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Association of gut microbiota and immunometabolic profiles with ischemic stroke severity
Involving Carbene or Not? Mechanism of Corey–Winter Reaction
Development of manganese ferrite coated with Prussian blue as an efficient contrast agent for applications in magnetic resonance imaging
Abstract Magnetic iron oxide nanoparticles are frequently utilized as contrast agents in magnetic resonance imaging (MRI). However, the release of iron ions leads to the formation of reactive oxygen species (ROS), resulting in cell damage. In this study, we developed MRI contrast agents containing amine-functionalized MnFe2O4 nanoparticles with a Prussian blue (PB) surface coating to enhance their biocompatibility. The prepared MNPs were embedded in polyvinylpyrrolidone and dried. The resulting crystals can be redispersed in water immediately before use, forming a stable colloid. The particle size of nanoparticles (43 ± 13 nm) is suitable for the intended application. The values of Hc (52 Oe) and Mr (3.7 emu/g) for the particles indicate a soft ferromagnetic nature. The coating of the particles with PB results in a significant reduction of their toxicity, as evidenced by a toxicological test on HEK293 cells. This colloid was tested in vitro as an MRI contrast agent as well as in healthy animal. The longitudinal relaxivity (r1) of the PB-MnFe2O4-NH2 sample was determined to be 0.01 (mg/mL)−1ms− 1. The transversal relaxivity was measured as well (r2: 0.77 (mg/mL)−1ms− 1 and r2*: 1.48 (mg/mL)−1ms− 1, which were in the same range as Feraheme and Endorem. Prussian blue-coated MnFe2O4 emerges as a promising T2-weighted contrast material, representing a novel combination of two well-known contrast-capable materials.
Cyclic Bifunctional Reagents Enabling a Strain-Release-Driven Formal [3 + 2] Cycloaddition of 2<i>H</i>-Azirines by Cascade Energy Transfer
Open-circuit diagnosis method based on dual-mode voltage residual model for T-type three-level inverter
Abstract This study proposes a rapid online diagnostic method based on a dual-mode line voltage residual model for diagnosing IGBT open-circuit faults in a T-type three-level inverter. The method is based on the voltage residual method and is integrated with a three-level fault-tolerant algorithm. Firstly, by analyzing the line voltage residuals after an open-circuit fault in the T-type inverter under normal operating conditions, 12 types of single-switch open-circuit faults are divided into 6 groups. Next, the breakdown of the spatial voltage vectors following the fault are analyzed, and the remaining vectors are reconfigured to enable the inverter’s operation under three-level fault-tolerant control. In the fault-tolerant control, the residual voltage returns to its normal value, aiding in precise fault localization. Simulation and experimental results validate the method’s robustness against load variations. This method significantly increases diagnostic speed and reduces harmonic interference in the diagnosis procedure. These findings are of paramount importance for fault diagnosis and the reliable operation of the T-type three-level inverter.
Rational Design of PROTAC Linkers Featuring Ferrocene as a Molecular Hinge to Enable Dynamic Conformational Changes
Critical success factors for successful technology innovation development in sustainable energy enterprises
Regiodivergent Hydroamidation of Alkenes via Cobalt-Hydride Catalysis
First record of a living coelacanth from North Maluku, Indonesia
Regulating Enol-to-Keto Tautomerization of Pillararene-Based Conjugated Macrocycle Polymers for H<sub>2</sub>O<sub>2</sub> Photosynthesis
Family structure factors influencing modern contraceptive use in Cameroon based on analysis of 2018–2019 demographic and health survey data
Rapid Access to Small Molecule Conformational Ensembles in Organic Solvents Enabled by Graph Neural Network-Based Implicit Solvent Model
Epidemiological and spatiotemporal analysis of elderly HIV-1/AIDS patients in Ningxia, China, from 2018 to 2023
Abstract To analyze the epidemiological transmission characteristics and spatiotemporal distribution patterns of the elderly HIV-1/AIDS population in NHAR from 2018 to 2023, to provide theoretical support for the targeted formulation and implementation of HIV-1 interventions. A cross-sectional study was conducted in August 2024. Plasma samples were collected from the elderly HIV-1/AIDS patients (> 50 years old) in NHAR, followed by RNA extraction and RT-PCR to amplify the pol gene of HIV-1. The amplicons were sequenced for the partial pol region. Subtyping was performed using online tools from the HIV-1 database and MEGA11. Drug resistance was analyzed using the Stanford University HIVdb algorithm. Molecular transmission networks were constructed using Cytoscape 3.10.0. Logistic regression was performed to identify the potential risk factors. Spatial analysis revealed the geographic patterns of elderly HIV-1/AIDS patients. A total of 208 HIV-1/AIDS patients were included in this study, predominantly male (78.37%), primary school and below (46.63%), heterosexual transmission (80.77%) and farmers (52.40%). Nine genetic subtypes were identified, with CRF07_BC being the most common (54.81%). The overall drug resistance rate was 37.98%. The number of network nodes increased from 18 in 2018 to 107 in 2023, with large propagating clusters in 2023 merging or expanding from smaller clusters in previous years. Logistic regression analysis showed that males had a lower risk of transmission, individuals from Yinchuan, Shizuishan, and Wuzhong had a lower probability of entering the network, and CRF07_BC and CRF01_AE had a higher risk of transmission. From 2020 to 2023, there was a highly significant clustering pattern among elderly HIV/AIDS patients in NHAR, with shifts in hotspots. Yuanzhou District remained a persistent cold spot. This study reveals that the elderly HIV-1/AIDS patients in NHAR were predominantly married, male, and engaged in farming, with low levels of education. An increase in the diversity of viral genetic subtypes was observed, along with a high rate of drug resistance. The molecular network expanded significantly, accompanied by the emergence of large transmission clusters, indicating complex transmission patterns. The spatial distribution of these cases exhibited aggregation, with notable differences observed between districts and counties. To effectively intervene in the transmission of HIV-1 among the elderly population, it is essential to establish a long-term dynamic molecular transmission surveillance network and to improve AIDS screening and drug resistance testing.