Intensity Of Spectra Research Articles

Correlations between spectrum-based and other ground-motion intensity measures considering various damping ratios

Spectral acceleration at a given period, SA( T), is usually combined with other intensity measures (IMs) for vector-valued ground-motion selection and seismic hazard assessment. The correlations between SA( T) and other IMs have been extensively studied, based on the SA-related IM pairs with a damping ratio ( ξ) of 5%. Yet, ξ varies notably with various types of structures. This article thus investigates the correlations of SA( T, ξ) with 10 commonly used non-SA IMs (e.g. Arias intensity), and the correlations of damping-specific acceleration spectrum, spectrum, and displacement spectrum intensities, namely ASI( ξ), SI( ξ), and DSI( ξ), with the other IMs. Comprehensive correlation analyses are conducted to derive the correlations for the IM pairs considered based on the NGA-West2 database and compatible ground-motion models. The results indicate that increasing ξ generally yields stronger correlations, and the difference between the ξ-specific and 5%-damped correlation coefficients could be larger than 0.2. The neural network and polynomial regressions are subsequently used to develop parametric models for estimating the correlations of SA( T, ξ)-containing pairs and the other IM pairs, respectively. All the models developed exhibit good performance in terms of predictive accuracy. The application of the proposed models is demonstrated within the generalized conditional IM approach. The models proposed could be useful for ground-motion selection and seismic demand or risk assessment for structures with various ξ values.

Evaluation of Breast Cancer Gene Type 1 (BRCA1) Protein Levels in Cancer Tissue Using Surface-Enhanced Raman Spectroscopy.

Raman spectroscopy is a chemical process that utilizes the interaction between light and matter to get significant insights into the structure or characteristics of matter. Raman spectroscopy techniques, such as quantitative evaluation, early diagnostic capabilities, and elucidation of the spectral properties of tissues, are excellent candidates for use in research. In cancer, changes in genes and proteins expressed by related genes are associated with a poor prognosis and aggressive tumor characteristics. Due to modifications and regulatory steps in protein translation, the results of the messenger RNA (mRNA) expression of genes may not correctly reflect the results of protein expression. For this reason, the mRNA and protein expressions of genes are studied in parallel in molecular studies on cancer. In our study, the breast cancer gene type 1 (BRCA1) gene, which is frequently studied in breast cancer and is relatively more difficult to measure by traditional methods due to its high molecular weight, was selected, and protein quantification was performed in tissue samples by Raman spectroscopy. With Raman spectroscopy, it is possible to obtain rapid and precise quantitative results even with a small amount of sample, so it is quite advantageous compared to traditional methods. In our study, we performed surface-enhanced Raman spectroscopy (SERS) to analyze the quantitative protein amount. SERS is a highly sensitive method for detecting compounds at low concentrations. For this purpose, magnetic nanoparticles modified with protein antibodies were used, and the target protein was withdrawn from the complex environment and transferred to an appropriate buffer environment. The calibration curve for BRCA1, which plots Raman intensity against concentration, was derived by calculating the average response reading from duplicate assays conducted under identical conditions. The BRCA1 protein levels of cells were determined from the regression curve of the BRCA1 protein. The relation between the concentration of BRCA1 protein and SERS spectrum intensity was determined to be logarithmic in the range of 300 µg·mL-1 to 292 ng·mL-1 (R2 = 0.9928, limit of detection = 10.41 µg·mL-1, and limit of quantitation = 31.24 µg·mL-1).

