bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen diffusion in titanium‐hydride observed by the diffraction‐enhanced X‐ray imaging method
Authors: Mizuno K. , Furuya Y. , Hirano K. , Okamoto H.
Published: July 2007

The X‐ray refraction imaging technique was applied to the quantitative study of hydrogen diffusion in titanium‐hydride. Diffusivity and activation energy of hydrogen diffusion were determined by direct observation of the hydride. The hydride was formed on the surface of titanium by electrolytic‐charging at 31, 63 and 98 °C. The specimens were cut into 1 mm thick slices for cross‐sectional observations. The hydride layer was observed using the diffraction‐enhanced X‐ray imaging (DEI) method. Boundaries between titanium and the hydride were observed as thick black or white lines parallel to the specimen surface in the DEI images similar to previously reported results. Hydride distribution caused by hydrogen diffusion from the surface was calculated using an assumed hydrogen diffusivity value and from the solution of the appropriate diffusion equation. The results were converted to the intensity profiles of refraction images of the hydride using the measured rocking curve from an analyzer. The calculated intensity profiles were compared to those obtained from the experimental results and the fitted diffusivity was determined by trial and error. The activation energy of hydrogen in titanium‐hydride thus obtained, 0.55 ± 0.07 eV, showed good agreement with the widely accepted value obtained by the internal friction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of InP porous layer by high‐resolution X‐ray diffraction
Authors: Punegov V. I. , Lomov A. A. , Shcherbachev K. D.
Published: July 2007

A high resolution X‐ray diffraction method has been effectively used for the structural characterization of InP porous layers. It was revealed that strong diffuse scattering from pores around reciprocal lattice points does depend on the azimuth positions of samples. To extract structural information about porous layers fabricated under different conditions theoretical analysis of the measured reciprocal space maps (RSM) was performed. The statistical dynamical X‐ray diffraction theory was used to describe coherent and diffuse scattering from a layer with cylindrical pores. A numerical analysis of the RSMs for two azimuth positions φ (φ = 0 and φ = 90°) and detailed sections of RSMs (linescans) allowed determination of the radius, the length of the pores and tilting angle with respect to the surface normal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A sensitive method for detecting long‐range strain in nearly perfect crystals using X‐ray dynamical diffraction
Authors: Saka Takashi
Published: July 2007

A very sensitive method is proposed for the detection of long‐range strain in otherwise perfect crystalline materials. In this method, the specimen is rotated around the scattering vector in the symmetrical Laue case. Long‐range strains due to a uniform bending or torsion, that are not detectable with the symmetrical Laue condition, are sensitively detected by the proposed method of rotating the specimen. Several demonstrative topographic observations are presented. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radiation‐induced structural transformations in a silicon layer of SOI
Authors: Shcherbachev K. D. , Bublik V. T. , Mordkovich V. N. , Pazhin D. M. , Alves E. , Barradas N. P.
Published: July 2007

The differences in the secondary processes proceeding in the silicon layer of SOI and reference bulk silicon wafers are revealed by using High‐Resolution X‐ray diffraction and Rutherford Backscattering spectroscopy methods. The damage depth profiles in the implanted layers described by both strain and static Debye–Waller factor profiles, were reconstructed from the diffraction patterns using an autofitting procedure, based on a genetic algorithm. The contribution of diffuse scattering was excluded using the triple‐crystal diffractometry technique. The defect density profiles were obtained from the RBS/Channelling measurements, which were carried out using 4He+ beam at 2.0 MeV. The DICADA code, based on the theoretical description of dechanneling was used to interpret the RBS/C data. Accumulation kinetics, spatial distribution, and concentration of radiation‐induced defects in the topmost silicon layer of SOI and a bulk silicon were shown to be essentially different. The influence of the fields was shown to lead to the loss of crystallinity of the thin surface layer of silicon in SOI due to accumulation of vacancy‐type defects and increase of concentration of interstitial atoms near the internal interphase boundary “Si–SiO2”. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined double‐ and triple‐crystal X‐ray diffractometry with account for real defect structures in all crystals of X‐ray optical schemes
Authors: Shpak A. P. , Molodkin V. B. , Olikhovskii S. I. , Kyslovskyy Ye. M. , Reshetnyk O. V. , Vladimirova T. P. , Len E. G. , Nizkova A. I. , Venger V. M. , Dmitriev S. V.
Published: July 2007

Analytical expressions for coherent and diffuse scattering intensities with account for imperfections in all the crystals of double‐ and triple‐crystal diffractometers (DCD and TCD) have been derived from the generalized dynamical theory of X‐ray scattering in real single crystals which contain microdefects of various types. The analysis of TCD and DCD profiles measured from Czochralski‐grown silicon single crystal with oxygen precipitates and dislocation loops has been carried out. Characteristics of defect structures in sample and monochromator have been determined by using the combined DCD+TCD method. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Focusing high energy X‐rays with stacked Fresnel zone plates
Authors: Snigireva I. , Snigirev A. , Kohn V. , Yunkin V. , Grigoriev M. , Kuznetsov S. , Vaughan G. , Di Michiel M.
Published: July 2007

