scholarly journals Biomimetic Strontium Substituted Calcium Phosphate Coating for Bone Regeneration

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 908
Author(s):  
Marcella Torres Maia ◽  
Ana Lorena de Brito Soares ◽  
Matheus Afio Caetano ◽  
Fábia Karine Andrade ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Metal Ion ◽  
Culture Media ◽  
Optimal Dose ◽  
Bone Diseases ◽  
Calcium Phosphate Coating ◽  
Sem Images ◽  
Bioactive Coatings ◽  
X Ray ◽  
Strontium Phosphate

Cellulose acetate (CA)/strontium phosphate (SrP) hybrid coating has been proposed as an effective strategy to build up novel bone-like structures for bone healing since CA is soluble in most organic solvents. Strontium (Sr2+) has been reported as a potential agent to treat degenerative bone diseases due to its osteopromotive and antibacterial effects. Herein, bioactive hybrid composite SrP-based coatings (CASrP) were successfully produced for the first time. CASrP was synthesized via a modified biomimetic method (for 7—CA7dSrP, and 14 days—CA14dSrP), in which the metal ion Sr2+ was used in place of Ca2+ in the simulated body fluid. Energy-dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR) analysis confirmed the SrP incorporation chemically in the CASrP samples. Atomic absorption spectroscopy (AAS) supported EDX data, showing Sr2+ adsorption into CA, and its significant increase with the augmentation of time of treatment (ca. 92%—CA7dSrP and 96%—CA14dSrP). An increment in coating porosity and the formation of SrP crystals were evidenced by scanning electron microscopy (SEM) images. X-ray diffraction (XRD) evidenced a greater crystallinity than CA membranes and a destabilization of CA14dSrP structure compared to CA7dSrP. The composites were extremely biocompatible for fibroblast and osteoblast cells. Cell viability (%) was higher either for CA7dSrP (48 h: ca. 92% and 115%) and CA14dSrP (48 h: ca. 88% and 107%) compared to CA (48 h: ca. 70% and 51%) due to SrP formation and Sr2+ presence in its optimal dose in the culture media (4.6–9 mg·L−1). In conclusion, the findings elucidated here evidence the remarkable potential of CA7dSrP and CA14dSrP as bioactive coatings on the development of implant devices for inducing bone regeneration.

Mosaic Mapping: A Means of Tiling Images to Shorten Acquisition Speed for Lower - Magnification SEM Images and Wavelength Dispersive Spectrometers (WDS) X-Ray Maps

1996 ◽  
Vol 54 ◽  
pp. 438-439
Author(s):  
J.D. Geller ◽  
C.R. Herrington
Keyword(s):  
Limiting Factors ◽  
X Rays ◽  
Angular Range ◽  
Acceptance Angle ◽  
Sem Images ◽  
Worst Case ◽  
X Ray ◽  
Focusing Distance ◽  
Layered Crystals ◽  
Working Distance

The minimum magnification for which an image can be acquired is determined by the design and implementation of the electron optical column and the scanning and display electronics. It is also a function of the working distance and, possibly, the accelerating voltage. For secondary and backscattered electron images there are usually no other limiting factors. However, for x-ray maps there are further considerations. The energy-dispersive x-ray spectrometers (EDS) have a much larger solid angle of detection that for WDS. They also do not suffer from Bragg’s Law focusing effects which limit the angular range and focusing distance from the diffracting crystal. In practical terms EDS maps can be acquired at the lowest magnification of the SEM, assuming the collimator does not cutoff the x-ray signal. For WDS the focusing properties of the crystal limits the angular range of acceptance of the incident x-radiation. The range is dependent upon the 2d spacing of the crystal, with the acceptance angle increasing with 2d spacing. The natural line width of the x-ray also plays a role. For the metal layered crystals used to diffract soft x-rays, such as Be - O, the minimum magnification is approximately 100X. In the worst case, for the LEF crystal which diffracts Ti - Zn, ˜1000X is the minimum.

scholarly journals Hydrochloric Acid Modification and Lead Removal Studies on Naturally Occurring Zeolites from Nevada, New Mexico, and Arizona

