Quantitative phase analysis and microstructural characterization of urinary tract calculi with X-ray diffraction Rietveld analysis on a Caribbean island

2022 ◽  
Vol 55 (1) ◽  
Author(s):  
Jaimie Greasley ◽  
Shivan Goolcharan ◽  
Roger Andrews
Keyword(s):  
Uric Acid ◽  
Urinary Tract ◽  
Calcium Oxalate ◽  
Rietveld Refinement ◽  
Natural Extension ◽  
X Ray Diffraction ◽  
Stone Analysis ◽  
X Ray ◽  
Carbonated Apatite ◽  
Urinary Tract Calculi

In the twin-island state of Trinidad and Tobago, urinary stone analysis is not routinely performed. This study investigates, via powder X-ray diffraction, 52 urinary tract calculi collected from hospitals in Trinidad. Of these, 46 stones were analysed with Rietveld refinement for quantitative analysis and materials characterization. Refined unit-cell, microstructural and weight fraction parameters were obtained, with the last being used for stone classification. The results revealed seven distinct mineralogical phases of varying frequency: calcium oxalate monohydrate (COM, 58%), calcium oxalate dihydrate (COD, 23%), carbonated apatite (APA, 48%), brushite (BRU, 6%), struvite (STR, 42%), uric acid (UA, 23%) and ammonium acid urate (AAU, 19%). The average refined crystallite sizes were 1352 ± 90 Å (COM), 1921 ± 285 Å (COD), 83 ± 5 Å (APA), 1172 ± 9 Å (BRU), 1843 ± 138 Å (STR), 981 ± 87 Å (UA) and 292 ± 83 Å (AAU). Subsequently, 36.5% of stones were categorized as phosphates, 34.6% as oxalates, 13.5% as uric acid/urates and 15.4% as mixed compositions. The study findings highlight the importance of stone analysis as a necessary step towards disease management of local patients, and endorse the application of Rietveld refinement as a natural extension to diffraction-based kidney stone investigations.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

scholarly journals Can stone composition be predicted by plain X-ray and/or non-contrast CT? A study validated by X-ray diffraction analysis

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Mohamed Gadelmoula ◽  
Ahmed M. Moeen ◽  
Ahmed Elderwy ◽  
Mohamed S. Abdel-Kader ◽  
Ayman Elqady ◽  
...  
Keyword(s):  
Calcium Oxalate ◽  
Diffraction Analysis ◽  
Great Influence ◽  
Calcium Oxalate Monohydrate ◽  
Categorical Variables ◽  
Stone Analysis ◽  
Stone Composition ◽  
Cutoff Value ◽  
X Ray ◽  
Contrast Ct

Abstract Background The stone composition has a great influence on the outcome of its treatment. There are several tests to predict the composition of stones preoperatively and stone analysis postoperatively. Herein, we want to evaluate if the stone composition could be predicted from plain X-ray KUB (PKUB) and/or non-contrast CT (NCCT) validated by in vitro X-ray powder diffraction analysis (XRD). Methods Between April 2014 and March 2016, 100 cases with urinary tract stones were included in the study. The radio-opacity of the stones in PKUB, stone density by NCCT, and after stone extraction, XRD were performed. Statistical analysis for the results was performed using Chi-square and Fisher exact tests for categorical variables and Mann–Whitney U and Kruskal–Wallis H for the nonparametric variables. The receiver operating characteristic curve was constructed to determine the best cutoff value. Results This study included 74 males and 26 females with a median age of 32 years (range 2–70). Regarding the radio-opacity by PKUB, there were 30 stones dense opaque, 44 opaque, 21 faint opaque, and 5 radiolucent. XRD revealed 97 mixed and 3 pure stones. The calcium oxalate monohydrate (COM) stone composition could be predicted in dense opaque stone by PKUB in 75.9% and urate composition in the radiolucent stone by 40%. The cutoff value of HU density by NCCT to the dense opaque stones in the PKUB was > 1020 and for radiolucent stones was < 590. Conclusion Stone radio-opacity by PKUB and its attenuation value by NCCT could successfully predict its calcium oxalate monohydrate, struvite, and urate composition. However, the chemical stone analysis is still required as most stones are mixed.

scholarly journals Determination of amorphous matter in industrial minerals with X-ray diffraction using Rietveld refinement.

