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1.
Nano Lett ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38647318

RESUMO

The discovery of room-temperature ferromagnetism in van der Waals (vdW) materials opens new avenues for exploring low-dimensional magnetism and its applications in spintronics. Recently, the observation of the room-temperature topological Hall effect in the vdW ferromagnet Fe3GaTe2 suggests the possible existence of room-temperature skyrmions, yet skyrmions have not been directly observed. In this study, real-space imaging was employed to investigate the domain evolution of the labyrinth and skyrmion structure. First, Néel-type skyrmions can be created at room temperature. In addition, the influence of flake thickness and external magnetic field (during field cooling) on both labyrinth domains and the skyrmion lattice is unveiled. Due to the competition between magnetic anisotropy and dipole interactions, the specimen thickness significantly influences the density of skyrmions. These findings demonstrate that Fe3GaTe2 can host room-temperature skyrmions of various sizes, opening up avenues for further study of magnetic topological textures at room temperature.

2.
Food Chem X ; 21: 101128, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38292671

RESUMO

Thirteen kojic acid-coumarin derivatives were synthesized using the principle of molecular hybridization, and their structures were characterized by 1H NMR, 13C NMR, and HRMS. In vitro enzyme inhibition experiments showed that all newly synthesized derivatives have excellent inhibition of tyrosinase (TYR) activity. As a mixed inhibitor, compound 6f has the strongest activity, with an IC50 value of 0.88 ± 0.10 µM. Multispectral experiments have confirmed that the mode of action of compound 6f on TYR was static quenching. In addition, compound 6f formed a new complex with TYR, which increased the hydrophobicity of the enzyme microenvironment, reduced the content of the α-helix in the enzyme, and changed the secondary structure. The experimental results showed that compound 6f effectively inhibited the browning of lotus root slices and had low cytotoxicity. Therefore, compound 6f is believed to have great development potential as a TYR inhibitor in the food industry.

3.
Int J Environ Health Res ; 34(2): 943-955, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36919640

RESUMO

Few studies have investigated the association between PM2.5 and hypertension among floating populations. We therefore examined the relationship using binary logistic regression. Each grade of increment in the annual average PM2.5 (grade one: ≤15 µg/m3; grade two: 15-25 µg/m3; grade three: 25-35 µg/m3 [Excluding 25]; grade four: ≥35 µg/m3) was associated with an increased risk of hypertension (odds ratio [OR] = 1.081, 95% confidence interval (CI): 1.034-1.129). Among the female floating population (OR = 1.114, 95% CI: 1.030-1.204), those with education level of primary school and below (OR = 1.140, 95% CI: 1.058-1.229), construction workers (OR = 1.228, 95% CI: 1.058-1.426), and those living in the eastern region of China (OR = 1.241, 95% CI: 1.145-1.346) were more vulnerable to PM2.5. These results indicate that PM2.5 is positively associated with hypertension in floating populations. Floating populations who are female, less educated, construction workers, and living in the eastern region of China are more vulnerable to the adverse impacts of PM2.5.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Hipertensão , Humanos , Feminino , Masculino , Material Particulado/toxicidade , Material Particulado/análise , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Estudos Transversais , Hipertensão/epidemiologia , Hipertensão/etiologia , China/epidemiologia , Exposição Ambiental
4.
Int J Environ Health Res ; 34(2): 1124-1135, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37092899

RESUMO

There are limited studies investigating the association between short-term exposure to PM2.5 and incident cardiovascular disease (CVD) cases in China. This study aims to examine the short-term effects of PM2.5 on the incidence of cardiovascular diseases. A combination of Poisson-distribution generalized linear model and distributed lag non-linear model was used to examine the association between short-term exposure to PM2.5 and incident cases of CVD. The results revealed that per 10 µg/m3 increment of PM2.5 would increase the incident CVD cases by 0.147% (Relative Risk: 1.00147, 95% Confidence Interval: 1.00008-1.00286) at a lag of 2 days. The stratified analyses showed higher effects risk in females, older residents (aged 60-75 years), and acute myocardial infarction group (p-value for difference <0.05). This study indicates that short-term exposure to PM2.5 may increase the risk of CVD and highlights the necessity for a higher air quality standard in Yantai, China.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Doenças Cardiovasculares , Feminino , Humanos , Poluentes Atmosféricos/toxicidade , Poluentes Atmosféricos/análise , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/epidemiologia , Material Particulado/toxicidade , Material Particulado/análise , Exposição Ambiental/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China/epidemiologia
5.
IEEE Trans Image Process ; 33: 322-337, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38100338

