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Examining distal humerus morphological variation in Thai individuals using elliptical Fourier analysisBlanton, Amelia Irene 20 February 2021 (has links)
Sexual dimorphism of the distal humerus has been used for the development of morphometric sex estimation methods in human identification. In particular, visual assessment of the olecranon fossa, trochlear shape, and medial epicondyle angle are variably successful in differentiating females and males in African, Asian, and European groups. However, the influence of other factors on the distal humerus has yet to be fully explored. This study utilizes elliptical Fourier analysis (EFA) to examine the shape of these three features for evidence of sexual dimorphism and the effects of age-at-death, stature, and humeral measurements in 261 modern Thai individuals (f=116; m=145), 20-97 years of age. Left humeri were measured, photographed, traced, and analyzed in SHAPE v. 1.3 for EFA. Chi-square, ANOVA, and principal component results indicate sexual dimorphism in the olecranon fossa and trochlear extension shapes, both of which are correlated with epicondylar breadth. Trochlear extension was also found to be correlated with minimum midshaft diameter, vertical head diameter, and stature. The medial epicondyle was not correlated with any of the other factors examined, and age was not correlated with any of the shapes. High rates of intra- and interobserver error were found in the tracings of the three features. While future research should assess methods that better capture the medial epicondyle and improve reliability, features of the distal humerus are sexually dimorphic and somewhat affected by stature and/or body size.
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Effects of comprehensive orthodontic treatment with distalization of maxillary molars on the mandibular dentitionWu, Lihsin 29 July 2020 (has links)
INTRODUCTION: Non-extraction Class II malocclusion treatments often employ the use of maxillary dentition distalization mechanics. The rationale behind these mechanics is to treat the sagittal position of the maxillary dentition to the mandibular dentition. As anchorage loss may occur after distalization of molars, inter-arch mechanics are often used during comprehensive treatment that may manifest in the finish as a more protrusive lower dentition.
OBJECTIVE: To evaluate the efficacy of several distalization modalities, used as part of comprehensive orthodontics, by measuring the overall effects on the dentition and soft tissue.
MATERIALS AND METHODS: Four different modalities of distalization treatment of Class II malocclusion were compared regarding dental and soft tissue changes: Distal Jet (n=26), Horseshoe Jet (n=26), Pendulum (n=26), and the MGBM (Maino, Giannelly, Bernard, Mura) protocol (n=25). The Horseshoe Jet and MGBM methods use miniscrews supported anchorage while the Distal Jet and pendulum do not. The majority of the pendulum subjects (24 of 26) were prescribed headgear wear. For each of the groups, lateral cephalograms were taken before treatment and after comprehensive treatment.
RESULTS: Minimal differences in soft tissue changes between the groups were found; however, significant (p≤0.05) differences in dental changes between groups for lower incisor, upper incisor, and upper first molar sagittal positions were found. Lower incisors showed significant protrusion and proclination for the Distal Jet experimental group (p<0.05). The upper incisor showed the greatest uprighting and retraction (p<0.05) in the pendulum group and the most proclination (p<0.01) in the Horseshoe Jet group.
CONCLUSION: Three out of four experimental groups showed some amount of lower incisor protrusion and/or proclination. Bone anchored modalities had reduced side effects on the lower incisors, with the Horseshoe Jet showing less change than Distal Jet (p=0.05) and the MGBM group showing no significant change. The pendulum group had the greatest upper incisor retraction and showed negligible lower incisor proclination with only 1 out of 6 measurements showing significance.
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An Electrophysiological Study of 2-Hexanone and 2,5-Hexanedione Neurotoxicity in RatsNachtman, Joseph P., Couri, Daniel 01 January 1984 (has links)
n-Hexane and its metabolites are neurotoxic to animals and man. Studies have revealed a progressive neuropathy which affects the distal regions of motor and sensory peripheral nerves. This paper describes efforts to determine whether 2-hexanone or 2,5-hexanedione is more neurotoxic to rats when given in drinking water. Our results show that 2,5-hexanedione is more neurotoxic than 2-hexanone and that it first affects the distal axon. Concentrations of 20 mM produced no effects after 3 weeks but 40 mM increased distal latency after 2 weeks.
