bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic Properties of Substituted Manganese-Tin Spinels
Authors: Gilleo M. A. , Mitchell D. W. 
Published: March 2008

In a Me22+Sn4+O4 spinel, Sn4+ is known to occupy octahedral sites. Therefore manganese-tin spinel, (Mn)[MnSn]O4, would be antiferromagnetic because of the strong interaction between octahedral and tetrahedral ions characteristic of magnetic spinels. The magnetic exchange interaction in a (Mn2+)-O2−-[Mn2+] linkage is of particular interest because it is known to be much weaker than is the case for Fe3+ with which Mn2+ is isoelectronic; magnetic measurements on slightly oxidized Mn-Sn spinel yield a Néel temperature of 58°K.
When the initial equality of the sublattice magnetizations of Mn2+ ions in octahedral and tetrahedral sites is upset by substitution of nonmagnetic, divalent ions, Mg2+ and Zn2+, for Mn2+, spontaneous magnetization appears. The Néel temperature is decreased by these substitutions largely as a consequence of the smaller number of interactions between the reduced number of Mn2+ ions in the two different sites. For equal substitutions for Mn2+ in Mn2SnO4, the moment changes more rapidly in the case of Mg2+ than Zn2+. The moment depends upon the size of the substituent ion because, in this case, the ions involved are spherical and of the same valence. A smaller size of these substituent ions leads to a greater predominance of occupation of the octahedral sites because substitution there increases the Madelung potential both by reduction of lattice constant and increase of oxygen parameter. The sequence, Mg2+, Zn2+, Mn2+, of increasing ionic sizes corresponds to that of increasing lattice constants, 8.60 8.67, 8.88 A, of the respective tin spinels. Substitution of Ge4+ for Sn4+ takes place principally in tetrahedral sites because of the very small size of Ge4+.
Similarly, spontaneous magnetization appears with oxidation of Mn2SnO4. The resultant oxidized manganese ions (presumably Mn3+) are of the same average valence, though of smaller size, than the octahedral ions and, therefore, also appear in octahedral sites. Because Sn4+ is rejected to maintain valence balance, the octahedral sublattice magnetization is increased by oxidation.
Progress in Ultrathin Mo-Permalloy Tapes with Square Hysteresis Loops
Authors: Littmann Martin F. , Ward Chester E. 
Published: March 2008

Commercial production of ultrathin cold-rolled tapes of 4-79 Mo-Permalloy has been accompanied by research on melting, processing, and annealing procedures leading to improved quality control. A wide range of magnetic properties with pulse magnetization is available by selection of tape thickness and final annealing temperature of the cores.
The effect of reduced thickness is a generally higher coercivity and increased squareness. The switching coefficient is lowest for 18 mil tape, but at drives below about 0.25 oe the switching time is not less than for 14 mil because of the higher coercive force.
With increasing temperature of the final anneal, both squareness (measured by static Br/Bm ratio) and coercive force decrease. The decrease in coercive force is accompanied also by a decrease in the switching coefficient until a minimum value of the switching coefficient is reached after which it decreases with further decrease in coercive force. This point of minimum switching coefficient appears to be related to a crystal structure in which the grains extend through the sheet thickness with minimum lateral growth. Data illustrative of the uniformity of static and dynamic magnetic properties between lots of material with present technology are given.
Flux Instrument for Rapid Comparison of Crystal Anisotropies
Authors: Cole R. W. , Honeycutt C. R. 
Published: March 2008

A rotating disk instrument for rapid comparison of crystal anisotropies is described. In it a circular disk rotates in a magnetic field parallel to the place of the disk. Because of crystal anisotropy the magnetization I makes an angle θ with the magnetic intensity H. Some instruments, called torque magnetometers or magnetic torquemeters, measure the torque per unit volume, HI sinθ. In this instrument the disk rotates at 1800 rpm with its axis perpendicular to H.
The changes in I sinθ, the component of the magnetization perpendicular to H, induce an emf in pickup coils, which are placed with their common axis perpendicular to the axis of the rotating disk and perpendicular to H. If the pickup coils are spherical, as in the similar instrument built by Siegel, the ratio of the flux through the coil to the magnetic moment of the specimen can be accurately calculated. Without such an absolute calibration the flux instrument is nevertheless convenient for rapidly comparing the disks of oriented polycrystalline silicon-iron with a single crystal disk of the same dimensions. The standard deviation between percent orientations (relative torque peaks) determined with this flux magnetometer and a conventional torque magnetometer is 3%. The emf from the pickup coils is integrated electronically and displayed on an oscilloscope.
Rotational Hysteresis in Thin Films
Authors: Mayfield J. R. 
Published: March 2008

