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2.
Sci Bull (Beijing) ; 69(8): 1071-1080, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38302332

RESUMO

The commercialization of lithium-sulfur (Li-S) batteries has been hindered by the shuttle effect and sluggish redox kinetics of lithium polysulfides (LiPSs). Herein, we reported a viologen-based ionic conjugated mesoporous polymer (TpV-Cl), which acts as the cathode host for modifying Li-S batteries. The viologen component serves as a reversible electron conveyer, leading to a comprehensive enhancement in the adsorption of polysulfides and improved conversion rate of polysulfides during the electrochemical process. As a result, the S@TpV-PS cathode exhibits outstanding cycling performance, achieving 300 cycles at 2.0 C (1 C = 1675 mA g-1) with low decay rate of 0.032% per cycle. Even at a high sulfur loading of 4.0 mg cm-2, S@TpV-PS shows excellent cycling stability with a Coulombic efficiency of up to 98%. These results highlight the significant potential of S@TpV-PS in developing high-performance Li-S batteries.

3.
Microorganisms ; 12(2)2024 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-38399800

RESUMO

This study aimed to explore the phenotype and relationship of drug resistance genes in livestock and poultry farm wastewater and drinking water reservoirs to provide evidence for the transmission mechanisms of drug resistance genes, in order to reveal the spread of drug resistance genes in wastewater from intensive farms in Central China to urban reservoirs that serve as drinking water sources and provide preliminary data for the treatment of wastewater from animal farms to reduce the threat to human beings. DNA extraction and metagenomic sequencing were performed on eight groups of samples collected from four water reservoirs and four related wastewaters from animal farms in Central China. Metagenomic sequencing showed that the top 20 AROs with the highest abundance were vanT_gene, vanY_gene, adeF, qacG, Mtub_rpsL_STR, vanY_gene_, vanW_gene, Mtub_murA_FOF, vanY_gene, vanH_gene, FosG, rsmA, qacJ, RbpA, vanW_gene, aadA6, vanY_gene, sul4, sul1, and InuF. The resistance genes mentioned above belong to the following categories of drug resistance mechanisms: antibiotic target replacement, antibiotic target protection, antibiotic inactivation, and antibiotic efflux. The resistomes that match the top 20 genes are Streptococcus agalactiae and Streptococcus anginosus; Enterococcus faecalis; Enterococcus faecium; Actinomyces viscosus and Bacillus cereus. Enterococcus faecium; Clostridium tetani; Streptococcus agalactiae and Streptococcus anginosus; Streptococcus agalactiae and Streptococcus anginosus; Acinetobacter baumannii, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum, Corynebacterium jeikeium, Corynebacterium urealyticum, Mycobacterium kansasii, Mycobacterium tuberculosis, Schaalia odontolytica, and Trueperella pyogenes; Mycobacterium avium and Mycobacterium tuberculosis; Aeromonas caviae, Enterobacter hormaechei, Vibrio cholerae, Vibrio metoecus, Vibrio parahaemolyticus, and Vibrio vulnificus; Pseudomonas aeruginosa and Pseudomonas fluorescens; Staphylococcus aureus and Staphylococcus equorum; M. avium, Achromobacter xylosoxidans, and Acinetobacter baumannii; Sphingobium yanoikuyae, Acinetobacter indicus, Morganella morganii, Proteus mirabilis, Proteus vulgaris, Providencia rettgeri, and Providencia stuartii. Unreported drug resistance genes and drug-resistant bacteria in Central China were identified in 2023. In the transmission path of drug resistance genes, the transmission path from aquaculture wastewater to human drinking water sources cannot be ignored. For the sake of human health and ecological balance, the treatment of aquaculture wastewater needs to be further strengthened, and the effective blocking of drug resistance gene transmission needs to be considered.

