Journal of Environmental Chemical Engineering
·
2020
·
IF 4.3
Qian Zhang,Shuting Zhuang,Jianlong Wang
Biosorption is a cleaner technology for the treatment of heavy metal-containing wastewater. In this study, a cleaner method was proposed for preparing a novel biosorbent, magnetic cyanoethyl chitosan beads, which was characterized by FT-IR, SEM-EDS, XRD, TGA, BET, and vibrating sample magnetometer, and applied for removing Co 2+ from aqueous solutions. The influencing factors, such as contact time (0−120 min), pH (5–8), and initial concentration of cobalt ions (10−600 mg L −1 ), were examined. The first-order, second-order, intraparticle diffusion, and Elovich models were used to simulate the kinetics of the cobalt adsorption process. The experimental data of isotherms were analyzed by the Langmuir, Freundlich, and Temkin models. Among them, the second-order model and Langmuir model were the best fitting. The adsorption capacity was calculated to be 17.92 mg g −1 according to the Langmuir model. From the analysis of the FT-IR spectra, it can be inferred that CN and NH 2 were mainly responsible for the adsorption of Co 2+ from aqueous solutions. The grafting of cyanoethyl groups on chitosan enhanced the sorption capacity towards Co 2+ , the magnetic cyanoethyl chitosan bead is economical and effective biosorbent for the treatment heavy metal-containing wastewater.
研究领域:
环境科学
·
材料科学
·
生物技术
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Jun Huang,Haihua Xie,Hui Ye,Tian Xie,Yuecheng Lin,Jinyan Gong,Chengjun Jiang,Yuanfeng Wu,Shiwang Liu,Yanli Cui,Jianwei Mao,Lehe Mei
Chitosan was prepared by N -deacetylation of squid pens β-chitin, and N -carboxyethylated chitosan ( N -CECS) with different degrees of substitution (DS) were synthesized. DS values of N -CECS derivatives calculated by 1 H nuclear magnetic resonance (NMR) spectroscopy were 0.60, 1.02 and 1.46, respectively. The adsorption capacity of Cu(II) by N -CECS correlated well with the DS and pH ranging from 3.2 to 5.8. The maximum Cu(II) adsorption capacity ( q m ) of all three N -CECS at pH 5.4 was 207.5 mg g −1 , which was 1.4-fold higher than that of chitosan. The adsorption equilibrium process was better described by the Langmuir than Freundlich isotherm model. Adsorption of Cu(II) ion onto N -CECS followed a pseudo-second order mechanism with chemisorption as the rate-limiting step. In a ternary adsorption system, the adsorption capacity of Cu(II) by N -CECS also presented high values, and q m for Cu(II), Cd(II), and Pb(II) were 150.2, 28.8, and 187.9 mg g −1 , respectively.
研究领域:
生物化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
·
2012
·
IF 2.986
Linping Sun,Xinwen Guo,Guang Xiong,Xiangsheng Wang
The ethylation of coking benzene with ethanol over nano-sized ZSM-5 zeolites modified with Y 2 O 3 , La 2 O 3 and CeO 2 was investigated in a fixed-bed reactor. Nano-sized ZSM-5 zeolite modified with Y 2 O 3 was more stable than the other two samples during the reaction. The results from NH 3 -TPD, Py-IR, and TG-DTA show that the strong Brønsted acid sites were eliminated, consequently suppressing coke deposits during the reaction. Combined with the results from 1 H NMR and 129 Xe NMR spectra, it is concluded that the hydrated Yttrium ions with small size reached deep location in zeolite channel.
研究领域:
化学工程
·
催化科学
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产品关联
DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 21
·11280-11288
·
IF 2.936
Qingna Lin,Lipeng Han,Guoqin Liu,Weiwei Cheng,Liqing Wang
The formation of food-derived glycated phosphatidylethanolamine (PE) in thermal process was investigated by designing a 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE)-glucose model system heated from 40 to 100 °C for 8 h. The main products of glycated PE were determined by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Results showed that the glycation of DPPE formed three major glycated compounds: amadori-glycated-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (Amadori-DPPE), carboxymethyl-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CM-DPPE), and carboxyethyl-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (CE-DPPE). Amadori-DPPE was identified to generate CM-DPPE through oxidative cleavage of glycated polar head group under high temperature and extended incubation time. Additionally, during thermal processing, retro-aldol reactions of glucose led to the formation of two reactive dicarbonyl intermediates: glyoxal (GO) and methylglyoxal (MGO), both of them reacted with amino group of DPPE to form CM-DPPE and CE-DPPE, respectively. Thus, the formation pathways of CM-PE might involve the irreversible rearrangements of Amadori-PE following oxidative cleavage, as well as the glycation of amino group of PE with GO. CE-PE could only be formed by reaction of PE with MGO. Moreover, the content of CM-DPPE was higher than that of CE-DPPE in the same incubation conditions, which indicated that CM-PE might be a more useful predictive marker for food-derived glycated amino-phospholipid, rather than Amadori-PE, particularly in thermal processed foodstuffs.
