Formation de Weddellite (CaC2O4∙2H2O) extracellulaire en culture in vitro par Paxillus involutus; signification de cette production pour la symbiose ecto- mycorhizienne

1984 ◽  
Vol 62 (6) ◽  
pp. 1116-1121 ◽  
Author(s):  
F. Lapeyrie ◽  
Monique Perrin ◽  
R. Pepin ◽  
G. Bruchet
Keyword(s):  
Calcium Oxalate ◽  
Culture Medium ◽  
Calcium Content ◽  
Ectomycorrhizal Fungus ◽  
Paxillus Involutus ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Calcium ◽  
Scanning Electron

Several forms of extracellular crystals have been observed in vitro on a semisynthetic culture medium. The conditions for their formation have not been determined. Their morphology and their localisation on the hyphal surface and in the culture medium have been investigated by means of scanning electron microscopy. These crystals have been identified as dehydrated calcium oxalate (Weddellite) using x-ray diffraction methods. Their high calcium content has been demonstrated with the scanning electron microprobe, by detecting the x-ray emission of calcium. The significance of calcium oxalate production by an ectomycorrhizal fungus is discussed.

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.

Mesenchymal Stem Cell Response to Surface Altered Porous Ti

2015 ◽  
Vol 638 ◽  
pp. 67-72
Author(s):  
Ana Maria Salantiu ◽  
Florin Popa ◽  
Petru Pascuta ◽  
Olga Soritau ◽  
Noemi Dirzu ◽  
...  
Keyword(s):  
Stem Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemically Modified ◽  
Porous Ti ◽  
Average Porosity ◽  
Ft Ir ◽  
Cell Testing ◽  
Scanning Electron

This work aims to investigate the influence of surface conditioning of porous Ti for enhancing its biological activity, as assessed by in vitro stem cell testing. Porous Ti samples with an average porosity of 32% were processed by Powder Metallurgy with dextrin as a space holder. The samples were subjected to H2O2 treatment to form an enhanced TiO2 film, followed by a heat treatment at 400°C and 600°C aiming to the crystallization of the as-formed amorphous titanium oxide. Samples characterization was performed by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The treated surfaces revealed to be made of both anatase and rutile TiO2, with groove–shaped structure and cracks on the surface of the TiO2 film. The intrinsic biocompatibility of the chemically modified porous Ti surfaces was assessed in vitro. In our cell culture tests, stem cells were found to attach and proliferate better on the chemically treated Ti surfaces compared to the control untreated Ti surfaces.

scholarly journals Development of an Oxcarbazepine Solid Dispersion Using Skimmed Milk to Improve the Solubility and Dissolution Profile

2019 ◽  
Vol 11 (05) ◽  
Author(s):  
M. Shah ◽  
D. Patel
Keyword(s):  
Electron Microscopy ◽  
Solid Dispersion ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Infra Red ◽  
Crystalline Nature ◽  
Skimmed Milk ◽  
Scanning Electron

Oxcarbazepine has low solubility and low oral bioavailability, so it’s a challenge to formulate suitable dosage form. In this present investigation, to improve the dissolution rate and solubility, skimmed milk is used as a carrier. Physical mixers were prepared using various drugs to carrier ratio and spray drying technology was used to develop solid dispersion with the carrier. Various techniques were used to characterize the solid dispersion immediately after they were made which includes differential scanning calorimetry, scanning electron microscopy, fourier transform infra- red spectroscopy, X-ray diffraction and in-vitro dissolution profiles. The differential scanning calorimetry thermograms of raw drug indicated of its anhydrous crystalline nature. In thermograms of solid dispersion, the characteristic peak was absent suggesting the change from crystalline nature to amorphous form. X-ray diffraction confirmed those results. X-ray diffraction results of raw drug showed highly intense peak characteristic of its crystalline nature where solid dispersion showed less intense, more diffused peak indicating the change in crystalline form. Fourier transforms infra-red spectroscopy studies showed there was no interaction between drug and carrier. Scanning electron microscopy support the amorphous nature of mixer. The whole formulation showed distinct enhancement in the drug release behavior and solubility. The optimum oxcarbazepine to skimmed milk ratio 1:3 enhances the in-vitro drug release by 3.5 fold and also show distinct increase in solubility. It was concluded that for improvement of solubility of poorly water soluble oxcarbazepine, skimmed milk powder as a carrier can be utilize very well.