4.
Open Med (Wars) ; 19(1): 20230860, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38221932

RESUMO

Purpose: This study identified subtypes and prognostic signature of stage I and stage II gastric cancer based on neutrophil extracellular trap (NET)-related genes. Methods: The gene expression data associated with stage I and stage II gastric cancer were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases. NET-related genes were obtained from previous reference. Differentially expressed NET-related genes were selected by consensus cluster analysis. The differences in immune infiltration between two subtypes were analyzed. Prognosis-related genes were further screened by univariate Cox regression analysis. Gene Set Enrichment Analysis (GSEA) of prognostic signatures was conducted with clusterprofiler. Finally, a miRNA-mRNA-transcription factor (TF) network was constructed. Results: Total 43 differential NET-related genes were obtained and two subtypes were obtained based on these genes. Patients of cluster 2 had a better prognosis compared to cluster 1. Eight types of immune cells were differential in infiltration level between two subtypes. Following univariate Cox regression analysis, two genes of CXC chemokine receptor 4 (CXCR4) and nuclear factor, erythroid 2-like 2 (NFE2L2) significantly related to patient survival were selected. GSEA of single gene revealed that CXCR4 was associated with allograft rejection and NFE2L2 was associated with drug metabolism-cytochrome P450. A network with 421 miRNA-mRNA-TF regulatory pairs was constructed. Conclusion: The present study identified two subtypes and a prognostic signature for stage I and stage II gastric cancer based on NET-related genes.

5.
BMC Pediatr ; 24(1): 61, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38243173

RESUMO

BACKGROUND: Human milk fortifier (HMF) composition has been optimized recently. But clinical evidence of its safety and efficacy is limited in Chinese population. The aim of this study was to evaluate effects of a new HMF in growth, nutritional status, feeding intolerance, and major morbidities among very preterm (VPT) or very low birth weight (VLBW) infants in China. METHODS: VPT/VLBW infants admitted from March 2020 to April 2021 were prospectively included in the experimental (new HMF, nHMF) group, who received a new powdered HMF as a breast milk feeding supplement during hospitalization. Infants in the control group (cHMF) admitted from January 2018 to December 2019, were retrospective included, and matched with nHMF group infants for gestational age and birth weight. They received other kinds of commercially available HMFs. Weight gain velocity, concentrations of nutritional biomarkers, incidence of major morbidities, and measures of feeding intolerance were compared between the two groups. RESULTS: Demographic and clinical characteristics of infants in nHMF and cHMF groups were comparable. Weight gain velocity had no significant difference between the nHMF (14.0 ± 3.5 g/kg/d) and the cHMF group (14.2 ± 3.8 g/kg/d; P = 0.46). Incidence of morbidities, including necrotizing enterocolitis, bronchopulmonary dysplasia, retinopathy of prematurity, culture-confirmed sepsis, and feeding intolerance during hospitalization between nHMF and cHMF, were similar (all P-values > 0.05). The time to achieve full enteral feeding [13.5 (10, 21) days] in the nHMF group was significantly shorter than that in the cHMF group [17 (12, 23) days, HR = 0.67, 95%CI: 0.49, 0.92; P = 0.01]. Compared with cHMF group, the decrease of blood urea nitrogen level over time in nHMF group was smaller (ß = 0.6, 95%CI:0.1, 1.0; P = 0.01). CONCLUSIONS: The new HMF can promote growth of preterm infants effectively without increasing the incidence of major morbidity and feeding intolerance. It can be used feasible in Chinese VPT/VLBW infants. TRIAL REGISTRATION: This study was registered on ClinicalTrials.gov (NCT04283799).


Assuntos
Enterocolite Necrosante , Leite Humano , Lactente , Feminino , Recém-Nascido , Humanos , Estudos Retrospectivos , Lactente Extremamente Prematuro , Alimentos Fortificados , Recém-Nascido de muito Baixo Peso , Aumento de Peso , Enterocolite Necrosante/epidemiologia , Fórmulas Infantis
6.
Nat Commun ; 15(1): 886, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38286824

RESUMO

Turbulent energy dissipation is a fundamental process in plasma physics that has not been settled. It is generally believed that the turbulent energy is dissipated at electron scales leading to electron energization in magnetized plasmas. Here, we propose a micro accelerator which could transform electrons from isotropic distribution to trapped, and then to stream (Strahl) distribution. From the MMS observations of an electron-scale coherent structure in the dayside magnetosheath, we identify an electron flux enhancement region in this structure collocated with an increase of magnetic field strength, which is also closely associated with a non-zero parallel electric field. We propose a trapping model considering a field-aligned electric potential together with the mirror force. The results are consistent with the observed electron fluxes from ~50 eV to ~200 eV. It further demonstrates that bidirectional electron jets can be formed by the hourglass-like magnetic configuration of the structure.

