Advances in the histopathological characterization of breast tissue using combined X-ray fluorescence and X-ray diffraction data in a multivariate analysis approach

Previous studies have shown that the combination of X-ray fluorescence and X-ray diffraction data can be used as a histopathological characterization tool for breast tissue. Recent advances in energy-dispersive X-ray fluorescence techniques have allowed for benchtop systems to produce useful results in a reasonable time frame, allowing for clinical implementation to be realized. Using a polarized energy-dispersive X-ray fluorescence and energy-dispersive X-ray diffraction system optimized for measuring soft tissues, 38 breast tissue samples (19 normal and 19 diseased) were interrogated. The measured elemental concentrations and adipose and fibrous tissue contents were used in a principal component analysis study to determine the variables that produced the most differentiation between the normal and diseased tissues. For each sample, a soft independent modeling of class analogy technique was utilized to create classification models using the K, Fe, and Zn concentration and adipose and fibrous tissue content of all other breast samples. The class model produced from both X-ray fluorescence and X-ray diffraction data correctly classified 31 of 38 samples with no false positives or false negatives, showing improvement from solely X-ray fluorescence models or X-ray diffraction models alone, and demonstrates the usefulness of such a technique.     

XRF analysis of strontium: Exploring cellulose as a soft tissue equivalent

X-ray fluorescence (XRF) is a widely used method for in vivo elemental analysis. Particularly for bone, it is a non-invasive technique that provides information on composition without significant risk to the patient. XRF contributes a capability for measuring elements beneficial to human health, such as strontium. This is a proposed supplement that has been shown in clinical trials to reduce fracture risk in people diagnosed with osteoporosis. Although XRF is a viable method for quantifying bone strontium, there are still factors that constrain its effectiveness. X-ray attenuation through overlying soft tissue decreases the signal, consequently requiring correction before estimating the true concentration of strontium in bone. A correction factor can be applied to account for the reduced signal, but an accurate measurement of overlying soft tissue thickness is required. It has been shown that using the correlation between Compton peak count rate and overlying thickness can be used as an estimation of overlying tissue. Lucite is commonly used as a soft tissue substitute; however, its mean atomic number is appreciably lower than soft tissue, somewhat limiting its applicability. This study tests the feasibility of using cellulose filter papers as a substitute for overlying soft tissue to perform XRF analysis of strontium-doped hydroxyapatite bone phantoms. Mass attenuation coefficients are shown to be closer to those of soft tissue (International Commission on Radiation Units' four-component) than Lucite, and the Compton correlation is used to estimate thickness as a correction factor to quantify true strontium concentration.     

Classification and discrimination of some cosmetic face powders using XRF spectrometry with chemometric data analysis

Cosmetic foundation powders are one of the most commonly used cosmetic products in modern society. In recent years, the so‐called mineral‐based foundation products have become increasing popular in the cosmetic consumer market and can demand a premium price from the consumer. Manufacturers and suppliers often refer to mineral foundations as being ‘chemical free’, implying that these materials contain no potential skin irritants. However, there are no laws determining the use of the term ‘mineral cosmetic’ and interpretation of the use of the term is at the discretion of the manufacturer. In this study, wavelength‐dispersive X‐ray fluorescence spectrometry has been employed for multi‐elemental analysis of 39 mineral and traditional ingredient cosmetic powders. Quantitative measurements were obtained for Al, Bi, Ca, Fe, K, Mg, Si, Ti and Zn. Using cluster analysis and principal components analysis, we could clearly identify the samples as being of traditional or mineral formulation, and in the case of the mineral samples, specific manufacturers could be distinguished. Of the samples examined, samples from two suppliers marketed as mineral‐based were determined as being indistinguishable from traditional formulations. Copyright © 2012 John Wiley & Sons, Ltd.     

