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Submitted by azevedo@ufp.pt (azevedo@ufp.pt) on 2021-02-25T12:17:11Z No. of bitstreams: 1 PPG_40007.pdf: 8990019 bytes, checksum: bde17a454f3b649c14e91959e304ab9c (MD5) Approved for entry into archive by azevedo@ufp.pt (azevedo@ufp.pt) on 2021-02-25T12:18:31Z (GMT) No. of bitstreams: 1 PPG_40007.pdf: 8990019 bytes, checksum: bde17a454f3b649c14e91959e304ab9c (MD5) Made available in DSpace on 2021-02-25T12:18:31Z (GMT). No. of bitstreams: 1 PPG_40007.pdf: 8990019 bytes, checksum: bde17a454f3b649c14e91959e304ab9c (MD5) Previous issue date: 2020-12-10

BackgroundFlow-controlled ventilation is a novel ventilation method which allows to individualize ventilation according to dynamic lung mechanic limits based on direct tracheal pressure measurement at a stable constant gas flow during inspiration and expiration. The aim of this porcine study was to compare individualized flow-controlled ventilation (FCV) and current guideline-conform pressure-controlled ventilation (PCV) in long-term ventilation.MethodsAnesthetized pigs were ventilated with either FCV or PCV over a period of 10 h with a fixed FiO2of 0.3. FCV settings were individualized by compliance-guided positive end-expiratory pressure (PEEP) and peak pressure (Ppeak) titration. Flow was adjusted to maintain normocapnia and the inspiration to expiration ratio (I:E ratio) was set at 1:1. PCV was performed with a PEEP of 5 cm H2O andPpeakwas set to achieve a tidal volume (VT) of 7 ml/kg. The respiratory rate was adjusted to maintain normocapnia and the I:E ratio was set at 1:1.5. Repeated measurements during observation period were assessed by linear mixed-effects model.ResultsIn FCV (n = 6), respiratory minute volume was significantly reduced (6.0 vs 12.7, MD − 6.8 (− 8.2 to − 5.4) l/min;p n = 6). Oxygenation was improved in the FCV group (paO2119.8 vs 96.6, MD 23.2 (9.0 to 37.5) Torr; 15.97 vs 12.87, MD 3.10 (1.19 to 5.00) kPa;p = 0.010) and CO2removal was more efficient (paCO240.1 vs 44.9, MD − 4.7 (− 7.4 to − 2.0) Torr; 5.35 vs 5.98, MD − 0.63 (− 0.99 to − 0.27) kPa;p = 0.006).Ppeakand driving pressure were comparable in both groups, whereas PEEP was significantly lower in FCV (p = 0.002). Computed tomography revealed a significant reduction in non-aerated lung tissue in individualized FCV (p = 0.026) and no significant difference in overdistended lung tissue, although a significantly higherVTwas applied (8.2 vs 7.6, MD 0.7 (0.2 to 1.2) ml/kg;p = 0.025).ConclusionOur long-term ventilation study demonstrates the applicability of a compliance-guided individualization of FCV settings, which resulted in significantly improved gas exchange and lung tissue aeration without signs of overinflation as compared to best clinical practice PCV.

BACKGROUND In this study, we examined the influence of exercise loading characteristics on bone metabolic responses and bone morphology in the growth phase and adulthood. METHODS Running exercise (RUN) and jumping exercise (JUM) were used for the exercise loading in 28-day-old male Wistar rats. Bone metabolism was measured by blood osteocalcin (OC) and tartrate-resistant acid phosphatase (TRACP) levels. For bone morphology, the maximum bone length, bone weight, and bone strength of the femur and tibia were measured. RESULTS A pre- and post-exercise loading comparison in the growth phase showed significantly increased OC levels in the RUN and JUM groups and significantly decreased TRACP levels in the JUM group. On the other hand, a pre- and post-exercise loading comparison in adulthood showed significantly decreased TRACP levels in the RUN and JUM groups. Femur lengths were significantly shorter in the RUN and JUM groups than in the control (CON) group, while bone weight was significantly greater in the JUM group than in the CON group. CONCLUSIONS Exercise loading activates OC levels in the growth phase and suppresses TRACP levels in adulthood. On the other hand, these results suggest that excessive exercise loading may suppress bone length.

