On the Response to Aging of OPEFB/Acrylic Composites: A Fungal Degradation Perspective.

Biological agents and their metabolic activity produce significant changes over the microstructure and properties of composites reinforced with natural fibers. In the present investigation, oil palm empty fruit bunch (OPEFB) fiber-reinforced acrylic thermoplastic composites were elaborated at three processing temperatures and subjected to water immersion, Prohesion cycle, and continuous salt-fog aging testing. After exposition, microbiological identification was accomplished in terms of fungal colonization. The characterization was complemented by weight loss, mechanical, infrared, and thermogravimetric analysis, as well as scanning electron microscopy. As a result of aging, fungal colonization was observed exclusively after continuous salt fog treatment, particularly by different species of Aspergillus spp. genus. Furthermore, salt spray promoted filamentous fungi growth producing hydrolyzing enzymes capable of degrading the cell walls of OPEFB fibers. In parallel, these fibers swelled due to humidity, which accelerated fungal growth, increased stress, and caused micro-cracks on the surface of composites. This produced the fragility of the composites, increasing Young's modulus, and decreasing both elongation at break and toughness. The infrared spectra showed changes in the intensity and appearance of bands associated with functional groups. Thermogravimetric results confirmed fungal action as the main cause of the deterioration.

Characterization dataset of oil palm empty fruit bunch (OPEFB) fibers - Natural reinforcement/filler for materials development.

Natural fibers used as reinforcements or fillers for materials development greatly affect properties and performance of end-use applications. As a consequence of conditioning processes such as grinding and sieving, average fiber length varies significantly. It is thus necessary to estimate the length as statistical data distribution rather than a single mean value. This approach implies length measurement of a significant number of fibers; however, a very high number of data points requires not only long-time frames but also significative amount of work. To address these issues, this article details a facile methodology to measure the length of a large number of natural fibers of oil palm empty fruit bunch (OPEFB) together with a statistical analysis to verify the correspondence between theoretical distributions and experimental data. Moreover, further information related to spectrophotometric, physico-chemical, mechanical, thermal, and morphological characteristics of OPEFB fibers coming from oil palm cultivation in Ecuador are presented. The data will contribute to comprehensively and rigorously describe the overall effects of natural fiber lengths on material properties.

Water Absorption Behavior of Oil Palm Empty Fruit Bunch (OPEFB) and Oil Palm Kernel Shell (OPKS) as Fillers in Acrylic Thermoplastic Composites.

In recent years, the use of oil palm wastes has been an interesting approach for the development of sustainable polymer matrix composites. Nevertheless, the water absorption behavior of these materials is one of the most critical factors for their performance over time. In this study, the water uptake characteristics of acrylic thermoplastic matrix composites reinforced separately with oil palm empty fruit bunch (OPEFB) and oil palm kernel shell (OPKS) were evaluated through immersion test in distilled water. The specimens of both composites were manufactured using the compression molding technique at three temperatures (80, 100, and 120 °C) using different particle sizes (425−600 and 600−850 µm). The composites, before and after the absorption test, were characterized by means of Fourier transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy. The evaluation was complemented by the application of the Fickian diffusion model. Overall results showed that water absorption capacity decreased at a higher processing temperature and a larger particle size. In particular, it was observed that the type of reinforcement also influenced both water absorption and diffusivity. OPKS/acrylic and OPEFB/acrylic composites reached a maximum absorption of 77 and 86%, with diffusivities of 7.3 × 10−9 and 15.2 × 10−9 m2/min, respectively. Experimental evidence suggested that the absorption mechanism of the composites followed a non-Fickian model (n < 1.0).

[Clinical trial on the effect of buphenine, aminophenazone and diphenylpyraline hydrochloride in treating the common cold in children of 6 to 24 months of age]. / Ensayo clínico sobre el efecto de la bufenina, aminofenazona y el clorhidrato de difenilpiralina en el tratamiento del resfriado común en niños de seis a 24 meses de edad.

INTRODUCTION: Acute respiratory infections are the second leading cause of morbidity in children under 18 years. Several drugs have been used with variable efficacy and safety, trying to reduce the associated symptoms and improve quality of life. OBJECTIVE: To evaluate the efficacy and safety of buphenine, aminophenazone and diphenylpyraline hydrochloride when compared with placebo for the control of symptoms associated with common cold in children 6-24 months of age. MATERIAL AND METHODS: Randomized clinical trial, double blind, placebo controlled, in 100 children < 24 months of any gender, with symptoms associated to common cold. They received the drug under study vs. placebo for seven days. Both groups received acetaminophen. The change on common cold related symptoms were evaluated. Statistic analysis was made with STATA 11.0 for Mac. RESULTS: Fifty-three children were randomized to study drug and forty-seven to placebo. Age of children in each group was similar (12.2 +/- 5.8 months vs. 12.7 +/- 5.8 months, p NS). There were significant differences between groups in relation to rhinorrea and sneezing resolution, with better results in Flumil group and no adverse events observed. CONCLUSIONS: The results in this study indicates that Flumil is a safe and effective drug for control of symptoms present in the common cold in children aged 6-24 months.

