A new compound in kidney stones? Powder X-ray diffraction study of calcium glycinate trihydrate

Major and Trace Elements in Human Kidney Stones: A Preliminary Investigation in Beijing, China

Kidney stone disease affects people globally, with its prevalence on the rise. Given the importance of elements’ function in formation of kidney stones, this study investigated major and trace element content in thirty kidney stone samples from patients in Beijing. The kidney stone samples included inorganic components (calcium oxalate and carbonate apatite) and organic components (uric acid). Results showed that Ca is much higher in inorganic components than organic components. Compared to inorganic components, uric acid has a very low content of elements except for Cu and Se, which may be derived from the liver. Carbonate apatite stones have a higher element content (such as Na, K, Sr, Zn, Rb, Ba, Li, and Ti) than calcium oxalate stones, especially enrichment of Mg. The principal components analysis (PCA) extracted three principal components (PCs) with total variances of 91.91%, including the PC1 (45.08%): Na-Li-Ti-Ba-Sr-Zn, PC2 (30.05%): Rb, K, Mg, and PC3 (16.78%): Cu-Se, indicating that there are co-precipitated processes of these elements by their specific properties. A different distribution of stone types in the three components indicates a significant discrepancy in their element content, which can be an essential reference for patient intake elements.

Corrosion of Heritage Objects: Collagen-Like Triple Helix Found in the Calcium Acetate Hemihydrate Crystal Structure

Helical motifs are common in nature, for example, the DNA double or the collagen triple helix. In the latter proteins, the helical motif originates from glycine, the smallest amino acid, whose molecular confirmation is closely related to acetic acid. The combination of acetic acid with calcium and water, which are also omnipresent in nature, materializing as calcium acetate hemihydrate, was now revealed to exhibit a collagen‐like triple helix structure. This calcium salt is observed as efflorescence phase on calcareous heritage objects, like historic Mollusca shells, pottery or marble reliefs. In a model experiment pure calcium acetate hemihydrate was crystallized on the surface of a terracotta vessel. Calcium acetate hemihydrate crystallizes in a surprisingly large unit cell with a volume of 11,794.5(3) ų at ambient conditions. Acetate ions bridge neighboring calcium cations forming spiral chains, which are arranged in a triple helix motif.

The Shift_and_Fix procedure inEXPO: advances for solvingab initiocrystal structures by powder diffraction data

The Shift_and_Fix procedure is a new method which has been developed for improving the quality of a structure model obtained by theab initiosolution process from powder diffraction data. The main features of the new approach, which is fully automatic, are as follows: (a) the structure model usually attained at the end of the phasing process by direct methods is shifted partly and randomly; (b) a combination of Fourier map calculation and least-squares cycles has been designed for relocating the shifted atoms onto positions which can finally be moved onto the true ones by the standard model optimization approaches; (c) the Fourier map is calculated using coefficients which depend on the chemical content of the compound under study. When the figure of merit for selecting the best set of phases derived by direct methods does not work well, the ALLTRIALS strategy can be applied: it aims to investigate, automatically and sequentially, all the stored direct methods phasing sets and pick up the correct solution. The Shift_and_Fix method has been applied for improving the structure model calculated by each one of the phasing sets processed by ALLTRIALS. It has been implemented in the computer programEXPOand proved to be effective in providing a better ALLTRIALS outcome and increasing the probability of succeeding in theab initiopowder solution.

Kidney stone analysis techniques and the role of major and trace elements on their pathogenesis: a review

Kidney stone disease is a polygenic and multifactorial disorder with a worldwide distribution, and its incidence and prevalence are increasing. Although significant progress has been made in recent years towards identifying the specific factors that contribute to the formation of kidney stone, many questions on the pathogenesis of kidney stones remain partially or completely unanswered. However, none of the proposed mechanisms specifically consider the role(s) of the trace elements and, consequently, the contribution of trace constituents to the pathogenesis of kidney stones remains unclear and under debate. The findings of some studies seem to support a role for some major and trace elements in the initiation of stone crystallization, including as a nucleus or nidus for the formation of the stone or simply as a contaminant of the stone structure. Thus, the analysis of kidney stones is an important component of investigations on nephrolithiasis in order to understand the role of trace constituents in the formation of kidney stones and to formulate future strategies for the treatment and prevention of stone formation and its recurrence. The aim of this review is to compare and evaluate the methods/procedures commonly used in the analysis of urinary calculi. We also highlight the role of major and trace elements in the pathogenesis of kidney stones.