bluuebunny/crossref_metadata_2025 huggingface dataset:
TEXTURE DEVELOPMENT AND DRAWABILITY OF FRICTIONALLY ROLLED AA 5052 AL ALLOY SHEET
Authors: KIM INSOO , AKRAMOV SAIDMUROD , JEONG HAE BONG , NO TAE KYOUNG
Published: March 2009

The microstructure, pole figure and r -value of the frictionally rolled and subsequently heat treated AA 5052 Al sheets were investigated by optical microscopy, x-ray diffractometer and tensile tester, respectively. Frictionally rolled AA 5052 Al specimens showed a fine grain size. After subsequently heat treated specimens, the ND//<111> texture component was increased. The r -values of the frictionally rolled and subsequently heat treated Al alloy sheets were about two times higher than those of the original Al sheets. These could be related to the formation of ND//<111> texture components through frictional rolling in and subsequent heat treatment of AA 5052 Al sheet.
FINITE ELEMENT ANALYSIS OF THERMAL NANOINDENTATION PROCESS AND ITS EXPERIMENTAL VERIFICATION
Authors: OH HYUN-JUN , LEE EUN-KYUNG , KANG CHUNG-GIL , LEE SANG-MAE
Published: March 2009

In this paper, deformation behavior of Polymethylmethacrylate (PMMA) during thermal indentation was demonstrated by the finite element method using ABAQUS S/W. Forming conditions to reduce the elastic recovery and pile-up were proposed. Thermal nanoindentation experiments were carried out at the temperature range of 110 ~ 150 ° C . The indenter was modeled as a rigid surface. The finite element analysis (FEA) approach is capable of reproducing the loading-unloading behavior for a thermal nanoindentation test and thus comparison between the experimental data and numerical results were demonstrated. The result of the investigation will be applied to the fabrication of the hyper-fine pattern.
CHANGE IN MICROSCOPIC HARDNESS DURING TENSILE PLASTIC DEFORMATION OF POLYCRYSTALLINE ALUMINUM AND TITANIUM
Authors: WANG XIAOQUN , ABE TAKEJI
Published: March 2009

Microscopic hardness on free surface of polycrystalline metal during plastic deformation is closely related to the inhomogeneous deformation in respective grains. Uniaxial tensile tests were carried out on annealed pure aluminum sheet specimens with different averaged grain size and also on annealed pure titanium sheet specimen. The microscopic hardness was measured with the Vickers type micro-hardness testing machine. The increase in micro-hardness is larger at the grain boundary area than the central area of grains. The increase in the hardness is dependent on the averaged grain size of polycrystalline metals. The experimental results are discussed in relation to Hall-Petch relation concerning the grain size dependence of the yield stress or the flow stress.
PREDICTION OF THE RESIDUAL STRESS IN THE PROCESS OF STRAIGHTENING WIRE
Authors: KIM TAE WON , LEE MYOUNG GYU , MOON HYUNG-IL , KIM HYUNG JONG , KIM HEON YOUNG
Published: March 2009

Microwire made using a straightening process has high added value and has been adopted in many fields of industry. There is much active research on the straightening process. Very straight microwire can be obtained by removing the residual stress induced during the manufacturing process. Generally, the residual stress is removed or minimized through several drawing steps with heat treatment. This study used finite element analysis to calculate the residual stress during each straightening process and investigated the main reason for a change in stress.
THERMAL VISCOELASTIC ANALYSIS OF PLASTIC COMPONENTS CONSIDERING RESIDUAL STRESS
Authors: CHOI CHEL WOO , JEOUNG KAB SIK , MOON HYUNG-IL , KIM HEON YOUNG
Published: March 2009

Plastics is commonly used in consumer electronics because of it is high strength per unit mass and good productivity, but plastic components may often become distorted after injection molding due to residual stress after the filling, packing, and cooling processes. In addition, plastic deteriorates depending on various temperature conditions and the operating time, which can be characterized by stress relaxation and creep. The viscoelastic behavior of plastic materials in the time domain can be expressed by the Prony series using the ABAQUS commercial software package. This paper suggests a process for predicting post-production deformation under cyclic thermal loading. The process was applied to real plastic panels, and the deformation predicted by the analysis was compared to that measured in actual testing, showing the possibility of using this process for predicting the post-production deformation of plastic products under thermal loading.
POLARONIC MECHANISM OF SUPERCONDUCTIVITY IN DOPED FULLERIDE SYSTEMS
Authors: TIWARI SURESH CHANDER , KASHYAP ARVIND , SURANA ANIL K. , PALIWAL RADHA K. , KAKANI SHYAM L.
Published: March 2009

A polaronic model of superconductivity in doped fulleride systems is presented. The normal and anomalous one-particle Green's functions are derived for a system with strong electron phonon coupling. The study of collapse of the electron band and the phonon vacuum is presented within the mean-field approximation. Self-consistent equation for the superconductivity order parameter (Δ) is derived using Green's fucntion technique and following Lang and Firsov transformations.

