CHEMICAL PAPERS
·
2018
·Vol. 72
·期 6
·1339-1345
·
IF 0.963
Li Bin,Chen Dan,Zhang Xiaoli,Dong Wenbo,Zhao Binxia
A catalyst comprised of 4-dimethylaminopyridine (DMAP) functionalized silica gel (SG-DMAP) was prepared via a convenient N-alkylation of 4-methylaminopyridine (MAP) with γ-chloropropylated silica gel promoted by potassium iodide. FT-IR, TG, SEM results illustrated that the DMAP was successfully immobilized on silica gel and the BET result suggested the pore structure was not altered after immobilization process. The highest immobilization amount of 0.75 mmol/g was obtained at 130 °C for 12 h. Activity test demonstrated that silica gel immobilized DMAP could be serve as a heterogeneous catalyst for the acylation with significant activity and stability.
✓ 已验证
产品关联
DOI
高影响因子
CHIRALITY
·
2018
·Vol. 30
·期 11
·1225-1232
·
IF 1.833
Yinjun Zhang,Feifei Cheng,Hongde Yan,Jianyong Zheng,Zhao Wang
The kinetic resolution of (R,S)-1-(4-chlorophenyl)ethylamine was accomplished using a commercial lipase from Candida antarctica (Novozym 435). The performance of this lipase was investigated for the enantioselective amidation of (R,S)-1-(4-chlorophenyl)ethylamine, leaving the target product (S)-1-(4-chlorophenyl)ethylamine in its unreacted form. The effects of various types of solvents and an acyl donor, the molar ratio of the substrate to the acyl donor, and the reaction temperature were studied. The optimum reaction conditions were found to result in amidation with methyl 2-tetrahydrofuroate at 40°C in methyl tert-butyl ether, with a substrate/acyl donor molar ratio of 1:2.4. The conversion rate of (R,S)-1-(4-chlorophenyl)ethylamine was 52%, with an enantiomeric excess of 99% towards the unreacted substrate in a reaction time of 22 hours. Finally, using optically pure (S)-1-(4-chlorophenyl)ethylamine as the raw material, the chemical synthesis of (S)-N-(1-(4-chlorphenyl)ethyl)-2-(5,7-dimethyl-[1,2,4]triazolo[1,5-a]pyrimidin-2-ylthio)acetamide, a novel triazolopyrimidine herbicide, was achieved, and the total yield and purity were 83.5% and 95.3%, respectively.
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2019
·
IF 7.65
Yuanshuai Li,Yuting Wang,Liyan He,Lezu Meng,Haijun Lu,Xiaoli Li
In this work, a novel poly(4-vinylpyridine)-functionalized magnetic Al-MOF (Al-MOF-Fe 3 O 4 @P4VP) was synthesized successfully as an adsorbent for the adsorption of naproxen from aqueous solution. The resulting adsorbent was characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometer (VSM), BET surface area and X-ray photoelectron spectroscopy (XPS). Al-MOF-Fe 3 O 4 @P4VP had high surface area (123.68 m 2 /g), porous structure, rough surface and magnetic property. The maximum adsorption capacity of Al-MOF-Fe 3 O 4 @P4VP for naproxen could reach up to 31.67 mg/g and the adsorption process was well described by the Freundlich isotherm. The adsorption rate of naproxen on Al-MOF-Fe 3 O 4 @P4VP was very fast and the kinetics could be well modeled by the pseudo-second-order model. The adsorbent exhibited good adsorption ability even after ten adsorption-desorption cycles. Al-MOF-Fe 3 O 4 @P4VP had the characteristics of high removal efficiency, fast adsorption speed, good reusability and easy separation, making it a novel environment-friendly and effective magnetic nanomaterial in adsorbing naproxen from wastewater.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NANO
·
2017
·
IF 1.025
Jingyuan Cao,Fei Wang,Shuai Liang,Xue Tong,Zhongnan Zhang,Jian Feng,Haifeng Wang,Xingmao Jiang
Nickel nanoparticles embedded in mesoporous silica (Ni/SiO 2 ) were successfully synthesized by microwave-assisted in situ self-assembly method using colloidal silica, urea and nickel nitrate as precursors and glucose as carbon template, which resulted in mesoporous structure of silica through removal of template. Ni nanoparticles were uniformly well-dispersed within mesoporous silica, which were 3.5–4.0 nm in diameter and had a very narrow particle size distribution. In addition, particle size of Ni nanoparticles can be controllably adjusted by microwave power. As-prepared Ni/SiO 2 catalyst exhibited better catalytic activity for reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) than Ni/SiO 2 -IM catalyst, which was mainly attributed to confinement effect of mesoporous silica support. This simple and versatile method can also be extended to cover many kinds of other supported catalysts for broad applications in many other catalytic reactions in the future.
