Chronic carotid artery occlusion remains a poorly understood risk factor for subsequent stroke, and potential revascularization is dependent on understanding the anatomy and nature of the occlusion. ...Luminal imaging cannot assess the nature of an occlusion, so the internal structure of the occlusion must be inferred. The present study examines the signal characteristics of symptomatic and asymptomatic carotid occlusion that may point to management differentiation.
We prospectively recruited patients who were diagnosed with chronic carotid artery occlusion defined as longer than 4 weeks and confirmed by DSA. All patients underwent high-resolution MR vessel wall imaging examinations after enrollment. Baseline characteristics, vessel wall imaging features, and DSA features were collected and evaluated. The vessel wall imaging features included segment involvement, signal intensity, contrast enhancement, and vessel wall thickness. The symptomatic and asymptomatic chronic carotid artery occlusions were compared.
A total of 44 patients with 48 lesions were included in this study from February 2020 to December 2020. Of the 48 lesions, 35 (72.9%) were symptomatic and 13 (27.1%) were asymptomatic. There was no difference in baseline and DSA features. On vessel wall imaging, C1 and C2 were the most commonly involved segments (91.7% and 68.8%, respectively). Compared with symptomatic lesions, asymptomatic lesions were more often isointense (69.2%) in the distal segment (
= .03). Both groups had diffuse wall thickening (80% and 100%).
Signal characteristics between those with symptomatic and asymptomatic carotid artery occlusions differ in a statistically significant fashion, indicating a different structure of the occlusion.
Fires, including wildfires, harm air quality and essential public services like transportation, communication, and utilities. These fires can also influence atmospheric conditions, including ...temperature and aerosols, potentially affecting severe convective storms. Here, we investigate the remote impacts of fires in the western United States (WUS) on the occurrence of large hail (size: ⩾ 2.54 cm) in the central US (CUS) over the 20-year period of 2001–20 using the machine learning (ML), Random Forest (RF), and Extreme Gradient Boosting (XGB) methods. The developed RF and XGB models demonstrate high accuracy (> 90%) and F1 scores of up to 0.78 in predicting large hail occurrences when WUS fires and CUS hailstorms coincide, particularly in four states (Wyoming, South Dakota, Nebraska, and Kansas). The key contributing variables identified from both ML models include the meteorological variables in the fire region (temperature and moisture), the westerly wind over the plume transport path, and the fire features (i.e., the maximum fire power and burned area). The results confirm a linkage between WUS fires and severe weather in the CUS, corroborating the findings of our previous modeling study conducted on case simulations with a detailed physics model.
Abstract
We report experimental observation of large anomalous Hall effect exhibited in non-collinear triangular antiferromagnet D0
19
-type Mn
3
Ga with coplanar spin structure at temperatures ...higher than 100 K. The value of anomalous Hall resistivity increases with increasing temperature, which reaches 1.25 μΩ · cm at a low field of ~300 Oe at room temperature. The corresponding room-temperature anomalous Hall conductivity is about 17 (Ω · cm)
−1
. Most interestingly, as temperature falls below 100 K, a temperature-independent topological-like Hall effect was observed. The maximum peak value of topological Hall resistivity is about 0.255 μΩ · cm. The appearance of the topological Hall effect is attributed to the change of spin texture as a result of weak structural distortion from hexagonal to orthorhombic symmetry in Mn
3
Ga. Present study suggests that Mn
3
Ga shows promising possibility to be antiferromagnetic spintronics or topological Hall effect-based data storage devices.
