bluuebunny/crossref_metadata_2025 huggingface dataset:
Ab Initio Study of Electronic and Magnetic Properties of GaSb/Mn and GaAs/Mn Digital Ferromagnetic Heterostructures
Authors: Titov A. , Kulatov E.T. , Uspenskii Y.A. , Tugushev V.V. , Michelini F. , Mariette H.
Published: September 2009

Electronic and magnetic properties of GaSb/Mn and GaAs/Mn digital heterostructures were studied using the augmented plane wave method. The calculated electronic structures of GaSb/Mn and GaAs/Mn are similar. A pre-edge absorption line at 6541 eV should be observed in Mn K-edge x-ray absorption spectra of the heterostructures. This line can be used to study the spatial distribution of Mn in layers. The energy of exchange interaction between two Mn layers was calculated as a function of interlayer separation. Different dependencies of the exchange energy are found for GaSb/Mn and GaAs/Mn heterostructures.
A Fluctuating Field Theory for Systems of Localized Magnetic Moments
Authors: Grebennikov Vladimir I.
Published: September 2009

Thermodynamics of Heisenberg ferromagnets is described by means of a fluctuating exchange field operating on the atomic magnetic moments. A self-consistent method for calculating field characteristics is developed at arbitrary temperatures. It is shown that transitions in a paramagnetic state may pass both continuously and stepwise on temperature subject to magnitude of single-site susceptibility.
Investigation of the Critical Properties in the 3D Site-Diluted Potts Model
Authors: Murtazaev Akai K. , Babaev A.B. , Aznaurova G.Ya.
Published: September 2009

The effect of quenched nonmagnetic impurities on phase transitions in the three-dimensional Potts model with the number of spin states q=3 is studied using the Wolff single-cluster algorithm of the Monte Carlo method. By the method of fourth-order Binder cumulants, it is demonstrated that the second-order phase transition occurs in the model under study at spin concentrations p=0.9, 0.8, 0.7, and 0.65, while the first-order phase transition is observed in the pure model (p=1.0). The static critical exponents (CEs) α (heat capacity), γ (susceptibility), β (magnetization), and ν (correlation length) are calculated based on the finite-size scaling theory.
Magnetic Properties of RFe9Ti Single Crystals with ThMn12 Structure
Authors: Skokov Konstantin , Pastushenkov Yury G. , Semenova E.M. , Bartolomé Juan
Published: September 2009

A comparative analysis of the magnetic properties of RFe11Ti and RFe9Ti single crystals (R=Ho,Er) with ThMn12 structure was carried out. It is shown that the decrease of iron content causes a 10% decrease in the saturation magnetization and a reduction by 10-15K in the Curie temperature. Besides, field induced spin reorientation appears at about 60 kOe in RFe9Ti, while in HoFe9Ti the First Order Magnetization Process transition field increases by 10 kOe with respect to the corresponding RFe11Ti compound.
Microstructure Evolution upon Thermomagnetic Treatment of Soft Magnetic Alloys
Authors: Gubernatorov V.V. , Sycheva T.S. , Kositsyna Irina I.
Published: September 2009

A new concept is suggested that serves to explain the effects of thermomagnetic treatment. Its validity is proved via measurements of magnetic properties and electron microscopy examination of structure of soft magnetic materials after different treatments. This concept allows one to consciously choose the treatment mode aiming on improvement of magnetic properties of alloys.
Effects of Heat Treatment Conditions on Magnetic Properties and Structural Features of Nanocrystalline Fe79Zr10N11 Films
Authors: Sheftel E.N. , Iskhakov Rauf S. , Komogortsev S.V. , Sidorenko P.K. , Perov Nikolai S.
Published: September 2009

Data on the random magnetic anisotropy and exchange correlation length in soft magnetic nanocrystalline Fe79Zr10N11 films were obtained using a calculation technique in frame of the random magnetic anisotropy model. The calculations are performed using approach magnetization to saturation curves. The local magnetic anisotropy fields (Ha), and magnetic anisotropy correlation radii (Rс) reduced to =(A/K)1/2 were determined for the films annealed at 475 and 6000 C for 0.5, 1, 2, and 3 h. The correlation Hc ~(Rc/)3 for the all annealed films was found.
Glass-Coated Cu-Mn-Ga Microwires Produced by Taylor-Ulitovsky Technique
Authors: Suñol Joan Josep , Escoda L. , García C. , Prida V.M. , Vega Victor , Sánchez M.L. , Sánchez Llamazares José Luis , Hernando B.
Published: September 2009

Glass-coated Cu-Mn-Ga microwires were fabricated by Taylor-Ulitovsky technique. By means of energy dispersive spectroscopy microanalysis, an average alloy composition of Cu56Ga28Mn16 was determined. The temperature dependence of magnetization measured at a low magnetic field showed the coexistence of two ferromagnetic phases. The Curie temperature of one phase is 125 K and above room temperature for the other one. X-ray diffraction at room temperature and at 100 K reflects the presence of the same three crystalline phases corresponding to the cubic B2 Cu-Mn-Ga structure as a main phase and the minor phases of fcc Cu rich solid solution with Mn and Ga and the monoclinic CuO.
Electronic and Magnetic States of Iron Ions in (Bi1-xSrx)FeO3-y Multiferroic Perovskites
Authors: Cherepanov V. M. , Pokatilov V. S.
Published: September 2009

