Contextualização: Uma das formas de conhecimento da função muscular se dá por meio de modelos biomecânicos que utilizam parâmetros como área de secção transversa fisiológica (ASTF), comprimento de fascículo e ângulo de penação para a mensuração da força isométrica máxima dos músculos. Os modelos biomecânicos normalmente empregam arquitetura de cadáveres e ignoram as características específicas da população estudada. Por esta razão, podem ser imprecisos na estimativa. Objetivo: Comparar o torque isométrico máximo de extensão de joelho de mulheres com mais de 55 anos com a estimativa de torque utilizando modelo biomecânico, utilizando parâmetros de cadáveres e utilizando parâmetros musculares mensurados diretamente. Metodologia: Quinze voluntárias com idade superior a 55 anos realizaram contrações voluntárias máximas isométricas (CVMI) de extensão de joelho em quatro ângulos (15°, 45°, 75° e 105°). Foram coletadas imagens de ultrassonografia de ASTF, comprimento de fascículo e ângulo de penação dos músculos do quadríceps. Esses parâmetros foram utilizados no modelo de Arnold et al. (2010) para estimar o torque individual das voluntárias nas mesmas condições da CVMI.. Os resultados de torque experimental, torque estimado individual (arquitetura individual) e torque estimado genérico (arquitetura dos cadáveres) foram comparados por meio de ANOVA de Friedman (α<0,05) e desdobramento post-hoc de Wilcoxon, índice de significância corrigido de α<0,0167 foi adotado após correção de Bonferroni. Além disso, foi realizada a análise gráfica de Bland-Altman (1986), regressão linear, índice de correlação intraclasse (ICC) e erro RMS para identificar qual técnica se assemelha mais ao torque experimental. Resultados e Discussão: O torque estimado individualmente previu corretamente o torque experimental nos ângulos de 45°, 75° e 105°. O torque estimado genérico previu corretamente o torque experimental nos ângulos 75° e 105°. Ambas as estimativas apresentaram tendências de superestimar os valores experimentais. Sendo que o torque estimado individual apresentou menor erro RMS e menor ICC. Após a correção da distância perpendicular muscular utilizada no modelo pela apresentada por Krevolin, Pandy e Pearce (2004) para mulheres, o pico do torque estimado individualmente apresentou-se no mesmo ângulo do torque coletado (75°). Conclusão: A estimativa com dados de arquitetura individualizados aumenta o grau acerto da técnica em um dos ângulos coletados, entretanto, a correlação entre os dados experimentais e aqueles oriundos do modelo individualizado não foi maior que aquela obtida entre os dados experimentais e os dados oriundos do modelo genérico. / Background: One way to know the muscle function is by biomechanical models that use parameters such as physiological cross-sectional area (PCSA) , fascicle length and penation angle for the estimation maximum isometric muscle force. Biomechanical models typically employ generic architecture parameters from cadaveric studies and ignore the specific characteristics of the studied population. For this reason, the estimation may be inaccurate. Objective: Compare the maximum isometric knee extension moment in women over 55 years with the estimated moment using a biomechanical model, using: (1) muscle parameters from cadaveric studies and (2) muscle parameters measured directly. Methods: Fifteen volunteers aged over 55 years did maximum isometric voluntary contraction (MIVC) of knee extension at four angles (15°, 45°, 75° and 105°). Ultrasound images of PCSA, fascicle length and penation angle of the quadriceps femoris muscles were acquired. These parameters were used in the model of Arnold et al. (2010) to estimate the individual voluntary moment of the same conditions of MIVC. The experimental moments were compared with the estimated moment and with generic architecture, collected from cadaveric studies (Ward et al., 2009). The results experimental moment, individual estimated moment (individual architecture) and generic estimated moment (architecture from cadavers form Ward et al., (2009)) were compared using Friedman's ANOVA (α<0.05) and Wilcoxon’s post-hoc (α<0.0167 - Bonferroni’s correction). Furthermore, the following analysis were performed: graphical analysis and Bland-Altman (1986), linear regression, intraclass correlation coefficient (ICC) and RMS error to identify which technique is more similar to the experimental moment. Results and Discussion: The moment estimated individually correctly predicted the experimental moment at 45°, 75° and 105°. The generic moment estimation agreed with the experimental moment at 75° and 105°. Both estimations presented tendencies to overestimate the experimental moment. The individual estimation presented lower RMS error and lower ICC. After correction of the muscle moment arm used in the model for the presented by Krevolin , Pandy and Pearce (2004 ), the peak angle of estimated moment was presented at the same angle of the experimental moment (75°). Conclusion: The estimate with individualized data architecture increases the degree of agreement in one of the angles. However, the correlation between the experimental data and those from the individualized model was not greater than that obtained by the generic estimation.

