Side effects of the Pfizer BioNTech vaccine in health workers of a hospital in the southeast of Mexico.

INTRODUCTION: The goal of this study was to evaluate the side effects of application of the Pfizer BioNTech vaccine on the workers at a Mexican hospital. METHODOLOGY: A cross-sectional study was carried out, in which 1351 workers from a tertiary care center in the Mexican southeast were included. Sociodemographic data, comorbidities, and side effects after the Pfizer BioNTech vaccine were obtained through an online survey. The variables were analyzed through descriptive statistics. The presence or absence of side effects was analyzed through the Chi-square test or t-test, as appropriate. The result was considered statistically significant at p < 0.05. RESULTS: A total of 1351 health workers participated in the online survey. The mean age was 37.8 ± 10.9 years and 56.4% were women. Among them, 8.2% suffered from high blood pressure. In addition, 76.7% manifested pain in the application area. The presence of side effects was associated with the female gender (p < 0.01). Side effects were more prevalent in younger age (37.2 ± 10.7) than older age (41.5 ± 10.8) (p < 0.01). There was no association with the presence of comorbidities (p > 0.05). CONCLUSIONS: The data suggest that pain in the application area is the most frequent side effect among workers in a Mexican hospital who received the Pfizer BioNTech vaccine against COVID-19. In addition, we observed sialorrhea as a side effect in the studied population and this had not previously been reported. The highest number of adverse events occurred between 24 to 72 hours after application.

¿Día o noche? El momento ideal para realizar la colecistectomía / Day or night? The right time to perform cholecystectomy

Introducción. La frecuencia de complicaciones postquirúrgicas de la colecistectomía realizada en la noche es un tema de controversia, siendo que se ha reportado una frecuencia mayor durante el horario nocturno. El objetivo de este estudio fue analizar la presentación de colecistectomía difícil dependiendo de la hora en que se realizó la cirugía, además de otras complicaciones, estancia intrahospitalaria postquirúrgica, reingreso a 30 días y reintervención. Métodos. Se realizó un estudio retrospectivo, observacional, analítico y transversal, comparando la presentación de colecistectomía difícil y su frecuencia en horario diurno (8:00 am a 7:59 pm) y nocturno (8:00 pm a 7:59 am), además de seroma, absceso, hematoma, fuga biliar, biloma, estancia intrahospitalaria postquirúrgica, reingreso a 30 días y reintervención. Resultados. Se incluyeron en el estudio 228 pacientes, 117 operados durante el día (52 %) y 111 durante la noche (48 %). La colecistectomía difícil se presentó 26 % vs 34 % de los casos intervenidos en el día y la noche, respectivamente. La complicación más frecuente fue seroma (14 %). La estancia hospitalaria media fue de 2,7 días en cirugías diurnas y de 2,5 en cirugías nocturnas; hubo 3 % de reintervenciones y 6 %, respectivamente. También hubo 2 % de reingresos a los 30 días entre los pacientes operados en el día y 3 % entre los operados en la noche. Conclusiones. La frecuencia de colecistectomía difícil y las complicaciones, la estancia intrahospitalaria postquirúrgica, el reingreso a 30 días y la necesidad de reintervención, no tuvieron diferencias significativas respecto al horario de la cirugía.

Introduction. The frequency of post-surgical complications of cholecystectomy performed overnight is a matter of controversy, and a higher rate has been reported during the night shift. The objective of this study was to analyze the presentation of difficult cholecystectomy depending on the time the surgery was performed, in addition to other complications, postoperative hospital stay, 30-day readmission, and reintervention. Methods. A retrospective, observational, analytical and cross-sectional study was carried out, comparing the presentation of difficult cholecystectomy and its frequency during daytime (8:00 am to 7:59 pm) and at night (8:00 pm to 7:59 am), in addition of seroma, abscess, bile leak, biloma, hematoma, post-surgical hospital stay, 30-day readmission, and reintervention.Results. A total of 228 patients were included in the study, 117 patients operated during the day (52%), and 111 at night (48%). Difficult cholecystectomy occurred in 26% vs. 34% of the cases operated on during the day and at night, respectively. The most frequent complication was seroma (14%). The mean hospital stay was 2.7 days in day surgeries and 2.5 in night surgeries; there were also 2% readmission at 30 days among patients operated during the day and 3% among those operated on at night. Conclusions. The frequency of difficult cholecystectomy and complications, postoperative hospital stay, 30-day readmission, and the need of reintervention, did not have significant differences with respect to the time of surgery.