The mixed perovskites (Bi1-xSrx)FeO3-y (x = 0.07, 0.14, 0.25 and 0.50) were studied by 57Fe Mössbauer spectroscopy in the temperature range 87–700 K. The samples were prepared by conventional ceramic technology with 10% 57Fe isotope enrichment. X–ray diffraction measurements showed that the samples were single-phase and had a rhombohedral structure at x = 0.07 and a cubic one at x = 0.14-0.50. As the strontium content x increases, the Neel temperature TN(x) increases from 640 K (x = 0) to 670 K (x = 0.25) and then decreases to 637 K (x = 0.5). The similar dependence on x was found for the hyperfine field values B(x) at T = 87 K. The experimental Mössbauer spectra are satisfactorily described by three to four Fe3+ states with the room temperature isomer shift values in the range 0.17-0.43 mm/s, which correspond to the iron sites with 4, 5 and 6 oxygen neighbours.
57Fe Hyperfine Parameters in Bi1-xLaхFeO3 (x = 0 - 1)
Authors: Pokatilov V.V. , Pokatilov V. S.
Published: September 2009

57Fe Mössbauer study of the Bi1-xLaxFeO3 (х=0, 0.1, 0.2, 0.61, 0.9, 1.0) perovskites has been performed at room temperature (RT) to analyze influence of the space spin-modulated magnetic structure (SSMMS) on parameters of hyperfine interactions, the valence and magnetic states of iron ions. SSMMS in perovskites BiFeO3 and Bi0.9La0.1FeO3 leads to a specific distribution of hyperfine fields P(H) with two peaks. Substitution La for Bi more than х = 0.2 destroys SSMMS and P(H) corresponds to a distribution for a homogeneous spin structure. Concentration dependences of hyperfine fields (H), isomer (δ) and quadrupole (ε) shifts were measured. Due to the isomer shift values the iron ions are in the trivalent state. The local magnetic moments μ(Fe) on Fe+3 ions were determined in these perovskites.
Nano-Silicon Sol-Gel Film Refraction Index Modulation with Femtosecond Laser
Authors: Dima Antonela , Gagliardi Massimo , Liu Dun , Perrie Walter , Williams Craig J. , Rendina Ivo , Dearden Geoff , Watkins Ken G.
Published: September 2009

Patterned structures were created by exposing SiO2 sol-gel films containing nano-silicon particles to a Clark MXR CPA-2010 fs laser (387 nm). A refractive index variation of 0.2 was obtained, similar to that of polymer films, however in an entirely superior stability class (structural, chemical, thermal, radiation, etc). The useful optical range of refractive index modulation is beyond 800 nm, respectively near-IR. Material characteristics were investigated with atomic force microscopy (AFM), Raman spectroscopy and spectro-ellipsometry measurements. Material properties were also investigated on different substrates in order to determine the influence of substrate type in laser processing.
Urethane Magnetorheological Elastomers - Manufacturing, Microstructure and Properties
Authors: Boczkowska Anna , Awietjan Stefan F.
Published: September 2009

In this paper studies on urethane magnetorheological elastomers (MREs) microstructure in respect to their magnetic and mechanical properties are reported. MREs were obtained from a mixture of polyurethane gel and carbonyl-iron particles cured in a magnetic field of 100 and 300 mT. The amount of particles was varied from 1.5 to 33 vol. %. Samples with different arrangements of particles were produced. Effect of the amount of ferromagnetic particles and their arrangement on microstructure and properties in relation to the external magnetic field was investigated. The microstructure was studied using scanning electron microscopy. Magnetic properties were measured using vibrating sample magnetometer. Rheological and mechanical properties under compression were also examined.
Elastomers Containing Fillers with Magnetic Properties
Authors: Zaborski Marian , Pietrasik Joanna , Masłowski Marcin
Published: September 2009

Composites of rubbers such as ethylene – propylene and acrylonitrile – butadiene with micro size Fe¬3O4, Fe2O3, and nano size Fe3O4 as the fillers were tested. Iron oxides were found to be active fillers which improved mechanical properties of elastomers. Additionally, they also changed their magnetic properties. Furthermore, the surface of micro size Fe3O4 was modified to upgrade mechanical properties of the vulcanizates. Itaconic acid, methacryloxypropyltrimethoxysilane and monododecyl maleate were used as modifying agents. To improve dispersion of applied fillers in polymers matrix, non-ionic (NF-PEG), anionic (calcium stearate ), cationic (DTAB, DTAC, DDAB, CTAD) and ionic liquids (HMIMBF4, BMIMPF6, OMIMPF6) were used. It was observed that both non-modified and modified micro iron oxides and nano iron oxides improved the properties of the vulcanizates the most effectively.
Texture Analysis of Hot Rolled Ni-Mn-Ga Alloys
Authors: Morawiec Henryk , Goryczka Tomasz , Drdzeń Andrzej , Lelątko Józef , Prusik Krystian
Published: September 2009

The studies were carried out on three Ni-Mn-Ga polycrystalline alloys with the 10M martensite and the L21 parent phase. The specimens were cut along the [001] and [110] directions of the columnar grains from the ingots of either round or flat shape. The samples were heated up to 10000C and rolled in one direction in several steps. The final reduction of the samples thickness was: 28%, 36%, 57% and 69%. The texture of the initial [001] orientation rolled with the highest deformation 60% shows the following orientation components: {111}<112>, {112}<011>, {111}<011> which are typical for deformed and recrystallized metals of the A2 structure. The texture of the specimen with the initial [110] orientation rolled with 69% can be described as a fibre texture scattered around the <110> direction.
Microstructure and Magnetic Properties of Two Phase β+γ Ferromagnetic Co-Ni-Al Alloys
Authors: Maziarz Wojciech , Dutkiewicz Jan , Wróblewski Rafał , Leonowicz Marcin
Published: September 2009