O treinamento de força de baixa intensidade com restrição parcial do fluxo sanguíneo (TFR) emergiu como uma alternativa ao treinamento de força tradicional, com intensidades variando entre moderada a alta, principalmente para idosos que possam apresentar alguma limitação ou dificuldade na realização do treinamento mais intenso. Assim, o presente estudo objetivou analisar a efetividade do TFR na modulação dos níveis de força, área de secção transversa muscular (ASTM) e dos diferentes tipos de fibra (ASTF) bem como da quantidade de células satélites (CS) e mionúcleos (MIO) presentes nas células musculares de indivíduos idosos e comparar os ganhos proporcionados por esse treinamento com os ganhos do treinamento de força tradicional. Trinta sujeitos foram alocados de maneira aleatória e balanceada, pela área de secção transversa muscular do quadríceps, nos seguintes grupos: grupo controle (GC), treinamento de força de baixa intensidade com restrição parcial do fluxo sanguíneo (TFR) e treinamento de força de alta intensidade (TFAI). Após 12 semanas de treinamento, realizados duas vezes na semana, com o exercício Leg Press ambos os grupos, TFR e TFAI apresentaram aumentos nos níveis de força muscular (17% P = 0,067 e 54% P < 0,001 respectivamente) e na ASTM do quadríceps (P < 0,001; 6,6% e 7,9% respectivamente). O grupo controle não apresentou nenhuma alteração significativa dessas variáveis. Após o período de intervenção, a ASTF bem como a quantidade de CS e MIO presentes nas fibras musculares não apresentaram alterações estatisticamente significantes para nenhum dos grupos. Entretanto, no grupo controle foi observada uma queda na ASTF (tipo I = -10%; tipo II = -1%) e também na quantidade de CS e MIO presentes nas fibras (CS = -29,2%; MIO = -9,7%). Para o grupo TFR foi observado um aumento na ASTF tipo II de 13%, contudo um decréscimo de 6% na ASTF do tipo I. Na quantidade de CS o grupo TFR apresentou uma queda de 5% enquanto que para quantidade de MIO foi apresentado um acréscimo de 14,6%. Já o grupo TFAI apresentou uma elevação de 15% na ASTF para ambos os tipos de fibra, I e II. A quantidade de CS aumentou em 32,6% enquanto que a quantidade de MIO presente nas fibras musculares aumentou 3,6%. Os achados do presente estudo mostram adaptações similares nos ganhos de força e hipertrofia muscular entre o TFR e o TFAI, sendo ambos efetivos em reverter os efeitos deletérios do envelhecimento nessas variáveis, consolidando assim o TFR como uma possível alternativa ao TFAI. Quanto à modulação da ASTF bem como da quantidade de CS e MIO por fibra muscular, se comparado ao controle, que apresentou queda nos níveis dessas variáveis, ambos os treinos TFR e TFAI foram capazes de retardar o efeito do envelhecimento sobre essas variáveis, sendo o TFAI mais efetivo em modular a ASTF do tipo I e a quantidade de CS por fibra em dozes semanas de treinamento, realizados duas vezes na semana. Já para modulação da quantidade de MIO por fibra, o TFR apresentou uma ligeira vantagem frente ao TFAI. Dessa forma, em nível celular, no que diz respeito à ASTF, CS e MIO ambos os treinos, após 12 semanas com uma frequência de treinamento baixa, parecem capazes de preservar os níveis dessas variáveis frente ao processo de envelhecimento / The low load resistance training with blood flow restriction (BFR) emerged as an alternative training mode to traditional resistance training (RT), with moderate to high intensities, mainly to elderly, with some limitations or losses, unable to exercise the traditional RT. Thus, the aim of the present study was comparing the effectiveness of BFR to promote strength gains, increases in the muscle