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1.
Angew Chem Int Ed Engl ; 62(48): e202311348, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37828622

RESUMO

Flexible crystals that can capture solar energy and convert it into mechanical energy are promising for a wide range of applications such as information storage and actuators, but obtaining them remains a challenge. Herein, an elastic crystal of a barbiturate derivative was found to be an excellent candidate, demonstrating plastic bending behavior under natural sunlight irradiation. 1 H NMR and high-resolution mass spectrum data of microcrystals before and after light irradiation demonstrated that light-induced [2+2] cycloaddition was the driving force for the photomechanical effects. Interestingly, the crystals retained elastic bending even after light irradiation. This is the first report of flexible crystals that can be driven by natural sunlight and that have both photomechanical properties and elasticity. Furthermore, regulation of the passive light output direction of the crystals and transport of objects by applying mechanical forces and light was demonstrated.

2.
IEEE Trans Pattern Anal Mach Intell ; 45(6): 7319-7337, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36355744

RESUMO

Person search aims at localizing and recognizing query persons from raw video frames, which is a combination of two sub-tasks, i.e., pedestrian detection and person re-identification. The dominant fashion is termed as the one-step person search that jointly optimizes detection and identification in a unified network, exhibiting higher efficiency. However, there remain major challenges: (i) conflicting objectives of multiple sub-tasks under the shared feature space, (ii) inconsistent memory bank caused by the limited batch size, (iii) underutilized unlabeled identities during the identification learning. To address these issues, we develop an enhanced decoupled and memory-reinforced network (DMRNet++). First, we simplify the standard tightly coupled pipelines and establish a task-decoupled framework (TDF). Second, we build a memory-reinforced mechanism (MRM), with a slow-moving average of the network to better encode the consistency of the memorized features. Third, considering the potential of unlabeled samples, we model the recognition process as semi-supervised learning. An unlabeled-aided contrastive loss (UCL) is developed to boost the identification feature learning by exploiting the aggregation of unlabeled identities. Experimentally, the proposed DMRNet++ obtains the mAP of 94.5% and 52.1% on CUHK-SYSU and PRW datasets, which exceeds most existing methods.

3.
Bioorg Med Chem Lett ; 72: 128844, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35697180

RESUMO

Oxidative stress and inflammation were considered to be the major mechanisms in liver damage caused by clofibrate (CF). In order to obtain lipid-lowering drugs with less liver damage, the structure of clofibrate was optimized by O-desmethyl anetholtrithione and got the target compound clofibrate-O-desmethyl anetholtrithione (CF-ATT). CF-ATT significantly reduced the levels of plasma triglycerides (TG), total cholesterol (TC) in hyperlipidemia mice induced by Triton WR-1339. In addition, CF-ATT has a significantly protective effect on the liver compared with CF. The liver weight and liver coefficient were reduced. The hepatic function indexes were also decreased, such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). Histopathological examination of the liver revealed that inflammatory cell infiltration, nuclear degeneration, cytoplasmic loosening and hepatocyte necrosis were ameliorated by administration with CF-ATT. The hepatoprotective mechanism showed that CF-ATT significantly up-regulated Nrf2 and HO-1 protein expression and down-regulated p-NF-κB P65 expression in the liver. CF-ATT has obviously antioxidant and anti-inflammatory activity. These findings suggested that CF-ATT has significant hypolipidemia activity and exact hepatoprotective effect possibly through the Nrf2/NF-κB-mediated signal pathway.


Assuntos
Anetol Tritiona , Doença Hepática Induzida por Substâncias e Drogas , Hepatopatias , Anetol Tritiona/metabolismo , Anetol Tritiona/farmacologia , Animais , Antioxidantes/farmacologia , Aspartato Aminotransferases , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Clofibrato/farmacologia , Fígado/metabolismo , Hepatopatias/patologia , Camundongos , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo
4.
Chem Commun (Camb) ; 56(23): 3405-3408, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32091059

RESUMO

We have developed a unique approach for the thermally promoted cycloaddition of cyclohexadienone-tethered allenes to form a versatile cyclobutane-fused oxygen-containing tricyclic framework in an environmentally friendly and atomic economic fashion with high regioselectivity. The reaction encompasses a broad substrate scope and functional group tolerance of cyclohexadienone moieties. Moreover, the cycloaddition was also applicable to the late-stage functionalization of pharmaceutically relevant compounds.

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