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Resting-state neural oscillations are used as biomarkers for functional diseases such as dementia, epilepsy, and stroke. However, accurate interpretation of clinical outcomes requires the identification and minimisation of potential confounding factors. While several studies have indicated that the menstrual cycle also alters brain activity, most of these studies were based on visual inspection rather than objective quantitative measures. In the present study, we aimed to clarify the effect of the menstrual cycle on spontaneous neural oscillations based on quantitative magnetoencephalography (MEG) parameters. Resting-state MEG activity was recorded from 25 healthy women with normal menstrual cycles. For each woman, resting-state brain activity was acquired twice using MEG: once during their menstrual period (MP) and once outside of this period (OP). Our results indicated that the median frequency and peak alpha frequency of the power spectrum were low, whereas Shannon spectral entropy was high, during the MP. Theta intensity within the right temporal cortex and right limbic system was significantly lower during the MP than during the OP. High gamma intensity in the left parietal cortex was also significantly lower during the MP than during the OP. Similar differences were also observed in the parietal and occipital regions between the proliferative (the late part of the follicular phase) and secretory phases (luteal phase). Our findings suggest that the menstrual cycle should be considered to ensure accurate interpretation of functional neuroimaging in clinical practice.

New values of neutron fluxes and spectral parameters and were determined experimentally in all irradiation devices of the TRIGA Mark I IPR-R1 nuclear research reactor at Nuclear Technology Development Centre (CDTN), Belo Horizonte, Brazil. Sets of monitors Au, Fe, Zn and Zr were irradiated bare and Cd-covered, according to \"Cd-ratio for multi-monitor\" method. Values were validated by analysing the certified reference material BCR-320R irradiated in chosen channels. The calculations were made based on irradiation channel values and the average values of the Carousel. The results of score point out that the -method is producing reliable results. From now on, the values of mass fractions in several matrices, the production and studies with radioisotopes will be more accurate and the activities calculated more precisely.

Objective To assess the diagnostic value of spectral parameters in differentiating adrenal adenomas from metastases based on dual-layer detector spectral CT (DLSCT). Materials and methods Patients with adenomas or metastases who underwent enhanced DLSCT of the adrenals were enrolled. The CT values of virtual non-contrast images (CT VNC ), iodine density (ID) values, and Z-effective (Z-eff) values, the normalized iodine density (NID) values, slopes of spectral HU curves (s-SHC), and iodine-to-CT VNC ratios of the tumors were measured in each phase. Receiver operating characteristic (ROC) curves were used to compare the diagnostic values. Results Ninety-nine patients with 106 adrenal lesions (63 adenomas, 43 metastases) were included. In the venous phase, all spectral parameters were significantly different between adenomas and metastases (all p  < 0.05). The combined spectral parameters showed a better diagnostic performance in the venous phase than in other phase ( p  < 0.05). The iodine-to-CT VNC value had a larger area under the ROC curve (AUC) than the other spectral parameters in the differential diagnosis of adenomas and metastases, with a diagnostic sensitivity and specificity of 74.4% and 91.9%, respectively. In the differential diagnosis of lipid-rich adenomas, lipid-poor adenomas and metastases, the CT VNC value and s-SHC value also had a larger AUC than the other spectral parameters, with a diagnostic sensitivity of 97.7%, 79.1% and specificity of 91.2%, 93.1%, respectively. Conclusion On DLSCT, the combined spectral parameters in the venous phase could help better distinguish adrenal adenomas from metastases. The iodine-to-CT VNC , CT VNC and s-SHC values had the highest AUC values in differentiating adenomas, lipid-rich adenomas and lipid-poor adenomas from metastases, respectively.