and fibers cross sectional area (CSAm and CSAf in that order) as well as an augment in the muscle satellite cells (SC) and myonucleous (MYO) contents in elderly with RT results in these variables. Thirty elderly individuals were ranked in quartiles according to their initial quadriceps CSA and then randomly allocated into one of the following groups: control (CG), low-intensity resistance training with blood flow restriction group (BFR) and high-intensity resistance training (HRT). After 12 weeks of training, twice a week, using the Leg Press exercise, both groups, BFR and HRT presented increases to muscle strength (17% P = 0,067 e 54% P < 0,001 respectively) and CSAm (P < 0,001; 6,6% e 7,9% respectively). The CG did not present any significantly alteration in these variables. After the intervention, the CSAf as well as the SC and MYO contents did not show any significantly alteration for the three groups. However in the CG was observed a CSAf decreases (type I = -16%; type II = -12%) even as in the SC and MYO (CS= -29,2; MYO = -9,7%). To the BFR group was observed an increase of 13% in the type II CSAf while type I presented a decrease of 6%. The CS content decreases 5% whereas MYO content show a increase of 14,6%. To the HRT, both fibers type, I and II, presented an increase in the CSAf (type I = 1%; type II = 12%). To CS and MYO contents HRT showed an augment of 32,6% and 3,6 % respectively. These finds indicate similar strength and hypertrophy gains between BFR and HRT, being both training capable to offset age-related loss in muscle strength and mass, placing the BFR as a surrogate approach to HRT. Comparing the CSAf as well as SC and MYO modulation after intervention in both groups with the control group, BFR and HRT seems capable to break the aging impact on these variables, being the HRT slightly more effective to increase the type I CSA and CS contents while BFR seems slight more effective to increase MYO contents after 12 weeks of training twice a week. On this way both training, BFR and HRT, showed able to preserve CSAf levels even as CS and MYO content during aging

The block periodization training paradigm has been shown to produce enhanced gains in strength and power. The purpose of this study is to assess resistance training induced alterations in lean body mass and cross-sectional area using a block periodization training model among individuals (n = 15) of three differing strength levels (high, moderate and low) based on one repetition maximum back squat relative to body weight. A 3 × 5 mixed-design ANOVA was used to examine within-and between-subject changes in cross-sectional area (CSA), lean body mass (LBM), lean body mass adjusted (LBMadjusted) and total body water (TBW) over an 11-week resistance training program. LBMadjusted is total body water subtracted from lean body mass. The ANOVA revealed no statistically significant between-group differences in any independent variable (p > 0.05). Within-group effects showed statistically significant increases in cross-sectional area (p < 0.001), lean body mass (p < 0.001), lean body mass adjusted (p < 0.001) and total body water (p < 0.001) from baseline to post intervention: CSA: 32.7 cm2 ± 8.6; 36.3 cm2 ± 7.2, LBM: 68.0 kg ± 9.5; 70.6 kg ± 9.4, LBMadjusted: 20.4 kg ± 3.1; 21.0 kg ± 3.3 and TBW: 49.8 kg ± 6.9; 51.7 kg ± 6.9. In conclusion, the results of this study suggest subjects experienced an increase in both lean body mass and total body water, regardless of strength level, over the course of the 11-week block periodized program. Gains in lean body mass and cross-sectional area may be due to edema at the early onset of training.

