How do cocaine and morphine in methanol solution desorb at the last moment of Leidenfrost phenomenon-assisted thermal desorption?

Rationale: The objective of the present study is to investigate desorption of low-volatility analytes in Leidenfrost phenomenon-assisted thermal desorption (LPTD).

Methods: LPTD was investigated for 5 μL solutions of 0.03 ppm cocaine or morphine in methanol (sample weight: 0.

Molecular Characterization of Isolates from Upland Cotton Roots in Uzbekistan and Whole-Genome Comparison with Isolates from the United States.

f. sp. (FOV) is a significant cotton ( spp.

Quercetin and kaempferol from saffron petals alleviated hydrogen peroxide-induced oxidative damage in B16 cells.

Background: Saffron petals are usually considered as waste after saffron harvest. However, saffron petals contain many important phytochemical components (e.g.

Most accurate mutations in SARS-CoV-2 genomes identified in Uzbek patients show novel amino acid changes.

Purpose: The rapid changes in the coronavirus genomes created new strains after the first variation was found in Wuhan in 2019. SARS-CoV-2 genotypes should periodically undergo whole genome sequencing to control it because it has been extremely helpful in combating the virus. Many diagnoses, treatments, and vaccinations have been developed against it based on genome sequencing.

Quantitative Structure-Permittivity Relationship Study of a Series of Polymers.

Dielectric constant is an important property which is widely utilized in many scientific fields and characterizes the degree of polarization of substances under the external electric field. In this work, a structure-property relationship of the dielectric constants (ε) for a diverse set of polymers was investigated. A transparent mechanistic model was developed with the application of a machine learning approach that combines genetic algorithm and multiple linear regression analysis, to obtain a mechanistically explainable and transparent model.

Tomato-made edible COVID-19 vaccine TOMAVAC induces neutralizing IgGs in the blood sera of mice and humans.

Plant-based edible vaccines that provide two-layered protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outweigh the currently used parenteral types of vaccines, which predominantly cause a systemic immune response. Here, we engineered and selected a transgenic tomato genotype (TOMAVAC) that stably synthesized an antigenic S1 protein of SARS-CoV-2. Two-course spaced force-feeding of mice with ≈5.

Bioactive Components and Biological Activities of L. Byproducts: A Comprehensive Review.

The production of saffron spice results in numerous byproducts, as only 15 g of spice can be produced from 1 kg of flowers, indicating that over 90% of the saffron flower material is eventually discarded as waste. In view of this, the paper reviews current knowledge on the natural active components in saffron byproducts and their biological activities, aiming to lay a theoretical and scientific foundation for the further utilization. Saffron byproducts contain a variety of phytochemical components, such as flavonoids, anthocyanins, carotenoids, phenolic acids, monoterpenoids, alkaloids, glycosides, and saponins.

Mass-spectrometric studies of kinetic characteristics of codeine molecule thermodesorption by non-stationary surface ionization method.

The adsorption and surface ionization of codeine molecules СHON ( 299) on the surface of oxidized tungsten have been studied by a non-stationary method of voltage modulation under the same experimental conditions with a high-vacuum mass-spectrometric setup using a "black chamber" all walls of which are cooled with liquid nitrogen. For the codeine molecule dissociation with the bond breaking and formation of ionizable radicals, the rate constants and , the activation energy and of thermodesorption, and the pre-exponential factors in the continuity equation for the radicals CHNCH ( 144) have been defined by surface ionization on the surface of oxidized tungsten . The results of determining the surface ionization coefficient and estimates of the ionization potentials of these radicals have been presented.

Chemical constituents, anti-inflammatory and analgesic activities of iridoids preparation from bunge.

This study reports the isolation of iridoids and cycloartane glycosides from the aerial parts of Bunge. Six compounds were isolated and the chemical structures were identified as phlorigidoside С (), 8--acetylharpagide (), shanzhiside methyl ester (), cyclosiversioside A (), cyclosiversioside E (), and cyclosiversioside C (). Compounds 4-6 are reported for the first time in this plant.

Profiling of the most reliable mutations from sequenced SARS-CoV-2 genomes scattered in Uzbekistan.

Due to rapid mutations in the coronavirus genome over time and re-emergence of multiple novel variants of concerns (VOC), there is a continuous need for a periodic genome sequencing of SARS-CoV-2 genotypes of particular region. This is for on-time development of diagnostics, monitoring and therapeutic tools against virus in the global pandemics condition. Toward this goal, we have generated 18 high-quality whole-genome sequence data from 32 SARS-CoV-2 genotypes of PCR-positive COVID-19 patients, sampled from the Tashkent region of Uzbekistan.

Development of surface ionization mass spectrometry for detection of stimulants in human urine.

This paper demonstrates direct detection of stimulants such as amphetamine, methamphetamine and cocaine spiked with untreated urine and a real world sample using surface ionization mass spectrometry. Spiked samples were analyzed without preliminary chromatographic separation and extraction procedure using the developed method. Moreover, in order to check the analytical capabilities of the method non-extracted real world sample was analyzed.

Phytochemical constituents and biological activities of Vved., growing in Uzbekistan.

In the present study, six known compounds were investigated that were isolated from the aerial parts of plant Vved. The structures of these compounds were identified as polypodine B (1), 2,3,20,22-diacetonide-20-hydroxyecdysone (2), 20-hydroxyecdysone (3), cyasterone (4), α-ecdysone (5) and 2-deoxy-α-ecdysone (6). Their structures were confirmed by NMR-, ESI-MS, and IR-spectroscopy.

