Current levels and distribution of 137Cs and Pu isotopes in soil on the Kazakhstan territory of the Kazakhstan-Chinese border: Semipalatinsk and Lob Nor nuclear test sites detonation

More than 100 soil samples were collected from 46 sites along roads and some settlements connecting Alma-Ata to Semipalatinsk City of the Kazakhstan-Chinese border and analyzed for ¹³⁷Cs and Pu isotopes (²³⁸Pu, ²³⁹Pu and ²⁴⁰Pu). The mean ¹³⁷Cs inventory at each site was within the range of 1,000-3,000 Bq/m² for most of the sites. The ^239,240Pu concentration and its inventories were observed in the wide range of 0.18-2.6 Bq/kg and 28-677 Bq/m², respectively. At the most northern sites in the areas studied, higher^239,240Pu inventories were found corresponding to the increase of ^239,240Pu fraction which was not leached by hot digestion with conc. HNO₃+H₂O₂. The ^239,240Pu/¹³⁷Cs activity ratios for the soil samples from the southern areas lie in the narrow range of 0.016–0.039 (most of data being 0.02–0.03), probably indicative of global fallout origin. On the other hand, a little or several higher ratios (0.05 to 0.22) were found for soil samples from the northern areas. These higher ratios demonstrate strongly that there was additional Pu input of local fallout due to the atomic explosions. From ²⁴⁰Pu/²³⁹Pu atomic ratios measured, contribution of local fallout ^239,240Pu, probably from the SNTS, was found to be higher (60–86%) in the sites around the northern areas than the southern ones. The present data might serve not only as a current baseline information on distribution and contamination levels of the long-lived fallout radionuclides in the Kazakhstan areas of the Kazakhstan-Chinese border, but also as a aid of selection of control area for epidemiological projects.     

Infrared reflection absorption spectroscopy of the sulfuric acid anion adsorbed on Pd(S)-[n(111) x (111)] electrodes

Adsorption of the sulfuric acid anion (HSO4- or SO42-) has been studied on Pd(S)-[n(111) x (111)] electrodes (n = 2, 3, 5, 9, 20, infinity) using in situ infrared reflection absorption spectroscopy (IRAS). A single band is observed around 1200 cm(-1) on all the electrodes. The band is assigned to the SO stretching vibration of the sulfuric acid anion adsorbed with three- or onefold geometry. This result differs from the case of Pt-stepped surfaces on which two IRAS bands are observed around 1200 and 1100 cm(-1). The maximum coverage of the sulfuric acid anion is enhanced with the increase of the terrace width. The surfaces with n more than 3 have similar IRAS band shifts (dv/dE). Pd-stepped surfaces, for which the terrace is wide enough for the anion adsorption, adsorb the anion on the terrace rather than the step.     

New diterpene pyrone-type compounds, metarhizins A and B, isolated from entomopathogenic fungus, Metarhizium flavoviride and their inhibitory effects on cellular proliferation

To date, entomopathogenic fungi have not been extensively examined by natural product chemists. In this study, we isolated novel pyrone diterpene-type compounds, metarhizins A (1) and B (2), from methanol extracts of entomopathogenic fungus, Metarhizium flavoviride. They showed potent and selective antiproliferative activity against both insect and human cancer cell lines. These results indicate that metarhizins A (1) and B (2) can be used as novel lead compounds for anti-cancer agents and probes for cell cycle regulation. To further investigate the structural requirements for this inhibitory activity, we synthesized many metarhizin derivatives and evaluated their antiproliferative activities.     

3+3]Cycloalkyne dimers linked by an azo group: a stable cis-azo compound forms polymeric aggregates by nonplanar pi-pi interactions

We previously reported that the structure of the linker moiety controlled intramolecular and bimolecular aggregation of [3+3]cycloalkyne oligomers, which are cyclic acetylene derivatives containing helicenes. Here, novel [3+3]cycloalkyne dimers linked by the azo group are synthesized, and aggregation behaviors are studied, which turned out to be considerably different. The trans- and cis-azo compounds were synthesized by the oxidative coupling of a [3+3]cycloalkyne amine derivative, and the stereochemistry was determined by UV-vis spectroscopy. 1H NMR, CD, gel permeation chromatography analysis, and vapor pressure osmometry in chloroform revealed that the trans-isomer forms a strong and selective bimolecular aggregate. The cis-isomer forms a trimolecular aggregate at a concentration below 1 mM and a polymeric aggregate at above 1 mM. Unlike known diaryl azo compounds, these azo isomers do not interconvert when subjected to heating or irradiation. In contrast, a model compound lacking the cyclic helicene structure isomerizes readily.     

