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BACKGROUND: Aquagenic wrinkling of the palms (AWP) is an excessive and early palmar wrinkling occurring after brief immersion to water (BIW), and has been reported as a frequent finding among Cystic Fibrosis (CF) patients. OBJECTIVES: To investigate any associations of CF patients presenting AWP with other disease characteristics and explore the pathomechanism of AWP phenomenon. METHODS: We evaluated AWP in CF patients and assessed the AWP parameters of palmar wrinkling, oedema, papules, pruritus and pain at 3, 7 and 11 min after a BIW test with other disease characteristics. Statistical analyses explored the associations of AWP with genotype, lung function, pancreatic insufficiency, hyperhidrosis, personal and family history of atopy and sweat chloride levels. RESULTS: One hundred CF patients (mean age 10.4 years) were included in the analysis. The genotypic distribution was ΔF508/ΔF508: 47%, ΔF508/other: 41% and other/other: 12%. Statistically significant associations of Kaplan-Meier curves of the AWP parameters with various disease characteristics and personal/family history were detected. Wrinkling was associated with history of atopy, hyperhidrosis and levels of sweat chloride test. The time to presentation of oedema and the appearance of papules were associated with history of hyperhidrosis and age at diagnosis. Finally, time to appearance of pruritus was related to history of atopy and of hyperhidrosis. Regarding TEWL regression analysis showed significant associations with age at diagnosis (p = 0.024), sweat chloride test levels (p = 0.005), history of hyperhidrosis (p = 0.033), history of atopy (p = 0.002) and hepatic-pancreatic involvement (p = 0.027). CONCLUSIONS: The existence of a statistically significant association between AWP and the history of hyperhidrosis, atopy, sweat chloride levels and hepatic-pancreatic function in CF patients was detected. A strong association between AWP and CF was detected. AWP after BIW could be elicited easily and possibly can be used as an initial screening tool to diagnose an individual with symptoms and signs that raise the likelihood of CF.
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Fibrosis Quística , Hiperhidrosis , Queratosis , Humanos , Niño , Fibrosis Quística/complicaciones , Cloruros , Grecia , Hiperhidrosis/complicaciones , Queratosis/complicaciones , Agua , Prurito/complicaciones , Edema , SudorRESUMEN
BACKGROUND: Aquagenic wrinkling of the palms (AWP) is an excessive and early palmar wrinkling occurring after Brief Immersion to Water (BIW), and has been reported as a frequent finding among cystic fibrosis (CF) patients. OBJECTIVES: To evaluate and assess the diagnostic performance of BIW test as an initial screening tool for CF diagnosis. METHODS: We measured AWP in CF patients, CF-heterozygotes (CF-het) and normal controls. The AWP parameters of palmar wrinkling, oedema, papules, pruritus and pain were assessed at 3, 7 and 11 min after a BIW test was performed for all the participants. Statistical analyses explored the progression of AWP in time for the three groups and assessed the diagnostic performance of BIW test as a diagnostic screening tool for CF. RESULTS: A total of 250 individuals (100 CF patients, their 50 CF-het parents, 100 healthy controls) were included in the analysis. The average age in years (mean ± SD) was 10.4 ± 4.0 for CF, 35.9 ± 6.1 for CF-het and 10.5 ± 4.0 for controls. The rate of positives for AWP at 3 min among CF patients, CF-het and controls was 68%, 8% and 0%, respectively (P < 0.01). Kaplan-Meier analysis showed a clear trend towards earlier appearance of all five parameters in the direction controls < hetCF < CF (P values <0.01). The best diagnostic performance in detecting between CF patients and non-CF was achieved by the presence of papules and wrinkling at 7 min (sensitivity/specificity: 94.0%/98.3% and 100.0%/92.0%, respectively). CONCLUSIONS: A strong association between AWP and CF was detected. AWP after BIW could be elicited easily and possibly can be used as an initial screening tool to assess if an individual with symptoms and signs that raise the likelihood of CF is a CF patient.