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry
Keyword(s):  
New Mexico ◽  
Surface Area ◽  
Bet Surface Area ◽  
Lead Removal ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Naturally Occurring ◽  
27Al Mas Nmr ◽  
Modified Zeolites

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.

scholarly journals Pyrene Carboxylate Ligand Based Coordination Polymers for Microwave-Assisted Solvent-Free Cyanosilylation of Aldehydes

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Polymer ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Solvent Free ◽  
Lewis Acidity ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.

scholarly journals Toxicity and Biological Effects of Beauveria brongniartii Fe0 Nanoparticles against Spodoptera litura (Fabricius)

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 895
Author(s):  
Jing Xu ◽  
Kaihui Zhang ◽  
Andrew G. S. Cuthbertson ◽  
Cailian Du ◽  
Shaukat Ali
Keyword(s):  
Spodoptera Litura ◽  
Insect Pests ◽  
Growth Parameters ◽  
Uv Spectroscopy ◽  
Biological Effects ◽  
Fungal Treatment ◽  
Beauveria Brongniartii ◽  
Sem Images ◽  
X Ray ◽  
Infection Period

Nanotechnology has clear potential in the development of innovative insecticidal products for the biorational management of major insect pests. Metal-based nanoparticles of different microbial pest control agents have been effective against several pests. Synthesis of Beauveria brongniartii based Fe0 nanoparticles (Fe0NPs) and their bio-efficacy against Spodoptera litura was observed during this study. Beauveria brongniartii conidia were coated with Fe0NPs and characterized by applying a selection of different analytical techniques. Ultraviolet (UV) spectroscopy showed the characteristic band of surface plasmon at 430 nm; Scanning electron microscopy (SEM) images showed spherical shaped nanoparticles with a size ranging between 0.41 to 0.80 µm; Energy-dispersive X-ray (EDX) spectral analysis revealed characteristic Fe peaks at 6.5 and 7.1 Kev; the X-ray diffractogram showed three strong peaks at 2θ values of 45.72°, 64.47°, and 84.05°. The bioassay studies demonstrated that mortality of 2nd instar S. litura larvae following Fe0NPs treatment increased with increasing concentrations of Fe0NPs at different time intervals. The median lethal concentration (LC50) values of Fe0NPs against S. litura after seven days of fungal treatment was 59 ppm, whereas median survival time (LT50) values for 200 and 500 ppm concentrations of Fe0NPs against S. litura seven days post-treatment were 5.1 and 2.29 days, respectively. Beauveria brongniartii-Fe0NPs caused significant reductions in feeding and growth parameters (relative growth rate, relative consumption rate, and efficiency of conversion of ingested food) of S. litura. Beauveria brongniartii Fe0NPs induced reduction in glutathione-S-transferase activities throughout the infection period whereas activities of antioxidant enzymes decreased during later periods of infection. These findings suggest that B. brongniartii Fe0NPs can potentially be used in biorational S. litura management programs.

scholarly journals Snapshots of a Non-Canonical RdRP in Action

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1260
Author(s):  
Diego S. Ferrero ◽  
Michela Falqui ◽  
Nuria Verdaguer
Keyword(s):  
Metal Ion ◽  
Rna Viruses ◽  
Ion Binding ◽  
Genome Replication ◽  
Metal Ion Binding ◽  
Insect Virus ◽  
X Ray ◽  
Template Strand ◽  
Nucleotide Incorporation ◽  
Elongation Process

