Journal of Physical Chemistry C
·
2024
·
IF 3.3
Jindong Bai,Yongsong Wang,Dingbang Yang,Xiao Guo,Yuedong Wang,Tao Xu,Haipeng Xie,Jin Li,Fangping Ouyang,Han Huang
Twisting between layered materials in close proximity causes reconstruction of the electron and crystal structures. The resulting reconstruction has received increasing attention due to the realization of magic-angle superconductivity, moiré excitons, and moiré ferroelectricity. However, demonstrations of such concepts for phonon polarization have been very limited. Here, we reported on the systematic angle-dependent polarized Raman (ADPR) investigations on the twisted bilayer (tBL) α-MoO3 with each layer in a thickness of ∼14 nm. Under 532 and 633 nm excitation, (i) the Raman intensity (I) of representative Mo–Oc symmetric stretching vibration phonon mode (SVPM) at 818 cm–1 and rigid MoO4 translational vibration phonon mode (TVPM) at 156 cm–1 decreases monotonically with the twist angle (φ) increase and (ii) the polar plots of both modes were tuned from axial symmetry to central symmetry by φ increase. The dependence of I and symmetry of both modes on φ were described semiquantitatively by applying the classical Placzek approximation and the interference effect. Our findings unravel the complex interaction between the twisted layer configurations and phonon behaviors of α-MoO3, providing valuable insights into the anomalous phonon polarization responses in low symmetric two-dimensional materials and potentially facilitating the development of technologies based on tunable phonon polarization.
研究领域:
材料科学
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凝聚态物理
✓ 已验证
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 22
·8097
·
IF 3.748
Hongyun Wang,Haijun Cheng,Fang Lai,Deyuan Xiong
Copper(II)-containing aluminum phosphate material (CuAPO-5) was synthesized hydrothermally and used as a multiphase catalyst for the oxidation of α-pinene to verbenone. The catalysts were analyzed using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area techniques, X-ray photoelectron spectroscopy (XPS), and ammonia temperature programmed reduction (NH3-TPD). Scanning electron microscopy (SEM), X-ray energy spectrometry (EDS), inductively coupled plasma emission spectroscopy (ICP-OES), Fourier infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-vis) were performed to characterize the material. The effects of reaction temperature, reaction time, n(α-pinene)/n(TBHP), and solvent on the catalytic performance of CuAPO-5 were investigated. The results show that all the prepared catalysts have AFI topology and a large specific surface area. Copper is evenly distributed in the skeleton in a bivalent form. The introduction of copper increases the acid content of the catalyst. Under the optimized reaction conditions, 96.8% conversion of α-pinene and 46.4% selectivity to verbenone were achieved by CuAPO-5(0.06) molecular sieve within a reaction time of 12 h. CuAPO-5(0.06) can be recycled for five cycles without losing the conversion of α-pinene and the selectivity to verbenone.Keywords:CuAPO-5;α-pinene;selective oxidation;verbenone
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
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2020
·Vol. 10
·期 3
·302
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IF 3.52
Meng Guo,Zhen Wei,Jianming Yang,Zunyuan Xie,Weiqiang Zhang
In the palladium-catalyzed C−C coupling reaction, electron-rich phosphine ligands and a catalytic amount of catalyst loading are required in most cases. Herein, a bench-stable, easily modified and less toxic alkynone was utilized in palladium-catalyzed Sonogashira coupling to replace conventional phosphine ligands. With 1-(4-methoxyphenyl)-3-phenyl-2-yn-1-one (L2) as the ligand, catalyst loading was reduced to 5-10 ppm. In this newly developed catalytic system, a variety of (hetero)arene iodines and alkynes could be tolerated, resulting in good yields of the corresponding cross-coupling products.Keywords:α;β-alkynone;Pd-catalyzed C−C coupling;π-acidicity
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
BIOMEDICAL CHROMATOGRAPHY
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2022
·Vol. 37
·期 3
·e5571
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IF 1.911
Shuang Guo,Shuo Liu,Jing Meng,Dongyu Gu,Yi Wang,Dajun He,Yi Yang
Morus alba leaves are a natural product with great antidiabetic potential. However, the therapeutic efficacy of natural products is usually achieved through the interaction of active compounds with specific targets. Among them, active compounds with multi-target therapeutic functions are more effective than single-target enzymes. In this study, a bienzyme system was constructed by co-immobilizing α -amylase and α -glucosidase onto Fe 3 O 4 for affinity screening of dual-target active components in the complex extract from M. alba leaves. As a result, a potential active compound was selectively screened by ligand fishing, separated by high-speed countercurrent chromatography using a solvent system of ethyl acetate– n -butanol–water (3:2:5, v/v), and identified as rutin. In addition, the result of molecular docking showed that rutin could interact with the active center of α -amylase and α -glucosidase through multiple hydrogen bonds, van der Waals forces, etc. to play an inhibitory role. These results demonstrate the effectiveness of the polydopamine magnetically immobilized bienzyme system for dual-target affinity screening of active substances. This study not only reveals the chemical basis of the antidiabetic activity of M. alba leaves from a dual-target perspective, but also promotes the progress of multitarget affinity screening.
