bluuebunny/crossref_metadata_2025 huggingface dataset:
Coadsorption of trimethyl phosphine and thiocyanate on colloidal silver: a SERS study combined with theoretical calculations
Authors: Hu Gengshen , Han Difei , Jia Guoqing , Chen Tao , Feng Zhaochi , Li Can
Published: November 2008

The adsorption of trimethyl phosphine (TMP) on colloidal silver has been investigated by means of surface‐enhanced Raman scattering spectroscopy (SERS). On the basis of surface selection rules, it is deduced from the SERS results that TMP adsorbs on silver surface via its P atom. The electron donor effect of TMP can be sensitively probed by the coadsorbed SCN−. The Raman wavenumber of νCN of the adsorbed SCN− shifts to lower wavenumbers when TMP is coadsorbed with SCN− and the red shift of C≡N stretching wavenumber is found to increase with increasing surface coverage of TMP. This could be explained in terms of the electron donor effect of TMP. Density functional theory (DFT) calculations further confirm the experimental results that the charge transfer is from TMP to silver surface rather than reversely. Natural bond orbital (NBO) analysis indicates that the red shift of C≡N stretching mode is due the increase of electronic populations of π* orbital of C≡N bond induced by coadsorbed TMP, consequently the C≡N bond is weakened, and the νCN shifts to lower wavenumbers. An NBO analysis also indicates that the conjugated effect between S atom and C≡N bond could easily make the charge transfer from silver surface to C≡N bond. Copyright © 2008 John Wiley & Sons, Ltd.
Establishing permissible erosion rates for various landforms in Delhi State, India
Authors: Jha P. , Nitant H. C. , Mandal D.
Published: November 2008

Permissible erosion rate also known as soil loss tolerance (‘T’ value) is defined as maximum erosion that can take place on a given soil without degrading its long‐term productivity. In India, default ‘T’ value of 11·2 Mg ha−1 y−1 is used for devising land restoration strategies for different types of soils. However, ability of soil to resist degradation varies with soil type, depth and physico‐chemical characteristics. Therefore, the present investigation was undertaken to determine ‘T’ value of different landforms of Delhi State by taking into account the soil saturated hydraulic conductivity (SHC), bulk density (BD), organic carbon, erodibility and soil pH. Soil state was defined by a quantitative model and scaling functions were used to convert soil parameters to a 0–1 scale. The normalised values were multiplied by appropriate weighting factors based on relative importance and sensitivity analysis of each indicator. Categorical rankings of I, II or III were assigned to soil groups based on overall aggregate score. ‘T’ value of different landforms of Delhi State was computed using the guideline of USDA‐Natural Resource Conservation Services. Majority of landforms of Delhi had ‘T’ value of 12·5 Mg ha−1 y−1, except for the soils of hill terrain, dissected hill, pediment and piedmont plain, where ‘T’ value ranged from 5 to 10 Mg ha−1 y−1. These ‘T’ values could be used for conservation planning and will help the planners in devising suitable land restoration strategies. Copyright © 2008 John Wiley & Sons, Ltd.
Chemoenzymatic Synthesis of Amylose‐Grafted Cellulose
Authors: Omagari Yuji , Matsuda Shun‐ichi , Kaneko Yoshiro , Kadokawa Jun‐ichi
Published: November 2008

This paper reports the chemoenzymatic synthesis of an amylose‐grafted cellulose. A maltoheptaose was chemically introduced to the amine‐functionalized cellulose by reductive amination to produce the maltoheptaose‐grafted cellulose. Then, the phosphorylase‐catalyzed enzymatic polymerization of glucose 1‐phosphate from the graft‐chain ends on the cellulose derivative was performed, giving the amylose‐grafted cellulose. The obtained material is shown to form gels and films. The dry and wet cycles of the materials were repeated.

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A Water‐Borne Adhesive Modeled after the Sandcastle Glue of P. californica
Authors: Shao Hui , Bachus Kent N. , Stewart Russell J.
Published: November 2008

Polyacrylate glue protein analogs of the glue secreted by Phragmatopoma californica, a marine polycheate, were synthesized with phosphate, primary amine, and catechol sidechains with molar ratios similar to the natural glue proteins. Aqueous mixtures of the mimetic polyelectrolytes condensed into liquid complex coacervates around neutral pH. Wet cortical bone specimens bonded with the coacervates, oxidatively crosslinked through catechol sidechains, had bond strengths nearly 40% of the strength of a commercial cyanoacrylate. The unique material properties of complex coacervates may be ideal for development of clinically useful adhesives and other biomaterials.

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Potential mapping technique for the detection of corrosion in reinforced concrete structures: Investigation of parameters influencing the measurement and determination of the reliability of the method
Authors: Schiegg Y. , Büchler M. , Brem M.
Published: November 2008

