PROCESS BIOCHEMISTRY
·
2012
·
IF 2.627
Chao-Jun Pei,Jinhyuk Lee,Yue-Xiu Si,Sangho Oh,Wei-An Xu,Shang-Jun Yin,Guo-Ying Qian,Hong-Yan Han
We studied the inhibitory effect of gastrodin on tyrosinase using inhibition kinetics and computational simulation. Gastrodin reversibly inhibited tyrosinase in a mixed-type manner with K i = 123.8 ± 20.2 mM. Time-interval kinetics revealed the inhibition to be a first-order process with mono- and bi-phasic components. Using AutoDock Vina, we calculated a binding energy of −6.3 kcal/mol for gastrodin and tyrosinase, and we performed a molecular dynamics simulation of the tyrosinase–gastrodin interaction. The simulation results suggested that gastrodin interacts primarily with histidine residues in the active site. A 10-ns molecular dynamics simulation showed that one copper ion in the tyrosinase active site was responsible for the interaction with gastrodin. Our study provides insight into the inhibition of tyrosinase by the hydroxyl groups of gastrodin. A combination of inhibition kinetics and computational calculations may help to confirm the inhibitory action of gastrodin on tyrosinase and define the mechanisms of inhibition.
研究领域:
生物化学
·
药物化学
·
计算生物学
✓ 已验证
DOI
高影响因子
LANGMUIR
·
2021
·
IF 3.882
Liang Pan,Guoxi Li,Zhaoyang Wang,Dongbao Liu,Weikang Zhu,Chunyi Tong,Rilong Zhu,Shilin Hu
To reduce the corrosion of Q235 steel, environment-friendly and efficient N-doped carbon dots (N-CDs) were synthesized using 4-amino salicylic acid (4-ASA) and l-histidine (l-His) as precursors. The corrosion inhibition behavior of N-CDs for Q235 steel in 1 M HCl solution was systematically investigated using a weight-loss experiment, an electrochemical test, and corrosion morphology. Results showed that N-CDs could effectively inhibit the corrosion of Q235 steel, and the inhibitory efficiency reached 93% at 50 mg L–1. Quantum chemistry and molecular dynamics were used to study the inhibition mechanism of N-CDs. The results demonstrated that N-CDs exhibited a strong adsorption force on metal and the adsorption process followed the Langmuir adsorption isotherm, indicating physical/chemical mixed adsorption.
研究领域:
材料科学
·
环境科学
·
电化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Xuechuan Wang,Yun Liu,Xinhua Liu,Xiangyu You,Hui Jie Zhang
Developing a paper sizing agent to meet the requirements of low cost, high quality of the paper, and environmental sustainability is significant but remains a challenge. Herein, a novel degradable gelatin-based coating emulsion for paper surface sizing was developed by a simple one-step polymerization and blending process. Poly(methacrylic acid) (PMAA) was first introduced to a gelatin solution to form gelatin-PMAA emulsion (G-PMAA) through the formation of hydrogen bonds between PMAA and gelatin. The addition of PMAA endowed gelatin with the increased hydrophobicity and the decreased upper critical solution temperature. Then, a relatively small amount of the flexible poly(butyl acrylate) (PBA), which imparted the toughness of the formed film, was blended with the G-PMAA emulsion to form G-PMAA/PBA emulsion. The G-PMAA/PBA emulsion with a high gelatin content of 0.2 g/mL was in the sol state at room temperature, which facilitated the application of the G-PMAA/PBA emulsion. The corrugated papers sized by G-PMAA/PBA emulsion exhibited excellent mechanical properties and water resistance.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
COMPOSITES COMMUNICATIONS
·
2020
·
IF 4.915
Ronghua Yu,Jie Liu,Doudou Gao,Yanhui Wang,Xin Wen,Tao Tang
