期刊：
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY,2018年23(1):7-25 ISSN：0949-8257
通讯作者：
Hirota, Shun;Lin, Ying-Wu
作者机构：
[Hirota, Shun] Nara Inst Sci & Technol, Grad Sch Mat Sci, 8916-5 Takayama, Nara 6300192, Japan.;[Lin, Ying-Wu] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Hirota, Shun] N;[Lin, Ying-Wu] U;Nara Inst Sci & Technol, Grad Sch Mat Sci, 8916-5 Takayama, Nara 6300192, Japan.;Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
关键词：
Metalloprotein;Metalloenzyme;Protein design;Hydrophobic interaction;Hydrogen bond
摘要：
Noncovalent weak interactions [hydrophobic interaction and hydrogen (H)-bond] play crucial roles in controlling the functions of biomolecules, and thus have been used to design artificial metalloproteins/metalloenzymes during the past few decades. In this review, we focus on the recent progresses in protein design by tuning the noncovalent interactions, including hydrophobic and H-bonding interactions. The topics include redesign and reuse of the heme pocket and other protein scaffolds, design of the heme protein interface, and de novo design of metalloproteins. The informations not only give insights into the metalloenzyme reaction mechanisms but also provide new reactions for future applications.
期刊：
Medical Hypotheses,2018年119:37-40 ISSN：0306-9877
通讯作者：
He, Shu-ya
作者机构：
[He, Shu-ya; Wang, Wu-zhou; He, Jun-yan; Ma, Yun; Qi, Hui-zhou] Univ South China, Med Coll, Hengyang, Peoples R China.;[He, Shu-ya; Wang, Wu-zhou; He, Jun-yan; Ma, Yun] Univ South China, Dept Biochem & Mol Biol, Hengyang 421001, Peoples R China.
通讯机构：
[He, Shu-ya] U;Univ South China, Dept Biochem & Mol Biol, Hengyang 421001, Peoples R China.
摘要：
Radiation-induced enteritis is one of the most common complications in patients under radiotherapy at abdominal or pelvic cavity. Up to 50% of patients treated with pelvic radiotherapy has been reported radiation-induced acute enteritis, and half of them developed chronic enteritis. Overproduction of free radicals, activation of inflammatory pathways and vascular endothelial dysfunction were considered as the primary mechanisms of radiation-induced enteritis. Because probiotics have been demonstrated as a promising potential candidate for treating intestinal diseases, it may be a safer and more effective radioprotector for the enteritis compared to conventional chemical agents with inherent toxicities. Here, we propose that a recombinant Lactobacillus sakei would decrease the complications or symptoms significantly through against different pathogenic mechanisms simultaneously. Therefore, application of higher radiation dose for tumor control would be feasible when co-treating with recombinant Lactobacillus sakei.
期刊：
Chemical Communications,2018年54(4):370-373 ISSN：1359-7345
通讯作者：
Shi, Weiqun
作者机构：
[Lan, Jianhui; Cao, Xingzhong; Yuan, Liyong; Chai, Zhifang; Shi, Weiqun; Tian, Ming] Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.;[Tian, Ming] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.;[Wang, Xiaolin] China Acad Engn Phys, Inst Nucl Phys & Chem, Mianyang 621900, Sichuan, Peoples R China.;[Chai, Zhifang] Soochow Univ, Sch Radiol & Interdisciplinary Sci, Suzhou 215123, Peoples R China.;[Gibson, John K.] Lawrence Berkeley Natl Lab, Chem Sci Div, Berkeley, CA 94720 USA.
通讯机构：
[Shi, Weiqun] C;Chinese Acad Sci, Inst High Energy Phys, Lab Nucl Energy Chem, Beijing 100049, Peoples R China.
摘要：
The preliminary results described here show that the adsorbability of uranyl ions by a highly stable MOF UiO-66 can be drastically enhanced by tailoring the missing-linker defects in this MOF. The combination of defect-induced functionality improvement with the acid-resistant nature of UiO-66 substantiates the applicability of this material for actinide capture from acidic media.
摘要：
The inelastic responses of thermoplastic polyurethane/attapulgite (AT) elastomeric composites were studied by an elastic-testing machine combining with an infrared camera during loading–unloading cycles, in which the former detected the mechanical properties while the latter reflected the thermal effects of deformation. For both unfilled and filled polyurethanes, some significant inelastic features were noticed that in the first cycle hysteresis and most stress softening occurred, and the corresponding temperature variation was partly reversible. However, in the following cycles, the specimen approached a steady state, therefore, stress–strain curve and the corresponding temperature variation was totally reversible. It was also showed that in filled materials the inelastic effects were becoming more obvious with the increase of AT concentration. The results can be explained by chain slippage of the hard micro-domain existing in soft segments of polyurethane, which produces irreversible friction dissipation during the initial loading process.