Rotational losses in films of nickel-iron have been studied over a wide range of frequencies and applied fields by measuring the torque exerted on the films by a rotating magnetic field. Rotational frequencies from 10 cps to 1 mc and field intensities from zero to 100 oe were used with films ranging in nickel content from 70% to 90% and in thickness from 400 A to 12 000 A.
For applied fields less than 2K/M, the observed losses agree well with the theory of rotational hysteresis in materials with uniaxial anisotropy. When combined with standard torque or hysteresis loop data, these losses yield information regarding the uniformity of the effective anisotropy within the sample. In fields considerably greater than 2K/M the loss per cycle for any given sample is found to be independent of the rotational frequency. According to the analysis of Gilbert and Kelly, in which the high-field losses are proportional to the intrinsic damping parameter, these experimental results imply an inverse frequency dependence of the damping parameter. However, correlations between the high-field and the low-field losses, as well as the results of certain auxiliary experiments indicate that the high-field losses are of essentially the same origin as the low-field losses and are not a measure of the intrinsic rotational damping.
Structural and Magnetic Properties of Permalloy Films
Authors: Lloyd J. C. , Smith R. S. 
Published: March 2008

The wall motion coercive force Hc and the rotational coercive force Hr of thin electroplated nickel-iron films are studied as a function of film roughness. Three types of roughness are considered : the first, periodic with a wavelength large compared to a domain wall width and an amplitude small compared with the film thickness; the second, of the order of size of a domain wall; and the third, a substrate roughness that is large compared to the film thickness.
H c was found to be related to film thickness according to Hc = CsD+n. This observation was predicted by Néel, except that his assumption of a form of roughness only of the first kind led to a single value for n of −43. Electron micrographs showed that roughness of the second kind increased with film thickness, indicating that n depends on this factor. Roughness of the third kind, as introduced by unidirectional polishing, results in an increase of Cs, while n and Hr are not affected. This third type of roughness was observed to orient the easy magnetic axis parallel to the polishing grooves.
Stoner-Wohlfarth Calculation on Particle with Both Magnetocrystalline and Shape Anisotropy
Authors: Johnson Clark E. , Brown William Fuller 
Published: March 2008

Previously, it had been assumed that the presence of a minimum of magnetocrystalline anisotropy energy along the long axis of an acicular single-domain particle would increase the coercive force. A theoretical calculation using the Stoner-Wohlfarth model with a magnetocrystalline energy term indicates this is not always true.
For an acicular polycrystalline single-domain particle with cubic magnetocrystalline anisotropy, it is assumed that the crystallites are ordered with the [111] direction parallel to the long axis, and the other directions randomly oriented around this [111] direction.
Carrying out the Stoner-Wohlfarth calculation with various ratios of magnetocrystalline anisotropy to shape anisotropy shows the presence of certain stable states of magnetization which are inaccessible by merely traversing the hysteresis loop. Also, the coercive force of a random agglomerate is related in a complex way to the anisotropy ratio (ratio of crystalline to shape anistropy constants), becoming zero for large values of the anistropy ratio. “Butterfly” hysteresis loops also appear for a wide range of anisotropy ratios.
Millimicrosecond Magnetic Switching and Storage Element
Authors: Meier Donal A. 
Published: March 2008

A magnetic rod suitable for performing the logical switching and storage functions required in a digital computer has been developed. The magnetic element consists of a silver-coated glass rod upon which is electroplated a Fe-Ni alloy several thousand angstroms thick.
A single element for a coincident-current memory requiring two inputs, an inhibit winding, and a sense winding would consist of four separate single layer concentric solenoids wound over the magnetic rod. Memory matrices, each consisting of many solenoids, can be stacked and simultaneously threaded with the rod. The switching speed of the element operating in a coincident-current mode is approximately 70 mμsec. The output voltage generated across a ten-turn sense winding is 200 to 500 mv depending upon the alloy thickness.
The rod is also suitable as a multi-input logical switch. Separate inhibiting windings wound over the rod perform the NOR function of its input literals. A total of thirty separate inhibiting windings have been demonstrated in the laboratory. Satisfactory operation in the 2- to 5-Mc range using transistors in conjunction with the rod has been shown to be practical.
Continuous plating and testing in conjunction with automatic machine winding techniques make the rod appear economically attractive in digital computer applications.
Methamphetamine use among Australian workers and its implications for prevention
Authors: ROCHE ANN M. , PIDD KEN , BYWOOD PETRA , FREEMAN TOBY 
Published: March 2008

