M. L. Garg

A Review, Bibliography, and Tabulation of K, L, and Higher Atomic Shell X‐Ray Fluorescence Yields

The K, L, and higher atomic shell x‐ray fluorescence yield measured data, covering the period 1978 to 1993, following the major previous compilations by Bambynek et al. (1972) and Krause (1979), are reviewed. An annotated bibliography of x‐ray fluorescence yield measurements, analyses, fits and tables 1978–1993 is presented. Comparisons of the fluorescence yields ωk, ωL, and ωM, based on measurements, and on theoretical models, are presented. Values of ωK, ωL, and ωM, fitted to standard empirical parametric formulations, are presented. In addition, selected well‐characterized measured ωK, ωL, and ωM results restricted to the period 1978–1993 are listed. These selected measured values are fitted by least squares to polynomials in Z of the form ∑nanZn and compared with theoretical and with earlier fitted values. A section on application of fluorescence yield data to computations of x‐ray energy‐absorption coefficients is included.

Measurements of L X-ray fluorescence cross sections and yields for elements in the atomic range 41 ≤ Z ≤ 52 at 5.96 keV

Abstract Total L X-ray fluorescence (XRF) cross sections have been measured for ten elements in the atomic range 41 ≤ Z ≤ 52 at 5.96 keV. It is observed that the measured L XRF cross-section values for the elements in this region are in general agreement with the theoretical ones evaluated using L Subshell fluorescent yields (ωi) and Coster-Kronig transition probabilities (ƒ ij ) based on the Relativistic Dirac-Hartree-Slater theory. The average L shell fluorescence yields ( ω L ) have also been computed using the presently measured cross-section values and the theoretical L shell photoionisation cross-section values.

Protective Effects of Zinc on Oxidative Stress Enzymes in Liver of Protein-Deficient Rats

Persons afflicted with protein malnutrition are generally deficient in a variety of essential micronutrients like zinc, copper, iron, and selenium, which in turn affects number of metabolic processes in the body. To evaluate the protective effects of zinc on the enzymes involved in oxidative stress induced in liver of protein-deficient rats, the current study was designed. Zinc sulfate at a dose level of 227mg/L zinc in drinking water was administered to female Sprague–Dawley normal control as well as protein-deficient rats for a total duration of 8 weeks. The effects of zinc treatment in conditions of protein deficiency were studied on rat liver antioxidant enzymes, which included catalase, glutathione peroxidase (GPx), glutathione reductase (GR), superoxide dismutase (SOD), glutathione reduced (GSH), and glutathione-S-transferase (GST). Protein deficiency in normal rats resulted in a significant increase in hepatic activities of catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase and the levels of lipid peroxidation. A significant inhibition in the levels of reduced glutathione and the enzyme activity of superoxide dismutase has been observed after protein deficiency in normal rats. Interestingly, Zn treatment to protein-deficient animals lowered already raised activity catalase, glutathione peroxidase, and glutathione-S-transferase and levels of lipid peroxidation to significant levels when compared to protein-deficient animals. Also, Zn treatment to the protein-deficient animals resulted in a significant elevation in the levels of GSH and SOD activity as compared to their respective controls, thereby indicating its effectiveness in regulating their levels in adverse conditions. It has also been observed that concentrations of zinc, copper, iron, and selenium were found to be decreased significantly in protein-deficient animals. However, the levels of these elements came back to within normal limits when zinc was administrated to protein-deficient rats. This study concludes that zinc has thepotential to regulate the activities of oxidative stress enzymes as well as essential hepatic elements.

Elemental composition and sources of air pollution in the city of Chandigarh, India, using EDXRF and PIXE techniques

Abstract The aerosol samples collected from industrial, commercial and relatively cleaner zones from the city of Chandigarh, India, have been characterized using EDXRF and PIXE techniques. Sample collection was done over different time periods during 1994–1996 using the Millipore sampling kit. Sixteen elements, namely, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Pb, were quantified in these samples. The loading distribution of aerosol on the filter media was assessed by scanning the sample along its diameter using proton beam. The elemental concentrations in all the samples analyzed by both the techniques have been corrected for this distribution. The elemental concentrations measured at different sites were used in absolute principle component analysis in order to identify the major sources affecting these sites and to apportion the measured air pollutants to these sources. Plausible sources identified from this analysis are soil dust, industrial activity, vehicular traffic and refuse burning. The soil dust accounts for the major fraction of the measured mass.

Impact of lead pollution on the status of other trace metals in blood and alterations in hepatic functions

Lead pollution and its impact on the status of four other trace elements—Fe, Zn, Br, and Rb—have been studied in the whole blood samples of different population groups employing energy dispersive X-ray fluorescence technique. These population groups included normal, automobile workers and lead battery manufacturers. The maximum increase in the concentration of trace elements in the blood samples of automobile workers and battery manufacturers was observed for Pb, when compared with normal Pb-B levels. The effect of lead pollution had significantly reduced Zn levels in automobile workers. Fe-B levels in automobile workers had been found to be reduced significantly as compared to control, whereas in battery workers the reduction was not significant. The concentration of Br was greatly enhanced in the blood samples of automobile workers, whereas Rb-B levels were significantly higher in both the automobile and battery workers. Oral administration of lead acetate (100 mg/kg body wt) to experimental rats significantly decreased the activities of hepatic transaminases after 3 and 4 mo of treatment, whereas the activity of hepatic alkaline phosphatase decreased significantly after 4 mo of treatment. It is concluded from this study that higher Pb-B levels greatly influence the levels of other trace elements in human blood samples and also the activities of hepatic transaminases as well as alkaline phosphatase in experimental rats.

