INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2015
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IF 2.587
Jinxia Zhou,Tingyu Huang,Yuling Zhao,Zhi Xia,Zhanwei Xu,Songyan Jia,Jianji Wang,Z. Conrad Zhang
Ionic liquids have been widely studied as effective reaction media for the conversion of glucose or cellulose to 5-hydroxymethhylfurfural (5-HMF). However, the recovery of 5-HMF from ionic liquids, typically carried out by extraction, has been encountered with very low extraction efficiency, which limited the reusability of the solvents. Through this work, based on the model biphasic system that consists of 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) as the ionic liquid phase and methyl isobutyl ketone (MIBK) as the extractant phase, the dominant force that suppresses the extraction efficiency of 5-HMF was identified as being the strong hydrogen bonding between 5-HMF and [BMIM]Cl. Solvent mediation with functional promoters have been established as a new strategy to shift this force, resulting in improved extraction efficiency of 5-HMF from the ionic liquid. For example, with ethanol as a promoter, the distribution coefficient of 5-HMF was about 10 times higher than that without a promoter.
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BIORESOURCE TECHNOLOGY
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2015
·
IF 4.494
Jingyun Wang,Mingdong Zhou,Yuguo Yuan,Quan Zhang,Xiangchen Fang,Shuliang Zang
Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5 mol% of tetramethyl ammonium perrhenate as catalyst, 70 μL of water, ca. 0.6 mmol of microcrystalline cellulose (MCC) and 2.0 g of [Amim]Cl as solvent under microwave irradiation for 30 min at 150 °C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO 4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose.
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APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Yichuan Li,Xinyan Zhang,Mingxing Luan,Yuntong Zhao,Shibin Feng,Zhaosheng Yang,Bin Liu,Yongming Chai
Molecular sieve membranes are widely used in separation and catalysis due to their good chemical and thermal stability, resistance to contamination, long life, and easy modification. Although immobilized molecular sieve membranes combine catalytic reactivity with recycling separation properties, preparing high-performance TS-1 molecular sieve membrane catalysts is still challenging. In this study, the oriented aggregation of nanocrystals was used in constructing molecular sieve membrane catalysts. By interfering with the crystallization of TS-1, pre-crystal modification with cetyltrimethoxysilane was employed to change the crystal growth behavior. Thus, uniform and dense molecular sieve membranes were prepared through the modulated crystallization of TS-1. This method reduced the requirements of the carrier surface properties for the loading of the membrane layer to enable the construction of membrane layers on carriers of different materials and shapes. Using this method, the effective H 2 O 2 utilization and the epichlorohydrin yield of the micron-sized spherical film catalyst prepared with the inexpensive templating agent TPABr in the chloropropene epoxidation reaction reached 95.89% and 90.22%, respectively.
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PHYTOMEDICINE
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2016
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IF 2.937
Ramachandran Vinayagam,Baojun Xu
Background and objective Daphnetin (7, 8-dihydroxycoumarin), a natural coumarin compound, is known to exhibit antioxidant and anti-inflammatrory effects. However, the underlying mechanisms of its anti-apoptotic and antidiabetic effects yet not been examined. Therefore, the present work studied the anti-apoptotic and anti-diabetic effects of daphnetin by in vitro experiments. Methods The rat insulinoma (INS-1) cells were pre-treated with daphnetin at different concentrations (1, 10, 20 and 40 µM) for 24 h followed by exposition to streptozotocin (STZ) (3 mM) for 12 h. Effects of daphnetin and STZ on INS-1 cells were determined by MTT assay, glucose stimulated insulin secretion (GSIS) assay, lipid peroxidation, antioxidant status (SOD, CAT, GPx, and GST) Apoptosis staining (DAPI, Hoechst 33342, AO/EB and ROS) was performed by fluorescence microscopy, and Bcl-2, Bax and NF-κB protein expression was detected by Western blotting. Results MTT assay indicated that the viability of INS-1 cells was significantly reduced with exposure to STZ for 12 h as compared to control cells, while pre-treated with daphnetin for 24 h resulted in a significant improvement of cell viability. The effects daphnetin treatment in INS-1 cells on insulin secretion was tested and results showed that the pre-treatment of daphnetin could improve GSIS. Further, daphnetin pre-treatment significantly reduced the levels of lipid peroxidation markers and also improved antioxidant enzymes’ activities in STZ-induced INS-1 cells. Western blotting assay revealed that daphnetin could suppress apoptosis through up-regulation of anti-apoptotic Bcl-2 protein expression and the down-regulation of pro-apoptotic Bax and nuclear factor NF-κB protein levels. Conclusion The results showed that daphnetin might be used in treating diabetes due to its insulin stimulating property and subsequent regulation of apoptotic pathway.