Flexible all-solid-state supercapacitors (SCs) have great potential applications in flexible and wearable electronics because of their safety, high power density, flexibility, and portability. ...Herein, a self-supported film electrode comprising nitrogen-doped reduced graphene oxide intertwined with vanadium trioxide nanoflakes (V
2
O
3
/N-rGO) was fabricated. The V
2
O
3
nanoflakes have abundant active sites accessible to charge storage, and nitrogen-doped reduced graphene oxide provides a flexible support. The V
2
O
3
/N-rGO film electrodes exhibit high conductivity, short diffusion length for ions and electrons, and robust flexibility, resulting in excellent capacitive properties and flexibility. The flexible V
2
O
3
/N-rGO film electrode has a high areal capacitance of 216 mF cm
−2
at a current density of 1 mA cm
−2
. All-solid-state flexible SCs assembled by sandwiching two self-supported V
2
O
3
/N-rGO hybrid electrodes with alkaline poly(vinyl alcohol) (PVA) and LiCl gel electrolyte show an ideal volumetric capacitance of 8.1 F cm
−3
, an energy density of 0.55 mW h cm
−3
, and a power density of 0.035 W cm
−3
at a current density of 0.1 A cm
−3
, based on the entire cell. This indicates that the self-supported V
2
O
3
/N-rGO film electrodes have great potential applications in portable and wearable flexible electronics due to their high capacitance, high energy/power density, and good mechanical flexibility.
Flexible all-solid-state supercapacitors (SCs) have great potential applications in flexible and wearable electronics because of their safety, high power density, flexibility, and portability.
Dendritic cells (DCs) comprise distinct functional subsets including CD8
− and CD8
+ classical DCs (cDCs) and interferon-secreting plasmacytoid DCs (pDCs). The cytokine Flt3 ligand (Flt3L) controls ...the development of DCs and is particularly important for the pDC and CD8
+ cDC and their CD103
+ tissue counterparts. We report that mammalian target of rapamycin (mTOR) inhibitor rapamycin impaired Flt3L-driven DC development in vitro, with the pDCs and CD8
+-like cDCs most profoundly affected. Conversely, deletion of the phosphoinositide 3-kinase (PI3K)-mTOR negative regulator Pten facilitated Flt3L-driven DC development in culture. DC-specific Pten targeting in vivo caused the expansion of CD8
+ and CD103
+ cDC numbers, which was reversible by rapamycin. The increased CD8
+ cDC numbers caused by Pten deletion correlated with increased susceptibility to the intracellular pathogen Listeria. Thus, PI3K-mTOR signaling downstream of Flt3L controls DC development, and its restriction by Pten ensures optimal DC pool size and subset composition.
► Flt3L induces mammalian target of rapamycin (mTOR) signaling in dendritic cells (DCs) ► Flt3L-driven DC development is impaired by rapamycin and accelerated by Pten deletion ► DC-specific deletion of Pten causes mTOR-dependent expansion of CD8
+ DC numbers ► DC-specific deletion of Pten impairs immunity to Listeria infection
Plasmacytoid dendritic cells (pDCs) are primary producers of type I interferon (IFN) in response to viruses. The IFN-producing capacity of pDCs is regulated by specific inhibitory receptors, yet none ...of the known receptors are conserved in evolution. We report that within the human immune system, receptor protein tyrosine phosphatase sigma (PTPRS) is expressed specifically on pDCs. Surface PTPRS was rapidly downregulated after pDC activation, and only PTPRS− pDCs produced IFN-α. Antibody-mediated PTPRS crosslinking inhibited pDC activation, whereas PTPRS knockdown enhanced IFN response in a pDC cell line. Similarly, murine Ptprs and the homologous receptor phosphatase Ptprf were specifically co-expressed in murine pDCs. Haplodeficiency or DC-specific deletion of Ptprs on Ptprf-deficient background were associated with enhanced IFN response of pDCs, leukocyte infiltration in the intestine and mild colitis. Thus, PTPRS represents an evolutionarily conserved pDC-specific inhibitory receptor, and is required to prevent spontaneous IFN production and immune-mediated intestinal inflammation.
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•Human pDCs specifically express receptor protein tyrosine phosphatase PTPRS•Murine pDCs specifically express Ptprs and the homologous phosphatase Ptprf•Ptprs inhibits interferon production by murine and human pDCs•Combined loss of Ptprs and Ptprf cause pDC hyperactivation and mild colitis
Plasmacytoid dendritic cells (pDCs) express unique receptors that inhibit their interferon-producing capacity, yet none of the known receptors are conserved in evolution. Reizis and colleagues identify protein tyrosine phosphatase sigma (PTPRS) as an inhibitory receptor on human and murine pDCs that prevents pDC hyperactivation and intestinal inflammation.