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Shuang Guo,Shuo Liu,Chang Liu,Yi Wang,Dongyu Gu,Jing Tian,Yi Yang
Immobilization technology plays an important role in enhancing enzyme stability and environmental adaptability. Despite its rapid development, this technology still encounters many challenges such as enzyme leakage, difficulties in large-scale implementation, and limited reusability. Drawing inspiration from natural paired molecules, this study aimed to establish a method for immobilized α-glucosidase using artificial antibody-antigen interaction. The proposed method consists of three main parts: synthesis of artificial antibodies, synthesis of artificial antigens, and assembly of the artificial antibody-antigen complex. The critical step in this method involves selecting a pair of structurally similar compounds: catechol as a template for preparing artificial antibodies and protocatechualdehyde for modifying the enzyme to create the artificial antigens. By utilizing the same functional groups in these compounds, specific recognition of the antigen by the artificial antibody can be achieved, thereby immobilizing the enzymes. The results demonstrated that the immobilization amount, specific activity, and enzyme activity of the immobilized α-glucosidase were 25.09 ± 0.10 mg/g, 5.71 ± 0.17 U/mg protein and 143.25 ± 1.71 U/g carrier , respectively. The immobilized α-glucosidase not only exhibited excellent reusability but also demonstrated remarkable performance in catalyzing the hydrolysis of 4-methylumbelliferyl-α-D-glucopyranoside.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHOTOCHEMISTRY AND PHOTOBIOLOGY
·
2012
·Vol. 88
·期 4
·860-866
·
IF 2.413
Cheng-Hui Zeng,Yang-Yi Yang,Yi-Min Zhu,Hong-Ming Wang,Tian-Shu Chu,Seik Weng Ng
A new dinuclear terbium complex [Tb 2 (4-msal) 6 (H 2 O) 4 ]·6H 2 O ( 1 ) (4-msal = 4-methylsalcylate) was synthesized. Its structure was determined by single crystal X-ray diffraction, and the complex was characterized by PXRD, FT-IR, fluorescence, TGA and DTA. Complex 1 exists as discrete molecules that are linked by extensive O–H … O hydrogen bonds into a 3D network. The luminescence lifetimes of 3 μ m methanol solution and solid sample of 1 are 1.321 and 1.009 ms, respectively. The quantum yield of solid sample is 6.0%. The luminescence quenched more than 50% when 3% (vol/vol) different impurities (acetone, acetonitrile, chloroform, dichloromethane, dioxane, DMF, DMSO, ethanol, ether, ethyl acetate, glycol, H 2 O, hexane, TEA, THF and toluene or their mixture) were added. The inverse linear relationship between the L g value of fluorescence intensity and the volume ratio of the minor component (to a maximum of 20%) is interpreted in terms of L g I = a − bX ( I : luminescence intensity; X : volume ratio of impurities in methanol; a , b are constants). So 1 is a potential luminescent sensor for analyzing the purity of methanol.
