Search Results (65)

Background/Objectives: An unexplainably high millimolar (~3 mM) concentration of adenosine triphosphate (ATP), herein designated as nucleoside triphosphate (NTP), exists in the crystalline lens even though all of the known functions of NTP combined require only micromolar (μM) concentrations. Since the lens is one of the most metabolically quiescent tissues in the body and the retina is one of the most metabolically active tissues in the body, we compared their phosphorus metabolomics and related metabolic indices that measure their metabolic health status. As such, the purpose of this report was to compare the NTP concentrations in lenticular and retinal tissues and the metabolic indices that include NTP as well as their phosphorus-31 spectral modulus (PSM). Methods: Known phosphatic metabolic profiles of rat lenses and retinas were compared and quantified in mole % phosphorus using phosphorus-31 nuclear magnetic resonance spectroscopy. Metabolic indices measuring health status, where ATP is a principal component, were calculated, including the PSM. Results: In this secondary analysis, the NTP concentration calculated in the lens was 41.0% of the total phosphate detected, whereas it was similarly 37.6% in the sensory retina. The PSM values were 1.28 for the lens and similarly 1.42 for the retina. Conclusions: Due to the lens tissue’s low quiescent metabolic activity, one might expect the NTP concentration to be lower in the lens than in the highly metabolically active retina: a similar difference is expected in the PSM. However, this was not the case with the mM concentrations of NTP in both the lens (≥2.3 mM) and the retina (2.4 mM). The similarly high mM NTP concentration coupled with the PSM-calculated measure of metabolic health in these tissues is a novel finding. The novel findings of such similarly high concentrations of NTP in these metabolically diverse eye tissues further support and are consistent with the hypothesized role of NTP as a hydrotrope, preventing protein aggregation resulting in age-related cataractogenesis and age-related macular degeneration. Full article

This study presents and systematizes a high-reliability measurement and technological dataset suitable for prediction-based validation of the Spent Fuel Interim Storage Facility (SFISF) of the Paks Nuclear Power Plant. The primary objective of this dataset is not the validation of a general-purpose software tool, but to establish a reproducible experimental basis for the objective and quantitative validation of a three-dimensional, facility-scale heat transfer and buoyancy-driven flow model of the SFISF, developed using the finite difference method (FDM), in a passively cooled system where heat conduction, thermal radiation, and natural convection simultaneously occur. The applied measurement systems (SMAS, CTRS, and the in-house developed CFEPR), their spatial arrangement, accuracy characteristics, as well as data post-processing and the generation of model execution inputs are described in detail. Special emphasis is placed on the functional separation of the available data into initialization data, model execution data, and independent validation datasets, ensuring that model assessment does not rely on calibration or parameter fitting. Furthermore, the estimation of decay heat generated by the stored fuel assemblies is presented using both a standard correlation method (ANSI/ANS-5.1) and isotope inventory-based calculations, and the discrepancies between these approaches are treated as input uncertainties and sensitivity analysis factors. The spectral solar load is considered based on the ASTM G-173 reference spectrum, while during cloudy periods an effective irradiance estimation derived from on-site lux measurements is applied. The results indicate that the available measurement and technological information is sufficient for supporting reproducible, transparent, and quantitative validation studies of the three-dimensional numerical model of the SFISF, as well as for assessing the impact of dominant input uncertainties. Full article

The secretome of ESKAPE pathogens contains numerous bioactive molecules that play a key role in pathogenesis and the formation of an immunosuppressive microenvironment. However, analyzing this complex chemical composition presents significant methodological challenges. In this study, we propose a combined approach integrating chromatographic fractionation of cell-free supernatants with Raman spectroscopy to deconstruct the secretome of the clinically relevant Gram-negative pathogen—Enterobacter spp. Chromatographic separation of the Enterobacter spp. supernatant into seven fractions reduced spectral congestion and enabled identification of fraction 3 as having a unique metabolite profile, enriched in peptides (including tryptophan- and tyrosine-containing structures), nucleic acids, polysaccharides, and putative glutathione-like compounds. Notably, fraction 3 lacked markers of phenylalanine and sterol-like lipids, highlighting its distinct composition. Compared to conventional mass spectrometry and nuclear magnetic resonance, our hybrid strategy offers minimal sample preparation, preserves sample integrity for repeated analysis, avoids ionization bias, and is fully compatible with aqueous biological matrices—critical advantages for profiling labile or low-abundance metabolites in native secretomes. These findings demonstrate that the combination of preparative chromatography and Raman spectroscopy effectively resolves complex bacterial secretomes and identifies fractions potentially carrying key virulence or signaling functions. Full article

