PROCESS BIOCHEMISTRY
·
2023
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IF 4.4
Meng Zhang,QingYan Li,Feiyu Fan,Fuping Lu,XueLi Zhang
This study highlights an effective strategy based on the synergistic complementarity of metabolic engineering and adaptive evolution.First, the chassis strain YL013 was obtained by deleting five acyl-CoA oxidase genes to reduce the degradation of γ-decalactone(GDL). Then, adaptive laboratory evolution with increasing concentrations of γ-decalactone was employed to obtain the strain YL013–250 with increased γ-decalactone tolerance of up to 250 mg/L. Moreover, this strain produced 664.5 mg/L γ-decalactone, representing a 142 % improvement over the parental strain YL013. Furthermore, four candidate fatty acyl-CoA synthetase genes, FAA1 , FAA2 FAA3 and FAT1, were modulated using the strong, constitutive TEFin promoter to investigate their roles in GDL production. The results showed that overexpression of FAA1 , FAA2 and FAA3 can effectively improve the ability of Yarrowia lipolytica to synthesize GDL using ricinoleic acid as substrate, among which overexpression of FAA1 had the most significant effect on GDL yield. Finally, gene of alcohol acyltransferase ( AAT1 ) from Prunus persica was introduced into Y. lipolytica , leading to a GDL titer of 2.2 g/L, which was a 1.32-fold increase compared with the parental strain without AAT1 . Taken together, this study provides a combinatorial strategy to improve GDL production through rational regulation of pathway genes and non-rational adaptive laboratory evolution.
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CARBOHYDRATE POLYMERS
·
2023
·
IF 11.2
Tingting Zhang,Hao He,Qing Xu,Jiasheng Lv,Chaoyi Wu,Yefei Zhou,Zhenjiong Wang
Lactonic sophorolipid (LSL) exhibits numerous surfactant activities, such as emulsification , wetting action, dispersion effect, and oil-washing activities. Nevertheless, LSLs have poor water solubility, which restrains their application in the petroleum industry . In this research, a new compound, lactonic sophorolipid cyclodextrin metal-organic framework (LSL-CD-MOFs), was obtained by loading LSL into γ-cyclodextrin metal-organic frameworks (γ-CD-MOFs). The LSL-CD-MOFs were characterized by N 2 adsorption analysis, X-ray powder diffraction analysis, Fourier transform infrared spectroscopy , and thermogravimetric analysis . Loading LSL into γ-CD-MOFs significantly increased the apparent water solubility of LSL. However, the critical micelle concentration of LSL-CD-MOFs was similar to that of LSL. Furthermore, LSL-CD-MOFs effectively reduced the viscosities and improved the emulsification indices of oil–water mixtures. Oil-washing tests, which were conducted using oil sands, revealed that the LSL-CD-MOFs yielded an oil-washing efficiency of 85.82 % ± 2.04 %. Overall, γ-CD-MOFs are promising carriers for LSL, and LSL-CD-MOFs are a potential, low-cost, new, green surfactant for enhanced oil recovery.
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CARBOHYDRATE POLYMERS
·
2021
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IF 9.381
Guihua Fang,Qiuxiang Wang,Xuewen Yang,Yu Qian,Guowei Zhang,Bo Tang
Anterior uveitis is a sight-threatening inflammation inside the eyes. Conventional eye drops for anti-inflammatory therapy need to be administered frequently owing to the rapid elimination and corneal barrier. To address these issues, polypseudorotaxane hydrogels were developed by mixing Soluplus micelles (99.4 nm) and cyclodextrins solution. The optimized hydrogels exhibited shear-thinning and sustained release properties. The hydrogels exhibited higher transcorneal permeability coefficient (P app , 1.84 folds) than that of drug solutions. Moreover, animal study indicated that the hydrogels significantly increased the precorneal retention (AUC, 21.2 folds) and intraocular bioavailability of flurbiprofen (AUC Aqueous humor , 17.8 folds) in comparison with drug solutions. Importantly, the hydrogels obviously boosted anti-inflammatory efficacy in rabbit model of endotoxin-induced uveitis at a reduced administration frequency. Additionally, the safety of hydrogels was confirmed by cytotoxicity and ocular irritation studies. In all, the present study demonstrates a friendly non-invasive strategy based on γ- CD-based polypseudorotaxane hydrogels for ocular drug delivery.