✓ 已验证
DOI
PubMed
高影响因子
ATMOSPHERIC ENVIRONMENT
·
2024
·
IF 4.2
Ruoyuan Lei,Yingying Sha,Haifeng Meng,Yu Huang,Jianhuai Ye,Dan Dan Huang,Yunjiang Zhang,Yun Wu,Yongjie Li,Xinlei Ge
4-nitrocatechol (4NC) is a model compound of nitrophenols, an important group pf light-absorbing species, a.k.a., brown carbon (BrC), that have significant impacts on air quality and radiation forcing. This work aims to elucidate the kinetics, chemical and optical properties as well as oxidation potential (OP) of 4NC during aqueous photolysis. Results show that hydroxyl radical (∙OH) initiated photo-oxidation has the fastest reaction rate (6.1 ×10 -5 s -1 ) followed by organic triplet state ( 3 C*) induced photolysis (3.8 ×10 -5 s -1 ) and direct photolysis (2.4 ×10 -5 s -1 ); the second-order rate constant of ∙OH with 4NC is determined to be 4.3 × 10 10 M -1 s -1 . Reaction pathways of 3 C*-initiated photolysis and ∙OH-initiated photolysis are largely different, with the former generating more oxygenated species, but their mass yields of products after 12 hours of irradiation are close (∼40 %). Aqueous ageing of 4NC overall leads to the decrease of light absorption, and the photo-bleaching rates are in an order of ∙OH (2.58 × 10 -5 s -1 ) > 3 C* (1.06 × 10 -5 s -1 ) > direct photolysis (5.83 × 10 -6 s -1 ) too; the second-order photo-bleaching rate constant of ∙OH with 4NC is 1.77 × 10 10 M -1 s -1 . On the other hand, aqueous ageing can also produce BrC species (not sufficient to offset the photo-bleaching effect) of which some nitrogen-containing organics are an important part, and 3 C*-photolysis has the strongest production ability. Furthermore, aqueous photolysis of 4NC can decrease its OP, especially the ∙OH-photolysis products are nearly non-toxic while those from 3 C*-photolysis still has significantly high OP at the end of oxidation. Finally, we estimated the atmospheric lifetimes of 4NC against ∙OH in different atmospheric environments, which range from a few seconds to tens of hours.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 5
·期 3
·595-603
·
IF 4.872
Yan Xiao,Sihuan Lang,Miaomiao Zhou,Jing Qin,Rui Yin,Jingming Gao,Andreas Heise,Meidong Lang
A series of biodegradable and crosslinkable precursors based on poly(4-methyl-ε-caprolactone) (PMCL) were prepared by ring-opening polymerization (ROP), followed by the complete acrylation of both hydroxyl ends. Afterwards, biodegradable networks exhibiting totally amorphous character were obtained via photocrosslinking without organic solvent or high temperature. As a result, their mechanical properties varied significantly from brittle to elastic upon increasing the length of the PMCL precursors. Both covalent crosslinking and trapped entanglements between crosslinking segments were likely to contribute to the unique properties of the bioelastomer. In particular, networks formed by the precursors with large molecular weights presented high flexibility and resilience, which match the mechanical properties of soft tissues like blood vessels, bladder and cardiovascular tissue. Preliminary degradation and in vitro cytotoxicity studies of the crosslinked network showed excellent biodegradability and biocompatibility. Moreover, it was demonstrated that the liquid-like PMCL precursor made the patterning easily processable even in the absence of any solvent or heating.
✓ 已验证
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 25
·4744-4748
·
IF 3.849
Wangen Zhao,Daocheng Pan,Shengzhong (Frank) Liu
Achieving micro-sized and closely packed grains is an essential requirement for high-performance chalcogenide thin film solar cells. Here, I2–II–IV–VI4 (Cu2MnSn(S,Se)4) (CMTSSe) thin films were successfully deposited by carrying out a simple, degradable solution-based process. The structure, composition, and morphology were characterized by powder X-ray diffraction (XRD), energy dispersive spectrometry (EDS), and scanning electron microscopy (SEM), and the Hall effect was also measured. These characterizations indicated that CMTSSe thin films may find applications in photovoltaic absorbing materials. In addition, different substrates were found to affect the morphology and compactness of the grains of the thin film.