7.
Nanomaterials (Basel) ; 13(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37836296

RESUMO

Magnetic topological insulators (MTIs) are a group of materials that feature topological band structures with concurrent magnetism, which can offer new opportunities for technological advancements in various applications, such as spintronics and quantum computing. The combination of topology and magnetism introduces a rich spectrum of topological phases in MTIs, which can be controllably manipulated by tuning material parameters such as doping profiles, interfacial proximity effect, or external conditions such as pressure and electric field. In this paper, we first review the mainstream MTI material platforms where the quantum anomalous Hall effect can be achieved, along with other exotic topological phases in MTIs. We then focus on highlighting recent developments in modulating topological properties in MTI with finite-size limit, pressure, electric field, and magnetic proximity effect. The manipulation of topological phases in MTIs provides an exciting avenue for advancing both fundamental research and practical applications. As this field continues to develop, further investigations into the interplay between topology and magnetism in MTIs will undoubtedly pave the way for innovative breakthroughs in the fundamental understanding of topological physics as well as practical applications.

8.
Nat Commun ; 14(1): 6691, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37872165

RESUMO

Ferromagnetism and superconductivity are two key ingredients for topological superconductors, which can serve as building blocks of fault-tolerant quantum computers. Adversely, ferromagnetism and superconductivity are typically also two hostile orderings competing to align spins in different configurations, and thus making the material design and experimental implementation extremely challenging. A single material platform with concurrent ferromagnetism and superconductivity is actively pursued. In this paper, we fabricate van der Waals Josephson junctions made with iron-based superconductor Fe(Te,Se), and report the global device-level transport signatures of interfacial ferromagnetism emerging with superconducting states for the first time. Magnetic hysteresis in the junction resistance is observed only below the superconducting critical temperature, suggesting an inherent correlation between ferromagnetic and superconducting order parameters. The 0-π phase mixing in the Fraunhofer patterns pinpoints the ferromagnetism on the junction interface. More importantly, a stochastic field-free superconducting diode effect was observed in Josephson junction devices, with a significant diode efficiency up to 10%, which unambiguously confirms the spontaneous time-reversal symmetry breaking. Our work demonstrates a new way to search for topological superconductivity in iron-based superconductors for future high Tc fault-tolerant qubit implementations from a device perspective.

9.
Nano Lett ; 23(18): 8445-8453, 2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37677143

RESUMO

Tellurium (Te) is an elemental semiconductor with a simple chiral crystal structure. Te in a two-dimensional (2D) form synthesized by a solution-based method shows excellent electrical, optical, and thermal properties. In this work, the chirality of hydrothermally grown 2D Te is identified and analyzed by hot sulfuric acid etching and high-angle tilted high-resolution scanning transmission electron microscopy. The gate-tunable nonlinear electrical responses, including the nonreciprocal electrical transport in the longitudinal direction and the nonlinear planar Hall effect in the transverse direction, are observed in 2D Te under a magnetic field. Moreover, the nonlinear electrical responses have opposite signs in left- and right-handed 2D Te due to the opposite spin polarizations ensured by the chiral symmetry. The fundamental relationship between the spin-orbit coupling and the crystal symmetry in two enantiomers provides a viable platform for realizing chirality-based electronic devices by introducing the degree of freedom of chirality into electron transport.

