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Ikaite is a calcium carbonate hexahydrate that forms at temperatures close to the freezing point of water; thus, its occurrence is associated with cryogenic conditions. This mineral is metastable and quickly transforms to calcite at temperatures above 5 °C. Pseudomorphs of calcite after ikaite are known as glendonite. The nanostructure of 25 000–43 000 year old glendonite from Victoria cave (Southern Ural, Russia) was investigated in search of structural features indicative of the ikaite-to-calcite transformation. Scanning electron microscope images display several micrometer- to submicrometer-size pores and indicate high intergranular porosity among the loosely aggregated grains. Transmission electron microscopy (TEM) data show evidence of 10–20 nm nanotwins [twin law (1014)] and 10–40 nm overlapping nanograins. Scanning TEM images reveal that the individual grains contain 5–10 nm long and 2–4 nm wide mesopores (sizes between 2 and 50 nm), which are aligned parallel to [1010] of calcite and might be associated with a crystallographically oriented dehydration of the precursor ikaite. Fourier transform infrared spectroscopy reveals no evidence of structural water but absorption bands related to molecular water trapped in fluid inclusions are present. Nitrogen absorption/desorption measurements show that the specific surface area of 5.78 m2/g and the pore volume of ~0.07 cm3/g for calcite, the constituent of glendonite, are comparable to those of a common natural calcite. We suggest that the aligned mesopores, frequently occurring twins, small grain size, presence of aqueous inclusions and the high micrometer- to submicrometer-size intergranular porosity arise from the ikaite-to-calcite transformation and thus may be used as criteria for the former presence of ikaite and hence for cold paleotemperatures. However, since similar features might also be common in biogenic carbonates, the diagnostic macroscopic pseudomorphs after ikaite are equally important for identifying glendonites and inferring cryogenic conditions.

Bizonyos nyomelemek ionos, illetve komplexen kötött vegyületei nélkülözhetetlenek számtalan biokémiai folyamatban, a humán szervezet megfelelő működéséhez. Hiányuk vagy akkumulációjuk számos egészségügyi problémát, betegséget okoz. Korábban az inzulinrezisztencia és a cukorbetegség kezelésében a nyomelemeket kulcsfontosságú faktornak gondolták, azonban a diabetes kialakulásában a nyomelemek hiánya, fontossága vagy a szövődmények kialakulásában és kezelésében a nyomelemstatus megítélése, a pótlás fontossága még ma is ellentmondásos. A szerzők ezért áttekintik a nyomelemek szerepét a diabetes kialakulásában, patogenezisében és progressziójában. Röviden beszámolnak a cink(II), a mangán(II, III), a réz(I, II), a króm(III), a vas(II, III), a kobalt(II), a vanádium(III, IV, V), a molibdén(IV, VI), a jód(I), a szelén(II, IV, VI) és a lítium(I) humán szervezetben ismert legfontosabb folyamatairól és a diabetesszel összefüggő biokémiai változásokról. Részletezik a nyomelemstatus eltéréseit diabetesben, kapcsolatukat a szabad gyökökkel és az antioxidáns védelmi rendszerrel. Rátérnek néhány rizikófaktor tárgyalására, amely súlyosabb mikroelemhiányhoz és szövődmények kialakulásához vezet. Orv Hetil. 2022; 163(33): 1303–1310.

Spray freeze-drying (SFD) is an effective method for reducing the size of thermosensitive organic substances that are sparingly soluble in water. Despite the advantages of the method, its use has not yet become widespread. We aimed at studying SFD technique for metronidazole as a heat-sensitive active pharmaceutical ingredient for reducing its particle size and investigated the morphological and physical parameters of the modified drug.The obtained particles were crystalline in all cases and their sizes were two and one order of magnitude smaller using water or dimethyl sulphoxide solutions, respectively, as compared to the initial reference metronidazole. The particle size varied depending on the experimental parameters (atomization pressure, peristaltic pump speed), although, the operating parameters had a smaller effect on the size of the materials than the applied concentration of starting solution, regardless of the solvent. The as-prepared samples had a microcrystalline structure that is retained for a long time.

