Search Results (398)

Background:Rosmarinus officinalis L. is a medicinally important aromatic plant rich in bioactive secondary metabolites with diverse therapeutic properties. This study aimed to characterize the phytochemical profile of R. officinalis leaf extracts, isolate carnosic acid as a major bioactive diterpene, and evaluate its biological activities. Methods: Leaf extracts were prepared using solvents of increasing polarity and analyzed by phytochemical screening and UHPLC/QTOF-MS. Carnosic acid was isolated by thin-layer chromatography and assessed for antibacterial, antibiofilm, antioxidant, anti-inflammatory, antidiabetic, and antiproliferative activities using in vitro assays. Expression of apoptosis-related genes was also investigated. Results: Methanolic and ethanolic extracts exhibited the highest abundance of phenolic compounds and secondary metabolites, whereas the hexane extract showed lower phytochemical content. UHPLC/QTOF-MS identified seven major metabolites, including phenolic acids, flavonoids, and abietane-type diterpenes. Purified carnosic acid demonstrated potent antibacterial activity (MIC: 10–23 μg/mL) and inhibited biofilm formation by up to 90%. Strong antioxidant activity was observed, with DPPH and ABTS radical-scavenging IC₅₀ values of 125 and 130 μg/mL, respectively. The compound also exhibited notable anti-inflammatory activity and markedly inhibited α-amylase and α-glucosidase activities. Furthermore, carnosic acid exhibited dose-dependent antiproliferative activity against MCF-7, HepG2, and MCF-10A cells, reducing cell viability to 10.8%, 16.9%, and 70.4 ± 1.8%, respectively, at 250 μg/mL, with corresponding IC₅₀ values of 28.3, 37.8, and >250 μg/mL, respectively. Gene expression analysis revealed upregulation of BAX and downregulation of BCL2, indicating activation of mitochondrial-mediated apoptosis. Conclusions:R. officinalis leaves represent a valuable source of multifunctional phytochemicals, particularly carnosic acid. Its broad-spectrum biological activities and apoptosis-inducing potential support its promising application in pharmaceutical, nutraceutical, and biomedical fields. Full article

Silicon anodes hold great promise in high-energy lithium-ion batteries (LIBs) owing to their ultrahigh theoretical specific capacity, appropriate operating voltage, and low costs. However, the drastic volume expansion, inferior electronic conductivity, and unstable solid electrolyte interphase of Si anodes severely restrict their practical application. Herein, a nest-shaped microporous silicon (NMPSi) is rationally designed via acid–base co-etching and then synergistically regulated by surface thin-film carbon coating and ZIF-67-derived hard carbon nanotemplate (NMPSi@THC) by an in situ liquid-phase coating strategy. The constructed unique architecture is capable of buffering the huge volume expansion of inner NMPSi during cycling and constructing an optimized electron/ion transport network, thereby stabilizing the SEI film and preserving the electrode’s structural integrity. When it is evaluated as a LIB anode, the NMPSi@THC exhibits typically improved initial coulombic efficiency (ICE) and outstanding long-life cyclic stability (622.7 mAh g⁻¹ after 300 cycles at 1 A g⁻¹ and 2 mg cm⁻²). Furthermore, the NMPSi@THC//LiFePO₄ full cell delivers an ultrahigh ICE of 94% and a capacity retention rate of 86%, demonstrating its practical application potential. Compared with most recently reported Si anodes, this report delivers better cycling stability and maintains more intact electrode structure under relatively high current density and areal mass loading in half/full cells after long-term cycling. This research offers a convenient and scalable route to fabricate highly stable microporous Si anodes toward high-energy and long-lifespan LIBs. Full article

