A Finite Element Model of the Superior Glenoid Labrum

Despite numerous studies on the function and pathologies of the shoulder joint’s superior glenoid labrum, controversy still exists concerning the mechanism of injury to the superior labral in the anterior to posterior direction (SLAP), and thus the optimal treatment. In this dissertation, the working hypothesis was that it is possible to use finite element models to explore the factors underlying the initiation and propagation of a SLAP lesion. First, the finite element model was validated for studying the tear mechanism in the superior labrum. An area of high strain correlated well with the location of SLAP tears observed clinically. The validated model was then used to evaluate the effect of both superior translation of the humeral head and tension on the long head of the biceps tendon on the strain in the intact labrum. The humeral head motion was found to have relatively greater effect than the biceps tension on the initiation of the SLAP tear. Repetitive micro-trauma or tissue fatigue rather than a single loading event is most likely to cause a mid-substance failure of the labrum. This work also tested the effect of the biceps tension on the propagation of SLAP tears using the finite element model. With loading of the biceps, the model predicted high strains at the edges of the tear suggesting a high risk for progression of the tear. For larger tears, the effect of the biceps was more pronounced. Based on this work, tear size is suggested as one criterion for determining the optimal treatment of the SLAP lesion. During development of the finite element model, simplifying assumptions were necessary. With careful consideration of the effect of these assumptions and simplifications on the results, the current work suggests a plausible mechanism of injury for SLAP lesions. This work is to identify the role of humeral head translation and biceps loading in the initiation and propagation of SLAP tears by examination of the predicted strain.PHDKinesiology and Biomedical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107176/1/ejhwang_1.pd

Effects of biceps tension and superior humeral head translation on the glenoid labrum

We sought to understand the effects of superior humeral head translation and load of the long head of biceps on the pathomechanics of the superior glenoid labrum by predicting labral strain. Using micro‐CT cadaver images, a finite element model of the glenohumeral joint was generated, consisting of humerus, glenoid bone, cartilages, labrum, and biceps tendon. A glenohumeral compression of 50 N and biceps tensions of 0, 22, 55, and 88 N were applied. The humeral head was superiorly translated from 0 to 5 mm in 1‐mm increments. The highest labral strain occurred at the interface with the glenoid cartilage and bone beneath the origin of the biceps tendon. The maximum strain was lower than the reported failure strain. The humeral head motion had relatively greater effect than biceps tension on the increasing labral strain. This supports the mechanistic hypothesis that superior labral lesions result mainly from superior migration of the humeral head, but also from biceps tension. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1424–1429, 2014.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108670/1/jor22688.pd

Effects of biceps tension on the torn superior glenoid labrum

The purpose of this study was to evaluate the role of the tension on the long head of the biceps tendon in the propagation of SLAP tears by studying the mechanical behavior of the torn superior glenoid labrum. A previously validated finite element model was extended to include a glenoid labrum with type II SLAP tears of three different sizes. The strain distribution within the torn labral tissue with loading applied to the biceps tendon was investigated and compared to the inact and unloaded conditions. The anterior and posterior edges of each SLAP tear experienced the highest strain in the labrum. Labral strain increased with increasing biceps tension. This effect was stronger in the labrum when the size of the tear exceeded the width of the biceps anchor on the superior labrum. Thus, this study indicates that biceps tension influences the propagation of a SLAP tear more than it does the initiation of a tear. Additionally, it also suggests that the tear size greater than the biceps anchor site as a criterion in determining optimal treatment of a type II SLAP tear. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1545–1551, 2015.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113101/1/jor22888.pd

Impact Response Comparison Between Parametric Human Models and Postmortem Human Subjects with a Wide Range of Obesity Levels

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138906/1/oby21947_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138906/2/oby21947.pd

Multimodal endoscopic system based on multispectral and photometric stereo imaging and analysis

We propose a multimodal endoscopic system based on white light (WL), multispectral (MS), and photometric stereo (PS) imaging for the examination of colorectal cancer (CRC). Recently, the enhancement of the diagnostic accuracy of CRC colonoscopy has been reported; however, tumor diagnosis for a variety of lesion types remains challenging using current endoscopy. In this study, we demonstrate that our developed system can simultaneously discriminate tumor distributions and provide three-dimensional (3D) morphological information about the colon surface using the WL, MS, and PS imaging modalities. The results demonstrate that the proposed system has considerable potential for CRC diagnosis. © 2019, OSA - The Optical Society. All rights reserved.1

