In this study, a new sorbent of chemically-modified activated carbon with L-arginine (AC-Arg) has been produced as solid-phase extraction, to trace Zn(II) and Cd(II) ions in real samples, including soil and water samples, by Flame Atomic Absorption Spectrometry (FAAS). Once the surface coverage value is determined, the surface modification has been investigated and assessed, while having em...

We report on an easy-to-use, successful, and reproducible route to synthesize functionalized graphite oxide (GO) and its conversion to graphene-like materials through chemical or thermal reduction of GO. Graphite oxide containing hydroxyl, epoxy, carbonyl, and carboxyl groups loses mainly hydroxyl and epoxy groups during reduction, whereas carboxyl species remain untouched. The interaction of f...

The presence of residual structure in the unfolded state of the N-terminal SH3 domain of Drosophila drk (drkN SH3 domain) has been investigated using far- and near-UV circular dichroism (CD), fluorescence, and NMR spectroscopy. The unfolded (U(exch)) state of the drkN SH3 domain is significantly populated and exists in equilibrium with the folded (F(exch)) state under non-denaturing conditions ...

Glucose oxidase (GOX; beta-d-glucose:oxygen oxidoreductase) from Aspergillus niger is a dimeric flavoprotein with a molecular mass of 80 kDa/monomer. Thermal denaturation of glucose oxidase has been studied by absorbance, circular dichroism spectroscopy, viscosimetry, and differential scanning calorimetry. Thermal transition of this homodimeric enzyme is irreversible and, surprisingly, independ...

Although a great deal is known about the cellular function of molecular chaperones in general, very little is known about the effect of temperature selection on the function of molecular chaperones in nonmodel organisms. One major unanswered question is whether orthologous variants of a molecular chaperone from differential thermally adapted species vary in their thermal responses. To address t...

Nanocomposites were synthesized from reactive thermally stable montmorillonite and aromatic-aliphatic polyamide obtained from 4-aminophenyl sulfone and sebacoyl chloride. Carbonyl chloride terminal chain ends were generated using 1% extra sebacoyl chloride that could interact chemically with the organoclay. The distribution of clay in the nanocomposites was investigated by XRD, SEM, and TEM. Me...

We used local probe techniques to characterize electron beam ~e-beam! induced changes in thin oxides on silicon. Primary effects of the 1 nm wide, 300 keV e beam included the formation of positive charges trapped in the SiO2 , physical restructuring in the oxide, and deposition of carbonaceous compounds. Charges remained stable in thicker oxides ~460 nm! and appeared as changes in the contact p...

Pigment Red3 was synthesized and chemically treated by sulphonation. The treatment, affected the surface chemistry and the shape of pigments. The effects of reaction time, temperature, Solvent/Pigment ratio and Acid/Pigment ratio were examined on the treated pigment. The investigation of experimental design based on Tauguchi method, was carried out. To assessment of treated particles, UV-visibl...