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1.
Phys Chem Chem Phys ; 23(23): 13128-13135, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34075977

RESUMO

Chiral metasurfaces patterned with L-shaped holes in a thin film of Dirac semimetal Cd3As2 are designed. The impact of temperature T on circular conversion dichroism, mainly characterized by circular polarization differential transmittance (CPDT), is studied by rigorous coupled-wave analysis. The results show that decreasing T will give rise to the appearance of much more narrow CPDT peaks and dips, and the maximum differential transmittance between two opposite circularly polarized light can reach above 0.60 by optimizing the structural parameters at 80 K. As the T increases, the differential transmittance gradually decreases, and the CPDT peak and dip values exhibit variation tendencies of 'Z' and 'S' types, respectively. Two simple formulae of CPDT extreme values with respect to T are derived, predicting that the decreasing tendency will reach saturation when T ≥ 500 K. Differing from the wavelength-independent variation trend of differential transmittance, CPDT extremum positions mainly show a blueshift (redshift) tendency at the wavelength λ > 10 µm (λ < 5 µm) as the T increases. Moreover, evolutions of CPDT with various factors including the thickness of Cd3As2, incident and azimuth angles are also clearly unveiled.

2.
Cell Mol Gastroenterol Hepatol ; 12(3): 1001-1019, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33965587

RESUMO

BACKGROUND & AIMS: Pharmacologic agents targeting bile acid signaling show promise for treating nonalcoholic steatohepatitis (NASH). However, clinical findings suggest that new treatment strategies with enhanced therapeutic efficacy and minimized undesired effects are needed. This preclinical study investigates whether combining an apical sodium-bile acid transporter (ASBT) inhibitor GSK233072 (GSK672) and fibroblast growth factor-15 (FGF15) signaling activation improves anti-NASH efficacy. METHODS: Mice with high fat, cholesterol, and fructose (HFCFr) diet-induced NASH and stage 2 fibrosis are used as a NASH model. GSK672 or AAV8-TBG-FGF15 interventions are administered alone or in combination to HFCFr diet-fed mice. RESULTS: The combined treatment significantly enhances therapeutic efficacy against steatosis, inflammation, ballooning, and fibrosis than either single treatment. Mechanistically, the synergistic actions of GSK672 and FGF15 on inhibiting gut bile acid reuptake and hepatic bile acid synthesis achieve greater magnitude of bile acid pool reduction that not only decreases bile acid burden in NASH livers but also limits intestinal lipid absorption, which, together with FGF15 signaling activation, produces weight loss, reduction of adipose inflammation, and attenuated hepatocellular organelle stress. Furthermore, the combined treatment attenuates increased fecal bile acid excretion and repressed bile acid synthesis, which underlie diarrhea and hypercholesterolemia associated with ASBT inhibition and FGF19 analogue, respectively, in clinical settings. CONCLUSIONS: Concomitant ASBT inhibition and FGF15 signaling activation produce metabolic changes that partially mimic the bariatric surgery condition whereby lipid malabsorption and increased FGF15/19 signaling synergistically mediate weight loss and metabolic improvement. Further clinical studies may be warranted to investigate whether combining ASBT inhibitor and FGF19 analogue enhances anti-NASH efficacy and reduced treatment-associated adverse events in humans.

