This thesis utilized the concept of an optically stimulated Contact Potential Difference (osCPD) sensor to monitor oil properties. The osCPD technique is a variant of the contact potential difference (CPD) method used to obtain surface properties of materials. The technique uses modulated light to stimulate electron charge carriers in silicon coated with a layer of oil. Demonstration of this oil monitoring design was done by placing different oil samples on the silicon surface and monitoring the corresponding electrical signal with the osCPD sensor. Experiments showed that the osCPD sensor produced an electrical signal that was related to the amount of time an oil sample was aged in an engine (or mileage). Further, a linear relationship was found between the relative conductivity of these oils and the osCPD signal. It is theorized that this osCPD signal is dependant on the charge transfer at the silicon and oil interface. Investigation of this interaction was carried out. Experiments showed that adding a silicon nitride passivation layer on the silicon surface eliminated the change in osCPD signal with oil properties. A model of this charge interaction was developed.

This thesis incorporates an array of Contact Potential Difference (CPD) sensors to measure and monitor the degree of skew in the rolling elements of a spherical roller bearing. Skewing is the motion of a roller as it turns about an axis normal to the roller race interface. Roller skew is generated as part of the kinematic effects of roller bearings. Skew monitoring is important for bearing design as it is an indirect measure of bearing life. For the purpose of this thesis, roller skew was measured utilizing multiple pairs of CPD probes located around the bearings outer raceway at varying points of the loading zone. These CPD probes are not in direct contact with the rollers, but in close proximity to their surface (through the bearing outer ring). The skew angle measured is related to different operating conditions such as applied load, shaft speed, and lubrication. The pair of CPD probes detected a signal as the roller surface passed by and the phase difference between the two distinct signals measured the skew angles in the range of 0.016 to 1.10. The shaft is rotated both clockwise and counterclockwise to capture any probe misalignment which was in the range of 0.5 up to 2.0 . This thesis also provides a model for the probe signal as a spherical roller surface passes the probe surface.

Oil analysis is a broad field comprised of hundreds of individual tests that provide meaningful benefit by assessing one or more properties of lubricants or machines. Many tests are performed on new types of oil during research and development. The lubricants chemical, physical, or lubricating properties are validated for quality control purposes and product performance classification. Much of the research in this area is devoted to the online oil degradation systems which allow getting a prompt response about the condition of lubricant. This thesis investigates the concept for monitoring oil degradation with a vibrating Kelvin probe technique. The Vibrating Kelvin probe method for measuring the work function of metals has been used since 1932. Among the applications of this technique are adsorption, corrosion, friction and other studies. A novel application of this method is proposed in this thesis. The vibrating Kelvin system was created with one static surface acting as a sampling surface and the other one electrically isolated. The interaction of the oil with one of the surfaces of a capacitor results in a signal which is synchronously measured. The oil molecules adsorb on the surface of one of the plates and form a space charge layer which changes the work function of that surface. Oil prepared by intentional oxidation was used to evaluate and to monitor the ability to see changes in oil.