Ionic or complex compounds of certain trace elements are essential for the proper functioning of the human body in numerous biochemical processes. Their absence or accumulation causes many health problems and diseases. In the past, trace elements have been thought to be a key factor in the treatment of insulin resistance and diabetes, however, the importance and lack of trace elements in the development of diabetes or the assessment of trace element status in the development and treatment of complications are still controversial. Therefore, the authors summarize the role of trace elements in the development, pathogenesis, and progression of diabetes. They briefly report on the most important known processes of zinc(II), manganese(II, III), copper(I, II), chromium(III), iron(II, III), cobalt(II), vanadium(III, IV, V), molybdenum(IV, VI), iodine(I), selenium(II, IV, VI), and lithium(I) in the human body and the biochemical changes associated with diabetes. Differences in trace element status in diabetes, their relationship to free radicals, and the antioxidant defense system are detailed. Some risk factors that lead to more severe micronutrient deficiencies and complications are also discussed.Bizonyos nyomelemek ionos, illetve komplexen kötött vegyületei nélkülözhetetlenek számtalan biokémiai folyamatban, a humán szervezet megfelelő működéséhez. Hiányuk vagy akkumulációjuk számos egészségügyi problémát, betegséget okoz. Korábban az inzulinrezisztencia és a cukorbetegség kezelésében a nyomelemeket kulcsfontosságú faktornak gondolták, azonban a diabetes kialakulásában a nyomelemek hiánya, fontossága vagy a szövődmények kialakulásában és kezelésében a nyomelemstatus megítélése, a pótlás fontossága még ma is ellentmondásos. A szerzők ezért áttekintik a nyomelemek szerepét a diabetes kialakulásában, patogenezisében és progressziójában. Röviden beszámolnak a cink(II), a mangán(II, III), a réz(I, II), a króm(III), a vas(II, III), a kobalt(II), a vanádium(III, IV, V), a molibdén(IV, VI), a jód(I), a szelén(II, IV, VI) és a lítium(I) humán szervezetben ismert legfontosabb folyamatairól és a diabetesszel összefüggő biokémiai változásokról. Részletezik a nyomelemstatus eltéréseit diabetesben, kapcsolatukat a szabad gyökökkel és az antioxidáns védelmi rendszerrel. Rátérnek néhány rizikófaktor tárgyalására, amely súlyosabb mikroelemhiányhoz és szövődmények kialakulásához vezet. Orv Hetil. 2022; 163(33): 1303–1310.

Glycerol is an important starting material for the synthesis of many chemical compounds and its selective oxidation represents an efficient way to produce value-added compounds. Glyceric acid, one of these selective oxidation products, is an important intermediate in the food, medicine, cosmetics, and light industries. In this work, four commercially available native laccases were screened for glycerol oxidation using different initiators, and the two most efficient biocatalysts were covalently immobilized on functionalized magnetic and polymethacrylate (Lifetech™) solid supports. Apart from the mostly employed Fe

Wood modification is an excellent and increasingly used method to expand the application of woody materials. Traditional methods, such as chemical or thermal, have been developed for the targeted improvement of some selected properties, unfortunately typically at the expense of others. These methods generally alter the composition of wood, and thus its mechanical properties, and enhance dimensional stability, water resistance, or decrease its susceptibility to microorganisms. Although conventional methods achieve the desired properties, they require a lot of energy and chemicals, therefore research is increasingly moving towards more environmentally friendly processes. The advantage of modern methods is that in most cases, they only modify the surface and do not affect the structure and mechanical properties of the wood, while reducing the amount of chemicals used. Cold plasma surface treatment is one of the cheapest and easiest technologies with a limited burden on the environment. In this review, we focus on cold plasma treatment, the interaction between plasma and wood compounds, the advantages of plasma treatment compared to traditional methods, and perspectives.