The microstructure, texture and magnetic properties of two ferromagnetic alloys of composition Co35Ni37Al28 and Co37Ni35Al28 (in at. %) were investigated with optical microscopy (OM), analytical transmission electron microscopy (TEM), scanning electron microscopy (SEM) techniques as well as a vibrating sample magnetometer (VSM). The alloys were plastically deformed and heat treated in order to promote the martensitic transformation. Differential scanning calorimetry (DSC) revealed a drop of Ms temperature due to the increase of Co content in the alloys. The elongated twinned grains of size about 200 m and small precipitates of  phase were identified with the OM techniques. The TEM observations showed the twinned L10 non modulated martensite within the elongated grains and a small amount of ordered ’ phase after the heat treatment. The chemical composition of different martensite grains was established using point analyses of a HAADF-EDS technique. The magnetic phase transition temperatures were determined on the deformed samples using VSM method.
Effect of Annealing Conditions on the Structure of Ni50Mn29Ga21 Shape Memory Alloy
Authors: Wróblewski Rafał , Leonowicz Marcin
Published: September 2009

Effect of annealing conditions on the structure and phase transition temperatures for polycrystalline Ni50Mn29Ga21 alloy was studied. The final structure strongly depends on the annealing temperature and cooling rate. Ordering of the austenitic phase, performed by annealing at elevated temperatures, plays an important role in formation of the proper martensitic structure. For the Ni50Mn29Ga21 alloy annealing below the ordering temperature (1033 K) forms 5M modulated martensitic structure, irrespective of the cooling rate. The 7M modulated martensitic structure can be produced after annealing above the ordering temperature, followed by slow cooling.
Field Dependence of the Refrigerant Capacity for La0.6Ca0.4MnO3 Manganite
Authors: Szymczak R.A. , Kolano-Burian Aleksandra , Kolano Roman , Puzniak R. , Dyakonov V.P. , Zubov E.E. , Iesenchuk Oleksii , Szymczak H.
Published: September 2009

The magnetocaloric effect in La0.6Ca0.4MnO3 manganite has been investigated. The isothermal magnetization versus applied magnetic field at various temperatures in the vicinity of Curie temperature was measured, and the temperature dependence of magnetic entropy change was determined using Maxwell’s relation. This value is comparable to that in Gd. Nevertheless, the relative cooling power of La0.6Ca0.4MnO3 was shown to be considerably lower than that of Gd. The experimental results have been analyzed in frames of a phenomenological statistical model. This model considers explicitly Jahn-Teller interactions and allows prediction of the field dependences of the magnetic entropy change and the relative cooling power.
Magnetic Anisotropy of Nanocrystalline HITPERM-Type Alloys and its Correlation with Application
Authors: Ferenc Jarosław , Kowalczyk Maciej , Erenc-Sędziak Tatiana , Liang Xiu Bing , Vlasák Gabriel , Kulik Tadeusz
Published: September 2009

Structure as well as magnetic and magnetoelastic properties of nanocrystalline (Fe,Co)-(Hf,Zr)-Cu-B alloys (HITPERM-type) were investigated in order to find out which factors are responsible for the magnetic hardening of these magnetically soft materials. Magnetoelastic anisotropy, caused by the presence of cobalt, was found to play the predominant role in the observed increase of coercive field. On this basis, guidelines on chemical composition and crystallisation process selection were suggested for two fields of application: soft magnetic cores and sensors or actuators cores.
Kinetics of Swelling and Drug Release from PNIPAAm/Alginate Stimuli Responsive Hydrogels
Authors: Dumitriu Raluca Petronela , Oprea Ana Maria , Vasile Cornelia
Published: September 2009

Stimuli responsive hydrogels are very attractive for applications in sustained and/or targeted drug delivery systems. As the release of drugs is related to the swelling behavior of hydrogels, the swelling kinetic studies become of great importance to appreciate the release kinetics from hydrogel matrices. Hydrogels with high performance properties have been prepared from N-isopropylacryl amide (NIPAAm) and sodium alginate, crosslinked with N,N`-methylene-bis-(acrylamide) (MBAAm). This study is focused on the investigation of swelling and drug release kinetics, coupled by morphological studies. The kinetic parameters of the swelling at different temperatures for hydrogels samples have been evaluated and confirmed their temperature-responsive behavior. The swelling rate constant (ksw) decreases of with increasing temperature and slight increases with the alginate content in the samples. The drug release kinetic study from the prepared hydrogel matrices was performed in twice-distilled water and ethanol for bioactive agents as vanillin and ketoprofen, respectively. An increase of alginate content results in a slower rate and smaller percentage of vanillin and ketoprofen released. It has been established that the ketoprofen occurs according with case II of transport and vanillin release behavior occurs by an anomalous transport mechanism. The values of the release rate constant (kr) decreased by increasing swelling degree in case of 75/25 NIPAAm/alginate hydrogels and decreased also by increasing content of alginate in hydrogels with various compositions. Morphological studies performed by environmental scanning electron microscopy (ESEM) evidenced a relaxed network at high relative humidity, which explain both swelling and release profiles.
3D Magnetovision Scanner as a Tool for Investigation of Magnetomechanical Principles
Authors: Kaleta Jerzy , Lewandowski Daniel , Wiewiórski P.
Published: September 2009