Bioactive Composite Materials for Bone Tissue Applications

2006 ◽  
Vol 514-516 ◽  
pp. 985-989
Author(s):  
B.J.M. Leite Ferreira ◽  
M.G.G.M. Duarte ◽  
M. Helena Gil ◽  
Rui N. Correia ◽  
J. Román ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bone Tissue ◽  
Tissue Repair ◽  
Body Fluid ◽  
In Vitro Bioactivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Biodegradable Composite ◽  
Scanning Electron

Two materials with potential application in bone tissue repair have been developed: 1) a non-biodegradable composite based in a new methacrylic-co-acrylic matrix; and 2) a biodegradable composite based in a chitosan (Ch) matrix. Both matrices were reinforced with glass-ceramic particles of composition (mol%) 70 SiO2 – 30 CaO. The in vitro bioactivity of composites was assessed by soaking in simulated body fluid (SBF) for periods of up to 7 days at 37º C. X-ray diffraction (XRD) and scanning electron microscopy coupled with X-ray energy dispersive spectroscopy (SEM-EDS) were used for deposit identification after different soaking periods. Calcium phosphate particulate deposits were detected after 3 days of immersion, followed by growth and maturation towards apatite.

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.

scholarly journals Preparation and Biocompatibility of Poly Methyl Methacrylate (PMMA)-Mesoporous Bioactive Glass (MBG) Composite Scaffolds

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 180
Author(s):  
Irina Atkinson ◽  
Ana Maria Seciu-Grama ◽  
Oana Catalina Mocioiu ◽  
Ana Maria Mocioiu ◽  
Luminita Predoana ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Composite Scaffold ◽  
Bone Diseases ◽  
X Ray Diffraction ◽  
Composite Scaffolds ◽  
X Ray ◽  
In Vitro Biocompatibility ◽  
Mesoporous Bioactive Glass ◽  
Scanning Electron

In recent years, the rising number of bone diseases which affect millions of people worldwide has led to an increased demand for materials with restoring and augmentation properties that can be used in therapies for bone pathologies. In this work, PMMA- MBG composite scaffolds containing ceria (0, 1, 3 mol%) were obtained by the phase separation method. The obtained composite scaffolds were characterized by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. UV–Vis measurement and EDX analysis confirmed the presence of cerium ions in the composite scaffolds. Evaluation of the in-vitro biocompatibility using MTT assay showed that composite scaffold containing 1 mol% of ceria presented higher viability than control cells (100%) for concentrations ranging between 5 and 50% after 96 h of incubation.

Characterization of Hydroxyapatite-Titanium Oxide Scaffolds Made by the Polymeric Sponge Method

2012 ◽  
Vol 727-728 ◽  
pp. 1113-1118 ◽  
Author(s):  
A.G.S. Galdino ◽  
Cecília A.C. Zavaglia
Keyword(s):  
Electron Microscopy ◽  
Titanium Oxide ◽  
Bone Reconstruction ◽  
X Ray Diffraction ◽  
Technical Literature ◽  
X Ray ◽  
Polyurethane Sponge ◽  
Scanning Electron

Along decades, bioceramics have been used as materials for bone reconstruction, where hydroxyapatite is one of the most used bioceramics. But hydroxyapatite mechanical strength is not so high when compared with another bioceramics. This research aimed to characterize hydroxyapatite-titanium oxide scaffolds with different compositions. Samples were made using a polyurethane sponge with compositions of 70%-30% wt., 60%-40% wt. and 50%-50% wt. of hydroxyapatite-titanium oxide, calcined at 550°C for burning the polymeric sponge and sintered at 1250°C, 1300°C and 1350°C. Samples were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD) and energy dispersive x-ray spectroscopy (EDS). Results showed that all compositions maintained the polymeric sponge pores structure without any residual traces of the polymeric sponge. Those results are in accordance with technical literature and it is indicated to do in vitro essays to study the scaffolds biocompatibility for using as bone reconstruction materials.

Influence of Strontium on In Vitro Bioactivity of Heat-Treated Porous Ca-P Ceramics on Titanium for Biomedical Applications

2011 ◽  
Vol 493-494 ◽  
pp. 453-457
Author(s):  
Kuan Chen Kung ◽  
Tzer Min Lee ◽  
Truan Sheng Lui
Keyword(s):  
Body Fluid ◽  
Biomedical Applications ◽  
Clinical Applications ◽  
Apatite Layer ◽  
X Ray Diffraction ◽  
Apatite Phase ◽  
X Ray ◽  
Heat Treated ◽  
Scanning Electron

The bioactivity of materials was evaluated based on the ability to induce a bond-like apatite layer on the surface in simulated body fluid (SBF). The aim of this study was to investigate the coatings containing strontium on bioactivity after heat treatment. After the materials were soaked in SBF for 1 day, precipitates did not form on the surface of heat-treated MAO coating without strontium. The precipitates were observed on surface of heat-treated MAO coatings containing strontium. After 7 days, the surface of heat-treated MAO coatings containing strontium was completely covered with precipitates. The precipitates were found to be composed of fiber structures using scanning electron microscope (SEM). The phase was identified as the apatite phase using thin film X-ray diffraction (TF-XRD). The results show that heat-treated MAO coatings containing strontium can induce the formation of an apatite layer on their surface. All finding in this study indicated that heat-treated MAO coatings containing strontium have good bioactivity for clinical applications.

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