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The Physical and Mechanical Aspects of Orthodontic AppliancesBibby, R.E January 1978 (has links)
Magister Scientiae Dentium - MSc(Dent) / These laws were first published in Latin,in 1687.The first law may be literally translated thus, Every body continues in its state of reat or of uniform motion in a straight line ,unless it is compelled to change that state by impressed force. This meano that if a body is at rest it will remain so unless some force acts on it,if in motion ,the velocity of motion must continue uniform unless some force acts to increase it or diminish it. Also the direction of motioA mast continue unchanged and therefom rectilinear unless some force causes it to be diverted.
This law therefore supplies us with a definition of force; Force is that which produces or tends to produce, motion 0.' change of motion.
Newton's second law of motion may be translated as follows:- Newton's second law of motion may be translated as follows:- The change of motion (produced)is proportional to the impressed force producing it,and pursues the direction in which that force is impressed. This law leads to a method of measuring forces. If we change the velocity with which a mass is moving,we also change its momentum. Change in momentum will serve to measure force.lt seems obvious that whatever change in momentum is produced by a force, twice the force will produce twice the change ,etc.i.e. the change is directly proportional to the force. For a given mass,m,change of momentum ,mv,means change of velocity;the change of velocity per unit time is aceeleration,a;the change in momentum per unit time is therefore malf we employ absolute units (poundals or dynes)this can be shown as; Newton's third law of motion states that 'to every action there is an equaI and opposite reaction'.This law recognises the dual aspect of forces It a tooth is pushed by a finger spring ,the spring is also pushed by the tooth,and an eqpal counter force acts towards the spring unti1 the biology of the system intervenes. This dual stress is called pressure.
Retracting incisors against posterior segments it is apparent that the reaction of the posterior segments must be equal and opposite to the incisors.In this case the two forces act away trom each other,and tG this dual stress we give the name tension.
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Föreligger det skillnad i tåtrycksindex före och efter uppvärmning?Elhajj, Leila January 2023 (has links)
Distal tryckmätning är en non-invasiv undersökning som används för att undersöka, diagnostisera och kvantifiera kärlsjukdomar i de perifera extremiteterna. Metoden används för att särskilja olika sjukdomstillstånd i benen. Metoden mäter det systoliska blodtrycket i benens olika nivåer samt i armen. Studien baseras på att placera blodtrycksmanschetter runt höger arm på alla deltagare och runt båda stortårnas innerfalang tillsammans med fotoceller som fästes med dubbelhäftande på tårnas ytterfalang och på tummen. Syftet med studien var att undersöka om skillnad i tåtrycksindex föreligger före och efter uppvärmning av fötterna. Tåtrycksindexet mättes innan uppvärmning och efter uppvärmning, därpå utfördes en till mätning för att undersöka om skillnad erhålls avseende tåtrycksindex. Studien utfördes på avdelningen för Klinisk fysiologi och nuklearmedicin Skånes Universitetssjukhus i Malmö, och den omfattade 20 deltagare, 17 kvinnor och 3 män, utan några exklusionskriterier. Utifrån Q-Q plotvisades rådatan vara normalfördelad. Parat testet indikerade på ett P-värde större än signifikantnivån 0,05, det tyder på ingen skillnad i tåtryck förelåg före och efter uppvärmning. Slutligen för signifikanta skillnader före och efter uppvärmning behöver studien utvecklas genom att i kommande studier inkludera även sjuka patienter.
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FUNCTIONAL BIOMECHANICAL EVALUATION OF MULTIPLE DESIGN PROGRESSIONS OF DISTAL RADIUS VOLAR PLATESAddula, Venkateshwar Reddy January 2007 (has links)
No description available.
