Observation and Measurement of Ice Morphology in Foods: A Review.

Freezing is an effective technology with which to maintain food quality. However, the formation of ice crystals during this process can cause damage to the cellular structure, leading to food deterioration. A good understanding of the relationship between food microstructure and ice morphology, as well as the ability to effectively measure and control ice crystals, is very useful to achieve high-quality frozen foods. Hence, a brief discussion is presented on the fundamentals/principles of optical microscopic techniques (light microscopy), electronic microscopic techniques (transmission electron microscopy (TEM) and scanning electron microscopy (SEM)), as well as other non-invasive techniques (X-rays, spectroscopy, and magnetic resonance) and their application to measuring ice formation rates and characterizing ice crystals, providing insight into the freezing mechanisms as well as direct monitoring of the entire process. And, in addition, this review compares (the negative and positive aspects of) the use of simple and cheap but destructive technologies (optical microscopy) with detailed microscopic technologies at the micro/nanometer scale but with pretreatments that alter the original sample (SEM and TEM), and non-destructive technologies that do not require sample preparation but which have high acquisition and operational costs. Also included are images and examples which demonstrate how useful an analysis using these techniques can be.

Factor de necrosis tumoral-alfa en el suero de embarazadas normales y preeclámpticas / Tumoral alpha necrosis factor in serum of normal and preeclampic pregnant patient

Se estudiaron las concentraciones séricas del factor de necrosis tumoral-alfa en embarazadas normales de los tres trimestres, en pacientes con preeclampsia y en un grupo testigo de no gestantes, empleando un método de inmunoanálisis enzimático de doble anticuerpo. Se encontró un descenso progresivo y estadísticamente significativo de los niveles de la citocina durante embarazo normal. El grupo con preeclampsia tuvo cifras significativas superiores a las de las embarazadas sanas del tercer trimestre. Los hallazgos apuntan a la necesidad de un descenso en la actividad de estas citocina durante el embarazo normal, sugiere que juega un importante papel en la patogenia de la enfermedad, y plantean la posibilidad de que su cuantificación en suero pueda utilizarse como indicador pronóstico