Influence of cellulose nanofibrils on soft and hard segments of polyurethane/cellulose nanocomposites and effect of humidity on their mechanical properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bacterial Cellulose Nanobiocomposites for Dental Materials Scaffolds

Bacterial cellulose (BC) has become established as a remarkably versatile biomaterial and can be used in a wide variety of scientific applications, especially for medical devices. In this work, the bacterial cellulose fermentation process is modified by the addition of chondroitin sulfate and hyaluronic acid (1% w/w) to the culture medium before the bacteria is inoculated. Besides, biomimetic precipitation of calcium phosphate of biological interest from simulated body fluid on bacterial cellulose was studied. Chondroitin sulfate and hyaluronic acid effects in bacterial cellulose were analyzed using transmission infrared spectroscopy (FTIR), XRD (X-ray diffraction) and scanning electron microscopy (SEM). FTIR analysis showed interaction between bacterial cellulose nanobiocomposites and calcium phosphate. XRD demonstrated amorphous calcium phosphate, carbonated apatite and calcium chloride on bacterial cellulose nanobiocomposites. Monocalcium phosphate monohydrate phase formation [Ca(H2PO4)(2)center dot H2O] are here attested by FTIR, XRD and Ca/P relation.

Novel bioassay for the discovery of inhibitors of the 2-C-Methyl-D-erythritol 4-Phosphate (MEP) and terpenoid pathways leading to carotenoid biosynthesis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nanocomposites based on bacterial cellulose in combination with osteogenic growth peptide for bone repair: cytotoxic, genotoxic and mutagenic evaluations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Improved pretreatments applied to the sugarcane bagasse and release of lignin and hemicellulose from the cellulose-enriched fractions by sulfuric acid hydrolysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

N-Methyl-2-(1-methyl-3-phenyl­prop-2-en-1-yl­idene)hydrazinecarbo­thio­amide

In the title compound, C12H15N3S, the mol­ecule deviates slightly from planarity, with a maximum deviation from the mean plane of the non-H atoms of 0.2756 (6) Å for the S atom and a torsion angle for the N-N-C-N fragment of -7.04 (16)°. In the crystal, mol­ecules are linked by N-H...S hydrogen-bond inter­actions, forming centrosymmetric dimers. Additionally, one weak intra­molecular N-H...N hydrogen-bond inter­action is observed. The crystal packing shows a herringbone arrangement viewed along the c axis.

Mechanical, thermal, and barrier properties of methylcellulose/cellulose nanocrystals nanocomposites

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bioconversion of Cellulose to Hydrogen by dark fermentation

Hydrogen is known as a clean energy resource. The biological production of hydrogen has been attracting attention as an environmentally friendly processs that does not consume fossil fuels. Cellulosic plant and waste materials are potential resources for fermentative hydrogen production. Cellulose is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires the presence of cellulase. The present study aimed to investigate the efficiency of acid pretreatment on ruminal fluid in order to enrich H2 producing bacteria consortia to enhance biohydrogen rate and substrate removal efficiency. In this study, fermentative hydrogen producers were enriched on cellulose (2g/L) in a modificated Del Nery medium (DNM) at 37ºC and initial pH 7.0 using rumen fluid (10% v/v) as inoculum. To increase the hydrogen production it was added cellulose (10mL) to the medium. The gas products (mainly H2 and CO2) was analyzed by gas chromatography (Shimadzu GC 2010) using a thermal conductivity detector. The volatile fatty acids and ethanol were also detected by GC using a flame ionization detector. Cellulose degradation was quantified by using the phenolsulfuric acid method. Analysis showed that the biogas produced from the anaerobic fermentation contained only hydrogen and carbon dioxide, without detectable methane after acid pretreatment test. On DNM the hydrogen production started with 4 h (5,3 x 105 mmol H2/L) of incubation, and the maximum H2 concentration was observed with 34 h (7,1 x 106 mmol H2/L) of incubation. During the process, it was observed a predominance of acetic acid and butyric acid as well as a low production of acetone, ethanol and nbutanol in all experimental phases. Butyrate accounted for more than 77% of total. As a result of the accumulation of volatile fatty acids (VFAs), the pH value in anaerobic digestion system was reduced to 4,0. On microscopy analyses there were observed rods with endospores. The batch anaerobic fermentation assays performed on anaerobic mixed inoculum from rumen fluid demonstrated the feasibility of H2 generation utilizing cellulose as substrate. Based on the results, it can be concluded that the acid treatment was efficient to inhibit the methanogenic archaea cells present in rumen fluid. The rumen fluid cells present a potential route in converting renewable biomass such as cellulose into hydrogen energy.