The study was aimed at designing a system for measuring the distribution of magnetic field around different magnetic objects including Smart Magnetic Materials. A new type of 3D camera for monitoring the magnetic field intensity was constructed. The measurement principle is based on internal magnetics properties of materials and the reverse magnetostriction effect (also called the Villari effect). No external magnetizing field is assumed; the entire magnetic effect is due to magnetomechanical principles. A new generation of Honeywell magnetosensors were applied to measure field intensity in 3D. Small size of measurement area (1.5 mm3) allows quasi-local measurement of magnetic field. In the measurement head also Hall probes were alternately used. The aim of this stage of research was to construct the set for measurement of strength of a very weak magnetic field (10 A/m) around the magnetic objects. In scanner construction three axes for displacement in directions consistent with sensor axis were applied, which permits measuring magnetic field vector in geometrical coordination. Specialized software for data acquisition, processing and visualization of magnetic field vector has been written. In preliminary parts of the work magnetic scanner system allows determination of correspondence between mechanical and magnetic quantities. Main applications for this type of system are: reverse magnetostriction and magnetostriction in smart magnetic materials and composites, martensitic transformation induces plastic strain in shape memory alloys, NDT investigation, identification of local plastic deformation and texture of ferromagnetic materials, magnetic polygraphy and others. Measuring system may be used both as an entirely autonomous system as well as an integrated one, also through joint control with a typical mechanical testing systems for static and fatigue tests.
Active Control of Landing Gear Shock Absorber Characteristic Using Magnetoreological Fluids
Authors: Skorupka Zbigniew , Kajka R. , Harla R. , Kowalski W. , Parafiniak M. , Kacprzak M. , Balcerkiewicz G. , Pacholski J. , Lechniak W.
Published: September 2009

Smart materials are being used in much larger scale in mechanical solutions. Aviation usage of these materials seems to be natural because of interest in new technologies use in this industry. In this article authors discuss characteristics of magnetoreological fluids as a smart materials, examples of its industrial usage, requirements on landing gear characteristics, design and lab tests of model shock absorber in which MRF was used as damping fluid.
Performance of Shape Memory Composite with SMA and SMP
Authors: Tobushi Hisaaki , Hayashi Shunichi , Sugimoto Y. , Date K.
Published: September 2009

The shape-memory composite belt with a TiNi-SMA wire fiber and a polyurethane-SMP sheet matrix was fabricated. The bending actuation characteristics of the belt were investigated by the thermomechanical tests. Residual deflection obtained by cooling under constant maximum deflection is close to the maximum deflection. The residual deflection disappears by heating under no load. Both the rates of shape fixity and shape recovery are close to 100%. Recovery force which appears by heating under constant residual deflection is 93-94% of the maximum force. The model of bending-spring constant of the shape-memory composite belt is proposed and evaluated based on the experimental data.
Shape Memory Assemblies Using Ultrasonic Welding
Authors: Crăciunescu Corneliu Marius , Oanca Octavian , Dehelean Dorin
Published: September 2009

The paper describes the research developed in order to assemble shape memory alloys using welding technologies with the aim to reduce the heat affected zone. It is shown that ultrasonic welding can be solutions that could be considered for this purpose. Experiments on welding shape memory alloys have been performed on bulk and rapid solidified ribbons and the interface has been characterized using microstructural observations. The investigations show the difficulties in assembling microfabricated shape memory ribbons with conventional sonotrode/anvil solutions due to the limited thickness of the ribbons and the need to develop microstriations on the surface of the ultrasonic welding tools. It is however considered that ultrasonic welding can be a solution for joining shape memory alloys in similar or dissimilar architectures.
Simultaneous Growth of MWCNTs at Different Temperatures in a Variable Gradient Furnace
Authors: Grossi Valentina , Urbani Ale , Giugni Andrea , Cantalini C. , Santucci Sandro , Passacantando Maurizio
Published: September 2009

Multi-walled carbon nanotubes (MWCNTs) have been grown, simultaneously at different temperatures (600 °C, 700 °C, 725 °C, and 750 °C), by thermal chemical vapour deposition (CVD) of acetylene (C2H2) gas, in ammonia (NH3) atmosphere. The samples have been characterized morphologically by scanning electron microscopy (SEM) and a structurally by Raman spectroscopy. These analyses show that, when the temperature of substrate increases, the CNT average diameter and the density distribution decrease, and the CNTs are less defective. However there is a temperature limit (725 °C) for CNT growth. We have grown CNTs onto Si3N4/Si substrates with Pt electrodes, in order to realize the gas sensing devices. The CNTs grown at 725 °C, exhibit a fast response and a high sensitivity to NO2 gas.
Inorganic Phosphor Materials for Solid State White Light Generation
Authors: Dutta Dimple P. , Tyagi A.K.
Published: September 2009

Solid-state lighting (SSL) is emerging as a highly competent field and a possible alternative to existing lighting technologies. Development of a suitable phosphor is an important aspect of SSL. The aim of this review is to summarize status of Inorganic Phosphors towards SSL applications. Various examples have been taken from oxide, fluoride, nitride, sulfide and phosphate based host lattices. The important concepts like CIE coordinates and Color Correlated Temperature (CCT) will also be discussed. The sections encompasses of red, blue and green light emitting phosphors. The white light emitting phosphors will also be discussed in details.
Dielectric and Conductivity Studies of Sr[(Mg0.32Co0.02) Nb0.66]O3 Thin Film
Authors: Mehta P.K. , Bishnoi Bhagwati , Kumar Ravi , Choudhary R.J. , Phase D.M.
Published: September 2009