Simultaneous determination of platinum(II) and palladium(II) by reversed phase high-performance liquid chromatography with spectrophotometric detection after collection on and elution from resin coated with dimethylglyoxal bis(4-phenyl-3-thisomicarbazone)

Amberlite XAD-7 resin coated with dimethylglyoxal bis(4-phenyl-3-thiosemicarbazone) (DMBS) was prepared and applied to the preconcentration of platinum(II) and palladium(II) from aqueous solution. Platinum(II) and palladium(II) were collected quantitatively on resin coated with the reagent (DMBS-XAD-7) from acidic solution in the presence of iodide ion by a bach method. The metal ions were then easily eluted from DMBS-XAD-7 as their DMBS chelates with a small volume of N,N-dimethylformamide. This collection and elution method was applied to the simultaneous determination of platinum(II) and palladium(II) by reversed-phase high-performance liquid chromatography with spectrophotometric detection using an ODS column and acetone-water as the mobile phase. The proposed method was applied to the determination of the metals in commercially available samples.     

Voltammetric detection of lectin using sugar labeled with electroactive substance.

The voltammetric detection of soybean agglutinin (SBA) was investigated on the basis of an interaction between the lectin and a sugar. Because galactose and lactose combined with SBA, the sugars were labeled by a Schiff base with an electroactive daunomycin. After the labeled sugar and SBA were mixed, measurements were carried out by voltammetry. When SBA-sugar binding occurs, a part of daunomycin of the labeled sugar is taken to the binding sites. As a result, SBA is detected by a change in the peak current of daunomycin, and the SBA-sugar interaction is evaluated. The length of the alkyl chain between daunomycin and the sugar was also considered. The electrode response to the concentration of SBA was linear over the range of 0.04-0.8 microg min(-1). The merits of this procedure are the convenient preparation of labeled sugar and a rapid measurement without separation. On the other hand, the detection of sugar at the 10(-9) mol dm(-3) level was achieved by a competitive reaction to limited binding sites of the lectin between the sugar and the labeled sugar.     

Observation of B-/+-->rho-/+rho0 decays

We report the first observation of the charmless vector-vector decay process B-/+-->rho(-/+)rho(0). The measurement uses a 78 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric e(+)e(-) collider operating at the Upsilon(4S) resonance. We obtain a branching fraction of B(B-/+-->rho(-/+)rho(0))=[31.7+/-7.1(stat)+3.8-6.7(syst)]x10(-6). An analysis of the rho helicity-angle distributions gives a longitudinal polarization fraction of Gamma(L)/Gamma=0.95+/-0.11(stat)+/-0.02(syst). We also measure the direct-CP-violating asymmetry A(CP)(B-/+-->rho(-/+)rho(0))=0.00+/-0.22(stat)+/-0.03(syst).     

Inclusive measurement of the photon energy spectrum in b --> sgamma decays

We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in the energy range 1.8 GeV < or = E*gamma < or = 2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b --> sgamma) = (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain (Egamma) = 2.292+/-0.026+/-0.034 GeV and (E2gamma) - (Egamma)2 = 0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic.     

Observation of a near-threshold D(0)D[over](0)pi(0) enhancement in B-->D(0)D[over](0)pi(0)Kappa decay

We report the first observation of a near-threshold enhancement in the D(0)D[over](0)pi(0) system from B-->D(0)D[over](0)pi(0)Kappa decays using a 414 fb(-1) data sample collected at the Upsilon(4S) resonance. The enhancement peaks at a mass M=3875.2+/-0.7(+0.3)/(-1.6) +/-0.8 MeV/c2 and the branching fraction for events in the peak is B(B-->D(0)D[over](0)pi(0)Kappa)=(1.22+/-0.31(+0.23)/(-0.30))x10(-4). The data were collected with the Belle detector at the KEKB energy-asymmetric e+ e- collider.     

Observation of new states decaying into Lambda(c)(+)Kappa(-)pi(+) and Lambda(c)(+)Kappa(0)/(s)pi(-)

We report the first observation of two charmed strange baryons that decay into Lambda(c)(+)Kappa(-)pi(+). The broader of the two states is measured to have a mass of 2978.5+/-2.1+/-2.0 MeV/c2 and a width of 43.5+/-7.5+/-7.0 MeV/c2. The mass and width of the narrow state are measured to be 3076.7+/-0.9+/-0.5 MeV/c;{2} and 6.2+/-1.2+/-0.8 MeV/c2, respectively. We also perform a search for the isospin partner states that decay into Lambda(c)(+)Kappa(0)/(s)pi(-) and observe a significant signal at the mass of 3082.8+/-1.8+/-1.5 MeV/c2. The data used for this analysis were accumulated at or near the Upsilon(4S) resonance, using the Belle detector at the e+ e- asymmetric-energy collider KEKB. The integrated luminosity of the data sample used is 461.5 fb(-1).