Soil salinity is one of the major abiotic stresses that decreases agricultural crop production through imposition of both ionic and osmotic stresses. The accumulation of Na⁺ and Cl⁻ in the cytosol to toxic levels inhibits metabolism. Unlike Na⁺, less is known about Cl⁻ uptake and transport in plants. Grapevine is moderately sensitive to salinity and accumulation of toxic levels of Cl⁻ in leaves is the major reason for salt-induced symptoms. In this study Cl⁻ uptake and transport mechanism(s) were investigated in two grapevine (Vitis sp.) rootstock hybrids differing in salt tolerance: 1103 Paulsen (salt tolerant) and K 51-40 (salt sensitive). Increased external salinity caused high Cl⁻ accumulation in shoots of the salt sensitive K 51-40 in comparison to Paulsen. Measurement of ¹ ⁵ NO₃⁻ net fluxes under high salinity showed that by increasing external Cl⁻ concentrations K 51-40 roots showed reduced NO₃⁻ accumulation. This was associated with increased accumulation of Cl⁻. In comparison to Paulsen, K 51-40 showed reduced NO₃⁻ / Cl⁻ root selectivity with increased salinity, but Paulsen had lower selectivity over the whole salinity range (0-45 mM). In order to examine if root hydraulic and permeability characterisations accounted for differences between varieties, the root pressure probe was used on excised roots. This showed that the osmotic Lpr was significantly smaller than hydrostatic Lpr, but no obvious difference was observed between the rootstocks. The reflection coefficient (σ) values (0.48-0.59) were the same for both rootstocks, and root anatomical studies showed no obvious difference in apoplastic barriers of the main and lateral roots. Comparing the uptake of Cl⁻ with an apoplastic tracer, PTS (3-hydroxy-5, 8, 10-pyrentrisulphonic acid), showed that there was no correlation between Cl⁻ and PTS transport. These results indicated that by-pass flow of salts to the xylem is the same for both rootstocks (10.01±3.03 % and 12.1±1.21 %) and hence pointed to differences in membrane transport to explain difference in Cl⁻ transport to the shoot. ³ ⁶Cl⁻ fluxes across plasma membrane and tonoplast of K 51-40 and Paulsen roots showed that ³ ⁶Cl⁻ influx in root segments of Paulsen was greater than K 51-40 over the first 10 minutes. Unidirectional influx within 10 min loading time showed increases with increases in the external concentrations in both rootstocks but Paulsen had higher influx rate when compared to K 51-40. This appeared to be due to a greater Vmax. There was no significant difference in Km. It was shown that ³ ⁶Cl⁻ accumulation and transport rate to the shoot of K 51-40 was higher than that of Paulsen. Compartmental analysis of ³ ⁶Cl⁻ efflux from intact roots confirmed that the difference in influx observed between the rootstocks was consistent with the results obtained for excised roots, although the values were not exactly the same. It was also shown that the main root of Paulsen had greater contribution to ³ ⁶Cl⁻ uptake than lateral roots. ³ ⁶Cl⁻ fluxes by lateral roots were not significantly different between the rootstocks. Cl⁻ and Na⁺ distribution patterns in different root cell types were determined using the X-ray microanalysis technique. It was shown that Cl⁻ content in the hypodermis and cortical cells was higher than the other cell types in both rootstocks, but overall Cl⁻ content in the root of Paulsen was higher than K 51-40. The pericycle of the main root of Paulsen accumulated more Cl⁻ than K 51-40. It was concluded that Cl⁻ loading to the xylem was different in the rootstocks and Paulsen tended to prevent the xylem Cl⁻ loading process. Lateral roots also displayed opposite behaviour consistent with flux analysis. Membrane potential difference (PD) of the cortical cells showed a rapid and transient depolarization by adding 30 mM NaCl in both rootstocks that was followed by a gradual hyperpolarization. Depolarizations caused by 30 mM Choline-Cl, Na-MES and NaCl measured by the root surface potential method showed that Choline-Cl in K 51-40 and Na-MES in Paulsen caused greater depolarization than that of Na-MES in K 51-40 and Choline-Cl in Paulsen respectively. Assuming that PD measured in this method was the trans-root potential (TRP), it was concluded that the higher depolarization by Choline-Cl