Introduction: As DNA image cytometry and DNA image histology serve as valuable tools in clinical tumor pathology, the need for precise and accurate DNA amount measurements is crucial. This study describes the process of employing spectral unmixing on Thionin-stained slides as a means of reducing refraction effects introduced in the image, during imaging, due to changes in the refraction index within the tissue being imaged. Methods: A correction method that reduces refraction effects on the DNA quantitation measurements by making use of the spectrally limited absorption properties exhibited by Thionin relative to the more spectrally uniform effects of tissue refraction as a function of wavelength. Results: Spectral unmixing enables an improved estimate of DNA amount at every pixel and a potentially truer representation of the actual distribution of the DNA within individual cell nuclei. Conclusions: Spectral unmixing is a valuable computational technique widely used in histology and cytology research. By reducing refraction-based optical artifacts in the image, it enhances the accuracy of DNA quantitation, minimizes variability, and improves the discriminating ability of nuclear DNA organization as quantified by texture features. Full article

Background: Preperimetric glaucoma (PPG) is characterized by structural optic nerve damage without detectable functional impairment. Optical coherence tomography (OCT) is increasingly utilized to monitor glaucoma, though its reliability can be compromised by lens opacities. This study investigates retinal nerve fiber layer (RNFL) thickness changes after cataract surgery in patients with and without PPG, aiming to assess potential diagnostic inaccuracies due to cataract-induced imaging artifacts. Methods: Thirty eyes from 30 patients undergoing cataract surgery were analyzed, divided into two groups: Group 1 (n = 15) without glaucoma and Group 2 (n = 15) with PPG diagnosed using the Global Glaucoma Staging System. RNFL thickness was measured using Spectral-Domain OCT before and one month after phacoemulsification. Statistical analysis was performed using SPSS v23.0. Results: Postoperative RNFL thickness increased significantly in both groups, with a greater mean change in the PPG group (mean increase: 13 µm vs. 7 µm in controls; p < 0.00001). The greatest changes were observed in the inferior quadrants (p < 0.001). Image quality improved by approximately 34% post-surgery (p < 0.001). Despite higher postoperative RNFL values, none of the PPG eyes were reclassified as normal. Conclusions: In eyes with mild nuclear cataract, lens-related signal attenuation reduces absolute RNFL values but, in this cohort, had negligible impact on structural diagnostic classification. OCT-based structural findings in early glaucoma should therefore be interpreted with caution in the presence of cataract—recognizing that measurement bias may alter thickness values without changing PPG classification. Cataract surgery improves OCT reliability and can refine subsequent glaucoma assessment. Full article

Background/Objectives: Historically, echocardiographic imaging of the right heart has been challenging because its abnormal geometry is not conducive to reproducible anatomical and functional assessment. With the development of advanced echocardiographic techniques, it is now possible to complete an integrated assessment of the right heart that has fewer assumptions, resulting in increased accuracy and precision. Echocardiography continues to be the first-line imaging modality for diagnostic analysis and the management of acute and chronic right heart failure because of its portability, versatility, and affordability compared to cardiac computed tomography, magnetic resonance imaging, nuclear scintigraphy, and positron emission tomography. Virtually all echocardiographic parameters have been well-validated and have demonstrated prognostic significance. The goal of this narrative review of the echocardiographic parameters of the right heart chambers and hemodynamic alterations associated with right ventricular dysfunction is to present information that must be acquired during each examination to deliver a comprehensive assessment of the right heart and to discuss their clinical significance in right heart failure. Methods: Using a literature search in the PubMed database from 1985 to 2025 and the Cochrane database, which included but was not limited to terminology that are descriptive of right heart anatomy and function, disease states involving acute and chronic right heart failure and pulmonary hypertension, and the application of conventional and advanced echocardiographic modalities that strive to elucidate the pathophysiology of right heart failure, we reviewed randomized control trials, observational retrospective and prospective cohort studies, societal guidelines, and systematic review articles. Conclusions: In addition to the conventional 2-dimensional echocardiography and color, spectral, and tissue Doppler measurements, a contemporary echocardiographic assessment of a patient with suspected or proven right heart failure must include 3-dimensional echocardiographic-derived measurements, speckle-tracking echocardiography strain analysis, and hemodynamics parameters to not only characterize the right heart anatomy but to also determine the underlying pathophysiology of right heart failure. Complete and point-of-care echocardiography is available in virtually all clinical settings for routine care, but this imaging tool is particularly indispensable in the emergency department, intensive care units, and operating room, where it can provide an immediate assessment of right ventricular function and associated hemodynamic changes to assist with real-time management decisions. Full article

