Search Results (2,363)

Corrugated insect wings inspire biomimetic aerodynamic design, yet their behaviour at low and transitional Reynolds numbers remains not fully understood. This study presents a three-dimensional computational analysis of flow over an infinite corrugated wing across Reynolds numbers from 10 to 10,000 and angles of attack from −5 to 20°, with emphasis on spanwise effects. An expanded verification and validation procedure ensured numerical reliability. At the lowest Reynolds numbers, the flow is steady and largely two-dimensional, with localised recirculation zones. As Reynolds numbers or angles of attack increase, the flow transitions to periodic vortex shedding, and three-dimensional structures appear. At a Reynolds number of ten thousand, periodic shedding occurs at zero degrees incidence, indicating a shift toward turbulent or bluff body-like behaviour. The examined corrugated profile does not exhibit a lift-to-drag benefit over smooth aerofoils in steady gliding, although root section corrugation helps delay separation in transitional regimes. This behaviour reflects mechanisms used by dragonflies to maintain stable gliding despite textured wings. By extending flow regime classification, the study identifies conditions where two-dimensional assumptions fail and highlights the influence of spanwise flow structures. These findings deepen understanding of insect wing aerodynamics and support biomimetic design of future wings. Full article

Signal transducer and activator of transcription 3 (STAT3) is a transcription factor that regulates a broad spectrum of genes with oncogenic potential, thereby serving as a critical driver of tumorigenesis. Canonical STAT3 function is mediated through tyrosine phosphorylation, which enables dimerization and transcriptional activation, whereas serine phosphorylation of STAT3 has a postulated role in fine-tuning canonical functions and contributes to non-canonical roles as well. One of the transcriptional targets of STAT3 is the anti-apoptotic B-cell lymphoma 2 (Bcl-2) protein, itself subject to phosphorylation-dependent regulation. In this study, we investigated the effect of chelidonine, an alkaloid component of Chelidonium majus L., on STAT3/Bcl-2 signaling in human T leukemia/lymphoma cells, reported to have numerous effects in common with microtubule-targeting agents (MTAs). Flow cytometry and confocal microscopy revealed that chelidonine transiently increased both serine-phosphorylated STAT3 (pSer-STAT3) and Bcl-2 levels in a distinct subpopulation of cells, with near-complete overlap between the affected cells. This effect appeared at least partially independent of interleukin-2 (IL-2) and was associated with the M-phase of the cell cycle, as indicated by enhanced phosphorylation of Bcl-2 at serine 70 and nuclear morphology characteristic of mitosis. Our study provides the first single-cell evidence that STAT3 and Bcl-2 undergo concurrent serine phosphorylation as a response to chelidonine treatment, with the effect tightly linked to the M-phase. Full article

Wetlands in dryland regions are rapidly degrading under the combined effects of climate change and human regulation, yet long-term, seasonally resolved assessments of surface water extent (SWE) and its dynamics remain scarce. Here, we map and analyze seasonal surface water extent (SWE) over the period 2000–2024 in the Ile River Delta (IRD), south-eastern Kazakhstan, using Landsat TM/ETM+/OLI data within the Google Earth Engine (GEE) framework. We integrate multiple indices using the modified Normalized Difference Water Index (mNDWI), Automated Water Extraction Index (AWEI) variants, Water Index 2015 (WI2015), and Multi-Band Water Index (MBWI) with dynamic Otsu thresholding. The resulting index-wise binary water maps are merged via ensemble agreement (intersection, majority, union) to delineate three SWE regimes: stable (persists most of the time), periodic (appears regularly but not in every season), and ephemeral (appears only occasionally). Validation against Sentinel-2 imagery showed high accuracy F1-Score/Overall accuracy (F1/OA ≈ 0.85/85%), confirming our workflow to be robust. Hydroclimatic drivers were evaluated through modified Mann–Kendall (MMK) and Spearman’s (r) correlations between SWE, discharge (D), water level (WL), precipitation (P), and air temperature (AT), while a hybrid ensemble–occurrence framework was applied to identify degradation and transition patterns. Trend analysis revealed significant long–term declines, most pronounced during summer and fall. Discharge is predominantly controlled by stable spring SWE, while discharge and temperature jointly influence periodic SWE in summer–fall, with warming reducing the delta surface water. Ephemeral SWE responds episodically to flow pulses, whereas precipitation played a limited role in this semi–arid region. Spatially, area(s) of interest (AOI)-II/III (the main distributary system) support the most extensive yet dynamic wetlands. In contrast, AOI-I and AOI-IV host smaller, more constrained wetland mosaics. AOI-I shows persistence under steady low flows, while AOI-IV reflects a stressed system with sporadic high-water levels. Overall, the results highlight the dominant influence of flow regulation and distributary allocation on IRD hydrology and the need for ecologically timed releases, targeted restoration, and transboundary cooperation to sustain delta resilience. Full article

