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PubMed2003

[Combined analyses of mixed urinary stones by XPS and XRD].

In order to seek the methods for the prevention and cure of urinary stones in Dongjiang valley in Guangdong province, the chemical constituents and morphology of six mixed urinary stones were analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD). All of the six stones consisted of calcium oxalate monohydrate (COM), calcium oxalate dihydrate (COD) and hydroxyapatite. Two of them contained little ammonium magnesium phosphate. As increasing the amount of phosphate in urinary stones, the amount of COM decreased and that of COD increased, which indicated that the sediment of phosphates in the stones can inhibit the transformation from high energy COD to low energy COM. Combining XPS and XRD methods, the compositions and phases of urinary stones can be obtained accurately.

Calcium Oxalate↗
PubMed2003

[La accumulation and microstructure change of leg bones of rats fed with La(NO(3))(3) in low dosage for a long term].

OBJECTIVE: To study La accumulation and microstructure change of leg bones of rats fed with La(NO(3))(3) in low dosage for a long term. METHODS: After the rats were fed by La(NO(3))(3) in dosage of 2 mg x (kg(-1) x d(-1)) for 6 months, the contents of La and Ca,P in the leg bones were determined by ICP MS and spectrophotometry; the microstructure changes of the leg bones were investigated by electron microscopy and X-ray powder diffraction. RESULTS: In the leg bones of tested rats, the contents of La and P increased greatly, and those of Ca did not change obviously, so that Ca/P ratio values decreased in comparison with the control group. CONCLUSION: La was accumulatied in the rat leg bones and the change of bone microstructure induced after the rats were fed with La(NO(3))(3) in low dosage for a long term.

Animals↗
PubMed1992

[Potential cardiotonics. 15. Crystal modifications of 3-cyano-2-morpholino-5-(4-pyridinyl)pyridine (AWD 122-14)].

The preparation and X-ray crystallographic characterisation of 10 polymorphic or pseudo-polymorphic forms of the novel cardiotonic AWD 122-14 are described. Thermic transformations of some polymorphic forms into the alpha-form was proved by thermogravimetric analysis and powder diffraction pattern. In dissolution behaviour no significant differences were found between the crystalline modifications but with regard to galenic processing compact alpha-, gamma- and epsilon-forms show advantages.

Cardiotonic Agents↗
PubMed1992

Extraction of calcium containing crystals from synovial fluids and articular cartilage.

A protocol for extracting minerals from biological tissues and fluids has been developed. Synovial fluid (SF) and articular cartilage samples were treated with papain and sodium hypochlorite to extract and concentrate calcium containing crystals. The method was validated by testing the ability to reextract synthetic calcium pyrophosphate dihydrate and calcium hydroxyapatite crystals added to SF in an unchanged form. The extracted crystals were analyzed by infrared spectroscopy and X-ray powder diffraction. The concentration of both calcium pyrophosphate dihydrate and hydroxyapatite crystals in SF was found to be higher than published figures.

Calcium↗
PubMed1992

Experimental calcification in rat submandibular gland.

The present study describes the phenomenon of calciphylaxis, rapid calcification due to treatment with sensitizer dihydrotachysterol (DHT) and challenging agent 5-hydroxytryptamine (5-HT) in the rat submandibular gland (SMG) in terms of light and electron microscopy, and histochemistry. For biophysical analysis of the calcified bodies, X-ray microanalysis (XMA) and X-ray powdered diffraction methods were used. The calcified lesions in the salivary glands were histologically divided into 3 types: type 1, calcification of basal membranes in duct-like structures; type 2, granular calcified materials with remarkable necrotic changes in cell, containing 3 kinds of small vesicular structures observed in electron microscopy; and type 3, von Kossa's positive structures containing needle-like crystalline and electron-dense amorphous materials. Con A and UEA-1 lectin staining reactions were strong in the type 1 and 2 lesions. These findings suggest that the calcification matrix may contain mannose, fucose and glucose. The X-ray microanalysis of calcified materials revealed the magnesium whitelockite pattern, the type 3 displayed high quantities of Ca, P, and Mg ions comparing with the type 1 and 2, and the X-ray diffraction showed the hydroxyapatite pattern. We suggest that the above changes may be categorized as dystrophic calcification due to necrotic alterations brought about by the hypercalcaemic condition.

Animals↗
PubMed1992

Calcium oxalate smear layer: mineralogical and crystallographic study.

