Metathesis of renewable unsaturated fatty acid esters catalysed by a phoban-indenylidene ruthenium catalyst

The phoban-indenylidene complex is a robust catalyst for self-metathesis and ethenolysis reactions of methyl oleate. The phoban-indenylidene catalyst was characterized by X-ray analysis, NMR and microanalysis and was used in various self-metathesis and ethenolysis of methyl oleate, giving rise to significantly higher end of run conversions compared to Grubbs 1st generation catalyst. These complexes are more stable and active than commercial Grubbs 1st generation catalyst, can be accessed from simple precursors and should give rise to more economical metathesis processes.     

Cadmium speciation in Arabidopsis thaliana as a strategy to study metal accumulation system in plants

The strategy to identify cadmium deactivation mechanism in Arabidopsis thaliana has been developed using selective and sensitive hyphenated techniques. Cadmium concentrations, in main parts of the plant, were determined by ICP-MS and total amount was found as 0.43-0.44 μg g⁻¹ in leaves and 3.3-3.4 μg g⁻¹ in roots. Speciation of the metal complexes in cells was investigated by SEC-ICP-MS in order to estimate the accumulation process. Phytochelatins, desglycyl-phytochelatins and phytochelatins homologues lacking the N-terminal γ-linked glutamic acid were extracted from plant and were identified by RPLC-ESI-MS. Two-dimensional chromatography allowed to link the metal complexes separated by SEC with isoforms of phytochelatins analyzed by high resolution RPLC and confirm their significant responsibility for metal accumulation. The potential of the cadmium complexes speciation indicates that obtained results could be reliable source of knowledge to confirm the information coming from the well-known genomic sequence of Arabidopsis and to estimate the role of γ-glutamyl transpeptidase in metabolism of glutathione.     

IMPAIRED REPAIR OF UVC-INDUCED DNA DAMAGE IN L5178Y-R CELLS: DNA UNWINDING STUDIES WITH THE USE OF 1-β-D-ARABINOFURANOSYL CYTOSINE

Abstract— L5178Y-R (LY-R) and L5178Y-S (LY-S) cells differ in sensitivity to UVC radiation (D₀: 2.8 and 9.0 J/m²respectively, for cells exposed in Fischer's medium). We used these cells and a DNA unwinding technique in conjunction with 1-β-D-arabinosyl cytosine to determine DNA strand breaks accumulating as a result of enzymatic incision during DNA repair. Following UVC exposure DNA strand break accumulation was observed in LY-S cells but not in LY-R cells. The repair defect in LY-R cells is accompanied by a delayed recovery of [³H]thymidine incorporation.     

邻、间、对-氯苯甲酸钠的NMR(1H,13C)和振动光谱

研究了邻、间、对 -氯苯甲酸钠并记录了这些化合物的 NMR和振动光谱。用能量合适的分子做了单点计算 ,确立了氯和钠对分子中电荷分布的影响 ,并对邻、间、对氯苯甲酸钠分别与苯甲酸钠以及邻、间、对氯苯甲酸做了比较。从各种不同的方法中得出的结论是相同的 ,且表明氯和钠影响了苯甲酸的芳香体系 ,氯和钠的影响特征取决于氯在环上的位置 ,并在碳原子上计算的形式电荷和它的化学位移之间提出相关性。     

The influence of selected metals and halogens on the electronic system of benzoic acid

The influence of halogens and metals on the electronic system of the aromatic ring in lithium, sodium and potassium complexes with p-halogenobenzoic acids has been investigated by means of ¹³C and ¹H NMR, IR and Raman spectroscopy and semi-empirical calculations. It has been shown that ionic potentials and electronegativities of halogens and metals are the main factors responsible for perturbations of the electronic charge distribution in the ring.     

Synthesis of (+)- and (−)-dihydropinidine by diastereoselective dimethylzinc promoted allylation of 2-methyltetrahydropyridine-N-oxide with an allylboronic ester

The enantiomers of the naturally occurring alkaloid dihydropinidine 1, potential antifeedants against the pine weevil, Hylobius abietis, were prepared by diastereoselective, dimethylzinc mediated addition of pinacolyl 2-propenylboronate 14 to nitrones (R)- and (S)-2-methyl tetrahydropyridine-N-oxide 3, prepared from d- and l-alanine, respectively.     

A note on acoustic decay measurements

Two sources of experimental errors in acoustic decay measurements are investigated: smoothing produced by the averaging device and “ringing” of the bandpass filter. Both linear and exponential averaging are considered. It is concluded that if it is only the average slope of the decay curve which is of interest, it suffices that the integration time of the detector is less than one quarter of the reverberation time of the system under test (with linear averaging), that the “reverberation time” of the detector is less than the half of the reverberation time of the system (with exponential averaging), and that the product of the filter bandwidth and the reverberation time of the system is at least 16. The requirements are much stronger if the important initial part of the decay is needed, however.     

Infrared spectra of lanthanide complexes with eriochrome cyanine r

An infrared spectroscopic study of the composition of these complexes in the solid state is described. Evaluation of the spectra made it possible to distinguish changes in the character of the lanthanide—ligand bonds in the series La — Lu, and to study the “double-double” effect.     

Industrial applications of electron beam flue gas treatment—From laboratory to the practice

The electron beam technology for flue gas treatment (EBFGT) has been developed in Japan in the early 1980s. Later on, this process was investigated in pilot scale in the USA, Germany, Japan, Poland, Bulgaria and China. The new engineering and process solutions have been developed during the past two decades. Finally industrial plants have been constructed in Poland and China. The high efficiency of SO_x and NO_x removal was achieved (up to 95% for SO_x and up to 70% for NO_x) and by-product is a high quality fertilizer. Since the power of accelerators applied in industrial installation is over 1 MW and requested operational availability of the plant is equal to 8500 h in year, it is a new challenge for radiation processing applications.