Submitted by Fernanda Campos (fernandinhacampos@yahoo.com.br) on 2016-04-05T01:34:23Z No. of bitstreams: 1 Tese Campos_F .pdf: 1950622 bytes, checksum: 5a96db08575df252b912145aad927d57 (MD5) Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija estas informações e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2016-04-06T17:16:55Z (GMT) Submitted by Fernanda Campos (fernandinhacampos@yahoo.com.br) on 2016-04-06T20:37:19Z No. of bitstreams: 1 TESE Campos f.pdf: 2258577 bytes, checksum: 40b3b75c7d077048eeee83fa2b7b9f03 (MD5) Approved for entry into archive by Ana Paula Grisoto (grisotoana@reitoria.unesp.br) on 2016-04-07T14:05:39Z (GMT) No. of bitstreams: 1 campos_f_dr_sjc_par.pdf: 953589 bytes, checksum: 116ae34d0c22b2f23d76acc3f0ffc32b (MD5) Made available in DSpace on 2016-04-07T14:05:39Z (GMT). No. of bitstreams: 1 campos_f_dr_sjc_par.pdf: 953589 bytes, checksum: 116ae34d0c22b2f23d76acc3f0ffc32b (MD5) Previous issue date: 2016-01-29 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A cimentação de coroas com infraestrutura de zircônia pode ser realizada de diversas formas, com o uso de diferentes cimentos e tratamentos de superfície. No entanto, apesar da existência de alguns estudos sobre o tema, não há um consenso na literatura sobre qual método de cimentação seria mais indicado. O objetivo do presente estudo foi verificar o efeito das diferentes estratégias de cimentação na resistência à fadiga de copings de zircônia. Foram usinados 75 pilares em resina epóxi com formato de um molar simplificado (6 mm de altura, 12 graus de inclinação, ângulos arredondados). Este pilar-padrão foi escaneado e um coping com espessura de 0,7 mm e 80 µm de espaço de cimento foi desenhado virtualmente no software do sistema CAD/CAM utilizado. A partir do desenho virtual, 75 copings de zircônia foram usinados e sinterizados de acordo com as recomendações do fabricante. Esses copings foram alocados em 5 grupos de acordo com o tratamento de superfície ou cimento utilizado: ZP - limpeza com álcool isopropílico + cimento de fosfato de zinco, PN - limpeza com álcool isopropílico + cimento resinoso (Panavia F), GL- aplicação de uma fina camada de glaze + cimento resinoso; AL - Jateamento com partículas de Al2O3 de 125 μm (distância=15 mm/ pressão=3 bar) + cimento resinoso; CJ- Jateamento com partículas de Al2O3/SiO2 de 30 μm (distância=15 mm/ pressão=3 bar) + cimento resinoso. Após tratamento de superfície, os copings foram cimentados aos preparos, sendo aplicada uma carga de 50 N por 5 minutos. O cimento resinoso foi fotoativado por 30 s em cada face. Os espécimes foram testados até momento da fratura em uma máquina de fadiga por 10000 ciclos a cada incremento de carga (600, 800, 1000, 1200, 1400 N) com uma frequência de 1,4 Hz. O modo de falha foi avaliado por microscopia eletrônica de varredura. Foi realizada a análise de “Kaplan-Meier” seguida pelo teste de Mantel-Cox (Log Rank test) e pela comparação múltipla aos pares, todos com nível de significância de 5%. Além disso, também foi utilizada a análise de Weibull. Para a carga de fratura e número de ciclos foi detectada diferença estatística entre as estratégias de cimentação. O modo de falha predominante foi a fratura com início na interface cimento/zirconia. A análise de elementos finitos mostrou uma distribuição diferente da tensão para os dois modelos. A cimentação adesiva levou a uma maior chance de sobrevivência das coroas de zircônia. The cementation of crowns with zirconia infrastructure can be performed in several ways, using different cements and surface treatments. However, despite the existence of some studies on the subject, there is no consensus in the literature on which cementation method would be more appropriate. The aim of this study was to investigate the effect of different cementation strategies in fatigue strength of monolithic zirconia crowns. 75 pillars were machined in epoxy resin with a molar simplified shape (6 mm height, 12 degree tilt, rounded corners). This standard-pillar was scanned and a coping with 0.7 mm of thickness and 80 µm of cement space was virtually designed on the CAD/CAM system software used. From the virtual design, 75 zirconia copings were milled and sintered according to the manufacturer's recommendations. These copings were divided into five groups according to surface treatment or cement used: FZ - cleaning with isopropyl alcohol + zinc phosphate cement, PN - cleaning with isopropyl alcohol + resin cement (Panavia F), GL - application of a thin layer of glaze + resin cement; AL - sandblasting with Al2O3 particles of 125 µm (distance = 15 mm / pressure = 3 bar) + resin cement; CJ - sandblasting with particles of Al2O3/SiO2 of 30 µm (distance = 15 mm / pressure = 3 bar) + resin cement. After surface treatment, the copings were cemented to the pillars with a load of 50 N for 5 minutes. The resin cement was light activated for 30 seconds on each side. The specimens were tested until the moment of fracture in a fatigue machine for 10,000 cycles at each load increment (600, 800, 1000, 1200, 1400 N) at a frequency of 1.4 Hz. The failure mode was assessed by scanning electron microscope. The "Kaplan-Meier" analysis was held followed by the Mantel-Cox test (Log Rank test) and multiple comparison in pairs, all with a significance level of 5%. Furthermore, it has also used the Weibull analysis. For the load to fracture and for the number of cycles to fracture there was detected a difference among the cementation strategies. The predominant mode of failure was a fracture that initiate in the cement/zirconia layer. The FEA showed different stress distribution for the two models. The adhesive cementation approach lead to a significantly higher survival chance for zirconia crowns. FAPESP: 2012/05657-5

