Search Results (5,971)

The highly squinted mode, as an operational configuration of synthetic aperture radar (SAR), fulfills specific remote sensing demands. Under equivalent conditions, it necessitates a higher pulse repetition frequency (PRF) than the side-looking mode but produces inferior imaging quality, thereby constraining its widespread application. By applying the sparse SAR imaging method to highly squinted SAR systems, imaging quality can be enhanced while simultaneously reducing PRF requirements and expanding swath. Hyperparameters in sparse SAR imaging critically influence reconstruction quality and computational efficiency, making hyperparameter optimization (HPO) a persistent research focus. Inspired by HPO techniques in the deep unfolding network (DUN), we modified the iterative soft-thresholding algorithm (ISTA) employed in fast sparse SAR reconstruction based on approximate observation operators. Our adaptation enables adaptive regularization parameter tuning during iterations while accelerating convergence. To improve the robustness of this enhanced algorithm under realistic SAR echoes with noise, we integrated hypergradient descent (HD) to automatically adjust the ISTA step size after regularization parameter convergence, thereby mitigating overfitting. The proposed method, named Hyper-ISTA-GHD, adaptively selects regularization parameters and step sizes. It achieves high-precision, rapid imaging for highly squinted SAR. Owing to its training-free iterative minimization framework, this approach exhibits superior generalization capabilities compared to existing DUN methods and demonstrates broad applicability across diverse SAR imaging modes and scene characteristics. Simulations show that the hyperparameter selection and reconstruction results of the proposed method are almost consistent with the optimal values of traditional methods under different signal-to-noise ratios and sampling rates, but the time consumption is only one-tenth of that of traditional methods. Comparative experiments on the generalization performance with DUN show that the generalization performance of the proposed method is significantly better than DUN in extremely sparse scenarios. Full article

Milk production and quality are increasingly affected worldwide by rising ambient temperatures associated with climate change, with heat stress (HS) representing one of the major environmental challenges for dairy cattle. HS alters physiological and metabolic processes, leading to significant changes in milk composition, particularly in regions exposed to prolonged summer heat. The Temperature–Humidity Index (THI) is widely used to assess the degree of thermal discomfort and its impact on dairy performance. This study investigated the effects of heat stress on milk quality parameters in a dairy herd managed under identical conditions, comprising Romanian Black Spotted (RBS, Holstein strain) and Romanian Spotted (RS, Simmental strain) cows. Descriptive statistics were performed using the SAVC for Windows program, while differences between means were evaluated using the t-test in GraphPad Prism 9. Milk quality traits were significantly affected when THI values exceeded 73, with a consistent decline observed from early summer onwards. In the RBS breed, milk protein content decreased significantly compared with spring values, reaching 3.25% (p < 0.0001) in 2023 and 3.35% (p < 0.01) in 2024. Similar trends were recorded in the RS breed, with minimum protein values of 3.10% (p < 0.0001) and 3.19% (p < 0.0001). Fat content, casein concentration, and milk urea levels also showed highly significant HS-related changes (p < 0.0001). Overall, heat stress negatively affected milk quality, while the RS breed appears less affected under the studied conditions than the RBS breed. Full article

This study develops a comprehensive workflow integrating Headspace Solid-Phase Microextraction Gas Chromatography–Mass Spectrometry (HS-SPME-GC-MS) with advanced supervised machine learning to authenticate the botanical origin of honeys from five distinct floral sources—coriander, orange blossom, astragalus, rosemary, and chehelgiah. While HS-SPME-GC-MS combined with traditional chemometrics (e.g., PCA, LDA, OPLS-DA) is well-established for honey discrimination, the application and direct comparison of Random Forest (RF), eXtreme Gradient Boosting (XGBoost), and Neural Network (NN) models represent a significant advancement in multiclass prediction accuracy and model robustness. A total of 57 honey samples were analyzed to generate detailed volatile organic compound (VOC) profiles. Key chemotaxonomic markers were identified: anethole in coriander and chehelgiah, thymoquinone in astragalus, p-menth-8-en-1-ol in orange blossom, and dill ester (3,6-dimethyl-2,3,3a,4,5,7a-hexahydrobenzofuran) in rosemary. Principal component analysis (PCA) revealed clear separation across botanical classes (PC1: 49.8%; PC2: 22.6%). Three classification models—RF, XGBoost, and NN—were trained on standardized, stratified data. The NN model achieved the highest accuracy (90.32%), followed by XGBoost (86.69%) and RF (83.47%), with superior per-class F1-scores and near-perfect specificity (>0.95). Confusion matrices confirmed minimal misclassification, particularly in the NN model. This work establishes HS-SPME-GC-MS coupled with deep learning as a rapid, sensitive, and reliable tool for multiclass honey botanical authentication, offering strong potential for real-time quality control, fraud detection, and premium market certification. Full article