in K 51-40 can be due to higher Cl⁻ efflux rate to the xylem. Two different mechanisms were also detected for Cl⁻ transport: HATS which was observed in the range of 0.5-5 mM and a LATS in the range of 10-30 mM of the external NaCl concentration. This was consistent with the concentration dependence of Cl⁻ influx. In conclusion, evidence obtained from different experiments of this study indicated that in the grapevine rootstocks (Paulsen and K 51-40) Cl⁻ was mostly transported through the symplastic pathway. From ECl values determined for the rootstocks by the Nernst equation, a proton-driven transport system was responsible for Cl⁻ transport in both the HATS and LATS range of external NaCl concentrations. The rate of Cl⁻ transport from the root to shoot (xylem loading) was the major difference in Cl⁻ transport between the rootstocks in terms of salinity tolerance. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339051 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

Soil salinity is one of the major abiotic stresses that decreases agricultural crop production through imposition of both ionic and osmotic stresses. The accumulation of Na⁺ and Cl⁻ in the cytosol to toxic levels inhibits metabolism. Unlike Na⁺, less is known about Cl⁻ uptake and transport in plants. Grapevine is moderately sensitive to salinity and accumulation of toxic levels of Cl⁻ in leaves is the major reason for salt-induced symptoms. In this study Cl⁻ uptake and transport mechanism(s) were investigated in two grapevine (Vitis sp.) rootstock hybrids differing in salt tolerance: 1103 Paulsen (salt tolerant) and K 51-40 (salt sensitive). Increased external salinity caused high Cl⁻ accumulation in shoots of the salt sensitive K 51-40 in comparison to Paulsen. Measurement of ¹ ⁵ NO₃⁻ net fluxes under high salinity showed that by increasing external Cl⁻ concentrations K 51-40 roots showed reduced NO₃⁻ accumulation. This was associated with increased accumulation of Cl⁻. In comparison to Paulsen, K 51-40 showed reduced NO₃⁻ / Cl⁻ root selectivity with increased salinity, but Paulsen had lower selectivity over the whole salinity range (0-45 mM). In order to examine if root hydraulic and permeability characterisations accounted for differences between varieties, the root pressure probe was used on excised roots. This showed that the osmotic Lpr was significantly smaller than hydrostatic Lpr, but no obvious difference was observed between the rootstocks. The reflection coefficient (σ) values (0.48-0.59) were the same for both rootstocks, and root anatomical studies showed no obvious difference in apoplastic barriers of the main and lateral roots. Comparing the uptake of Cl⁻ with an apoplastic tracer, PTS (3-hydroxy-5, 8, 10-pyrentrisulphonic acid), showed that there was no correlation between Cl⁻ and PTS transport. These results indicated that by-pass flow of salts to the xylem is the same for both rootstocks (10.01±3.03 % and 12.1±1.21 %) and hence pointed to differences in membrane transport to explain difference in Cl⁻ transport to the shoot. ³ ⁶Cl⁻ fluxes across plasma membrane and tonoplast of K 51-40 and Paulsen roots showed that ³ ⁶Cl⁻ influx in root segments of Paulsen was greater than K 51-40 over the first 10 minutes. Unidirectional influx within 10 min loading time showed increases with increases in the external concentrations in both rootstocks but Paulsen had higher influx rate when compared to K 51-40. This appeared to be due to a greater Vmax. There was no significant difference in Km. It was shown that ³ ⁶Cl⁻ accumulation and transport rate to the shoot of K 51-40 was higher than that of Paulsen. Compartmental analysis of ³ ⁶Cl⁻ efflux from intact roots confirmed that the difference in influx observed between the rootstocks was consistent with the results obtained for excised roots, although the values were not exactly the same. It was also shown that the main root of Paulsen had greater contribution to ³ ⁶Cl⁻ uptake than lateral roots. ³ ⁶Cl⁻ fluxes by lateral roots were not significantly different between the rootstocks. Cl⁻ and Na⁺ distribution patterns in different root cell types were determined using the X-ray microanalysis technique. It was shown that Cl⁻ content in the hypodermis and cortical cells was higher than the other