Using S and Pb isotope ratios to trace leaching of toxic substances from an acid-impacted industrial-waste landfill (Pozdatky, Czech Republic).

Slightly elevated concentrations of toxic species in waters sampled in the surroundings of a leaky landfill may be both a sign of an approaching contaminant plume, or a result of water-rock interaction. Isotopes can be instrumental in distinguishing between anthropogenic and geogenic species in groundwater. We studied sulfur and lead isotope ratios at an abandoned industrial-waste landfill, located in a densely populated part of Central Europe.

Short- and long-term variability of radon progeny concentration in dwellings in the Czech Republic.

In this paper, repeated measurements of radon progeny concentration in dwellings in the Czech Republic are described. Two distinct data sets are available: one based on present measurements in 170 selected dwellings in the Central Bohemian Pluton with a primary measurement carried out in the 1990s and the other based on 1920 annual measurements in 960 single-family houses in the Czech Republic in 1992 and repeatedly in 1993. The analysis of variance model with random effects is applied to data to evaluate the variability of measurements.

OCO and NCO chelated derivatives of heavier group 15 elements. Study on possibility of cyclization reaction via intramolecular ether bond cleavage.

A set of four pincer ligands, either the OCO type ligands L(1-3) [2,6-(ROCH(2))(2)C(6)H(3)](-), where R = Me (L(1)), mesityl (L(2)), t-Bu (L(3)) or novel NCO ligand [2-(Me(2)NCH(2))-6-(t-BuOCH(2))C(6)H(3)](-) was studied. The reaction of L(4)Li with PCl(3) resulted in isolation of [2-(OCH(2))-6-(Me(2)NCH(2))C(6)H(3)]PCl (1) as a result of intramolecular ether bond cleavage and elimination of t-BuCl. The conversion between the organolithium compounds L(1,2,4)Li and AsCl(3) led to the desired chlorides, i.

Development and characterization of an aircraft aerosol time-of-flight mass spectrometer.

Vertical and horizontal profiles of atmospheric aerosols are necessary for understanding the impact of air pollution on regional and global climate. To gain further insight into the size-resolved chemistry of individual atmospheric particles, a smaller aerosol time-of-flight mass spectrometer (ATOFMS) with increased data acquisition capabilities was developed for aircraft-based studies. Compared to previous ATOFMS systems, the new instrument has a faster data acquisition rate with improved ion transmission and mass resolution, as well as reduced physical size and power consumption, all required advances for use in aircraft studies.

Real-time, single-particle measurements of oligomers in aged ambient aerosol particles.

Unique high mass negative ions in the -200 to -400 mass/charge range with repetitive spacings of 12, 14, and 16 units, representative of oligomeric species, have been detected in single ambient submicrometer aerosol particles using real-time single-particle mass spectrometry during the Study of Organic Aerosols field campaign conducted in Riverside, CA (SOAR) in August and November 2005. These oligomer-containing particles represented 33-40% of the total detected particles and contained other indicators of aging including oxidized organic carbon, amine, nitrate, and sulfate ion markers. Overall, the highest mass oligomeric patterns were observed in small acidic 140-200 nm particles in the summer.

17O NMR spectra of some organotin(IV) compounds containing O,C,O-chelating ligands.

The 17O chemical shifts of substituted benzyl ethers and a set of organotin(IV) derivatives containing O,C,O-chelating ligands were studied. Measured 17O chemical shifts were correlated with the additivity substituent increments for carbon atoms in the alkyl groups, and intramolecular Sn-O distance was obtained by X-ray diffraction techniques in the solid state.

Structural study of 2,6-bis[(dimethylaminomethyl)phenyl]butyl stannanes: nonconventional behaviour of triorganotin(IV) halides.

The four organotin (IV) compounds ([2,6-bis(dimethylaminomethyl)phenyl](n-butyl)R(1)R(2)stannane, with R(1)=R(2)=nBu (1), R(1)=nBu, R(2)=Cl (2), R(1)=nBu, R(2)=Br (3) and R(1)=R(2)=Br (4)), have been prepared and their structures have been investigated in various solvents and at various temperatures (NMR). The structures of these compounds in solution are solvent- and temperature-dependent. The solid state structures of 2 and 3 were studied using CP/MAS NMR spectroscopy and Xray diffraction techniques.