Different methods to reduce dentine hypersensitivity have been tested by means of oxalate treatments. Natural material (20 teeth) and commercial oxalates have been employed. As a result the dentinal tubules are filled by small crystals preventing dental disease. Permeability measurements have been performed in order to quantify results. The composition of the synthetic smear layer produced after oxalate treatment have been investigated by powder diffraction method suggesting calcium oxalate formation.

Calcium Oxalate↗
PubMed2004

Comparative in vitro performance evaluation of the Novopulmon 200 Novolizer and Budesonid-ratiopharm Jethaler: two novel budesonide dry powder inhalers.

A special single dose collector and a multi stage liquid impinger were used to assess the consistency of delivered dose and fine particle fraction respectively, of the Novopulmon 200 Novolizer (Viatris, Frankfurt, Germany) and Budesonid-ratiopharm Jethaler (Ratiopharm, Ulm, Germany). The obtained average delivered dose from the Jethaler at 4 kPa is 199 microg (99.5% of the label claim) versus 219 microg (109.6%) for the Novolizer (mean of 90 doses from the same device). The corresponding relative standard deviation (RSD) for the Jethaler is on average 14.05% (maximal and minimal dose are 289 and 148 microg respectively), versus an RSD of 5.56% for the Novolizer (max. is 240; min. is 187 microg). It can be shown that the rather extreme spread in the delivered dose from the Jethaler is caused by a variation in metered mass, and to less extent by a poor content uniformity of the drug-lactose compact. The fine particle fractions (FPFs, as percent of label claim, for particles <5.1 microm) of both devices show an increase with increasing pressure drop across the inhalers, although at 4 kPa already 62% (Jethaler), respectively 72% (Novolizer) of the 'maximal' value (at 8 kPa) is achieved. FPF from the Novolizer is highest at all pressure drops and varies between 23.2% (at 2 kPa) and 54.3% (at 8 kPa). The difference in FPF between both devices increases with decreasing upper class for the FPF: the ratio of FPF from Novolizer to that from Jethaler (at 4 kPa) is 1.42 for particles < 5.1 microm versus 2.14 for particles < 1.8 microm, suggesting that the aerosol produced by the Novolizer has much greater potential for deep lung deposition.

Bronchodilator Agents↗
PubMed2004

[Spectral studies of nanosized LnVO4:Eu (Ln = La, Gd, Y)].

Nanosized LnVO4:Eu (Ln = La, Gd, Y) with diameters ranging from 20 to 50 nm were synthesized by complex sol-gel technique. The structures and spectral properties of LnVO4:Eu were studied by X-ray powder diffraction (XRD), Fourier transform (FT-IR) spectroscopy, luminescence spectra and ultraviolet spectroscopy (UV). The experimental results show that YVO4:Eu and GdVO4:Eu have similar spectral properties because they both have the structure of xenotime, while the structure of LaVO4:Eu belongs to monazite, whose symmetry is inferior to the former vanadates. Consequently the spectral properties of LaVO4:Eu are obviously different from the other two luminescence materials, as the peaks of infrared spectrum and emission spectrum become wider and the number of peaks in UV-Vis spectrum increases.

English Abstract↗
PubMed2005

[Free crystalline silica: a comparison of methods for its determination in total dust].

BACKGROUND: The major objective of the study was to compare and investigate the usefulness of quantitative analyses of free crystalline silica (FCS) in the assessment of dust exposure in samples of total dust of varied composition, using three methods: chemical method in common use in Poland; infrared spectrometry; and x-ray powder diffraction. MATERIALS AND METHODS: Mineral composition and FCS contents were investigated in 9 laboratory samples of raw materials, materials, and industrial wastes, containing from about 2 to over 80% of crystalline silica and reduced to particles of size corresponding with that of total dust. Sample components were identified using XRD and FT-IR methods. Ten independent determinations of FCS with each of the three study methods were performed in dust samples. An analysis of linear correlation was applied to investigate interrelationship between mean FCS determinations. RESULTS: In analyzed dust samples, along with silica dust there were numerous minerals interfering with silica during the quantitative analysis. Comparison of mean results of FCS determinations showed that the results obtained using the FT-IR method were by 12-13% lower than those obtained with two other methods. However, the differences observed were within the limits of changeability of results associated with their precision and dependence on reference materials used. CONCLUSIONS: Assessment of occupational exposure to dusts containing crystalline silica can be performed on the basis of quantitative analysis of FCS in total dusts using each of the compared methods. The FT-IR method is most appropriate for the FCS determination in samples of small amount of silica or collected at low dust concentrations; the XRD method for the analysis of multicomponent samples; and the chemical method in the case of medium and high FCS contents in samples or high concentrations of dusts in the work environment.

