Frontiers in Bioengineering and Biotechnology
·
2020
·
IF 3.644
Hou Feifei,Wan Yupeng,Gan Qi,Xian Mo,Huang Wei
8-Azaguanine (1) is a special 1,2,3-triazole containing natural product that possesses potent antibacterial and antitumor activities. In the present study, the entire 8-azaguanine biosynthetic gene cluster was located from Streptomyces CGMCC4.1633. Targeted gene disruption, heterologous expression analysis, and feeding experiments identified crucial genes for 8-azaguanine production. Moreover, we characterized the structure of two novel metabolites, analyzed NO (or reactive nitrogen species) related genes 8-azgA/B and radical SAM enzyme homologous 8-AzgG, and verified the non-enzymatic ring formation reaction of 8-azaguanine 1,2,3-triazole. All of the data and presumptions provide insight into the timing and mechanism of the enzymatic and non-enzymatic pathway that produce 8-azaguanine-type 1,2,3-triazole.
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PubMed
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 5
·997-1006
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IF 2.578
Xinyao Lv,Wei Zeng,Zhiwang Yang,Yaoxia Yang,Yun Wang,Ziqiang Lei,Jinling Liu,Denglong Chen
A novel zeolitic imidazolate framework (ZIF-8) nanoparticles@polyphosphazene (PZN) core-shell architecture was synthesized, and then, ZIF-8@PZN and ammonium polyphosphate (APP) were applied for increasing the flame retardancy and mechanical property of epoxy resin (EP) through a cooperative effect. Herein, ZIF-8 was used as the core; the shell of PZN was coated to ZIF-8 nanoparticles via a polycondensation method. The well-designed ZIF-8@PZN displayed superior fire retardancy and smoke suppression effect. The synthesized ZIF-8@PZN observably raised the flame retardancy of EP composites, which could be demonstrated by thermogravimetric analysis (TGA) and a cone calorimeter test (CCT). The chemical structure of ZIF-8@PZN was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Compared with pure epoxy, with the incorporation of 3 wt% ZIF-8@PZN and 18 wt% APP into the EP, along with 80.8%, 72.6%, and 64.7% decreased in the peak heat release rate (pHRR), the peak smoke production rate (pSPR), and the peak CO production rate (pCOPR), respectively. These suggested that ZIF-8@PZN and APP generated an intumescent char layer, and ZIF-8@PZN can strengthen the char layer, resulting in the enhancement in the flame resistance of EP.
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APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Aotian Gu,Jiuyu Chen,Qianhong Gao,Muhammad Musaa Khan,Peng Wang,Yan Jiao,Zongxiang Zhang,Ying Liu,Yi Yang
The high effective Ag/ZIF-8@ZIF-67 core-shell composite was fabricated by a convenient strategy and applied in the reduction of 4-nitrophenol. The obtained samples were fully characterized by transmission electron microcopy (TEM), element mapping, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and the like. Catalytic experiments showed that the Ag/ZIF-8@ZIF-67 exhibit superior catalytic activity in the reduction of 4-nitrophenol and another two nitroaromatic compounds. The apparent rate constant (K app ) and the conversion frequency (TOF) of Ag/ZIF-8@ZIF-67 0.4 for 4-nitrophenol were 12.22 × 10 −3 s −1 and 5.611 min −1 , respectively, and preserved high catalytic performance after four cycles. The catalytic activity of Ag/ZIF-8@ZIF-67 was significantly increased compared to Ag/ZIF-8, which was mainly attributed to the high specific surface area of ZIF-8@ZIF-67, the synergy of ZIF-8 core and ZIF-67 shell and the restriction of pores to Ag NPs.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Xiao Li,Shifan Yu,Kun Li,Chao Ma,Jing Zhang,Hui Li,Xiao Chang,Lei Zhu,Qingzhong Xue
It is imperative to research CO 2 separation membrane in terms of the issues of greenhouse gas emission. In this work, zeolitic imidazolate frameworks-8 (ZIF-8) particles in situ inserted by multiwalled carbon tubes (MWCNTs) (MWCNTs@ZIF-8) were embedded into Pebax matrix to fabricate mixed matrix membranes (MMMs). The incorporated ZIF-8 particles increased the free volume of membranes, resulting in the improvement of the CO 2 permeability. The functionalized MWCNTs in situ inserted into ZIF-8 particles not only avoided the aggregation of ZIF-8 particles but also enhanced the CO 2 adsorption property, resulting in the improvement of the CO 2 /N 2 selectivity. Furthermore, the MWCNTs can provide rapid transport channels for CO 2 molecules between two adjacent ZIF-8 particles and high mechanical properties for membranes. As a result, the MMMs with 8 wt% MWCNTs@ZIF-8 exhibited an excellent separation performance with CO 2 permeability of 186.3 Barrer and CO 2 /N 2 selectivity of 61.3, which surpassed the 2008 Robeson upper-bound. This study provided a new strategy for preparing high-performance CO 2 separation membranes.
