Use of the Spin-Trapping Method for the Study of Stable Radicals Produced in Solid Dihydrothymine

ESR spin-trapping method has been used for the study of radiation-induced radicals in· powdered dihydrothymine. Four approximately equal small proton couplings (AH\u27 = 0.35 mT), a larger proton coupling (AH = 0.195 mT) and a nitrogen coupling (AN = = 0.295 mT) are attributed to the nitroxide radical formed by reaction of the spin trap with 6-dihydrothymyl radical upon dissolving of dihydrothymine. In the pyrimidine bases of nucleic acid and a number of related compounds irradiated in solid state and dissolved, no signs of the trapped radicals were observed

Пять базовых упражнений для роста мышц

Рухи важкоатлета під час піднімання штанги великої ваги є дуже складними не тільки у зв’язку з особливостями м’язової діяльності, умовами її здійснення, але й через обмеження правилами змагань. Піднімання штанги максимальної ваги можливе тільки за раціонального розподілу зусиль під час виконання вправи, раціональної траєкторії піднімання штанги. Все це потребує добре відпрацьованої програми рухів. В даній статті розкривається питання про найбільш оптимальні умови прояву зусиль для піднімання штанги максимальної ваги.Motions of weight-lifter during raising of barbell of large weight are very difficult not only in connection with the features of muscular activity, terms of her realization but also through limiting to the rules of competitions. Raising of barbell of maximal weight is possible only at rational distribution of efforts during implementation of exercise, rational trajectory of raising of barbell. All of it needs the well exhaust program of motions. In this article a question opens up about the most optimal terms of display of efforts for raising of barbell of maximal weight.Движения тяжелоатлета во время поднятия штанги большого веса являются очень сложными не только в связи с особенностями мышечной деятельности, условиями ее осуществления, но и через ограничение правилами соревнований. Поднятие штанги максимального веса возможно только при рациональном распределении усилий во время выполнения упражнения, рациональной траектории поднятия штанги. Все это нуждается хорошо отработанной программы движений. В данной статье раскрывается вопрос о наиболее оптимальных условиях проявления усилий для поднятия штанги максимального веса

ECONOMIC EQUILIBRIUM AND MONETARY POLICY

The problem of economic equilibrium as a theoretical basis of monetary policy has been considered. It has been noted, that it is necessary to take into account the state of imbalance in the economy and the factors of market failure. The conclusion has been made, that it is important to focus on hybrid forms of monetary policy, which means the use of different combinations of target reference points. The need is implied from this for a more flexible approach to the formation of modern policy of the Bank of Russia, which would not absolutize the regime of inflation targeting

Slabo izražene pojave u epr spektru paramagnetičnog centra sličnog šupljini u citozin hidrokloridu

The fine phenomena in the EPR spectra of the hole-like paramagnetic centre formed in cytosine(thiocytosine)-HCl crystals upon irradiation are studied with EPR spectroscopy. The spin Hamiltonian including the electronic Zeeman term, hyperfine coupling, quadrupole coupling and the nuclear Zeeman term has been used in the second-order perturbation treatment for the interpretation of the experimental observations. It is shown that the quadrupolar term causes a detectable shift of the EPR lines and also induces the "forbidden\u27\u27 transitions. From the shift of the "allowed\u27\u27 transitions and the positions of the ``forbidden\u27\u27 transitions, the chlorine quadrupolar coupling tensor [P], has been determined.Proučavane su slabo izražene, neredovite pojave u EPR spektrima paramagnetičnog centra sličnog šupljini u ozračenim kristalima citozin hidroklorida s primjesama tiocitozina. Za objašnjenje ponašanja upotrijebljen je spinski Hamiltonijan koji se sastoji od elektronskog Zeemanovog člana, nuklearnog Zeemanovog člana, člana hiperfine i člana kvadrupolne sprege jezgre s elektronom. Pokazano je da kvadrupolni član koji potječe od klora ne samo unosi pomak EPR spektralnih linija, nego uzrokuje i pojavu dodatnih, “zabranjenih” prijelaza. Iz mjerenja slabo izraženih pomaka linija i položaja “zabranjenih” linija izračunat je kvadrupolni tenzor

Oxidation-induced Spin Probes in Low-density Lipoproteins

PBN trapping indicated the presence of at least two types of radicals induced in LDL upon slow oxidation, as observed with EPR spectroscopy. The EPR spectra are very similar to those of the spin probes or spin labels, which are routinely used in the studies of macromolecular systems and supramolecular assemblies. The parameters of the spectral line shapes, treated in two different theoretical models, did not provide conclusive evidence for the phase transition in the LDL particles, known to be present at about 25 °C. It is concluded that both types of trapped radicals, or at least one of them, are associated with the apolipoproteins, with the spin probe sticking into the lipid domain of phospholipids

Complexity of Some Interesting (Chemical) Graphs

Complexity of some interesting polycyclic graphs is expressed in terms of the corresponding spanning trees. Graphs considered were a selection of all connected graphs with four and five vertices, graphs composed of two parts, or more parts, connected by a single edge, the Petersen graph, the Blanuša graph, the Desargues-Levy graph and the Schlegel graph of buckminsterfullerene