Air Pollutants, Occupational↗
PubMed2005

[Study of water-sol core-shell CdSe/CdS quantum dots].

Water-sol core/shell CdSe/CdS quantum dots (QDs) were synthesized in aqueous solution by using mercapto-acetate acid as stabilizer. The UV-Vis absorption and emission spectra were studied. The size of the SdSe-core was about 2 nm estimated by absorption edge and X-ray powder diffraction(XRD). The structure was also characterized by X-ray photoelectron spectroscopy(XPS). The intensity of luminescence of the quantum dots was greatly enhanced after the surface was modified with CdS shell. Red shift of the peak was shown in both the emission and absorption spectra.

Algorithms↗
PubMed2005

[Raman spectra study of thermal transformation of nephrite cat's eye from Sichuan province].

Raman spectrum and X-ray powder diffraction (XRD) were used to study the process andproduct of thermal transformation of nephrite cat's eye from Sichuan province. The results indicate that upon being heated till 900 degrees C, tremolite in the nephrite cat's eye is dehydrated completely and the appearance of a new characteristic band near 671 cm(-1) indicates the form of a new product. At 1 000 degrees C, the intensity of band near 1014 cm(-1) rises obviously, and the weak bands near 573 cm(-1) and 934 cm(-1) present. Up to 1100 degrees C, the band near 1033 cm(-1) appears. All these evidences show that the final thermal transformation product is identified as Ca-Mg pyroxene which is similar to diopside both in structure and in composition. This conclusion is confirmed by XRD.

English Abstract↗
PubMed2006

Large-scale synthesis of single crystal silver nanowires by a sodium diphenylamine sulfonate reduction process.

Silver nanowires with high aspect ratios of up to more than 60 were synthesized on a large scale by the redox reaction between silver nitrate and sodium diphenylamine sulfonate at room temperature and in the absence of surfactant and hard-template and seed. When the molar ratio of reductant sodium diphenylamine sulfonate and silver nitrate < or =1, most products were all the nanowires. When the molar ratio increases to 2:1, silver nanowires and nanobelts were concomitantly formed. The redox product N, N'-diphenylbenzidinedisulfonate and sodium diphenylamine sulfonate all play an important role in the formation of silver nanostructures. The structure, morphology, and composition of the silver nanowires were characterized by the X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray energy dispersive microanalysis (EDX), and UV-Vis spectroscopy respectively. High-resolution transmission microscopy (HRTEM) and selected area electron diffraction (SAED) reveal the single-crystal nature of the silver nanowires.

Benzenesulfonates↗
PubMed2006

Surfactant-assisted synthesis and characterization of SrCrO4 nanostructures.

A simple and efficient microemulsion-based technique, which used the new Tx-100/cyclohexanol/ H2O system, was developed to synthesize SrCrO4 nanowire based nanostructures, including nanowire bundles and flower-like structures at different temperature. X-ray powder diffraction (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to characterize the products. Studies found that the reaction temperatures and the reaction systems have great influences on the final products. Optical properties studies by UV-Vis spectra and photoluminescence (PL) spectra confirmed that the as-obtained nanowires showed distinct optical activity under UV and visible light irradiation.

Chromates↗
PubMed2006

Application of novel chitosan derivatives in dissolution enhancement of a poorly water soluble drug.

Solid dispersions of the poorly water soluble drug dexamethasone and newly synthesized chitosan derivatives (chitosan succinate, CS, and chitosan phthalate, CP) were prepared by spray drying. The resulting microspheres were evaluated in terms of their drug loading or encapsulation efficiency as well as drug release profile. Differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and infrared spectroscopy (IR) were used to evaluate the solid dispersion for possible interactions between drug and polymers. The pure drug was evaluated in the same manner for comparison purposes. High loading levels (>74%) were achieved using CP and CS as polymer matrices. Drug release rate was accelerated significantly upon the formation of the solid dispersions; the drug release rate was increased with increasing percentage of the chitosan derivatives in the microspheres. IR studies showed no chemical interaction while the X-ray studies showed a significant change in the crystallinity of the drug upon formation of solid dispersions.

