplemented by the original data needed to reproduce the results quoted in the report.
Availability: Evolutionary trace reports are freely available for academic users at
Contact: {imihalek,ires,lichtarge}@bcm.tmc.edu
Genome‐Wide Profiling of Oral Squamous Cell Carcinoma by Array‐Based Comparative Genomic Hybridization
Authors: Sparano Anthony , Quesnelle Kelly M. , Kumar Madhu S. , Wang Yan , Sylvester Albert J. , Feldman Michael , Sewell Duane A. , Weinstein Gregory S. , Brose Marcia S. 
Published: April 2006

AbstractObjectives: Array‐based comparative genomic hybridization (aCGH) was used to develop a genome‐wide molecular profile of oral squamous cell carcinoma (OSCC). Copy number alterations (CNAs) were identified by chromosomal region, mapped to specific genes, and compared with several previously documented CNAs associated with head and neck squamous cell carcinoma (HNSCC). The status of 512 commonly altered cancer genes was assessed and evaluated as potential correlates of tumor behavior.Methods: Tumor tissue DNA was isolated for aCGH from 21 prospectively collected fresh–frozen OSCC specimens. aCGH was performed at 0.9‐Mb resolution to identify distinct regions of genomic alteration and their associated genes. Cancer genes commonly altered were then correlated with clinicopathologic tumor data.Results: Genomic regions most frequently amplified (>35%) were located on 3q, 5p, 8q, 9q, and 20q, although regions most frequently deleted (>40%) involved chromosomes 3p, 8p, 13q, and 18q. Minimal regions of CNA identified, by aCGH narrowed larger, previously documented CNAs associated with HNSCC to significantly smaller regions, yielding shorter lists of candidate genes. Cancer‐related genes altered in greater than 25% OSCC samples were identified (22 amplified, 17 deleted). Several genes associated with the Fanconi anemia DNA‐damage response pathway were frequently altered, including BRCA1, BRCA2, FANCD2, and FANCG. Other cancer‐related genes linked to hereditary cancer syndromes include VHL, MLH1, XPC, and RB1.Conclusions: Genome‐wide aCGH can be used to detect and map CNAs in OSCC tissue specimens with high resolution. These data implicate several candidate genes and gene pathways in the tumorigenesis of sporadic OSCC.
Direct Measurement of Subglottic Air Pressure While Swallowing
Authors: Gross Roxann Diez , Steinhauer Kimberly M. , Zajac David J. , Weissler Mark C. 
Published: April 2006

AbstractObjective: The subglottic pressure theory for swallowing asserts that laryngeal mechanoreceptors have a role in the regulation of swallowing function. The primary purpose of this study was to determine if subglottic air pressure is generated during swallowing in a healthy, nontracheostomized person.Methods: This pilot investigation used a prospective, repeated‐measures design in a single subject. Direct measurement of subglottic air pressure was obtained through percutaneous puncture of the cricothyroid membrane. Swallows were timed with four randomly assigned lung volumes: total lung capacity, tidal volume, functional residual capacity (FRC), and residual volume.Results: Lung volumes above FRC generated positive subglottic pressure during the swallow, whereas lung volumes below FRC generated consistently negative subglottic pressures. The degree and polarity of the pressure was directly related to lung volume at the time of the swallow.Conclusion: These findings illustrate that during normal swallowing, positive subglottic air pressure is likely present. Previously, subglottic air pressure during swallowing had been measured in tracheostomy patients only.
Molecular Basis of Posttransplant Squamous Cell Carcinoma: The Potential Role of Cyclosporine A in Carcinogenesis
Authors: Tiu Jeremy , Li Hongli , Rassekh Christopher , van der Sloot Paul , Kovach Rodney , Zhang Peilin 
Published: April 2006

AbstractCyclosporine (CSA) is a widely used immunosuppressive agent, predominantly for transplant patients. It is well recognized that transplant patients are prone to develop squamous carcinoma of the skin and mucosa, and this high incidence of squamous carcinoma in the transplant population cannot be explained by immunosuppression alone. We hypothesize that CSA may play a significant role in the transformation of normal epidermal squamous cells to carcinoma. CSA is a specific ligand for calcineurin, a ubiquitously expressed cellular serine/threonine phosphatase, that plays important roles in the immune system and cardiac muscles. Using global gene‐profiling methods, we studied the short‐time CSA effect on the squamous cell line (SCC‐015) using Affymetrix human gene chips (Human U133, 2.0 plus chip). Multiple groups of genes were identified to be responsive to CSA treatment, including many genes of unknown functions. We then used reverse transcriptase–polymerase chain reaction and immunoblot analyses to selectively confirm the results from the chips analyses with emphasis on the regulatory molecules important for cellular functions of apoptosis, DNA damage repair, and cellular transformation. This global gene‐profiling study indicated that CSA not only functions as an immunosuppressant on the immune system, but also activates/inhibits a wide array of genes important for cell‐cycle regulation, apoptosis, and oncogene/tumor‐suppressor activation. These functions of CSA on skin and mucosa systems at the molecular level are likely important in the pathogenesis of squamous carcinoma in transplant patients.
Squamous Cell Carcinoma of the Sinonasal Cavity Arising as a Second Primary in Individuals with Head and Neck Cancer
Authors: Wolpoe Matthew E. , Goldenberg David , Koch Wayne M. 
Published: April 2006

AbstractObjectives/Hypothesis: Second primary tumors occur frequently in patients with head and neck carcinoma. This may be caused by generalized exposure to carcinogens resulting in “field cancerization” or to the individuals' generalized susceptibility to cancer. The paranasal sinuses are not commonly included in the sites considered at risk for this process. We therefore sought to assess the overall risk of contracting a primary cancer in this region after having a tumor elsewhere in the upper aerodigestive tract.Study Design: Retrospective.Methods: Two thousand four hundred seventy‐five patients with squamous cell carcinoma of the upper aerodigestive tract were analyzed using a tumor registry at a tertiary care institution.Results: Five (0.2%) patients were identified as having a second primary in the sinonasal tract. The average interval between the index and second primary tumors was 28.4 (range 8–60) months. All five patients presented with symptoms typical of sinus inflammatory disease and had advanced sinus lesions at the time of diagnosis. These findings are typical of those with sinonasal carcinoma in that they present with nonspecific signs and symptoms and were diagnosed with locally advanced disease despite being in a surveillance program for their index cancer.Conclusions: Although uncommon, the data reported here support inclusion of the sinonasal tract in these surveillance programs. This could result in earlier detection and greater opportunity for curative intervention.