MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 10
·1-9
·
IF 5.479
Yi Haoyang,Yan Zhiyu,Wang Lumei,Zhou Xiaotong,Yan Rui,Zhang Dongwei,Shen Guoqing,Zhou Shanshan
A fluorometric method is described for the determination of ofloxacin (OFL). It is based on the use of the fluorescent intercalator SYBR Green I (SG-I). The OFL-aptamer has G-quadruplex structures and can be recognized by SG-I. It results in strong fluorescence of SG-I. If OFL is present, OFL will bind to its aptamer to form stable complexes. This induces the despiralization of partial dsDNA regions, leads to changes in the structure of the aptamer. Thus, SG-I is released from the OFL-aptamer into solution. Hence, the fluorescence of SG-I drops. Fluorescence decreases linearly in the 1.1 to 200 nM OFL concentration range, and the limit of detection is 0.34 nM. The method shows good selectivity to much interference including analogues, hormones, pesticides. It is also effortless and fast with the times of measurement of <40 min. In addition, good recoveries of 91.3–119.0% were found for tap water, river water and artificial urine spiked with OFL with relative standard deviation (RSD) of ≤11.6%.
A sensitive fluorometric method is developed for ofloxacin (OFL) detection in aqueous samples based on the fluorescence intensity change of SYBR Green I (SG-I) with or without OFL.
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PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
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2020
·
IF 1.415
Cai-Yun Liu,Wen-Bin Su,Li-Bin Guo,Ye-Wang Zhang
Heparinase I (Hep I) specifically degrades heparin to oligosaccharide or unsaturated disaccharide and has been widely used in preparation of low molecular weight heparin (LMWH). In this work, a novel Hep I from Bacteroides eggerthii VPI T5-42B-1 was cloned and overexpressed in Escherichia coli BL21 (DE3). The enzyme has specific activity of 480 IU·mg−1 at the optimal temperature and pH of 30 °C and pH 7.5, and the Km and Vmax were 3.6 mg·mL−1 and 647.93 U·mg−1, respectively. The Hep I has good stability with t1/2 values of 350 and 60 min at 30 and 37 °C, respectively. And it showed a residual relative activity of 70.8% after 21 days incubation at 4 °C. Substrate docking study revealed that Lys99, Arg101, Gln241, Lys270, Asn275, and Lys292 were mainly involved in the substrate binding of Hep I. The shorter hydrogen bonds formed between heparin and these residues suggested the higher specific activity of BeHep I. And the minimum conformational entropy value of 756 J·K−1 provides an evidence for the improved stability of this enzyme. This Hep I could be of interest in the industrial preparation of LMWH for its high specific activity and good stability.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Xingwen Liu,Qi Wang,Zhuo Wang,Xueting Liu,Minghui Zhang,Jiahui Fan,Zhiyong Zhou,Zhongqi Ren
A new type of Rb(I) ion imprinting material was prepared with methacrylic acid as functional monomer, Rb(I) ion as template, and methanol/acetonitrile as solvent. The polymerization reaction was initiated by N,N-azobis(isobutyronitrile) (AIBN) with the cross-linking by ethylene glycol dimethacrylate (EGDMA). In addition, benzo-12-crown-4-ether (B12C4) was introduced as a ligand to fix the template ions better. Scanning electron microscope, Zeta potential analysis, Fourier transform infrared spectrum, thermogravimetric analysis, and energy dispersive spectra were used for characterization of the imprinted polymer. Effects of preparation and adsorption conditions on adsorption performances of Rb(I) ion-imprinted polymers (IIPs) were investigated. The imprinted polymer had fast adsorption kinetics (reaching equilibrium within 15 min) and high maximum adsorption capacity (129.9 mg·g–1) at pH 9.5. Besides, the adsorption process conformed to pseudo-second-order kinetic and Freundlich isotherm models. Moreover, the prepared Rb(I)-IIPs showed high selectivity for Rb(I) ions. The results of eight repeated cycles of adsorption–desorption demonstrated that the prepared Rb(I)-IIPs had good stability and reusability.
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PeerJ
·
2019
·
IF 2.353
Weilong Zhang,Yang Wu,Jin Wang,Juan Liu,Haifeng Lu,Shuijing Zhai,Qiaohui Zhong,Siyu Liu,Wanying Zhong,Chunling Huang,Xiaoxiang Yu,Wenhui Zhang,Yongheng Chen
Rutile nano-titanium dioxide (RNTD) characterized by loose particles with diameter in 20–50 nm has a very large surface area for adsorption of Tl, a typical trace metal that has severe toxicity. The increasing application of RNTD and widespread discharge of Tl-bearing effluents from various industrial activities would increase the risk of their co-exposure in aquatic environments. The adsorption behavior of Tl(I) (a prevalent form of Tl in nature) on RNTD was studied as a function of solution pH, temperature, and ion strength. Adsorption isotherms, kinetics, and thermodynamics for Tl(I) were also investigated. The adsorption of Tl(I) on RNTD started at very low pH values and increased abruptly, then maintained at high level with increasing pH >9. Uptake of Tl(I) was very fast on RNTD in the first 15 min then slowed down. The adsorption of Tl(I) on RNTD was an exothermic process; and the adsorption isotherm of Tl(I) followed the Langmuir model, with the maximum adsorption amount of 51.2 mg/g at room temperature. The kinetics of Tl adsorption can be described by a pseudo-second-order equation. FT-IR spectroscopy revealed that -OH and -TiOO-H play an important role in the adsorption. All these results indicate that RNTD has a fast adsorption rate and excellent adsorption amount for Tl(I), which can thus alter the transport, bioavailability and fate of Tl(I) in aqueous environment.
