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Full-Text Articles in Engineering

Evaluation Of A Patient-Specific Cost Function To Predict The Influence Of Foot Path On The Knee Adduction Torque During Gait, B. J. Fregly, Jeffrey A. Reinbolt, T. L. Chmielewski Jan 2008

Evaluation Of A Patient-Specific Cost Function To Predict The Influence Of Foot Path On The Knee Adduction Torque During Gait, B. J. Fregly, Jeffrey A. Reinbolt, T. L. Chmielewski

Jeffrey A. Reinbolt

osteoarthritis (OA). Though foot path changes (e.g. toeing out) can reduce the adduction torque, no method currently exists to predict whether an optimal foot path exists for a specific patient. This study evaluates a patient-specific optimization cost function to predict how foot path changes influence both adduction torque peaks. Video motion and ground reaction data were collected from a patient with knee OA performing normal, toe out, and wide stance gait. Joint and inertial parameters in a dynamic, 27 degree-of-freedom, full-body gait model were calibrated to the patient’s normal gait data. The model was then used in gait optimizations that …


Microfluidic Devices For Terahertz Spectroscopy Of Biomolecules, P. A. George, W. Hui, F. Rana, Benjamin G. Hawkins, A. E. Smith, B. J. Kirby Jan 2008

Microfluidic Devices For Terahertz Spectroscopy Of Biomolecules, P. A. George, W. Hui, F. Rana, Benjamin G. Hawkins, A. E. Smith, B. J. Kirby

Benjamin G. Hawkins

We demonstrate microfluidic devices for terahertz spectroscopy of biomolecules in aqueous solutions. The devices are fabricated out of a plastic material that is both mechanically rigid and optically transparent with near-zero dispersion in the terahertz frequency range. Using a low-power terahertz time-domain spectrometer, we experimentally measure the absorption spectra of the vibrational modes of bovine serum albumin from 0.5–2.5 THz and find good agreement with previously reported data obtained using large-volume solutions and a high-power free-electron laser. Our results demonstrate the feasibility of performing high sensitivity terahertz spectroscopy of biomolecules in aqueous solutions with detectable molecular quantities as small as …


Understanding Prediction Systems For Hla-Binding Peptides And T-Cell Epitope Identification, L. You, P. Zhang, M. Boden, V. Brusic Oct 2007

Understanding Prediction Systems For Hla-Binding Peptides And T-Cell Epitope Identification, L. You, P. Zhang, M. Boden, V. Brusic

Ping Zhang

Peptide binding to HLA molecules is a critical step in induction and regulation of T-cell mediated immune responses. Because of combinatorial complexity of immune responses, systematic studies require combination of computational methods and experimentation. Most of available computational predictions are based on discriminating binders from non-binders based on use of suitable prediction thresholds. We compared four state-of-the-art binding affinity prediction models and found that nonlinear models show better performance than linear models. A comprehensive analysis of HLA binders (A*0101, A*0201, A*0301, A*1101, A*2402, B*0702, B*0801 and B*1501) showed that non-linear predictors predict peptide binding affinity with high accuracy. The analysis …


Importance Of Preswing Rectus Femoris Activity In Stiff-Knee Gait, M. D. Fox, Jeffrey A. Reinbolt, A. S. Arnold, S. Ounpuu, S. L. Delp Aug 2007

Importance Of Preswing Rectus Femoris Activity In Stiff-Knee Gait, M. D. Fox, Jeffrey A. Reinbolt, A. S. Arnold, S. Ounpuu, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.


Predicting Outcomes Of Treatment For Stiff-Knee Gait Using Supervised Learning, Jeffrey A. Reinbolt, M. D. Fox, M. H. Schwartz, S. L. Delp Aug 2007

Predicting Outcomes Of Treatment For Stiff-Knee Gait Using Supervised Learning, Jeffrey A. Reinbolt, M. D. Fox, M. H. Schwartz, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.


E-Infinity Theory And The Higgs Field, Ji-Huan He Jan 2007

E-Infinity Theory And The Higgs Field, Ji-Huan He

Ji-Huan He

E-Infinity theory predicts nine more elementary particles to be discovered in a standard model including the Higgs bosons. In addition a Higgs field is supposed to endow the particles with mass. This field must interact with the three nongravitational forces, i.e., the electromagnetic force, the weak force, and the strong force, therefore we could have four spin zero massive Higgs particles, namely two neutral ( and ) and two charged (H+ and H−), all a part from the spin 2 massless graviton. Considering the possibility of fractional charge, we might have four additional quasi-particles (H+1/3, H−1/3, H+2/3 and H−2/3) similar …