Correlation between spin-dependent recombination centers and long-lived polarons generated in organic photovoltaic devices revealed by successive ESR and EDMR measurements

Using a successive detection technique with electron spin resonance (ESR) and electrically detected magnetic resonance (EDMR), this study clarifies the quantitative correlation between photoinduced spin amounts and spin-dependent recombination (SDR) currents in organic photovoltaic devices (OPVs). Using this unique method of sequentially switching between ESR and EDMR measurements under light irradiation, we find that the intensities of light-induced ESR and EDMR spectra increase along with the light irradiation power. Although positive correlation exists between the number of photo-generated radicals and the SDR currents, the relation is not proportional, which demonstrates that most of the photo-generated radicals are residual accumulated charges. Additionally, phases of the EDMR spectra under light irradiation were found to be changed because of a delay of modulated EDMR signals. The phase variation is probably caused by recombination centers: positive polarons that have arrived at the interface between an aluminum electrode and an active layer by charge drifting after charge separation. Because positive polarons are expected to transport positive charges to the opposite-side electrode of the aluminum as a negative charge collector, this leakage current can be a factor of disturbing an optimal charge collection. This combined technique of ESR and EDMR is useful to explore the different roles of polarons in the photovoltaic conversion processes, thereby providing important information for improving the fill factors and open-circuit voltages of the OPVs, which generate long-lived polarons.

Effect of Composition and Phase Separation on Structure and Luminescence Properties of Tb3+ Doped Borosilicate Glasses

Two borosilicate glass series with different Na2O/B2O3 ratio and different phase separation probability have been doped with largely different concentrations of Tb3+. The addition of rare earth elements increases the phase separation tendency of borosilicate glasses, allowing to study the process in detail. Phase separation structures were also modified by annealing the glass samples at different temperatures and times. The occurring effects were studied by high resolution transmission electron microscopy (TEM) as well as with static and dynamic luminescence measurements. Strong effects of glass composition, doping concentration, and annealing on the intensity and shape of the luminescence spectra and the time-resolved luminescence are found and explained.

Interactions of hydrophobically associating polymers with anionic surfactant sodium dodecylbenzene sulfonate: Experiments and simulations

Herein, the interaction of the hydrophobically associating polymer HP-1 with the anionic surfactant sodium dodecylbenzene sulfonate (SDS) was investigated using solution viscosity by Brookfield viscometer, rheology including steady shear rheology and dynamic frequency sweep rheology, ambient scanning electron microscopy, and fluorescence measurements and then simulated and analyzed using dissipative particle dynamics simulations (DPD). The results showed that as SDS concentration increased, the solution viscosity of the HP-1/SDS system first declined, then increased, reached a peak, and then decreased again before gradually leveling off. The rheology and microscopic morphology of the system exhibited similar patterns of change. The system’s solution shear rheology and viscoelasticity decreased with increasing SDS concentration, then increased and ultimately decreased, and the system’s reticulation structure changed from loose to tight and then again to loose, according to the law of composite viscosity. Moreover, the ratio of the emission peak intensities of the monomer fluorescence spectra of pyrene molecules in solution at 372 and 383 nm (I3/I1) first decreased, then increased, and finally stabilized. This implies that the above phenomenon is associated with the change in the number of HP-1’s hydrophobic interaction. Thus, SDS affects both the binding efficiency and number of binding groups of HP-1, resulting in a change in the properties of the solution. Finally, DPD simulations were performed to study the interaction between SDS and HP-1, confirming the experimental data-derived supposition. Upon the addition of SDS, it began to interact with HP-1 hydrophobic groups until all of the hydrophobic groups were coated with SDS, resulting in coiling of the HP-1 polymer chains. Meanwhile, SDS molecules adsorbed onto the polymer chain and aggregated with each other to form micelles, altering the properties of the solution.

Spin-Selective Charge Transfer-SERS Driven Label-Free Enantioselective Discrimination of Chiral Molecules on Ag Nanoparticle-Decorated Ni Nanorod Arrays.

