Techn. Universiẗat, Diss., 2000--Darmstadt. / Dateiformat: tar.gz, Dateien im PDF-Format.

Thesis (Ph.D.)--Boston University / The heat capacity (Cp) of four Beta-quinol clathrates of carbon monoxide with y = 0.460, 0.626, 0.752 and 0.810, and of one HBr clathrate with y = 0.811 have been measured from 15 to 300K. Cp for 3C6H4(OH)2 * yCO is found to be a linear function of y. The partial molal heat capacity and entropy of clathrated CO and hte heat capacity and entropy of 3 moles of Beta-quinol have been calculated. The respective values at 298.15K are: Cco = 9.76 +/- 0.8 cal. deg.^-1mol^-1; SCO = 20.94 +/- 0.20 cal. deg.^-1mole^-1; Cp^Q = 98.72 cal. deg.^-1; S^Q = 100.28 cal. deg.^-1. [TRUNCATED]

Anticholinergic therapy has long been a cornerstone of management of chronic obstructive pulmonary disease (COPD) but has not been included in treatment guidelines for asthma. In September 2015, tiotropium bromide was approved for use in adults with asthma; the indication has since been expanded to children ages 6 years and older. This article discusses appropriate patient selection and dosing, and the role of tiotropium bromide in asthma management.

Addition reactions of pentafluorosulfur bromide (SF5Br) with fluoroolefins were studied. Three new adducts were prepared, SF5CHFCHC1Br, SF5CH2CH(CF3)Br, SF5CHFCFC1Br. SF5Br and CFC1=CHC1 yielded a small amount of product but attempts to add SF5Br to CF2=FCOF were unsuccessful. The mechanism for these addition reactions seems to involve a free radical addition pathway. Steric factors seem to be important in determining whether SF5Br will add to fluoroolefins. The new compounds, SF5CF(CF3)COF and SF5CF(CF3 )CONH2 have been produced from SF5CF=CF2. Analytical data, infrared, Raman, nmr and mass spectra are presented supporting the proposed structures for these new compounds.

The Vanadium bromide (V/Br) flow cell employs the Br3-/Br- couple in the positive and the V(II)/V(III) couple in the negative half cell. One major issue of this flow cell is bromine gas formation in the positive half cell during charging which results from the low solubility of bromine in aqueous solutions. Bromine complexing agents previously used in the zinc-bromine fuel cell were evaluated for their applicability in V/Br flow cell electrolytes. Three quaternary ammonium bromides: N-ethyl-N-methyl-morpholinium bromide (MEM), N-ethyl-N-methyl-pyrrolidinium bromide (MEP) and Tetra-butyl ammonium bromide (TBA) were studied. It is known that aqueous bromine reacts with quaternary ammonium bromides to form an immiscible organic phase. Depending on the number of quaternary ammonium bromides used and the environmental temperature, the second phase formed will either be solid or liquid. As any solid formation would interrupt the flow cell operation, potential formation of such kind has to be eliminated. Stability tests of simulated V/Br electrolyte with added quaternary ammonium bromides were carried out at 11, 25 and 40 oC. In the absence of bromine, the addition of MEM, MEP and TBA were found to be stable in V/Br electrolytes. However, in the presence of bromine, solid formation was observed in the bromine rich organic phase when the V/Br electrolyte contained a single quaternary ammonium bromide (QBr) compound. For V/Br electrolytes with binary or ternary QBr mixtures containing TBA, the presence of bromine caused a viscous polybromide phase to form at room temperature and the release of bromine gas at higher temperature. Only a binary mixture of MEM and MEP formed a stable liquid organic phase between 11 ?? 40 oC. In this study it was found that V/Br electrolytes containing a binary QBr mixture (0.75M) of MEM and MEP gave the best combination that formed an orange oily layer in the presence of bromine without solidification between 11 ?? 40oC. Furthermore, it was found that samples of V/Br electrolytes containing a ternary QBr mixture, are less effective in bromine capturing if the total QBr concentration was less than 1 M at 40oC, where bromine gas evolution was observed. From electrochemical studies of V3+/V2+, it was found that the addition of MEM and MEP had a minimal effect on the formal potential of the V3+/V2+ couple, the V2+/V3+ transfer coefficient and the diffusion coefficient of V3+. Therefore, MEM and MEP can be added to the negative half-cell of a V/Br flow cell without major interference From linear sweep voltammetry, the kinetics of the Br-/Br3- redox couple was found to be mass transfer controlled. After the addition of MEM and MEP mixture, the exchange current density was found to decrease from 0.013 Acm-2 to 0.01 Acm-2. On the other hand the transfer coefficient before and after MEM and MEP addition was found to be 0.5 and 0.44 respectively. Since the kinetic parameters were not significantly affected by the addition of MEM and MEP mixture, they can be added to the positive half-cell of the V/Br flow cell as bromine complexing agents. The electrochemical studies of both V3+/V2+ and Br-/Br3- showed the addition of MEM and MEP has minimal interference with the redox reactions of the vanadium bromide flow cell. This thesis also investigated the effect of MEM and MEP addition on the cell performance of a lab scale V/Br