Whole lesion histogram analysis of apparent diffusion coefficient predicts therapy response in locally advanced rectal cancer.

BACKGROUND: Whole-tumor apparent diffusion coefficient (ADC) histogram analysis is relevant to predicting the neoadjuvant chemoradiation therapy (nCRT) response in patients with locally advanced rectal cancer (LARC). AIM: To evaluate the performance of ADC histogram-derived parameters for predicting the outcomes of patients with LARC. METHODS: This is a single-center, retrospective study, which included 48 patients with LARC. All patients underwent a pre-treatment magnetic resonance imaging (MRI) scan for primary tumor staging and a second restaging MRI for response evaluation. The sample was distributed as follows: 18 responder patients (R) and 30 non-responders (non-R). Eight parameters derived from the whole-lesion histogram analysis (ADCmean, skewness, kurtosis, and ADC10th, 25th, 50th, 75th, 90th percentiles), as well as the ADCmean from the hot spot region of interest (ROI), were calculated for each patient before and after treatment. Then all data were compared between R and non-R using the Mann-Whitney U test. Two measures of diagnostic accuracy were applied: the receiver operating characteristic curve and the diagnostic odds ratio (DOR). We also reported intra- and interobserver variability by calculating the intraclass correlation coefficient (ICC). RESULTS: Post-nCRT kurtosis, as well as post-nCRT skewness, were significantly lower in R than in non-R (both P < 0.001, respectively). We also found that, after treatment, R had a larger loss of both kurtosis and skewness than non-R (∆%kurtosis and ∆skewness, P < 0.001). Other parameters that demonstrated changes between groups were post-nCRT ADC10th, ∆%ADC10th, ∆%ADCmean, and ROI ∆%ADCmean. However, the best diagnostic performance was achieved by ∆%kurtosis at a threshold of 11.85% (Area under the receiver operating characteristic curve [AUC] = 0.991, DOR = 376), followed by post-nCRT kurtosis = 0.78 × 10-3 mm2/s (AUC = 0.985, DOR = 375.3), ∆skewness = 0.16 (AUC = 0.885, DOR = 192.2) and post-nCRT skewness = 1.59 × 10-3 mm2/s (AUC = 0.815, DOR = 168.6). Finally, intraclass correlation coefficient analysis showed excellent intraobserver and interobserver agreement, ensuring the implementation of histogram analysis into routine clinical practice. CONCLUSION: Whole-tumor ADC histogram parameters, particularly kurtosis and skewness, are relevant biomarkers for predicting the nCRT response in LARC. Both parameters appear to be more reliable than ADCmean from one-slice ROI.

El desafío del Hospital Regional de alta especialidad "Dr. Juan Graham Casasús" ante la nueva pandemia de SARS-CoV-2: la ocupación hospitalaria / The challenge of the high speciality Hospital "Dr. Juan Graham Casasus" in the face of the new SARS-CoV-2 pandemic: the bed occupancy

Al inicio de la pandemia en México, el Hospital Regional de Alta Especialidad "Dr. Juan Graham Casasús" contaba con 156 camas para la atención de pacientes críticos por sintomatología correspondiente a COVID-19, para abordar esto, se incrementó en un 50% la capacidad hospitalaria durante el periodo crítico. En los primeros 6 meses de pandemia se brindó atención a cerca del 60% de la población de la región que requirió atención especializada por COVID-19 pero a pesar de los resultados se concluye que COVID-19 representa un importante desafío en el sureste de México. Sobre la base de los resultados actuales se evidencia la necesidad de integrar la detección del SARS-CoV-2 de manera rutinaria reconociendo una nueva normalidad en un hospital de tercer nivel en Tabasco, México

At the beginning of the pandemic in Mexico, the "Dr. Juan Garaham Casasús" Hospital had 156 beds for the care of critical patients due to symptoms corresponding to COVID-19. To address this, hospital capacity increased by 50% during the critical period. In the first six months of the pandemic, care was provided to about 60% of the population in the region that required specialized care for COVID-19, still despite the results, it concluded that COVID-19 represents a challenge in the southeast of Mexico and based on the current results, it is evident the need to integrate the detection of SARS-CoV-2 routinely, recognizing a new normal in a tertiary hospital in Tabasco, Mexico.

Using FHIR to Support COVID-19 Vaccine Safety Electronic Case Reports in America.

