Green and novel ultrasonic extraction with UHPLC-MSMS analysis of natural sweetener (Glycyrrhizic acid) from Glycyrrhiza glabra; a multifactorial mechanistic evaluation based on statistical analysis

A novel, green and eco-friendly, cost-effective, fast, and reliable high energy ultrasonication (US) extraction with UHPLC-MSMS (Ultrahigh performance liquid chromatography with mass spectrometry) quantification of Glycyrrhizic acid (GZA) is reported herein for the first time. The study provides useful insights regarding the effect of US-factors with statistical analysis and mechanisms, involved in GZA-extraction and analysis. An US-extraction method (US-MD) was developed using three levels of US factors: solvents (AC (acetone), EtOH (ethanol), H₂O (water)), time (1, 2, 3 min), amplitudes (30, 40, 50%), pulse (10/0.5, 20/0.5, 30/0.5 sec), particle sizes (0.5, 1, 1.4 mm), and temperatures (20, 30, 40 °C). The US-MD was further validated with high accuracy 98.96 ± 6.82 and r² = 0.995 whereas, an in-house analytical method (UHPLC-MSMS) was developed and validated to quantify the GZAamount. UHPLCMSMS-MD resulted in a retention time of 0.31 min with MSMS (821.400 > 351.200) in a 1 min run time whereas, UHPLCMSMS-MV showed high accuracy and precision with r² = 0.998 for GZA. Statistical analysis of K-mean clustering finalized US-set-of-factors showing optimum extract yield (mg/1mg) of 0.48 with sum (2.41 ± 014) and mean (0.27) along with a high GZA-amount (μg/mg) of 8.23 with sum (43.31 ± 2.07) and mean (4.81) for H₂O in 3 min at 40 °C using particle size (1.4 mm), amplitude (50%), and pulse (30/0.5). Large scale application of US-UHPLCMSMS confirmed the evaluation power of the method showing the order for GZA amount; Egypt > Pakistan > Syria > India > Palestine > America > Georgia > Morocco. A significant effect for US factors Vs extract yield and GZA amount was observed however, solvent*GZA-amount and extract yield*particle size were more significantly correlated compared to time*temperature*amplitude*pulse analyzed via PCA, GLM-UniANOVA, K-mean, and Pearson’s correlation (P ≤ 0.05). A combined mechanism of shear stress, macroturbulence due to acoustic cavitation and implosions, sonochemical, and sonocapillary effect were noted for the US technique producing higher extract yield and GZA amount from licorice.     

The effect of natural antioxidants,pH, and green solvents upon catechins stability during ultrasonic extraction from green tea leaves (Camellia sinensis)

BackgroundThis is a first-time report to evaluate the effect of natural antioxidants, pH, and green solvents upon catechins yield and stability during the active process of extraction from green tea leaves.MethodologyGreen solvents (model-A) augmented with piperine (PPN) and quercetin (QT) as natural antioxidants (model-B) at different pH 2–6 (model-C) were used to extract catechins from green tea leaves using an ultrasonic extraction process (USE). For quantification of catechins (EC; epicatechins, ECG; epicatechin gallate, and EGCG; epigallocatechin gallate), a green and sensitive UHPLC-MS/MS method was developed and validated.ResultsThe UHPLC-MS/MS method showed an accuracy of 98.3–102.6 % within the linearity range of 1–500 ppb for EC (m/z) 289 → 245 → 109, ECG (m/z) 441.2 → 169 → 289, and EGCG (m/z) 457.1 → 169 → 125.1. The general yield (ppb) for EC, ECG, and EGCG was observed with the ranges and sum of (N = 180) 0.06–157.80 and 6696.83, 0.04–316.93 and 12632.60 and, 0.12–584.11 and 26144.83, respectively. Model-C revealed the highest yield for catechins at the lowest pH-2 with an individual catechin yield of EGCG (584.11) > ECG (316.93) > EC (157.80) in CW2. In terms of stability, EGCG was the most unstable catechin whereas, catechins extracted in model-B exhibited more stability (%recovery of 14.70 for EC, 10.55 for ECG, and 5.36 for EGCG in BEP). Moreover, model-B showed the minimal degradation for catechins within the range of 11.81–94.64 (BEP); even the most degradable EGCG was seen with the smallest %loss of 11.81–94.64 at time 24–70 h, as compared to the loss of > 95 % in model-A and C. The ANOVA score for catechins yield was; F_11,168 = 61.06 (EC), F_11,168 = 66.53 (ECG), and F_11,168 = 48.92 (EGCG) (P = 0.00) with mean scores of (M = 94.63, SD = 25.46) for EC, (M = 194.87, SD = 51.41) ECG, and (M = 357.57, SD = 96.80) EGCG in CE2.ConclusionA significant effect on catechins yield and stability was observed with the use of natural antioxidants and lowest pH-2.     