Mathematical Models For Continuous Electrospun Nanofibers And Electrospun Nanoporous Microspheres, Ji-Huan He, Lan Xu, Yue Wu, Yong Liu Jan 2007

Mathematical Models For Continuous Electrospun Nanofibers And Electrospun Nanoporous Microspheres, Ji-Huan He, Lan Xu, Yue Wu, Yong Liu

Ji-Huan He

Abstract: A brief review of mathematical models of electrospinning is given. The nano-effect and electrospinning dilation are presented to explain how to prepare extremely high strength continuous nanotibers and nanoporous microspheres, respectively. According to the established models, vibration-electrospinning is introduced to improve electrospinability, Siro-electrospinning is suggested to mimic the spinning procedure of a spider and magneto-electrospinning is used to control the instability arising in the electrospinning process. A new theory linked to both classical mechanics and quantum mechanics should be developed to explain certain special phenomena in electrospinning. E-infinity theory is considered to be a potential theory to deal with …


Twenty-Six Dimensional Polytope And High Energy Spacetime Physics, Ji-Huan He, Lan Xu, Li-Na Zhang, Xu-Hong Wu Jan 2007

Twenty-Six Dimensional Polytope And High Energy Spacetime Physics, Ji-Huan He, Lan Xu, Li-Na Zhang, Xu-Hong Wu

Ji-Huan He

We give the exact geometrical shape and study the combinatorial properties of higher dimensional polytopes for the dimensions from n = 4 to n = 12 as well n = 26 relevant to Heterotic, M and F superstring theories. Connections to E-infinity theory and the holographic principles are also discussed


Solitary Solutions, Periodic Solutions And Compacton-Like Solutions Using The Exp-Function Method, Xu-Hong Wu, Ji-Huan He Jan 2007

Solitary Solutions, Periodic Solutions And Compacton-Like Solutions Using The Exp-Function Method, Xu-Hong Wu, Ji-Huan He

Ji-Huan He

Abstract In this paper, the Exp-function method is used for seeking solitary solutions, periodic solutions, and compacton-like solutions of nonlinear differential equations. The combined KdV–MKdV equation and the Liouville equation are chosen to illustrate the effectiveness and convenience of the proposed method.


Electrospinning Of High-Molecule Peo Solution, Yu-Qin Wan, Ji-Huan He, Jian-Yong Yu, Yue Wu Jan 2007

Electrospinning Of High-Molecule Peo Solution, Yu-Qin Wan, Ji-Huan He, Jian-Yong Yu, Yue Wu

Ji-Huan He

Electrospinning is a simple but powerful method for making nanofibers that can then be collected to create porous mats. We expand the range of this technique by making nanofibers from macromolecules with a molecular weight of 3,000,000, namely poly(ethylene oxide) (PEO). Gelation of PEO blocks its spinning by traditional electrospinning. PEO was mixed with pure alcohol, and in specific concentration 10 wt % and under vibration condition, the mixed solution behaves like polymers for electrospinning, the average diameter of the obtained nanofibers is about 100 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3840-3843, 2007


Electrospinning: The Big World Of Small Fibers, Ji-Huan He Jan 2007

Electrospinning: The Big World Of Small Fibers, Ji-Huan He

Ji-Huan He

Similar to the nuclear age, the so-called nanoage is coming, the growing gap between nano haves and nano have-nots, however, will remain, as has global competition, particularly from the electrospinning technology.


Are Patient-Specific Joint And Inertial Parameters Necessary For Accurate Inverse Dynamics Analyses Of Gait?, Jeffrey A. Reinbolt, R. T. Haftka, T. L. Chmielewski, B. J. Fregly Jan 2007

Are Patient-Specific Joint And Inertial Parameters Necessary For Accurate Inverse Dynamics Analyses Of Gait?, Jeffrey A. Reinbolt, R. T. Haftka, T. L. Chmielewski, B. J. Fregly

Jeffrey A. Reinbolt

Variations in joint parameter (JP) values (axis positions and orientations in body segments) and inertial parameter (IP) values (segment masses, mass centers, and moments of inertia) as well as kinematic noise alter the results of inverse dynamics analyses of gait. Three-dimensional linkage models with joint constraints have been proposed as one way to minimize the effects of noisy kinematic data. Such models can also be used to perform gait optimizations to predict post-treatment function given pre-treatment gait data. This study evaluates whether accurate patient- specific JP and IP values are needed in three-dimensional linkage models to produce accurate inverse dynamics …


Design Of Patient-Specific Gait Modifications For Knee Osteoarthritis Rehabilitation, B. J. Fregly, Jeffrey A. Reinbolt, K. L. Rooney, K. H. Mitchell, T. L. Chmielewski Jan 2007