Slabo izražene pojave u epr spektru paramagnetičnog centra sličnog šupljini u citozin hidrokloridu

The fine phenomena in the EPR spectra of the hole-like paramagnetic centre formed in cytosine(thiocytosine)-HCl crystals upon irradiation are studied with EPR spectroscopy. The spin Hamiltonian including the electronic Zeeman term, hyperfine coupling, quadrupole coupling and the nuclear Zeeman term has been used in the second-order perturbation treatment for the interpretation of the experimental observations. It is shown that the quadrupolar term causes a detectable shift of the EPR lines and also induces the "forbidden\u27\u27 transitions. From the shift of the "allowed\u27\u27 transitions and the positions of the ``forbidden\u27\u27 transitions, the chlorine quadrupolar coupling tensor [P], has been determined.Proučavane su slabo izražene, neredovite pojave u EPR spektrima paramagnetičnog centra sličnog šupljini u ozračenim kristalima citozin hidroklorida s primjesama tiocitozina. Za objašnjenje ponašanja upotrijebljen je spinski Hamiltonijan koji se sastoji od elektronskog Zeemanovog člana, nuklearnog Zeemanovog člana, člana hiperfine i člana kvadrupolne sprege jezgre s elektronom. Pokazano je da kvadrupolni član koji potječe od klora ne samo unosi pomak EPR spektralnih linija, nego uzrokuje i pojavu dodatnih, “zabranjenih” prijelaza. Iz mjerenja slabo izraženih pomaka linija i položaja “zabranjenih” linija izračunat je kvadrupolni tenzor

Interaction of High Density Lipoprotein with Nicotine – an IR and Raman Study

The direct interaction of high density lipoprotein (HDL) with nicotine, one of the major components of cigarette particulate matter, has been studied here at molecular level. Nicotine affects the vibration modes of HDL due to its embedment within the lipid monolayer. The changes in the positions and intensities of vibration bands in protein and lipid domain of the particle were studied by IR and Raman spectroscopy. Three types of samples were prepared: native HDL sample and two HDL samples with added nicotine. The molecular ratio of nicotine /phospholipids in two samples was 1: 12 and 1: 6. The same types of samples were prepared from liposomes containing phosphatidylcholine, and sphingomyelin with addition of cholesterol. Spectra of liposome samples were used for distinguishing and attribution of lipid bands in spectra of HDL samples, where the majority of changes were observed. The incorporation of nicotine into lipid monolayer induces changes in the lipid bands from the vibrations in acyl chains and head groups of phospholipids. The changes in vibration bands from particular amino acids\u27 residues confirm that nicotine molecule is located within lipid monolayer but close to lipid-protein interface

Structural and Oxidation Properties of Plasma Lipoproteins from Different Phenotypes: FT-IR and ESR Study

Subclasses of lipoproteins VLDL, LDL and HDL were isolated from plasma of two different phenotypes, A and B. Phenotype B is present in people with diabetes, atherosclerosis and higher risk for cardiovascular disease. Lipoproteins were studied by FT-IR spectroscopy to investigate conformational and structural differences reflected in spectra. Differences were observed in spectra of LDL and VLDL. In protein domain differences were observed in amide I band profile and discussed in terms of conformation¬al change of apo B-100 in small LDL and large VLDL particles. The changes in lipid bands from pheno¬type B are associated with differences in core composition and lipids\u27 ordering in monolayer. The study of slow oxidation was done by measuring the oxygen consumption in lipoprotein solutions. Oxidation was faster in HDL and VLDL from phenotype B, while for LDL it was similar for A and B samples and signif¬icantly faster than in other two lipoproteins. (doi: 10.5562/cca2236

ERP spektroskopija suprahiperfinog međudjelovanja bakarnog paramagnetskog centra u kristalima citozin monohidrata

The planar complex of Cu(II) with two cytosine bases was formed by gamma irradiation of the cytosine monohydrate crystal, containing copper impurities. The paramagnetic complex was probably formed by trapping the radiation-induced migrating holes by Cu(I), that is originally present in the crystal lattice. The structure of the complex was analyzed from the superhyperfine pattern of its EPR spectra. The experimentally evaluated tensor elements of the three 14N couplings and the observation of an additional proton coupling unequivocally confirm the structure. The ab initio B3LYP density functional method calculations are in good agreement with the experiments. Both experiments and the calculations demonstrate large spin delocalization in the cytosine ring plane.Gama ozračivanjem kristala citozin monohidrata, koji je sadržavao bakarne nečistoće, pripremali smo planarni kompleks Cu(II) s dvije citozinske baze. Paramagnetski se kompleks vjerojatno stvarao vezanjem zračenjem proizvedenih šupljina i Cu(I) koji je prvotno bio u kristalnoj rešetci. Proučavali smo strukturu kompleksa analizirajući suprahiperfinu strukturu njegovog EPR spektra. Eksperimentalno određeni elementi tenzora triju vezanja 14N i opažanje dodatnog protonskog vezanja pouzdano potvrđuju strukturu. Ab initio B3LYP računi metodom funkcionala gustoće u dobrom su slaganju s mjerenjima. Eksperimenti i računi pokazuju jaku delokalizaciju spina u ravnini citozinskog prstena