Stacking technique was developed in order to increase focusing efficiency of Fresnel zone plates at high energies. Two identical Si chips each of which containing Fresnel zone plates were used for stacking. Alignment of the chips was achieved by on‐line observation of the moiré pattern from the two zone plates. The formation of moiré patterns was studied theoretically and experimentally at different experimental conditions. To provide the desired stability Si‐chips with zone plates were bonded together with slow solidification speed epoxy glue. Technique of angular alignment in order to compensate a linear displacement in the process of gluing was proposed. Two sets of stacked FZPs were produced and experimentally tested to focus 15 and 50 keV X‐rays. Gain in the efficiency by factor 2.5 was demonstrated at 15 keV. Focal spot of 1.8 μm vertically and 14 μm horizontally with 35% efficiency was measured at 50 keV. Forecast for the stacking of nanofocusing Fresnel zone plates was discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Three‐dimensional topography using an X‐ray microbeam and novel slit technique
Authors: Tanuma R. , Kubo T. , Togoh F. , Tawara T. , Saito A. , Fukuda K. , Hayashi K. , Tsusaka Y.
Published: July 2007

This paper describes section topography using an X‐ray microbeam and a novel slit having a V‐shaped crevice (V‐slit). The V‐slit is characterized by a sharp‐pointed exponential transmission curve, which enables depth‐resolved imaging with high spatial resolution. An iterative deconvolution for image restoration is effectively executable, providing submicron resolution in cross‐sectional diffraction imaging. The new method is applied to the analysis of screw dislocation in a SiC diode. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray characterization of periodic sub‐nm surface relief gratings
Authors: Zaumseil P. , Birkholz M. , Weidner G.
Published: July 2007

Line and cross lattices of 260 and 360 nm pitch were prepared by covering p‐doped Si(100) substrates with photoresist, structuring and implanting with 3 × 1015 cm–2, 45 keV As+ ions. These doping lattices with n+–p periodicity were investigated by X‐ray diffraction (XRD) and reflectivity (XRR). While XRD did not show any signal of the periodic structure, XRR revealed a clear periodic diffraction pattern related to the pitch of the doping lattice. The features of this pattern as a function of the lattice orientation are discussed in detail for the cross lattice. Atomic force microscopy showed that the measured diffraction pattern is caused by a surface relief grating with sub‐nm amplitude, which was generated by a final doping‐dependent etching step during sample preparation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray diffraction spot mapping – a tool to study structural properties of semiconductor disk laser devices
Authors: Zeimer U. , Grenzer J. , Korn D. , Döring S. , Zorn M. , Pittroff W. , Pietsch U. , Saas F. , Weyers M.
Published: July 2007

Local lattice plane curvature of semiconductor disk laser devices is determined by an X‐ray spot mapping technique using white beam synchrotron radiation. This method allows for in‐situ studies of the dependence of the lattice plane profile on device temperature and local heating by optical pumping. The influence of different device mounting procedures on the structural and optical device parameters was investigated. This knowledge was used for device technology optimisation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synchrotron‐radiation computed laminography for high‐resolution three‐dimensional imaging of flat devices
Authors: Helfen Lukas , Myagotin Anton , Rack Alexander , Pernot Petra , Mikulík Petr , Di Michiel Marco , Baumbach Tilo
Published: July 2007

Synchrotron‐radiation computed laminography (SRCL) is developed as a method for high‐resolution three‐dimensional (3D) imaging of regions of interest (ROIs) in all kinds of laterally extended devices. One of the application targets is the 3D X‐ray inspection of microsystems. In comparison to computed tomography (CT), the method is based on the inclination of the tomographic axis with respect to the incident X‐ray beam by a defined angle. With the microsystem aligned roughly perpendicular to the rotation axis, the integral X‐ray transmission on the two‐dimensional (2D) detector does not change exceedingly during the scan. In consequence, the integrity of laterally extended devices can be preserved, what distinguishes SRCL from CT where ROIs have to be destructively extracted (e.g. by cutting out a sample) before being imaged. The potential of the method for three‐dimensional imaging of microsystem devices will be demonstrated by examples of flip‐chip bonded and wire‐bonded devices. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time and in situ solidification of Al‐based alloys investigated by synchrotron radiation: a unique experimental set‐up combining radiography and topography techniques
Authors: Buffet A. , Reinhart G. , Schenk T. , Nguyen‐Thi H. , Gastaldi J. , Mangelinck‐Noël N. , Jung H. , Härtwig J. , Baruchel J. , Billia B.
Published: July 2007

This special issue's cover shows a radiograph and a topograph recorded during Al–3.5 wt% Ni alloy solidification. On the radiograph (left), one can observe the development of a branching structure known as dendrite. The high quality of the dendrite in the early stage of the growth is confirmed by the equal‐thickness fringes which are visible within the solid in the topograph (middle and right). Those fringes evidence the absence of defects within the microstructure.

The alloy's properties are largely controlled by the microstructure emerging during the growth process. As most of the phenomena involved during directional solidification are dynamic, it is crucial to perform an in situ and real‐time investigation. A unique experimental set‐up combining X‐ray radiography and topography has been recently developed at the ESRF (European Synchrotron Radiation Facility). It allows direct observation of the microstructure during directional solidification [1].

