scholarly journals BaGdF5 Nanophosphors Doped with Different Concentrations of Eu3+ for Application in X-ray Photodynamic Therapy

2021 ◽  
Vol 22 (23) ◽  
pp. 13040
Author(s):  
Zaira Gadzhimagomedova ◽  
Vladimir Polyakov ◽  
Ilia Pankin ◽  
Vera Butova ◽  
Daria Kirsanova ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Photodynamic Therapy ◽  
Nitrogen Adsorption ◽  
Shell Morphology ◽  
X Rays ◽  
Amorphous Sio2 ◽  
Shell Size ◽  
X Ray ◽  
Efficient Alternative ◽  
Average Size

X-ray photodynamic therapy (XPDT) has been recently considered as an efficient alternative to conventional radiotherapy of malignant tissues. Nanocomposites for XPDT typically consist of two components—a nanophosphor which re-emits X-rays into visible light that in turn is absorbed by the second component, a photosensitizer, for further generation of reactive oxygen species. In this study, BaGdF5 nanophosphors doped with different Eu:Gd ratios in the range from 0.01 to 0.50 were synthesized by the microwave route. According to transmission electron microscopy (TEM), the average size of nanophosphors was ~12 nm. Furthermore, different coatings with amorphous SiO2 and citrates were systematically studied. Micro-CT imaging demonstrated superior X-ray attenuation and sufficient contrast in the liver and the spleen after intravenous injection of citric acid-coated nanoparticles. In case of the SiO2 surface, post-treatment core–shell morphology was verified via TEM and the possibility of tunable shell size was reported. Nitrogen adsorption/desorption analysis revealed mesoporous SiO2 formation characterized by the slit-shaped type of pores that should be accessible for methylene blue photosensitizer molecules. It was shown that SiO2 coating subsequently facilitates methylene blue conjugation and results in the formation of the BaGdF5: 10% Eu3+@SiO2@MB nanocomposite as a promising candidate for application in XPDT.

scholarly journals Synchrotron radiation X-ray tomographic microscopy (SRXTM) of brachiopod shell interiors for taxonomy: Preliminary report

2010 ◽  
pp. 109-117 ◽  
Author(s):  
Neda Motchurova-Dekova ◽  
David Harper
Keyword(s):  
Synchrotron Radiation ◽  
Three Dimensional ◽  
X Rays ◽  
X Ray ◽  
Fine Grained ◽  
Internal Structures ◽  
Efficient Alternative ◽  
Micro Tomography ◽  
Light Beams ◽  
Non Destructive

Synchrotron radiation X-ray tomographic microscopy (SRXTM) is a non-destructive technique for the investigation and visualization of the internal features of solid opaque objects, which allows reconstruction of a complete three-dimensional image of internal structures by recording of the differences in the effects on the passage of waves of energy reacting with those structures. Contrary to X-rays, produced in a conventional X-ray tube, the intense synchrotron light beams are sharply focused like a laser beam. We report encouraging results from the use of SRXTM for purely taxonomic purposes in brachiopods: an attempt to find a non-destructive and more efficient alternative to serial sectioning and several other methods of dissection together with the non-destructive method of X-ray computerised micro-tomography. Two brachiopod samples were investigated using SRXTM. In ?Rhynchonella? flustracea it was possible to visualise the 3D shape of the crura and dental plates. In Terebratulina imbricata it was possible to reveal the form of the brachidium. It is encouraging that we have obtained such promising results using SRXTM with our very first two fortuitous samples, which had respectively fine-grained limestone and marl as infilling sediment, in contrast to the discouraging results communicated to us by some colleagues who have tested specimens with such infillings using X-ray micro-tomography. In future the holotypes, rare museum specimens or delicate Recent material may be preferentially subjected to this mode of analysis.

scholarly journals Effects of Nanoparticle Size and Radiation Energy on Copper-Cysteamine Nanoparticles for X-ray Induced Photodynamic Therapy

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1087
Author(s):  
Bindeshwar Sah ◽  
Jing Wu ◽  
Adam Vanasse ◽  
Nil Kanatha Pandey ◽  
Lalit Chudal ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Reactive Oxygen Species Production ◽  
Radiation Energy ◽  
Nanoparticle Size ◽  
Oxygen Species ◽  
X Rays ◽  
Therapy Outcomes ◽  
X Ray ◽  
Average Size ◽  
Species Production

