This study seeks to provide a basic approach to fulfill the spatial visualization of geopolitical environmental factors required for the navigation of vessels in the Arctic. Multi-dimensional ...geopolitical environmental factors of the Arctic Passage are analyzed and classified into geopolitics, geoeconomics, geo-military, geoculture, and laws and regulations related to geography. Their characteristics are extracted to form an attribute information table matching spatial layers. Based on the information category and basic characteristics, the spatial match method is applied and connected with the spatial layers to examine the spatial point, polyline, and polygon. According to the qualitative description, the study extracted the quantitative indicators for the following spatial–temporal pattern analysis. The standard deviational ellipse is used to analyze the spatial–temporal patterns and trends of the geopolitical environmental indicators of the Arctic Passage in the Arctic and Northeast Asia. The expansion and contraction of geoinformation coexist in the countries surrounding the Arctic Passage. The spatial–temporal changes indicate that the Arctic channel has a great economic impact on the Nordic countries and Northeast Asia, especially the coastal areas of China and Japan. The characteristic extraction and spatial match of the geopolitical environment provide integrated Arctic geoinformation inquiry and services for the diplomatic, administrative, and legal preparations required for Arctic navigation. Therefore, the geospatial analysis conducted provides scientific support and a basis for the geographical distribution and developing trends of visualization and spatial–temporal pattern in Arctic navigation. The results of this research will help decision-makers to make a comprehensive judgment on governance related to the sustainable development of the Arctic Passage.
A peristaltic pelvic mass Wang, Li; Gao, Yimeng
Asian journal of surgery,
April 2024, 2024-Apr, 2024-04-00, 2024-04-01, Letnik:
47, Številka:
4
Journal Article
Impact damage of carbon fiber reinforced polymers (CFRP) composites is a common form of damage in composite structures. In this work, a model integrating the structure model of composites, failure ...model and contact model with friction based on ordinary state-based peridynamics (PD) theory is developed to simulate multiple impacts of CFRP. The simulation results of single impact are in good agreement with the existing experimental and finite element simulation results, validating the proposed PD model. Then the effects of impact energy, stacking sequences and impact angles on the CFRP damage behaviors under multiple impacts are thoroughly investigated. Multiple high energy impacts may cause a non-linear increase in the amount of damage. The peanut-shaped stress distributions induced by impact along different directions are typical of the stress responses, which usually correspond to different fiber directions. Moreover, the laminates with stacking sequences of different fiber directions have a better impact damage resistance, as they can hinder the propagation of stress waves across the layers. In addition, as the impact angle increases, the stress and damage become more pronounced. The insights gained shed light on the repeated impact damage mechanisms of CFRP.
Exosomes carrying abundant information have aroused great interest as effective biomarkers in liquid biopsy and are therefore ideal candidates for the early diagnosis of cancer and treatment ...monitoring. Herein, we developed a sensitive electrochemical biosensor using in situ generation of Fe₄Fe(CN)6₃ (Prussian Blue) on the surface of Ti3C2 MXene (two-dimensional transition-metal carbides) as hybrid nanoprobes (PB-MXene) for the detection of exosomes and their surface protein. A CD63 aptamer-modified poly(amidoamine) (PAMAM)-Au NP electrode interface was fabricated that can specifically bind with CD63 protein on the exosomes derived from OVCAR cells. In addition, the CD63-modified Ti3C2 MXene was used as a nanocarrier to accommodate numerous aptamers and was adsorbed on the exosomes. The Ti3C2 MXene can realize the in situ generation and high-efficiency loading of PB and further amplify the electrochemical signal at a low potential, thus avoiding the interference of the electrochemical active species. The dual amplification effect enables highly selective and sensitive electrochemical detection of exosomes. The limit of detection (LOD) was 229 particles μL−1 with a linear range from 5 × 102 particles μL−1 to 5 × 105 particles μL−1. An electrochemical biosensor can detect exosomes secreted by various cancer cells such as HeLa, OVCAR and BT474, and shows a high specificity even in serum samples, thus demonstrating its great potential in the application of clinical diagnostics. This proposed electrochemical biosensor provides a facile and efficient tool for the early diagnosis of cancers.
A novel and sensitive electrochemical biosensor using PB-MXene-Apt as the nanoprobe to achieve signal amplification at low potential was developed for exosomes detection. Display omitted
•The exosomes activity was analyzed by a novel electrochemical biosensor.•The Ti3C2 acted as reducing carrier to realize the in-situ generation of PB, amplifying the electrochemical signal.•The CD63 modified Ti3C2 MXene was used as the nanocarrier to accommodate numerous aptamers and adsorbed on the exosomes.•The electrochemical biosensor was performed successfully in serum, proving its great potential in clinical diagnostics.
A dandelion-like CNTs-Ni foam composite carrier supported Co–Mo–P ternary alloy catalyst (Co–Mo–P/CNTs-Ni foam) was prepared by electroless plating. The structure of Co–Mo–P/CNTs-Ni foam catalyst is ...characterized by XRD, SEM, XPS and EDS. The particle size of Co–Mo–P ternary alloy nanoparticles is about 80 nm. The Co–Mo–P/CNTs-Ni foam completely retains the tubular structure of carbon nanotubes and the gaps between carbon nanotubes of CNTs-Ni carrier, which increases the specific surface area of the catalyst and the flow space of reactants and products. Co–Mo–P/CNTs-Ni foam catalyzes sodium borohydride alcoholysis to produce hydrogen at a maximum rate of 2.64 L ·min−1 ·g−1, and the reaction activation energy is 47.27 kJ ·mol−1, which is far lower than that of the spontaneous alcoholysis reaction of sodium borohydride. After the Co–Mo–P/CNTs-Ni foam catalyst was reused 8 times, the catalytic hydrogen production rate was reduced by 23% compared with the initial rate.
