Improved tuberculosis (TB) case detection and cure rates are expected to accelerate the decline in incidence of TB and to reduce TB-associated deaths. Time series analyses of case reports in Peru showed that the per capita TB incidence rate was probably steady before 1991. Case reports increased between 1990 and 1992 as a result of improved case detection. Although diagnostic efforts have continued to increase since 1993, the incidence of new pulmonary TB cases has declined in every department of the country, with a national rate of decline > or =5.8% per year (range, 1.9%-9.7%). This elevated rate of decline suggests that 27% (19%-34%) of cases (158,000) and 70% (63%-77%) of deaths (91,000) among smear-positive patients were averted between 1991 and 2000. This is the first demonstration that a significant number of TB cases can be prevented through intensive short-course chemotherapy in a high-burden country.
During 1999 to 2000, we identified HIV-infected persons with new episodes of tuberculosis (TB) at 10 hospitals in Lima-Peru and a random sample of other Lima residents with TB. Multidrug-resistant (MDR)-TB was documented in 35 (43%) of 81 HIV-positive patients and 38 (3.9%)of 965 patients who were HIV-negative or of unknown HIV status (p < 0.001). HIV-positive patients with MDR-TB were concentrated at three hospitals that treat the greatest numbers of HIV-infected persons with TB. Of patients with TB, those with HIV infection differed from those without known HIV infection in having more frequent prior exposure to clinical services and more frequent previous TB therapy or prophylaxis. However, MDR-TB in HIV-infected patients was not associated with previous TB therapy or prophylaxis. MDR-TB is an ongoing problem in HIV-infected persons receiving care in public hospitals in Lima and Callao; they represent sentinel cases for a potentially larger epidemic of nosocomial MDR-TB.
RESUMENEl proceso de aserrío de encinos se considera una fase importante de su industrialización y de la calidad de la madera generada. Se analiza el control de calidad del proceso de aserrío, el sistema de corte tradicional con el radial y su efecto en los coeficientes de aprovechamiento, en los tiempos de procesamiento y en la proporción de dimensiones en anchos de la madera generada. Se utilizaron trozas de Quercus laurina, Q. candicans y Q. acutifolia, que se procesaron en un aserradero banda de 8 plg de ancho, con sierras tradicionales para pino. La variación del corte (St) fue de 3,93 mm, que se considera alta y refleja una mala calidad del aserrío, la media fue de 25,36 mm y la dimensión óptima de corte de 28,71 mm, la diferencia indica que un porcentaje considerable de las tablas producidas (80 %) no se puede clasificar en el espesor de la categoría de 3/4 plg. Los coeficientes de aserrío del sistema tradicional fueron de 55,83 % y en el radial de 52,31 %. El tiempo de aserrío para procesar 1 000 pies tablas en el sistema tradicional fue de 73 minutos y en el radial de 103 minutos, lo que representa un 41 % más del tradicional. Con el sistema se aserrío radial, se generó una proporción alta (77 %) de tablas angostas (4 plg y 6 plg), y un porcentaje bajo (23 %) de tablas con anchos mayores de 8 plg. Con el aserrío tradicional, las proporciones se invierten significativamente, para los anchos mayores a 8 plg representaron un 88 %.PALABRAS CLAVE: Aserrío, coeficiente de aprovechamiento, control de calidad, dimensión óptima de corte, encinos. ABSTRACTThe saw milling process is considered as an important phase of the industrialization of oaks and of the quality of the sawn lumber. The quality control of the sawing process is analyzed, as well as the traditional sawing pattern with the quarter sawing (flat grain vs vertical grain) and their effect on the lumber yield (lumber recovery factor), on the processing time and on the proportion of width dimensions of lumber. Logs of Quercus laurina, Q. candicans y Q. acutifolia were processed in a 8-in wide band sawmill, with traditional saw machinery for pine, The sawing variation (St) was of 3,93 mm, which is considered high showing the low quality of the sawing system, the obtained mean was 25,36 mm and the optimum sawing dimension was of 28,71 mm. The difference means that a large percentage of boards (80 %) was not able to be graded in the thickness category of ¾ inches. The lumber recovery factor of the traditional system was 55,83 % and in the quarter sawn was 52,31 %. The sawing time to process 1 000 board feet in the traditional system was 73 minutes being of 103 minutes in the radial system, which represented 41 % of the traditional system. With the quarter sawn system, a large proportion (77 %) of narrow boards (4-in and 6-in) and small percentage (23 %) of wider than 8-in boards were generated. With the traditional sawing system, the proportions were significatively reversed, for 8-in or wider an 88 % was achieved.
