10 resultados para ultra-sonografia modo-A

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Analisar, em pacientes submetidos a simpaticotomia videotoracoscópica para tratamento da Hiperidrose Primária (HP), as conseqüências hemodinâmicas da desnervação vascular das artérias carótidas e vertebrais após a trans-secção cirúrgica da cadeia simpática torácica (simpaticotomia), através da mensuração de parâmetros ultra-sonográficos. Método: Vinte e quatro pacientes portadores de HP submetidos a quarenta e oito simpaticotomias torácicas endoscópicas foram avaliados através da mensuração da velocidade de pico sistólico (VPS), velocidade de pico diastólico (VPD), índice de pulsatibilidade (IP) e índice de resistência (IR) nas artérias carótidas comuns, internas e externas, além da artéria vertebral bilateralmente usando o eco-doppler duplex scan. As avaliações foram realizadas antes da intervenção cirúrgica e trinta dias após o procedimento. O teste de Wilcoxon foi usado na análise das diferenças entre as variáveis antes e depois da simpaticotomia. Resultados: A simpaticotomia no nível de T3 foi a trans-secção mais realizada (95,83%), seja isoladamente (25%) ou associada a T4 (62,50%) ou a T2 (8,33%). Houve aumento significativo no IR e no IP da artéria carótida comum bilateralmente (p<0,05). A VPD da artéria carótida interna diminuiu em ambos os lados (p<0,05). A VPS e a VPD da artéria vertebral direita também aumentaram (p<0,05). Achados assimétricos foram observados, de modo que artérias do lado direito foram as mais freqüentemente afetadas. Conclusões: Alterações hemodinâmicas foram observadas nas artérias vertebral e carótida após simpaticotomia para tratamento de HP. VPS foi o parâmetro mais freqüentemente alterado, principalmente nas artérias do lado direito, representando alterações assimétricas significantes nas artérias carótida e vertebral. Entretanto, são necessárias pesquisas subseqüentes para verificar se essas alterações são definitivas ou temporárias, uma vez que as inferências clínicas somente terão validação se as alterações forem permanentes

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The so-called Dual Mode Adaptive Robust Control (DMARC) is proposed. The DMARC is a control strategy which interpolates the Model Reference Adaptive Control (MRAC) and the Variable Structure Model Reference Adaptive Control (VS-MRAC). The main idea is to incorporate the transient performance advantages of the VS-MRAC controller with the smoothness control signal in steady-state of the MRAC controller. Two basic algorithms are developed for the DMARC controller. In the first algorithm the controller's adjustment is made, in real time, through the variation of a parameter in the adaptation law. In the second algorithm the control law is generated, using fuzzy logic with Takagi-Sugeno s model, to obtain a combination of the MRAC and VS-MRAC control laws. In both cases, the combined control structure is shown to be robust to the parametric uncertainties and external disturbances, with a fast transient performance, practically without oscillations, and a smoothness steady-state control signal

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work describes the study, the analysis, the project methodology and the constructive details of a high frequency DC/AC resonant series converter using sequential commutation techniques for the excitation of an inductive coupled thermal plasma torch. The aim of this thesis is to show the new modulation technique potentialities and to present a technological option for the high-frequency electronic power converters development. The resonant converter operates at 50 kW output power under a 400 kHz frequency and it is constituted by inverter cells using ultra-fast IGBT devices. In order to minimize the turn-off losses, the inverter cells operates in a ZVS mode referred by a modified PLL loop that maintains this condition stable, despite the load variations. The sequential pulse gating command strategy used it allows to operate the IGBT devices on its maximum power limits using the derating and destressing current scheme, as well as it propitiates a frequency multiplication of the inverters set. The output converter is connected to a series resonant circuit constituted by the applicator ICTP torch, a compensation capacitor and an impedance matching RF transformer. At the final, are presented the experimental results and the many tests achieved in laboratory as form to validate the proposed new technique

