OPTICAL MATERIALS
·
2023
·
IF 3.9
Yibo Zhang,Shen Wang,Biao Liu,Yan Hao
MgAl 2 O 4 :Cr 3+ transparent ceramics were prepared by a hot-pressed sintering process with Y 2 O 3 and La 2 O 3 as sintering aids, and the effects on the microstructure, densification, optical transmission, and photoluminescent properties were investigated. The sintering aids of Y 2 O 3 and La 2 O 3 enhanced the relative density, reaching 99.33% with 2.4 wt% Y 2 O 3 and 99.24% with 0.8 wt% La 2 O 3 . La 2 O 3 also inhibited abnormal grain growth and obtained ceramics with uniform grain size. In addition, the optical transmission was also improved with Y 2 O 3 and La 2 O 3 as sintering aids. The transmission of the ceramic with 2.4 wt% Y 2 O 3 exceeded 78% in the region of 700–6000 nm and reached 83% at 1450 nm. Moreover, Y 2 O 3 and La 2 O 3 both contributed to improving the quantum yield of the ceramics, especially for Y 2 O 3 , and the quantum yield was about 0.354, which was approximately two times higher than that without R 2 O 3 . In summary, La 2 O 3 was helpful for improving sintering process, inhibiting grain growth, and homogenizing the grain size, while Y 2 O 3 was significant for enhancing the optical and photoluminescent properties.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
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光电子学
·
固态发光材料
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BIOTECHNOLOGY AND BIOENGINEERING
·
2026
·
IF 3.9
Teng-Kun Huang,Cen Huang,Du Wu,Shuang Li,Ren-Chao Zheng,Xiao-Ling Tang,Yu-Guo Zheng
( R )-3-Aminobutanol is a valuable chiral amino alcohol widely used in the pharmaceutical industry. The amine dehydrogenase (AmDH)-catalyzed synthesis with inorganic ammonia as the amine donor represents one of the most promising routes for its production. However, this approach is limited by the low catalytic efficiency of AmDHs toward the unnatural substrate 4-hydroxy-2-butanone, as well as the high cost associated with coenzyme requirements. To address these issues, a structure-guided engineering strategy integrating loop remodeling with dynamically coupled network analysis was employed to modify an AmDH derived from leucine dehydrogenase ( GKGB -AmDH). A pentamutant was obtained with a 7.8-fold increase in catalytic efficiency ( k cat / K m ) and a 6.8-fold increase in specific activity. Molecular dynamics simulations were performed to elucidate the molecular mechanism underlying the improved catalytic performance. A dual − enzyme co-expression system for GKGB -AmDH-M5 and formate dehydrogenase (FDH) was established for in situ NADH regeneration. As a result, the catalytic efficiency toward 4-hydroxy-2-butanone was enhanced, and the conversion reached 83.8% at a substrate concentration of 300 mM, with an enantiomeric excess ( e.e .) of > 99.99%. These results demonstrate the feasibility of this engineering strategy and provide a theoretical basis for the efficient and green biomanufacturing of chiral amino alcohols.
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iScience
·
2025
·
IF 4.1
Hechen Shen,Xu Bao,Bingcai Qi,Xiaoyu Liang,Yun Chang,Xiaomin Hu,Wenqing Gao,Di Sun
Myocardial infarction (MI) poses a severe threat to human life, and timely reperfusion of ischemic myocardium stands as the most effective treatment approach. However, myocardial ischemia-reperfusion (I/R) could lead to the excessive generation of reactive oxygen species (ROS), worsening myocardial injury. In this investigation, a ROS-responsive injectable hydrogel encapsulating melatonin (MLT) was synthesized. This hydrogel could provide a controlled release of MLT, markedly enhancing its antioxidant, anti-inflammatory, anti-apoptotic, and autophagy-modulating effects, thereby significantly mitigating myocardial ischemia-reperfusion injury (MIRI). Moreover, this study proposes an injection method of ultrasound delivery, which offers significant advantages to MI patients without the necessity of thoracotomy In conclusion, This ROS-responsive hydrogel loaded with MLT established the basis for minimally invasive treatment of myocardial I/R injury, which has considerable potential for the treatment of MIRI.
