CERAMICS INTERNATIONAL
·
2018
·Vol. 44
·期 10
·11374-11380
·
IF 3.057
Quanbin Li,Le Zhang,Shuai Wei,Yikun Zhang,Rong Sun,Tianyuan Zhou,Wei Bu,Qing Yao,Zhigang Jiang,Hao Chen
In this paper, weakly agglomerated and well dispersed α-Al 2 O 3 powders were synthesized by a novel spray precipitation method. It was demonstrated that the as-prepared powders exhibited better dispersity than powders from conventional precipitation due to the increased phase contact and reaction area during the precipitation process. The effects of different titration ways, calcination temperature and holding time on the morphology, phase composition and sintering behaviour of Al 2 O 3 powders were systematically investigated. Weakly agglomerated and well crystallized α-Al 2 O 3 powders were obtained when the as-prepared precursors were calcined at 1150 °C for 2 h in air. The average particle size of α-Al 2 O 3 powders with higher sintering activity was approximately 68.6 nm, and the specific surface area was above 22.4 m 2 g −1 .
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2016
·
IF 2.857
Li Zeng,Guowen Zhang,Suyun Lin,Deming Gong
Inhibition of α-glucosidase activity may suppress postprandial hyperglycemia. The inhibition kinetic analysis showed that apigenin reversibly inhibited α-glucosidase activity with an IC50 value of (10.5 ± 0.05) × 10–6 mol L–1, and the inhibition was in a noncompetitive manner through a monophasic kinetic process. The fluorescence quenching and conformational changes determined by fluorescence and circular dichroism were due to the formation of an α-glucosidase–apigenin complex, and the binding was mainly driven by hydrophobic interactions and hydrogen bonding. The molecular simulation showed that apigenin bound to a site close to the active site of α-glucosidase, which may induce the channel closure to prevent the access of substrate, eventually leading to the inhibition of α-glucosidase. Isobolographic analysis of the interaction between myricetin and apigenin or morin showed that both of them exhibited synergistic effects at low concentrations and tended to exhibit additive or antagonistic interaction at high concentrations.
研究领域:
酶动力学
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分子生物学
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植物化学
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糖尿病研究
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药物发现
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2026
·
IF 6.1
Ye Wang,Heshi Tian,Qiannan Li,Zhenhua Ma,Yunna Jia,Xiaojun Liang,Xiuzhen Yu,Xiuyun Jiang,Yunhang Gao
Tylosin (TYL), a widely used macrolide antibiotic in livestock and poultry production, has attracted considerable attention owing to its strong adsorption capacity, persistence, and ecological risks in aquatic and soil environments. Because of their high efficiency and substrate specificity, microbial degradation enzymes are among the most promising agents for removing TYL from the environment. In this study, α/β hydrolase (Rcmd-2829) was expressed and purified from Kurthia gibsonii TYL-A1. The results showed that the optimum reaction conditions for Rcmd-2829 were pH 9.0 and 30°C. Molecular docking analyses, molecular dynamics simulations, and site-directed mutagenesis confirmed the key role of the Ser-102 residue in the catalytic degradation of TYL by Rcmd-2829. Rcmd-2829 retained its high catalytic activity in aquaculture wastewater, removing 83 % of 150 mg/L of TYL within 5 d. This study is the first to elucidate the Ser-102-dependent molecular mechanism underlying TYL degradation by the α/β hydrolase Rcmd-2829, providing a foundation for the development of efficient enzymatic-remediation technologies.
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Science Advances
·
2026
·Vol. 12
·期 2
·
IF 12.5
Hongwei Pang,Andreas Tilgner,Jin Han,Jiazhuo Z. He,Yiqun Wang,Jinli Xu,Bowen He,Qingxin Deng,Ren Yan,Zhu Ran,Xinming Wang,Jiangping Liu,Adeniyi Adesina,Luca Carena,Erik H. Hoffmann,Thomas Schaefer,Davide Vione,Hartmut Herrmann,Sasho Gligorovski
Hydroperoxides (HPs) are potent oxidants that exert a substantial impact on the atmospheric oxidizing capacity. However, a fundamental understanding of the in situ formation of HPs in atmospheric waters remains incomplete and controversial. Here, we report direct observations of HP (hydrogen peroxide, alkyl HP, and peroxycarboxylic acid) formation with quantum yields 10 −4 – 10 −3 , through photochemistry of α-keto acids [α-KAs; glyoxylic acid, pyruvic acid (PA), and 2-ketobutyric acid]. These quantum yields are comparable to reported HP formation rates in cloud and fog waters, suggesting that α-KA photochemistry could contribute 5 to 15% of the observed atmospheric hydrogen peroxide in aqueous phases, based on typical α-KA concentrations (0.1 to 10 μM). The model results showed that the photochemistry of excited triplet 3 PA * contributes ~40 and ~33%, respectively, to the formation of hydrogen peroxide and peroxyacetic acid at pH 2.5. Given the recurrent detection of α-KAs in organic-rich aerosols, this photochemistry represents a notable in situ source of HPs.