Stem cells (SC) exhibit a unique capacity for self-renewal in an undifferentiated state. It is unclear whether the self-renewal of pluripotent embryonic SC (ESC) and of tissue-specific adult SC such ...as hematopoietic SC (HSC) is controlled by common mechanisms. The deletion of transcription factor Zfx impaired the self-renewal but not the differentiation capacity of murine ESC; conversely, Zfx overexpression facilitated ESC self-renewal by opposing differentiation. Furthermore, Zfx deletion abolished the maintenance of adult HSC but did not affect erythromyeloid progenitors or fetal HSC. Zfx-deficient ESC and HSC showed increased apoptosis and SC-specific upregulation of stress-inducible genes. Zfx directly activated common target genes in ESC and HSC, as well as ESC-specific target genes including ESC self-renewal regulators Tbx3 and Tcl1. These studies identify Zfx as a shared transcriptional regulator of ESC and HSC, suggesting a common genetic basis of self-renewal in embryonic and adult SC.
Abstract
A theoretical study on the interplay of frustrated skyrmion and magnons should reveal new physics and future experiment designs. In this study, we investigate the magnon-driven dynamics of ...frustrated skyrmion in synthetic antiferromagnets based on micromagnetic simulations, focusing on the effect of skyrmion helicity oscillation. The oscillation speed and Hall angle of the frustrated skyrmion depending on the magnon intensity and damping constant are simulated, which demonstrates that the skyrmion helicity oscillation effectively suppresses Hall motion. The elastic scattering theory reveals that the helicity oscillation affects the scattering cross-section of injected magnons, which in turn effectively modulates the skyrmion Hall motion. This study provides a comprehensive understanding of magnon-skyrmion scattering in frustrated magnets, thus benefiting future spintronic and magnonic applications.
This paper focuses on the effects of hindered phenolic antioxidants AO300 and AO736 with similar molecular structure on the electrical properties of isotactic polypropylene (iPP). Experiments of ...conductivity, space charge distribution, and DC breakdown strength after the hetero-polarity DC prestress are performed. The experimental results show that these two antioxidants can increase the conductivity-temperature coefficient, reduce the accumulation of space charge and improve the DC breakdown strength after the hetero-polarity DC prestress of iPP. By calculating the molecular orbitals of these two antioxidants, it is found that the antioxidants introduce local states in the forbidden band of iPP matrix to capture high-energy charges. Besides, the bond dissociation energy (BDE) of the hydrogen-oxygen bond in AO736 is lower than that in AO300, representing a stronger ability of proton transfer, which scavenges the radicals, inhibits the growth of microvoids and prevents the process of breakdown. It is concluded that the improvement of space charge and breakdown properties is attributed to the coupling effects of deep trap sites and radicals scavenging introduced by antioxidant. This research shows that AO736 has potential applications in PP insulation.
To understand the effect of topological defects on the Li adsorption on graphene, we have performed first-principles calculations to study the adsorption and diffusion of a lithium adatom on graphene ...with (5, 0)|(3, 3), (2, 1)|(2, 1), and (2, 0)|(2, 0) grain boundaries (GBs). Our results show that the adsorption of a Li adatom on defect-free graphene is endothermic with respect to the bulk Li and the adsorption of a Li adatom on the GBs of graphene is exothermic. In particular, the presence of a (2, 0)|(2, 0) GB leads to a decrease of about 0.92 eV in the adsorption energy of a Li adatom on graphene. This suggests that GBs would significantly enhance the Li adsorption on graphene. In three cases of GBs, the energy barrier for the diffusion of a Li adatom along the boundary is lower than that perpendicular to the boundary, indicating that a Li adatom tends to diffuse along the boundary and to migrate from nonboundary sites toward the boundary zone. The difference charge density and the Bader charge analysis both show there is a significant charge transfer from the Li adatom to its nearest neighboring carbon atoms.
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