To investigate the predictive value of T2 star-weighted angiography (SWAN) combined with 3-dimensional (3D) arterial spin labeling (3D-ASL) to assess cerebral perfusion status and clinical prognosis in chronic unilateral middle cerebral artery (MCA) M1 occlusion. This study included 55 patients diagnosed with chronic unilateral MCA M1 occlusion using 3D time-of-flight magnetic resonance angiography between January 2018 and July 2022. Based on the prominent vessel sign (PVS) shown in the SWAN sequence, the patients were divided into PVS-positive (n = 26) and PVS-negative (n = 29) groups.
View Article and Find Full Text PDFObjective: To explore the value of three-dimensional- (3D-) arterial spin labeling (ASL) technique in evaluating cerebral perfusion in patients with unilateral middle cerebral artery occlusion (MCAO) and to observe the influencing factors of poor prognosis via long-term follow-up of patients who survived the disease.
Methods: The clinical data of 60 patients with unilateral middle cerebral artery (MCA) M1 segment occlusion diagnosed by magnetic resonance angiography (MRA) from January 2018 to January 2022 were retrospectively analyzed. All patients were examined by routine MRI, MRA, and 3D-ASL, in which two postlabeling delays (PLDs; 1525 ms and 2525 ms) were used in 3D-ASL.
Controllably tuning redox performance is one of the key targets in catalysis. Doping is one of the widely used methods to tune the performance of nanoparticles. However, the influence of dopants is generally focused on the effects of the dopant sites or nearby sites without considering the bulk distortion.
View Article and Find Full Text PDFEnviron Sci Technol
April 2016
MOx/ABO3 is a promising catalyst for the high-efficiency removal of volatile organic compounds. However, this catalyst is limited on practical applications due to its complex synthesis procedure and high cost. In this work, the MnO2/LaMnO3 catalyst was prepared in situ using a facile one-step method for the first time, in which partial La cations were selectively removed from three dimensionally chain-like ordered macroporous (3DOM) LaMnO3 material.
View Article and Find Full Text PDFControlling chemical reactions on surface is of great importance to constructing self-assembled covalent nanostructures. Herein, Knoevenagel reaction between aromatic aldehyde compound 2,5-di(5-aldehyde-2-thienyl)-1,4-dioctyloxybenzene (PT2) and barbituric acid (BA) has been successfully performed for the first time at liquid/HOPG interface and vapor/HOPG interface. The resulting surface nanostructures and the formation of C═C bond are recorded through scanning tunneling microscopy (STM), and confirmed by attenuated total reflectance Fourier-transform infrared (ATR/FT-IR) spectrometer and UV-vis absorption.
View Article and Find Full Text PDFPhys Chem Chem Phys
December 2014
Efficient photochemical reactions on a surface are of great importance for their potential applications in optoelectronic devices. In this work, a highly efficient photodimerization reaction of an olefin cocrystal built from two trans-1,2-bis(4-pyridyl)ethylenes (4,4'-bpe) and two isophthalic acid molecules via N···H-O hydrogen bonds in between was achieved in a nanotemplate on a highly oriented pyrolytic graphite (HOPG) surface. 4,4'-Bpe molecules first undergo the trans-cis isomerization followed by [2+2] photodimerization in the nanotemplate on HOPG upon UV irradiation.
View Article and Find Full Text PDFThe self-assembling behaviour of two kinds of 4-carboxyphenoxy phthalocyanines (Pc1 and Pc2) has been investigated by scanning tunneling microscope (STM). Pc1 and Pc2 are isomers with the same substituent at alpha- andbeta-position of the phthalocyanine core, respectively. Our STM results have shown that the Pc1 molecule fabricates into stable networks with nanoscale cavities, while Pc2 forms an unstable linear-like structure at the 1-heptanoic acid/graphite interface.
View Article and Find Full Text PDFA promising approach to create functional nanoarrays is supramolecular self-assembly at liquid-solid interfaces. In the present investigation, we report on the self-assembly of phthalocyanine arrays using triphenylene-2,6,10-tricarboxylic acid (H₃TTCA) as a molecular nanotemplate. Five different metastable arrays are achieved in the study, including a thermodynamically stable configuration.
View Article and Find Full Text PDFSurface reactivity has become one of the most important issues in surface chemistry over the past few years. In this work, we, for the first time, have investigated the homo-coupling of a special terminal alkyne derivative on the highly oriented pyrolitic graphite (HOPG) surface. Using scanning tunneling microscopy (STM) technique, we have found that such coupling reaction seriously depends on the supramolecular assembly of the monomer on the studied substrate, whereas the latter appears an obvious solvent effect.
View Article and Find Full Text PDFNanoscaled two-dimensional (2D) chiral architectures are increasingly receiving scientific interest, because of their potential applications in many domains. In this paper, we present a new method for constructing 2D chiral architectures on surface. Based on in situ Schiff-base reaction of achiral dialdehyde with two types of achiral amines at the solid/liquid interface, two chiral species have been directly formed and confirmed by means of a scanning tunneling microscopy (STM) technique.
View Article and Find Full Text PDFA straightforward, efficient, and more sustainable copper-catalyzed method has been developed for intramolecular N-arylation providing the benzimidazole ring system. With Cu(2)O (5 mol %) as the catalyst, DMEDA (10 mol %) as the ligand, and K(2)CO(3) as the base, this protocol was applied to synthesize a small library of benzimidazoles in high yields. Remarkably, the reaction was exclusively carried out in water, rendering the methodology highly valuable from both environmental and economical points of view.
View Article and Find Full Text PDF