Acidified,Wet, Silica-Supported Tetrabutylammonium Periodate: A Convenient and Mild Reagent for Conversion of Thioamides to Their Corresponding Amides Under Solvent-Free Conditions

A series of thioamides are transformed to their corresponding oxo analogues in good to excellent yields with acidified, wet, silica-supported tetrabutylammonium periodate under solvent-free conditions.     

Porous shape memory polymers: Design and applications

Porous shape memory polymers (SMPs) exhibit geometric and volumetric shape change when actuated by an external stimulus and can be fabricated as foams, scaffolds, meshes, and other polymeric substrates that possess porous three-dimensional macrostructures. These materials have applications in multiple industries such as textiles, biomedical devices, tissue engineering, and aerospace. This review article examines recent developments in porous SMPs, with a focus on fabrication methods, methods of characterization, modes of actuation, and applications. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1300–1318     

New Coordination Polymers of 1,4-Bis(2″-Hydroxyphenylazomethine) Phenylene

Coordination polymers of 1,4-bis(2′-hydroxyphenylazomethine) phenylene have been prepared with the metal ions Ti(III), Cr(III), Fe(III), Mn(II), Ni(II), and Cu(II). They were characterized by elemental analysis, IR, and electronic spectra. The metal contents in all polymers were found to be consistent with a 1:1 (metal:ligand) stoichiometry. The thermal behavior of these coordination polymers has been studied by thermogravimetric analysis in air up to 750°C, and the data showed that they are thermally stable up to 200°C. Physical properties such as the solubility and viscosity of the polymer complexes were also determined. Electrical conductivity measurements of the synthesized polychelated polymers showed that they are insulators except for the Ni(II) complex which shows a semiconducting character. Mössbauer data clearly establish the 3 + oxidation state for the iron complex polymer.     

Functionalization of short multi-walled carbon nanotubes with creatinine and aromatic aldehydes via microwave and thermal methods and their influence on the MKN45 and MCF7 cancer cells

The chemical functionalization of carboxylated short multi-walled carbon nanotubes (Sh–MWCNT–COOH) by creatinine (Sh–MWCNT–amide) and later modification with aromatic aldehydes for producing 2-amino-5-arylidene-1-methyl-1H–imidazol-4(5H)-one (Sh–MWCNT–imidazols) via thermal and microwave methods have been investigated. All the products were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, elemental analysis, thermogravimetric analysis, derivative thermogravimetric and cellular investigations. These functionalizations have been chosen due to the active sites of CC and carbonyl groups in Sh–MWCNT–imidazols, which might be used as functional materials in the future. MTT assay was used to examine the behavior of cell proliferation after 72 h of cell culture experiments. Cellular investigations were performed for two kinds of cells, human breast and gastric cancer cells. Cellular results showed high toxicity of modified Sh–MWCNTs on the gastric cancer cells compared to breast cells.     

Water Structure Modification by Sugars and Its Consequence on Micellization Behavior of Cetyltrimethylammonium Bromide in Aqueous Solution

Water structure modification by sugars with a wide difference in stereoregular structures ranging from monosaccharide to trisaccharide and its consequence on the micellization behavior of cetyltrimethylammonium bromide (CTAB) in aqueous medium have been investigated. The characteristic variation in water absorption peaks in the presence of d(?)fructose has been studied by near-infrared spectroscopy. The analyses show that the hydrogen bonding capability of d(+)glucose, d(?)fructose, sucrose, trehalose and raffinose is mainly responsible for the variation in water-additive interactions. The critical micelle concentration determined by specific conductivity measurement and aggregation number determined by steady state fluorescence quenching method show significant variations in presence of additives for CTAB in aqueous solution. The sugars interact with the water structure to varying extents owing to differences in hydrogen bonding capability depending on the stereoregularity of the structure. This induces differences in the microenvironment for competition between the hydrophobic interaction and degree of hydration of the hydrophilic group of the surfactant to ultimately influence the micellization behavior in aqueous solution.     

Determination of total arsenic in soil and arsenic-resistant bacteria from selected ground water in Kandal Province, Cambodia

Cambodia has geological environments conducive to generation of high-arsenic groundwater and people are at high risk of chronic arsenic exposure. The aims of this study are to investigate the concentration of total arsenic and to isolate and identify arsenic-resistant bacteria from selected locations in Kandal Province, Cambodia. The INAA technique was used to measure the concentration of total arsenic in soils. The arsenic concentrations in soils were above permissible 5 mg/kg, ranging from 5.34 to 27.81 mg/kg. Bacteria resistant to arsenic from two arsenic-contaminated wells in Preak Russey were isolated by enrichment method in nutrient broth (NB). Colonies isolated from NB was then grown on minimal salt media (MSM) added with arsenic at increasing concentrations of 10, 20, 30, 50, 100 and 250 ppm. Two isolates that can tolerate 750 ppm of arsenic were identified as Enterobacter agglomerans and Acinetobacter lwoffii based on a series of biochemical, physiological and morphological analysis. Optimum growth of both isolates ranged from pH 6.6 to 7.0 and 30–35 °C. E. agglomerans and A. lwoffii were able to remove 66.4 and 64.1 % of arsenic, respectively at the initial concentration of 750 ppm, within 72 h of incubation. Using energy dispersive X-ray technique, the percentage of arsenic absorbed by E. agglomerans and A. lwoffii was 0.09 and 0.15 %, respectively. This study suggested that arsenic-resistant E. agglomerans and A. lwoffii removed arsenic from media due to their ability to absorb arsenic.     

Synthesis of sugar oxime ether surfactants

A straightforward synthesis of a novel class of sugar surfactants is described. The key step is the chemoselective condensation of a hydrophobic alkoxyamine with the resident aldehyde/ketone moiety on a hydrophilic sugar. Neither protection/deprotection of the sugars nor extensive product purification is required. The method allows for the facile adjustment of hydrophobic and hydrophilic domains of the sugar oxime ether surfactant and uses inexpensive, readily accessible, and renewable materials.     

Label-free PSA electrochemical determination by seed-mediated electrochemically-deposited gold nanoparticles on an FTO electrode

Journal of Solid State Electrochemistry - A facile and sensitive approach is introduced to precisely determine trace amounts of prostate specific antigen (PSA) by gold nanostructures deposited on...     

Spectroelectrochemical and electrochromic behavior of poly(methylene blue) and poly(thionine)-modified multi-walled carbon nanotubes

Journal of Solid State Electrochemistry - The increasing efforts devoted to fabricating electrochromic (EC) devices have motivated a lot of studies to develop new EC materials. Herein, we introduce...