Scanning electron microscopy and molecular modeling of inhibition of calcium oxalate monohydrate crystal growth by citrate and phosphocitrate

1995 ◽  
Vol 56 (4) ◽  
pp. 297-304 ◽  
Author(s):  
A. Wierzbicki ◽  
C. S. Sikes ◽  
J. D. Sallis ◽  
J. D. Madura ◽  
E. D. Stevens ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crystal Growth ◽  
Molecular Modeling ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Scanning Electron

Oxalate nephrosis in Macaca fascicularis

1994 ◽  
Vol 28 (3) ◽  
pp. 265-269 ◽  
Author(s):  
P. N. Skelton-Stroud ◽  
J. R. Glaister
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Macaca Fascicularis ◽  
Calcium Oxalate Monohydrate ◽  
Physical Structure ◽  
Cynomolgus Monkeys ◽  
X Ray ◽  
Convoluted Tubules ◽  
Scanning Electron

Crystals within the renal proximal convoluted tubules of several cynomolgus monkeys ( Macaca fasciculata) were investigated by light and scanning electron microscopy together with histochemistry and X-ray microanalysis techniques. The crystals were shown to have the physical structure and staining characteristics of calcium oxalate monohydrate. The incidence varied between different batches of animals and no definite cause was established.

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.

Examination of whewellite kidney stones by scanning electron microscopy and powder neutron diffraction techniques

2009 ◽  
Vol 42 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Michel Daudon ◽  
Dominique Bazin ◽  
Gilles André ◽  
Paul Jungers ◽  
Alain Cousson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Neutron Diffraction ◽  
Kidney Stones ◽  
Structural Characteristics ◽  
Calcium Oxalate Monohydrate ◽  
Atomic Scale ◽  
Mesoscopic Scale ◽  
Powder Neutron Diffraction ◽  
Scanning Electron

Kidney stones made of whewellite,i.e.calcium oxalate monohydrate, exhibit various morphological aspects. The crystalline structure of whewellite at the atomic scale was revisited through a single-crystal neutron study at room temperature using a four-circle automated diffractometer. The possible relationships between the various morphological types of whewellite stones and their structural characteristics were examined at the mesoscopic scale by the use of scanning electron microscopy and at the nanometric scale by powder neutron diffraction. All types of whewellite stones displayed a similar structure at the nanometric scale. However, significant differences were found at the mesoscopic scale. In particular, the crystallites in kidney stones resulting from a genetic hyperoxaluria exhibited a peculiar structure. There was a close relationship between stone morphology and crystallite organization at the mesoscopic level and the effectiveness of extracorporeal shockwave lithotripsy.

Epitaxial Relationships in Urolithiasis: The Brushite—Whewellite System

1977 ◽  
Vol 52 (2) ◽  
pp. 143-148 ◽  
Author(s):  
J. L. Meyer ◽  
J. H. Bergert ◽  
L. H. Smith
Keyword(s):  
Crystal Growth ◽  
Calcium Oxalate ◽  
Calcium Oxalate Monohydrate ◽  
Supersaturated Solution ◽  
Scanning Electron Micrographs ◽  
Phosphate Dihydrate ◽  
Acid Environment ◽  
Time Required ◽  
Insight Into ◽  
Scanning Electron

1. Whewellite (calcium oxalate monohydrate) crystals were found to induce epitaxially the heterogeneous nucleation of brushite (calcium monohydrogen phosphate dihydrate) from its metastable supersaturated solution in approximately one-quarter of the time required for spontaneous precipitation in the absence of added nucleating agents. Scanning electron-microscope observation of the crystalline phase showed brushite crystals originating from the whewellite seed crystals. 2. Crystal growth, upon nucleation, proceeded rapidly, and the metastable solutions quickly approached saturation. 3. Brushite crystals also induced the precipitation of calcium oxalate crystals in about one-quarter of the time required for spontaneous precipitation; however, the rate of crystal growth was considerably slower. In support of the chemical data, scanning electron micrographs showed few crystals of calcium oxalate nucleated on the surface of the brushite seed. 4. The results provide some insight into the cause of stones containing calcium oxalate or calcium phosphate (or both), which form in the normally acid environment of human urine.

