Evaluation of strontium aluminate phosphorescent effect on blood as potential light source for phototherapy

Phototherapy has shown its effect on cell stimulation and inhibition based on Arndt-Schulz model. Even though this therapeutic method has apparent effect, but it has limitations for epithelial application due to limitations on light penetration. Hence, with the ideology of fully overcoming this limitation, phosphorescent powder (strontium aluminate) is proposed as the potential light source that emitting photon from inside the body for phototherapy purposes. The strontium aluminate powder used in the experiment has the highest peak absorption at wavelength around 650 nm and lowest at around 350 nm. According to FESEM images, the powder has the particle size varies from 10 to 50 μm at cubic phase. The assessment is done by studying the effect on erythrocyte after blood plasma is irradiated by strontium aluminate powder’s photon. The powder luminesces with a maximum at 491.5 nm when pumped with 473 nm laser at 100 mW in fixed amount of 0.005±0.001 g. Later, it is mixed with centrifuged blood plasma for a predetermined time period (5, 10, 15, and 20 minutes). From this study, it shows that 5 minutes irradiation is the optimum period for erythrocyte in term of morphology enhancement and increase of UV-visible absorption spectrum with at least 21% in comparing with control blood. While the significant increment located at wavelengths 340 nm and 414 nm with both increased by 54% and 41%, respectively. However, for 10 minutes and beyond, the irradiation leads to morphology deterioration while the UV-visible spectrum decrement starts at 15 minutes and beyond. In conjunction, a comparison between blood plasma that either interacted with powder emitting photon or powder with no emission shows that photon emission plays a role in the phototherapy effect.

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Photoactive amphiphiles for the assembly of supramolecular architectures

Faraday Discussions ◽

10.1039/c5fd00081e ◽

2015 ◽

Vol 185 ◽

pp. 471-479 ◽

Cited By ~ 3

Author(s):

B. P. Jarman ◽

F. Cucinotta

Keyword(s):

Visible Spectrum ◽

Solid Materials ◽

Visible Absorption ◽

Optical Components ◽

Absorption And Emission ◽

X Ray ◽

Supramolecular Architectures ◽

Uv Visible ◽

Absorption And Emission Spectroscopy ◽

Molecular Organisation

The presented study reports the use of photoactive templating structures for the design of porous frameworks with built-in optical functionalities. The materials have been synthesised and characterised using powder X-ray diffractometry, UV-visible absorption and emission spectroscopy. The latter shows that, by varying the relative amount of an amphiphilic chromophore in the micellar templates, it is possible to tune the light absorption and emission properties over the visible spectrum, by means of controlling the molecular organisation and the excitonic coupling of aggregated species. This enables versatile solid materials that can be used as optical components for light-harvesting and converting systems to be obtained .

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Gas phase spectra of HOBr and Br2O and their atmospheric significance

Annales Geophysicae ◽

10.1007/s00585-996-0468-x ◽

1996 ◽

Vol 14 (4) ◽

pp. 468-475 ◽

Cited By ~ 1

Author(s):

B. Deters ◽

J. P. Burrows ◽

S. Himmelmann ◽

C. Blindauer

Keyword(s):

Gas Phase ◽

Lower Stratosphere ◽

Strong Dependence ◽

Visible Spectrum ◽

Visible Absorption ◽

Atmospheric Lifetime ◽

Low Latitudes ◽

Potential Reservoir ◽

Uv Visible ◽

Phase Spectra

Abstract. The HOBr molecule is a potential reservoir of Br compounds in the atmosphere. In this work, the UV-visible spectrum of HOBr was measured over the range 242–400 nm. Its absorption consists of two maxima at 280 nm (σmax=2.7±0.4×10–19 cm2 molecules–1) and 355 nm (σmax=7.0±1.1×10–20 cm2 molecules–1), respectively, where the error is ±1Σ. Atmospheric photolysis lifetime calculations for HOBr in the lower stratosphere have been made using the PHOTOGT model. The results show a strong dependence on the solar zenith angle (SZA) implying a longer lifetime at high latitudes and a relatively short lifetime at low latitudes for example 714 s (albedo of 25%, SZA of 20° and an altitude of 17 km), and 3226 s (albedo of 25%, SZA of 88° and an altitude of 17 km). The UV-visible absorption spectrum of Br2O, which is an intermediate in the preparation, used in this study and is together with H2O in equilibrium with HOBr, was measured from 205 to 450 nm. The spectrum shows a maximum at 315 nm (σmax=2.3±0.3×10–18 cm2 molecules–1) with a shoulder at 355 nm. From the results of the atmospheric lifetime calculations for Br2O, it is clear that this molecule has a short stratospheric lifetime and is not likely to have a large daytime concentration, for example, 20 s (albedo of 25%, SZA of 20° and an altitude of 17 km), and 83 s (albedo and 25%, SZA of 88° and an altitude of 17 km).