研究领域:
药理学
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生物化学
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分析化学
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天然产物
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糖尿病研究
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产品关联
DOI
PubMed
高影响因子
Asian Journal of Organic Chemistry
·
2023
·Vol. 12
·期 5
·e202300015
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IF 2.7
Yu-Tong Duan,Zhong-Xia Wang
Graphical Transition-metal-free reaction of oxindoles with primary or secondary alcohols in the presence of LiO t Bu affords α-C-alkylated oxindoles. Transition-metal-free α-C-alkylation of oxindoles with alcohols was performed. The reaction requires the presence of LiO t Bu and proceeds under thermal conditions. The method exhibits a wide scope of substrates. Both primary and secondary aliphatic and aromatic alcohols can be employed as the alkylating reagents. Oxindole and various 1-alkyl- or 1-aryl-substituted oxindoles can be alkylated. The mechanistic studies show that the reaction may involve both free radical and aldol condensation/MPV processes.
研究领域:
有机化学
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合成化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
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2020
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IF 4.335
Xiao-Yu Zhan,Hua Zhang,Yu Dong,Jian Yang,Shuai He,Zhi-Chuan Shi,Lei Tang,Ji-Yu Wang
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies revealed that hexafluoro-2-propanol also served as a hydrogen source in the process.
研究领域:
有机化学
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催化化学
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合成化学
✓ 已验证
DOI
高影响因子
BIOMATERIALS
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2018
·
IF 8.806
Chong Zhang,Jingsong Yuan,Jianhua Lu,Yingqin Hou,Wei Xiong,Hua Lu
s The development of high-performance nonfouling polymer surfaces for implantable medical devices and therapeutic nanomaterials is of great importance. Elaborating the relationship of polymer structural characteristics and the resulted surface properties can offer useful guidance toward ideal biointerfaces . In this work, we investigate the effects of the helical conformation and anchoring orientation of poly(α-amino acid)s (PαAAs) to produce advanced nonfouling surfaces. By using the neutral poly(γ-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)esteryl glutamates) (P(EG 3 Glu)s) as a model system, the adsorption kinetics are monitored by ex-situ variable angle spectroscopic ellipsometry and in-situ quartz crystal microbalance with dissipation . It is found that the polymers adopting a rigid rod-like α-helical conformation can self-assemble more rapidly to produce denser adlayers, and generate significantly improved nonfouling surfaces compared to those flexible polymer analogues including the widely used antifouling polymer PEG . Moreover, the surface properties can be further enhanced by using the antiparallel orientated helical P(EG 3 Glu)s. Most importantly, the insights gained from the P(EG 3 Glu) model system are successfully applied to the generation of ultra-low-fouling surfaces using zwitterionic PαAAs brushes, underscoring the generality of the approach. Particularly, the surface based on the antiparallel aligned zwitterionic helical PαAAs exhibits ∼98–99% reduction of human serum adsorption relative to the bare gold, and gives almost no adhesion of mouse platelet. Taken together, this work depicts an extremely simple yet highly effective approach to manipulate surface properties for numerous applications in biomaterial interfaces, diagnostics, and biosensors.
研究领域:
生物材料
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生物医学工程
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界面科学
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产品关联
DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2021
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IF 4.821
Huinan Sun,Fangchao Yin,Xuefeng Liu,Ting Jiang,Yaohong Ma,Guangheng Gao,Jianguo Shi,Qiongzheng Hu
The detection of α-glucosidase (AGLU) inhibitors is critical for the screening of anti-diabetic drugs. In this study, we first demonstrate a liquid crystal (LC)-based assay to detect anti-diabetic drugs. When the solution of non-ionic surfactant dodecyl α-D-glucopyranoside (DDG) is introduced onto the LCs, self-assembled monolayers are formed at the aqueous/LC interface, which induces the perpendicular orientation of LC molecules at the interface. Accordingly, the LCs show a dark image. However, when a mixture of AGLU and DDG is introduced onto the LCs, a bright image is observed due to enzymatic hydrolysis of DDG by AGLU, which prevents formation of the surfactant monolayers and results in the planar or tilted orientation of LC molecules at the interface. Using the LC-based AGLU assay, the detection of three AGLU inhibitors that are popular anti-diabetic drugs including acarbose, migliol, and voglibose is demonstrated. In addition, the linear detection ranges and the detection limits of these drugs are also determined. This method provides a simple and powerful strategy to rapidly and accurately detect AGLU inhibitors, which is very promising in the applications of screening anti-diabetic drugs.
