Search Results (761)

Background/Objectives: The aim of this research is to analyze the effect of paclitaxel on endoplasmic reticulum (ER) stress in spermatogenic cells. Methods: In the study, spermatogonium (GC1) and spermatocyte (GC2) cell lines were used. The IC50 dose of paclitaxel was calculated using an MTT assay. Each cell line was separated into two different groups: control (GC1-C, GC2-C) and paclitaxel-treated (GC1-P, GC2-P). The control cells were incubated under standard culture conditions. The paclitaxel group cells were incubated in culture medium containing the paclitaxel IC50 dose for 24 h. After the experiments, all groups were stained with GRP78, p-PERK, and p-eIF2α antibodies using semi-quantitative immunocytochemistry. Results: Paclitaxel showed cytotoxicity. In the experimental model of the paclitaxel-treated cells, all the markers showed elevated levels of immunoreactivity, indicating ER stress. Conclusions: Paclitaxel administration triggered ER stress in spermatogenic cells. Studies of ER-related stress mechanisms in spermatogenic cells with further advanced molecular analyses will be important for therapeutic strategies. Full article

This study introduces a novel methodology for assessing ice-jam flood hazards along river channels. It employs empirical equations that relate non-dimensional ice-jam stage to discharge, enabling the generation of an ensemble of longitudinal profiles of ice-jam backwater levels through Monte-Carlo simulations. These simulations produce non-exceedance probability profiles, which indicate the likelihood of various flood levels occurring due to ice jams. The flood levels associated with specific return periods were validated using historical gauge records. The empirical equations require input parameters such as channel width, slope, and thalweg elevation, which were obtained from bathymetric surveys. This approach is applied to assess ice-jam flood hazards by extrapolating data from a gauged reach at Fort Simpson to an ungauged reach at Jean Marie River along the Mackenzie River in Canada’s Northwest Territories. The analysis further suggests that climate change is likely to increase the severity of ice-jam flood hazards in both reaches by the end of the century. This methodology is applicable to other cold-region rivers in Canada and northern Europe, provided similar fluvial geomorphological and hydro-meteorological data are available, making it a valuable tool for ice-jam flood risk assessment in other ungauged areas. Full article

Background: Short-chain fatty acids (SCFAs), microbial metabolites also known as postbiotics, are essential for maintaining gut health. However, their antiproliferative effects on gastric cancer cells and potential interactions with conventional therapies remain underexplored. This study aimed to investigate the effects of three SCFA salts—magnesium acetate (A), sodium propionate (P), and sodium butyrate (B)—individually and in combination (APB), as well as in combination with dexamethasone (Dex), on AGS gastric adenocarcinoma cells. Methods: AGS cells were treated with PB, AP, AB, APB, Dex, and APB+Dex. Cell viability was assessed to determine antiproliferative effects, and the IC₅₀ of APB was calculated. Flow cytometry was used to evaluate apoptosis and necrosis. Reactive oxygen species (ROS) levels were measured to assess oxidative stress. Proteomic analysis via LC-MS was performed to identify differential protein expression and related pathways impacted by the treatments. Results: SCFA salts showed significant antiproliferative effects on AGS cells, with APB exhibiting a combined IC₅₀ of 568.33 μg/mL. The APB+Dex combination demonstrated strong synergy (combination index = 0.76) and significantly enhanced growth inhibition. Both APB and APB+Dex induced substantial apoptosis (p < 0.0001) with minimal necrosis. APB alone significantly increased ROS levels (p < 0.0001), while Dex moderated this effect in the combination group APB+Dex (p < 0.0001). Notably, the APB+Dex treatment synergistically targeted multiple tumour-promoting mechanisms, including the impairment of redox homeostasis through SLC7A11 suppression, and inhibition of the haemostasis, platelet activation network and NF-κB signalling pathway via downregulation of NFKB1 (−1.34), exemplified by increased expression of SERPINE1 (1.99) within the “Response to elevated platelet cytosolic Ca²⁺” pathway. Conclusions: These findings showed a multifaceted anticancer mechanism by APB+Dex that may collectively impair cell proliferation, survival signalling, immune modulation, and tumour microenvironment support in gastric cancer. Full article

