JBCS

The photocatalytic reforming of aqueous biomass solutions could be an interesting and innovative route to produce hydrogen in ambient conditions. This process is able to produce hydrogen from renewable energy sources, since it uses solar radiation, raw materials derived from renewable sources such as biomass and water.

The performance of a silica/chitosan hybrid matrix synthesized by sol-gel process was evaluated, using TEOS as a precursor to immobilize enzymes having potential industrial applications. Lipase from enzyme Burkholderia cepacia was chosen as model system. Support (SiO₂-chitosan) and immobilized derivative were characterized with respect to their morphological and biochemical properties.

The water collected in the Anagé Reservoir during the rainy season was classified as S3 and S4, showing very high sodicity values. So it was considered inappropriate for irrigation use.

An interesting chemical behavior for cyclization reactions of a variety of enaminones was described. Selective routes of ring closure were also observed, including direct cyclocondensations, hydrolyses and recombinations, which simultaneously furnished fused bis-(trifluoromethyl)-diazatricycles and 7-aminoquinolines.

The synthesis of symmetric conjugated diyne systems with electron-withdrawing or electron-donating substituents via a palladium-catalyzed detelluration of bis(arylethynyl)tellurides and bis(alkylethynyl) tellurides is described.

Adaptive neuro-fuzzy inference system (ANFIS) has five layers in which layers 0 and 5 represent the descriptors and response, respectively. In this study, ANFIS was employed to predict the partition coeffiction of migrants in food/packaging systems. Forty four systems consisted of 4 food stimulants, 6 migrants and 2 packaging materials were studied.

Map of the study area showing the sampling sites. Red bars account the concentrations of caffeine in the dry season and blue bars represent the concentrations of caffeine in wet season.

d-Penicillamine can dramatically enhance the chemiluminescence(CL) intensities of the novel reaction system: the reaction between Ag(III) complex with luminol. Chemiluminescence spectra: A, Luminol- [Ag(HIO₆)₂]^5- system; B, d-Penicillamine-luminol-[Ag(HIO₆)₂]^5- system.

PVC sensing phase used for extraction of hydrocarbons from water and the absorption spectra obtained for chlorobenzene, trichloroethylene and trichlorobenzene.

The comprehension of pH dependence on charge behavior around surfaces is important in order to control the colloidal stability of dispersion. Around a charged surface in aqueous solution, a diffuse electric double layer takes place, which protects the charge and let all the system uncharged.

Availability of micronutrients (Cu, Fe, Mn and Zn) and organic matter (OM) showing the relationship between their concentrations along the soil profile at an archaeological site Terra Preta 2, district of Juruti, Pará State.

The wastewaters discharge into the Curuperê River from the industrial processing of kaolin at Barcarena City at Pará State (Brazil) caused changes in abiotic conditions also affecting the Dendê River. Environmental impacts from the analyses of the physicochemical characterization and metal levels obtained for surface waters of both rivers were observed.

A new and efficient synthesis of eight 1,3,4-thiadiazolium-2-phenylamine derivatives was realized using microwave and ultrasound irradiation. The target compounds were obtained in good yields and remarkably short times. The cytotoxicity against K562 human leukemia and Daudi lymphoma lines was also evaluated.

Chemotaxonomical studies concerning terpenoid composition of Brazilian amber samples allowed proposing the existence of a resinous paleoflora constituted by conifer families associated to Maracangalha Formation (Recôncavo Basin). The amber occurrence described here is evidence about the distribution of conifers in Brazil during Lower Cretaceous.

The development of a "green" sample preparation procedure for the analysis of inorganic fertilizers based on ultrasound-assisted extraction using an ultrasonic bath is described. Samples were sonicated for 5 min in the presence of 2 mL of 50% (v/v) HNO3 inside glass tubes and satisfactory recovery values were obtained.

Medicinal plants are liable to contain pesticides that may accumulate from agricultural practices. The MSPD is a technique used for the extraction of analytes from solid or viscous samples. The determination of pesticides in medicinal plant is accomplished using gas chromatographic technique.

The graphical abstract shows the morphology of Eugenia neonitida in its habitat and the secretory cavities that accumulate the essential oil and from which it volatilizes. The chemical structures are α-pinene, β-pinene, β-caryophyllene, germacrene D and bicyclogermacrene, the major compounds of both studied species essential oils.

The image of the graphical abstract cartoons the formation of supramolecular complexes produced by the association of poly(ethyleneimine) (PEI) and mixtures of sodium cholate (NaC) and sodium dodecyl sulfate (SDS). The formation of such complexes has been investigated by using a variety of techniques and the results are given in this article.

Differential pulse voltammograms and the corresponding calibration curves obtained for various concentrations of paracetamol and tramadol at a multi-walled carbon nanotube-modified glassy carbon electrode under optimum conditions.

Lipases from different sources were immobilized on ginger starch film or ginger starch/PEO blends. These biocatalytic systems were used in the resolution of (R,S)-phenylethanol with vinylacetate, ethyl acetate, iso-propenyl acetate and acetic anhydride.

We describe herein an approach to the preparation of acyloins and anti-1,2-aminoalcohols based on a Curtius rearrangement coupled with Morita-Baylis-Hillman adducts as substrates. Based on this new approach, the total synthesis of bupropion and spisulosine were accomplished.

Cluster analyses according to general inputs (fecal, terrestrial or marine sources) in the total sterols to the sediments from Paranaguá Estuary. Group I distinguish stations where the proportion of sterols from marine sources is higher while Group II contains the stations where the fecal sterols is extremely low and terrigenous sources are slightly predominant.

Lead iodide nanodisks were prepared using cucurbit[7]uril as a template. These nanoparticles exhibit strong absorption blue-shift as a result of one-dimensional quantum confinement.

The voltammetric methods for propranolol and metabolites were proposed. The differential pulse voltammetry method on glassy carbon electrode could be used for simultaneous determination of mentioned species in urine sample after the enrichment step.

The photocatalytic reforming of aqueous biomass solutions could be an interesting and innovative route to produce hydrogen in ambient conditions. This process is able to produce hydrogen from renewable energy sources, since it uses solar radiation, raw materials derived from renewable sources such as biomass and water.