In order to rapidly and accurately monitor cadmium contamination in lettuce and understand the growth conditions of lettuce under cadmium pollution, lettuce is used as the test material. Under different concentrations of cadmium stress and at different growth stages, relative chlorophyll content of lettuce leaves, the cadmium content in the leaves, and the visible-near infrared reflectance spectra are detected and analyzed. An inversion model of the cadmium content and relative chlorophyll content in the lettuce leaves is established. The results indicate that cadmium concentrations of 1 mg/kg and 5 mg/kg promote relative chlorophyll content, while concentrations of 10 mg/kg and 20 mg/kg inhibit relative chlorophyll content. The cadmium content in the leaves increases with increasing cadmium concentrations. Cadmium stress caused a “blue shift” in the red edge position only during the mature period, while the red valley position underwent a “blue shift” during the seedling and growth periods and a “red shift” during the mature period. The green peak position exhibited a “blue shift”. After model validation, it was found that the model constructed using the ratio of red edge area to yellow edge area and the normalized values of red edge area and yellow edge area effectively estimated the cadmium content in lettuce leaves. The model established using the normalized vegetation index of the red edge and the ratio of the peak green value to red shoulder amplitude can effectively estimate the relative chlorophyll content in lettuce leaves. This study demonstrates that the visible-near infrared spectroscopy technique holds great potential for monitoring cadmium contamination and estimating chlorophyll content in lettuce.

Fluorescence of iron ions induced by an X-ray laser allows the relative oscillator strength for Fe xvii emission to be determined; it is found to differ by 3.6 σ from the best quantum mechanical calculations, suggesting that the poor agreement between prediction and observations of the brightest Fe  xvii line is rooted in the quality of the underlying atomic wavefunctions used in the models. New look at highly charged astrophysical iron The interpretation of some of the spectral data from the Chandra and XMM-Newton orbiting X-ray missions has been complicated by discrepancies between theory and observation involving the emission lines from the highly charged Fe 16+ ion, also known as Fe XVII. Specifically, the intensity of the strongest Fe XVII line, one of the brightest X-ray emissions from galaxies and stars, is generally weaker than predicted. Sven Bernitt et al . report the results of laboratory experiments in which a target of iron ions was fluoresced with femtosecond X-ray pulses from a free-electron laser. They find a relative oscillator strength that differs by 3.6 σ from the best quantum mechanical calculations, suggesting that the poor agreement is rooted in the calculations of the underlying atomic dynamics and that the current astrophysical models are not at fault. Highly charged iron (Fe 16+ , here referred to as Fe  xvii ) produces some of the brightest X-ray emission lines from hot astrophysical objects 1 , including galaxy clusters and stellar coronae, and it dominates the emission of the Sun at wavelengths near 15 ångströms. The Fe  xvii spectrum is, however, poorly fitted by even the best astrophysical models. A particular problem has been that the intensity of the strongest Fe  xvii line is generally weaker than predicted 2 , 3 . This has affected the interpretation of observations by the Chandra and XMM-Newton orbiting X-ray missions 1 , fuelling a continuing controversy over whether this discrepancy is caused by incomplete modelling of the plasma environment in these objects or by shortcomings in the treatment of the underlying atomic physics. Here we report the results of an experiment in which a target of iron ions was induced to fluoresce by subjecting it to femtosecond X-ray pulses from a free-electron laser 4 ; our aim was to isolate a key aspect of the quantum mechanical description of the line emission. Surprisingly, we find a relative oscillator strength that is unexpectedly low, differing by 3.6 σ from the best quantum mechanical calculations. Our measurements suggest that the poor agreement is rooted in the quality of the underlying atomic wavefunctions rather than in insufficient modelling of collisional processes.