Expressions for specific heat, density of states, free energy and critical field based on this model have been derived. The theory is applied to explain the experimental results in the systems K 3 C 60 and Rb 3 C 60. These results are in good agreement with the available experimental data.
STRESS RELAXATION BEHAVIOR OF IRRADIATED COPPER IN THE TEMPERATURE RANGE 150–300 K
Authors: GHAURI I. M. , AFZAL NAVEED , MUHAMMAD NAWAZ , AHMED SAJJAD
Published: March 2009

The present study reports the stress relaxation behavior of irradiated polycrystalline 5N copper deformed in the temperature range 150 to 300 K. The wire specimens were exposed to an 18 MeV electron beam at room temperature and stress relaxation tests of the specimens were carried out during the tensile test, using universal testing machine between 150 to 300 K. Stress relaxation rate of the specimens was found to decrease with the decrease of test temperature. The decrease of the stress relaxation rate with temperature in irradiated specimens is attributed to the dislocation-defects interaction, which is more pronounced at low temperature due to the reduction in available thermal energy necessary for the relaxation of dislocations.
MULTIPLE SPARK-GENERATED BUBBLE INTERACTIONS
Authors: KHOO BOO CHEONG , ADIKHARI DEEPAK , FONG SIEW WAN , KLASEBOER EVERT
Published: March 2009

The complex interactions of two and three spark-generated bubbles are studied using high speed photography. The corresponding simulations are performed using a 3D Boundary Element Method (BEM) code. The bubbles generated are between 3 to 5 mm in radius, and they are either in-phase or out-of-phase with one another. The possible interaction phenomena between two identically sized bubbles are summarized. Depending on their relative distances and phase differences, they can coalesce, jet towards or away from one another, split into smaller bubbles, or 'catapult' away from one another. The 'catapult' effect can be utilized to generated high speed jet in the absence of a solid boundary or shockwave. Also three bubble interactions are highlighted. Complicated phenomena such as bubble forming an elliptical shape and bubble splitting are observed. The BEM simulations provide insight into the physics of the phenomena by providing details such as detailed bubble shape changes (experimental observations are limited by the temporal and spatial resolution), and jet velocity. It is noted that the well-tested BEM code [1,2] utilized here is computationally very efficient as compared to other full-domain methods since only the bubble surface is meshed.
EFFECT OF BOUNDARY TREATMENT ON PARTICLE SUSPENSION IN MOLECULAR DYNAMICS SIMULATION
Authors: CHEN X.Y. , LIU Y. , YANG J.M. , FAN J.T.
Published: March 2009

There are two conventional boundary treatment methods in molecular dynamics (MD) simulation for particle suspension or fiber in cross flow. One is that the fiber is represented by evenly spaced atoms, the other is that the fiber is treated as one mass point. The calculations with the two boundary treatment methods have been compared, it is found that, with the same properties, both methods could generate slip boundary condition on the fiber surface, however the one mass point method could result in very large slip boundary condition on the fiber surface, and the discrepancy could be as high as 2600%.
NUMERICAL SIMULATION OF MHD FLOWS WITH NON-EQUILIBRIUM CHEMICAL REACTIONS ON UNSTRUCTURED MESHES
Authors: WANG JIANGFENG , WU YIZHAO , CHENG KEMING
Published: March 2009

Two dimensional hypersonic magnetohydrodynamics(MHD) flows with the chemical non-equilibrium effects are numerically simulated using upwind splitting scheme based on unstructured meshes. The governing equations are 2D MHD equations with the chemical components, where 5 species and 17 chemical reactions are considered. The AUSM scheme is implemented in the spatial discretization for the MHD equations, and an explicit 5-stage Runge-Kutta scheme is used for time integration. A loosely coupled approach is used to communicate between the MHD equations and the chemical reaction model. The computational model is a 2D blunt body, around which a dipole magnetic field is located. With hypersonic incoming flows, four different cases are numerically simulated to analyze the effects caused by the magnetic field and/or non-equilibrium chemical reactions. Numerical results are obtained and compared well with available data.
NUMERICAL SIMULATION OF PARACHUTE INFLATION PROCESS USING AN OVERSET DEFORMING GRIDS METHOD
Authors: XIA JIAN , TIAN SHULING , WU YIZHAO
Published: March 2009

A numerical method for the simulation of parachute inflation process is presented in this paper. The unsteady compressible N-S equations are fully coupled with MSD (Mass Spring Damper) structure model and integrated forward in time. The CFD solver is based on an unstructured finite volume algorithm and the preconditioning technique is applied to alleviate the stiffness caused by low Mach number. The Spalart-Allmaras one-equation turbulence model is implemented to evaluate the turbulent viscosity. The whole system (fluid equations and structural model equations) is marched implicitly in time using a dual time stepping method. An overset deforming grids method is adopted in this paper to deal with the very large domain deformation during the parachute inflation process. Finally numerical test is performed to validate the robustness of this method.
LATTICE BOLTZMANN DYNAMICS AND DYNAMICAL SYSTEM SUB-GRID MODELS
Authors: WU CHUI-JIE , GUAN HUI
Published: March 2009

The dynamics sub-grid scale (SGS) models and the dynamical system SGS model are introduced into the lattice Boltzmann method (LBM), and applied to numerical simulation of turbulent cavity flows. The results are compared with those of direct numerical simulation of turbulence and Smagorinsky SGS model. A new average method of eliminating the inherent unphysical oscillation of LBM is also given.
DEWETTING AT THE CENTER OF A DROP IMPACT
Authors: THORODDSEN S. T. , TAKEHARA K. , ETOH T. G.
Published: March 2009