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Qianghua Ye,Fanyong Yan,Depeng Kong,Jin Zhang,Xuguang Zhou,Jinxia Xu,Li Chen
Carbon dots (CDs) were covalently linked to 4-carboxyphenylboronic acid molecules to form the 4-carboxyphenylboronic acid molecules-functionalized CDs (CPBA-CDs). The CPBA functional groups, which were reactive toward vicinal diols, could covalently bridge the catechol with the vicinal diol structures and would cause the fluorescence quenching via the static quenching mechanism. As the concentration of catechol increased, the fluorescent signal gradually decreased. The fluorescent response for catechol detection was in the linear ranges from 0.1 to 56 μM with the detection limit of 115 nM. We further demonstrated that CPBA-CDs with good biocompatibility were easily and quickly internalized by human umbilical vein endothelial cells and are particularly suitable for multicolour real-time cellular imaging.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2017
·
IF 2.474
Kai Luo,Liming Hu,Qi Guo,Chenghui Wu,Songsong Wu,Daofeng Liu,Yonghua Xiong,Weihua Lai
ABSTRACT Immunochromatographic assays (ICA) are widely used to detect pathogens. In this study, we used traditional gold nanoparticles (GNP), quantum dots (QD), fluorescent nanoparticles (FNP), and europium (Eu) (III) chelate nanoparticles (EuNP) as ICA labels. We first compared the ability of the 4 ICA test strips to quantitatively detect Escherichia coli O157:H7 in milk. We then optimized various parameters influencing the ICA. The sensitivity to E. coli O157:H7 of the GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA was 2.5 × 10 4 , 5 × 10 3 , 1.0 × 10 3 , and 5.0 × 10 2 cfu mL −1 , respectively. The EuNP-ICA exhibited the highest sensitivity. The amounts of monoclonal antibodies (mAb) per GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA test strip were 0.16, 0.37, 0.04, and 0.10 μg, respectively. The corresponding coefficients of variation were 7.4 to 15.8%, 10.4 to 18.6%, 2.7 to 7.8%, and 6.9 to 10.5%, respectively. The FNP-ICA required the least mAb per test strip and had the best coefficient of variation. The linear ranges of GNP-ICA, QD-ICA, FNP-ICA, and EuNP-ICA were 1.0 × 10 4 to 1.0 × 10 6 , 2.5 × 10 3 to 1.0 × 10 6 , 2.5 × 10 2 to 2.5 × 10 5 , and 2.5 × 10 2 to 2.5 × 10 5 cfu mL −1 , respectively. The FNP-ICA and EuNP-ICA had wider linear ranges than GNP-ICA and QD-ICA. Additionally, the FNP-ICA and EuNP-ICA showed better tolerance than GNP-ICA and QD-ICA in the milk samples. The FNP-ICA and EuNP-ICA showed remarkable potential for detection of pathogens in milk.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2016
·
IF 4.569
Ning Xia,Lin Liu,Yong Chang,Yuanqiang Hao,Xiaojin Wang
This work presented a general way for in situ formation of citrate-capped silver nanoparticle (AgNP) aggregates as labels on an electrode surface. When the electrode surface was functionalised with a member of the o -diphenol family, 4-mercaptophenylboronic acid (MPBA) was anchored onto the electrode surface via a boronate ester covalent bond. The anchored MPBA captured AgNPs through Ag S interaction. The resulting surface-tethered AgNPs could recruit more MPBA molecules and AgNPs through the formation of an Ag S bond and the covalent interaction between the α-hydroxycarboxylate of the citrate and the boronate of the MPBA. This led to in situ formation of a network of AgNPs. The complexes formed between MBPA and citrate acid, as well as dopamine (a member of the o -diphenol family), were characterized by mass spectrometry . The MBPA-induced aggregation of citrate-capped AgNPs in solution was confirmed by UV–Vis spectrophotometry and transmission electron microscopy. The network of AgNPs formed on the diphenol-covered electrode surface was characterized by scanning electron microscopy. The electrochemical signal was measured based on the solid-state Ag/AgCl reaction of the AgNPs. To demonstrate the applications and analytical merits of our design, tyrosinase and protease (thrombin) were measured as model analytes. The proposed strategy is likely to lead to the development of sensors for the detection of other biomolecules.
✓ 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）