Exposure to ionizing radiation has been associated with the development of neoplasms in humans and other animals. Detection of both neoplastic growth and effects of radiation with standard laboratory testing (hematology and serum chemistry analyses) is problematic. There are no specific biomarkers present in biological fluids (blood, urine) for early detection of neoplastic growth or long-term effects of radiation exposure, but these would be extremely useful for monitoring both treatment efficacy and detecting undesirable side effects in patients undergoing radiotherapy. We conducted a retrospective study of 76 urine samples from rhesus macaques using a novel Raman spectroscopy-based analytical technology (Raman Molecular Urinalysis) to establish a urine fingerprint for past radiation treatment. Forty-nine animals were irradiated (of which 12 developed sarcomas following experimental exposure to total body ionizing radiation) and 27 animals were not irradiated (2 of which developed non-radiation-associated sarcomas). We applied an unsupervised principal component analysis and supervised discriminant analysis of principal components and averaged the spectra. The results showed the groups had a highly similar average spectra, but more variability and outliers existed in the irradiated group of animals. The unique characteristics of these outliers were unclear, and further investigation is needed. Animals with sarcomas had a distinct spectral profile with high specificity and high negative predictive value. A definitive radiation molecular spectral fingerprint was not identified in the urine of irradiated macaques in comparison to unirradiated control animals, but this study provides initial evidence and insights for future research.
Analysis of dynamic phosphorus magnetic resonance spectroscopy (31P MRS) data is often hindered by variability in data quality. A quality control (QC) pipeline developed by Naëgel (2023) introduced six key parameters to ensure reliable 31P MRS results in large clinical datasets. This study tested the transferability of this QC scoring (QCS_REF) to two different research sites equipped with 3T and 7T MR systems and different ergometers. Twelve groups with the focus on frail and elderly subjects and patients with neurodegenerative diseases were included. The application of QCS_REF limits led to the improvement of the statistical power in some patient groups, but to the exclusion of substantial data for all our groups and experimental settings at both 3T and 7T. Only 28% of all recovery and exercise period data at 3T and 21% at 7T passed QCS_REF inclusion criteria. Therefore, two new sets of quality control criteria, QCS1 and QCS2, were proposed, reflecting achieved SNR of individual MR signalsand the patient phenotype included. We showed that the transferability of the QCS_REF did not depend on the magnetic field, the coil, or localization scheme. The new QCS did not significantly influence the mean recovery and exercise time constants of each group compared to QCS_REF. We verified that six proposed key parameters were adequate for an objective assessment of the quality of dynamic 31P MRS measurement at 3T as well as 7T. However, the patient group characteristics and experimental set-up significantly affect the ability to meet dynamic 31P MRS quality control thresholds, supporting the use of flexible QC criteria for robust data acquisition across diverse clinical populations.
Hydrogenases are metalloenzymes that catalyze the reversible splitting of dihydrogen (H2), a clean and sustainable fuel. In this study, we investigate the reversible photodissociation and rebinding of an extrinsic carbon monoxide (CO) ligand at the active site of a [NiFe] model hydrogenase. CO acts as a catalytic inhibitor of the enzyme, whereas its photolysis restores an active state capable of H2 binding. Using UVpump-IRprobe spectroscopy in a multiple-probe configuration that allows covering picosecond to millisecond time scales, we characterize the reaction dynamics following CO photolysis. The results reveal a large temporal window between rapid CO dissociation and slow rebinding, enabling the detailed investigation of H2 binding and activation at the active site, unaffected by H2 mass transport limitation.
A diagnostic simulation code for charge exchange recombination spectroscopy has been developed, aiming at performing a Bayesian inference of the velocity distribution function from the measured charge exchange emission spectrum. A code has been written to reproduce the emission spectrum based on the input velocity distribution function and other experimental information, such as magnetic equilibrium, neutral beam density distribution, line of sight geometry, and others. A set of demonstrations of Bayesian inference has been accomplished for the setting of a simple problem: the parametric inference of an ion temperature profile. An uncertainty estimation based on a Bayesian model evidence is presented by finding the optimum hyperparameter.