Importance of through-plane heart motion correction for the assessment of aortic regurgitation severity using phase contrast magnetic resonance imaging

PurposeTo elucidate the influence of through-plane heart motion on the assessment of aortic regurgitation (AR) severity using phase contrast magnetic resonance imaging (PC-MRI).ApproachA patient cohort with chronic AR (n = 34) was examined with PC-MRI. The regurgitant volume (RVol) and fraction (RFrac) were extracted from the PC-MRI data before and after through-plane heart motion correction and was then used for assessment of AR severity.ResultsThe flow volume errors were strongly correlated to aortic diameter (R = 0.80, p < 0.001) with median (IQR 25%;75%): 16 (14; 17) ml for diameter>40mm, compared with 9 (7; 10) ml for normal aortic size (p < 0.001). RVol and RFrac were underestimated (uncorrected:64 ± 37 ml and 39 ± 17%; corrected:76 ± 37 ml and 44 ± 15%; p < 0.001) and ~ 20% of the patients received lower severity grade without correction.ConclusionThrough-plane heart motion introduces relevant flow volume errors, especially in patients with aortic dilatation that may result in underestimation of the severity grade in patients with chronic AR.     

Comparison of ultrasound and microwave assisted extraction of diosgenin from Trigonella foenum graceum seed

From the recent market trend, there is a huge demand for the bioactive compounds from various food matrices that could be capable enough to combat the emerging health effects in day-to-day life. Fenugreek is a well-known spice from ancient times for its medicinal and health benefits. In the present study, two methods of green extraction microwave (MAE) and ultrasound (UAE) assisted were studied in regard of extraction of fenugreek diosgenin. In this study, solvent type (acetone, ethanol, hexane and petroleum ether), solvent concentration (40, 60, 80 and 100%) and treatment time (1.5, 3.0, 4.5 and 6.0 min and 30, 40, 50 and 60 min for MAE and UAE method respectively) was varied to observe the effect of these parameters over extract yield and diosgenin content. The results of this study revealed that treatment time, type of solvent and its concentration and method adopted for extraction of diosgenin has significant effect. In relation with better yield extract and diosgenin content, the yield of fenugreek seed extract was 7.83% with MAE and 21.48% with UAE of fenugreek seed powder at 80% ethanol concentration at 6 and 60 min respectively. The content of diosgenin was observed in fenugreek seed powder extract was 35.50 mg/100 g in MAE and 40.37 mg/100 g in UAE with 80% ethanol concentration at 6 and 60 min respectively. The overall range of yield of fenugreek extract was varied from 1.04% to 32.48% and diosgenin content was 15.82 mg/100 g to 40.37 mg/100 g of fenugreek seed powder including both extraction methods. This study revealed that UAE would impose better ways for preparing fenugreek extract and observing diosgenin content from fenugreek seeds.     

Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion

Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT ₀=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ～15 (GeV/c)² (the neutrino energy over ～50 GeV) was observed.     