The potential distribution around a corrosion site in concrete was modeled by means of a simple mathematical model for a rod‐shaped anode. Based on these calculations the influencing parameters and the limits of the potential mapping technique were determined. They demonstrate that the location of anodes depends on the anode length, the concrete coverage, and the measuring grid. Moreover small anodes with less than 1 cm length are virtually impossible to localize. Investigations on concrete elements without reinforcing steel showed that heterogeneous water content and chloride distribution can result in potential differences of up to 150 mV on the concrete surface. This effect was related to the streaming potential and the diffusion overpotential in the concrete. In order to determine the reliability of the potential mapping technique in the field application, the concrete on a tunnel wall was removed after the measurement of the potential distribution and the corrosion loss of the steel was determined. It was found that all corrosion sites with more than 2 mm material loss were detected by the potential mapping technique. Only some smaller corrosion sites were not found. Based on this investigation, the applicability of the potential mapping technique for detecting corrosion sites was confirmed. The observed high reliability of the potential mapping technique can be explained by a combination of the heterogeneous wetting of the concrete, the inhomogeneous contamination with chloride, and the macrocell formation.
Real‐time monitoring of weather radar antenna pointing using digital terrain elevation and a Bayes clutter classifier
Authors: Rico‐Ramirez Miguel Angel , Gonzalez‐Ramirez Efren , Cluckie Ian , Han Dawei
Published: November 2008

This paper presents a novel technique to monitor continuously the azimuthal pointing accuracy of a weather radar antenna. The technique consists of cross‐correlating between modelled and measured echoes from ground clutter in real‐time at low elevation angles under precipitation and non‐precipitation conditions. The azimuthal angle lag with the maximum cross‐correlation indicates the adjustment needed in antenna pointing. The modelled ground clutter echoes were obtained using high‐resolution digital elevation model (DEM) data whereas the measured ground clutter echoes can be obtained in real‐time using a Bayes classifier, which identifies the clutter echoes in the presence of precipitation. The technique has been successfully tested in the Thurnham radar in Southeast England. This method can be used by data users as well as radar operators. It should complement the traditional methods based on sun measurements. Copyright © 2008 Royal Meteorological Society
NMR investigation of chlorophosphorylation products of N‐vinylazoles
Authors: Larina Lyudmila I. , Rozinov Vladimir G. , Dmitrichenko Mikhail Yu. , Es'kova Lyudmila A.
Published: November 2008

The structure of novel phosphorus‐containing N‐vinylazoles prepared by action of phosphorus pentachloride has been studied by multinuclear 1H, 13C, 15N, 31P and two‐dimensional (2D) NMR spectroscopy. N‐vinyl‐substituted 1,2‐diazoles and 1,2,3‐triazoles have undergone phosphorylation, exclusively, on double bond. N‐vinylazoles‐based hexa‐coordinated phosphorus compounds have been synthesized for the first time. 31P NMR spectroscopy provides the most convenient and unambiguous method for the investigation of E—Z‐isomeric structures of phosphorylated enamines. Copyright © 2008 John Wiley & Sons, Ltd.
Cortical voluntary activation of the human knee extensors can be reliably estimated using transcranial magnetic stimulation
Authors: Sidhu Simranjit K. , Bentley David J. , Carroll Timothy J.
Published: November 2008

The objective of this study was to determine if a transcranial magnetic stimulation (TMS) method of quantifying the degree to which the motor cortex drives the muscles during voluntary efforts can be reliably applied to the human knee extensors. Although the technique for estimating “cortical” voluntary activation (VA) is valid and reliable for elbow flexors and wrist extensors, evidence that it can be applied to muscles of the lower limb is necessary if twitch interpolation with TMS is to be widely used in research or clinical practice. Eight subjects completed two identical test sessions involving brief isometric knee extensions at forces ranging from rest to maximal voluntary contraction (MVC). Electromyographic (EMG) responses to TMS of the motor cortex and electrical stimulation of the femoral nerve were recorded from the rectus femoris (RF) and biceps femoris (BF) muscles, and knee extension twitch forces evoked by stimulation were measured. The amplitude of TMS‐evoked twitch forces decreased linearly between 25% and 100% MVC (r2 > 0.9), and produced reliable estimations of resting twitch and VA (ICC2,1 > 0.85). The reliability and size of cortical measures of VA were comparable to those derived from motor nerve stimulation when the resting twitches were estimated on the basis of as few as three TMS trials. Thus, TMS measures of VA may provide a reliable and valid tool in studies investigating central fatigue due to exercise and neurological deficits in neural drive in the lower limbs. © 2008 Wiley Periodicals, Inc. Muscle Nerve 2008
In vivo1H MRS of WSU‐DLCL2 human non‐Hodgkin's lymphoma xenografts: response to rituximab and rituximab plus CHOP
Authors: Lee Seung‐Cheol , Delikatny Edward J. , Poptani Harish , Pickup Stephen , Glickson Jerry D.
Published: November 2008

In order to identify early 1H MRS metabolic markers of response to rituximab immunotherapy and to rituximab plus CHOP (cyclophosphamide, hydroxydoxorubicin, vincristine, and prednisone) combination therapy, we performed an in vivo MRS investigation of a non‐Hodgkin's lymphoma (NHL) xenograft model. Human WSU‐DLCL2 NHL cells were subcutaneously implanted into flanks of female severe combined immunodeficient mice. When tumor volumes reached ∼600 mm3, rituximab was administered for three weekly cycles at a dose of 25 mg/kg per cycle with or without CHOP. Before and after treatment, tumor lactate (Lac) and total choline (tCho) were detected using the selective multiple quantum coherence sequence and the stimulated echo acquisition mode sequence, respectively. Rituximab produced a small tumor growth delay (∼5 days), whereas treatment with rituximab plus CHOP (RCHOP) led to ∼20% tumor regression after three cycles of therapy. After one cycle of rituximab, the tCho/H2O ratio had decreased significantly (5%, P = 0.003), whereas the Lac/H2O ratio had not changed (P = 0.58). Both Lac/H2O and tCho/H2O had decreased after one cycle of RCHOP treatment (26%, P = 0.001; 10%, P = 0.016, respectively). After two cycles of RCHOP, Ki67 assay of histological tumor specimens indicated ∼40% decrease in proliferation (P < 0.001) in the RCHOP‐treated tumors; no change was detected after treatment with rituximab alone. This study suggests that decreases in tCho/H2O are more sensitive indices of response to rituximab, whereas decreases in Lac/H2O are more sensitive to response to CHOP combination therapy. Copyright © 2008 John Wiley & Sons, Ltd.
Consistent interpolation of equidistantly sampled data
Authors: Rietsch Eike
Published: November 2008