Interesting new correlations and unidirectional properties of two bosonic modes under the influence of the environment appear when the modes are mutually coupled through the simultaneously applied linear mode-hopping and nonlinear squeezing interactions. Under such double coupling, it is found that while the Hamiltonian of the system is clearly Hermitian, the dynamics of the quadrature components of the field operators can be attributed to the non-Hermicity of the system. This manifests through an asymmetric coupling between the quadrature components, which then leads to a variety of remarkable features. In particular, we identify how the emerging exceptional point controls the conversion of thermal states of the modes into single-mode classically or quantum-squeezed states. Furthermore, for reservoirs in squeezed states, we find that the two-photon correlations present in these reservoirs are responsible for unidirectional flow of populations and correlations among the modes and the flow can be controlled by appropriate tuning of the mutual orientation of the squeezed noise ellipses. In the course of analyzing these effects, we find that the flow of the population creates the first-order coherence between the modes which, on the other hand, rules out an enhancement of the two photon correlations responsible for entanglement between the modes. These results suggest new alternatives for the creation of single-mode squeezed fields and the potential applications for the controlled unidirectional transfer of population and correlations in bosonic chains. Full article

Cancer and Alzheimer’s disease (AD) display an inverse relationship, and there is a need to further explore this interplay. One key genetic contributor to AD is SORL1, the loss of which is thought to be causally related to AD development. SORL1 also appears to be implicated in cancer. To examine SORL1 and its network, this article simulated SORL1 and its interactions via signal-flow Boolean modelling, including in silico knockouts (mirroring in vivo loss-of-function mutations). This model (SKM034) predicted a total of 29 key changes in molecular relationships following the loss of SORL1 or another highly connected protein (ERBB2). Literature validation demonstrated that 2 of these predictions were at least partially validated experimentally, whilst 27 were Potentially Novel Predictions (PNPs). Complementing the in-depth relationship analyses was signal flow analysis through the network’s structure, validated using cell line and cancer patient RNA-seq data. Correct prediction rates for these analyses reached 60% (statistically significant relative to a random model). This article demonstrates the clinical relevance of this Alzheimer’s-related network in a cancer context and, through the PNPs, provides a strong starting point for in vitro experimental validation. As with previously published models using similar methods, the model may be reanalysed in different contexts for further discoveries. Full article