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PubMed
高影响因子
CURRENT NEUROVASCULAR RESEARCH
·
2025
·Vol. 22
·期 1
·70-85
·
IF 1.7
Ziteng Yang,Yuanqi Zuo,Guangyun Wang,Ning Wang
Introduction: The endothelial barrier is composed of brain microvascular endothelial cells (BMECs) and tight junction (TJ) proteins. Musk is a valuable ingredient in Traditional Chinese Medicine (TCM). It is used in the treatment of stroke because of its ability to induce resuscitation. The core component of musk is muscone. Previous studies have evidenced that muscone may be involved in the treatment of ischemic stroke (IS), but the underlying mechanism is still unclear. The main objective of this study was to explore the protective effect of muscone on OGD/R-induced endothelial barrier disruption and determine its underlying mechanism. Methods: OGD/R-induced damage to BMECs was assessed using the MTT and LDH assays. The apoptosis level in BMECs was determined using western blot and Hoechst staining. Western blot, immunofluorescence, and phalloidin staining were used to assess the expressions of TJ proteins and pathway proteins expression. A monolayer cell barrier was constructed using BMECs in vitro, and the permeability of the barrier was assessed by TEER as well as the transmissivity of sodium fluorescein. Molecular docking, DARTS, and CETSA were used to verify the regulatory effect of muscone on the pathway. Results: Muscone reduced OGD/R-induced apoptosis of BMEC cells, inhibited the degradation of TJ proteins, promoted the coherent expression of ZO-1 on the membrane, and restored TEER. Mechanistic studies showed that H-89 reversed the promoting effects of muscone on pathway proteins and promoted the disassembly of the actin cytoskeleton, which, in turn, promotes BMEC apoptosis and TJ protein degradation, ultimately disrupting the endothelial barrier. Discussion: The inhibition of BMEC apoptosis and improvement of endothelial barrier damage by muscone may be an important mechanism for treating ischemic stroke. Conclusion: We demonstrated that muscone could reduce OGD/R-induced hyperpermeability of the brain endothelial barrier by activating the PKA/RHOA/MLC pathway.
研究领域:
神经科学
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药理学
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中医中药
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细胞生物学
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分子生物学
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DOI
PubMed
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2021
·
IF 3.575
Dequan Kong,Baoying Xie,Yuhang Li,Yaping Xu
Palmitoylethanolamide (PEA) offers a strong protection against BBB disruption and neurological deficits after cerebral ischaemic/reperfusion (I/R) injury. To date, these BBB protective effects of PEA are mainly attributed to PPARα-mediated actions. However, whether PEA protects against BBB disruption through direct regulation of cytoskeletal microfilaments remains unknown. Here, we identified PEA as a Rho-associated protein kinase (ROCK2) inhibitor (IC 50 = 38.4 ± 4.8 μM). In vitro data suggested that PEA reduced the activation of ROCK/MLC signaling and stress fiber formation within microvascular endothelial cells (ECs) after oxygen-glucose deprivation (OGD), and consequently attenuated early (0–4 h) EC barrier disruption. These actions of PEA could not be blocked by the PPARα antagonist GW6471. In summary, the present study described a previously unexplored role of PEA as a ROCK2 inhibitor, and propose a PPARα-independent mechanism for pharmacological effects of PEA.
研究领域:
神经科学
·
药理学
·
细胞生物学
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PubMed
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Journal of Herbal Medicine
·
2023
·
IF 2.3
Ying Liu,Xia Zhang,Huaiyu Cheng,Yifang Li,Guangxiong Zhou
ABSTRACT Introduction It has a long history to employ Macleaya cordata (Willd.) R. Br. (Papaveraceae) for the treatment of a variety of diseases in China. Chelerythrine, one of the major of M. cordata with detoxifying and anti-inflammatory effect, is reported to combat bacteria and fungus. This work aims to explore the effect of chelerythrine against fluconazole-resistant C. albicans and also illustrate its potential mechanism. Methods The microdilution method, following CLSI-M27-A3 was used to evaluate the effect of chelerythrine against fluconazole-resistant C. albicans. Meanwhile, biofilm viability was assessed by XTT assay and cell morphology was observed by inverted microscope. RT-qPCR and confocal laser scanning microscope were employed to detect the mRNA expression and DCFH-DA staining, respectively. Fluorescence intensity was quantified by flow cytometry. Results The total alkaloids extract of M. cordata significantly inhibited the viability of C. albicans, concentration of which in 64 μg/mL presented to 40% inhibitory effect . In addition, the MIC 80 for chelerythrine was 8 μM, whereas chelerythrine in 4 μM inhibited biofilm formation by 47.7%. Further studies revealed that chelerythrine reduced the hydrophobicity of cellular surface, inhibited hyphal growth, downregulated the expression of genes related to cAMP pathway, increased cellular permeability and promoted the production of reactive oxygen species (ROS). Conclusion Chelerythrine inhibited biofilm formation by decreasing CSH and inhibiting the cAMP pathway. Chelerythrine increased cellular permeability and promoted the production of reactive oxygen species, which leads to the cell death of fluconazole-resistant C. albicans .