Let u1, u2, …, uN with un∈ℝ denote the values of a function recorded or computed at N real and equidistant abscissa values tn=nΔt+t0 for n=1, …, N. A consistent interpolation operator L, as defined in this paper, interpolates these function values for N new abscissas tn = (n+½)Δt+t0, the first N−1 of which are halfway between those originally given while the last one is outside of the original abscissa range. Application of L to these interpolated function values produces the last N−1 samples u2, u3, …, uN of the original data plus one extrapolated function value uN+1. Hence, L2 is essentially a shift operator, but with a prediction component. The difference between various interpolation methods (e.g. polynomials, Fourier series) is now reduced to the way in which uN+1 is determined. This concept not only permits a uniform view at interpolation by quite different classes of functions but also allows the creation of more general interpolation, differentiation, and integration formulas, which can be tailored to particular problems. Copyright © 2008 John Wiley & Sons, Ltd.
TPMTgenetic variations in populations of the Russian Federation
Authors: Samochatova Elena V. , Chupova Natalia V. , Rudneva Anastassia , Makarova Olga , Nasedkina Tatyana V. , Fedorova Olga E. , Glotov Andrei S. , Kozhekbaeva Zh. , Maiorova Olga A. , Roumyantsev Alexander G. , Krynetski Eugene Y. , Krynetskaia Natalia F. , Evans William E. , Ribeiro Raul C.
Published: November 2008

Background

Polymorphisms that reduce the activity of thiopurineS‐methyltransferase (TPMT) cause adverse reactions to conventional doses of thiopurines, routinely used for antileukemic and immunosuppressive treatment. There are more than 20 variant alleles of TPMT that cause decreased enzymatic activity. We studied the most common variant alleles of TPMT and their frequency distribution in a large cohort of multiracial residents in the Russian Federation and compared their frequencies in children with and without malignancy to determine whetherTPMTgene abnormality is associated with hematologic malignancy.

Procedure

TheTPMTbiochip was used to detect 6TPMTsingle nucleotide polymorphisms (SNPs) corresponding to 7 TPMT‐deficiency alleles (TPMT*2,TPMT*3A,TPMT*3B,TPMT*3C,TPMT*3D,TPMT*7, andTPMT*8). We analyzed allele frequencies in the whole cohort, the childhood cancer group, and the non‐cancer group. We also characterized disease features and outcome according to the presence ofTPMTSNPs in children with acute lymphoblastic leukemia (ALL).

Results

Fifty‐five (5.5%) study participants overall had heterozygousTPMTgenotypes (1 variant and 1 wild‐type allele):TPMT*1/*3A(n = 45; 4.5%),TPMT*1/*3C(n = 8; 0.8%), andTPMT*1/*2(n = 2; 0.2%).TPMTSNPs were more frequent in children with hematologic malignancy than in other participants (7.5% vs. 4.0%,P = 0.02). We found no significant association betweenTPMTSNPs and ALL treatment outcome (median follow‐up, 31.3 months).

Conclusions

TPMT*3Ais the most prevalent variant allele in the Russian Federation. The estimated frequency of variant alleles in the study cohort (5.5%) was similar to that observed in the White populations in the U.S. and Eastern Europe. Pediatr Blood Cancer 2009;52:203–208. © 2008 Wiley‐Liss, Inc.
Immunization after the elective end of antineoplastic chemotherapy in children
Authors: Fioredda Francesca , Cavillo Michaela , Banov Laura , Plebani Alessandro , Timitilli Anna , Castagnola Elio
Published: November 2008

The aim of the present commentary is to discuss the multifaceted topic of vaccinations after treatment for cancer in the pediatric age. Publications in this field reveal conflicting data and opinions; no evidence‐based guidelines currently exist. However, in spite of several discrepancies some commonly accepted information and conclusions exist. Efforts to find a common strategy of re‐immunization should be directed towards setting up prospective studies on sufficient numbers of patients to obtain statistically relevant end points. Pediatr Blood Cancer 2009;52:165–168. © 2008 Wiley‐Liss, Inc.
Impact of a prescription monitoring program on doctor‐shopping for high dosage buprenorphine
Authors: Pradel Vincent , Frauger Elisabeth , Thirion Xavier , Ronfle Eléonore , Lapierre Véronique , Masut Alain , Coudert Christine , Blin Olivier , Micallef Joëlle
Published: November 2008

Purpose

Doctor‐shopping (simultaneous use of several physicians by a patient) is one of the most frequent ways of diversion for prescription drugs. A specific method was used to assess the evolution of doctor‐shopping for High Dosage Buprenorphine (HDB) in a French region from 2000 to 2005 and the impact of a prescription monitoring program for HDB implemented in 2004.