cell types in both rootstocks, but overall Cl⁻ content in the root of Paulsen was higher than K 51-40. The pericycle of the main root of Paulsen accumulated more Cl⁻ than K 51-40. It was concluded that Cl⁻ loading to the xylem was different in the rootstocks and Paulsen tended to prevent the xylem Cl⁻ loading process. Lateral roots also displayed opposite behaviour consistent with flux analysis. Membrane potential difference (PD) of the cortical cells showed a rapid and transient depolarization by adding 30 mM NaCl in both rootstocks that was followed by a gradual hyperpolarization. Depolarizations caused by 30 mM Choline-Cl, Na-MES and NaCl measured by the root surface potential method showed that Choline-Cl in K 51-40 and Na-MES in Paulsen caused greater depolarization than that of Na-MES in K 51-40 and Choline-Cl in Paulsen respectively. Assuming that PD measured in this method was the trans-root potential (TRP), it was concluded that the higher depolarization by Choline-Cl in K 51-40 can be due to higher Cl⁻ efflux rate to the xylem. Two different mechanisms were also detected for Cl⁻ transport: HATS which was observed in the range of 0.5-5 mM and a LATS in the range of 10-30 mM of the external NaCl concentration. This was consistent with the concentration dependence of Cl⁻ influx. In conclusion, evidence obtained from different experiments of this study indicated that in the grapevine rootstocks (Paulsen and K 51-40) Cl⁻ was mostly transported through the symplastic pathway. From ECl values determined for the rootstocks by the Nernst equation, a proton-driven transport system was responsible for Cl⁻ transport in both the HATS and LATS range of external NaCl concentrations. The rate of Cl⁻ transport from the root to shoot (xylem loading) was the major difference in Cl⁻ transport between the rootstocks in terms of salinity tolerance. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339051 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

O teste da diferença de potencial nasal (DPN) é um exame que mede a diferença bioelétrica através do epitélio nasal, a qual resulta do transporte iônico transepitelial dos íons sódio (Na+), pelo canal ENaC (Epitelial Na+ Channel), e cloro (Cl-), pelo canal CFTR(Cystic Fibrosis Transmembrane Conductance Regulator). DPN tem sido utilizada como teste de auxilio diagnóstico em doenças associadas à disfunção do CFTR, como a Fibrose Cística (FC). FC é uma doença genética autossômica recessiva causada por mutações que afetam o funcionamento do canal CFTR (e secundariamente do ENaC) e levam a manifestações em diversos órgãos. Normalmente a dosagem de cloro no suor acima de 60 mEq/L ou a identificação de mutações nos dois alelos confirmam diagnóstico de FC. Porém, existem casos atípicos com exames considerados inconclusivos onde as características eletrofisiológicas decorrentes da disfunção do CFTR devem ser demonstradas para estabelecimento do diagnóstico. A identificação correta destes casos é importante para instituição do tratamento adequado e definição do prognóstico. O objetivo principal deste trabalho foi padronizar a técnica da DPN para sua futura aplicação como ferramenta diagnóstica através da determinação dos seus valores de referência, de sensibilidade, de especificidade e de concordância entre os resultados das duas narinas. Secundariamente, objetivamos analisar as relações entre a presença de função residual do CFTRe a concentração de cloro no suor, fenótipo pancreático, presença de Pseudomonas aeruginosa, função pulmonar e genótipo na amostra de pacientes comFC. Foi realizado um estudo transversal com realização da DPN em um grupo de pacientes com FC (n=29, idade:15±6 anos) e dois grupos controle: não=FC (n=19, idade: 15 ± 10 anos) e sadios (n=19, idade: 17 ± 8 anos). Os resultados demonstraram que os valores da DPN são significativamente diferentes no grupo FC (FC: DPNmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e indiceDPN: 0.85 ± 0.23; não-FC:DPNmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV e indiceDPN: 0.11 ± 0.11) e sadios: DPNmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV e indiceDPN: 0.20±0.14),com sensibilidade e especificidade de 95-96% e concordância de resultado entre as duas narinas maior para a DPNmax (r=0,934). A função residual