RESUMEN
It is a great demand to develop high-performance electrodes for metal-air batteries to boost cathodic oxygen reduction/evolution dynamics and avoid anodic dendrites. The optimization of catalysis at electrode can be conducted by increasing effective surface exposure, active site density, and unsaturated coordination, via using metal clusters or atomic catalysts, along with conductive or defective supports. Herein, the polarized and synergistic cooperation between dual single atom sites (Fe-N4/Co-N4) are developed through electrolytical exfoliation of defect-enriched π-conjugated macrocyclic polyphthalocyanines to expose more active sites on hollow carbonized shells (HCS). Such FeCo-N4/HCS exhibits outstanding performance in oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), to achieve high-performance in an aqueous zinc battery (AZB) with a high discharge capacity (763.6 mAhg-1) after 750 cycles at 10 mA cm-2, showing stable discharge voltage and excellent durability. It also possesses high performance in a lithium-O2 battery owing to abundant defects, synergistic Fe-N4/Co-N4 active sites, reduced energy barriers, and boosted charge and mass transfer and reaction kinetics. This study provides novel perspectives to expand dual single-metal catalysts on macrocycles in the exploration of efficient, durable, and eco-friendly energy devices.
RESUMEN
In order to study the integration of reticuloendotheliosis virus (REV) in pigeonpox virus (PPV), we collected suspected pigeonpox disease material, amplified the 4b core protein gene of PPV, the gp90 gene of REV, and the integrated sequence fragments from the end of the ORF201 segment of PPV to the beginning of the LTR of REV, and sequenced these genes. The results showed that a 4b core protein fragment of 332 bp was amplified and identified as pigeonpox virus, which was named SX/TY/LTR 01/2023. Sequence analysis showed that the pigeonpox virus isolate belonged to genotype A2, which was the closest to the domestic CVL strain, with a identity of 99.4%. A band of 1191 bp was amplified from the gp90 gene of REV, named SX/TY/PPV-REV01/2023, and sequence analysis indicated that REV belonged to genotype III. The sequence analysis showed that REV belonged to genotype III, and belonged to the same large branch as the domestic isolates JSRD0701 and LNR0801, with 99.3% identity. The integrated sequence fragment was amplified to a band of 637 bp, which determined that the REV sequence was integrated in the PPV rather than a mixed infection of the two viruses. This indicates that REV was integrated in this isolation of PPV, suggesting that pigeon farms need to prevent reticuloendotheliosis at the same time when preventing pigeonpox.
RESUMEN
Graphene quantum dots (GQDs) possess the photosensitive absorption for photoelectrochemical hydrogen evolution owing to special band structures, whereas they usually confront with photo-corrosion or undesired charge recombination during photoelectrochemical reactions. Hence, we establish the heterojunction between GQDs and MoSe2 sheets via a hydrothermal process for improved stability and performance. Photoanodic water splitting with hydrogen evolution boosted by the heteroatom doped N,S-GQDs/MoSe2 heterojunction has been attained due to the abundant active sites, promoted charge separation and transfer kinetics with reduced energy barriers. Diphasic 1T and 2H MoSe2 sheet-hybridized quantum dots contribute to the Schottky heterojunction, which can play a key role in expedited carrier transport to inhibit accumulative photo-corrosion and increase photocurrent. Heteroatom dopants lead to favored energy band matching, bandgap narrowing, stronger light absorption and high photocurrent density. The external quantum efficiency of the doped heterojunction has been elevated twofold over that of the non-doped pristine heterojunction. Modification of the graphene quantum dots and MoSe2 heterojunction demonstrate a viable and adaptable platform toward photoelectrochemical hydrogen evolution processes.
RESUMEN
Two new three-dimensional organic-inorganic hybrid crystalline materials, [(Ade)2 CdCl4] (1) and [(Ade)2 CdBr4] (2), were obtained by the slow evaporation of adenine (Ade) and cadmium chloride in aqueous solution at room temperature with hydrochloric acid and hydrobromic acid used as halogen sources. The structural, thermal, optical, and electrical properties were characterized by single-crystal X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, variable-temperature-variable-frequency dielectric constant analysis, and electrochemical tests. With increasing the substitution of Cl by Br, the composition of the material changed and the space group shifted from P-1 to P21/m, with a significant blue-shift in the fluorescence emission. Changing the temperature induced the deformation of the three-dimensional framework structure formed by hydrogen bonding interactions, leading to dielectric anomalies. Cyclic voltammetry tests showed the good reversibility of the electrolysis process. The structural diversity of the complexes was realized by modulating the halogen composition, and a new method for designing novel organic-inorganic hybrids with controllable photoelectric functionality was proposed.
RESUMEN
Objective.Automated segmentation of targets in ultrasound (US) images during US-guided liver surgery holds the potential to assist physicians in fast locating critical areas such as blood vessels and lesions. However, this remains a challenging task primarily due to the image quality issues associated with US, including blurred edges and low contrast. In addition, studies specifically targeting liver segmentation are relatively scarce possibly since studying deep abdominal organs under US is difficult. In this paper, we proposed a network named BAG-Net to address these challenges and achieve accurate segmentation of liver targets with varying morphologies, including lesions and blood vessels.Approach.The BAG-Net was designed with a boundary detection module together with a position module to locate the target, and multiple attention-guided modules combined with the depth supervision strategy to enhance detailed segmentation of the target area.Main Results.Our method was compared to other approaches and demonstrated superior performance on two liver US datasets. Specifically, the method achieved 93.9% precision, 91.2% recall, 92.4% Dice coefficient, and 86.2% IoU to segment the liver tumor. Additionally, we evaluated the capability of our network to segment tumors on the breast US dataset (BUSI), where it also achieved excellent results.Significance.Our proposed method was validated to effectively segment liver targets with diverse morphologies, providing suspicious areas for clinicians to identify lesions or other characteristics. In the clinic, the method is anticipated to improve surgical efficiency during US-guided surgery.
