bluuebunny/crossref_metadata_2025 huggingface dataset:
Short‐term transport of cadmium during a heavy‐rain event simulated by a dual‐continuum approach
Authors: Dusek Jaromir , Vogel Tomas , Lichner Lubomir , Cipakova Andrea
Published: April 2010

The transport of solutes in soils, and its intensification due to preferential flow, plays crucial role when problems related to the groundwater pollution are dealt with. The objective of this study was to examine transport of cadmium (Cd) in response to an extreme rainfall event for three different soils using numerical modeling. The 115mCd2+ concentration profile had been measured in the Bodiky reference site (Danubian Lowland, Slovakia) by the radioactive‐tracer technique and used for the calibration of the dual‐continuum model S1D. The Cd transport during a single rain event was predicted with the S1D model for light, medium‐heavy, and heavy soil in the same region. The Cd transport through the soil profile was simulated by the one‐dimensional dual‐permeability model, which assumes the existence of two pore domains: the soil‐matrix domain and the preferential‐flow domain. The model is based on Richards' equation for water flow and advection‐dispersion equation for solute transport. A modified batch technique enables to distinguish process of adsorption in the matrix domain and the preferential pathways. Modeling with classical single‐permeability approach and dual‐continuum approach without considering the particle‐facilitated transport led to negligible Cd penetration. The rainfall event with extremely high rainfall intensity induced deep penetration of Cd in the medium‐heavy and heavy soil, which may indicate increased vulnerability to shallow groundwater pollution for the respective sites in Danubian Lowland region. The highest Cd leaching was predicted for heavy clay soil, where the preferential particle‐facilitated transport of Cd through the soil profile was significant due to the contrasting properties of the soil‐matrix domain and the preferential‐flow domain. The results of the sensitivity analysis suggested only slight effect of the transfer rate coefficients on simulated Cd leaching.
The evaporation method: Extending the measurement range of soil hydraulic properties using the air‐entry pressure of the ceramic cup
Authors: Schindler Uwe , Durner Wolfgang , von Unold G. , Mueller L. , Wieland R.
Published: April 2010

Knowledge of hydraulic functions is required for various hydrological and plant‐physiological studies. The evaporation method is frequently used for the simultaneous determination of hydraulic functions of unsaturated soil samples, i.e., the water‐retention curve and hydraulic‐conductivity function. All methodic variants of the evaporation method suffer from the limitation that the hydraulic functions can only be determined to a mean tension of ≈ 60 kPa. This is caused by the limited measurement range of the tensiometers of typically 80 kPa on the dry end. We present a new, cost‐ and time‐saving approach which overcomes this restriction. Using the air‐entry pressure of the tensiometer's porous ceramic cup as additional defined tension value allows the quantification of hydraulic functions up to close to the wilting point. The procedure is described, uncertainties are discussed, and measured as well as simulated test results are presented for soil samples of various origins, different textures (sand, loam, silt, clay, and peat) and variable dry bulk density. The experimental setup followed the system HYPROP which is a commercial device with vertically aligned tensiometers that is optimized to perform evaporation measurements. During the experiment leaked water from the tensiometer interior wets the surrounding soil of the tensiometer cup and can lead to a tension retardation as shown by simulation results. This effect is negligible when the tensiometers are embedded vertically. For coarsely textured soils and horizontal tensiometer alignment, however, the retardation must be considered for data evaluation.
Comprehensive feature analysis for sample classification with comprehensive two‐dimensional LC
Authors: Reichenbach Stephen E. , Tian Xue , Tao Qingping , Stoll Dwight R. , Carr Peter W.
Published: April 2010

Comprehensive two‐dimensional LC (LC×LC) is a powerful tool for analysis of complex biological samples. With its multidimensional separation power and increased peak capacity, LC×LC generates information‐rich, but complex, chromatograms, which require advanced data analysis to produce useful information. An important analytical challenge is to classify samples on the basis of chromatographic features, e.g., to extract and utilize biomarkers indicative of health conditions, such as disease or response to therapy. This study presents a new approach to extract comprehensive non‐target chromatographic features from a set of LC×LC chromatograms for sample classification. Experimental results with urine samples indicate that the chromatographic features generated by this approach can be used to effectively classify samples. Based on the extracted features, a support vector machine successfully classified urine samples by individual, before/after procedure, and concentration with leave‐one‐out and replicate K‐fold cross‐validation. The new method for comprehensive chromatographic feature analysis of LC×LC separations provides a potentially powerful tool for classifying complex biological samples.
π‐Conjugated Donor and Donor–Acceptor Metallo‐Polymers
Authors: Wild Andreas , Schlütter Florian , Pavlov Georges M. , Friebe Christian , Festag Grit , Winter Andreas , Hager Martin D. , Cimrová Vera , Schubert Ulrich S.
Published: April 2010

Two zinc(II)‐ and two ruthenium(II) containing π‐conjugated metallo‐polymers were synthesized and characterized in detail. We could prove by SEC, analytical ultracentrifugation (AUC) and viscosimetry the ruthenium(II) metallo‐polymers to be high molar mass materials (Mfs = 20 000 g · mol−1 Ru1‐2; Mfs = 34 000 g · mol−1 Ru1) exhibiting intrinsic viscosities of up to [η] = 192 · cm3 · g−1. Applying spin‐coating we produced homogeneous films of the polymers and could, subsequently, investigate the photophysical properties in the solid state. Introducing the Ru(II) metallo‐polymers mixed with PCBM[60] as photoactive layer in bulk‐heterojunction solar cells resulted in very low efficiencies due to morphology problems.