2020 ◽  
Vol 56 (1) ◽  
pp. 1
Author(s):  
George Christidis ◽  
Katerina Paipoutlidi ◽  
Ioannis Marantos ◽  
Vasileios Perdikatsis
Keyword(s):  
Particle Size ◽  
Rietveld Refinement ◽  
Raw Materials ◽  
Internal Standard ◽  
Absolute Error ◽  
Matter Content ◽  
Size Difference ◽  
X Ray Diffraction ◽  
X Ray ◽  
Amorphous Matter

A great variety of fine grained industrial rocks, which are valued by the industry contain variable amounts of amorphous or poorly crystalline matter, which is not easily detectable by the conventional mineralogical analysis methods based on X-ray diffraction (XRD). The quantification of amorphous matter in industrial rocks is a major task because it provides a thorough characterization of the raw materials and assists to interpret their reactivity. Among the most reliable methods used for quantification of amorphous matter, are those which are based on Rietveld refinement. In this study we prepared 1:1 mixtures of synthetic or natural calcite and quartz with 5-80% glass flour and added corundum (α-Al2O3) internal standard and applied the Autoquan2.80 © software based on the BGMN computer code to quantify the amorphous matter content. The mixtures with synthetic minerals yielded results with minimum absolute error due to the similar particle size of the minerals, the internal standard and the glass. By contrast, the mixtures with natural minerals displayed greater relative error due to the particle size difference between the minerals on the one hand and the internal standard and the glass on the other, due to the microabsorption effect. Moreover, preferred orientation was important in the case of natural calcite, due to perfect  cleavage plane. Mixtures containing up to 25% amorphous matter did not display the characteristic hump at 20-30 °2θ, suggesting that the lack of the hump is not a safe criterion for the recognition of amorphous matter.

scholarly journals Stone composition of renal stone formers from different global regions

2021 ◽  
Vol 93 (3) ◽  
pp. 307-312
Author(s):  
Adam Hali´nski ◽  
Kamran Hassan Bhatti ◽  
Luca Boeri ◽  
Jonathan Cloutier ◽  
Kaloyan Davidoff ◽  
...  
Keyword(s):  
Uric Acid ◽  
Calcium Phosphate ◽  
Calcium Oxalate ◽  
Urinary Stones ◽  
Ureteral Stones ◽  
Stone Analysis ◽  
Stone Composition ◽  
Stone Formers ◽  
Cystine Stones ◽  
Struvite Stones

Objective: To study urinary stone composition patterns in different populations around the world. Materials and methods: Data were collected by reviewing charts of 1204 adult patients of 10 countries with renal or ureteral stones (> 18 years) in whom a stone analysis was done and available. Any method of stone analysis was accepted, but the methodology had to be registered. Results: In total, we observed 710 (59%) patients with calcium oxalate, 31 (1%) with calcium phosphate, 161 (13%) with mixed calcium oxalate/calcium phosphate, 15 (1%) with carbapatite, 110 (9%) with uric acid, 7 (< 1%) with urate (ammonium or sodium), 100 (9%) with mixed with uric acid/ calcium oxalate, 56 (5%) with struvite and 14 (1%) with cystine stones. Calciumcontaining stones were the most common in all countries ranging from 43 to 91%. Oxalate stones were more common than phosphate or mixed phosphate/oxalate stones in most countries except Egypt and India. The rate of uric acid containing stones ranged from 4 to 34%, being higher in Egypt, India, Pakistan, Iraq, Poland and Bulgaria. Struvite stones occurred in less than 5% in all countries except India (23%) and Pakistan (16%). Cystine stones occurred in 1% of cases. Conclusions: The frequency of different types of urinary stones varies from country to country. Calcium-containing stones are prevalent in all countries. The frequency of uric acid containing stones seems to depend mainly on climatic factors, being higher in countries with desert or tropical climates. Dietary patterns can also lead to an increase in the frequency of uric acid containing stones in association with high obesity rates. Struvite stones are decreasing in most countries due to improved health conditions.

Disorders of renal calcium handling, urinary stones, and nephrocalcinosis

2020 ◽  
pp. 5093-5103
Author(s):  
Christopher Pugh ◽  
Elaine M. Worcester ◽  
Andrew P. Evan ◽  
Fredric L. Coe
Keyword(s):  
Uric Acid ◽  
Urinary Tract ◽  
Calcium Phosphate ◽  
Calcium Oxalate ◽  
Renal Colic ◽  
Ammonium Phosphate ◽  
Renal Stones ◽  
Magnesium Ammonium ◽  
Cystine Stones ◽  
Stone Passage

Renal stones are common, with a prevalence of 5 to 10% worldwide. Acute stone passage almost always produces the severe pain of renal colic, but stones are often asymptomatic and discovered incidentally on imaging. Prevalence of both symptomatic and asymptomatic disease appears to be rising, although the relative contributions of increasing use of more sensitive imaging modalities and real changes relating to diet and lifestyle are debated. The initial evaluation of patients with renal colic optimally includes noncontrast CT to accurately visualize the size and location of stones in the urinary tract. Initial management of stones less than 5 mm in diameter in patients without anatomical abnormalities of the urinary tract is to provide adequate analgesia coupled with α‎-blockade, followed by watchful waiting to allow time for stone passage. The presence of urinary tract infection, inability to take oral fluids, or obstruction of a single functioning kidney requires hospitalization and active management. Once the acute episode of stone passage or removal is over, thought should be given to diagnosis of the underlying causes and steps taken towards prevention. Since stone analysis is the cornerstone of diagnosis, the patient should be encouraged to collect any stones passed and retain them for analysis. Most stones (66–76%) are formed of calcium oxalate: other types include calcium phosphate (12–17%), uric acid (7–11%), struvite (magnesium ammonium phosphate, 2–3%), and cystine (1–2%). They form because urine becomes supersaturated with respect to the solute, and treatment to lower its concentration can prevent recurrence. This chapter describes the aetiology, pathogenesis, diagnosis and treatment of calcium oxalate stones, calcium phosphate stones, uric acid stones, struvite stones, cystine stones, and nephrocalcinosis.