PIXE analysis of ancient Indian coins

Abstract A number of coins of Hindu Shahis Dynasty of Kabul (990–1015 A.D.) have been analysed using proton induced X-ray emission (PIXE) technique. The 3 MeV proton beam from the Pelletron Accelerator at the Institute of Physics, Bhubaneswar, India was used for the production of X-rays. The X-rays were detected by Si(Li) detector ( FWHM=180 eV at 5.9 keV) placed at 90° to the beam direction. For the reliable calibration of the analytical system, thin foils of Micromatter standards of Fe, CuS, KCl, and RbNO 3 were used. The computer code GUPIX was employed to get concentration of trace elements in these coins. The elements Ca, Ti, Cr, Fe, Ni, Zn, As, Sb, Pb, and Bi were detected in these coins alongwith the major component of Cu and Ag. The coins were classified in two groups, coins no. 3, 9, 10, 11, 13, 14, 15, 16, 18, 19 as copper or billon coins having major component of copper, while coins no. 6, 17, 20, 21, 22 as silver coins having the major component of silver. The first group seems to belong to lower denomination while the other group belongs to higher denomination coins. There is a strong positive correlation between lead and zinc and also a strong negative correlation between copper and silver. The weight of coins varied between 3.05 and 3.39 gram. The comparison of our results with that of the ores of various mines indicates that the source of copper in these coins is from Khetri mine in Rajasthan. Silver seems to come from Afghanistan since it is not reported to occur as a primary mineral in ancient India.

Relative intensity measurements of L-shell X-rays for Ta, Au, Pb and Bi in the energy range 17-60 keV

The relative intensities of L-shell X-rays, I(Ll)/I(Lalpha ),I(Lbeta )/I(Lalpha ),I(Lgamma )/I(Lalpha ) for Ta, Au, Pb and Bi, have been measured at incident photon energies of 17.8, 25.8, 46.9 and 59.5 keV. The emitted X-rays were measured with a Si(Li) detector system. The results for Pb at 17.8, 25.8 and 46.9 keV and those for Ta and Bi at all the four energies are being reported for the first time. The experimental results are in reasonable agreement with theory.

Protective role of lithium during aluminium-induced neurotoxicity

The present study was designed to examine the protective potential of lithium if any in ameliorating the alterations induced by aluminium (Al) on behavioral and neurochemical indices. Al was given orally (100mg/kg b.wt./day) whereas lithium was administered through diet (1.1g/kg diet) to rats for a total duration of 2 months. Active and passive avoidance tests revealed significant alterations in the short-term memory and cognitive behavior in rats treated with Al. Further, locomotor as well as muscular activities were also found to be significantly affected. Co-administration of lithium with Al caused significant improvement in the short-term memory, cognition, anxiety, locomotion and muscular activity. Further, Al exposure led to a significant decrease in the acetylcholinesterase activity in both the cerebrum and cerebellum. Monoamine oxidase enzyme activity was significantly increased in cerebrum whereas a decrease was observed in cerebellum after Al treatment. Dopamine and serotonin levels were also found to be significantly decreased but the levels of reactive oxygen species were significantly increased in both the regions following Al treatment. Lithium supplementation to Al treated animals caused a significant improvement in the activities of enzymes acetylcholinesterase and monoamine oxidase which were altered by Al. Further, lithium when given along with Al was also able to regulate the levels of dopamine, serotonin and reactive oxygen species in both the regions and the values were found close to the normal controls. Ultrastructural studies revealed alteration in the structure of synapse after Al treatment. Therefore, the study strengthens the hypothesis that lithium can be used as a neuroprotectant during Al induced neurotoxicity.

Average l-shell fluorescence yields for elements 56 ⩽ Z ⩽ 92

Abstract The average L-shell fluorescence yields, \ gwL, have been evaluated for the elements with 56 ⩽ Z ⩽ 92 using our measured values of photon induced total L X-ray production cross-sections and Scofields (1973) theoretical total L shell photo-ionisation cross-sections. These values are compared with the values tabulated by earlier workers and with theoretical values based on relativistic Hartree-Dirac-Slater (RHDS) calculations [Chen et al. Phys. Rev. A24 (1981) 177]. A good agreement is found with the values based on RHDS calculations for the elements 56 ⩽ Z ⩽ 92.

Precision measurements of X- and gamma-ray intensities in 192Ir, 160Tb, 169Yb and 152Eu decays

Abstract The relative intensities of X-rays and gamma-rays in the decays of 192 Ir, 160 Tb, 169 Yb and 152 Eu have been measured with better precision using a coaxial 64.1 cm 3 high-purity Ge(HPGe) detector, a 28.27 mm 2 × 5.0 mm vertical plane HPGe detector and a 28.27 mm 2 × 5.5 mm vertical Si(Li) detectors. The intensities of different K and L X-rays in 160 Tb decay and different L X-rays in 152 Eu and 169 Yb decays are measured for the first time. This set of sources can be used for the efficiency calibration of semiconductor detectors over the energy range 5–1400 keV.