da CFTR não mostrou relação com nenhum dos parâmetros fenotípicos avaliados. Somente mostrou relação com a gravidade do genótipo. Entretanto, foi observada relação entre os parâmetros que avaliam a hiperfunção do ENaC existente na FC e o fenótipo. Concluímos com este trabalho que foi possível reproduzir e padronizar esta técnica da DPN e demonstrar que o fenótipo da FC está mais relacionado à alteração do transporte do íon sódio através do ENaC do que à presença de função residual da CFTR. / Nasal potential difference test (NPD) is a test that measures the bioelectrical difference across the nasal epithelium, which results from transepithelial ion transport of sodium (Na+), by ENaC channels (Epitelial Na+ Channel) and chloride (Cl-), by CFTR (Cystic Fibrosis Transmembrane Conductance Regulator).NPD has been used as a diagnostic tool in CFTR related disorders, such as Cystic Fibrosis (CF). CF is an autosomal recessive genetic disease caused by mutations that affect the function of the CFTR channel (andsecondarily of the EnaC)and lead to manifestations in various organs. Normally sweat chloride concentration > 60 mEq / L and identification of two CFTR mutations confirm the CF diagnosis. However there are atypical cases with inconclusive sweat chloride or genetic where the electrophysiological characteristics induced by CFTR dysfunction has to be demonstrated for diagnosis. The correct identification of these cases is important for institution of appropriate treatment and definition of prognosis. The objective of this study was to standardize the NPD for its future application as a diagnostic tool through the determination of reference values, sensibility and specificity and agreement of the results between both examined nostrils. Secondarily, we analyzed the relations between residual CFTR function and sweat chloride concentration, pancreatic phenotype, Pseudomonas aeruginosa positivity, pulmonary function and genotype in the sample of CF patients. It was a transversal study where the NPD was measured in a group of CF patients (n = 29, age: 15 ± 6 years) and two control groups: non-CF (n = 19, age: 15 ± 10 years) and healthy (n = 19, age: 17 ± 8 years). The results showed that NPD was significantly different in CF (NPDmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e NPDindex: 0.85 ± 0.23; non-CF: NPDmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV and NPDindex: 0.11 ± 0.11) and healthy: NPDmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV and NPDindex: 0.20±0.14) with sensibility and specificity of 95-96% and agreement between both nostrils greater for NPDmax (r=0.934). The residual CFTR function did not show relation with all phenotypic parameters evaluated. It just showed relation with genotype severity. Indeed it was observed a relation between the parameters that assess the ENaC hyperfunction that occurs in CF and the phenotype. We concluded with this study that was possible to reproduce and to standardize the NPD and to demonstrate that the phenotype is more related to sodium transport alterations through ENaC than to the presence of residual CFTR function.

O teste da diferença de potencial nasal (DPN) é um exame que mede a diferença bioelétrica através do epitélio nasal, a qual resulta do transporte iônico transepitelial dos íons sódio (Na+), pelo canal ENaC (Epitelial Na+ Channel), e cloro (Cl-), pelo canal CFTR(Cystic Fibrosis Transmembrane Conductance Regulator). DPN tem sido utilizada como teste de auxilio diagnóstico em doenças associadas à disfunção do CFTR, como a Fibrose Cística (FC). FC é uma doença genética autossômica recessiva causada por mutações que afetam o funcionamento do canal CFTR (e secundariamente do ENaC) e levam a manifestações em diversos órgãos. Normalmente a dosagem de cloro no suor acima de 60 mEq/L ou a identificação de mutações nos dois alelos confirmam diagnóstico de FC. Porém, existem casos atípicos com exames considerados inconclusivos onde as características eletrofisiológicas decorrentes da disfunção do CFTR devem ser demonstradas para estabelecimento do diagnóstico. A identificação correta destes casos é importante para instituição do tratamento adequado e definição do prognóstico. O objetivo principal deste trabalho foi padronizar a técnica da DPN para sua