CERAMICS INTERNATIONAL
·
2013
·
IF 1.789
Lin Gan,Zhi-Yong Mao,Yi-Fei Wang,Fang-Fang Xu,Ying-Chun Zhu,Qing Huang,Xue-Jian Liu
Cerium-doped Ca–α-SiAlON phosphors with Ca n −1.5 x Si 12− m − n Al m + n O n N 16− n :Ce x ( m =2 n , 0.8≤ m ≤2.4, and 0.02≤ x ≤0.40) nominal compositions have been synthesized by gas pressure sintering (GPS). The photoluminescence (PL) properties were studied in relation to phase composition, particle morphology , and microstructure. Continuous addition of Ce rare-earth (RE) could enhance the emission intensity of phosphors, which was partially attributed to the formation of increased amount of planar defects where dense doping of Ce ions is achieved. Such enhancement could hold up to x =0.32, above which the emission intensity fell slightly due to the formation of more secondary phases and a surface glassy phase rather than concentration quenching. Finally, possible ways to improve the luminescence properties of Ce-doped α-SiAlON phosphors were discussed through tailoring the composition and microstructure.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Royal Society Open Science
·
2018
·Vol. 5
·期 6
·
IF 2.504
Xiangyun Han,Xi Zhang,Lei Zhang,Mei Pan,Jinlong Yan
The photodegradation of benzothiazole (BTH) in wastewater with the coexistence of iron oxides and oxalic acid under UV light irradiation was investigated. Results revealed that an effective heterogeneous photo-Fenton-like system could be set up for BTH abatement in wastewater under UV irradiation without additional H2O2, and 88.1% BTH was removed with the addition of 2.0 mmol l−1 oxalic acid and 0.2 g l−1 α-Fe2O3 using a 500 W high-pressure mercury lamp (365 nm). The degradation of BTH in the photo-Fenton-like system followed the first-order kinetic model. The photoproduction of hydroxyl radicals (·OH) in different systems was determined by high-performance liquid chromatography. Identification of transformation products by using liquid chromatography coupled with high resolution tandem mass spectrometry provided information about six transformation products formed during the photodegradation of BTH. Further insight was obtained by monitoring concentrations of the sulfate ion (SO42−) and nitrate ion (NO3−), which demonstrated that the intermediate products of BTH could be decomposed ultimately. Based on the results, the potential photodegradation pathway of BTH was also proposed.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GLYCOCONJUGATE JOURNAL
·
2016
·Vol. 33
·期 2
·147-157
·
IF 1.828
Zhang Wuxia,Li Peng,Song Dan,Niu Hong,Shi Songshan,Wang Shunchun,Duan Jinyou
Radix Paeoniae Alba is widely used in Chinese traditional medicine to treat various diseases such as gastrointestinal disorders, cancer, and other diseases. In this study, two polysaccharides RPAPW1 and RPAPW2 were isolated from Radix Paeoniae Alba by DEAE-52 cellulose chromatography and G-25 sephadex. According to physicochemical methods, NMR and methylation analysis, RPAPW1 and RPAPW2 were established to be α-glucans consisting of predominant 4-linked α- Glc residues branched at O-6 and contained trace amount of protein and uronic acid. Immunological tests indicated that RPAPW1, RPAPW2 and could promote splenocyte proliferation and RAW264.7 phagocytic activity. In vitro , RPAPW1 and RPAPW2 elicited a week reducing power, DPPH scavenging activity and could not protect the PC12 cells from H 2 O 2 damage. These data implied polysaccharides RPAPW1 and RPAPW2 had the potential to be a natural immunopotentiating and antioxidant supplement for preparing functional foods and nutraceuticals.