Sustainable small hydropower (SHP) is central to the clean-energy transition of mountainous Central Asia, yet its long-term reliability depends on a rapidly changing cryosphere. Winter river-ice dynamics—an underappreciated control on run-of-river generation—remain poorly characterized owing to the collapse of in situ hydrometeorological networks since 1991. We use a 112-month Sentinel-1 C-band SAR time series (February 2017–May 2026) over a 5320 km² headwater catchment of the Chu River basin, northern Tien Shan, Kyrgyzstan, to quantify river-ice phenology at 20 m resolution using a per-pixel summer-baseline anomaly approach. Mid-winter (December–February) ice cover declined significantly at −0.51%·yr⁻¹ (p = 0.013; Mann–Kendall p = 0.029), with the 2026 winter recording an unprecedented 2.6–2.8 σ departure from the 2017–2025 climatology. Contrasting the cold 2022 and warm 2026 winters revealed bidirectional climate sensitivity—early breakup versus persistent thin ice—posing distinct SHP hazards. ERA5-Land reanalysis (1992–2026) showed significant winter warming with no precipitation or snowfall trend, indicating thermally forced ice decline. Interpreted within a conceptual Peak Water scenario, this signals a closing window of opportunity for SHP generation, with direct relevance to sustainable water–energy management and the UN Sustainable Development Goals (SDG 7; SDG 13). Our results provide the first decadal, satellite-based evidence of river-ice loss for Central Asian mountain rivers and a transferable monitoring framework to support climate-resilient, sustainable hydropower planning in ungauged basins. Full article

Across much of the Arctic, climate warming has reduced the extent of thicker and more persistent sea ice and increased the prevalence of thinner first-year ice. Thin first-year landfast sea ice is ecologically important because reduced ice thickness can increase light transmission to the ice–water interface, while the associated brine conditions, including salinity and permeability, can strongly influence algal biomass accumulation and photophysiology. This thin (0.24–0.55 m), short-lived, seasonal, first-year landfast sea ice already dominates Nuup Kangerlua fjord, southwest Greenland, making it a useful natural example of ice conditions that may become more common in parts of the future Arctic. We focused on late February–early March because this period captures the seasonal transition from very low winter irradiance toward increasing spring light, when sea ice algal communities begin photosynthetic acclimation prior to the main bloom period. Using this site as an example of future Arctic-like conditions, we investigated chlorophyll a (Chl a) concentration and the photobiology of sea ice algal communities during five sampling events between 2017 and 2022. The vertical distribution of Chl a concentration and photobiological parameters measured with variable chlorophyll fluorescence differed between years, as did Chl a concentrations, with integrated biomass ranging from 0.08 to 0.78 mg Chl a m⁻². Direct under-ice PAR measurements showed transmittance values ranging from 0.013 to 0.29. Bottom-ice communities were acclimated to relatively high light intensities, with E_k often exceeding 200 µmol photons m⁻² s⁻¹, and we detected no clear evidence of photoinhibition in the fluorescence data. Boosted regression tree models identified brine salinity as the main predictor of both Chl a concentration, explaining 42.0% of the variation, and, Φ_{PSII_max}, the maximum dark-adapted photosynthetic efficiency, explaining 86.1% of the variation. Both parameters decreased exponentially with increasing sea ice brine salinity (p < 0.0001), indicating that higher brine salinity was associated with reduced algal biomass and lower photosynthetic efficiency. These results show that short-lived first-year landfast sea ice can support physiologically active sea ice algal communities despite relatively low biomass, and suggest that algal performance in this ice type was more strongly associated with brine salinity during the late-winter to early spring sampling period, while light availability also varied substantially among years. As thin and short-lived sea ice conditions become more common in parts of the Arctic, this habitat may represent an increasingly important, though temporally variable, component of Arctic marine primary production. Full article

High-precision cloud detection is essential for remote sensing applications such as agricultural monitoring and disaster response. However, thin clouds severely limit detection accuracy. The difficulty lies in their semi-transparent nature, which causes their reflected signals to couple with the reflectance of various underlying surfaces. This coupling leads to inconsistent cloud signatures and significant intra-class variability. To address this, we propose a Class Center Residual Attention Network (CCRANet), a radiative transfer theory-inspired framework that employs a class center approach to extract the intrinsic reflective characteristics of thin clouds. Specifically, the core of the network is the Class Center Attention (CCA) module, which extracts invariant intrinsic features of thin clouds, supplemented by the Class Center Residual (CCR) module to eliminate surface-induced interference. Experiments on three public datasets (Landsat-8, CSWV, and CloudS26) show that CCRANet achieves a mean Intersection over Union (mIoU) of 85.93% on the Landsat-8 dataset, outperforming the classic DeeplabV3+ baseline by 10.23 percentage points. In particular, it achieves 22.58 percentage point improvement in thin cloud IoU over DeeplabV3+ in snow/ice scenarios, significantly reducing false positive detections caused by surface spectral similarity. Full article