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Poly(ferrocenylsilane) Gels and Hydrogels with Redox‐Controlled Actuation
Authors: Hempenius Mark A. , Cirmi Concetta , Savio Fabio Lo , Song Jing , Vancso G. Julius
Published: April 2010

This concise paper discusses poly(ferrocenylsilane) (PFS)‐based organometallic gels and hydrogels as a novel class of redox‐responsive materials. First, the use of silicon‐bridged spirocyclic [1]ferrocenophane crosslinkers for creating PFS networks swellable in organic solvents is described. Optical properties of PFS composite colloidal crystal films, composed of monodisperse silica spheres embedded in such PFS networks, are shown to be influenced by solvent swelling or redox chemistry, allowing the use of these composites in photonic crystal full‐color displays. The synthesis of networks composed of water‐soluble PFS polyanions or polycations is discussed. In response to redox stimuli, a polyanionic PFS‐hydrogel exerted a pressure, which could render it useful as an actuator.

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Disseminated intravascular large‐cell lymphoma with initial presentation mimicking Guillain–Barré syndrome
Authors: Jiang Qin Li , Pytel Peter , Rowin Julie
Published: April 2010

We report a patient with intravascular large B‐cell lymphoma who initially presented with acute ascending weakness and sensory changes. Electrodiagnostic testing and cerebral spinal fluid (CSF) studies were initially suggestive of a demyelinating polyneuropathy. Further clinical evaluation and testing were consistent with mononeuropathy multiplex. Autopsy revealed disseminated intravascular large‐cell lymphoma. Intravascular large‐cell lymphoma should be considered in the differential diagnosis of a rapidly evolving neuropathy associated with other organ involvement. Muscle Nerve, 2010
Geographic information systems and pharmacoepidemiology: using spatial cluster detection to monitor local patterns of prescription opioid abuse
Authors: Brownstein John S. , Green Traci C. , Cassidy Theresa A. , Butler Stephen F.
Published: April 2010

Purpose

Understanding the spatial distribution of opioid abuse at the local level may facilitate public health interventions.

Methods

Using patient‐level data from addiction treatment facilities in New Mexico from ASI‐MV® Connect, we applied geographic information system (GIS) in combination with a spatial scan statistic to generate risk maps of prescription opioid abuse and identify clusters of product‐ and compound‐specific abuse. Prescribed opioid volume data was used to determine whether identified clusters are beyond geographic differences in availability.

Results

Data on 24 452 patients residing in New Mexico were collected. Among those patients, 1779 (7.3%) reported abusing any prescription opioid (past 30 days). According to opioid type, 979 patients (4.0%) reported abuse of any hydrocodone, 1007 (4.1%) for any oxycodone, 108 (0.4%) for morphine, 507 (2.1%) for Vicodin® or generic equivalent, 390 (1.6%) for OxyContin®, and 63 (0.2%) for MS Contin® or generic equivalent. Highest rates of abuse were found in the area surrounding Albuquerque with 8.6 patients indicating abuse per 100 interviewed patients. We found clustering of abuse around Albuquerque (P = 0.001; Relative Risk = 1.35, and a radius of 146 km). At the compound level, we found that drug availability was partly responsible for clustering of prescription opioid abuse. After accounting for drug availability, we identified a second foci of Vicodin® abuse in the southern rural portion of the state near Las Cruces, NM and El Paso, Texas and bordering Mexico (RR = 2.1; P = 0.001).

Conclusions

A better understanding of local risk distribution may have implications for response strategies to future introductions of prescription opioids. Copyright © 2010 John Wiley & Sons, Ltd.
Antipsychotics and the risk of death in the elderly: an instrumental variable analysis using two preference based instruments
Authors: Pratt Nicole , Roughead Elizabeth E. , Ryan Philip , Salter Amy
Published: April 2010

Purpose

Observational studies have investigated the comparative safety of antipsychotics with varying results. Instrumental variable analysis has been suggested as a possible alternative to conventional analyses when there is concern about the effect of unmeasured confounding in observational studies. Using the example of the risk of death with typical compared to atypical antipsychotics, we aimed to explore the performance of two different instruments. We used the doctor prescribing preference instrument, which has been used in previous studies, to investigate further the assumptions of this instrument in the Australian population. We also propose an alternative instrument, nursing home facility preference.

Methods

With the Australian Department of Veterans' Affairs administrative claims database, we used an instrumental variable analysis to compare the risk of death after 12 months between the two antipsychotic classes.

Results

Using the doctor prescribing preference instrument we estimated that typical antipsychotics were associated with an extra 24 (95% Confidence Interval (CI) 18—30) deaths per 100 patients per year compared to atypical antipsychotics, and an extra 10 (95% CI 7‐14) deaths per 100 patients per year among nursing home residents. Facility prescribing preference was a stronger instrument (OR=19.2 95% CI 17.1‐21.6) and provided a better balance of covariates than doctor prescribing preference.