Methods

Data from eight periods (semesters of years 2000, 2002, 2004, and 2005) were extracted from a prescription database. Three quantities (the delivered, the prescribed, and the doctor‐shopping quantity) were computed for each patient. The total doctor‐shopping quantity and the doctor‐shopping ratio (percentage of buprenorphine obtained through doctor‐shopping) were used to evaluate the diversion of HDB among the population. The total prescribed quantity and the number of patients treated regularly were used as indicators of the access to treatment.

Results

The doctor‐shopping ratio increased from 1st semester 2000 to 1st semester 2004 (from 14.9 to 21.7%) and then decreased to 16.9% in 2nd semester 2005. The total doctor‐shopping quantity followed the same evolution. The number of patients treated remained stable from 1st semester 2000 to 2nd semester 2005. The prescribed quantity increased from 1st semester 2000 to 2nd semester 2002, decreased in 1st semester 2004 (4163 g) and then remained stable.

Conclusions

After a four‐year increase of the diversion through doctor‐shopping for buprenorphine the beginning of the prescription monitoring program was concomitant with a marked decrease of doctor‐shopping indicators without notable impact on the access to treatment. Copyright © 2008 John Wiley & Sons, Ltd.
Analysis of mold insert fabrication for the processing of microfluidic chip
Authors: Shen Y.K. , Lin J.D. , Hong R.H.
Published: November 2008

The microfluidic chip has been used as an example to discuss different mold insert materials by micro hot‐embossing molding. For the mold insert, this study uses the SU‐8 photoresist to coat on the silicon wafer, then uses UV light to expose the pattern on the surface of SU‐8 photoresist, and coat the seed layer on the SU‐8 structure using thermal evaporation. The micro electroforming technology has been combined to fabricate the mold inserts (Ni, Ni‐Co) followed by replicating the microstructure from the metal mold insert by micro‐hot embossing molding. Different processing parameters (Embossing temperature, embossing pressure, embossing time, and demolding temperature) for the properties of COP film of microfluidic chip have been discussed. The results show that the most important parameter is the embossing temperature for replication properties of molded microfluidic chip. The demolding temperature is the most important parameter for surface roughness of the molded microfluidic chip. The Ni‐Co mold insert is the most suitable mold material for molded microfluidic chip by microhot embossing molding. The bonding temperature is the most important factor for the bonding strength of sealed microfluidic chip by tensile bonding test. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers
Ultrasonic diagnosis of the single screw behavior during extrusion—A case study
Authors: Sun Zhigang , Utracki Leszek A.
Published: November 2008

Ultrasonic diagnostic method of screw behavior during extrusion has been designed, developed, and carried out on a 63.5‐mm single screw extruder, equipped with either a basic conveying screw or a mixing screw. It was found that the screw behavior depends on the screw speed and the die pressure. Whereas initially at low speed, the screw centered by the hydrodynamic forces rotates smoothly in the axial position, at higher screw speeds and high die pressures the screw starts vibrating. Thus, (1) the screw tip vibrated with the amplitude of 10–210 μm as the screw speed varied from 5 to 100 revolutions per minute; (2) the screw vibrations in the vertical and horizontal directions were asymmetrical; (3) the vibration pattern repeated itself at every two revolutions; (4) the vibrations originated in the poorly aligned engagement in the gearbox sleeve when the screw was pushed deeply into it by backpressure; (5) once pushed in the screw oscillated at any screw speed or die pressure. POLYM. ENG. SCI., 2009. Published by the Society of Plastics Engineers
Development of a Project Management Model for a Government Research and Development Organization
Authors: Procca Andrew E.
Published: November 2008

This article presents the results of an undergraduate project to develop a project management model for integration into a government research and development (GR&D) organization. The project was divided into three main phases: literature review, creation and execution of an organizational culture survey, and the development of a project management model compatible with GR&D organizations. It was found that, although there are cultural gaps between the GR&D and project management cultures, it is possible to bridge these gaps by a combination of training, organizational structure, and the application of project management techniques blended to match the type of research project and fundamental cultural assumptions.
Do Project Managers’ Leadership Competencies Contribute to Project Success?
Authors: Geoghegan Linda , Dulewicz Victor
Published: November 2008

This article explores the following hypothesis: There is a statistically significant relationship between a project manager's leadership competencies and project success. Two proven questionnaires, the leadership dimensions questionnaire (LDQ) and the project success questionnaire (PSQ), were used to gather data from 52 project managers and project sponsors from a financial services company in the United Kingdom. The results from the LDQ and PSQ are presented in this article. A factor analysis of PSQ revealed three independent factors: usability, project delivery, and value of output to clients. The last factor is not related to project leadership or management, so the article concentrates on correlations between the other two factors and project leadership. Eight separate leadership dimensions were found to be statistically significantly related to performance, so the hypothesis was largely supported. Identifying such relationships provides managers with guidance on possible selection and project improvement models, whereby increased capability in leadership dimensions can lead to increased success in project management.
Lyapunov‐based Model Predictive Control of Particulate Processes Subject to Asynchronous Measurements
Authors: Liu Jinfeng , Muñoz de la Peña David , Christofides Panagiotis D. , Davis James F.
Published: November 2008