Probe Electrospray Ionization (PESI) and Its Modified Versions: Dipping PESI (dPESI), Sheath-Flow PESI (sfPESI) and Adjustable sfPESI (ad-sfPESI).

In 2007, probe electrospray ionization/mass spectrometry (PESI/MS) was developed. In this technique, the needle is moved down along a vertical axis and the tip of the needle touched to the sample. After capturing the sample at the needle tip, the needle is then moved up and a high voltage is applied to the needle at the highest position to generate electrospray.

Examination of the effect of air atmosphere on heterogeneous reactions under surface ionization of psychotropic drug molecules.

The results of mass spectrometric studies of surface ionization of molecules of psychotropic drugs such as chlorpromazine, amitriptyline and medazepam in an air atmosphere have been presented. The channels of heterogeneous reactions occurring during the molecule adsorption on the hot surface of the thermoemitter from refractory metal oxides have been revealed, as well as the influence of air atmosphere on these reactions. A strong influence of the air atmosphere on the heterogeneous association reactions with the emission of [M + H] ions has been found.

Flash desorption of low-volatility compounds deposited on a heated solid substrate (90°C) by dripping liquid methanol.

Rationale: Desorption of low-volatility compounds deposited on a solid substrate by dripping a methanol drop was explored.

Methods: Low-volatility compounds such as drugs and explosives were deposited/dried on the substrate at 35°C. After increasing the temperature to 90°C, 5 μL methanol was dripped onto the substrate.

Robotic sheath-flow probe electrospray ionization/mass spectrometry (sfPESI/MS): development of a touch sensor for samples in a multiwell plastic plate.

In the previous work, sheath-flow probe electrospray ionization (sfPESI) equipped with a touch sensor was developed for conducting samples. In this work, a capacitiance-sensitive touch sensor that can be applicable to samples prepared in a nonconducting plastic multiwell plate was developed. The radiofrequency with 5 kHz and 4.

Iridoid glucosides and triterpene acids from , growing in Uzbekistan and its hepatoprotective activity.

A number of iridoids and triterpene acids, such as pulchelloside, sesamoside, shanshiside methyl ester, barlerin, gypsogenin acid and acetate of gypsogenic acid were isolated from the aerial part of and their structures were confirmed by NMR, mass and IR spectroscopy. In addition, the hepatoprotective potential of iridoid fraction from P. linearifolia aerial parts was tested against CCl induced fibrosis in rats.

Direct detection of morphine in human urine by surface-ionization mass spectrometry.

Detection and analysis of drugs-of-abuse in biological fluids are the essential tasks for the law enforcement, forensic toxicology, doping research and social health. In this work, we developed a surface-ionization mass spectrometry method for direct detection of trace amount of morphine spiked in blank urine. The mass-spectrometric analysis of spiked samples was carried out without preliminary extraction and chromatographic separation.

Electrospray Generated from the Tip-Sealed Fine Glass Capillary Inserted with an Acupuncture Needle Electrode.

In electrospray, excess charges are supplied to a sample solution by the occurrence of electrochemical reactions. Recently, different versions of electrospray, e.g.

Dipping probe electrospray ionization/mass spectrometry for direct on-site and low-invasive food analysis.

Rapid, direct, on-site and noninvasive food analysis is strongly needed for quality control of food. To satisfy this demand, the technique of dipping probe electrospray ionization/mass spectrometry (dPESI/MS) was developed. The sample surface was pricked with a fine acupuncture needle and a sample of ∼200 pL was captured at the needle tip.

Remote sampling mass spectrometry for dry samples: Sheath-flow probe electrospray ionization (PESI) using a gel-loading tip inserted with an acupuncture needle.

Rationale: Probe electrospray ionization (PESI) is only applicable to liquid or wet samples. In this study, a sheath-flow PESI method for remote sampling mass spectrometry that can be applied to dry samples was developed.

Methods: An acupuncture needle (0.

Non-proximate mass spectrometry using a heated 1-m long PTFE tube and an air-tight APCI ion source.

Direct and rapid trace-level gas analysis is highly needed in various fields such as safety and security, quality control, food analysis, and forensic medicine. In many cases, the real samples are bulky and are not accessible to the space-limited ion source of the mass spectrometer. In order to circumvent this problem, we developed an airtight atmospheric-pressure chemical ionization (APCI) ion source equipped with a flexible 1-m-long, 2-mm-i.

Desorption in Mass Spectrometry.

In mass spectrometry, analytes must be released in the gas phase. There are two representative methods for the gasification of the condensed samples, , ablation and desorption. While ablation is based on the explosion induced by the energy accumulated in the condensed matrix, desorption is a single molecular process taking place on the surface.

Mass spectrometric monitoring of oxidation of aliphatic C6-C8 hydrocarbons and ethanol in low pressure oxygen and air plasmas.

Experimental and theoretical studies on the oxidation of saturated hydrocarbons (n-hexane, cyclohexane, n-heptane, n-octane and isooctane) and ethanol in 28 Torr O or air plasma generated by a hollow cathode discharge ion source were made. Ions corresponding to [M + 15] and [M + 13] in addition to [M - H] and [M - 3H] were detected as major ions where M is the sample molecule. The ions [M + 15] and [M + 13] were assigned as oxidation products, [M - H + O] and [M - 3H + O] , respectively.