When a drop impacts onto a solid surface, it spreads out into a pancake shape and often forms a dry-spot at the center of the drop. We show that this dewetting at the center is sometimes produced by a small bubble of air which is entrapped on the substrate under the center of the drop. Capillary waves are generated on the surface of the pancake, during the rebounding of the lamellar edge. As these capillary waves converge at the axis of symmetry, their amplitude grows in size until a wave trough touches and merges with the entrapped bubble. This opens up a dry-patch at the center of the splash. We use state-of-the art high-speed video imaging to study this process, for a drop impacting onto a Perspex surface. The imaging is done by looking through the bottom plate to reveal the detailed motions of the capillary waves.
MICROFLUIDIC FLOW-THROUGH REACTOR WITH ELECTROCHEMICAL SENSOR ARRAY FOR REAL-TIME PCR
Authors: TEH HUEY-FANG , RAMALINGAM NAVEEN , GONG HAI-QING , TAN SWEE-NGIN
Published: March 2009

We developed an integrated microfluidic flow-through EC-PCR (EC-PCR) microdevice for the concurrent DNA amplification, PCR products EC detection and PCR products quantification instead of the current available fluorescence detection scheme. The microfluidic flow-through EC-PCR microdevice was fabricated with the state-of-the-art microfabrication technology, by bonding a bottom glass substrate having a microelectrode array to a top glass cover having the microchannels made of PDMS material. Both the amplification of the target DNA sequence and the subsequent EC detection of the PCR products were carried out concurrently on the integrated device by real-time monitoring. The underlying principle of the microfluidic flow-through EC-PCR method was based on the changes of current signal of methylene blue (MB), which worked as an electrochemically active species DNA intercalator in the PCR mixture, during the amplification process at the extension phase. The results shown in this work indicated that the nucleic acid analysis could be performed in a fast thermal cycling and true real-time quantitative electrochemical detection. The signal variation trends of the EC detection and the fluorescence detection were the same in our verification measurements for both methods, which suggested that the EC detection method was feasible for this application.
INVESTIGATION ON THE REYNOLDS NUMBER EFFECT ON FLOW ASYMMETRY OVER SLENDER BODIES AT HIGH INCIDENCE
Authors: WANG YUANJING , FAN ZHAOLIN , LI HAO
Published: March 2009

Investigation of Reynolds number effect on flow asymmetry over slender bodies at high incidence was conducted. Results show that increasing of wind velocity affects flow asymmetry by changing the intensity of the vortices; Model scale affects the distance between the main vortices, which determines the stability of the vortices and results in the discrepancy in the flow asymmetry over different scale models.
EXPERIMENTAL INVESTIGATION ON A PITCHING MOTION DELTA WING IN UNSTEADY FREE STREAM
Authors: SHI ZHIWEI , MING XIAO
Published: March 2009

As combat aircraft becomes more and more maneuverable, the need to understand the unsteady behavior of aircraft in dynamic flow fields becomes more important. Usually researchers pay more attention to the effects on the changes of AOA, but ignore the effects of velocity variations. It is known that the velocity of aircraft changes greatly when the aircraft undergoes a high angle of attack maneuver, like "cobra" maneuver. To completely simulate and study the effect of rapid changes in both free stream velocity and angle of attack, a pitching motion setup is developed in the unsteady wind tunnel of NUAA. By measuring unsteady loads, unsteady pressure distribution and flow visualization, the unsteady aerodynamic behavior of a pitching isolated delta wing and the pitching delta wing coupled with unsteady free stream are investigated. It is found that the oscillating free stream velocity affects the hysteresis characteristics of the pitching delta wing further. The pressure distribution and flow visualization measurements show that the changes in the structure of the leading-edge vortices are the main reason. These studies conclude that a good understanding of the unsteady aerodynamics is vitally important in the design of super-maneuverable aircraft.
NUMERICAL RESEARCH ON THE EFFECT OF FIBERS ON THE PROPERTY OF TURBULENT FIBER SUSPENSION IN A CHANNEL
Authors: SHEN SUHUA , LIN JIANZHONG
Published: March 2009

To explore the rheological property in turbulent channel flow of fiber suspensions, the equation of probability distribution function for mean fiber orientation and the Reynolds averaged Navier-Stokes equation with the term of additional stress resulted from fibers were solved with numerical methods to get the distributions of the mean velocity and turbulent kinetic energy. The simulation results show that the effect of fibers on turbulent channel flow is equivalent to an additional viscosity. The turbulent velocity profiles of fiber suspension become gradually sharper by increasing the fiber concentration and/or decreasing the Reynolds number. The turbulent kinetic energy will increase with increasing Reynolds number and fiber concentration.
MODELING OF PEM FUEL CELLS WITH FINITE-THICKNESS CATALYSTS
Authors: YIN JIANG HUI , CAO JUN
Published: March 2009

A general proton exchange membrane fuel cell model including two finite-thickness catalysts is developed in this study, allowing for an in-depth understanding of the effects of the two key electrochemical reactions taking place in the two catalysts. The model is used to predict the performances of fuel cells employing two different flow channel designs, providing insights for fuel cell design and performance optimization.
THE TRANSIENT DEFORMATION OF RED BLOOD CELLS IN SHEAR FLOW
Authors: LOW H. T. , SUI Y. , CHEW Y. T. , ROY P.
Published: March 2009

