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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Muscle mitochondria in sepsis /

Fredriksson, Katarina, January 2006 (has links)
Diss. (sammanfattning) Stockholm : Karolinska institutet, 2006. / Härtill 4 uppsatser.
42

Mécanismes cellulaires précoces impliqués dans la dysfonction diaphragmatique induite par la ventilation mécanique / Early cellular mechanisms involved in diaphragmatic dysfunction induced by mechanical ventilation

Dridi, Haikel 01 September 2016 (has links)
La ventilation mécanique(VM) est le premier traitement en réanimation du syndrome de détresse respiratoire aigüe permettant de maintenir une oxygénation tissulaire suffisante. Mais elle induit une atteinte de la fonction contractile des muscles respiratoires, principalement le diaphragme, augmentant ainsi la dépendance du patient vis à vis de son ventilateur. Cette pathologie musculaire acquise est appelée Dysfonction Diaphragmatique induite par la ventilation (VIDD). L’objectif de cette thèse est proposer, à partir d’un modèle murin de ventilation mécanique, les mécanismes physiopathologiques précoces impliqués dans cette dysfonction, afin d’identifier de nouvelles cibles thérapeutiques dans la prévention de cette pathologie musculaire.Nous avons montré en effet la présence, après 6 heures de ventilation mécanique chez la souris, d’un stress oxydant d’origine mitochondrial à la base d’une oxydation du récepteur à la ryanodine (RyR1), principal canal calcique impliqué dans le CEC. Nous avons également montré la présence au bout d’un temps de ventilation mécanique équivalent, d’une phosphorylation de ce même canal, du faite d’une activation de la voie des protéines kinase, secondaire à un stress adrénergique. Nous également avons démontré que ces deux modifications post traductionnelles du RyR1 devaient être nécessairement associées pour induire une atteinte fonctionnelle du canal avec fuite calcique dans le cytosol, du faite de la perte de liaison avec sa protéine stabilisatrice FKBP12. Dans ses travaux de thèse, nous montrons également, que ces anomalies de troubles de l’homéostasie calcique observée après 6 heures de ventilation mécanique, induisaient au bout de 12 heures de ventilation une activation secondaire de la protéolyse dépendante du calcium, associée à une atrophie. Ainsi ces résultats montrent l’intérêt de toutes thérapeutiques permettant de stabiliser la liaison entre le canal RyR1 et sa protéine FKBP12 dans la prévention de la VIDD. En effet, avons observé chez la souris, qu’un traitement anti oxydant spécifique de la mitochondrie (SS-31) ou qu’un traitement bétabloquant spécifique de la voie béta2 adrénergique (ICI-118551) ou qu’un traitement qui stabilise directement la liaison RyR1-FKBP12 (S107) permettaient de prévenir les troubles précoces de l’homéostasie calcique et l’apparition secondaire d’une protéolyse et d’une atrophie induite par la ventilation mécanique. Enfin, dans le dernier travail de ma thèse, je propose que la production de ROS mitochondriale, puisse être associée à un remodelage du réseau mitochondrial avec prépondérance d’un phénomène de fission des mitochondries. Ce remodelage, qui pourrait être considéré comme une adaptation de la mitochondrie du faite d’une rupture brutale de l’équilibre entre production et consommation d’énergie par la fibre musculaire. En effet, nous montrons qu’un inhibiteur de la fission mitochondriale (P110), qui bloque la liaison entre la protéine Drp1 et son récepteur, dans notre modèle animal de ventilation mécanique, pouvait prévenir l’apparition d’une VIDD. Ainsi dans la continuité de ses derniers travaux, afin de faire le lien entre fission mitochondriale et stress oxydant à la base des troubles de l’homéostasie calcique, j’espère montrer que ce traitement, au cours de la ventilation mécanique, limite la production de ROS mitochondriale, l’oxydation du canal RyR1, ainsi que la fuite calcique à travers le RyR1. Ces derniers travaux, mettraient en avant toute thérapeutique permettant de limiter les phénomènes de fission mitochondriale et ses conséquences dans la prévention de la VIDD.Mots clés : RyR, mitochondrie, dysfonction contractile, VIDD, stress oxydant / Mechanical ventilation (MV) is the first treatment in intensive care for acute respiratory distress syndrome to maintain adequate tissue oxygenation. However, it induces an impairment of the contractile function of the respiratory muscles, particularly the diaphragm, thereby increasing the patient's dependence on his ventilator. This acquired muscle disease have been termed ventilator induced diaphragmatic dysfunction (VIDD). The aim of this thesis is to propose, from a mouse model of mechanical ventilation, early pathophysiologic mechanisms involved in this dysfunction, to identify new therapeutic targets in preventing VIDD.We observed after 6 hours of mechanical ventilation, a mitochondrial oxidative stress which induces ryanodine receptor (RyR1) oxidation, the main calcium channel involved in the ECC. We also showed the presence after an equivalent time of mechanical ventilation, phosphorylation of RyR1, due to protein kinase activation, secondary to an adrenergic stress. Then, we have demonstrated that these post-translational modifications of RyR1 should be necessarily associated to trigger a functional impairment of RyR1 with calcium leakage from the sarcoplasmic reticulum to the cytosol, due to the loss of connection between RyR1 and the stabilizing protein KBP12. In his thesis, we also showed that these calcium homeostasis disorders, induced by 12 hours of ventilation, secondary activates the dependent proteolysis calcium and atrophy.Thus, these results show the benefit of all therapy stabilizing the connection between the RyR1 channel and the FKBP12 protein to prevent VIDD. Indeed, were observed in mice, that a specific mitochondrial anti-oxidant treatment (SS-31), or a specific beta-blocker treatment of beta2 adrenergic pathway (ICI-118551 ) or a treatment that stabilizes directly FKBP12- binding RyR1 (S107 ) prevent early disorders of calcium homeostasis and secondary appearance of proteolysis and atrophy induced by mechanical ventilation.Finally, in the last part of my work thesis, I suggest that mitochondrial ROS production may be associated with remodeling of the mitochondrial network with a preponderance of mitochondrial fission phenomenon. This remodeling could be seen as an adaptation of the mitochondria due to a sudden mismatch between energy production and consumption. Indeed, we showed that an inhibitor of the mitochondrial fission (P110), which blocks the connection between the DRP1 protein and its receptor in our animal model of mechanical ventilation, could prevent the appearance of VIDD. Thus the continuity of this last work of my thesis is to make the link between mitochondrial fission and oxidative stress underlying the disorders of calcium homeostasis. Indeed, I hope to show that this treatment during mechanical ventilation, may decrease mitochondrial ROS production, oxidation of RyR1 channel and calcium leak through the RyR1. This last work will emphasis any therapeutic which limit mitochondrial fission and its consequences, to prevent VIDD.Keywords: RyR1, mitochondria, contractile dysfunction, VIDD, oxidative stress
43