futura aplicação como ferramenta diagnóstica através da determinação dos seus valores de referência, de sensibilidade, de especificidade e de concordância entre os resultados das duas narinas. Secundariamente, objetivamos analisar as relações entre a presença de função residual do CFTRe a concentração de cloro no suor, fenótipo pancreático, presença de Pseudomonas aeruginosa, função pulmonar e genótipo na amostra de pacientes comFC. Foi realizado um estudo transversal com realização da DPN em um grupo de pacientes com FC (n=29, idade:15±6 anos) e dois grupos controle: não=FC (n=19, idade: 15 ± 10 anos) e sadios (n=19, idade: 17 ± 8 anos). Os resultados demonstraram que os valores da DPN são significativamente diferentes no grupo FC (FC: DPNmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e indiceDPN: 0.85 ± 0.23; não-FC:DPNmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV e indiceDPN: 0.11 ± 0.11) e sadios: DPNmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV e indiceDPN: 0.20±0.14),com sensibilidade e especificidade de 95-96% e concordância de resultado entre as duas narinas maior para a DPNmax (r=0,934). A função residual da CFTR não mostrou relação com nenhum dos parâmetros fenotípicos avaliados. Somente mostrou relação com a gravidade do genótipo. Entretanto, foi observada relação entre os parâmetros que avaliam a hiperfunção do ENaC existente na FC e o fenótipo. Concluímos com este trabalho que foi possível reproduzir e padronizar esta técnica da DPN e demonstrar que o fenótipo da FC está mais relacionado à alteração do transporte do íon sódio através do ENaC do que à presença de função residual da CFTR. / Nasal potential difference test (NPD) is a test that measures the bioelectrical difference across the nasal epithelium, which results from transepithelial ion transport of sodium (Na+), by ENaC channels (Epitelial Na+ Channel) and chloride (Cl-), by CFTR (Cystic Fibrosis Transmembrane Conductance Regulator).NPD has been used as a diagnostic tool in CFTR related disorders, such as Cystic Fibrosis (CF). CF is an autosomal recessive genetic disease caused by mutations that affect the function of the CFTR channel (andsecondarily of the EnaC)and lead to manifestations in various organs. Normally sweat chloride concentration > 60 mEq / L and identification of two CFTR mutations confirm the CF diagnosis. However there are atypical cases with inconclusive sweat chloride or genetic where the electrophysiological characteristics induced by CFTR dysfunction has to be demonstrated for diagnosis. The correct identification of these cases is important for institution of appropriate treatment and definition of prognosis. The objective of this study was to standardize the NPD for its future application as a diagnostic tool through the determination of reference values, sensibility and specificity and agreement of the results between both examined nostrils. Secondarily, we analyzed the relations between residual CFTR function and sweat chloride concentration, pancreatic phenotype, Pseudomonas aeruginosa positivity, pulmonary function and genotype in the sample of CF patients. It was a transversal study where the NPD was measured in a group of CF patients (n = 29, age: 15 ± 6 years) and two control groups: non-CF (n = 19, age: 15 ± 10 years) and healthy (n = 19, age: 17 ± 8 years). The results showed that NPD was significantly different in CF (NPDmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e NPDindex: 0.85 ± 0.23; non-CF: NPDmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV and NPDindex: 0.11 ± 0.11) and healthy: NPDmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV and NPDindex: 0.20±0.14) with sensibility and specificity of 95-96% and agreement between both nostrils greater for NPDmax (r=0.934). The residual CFTR function did not show relation with all phenotypic parameters evaluated. It just showed relation with genotype severity. Indeed it was observed a relation between the parameters that assess the ENaC hyperfunction that occurs in CF and the phenotype. We concluded with this study that was possible to reproduce and to standardize the NPD and to demonstrate that the phenotype is more related to sodium transport alterations through ENaC than to the presence of residual CFTR function.