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FOOD CHEMISTRY
·
2018
·
IF 4.946
Ying Zhou,Qiyuan Peng,Ling Zhang,Sihua Cheng,Lanting Zeng,Fang Dong,Ziyin Yang
1-Phenylethanol is a chiral flavor compound that has enantiomers, ( R )- and ( S )-1-phenylethanol, with different flavor properties. Given that isolating these enantiomers from plants is low yielding and costly, enzymatic synthesis presents an alternative approach. However, the genes/enzymes that specifically produce ( R )- and ( S )-1-phenylethanol in plants are unknown. To identify these enzymes in tea ( Camellia sinensis ) flowers, 21 short chain dehydrogenase (SDR) genes were isolated from tea flowers, cloned, and functionally characterized. Several recombinant SDRs in Escherichia coli exhibited activity for converting acetophenone to ( S )-1-phenylethanol (CsSPESs, >99.0%), while only one SDR produced ( R )-1-phenylethanol (CsRPES, 98.6%). A pair of homologue enzymes (CsSPES and CsRPES) showed a strong preference for NADPH cofactor, with optimal enzymatic reaction conditions of 45–55 °C and pH 8.0. Identification of the tea flower-derived gene responsible for specific synthesis of ( R )- and ( S )-1-phenylethanolsuggests enzymatic synthesis of enantiopure 1-phenylethanol is possible using a plant-derived gene.
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高影响因子
Crystals
·
2022
·Vol. 12
·期 11
·1608
·
IF 2.67
Zijun Ye,Yu Jiang,Minmin Mao,Zhiyu Xiu,Mengjiao Chi,Guofa Wu,Bing Liu,Dawei Wang,Bin Yang,Kaixin Song
In this work, Y2.95R0.05MgAl3SiO12(R = Yb, Y, Dy, Eu, Sm) microwave single-phase dielectric ceramics were successfully prepared via a conventional ceramic sintering technology by doping a series of rare earth elements (Yb, Y, Dy, Eu, Sm) with different ionic radii for the first time. The effects of A-sites occupied by rare earth elements on the microwave dielectric properties of Y2.95R0.05MgAl3SiO12were studied using crystal structure refinement, a scanning electron microscope (SEM), bond valence theory, P-V-L theory, and infrared reflection spectroscopy. It was found that the ionicity of the Y-O bond, the lattice energy, the bond energy, and the bond valance of the Al(Tet)-O bond had important effects on the microwave dielectric properties. Particularly, the optimum microwave dielectric properties,εr= 9.68,Q×f= 68,866 GHz, andτf= −35.8 ppm/°C, were obtained for Y2.95Dy0.05MgAl3SiO12when sintered at 1575 °C for 6 h, displaying its potential for 5G communication.Keywords:garnet;microwave dielectric properties;P–V–L theory;infrared reflection spectroscopy
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Xu Xu,Chaonan Jiao,Hao Yang,Hao Chen,Jing Wang
Au NPs generated in situ by photochemical reduction method were used as catalysts for the oxidation of sodium cholate . The circular dichroism of the oxidation product of sodium cholate exhibits a positive Cotton effect at 335 nm and an intense negative Cotton effect at 281 nm. Electrospray ionization (ESI) mass spectra and nuclear magnetic resonance (NMR) spectra were performed to characterize the chemical composition of the oxidation product of sodium cholate, revealing that two of the hydroxyl groups were selectively oxidized to oxo groups and the oxidation product is 12-hydroxy-3,7-diketo-cholanic acid (3,7-DKCA). The chiral recognition abilities of the aggregates of 3,7-DKCA were investigated by using planar chiral molecules R- and S-binaphthyl compounds. Compared with sodium cholate, the aggregates of 3,7-DKCA displayed higher chiral selective host–guest binding to the model molecules and the chiral recognition mechanism was clarified.
