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Abstract This study aims to compare the performance of three anti-corrosion protection methods and estimate the corrosion rate according to the ASTM G1-03 standard in ASTM A36 steel plates. The applied methodology follows the procedure established in the ASTM G31-21 and ASTM G1-03 standards. While a chemical solution based on the ASTM G44 standards was used for corrosion. The corrosion rate was carried out by calculating the optimal sample size of the number of steel witness plates A36 to be immersed in a 3.5% sodium chloride solution, placed in 4 polypropylene vats, simulating the corrosive environment under conditions containing a pH between 6-7 and a temperature between 25-30ºC. For the first method, a polymeric coating was applied according to the SSPC-PA 1 standard using high-volume solids epoxy paints with a corrosion rate of 0.0502 mm/year. In the second method, cathodic protection was applied by sacrificial anode on the witness plates obtaining a speed of 0.0275 mm/year. The third method used a sacrificial anode by an impressed current in which an external source was used to circulate current between the anode and cathode, resulting in 0.0096 mm/year.

Los objetivos de este trabajo fueron determinar la etiología y la sensibilidad antimicrobiana en la infección del tracto urinario (ITU). Para ello, se analizaron prospectivamente 245 orinas extra e intrahospitalarias del Hospital Universitario San Ignacio de Santafé de Bogotá. Las orinas se estudiaron a través del sedimento, Gram, tira reactiva y cultivo bacteriológico; la susceptibilidad antimicrobiana se realizó por el método de Kirby Bauer. De las 245 orinas se descartaron 45; las 200 orinas restantes fueron cultivadas, resultando 100 positivas y 100 negativas. El agente más frecuentemente aislado fue E. coli (85%), seguido de Proteus sp. (6%). Los microorganismos aislados presentaron una alta sensibilidad a la cefotaxima (100%), norflocacina (98%), netilmicina (98%), amikacina (98%), nitrofurantoína (92%), gentamicina (86%), ácido nalidixico (78%) y una sensibilidad del 57% frente al trimetoprim-sulfametoxasol y el 25% a la ampicilina. Los antimicrobianos eficaces para el tratamiento de la ITU, por su bajo costo y alta actividad sobre los microorganismos encontrados, son: nitrofurantoina, norfloxacina, amikacina, netilmicina, gentamicina y ácido nalidíxico.

La generación dinámica de datos alfanuméricos e imágenes con diferentes formas y tamaños, es una urgencia permanente para cualquier organización, en especial cuando se requiere implementar estrategias de mercado basadas en avisos digitales. Este artículo muestra una alternativa para tales avisos. Para ello presenta el diseño y la construcción de un desplegador de información dinámico, de bajo consumo de potencia, basado en leds activados por microcontrolador. Este dispositivo proyecta instantáneamente, por rotación mecánica, una imagen en perspectiva. Esta sensación surge del principio de persistencia, por el cual una imagen permanece por décimas de segundo en la retina antes de desaparecer por completo, luego de que el cerebro interprete la percepción, codificación, comunicación y decodificación de impulsos eléctricos.

En este artículo se usa la información disponible sobre la prestación del servicio educativo en Bogotá para evaluar el impacto redistributivo de los subsidios mediante el análisis de incidencia sobre el ingreso y el gasto por niveles de estratos y localidades de la ciudad. Los resultados indican que los subsidios educativos y las nuevas políticas del distrito han tenido un fuerte impacto progresivo sobre el ingreso y el gasto de los hogares bogotanos más pobres, que se refleja en una reducción de la pobreza y la desigualdad, sin importar la metodología empleada para calcular el subsidio que se imputa al ingreso del hogar.

En este artículo se presenta un modelo teórico de regulación de precios del sector postal para evaluar la existencia de subsidios cruzados entre segmentos regulados y competitivos. Analiza los incentivos de los agentes para utilizar subsidios cruzados cuando los precios se regulan a través de los precios de Ramsey o de un tope de precios global. Encuentra que los subsidios cruzados restringen y distorsionan la liberalización del sector y es esencial evitarlos en favor de la competencia.

Este ensayo revisa diferentes aproximaciones de la teoría económica para evaluar estados sociales alternativos, a partir de la formulación de una función de bienestar social que admita o niegue comparaciones interpersonales de utilidad. Analiza en especial los puntos de vista de la vieja y la nueva economía del bienestar. Y concluye que con los aportes de Amartya Sen al concepto de bienestar como funcionamiento y al de justicia como capacidad de elegir entre diversos funcionamientos, es posible considerar de manera distinta a los agentes y evaluar opciones alternativas de condiciones de vida.

