bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Heat-Treatment on the Phases of Ni-Mn-Ga Magnetic Shape Memory Alloys
Authors: Ari-Gur Pnina , Kimmel Giora , Richardson James W. , Huq Ashfia , Sharma Kapil
Published: September 2009

The Heusler alloys Ni50Mn25+xGa25-x display magnetic shape memory effect (MSM) with very fast and large reversible strain under magnetic fields. This large strain and the speed of reaction make MSM alloys attractive as smart materials. Our crystallographic investigation of these alloys, focused on non-stoichiometric composition with excess of manganese. Using neutron diffraction, we revealed the necessary processing parameters to achieve and preserve the homogeneous metastable one-phase martensitic structure that is needed for an MSM effect at room temperature.
Second Harmonic Generation in Core (Shell) γ-Fe2O3 (Au) Nanoparticles
Authors: Kolmychek I.A. , Murzina T.V. , Fourier S. , Wouters J. , Valev V.K. , Verbiest T. , Aktsipetrov O.A.
Published: September 2009

The films containing core (shell) γ-Fe2O3 (Au) nanoparticles that possess the plasmon resonance at the wavelength 550 nm are prepared. The second harmonic generation in these structures is shown to be diffuse and depolarized, that is typical for the hyper-Rayleigh scattering.. The studies of the magnetization-induced second harmonic generation shows that the ratio of the magnetic to nonmagnetic components of the hyperpolarizability of a single nanoparticle, γM/γ0 ~ 0.4 in the field of about 3 kOe.
Magnetic Force Microscopic Study on Domain-Wall Molecules in NiFe Nano Rings
Authors: Sasage Kohei , Okamoto Naoya , Tsujikawa Hana , Yamaoka Takehiro , Saitoh Eiji
Published: September 2009

A pair of magnetic domain walls (DWs) in ferromagnetic NiFe rings has been investigated in terms of the magnetic force microscopy (MFM). When the distance between the rings d is greater than a threshold value dth, MFM signals indicate that a DW in the ring is dragged due to a stray magnetic field from an MFM probe tip. When d < dth, this drag signals disappears; DWs are bound to each other by the DW-DW interaction. This transition can be argued in terms of the competition between the DW-DW magnetostatic interaction and the DW-drag potential. From the d-dependent MFM data, the DW-drag potential was estimated.
X-Ray Diagnostics of Magnetic Semiconductor Quantum Well Structures
Authors: Likhachev I.A. , Pashaev E.M. , Chuev M. A. , Subbotin I.A. , Kvardkov V.V. , Aronzon B.A. , Rylkov V.V. , Golovanov A.Ye. , Pankov M.A.
Published: September 2009

In the present contribution the results of the high-resolution X-ray diffraction and X-ray glancing-incidence mirror reflection studies of structural characteristics of the quantum-well GaAs/Ga1-xInxAs/GaAs diluted magnetic semiconductors (DMSC) are presented. The influence of the real structure of the samples on their electro-physical properties is discussed.
Features of the Post-Deformation Hardening of Fe-Cr-Co Hard Magnetic Alloys with W and Ga Additives
Authors: Belozerov E.V. , Shchegoleva N.N. , Ivanova G.V. , Mushnikov N.V.
Published: September 2009

The structure, mechanical and magnetic properties have been studied for Fe-Cr-Co-based hard magnetic alloys with W and Ga additives, subjected by the quenching and post-deformation hardening. The alloys combine the properties of the hard magnetic material with outstanding mechanical strength and plasticity. Using X-ray and electron microscopy analysis, the reasons and conditions of formation of these properties have been determined.
High Field Magnetoresistance Behavior in PrB6 and NdB6
Authors: Anisimov M.A. , Glushkov V.V. , Demishev S.V. , Samarin N.A. , Shitsevalova N.Y. , Sluchanko N.E.
Published: September 2009

The comprehensive study of low temperature magnetoresistance (MR) has been carried out on high quality PrB6 and NdB6 single crystals at temperatures 2–20K and in magnetic fields up to 8T. The negative MR (Δρ/ρ<0) was found in the paramagnetic state at T>TN for both compounds. The analysis of the experimental data allows us to establish three contributions to MR. In addition to the main Brillouin type negative component –Δρ/ρ~Mloc2~H2 which may be interpreted in terms of Yosida theory [Phys. Rev. 107 (1957) 396] both the linear and nonlinear magnetic contributions were also deduced. According to detailed analysis in the framework of spin–polaron approach proposed by A.V. Bogach et al. [Physica B 378–380 (1957) 769] the last component should be ascribed to the ferromagnetic (FM) nanodomains embedded in the metallic RB6 matrix. The estimation of local magnetic susceptibility χloc=(–1/H•(d(Δρ/ρ)/dH))1/2 is deduced directly from the quadratic part of negative MR and reveals Curie–Weiss type behaviour in paramagnetic (PM) phase with paramagnetic Curie temperatures Θp~– 22K and –31K for PrB6 and NdB6 correspondingly. The results of undertaken analysis allow to conclude in favour of the concurrence between AF and FM iteractions as the main reason of incommensurate (IC) magnetic structure formation in RB6.
Investigation of Magnetic and Thermal Properties of Model Fe/V Superlattices
Authors: Khizriev Kamal Sh. , Murtazaev Akai K. , Uzdin Valery M.
Published: September 2009

