25 research outputs found
Effect of Curcumin Against Proteus mirabilis During Crystallization of Struvite from Artificial Urine
We investigated the activity of curcumin against Proteus mirabilis and the struvite crystallization in relation to urinary stones formation. In order to evaluate an activity of curcumin we performed an in vitro experiment of struvite growth from artificial urine. The crystallization process was induced by Proteus mirabilis to mimic the real urinary tract infection, which usually leads to urinary stone formation. The results demonstrate that curcumin exhibits the effect against Proteus mirabilis inhibiting the activity of urease—an enzyme produced by these microorganisms. Addition of curcumin increases the induction time and decreases the efficiency of growth of struvite compared with the absence of curcumin. Interestingly, the addition of curcumin does not affect the crystal morphology and habit. In conclusion, curcumin has demonstrated its significant potential to be further investigated for its use in the case of struvite crystallization induced for the growth by Proteus mirabilis in relation to urinary stone formation
First experimental evidence of the piezoelectric nature of struvite
In this paper, we present the first experimental evidence of the piezoelectric nature of struvite
(
MgNH4PO4·6H2O). Using a single diffusion gel growth technique, we have grown struvite crystals in
the form of plane parallel plates. For struvite crystals of this shape, we measured the piezoelectric
coefficients d33 and d32. We have found that at room temperature the value of piezoelectric coefficient
d33 is 3.5 pm/V, while that of d32 is 4.7 pm/V. These values are comparable with the values for other
minerals. Struvite shows stable piezoelectric properties up to the temperature slightly above 350 K,
for the heating rate of 0.4 K/min. For this heating rate, and above this temperature, the thermal
decomposition of struvite begins, which, consequently, leads to its transformation into dittmarite
with the same non-centrosymmetric symmetry as in case of struvite. The struvite-dittmarite
transformation temperature is dependent on the heating rate. The higher the heating rate, the higher
the temperature of this transformation. We have also shown that dittmarite, like struvite exhibits
piezoelectric properties
First experimental evidences of the ferroelectric nature of struvite
Struvite (MgNH4PO4·6H2O) is a mineral first
identified in 1845. It is tested for several reasons: (1) it is a
problem in liquid wastewater treatment plants; (2) on the other
hand, it is recovered from this wastewater because of phosphorus,
magnesium, and nitrogen; (3) it is the main component of
infectious urinary stones. In this paper, we present the first
experimental evidences of the ferroelectric nature of struvite at
room temperature. Struvite shows a hysteresis loop and
spontaneous electric polarization that can be reversed by an
application of an external electric field. The measured value of
residual polarization of struvite is equal to 0.95 μC/cm2. We also report observations of the ferroelectric domains in struvite using
birefringence imaging technique. The non-centrosymmetry of the crystal lattice is confirmed with the use of the Kurtz−Perry powder
test. The second harmonic generation response for struvite in relation to that of potassium dihydrogen phosphate is 0.36. We suggest
that ferroelectric properties for struvite, in particular, spontaneous polarization, can have a significant impact on the behavior of
struvite in aqueous solutions, such as liquid wastewater or urine
Solid Phases Precipitating in Artificial Urine in the Absence and Presence of Bacteria Proteus mirabilis—A Contribution to the Understanding of Infectious Urinary Stone Formation
Magnesium ammonium phosphate hexahydrate, called struvite, is the dominant component of infectious urinary stones. In addition to struvite, infectious urinary stones include solid phases with poor crystallinity as well as amorphous matter. This article is devoted to the analysis of these solid phases, because they have not been characterized well until now. The solid phases tested were obtained from artificial urine in the absence and presence of Proteus mirabilis. The solid phases were characterized by different techniques (X-ray Diffraction, Energy Dispersive X-ray, Scanning Electron Microscopy, as well as Raman and Infrared Spectroscopies). According to the results these phases are carbonate apatite (CA), hydroxylapatite (HAP), amorphous calcium carbonate (ACC), amorphous calcium phosphate (ACP) and/or amorphous carbonated calcium phosphate (ACCP). Carbonate apatite and hydroxylapatite may occur in non-stoichiometric forms, i.e., various anions can be substituted for CO32−, OH−, and PO43− groups in them. The non-stoichiometry of carbonate apatite and hydroxylapatite also implies a deficiency of calcium ions, i.e., calcium ions may be partially replaced by other cations. Experimental techniques and chemical speciation analysis demonstrate that the presence of magnesium influences the formation of CA and HAP