Study of Sr[(Mg0.32Co0.02) Nb0.66]O3 [SMCN] thin films prepared by Pulsed Laser Deposition Technique (PLD) were carried out in the temperature range of 150 to 450K and frequency range of 100KHz to 1.1MHz. X-ray diffraction of the thin film shows single phase formation with monoclinic symmetry. The dielectric properties show enhanced ε' values compared to bulk suggesting promising applications in alternative technologies. Due to simultaneous increase in dissipation factor with temperature the net ac conductivity is found to be decreasing. Technologically important two step activation energy is observed in the film. This property can be used in switching devices. In low temperature region the activation energy corresponds to shallow traps while the migration of oxygen vacancies contributes in high temperature region.
An Electronic Structure Study of Mn Doped ZnO Diluted Magnetic Semiconductor Using X-Ray Absorption and Photoemission Techniques
Authors: Singhal R.K. , Dhawan M.S. , Gaur S.K. , Saitovitch Elisa
Published: September 2009

ZnO semiconductor doped with a few per cent of some transition metal ions can exhibit above room temperature ferromagnetism, transforming it into a very promising candidate for future spin-electronic applications. In the present article we have compared the electronic structure of two polycrystalline ZnMnO pellets doped with diluted Mn concentration (2% and 4%), carefully characterized by SQUID and XRD, including Rietveld refinement. The characterization measurements established that the samples have the ZnO lattice with ZnS type Wurtzite hexagonal symmetry and no detectable impurities. The samples exhibit distinctly different magnetic properties. The 2% sample displayed a clear FM ordering at 300 K while the 4% sample did not show any ordering down to 5K. The electronic structure of these two samples has been investigated using Mn L23 x-ray absorption spectroscopy, Zn 2p and 3p, Mn 3p and O 1s x-ray photoemission spectroscopy. Our aim was to find out how the changes in the electronic structure can correlate to the observed magnetic properties in such diluted magnetic semiconductor materials. The results show that most of the Mn ions of the ferromagnetic sample are in the divalent state. For the higher Mn percent nonmagnetic sample, a larger contribution of higher oxidation Mn states are dominant and the oxygen content also increases. The two factors can be correlated to the suppressed ferromagnetism, though it is hard to pinpoint that which of these two weighs more in the suppression mechanism.
Strategies for Overcoming Site and Recruitment Challenges in Research Studies Based in Intensive Care Units
Authors: Chlan Linda , Guttormson Jill , Tracy Mary Fran , Bremer Karin Lindstrom
Published: September 2009

Although enrolling a sufficient number of participants is a challenge for any multisite clinical trial, recruiting patients who are critically ill and receiving mechanical ventilatory support presents additional challenges because of the severity of the patients’ illness and the impediments to their communication. Recruitment challenges related to the research sites, nursing staff, and research participants faced in the first 2 years of a 4-year multisite clinical trial of a patient-directed music intervention for managing anxiety in the intensive care unit were determined. Strategies to overcome these challenges, and thereby increase enrollment, were devised. Individual strategies, such as timing of screening on a unit, were tailored to each participating site to enhance recruitment for this trial. Other strategies, such as obtaining a waiver for a participant’s signature, were instituted across all participating sites. Through implementation of these various strategies, the mean monthly enrollment of participants increased by 50%. Investigators are advised to plan well in advance of starting recruitment for a clinical trial based in an intensive care unit, anticipate peaks and valleys in recruitment, and be proactive in addressing issues creatively as the issues arise.
Surrogate Consent for Genomics Research in Intensive Care
Authors: Shelton Ann K. , Fish Anne F. , Cobb J. Perren , Bachman Jean A. , Jenkins Ruth L. , Battistich Victor , Freeman Bradley D.
Published: September 2009

Surrogate decision makers may be poorly prepared to give informed consent for genomics research for their loved ones in intensive care. A review of the challenges and strategies associated with obtaining surrogates’ consent for genomics research in intensive care patients revealed that few well-controlled studies have been done on this topic. Yet, a major theme in the literature is the role of health care professionals in guiding surrogates through the informed consent process rather than simply witnessing a signature. Informed consent requires explicit strategies to approach potential surrogates effectively, educate them, and ensure that informed consent has been attained.
The Results of a New Distal Protection Method in Intervention for Chronic Total Occlusion of the Superficial Femoral Artery
Authors: Kobayashi Tomoko , Funatsu Atsushi , Ejima Emiko , Muranishi Hiromi , Utsunomiya Makoto , Shibata Kensaku , Mizobuchi Masahiro , Enjoji Yoshihisa , Nakamura Shigeru
Published: September 2009

Aims. To determine the efficacy of a new distal protection method in SFA CTO interventions.Methods and Results. From June 2003 to February 2009, ninety-two consecutive, chronic total occlusions of superficial femoral arteries were treated with catheter-based intervention using a bidirectional approach. Nine of these cases were managed with our original, distal protection method, based on symptoms, angiographic images, wire resistance, and intravascular ultrasound images. The average age was 73 years; eight patients were male. The mean occlusion length was 17.1 cm. A distal protection balloon was inserted from the retrograde sheath in the popliteal artery and placed distal to the occluded lesion after successful wire crossing. Lesion dilatation with a balloon was performed antegradely and debris was removed by 6Fr. guiding catheter. Debris was retrieved from all lesions, consisting mainly of thrombus. Where we decided not to use the distal protection method, there was no distal thromboembolism.Conclusion. In SFA-CTO intervention, the risk of distal embolization is 10%, which can be anticipated and eliminated by the distal protection method.
Molecular Microbial Analysis ofLactobacillusStrains Isolated from the Gut of Calves for Potential Probiotic Use
Authors: Soto Lorena P. , Frizzo Laureano S. , Bertozzi Ezequiel , Avataneo Elizabeth , Sequeira Gabriel J. , Rosmini Marcelo R.
Published: September 2009