AbstractIntroduction and Aims. Little attention has been directed to the use of methamphetamine among Australian workers. To address this, a study was conducted that examined drug consumption patterns of the Australian work‐force. Design and Method. A secondary analysis of the 2004 National Drug Strategy Household Survey (NDSHS) data was undertaken that focused on methamphetamine use among those in paid employment. Results. Methamphetamine use in the past 12 months was reported by 4.0% of workers compared to 2.2% of respondents not in the paid work‐force. A larger proportion of male (4.8%) than female workers (3.0%) used methamphetamine. The highest prevalence occurred among 18–29‐year‐old workers (11.2%; males: 12.6%; females: 9.4%), and among workers in hospitality (9.5%), construction (5.4%) and transport (5.4%) industries and among tradespeople (6.5%). Significantly more methamphetamine users reported absenteeism compared to users of other illicit drugs and non‐drug users. Among respondents reporting methamphetamine use, 13.4% reported absenteeism due to illicit drug use, while 56.8% reported absenteeism due to any illness or injury. Significantly more methamphetamine users (32.9%) reported going to work under the influence than users of other illicit drugs. Compared to users of other illicit drugs, methamphetamine users were also significantly more likely to drive a car, operate heavy machinery or abuse someone while under the influence. Discussion and Conclusions. The specific details of the profile of workers using methamphetamine and the impact it has on work performance allows for the development of targeted interventions and tailored prevention strategies previously not possible.
Reduced liver injury in the interleukin‐6 knockout mice by chronic carbon tetrachloride administration
Authors: Río A. , Gassull M. A. , Aldeguer X. , Ojanguren I. , Cabré E. , Fernández E. 
Published: March 2008

ABSTRACTBackground  Interleukin‐6 has been involved in restoration of liver function after partial hepatectomy and toxic liver injury. However, normal liver regeneration in interleukin‐6 knockout mice has also been reported. The aim of this work was to investigate the effect of interleukin‐6 deficiency on liver injury and its regeneration in a model of long term carbon tetrachloride (CCl4) administration.Design  Serum and whole livers from wild type and interleukin‐6 knockout mice treated with carbon tetrachloride (0·25 mL kg−1) twice a week were obtained after 4, 6 and 8 weeks (n = 4–6). Sections were assessed for liver regeneration, liver injury and hepatocyte apoptosis whereas sera were assayed for aminotransferase levels. Nuclear extracts and total liver lysates were assayed for transcription factor activation and apoptosis related proteins, respectively.Results  When compared to wild type, interleukin‐6 knockout mice showed reduced liver damage scores, lower aminotransferase levels and diminished apoptosis, as well as reduced nuclear factor kappa B activation. Although the level of active protein was lower, activation of signal transducer and activator of transcription 3 still takes place in knockout mice. Furthermore, liver regeneration measured by bromodeoxyuridine incorporation showed no differences between wild type and knockout animals after 6 and 8 weeks of treatment.Conclusions  Compared to the wild type mice liver regeneration after chronic treatment with carbon tetrachloride proceeds at a slower rate in interleukin‐6 deficient mice. However, this low recovery rate is accompanied by a reduction not only in hepatocyte apoptosis, but also in activation of nuclear factor kappa B and liver injury.
Pollen dispersal and genetic structure of the tropical tree Dipteryx panamensis in a fragmented Costa Rican landscape
Authors: HANSON THOR R. , BRUNSFELD STEVEN J. , FINEGAN BRYAN , WAITS LISETTE P. 
Published: March 2008