flow cell using two different membranes (ChiNaf and VF11). Flow cell performance for 2 M V3.7+ + 0.19 M MEM + 0.56 M MEP electrolytes utilising ChiNaf membrane at 10 mAcm-2 produced an energy efficiency of 59%, and this decreased to 43% after 15 cycles. For the static cell utilising VF11 membrane, the addition of MEM and MEP reduced the energy efficiency from 59.7% to 43.4%. It is believed that this is caused by the mass transfer controlled Br-/Br3- couple in the complexed positive half-cell solution. Therefore, uniformity between the organic and aqueous phase is important for flow cells utilising electrolytes with MEM and MEP. Finally, the polarization resistance of a lab scale V/Br flow cell utilising ChiNaf membrane and 2 M V3.7+ electrolytes was found to be slightly higher during cell charging (3.9 cm2) than during the discharge process (3.6 cm2), which is opposed to that in the all-vanadium redox cell.

The Vanadium bromide (V/Br) flow cell employs the Br3-/Br- couple in the positive and the V(II)/V(III) couple in the negative half cell. One major issue of this flow cell is bromine gas formation in the positive half cell during charging which results from the low solubility of bromine in aqueous solutions. Bromine complexing agents previously used in the zinc-bromine fuel cell were evaluated for their applicability in V/Br flow cell electrolytes. Three quaternary ammonium bromides: N-ethyl-N-methyl-morpholinium bromide (MEM), N-ethyl-N-methyl-pyrrolidinium bromide (MEP) and Tetra-butyl ammonium bromide (TBA) were studied. It is known that aqueous bromine reacts with quaternary ammonium bromides to form an immiscible organic phase. Depending on the number of quaternary ammonium bromides used and the environmental temperature, the second phase formed will either be solid or liquid. As any solid formation would interrupt the flow cell operation, potential formation of such kind has to be eliminated. Stability tests of simulated V/Br electrolyte with added quaternary ammonium bromides were carried out at 11, 25 and 40 oC. In the absence of bromine, the addition of MEM, MEP and TBA were found to be stable in V/Br electrolytes. However, in the presence of bromine, solid formation was observed in the bromine rich organic phase when the V/Br electrolyte contained a single quaternary ammonium bromide (QBr) compound. For V/Br electrolytes with binary or ternary QBr mixtures containing TBA, the presence of bromine caused a viscous polybromide phase to form at room temperature and the release of bromine gas at higher temperature. Only a binary mixture of MEM and MEP formed a stable liquid organic phase between 11 ?? 40 oC. In this study it was found that V/Br electrolytes containing a binary QBr mixture (0.75M) of MEM and MEP gave the best combination that formed an orange oily layer in the presence of bromine without solidification between 11 ?? 40oC. Furthermore, it was found that samples of V/Br electrolytes containing a ternary QBr mixture, are less effective in bromine capturing if the total QBr concentration was less than 1 M at 40oC, where bromine gas evolution was observed. From electrochemical studies of V3+/V2+, it was found that the addition of MEM and MEP had a minimal effect on the formal potential of the V3+/V2+ couple, the V2+/V3+ transfer coefficient and the diffusion coefficient of V3+. Therefore, MEM and MEP can be added to the negative half-cell of a V/Br flow cell without major interference From linear sweep voltammetry, the kinetics of the Br-/Br3- redox couple was found to be mass transfer controlled. After the addition of MEM and MEP mixture, the exchange current density was found to decrease from 0.013 Acm-2 to 0.01 Acm-2. On the other hand the transfer coefficient before and after MEM and MEP addition was found to be 0.5 and 0.44 respectively. Since the kinetic parameters were not significantly affected by the addition of MEM and MEP mixture, they can be added to the positive half-cell of the V/Br flow cell as bromine complexing agents. The electrochemical studies of both V3+/V2+ and Br-/Br3- showed the addition of MEM and MEP has minimal interference with the redox reactions of the vanadium bromide flow cell. This thesis also investigated the effect of MEM and MEP addition on the cell performance of a lab scale V/Br flow cell using two different membranes (ChiNaf and VF11). Flow cell performance for 2 M V3.7+ + 0.19 M MEM + 0.56 M MEP electrolytes utilising ChiNaf membrane at 10 mAcm-2 produced an energy efficiency of 59%, and this decreased to 43% after 15 cycles. For the static cell utilising VF11 membrane, the addition of MEM and MEP reduced the energy efficiency from 59.7% to 43.4%. It is believed that this is caused by the mass transfer controlled Br-/Br3- couple in the complexed positive half-cell solution. Therefore, uniformity between the organic and aqueous phase is important for flow cells utilising electrolytes with MEM and MEP. Finally, the polarization resistance of a lab scale V/Br flow cell utilising ChiNaf membrane and 2 M V3.7+ electrolytes was found to be slightly higher during cell charging (3.9 cm2) than during the discharge process (3.6 cm2), which is opposed to that in the all-vanadium redox cell.

