Location and base selectivity on fragmentation of brominated oligodeoxynucleotides

Bromine-modified oligodeoxynucleotides (ODNs) were fragmented in the electrospray source to study the influence of brominated bases on fragmentation. Several 13-mer ODNs containing a brominated pyrimidine base, BrdU (5-bromodeoxyuridine) or BrdC (5-bromodeoxycytidine), were analyzed. Low cone voltage fragmentation yields a loss of the brominated base with a preferential loss for the brominated base closer to the 5'-end (2-position > 4-position > 12-position) as well as a preferential loss of BrdU over BrdC. Higher cone voltage produces backbone fragmentation with complementary a(n)-base and w(m) ions close to the brominated base. On the basis of these observations, we located the brominated base in the sequence for all of the ODNs studied.     

Rationalization of an Unusual Solvent‐Induced Inversion of Enantiomeric Excess in Organocatalytic Selenylation of Aldehydes

An unusual solvent‐induced inversion of the sense of enantioselectivity observed in the α‐selenylation of aldehydes catalyzed by a diphenylprolinol silyl ether catalyst is correlated to the presence of intermediates formed subsequent to the highly selective C? Se bond‐forming step in the catalytic cycle. This work provides support for a mechanistic concept for enamine catalysis and includes a general role for “downstream intermediates” in selectivity outcomes in organocatalysis.     

Sol-Gel Thin Films of BaFe12O19 from Chemically Modified Alkoxide Precursors

Homogeneous BaFe₁₂O₁₉ (BaM) thin films have been prepared by the dip-coating technique on microscope slides and SiO₂ wafers using barium and iron alkoxides as precursors, and diethanolamine as a modifier. In order to optimise the coating conditions, the influence of the alkoxide, water and modifier on the sol viscosity, thickness and appearance of the Fe₂O₃ films has been investigated. For comparison of the crystallisation and magnetic properties, powders of the same composition as the films have been also prepared by the sol-gel method. The BaM phase appears after annealing at 650°C for 6 hours. The BaM film and powder, heated at 850°C for 6 hours, give coercive force of about 3000 and 5500 Oe, respectively.     

Benzaldehyde lyase catalyzed enantioselective self and cross condensation reactions of acetaldehyde derivatives

Flexible protected 1,3,4-trihydroxy-2-butanone is synthesized in high enantiomeric excesses by using asymmetric homo- and cross- acyloin coupling of aliphatic aldehydes catalyzed by benzaldehyde lyase.     

Separation of radium,thorium, uranium and plutonium on OSTION anion exchanger in atmospheric precipitation samples

An anion exchanger OSTION AT 0807 of Czechoslovak production was tested for the separation of radium, thorium, uranium and plutonium. According to the results, the separation process is suitable for analysis of atmospheric precipitation samples. Separation efficiency can be increased by the repetition of the procedures.     

Investigation of novel compounds via in silico approaches of EGFR inhibitors as anticancer agents

Before the experimental studies of a compound to be synthesized from in vitro to in vivo, it is possible to save both time and money with in silico approaches only with Computer Aided Drug Design (CADD) methods. In other words, compounds that can be new drug candidates can be suggested by drug design using computational drug discovery strategies. In this study, all molecules in the ChEMBL Database were virtual screened based on drugs with inhibitory properties on the Epidermal Growth Factor Receptor (EGFR), one of the receptor tyrosine kinases, which is effective in cancer cells. During this High-Throughput Screening (HTS), the number of compounds was minimized according to the parameters of the reference drugs, physicochemical properties such as logP, M.W., HBA, HDB, RosLip. As a result of in silico approaches and molecular docking analysis, ten compounds with the highest docking scores were determined and a model compound that could be a new drug candidate was proposed.     

Hyperfine interactions in magnetoelectric hexaferrite system

Nuclear magnetic resonance (NMR) in Y-hexaferrite system (Ba_1?xSr_x)₂Zn₂Fe₁₂O₂₂ was measured on both monocrystalline and polycrystalline samples at liquid helium temperature. Corresponding ab-initio calculation of the hyperfine parameters was also performed. The signal from ⁵⁷Fe was detected in the frequency interval 65–76 MHz, while NMR spectrum of ⁶⁷Zn nuclei occurs between 15 and 30 MHz. Due to the disorder in two tetrahedral sublattices occupied partly by Zn and partly by Fe, the NMR lines are broad and the spectra are poorly resolved. Comparison between the experimentally observed ⁶⁷Zn spectra and the spectra modelled using the calculated hyperfine parameters was made. It indicates that the spectra of ⁶⁷Zn can be used to determine the distribution of Zn and Fe between the two tetrahedral sublattices.