East Antarctica is composed of a composite Precambrian shield largely covered by a thick ice sheet. Information on the thermal structure of the East Antarctic lithosphere is critical to the understanding of the geological history and ice sheet dynamics of this region. To better describe the lithospheric thermal structure, Curie-point depths are first estimated through the inversion of aeromagnetic anomaly data using the wavenumber-domain centroid method, and the Curie point estimates is further employed to determine a lithospheric thermal thickness model by integrating the 1D steady-state heat conduction equation. Our results show that the variations in both the Curie-point depth and thermal thickness estimates have strong spatial consistency with known major geological provinces, such as ancient cratons and younger orogens. Moreover, our findings show a hot and thin lithosphere in the Gamburtsev Subglacial Mountains and Dronning Maud Land, whereas a cold and thick cratonic lithosphere is found in the Wilkes and Aurora Subglacial Basins and the hinterland of Enderby Land. A few local-scale thermal anomalies are also observed in cratonic areas, indicating that some of these areas have lost their cratonic signature. The new thermal thickness model provides direct constraints that can be used to trace early tectonic–thermal activities in East Antarctica. Full article

The “New Arctic” regime represents a prominent climatic feature of the Arctic Ocean under global warming, characterized by persistently low summer sea ice extent, a marked reduction in sea ice thickness, and an expansion of open water areas at high latitudes. As a key indicator of the Arctic sea ice system, the spatiotemporal evolution of sea ice thickness and its underlying driving mechanisms remain incompletely understood. Using reanalysis datasets and remote sensing observations, this study identifies major abrupt shifts in Arctic sea ice thickness under the New Arctic regime, reveals the spatiotemporal distribution characteristics of winter sea ice thickness, and examines the driving factors from both thermodynamic and dynamic perspectives. The results show that the evolution of Arctic sea ice thickness can be divided into three phases: a high-level period during the “Traditional Arctic” (1979–1992), a rapid thinning period during the New Arctic transition (1993–2012), and a low-level stabilization period in the New Arctic regime (2013–2023). The first EOF mode of winter sea ice thickness depicts a spatially consistent thinning pattern across the entire Arctic, with the most significant reduction occurring in the multi-year ice regions north of the Canadian Arctic Archipelago and Greenland. The second EOF mode exhibits an out-of-phase variation between the Atlantic and Pacific sectors of the Arctic, accompanied by a shrinking amplitude and weakened regional oscillations. The coupling between surface air temperature and sea ice thickness displays distinct phase dependence: their negative correlation is strongest during the transition period (r = −0.78, p < 0.001) but becomes statistically insignificant in the New Arctic regime. Sea ice motion speed exhibits an overall accelerating trend, which extends from the marginal seasonal ice zones toward the high-latitude multi-year ice regions, accompanied by a notably enhanced sensitivity of sea ice motion to wind forcing. Sea ice volume flux through the Fram Strait is primarily controlled by ice motion speed, whose contribution to the flux is approximately 2.6 times that of ice thickness. The recovery of ice drift speed offsets the thinning of sea ice cover, leading to a partial rebound in volume flux during the New Arctic steady state. This study identifies the evolutionary patterns and drivers of Arctic sea ice thickness under the New Arctic regime, providing a scientific basis for further understanding the changes in the Arctic climate system and associated air–sea ice interactions. Full article