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Analytical Methods
·
2020
·Vol. 12
·期 38
·4657-4664
·
IF 2.596
Linhua Yi,Yinghua Yan,Keqi Tang,Chuan-Fan Ding
As a member of MOFs, Zn-MOFs (ZIF-8) are seldom used in phosphopeptide enrichment because ZIF-8 is soluble in acid solutions. Therefore, properly designing a novel strategy to overcome the defect of ZIF-8 is necessary. In this study, a novel multifunctional nanoprobe was designed by uniting magnetic core, titania shell and hydrophilic metal–organic frameworks (named as Fe3O4@PDA@mTiO2@PEI-g-ZIF-8). Integrating the strategies of hydrophilic interaction affinity chromatography (HILIC), immobilized metal ion affinity chromatography (IMAC) and metal oxide affinity chromatography (MOAC), the Fe3O4@PDA@mTiO2@PEI-g-ZIF-8 mesoporous microspheres can enrich phosphorylated peptides and glycosylated peptides simultaneously. Fe3O4@PDA@mTiO2@PEI-g-ZIF-8 has high selectivity (maximum molar ratio β-casein/HRP : BSA = 1 : 1000), low detection limit (2 fmol) towards phosphopeptides and glycopeptides. Besides, the Fe3O4@PDA@mTiO2@PEI-g-ZIF-8 also exhibited a fine performance in the actual sample detection. In the experiment, taking saliva as a sample, 16 phosphorylated peptides were identified, and from a human serum sample, 4 phosphorylated peptides were selectively identified. All in all, the materials show great potential in the future study of phosphoproteomics and glycoproteomics.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 32
·13534-13541
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IF 3.288
Xin Gao,Qiang Ma,Zhengwei Jin,Pei Nian,Zheng Wang
Surfactant-stabilized oil–water emulsions are especially difficult pollutants to eliminate. Membrane technology has been extensively applied for oily water treatment. However, the immutable wettability limits its application for separating different types of emulsions. In this work, novel zeolitic imidazolate framework-8 (ZIF-8) film-coated stainless-steel meshes with switchable superlyophobicity were fabricated for all types of emulsion separations. The membranes exhibited outstanding superoleophobicity (161°) and superhydrophobicity (153°). By switching the superlyophobicity through a prewetting process, the membrane could selectively remove oil droplets in surfactant-stabilized oil-in-water emulsions via superoleophobicity and water droplets in surfactant-stabilized water-in-oil emulsions via superhydrophobicity. Upon further modification of the membrane with polyvinyl alcohol, high-flux emulsion separations were achieved. This work provides a foundation for the development of metal–organic framework (MOF) membranes for selective high-flux emulsion separations.
