S. Bhuloka Reddy

Trace elemental analysis of carcinoma kidney and stomach by PIXE method

Trace elemental analysis was carried out in the biological samples of carcinoma kidney and stomach using particle induced X-ray emission technique. A 2 MeV proton beam was employed to excite the samples. From the present results, the levels of elements K, Ca, Fe, Ni and Se are lower and those of the elements Ti, Co, Zn, As and Cd are higher in the cancer tissue of kidney than those observed in the normal tissue. In the case of stomach, the concentrations of elements Cl, K, Ca, Ti, Mn, Fe, Co, Cu and Zn are lower while concentrations of elements Cr, Ni, As and Br are higher in the cancer tissue of stomach than those observed in the normal tissue. The observed deficiency or excess of certain elements is correlated to carcinogenesis of that organ. The present results of carcinoma stomach support the previous observations that nickel and chromium are carcinogenic agents. The low levels of selenium observed in the carcinoma tissue of kidney and the low levels of manganese observed in the carcinoma tissue of stomach support the view that selenium and manganese inhibit the growth of cancer in kidney and stomach respectively. The observed high levels of zinc in the cancer tissue of kidney suggest that zinc is involved in the tumor growth and development of neoplastic transformation in kidney while the observed low levels of zinc in the carcinoma tissue of stomach suggest that zinc inhibits the growth of cancer in this organ. For correctly assessing the role played by the trace elements in initiating, promoting or inhibiting cancer in various organs, there is a need for acquisition of more data by trace elemental analysis from several investigations of this type undertaken in different regions.

Trace elemental analysis of cancer-afflicted intestine by PIXE technique

Trace elemental analysis was carried out in the biological samples of cancer-afflicted intestine using the particle-induced X-ray emission technique (PIXE). A 2-MeV proton beam was employed to excite the samples. From the present results, it can be seen that the concentration of the elements Cr, Fe, and Ni are higher in the cancerous tissue of the intestine than those observed in the normal tissue, whereas the concentration levels of the element Zn is slightly lower in the cancer tissue of intestine than that observed in the normal tissue. The concentrations of S, Cl, K, Ca, Ti, Mn, Co, and Cu in the cancer tissue of the intestine are in agreement with those observed in the normal tissues within standard deviations. The present results support the previous observations that Ni and Cr are carcinogenic agents. The observed slightly low levels of zinc in the cancer tissue of the intestine suggest that zinc could possibly inhibit the tumor growth and development of neoplastic transformation. For correctly assessing the role played by the trace elements in initiating, promoting, or inhibiting cancer in various organs, there is a need for the acquisition of more data by trace elemental analysis from several investigations of this type undertaken in different regions.

Trace elemental analysis of adenoma and carcinoma thyroid by PIXE method

Trace elemental analysis was carried out in the biological samples of normal, adenoma and carcinoma thyroids using particle induced X-ray emission technique (PIXE). A 2 MeV proton beam was employed to excite the samples. The elements Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, I, Hg and Pb were identified and their concentrations were estimated. The concentrations of the elements Ca, Cu, Zn, As, I and Hg are found to be much lower in carcinoma thyroid than those in the normal thyroid while the concentration of the elements K, Ti, V, Cr, Mn, Fe, Co and Sr in carcinoma thyroid are higher than the concentrations in normal thyroid. The lower and higher values of some of the elements in carcinoma thyroid may be attributed to some pathological factors.

Lα/Ll X-ray intensity ratios for elements in the region 55≤Z≤80

L alpha /Ll X-ray intensity ratios are measured in 19 elements in the region 55<or=Z<or=80. A 30 mCi 238Pu source is used to provide the excitation while a high-resolution Si(Li) detector connected to a 4 kbyte multichannel analyser and a microprocessor is used for the detection and measurement of X-ray intensities. The results show agreement with the theoretical predictions of Scofield (1969).

Kβ/Kα x-ray intensity ratios

Abstract The K β /K α X-ray intensity ratios in the elements Bi, Th and U were measured using a high resolution hyper pure germanium detector system. These results were combined with the values for Z between 20 and 82 as reported by the present authors and fitted to a polynomial. The fitted values are found to be in satisfactory agreement with the experimental values as well as with those due to Scofield. The most probable values of K β /K α are interpolated from the fit for several elements in the region of Z between 83 and 92.