The first author of the article is a PhD student at the ESRF (Grenoble). Her research focuses on Al‐based alloy solidification and more particularly on strains, stresses and defect formation during directional solidification. She is working in collaboration with the L2MP (CNRS, Marseille). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A comparison of two‐particle models for conduction electron scattering on hydrogen‐like impurity ions in non‐degenerate semiconductors
Authors: Poklonski N. A. , Kocherzhenko A. A. , Vyrko S. A. , Vlassov A. T.
Published: July 2007

Models of electron mobility limited by scattering of conduction electrons on hydrogen‐like impurity ions in non‐degenerate crystalline semiconductors are discussed. It is shown that the best agreement with experimental data is given by a model earlier proposed by the authors, in which the time of electron‐ion interaction, equal to the time of transfer of a conduction electron across a spherical region corresponding to one impurity ion in the crystal, is taken into account, the minimum scattering angle is chosen according to Conwell–Weisskopf, and scattering acts of an electron on impurity ions are considered independent and incompatible events. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of strain relaxation mechanism in small SiGe clusters
Authors: Marim L. R. , Ueno L. T. , Machado F. B. C. , Dal Pino A.
Published: July 2007

We have performed a systematic search for the ground‐state geometry of Sin Gem neutral clusters (n + m = 3–5, 7). A number of low‐energy geometric isomers were optimized using reliable total‐energy calculations through B3LYP hybrid method. Harmonic vibrational analysis has been performed to assure that the optimized geometries are stable. Due to its larger size, the replacement of a silicon atom by a germanium one generates strain that affects the atomic configurations. Our results indicate that a bond‐stretching mechanism is the dominant effect that determines the geometry of the clusters. Our calculations have shown that as the number of Ge atoms increases, the average interatomic distance among all atoms in the cluster grows linearly. Such behavior can be understood as a cluster analog to Vegard's law for alloys. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical studies of mechanism of cycloaddition reaction between germylidene and formaldehyde
Authors: Lu Xiu Hui , Xu Yue Hua , Xiang Ping Ping , Che Xin
Published: July 2007

Mechanism of the cycloadditional reaction between singlet germylidene (R1) and formaldehyde (R2) has been investigated with MP2/6‐31G* method, including geometry optimization, and vibrational analysis for the involved stationary points on the potential energy surface. The energies of the different conformations are calculated by CCSD(T)//MP2/6‐31G* method. From the potential energy profile, it can be predicted that the dominant reaction pathway of the cycloadditional reaction between singlet germylidene and formaldehyde is reaction (4), which consists of three steps: the two reactants (R1, R2) first form an intermediate INT1b through a barrier‐free exothermic reaction of 28.1 kJ/mol; this intermediate reacts further with formaldehyde (R2) to give an intermediate INT4, which is also a barrier‐free exothermic reaction of 37.2 kJ/mol; subsequently, the intermediate INT4 isomerizes to a heteropolycyclic germanic compound P4 via a transition state TS4, for which the barrier is 18.6 kJ/mol. The dominant reaction has an excellent selectivity and differs considerably from its competitive reactions in thermodynamic property and reaction rate. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
First‐principles properties of organic polymer photovoltaic materials
Authors: Jayasekera T. , Monigold M. S. , Elizondo S. L. , Mintmire J. W.
Published: July 2007

One major approach for efficient photovoltaic devices based on polymeric materials lies in the use of bulk heterojunctions, which mix two different organic polymeric materials acting as donor and acceptor semiconductors. In these bulk heterojunctions the donor polymer typically acts as the light absorber, creating an electron‐hole pair and then donating the excited electron to the acceptor polymer. A deep theoretical understanding of the physical processes at work in these materials will require a knowledge of the electron states near the Fermi level for both the donor and acceptor. Bulk heterojunction systems based on mixtures of single‐wall carbon nanotubes and poly(3‐octylthiophene) have recently been reported in the literature. We calculate the electronic structure for both semiconducting and metallic single‐wall nanotubes, and compare these with electronic structure results for poly(3‐methylthiophene) as a model for the poly(3‐alkyl‐thiophenes). We also present results for the effective mass of single‐wall carbon nanotubes and poly(3‐methyl‐thiophene) using the calculated electronic band structures. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Solvation effect on the interaction between sodium and chloride ions in aqueous solution: An analysis based on the new resonance theory
Authors: Ikeda Atsushi , Yokogawa Daisuke , Sato Hirofumi , Sakaki Shigeyoshi
Published: July 2007

The solvation effect on the nature of the interaction between sodium and chloride ions in aqueous solution is investigated theoretically by using the combination of RISM‐SCF method and the analysis of molecular orbital wave function based on the new resonance theory. This strategy offers unified understandings of the nature of the interatomic interaction in solution together with the statistical distribution of solvent water molecules. The results show that, in aqueous phase, the weight of covalent interaction decrease rapidly with increase the distance between sodium and chloride and, at the same time, coordination number of solvent increase. We also find the solvation effect enhances the ionic character of the interaction by up to 20%. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Peptide retention prediction applied to proteomic data analysis
Authors: Gilar Martin , Jaworski Aleksander , Olivova Petra , Gebler John C.
Published: July 2007

A retention prediction model was developed for peptides separated in reversed‐phase chromatography. The model was utilized to identify and exclude the false positive (FP) peptide identifications obtained via database search. The selected database included human proteins, as well as decoy sequences of random proteins. The FP peptide detection rate was defined either as number of retention time outliers, or random decoy sequence identifications. The FP rate for various MASCOT scores was calculated. The peptides identified in one‐dimensional (1D) and two‐dimensional (2D) liquid chromatography/mass spectrometry (LC/MS) experiments were validated by prediction models. Multi‐dimensional LC was based on two orthogonal reversed‐phase chromatography modes; prediction models were successfully applied for data filtering in both separation dimensions. Copyright © 2007 John Wiley & Sons, Ltd.
Matrix‐assisted laser desorption/ionization time‐of‐flight based wheat gliadin protein peaks are useful molecular markers for wheat genetic study
Authors: Chen J. , Lan P. , Tarr A. , Yan Y. M. , Francki M. , Appels R. , Ma W.
Published: July 2007

Matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) instrumentation has been used to analyze wheat seed gliadins as an alternative to other established methods, including sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE), capillary electrophoresis (CE), high‐performance liquid chromatography (HPLC), etc. The MALDI‐TOF approach has shown to have many advantages such as high resolution, cost effectiveness and high throughput. MALDI‐TOF‐based gliadin profiles have been used for fast wheat cultivar identification. However, the genetic information represented by individual gliadin peaks has not been utilized. In this study a wheat doubled haploid population with a genetic linkage map of good coverage was used to assay individual gliadin peaks from MALDI‐TOF profiles as molecular markers. Eight segregating peaks in the population were scored as polymorphic across the population. The 1 to 1 segregating ratios validated the scoring of the peaks and all peaks were mapped to the expected chromosomes or linkage groups on the available linkage map: 1 peak on chromosome 1A, 1 on 6A, 4 on 6B and 2 on 6D. Copyright © 2007 John Wiley & Sons, Ltd.
Detection of potential ion suppression for peptide analysis in nanoflow liquid chromatography/mass spectrometry
Authors: Hirabayashi Atsumu , Ishimaru Masako , Manri Naomi , Yokosuka Toshiyuki , Hanzawa Hiroko
Published: July 2007

A detection technique for ion suppression in liquid chromatography/mass spectrometry (LC/MS) was developed by adding a probe to an LC mobile phase at a certain concentration. The probe is so hydrophilic that it is not adsorbed in a reversed‐phase nanoflow LC column, and, furthermore, has an isoelectric point of about 3, which is lower than that for most peptides and is close to the pH of the mobile phase. The intensity of the protonated probe molecule decreases much more than that of other peptides when ion suppression occurs. Thus, the occurrence of the ion suppression is detected by a decrease in the mass chromatogram for the protonated probe molecule, and the decrease ratio is higher than that for other ions. Copyright © 2007 John Wiley & Sons, Ltd.
Acoustic emission evaluation of the fracture behavior of APS‐TBCs subjecting to bondcoating oxidation
Authors: Yang L. , Zhou Y. C. , Mao W. G. , Liu Q. X.
Published: July 2007

Air‐plasma‐sprayed (APS) thermal barrier coatings (TBCs) under the conditions of without TBC, as‐sprayed and preoxidized, were tested under tensile loading, and their acoustic emission (AE) responses were monitored. AE parameters including event count, amplitude, and frequency spectrum realized by Fast Fourier Transformation (FFT) were analyzed for information regarding the fracture behavior of TBCs. On the basis of AE behavior, the fracture process of TBCs and corresponding cracking patterns in TBCs subjected to tensile tests were evaluated. AE results also showed that the bondcoating oxidation not only promotes the cracking but also changes the failure mode in TBCs. Copyright © 2007 John Wiley & Sons, Ltd.
Interface features of ultrasonic flip chip bonding and reflow soldering in microelectronic packaging
Authors: Duan Ji‐An , Li Junhui , Han Lei , Zhong Jue
Published: July 2007

Ultrasonic features in the bonding area are of interest for researchers in the field of microelectronic packaging. In this study, the interface characteristics of bonding were examined using an XD7100 X‐ray instrument and a transmission electron microscope (TEM). It was seen that bubbles were usually detected at the interfaces of the reflow‐soldered flip chip (FC), but they were not found at the interfaces of ultrasonically formed FC, and so ultrasonic FC bonding is more reliable than reflow soldering. The strong mechanical effect of ultrasonic vibration activates the dislocations in the crystalline metal lattice. Dislocation diffusion is more prominent than crystal diffusion when the temperature is relatively low during ultrasonic bonding, and therefore the processes of ultrasonic bonding enhance by several orders of magnitude. This indicates that the mechanism of ultrasonic bonding is different from the melting mechanism of reflow soldering. Copyright © 2007 John Wiley & Sons, Ltd.
Demographic responses of an arboreal marsupial, the common brushtail possum (Trichosurus vulpecula), to a prescribed fire
Authors: Isaac Joanne L. , Valentine Leonie E. , Goodman Brett A.
Published: July 2007

We investigated demographic responses of the common brushtail possum Trichosurus vulpecula, a medium‐sized arboreal marsupial, after a prescribed fuel reduction burn on Magnetic Island, tropical north Queensland, Australia. Possums were live‐trapped every month for 14 months before the fire and 11 months after the fire in both the burnt and unburnt areas; measurements of individuals were taken each month and demographic parameters were modelled using capture–mark–recapture data. Significant differences between the burnt and unburnt sites were found following the fire; recruitment was lower in the unburnt area, where population size also declined. In the burnt area, population size and recruitment displayed a tendency to increase after the fire, while capture probability declined, suggesting that an influx of new individuals, attracted to re‐sprouting vegetation, had resulted in trap saturation. There was no detectable effect of the fire on survival, and no fire‐induced mortalities were observed. We conclude that a low‐intensity, prescribed, fuel‐reduction burn had no obvious negative consequences for this possum population.
Cholesterol Reporter Molecules
Authors: Gimpl Gerald , Gehrig-Burger Katja
Published: July 2007