The Copper-cysteamine (Cu-Cy) nanoparticle is a novel sensitizer with a potential to increase the effectiveness of radiation therapy for cancer treatment. In this work, the effect of nanoparticle size and the energy of X-rays on the effectiveness of radiation therapy are investigated. The effect of the particle size on their performance is very complicated. The nanoparticles with an average size of 300 nm have the most intense photoluminescence, the nanoparticles with the average size of 100 nm have the most reactive oxygen species production upon X-ray irradiation, while the nanoparticles with the average size of 40 nm have the best outcome in the tumor suppression in mice upon X-ray irradiation. For energy, 90 kVp radiation resulted in smaller tumor sizes than 250 kVp or 350 kVp radiation energies. Overall, knowledge of the effect of nanoparticle size and radiation energy on radiation therapy outcomes could be useful for future applications of Cu-Cy nanoparticles.

Investigation of ZnO/CuO/Nanographene Platelets Composites Catalyst for the Degradation of Methylene Blue from Aqueous Solution

2016 ◽  
Vol 864 ◽  
pp. 117-122 ◽  
Author(s):  
Hesni Shabrany ◽  
Hendry Tju ◽  
Ardiansyah Taufik ◽  
Rosari Saleh
Keyword(s):  
Aqueous Solution ◽  
Methylene Blue ◽  
Catalytic Activity ◽  
Visible Light ◽  
Sol Gel ◽  
Nitrogen Adsorption ◽  
Ultrasound Irradiation ◽  
X Ray Diffraction ◽  
X Ray

This paper discusses the catalytic activity of ZnO/CuO/nanographene platelets composites under visible light and ultrasound irradiation separately. The ZnO/CuO/nanographene platelets composites were synthesized using a sol-gel method. X-ray diffraction and nitrogen adsorption spectroscopy were employed to investigate the structural and surface area of the catalyst. The catalytic activity results showed that the presence of nanographene platelets in ZnO/CuO nanocomposites improved its efficiency in degrading methylene blue. A scavenger method was also used to understand the role of charged carriers and the active radical involved in the catalytic activity.

scholarly journals Reciprocal Space Mapping of Epitaxial Materials Using Position-Sensitive X-ray Detection

1994 ◽  
Vol 38 ◽  
pp. 201-213 ◽  
Author(s):  
S. R. Lee ◽  
B. L. Doyle ◽  
T. J. Drummond ◽  
J. W. Medernach ◽  
P. Schneider
Keyword(s):  
Space Mapping ◽  
Reciprocal Space ◽  
X Rays ◽  
X Ray Diffraction ◽  
Reciprocal Space Mapping ◽  
Rocking Curve ◽  
X Ray ◽  
Position Sensitive ◽  
Average Size ◽  
Short Time

Abstract Reciprocal space mapping can be efficiently carried out using a position-sensitive x-ray detector (PSD) coupled to a traditional double-axis diffractometer. The PSD offers parallel measurement of the total scattering angle of all diffracted x-rays during a single rocking-curve scan. As a result, a two-dimensional reciprocal space map can be made in a very short time similar to that of a one-dimensional rocking-curve scan. Fast, efficient reciprocal space mapping offers numerous routine advantages to the x-ray diffraction analyst. Some of these advantages arc the explicit differentiation of lattice strain from crystal orientation effects in strain-relaxed heteroepitaxial layers; the nondestructive characterization of the size, shape and orientation of nanocrystalline domains in ordered-alloy epilayers; and the ability to measure the average size and shape of voids in porous epilayers. Here, the PSD-based diffractometer is described, and specific examples clearly illustrating the advantages of complete reciprocal space analysis are presented.