Topographic slope is a key parameter for characterizing landscape geomorphology. The Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) offers high-resolution along-track slopes based on the ground profiles generated by dense signal photons. However, the across-track slopes are typically derived using the ground photon geolocations from the weak-beam and strong-beam pair, limiting the retrieval accuracy and losing valid results over rugged terrains. The goal of this study is to propose a new method to derive the across-track slope merely using single-track photon data of a strong beam based on the theoretical formula of the received signal pulse width. Based on the ICESat-2 photon data over the Walker Lake area, the specific purposes are to (1) extract the along-track slope and surface roughness from the signal photon data on the ground; (2) generate an elevation frequency histogram (EFH) and calculate its root mean square (RMS) width; and (3) derive the across-track slope from the RMS width of the EFH and evaluate the retrieval accuracy against the across-track slope from the ICESat-2 product and plane fitting method. The results show that the mean absolute error (MAE) obtained by our method is 11.45°, which is comparable to the ICESat-2 method (11.61°) and the plane fitting method (12.51°). Our method produces the least invalid data proportion of ~2.5%, significantly outperforming both the plane fitting method (10.29%) and the ICESat-2 method (32.32%). Specifically, when the reference across-track slope exceeds 30°, our method can consistently yield the optimal across-track slopes, where the absolute median, inter quartile range, and whisker range of the across-track slope residuals have reductions greater than 4.44°, 1.31°, and 0.10°, respectively. Overall, our method is well-suited for the across-track slope estimation over rugged terrains and can provide higher-precision, higher-resolution, and more valid across-track slopes. Full article

Amidst the intensification of global climate change and the increasing impacts of human activities, ecosystem patterns and processes have undergone substantial transformations. The distribution and evolutionary dynamics of mountain ecosystems have become a focal point in ecological research. The Surkhan River Basin is located in the transitional zone between the arid inland regions of Central Asia and the mountain systems, where its unique physical and geographical conditions have shaped distinct patterns of vertical zonation. Utilizing Landsat imagery, this study applies a hierarchical classification approach to derive land cover classifications within the Surkhan River Basin. By integrating the NDVI (normalized difference vegetation index) and DEM (digital elevation model (30 m SRTM)), an “NDVI-DEM-Land Cover” scatterplot is constructed to analyze zonation characteristics from 1980 to 2020. The 2020 results indicate that the elevation boundary between the temperate desert and mountain grassland zones is 1100 m, while the boundary between the alpine cushion vegetation zone and the ice/snow zone is 3770 m. Furthermore, leveraging DEM and LST (land surface temperature) data, a potential energy analysis model is employed to quantify potential energy differentials between adjacent zones, enabling the identification of ecological transition areas. The potential energy analysis further refines the transition zone characteristics, indicating that the transition zone between the temperate desert and mountain grassland zones spans 1078–1139 m with a boundary at 1110 m, while the transition between the alpine cushion vegetation and ice/snow zones spans 3729–3824 m with a boundary at 3768 m. Cross-validation with scatterplot results confirms that the scatterplot analysis effectively delineates stable zonation boundaries with strong spatiotemporal consistency. Moreover, the potential energy analysis offers deeper insights into ecological transition zones, providing refined boundary identification. The integration of these two approaches addresses the dimensional limitations of traditional vertical zonation studies, offering a transferable methodological framework for mountain ecosystem research. Full article

Background and Objectives: This study aimed to investigate the anticancer effects and potential synergistic interactions of quercetin (Q) and doxorubicin (Dox) on the MG-63 osteosarcoma (OS) cell line. Specifically, the effects of these agents on cell viability, apoptosis, reactive oxygen species (ROS) generation, antioxidant defense, and the phosphoinositide 3-kinase/protein kinase B (PI3K/Akt1) signaling pathway were evaluated. Material and Methods: MG-63 cells were cultured and treated with varying concentrations of Q and Dox, both individually and in combination (fixed 5:1 molar ratio), for 48 h. Cell viability was assessed using an MTT assay, and IC₅₀ values were calculated. Synergistic effects were analyzed using the Chou–Talalay combination index (CI). Apoptosis was evaluated via Annexin V-FITC/PI staining and caspase-3/7 activity. ROS levels were quantified using DCFH-DA probe, and antioxidant enzymes (SOD, GPx) were measured spectrophotometrically. Gene expression (Runx2, PI3K, Akt1, caspase-3) was analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Results: Q and Dox reduced cell viability in a dose-dependent manner, with IC₅₀ values of 70.3 µM and 1.14 µM, respectively. The combination treatment exhibited synergistic cytotoxicity (CI < 1), especially in the Q50 + Dox5 group (CI = 0.23). Apoptosis was significantly enhanced in the combination group, evidenced by increased Annexin V positivity and caspase-3 activation. ROS levels were markedly elevated, while antioxidant enzyme activities declined. RT-qPCR revealed upregulation of caspase-3 and downregulation of Runx2, PI3K, and Akt1 mRNA levels. Conclusions: The combination of Q and Dox exerts synergistic anticancer effects in MG-63 OS cells by inducing apoptosis, elevating oxidative stress, suppressing antioxidant defense, and inhibiting the PI3K/Akt1 signaling pathway and Runx2 expression. These findings support the potential utility of Q as an adjuvant to enhance Dox efficacy in OS treatment. Full article