Cholesterol is a major constituent of the membranes in most eukaryotic cells where it fulfills multiple functions. Cholesterol regulates the physical state of the phospholipid bilayer, affects the activity of several membrane proteins, and is the precursor for steroid hormones and bile acids. Cholesterol plays a crucial role in the formation of membrane microdomains such as “lipid rafts” and caveolae. However, our current understanding on the membrane organization, intracellular distribution and trafficking of cholesterol is rather poor. This is mainly due to inherent difficulties to label and track this small lipid. In this review, we describe different approaches to detect cholesterol in vitro and in vivo. Cholesterol reporter molecules can be classified in two groups: cholesterol binding molecules and cholesterol analogues. The enzyme cholesterol oxidase is used for the determination of cholesterol in serum and food. Susceptibility to cholesterol oxidase can provide information about localization, transfer kinetics, or transbilayer distribution of cholesterol in membranes and cells. The polyene filipin forms a fluorescent complex with cholesterol and is commonly used to visualize the cellular distribution of free cholesterol. Perfringolysin O, a cholesterol binding cytolysin, selectively recognizes cholesterol-rich structures. Photoreactive cholesterol probes are appropriate tools to analyze or to identify cholesterol binding proteins. Among the fluorescent cholesterol analogues one can distinguish probes with intrinsic fluorescence (e.g., dehydroergosterol) from those possessing an attached fluorophore group. We summarize and critically discuss the features of the different cholesterol reporter molecules with a special focus on recent imaging approaches.
A Model-Based Approach for Visualizing the Dimensional Structure of Ordered Successive Categories Preference Data
Authors: DeSarbo Wayne S. , Park Joonwook , Scott Crystal J.
Published: July 2007

A cyclical conditional maximum likelihood estimation procedure is developed for the multidimensional unfolding of two- or three-way dominance data (e.g., preference, choice, consideration) measured on ordered successive category rating scales. The technical description of the proposed model and estimation procedure are discussed, as well as the rather unique joint spaces derived. We then conduct a modest Monte Carlo simulation to demonstrate the parameter recovery of the proposed methodology, as well as investigate the performance of various information heuristics for dimension selection. A consumer psychology application is provided where the spatial results of the proposed model are compared to solutions derived from various traditional multidimensional unfolding procedures. This application deals with consumers intending to buy new luxury sport-utility vehicles (SUVs). Finally, directions for future research are discussed.
A new approach to the treatment of congenital vertical talus
Authors: Alaee Farhang , Boehm Stephanie , Dobbs Matthew B.
Published: July 2007

Congenital vertical talus is an uncommon foot deformity that is present at birth and results in a rigid flatfoot deformity. Left untreated the deformity can result in pain and disability. Though the exact etiology of vertical talus is unknown, an increasing number of cases have been shown to have a genetic cause. Approximately 50% of all cases of vertical talus are associated with other neuromuscular abnormalities or known genetic syndromes. The remaining 50% of cases were once thought to be idiopathic in nature. However, there is increasing evidence that many of these cases are related to single gene defects. Most patients with vertical talus have been treated with major reconstructive surgeries that are fraught with complications such as wound necrosis, talar necrosis, undercorrection of the deformity, stiffness of the ankle and subtalar joint, and the eventual need for multiple operative procedures. Recently, a new approach to vertical talus that consists of serial casting and minimal surgery has resulted in excellent correction in the short-term. Longer follow-up will be necessary to ensure maintenance of correction with this new technique. A less invasive approach to the correction of vertical talus may provide more favorable long-term outcomes than more extensive surgery as has been shown to be true for clubfoot outcomes.
The impact of specialist care for low back pain on health service utilization in primary care patients: A prospective cohort study
Authors: Chenot Jean‐François , Leonhardt Corinna , Keller Stefan , Scherer Martin , Donner‐Banzhoff Norbert , Pfingsten Michael , Basler Heinz‐Dieter , Baum Erika , Kochen Michael M. , Becker Annette
Published: July 2007

Guidelines portray low back pain (LBP) as a benign self‐limiting disease which should be managed mainly by primary care physicians. For the German health care system we analyze which factors are associated with receiving specialist care and how this affects treatment. This is a longitudinal prospective cohort study. General practitioners recruited consecutive adult patients presenting with LBP. Data on physical function, on depression, and on utilization of health services were collected at the first consultation and at follow‐up telephone interviews for a period of 12 months. Logistic regression models were calculated to investigate predictors for specialist consultations and use of specific health care services. Large proportions (57%) of the 1342 patients were seeking additional specialist care. Although patients receiving specialist care had more often chronic LBP and a positive depression score, the association was weak. A total of 623 (46%) patients received some form of imaging, 654 (49%) physiotherapy and 417 (31%) massage. Consulting a specialist remained the strongest predictor for imaging and therapeutic interventions while disease‐related and socio‐demographic factors were less important. Our results suggest that the high use of specialist care in Germany is due to the absence of a functioning primary care gate keeping system for patient selection. The high dependence of health care service utilization on providers rather than clinical factors indicates an unsystematic and probably inadequate management of LBP.
TatBC, TatB, and TatC form structurally autonomous units within the twin arginine protein transport system of Escherichia coli
Authors: Orriss George L. , Tarry Michael J. , Ize Bérengère , Sargent Frank , Lea Susan M. , Palmer Tracy , Berks Ben C.
Published: July 2007

