LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Yanglin Ji,Dong Liu,Yan jin,Juan Zhao,Jiang Zhao,Heyu Li,Liwei Li,Hua Zhang,Hao Wang
The inhibition of glycosidase activity is regarded as an effective treatment for diabetes mellitus. Bilberry ( Vaccinium myrtillus L.) fruit has a high content of anthocyanins with various biological activities. The objective of this study was to investigate the inhibitory activity of anthocyanin-rich bilberry extract (BE) on α-glucosidase and α-amylase and their interaction mechanisms in vitro . The IC 50 values of BE with regard to α-glucosidase and α-amylase inhibition were 0.31 ± 0.02 and 4.06 ± 0.12 mg/mL, respectively. The enzyme kinetics revealed that BE acts as a mixed-type inhibitor against α-glucosidase and α-amylase. Moreover, the fluorescence of two glucosidases showed significant quenching by BE. FTIR spectra and differential scanning calorimetry (DSC) indicated that BE changed the enzyme structure and decreased its stability. A morphological observation of starch granules found that BE inhibited the activity of α-amylase to postpone the hydrolysis of starch. Furthermore, the in vivo study further showed that BE had a hypoglycaemic effect. The most suitable conformation (main anthocyanidins of BE) and optimal binding site (α-glucosidase, α-amylase) were assayed by molecular docking. In conclusion, this study revealed that BE could be a potential glycosidase inhibitor.
研究领域:
药理学
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生物化学
·
营养学
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产品关联
DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2015
·Vol. 81
·期 6
·
IF 3.668
Zhoukun Li,Jiale Wu,Biying Zhang,Fei Wang,Xianfeng Ye,Yan Huang,Qiang Huang,Zhongli Cui
A novel α-amylase, AmyM, was purified from the culture supernatant of Corallococcus sp. strain EGB. AmyM is a maltohexaose-forming exoamylase with an apparent molecular mass of 43 kDa. Based on the results of matrix-assisted laser desorption ionization–time of flight mass spectrometry and peptide mass fingerprinting of AmyM and by comparison to the genome sequence of Corallococcus coralloides DSM 2259, the AmyM gene was identified and cloned into Escherichia coli. amyM encodes a secretory amylase with a predicted signal peptide of 23 amino acid residues, which showed no significant identity with known and functionally verified amylases. amyM was expressed in E. coli BL21(DE3) cells with a hexahistidine tag. The signal peptide efficiently induced the secretion of mature AmyM in E. coli. Recombinant AmyM (rAmyM) was purified by Ni-nitrilotriacetic acid (NTA) affinity chromatography, with a specific activity of up to 14,000 U/mg. rAmyM was optimally active at 50°C in Tris-HCl buffer (50 mM; pH 7.0) and stable at temperatures of <50°C. rAmyM was stable over a wide range of pH values (from pH 5.0 to 10.0) and highly tolerant to high concentrations of salts, detergents, and various organic solvents. Its activity toward starch was independent of calcium ions. The Km and V max of recombinant AmyM for soluble starch were 6.61 mg ml−1 and 44,301.5 μmol min−1 mg−1, respectively. End product analysis showed that maltohexaose accounted for 59.4% of the maltooligosaccharides produced. These characteristics indicate that AmyM has great potential in industrial applications.
