Search Results (165)

Accurate identification of clear-air echoes is crucial for reliable cloud boundary detection using ground-based radar. The clear-air echo classification method in the Cloudnet processing chain, which depends on temperature and the depolarization ratio (LDR), faces issues with height-based false alarms and misclassifications during precipitation, especially when LDR data are missing. This study introduces and assesses a deep learning (DL) algorithm for identifying clear-air echoes across multiple sites and climatic conditions. Compared to the Cloudnet algorithm, the DL model provides more continuous classifications and notably reduces errors—reducing cloud-base height underestimation by 19.5% and false detection of meteorological echoes by 1.7%. Furthermore, seasonal analyses of the 1-year dataset at Cloudnet sites with different geophysical features (Jülich, Germany and Lampedusa, Italy) reveal that the influence of temperature on clear-air echoes varies significantly across environments. As a result, a single temperature-based probability function is insufficient to robustly distinguish non-meteorological echoes under diverse climatic conditions. These findings highlight the robustness of DL methods and their potential to enhance cloud radar data quality in complex observational environments. Full article

An analysis was conducted using AERONET Inversion Data at Thessaloniki and Leipzig stations. Aerosol type plays a vital role in determining their ability to act as CCN or INP, as properties such as chemical composition, morphology, and particle size influence their hygroscopic and ice-nucleating behavior. The CALIPSO mission provides global aerosol classification with vertical resolution by using backscatter intensity and depolarization ratio measurements. Aerosol typing from CALIPSO overpasses within 100 km of each selected AERONET station was used. Only pure aerosol cases (dust, polluted continental, smoke) were selected. This study combines AERONET-derived microphysical properties with CALIPSO aerosol classification to estimate particle number concentrations relevant for CCN and INP formation. The aim is to derive improved conversion factors for each aerosol type, enabling their application in future CCN and INP concentration profiles. Full article

This study proposes a novel quality control method combining fuzzy logic and threshold discrimination for processing X-band dual-polarization radar data from Beijing. The method effectively eliminates non-precipitation echoes, including electromagnetic interference, clear-air echoes, and ground clutter through five key steps: (1) Identifying electromagnetic interference using continuity of reflectivity across adjacent elevation angles, radial mean correlation coefficient, and differential reflectivity; (2) Preserving precipitation data in ground clutter-mixed regions by jointly utilizing the difference in reflectivity before and after clutter suppression by the signal processor, and characteristic value proportions; (3) Developing a fuzzy logic algorithm with six parameters (e.g., reflectivity texture, depolarization ratio) for ground clutter and clear-air echoes removal; (4) Filtering echoes with missing dual-polarization variables using cross-elevation mean reflectivity, mean correlation coefficient, and valid range bin proportion; (5) Removing residual noise via radial/azimuthal reflectivity continuity analysis. Validation with 635 PPI scans demonstrates high identification accuracy across echo types: 93.5% for electromagnetic interference, 98.4% for ground clutter, 97.7% for clear-air echoes, and 98.2% for precipitation echoes. Full article

Cloud-aerosol interactions represent a critical uncertainty in climate systems. Using 2006–2021 CALIPSO products, we investigated upper tropospheric clouds and aerosol layers across four Russian regions: Western Plains, West Siberian Plain, Central Siberian Plateau, and Eastern Mountains. Top Cloud Optical Depth (TCOD), Top Depolarization Ratio of clouds (TDRc), and Layer Level (LLc) exhibit pronounced seasonal and diurnal variations, peaking during summer and nighttime when convection intensifies. Upper aerosol layers show low Total Aerosol Optical Depth (TAOD) and Color Ratio (CRa), often displaying multi-layered structures influenced by spring–summer dust transport and biomass burning. We constructed a correlation matrix of 49 parameter pairs (7 cloud × 7 aerosol parameters), revealing moderate positive correlations between cloud and aerosol layer heights under coexistence conditions. TDRc showed weak linear but strong nonlinear relationships with aerosol parameters, indicating complex coupling mechanisms beyond simple linear models. Nighttime observations demonstrated superior signal-to-noise ratios and correlation coefficients compared to daytime measurements. These findings enhance understanding of cloud-aerosol coupling at middle-high latitudes, providing parameterization constraints for improving global climate model representations of these processes. Full article