RNA viruses typically encode their own RNA-dependent RNA polymerase (RdRP) to ensure genome replication and transcription. The closed “right hand” architecture of RdRPs encircles seven conserved structural motifs (A to G) that regulate the polymerization activity. The four palm motifs, arranged in the sequential order A to D, are common to all known template dependent polynucleotide polymerases, with motifs A and C containing the catalytic aspartic acid residues. Exceptions to this design have been reported in members of the Permutotetraviridae and Birnaviridae families of positive single stranded (+ss) and double-stranded (ds) RNA viruses, respectively. In these enzymes, motif C is located upstream of motif A, displaying a permuted C–A–B–D connectivity. Here we study the details of the replication elongation process in the non-canonical RdRP of the Thosea asigna virus (TaV), an insect virus from the Permutatetraviridae family. We report the X-ray structures of three replicative complexes of the TaV polymerase obtained with an RNA template-primer in the absence and in the presence of incoming rNTPs. The structures captured different replication events and allowed to define the critical interactions involved in: (i) the positioning of the acceptor base of the template strand, (ii) the positioning of the 3’-OH group of the primer nucleotide during RNA replication and (iii) the recognition and positioning of the incoming nucleotide. Structural comparisons unveiled a closure of the active site on the RNA template-primer binding, before rNTP entry. This conformational rearrangement that also includes the repositioning of the motif A aspartate for the catalytic reaction to take place is maintained on rNTP and metal ion binding and after nucleotide incorporation, before translocation.

scholarly journals Electrospun Membranes Based on Polycaprolactone, Nano-Hydroxyapatite and Metronidazole

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 931
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Ondine Lucaciu ◽  
Petru Pascuta ◽  
Mihaela Vlassa ◽  
...  
Keyword(s):  
Fiber Diameter ◽  
Maximum Load ◽  
Guided Bone Regeneration ◽  
Attenuated Total Reflectance ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Total Reflectance ◽  
X Ray ◽  
Electrospun Membranes

The aim of this research was to develop new electrospun membranes (EMs) based on polycaprolactone (PCL) with or without metronidazole (MET)/nano-hydroxyapatite (nHAP) content. New nHAP with a mean diameter of 34 nm in length was synthesized. X-ray diffraction (XRD) and attenuated total reflectance Fourier transform infrared spectroscopy (FTIR-ATR) were used for structural characterization of precursors and EMs. The highest mechanical properties (the force at maximum load, Young’s modulus and tensile strength) were found for the PCL membranes, and these properties decreased for the other samples in the following order: 95% PCL + 5% nHAP > 80% PCL + 20% MET > 75% PCL + 5% nHAP + 20% MET. The stiffness increased with the addition of 5 wt.% nHAP. The SEM images of EMs showed randomly oriented bead-free fibers that generated a porous structure with interconnected macropores. The fiber diameter showed values between 2 and 16 µm. The fiber diameter increased with the addition of nHAP filler and decreased when MET was added. New EMs with nHAP and MET could be promising materials for guided bone regeneration or tissue engineering.

scholarly journals Multidimensional Ln-Aminophthalate Photoluminescent Coordination Polymers

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  
Keyword(s):  
Water Content ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Low Cost ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.

scholarly journals Chemically and Green Synthesized ZnO Nanoparticles Alter Key Immunological Molecules in Common Carp (Cyprinus carpio) Skin Mucus

2021 ◽  
Vol 22 (6) ◽  
pp. 3270
Author(s):  
Ghasem Rashidian ◽  
Carlo C. Lazado ◽  
Heba H. Mahboub ◽  
Ramin Mohammadi-Aloucheh ◽  
Marko D. Prokić ◽  
...  
Keyword(s):  
Common Carp ◽  
Cyprinus Carpio ◽  
Diffuse Reflectance Spectroscopy ◽  
Total Protein Content ◽  
Zno Nps ◽  
Sem Images ◽  
Skin Mucus ◽  
X Ray ◽  
Common Carp Cyprinus Carpio ◽  
Carp Cyprinus Carpio