Biological and Biogenic Crystallization
The intention of the Special Issue ""Biological and Biogenic Crystallization"" was to create an international platform aimed at covering a broad field of results involving the crystallization of biological molecules, including virus and protein crystallization, biogenic crystallization including physiological and pathological crystallization taking place in living organisms (human beings, animals, plants, bacteria, etc.), and bio-inspired crystallization. Despite many years of research on biological and biogenic crystals, there are still open questions as well as hot and timely topics. This Special Issue contains seven articles that present a cross-section of the current research activities in the of field of biological and biogenic crystals. The authors of the presented articles prove the vibrant and topical nature of this field. We hope that this Special Issue will serve as a source of inspiration for future investigations, and will be useful for scientists and researchers who work on the exploration of biological and biogenic crystals
Correlation Between Crystal Structure, Relative Growth Rates and Evolution of Crystal Surfaces
According to most crystal growth theories, the "as grown" crystal morphology is dominated by the slow-growing faces and the fast-growing faces may "grow out" and not be represented in the final crystal habit. In this paper a brief survey is given of the recently developed correlation between the evolution of both fast- and slow-growing surfaces, their relative growth rates, and the crystallographic structure of crystal. It is shown that even the fast-growing faces may increase their sizes. On the other hand, the slow-growing faces may decrease and, in consequence, disappear from crystal morphology. Such a behaviour of slow- and fast-growing surfaces influences the growth and evolution of both low- and high-index faces
Correlation between growth of high-index faces, relative growth rates and crystallographic structure of crystal
According to contemporary crystal growth theories, crystals are bound by low-index faces which are
the most slowly growing. However, high-index faces are observed in crystal habits more and more
often. In this paper the growth of high-index faces is analysed from a crystallographic perspective. It
is shown that the crystallographic structure of a given crystal, expressed by the trigonometric
function of appropriate interfacial angles, influences to great degree the crystallisation process and
the morphology of crystals, in particular the behaviour of high-index faces. Additionally, it is
concluded that at particular crystallographic structure of a crystal, a given high-index face may exist
in the habit and develop its size, although it grows much faster than the neighbouring faces
Correlation Between Crystal Structure, Relative Growth Rates and Evolution of Crystal Surfaces
According to most crystal growth theories, the "as grown" crystal morphology is dominated by the slow-growing faces and the fast-growing faces may "grow out" and not be represented in the final crystal habit. In this paper a brief survey is given of the recently developed correlation between the evolution of both fast- and slow-growing surfaces, their relative growth rates, and the crystallographic structure of crystal. It is shown that even the fast-growing faces may increase their sizes. On the other hand, the slow-growing faces may decrease and, in consequence, disappear from crystal morphology. Such a behaviour of slow- and fast-growing surfaces influences the growth and evolution of both low- and high-index faces
Research Article Effect of Curcumin Against Proteus mirabilis During Crystallization of Struvite from Artificial Urine
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We investigated the activity of curcumin against Proteus mirabilis and the struvite crystallization in relation to urinary stones formation. In order to evaluate an activity of curcumin we performed an in vitro experiment of struvite growth from artificial urine. The crystallization process was induced by Proteus mirabilis to mimic the real urinary tract infection, which usually leads to urinary stone formation. The results demonstrate that curcumin exhibits the effect against Proteus mirabilis inhibiting the activity of urease—an enzyme produced by these microorganisms. Addition of curcumin increases the induction time and decreases the efficiency of growth of struvite compared with the absence of curcumin. Interestingly, the addition of curcumin does not affect the crystal morphology and habit. In conclusion, curcumin has demonstrated its significant potential to be further investigated for its use in the case of struvite crystallization induced for the growth by Proteus mirabilis in relation to urinary stone formation. 1