Our group has experience with chronotropic incompetence (CI) by using physical stress echocardiography as the diagnostic method; according to already performed cohorts, CI has shown prognostic value. That is the preferred method for individuals with preserved physical capacity. Despite the well-known clinical implications, the underlying mechanism of CI has not been well clarified, autonomic dysfunction being the most frequently found hypothesis in the studies. The use of dobutamine is known to involve an autonomic system participant, the myocardial beta 1 adrenergic receptor, and is more restrictive than physical effort, which involves all the complexity of the system. For practical purpose, most studies define CI as the incapacity to reach 80% of heart rate (HR) reserve according to the formula: HR reserve = (peak HR - resting HR) / (maximum HR - resting HR) x 100. It has been suggested that the definition of CI should be assessed when the diagnostic method uses positive inotropic drugs to induce HR increase. It is necessary to better understand which practical concept of CI applies to the pharmacological stress echocardiography method to study the prognosis of those who have chronotropic incompetence according to that method. The prognostic value of CI probably does not depend on the method used; however, the diagnosis of patients with CI should be well established. Sincerely, Juliana Silva Santana Antonio Carlos Sobral Sousa Joselina Luzia Menezes Oliveira Enaldo Vieira de Melo

Osteocytes establish an extensive intracellular and extracellular communication system via gap junction-coupled cell processes and canaliculi, through which cell processes pass throughout bone, and the communication system is extended to osteoblasts on the bone surface. To examine the osteocyte function, several mouse models were established. To ablate osteocytes, osteocytes death was induced by diphtheria toxin. However, any types of osteocyte death result in necrosis, because dying osteocytes are not phagocytosed by scavengers. After the rupture of cytoplasmic membrane, immunostimulatory molecules are released from lacunae to bone surface through canaliculi, and stimulate macrophages. The stimulated macrophages produce interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha (TNF-α), which are the most important proinflammatory cytokines triggering inflammatory bone loss. Therefore, the osteocyte ablation results in necrosis-induced severe osteoporosis. In conditional knockout mice of gap junction protein alpha-1 (GJA1), which encodes connexin 43 in Gap junction, using dentin matrix protein 1 (DMP1) Cre transgenic mice, osteocyte apoptosis and enhanced bone resorption occur, because extracellular communication is intact. Overexpression of Bcl-2 in osteoblasts using 2.3 kb collagen type I alpha1 (COL1A1) promoter causes osteocyte apoptosis due to the severe reduction in the number of osteocyte processes, resulting in the disruption of both intracellular and extracellular communication systems. This mouse model unraveled osteocyte functions. Osteocytes negatively regulate bone mass by stimulating osteoclastogenesis and inhibiting osteoblast function in physiological condition. Osteocytes are responsible for bone loss in unloaded condition, and osteocytes augment their functions by further stimulating osteoclastogenesis and further inhibiting osteoblast function, at least partly, through the upregulation of receptor activator of nuclear factor-kappa B ligand (RANKL) in osteoblasts and Sost in osteocytes in unloaded condition.

