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Electron paramagnetic resonance (EPR) data on manganese-substituted tin dioxide (Mn:SnO) samples are presented. The investigations show that the observed EPR spectra arise from three different contributions of Mn ions viz., (1) interstitial Mn ions situated on the particle surfaces (2) isolated Mn ions located substitutionally at Sn sites and (3) the Mn ions which substitute for Sn ions in SnO lattice. The effect of the dopant concentration on EPR spectra is also presented and discussed. [ABSTRACT FROM AUTHOR]

Structural, morphological and EPR investigations on Zn1-xMnxO fine ceramics (x = 0.01 and 0.03) are reported. XRD studies reveal a wurzite-type structure, while the formation of ZnMnO3 secondary phase was evidenced only for x = 0.03 sample. Both EPR spectra present a hyperfine structure specific to isolated Mn2+ ions and for the sample x = 0.03, a new quite broad resonance line arises, which could be attributed to a ferromagnetic phase. [ABSTRACT FROM AUTHOR]

Electron magnetic resonance (EMR) investigations of SnFeO ( x = 0.07) powders annealed at different temperatures are reported. EMR spectra show the presence of both the isolated paramagnetic Fe ions incorporated into the SnO lattice and a ferromagnetically ordered component. By increasing the annealing temperature, the EMR spectrum attributed to the ferromagnetically coupled Fe ions diminishes probably due to the migration of Fe ions and the formation of the second phase. The presence of the second phase was evidenced by X-ray diffraction measurements. [ABSTRACT FROM AUTHOR]

We report an electron paramagnetic resonance (EPR) investigation of the spin dynamics in the paramagnetic regime of nanosized La0.67Ca0.33MnO3−δ manganites. The temperature dependences of the EPR line width and integral intensity have been analyzed in terms of the bottlenecked spin relaxation and small polaron hopping scenarios. The exchange coupling integral between Mn3+ and Mn4+ ions and the polaron activation energy decrease with the reduction of grain size. A discussion is given concerning the factors which could explain the observed changes. [ABSTRACT FROM AUTHOR]

We report an electron paramagnetic resonance (EPR) investigation of the spin dynamics in the paramagnetic regime of the colossal magnetoresistive manganites La2/3Ca1/3Mn1− x Me x O3 (Me=Al, In; x≤0.05). The temperature dependences of the EPR linewidth and integral intensity have been analyzed in terms of the bottleneck spin relaxation and small-polaron hopping models. The exchange coupling integral between Mn3+ and Mn4+ ions and the polaron activation energy decrease with increasing doping level. A discussion is given concerning the factors which could explain the observed changes. [ABSTRACT FROM AUTHOR]

Highlights: [•] Sn1 − x V x O2 nanoparticles annealed at different temperatures were prepared. [•] The crystallites sizes were estimated by XRD. [•] V2O5 phase was evidenced by Raman spectroscopy in samples annealed at 800, 1000°C. [•] A ferromagnetic behaviour for the undoped SnO2 sample was obtained. [•] The ferromagnetism is enhanced by doping with V ions and annealing at 450°C. [ABSTRACT FROM AUTHOR]

Abstract: This article reports the effects of the annealing temperature on the structural, morphological and spin dynamic properties of SnO2 samples doped with 0.005Mn. The samples were annealed at 400, 600, 700 and 800°C and analyzed by XRD, TEM, XPS and EPR spectroscopy. The XRD spectra show that the average crystallite size increases with the increase of the annealing temperature. The particles size and morphology were characterized by TEM microscopy. The valence bands of Mn were investigated by measuring the XPS spectra of Mn 2p core-level doublet. Regardless of the annealing temperature, the observed EPR spectra are due to (i) Mn2+ ions either interstitially situated on the particle surfaces or isolated ones located substitutionally at Sn sites and (ii) Mn4+ ions which substitute for Sn4+ in SnO2 lattice. The effects of the annealing temperature on the relative fractions of Mn2+ and Mn4+ ions are presented and discussed. In Sn1− x Mn x O2 (x =0.005) sample annealed at 400°C, a FMR line was identified and attributed to a ferromagnetic phase. [Copyright &y& Elsevier]