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Fibrosis Quística , Envejecimiento de la Piel , Fibrosis Quística/complicaciones , Fibrosis Quística/diagnóstico , Heterocigoto , Humanos , Inmersión , AguaRESUMEN
PURPOSE: The efficacy of nab-paclitaxel in patients with metastatic breast cancer (MBC) has been demonstrated in randomized clinical trials. However, real-world evidence on effectiveness remains limited. PATIENTS AND METHODS: The primary objective of this multicenter prospective study was to assess the overall response rate (ORR) of patients with MBC treated with nab-paclitaxel. Secondary objectives included progression-free survival (PFS), overall survival (OS) and quality of life, assessed with the Functional Assessment of Cancer Therapy-Breast (FACT-B) instrument. RESULTS: Eligible patients (N = 150; 36% with de novo MBC presentation) with a median age of 64.5 years were enrolled (86% were ER+, 33.3% (50/150) were ≥ 70 years of age and 53% were treated in the third or later line of treatment). A median of 6 cycles were administered but 26% of patients required dose reduction due to toxicity. The ORR was 26.7% [95% confidence interval (CI) 19.6-33.7], the median PFS was 6.2 months (95% CI 5.2-7.3), and the median OS 21.1 months (95% CI 17.2-not estimable). There was no statistical significant difference in the median PFS of patients < and ≥ 70 years of age. The patients' baseline FACT-B total score remained unchanged. The serious and non-serious adverse event incidence rates were 13% and 48%, respectively. CONCLUSIONS: This prospective study provides further evidence on quality of life, efficacy, and safety of nab-paclitaxel in patients with MBC and sheds more light in special subpopulations such as the elderly and those treated beyond the second line.
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Albúminas/uso terapéutico , Neoplasias de la Mama/mortalidad , Carcinoma Ductal de Mama/mortalidad , Carcinoma Lobular/mortalidad , Paclitaxel/uso terapéutico , Calidad de Vida , Anciano , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/metabolismo , Carcinoma Ductal de Mama/secundario , Carcinoma Lobular/tratamiento farmacológico , Carcinoma Lobular/metabolismo , Carcinoma Lobular/secundario , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Receptor ErbB-2/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismo , Tasa de SupervivenciaRESUMEN
We develop a novel Bayesian method to select important predictors in regression models with multiple responses of diverse types. A sparse Gaussian copula regression model is used to account for the multivariate dependencies between any combination of discrete and/or continuous responses and their association with a set of predictors. We utilize the parameter expansion for data augmentation strategy to construct a Markov chain Monte Carlo algorithm for the estimation of the parameters and the latent variables of the model. Based on a centered parametrization of the Gaussian latent variables, we design a fixed-dimensional proposal distribution to update jointly the latent binary vectors of important predictors and the corresponding non-zero regression coefficients. For Gaussian responses and for outcomes that can be modeled as a dependent version of a Gaussian response, this proposal leads to a Metropolis-Hastings step that allows an efficient exploration of the predictors' model space. The proposed strategy is tested on simulated data and applied to real data sets in which the responses consist of low-intensity counts, binary, ordinal and continuous variables.
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BACKGROUND: The first dermatology-specific proxy health-related quality of life (HRQoL) instrument for children 0-4 years old with skin diseases, the Infants and Toddlers Dermatology Quality of Life (InToDermQoL), was recently developed. In order to avoid the problem of cross-cultural inequivalence focus groups work and pilot tests were organized simultaneously in all national centres of the project. The InToDermQoL showed good comprehensibility, clarity and acceptance. OBJECTIVE: To validate the InToDermQoL questionnaire during international field tests. METHODS: Internal consistency, test-retest reliability, convergent and discriminant validity of the InToDermQoL questionnaire were checked during international field tests. RESULTS: Parents of 473 children with skin diseases filled in the national language versions of the InToDermQoL questionnaire. All three age-specific versions of the InToDermQoL questionnaire with 10, 12 and 15 items, respectively, showed high internal consistency (Cronbach's α 0.90-0.93), good test-retest reliability (correlation coefficients > 0.9), significant correlations with the most widely used atopic dermatitis-specific proxy instrument, the Infants Dermatitis Quality of Life Index (correlation coefficients 0.68-0.79). The InToDermQoL versions for children <3 years old well correlated with the atopic dermatis severity measure Scoring of Atopic Dermatitis (correlation coefficients 0.66 and 0.86 for 10 and 12 items versions, respectively). The InToDermQoL questionnaire discriminated well among different diagnoses and disease severity levels. CONCLUSION: Our field tests confirmed internal consistency, test-retest reliability, convergent and discriminant validity of the InToDermQoL questionnaire. Development and validation of the InToDermQoL questionnaire make it possible to assess dermatology-specific aspects of HRQoL in youngest children with skin diseases. There are many reasons to assess HRQoL in dermatologic clinical practice, and we hope that our new instrument will be used internationally in paediatric dermatology for research and practical needs.