During the COVID-19 pandemic, the Pan American Health Organization (PAHO) promoted several activities to strengthen the countries' emergency response. Vaccines represented a breakthrough in the pandemic evolution, even though they have not been equitably distributed. As most vaccines have received emergency authorizations for their timely delivery, vaccine safety surveillance has been highlighted for detecting early signals of potential adverse events following immunization (AEFI, also known as ESAVI). The objective of this article is to share the different steps, methodologies, and preliminary results of a regional policy to strengthen the ESAVI surveillance system in the Americas, including the adoption of HL7 FHIR for health information exchange between countries and PAHO.

The educational quality of the critical view of safety in videos on youtube® versus specialized platforms: which is better? Critical view of safety in virtual resources.

INTRODUCTION: The surgical education has evolved by adopting the visual platforms as a resource of searching. The videos complement the visual learning of surgical techniques of trainees, residents, and surgeons. YouTube® is the most frequently consulted platform in the surgical field. WebSurg® and GIBLIB® are two recognized medical platforms. The Critical View of Safety (CVS) is the most important and effective method to reduce the risk of bile duct injury (BDI) in laparoscopic cholecystectomy (LC). Reaching a satisfactory CVS is a crucial point. We evaluated the CVS of videos on WebSurg® and GIBLIB®, comparing the results with those of the worldwide most popular video platform. METHODS: We performed a search under the term "Laparoscopic cholecystectomy" on the virtual platforms YouTube®, GIBLIB®, and WebSurg®. Three evaluators reviewed the 77 selected videos using the "Sanford-Strasberg' CVS score." The inferential analysis was performed between two groups: YouTube® and Non-YouTube (GIBLIB® and WebSurg®). The characteristics of each video were analyzed including country of origin, type of profile, number of views, and number of Likes. RESULTS: Satisfactory CVS obtained from each of the platforms was GIBLIB® 40%; WebSurg® 44.4%; YouTube® 27.7%. The comparative analysis of CVS quality and CVS score for the Non-YouTube and YouTube® groups did not show a significant difference (p = 0.142, p = 0.377, respectively). CONCLUSION: The videos on GIBLIB® and WebSurg® offer a higher probability of satisfactory CVS compared to YouTube®. Nevertheless, there is no significant superiority of GIBLIB® and WebSurg® over YouTube®.

[Mental health and human rights: The experience of professionals in training with the use of mechanical restraints in Madrid, Spain]. / Salud mental y derechos humanos: La experiencia de los profesionales en formación en el uso de sujeciones mecánicas en Madrid, España.

Mechanical restraint is a coercive procedure in psychiatry, which despite being permitted in Spain, raises significant ethical conflicts. Several studies argue that non-clinical factors - such as professionals' experiences and contextual influences - may play a more important role than clinical factors (diagnosis or symptoms) in determining how these measures are employed. The aim of this study is to understand how the experiences of mental health professionals in training relate to the use of mechanical restraints in Madrid's mental health network. Qualitative phenomenological research was conducted through focus groups in 2017. Interviews were transcribed for discussion and thematic analysis with Atlas.ti. Descriptive results suggest that these measures generate emotional distress and conflict with their role as caregivers. Our findings shed light on different factors related to their experiences and contexts that are important in understanding the use of mechanical restraint, as well as the contradictions of care in clinical practice.

La sujeción mecánica en psiquiatría es un procedimiento permitido en España que despierta importantes conflictos éticos. Diversos estudios sostienen que su uso depende de factores no clínicos, como las experiencias de los profesionales y las influencias del contexto, más que de factores clínicos (diagnósticos o síntomas). El objetivo del estudio es comprender las experiencias de profesionales de salud mental en formación en relación con el uso de sujeciones en la red de salud mental de Madrid. Es un estudio cualitativo de tipo fenomenológico mediante grupos focales, realizados en 2017. Las entrevistas fueron transcritas para su discusión y análisis temático mediante Atlas.ti. Los resultados descriptivos sugieren que estas medidas producen malestar y conflicto con relación al rol de cuidador y se observan estrategias de adaptación a los mismos. A partir de los hallazgos, se reflexiona acerca de aspectos de sus experiencias y del contexto que influyen en su uso, así como de las contradicciones del cuidado en la práctica clínica.

Features of patients that died for COVID-19 in a hospital in the south of Mexico: A observational cohort study.