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The photoacid 8-hydroxypyrene-1,3,6-trisulfonate (HPTS) is one of the most widely used fluorescent probes for studying proton transfer and local pH in systems from advanced materials to plants, environmental sensors to medicine. HPTS exists as two different species: the acid and its conjugate base, which lead to unique protonation-state-dependent translocation of the molecule when it is nanoconfined within anionic AOT reverse micelles. Using steady-state and time-resolved optical spectroscopy, molecular simulations, and IR solvation shell spectroscopy, we report that the protonated HPTS species associates strongly with the micelle interface via hydrogen bonding. In contrast, its deprotonated species resides in the micelle's aqueous interior. Our results show that photoexcitation of the acid species and its subsequent deprotonation leads the conjugate base to rapidly move away from the interface into the water pool. This light-induced translocation, an effect observed for a range of micelle sizes, challenges the prevailing view where molecular probes are assumed to be static reporters of their environments, remaining in a fixed location for the duration of an experiment. This is especially relevant for interpreting results in the numerous studies enlisting optical spectroscopy of HPTS to report on complex systems. Our findings reveal the potential for molecular probes as dynamic explorers capable of mapping environmental heterogeneity on the timescale of the very processes they are designed to measure.
Cellular lipids are wonders of biomolecular self-organization whose structure and dynamics are intimately connected with their functionality. Here we review the development and use of NMR spectroscopy in the study of lipid membranes. For liquid-crystalline bilayers, the structure is described by orientational order parameters, while the dynamics entail fluctuations about the mean geometry. Addressing the information gap between molecular structure, dynamics, and function involves magnetic resonance spectroscopy combined with X-ray and neutron scattering approaches. Cholesterol gives a crucial test in liquid-ordered (lo) membranes, where the bending rigidity oppositely affects solid-state NMR observables-the order parameters increase yet the relaxation rates decrease. By contrast, nonionic surfactants in the liquid-disordered (ld) state soften the bilayer and decrease the order parameters, thereby enhancing the spin relaxation. This enigma is explained by a model-free power-law that combines the mean-squared amplitudes and fluctuation rates. Collective modes appear on the mesoscale of the bilayer thickness and less, indicating how membrane elasticity emerges from atomistic-level interactions that drive the response to external forces. The unified power-law scaling shows how the bilayer fluidity corresponds to a hydrocarbon liquid of similar chain length. Magnetic resonance spectroscopy thus yields insights into properties that underlie bilayer phase transitions, curvature, and protein-lipid interactions.
This study explores the extraction and characterization of novel microcrystalline cellulose (MCC) from Artocarpus heterophyllus (jackfruit) seed outer peels and establish its suitability as a sustainable biomass source. MCC was obtained through a multi-step method consisting of alkaline treatment, acid hydrolysis, and oxidative bleaching. Structural and physicochemical features were analyzed using Fourier Transform Infrared Spectroscopy (FTIR), Ultraviolet-Visible (UV-Vis) spectroscopy, X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), and laser diffraction particle size analysis. FTIR analysis confirmed the removal of lignin and hemicellulose, while XRD revealed a high crystallinity index of 73.14%. UV-Vis analysis indicated the presence of chromophoric groups, suggesting possible relevance in biomaterial-related applications. TGA and DSC analyses demonstrated that the extracted MCC possessed thermal stability up to 256.6 °C along with distinct thermal transitions. AFM and SEM analyses revealed a fibrous surface morphology with rough texture and heterogeneous microparticle distribution. These findings confirm that MCC derived from jackfruit seed outer peel (JSOP) exhibits promising structural and thermal characteristics suitable for future bio-composite reinforcement applications.