京都大学 / 新制・課程博士 / 博士(人間健康科学) / 甲第24541号 / 人健博第112号 / 新制||人健||8(附属図書館) / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 黒木 裕士, 教授 青山 朋樹, 教授 松田 秀一 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM

No description available.

Design: A single-blinded, cross-sectional observational study. Objectives: Examine muscle cross-sectional area and symmetry of the lumbar multifidus muscle in elite ballroom dancers with and without low back pain (LBP). Background: The incidence of LBP among elite ballroom dancers is high and at Brigham Young University is 57%. Previous research has linked lumbar multifidus muscle atrophy to low back pain; however this relationship has not been examined in ballroom dancers. Methods and Measures: Lumbar multifidus cross-sectional area was assessed at rest on the right and left side at levels L1-L5. Thirty-seven subjects (age 24 ± 3.2 years; height, 172.8 ± 11.3 cm; mass, 54.6 ± 4.5 kg) were divided into one of three groups. Participants who reported LBP severe enough to interfere with dance training and daily living were allocated to the LBP group (reported pain at rest, during dance, and following dance) (n=15). Subjects who reported LBP that was not strong enough to interfere with training and daily living were allocated to the minimal pain group (reported pain during dance and following dance) (n= 6). And those who reported no back pain were put into the no pain group (n=16). Results: There were no significant difference in demographics between the groups (P>0.05). There was no significant difference between groups in multifidus cross-sectional area (P = .437). Asymmetry was found in all groups with the left side being larger than the right (P < .002). Conclusion: This study provides new information on lumbar multifidus cross-sectional area in elite ballroom dancers. Future research needs to examine other causes of LBP in elite ballroom dancers in an attempt to decrease LBP in these athletes.

Muscle function is determined by structure and morphology at the architectural level. In response to resistance training, older adults have demonstrated that the neuromuscular system has a substantial adaptability, which may compensate for muscle size and quality and lead to improved functional capacities and higher quality of life. PURPOSE: The purpose of this study was to examine the effect of six weeks of progressive resistance exercise on muscle morphology and architecture in healthy older adults. METHODS: Twenty- five healthy men and women were randomly assigned to either six weeks of progressive resistance training (RT) (n=13; age = 71.08 ± 6.75, BMI = 28.5 ± 5.22) or to serve as a control (CON) (n = 12; age = 70.17 ± 5.58, BMI = 27.52 ± 5.6). Fat mass (FM), lean mass (LM), and lean thigh mass (LTM) were evaluated using dual x-ray absorptiometry. Lower body strength was estimated by predicting maximal knee extensor strength (1RM). Muscle quality (MQ) was evaluated as strength per unit mass (kg/kg). Cross-sectional area (CSA), muscle thickness (MT), fascicle length (Lf), pennation angle (cosΘ), and echo intensity (EI) of the rectus femoris (RF) and vastus lateralis (VL) were collected using B-mode ultrasound and extended field of view (FOV) ultrasound. EI was quantified using grayscale analysis software. Strength per unit of echo intensity (REI) was determined by dividing 1RM by EI of the thigh. Physiological cross-sectional area (PCSA) was calculated as the ratio of (CSA x cosΘ) / (EI x Lf). A 2x2 (group [exercise vs. control] x time [pre vs. post]) repeated measures ANOVA was used to identify group differences and group x time interactions and stepwise regression was performed to assess variables related to strength. RESULTS: 1RM increased by 31.9% (p ≤ 0.01) in the RT group and was significantly correlated to PCSA of the thigh (r = .579; p = .003) at baseline. MQ increased 31.4% (p ≤ 0.01) in the RT group consistent iv with an REI increase of 33.3% (p ≤ 0.01). There were no significant changes in LTM in either group. VL CSA increased 7.4%, (p ≤ 0.05) and demonstrated a significant interaction (p ≤ 0.05) in the RT group. There were no significant changes in the CON group for 1RM, MQ, REI or VL CSA. PCSA demonstrated a significant (p ≤ 0.05) group x time interaction but did not significantly change in either group. EI did not significantly change in the RT or CON groups. CONCLUSION: Calculated PCSA of the thigh assessed by ultrasound was related to the force producing capacity of muscle and demonstrated a significant interaction following resistance training. Short term resistance exercise training was effective in increasing 1RM, muscle quality as relative strength, muscle quality as relative echo intensity, and muscle morphology, but not EI. In addition, ultrasonography appears to be a safe, feasible, informative and sensitive clinical technique to aid in our understanding of muscle strength, function, and quality.