Objectives: Autologous interpositional vein grafts are used in peripheral arterial bypass procedures. Sudden exposure of vein grafts to arterial blood pressure is associated with increased wall tension leading to overdistension of the graft and changes in flow patterns. Overdistension of vein grafts often results in anastomotic leaks, thrombosis, and loss of patency. This study was designed to evaluate the use of a biodegradable collagen cover as a means of preventing overdistension of venous bypass grafts in a rat model. Methods: Twenty-two Sprague-Dawley female rats weighing 250-350 g were randomly assigned to two groups: study group (n= 15) and control group (n=7). In all the rats, a 10-mm segment of the left femoral vein was harvested and used as a graft in repair of a right femoral artery injury. Following this procedure, control rats remained untreated. After completion of the femoral artery repair in the study group, the graft was wrapped with a collagen cover of appropriate length (NeuraWrap Nerve Protector) and sutured to form a tube around the vein graft. At the end of the procedure, the intensity and duration of bleeding, and vessel patency were recorded and the proximal and distal arterial segments were examined by Doppler ultrasonography. All observations and measurements were repeated at 1 and 2 hours after surgery. After the second hour, all the rats were sacrificed and vein graft samples with the arterial portions were removed for histological study. Results: After removal of the vascular clamps of the control group, a sudden distension was observed in all the vein grafts. In this group, bleeding at the anastomosis site lasted for 1 to 3 minutes and was followed by ballooning of the grafts. In the study group, however, none of the samples exhibited distension and ballooning. There was no bleeding in 11 samples at all, and bleeding time was less than one minute in the remaining four samples. In the control group, only one graft was patent at two hours, one of the grafts was occluded after only three minutes. In the study group, all the grafts were patent and no thrombosis was noted. The mean blood flow velocity of the control group measured at 0 hour by Doppler ultrasonography was 0.93±0.33 cm/sec in the proximal artery, and 0.73±0.44 cm/sec in the distal artery. The mean blood flow velocities in the proximal and distal arteries of the study group were as follows, respectively: at 0 hour: 0.45±0.27 and 0.46±0.22 cm/sec; at 1 hour: 0.40±0.22 and 0.62±0.40 cm/sec; and at 2 hours: 0.55±0.22 and 0.64±0.37 cm/sec. Conclusion: Prevention of overdistension of vein grafts with the use of an external cover decreases anastomotic leaks, protects the intimal media, maintains blood flow, reduces the incidence of thrombosis, and thus provides a higher patency rate. © 2010 Turkish Association of Orthopaedics and Traumatology.