The novel CaAl2Si2O8:Eu2+ (x = 0.5, 0.7, 1.0, 1.3 and 1.5 mol%) phosphor was successfully prepared by a simple combustion process. The phase and purity were investigated by X-ray diffraction (XRD), which shows a pure crystalline phase and matches the standard ICSD database file. The Rietveld refinement performed using an acceptable chi-square to determine additional structural parameters. The FTIR analysis is done to determine the functional group present in the given sample. UV-Vis diffuse reflectance spectroscopy used to determine the optical band gap reveals that the host is suitable for luminescence applications. The optical properties studied using Photoluminescence (PL) spectroscopy show a diffuse band in the blue-green region under near-UV excitation, due to the allowed 4f⁶5d¹ → 4f⁷ transitions of Eu²⁺ ions. The emission intensity varied with dopant concentration, with the highest at 1.0 mol%, followed by concentration quenching at higher concentrations. The surface morphology, determined using field-emission scanning electron microscopy (FE-SEM), revealed an agglomerated structure, and energy-dispersive spectroscopy (EDS) analysis confirmed the presence of all constituents in the host matrix. These findings reveal that the novel CaAl2Si2O8:Eu²⁺ phosphor is a promising luminescence material for white LED devices and solid-state lighting applications.
Nitrogen dioxide (NO2) is a highly toxic gas and a notorious respiratory irritant that contributes to the greenhouse effect and acid rain. Herein, we study the catalyst-free reduction of NO2 with boranes, silanes, and the hydrogen surrogates 1,4-cyclohexadiene and isopropyl alcohol, resulting in the selective formation of nitric oxide (NO). Selective NO generation was confirmed by electron paramagnetic resonance spectroscopy and low-temperature 15N{1H} nuclear magnetic resonance spectroscopy. Additionally, density functional theory calculations have been employed to probe the mechanism of these reductions.
This study investigated microplastic contamination in water, air, and soil within a municipal waste disposal site in Nakhon Si Thammarat, Thailand, during the dry and rainy seasons of 2023. A total of 51 environmental samples were collected, including leachate from treatment ponds, atmospheric total suspended particulates, and soil from both perimeter and internal landfill zones. Microplastics were extracted using organic digestion (H2O2/FeSO4) and density separation (ZnCl2), followed by identification and characterization using stereomicroscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and micro-Fourier transform infrared spectroscopy. The results showed that microplastic concentrations were higher in the primary leachate pond than in the final treatment pond. In the atmosphere, the active disposal area exhibited the highest levels of both total suspended particulates and microplastics compared to other sampling locations. Soil samples showed substantial contamination, particularly within active and legacy landfill zones, where elevated concentrations were observed. Seasonal variation was observed, with higher mean microplastic concentrations in wastewater and air during the dry season, while soil samples exhibited location-dependent patterns. Fragments were the dominant morphology across all environmental matrices (43-90%). The predominant colors were black and brown, while other colors were present in smaller proportions. A total of 16 polymer types were identified, with polyethylene, polypropylene, polyurethane, and polystyrene being the most common. SEM analysis revealed surface degradation features, including fractures and erosion, indicative of environmental weathering processes. These findings highlight municipal waste disposal sites as both significant sources and accumulation zones of microplastics, emphasizing the need for improved waste management strategies to reduce environmental dispersion and potential human exposure.
Repurposing expired vancomycin drug as an effective corrosion inhibitor for API 5 L X60 carbon steel (X60-CS) in 1 M hydrochloric acid (HCl). The pharmaceutical drugs that have expired are included in this category; they are a waste type that is usually burned rather than recycled. It's interesting to note that certain drug compounds exhibit characteristics that prevent corrosion in a variety of metals and corrosive liquids. This study aimed to comprehensively evaluate vancomycin based on concentration on X60-CS in acidic environments. A variety of techniques were employed to assess the corrosion-mitigating properties of vancomycin. To assess vancomycin's remarkable performance, we used extensive procedures, including weight loss (WL) and sophisticated electrochemical methods such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). By increasing vancomycin concentration, the inhibition efficiency will increase. The outcomes are remarkable: 94.2% (weight loss), 92.3% (polarization), and 95.3% (EIS) were the best inhibitory efficiencies attained at 298 K. With a good fit, vancomycin follows the Langmuir isotherm. The data obtained for activation energy increased from (50.82-80.35 kJ mol⁻¹), providing physical adsorption mechanisms in the interaction of the vancomycin inhibitor with the X60-CS surface. PDP results indicate that the corrosion current density (Icorr) decreases from 244 to 54 µA cm⁻² at inhibitor concentrations of 20 and 100 ppm, respectively. Along with weight-loss studies, surface analysis was carried out using Fourier Transform Infrared Spectroscopy (FTIR), Atomic Force Microscopy (AFM), Energy Dispersive X-Ray (EDX), and Scanning Electron Microscopy (SEM), and vancomycin adsorption on the X60-CS surface was evidenced. The quantum chemical parameters (ELUMO, EHOMO, and [Formula: see text]E) have a strong relationship with the protection efficiency of the investigated drug. The vancomycin inhibitor conformational adsorption modification on the iron surface was also predicted using molecular dynamics (MD) simulations. Results gained for all techniques used are in good agreement.