A model for iron/vanadium superlattices was proposed to study the phase transition in multilayers. The temperature dependence of magnetization, susceptibility, and specific heat were obtained. Two specific heat peaks are revealed at small ratios of interlayer and intralayer exchange.
Conditions for the Spin-Spiral State in Itinerant Magnets
Authors: Timirgazin M.A. , Arzhnikov Anatoly K.
Published: September 2009

The spin-spiral (SS) type of magnetization is studied with the Hubbard model. Consideration of noncollinearity of the magnetic moments results in a phase diagram which consists of regions of the SS and paramagnetic states depending on the number of electrons nel and the parameter U/t (U is the Hubbard repulsion, and t is an overlap integral). A possibility of stabilization of the SS state with three nonzero components of magnetic moment is considered.
Investigation of the 3D ANNNI Model by Monte Carlo Methods
Authors: Murtazaev Akai K. , Ibaev J.G. , Abuev Ya.K.
Published: September 2009

The results for 3D anisotropic Ising model with competing interactions (ANNNI) investigated by the Monte Carlo methods are presented. The temperature dependence of thermal parameters is calculated. The character of all possible phase transitions in the model is analyzed.
Temperature Hysteresis in the Dynamic Spin-Fluctuation Theory for Strong Ferromagnets
Authors: Reser B.I. , Grebennikov Vladimir I. , Melnikov N.B.
Published: September 2009

Temperature dependence of magnetic characteristics of Fe and Fe-Ni invar is considered in the dynamic nonlocal approximation of the spin-fluctuation theory. Numerical calculations show that the magnetic characteristics can have a discontinuous jump at high temperatures, well below the Curie temperature. Using methods of the catastrophe theory, we investigate the effect of small changes in the initial data on the results of the calculation. It is demonstrated that the discontinuous jump can only be smoothed but cannot be eliminated entirely without a significant change in the system of equations of the spin-fluctuation theory. Possible variants of such changes are discussed.
Charge and Spin Pairing Instabilities in Hubbard Nanoclusters
Authors: Kocharian A.N. , Fernando G.W. , Palandage K. , Davenport J.W.
Published: September 2009

Electron coherent and incoherent pairings and other types of correlations are studied exactly for the ensemble of small clusters with different geometries under variation of interaction strength, electron doping and temperature. Charge and spin collective excitations yield intriguing insights into level crossing degeneracies, phase separation and condensation. Criteria for spin-charge separation and recombination driven by interaction strength and temperature are found. Phase diagrams resemble a number of inhomogeneous, nanoscale phases and pseudogap regions seen recently in high TC cuprates, manganites, multiferroics and CMR nanomaterials.
Magnetic and Structural Phase Transitions in Monochalcogenides of Uranium
Authors: Kassan-Ogly Felix A. , Filippov B.N.
Published: September 2009

The theory of simultaneous magnetic and structural first-order transitions in crystals with strong cubic magnetic anisotropy is developed on the basis of a combination of the magnetic modified 8-state Potts model [1] and theoretical models of structural phase transitions in cubic crystals [2]. The magnetic heat capacity and specific volume, as well as the temperature dependence of the rhombohedron angle, are calculated in a wide temperature range. The calculation of the temperature evolution of high-temperature diffuse magnetic neutron scattering was performed. It was demonstrated that upon passing the Curie point the spectra characteristic of the diffuse scattering are transformed to the magnetic Bragg peaks.
Giant Magnitostriction of Diluted Nickel Ferrite NiGa0.8Al0.8Fe0.4O4 with Frustrated Magnetic Structure
Authors: Antoshina L.G. , Korshak A.B.
Published: September 2009

The investigation of magnetic properties of diluted ferrite NiGa0.8Al0.8Fe0.4O4 is carried out. Anomalous behaviour of spontaneous magnetization σs(T), coercive force Hc(T) and volume magnetostriction ω(T) is revealed for the sample with frustrated magnetic structure. It is found that volume magnetostriction ω reaches very large (that is to say “giant”) values (ω ~ 5•10–4) (for T = 84 K). It is revealed that the derivative dω/dH is equal ≈ 43 • 10–9 Oe–1 (for T = 84 K). The assumption is made that the size of clusters is about 3 nm in the spin glass phase (for Tt < T < TC).
Rapid Prototyping Methodologies for Ceramic Micro Components
Authors: Chalker P.R. , Berggreen K.M. , Clare A.T. , Singh J. , Sutcliffe C.J.
Published: September 2009

This paper investigates the rapid prototyping of components from ceramics. Selective laser sintering of barium titanate powder has been investigated as a potential route to manufacturing freeform electro-ceramic based components. Raman spectroscopy has been used to investigate the effect of laser power and oxygen partial pressure on the phase and composition of the sintered material. It is shown that the sintering laser power strongly influences the composition. As the laser power is increased during sintering, the Eg mode of anatase becomes evident at 640 cm-1. When the oxygen partial pressure in the sintering atmosphere is reduced from 19% to 0.2% the whole depth of the powder bed sampled by Raman spectroscopy resembles bulk anatase.
Experimental Validation of Numerical Methods of MRE Simulations
Authors: Szymczyk Wiesław , Boczkowska Anna , Niezgoda Tadeusz , Zubko Konrad
Published: September 2009