Alpine forests are key regulators of soil biogeochemical cycles, yet the extent to which forest type constrains soil microbial diversity and soil quality in high-elevation regions remains insufficiently resolved. Here, we assessed how contrasting alpine forest types influence the taxonomic composition and diversity of soil microbial communities, identified the dominant environmental drivers, and evaluated soil quality along the southern slope of the Qilian Mountains. Six forest types were examined, including four monospecific stands (Picea crassifolia, QQ; Betula spp., HS; Juniperus przewalskii, YB; and Pinus tabuliformis, YS) and two mixed formations (mixed conifer–broadleaf, ZKHJ; and mixed broadleaved, KKHJ). Bacterial and fungal communities were characterized using Illumina high-throughput sequencing, while structural equation modeling (SEM) was used to identify primary drivers of diversity and principal component analysis (PCA) was applied to construct the minimum data set (MDS) for soil quality evaluation. Mixed forests consistently exhibited higher bacterial and fungal alpha diversity than pure stands. Environmental gradients were the strongest positive drivers of microbial diversity, whereas soil chemical properties and vegetation-related biotic factors exerted partially negative effects. Soil quality index (SQI) values ranked as follows: KKHJ (0.55) > ZKHJ (0.49) > YB (0.48) > HS (0.46) > YS (0.44) > QQ (0.43). The mixed broadleaved forest reached Grade IV (upper-intermediate level) soil quality, whereas the other forest types were classified as Grade III (intermediate). Mixed forests showed stronger capacities for organic matter accumulation and nutrient retention. These findings indicate that promoting mixed forest stands is critical for improving soil structure, nutrient retention, and microbial diversity in this alpine region. Accordingly, forest management should prioritize the development of mixed forests to enhance overall soil quality. Full article

Oregano (Origanum vulgare L.), basil (Ocimum basilicum L.), rosemary (Rosmarinus officinalis L.), yarrow (Achillea millefolium L.), and thyme (Thymus vulgaris L.) are aromatic medicinal plants rich in bioactive volatile compounds with antioxidant, antimicrobial, and anti-inflammatory properties. This study presents a simple, solvent-free, and eco-friendly headspace GC-MS method for VOC profiling. Optimized thermal pretreatment (40–90 °C) enhanced compound detection, particularly at 70–90 °C, without loss of reproducibility. The approach lowers analytical costs and waste generation, supporting green analytical practices and the sustainable valorization of medicinal herbs as natural functional ingredients. Full article

Background/Objectives: The Rapid Access Chest Pain Assessment Clinic (RACPAC) streamlines the evaluation of low-to-intermediate risk chest pain and helps avoid unnecessary hospitalisation. Biomarkers {low-density lipoprotein cholesterol (LDL-c) and high-sensitivity C-reactive protein (hsCRP)} are established cardiovascular risk markers. Yet, their diagnostic value for stable coronary artery disease (CAD) in RACPAC remains uncertain. Therefore, we aimed to determine the utility of biomarkers in predicting the presence of CAD in the RACPAC setting. Methods: A retrospective cohort study of consecutive adults attending RACPAC between 2012 and 2021. Multivariable logistic regression and receiver operating characteristic analyses, including prespecified subgroup and sensitivity analyses, were used to evaluate the predictive value of hsCRP and LDL-c for the presence of CAD detected on CT Coronary Angiogram (CTCA) or Treadmill Stress Echocardiography (TSE) as the primary outcome. Results: 3569 patients were included in this study, the mean age was 55.4 ± 11.3 years, and 48.8% were female; 37.4% had hypertension, while 39.5% had dyslipidemia. The mean LDL-c was 3.1 ± 0.9 mmol/L, and the median hsCRP was 1.9 mg/L (IQR 0.9 to 3.8). The regression analysis for the primary outcome showed that neither hsCRP nor LDL-c predicted CAD on CTCA (hsCRP OR 1.00, 95% CI 0.99 to 1.02, p = 0.70; LDL-c OR 1.16, 95% CI 0.97 to 1.39, p = 0.11). On TSE, hsCRP was not associated with CAD, while LDL-c showed an inverse association with CAD (hsCRP OR 0.98, 95% CI 0.83 to 1.00, p = 0.78; LDL-c OR 0.44, 95% CI 0.21 to 0.87, p = 0.02). ROC analysis showed AUC 0.553 for log hsCRP (95% CI 0.501 to 0.606) and 0.508 for LDL-c (95% CI 0.450 to 0.566), with p = 0.2756. Conclusions: In a large real-world RACPAC cohort, neither elevated hsCRP nor LDL-c predicted the presence of coronary artery disease in the rapid access chest pain clinic (RACPAC) cohort. In contrast, CT coronary angiography (CTCA) demonstrated superior diagnostic accuracy compared with treadmill stress echocardiography (TSE) in this setting. Full article

