Ion pairs (also known as salt bridges) of electrostatically interacting cationic and anionic moieties are important for proteins and nucleic acids to perform their function. Although numerous three-dimensional structures show ion pairs at functionally important sites of biological macromolecules and their complexes, the physicochemical properties of the ion pairs are not well understood. Crysta...

Hyaluronic acid-based dermal fillers are the most used materials in cosmiatry, and their clinical implications linked to viscoelastic properties. This study aimed determine rheological behavior of HA products Brazil by changing specific physicochemical characteristics under different test frequencies. Laboratory analyses 0.9 mL samples were performed a TA-Instruments AR-1500ex Rheometer at 25 °...

Objective(s)Bioelectrical impedance is the measure of impedance of the body. Impedance consists of electric resistance and reactance. Phase angle (PA) is the tan value of the ratio of reactance versus electric resistance. PA depends on cell membrane integrity and on body cell mass. There exists a correlation between PA values and body cell mass.The objective of this study was to compare the PA ...

We extend linear and nonlinear approximations for electromagnetic fields to a medium with inhomogeneous distribution of both electrical and magnetic material properties. These approximations are presented in the form of tensor integrals over a domain with anomalous pa­ rameters . The developed approximations combine the linear and nonlinear estimations depending on the ratio of complex conducti...

Background: DNA immunization with plasmid DNA encoding bacterial, viral, parasitic and tumor antigens has been reported to trigger protective immunity. Objective: To evaluate the use of a DNA immunization strategy for protection against anthrax, a plasmid was constructed. Methods: The partialsequence of protective antigen of Bacillus anthracis, amino acids 175-764, as a potent immunogenic targe...

The quality of veterinary vaccines is monitored by physicochemical, microbiological and biological tests. Two of the most important physicochemical parameters are viscosity and density, which are determined in the three different types of matrices: emulsions, suspensions and solvents. Viscosity, known as internal friction or viscose medium, is a feature of fluids and plastic solids characterize...

Problem statement: Since the earliest publication on the technique, Reversed-Flow Gas Chromatography (RF-GC) has been used to determine physicochemical properties by measuring the value of one in the presence of another. The method is precise, accurate and simple compared to other conventional techniques. Approach: The experimental setup consists of a small modification of a commercial gas chro...

We have developed a modular pair of laboratory experiments for use both in undergraduate physical chemistry and biochemistry. Both laboratories examine the thermodynamics of the binding of a small molecule, eosin, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In both experiments students measure fluorescence q...

Physical chemistry describes systems in terms of their energy and their boundary conditions. Quantitative knowledge of the future state of a system can be derived from a set of differential equations, relating to the functions defining that system, that provide reasonable estimates of its behavior. This approach, howe v e r, implies first the need to leave aside the individual characteristics o...