研究领域:
食品科学
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生物化学
·
营养学
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产品关联
DOI
PubMed
高影响因子
PLoS One
·
2013
·Vol. 8
·期 3
·e59882
·
IF 3.73
Lushan Yu,Yan Jiang,Lu Wang,Rong Sheng,Yongzhou Hu,Su Zeng
BYZX, [(E)-2-(4-((diethylamino)methyl)benzylidene)-5,6-dimethoxy-2,3-dihydroinden-one], belongs to a series of novel acetylcholinesterase inhibitors and has been synthesized as a new chemical entity for the treatment of Alzheimer’s disease symptoms. When incubated with human liver microsomes (HLMs), BYZX was rapidly transformed into its metabolites M1, M2, and M3. The chemical structures of these metabolites were identified using liquid chromatography tandem mass spectrometry and nuclear magnetic resonance, which indicated that M1 was an N -desethylated and C = C hydrogenation metabolite of BYZX. M2 and M3 were 2 precursor metabolites, which resulted from the hydrogenation and desethylation of BYZX, respectively. Further studies with chemical inhibitors and human recombinant cytochrome P450s (CYPs), and correlation studies were performed. The results indicated that the N -desethylation of BYZX and M2 was mediated by CYP3A4 and CYP2C8. The reduced form of β-nicotinamide adenine dinucleotide 2′-phosphate was involved in the hydrogenation of BYZX and M3, and this reaction occurred in the HLMs and in the human liver cytosol. The hydrogenation reaction was not inhibited by any chemical inhibitors of CYPs, but it was significantly inhibited by some substrates of α,β-ketoalkene C = C reductases and their inhibitors such as benzylideneacetone, dicoumarol, and indomethacin. Our results suggest that α,β-ketoalkene C = C reductases may play a role in the hydrogenation reaction, but this issue requires further clarification.
研究领域:
药理学
·
生物化学
·
阿尔茨海默病研究
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2018
·
IF 3.849
Wei Liu,Yanyan Lv,Shuai Tian,Mengwei Zhang,Ting Shu,Nan Hu,Zhaoliang Wu
In this work, foam fractionation has been proposed to recover resveratrol from the leaching liquor of Polygonum cuspidatum . Resveratrol is a natural polyphenol without surface activity. For achieving the adsorption of resveratrol on the gas-liquid interface, a biological surfactant of partially ethylated β-cyclodextrin (partially Eβ-CD) was prepared. First, the inclusion behavior between partially Eβ-CD and resveratrol was investigated. Resveratrol molecular could easily enter into the cavity of partially Eβ-CD from its wide rim due to the possible driving forces of charge transfer and dipole-dipole interactions. The experiments of foam properties suggested that partially Eβ-CD could decrease the surface tension of aqueous solution, thus generating stable foam. By using partially Eβ-CD as collector and frother, foam fractionation was performed. Under the suitable conditions of partially Eβ-CD concentration 0.680 g/L, loading liquid volume 250 mL, volumetric air flow rate 40 mL/min, pore diameter of gas distributor 0.45 mm and pH 4.0, the enrichment ratio and the recovery percentage of resveratrol reached 2.79 and 73.84%, respectively. The concentration of resveratrol in the foamate was as high as 0.050 g/L. This work is expected to provide a new strategy to effectively recover a non-surface-active material from its aqueous solution, and to facilitate the industrialization of foam fractionation.
研究领域:
生物工程
·
天然产物化学
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产品关联
DOI
高影响因子
Catalysts
·
2019
·Vol. 10
·期 1
·6
·
IF 3.444
Jia Huang,Gang Nie,Yaobin Ding
To develop highly efficient heterogeneous photocatalysts for the activation of dissolved oxygen is very interesting in the field of green degradation of organic pollutants. In the paper, oxygen atom doped g-C3N4(O-g-C3N4) was prepared via a facile chemical oxidation of g-C3N4by peroxymonosulfate. X-ray photoelectron spectroscopy analysis suggests the oxidative treatment of g-C3N4by peroxymonosulfate evidently increased atomic percentage of oxygen on O-g-C3N4surface to 6.9% as compared with 1.8% for g-C3N4. Meanwhile, the doped oxygen atom mainly existed as carbonyl and carboxyl groups. Optical characterization indicates the introduction of oxygen improved the response of O-g-C3N4to visible light, and more obviously, separation of photo-generated h+-e−. 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) probe measurement indicates the formation of O2•−was dramatically enhanced through activation of dioxygen by photo-generated electrons in the O-g-C3N4photocatalytic system. Through high performance liquid chromatography (HPLC) and Liquid chromatography–mass spectrometry (LC-MS) analysis, it was found rhodamine B (RhB) photocatalytic degradation by O-g-C3N4followed step by step N-deethylation reaction pathways induced by the formed O2•−, rather than the non-selective decomposition of the chromophore in RhB by other radicals, such as hydroxyl radicals. This study provides a facile method to develop oxygen atom doped g-C3N4photocatalyst, and also clarifies its photocatalytic activation mechanism of molecular oxygen for N-deethylation reaction of RhB.Keywords:photocatalysis;oxygen doped g-C3N4;activation of dioxygen;superoxide radicals;selective N-deethylation of rhodamine B
研究领域:
环境科学
·
材料科学
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Lingyu Kong,Zhe Qiu,Yonggui Wang,Yanjun Xie,Zefang Xiao
The generation of electricity from water, which contains enormous amounts of energy, has attracted significant attention in recent years. However, the development of devices consisting of materials with the required mechanical stability, suitable structures, and wide ion concentration gradients for operation in direct contact with water remains challenging. Herein, we report the preparation of three-dimensional foam structures based on covalent cross-linking and freeze-drying using cellulose and chitosan derivatives as raw materials. Carbon nanotubes (CNTs), which served as the photothermal component, were uniformly dispersed among the cellulose nanofiber (CNF) to realize photothermally enhanced heterogeneous water-enabled electricity generation (HWEG). The output performance of the assembled HWEG was improved by tailoring the ion concentration gradient and widening the moisture gradient induced by photothermal conversion. Under solar irradiation of 1 sun, the HWEG delivered an open-circuit voltage and short-circuit current of 186 mV and 0.5 μA, respectively. Owing to the scalability and practicality of the device, the class of three-dimensional structural materials based on sustainable biomass developed in this study is suitable for use in hydrovoltaic energy harvesters.