The intestinal microbiota has an influence on the growth and health status of the hosts. This is of particular interest in animals reared using intensive farming practices. Hence, it is necessary to know more about complexity of the beneficial intestinal microbiota. The use of molecular methods has revolutionized microbial identification by improving its quality and effectiveness. The specific aim of the study was to analyze predominant species ofLactobacillusin intestinal microbial ecosystem of young calves. Forty-two lactic acid bacteria (LAB) isolated from intestinal tract of young calves were characterized by: Amplified Ribosomal DNA Restriction Analysis (ARDRA), by usingHaeIII,MspI, andHinfI restriction enzymes, and 16S rDNA gene sequencing. ARDRA screening revealed nine unique patterns among 42 isolates, with the same pattern for 29 of the isolates. Gene fragments of 16S rDNA of 19 strains representing different patterns were sequenced to confirm the identification of these species. These results confirmed that ARDRA is a good tool for identification and discrimination of bacterial species isolated from complex ecosystem and between closely related groups. This paper provides information about the LAB species predominant in intestinal tract of young calves that could provide beneficial effects when administered as probiotic.
Intracranial Vertebrobasilar Artery Dissection Associated with Postpartum Angiopathy
Authors: McKinney James S. , Messé Steven R. , Pukenas Bryan A. , Satti Sudhakar R. , Weigele John B. , Hurst Robert W. , Levine Joshua M. , Kasner Scott E. , Sansing Lauren H.
Published: September 2009

Background. Cervicocephalic arterial dissection (CCAD) is rare in the postpartum period. To our knowledge this is the first reported case of postpartum angiopathy (PPA) presenting with ischemic stroke due to intracranial arterial dissection.Case. A 41-year-old woman presented with blurred vision, headache, and generalized seizures 5 days after delivering twins. She was treated with magnesium for eclampsia. MRI identified multiple posterior circulation infarcts. Angiography identified a complex dissection extending from both intradural vertebral arteries, through the basilar artery, and into both posterior cerebral arteries. Multiple segments of arterial dilatation and narrowing consistent with PPA were present. Xenon enhanced CT (Xe-CT) showed reduced regional cerebral blood flow that is improved with elevation in blood pressure.Conclusion. Intracranial vertebrobasilar dissection causing stroke is a rare complication of pregnancy. Eclampsia and PPA may play a role in its pathogenesis. Blood pressure management may be tailored using quantitative blood flow studies, such as Xe-CT.
Late Onset Postpartum Eclampsia: It is Really Never Too Late—A Case of Eclampsia 8 Weeks after Delivery
Authors: Minnerup Jens , Kleffner Ilka , Wersching Heike , Zimmermann Julian , Schäbitz Wolf-Rüdiger , Niederstadt Thomas , Dziewas Rainer
Published: September 2009

Introduction. Eclampsia is the combination of preeclampsia and seizures. Approximately one-half of all cases of eclampsia occur postpartum. Thereby late onset postpartum eclampsia is defined by its onset more than 48 hours after delivery.Summary of Case. We report a postpartum eclampsia occurring 8 weeks after delivery, which is the latest onset ever described. The course was complicated by an intracerebral hemorrhage (ICH).Conclusion. A late onset postpartum eclampsia even several weeks after delivery should be considered as possible diagnosis, since early treatment initiation with magnesium sulphate and antihypertensive medication prevents severe complications and reduces mortality.
Necrotizing Infiltrative Lipomatosis in a Miniature Zebu Bull (Bos primigenius indicus)
Authors: Reed Scott D. , Evans Dawn E.
Published: September 2009

Lipomatosis is described in a miniature Zebu,Bos primigenius indicus, bull that died of perianesthetic complications. This is the first pathologic description of lipomatosis that we are aware of in this species and breed of cattle. Infiltration of multiple visceral organs is described and depicted along with comparison to previously published cases of lipomatosis in other breeds of cattle.
Analyzing Gene Expression Data from Microarray and Next‐Generation DNA Sequencing Transcriptome Profiling Assays Using GeneSifter Analysis Edition
Authors: Porter Sandra , Olson N. Eric , Smith Todd
Published: September 2009

Transcription profiling with microarrays has become a standard procedure for comparing the levels of gene expression between pairs of samples, or multiple samples following different experimental treatments. New technologies, collectively known as next‐generation DNA sequencing methods, are also starting to be used for transcriptome analysis. These technologies, with their low background, large capacity for data collection, and dynamic range, provide a powerful and complementary tool to the assays that formerly relied on microarrays. In this chapter, we describe two protocols for working with microarray data from pairs of samples and samples treated with multiple conditions, and discuss alternative protocols for carrying out similar analyses with next‐generation DNA sequencing data from two different instrument platforms (Illumina GA and Applied Biosystems SOLiD). Curr. Protoc. Bioinform. 27:7.14.1‐7.14.35. © 2009 by John Wiley & Sons, Inc.
Strategies in visuospatial working memory for learning virtual shapes
Authors: Smith Glenn Gordon , Ritzhaupt Albert Dieter , Tjoe Edwin
Published: September 2009

