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Vol 7, No 1 (2017)
- Year: 2017
- Articles: 4
- URL: https://journal-vniispk.ru/2634-8276/issue/view/13567
Article
Physical and chemical characteristics of local dissipative losses in polymethylmethacrylate
Abstract
The review deals with issues related to the theoretical analysis of the main relationship between the chemical structure of polymer and the response of various structural elements of this system to external mechanical effects at different temperatures and frequencies. The analysis is performed using the spectra of internal friction of unplasticized and plasticized polymethylmethacrylate (PMMA) obtained by dynamic methods of external deforming effects in the frequency range from 10–2 to 103 Hz and a temperature range of–50 to +250°C. The regions of local inelasticity are found, and the mechanisms of dissipative losses manifested in different temperature ranges of the spectrum are determined. The physical and chemical characteristics are calculated for each of the identified relaxation processes, and the dependence of these characteristics on molecular weight is found.
64-78
The applications of metal-organic-frameworks in controlled release of drugs
Abstract
The metal-organic-frameworks (MOFs) materials are used as drug carrying substrate in the controlled release of drugs. MOFs are also considered to harness dual or multiple modalities in therapeutic and diagnostic applications. Based on the research that took place over the last 10 years, this article presents an overview on the recent development of the unmodified and modified MOFs used in drug controlled release applications, and describes their biological evaluations such as, biocompatibility, bio-toxicity, cellular uptakes, tissue responses, and intracellular drug delivery. This review illustrates enormous diversities and complexities which cover complex designs and syntheses, types of MOFs being used, drug loadings, types of drug used, drug release kinetics, and ranges of biological evaluations on the MOFs. Perspectives, insights, critical reflections, and future outlook are presented on the area of drug controlled release research using MOFs.
1-22
Electrostatic forces and geometry of organic molecules. Part I. Saturated molecules with tetrahedral fragments
Abstract
A new qualitative approach for analysis of organic molecules geometry, which can be considered as a development of known VSEPR concept is suggested. The core of the approach is electrostatic model, based on the division of the total electron density into an isotropic component which after summation with the nuclear charges turn them into point positive charges (PPCs), and an anisotropic component, tied to the local electron densities (LEDs) of chemical bonds and lone pairs of electrons (LPs). Electrostatic forces (ESFs) affecting the LEDs and PPCs in typical tetrahedral molecular fragments with central carbon atom or heteroatom are considered in detail. The procedure of conditional fixation of PPCs followed by evaluation of perturbing electrostatic forces arising in passing from a particular molecule, or molecular conformation, to another one is applied. Using the existing experimental and ab initio calculation data the model capabilities are demonstrated for typical organic molecules consisting of Н, С, N, O, F, Si, S and Cl atoms.
23-63
Determination of proteins in blood. Part 1: Determination of total protein and albumin
Abstract
The review presents a chronological development of procedures for determining the concentrations of total protein and albumin; total concentration of globulins; concentrations of subfractions, classes, and subclasses of globulins; and total concentrations of globulin subclasses in human blood. A brief overview of these procedures and the results of their comparative tests in medical examination of patients are given. The considered procedures are systematized; their advantages and disadvantages are discussed. It is noted that procedures for measuring the concentration of total protein, albumin, and globulin classes in plasma, serum, and whole blood are widely used in modern clinical diagnostic laboratories when performing routine assays. The concentrations of globulin subclasses and total concentrations of globulin subclasses in blood are mainly determined in biomedical research. Procedures for measuring the concentration of total globulins and globulin subfractions in plasma and serum are of historical importance and now are barely applied in clinical and diagnostic laboratories.
79-124