Combining carvacrol and nisin in biodegradable films for antibacterial packaging applications.

In this work, the feasibility of antibacterial biopolymeric films containing carvacrol (CRV) and a nisin commercial formulation (Nis) for potential food packaging applications was investigated. As polymer matrix, a commercial biodegradable polymer formulation of Mater-Bi (MB) was chosen due to its significant food packaging applications. CRV and Nis were chosen due to their well-established antibacterial properties and their potential synergistic effect. MB/CRV, MB/Nis, and MB/CRV/Nis systems were produced by melt mixing and compression molding. The mechanical properties of the films were evaluated by tensile tests. Differential scanning calorimetry was assessed aiming at investigating the effect of the two compounds and their mixture on the thermal properties of MB. The release profile of CRV and Nis from the MB-based films was evaluated in water at 4 °C by UV-Vis measurements and it was fitted with a power-law model. The antibacterial activity of MB-based films was tested in vitro against Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, and Staphylococcus aureus. The combination of CRV and Nis strongly affected the properties of the MB-based films and ensured higher antibacterial activity if compared to MB/CRV and MB/Nis systems.

Estimación del peso fetal a partir de la medición de la altura uterina / Valuation of the fetal weight a begining of the measurement of the uterine height

Proponer una fórmula que permita al método rural o general, estimar el peso fetal durante el trabajo de parto, a través de la medición de la altura uterina. Seleccionamos 251 pacientes en puerperio normal, estado nutricional adecuado, no fumadoras, fecha de última menstruación conocida y sin dudas, embarazo controlado, feto único, vivo y sin patologías, y parto eutócico no complicado. Hospital Universitario "Dr. Antonio María Pineda" de Barquisimeto. Se obtuvieron dos rectas de regresión lineal, que representan la fórmula propuesta: (A) Y=360,28 + 102,24X, para estimar el peso fetal en ambarazadas en inicio de trabajo de parto, presentación móvil o en I plano, y dilatación menor de 5cm: y (B) Y=1050 + 62,26X, para estimar el peso en embarazadas con presentación en II o III plano, y dilatación igual o mayor 5 cm. El peso fetal estimado con la fórmula mencionada alcanza una precisión de 76,19 por ciento para (A), y del 71,29 por ciento para (B), en el rango de ñ 400 g. Se recomienda la utilización de la fórmula en los centros de atención primaria, como auxiliar para estimar el peso fetal en aquellos casos en que este dato sirva de utilidad para el manejo de la embarazada