Ultrasound-assisted extraction,optimization, isolation,and antioxidant activity analysis of flavonoids from Astragalus membranaceus stems and leaves

Astragalus membranaceus is a medicinal and edible species in China, with a variety of biological activities. This study evaluated the reuse potential of A. membranaceus waste as a source of food antioxidants. Antioxidant and antifungal activities of flavonoids, polysaccharides, and saponins from A. membranaceus stems and leaves were evaluated. Results showed that inhibition rate of flavonoids on six tested fungi reaches 100 % at a concentration of 5 mg/mL, and the antioxidant test demonstrated satisfactory antioxidant activity. On this basis, an extremely economical ultrasonic-assisted extraction of flavonoids from A. membranaceus stems and leaves was developed and optimized via response surface methodology (RSM). Optimized conditions included an extraction time of 35 min, ethanol concentration of 75 %, liquid–solid ratio of 40 mL/g, and extraction temperature of 58 °C, in which the extraction yield of flavonoids was 22.0270 ± 2.5739 mg/g. The total flavonoids were separated and purified using activity-guided isolation technology, and frac. ccd with strong antioxidant activity were analyzed via HPLC-MS/MS. Results showed that main components are isoquercitrin and astragalin. This study can provide a potential innovative application for the development of natural food antioxidants from A. membranaceus waste.     

Three-dimensional turbo-spin-echo amide proton transfer-weighted and intravoxel incoherent motion MR imaging for type I endometrial carcinoma: Correlation with Ki-67 proliferation status

BackgroundTo evaluate 3-dimensional amide proton transfer weighted (APTw) imaging for type I endometrial carcinoma (EC), and investigate correlations of Ki-67 labelling index with APTw and intravoxel incoherent motion (IVIM) imaging.Methods54 consecutive patients suspected of endometrial lesions underwent pelvic APTw and IVIM imaging on a 3 T MR scanner. APTw values and IVIM-derived parameters (Dt, D*, f) were independently measured by two radiologists on 22 postoperative pathological confirmed of type I EC lesions. Results were compared between histological grades and Ki-67 proliferation groups. ROC analysis was performed. Pearson's correlation analysis was performed for APTw values and IVIM-derived parameters with Ki-67 labeling index.ResultsAPTw values and Dt, D*, f of all type I EC were 2.9 ± 0.1%, 0.677 ± 0.027 × 10⁻³ mm²/s, 31.801 ± 11.492 × 10⁻³ mm²/s, 0.179 ± 0.050 with inter-observer ICC 0.996, 0.850, 0.956, 0.995, respectively. APTw values of Ki-67 low-proliferation group (<30%, n = 8) were 2.5 ± 0.2%, significantly lower than the high-proliferation group (>30%, n = 14) with APTw values of 3.1 ± 0.1% (p = 0.016). Area under the curve was 0.768. APTw values of type I EC were moderately positively correlated with Ki-67 labelling index (r = 0.583, p = 0.004). There was no significant difference of Dt (p = 0.843), D* (p = 0.262), f (p = 0.553) between the two groups. No correlation was found between IVIM-derived parameters and Ki-67 labelling index (Dt, p = 0.717; D* p = 0.151; f, p = 0.153).Conclusion3D TSE APTw imaging is a feasible approach for detecting type I EC. Ki-67 labeling index positively moderately correlates with APTw not with IVIM.     

A study of the neutrino production of <Emphasis Type="Italic">φ</Emphasis> and <Emphasis Type="Italic">D</Emphasis><Stack><Subscript><Emphasis Type="Italic">s</Emphasis></Subscript><Superscript>+</Superscript></Stack> mesons

The charged current neutrino production of φ and D _s ⁺ mesons is studied, using the data obtained with the SKAT bubble chamber exposed to the Serpukhov accelerator neutrino beam. It is found that the φ production occurs predominantly in the forward hemisphere of the hadronic c.m.s. (at x _F > 0, x _F being the Feynman variable), with the mean yield strongly exceeding the expected yield of directly produced φ mesons and varying from 〈n _φ(x _F s 0)〉 = (0.92 ± 0.34) × 10^?2 at W > 2 GeV up to (1.23 ± 0.53) × 10^?2 at W > 2.6 GeV and (1.44 ± 0.69) × 10^?2 at W > 2.9 GeV, W being the invariant mass of the hadronic system. For the first time, the inclusive yield of leading D _s ⁺ mesons carrying more than z = 0.85 of the current c-quark energy is estimated: 〈n _{D s} ⁺ (z > 0.85, W > 2.9 GeV)〉 = (6.64 ± 1.91) × 10^?2. It is shown that the shape of measured φ meson differential spectrum on xF is reproduced by that expected from the D _s ⁺ → φX decays. An indication was obtained that this expected spectrum underestimates the measured φ yield.     