Objective: To assess the effectiveness of a fixed contrast injection protocol—75 mL of contrast followed by 40 mL saline at 5 mL/s with an injection duration of 23 s—in achieving diagnostic enhancement in coronary CT angiography (CCTA) using 64-slice detector CT scanner. Materials and Methods: 456 consecutive patients with suspected coronary disease who underwent CCTA on a 64-slice detector CT scanner between January 2023 and December 2024 and were retrospectively enrolled. Each patient received 75 mL of contrast medium followed by 40 mL of saline at a flow rate of 5 mL/s, with a total injection duration of 23 s. Two radiologists, blinded to patient information, independently measured the contrast enhancement (HU) values in the coronary segments, ascending and descending aorta, and left ventricle. Attenuation levels ≥250 HU were considered diagnostic. Patients were grouped by body weight into two categories: Group 1 (≤75 kg) and Group 2 (>75 kg). The independent t-test and Mann–Whitney U test were used to compare HU values in each vessel between the two groups, while the Chi-square test was applied to compare enhancement success rates (HU ≥ 250) between the groups per vessel. Results: A total of 281 patients (mean age: 51.88 years ± 11.15 [SD]; 167 male, 114 female), were included. Statistically significant differences in the HU enhancement measurements were found between groups (p < 0.001–0.007). However, all segments showed mean and median HU values above 250 HU. Enhancement success rates were significantly higher in Group 1 (p = 0.005–0.04), except in the ascending aorta, descending aorta, left main coronary artery, middle right coronary, distal right coronary artery, and middle left circumflex artery, where the rates were statistically comparable between the groups (p = 0.054–0.61). Conclusions: A fixed contrast protocol (75 mL of contrast medium followed by 40 mL of saline at a 5 mL/s flow rate with a total injection duration of 23 s) appears to be feasible for achieving diagnostic contrast enhancement in CCTA using a 64-slice multidetector CT scanner. This protocol may offer a simplified alternative to individualized, weight-based contrast dosing strategies. Full article

Molten salts are widely used in high-temperature energy systems because of their thermal properties. In such applications, natural circulation provides a passive means of heat transport in systems that require passive safety features. Many studies have examined the thermal–hydraulic behavior of molten salts in natural circulation configurations. This work develops a two-dimensional CFD model of a molten salt natural circulation loop and evaluates two formulations—a laminar model and the Transition SST (γ–Reθ) model. The models were verified through mesh-independence studies and validated against experimental benchmark data. Both models reproduced the measured temperature rise across the loop, but significant differences appeared in velocity and Reynolds-number prediction. The laminar model underpredicted circulation by about 30%, whereas the Transition SST model shows 4.2% for velocity and 11.8% for Reynolds number. Local comparison showed that the Transition SST model captured developing wall-peaked structures in the vertical legs, whereas the laminar model misinterprets these regions as stagnant core flow. These findings apply only to the 2D model, and the use of the CFD models follows a benchmark experiment rather than universal validation for all molten salt loops. Overall, the results show that transitional turbulence modeling is needed to capture the mixed-regime behavior in molten salt natural circulation. Full article

Water from mountain regions is a crucial natural resource because of its major economic, social, and environmental significance. Wildfires may disrupt the normal functioning of the hydrological cycle, limiting water resources for nearby areas and degrading water quality in mountainous regions as contaminants enter water systems from the burning of vegetation and soil. In August 2022, the Serra da Estrela mountain, situated in the Mediterranean biogeographical region, was affected by a large wildfire that consumed 270 km² of the Serra da Estrela Natural Park, often resulting in severe vegetation burn, although the soil burn severity was low to moderate in most of the area. The research objective is to assess the impact of this wildfire on the hydrogeochemistry of groundwater and surface water in the Manteigas-Covão da Ametade sector of Serra da Estrela in the context of a wildfire with limited soil burn severity. Groundwater and surface water samples were collected from October 2022 to September 2023 and were analyzed for pH, Total Organic Carbon, electrical conductivity, major ions, potentially toxic elements, iron (Fe), and Polycyclic Aromatic Hydrocarbons. A stormy event in mid-September 2022, occurring before the first sampling campaign, removed most of the ash layer and likely caused transient hydrogeochemical changes in streams. However, the analytical results from the sampled waters revealed that the post-wildfire hydrogeochemical effects are not evident. In fact, the hydrogeochemical changes observed in groundwater and surface water appear to be primarily influenced by the regular hydrological behaviour of aquifers and streams. The low to moderate soil burn severity, the high soil hydrophobicity, and the temporal distribution of precipitation explain why the hydrogeochemistry was primarily influenced by groundwater flow paths, the types and weathering of local lithologies, soil types, dilution effects following wet periods, and seasonal changes in the tributaries feeding into streams, rather than by post-wildfire effects. These outcomes provide valuable insights for water resource management and for developing strategies to mitigate wildfire impacts in mountainous environments. Full article