Objectives: Investigating and comparing the micro-tensile bond strength (µTBS) of etch-and-rinse (ER) or self-etch (SE) adhesives on sound (s) and eroded (e) human (H) and bovine (B) dentin. Methods: Twenty-four human and bovine teeth were divided into eight groups (n = 6) and coronally ground down, exposing their dentin. Two groups of human (HeER + HeSE) and bovine teeth (BeER + BeSE) were subjected to erosive challenges (citric acid (pH 2.7), 10 × 2 min per day for five days, and stored in artificial saliva). Groups HsER + HeER and BsER + BeER were treated with an etch-and-rinse adhesive (OptiBond FL), and groups HsSE + HeSE and BsSE + BeSE were treated with a self-etch adhesive (OptiBond All-in-One), followed by buildups with a composite restorative material. After seven days of storage in tap water, µTBS was determined and failure type analysis was performed. Data were evaluated using two-way ANOVA and Tukey’s post hoc tests at a level of significance of α = 0.05. Results: Using etch-and-rinse adhesive, sound human dentin (HsER) showed the significantly highest µTBS (p < 0.05) compared to eroded human (HeER) and sound and eroded bovine dentin (BsER + BeER). For sound human and bovine specimens (HsSE + BsSE), there was no significant difference (p ≥ 0.05) in µTBS when self-etch adhesive was applied, as well as in the eroded specimens (HeSE + BeSE). Conclusions: Within the limitations of this study, it can be concluded that for the etch-and-rinse approach, it is not recommended to substitute human dentin with bovine dentin. When using the specific self-etch adhesive used in the present study, bovine dentin can be used to substitute human dentin, as they showed comparable µTBS. Full article

Structural insights into methyl-coenzyme M reductase from Methanobrevibacter ruminantium (M. ruminantium) has implications for methane mitigation strategies. Methanogenesis in ruminants is a major contributor to global greenhouse gas emissions, primarily driven by the rumen archaeon M. ruminantium. Central to this process is methyl-coenzyme M reductase (Mcr), an enzyme that catalyzes the final step of methane production. Despite its significance as a chemogenetic target for methane mitigation, the high-resolution structure of M. ruminantium Mcr has remained elusive. Here, we employed homology modeling and CDOCKER simulations within the CHARMM force field to elucidate the structural and functional features of the M. ruminantium Mcr/ligand complexes. We characterized two distinct states: the reduced Mcr_oxi-silent state bound to HS-CoM and CoB-SH, and the oxidized Mcr_silent state bound to the heterodisulfide CoM-S-S-CoB. Alanine-scanning mutagenesis identified 71 and 62 key residues per active site for each state, respectively, revealing the fundamental determinants of structural stability and substrate selectivity on the Ni-F₄₃₀ cofactor. Furthermore, structure-based pharmacophore modeling defined essential features (AAADDNNN and AAADDNN) that drive ligand binding. These findings provide a high-resolution molecular framework for the rational design of specific Mcr inhibitors, offering a robust starting point for developing broad-spectrum strategies to suppress enteric methane emissions. Full article

Lung cancer (LC) remains the leading cause of cancer-related death worldwide, largely due to late-stage diagnosis and the limited performance of current screening strategies. In this preliminary study, headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) was used to comprehensively characterize the urinary volatilome of LC patients and healthy controls (HCs), with the dual aim of defining an LC-associated volatilomic signature and identifying volatile organic metabolites (VOMs) with discriminatory potential. A total of 56 VOMs spanning multiple chemical classes were identified, revealing a distinct metabolic footprint between groups. LC patients exhibited markedly increased levels of terpenoids and aldehydes, consistent with heightened oxidative stress, including lipid peroxidation, and perturbed metabolic pathways, whereas HCs showed a predominance of sulphur-containing compounds and volatile phenols, likely reflecting active sulphur amino acid metabolism and/or microbial-derived processes. Multivariate modelling using partial least squares-discriminant analysis (PLS-DA, R² = 0.961; Q² = 0.941; p < 0.001), supported by hierarchical clustering, demonstrated robust and clearly separated group stratification. Among the detected VOMs, octanal, dehydro-p-cymene, 2,6-dimethyl-7-octen-2-ol and 3,7-dimethyl-3-octanol displayed the highest discriminative power, emerging as promising candidate urinary biomarkers of LC. These findings provide proof-of-concept that HS-SPME/GC-MS-based urinary volatilomic profiling can capture disease-specific molecular signatures and may serve as a non-invasive approach to support the early detection of LC, warranting validation in independent cohorts and integration within future multi-omics diagnostic frameworks. Full article