Background: Angiographic parameters can facilitate the risk stratification of coronary lesions but remain insufficient in the prediction of future myocardial infarction (MI)., Aims: We compared the ability of humans, angiographic parameters and deep learning (DL) to predict the lesion that would be responsible for a future MI in a population of patients with non-significant CAD at baseline., Methods: We retrospectively included patients who underwent invasive coronary angiography (ICA) for MI, in whom a previous angiogram had been performed within 5 years. The ability of human visual assessment, diameter stenosis, area stenosis, quantitative flow ratio (QFR) and DL to predict the future culprit lesion (FCL) was compared., Results: In total, 746 cropped ICA images of FCL and non-culprit lesions (NCL) were analysed. Predictive models for each modality were developed in a training set before validation in a test set. DL exhibited the best predictive performance with an area under the curve of 0.81, compared with diameter stenosis (0.62, p=0.04), area stenosis (0.58, p=0.05) and QFR (0.67, p=0.13). DL exhibited a significant net reclassification improvement (NRI) compared with area stenosis (0.75, p=0.03) and QFR (0.95, p=0.01), and a positive nonsignificant NRI when compared with diameter stenosis. Among all models, DL demonstrated the highest accuracy (0.78) followed by QFR (0.70) and area stenosis (0.68). Predictions based on human visual assessment and diameter stenosis had the lowest accuracy (0.58)., Conclusion: In this feasibility study, DL outperformed human visual assessment and established angiographic parameters in the prediction of FCLs. Larger studies are now required to confirm this finding., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The purpose of this study was to compare the polyphenol profile of different Rosemary (Rosmarinus officinalis) extracts obtained from dry and fresh herb and the evaluation of their antioxidant effect. There were studied the polyphenols from hydroalcoholic extracts (1:5- dry plant:solvent) obtained from fresh respectively dry plant and the gemmotherapic extract obtained from fresh plant (1:20- dry plant: solvent). The polyphenol profile was evaluated by UV-Vis spectrophotometry, TLC and HPLC. The total polyphenol respectively flavonoids content were determined by UV-V is spectrophotometry. The antioxidant effect was evaluated by DPPH, ABTS, FRAP, CUPRAC and silver nanoparticle (SNP) methods. The hydroalcoholic extract obtained from fresh plant contains the highest concentration of total polyphenols, (0.601mg/ml rosmarinic acid), total flavonoids, (0.270mg/ml luteoline) and rosmarinic acid (0.350 mg/ml). The less concentrated is the gemmotherapic extract, but also the extraction ratio is higher than the hydroalcoholic extracts. The high content in polyphenols of the mentioned hydroalcoholic extract was confirmed by highest values of antioxidant activity: 39.1ml (DPPH), 7.7 ml (ABTS), 698mM ET/100 ml (FRAP), 1947 mM ET/100 ml (CUPRAC), 4570mM ET/100 ml (SNP). These differences in the polyphenols profiles show the importance of use the fresh plants for obtaining the good quality extracts.

The purpose of our study was to identify the phenolic substances of two varieties of Chrysanthemum balsamita (balsamita and tanacetoides) and to measure the overall antioxidant activity. The phenolic compounds were determined by HPLC. The evaluation of the polyphenolic content was performed by colorimetric analysis. The antioxidant activity was measured by three in vitro assay models: the DPPH, the silver nanoparticles antioxidant capacity (SNPAC) and EPR radical detection. Using HPLC-MS analysis, phenolic acids, flavonoids and flavonoid aglycone were detected. The highest antioxidant activity was showed by Chrysanthemum balsamita var. balsamita, while the lowest for the Chrysanthemum balsamita var. tanacetoides extract, in accord with the polyphenolic content. The results show that Chrysanthemum balsamita var. balsamita might be a source of antioxidant flavonoids, especially rutin and isoquercitrin.

In the present study, six indigenous species of Lamiaceae family (Origanum vulgare L., Melissa officinalis L., Rosmarinus officinalis L., Ocimum basilicum L., Salvia officinalis L. and Hyssopus officinalis L.), have been analyzed to assess the rosmarinic acid, phenyl propane derivatives and polyphenolic contents and their antioxidant and antimicrobial potential. HPLC-MS method has been used for the analysis ofrosmarinicacid. The phenyl propane derivatives and total phenolic contents were determined using spectrophotometric method. The ethanolic extracts were screened for antioxidant activities by DPPH radical scavenging, HAPX (hemoglobin ascorbate per oxidase activity inhibition), and EPR (electron paramagnetic resonance) methods. The ethanolic extracts revealed the presence of rosmarinic acid in the largest amount in O. vulgare (12.40mg/g) and in the lowest in R. officinalis (1.33 mg/g). O. vulgare extracts exhibited the highest antioxidant capacity, in line with the rosmarinic acid and polyphenolic contents. The antimicrobial testing showed a significant activity against L. monocytogenes, S. aureus and C. albicans for all six extracts.

The purpose of this research was to bring new data regarding the phenolic composition and the antioxidant activity of L. barbarum L. and L. chinense Mill. leaves. The determination of the main polyphenolic compounds was performed using a HPLC-UV-MS method. The dominant compound found for both species was rutin, with its highest amount registered in L. chinense (24141.90±21.3 μ/g plant material) leaves. Among the flavonoidic aglycones, quercetin was found in both samples, being quantified in a higher amount in L. chinense. In the antioxidant assays, both extracts exhibited important antioxidant activities, as witnessed by the three methods, both correlated with their total polyphenolic content.

The aim of this paper was to evaluate the antioxidant and antimicrobial activities and the polyphenolic content of Schisandra chinensis (Turcz.) Baill. leaves and fruits. The leaves are an important source of flavonoids (35.10 ± 1.23 mg RE/g plant material). Qualitative and quantitative analyses of the polyphenolic compounds were achieved using a HPLC-UV-MS method. The main flavonoid from the leaves was isoquercitrin (2486.18 ± 5.72 μg/g plant material), followed by quercitrin (1645.14 ± 2.12 μg/g plant material). Regarding the fruit composition, the dominant compound there was rutin (13.02 ± 0.21 μg/g plant material), but comparing with the leaves, fruits can be considered a poor source of phenolic compounds. The antioxidant activity was evaluated by DPPH, TEAC, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c and EPR spectroscopic assays, revealing a better antioxidant activity for the S. chinensis leaves extract. In the antimicrobial assay, S. chinensis leaves extract showed efficient activities against the targeted bacteria, being more active than the fruits extract. The results suggest the leaves of S. chinensis as a valuable source of antioxidant compounds with significant antioxidant activity.