Background/Objectives: Intracranial arachnoid cysts (Acs) are congenital, usually benign lesions that are frequently regarded as clinically silent in adulthood. Nonetheless, growing evidence indicates that Acs may be associated with subtle but measurable cognitive dysfunction. This systematic review synthesizes neuropsychological and functional neuroimaging findings in adults with intracranial Acs, with a focus on cognitive profiles, functional interactions with the adjacent cortex, and postoperative reversibility. Methods: In accordance with PRISMA 2020 guidelines, MEDLINE/PubMed and Scopus were searched for English-language studies published up to 2023 that reported neuropsychological assessments and/or functional neuroimaging in adult patients with Acs, including single-case reports, case series, and group studies with pre- and post-operative data. Results: Sixty studies met the inclusion criteria. Across anatomical locations, Acs were most consistently associated with impairments in verbal and visual memory and learning, attention, and executive functions, as well as reduced processing or psychomotor speed, whereas language deficits were less consistently observed. Several studies reported postoperative improvement in one or more cognitive domains, suggesting partial reversibility in selected patients. Functional neuroimaging findings revealed altered cortical function in regions adjacent to the cyst, including reduced regional metabolism or cerebral blood flow and task-related activation changes, supporting a functional interaction between Acs and the neighboring cortex. Conclusions: Overall, adults with Acs may exhibit subtle cognitive alterations that vary according to cyst location and appear to be moderated by compensatory mechanisms. These findings underscore the clinical relevance of systematic neuropsychological evaluation and highlight the need for prospective, standardized studies integrating cognitive and neuroimaging outcomes. Full article

Regulatory T cells (Tregs), particularly their phenotypically distinct subpopulations, are critical for the establishment of maternal immune tolerance during embryo implantation. Despite advances in assisted reproductive technologies, implantation failure remains a frequent and often unexplained clinical challenge. Variations in Treg frequency and phenotype have been proposed to influence implantation success, particularly under differing hormonal conditions. This study aimed to investigate peripheral blood Treg levels and their subpopulations on the day of blastocyst transfer in both stimulated in vitro fertilization (IVF/ICSI) cycles involving controlled ovarian hyperstimulation (COH) and true natural cycles with frozen embryo transfer (FET), and to examine their associations with systemic hormone levels and anti-Müllerian hormone (AMH). A prospective observational study was conducted including women undergoing IVF/ICSI with fresh embryo transfer (ET) and women undergoing natural cycle FET. Peripheral blood samples were collected on the day of ET and analyzed using 13-colour flow cytometry, enabling detailed subdivision of Tregs into multiple subpopulations based on the expression of differentiation and chemokine markers, including CXCR5. In addition, because common $\gamma$-chain cytokines may influence pregnancy success by modulating the balance between suppressive Treg and non-Treg subsets, intracellular STAT5 signaling was assessed using phospho-specific flow cytometry. Serum estradiol, progesterone, FSH, LH, and AMH levels were measured in parallel. Significant differences were observed in Treg subpopulation distributions between women who conceived and those who did not. Higher frequencies of naïve CXCR5⁻ Tregs were associated with clinical pregnancy, independent of age, and correlated with serum progesterone levels. Moreover, both naïve Treg frequency and enhanced IL-7-dependent STAT5 signaling in naïve Tregs from women undergoing COH were associated with AMH levels, suggesting a link between ovarian reserve and Treg homeostasis mediated by signal transducer and activator of transcription 5 (STAT5) signaling. In conclusion, Treg subpopulations, particularly CXCR5⁻ naïve Tregs, appear to play a central role in implantation success following ET. Their distribution differs between stimulated and natural cycles and is influenced by systemic progesterone levels and STAT5 signaling. These findings suggest that peripheral Treg profiling may represent a potential biomarker of implantation competence and could inform personalized approaches in assisted reproduction. Full article