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PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS
·
2023
·
IF 1.3
Si Ke,Duanyi Zhang,Yu Li,Ziwei Gong,Pengcheng Tang,Wanxia Tang
Seven novel syringaldehyde α-aminophosphonate derivatives (1–7) were synthesized based on syringaldehyde together with different aryl amines and diethyl phosphite in a one-pot, solvent free, and catalyst free reaction. All of the obtained compounds were characterized by analysis of their 1H NMR and 13C NMR, IR spectra, and FT mass spectra. The UV and fluorescence emission spectra of 1–7 were investigated in the concentration range of 0.1–250 μM. As the results, the maximum emission wavelength of 1–7 was observed between 600 and 700 nm under the exciting wavelength of 250 nm for 1–5 and 300 nm for 6 and 7. The emission intensity is the strongest at a concentration of 60 μM for 2, 3, and 5–7, 30 μM for 1, and 0.1 μM for 4.
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CHINESE SCIENCE BULLETIN
·
2012
·Vol. 57
·期 32
·4210-4214
·
IF 1.321
Zhang LeiLei,Wang ZhongLi,Xu Dan,Xu JiJing,Zhang XinBo,Wang LiMin
Lithium-air (Li-air) batteries have attracted worldwide attention due to their high energy density (11140 Wh kg −1 ) comparable to gasoline. In this work, we have synthesized the α-MnO 2 hollow clews via a simple method and characterized them by X-ray diffraction and scanning electron microscope. Interestingly, cycle performance of Li-air batteries is improved greatly when using the α-MnO 2 hollow clews as the catalyst. The first discharge capacity is 596 mAh g −1 , and the charge capacity is 590 mAh g-1 at the current density of 0.1 mA cm −2 between 2.0 and 4.2 V using the Vulcan XC-72 as the carbon material. Additionally, by re-assembling new batteries with the used lithium foil, separators and cathode separately, we find that the cathode is the key role to end the Li-air battery life.
研究领域:
材料科学
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电化学
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储能技术
·
纳米材料
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Materials Chemistry Frontiers
·
2026
·
IF 8.1
Su-Yun Zhang,Zhu Ding,Zihao Wang,Junzhe Tao,Yu-Jia Zeng
The pursuit of strong, tunable, and thermally robust exchange bias (EB) is not only a fundamental scientific challenge but also a critical prerequisite for advancing spintronic technologies. Bottom-up designed nanostructures offer a versatile platform for engineering EB, owing to their precise control over composition, morphology, and assembly. However, studies on the EB effect in MOF-derived magnetic nanocomposites remains less unexplored. This study reports the EB effect in α-Fe2O3/Pt composites obtained via the pyrolysis of Hofmann-like Pt/Fe MOFs at 450 °C, 550 °C, and 650 °C. The results show that Pt particles are dispersed on the α-Fe2O3 particles, forming α-Fe2O3/Pt composites. The magnetic properties of samples are characterized by zero-field-cooled (ZFC) and field-cooled (FC) susceptibility as well as hysteresis loop measurements. Notably, a significant EB effect is observed in all samples and the optimized sample pyrolyzed at 450 °C exhibits the largest HEB of 2099 Oe at 2 K under a cooling field of 60 kOe, which exceeds that of pure α-Fe2O3 and other α-Fe2O3 based composites. These findings highlight calcination temperature as a critical parameter for tailoring EB effect in MOF-derived oxide/metal nanocomposites.
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JOURNAL OF PHYSICAL CHEMISTRY B
·
2026
·
IF 3.2
Chenning Wang,Xiaolong Yi,Xuan Zhang,Jianxin Mao,Yongtao Wang,Haoran Li,Kenji Mochizuki,Jia Yao
Solventeffects exert a profound influence on reaction rates, selectivity, and reaction pathways. In reactions involving hydrogen bonding, the solvent can directly affect the formation, stabilization, and transformation of key intermediates. We report a 1,1-dimethylguanidine (DMG)-catalyzed aerobic α-hydroxylation of 2-methyl-1-tetralone (MTet) and investigate the microenvironmental regulation of this reaction using trifluoroethanol (TFE) as a model addition. The results demonstrate that the catalytic efficiency of the DMG system is significantly enhanced by TFE, indicating that the reaction is highly sensitive to the local hydrogen-bonding microenvironment. Combined analyses using 1H NMR, NOE spectroscopy, density functional theory (DFT) calculations, and molecular dynamics (MD) simulations reveal that TFE does not directly interact with MTet. Instead, it reorganizes the solvent microenvironment around the catalytic center through hydrogen bonding. In contrast, although hexafluoroisopropanol (HFIP) is capable of forming stronger hydrogen bonds, its excessive binding strength and steric congestion restrict access to the catalytic site, thereby inhibiting the reaction. Ethanol (EtOH), on the other hand, lacks sufficient hydrogen-bonding ability to effectively modulate the reaction pathway. This study elucidates the role of hydrogen-bond-mediated solvent effects in aerobic α-hydroxylation and provides a molecular-level mechanistic basis for regulating multicomponent catalytic reactions through local hydrogen-bonding microenvironments.