RESUMO

Depth image-based rendering (DIBR) techniques play an essential role in free-viewpoint videos (FVVs), which generate the virtual views from a reference 2D texture video and its associated depth information. However, the background regions occluded by the foreground in the reference view will be exposed in the synthesized view, resulting in obvious irregular holes in the synthesized view. To this end, this paper proposes a novel coarse and fine-grained fusion hierarchical network (CFFHNet) for hole filling, which fills the irregular holes produced by view synthesis using the spatial contextual correlations between the visible and hole regions. CFFHNet adopts recurrent calculation to learn the spatial contextual correlation, while the hierarchical structure and attention mechanism are introduced to guide the fine-grained fusion of cross-scale contextual features. To promote texture generation while maintaining fidelity, we equip CFFHNet with a two-stage framework involving an inference sub-network to generate the coarse synthetic result and a refinement sub-network for refinement. Meanwhile, to make the learned hole-filling model better adaptable and robust to the "foreground penetration" distortion, we trained CFFHNet by generating a batch of training samples by adding irregular holes to the foreground and background connection regions of high-quality images. Extensive experiments show the superiority of our CFFHNet over the current state-of-the-art DIBR methods. The source code will be available at https://github.com/wgc-vsfm/view-synthesis-CFFHNet.

6.
Eur J Med Chem ; 262: 115920, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37939444

RESUMO

In our work, several 7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-phenylhydrazone derivatives as α-glucosidase inhibitors (α-GIs) were synthesized and characterized by 1H NMR, 13C NMR, and HRMS spectrum. Then, their bio-activity against the α-glucosidase (α-Glu) was further evaluated. Among them, almost all compounds displayed better bio-activity with IC50 from 31.23 ± 0.89 to 213.50 ± 4.19 µM than acarbose (IC50 = 700.20 ± 10.55 µM). In particular, compound 5o showed the best potency to inhibit α-Glu in a mixed manner. Moreover, the action mechanisms of 5o were further clarified including fluorescence quenching, circular dichroism spectra, three-dimensional fluorescence spectra, molecular docking, etc. All mechanism studies revealed that 5o could arouse the changed secondary structure of α-Glu to hinder enzyme catalytic activity. It was observed from an in vivo study that 5o of 20 mg/kg could significantly decrease by 24.45 % postprandial blood glucose in mice vs. the control. Meanwhile, 5o had low drug-drug interaction potential and was likely to be an orally active compound. Moreover, 5o was observed to be no obvious cytotoxicity to HEK-293 cells. In summary, compound 5o exhibited one potential to be further applied as an antidiabetic drug.


Assuntos
Inibidores de Glicosídeo Hidrolases , Tiadiazinas , Humanos , Camundongos , Animais , Inibidores de Glicosídeo Hidrolases/química , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular , Células HEK293 , alfa-Glucosidases/metabolismo , Estrutura Molecular
7.
Prev Med ; 177: 107749, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37918447

RESUMO

BACKGROUND: Hepatitis C threatens human health and brings a heavy economic burden. Shandong Province is the second most populous province in China and has uneven regional economic development. Therefore, we analyzed the incidence rate trend and regional differences of hepatitis C in Shandong Province from 2004 to 2021. METHODS: The monthly and annual incidence rates of hepatitis C in Shandong Province from 2022 to 2030 were predicted by fitting Autoregressive Integrated Moving Average model (ARIMA), Long Short-Term Memory (LSTM) and ARIMA-LSTM combined model. RESULTS: From 2004 to 2021, annual new cases of hepatitis C in Shandong Province increased from 635 to 5834, with a total of 61,707 cases. The incidence rate increased from 0.69/100 thousand in 2004 to 6.40/100 thousand in 2019, with a slight decrease in 2020 and 2021. The average annual incidence rate was 3.47/100 thousand. In terms of regional distribution, the hepatitis C incidence rate in Shandong Province was generally high in the west and low in the east. It is estimated that the hepatitis C incidence rate in Shandong Province will be 9.21 per 100 thousand in 2030. CONCLUSION: The hepatitis C incidence rate in Shandong Province showed an increasing trend from 2004 to 2019 and a decreasing trend in 2020 and 2021. Significant regional variations in incidence rate existed. An upward trend in incidence rate is predicted from 2022 to 2030. It is necessary to strengthen the prevention and control of hepatitis C to achieve the goal of eliminating viral hepatitis by 2030.