Utilização da biomembrana de látex de seringueira (Hevea brasiliensis) em lesões diafragmáticas de coelhos: estudo experimental

Friolani, Milena [UNESP] 24 September 2008 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-09-24Bitstream added on 2014-06-13T19:07:17Z : No. of bitstreams: 1 friolani_m_me_jabo.pdf: 537940 bytes, checksum: e1d3c28c94d98d18c841491512109b44 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Tendo em vista as propriedades de aceleração do processo cicatricial com utilização da biomembrana de látex, este trabalho teve como objetivo avaliar o comportamento de retalho de biomembrana natural de látex, em lesões diafragmáticas induzidas experimentalmente em coelhos. Utilizaram-se 15 coelhos sadios, raça Nova Zelândia, adultos, machos e fêmeas, tendo como acesso ao diafragma, o 8º espaço intercostal direito. Os animais foram divididos, aleatoriamente, em cinco grupos experimentais de três cada, e avaliados diariamente desde o dia da cirurgia até a eutanásia, quanto ao comportamento, freqüência respiratória e cardíaca, cicatrização externa. Os animais foram eutanasiados aos 15, 30, 45, 60 e 90 dias de pós cirúrgico, obtendo-se uma avaliação macroscópica e microscópica do conjunto diafragma/enxerto. Todos os animais apresentaram evolução clínica satisfatória. Macroscopicamente, em todos os grupos experimentais observou-se boa cicatrização na região do implante, com exceção de um dos animais eutanasiados aos quinze dias. Após quinze dias, houve neoformação tecidual, e após trinta dias do ato operatório, em todos animais observou-se aderência do fígado e do pulmão na área de implante. As observações clínico-cirúrgicas complementadas pela análise das alterações histológicas, permitiram concluir pela indicação do emprego da membrana de látex em lesões diafragmáticas reparadoras, em razão da facilidade de obtenção, custo baixo, fácil aplicabilidade, resistência e resposta satisfatória em relação ao tempo de cicatrização. / Having in mind the acceleration properties of the cicatricial process by using the latex bio-membrane, the present paper was aimed at evaluating the behavior of the natural latex bio-membrane flap in diaphragmatic lesions experimentally induced in rabbits. Fifteen healthy New Zealand rabbits, adults, males and females were used, having the eighth right intercostal space as an access to the diaphragm. The animals were randomly assigned to five experimental groups, each with three rabbits. They were evaluated daily from the day of surgery to the day of euthanasia in relation to behavior, respiratory and cardiac frequencies and external cicatrization. The animals were euthanized in 15, 30, 45, 60 and 90 days after the surgery and it was obtained a macroscopic and microscopic evaluation of the set diaphragm/graft. All rabbits presented a satisfactory clinical evolution. Macroscopically, in all experimental groups it was observed a good cicatrization of the implant region, except for one animal that was euthanized in 15 days. After fifteen days, there was tissular neo-formation and thirty days after surgery in all animals it was observed the adherence of the liver and lungs in the implant area. The clinical surgical observations complemented by the analysis of histological alterations allowed the conclusion in favor of the indication of using the latex membrane in reparative diaphragmatic lesions because of the easy obtainment, low cost, easy applicability, resistance, and satisfactory response in relation to the cicatrization time.
44

Efeito do treinamento diafragmÃtico na barreira antirrefluxo e nos sintomas de pacientes com esofagite de refluxo / Effect of training on diaphragmatic thegastroesophageal barrier and symptoms in patients with reflux esophagitis