10.
J Neurooncol ; 164(2): 367-376, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37656377

RESUMO

PURPOSE: Leptomeningeal carcinomatosis (LC) is a rare complication of non-small cell lung cancer (NSCLC) with highly mortality. Cerebrospinal fluid (CSF) as a special kind of tumor microenvironment (TME) better represents alterations than plasma. However, the clinical value of protein profiles of exosome in CSF as liquid biopsy remains unclear. METHODS: In this study, CSF samples of NSCLC patients with (LC group) or without (NSCLC group) LC were collected and compared to patients without tumors (normal group). CSF exosomes were isolated by ultracentrifugation and protein profiles were performed by label-free proteomics. Differentially expressed proteins (DEPs) were detected by bioinformatics tools and verified by parallel reaction monitoring (PRM). RESULTS: A total of 814 proteins were detected. Bioinformatics analysis revealed their shared function in the complement activation, extracellular region, and complement and coagulation cascades. Between LC and NSCLC group, 72 DEPs were found among which FN1 demonstrated the highest betweenness centrality (BC) after protein-protein interaction network analysis. CONCLUSION: We investigated the application of label free and PRM based proteomics to detect key proteins related to LC. FN1 may serve as potential indicator to classify LC and NSCLC. Extracellular matrix (ECM) and epithelial-mesenchymal transition (EMT) are important in the process of LC. These data is promising for early prediction and diagnosis of LC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinomatose Meníngea , Humanos , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Carcinomatose Meníngea/patologia , Proteômica , Biópsia Líquida , Microambiente Tumoral
11.
Cancer Cell Int ; 23(1): 107, 2023 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-37268941

RESUMO

BACKGROUND: Radiotherapy is one of the effective methods for treatment of breast cancer; however, controversies still exist with respect to radiotherapy for patients with TNBC. Here, we intend to explore the mechanism by which local radiotherapy promotes the recruitment of M-MDSCs in the lung and increases the risk of lung metastasis in TNBC tumor-bearing mice. METHODS: A single dose of 20 Gy X-ray was used to locally irradiate the primary tumor of 4T1 tumor-bearing mice. Tumor growth, the number of pulmonary metastatic nodules, and the frequency of MDSCs were monitored in the mice. Antibody microarray and ELISA methods were used to analyze the cytokines in exosomes released by irradiated (IR) or non-IR 4T1 cells. The effects of the exosomes on recruitment of MDSCs and colonization of 4T1 cells in the lung of normal BALB/c mice were observed with the methods of FCM and pathological section staining. T lymphocytes or 4T1 cells co-cultured with MDSCs were performed to demonstrate the inhibitory effect on T lymphocytes or accelerative migration effect on 4T1 cells. Finally, a series of in vitro experiments demonstrated how the exosomes promote the recruitment of M-MDSCs in lung of mice. RESULTS: Even though radiotherapy reduced the burden of primary tumors and larger lung metastatic nodules (≥ 0.4 mm2), the number of smaller metastases (< 0.4 mm2) significantly increased. Consistently, radiotherapy markedly potentiated M-MDSCs and decreased PMN-MDSCs recruitment to lung of tumor-bearing mice. Moreover, the frequency of M-MDSCs of lung was positively correlated with the number of lung metastatic nodules. Further, M-MDSCs markedly inhibited T cell function, while there was no difference between M-MDSCs and PMN-MDSCs in promoting 4T1 cell migration. X-ray irradiation promoted the release of G-CSF, GM-CSF and CXCl1-rich exosomes, and facilitated the migration of M-MDSCs and PMN-MDSCs into the lung through CXCL1/CXCR2 signaling. While irradiated mouse lung extracts or ir/4T1-exo treated macrophage culture medium showed obvious selective chemotaxis to M-MDSCs. Mechanistically, ir/4T1-exo induce macrophage to produce GM-CSF, which further promoted CCL2 release in an autocrine manner to recruit M-MDSCs via CCL2/CCR2 axis. CONCLUSIONS: Our work has identified an undesired effect of radiotherapy that may promote immunosuppressive premetastatic niches formation by recruiting M-MDSCs to lung. Further studies on radiotherapy combined CXCR2 or CCR2 signals inhibitors were necessary.

12.
Adv Mater ; 35(31): e2300391, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37207689

RESUMO

The quantum anomalous Hall (QAH) effect is characterized by a dissipationless chiral edge state with a quantized Hall resistance at zero magnetic field. Manipulating the QAH state is of great importance in both the understanding of topological quantum physics and the implementation of dissipationless electronics. Here, the QAH effect is realized in the magnetic topological insulator Cr-doped (Bi,Sb)2 Te3 (CBST) grown on an uncompensated antiferromagnetic insulator Al-doped Cr2 O3 . Through polarized neutron reflectometry (PNR), a strong exchange coupling is found between CBST and Al-Cr2 O3 surface spins fixing interfacial magnetic moments perpendicular to the film plane. The interfacial coupling results in an exchange-biased QAH effect. This study further demonstrates that the magnitude and sign of the exchange bias can be effectively controlled using a field training process to set the magnetization of the Al-Cr2 O3 layer. It demonstrates the use of the exchange bias effect to effectively manipulate the QAH state, opening new possibilities in QAH-based spintronics.