研究领域:
生物化学
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酶学
·
微生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Jiabao Zang,Haifeng Li,Qingzhi Zhu,Ziheng Wang,Hubuli Bazaerbieke,Li Sun,Meijie Zhang
There are few reports about the electromagnetic wave (EMW) absorption properties of α−SiC based composites, and almost all of them focus on β−SiC polymorphs. In this study, α−SiC p /α−SiC nw /SiO 2 /C hybrid composites (sample SiC−C1500) with heterostructure α−SiC nanowires (α−SiC nw ) of multiple interfaces 4H−SiC/6H−SiC/SiO 2 /C were successfully prepared using mixed powder (α−SiC+m−SiO 2 +C) as raw material based on the heterogeneous nucleation−growth mechanism, and their microwave absorption properties were investigated. Meanwhile, the samples SiC−V2150 and Si−C1500 were obtained by vacuum calcination (α−SiC+m−SiO 2 +C) at 2150 0 C and carbothermal reduction (Si+m−SiO 2 +C) at 1500 0 C, respectively, and their phase compositions were α−SiC p /C and β−SiC p /β−SiC nw /SiO 2 /C, respectively. The sample SiC−C1500 exhibited excellent EMW absorption properties, with a minimum reflection loss (RL min ) value of −18.37 dB at a thickness of 1.3 mm, and a maximum effective absorption bandwidth (EAB max ) value of 4.9 GHz at a thickness of 1.5 mm. In contrast, the EMW absorption performance of the samples SiC−V2150 and Si−C1500 was obviously poor, which was consistent with the RCS (Radar Cross−Section) simulation results. The formation of α−SiC p /α−SiC nw /SiO 2 /C composites (sample SiC−C1500) containing 4H−SiC/6H−SiC/SiO 2 /C multi-interfaces heterostructure α−SiC nanowires (α−SiC nw ) was analyzed. The excellent EMW absorption performance of SiC−C1500 sample could be attributed to the effective regulation of α polymorphs, nanowire heterostructure, multi−component hybridization. This study supplies a helpful experience and reference for improving the high temperature EMW absorption performance of SiC matrix composites.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED PHYSICS
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2014
·Vol. 115
·期 17
·
IF 2.185
Li S. J.,Li D.,Jiang J. J.,Liu G. B.,Ma S.,Liu W.,Zhang Z. D.
Growth process and magnetic properties of PbO-type α-Fe x Se nanostructures with shape changing from nanocacti to nanopetals and then to nanosheets are investigated. With iron acetylacetonate [Fe(acac) 3 ] and Se powder as raw materials, the diffusion process of Fe atoms dominates the synthesis of α-Fe x Se nanocacti following phase transitions from FeSe 2 to Fe 3 Se 4 and finally to α-Fe x Se. When a mixed solution containing Se precursor and Fe(acac) 3 was used as the raw material, the formation of FeSe 2 and Fe 3 Se 4 can be avoided and, bended α-Fe x Se nanopetals can be prepared at 345 °C, which became flat nanosheets with a [001] preferred orientation as extending the reaction time from 1 to 4 h. No superconducting transition occurs in the α-Fe x Se (0.84 ≤ x ≤ 1.05) nanostructures due to composition heterogeneity or size effect. Magnetic measurements indicate that an antiferromagnetic component with a Néel point at about 45 K dominates the magnetic properties of the α-Fe 0.87 Se nanosheets.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Arabian Journal of Chemistry
·
2023
·
IF 6
Haijun Cheng,Min Liang,Suyi Dai,Xianrui Lu,Qilin Huang,Fang Lai,Li Ma,Weiguang Li,Xiongmin Liu
α-Pinene, β-pinene and turpentine are renewable resources that are widely used in fine chemicals, fuels and other applications, and the safety of their production, transport and use should be considered. In this work, the characteristics and hazardous of the oxidation process of α-pinene, β-pinene and turpentine were investigated by using a novel mini closed pressure vessel testing system (MCPVT). The oxidation products were resolved by gas chromatography-mass spectrometry (GC–MS). The results showed that α-pinene, β-pinene and turpentine were stable under nitrogen atmosphere and very active chemically under oxygen atmosphere. The activation energies ( E a ) of α-pinene, β-pinene and turpentine were calculated to be 78.87, 109.69 and 98.82 kJ/mol, respectively, using pressure–time (P-t) curves. So, the reaction activity sequence was α-pinene > turpentine > β-pinene. The peroxide concentrations of α-pinene (363 K), β-pinene (358 K) and turpentine (363 K) could reach 81.94, 84.70 and 75.76 mmol/kg, respectively, at relatively low temperatures. 