研究领域:
中药学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Functional Foods
·
2019
·
IF 3.197
Yuxue Zheng,Wenhan Yang,Weixuan Sun,Shiguo Chen,Donghong Liu,Xiangli Kong,Jinhu Tian,Xingqian Ye
The inhibitory mechanism of chlorogenic acid (CHA) against porcine pancreatic α-amylase (PPA) was examined by enzyme kinetic analysis, circular dichroism, fluorescence quenching and molecular docking. As a result, CHA showed a mixed-type inhibitory action on PPA, with the IC 50 value of 0.498 ± 0.013 mg/mL. Analysis of fluorescence and circular dichroism spectra confirmed that CHA altered the secondary structure of PPA, by interacting with the amino acid residues around or distant from the catalytic site of PPA, mainly through hydrogen bonds, and this interaction was closely associated with the enzyme’s activity. Molecular docking indicated that the best pose between CHA and PPA was achieved with the binding energy of −7.8 and −7.2 kcal/mol at the active site and inactive site of PPA, respectively. The performed study reveals that CHA has the potential to inhibit the activity of α-amylase, thereby representing a novel idea to delay the digestion of starch.
研究领域:
生物化学
·
药理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Chengzhi Xu,Lei Yang,Jieliang Su,Jianping Zhang,Jiakai Cao,Xiaodong Li,Gang He,Zhanggui Hu
Silicon nitride (Si 3 N 4 ) with α -phase content ∼90.0 wt% and oxygen content ∼1.00 wt% was prepared by combustion synthesis method using recycled silicon waste from photovoltaic industry. The effects of reaction pressure and environmentally-friendly new additive C 3 H 6 N 6 on the phase composition, and morphology and reaction mechanism of the combustion synthesized α -Si 3 N 4 powder were studied. The results indicate that a lower N 2 pressure is conducive to increasing the α -phase content and reducing the oxygen content of the Si 3 N 4 powder. The addition of C 3 H 6 N 6 as an effective additive facilitates the deoxidation and nitridation reactions of recycled silicon waste, which further increases the α -phase content and reduces the oxygen content of the Si 3 N 4 powder. This work demonstrated that the recycled silicon waste from photovoltaic industry holds great promise to be used as the silicon source for the cost-effective synthesis of high quality α -Si 3 N 4 powder.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Yihui Li,Hang Hu,Qing Zhou,Yanxiao Ao,Chen Xiao,Jiangling Wan,Ying Wan,Huibi Xu,Zifu Li,Xiangliang Yang
Paclitaxel (PTX) is an effective antineoplastic agent and shows potent antitumor activity against a wide spectrum of cancers. Yet, the wide clinical use of PTX is limited by its poor aqueous solubility and the side effects associated with its current therapeutic formulation. To tackle these obstacles, we report, for the first time, α-amylase- and redox-responsive nanoparticles based on hydroxyethyl starch (HES) for the tumor-targeted delivery of PTX. PTX is conjugated onto HES by a redox-sensitive disulfide bond to form HES–SS-PTX, which was confirmed by results from NMR, high-performance liquid chromatography-mass spectrometry, and Fourier transform infrared spectrometry. The HES–SS-PTX conjugates assemble into stable and monodispersed nanoparticles (NPs), as characterized with Dynamic light scattering, transmission electron microscopy, and atomic force microscopy. In blood, α-amylase will degrade the HES shell and thus decrease the size of the HES–SS-PTX NPs, facilitating NP extravasation and penetration into the tumor. A pharmacokinetic study demonstrated that the HES–SS-PTX NPs have a longer half-life than that of the commercial PTX formulation (Taxol). As a consequence, HES–SS-PTX NPs accumulate more in the tumor compared with the extent of Taxol, as shown in an in vivo imaging study. Under reductive conditions, the HES–SS-PTX NPs could disassemble quickly as evidenced by their triggered collapse, burst drug release, and enhanced cytotoxicity against 4T1 tumor cells in the presence of a reducing agent. Collectively, the HES–SS-PTX NPs show improved in vivo antitumor efficacy (63.6 vs 52.4%) and reduced toxicity in 4T1 tumor-bearing mice compared with those of Taxol. These results highlight the advantages of HES-based α-amylase- and redox-responsive NPs, showing their great clinical translation potential for cancer chemotherapy.