Developmental morphology of the flower of Anthurium jenmanii: a new element in our understanding of basal Araceae

Botany ◽  
2008 ◽  
Vol 86 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Denis Barabé ◽  
Christian Lacroix
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Floral Development ◽  
Developmental Morphology ◽  
Calcium Oxalate Crystals ◽  
Stages Of Development ◽  
Early Stages ◽  
Floral Primordia ◽  
Scanning Electron

The early stages of development of the inflorescence of Anthurium jenmanii Engl. were examined using scanning electron microscopy. The inflorescence of A. jenmanii consists of more than 100 flowers arranged in recognizable spirals. Each flower has four broad tepals enclosing four stamens that are not visible prior to anthesis. The gynoecium consists of two carpels. The floral primordia are first initiated on the lower portion of the inflorescence, they then increase in size and appear as transversely extended bulges. The two lateral tepals are the first organs to be initiated, followed shortly thereafter by the two median tepals. The two lateral stamens are initiated first, directly opposite the lateral tepals, and are followed by two median stamens initiated directly opposite the median tepals. A two-lobed stigma is clearly visible during the early stages of development of the gynoecium. On some of the young inflorescences, all floral parts were covered by extracellular calcium oxalate crystals. The release of these prismatic crystals occurs before the stamens and petals have reached maturity. The mode of floral development observed in Anthurium has similarities with that reported for Gymnostachys . However, contrary to Gymnostachys, the development of the flower of A. jenmanii is not unidirectional.

Facile Synthesis of LnPO4: Tb (Ln = Ce, Gd) Green Emission Phosphors at Specific Temperature (80 or 680°С)

2012 ◽  
Vol 442 ◽  
pp. 3-7
Author(s):  
Qian Ming Wang ◽  
Zheng Yang Zhang ◽  
Yan Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crystal Growth ◽  
Green Emission ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Specific Temperature ◽  
Temperature Scanning ◽  
Scanning Electron

Cerium and gadolinium phosphate micro-meter size phosphors with average diameters of 20-50 μM were prepared. X-Ray Diffraction (XRD) data confirmed the crystalline phases of samples could be formed at different temperature. Scanning electron microscopy (SEM) investigated the morphology and crystalline of the samples, showing that many regular and large pores (100-200 μM) were dispersed within the micro-meter scale composites. We have proved the above crystal growth structures were controllable and predicable based on the current conditions.

First Evidence for the Presence of Weddellite Crystallites in Opuntia ficus indica Parenchyma

2003 ◽  
Vol 58 (11-12) ◽  
pp. 812-816 ◽  
Author(s):  
Mohamed E. Malainine ◽  
Alain Dufresne ◽  
Danielle Dupeyre ◽  
Michel R. Vignon ◽  
Mostafa Mahrouz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
X Ray Diffraction ◽  
Experimental Protocol ◽  
Opuntia Ficus Indica ◽  
Hydration Level ◽  
X Ray ◽  
Opuntia Species ◽  
Scanning Electron

Abstract Calcium oxalate crystallites occur very often in the plants tissues and their role is still poorly known. We report here the experimental protocol leading to the isolation of two forms of calcium oxalate crystallites differing in their hydration level in the parenchymal tissues of Opuntia ficus indica (Miller). Whereas the whewellite crystallites are habitual in all Opuntia species, the weddellite form has never been isolated from these species before, which is probably due to their small size (about 1 μm). We have identified these forms using X-ray diffraction and scanning electron microscopy.

Effect of Seed Crystals of Uric Acid and Monosodium Urate on the Crystallization of Calcium Oxalate in Undiluted Human Urine in Vitro

1997 ◽  
Vol 92 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Phulwinder K. Grover ◽  
Rosemary L. Ryall
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Uric Acid ◽  
Calcium Oxalate ◽  
Human Urine ◽  
Monosodium Urate ◽  
Calcium Oxalate Crystals ◽  
Seed Crystals ◽  
Oxalate Crystals ◽  
Scanning Electron

1. The aim of this study was to determine whether seed crystals of uric acid or monosodium urate promote the epitaxial deposition of calcium oxalate in undiluted human urine. The effects of seed crystals of uric acid, monosodium urate or calcium oxalate on calcium oxalate crystallization induced in pooled 24-h urine samples collected from six healthy men were determined by [14C]oxalate deposition and Coulter counter particle analysis. The precipitated crystals were examined by scanning electron microscopy. 2. Seed crystals of uric acid, monosodium urate and calcium oxalate increased the precipitated particle volume in comparison with the control containing no seeds by 13.6%, 56.8% and 206.5% respectively, whereas the deposition of [14C]oxalate in these samples relative to the control was 1.4% (P < 0.05), 5.2% (P < 0.01) and 54% (P < 0.001) respectively. The crystalline particles deposited in the presence of monosodium urate seeds were smaller than those in the control samples. Scanning electron microscopy showed that large aggregates of calcium oxalate were formed in the presence of calcium oxalate seeds, which themselves were not visible. In contrast, monosodium urate and, to a lesser extent, uric acid seeds were scattered free on the membrane surfaces and attached like barnacles upon the surface of the calcium oxalate crystals. 3. It was concluded that seed crystals of monosodium urate and uric acid do not promote calcium oxalate deposition to a physiologically significant degree in urine. Howsever, binding of monosodium urate and uric acid crystals and their subsequent enclosure within actively growing calcium oxalate crystals might occur in vivo, thereby explaining the occurrence of mixed urate/oxalate stones.

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