Asunto(s)
Hígado , Ultrasonografía Mamaria , Femenino , Humanos , Cintigrafía , Ultrasonografía , Hígado/diagnóstico por imagen , Hígado/cirugía , Ultrasonografía Intervencional , Procesamiento de Imagen Asistido por ComputadorRESUMEN
Soil potentially toxic elements (PTEs) pollution of contaminated sites has become a global environmental issue. However, given that previous studies mostly focused on pollution assessment in surface soils, the current status and environmental risks of potentially toxic elements in deeper soils remain unclear. The present study aims to cognize distribution characteristics and spatial autocorrelation, pollution levels, and risk assessment in a stereoscopic environment for soil PTEs through 3D visualization techniques. Pollution levels were assessed in an integrated manner by combining the geoaccumulation index (Igeo), the integrated influence index of soil quality (IICQs), and potential ecological hazard index. Results showed that soil environment at the site was seriously threatened by PTEs, and Cu and Cd were ubiquitous and the predominant pollutants in the study area. The stratigraphic models and pollution plume simulation revealed that pollutants show a decreasing trend with the deepening of the soil layer. The ranking of contamination soil volume is as follows: Cu > Cd > Zn > As > Pb > Cr > Ni. According to the IICQs evaluation, this region was subject to multiple PTE contamination, with more than 60% of the area becoming seriously and highly polluted. In addition, the ecological hazard model revealed the existence of substantial ecological hazards in the soils of the site. The integrated potential ecological risk index (RI) indicated that 45.7%, 10.13%, and 4.15% of the stereoscopic areas were in considerable, high, and very high risks, respectively. The findings could be used as a theoretical reference for applying multiple methods to integrate evaluation through 3D visualization analysis in the assessment and remediation of PTE-contaminated soils.
Asunto(s)
Monitoreo del Ambiente , Metales Pesados , Minería , Contaminantes del Suelo , Suelo , Contaminantes del Suelo/análisis , Monitoreo del Ambiente/métodos , Suelo/química , Medición de Riesgo/métodos , Metales Pesados/análisis , Contaminación Ambiental/análisis , CiudadesRESUMEN
Styrene-maleic acid (SMA) copolymer has received much attention for its excellent solubilization characteristics. In this work, SMA copolymer brush-based chromatographic stationary phases were exploited and developed for the first time. First, SMA copolymer brush was in situ grown on the surface of spherical silica via living/controlled reversible addition-fragmentation chain transfer (RAFT) polymerization method. Subsequently, as a proof-of-concept demonstration, the copolymer was esterified by diethylene glycol mono-2-ethylhexyl ether (DGME) and 2-(2-ethylhexyloxy) ethanol (EHOE), respectively. The obtained Sil-SMA-DGME and Sil-SMA-EHOE copolymer-brush chromatographic stationary phases were characterized by transmission electron microscopy, Fourier transform infrared spectrometer, X-ray photoelectron spectroscopy, and thermogravimetric analysis, respectively. The chromatographic retention mechanism indicated that both the two packed columns exhibited hydrophilic/reverse mixed-mode retention modes. The maximum column efficiency was up to 71,000 N/m. The chromatographic separation performance evaluation indicated that the novel kind of stationary phases had excellent separation capabilities for hydrophilic, hydrophobic compounds and phospholipid standards. In addition, by combination with mass spectrometry identification, the Sil-SMA-DGME column was further exploited for separation and identification of phospholipids in human lung cancer cells. Totally, 9 classes including 186 phospholipid species were successfully identified. The results demonstrated the promising application prospects of the novel kind of SMA copolymer-brush chromatographic stationary phases.
RESUMEN
Ultrasound-guided percutaneous interventions have numerous advantages over traditional techniques. Accurate needle placement in the target anatomy is crucial for successful intervention, and reliable visual information is essential to achieve this. However, previous studies have revealed several challenges, such as the variability in needle echogenicity and the common misalignment of the ultrasound beam and the needle. Advanced techniques have been developed to optimize needle visualization, including hardware-based and image-processing-based methods. This paper proposes a novel strategy of integrating ultrasound-based deep learning approaches into an optical navigation system to enhance needle visualization and improve tip positioning accuracy. Both the tracking and detection algorithms are optimized utilizing optical tracking information. The information is introduced into the tracking network to define the search patch update strategy and form a trajectory reference to correct tracking results. In the detection network, the original image is processed according to the needle insertion position and current position given by the optical localization system to locate a coarse region, and the depth-score criterion is adopted to optimize detection results. Extensive experiments demonstrate that our approach achieves promising tip tracking and detection performance with tip localization errors of 1.11 ± 0.59 mm and 1.17 ± 0.70 mm, respectively. Moreover, we establish a paired dataset consisting of ultrasound images and their corresponding spatial tip coordinates acquired from the optical tracking system and conduct real puncture experiments to verify the effectiveness of the proposed methods. Our approach significantly improves needle visualization and provides physicians with visual guidance for posture adjustment.