Head and neck cancer (HNC) is a highly aggressive malignancy with limited treatment options and poor prognosis. Inflammation plays a critical role in HNC progression, with elevated levels of pro-inflammatory cytokines such as TNF, IL-6, IL-8, and IL-1β contributing to tumor development. In this study, a novel series of boronic chalcones was designed and synthesized as potential dual-action anticancer and anti-inflammatory agents. The most potent compounds were evaluated for their cytotoxicity against Squamous Cell Carcinoma (SCC-25), and their selectivity index (SI) was determined. Compound 5 emerged as the most promising, displaying cytotoxicity against cancer cells, with IC₅₀ values of 17.9 µM and a favorable SI (>3). Mechanistic studies revealed that its anticancer activity was independent of p53 status, and annexin V/PI staining indicated cell death via necrosis. Interestingly, compound 5 also significantly reduced pro-inflammatory cytokine levels, as TNF and IL-6. Furthermore, drug metabolism and pharmacokinetics (DMPK) studies demonstrated that compound 5 exhibited moderate solubility and high permeability. These findings underscore the crucial role of the boronic acid moiety in enhancing both anticancer and anti-inflammatory properties. Full article

This study examines a Mei-Yu rainfall event using rain gauges (RG) and OTT Parsivel disdrometers to observe precipitation characteristics and raindrop size distributions (RSD), with comparisons made against Weather Research and Forecasting (WRF) model simulations. Results show that Parsivel-derived rain rates (RR) are slightly underestimated relative to RG measurements. Both observations and simulations identify 1–3 mm raindrops as the dominant precipitation contributors, though the model overestimates small and large drop contributions. At low RR, decreased small-drop and increased large-drop concentrations cause corresponding leftward and rightward RSD shifts with decreasing altitude—a pattern well captured by simulations. However, at elevated rainfall rates, the simulated concentration of large raindrops shows no significant increase, resulting in negligible rightward shifting of RSD in the model outputs. Autoconversion from cloud droplets to raindrops (ATcr), collision and breakup between raindrops (AGrr), ice melting (MLir), and evaporation of raindrops (VDrv) contribute more to the number density of raindrops. At 0.1 < RR < 1 mm·h⁻¹, ATcr dominates, while VDrv peaks in this intensity range before decreasing. At higher intensities (RR > 20 mm·h⁻¹), AGrr contributes most, followed by MLir. When the RR is high enough, the breakup of raindrops plays a more important role than collision, leading to a decrease in the number density of raindrops. The overestimation of raindrop breakup from the numerical parameterization may be one of the reasons why the RSD does not shift significantly to the right toward the surface under the heavy RR grade. The RSD near the surface varies with the RR and characterizes surface precipitation well. Toward the surface, ATcr and VDrv, but not AGrr, become similar when precipitation approaches. Full article

It is evident that a novel engineering solution is required in order to elevate a greater number of polluting cars into a higher category. There appears to be a paucity of direct interest in upgrading Euro 1, 2, 3, 4, and 5 vehicles to the highest possible level, primarily through software modifications of the parameters determining the performance of the internal combustion engine (ICE). The potential for advancement in this area is evidenced by the presence of systems that enhance environmental efficiency, even in Euro 2 vehicles. These include exhaust gas recirculation, catalytic converter, lambda sensor, electronic control fuel injection, and ignition timing. It is precisely these vehicles that are subject to optimization, a process which would allow the maximum service life of otherwise more reliable but older vehicles to be exploited. Full article