Maria Josire Vitorino Lima 25 November 2011 (has links)
nÃo hà / INTRODUÃÃO: DoenÃa do Refluxo GastresofÃgico (DRGE) à uma sÃndrome cuja uma das causas à uma alteraÃÃo funcional ou anatÃmica dos mecanismos de contenÃÃo do conteÃdo gÃstrico. à uma desordem crÃnica com estimativa de prevalÃncia alta e variÃvel (10 a 50% da populaÃÃo). IntervenÃÃes na mecÃnica respiratÃria, como o uso de CPAP, podem modificar a ocorrÃncia de RGE, melhorando a pressÃo basal e a taxa de relaxamento espontÃneo do EEI. O principal mÃsculo respiratÃrio à o diafragma, cuja parte crural compÃe a barreira antirrefluxo. O diafragma crural à um mÃsculo esquelÃtico, e como tal, passÃvel de treinamento. Assim, pergunta-se se seria possÃvel melhorar a barreira antirrefluxo atravÃs do treinamento fisioterapÃutico do diafragma. OBJETIVO: Mostrar que o treinamento diafragmÃtico pode ter efeito significativo na barreira antirrefluxo e nos sintomas de pacientes com esofagite de refluxo. MÃTODO: Estudo intervencional onde foram medidas as pressÃes (em mmHg) basal (Pb), e a pressÃo inspiratÃria do esfÃncter esofÃgico inferior (EEI) durante as manobras de arritmia sinusal respiratÃria (Pasr), e com carga inspiratÃria (Threshold IMTÂ) de 17 (Pth17), 35 (Pth35) e 70cmH2O (Pth70). Utilizou-se um sistema de manometria de baixa complacÃncia, perfusional e uma sonda com âdentsleeveâ de 6 cm. O treinamento diafragmÃtico foi realizado durante oito semanas com carga inicial de 30% da pressÃo inspiratÃria mÃxima (PimÃx), com acrÃscimos semanais de 5%. Cada intervenÃÃo de treinamento consistia em 10 sÃries de 15 incursÃes inspiratÃrias, com repouso de 30s a 60s entre as sÃries, e duraÃÃo em mÃdia de 30 min. RESULTADOS: Foram selecionados doze pacientes com DRGE sem hÃrnia hiatal, de ambos os gÃneros (18-50 anos). O estudo demonstrou que a Pb aumentou significativamente apÃs o treinamento diafragmÃtico (19,7  2,4 versus 28,5  2,1; p = 0,0009; n = 12), assim como a Pasr (95,87,8 versus 122,512,7, p=0,0218). A pressÃo inspiratÃria do esfÃncter esofÃgico inferior (EEI) durante a manobra com carga resistiva de 17 cmH20 foi maior apÃs o treinamento diafragmÃtico (117,312,8 versus 138,810,8, p=0,0308). A pressÃo inspiratÃria do EEI durante a manobra com carga resistiva de 35 cmH20 foi semelhante apÃs o treinamento diafragmÃtico (130,713,4 versus 138,810,8, p=0,5085). A pressÃo inspiratÃria do EEI durante a manobra com carga resistiva de 70 cmH20 foi maior apÃs o treinamento diafragmÃtico, apesar de nÃo alcanÃar significÃncia estatÃstica (127,314,0 versus 146,19,5, p=0,0909). O nÃmero de relaxamento transitÃrio do esfÃncter esofÃgico inferior (RTEEI) durante uma hora diminuiu significativamente apÃs o treinamento diafragmÃtico [20,00 (18,0 - 30,3) versus 13,5 (10,7 - 19,5); p = 0,0059)]. Os escores de pirose e regurgitaÃÃo, baseados na frequÃncia de sintomas, foram significativamente menores apÃs o treinamento diafragmÃtico [3,0 (1,0-4,0) versus 0 (0,0-1,0); p = 0,0035;] e [2,5 (0,0-4,0) versus 0 (0,0-4,0); p = 0,0084, respectivamente]. CONCLUSÃO: O treinamento diafragmÃtico inspiratÃrio aumenta a pressÃo basal e inspiratÃria do EEI, diminui