Assuntos
Hepatite C , Humanos , Incidência , Hepatite C/epidemiologia , Hepacivirus , China/epidemiologia , Desenvolvimento Econômico
8.
Bioorg Chem ; 141: 106844, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37703743

RESUMO

To discover potent α-glucosidase inhibitors, a class of novel triazole-phenylacetamide derivatives (5a-5p) were designed, prepared, and tested for their α-glucosidase inhibitory effects. All tested compounds (5a-5p) displayed a strong α-glucosidase inhibitory activity (IC50 = 6.69 ± 0.18-113.65 ± 2.94 µM) in comparison with the positive control acarbose (IC50 = 723.06 ± 11.26 µM). Thereinto, 5g (IC50 = 6.69 ± 0.18 µM) showed the best anti-α-glucosidase activity and behaved as a mixed-type inhibitor with the value of Ki and Kis to be 1.65 µM and 4.54 µM, respectively. Besides, fluorescence quenching experiment, three-dimensional fluorescence spectra assay, circular dichroism analysis, and molecular docking studies indicated that 5g may inhibit α-glucosidase activity by binding with its active site as well as changing the secondary structure of α-glucosidase. Combined with the inhibition effect on the rise of postprandial blood glucose level and low cytotoxicity of 5g, it could be concluded that these title compounds may play a role as lead compounds to develop novel α-glucosidase inhibitors.


Assuntos
Inibidores de Glicosídeo Hidrolases , alfa-Glucosidases , Inibidores de Glicosídeo Hidrolases/química , alfa-Glucosidases/metabolismo , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular , Triazóis/química , Estrutura Molecular , Cinética
9.
J Chem Phys ; 159(11)2023 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-37721328

RESUMO

The ability to accurately monitor chiral biological molecules is of great significance for their potential applications in disease diagnosis and virus detection. As the existing chiral detection technologies are mainly relying on an optical method by using left/right circularly polarized light, the universality is low and the operation is complicated. Moreover, large quantity of chiral molecules is required, causing low detection efficiency. Here, a self-assembled monolayer of polypeptides has been fabricated to realize trace detection of chirality based on spin selectivity of photon-electron interaction. We have utilized Kerr technique to detect the rotation angle by the molecular monolayer, which indicates the chirality of polypeptides. The chiral structure of a biological molecule could result in spin-selectivity of electrons and thus influence the interaction between electron spin and light polarization. A Kerr rotation angle of ∼3° has been obviously observed, equivalent to the magneto-optic Kerr effect without magnetic material or magnetic field. Furthermore, we have provided a novel solution to achieve chirality discrimination and amplification simultaneously through an optical fiber. The proposed design is applicable for chiral detection via increasing their differential output signal, which clearly demonstrates a useful strategy toward chirality characterization of biological molecules.


Assuntos
Elétrons , Campos Magnéticos , Fótons , Rotação
10.
Int J Biol Macromol ; 252: 126490, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37625761

RESUMO

Oxalis corniculate L. (O. corniculate) was used to treat diabetes in Chinese folk as a popular tea drink. In this work, 31 compounds from O. corniculate were screened and identified as potential α-Glucosidase inhibitors (α-GIs). Among them, 6 compounds displayed stronger inhibitory activity than acarbose (IC50 = 212.9 ± 5.98 µg/mL). Especially, the most effective compounds quercetin (Qu, IC50 = 4.70 ± 0.40 µg/mL) and luteolin (Lu, IC50 = 15.72 ± 0.75 µg/mL) inhibited α-Glu in competitive and mixed manners, respectively. Moreover, fluorescence quenching, circular dichroism (CD), and molecular docking study revealed that they can arouse the changes in the secondary structure and hydrophobic micro-environment of the enzyme mainly through a hydrophobic binding. Furthermore, it was observed that oral administration of Qu (20 mg/kg) can significantly reduce postprandial blood glucose (PBG) levels in mice vs. the control group. To sum up, the above research confirmed that O. corniculate could prevent and treat postprandial hyperglycemia as a good tea drink, and the plant was an excellent source to obtain natural α-GIs.