To improve the flame retardancy of polymer nanocomposites , a grafting strategy to modify carbon black nanoparticles by grafting sodium sulfonate (CB- g -SS) was developed in polycarbonate (PC) system. The grafting reaction for CB- g -SS was evaluated by FTIR, XPS and TGA , respectively. Furthermore, PC/CB- g -SS nanocomposites were prepared, and the striking effect of CB and SS on improving the flame retardancy of PC was investigated. With only 1 wt% of CB- g -SS, the PC nanocomposites exhibited a high limiting oxygen index of 33.1%, and V-0 rating in UL-94 test, as well as significant decrease on the peak of heat release rate (PHRR) by 51.6% in cone calorimeter test. The flame retardancy mechanism was also discussed, which was ascribed to the catalytic carbonization of SS on CB surfaces for promoting the formation of interconnected carbon layer. Thus, this work provides a useful and effective method for preparing high-performance PC nanocomposites.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Xiao Xiao,Long Li,Zhuang Wang,Qiao Yu,Xuanhao Huang,Xingyue Liu,Qingjiang Pan,Songdong Ding
Five amine-diamide ligands (DAMIA) with varying alkyl chain lengths and steric hindrances are developed for selective extraction of Am3+ over Eu3+ in high-acidity HNO3 solution with the aim of understanding the structure–activity relationship. The ability of these ligands to extract metal ions is closely related to their basicity. The weaker the basicity is, the stronger the extraction ability is. The substituent on the aminic N has more significant effect on the extraction ability than that on the amidic N. Among the five ligands, the DAMIA containing five branched 2-ethylhexyl substituents demonstrates the highest extraction ability and selectivity at molar acidity level. Slope analysis suggests the formation of a 1:1 metal/ligand extracted species, which is also supported by the results obtained from the UV–vis spectrophotometric titration. Furthermore, the analyses of Fourier transform infrared (FT-IR), time-resolved laser-induced fluorescence spectroscopy (TRLFS), and X-ray photoelectron spectroscopy (XPS) for the extracted complex indicate that one Eu3+ ion may be nine-coordinated by one ligand molecule in a tridentate manner via two amide O atoms and one tertiary amine N atom and three bidentate NO3– ions. There is no H2O molecule in the inner coordination sphere of central Eu3+. Additionally, based on the studies of solvent extraction and complexation, the extraction of metal ions follows the neutral complexation extraction model, and the corresponding thermodynamic parameters (ΔH, ΔS, and ΔG) are also presented.
研究领域:
化学
·
核化学与放射化学
✓ 已验证
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2021
·
IF 6.158
Yimin Liu,Jie Ma,Lili Lian,Xiyue Wang,Hao Zhang,Wenxiu Gao,Dawei Lou
An inorganic-biopolymers hybrid flocculant (PSAC-SA) was prepared by modifying sodium alginate onto polysilicate aluminum calcium (PSAC) through coordination between SA and Ca 2+ . The preparation conditions of PSAC-SA and the flocculation parameters that influence of the turbidity and color removal efficiency were investigated and optimized. The flocculation experiments results showed that the maximum turbidity and color removal could get 97.2% and 98.4% for kaolin-humic acid suspensions, respectively. The application of PSAC-SA for Songhua River treatment indicated that it had an excellent flocculation capacity in real water samples, and its flocculation efficiency was much better than that of individual flocculants (PSAC and SA). Moreover, the flocculation mechanisms were discussed in detailed, which indicated that the bridging effect and physical entrapment of solid particles played an important role in the flocculation process.
