hypochromism (i.e., association) in two pyrimidine-C3-pyrimidine series, upon increasing alkyl group size, but decreased quantum yields of dimerization. (a) Replacing the 5-methyl group in T-Qj-T by ethyl: K. Golankiewicz and L. Strekowski, Mol. Photochem., 4,189 (1972). (b) Increasing the size of the 3-alkyl group in bis-3-alkylated T-C3-T derivatives: K. Golankiewicz and A. Zasada-Parzynska, Bull. Acad. Pol. Scl., 22, 945 (1974).(35) The triplet 1,4 diradical which precedes dimer closes three times less efficiently for thymine than for uracil, a result attributed to the steric barrier of the 5-methyl group: P. J. Wagner and D. J. Bucheck, J. Am. Chem. Soc., 92, 181 (1970). (36) Triplet derived dimers are quenchable and several arguments make short-lived triplet aggregates unlikely precursors in the unquenchable dimerization. c (37) There is no quenching by 0.1 M pipery lene, the concentration of diene which is sufficient to trap all TMU triplets (cf. the 0isc data) and is sufficient to trap all DMT triplets.50 Very high diene concentrations do give some quenching as do high concentrations of vinyl acetate and tetramethylethylene. This may be due to small amounts of singlet quenching or result from an interference with association. DMT singlet dimerization can be completely eliminated by CCI4, presumably through a charge-transfer quenching mechanism: D.

Background Tremendous amounts of data generated from microbiome research studies during the last decades require not only standards for sampling and preparation of omics data but also clear concepts of how the metadata is prepared to ensure re-use for integrative and interdisciplinary microbiome analysis. Results In this Commentary, we present our views on the key issues related to the current system for metadata submission in omics research, and propose the development of a global metadata system. Such a system should be easy to use, clearly structured in a hierarchical way, and should be compatible with all existing microbiome data repositories, following common standards for minimal required information and common ontology. Although minimum metadata requirements are essential for microbiome datasets, the immense technological progress requires a flexible system, which will have to be constantly improved and re-thought. While FAIR principles (Findable, Accessible, Interoperable, and Reusable) are already considered, international legal issues on genetic resource and sequence sharing provided by the Convention on Biological Diversity need more awareness and engagement of the scientific community. Conclusions The suggested approach for metadata entries would strongly improve retrieving and re-using data as demonstrated in several representative use cases. These integrative analyses, in turn, would further advance the potential of microbiome research for novel scientific discoveries and the development of microbiome-derived products.

The investigations applied the original concept of the formation of materials as hybrid gradient composites. Two innovative technologies were used: formation by centrifugal slip casting and sintering with varying proportions of the liquid phase. This allowed us to create a gradient microstructure. This article presents the study of Al2O3-Cu-Mo gradient composites. This work aimed to determine the effect of the metallic phase content on the composite’s microstructure and basic properties. The most critical element of the study will be determining the ability to control the location and flow of the liquid phase during the sintering process. The research demonstrated that adding a third component in the form of Mo reduces the liquid Cu flow onto the surface of the composites during the sintering process. In this research, we achieve results with high cognitive value. Graphic Abstract

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The paper presents the possibility of fabricating ceramic-metal composites by an innovative method of centrifugal slip casting in the magnetic field. It was examined whether the use of this method would allow obtaining a gradient concentration of metal particles in the ceramic matrix. In the applied technique, the horizontal rotation axis was used. The study investigated the effect of solid phase content on the properties and microstructure of the products. Water-based suspensions with 35, 40, 45 and 50 vol.% of solid-phase content were prepared with 10 vol.% additional of nickel powder. The viscosity of prepared slurries was considered. The gradient distribution of nickel particles in the zirconia matrix was observed on SEM. Vickers hardness of ZrO 2 -Ni composites has been measured. The research revealed that the physical properties depend on the volume fraction of solid content and increase as the volume of solid content increases.