BACKGROUND: Due to the wide spread of SARS-CoV2 around the world, the risk of death in individuals with metabolic comorbidities has dangerously increased. Mexico has a high number of infected individuals and deaths by COVID-19 as well as an important burden of metabolic diseases; nevertheless, reports about features of Mexican individuals with COVID-19 are scarce. The aim of this study was to evaluate demographic features, clinical characteristics and the pharmacological treatment of individuals who died by COVID-19 in the south of Mexico. METHODS: We performed an observational study including the information of 185 deceased individuals with confirmed diagnoses of COVID-19. Data were retrieved from medical records. Categorical data were expressed as proportions (%) and numerical data were expressed as mean ± standard deviation. Comorbidities and overlapping symptoms were plotted as Venn diagrams. Drug clusters were plotted as dendrograms. RESULTS: The mean age was 59.53 years. There was a male predominance (60.1%). The mean hospital stay was 4.75 ± 4.43 days. The most frequent symptoms were dyspnea (88.77%), fever (71.42%) and dry cough (64.28%). Present comorbidities included diabetes (60.63%), hypertension (59.57%) and obesity (43.61%). The main drugs used for treating COVID-19 were azithromycin (60.6%), hydroxychloroquine (53.0%) and oseltamivir (27.3%). CONCLUSIONS: Mexican individuals who died of COVID-19 had shorter hospital stays, higher frequency of shortness of breath, and higher prevalence of diabetes than individuals from other countries. Also, there was a high frequency of off-label use of drugs for their treatment.

Salud mental y derechos humanos: La experiencia de los profesionales en formación en el uso de sujeciones mecánicas en Madrid, España / Mental health and human rights: The experience of professionals in training with the use of mechanical restraints in Madrid, Spain

RESUMEN La sujeción mecánica en psiquiatría es un procedimiento permitido en España que despierta importantes conflictos éticos. Diversos estudios sostienen que su uso depende de factores no clínicos, como las experiencias de los profesionales y las influencias del contexto, más que de factores clínicos (diagnósticos o síntomas). El objetivo del estudio es comprender las experiencias de profesionales de salud mental en formación en relación con el uso de sujeciones en la red de salud mental de Madrid. Es un estudio cualitativo de tipo fenomenológico mediante grupos focales, realizados en 2017. Las entrevistas fueron transcritas para su discusión y análisis temático mediante Atlas.ti. Los resultados descriptivos sugieren que estas medidas producen malestar y conflicto con relación al rol de cuidador y se observan estrategias de adaptación a los mismos. A partir de los hallazgos, se reflexiona acerca de aspectos de sus experiencias y del contexto que influyen en su uso, así como de las contradicciones del cuidado en la práctica clínica

ABSTRACT Mechanical restraint is a coercive procedure in psychiatry, which despite being permitted in Spain, raises significant ethical conflicts. Several studies argue that non-clinical factors - such as professionals' experiences and contextual influences - may play a more important role than clinical factors (diagnosis or symptoms) in determining how these measures are employed. The aim of this study is to understand how the experiences of mental health professionals in training relate to the use of mechanical restraints in Madrid's mental health network. Qualitative phenomenological research was conducted through focus groups in 2017. Interviews were transcribed for discussion and thematic analysis with Atlas.ti. Descriptive results suggest that these measures generate emotional distress and conflict with their role as caregivers. Our findings shed light on different factors related to their experiences and contexts that are important in understanding the use of mechanical restraint, as well as the contradictions of care in clinical practice

Assessing 3 Outbreak Detection Algorithms in an Electronic Syndromic Surveillance System in a Resource-Limited Setting.

We evaluated the performance of X-bar chart, exponentially weighted moving average, and C3 cumulative sums aberration detection algorithms for acute diarrheal disease syndromic surveillance at naval sites in Peru during 2007-2011. The 3 algorithms' detection sensitivity was 100%, specificity was 97%-99%, and positive predictive value was 27%-46%.

Importancia del uso adecuado del equipo de protección individual y la implementación de protocolos de seguridad perioperatorios durante la pandemia de COVID-19 / Importance of the Proper use of Personal Protective Equipment and the Implementation of Perioperative Safety Protocols During the COVID-19 Pandemic

RESUMEN El panorama que se presenta en la actualidad es un reto sin precedentes para el manejo de los pacientes quirúrgicos, la toma de decisiones y el empleo de recursos en cuanto a material y equipos de protección en el contexto de la pandemia por COVID-19. Por lo que el presente artículo pretende dar a conocer los lineamientos para el correcto actuar en el quirófano, el uso del equipo de protección individual, las indicaciones de cirugía y el mejor abordaje en el marco de esta situación. El principal objetivo de seguir estas recomendaciones es mitigar el riesgo de contagio y educar al personal de salud médico-quirúrgico para que esté preparado para hacer frente a esta pandemia.