期刊：
Analytical and Bioanalytical Chemistry,2018年410(28):7385-7394 ISSN：1618-2642
通讯作者：
Wang, Yong-Sheng
作者机构：
[Zhou, Bin; Chen, Si-Han; Xue, Jin-Hua; Huang, Yan-Qin; Fu, Sha; Wang, Yong-Sheng] Univ South China, Coll Publ Hlth, West Changsheng Rd 28, Hengyang 421001, Hunan, Peoples R China.;[Xiao, Xi-Lin] Univ South China, Coll Chem & Chem Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Wang, Yong-Sheng] U;Univ South China, Coll Publ Hlth, West Changsheng Rd 28, Hengyang 421001, Hunan, Peoples R China.
关键词：
Colorimetric sensing;Hg2+-Au0/Au+ interaction;Mercury;Partly oxidized Au species;Peroxidase-like activity;Protamine-gold nanoclusters
摘要：
We certify that protamine-gold nanoclusters (PRT-AuNCs) synthesized by one-pot method exhibit peroxidase-like activity. The catalytic activity of PRT-AuNCs followed typical Michaelis-Menten kinetics and exhibited higher affinity to 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate compared to that of natural horseradish peroxidase. Meanwhile, we found that Hg(II) could dramatically and selectively enhance the peroxidase-like activity of PRT-AuNCs, and the enhanced mechanism by Hg(II) was demonstrated to be generation of the cationic Au species and the partly oxidized Au species (Au(delta+)) by Hg(2+)-Au(0)/Au(+) interaction. Based on this finding, quantitative determinations of Hg(II) via visual observation and absorption spectra were achieved. The proposed strategy displays high selectivity that arises from the strong aurophilic interaction of mercury towards gold. Moreover, the developed method is highly sensitive with a wide linear range and low detection limit of 1.16 nM. This strategy is not only helpful to develop effective nanomaterials-based artificial enzyme mimics but also irradiative to discover new applications of artificial mimic enzymes in bio-detection, medical diagnostics, and biotechnology. Graphical abstract Protamine-gold nanoclusters (PRT-AuNCs) synthesized by one-pot method exhibit peroxidase-like activity. Hg(II) can stimulate the peroxidase-like activity of PRT-AuNCs selectively, enhancing their ability to catalyze the chromogenic reaction of TMB by H2O2.
期刊：
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,2018年18(12):8160-8168 ISSN：1533-4880
通讯作者：
Li, Le
作者机构：
[Lu, Wei; Liu, Ling; Chen, Tuo; Li, Le] Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.;[Ding, Dexin; Lu, Wei; Li, Le; Dai, Zhongran] Univ South China, Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.;[Tang, Shuangyang] Univ South China, Inst Pathogen Biol, Hengyang 421001, Peoples R China.;[Cao, Chen] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Li, Le] U;Univ South China, Sch Publ Hlth, Hengyang 421001, Peoples R China.;Univ South China, Hunan Prov Key Lab Green Dev Technol Extremely Lo, Hengyang 421001, Peoples R China.
关键词：
Magnetic Graphene Oxide;Calix[6]arene;U(VI);Adsorption
摘要：
Magnetic graphene oxide/calix[6] arene (MGO-C6) composites were prepared and then characterized by Fourier transform infrared spectroscopy, Scanning electron microscope, X-ray diffraction and Thermo gravimetric analyzer, the adsorption of U(VI) by MGO-C6 from aqueous solution was investigated as a function of pH, contact time, initial U(VI) concentration and adsorbent dosage. The maximum adsorption rate of MGO-C6 can reach up to 93.21%, which was highly efficient for the removal of U(VI) under the condition of 1 mg/L initial uranium concentration. In addition, the selective adsorption experiment showed that MGO-C6 had an overall preference for U(VI). Adsorption process of MGO-C6 fitted well with the pseudo-second-order kinetic kinetics and the Langmuir isotherm model. The thermodynamic parameters illustrated that the adsorption process was endothermic and spontaneous. This work demonstrated that MGO-C6 was a promising adsorbent for removal of U(VI) from low concentration uranium-containing wastewater.
摘要：
Purpose The purpose of this paper is to study the tribological properties of a thiazole derivatives (T561), overbased alkyl benzene calcium sulfonate (T106A) compounded with T561 and overbased alkyl benzene magnesium sulfonate (T107) compounded with T561 in rapeseed oil (RSO). Design/methodology/approach A four-ball machine was used to evaluate the tribological properties of each compound and their combinations with T561 in RSO. Scanning electron microscopy, EDX and X-ray photoelectron spectroscopy were applied to analyze the tribofilm formed on the worn surfaces. Findings Results of tribotesting demonstrated that synergistic effects exist between the overbased sulfonates, T106A and T107, and the thiazole derivative, T561. The texts of tribofilm indicated that iron sulfide and iron oxides exist in T561 single agent lubricant film and two composite additives lubricant film, and no sulfates were detected. It suggested that the addition of alkyl benzene sulfonate did not hinder the formation of iron sulfides and iron oxides. Meanwhile, CaSO4 (MgSO4) and CaCO3 (MgCO3) were detected on the worn surface of the composite additives, which were not detected on the single agent friction surface. Originality/value A tribofilm mainly contains CaSO4 (MgSO4) and CaCO3 (MgCO3) formed on the worn surfaces, which is responsible for excellent extreme pressure and anti-wear properties of the compound agents because of their high melting point and high shear stress.