Conclusions

Our study has shown that valid instruments in one population may not be directly applicable to other health care settings and testing of assumptions is crucial when performing IV analyses. Facility prescribing preference appears to be a potentially valid instrument for further work in this area. Copyright © 2010 John Wiley & Sons, Ltd.
The electronic structure of chalcopyrites—bands, point defects and grain boundaries
Authors: Siebentritt Susanne , Igalson Malgorzata , Persson Clas , Lany Stephan
Published: April 2010

We summarize the progress made recently in understanding the electronic structure of chalcopyrites. New insights into the dispersion of valence and conduction band allow conclusions on the effective masses of charge carriers and their orientation dependence, which influences the transport in solar cell absorbers of different orientation. Native point defects are responsible for the doping and thus the band bending in solar cells. Results of optoelectronic defect spectroscopy are reviewed. Native defects are also the source for a number of metastabilities, which strongly affect the efficiency of solar cells. Recent theoretical findings relate these effects to the Se vacancy and the InCu antisite defect. Experimentally determined activation energies support these models. Absorbers in chalcopyrite solar cells are polycrystalline, which is only possible because of the benign character of the grain boundaries. This can be related to an unusual electronic structure of the GB. Copyright © 2010 John Wiley & Sons, Ltd.
Advanced diagnostic and control methods of processes and layers in CIGS solar cells and modules
Authors: Scheer Roland , Pérez‐Rodríguez Alejandro , Metzger Wyatt K.
Published: April 2010

Process monitoring and quality assessment for Cu(In,Ga)(Se,S)2 (CIGS) absorber layers is discussed. One focus is on laser light scattering (LLS) as a tool for process diagnostics. This technique can give in situ and real‐time information about CIGS film growth using sequential as well as evaporation processes. Raman spectroscopy is presented as a method to assess the fundamental structural properties of as‐grown films. Experience shows that the specific structure of Raman lines can be interpreted in relation to device performance. Raman spectroscopy is particularly useful for material development and achieving at least average solar cell efficiencies. Time‐resolved photoluminescence (TRPL) goes one step further and is generally related to the solar cell performance. It tracks carrier population decay after optical excitation and thus gives quantitative information about the most efficient recombination channels and material quality. It is apt to optimise the absorber of highly efficient devices. We will recommend how to use the three methods appropriately and will discuss requirements for industrial applications. Copyright © 2010 John Wiley & Sons, Ltd.
Audit of GP practice records of patients prescribed clozapine
Authors: Parker Caroline , Somasunderam Portia
Published: April 2010

Patients prescribed clozapine have associated physical health risks because of both use of the drug itself and their underlying mental illness. It is therefore important that primary and secondary care work closely together to optimise patient care. Here, the authors describe their audit of patients prescribed clozapine in secondary care to identify whether they were registered on their GP practice's severe mental illness register and whether the practice had a record that they were taking clozapine. Copyright © 2010 Wiley Interface Ltd
Cu/Ti base multicomponent amorphous Cu47Ti33Zr11Ni8Si1 and nanocrystalline silver composites
Authors: Dutkiewicz Jan , Lityńska‐Dobrzyńska Lidia , Rogal Łukasz , Maziarz Wojciech , Czeppe Tomasz
Published: April 2010

An easy glass‐forming alloy based on Cu–Ti of composition Cu47Ti33Zr11Ni8Si1 was ball milled for 40 h to obtain amorphous powder. X‐ray diffraction and differential scanning calorimetry (DSC) measurements confirmed the dominant presence of the amorphous phase after ball milling. However, transmission electron microscopy from powders allowed identification of Si particles and intermetallic phases a few nanometre in diameter, often of CuNi2Ti or Cu–Ti structures. The powder was then hot pressed in vacuum at temperature of 460 °C between the glass transition and the crystallization point to form bulk amorphous samples. Composites were prepared in the same way from mixed milled amorphous powders and nanocrystalline silver powder prepared by ball milling. Various ratios of amorphous to silver powder were applied with a maximum of 60% of nanocrystalline silver The microhardness of the amorphous phase component was near 1100 HV, much higher than the 90 HV of silver. Composites containing 20% of nanosilver have shown a much higher compression strength of 850 MPa, as compared to the 450 MPa of the composite containing 60% of silver, however, the latter has better ductility, near 5%, before fracture.
Synthesis of aluminum oxide nanoparticles using laser ablation in liquid
Authors: Kumar Bhupesh , Thareja Raj K.
Published: April 2010