Mean lifetimes of levels in 55Co

The mean lifetimes of levels in ⁵⁵Co below 5.2 MeV have been investigated with the Doppler-shift attenuation method and the ⁵⁴Fe(³He, d)⁵⁵Co reaction at 12 MeV. Scattered particles were detected in two E-ΔE telescopes at ±55° with respect to the beam axis, in coincidence with γ-rays observed at 90° and 130° in a 50 cm³ Ge(Li) detector. Mean lifetimes are reported for the following levels (energy in keV, lifetime in fs): 2166 (139±18), 2566 (680±200), 2923 (>245), 2939 (190±65), 3303 (99±22), 3323 (54±15), 3642 (680_?300⁺⁴⁰⁰), 3943 (>170), 4164 (54±15), 4180 (<16), 4722 (<33), 4749 (<70) and 5174 (<40). The experimental results are compared with a detailed shell-model calculation.     

Tiny golden angle stack-of-stars (tygaSoS) free-breathing functional lung imaging

PurposeMRI of the lung parenchyma is still challenging due to cardiac and respiratory motion, and the low proton density and short T₂*. Clinical feasible MRI methods for functional lung assessment are of great interest. It was the objective of this study to evaluate the potential of combining the ultra-short echo-time stack-of-stars approach with tiny golden angle (tyGASoS) profile ordering for self-gated free-breathing lung imaging.MethodsFree-breathing tyGASoS data were acquired in 10 healthy volunteers (3 smoker (S), 7 non-smoker (NS)). Images in different respiratory phases were reconstructed applying an image-based self-gating technique. Resulting image quality and sharpness, and parenchyma visibility were qualitatively scored by three blinded independent reader, and the signal-to-noise ratio (SNR), proton fraction (f_P) and fractional ventilation (FV) quantified.ResultThe imaging protocol was well tolerated by all volunteers. Image quality was sufficient for subsequent quantitative analysis in all cases with good to excellent inter-reader reliability. Between expiration (EX) and inspiration (IN) significant differences (p < 0.001) were observed in SNR (EX: 3.73 ± 0.89, IN: 3.14 ± 0.74) and f_P (EX: 0.27 ± 0.09, IN: 0.25 ± 0.08). A significant (p < 0.05) higher f_P (EX/IN: 0.22 ± 0.07/0.21 ± 0.07 (NS), 0.33 ± 0.07/0.30 ± 0.06 (S)) was observed in the smoker group. No significant FV differences resulted between S and NS.ConclusionThe study proves the feasibility of free-breathing tyGASoS for multiphase lung imaging. Changes in f_P may indicate an initial response in the smoker group and as such proves the sensitivity of the proposed technique. A major limitation in FV quantification rises from the large inter-subject variability of breathing patterns and amplitudes, requiring further consideration.     

Photophysics and Electrochemistry of some Thione Far-Red/Near-IR Triplet Emitters

The photophysics and cyclic voltammetry of two novel phosphorescent thiones, 2,2-dimethyl-indan-1-one-3-thione (DMIKT) and 2,2-dimethyl-indan-1,3-dithione (DMIDT), and three known phosphorescent thiones, 4H-pyran-4-thione (PT), 4H-1-benzopyran-4-thione (BPT) and 2,2-dimethylindan-1-thione (DMIT), have been characterised and compared. The phosphorescence emission of DMIT, DMIKT and DMIDT extends from the red into the near-IR spectral region. The additional carbonyl or thione group of DMIKT and DMIDT causes a significant shift in the emission maxima to 680 nm compared to that of DMIT, at 637 nm, in perfluorinated hydrocarbons. In acetonitrile the emission maxima of DMIKT and DMIDT are at 696 and 706 nm, respectively, and the spectra show vibronic bands which extend out beyond 850 nm. There is a significant reduction in triplet lifetime along this series (from 44 (±2) μs (DMIT) to 10 ((±0.8) μs (DMIKT) in perfluorinated solvents, and 8.6 (±0.5) (DMIT), 1.3 (±0.5) (DMIKT) and 0.35 (±0.07) μs (DMIDT) in acetonitrile), as well as a reduction in the rate constant for ground-state quenching of the triplet, (from 9.8 ((±0.9) to 3.5 ((±0.6) and 1.3 ((±0.2) × 10⁹ mol⁻¹ dm³ s⁻¹ for the same compounds). The addition of the C=O or C=S groups also causes a decrease in phosphorescence quantum yield with the highest emission quantum yield obtained for DMIT (Φ _P = 0.149 (±0.015)). Electrochemical studies show that while PT and BPT exhibit irreversible redox behaviour, DMIT, DMIKT and DMIDT all show at least one reversible reduction wave attributed to a one-electron process centred on the C=S moiety. The suitability of these lumophores for use in OLEDs is discussed.     

