7 research outputs found
Data_Sheet_1_Thrombectomy with and without computed tomography perfusion imaging for large-vessel occlusion stroke in the extended time window: a meta-analysis of randomized clinical trials.docx
ObjectiveIn recent years, several studies have used computed tomography perfusion (CTP) to assess whether mechanical thrombectomy can be performed in patients with large-vessel occlusion (LVO) stroke in an extended time window. However, it has the disadvantage of being time-consuming and expensive. This study aimed to compare the impact of the CTP group with the non-CTP group [non-contrast CT (NCCT) ± CT angiography (CTA)] on the prognosis of this patient population.MethodsA search of PubMed, EMBASE, and the Cochrane Library databases was conducted to collect randomized controlled trials (RCTs) comparing the two strategies. Outcome indicators and factors influencing prognosis were summarized by standardized mean differences, ratios, and relative risks with 95% confidence intervals using a random-effects model.ResultsA total of two RCTs were included in the combined analysis. There were no significant differences in the main outcome indicators (modified Rankin Scale score at 90 days, successful postoperative reperfusion rate) or the incidence of adverse events (90-day mortality and symptomatic intracranial hemorrhage) between the NCCT ± CTA and CTP groups. The time from the last puncture appeared to be significantly shorter in the NCCT ± CTA group than in the CTP group (SMD: −0.14; 95% CI: −0.24, −0.04). Among them, age (OR: 0.96; 95% CI: 0.94, 0.98), ASPECTS (OR: 1.18; 95% CI: 1.12, 1.24), NIHSS score (OR: 0.90; 95% CI: 0.89, 0.91), and diabetes (OR: 0.69; 95% CI: 0.54, 0.88) were associated with a 90-day independent functional outcome.ConclusionThese findings suggest that the choice of NCCT ± CTA (without CTP) for the assessment of mechanical thrombectomy within 6–24 h after LVO in the anterior circulation is not significantly different from CTP; instead, the choice of NCCT ± CTA significantly reduces the time from onset to arterial puncture.</p
Nanostructured Cu-Al2O3 Composite Produced by Citric Acid Sol-Gel Method
Nanostructured Cu-Al2O3 Composite Produced by Citric Acid Sol-Gel Metho
A graphical multi-fidelity Gaussian process model, with application to emulation of heavy-ion collisions
With advances in scientific computing and mathematical modeling, complex scientific phenomena such as galaxy formations and rocket propulsion can now be reliably simulated. Such simulations can however be very time-intensive, requiring millions of CPU hours to perform. One solution is multi-fidelity emulation, which uses data of different fidelities to train an efficient predictive model which emulates the expensive simulator. For complex scientific problems and with careful elicitation from scientists, such multi-fidelity data may often be linked by a directed acyclic graph (DAG) representing its scientific model dependencies. We thus propose a new Graphical Multi-fidelity Gaussian Process (GMGP) model, which embeds this DAG structure (capturing scientific dependencies) within a Gaussian process framework. We show that the GMGP has desirable modeling traits via two Markov properties, and admits a scalable algorithm for recursive computation of the posterior mean and variance along at each depth level of the DAG. We also present a novel experimental design methodology over the DAG given an experimental budget, and propose a nonlinear extension of the GMGP via deep Gaussian processes. The advantages of the GMGP are then demonstrated via a suite of numerical experiments and an application to emulation of heavy-ion collisions, which can be used to study the conditions of matter in the Universe shortly after the Big Bang. The proposed model has broader uses in data fusion applications with graphical structure, which we further discuss.</p
DataSheet_1_Integrated nontargeted and targeted metabolomics analyses amino acids metabolism in infantile hemangioma.zip
Infantile hemangioma (IH) is the most common benign tumor in children. However, the exact pathogenesis of IH remains unclear. Integrated nontargeted and targeted metabolic analyses were performed to obtain insight into the possible pathogenic mechanism of IH. The results of nontargeted metabolic analysis showed that 216 and 128 differential metabolites (DMs) were identified between hemangioma-derived endothelial cells (HemECs) and HUVECs in positive-ion and negative-ion models, respectively. In both models, these DMs were predominantly enriched in pathways related to amino acid metabolism, including aminoacyl-tRNA biosynthesis and arginine and proline metabolism. Then, targeted metabolic analysis of amino acids was further performed to further clarify HemEC metabolism. A total of 22 amino acid metabolites were identified, among which only 16 metabolites, including glutamine, arginine and asparagine, were significantly differentially expressed between HemECs and HUVECs. These significant amino acids were significantly enriched in 10 metabolic pathways, including ‘alanine, aspartate and glutamate metabolism’, ‘arginine biosynthesis’, ‘arginine and proline metabolism’, and ‘glycine, serine and threonine metabolism’. The results of our study revealed that amino acid metabolism is involved in IH. Key differential amino acid metabolites, including glutamine, asparagine and arginine, may play an important role in regulating HemEC metabolism.</p
Untangling Framework Confinements: A Dynamical Study on Bulky Aromatic Molecules in MFI Zeolites
In MFI zeolites, differentiating the molecular dynamics
as a function
of pore structures, that is, straight-channel versus zigzag-channel
versus channel-intersection, has always been challenging, mainly due
to small differences in pore size but is of great interest because
these subtle structural differences can remarkably influence shape
selectivity. Herein, 1,2,4-trimethyl benzene (1,2,4-TMB), a characteristic
molecule larger than the 10-MR channel diameter, while smaller than
the channel intersection, is chosen to probe the pore-confined dynamical
behaviors in MFI via 2H NMR spectroscopy and density functional
theory calculations. Our results show that in the absence of acid
sites, that is, in the siliceous MFI silicalite-1, 1,2,4-TMBs can
only diffuse along the straight channels; while at equilibrium, they
incline to occupy the channel intersections with structure-defined
orientations. Furthermore, a series of dynamic motions of 1,2,4-TMBs
under different types of pore confinements are revealed and evaluated
at a molecular level over a wide range of timescales, concluded, in
short, as methyl C3-rotation > 112°-flip
> 90°-flip > translational diffusion. With the presence
of acid
sites, that is, in H-ZSM-5; however, 1,2,4-TMBs are strongly adsorbed
on Brønsted acid sites and the confined motions are further impeded.
The findings in this work may provide insights to the catalytic roles
of polymethyl-benzene intermediates, including 1,2,4-TMB, which usually
serve as active centers or deactivation precursors in zeolite-based
hydrocarbon conversion processes
Evidence of Ferromagnetism and Ultrafast Dynamics of Demagnetization in an Epitaxial FeCl<sub>2</sub> Monolayer
The development of two-dimensional (2D) magnetism is
driven not
only by the interest of low-dimensional physics but also by potential
applications in high-density miniaturized spintronic devices. However,
2D materials possessing a ferromagnetic order with a relatively high
Curie temperature (Tc) are rare. In this
paper, the evidence of ferromagnetism in monolayer FeCl2 on Au(111) surfaces, as well as the interlayer antiferromagnetic
coupling of bilayer FeCl2, is characterized by using spin-polarized
scanning tunneling microscopy. A Curie temperature (Tc) of ∼147 K is revealed for monolayer FeCl2, based on our static magneto-optical Kerr effect measurements.
Furthermore, temperature-dependent magnetization dynamics is investigated
by the time-resolved magneto-optical Kerr effect. A transition from
one- to two-step demagnetization occurs as the lattice temperature
approaches Tc, which supports the Elliott–Yafet
spin relaxation mechanism. The findings contribute to a deeper understanding
of the underlying mechanisms governing ultrafast magnetization in
2D ferromagnetic materials