We report the photoluminescence (PL) properties of aluminum oxide nanoparticles synthesized in a liquid confined ambient using pulsed laser ablation of aluminum. The colloidal suspension was dried on a quartz substrate using an IR heat lamp prior to further structural and optical characterization. TEM measurement confirms the particles of nano dimension with average size of ∼23 nm and of spherical shape. XRD measurement shows a strong peak at 31.5° indicating the presence of aluminum oxide. The PL measurement using xenon lamp as excitation source shows a broad peak. The PL peak position shifts towards longer wavelength as the excita‐ tion wavelength is changed to longer wavelengths. The shift may be due to presence of intermediate compounds like Al2O in addition to Al2O3. The appearance of luminescence bands may be associated with the defects formed in the non‐equilibrium phases and the oxygen vacancy defects which are specific features of the nanostructured state in nanostructures formed during the laser ablation inside the liquid confined ambient. A comparative study of laser ablated aluminum plasma in air and water to elucidate the various processes is also presented. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Gas suspended ZnO clusters and pulsed laser deposition of ZnO thin film
Authors: Thareja Raj K. , Mohanta Antaryami
Published: April 2010

Spectroscopic investigations are made to study the formation of oxides due to cooling of the laser ablated plasma species by collision with species of the ambient and the gas phase nanoparticles synthesis, thus providing a novel way to understand the transportation of nanoparticles and of control of particle size. A comprehensive study done on oxide films using pulsed laser deposition technique for possible laser oscillations in UV region of electromagnetic spectrum, in particular of ZnO is presented. Rayleigh scattering and photoluminescence (PL) technique are used to confirm the formation of clusters in gaseous phase. The intensity of the PL emission band increases with increase in time delays of probe pulse with respect to ablating pulse, however the intensity of Zn atomic transitions decreases. The observed emission band falls in the UV spectral region of PL of ZnO, and is attributed to excitonic recombination in ZnO clusters formed in vapor phase. The clustering of grains could be the major cause of increased surface roughness of ZnO thin films deposited by PLD at high pressure. We have deposited quality ZnO films by PLD at moderate pressure in oxygen ambient. X‐ray diffraction spectrum of film shows that grains are well oriented along c‐axis. The PL profiles of films show strong UV emission band, and weak violet and green emission band. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hybrid Ti‐ceramic bionanomaterials for medical engineering
Authors: Niespodziana K. , Jurczyk K. , Miklaszewski A. , Jurczyk M.
Published: April 2010

In the last decade a great interest has been observed in the field of nanoscale materials. Commercially pure titanium as well as titanium alloys have become predominant in implantology. Low hardness and poor tribiological properties of titanium alloys may become critical factor when wear phenomena are involved. One of the methods that allow the change of properties of Ti alloys is the production of nanocomposites, which will exhibit the favorable mechanical properties of titanium and excellent biocompatibility and bioactivity of ceramics. In this work hybrid Ti‐x wt% ceramic (45S5 Bioglass, SiO2, Al2O3) bionanocomposites (x =0, 3 and 10) were prod‐uced by the combination of mechanical alloying and powder metallurgical process. Reinforced by 45S5 Bioglass, SiO2 or Al2O3 particles, Vickers hardness of Ti‐based nanocomposite is higher from two to six times in comparison with pure microcrystalline Ti. Additionally, the experimental results show that in Ringer's solution at 37 °C, Ti‐based nanocomposites have good corrosion resistance. On the other hand, in vitro studies show that these bionanocomposites have excellent biocompatibility and could integrate with bone (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of internal energy released from nanomaterials during grain growth
Authors: Tengen T. B. , Iwankiewicz R.
Published: April 2010

The driving force for limited thermal stability of Nano‐Poly‐Crystals is high concentration of internal energy. This makes them to undergo significant changes when exposed to temperatures exceeding one‐third their melting points. Two processes are expected to take place under such temperatures which reduce the internal energy: (a) grain growth i.e. reduction in total grain boundary (GB) surface area or GB volume fraction and (b) reduction of GB energy per surface area. This paper proposes a theoretical approach that couples knowledge from energy method with that from stochastic differential equations to study the energy released from nanometals during grain growth. The basic Physics of the mechanisms leading to grain growth in nanomaterials is applied. The proposed model is tested on polycrystalline nano‐aluminium samples. The impacts of annealing time, mean grain size, grain size dispersion and annealing temperatures are tested. It is anomalously revealed that on comparing the various mechanisms of grain growth, the greatest amount of energy is released from nanomaterial if grain growth is due to Grain Rotation‐Coalescence (GRC) mechanism only, followed by that due to simultaneous GRC and Grain Boundary Migration (GBM) processes and least by that due to GBM only. The energies involved in T1 events, T2 events and in rotating the grains before coalescence during GRC have also been dealt with. On comparing the different physical activities taking place during growth, it is revealed that the largest amount of energy is released from materials in which grains rotate, translate and grow at constant force. This is followed by the amount of energy involved with rotating or translating the grains at constant size and least by the energy released due to changing grain size at constant force. It is also found that the rate of release of energy initially decreases rapidly, and then very slowly approaching zero during grain growth. Thus, one may conclude from the principle of stationary potential energy that the nanomaterial attains energy equilibrium in the long run. Thus, the driving force for grain growth at larger grain sizes is not more the grains' internal energy concentration. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase structure and crystallization of the bulk glassy FeCoZrWB alloys
Authors: Pawlik Katarzyna , Bednarcik Jozef , Pawlik Piotr , Wysłocki Jerzy J. , Kaszuwara Waldemar , Michalski Bartosz , Gębara Piotr
Published: April 2010