CH3Br and CH3Cl (methyl halides) are the most abundant natural vectors of bromine and chlorine into the stratosphere and play an important role in stratospheric ozone destruction. The current knowledge of their respective natural sources is incomplete leading to large uncertainties in their global budgets. Beside the issue of quantification, characterisation of possible sources is needed to assist modelling of future environmental change impacts on these sources and hence the stratosphere. This study describes measurements conducted at two temperate salt marsh and three temperate forest sites in Scotland, and one tropical rainforest site in Malaysian Borneo to quantify and characterise natural methyl halide producing processes in these respective ecosystems. Measurements were conducted with static enclosure techniques, and methyl halide fluxes were calculated from the concentration difference between blank/background and afterenclosure samples. Methyl halide concentrations were determined via oxygen-doped GCECD with a custom-built pre-concentration unit. External factors such as photosyntheticallyactive radiation (PAR), total solar radiation, air temperature, soil temperature, internal chamber temperature and soil moisture were recorded in parallel to the enclosures to determine possible dependencies. Salt marsh studies were carried out at Heckie’s Hole in East Lothian, and Hollands Farmin East Dumfriesshire for 2 years. The study subjects were salt marsh plants that were enclosed during daylight hours in transparent enclosures for 10min each at 2–4 week intervals throughout the year. Parallel to this monitoring programme, systematic manipulation experiments and diurnal studies were carried out to learn more about the possible influence of potential drivers such as sunlight and temperature. Mean annual net fluxes ( standard deviation (sd)) were 300 44 ngm-2 h-1 for CH3Br and 660 270 ngm-2 h-1 for CH3Cl, with fluxes of both gases following a diurnal as well as an annual cycle, being lowest during winter nights and highest during summer days. A possible link between variations of daytime fluxes over the course of a year and changes in temperature was found. CH3Cl and CH3Br fluxes were positively correlated to each other and average fluxes of CH3Cl were linked to dry mass of certain species such as Puccinellia maritima, Aster tripolium, Juncus gerardi and Plantago maritima as found at the different measurement locations. No link between methyl halide fluxes and total halogen content or halogen concentration of the enclosed vegetation was found. Work in temperate forests was carried out for over one year at Fir Links, a mixed beech/ sycamore forest in East Lothian, and on one occasion each in Griffin Forest, a sitka spruce plantation in Perthshire, and finally the Hermitage of Braid, a mixed woodland park in Edinburgh. The study subject was leaf and needle litter which was enclosed in opaque 12 L containers for 10min–24h. During enclosure, internal chamber temperature was recorded, and leaf/needle litter water content was determined after enclosure. Combined average CH3Br and CH3Cl fluxes from temperate forest litter were 4.3 10-3 ngg-1 h-1 and 0.91 ngg-1 h-1, respectively. Average fluxes measured from leaf and needle litter were comparable in magnitude and CH3Br and CH3Cl were positively correlated. However no correlation of methyl halide fluxes to either temperature or litter water content was observed. Work at Danum Valley inMalaysian Borneo focused on flux measurements from both trees and leaf litter in a tropical dipterocarp forest. Fluxes from tropical trees were measured with transparent branch chambers at 20min enclosure times whilst methyl halide fluxes from leaf litter were measured with opaque 12 L containers at 24h enclosure times. Mean CH3Br and CH3Cl fluxes from branch enclosures were 0.53 ngg-1 h-1 and 27 ngg-1 h-1, respectively, and CH3Br and CH3Cl fluxes from tropical leaf litter were 1.4 10-3 ngg-1 h-1 and 2.3 ngg-1 h-1 respectively. Again fluxes of CH3Br and CH3Cl were positively correlated but no direct environmental driver for flux variations was found. The magnitude of methyl halide fluxes was species specific with individuals of the genus Shorea generally producing large amounts of methyl halide. Tropical rainforests were confirmed to be potentially the largest single natural source of CH3Cl. Global estimates were derived from extrapolating measured fluxes from the respective global land cover areas. These estimates suggest that the ecosystems examined in this study could account for over 1/3 of global CH3Cl production and up to 13%of global CH3Br production in nature. The ratio of CH3Br to CH3Cl emissions for these ecosystems is likely to be dependent on the abundance of bromine in the plant material with higher bromine content boosting CH3Br production and suppressing CH3Cl production. For this reason salt marshes are only a very minor source of CH3Cl.

