Thermalization of coupled atom-light states in the presence of optical collisions

The interaction of a two-level atomic ensemble with a quantized single mode electromagnetic field in the presence of optical collisions (OC) is investigated both theoretically and experimentally. The main accent is made on achieving thermal equilibrium for coupled atom-light states (in particular dressed states). We propose a model of atomic dressed state thermalization that accounts for the evolution of the pseudo-spin Bloch vector components and characterize the essential role of the spontaneous emission rate in the thermalization process. Our model shows that the time of thermalization of the coupled atom-light states strictly depends on the ratio of the detuning and the resonant Rabi frequency. The predicted time of thermalization is in the nanosecond domain and about ten times shorter than the natural lifetime at full optical power in our experiment. Experimentally we are investigating the interaction of the optical field with rubidium atoms in an ultra-high pressure buffer gas cell under the condition of large atom-field detuning comparable to the thermal energy in frequency units. In particular, an observed detuning dependence of the saturated lineshape is interpreted as evidence for thermal equilibrium of coupled atom-light states. A significant modification of sideband intensity weights is predicted and obtained in this case as well.Comment: 14 pages, 12 figures; the content was edite

The influence of coordinative tartrate and malatogermanate compounds on the activity of α-L-rhamnosidase preparations from Penicillium tardum, Eupenicillium erubescens and Cryptococcus albidus

Recently enzyme preparations of microbial origin become increasingly important in different industries. Preparations of α-L-rhamnosidase are used in the pharmaceutical industry as well as in scientific work as a tool for analytical research. We have obtained purified α-L-rhamnosidase preparations from Penicillium tardum, Eupenicillium erubescens and Cryptococcus albidus microorganism strains which are effective enzyme producers. The aim of the study was to estimate the ability of germanium coordination compounds to enhance enzyme catalytic activity. The effects of 11 heterometal mixed ligand tartrate (malate-)germanate compounds at 0.01 and 0.1% concentration on the activity of α-L-rhamnosidase preparations from Penicillium tardum IMV F-100074, Eupenicillium erubescens and Cryptococcus albidus 1001 were studied at 0.5 and 24 h exposition. The inhibitory effect of [Ni(bipy)3]4[{Ge2(OH)2(Tart)2}3Cl2]·15H2 on P. tardum α-L-rhamnosidase was revealed. All studied compounds except [CuCl(phen)2][Ge(OH)(HMal)2] were shown to increase activity of P. tardum α-L-rhamnosidase at a longer term of exposition. Activity of E. erubescens α-L-rhamnosidase was shown to be stimulated by d-metal cation-free compounds. C. albidus α-L-rhamnosidase occurred to be insensitive to all compounds studied

Study of volatile compounds of Сalendula officinalis L. flowers by the method of gas chromatography with MAS detection

A promising direction for improving the procedure of standardization of multicomponent phytoremedies is the use of so-called marker compounds, or markers – substances whose presence is characteristic only for individual medicinal raw materials. The introduction of methods of qualitative and quantitative analysis based on the use of markers is not only of great practical importance, but also of significant scientific expediency. One of the most common components used to make complex herbal collections are the flowers of medicinal plants, which are successfully used in medical practice both in the form of mono preparations and in the form of components of over-the-counter medicinal product of herbal origin. The pharmacological activity of the flowers of marigolds is due to the presence in their composition of a complex of biologically active substances, in particular essential oils, the content of which is associated with such pharmacological properties of the plant as bactericidal, antioxidant, etc. That is why it was considered expedient to search on markers for plant standardization in mixtures among essential oil components. The aim of the work was to study the components of the essential oil of calendula flowers (Calendula officinalis L.) by the method of gas chromatography with mass detection The object of the study was marigold flowers in packs of 50 g (CJSC «Liktravy», series 80310). The study of volatile components was carried out using the method of gas chromatography with mass detection. Chromatographic study of the studied extracts was carried out on an Agilent 6890 gas chromatograph equipped with a mass spectrometric detector (model 5973). The identification of the studied components was carried out by mass spectra and the retention time of the components. As a result of the conducted research, using library spectra, 59 volatile components were identified in the extract of the flowers of Calendula officinalis L., 50 were recognized: monocyclic and bicyclic monoterpenoids, sesquiterpenoids, sesquiterpene alcohols, etc. The major volatile components of flowers of Calendula officinalis L. are the following substances: α-cadinol, δ-cadinene, α-muurolol and epi-α-cadinol, the content of which is equal to 417.2 mg/kg, 284.2 mg/kg, 92.4 mg/kg and 75.7 mg/kg of raw material, respectively. The total content of all four major volatile compounds of the flowers of Calendula officinalis L. is 44.14% of the total amount of volatile compounds found in the object of research

UV continuum emission and diagnostics of hydrogen-containing non-equilibrium plasmas