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Journal of Materials Chemistry B
·
2020
·Vol. 8
·期 28
·6128-6138
·
IF 5.344
Ruihong Xie,Peng Yang,Shaojun Peng,Yongbin Cao,Xianxian Yao,Shengdi Guo,Wuli Yang
In recent years, zeolitic imidazolate framework-8 (ZIF-8) has become an attractive metal organic framework (MOF) material in drug delivery for cancer chemotherapy. However, as a drug delivery system, ZIF-8 still shows some disadvantages, such as short blood circulation time and poor tumor targeting, leading to reduced drug delivery efficiency and unsatisfactory treatment. Herein, we developed a phosphorylcholine-based zwitterionic copolymer coated ZIF-8 nanodrug (DOX@ZIF-8@P(MPC-co-C7A)), and the obtained nanodrug was prepared via a charge-conversional zwitterionic copolymer coating on DOX@ZIF-8 composites. In this system, DOX was encapsulated in the framework of ZIF-8, which could reduce the drug leakage in the bloodstream. The phosphorylcholine-based zwitterionic copolymer effectively extended the blood circulation time, resulting in enhanced tumor accumulation of the nanodrug. Once the nanodrug reached the tumor site, the surface charge of the system could rapidly convert to positive, resulting in an enhanced tumor cellular uptake. Finally, in the acidic environment inside intracellular organelles, DOX will be released rapidly for chemotherapy owing to the fast disintegration of ZIF-8 frameworks. Therefore, the obtained nanodrug could effectively inhibit the growth of A549-bearing tumors (93.2% tumor inhibition rate) with negligible side effects. Overall, this work significantly improved the drug delivery efficiency of ZIF-8, which may pave the way for the biomedical applications of ZIF-8 crystals in anti-tumor drug delivery.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yunning Chen,Xiaoyan Zhang,Lingling Wang,Xueying Cheng,Qingkun Shang
An Fe-HQLC/TiO 2 (HQLC: 8-hydroxyquinoline-7-carboxylic) flower composite was synthesized and characterized. Phenol and four antibiotics: ciprofloxacin, tetracycline, amoxicillin and erythromycin can be efficiently and rapidly degraded by the Fe-HQLC/TiO 2 flower under visible light. The results indicated that more than 95% of the four antibiotics could be removed within 15 min. The photodegradation products of the four antibiotics were studied by high-performance liquid chromatography and high-resolution liquid chromatography-mass spectrometry. It was found that the adsorption characteristics of the antibiotics and their degradation products had a great influence on the photocatalytic activity of the photocatalyst and on the degradation rate of the antibiotics in recycling. Although the Fe-HQLC/TiO 2 flower did not degrade the four antibiotics completely, the parent structure of the antibiotics was destroyed to some extent. Therefore, the environmental toxicity and cytotoxicity of the antibiotics were significantly decreased. Compared with other related research works, there are a few photocatalysts capable of efficient and rapid removal of antibiotics.
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JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 55
·期 8
·3167-3180
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IF 3.442
Ren Lipei,Yu Yan,Yang Yuan,Zhang Qian,Xiao Xingfang,Liu Ruina,Xu Weilin
Zeolitic imidazolate framework-8 (ZIF-8) is regarded as an excellent adsorbent material for removing diverse toxic or hazardous gases. However, its milli- to nanoscale size typically restricts its applications. In this study, we demonstrate the ZIF-8 nanocrystals assembled on TiO 2 -coated activated carbon fiber felts via atomic layer deposition (ZIF-8@ALD-ACF felts), which can be used as a highly efficient adsorbent for HCHO removal. Using the TiO 2 -coated ACF felts as substrates via ALD can provide large number of growth sites for ZIF-8 nanocrystals, which results in fast and highly efficient removal of HCHO. Furthermore, ZIF-8@ALD-ACF felts achieve a highly efficient removal of HCHO under ultraviolet (UV) light. HCHO can be completely removed at high concentration within 110 min. Moreover, under UV light, it can be completely removed at low concentration within 6 min. The micropores in ACF and nanocages in ZIF-8 are suitable for small molecular HCHO uptaking and provide sufficient contact time for photocatalysis by TiO 2 . The ALD technology provides a useful methodology for the practical application of MOF-based materials.
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CHEMOSPHERE
·
2022
·
IF 8.943
Mengya Li,Lei Li,Yue Sun,Hengyan Ma,Hui Zhang,Feng Li
Multi-pesticides pollution induced by organophosphorus insecticides (OPs) and aryloxyphenoxypropionate herbicides (AOPPs) has become a significant challenge in bioremediation of water pollution due to their prolonged and over application. Though a number of physical, chemical, and biological approaches have been developed for different pesticides, the explorations usually focus on eliminating single pesticide pollution. Herein, a heterostructure nanocomposite OPH/QpeH@mZIF-8, encapsulating OPs hydrolase OPH and AOPPs hydrolase QpeH in the magnetic zeolitic imidazolate frameworks-8 (mZIF-8), was synthesized through a facile one-pot method in aqueous solution. The immobilized OPH and QpeH in mZIF-8 showed high activities towards the two most common OPs and AOPPs, i.e., chlorpyrifos and quizalofop- P -ethyl, which were hydrolyzed to 3,5,6-Trichloro-2-pyridino (TCP) and quizalofop acid, respectively. Moreover, the magnetic nanocatalyst possessed great tolerance towards broad pH range, high temperatures, and different chemical solvents and excellent recyclability . More importantly, compared to free OPH and QpeH, OPH/QpeH@mZIF-8, with significantly enhanced degradation capability, exhibited enormous potential for simultaneous removal of chlorpyrifos and quizalofop-p-ethyl from the surface and industrial wastewater . Overall, the study demonstrates the applicability of this strategy for utilizing magnetic nanocatalysts encapsulating multiple enzymes due to its simplicity, high efficiency, and economic benefits to removing pesticide compound pollution from various water resources.