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Functional outcome following bone transport reconstruction of distal tibial defectsTwigg, Peter C., Buckley, John, Giannikas, K.A., Wilkes, R.A. January 2005 (has links)
No / Little has been written about the functional outcome of patients treated with bone transport to reconstruct a distal tibial defect. The aim of this study was to investigate the functional capabilities of patients who had undergone reconstruction with distraction osteogenesis for the treatment of a distal tibial defect in one lower limb. At least eighteen months after completion of treatment, eight patients who had no pain and were able to walk and climb stairs without difficulty performed isometric ankle plantar flexion maximum voluntary contractions while the electromyographic activity of the tibialis anterior and triceps surae muscles was simultaneously recorded. Seven of the patients also underwent gait analysis. Data for the involved limb were compared with those collected for the contralateral limb. During gait, stance time (p = 0.01), the plantar flexion angular displacement and peak moment developed during the second half of stance (p < 0.046), and the amount of ankle power generated (p = 0.02) were significantly decreased in the involved limb compared with the contralateral limb. Similar decreases were observed in the plantar flexion (p = 0.01) and dorsiflexion (p = 0.01) maximum voluntary contractions and the corresponding electromyographic activity (p = 0.01). These results suggest that adaptive changes had occurred at the level of the transported muscles, which affected both routine and maximal effort capabilities. These findings contribute to our understanding of the functional limitations of patients who have undergone bone transport with its obligatory shortening of muscle length.
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The Role of Runx1 N-Terminal Splice Isoforms in Hematopoietic DevelopmentHedblom, Emmett E. 01 February 2010 (has links)
Runx1/AML1 transcription factor expression in hematopoietic cell lineages is differentially regulated via usage of two distinct promoters. The 5' UTR and a 19 amino acid encoding sequence transcribed from the distal promoter is inserted via alternative splicing into the 5' end of the mRNA transcript, replacing the 5' UTR and a 5 amino acid encoding sequence usually transcribed from the proximal promoter. Expression of proximal Runx1 in 32Dcl.3 cells delays G-CSF induced neutrophil terminal differentiation by increasing viability compared to distal Runx1. We utilized Runx1 Nterminal deletion and point mutants of three evolutionarily conserved residues to describe dual N-terminal isoform motifs that promote two distinct differentiation phenotypes as regulatory elements in hematopoietic cell differentiation. Runx1 isoforms were evaluated in established hematopoietic in vitro and ex vivo differentiation systems. Deletion of amino acids 3’-14’ (Δ3-14) or 3’-19’ (Δ3-19) of the distal Runx1 N-terminus delayed terminal differentiation of the 32Dcl.3 myeloid cell line, indicating a regulatory motif in distal Runx1 abrogates the delay of terminal differentiation induced by proximal Runx1. Deletion of amino acids 3’-8’ (Δ3-8) or mutation of amino acids serine 3’, serine 5’ and phenylalanine 7’ of the distal Runx1 N-terminus reduce Runx1 expression in the 32Dcl.3 cell line. The N-terminus motif, runt domain and nuclear matrix-targeting sequence of Runx1 modulated Ets1 activity on the KIR3DL1 bidirectional promoter element. The transcription factor YY1 promotes both forward and reverse activation of the KIR3DL1 bidirectional promoter element dominantly in the presence of Runx1, and additively with Ets1. Distinct Runx1 proximal and distal N-termini induced phenotypes were observed in myeloid and thymocyte differentiation, but not with the KIR3DL1 luciferase assay system. This work identifies a previously unknown N-terminal regulatory motif that acts with spatio-temporal and gene target specificity to add another level of control over Runx1 activity during hematopoiesis.
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Recovery of modifiable risk factors at four years following distal radius fracture and their role as predictors of bone mineral density, subsequent falls and osteoporotic fracturesDewan, Neha January 2017 (has links)
Distal radius fracture (DRF) is one of the most common fall-related osteoporotic (OP) fracture
and is an early predictor of subsequent falls and OP fractures among people with DRF. The
majority of older people with DRF present with low bone mineral density (BMD) and there is
often transition to reduced muscle strength, poor balance, fear of falling and physically inactive
lifestyle after fall-related DRF. This thesis consists of three manuscripts which are aimed to
explore the recovery patterns and the role of modifiable risk factors in predicting subsequent
falls, OP fractures and BMD in patients with DRF.
The first manuscript explores the recovery patterns in modifiable risk factors for falls and OP
fractures over four years in patients with DRF. Our study findings showed that patients with
DRF experienced both short-term (6 months) and long-term (4 years) improvement in fracture specific
pain/disability, physical activity, fear of falling, BMD and general health status;
although the majority of the recovery was achieved at six months after DRF.