EVALUACIÓN DE SECUENCIA INVERSA CON VECURONIO EN PACIENTES SOMETIDOS A ANESTESIA GENERAL EN EL HOSPITAL GUILLERMO ALMENARA IRIGOYEN. Dr. Julio César Castillejo Correa Hospital Guillermo Almenara Irigoyen. UNMSM Objetivo: Determinar como influye la secuencia de administración de Vecuronio en el tiempo, para lograr condiciones adecuadas de intubación en pacientes que reciben anestesia general. Metodología: Se diseño un estudio Experimental (Ensayo clínico), Prospectivo, Analítico, Longitudinal, Tipo Cohorte. La muestra incluyó 200 pacientes, que cumplieron los criterios de inclusión y fueron divididos al azar en dos grupos: Grupo 1: Inducción de secuencia normal (Propofol - Vecuronio) Grupo 2: Inducción de secuencia inversa (Vecuronio - Propofol) Con ayuda de un observador quien registraba los datos de la monitorización y otro (el mismo en todos los casos) realizaba la intubación. Las condiciones de intubación fueron evaluadas mediante la escala de Damoal-Mehta modificada. La intubación endotraqueal se realizó de acuerdo a las condiciones clínicas del paciente monitorizado y en correlación a un estimulador de nervio periférico con acelerómetro (TOF- GUARD). Se utilizo el programa Epi - Info 2000. Resultados: Ambos grupos de estudio fueron comparables para edad, sexo, estado físico (ASA) y condiciones de intubación. La técnica de inducción con secuencia inversa (Vecuronio 0.15 mg/Kg durante 20 seg, 20 seg después se aplicó Propofol 2 mg/Kg durante 20 seg), es capaz de producir condiciones adecuadas de intubación en menor tiempo (28 seg promedio), en comparación con la secuencia normal de inducción (Propofol 2 mg/Kg durante 20 seg, 20 seg después se aplicó Vecuronio 0.15 mg/Kg durante 20 seg) que logró adecuadas condiciones de intubación en 101 seg promedio. Se apreció una reducción del tiempo de 73% al compararse ambas secuencias de inducción. Se dio el menor tiempo en lograr adecuadas condiciones de intubación (18 seg) en una paciente de sexo femenino, de 21 años y ASA I, que fue inducida con secuencia inversa. Se comprobó que con la técnica de secuencia inversa se dieron mínimas variaciones hemodinámicas (frecuencia cardiaca, presión arterial sistólica y diastólica). La medida de relajación muscular por neuroestimulador (TOF), corroboró que los pacientes del estudio sometidos a inducción con secuencia inversa (56.043%) y secuencia normal (58.86%), presentaron porcentajes semejantes de relajación, logrando el grupo de secuencia inversa menos tiempo para alcanzar estos valores. Las condiciones de intubación no mostraron diferencias significativas entre ambos grupos. Todos los pacientes tuvieron condiciones buenas y excelentes al momento de intubar. Conclusión: La inducción de secuencia inversa produce condiciones adecuadas de intubación en un menor tiempo, que la inducción con secuencia normal, resultando esta técnica eficiente en acortar el periodo entre la administración del agente de inducción y la intubación (Inicio de acción del relajante), observándose que al administrar la dosis completa de intubación del relajante muscular antes del inductor, se gana algunos segundos en el periodo en que el paciente permanece inconsciente y sin aislar la vía aérea. Palabras Clave: Secuencia Inversa, secuencia normal, TFIT / -- EVALUATION OF THE INVERSE SEQUENCE WITH VECURONIO IN PATIENTS SUBMITED TO GENERAL ANESTHESIA IN THE GUILLERMO ALMENARA IRIGOYEN´S HOSPITAL. Julio César Castillejo Correa Hospital NacionalGuillermo Almenara Irigoyen. UNMSM Objective: Determine how the administration sequence of Vecuronio influences in time, to reach suitable conditions for intubation in patients that receive general anesthesia. Methodology: A experimental study (clinical rehearsal), prospective, analític, longitudinal, Cohort type. The sample include 200 patients, that obeyed the inclusion criteria and they were divided at random in two groups: Group 1: normal- sequence Induction (Propofol - Vecuronio) Group 2: inverse- sequence Induction (Vecuronio - Propofol) With an observer's help that was registering the monitorization's data and another one (the same one in all cases) perform the intubation. The intubation conditions were evaluated with the Damoal's - Mehta scale modified. The endotraqueal intubation were realize according to the clinical conditions of the patient and in correlation to a peripheric- nerve stimulator with accelerometer (TOF - GUARD). We