Kinetic preference for interaction of cisplatin with the G-C-rich wobble basepair region in both tRNAAla and MhAla

The anticancer active complex cisplatin interacts preferentially with the common, G-C rich, wobble base pair region of both tRNA(Ala) and Mh(Ala) in a reaction that at pH 6.3 is rate limited by the acid hydrolysis of the metal complex.     

Wigner-Ville distribution for pulse propagation in random media: pulsed plane wave

The time-frequency Wigner-Ville distribution for a pulsed plane-wave signal propagating in a continuous random medium is found, based on the previously derived modal series expression for the two-frequency coherence function. The theory can address propagation in any homogeneous isotropic random medium, but closed-form expressions are specifically derived for a general power-law medium. Two alternative formulations are presented: a modal-wavefront approach wherein each mode is asymptotically transformed to the time domain and a collective approach wherein the mode series is summed collectively and then transformed to the time domain using pole contributions. The physical interpretation of these two different representations in the time-frequency domain as either a superposition of localized wavefronts or collective excitations is established, and their applications to the calculation of local moments are considered.     

Classical Solutions of Nonautonomous Riccati Equations Arising in Parabolic Boundary Control Problems, II

An abstract linear-quadratic regulator problem over finite time horizon is considered; it covers a large class of linear nonautonomous parabolic systems in bounded domains, with boundary control of Dirichlet or Neumann type. We give the proof of some result stated in [AT5], and in addition we prove uniqueness of the Riccati operator, provided its final datum is suitably regular. Accepted 14 October 1998     

Modal theory for the two-frequency mutual coherence function in random media: general theory and plane wave solution: I

In this paper, the modal expansion theory is presented as a new analytical approach together with the resulting new physical parameters. In particular, the features of an arbitrary power-law structure function are investigated. The exact expression for the Gaussian spectrum is rederived. An approximate analytical expression for the two-frequency coherence function evaluated at equal positions for the Kolmogorov spectrum is presented and comparison with the numerical solution in the literature exhibits a remarkable agreement. As a result of the modal decomposition, general properties for a transversally homogeneous and isotropic medium are demonstrated, such as the exponential decay of the amplitude of the solution and the linear phase behaviour at large propagation distances.     

Developing a Library of Mannose-Based Mono- and Disaccharides: A General Chemoenzymatic Approach to Monohydroxylated Building Blocks

Regioselective deprotection of acetylated mannose-based mono- and disaccharides differently functionalized in anomeric position was achieved by enzymatic hydrolysis. Candida rugosa lipase (CRL) and Bacillus pumilus acetyl xylan esterase (AXE) were immobilized on octyl-Sepharose and glyoxyl-agarose, respectively. The regioselectivity of the biocatalysts was affected by the sugar structure and functionalization in anomeric position. Generally, CRL was able to catalyze regioselective deprotection of acetylated monosaccharides in C6 position. When acetylated disaccharides were used as substrates, AXE exhibited a marked preference for the C2, or C6 position when C2 was involved in the glycosidic bond. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monohydroxylated building blocks that could be used as intermediates for the synthesis of mannosylated glycoconjugate vaccines targeting mannose receptors of antigen presenting cells.     

On-Chip Neo-Glycopeptide Synthesis for Multivalent Glycan Presentation

Single glycan–protein interactions are often weak, such that glycan binding partners commonly utilize multiple, spatially defined binding sites to enhance binding avidity and specificity. Current array technologies usually neglect defined multivalent display. Laser-based array synthesis technology allows for flexible and rapid on-surface synthesis of different peptides. By combining this technique with click chemistry, neo-glycopeptides were produced directly on a functionalized glass slide in the microarray format. Density and spatial distribution of carbohydrates can be tuned, resulting in well-defined glycan structures for multivalent display. The two lectins concanavalin A and langerin were probed with different glycans on multivalent scaffolds, revealing strong spacing-, density-, and ligand-dependent binding. In addition, we could also measure the surface dissociation constant. This approach allows for a rapid generation, screening, and optimization of a multitude of multivalent scaffolds for glycan binding.     

Essential Oil of Cannabis sativa L: Comparison of Yield and Chemical Composition of 11 Hemp Genotypes

Cannabis sativa L. is an annual species cultivated since antiquity for different purposes. While, in the past, hemp inflorescences were considered crop residues, at present, they are regarded as valuable raw materials with different applications, among which extraction of the essential oil (EO) has gained increasing interest in many fields. The aim of the present study is the evaluation of the yield and the chemical composition of the EO obtained by hydrodistillation from eleven hemp genotypes, cultivated in the same location for two consecutive growing seasons. The composition of the EOs was analyzed by GC–MS, and then subjected to multivariate statistical analysis. Sesquiterpenes represented the main class of compounds in all the EOs, both in their hydrocarbon and oxygenated forms, with relative abundances ranging from 47.1 to 78.5%; the only exception was the Felina 32 sample collected in 2019, in which cannabinoids predominated. Cannabinoids were the second most abundant class of compounds, of which cannabidiol was the main one, with relative abundances between 11.8 and 51.5%. The statistical distribution of the samples, performed on the complete chemical composition of the EOs, evidenced a partition based on the year of cultivation, rather than on the genotype, with the exception of Uso-31. Regarding the extraction yield, a significant variation was evidenced among both the genotypes and the years of cultivation.