Enantioselective discrimination is critical in several fields, particularly in pharmaceutics and clinical drug research. Chiral molecules possess unique charge transfer properties, showing an enantioselective preference for electron spin orientation when interacting with the magnetic surface. Here, we developed spin-selective charge transfer (SSCT)-based label-free surface-enhanced Raman scattering (SERS) achiral magnetic substrates for the enantioselective discrimination of chiral molecules without creating asymmetric chiral adsorption sites. The e-beam-based glancing angle deposition (GLAD) technique was utilized to construct achiral magnetic surface-enhanced Raman scattering (SERS) substrates by decorating Ag nanoparticles over Ni nanorods. SERS spectroscopy was carried out on significant enantiomers, including cystine, alanine, and DOPA (l-3-(3,4-dihydroxyphenyl) alanine). An external electromagnet was used to manipulate the magnetic substrate's spin polarization by altering the magnetic field's direction. Subsequently, SERS spectra were acquired. Based on the magnetic field's direction, there is a complementary variation in the intensities of SERS spectra of the enantiomers. The SSCT process between molecule-metal complexes synergized with the magnetic field direction to control the electron spin, leading to SERS-based enantioselective discrimination. This label-free, easy, yet practical approach offers a characteristic paradigm shift from the recent complex approaches for chiral detection and separation.

Photophysics of Hydrophobic Corroles in the Aqueous Micellar Media and in the Presence of Graphene Oxide and Bioanalytes.

Here two A2B type corrole has been synthesized and solubilized in water via pluronic micelle system by avoiding the utmost mandatory multistep non-environment friendly strategies for bringing hydrophobic non-ionic corroles in aqueous medium. Both the corroles were extremely insoluble in water as no absorption spectra of corrole was available in water. However, corrole 2 in the aqueous solution of F127 exhibit characteristic Soret and Q bands due to efficient solubilization of corrole in F127, the micelles formed by block copolymer act as a "cargo hold" for the corrole molecules. Intense emission spectra were observed for both the corroles in the aqueous solution of F127. We further observed that fluorescence properties of corrole-F127 micelle systems are quenched in presence of graphene oxide (GO) without change in the wavelength or shape of the emission band. The possibility of a dynamic quenching is probed more quantitatively by recording the emission decay profiles of corrole-F127-GO system. This quenching of fluorescence intensity of graphene oxide dispersed corrole-F127 micellar system was partially re-established in the presence of bioanalytes such as dopamine, ascorbic acid. Therefore, the present work has a future potential application for analyzing the interaction with different bioanalytes in biological systems using corrole-GO composite.

Design and synthesis of star-shaped non-fullerene acceptors based on triarylamine core for organic photovoltaic applications

Abstract Non-fullerene acceptors were synthesized with triphenylamine (TPA) and 9-phenylcarbazole core functionalized with oxindole moiety as well as electron accepting groups such as cyano and trifluoromethyl groups leading to precisely tuned molecular electronic structures and intermolecular arrangements. This approach maintained high thermal stability and excellent electron mobility while optimizing optoelectronic properties, providing a novel strategy for developing organic photovoltaic materials. LUMO levels of three receptors are comparable to PC61BM. The decomposition temperatures of all three acceptors exceeded 380°C under N2 flow, indicating the exceptional thermal stability. Notably, the acceptor consisting of TPA core with three oxindole moieties exhibited the red-shifted and intense UV-vis absorption spectrum and the narrowest optical bandgap (Egopt = 2.14 eV). Furthermore, the higher electron mobility was observed compared to analogues with 9-phenylcarbozle unit. The power conversion efficiency (PCE) of the device based on TPA core acceptor and regio-regular poly(3-hexylthiophene) surpassed those of the devices based on the other two acceptors.

Enzyme-assisted upconversion fluorescence-encoded biosensing system for simultaneous detection of multiple sites EGFR mutation.