This work focuses on state feedback, model predictive control of particulate processes subject to asynchronous measurements. A population balance model of a typical continuous crystallizer is taken as an application example. Three controllers, i.e., a standard model predictive controller and two recently proposed Lyapunov‐based model predictive controllers, are applied to stabilize the crystallizer at an open‐loop, unstable steady‐state in the presence of asynchronous measurements. The stability and robustness properties of the closed‐loop system under the three predictive controllers are compared extensively under three different assumptions on how the measurements from the crystallizer are obtained.
Pyroelectric properties of RbTiOAsO4 single crystals in the 4.2–300 K temperature range
Authors: Shaldin Yu. V. , Matyjasik S. , Tseitlin M. , Mojaev E. , Roth M.
Published: November 2008

The temperature dependence of the pyroelectric coefficient, γs, of RbTiOAsO4 single crystals grown by seeded pulling from high‐temperature self‐fluxes has been studied in the low‐temperature range. The results show that in the 4.2–250 K temperature range the γs(T) behavior is similar to those of the isomorphic crystals belonging to the KTP (KTiOPO4) family of compounds, and at temperature of 250 K the RTA pyroelectric coefficient γs = –(5.6 ± 0.3) × 10–5 C/m2 K. However, at temperatures above 275 K, the superionic conductivity increases significantly, while the electrical conductivity originating from the release of charge carriers associated with trace impurity point defects increases additionally above room temperature. These effects have been taken into account in experimental evaluation of the true γs values, especially above 275 K. The peculiarities revealed in the RTA pyroelectric coefficient temperature dependence are also discussed in terms of the structural changes associated with the temperature increase and isomorphic ion substitutions. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exact expression for Drude conductivity in one‐dimension with an arbitrary potential
Authors: Schulz Michael , Trimper Steffen
Published: November 2008

The electric current is calculated in the linear response regime by solving the Smoluchowski equation. To maintain a stationary current one needs the steady state distribution which differs from the equilibrium one. Due to the presence of an arbitrary crystal potential the conventional Drude conductivity is modified. We derive an exact expression for the conductivity in one dimension. The coupling between the applied electric field and the crystal potential leads to a systematic deformation of the potential that contributes to the renormalization of the electric field inside the system. The corrections to the Drude conductivity are determined completely by the configurational part of the partition function. The activation energy for the conductivity process is expressed by a combination of the free energy of the underlying equilibrium system. In case of a tight binding potential the conductivity offers corrections depending on the amplitude of the potential. The probability distribution for the charge carriers depends significantly on the electric field. As a further application we discuss nano‐contacts with piecewise constant potentials. The corrections to the electric conductivity are determined by the potential height. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Entangled photons from quantum dot devices: efficiency of post‐selection
Authors: Seliger Marek , Hohenester Ulrich , Pfanner Gernot
Published: November 2008

We theoretically investigate the production of polarization‐entangled photons through the biexciton cascade decay in a single semiconductor quantum dot. A biexciton radiatively decays through two intermediate exciton states, where polarization‐entangled photons are emitted if the two decay paths differ in polarization but are indistinguishable otherwise. This ideal performance is usually spoiled by the electron–hole exchange interaction splitting the intermediate exciton states by a small amount and consequently attaching a which‐path information to the photon frequencies. We discuss post‐selection schemes to mask this which‐path information to an outside observer. We show how spectral filtering and time shifts at a single photon level affect the photon state. Here the solid state environment plays a crucial role in the effective measurement of intermediate exciton states. Evaluating our analytical results with realistic quantum dot parameters we quantify the applicability of suggested protocols for solid‐state based quantum cryptography. Our results indicate, that a high degree of entanglement is only reached by spectral alignment of the exciton states. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assumed Peierls transition in NbS3 under pressure
Authors: Dizhur Eugene , Il'ina Maria , Zaitzev‐Zotov Sergey
Published: November 2008

The effect of pressure on the conduction of the NbS3 quasi‐one‐dimensional conductor is studied. A pressure induced insulator–metal transition is observed. The transition is accompanied by an increase in conductivity by six orders of magnitude at room temperature and the sign of thermal coefficient of resistance changes at pressure of about 5 GPa. An additional stepdown‐like feature appears in the temperature dependences of resistance that is interpreted as a Peierls transition. The transition temperature TP depends on pressure as TP [K] = 7.5P [GPa] + 202. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mild method for bulk enrichment of high‐aspect ratio SWNTs
Authors: Vichchulada Pornnipa , Vairavapandian Deepa , Lay Marcus D.
Published: November 2008

This manuscript presents an effective method for the removal of amorphous carbon, metal catalyst particles and bundled SWNTs, while leaving long/undamaged SWNTs in aqueous suspension. This involves multiple centrifuge cycles at low rotational centrifugal force (RCF), facilitating the formation of suspensions of pristine SWNTs with lengths up to 5 μm. Electrical characterization of deposits formed from these suspensions demonstrates the efficacy of this purification technique for creation of thin‐film semiconductive materials.

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(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallization of Fe75Zr25 metallic glass: a two‐step process involving metastable bcc‐Fe and polymorphic transformation
Authors: Gorria Pedro , Garitaonandia Joseba S. , Pérez María J. , Blanco Jesús A. , Campo Javier
Published: November 2008

The crystallization process of mechanically alloyed Fe75Zr25 metallic glasses is investigated by means of both thermo‐magnetization and in situ neutron powder thermo‐diffraction experiments in the temperature range 300–1073 K. It was found that the crystallization takes place in a two‐step process, involving firstly the appearance of metastable Fe and Fe2Zr crystalline phases between 880 K and 980 K, and a subsequent polymorphic transformation into Fe3Zr above 980 K. These findings explain the anomalous magnetization vs. temperature behaviour on heating–cooling cycles.