3.
Alcohol Clin Exp Res ; 45(6): 1188-1199, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33885179

RESUMO

BACKGROUND: Recent studies have shown that human and experimental alcohol-related liver disease (ALD) is robustly associated with dysregulation of bile acid homeostasis, which may in turn modulate disease severity. Pharmacological agents targeting bile acid metabolism and signaling may be potential therapeutics for ALD. METHODS: The potential beneficial effects of a gut-restricted apical sodium-dependent bile acid transporter (ASBT) inhibitor were studied in a chronic-plus-binge ALD mouse model. RESULTS: Blocking intestinal bile acid reabsorption by the gut-restricted ASBT inhibitor GSK2330672 attenuated hepatic steatosis and liver injury in a chronic-plus-binge ALD mouse model. Alcohol feeding is associated with intestinal bile acid accumulation but paradoxically impaired ileal farnesoid × receptor (FXR) function, and repressed hepatic cholesterol 7α-hydrolase (CYP7A1) expression despite decreased hepatic small heterodimer partner (SHP) and ileal fibroblast growth factor 15 (FGF15) expression. ASBT inhibitor treatment decreased intestinal bile acid accumulation and increased hepatic CYP7A1 expression, but further decreased ileal FXR activity. Alcohol feeding induces serum bile acid concentration that strongly correlates with a liver injury marker. However, alcohol-induced serum bile acid elevation is not due to intrahepatic bile acid accumulation but is strongly and positively associated with hepatic multidrug resistance-associated protein 3 (MRP4) and MRP4 induction but poorly associated with sodium-taurocholate cotransporting peptide (NTCP) expression. ASBT inhibitor treatment decreases serum bile acid concentration without affecting hepatocyte basolateral bile acid uptake and efflux transporters. CONCLUSION: ASBT inhibitor treatment corrects alcohol-induced bile acid dysregulation and attenuates liver injury in experimental ALD.

4.
Sensors (Basel) ; 19(14)2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31311185

RESUMO

Firmness changes in Nanguo pears under different freezing/thawing conditions have been characterized by hyperspectral imaging (HSI). Four different freezing/thawing conditions (the critical temperatures, numbers of cycles, holding time and cooling rates) were set in this experiment. Four different pretreatment methods were used: multivariate scattering correction (MSC), standard normal variate (SNV), Savitzky-Golay standard normal variate (S-G-SNV) and Savitzky-Golay multiplicative scattering correction (S-G-MSC). Combined with competitive adaptive reweighted sampling (CARS) to identify characteristic wavelengths, firmness prediction models of Nanguo pears under different freezing/thawing conditions were established by partial least squares (PLS) regression. The performance of the firmness model was analyzed quantitatively by the correlation coefficient (R), the root mean square error of calibration (RMSEC), the root mean square error of prediction (RMSEP) and the root mean square error of cross validation (RMSECV). The results showed that the MSC-PLS model has the highest accuracy at different cooling rates and holding times; the correlation coefficients of the calibration set (Rc) were 0.899 and 0.927, respectively, and the correlation coefficients of the validation set (Rp) were 0.911 and 0.948, respectively. The accuracy of the SNV-PLS model was the highest at different numbers of cycles, and the Rc and the Rp were 0.861 and 0.848, respectively. The RMSEC was 65.189, and the RMSEP was 65.404. The accuracy of the S-G-SNV-PLS model was the highest at different critical temperatures, with Rc and Rp values of 0.854 and 0.819, respectively, and RMSEC and RMSEP values of 74.567 and 79.158, respectively.


Assuntos
Processamento de Imagem Assistida por Computador , Pyrus/crescimento & desenvolvimento , Espectroscopia de Luz Próxima ao Infravermelho , Algoritmos , Calibragem , Congelamento , Análise dos Mínimos Quadrados , Pyrus/anatomia & histologia
5.
Materials (Basel) ; 12(10)2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31117302

RESUMO

Ni-based composite coating containing nanodiamonds was deposited on the substrate of Q235A low-carbon steel in a traditional Watts solution, without any additive. The nanodiamond grains prepared by detonation synthesis were measured by Transmission electron microscope (TEM) and X-ray diffraction (XRD). The electrochemical behavior of Ni2+ ion in the composite bath including nanodiamonds was studied by linear sweep voltammetry experiments, and the morphology, elastic modulus, and hardness of Ni-based composite coating were characterized using Scanning Electron microscope (SEM) and the nano-indenter XP tester. Effects of the nanodiamond concentration in the bath, stirring speed, and the electroplate mode on the properties of Ni-based composite coating were investigated. The results show that the reduction of Ni2+ ion in the electroplating process increased initially, and then decreased as the nanodiamond concentration in the bath increased from 4 g/L to 16 g/L, irrespective of whether direct current (DC), single-pulse, or double-pulse electroplating mode was used. The highest over-potential could be obtained when the nanodiamond concentration in the bath was 8 g/L. Moreover, the hardness and elastic modulus of the composite coating prepared by the DC electroplating mode were 4.68 and 194.30 GPa, respectively. By using the same plating parameters, the coating prepared by the double-pulse electroplating mode showed better properties, with hardness and elastic modulus values of 5.22 and 197.38 GPa, respectively.