a taxa de RETEEI e a sintomatologia na doenÃa do refluxo gastresofÃgico. / INTRODUCTION: The Gastroesophageal Reflux Disease (GERD) is a syndrome wicth one of the causes is a functional or anatomical change in the barrier mechanisms of gastric contents. It is a chronic disorder with a high and changeable estimated prevalence (from 10 to 50% of the population). Interventions in respiratory function, such as the use of CPAP (Continuous Positive Airway Pressure), can alter the occurrence of GERD, improving basal pressure and the rate of spontaneous relaxations of the Lower Esophageal Sphincter (LES). The main respiratory muscle is the diaphragm, whose crural part forms the anti-reflux barrier. The crural diaphragm is a skeletal muscle and hence it can be trained. Therefore, the main question is whether we could improve the anti-reflux barrier through physical therapy training of the diaphragm. OBJECTIVE: To show the training diaphragm may have significant effect on the antireflux barrier and symptoms in patients with reflux esophagitis. METHODS: Intervencional study it was measured the Baseline pressures (Bp) and the inspiratory pressures from the LES, both in mmHg. These measurements were done during the maneuvers of Respiratory Sinus Arrhythmia (RSA) and with inspiratory load (Threshold  IMT) of 17 (Pth17), 35 (Pth35) and 70cmH2O (Pth70).We used a system of low-compliance perfusion manometry, and a sonde with a "dentsleeve" of 6cm. The diaphragmatic training was conducted during eight weeks with initial load of 30% of Maximal Inspiratory Pressure (MIP), with weekly increments of 5%. Each training session consisted of 10 series of 15 inspiratory incursions, with a pause from 30s to 60s between the series, and aberage of 30 minutes duration. RESULTS: Intervencion study with twelve patients carried GERD without hiatal hernia, of both genders (18-50 years old) The study has showed that the Bp increased significantly after the diaphragmatic training (19.7  2.4 versus 28.5  2.1, p = 0.0009, n = 12), as well as the RSA pressure (95,87,8 versus 122,512,7, p=0,0218). The LES pressure, during the maneuver with a resistive load of 17 cmH20, was higher after diaphragmatic training (117,312,8 versus 138,810,8, p=0,0308), white with a resistive load of 35 cmH20 it was similar (130,713,4 versus 138,810,8, p=0,5085). The LES pressure, during the maneuver with a resistive load of 70 cmH20, was higher after diaphragmatic training, although not statistically significant (127,314,0 versus 146,19,5, p=0,0909). The number of transient lower esophageal sphincter relaxations (tLESR), during one hour, decreased significantly after diaphragmatic training [20.00 (18.0 to 30.3) versus 13.5 (10.7 to 19.5), p = 0.0059)]. The scores of heartburn and regurgitation, based on the frequency of symptoms, were significantly lower after diaphragmatic training [3.0 (1.0 to 4.0) versus 0 (from 0.0 to 1.0), p = 0.0035] and [2.5 (0.0 to 4.0) versus 0 (from 0.0 to 4.0), p = 0.0084, respectively]. CONCLUSION: The diaphragmatic training improves the baseline pressure, decreases the tLESR and the symptoms of the GERD.
45