The Tat (twin arginine translocation) system transports folded proteins across bacterial and thylakoid membranes. The integral membrane proteins TatA, TatB, and TatC are the essential components of the Tat pathway in Escherichia coli. We demonstrate that formation of a stable complex between TatB and TatC does not require TatA or other Tat components. We show that the TatB and TatC proteins are each able to a form stable, defined, homomultimeric complexes. These we suggest correspond to structural subcomplexes within the parental TatBC complex. We infer that TatC forms a core to the TatBC complex on to which TatB assembles.
Identification of S6K2 as a centrosome‐located kinase
Authors: Rossi Rossella , Pester John M. , McDowell Mitch , Soza Samuela , Montecucco Alessandra , Lee-Fruman Kay K.
Published: July 2007

Ribosomal S6 kinase 2 (S6K2) acts downstream of the mammalian target of rapamycin (mTOR). Here, we show that some S6K2 localize at the centrosome throughout the cell cycle. S6K2 is found in the pericentriolar area of the centrosome. S6K2 centrosomal localization is unaffected by serum withdrawal or treatment with rapamycin, wortmannin, U0126, or phorbol‐12‐myristate‐13‐acetate (PMA). Unlike S6K2, S6 kinase 1 (S6K1) does not localize at the centrosome, suggesting the two kinases may also have nonoverlapping functions. Our data suggest that centrosomal S6K2 may have a role in the phosphoinositide‐3‐kinase (PI3K)/Akt/mTOR signaling pathway that has also been detected in the centrosome.
RETRACTED: Replication of an RNA ligase ribozyme under alternating temperature condition
Authors: Kim Ki-Sun , Choi Woo-Hyung , Choi Bo-Ra , Oh Sangtaek , Yea Sung Su , Yoon Moon-Young , Kim Dong-Eun
Published: July 2007

Felix Wieland, Managing Editor
Women's experiences following failed vaginal birth after cesarean delivery
Authors: Chigbu C.O. , Enwereji J.O. , Ikeme A.C.
Published: July 2007

Objective

To assess the experience of women in whom a trial of vaginal birth after cesarean (VBAC) has failed.

Methods

Pretested self‐administered questionnaires containing both open‐ and closed‐ended questions were given to the participants while they were waiting for an antenatal check‐up. The responses to the closed‐ended questions were analyzed with descriptive statistics. Content analysis was used for the responses to the open‐ended questions.

Results

The women with a history of a successful vaginal delivery reported a positive experience whereas those with no history of vaginal delivery reported a negative experience. The women found the limited options available to them the most dissatisfying aspect of attempting a VBAC.

Conclusion

An unsuccessful trial of VBAC could have significant adverse effects on women, especially on those who have never given birth vaginally. Adequate antenatal education for women planning a trial of VBAC, postdelivery support following an unsuccessful trial of VBAC, and research aimed at expanding the options available to women as they are attempting VBAC are recommended.
Pediatric Head and Neck Trauma from All‐Terrain Vehicle Accidents
Authors: Wang Brian S. , Smith Stacey L. , Pereira Kevin D.
Published: July 2007

OBJECTIVE

To characterize pediatric head and neck trauma from all‐terrain vehicles (ATVs) at a single institution.

STUDY DESIGN/SETTING

Retrospective case series at a level I pediatric trauma center.

RESULTS

Thirty‐four patients were admitted: average age was 12 years, with 68% between 12 and 16 years and 32% under 12 years. The patient was the driver in 74% of cases and the passenger in 17% of cases. Driver average age was 12.7 years and passenger average age was 10.5 years. Seventy‐six percent of children were not wearing helmets. Average hospital stay was 6 days, with 81% of cases discharged home. Central nervous system injuries were most common, followed by soft tissue injuries. Soft tissue repair was the most frequent procedure, and most maxillofacial fractures required operative intervention.

CONCLUSIONS

ATV‐related morbidity and mortality in children are significant public health issues amenable to primary prevention by prohibiting passengers on ATVs and requiring helmet use.

SIGNIFICANCE

National trends indicate increasing ATV‐related injuries in children.
In Vitro Discrimination of Tumor Cell Lines with an Electronic Nose
Authors: Gendron Kristin B. , Hockstein Neil G. , Thaler Erica R. , Vachani Anil , Hanson C. William
Published: July 2007

OBJECTIVE

The electronic nose is a sensor of volatile molecules that is useful in the analysis of expired gases. Our hypothesis is that the electronic nose can distinguish between different types of upper aerodigestive tract tumor cells in vitro.

STUDY DESIGN

Cells from both tumor and normal cell lines were suspended in saline, and a polymer composite electronic nose was used to evaluate the headspace gases. The data were subjected to principal components analysis, and Mahalanobis distances were calculated to demonstrate the ability of the electronic nose to distinguish among samples.

RESULTS

The tumor cell lines, including adenocarcinoma, squamous cell carcinoma, and mesothelioma, were distinct from each other, and from the normal fibroblast and smooth muscle cells as seen on canonical discrimination plots.