Heterobimetallic catalysts offer large potential for efficient and selective catalysis of a wide range of reactions. Better understanding of these catalytic mechanisms could yield further improvement in their catalytic abilities. Cp(CO)2Fe-Cu(IPr) (IPr = N,N-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) is a catalyst that has been reported to catalyze arene borylation. The catalytic mechanism of this catalyst that had been previously proposed had the initial step being a metal-metal cleavage. However, computational modeling suggested an alternate mechanism that could be more energetically favorable. Rather than a metal-metal cleavage as the initial step, we proposed a photoactivated carbonyl dissociation. To support this proposition, we performed time resolved Fourier transform infrared spectroscopy experiments that found evidence supporting our proposed mechanism. Based on these experimental results, we have proposed a new catalytic cycle. The determination of collisional cross section is a powerful tool in analytical chemistry for distinguishing isomers. Techniques such as ion mobility spectrometry can be used to find the collisional cross section of ions but require specialized equipment. Fourier transform ion cyclotron resonance (FTICR) mass spectrometry is a widely used technique for determining ion mass. A technique known as CRoss sectional Area from Fourier Transform Ion cyclotron resonance (CRAFTI) uses a standard FTICR instrument to measure the collisional cross section of ions. This is done by performing a Fourier transform on the data and measuring the Lorenztian width of the peak at the resonant frequency and relating that to the exponential decay of the signal in the time domain. We developed a new data analysis technique that is able to extract just the signal at the resonant frequency in the time domain and directly fit the exponential decay. This new data analysis technique opens new possibilities for expanding the capabilities of CRAFTI measurements, including simultaneous measurement of isomers and a new experimental technique that could measure ions above the mass limit of traditional CRAFTI measurements.

No description available.

Knowledge about biomechanical properties of veins is of importance for understanding the physiologyof the venous system. Specifically for this thesis there is a motivation based on an idea of how to usebiomechanics of the vein in the development of new non-invasive measurement techniques for assessingthe pressure in the brain. The cross sectional area of veins is known to depend on pressure changes insidethe vessel. There are many ways of provoking these pressure changes, like changing posture or creating apositive airway pressure. The hypothesis is that the positive airway pressure will increase the intrathoracic pressure and in turnincrease the pressure in the internal jugular veins by the same magnitude. The cross sectional area will from a pressure change subsequently change with respect to the biomechanical properties of the vessel walls. A first aim in this study was to determine how the cross sectional area of the internal jugular veins is altered due to changes in airway pressure. A second aim was to develop and evaluate a model where the biomechanical properties of the internal jugular veins is described, based on the relationship between pressure and area of the vein. Ultrasound measurements were performed on one healthy adult man to study the effect on the cross sectional area at different pressure provocations. Measurements on the subject was performed at four different head up tilt angles, causing a pressure decrease in the internal jugular vein. A controlled Valsalva method was performed to give the positive airway pressure giving corresponding pressure increases. With an increased airway pressure the effect on cross sectional area changes was about 23% of the effect dueto hydrostatic