Sem Studies of Co-Cr-Mo Surgical Implant Alloy Corrosion Behavior

1982 ◽  
Vol 40 ◽  
pp. 520-521
Author(s):  
Ann Chidester Van Orden ◽  
John L. Chidester ◽  
Anna C. Fraker ◽  
Pei Sung
Keyword(s):  
Electron Microscopy ◽  
Corrosion Behavior ◽  
Anodic Polarization ◽  
Saline Solution ◽  
Saturated Calomel Electrode ◽  
Physiological Saline ◽  
X Ray ◽  
Physiological Saline Solution ◽  
Scanning Electron

The influence of small variations in the composition on the corrosion behavior of Co-Cr-Mo alloys has been studied using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), and electrochemical measurements. SEM and EDX data were correlated with data from in vitro corrosion measurements involving repassivation and also potentiostatic anodic polarization measurements. Specimens studied included the four alloys shown in Table 1. Corrosion tests were conducted in Hanks' physiological saline solution which has a pH of 7.4 and was held at a temperature of 37°C. Specimens were mechanically polished to a surface finish with 0.05 µm A1203, then exposed to the solution and anodically polarized at a rate of 0.006 v/min. All voltages were measured vs. the saturated calomel electrode (s.c.e.).. Specimens had breakdown potentials near 0.47V vs. s.c.e.

Erythrophagocytosis by Entamoeba histolytica.- Ultrastructural Study

1972 ◽  
Vol 30 ◽  
pp. 156-157 ◽  
Author(s):  
Norberto Treviño ◽  
Alfredo Feria-Velasco ◽  
I. Ruiz de Chávez
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Entamoeba Histolytica ◽  
Ultrastructural Study ◽  
Saline Solution ◽  
Physiological Saline ◽  
Ultrastructural Level ◽  
Hot Plate ◽  
Physiological Saline Solution ◽  
Axenic Conditions

Although erythrophagocytosis by various species of Entamoeba is a well known phenomenon this has not yet been studied in detail at the ultrastructural level. The present work deals with the description of the incorporation process of erythrocytes by trophozoites of E. histolytica. For this study, trophozoites of E. histolytica, HK-9:NIH strain cultured in axenic conditions and washed human erythrocytes were placed on a hot plate at 37°C in physiological saline solution. After 5 minutes, 2.5% glutarldehyde was added and the samples were processed according to conventional techniques for electron microscopy.Based upon light microscopy studies on living trophozoites in contact with erythrocytes, it seems that erythrophagocytosis only takes place in one pole of the parasite.

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.

Study on Corrosion Behavior of Al-Zn-In and Al-Zn-Ga Alloys in NaCl Solution

2011 ◽  
Vol 284-286 ◽  
pp. 1701-1704
Author(s):  
Jing Ling Ma ◽  
Jiu Ba Wen ◽  
Gao Lin Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electrochemical Impedance Spectroscopy ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Nacl Solution ◽  
X Ray ◽  
Inductive Loop ◽  
Capacitive Loop ◽  
Scanning Electron

The corrosion behavior of Al-5Zn-0.03In and Al-5Zn-0.03Ga alloys in 3.5 % NaCl solution has been examined by electrochemical methods, scanning electron microscopy, X-ray microanalysis, electrochemical impedance spectroscopy. The results demonstrate that the alloys differ in the microstructure, corroded morphology and electrochemical properties. For Al-5Zn-0.03In alloy, the precipitates enriched in Al and Zn initiates pitting. For Al-5Zn-0.03Ga alloy, corrosion occurs more uniformly, the corrosion of the alloy occurred via the formation of a surface Ga-Al amalgam alloy. The EIS of Al-5Zn-0.03In alloy contains a capacitive loop and an inductive loop; the inductive loop can be attributed to the presence of the pitting. The EIS of Al-5Zn-0.03Ga alloy contains only a capacitive loop.

Corpus cardiacum stimulated trehalose efflux from cockroach (Periplaneta americana) fat body: control by calcium

1985 ◽  
Vol 63 (1) ◽  
pp. 63-66 ◽  
Author(s):  
J. E. Steele ◽  
T. Paul
Keyword(s):  
Cyclic Amp ◽  
Periplaneta Americana ◽  
Saline Solution ◽  
Fat Body ◽  
Surrounding Medium ◽  
Physiological Saline ◽  
Corpus Cardiacum ◽  
Physiological Saline Solution ◽  
Stimulation Of

Cockroach fat body incubated in a simple physiological saline solution releases trehalose to the surrounding medium. The output of trehalose occurs in the absence of ambient Ca2+ and decreases slowly with time. In two separate experiments, 0.1 mM CaCl2 added to the saline increased the output of trehalose on average by 70% but higher concentrations of Ca2+ did not further increase the efflux of trehalose. Stimulation of trehalose efflux by corpus cardiacum extract is absolutely dependent on extracellular Ca2+, no increase occurring beyond the basal level in the absence of the ion. The activity of corpus cardiacum extract increases as the concentration of CaCl2 is increased to 0.5 mM. This concentration of Ca2+ in the saline permits the extract to increase trehalose efflux by as much as 60% above the basal level. Corpus cardiacum extract, as well as the hypertrehalocaemic agents cyclic AMP and theophylline, increase significantly the influx of Ca2+ into fat body in vitro. The basal efflux of trehalose from fat body and that stimulated by corpus cardiacum extract is not dependent on extracellular Mg2+.