研究领域:
环境科学
·
水处理工程
✓ 已验证
DOI
高影响因子
CHEMOSPHERE
·
2018
·
IF 4.427
Ting Tang,Guining Lu,Wenjing Wang,Rui Wang,Kaibo Huang,Zhiyuan Qiu,Xueqin Tao,Zhi Dang
In this study, the TiO 2 -mediated photocatalytic removal of organic phosphate esters (OPEs) under UV irradiation was investigated. In addition, the effects of selected inorganic ions and humic acid (HA) were examined. TCEP, TCPP, and TDCPP hardly undergo degradation via photolysis, and TiO 2 -mediated photocatalysis was confirmed to be effective for removing OPEs present in a water matrix. Inorganic ions (e.g., PO 4 3− , SO 4 2− , Cl − , and NO 3 − ) and HA inhibited the degradation of OPEs. Among these selected ions, PO 4 3− exhibited the strongest inhibition ability, followed by SO 4 2− and then Cl − and NO 3 − , and the inhibition effect increased with the ion concentration . The inhibition effect was caused by two main reasons: (1) Inorganic ions or HA served as ·OH scavengers and competed with OPEs for ·OH. (2) On account of the adsorption of inorganic ions and HA on TiO 2 , the available surface-active sites for OPEs decreased, followed by their oxidation with surface-bound ·OH. The ·OH concentrations were measured by electron spin resonance and the probe method, and it was positively correlated to the degradation rate of OPEs. This study emphasized the importance of inorganic species and HA on the photocatalytic degradation of OPEs and clarified the inhibition mechanism for the degradation of OPEs by the inorganic species or HA.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Shuwang Zhang,Luping Zhang,Jialing Zhao,Wenying Yuan,Xing Fang,Qianqian Yu,Jing Cheng,Xinhong Qiu
ABSTRACT In this study, the degradation of bisphenol A (BPA) was enhanced by adding the reducing agent hydroxylamine hydrochloride (HAHC) into the layered double hydroxides (LDH)/peroxymono- sulfate (PMS) system to promote the conversion of ferric iron (Fe(III)) to Fe(II). The results showed that the degradation efficiency exceeded 90% within 120 min after the addition of HAHC. The effects of initial BPA, PMS concentration, and LDH dosage on BPA degradation efficiency were also evaluated in the HAHC/LDH/PMS system. In addition, the catalyst showed high catalytic activity over a wide pH range (2~10) within the experiment. Radical scavenging tests confirmed that the main reactive oxygen species were sulfate radical (SO 4 •– ), hydroxyl radical ( • OH) and superoxide radical (O 2 •– ) in the HAHC/LDH/PMS process. The reaction mechanism was also inferred by using various analytical techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, electron paramagnetic resonance, scanning electron microscopy, transmission electron microscopy, liquid chromatography–mass spectrometry. This work provides a new strategy for the degradation of organic pollutants by the addition of HAHC to promote the activation of PMS by catalysts.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
JOM
·
2023
·Vol. 75
·期 3
·859-871
·
IF 2.6
Xiong Sang,Liang Dong
Tungsten trioxide (WO 3 ) nanoparticles were prepared by the citric acid method, using ammonium paratungstate as the tungsten source, and doped with rare earth europium (Eu) under various pH values and Eu content. The microstructure, morphology, and luminescence properties of the prepared samples were characterized by XRD, SEM, and a fluorescence spectrometer. The results show that Eu 3+ doped WO 3 nanoparticles were successfully obtained by the citric acid method, the prepared nanoparticles were spherical and rhomboidal, and the average particle size of the prepared samples reached 56 nm. The excitation spectrum consisted of a series of linear excitation peaks in the range of 250–550 nm. The strongest excitation peak was located at 543 nm, which belongs to the 7 F 0 → 5 D 1 transition of Eu 3+ .
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xin-yue Chen,Run-tian Ma,Wei Ha,Yan-ping Shi
We report a colorimetric assay based on oriented Janus gold nanoparticles (AuNPs) aggregation for highly selective and sensitive detection of aspartic acid (Asp) in rat brain. Initially, the Janus AuNPs with relatively large size was prepared, during which the stabilizing agent polyethylene glycol (PEG) and highly selective recognition agent cysteine (Cys) were attached to the selected area at the surface. The addition of Asp causes the oriented and controllable aggregation due to the specific recognition between Cys and Asp. Such a way of aggregation leads to significantly improved long-term stability and an at least 2 orders of magnitude wider dynamic range (1.8 nM–180 μM) compared with conventional colorimetric sensors. In addition, the strategy to increase the size of AuNPs (13–45 nm) enables to efficiently increase the limit of detection (18 μM–1.8 nM). Surprisingly, such a sensor can be applied to direct sensing of cerebral Asp in rat brain, which is determined round 33.9 ± 1.3 μM with satisfactory spiked recovery (86.5 ± 7.5%) due to the excellent anti-interference ability. This work provides a direct and reliable method to evaluate the Asp involved physiological and pathological process and opens a new avenue for real sample detection.