The objective of this study is to analyze microphysical parameters affecting visibility parameterizations of a freezing fog case that occurred on 19 February 2022, during the Cold Fog Amongst Complex Terrain (CFACT) project conducted in a high-elevation alpine valley in Utah, USA. Observations are collected using visibility, droplet spectra, ice crystal spectra, and aerosol spectral instruments, as well as in-situ meteorological instruments. Particle phase is determined from relative humidity with respect to water (RH_w) as well as ground cloud imaging probe (GCIP), ceilometer (CL61) depolarization ratio, and icing accumulation on the platforms. Results showed that freezing droplet density can affect visibility (Vis) up to 100 m during Vis less than 1 km. In addition, increasing volume can lead to up to a 2 μm increase in droplet radius due to a change in the chemical composition of aerosols from Sodium Chloride (NaCl) to Ammonium Nitrate (NH₄NO₃). Overall, comparisons suggested that Vis parameterizations are highly variable, and freezing fog conditions resulted in lower Vis values compared to warm fog microphysical parameterizations. Furthermore, riming of freezing fog conditions can lead to more than 50% uncertainty in Vis. It is concluded that changing aerosol composition and freezing fog droplet density and riming can play a major role in Vis simulations. Full article

Aerosols play an important role in global meteorology and climate, as well as in air transport and human health, but there are still many unknowns on their effects and importance, in particular for the coarser (giant and ultragiant) aerosol particles. In this study, we aim to exploit the synergy between Raman lidar and Ka-band cloud radar to enlarge the size range in which aerosols can be observed and characterized. To this end, we developed an inversion technique that retrieves the aerosol microphysical properties based on cloud radar reflectivity and linear depolarization ratio. We applied this technique to a 6-year-long dataset, which was created using a recently developed methodology for the identification of giant aerosols in cloud radar measurements, with measurements from Potenza in Italy. Similarly, using collocated and concurrent lidar profiles, a dataset of aerosol microphysical properties using a widely used inversion technique complements the radar-retrieved dataset. Hence, we demonstrate that the combined use of lidar- and radar-derived aerosol properties enables the inclusion of particles with radii up to 12 µm, which is twice the size typically observed using atmospheric lidar alone. Full article

Colorectal cancer (CRC) remains a predominant cause of global cancer-related mortality, highlighting the pressing demand for innovative therapeutic strategies. Natural polysaccharides have emerged as promising candidates in cancer research due to their multifaceted anticancer mechanisms and tumor-suppressive potential across diverse malignancies. In this study, we enzymatically extracted a polysaccharide, named ERPP, from Ruditapes philippinarum and comprehensively evaluated its anti-colorectal cancer activity. We conducted in vitro assays, including CCK-8 proliferation, clonogenic survival, scratch wound healing, and Annexin V-FITC/PI apoptosis staining, and the results demonstrated that ERPP significantly inhibited HT-29 cell proliferation, suppressed colony formation, impaired migratory capacity, and induced apoptosis. JC-1 fluorescence assays provided further evidence of mitochondrial membrane potential (MMP) depolarization, as manifested by a substantial reduction in the red/green fluorescence ratio (from 10.87 to 0.35). These antitumor effects were further validated in vivo using a zebrafish HT-29 xenograft model. Furthermore, ERPP treatment significantly attenuated tumor angiogenesis and downregulated the expression of the vascular endothelial growth factor A (Vegfaa) gene in the zebrafish xenograft model. Mechanistic investigations revealed that ERPP primarily activated the mitochondrial apoptosis pathway. RT-qPCR analysis showed an upregulation of the pro-apoptotic gene Bax and a downregulation of the anti-apoptotic gene Bcl-2, leading to cytochrome c (CYCS) release and caspase-3 (CASP-3) activation. Additionally, ERPP exhibited potent antioxidant capacity, achieving an 80.2% hydroxyl radical scavenging rate at 4 mg/mL. ERPP also decreased reactive oxygen species (ROS) levels within the tumor cells, thereby augmenting anticancer efficacy through its antioxidant activity. Collectively, these findings provide mechanistic insights into the properties of ERPP, underscoring its potential as a functional food component or adjuvant therapy for colorectal cancer management. Full article

