Search Results (1,843)

Background: Knee osteoarthritis (KOA) is a major cause of pain, mobility limitation, and increased fall risk among older adults. Gait dysfunction, characterized by spatiotemporal and kinematic alterations, is a key functional consequence of KOA. While sagittal-plane gait deviations are well-established, multiplanar kinematic changes—particularly in the frontal and transverse planes—remain less clearly understood. This study aimed to compare three-dimensional gait characteristics between older adults with and without KOA. Methods: Ninety older adults (45 with KOA and 45 controls) completed gait assessments using a VICON™ motion capture system. Participants walked at a self-selected speed along a straight walkway without turning movements during data collection. Spatiotemporal parameters and lower-limb joint kinematics (hip, knee, and ankle) were recorded during key gait phases: initial contact, mid-stance, toe-off, and mid-swing. Group comparisons were performed using independent t-tests with statistical significance set at p < 0.05. Results: Compared with controls, participants with KOA demonstrated significantly slower gait velocity (p = 0.001), reduced cadence (p = 0.020), shorter stride length (p = 0.011), increased step time (p = 0.006), prolonged double support time (p = 0.009), and reduced single support time (p = 0.012). Kinematic analysis revealed greater knee adduction at initial contact (p = 0.001), reduced hip adduction (p = 0.002) and greater knee adduction (p = 0.003) during mid-stance, and increased ankle plantarflexion at toe-off (p = 0.004) in the KOA group. No significant between-group differences were observed during the mid-swing phase. Conclusions: Older adults with KOA exhibit distinct spatiotemporal and multiplanar kinematic gait alterations, particularly during weight-bearing phases. These changes may reflect adaptive gait patterns associated with joint dysfunction rather than definitive compensatory mechanisms. Three-dimensional gait analysis may provide valuable biomechanical insights to support early identification of mobility impairments and inform targeted rehabilitation planning in individuals with KOA. Full article

Maternal Smoking During Pregnancy (MSDP) remains a major source of fetal toxicant exposure. We applied adductomics to profile reactive adducts at the human serum albumin cysteine-34 (HSA-Cys³⁴) locus, which integrates longer-term exposures. HSA-Cys³⁴ adducts formed by acrylonitrile and ethylene oxide, two tobacco-related toxicants previously linked to smoking in adults, were quantified and compared with cotinine and MSDP status. Their relationships with other reactive adducts were also examined. Neonatal dried blood spots (DBS) from 110 children were analyzed. Cotinine and 55 Cys³⁴ adducts were measured by Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS). Associations were evaluated using linear regression, chi-square tests, and principal component analysis. Eighteen adducts differed significantly by MSDP status after Bonferroni correction (p ≤ 9.1 × 10⁻⁴). S-acrylonitrile was markedly elevated in exposed newborns, including those whose mothers reported smoking cessation after early pregnancy (p < 0.001). S-acrylonitrile correlated with 31 adducts related to oxidative stress and thiol metabolism, whereas cotinine correlated with eight. S-ethylene oxide, though detectable in DBS, showed no consistent association with MSDP. Adductomics analysis of newborn DBS sensitively captures molecular signatures of prenatal tobacco exposure and related oxidative stress. Acrylonitrile adducts appear to better reflect cumulative MSDP exposure than cotinine, highlighting the utility of adductomics for improved exposure assessment and mechanistic insight. Full article

Assessing hip adductor muscle strength is important for identifying weakness or side-to-side imbalances associated with groin injury risk. Although the Copenhagen adductor exercise is widely used to evaluate adductor function, the quantification of strength-related outcomes using inertial sensors integrated in smartphones during this task has not been systematically examined. This study aimed to evaluate the reliability of a smartphone-based Copenhagen adductor field test and its associations with established isometric hip adductor strength assessments. Twenty amateur male football players (21.1 ± 3.2 years) completed two laboratory sessions separated by one week. The reliability of the smartphone-based Copenhagen test was assessed for endurance-related outcome (repetition count) and strength-related outcomes (mean repetition time and peak velocity) using intraclass correlation coefficients (ICC), standard error of measurement (SEM), and minimum detectable change (MDC). Participants also performed unilateral and bilateral isometric hip adductor tests using load cells to obtain isometric peak force (IPF) and rate of force development at 150 ms (RFD150). Associations were examined using Pearson correlation coefficients. The smartphone-based Copenhagen test showed ICC point estimates ranging from 0.63 to 0.83, although several 95% confidence intervals were relatively wide (ICC = 0.63–0.83; SEM = 6.7–18.5%). Endurance-related outcomes were not significantly associated with IPF or RFD150. In contrast, peak velocity showed low-to-moderate correlations with RFD150 (r = 0.48–0.63) and moderate correlations with IPF (r = 0.50–0.64; p < 0.05). These findings suggest that the peak velocity obtained during the Copenhagen adductor test may provide a practical field-based complement to conventional isometric assessments. However, given the moderate strength of the observed associations and the measurement error of peak velocity, these outcomes should be interpreted with caution and warrant further investigation. Full article

