the purification of biomolecules is a necessary step in many biochemical researches. in this regard, developments of convenient, specific and low cost methods of purification are of particular interest. given the human hemoglobin (hb) affinity toward some charged carbohydrates, interaction of this molecule with human chorionic gonadotropin (hcg) which is a glycoprotein hormone containing sialic...

The effort to understand the mechanism of uncoupling by UCP has devolved into two models - the fatty acid protonophore model and the proton buffering model. Evidence for each hypothesis is summarized and evaluated. We also evaluate the obligatory requirement for fatty acids in UCP1-mediated uncoupling and the question of fatty acid affinity for UCP1. The structural bases of UCP transport functi...

Introduction: The proton beam produced in particle accelerators has an appropriate therapeutic potential. In this research, proton therapy of breast cancer is simulated using the MCNPX code in a MIRD phantom, also the contribution of scattered neutron dose during the proton therapy were calculated for the Heart, Lung and Liver.   Materials and Methods: For si...

The mass spectrum of sulfur (S,) obtained with the ion trap mass spectrometer is compared with that obtained using an E-B spectrometer. Each ion in the spectrum is examined for fragmentation and the vapor shown to consist mostly of the SB oligomer. The chemical ionization spectra using methane, isobutane, ammonia, and water are also examined and an estimate made of the proton affinity of Ss. Us...

1,2,3-Triazoles have come to the forefront as compounds of import in a vast number of applications. The fundamental properties of these species, however, remain largely unknown. Herein, the gas phase properties of 4-phenyl-1,2,3-triazole, benzotriazole, and a series of 1-phenylbenzotriazoles are described. Proton affinity and acidity values are computed and measured. Furthermore, ion-molecule r...

: 1h nmr spectra of a series of enaminones r-co-ch=c(nhch2ph)-r  [1, r=ch3; 2, r=c6h5; 3, r=cf3; 4, r=ch2ch2ch2; 5, r=ch2c(ch3)2ch2], were obtained in the presence of trifluoroacetic acid in cdcl3 or dmso-d6 at 28 °c. steric, solvent, electronic and hydrogen bonding effects on the rates of acid-catalyzed nh proton exchanges were investigated. rate constants were calculated by 1h nmr line shape ...

Introduction: High-energy beams of protons offer significant advantages for the treatment of deepseated local tumors. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum -Bragg peak- near the end of range with a sharp fall-off at the distal edge. Alongside its advantages there are some point that they need to meticul...

In this study, proton conductive composite membranes were produced by using a poly(methylmethacrylate-co-maleic anhydride) (P(MMA-co-MAH)) copolymer and phosphotungstic Acid (PWA) as an additive of the proton conductive agent. P(MMA/MAH) 70/30, 50/50, and 30/70 were synthesized using a free radical polymerization reaction. PWA with a concentration of 2% was added to...

The vesicular acetylcholine transporter (VAChT) mediates ACh storage in synaptic vesicles by exchanging cytoplasmic ACh with vesicular protons. This study sought to determine the stoichiometry of exchange by analysis of ligand binding and transport kinetics. The effects of different pH values inside and outside, external ACh concentrations, and electrical potential gradients on ACh transport by...