B-raf (rapidly accelerated fibrosarcoma) is a crucial player within the ERK/MAPK signaling pathway. In the CNS, B-raf has been implicated in neuronal differentiation, long-term memory, and major depression. Mice with forebrain neuron-specific B-raf knockout show behavioral deficits in spatial learning tasks and impaired hippocampal long-term potentiation (LTP). To elucidate the mechanism(s) underlying diminished synaptic plasticity in B-raf-deficient mice, we performed whole-cell recordings from CA1 pyramidal cells in hippocampal slices of control and B-raf mutant mice. We found that the NMDA/AMPA ratio of excitatory postsynaptic currents (EPSCs) at the Schaffer collateral—CA1 pyramidal cell synapses was significantly reduced in B-raf mutants, which would at least partially account for their impaired LTP. Interestingly, the reduced NMDA component of field postsynaptic potentials in mutant preparations was partially reinstated by blocking the apamin-sensitive small-conductance Ca²⁺-activated K⁺ (SK) channels, which have also been reported to modulate hippocampal LTP and learning tasks. To determine the impact of B-raf-dependent signaling on SK current, we isolated the apamin-sensitive tail current after a strong depolarizing event and found indeed a significantly bigger SK current in B-raf-deficient cells compared to controls, which is consistent with the reduced action potential firing and the stronger facilitating effect of apamin on CA1 somatic excitability in B-raf-mutant hippocampus. Our data suggest that B-raf signaling readjusts the delicate balance between NMDA receptors and SK channels to promote synaptic plasticity and facilitate hippocampal learning and memory. Full article

Approximately 90% of liver cancer cases are classified as hepatocellular carcinomas (HCCs), with chemotherapy and immunotherapy being the most recommended treatment options. While conventional chemotherapy specifically targets rapidly dividing cancer cells, it can also impact on healthy cells that are proliferating quickly. This collateral damage to healthy cells, along with the potential for cancer cells to develop resistance, presents significant challenges for conventional chemotherapy in liver cancer patients. Hepatic artery infusion of chemotherapy (HAIC) generally leads to reduced toxicity and fewer side effects. The process of catheter insertion is usually performed under local anesthesia, with lidocaine being the preferred choice to combine with various chemotherapeutics in HCC treatment. In our study, we explored the effects of repurposing lidocaine in combination with cisplatin or 5-fluorouracil (5-FU) on two HCC cell lines, HepG2 and Hep3B. Our cytotoxicity analysis revealed that lidocaine functions as a chemosensitizer for cisplatin and 5-FU in both HepG2 and Hep3B cells. Specifically, we observed an increase in the subG1 population and a reduction in cytosolic reactive oxygen species in cisplatin- or 5-FU-treated HepG2 and Hep3B cells. Interestingly, lidocaine selectively decreased the reduced/oxidized glutathione ratio in cisplatin- or 5-FU-treated HepG2 cells but not in Hep3B cells. Furthermore, lidocaine induced endoplasmic reticulum stress, apoptosis, mitochondrial membrane depolarization, lipid peroxidation, and autophagy while suppressing cellular proliferation HepG2 and Hep3B cells. In conclusion, our study demonstrates the synergistic potential of combining lidocaine with cisplatin or 5-FU for the treatment of HCC, indicating that lidocaine may serve as an effective chemosensitizer. These findings highlight a new clinical advantage of using repurposing lidocaine as a chemosensitizer in the current HAIC procedure, suggesting that this combination warrants further exploration through rigorous clinical trials. In the future, we can better optimize therapeutic regimens, potentially leading to improved patient outcomes in HCCs. Full article