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JOURNAL OF ORGANIC CHEMISTRY
·
2025
·
IF 3.6
Lili Duan,Pinyong Zhong,Huatao Shen,Fumin Liao,Kunming Liu,Bin Huang,Nianhua Luo,Jin-Biao Liu
A green and efficient visible-light-driven strategy for direct cyanomethylurea synthesis from α-aminoamides and isothiocyanates via intramolecular oxygen migration is reported. This method merges cyanation and ureidation in a single step, leveraging the amide oxygen as a dual synthon to forge nitrile (C≡N) and urea (C═O) bonds. Operating under metal-free, ambient conditions (room temperature, air, visible light), the protocol accommodates diverse substrates without toxic reagents. Mechanistic studies implicate light-mediated desulfurization and oxygen atom transfer, offering a sustainable strategy for one-step dual functionalization of bioactive molecules.
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NEW JOURNAL OF CHEMISTRY
·
2016
·Vol. 40
·期 12
·10219-10226
·
IF 3.277
Sheng-Ping Guo,Yang Chi,Jian-Ping Zou,Huai-Guo Xue
A new phase of EuZrS3 (α phase) was obtained via a high-temperature solid-state reaction. It crystallizes in the orthorhombic space group Pnma with a = 8.465(3), b = 3.808(1), c = 13.823(4) Å and V = 445.5(2) Å3, belonging to the NH4CdCl3 structure type. Its crystal structure features a 3-D network constructed by EuS8 bicapped trigonal prisms (bctps) and Zr4+ ions that occupy the octahedral cavities. Ultraviolet-visible-near infrared band gap analysis shows an energy gap of 1.09 eV, which is verified by electronic band structure calculations. A typical photoluminescence phenomenon of Eu2+ can be observed at 575 nm. The photocatalytic behavior of rod-like α-EuZrS3 crystals was investigated by decomposing methylene blue under visible light and simulated sunlight irradiation.
研究领域:
材料科学
·
无机化学
·
固体物理
·
光催化
·
半导体材料
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Dandan Liu,Xueyan Li,You Li,Shu Yin,Jiajia Liu,Jiatao Zhang
Highly sensitive and selective gas sensors hold great potential in disease diagnosis. However, the rational design of non-noble-metal-based, high-efficiency sensing materials for trace gas detection remains a crucial challenge. Herein, a chemiresistive sensor that can detect parts per billion (ppb)-level acetone was realized based on three-dimensional (3D) α-Fe2O3/ZnO nanocages, which were achieved by a simple encapsulation and calcination process. In particular, we found that Fe species play an intriguing role in the evolution from Fe-ZIF-8 to heterogeneous α-Fe2O3/ZnO nanocages. α-Fe2O3 functionalization empowered the α-Fe2O3/ZnO nanocage-based sensor with a high response of 45.25, an ultrafast response (7 s) and recovery (6 s) time toward 50 ppm of acetone, a limit of detection (LOD) of 500 ppb, and superior selectivity. Moreover, in situ Fourier transform infrared analysis allowed one to devise of an acetone sensing mechanism for dissociative acetone adsorbed on the α-Fe2O3/ZnO nanocages, involving the first oxidation of acetone to form formate and acetate complexes, followed by further oxidation to CO2 and H2O. The enhanced acetone sensing performance can be attributed to the high specific surface area, abundant oxygen vacancies, well-tuned heterojunction, and optimal acid–base property.
研究领域:
材料科学
·
分析化学
·
生物医学工程
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JOURNAL OF BIOLOGICAL CHEMISTRY
·
2023
·
IF 4.8
Yanjie Gao,Bingfeng Zheng,Shuaiqi Xu,Zhibo Zhao,Wanyue Liu,Tingyu Wang,Manman Yuan,Xueqing Sun,Yang Tan,Qiang Xu,Xingxin Wu
Sustainable TGF-β1 signaling drives organ fibrogenesis. However, the cellular adaptation to maintain TGF-β1 signaling remains unclear. In this study, we revealed that dietary folate restriction promoted the resolution of liver fibrosis in mice with nonalcoholic steatohepatitis (NASH). In activated hepatic stellate cells (HSCs), folate shifted toward mitochondrial metabolism to sustain TGF-β1 signaling. Mechanistically, nontargeted metabolomics screening identified that α-linolenic acid (ALA) is exhausted by mitochondrial folate metabolism in activated HSCs. Knocking down serine hydroxymethyltransferase 2 (SHMT2) increases the bioconversion of ALA to docosahexaenoic acid (DHA) which inhibits TGF-β1 signaling. Finally, blocking mitochondrial folate metabolism promoted liver fibrosis resolution in NASH mice. In conclusion, mitochondrial folate metabolism/ALA exhaustion/TGF-βR1 reproduction is a feedforward signaling to sustain profibrotic TGF-β1 signaling and targeting mitochondrial folate metabolism is a promising strategy to enforce liver fibrosis resolution.
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