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BIOMEDICINE & PHARMACOTHERAPY
·
2021
·
IF 6.53
Yi-yu Liang,Kun-wei Li,Feng-jv Niu,Ying Li,Hao-cheng Wei,Yun-lei Dai,Yun-yu Wang,Chang-zheng Zhou,Xin-huan Wan
Objective To investigate the antiviral effect of Salvia plebeia R. Br. polysaccharides (SPP) against RSV and underlying mechanisms. Methods SPP was extracted via alcohol-precipitation method and extract was separated into various fractions using ultrafiltration method. The polysaccharide content was determined using UV-Vis. Antiviral effect of SPP and fractions was measured using MTT method and Reed-Muench method. Sixty Balb/c mice were randomly divided into 6 groups, and received either Ribavirin or SPP. Their body weight and food intake were recorded every day throughout the experiment period. The lung index inhibition ratio and pulmonary virus titer were determined followed by the histological analysis of lungs. Furthermore, time-of-addition and effective stage analysis were carried out to determine the mechanism of action. The TLR-3 and TLR-4 levels in the lungs were determined using qRT-PCR. The levels of IFN-γ, IL-2 and TNF-α in serum were determined using ELISA. Results The SPP content is 4.396%. SPP has shown a good anti-RSV effect both in vitro (TI = 123.041) and in vivo models. The antiviral activity of fractions with molecular weight ≥ 10,000 is found to possess more potent antiviral activity than other fractions. SPP inhibits the RSV proliferation and reduces the lung lesions induced by RSV. The mechanism of action involves the inhibition of TLR-3 and TLR-4 in lungs, up-regulation of IFN-γ and IL-2, and down-regulation of TNF-α in serum. It is also shown to improve the body’s immune function. Conclusion SPP has a potential to treat diseases caused by RSV.
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2021
·Vol. 56
·期 13
·8079-8090
·
IF 4.22
Liu Jiali,Yang Qiang,Liu Jikai,Luo He’an
Tungsten trioxide (WO 3 ) has been conceived as a promising photoanode material for photoelectrochemical (PEC) water oxidation. Therefore, many efforts have been made to improve its PEC performances. Herein, a novel heterojunction is fabricated through combining rocksalt CoO (R-CoO) or blende CoO (B-CoO) nanosheets with WO 3 nanoplates using a spin-coating method. The typical type II heterojunctions, e.g., WO 3 /R-CoO and WO 3 /B-CoO, both have exhibited higher photocurrent densities than pristine WO 3 photoanode. The photocurrent densities of WO 3 /R-CoO, WO 3 /B-CoO and WO 3 are 0.53 mA cm −2 , 0.45 mA cm −2 and 0.31 mA cm −2 at 1.23 V vs. reversible hydrogen electrode, respectively. For the WO 3 /R-CoO photoanode, the surface charge separation efficiency is 50.95% and the photoconversion efficiency is 0.062%, which are both higher than the WO 3 and WO 3 /B-CoO photoanodes. The enhanced PEC performances are due to the type II heterojunction between WO 3 and R-CoO (or B-CoO), which facilitates the absorption of visible light and charge transport. The better performance of WO 3 /R-CoO than that of WO 3 /B-CoO may be due to the deeper valence band position of R-CoO. Our work demonstrates that R-CoO (or B-CoO) can couple with WO 3 to form a type II heterojunction to improve the PEC water oxidation performance.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 21
·1-13
·
IF 2.8
Su Congxue,Tao Wenlong,Chen Lianchun,Che Haiyan,Wang Ruijuan,Fan Jun,Qin Xingliu,Chen Zhilin,Fang Liang
Orthorhombic olivine-structured LiTmRO 4 (R = Si, Ge) ceramics were synthesized using a solid-state reaction. Promising microwave dielectric properties of ε r = 8.18, τ f = 13.7 ppm/°C and a high-quality factor ( Q × f ) of 24,274 GHz for LiTmSiO 4 were obtained at 1130 °C, and ε r = 8.67, τ f = − 24.4 ppm/°C and Q × f = 19,231 GHz for LiTmGeO 4 were achieved at 1090 °C. According to the bond valence results, Tm 3+ and Ge 4+ presented a compressed state, but Li + exhibited a strong rattling state in LiTmGeO 4 , which led to a higher ε r than ε theo . The integrated effect of the rattling cations (Li + and Si 4+ ) and a compressed cation (Tm 3+ ) in LiTmSiO 4 resulted in a smaller positive deviation ∆ ε r . The larger packing fraction of LiTmSiO 4 contributed to a higher Q × f than that of LiTmGeO 4 . The R–O bond in both ceramics played a leading role in influencing Q × f according to the Phillips–Van Vechten–Levine chemical bond theory.
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