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Contour plot of the neutron diffracted intensity (λ = 1.28 Å) as a function of the Bragg diffraction angle and the temperature.

(© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correctness of the vertical discretization in hydrostatic atmospheric models
Authors: Bourchtein Andrei , Bourchtein Ludmila , Kadychnikov Vladimir
Published: November 2008

This study is about properties of the vertical structure matrices of hydrostatic atmospheric models. The main focus of this research is the influence of these matrices on the well‐posedness of vertically discretized initial value problems for linearized hydrostatic atmospheric equations. One of the results obtained states that the vertical structure matrices arising in the usual local vertical discretizations have oscillatory properties, which ensure the positivity of their spectrum and completeness of the set of eigenvectors. In such cases, well‐posedness of the initial value problems considered is proved analytically. Another result is a relation between locality of the vertical approximation and well‐posedness. Based on numerical experiments it is shown that greater non‐locality can lead to ill‐posed initial value problems. Copyright © 2008 Royal Meteorological Society
Observations of the development of convection through a series of stable layers during the Convective Storm Initiation Project
Authors: Bennett Lindsay J. , Blyth Alan M. , Browning Keith A. , Norton Emily G.
Published: November 2008

This article describes the development of convection through a series of stable layers on 20 July 2004 during the pilot project of the Convective Storm Initiation Project (CSIP). Convective clouds developed in south central England as a result of diurnal heating. They formed near the south coast and grew gradually as they moved northwards, eventually producing light precipitation. Several stable layers and associated dry layers (or lids) were observed by sequential radiosondes launched every two hours. Most of these lids were also detected by the Chilbolton L‐band radar and with a wind profiler as prominent layers of Bragg echo. One particular lid at 820 mb (1.7 km) inhibited the early development of the convection for about an hour, delaying the production of precipitation. The uppermost lid at 650 mb stopped all convection from intensifying in the CSIP domain.

Estimates of the growth of convection through the lids were sensitive to the values of temperature and humidity chosen to represent the ascending parcels. The development of the thermals in the boundary layer was best explained by using the surface‐layer average values. Parcels would not have been sufficiently buoyant to reach the lifting condensation level (LCL) unless these values were used. However, such parcels in the absence of mixing would then have been too buoyant to be capped by the main lid at 1.7 km, as was observed by the radars. In fact the development of the cumulus clouds above the LCL is best represented by using 950‐‐1000‐mb average thermodynamic values.

The results highlight the importance of predicting the altitude, strength and persistence of such lids in order to forecast the intensity, location and timing of convective precipitation more accurately. Copyright © 2008 Royal Meteorological Society
Prediction of Photolysis of PCDD/Fs Adsorbed to Spruce [Picea abies (L.) Karst.] Needle Surfaces Under Sunlight Irradiation Based on Projection Pursuit Regression
Authors: Yuan Yongna , Zhang Ruisheng , Hu Rongjing
Published: November 2008

Quantitative Structure–Property Relationship (QSPR) model for predicting the photolysis half‐life (t1/2) of PCDD/Fs sorbed to spruce [Picea abies (L.) Karst.] needle surfaces and irradiated by sunlight was firstly developed based on Projection Pursuit Regression (PPR), as a novel machine learning technique, by using the compounds' molecular descriptors calculated from the structure alone. PPR analysis for the PCDDs and PCDFs separately revealed that there is no correlation between them. Three molecular descriptors selected by the Heuristic Method (HM) for the PCDFs were used as inputs to perform Multiple Linear Regression (MLR) and PPR studies. Both linear and nonlinear models gave very satisfactory results: the square of correlation coefficient (R2) was 0.828 and 0.893, the Root Mean Square Error (RMSE) was 0.042 and 0.032, respectively, for the whole set. The proposed models can identify and provide some insight into what structural features are related to the log t1/2 values of compounds and help to improve the understanding for the photolysis mechanism of compounds under sunlight irradiation. Furthermore, this paper provided two new and effective methods for predicting the t1/2 values of the compounds from their structures and gave some insight into structural features related to the log t1/2 values of PCDFs.
Low‐frequency vibrational modes in blue opsin: A computational study
Authors: Thirumuruganandham Saravana Prakash , Urbassek Herbert M.
Published: November 2008

Vibrational excitations of low‐frequency collective modes are essential for functionally important conformational transitions in proteins. We have carried out an analysis of the low‐frequency modes in blue opsin based on both normal‐mode analysis and molecular dynamics simulations. Power spectra obtained by molecular dynamics agree well with the normal modes. A representative set of low‐frequency modes is discussed with the help of vector‐field representation. We thus demonstrate that terahertz spectroscopy of low‐frequency modes might be relevant for identifying those vibrational degrees of freedom that correlate to known conformational changes in opsins. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Photoelectrochemical Water Splitting Using Dense and Aligned TiO2 Nanorod Arrays
Authors: Wolcott Abraham , Smith Wilson A. , Kuykendall Tevye R. , Zhao Yiping , Zhang Jin Z.
Published: November 2008