ABSTRACT The current landscape represents an unprecedented challenge in managing surgical patients, decision-making and the use of resources such as protective equipment in the context of the COVID-19 pandemic. Therefore, the objective of this article is to provide guidelines for good conduct in the operating room, the use of personal protective equipment, suggestions for surgeries and the best approach in the context of this situation. The main objective of these recommendations is to mitigate the risk of contagion and to educate medical-surgical health personnel in how to deal with this pandemic.

Multiple glacial refugia and contemporary dispersal shape the genetic structure of an endemic amphibian from the Pyrenees.

Historical factors (colonization scenarios, demographic oscillations) and contemporary processes (population connectivity, current population size) largely contribute to shaping species' present-day genetic diversity and structure. In this study, we use a combination of mitochondrial and nuclear DNA markers to understand the role of Quaternary climatic oscillations and present-day gene flow dynamics in determining the genetic diversity and structure of the newt Calotriton asper (Al. Dugès, 1852), endemic to the Pyrenees. Mitochondrial DNA did not show a clear phylogeographic pattern and presented low levels of variation. In contrast, microsatellites revealed five major genetic lineages with admixture patterns at their boundaries. Approximate Bayesian computation analyses and linear models indicated that the five lineages likely underwent separate evolutionary histories and can be tracked back to distinct glacial refugia. Lineage differentiation started around the Last Glacial Maximum at three focal areas (western, central and eastern Pyrenees) and extended through the end of the Last Glacial Period in the central Pyrenees, where it led to the formation of two more lineages. Our data revealed no evidence of recent dispersal between lineages, whereas borders likely represent zones of secondary contact following expansion from multiple refugia. Finally, we did not find genetic evidence of sex-biased dispersal. This work highlights the importance of integrating past evolutionary processes and present-day gene flow and dispersal dynamics, together with multilocus approaches, to gain insights into what shaped the current genetic attributes of amphibians living in montane habitats.

U.S. Civil Air Show Crashes, 1993 to 2013: Burden, Fatal Risk Factors, and Evaluation of a Risk Index for Aviation Crashes.

This study provides new public health data about U.S. civil air shows. Risk factors for fatalities in civil air show crashes were analyzed. The value of the FIA score in predicting fatal outcomes was evaluated. With the use of the FAA's General Aviation and Air Taxi Survey and the National Transportation Safety Board's data, the incidence of civil air show crashes from 1993 to 2013 was calculated. Fatality risk factors for crashes were analyzed by means of regression methods. The FIA index was validated to predict fatal outcomes by using the factors of fire, instrument conditions, and away-from-airport location, and was evaluated through receiver operating characteristic (ROC) curves. The civil air show crash rate was 31 crashes per 1,000 civil air events. Of the 174 civil air show crashes that occurred during the study period, 91 (52%) involved at least one fatality; on average, 1.1 people died per fatal crash. Fatalities were associated with four major risk factors: fire [adjusted odds ratio (AOR) = 7.1, 95% confidence interval (CI) = 2.4 to 20.6, P < .001], pilot error (AOR = 5.2, 95% CI = 1.8 to 14.5, P = .002), aerobatic flight (AOR = 3.6, 95% CI = 1.6 to 8.2, P = .002), and off-airport location (AOR = 3.4, 95% CI = 1.5 to 7.5, P = .003). The area under the FIA score's ROC curve was 0.71 (95% CI = 0.64 to 0.78). Civil air show crashes were marked by a high risk of fatal outcomes to pilots in aerobatic performances but rare mass casualties. The FIA score was not a valid measurement of fatal risk in civil air show crashes.