In the present work, the high‐energy X‐ray diffraction (XRD) measurements performed using monochromatic synchrotron radiation of 112 keV (λ=0.110696 Å), were utilized to compare a phase constitution of melt‐spun ribbon and suction‐cast rods of Fe61Co10+xZr5W4–xB20 alloys (where x = 0, 2, 3 at.%). For bulk amorphous samples of the investigated alloys DSC studies allowed to determine the activation energies of crystal growth and differences in crystallization kinetics at constant heating rates. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanocrystalline WC with non‐toxic Fe‐Mn binder
Authors: Siemiaszko Dariusz , Rosinski Marcin , Michalski Andrzej
Published: April 2010

Cemented carbides, based on the tungsten carbide (WC), are very popular and useful in an industry. The most important metal us as a binder in this kind of materials is cobalt. It has many advantages as a binder: very good wettability, favourable solubility with WC and thermal conductivity similar to WC. However, cost of cobalt is very high because of its low natural resources. Cobalt is not also neutral for health. It is known as an allergen and same research shown that it could cause a cancer. This paper presents results of sintering the tungsten carbides with Fe‐Mn alloys as the binders. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Microstructure of rapidly solidified Nd‐Fe‐Al alloys
Authors: Kaszuwara Waldemar , Michalski Bartosz , Jezierska Elżbieta , Pawlik Piotr , Leonowicz Marcin
Published: April 2010

The present work concerns the microstructure and local chemical composition of the Nd60Fe30Al10 alloy. The analyses were performed on the nanometric level (HRTEM) and completed with SEM examinations and Mössbauer spectroscopy. The specimens were in a form of 1 mm diameter rods and a rapidly solidified ribbons, prepared at a roll speed of 30 m/s. It has been shown that the alloy contains partly agglomerated nanometric size crystallites, exhibiting a crystallographic texture. The size of the crystallites depends on the quenching rate, which also influences the composition of the amorphous phase. The HRTEM studies revealed that the crystalline grains are frequently separated by a narrow layer of an intermediate phase (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of rare earth (Gd, Dy or Sm) dopants on the magnetic properties and microstructure of Nd60‐xRExFe30Al10 alloys
Authors: Michalski Bartosz , Kaszuwara Waldemar , Latuch Jerzy , Leonowicz Marcin
Published: April 2010

The effect of partial substitution of Gd, Dy and Sm for Nd in Nd60‐xRExFe30Al10 alloys for the magnetic properties and microstructure was studied. Each of the elements used has different influence on the magnetic properties of the (Nd, RE)‐Fe‐Al alloys. Gd substantially increases the coercivity, even at as high concentrations as 20%. Addition of Gd does not change neither the initial magnetization curve nor the initial susceptibility. Similarly high coercivity increase can be achieved by addition of up to 5% of Dy. For higher Dy contents a dramatic drop of the coercivity was observed. Introduction of Sm leads to deterioration of the magnetic properties, even at as small concentrations as 1%. All the additional elements studied decrease the saturation magnetization and remanence. Additions of Dy, Gd and Sm, which partly substitute Nd in the Nd60Fe30Al10 alloy, leads to formation of crystalline precipitates. In the case of Dy these precipitates are formed by MgCu2 type phase. In the Sm doped alloy the size of the crystalline precipitates, visible in the amorphous matrix, are about twice of those, which are present in the dopant free alloy. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of semipolar (10$ \bar 1\bar 3 $) InN on m ‐plane sapphire using MOVPE
Authors: Dinh Duc V. , Pristovsek M. , Kremzow R. , Kneissl M.
Published: April 2010

We report on the growth of semi‐polar InN directly on m ‐plane sapphires by metal‐organic vapor phase epitaxy with different nitridation times from 45 s to 6 min. Surface morphology and crystalline orientation depended on the nitridation time. Semipolar InN with (10$ \bar 1\bar 3 $) dominant orientation was obtained at 2 min and 4 min nitridation, shorter or longer nitridation times showed additional orientations. The (10$ \bar 1\bar 3 $) InN has a roughness about 30 nm (scale size 5 × 5 µm2), likely due to twinning. Low temperature photoluminescence showed emission peaks between 0.72 eV to 0.75 eV, which is slightly below the energy observed for (0001) InN. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient light trapping in a fluorescence solar collector by 3D photonic crystal
Authors: Knabe Sebastian , Soleimani Nazila , Markvart Tom , Bauer Gottfried Heinrich
Published: April 2010

The escape of photons from a fluorescence collector is substantially reduced by the addition of a 3D photonic crystal which is geometrically designed for the emission wavelengths of the collector. We analyze angle dependent spectral transmission and reflection of the opal and prove the blocking effect by recording the angle dependence of the spectral fluorescence from the collector with and without the opal. By comparison of both photon fluxes a reduction of the emission in the appropriate ranges of wavelength and angle by a factor >10 is observed. For photovoltaic applications an increase in the internal photon density of the collector and likewise in the fluorescence photon flux fed to a solar cell can be expected, which might be overcompensated by the non‐negligible reflection of the opal. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The major product ion of S‐adenosyl‐L‐methionine arises from a neighbouring group reaction
Authors: Barnett Zoe Mein‐Ee , Feketeová Linda , O'Hair Richard A. J.
Published: April 2010