The gut microbiota, a complex community of microorganisms, plays a crucial role in gastrointestinal (GI) health, influencing digestion, metabolism, immune function, and the gut–brain axis. Dysbiosis, or an imbalance in microbiota composition, is associated with GI disorders, including irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), and colorectal cancer (CRC). Conventional microbiota analysis methods, such as next-generation sequencing (NGS) and nuclear magnetic resonance (NMR), provide valuable insights but are often expensive, time-consuming, and destructive. Raman spectroscopy (RS) is a non-invasive, cost-effective, and highly sensitive alternative. This analytical technique relies on inelastic light scattering to generate molecular “fingerprints”, enabling real-time, marker-free analysis of microbiota composition and metabolic activity. This review explores the principles, sample preparation techniques, and advancements in RS, including surface-enhanced Raman spectroscopy (SERS), for microbiota research. RS facilitates identifying microbial species, analysing key metabolites like short-chain fatty acids (SCFA), and monitoring microbiota responses to dietary and therapeutic interventions. The comparative analysis highlights RS’s advantages over conventional techniques, such as the minimal sample preparation, real-time capabilities, and non-destructive nature. The integration of RS with machine learning enhances its diagnostic potential, enabling biomarker discovery and personalised treatment strategies for GI disorders. Challenges, including weak Raman signals and spectral complexity, are discussed alongside emerging solutions. As RS technology advances, mainly through portable spectrometers and AI integration, its clinical application in microbiota diagnostics and personalised medicine is poised to transform GI healthcare, bridging microbiota research with practical therapeutic strategies. Full article

This paper overviews gas phase experiments with respect to one fundamental part of nuclear magnetic resonance (NMR) spectra. Indirect spin-spin coupling is an important parameter of NMR spectra and is observed as the splitting of spectral signals. A molecule containing two different magnetic nuclei (e.g., hydrogen HD, HT, or DT) exhibits this interaction in an external magnetic field measured as the spin-spin coupling parameter, ⁿJ(NN′). Modern quantum chemical methods allow the precise calculation of spin-spin coupling, but it is never easy because ⁿJ(NN′) is modified by temperature and intermolecular interactions. Accurate calculations can be performed only for small isolated molecules. NMR spectroscopy can deliver measurements of spin-spin couplings for isolated molecules if ⁿJ(NN′) parameters are observed in the gas phase as a function of density. The extrapolation of such measurements to the zero-density limit permits ⁿJ₀(NN′) determination free from intermolecular interactions. The latter technique can also be applied to liquid vapors in molecules like acetonitrile or water. Spin-spin couplings across one chemical bond (¹J₀(NN′)) are the largest and most important for theoretical modeling. The present review reports numerous ¹J₀(NN′) parameters recently measured by multinuclear NMR spectra of gaseous samples. Full article

