Breakdown-induced negative charge in ultrathin SiO2 films measured by atomic force microscopy

Atomic-force-microscopy-based techniques have been used to investigate at a nanometer scale the dielectric breakdown (BD) of ultrathin (<6 nm) SiO2films of metal-oxide-semiconductordevices. The results show that BD leads to negative charge at the BD location and the amount of created charge has been estimated. Moreover, the comparison of the charge magnitude generated during current-limited stresses and stresses without current limit demonstrates that the observed BD induced negative charge is related to the structural damage created by the oxide BD

Incremento de costes atribuible a la infección quirúrgica de la apendicectomía y colectomía

Objetivo: Determinar los costes mediante la medición directa, caso a caso, de la infección del sitio quirúrgico en la apendicectomía y la colectomía. Métodos: Diseño: estudio de casos y controles con base poblacional; los casos fueron todos los pacientes diagnosticados de infección de sitio quirúrgico tras apendicectomía o colectomía en SCIAS-Hospital de Barcelona, y los controles una muestra seleccionada aleatoriamente entre los pacientes no infectados que reunían características comunes para el apareamiento. Período de estudio: del 1 de enero de 1998 al 31 de diciembre de 1999. Tipos de apareamiento: a) individual de pacientes agrupados según el diagnóstico principal, el procedimiento quirúrgico principal, la edad y el sexo, y b) individual de pacientes agrupados según el diagnóstico principal, la edad y el sexo, pero utilizando además para la selección de los controles el diagnóstico secundario. Fuentes de información: sistema informático de registros e historias clínicas en soporte electrónico, incluyendo los costes registrados en tiempo real. Contabilidad analítica: programa ADS plus®, que calculó costes reales (paciente por paciente) a partir de datos como el consumo de farmacia, el material sanitario, las pruebas adicionales de diagnóstico y las estancias generadas. Los costes estructurales se imputaron en la matriz de costes a partir del cálculo contable y su impacto en los costes directos. Se consideró coste atribuible a la infección al coste incremental o adicional resultante de la diferencia entre casos y controles. Análisis estadístico: los cálculos estadísticos se realizaron mediante el paquete estadístico SPSS, versión 9.0. Se utilizaron pruebas no paramétricas teniendo en cuenta el tamaño de la muestra. Se aplicó el test de Wilcoxon para variables continuas con el fin de comparar la edad, la duración de las intervenciones quirúrgicas, la estancia hospitalaria y los costes. Los resultados se expresaron como media aritmética. Se consideró un nivel de significación estadística un valor de p < 0,01. Resultados: En el primer apareamiento se incluyeron 23 casos y 23 controles para los pacientes operados de apendicectomía, y 20 casos y 20 controles de colectomía. En el apareamiento 2 la muestra fue de 17 pares de casos y controles en apendicectomía, y 14 pares de casos y controles en colectomía. La infección comportó un aumento de la estancia media entre 7,7 días (apareamiento 1) y 7,3 días (apareamiento 2) en apendicectomía infectada, y entre 17,6 días (apareamiento 1) y 15,4 días (apareamiento 2) en colectomía. Los pacientes con infección de apendicectomía presentaron un coste medio tres veces superior a los no infectados tanto en el apareamiento 1 (2.998,60 frente a 941,89 ?, respectivamente; p < 0,0001) como en el apareamiento 2 (2.751,70 frente a 870,81 ?, respectivamente; p < 0,0001). Similar hallazgo se observó en la colectomía, tanto en el apareamiento 1 (10.705,34 frente a 2.600,55 ?, respectivamente; p < 0,0001) como en el apareamiento 2 (9.081,12 frente a 2.621,39 ?, respectivamente; p < 0,0001). El coste medio atribuible a la infección de sitio quirúrgico osciló entre 2.056,71 ? (apareamiento 1) y 1.880,89 ? (apareamiento 2) en el caso de la apendicectomía, y 8.140,79 ? (apareamiento 1) y 6.405,65 ? (apareamiento 2) en la colectomía. Conclusiones: En las condiciones del estudio, la infección del sitio quirúrgico determina la prolongación de la estancia hospitalaria de más de una semana en la apendicectomía y de más de dos en la colectomía, con un incremento superior al 300% en el coste directo total

Incremento de costes atribuible a la infección quirúrgica de la apendicectomía y colectomía Increase in costs attributable to surgical infection after appendicectomy and colectomy