Nares Strait is a narrow channel situated between Ellesmere Island and Greenland, through which the prevailing winds and surface current transport multiyear ice southward from the Arctic Ocean. Seasonal formation of ice arches at the northern or southern terminus of Nares Strait reduces the annual loss of multiyear ice. Since 2007, there have been six atypical ice arch configurations and two seasons in which no ice arches formed. The duration of ice arch days in Nares Strait is trending downward, accelerating multiyear ice loss. Understanding the physical processes of ice arch formation is critical for predicting the future of ice transport in Nares Strait. On 28 and 29 March 2023, satellite imagery showed anomalously limited floe movement throughout Nares Strait. When normal ice flow resumed, a southern ice arch had formed. The data suggests that southerly winds close to neap tide negated the southward movement of ice, causing immobilization of ice in Kane Basin on a scale previously assumed impossible, which led to ice arch formation. The results indicate that winds counteracting southerly ice movement is a mechanism of ice arch formation. This study presents a previously undocumented mechanism of ice formation, one that will increase in importance as Arctic ice thins and becomes more mobile. Full article

Resonant electromechanical de-icing uses piezoelectric actuators to generate stresses high enough to fracture and shed ice, offering an energy-efficient alternative to conventional systems. This work focuses on prestressed piezoelectric actuators composed of a ceramic stack clamped between two brackets, addressing limitations of previous designs such as mechanical losses and screw fatigue. A new architecture is proposed, featuring a variable-cross-section screw that concentrates deformation in a thinned central region and brackets bonded to the structure to reduce losses. An analytical sizing method is developed using multi-beam longitudinal vibration modelling and two de-icing criteria, including a newly introduced one. The analysis shows how actuator geometry and modal shapes influence de-icing performance, required voltage, and mechanical stresses, highlighting key trade-offs. A dedicated prototype is designed and experimentally tested, with results in good agreement with the analytical predictions. Full article

Background/Objectives: Triptolide (TP), a potent natural diterpenoid, exhibits anti-glioma activity, but faces significant clinical translation challenges, including poor water solubility, systemic toxicity such as hepatotoxicity, and inadequate tumor targeting. This study aimed to develop a novel epidermal growth factor receptor (EGFR)-targeted liposomal formula-tion, designated as TP-CTX-Lip (where CTX denotes cetuximab), to enhance the deliv-ery efficiency and therapeutic window of TP. Methods: The formulation was optimized using a uniform design approach (four factors, six levels) and prepared via thin-film hydra-tion–ultrasonication. The encapsulation of TP was supported by Fourier transform in-frared spectroscopy (FTIR) and thermal analysis (DSC/TGA), which revealed molecu-lar interactions (e.g., hydrogen bonding) with lipid components and a marked en-hancement in thermal stability, consistent with successful incorporation into the lipo-somal bilayer. The physicochemical properties, including the size, polydispersity index (PDI), zeta potential, encapsulation efficiency, and drug loading, were characterized. In vitro release kinetics were evaluated in phosphate buffer (pH 7.4), and cytotoxicity was assessed in high-EGFR (U87-MG) and low-EGFR (SW1088) glioma cells. In vivo efficacy and developmental toxicity were investigated using zebrafish models. The op-timized TP-CTX-Lip demonstrated favorable characteristics: size = 131.3 ± 4.5 nm, PDI = 0.24 ± 0.006, zeta potential = −23.37 ± 0.27 mV, encapsulation efficiency = 85.83% ± 1.81%, and drug loading = 13%. In vitro release followed first-order kinetics dominated by Higuchi diffusion (79.0% ± 4% at 24 h). After 48 h of treatment, TP-CTX-Lip exhib-ited significantly enhanced cytotoxicity in U87-MG cells (IC50 = 10.4 ± 0.2 nM), com-pared with IC50 values of 42.8 nM in SW1088 cells and 45.3 nM for non-targeted lipo-somes. In the 3T3-L1 non-cancerous cell line, the 48 h IC50 value of TP-CTX-Lip (8.433 ± 0.954µM) was higher than that of the TP solution (2.173 ± 0.181µM) but lower than that of TP-Lip (25.78 ± 2.691µM). Specifically, in 3T3-L1 cells, the 48 h IC50 of TP-CTX-Lip (8.43 µM) was approximately 4-fold higher than that of free TP (2.17 µM), confirming its substantially reduced cytotoxicity against non-cancerous cells. Results: In comparison to TP-Lip and free FITC solution, the uptake rate of TP-CTX-Lip in U87-MG cells exhibited a significantly higher level. Specifically, the uptake rate for the TP-CTX-Lip group (57.46 ± 5.44%) was statistically significantly higher than that of TP-Lip (13.7 ± 2.33%) and the free FITC solution group (20.97 ± 1.60%) (p < 0.01). In zebrafish, TP-CTX-Lip reduced developmental toxicity, with LC50 increased 1.26 times to 5.733 μg/mL, and suppressed orthotopic U87-MG xenograft growth (p < 0.001), in-dicating an improved therapeutic window as reflected by the LC50/IC50 ratio. Conclusions: the EGFR-targeted TP-CTX-Lip significantly enhances the tumor selectivity and safety of TP, providing a promising strategy for targeted glioma therapy. Full article