This paper deals with the development of magnetoactive elastomers (MREs) based on the carbonyl iron particles-filled polyurethane resin. Their stiffness can be changed easily by magnetic field. Such a property can be useful in construction of active vibration damping structural elements.
For the needs of numerical modelling methods validation the elementary case of the two magnetic particles was investigated experimentally.
Special “macro samples” were prepared with pairs of ferromagnetic particles of spherical shape of diameter of 12.7 mm. They provided easy observations and measurements. The gap distance between particles was established on the level of ¼ of the diameter.
After application of the magnetic field particles started to attract each other like magnetic dipoles.
The mutual displacement of the dipoles was recorded in function of the magnetic field intensity, which was varied in the range100÷300 [mT].
The deformation field was also obtained from the digital image processing (DIC).
Then the experiment was simulated numerically with the use of the 3D FEM models. The dipoles were loaded by forces which were increased gradually until displacements reached values that were measured experimentally. Calculations were performed on the MSC Patran-MARC platform. The Neo-Hookean material model was used to describe properties of the resin matrix. Magneto-mechanical coupling was taken into consideration with the use of an iterative method.
The results of calculations were compared with the experimental results. The validation of the base modelling concept was successfully completed.
Magnetic Field Analysis for Magnetron Sputtering Apparatus for Accurate Composition Control
Authors: Sakurai Yutaka , Nakajima Ryo , Nakamura Hiroko
Published: September 2009

Authors use magnetron sputtering technique for controlling the film composition by modifying the magnetic field with an external solenoid in addition to the magnetic field with a permanent magnet on back of composite target. It is necessary to understand the contribution of the solenoid quantitatively for the effective application of this technique. The magnetic field changes by the solenoid current on the target were calculated by the finite element method (FEM), and compared with the film composition. As the solenoid current increases, magnetic tunnel region on the target (correspond with the well sputtered region by the confined plasma) moves to the centre of the target. The behaviour corresponds with the actually formed film composition. The calculated results also give an information to design the composite target and the correction value for using the already eroded target.
Smart Technologies for Adaptive Impact Absorption
Authors: Holnicki-Szulc Jan , Graczykowski C. , Mikułowski G. , Mróz A. , Pawłowski P.
Published: September 2009

The article presents a review of recent research carried out in the Department of Intelligent Technologies of Institute of Fundamental Technological Research, dedicated to application of systems for adaptive impact absorption to adaptive aircraft landing gears, novel concept of protective MFM structures, flow-control based airbags, maritime applications of inflatable structures, and development of adaptive wind turbine blade – hub connections.
Measurements of Strain in Ceramic Components Using Magnetostrictive Delay Line
Authors: Szewczyk Roman , Salach Jacek , Bieńkowski Adam , Kostecki Marek , Olszyna Andrzej Roman , Kolano-Burian Aleksandra
Published: September 2009

Paper presents a novel application of magnetostrictive delay lines, which give a possibility of real time monitoring of strain in ceramic components. Magnetostrictive delay line was based on highly magnetostrictive Fe-Si-B amorphous alloy ribbon, mounted outside of ceramic component, what is a new solution for increasing sensor’s sensitivity. Developed specially for this sensor, hybrid digital-analog signal processing unit covers the sample-and-hold integrated circuit. The achived sensitivity and repeatability of the sensor confirms, that such solution is suitable for ceramic machine tool monitoring.
A Simulation Study of Magnetostrictive Material Terfenol-D in Automotive CNG Fuel Injection Actuation
Authors: Chowdhury H.A. , Mazlan Saiful Amri , Olabi Abdul Ghani
Published: September 2009

Magnetostriction is the deformation that spontaneously occurs in ferromagnetic materials when an external magnetic field is applied. In applications broadly defined for actuation, magnetostrictive material Terfenol-D (Tb0.3Dy0.7Fe1.9) possesses intrinsic rapid response times while providing small and accurate displacements and high-energy efficiency. These are some of the essential parameters required for fast control of fuel injector valves for decreased engine emissions and lower fuel consumption compared with the traditional solenoid fuel injection system. A prototype CNG fuel injector assembly was designed which included magnetostrictive material Terfenol-D as the actuator material. A 2D cross-sectional geometry of the injector assembly, which incorporated both linear and non-linear magnetic properties of the corresponding materials, was modeled in ANSYS for 2D axisymmetric magnetic simulation. Subsequently, a 3D replica of the CNG flow conduit was modeled in GAMBIT with the resultant injector lift. The meshed conduit was then simulated in FLUENT using the 3D time independent segregated solver with the Standard k  , the Realizable k   and RSM turbulence models to predict the mass flow rate of CNG to be injected. Eventually, the simulated flow rate was verified against mathematically derived static flow rate required for a standard automotive fuel injector considering standard horsepower, BSFC and injector duty cycle.
Structure and Shape Memory Effect in Annealed Ni-Ti-Co Strip Produced by Twin Roll Casting Technique
Authors: Goryczka Tomasz
Published: September 2009

The ternary Ni47Ti50Co3 alloy was produced using twin rolls casting technique. The strip was annealed at 3000C, 4000C or 5000C for 1 hour. Annealing was carried out in real condition without protection atmosphere. The strips revealed a multi-stage martensitic transformation. However, the origin of this multi-stage transformation is different in the as-cast strip when compare to the thermally treated samples. Thermal treatment increases amount of preferentially oriented grains and in consequence higher degree of the shape recovery can be obtained.
Suppressed Field Emission Screening Effect and Electric Field Simulation of Carbon Nanotube-Based Triode Field Emitters
Authors: Koohsorkhi Javad , Davoudzadeh Nima , Mohajerzadeh Shamsoddin , Asl Soleimani Ebrahin , Ghafouri Fard Hasan
Published: September 2009