O teste da diferença de potencial nasal (DPN) é um exame que mede a diferença bioelétrica através do epitélio nasal, a qual resulta do transporte iônico transepitelial dos íons sódio (Na+), pelo canal ENaC (Epitelial Na+ Channel), e cloro (Cl-), pelo canal CFTR(Cystic Fibrosis Transmembrane Conductance Regulator). DPN tem sido utilizada como teste de auxilio diagnóstico em doenças associadas à disfunção do CFTR, como a Fibrose Cística (FC). FC é uma doença genética autossômica recessiva causada por mutações que afetam o funcionamento do canal CFTR (e secundariamente do ENaC) e levam a manifestações em diversos órgãos. Normalmente a dosagem de cloro no suor acima de 60 mEq/L ou a identificação de mutações nos dois alelos confirmam diagnóstico de FC. Porém, existem casos atípicos com exames considerados inconclusivos onde as características eletrofisiológicas decorrentes da disfunção do CFTR devem ser demonstradas para estabelecimento do diagnóstico. A identificação correta destes casos é importante para instituição do tratamento adequado e definição do prognóstico. O objetivo principal deste trabalho foi padronizar a técnica da DPN para sua futura aplicação como ferramenta diagnóstica através da determinação dos seus valores de referência, de sensibilidade, de especificidade e de concordância entre os resultados das duas narinas. Secundariamente, objetivamos analisar as relações entre a presença de função residual do CFTRe a concentração de cloro no suor, fenótipo pancreático, presença de Pseudomonas aeruginosa, função pulmonar e genótipo na amostra de pacientes comFC. Foi realizado um estudo transversal com realização da DPN em um grupo de pacientes com FC (n=29, idade:15±6 anos) e dois grupos controle: não=FC (n=19, idade: 15 ± 10 anos) e sadios (n=19, idade: 17 ± 8 anos). Os resultados demonstraram que os valores da DPN são significativamente diferentes no grupo FC (FC: DPNmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e indiceDPN: 0.85 ± 0.23; não-FC:DPNmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV e indiceDPN: 0.11 ± 0.11) e sadios: DPNmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV e indiceDPN: 0.20±0.14),com sensibilidade e especificidade de 95-96% e concordância de resultado entre as duas narinas maior para a DPNmax (r=0,934). A função residual da CFTR não mostrou relação com nenhum dos parâmetros fenotípicos avaliados. Somente mostrou relação com a gravidade do genótipo. Entretanto, foi observada relação entre os parâmetros que avaliam a hiperfunção do ENaC existente na FC e o fenótipo. Concluímos com este trabalho que foi possível reproduzir e padronizar esta técnica da DPN e demonstrar que o fenótipo da FC está mais relacionado à alteração do transporte do íon sódio através do ENaC do que à presença de função residual da CFTR. / Nasal potential difference test (NPD) is a test that measures the bioelectrical difference across the nasal epithelium, which results from transepithelial ion transport of sodium (Na+), by ENaC channels (Epitelial Na+ Channel) and chloride (Cl-), by CFTR (Cystic Fibrosis Transmembrane Conductance Regulator).NPD has been used as a diagnostic tool in CFTR related disorders, such as Cystic Fibrosis (CF). CF is an autosomal recessive genetic disease caused by mutations that affect the function of the CFTR channel (andsecondarily of the EnaC)and lead to manifestations in various organs. Normally sweat chloride concentration > 60 mEq / L and identification of two CFTR mutations confirm the CF diagnosis. However there are atypical cases with inconclusive sweat chloride or genetic where the electrophysiological characteristics induced by CFTR dysfunction has to be demonstrated for diagnosis. The correct identification of these cases is important for institution of appropriate treatment and definition of prognosis. The objective of this study was to standardize the NPD for its future application as a diagnostic tool through the determination of reference values, sensibility and specificity and agreement of the results between both examined nostrils. Secondarily, we analyzed the relations between residual CFTR function and sweat chloride concentration, pancreatic phenotype, Pseudomonas aeruginosa positivity, pulmonary function and genotype in the sample of CF patients. It was a transversal study where the NPD was measured in a group of CF patients (n = 29, age: 15 ± 6 years) and two control groups: non-CF (n = 19, age: 15 ± 10 years) and healthy (n = 19, age: 17 ± 8 years). The results showed that NPD was significantly different in CF (NPDmax: -34 ± 9mV, Δamil: -20 ± 9mV, ΔCl: 4 ± 5mV, Δamilo-iso: -19 ± 9 mV e NPDindex: 0.85 ± 0.23; non-CF: NPDmax: -14 ± 5mV, Δamil: -6 ± 3mV, ΔCl: 17 ± 9mV, Δamilo-iso: -1 ± 4 mV and NPDindex: 0.11 ± 0.11) and healthy: NPDmax: -15 ± 4mV, Δamil: -6 ± 3mV, ΔCl: 11 ± 7mV, Δamilo-iso: -2 ± 4 mV and NPDindex: 0.20±0.14) with sensibility and specificity of 95-96% and agreement between both nostrils greater for NPDmax (r=0.934). The residual CFTR function did not show relation with all phenotypic parameters evaluated. It just showed relation with genotype severity. Indeed it was observed a relation between the parameters that assess the ENaC hyperfunction that occurs in CF and the phenotype. We concluded with this study that was possible to reproduce and to standardize the NPD and to demonstrate that the phenotype is more related to sodium transport alterations through ENaC than to the presence of residual CFTR function.