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POLYMER
·
2019
·
IF 3.771
Yao Liu,Hao Peng,Pingping Wu,Huaizhi Liu,Jiuyang Zhang
Emissive organometallic polymers integrated with the properties of conventional polymers have attracted increasing attention from researchers. Copper (I)-thioether (Cu(I)-thioether) complexes of small molecule has been extensively reported, which is in sharply contrast with much less investigated Cu(I)-thioether polymers. In this work, Cu(I)-thioether coordination structure has been successfully combined with polymer ligands to form emissive polymer networks . The resulted hybrid networks overcame many challenges in the Cu(I)-thioether small compounds. The as-prepared Cu(I)-thioether networks exhibited much improved thermal stability (degradation temperature: 220 °C) compared with Cu(I)-thioether molecular clusters. Besides, the Cu(I)-thioether networks can be processed into uniform free-standing film with excellent stretchability (breaking strain up to 200%) which cannot be realized in the Cu(I)-thioether small molecular system. Finally, the luminescent property of copper-thiother was inherited in the polymer networks and emissive polymer films with good transparency, excellent thermal stability and high stretchability. Interestingly, the dynamic coordination between thioether and copper (I) enabled the self-healing ability of the polymer films. The damaged emissive and stretchable films were able to be autonomous self-healed under ambient conditions. This work sheds lights on the design and fabrication of Cu(I)-thioether materials for advanced applications.
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ANALYST
·
2019
·Vol. 145
·期 3
·873-879
·
IF 4.019
Minghan Wang,Junjie Liu,Xiaoli Qin,Xin Nie,Yifan Dong,Xu Liang,Zhiwei Zhu,Di Yang,Yuanhua Shao
In this work, an Au–Ag alloy nanourchin (Au–Ag alloy NU) based electrochemiluminescent (ECL) sensor for the measurement of cardiac troponin I (cTnI) was developed. The as-prepared Au–Ag alloy NUs exhibited higher specific surface area and better conductivity owing to their unique urchin-like morphology, which resulted in excellent electrocatalytic activity towards H2O2 in the luminol–H2O2 ECL system. We have found that the Au–Ag alloy NUs could enhance the ECL signal in the luminol–H2O2 solution. Based on these facts, a facile and label-free ECL immunosensor has been constructed for the analysis of cTnI, a cardiac biomarker, with a wide linear range of 3.5 pg mL−1–350 μg mL−1. This novel ECL immunosensor has good stability and reproducibility, showing potential application in clinical diagnostics. In addition, a non-enzymatic electrochemical sensor for H2O2 was also fabricated, with a wide linear detection range of 100 nM–200 μM, a low limit of detection of 45 nM and a fast response time (less than 2 s).
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PROCESS BIOCHEMISTRY
·
2018
·
IF 2.616
Junjie Wu,Dewei Xie,Xujun Chen,Ya-Jie Tang,Lixin Wang,Jingli Xie,Dongzhi Wei
The inhibitory mechanism during the reaction between peptides from Phascolosoma esculenta and angiotensin I converting enzyme (ACE) was studied. Thermodynamics features of the peptide-ACE binding reaction measured by isothermal titration calorimetry (ITC) assay, combining with the decrease of ACE inhibition within 24 h implied that Gly-Asn-Gly-Ser-Gly-Tyr-Val-Ser-Arg decomposed during the reaction and played as a substrate-type inhibitor. The hydrolysate Gly-Asn-Gly-Ser-Gly-Tyr-Val (GNGSGYV) without ACE inhibitory activity was identified by UPLC & Q-TOF MS, while the hydrolysate Ser-Arg (SR) showed competitive inhibition of ACE with IC 50 value of 790 μM. However, GNGSGYV and SR have synergistic effect on ACE and result in an ACE inhibitory IC 50 value of 170 μM. The synergistic mechanism illustrated by two-step molecular docking discovered that SR firstly attacked the catalytic Zn of ACE and formed coordinate bond, and then GNGSGYV bound with the arginine of SR and residues along the channel of ACE active site by hydrogen bonds to block the substrate from entering. The circular dichroism spectra also verified that SR and GNGSGYV significantly changed the secondary structure of ACE.