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高影响因子
Environmental Science-Nano
·
2021
·Vol. 8
·期 12
·3833-3845
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IF 8.131
Tingting Li,Yangsai Lyu,Jia Li,Chengyan Wang,Ningning Xing,Jie Yang,Min Zuo
Micromotors have held great promise for environmental treatment due to their unique self-propelled movement that can significantly accelerate the chemical process in solution. Herein, we have developed a new AO–Mn2O3/γ-AlO(OH) fluorescent micromotor using renewable and uniquely hollow kapok fibers as biological templates. The AO–Mn2O3/γ-AlO(OH) micromotor was powered by the asymmetric decomposition of hydrogen peroxide fuel catalyzed by Mn2O3, reaching a maximum speed of 139.6 μm s−1 in 3% H2O2 solution. The micromotor revealed a markedly enhanced fluorescence effect compared to both pure AO solution and non-micromotor counterparts and exhibited excellent selectivity and sensitivity for Hg2+ detection. The detection range and limit for Hg2+ were 5 × 10−8–5 × 10−5 M and 2.25 × 10−8 M, respectively. The enhanced Hg2+ sensing benefited from the synergy of enhanced fluorescence via the inhibition of the dimerization of AO, fluorescence quenching induced by charge transfer and the enhanced contact between the micromotor and Hg2+ ions resulted from the self-propelled motion. This micromotor-assisted fluorescence detection idea provided a new strategy for the development of sensors with high sensitivity.
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Molecular Catalysis
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2023
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IF 4.6
Yanzhao Gao,Xianglei Meng,Shiqi Huang,Hui Wu,Liantao Jiang,Yu Zhou,Yuting Song,Yanyan Diao
Gamma alumina is widely utilized for preparing the supported noble metal catalysts for the hydrogenation reaction. It is an effective strategy to improve the catalytic performance of catalysts via modifying gamma alumina with alkaline earth metal to regulate its surface acidity and electronic properties. Herein, Pd catalysts supported by Al 2 O 3 and Mg-modified Al 2 O 3 are synthesized via the wet impregnation method, and the effects of MgO doping on the structure, composition, and surface acidity of Pd/γ-Al 2 O 3 catalysts are investigated via X-ray diffraction patterns (XRD), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Temperature programmed desorption (TPD). The results show that Pd/MgO-Al 2 O 3 –2 (γ-Al 2 O 3 modified with 2 wt% Mg) has more metallic state palladium and weak acid sites and exhibits the best catalytic performance for the hydrogenation of perfluoro-4-methyl-2-pentene (D1). Density functional theory (DFT) calculations on Pd/Al 2 O 3 and Pd/MgO-Al 2 O 3 –2 catalysts are also performed to further explore the mechanism of D1 hydrogenation. The studies for Gibbs free energy of the potential reaction steps and intermediates reveal a complex process to generate the target product C 6 F 12 H 2 , and the rate-determining-step is the addition of the first hydrogen on the second carbon of perfluoro-4-methyl-2-pentene molecule.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Mingjing Yin,Shanshan Liu,Xinying Ma,Xiangyan Meng,Mingyong Chao
Eugenol, an active substance widely used in the medical, food, and cosmetic industries, has garnered increasing attention due to its potential adverse effects on human health resulting from excessive use. In this study, a sensitive sensor for the determination of eugenol was developed by electropolymerizing γ-aminobutyric acid ( g ABA) onto the surface of a glassy carbon electrode (GCE). Experiments showed that the poly γ-aminobutyric acid ( pg ABA) membrane exhibited excellent electrocatalytic activity for the oxidation of eugenol, and its oxidation peak current was greatly increased. Under optimized conditions, the oxidation peak current of eugenol was linearly proportional to its concentration in a range of 0.6–100 μmol/L, with a correlation coefficient of 0.9985 and a detection limit of 0.2 μmol/L. The sensor’s ability to detect eugenol in various authentic samples, with recovery rates ranging from 98.0 % to 101.3 %, attests to its great potential for practical application.