Background: Cardiovascular diseases are ranked among the leading causes of death in the industrialized countries. This study is aimed at ascertaining the mortality trends by ischemic heart disease (IHD) and cerebrovascular diseases (CVD) in Andalusia within the 1975-2004 period., Method: Based on the official IHD and CVD death statistics and the related populations, the gross rates (GR) and age-adjusted rates (TS) and the Potential Years of Life Lost (PYLL) were calculated. To quantify the trends and their change points, a joinpoint regression analysis was made., Results: The number of IHD deaths for females rose from 2,086 deaths in 1975 to 3,336 in 2004, the TS having dropped from 74.29 to 50.94 deaths/100,000 females, the PYLL having dropped from 173.65 years to 90.56 years/100,000 females. The number of deaths for males rose from 2,854 deaths in 1975 to 4,085 in 2004, the TS having dropped from 147, 67 to 104.96 deaths /100,000 males. The PYLL showed a like behaviour from the first to the last year of the series, showing values of 716.46 and 460.04 years / 100,000 males. For the IHD in females, the number of deaths in absolute numbers dropped from 4,712 to 4,221, the TS having dropped from 166.00 to 62.08 deaths in females, and the PYLL from 338.08 to 87.63 years / 100,000 females. For males, the number of deaths dropped from 3,714 to 2,951, the TS from 206.88 deaths /100,000 males in 1975 to 76.12 /100,000 males in 2004, and the PYLL dropping from 533.12 to 182.38 years / 100,000 males., Conclusions: The trend in mortality due to IHD was not constant either among females or males, although it has always been a downward trend, the drop being statistically significant. The drop in the CVD has been such a major one that both the absolute numbers and the gross rates are lower for the most recent years that the first years in the series studied despite the aging of Andalusias population.

Background: Patients with chronic conditions are commonly readmitted to hospital. A study was designed to improve their medical care. The cost/benefit analysis is presented to evaluate its efficiency., Patients and Methods: Patients attended at the Internal Medicine Department in a hospital area who were readmitted three or more times in a year were included in the study. In a prospective study, patients were attended by means of a specific consultation with upon request care or through telephone care, with the possibility of elective admission. A comparison was made of costs of the new care program with costs of their usual care, and it was correlated with attending results., Results: Patients were followed for 32 months with a 45% decrease in admissions, 50% in visits to the Emergency Department, and 26% in the hospital stay days. The new program involves monthly savings over 5 million pesetas for the attended population., Conclusions: The proposed health care program decreases the attending needs in these patients and costs derived from hospital care. An efficient alternative is shown.

Background and Objective: Patients with chronic conditions are often readmitted to hospital. A study was designed to improve health care to these patients., Patients and Methods: Patients attended at the Internal Medicine Department of a hospital area who were admitted to hospital at least three times in a year were included in the study. Within a prospective study, patients were attended by means of specific consultation with care upon request and telephone care, with the possibility of programmed admission., Results: Patients were followed for 32 months, with a 45% decrease in the admission rate, 50% in visits to the Emergency Department, and 26% in hospital stay days., Conclusions: The proposed care model decrease the attending needs for these patients.

Background: The lysis-centrifugation system (Isolator system) is a technique with excellent results in the recovery of mycobacteria from blood specimens. This system consists mainly of saponin (SAP), polypropylenglycol (PPG), and sodium polianthol sulfonate (SPS). The objective of this work was to determine the effect of SAP, PPG, and SPS on the growth of Mycobacterium avium, M. kansasii, M. tuberculosis, and M. xenopi in fluid culture media MGIT and Septi-Chek AFB., Methods: Two concentrations each of SAP, PPG, and SPS were prepared, and were added in 0.1 ml amounts (alone, in pairs and in combination) to fluid media MGIT and Septi-Chek AFB. Fluid culture media were then in individually inoculated with two different concentrations (10(3) and 10(5) CFU/ml) of each of the four mycobacterial strains used in this study. Culture media were incubated at 37 degrees C and were checked for growth daily., Results: SAP, PPG, and SPS did not inhibit growth of mycobacteria but growth of these strains was indeed retarded (a lengthier time was required for detection of bacterial growth compared with the positive control). Final concentrations of SAP, PPG, and SPS which retarded mycobacterial growth varied, depending upon species, mycobacterial inoculum size, and fluid culture media used., Conclusions: Components included in the lysy-centrifugation system (SAP, PPG, and SPS), either alone or in combination retarded growth of M. avium, M. kansasii, M. tuberculosis, and M. xenopi in 10(3) and 10(5) CFU/ml concentrations in fluid culture media MGIT and Septi-Chek AFB. These results suggest that strategies should be adopted to decrease the concentrations of these three components, present in the sediment of the processed blood by the Isolator System, which eventually are going to be added to fluid media MGIT and Septi-Check AFB.