研究领域:
材料科学
·
能源工程
·
可持续发展
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产品关联
DOI
PubMed
高影响因子
Current Protocols
·
2023
·Vol. 3
·期 11
·e923
·
IF 0
Xuan Chen,Long Xie,Chenglong Zhang,Shen Tian,Zeyu Tang,Weiwei Tian,Patrick Lu,Xianbin Yang
Although small interfering RNA (siRNA) is a key player among gene inhibition therapeutics, there are many obstacles to the development of siRNA drugs due to inherent properties of oligonucleotides, including the unsatisfactory stability of unmodified siRNA, poor pharmacokinetic distribution, and the toxicity induced by off-target effects. To maximize treatment potency, chemical modification of siRNA has undoubtedly been the most successful strategy by far. Widely applied modifications include phosphorothioate linkages, 2′- O -methyl modifications, and 2′-fluoro modifications, among others. To extend the family of chemical modifications for oligonucleotides, 2′- O -cyanoethylated RNA analogs were developed through the replacement of the 2′-hydroxyl group with a 2′- O -cyanoethyl group (-OCH 2 CH 2 CN). This modification can provide several advantages over unmodified RNA, such as increased stability, improved binding affinity to complementary DNA or RNA strands, and resistance to degradation by cellular nucleases. The 2′- O -cyanoethyl-modified RNAs not only are applied in RNA silencing machinery but also act as research tools for studying RNA structure and function or for developing RNA-based diagnostics. Therefore, the efficient synthesis, deprotection, purification, and characterization of 2′- O -cyanoethylated RNAs deserves more attention. This protocol describes the chemical synthesis of 2′- O -cyanoethylated nucleotides and the solid-phase synthesis, deprotection, and purification of 2′- O -cyanoethylated RNAs. © 2023 Wiley Periodicals LLC. Basic Protocol 1 : Preparation of 6- N -dimethylformamidyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl adenosine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 2 : Preparation of 4- N -acetyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl cytidine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 3 : Preparation of 2- N -dimethylformamidyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl guanine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 4 : Preparation of 5′- O -dimethoxytrityl-2′- O -2-cyanoethyl uridine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 5 : Solid-phase synthesis of 2′- O -cyanoethylated RNA analogs Basic Protocol 6 : Deprotection and purification of synthesized 2′- O -cyanoethyl-RNAs
研究领域:
分子生物学
·
生物化学
·
药物化学
·
RNA治疗学
·
有机合成
✓ 已验证
DOI
ANALYTICA CHIMICA ACTA
·
2016
·
IF 4.712
Henghui Li,Wenjie Gao,Xiaojun Feng,Bi-Feng Liu,Xin Liu
Sialic acids usually locate at the terminal of many glycan structures in either α(2,3) or α(2,6) linkage, playing different roles in various biological and pathological processes. Several linkage specific carboxyl derivatization methods have been reported to discriminate between α(2,3) and α(2,6)-linked sialic acids by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Among them, ethyl esterification was recently reported to achieve linkage specific derivatization between α(2,3) and α(2,6)-linked sialic acids with good selectivity . However, the method suffered from the instability of the generated lactones and byproducts of the derivatives. To overcome these shortcomings, a solid-phase two step derivatization method was introduced to convert the α(2,6)-linked sialic acid into ethyl esters and the α(2,3)-inked counterparts into N-methyl amides, respectively. Under the optimized derivatization conditions, our method was able to achieve accurate relative quantification of N-glycan as well as their corresponding sialylated linkage types, superior to the ethyl esterification method. The solid phase derivatization strategy was further applied to investigate N-glycans from biosimilar antibody drug and human serum from patients and healthy volunteers. This method has the potential to be used in the biomarker discovery and pharmaceutical industry .
研究领域:
分析化学
·
药学
·
生物化学
·
临床化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）