13.
Infect Drug Resist ; 16: 2075-2087, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37063936

RESUMO

Background: Enrofloxacin is a commonly used animal-specific drug in veterinary clinics. However, this drug has no epidemiological cutoff values (ECVs/ECOFFs) for Mycoplasma hyopneumoniae in CLSI and EUCAST. Defining the epidemiological cutoff values (ECOFFs) of enrofloxacine to Mycoplasma hyopneumoniae (M. hyo) can inform an early detection of bacterial resistance to better manage the resistance prevention and also help in establishing drug resistance breakpoints;. Methods: We determined the susceptibility breakpoint of M. hyo to enrofloxacin by the American Clinical and Laboratory Standards Institute (CLSI) standard method based on the PCR of vaccine strains and wild strains drug resistance genes;. Results: Eighty strains of M.hyo isolated in Tibet were moderately sensitive (S) to tetracycline, florfenicol, spiramycin, erythromycin thiocyanate, tilmicosin, tiamulin, lincomycin, clindamycin, ofloxacin, enrofloxacin, gentamicin, amikacin, with MICs below 0.5 µg/mL. For vaccine 168L, RM48, and J strains, the susceptibility to the same antibacterial drugs was lower compared to the Tibetan isolates. The resistance of J strain to erythromycin thiocyanate was confirmed. Gene point mutation was confirmed in Quinolone Resistance Determining Regions (QRDR) of HNSH strain Topoisomerase IV subunit A, this finding is compared with the sequencing results of 168L strain reference sequence (Accession number: CP003131). Arg-Lys amino acid mutation (G921A and G1179A) was confirmed for the increase of MIC value involved in M.hyo to enrofloxacine;. Conclusion: The cut-off value of M.hyo to enrofloxacin was set as 1 µg/mLby ECOFFinder XL 2010 V2.1.

14.
Eur J Pediatr ; 182(1): 353-361, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36369399

RESUMO

To investigate the risk factors for death in critically ill neonates receiving continuous renal replacement therapy (CRRT). This retrospective study analyzed the clinical data of critically ill neonates receiving CRRT at two tertiary hospitals from January 2015 to December 2021. A multi-factor logistic regression analysis was performed, and the predictive value of relevant risk factors on death was verified by receiver operating characteristic (ROC) curve. A total of 59 cases of critically ill neonates were included in this study, with a mortality of 37.3%. The most common primary disease in these cases was neonatal sepsis, followed by neonatal asphyxia, and inborn errors of metabolism (IEM). Univariate analysis showed that the risk factors related to death included primary diseases; the number of organs involved in multiple organ dysfunction syndrome (MODS), neonatal critical illness scores (NCIS), and indications of CRRT; the blood lactate, blood glucose, hemoglobin, and platelet before CRRT initiation; and the incidence of bleeding or thrombosis during CRRT. Multi-factor logistic regression analysis showed that risk factors for death in critically ill neonates receiving CRRT included the occurrence of neonatal sepsis, the number of organs involved in MODS, and the NCIS. ROC curve analysis showed that the number of organs involved in MODS and NCIS had a good predictive value for death in critically ill neonates receiving CRRT, with the areas under the curve (AUC) being 0.700 and 0.810, respectively. CONCLUSION: Neonatal sepsis, the number of organs involved in MODS, and NCIS were independent risk factors for death in critically ill neonates receiving CRRT. Moreover, the number of organs involved in MODS and NCIS could effectively predict death in critically ill neonates receiving CRRT. WHAT IS KNOWN: • The population to which CRRT is applicable is gradually expanding from critically ill children to critically ill neonates. • The mortality of critically ill neonates receiving CRRT remains high. WHAT IS NEW: • The most common primary disease in critically ill neonates receiving CRRT was neonatal sepsis, followed by neonatal asphyxia and inborn errors of metabolism (IEM). • The number of organs involved in MODS and NCIS could effectively predict death in critically ill neonates receiving CRRT.