研究领域:
生物化学
·
分析化学
·
神经科学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2016
·
IF 5.554
Fang-Yi Qiu,Mei Zhang,Fu-Sheng Du,Zi-Chen Li
Functional polyesters and poly(carbonate)s (PCs) with controlled and on-demand degradation properties have great advantages for biomedical and pharmaceutical applications. Herein, we report a new kind of aliphatic PC that possesses the feature of oxidation promoted degradation. Two six-membered cyclic carbonates (C1 and C2) containing phenylboronic ester group have been synthesized from serinol (1) and 2-aminomethyl-2-methylpropane-1,3-diol (2), respectively. Both monomers could undergo well-controlled ring-opening polymerization (ROP) catalyzed by an organic base, but the 5,5-disubstituted C2 has the character of equilibrium ROP and a much slower rate than the monosubstituted C1. The copolymerization of C1 or C2 with trimethylene carbonate and its derivative leads to a series of copolymers. Two series of amphiphilic block copolymers (BPC1s and BPC2s) have been prepared from C1 and C2 using poly(ethylene glycol) as the macroinitiator. They are able to form nanoparticles with the diameters less than 150 nm. The H2O2-triggered decomposition of C1, C2, and their corresponding noncyclic model compounds was studied by 1H NMR, showing the consecutive process of oxidation, 1,6-elimination, release of CO2, and intramolecular isomerization or cyclization. The degradation of the block copolymer nanoparticles, investigated by 1H NMR, GPC, laser light scattering (LLS), and Nile Red fluorescence, can also be accelerated drastically by H2O2 following the similar mechanism but is affected by steric hindrance of the polymer chain and heterogeneous microenvironment inside the nanoparticles. The results of 1H NMR and LLS reveal that the nanoparticles of BPC1 and BPC2 exhibited different degradation profiles, with a slightly faster degradation rate for BPC2. Of particular interest, BPC2 nanoparticle is sensitive to as low as 0.02 mM H2O2.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 139
·期 21
·52224
·
IF 3.057
Chuangchuang Sun,Wei Zhang,Yihua Cui,Dongyue Liu
A phosphazene-triazine bi-base sulfonate compound (CPNS) was synthesized using hexachlorocyclotriphosphazene, cyanuric chloride, and sodium p-hydroxybenzene sulfonate as raw materials. The chemical structure was determined by FTIR, 1 H NMR 31 P NMR (NMR stands for nuclear magnetic resonance), and elemental analysis of P, Na. To study the flame retardant properties of CPNS, a series of modified polycarbonate (MPC) with different ratios of CPNS were prepared. The flame retardant performance and thermal stability of CPNS/MPC were characterized by limiting oxygen index (LOI), UL-94 vertical burning test, cone calorimetry test, and TG. Results show that when CPNS is added to 0.3%, the CPNS/MPC can pass the UL94 V-0 level with an LOI value of 35.3% and reduce the peak heat release rate by 16.89% during the combustion. TG results show that adding 0.1% CPNS can decrease the initial decomposition temperature of the MPC by 68°C in nitrogen and 27°C in air. The reduction of the initial decomposition temperature means that the flame retardant promotes the isomerization reaction of polycarbonate accelerates the formation of an intermediate char on the surface. Investigation of intermediate char residue's morphology and chemical structure demonstrates that CPNS promotes the formation of more complete and compact char residue, which acts not only there is increased opportunity for radical recombination reactions in the condensed phase but also as physical barriers to inhibit the transfer of heat and oxygen, resulting in good flame retardant properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）