The questions of the one-value solvability of an inverse boundary value problem for a mixed type integro-differential equation with Caputo operators of different fractional orders and spectral parameters are considered. The mixed type integro-differential equation with respect to the main unknown function is an inhomogeneous partial integro-differential equation of fractional order in both positive and negative parts of the multidimensional rectangular domain under consideration. This mixed type of equation, with respect to redefinition functions, is a nonlinear Fredholm type integral equation. The fractional Caputo operators’ orders are smaller in the positive part of the domain than the orders of Caputo operators in the negative part of the domain under consideration. Using the method of Fourier series, two systems of countable systems of ordinary fractional integro-differential equations with degenerate kernels and different orders of integro-differentation are obtained. Furthermore, a method of degenerate kernels is used. In order to determine arbitrary integration constants, a linear system of functional algebraic equations is obtained. From the solvability condition of this system are calculated the regular and irregular values of the spectral parameters. The solution of the inverse problem under consideration is obtained in the form of Fourier series. The unique solvability of the problem for regular values of spectral parameters is proved. During the proof of the convergence of the Fourier series, certain properties of the Mittag–Leffler function of two variables, the Cauchy–Schwarz inequality and Bessel inequality, are used. We also studied the continuous dependence of the solution of the problem on small parameters for regular values of spectral parameters. The existence and uniqueness of redefined functions have been justified by solving the systems of two countable systems of nonlinear integral equations. The results are formulated as a theorem.

The questions of solvability of a nonlocal inverse boundary value problem for a mixed pseudohyperbolic-pseudoelliptic integro-differential equation with spectral parameters are considered. Using the method of the Fourier series, a system of countable systems of ordinary integro-differential equations is obtained. To determine arbitrary integration constants, a system of algebraic equations is obtained. From this system regular and irregular values of the spectral parameters were calculated. The unique solvability of the inverse boundary value problem for regular values of spectral parameters is proved. For irregular values of spectral parameters is established a criterion of existence of an infinite set of solutions of the inverse boundary value problem. The results are formulated as a theorem.

In this article, the electronic UV–visible absorption spectra of disperse orange 3 (C12H10N4O2) are examined in ethanol solvent at varying concentrations (10−3 M, 10−4 M, 10−5 M, 10−6 M, 20 µM, and 40 µM). Azo chromophores are used extensively in the liquid crystal industry, inkjet printing, light-controlled polymers, textiles, and pharmaceutical sectors. The molar extinction coefficient (εmax) and oscillator strength (f) corresponding to maximum absorbance λmax (443 nm) in ethanol at concentration 10−4 M were calculated as 1.35 × 104 M−1 cm−1 and 15.83 × 10−2 M−1 cm−2, respectively. The dipole moment of the considered peak was calculated as 4.45 D. Other spectral parameters of scientific importance, such as absorption cross-section and attenuation length, were also calculated as 0.32 × 10−16 cm2 and 0.027 cm, respectively. The transitions associated with absorption bands observed at 227 nm, 275 nm, and 443 nm were correlated to (primary π* ← π), (secondary π* ← π), and (π* ← n) by comparison of dye moieties. This confirmed that 10−4 M is the optimum concentration for spectroscopically investigating the dye (DO3). The quenching was observed by examining fluorescence spectra at various concentrations. The molecule being investigated unequivocally demonstrates fluorescence at 532 nm at 10−4 M concentration when excited with λex = 440 nm. This results in a notable Stokes shift (Δλ = 89 nm or Δν = 3776 cm−1), which is vital for fluorescence imaging.

The high-energy density behavior of carbon, particularly in the vicinity of the melt boundary, is of broad scientific interest and of particular interest to those studying planetary astrophysics and inertial confinement fusion. Previous experimental data in the several hundred gigapascal pressure range, particularly near the melt boundary, have only been able to provide data with accuracy capable of qualitative comparison with theory. Here we present shock-wave experiments on carbon (using a magnetically driven flyer-plate technique with an order of magnitude improvement in accuracy) that enable quantitative comparison with theory. This work provides evidence for the existence of a diamond-bc8-liquid triple point on the melt boundary.

In this paper, the authors consider the spectra of second-order left-definite difference operator with linear spectral parameters in two boundary conditions. First, they obtain the exact number of this kind of eigenvalue problem, and prove these eigenvalues are all real and simple. In details, they get that the number of the positive (negative) eigenvalues is related to not only the number of positive (negative) elements in the weight function, but also the parameters in the boundary conditions. Second, they obtain the interlacing properties of these eigenvalues and the sign-changing properties of the corresponding eigenfunctions according to the relations of the parameters in the boundary conditions.