17 research outputs found

    Density Matrix Functional Calculations for Matter in Strong Magnetic Fields: I. Atomic Properties

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    We report on a numerical study of the density matrix functional introduced by Lieb, Solovej and Yngvason for the investigation of heavy atoms in high magnetic fields. This functional describes {\em exactly} the quantum mechanical ground state of atoms and ions in the limit when the nuclear charge ZZ and the electron number NN tend to infinity with N/ZN/Z fixed, and the magnetic field BB tends to infinity in such a way that B/Z4/3→∞B/Z^{4/3}\to\infty. We have calculated electronic density profiles and ground state energies for values of the parameters that prevail on neutron star surfaces and compared them with results obtained by other methods. For iron at B=1012B=10^{12} G the ground state energy differs by less than 2 \% from the Hartree-Fock value. We have also studied the maximal negative ionization of heavy atoms in this model at various field strengths. In contrast to Thomas-Fermi type theories atoms can bind excess negative charge in the density matrix model. For iron at B=1012B=10^{12} G the maximal excess charge in this model corresponds to about one electron.Comment: Revtex, 13 pages with 6 eps figures include

    Female chromosome X mosaicism is age-related and preferentially affects the inactivated X chromosome

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    To investigate large structural clonal mosaicism of chromosome X, we analysed the SNP microarray intensity data of 38,303 women from cancer genome-wide association studies (20,878 cases and 17,425 controls) and detected 124 mosaic X events42Mb in 97 (0.25%) women. Here we show rates for X-chromosome mosaicism are four times higher than mean autosomal rates; X mosaic events more often include the entire chromosome and participants with X events more likely harbour autosomal mosaic events. X mosaicism frequency increases with age (0.11% in 50-year olds; 0.45% in 75-year olds), as reported for Y and autosomes. Methylation array analyses of 33 women with X mosaicism indicate events preferentially involve the inactive X chromosome. Our results provide further evidence that the sex chromosomes undergo mosaic events more frequently than autosomes, which could have implications for understanding the underlying mechanisms of mosaic events and their possible contribution to risk for chronic diseases

    Detectable clonal mosaicism and its relationship to aging and cancer

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    In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases

    Forensic odontology radiography and imaging in disaster victim identification:Positional statement of the members of the Disaster Victim Identification working group of the International Society of Forensic Radiology and Imaging

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    The use of radiography by forensic odontologists for the purposes of disaster victim identification (DVI) was established in 1949, when it was used to assist in the identification of the victims of the Great Lakes liner “Noronic” disaster in Toronto, Canada. Of the 119 victims of the disaster, positive identification matches were established for 24 of the most severely disfigured cases through the use of comparative odontology radiography (1-3). Today radiography is an established tool of forensic odontologists for DVI. The precise requirements for dental radiography for any given mass fatality incident will be determined by the working practices of the forensic odontologists engaged in the investigation

    Forensic Odontology Radiography and Imaging in Disaster Victim Identification Positional statement of the members of the Disaster Victim Identification working group of the International Society of Forensic Radiology and Imaging

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    The use of radiography by forensic odontologists for the purposes of disaster victim identification (DVI) was established in 1949, when it was used to assist in the identification of the victims of the Great Lakes liner “Noronic” disaster in Toronto, Canada. Of the 119 victims of the disaster, positive identification matches were established for 24 of the most severely disfigured cases through the use of comparative odontology radiography (1-3). Today radiography is an established tool of forensic odontologists for DVI. The precise requirements for dental radiography for any given mass fatality incident will be determined by the working practices of the forensic odontologists engaged in the investigation

    Occupational risk factors of lung cancer: a hospital based case-control study

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    OBJECTIVES: To investigate the relation between lung cancer and exposure to occupational carcinogens in a highly industrialised region in western Europe. METHODS: In a case-control study 478 cases and 536 controls, recruited from 10 hospitals in the Antwerp region, were interviewed. Cases were male patients with histologically confirmed lung cancer; controls were male patients without cancer or primary lung diseases. Data were collected by questionnaires to obtain information on occupations, exposures, and smoking history. Job titles were coded with the Office of Populations, Censuses and Surveys industrial classification. Exposure was assessed by self report and by job-task exposure matrix. Exposure odds ratios were calculated with logistic regression analysis adjusted for age, smoking history, and marital and socio-economic status. RESULTS: A job history in the categories manufacturing of transport equipment other than automobiles (for example, shipyard workers), transport support services (for example, dockers), and manufacturing of metal goods (for example, welders) was significantly associated with lung cancer (odds ratios (ORs) 2.3, 1.6, and 1.6 respectively). These associations were independent of smoking, education, civil, and economic status. Self reported exposure to potential carcinogens did not show significant associations with lung cancer, probably due to nondifferential misclassification. When assessed by job-task exposure matrix, exposure to molybdenum, mineral oils, and chromium were significantly associated with lung cancer. A strong association existed between smoking and lung cancer: OR of ex- smokers 4.2, OR of current smokers 14.5 v non-smokers. However, smoking did not confound the relation between occupational exposure and lung cancer. CONCLUSIONS: The study has shown a significant excess risk of lung cancer among workers in manufacturing of metal goods, manufacturing of transport equipment (other than automobiles), and transport support services. Assessment of exposure to specific carcinogens resulted in significant associations of chromium, mineral oils, and molybdenum with lung cancer. This study is, to our knowledge, the first study reporting a significant association between occupational exposure to molybdenum and lung cancer.
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