CONCLUSION

The electronic nose can distinguish between tumor cell lines in vitro and has the potential to be a useful screening test for cancer.
The Inhibitory Effects of Macrolide Antibiotics on Bone Remodeling in Chronic Rhinosinusitis
Authors: Park Chan‐Soon , Park Yong‐Soo , Park Yong‐Jin , Cho Jin‐Hee , Kang Jun‐Myung , Kim Soo‐Yeon
Published: July 2007

OBJECTIVE

To investigate the effect of nasal mucosal inflammation on bone remodeling and the inhibitory effect of macrolide antibiotics on bone remodeling through the inhibition of receptor activator of nuclear factor‐kB ligand (RANKL) and macrophage colony‐stimulating factor (M‐CSF).

STUDY DESIGN AND SETTING

Human nasal fibroblasts were primary‐cultured from nasal polyp. After interleukin (IL)‐1β stimulation of fibroblasts with or without macrolide pretreatment, real‐time polymerase chain reaction for RANKL messenger RNA (mRNA) and enzyme‐linked immunosorbent assay for M‐CSF were performed at various intervals. Peripheral blood mononuclear cells (PBMCs) were cultured for 10 days with M‐CSF only, M‐CSF plus RANKL, or macrolide antibiotic plus M‐CSF and RANKL.

RESULTS

IL‐1β stimulation of nasal polyp fibroblasts induced expression of RANKL mRNA and secretion of M‐CSF. Macrolide antibiotics reduced RANKL mRNA and M‐CSF expression by nasal polyp fibroblasts in a dose‐dependent manner, and inhibited osteoclastogenesis from PBMCs.

CONCLUSION

Nasal fibroblasts stimulated with IL‐1β may take on the role of osteoblasts in osteoclastogenesis, which may be inhibited by macrolide antibiotics.
Immune Modulatory Oligonucleotides in the Prevention and Treatment of OVA‐Induced Eustachian Tube Dysfunction in Rats
Authors: Blanks Deidra A. , Ebert Charles S. , Eapen Rose P. , Zdanski Carlton , Kandimalla Ekambar R. , Agrawal Sudhir , Prazma Jiri
Published: July 2007

BACKGROUND

Otitis media with effusion (OME) is often associated with allergies. Immune modulatory oligonucleotides (IMO) mediate allergic inflammation and may therefore be efficacious in the treatment of airway inflammation.

OBJECTIVE

To evaluate the role of an IMO via transtympanic mucosal application in prevention and treatment of ovalbumin‐induced OME.

DESIGN

Forty brown Norway rats were divided into control and treatment groups. Eustachian tube dysfunction was evaluated by passive opening pressures, passive closing pressures, active clearance of negative pressure, and mucociliary clearance transit time.

RESULTS

Rats who underwent IMO treatment required 50% less pressure to open and close the eustachian tube (P < 0.05) and were able to actively clear 50% more negative pressure than the ovalbumin‐control rats (P < 0.001). The treatment rats' mucociliary clearance time was half that of the control group (P < 0.001).

CONCLUSION

IMO via transtympanic application can prevent and treat allergy‐induced eustachian tube dysfunction in rats. IMO may offer substantial promise in the future management of OME.
Utility of Head and Neck Biopsies in the Evaluation of Posttransplant Lymphoproliferative Disorder
Authors: Campisi Paolo , Allen Upton D. , Ngan Bo‐Yee , Hawkes Michael , Forte Vito
Published: July 2007

OBJECTIVE

To determine the diagnostic yield of head and neck biopsies in the evaluation of PTLD in children and to explore whether this yield was related to pretransplant Epstein‐Barr virus (EBV) serostatus.

STUDY DESIGN

This is a retrospective study of pediatric, post‐solid‐organ transplant recipients who have undergone a biopsy in the head and neck region to establish a diagnosis of PTLD.

RESULTS

Fifty‐six biopsies were performed in 46 patients four to 120 months after solid‐organ transplantation. Biopsies yielded PTLD in 39.1% of patients. The odds of developing PTLD if a patient was seropositive for EBV at the time of transplantation was 0.26 (95% confidence interval, 0.064‐1.056; P = 0.054).

CONCLUSIONS

The high diagnostic yield of PTLD suggests that biopsies should be performed if PTLD is suspected in pediatric posttransplant patients. The results demonstrate a trend toward lower risk of PTLD among patients with pretransplant exposure to EBV.
Tracheotomy in the Preschool Population: Indications and Outcomes
Authors: French Lesley C. , Wootten Christopher T. , Thomas Robert G. , Neblett Wallace W. , Werkhaven Jay A. , Cofer Shelagh A.
Published: July 2007

OBJECTIVE

Although more tracheotomy procedures are performed within the first year of life than in any other age group, preschool‐aged children requiring tracheotomy remain understudied. We characterize the indications and outcomes for patients between the ages of 3 and 6 years undergoing tracheotomy.

METHODS

Out of 480 pediatric tracheotomy procedures performed at a tertiary‐care hospital between 1988 and 2004, 15 patients underwent primary tracheotomy between 3 and 6 years of age.

RESULTS

Most (60%) procedures were performed for pulmonary toilet. Upper‐airway obstruction represented the second most common indication (40%), and trauma necessitated tracheotomy procedures more often than had been predicted (40%). The decannulation rate was 40%; 2 patients died.

CONCLUSION

Trauma contributed to both upper‐airway obstruction as well as requirements for pulmonary toilet. These procedures performed secondary to trauma will likely continue to increase.