Epidermal growth factor receptor (EGFR) mutations play a key role in the development of a variety of cancers. Rapid detection and screening of EGFR mutation types in patients are of great significance for early treatment of patients. In this study, a highly sensitive fluorescent biosensing system based on lanthanide ion-doped multi-type upconversion nanoparticles (UCNPs) combined with polymerization reaction signal amplification was designed and constructed for the simultaneous detection of L858R and 19Del mutations. Two upconversion nanoparticles (NaYF4:Yb, Er and NaYF4:Yb, Tm) with unique upconversion fluorescence profiles were first prepared using Er and Tm as activators, respectively. Subsequently, the UCNPs were enriched by cDNA complementary hybridization and atom transfer radical polymerization (ATRP) reactions to enhance the signal. Next, the tDNA/cDNA hybrids were cleaved using specific restriction endonucleases to detach UCNPs aggregates from the surface of the magnetic beads. Finally, the fluorescence signal in the supernatant was detected after magnetic separation. The simultaneous quantitative detection of the two EGFR mutations was achieved by analyzing the changes in signal intensity of the characteristic upconversion fluorescence spectra of the two encoded UCNPs at their respective emission peaks. The detection range of the method was from 10 fM to 10nM, and the detection limits were 2.44 fM for L858R and 2.13 fM for 19Del. The sensing system was able to effectively differentiate between wild-type and other mutation types, and its detection results were consistent with qPCR. The excellent performance of the sensor suggests its promising application in the diagnosis and precision treatment of NSCLC.

Light Therapy for Older People with Depressive Symptoms: Systematic Review and Meta-Analysis.

Background/Objectives: Light therapy has emerged as a promising non-pharmacological treatment for depressive symptoms. This meta-analysis aims to evaluate the effectiveness of light therapy specifically for depressive symptoms in elderly populations, with a focus on how different light intensities and spectra influence treatment outcomes. Methods: A systematic search targeting studies on light therapy for depressive symptoms in older adults was performed across multiple databases, including PubMed, Google Scholar, PsycINFO, and EMBASE, covering studies from database inception until July 2024. A total of 565 records were identified, with 461 studies remaining after removing duplicates. Following the screening of titles and abstracts, 54 studies underwent full-text review, resulting in the inclusion of 22 studies with a total of 1290 participants (687 in the intervention group and 603 in the control group). Results: The overall effect size for light therapy on depressive symptoms was moderate (Hedges' g = 0.525, p < 0.001). Higher light intensities (10,000 lux and above) demonstrated significantly greater effectiveness compared to lower intensities. White light had the most substantial effect, while bluish light showed moderate efficacy. Significant heterogeneity was observed across studies (I2 = 80.459%), indicating variability in treatment outcomes based on study design, intensity, and light spectrum. Conclusions: This meta-analysis confirms that light therapy is an effective treatment for reducing depressive symptoms in older adults, particularly at higher intensities and with specific light spectra such as white light. Given the heterogeneity in results, future research should focus on optimizing treatment parameters to enhance clinical outcomes within this population.

Probing the Electronic Manifold of MgCl with Millimeter-Wave Spectroscopy and Theory: (3)2Σ+ and (4)2Σ+ States.

The millimeter/submillimeter spectrum of magnesium chloride (MgCl) has been observed in two new electronic excited states, (3)2Σ+ and (4)2Σ+, using direct absorption methods. The molecule was synthesized in a mixture of Cl2, argon, and magnesium vapor. For the (3)2Σ+ state, multiple rotational transitions were measured in the v = 0 level for all six isotopologues (24Mg35Cl, 24Mg37Cl, 25Mg35Cl, 25Mg37Cl, 26Mg35Cl, and 26Mg37Cl), as well as up to v = 13 for 24Mg35Cl. For the (4)2Σ+ state, less intense spectra were recorded for 24Mg35Cl (v = 0-2). Equilibrium rotational parameters were determined for both states for 24Mg35Cl, as well as rotational constants and 25Mg hyperfine parameters for the other isotopologues. A perturbation was observed between rotational levels of the two states due to an avoided crossing. Computations were also carried out at the CASPT2 and MRCISD+Q levels, and the resulting bond lengths for (3)2Σ+ and (4)2Σ+ states agree well with the experimental values of re = 2.536 and 2.361 Å. The computations show that the (3)2Σ+ state has a double-well potential; however, the state behaves as a single well with unperturbed vibrational levels up to v = 13 due to nonadiabatic interactions with the (4)2Σ+ state.