This thesis addresses the fabrication, evaluation, and analysis of the probe tip of a non-vibrating contact potential difference sensor. The non-vibrating contact potential difference (nvCPD) probe measures the work function variation on a conducting surface and recent experiments performed to measure the size of surface features have shown poor correlation between actual and calculated probe tip dimensions. In order to address this deficiency, experiments were done and an analytical model was developed, including fringe electrical fields, that predicts the shape of the nvCPD probe signal as a function of probe tip geometry, work function variation, and experimental parameters. Probe tips were constructed with varying geometric properties and experiments using these probe tips were compared to a model. There was good correlation of the nvCPD probe output for a known work function change and probe tip geometry. The effective area of the probe tip resulting from electrical field fringing is expected to increase with dielectric thickness to a finite value, based on pre-existing electrostatic models for a shielded parallel plate capacitor. The minimum fringe field obtained in these experiments was for a 3.18mm diameter probe tip with a dielectric thickness of 0.20mm. The fringe field diameter was 3.38mm at a fly height of 0.60mm, representing an effective probe tip area increase of 13%.

Exercise has become a vital component of the therapy regimen prescribed to cystic fibrosis (CF) patients due to its systemic benefits, such as increased sputum expectoration, attenuation of the expected 2-3% annual decline in pulmonary function, and extended life expectancy. However, exercise still is not viewed as being as beneficial as pharmacological treatments by many CF patients and can be intimidating. My aims in this study were two-fold; first, to determine the ideal exercise intensity for individuals with CF; and second, to determine if exercise at this ideal intensity could provide improvements in ion regulation in the lungs, which was measured using exhaled breath condensate (EBC) collection and nasal potential difference (NPD), that were comparable to one of their standard pharmacological therapies, albuterol. I hypothesized that with moderate intensity exercise, Na⁺ absorption would decrease from baseline due to Na⁺ channel inhibition, rather than increase or remain unchanged, as was expected with albuterol, and cause an even greater increase Cl- secretion compared to albuterol due to activation of both CF-dependent and independent Cl- efflux with exercise. CF (n=14) and healthy (n=16) subjects completed three visits, a baseline screening and two treatment visits. I collected EBC at baseline, 30- and 60-minutes post-albuterol administration on one visit, and at baseline and during three separate 15 min exercise bouts at low, moderate and high intensity on the other visit. Following the EBC collection, NPD was performed at 30- and 80-minutes post albuterol or following moderate and high intensity exercise. We also measured spirometry and diffusing capacity of the lungs for nitric oxide (DLNO) during each visit at the various time points. In CF subjects, moderate intensity exercise resulted in greater improvements in DLNO (39 ± 29vs.15 ± 22% change from baseline, exercise vs. albuterol respectively), similar levels of bronchodilation compared to 60-minutes post-albuterol administration, no change in Na⁺ absorption, and a four-fold increase in Cl- secretion. Our results suggest that moderate intensity exercise is the best dose for CF patients, and can provide comparable changes as its pharmacological counterpart albuterol, when compared over a short term duration.