The utilization and chemical transformation of carbon dioxide remains a pressing problem in modern chemistry. Numerous experimental and theoretical studies have focused on the interaction of CO₂ with amines. In this work, quantum chemical density functional theory (DFT) calculations of equilibrium geometries, energies, electronic and vibrational characteristics of CO₂-sensitive mono-, di-, tris-hydroxyamidines and their associates were carried out by the B3LYP/6-31G(d, p) method. The harmonic vibrational frequencies were scaled and compared with the experimental FTIR spectra for supporting wavenumber assignments. Natural bond orbital (NBO) analysis of the atomic charges and charge delocalization was employed to investigate the nature of hydrogen bonding in hydroxyamidine associates. We also used the intrinsically polarizable continuum model (IEFPCM), and the DFT-D3 method was applied to account for dispersion effects during associate formation. Using the 6-311+G(2d, p) basis set for tris-hydroxyamidine, and its adducts, a comparative analysis of the experimental and calculated ¹H NMR spectra was performed. Here, we considered non-trivial sites of carbon dioxide absorption and hydroxyamidine protonation, which, to our knowledge, have hardly been considered by other authors. Present DFT results agree rather well with the experimental data and support new insight into the formation of the PIL structure. Full article

Objective: The objective of this study was to explore the motion characteristics and movement strategies of the hip and knee joints in overweight individuals during sit-to-stand (STS) transfers using statistical parametric mapping (SPM). Methods: Twenty subjects were divided into an overweight group (n = 10) and a normal-weight group (n = 10) based on body mass index (BMI). The Qualisys infrared motion capture system and Kistler three-dimensional force platform were used for motion data collection, and Visual 3D and Matlab were used to calculate the angles and torque indicators of the lower limb hip and knee joints. Results: During the STS process, the maximum hip flexion angle of the overweight group was smaller than that of the control group (Z = −1.83, p = 0.043, r = 0.39), while the maximum abduction and external rotation angles were greater than those of the control group (Z = −2.15, p = 0.022, r = 0.46; Z = −2.02, p = 0.028, r = 0.48). SPM analysis showed that during the 0–52% phase of the hip joint in the frontal plane, the abduction amplitude of the overweight population was greater than that of the normal population (p < 0.05). The minimum external rotation angle of the knee joint was less than that of the control group (F(1,18) = 9.135, p = 0.043). The peak internal adduction and abduction torque of the hip joint in the overweight group was greater than that of the control group (Z = 2.37, p = 0.017, r = 0.54). Conclusions: Compared with the normal-weight population, the overweight population exhibited distinct motion characteristics of the hip and knee joints during the STS, with particularly pronounced differences in the hip joint. To maintain stability during STS, the overweight population adopts a compensatory movement strategy featuring a wider base of support via hip abduction and increased muscular torque to control frontal plane stability, which imposes greater functional loads on the hip joint. BMI-related movement characteristics should be studied in young adults under controlled experimental conditions, and future studies are needed to verify whether similar patterns exist in older adults. Full article

The purpose of this work is to investigate the binding state of inorganic elements to flavonoid components in aqueous extract of Silybum marianum (SM) seeds, as well as the antioxidant activity of the extract. This study employed reversed-phase high-performance liquid chromatography (RP-HPLC) to separate silymarin flavonoids in boiling water decoction of SM seeds, and collected the post-column effluent in the segments according to the retention time of seven main silymarin flavonoid components. Inductively coupled plasma mass spectrometry (ICP-MS) was subsequently utilized to quantify nine inorganic elements (As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Zn) in the collected HPLC fractions of the decoction. Meanwhile, electron paramagnetic resonance spectroscopy (EPR) was employed to assess the free radical scavenging activity of aqueous extract of SM seeds, using the signal intensity changes of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and DMPO-OH• adducts as quantitative metrics. The results showed that essential trace elements (Cu, Fe, Mn, Zn) mainly existed as inorganic ions or strong polar forms in the tea-like infusion, with weak binding to flavonoid compounds. On the other hand, the aqueous extract exhibited significant •OH scavenging capacity, with a scavenging rate of 95% against •OH generated by continuous 5 min ultraviolet irradiation of H₂O₂ aqueous solution. This study provides experimental evidence for the development of SM as a food–medicine dual-purpose resource, proposing that consumption of SM seed tea represents a facile and effective approach to supplement trace elements and intake silymarin for enhancing endogenous antioxidant defense. Full article