The transient deformation of red blood cells (RBCs) in a shear flow is studied by a three-dimensional numerical model proposed by the present authors. The RBCs are approximated by ghost cells consisting of Newtonian liquid drops enclosed by Skalak membranes. The RBCs have an initially biconcave discoid resting shape, and the internal liquid is assumed to be the same to the fluid outside. The simulation is based on a hybrid method, in which the immersed boundary concept is introduced into the framework of the lattice Boltzmann method, and a finite element model is incorporated to obtain the forces acting on the nodes of the cell membrane which is discretized into flat triangular elements. The dynamic motion of RBCs is investigated in simple shear flow under a broad range of shear rates. At large shear rates, the present results show that the cells carry out a swinging motion, in which periodic inclination-oscillation and shape deformation superimpose on the membrane tank treading motion. With the shear rate decreasing, the swinging amplitude of the cell increases, and finally triggers a transition to tumbling motion.
Renal ischemia-reperfusion injury upregulates histone-modifying enzyme systems and alters histone expression at proinflammatory/profibrotic genes
Authors: Zager Richard A. , Johnson Ali C. M.
Published: March 2009

Ischemic renal injury can produce chronic renal inflammation and fibrosis. This study tested whether ischemia-reperfusion (I/R) activates histone-modifying enzyme systems and alters histone expression at selected proinflammatory/profibrotic genes. CD-1 mice were subjected to 30 min of unilateral I/R. Contralateral kidneys served as controls. At 1, 3, or 7 days of reflow, bilateral nephrectomy was performed. Renal cortices were probed for monocyte chemoattractant protein-1 (MCP-1), transforming growth factor-β1 (TGF-β1), and collagen III mRNAs and cytokine levels. RNA polymerase II (Pol II) binding, which initiates transcription, was quantified at exon 1 of the MCP-1, TGF-β1, collagen III genes (chromatin immunoprecipitation assay). Two representative gene-activating histone modifications [histone 3 lysine 4 (H3K4) trimethylation (m3) (H3K4m3); histone 2 variant H2A.Z] were sought. Degrees of binding of two relevant histone-modifying enzymes (Set1, BRG1) to target genes were assessed. Renal cortical Set1, BRG1, and H2A.Z mRNAs were measured. Finally, the potential utility of urinary mRNA concentrations as noninvasive markers of these in vivo processes was tested. I/R caused progressive increases in Pol II binding to MCP-1, TGF-β1, and collagen III genes. Parallel increases in cognate mRNAs also were expressed. Progressive increases in renal cortical Set1, BRG1, H2A.Z mRNAs, and increased Set1/BRG1 binding to target genes occurred. These changes corresponded with: 1) progressive elevations of H3K4m3 and H2A.Z at each test gene; 2) increases in renal cortical TGF-β1/MCP-1 cytokines; and 3) renal collagen deposition (assessed by histomorphology). Postischemic increases in urinary TGF-β1, MCP-1, Set1, and BRG1 mRNAs were also observed. We conclude that: 1) I/R upregulates histone-modifying enzyme systems, 2) histone modifications at proinflammatory/profibrotic genes can result, and 3) urinary mRNA assessments may have utility for noninvasive monitoring of these in vivo events.
Development of vascular renin expression in the kidney critically depends on the cyclic AMP pathway
Authors: Neubauer Björn , Machura Katharina , Chen Min , Weinstein Lee S. , Oppermann Mona , Sequeira-Lopez Maria Luisa , Gomez R. Ariel , Schnermann Jürgen , Castrop Hayo , Kurtz Armin , Wagner Charlotte
Published: March 2009

During metanephric kidney development, renin expression in the renal vasculature begins in larger vessels, shifting to smaller vessels and finally remaining restricted to the terminal portions of afferent arterioles at the entrance into the glomerular capillary network. The mechanisms determining the successive expression of renin along the vascular axis of the kidney are not well understood. Since the cAMP signaling cascade plays a central role in the regulation of both renin secretion and synthesis in the adult kidney, it seemed feasible that this pathway might also be critical for renin expression during kidney development. In the present study we determined the spatiotemporal development of renin expression and the development of the preglomerular arterial tree in mouse kidneys with renin cell-specific deletion of Gsα, a core element for receptor activation of adenylyl cyclases. We found that in the absence of the Gsα protein, renin expression was largely absent in the kidneys at any developmental stage, accompanied by alterations in the development of the preglomerular arterial tree. These data indicate that the maintenance of renin expression following a specific spatiotemporal pattern along the preglomerular vasculature critically depends on the availability of Gsα. We infer from our data that the cAMP signaling pathway is not only critical for the regulation of renin synthesis and secretion in the mature kidney but that it also is critical for establishing the juxtaglomerular expression site of renin during development.
Tuning to Interaural Time Difference and Frequency Differs Between the Auditory Arcopallium and the External Nucleus of the Inferior Colliculus
Authors: Vonderschen Katrin , Wagner Hermann
Published: March 2009

