Electronic properties of PbCl2 and PbBr2 using Compton scattering technique

We present the electron momentum densities of PbCl₂ and PbBr₂ using 661.65 keV γ-rays from 20 Ci ¹³⁷Cs source. To supplement our experimental investigations, we also report energy bands, density of states, Mulliken's population and Compton profiles of PbCl₂ and PbBr₂ using linear combination of atomic orbitals within Hartree–Fock and density functional theories. The energy bands are also computed employing full potential linearized augmented plane wave (FP-LAPW) method. Compton profiles are also analyzed in terms of equal-valence-electron-density scale. It shows that PbCl₂ is more covalent than PbBr₂, which is in agreement with the Mulliken's population analysis. It is seen that the Hartree–Fock and density functional theory based Compton line shapes show similar type of deviations from the experimental data. The luminescence properties of these halides are explained on the basis of energy band and density of states.     

Risk behaviors and its association with caries activity and dental caries in Japanese children

The aim of this study was to assess risk behaviors and its association with caries activity and dental caries in Japanese children. The subjects were 392 young Japanese children who underwent dental health check-up at 18, 30 and 42 months of age. Oral examinations, Cariostat tests and dental health questionnaires were carried out at each time. The caries prevalence of children was 1.5% at 18 months, 9.9% at 30 months and 28.1% at 42 months. Caries activity based on the Cariostat scores of children was correlated with caries status (caries-free/carious) at 42 months. In children with caries during each examination period at 42 months, eating snacks while playing was ranked as the most important behavioral risk (P < 0.001), followed by breast-feeding (P < 0.01), non setting of time for snacks (P < 0.05) and frequency of snacks (P < 0.05) at 18 months old; non brushing by mother (P < 0.05) and eating snacks while playing (P < 0.05) were ranked highest at 30 months old. In addition, eating snacks while playing (P < 0.001) at 42 months old was the only a significant factor for children with caries. Caries activity and risk behaviors were associated with caries experience at different age periods of childhood.     

Magnetic Resonance Imaging of the Breast: Current Practice and Future Developments

Over the past decade, there has been a dramatic increase in the use of magnetic resonance imaging (MRI) of the breast. MRI has proven to be a key tool in the detection and diagnosis of breast cancer and it plays a very important role in the evaluation of response to therapy. Breast MRI is highly sensitive and is able to detect lesions, which are occult on mammography and ultrasound. With the introduction of contrast agents, advances in surface coil technology and focused work in optimal scan protocols, breast MRI has continued to evolve as a valuable adjunctive breast imaging tool. This review will give a summary of current criteria and techniques that may be used in the detection, diagnosis and excision of breast lesions.     

Cytotoxic lipid esters from Peucedanum ledebourielloides

Two cancer cell growth inhibitory esters, 1,2-dipalmitoyl-3-glucosyl glycerol (1) and 1,6-dihydroxy-hexane-bis-palmitoyl ester (2), together with arachidic acid-2-hydroxy-glycerol ester, daucosterol, and oleanolic acid, were isolated from the roots of Peucedanum ledebourielloides (Apiaceae family). The structures were determined by spectroscopic analyses. The esters 1 and 2 displayed significant activity against the SGC-7901, HT-29, and HL-60 cancer cell lines.     

Spatial,temporal and host factors structure the Ceratomyxa shasta (Myxozoa) population in the Klamath River basin

The myxozoan parasite Ceratomyxa shasta is a virulent pathogen of salmonid fish in the Klamath River, Oregon/California, USA. We previously defined four principal genotypes of the parasite (O, I, II, III) based on a trinucleotide repeat (ATC)_0–3 in Internal Transcribed Spacer region 1 sequences. Genotypes occur in sympatry and show marked host preference: I in Chinook salmon (Oncorhynchus tschawytscha) and II in non-native rainbow trout (O. mykiss). In the present study, we sequenced the parasite from river water samples collected in May, June and September at three localities below, above and between the Klamath's five dams. We also sampled adult and juvenile coho salmon (O. kisutch), steelhead trout (O. mykiss, anadromous form) and native redband rainbow trout (O. mykiss, freshwater form) and additional Chinook salmon and non-native rainbow trout. We found that the C. shasta population was highly structured spatially, temporally and with respect to fish host species. Genotype O was present in water throughout the basin but detected almost exclusively in steelhead and native rainbow trout. Genotype I was in water only below the dams and detected only in Chinook salmon. Genotype II was detected in coho salmon below the dams, and in non-native rainbow trout exposed both above and below the dams. The same genotypes were detected in adult and juvenile fish of the same species. These findings have major implications for the design of effective surveillance and control programs for this economically and ecologically important fish parasite.     

Effects of smoking and drinking on excretion of hippuric acid among toluene-exposed workers

Summary In order to investigate possible effects of smoking and drinking on the metabolism of toluence in occupational settings, 206 toluene-exposed men (mean age: 31.4 years) in shoemaking, painting, or surface-coating workshops together with 246 nonexposed control men (36.8 years) were studied for the time-weighted average intensities of exposure to toluene, hippuric acid concentration in shift-end urine samples, and the two social habits of smoking and drinking. The mean daily consumptions of cigarettes and ethanol were about 20 pieces and 10 g among smokers and drinkers, respectively. The geometric mean toluene concentration among the exposed subjects was about 20 ppm, with a maximum of 521 ppm. Regression analysis after classification of the subjects by smoking and drinking clearly demonstrated that the two social habits, when combined, markedly reduce the hippuric acid level in the urine of workers exposed to was a significant association between smoking and drinking habits, which hindered separate evaluation of the effects of the two habits on toluene metabolism. Comparison of the present results with the findings reported in the literature, however, suggested that the observed effects may be attributable to smoking rather than to drinking habits.