Previous studies have shown that low‐energy collision‐induced dissociation (CID) of the important sulfonium ion metabolite S‐adenosyl‐L‐methionine (AdoMet, m/z 399) yields five main product ions: an ion at m/z 250 arising from methionine loss; ions at m/z 102 and 298, which arise via cleavage of the γ CS bond of methionine; and ions at m/z 136 and 264, which arise via loss of protonated and neutral adenine, respectively. These metabolomics studies have, however, either totally ignored the mechanisms that govern the formation of the major product ion at m/z 250 (Gellekink H, van Oppenraaij‐Emmerzaal D, van Rooij A, Struys EA, den Heijer M, Blom HJ. Clin. Chem. 2005; 51: 1487), or have proposed an oxonium ion structure that must arise via a rearrangement involving a 1,2 hydride shift (Cataldi TRI, Bianco G, Abate S, Mattia D. Rapid Commun. Mass Spectrom. 2009; 23: 3465). Here DFT calculations on a model system are used to examine potential mechanisms for the formation of the major product ion of AdoMet. These calculations suggest that a neighbouring group mechanism is preferred over a 1,2 hydride shift mechanism. Copyright © 2010 John Wiley & Sons, Ltd.
Structural elucidation of biologically active neomycin N‐octyl derivatives in a regioisomeric mixture by means of liquid chromatography/ion trap time‐of‐flight mass spectrometry
Authors: Giera Martin , de Vlieger Jon S. B. , Lingeman Henk , Irth Hubertus , Niessen Wilfried M. A.
Published: April 2010

Structural elucidation of six regioisomers of mono‐N‐octyl derivatized neomycin is achieved using MSn (up to n = 4) on an ion trap time‐of‐flight (IT‐TOF) instrument equipped with electrospray ionization. The mixture of six derivatized neomycin analogues was generated by reductive amination in a shotgun synthetic approach. In parallel to the liquid chromatography/mass spectrometry (LC/MS) detection, the antibacterial activity of the neomycin regioisomers was tested by post‐column addition of buffer and bacterial inocula, subsequent microfractionation of the resulting mixture, incubation, and finally a chemiluminescence‐based bioactivity measurement based on the production of bacterial ATP. The MS‐based high‐resolution screening approach described can be applied in medicinal chemistry to help in designing and producing new antibiotic substances, which is particularly challenging due to the high functionality of most antibiotic substances, therefore requiring advanced (hyphenated) separation and detection techniques for compound mixtures. Copyright © 2010 John Wiley & Sons, Ltd.
A nuclear magnetic resonance (1H and 13C) and isotope ratio mass spectrometry (δ13C, δ2H and δ18O) study of Andalusian olive oils
Authors: Aramendía María A. , Marinas Alberto , Marinas José M , Sánchez Elena , Urbano Francisco J. , Guillou Claude , Moreno Rojas José M. , Moalem Mustafa , Rallo Luis
Published: April 2010

We have determined δ13C, δ2H and δ18O isotopic abundances in Andalusian olive oils. In addition, the fatty acid composition and the distribution of isomers at positions 1,3 and 2 of glycerol were determined by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, respectively. Isotopic results obtained for four series of oil samples extracted from olives harvested in the 2004/05 and 2005/06 seasons are discussed in terms of olive variety, ripeness, geographical origin, fatty acid composition and growing altitude. A distinction was also established between olives grown in irrigated and in dry land by studying selected samples of the previous series and others from the 2005/06, 2006/07, 2007/08 and 2008/09 seasons. The results showed that olive ripeness does not influence the abundance of any of the three isotopes studied. On the other hand, the olive variety influences the abundance of the oxygen and hydrogen isotopes, and also, less markedly, that of carbon. No clear‐cut effect of height or latitude on isotope values is observed, probably because the olive variety also changes with height and latitude, thus masking such influences. The oil samples from dryland‐grown olives had increased δ13C values relative to irrigation‐grown olives. In addition, no definite relationship appears to exist between isotope distribution and fatty acid composition. Finally, oil samples from olives harvested in the 2005/06 season in Italy could be distinguished from those from Spain in terms of their isotopic values (δ2H mainly). Copyright © 2010 John Wiley & Sons, Ltd.
Teacher thinking associated with science‐specific mentor preparation
Authors: Koballa Thomas R. , Kittleson Julie , Bradbury Leslie U. , Dias Michael J.
Published: April 2010

Framed by sociocultural theory, the purpose of the study was to understand the cultural tools used by science teachers when leaning to mentor and how tool use may lead to the construction of new understandings about mentoring. The participants were 37 experienced teachers enrolled in a federally funded science‐specific mentor preparation program. Data took the form of interview transcripts, electronic bulletin board postings, and written cases. Program participants were found to use a range of tools to mediate their thinking about science teacher mentoring. Analysis of data revealed that the participants used the discourse of science teaching as well as such tools as classroom observation strategies and interpersonal mentoring approaches, to mediate their thinking about mentoring. The participants' tools also included images that mediated their responses to specific mentoring challenges and dilemmas that highlighted for them contradictions in their thinking about mentoring. The cultural tools used by the science teachers when learning to mentor provide insight into how they think about science teacher mentoring and the nature of the professional learning experiences needed to enable them to develop as mentors. © 2010 Wiley Periodicals, Inc. Sci Ed 94:1072–1091, 2010
Neutral cesium deposition prior to SIMS analysis of inorganic and organic samples
Authors: Philipp P. , Audinot J‐N. , Wirtz T. , Migeon H‐N.
Published: April 2010