Modelling Lateral Stability of Prefabricated Concrete Structures

Lindwall, Caroline, Wester, Jonas January 2016 (has links)
Stability calculations of prefabricated concrete structures with help of FEM-tools demand knowledge about how the elements are related to each other. This thesis concerns how joints between building elements affect the results when modelling prefabricated concrete structures, with demarcation to joints between hollow core (HC) slabs and between solid wall elements. The thesis also covers how the properties of the floor can be adjusted to account for the effects of the joints without modelling every single element. The work started by measuring the deflection of 10 HC-slabs jointed together and loaded in-plane acting as a deep beam, in a FE-model made with Robot™, from Autodesk®. The joints between the HC-elements were modelled either rigid or elastic, and the cross-section and the length of the HC-elements were varied. The linear elastic stiffness between the HC-elements was obtained from the literature as 0.05 (GN/m)/m. The results showed that a changed cross-section geometry gave greater differences in deformation than a changed length. The in-plane shear modulus was then adjusted for the HC-elements in the rigid cases until the same deflection was achieved as for the elastic cases. The result showed that the shear modulus in average for the different cross-section geometries and lengths had to be reduced with a factor of 0.1 to account for the joints. Based on the geometry of a castellated joint between prefabricated solid concrete walls, a calculation model was developed for its linear elastic stiffness. The result was a stiffness of 1.86 (GN/m)/m. To verify the calculated stiffness, a FE-model was developed consisting of a 30m high wall, loaded horizontally in-plane and with one or two vertical joints where the stiffness was applied. The deflection and the reaction forces were noted and the result from the calculated stiffness was compared to other stiffnesses and assessed reasonable. The reaction forces were shown to depend on the stiffness of the joint. The reduced in-plane shear modulus of the HC-elements and the calculated stiffness of the wall joints were then used in a FE-model of a 10-storey building stabilised by two units. The vertical reaction forces were analysed and the results showed 0.02 % difference in the reaction forces in the stabilising units when consideration of the joints between the HC-elements were taken into account and 0.09 % when the vertical joints in the shear wall were taken into account. The results for the wall joint differed from the results when only the wall was modelled. This was thought to be a result of that the floors counteract the shear deformations in the wall joints. The influence of the floor joints was not significant for the building considered in this thesis, but for buildings with non-continuous configuration of the stiffness in the shear walls the outcome may be another, in these cases the reduction factor may be useful. / Vid stabilitetsberäkningar av prefabricerade betongstommar med hjälp av FEM-verktyg ställs krav på kunskap om hur elementen förhåller sig till varandra. Detta arbete berör hur fogar mellan byggnadselement påverkar modellering av prefabricerade betongstommar med avgränsning till fogar mellan håldäckselement och mellan solida väggelement. Arbetet berör även en studie i hur ett bjälklags egenskaper kan justeras så att fogarnas effekt kan tillvaratas utan att modellera varje enskilt håldäckselement. Arbetet inleddes med att utböjningen analyserades hos 10 st ihopskarvade håldäckselement, lastade i dess plan likt en hög balk, i en FE-modell skapad i programmet Robot™, från Autodesk®. Fogarna mellan håldäcken modellerades som antingen rigida eller elastiska och håldäckens tvärsnittsgeometri och längd varierades under testet. Den linjära styvheten mellan håldäcken togs från litteraturen som 0.05 (GN/m)/m. Resultatet visade att ändrad tvärsnittsgeometri gav större skillnader för deformationen än varierad längd på håldäcken. Håldäckens skjuvmodul justerades sedan i dess plan för de rigida testen tills dess att de uppnådde samma utböjning som de elastiska. Resultatet visade att skjuvmodulen behövdes reduceras med en faktor 0.1, i medeltal för de olika tvärsnittsgeometrierna och håldäckslängderna. Utefter geometrin på en fog med förtagningar mellan prefabricerade väggar togs en beräkningsmodell fram för den linjärelastiska styvheten i väggfogarna. Resultatet blev en styvhet på 1.86 (GN/m)/m. För att verifiera den beräknade styvheten togs en FE-modell fram bestående av en 30m hög vägg lastad horisontellt i dess plan med en eller två vertikala fogar där en linjär styvhet applicerades. Utböjningen samt reaktionskrafterna noterades, resultatet för den uträknade linjära styvheten jämfördes med andra styvheter och bedömdes utifrån detta vara rimlig. Reaktionskrafterna visade sig vara beroende av styvheten på fogen. Den sänkta skjuvmodulen för håldäcken och den beräknade linjära elasticiteten för väggarna användes sedan i en FE-modell av en 10-våningsbyggnad med två stabiliserande enheter där de vertikala reaktionskrafterna analyserades. Resultatet visade att endast 0.02 procentenheter skiljer reaktionskrafterna i de stabiliserande enheterna då hänsyn tas till fogarna mellan håldäcken och 0.09 procentenheter då hänsyn tas till fogarna mellan väggarna. Resultatet skiljer sig från när endast väggen modellerades, vilket tros bero på att bjälklaget hjälper till att motverka deformationer i väggfogarna. Fogen mellan bjälklagselementen tros kunna ha större inverkan på en byggnad med stabiliserande enheter som drastiskt ändrar styvhet från ett plan till ett annat, i dessa fall kan den framtagna reduktionsfaktorn vara av nytta.
46

