JBCS

We describe here a simple method to synthesize 4-arylselanylpyrazoles by reaction of α-arylselanyl-1,3-diketones with arylhydrazines using glycerol as solvent at 60 °C under N₂ atmosphere. This is a direct cyclocondensation reaction performed with α-arylselanyl-1,3-diketones and arylhydrazines bearing electron-withdrawing and electron-donating groups affording the corresponding 4-arylselanylpyrazoles in moderate to good yields.

The preparation of pure and Metal-MCM-41 was carried out in water/surfactant/silicate mixtures. The presence of acidic sites favoured the phenol adsorption over Al-MCM-41 at low pH.

Cu-Ni(1:1)/γ-Al₂O₃ catalyst exhibited a maximum glycerol conversion of 71.6% with 92.8% selectivity to 1,2-propanediol at 210 °C and 4.5 MPa hydrogen pressure. The superior performance was attributed to the strong interaction between Cu and Ni, small particle size, and high acidic strength of the catalyst.

An asymmetrical dimer of a kaurane diterpene and monoterpene and four novel diterpenes were isolated from the roots of Croton limae along with other known compounds. The kaurane diterpene exhibited cytotoxic activity against HCT-116, OVCAR-8 and SF-295 cancer cell lines.

Simultaneous quantitation of daidzein and genistein in river water samples using high performance liquid chromatography-diode array detection (HPLC-DAD) and extend multivariate curve resolution-alternative least square (MCR-ALS) calibration.

Immiscible thermoplastic starch/poly(lactic acid) grafted with maleic anhydride (TPS/PLA-g-MA) blend and in detail the hydrogen bond between the TPS matrix and PLA-g-MA domains, due to the use of MA as a compatibilizer.

Palladium nanoparticles supported on polyvinylpyrrolidone grafted silica was prepared. The catalyst exhibited excellent activity in Sonogashira and Suzuki coupling reactions.

Luteinizing hormone (LH) is included on the World Anti-Doping Agency prohibited list. Since LH is an endogenous substance, it is necessary the establishment of the urinary excretion profile of the hormone in Brazilian athletes in order to allow the inference of a possible abuse in sports.

Amino functionalization of nano TiO₂ particles with monoester phosphate through strong covalent interactions.

The newly synthesized thiosemicarbazide derivatives were analyzed by reversed phase high performance liquid chromatography (RP-HPLC) and reversed phase thin layer chromatography (RP-TLC) methods. The log P_HPLC and log P_TLC parameters were determined based on the Organisation for Economic Co-operation and Development (OECD) guidelines.

The use of triacetin, produced from glycerol and acetic acid, as an additive for diesel oil and biodiesel contributes to a reduction in the emission of pollutants into the atmosphere, as shown by the results of a test engine experiment.

One pot synthesis of CuO nanobelt decorated graphene oxide (GO) as well as conversion to CuO nanobelt decorated reduced GO (rGO) and used for electrochemical sensing of glucose has been reported.

This paper describes a new approach for the preconcentration of lead by solvent-assisted dispersive solid phase extraction (SADSPE) from water samples prior to analyzing by flame atomic absorption spectrometry (FAAS).

The observed pyramidalization of phosphorus atoms in resonance structures is due to a spurious error introduced by some density functional theory (DFT) functionals. The optimized geometries of boron and phosphorus (BP-systems), as calculated using electron correlation (e.g., MP2 and CC), exhibit D_3h symmetry (i.e., a flat molecular structure). However, C₁ symmetry can instead be obtained when employing certain exchange-correlation (XC) functionals.

Sodium oleate suppressed the tendency of pitting initiation and reduced the pitting corrosion sensitivity of Al alloy 2024 in 0.1 mol L^-1 NaCl solution. The C₁₇H₃₃COO⁻ groups adsorbed on the surface of Al alloy by chemical adsorption effect, which promoted oxidation of the Al alloy surface.

The study of pyrogenic carbon (PyC) in the archaeological black earth (ABE) profile was based on the O/C atomic ratio, determined by scanning electron microscopy combined with energy dispersive spectroscopy (SEM/EDS).

Tap water samples were submitted to a new microextraction mode for the single-drop microextraction (SDME) procedure. This new approach was applied for the determination of compounds with huge differences in their volatilities in a single assay, with good extraction efficiency.

In this study diphenylboronate was used in basic pH for complexation of analytes, subsequent liquid-liquid extraction with ethyl acetate and its simultaneous analysis by liquid chromatography tandem mass spectrometry (LC-MS/MS).

The atmospheric role in the biogeochemical cycles: atmospheric deposition as an important pathway of nutrients and other compounds to aquatic ecosystems.

A full atomic description of the yeast acetohydroxyacid synthase (AHAS) was obtained by applying computational modeling protocols and molecular dynamics techniques. The refined model proposed will be useful for biosensor developing and other theoretical/experimental studies.

Copper oxide nanofibers synthesized by electrospinning technique and subsequent thermal treatment, were used to modify paraffin-impregnated graphite electrode for a sensitive non-enzymatic glucose detection.

Organic solvents were used to remove lipid phase in the golden flaxseed samples previously to the analyses of Cu, Fe and Zn bound to proteins.

This paper describes the isolation and chemical characterization of a new clerodane-type diterpene, named dinor casearin X, from leaves of Casearia sylvestris, which exhibited cytotoxic activity against HL-60 cells (IC₅₀ 0.51 ± 0.11 mg mL^-1). Additionally, the four known casearins A, B, G and J were also identified.

A method for detecting adulteration in perfumes by ultraviolet (UV) spectroscopy and multivariate analysis is proposed. Classification of perfumes was accomplished with spectroscopic data using chemometrics analysis techniques such as principal component analysis (PCA), soft independent modeling of class analogy (SIMCA) and linear discriminant analysis (LDA).

A new definition of β and fast prediction of phase separation.