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Its Optical Property and Characterization of Silver Antimony Sulfide Nanostructured Clusters Synthesized Using a Facile Wet Chemical Route

Materials Science Forum ◽

10.4028/www.scientific.net/msf.916.55 ◽

2018 ◽

Vol 916 ◽

pp. 55-59

Author(s):

Eksuree Saksornchai ◽

Jutarat Kavinchan

Keyword(s):

Cubic Phase ◽

Chemical Route ◽

Visible Absorption ◽

Direct Band Gap ◽

Antimony Sulfide ◽

Direct Band ◽

Wet Chemical ◽

Wet Chemical Route ◽

Uv Visible

Cubic phase of silver antimony sulfide (AgSbS2) nanostructures were successfully synthesized from silver nitrate (AgNO3), antimony acetate (CH3CO2)3Sb, and sodiumthiosulphate pentahydrate (Na2S2O3.5H2O) in propylene glycol (PG) without using any surfactants or splitting agents by a facile wet chemical route at 160 OC for 30 min. The XRD, SEM and TEM reveal AgSbS2 nanostructures forming the clusters. Due to the UV-visible absorption shows its direct band gap, is 1.80 eV, AgSbS2 is found to be the excellent material for the solar energy converters. And the possible formation of AgSbS2 nanostructured cluster was also discussed.

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Yellow Emissive Tris(8-hydroxyquinoline) Aluminum by the Incorporation of ZnO Quantum Dots for OLED Applications

Micromachines ◽

10.3390/mi12101173 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1173

Author(s):

Aya Hekmet Makki ◽

Si-Hyun Park

Keyword(s):

Quantum Dots ◽

Zinc Oxide ◽

Visible Spectrum ◽

Organic Light Emitting Diodes ◽

Yellow Emission ◽

X Ray Diffraction ◽

Visible Absorption ◽

Light Emitting ◽

Emission Color ◽

Uv Visible

Tris(8-hydroxyquinoline) aluminum complexes are of significant interest because of their remarkable optical and electrical properties, both as an emissive layer and electron injection layer. They emit light in the blue and green ranges of the visible spectrum, so for white organic light emitting diodes (OLEDs), yellow emission is required as well. In this study, we propose the use of zinc oxide quantum dots to tune the emission color of the complex while maintaining its luminous efficiency. Hence, tris(8-hydroxyquinoline) aluminum-zinc oxide nanohybrids with different zinc oxide quantum dots concentrations (10, 20, or 30 wt.%) were synthesized. The structural properties were characterized using powder X-ray diffraction analysis, while the composition and optical characteristics were characterized by Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, and photoluminescence emission spectroscopy. The results show that increased levels of zinc oxide quantum dots lead to a decrease in crystallinity, double hump emission and a slight red shift in emission peaks. Also, at 20 and 30 wt.% of zinc oxide quantum dots concentrations, yellow emission was observed.

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Liquid-liquid extraction of succinate using a dicopper cryptate

10.26434/chemrxiv.11786784 ◽

2020 ◽

Author(s):

Riccardo Mobili ◽

Sonia La Cognata ◽

Francesca Merlo ◽

Andrea Speltini ◽

Massimo Boiocchi ◽

...

