Analysis of the lignocellulosic components of biomass residues for biorefinery opportunities.

The present study aims to identify the renewable resources available in Brazil such as açai seed, coconut husks, coffee husks, rice husks, eucalyptus sawdust, grass, soy peel, bamboo, banana stems and banana stalks. To identify such renewable energy sources, samples were examined for their physical and chemical characteristics using X-ray diffraction (XRD), proximate and ultimate analyses, thermogravimetric analysis (TGA), calorific value determination, near-infrared (NIR) spectroscopy, UV spectroscopy, high-pH anion-exchange chromatography (HPAEC-PAD) and accelerated solvent extraction (ASE). Among the biomasses, açai and coffee exhibited higher total sugar content, 67.70% and 62.55%, respectively. Sawdust exhibited low ash, along with the highest calorific value and lignin content. The highest glucose contents were observed in bamboo (44.65%) and sawdust (38.80%). The maximum yield for the bioproducts levulinic acid (LA), formic acid (FA) and furfural were estimated; açai exhibited the highest yield of LA and FA, while coffee exhibited the best furfural yield. All of these properties indicate that the residues are potential candidates for bioenergy production.

Protoporphyrin fluorescence induced by methyl-ALA in skin healing.

BACKGROUND: Estimation of the time period that precedes an injury is critical in forensic medicine. However, there is no reliable method that can be used to evaluate the oldness of a lesion. The aim of this work is to develop a fluorimetric method that can be used to follow the aging process of lesions by applying methyl-ALA (MAL) on wounds and by quantifying protoporphyrin IX (PPIX) fluorescence during the healing process. We also aim to understand the changes in PPIX fluorescence by establishing a correlation with histological evaluations during the healing process. METHODS: Standardized linear wounds were made on the dorsum of 72 mice, which were divided in control (MAL -) and experimental (MAL +) groups. In vivo fluorescence spectra (FS) were collected from normal and wound skin sites of control and experimental groups, corresponding to four groups of FS spectra: (a) FS of skin wound after MAL (+/+); (b) FS of normal skin after MAL (-/+); (c) FS of skin wound without MAL (+/-) and (d) FS of normal skin without MAL (-/-). Animals were monitored periodically for 3 months and euthanized. Tissue specimens were processed for histological analysis using design-based stereological methods. Serial cross-sections were analyzed to evaluate the organization of the dermis and epidermis, collagen deposition and cellular proliferation. RESULTS: FS of skin wound with MAL (+/+) showed an expressive intensity increase from the beginning of the experiment to the 34th day, with maximum fluorescence being observed on the ≈ 11 th day after wounding. There was preferential PPIX accumulation in healing sites as compared to adjacent normal skin (+/-) in the early stage of healing. Histological findings allowed correlation of the fluorescence increase mainly with cell proliferation. The drastic decrease in the FS intensity observed in the end of the healing process was correlated with the decrease in the proliferation rate as well as with the presence of new extracellular fibrous materials. CONCLUSIONS: In the mice wound-healing model tested here, it was possible to distinguish whether the injury was in early or advanced stages by using PPIX fluorescence induced by MAL. We conclude that this method is a promising approach to evaluate the age of skin wounding and we hope this work will stimulate human studies to allow this technique to become standardized in forensic medicine.