Assuntos
Inibidores de Glicosídeo Hidrolases , Ultrafiltração , Camundongos , Animais , Inibidores de Glicosídeo Hidrolases/farmacologia , Inibidores de Glicosídeo Hidrolases/química , Simulação de Acoplamento Molecular , Cromatografia Líquida de Alta Pressão , alfa-Glucosidases/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Chá
11.
J Hazard Mater ; 457: 131822, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37315413

RESUMO

The ocean reserves nearly four billion tons of uranium, providing an inexhaustible supply of nuclear energy if the limits of ultralow U(VI) concentration (3.3 µg·L-1) are addressed. Membrane technology is promising to make this happen by simultaneous U(VI) concentration and extraction. Herein, we report a pioneering adsorption-pervaporation membrane for efficient enrichment and capture of U(VI) along with clean water production. A bifunctional poly(dopamine-ethylenediamine) and graphene oxide 2D scaffold membrane was developed and further crosslinked by glutaraldehyde, capable of recovering over 70% U(VI) and water from simulated seawater brine, which validates the feasibility of one-step water recovery, brine concentration, and uranium extraction from seawater brine. Moreover, compared with other membranes and adsorbents, this membrane exhibits fast pervaporation desalination (flux: 153.3 kg·m-2·h-1, rejection: >99.99%) and excellent uranium capture properties of 228.6 mg·m-2 benefiting from plentiful functional groups provided by embedded poly(dopamine-ethylenediamine). This study aims to provide a strategy for recovering critical elements from the ocean.

12.
Food Chem ; 419: 136106, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37030204

RESUMO

To develop new shrimp preservative agents with dual functions of anti-browning and antibacterial, thirteen hydroxypyranone-thiosemicarbazone derivatives were prepared according to molecular hybridization. Thereinto, compound 7j (IC50 = 1.99 ± 0.19 µM) shown the strongest anti-tyrosinase activity and was about twenty-three folds stronger than kojic acid (45.73 ± 4.03 µM). The anti-tyrosinase mechanism of 7j was illustrated through enzyme kinetic, copper ion chelating ability, fluorescence quenching, ultraviolet spectrum, AFM analysis, and molecular docking study. On the other hand, antibacterial assay and time-kill kinetics analysis confirmed that 7j also had good antibacterial activity against V. parahaemolyticus (MIC = 0.13 mM). PI uptake test, SDS-PAGE, and fluorescence spectrometry analysis proved that 7j can affect the bacterial cell membrane. Finally, the shrimp preservation and safety study indicated that 7j has dual effects of inhibiting bacterial growth and preventing enzyme browning, and can be applied to the preservation of fresh shrimp.


Assuntos
Agaricales , Tiossemicarbazonas , Tiossemicarbazonas/farmacologia , Simulação de Acoplamento Molecular , Inibidores Enzimáticos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Conservantes Farmacêuticos , Monofenol Mono-Oxigenase/metabolismo , Relação Estrutura-Atividade , Agaricales/metabolismo
13.
Food Chem ; 419: 136047, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37018861

RESUMO

A class of new kojic acid hybrids (7a-7o) bearing a 1,2,4-triazine moiety were prepared, and their inhibitory activities and mechanism on tyrosinase were investigated. All derivatives showed good to excellent anti-tyrosinase activity with IC50 values ranging from 0.34 ± 0.06 µM to 8.44 ± 0.73 µM. In kinetic study, compound 7m was a mixed-type inhibitor with Ki and Kis of 0.73 and 1.27 µM, respectively. The interaction mechanism toward tyrosinase of compound 7m was further elaborated in combination with molecular docking and various spectral techniques. The results showed that compound 7m could change the secondary structure of tyrosinase to reduce its catalytic activity. Anti-browning assays demonstrated that 7m inhibited the browning of bananas effectively during storage. What's more, 7m was found to have low cytotoxicity in vitro. In conclusion, compound 7m has the potential to be applied as an anti-browning agent.