In this paper the electric field simulation of carbon nanotubes triode field emission devices is investigated. The geometry of CNTs and their arrangement on the substrate affect the screening effect and filed enhancement factor (β). In an array of nanotubes, for a distance smaller than the CNT length the screening effect is observed. The emission current density is related to the gate aperture and CNT shape. In a triode structure the screening effect occurs in the intertube distances about half of the CNT’s length due to the presence of the gate plate. Furthermore, the presence of the metal-oxide gate has a favorable effect to minimize the screening effect and allows one to increase the density of CNT’s in each array spot and to increase the cluster array density on the substrate, hence to increase the density of emission current and emitter sites where a high current density is required.
Formation of Metal Silicide Nanodots on Ultrathin SiO2 for Floating Gate Application
Authors: Miyazaki Seiichi , Ikeda Mitsuhisa , Makihara Katsunori , Shimanoe K. , Matsumoto R.
Published: September 2009

We demonstrated a new fabrication method of Pt- and Ni-silicide nanodots with an areal density of the order of ~1011 cm-2 on SiO2 through the process steps of ultrathin metal film deposition on pre-grown Si-QDs and subsequent remote H2 plasma treatments at room temperature. Verification of electrical separation among silicide nanodots was made by measuring surface potential changes due to electron injection and extraction using an AFM/Kelvin probe technique. Photoemission measurements confirm a deeper potential well of silicide nanodots than Si-QDs and a resultant superior charge retention was also verified by surface potential measurements after charging to and discharging. Also, the advantage in many electron storage per silicide nanodot was demonstrated in C-V characteristics of MIS capacitors with silicide nanodots FGs.
The Preparation and Optical Property of ZnO Thin-Film by Electrospray
Authors: Ding Yan Huai , Zhang Ping , Jiang Yong , Xu Fu , Chen Jing , Zheng Hua Ling
Published: September 2009

ZnO thin-films were prepared from sol-gel precursors using electrospray method. The structure, morphology and optical property of ZnO thin-films deposited on glass substrates were investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and absorption spectrums (ABS). The surface images obtained directly from AFM showed the compact ZnO films were composed of wurtzite ZnO nanoparticles. The ZnO films presented high optical transmittance in the visible region and strong absorption in ultraviolet region.
Composite Outcomes of Chronically Critically Ill Patients 4 Months After Hospital Discharge
Authors: Daly Barbara J. , Douglas Sara L. , Gordon Nahida H. , Kelley Carol G. , O’Toole E. , Montenegro Hugo , Higgins Patricia
Published: September 2009

Background Data on likely postdischarge outcomes are important for decision making about chronically critically ill patients. It seems reasonable to categorize outcomes into “better” or overall desirable states and “worse” or generally undesirable states. Survival, being at home, and being cognitively intact are commonly identified as important to quality of life and thus may be combined to describe composite outcome states.

Objective To categorize postdischarge outcome states of chronically critically ill patients and identify predictors of better and worse states.

Methods Reanalysis of data from a trial of a disease management program for chronically critically ill patients. Two composite outcomes were created: (1) the “better” outcome: no cognitive impairment at 2 months after discharge and alive and at home at 4 months (ie, met all 3 criteria), and (2) the “worse” outcome: cognitive impairment 2 months after discharge, or death after discharge, or not living at home 4 months after discharge (ie, met at least 1 of these criteria).

Results Of 218 patients not requiring ventilatory support at discharge, 111 (50.9%) had a better outcome. Of 159 patients who were cognitively intact at discharge, 111 (69.8%) had a better outcome. Of the 39 patients who required ventilatory support at discharge, only 1 (3%) achieved the better outcome. Of 98 patients who were cognitively impaired at discharge, only 29 (30%) had the better outcome.

Conclusion Need for mechanical ventilatory support and persistent cognitive impairment at discharge were associated with worse outcomes 4 months after discharge.
Cardiogenic Oscillation and Ventilator Autotriggering in Brain-Dead Patients: A Case Series
Authors: Arbour Richard
Published: September 2009

Brain death is manifested by a flaccid, areflexic patient on assessment of brain function with fixed and dilated pupils at midpoint, loss of consciousness, no response to stimulation, loss of brainstem reflexes, and apnea. A lesion or clinical state responsible for the loss of consciousness must be found. An integral part of clinical evaluation of brain death is apnea testing, which indicates complete loss of brainstem function and respiratory drive. Ventilator triggering or overbreathing the ventilator’s set rate may be considered consistent with intrinsic respiratory drive consequent to residual brainstem function. Ventilator autotriggering, however, may potentially occur in a brain-dead patient as a result of interaction between the hyperdynamic cardiovascular system and compliant lung tissue altering airway pressure and flow patterns. Also, chest wall and pre-cordial movements may mimic intrinsic respiratory drive. Ventilator autotriggering may delay determination of brain death, prolong the intensive care unit experience for patients and their families, increase costs, risk loss of donor organs, and confuse staff and family members. A detailed literature review and 3 cases of cardiogenic ventilator autotriggering are presented as examples of this phenomenon and highlight the value of close multidisciplinary clinical evaluation and examination of ventilator pressure and flow waveforms.
Perioperative Outcomes of Coronary Artery Bypass Grafting: Effects of Metabolic Syndrome and Patient’s Sex
Authors: Brackbill Marcia L. , Sytsma Christine S. , Sykes Kristina
Published: September 2009

Background Perioperative outcome data related to metabolic syndrome in coronary artery bypass graft (CABG) patients are lacking.

Objective To determine the incidence of metabolic syndrome in CABG patients and whether its presence or the patient’s sex affects postoperative lengths of stay in the intensive care unit and hospital.