Caracterización por Ardrea de microorganismos acidófilos aislados en minas de oro de Marmato, Colombia / Ardrea characterisation of acidophilic micro-organisms isolated from gold mines in Marmato, Colombia

La bio-oxidación de minerales mejora la recuperación de metales valiosos y disminuye el impacto negativo causado por los subproductos de las operaciones mineras, pero las interacciones de los microorganismos involucrados son poco conocidas. Con el objeto de avanzar en el estudio de interacciones microbianas de bacterias acidófilas nativas en cultivos mixtos, en este trabajo se utilizó la siembra en medio sólido doble capa y el análisis de enzimas de restricción del ADN ribosomal amplificado (Ardrea)con las enzimas Eco72I, Eco24I, XcmI y BsaAI para caracterizar cuatro aislados tomados de minas de oro de Marmato, Colombia. Los aislados que oxidan hierro y azufre exhibieron patrones de restricción del gen ARNr 16S compatibles con los reportados para Acidithiobacillus ferrooxidans, aunque uno de ellos mostró una morfología de colonia que no ha sido descrita para esta especie; el aislado que oxida azufre mostró un patrón que coincide con el análisis teórico realizado sobre secuencias para Acidithiobacillus thiooxidans incluidas en bases de datos primarias. La técnica Ardrea permitió diferenciar entre At.ferrooxidans y At.thiooxidans, y verificar si la identidad de los aislados correspondía con sus características fisiológicas y la morfología de sus colonias.

Tratamiento del dolor post-operatorio: Tramadol HCl versus Dipirona Mg / Treatment of postoperatory pain: Tramadol HCl versus Dipirona Mg

Nosotros comparamos la eficacia analgésica de Tramadol HCl (analgésico de acción central) versus Dipirona (AINE: Pirazolona) en el tratamiento del dolor post-operatorio. Evaluamos también los efectos secundarios de cada uno de estos fármacos. Un total de 60 pacientes sometidos a cirugía abdominalpredominantemente, participaron en este estudio prospectivo-simple ciego comparativo. 2 grupos de tratamiento fueron establecidos, 30 pacientes en cada grupo. Los analgésicos fueron usados en forma intramuscular, el dolor fue evaluado usndo la Escala Visual Analógica, fue cuantificado el número de bolos que requirió cada paciente, se registró los efectos colaterales y la necesidad de medicación para éstos; la evaluación de la eficacia fue registrada durante las 24 horas luego de la cirugía. Los resultados muestran que la eficacia analgésica es superior con Tramadol HCl (87.50 por ciento de alivio) que Dipirona Mg (68.75 por ciento de alivio) en el tratamiento del dolor severo. En el alivio del dolor moderado Tramadol HCl también fue superior (83.33 por ciento de alivio) mientras que Dipirona Mg (69.23 por ciento). Se registró efectos colaterales en 16.6 por ciento en el grupo Tramadol HCl, de los cuales 13.33correspondió a náuseas y vómitos, Dipirona presentó 9.9 por ciento de efectos colaterales de los cuales 6.6 por ciento correspondió a náuseas y vómitos. No evaluamos los efectos adicionales de los AINEs del grupo Pirazolonas: Dipirona (Hematológicos). El resultado del estudio confiere la mayor eficacia analgésica de Tramadol HCl sobre Dipirona en pacientes port-operados de cirugía abdominal, constituyendose en una alternativa para el manejo adecuado del dolor en el post-operatorio.

Quiste hidatídico abdominal / Abdominal hydatid disease

El quiste hidatídico de localización abdominal se presenta con frecuencia en nuestro medio. El presente trabajo se realiza para mostrar la experiencia y resultados obtenidos en 55 casos con hidatidosis abdominal intervenidos quirúrgicamente en los servicios de Cirugía General del Hospital Nacional Edgardo Rebagliati Martins del Instituto Peruano de Seguridad Social, entre los años 1983-1989

Diseño del voltimetro digital DVM, de doble pendiente

Contenido: Breve descripccion de los voltimetros electronicos, sistemas analogicos y digitales 2. El voltimetro digital de doble pendiente 3. Diseño del circuito de valor absoluto, diseño de algunos bloques, diseño y conmutacion de la fuente de corriente, diseño del contador para DVM, convertidor AC a DC de respuesta promedio, logica de control 4. Diseño de oscilador generador de pulsos: descripccion de tipos de multivibradores, criterios de estabilidad y respuesta de frecuencia, elementos para almacenamiento de datos Latches 5. Implementacion teorica del voltimetro digital: diagrama circuital completo y detallado del DVM proyectado 6. Costo de equipo: justificacion del material empleado, costo del equipo, fuentes de alimentacion DC reguladas. Detalle circuital de los diferentes componentes utilizaos y simbolos logicos usados.