The enhancement of negative secondary ions yields in SIMS by the use of electropositive primary ions is well known. In previous papers, the authors of this article have reported on the simultaneous use of primary ion bombardment coupled with neutral cesium deposition to optimize the useful yields of negative secondary ions in the steady‐state regime. For electronegative elements, total ionization was achieved while the gain for the other elements attained two orders of magnitude. In this paper, we study the enhancement of negative secondary ion yields in the pre‐equilibrium regime by depositing neutral cesium onto the sample surface prior to the SIMS analysis. The main areas of application of this technique lie in the field of secondary ion imaging of sample surfaces. Of particular interest is the analysis of organic and biological samples on the Cameca NanoSIMS50 instrument. Both inorganic and organic samples will be investigated in this paper. Copyright © 2010 John Wiley & Sons, Ltd.
Impaired Hippocampal Neurogenesis and Vascular Formation in Ephrin-A5-Deficient Mice
Authors: Hara Yoshinobu , Nomura Tadashi , Yoshizaki Kaichi , Frisén Jonas , Osumi Noriko
Published: April 2010

Neurogenesis occurs throughout the life in the mammalian brain. The hippocampal dentate gyrus (DG) is one of the major regions of the adult neurogenesis, where neural stem/progenitor cells continuously generate new granule neurons, although molecular mechanisms underlying generation and maintenance of newly born neurons are still elusive. Here we show that ephrin-A5, a ligand for Eph receptor tyrosine kinases, plays multiple roles in both neurogenesis and vascular formation in the adult hippocampus. In mice lacking ephrin-A5 function, cell proliferation and survival of newborn neurons were severely reduced in the hippocampus DG. Furthermore, ephrin-A5-deficient mice exhibited altered distribution of EphA4 receptor in the vascular endothelial cells and increased narrower capillaries in the hippocampus DG. EphA/ephrin-A signaling thus plays crucial roles in the establishment and/or maintenance of the brain vascular system, as an essential constituent of the adult neurogenic niche.
A Role for Borg5 During Trophectoderm Differentiation
Authors: Vong Queenie P. , Liu Zhonghua , Yoo Jae Gyu , Chen Rong , Xie Wen , Sharov Alexei A. , Fan Chen-Ming , Liu Chengyu , Ko Minoru S.H. , Zheng Yixian
Published: April 2010

Stem cell differentiation is accompanied by a gradual cellular morphogenesis and transcriptional changes. Identification of morphological regulators that control cell behavior during differentiation could shed light on how cell morphogenesis is coupled to transcriptional changes during development. By analyzing cellular behavior during differentiation of mouse embryonic stem cells (ESCs), we uncover a role of Borg5 (binder of Rho guanosine 5′-triphosphatase 5) in regulating trophectoderm (TE) cell morphogenesis. We report that differentiation of ESCs toward TE is accompanied by enhanced actin protrusion and cell motility that require upregulation of Borg5. Borg5 interacts with both Cdc42 and atypical protein kinase C (aPKC) and functions downstream of Cdc42 to enhance TE cell motility. Borg5 is required for the sorting of differentiating TE to the outside of ESCs in vitro. In developing embryos, Borg5 protein localizes to cell–cell contacts and the cytoplasm after compaction. It exhibits higher levels of expression in outer cells than in inner cells in morula and blastocysts. Reduction of Borg5 disrupts aPKC localization and inhibits blastocyst formation. Since Cdx2 and Borg5 facilitate each other's expression as ESCs differentiate toward TE, we propose that cell morphogenesis is coupled with transcriptional changes to regulate TE differentiation. Our studies also demonstrate the utility of ESCs in identifying morphological regulators important for development.
Optical coherence tomography as a non‐invasive imaging technique for preinvasive and invasive neoplasia of the uterine cervix
Authors: Gallwas J. , Turk L. , Friese K. , Dannecker C.
Published: April 2010

Objective

Optical coherence tomography (OCT) is a non‐invasive high‐resolution imaging technique that permits characterization of microarchitectural features of tissue up to 2 mm in depth in real time. The purpose of this study was to evaluate the feasibility of OCT for the identification of precancerous (cervical intraepithelial neoplasia (CIN)) and cancerous lesions of the uterine cervix.

Methods

We conducted a prospective study on the use of OCT in women with suspected CIN. OCT images were obtained on colposcopy from non‐suspicious and suspicious areas, and were evaluated independently by two investigators and later compared with the corresponding histology. The sensitivity, specificity, negative and positive predictive values and accuracy of the new technique in identifying CIN or carcinoma were calculated.

