Current trends in cacti drying processes and their effects on cellulose and mucilage from two Colombian cactus species.

The effect of temperature and drying technologies on mucilage and cellulose (obtained by the microwave-assisted extraction technique, MAE) from Opuntia ficus-indica (OFI) and Austrocylindropuntia cylindrica (CC) was determined using a conventional oven (CO) and Refractive Window (RW). Mathematical modeling was performed from drying kinetics data using the Lewis, Henderson-Pabis, Page, and Logarithmic models. Activation Energy (Ea) and Diffusivity (D) were also determined. The model with the best fit was the logarithmic one, with a correlation coefficient (R2) greater than 0.99. The obtained activation energies were 22.81 kJ mol-1 for Refractance window (RW) and 31.44 kJ mol-1 using conventional hot air drying (CO) while a diffusivity of 2.9 ∗10-8 m2 s-1 for RW and 1.3∗10-8 m2 s-1 for CO were found as well. According to our results, a greater drying efficiency and a less chemical deterioration of the plant sample are obtained by drying with Refractance window.

Vibrissal paralysis produces increased corticosterone levels and impairment of spatial memory retrieval.

This research was aimed at establishing how the absence of active whisking in rats affects acquisition and recovery of spatial memory. The mystacial vibrissae were irreversibly paralyzed by cutting the facial nerve's mandibular and buccal branches bilaterally in the facial nerve lesion group (N=14); control animals were submitted to sham-surgery (N=15). Sham-operated (N=11) and facial nerve-lesioned (N=10) animals were trained (one session, eight acquisition trials) and tested 24h later in a circular Barnes maze. It was found that facial nerve lesioned-animals adequately acquired the spatial task, but had impaired recovery of it when tested 24h after training as compared to control ones. Plasma corticosterone levels were measured after memory testing in four randomly chosen animals of each trained group and after a single training trial in the maze in additional facial nerve-lesioned (N=4) and sham-operated animals (N=4). Significant differences respecting the elevation of corticosterone concentration after either a single training trial or memory testing indicated that stress response was enhanced in facial nerve-lesioned animals as compared to control ones. Increased corticosterone levels during training and testing might have elicited the observed whisker paralysis-induced spatial memory retrieval impairment.