AbstractIn the face of widespread deforestation, the conservation of rainforest trees relies increasingly on their ability to maintain reproductive processes in fragmented landscapes. Here, we analysed nine microsatellite loci for 218 adults and 325 progeny of the tree Dipteryx panamensis in Costa Rica. Pollen dispersal distances, genetic diversity, genetic structure and spatial autocorrelation were determined for populations in four habitats: continuous forest, forest fragments, pastures adjacent to fragments and isolated pastures. We predicted longer but less frequent pollen movements among increasingly isolated trees. This pattern would lead to lower outcrossing rates for pasture trees, as well as lower genetic diversity and increased structure and spatial autocorrelation among their progeny. Results generally followed these expectations, with the shortest pollen dispersal among continuous forest trees (240 m), moderate distances for fragment (343 m) and adjacent pasture (317 m) populations, and distances of up to 2.3 km in isolated pastures (mean: 557 m). Variance around pollen dispersal estimates also increased with fragmentation, suggesting altered pollination conditions. Outcrossing rates were lower for pasture trees and we found greater spatial autocorrelation and genetic structure among their progeny, as well as a trend towards lower heterozygosity. Paternal reproductive dominance, the pollen contributions from individual fathers, did not vary among habitats, but we did document asymmetric pollen flow between pasture and adjacent fragment populations. We conclude that long‐distance pollen dispersal helps maintain gene flow for D. panamensis in this fragmented landscape, but pasture and isolated pasture populations are still at risk of long‐term genetic erosion.
Complex Fractionated Electrogram Distribution and Temporal Stability in Patients Undergoing Atrial Fibrillation Ablation
Authors: ROUX JEAN‐FRANÇOIS , GOJRATY SATTAR , BALA RUPA , LIU CHRISTOPHER F. , HUTCHINSON MATHEW D. , DIXIT SANJAY , CALLANS DAVID J. , MARCHLINSKI FRANCIS , GERSTENFELD EDWARD P. 
Published: March 2008

Background: Targeting of complex fractionated electrograms (CFEs) has been described as an approach for catheter ablation of atrial fibrillation (AF); however, the distribution and temporal stability of CFE regions remain poorly defined. Methods: In patients with persistent AF referred for ablation, we performed two consecutive left atrial (LA) CFE maps prior to AF ablation. Bipolar electrograms were acquired during AF, and the mean AF cycle length and electrogram voltage were automatically determined at each point. Sites with mean CL ≤120 ms were considered CFE positive. The two maps were then compared qualitatively and quantitatively. Results: A total of 15 patients (93% male, age 56.1 ± 9.0 years) undergoing AF ablation were studied. The two maps were separated in time by 31 ± 10 minutes. There was no significant difference in the number of CFE‐positive regions (12.3 ± 5.2 vs 11.3 ± 4.7; P = 0.06) between the maps. While CFEs were widely distributed within the LA, the PV/left atrial junction (73%) and left atrial appendage (77%) were most often CFE positive. The presence of CFEs at each region was concordant 78% of the time. There was a significant correlation between the two maps (r = 0.35 ± 0.21, range 0.1–0.84; P < 0.001) with a percent difference of 17.5 ± 9.4%. Conclusions: During persistent AF, most CFE regions are found in the vicinity of the PVs. There is a significant correlation between two CFE maps constructed 31 minutes apart, with 78% concordance of CFE sites.
Activation Delay and VT Parameters in Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy: Toward Improvement of Diagnostic ECG Criteria
Authors: COX MONIEK G.P.J. , NELEN MARCEL R. , WILDE ARTHUR A.M. , WIESFELD ANS C. , SMAGT JASPER, Jvd , LOH PETER , CRAMER MAARTEN J. , DOEVENDANS PIETER A. , TINTELEN J. PETER v , De BAKKER JACQUES M.T. , HAUER RICHARD N.W. 
Published: March 2008