Electromagnetic transition strengths in 24Na

Mean lifetimes, excitation energies and branching ratios of ²⁴Na states, populated in the ²³Na(d, p)²⁴Na reaction have been measured. Gamma-ray spectra were measured at three angles in coincidence with proton groups at θ_p = 169°. Mean lifetimes obtained from DSA are (excitation energy in keV, lifetime in fs): 563, > 1000; 1341, 95 ± 30; 1344, 38 ± 11; 1346, > 1500; 1512, 38 ± 11; 1846, 260 ± 50; 1885, 36 ± 9; 2513, 15 ± 7; 2563, < 25; 2904, 50 ± 15; 2978, < 25; 3216, 22 ± 8; 3372, 19 ± 5. For higher levels up to 4207 keV upper limits of 30 fs were set. In combination with earlier work the following unique spin(-parity) assignments could be made: J^π(1846) = 2⁺, J(2513) = 3, J^π(3745) = 3^?. A new level at E_x = 3681.7 ± 0.6 keV is reported.     

Correction of out-of-FOV motion artifacts using convolutional neural network

PurposeSubject motion during MRI scan can result in severe degradation of image quality. Existing motion correction algorithms rely on the assumption that no information is missing during motions. However, this assumption does not hold when out-of-FOV motion happens. Currently available algorithms are not able to correct for image artifacts introduced by out-of-FOV motion. The purpose of this study is to demonstrate the feasibility of incorporating convolutional neural network (CNN) derived prior image into solving the out-of-FOV motion problem.Methods and materialsA modified U-net network was proposed to correct out-of-FOV motion artifacts by incorporating motion parameters into the loss function. A motion model based data fidelity term was applied in combination with the CNN prediction to further improve the motion correction performance. We trained the CNN on 1113 MPRAGE images with simulated oscillating and sudden motion trajectories, and compared our algorithm to a gradient-based autofocusing (AF) algorithm in both 2D and 3D images. Additional experiment was performed to demonstrate the feasibility of transferring the networks to different dataset. We also evaluated the robustness of this algorithm by adding Gaussian noise to the motion parameters. The motion correction performance was evaluated using mean square error (NMSE), peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM).ResultsThe proposed algorithm outperformed AF-based algorithm for both 2D (NMSE: 0.0066 ± 0.0009 vs 0.0141 ± 0.008, P < .01; PSNR: 29.60 ± 0.74 vs 21.71 ± 0.27, P < .01; SSIM: 0.89 ± 0.014 vs 0.73 ± 0.004, P < .01) and 3D imaging (NMSE: 0.0067 ± 0.0008 vs 0.070 ± 0.021, P < .01; PSNR: 32.40 ± 1.63 vs 22.32 ± 2.378, P < .01; SSIM: 0.89 ± 0.01 vs 0.62 ± 0.03, P < .01). Robust reconstruction was achieved with 20% data missed due to the out-of-FOV motion.ConclusionIn conclusion, the proposed CNN-based motion correction algorithm can significantly reduce out-of-FOV motion artifacts and achieve better image quality compared to AF-based algorithm.     