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.

scholarly journals Silver Nanoparticles: Green Synthesis, Characterization, Blood Compatibility and Protoscolicidal Efficacy against Echinococcus granulosus

2021 ◽  
Vol 41 (03) ◽  
pp. 393-399
Author(s):  
Parwin Jalal Jalil
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Echinococcus Granulosus ◽  
Blood Compatibility ◽  
Ag Nps ◽  
X Ray ◽  
Hydatid Fluid ◽  
Scanning Electron

Spillage of protoscoleces within hydatid fluid during surgery for hydatid cyst is the main reason for its recurrence. Therefore, to inactivate the protoscoleces, various scolicidal substances have been tested. However, novel and more efficient agents are needed owing to several associated complications. This study focused on the effects of green synthetic Silver Nanoparticles (AgNPs) from Zizyphus spina- christi leaves on Echinococcus granulosus protoscoleces. Also, to evaluate the blood compatibility of Ag NPs. The Ag NPs were identified by ultraviolet-visible (UV-Visible) spectrophotometer, X-ray diffraction (XRD), Scanning electron microscopy imaging, and Energy-dispersive X-ray spectroscopy (EDX). Hydatid fluid was aspirated aseptically from cysts of infected sheep liver. The protoscoleces were exposed to Ag NPs at several concentrations. Also, scanning electron microscopy for ultrastructural changes and in vitro erythrocytes lysis was performed. The Ag NPs were spherical; the particles' size reached 50 nm, and presented a surface plasmon peak around 460 nm. The current study's findings indicated the powerful in vitro scolicidal efficacy of the green biosynthesized AgNPs. Several morphological alterations were observed on the protoscoleces by optical and scanning electron microscopy. Lysis of RBCs at different doses of Ag NPs was significantly (P≤0.05) less than the positive control value, thus proposing its biocompatibility. This work suggests that chemicals like polyphenols present in the extract of Z. spina- christi act as reducing and stabilizers agents to create Ag NPs Nevertheless, further investigations are needed to investigate the Ag NPs scolicidial effects in animal models.

Applications of Soft X-Ray and other Microscopy Techniques to Elucidate the Structure of Parasitic Metazoa

1998 ◽  
Vol 4 (S2) ◽  
pp. 1156-1157
Author(s):  
W. J. Kozek ◽  
J. Brown ◽  
W. Meyer-Ilse ◽  
C. Larabell ◽  
M. Moronne
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Trichinella Spiralis ◽  
National Laboratory ◽  
Confocal Laser ◽  
X Ray ◽  
New Information ◽  
Microscopy Techniques ◽  
Scanning Electron

The small size of many parasitic organisms requires the use of election microscopy for adequate elucidation of their structure. While both transmission and scanning electron microscopy can provide complementary results which allow considerable degree of structural correlation, each technique has its inherent limitations. Since previous studies have demonstrated that soft X-ray microscopy could be used to study parasitic protozoa and provide new information, the objective of this study was to determine whether soft X-ray microscopy could also be used to elucidate the morphology of small metazoa to complement the data obtained by other microscopy techniques.Newborn larvae, approximately 7 μm × 110 μm in size, of parasitic nematode Trichinella spiralis were used as a model system. Some of the larvae, deposited by adult females maintained in vitro, were isolated and processed for examination by transmission and scanning electron microscopy as described in our previous studies, others were fixed in 4% glutaraldehyde (Millonig's buffer) and examined in the X-ray microscope XM-1, and in the BioRad MRC 1024 confocal laser (krypton/argon) microscope of the Advanced Light Source, Berkeley National Laboratory.

scholarly journals Fabrication, Mechanical Properties and In-Vitro Behavior of Akermanite Bioceramic

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4887
Author(s):  
Fariborz Tavangarian ◽  
Caleb A. Zolko ◽  
Sorour Sadeghzade ◽  
Marwan Fayed ◽  
Keivan Davami
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Subsequent Annealing ◽  
Apatite Formation ◽  
X Ray ◽  
Transmission Electron ◽  
Powder Samples ◽  
Sbf Solution ◽  
Scanning Electron

Pure nanocrystalline akermanite (Ca2MgSi2O7) powder was synthesized by mechanical activation with subsequent annealing of talc, calcium carbonate, and silicate powders as the initial materials. Powder samples were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) techniques. The results showed that pure nanocrystalline akermanite with a crystalline size of 35 nm was synthesized after ball milling the initial powders for 20 h with subsequent annealing at 900 °C for 1 h. Mechanical properties of bulk akermanite samples were studied as well. The results showed that the produced akermanite tablets sintered at 1200 °C for 5 h had a Young’s modulus of 3800 MPa, an ultimate compressive strength of 24.7 MPa, and a density of 2.489 g/cm3. The in-vitro behavior of the produced akermanite was evaluated by soaking the samples in an SBF solution. The results showed that the produced akermanite had the apatite formation ability on its surface and can be a good candidate for bone tissue engineering applications.

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