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CHEMICO-BIOLOGICAL INTERACTIONS
·
2022
·
IF 5.168
Moath Refat,Guoqiang Zhang,Abdulaziz Ahmed A.Saad,Salem Baldi,Fang Zheng,Xin'an Wu
Cholestasis is primarily caused by bile acid homeostasis dysregulation, resulting in retention, aggregation, and accumulation of the toxic cholate in the hepatocytes. Existing therapies for cholestasis are limited, demanding the urgent development of novel drugs. As a result, targeting FXR specifically promises a unique treatment strategy for cholestasis. The current study aims to evaluate the influence of 7, 8-dihydroxy-4-methyl coumarin (DMC) against alpha-naphthyl isothiocyanate (ANIT)-induced liver injury in mice. The “Computer-Aided Drug Design” (CADD) and molecular docking study anticipated that DMC would proficiently bind and activate the FXR. Accordingly, the hepatoprotective activity of DMC against ANIT-induced hepatotoxicity and cholestasis was investigated in ANIT-treated HepaRG cells and the ANIT-induced cholestatic mouse model. Outcomes indicated the protective effects of DMC against ANIT toxicity in HepaRG cells after 24 h of intervention and animals after seven days of treatment. DMC partially blocks ANIT-induced increases in serum markers of hepatocellular injury , liver and gall bladder enlargement , and hepatic necrosis . Western blotting revealed that DMC alleviates ANIT-induced hepatotoxicity and cholestasis via activating the FXR receptor and regulating CYP7A1 , the enzyme responsible for bile acid synthesis. DMC exhibited protective activity against cholestasis through activating FXR, suggesting it might be a promising strategy for preventing and treating cholestatic liver disease.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Yaqi Zhang,Linli Tan,Na Han,Shiwei Tian,Wei Li,Wei Wang,Yutong Wu,Zhongshun Sun,Xingxiang Zhang
The separation of oil-in-water and water-in-oil emulsions with high efficiency and environmental friendly remains a challenge in the past decade. This work describes a new method to improve the trade-off of the poly(acrylonitrile- co -methyl acrylate) (P(AN-MA))-based membrane for water/oil separation. P(AN-MA) microfiltration (MF) membrane was fabricated via thermally induced phase separation (TIPS) method in this study. Then, some of the –CN groups and –COOCH 3 groups were converted to –COOH groups via hydrolyzing. Finally, the selected wettability was attained by grafting PEI on one side while ZIF-8 was anchored to the other side via self-assembly and in-situ interfacial reaction methods. The ZIF-8/P(AN-MA) hybrid MF membranes are superoleophobic underwater on the PEI side while super-hydrophobic under oil on the ZIF-8 side, which can efficiently and accurately separate oil-in-water and water-in-oil emulsions at a low pressure (0.01 MPa). The separation fluxes of the PEI side were as high as 3053 L/m 2 h and 1035 L/m 2 h respectively, for the surfactant-free mixtures and surfactant-stabilized emulsions. For water-in-oil emulsions, the fluxes were up to 2316 L/m 2 and 878 L/m 2 h on the ZIF-8 side, respectively. The separation efficiency of all the mixtures and emulsions was higher than 97.5 %. Moreover, the Janus membranes showed excellent anti-oil-fouling and anti-water-fouling properties on the two sides of the membranes, as well as remarkable durability during the 10 cycles in oil/water separation. Hence, Janus ZIF-8/P(AN-MA) hybrid MF membranes show potential application prospects in oil/water separation.
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