Barn owls process sound-localization information in two parallel pathways, the midbrain and the forebrain pathway. Exctracellular recordings of neural responses to auditory stimuli from far advanced stations of these pathways, the auditory arcopallium in the forebrain and the external nucleus of the inferior colliculus in the midbrain, demonstrated that the representations of interaural time difference and frequency in the forebrain pathway differ from those in the midbrain pathway. Specifically, low-frequency representation was conserved in the forebrain pathway, while it was lost in the midbrain pathway. Variation of interaural time difference yielded symmetrical tuning curves in the midbrain pathway. By contrast, the typical forebrain-tuning curve was asymmetric with a steep slope crossing zero time difference and a less-steep slope toward larger contralateral time disparities. Low sound frequencies contributed sensitivity to contralateral leading sounds underlying these asymmetries, whereas high frequencies enhanced the steepness of slopes at small interaural time differences. Furthermore, the peaks of time-disparity tuning curves were wider in the forebrain than in the midbrain. The distribution of the steepest slopes of best interaural time differences in the auditory arcopallium, but not in the external nucleus of the inferior colliculus, was centered at zero time difference. The distribution observed in the auditory arocpallium is reminiscent of the situation observed in small mammals. We speculate that the forebrain representation may serve as a population code supporting fine discrimination of central interaural time differences and coarse indication of laterality of a stimulus for large interaural time differences.
The Effect of Media on Children
Authors: Oakes J. Michael
Published: March 2009

This paper considers the media research with children from a social epidemiological perspective. I am especially concerned with comparing the types of research designs, standard measures and modeling frameworks used in media studies to those used in (social) epidemiology and prevention research more generally. Overall, the state of research on the effect of various media on outcomes in children is robust and promises to be on par with the best epidemiological research. The principal measurement deficiency lies in the measurement of potential confounders and effect modifiers. With respect to research designs, the principal deficiencies include neglect of effect-modification by recognized social groupings, contextual influences and social interaction. Substantial practical benefits may come from the implementation and evaluation of intervention programs, especially group-randomized trials. As for analyses, the principal weakness appears to be in extending causal inference into observational field studies.
Growth and Tolerance of Healthy Term Infants Receiving Hydrolyzed Infant Formulas Supplemented With Lactobacillus rhamnosus GG: Randomized, Double-Blind, Controlled Trial
Authors: Scalabrin Deolinda M. , Johnston William H. , Hoffman Dennis R. , P'Pool Virginia L. , Harris Cheryl L. , Mitmesser Susan H.
Published: March 2009

Healthy, term infants received extensively hydrolyzed casein formula (EHF; control), the same formula supplemented with Lactobacillus rhamnosus GG (EHF-LGG), or partially hydrolyzed whey:casein (60:40) formula supplemented with LGG (PHF-LGG), in this double-blind, randomized, controlled, parallel, prospective study. Anthropometric measures and 24-hour dietary and tolerance recalls were obtained at 30, 60, 90, 120, and 150 days of age. Blood collected in a subset of infants was analyzed for fatty acid profiles in plasma and red blood cells and for markers of allergic sensitization. Adverse events were recorded throughout the study. Growth rates were not statistically different between EHF and PHF-LGG and between EHF and EHF-LGG from day 14 to day 30, 120, or 150. No relevant differences in formula tolerance, adverse events, or allergic and immune markers were demonstrated between groups. The extensively and partially hydrolyzed formulas supplemented with LGG support normal growth in healthy, term infants and are well tolerated and safe.
Preparation and Properties of Wood Plastic Composites Made of Recycled High-density Polyethylene
Authors: Nourbakhsh Amir , Ashori Alireza
Published: March 2009

This article deals with experimental investigation of composites based on recycled high-density polyethylene (RHDPE) and poplar fibers (Populus deltoids) formed by air-forming and hot-pressing. The effects of the fiber content (55, 70, and 85 wt%) and compatibilizing agent (0, 2, and 4 wt%) concentration on the mechanical properties and water absorption were evaluated. The use of polyethylene-grafted maleic anhydride (PE-g-MA) improved the compatibility between the fiber and RHDPE. Adding PE-g-MA at 2 and 4 wt% in the composite formulation significantly improved both the stability and mechanical properties. The tensile strength of the composites containing PE-g-MA was superior to those of the composites without compatibilizing agent. As expected, the flexural of the composites increased with the wood content. Low internal bond strength was observed for the panels with different fiber loading and compatibilizing agent content in our study.
An Examination of Content Preference in Offender Profiles
Authors: Norris Gareth , Rafferty Emma , Campbell Jacqueline
Published: March 2009

This study examined preferences for the content of offender profiles between two different groups of participants to assess the importance of presentation style and linguistic emphasis. The sample consisted of 70 undergraduate psychology students and 30 serving police officers who were each presented with a case study and three profiles constructed to represent three stylistically different representations of the offender. The accompanying questionnaire indicated significant differences in the profile selection between police officers and students, and also, more important, some disparity in the way these preferences are articulated and justified. Detailed analysis of results and suggestions for future research are also included.
Axial Linear Patellar Displacement
Authors: Urch Scott E. , Tritle Benjamin A. , Donald Shelbourne K. , Gray Tinker
Published: March 2009

Background

The tools for measuring the congruence angle with digital radiography software can be difficult to use; therefore, the authors sought to develop a new, easy, and reliable method for measuring patellofemoral congruence.