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Padres , Calidad de Vida , Enfermedades de la Piel , Encuestas y Cuestionarios , Preescolar , Dermatología , Europa (Continente) , Femenino , Humanos , Lactante , Recién Nacido , Lenguaje , Masculino , Apoderado , Psicometría , Reproducibilidad de los Resultados , Índice de Severidad de la Enfermedad , Enfermedades de la Piel/complicacionesAsunto(s)
Atenolol/uso terapéutico , Hemangioma Capilar/tratamiento farmacológico , Propranolol/uso terapéutico , Neoplasias Cutáneas/tratamiento farmacológico , Atenolol/efectos adversos , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Femenino , Estudios de Seguimiento , Hemangioma Capilar/patología , Hospitales Pediátricos , Humanos , Lactante , Masculino , Seguridad del Paciente , Propranolol/efectos adversos , Medición de Riesgo , Neoplasias Cutáneas/patología , Resultado del TratamientoRESUMEN
BACKGROUND AND PURPOSE: Pre-surgical evaluation of pediatric patients with drug-resistant focal epilepsy and negative (non-lesional) magnetic resonance imaging (MRI) is particularly challenging. Focal cortical dysplasia (FCD), a frequent pathological substrate in such setting, may be subtle on MRI and evade detection. The aim of this study was to use voxel-based MRI postprocessing to improve the detection of subtle FCD in pediatric surgical candidates. METHODS: A consecutive cohort of pediatric patients undergoing pre-surgical evaluation with a negative MRI by visual analysis was included. MRI postprocessing was performed using a voxel-based morphometric analysis program (MAP) on T1-weighted volumetric MRI, with comparison to an age-specific normal pediatric database. The pertinence of MAP-positive areas was confirmed by surgical outcome and pathology. RESULTS: A total of 78 patients were included. Forty-four patients (56%) had positive MAP regions. Complete resection of the MAP-positive regions was positively associated with seizure-free outcome compared with the no/partial resection group (P < 0.001). Patients with no/partial resection of the MAP-positive regions had worse seizure outcomes than the MAP-negative group (P = 0.002). The MAP-positive rate was 100%, 77%, 63% and 40% in the 3-5, 5-10, 10-15 and 15-21 year age groups, respectively. MAP-positive rates were 45% in patients with temporal resection and 63% in patients with extratemporal resection. Complete resection of the MAP-positive regions was positively associated with seizure-free outcome in the extratemporal group (P = 0.001) but not in the temporal group (P = 0.070). CONCLUSION: Our data suggest the importance of using MRI postprocessing in the pre-surgical evaluation process of pediatric epilepsy patients with apparently normal MRI.
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Epilepsia Refractaria/diagnóstico por imagen , Convulsiones/diagnóstico por imagen , Adolescente , Niño , Preescolar , Bases de Datos Factuales , Epilepsia Refractaria/cirugía , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Estudios Retrospectivos , Convulsiones/cirugía , Adulto JovenRESUMEN
BACKGROUND: Until now, there was no validated dermatology-specific health-related quality of life (HRQoL) instrument to be used in youngest patients. OBJECTIVE: To create dermatology-specific proxy instrument for HRQoL assessment in children from birth to 4 years. METHODS: International focus groups, item selection and pilot tests were utilized. In order to avoid the problem of cross-cultural inequivalence, focus group work and pilot tests were planned simultaneously in all national centres of the project. Comprehensibility, clarity, acceptance and internal consistency of new instrument were checked. RESULTS: The title 'Infants and Toddlers Dermatology Quality of Life' was chosen for our new instrument with the proposed acronym 'InToDermQoL'. Focus group work was completed in seven national centres (Croatia, Germany, Greece, Malta, Poland, Romania and Ukraine). A total of 170 families of children with different skin diseases were interviewed, and a pilot version of the instrument was created. Centres from France, Denmark and Spain have joined the project at this stage. Parents of 125 children with skin diseases filled in the pilot versions of the instrument. Good comprehensibility, clarity, acceptance and internal consistency of the InToDermQoL were confirmed. The pilot test results showed that the InToDermQoL questionnaire well differentiates severity-dependent differences. It was also checked and confirmed during the pilot test that no significant information was missed in the questionnaire. Three age-specific versions of the InToDermQoL questionnaire with 10, 12 and 15 items, respectively, were approved for field tests. CONCLUSION: The pilot test results showed that the InToDermQoL questionnaire has good comprehensibility, clarity, acceptance and internal consistency and well differentiates severity-dependent differences. Further validation of the InToDermQoL during international field test will be performed.