River ice products from optical satellites are still dominated by binary ice–water or ice–snow discrimination, leaving within-ice spectral heterogeneity largely unresolved. This study benchmarks how far river ice can be subclassified from multispectral reflectance alone on the Tibetan Plateau using Landsat 5/7, Landsat 8/9, and Sentinel-2 surface-reflectance imagery. We compiled 356 winter scenes acquired between 2000 and 2024 across eight Tibetan Plateau basins, delineated river ice using NDSI and RDRI, and extracted 24,674 pixel-level spectra. To define reproducible subclasses, we applied K-means clustering guided by the Silhouette Coefficient, Davies–Bouldin index, Calinski–Harabasz index, and Gap Statistic. Combined with stratified visual interpretation, this approach consistently supported four optical spectral subclasses: thin-snow-covered ice, thick ice cover, thin ice, and frazil ice. Within-sensor classification accuracy remained extremely high (overall accuracy ≥ 0.948; kappa ≥ 0.929), with the Backpropagation Neural Network (BPNN) and tree ensembles performing best. Crucially, evaluating the optimal BPNN architecture revealed exceptional multi-dimensional generalizability: a Leave-One-Basin-Out spatial cross-validation yielded a stable average OA > 99% with an average Kappa > 0.98, while a unified multi-sensor model achieved a robust OA of 90.14% and a Kappa of 0.86. The most stable discriminative cues were visible-band brightness, reflectance turnover near ~0.7 μm, and shortwave-infrared sensitivity to effective thickness and surface wetness. These results provide a sensor-aware benchmark for practical optical river ice spectral subclassification and clarify which multispectral bands most strongly constrain subclass separability. Full article

A study was conducted on the interaction of surface gravity waves with a relatively thin, free-floating ice floe compared to the height of the waves. Physical and numerical modeling, as well as analytical research, were used. An overview of scientific works on the research topic is presented. The physical model consisted of an experimental setup (wave flume) with a wooden plate exposed to gravitational harmonic waves of different lengths and periods. The numerical model is based on calculations performed in the LS-DYNA program, where the fluid was simulated using the Euler–Lagrange method, and solid bodies were considered rigid. Analytical studies use the theory of interaction of small-amplitude waves with floating breakwaters. It is shown that as the wave height increases for conditions of interaction between waves and ice floes of almost identical horizontal dimensions, one end of the floating body sinks into the water, which leads to a significant reduction in the drift speed of the ice floe. Formulas have been obtained that express the ratio of the ice floe’s speed to the wave velocity, as well as the ratio of the height of the incident waves to the height of the transmitted waves, depending on the ratio of the wavelength to the horizontal dimensions of the floating ice floe. Full article

