Standardization of the protocol for oral cavity examination and collecting of the biological samples for microbiome research using the next-generation sequencing (NGS): own experience with the COVID-19 patients.

To date, publications have shown that compositions of oral microbiota differ depending on their habitats (e.g. tongue, tonsils, pharynx).

Oral microbiota study of the patients after hospitalisation for COVID-19, considering selected dental indices and antibiotic therapy using the next generation sequencing method (NGS).

Background: Poor oral hygiene and the increased incidence and severity of periodontitis may exacerbate SARS-CoV-2 infection. The aim was to evaluate the oral microbiota of 60 participants divided into groups: COVID-19 convalescents who received antibiotics during hospitalization (I), COVID-19 convalescents without antibiotic therapy (II) and healthy individuals (III).

Materials And Methods: Dental examination was conducted, and oral health status was evaluated using selected dental indexes.

Glacier Geometry Changes in the Western Shore of Admiralty Bay, King George Island over the Last Decades.

This paper presents changes in the range and thickness of glaciers in Antarctic Specially Protected Area (ASPA) No. 128 on King George Island in the period 1956-2015. The research indicates an intensification of the glacial retreat process over the last two decades, with the rate depending on the type of glacier front.

Curcuminoids and acetylacetone: iron complexes as studied by electrospray ionization mass spectrometry.

Curcumin complexes with iron ions were investigated by electrospray ionization mass spectrometry. It was shown that in methanol solutions of curcumin and iron(III) ions, complexes are formed with a stoichiometry of 1 : 1, 2 : or 3 : 1. Curcumi-iron(II) complexes were created only with the 1 : 1 stoichiometry.

Mass spectrometric behavior of phenolic acids standards and their analysis in the plant samples with LC/ESI/MS system.

Liquid chromatography coupled to mass spectrometry (MS) with electrospray ionization (ESI) is one of analytical techniques to obtain accurate results of low molecular weight aromatic compounds in biological samples of different origin. The interpretations of mass spectra of these aromatic compounds in the negative spectra registered in the full scan MS mode may be uneasy due to presence of deprotonated molecules [M-H](-) from different co-eluting entities, fragment ions created after the break-up of precursor ions and also ions representing modified molecules clusters. Thus, the first aim of this study was to evaluate general parameters during analysis performed in the full scan MS or MS/MS mode.

Formation of curcumin molecular ion under electrospray ionisation conditions in the presence of metal cations.

Electrospray ionisation (ESI) mass spectra obtained for solutions containing curcumin, copper cation and other metal cations, namely Co2+, Ni2+, Mn2+ and Zn2+, have shown an abundant curcumin molecular ion at m/z 368. This ion was not formed for solutions containing curcumin and copper cations or for those containing curcumin and other metal cations. To the best of our knowledge, it is the first example of a system in which copper cations and other metal cations promote formation of organic radical cation under ESI conditions.

Formation of diclofenac molecular ions as the effect of Cu(2+)-π interaction under electrospray ionization mass spectrometry conditions.

Solutions containing diclofenac (M) and a copper salt [CuCl2, Cu(ClO4)2, Cu(NO3)2, CuSO4) were analysed by electrospray ionisation mass spectrometry (ESI-MS). Because of the cation-pi interactions in diclofenac-Cu(II) complexes, the diclofenac molecular ion M+* at m/z 295 was formed. It was found that the solvent composition (methanol versus water/methanol) and counter ion strongly affect the M+* ion formation.

Multinuclear magnetic resonance studies of 2-aryl-1,3,4-selenadiazoles.

2-Aryl-1,3,4-selenadiazoles were studied by (1) H, (13) C, (15) N and (77) Se NMR spectroscopy. The results (chemical shifts and coupling constants) were correlated with Hammett substituent parameters as well as calculated chemical shifts and bond lengths.