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Calidad de Vida , Enfermedades de la Piel , Encuestas y Cuestionarios , Preescolar , Comprensión , Competencia Cultural , Europa (Continente) , Grupos Focales , Humanos , Lactante , Recién Nacido , Proyectos Piloto , Apoderado , Índice de Severidad de la Enfermedad , Enfermedades de la Piel/complicacionesAsunto(s)
Antagonistas de Receptores Adrenérgicos beta 1/uso terapéutico , Atenolol/uso terapéutico , Hemangioma/tratamiento farmacológico , Antagonistas de Receptores Adrenérgicos beta 1/efectos adversos , Atenolol/efectos adversos , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos , Resultado del TratamientoAsunto(s)
Encefalocele/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Lóbulo Temporal/diagnóstico por imagen , Adulto , Diagnóstico Diferencial , Encefalocele/complicaciones , Encefalocele/patología , Encefalocele/cirugía , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/etiología , Epilepsia del Lóbulo Temporal/patología , Epilepsia del Lóbulo Temporal/cirugía , Humanos , Masculino , Lóbulo Temporal/patología , Lóbulo Temporal/cirugíaRESUMEN
Ozone was used to control spoilage microorganisms during the manufacturing of dairy products. Ozone stream was applied onto the surface of freshly filled yoghurt cups just before storage for curd development in order to prevent cross contamination from spoilage airborne microorganisms. Accordingly, brine solution was bubbled with ozone for various periods of time and used for ripening of white (feta type) cheese. Both products were subjected to a continuous monitoring of microbial load and also tested for their sensorial properties. In ozonated yoghurt samples there was a reduction in mould counts of approximately 0.6Logcfu/g (25.1%) by the end of the monitoring period in relation to the control samples. In white cheese ripened with ozonated brine (1.3mg/L O3, NaCl 5%) it seems that ozone treatment during the two months of observation reduced some of the mould load but without offering any advantages over the use of traditional brine (NaCl 7%). However, some sensorial alterations were observed, probably due to the organic load in the brine which deactivates ozone in early stages of application. It is concluded that, if the factors of time and concentration of ozone are configured properly, ozonation could be a promising approach safeguarding the production of some dairy products.
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Queso/análisis , Fermentación , Contaminación de Alimentos/prevención & control , Ozono/farmacología , Reactores Biológicos , Queso/microbiología , Productos Lácteos/microbiología , Microbiología de Alimentos , Hongos/efectos de los fármacos , Concentración de Iones de Hidrógeno , Sales (Química)/química , Cloruro de Sodio/química , Temperatura , Yogur/microbiologíaRESUMEN
BACKGROUND AND PURPOSE: Rasmussen syndrome, also known as Rasmussen encephalitis, is typically associated with volume loss of the affected hemisphere of the brain. Our aim was to apply automated quantitative volumetric MR imaging analyses to patients diagnosed with Rasmussen encephalitis, to determine the predictive value of lobar volumetric measures and to assess regional atrophy differences as well as monitor disease progression by using these measures. MATERIALS AND METHODS: Nineteen patients (42 scans) with diagnosed Rasmussen encephalitis were studied. We used 2 control groups: one with 42 age- and sex-matched healthy subjects and the other with 42 epileptic patients without Rasmussen encephalitis with the same disease duration as patients with Rasmussen encephalitis. Volumetric analysis was performed on T1-weighted images by using BrainSuite. Ratios of volumes from the affected hemisphere divided by those from the unaffected hemisphere were used as input to a logistic regression classifier, which was trained to discriminate patients from controls. Using the classifier, we compared the predictive accuracy of all the volumetric measures. These ratios were used to further assess regional atrophy differences and correlate with epilepsy duration. RESULTS: Interhemispheric and frontal lobe ratios had the best prediction accuracy for separating patients with Rasmussen encephalitis from healthy controls and patient controls without Rasmussen encephalitis. The insula showed significantly more atrophy compared with all the other cortical regions. Patients with longitudinal scans showed progressive volume loss in the affected hemisphere. Atrophy of the frontal lobe and insula correlated significantly with epilepsy duration. CONCLUSIONS: Automated quantitative volumetric analysis provides accurate separation of patients with Rasmussen encephalitis from healthy controls and epileptic patients without Rasmussen encephalitis, and thus may assist the diagnosis of Rasmussen encephalitis. Volumetric analysis could also be included as part of follow-up for patients with Rasmussen encephalitis to assess disease progression.