•Prepare dandelion-like Co–Mo–P/CNTs-Ni foam catalyst.•The addition of Mo element increases the activity and stability of the catalyst.•The addition of Mo element reduces the activation energy of the reaction.
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•A novel hyperbranched zwitterionic polymer (PTS) is proposed as humidity sensing material.•The zwitterionic resonance structure can regulate the balance between response and ...recovery.•PTS/LiCl sensors exhibit fast response (0.2 s) over a wide test range (11–98% RH).•PTS-based sensors show excellent non-contact sensing properties and are integrated into a keyboard as a human–machine interface.
Non-contact humidity sensing is a prospective method for gathering biomedical information and realizing the non-screen-contact human–machine interaction. However, humidity sensors with both fast response and recovery are still considered a significant challenge. This study proposes to develop a humidity sensor based on hyperbranched zwitterionic polymer (PTS). The sensors are featured with fast response and recovery (3 s/3 s) as well as outstanding repeatability in the range of 11%-98% RH. The excellent sensing performance of PTS benefits from the rational regulation of molecular interactions. LiCl is then employed to dope the PTS to fabricate PTS/LiCl composite sensitive materials. The introduction of conductive ions further improves the sensing performance, and the modified humidity sensor exhibits an ultrafast response (0.2 s). The PTS/LiCl sensors demonstrate robust long-term stability and good anti-interference capability. Sensors are also developed into masks for respiratory status monitoring. A gesture monitoring keyboard is constructed by integrating sensor array panels with control circuits to recognize non-contact gestures. The results prove that hyperbranched zwitterionic polymers offer a promising perspective as humidity sensing materials for the application of biomedical monitoring and human machine interfaces (HMI).
Comprehensive preclinical studies of Myelodysplastic Syndromes (MDS) have been elusive due to limited ability of MDS stem cells to engraft current immunodeficient murine hosts. Here we report a MDS ...patient-derived xenotransplantation model in cytokine-humanized immunodeficient "MISTRG" mice that provides efficient and faithful disease representation across all MDS subtypes. MISTRG MDS patient-derived xenografts (PDX) reproduce patients' dysplastic morphology with multi-lineage representation, including erythro- and megakaryopoiesis. MISTRG MDS-PDX replicate the original sample's genetic complexity and can be propagated via serial transplantation. MISTRG MDS-PDX demonstrate the cytotoxic and differentiation potential of targeted therapeutics providing superior readouts of drug mechanism of action and therapeutic efficacy. Physiologic humanization of the hematopoietic stem cell niche proves critical to MDS stem cell propagation and function in vivo. The MISTRG MDS-PDX model opens novel avenues of research and long-awaited opportunities in MDS research.
A NiO–Ni foam composite carrier was prepared by the hydrothermal method. Ruthenium metal was supported on the NiO–Ni foam by electroplating, obtaining a highly active bush-like Ru/NiO–Ni foam ...catalyst. To investigate the effect of NiO on the structure and performance of the catalyst, a Ru/Ni foam catalyst was prepared as a reference. The structures of the carrier and both catalysts were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy, and the performances of both catalysts were evaluated in alcoholytic hydrogen production from sodium borohydride. On the carrier with the NiO-treated surface, the active component Ru developed a three-dimensional bush-like structure that enhanced the catalytic activity. Indeed, the hydrogen production from alcoholysis of sodium borohydride was three times higher on the Ru/NiO–Ni foam catalyst than on the Ru/Ni foam catalyst, and the highest rate exceeded 6 L/g/min. The repeated-use stability of the Ru/NiO–Ni catalyst (10 times) also exceeded that of Ru/Ni foam (8 times). However, as both catalysts used the same active component (i.e., Ru), their activation energies were almost identical.
Ultraviolet (UV) radiation is a major cause of photoaging that can induce DNA damage, oxidative stress, and cellular aging. Metformin (MF) can repair DNA damage, scavenge reactive oxygen species ...(ROS), and protect cells. However, the mechanism by which MF inhibits cell senescence in chronic skin damage induced by UVA is unclear. In this study, human foreskin fibroblasts (HFFs) treated with UVA were used as an in vitro model and UVA-induced skin photoaging in Kunming mice was used as an in vivo model to investigate the potential skin protective mechanism of MF. The results revealed that MF treatment attenuated UVA-induced cell viability, skin aging, and activation of the PI3K/AKT/mTOR signaling pathway. Furthermore, MF treatment alleviated the mitochondrial oxidative stress and decreased mitophagy. Knockdown of Parkin by siRNA increased the clearance of MF in senescent cells. The treatment of Kunming mice with MF at a dose of 10 mg/kg/day significantly reduced UVA-induced skin roughness, epidermal thinning, collagen degradation, and skin aging. In conclusion, our experimental results suggest that MF exerts anti-photoaging effects by inhibiting mitophagy and the PI3K/AKT/mTOR signaling pathway. Therefore, our study improves the current understanding of the protective mechanism of MF against photoaging.
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