Methods A retrospective observational study in CABG patients. Risk factors from the Society of Thoracic Surgeons’ Adult Cardiac Surgery Database were used to categorize patients as having metabolic syndrome. Perioperative outcomes were compared between patients with and without metabolic syndrome and between sexes. Outcomes were based on the operational definitions of the Society of Thoracic Surgeons. Results Among 657 patients, 333 had metabolic syndrome; 63.8% (n = 215) of women and 36.9% (n = 118) of men (P ≤ .001). Mean postoperative stays were significantly longer in patients who had metabolic syndrome. Women had longer postoperative stays than did men. Mean postoperative stay for women was 2.7 (SD, 3.4) days in the intensive care unit and 8.2 (SD, 7.1) days in the hospital, compared with 2.0 (SD, 3.8) days in the intensive care unit (P = .01) and 6.6 (SD, 6.8) days in the hospital for men (P = .003). Women with metabolic syndrome also had higher rates of in-hospital death (P = .03).

Conclusion Both female patients and patients with metabolic syndrome undergoing CABG surgery are at higher risk for longer postoperative stays. Women with metabolic syndrome are the CABG patients at highest risk for in-hospital death.
Chlorhexidine, Toothbrushing, and Preventing Ventilator-Associated Pneumonia in Critically Ill Adults
Authors: Munro Cindy L. , Grap Mary Jo , Jones Deborah J. , McClish Donna K. , Sessler Curtis N.
Published: September 2009

Background Ventilator-associated pneumonia is associated with increased morbidity and mortality.

Objective To examine the effects of mechanical (toothbrushing), pharmacological (topical oral chlorhexidine), and combination (toothbrushing plus chlorhexidine) oral care on the development of ventilator-associated pneumonia in critically ill patients receiving mechanical ventilation.

Methods Critically ill adults in 3 intensive care units were enrolled within 24 hours of intubation in a randomized controlled clinical trial with a 2 x 2 factorial design. Patients with a clinical diagnosis of pneumonia at the time of intubation and edentulous patients were excluded. Patients (n = 547) were randomly assigned to 1 of 4 treatments: 0.12% solution chlorhexidine oral swab twice daily, toothbrushing thrice daily, both toothbrushing and chlorhexidine, or control (usual care). Ventilator-associated pneumonia was determined by using the Clinical Pulmonary Infection Score (CPIS).

Results The 4 groups did not differ significantly in clinical characteristics. At day 3 analysis, 249 patients remained in the study. Among patients without pneumonia at baseline, pneumonia developed in 24% (CPIS ≥6) by day 3 in those treated with chlorhexidine. When data on all patients were analyzed together, mixed models analysis indicated no effect of either chlorhexidine (P = .29) or toothbrushing (P = .95). However, chlorhexidine significantly reduced the incidence of pneumonia on day 3 (CPIS ≥6) among patients who had CPIS <6 at baseline (P = .006). Toothbrushing had no effect on CPIS and did not enhance the effect of chlorhexidine.

Conclusions Chlorhexidine, but not toothbrushing, reduced early ventilator-associated pneumonia in patients without pneumonia at baseline.
Heart Rate Variability after Off-Pump versus On-Pump Coronary Artery Bypass Graft Surgery
Authors: Lakusic Nenad , Slivnjak Valentina , Baborski Franjo , Cerovec Dusko
Published: September 2009

Background.It is known that after coronary artery bypass graft surgery (CABG) heart rate variability (HRV) becomes significantly decreased with a gradual recovery in a few months after surgery. However, literature data about the impact of the off-pump CABG on postoperative HRV are not complete. Therefore, the aim of this study was to analyze postoperative value of HRV in CABG patients operated on with off-pump versus on-pump coronary surgery.Methods.This study included 206 consecutive patients who underwent CABG. Sixty six patients (32%) were operated on off-pump while 140 patients (68%) were operated on using the machine for extracorporal circulation. HRV was analyzed from 24-hours Holter electrocardiogram recordings.Results.No significant differences in postoperative values of HRV variables were found between off-pump versus on-pump CABG patients (Mean RR interval 885 106 versus 879 125 ms, standard deviation of all normal R-R intervals 107 30 versus 105 34 ms, NS, total power 2298 2472 versus 2156 1913 ms2, NS).Conclusions.The results of the study showed that there are no differences in HRV few months after surgery between patients operated on with off-pump versus on-pump CABG.
Pneumonia in rural Malawians under five years old: Treatment outcomes and clinical predictors of death on admission
Authors: Lutala Prosper M. , Mzumara Suzgo , Mlenga Maurice , Talipu Raphael , Kasagila Eric
Published: September 2009

Background: High mortality and disability due to pneumonia occur worldwide. The introduction of the Integrated Management of Childhood Illness strategy in Malawi brought with it hope of an improvement in the outcome of pneumonia. However, the risk of death and treatment outcomes remain unknown in many districts.Method: The medical records of 466 consecutive patients admitted to the Mchinji District Hospital from January 2004 to January 2006 whose disease met the World Health Organization criteria for pneumonia were reviewed. Data were collected from forms that had been filled out and different treatment outcomes and determinants of death were analysed using logistic regression.Results: Of the 466 patients, 62.7% completed treatment, 15.9% had unknown outcomes, 12.9% died, 8.4% were lost to follow-up, 0.8% failed to improve with treatment, and 0.4% were transferred to other facilities. Independent predictors of death were: age less than 2 years, female sex, history of pneumonia, chest retractions, type of pneumonia, and central cyanosis.Conclusion: A high proportion of deaths and unknown outcomes occurred among participants. Young age, female sex, history of pneumonia, chest retractions and central cyanosis were associated with death. Mortality from pneumonia may be reduced by close monitoring of these risk factors and by improving health education programmes and communicating these findings to parents and health workers. Further investigations of local reasons for high rates of unknown/unreported outcomes are welcomed.
5‐Hydroxytryptamine Receptor Assays
Authors: Figueroa Katherine W. , Martin Graeme R. , Pulido‐Rios M. Teresa
Published: September 2009

