Measuring vitamins and minerals in dietary supplements for nutrition studies in the USA

This article illustrates the importance of having analytical data on the vitamin and mineral contents of dietary supplements in nutrition studies, and describes efforts to develop an analytically validated dietary supplement ingredient database (DSID) by a consortium of federal agencies in the USA. Preliminary studies of multivitamin mineral supplements marketed in the USA that were analyzed as candidates for the DSID are summarized. Challenges are summarized, possible future directions are outlined, and some related programs at the Office of Dietary Supplements, National Institutes of Health are described. The DSID should be helpful to researchers in assessing relationships between intakes of vitamins and minerals and health outcomes.     

Theoretical and Experimental Study on the Adsorption and Desorption of Methane by Granular Activated Carbon at 25 ℃

A theoretical and experimental study was conducted to accurately determine the amount of adsorption and desorption of methane by various Granular Activated Carbon(GAC)under different physical conditions.To carry out the experiments,the volumetric method was used up to 500 psia at constant temperature of 25℃.In these experiments,adsorption as well as desorption capacities of four different GAC in the adsorption of methane,the major constituent of natural gas,at various equilibrium pressures and a constant temperature were studied.Also,various adsorption isotherm models were used to model the experimental data collected from the experiments.The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported.The results shows that the physical characteristics of activated carbons such as BET surface area,micropore volume,packing density,and pore size distribution play an important role in the amount of methane to be adsorbed and desorbed.     

Decorations of graphene oxide with cisplatin toward investigation of fluorescence quencher on regulatory sequence of BRCA1 and BRCA2

Journal of the Iranian Chemical Society - Herein, we investigated the interaction of cisplatin loaded on GO (GO@CDDP) with two regulatory sequences, BRCA1 and BRCA2, synthesized from ssDNA based on...     

Rapid and green synthesis of 4H-benzo[b]pyrans using triethanolamine as an efficient homogeneous catalyst under ambient conditions

Research on Chemical Intermediates - 4H-benzo[b]pyrans were obtained rapidly in high yields using triethanolamine as an efficient, eco-friendly and low-cost basic catalyst. One-pot three-component...     

Cooperative effects in phospholipid monolayers induced by a peptide from HIV-1 capsid protein

The study of interactions between biological molecules and model membranes is essential for the understanding of a number of physiological mechanisms involved in viral infections and dissemination. In this paper, the analysis of the interaction between a peptide from the p24 protein of Human Immunodeficiency Virus type 1 (HIV-1) and a phospholipid monolayer has pointed to a cooperative response in which very small amounts of peptide p24-1 (e.g. 0.05 mol%) can lead to measurable effects. Monolayer surface pressure and surface potential isotherms were affected for peptide concentrations as low as 0.05 mol%, with saturation at 0.5 mol%. The expansion effect from p24-1 is confirmed by changes in morphology of the monolayers using Brewster angle microscopy. Even though p24-1 is disordered in aqueous solutions, the interaction with dipalmitoyl phosphatidylcholine (DPPC) causes it to adopt an alpha-helix structure, as shown by circular dichroism (CD) data for multilamellar vesicles (MLV). The expansion of the phospholipid monolayer in a cooperative way may imply that p24-1 has potential antiviral activity, by participating in the cell rupture, with no need of specific receptors in the membrane.     

Nuclear spin relaxation study of aqueous raffinose solution in the presence of a gadolinium contrast agent

Paramagnetic enhancement of nuclear spin-lattice relaxation rates (PREs) was measured in aqueous solution of the trisaccharide raffinose in the presence of a gadolinium(III) complex, GdDTPA-BMA, used as a magnetic resonance imaging contrast agent. The relaxation enhancement of aqueous protons was measured over a broad range of magnetic fields, using field-cycling apparatus in addition to conventional spectrometers. The nuclear magnetic relaxation dispersion profile thus obtained was interpreted with a recently developed model, allowing for both inner- and outer-sphere relaxation. The relaxation enhancement for the carbon-13 nuclei in raffinose was studied under high-resolution conditions at three magnetic fields, whereas the sugar proton PRE was measured at two fields. The PRE of the sugar nuclei could be interpreted in a consistent way, assuming that it was caused by the outer-sphere mechanism. The electron spin relaxation was found to be a less important source of modulation of the electron-nuclear dipole-dipole interaction than the mutual translational diffusion.     

A design of fluorescent probes for superoxide based on a nonredox mechanism

Fluorometric detection of O2-* is performed based on desulfonylation of 3 to the corresponding fluoresceins 4 through nucleophilic substitution, and this fluorescing process is quite specific toward O2-* over H2O2, t-BuOOH, NaOCl, 1O2, HO*, NO*, and ONOO-. Furthermore, effects of glutathione, cytochrome P450 reductase/NADPH, and diaphorase/NADH are relatively small on the fluorescing process of probe 3 with X = Y = F, which is useful to detect O2-* released from neutrophils stimulated by phorbol myristate acetate with satisfactory sensitivity.     

Gas chromatographic technique for determination of Irgafos 168 in polyolefin samples after conversion to the related phenolic compound by saponification

A gas chromatographic technique is reported for the determination of a secondary antioxidant, Irgafos 168, in polymeric samples. Irgafos 168 [tris(2,4-di-tert-butyl phenyl)phosphite] is extracted by dissolution/precipitation, saponified to 2,4-di-tert-butyl phenol by refluxing in the presence of methanolic potassium hydroxide, and determined by gas chromatography-flame ionization detection. The method’s repeatability is good, and the relative standard deviation is 7.5% (between runs) and 15.5% (between days). This method was applied to the determination of Irgafos 168 in commercial polymers, and the obtained results were in relatively good agreement with those obtained by the previously reported spectrophotometric method. Correspondence: Mir Ali Farajzadeh, Department of Chemistry, Faculty of Science, Urmia University, Urmia, Iran     

Nanotechnology in the public eye: the case of Iran,as a developing country

Using survey data, public awareness of and attitudes toward nanotechnology are examined in Iran (N = 759). Iran is a developing country with a national nanotechnology action plan for a ten year period starting from 2003 and has been active in the field of research and development of nanotechnology meanwhile. First, the results show that majority of people are still not familiar with nanotechnology and perceived risks posed by this technology are not considered to be a lot and most people feel its benefits outweigh the risks. The emotions toward this technology are of a hopeful and positive nature and this technology is looked upon favorably in Iran. In particular, our results reveals that although the level of trust is high specially in scientists to communicate the risks with the public, there are a great number who just have some trust not quite a lot of it. Knowing that it is a hard and time-consuming effort to manage a nation’s view on nanotechnology, extensive research as well as collaboration with other countries is needed to effectively communicate the risks in time.