0.6 g of α-pinene exploded at a system temperature of 369 K and an oxygen pressure of 1.23 MPa. 0.6 g of β-pinene also exploded at a system temperature of 373 K and an oxygen pressure of 1.27 MPa. 0.4 g of turpentine experienced thermal runaway at a system temperature of 384 K and an oxygen pressure of 0.81 MPa. The major oxidation products of α-pinene are α-campholenaldehyde, laevo-pinocarveol, verbenol, verbenone, bicyclo (3.1.1)heptane-2, 3-diol, 2, 6, 6-trimethyl, 2-cyclohexen-1-ol, 2-methyl-5-(1-methylethenyl)-, (1R,5R)-rel-, cyclobutaneacetic acid, 3-acetyl-2, 2-dimethyl, myrtenol and myrtenal. The major thermal runaway products are water, ethanol, acetone, acetic acid, 2-pentanone, propyl acetate, toluene, cymene and methylacetophenone. The major oxidation products of β-pinene are nopinone, laevo-pinocarveol, pinocarvone, myrtenol, myrtenal and perillyl alcohol. The major thermal runaway products are water, ethanol, acetone, n-ethyl propanoate, toluene, butyl acetate, cymene, apocamphor, nopinone, bornyl formate, methylacetophenone and dihydronopol. The oxidation products and thermal runaway products of pinene were significantly different. Possible reaction pathways for α-pinene and β-pinene are proposed.
研究领域:
化学工程
·
安全科学
✓ 已验证
产品关联
DOI
高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2025
·
IF 6.1
Jie Tang,Bairu Chen,Fang Yu,Long Xu,Muxin Yu,Chunji Wang,Fang Zhang,Li Zhang,Yujia Yang,Jiani Hou,Xingfei Li,Weihao Xu,Nenghua Zhang
Increasing evidence links hearing loss to environmental pollutant exposure, with cochlear hair cell being a key target. Bisphenol A (BPA) has been suggested to cause ototoxicity, but its mechanism is not fully understood. In this study, cell viability was assessed by varying concentrations of BPA (0–150 μM) exposed to mouse cochlear hair cells (HEI-OC1), followed by RNA transcriptome sequencing to identify the possible molecular mechanisms. Results showed that BPA above 50 μM reduced cell viability in a dose-dependent manner. RNA sequencing identified 1764 differentially-expressed genes, comprised of 1152 up-regulated and 612 down-regulated genes. Notably, estrogen receptor-related genes were enriched, with a marked up-regulation of estrogen receptor α (ER-α) at both mRNA and protein levels. GO and KEGG analyses revealed the main pathway involvement for oxidative damage, lipid metabolism, protein phosphorylation, and DNA damage. STRING analyses constructed gene networks to identify functionally interacting genes correlated with pyroptotic pathways. BPA exposure induced pyroptosis-like morphological changes characterized by cell swelling, rounding, and membrane blebbing. Increased intracellular ROS and mitochondrial superoxide (MitoSOX) levels, reduced mitochondrial membrane potential ( ΔΨm ), and elevated intracellular calcium (Ca²⁺) levels were observed. Flow cytometry showed an increased proportion of apoptotic and necrotic cells. Pyroptosis-related genes, including caspase-3, caspase-8, caspase-9, and GSDME, were down-regulated, while IL-1β and IL-18 were up-regulated. Protein expressions of caspase-3, caspase-8, caspase-9, and GSDME were decreased, while cleaved caspase-3 and N-terminal GSDME (GSDME-NT) were increased. Furthermore, ROS inhibitor N-acetylcysteine (NAC) and the ER-α antagonist fulvestrant alleviated BPA-induced cell death, and suppressed the protein expressions of the pyroptotic pathway. These results demonstrate that BPA exposure induces ototoxicity possibly through activating ER-α and triggering mitochondrial ROS that contributes to pyroptosis.