Assuntos
Monofenol Mono-Oxigenase , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Agaricales/química , Simulação de Acoplamento Molecular
14.
Nanotechnology ; 34(31)2023 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-37075714

RESUMO

The non-collinear antiferromagnetic Weyl semimetal Mn3X (X = Ga, Ge, Sn) system has attracted a lot of attentions owing to its robust anomalous Hall effect (AHE), large spin Hall angle and small net magnetization at room temperature. The high spin-charge interconversion efficiency makes it a super candidate in topological antiferromagnetic spintronic devices, which could facilitate ultra-fast operation of high-density devices with low energy consumption. In this work, we have realized to obtain different chiral spin structures in Heusler alloy Mn3Ge thin films, which originate from different crystalline orientations. The high-quality (0002)- and (202¯0)-oriented single phase hexagonal Mn3Ge films are achieved by controllable growth, annealing process and ion implantation. The various magnetic properties and AHE behaviors are observed alongaandccrystal axes, equivalent to magnetic field in and out of the inverse triangular spin plane. The observation demonstrates the manipulation of crystal structure accompanied with chiral spin order in a non-collinear antiferromagnetic Mn3Ge film, which is induced by energy conversion and defect introduction. Thein situthermal treatment induces crystal phase rotation up to 90° and robust AHE modulation, which is significantly important and highly desirable for flexible spin memory device applications.

15.
Environ Sci Pollut Res Int ; 30(25): 67217-67226, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37103706

RESUMO

Limited studies examined the interaction effects between exposure to ambient PM2.5 and economic development on the settlement intention of floating population. We used binary logistic model to examine the association of PM2.5, per capita GDP (PGDP), PM2.5 [Formula: see text] PGDP on the settlement intention. Additive interaction term of PM2.5 and PGDP level was used to investigate their interactive effects. Overall, each one grade increment in annual average PM2.5 was associated with decreased probability of settlement intention (OR = 0.847, 95%CI: 0.811-0.885). The interaction effect between PM2.5 and PGDP on settlement intention was significant (OR = 1.168, 95%CI: 1.142-1.194). The stratified analysis showed PM2.5 exhibits lower settlement intention in the aged 55 years or above, engaged in low-skilled works, and living in the western China. This study indicates that PM2.5-exposed will decrease the settlement intention of floating population. High economic development level can weaken the relationship between PM2.5 and settlement intention. Policymakers should balance the socio-economic development and environmental health and focus on vulnerable population.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Atmosféricos/análise , Material Particulado/análise , Poluição do Ar/análise , Intenção , Desenvolvimento Econômico , China/epidemiologia
16.
Environ Sci Pollut Res Int ; 30(23): 63716-63726, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37058237

RESUMO

There are limited studies investigating the relationship between exposure to PM2.5 and the health status among the mobile population. A cross-sectional analysis was performed in a nationally representative sample (2017 China Migrants Dynamic Survey data) consisting of 169,469 mobile population. The ordered logistic regression model was used to examine the association between PM2.5 and the health status in mobile population. Stratified analyses were performed to identify whether the association varied across gender, age group, and regions in China. Overall, every 10 µg/m3 increment in annual average PM2.5 was associated with increased risk of poor self-reported health (OR = 1.021, 95% CI: 1.012-1.030). Mobile population aged 31-49 years and living in the central region suffers the highest PM2.5-associated health risk (OR = 1.030, 95% CI: 1.019-1.042; OR = 1.095, 95% CI: 1.075-1.116). Our study suggests that PM2.5 exposure was associated with an increased risk of poor self-reported health in mobile population, particularly among the population aged 31-49 years and people living in the central region of China. Policymakers should pay more attention to the vulnerable mobile population to tackle the health burden of ambient air pollution.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Humanos , Cidades , Poluentes Atmosféricos/análise , Material Particulado/análise , Estudos Transversais , Poluição do Ar/análise , China/epidemiologia , Nível de Saúde , Exposição Ambiental/análise
17.
Nat Commun ; 14(1): 840, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36792610

RESUMO

Multiferroic materials have great potential in non-volatile devices for low-power and ultra-high density information storage, owing to their unique characteristic of coexisting ferroelectric and ferromagnetic orders. The effective manipulation of their intrinsic anisotropy makes it promising to control multiple degrees of the storage "medium". Here, we have discovered intriguing in-plane electrical and magnetic anisotropies in van der Waals (vdW) multiferroic CuCrP2S6. The uniaxial anisotropies of current rectifications, magnetic properties and magnon modes are demonstrated and manipulated by electric direction/polarity, temperature variation and magnetic field. More important, we have discovered the spin-flop transition corresponding to specific resonance modes, and determined the anisotropy parameters by consistent model fittings and theoretical calculations. Our work provides in-depth investigation and quantitative analysis of electrical and magnetic anisotropies with the same easy axis in vdW multiferroics, which will stimulate potential device applications of artificial bionic synapses, multi-terminal spintronic chips and magnetoelectric devices.