The use of biomass feedstocks for producing high-value-added chemicals is gaining significant attention in the academic community. In this study, near-infrared carbon dots (NIR-CDs) with antimicrobial and bioimaging functions were prepared from Epigynum auritum branches and leaves using a novel green synthesis approach. The spectral properties of the synthesized NIR-CDs were characterized by ultraviolet–visible (UV-Vis) absorption and fluorescence spectroscopy. The crystal structures of the NIR-CDs were further characterized by high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), and X-ray diffraction (XRD). The NIR-CDs exhibited minimal toxicity, excellent biocompatibility, and high penetrability in both in vivo and in vitro environments, making them ideal luminescent probes for bioimaging applications. Moreover, the antimicrobial activity of NIR-CDs was tested against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), showing significant bacterial growth inhibition. The antimicrobial effect is likely attributed to the NIR-CDs disrupting the cell membrane integrity, leading to the leakage of the intracellular contents. Therefore, NIR-CDs hold promise as fluorescent bioimaging probes and antimicrobial agents. Full article

Cathinone and its synthetic derivatives belong to organic compounds with narcotic properties. Their structural diversity and massive illegal use create the need to develop new analytical methods for their identification in different matrices. NMR spectroscopy is one of the most versatile methods for identifying the structure of organic substances. However, its use could sometimes be very difficult and time-consuming due to the complexity of NMR spectra, as well as the technical limitations of measurements. In such cases, molecular modeling serves as a good supporting technique for interpreting ambiguous spectral data. Theoretical prediction of NMR spectra includes calculation of nuclear magnetic shieldings and sometimes also indirect spin–spin coupling constants (SSCC). The quality of theoretical prediction is strongly dependent on the choice of the theory level. In the current study, cathinone and its 12 fluorinated derivatives were selected for gauge-including atomic orbital (GIAO) NMR calculations using Hartree–Fock (HF) and 28 density functionals combined with 6-311++G** basis set to find the optimal level of theory for ¹H, ¹³C, and ¹⁹F chemical shifts modeling. All calculations were performed in the gas phase, and solutions were modeled with a polarized-continuum model (PCM) and solvation model based on density (SMD). The results were critically compared with available experimental data. Full article

The development of a suitable set of input ground motions is crucial for dynamic time history analyses. The US Nuclear Regulatory Commission (NRC) requires that these motions generate response spectra closely matching the plant’s design spectrum. Additionally, the NRC recommends verifying the motions’ power spectral densities (PSDs) against a target function to ensure sufficient energy across all frequencies. Current NRC guidelines in Standard Review Plan (SRP) provide a general method for creating target PSDs for any design spectrum. However, this method does not explicitly consider the influence of strong motion duration on the relationship between PSD and response spectrum. This article proposes an improved approach that incorporates the expected strong motion duration into the target PSD generation process. The method first constructs a Fourier amplitude spectrum (FAS) compatible with both the design spectrum and the expected strong motion duration. Subsequently, a large set of synthetic motions based on this FAS is used to construct the target PSD function. It is shown that current target PSD functions tabulated in SRP 3.7.1 implicitly infer an expected strong motion duration of approximately 9 s. The proposed method can be used to construct target PSDs tailored to different strong motion durations. Full article

With the rapid development of nuclear energy, the contamination of environmental water systems by uranium has become a significant threat to human health. To efficiently remove uranium from these systems, three types of silica-based polyamine resins—SiPMA-DETA (SiPMA: silica/poly methyl acrylate; DETA: diethylenetriamine), SiPMA-TETA (TETA: triethylenetetramine), and SiPMA-TEPA (TEPA: tetraethylenepentamine)—were successfully prepared, characterized, and evaluated in batch experiments. Characterization results showed that the silica-based polyamine resins were successfully prepared, and they exhibited a uniform shape and high specific surface area. SiPMA-DETA, SiPMA-TETA, and SiPMA-TEPA had nitrogen contents of 4.08%, 3.72%, and 4.26%, respectively. Batch experiments indicated that these adsorbents could efficiently remove uranium from aqueous solutions with a pH of 5–9. The adsorption kinetics of U(VI) were consistent with the pseudo-second-order model, indicating that the adsorption process was chemisorption and that adsorption equilibrium was achieved within 10 min. SiPMA-TEPA, with the longest polyamine chain, exhibited the highest adsorption capacity (>198.95 mg/g), while SiPMA-DETA, with the shortest polyamine chain, demonstrated the highest U(VI) adsorption efficiency (83%) with 100 mM Na₂SO₄. SiPMA-TEPA still removed over 90% of U(VI) from river water and tap water. The spectral analysis revealed that the N-containing functional groups on the ligand were bound to anionic uranium–carbonate species and possibly contributed to the adsorption efficiency. In general, this work presents three effective adsorbents for removing uranium from environmental water systems and thus significantly contributes to the field of environmental protection. Full article