SIGNIFICANCE

Tracheotomy procedures in the preschool population remain uncommon; however, nearly half of those studied were performed as a direct result of otherwise preventable trauma.
Stratification for Malignant External Otitis
Authors: Peleg Uri , Perez Ronen , Raveh David , Berelowitz Daniel , Cohen David
Published: July 2007

OBJECTIVE

To propose a CT‐based method for early identification of severe cases of malignant external otitis (MEO) by correlating between initial CT findings and clinical course.

STUDY DESIGN AND SETTING

Eighteen MEO patients who underwent CT on admission were included in this retrospective study conducted at a tertiary center. The number and extent of anatomical areas involved according to CT were compared to clinical course severity.

RESULTS

The patients were categorized into two groups according to clinical course. There were 13 patients in the “nonsevere” group and 5 in the “severe.” In six out of eight CT anatomical areas the “severe” group had significantly higher scores (P< 0.05 toP< 0.0005). The average number of areas involved in the “nonsevere” group was 2.9 and in the “severe” 5.4 (P< 0.0005).

CONCLUSION

We found a clear correlation between clinical course and initial CT findings in MEO patients. Based on these findings it may be possible to predict clinical course severity according to initial CT.
Survey of Ménière's Disease in a Subspecialty Referral Practice
Authors: Vrabec Jeffrey T. , Simon Lawrence M. , Coker Newton J.
Published: July 2007

OBJECTIVES

To define the prevalence of definite Ménière's disease (MD) among patients presenting with characteristic symptoms and examine the utility of published diagnostic guidelines.

STUDY DESIGN AND SETTING

Retrospective review in an academic referral practice.

RESULTS

The prevalence of definite MD in these 295 individuals was 64%. The next‐largest group (23%) consisted of patients with only cochlear symptoms. Those initially classified as probable are usually reclassified as definite with extended follow‐up. Of those with definite MD, the mean duration of disease at last follow‐up was 7.6 years, 56% were female, 19% had bilateral disease, and 34% required surgical management for vertigo.

CONCLUSIONS

The 1995 AAO‐HNS guidelines are useful for classification of MD according to certainty of diagnosis and severity of disease, though some modifications could be considered.

SIGNIFICANCE

Application of consistent diagnostic criteria is essential for epidemiological, genetic, or outcomes studies of Ménière's disease.
Pediatric Cartilage Interleave Tympanoplasty
Authors: Gaslin Michael , O'Reilly Robert C. , Morlet Thierry , McCormick Michael
Published: July 2007

OBJECTIVE

To describe a novel technique of cartilage tympanoplasty, and review surgical and hearing results in children.

STUDY DESIGN AND SETTING

Retrospective chart review of all patients who had undergone tympanoplasty at a pediatric tertiary care hospital from August 2002 to July 2005. Forty‐two patients were identified with a minimum follow‐up time of 12 months.

RESULTS

Mean preoperative perforation size was 21.3 percent (range 10%‐90%), and mean patient age was 7.9 years (range 3‐16 years). Median clinical follow‐up was 24 months. Tympanic membrane closure and graft integration were achieved in 40 of 42 patients (95.2%), and 35 of 42 (85.7%) patients maintained an intact, stable tympanic membrane on long‐term follow‐up. A total of 93.8 percent of patients achieved a postoperative air‐bone gap of less than or equal to 20 dB, and mean improvement in the air‐bone gap was 10.7 dB.

CONCLUSION AND SIGNIFICANCE

Cartilage interleave tympanoplasty is a versatile, stable, and effective technique for tympanic membrane repair in children.
Immune Modulatory Oligonucleotides in Prevention of Nasal Allergen—Induced Eustachian Tube Dysfunction in Rats
Authors: Ebert Charles S. , Rose Austin S. , Blanks Deidra A. , Eapen Rose P. , Kandimalla Ekambar R. , Agrawal Sudhir , Prazma Jiri , Pillsbury Harold C.
Published: July 2007

OBJECTIVES

Develop a model of nasal allergen‐induced Eustachian tube dysfunction (ETD) in a rat and investigate the role of immune modulatory oligonucleotides (IMOs) in the prevention of nasal allergen‐induced ETD.

STUDY DESIGN AND SETTING

Prospective, randomized study. Brown Norway rats were sensitized to ova albumin (OVA) and randomized to receive pretreatment with IMOs or phosphate‐buffered saline. All animals were challenged intranasally with aerosolized OVA. Dynamic measures of Eustachian tube (ET) function were analyzed.

RESULTS

Animals that were OVA‐sensitized and IMO‐pre‐treated had significantly lower mean passive opening (95% confidence interval [95% CI] 15.0,19.4) and closing (95% CI 4.8,7.8) ET pressures compared with those of (95% CI 24.1,32.7) and (95% CI 12.1,18,8) OVA‐sensitized untreated rats, respectively. In addition, the IMO‐pretreated animals demonstrated the ability to actively clear a significantly higher proportion of negative pressure (95% CI 0.64,0.96) compared with the untreated animals (95% CI 0.09,0.39). IMO‐pretreated animals also demonstrated significantly improved mean mucociliary clearance times in seconds (95% CI 115,195) than those in untreated animals (95% CI 308,668).

CONCLUSIONS

Pretreatment with IMOs prevented allergen‐induced allergic inflammation around the Eustachian tube (ET) and resulted in improved ventilatory function of the ET compared with sensitized untreated animals. IMOs offer considerable promise in the management of nasal allergic disease as well as otitis media with effusion.