Synthesis and preliminary characterization of Poly(Propylene)Imine hexadecylamine dendrimer (DAB-Am-16) modified with methyl acrylate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bacterial cellulose-hydroxyapatite composites with osteogenic growth peptide (OGP) or pentapeptide OGP on bone regeneration in critical-size calvarial defect model

This study aimed to evaluate the potential of bacterial cellulose-hydroxyapatite (BC-HA) composites associated with osteogenic growth peptide (OGP) or pentapeptide OGP(10–14) in bone regeneration in critical-size calvarial defects in mice. In this study, the BC-HA, BC-HA-OGP, and BC-HA-OGP(10–14) membranes were analyzed at 3, 7, 15, 30, 60, and 90 days. In each period, the specimens were evaluated by micro-computed tomography (µCT), descriptive histology, gene expression of bone biomarkers by qPCR and VEGFR-2 (vascular endothelial growth factor) quantification by ELISA. Three days post-operative, Runx2, Tnfrsf11b and Bglap bone biomarkers were upregulated mainly by BC-HA OGP and BC-HA OGP(10–14) membranes, suggesting an acceleration of the osteoblast differentiation/activity with the use of these biomaterials. At 60 and 90 days, a high percentage of bone formation was observed by µCT for BC-HA and BC-HA OGP(10–14) membranes. High expression of some bone biomarkers, such as Alpl, Spp1, and Tnfrsf11b, was also observed for the same membranes on days 60 and 90. In conclusion, the BC-HA membrane promoted a better bone formation in critical-size mice calvarial defects. Nevertheless, incorporation of the peptides at the concentration of 10−9 mol L−1 did not improve bone regeneration potential in the long-term.

Aplicação em subdose do haloxyfop-methyl na aveia-preta

One of the major constraints to sustainable of the tillage is the rapid decomposition of dry the matter. One of the mechanisms known to facilitate this process is the interference in pathways of polymers of lignin from tests of application of low doses of herbicide based on the relation that higher the content of the lignin greater the resistance to degradation. With this purpose, the herbicide Verdict * R (haloxyfop-methyl) was used to verify the effect of low doses at the height of the plants, productivity of dry matter and in the metabolism of the lignin in plants of black oat. Preliminary tests in the greenhouse were realized for adjustments ​​to the best low doses to be applied in the definitive experiment in the production area. The results obtained were 24% of increase in productivity in the experiments conducted in greenhouse, from the application of 3.125g of the active ingredient of the haloxyfop-methyl per hectare, in this subdose no changes was observed in growth and content of lignin in plants of black oat. In the field, the concentration of 2.5g i. a. ha-1 of haloxyfop-methyl decreased in 9% the lignification rate without interfering with the height and productivity of the plants, this being favorable to the degradation rate of stubble tillage on outcome

Respostas de populações autógamas de Avena fátua à seleção por baixas doses de diclofop-methyl e glyphosate

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Bacterial cellulose production by Gluconacetobacter xylinus by employing alternative culture media

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Biodegradation evaluation of bacterial cellulose, vegetable cellulose and poly (3-hydroxybutyrate) in soil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)