研究领域:
药学
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生物化学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2012
·Vol. 108
·期 4
·961-965
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IF 1.63
Shao Hao,Zhang Xuebin,Chen Fanyan,Liu Shasha,Ji Yi,Zhu Yajun,Feng Yi
In this paper, smooth α -Fe 2 O 3 nanotubes have been successfully synthesized by electrospinning of ferric nitrate–polyvinyl alcohol solution followed by calcination in air. The morphologies and structures of the samples were characterized by transmission electron microscopy, scanning electron microscopy and X-ray diffraction. The catalytic properties were studied by differential thermal analysis and thermogravimetric analysis. The results indicated that the as-prepared α -Fe 2 O 3 nanotubes showed a continuous morphology and an extremely high degree of crystallization. The average inner and outer diameters of the obtained α -Fe 2 O 3 nanotubes were about 60 nm and 100 nm, respectively. The obtained α -Fe 2 O 3 nanotubes were able to lower the temperature of the high-temperature thermal decomposition of ammonium perchlorate, while they had little effect on the crystallographic phase transformation and the low-temperature thermal decomposition.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
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2021
·Vol. 39
·期 10
·2852-2856
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IF 6
Peng Zhou,Zixian Li,Yanzhi Lu,Jie Kong,Jun Ling
Main observation and conclusion Block copolymers not only combine properties of different segments but also generate new application prospects. Poly(α-amino acid)- b -poly(tetrahydrofuran)- b -poly(α-amino acid) (PAA-PTHF-PAA) is one of the copolymers. In this contribution, di-hydroxyl-ended HO-PTHF-OH is transferred into di-oxyamino-ended H 2 NO-PTHF-ONH 2 quantitatively, which is used as a macroinitiator to polymerize sarcosine N -thiocarboxyanhydride (Sar-NTA) and N -phenyoxycarbonyl N -ε-carbobenzyloxy- D -lysine (ZDL-NPC). Well-defined triblock PAA-NHO-PTHF-ONH-PAA is produced with high molecular weight (up to 25.3 kg/mol) and narrow dispersity. The amphiphilic PSar-NHO-PTHF-ONH-PSar (STS) self-assembles into micelles with uniform diameters of 30—40 nm according to DLS. Owing to oxygen amide groups inside the backbone of these copolymers, the polyether-poly(amino acid)s block copolymers are cleavable under an acidic environment and therefore have potential applications in smart biomedicine and engineering.
研究领域:
高分子化学
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生物材料
·
生物医药
✓ 已验证
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2023
·
IF 8.1
Hongjuan Xia,Chenghao Lv,Yuting Lu,Chaoxi Zeng,Si Qin,Meng Shi
Astilbin, a natural flavonoid, possesses multiple functionalities, while the poor bioavailability seriously restricts its application in functional food and medicine. Therefore, in this study, a natural deep eutectic solvent (NaDES) with choline chloride: lactic acid (CHCL-LAC) is selected to deliver astilbin by evaluating the bioaccessibility and antioxidant capacity during in vitro gastrointestinal digestion, and the inhibitory effect with underlying mechanism of astilbin-CHCL-LAC against α-amylase/α-glucosidase were investigated. The CHCL-LAC showed significant high astilbin bioaccessibility (84.1% bioaccessible) and DPPH and ORAC antioxidant capacity with 75.7% and 57.7% respectively after 3 h in vitro digestion, which may be attributed by hydrogen bond based supramolecule formed between astilbin and CHCL-LAC. Moreover, significant inhibitions of astilbin-CHCL-LAC on α-amylase (IC 50 of 0.67 g/L) and α-glucosidase (IC 50 of 0.64 g/L) were observed in mixed competitive and non-competitive manners. The dominant binding force between enzymes and astilbin were the hydrogen and hydrophobic interaction. This is the first time that the underlying mechanisms for astilbin delivered by NaDESs were revealed, suggesting that CHCL-LAC-based NaDESs are promising ready-to-use vehicles of natural inhibitors for carbohydrate-hydrolyzing enzymes.
研究领域:
药理学
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食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Natural Product Communications
·
2018
·
IF 0.809
Yike Yue,Yongsheng Chen,Sheng Geng,Guizhao Liang,Benguo Liu
Fisetin is a flavonoid widespread in vegetables, fruits and medicinal plants. The in vitro antioxidant and α-glucosidase inhibitory activities of fisetin were systemically investigated in this study. The DPPH and ABTS radical scavenging performance of fisetin was higher than that of BHA. In the ORAC and PSC assays, fisetin also exhibited strong antioxidant activity. The α-glucosidase inhibitory activity of fisetin (IC50, 9.38±0.35 μg/mL) was significantly superior to that of acarbose (IC50, 1.07±0.15 mg/mL). Its inhibition type was determined to be a mixed competitive and non-competitive inhibition mode. Molecular docking analysis suggested it could exert the α-glucosidase inhibitory role by forming hydrogen bonds with the TRP391, ASP392, ARG428 and ASP568 residues of α-glucosidase.
研究领域:
药理学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）