Dense and aligned TiO2 nanorod arrays are fabricated using oblique‐angle deposition on indium tin oxide (ITO) conducting substrates. The TiO2 nanorods are measured to be 800–1100 nm in length and 45–400 nm in width with an anatase crystal phase. Coverage of the ITO is extremely high with 25 × 106 mm−2 of the TiO2 nanorods. The first use of these dense TiO2 nanorod arrays as working electrodes in photoelectrochemical (PEC) cells used for the generation of hydrogen by water splitting is demonstrated. A number of experimental techniques including UV/Vis absorption spectroscopy, X‐ray diffraction, high‐resolution scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and photoelectrochemistry are used to characterize their structural, optical, and electronic properties. Both UV/Vis and incident‐photon‐to‐current‐efficiency measurements show their photoresponse in the visible is limited but with a marked increase around ≈400 nm. Mott–Schottky measurements give a flat‐band potential (VFB) of +0.20 V, a carrier density of 4.5 × 1017 cm−3, and a space‐charge layer of 99 nm. Overall water splitting is observed with an applied overpotential at 1.0 V (versus Ag/AgCl) with a photo‐to‐hydrogen efficiency of 0.1%. The results suggest that these dense and aligned one‐dimensional TiO2 nanostructures are promising for hydrogen generation from water splitting based on PEC cells.
Enhanced expression of Hab18g/CD147 and activation of integrin pathway in HCC cells under 3‐D co‐culture conditions
Authors: Wu Ya‐Mei , Tang Juan , Zhao Pu , Chen Zhi‐Nan , Jiang Jian‐Li
Published: November 2008

CD147 is reported to be correlated with the malignancy of some cancers, and its overexpression affects the progression of tumor. In the present study, we investigated the function of HAb18G/CD147, a member of CD147 family, on hepatocellular carcinoma (HCC) adhesion, invasion and metastasis in 3‐dimensional (3‐D) cell co‐culture model. The results showed that the extracellular microenvironment could determine the cellular phenotypes and then affected the cellular functions. The expressions of HAb18G/CD147 in HCC cells and fibroblasts were both obviously elevated in 3‐D co‐culture model. The overexpression of HAb18G/CD147 increased MMPs' (MMP‐2 and MMP‐9) production (P < 0.01), and was obviously accompanied with enhanced expressions of paxillin, FAK and p‐FAK in 3‐D cell co‐culture model. All the results suggest that HAb18G/CD147 plays an important role in HCC adhesion, invasion and metastasis mainly via modulating synthesis of MMPs and activating integrin signal pathways in fibroblasts and tumor cells themselves under the 3‐D co‐culture conditions.
Methyl angolensate, a natural tetranortriterpenoid induces intrinsic apoptotic pathway in leukemic cells
Authors: Chiruvella Kishore K. , Kari Vijayalakshmi , Choudhary Bibha , Nambiar Mridula , Ghanta Rama Gopal , Raghavan Sathees C.
Published: November 2008

Methyl angolensate (MA), a natural tetranortriterpenoid, purified fromSoymida febrifugais examined for the first time for its anticancer properties. We find that MA inhibits growth of T‐cell leukemia and chronic myelogenous leukemia cells in a time‐ and dose‐dependent manner. Accumulation of cells in the subG1 peak, annexin V binding and DNA fragmentation suggested induction of apoptosis. Besides, upregulation of BAD (proapoptotic) and downregulation of BCL2 (antiapoptotic) gene products further supported induction of apoptosis. Loss of mitochondrial membrane potential, activation of caspase 9, caspase 3, cleavage of PARP, downregulation of Ku70/80 and phosphorylation of MAP kinases suggested that MA could induce intrinsic pathway of apoptosis in leukemic cells.
AtTIP1;3 and AtTIP5;1, the only highly expressed Arabidopsis pollen‐specific aquaporins, transport water and urea
Authors: Soto Gabriela , Alleva Karina , Mazzella María Agustina , Amodeo Gabriela , Muschietti Jorge P.
Published: November 2008

Pollination includes processes where water and/or solute movements must be finely regulated, suggesting participation of aquaporins. Using information available from different transcriptional profilings of Arabidopsis thaliana mature pollen, we showed that the only aquaporins that are selectively and highly expressed in mature pollen are two TIPs: AtTIP1;3 and AtTIP5;1. Pollen exhibited a lower number and more exclusive type of aquaporin expressed genes when compared to other single cell transcriptional profilings. When characterized using Xenopus oocyte swelling assays, AtTIP1;3 and AtTIP5;1 showed intermediate water permeabilities. Although they displayed neither glycerol nor boric acid permeability they both transported urea. In conclusion, these results suggest a function for AtTIP1;3 and AtTIP5;1 as specific water and urea channels in Arabidopsis pollen.
Demagnetization of Cochlear Implants and Temperature Changes in 3.0T MRI Environment
Authors: Majdani Omid , Leinung Martin , Rau Thomas , Akbarian Arash , Zimmerling Martin , Lenarz Minoo , Lenarz Thomas , Labadie Robert
Published: November 2008

Objective

To investigate the level of demagnetization of the magnets and temperature changes in cochlear implants (Cis) in a 3.0 tesla (3.0T) MRI.

Study Design

Experimental.

Subjects and Methods

Demagnetization and remagnetization measurements were done on magnets for different types of CIs. Temperature of different body and electrode sides was measured in the MRI environment.