This study was conducted to compare the effects of commercially available (C) and green synthesized (GS) Zinc oxide nanoparticles (ZnO-NPs) on immunological responses of common carp (Cyprinus carpio) skin mucus. GS ZnO-NPs were generated using Thymus pubescent and characterized by UV–vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDX). Fish (n = 150) were randomly allocated into five groups in triplicate and received a waterborne concentration of 0% (control), 25%, and 50% of LC50 96 h of commercially available (C1 and C2) and green synthesized ZnO-NPs (GS1 and GS2) for 21 days. Results from XRD displayed ZnO-NPs with 58 nm in size and UV-vis DRS, EDX, and FT-IR analysis showed that some functional groups from plant extract bonded to the surface of NPs. The SEM images showed that ZnO-NPs have conical morphology. Acute toxicity study showed a higher dose of LC5096h for green synthesized ZnO-NPs (78.9 mg.L−1) compared to the commercial source (59.95 mg.L−1). The highest activity of lysozyme and alternative complement activity (ACH50) were found in control and GS1 groups. A significant decrease in alkaline phosphatase activity (ALP) was found in C1 and C2 groups compared to other treatments. Protease activity (P) was significantly decreased in the C2 group compared to the control and GS groups. Total immunoglobulin (total Ig) content was the highest in the control. In addition, total Ig in the GS1 group was higher than GS2. The exposure to ZnO-NPs lowered total protein content in all experimental groups when compared to control. Present findings revealed lower induced immunosuppressive effects by green synthesized ZnO-NPs on key parameters of fish skin mucus.

scholarly journals Assessment of Titanate Nanolayers in Terms of Their Physicochemical and Biological Properties

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 806
Author(s):  
Michalina Ehlert ◽  
Aleksandra Radtke ◽  
Katarzyna Roszek ◽  
Tomasz Jędrzejewski ◽  
Piotr Piszczek
Keyword(s):  
Surface Modification ◽  
Substrate Surface ◽  
Biological Properties ◽  
Structure Characterization ◽  
Porous Coating ◽  
Apatite Formation ◽  
Sem Images ◽  
Energy Dispersion Spectroscopy ◽  
X Ray

The surface modification of titanium substrates and its alloys in order to improve their osseointegration properties is one of widely studied issues related to the design and production of modern orthopedic and dental implants. In this paper, we discuss the results concerning Ti6Al4V substrate surface modification by (a) alkaline treatment with a 7 M NaOH solution, and (b) production of a porous coating (anodic oxidation with the use of potential U = 5 V) and then treating its surface in the abovementioned alkaline solution. We compared the apatite-forming ability of unmodified and surface-modified titanium alloy in simulated body fluid (SBF) for 1–4 weeks. Analysis of the X-ray diffraction patterns of synthesized coatings allowed their structure characterization before and after immersing in SBF. The obtained nanolayers were studied using Raman spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and scanning electron microscopy (SEM) images. Elemental analysis was carried out using X-ray energy dispersion spectroscopy (SEM EDX). Wettability and biointegration activity (on the basis of the degree of integration of MG-63 osteoblast-like cells, L929 fibroblasts, and adipose-derived mesenchymal stem cells cultured in vitro on the sample surface) were also evaluated. The obtained results proved that the surfaces of Ti6Al4V and Ti6Al4V covered by TiO2 nanoporous coatings, which were modified by titanate layers, promote apatite formation in the environment of body fluids and possess optimal biointegration properties for fibroblasts and osteoblasts.

scholarly journals The Study of Magnetic Properties for Non-Magnetic Ions Doped BiFeO3

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4061
Author(s):  
Yongtao Li ◽  
Liqing Liu ◽  
Dehao Wang ◽  
Hongguang Zhang ◽  
Xuemin He ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Local Structure ◽  
Metal Ion ◽  
Single Phase ◽  
Sol Gel ◽  
X Ray ◽  
Co Doping ◽  
Magnetic Ions ◽  
X Ray Absorption ◽  
Fe Ions

BiFeO3 is considered as a single phase multiferroic. However, its magnetism is very weak. We study the magnetic properties of BiFeO3 by Cu and (Cu, Zn). Polycrystalline samples Bi(Fe0.95Cu0.05)O3 and BiFe0.95(Zn0.025Cu0.025)O3 are prepared by the sol-gel method. The magnetic properties of BiFe0.95(Zn0.025Cu0.025)O3 are greater than that of BiFeO3 and Bi(Fe0.95Cu0.05)O3. The analyses of X-ray absorption fine structure data show that the doped Cu atoms well occupy the sites of the Fe atoms. X-ray absorption near edge spectra data confirm that the valence state of Fe ions does not change. Cu and Zn metal ion co-doping has no impact on the local structure of the Fe and Bi atoms. The modification of magnetism by doping Zn can be understood by the view of the occupation site of non-magnetically active Zn2+.

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