use Epi - Info 2000 program. Results: Both study groups were comparable for age, sex, physical state (ASA) and intubation conditions. The induction technique with inverse sequence (Vecuronio 0.15 mg/Kg during 20 sec, 20 sec after, Propofol applied 2 mg/Kg during 20 sec), is able to produce suitable intubation conditions in less time (28 sec average), as compared with the normal induction sequence (Propofol 2 mg/Kg during 20 sec, 20 sec after, Vecuronio applied 0.15 mg/Kg during 20 sec) that obtain suitable intubation conditions in 101sec average. A time reduction of 73% was appreciated when both sequences were compared. We obtain the less time in produce suitable intubation conditions (18 sec) in a patient of female sex, of 21 years, ASA I, that was induced with inverse sequence. We checked that with the inverse-sequence technique appears minimal hemodinamics variations (cardiac frequency, blood pressure sistolic and diastolic). The measure of the muscular relaxation by neuroestimulator (TOF), corroborated that the study's patients submit to induction with inverse sequence (56.043%) and normal sequence (58.86%), presented similar relaxation percentages, achieving the inverse-sequence group less time to reach these values. The intubation conditions not shows significant differences among both groups. All of the patients had good and excellent conditions at the moment of the intubation.. Conclusion: The inverse- sequence induction produces suitable conditions of intubation in a less time, than the induction with normal sequence, resulting this technique efficient in shortening the period among the administration of the agent of induction and the intubation (start of the relaxant's action), observing that when we administrate the complete intubation dose of the muscular relaxant before the inductor, the patient wins some seconds in the period whereon remain unconscious and without isolating airway. Key words: Inverse Sequence, normal sequence, TFIT

As junções comunicantes são estruturas celulares que permitem o trânsito de moléculas entre as células, desempenhando funções de sinalização e transporte intercelular. São formadas por proteínas denominadas conexinas e representam estruturas-chave no funcionamento de tecidos altamente complexos e integrados, como o sistema nervoso central (SNC). O presente estudo avalia os efeitos da deleção da conexina 32 (Cx32) na inflamação e regeneração/cicatrização do SNC após 1, 3, 7, 10 e 20 dias pós-injeção intracerebral de brometo de etídio em camundongos deletados para Cx32 e camundongos normais. Para tanto, quantificou-se a expressão dos genes para fator de necrose tumoral alfa (TNFα), fator de crescimento transformador beta 1 (TGFβ), metaloproteinase 3 (MMP3), metaloproteinase 9 (MMP9) e inibidor tecidual de metaloproteinases 1 (TIMP1), através de PCR em tempo real. Os resultados indicam variáveis diferenças no padrão de expressão, incluindo variação na expressão de todos os genes pesquisados no período de 3 dias pós-injeção, ápice dos mecanismos de inflamação aguda. Estes resultados sugerem que a conexina 32 pode desempenhar funções importantes na sinalização molecular do processo inflamatório e regenerativo/cicatricial do sistema nervoso central. / Gap junctions are cellular structures that allow transit of molecules between cells, performing intercellular signaling and transportation. They are formed by proteins denominated connexins and represent key structures in highly complex and integrated tissues, such as the central nervous system (CNS). The present study evaluates the effects of connexin 32 (Cx32) deletion upon CNS inflammation and egeneration/cicatrization after 1, 3, 7, 10 and 20 days after intracerebral injection of ethidium bromide in Cx32 Knock Out and normal mice. To accomplish so, Real Time PCR gene expression quantification was performed uppon tumour necrosis factor alpha (TNFα), transforming growth factor beta 1 (TGFβ), metalloproteinase 3 (MMP3), metalloproteinase 9 (MMP9) and tissue inhibitor of metalloproteinases 1(TIMP1) genes. Results indicate variable differences in the expression pattern, including difference in expression of all evaluated genes in the 3 days after injection period, apex of the acute inflammation mechanisms. These results suggest that Cx32 may perform important functions on molecular inflammatory and regenerative/cicatrization signalling in the CNS.