Results

Demagnetization of the magnets of the CI is dependent on the angle between the magnetic field of the CI magnet and the MRI. When this angle was greater than 80 degrees, relevant demagnetization occurred and sufficient remagnetization was not possible with the 3.0T MRI magnet. Maximum temperature rise was 0.5°C.

Conclusions

Patients carrying CIs with non‐removable magnets should not enter a 3.0T MRI device in a routine clinical setup. Under special conditions (angle between the two magnets less than 80 degrees) imaging in a 3.0T MRI may be possible without harming the patient or the implant.
Ototoxicity of Topical Ciprofloxacin/Dexamethasone otic Suspension in a Chinchilla Animal Model
Authors: Daniel Sam J. , Munguia Raymundo
Published: November 2008

Objective

To determine the ototoxic potential of ciprofloxacin/dexamethasone eardrops.

Methods

Ventilation tubes were inserted in the ears of 15 chinchillas. One ear was randomized to receive four drops of ciprofloxacin/dexamethasone. A control solution (0.45% NaCl) was applied in the contralateral ear. The eardrops were delivered twice daily for 7 consecutive days. Auditory brain stem response (ABR) measurements were recorded at baseline (post‐tympanostomy tube insertion), and on days 4, 8, 15, 22, and 60.

Results

An initial transient increase of 8.11 dB nHL was noted in the mean thresholds of the experimental ears at day 4. On the last ABR evaluation (day 60), the mean thresholds were 16.33 ± 6.93 dB nHL in the experimental ears and 13.66 ± 6.65 dB nHL in the control ears. The difference in the mean thresholds between the experimental and control ears at day 60 was not significant (95% confidence interval, 3.12, –8.02). Scanning electron microscopy demonstrated normal morphology in all experimental ears that were assessed.

Conclusion

Ciprofloxacin/dexamethasone eardrops did not appear ototoxic when used in chinchillas post‐ventilation tube insertion.
Bone‐anchored hearing aid abutment skin overgrowth reduction with clobetasol
Authors: Falcone Michael T. , Kaylie David M. , Labadie Robert F. , Haynes David S.
Published: November 2008

Objectives

The bone‐anchored hearing aid (BAHA) osseointegrated cochlear stimulator can treat hearing loss in a variety of clinical situations. Occasionally skin/scar overgrowth may cover the abutment. This overgrowth interferes with affixing the BAHA to the abutment. Surgical scar revision/excision has been used to treat this problem. Clobetasol (0.05%), a steroid gel, can reduce skin overgrowth. Experience with skin overgrowth and the efficacy of clobetasol to treat this problem was reviewed.

Subjects and Methods

The authors conducted a retrospective analysis of patients who underwent BAHA abutment implantation from January 2003 through December 2006.

Results

Eighty‐eight patients (2 patients received bilateral BAHAs) were reviewed. Twenty (22%) of 90 sites developed overgrowth. Thirteen of 20 sites were treated with clobetasol. The overgrowth resolved in 11 (85%) of 13 sites after treatment. Patients with incomplete skin graft survival were significantly more likely to develop skin overgrowth (P = 0.0017).

Conclusion

Clobetasol is an effective treatment for abutment skin/scar overgrowth. Clobetasol allows patients to resume BAHA use and obviates the need for scar revision.
The impact of Radiotherapy on Swallowing and Speech in Patients who Undergo total Laryngectomy
Authors: de Casso Carmen , Slevin Nicholas J. , Homer Jarrod J.
Published: November 2008

Objectives

Quality of life studies have shown no detrimental effect with radiotherapy (RT) in patients who have a total laryngectomy. We wished to determine the effect of RT (initial or postoperative) specifically on the swallowing and voice function in patients treated by total laryngectomy (TL) for carcinoma of the larynx.

Design

Multicenter chart review.

Setting

Multicenter study in the Greater Manchester and Lancashire area.

Participants

A total of 121 postlaryngectomy patients all of whom had completed definitive treatment at least 6 months before this study. Twenty‐six patients had total laryngectomy as a single modality treatment and 95 had total laryngectomy and radiotherapy.

Main Outcome Measures

Swallowing (solid food, soft diet or fluid/PEG) and voice development.

Results

Swallowing was better in the group who had no radiotherapy (P = 0.0037). There was no difference in voice function between the two groups. We also demonstrated that females had a worse swallowing outcome (P = 0.0101), as did advanced nodal stage (P = 0.001).

Conclusions

RT adversely affects the swallowing results but not the speech results after TL when given either as initial treatment or postoperatively. This should be kept in mind in the decision‐making process in the treatment of patients with carcinoma of the larynx.
Same Modality nerve Reconstruction for Accessory nerve Injuries
Authors: Magill Christina K. , Moore Amy M. , Mackinnon Susan E.
Published: November 2008

The standard repair of a nerve gap under tension is to use a sensory autograft, such as the medial antebrachial cutaneous or the sural nerve. The practice of using sensory grafts to repair motor nerve defects is challenged by the discovery of preferential motor reinnervation and modality specific nerve regeneration. In this article, two clinical cases are presented where accessory nerve injuries are repaired with either a motor nerve transfer (a branch of C7) or a motor autograft (obturator nerve), and excellent functional results are reported. These cases provide a stimulus to consider the use of motor nerve grafts or transfers in the repair of motor nerve deficits.

© 2008 American Academy of Otolaryngology‐Head and Neck Surgery Foundation. All rights reserved.