Radon survey in Kalamata (Greece).

A national radon survey is still lacking for Greece. Some groups have carried out several more or less local or extended radon surveys and valuable experience has been gained. After the first preliminary survey carried out by our group, where 500 Kodak LR-115 etched track detectors were placed in Greek schools and dwellings for one year, indoor radon measurements were continued by placing the same number of detectors in a restricted area, covering the city of Kalamata (a medium size city with 60,000 inhabitants), situated in the south of Peloponnese.

Study of lung cancer and residential radon in the Czech Republic.

Epidemiological evidence of lung cancer risk from radon is based mainly on studies of men employed underground in mines where exposures are relatively high in comparison to indoor exposure. Risk from residential radon can be estimated from occupational studies. Nevertheless, as such extrapolations depend on a number of assumptions, direct estimation of the risk is needed.

Radon exposure and lung cancer risk--Czech cohort study on residential radon.

Epidemiological evidence of lung cancer risk from radon is based mainly on studies of men employed underground in mines where exposures are relatively high in comparison to indoor exposure. Nevertheless, direct evidence of risk from residential radon is desirable. In 1990, a study was started comprising 12,000 inhabitants of an area with elevated radon concentrations.

(2,6-Bis[(dimethylamino)methyl]-phenyl-N(2),C(1),N(6))diphenyltin(II) bromide monohydrate.

In the title compound, [Sn(C(6)H(5))(2)(C(12)H(19)N(2))]Br.H(2)O, the Sn(IV) atom lies on a twofold axis and is coordinated by a C and two N atoms from the 2,6-bis[(dimethylamino)methyl]phenyl ligand in a tridentate fashion and by two phenyl groups. The resulting geometry is intermediate between square pyramidal and trigonal bipyramidal, with three C atoms in equatorial and the two N atoms in axial positions.

[Incidence of tick-borne encephalitis in the West Bohemia Region 1960-1999--evaluation of vaccination].

In 1960-1999 in the West Bohemian region 1216 cases of tick-borne encephalitis were recorded, four were fatal. Since 1992 there was a marked increase in the number of these infections--in 1992-1999 the relative morbidity was 6.7 per 100,000 population per year, the highest specific morbidity shifted to the age group of 55-64 years.

The detection of large HNO3-containing particles in the winter Arctic stratosphere.

Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These in situ observations were made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 kilometers) on several airborne sampling flights during a period of several weeks. With diameters of 10 to 20 micrometers, these sedimenting particles have significant potential to denitrify the lower stratosphere.

Short-wavelength far-infrared laser cavity yielding new lines in methanol.

We report 16 new laser lines generated in a short-wavelength far-infrared Fabry-Perot laser cavity. The CO(2) pump laser is coupled into the far-infrared laser outside the far-infrared laser mode, and the cavity uses a 45 degrees adjustable output coupling mirror; this combination results in a low-loss Fabry-Perot cavity for wavelengths below 150 microm. The new lines are of medium and strong intensity and have wavelengths in the region 26.

Bone and cartilage formation in diffusion chambers by subcultured cells derived from the periosteum.

Periosteal cells were enzymatically isolated from the tibiae of young chicks, introduced into cell culture, allowed to reach confluence, and subcultured. The freshly isolated or subcultured cells were loaded into diffusion chambers and implanted into the peritoneal cavity of athymic mice to test their osteo-chondrogenic potential in a contained in vivo location. Freshly isolated periosteal cells formed both bone and cartilage tissue in such test chambers, but with a relatively low incidence.

[Indications for and contribution of diagnostic arthroscopy of the knee joint].

The paper deals with indications and diagnostic possibilities of arthroscopy of the knee joint. The first part is devoted to the application of arthroscopy in the diagnosis of acute knee injuries. The Gillquists scheme of diagnostic procedure is outlined.