Hallux valgus (HV) is described as a lateral deviation of the great toe at the first metatarsophalangeal joint (MTP), which is a very common foot deformity in the clinic. This deformity extends beyond localized foot mechanics to affect the entire lower extremity kinetic chain, potentially increasing dynamic instability during locomotion. This study aimed to characterize the kinematics of ankle and knee joints during walking in HV patients compared to controls. In total, 23 patients with bilateral HV and matched healthy controls were recruited. The 6-DOF kinematics data of ankles and knees were collected using a joint motion function analysis system while level walking at adaptive speed. HV patients demonstrated significant kinematic alterations in the ankle joint at IC, including decreased varus by 2.87° (p < 0.001), decreased internal rotation by 1.77° (p = 0.035), and decreased plantarflexion by 4.39° (p < 0.001) compared with healthy subjects. Concurrent compensatory changes in the knee joint included increased varus rotation by 1.41° (p = 0.023), reduced anterior translation by 0.84 mm (p < 0.001), and increased lateral translation by 0.26 mm (p = 0.036). HV patients showed increased ankle dorsiflexion of 3.61° (p = 0.06) and decreased ankle internal rotation of 2.69° (p = 0.043), with concurrent increased knee internal rotation of 2.59° (p = 0.009) at SPF. The ripple effect during walking in the HV population may elevate the risk of knee pathologies. These findings may inform both conservative management strategies and post-surgical rehabilitation regimens. Full article

Glacier classification offers a structured framework for assessing glacier characteristics and understanding their responses to climate change. In this study, we apply the Shi–Xie glacier classification system, proposed by Chinese glaciologists Shi and Xie, to evaluate the transformation of extremely continental, subcontinental, and maritime glaciers across China over the past four decades. Our results show a widespread rise in equilibrium line altitudes (ELAs), alongside complex changes in climatic and glaciological parameters. Notably, despite ongoing warming trends, nearly half of the glaciers experienced cooling at the ELA, and over two-thirds showed a decline in summer mean temperatures. This apparent contradiction is explained by elevation-induced cooling; as ELAs rise to higher altitudes, the corresponding summer air temperatures decline due to the lapse rate effect. Near-surface ice temperatures (20 m depth) were strongly consistent with changes in annual air temperature. Precipitation trends were spatially heterogeneous, yet around 70% of glaciers experienced stable or slightly increasing annual precipitation. In contrast, maritime glaciers, particularly those in the southeastern glacierized regions, exhibited marked decreases. Glacier surface velocities generally declined, with 90% of glaciers flowing at speeds below 50 m a⁻¹. Threshold-based analysis reveals that glaciers in transitional zones frequently exhibit multi-indicator deviations. Extremely continental glaciers near classification boundaries showed a shift toward warmer, wetter subcontinental conditions, while maritime glaciers tended toward drier, colder subcontinental characteristics. These findings offer new insights into the differentiated responses and ongoing transformation of glacier types in China under climate change. Full article

The thermal conductivity of steel is high compared to other materials such as concrete or timber. Therefore, fire protection measures are applied to prolong the duration between the onset of fire exposure and the final loss of load-bearing function of a steel structure. The most common passive fire protection measure is the application of intumescent coating (IC), a thin film that expands at elevated temperatures and forms an insulating char layer of lower thermal conductivity. This paper focuses on structural steel beams with IPE open-section profiles protected by a water-based IC and subjected to static and standard fire loading. ANSYS 16.0 is used to simulate heat transfer, with thermal conductivity function described by standard multivariate linear regression analysis, followed by mechanical analysis considering degradation of material mechanical properties at elevated temperatures. Simulations are conducted for all IPE profile sizes, with varying initial degrees of utilisation, beam lengths, and coating thicknesses. Results indicated fire resistance times ranging from 24 to 53.5 min, demonstrating a relatively good level of fire resistance even with the minimal IC thickness. Furthermore, artificial neural networks were developed to predict the fire resistance time of steel members with IC using varying numbers of hidden neurons and subset ratios. The model achieved a predictability level of 99.9% upon evaluation. Full article