Objetivo: Determinar los costes mediante la medición directa, caso a caso, de la infección del sitio quirúrgico en la apendicectomía y la colectomía. Métodos: Diseño: estudio de casos y controles con base poblacional; los casos fueron todos los pacientes diagnosticados de infección de sitio quirúrgico tras apendicectomía o colectomía en SCIAS-Hospital de Barcelona, y los controles una muestra seleccionada aleatoriamente entre los pacientes no infectados que reunían características comunes para el apareamiento. Período de estudio: del 1 de enero de 1998 al 31 de diciembre de 1999. Tipos de apareamiento: a) individual de pacientes agrupados según el diagnóstico principal, el procedimiento quirúrgico principal, la edad y el sexo, y b) individual de pacientes agrupados según el diagnóstico principal, la edad y el sexo, pero utilizando además para la selección de los controles el diagnóstico secundario. Fuentes de información: sistema informático de registros e historias clínicas en soporte electrónico, incluyendo los costes registrados en tiempo real. Contabilidad analítica: programa ADS plus®, que calculó costes reales (paciente por paciente) a partir de datos como el consumo de farmacia, el material sanitario, las pruebas adicionales de diagnóstico y las estancias generadas. Los costes estructurales se imputaron en la matriz de costes a partir del cálculo contable y su impacto en los costes directos. Se consideró coste atribuible a la infección al coste incremental o adicional resultante de la diferencia entre casos y controles. Análisis estadístico: los cálculos estadísticos se realizaron mediante el paquete estadístico SPSS, versión 9.0. Se utilizaron pruebas no paramétricas teniendo en cuenta el tamaño de la muestra. Se aplicó el test de Wilcoxon para variables continuas con el fin de comparar la edad, la duración de las intervenciones quirúrgicas, la estancia hospitalaria y los costes. Los resultados se expresaron como media aritmética. Se consideró un nivel de significación estadística un valor de p Objective: To determine the costs, with the help of direct case to case measurement, of the surgical site infection in apendicectomy and colectomy. Methods: Design: cases and controls study, population-based, in which the cases were all the patients diagnosed of surgical site infection after apendicectomy or colectomy in SCIAS- Hospital de Barcelona, and the controls were a random sample of noninfected patients that presented common characteristics for matching purposes. Study period: from January 1, 1998, to December 31, 1999. Types of matching: a) individual, patients grouped according to main diagnosis, main surgical procedure, age and gender, and b) patients grouped according to main diagnosis, main surgical procedure, age and gender using in addition, as controls criteria, the number of secondary diagnoses. Data sources: computer system with all the registries and clinical histories in electronic support, including the costs registered in real time. Analytical Accounting: ADS plus® program that calculated the real costs (patient to patient) extracted from real data, such as drugs consumption, medical supplies, additional diagnosis tests and generated stays. The structural costs were imputed in the matrix of costs from the countable calculation and its impact on the direct costs. The cost attributable to the infection was calculated as the additional cost resultant from the difference between cases and controls. Statistical analysis: the statistical calculations were made by means of the statistical package SPSS, version 9.0. Nonparametric tests were used considering the sample size. The test of Wilcoxon for continuous variables, with the purpose of comparing age, operations length, hospital stay and costs, was applied. The results were expressed as arithmetic mean. A level of statistical meaning of p < 0.01 was considered. Results: The first matching included 23 cases and 23 controls for patients operated on apendicectomy and 20 cases and 20 controls for those operated on colectomy. In matching 2, the sample consisted on 17 pairs of cases and controls on apendicectomy and 14 pairs of cases and controls on colectomy. The infection increased the average length of stay between 7.7 days (matching 1) and 7.3 days (matching 2) in cases of infected apendicectomy and between 17.6 days (matching 1) and 15.4 days (matching 2) in cases of infected colectomy. The patients with apendicectomy infection presented an average cost three times higher than the ones not infected, both in matching 1 (2,998.60 versus 941.89 €, respectively; p < 0.0001) and in matching 2 (2,751.70 versus 870.81 €, respectively; p < 0.0001). Similar findings were observed in colectomy both in matching 1 (10,705.34 versus 2,600.55 €, respectively; p < 0.0001) and in matching 2 (9,081.12 versus 2,621.39 €, respectively; p < 0.0001). The average cost of surgical site infection oscillated between 2,056.71 € (matching 1) and 1,880.89 € (matching 2) in apendicectomy and between 8,140.79 € (matching 1) and 6,405.65 € (matching 2) in colectomy. Conclusions: Under the study conditions, the infection of surgical site determines the prolongation of the hospital stay in more than one week in apendicectomy and in more than two in colectomy, with an increase higher than 300% in the total direct cost

Conductive-AFM topography and current maps simulator for the study of polycrystalline high-k dielectrics