Design Of Patient-Specific Gait Modifications For Knee Osteoarthritis Rehabilitation, B. J. Fregly, Jeffrey A. Reinbolt, K. L. Rooney, K. H. Mitchell, T. L. Chmielewski

Jeffrey A. Reinbolt

Gait modification is a nonsurgical approach for reducing the external knee adduction torque in patients with knee osteoarthritis (OA). The magnitude of the first adduction torque peak in particular is strongly associated with knee OA progression. While toeing out has been shown to reduce the second peak, no clinically realistic gait modifications have been identified that effectively reduce both peaks simultaneously. This study predicts novel patient-specific gait modifications that achieve this goal without changing the foot path. The modified gait motion was designed for a single patient with knee OA using dynamic optimization of a patient-specific, full-body gait model. The …


Investigating Stiff-Knee Gait With Subject-Specific Simulations, Jeffrey A. Reinbolt, M. D. Fox, S. L. Delp Oct 2006

Investigating Stiff-Knee Gait With Subject-Specific Simulations, Jeffrey A. Reinbolt, M. D. Fox, S. L. Delp

Jeffrey A. Reinbolt

No abstract provided.


Simulation-Based Treatment Planning For Knee Osteoarthritis, B. J. Fregly, Jeffrey A. Reinbolt Sep 2006

Simulation-Based Treatment Planning For Knee Osteoarthritis, B. J. Fregly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.


Benefits Of Automatic Differentiation For Biomechanical Optimizations, Jeffrey A. Reinbolt, B. J. Fregly Jun 2006

Benefits Of Automatic Differentiation For Biomechanical Optimizations, Jeffrey A. Reinbolt, B. J. Fregly

Jeffrey A. Reinbolt

No abstract provided.


Evaluation Of A Patient-Specific Cost Function To Predict The Influence Of Foot Path On The Knee Adduction Torque During Gait, B. J. Fregly, Jeffrey A. Reinbolt, B. I. Koh, T. L. Chmielewski Mar 2006

Evaluation Of A Patient-Specific Cost Function To Predict The Influence Of Foot Path On The Knee Adduction Torque During Gait, B. J. Fregly, Jeffrey A. Reinbolt, B. I. Koh, T. L. Chmielewski

Jeffrey A. Reinbolt

No abstract provided.


Predicting Patient-Specific Gait Modifications For Knee Osteoarthritis Rehabilitation, B. J. Fregly, Jeffrey A. Reinbolt, K. L. Rooney, K. H. Mitchell, T. L. Chmielewski Mar 2006

Predicting Patient-Specific Gait Modifications For Knee Osteoarthritis Rehabilitation, B. J. Fregly, Jeffrey A. Reinbolt, K. L. Rooney, K. H. Mitchell, T. L. Chmielewski

Jeffrey A. Reinbolt

No abstract provided.


A Modified Hodgkin–Huxley Model, Ji-Huan He Jan 2006

A Modified Hodgkin–Huxley Model, Ji-Huan He

Ji-Huan He

A modified Hodgkin–Huxley model is suggested by taking into account the size effect of ionic channels.


An Evaluation Of Osteoporosis Prevalence In Spinal Cord Disabled Veterans, Hossein Gholizadeh Jan 2006

An Evaluation Of Osteoporosis Prevalence In Spinal Cord Disabled Veterans, Hossein Gholizadeh

Hossein Gholizadeh

DANESHVAR MEDICINE; DECEMBER 2006-JANUARY 2007; 14(66);37-44. AN EVALUATION OF OSTEOPOROSIS PREVALENCE IN SPINAL CORD DISABLED VETERANS SHOJAEI H.,SOROUSH M.R.,MODIRIAN E.,GHOLIZADEH H. Introduction: Osteoporosis and bone fracture risk due to decrease in bone mineral density is known as one of the most important complications of chronic spinal cord injuries (SCI). It also is a major health problem among the patients in SCI society. Although immobilization, old age, menopause and some comorbiditing, are major causes, other important factors also should be taken into consideration. Materials & Method: In this cross-sectional study, 132 veterans with SCI (mean of age 37.4 years), underwent dual-energy …


Application Of E-Infinity Theory To Biology, Ji-Huan He Jan 2006

Application Of E-Infinity Theory To Biology, Ji-Huan He

Ji-Huan He

Albert Einstein combined continuous space and time into his special relativity, El-Naschie discovered the transfinite discontinuity of space–time in his E-infinity theory where infinity of dimensions was created. We find a partner of both space–time and E-infinity in biology. In our theory, the number of cells in an organism endows an additional dimension in biology, leading to explanation of many complex phenomena.