Carnosine (CAR), an endogenous histidine-containing dipeptide, exhibits antioxidant and anti-inflammatory activity in various experimental models; however, its molecular mechanism of action remains poorly understood. Here, we demonstrate that the Michael adduct between CAR and 4-hydroxy-2-nonenal (HNE), which has been detected in previous studies in both in vitro and in vivo settings, mediates its bioactivity, particularly its antioxidant and anti-inflammatory responses, through Nrf2 activation. The CAR–HNE adduct was synthesized and its physicochemical, metabolic, and biological properties were evaluated. CAR–HNE exhibited high stability in biological matrices and retained the ability to transfer HNE to thiol nucleophiles at a slow rate under physiologically relevant conditions, consistent with electrophile-mediated Nrf2 activation. This kinetic behavior limits the cytotoxicity typically associated with free HNE while preserving the redox signaling capacity. CAR–HNE induced dose-dependent Nrf2 activation and NF-κB inhibition in cell-based assays without the hormetic toxicity observed for free HNE. Mechanistically, CAR–HNE may act as a redox-tunable electrophilic reservoir, restoring nucleophilic tone and modulating redox-sensitive transcription factors. In vivo, CAR–HNE attenuated DSS-induced colitis more effectively than equimolar doses of either carnosine or HNE alone. Proteomic analyses revealed modulation of canonical Nrf2-dependent antioxidant pathways. Our findings suggest a conceptual shift in carnosine biology: rather than acting as a classical antioxidant or carbonyl quencher, carnosine functions as a precursor of redox-active electrophilic adducts that transduce anti-inflammatory and antioxidant responses via controlled RCS signaling. Full article

Upper extremity impairments often lead to reduced joint range of motion (ROM), making reliable assessment essential for rehabilitation planning. This study investigated the within-day and between-day reliability of the Microsoft Kinect V2 depth camera for active upper extremity ROM assessment in 30 healthy adults. Ten predefined shoulder and elbow movements were recorded, and joint angles were computed using a custom vector-based algorithm. Within-day reliability ranged from moderate to excellent (ICC: 0.754–0.953), while between-day reliability ranged from moderate to good (ICC: 0.654–0.881). Absolute reliability varies substantially across movements. The SEM% values ranged from 2.1% to 17.3% within-day and from 2.8% to 23.6% between-day. The between-day MDC values were particularly high for certain movements (e.g., >20° for shoulder extension and >50° for elbow flexion), indicating limited sensitivity to detect small clinical changes. Additionally, shoulder adduction could not be reliably analyzed in 36.7% of participants due to self-occlusion-related tracking instability, highlighting a practical limitation of the Kinect V2 for certain upper extremity movements. These findings suggest that Kinect V2-based ROM assessment demonstrates acceptable reliability for large-amplitude planar movements under controlled conditions but shows substantial limitations for rotational and occlusion-prone tasks. The device may be suitable for research or screening applications; however, caution is warranted when interpreting small changes in clinical settings. Full article

The effect of LiPF₆ acidity, represented by LiPF₆·xHF adduct formation and its interaction with fluoride species, on the surface reactivity and stability of LiPF₆ was investigated using density functional theory (DFT) calculations performed with the Vienna Ab initio Simulation Package (VASP). The exchange–correlation energy was described using the Perdew–Burke–Ernzerhof (PBE) functional within the Generalized Gradient Approximation (GGA). Four distinct surface terminations of the (003) and (101) facets—F4–P2–Li, P2–F3–Li, Li2–F3–P, and F4–Li2–P were systematically examined. Surface and adsorption energies were evaluated together with key electronic descriptors, including the work function, dipole moment, electron localization function (ELF), electrostatic potential, band structure, and density of states, to elucidate the mechanisms governing adsorption and stability. The (101) facet exhibits a pronounced susceptibility to HF-induced solvation, driven by enhanced surface polarity, a low work function, and intermolecular H–F interactions at lithium-exposed terminations. In contrast, the thermodynamically dominant (003) facet shows greater resistance to HF interaction, with adsorption remaining predominantly molecular and progressing toward deliquescence only at elevated HF concentrations. Fluorine-rich and charge-balanced terminations on both facets display enhanced stability, characterized by high work functions, minimal ELF redistribution, and suppressed charge transfer. Full article