5‐Hydroxytryptamine (5‐HT) receptors, by virtue of their broad expression pattern in peripheral and central tissues, regulate diverse physiological and behavioral responses through the activation of fourteen molecularly distinct receptor subtypes. The tissue‐specific distribution of these receptors confers specificity for the actions of serotonin and highlights the therapeutic potential of serotonin receptor modulators. To better assess this therapeutic potential, it is useful to characterize serotonergic agonists and antagonists in physiologically relevant organ systems. Provided in this unit are twelve tissue bath assays using vascular and smooth muscle tissues isolated from guinea‐pig, rat, and rabbit. These tests make possible the analyses of compounds at nine serotonin receptor subtypes.Curr. Protoc. Pharmacol. 46:4.19.1‐4.19.45. © 2009 by John Wiley & Sons, Inc.
Natural Products as a Foundation for Drug Discovery
Authors: Beutler John A.
Published: September 2009

Natural products have provided chemical leads for the development of many drugs for diverse indications. While most U.S. pharmaceutical firms have reduced or eliminated their in‐house natural product groups, there is a renewed interest in this source of new chemical entities. Many of the reasons for the past decline in popularity of natural products are being addressed by the development of new techniques for screening and production. The aim of this unit is to review current strategies and techniques that increase the value of natural products as a source for novel drug candidates.Curr. Protoc. Pharmacol. 46:9.11.1‐9.11.21. © 2009 by John Wiley & Sons, Inc.
Culture System for Rodent and Human Oligodendrocyte Specification, Lineage Progression, and Maturation
Authors: Espinosa‐Jeffrey Araceli , Wakeman Dustin R. , Kim Seung U. , Snyder Evan Y. , de Vellis Jean
Published: September 2009

Here we document protocols for the production, isolation, and maintenance of the oligodendrocyte phenotype from rodent and human neural stem cells. Our unique method relies on a series of chemically defined media, specifically designed and carefully characterized for each developmental stage of oligodendrocytes as they advance from oligodendrocyte progenitors to mature, myelinating oligodendrocytes. Curr. Protoc. Stem Cell Biol. 10:2D.4.1‐2D.4.26. © 2009 by John Wiley & Sons, Inc.
Culturing Ovarian Somatic and Germline Stem Cells of Drosophila
Authors: Niki Yuzo
Published: September 2009

This unit describes how to collect, culture, and establish stable cell lines of ovarian somatic and germline stem cells of Drosophila. We also describe a protocol for culturing embryonic cells that overexpress growth factors, which serve as a source for conditioned medium. Curr. Protoc. Stem Cell Biol. 10:2E.1.1‐2E.1.9. © 2009 by John Wiley & Sons, Inc.
Reality‐monitoring characteristics in confirmed and doubtful allegations of child sexual abuse
Authors: Roberts Kim P. , Lamb Michael E.
Published: September 2009

According to reality‐monitoring theory, memories of experienced and imagined events are qualitatively different, and can be distinguished by children from the age of 3. Across three studies, a total of 119 allegations of sexual abuse by younger (aged 3–8) and older (aged 9–16) children were analysed for developmental differences in the presence of reality‐monitoring criteria, which should characterise descriptions of experienced events. Statements were deemed likely or unlikely to be descriptions of actual incidents using independent case information (e.g. medical evidence). Accounts by older children consistently contained more reality‐monitoring criteria than those provided by younger children, and age differences were particularly strong when the cases were deemed doubtful (Studies 1 and 2). Copyright © 2009 John Wiley & Sons, Ltd.
Influence of TiO2 Nanoparticles Incorporated into Elastomeric Polyesters on their Biocompatibility In Vitro and In Vivo
Authors: El‐Fray Miroslawa , Piegat Agnieszka , Prowans Piotr
Published: September 2009

Fibroblasts proliferation and apoptosis as well as tissue response after implantation of elastomers containing nanocrystalline TiO2 were investigated in the present in vitro and in vivo study. Materials investigated were soft poly(aliphatic/aromatic‐ester) multiblock thermoplastic elastomers with poly(ethylene terephthalate) (PET) hard segments and dimerized linoleic acid (DLA) soft segments, respectively, containing 0.2 wt% TiO2 nanoparticles. An investigation of the influence of TiO2 nanoparticles incorporated into polymeric material on in vitro biocompatibility revealed enhanced cell proliferation and diminished number of necrotic and apoptotic cells as compared to nanoparticles‐free polymer. Implantation tests indicated that the observed tissue changes were similar to those observed with medical‐grade silicone elastomer, no evidence of contact necrosis being observed. The unchanged morphology of rat liver hepatocytes and the lack of parenchymal necrosis also indicated that exposure to the material containing TiO2 nanoparticles, did not cause any cytotoxic reactions. The present study, thus, showed that elastomeric polyester containing TiO2 nanoparticles are interesting biomimetic constructs for improved tissue regeneration.
Phenotype–genotype correlation in a patient with co‐occurrence of Marfan and LEOPARD syndromes
Authors: Tang Sa , Hoshida Hiroshi , Kamisago Mitsuhiro , Yagi Hisato , Momma Kazuo , Matsuoka Rumiko
Published: September 2009