Background: Decrease in mortality due to cardiovascular diseases during last years seems to be a widespread phenomenon in industrialized countries. This study analyses the evolution of mortality due to cardiovascular diseases in Andalucía, Spain, from 1975 to 1992. The analysis has been carried out for ischemic heart diseases, cerebrovascular diseases and cardiovascular diseases as a whole., Patients and Methods: Data of mortality have been obtained from the Natural Movement of the Population. From these data, both the annual standardized rates for age and sex through the direct method and percentage differences between 1975 and 1992, have been estimated., Results: Decrease in mortality due to cardiovascular diseases for men was of 33.5% between 1975 and 1992, with 13.8% in the ischemic cardiopathy and 46.0% for cerebrovascular diseases. For women, reduction was of 33.8, 29.3 and 42.4% respectively., Conclusions: In Andalucía and for the period analyzed, mortality due to cardiovascular diseases is clearly decreasing. Such a reduction has been produced mainly for the cerebrovascular diseases, and it is remarkable the low percentage of the average decrease due to ischemic heart disease for men during the last years.

We report a patient with systemic vasculitis who developed a Pneumocystis carinii pneumonia whilst he was on steroid n cyclophosphamide treatment. Severe lymphopenia was noted with a CD4 count of 0.023 x10(9)/1 with no evidence of Human Immunodeficiency virus infection. A literature review of recent reports about this particular topic reveals that the development of lymphopenia in patients under immunosuppressor treatment is a fact of a paramount importance. In that sense, a periodic monitorization of both the granulocyte and the lymphocyte count is widely recommended in patients under cytotoxic treatment. A dose adjustment or even suppression of drug administration would be necessary if severe lymphopenia was observed.

Background: To evaluate the catalase test as a screening method in urinary tract infection (UTI) versus sediment, reactive strip and Gram., Methods: Two hundred forty-five's stain urine samples were prospectively analyzed in the Hospital Universitario San Ignacio de Bogotá (Colombia). The culture was used as a reference test for the evaluation of the screening parameters in UTI patients., Results: Of the 245 urine samples 45 were discarded. The remaining 200 urine samples were cultured being 100 positive and 100 negative. The former were analyzed by screening methods. The sensitivity and specificity of the catalase test was 97% and 94%, respectively with a positive predictive value of 94% and negative of 97%. The most frequently isolated microorganism was E. coli (84%), followed by Proteus sp. (6%)., Conclusions: The use of the catalase test in urinary tract infection is a safe, economic and rapid method providing advantages due to its high sensitivity and specificity values, its good correlation with the different parameters evaluated in this study (sediment, strip, Gram's stain), and offers optimum diagnosis in urinary tract infection in developing countries such as Colombia.

Dementia is an infrequent and little known manifestation of giant cell arteritis or temporal arteritis (GCA-TA). The cases of 2 women with histologically proven GCA-TA are presented in which, together with the most classical symptoms, they presented a brusque mental deterioration on initiation of the disease. One patient developed a severe irreversible dementia which coincided with a rapid reduction in the doses of corticoids; while the other patient demonstrated improvement in cognitive function with steroid treatment and control of the disease. Magnetic resonance studies revealed multiple areas of infarction in both hemispheres in the two patients. The importance of treating multi-infarct dementia is underlined in the context of GCA-TA with high doses of corticoids. It is also emphasized that GCA-TA should be considered in the evaluation of older patients with mental alterations.

This is a preliminary report of our initial experience with thromboendarterectomy in the treatment of four patients with chronic major-vessel thromboembolic pulmonary hypertension. Before surgery, these patients all had severe pulmonary hypertension and cor pulmonale as well as significant abnormalities in lung function (mechanics and gas exchange). They were in class III-IV (NYHA). One of our patients died immediately after the procedure as a result of major bleeding. The remaining three surviving patients have shown a remarkable improvement in both, pulmonary hemodynamics and lung function which has been translated in an also significant improvement in their clinical condition. Although there is still a significant risk involved with this procedure, the thromboendarterectomy represents a reasonable and useful therapeutic approach for selected patients with this deadly form of chronic pulmonary hypertension in which other forms of treatment have proved to be unsuccessful.

Shigella, toxigenic Escherichia coli (stable toxin) and rotaviruses were frequently found among 50 children hospitalized with diarrhea studied during one year. These agents were less common among 45 controls without diarrhea, of comparable age and from the same wards as the cases reported. There was a greater frequency of respiratory symptoms in the diarrhea associated with rotaviruses. These were characterized by frequent bowel movements and vomiting and often fever. The bacterial diarrheas showed, in general, a more severe clinical picture than the viral ones. The rotaviruses had a low endemic level during April-October, but their prevalence increased in December and January; in such months these viruses were found in more than 50 per cent of the diarrheal cases.