Methodology for the Design of Timber Frame Structures Utilizing Diaphragm Action

Carradine, David Marc 26 August 2002 (has links)
Modern timber frame buildings are a unique combination of ancient carpentry techniques coupled with one of the newest enclosure systems found on construction sites around the world. Contemporary timber frame structures typically utilize structural-insulated panels (SIPs) attached to a timber frame skeleton to create functional, enclosed structures, such as houses, churches and a myriad of retail and industrial buildings. The skeleton contains large wooden members connected using wooden joints held together with wooden pegs or wedges. SIPs consist of a layer of rigid expanded polystyrene insulation covered on one side by oriented strand board and on the other side by oriented strand board, drywall, or some other interior finish. In timber frame buildings, SIPs also serve as diaphragm elements, which are flat structural assemblies loaded by shear forces in the plane of the panel. Current design methodologies for timber frame structures do not formally incorporate the structural benefits of SIPs as diaphragm elements, which contribute significantly to the ability of these buildings to resist lateral loads. The contribution of this research was to quantify necessary design parameters to enable timber frame designers to capitalize on the significant in-plane strength and stiffness of SIPs when designing timber frame structures to resist lateral loads. Strength and stiffness tests were conducted on three 8 ft (2.44 m) deep and 24 ft (7.32 m) long roof diaphragm assemblies, and two 20 ft (6.10 m) deep and 24 ft (7.32 m) long roof diaphragm assemblies. Data from these tests were collected, tabulated and analyzed according to existing methods typically utilized for post-frame diaphragm testing. Strength and stiffness of timber frame and SIP roof diaphragm assemblies were determined from monotonic test results and a value for Response Modification Coefficient, R, for use with seismic design procedures, was estimated utilizing cyclic test data. Procedures for calculating strength and stiffness of a roof diaphragm based on the strength and stiffness of test panels were presented and incorporated within post-frame diaphragm design methods. Diaphragm-frame interaction analyses were performed utilizing test data from roof diaphragm assemblies that demonstrated the code conformance of members within timber frames subjected to lateral loads. Using roof diaphragm test data and procedures developed for adjustments from the test panel to building roof length, example designs were conducted which confirmed the effectiveness of including SIPs as diaphragm elements for code conforming designs for wind and seismic load resistance of timber frame and SIP buildings. / Ph. D.
47