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GLYCOCONJUGATE JOURNAL
·
2016
·Vol. 34
·期 1
·3-12
·
IF 1.828
Wang Dongdong,DanXu,Sun Yuelin,Wu Yuanyuan,Ma Lili,Duan Jinyou
In this study, we synthesized a novel water-soluble low molecular chitosan (LMC) derivative through Vilsmeier reaction and reductive amination reaction. The derivative was characterized by UV-visible spectroscopy, 1 H NMR, FTIR and SEM techniques. The results showed that the derivative effectively reduced the cell viability rate, inhibited cell metastasis, induced cell apoptosis and dissipated mitochondrial membrane potential (ΔΨm). Moreover, the antitumor activity was strengthened with the increase of the degree of substitution of tanshinone I (TanI). These findings provided important support for developing new water-soluble antitumor agent and expand the scope of application of LMC.
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BIOCHEMICAL PHARMACOLOGY
·
2025
·
IF 5.6
Xionghua Sun,Xuelei Wan,Li Chen,Yadong Cui,Xihua Chen,Jian Zhang,Xiaogang Jiang
The senescence of alveolar epithelial cells is one of the characteristics of mitomycin pulmonary toxicity, but the direct target of mitomycin-induced alveolar epithelial cell senescence remains unclear. In this study, a method of small-molecule ligand–protein interaction by pulldown/mass spectrometry identified peroxiredoxin I (Prdx I) as the target of mitomycin-induced alveolar epithelial cell senescence, and mitomycin was shown to significantly inhibit the peroxidase activity of Prdx I. Consequently, the levels of cellular reactive oxygen species (ROS) increased, leading to the activation of mitogen-activated protein kinase kinase 1/2 (MEK1/2)-extracellular signal-regulated protein kinases 1/2 (ERK 1/2) and, accordingly, to the increased expression of p53. Both a Prdx I activator and Prdx I overexpression alleviated mitomycin-induced alveolar cell senescence. A ROS scavenger inhibited MEK1/2-ERK1/2-p53 activation and then attenuated the senescence of alveolar epithelial cells triggered by mitomycin. Thus, Prdx I can serve as the first target of mitomycin-induced alveolar epithelial cell senescence, which might represent a promising approach to reduce mitomycin-induced lung toxicity.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Hongfei Wang,Chao Li,Tie Geng,Na Du,Wanguo Hou
Layered double hydroxides (LDHs) are one type of potential emulsifiers for Pickering emulsions. Surface modification can regulate their surface properties, thereby affecting their emulsifying behavior. However, there is still a lack of full understanding of the impact of surface modification on their surface properties. In the current work, one Mg 3 Al-Cl LDH was modified using oleic acid (OA), obtaining six OA-modified products with different OA loadings. Their contact angles and relative dielectric constants were determined, and their surface properties including the interfacial free energies ( γ ) and solubility parameters ( δ ) were then estimated from the data. Their apparent molar volumes were estimated using the γ and δ data. OA molecules are coated on the LDH surface via the bidentate bonding mode to form monolayers. The OA modification has no obvious impact on the structure and morphology of LDH particles, but can significantly affect their surface properties. This work provides a better understanding of the dependence of surface properties of LDHs on the surface modification.
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Small Methods
·
2024
·Vol. 8
·期 12
·2400143
·
IF 10.7
Shouying Mu,Ye He,YueLi Wang,Wei Chen,Chunyan Lv,Xiaojuan Liang,Weidong Xiang,Zhaopin Chen
Perovskite quantum dots can form various forms such as nanowires, nanorods, and nanosheets through self-assembly. Nanoscale self-assembly can be used to fabricate materials with excellent device properties. This study introduces AuBr 3 into CsPb(Br/I) 3 quantum dots, causing them to assemble into nanowires. The nanowires form because part of Au 3+ is surface-doped to replace Pb 2+ , and the [PbX6] 4− octahedral structure is distorted. The symmetry of the structural surface is broken, and a dipole-moment-induced field is generated, thus promoting self-assembly. Moreover, the presence of Au nanoparticles (NPs) causes a localized surface plasmon resonance and generates strong van der Waals forces that promote self-assembly. Finally, to test other applications of perovskite nanowires, the solution method is used to prepare films by compounding the sample solution and polystyrene (PS) for backlighted displays.
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ACS Applied Materials & Interfaces
·
2012
·
IF 4.525
Jinxing Yu,Na Xu,Zhengping Liu,Liyuan Wang
Maleopimaric acid, cycloaddition reaction product of rosin with maleic anhydride, was reacted with hydroxylamine to afford N-hydroxy maleopimarimide, which was then further esterified with 2-diazo-1-naphthoquinone-4-sulfonyl chloride (2,1,4-DNQ-Cl) to give N-hydroxy maleopimarimide sulfonate. The carboxylic acid group of the compound was then protected by the reaction of this compound with vinyl ether compounds to give the corresponding molecular glass compounds. Upon irradiation to 365 nm light, the 2,1,4-DNQ group undergo photolysis not only to be converted into indene carboxylic acid but also generate a few amount of sulfonic acid which can catalyze the deprotection of the acid labile group. So, novel one-component positive-tone chemically amplified i-line photoresists can be formed by the molecular glass compounds. The lithographic performance of the resists was evaluated using i-line exposure system with high photosensitivity and resolution.
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危险品化学品经营许可证（带存储）