Here we report on a patient with multiple lentigines, hypertelorism, short stature, arachnodactyly, scoliosis, dissecting aneurysm, hypertrophic cardiomyopathy and developmental delay, and a family history of Marfan syndrome. The patient is affected with both Marfan and LEOPARD syndromes. Mutational screening of the FBN1 gene showed a c.1464T>A (p.C488X) mutation and screening of the PTPN11 gene showed a c.836A>G (p.Y279C) mutation. We conclude that each mutation contributed independently to individual features in the ocular and cardiovascular systems, although short stature was more significantly influenced by the p.Y279C change in PTPN11 rather than the mutation in FBN1. To our knowledge, this is the first report of mutations in both FBN1 and PTPN11 with combined phenotypes of Marfan and LEOPARD syndromes. © 2009 Wiley‐Liss, Inc.
Petty–Laxova–Wiedemann progeroid syndrome: Further phenotypical delineation and confirmation of a rare syndrome of premature aging
Authors: Delgado‐Luengo Wilmer Noé , Petty Elizabeth M. , Solís‐Añez Ernesto , Römel Orlando , Delgado‐Luengo Juana , Hernández María Luisa , Morales‐Machín Alisandra , Borjas‐Fuentes Lisbeth , Zabala‐Fernández William , González‐Ferrer Sandra , Pineda‐Bernal Lennie , Pardo‐Govea Tatiana , Martínez‐Basalo María Caridad , González Richard , Urdaneta Karelis , Cañizales Jenny , Fleitas‐Cabello Herminia
Published: September 2009

A 10‐year‐old boy with manifestations of Petty–Laxova–Wiedemann progeroid syndrome (PLWPS), a rare neonatal progeroid condition, is described and compared with those previously reported. Clinical manifestation include: severe pre‐ and postnatal growth retardation, “progeroid” face, large open fontanelle in infancy, umbilical hernia at birth, pseudomacrocephaly, wide calvaria, sparse scalp hair, markedly diminished subcutaneous fat, scoliosis, partial cutaneous syndactyly, aplastic and hypoplastic distal phalanges with aplasia and hypoplasia of nails, undescended testes, and normal cognitive and motor development. This appears to be one of only a handful of cases of PLWPS reported in an older child or adult. © 2009 Wiley‐Liss, Inc.
Evaluation of C677T and A1298C polymorphisms of the MTHFR gene as maternal risk factors for Down syndrome and congenital heart defects
Authors: Brandalize Ana Paula Carneiro , Bandinelli Eliane , dos Santos Pollyanna Almeida , Roisenberg Israel , Schüler‐Faccini Lavínia
Published: September 2009

Abnormal folate/homocysteine metabolism due to polymorphisms in genes involved in this pathway has been implicated as an etiologic factor in Down syndrome (DS). This case–control study aimed to evaluate the effect of maternal C677T and A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) as risk factors for the development of DS and congenital heart defects (CHD). The distribution of these genotypic variants was similar between mothers of children with DS (n = 239) and control mothers of normal children (n = 197), but the combined genotypes 677CT or TT and 1298AA increased the risk of having offspring with DS (OR = 1.99; 95% CI 1.11–3.55). The presence of the 677T allele in case mothers resulted in a 2.07‐fold higher odds of CHD in the offspring (P < 0.01). Among the 57 mothers of CHD‐affected children with DS who carried the MTHFR 677CT or TT genotypes and did not have periconceptional folic acid intake, we observed a 2.26‐fold increased odds (95% CI 1.25–4.09) of having any CHD‐affected child with DS. Our results show that MTHFR genetic polymorphisms may be involved in the etiology of DS in our population when controlling for age. We noted a borderline significant association for the C677T polymorphism (P = 0.05). Maternal 677T allele may be associated with an increased occurrence of CHD in children with DS and we anticipate that women who carry this polymorphism would benefit from periconceptional folic acid supplementation. © 2009 Wiley‐Liss, Inc.
Solubility and adhesion characteristics of plasma polymerized thin films derived from Lavandula angustifolia essential oil
Authors: Easton Christopher D. , Jacob Mohan V.
Published: September 2009

Integration and implementation of organic polymer thin films often require knowledge of the stability when in contact with solvents and the adhesion quality when applied to different substrates. This article describes the solubility and adhesion characteristics of organic polymer thin films produced from Lavandula angustifolia essential oil, using radio frequency plasma polymerization at four RF power levels. Contact angle data was obtained for various solvents and used to determine the surface tension values for the polymer by using three established methods. A relatively strong electron–donor component and a negligible electronic acceptor component for the polymers indicate that they are monopolar in nature. Solubility data derived from interfacial tension values suggest that the polymers would resist solubilization from the solvents explored. The strongest solvophobic response was assigned to water, whereas diiodomethane demonstrated the weakest solvophobic response, with ΔG121 > 0 in some instances depending on the surface tension values used. The adhesion tests of the polymers deposited on glass, PET, and PS indicated that the adhesion quality of the thin film improved with RF power, and it was associated with an improvement in interfacial bonding. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Prolonged zero‐order BSA release from pH‐sensitive hydrogels of poly(AAc‐co‐DMAPMA) having rich nano through micro scale morphology
Authors: Das Anup , Mehndiratta Mohit , Chattopadhyay Parthaprasad , Ray Alok R.
Published: September 2009