Introduction: Desmosomal changes, electrical uncoupling, and surviving myocardial bundles embedded in fibrofatty tissue are hallmarks of activation delay in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Currently, generally accepted task force criteria (TFC) are used for clinical diagnosis. We propose additional criteria based on activation delay and ventricular tachycardia (VT) to improve identification of affected individuals. Methods and Results: Activation delay and VT‐related 12‐lead electrocardiographic (ECG) criteria were studied, while off drugs, in 42 patients with proven ARVD/C according to TFC, and 27 controls with idiopathic VT from the RV outflow tract. Two of three measured TFC could only be identified in a small minority of ARVD/C patients. Additional ECG criteria proposed in this study included (a) prolonged terminal activation duration, an indicator of activation delay; (b) VT with LBBB morphology and superior axis; and (c) multiple different VT morphologies. These criteria were met in 30 (71%), 28 (67%), and 37 (88%) ARVD/C patients, respectively, and in one control patient (P < 0.001). Electrophysiologic studies contributed importantly to yield different VT morphologies. Pathogenic plakophilin‐2 mutations were identified in 25 (60%) of ARVD/C patients and in none of the controls. In ARVD/C patients, parameters measured were not significantly different between mutation carriers and noncarriers, except for negative T waves in V1–3, occurring more frequently in patients with mutation. Conclusions: The proposed additional criteria are specific for ARVD/C and more sensitive than the current TFC. Therefore, adding the newly proposed criteria to current TFC could improve ARVD/C diagnosis, independent of DNA analysis.
The Paradox Dividing Testosterone Deficiency Symptoms and Androgen Assays: A Closer Look at the Cellular and Molecular Mechanisms of Androgen Action
Authors: Carruthers Malcolm 
Published: March 2008

ABSTRACT

Introduction
Central to the diagnosis and treatment of testosterone deficiency syndrome in the adult male is the remarkable paradox that there is a very poor correlation between the characteristic symptoms and levels of serum androgens.

Aim
Because androgen deficiency can be associated with severe symptomatology, as well as diverse conditions such as coronary heart disease, diabetes, and metabolic syndrome, the aim was to present an evidence-based working hypothesis to resolve this confusing clinical paradox.

Methods
A review of the possible mechanisms in testosterone deficiency syndrome was carried out, and a hypothesis to explain this paradox and associated problems in the diagnosis and clinical management of androgen deficiency was established on the basis of a review of the literature.

Main Outcome Measures
The mechanisms by which androgen deficiency could arise were studied at five different levels:

Results
As with insulin in maturity onset diabetes mellitus, there can be both insufficient production and variable degrees of resistance to the action of androgens operating at several levels in the body simultaneously, with these factors becoming progressively worse with aging, adverse lifestyle, other disease processes, and a wide range of medications.

Conclusions
Using this model, androgen deficiency can be redefined as an absolute or relative deficiency of androgens or their metabolites according to the needs of that individual at that time in his life. There are important ways in which the considerations raised by this hypothesis affect the etiology, terminology, diagnosis, and treatment of androgen-deficient states.
“Diagnostic Investigation of the Pelvic Floor”: A Helpful Tool in the Approach in Patients with Complaints of Micturition, Defecation, and/or Sexual Dysfunction
Authors: Voorham-van der Zalm Petra J. , Lycklama à Nijeholt Guus A.B. , Elzevier Henk Willem , Putter Hein , Pelger Rob C.M. 
Published: March 2008

ABSTRACT

Introduction
Pelvic floor dysfunction is recognized to be related to lower urinary tract dysfunction and to lower gastrointestinal symptoms, and is an influential factor in dysfunction and subsequent behavior of the genital system in both men and women. Caregivers should be informed regarding normal pelvic floor function in general and should be able to identify specific aspects of pelvic floor dysfunction in patients with related symptoms. In our hospital, this diagnostic consultation is indicated as Diagnostic Investigation of Pelvic Floor Function (DIPFF).

Aim
This study looked at pelvic floor dysfunction related to specific complaints.

Methods
DIPFF consists of a medical history, a physical examination, including the International Continence Society (ICS) pelvic organ prolapse quantification system in female patients, and a biofeedback registration using a vaginal or anal probe. Based on our experience, we defined an elevated rest tone as greater than 2 µV using intravaginal or intra-anal electromyography.

Main Outcome Measures
Stratification of patients with a single complaint, a combination of two or three complaints of the micturition, defecation or sexual (all compartments of the pelvic floor) resulted in subgroups of respectively 30, 74, and 133 patients.

Results
A total of 238 patients with complaints of micturition, defecation, and/or sexual function were included in this study. Electromyographic analysis revealed an elevated rest tone of the pelvic floor in 141 patients. In 184 patients, we found an involuntary relaxation of the pelvic floor.

Conclusion
In our retrospective study, we found that 77.2% of patients who presented to the clinic with urinary, gastro or sexual complaints had measurable pelvic floor dysfunction (69.3% overactive rest tone and 7.9% under active rest tone). In relation to the ICS terminology, there is a need for a well-defined normal vs. elevated rest tone of the pelvic floor.