This study elucidates the regulatory mechanisms of methoxy substitution and photoexcitation on the antioxidant properties of pterostilbene (PTE) versus resveratrol (RES), employing a combined approach of multi-reference calculations, density functional theory (DFT), time-dependent DFT (TD-DFT), and molecular docking. Spectral analysis indicates that trans isomers exhibit a significant redshift (~13 nm) and have oscillator strengths more than double those of cis isomers. A pivotal difference in photoisomerization kinetics was identified: methoxy substitution drastically lowers the isomerization barrier for RES, indicating that PTE is more readily photoisomerized. Regarding radical scavenging, thermodynamic data confirm that Hydrogen Atom Transfer (HAT) and Radical Adduct Formation (RAF) are spontaneous pathways; notably, the O1 site of trans-PTE serves as the optimal hydrogen donor. Conceptual DFT (CDFT) analysis reveals that photoexcitation triggers a dramatic electronic reconfiguration, particularly for cis-PTE, whose ionization potential in the S1 state drops sharply to 4.66 eV, accompanied by an increased softness of 0.38 eV⁻¹, rendering it a highly potent electron donor. Furthermore, molecular docking demonstrates that trans-PTE robustly occupies the Keap1 Kelch pocket (binding energy: −7.478 kcal/mol) to inhibit Nrf2 binding via its favorable planar geometry. Full article

To improve understanding of anterior cruciate ligament (ACL) injuries, this study investigated the effect of menstrual cycle (MC) phase on ACL injury risk factors in elite female team sport athletes with and without urinary incontinence (UI). Additionally, associations between endogenous sex hormones, MC-related symptoms, and these risk factors were investigated. Ten elite female athletes (24.2 ± 3.6 years, BMI 23.2 ± 1.3 kg/m², 10.9 ± 1.8 training hours/week) completed three testing sessions across three MC phases, determined using the three-step method. Assessments included static and dynamic postural control and hip strength. Mixed-model ANOVA and canonical correlation analyses evaluated the effects of MC phase, UI, hormones, and performance. A significant interaction between MC phase and UI was observed for single-leg sway area with eyes closed (p = 0.036), and UI was associated with a higher hip adduction:abduction ratio (p = 0.037). No further significant interaction between UI and MC phase was observed. Moreover, hormones explained 16.5% of the variance in risk factors, while subjective symptoms explained 24.5%. Lower progesterone was associated with higher symptoms, lower estradiol and progesterone with reduced strength and poorer postural control, and higher testosterone with greater strength. Although limited by its pilot design, menstrual symptoms, more than MC phases, may influence performance and injury risk, supporting the potential value of systematic symptoms monitoring. Full article

Mass spectrometry-based analysis of post-translational modifications (PTMs) is a key strategy for characterizing protein regulation and identifying disease-associated targets, with endogenous PTMs serving as biomarkers for disease diagnosis and therapeutic response. More recently, chemical proteomic strategies have adapted PTM-focused workflows to measure engagement of covalent and photoactivatable small-molecule probes, expanding the scope of ligand discovery for these disease-associated targets. This review provides an overview of mass spectrometry-based PTM analysis workflows, including LC–MS/MS acquisition and post-acquisition data processing, with an emphasis on how modification-specific physicochemical properties influence PTM detection and identification. Common analytical challenges that limit PTM identification, including variable MS/MS fragmentation behavior and modification site localization, are discussed using modifications such as phosphorylation and photoaffinity labeling probe adducts as representative examples. Recent advances in acquisition strategies and computational tools that improve spectral quality and confidence in PTM assignment are also summarized. Additionally, approaches for the analytical validation of modification events, such as metabolic labeling strategies, are described. Together, this review outlines key considerations, capabilities, and limitations of MS-based PTM profiling and provides a framework for interpreting PTM datasets to support their effective integration into downstream biochemical and disease target validation studies. Full article