Background/Objectives: The Bicêtre score for Vein of Galen Aneurysmal Malformation (VGAM) relies on existing end-organ damage. We hypothesized that transthoracic echocardiography (TTE) could quantify significant systemic steal in clinically stable neonates (Bicêtre score ≥ 12). This study evaluates the Aortic Flow Reversal Ratio (AoFRr) as a tool to measure this steal and predict treatment outcomes. Methods: In a single-center retrospective study of patients with VGAM, the AoFRr (the ratio of the diastolic reversal velocity time integral to the systolic forward volume time integral) was calculated via TTE in the abdominal aorta at the level of the diaphragm before and after endovascular embolization. Over the study period, the cohort underwent a total of 30 endovascular interventions and 49 TTEs. Pre-intervention AoFRr was correlated with the Bicêtre score, and post-intervention changes were analyzed for association with the need for subsequent embolizations. Results: In a cohort of 12 patients with a median Bicêtre score of 18, 83.3% had pre-intervention aortic diastolic flow reversal. The median pre-intervention AoFRr was 0.81, indicating substantial systemic steal despite clinical stability. A post-intervention AoFRr reduction of ≥85% was significantly associated with a lower likelihood of requiring re-intervention (p = 0.0253). Conclusions: The AoFRr quantifies substantial hemodynamic steal in VGAM patients who appear clinically stable by the Bicêtre score. Its reduction following embolization predicts a more favorable clinical course. The AoFRr is a valuable, non-invasive adjunct for risk stratification and may help optimize the timing of endovascular intervention. Full article

In recent years, there has been rapid growth in aesthetic medicine and an increase in the number of minimally invasive procedures aimed at improving appearance. With the increasing number of procedures performed, the incidence of post-operative complications is also rising, and high-frequency ultrasound (HFUS) is increasingly being used to assess these complications. The article presents the case of a 52-year-old woman who reported for an HFUS examination several months after non-surgical nose correction with hyaluronic acid (HA) and implantation of polydioxanone (PDO) lifting threads. The patient experienced post-treatment complications in the form of erythema, oedema and pain, followed by blanching and bruising of the skin. Hyaluronidase and prednisone were used for treatment. Four months after the procedure, the patient returned for another HFUS examination because, despite the disappearance of most symptoms, uneven purple-blue discoloration of the skin on the nose and a subjective feeling of cold persisted. At the time of the HFUS examination, the discoloration was barely visible. The grey-scale HFUS examination revealed foci corresponding to HA deposits and PDO threads located in close proximity to the dorsal artery of the nose. A Doppler examination revealed blood flow disturbances in this artery, which may indicate compression by the threads and be the likely cause of the patient’s complaints. High-frequency ultrasound has proven to be a useful diagnostic method for assessing such complications. Due to its safety, non-invasiveness and high reliability, HFUS has the potential to become a common diagnostic tool in aesthetic medicine practice. Full article