Application Of E-Infinity Theory To Biology, Ji-Huan He Jan 2006

Application Of E-Infinity Theory To Biology, Ji-Huan He

Ji-Huan He

Albert Einstein combined continuous space and time into his special relativity, El-Naschie discovered the transfinite discontinuity of space–time in his E-infinity theory where infinity of dimensions was created. We find a partner of both space–time and E-infinity in biology. In our theory, the number of cells in an organism endows an additional dimension in biology, leading to explanation of many complex phenomena.


Predicted Gait Modifications To Reduce The Peak Knee Adduction Torque, B. J. Fregly, K. L. Rooney, Jeffrey A. Reinbolt Jul 2005

Predicted Gait Modifications To Reduce The Peak Knee Adduction Torque, B. J. Fregly, K. L. Rooney, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.


Creation Of Patient-Specific Dynamic Models From Three-Dimensional Movement Data Using Optimization, Jeffrey A. Reinbolt, B. J. Fregly Jul 2005

Creation Of Patient-Specific Dynamic Models From Three-Dimensional Movement Data Using Optimization, Jeffrey A. Reinbolt, B. J. Fregly

Jeffrey A. Reinbolt

No abstract provided.


Regional Osteoporosis In The Spinal Cord Of Disabled War Veterans, Hossein Gholizadeh Jan 2005

Regional Osteoporosis In The Spinal Cord Of Disabled War Veterans, Hossein Gholizadeh

Hossein Gholizadeh

Introduction: Osteoporosis, the result of an imbalance between bone resorption and bone formation, is a potential problem for patients with spinal cord injury (SCI) because of immobility commonly associated with this impairment. Bone mineral content decreases by 25% to 50% and the magnitude of this reduction is dependent on the level, completeness and duration of SCI. This study was designed to evaluate osteoporosis in war veterans with SCI in Isfahan province. Methods: In this cross-sectional study, by use of a cluster sampling frame, SCI veterans underwent-dualenergy X-ray absorptiometry (DEXA) to define bone mineral density (BMD) in 2nd to 4th lumbar …


Evaluation Of The Particle Swarm Algorithm For Biomechanical Optimization, J. F. Schutte, B. I. Koh, Jeffrey A. Reinbolt, B. J. Fregly, R. T. Haftka, A. D. George Jan 2005

Evaluation Of The Particle Swarm Algorithm For Biomechanical Optimization, J. F. Schutte, B. I. Koh, Jeffrey A. Reinbolt, B. J. Fregly, R. T. Haftka, A. D. George

Jeffrey A. Reinbolt

Optimization is frequently employed in biomechanics research to solve system identification problems, predict human movement, or estimate muscle or other internal forces that cannot be measured directly. Unfortunately, biomechanical optimization problems often possess multiple local minima, making it difficult to find the best solution. Furthermore, convergence in gradient-based algorithms can be affected by scaling to account for design variables with different length scales or units. In this study we evaluate a recentlydeveloped version of the particle swarm optimization (PSO) algorithm to address these problems. The algorithm’s global search capabilities were investigated using a suite of difficult analytical test problems, while …


Parallel Decomposition Methods For Biomechanical Optimization, B. I. Koh, Jeffrey A. Reinbolt, B. J. Fregly, A. D. George Mar 2004

Parallel Decomposition Methods For Biomechanical Optimization, B. I. Koh, Jeffrey A. Reinbolt, B. J. Fregly, A. D. George

Jeffrey A. Reinbolt

No abstract provided.


Estimation Of Body Segment Parameters From Three-Dimensional Gait Data Using Optimization, B. J. Fregly, Jeffrey A. Reinbolt Mar 2004

Estimation Of Body Segment Parameters From Three-Dimensional Gait Data Using Optimization, B. J. Fregly, Jeffrey A. Reinbolt

Jeffrey A. Reinbolt

No abstract provided.


Zu-Gengs Axiom Vs Cavalieris Theory, Ji-Huan He Jan 2004

Zu-Gengs Axiom Vs Cavalieris Theory, Ji-Huan He

Ji-Huan He

No abstract provided.


Allometric Scaling And Instability In Electrospinning, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu Jan 2004

Allometric Scaling And Instability In Electrospinning, Ji-Huan He, Yu-Qin Wan, Jian-Yong Yu

Ji-Huan He

The regulation of scale and bifurcation-like instability in electrospinning are intriguing and enduring problems after the technology was invented by Formhals in 1934. Regulatory mechanisms for controlling the radius of electrospun fibers are clearly illustrated in the different states. Generally, the relationship between radius r of jet and the axial distance z from nozzle can be expressed as an allometric equation of the form , the values of the scaling exponent (b) for the initial steady stage, instability stage, and terminal stage are respectively –1/2, –1/4, and 0. Allometry in economy, biology, turbulence, astronomy, neural resistance, conductive textile, and macromolecule …