Impact of chlorine substitution on valence orbitals and ionization dynamics in 3-chloropyridine: Insights from high-resolution vacuum ultraviolet mass-analyzed threshold ionization study.

In this study, the effects of chlorine substitution on the valence orbitals and electronic states of 3-chloropyridine (3-CP) were investigated utilizing high-resolution vacuum ultraviolet mass-analyzed threshold ionization (VUV-MATI) spectroscopy and computational methods. High-quality vibrational spectra were obtained from the VUV-MATI spectra of 3-CP isotopomers (35Cl and 37Cl), revealing high-quality vibrational spectra for the lowest cationic states. The adiabatic ionization energies (AIEs) of these isotopomers were accurately determined, providing detailed information about the electronic structure and ionization dynamics. Intense spectra peaks were linked with the D1 excited state of the 3-CP cation, with vibronic transitions in this state closely matching those predicted by Franck-Condon simulations. This provided insights into the cationic structure and the roles of the highest occupied molecular orbital (HOMO) and the HOMO-1. The HOMO was primarily a π orbital of the pyridine ring, while the HOMO-1 consisted of nonbonding orbitals. The AIEs suggested that meta-chlorine substitution stabilizes nonbonding orbitals less effectively than ortho substitution, indicating closely spaced electronic states in the 3-CP cation. Minor discrepancies in vibrational frequencies and intensities, particularly above 800cm-1, suggested the presence of vibronic coupling, warranting further investigation. Overall, this study provided a comprehensive understanding of the vibronic and ionization properties of 3-CP, emphasizing the influence of the position of the chlorine substitution on molecular orbitals and the value of advanced theoretical and experimental approaches for analyzing the vibrational spectra of complex molecules.

Assessing Vertical Bioturbation Intensity from Bedding Planes

Bedding planes hold significant value in ichnological analyses as they improve the recognition of ichnotaxa and yield important insights into the distribution and morphology of trace fossils. However, a significant limitation lies in the challenge of accurately estimating bioturbation intensity from bedding planes. This is in part because current approaches do not establish a connection between bioturbation intensity as seen on bedding planes (plan view) and in cross-section (elevation view). This disconnect complicates the integration of bedding plane assessments into more conventional datasets collected from elevation view. Seventy-seven million Monte Carlo simulations were performed on 11 non-palimpsest Skolithos assemblages, each with varying constraints on burrow length and diameter. These simulations were used to investigate the range and frequency of cross-sectional bioturbation intensities across a spectrum of bedding plane intensities (2-50%). The results show that elevation view bioturbation intensity can be reliably approximated by multiplying plan view bioturbation intensity by the average burrow length relative to the bed thickness, independent of burrow diameter. These findings improve the ichnological analysis of bedding planes for vertical trace fossil assemblages and offer a framework for future research into more complex assemblages.

Tunable Broadband NIR-II Emission via Cr4+-Er3+ Energy Transfer in CaMgGeO4:Cr4+,Er3+ Phosphors for Nondestructive Analysis.

Although there have been numerous reports on broadband near-infrared (NIR) emitting phosphors, their emissions are mainly concentrated in the range of 700-1000 nm (NIR-I). Herein, we successfully synthesized a broadband near-infrared phosphor CaMgGeO4:Cr4+(CMG:Cr4+) with an emission in the range of 1000-1600 nm (NIR-II). The introduction of Er3+ ions into CMG:Cr4+ resulted in a wider near-infrared emission phosphor CaMgGeO4:Cr4+,Er3+ (fwhm = 361 nm), compensating for the luminescence of 1500-1600 nm. More importantly, an energy transfer from Cr4+ to Er3+ ions has been discovered. Furthermore, a NIR pc-LED was fabricated by combining the CMG:Cr4+,Er3+ phosphor with a 590 nm chip. The changes in intensity and profile of the transmission spectra of light passing through different liquids reveal its potential application in organic compound recognition. This work opens a direction for the development of NIR-II phosphors.