This study describes a quite special and interesting atmospheric event characterized by the simultaneous presence of fresh and aged smoke layers. These peculiar conditions occurred on 16 July 2024 at the CNR-IMAA atmospheric observatory (CIAO) in Potenza (Italy), and represent an ideal case for the evaluation of the impact of aging and transport mechanisms on both the optical and microphysical properties of biomass burning aerosol. The fresh smoke was originated by a local wildfire about 2 km from the measurement site and observed about one hour after its ignition. The other smoke layer was due to a wide wildfire occurring in Canada that, according to backward trajectory analysis, traveled for about 5–6 days before reaching the observatory. Synergetic use of lidar, ceilometer, radar, and microwave radiometer measurements revealed that particles from the local wildfire, located at about 3 km a.s.l., acted as condensation nuclei for cloud formation as a result of high humidity concentrations at this altitude range. Optical characterization of the fresh smoke layer based on Raman lidar measurements provided lidar ratio (LR) values of 46 ± 4 sr and 34 ± 3 sr, at 355 and 532 nm, respectively. The particle linear depolarization ratio (PLDR) at 532 nm was 0.067 ± 0.002, while backscatter-related Ångström exponent (AEβ) values were 1.21 ± 0.03, 1.23 ± 0.03, and 1.22 ± 0.04 in the spectral ranges of 355–532 nm, 355–1064 nm and 532–1064 nm, respectively. Microphysical inversion caused by these intensive optical parameters indicates a low contribution of black carbon (BC) and, despite their small size, particles remained outside the ultrafine range. Moreover, a combined use of CIAO remote sensing and in situ instrumentation shows that the particle properties are affected by humidity variations, thus suggesting a marked particle hygroscopic behavior. In contrast, the smoke plume from the Canadian wildfire traveled at altitudes between 6 and 8 km a.s.l., remaining unaffected by local humidity. Absorption in this case was higher, and, as observed in other aged wildfires, the LR at 532 nm was larger than that at 355 nm. Specifically, the LR at 355 nm was 55 ± 2 sr, while at 532 nm it was 82 ± 3 sr. The AEβ values were 1.77 ± 0.13 and 1.41 ± 0.07 at 355–532 nm and 532–1064 nm, respectively and the PLDR at 532 nm was 0.040 ± 0.003. Microphysical analysis suggests the presence of larger, yet much more absorbent particles. This analysis indicates that both optical and microphysical properties of smoke can vary significantly depending on its origin, persistence, and transport in the atmosphere. These factors that must be carefully incorporated into future climate models, especially considering the frequent occurrences of fire events worldwide. Full article

This paper serves as a comprehensive “starter pack” for electrical diagnostic methods for power transformers. It offers a thorough review of electrical diagnostic techniques, detailing the required instrumentation and highlighting key research directions. The methods discussed include frequency response analysis, partial discharge testing, dielectric dissipation factor (tan delta), direct current (DC) insulation resistance, polarization index, transformer turns ratio test, recovery voltage measurement, polarization–depolarization currents, frequency domain spectroscopy, breakdown voltage testing, and power factor and capacitance testing. Additionally, the paper brings attention to less-explored electrical diagnostic techniques from the past decade. For each method, the underlying principles, applications, necessary instrumentation, advantages, and limitations are carefully examined, alongside emerging trends in the field. A notable shift observed over the past decade is the growing emphasis on hybrid diagnostic approaches and artificial intelligence (AI)-driven data analytics for fault detection. This study serves as a structured reference for researchers—particularly those in the early stages of their careers—as well as industry professionals seeking to explore electrical diagnostic techniques for power transformer condition assessment. It also outlines promising research avenues, contributing to the ongoing evolution of transformer diagnostics. Full article

Temperature and humidity profile lidar is one of the important means of urban atmospheric environment monitoring, which can capture atmospheric elements such as lidar ratio, color ratio, depolarization ratio, Ångström exponent, and temperature and humidity profile with research values. This study was based on the observation results of temperature and humidity profile lidar in Harbin and discusses the changes in the urban atmospheric environment under different conditions. The interaction processes between water vapor, temperature, and particulate matter, including aggregation, diffusion, phase transition, and transport, were explored under the main factor of anthropogenic pollution. This article analyzes the mutual influence of these atmospheric parameters in different environments, highlighting the important impact of temperature and humidity on the formation and diffusion of pollutants during pollution events. It supplements more data on urban atmospheric environment monitoring in the region and provides more data support for urban environmental governance. Full article

Vertically retrieved optical properties by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) were investigated in the case of three selected events over Athens and Thessaloniki with documented high pollen concentrations. Hirst-type volumetric samplers were used to detect and characterize the pollen during the CALIPSO overpasses. Only cases with a total pollen concentration greater than 400 grains m⁻³ for at least two hours per day were considered severe pollen events, while model simulations were used to exclude the presence of other depolarizing aerosol types. This study provides mean values of lidar-derived optical properties inside the detected pollen layers; i.e., optical values represent the atmosphere with the presence of pollen, in urban cities of Greece. Specifically, three observed aerosol layers, one over Athens and two over Thessaloniki with particulate color ratios of 0.652 ± 0.194, 0.638 ± 0.362, and 0.456 ± 0.284, and depolarization ratios of 8.70 ± 6.26%, 28.30 ± 14.16%, and 8.96 ± 6.87%, respectively, were misclassified by CALIPSO as marine-dusty marine, dust, and polluted dust. In cases of intense pollen presence, CALIPSO vertical profiles and aerobiological monitoring methods may be used synergistically to better characterize the atmospheric pollen layers. Full article