Quantitative characterisation of historic paper using THz spectroscopy and multivariate data analysis

THz spectroscopy in the time domain was explored in combination with multivariate data analysis, for quantitative determination of chemical and mechanical properties of historic paper, such as lignin content, tensile strength, and ash content. Using partial least squares (PLS) regression, it was shown that quantitative prediction of the material properties is possible, which indicates the potential of THz spectroscopy for chemical characterisation of complex organic materials of natural origin. In addition, the results demonstrate that THz spectra and PLS loading weights for lignin content differ significantly, which leads to the conclusion that THz spectra of composite macromolecular materials do not represent sums of spectra of the individual components. This supports the premise that THz spectra reflect intermolecular interactions. The study was carried out using 250 historical paper samples from the sixteenth century to present. Although the measurements were performed in vacuum to improve the quality of spectra, THz spectroscopy is in principle non-destructive. This research therefore reinforces the role of THz spectroscopy in characterisation of valuable historic materials, where invasive analysis is often not possible.     

利用ICP-AES测定农田生态系统微量元素Fe和Zn的循环率

通过长期定位试验和室内ICP-AES分析测试,探讨了下辽河平原不同施肥制度下农田生态系统微量元素Fe和Zn的输入情况,明晰了有机肥是农田输入Fe和Zn的主要途径。阐述了在没有垫圈土的情况下,投料经喂饲-堆腐过程的残留率为21.8%,低于有机物料施入土壤1年后的残留率(30%)。Zn通过喂饲-堆腐过程的循环率为71.9%,而Fe的循环率则为81.0%。     

Decomposition of in vivo spatially offset Raman spectroscopy data using multivariate analysis techniques

The decomposition of spatially offset Raman spectra for complex multilayer systems, such as biological tissues, requires advanced techniques such as multivariate analyses. Often, in such situations, the decomposition methods can reach their limits of accuracy well before the limits imposed by signal‐to‐noise ratios. Consequently, more effective reconstruction methods could yield more accurate results with the same data set. In this study we process spatially offset Raman spectroscopy (SORS) data with three different multivariate techniques (band‐target entropy minimization (BTEM), multivariate curve resolution and parallel factor analysis (PARAFAC)) and compare their performance when analysing a spectrally challenging plastic model system and an even more challenging problem, the analysis of human bone transcutaneously in vivo. For the in vivo measurements, PARAFAC's requirement of multidimensional orthogonal data is addressed by recording SORS spectra both at different spatial offsets and at different anatomical points, the latter providing added dimensionality through the variation of skin/soft tissue thickness. The BTEM and PARAFAC methods performed the best on the plastic system with the BTEM more faithfully reconstructing the major Raman bands and PARAFAC the smaller more heavily overlapped features. All three methods succeeded in reconstructing the bone spectrum from the transcutaneous data and gave good figures for the phosphate‐to‐carbonate ratio (within 2% of excised human tibia bone); the PARAFAC gave the most accurate figure for the mineral‐to‐collagen ratio (20% less than excised human tibia bone). Previous studies of excised bones have shown that certain bone diseases (such as osteoarthritis, osteoporosis and osteogenesis imperfecta) are accompanied by compositional abnormalities that can be detected with Raman spectroscopy, the utility of a technique which could reconstruct bone spectra accurately is manifest. The results have relevance on the use of SORS in general. © 2014 Crown copyright. Journal of Raman Spectroscopy published by John Wiley & Sons, Ltd.     

The use of X‐ray interaction data to differentiate malignant from normal breast tissue at surgical margins and biopsy analysis

X‐ray interaction data, including measuring bio‐metal levels and scattering characteristics, are being shown to be a possible discriminating variable in the classification of human tissues. However, a major concern when using X‐ray interaction data in breast cancer material is that the samples are rarely 100% tumour because of the invasive nature of the disease. The work reported here includes a methodology to help overcome this limitation as the experimental protocol includes mapping the data to histological analysis of the measured samples. This work has shown how important it is to relate the measured X‐ray parameters to the histology of the samples, particularly the clinical information that describes the percentage of tumour within each sample. Levels of K, Ca, Zn, Fe, Cu, Br and Rb were evaluated using X‐ray fluorescence and compared between tumour breast tissue and normal surrounding breast tissue. The coherent scattering properties of each sample were also examined using an angular dispersive X‐ray diffraction technique. Multivariate modelling using soft independent modelling of class analogy was used to classify samples kept out of the modelling procedure. A significant increase (p < 0.01) in the levels of Rb, Zn and K was found in the tumour samples. The levels of these elements show a correlation with the percentage of tumour reported to be present in a given sample. The results of classifying unknown tissue samples are presented using two‐class and three‐class models that help to reveal the importance of sample histology in studies involving breast cancers. Copyright © 2013 John Wiley & Sons, Ltd.     

