Instrumental Methods for Cage Occupancy Estimation of Gas Hydrate

Studies revealed that gas hydrate cages, especially small cages, are incompletely filled with guest gas molecules, primarily associated with pressure and gas composition. The ratio of hydrate cages occupied by guest molecules, defined as cage occupancy, is a critical parameter to estimate the resource amount of a natural gas hydrate reservoir and evaluate the storage capacity of methane or hydrogen hydrate as an energy storage medium and carbon dioxide hydrate as a carbon sequestration matrix. As the result, methods have been developed to investigate the cage occupancy of gas hydrate. In this review, several instrument methods widely applied for gas hydrate analysis are introduced, including Raman, NMR, XRD, neutron diffraction, and the approaches to estimate cage occupancy are summarized.

MODERN INSTRUMENTAL METHODS FOR QUALITATIVE AND QUANTITATIVE ANALYSIS OF LAPATINIB IN BIOLOGICAL FLUIDS AND DOSAGE FORMS (REVIEW)

Lapatinib is a small molecule, a heterocyclic quinazoline derivative. The drug is used for targeted therapy of patients with breast cancer, in which there is overexpression of the human epidermal growth factor receptors (HER/ErbB). This review is devoted to studying modern instrumental methods of qualitative and quantitative analysis of lapatinib, which can be used both for quality control and standardization (of bulk pharmaceuticals and dosage forms) and pharmacokinetics studies of a drug. Reverse-phase high-performance liquid chromatography (RP-HPLC) is mainly used to identify lapatinib in tablets. Depending on the purpose of the study, various detectors are used (ultraviolet or diode-matrix detector), which makes it possible to determine not only the native compound but also the products of its degradation. Definition of lapatinib in the presence of degraded products is necessary for forced degradation studies to determine drug stability. When a drug is being developed, it is important to define and understand its pharmacokinetics. For such studies, high-performance liquid chromatography (HPLC) coupled with the mass selective detector is often used. It allows determining lapatinib in biological fluids. However, these methods are not applicable for identifying the drug directly in dosage forms and require further development and validation.

Mucilage of Coccinia grandis as an Efficient Natural Polymer-Based Pharmaceutical Excipient

Natural eco-friendly materials are recently employed in products to replace synthetic materials due to their superior benefits in preserving the environment. The herb Coccinia grandis is widely distributed in continents like Asia and Africa and used traditionally to treat fever, leprosy, asthma, jaundice, and bronchitis. Mucilage of Coccinia grandis was accordingly extracted, isolated by a maceration technique, and precipitated. The mucilage was evaluated for its physicochemical, binding, and disintegrant properties in tablets using paracetamol as a model drug. The crucial physicochemical properties such as flow properties, solubility, swelling index, loss on drying, viscosity, pH, microbial load, cytotoxicity was evaluated and the compatibility was analyzed using sophisticated instrumental methods (TGA, DTA, DSC, and FTIR). The binding properties of the mucilage was used at three different concentrations and compared with starch and PVP as examples of standard binders. The disintegrant properties of mucilage were used at two different concentrations and compared with standard disintegrants MCCP, SSG, and CCS. The tablets were punched and evaluated for their hardness, friability, assay, disintegration time, in vitro dissolution profiles. In vitro cytotoxicity studies of the mucilage were performed in a human embryonic kidney (HEK) cell line. The outcome of the study indicated that the mucilage had good performance compared with starch and PVP. Further, the mucilage acts as a better disintegrant than MCCP, SSG and CCS for paracetamol tablets. Use of a concentration of 3% or less demonstrated the ability of the mucilage to act as a super disintegrating agent and showed faster disintegration and dissolution, which makes it as an attractive, promising disintegrant in formulating solid dosage forms to improve the therapeutic efficacy and patient compliance. Moreover, the in vitro cytotoxicity evaluation results demonstrated that the mucilage is non-cytotoxic to human cells and is safe.

Public Control of Radiation Hazardous Facilities: Experience and Results

Independent public control of nuclear facilities is aimed at raising awareness of the general public about the effectiveness of measures to protect the environment from the radiation effects. The experience and the result of interaction between specialists of the Academy of Sciences and a higher school in organizing and conducting public control by instrumental methods of the territories for the location of radiation-hazardous facilities: uranium mining sites by underground leaching, the area of the Belarusian nuclear power plant in the pre-operational period, the area of the floating nuclear power plant "Akademik Lomonosov" and the publicly accessible territory of control area of the Mayak Production Association. Such a pooling of efforts allows for the formation of new ways of obtaining reliable information for any interested public. The results of special studies characterizing the radioecological situation in the surveyed territories are presented.

A Review on the Structure and Anti-Diabetic (Type 2) Functions of β-Glucans

Type 2 diabetes, a long-term chronic metabolic disease, causes severe and increasing economic and health problems globally. There is growing evidence that β-glucans can function as bioactive macromolecules that help control type 2 diabetes with minimal side effects. However, conflicting conclusions about the antidiabetic activities of β-glucans have been published, potentially resulting from incomplete understanding of their precise structural characteristics. This review aims to increase clarity on the structure–function relationships of β-glucans in treating type 2 diabetes by examining detailed structural and conformational features of naturally derived β-glucans, as well as both chemical and instrumental methods used in their characterization, and their underlying anti-diabetic mechanisms. This may help to uncover additional structure and function relationships and to expand applications of β-glucans.