This study investigated visuospatial working memory (WM) strategies people use to remember unfamiliar randomly generated shapes in the context of an interactive computer‐based visuospatial WM task. In a three‐phase experiment with random shapes, participants (n = 94) first interactively determined if two equivalent shapes were rotated or reflected; second, memorized the shape; and third, determined if an imprint in a profile view of the ground was a rotated, reflected imprint of the shape, or an imprint not matching the original shape. Participants self‐reported these strategies: Key feature, shape interaction, association/elaboration, holistic/perspective, divide and conquer, mental rotation/reflection and others. Participants reporting key features strategy were significantly more accurate on the computer‐based visuospatial WM task. These results highlight the importance of strategy in visuospatial WM. Copyright © 2009 John Wiley & Sons, Ltd.
Identical cryptic partial monosomy 20pter and trisomy 20qter in three adult siblings due to a large maternal pericentric inversion: Detection by MLPA and breakpoint mapping by SNP array analysis
Authors: Stevens Servi J.C. , Smeets Eric E.J.G.L. , Blom Eveline , van Uum Chris M.J. , Albrechts Jozefa C.M. , Herbergs Jos , Janssen Jannie W.M. , Engelen John J.M.
Published: September 2009

Genotypic and phenotypic data are presented on three adult siblings with mild to moderate mental retardation and mild dysmorphic features. All three siblings showed a chromosome 20 gain at the q‐telomere and loss at the p‐telomere in routine subtelomeric MLPA screening. Analysis of GTG‐banded chromosomes did not detect any abnormalities, but subtelomeric fluorescent in situ hybridization (FISH) confirmed cryptic partial monosomy of chromosome region 20p13 → 20pter and cryptic partial trisomy of chromosome region 20q13.33 → 20qter. Furthermore, FISH analysis in the mother showed a cryptic inv(20)(p13q13.33). This explained the cytogenetic mechanism underlying the chromosomal imbalance in the three children, that is, the meiotic formation of a recombinant chromosome 20 due to crossing‐over in the inverted segment. All three children thus carried a rec(20)dup(20q)inv(20)(p13q13.33)mat chromosome. SNP array analysis enabled rapid and detailed imbalance sizing and showed a 1.06 Mb loss in 20p13 and a 2.51 Mb gain in 20q13.33, comprising 21 and 78 genes, respectively. The maternal inversion is the largest described thus far for chromosome 20, comprising 94.4% of its length. Such large inversions result in a particularly high risk for live‐born unbalanced offspring because the partial monosomy and trisomy segments are small. Moreover, the inversion size is directly related to the percentage of unbalanced gametes due to high crossing‐over change within the inverted segment. The fact that all three children carry an identical chromosomal rearrangement has consequences for genetic counseling for carriers of large pericentric inversions, as the recurrence risk is very high. © 2009 Wiley‐Liss, Inc.
Multiple genomic aberrations in a patient with mental retardation and hypogonadism: 45,X/46,X,psu dic(Y) karyotype, thyroid hormone receptor beta (THRB) mutation and heterozygosity for Wilson disease
Authors: Hes Frederik J. , Madan Kamlesh , Rombout‐Liem I. Shan , Szuhai Karoly , Sørensen Helena , van Amstel Hans Kristian Ploos , Bakker Egbert , Visser Theo J. , Smit Johannes W. , Hansson Kerstin
Published: September 2009

We report on multiple genomic aberrations in a patient with mental retardation. In addition, he had hypogonadism, elevated thyroid hormone levels, hearing loss, delayed speech development and mild dysmorphic features. First, we identified a mosaic karyotype, 45,X/46,X,psu dic(Y). The pseudo‐dicentric Y chromosome has three short arm segments. Second, we found a germline mutation (Pro453Thr) of the thyroid hormone receptor beta (THRB) which is associated with resistance to thyroid hormone. Third, he was found to be a carrier of a heterozygous ATP7B mutation (c.2575 + 5G > C), the Wilson disease gene. Even though an array‐CGH (with a density of ∼1 Mb) did not reveal any further genomic gains or losses, we cannot exclude that all contributing factors have been identified. However, this case report shows that with increasing technological possibilities we can find more than one cause for developmental problems in a single patient. The identification of multiple causes in a single patient may complicate explaining the disorder and genetic counseling. © 2009 Wiley‐Liss, Inc.
Physicochemical and electrochemical characterizations of organic montmorillonite (OMMT)/sulfonated poly(ether ether ketone) (SPEEK) composite membranes
Authors: Gosalawit R. , Figoli A. , Chirachanchai S.
Published: September 2009

Physicochemical and electrochemical properties of the organic montmorillonite (OMMT)/sulfonated poly(ether ether ketone) (SPEEK) composite membranes are considered for their use as proton conducting membranes. The paper presents the preparation and characterization of SPEEK and its composite membranes with OMMT as well as their comparison to the reference Nafion® 117 membrane. Water uptake and thermal property (Td1) are improved when the OMMT loading content increases. Methanol permeability decreases as OMMT loading content increases up to as high as 53% (5 wt% OMMT/SPEEK composite membrane). For proton conductivity, all membranes show improvement when the operating temperature increases from 25 to 90 °C. The proton conductivity at 100 °C of 3 wt% OMMT/SPEEK composite membrane (5.6 × 10−2 S/cm) is one order of magnitude higher than that of Nafion® 117 (2 × 10−3 S/cm). Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Innovative membrane based process for the selective oxidation of light alkanes assisted by the Fenton system
Authors: Espro C. , Mendolia F. , Marini S. , Frusteri F. , Parmaliana A.
Published: September 2009