Hollow materials have designed with shell structures and porous cavities, as a new generation of functional materials, have shown remarkable performance in various fields. In this study, a magnetic, porous, and reusable nanocatalyst was designed and prepared. The CoNiFe2O4@C nanocatalyst was prepared through a multistep process. Initially, the magnetic trimetallic CoNiFe2O4 was prepared and followed by the deposition of a Silicon dioxide (SiO2) layer to form the CoNiFe2O4@SiO2 yolk-shell structure. The subsequent removal of the silica layer is resulted in the formation of the CoNiFe2O4@C yolk-shell magnetic nanocomposite. In this protocol, bisphenol derivatives were synthesized through a three-component reaction of aldehyde and 2-4-dimethylphenol in a ratio of 1:2 by using this prepared catalyst. The applications of bisphenols are included antioxidant, anticancer, anti-arthrosis, anti-inflammatory and antimicrobial properties. The identification of the prepared catalyst was carried out and reported using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), Energy-dispersive X-ray spectroscopy (EDS), Mapping, Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and Vibrating sample magnetometer (VSM) techniques. Also, the bisphenol products were identified using melting point, FT-IR, proton nuclear magnetic resonance (1H NMR) and carbon-13 nuclear magnetic resonance (13C NMR) analyses. The proposed approach presents multiple benefits such as; mild reaction conditions, ease of operation, reliable safety, excellent yield, effective purification of synthetic organic compounds, and minimal catalyst usage.
Surface-enhanced Raman spectroscopy (SERS) has emerged as a promising analytical tool for sensitive molecular detection in biomedical applications. In this study, star-shaped gold nanoparticles (AuNSTs) were employed as plasmonic substrates to enhance Raman signals for the analysis of hepatocellular carcinoma (HCC) directly from whole blood samples. The synthesized AuNSTs exhibited strong plasmonic resonance, enabling significant electromagnetic field localization and signal amplification. A reproducible Raman feature at ∼700 cm-1 was consistently observed in HCC samples following nanoparticle integration, while it was not detected in healthy controls under the same experimental conditions. Although the precise biochemical origin of this feature remains to be fully elucidated, it is likely associated with alterations in biomolecular composition and nanoparticle-biomolecule interactions at plasmonic hotspots. Exosomal isolation further improved spectral clarity; however, AuNST-assisted measurements on whole blood provided sufficient spectral differentiation without the need for complex preprocessing. Chemometric analysis using principal component analysis (PCA) demonstrated clear separation between healthy and HCC samples, supporting the potential of this approach for spectral discrimination. Overall, this study presents a rapid, minimally invasive, and label-free SERS-based platform for the detection of HCC-associated spectral features in whole blood, with potential applications in clinical diagnostics and biosensing. Further studies are required to validate specificity and elucidate the molecular origin of the observed Raman signals.