Sida y sus sindromes relacionados: experiencia clinico-epidemiologica en un hospital colombiano / Aids and its related syndromes: clinico-epidemiological experience in a colombian hospital

Con el fin de investigar las caracteristicas clinico-epidemiologicas del SIDA en Colombia, establecimos dos grupos de estudio prospectivos: el primero, un estudio clinico, iniciado en enero , 1984 y el segundo un estudio serepidemiologico iniciado en septiembre, 1985. El grupo 1 estuvo compuesto de 25 portadores asintomaticos y 51 pacientes con SIDA o sus sindromes relacionados (15 con SIDA florido, 9 con CRS y 27 con LPG). El grupo II por 294 homosexuales y bisexuales que deseaban una serologia para VIH y que voluntariamente respondiernon un cuestionario sobre practicas sexuales. El estudio clinico (GrupoI), demostro que la infeccion mas frecuente fue neumonia por P. carinii (20%), seguida de enteritis por Criptosporidium (12%), M. avium intracellularae diseminado, meningitis por C. neoformans y herpes anogenital persistente (8%). Sarcoma de Kaposi se presento en 4 pacientes. Hubo un caso de linfoma primario de cerebro y otro de carcinoma nasofaringeo. El descenso del promedio del recuento total CD4 fue altamente significativo en SIDA florido cuando se comparo con LPG y CRS (p 0.0001 y p. 0.05) respectivamente. Igual sucedio con el promedio de la relacion CD4/CD8 en SIDA florido cuando se comparo con LPG (p.0.003). En el grupo II la tasa de seropositividad para VIH fue 21%. Los que informaron un rol anal pasivo (anal predominante o mixto activo-pasivo) tuvieron una seropositividad del 24%, significativamente mas alta que los anal activos (11%) (p=0.02, RR=2.31). En sujetos que tuvieron relacion anal pasiva con turistas extranjeros el riesgo fue tambien...

Receptores de estrogeno en cancer mamario: demostracion inmunohistoquimica con anticuerpos monoclonales / Estrogen receptors in breast cancer: immunhystochemical demostration with onoclonal antibodies

La determinacion de receptores hormonales puede significar una guia util en el uso de la terapia endocrina del cancer mamario, especialmente en casos avanzados con enfermedad recurrente o metastasica. La presencia de la actividad de receptores hormonales, entre ellos los receptores de estrogeno (RE), de progesterona (RPg) y de prolactina, es una condicion necesaria, aunque no absoluta, para la respuesta hormonal del carcinoma mamario. Aproximadamente 2/3 de los carcinomas del del seno son RE (+); las lesiones metastasicas , un pocomenos, y algunas lesiones benignas tambien son RE (+). Entre 50% y 70% de los canceres mamarios RE(+) responden a la terapia endocrina, mientras solo el 5% a 10% de los tumores RE(-) responden a ella. Una detreminacion RE(-) no es contraindicacion absoluta de terapia endocrina. Los canceres ricos en RE exiben tasas superiores de supervivencia y, en general, tienen un pronostico mas favorable. Se presenta el novedoso metodo inmunohistoquimico de determinacion de RE en preperaciones histologicas convencionales con anticuerpos monoclonales, que se realiza por primera vez en nuestro medio.

Patologia de la colangitis esclerosante primaria / Pathology of primary sclerosing cholangitis

Se describen los cambios basicos macro y microscopicos de la Colangitis Esclerosante Primaria. Se hace enfasis en la variabilidad y falta de especificidad del cuadro patologico en los ductos intra y extrahepaticos

Adenomatosis endocrina multiple tipo IIb / Endocrine multiple adenomatosis type IIb

Se revisa el sindrome de Adenomatosis Endocrina Multiple Tipo IIb, el cual esta constituido por carcinoma medular del tiroides, neuromas mucosos multiples, feocromocitoma y un habito marfanoide caracreristico. Este sindrome al igual que el Tipo I y el Tipo IIa son considerados actualmente como apudomas. El diagnostico se hace por las caracteristicas clinicas marfanoides descritas, por la dosificacion de calcitonina y por los hallazgos histopatologicos que muestran carcinoma medular, neuromas y feocromocitoma. El tratamiento es quirurgico y consiste en la tiroidectomia total y en la extirpacion de los feocromocitomas, cuando estos existen. El pronostico es sombrio y los pacientes invariablemente fallecen, considerandose el tratamiento quirurgico como de tipo paliativo; la radioterapia y la quimioterapia no evitan las metastasis ni las recurrencias. Se presenta un caso clinico con este curioso pero letal sindrome