Sob a influência da gravidade, o tecido ósseo sofre maior ou menor deformação de acordo com a intensidade das atividades da vida diária. Sabe-se que as atividades que resultam em impacto são as que mais estimulam a osteogênese e assim reduzem a perda de massa óssea. Conhecer como as células ósseas reconhecem a deformação mecânica imposta ao osso e iniciam uma série de reações bioquímicas em cadeia é de fundamental importância para o desenvolvimento de práticas terapêuticas e preventivas na atividade ortopédica. Ainda há um longo caminho para o entendimento de todo esse processo, mas o conhecimento atual progrediu bastante e há pesquisas com finalidade terapêutica. O sinal mecânico para ser transformado em biológico (mecanotransdução) deve ser amplificado no nível celular pela estrutura histológica do tecido ósseo, gerando tensões em proteínas da membrana celular (integrinas) e alterando a estrutura espacial dessas proteínas. Essa alteração ativa ligações entre elas e o citoesqueleto, originando as adesões focais, locais onde proteínas citoplasmáticas são recrutadas para facilitar as reações bioquímicas. A quinase de adesão focal (FAK) é a principal delas, sendo autoativada após sofrer alteração estrutural pelas integrinas. A FAK ativada incita reações em cascata, resultando na ativação da ERK-1/2 e da Akt, proteínas que, junto com a FAK, regulam a produção da massa óssea. Acredita-se que o osteócito seja a célula óssea responsável por reconhecer o estímulo mecânico e transmiti-lo aos osteoblastos e osteoclastos. Canais iônicos e gap junctions são cogitados como meios de comunicação intercelular para a transmissão bioquímica do estímulo mecânico. Esses eventos ocorrem continuamente no tecido ósseo e regulam a remodelação óssea. Influenced by gravidity, bone tissue experiences stronger or lighter deformation according to the strength of the activities of daily life. Activities resulting in impact are particularly known to stimulate osteogenesis, thus reducing bone mass loss. Knowing how bone cells recognize the mechanical deformation imposed to the bone and trigger a series of biochemical chain reactions is of crucial importance for the development of therapeutic and preventive practices in orthopaedic activity. There is still a long way to run until we can understand the whole process, but current knowledge has shown a strong progression, with researches being conducted focused on therapies. For a mechanical sign to be transformed into a biological one (mechanotransduction), it must be amplified at cell level by the histological structure of bone tissue, producing tensions in cell membrane proteins (integrins) and changing their spatial structure. Such change activates bindings between these and the cytoskeleton, producing focal adhesions, where cytoplasmatic proteins are recruited to enable easier biochemical reactions. Focal adhesion kinase (FAK) is the most important one being self-activated when its structure is changed by integrins. Activated FAK triggers a cascade of reactions, resulting in the activation of ERK-1/2 and Akt, which are proteins that, together with FAK, regulate the production of bone mass. Osteocytes are believed to be the mechanosensor cells of the bone and to transmit the mechanical deformation to osteoblasts and osteoclasts. Ionic channels and gap junctions are considered as intercellular communication means for biochemical transmission of a mechanical stimulus. These events occur continuously on bone tissue and regulate bone remodeling.

Objectives To evaluate microtensile bond strength and micro-morphology at the resin–dentin interfaces of two self-etching adhesive systems subjected to simultaneous mechanical and enzymatic stress. Methods Sixteen enamel/dentin discs were bonded with a two-step self-etching adhesive (AdheSE, n = 8) and a one-step self-etching adhesive (Xeno III, n = 8) to a 2 mm thick resin composite layer. One resin–dentin bar was obtained per tooth. In half of the specimens of each group μTBS and micro-morphological evaluations (TEM) was performed without loading. The other half was mechanically loaded in a cholinesterase-containing solution. μTBS as well as ultra-morphological evaluations of the directly loaded areas using TEM were performed on the loaded specimens. Results The μTBS of the specimens (non-loaded/loaded) were of 39.6 ± 14.7/35.4 ± 22.1 and of 21.8 ± 29.8/15.9 ± 25.5 for AdheSE and Xeno III, respectively. Under TEM, both materials presented signs of nanoleakage. However, on loaded specimens the extent of nanoleakage was slightly reduced for AdheSE and no silver staining was observed on the adhesive interface of Xeno III. TEM evaluations of the specimens’ loaded area revealed no decrease in the width of the adhesive interface for AdheSE. The contrary was observed in the interface created by Xeno III. Significance The adhesive interfaces created by the two-step self-etching adhesive (AdheSE) could better withstand both mechanical and enzymatic stresses on the long-term than the one-step self-etching system (Xeno III) tested in the present study.

The purpose of this study was to analyze the hydrodynamic characteristics of a realistic model of an elite swimmer hand/forearm using three-dimensional computational fluid dynamics techniques. A three-dimensional domain was designed to simulate the fluid flow around a swimmer hand and forearm model in different orientations (0°, 45°, and 90° for the three axes Ox, Oy and Oz). The hand/forearm model was obtained through computerized tomography scans. Steady-state analyses were performed using the commercial code Fluent. The drag coefficient presented higher values than the lift coefficient for all model orientations. The drag coefficient of the hand/forearm model increased with the angle of attack, with the maximum value of the force coefficient corresponding to an angle of attack of 90°. The drag coefficient obtained the highest value at an orientation of the hand plane in which the model was directly perpendicular to the direction of the flow. An important contribution of the lift coefficient was observed at an angle of attack of 45°, which could have an important role in the overall propulsive force production of the hand and forearm in swimming phases, when the angle of attack is near 45°.