利用ICP-AES测定农田生态系统微量元素Mn和Cu的循环率与收支

将长期定位试验和ICP-AES测试相结合,研究了不同施肥制度下农田生态系统微量元素Mn和Cu的循环和收支状况。结果表明,Mn和Cu因属沉积型循环其循环率高于80%,且随投料量增加呈增加趋势。两种微量元素均入不敷出,收支差额呈现M<(或≤)NPK+M相似文献   

消声器传递损失预测的边界元模态展开混合方法

将边界元法和解析方法结合形成一种混合方法用于计算消声器的传递损失,消声器被划分成若干个子结构,解析方法和边界元方法被分别用于计算规则结构和不规则结构的阻抗矩阵,不同子结构之间通过阻抗矩阵连接起来。为减少计算时间,采用一种基于模态配点法的简化方法。对单级膨胀腔、双级膨胀腔和穿孔管阻性消声器的传递损失进行了计算,混合方法计算结果与解析方法和三维数值方法计算结果吻合良好。分析了混合方法的计算效率并与传统子结构方法进行了比较,混合方法能明显节省计算时间。     

消声器传递损失预测的边界元模态展开混合方法

将边界元法和解析方法结合形成一种混合方法用于计算消声器的传递损失,消声器被划分成若干个子结构,解析方法和边界元方法被分别用于计算规则结构和不规则结构的阻抗矩阵,不同子结构之间通过阻抗矩阵连接起来。为减少计算时间,采用一种基于模态配点法的简化方法。对单级膨胀腔、双级膨胀腔和穿孔管阻性消声器的传递损失进行了计算,混合方法计算结果与解析方法和三维数值方法计算结果吻合良好。分析了混合方法的计算效率并与传统子结构方法进行了比较,混合方法能明显节省计算时间。     

New method development in prehistoric stone tool research: Evaluating use duration and data analysis protocols

Lithic microwear is a research field of prehistoric stone tool (lithic) analysis that has been developed with the aim to identify how stone tools were used. It has been shown that laser scanning confocal microscopy has the potential to be a useful quantitative tool in the study of prehistoric stone tool function. In this paper, two important lines of inquiry are investigated: (1) whether the texture of worn surfaces is constant under varying durations of tool use, and (2) the development of rapid objective data analysis protocols. This study reports on the attempt to further develop these areas of study and results in a better understanding of the complexities underlying the development of flexible analytical algorithms for surface analysis. The results show that when sampling is optimised, surface texture may be linked to contact material type, independent of use duration. Further research is needed to validate this finding and test an expanded range of contact materials. The use of automated analytical protocols has shown promise but is only reliable if sampling location and scale are defined. Results suggest that the sampling protocol reports on the degree of worn surface invasiveness, complicating the ability to investigate duration related textural characterisation.     

Measurement of spin correlation in tt production using a matrix element approach

We determine the fraction of tt events with spin correlation, assuming that the spin of the top quark is either correlated with the spin of the top antiquark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study tt spin correlation. We use tt → W+ b W- b → ?+ νb?- ν b final states produced in pp collisions at a center-of-mass energy sqrt(s)=1.96 TeV, where ? denotes an electron or a muon. The data correspond to an integrated luminosity of 5.4 fb(-1) and were collected with the D0 detector at the Fermilab Tevatron collider. The result agrees with the standard model prediction. We exclude the hypothesis that the spins of the tt are uncorrelated at the 97.7% C.L.     