Keyword(s):

Aqueous Phase ◽

Visible Spectrum ◽

Tca Cycle ◽

Residual Concentration ◽

Waste Products ◽

Liquid Liquid Extraction ◽

The Tca Cycle ◽

Quantitative Extraction ◽

Uv Visible

<div> <p>The extraction of the succinate dianion from a neutral aqueous solution into dichloromethane is obtained using a lipophilic cage-like dicopper(II) complex as the extractant. The quantitative extraction exploits the high affinity of the succinate anion for the cavity of the azacryptate. The anion is effectively transferred from the aqueous phase, buffered at pH 7 with HEPES, into dichloromethane. A 1:1 extractant:anion adduct is obtained. Extraction can be easily monitored by following changes in the UV-visible spectrum of the dicopper complex in dichloromethane, and by measuring the residual concentration of succinate in the aqueous phase by HPLC−UV. Considering i) the relevance of polycarboxylates in biochemistry, as e.g. normal intermediates of the TCA cycle, ii) the relevance of dicarboxylates in the environmental field, as e.g. waste products of industrial processes, and iii) the recently discovered role of succinate and other dicarboxylates in pathophysiological processes including cancer, our results open new perspectives for research in all contexts where selective recognition, trapping and extraction of polycarboxylates is required. </p> </div>

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Magnetic Resonace–Based Attenuation Correction for Micro–Single-Photon Emission Computed Tomography

Molecular Imaging ◽

10.2310/7290.2011.00036 ◽

2012 ◽

Vol 11 (2) ◽

pp. 7290.2011.00036 ◽

Cited By ~ 4

Author(s):

Vincent Keereman ◽

Yves Fierens ◽

Christian Vanhove ◽

Tony Lahoutte ◽

Stefaan Vandenberghe

Keyword(s):

Attenuation Correction ◽

Single Photon ◽

Photon Emission ◽

The Body ◽

Emission Computed Tomography ◽

Micro Ct ◽

Mr Images ◽

Brain Scans ◽

The Brain ◽

Photon Emission Computed Tomography

Attenuation correction is necessary for quantification in micro–single-photon emission computed tomography (micro-SPECT). In general, this is done based on micro–computed tomographic (micro-CT) images. Derivation of the attenuation map from magnetic resonance (MR) images is difficult because bone and lung are invisible in conventional MR images and hence indistinguishable from air. An ultrashort echo time (UTE) sequence yields signal in bone and lungs. Micro-SPECT, micro-CT, and MR images of 18 rats were acquired. Different tracers were used: hexamethylpropyleneamine oxime (brain), dimercaptosuccinic acid (kidney), colloids (liver and spleen), and macroaggregated albumin (lung). The micro-SPECT images were reconstructed without attenuation correction, with micro-CT-based attenuation maps, and with three MR-based attenuation maps: uniform, non-UTE-MR based (air, soft tissue), and UTE-MR based (air, lung, soft tissue, bone). The average difference with the micro-CT-based reconstruction was calculated. The UTE-MR-based attenuation correction performed best, with average errors ≤ 8% in the brain scans and ≤ 3% in the body scans. It yields nonsignificant differences for the body scans. The uniform map yields errors of ≤ 6% in the body scans. No attenuation correction yields errors ≥ 15% in the brain scans and ≥ 25% in the body scans. Attenuation correction should always be performed for quantification. The feasibility of MR-based attenuation correction was shown. When accurate quantification is necessary, a UTE-MR-based attenuation correction should be used.

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Plasma radio-metabolite analysis of PET tracers for dynamic PET imaging: TLC and autoradiography

EJNMMI Research ◽

10.1186/s13550-020-00705-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Fiona Li ◽

Justin W. Hicks ◽

Lihai Yu ◽

Lise Desjardin ◽

Laura Morrison ◽

...

Keyword(s):