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Encéfalo/diagnóstico por imagen , Encefalitis/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Adulto , Atrofia/patología , Encéfalo/patología , Encefalitis/patología , Femenino , Humanos , MasculinoRESUMEN
Management of MRI-negative patients with intractable focal epilepsy after failed surgery is particularly challenging. In this study, we aim to investigate whether MRI post-processing could identify relevant targets for the re-evaluation of MRI-negative patients who failed the initial resective surgery. We examined a consecutive series of 56 MRI-negative patients who underwent resective surgery and had recurring seizures at 1-year follow-up. T1-weighted volumetric sequence from the pre-surgical MRI was used for voxel-based MRI post-processing which was implemented in a morphometric analysis program (MAP). MAP was positive in 15 of the 56 patients included in this study. In 5 patients, the MAP+ regions were fully resected. In 10 patients, the MAP+ regions were not or partially resected: two out of the 10 patients had a second surgery including the unresected MAP+ region, and both became seizure-free; the remaining 8 patients did not undergo further surgery, but the unresected MAP+ regions were concordant with more than one noninvasive modality in 7. In the 8 patients who had unresected MAP+ regions and intracranial-EEG before the previous surgery, the unresected MAP+ regions were concordant with ictal onset in 6. Our data suggest that scrutiny of the presurgical MRI guided by MRI post-processing may reveal relevant targets for reoperation in nonlesional epilepsies. MAP findings, when concordant with the patient's other noninvasive data, should be considered when planning invasive evaluation/reoperation for this most challenging group of patients.
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Encéfalo/diagnóstico por imagen , Epilepsia Refractaria/diagnóstico por imagen , Epilepsia Refractaria/cirugía , Epilepsias Parciales/diagnóstico por imagen , Epilepsias Parciales/cirugía , Imagen por Resonancia Magnética , Adolescente , Adulto , Anciano , Encéfalo/fisiopatología , Encéfalo/cirugía , Niño , Epilepsia Refractaria/fisiopatología , Electrocorticografía , Epilepsias Parciales/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética/métodos , Magnetoencefalografía , Masculino , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Malformaciones del Desarrollo Cortical/fisiopatología , Malformaciones del Desarrollo Cortical/cirugía , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Tomografía de Emisión de Positrones , Reoperación , Estudios Retrospectivos , Insuficiencia del Tratamiento , Adulto JovenRESUMEN
OBJECTIVES: The significance of infraslow activity (ISA) in focal epilepsies is largely unknown. Recent work has demonstrated ictal ISA to be more widespread in expression than originally understood. Analysis of ISA by stereoelectroencephalography (SEEG) may help to clarify its localizing value, namely the focal versus widespread expression of ISA. METHODS: The ictal SEEG records for fifteen consecutive adult patients were retrospectively analyzed, using both conventional (1.6-70 Hz) and infraslow (0.01-0.1 Hz) bandpass filters. When justified, seizures were averaged in the infraslow band to clarify their stereotypy. Wavelets were used to quantify the time-frequency characteristics of ISA. RESULTS: All clinical seizures were found to possess ISA, and this was markedly invariant across seizures in a given patient. ISA showed biphasic peaks in power, both at ictal onset and offset, with this most prominent in the anatomical structures implicated by conventional analysis. In addition, ISA demonstrated an association with low voltage fast activity, and possessed a more restricted field than conventional activity. CONCLUSIONS: ISA is both widespread (anatomically distributed) and focal (closed electric field). Seizures possess an infraslow spatiotemporal signature. SIGNIFICANCE: Beyond representing a "focus" of paroxysmal activity, ISA must arise from a network process as a component of wideband ictal dynamics. How this relates to clinical definition of the epileptogenic zone requires further study.
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Electroencefalografía , Convulsiones/fisiopatología , Adolescente , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Convulsiones/diagnósticoRESUMEN
OBJECTIVE: To investigate whether epileptogenic focus localization is possible based on resting state connectivity analysis of magnetoencephalographic (MEG) data. METHODS: A multivariate autoregressive (MVAR) model was constructed using the sensor space data and was projected to the source space using lead field and inverse matrix. The generalized partial directed coherence was estimated from the MVAR model in the source space. The dipole with the maximum information inflow was hypothesized to be within the epileptogenic focus. RESULTS: Applying the focus localization algorithm (FLA) to the interictal MEG recordings from five patients with neocortical epilepsy, who underwent presurgical evaluation for the identification of epileptogenic focus, we were able to correctly localize the focus, on the basis of maximum interictal information inflow in the presence or absence of interictal epileptic spikes in the data, with three out of five patients undergoing resective surgery and being seizure free since. CONCLUSION: Our preliminary results suggest that accurate localization of the epileptogenic focus may be accomplished using noninvasive spontaneous "resting-state" recordings of relatively brief duration and without the need to capture definite interictal and/or ictal abnormalities. SIGNIFICANCE: Epileptogenic focus localization is possible through connectivity analysis of resting state MEG data irrespective of the presence/absence of spikes.