Background: Gamification is a promising approach to support rehabilitation, but implementing new devices after hand surgery (HS) faces challenges, especially in patient motivation and compliance. Technology-based, personalized solutions may encourage patients to perform gamified exercises consistently. This study investigated the impact of a tablet-based gamified hand-mobilization system on functional outcomes after HS compared to standard finger-expander training. Methods: Forty inpatients at BG Klinikum Duisburg were randomly assigned to a gamified or control group. Both groups underwent four weeks of stationary rehabilitation. Outcomes were assessed using the Disabilities of Arm, Shoulder, and Hand questionnaire (DASH), SF-36 health-related quality of life, and a visual analog scale (VAS) at pre- (T0) and post-training (T1). Tablet use frequency and duration were recorded. Results: DASH scores improved significantly over time (F(1.55, 58.85) = 16.36, p < 0.001, partial η² = 0.137) with no Group or Time × Group effects (p > 0.40), exceeding the MCID in both groups. SF-36 MCS, PCS, and VAS pain also improved over time (all p < 0.05) with no between-group differences (p > 0.40). Exercise duration differed (p = 0.007), but training frequency did not. Conclusions: Both gamified and conventional rehabilitation programs led to clinically meaningful improvements in hand function after hand surgery. No significant differences were observed between groups, indicating that the tablet-based system was feasible and well-accepted but not superior to standard training. Full article

Biomimetic microstructured surfaces offer a promising passive strategy for drag reduction in marine and aerospace applications. This study employs computational fluid dynamics (CFD) simulations to systematically investigate the drag reduction performance and mechanisms of groove-type microstructures, addressing both geometry selection and dimensional optimization. Three representative geometries (V-groove, blade-groove, and arc-groove) were compared under identical flow conditions (inflow velocity 5 m/s, Re = 7.5 × 10⁵) using the shear-stress-transport (SST k-ω) turbulence model, and the third-generation Ω criterion was employed for threshold-independent vortex identification. The results establish a clear performance hierarchy: blade-groove achieves the highest drag reduction rate of 18.2%, followed by the V-groove (16.5%) and arc-groove (14.7%). The analysis reveals that stable near-wall microvortices form dynamic vortex isolation layers that separate the high-speed flow from the groove valleys, with blade grooves generating the strongest and most fully developed vortex structures. A parametric study of blade-groove aspect ratios (h⁺/s⁺ = 0.35–1.0) further demonstrates that maintaining h⁺/s⁺ ≥ 0.75 preserves effective vortex-isolation layers, whereas reducing h⁺/s⁺ below 0.6 causes vortex collapse and performance degradation. These findings establish a comprehensive design framework combining geometry selection (blade-groove > V-groove > arc-groove) with dimensional optimization criteria, providing quantitative guidance for practical biomimetic drag-reducing surfaces. Full article

Objectives: Polycystic ovary syndrome (PCOS) is a heterogeneous disorder with diverse pathogenetic mechanisms and clinical manifestations. Phenotype D PCOS is characterized by oligomenorrhoea and polycystic ovaries without hyperandrogenism. Altered adipokine profiles may contribute to reproductive and metabolic disturbances. Chemerin is an adipokine involved in inflammatory and metabolic processes. It remains unclear whether altered chemerin levels in PCOS reflect metabolic dysfunction alone or are directly associated with hyperandrogenism. The aim of this study was to compare serum chemerin levels in women with normoandrogenic PCOS and a control group. Methods: This cross-sectional preliminary study included 49 women with phenotype D PCOS and 40 healthy, age- and body mass index (BMI)-matched controls. Anthropometric, biochemical, hormonal parameters, and serum chemerin concentrations were assessed. Results: Serum chemerin concentrations did not differ significantly between the groups. In the PCOS group, the 95% confidence interval ranged from 198.61 to 234.37, while in the controls, it ranged from 187.13 to 216.21. In women with PCOS, chemerin showed significant positive correlations with weight, BMI, waist and hip circumference, total adipose tissue, and both gynoid and android fat content. Positive correlations were also observed with highly sensitive C-reactive protein (hs-CRP), insulin, glucose, triglycerides, and Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), and a negative correlation was found with high-density lipoprotein (HDL) cholesterol. Chemerin was weakly negatively correlated with sex hormone binding globulin (SHBG) and positively correlated with the free androgen index (FAI). In the control group, chemerin correlated positively with CRP, insulin, triglycerides, total and gynoid adipose tissue, and negatively correlated with HDL cholesterol and SHBG. Conclusions Although chemerin levels did not differ from controls, chemerin was associated with metabolic and inflammatory markers in both groups. These findings should be considered preliminary due to the limited sample size. Chemerin may reflect metabolic and inflammatory status rather than hyperandrogenism in normoandrogenic PCOS. Full article