Intravoxel incoherent motion diffusion-weighted imaging as an adjunct to dynamic contrast-enhanced MRI to improve accuracy of the differential diagnosis of benign and malignant breast lesions

PurposeTo investigate the value of use of intravoxel incoherent motion diffusion-weighted imaging (IVIM-DWI) as an adjunct to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to distinguish benign from malignant breast lesions.Materials and methodsRetrospective analysis of data pertaining to 117 patients with breast lesions who underwent DCE-MRI and IVIM-DWI examination with 3.0 T MRI was conducted. A total of 128 lesions were pathologically confirmed (47 benign and 81 malignant). Between-group differences in DCE-MRI parameters (Morphology, enhancement pattern, maximum slope of increase (MSI) and time–signal curve (TIC) type) and IVIM-DWI parameters (f value, D value and D* value) were assessed. Multivariate logistic regression was performed to identify variables that distinguished benign from malignant breast lesions. The diagnostic performance of DCE-MRI and DCE-MRI plus IVIM-DWI, to distinguish benign from malignant breast lesions, was evaluated using pathology results as the gold standard.ResultsLesion morphology, MSI, and TIC type (P < 0.05), but not the enhancement pattern (P > 0.05), were significantly different between the benign and malignant groups. The f (8.53 ± 2.14) and D* (7.64 ± 2.07) values in the malignant group were significantly higher than those in the benign group (7.68 ± 1.97 and 6.83 ± 2.13, respectively), while the D value (0.99 ± 0.22) was significantly lower than that (1.34 ± 0.17) in the benign group (P < 0.05 for all). On logistic regression analysis, the sensitivity, specificity and accuracy of DCE-MRI were 90.1%, 70.2% and 82.8% respectively; the corresponding figures for the combination of IVIM-DWI and DCE-MRI were 88.8%, 85.1%, and 87.5%respectively.ConclusionIVIM-DWI method as an adjunct to DCE-MRI can improve the specificity and accuracy in differential diagnosis of benign and malignant lesions of breast.     

Tissue-tracking in the assessment of late gadolinium enhancement in myocarditis and myocardial infarction

PurposeTo test the diagnostic performance of cardiovascular magnetic resonance (CMR) tissue-tracking (TT) to detect the presence of late gadolinium enhancement (LGE) in patients with a diagnosis of myocardial infarction (MI) or myocarditis (MYO), preserved left ventricular ejection fraction (LVEF) and no visual regional wall motion abnormalities (RWMA).MethodsWe selected consecutive CMR studies of 50 MI, 50 MYO and 96 controls. Receiving operating characteristic (ROC) curve and net reclassification index (NRI) analyses were used to assess the predictive ability and the incremental diagnostic yield of 2D and 3D TT-derived strain parameters for the detection of LGE and to measure the best cut-off values of strain parameters.ResultsOverall, cases showed significantly reduced 2D global longitudinal strain (2D-GLS) values compared with controls (−20.1 ± 3.1% vs −21.6 ± 2.7%; p = 0.0008). 2D-GLS was also significantly reduced in MYO patients compared with healthy controls (−19.7 ± 2.9% vs −21.9 ± 2.4%; p = 0.0001). 3D global radial strain (3D-GRS) was significantly reduced in MI patients compared with controls with risk factors (34.3 ± 11.8% vs 40.3 ± 12.5%, p = 0.024) Overall, 2D-GLS yielded good diagnostic accuracy for the detection of LGE in the MYO subgroup (AUROC 0.79; NRI (95% CI) = 0.6 (0.3, 1.02) p = 0.0004), with incremental predictive value beyond risk factors and LV function parameters (p for AUROC difference = 0.048). In the MI subgroup, 2D-GRS (AUROC 0.81; NRI (95% CI) = 0.56 (0.17, 0.95) p = 0.004), 3D-GRS (AUROC 0.82; NRI (95% CI) = 0.57 (0.17, 0.97) p = 0.006) and 3D global circumferential strain (3D-GCS) (AUROC 0.81; NRI (95% CI) = 0.62 (0.22, 1.01) p = 0.002) emerged as potential markers of disease. The best cut-off for 2D-GLS was −21.1%, for 2D- and 3D-GRS were 39.1% and 37.7%, respectively, and for 3D-GCS was −16.4%.ConclusionsAt CMR-tissue tracking analysis, 2D-GLS was a significant predictor of LGE in patients with myocarditis but preserved LVEF and no visual RWMA. Both 2D- and 3D-GRS and 2D-GCS yielded good diagnostic accuracy for LGE detection in patients with previous MI but preserved LVEF and no visual RWMA.     