Results

Of a total of 610 OCT images, 97 from suspicious areas in 60 women were compared with the corresponding histology. Sixty‐three of 67 CIN lesions and four invasive carcinomas were diagnosed correctly on evaluation of the OCT images by the first observer. There were 69 true‐positive, 11 true‐negative, 13 false‐positive and four false‐negative results, giving a sensitivity of 95% and a specificity of 46%.

Conclusion

OCT is a rapid, easy‐to‐use modality that provides real‐time, microarchitectural information of the cervical epithelium. Further refinement of this technology will lead to OCT systems with a significantly higher resolution and may result in better differentiation of cancerous and precancerous lesions. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
Sequence design for MPG QS‐CDMA systems based on heuristic combinatorial optimization
Authors: Kuramoto André S. R. , Ciriaco Fernando , Abrão Taufik , Jeszensky Paul Jean E.
Published: April 2010

This paper deals with a quasi‐synchronous code division multiple access (QS‐CDMA) system with a multiple processing gain (MPG) variable data rate scheme in the uplink direction and subject to multipath fading channels. An analytic expression is obtained for the signal‐to‐noise plus interference ratio (SNIR) at the Rake receiver output (finger). In order to maximize the SNIR, three combinatorial optimization methods applied to sequences selection are compared. Then, sequence selection methodology for this class of system is evaluated, comparing the local search optimization results with unitary Hamming distance (1‐opt LS), evolutionary programming with cloning (EP‐C), and simulated annealing (SA) ones. The contribution of this work consists of considering the self‐interference (SI) effect, besides the multiple access interference (MAI), in the description of the proposed objective function for sequence selection and a compared analysis of three heuristic algorithms maximizing that SNIR. Also, numeric results have demonstrated the effectiveness of the proposed method for the QS‐CDMA sequences selection. Copyright © 2010 John Wiley & Sons, Ltd.
The digital forensics of portable electronic communication devices based on a Skype IM session of a pocket PC for NGC
Authors: Chu Hai‐Cheng , Deng Der‐Jiunn , Chao Han‐Chieh
Published: April 2010

Portable electronic communication devices can be used for many purposes and they are capable of integrating with ubiquitous computing (UC) infrastructures to carry on mobile multimedia communications. As those devices become prevalent, they incur potential network security threatening to organizations. Nowadays, the Skype is the most popular P2P VoIP application program, which is being used by millions of global users to place IP phone calls, transfer files, or communicate via instant messaging (IM). This phenomenon already generates imminent network security issues that are indispensable to digital forensics researchers or the law enforcement agencies worldwide. Cellular phones, smart phones, and personal digital assistants (PDAs) are the representative ones of those devices and there are some open sources or commercial software toolkits that can be utilized to proceed the forensics investigation concerning the electronic crimes in next generation communications (NGCs). A case review was conducted to illustrate the hidden digital trails within the PDA from the Registry of the Windows Mobile and volatile data in the RAM to discover the possible network security leakage scenarios that resulted in the vandalism of intangible digital assets of the organization. Copyright © 2010 John Wiley & Sons, Ltd.
Fuzzy set theory
Authors: Zimmermann H.‐J.
Published: April 2010

Since its inception in 1965, the theory of fuzzy sets has advanced in a variety of ways and in many disciplines. Applications of this theory can be found, for example, in artificial intelligence, computer science, medicine, control engineering, decision theory, expert systems, logic, management science, operations research, pattern recognition, and robotics. Mathematical developments have advanced to a very high standard and are still forthcoming to day. In this review, the basic mathematical framework of fuzzy set theory will be described, as well as the most important applications of this theory to other theories and techniques. Since 1992 fuzzy set theory, the theory of neural nets and the area of evolutionary programming have become known under the name of ‘computational intelligence’ or ‘soft computing’. The relationship between these areas has naturally become particularly close. In this review, however, we will focus primarily on fuzzy set theory. Applications of fuzzy set theory to real problems are abound. Some references will be given. To describe even a part of them would certainly exceed the scope of this review. Copyright © 2010 John Wiley & Sons, Inc.

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Clustering and Classification
Historical Evolution of Thyroid Surgery: From the Ancient Times to the Dawn of the 21st Century
Authors: Sakorafas George H.
Published: April 2010

Thyroid diseases (mainly goiter) have been recognized for more than 3500 years. Knowledge of the nature of these diseases was, of course, limited at that time. Thyroid surgery was conceived by the ancients, but it was limited to rare attempts to remove part of an enlarged thyroid gland in cases of impending death by suffocation or, in very rare cases, of a suppurating thyroid. Like other fields of surgery, thyroid surgery was limited by many problems: the lack of anesthesia and antisepsis, the need for appropriate instruments, mainly artery forceps (many deaths after thyroid surgery were due to severe postoperative hemorrhage or infection). Much of the progress in thyroid surgery occurred in Europe during the second half of the 19th century. During the first half of the 20th century, the evolution of thyroid surgery accelerated significantly, based on the contributions of pioneering European and American surgeons. The present status of thyroid surgery was established during the last quarter of the 20th century, when modern imaging methods and technological advances (including progress in applied molecular biology) brought thyroid surgery into the new millennium.