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work presents a theoretical and experimental investigation about the properties of microstrip antennas for ultra-wideband systems. Configurations of elliptic monopoles with different eccentricities and circular monopoles are considered. Two prototypes for each antenna configuration were built, one with the typical microstrip configuration and the other is similar to the first, except for a small aperture in the ground plane. Therefore, this work proposes to modify the configuration of the ground plane of the monopoles designed adding a rectangular stub, in order to optimize and improve the performance of such structures. The obtained results show that the introduction of that rectangular aperture in the ground plane allows an improvement of the frequency response for the considered antenna propotypes. It is observed a good agreement between the measured and simulated results. Finally, some proposals for future works are presented

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work is proposed an indirect approach to the DualMode Adaptive Robust Controller (DMARC), combining the typicals transient and robustness properties of Variable Structure Systems, more specifically of Variable Structure Model Reference Adaptive Controller (VS-MRAC), with a smooth control signal in steady-state, typical of conventional Adaptive Controllers, as Model Reference Adaptive Controller (MRAC). The goal is to provide a more intuitive controller design, based on physical plant parameters, as resistances, inertia moments, capacitances, etc. Furthermore, with the objective to follow the evolutionary line of direct controllers, it will be proposed an indirect version for the Binary Model Reference Adaptive Controller (B-MRAC), that was the first controller attemptting to act as MRAC as well as VS-MRAC, depending on a pre-defined fixed parameter

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundação de Amparo a Pesquisa do Estado de São Paulo

Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION: The high sensitivity C-reactive protein (hsCRP) constitutes an inflammatory mediator used as predictor of cardiovascular risk that comes being researched as indicative relation factor between cardiovascular and periodontal diseases. PROPOSITION: To compare serumals levels of C-reactive protein between patients with and without generalized severe chronic periodontitis. METHODOLOGY: A seccional study was realized using a sample with 62 patients, being 31 participants carriers of periodontal diseases (Group I) and 31 without periodontal diseases (Group II), grouped to the pairs by age and sex. As inclusion criterio were selected patients with diagnosis of generalized severe chronic periodontitis, being preculeds, individuals which presented systemic disease, recent infection history, historical of CVA or stroke, smokers, pregnants and lactants. The research consisted of two stages, a clinc and other biochemist. The clinical stage is constituted of periodontal examination and the biochemist stage, of the peripheral blood collection for determination hsCRP levels and a hemogram to inquire any panel which could suggest infectious and/or inflammatory process. RESULTS: Periodontal disease group presented a average of 0,36mg/dL, while the group without disease presented 0,17 mg/dL, do not existing significant difference statistically between the averages (p = 0,061). The cardiovascular risk for the group I was classified high for 27,6% of participants and low for 72,4% of them. In the group II, 6,45% presented high risk e 93,5% low risk, being this significant relation statistically gotten for Fisher s Test (p = 0,042) presenting OR = 5,33; IC = 95% (1,02 27,4). The independets variables reseacred do not presented significant association statistically with the levels of hsCRP. CONCLUSION: The study indicated that despite of carriers patients of periodontal diseases do not present differents serumals levels of hsCRP from the other group, the periodontal disease was considered as risk factor for hsCRP plasmatic levels elevation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PAHs (Polycyclic Aromatic Hydrocarbons) are a group of organic substances which receive considerable attention because of the carcinogenic and mutagenic properties of some of them. It is therefore important to determine the PAHs in different environmental matrices. Several studies have shown the use of gas chromatography coupled to mass spectrometry as a technique for quantification of PAHs by presenting excellent detection limits. This study aimed to develop an analytical methodology for the determination of 16 PAHs listed by the USEPA, test two methods for extraction of PAHs in water from a 23 factorial design, quantify them through the analytical technique coupled to gas chromatography mass spectrometry (GC/MS) using the method developed, and finally apply the results in chemometrics. The sample was synthesized and subjected to tests of the 23 factorial design, which has the factors: the type of extraction technique (ultrasound and digester), the ratio solvent / sample (1:1 and 1:3) and the type of solvent (dichloromethane / hexane and acetone / dichloromethane). The responses of eight combinations of the factorial design were obtained from the quantification by external calibration in GC/MS. The quantification method was developed from an optimized adaptation of the USEPA Method 8270. We used the full scan mode as a way of acquiring the mass spectra of 16 PAHs. The time in which the samples were subjected to ultrasound was fixed at 10 min and held an investigation to establish the conditions of power and time in the digester. We had the best response in the investigation of the digester power of 100 watts and the time of six minutes. The factorial design of liquid-liquid extraction showed that the most representative factors were: the use of the digester as extraction technique, the ratio solvent / sample 1:1 and the use of a 1:1 mixture of dichloromethane / hexane as a solvent more suitable. These results showed that the 1:1 mixture of dichloromethane / hexane is an excellent mixture to recover the extraction of PAHs an aqueous sample using the microwave digester. The optimization of the method of separation, identification and quantification of PAHs in the GC/MS was valid for 16 PAHs present in each chromatogram of the samples