Background: It is known that the α-hydroxyphosphonates and their derivatives may have potential biological activity. Methods: Within the prominent class of α-hydroxyphosphonates, α-hydroxy-alkylphosphonates and their derivatives were prepared as new representatives in the hope of obtaining biologically active species. During our work the Pudovik reaction, acylation and phosphinoylation/phosphorylation methods were used. The new compounds were characterized by NMR and MS spectroscopy. The antiproliferative effects were tested on U266 (myeloma multiplex) and A2058 (melanoma) cells. Results: Ethyl methyl ketone–dialkyl phosphite and secondary phosphine oxide adducts were synthesized by the Pudovik reaction on the earlier analogy of acetaldehyde– and acetone adducts. The hydroxyphosphonates and hydroxyphosphine oxides were acylated and phosphinoylated/phosphorylated. Due to the steric hindrance in the case of the preparation of the acetone–and ethyl methyl ketone–diethyl phosphite adducts, a two-step procedure was elaborated that was also suitable for the thiophosphinoylation of the adducts. A part of the α-hydroxyphosphonates could be successfully methanesulfonylated. The new derivatives prepared were tested on myeloma and melanoma cells, and it was found that the antiproliferative activity is primarily driven by phosphinoylation, particularly by diphenylthiophosphinoylation. The most promising compound, the diphenylthiophosphinoylated hydroxyphosphine oxide, reduced the viability of the U266 cells to less than 20% after a treatment with 100 µM concentration in a long-term experiment. Conclusions: A subset of the synthesized α-hydroxyphosphonate derivatives exhibited cytotoxic activity, supporting further structural optimization to identify compounds with enhanced biological efficacy. Full article

Phytic acid (PA), owing to its strong acidity and multidentate metal-chelating properties, readily forms multiple adduct/complex ions in mass spectrometry and is prone to pronounced matrix effects, resulting in complicated spectra and compromised sensitivity and quantitative robustness, which poses a major challenge for rapid and accurate PA quantification. Herein, we developed a rapid quantitative method for PA based on trimethylsilyldiazomethane (TMSD) methyl-ester derivatization coupled with paper spray mass spectrometry (PS–MS). PA was derivatized with TMSD to yield the methylated product (PA-Me), and the derivative solution was purified via “post-derivatization nitrogen blow-down followed by water reconstitution”, thereby markedly reducing background interference. In positive-ion mode, the stable sodium adduct ion [PA-Me+Na]⁺ (m/z 851.04) was used as the quantifier, enabling fast quantification with selected ion monitoring (SIM). PS–MS was performed with a 15 μL spotting volume and methanol/water (90/10, v/v, containing 0.1% formic acid) as the spray solvent, allowing rapid analysis without chromatographic separation. The method exhibited good linearity over 0.125–30 μg/mL (R² ≥ 0.9965), with a limit of detection (LOD, S/N = 3) of 0.080 μg/mL and a limit of quantification (LOQ, S/N = 10) of 0.270 μg/mL. The intra-day and inter-day precision values were both < 10% (RSD), and recoveries ranged from 87.2% to 122.4%. This LC-free strategy features low solvent consumption and high analytical throughput, and was validated using rice bran protein and rice bran polysaccharide samples, providing technical support for rapid screening and quality control of PA in complex food/plant matrices. Full article

Muscular fitness is a key component of health and athletic performance, and isometric strength is a widely used indicator. This study reports an agreement-based validation of the Isometric Strength Measurement Device (ISOMETRO) for upper-limb isometric tension measurements under controlled laboratory conditions. Twenty-one healthy young amateur rock climbers (11 men and 10 women) performed four upper-limb tensile tests (shoulder adduction at 90°, shoulder adduction at 60°, shoulder extension at 90°, and elbow extension at 90°). Agreement with an independent criterion device was evaluated using a force plate, while a series-connected load cell was used as an internal consistency check of the measurement chain. Linear mixed-effects models showed that ISOMETRO strongly predicted force plate values (β = 0.999, SE = 0.002, p < 0.001), with a marginal R² > 0.99. Bland–Altman analysis indicated negligible bias (−0.08 N) and narrow limits of agreement (−4.97 to 4.81 N), and concordance was excellent (CCC ≥ 0.996). The series-connected load cell comparison also showed near-unity agreement (β = 0.998, SE = 0.003, p < 0.001), supporting internal measurement chain integrity. These findings support excellent agreement between ISOMETRO and force plate measurements for upper-limb tensile isometric testing along the vertical axis in young amateur rock climbers under controlled laboratory conditions. However, given the specific sample characteristics and the strictly vertical laboratory configuration, these results should not be generalized to other populations, joint angles, force directions, or non-laboratory environments without further validation. Further studies are needed to confirm performance in more diverse contexts and to establish reliability for repeated-measurement applications. Full article