Photoelectric cross-sections of light elements and compounds at low photon energies

Total photon mass attenuation coefficients in C, Al, S, Ti, B2O3, LiF, ZnO, Y2O3 and H8O2C5 (perspex) are measured on a good geometry set-up using proportional counter, Si(Li) and Ge(Li) detecting systems in the energy region from 6.47 to 52.014 keV employing x-rays and gamma rays from radioactive sources. The deduced photoelectric cross-sections are found to agree with the theoretical values of Storm and Israel, Scofield and semiexperimental values of Veigele wherever available within a few percent. The photo-electric cross-sections in elements, S, Ti and Y at their respectiveK-edges obtained by extrapolation technique agree with the theoretical values of Storm and Israel and Scofield at the respectiveK-edges except in S. In the case of S both the theoretical values atK-edges are found to be underestimations, more in the case of Scofield evaluations.

K β / K α X-ray intensity ratio following K -electron capture and radioisotope excitation

SummaryTheKβ/Kα X-ray intensity ratios are measured for Mn and Fe and for six other elements withZ lying in the range 49⩽Z⩽82 following electron capture decay and photon excitation using241Am and57Co sources. High-resolution Si(Li) and HpGe detector systems were used in the experiments. The dependence ofKβ/Kα values on the mode of excitation in the case of Mn and Fe is attributed to chemical effects, while no such dependence is found for the high-Z elements.RiassuntoSi misurano i rapportiKβ/Kα d’intensità dei raggi X per Mn e Fe e per altri 6 elementi aventiZ nell’intervallo 49⩽Z⩽82 che seguono il decadimento di cattura dell’elettrone e l’eccitazione fotonica usando le sorgenti231Am e57Co. Si usano negli esperimenti sistemi di rivelatori Si(Li) e HpGe ad alta risoluzione. Si attribuisce la dipendenza dei valori diKβ/Kα dal modo di eccitazione nel caso di Mn e Fe ad effetti chi mici, mentre non si trova una dipendenza di questo tipo negli elementi conZ grande.РеэюмеИэмеряются отнощенияKβ/Kα интенсивностей рентгеновского иэлу-чения для Мn и Fе и для щести других злементов сZ в области 49⩽Z⩽82 послеK-эахвата и фотонного воэбуждения, испольэуя источники241Am и57Co. В зкспери-ментах испольэуются системы детектирования с высоким раэрещением Si(Li) и НрСе. Зависимость величинKβ/Kα от моды воэбуждения в случае Мп и Ее при-писывается химическим зффектам, тогда как для злементов с больщимиZ такая эависимость не обнаружена.

K-electron capture probability in 167Tm

The K-electron capture probability in the decay of 167Tm for the first-forbidden transition 1/2+ to 3/2- was measured using the sum-coincidence method and employing a hyper-pure Ge system. The PK value is found to be 0.835+or-0.029, in agreement with the theoretical value of 0.829.

Gamma transitions and their relative intensities in153Eu

SummaryA careful search for the weak transitions in153Eu nucleus is made following the electron capture decay of153Gd with a high-resolution Si(Li) detector system. Two new transitions with energies 14.07 and 19.8 keV are observed. The energies and relative intensities of different gamma-rays are computed and given.RiassuntoUn’accurata ricerca delle transizioni deboli nel nucleo di153Eu si attua seguendo il decadimento di cattura dell’elettrone di153Gd con un sistema di rivelatore Si(Li) ad alta risoluzione. Si osservano due nuove transizioni con energie di 14.07 e 19.8 keV. Si calcolano e si forniscono le energie e le intensità relative dei diversi raggi gamma.РеэюмеИсследуются слабые переходы в ядрах153Eu и прослеживается злектронный распад153Gd, испольэуя детектор высокого раэрещения Si(Li). Обнаружены два новых перехода с знергиями 14.07 и 19.8 кзВ. Вычисляются знергии и относительные интенсивности раэличных гамма-лучей.

Kβ/Kα X-ray intensity ratios in elements with 20 ⩽ Z ⩽ 50

Abstract An accurate measurement of the Kβ/Kα ratios of X-ray intensities in elements with Z lying between 20 and 50 is undertaken using X-ray and radioactive source excitation methods. A high resolution Si(Li) detector spectrometer is used for the intensity measurements. The results show that the experimental values of Kβ/Kα for elements with Z above 40 are not consistent with the theoretical predictions due to Scofield. The experimental values are fitted to a polynomial and the Kβ/Kα values of elements not studied are interpolated using the polynomial fit.