Selective oxidation of light alkanes under mild conditions (temp, 80–120 °C; pressure, 140 kPa) mediated by Fe2+/H2O2 Fenton system on Nafion based composite membranes is studied in a multifunctional three phase catalytic membrane reactor (3PCMR). The role of textural properties and acid functionality on the catalytic performance of the Nafion composite membranes is outlined. The features of the multifunctional 3PCMR, enabling reaction along with product separation and recovery, are discussed. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
New poly ether ether ketones containing phosphorus for membrane preparation
Authors: Trotta Francesco , Mio Simona Ceresa , Martina Katia , Drioli Enrico , Finocchiaro Paolo
Published: September 2009

In this study is reported the synthetic procedure and the characterisation of novel phosphorus containing polyether ether ketone (PEEK‐P). The new polymer was synthesized via direct polycondensation of 2,2‐bis(3‐diethylphosphono‐4‐hydroxyphenyl)‐propane and 4,4′‐difluorobenzophenone according to well known general procedure and was extensively characterized by using infrared spectroscopy (FT‐IR), thermogravimetric analyses (TGA), viscosity measurements and †H‐NMR analysis. The obtained polymer is soluble in some organic solvents and the solution of phosphonated polymer could be used to obtain membranes by using the phase inversion technique. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Sentiment analysis of Chinese documents: From sentence to document level
Authors: Zhang Changli , Zeng Daniel , Li Jiexun , Wang Fei‐Yue , Zuo Wanli
Published: September 2009

User‐generated content on the Web has become an extremely valuable source for mining and analyzing user opinions on any topic. Recent years have seen an increasing body of work investigating methods to recognize favorable and unfavorable sentiments toward specific subjects from online text. However, most of these efforts focus on English and there have been very few studies on sentiment analysis of Chinese content. This paper aims to address the unique challenges posed by Chinese sentiment analysis. We propose a rule‐based approach including two phases: (1) determining each sentence's sentiment based on word dependency, and (2) aggregating sentences to predict the document sentiment. We report the results of an experimental study comparing our approach with three machine learning‐based approaches using two sets of Chinese articles. These results illustrate the effectiveness of our proposed method and its advantages against learning‐based approaches.
Parent‐selected interventions for infants at‐risk for autism spectrum disorders and their affected siblings
Authors: Regehr Kaleigh , Feldman Maurice
Published: September 2009

Infants with older siblings having Autism Spectrum Disorders (ASD) are at genetically increased risk for showing characteristics of ASD in the first 2 years of life. Parents, who already have at least one child with ASD, may closely monitor their later born children and implement interventions as soon as the children begin to show what the parents believe is aberrant behavior or development that may be early stages of ASD. To date, no study has examined the number and types of services and interventions these parents access for their at‐risk infants. Using a Service and Intervention Questionnaire developed for this study, we interviewed 23 parents involved in a larger prospective study of genetically at‐risk infants who reported developmental and/or behavior problems in their at‐risk infants. Parents reported utilizing a mean of 1.83 and 7.26 services and/or interventions for their at‐risk infants and older children with ASD, respectively. Two‐thirds of the interventions received by the infants were also given to their older affected siblings. The interventions included empirically validated approaches (e.g., early intensive behavioral intervention), professional services (speech–language therapy, occupational therapy), and non‐validated treatments (e.g., diet and vitamin therapies). Overall, 81 non‐validated and 18 validated interventions were used. On a Likert‐type rating scale, parents reported being involved and satisfied with what they generally thought were effective services. They felt more involved and satisfied with ABA, and felt it was more effective than non‐validated interventions. The findings suggest that parents with infants at‐risk for ASD and an older affected child will access a variety of autism services for both children, but the parents will implement primarily non‐validated interventions. Parent education is recommended to help parents make informed treatment decisions for their children. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling the influence of cyclodextrins on oral absorption of low solubility drugs: II. Experimental validation
Authors: Gamsiz Ece Dilber , Miller Lee , Thombre Avinash G. , Ahmed Imran , Carrier Rebecca Lyn
Published: September 2009

A model was developed for predicting the influence of cyclodextrins (CDs) delivered as a physical mixture with drug on oral absorption. CDs are cyclic oligosaccharides which form inclusion complexes with many drugs and are often used as solubilizing agents. The purpose of this work is to compare the simulation predictions with in vitro as well as in vivo experimental results to test the model's ability to capture the influence of CD on key processes in the gastrointestinal (GI) tract environment. Dissolution and absorption kinetics of low solubility drugs (Naproxen and Nifedipine) were tested in the presence and absence of CD in a simulated gastrointestinal environment. Model predictions were also compared with in vivo experimental results (Glibenclamide and Carbamazepine) from the literature to demonstrate the model's ability to predict oral bioavailability. Comparisons of simulation and experimental results indicate that a model incorporating the influence of CD (delivered as a physical mixture) on dissolution kinetics and binding of neutral drug can predict trends in the influence of CD on bioavailability. Overall, a minimal effect of CD dosed as a physical mixture was observed and predicted. Modeling may aid in enabling rational design of CD containing formulations. Biotechnol. Bioeng. 2010; 105: 421–430. © 2009 Wiley Periodicals, Inc.