Adenosine triphosphate (ATP) has a high intracellular millimolar concentration (ca. 2.4 mM) throughout the phylogenetic spectrum of eukaryotes, archaea, and prokaryotes. In addition, the function of ATP as a hydrotrope in the prevention of protein aggregation and maintenance of protein solubilization is essential to cellular, tissue, and organ homeostasis. The ³¹P spectral modulus (PSM) is a measure of the health status of cell, tissue, and organ systems, as well as of ATP, and it is based on in vivo ³¹P nuclear magnetic resonance (³¹P NMR) spectra. The PSM is calculated by dividing the area of the ³¹P NMR integral curve representing the high-energy phosphates by that of the low-energy phosphates. Unlike the difficulties encountered in measuring organophosphates such as ATP or any other phosphorylated metabolites in a conventional ³¹P NMR spectrum or in processed tissue samples, in vivo PSM measurements are possible with NMR surface-coil technology. The PSM does not rely on the resolution of individual metabolite signals but uses the total area derived from each of the NMR integral curves of the above-described spectral regions. Calculation is based on a simple ratio of the high- and low-energy phosphate bands, which are conveniently arranged in the high- and low-field portions of the ³¹P NMR spectrum. In practice, there is essentially no signal overlap between these two regions, with the dividing point being ca. −3 δ. ATP is the principal contributor to the maintenance of an elevated PSM that is typically observed in healthy systems. The purpose of this study is to demonstrate that (1) in general, the higher the metabolic activity, the higher the ³¹P spectral modulus, and (2) the modulus calculation does not require highly resolved ³¹P spectral signals and thus can even be used with reduced signal-to-noise spectra such as those detected as a result of in vivo analyses or those that may be obtained during a clinical MRI examination. With increasing metabolic stress or maturation of metabolic disease in cells, tissues, or organ systems, the PSM index declines; alternatively, with decreasing stress or resolution of disease states, the PSM increases. The PSM can serve to monitor normal homeostasis as a diagnostic tool and may be used to monitor disease processes with and without interventional treatment. Full article

This paper presents a combined analysis of muon neutrino and antineutrino charged-current cross sections at kinematics of relevance for the T2K, MINERvA and MicroBooNE experiments. We analyze the sum, difference and asymmetry of neutrino versus antineutrino cross sections in order to get a better understanding of the nuclear effects involved in these processes. Nuclear models based on the superscaling behavior and the relativistic mean field theory are applied, covering a wide range of kinematics, from hundreds of MeV to several GeV, and the relevant nuclear regimes, i.e., from quasileastic reactions to deep inelastic scattering processes. The NEUT neutrino-interaction event generator, used in neutrino oscillation experiments, is also applied to the analysis of the quasielastic channel via local Fermi gas and spectral function approaches. Full article

The semi-inclusive cross-section of two-nucleon emission induced by neutrinos and antineutrinos is computed by employing the relativistic mean field model of nuclear matter and the dynamics of meson-exchange currents. Within this model, we explore a factorization approximation based on the product of an integrated two-hole spectral function and a two-nucleon cross-section averaged over hole pairs. We demonstrate that the integrated spectral function of the uncorrelated Fermi gas can be analytically computed, and we derive a simple, fully relativistic formula for this function, showcasing its dependency solely on both missing momentum and missing energy. A prescription for the average momenta of the two holes in the factorized two-nucleon cross-section is provided, assuming that these momenta are perpendicular to the missing momentum in the center-of-mass system. The validity of the factorized approach is assessed by comparing it with the unfactorized calculation. Our investigation includes the study of the semi-inclusive cross-section integrated over the energy of one of the emitted nucleons and the cross-section integrated over the emission angles of the two nucleons and the outgoing muon kinematics. A comparison is made with the pure phase-space model and other models from the literature. The results of this analysis offer valuable insights into the influence of the semi-inclusive hadronic tensor on the cross-section, providing a deeper understanding of the underlying nuclear processes. Full article