The second manuscript is a cross-sectional study identifying modifiable risk factors for BMD in
patients with DRF. The unaffected hand grip strength was identified as the independent predictor
of BMD explaining 17% and 12% of total variability in the BMD-femoral neck and BMD-total
hip, respectively. Among age-stratified women with DRF, balance and unaffected hand grip
strength were identified as independent determinants of BMD explaining 10% and 32% of the
total variability in BMD-femoral neck among 50-64 year and 65-80 year old, respectively.
The third manuscript is a longitudinal study identifying modifiable risk factors for subsequent
falls and OP fractures at four years after DRF. The results suggest that nearly 24% of patients
reported one or more subsequent falls (in the last six months) and 19% of patients experienced at
least one subsequent OP fracture after DRF. Patients with poor balance, low BMD, fracture specific
pain/disability of >81 points on patient-rated wrist evaluation questionnaire and presence
of a prior history of multiple falls (≥2) had three times higher odds of subsequent falls. When
adjusted for BMD, age and gender, only prior falls was identified as a significant independent
predictor of subsequent falls. We were not fully powered to explore association of various
modifiable and non-modifiable risk factors with subsequent fractures. However, we found that
patients with osteopenia or osteoporosis had clinically four times higher odds of subsequent OP
fractures than patients with normal BMD. / Thesis / Doctor of Philosophy (PhD) / Wrist fractures are the most common fall-related fragility fractures and often an early indicator of future falls and fractures. This thesis project described recovery patterns in various risk-factors at 4-years after wrist fracture and explored their association with bone mineral density (BMD) and subsequent falls and fractures. We found that the majority of recovery in fracture-specific pain/disability, fear of falling and health-status takes place within six months, although small changes were also noted between 6 months-4 years. People with low unaffected hand grip-strength might have low BMD. Furthermore, people with poor balance, greater fracture-specific pain/disability, osteopenia or osteoporosis and a prior history of multiple falls (≥2) had nearly 3 times higher odds of secondary falls and those with osteopenia or osteoporosis had 4 times higher odds of a secondary fracture. We believe this information will help therapists/clinicians to identify people at risk of future falls/fractures and offer preventive services.
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PREDICTING RISK FOR ADVERSE OUTCOMES FOLLOWING DISTAL RADIUS FRACTUREMehta, Saurabh 04 1900 (has links)
<p>Some individuals remain at risk for adverse outcomes such as chronic wrist/hand pain, falls, and fall-related osteoporotic fractures after distal radius fracture (DRF) remain. This thesis includes five studies that were conducted to establish prediction rules for assessing the risk of these adverse outcomes following DRF.</p> <p>The first manuscript outlines a theoretical framework (RACE - <strong>R</strong>educing pain, <strong>A</strong>ctivating, <strong>C</strong>ognitive reshaping, <strong>E</strong>mpowering) for managing the risk of adverse outcomes, mainly chronic pain, in individuals with DRF. The RACE is one of the first frameworks to suggest a risk-based management approach for individuals with DRF.</p> <p>The Patient-Rated Wrist Evaluation (PRWE) is a condition-specific measure for DRF used in research as well as clinical practice to measure pain and functions in individuals with different wrist/hand injuries. The second manuscript contributes to the literature by providing the first systematic literature review that synthesizes the evidence regarding the psychometric properties of the PRWE. The review determined that the PRWE has excellent reliability, construct validity, and responsiveness in individuals with DRF.</p> <p>The third manuscript indicates that the baseline pain intensity is an independent predictor of chronic pain in individuals with DRF. The results also suggest that the individuals who score ≥35/50 on the pain scale of the PRWE at baseline have 8 times greater risk for developing chronic wrist/hand pain compared to those who score < 35/50.</p> <p>The fourth and fifth manuscripts describe results of a two step study. The fourth manuscript is a structured literature synthesis that identified suitable measures for predicting the risk of falls and fall-related osteoporotic fractures following DRF. The fifth manuscript summarizes the results of preliminary analysis of psychometric properties of selected fall risk measures identified in the fourth manuscript. The fifth manuscript also provides feasibility and sample size requirements for conducting a fall prevention trial in individuals with DRF.</p> / Doctor of Philosophy (PhD)
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