Chlorophyll films for radiation dosimetry: a feasibility study

Abstract Novel Chlorophyll-PVA composite films have been prepared and tested for the dosimetry of therapeutic radiation. The radiation response has been quantified using UV–vis spectroscopy. FTIR and XRD spectroscopies have been used to characterize the physical properties and irradiation response of the films. The films have shown response towards the therapeutic x-rays beams of 6 MV nominal energy in the tested dose range of 0.25 Gy to 32 Gy in discrete dose levels occurring in the geometric progression series of 2. The dosimeter has been found to exhibit sensitivity at a low dose of 0.25 Gy. The dose response curve of the dosimeter exhibits an exponential relationship of the absorbance and absorbed dose. A region of saturated absorbance has been observed beyond 4 Gy. The peak intensities of the FTIR spectra have been found to decrease with increasing doses as compared to the unirradiated samples, because of the changes in the bond polarities and molecular geometries. The XRD spectra indicates a change in the molecular orientation resulting in a decrease in peak intensity with increasing dose. This study indicates the feasibility of chl-PVA films in the dosimetry of therapeutic radiation. This film dosimeter can be processed locally with minimum resources and standardized against a known standard before clinical use. The chlorophyll molecules need careful handling owing to their sensitivity to light and temperature.

Effects of Tube Diameter and Gas Flow Rate on the Discharge Dynamics Characteristics and Reactive Species of Nanosecond Pulsed Discharge Plasma in Contact With Water

ABSTRACTThe use of millimeter quartz tubes to generate non‐thermal plasma in contact with liquid is widely applied in medicine, such as the effective disinfection of catheter tubes and tooth cavities. Here, the effects of tube diameter and gas flow rate on discharge dynamics and reactive species characteristics of nanosecond pulse needle‐water discharge are studied using an ICCD camera and optical emission spectra. The discharge diffusion is increased significantly by an appropriate combination of tube diameter and gas flow rate. Besides, the discharge intensity, emission spectra intensities of reactive species, gas temperature, and electron density increase with the increase of quartz tube diameter and gas flow rate, which contributes to enhance the production of OH and H2O2 species in aqueous samples.

Enhancing the Segmentation Accuracy of the Otsu Method for Calculating Blood Vessel Rupture Volumes in CT-Scan Images

The precise quantification of cerebral hemorrhage volume assumes paramount significance, given its consequential impact on subsequent medical interventions. While antecedent scholarly endeavors have undertaken cerebral hemorrhage volume computations, the attendant accuracy remains amenable to refinement. The main contribution to this research is the development of a rectangle algorithm using the Otsu method, which can be used to calculate the total volume of brain hemorrhage in CT-Scan images of the human brain. The present investigation seeks to augment the segmentation paradigm inherent to the Otsu method, thereby advancing the precision of cerebral hemorrhage volume assessments. The Otsu method is conceived with the purpose of automating the segmentation of the hemorrhagic domain through the determination of threshold values. The refinement of the Otsu method’s accuracy is effectuated by the formulation of an algorithm aimed at maximizing the mean discrepancy between object and background intensities within the object image, predicated upon the ascertained threshold values. These determined thresholds subsequently govern the transformation of grayscale images into binary format, achieved through the quotient of the threshold value and the mean variance, thereby amplifying segmentation precision. The incorporation of variance and mean values in the binarization of grayscale images affords adaptability in threshold modulation commensurate with the intensity spectrum of the image. The research corpus leverages CT-Scan images sourced from RSUP M. Djamil Padang, West Sumatra, encompassing a compendium of 100 image slices culled from a quintet of patients. Empirical findings attest to the fortification of the Otsu method in the segmentation milieu, substantiating the augmentation of threshold value accuracy. This enhancement is conspicuously manifest in the outcomes of segmentation tests, underscoring the superior efficacy of the Otsu method in discerning between objects and backgrounds. The corollary effect is a discernibly more accurate computation of volumes employing the Otsu-T methodology. The import of this research rests in its successful establishment of automated threshold values and the concomitant elevation of segmentation precision.

