125 research outputs found

    Comparative study: drying of yerba mate with wood forest implanted vs wood chip

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    En cumplimiento de la normativa vigente en la provincia de Misiones, las industrias yerbateras han sustituido en sus procesos el uso de leña de bosque nativo por leña de bosque implantado y en menor medida por chip de madera del mismo origen. Cada tipo de combustible tiene una tecnología específica de quemado. El objetivo del presente trabajo fue comparar los dos métodos de secado, para evaluar la incidencia de cada uno sobre los parámetros de calidad del producto final y la eficiencia económica del proceso. Se han encontrado diferencias significativas en las propiedades fisicoquímicas al comparar los métodos utilizados. Se determinó en muestras procesadas con chip menor dispersión de valores de cada variable fisicoquímica. Los costos de producción se redujeron un 29,73% respecto de la leña de bosque implantado. Se determinó que con chip se logra un producto con mejores atributos de calidad y procesos productivos económicamente más eficientesIn compliance with the regulations in force in the province of Misiones, the yerba mate industries have replaced their processes using native wood for firewood planted forest and to a lesser extent chip of wood of the same origin. Each type has a specific fuel burning technology. In compliance with current regulations in the province of Misiones, the yerba mate industries have substituted in their processes the use of native forest firewood by implanted forest firewood and to a lesser extent by wood chip of the same origin. Each type has a specific fuel burning technology. The aim of this study was to compare the two methods of drying, to assess the impact of each on the parameters of product quality and economic efficiency of the process. We found significant differences in physicochemical properties by comparing the methods used. It was determined less dispersion of values of each physicochemical variable in samples processed with chip. Production costs were reduced by 29.73% compared to forest firewood. It was determined that with chip a product of better quality and more efficient economically productive processes is achieved.Fil: Holowaty, Santiago Alexi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Martinez, Mirta C.. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; ArgentinaFil: Brignardello, Adriana E.. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; ArgentinaFil: Schmalko Radichowski, Miguel Eduardo. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentin

    5-En-androstene-3 beta,17 beta-diol inhibits the growth of MCF-7 breast cancer cells when oestrogen receptors are blocked by oestradiol.

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    Adrenal androgens show a dual and apparently opposite effect on the growth of oestrogen-responsive breast cancer: they stimulate growth on their own, but counteract the growth-stimulatory effect of oestrogens. Focusing on the inhibitory action we have studied the effects of 5-en-androstene-3 beta,17 beta-diol (ADIOL) on the growth of oestrogen-responsive MCF-7 breast cancer cells in the presence of oestrogens (oestradiol and diethylstilboestrol), antiestrogens (tamoxifen) and antiandrogens (hydroxyflutamide). The inhibition of oestrogen-stimulated growth, attained with nanomolar concentrations of ADIOL, was not modified by increasing concentrations of diethylstilboestrol up to 100 nM. This inhibition was counteracted by antiandrogens, which were unable to block the ADIOL stimulatory effect in steroid-free medium. On the other hand, in the presence of tamoxifen ADIOL showed an additive antiproliferative activity also in steroid-free medium, rather than the usual stimulatory effect. These results suggest that ADIOL stimulates breast cancer cell growth via oestrogen receptors, but inhibits oestrogen-stimulated growth via androgen receptors

    Role of glucose-6-phosphate dehydrogenase inhibition in the antiproliferative effects of dehydroepiandrosterone on human breast cancer cells.

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    Epidemiological and experimental studies suggest that dehydroepiandrosterone (DHEA) exerts a protective effect against breast cancer. It has been proposed that the non-competitive inhibition of glucose-6-phosphate dehydrogenase (G6PD) contributes to DHEA antitumor action. We evaluated the effects of DHEA on G6PD activity and on the in vitro proliferation of two human breast cancer cell lines, MCF-7 (steroid receptor positive) and MDA-MB-231 (steroid receptor negative), in a serum-free assay. DHEA inhibition of G6PD was only found to occur at concentrations above 10 microM; at these high concentrations, the growth curve was parallel to the enzyme inhibition curve in both cell lines. In contrast, at concentrations in the in vivo breast tissue concentration range, neither cell growth nor enzyme activity was inhibited. The results failed to confirm DHEA's putative anti-tumor action on breast cancer through G6PD inhibition, as the enzyme blockade only becomes apparent at pharmacological concentrations of the steroid

    Employment among Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

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    To date, there are heterogeneous studies related to childhood cancer survivors’ (CCS) employment rates. Given the importance of this topic, we aimed to perform a systematic review and meta-analysis to investigate the prevalence of employment among CCS and to examine its association with socio-demographic and clinical factors. We followed the PRISMA guidelines to search for pertinent articles in relevant electronic databases. Eighty-nine articles comprising 93 cohorts were included. The overall prevalence of employment was 66% (CI: 95% 0.63–0.69). Subgroup meta-analyses showed that lower rates were found for central nervous system tumor survivors (51%, CI: 95% 0.43–0.59), and for CCS treated with cranial-radiotherapy (53%, CI: 95% 0.42–0.64) or haematopoietic stem-cell transplantation (56%, CI: 95% 0.46–0.65). The studies conducted in Asia highlighted employment rates of 47% (CI: 95%, 0.34–0.60). Univariate meta-regressions identified the following socio-demographic factors associated with higher rates of employment: a female gender (p = 0.046), a higher mean age at the time of investigation (p = 0.00), a longer time since diagnosis (p = 0.00), a higher educational level (p = 0.03), and a married status (p = 0.00). In conclusion, this systematic review and meta-analysis provides evidence that two-thirds of CCS are employed worldwide. Identifying vulnerable groups of CCS may allow for the design of multidisciplinary support strategies and interventions to promote employment in this population
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