Background/Objectives: Early extubation is crucial for enhancing recovery from coronary artery bypass grafting (CABG). Residual neuromuscular blockade (NMB) effects can hinder early extubation, potentially leading to reintubation, lung infection, and prolonged post-anesthesia stay. Sugammadex, a modified gamma-cyclodextrin, reverses the non-depolarizing NMB effects of the steroidal muscle relaxants rocuronium and vecuronium. The American Society of Anesthesiologists recommends sugammadex administration when patients display a train-of-four (TOF) ratio of less than 0.9. Previous studies show that sugammadex decreases extubation times, reduces postoperative complications, and enhances patient comfort. Methods: This single-center, retrospective cohort study evaluated the efficacy of sugammadex in achieving extubation within six hours of intensive care unit (ICU) arrival post-CABG, defined as fast-track extubation (FTE). Results: Here, we report that although the total time of intubation in the ICU following CABG did not drop to the six-hour benchmark, it was substantially reduced by the administration of sugammadex in accordance with an FTE protocol. Furthermore, the risks of adverse events (e.g., anaphylaxis, heart failure) and postoperative complications (e.g., acidemia, hypoxemia, tachypnea) were unaltered. Conclusions: The use of sugammadex could, thus, reduce costs associated with prolonged intubation time and related complications without increasing morbidity or mortality. Full article

We present a multi-year study of Saharan dust intrusions on a mountainous site located in the central Mediterranean Basin regarding their aerosol optical and geometrical properties. The observations were carried out at the Consiglio Nazionale delle Ricerche-Istituto di Metodologie per l’Analisi Ambientale (CNR-IMAA) located in Potenza (40,360N, 15,440E), Italy, from March 2010 to October 2022, using ACTRIS (Aerosol Clouds and Trace Gases Research InfraStructure). A total of 101 night-time lidar measurements of dust intrusions were identified. The following properties were calculated for the periods December, January, February (DJF), March, April, May (MAM), June, July, August (JJA) and September, October, November (SON): aerosol layer center of mass altitude, particle lidar ratio at 355 and 532 nm, particle depolarization ratio at 532 nm and backscattering Ångström exponent at 532–1064 nm. Both geometrical and optical aerosol properties vary considerably with the seasons. During SON and DJF, air masses transporting dust travel at lower altitudes, and become contaminated with local continental particles. In MAM and JJA, dust is also likely to travel at higher altitudes and rarely mix with other aerosol types. As a result, aerosols are larger in size and irregular in shape during the warm months. The ratio of the lidar ratios at 355 and 532 nm is 1.11 ± 0.15 in DJF, 1.12 ± 0.07 in SON, 0.94 ± 0.12 in MAM, and 0.92 ± 0.08 in JJA. The seasonal radiative effect estimated using the Fu–Liou–Gu (FLG) radiative transfer model indicates the most significant impact during the JJA period. A negative dust radiative effect is observed both at the surface (SRF) and at the top of the atmosphere (TOA) in all the seasons, and this could be related to a minimal contribution from black carbon. Specifically, the SRF radiative effect estimation is −14.48 ± 1.32 W/m² in DJF, −18.00 ± 0.89 W/m² in MAM, −22.08 ± 1.36 W/m² in JJA, and −13.47 ± 1.12 W/m² in SON. Instead, radiative effect estimation at the TOA is −22.23 ± 2.06 W/m² in DJF, −38.23 ± 2.16 W/m² in MAM, −51.36 ± 3.53 W/m² in JJA, and −22.57 ± 2.11 W/m² in SON. The results highlight how the radiative effects of the particles depend on the complex relationship between the dust load, their altitude in the troposphere, and their optical properties. Accordingly, the knowledge of aerosols optical property profiles is of primary importance to understand the radiative impact of dust. Full article