A corrosão localizada em aços inoxidáveis pode se manifestar de várias formas, tais como, a corrosão por pite, em fresta e corrosão sob tensão. Estes tipos de corrosão ocorrem quando o metal é exposto em meios agressivos como o cloreto, entre outros. O objetivo deste trabalho é estudar o comportamento dos aços inoxidáveis austeníticos e ferríticos em meios agressivos de cloreto, brometo e suas misturas. Para testar a resistência à corrosão por pite foi usado o método de polarização potenciodinâmica em eletrólitos de concentração iônica total de 0,6M. Os materiais estudados foram os aços inoxidáveis: 298 (aço inoxidável Cr-Mn, especificação da ArcelorMittal Inox Brasil) e os aços padronizados segundo a UNS: S30400, S31603, S43000 e S44400; todos, na condição tal como recebida da usina. Os resultados mostraram que, em meio de 0,6M(NaCl+NaBr), para concentrações de 0M a 0,45M NaCl, o desempenho quanto a resistência à corrosão por pite obedece a seguinte ordem decrescente: 444, 316L, 304, 298 e 430. Por sua vez, para a concentração de 0,6M NaCl, ou seja, ausência total de brometo, ocorre a alteração do desempenho dos aços inoxidáveis, colocando a seqüência da seguinte ordem: 316L, 444, 304, 298 e 430. Nota-se, portanto, que o melhor aço para ambientes contendo íon brometo seria o aço 444, já para aplicações em meio de cloreto puro, a melhor seleção é o aço 316L. Foram encontrados sítios de nucleação nos diferentes aços testados nos eletrólitos de 0,6M NaCl e 0,6M NaBr,sempre relacionados a inclusões: em alguns casos a nucleação ocorreu na interface matriz/inclusões insolúveis e, em outros, foram encontrados sinais de dissolução de inclusões, provavelmente de sulfeto. As diferenças de resistência à corrosão por pite entre os diferentes aços, nos diferentes eletrólitos, foram discutidas em função das diferenças de composição química. / Localized corrosion of stainless steels can be manifested in various forms, such as: pitting, crevice and stress corrosion. These types of corrosion occur due to exposition of metal in aggressive environments such as: chloride and bromide. The mean goal of this work is to study the pitting corrosion resistance of both austenitic and ferritic stainless steels in aggressive environments containing chloride, bromide or their mixtures. The potentiodynamic polarization method was used to test the pitting corrosion resistance in media containing a total of ion concentration of 0,6M. The studied materials in this work were stainless steel: 298 (Cr-Mn steel, specification of ArcelorMittal Inox Brazil) and standardized steels according to the UNS: S30400, S31603, S43000 and S44400. The results have shown that maintaining a constant concentration of 0.6M (NaCl+NaBr) into the electrolyte by varying the NaCl concentration between 0M and 0.45M, the performance in terms of pitting corrosion obeys to the following decreasing order: 444, 316L, 304, 298 and finally 430. In turn, for a concentration of 0.6M NaCl, so without any bromide, there is a variation from the performance of stainless steels, putting the sequence as following: 316L, 444, 304, 298 and 430. Nucleation sites were always found related to non-metallic inclusions in all tested stainless steels for the electrolytes of 0,6M NaCl or 0,6M NaBr. Sometimes, pits nucleation occurred at the matrix/inclusion interface, but others times, pits nucleated in water soluble inclusions. Difference of the pitting corrosion resistance between tested steel in the different electrolytes have been discussed as a function of the chemical composition.