Algorithms↗
PubMedDate not supplied

Availability and chemical composition of traditional eye cosmetics ("kohls") used in the United Arab Emirates of Dubai, Sharjah, Ajman, Umm Al-Quwain, Ras Al-Khaimah, and Fujairah.

This study was undertaken in order to determine the availability and chemical composition of potentially lead-toxic traditional eye cosmetics ("kohls") in six of the seven emirates of the United Arab Emirates (UAE). Thus of especial interest was the percentage of the purchased samples that contained the toxic element lead. A total of 53 observably different kohl samples were found to be available overall in the six emirates: Dubai, Sharjah, Ajman, Umm Al-Quwain, Ras Al-Khaimah, and Fujairah. It was found that 19 of these samples had been previously analyzed by us in studies covering Oman, Abu Dhabi (city), and Egypt (Cairo). The techniques of X-ray powder diffraction (XRPD) and scanning electron microscopy (SEM) were used to analyze the remaining 34 samples. Overall, for the 53 kohl samples, it was found that 20 (38%) contained a lead compound (galena, PbS) as the main component. The other main components were found to be one of the following: amorphous carbon, calcite/aragonite (CaCO3), goethite (FeO(OH)), hematite (Fe2O3), sassolite (H3BO3), talc (Mg3Si4O10(OH)2), or zincite (ZnO).

Cosmetics↗
PubMed2006

[A study of preparation and infrared absorbency of La2O3 nanocrystals].

Nanocrystals were prepared by stearic acid gel method. The structure and morphology of nanocrystals were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM) and infrared spectra. Experimental results show that the absorption peaks of La2O3 extendwith their blue shift or red shift. The absorption of La2O3 nanocrystals is good in the wavelength range of 1 000 to 1 700 nm, where La2O3 nanocrystals may serve as a kind of absorbent of laser camouflage material.

English Abstract↗
PubMed2006

[Photoluminescence properties of A2SnO4 (A = Ca, Sr, Ba) : Eu nanocrystalline].

Nanosized A2SnO4 (A = Ca, Sr, Ba) : 1% Eu with diameters ranging from 50 to 100 nm were synthesized by complex sol-gel methods. The structures and spectral properties of A2SnO4 (A = Ca, Sr, Ba) : Eu were studied by using X-ray powder diffraction (XRD) and luminescence spectra. The experimental results show that Ca2SnO4 : 1% Eu exhibits bright red emission at about 615 nm under UV excitation, which makes it a possible good candidate for FED application. However Sr2SnO4 : 1% Eu and Ba2SnO4 : 1% Eu exhibit orange emission at about 590 nm because in these hosts Eu3+ ions occupy the symmetric sites.

Barium↗
PubMed1991

Influence of ageing, pH and various additives on crystal formation in artificial urine.

In order to investigate the effect of various factors on urinary crystallization processes, a series of five experiments was carried out using an artificial urine (AU) in a rotary evaporator. The influence of ageing, pH and organic, inorganic and potential inhibitory additives formed the basis of the study. Precipitates were characterized by X-ray powder diffraction, scanning electron microscopy and energy dispersive X-ray analysis. In the ageing experiment, AU aliquots, adjusted to various pH values, were allowed to stand for several days and were not evaporated. Calcium oxalate monohydrate (COM) was formed at low pH, while whitlockite, apatite and struvite occurred at pH greater than 7. In the second experiment, AU aliquots at various pH values, were evaporated. Similar results to those of series 1 were recorded but, in addition, calcium oxalate trihydrate (COT) precipitated in the pH range 3 to 6.5 and brushite at pH greater than 5.5. In series 3, uric acid, creatinine and urea were included in AU aliquots (pH 5.5) which were subjected to evaporation. Uric acid promoted the formation of uric acid dihydrate; however, when present with creatinine, dihydrate formation was inhibited. Urea appeared to inhibit precipitation. In the fourth experiment, MgO, methylene blue and chondroitin sulphate A were independently included in the AU (pH 5.5). Precipitates of calcium oxalate mono-, di- and trihydrates were obtained. In the final experiment fluoride aliquots of variable concentrations were included in the AU (pH 5.5 and 6.5). COT crystals of superior quality to those observed in control solutions were obtained.

Calcium Oxalate↗