6.
Sensors (Basel) ; 18(11)2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30441764

RESUMO

Evaluation of impact damage to mango (Mangifera indica Linn) as a result of dropping from three different heights, namely, 0.5, 1.0 and 1.5 m, was conducted by hyperspectral imaging (HSI). Reflectance spectra in the 900⁻1700 nm region were used to develop prediction models for pulp firmness (PF), total soluble solids (TSS), titratable acidity (TA) and chroma (∆b*) by a partial least squares (PLS) regression algorithm. The results showed that the changes in the mangoes' quality attributes, which were also reflected in the spectra, had a strong relationship with dropping height. The best predictive performance measured by coefficient of determination (R²) and root mean square errors of prediction (RMSEP) values were: 0.84 and 31.6 g for PF, 0.9 and 0.49 oBrix for TSS, 0.65 and 0.1% for TA, 0.94 and 0.96 for chroma, respectively. Classification of the degree of impact damage to mango achieved an accuracy of more than 77.8% according to ripening index (RPI). The results show the potential of HSI to evaluate impact damage to mango by combining with changes in quality attributes.


Assuntos
Frutas/fisiologia , Mangifera/fisiologia , Algoritmos , Análise dos Mínimos Quadrados
7.
Int J Clin Exp Med ; 8(11): 22004-10, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26885173

RESUMO

BACKGROUND: Inflammatory responses induced by ox-LDL play important roles in atherogenesis, and could be promoted in diabetic patients. Toll-like receptor (TLR)2 is an innate inflammatory receptor, and is enhanced in human umbilical vein endothelial cells (HUVECs) under high glucose conditions. Ox-LDL-TLR2 pathway activation and further inflammation in monocytes are involved in the atherosclerosis formation. OBJECTIVE: What role of TLR2 plays on ox-LDL-induced inflammation in HUVECs remains unclear, especially in high glucose conditions. The purpose of this study is to explore the effect and role of ox-LDL-TLR2 pathway on the inflammatory responses in HUVECs. METHODS: 1 hour prior to the treatment, HUVECs were treated with or without neutralizing anti-TLR2 antibody. After that, HUVECs were treated with ox-LDL (20, or 40 µg/ml) or LPS (200 ng/ml) under normal and high glucose conditions. The expressions of ICAM-1 and TLR2 protein were analyzed by immunoblotting, and IL-6 and IL-8 were measured by ELISA. RESULTS: Compared with those in normal glucose condition, IL-6 and IL-8 expression were increased in high glucose condition. The stimulation of ox-LDL and LPS both increased the expression of ICAM-1, IL-6 and IL-8, but did not change TLR2 protein expression in both normal and high glucose conditions. Additionally, the expression of ICAM-1, IL-6 and IL-8 was not changed when TLR2 was knocked out under these two conditions. CONCLUSION: The inflammatory responses induced by Ox-LDL were not changed with or without TLR2 under both normal and high glucose conditions in HUVECs. Our study indicates TLR2 is not involved in the ox-LDL mediated endothelial injury under high glucose conditions, which is an important step of atherosclerosis formation in diabetes.

8.
J Nanosci Nanotechnol ; 13(10): 6679-86, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24245129

RESUMO

Self-healing materials are inspired by biological systems in which damage triggers an autonomic healing response. The damage properties of a self-healing polymer composite were investigated by numerical simulation in this paper. Unit cell models with single-edge centered crack and single-edge off-centered crack were employed to investigate the damage initiation and crack evolution by the extended finite element method (XFEM) modeling. The effect of microcapsule's Young's modulus on composites was investigated. Result indicates the microcapsule's Young's modulus has little effect on the unit cell's carrying capacity. It was found that during the crack propagation process, its direction is attracted toward the microcapsules, which makes it helpful for the microcapsules to be ruptured by the propagating crack fronts resulting in release of the healing agent into the cracks by capillary action.