RESUMENEn este estudio se determinó un tamaño de muestra de 87 trozas para lograr una confiabilidad del 95%, con base en la variación del coeficiente de aserrío de una premuestra de 30 trozas. De la trocería procesada, un 43% se clasificó como de alta calidad, un 26% de clase media y un 31% de baja calidad. Respecto al diámetro, el 89.65% se ubicó en un rango de 30 a 55 cm. Se determinó un coeficiente de aprovechamiento nominal de 51% y una proporción de costeras y recortes de 27% y el porcentaje de aserrín de 22%. La calidad y diámetro de las trozas no influyeron en el coeficiente de aserrío, pero sí se presentó una relación directa entre la calidad de las trozas con la calidad de la madera aserrada, la trocería de 1 a y 2 a , generó un 31.70% y un 19.44% de madera de clase; la trocería de 3ª generó un 33.60% de madera de 3ra; la trocería de 4ª y 5ª un 34.79% y un 29.18% de madera de 4ª y 5a respectivamente. Se determinó un costo de la trocería de $432.00 por m 3 r, un costo de aserrío de $216.68 por m 3 ($510.95/ por mpt). Relacionando los costos de estos dos conceptos con los precios de venta de la madera, se determinó una utilidad de $410.58 por m 3 ($968.16 por mpt).PALABRAS CLAVE: Proceso de aserrío, coeficiente de aprovechamiento, rentabilidad. ABSTRACTIn this study a sample size of 87 logs was determined to achieve a 95% confidence, based on the variation of the lumber recovery of a presample of 37 logs. From the logs sampled, 43% were classified as high quality, 26% as medium and 31% as poor quality. Regarding the diameter, 89.65% were within a range of 30 to 55 cm. A lumber recovery factor of 51% was determined and a proportion of slabs and end trims of 27% and 22% of sawdust. The quality and diameter of the logs did not seem to have any influence on lumber recovery, but a relationship was found between log quality and lumber quality, logs of 1 st and 2 nd class produced 31.70% and 19.44% of quality lumber, logs of 3 rd class generated 33.60% of 3 rd grade lumber, logs of 4 th and 5 th grade produced 34.79% and 29.18% of 4 th and 5 th lumber grade respectively. A log price of $432.00 per m 3 and a processing cost of $510.95 per mbf were determined. Comparing the costs of these two concepts with the price of the lumber, a revenue of $968.18 per mbf was determined.
Objetivo: Determinar la actividad citotóxica de Physalis peruviana en las líneas colo-205 (cáncer de colon) y K562 (leucemia mieloide crónica). Diseño: Estudio experimental. Lugar: Laboratorios del Departamento de Farmacología de la Universidad Nacional Mayor de San Marcos y de la Facultad de Ciencias y Filosofía de la Universidad Peruana Cayetano Heredia. Lima, Perú. Materiales: Líneas colo-205, K562 y 3T3 (fibroblastos normales de ratón), extractos etanólicos de hojas y tallos de P. peruviana, y 5-fluorouracilo (5-FU). Intervenciones: Las líneas colo-205, K562 y 3T3 (fibroblastos normales de ratón) fueron expuestas a extractos etanólicos de hojas y tallos de P. peruviana, y 5-fluorouracilo (5-FU) como control positivo. Principales medidas de resultados: Actividad citotóxica de Physalis peruviana en las líneas colo-205 y K562. Resultados: Los CI50 en μg/mL de P. peruviana en hojas y tallos fueron, respectivamente, 1,93 (r=-0,89 p<0,01) y 0,84 (r=-0,91 p<0,01), para colo-205, 2,42 (r=-0,98 p<0,005) y 2,1 (r=-0,98, p<0,005), para K562, 2,67 (r=-0,98 p<0,005) y 4,59 (r=-0,96 p<0,005), para 3T3. Los CI50 para 5-FU fueron: 3,57 (r=-0,96 p<0,005), 15,95 (r=-0,97 p<0,025) y 0,51 (r=-0,88 p=0,01) para colo- 205, K562 y 3T3, respectivamente. Los índices de selectividad de extractos de hojas, tallos y de 5-FU fueron, respectivamente, 1,38, 5,46, 0,14 para colo-205 y 1,10, 2,18, 0,032, para K562. Conclusiones: Los extractos etanólicos de hojas y tallos de P. peruviana son más citotóxicos que el 5-FU, en las líneas colo-205 y K562. Además, son menos citotóxicos en relación al 5-FU en la línea 3T3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.