Maximizing the utilization efficiency of surface-active atoms is essential for improving carbon monoxide (CO) tolerance of hydrogen oxidation reaction (HOR) catalysts. However, conventional active-site regeneration strategies suffer from poor accessibility and low efficiency, hindering effective anion exchange membrane fuel cells (AEMFCs) operation under high-CO-concentration conditions. Here, we show a unique YbOx/Ni/C catalyst with Janus heterostructures that can significantly enhance the utilization efficiency of free active atoms by selectively adsorbing CO and promoting their directional elimination. Atomic resolution electron energy-loss spectroscopy (EELS) analysis reveals that the gradient electronic states in Janus heterostructures are generated between the interfaces of YbOx/Ni and Ni/C. Density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations further reveal that electron-rich Ni atoms near the Ni/YbOx interface serves as active sites for efficient removal of CO. In contrast, electron-deficient Ni atoms situated near the Ni/C interface facilitate the efficient HOR. The AEMFC with this anode catalyst achieves an impressive peak power density (PPD) of 702.0 mW cm-2 in H2-O2, maintains a PPD of 304.3 mW cm-2 even in 1000 ppm CO/H2-CO2-free air and continues to operate under harsh conditions with 10000 ppm CO, first showing the possibility to use crude hydrogen in AEMFCs.
Considering the significant importance of the phosphonate-mediated Horner-Wadsworth-Emmons (HWE) olefination reaction in organic synthesis, phosphamides are explored here as a mediator to perform P-N bond scission and simultaneous C═N condensation with a variety of substituted benzaldehydes through a HWE-type pathway under mild reaction conditions (60 °C and 12 h). Reaction kinetics, D-labeling (KIE: 1.23), Hammett study and characterization of reaction intermediates through in situ spectroscopy highlight that the deprotonation of "P(O)-NH" unit occurs in the very first step, followed by the C═N bond formation, and is preferred by electron-deficient substituents. Computationally optimized geometry of the phosphamides (PN-1 to PN-5) and their deprotonated form showed that N-H deprotonation shortens the P-N bond and elongates the P-O bond, indicating charge delocalization with partial P═N and P-O- character. Electron-deficient substituents stabilizes the monoanionic species, and PN-4 (-NH-Ph-Cl) exhibits the highest HOMO energy, suggesting enhanced nucleophilicity and reactivity toward benzaldehyde. The P-N bond dissociation of phosphamides via HWE-type reactions further enables a clean and selective approach for upcycling polyphosphamides into valuable imines. Notably, this method has been depicted as a sustainable path in selectively recovering cotton fabric from polyphosphamides, commonly used as flame-retardant materials, demonstrating its feasible depolymerization applications.
Date palm is a major agricultural crop in Oman. It generates substantial quantities of waste residues such as seeds which present significant opportunities for sustainable valorization. This study explores the fabrication of biodegradable HPMC-gelatin biocomposite films reinforced with microcrystalline cellulose (MCC) derived from the date seed waste. The MCC was extracted by acid-alkali treatment, bleaching, and ultrasonication. The extracted MCC was characterized by using Fourier transform infrared (FTIR) spectroscopy, Scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The characterization confirmed a cellulose I crystalline structure with a crystallinity index (Crl, %) of 59.5%. The MCC was incorporated into the polymer matrix at concentration of 0.2% to 0.6% (w/v). The developed films were evaluated for structural, mechanical, thermal, optical, and surface properties. The addition of MCC increased the film thickness (0.09-0.18 mm), haze (74.51-93.07%), and water contact angle (48.15°-86.79°). the higher MCC concentration (≥0.4%) led to particle aggregation that resulted in non-significant reduced tensile strength and transparency. Among all the formulations, the film containing 0.2% MCC showed the most balanced performance. This showed improved mechanical strength, moderate hydrophobicity, and minimal aggregation. 0.2% MCC showed the optimal performance with improved mechanical strength, moderate hydrophobicity, and minimal aggregation. These findings demonstrate that the ultrasonication-assisted MCC extraction from date seeds is a sustainable and efficient approach. The developed films showed strong potential for biodegradable food packaging applications.
