Light in evaluation of molecular diffusion in tissues: Discrimination of pathologies.

The evaluation of the diffusion properties of different molecules in tissues is a subject of great interest in various fields, such as dermatology/cosmetology, clinical medicine, implantology and food preservation. In this review, a discussion of recent studies that used kinetic spectroscopy measurements to evaluate such diffusion properties in various tissues is made. By immersing ex vivo tissues in agents or by topical application of those agents in vivo, their diffusion properties can be evaluated by kinetic collimated transmittance or diffuse reflectance spectroscopy. Using this method, recent studies were able to discriminate the diffusion properties of agents between healthy and diseased tissues, especially in the cases of cancer and diabetes mellitus. In the case of cancer, it was also possible to evaluate an increase of 5% in the mobile water content from the healthy to the cancerous colorectal and kidney tissues. Considering the application of some agents to living organisms or food products to protect them from deterioration during low temperature preservation (cryopreservation), and knowing that such agent inclusion may be reversed, some studies in these fields are also discussed. Considering the broadband application of the optical spectroscopy evaluation of the diffusion properties of agents in tissues and the physiological diagnostic data that such method can acquire, further studies concerning the optimization of fruit sweetness or evaluation of poison diffusion in tissues or antidote application for treatment optimization purposes are indicated as future perspectives.

Broadband spectral verification of optical clearing reversibility in lung tissue.

The increase of tissue transparency through sequential optical immersion clearing treatments and treatment reversibility have high interest for clinical applications. To evaluate the clearing reversibility in a broad spectral range and the magnitude of the transparency created by a second treatment, the present study consisted on measuring the spectral collimated transmittance of lung tissues during a sequence of two treatments with electronic cigarette (e-cig) fluid, which was intercalated with an immersion in saline. The saline immersion clearly reverted the clearing effect in the lung tissue in the spectral range between 220 and 1000 nm. By a later application of a second treatment with the e-cig fluid, the magnitude of the optical clearing effect was observed to be about the double as the one observed in the first treatment, showing that the molecules of the optical clearing agent might have converted some bound water into mobile water during the first treatment.

Reuse of the xylanase enzyme in the biobleaching process of the sugarcane bagasse acetosolv pulp.

In this work, pretreatment-enzymatic series of the bagasse-sugarcane pulp and alkaline extraction of enzyme treated pulp were carried out. In the pretreatment an enzyme dose was utilized and acetosolv pulp suspension of 3% (w/v) with different solvents (distilled water, 0.05 mol/L acetate buffer pH 5.5 and 0.05 mol/L phosphate buffer pH 7.25) stirred at 85 rpm for 2 or 4 h. The enzymes used were pulpzyme and cartazyme, both commercial. The accompaniment of the enzymatic activity was carried out through measurement in initial and finish of each enzymatic pretreatment. The xylanase-treated pulps and xylanase-alkaline-extracted pulps were analyzed regarding kappa number and viscosity. Pulpzyme recovery was better in phosphate buffered medium (84, 46, and 23% for first, second, and third enzymatic treatment, respectively) although in aqueous medium reached only 2% for every treatments. However, the improvement of pulp properties was evidenced only in aqueous medium for pulpzyme. Cartazyme recovery was similar for both solvents (water and acetate buffer), reaching values around 19% for first enzymatic treatment and 9% for second one. Nevertheless, the pulp properties increased only in acetate buffered medium.

Racismo, direitos e cidadania / Prejudice, rights and citizenchip

O artigo discute a singularidade do racismo no Brasil como um tipo de discriminação cívica articularmente importante mas que, não obstante, reflete um padrão muito mais abrangente de desrespeito a direitos e de agressão à cidadania. Tendo como foco práticas discriminatórias na vida cotidiana, que seriam estimuladas pela desarticulação entre esfera pública e espaço público no Brasil, o autor identifica o potencial das cotas no plano simbólico como instrumento de combate ao racismo e de afirmação da cidadania.