Valence band parameters of cubic zinc selenide derived from magnetoreflectance of the Γ6 − Γ8 exciton

Magnetoreflectance measurements on the Γ₆ ? Γ₈ free exciton ground state in cubic ZnSe in magnetic fields up to 18 Tesla are reported. The diamagnetic shift rate of the ground state components: $\text{|}\text{3}\text{2}\text{>β}$, $\text{|?}\text{3}\text{2}\text{>α}$, $\text{|}\text{1}\text{2}\text{>β}$ and $\text{|?}\text{1}\text{2}\text{>α}$ yield γ₂ = 0.53 ± 0.07 and an exciton reduced mass μ₀ = 0.117 ± 0.003, corresponding to γ₁ = 2.30 ± 0.45 for m_e¹ = 0.16 m₀. γ₁, γ₂ and an effective hole g-value $\text{κ}\text{tilde}\text{= -0.21}$ yield γ₃ = 0.82 ± 0.16 in the parabolic approximation and in agreement with the observed splitting of the $\text{|?}\text{3}\text{2}\text{>α}$, $\text{|?}\text{1}\text{2}\text{>β}$ states for B ∥ [110]. Taking into account polaron effects we derive bare valence band parameters γ₁^L = 2.71 ± 0.60, γ₂^L = 0.63 ± 0.09 and γ₃^L = 0.97 ± 0.21 from the renormalized parameters γ_i. The present results are considerably smaller than earlier theoretical calculations suggest, however they are in good agreement with a recent detailed analysis of two-photon absorption data for 2P exciton states.     

Study of K^ - \to \pi ^0 e^ - \overline \nu _e \gamma decay with ISTRA+ setup

Results of study of the $K^ - \to \pi ^0 e^ - \overline \nu \gamma $ decay at the ISTRA+ setup are presented. We observed 4476 events of this decay. The branching ratio is found to be $R = \frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}$ = (1.81±0.03(stat.)±0.07(syst.)) × 10^?2 for E*_γ > 10 MeV and θ*_eγ > 10°. For comparison with the previous experiment the branching ratio with cuts E*_γ > 10 MeV, 0.6 < cos θ*_eγ < 0.9 is calculated: R = $\frac{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e \gamma )}}{{Br(K^ - \to \pi ^0 e^ - \overline \nu _e )}}$ = (0.47±0.02(stat.) ± 0.03(syst.)) × 10^?2. For the cuts E*_γ > 30 MeV and θ*_eγ > 20°, used in most theoretical papers, Br = (3.06 ± 0.09(stat.) ± 0.14(syst.)) × 10^?4. For the asymmetry we get A _ξ = ?0.015 ± 0.021. At present it is the best estimate of this asymmetry.     

Influence of the light-curing unit, storage time and shade of a dental composite resin on the fluorescence

The aim of this study was to determine the influence of three light-curing units, storage times and colors of the dental composite resin on the fluorescence. The specimens (diameter 10.0 ± 0.1 mm, thickness 1.0 ± 0.1 mm) were made using a stainless steel mold. The mold was filled with the microhybrid composite resin and a polyethylene film covered each side of the mold. After this, a glass slide was placed on the top of the mold. To standardize the top surface of the specimens a circular weight (1 kg) with an orifice to pass the light tip of the LCU was placed on the top surface and photo-activated during 40 s. Five specimens were made for each group. The groups were divided into 9 groups following the LCUs (one QTH and two LEDs), storage times (immediately after curing, 24 hours, 7 and 30 days) and colors (shades: A₂E, A₂D, and TC) of the composite resin. After photo-activation, the specimens were storage in artificial saliva during the storage times proposed to each group at 37°C and 100% humidity. The analysis of variance (ANOVA) and Tukey’s posthoc tests showed no significant difference between storage times (immediately, 24 hours and 30 days) (P > 0.05). The means of fluorescence had difference significant to color and light-curing unit used to all period of storage (P < 0.05). The colors had difference significant between them (shades: A₂D < A₂E < TC) (P < 0.05). The Ultraled (LED) and Ultralux (QTH) when used the TC shade showed higher than Radii (LED), however to A₂E shade and A₂D shade any difference were found (P > 0.05).     

