Chemical Reports

Giant polymer vesicles consisting of amphiphilic diblock copolymers are helpful as artificial biomembrane models based on many similarities in their size, structure, morphological transformation, membrane permeability, etc.  This paper describes the creation of neuron-like tubule extension employing the polymer vesicles.  The polymerization-induced self-assembly was performed in the presence of micron-sized spherical vesicles consisting of poly(methacrylic acid)-block-poly(methyl methacrylate-random-methacrylic acid), PMAA-b-P(MMA-r-MAA), through the photo nitroxide-mediated controlled/living radical polymerization (photo-NMP) using 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl (MTEMPO) as the mediator.  The photo-NMP of methyl methacrylate (MMA) and methacrylic acid (MAA) was carried out in an aqueous methanol solution (CH₃OH/H₂O = 3/1 v/v) using poly(methacrylic acid) (PMAA) end-capped with MTEMPO and the spherical vesicles of PMAA₁₄₁-b-P(MMA_0.831-r-MAA_0.169)₃₆₈ with an 11.7-mm diameter.  The vesicles projected many processes on their surface during the early stage of the polymerization.  As the polymerization progressed, only one or two of the processes extended to thick tubules, accompanied by the slow growth of thin tubules.  Further progress of the polymerization elongated the thick tubules and caused branching of the tubules.  The tubules had a vesicular structure because cup-like vesicles joined in line were formed during the initial stage of the extension.  The polymerization livingness supported the tubule extension based on a linear increase in the molecular weight of the component copolymer and a negligible change in the molecular weight distribution versus the monomer conversion.  The spherical vesicles were similar to the neurons in the tubule extension for the initial projection, followed by the elongation and branching.  This similarity implies that the neurite extension in the neurons is related to the inherent property of the bilayer membrane.

The objective of this study was to show and crosscheck the seed yield and oil composition of three different seeds growing in different regions of Turkey. Extraction with n-hexane solvent indicated that there were differences in terms of oil yield between the regions. The average oil yield was 33.8% and 33.0% seed-I, 35.7% seed-II (Region-a) and 32.6% seed-III (Region-b) oil yields were obtained. The highest fatty acid content of hemp was found as:  linoleic acid (average 55.24%) followed by oleic acid (average 17.20%) and α-linolenic acid (average 16.02%). Crude ash, total dry matter and crude protein analyzes were also performed. It was observed that the hemp seed oil yield was dependent on the extraction whereas extraction had no influence on the fatty acid content. Comparison of the seed oil yield with the other studies indicated that geographical region as well as the extraction method may affect the seed oil yield.

The present study aims for characterization and classification of five different spent petroleum refinery catalysts followed by metal recovery via bioleaching. The nomenclature given to the different spent catalyst (SC) is SC1, SC2, SC3, SC4 and SC5 collected from an Indian petroleum refinery. All spent catalysts were crushed and ground prior to their characterization by X-Ray Fluorescence for chemical composition followed by X-Ray Diffraction and Scanning Electron Microscopy-Energy Dispersive X-Ray Spectroscopy for their mineralogy. Further, all five spent catalysts were classified based upon their chemical composition and mineralogy. Metal recovery from the spent catalysts was carried out by bioleaching by a mixed microbial consortium of iron and Sulphur oxidizing microorganisms.  Most of the spent catalysts showed very significant metal recovery with respect to Ni, Cu, Cr, Mo, Zn, Sr and Ti. The study provides a possible metal recovery route via bioleaching for further testing and scaling up.

There is a lack of fast and inexpensive analysis methods to study the conformational changes and the degree of denaturation of proteins quantitatively. As such, a novel analytical technique is developed based on the ultraviolet-visible (UV-Vis) absorption spectrum of proteins, and a mathematical modeling of the results. The phenomenon behind this technique is the shift of the absorption peak of amino acid residues of BSA such as tyrosine, phenylalanine, and tryptophan as the protein unfolds and these residues are exposed to the solvent. However, the portion of the peak that is shifted is miniscule and it can be enhanced by using the proposed technique in this paper. As an example, we also show how this technique was applied for evaluating the temperature effects on thermal denaturation of bovine serum albumin (BSA) protein. A degree of denaturation curve as a function of time was obtained at three different temperatures using this technique. The results are reproducible and consistent with those reported in the literature. This technique is especially recommended for analyses where several tests are needed quickly, and the amount of sample is limited. Among the applications, it can be used for evaluation of disinfection through assessing the degree of denaturation for pathogens proteins.