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RENEWABLE ENERGY
·
2021
·
IF 8.001
Junwei Yao,Xiaobao Xie,Qingshan Shi
In this work, we report that FeCl 3 , a benign Lewis acid, could be used as a catalyst in the γ-valerolactone (GVL)/H 2 O solvent system to facilitate efficient pretreatment of Chinese silvergrass. The results showed that approximately 87.8% of xylan and 75.8% of lignin were removed by 80% GVL under 170 °C using 50 mM FeCl 3 as a catalyst. The solubilized carbohydrate fractions in the pretreatment liquor were mainly composed of monosaccharides (glucose and xylose) rather than oligosaccharides (glucose oligomers and xylose oligomers) and inhibitors (furfural, hydroxymethylfurfural, formic acid and acetic acid). Moreover, FeCl 3 decreased the transesterification of GVL with hydroxyl groups on the cellulose surface and resulted in more easily degraded cellulose. Approximately 96.5% of cellulose and 92.2% of xylan in the pretreated Chinese silvergrass were converted to fermentable monosaccharides by 10 FPU/g cellulases . This study indicated that FeCl 3 -catalyzed GVL solvent could efficiently deconstruct biomass and increase the cellulose digestibility, which provided a novel, GVL-based pretreatment system for processing biomass.
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Theranostics
·
2021
·
IF 11.556
Fangyuan Zhou,Shikui Yang,Chao Zhao,Wangwang Liu,Xufeng Yao,Hui Yu,Xiaolian Sun,Yi Liu
Rationale: Precise treatment of tumors is attracting increasing attention. Molecular probes simultaneously demonstrating the diagnostic signal and pharmacological effect in response to tumor microenvironment are highly desired. γ-glutamyl transpeptidase (GGT) is a biomarker with significantly up-regulated expression in the tumor area. We developed a GGT responsive near-infrared (NIR) nanoassembly for tumor-specific fluorescence imaging-guided photothermal therapy. Methods: The GGT responsive NIR probe was constructed by conjugating GGT-specific substrate γ-glutamic acid (γ-Glu) with cyanine fluorophore (NRh-NH 2 ) via amide reaction. The resulting NRh-G spontaneously assembled into nanoparticles (NRh-G-NPs) around 50 nm. The NPs were characterized and the properties evaluated in the presence or absence of GGT. Subsequently, we studied fluorescence imaging and photothermal therapy of NRh-G-NPs in vitro and in vivo . Results: NRh-G-NPs, upon specific reaction with GGT, turned into NRh-NH 2 -NPs, showing a ~180-fold fluorescence enhancement and excellent photothermal effect recovery. NRh-G-NPs could selectively light up U87MG tumor cells while their fluorescence was weak in L02 human normal liver cells. The NPs also showed excellent tumor cell ablation upon laser irradiation. After intravenous injection into tumor-bearing mice, NRh-G-NPs could arrive in the tumor area and specifically light up the tumor. Following laser irradiation, the tumor could be completely erased with no tumor reoccurrence for up to 40 days. Conclusions: NRh-G-NPs were specifically responsive to GGT overexpressed in U87MG tumor cells and selectively lit up the tumor for imaging-guided therapy. Besides, the recovery of photothermal property in the tumor area could improve cancer therapy precision and decreased side effects in normal tissues.
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PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 32
·43815-43830
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IF 4.223
Liu Yaxin,Ma Yongwen,Wan Jinquan,Wang Yan,Sun Jian,Xue Yangyang
In this work, Co-Ce-Zr/γ-Al 2 O3 3 particle electrodes were prepared for the efficient degradation of ciprofloxacin (CIP). Co-Ce-Zr/γ-Al 2 O 3 particle electrodes were analyzed with a scanning electron microscope (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence Spectrometer (XRF), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). According to the results, significant amounts of Co 3 O 4 , CeO 2 , and ZrO 2 were formed on the Co-Ce-Zr/γ-Al 2 O 3 particle electrodes. It was shown that when the conditions of the reaction system were at pH=6, conductivity of 4 ms/cm, current of 0.2 A, initial pollutant concentration of 100 mg/L, and material dosage of 15 g, CIP could be completely degraded within 40 min, and the energy consumed in the reaction was 41.3 kWh/kg CIP. The rate of total organic carbon (TOC) removal by Co-Ce-Zr/γ-Al 2 O 3 particle electrodes was recorded to be approximately 52.6%. Using a response surface methodology, we explored the optimal operating conditions. At the same time, we also explored the influence of inorganic anions in water and actual water medium on the rate of CIP removal. In addition, the ESR data proved that the main active substance in the reaction system was ·OH. The degradation intermediates were investigated, and the possible mechanism was proposed. Thus, this research provided a new solution for the treatment of antibiotic-containing wastewater.