Assessment of risk factors and prediction of premature ovarian failure

The problem of premature ovarian failure (POF) is currently in the spotlight of obstetricians and gynecologists worldwide. Early diagnosis of this pathology is necessary to prevent the development of serious pathological conditions. The systematization of modern ideas about laboratory and instrumental methods for POF diagnosing, assessing diagnostic value of parameters such as follicle stimulating hormone, anti-Mullerian hormone as well as the count of antral ovarian follicles, intraovarian blood flow and ovarian volume using ultrasound techniques, which can then be used as prognostic criteria for POF comprise a very important modality. Based on the findings obtained, early detection may lead to proposing new prognostic strategies.

Comparative Study of Sensory Attributes of Leafy Green Vegetables Grown Under Organic and Conventional Management

This study was carried out to compare the sensory qualities of leafy green vegetables (collard, kale, lettuce and swiss chard) grown under organic and conventional production systems. Four leafy greens were produced on an organically and conventionally managed research farm of Tennessee State University, Nashville, TN in Spring 2019 and 2020. Crops in a conventional field were grown in the open field, whereas in organic field crops were grown in the open and under three different row covers (agribon cloth, insect net and plastic). Row covers in organic systems were used to protect crops from insect damage. Plant samples were collected from all the treatments and evaluated for sensory qualities including color, texture, taste, odor and flavor following two approaches i.e., instrumental and via consumer panel perception. Consumer panel perception results showed minor differences in the sensory qualities between organic and inorganically produced leafy greens. Instrumental methods showed no differences in color parameters of kale, lettuce and swiss chard grown under organic and conventional production systems. In collard, the lightness (L*), b* (yellow-blue axis), brightness (Y) and chroma (C) values were higher in conventional, while hue angle was higher in organic (open). There were no differences in instrumental textural values of organically and conventionally grown leafy greens. Among row covers, the textural value of collard and kale was higher in open relative to row covers. The content of main quality contributors 1-Hexanol was higher in conventionally grown collard compared to organic (open). Aldehyde compound was higher in organically grown kale and trans-hex-2-enyl-acetate (Ester) compound was higher in conventionally grown kale. Monoterpenes were higher in organic lettuce and ketones were higher in conventionally grown lettuce. Overall, there were not many differences in the sensory qualities of leafy greens grown under organic and conventional production systems. Further comparative studies between organic and conventional systems on sensory qualities of leafy greens are needed.

INVESTIGATION OF THE COMPOSITION OF LIQUID MIXTURES FOR SMOKING. DETERMINATION OF SYNTHETIC CANNABINOIDS AND α-PVP

The purpose of the article is to highlight the possibility of quantitative identification of narcotic drugs, psychotropic substances and their analogues in the context of studying the composition of liquid mixtures for smoking (vapes), to propose a method. Methodology. A set of general scientific and special methods was used to achieve this goal. In particular, using theoretical methods (analysis, generalization, comparison, modeling), systematized theoretical materials on the problems to be solved; the state of practical elaboration of the problem is empirically determined; organizational and experimental means (diagnostic, ascertaining, formative, corrective experiment) in combination with qualitative analysis and mathematical processing of the obtained results confirmed the effectiveness of the proposed method. The reliability of the results is ensured by the use of modern instrumental physicochemical, mathematical, statistical methods of analysis, as well as software processing of experimental data. Scientific novelty. The composition of liquid mixtures for smoking was determined using physicochemical methods of research, for the first time the possibility of quantitative identification of synthetic cannabinoids and α-PVP in the composition of vapes was proved. Conclusions. The composition of liquid mixtures for smoking (vapes) was determined and the possibility of quantitative identification of narcotic drugs, psychotropic substances and their analogues using various instrumental methods based on modern scientific research, in particular the content of synthetic cannabinoids and α-PVP in liquid mixtures for smoking by thin-layer, gas chromatography and using mass spectrometry. The effectiveness of current methods of researching synthetic cannabinoids was tested on specific examples and a contribution was made to the future development of methods for studying the composition of drug-containing liquid mixtures for smoking and those containing psychotropic substances, the demand for which is currently growing on the world market and in Ukraine. A method for isolating synthetic cannabinoids and α-PVP from a solution of smoking mixtures has been developed. The general approaches to the choice of the scheme of research of synthetic narcotic drugs and psychotropic substances depending on the questions, form (liquid), type and quantity of the objects submitted for research are offered.

The 12th International Conference on Instrumental Analysis—Modern Trends and Applications (20–23 September 2021, Virtual Event)

The 12th International Conference on “Instrumental Methods of Analysis” www.ima2021.gr (accessed on 8 November 2021)), was organized by the Aristotle University of Thessaloniki and National Technical University of Athens, during 20–23 September 2021 as a virtual event, providing the opportunity for high-level analytical scientists from all around the world to promote their relevant research [...]