New variety of pH‐sensitive hydrogels, having macroporous interior with honey‐comb type architecture and continuous skin at the surface, have been developed by single step aqueous copolymerization of acrylic acid (AAc) and N‐[3‐(dimethylamino)propyl]‐methacrylamide (DMAPMA) in different feed ratios at 41 ± 1°C. Interlocked nanogels of ∼ 300 nm were identified as the building blocks in all of these cylindrical poly(AAc‐co‐DMAPMA) matrices (PDMAAc). The gels showed good compressive strength even at a swelling as high as 4330% (mass) at pH 7.0. Morphology of McCoy fibroblast cell line remained unchanged in direct contact with different PDMAAc gels, and cell viability (±SD) was recorded to be in the range of 105 (±3)% to 87 (±8)% after 72 h. Bovine serum albumin (BSA) loaded gels were prepared by means of equilibrium partitioning. Loading efficiency of PDMAAc gels has been found to be in the range of 210–277 mg/g dry gel. BSA release from PDMAAc gels at 37°C has been found to follow non‐Fickian diffusion mechanism in simulated gastric juice (pH 1.2), and Case II transport in simulated intestinal juice (pH 7.4). In vitro study showed that the gels are capable of retaining >95% of the loaded BSA in gastric medium through average gastric emptying period. Again, ∼ 56% BSA release was recorded in 24 h at pH 7.4, indicating prolonged BSA diffusion in intestinal condition. Constant rate of BSA diffusion was reflected from the release profiles at both the pH. Diffusion exponents also supported the same and indicated for absolute zero‐order kinetics at pH 7.4. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal property improvement of ethylene‐octene copolymer through the combined introduction of filler and silane crosslink
Authors: Kamphunthong Walailuck , Sirisinha Kalyanee
Published: September 2009

In many applications, e.g., wire and cable insulation, hot water pipe, high‐temperature properties of polymer are essential. This article presents the use of silane crosslinking together with the addition of particular filler in improving the thermal and mechanical properties of ethylene‐octene copolymer (EOC). The effects of filler surface characteristics on siloxane network structure developed and final properties of the crosslinked products are discussed. The results show an increase in the decomposition temperature of EOC more than 50°C after modification. Only crosslinked composites are able to withstand the high‐temperature environment of aging test which is beyond the melting temperature of the matrix polymer. The crosslinked composites filled with calcium carbonate show superior properties to those with silica, due to a higher crosslink density and tighter network structure formed. The silane coupling mechanism and the presence of bound polymer on silica surfaces cause difficulties for the crosslink formation in the silica filled systems. However, an advantageous influence of both silane coupling and crosslink reaction in the silica filled composites is seen on the enhanced tensile strength and modulus of the materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis and characterization of poly(acrylonitrile)/montmorillonite nanocomposites from surface‐initiated redox polymerization
Authors: Chen Chao‐Yen , Chen Chi‐Chang , Hou Sheng‐Shu
Published: September 2009

We have developed a facile method to prepare polyacrylonitrile/montmorillonite (PAN/MMT) nanocomposites using the surface‐initiated redox polymerization of acrylonitrile (AN) in the aqueous phase. The MMT silicate surfaces were first treated with diethanolamine, and the modified MMT (DEA‐MMT) was subsequently used together with the Ce(IV) salt to serve as a redox system. The PAN chains growing on a surface‐tethered DEA expand the interlayer space, and thus lead to intercalated/exfoliated nanocomposites. The nano‐morphology of the prepared nanocomposites depends on the AN/OH molar ratio in feed. An exfoliated PAN/MMT nanocomposite was obtained when the feeding AN/OH molar ratio = 300 was used. The molecular weight of PAN in the nanocomposites prepared by the present method is also dependent on the AN/OH molar ratio in feed and can be up to ca. 160,000 g/mol. The differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA) analyses show that the increasing fraction of exfoliated silicate structures should enhance the contact interface between the silicate and polymer, resulting in the higher glass transition temperature and thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Bond strength/disbonding behavior and dimensional stability of wood materials with different adhesives
Authors: Kurt Şeref , Uysal Burhanettin
Published: September 2009

In this study, we aimed to describe the effects of adhesives [poly(vinyl acetate) (PVAc), Desmodur vinyl trie ketonol acetate, and urea formaldehyde (UF)] on wooden materials (Scotch pine and oriental beech) cut tangentially and radially impregnated with Protim Solignum, chromate copper arsenate (CCA), and Celcure AC 500 and exposed to humidity and water and heat‐resistance, heating, and cooling tests. For the adhesives, the highest swelling (4.3%) was obtained for oriental beech bonded with UF and cut radially, and the lowest swelling (1%) was obtained for Scotch pine bonded with PVAc and cut radially. For the control samples, the humidity‐resistance, water‐resistance, heat‐resistance, and heating and cooling tests decreased the bonding strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
A standby system with two types of repair persons
Authors: Bieth Bruno , Hong Liang , Sarkar Jyotirmoy
Published: September 2009

A continuously monitored one‐unit system, backed by an identical standby unit, is perfectly repaired by an in‐house repair person, if achievable within a random or deterministic patience time (DPT), or else by a visiting expert, who repairs one or all failed units before leaving. We study four models in terms of the limiting availability and limiting profit per unit time, using semi‐Markov processes, when all distributions are exponential. We show that a DPT is preferable to a random patience time, and we characterize conditions under which the expert should repair multiple failed units (rather than only one failed unit) during each visit. We also extend the method when life‐ and repair times are non‐exponential. Copyright © 2009 John Wiley & Sons, Ltd.