Background/Objectives: The Rho^P23H/WT mouse line is a commonly used model to study rhodopsin P23H-associated autosomal dominant retinitis pigmentosa. Previous studies in Rho^P23H/WT mice have largely focused on retinal changes occurring at one month of age and later, and have indicated a compensatory thickening of inner retinal layers in response to rod degeneration. However, the effect of disease processes during early postnatal retinal development remains understudied. Methods: In this study, we investigated the retinal response to rod dysfunction during early postnatal developmental ages P8–P24 in our novel Rho^P23H/WT reporter line, RhoP23H.GFP, which expresses green fluorescent protein (GFP) exclusively in cone photoreceptors. Results: Histological analysis revealed no significant difference in retinal thickness in RhoP23H.GFP mice compared to healthy controls at the ages investigated. RhoP23H.GFP retinas initially exhibited a greater mislocalization of rhodopsin to the rod cell bodies at P12, though this mislocalization normalized to wildtype by P24. Most notably, flow cytometry revealed significantly increased cone photoreceptor numbers in P12 (61%), P16 (48%), and P24 (40%) RhoP23H.GFP mice compared to wildtype controls, indicating a possible compensatory response of cone photoreceptors to rod dysfunction. Additionally, cone morphology appeared altered in diseased cones. Conclusions: Our results suggest that cones may undergo a developmental compensatory adaptation in response to rod dysfunction, providing new insights into early disease mechanisms of retinitis pigmentosa. Full article

Background: Axillary lymph node (ALN) metastasis is a critical prognostic determinant in breast cancer (BC) that informs surgical management. However, surgically clearing the axilla carries morbidity, so less invasive methods of risk-stratifying patients are needed. ALN fine needle aspiration (FNA) is currently used to detect BC metastases, but these samples also contain immune cells. Methods: Cells obtained via FNA from BC-patient-derived ALNs were analysed using flow cytometry. Results: FNA acquires sufficient leukocytes for comprehensive immunophenotyping of reactive, patient-derived ALNs. All CD4⁺ and CD8⁺ T-cell subsets (naïve, terminal effector, central memory, and effector memory) and rarer (<2%) natural killer (NK) and plasmacytoid dendritic cell (pDC) populations are represented. Importantly, the immune-cell profile of one reactive ALN appears to reflect the immune status of the patient’s axilla. Furthermore, FNA captures immune differences between patients with ≤1 or ≥2 metastatic ALNs. Increased numbers of naïve CD4⁺ T cells, but fewer terminal effector, central memory, and effector memory subpopulations, were obtained from patients with ≥2 metastatic ALNs. Moreover, despite their sparse distribution pattern on whole-section immunohistochemistry (WSI), FNA revealed that CD56⁺ NK cell activation receptors were decreased in patients with ≥2 metastatic ALNs. Finally, FNA captured a decrease in pDCs in patients with ≤1 metastatic ALNs, despite their clustered distribution pattern on WSI. Conclusions: FNA is not only feasible for sampling leukocytes from reactive, patient-derived ALNs, but also identifies immune-cell profiles that reflect axillary tumour burden in BC. Thus, this technique could be used to risk-stratify BC patients in the future. Full article

A two-dimensional ultrasonic anemometer was installed at a height of 20 m on a wind measurement tower in Haiyan Town, Jiangmen, to monitor flow conditions in typhoon Mangkhut (1822) before and after landfall. Mean wind speed, wind direction, turbulence intensity, gust factor, turbulence integral scale, and turbulence power spectral density were derived and analyzed before and after landing. The results show that the central wind speed time history before and after landfall exhibits significant differences, and the mean wind direction undergoes a reverse change of about 180°. The mean downwind and crosswind turbulence intensity before landing were 0.25 and 0.22, respectively, and 0.20 and 0.16 after landing. The associated mean downwind and crosswind gust factors were 1.70 and 0.61 before landing, and 1.55 and 0.46 after. These differences before and after landing are considered significant, and both turbulence intensity and gust factor showed a certain decreasing trend with the increase in wind speed. The relationship between turbulence intensity and gust factor, though somewhat scattered, was basically consistent with the commonly used Ishizaki and Choi empirical formulas. Mean streamwise and crosswind turbulence integral scales before landfall were 218 m and 100 m, respectively, and 198 m and 177 m after. They showed a weak increasing trend with increase in mean wind speed. Power spectra before and after landing were basically consistent. Comparisons with standard forms were inconclusive, though the von Karman spectrum appeared to be slightly superior to the others, particularly as the wind speed and turbulence integral scale increased. Full article