18.
Bioorg Chem ; 132: 106384, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36696731

RESUMO

To develop novel α-glucosidase inhibitors, a series of chromone-based phenylhydrazone and benzoylhydrazone derivatives were designed, synthesized, and evaluated their inhibitory effects on α-glucosidase. The target compounds were characterized using 1H NMR, 13C NMR, and high-resolution mass spectra. Some of the compounds showed a varying degree of α-glucosidase inhibitory activity with IC50 values ranging from 6.59 ± 0.09 to 158.55 ± 0.87 µM. Among them, compound 5c (IC50 = 6.59 ± 0.09 µM) was the most potent inhibitor by comparison with positive control acarbose (IC50 = 685.11 ± 7.46 µM). Enzyme kinetic, fluorescence analysis, circular dichroism spectra, and molecular docking techniques were employed to explain the underlying molecular mechanisms of 5c inhibition on α-glucosidase. In vivo sucrose-loading test showed that 5c could suppress the rise of blood glucose levels after loading sucrose in normal Kunming mice. The cytotoxicity assay indicated that 5c exhibited low cytotoxicity.


Assuntos
Hipoglicemiantes , alfa-Glucosidases , Camundongos , Animais , Hipoglicemiantes/química , Simulação de Acoplamento Molecular , alfa-Glucosidases/metabolismo , Relação Estrutura-Atividade , Cromonas/farmacologia , Cromonas/química , Inibidores de Glicosídeo Hidrolases/química , Estrutura Molecular
19.
Curr Res Food Sci ; 6: 100421, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36605465

RESUMO

Kojic acid-aromatic aldehydes 6a-6m were synthesized and screened for their anti-tyrosinase activities. These compounds showed potently anti-tyrosinase activity with IC50 values in the range of 5.32 ± 0.23 to 77.89 ± 3.36 µM compared with kojic acid (IC50 = 48.05 ± 3.28 µM). Thereinto, compound 6j with 3-fluorine and 4-aldehyde substitutions showed the most potent anti-tyrosinase activity (IC50 = 5.32 ± 0.23 µM). Enzyme kinetic study revealed that 6j is a noncompetitive tyrosinase inhibitor (Ki = 2.73 µM). The action mechanism of 6j was evaluated by fluorescence spectrum quenching, molecular docking, 1H NMR titration, etc. The anti-browning assay showed that 6j could delay the enzymatic browning of fresh-cut apples. Besides, the cell viability assay proved that 6j had a good safety profile as an anti-browning agent. Hence, these results identify a new class of anti-tyrosinase and anti-browning agents for further investigation in the food industry.

20.
IEEE Trans Neural Netw Learn Syst ; 34(7): 3594-3608, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34559666

RESUMO

Deep learning models have been able to generate rain-free images effectively, but the extension of these methods to complex rain conditions where rain streaks show various blurring degrees, shapes, and densities has remained an open problem. Among the major challenges are the capacity to encode the rain streaks and the sheer difficulty of learning multi-scale context features that preserve both global color coherence and exactness of detail. To address the first problem, we design a non-local fusion module (NFM) and an attention fusion module (AFM), and construct the multi-level pyramids' architecture to explore the local and global correlations of rain information from the rain image pyramid. More specifically, we apply the non-local operation to fully exploit the self-similarity of rain streaks and perform the fusion of multi-scale features along the image pyramid. To address the latter challenge, we additionally design a residual learning branch that is capable of adaptively bridging the gaps (e.g., texture and color information) between the predicted rain-free image and the clean background via a hybrid embedding representation. Extensive results have demonstrated that our proposed method is able to generate much better rain-free images on several benchmark datasets than the state-of-the-art algorithms. Moreover, we conduct the joint evaluation experiments with respect to deraining performance and the detection/segmentation accuracy to further verify the effectiveness of our deraining method for downstream vision tasks/applications. The source code is available at https://github.com/kuihua/MSHFN.


Assuntos
Algoritmos , Redes Neurais de Computação , Benchmarking , Software , Processamento de Imagem Assistida por Computador
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