Diffusivity mapping of the ovaries: Variability of apparent diffusion and kurtosis variables over the menstrual cycle and influence of oral contraceptives

PurposeWe aimed to investigate whether quantitative diffusivity variables of healthy ovaries vary during the menstrual cycle and to evaluate alterations in women using oral contraceptives (OC).MethodsThis prospective study (S-339/2016) included 30 healthy female volunteers, with (n = 15) and without (n = 15) intake of OC between 07/2017 and 09/2019. Participants underwent 3T diffusion-weighted MRI (b-values 0–2000 s/mm²) three times during a menstrual cycle (T1 = day 1–5; T2 = day 7–12; T3 = day 19–24). Both ovaries were manually three-dimensionally segmented on b = 1500 s/mm²; apparent diffusion coefficient (ADC) calculation and kurtosis fitting (D_app, K_app) were performed. Differences in ADC, D_app and K_app between time points and groups were compared using repeated measures ANOVA and t-test after Shapiro-Wilk and Brown-Forsythe test for normality and equal variance.ResultsIn women with a natural menstrual cycle, ADC and kurtosis variables showed significant changes in ovaries with the dominant follicle between T1 vs T2 and T1 vs T3, whilst no differences were observed between T2 vs T3: ADC ± SD for T1 1.524 ± 0.160, T2 1.737 ± 0.160, and T3 1.747 ± 0.241 μm²/ms (p = 0.01 T2 vs T1; p = 1.0 T2 vs T3, p = 0.003 T3 vs T1); D_app ± SD for T1 2.018 ± 0.140, T2 2.272 ± 0.189, and T3 2.230 ± 0.256 μm²/ms (p = 0.003 T2 vs T1, p = 1.0 T2 vs T3, p = 0.02 T3 vs T1); K_app ± SD for T1 0.614 ± 0.0339, T2 0.546 ± 0.0637, and T3 0.529 ± 0.0567 (p < 0.001 T2 vs T1, p = 0.86 T2 vs T3, p < 0.001 T3 vs T1). No significant differences were found in the contralateral ovaries or in females taking OC.ConclusionPhysiological cycle-dependent changes in quantitative diffusivity variables of ovaries should be considered especially when interpreting radiomics analyses in reproductive women.     

Clinical evaluation of subtracted pointwise encoding time reduction with radial acquisition-based magnetic resonance angiography compared to 3D time-of-flight magnetic resonance angiography for improved flow dephasing at 3 Tesla

ObjectiveFlow dephasing artifacts within intracranial internal carotid artery (ICA) have been problematic for 3D time-of-flight magnetic resonance angiography (3D-TOF-MRA). This study aimed to evaluate pointwise encoding time reduction with radial acquisition subtraction-based MR angiography (PETRA-MRA) for decreasing flow dephasing artifacts compared to 3D-TOF-MRA in intracranial segments of ICA at 3 T.MethodsSixty healthy participants and seven patients with intracranial ICA aneurysms were enrolled to undergo 3D-TOF-MRA and PETRA-MRA. Two radiologists each evaluated the image quality of healthy participants using a 4-point scale (1: the best and 4: the worst). Quantitative analysis of the extent of homogeneity in signal intensity within the ICA and intracranial aneurysms was conducted using a parameter d: the higher the d value, the greater the signal homogeneity. Wilcoxon signed rank test, Chi-square test and the weighted kappa (κ) statistic were used for statistical analyses.ResultsThe image quality of PETRA-MRA with an overall score of 1.35 ± 0.53 was significantly better than that obtained with 3D-TOF-MRA, with an overall score of 3.50 ± 0.62 (Z = -9.56, p < 0.001). The parameter d of PETRA-MRA was higher than that of 3D-TOF-MRA for both 60 healthy participants (0.97 ± 0.05, 0.87 ± 0.11; z = -13.21, p < 0.001) and 7 patients with intracranial aneurysms (0.81 ± 0.18, 0.74 ± 0.16; z = -2.37, p = 0.018).ConclusionCompared with conventional 3D-TOF-MRA, PETRA-MRA remarkably improved the image quality with reduced flow dephasing artifacts in segments of intracranial ICA.