High Performance Liquid Chromatography ◽

Liquid Chromatography ◽

Blood Plasma ◽

Kinetic Parameters ◽

High Performance ◽

The Body ◽

Accurate Estimation ◽

Dynamic Pet ◽

Arterial Concentration ◽

In Blood Plasma

Abstract Background In molecular imaging with dynamic PET, the binding and dissociation of a targeted tracer is characterized by kinetics modeling which requires the arterial concentration of the tracer to be measured accurately. Once in the body the radiolabeled parent tracer may be subjected to hydrolysis, demethylation/dealkylation and other biochemical processes, resulting in the production and accumulation of different metabolites in blood which can be labeled with the same PET radionuclide as the parent. Since these radio-metabolites cannot be distinguished by PET scanning from the parent tracer, their contribution to the arterial concentration curve has to be removed for the accurate estimation of kinetic parameters from kinetic analysis of dynamic PET. High-performance liquid chromatography has been used to separate and measure radio-metabolites in blood plasma; however, the method is labor intensive and remains a challenge to implement for each individual patient. The purpose of this study is to develop an alternate technique based on thin layer chromatography (TLC) and a sensitive commercial autoradiography system (Beaver, Ai4R, Nantes, France) to measure radio-metabolites in blood plasma of two targeted tracers—[18F]FAZA and [18F]FEPPA, for imaging hypoxia and inflammation, respectively. Results Radioactivity as low as 17 Bq in 2 µL of pig’s plasma can be detected on the TLC plate using autoradiography. Peaks corresponding to the parent tracer and radio-metabolites could be distinguished in the line profile through each sample (n = 8) in the autoradiographic image. Significant intersubject and intra-subject variability in radio-metabolites production could be observed with both tracers. For [18F]FEPPA, 50% of plasma activity was from radio-metabolites as early as 5-min post injection, while for [18F]FAZA, significant metabolites did not appear until 50-min post. Simulation study investigating the effect of radio-metabolite in the estimation of kinetic parameters indicated that 32–400% parameter error can result without radio-metabolites correction. Conclusion TLC coupled with autoradiography is a good alternative to high-performance liquid chromatography for radio-metabolite correction. The advantages of requiring only small blood samples (~ 100 μL) and of analyzing multiple samples simultaneously, make the method suitable for individual dynamic PET studies.

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A Product Pose Tracking Paradigm Based on Deep Points Detection

Machines ◽

10.3390/machines9060112 ◽

2021 ◽

Vol 9 (6) ◽

pp. 112

Author(s):

Loukas Bampis ◽

Spyridon G. Mouroutsos ◽

Antonios Gasteratos

Keyword(s):

Neural Network ◽

Deep Neural Network ◽

Visible Spectrum ◽

The Body ◽

Autonomous Control ◽

Pose Tracking ◽

Computer Aided ◽

Manufacturing Procedure ◽

Infrared Cameras ◽

Representative Points

The paper at hand presents a novel and versatile method for tracking the pose of varying products during their manufacturing procedure. By using modern Deep Neural Network techniques based on Attention models, the most representative points to track an object can be automatically identified using its drawing. Then, during manufacturing, the body of the product is processed with Aluminum Oxide on those points, which is unobtrusive in the visible spectrum, but easily distinguishable from infrared cameras. Our proposal allows for the inclusion of Artificial Intelligence in Computer-Aided Manufacturing to assist the autonomous control of robotic handlers.

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Remarkable kinetic stability of α-thiocarbamoyl substituted 4-methoxybenzylcations

Canadian Journal of Chemistry ◽

10.1139/v98-225 ◽

1998 ◽

Vol 76 (12) ◽

pp. 1910-1915 ◽

Cited By ~ 3

Author(s):

Robert A McClelland ◽

Victoria E Licence ◽

John P Richard ◽

Kathleen B Williams ◽

Shrong-Shi Lin

Keyword(s):

Key Words ◽

Strong Interaction ◽

Rate Constants ◽

Flash Photolysis ◽

Visible Absorption ◽

Methyl Group ◽

Thioamide Group ◽

Azide Ion ◽

Uv Visible ◽

Leaving Groups

4-Methoxybenzyl cations bearing α-(N,N-dimethylcarbamoyl) and α-(N,N-dimethylthiocarbamoyl) substituents have been generated photochemically upon irradiation of precursors with pentafluorobenzoate or 4-methoxybenzoate leaving groups. The ions have been observed with flash photolysis in 40:60 acetonitrile:water and in 50:50 methanol:water, and rate constants were measured for their decay in solvent alone and for their capture by azide ion. The cations so studied and their lifetimes in 40% acetonitrile are 6, ArC+H-CONMe2, 0.6 μs; 2, ArC+H-CSNMe2, 7 ms; and 4, ArC+(CH3)-CSMe2, 6 ms, where Ar = 4-MeOC6H4. The cation 4 reacts with solvent by elimination of a proton from the α-methyl group, and the rate constant for solvent addition must be less than 1 s-1. The CSNMe2 substituted cations are 105-107-fold longer lived than analogs where the thioamide group has been replaced with an α-methyl. The UV-visible absorption spectra of these two cations also show significant differences from those of typical 4-methoxybenzyl cations. Thus, both the lifetimes and spectra point to a strong interaction of the benzylic centre with the thioamide group. Key words: flash photolysis, thiocarbamoyl stabilized carbocation, photosolvolysis.

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