This study evaluates the effect of fermentation on the volatile composition of plant-based dry-cured sausages. The goal was to understand how different lactic acid bacteria (LAB) strains influence the aroma profile during ripening. Five experimental groups were tested, including uninoculated controls and sausages inoculated with selected LAB strains or a commercial starter. A total of 51 volatile compounds were identified and tracked over an 11-day fermentation period using HS-SPME-GC-MS. Results showed that LAB fermentation reduced compounds associated with off-flavors, such as aldehydes and sulfur compounds, and promoted the formation of volatiles responsible for pleasant aromas like buttery and fruity notes. Specific LAB strains, especially Lacticaseibacillus casei 116, showed strong potential in improving the volatile profile of plant-based meat analogs. These findings suggest that fermentation using selected LAB can enhance the sensory quality of plant-based sausages, helping them better mimic traditional meat products. Full article

High electrostrain, excellent thermal stability, and low hysteresis are critical requirements for advanced high-precision actuators. However, simultaneously achieving these synergistic properties in lead-free ferroelectric ceramics remains a significant challenge. In this work, a targeted B-site doping strategy was employed to develop novel lead-free (0.99-x)BaTiO₃-xBaZrO₃-0.01Bi(Zn_2/3Nb_1/3)O₃ (BT-xBZ-BZN, x = 0–0.2) ceramics. Systematic investigation identified optimal Zr⁴⁺ substitution at x = 0.1, which yielded an outstanding combination of electromechanical properties. For this optimal composition, a high unipolar electrostrain (S_max = 0.11%) was achieved at 50 kV/cm, accompanied by an ultra-low hysteresis (H_S = 1.9%). Concurrently, a large electrostrictive coefficient (Q₃₃ = 0.0405 m⁴/C²) was determined, demonstrating excellent thermal robustness with less than 10% variation across a broad temperature range of 30–120 °C. This superior comprehensive performance is attributed to a composition-driven evolution from a long-range ferroelectric to a pseudocubic relaxor state. In this state, the dominant electrostrictive effect, propelled by reversible dynamics of polar nanoregions (PNRs), minimizes irreversible domain switching. These findings not only present BT-xBZ-BZN (x = 0.1) as a highly promising lead-free candidate for high-precision, low-loss actuator devices, but also provide a viable design strategy for developing high-performance electrostrictive materials with synergistic large strain and superior thermal stability. Full article

Early prevention of pathological changes underlying gastric cancer (GC) development is a critical strategy, offering the most effective opportunity to limit malignant progression and improve patient outcomes. We have previously demonstrated that Helicobacter pylori (Hp) (cagA⁺vacA⁺) contributes to GC development by activating gastric fibroblasts toward CAF-like phenotype, eliciting aggressive, cancer stem cells (CSCs)-related malignant transformation of LGR5⁺ normal epithelial cells. A key mediator of these processes appears to be the NF-κB/STAT3 axis. Therefore, our aim was to investigate the protective role of hydrogen sulfide (H₂S) as a potential novel strategy for counteracting Hp-induced fibroblast reprogramming. Human fibroblasts were infected with Hp (cagA+vacA+) for 120 h. The fast-releasing H₂S donor NaHS (50, 100, 200 and 400 µM) was added every 24 h. Activation markers, corresponding signaling pathways, H₂S release and activities of H₂S-metabolizing enzymes were determined. NaHS reduced Hp-induced fibroblast activation and their pro-inflammatory, pro-tumorigenic markers, which was associated with the inhibition of NF-κB/STAT3 axis and Twist expression. Additionally, it modulated sulfur metabolism while preserving sulfur-enzyme homeostasis. NaHS limited Hp adhesion (high doses), reduced reinfection-induced activation and increased sensitivity of Hp to metronidazole. These findings suggest that H₂S signaling may represent a modulatory factor of NF-κB/STAT3-driven inflammatory responses during Hp infection and warrant further investigation. Full article