Ice wedges, which are ubiquitous in permafrost areas, play a significant role in the evolution of permafrost landscapes, influencing the topography and hydrology of these regions. In this paper, we combine a detailed multi-generational, interdisciplinary, and international literature review along with our own field experiences to explore the development of low-centered ice-wedge polygons and their orthogonal networks. Low-centered polygons, a type of ice-wedge polygonal ground characterized by elevated rims and lowered wet central basins, are critical indicators of permafrost conditions. The formation of these features has been subject to numerous inconsistencies and debates since their initial description in the 1800s. The development of elevated rims is attributed to different processes, such as soil bulging due to ice-wedge growth, differential frost heave, and the accumulation of vegetation and peat. The transition of low-centered polygons to flat-centered, driven by processes like peat accumulation, aggradational ice formation, and frost heave in polygon centers, has been generally overlooked. Low-centered polygons occur in deltas, on floodplains, and in drained-lake basins. There, they are often arranged in orthogonal networks that comprise a complex system. The prevailing explanation of their formation does not match with several field studies that practically remain unnoticed or ignored. By analyzing controversial subjects, such as the degradational or aggradational nature of low-centered polygons and the formation of orthogonal ice-wedge networks, this paper aims to clarify misconceptions and present a cohesive overview of lowland terrain ice-wedge dynamics. The findings emphasize the critical role of ice wedges in shaping Arctic permafrost landscapes and their vulnerability to ongoing climatic and landscape changes. Full article

Background: Myofascial trigger points (MTrPs) are hyperirritable spots within taut bands of skeletal muscle fibers, often developing in overloaded muscles. Ischemic compression (IC) is a frequently used therapeutic technique for MTrP treatment. Material and Methods: Seventy-nine participants with MTrPs in the upper trapezius muscle were included. Three IC protocols were used. In group 1, the compression force was increased once; in group 2, twice; and in group 3, three times—each time up to the pain threshold, then held constant until the pain subsided. Evaluations included pressure pain threshold (PPT), pressure pain perception (PPP), and myotonometric measurements. Results: PPT values increased significantly in group 2 (p = 0.009) and group 3 (p = 0.009), while PPP values decreased significantly in both groups (group 2: p = 0.016; group 3: p = 0.041) post-intervention. Group 1 showed a significant reduction in muscle tone (p < 0.001), and group 2 in muscle stiffness (p = 0.036). Muscle elasticity significantly improved in all groups: group 1 (p = 0.022), group 2 (p = 0.001), and group 3 (p = 0.042). Conclusions: IC applied with a constant force at the individual’s pain perception threshold effectively elevates the pain threshold and enhances the biomechanical parameters of muscle fibers in the trigger point area. Full article

The Advanced Topographic Laser Altimeter System (ATLAS) on the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) employs a photon-counting detection mode with a 532 nm laser to obtain high-precision Earth surface elevation data and offers a new remote sensing method for nearshore bathymetry. The key issues in using ATLAS ATL03 data for bathymetry are achieving automatic and accurate extraction of signal photons in different water environments. Especially for areas with sharply fluctuating topography, the interaction of various impacts, such as topographic fluctuations, sea waves, and laser pulse direction, can result in a sharp change in photon density and distribution at the seafloor, which can cause the signal photon detection at the seafloor to be misinterpreted or omitted during analysis. Therefore, an improved size and direction adaptive filtering (ISDAF) method was proposed for nearshore bathymetry using ATLAS ATL03 data. This method can accurately distinguish between the original photons located above the sea surface, on the sea surface, and the seafloor. The size and direction of the elliptical density filter kernel automatically adapt to the sharp fluctuations in topography and changes in water depth, ensuring precise extraction of signal photons from both the sea surface and the seafloor. To evaluate the precision and reliability of the ISDAF, ATLAS ATL03 data from different water environments and seafloor terrains were used to perform bathymetric experiments. Airborne LiDAR bathymetry (ALB) data were also used to validate the bathymetric accuracy and reliability. The experimental findings show that the ISDAF consistently exhibits effectiveness in detecting and retrieving signal photons, regardless of whether the seafloor terrain is stable or dynamic. After applying refraction correction, the high accuracy of bathymetry was evidenced by a strong coefficient of determination (R²) and a low root mean square error (RMSE) between the ICESat-2 bathymetry data and ALB data. This research offers a promising approach to advancing remote sensing technologies for precise nearshore bathymetric mapping, with implications for coastal monitoring, marine ecology, and resource management. Full article