研究领域:
药学
·
肿瘤学
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
·
2020
·Vol. 56
·期 5
·2098-2108
·
IF 2.773
Chunli Wang,Qiqi Ma,Zihan Xue,Ruilin Li,Qirou Wang,Nannan Li,Min Zhang,Pharkphoom Panichayupakaranant,Haixia Chen
Summary The investigation aimed at determining the impact of sequential simulated digestion on the physicochemical properties and digestive enzymes inhibitory effects of the polysaccharides fraction (MLP-2) of Morus alba L. leaves as well as its in vitro fermentation behaviours. After artificial salivary, gastric and intestinal digestions, the chemical components and microstructure of MLP-2 were altered with significantly ( P < 0.05) decreased molecular weight. The α-amylase and α-glucosidase inhibitory activities of MLP-2 were significantly ( P < 0.05) improved throughout simulated digestion. MLP-2I, the intestinal digested fraction of MLP-2, could significantly ( P < 0.05) decrease the pH value of fermented culture and increase the short-chain fatty acids (SCFA) concentrations, especially acetic, propionic and butyric acids. In conclusion, MLP-2 could be gradually degraded under simulated digestion with altered physicochemical properties and enhanced α-amylase and α-glucosidase inhibitory effects, and further utilised by human gut microbiota to decrease pH value and promote SCFA production.
研究领域:
食品科学
·
营养学
·
微生物学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yajuan Qin,Xiaoai Chen,Fei Xu,Kexue Zhu,Ping Wang,Yutong Zhang,Yanjun Zhang
The human dietary system, which contains a variety of compounds such as polyphenols and polysaccharides, is very complex. Whether polysaccharides affect the inhibitory of polyphenol mixtures on α-amylase needs to be further investigated. The aim of this study was to analyze the effect and mechanism of pectin on the inhibition of α-amylase by a mixture of rutin and quercetin (R–Q). Results revealed that the inhibition and quenching affinity of R–Q for α-amylase was enhanced by pectin. The Stern-Volmer quenching constant of R–Q–α-amylase was increased by pectin from (6.08 ± 0.453) × 10 3 mL/mg to (9.80 ± 0.285) × 10 3 mL/mg. Pectin enhanced the ability of R–Q to inhibit α-amylase for two main reasons. On the one hand, it was owing to the binding of pectin to rutin, which increased the opportunity for quercetin to bind to the active center of α-amylase, thus enhancing the inhibitory effect of R–Q on α-amylase. On the other hand, pectin and quercetin simultaneously bound to different sites of α-amylase by noncovalent interactions to form the ternary complex of pectin–α-amylase–quercetin. The conformation of α-amylase and the hydrophobicity of amino acid residues were altered by the ternary complex, thereby enhancing the hydrogen bonding in the reaction system.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2025
·
IF 7.5
Junjie Liu,Jianmin Wu,Qiwen Sun,Jiancheng Wang,Yan Sun,Hengxuan Zhang
The high-viscosity poly-alpha-olefin was prepared from Fischer-Tropsch mixed α-olefins (FTO) polymerization under [EBIZrCl 2 /Al( i Bu) 3 /[Ph 3 C] + [B(C 6 F 5 ) 4 ] - system (EBI = rac -C 2 H 4 (1-Ind) 2 ), and its mechanism was investigated by in situ UV–Vis, 1 H NMR and ESI-MS. The results show that the kinematic viscosity at 100°C (KV 100 ), viscosity index (VI) and yield of product reach to 306.3 cSt, 244 and 81.12 % under optimum reaction condition, respectively. Through adjusting temperature to 20°C, in situ UV–Vis, 1 H NMR and ESI-MS are conducted to monitor the formation of origin species (EBIZr( i Bu) 2 + ), active species (EBIZr-σ-y n + (y = nonenyl, decenyl and undecenyl, n ≥ 1)), reactivated species and dormant species (EBIZr-η 3 -(1-R-C m H m+1 ) + (R = n-propyl and m = 6 or 7 or 8)). The simultaneous generation of active and dormant species is observed, and the reaction process is described as [FTO] + [catalyst] → [active species] + [dormant species]. This reaction fitting curve also conforms to the Boltzmann (R 2 ≥ 0.993). The effect of different types of olefins on catalytic evolution and product properties is investigated. The existence of multiple α-olefins inhibits the formation of the second inactivate species found in 1-decene polymerization. However, the multiple isomeric olefins further enhance the possibility of dormant species generation, because of the promotion of β-H concentration in catalytic system, leading to the higher activation energy (19.597kJ/mol) than pure 1-decene (10.949kJ/mol). Based on those findings, a possible mechanism in ansa-zirconocene catalyzed to prepare high-viscosity poly-alpha-olefin from Fischer-Tropsch mixed α-olefins is proposed.