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ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Zuojun Wei,Qing Li,Yuran Cheng,Mei Dong,Zuyi Zhang,Xinmiao Zhu,Yingxin Liu,Yong Sun
CoRe bimetallic catalysts with low loading were designed for hydrodeoxygenation of levulinic acid to γ-valerolactone. Results show that the 1 wt % Co0.5Re0.5/TiO2 catalyst achieved the highest yield of γ-valerolactone (>99%) at 220 °C, 3 h, a 1,4-dioxane solvent and Co/levulinic acid molar ratio of 1:1760, with a turnover frequency (TOF) of 1328 h–1. The catalyst can be reused four times with only slight activity loss. The catalyst was characterized with various physicochemical measurements, and its adsorption styles with H2 and levulinic acid were calculated by density functional theory. The results reveal that four main factors are related to its excellent catalytic performance. First, the Re oxides synergize with Co by spillover of the dissociated H atoms, which increases the apparent dispersion of Co and promotes the reaction. Second, the low loading of 1 wt % allowed the metal nanoparticles to be well dispersed with a very fine size of ca. 1.24 nm, which may expose more active sites to the substrate and result in a higher catalytic efficiency. Third, CoRe formed an amorphous alloy with the formula Co-ReO1.6, which showed a synergistic effect during the reaction. Finally, the TiO2 support was nonporous and hydrophilic, which would be beneficial for the mass diffusion of the reaction components to be adsorbed/desorbed onto the vicinity of the metallic active sites and lead to a high TOF in the hydrodeoxygenation process.
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Journal of Water Process Engineering
·
2020
·
IF 3.465
Yu Li,Luchao Wu,Yun Wang,Peng Ke,Jie Xu,Baohong Guan
Ozone decomposition into free radicals, which can be facilitated by enhancing electron transfer between ozone and catalyst, is an important segment in catalytic ozonation. We doped cerium uniformly on γ-Al 2 O 3 with an impregnation–calcination method to enhance electron transfer in catalytic ozonation of phenol in aqueous solution. The removal efficiency of phenol is raised from 39.7% by ozonation alone to 46.3% by catalytic ozonation with Ce/Al 2 O 3 in 50 min reaction. A higher Ce 3+ /Ce 4+ ratio in Ce/Al 2 O 3 witnesses a higher electron transfer rate in catalytic ozonation and thus a higher degradation efficiency of phenol, illustrating that the activity of Ce/Al 2 O 3 depends on the valence state of Ce. The electron transfer cycle is formed by the electron donation from Ce 3+ to ozone molecule and the electron acceptance of Ce 4+ from adjacent lattice oxygen. After getting the electron, the ozone molecule is decomposed to generate free radical of ·OH on the surface of Ce/Al 2 O 3 . The continuous flow experiments exhibit a stable and high catalytic activity of Ce/Al 2 O 3 for catalytic ozonation, implying the feasibility in practical application.
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CATALYSIS COMMUNICATIONS
·
2020
·
IF 3.612
Jingru Wang,Yingyong Wang,Xili Tong,Yunwei Wang,Guoqiang Jin,Xiangyun Guo
A 3 wt% Ir/SiC catalyst prepared by the wet impregnation method showed excellent catalytic activity and stability for the aqueous hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) in a batch reactor system. LA was completely converted to GVL at 50 °C and 0.2 MPa of H 2 pressure with 100% selectivity and a high turnover frequency (TOF) of 333 h −1 . The high activity of Ir/SiC catalyst could be related to the Schottky-type contact between Ir and SiC solid phases, which promotes electron transfer between support and metal. Due to the excellent acid resistance of SiC support, the Ir/SiC catalyst showed high catalytic stability and nearly no loss of activity after 5 consecutive catalytic operation cycles.
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