Assuntos
Injúria Renal Aguda , Terapia de Substituição Renal Contínua , Erros Inatos do Metabolismo , Sepse Neonatal , Criança , Recém-Nascido , Humanos , Estudos Retrospectivos , Estado Terminal/terapia , Sepse Neonatal/terapia , Asfixia , Fatores de Risco , Injúria Renal Aguda/terapia
15.
Animals (Basel) ; 12(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36496925

RESUMO

BACKGROUND: Basic data concerning the gut microbiota of the main animal husbandry breeds (pigs and chickens) are scarce in China. The dynamics of gut microbiota (pigs and chickens) in China and antibiotic resistance genes carried by microorganisms in the natural environment are unknown. METHODS: Free range and factory-farmed Gushi chickens and Huainan pigs were divided into eight groups. Faecal samples were collected from each group, and the metagenomic sequencing method was used to detect each group of samples. RESULTS: The resistance genes showed the following trend, from high to low relative abundance: tetW was the highest, followed by tetW/N/W, then lnuA; and others from high to low were mdtB, lnuC, ANT6-la, ErmB, mdtC, ErmQ, tetBP, vatE, evgS, acrB, cpxA, mefA, Escherichia coli-ampC, tetL, yojl, AcrF and mdtA. All groups administered enrofloxacin and oregano oil did not develop a drug-resistant phenotype during the 5-day treatment period, as grouped in this trial. In 2022, after Announcement No. 194 of the Ministry of Agriculture and Rural Affairs in China, the antimicrobial resistance (AMR) trend declined, but it did not fundamentally change, presumably due to the impact of environmental pollution caused by the long-term use of antimicrobials.

16.
ACS Nano ; 16(10): 17336-17346, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36126321

RESUMO

In transport, the topological Hall effect (THE) presents itself as nonmonotonic features (or humps and dips) in the Hall signal and is widely interpreted as a sign of chiral spin textures, like magnetic skyrmions. However, when the anomalous Hall effect (AHE) is also present, the coexistence of two AHEs could give rise to similar artifacts, making it difficult to distinguish between genuine THE with AHE and two-component AHE. Here, we confirm genuine THE with AHE by means of transport and magneto-optical Kerr effect (MOKE) microscopy, in which magnetic skyrmions are directly observed, and find that genuine THE occurs in the transition region of the AHE. In sharp contrast, the artifact "THE" or two-component AHE occurs well beyond the saturation of the "AHE component" (under the false assumption of THE + AHE). Furthermore, we distinguish artifact "THE" from genuine THE by three methods: (1) minor loops, (2) temperature dependence, and (3) gate dependence. Minor loops of genuine THE with AHE are always within the full loop, while minor loops of the artifact "THE" may reveal a single loop that cannot fit into the "AHE component". In addition, the temperature or gate dependence of the artifact "THE" may also be accompanied by a polarity change of the "AHE component", as the nonmonotonic features vanish, while the temperature dependence of genuine THE with AHE reveals no such change. Our work may help future researchers to exercise caution and use these methods for careful examination in order to ascertain the genuine THE.

17.
J Geophys Res Space Phys ; 127(4): e2022JA030280, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35866073

RESUMO

At Mercury, several processes can release ions and neutrals out of the planet's surface. Here we present enhancements of planetary ions (Na+-group ions) in Mercury's northern magnetospheric cusp during flux transfer event (FTE) "showers." FTE showers are intervals of intense dayside magnetopause reconnection, during which FTEs are observed in quick succession, that is, only separated by a few seconds. This study identifies 1953 FTE shower intervals and 1795 Non-FTE shower intervals. During the shower intervals, this study shows that the FTEs form a solar wind entry layer equatorward of the northern magnetospheric cusp. In this entry layer, solar wind ions are accelerated and move downward (i.e., planetward) toward the cusp, which sputter upward-moving planetary ions with a particle flux of 1 × 1011 m-2 s-1 within 1 min. The precipitation rate is estimated to increase by an order of magnitude during FTE showers, to 2 × 1025 s-1, and the neutral density of the exosphere could vary by >10% in response to this FTE-driven sputtering. Such rapid large-scale variations driven by dayside reconnection may explain the minute-to-minute changes in Mercury's exosphere, especially on the high latitudes, observed by ground-based telescopes on Earth. Our MESSENGER in situ observation of enhanced planetary ions in the entry layer likely corresponds to an escape channel for Mercury's planetary ions. Comprehensive, future multipoint measurements made by BepiColombo will greatly enhance our understanding of the processes contributing to Mercury's dynamic exosphere and magnetosphere.