Adsorption of Methylene Blue by Hydroxyl-Aluminum Pillared Montmorillonite

2020 ◽  
Vol 42 (4) ◽  
pp. 550-550
Author(s):  
Houria Rezala Houria Rezala ◽  
Houda Douba Houda Douba ◽  
Horiya Boukhatem and Amaya Romero Horiya Boukhatem and Amaya Romero
Keyword(s):  
Methylene Blue ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Basal Spacing ◽  
Solution Ph ◽  
X Ray ◽  
Pillared Montmorillonite ◽  
Pseudo Second Order ◽  
Adsorption Desorption ◽  
Kinetics And Isotherms

A purified raw montmorillonite and hydroxy-aluminum pillared montmorillonite have been prepared from a natural bentonite from Maghnia, Algeria. These materials have been analyzed by X-ray fluorescence spectroscopy, X-ray diffraction, Infrared spectroscopy and nitrogen adsorption-desorption measurement. The pillared montmorillonite provided a certain increase of interlayer basal spacing and BET surface area and consequently the improvement of its capacities adsorption and decolorization of Methylene Blue. The adsorption properties of these materials were studied as a function of contact time, solution pH, initial Methylene Blue concentration and temperature. The adsorption kinetics and isotherms were well fitted by pseudo-second order and Freundlich models, respectively. In addition to that, thermodynamic studies showed an exothermic and a spontaneous process.

scholarly journals X-ray induced photodynamic therapy with copper-cysteamine nanoparticles in mice tumors

2019 ◽  
Vol 116 (34) ◽  
pp. 16823-16828 ◽  
Author(s):  
Samana Shrestha ◽  
Jing Wu ◽  
Bindeshwar Sah ◽  
Adam Vanasse ◽  
Leon N Cooper ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Treatment Method ◽  
The Body ◽  
Target Cells ◽  
X Rays ◽  
X Ray ◽  
Mouse Tumors ◽  
Study Results ◽  
New Type

Photodynamic therapy (PDT), a treatment that uses a photosensitizer, molecular oxygen, and light to kill target cells, is a promising cancer treatment method. However, a limitation of PDT is its dependence on light that is not highly penetrating, precluding the treatment of tumors located deep in the body. Copper-cysteamine nanoparticles are a new type of photosensitizer that can generate cytotoxic singlet oxygen molecules upon activation by X-rays. In this paper, we report on the use of copper-cysteamine nanoparticles, designed to be targeted to tumors, for X-ray–induced PDT. In an in vivo study, results show a statistically significant reduction in tumor size under X-ray activation of pH-low insertion peptide–conjugated, copper-cysteamine nanoparticles in mouse tumors. This work confirms the effectiveness of copper-cysteamine nanoparticles as a photosensitizer when activated by radiation and suggests that these Cu-Cy nanoparticles may be good candidates for PDT in deeply seated tumors when combined with X-rays and conjugated to a tumor-targeting molecule.

Phase separation in gel-derived materials, separation and crystallization of SnO2 within an amorphous SiO2 matrix

1992 ◽  
Vol 7 (2) ◽  
pp. 435-443 ◽  
Author(s):  
R. Dal Maschio ◽  
S. Dirè ◽  
G. Carturan ◽  
S. Enzo ◽  
L. Battezzati
Keyword(s):  
Surface Segregation ◽  
Primary Crystallization ◽  
Amorphous Sio2 ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Two Phases ◽  
Average Size ◽  
Ray Scattering

On heating a gel of composition 33.5SnO2−66.5SiO2 (wt. %) up to 1050 °C, SnO2 crystallization occurred with different mechanisms according to thermal treatments. Thermal analysis, SAXS (Small Angle X-Ray Scattering), WAXS (Wide Angle X-Ray Scattering), and TEM (Transmission Electron Microscopy) results obtained for samples treated at different temperatures demonstrated that the SnO2 load is divided into two moieties, one composed of isolated SnO2 particles suitable for primary crystallization yielding crystallites with 4.0 nm of average size; the other, being dissolved in SiO2, remains in the amorphous SiO2/SnO2 solid solution up to the highest temperature. The presence of these two phases accounts for SnO2 surface segregation at the expense of the SnO2 concentration of neighboring outer layers and the independence of apparent density on temperature.