For the first time the emission of the radiative dissociation continuum of the hydrogen molecule ($a^{3}\Sigma_{g}^{+} \to b^{3}\Sigma_{u}^{+}$ electronic transition) is proposed to be used as a source of information for the spectroscopic diagnostics of non-equilibrium plasmas. The detailed analysis of excitation-deactivation kinetics, rate constants of various collisional and radiative transitions and fitting procedures made it possible to develop two new methods of diagnostics of: (1) the ground $X^{1}\Sigma_{g}^{+}$ state vibrational temperature $T_{\text{vib}}$ from the relative intensity distribution, and (2) the rate of electron impact dissociation (d[\mbox{H_{2}}]/dt)_{\text{diss}} from the absolute intensity of the continuum. A known method of determination of $T_{\text{vib}}$ from relative intensities of Fulcher-$\alpha$ bands was seriously corrected and simplified due to the revision of $d \to a$ transition probabilities and cross sections of $d \gets X$ electron impact excitation. General considerations are illustrated with examples of experiments in pure hydrogen capillary-arc and H$_{2}$+Ar microwave discharges.Comment: REVTeX, 25 pages + 12 figures + 9 tables. Phys. Rev. E, eprint replaced because of resubmission to journal after referee's 2nd repor

Genomic characterization of chronic lymphocytic leukemia (CLL) in radiation-exposed Chornobyl cleanup workers

Background Chronic lymphocytic leukemia (CLL) was the predominant leukemia in a recent study of Chornobyl cleanup workers from Ukraine exposed to radiation (UR-CLL). Radiation risks of CLL significantly increased with increasing bone marrow radiation doses. Current analysis aimed to clarify whether the increased risks were due to radiation or to genetic mutations in the Ukrainian population. Methods A detailed characterization of the genomic landscape was performed in a unique sample of 16 UR-CLL patients and age- and sex-matched unexposed general population Ukrainian-CLL (UN-CLL) and Western-CLL (W-CLL) patients (n = 28 and 100, respectively). Results Mutations in telomere-maintenance pathway genes POT1 and ATM were more frequent in UR-CLL compared to UN-CLL and W-CLL (both p < 0.05). No significant enrichment in copy-number abnormalities at del13q14, del11q, del17p or trisomy12 was identified in UR-CLL compared to other groups. Type of work performed in the Chornobyl zone, age at exposure and at diagnosis, calendar time, and Rai stage were significant predictors of total genetic lesions (all p < 0.05). Tumor telomere length was significantly longer in UR-CLL than in UN-CLL (p = 0.009) and was associated with the POT1 mutation and survival. Conclusions No significant enrichment in copy-number abnormalities at CLL-associated genes was identified in UR-CLL compared to other groups. The novel associations between radiation exposure, telomere maintenance and CLL prognosis identified in this unique case series provide suggestive, though limited data and merit further investigation

DEGRADATION OF FLAVONOIDS BY Cryptococcus albidus α-L-RHAMNOSIDASE

The aim of the work was to investigate the possibility of practical use substrate specificity of α-Lrhamnosidase Cryptococcus albidus. p-Nitrophenyl derivatives of monosaccharides were used to determine the activity and specificity of the enzyme. The ability to hydrolyze of natural substrates was evaluated by Davis and high-performance liquid chromatography methods. It was shown that the enzyme exhibits narrow specificity towards the glycon of synthetic substrates and hydrolyzes only p-nitrophenyl-α-L-rhamnopyranoside (Km 4.5 mM) and p-nitrophenyl-α-D-glucopyranoside (Km 10.0 mM). C. albidus α-L-rhamnosidase the most active degrades naringin (Km 0.77 mM), releasing prunin and naringenin. Km for neohesperidin was 3.3 mM. The efficacy of the naringin hydrolysis in grapefruit and pomelo juice was 98 and 94% in 60 min (40 оC, 2 U/ml). As the result of treatment by α -L-rhamnosidase of green tea and orange juice, there was a decrease in the content of rutin, narirutin and hesperidin, indicating that the α -1,2- and α -1,6-linked rhamnose can be cleaved from natural flavonoids. Thus, the study shows the efficiency of treating citrus juices and green tea with C. albidus α -L-rhamnosidase for the purpose of improving their taste qualities and obtaining bioavailable flavonoids glucosides

Thermal stability of Cryptococcus albidus α-L-rhamnosidase

Yeast as well as micromycetes α-L-rhamnosidases, currently, are the most promising group of enzymes. Improving of the thermal stability of the enzyme preparation are especially important studies. Increase in stability and efficiency of substrate hydrolysis by α-L-rhamnosidase will improve the production technology of juices and wines. The aim of our study was to investigate the rate of naringin hydrolysis by α-L-rhamnosidase from Cryptococcus albidus, and also some aspects of the thermal denaturation and stabilization of this enzyme. We investigated two forms of α-L-rhamnosidase from C. albidus, which were obtained by cultivation of the producer on two carbon sources – naringin and rhamnose. A comparative study of properties and the process of thermal inactivation of α-L-rhamnosidases showed that the inducer of synthesis had no effect on the efficiency of naringin hydrolysis by the enzyme, but modified thermal stability of the protein molecule. Hydrophobic interactions and the cysteine residues are involved in maintaining of active conformation of the α-L-rhamnosidase molecule. Yeast α-L-rhamnosidase is also stabilized by 0.5% bovine serum albumin and 0.25% glutaraldehyde