研究领域:
高分子化学
·
催化化学
·
石油化学
·
材料科学
·
工业化学
·
反应机理
·
流变性能
✓ 已验证
产品关联
DOI
高影响因子
SYNTHETIC COMMUNICATIONS
·
2019
·
IF 1.439
Bingbing Han,Zubiao Zheng,Dongcheng Zheng,Lei Zhang,Peng Cui,Jianjun Shi,Changjiang Li
The applications of a new supported tribromide reagent based on poly(vinylbenzyltrimethylammonium hydroxide) resin (Amberlite 717) were reported. This supported tribromide resin was used directly in α-bromination and α-bromoacetalization of acetophenones without any other catalyst under mild conditions. The effects of solvents and the amount of the supported tribromide resin on the reactions were investigated. Under the optimal conditions, most of α-bromo and α-bromoacetal of acetophenones were selectively obtained in excellent yields.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2023
·Vol. 14
·期 1
·76
·
IF 5.3
Ziqi Lv,Kai Ren,Tao Liu,Yunyan Zhao,Zhonghua Zhang,Guicun Li
The rupture of a micro/nano container can trigger the release of repair agents and provides the coating with a self-healing and anti-corrosion effect. However, the defect and inhomogeneity of the coating, produced by the rupture of the micro/nano container, may weaken its anti-corrosion performance. This study reports a rare protection mechanism, which optimizes the space occupying of zirconium phosphate, and the de-doping peculiarity of polyaniline without the rupture of the micro/nano container. Polyaniline/α-zirconium phosphate composites were constructed through in situ oxidation polymerization. Repair agents were added in the form of doped acids. According to the different repair agents in polyaniline/α-zirconium phosphate composites (citric ion, tartaric ion and phytic ion), the performance and protection mechanism of the composites were researched. Polyaniline/α-zirconium phosphate coating (with phytic ion) shows an excellent self-healing anti-corrosive effect, due to the large spatial structure and abundant chelating groups of the precipitation inhibitor. Considering the anti-corrosive application, the developed polyaniline/α-zirconium phosphate composite has a far-reaching influence on marine development.Keywords:polyaniline;α-zirconium phosphate;phytic acid;anti-corrosion;self-healing
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Xi Quan,Jun Zhang,Linlin Yin,Wei Zuo,Yu Tian
In this work, novel Fe 3 O 4 @α-CD nanoparticle was synthesized for the catalytic activation of peroxymonosulfate (PMS) towards carbamazepine (CBZ) degradation. The effect of α-CD content, Fe 3 O 4 @α-CD dosage and PMS concentration on the catalyst activity were systematically evaluated. The results showed the synergistic effect between α-CD and Fe 3 O 4 can greatly improve the removal efficiency of CBZ in the Fe 3 O 4 @α-CD/PMS system. CBZ removal efficiency gained 73.37% in 5 min at pH 7.0 with PMS 1 mM, Fe 3 O 4 @α-CD load 0.4 g/L and CBZ 10 μM. The variation in the removal efficiency of different PPCPs under the same conditions mainly ascribed to the adsorption of α-CD and the activation of PMS by Fe 3 O 4 to generate free radicals, in which sulfate radical (SO 4 ·− ) and hydroxyl radicals ( · OH) was determined as the reactive species in the Fe 3 O 4 @α-CD/PMS system. Density functional theory (DFT) calculations was also utilized to optimize the structure of composite and confirmed that the charge distribution mainly concentrate on Fe 3 O 4 . As deduced from the LC-MS analysis, the possible CBZ degradation pathways were proposed. CBZ degradation efficiency still reached 54% after three cycle, which indicates that Fe 3 O 4 @α-CD catalyst has a good reusability potential and practical applications.
研究领域:
环境科学
·
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）