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Potenciales de Acción , Electroencefalografía/métodos , Epilepsias Parciales/fisiopatología , Magnetoencefalografía/métodos , Descanso , Potenciales de Acción/fisiología , Adulto , Epilepsias Parciales/diagnóstico , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Descanso/fisiologíaRESUMEN
In this work the dynamic flow as well as the particle motion and deposition in a commercial dry powder inhaler, DPI (i.e., Turbuhaler) is described using computational fluid dynamics, CFD. The dynamic flow model presented here is an extension of a steady flow model previously described in Milenkovic et al. (2013). The model integrates CFD simulations for dynamic flow, an Eulerian-fluid/Lagrangian-particle description of particle motion as well as a particle/wall interaction model providing the sticking efficiency of particles colliding with the DPI walls. The dynamic flow is imposed by a time varying outlet pressure and the particle injections into the DPI are assumed to occur instantaneously and follow a prescribed particle size distribution, PSD. The total particle deposition and the production of fine particles in the DPI are determined for different peak inspiratory flow rates, PIFR, flow increase rates, FIR, and particle injection times. The simulation results for particle deposition are found to agree well with available experimental data for different values of PIFR and FIR. The predicted values of fine particle fraction are in agreement with available experimental results when the mean size of the injected PSD is taken to depend on the PIFR.
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Simulación por Computador , Inhaladores de Polvo Seco , Hidrodinámica , Modelos Teóricos , Administración por Inhalación , Aerosoles , Diseño de Equipo , Tamaño de la Partícula , Polvos , Factores de TiempoRESUMEN
Sourdough breads prepared with kefir grains resulted in appearance of rope spoilage at the 15th day of bread storage, while the control samples (sourdough breads prepared with wild microflora) were spoiled approximately at the 7th day. Denaturing Gradient Gel Electrophoresis (DGGE) analysis confirmed the above macroscopic observation since Bacillus spp. were detected on sourdough breads prepared with kefir grains at the 15th day of bread storage. The content of organic acids that play synergistic role regarding the enhancement of bread self life was also determined. Lactic acid concentration of sourdough breads prepared with kefir grains were approximately 41-82% higher than the control samples, while acetic acid concentration was about 0.5-1-fold higher respectively. The concentration of some other organic acids studied was also found in higher levels (up to 0.06µg/g) than the control samples. These findings could probably explain the stability of breads prepared with kefir grains against rope spoilage.
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Bacillus/aislamiento & purificación , Pan/microbiología , Productos Lácteos Cultivados/química , Manipulación de Alimentos/métodos , Triticum/microbiología , Bacillus/clasificación , Bacillus/metabolismo , Pan/análisis , Productos Lácteos Cultivados/microbiología , Fermentación , Contaminación de Alimentos/análisis , Humanos , Ácido Láctico/análisis , Gusto , Triticum/metabolismoRESUMEN
In this work the steady-state flow in a commercial dry powder inhaler device, DPI (i.e., Turbuhaler) is described using computational fluid dynamics. The Navier-Stokes equations are solved using commercial CFD software considering different flow models, i.e., laminar, k-ε, k-ε RNG, and k-ω SST as well as large Eddy simulation. Particle motion and deposition are described using a Eulerian-fluid/Lagrangian-particle approach. Particle collisions with the DPI walls are taken to result in deposition when the normal collision velocity is less than a critical capture velocity. Flow and particle deposition, for a range of mouthpiece pressure drops (i.e., 800-8800 Pa), as well as particle sizes corresponding to single particles and aggregates (i.e., 0.5-20 µm), are examined. The total volumetric outflow rate, the overall particle deposition as well as the spatial distribution of deposition sites in the DPI are determined. The transitional k-ω SST model for turbulent flow was found to produce results most similar to a reference solution obtained with LES, as well as experimental results for the pressure drop in the DPI. Overall, the simulation results are found to be in agreement with the available experimental data for local and total particle deposition.