Evolution of shell apertural barriers in viviparous land snails (Gastropoda: Pulmonata: Clausiliidae)

2014 ◽  
Vol 92 (3) ◽  
pp. 205-213 ◽  
Author(s):  
A. Sulikowska-Drozd ◽  
M. Walczak ◽  
M. Binkowski
Keyword(s):  
Reproductive Strategies ◽  
Three Dimensional ◽  
Land Snails ◽  
Shell Morphology ◽  
Shell Size ◽  
X Ray ◽  
Egg Retention ◽  
Embryonic Shell ◽  
Selective Forces ◽  
Size At Birth

Apertural barriers in the snail shell were frequently associated with adaptation against predators or with reducing water loss. Yet formation of teeth occluding the aperture is costly and potentially precludes life-bearing reproduction. In viviparous species, a trade-off between the shell aperture size and the embryo shell size at birth is expected. This hypothesis was tested in clausiliids, land snails with strong apertural barriers, that displayed a range of reproductive strategies (oviparity, egg retention, viviparity). We assessed their three-dimensional internal shell morphology by means of X-ray microcomputed tomography (XMT). The data were later analysed with a specially designed algorithm that mimics the movement of the spherical embryonic shell in the lumen of the parental shell. It appeared that viviparous reproduction required the widening of the passage through the ultimate whorl, but that did not necessarily lead to a reduction of apertural barriers. This provides an example of evolutionary compromise between enhanced fitness of the offspring owing to a long gestation period and survival of the parent. Clausiliids might be selected for viviparity only if other selective forces were released, e.g., in areas where desiccation was not a major threat. This hypothesis is in congruence with the distribution of viviparous clausiliids in Europe.

scholarly journals Biogenic Gold Nanoparticles Decrease Methylene Blue Photobleaching and Enhance Antimicrobial Photodynamic Therapy

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 623
Author(s):  
Irena Maliszewska ◽  
Ewelina Wanarska ◽  
Alex C. Thompson ◽  
Ifor D. W. Samuel ◽  
Katarzyna Matczyszyn
Keyword(s):  
Methylene Blue ◽  
Gold Nanoparticles ◽  
Photodynamic Therapy ◽  
Bactericidal Effect ◽  
Antimicrobial Photodynamic Therapy ◽  
Plasmon Band ◽  
Escherichia Coli Bacteria ◽  
Average Size ◽  
20 Nm ◽  
Nanoparticle Sizes

Antibiotic resistance is a growing concern that is driving the exploration of alternative ways of killing bacteria. Here we show that gold nanoparticles synthesized by the mycelium of Mucor plumbeus are an effective medium for antimicrobial photodynamic therapy (PDT). These particles are spherical in shape, uniformly distributed without any significant agglomeration, and show a single plasmon band at 522–523 nm. The nanoparticle sizes range from 13 to 25 nm, and possess an average size of 17 ± 4 nm. In PDT, light (from a source consisting of nine LEDs with a peak wavelength of 640 nm and FWMH 20 nm arranged in a 3 × 3 array), a photosensitiser (methylene blue), and oxygen are used to kill undesired cells. We show that the biogenic nanoparticles enhance the effectiveness of the photosensitiser, methylene blue, and so can be used to kill both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The enhanced effectiveness means that we could kill these bacteria with a simple, small LED-based light source. We show that the biogenic gold nanoparticles prevent fast photobleaching, thereby enhancing the photoactivity of the methylene blue (MB) molecules and their bactericidal effect.

scholarly journals The Rare-Earth Elements Doping of BaGdF5 Nanophosphors for X-ray Photodynamic Therapy

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3212
Author(s):  
Daria Kirsanova ◽  
Vladimir Polyakov ◽  
Vera Butova ◽  
Peter Zolotukhin ◽  
Anna Belanova ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Photodynamic Therapy ◽  
Rare Earth ◽  
Reactive Oxygen Species Generation ◽  
The Body ◽  
Oxygen Species ◽  
X Rays ◽  
X Ray ◽  
Optical Luminescence ◽  
Luminescence Characteristics

It is known that the initiation of photodynamic therapy (PDT) in deep-seated tumors requires the use of X-rays to activate the reactive oxygen species generation in deep tissues. The aim of this paper is to synthesize X-ray nanophosphors and analyze their structural and luminescence characteristics to push the PDT process deep into the body. The article deals with BaGdF5:Eu3+, BaGdF5:Sm3+, and BaGdF5:Tb3+ nanophosphors synthesized using microwave synthesis. It is found that the nanoparticles are biocompatible and have sizes 5–17 nm. However, according to the analysis of X-ray excited optical luminescence, BaGdF5:Sm3+ nanophosphors will not be effective for treating deep-seated tumors. Thus, BaGdF5:Eu3+ and BaGdF5:Tb3+ nanoparticles meet the requirements for the subsequent production of nanocomposites based on them that can be used in X-ray photodynamic therapy.

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