研究领域:
毒理学
·
耳科学
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分子生物学
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环境健康
·
细胞死亡机制
·
内分泌干扰物
✓ 已验证
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Xia Cheng,Xinyan Xiao,Fei Wang,Ting Lu,Yu Zhang
Photocatalysis is extensively implemented in organic pollutant degradation, and the critical point is to develop outstanding and stable photocatalysts. Herein, the synthesis of coral reef-like α-Bi2O3/BiOBr heterostructure photocatalysts involves the in situ growth of BiOBr nanosheets onto α-Bi2O3, with the latter derived through calcination utilizing a bismuth-based metal–organic framework (CAU-17) as the precursor. Under simulated sunlight, the 20% α-Bi2O3/BiOBr heterojunction degraded nearly 97.7% of RhB in 60 min, while pure α-Bi2O3 and BiOBr nanosheets degraded only 7.8 and 65.3%, respectively. Furthermore, the 20% α-Bi2O3/BiOBr nanocomposite exhibited superior recycling stability, degrading 86.6% RhB after four cyclic experiments. This is attributed to the fact that the nanoscale α-Bi2O3 material obtained by calcination can retain the exoteric diffusion channels of CAU-17, making α-Bi2O3/BiOBr heterojunctions have an enormous specific surface area, providing more adsorption sites and promoting their photocatalytic capacity. Free radical capture tests and electron paramagnetic resonance measurements indicated that h+ and •O2– were the primary active substances during photodegradation. On the basis of that, a feasible photodegradation mechanism of type II α-Bi2O3/BiOBr heterojunctions was proposed. This study opens up the possibility of designing type II heterojunctions with MOFs as precursors for dye degradation.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Qingyong Tian,Wei Wu,Lingling Sun,Shuanglei Yang,Mei Lei,Juan Zhou,Ying Liu,Xiangheng Xiao,Feng Ren,Changzhong Jiang,Vellaisamy A. L. Roy
Heterogeneous photocatalysis is of great interest for environmental remediation applications. However, fast recombination of photogenerated electron–hole pair and a low utilization rate of sunlight hinder the commercialization of currently available semiconductor photocatalysts. In this regard, we developed a unique ternary single core-double shell heterostructure that consists of α-Fe2O3@SnO2@Cu2O. This heterostructure exhibits a tube-like morphology possessing broad spectral response for the sunlight due to the combination of narrow bandgap and wide bandgap semiconductors forming a p–n heterojunction. To fabricate such a short nanotube (SNT), we used an anion-assisted hydrothermal route for deposition of α-Fe2O3, a seed-mediated deposition strategy for SnO2, and finally an aging process to deposit a Cu2O layer to complete the tube-like ternary α-Fe2O3@SnO2@Cu2O single core-double shell heterostructures. The morphology, composition, and photocatalytic properties of those ternary core–shell–shell heterostructures were characterized by various analytical techniques. These ternary heterostructures exhibited enhanced photocatalytic properties on the photodegradation of the organic dye of Rhodamine B (RhB) under simulated sunlight irradiation. The origin of enhanced photocatalytic activity is due to the synergistic effect of broad spectral response by combining narrow bandgap and wide bandgap semiconductors and, hence, an efficient charge separation of photogenerated electron–hole pairs facilitated through the p–n heterojunction. Furthermore, our unique structure provides an insight on the fabrication and controlled preparation of multilayer heterostructural photocatalysts that have intriguing properties.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2023
·
IF 7.2
Yuan Zhao,Qingshuang Wang,Dongming Yin,Shouliang Li,Chunli Wang,Long Liang,Shaolei Zhao,Chunmin Zhang,Limin Wang,Yong Cheng
The high dehydrogenation temperature of α-AlH 3 has always been an important factor hindering its development. In order to solve this problem, we synthesize Bi-MOF by hydrothermal method and burn it under inert gas to obtain Bi@C, which is used as catalyst ( x Bi@C, x = 3, 5 and 7 wt%) to improve the hydrogen desorption performance of α-AlH 3 . The dehydrogenation onset temperature of α-AlH 3 +5 wt% Bi@C drop to 80.4 °C, which is reduced by 43.4% compared with pure α-AlH 3 . At 120 °C, it can provide a stable hydrogen capacity of 7.45 wt%. In contrast, pure α-AlH 3 releases only 6.66 wt% hydrogen at the same time. The density functional theory calculations further indicate that the existence of Bi@C catalyst can make the Al–H bond length increase, more conducive to the release of hydrogen. The results show that the synergistic effect of Bi and porous carbon in Bi@C materials can improve the hydrogen desorption kinetics of α-AlH 3 , providing a good prospect for the application of α-AlH 3 in hydrogen storage .