9.
Invest Ophthalmol Vis Sci ; 53(7): 3572-83, 2012 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-22577078

RESUMO

PURPOSE: Oxidative stress induces retinal damage and contributes to vision loss in progressive retinopathies. Carcinine (ß-alanyl-histamine) is a natural imidazole-containing peptide derivative with antioxidant activity. It is predicted to scavenge 4-hydroxynonenal (4-HNE), a toxic product of lipid oxidation. The aim of this study was to confirm the 4-HNE scavenging effect and evaluate the neuroprotective effect of carcinine in mouse retina subjected to oxidative stress. METHODS: HPLC coupled with mass spectrometry was used to analyze carcinine and 4-HNE-carcinine adduct. Protection of retinal proteins from modification by 4-HNE was tested by incubating carcinine with retinal protein extract and 4-HNE. Modified retinal proteins were quantified by dot-blot analysis. Mice were treated with carcinine (intravitreal injection and gavage) and exposed to bright light to induce oxidative damage in the retina. Photoreceptor degeneration was measured by histology and electroretinography. Retinal levels of retinol dehydrogenase 12 (RDH12) were measured by immunoblot analysis, after exposure to bright light and in retinal explants after exposure to 4-HNE. RESULTS: The ability of carcinine to form an adduct with 4-HNE, as well as to prevent and even reverse the adduction of retinal proteins by the toxic aldehyde was demonstrated in vitro. Carcinine, administered by intravitreal injection or gavage, strongly protected mouse retina against light-induced photoreceptor degeneration and had a protective effect on RHD12, a protein found specifically in photoreceptor cells. CONCLUSIONS: This study suggests that carcinine can be administered noninvasively to efficiently protect photoreceptor cells from oxidative damage. Carcinine could be administered daily to prevent vision loss in progressive retinopathies.


Assuntos
Aldeídos/metabolismo , Carnosina/análogos & derivados , Proteínas do Olho/efeitos dos fármacos , Retina/efeitos dos fármacos , Degeneração Retiniana/patologia , Retinal Desidrogenase/efeitos dos fármacos , Animais , Células 3T3 BALB , Carnosina/farmacologia , Cromatografia Líquida de Alta Pressão , Eletrorretinografia , Proteínas do Olho/metabolismo , Espectrometria de Massas , Camundongos , Fármacos Neuroprotetores , Estresse Oxidativo/efeitos dos fármacos , Retinal Desidrogenase/metabolismo
10.
J Sep Sci ; 27(14): 1189-94, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15537075

RESUMO

A high-performance liquid chromatography (HPLC) system was used to determine the antioxidants tert-butyl-hydroquinone (TBHQ), tert-butylhydroxyanisole (BHA), and 3,5-di-tert-butylhydroxytoluene (BHT) simultaneously in oils. The paper presents a new methodology for the optimized separation of antioxidants in oils based on the coupling of experimental design and artificial neural networks. The orthogonal design and the artificial neural networks with extended delta-bar-delta (EDBD) learning algorithm were employed to design the experiments and optimize the variables. The response function (Rf) used was a weighted linear combination of two variables related to separation efficiency and retention time, according to which the optimized conditions were obtained. The above-mentioned antioxidants in rapeseed oils were separated and determined simultaneously under optimized conditions by HPLC with UV detection at 280 nm. Linearity was obtained over the range of 10-200 microg/mL with recoveries of 98.3% (TBHQ), 98.1% (BHT), and 96.2% (BHA).


Assuntos
Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Redes Neurais de Computação , Hidroxianisol Butilado/análise , Hidroxitolueno Butilado/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Graxos Monoinsaturados , Hidroquinonas/análise , Óleos Vegetais/química , Óleo de Brassica napus , Projetos de Pesquisa
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