摘要：
The inclusion complex (sulfated-β-CD@NAA) of sulfated β-cyclodextrin and α-naphthylacetic acid was synthesized for adsorption of low concentrations of thorium from aqueous solutions. The structure and property of sulfated-β-CD@NAA were characterized by Fourier transform infrared spectroscopy, thermogravimetric, X-ray diffraction, proton nuclear magnetic resonance, specific surface area measurement and scanning electron microscopy. The characterization analysis confirmed the formation of new solid phase. The results indicated that α-naphthylacetic acid embedded into the cavity of sulfated β-cyclodextrin partly from the secondary face and the thermal stability of inclusion complex was significantly increased. The experiments were designed by Box–Behnken design combined with response surface methodology. The adsorption parameters of pH value, contact time, initial concentration were used as the independent variables and their effects were investigated on the Th(IV) adsorption capacity. Second-order polynomial regression models were derived and analysis of variance was utilized to judge the adequacy of the chosen models. The maximum Th(IV) adsorption capacity (12.75 mg g−1) was achieved under the following conditions: pH value 2.5, contact time 35 min, initial concentration 30 mg L−1. Prediction of models was in good agreement with experimental results. The experimental adsorption kinetic data followed a pseudo-second-order equation with the correlation of 0.9996, indicating the chemical adsorption. The obtained equilibrium isotherm data were fitted well with Langmuir model in the concentration range considered. The thermodynamic parameters (∆H0 < 0, ∆S0 < 0, ∆G0 < 0) indicated that the adsorption process was exothermic and spontaneous. Regeneration of Th(IV)-loaded sulfated-β-CD@NAA with 0.1 M HNO3 solution, and the regenerated sulfated-β-CD@NAA can be reused for adsorption of Th(IV).
摘要：
The coordination reaction of thorium (IV) with a ditopic bidentate ligand to form supramolecular polymer was studied by resonance light scattering (RLS) spectra, second-order scattering (SOS) spectra and frequency-doubling scattering (FDS) spectra, respectively. The ditopic bidentate ligand is isophthalaldehyde-tetrapyrrole (IPTP). It was synthesized through a condensation reaction of isophthalaldehyde with pyrrole. The formation of supramolecular polymer results in remarkable intensity enhancements of the three light scattering signals. The maximum scattering wavelengths of RLS, FDS and SOS were 290, 568 and 340 nm, respectively. The reaction was used to establish new light scattering methods for the determination of thorium (IV) by using IPTP as probe. Under optimum conditions, the intensity enhancements of RLS, SOS and FDS were directly proportional to the concentration of thorium (IV) in the ranges of 0.01 to 1.2 mu g mL(-1), 0.05 to 1.2 mu g mL(-1) and 0.05 to 1.2 mu g mL(-1), respectively. The detection limits were 0.003 mu g mL(-1), 0.012 mu g mL(-1) and 0.021 mu g mL(-1), respectively. The methods were suitable for analyzing thorium (IV) in actual samples. The results show acceptable recoveries and precision compared with a reference method. (C) 2017 Elsevier B.V. All rights reserved.
摘要：
The authors describe an ultrasensitive amperometric enzymatic assay for uranyl ion. It is based on the use of mesoporous silica nanoparticles (mesoSiNPs) loaded with Methylene Blue (MB) and functionalized with an UO2(II)-dependent DNAzyme. The electroactive label MB was sealed in the inner pores of the mesoSiNPs along with double stranded DNA (containing the DNAzyme and the substrate strand). In the presence of UO2(II), the DNAzyme is actived to cleave the substrate strands. This leads to the cleavage of the caps and the release of MB from the mesoSiNPs. The amount of released MB depends on the concentration of UO2(II) and can be determined amperometrically, best at a working voltage of −0.25 V (vs SCE), by using a chitosan coated carbon paste electrode. Response is linear in the 20 pM to 0.1 nM UO2(II) concentration range, and the detection limit is as low as 0.15 pM. Recoveries from spiked samples varied from 91.3 to 99.4%. The assay is highly specific, selective, and not interfered by other metal ions. Graphical abstract(a) Schematic representation of the synthesis, MB loading, and dsDNA Binding of the mesoSiNPs, as well as the release of MB from mesoSiNPs in the presence of UO2²⁺. (b) Schematic illustration of the stepwise DNAzyme-based electrochemical sensor for uranium detection.