Hypothesis

The linear displacement measurement will correlate well with the congruence angle measurement.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

On Merchant view radiographs obtained digitally, the authors measured the congruence angle and a new linear displacement measurement on preoperative and postoperative radiographs of 31 patients who suffered unilateral patellar dislocations and 100 uninjured subjects. The linear displacement measurement was obtained by drawing a reference line across the medial and lateral trochlear facets. Perpendicular lines were drawn from the depth of the sulcus through the reference line and from the apex of the posterior tip of the patella through the reference line. The distance between the perpendicular lines was the linear displacement measurement. The measurements were obtained twice at different sittings. The observer was blinded as to the previous measurements to establish reliability. Measurements were compared to determine whether the linear displacement measurement correlated with congruence angle.

Results

Intraobserver reliability was above r2 = .90 for all measurements. In patients with patellar dislocations, the mean congruence angle preoperatively was 33.5°, compared with 12.1 mm for linear displacement (r2 = .92). The mean congruence angle postoperatively was 11.2°, compared with 4.0 mm for linear displacement (r2 = .89). For normal subjects, the mean congruence angle was —3° and the mean linear displacement was 0.2 mm.

Conclusion

The linear displacement measurement was found to correlate with congruence angle measurements and may be an easy and useful tool for clinicians to evaluate patellofemoral congruence objectively.
Measurement of Glenohumeral Internal Rotation in Asymptomatic Tennis Players and Swimmers
Authors: Rangel Torres Renato , Ellera Gomes João Luiz
Published: March 2009

Background

Glenohumeral internal rotation deficit, often diagnosed in players of overhead sports, has been associated with the development of secondary shoulder lesions.

Hypothesis

Asymptomatic players of different overhead sports will exhibit variable degrees of glenohumeral internal rotation deficit.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Fifty-four asymptomatic male volunteers (108 shoulders) divided into 3 groups (tennis players, swimmers, control group) underwent measurements of glenohumeral internal and external rotation using clinical examination with scapular stabilization. Measurements of dominant and nondominant shoulders were compared within and between groups. Glenohumeral internal rotation deficit (GIRD) was defined as the difference in internal rotation between the nondominant and dominant shoulders.

Results

In tennis players, mean GIRD was 23.9° ± 8.4° (P < .001); in swimmers, 12° ± 6.8° (P < .001); and in the control group, 4.9° ± 7.4° (P = .035). Dominant shoulders showed significant difference between all groups, and the difference in internal rotation of the dominant shoulder between the group of tennis players in comparison with the control group (27.6°, P < .001) was greater than the difference in internal rotation of the dominant shoulder found in the group of swimmers compared with the control group (17.9°, P < .001). Between tennis players and swimmers, the difference in internal rotation of the dominant shoulder was 9.7° (P = .002).

Conclusion

Dominant limbs showed less glenohumeral internal rotation than the nondominant limbs in all groups, with the deficit in the group of tennis players about twice the deficit found for swimmers. Mean difference between limbs in the control group was less than 5°, which is within normal parameters according to most studies. There were statistically significant differences between all groups when dominant shoulders were compared with each other, differences that were not compensated by external rotation gain. Tennis players had the least range of motion, followed by swimmers.
The Reliability, Validity, and Responsiveness of the Lysholm Score and Tegner Activity Scale for Anterior Cruciate Ligament Injuries of the Knee
Authors: Briggs Karen K. , Lysholm Jack , Tegner Yelverton , Rodkey William G. , Kocher Mininder S. , Steadman J. Richard
Published: March 2009

Background

In 1982, the Lysholm score was first published as a physician-administered score in the American Journal of Sports Medicine. The Tegner activity scale was published in 1985.

Hypothesis

The Lysholm and Tegner scores are valid as patient-administered scores and responsive at early time points after treatment of anterior cruciate ligament tears.

Study Design

Cohort study (Diagnosis); Level of evidence, 1.

Methods

All patients were treated for an anterior cruciate ligament tear. For responsiveness, the Lysholm score (n = 1075) and Tegner activity level (n = 505) were measured preoperatively and 6, 9, 12, and 24 months postoperatively. For test-retest (n = 50), scores were measured at 2 years postoperatively and again within 4 weeks by questionnaire. For criterion validity (n = 170), patients completed the Short Form-12 and the International Knee Documentation Committee score in addition to Lysholm and Tegner instruments. For all other analyses, preoperative Lysholm score (n = 1783) or Tegner activity levels (n = 687) were collected.

Results

There was acceptable test-retest reliability for both the Lysholm (intraclass correlation coefficient = 0.9) and Tegner (intraclass correlation coefficient = 0.8) scores. The minimum detectable change for Lysholm was 8.9 and for Tegner was 1. The Lysholm demonstrated acceptable internal consistency. The Lysholm correlated with the International Knee Documentation Committee (r = .8) and the Short Form-12 (r = .4), and Tegner correlated with the Short Form-12 (r = .2). Both scores had acceptable floor and ceiling effects and all hypotheses were significant. The Lysholm and Tegner were responsive to change at each of the time points.

Conclusion

After 25 years of changes in treatment of anterior cruciate ligament injuries, the Lysholm knee score and the Tegner activity scale demonstrated acceptable psychometric parameters as patient-administered scores and showed acceptable responsiveness to be used in early return to function after anterior cruciate ligament treatment.
Biomechanical Comparison of Single-Tunnel—Double-Bundle and Single-Bundle Anterior Cruciate Ligament Reconstructions
Authors: Gadikota Hemanth R. , Seon Jong Keun , Kozanek Michal , Oh Luke S. , Gill Thomas J. , Montgomery Kenneth D. , Li Guoan
Published: March 2009

Background

Anatomic double-bundle reconstruction has been thought to better simulate the anterior cruciate ligament anatomy. It is, however, a technically challenging procedure, associated with longer operation time and higher cost.

