Base pairs with 4-amino-3-nitrobenzonitrile: comparison with the natural WC pairs. Dimer and tetramer forms, Infrared and Raman spectra, and several proposed antiviral modified nucleosides.

Base pairs of 4-amino-3-nitrobenzonitrile (4A-3NBN) molecule with uracil, thymine and cytosine nucleobases were optimized and compared to natural Watson-Crick (WC) pairs. The slightly greater flexibility of the -NO2 group of 4A-3NBN than the N3-H group of the natural nucleobases together with a noticeable higher dipole moment of its pairs can facilitate disruption of the DNA/RNA helix formation. Several new mutagenic modified nucleosides with 4A-3NBN and 3-amino-2-nitrobenzonitrile (3A-2NBN) were proposed as antiviral prodrugs and their base pairs optimized. The special characteristics of these prodrugs appear appropriated for their clinical use. The counterpoise (CP) corrected interaction energies of the base pairs were calculated and compared to the natural ones. The M06-2X DFT method was used for this purpose. The molecular structure of 4A-3NBN was analyzed in detail and the crystal unit cell was simulated by a tetramer form and eight dimer forms. The performance of the B3LYP, X3LYP and M06-2X methods was tested on the vibrational wavenumbers in the monomer, dimer and tetramer forms of 4A-3NBN. The observed IR and Raman bands were assigned according to the optimum dimer II form determined by B3LYP and by the tetramer form calculated by M06-2X, which is the expected unit cell that forms the crystal net. The two best scaling procedures were used.Communicated by Ramaswamy H. Sarma.

Virtual Simulation for Last-Year Nursing Graduate Students in Times of Covid-19: A Quasi-Experimental Study.

BACKGROUND: The COVID-19 pandemic has made it necessary to adapt university health-education. Virtual simulation has been proposed to be a suitable tool. METHODS: A quasi-experimental study was conducted on nursing students in the final year. The virtual simulation platform vSim® was used. Improvements in knowledge, skills during simulation, satisfaction and selfconfidence obtained through the training provided were analyzed, as well as satisfaction with the platform. RESULTS: Prepost training knowledge improved. Skill acquisition improved between the first and last attempts in all cases. The levels of selfconfidence and satisfaction with the training and the platform used were high. CONCLUSIONS: The vSim® was a useful solution during the pandemic. Knowledge improved and high selfconfidence was obtained.

DFT calculation of four new potential agents muscarinic of bispyridinium type: structure, synthesis, biological activity, hydration, and relations with the potents W84 and DUO-3O.

Four new potential agents muscarinic (allosteric modulators) were synthesized and studied by using the B3LYP density functional method. The optimum conformation and geometry structure of these compounds were determined and analyzed. Solvent effects were considered including a variable number (1-15) of explicit water molecules surrounding the compound in order to simulate the first hydration shell, as well as using the Tomasi's polarized continuum model (PCM). A similar simultaneous analysis of the potents W84 and DUO-3O allosteric modulator of muscarinic receptors was also carried out. The effect of the hydration on the total atomic charges and several intermolecular distances of interest were also discussed. The biological activity against acetylcholine of our four synthesized bispyridinium salts was determined. Relationships/tendencies structure-activity were established. Several general conclusions were underlined.

[Beer and cardiovascular disease. Systematic bibliographic review (meta-analysis)]. / Cerveza y enfermedad cardiovascular. Revisión bibliográfica sistemática (metaanálisis).

MAIN OBJECTIVES: The aims of the present study are: To carry out a systematic revision of the printed literature on beer consumption and its possible effects on human health. To analyze the possibility of applying techniques used in epidemiological studies considering meta-analysis as the most important element. Meta-analysis is a set of different statistical techniques that aim to get a quantitative and qualitative synthesis of the results of different independent studies on the same subject. METHODS: First we proceed to carry out the bibliographical search and compilation by means of the following Date-Bases: Medline, Embase and Toxline. Beer is used as key word, specifying the time period between January, 1998 and May, 2000. A total of 403 reference works are obtained and subjected to the corresponding criteria of inclusion and exclusion. RESULTS: The meta-analysis of the selected studies related to cardiovascular disease provides an OR of 0.89 (0.89-0.97) which shows that the group of risk falls ill in less cases than the non-exposed. CONCLUSIONS: Beer consumption: possible factor of cardiovascular protection. Nevertheless we must take this consideration with as much caution as possible. It is necessary to determine the effects of beer consumption on the Spanish population.