Since the features of cross-seeding of alpha-synuclein forms may affect the sensitivity and specificity of the test systems, we developed a modified approach to obtain alpha-synuclein amyloid seeds with particle sizes from 20 to 50 nm prepared from either the wild-type protein (α-synWT) or its more fibrillation-prone form A53T (α-synA53T). These seeds had optimal properties for subsequent initiation of fibrillation. Our data showed that the elevated efficiency of alpha-synuclein A53T monomer transformation was hardly affected by the type of used seeds, whereas the addition of the seeds obtained from the alpha-synuclein mutant form to wild-type protein monomers had a significantly smaller effect than α-synWT seeds. Transmission electron microscopy data revealed that in the presence of α-synWT seeds the wild-type alpha-synuclein formed long and wide fibrils, while the addition of α-synA53T seeds led to the formation of long, but thin fibrils. Since the lag period of α-synA53T monomer fibrillation was significantly reduced compared to the wild-type protein, the replacing of α-synWT with α-synA53T in current assay systems designed to detect aberrant forms of α-synuclein in biological fluid samples (e.g., RT-QuIC) could substantially cut the time of analysis. In the future, a set of alpha-synuclein mutant forms could be used for the differential diagnosis of synucleinopathies caused by the different mutations of this protein. Full article

Phyllanthus emblica (amla) exhibits anticancer activity, but its extracts often suffer from poor stability and bioavailability. This study developed amla extract-loaded niosomes to enhance delivery and evaluate their anticancer activity against MCF-7 and HCT116 cell lines, supported by in silico analyses. Methodology: Amla extract was prepared using a 50% aqueous–alcoholic solvent system and lyophilized. Niosomes were prepared by the thin-film hydration method and characterized for physicochemical properties. Anticancer activity was evaluated through in vitro cytotoxicity studies, supported by molecular docking and in silico pharmacokinetic analyses. Results: Optimized niosomes exhibited spherical morphology, good homogeneity (PDI < 0.30), anionic surface charge, high entrapment efficiency (70.5 ± 5.9%), and sustained diffusion-controlled release. In vitro cytotoxicity demonstrated a strong concentration-dependent anticancer activity of amla-loaded niosomes across a range of concentrations (31.25–1000 µg/mL) against both MCF-7 and HCT116 cell lines. At 1000 µg/mL, cell viability decreased to 7.0% and 5.4% in MCF-7 and HCT116 cells, respectively, with calculated IC₅₀ values of 245 µg/mL and 158 µg/mL. Molecular docking and pharmacokinetic predictions supported the potential multi-target anticancer relevance of major phytochemicals, including hydrolyzable tannins, phenolic acids, flavonoid aglycones and glycosides, and highlighted bioavailability limitations for certain high-affinity glycosylated flavonoids, reinforcing the rationale for vesicular encapsulation. Conclusions: Amla extract-loaded niosomes represent a promising vesicular system for enhanced, sustained delivery of anticancer activity in vitro, with complementary in silico findings supporting mechanistic plausibility and translational rationale. Further studies are warranted to evaluate their performance in vivo. Full article

Wind and solar power generation represent crucial forms of clean energy utilisation, where generation efficiency is paramount. However, clean energy facilities such as wind turbine blades and photovoltaic sheets frequently cease operation during low temperatures due to ice and frost accumulation, resulting in energy wastage. This study investigates the mechanism of low-temperature surface frost formation through observational experiments. By comparing the temporal progression of frost accumulation on four materials—HIPS (high-impact polystyrene), ABS (Acrylonitrile Butadiene Styrene), acrylic, and acrylic sheet with low-temperature flexible superhydrophobic coating (LFSC)—it validates the anti-frost capabilities of superhydrophobic surfaces. The experimental results show that, under the same conditions, surface frosting gradually decreases as the contact angle of the material increases. After 15 min of frosting, the frost layer thicknesses of the four materials were 0.057 mm, 0.101 mm, 0.105 mm, and 0.275 mm, respectively, and the frost coverage per unit area was 12%, 68%, 76%, and 88%, respectively. The frost formed on the superhydrophobic coating surface was loose and thin, with a frost suppression efficiency exceeding 80%. In contrast, the three materials—HIPS, ABS, and untreated acrylic sheets—exhibited significant frost particle accumulation, and as time progressed, a cycle of frost crystal growth, melting, and regrowth occurred. This study demonstrates that superhydrophobic surfaces possess excellent frost-inhibiting capabilities, which can reduce the energy consumption associated with traditional defrosting methods such as heating and spraying chemical de-icing agents, thereby enabling the sustainable use of energy. Full article