Effects of biceps tension on the torn superior glenoid labrum

The purpose of this study was to evaluate the role of the tension on the long head of the biceps tendon in the propagation of SLAP tears by studying the mechanical behavior of the torn superior glenoid labrum. A previously validated finite element model was extended to include a glenoid labrum with type II SLAP tears of three different sizes. The strain distribution within the torn labral tissue with loading applied to the biceps tendon was investigated and compared to the inact and unloaded conditions. The anterior and posterior edges of each SLAP tear experienced the highest strain in the labrum. Labral strain increased with increasing biceps tension. This effect was stronger in the labrum when the size of the tear exceeded the width of the biceps anchor on the superior labrum. Thus, this study indicates that biceps tension influences the propagation of a SLAP tear more than it does the initiation of a tear. Additionally, it also suggests that the tear size greater than the biceps anchor site as a criterion in determining optimal treatment of a type II SLAP tear. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1545–1551, 2015.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113101/1/jor22888.pd

VLSI implementation of an adaptive equalizer for ATSC digital TV receivers

An adaptive equalizer for ATSC standard HDTV receivers is developed and implemented in VLSI. This equalizer is based on the G-pseudo algorithm that combines the advantages of the decision directed and blind algorithms. It also conducts ghost canceling for the reception of NTSC analog TV signals. A programmable error calculation unit is employed for a flexible implementation of several equalization algorithms. The filter coefficients have a quite long internal word-length for a satisfactory operation in the blind adaptation mode, but only parts of them are used for output calculation to reduce the hardware complexity. The performance of the system for seven GA reference channels is evaluated according to the adaptation algorithms, the number of delays for the adaptation, and the word-length of the filter coefficients. The chip area and power consumption according to the time multiplexing ratio are estimated.This study was supported by the Samsung Electronics, Inc., the Brain Korea 21 Project (0019-19990027) and the National Research Laboratory program (2000–X–7155)

Involvement of p38 Activation and Mitochondria in Death of Human Leukemia Cells Induced by an Agonistic Human Monoclonal Antibody Fab Specific to TRAIL Receptor 1

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces cancer cell death with minimal damage to normal cells; however, some cancer cells are resistant to TRAIL. TRAIL resistance may be overcome by agonistic antibodies to TRAIL receptors. In this study, we report the toxic effects of a novel recombinant agonistic human anti–TRAIL receptor 1 (DR4) monoclonal antibody Fab fragment, DR4-4, on various TRAIL-resistant and -sensitive cancer cell lines. The mechanisms of DR4-4 Fab–induced cell death in a human T cell leukemia cell line (Jurkat) were investigated using cell viability testing, immunoblotting, immunoassays, flow cytometry, and morphological observation. DR4-4 Fab–induced caspase-independent necrosis was observed to occur in Jurkat cells in association with p38 mitogen-activated protein kinase activation, cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein degradation, decreased mitochondrial membrane potential, and increased mitochondrial reactive oxygen species production. Increased cytotoxic effects of DR4-4 Fab were observed in combination with TRAIL or γ-irradiation. Our results indicate that the novel DR4-4 Fab might overcome TRAIL-resistance and induce death in leukemia cells via cellular mechanisms different from those activated by TRAIL. DR4-4 Fab may have application as a potential therapeutic antibody fragment in single or combination therapy for cancer

Parental control and college students' depressive symptoms: A latent class analysis.

We examined how maternal and paternal parental control (helicopter parenting, behavioral control, and psychological control) among college students are related to their depressive symptoms. We collected data from college students who attended a private university in Upstate New York (n = 455) and analyzed it using three-step latent class analysis. Latent class analysis identified four parental control latent classes: weak parental control, strong psychological control, strong helicopter parenting, and strong parental control. College students in the weak parental control class reported lower depressive symptoms than those in strong psychological control and strong parental control classes. In addition, college students in the strong helicopter parenting class reported lower depressive symptoms than those in strong psychological control and strong parental control classes. College students' depressive symptoms were not significantly different between weak parental control and strong helicopter parenting classes. Future researchers are encouraged to continue to acknowledge the characteristics of different forms of parental control and their influence on college students' quality of life in the transition to adulthood, considering the unique approaches of both parents