Quality control in urinary stone analysis: results of 44 ring trials (1980–2001)

2005 ◽  
Vol 43 (3) ◽  
Author(s):  
Albrecht Hesse ◽  
Rolf Kruse ◽  
Wolf-Jochen Geilenkeuser ◽  
Matthias Schmidt
Keyword(s):  
Quality Control ◽  
Infrared Spectroscopy ◽  
Urinary Stone ◽  
Error Rates ◽  
The Body ◽  
X Ray Diffraction ◽  
Stone Analysis ◽  
Chemical Methods ◽  
X Ray ◽  
Pure Substances

AbstractUrinary stone analysis is the most important diagnostic step after stone removal from the body. The methods employed for these analyses are based on diverse analytical principles. Chemical methods are used for detecting individual ions. Infrared spectroscopy is used for examining molecular structures, and X-ray diffraction for determination of the crystalline structure of a substance. Since 1980, a twice-yearly ring trials quality control survey has been on offer to examine the quality of urinary stone analyses. A summary of the results of 44 ring trials (1980–2001) has been compiled for individual pure substances and binary (two-component) mixtures. On average, 100 laboratories have participated in these ring trials. Initially, over 80% of the participants carried out their analyses using chemical methods. In 2001, this figure decreased to a mere 13%. In contrast, a progressive increase in the use of infrared spectroscopy was observed, up to 79% of all participants employed this method. X-Ray diffraction was only employed in a small number of specialised laboratories (5–9%). The chemical methods produced a very high proportion of errors (6.5–94%) with both the pure substances and binary mixtures, whereas high error rates for infrared spectroscopy and X-ray diffraction were confined to individual substances only. Due to the poor results in the ring trials, the majority of laboratories stopped using chemical analysis, which is now considered to be obsolete. Regarding mixtures, error rates of over 10% also occurred with infrared spectroscopy and X-ray diffraction. Ring trials are indispensable for the quality management of urinary stone analysis.

SUBSTITUTION EFFECT IN Pr-DOPED YBCO

2006 ◽  
Vol 20 (20) ◽  
pp. 2899-2907
Author(s):  
L. ZHANG ◽  
M. WANG ◽  
Y. Y. XU
Keyword(s):  
Rietveld Refinement ◽  
Reference System ◽  
Structural Changes ◽  
Substitution Effect ◽  
Bond Valence ◽  
X Ray Diffraction ◽  
Dc Magnetization ◽  
X Ray ◽  
Bond Lengths ◽  
Bond Valence Sum

A series of samples of Y 1-x Pr x Ba 2 Cu 3 O y ( YPrBCO ) with 0.05 ≤ x ≤ 0.6 was synthesized and characterized by DC magnetization, X-ray diffraction (XRD), and Rietveld refinement. It is found that besides Pr substitution for Y , a part of Pr substituted for Ba in YBa 2 Cu 3 O y (YBCO), and the amount of Pr in the Y and Ba positions, respectively, is estimated by the refinement with the help of bond valence sum (BVS) calculation. By comparing the correlation of structural changes such as Ba-O (4) and Cu (1, 2)- O (4) bond lengths and superconductivity between our system with the reference system where Pr just replaces Y , structural evidences are found to explain Pr substitution for Ba suppresses Tc more strongly than that for Y .

scholarly journals Sol-Gel Synthesis, X-Ray Diffraction Studies, and Electric Conductivity of Sodium Europium Silicate

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ekaterina V. Borisova ◽  
Alexey V. Ignatov ◽  
Eugeni I. Get'man ◽  
Stanislav N. Loboda ◽  
Lyudmyla I. Ardanova ◽  
...  
Keyword(s):  
Activation Energy ◽  
Electric Conductivity ◽  
Rietveld Refinement ◽  
Sol Gel ◽  
Apatite Structure ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

Sodium europium silicate, NaEu9(SiO4)6O2, with apatite structure has been obtained and studied using X-ray diffraction and SEM. It has been shown that sodium sublimation does not take place upon synthesis by the sol-gel method. Rietveld refinement has revealed that sodium atoms are ordered and occupy the 4f position. O(4) atoms not related to silicate ions are placed at the centers of Eu(2) triangles. DC and AC electric conductivity and activation energy have been determined for the compound studied.

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