Effect of a mixture of caffeine and nicotinamide on the solubility of vitamin (B2) in aqueous solution

The effect of caffeine (CAF) and nicotinamide (NMD) on the solubility of a vitamin B2 derivative (FMN) has been evaluated for mixtures containing either a single hydrotrope (CAF or NMD) or the two hydrotropes simultaneously. A model for analysis of ternary systems, which takes into account all possible complexes between the molecules, has been developed and tested with experimental NMR data on the three-component mixture FMN–CAF–NMD. The results indicate that special attention should be given to the concentration of a hydrotropic agent used to enhance the solubility of a particular drug. A decrease in the efficacy of solubility of the vitamin on addition of large amounts of hydrotropic agent is expected in the two-component systems due to the increased proportion of self-association of the hydrotrope. It is found that a mixture of two hydrotropic agents leads to an increase in the solubility of the vitamin in three-component compared to the two-component system. Rather than using just one hydrotropic agent, it is proposed that a strategy for optimising the solubility of aromatic drugs is to use a mixture of hydrotropic agents

Hetero-association of aromatic molecules in aqueous solution

Knowledge of the physical chemistry of small molecules complexation (the hetero-association) in aqueous solution is increasingly important in view of the rapidly emerging branch of supramolecular chemistry dealing with the formation of heterogeneous polymeric structures having specific functional roles. In this paper, the 50-year history of scientific studies of hetero-association of heterocyclic aromatic molecules in aqueous solution has been reviewed. Some important correlations of structural and thermodynamic parameters of complexation have been reported based on large data-set of hetero-association parameters accumulated to date. The fundamental problem of ‘energetic composition’ of π-stacking is extensively discussed. The review has shown that there are some gaps in our understanding of heteroassociation, which provides a challenge for further studies in this are

Project of VEPP-2000 electron-positron collider

The status of VEPP-2M collider is presented. Implementation of Round Colliding Beams (RCB) concept in the new collider VEPP-2M is outlined, potential advantages of RCB over the flat colliding beams are discussed. The main desing parameters and features of this VEPP-2000 collider are reported

Figs 8–14 in New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species

Figs 8–14. Tephritis conura from European Russia (Ulyanovsk Prov.), details of female (8–13) and male (14). 8–9, female wing; 10, female habitus (in lateral view); 11, aculeus; 12, apex of aculeus (at large magnification); 13, spermatheca; 14, glans of phallus. 8–9, 11–14, reared from Cirsium heterophyllum, 10, reared from C. oleraceum.Published as part of <i>Evstigneev, D.A. & Przhiboro, A.A., 2021, New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species, pp. 13-24 in Zoosystematica Rossica (Zoosyst. Rossica) 30 (1)</i> on page 18, DOI: 10.31610/zsr/2021.30.1.13, <a href="http://zenodo.org/record/10124230">http://zenodo.org/record/10124230</a&gt

Figs 32–39 in New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species

Figs 32–39. Tephritis valida from Armenia (32, 34, 38) and North Ossetia–Alania (33, 35–37, 39), details of female (32–33, 35–39) and male (34). 32, female habitus (in lateral view); 33, female wing; 34, glans of phallus; 35, female abdomen (in lateral view); 36, aculeus; 37, distal part of aculeus (magnified); 38–39, spermatheca.Published as part of <i>Evstigneev, D.A. & Przhiboro, A.A., 2021, New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species, pp. 13-24 in Zoosystematica Rossica (Zoosyst. Rossica) 30 (1)</i> on page 21, DOI: 10.31610/zsr/2021.30.1.13, <a href="http://zenodo.org/record/10124230">http://zenodo.org/record/10124230</a&gt

Figs 15–23 in New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species

Figs 15–23. Tephritis mutabilis from Armenia, details of female (15–22) and male (23). 15, female habitus (in lateral view); 16, female wing; 17, female abdomen (in dorsal view); 18, female abdomen (in lateral view); 19, aculeus; 20, distal part of aculeus (magnified); 21, apex of aculeus (at large magnification); 22, spermatheca; 23, glans of phallus.Published as part of <i>Evstigneev, D.A. & Przhiboro, A.A., 2021, New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species, pp. 13-24 in Zoosystematica Rossica (Zoosyst. Rossica) 30 (1)</i> on page 19, DOI: 10.31610/zsr/2021.30.1.13, <a href="http://zenodo.org/record/10124230">http://zenodo.org/record/10124230</a&gt

Figs 40–47 in New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species

Figs 40–47. Sphenella marginata (40–43) and Ensina sonchi (44–47), details of female (40–42, 45–46) and male (43, 44, 47). 40, female wing; 41, 45, aculeus; 42, 46, distal part of aculeus (magnified); 43, 47, glans of phallus; 44, male wing.Published as part of <i>Evstigneev, D.A. & Przhiboro, A.A., 2021, New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species, pp. 13-24 in Zoosystematica Rossica (Zoosyst. Rossica) 30 (1)</i> on page 22, DOI: 10.31610/zsr/2021.30.1.13, <a href="http://zenodo.org/record/10124230">http://zenodo.org/record/10124230</a&gt

Figs 1–7 in New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species

Figs 1–7. Tephritis anthrax from North Ossetia–Alania, details of female (1–2, 4–7) and male (3). 1, female habitus (in lateral view); 2, female wing; 3, glans of phallus; 4, spermatheca; 5, aculeus; 6, distal part of aculeus (magnified); 7, apex of aculeus (at large magnification).Published as part of <i>Evstigneev, D.A. & Przhiboro, A.A., 2021, New records of flies of the genus Tephritis (Diptera: Tephritidae) from the Caucasus and Transcaucasia, with notes on other tephritid species, pp. 13-24 in Zoosystematica Rossica (Zoosyst. Rossica) 30 (1)</i> on page 17, DOI: 10.31610/zsr/2021.30.1.13, <a href="http://zenodo.org/record/10124230">http://zenodo.org/record/10124230</a&gt