• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 19
  • 11
  • 3
  • 3
  • 3
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 44
  • 44
  • 13
  • 11
  • 9
  • 9
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 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

Novo método de hipotermia encefálica exclusiva através de resfriamento nasofaríngeo: modelo experimental em suínos / New method of exclusive brain hypothermia by means of nasopharyngeal cooling: swine experimental study

Paiva, Bernardo Lembo Conde de 20 October 2014 (has links)
INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas, contudo reduz significativamente a PbtO2 / INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly
42

An Electromagnetic Actuated Microvalve Fabricated on a Single Wafer

Sutanto Bintoro, Jemmy 23 November 2004 (has links)
Microvalves are essential components of the miniaturization of the fluidic systems to control of fluid flow in a variety of applications as diverse as chemical analysis systems, micro-fuel cells, and integrated fluidic channel arrangements for electronic cooling. Using microvalves, these systems offer important advantages: they can operate using small sample volumes and provide rapid response time. This PhD dissertation presents the world first electromagnetically actuated microvalve fabricated on a single wafer with CMOS compatibility. In this dissertation, the design, fabrication, and testing results of two different types of electromagnetic microvalves are presented: the on/off microvalve and the bistable microvalve with latching mechanism. The microvalves operate with power consumption of less than 1.5 W and can control the volume flow rate of DI water, or a 50% diluted methanol solution in the range 1 - 50 µL in. The leaking rate of the on/off microvalve is the order of 30 nL/min. The microvalve demonstrated a response time for latching of 10 ms in water and 0.2 ms in air. This work has resulted in a US patent, application no. 10/699,210.Other inventions that have been developed as a result of this research are bidirectional, and bistable-bidirectional microactuators with latching mechanism, that can be utilized for optical switch, RF relay, micro mirror, nano indenter, or nano printings.
43

Novo método de hipotermia encefálica exclusiva através de resfriamento nasofaríngeo: modelo experimental em suínos / New method of exclusive brain hypothermia by means of nasopharyngeal cooling: swine experimental study

Bernardo Lembo Conde de Paiva 20 October 2014 (has links)
INTRODUÇÃO: Evidências relevantes acerca dos benefícios da hipotermia terapêutica provieram da utilização de técnicas de resfriamento sistêmico. Essas técnicas, no entanto, podem causar complicações graves que poderiam ser evitadas com métodos de hipotermia encefálica seletiva. O presente estudo objetiva: 1) verificar a viabilidade da hipotermia encefálica exclusiva através de um sistema de resfriamento nasofaríngeo concomitante ao de preservação da temperatura corpórea em suínos e 2) investigar os efeitos da hipotermia encefálica exclusiva nas variáveis fisiológicas sistêmicas e encefálicas. MÉTODOS: Dez suínos híbridos foram submetidos a resfriamento nasofaríngeo durante 60 minutos e subsequente reaquecimento espontâneo. Foram obtidos dados referentes a: pressão arterial média, débito cardíaco, temperatura encefálica, pressão parcial de oxigênio do tecido encefálico (PbtO2, do inglês, pressure of brain tissue O2), velocidade do fluxo sanguíneo nas artérias encefálicas, índice de resistência e índice de pulsatilidade. RESULTADOS: O resfriamento nasofaríngeo associou-se à um decréscimo gradual da temperatura encefálica, que foi mais marcante no hemisfério cerebral esquerdo (p < 0,01). Neste hemisfério, houve redução de 1,47 ± 0,86°C nos primeiros 5 minutos (p < 0,01), 2,45 ± 1,03°C aos 10 minutos e 4,45 ± 1,36°C após 1 hora (p < 0,01). A diferença entre as temperaturas cerebral sistêmica foi 4,57 ± 0,87°C (p < 0,01). As temperaturas centrais (retal, esofágica e da artéria pulmonar), assim como a hemodinâmica encefálica e sistêmica, mantiveram-se estáveis durante o procedimento. Houve diminuição significativa da PbtO2, concomitantemente ao decréscimo da temperatura encefálica. CONCLUSÕES: A indução de hipotermia encefálica exclusiva é possível através de resfriamento nasofaríngeo associado a medidas de preservação da temperatura sistêmica. O resfriamento encefálico exclusivo não influencia as funções hemodinâmicas sistêmicas e encefálicas, contudo reduz significativamente a PbtO2 / INTRODUCTION: Relevant evidences for the use of therapeutic hypothermia derive from studies using whole body cooling methods. These methods can lead to serious complications. To avoid such complications, selective brain cooling methods were developed. The objective of this study was: 1) to verify the feasibility of exclusive brain hypothermia by means of nasopharyngeal cooling along with measures of systemic temperature preservation in an experimental swine model, and 2) to investigate the influence of the exclusive brain cooling on cerebral and systemic hemodynamics as well as on cerebral oxygenation. METHODS: Ten hybrid swine underwent nasopharyngeal cooling for 60 minutes, followed by spontaneous rewarming. A number of physiological variables were monitored: arterial blood pressure, cardiac output, temperature in the right and left cerebral hemispheres, pressure of brain tissue O2, cerebral blood flow velocities, resistance index, and pulsatility index. RESULTS: Nasopharyngeal cooling was associated with decrease in brain temperature, which was more significant in the left cerebral hemisphere (p < 0,01). There was a reduction of 1.47 ± 0.86°C in the first 5 minutes (p < 0.01), 2.45 ± 1.03°C within 10 min, and 4.45 ± 1.36°C after 1 hour (p < 0.01). The brain-core gradient was 4.57 ± 0.87°C (p < 0,001). Rectal, esophageal, and pulmonary artery temperatures, as well as brain and systemic hemodynamics, remained stable during the procedure. PbtO2 values significantly decreased following the brain cooling. CONCLUSION: Achievement of exclusive brain hypothermia is feasible by means of nasopharyngeal cooling associated with measures of systemic temperature preservation. Selective brain cooling does not influence both systemic and cerebral hemodynamics, except PbtO2, which decreased significantly
44

Stavebně technologický projekt polyfunkčního domu Art Passage v Trenčíně / Construction technological project of polyfunctional building Art Passage in Trenčín

Rozvadská, Marcela January 2014 (has links)
This thesis deals with the structural and technological project of multifunctional building Art Passage in Trencin. Solve division building construction and civil engineering objects, draw up the draft machine assembly time and financial plan. They will further focus on the rough construction of the main building structure, where processing technology studies during construction schedule, the project site equipment, budget and other documents that are necessary for the proper implementation of construction.

Page generated in 0.078 seconds