18.
Nat Commun ; 13(1): 4246, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35869045

RESUMO

The inelastic scattering length (Ls) is a length scale of fundamental importance in condensed matters due to the relationship between inelastic scattering and quantum dephasing. In quantum anomalous Hall (QAH) materials, the mesoscopic length scale Ls plays an instrumental role in determining transport properties. Here we examine Ls in three regimes of the QAH system with distinct transport behaviors: the QAH, quantum critical, and insulating regimes. Although the resistance changes by five orders of magnitude when tuning between these distinct electronic phases, scaling analyses indicate a universal Ls among all regimes. Finally, mesoscopic scaled devices with sizes on the order of Ls were fabricated, enabling the direct detection of the value of Ls in QAH samples. Our results unveil the fundamental length scale that governs the transport behavior of QAH materials.

19.
Phys Rev Lett ; 128(21): 217704, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35687463

RESUMO

The quantum anomalous Hall (QAH) effect has been demonstrated in two-dimensional topological insulator systems incorporated with ferromagnetism. However, a comprehensive understanding of mesoscopic transport in submicron QAH devices has not yet been established. Here we fabricated miniaturized QAH devices with channel widths down to 600 nm, where the QAH features are still preserved. A backscattering channel is formed in narrow QAH devices through percolative hopping between 2D compressible puddles. Large resistance fluctuations are observed in narrow devices near the coercive field, which is associated with collective interference between intersecting paths along domain walls when the device geometry is smaller than the phase coherence length L_{ϕ}. Through measurement of size-dependent breakdown current, we confirmed that the chiral edge states are confined at the physical boundary with its width on the order of Fermi wavelength.

20.
Clin Kidney J ; 15(2): 320-327, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35145646

RESUMO

BACKGROUND: In recent years, the incidence of wasp sting has increased annually in China. Organ damage and high mortality due to mass wasp envenomation remain major challenges. Timely and appropriate medical intervention can improve survival. However, there are currently no normalized tools for early assessment of severity. METHODS: The clinical data of wasp sting patients hospitalized from 2011 to 2019 were used as a training set. Logistic regression was used to explore major risk factors for the development of a severe case of wasp sting (SC). The Wasp Sting Severity Score (WSS) was determined considering these risk factors to identify SCs and was tested in a validation dataset that was prospectively collected in 2020. RESULTS: The data of 1131 wasp sting patients from 2011 to 2019 were included in the training set. Logistic regression analysis showed that tea-colored urine, number of stings, and lactate dehydrogenase and total bilirubin levels were risk factors for developing an SC. The WSS was developed considering these four risk factors, and the total possible WSS was 20 points. The WSS was tested using the validation dataset, comprising the data of 153 patients, in 2020, and we found that a WSS ≥3 points was an important indication for blood purification, with a sensitivity of 71.9%, specificity of 92.6% and an area under the curve of 0.918 (95% confidence interval 0.873-0.962). Among patients with more than 30 stings, mortality in those who underwent plasma exchange (PE) within 24 h after admission was significantly lower than that in those who did not receive PE treatment (14.3% versus 46.9%, P = 0.003). However, continuous venovenous hemofiltration (CVVH) (P = 0.317) and hemoperfusion (HP) (P = 0.869) did not significantly reduce mortality. CONCLUSIONS: Patients with WSS scores ≥3 should be considered for blood purification as early as possible in addition to routine treatment. In addition, PE is better than CVVH and HP at reducing mortality in patients suffering from severe wasp stings.

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