Quantitative non‐destructive determination of trace elements in archaeological pottery using a portable beam stability‐controlled XRF spectrometer

A portable beam stability‐controlled XRF spectrometer developed at the LNS/INFN laboratories at Catania (Italy) was used for the non‐destructive determination of some trace elements (Rb, Sr, Y, Zr and Nb) in fine pottery artefacts. The XRF system and the method developed to control the energy and intensity stability of the excitation beam are briefly discussed. Concentrations of Rb, Sr, Y, Zr and Nb were determined in 50 fine potsherds from the votive deposit of San Francesco in Catania by using a multi‐linear regression method. Additionally, in order to test the homogeneity of the material composing the fine pottery samples, a small portion of a few potsherds was powdered and analysed using the XRF system and the multilinear regression method. A comparison between non‐destructive and destructive approaches is presented and discussed. Finally, quantitative XRF data were compared with those obtained by chemical analysis of the powdered samples. The results allowed the testing of a non‐destructive methodology to be used for the identification and grouping of the different typological classes of fine pottery mainly represented in the San Francesco sanctuary. Copyright © 2005 John Wiley & Sons, Ltd.     

The role of crystallographic angle in characterizing and modeling apatite fission-track length data

Recent experimental work on apatite fission-track length measurement has documented a number of factors that can exert a considerable influence on determinations of mean length. The principal source of length variation is anisotropy of annealing and etching behavior with respect to crystallographic angle. Procedural and environmental factors that influence which angular populations are preferentially sampled during measurement lead to variations in mean length that exceed standard statistical predictions. This paper evaluates the possibility of using c-axis projection to remove angular effects, and thus make length data more reproducible and informative.     

Determination of trace elements Fe,cu and Zn in the Algerian cancerous plasma using X-ray fluorescence (XRF)

Cancers are among the leading causes of morbidity and mortality in the world. The purpose of this study was to conduct a survey on the effect of minerals on cancer risk in the Algerian population. One hundred and seventy-eight plasma samples were used to analyze the concentrations of iron (Fe), copper (Cu), and zinc (Zn) in cancerous patients and also in healthy subjects using the X-ray florescence technique (XRF). Samples were classified according to the age and gender of the donors. An empirical formula was developed for the concentration of Zinc, Copper and Iron in cancer patients according to the age. The averages iron, copper and zinc concentrations in mg/kg for control and Cancer disease groups were (1493 ± 105; 1496 ± 86), (1172 ± 229; 1078 ± 283) and (1266 ± 202; 1344 ± 208) respectively. The ANOVA One-Way test was applied. For both genders of control and cancer disease groups it shows a significant decrease rate of copper for global and female gender and a significant increase rate of zinc for global and male gender (p < 0.05). The results indicate that the Cu and Zn concentration could show helpful tools for diagnosis and preventive treatment of cancer diseases.     

Multi-jet dynamics in lepton-induced reactions and calorimetry as a tool for analysis

It is discussed how calorimeters with a granular structure can be used quite efficiently to probe the hadronic final state in lepton induced reactions for the existence of a hierarchy of jet-like events: 2 jets, 3 jets etc. Predictions for the energy spectrum derived in a perturbative treatment of QCD to lowest non-trivial order are presented. By this method one can also isolate the effect of intrinsic p_⊥ of partons inside the nucleon from p_⊥ which is generated in the scattering process via hard gluon bremsstrahlung.     

Simpler methods do it better: Success of Recurrence Quantification Analysis as a general purpose data analysis tool

Over the last decade, Recurrence Quantification Analysis (RQA) has become a new standard tool in the toolbox of nonlinear methodologies. In this Letter we trace the history and utility of this powerful tool and cite some common applications. RQA continues to wend its way into numerous and diverse fields of study.     

NaNe potentials from a combined analysis of spectroscopic and scattering data

Experimental differential cross sections for the optical collision process Na(3s)+Ne+hν→Na(3p)+Ne and spectroscopic data for A²Π→X²Σ⁺optical transitions are used to obtain the potential curves for the X²Σ⁺ground and A²Π first excited states of the NaNe molecule and the spin-orbit function g_so(r).