Synthesis and hybridizing properties of P-stereodefined chimeric [PS]-{DNA:RNA} and [PS]-{DNA:(2'-OMe)-RNA} oligomers.

Oxathiaphospholane derivatives of 2'-OMe-ribonucleosides and 2'--TBDMS-ribonucleosides (N-OTP and N-OTP, respectively; nucleobase protected) were synthesized and separated into pure P-diastereomers. X-ray analysis showed the absolute configuration of the phosphorus atom in the -eluting diastereomer of A-OTP. The - and -eluting P-diastereomers of N-OTP and N-OTP were used in the solid-phase synthesis of phosphorothioate dinucleotides (NT and NT, respectively), which were subsequently hydrolyzed with -selective phosphodiesterase svPDE and -selective nuclease P1 to determine the absolute configuration of the phosphorus atoms.

Artificial Intelligence Approach to the Monitoring of Respiratory Sounds in Asthmatic Patients.

Effective and reliable monitoring of asthma at home is a relevant factor that may reduce the need to consult a doctor in person. We analyzed the possibility to determine intensities of pathological breath phenomena based on artificial intelligence (AI) analysis of sounds recorded during standard stethoscope auscultation. The evaluation set comprising 1,043 auscultation examinations (9,319 recordings) was collected from 899 patients.

Boron clusters as a platform for new materials: composites of nucleic acids and oligofunctionalized carboranes (CBH) and their assembly into functional nanoparticles.

Nucleic acids are key biomolecules in all life forms. These biomolecules can encode and transfer information via Watson-Crick base-pairing interactions and can form double-stranded structures between complementary sequences with high precision. These properties make nucleic acids extremely successful in applications in materials science as nanoconstruction materials.

A Flp-SUMO hybrid recombinase reveals multi-layered copy number control of a selfish DNA element through post-translational modification.

Mechanisms for highly efficient chromosome-associated equal segregation, and for maintenance of steady state copy number, are at the heart of the evolutionary success of the 2-micron plasmid as a stable multi-copy extra-chromosomal selfish DNA element present in the yeast nucleus. The Flp site-specific recombination system housed by the plasmid, which is central to plasmid copy number maintenance, is regulated at multiple levels. Transcription of the FLP gene is fine-tuned by the repressor function of the plasmid-coded partitioning proteins Rep1 and Rep2 and their antagonist Raf1, which is also plasmid-coded.

Homopurine R-stereodefined phosphorothioate analogs of DNA with hampered Watson-Crick base pairings form Hoogsteen paired parallel duplexes with (2'-OMe)-RNAs.

3'-O-(2-Thio-4,4-pentamethylene-1,3,2-oxathiaphospholane) derivatives of 5'-O-DMT-N6-methyl-deoxyadenosine and 5'-O-DMT-N2,N2-dimethyl-O6-diphenylcarbamoyl-deoxyguanosine (OTP-NY, NY = DMT-m6dA or DMT-m,m2dGDPC) were synthesized, resolved onto pure P-diastereomers, and used in P-stereocontrolled synthesis of dinucleoside 3',5,-phosphorothioates NXPST (NX = m6dA or m,m2dG), in which the absolute configuration of the stereogenic phosphorus atom was established enzymatically. Diastereomerically pure OTP-NY and standard OTP-N (N = DMT-dABz or DMT-dGBz,DPC) were used in the synthesis of chimeric RP-stereodefined phosphorothioate oligomers ((RP-PS)-DN(NX)A) with hampered Watson-Crick base pairings. It was found that the m6dA units slightly reduce the thermodynamic stability of antiparallel duplexes formed with RNA and (2'-OMe)-RNA matrices, whereas m,m2dG units prevent their formation.