Theoretical and Experimental Analyses of the Interfacial Mechanism of Dendrimer-Doxorubicin Complexes Formation.

The work presents correlations between the physicochemical properties of the carrier and the active substance and optimization of the conditions for creating an active system based on PAMAM dendrimers and doxorubicin. The study monitored the influence of the ionized form of the doxorubicin molecule on the efficiency of complex formation. The deprotonated form of doxorubicin occurs under basic conditions in the pH range of 9.0-10.0. In the presence of doxorubicin, changes in the zeta potential of the complex concerning the initial system are observed. These changes result from electrostatic interactions between the drug molecules and external functional groups. Based on changes in the absorbance intensity of UV-vis spectra, the binding of the drug in the polymer structure is observed depending on the pH of the environment and the molar ratio. Optimal conditions for forming complexes occur under alkaline conditions. UV-vis, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy confirmed the stability of the formed dendrimer-DOX complex. Molecular dynamics simulations were conducted to gain a deeper insight into the molecular mechanism of DOX adsorption on and within the G4.0 PAMAM dendrimers. It was observed that the protonation state of both the dendrimer and DOX significantly influences the adsorption stability. The system exhibited high stability at high pH values (∼9-10), with DOX molecules strongly adsorbed on the dendrimer surface and partially within its bulk. However, under lower pH conditions, a reduction in adsorption strength was observed, leading to the detachment of DOX clusters from the dendrimer structure.

Technical note: Altitude scaling of 36Cl production from Fe

Abstract. Cosmogenic nuclide production rates depend on the excitation functions of the underlying nuclear reactions and the intensity and energy spectrum of the cosmic-ray flux. The cosmic-ray energy spectrum shifts towards lower average energies with decreasing altitude (increasing atmospheric depth), so production rate scaling will differ for production reactions that have different energy sensitivities. Here, we assess the possibility of the unique scaling of 36Cl production from Fe by modeling changes in the 36ClFe/36ClK and 36ClFe/10Beqtz production ratios with altitude. We evaluate model predictions against measured 36Cl concentrations in magnetite and K-feldspar and 10Be concentrations in quartz from granitic rocks exposed across an elevation transect (ca. 1700–4300 ma.s.l.) in western North America. The data are broadly consistent with model predictions. The null hypothesis that 36ClFe/10Beqtz and 36ClFe/36ClK production ratios are invariant with altitude can be rejected at the 90 % confidence level. Thus, reaction-specific scaling factors will likely yield more accurate results than non-reaction-specific scaling factors when scaling 36Cl production in Fe-rich rocks and minerals.

The effects of ultrasound-assisted glycation on the allergenicity and functional properties of peanut proteins

This study investigated the effects of ultrasound-assisted glycation on the allergenicity and functional properties of peanut proteins. Results showed that ultrasound-assisted glycation increased the degree of glycation reaction of peanut proteins significantly (P < 0.05). ELISA results indicated that the binding of peanut allergens with serum immunoglobulin G (IgG) and immunoglobulin E (IgE) was significantly decreased (P < 0.05). Furthermore, secondary structure analysis revealed a significant increase in β-sheet content, alongside decreases in α-helix, β-turn, and random coil contents (P < 0.05). In addition, intrinsic fluorescence intensity, surface hydrophobicity, and ultraviolet (UV) spectra intensity were diminished (P < 0.05), indicating notable changes in both secondary and tertiary structures of peanut proteins. Moreover, emulsification property, antioxidant activity and in vitro digestibility of peanut proteins showed the most obvious improvements following ultrasound-assisted glycation, and the solubility was increased while turbidity was decreased significantly (P < 0.05). In conclusion, this study demonstrated that ultrasound-assisted glycation not only effectively reduced the allergenicity of peanut allergens, but also improved the overall functional properties of peanut proteins, and the changes in sensitization and functional properties might be closely related to structural changes. This study will provide a theoretical basis for the development of peanut products.