Hypothesis

Double-bundle anterior cruciate ligament reconstruction using a single femoral and tibial tunnel can closely reproduce intact knee kinematics.

Study Design

Controlled laboratory study.

Methods

Eight fresh-frozen human cadaveric knee specimens were tested using a robotic testing system to investigate the kinematic response of the knee joint under an anterior tibial load (130 N), simulated quadriceps load (400 N), and combined torques (5 N·m valgus and 5 N·m internal tibial torques) at 0°, 15°, 30°, 60°, and 90° of flexion. Each knee was tested sequentially under 4 conditions: (1) anterior cruciate ligament intact, (2) anterior cruciate ligament deficient, (3) single-bundle anterior cruciate ligament reconstruction using quadrupled hamstring tendon, and (4) single-tunnel—double-bundle anterior cruciate ligament reconstruction using the same tunnels and quadrupled hamstring tendon graft as in the single-bundle anterior cruciate ligament reconstruction.

Results

Single-tunnel—double-bundle anterior cruciate ligament reconstruction more closely restored the intact knee kinematics than single-bundle anterior cruciate ligament reconstruction at low flexion angles (≤30°) under the anterior tibial load and simulated muscle load (P < .05). However, single-tunnel—double-bundle anterior cruciate ligament reconstruction overconstrained the knee joint at high flexion angles (≥60°) under the anterior tibial load and at 0° and 30° of flexion under combined torques.

Conclusion

This double-bundle anterior cruciate ligament reconstruction using a single tunnel can better restore anterior tibial translations to the intact level compared with single-bundle anterior cruciate ligament reconstruction at low flexion angles, but it overconstrained the knee joint at high flexion angles.

Clinical Relevance

This technique could be an alternative for both single-bundle and double-tunnel—double-bundle anterior cruciate ligament reconstructions to reproduce intact knee kinematics and native anterior cruciate ligament anatomy.
Working Across the Divide
Authors: Word Jessica , Sung Min Park
Published: March 2009

Job involvement is a principal factor in the lives of most people; employees in the workplace are mentally and emotionally influenced by their degree of involvement in work. Using the data from the National Administrative Studies Project III, this study empirically compares the level of job involvement between managers in the public and nonprofit sectors and explores different aspects including demographic, managerial, and institutional factors that contribute to the apparent differences. The results of the study indicate that the mean level of nonprofit managers' job involvement is significantly greater than for public managers. Each sector had specific variables that significantly and uniquely contributed to job involvement. Overall, the results suggest a need to more fully investigate the various mechanisms and functions of situational and organizational contexts, organizational norms, and culture that were associated with job involvement regardless of sector. Implications and limitations of this research are also discussed.
Design of Clinical Trials of Analgesic Drugs
Authors: Huskisson E.C.
Published: March 2009

Analgesia is a popular subject for clinical research for several reasons. First, there are many patients who experience pain and therefore there is no shortage of clinical material. Secondly, there are many methods of pain relief to study, including a large number of drugs. Finally, most drugs act quickly, usually within 30-60 min, and have a relatively short action of 4-6 h, so that other treatments can be compared when the pain returns.

Clinical trials of analgesic drugs need three important ingredients: a model, an experimental design and a method of measurement.
Case Report Pericardial Complication of Neuropsychiatric Systemic Lupus Erythematosus
Authors: Sarkar David , Taylor J.L. , Hoffbrand B.I.
Published: March 2009

A 28-year-old woman presenting with systemic lupus erythematosus stuck two sewing needles into her pericardium while psychotic from cerebral lupus. We believe this is a unique cause of acute pericarditis as a complication of SLE.
Epitopes on β2-GPI recognized by anticardiolipin antibodies
Authors: Koike T , Ichikawa K , Kasahara H , Atsumi T , Tsutsumi A , Matsuura E
Published: March 2009

Anticardiolipin antibodies (aCL) found in sera from patients with antiphospholipid syndrome recognize a cryptic epitope that appears on the β2-glycoprotein I (β2-GPI) molecule when β2-GPI interacts with a lipid membrane composed of negatively charged phospholipid or when β2-GPI is adsorbed on a polyoxygenated polystyrene plate. A homology based model of β2-GPI was constructed based on the NMR coordinates of sushi domains of human factor H. The conformation was like a cylinder consisting of five domains, its IV and V domains being glued by electrostatic interaction. We used phage-displayed random peptide libraries to search the epitopes of human aCL. Structures similar to consensus sequences selected by a biopanning method was found on domain IV of β2-GPI.
Many faces of lupus anticoagulants
Authors: Triplett DA
Published: March 2009