pressure changes, at a tilt angle from 0° to 8°. At a tilt angle from 8° to 16° the effect was about 35%. Thus the venous pressure seems to be increased due to an increased airway pressure, but not tothe same magnitude. The theoretical model was developed and subsequently evaluated using existing head down tilt magneticresonance imaging data on nine healthy volunteers. An expression for how radius of the vessel depends on pressure changes was derived and evaluated. This expression included individual biomechanical properties that were estimated on group level for the nine subjects. The resulting equation could beused to give an approximate prediction of the increase in radius to a change in venous pressure. In conclusion, the hypothesis suggesting that a positive airway pressure would give an equally increased venous pressure could not be confirmed, and this knowledge should be considered when trying to assess thepressure in the brain with this technique. The derived biomechanical model was promising for predictionof cross sectional area with respect to a change in venous pressure. / Att ha kännedom om biomekaniska egenskaper hos vener är viktigt för att kunna förstå fysiologin hos vensystemet. I den här rapporten finns det i synnerhet ett intresse av detta baserat på en idé för hur veners biomekanik kan användas för att utveckla en ny icke-invasiv mätteknik för att uppskatta trycket i hjärnan. Det är känt att tvärsnittsnittarean av vener beror på tryckförändringar inne i kärlet. Att provocera fram dessatryckförändringar går att göra på många sätt, till exempel genom en förändrad kroppsposition eller genomatt sätta ett positivt tryck på luftvägarna. Hypotesen är att ett positivt luftvägstryck kommer att höja det intratorakala trycket, vilket i sin turkommer att höja trycket inne i de interna jugularvenerna lika mycket. Tvärsnittsarean kommer därmed att ändras enligt biomekaniska egenkaper hos kärlväggen. Ett första syftet i det här arbetet var att bestämma hur tvärsnittsarean av de internal jugularvenerna varierar enligt förändringar i luftvägstryck. Det andra syftet var att utveckla en modell som beskriver de biomekaniska egenskaperna hos de interna jugularvenerna. Detta baserat på relationen mellan tryck och area hos venen. För att studera effekten på tvärsnittsarea för olika tryckprovokationer, genomfördes ultraljudsmätningar på en frisk och vuxen man. Mätningarna på subjektet genomfördes med överkroppen positionerad i fyra olika positiva vinklar relativt horisontalplanet, vilket leder till ett minskat tryck i jugularvenerna. En kontrollerad Valsalvametod användes för att skapa det positiva luftvägstrycket som då ska ge en motsvarande tryckökning. Vid en tiltvinkel på 8° var effekten på areaförändringarna som en följd av ökat luftvägstryck ca 23% av effekten som en följd av de hydrostatiska tryckförändringarna. Vid en tiltvinkel på 16° var effekten ca 35%. Det verkar som att ventrycket ökar med ökat luftvägstryck, men inte med samma storleksordning som det pålagda trycket. Den teoretiska modellen utvecklades och utvärderades sedemera med hjälp av befintligt MRI-data för nio friska och frivilliga subjekt, där överkropparna var positionerade i nedåt tilt. Modellen bestod av ettuttryck för hur radien av ett kärl beror på tryckförändringar inne i det. Modellen innehåller individspecifika egenskaper men utvärderingen gjordes på gruppnivå för de nio subjekten. Det resulterande uttrycket kunde användas för att ge en approximativ förutsägelse om hur radie förändras till följd av en variation i ventryck. Som slutsats så kunde hypotesen som föreslog att ett positivt luftvägstryck skulle ge en lika stor ökning av ventryck inte bekräftas. Om denna teknik ska användas för att försöka bestämma trycket i hjärna så måste hänsyn tas till dessa resultat. Den utvecklade biomekaniska modellen verkar lovande för att kunna förutsäga tvärsnittsarea utifrån ventrycksförändringar.