Quantitative energy-dispersive X-ray fluorescence analysis for unknown samples using full-spectrum least-squares regression

The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.

Quantification of Silicon (SI) and Silicon Dioxide (SiO2) from the Nafud Desert-Al-Qassim Region, Kingdom of Saudi Arabia Using XRD Analysis

This research was conducted in the Qassim region, Kingdom of Saudi Arabia. The goal of this research is to determine the percentage of silicon in the Rub al-Khali desert. Samples were collected from four cities located in the Al-Qassim Region of Saudi Arabia (Uyun Al-Jawa, Al-Fuwailiq, Al-Sulaibiya, and Al-Qawara), from three distinct depths (the earth’s surface, 50 cm, and 100 cm). The percentages of silicon in these places vary between the highest value for silicon dioxide, which is 74.47 m/m%, and 34.8 m/m% for silicon in Al-Qawara city at a depth of 100 cm. We used an x-ray fluorescence (XRF) instrument to evaluate the samples. There are high percentage of both silica and silicon in the Nafud desert. Studies have shown that these ratios can help investors benefit from an element of Silicon and silicon dioxide, so the sands of the Nafud desert is sufficient for extracting Silicon and silica in huge quantities. This may transform the Kingdom into a leading country in the global computer technology industry that depends on silicon extracted from the desert sands, the most important of which are microcomputer data processing devices.

Using Prostatic Fluid Levels of Some Trace Elements and Their Combinations in Non-Invasive and Highly Accurate Screening for Prostate Cancer

Objective: Prostate specific antigen (PSA) does not provide the high reliability and precision that is required for an accurate screening for prostate cancer?(PCa). The aim of our study was to search for a simple, rapid, direct, preferably non-invasive, and highly accurate biomarker and procedure for the screening for PCa. Method: The levels of trace elements (TE) Br, Fe, Rb, Sr,?and Zn were prospectively evaluated in expressed prostatic fluid (EPF). Also?Zn/Br, Zn/Fe, Zn/Rb, Zn/Sr concentration ratios as well as ZnRb and (ZnRb)/Fe concentration combinations were calculated for EPF samples, obtained from 38 apparently healthy males and from 33, 51, and 24 patients with chronic prostatitis, benign prostatic hyperplasia, and PCa, respectively. Measurements were performed using an energy dispersive X-ray fluorescent (EDXRF) microanalysis. Results: It was found that in the EPF of cancerous prostates the levels of Rb, Zn, Zn/Br, Zn/Fe, Zn/Sr, ZnRb, and (ZnRb)/Fe were significantly lower in comparison with those in the EPF of normal, inflamed, and hyperplastic prostates. For example, in comparison hyperplastic?with cancerous prostates p values obtained using Student’s t-test and?Wilcoxon-Mann-Whitney U-test were Conclusions: The levels of TE and their combinations in EPF, obtained by EDXRF, is a fast, reliable, andnon-invasive diagnostic tool that can be successfully used by local, non- urologist physicians at the point-of-care to provide a highly effective PCa screening and as an additional confirmatory test before a prostate gland biopsy.

Clustering analysis of ancient celadon based on SOM neural network

In the study, chemical compositions of 48 fragments of ancient ceramics excavated in 4 archaeological kiln sites which were located in 3 cities (Hangzhou, Cixi and Longquan in Zhejiang Province, China) have been examined by energy-dispersive X-ray fluorescence (EDXRF) technique. Then the method of SOM was introduced into the clustering analysis based on the major and minor element compositions of the bodies, the results manifested that 48 samples could be perfectly distributed into 3 locations, Hangzhou, Cixi and Longquan. Because the major and minor element compositions of two Royal Kilns were similar to each other, the classification accuracy over them was merely 76.92%. In view of this, the authors have made a SOM clustering analysis again based on the trace element compositions of the bodies, the classification accuracy rose to 84.61%. These results indicated that discrepancies in the trace element compositions of the bodies of the ancient ceramics excavated in two Royal Kiln sites were more distinct than those in the major and minor element compositions, which was in accordance with the fact. We argued that SOM could be employed in the clustering analysis of ancient ceramics.

Significance of trace element quantities in the prostatic secretion of patients with benign prostatic hyperplasia and prostate cancer

Aim:Benign prostatic hyperplasia and prostate cancer is an internationally important health problem of the man,particularly in developed countries.The aim of this exploratory study was to evaluate whether significant difference in the levels of Zn and some other trace elements of prostatic fluid exist between the inflamed and malignantly transformed prostate.Methods:Prostatic fluid levels of Br,Fe,Rb,Sr,and Zn were prospectively evaluated in 52 patients with benign prostatic hyperplasia and 24 patients with prostate cancer.Measurements were performed using 109Cd radionuclide-induced energy dispersive X-ray fluorescent microanalysis.Prostatic fluid samples were divided into two portions.One was used for cytological study to exclude prostatitis,while the other was intended for trace element analysis.Results:Mean values±standard error of means for concentration(mg/L)of trace element in the prostatic fluid of hyperplastic prostate were:Br 2.32±0.30,Fe 11.5±1.8,Rb 1.70±0.23,Sr 1.41±0.26,and Zn 488±42.The contents of Rb and Zn were significantly lower(approximately 3.2 and 7.7 times,respectively)in fluid of cancerous prostate compared with those in fluid of hyperplastic prostate.Conclusion:There are significant differences in trace element contents in the fluid of hyperplastic and malignantly transformed prostate.The great decrease in levels of Rb and Zn in the fluid of cancerous prostate might demonstrate ;an involvement of these trace elements in etiology and pathogenesis of malignant prostate tumors.It was supposed that the differences in Rb and Zn levels in prostatic fluid can be used as tumor markers.