All-aqueous emulsions (AAEs) provide an oil-free template for fabricating biomicrogels. We show that visible light irradiation promotes the Au3+-induced oxidation of tyrosine residues in high-density lipoprotein (HDL), accelerating HDL microgel formation within AAEs. Au3+ is concomitantly reduced to Au nanoparticles (AuNPs). Irradiance at 50 mW cm-2 yielded spherical microgels within ∼3 min, compared to ∼30 min without light (≈10×faster), and higher irradiance produced smaller particles. Fluorescence spectroscopy after AuNPs dissolution with potassium cyanide confirmed rapid di-tyrosine formation (λex ≈330 nm, λem ≈391 nm), with faster kinetics under illumination than in the dark. Wavelength tests indicated that broad visible light was more effective than single-band illumination, consistent with overlap of protein and Au3+/AuNP absorption. Importantly, illumination reduced the Au3+ requirement for gelation. Microgels formed at Au3+-to-HDL ratios as low as 100-300:1 under light, whereas ≈500:1 was needed in the dark. Confocal and electron microscopy verified spherical morphology. These results demonstrate a mild, fully aqueous, and light-assisted route for producing HDL microgels through AAE templating. The work establishes a strategy for HDL microgel formation, while potential applications in microfluidics, 3D bioprinting, and controlled delivery require further investigation.
Proton magnetic resonance imaging (MRI) and spectroscopy (MRS) are widely used in clinical and research applications. Recent interest in X-nuclei studies highlights their ability to provide additional biochemical information, but the intrinsically low X-nuclear signal-to-noise ratio (SNR) significantly increases scan time. Simultaneous (rather than serial) acquisition of multiple nuclei can significantly reduce experiment time, but most conventional MR systems lack this capability without modifications. We present a cost-effective system that enables simultaneous multinuclear imaging and spectroscopy on conventional MR spectrometers. Our approach offers enhanced flexibility for multinuclear experiments, supports multinuclear array receive capability, and maintains phase stability in the radio frequency (RF) chain. The proposed system comprised multiple transmit and receive mixing channels and a four-channel flexible local oscillator (LO) source. By interfacing with the spectrometer, simultaneous transmit and receive at different frequencies were achieved. The performance of the system was evaluated through bench measurement and phantom multinuclear MRI and MRS experiments. Transmit and receive channel isolation of better than 30 dB was measured on the bench. Simultaneous excitation and reception of 2H and 23Na gradient echo images were acquired, as well as interleaved excitation with simultaneous reception of 1H, 2H, and 23Na FIDs. Water-suppressed 1H and 31P MRS were performed simultaneously on phantoms mimicking muscle metabolites. Results across all experiments showed no signal-to-noise ratio (SNR) loss compared to single-frequency operation. The proposed system supports multiple variations of simultaneous experiments on conventional MRI systems, demonstrating its flexibility in configuring experiments with varying numbers of nuclei (2-4), different transmit modes (simultaneous or interleaved), and supporting receive array coils of up to 16 channels, while maintaining phase stability in the RF chain without the need for retrospective correction.
A computation-guided investigation of asymmetric donor-acceptor bridged stilbenes reveals structure-property relationships governing conical intersection (CI) accessibility and excited-state deactivation in aggregation-induced emission (AIE) luminogens. Although CIs play a central role in nonradiative decay, the molecular factors governing CI accessibility in AIE systems remain insufficiently understood. Here, we show that asymmetric donor-acceptor placement combined with bridge-controlled structural flexibility strongly influences CI accessibility and excited-state deactivation in push-pull alkylene-bridged stilbenes ([6]/[7]). Quantum-chemical analyses of 30 derivatives reveal substituent-dependent energetic trends associated with CI accessibility that can be rationalized by the relative energetic positions of the Franck-Condon and CI geometries. On the basis of these trends, representative derivatives, including DCBS[6], DCBS[7], DPB[7]C, and DPB[7]N, were synthesized together with reference compounds. Their photophysical properties generally correlate with the computed CI-accessibility trends, indicating that donor-acceptor asymmetry and bridge rigidity cooperatively influence excited-state deactivation and fluorescence suppression in solution. Time-resolved spectroscopy, post-relaxation PES analyses, and CI topology analyses further support the proposed relaxation pathways and suggest that substituent inversion alters CI energetics, topology, and nonadiabatic coupling. These findings provide mechanistic insight into substituent-dependent excited-state deactivation in bridged stilbenes.