In this work, a simulator of conductive atomic force microscopy (C-AFM) was developed to reproduce topography and current maps. In order to test the results, the authors used the simulator to investigate the influence of the C-AFM tip on topography measurements of polycrystalline high-k dielectrics, and compared the results with experimental data. The results show that this tool can produce topography images with the same morphological characteristics as the experimental samples under study. Additionally, the current at each location of the dielectric stack was calculated. The quantum mechanical transmission coefficient and tunneling current were obtained from the band diagram by applying the Airy wavefunction approach. Good agreement between experimental and simulation results indicates that the tool can be very useful for evaluating how the experimental parameters influence C-AFM measurements

Attenuation of thermal nociception and hyperalgesia by VR1 blockers

Vanilloid receptor subunit 1 (VR1) appears to play a critical role in the transduction of noxious chemical and thermal stimuli by sensory nerve endings in peripheral tissues. Thus, VR1 antagonists are useful compounds to unravel the contribution of this receptor to pain perception, as well as to induce analgesia. We have used a combinatorial approach to identify new, nonpeptidic channel blockers of VR1. Screening of a library of trimers of N-alkylglycines resulted in the identification of two molecules referred to as DD161515 {(N-[2-(2-(N-methylpyrrolidinyl)ethyl]glycyl]-[N- [2,4-dichlorophenethyl]glycyl]-N-(2,4-dichlorophenethyl)glycinamide} and DD191515 {([N-[3-(N,N-diethylamino)propyl]glycyl]-[N- [2,4-dichlorophenethyl]glycyl]-N-(2,4-dichlorophenethyl)glycinamide} that selectively block VR1 channel activity with micromolar efficacy, rivaling that characteristic of vanilloid-related inhibitors. These compounds appear to be noncompetitive VR1 antagonists that recognize a receptor site distinct from that of capsaicin. Intraperitoneal administration of both trial-kylglycines into mice significantly attenuated thermal nociception as measured in the hot plate test. It is noteworthy that these compounds eliminated pain and neurogenic inflammation evoked by intradermal injection of capsaicin into the animal hindpaw, as well as the thermal hyperalgesia induced by tissue irritation with nitrogen mustard. In contrast, responses to mechanical stimuli were not modified by either compound. Modulation of sensory nerve fibers excitability appears to underlie the peptoid analgesic activity. Collectively, these results indicate that blockade of VR1 activity attenuates chemical and thermal nociception and hyperalgesia, supporting the tenet that this ionotropic receptor contributes to chemical and thermal sensitivity and pain perception in vivo. These trialkylglycine-based, noncompetitive VR1 antagonists may likely be developed into analgesics to treat inflammatory pain

Attenuation of thermal nociception and hyperalgesia by VR1 blockers

Vanilloid receptor subunit 1 (VR1) appears to play a critical role in the transduction of noxious chemical and thermal stimuli by sensory nerve endings in peripheral tissues. Thus, VR1 antagonists are useful compounds to unravel the contribution of this receptor to pain perception, as well as to induce analgesia. We have used a combinatorial approach to identify new, nonpeptidic channel blockers of VR1. Screening of a library of trimers of N-alkylglycines resulted in the identification of two molecules referred to as DD161515 {N-[2-(2-(N-methylpyrrolidinyl)ethyl]glycyl]-[N-[2,4-dichlorophenethyl]glycyl]-N-(2,4-dichlorophenethyl)glycinamide} and DD191515 {[N-[3-(N,N-diethylamino)propyl]glycyl]-[N-[2,4-dichlorophenethyl]glycyl]-N-(2,4-dichlorophenethyl)glycinamide} that selectively block VR1 channel activity with micromolar efficacy, rivaling that characteristic of vanilloid-related inhibitors. These compounds appear to be noncompetitive VR1 antagonists that recognize a receptor site distinct from that of capsaicin. Intraperitoneal administration of both trialkylglycines into mice significantly attenuated thermal nociception as measured in the hot plate test. It is noteworthy that these compounds eliminated pain and neurogenic inflammation evoked by intradermal injection of capsaicin into the animal hindpaw, as well as the thermal hyperalgesia induced by tissue irritation with nitrogen mustard. In contrast, responses to mechanical stimuli were not modified by either compound. Modulation of sensory nerve fibers excitability appears to underlie the peptoid analgesic activity. Collectively, these results indicate that blockade of VR1 activity attenuates chemical and thermal nociception and hyperalgesia, supporting the tenet that this ionotropic receptor contributes to chemical and thermal sensitivity and pain perception in vivo. These trialkylglycine-based, noncompetitive VR1 antagonists may likely be developed into analgesics to treat inflammatory pain