研究领域:
材料科学
·
氢能存储
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2015
·
IF 3.391
Xi Peng,Guowen Zhang,Yijing Liao,Deming Gong
α-Glucosidase is a therapeutic target for diabetes mellitus, and α-glucosidase inhibitors play a vital role in the treatments for the disease. As a kind of potentially safer α-glucosidase inhibitor, flavonoids have attached much attention currently. In this study, kaempferol was found to show a notable inhibition activity on α-glucosidase in a mixed-type manner with IC 50 value of (1.16 ± 0.04) × 10 −5 mol L −1 . Analyses of fluorescence, circular dichroism and Fourier transform infrared spectra indicated that kaempferol bound to α-glucosidase with high affinity which was mainly driven by hydrogen bonds and van der Waals forces, and this binding resulted in conformational alteration of α-glucosidase. Further molecular docking study validated the experimental results. It was proposed that kaempferol may interact with some amino acid residues located within the active site of α-glucosidase, occupying the catalytic center of the enzyme to avoid the entrance of p-nitrophenyl-α- d -glucopyranoside and ultimately inhibiting the enzyme activity.
研究领域:
药理学
·
生物化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2014
·
IF 2.538
Chang Su,Changbai Liu,Li Liu,Mucui Ni,Haiying Li,Xiaoqing Bo,Lili Liu,Xiao Chi
Pure and 3 wt% Sm-doped α-Fe 2 O 3 nanotubes are prepared via a typical electrospinning technology and calcination procedure. The characteristic and morphology of the synthesized nanotubes are investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM). Compared with pure α-Fe 2 O 3 nanotubes, 3 wt% Sm-doped α-Fe 2 O 3 nanotubes display enhanced gas-sensing properties. The response of 3 wt% Sm-doped α-Fe 2 O 3 nanotubes is 33–50 ppm acetone, which is 13 times larger than that of pure α-Fe 2 O 3 nanotubes. The lowest detection limit of acetone is 500 ppb to which the response is 2.3 at the optimum operating temperature of 240 °C. The response and recovery times are about 6 and 11 s to 50 ppm acetone, respectively. In addition, 3 wt% Sm-doped α-Fe 2 O 3 nanotubes exhibit good selectivity and long term stability.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2015
·
IF 3.391
Xueke Liu,Zhigang Shen,Peng Wang,Chang Liu,Guojun Yao,Jiayuan He,Donghui Liu,Zhiqiang Zhou
Isomerization of chiral pesticides in residue analysis has not drawn much attention which can cause wrong decisions on the enantioselective environmental behavior. A residue analysis method for α-cypermethrin and its three acid metabolites, cis/trans-3-(2,2-dichlorovinyl)-2,2-dimethyl cyclopropanecarboxylic acid (cis/trans-DCVA) and 3-phenoxybenzoic acid (3-PBA), in foods such as chicken, honey, milk and pork has been established, in which the isomerization of α-cypermethrin was minimized. The target compounds were determined by GC–ECD after a derivatization reaction with 1,1,1,3,3,3-hexafluoroisopropanol. The conditions of the method were optimized by Taguchi orthogonal experiment. Under the optimized conditions, good linearity was obtained with correlation coefficients ranging from 0.9964 to 0.9998. The limits of detection were 0.001–0.005 mg kg −1 . The recoveries were 70.9–114.9% with relative standard deviations of 0.6–15%. In addition, ratios of isomerization ranged only from 2.3% to 7.0%. This method was applied in commercial animal food products.
研究领域:
分析化学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）