Lupus anticoagulants (LA) are immunoglobulins which inhibit one or more of the in-vitro phospholipid (PL) dependent tests of coagulation. Virtually any physician may encounter LA-positive patients. Such patients present with a variety of diagnostic challenges including arterial and venous thromboembolic events, recurrent fetal loss, TIAs, livedo reticularis, etc. LA and anticardiolipin antibodies (ACA) are the most common cause of acquired thrombophilia. Consequently, it is imperative for clinicians and laboratorians to work together in establishing the diagnosis of LA/ACA. The laboratory diagnosis of LA requires careful adherence to the SSC Subcommittee on Lupus Anticoagulants/Phospholipid-dependent Antibodies guidelines. Four sequential steps are required, including: screening tests, mixing studies (to establish the presence of an inhibitor), confirmatory tests based on increased or altered PL concentrations, and ruling out other coagulopathies (for example, factor VIII inhibitor).
Anti-prothrombin antibodies and their relation with thrombosis and lupus anticoagulant
Authors: De Groot PG , Horbach DA , Simmelink MJA , Van Oort E , Derksen RHWM
Published: March 2009

Antiphospholipid antibodies are a heterogeneous group of antibodies, comprising antibodies with different antigen specificity. Prothrombin is one of the antigens which can be detected by antiphospholipid antibodies and therefore anti-prothrombin antibodies belong to the antiphospholipid antibody family. The presence of antiphospholipid antibodies correlates strongly with thromboembolic complications; however a mechanism by which these autoantibodies induce a thrombotic complication in vivo is not understood. The classic assays for the detection of antiphospholipid antibodies (LAC and anticardiolipin ELISAs) aim to measure all the antiphospholipid antibodies present in the samples without making a distinction between the different subspecificities of the antibodies present in one single sample. Moreover, most of the in-vitro studies performed were carried out with total IgGs, which contain a mixture of antibodies. The absence of an accurate characterization of the plasma samples and the lack of specificity of the IgGs used in in-vitro tests makes it difficult to determine the contribution of antiprothrombin antibodies to the thrombotic complications. Here we review and critically analyse the literature regarding the clinical relevance of the presence of antiprothrombin antibodies and the possible participation of these antibodies in the pathogenesis of the thrombotic complications.
Placental pathology in antiphospholipid syndrome
Authors: Levy RA , Avvad E , Oliveira J , Porto LC
Published: March 2009

One of the major targets of antiphospholipid antibodies (aPL) is the placenta, the evolution of which during pregnancy has been well documented. Histopathological findings are related to gestational age, and several physiologic and pathologic alterations that occur during its development. The major findings in placentae from aPL positive patients are thrombosis, acute atherosis, a decreased number of syncytio-vascular membranes, increased number of syncytial knots and obliterative arteriopathy. These findings are not specific to the antiphospholipid syndrome (APS) and sometimes do not correlate with the fetal outcome. Histopathological study of placentae may elucidate mechanisms of action of aPL in fetal loss and other obstetric complications. In addition, it may assist in the investigation of the differential diagnosis between APS and pregnancy-induced hypertension. Immunohistochemical studies of local placental proteins contribute to this differential diagnosis.
Treatment of antiphospholipid syndrome in pregnancy
Authors: Cowchock S
Published: March 2009

Women with antiphospholipid antibodies (aPL = IgG anticardiolipin and/or lupus anticoagulants) and a history of either prior thrombotic events or pregnancy loss are at high risk during pregnancy for either another fetal death or thrombosis. The treatment of choice is anticoagulation with heparin. Both standard unfractionated heparin and low-molecular-weight heparin are used for prophylactic anticoagulation during pregnancy. The half-lives of either standard heparin, or low-molecular-weight heparin, and the peak values for each after subcutaneous injection, are lower than those in nonpregnant patients. Doses and injection intervals need to be adjusted when treating a pregnant woman. Clotting tests such as the activated partial thromboplastin time (aPTT) vary greatly during pregnancy, and the aPTT is often not even prolonged when antithrombotic levels of heparin are achieved. The aPTT is not a useful test when the patient has a lupus anticoagulant. Levels of plasma heparin are therefore needed to best care for pregnant women who need anticoagulation—even for prophylaxis. Low-dose aspirin is often added empirically to heparin for treatment of aPL during pregnancy, but its efficacy has not been evaluated. Intravenous infusions of gamma globulins (IVGG) have been used as additional therapy when prior treatment with heparin during pregnancy failed to save the fetus, when severe and early onset preeclampsia has complicated a prior pregnancy (in such cases efficacy is unproven), or when there is an additional medical complication (such as immune thrombocytopenia) for which IVGG is an appropriate treatment. There are some situations in which treatment with corticosteroids is the best, or the only choice. However, corticosteroids should not be combined with heparin for long-term treatment during pregnancy because the risk for vertebral fracture is so high.
Methods for subtyping lupus anticoagulants
Authors: Exner T
Published: March 2009

Two simple procedures were tested for their potential to identify β2-glycoprotein 1 (β2GPl) or prothrombin cofactor dependence among lupus anticoagulants (LA). The first comprised mixing test plasma 1:4 with β2GP1-deficient plasma instead of with normal plasma. β2GPl deficiency decreased, but did not abolish most LA detectable in KCT, DRVVT and APTT clotting tests. Mixing 1:4 with bovine plasma was evaluated in a second test based on the KCT in the expectation that prothrombin-dependent LA would be preferentially shortened. Bovine plasma had a similar correcting effect on LA in all three tests considered here. Conversely, a prothrombin antibody was found to have similar prolonging effect on all three of these tests. LA patient plasmas displayed considerable heterogeneity when analysed using a combination of these two tests. The clinical significance of these tests remains uncertain. DRVVT and KCT tests do not appear to discriminate β2GP1-dependent from prothrombin-dependent LA.