No abstract

Elephant grass is gaining attention among lignocellulosic materials due to its high growth potential, biomass yield, limited requirement for cultivation land and high rates of carbon dioxide absorption. Here was investigate the effect of pretreatment with different concentrations (5, 10 and 20%, mass acid/mass material) of diluted sulfuric acid on the whole elephant grass plant compared with its leaf and stem fractions. The stem was the most recalcitrant fraction, judging from the high recovery of water insoluble solids (WIS) and lower enzymatic hydrolysis yield, upon acid pretreatment. In enzymatic hydrolysis assays, the glucose yield increased with increasing concentrations of acid, reaching maximum values of 89.20 (leaf), 43.54 (stem) and 76.01% (whole plant). The crystallinity index (CrI) increased in both elephant grass fractions, which correlated with the solubilization of amorphous materials such as hemicellulose. Also, the stem fraction had a slightly higher heating value than the leaf fraction (3958.45 and 3939.49 cal/g, respectively). Scanning electron microscopy (SEM) analysis showed drastic morphological changes in the samples with increasing pretreatment severity, although the stem fraction suffered less structural damage than other materials. Taken together, the results suggest that the separation of elephant grass in different fractions decreases biomass heterogeneity and generates a fraction (leaf) with lower inherent recalcitrance and, thus, higher susceptibility to pretreatment and enzymatic hydrolysis, increasing the efficiency of fermentable sugar release. The results indicate that the leaf fraction of elephant grass has higher potential for use in second-generation ethanol production, while the stem fraction may be more useful for energy co-generation by combustion.

Background: Silver nanoparticles (AgNPs) have been widely applied in research and industrial fields, finding applications in nanomedicine, drug delivery, biomedical devices, electronics, the energy sector, and environmental protection. Patents provide information on the industrial viability of product technologies, and the number of patent documents provides an estimate of the evolution of a specific technological field. Aims: The present work aims to describe the current trends in AgNPs patent applications. In addition, a retrospective study of published patents in Brazil is presented. Methods: Analyses of AgNPs-related patents were conducted using the free platform for patent search Lens® in 2010-2019 and articles published in same period using the Scholar® base. The patent applications and their evolution over time, major depositors and holders, and the main technological areas associated with AgNP applications have been described. Results: China and United States are the major patent applicants for nanotechnologies. The worldwide distribution of publications of journal articles shows that China, India, and the United States are the leading countries in the total number of articles published, in that order. Conclusion: Our study of patent applications and published articles confirmed the growing global increase in new technologies involving NPs and AgNPs, particularly in the biotechnology area, in the fields of medicine and agriculture.

This study aimed to evaluate the antitumor potential and cytotoxicity induction mechanisms of green synthesized AgCl-NPs and Ag/AgCl-NPs through image-based high content analysis method. The antitumor potential of AgCl-NPs and Ag/AgCl-NPs was evaluated in breast cancer BT-474 and MDA-MB-436 cell lines treated with 0-40 μg/mL AgCl-NPs or 0-12.5 μg/mL Ag/AgCl-NPs. Normal human retinal pigment epithelial 1 (RPE-1) cells were used for comparison. The growth rate of the RPE-1 cells treated with AgCl-NPs or Ag/AgCl-NPs was little affected, and no significant changes in cell viability were observed. In these cells, the nanoparticle treatments did not induce lysosomal damage, changes in reactive oxygen species (ROS) production