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Dental pulp stem cells have been widely investigated because of their ability to differentiate into both dental and non-dental cells, with potential use in therapies involving tissue engineering. The technique of cell cryopreservation represents a viable alternative for the conservation of these cells, since it stops reversibly, in a controlled manner, all of cell biological functions in an ultra low temperature. The present study aimed to evaluate, using in vitro experiments, the influence of a cryopreservation protocol on the biologic acti vity of stem cells from human exfoliated deciduous teeth (SHED). Cells obtained from the pulp of three deciduous teeth on end-stage exfoliation or with indicated extraction were expanded in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. At second subculture (P2), a group of cells were submitted to cryopreservation for 30 days in 10% DMSO diluted in fetal bovine serum, at -80º C, while the remind cells continued under normal conditions of cell culture. Cell proliferation was evaluated in both groups (not cryopreserved or cryopreserved) by Trypan blue stain essay at intervals of 24, 48 and 72h after plating. Cell cycle analysis of SHEDs submitted or not to the cryopreservation protocol was performed in the same intervals. Events related to cell death were studied by Annexyn V and PI expression under flow cytometry at the intervals of 24 and 72h. The presence of nuclear morphological changes was evaluated by DAPI staining at 72h interval. It was observed that both groups exhibited an upward cell proliferation curve, without considerable changes in cell viability throughout the experiment. The distribution of cell in the cell cycle phasis was consistent with cell proliferation in both groups. There were no nuclear morphological damages in the end range of the experiment. therefore, it is concluded that the proposed cryopreservation protocol is efficient for storing the studied cell type, allowing its use in future experimental studies

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Societal concerns about environmental sustainability has lead to the development of ecologically-friendly alternatives to chemical insecticides for crop protection. One such alternative is biological pest control. In particular, baculoviruses are well suited as insect biopesticides due to their narrow host specificity and relative ease of propagation. In Brazil, the baculovirus Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV) is the main biological control agent employed for the soybean pest, Anticarsia gemmatalis. This baculovirus biopesticide is currently produced using caterpillars, but increasing market demand for the product has encouraged the development of an in vitro manufacturing process, which can be scaled up to much higher virus productivities. In this study, three wild-type AgMNPV isolates (AgMNPV-2D, AgMNPV-MP2 and AgMNPV-MP5) and a recombinant form (vAgEGT-LacZ) were characterised in terms of occlusion body (OB) production and infection kinetics, to enable future optimisation of the in vitro production process. These viruses were propagated using a Spodoptera frugiperda (IPLB-SF21) insect cell line grown in shaker-flask batch cultures. Among the virus isolates tested, AgMNPV-MP5 was found to be the best producer, yielding (5.3±0.85)x108 OB/mL after 8 days post infection. The characterisation of vAgEGT-LacZ propagation in suspension cell cultures has not been previously reported in the literature; hence it became the main focus for this thesis. In particular, it was carried out a study on the effect of the multiplicity of infection (MOI) on OB production. Five successive batches were performed getting a final production (8.9±1.42)x1014 occlusion bodies, considering that production is related for a bioreactor with final volume of 10m3. A low MOI associated with a fed-batch process for vAgEGT-LacZ production was found to support a 3-fold higher OB yield when compared to the default batch process (1.8x107 and 5.3x107 OB/mL, respectively). This yield is competitive with regards to the production process.