Design verification of a diaphragm wall with steel piles

Sedey, Jeffrey Scott 05 September 2009 (has links)
A study was conducted to verify the design of a diaphragm wall with steel piles. The original design was based on analysis performed on a soil-structure interaction program using soil parameters calibrated in a previous study. Original and "as-built" design models were compared to measured results of the constructed structure. A second study was conducted to identify the sensitivity of moments and deflections to changes in wall stiffness and soil stiffness. A comparison of the effects of these changes was provided. / Master of Science
48

Effects of Lipin1 Deficiency & Restoration in the Dystrophic Diaphragm

Brown, Alexandra 23 May 2022 (has links)
No description available.
49

PERFLUOROCHEMICAL AUGMENTED INTRATRACHEAL DELIVERY OF ANTIOXIDANT ENZYMES AND GENES TO ATTENUATE OXIDATIVE STRESS-INDUCED LUNG AND RESPIRATORY MUSCLE ALTERATIONS

Malone, Daniel Joseph January 2009 (has links)
Supraphysiologic concentrations of oxygen are used in the management of critically ill patients across the lifespan. However, hyperoxia (HO) results in alveolar- capillary membrane destruction, pulmonary edema, pleural effusions, infiltration and activation of inflammatory cells, altered pulmonary mechanics and gas exchange prompting increased loading of the respiratory muscle. These abnormalities of pulmonary structure and function increase the work of breathing necessitating increased respiratory muscle force production to maintain alveolar ventilation. When the load placed on the respiratory muscle pump exceeds its capacity, respiratory failure develops and is ultimately fatal unless therapeutic interventions are able to reduce the ventilatory load. The use of perfluorochemical (PFC) liquids as a respiratory medium has been effective in the treatment of respiratory distress syndrome and acute lung injury (ALI) requiring mechanical ventilation. Mechanistically, by eliminating the air-liquid interface, PFC liquids reduce surface tension enabling lung volume recruitment at low inspiratory pressures and have high respiratory gas solubility which supports gas exchange. Additionally, through mechanical as well as cytoprotective mechanisms, intrapulmonary PFC liquids reduce inflammatory cell activation and recruitment. Cell culture, animal and human studies have suggested that acute and chronic lung injury secondary to prolonged HO may be ameliorated by administration of antioxidant enzymes (AOE), with superoxide dismutases (SOD) having significant protective effects. Because the lung is exposed to the highest O2 concentrations, a logical strategy to reduce HO-induced damage is to specifically target antioxidant enzymes to the lungs. However, intratracheal delivery of AOE by vehicles like normal saline may transiently impair lung function and be poorly distributed. PFC fluids have previously been shown to be effective respiratory media for pulmonary administration of various drugs. The premise of the proposed studies are to to characterize hyperoxic lung injury in a spontaneously breathing animal model and to develop therapeutic strategies to reduce oxidatative stress and supplement endogenous AOE. With respect to the diaphragm, we reason that HO-induced lung damage and oxidative stress will increase contractile demand of the diaphragm. If AOE activity could be increased in the lungs and respiratory muscles with AOE proteins or the genes encoding these enzymes, then cell damage, inflammatory changes, damage to the lung and respiratory "pump" might be ameliorated or prevented. The results show that PFC and SOD can attenuate the HO- induced decline in lung mechanics and gas exchange, ameliorate the inflammatory and oxidative stress profiles, and promote lung and muscle structural integrity resulting in a survival benefit. These findings support the novel application of PFC liquids in a spontaneously breathing model and support the concept that PFC preconditioning and AOE supplementation play a protective role by reducing mortality and morbidity in hyperoxic lung injury. / Physiology
50

Development of an innovative diaphragm accumulator design and assembly process

Hillesheim, Thorsten January 2016 (has links)
Freudenberg Sealing Technologies has developed a new concept for the manufacture of diaphragm accumulators. Its advantages are a reduced need for components, fewer process steps, shorter assembly times, a higher level of product cleanliness, and an expansion of the product portfolio into additional fields of application. These diaphragm accumulators also weigh significantly less. This is opening up new opportunities for applications in the automotive and industrial fields. The assembly concept is based on a hermetically sealed pressure chamber in which the joining of the two housing halves with the help electromagnetic pulse technology (EMPT) as well as the filling of the gas side with nitrogen takes place in a single operation. In this way, downstream filling to generate the initial gas charge is no longer necessary.

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