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Nanoscale Research Letters
·
2016
·Vol. 11
·期 1
·1-8
·
IF 2.584
Zheng Dan,Guo Peng,Xiong Juan,Wang Shengfu
A ZnO-based film bulk acoustic resonator has been fabricated using a magnetron sputtering technology, which was employed as a biosensor for detection of mucin 1. The resonant frequency of the thin-film bulk acoustic resonator was located near at 1503.3 MHz. The average electromechanical coupling factor \( {K}_{\mathrm{eff}}^2 \) and quality factor Q were 2.39 % and 224, respectively. Using the specific binding system of avidin-biotin, the streptavidin was self-assembled on the top gold electrode as the sensitive layer to indirectly test the MUC1 molecules. The resonant frequency of the biosensor decreases in response to the mass loading in range of 20–500 nM. The sensor modified with the streptavidin exhibits a high sensitivity of 4642.6 Hz/nM and a good selectivity.
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Catalysis Science & Technology
·
2017
·Vol. 7
·期 4
·982-987
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IF 5.773
Zongwei Mei,Mingjian Zhang,Julian Schneider,Wei Wang,Ning Zhang,Yantao Su,Bingkun Chen,Shufeng Wang,Andrey L. Rogach,Feng Pan
A series of hexagonal Zn1−xCdxS photocatalysts with variable composition (0.2 ≤ x ≤ 1) is synthesized by a solvothermal method. XPS spectra of Zn 2p and Cd 3d regularly shift upon changing the composition of Zn1−xCdxS samples, due to the difference in the Mulliken atomic charges of Zn, Cd, and S. The photocatalytic activity of the samples for H2 evolution from water was tested under visible-light irradiation (λ ≥ 420 nm) without a cocatalyst; the Zn0.4Cd0.6S sample exhibited the highest photocatalytic H2 evolution rate, which was about 81 mL h−1 g−1. Under irradiation with a 368 nm LED, the H2 evolution rate decreased with increasing Cd fraction in the Zn1−xCdxS solid solution. By comparing the crystallinity, surface area, valence/conduction band positions, absorption spectra and fluorescence lifetimes, we conclude that the photocatalytic activity is related to the balance between the absolute positions of the valence/conduction bands and light absorption ability of the Zn1−xCdxS photocatalysts.
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JOURNAL OF MEMBRANE SCIENCE
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2016
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IF 5.557
Dong Guo,Yi Zhi Zhuo,Ao Nan Lai,Qiu Gen Zhang,Ai Mei Zhu,Qing Lin Liu
There is a balance between ionic conductivity and dimensional stability in anion exchange membranes (AEMs). High conductivity resulting from densely charged groups is normally accompanied with high water uptake and excessive swelling. Herein, a series of novel AEMs with interpenetrating network was prepared by the incorporation of poly(vinylbenzyl chloride) (PVBC) and poly(1-vinylimidazole)(PVIm) into the PVA matrix. PVBC and PVIm act as bifunctional macromolecular crosslinking agents to provide both imidazolium cations and to form crosslinked network in the membranes. The resulting AEMs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The effect of crosslinking density on conductivity, water uptake, swelling ratio and stability was investigated. The results reveal that the addition of PVBC-c-PVIm could be simultaneously conducive to higher conductivity and lower swelling ratio. Notably, the membrane containing 50 wt% PVBC-c-PVIm had IEC of 1.86 meq g −1 , water uptake of 39.4%, and hydroxide conductivity of 21.9 mS cm −1 at 30 °C. A maximum power density of 37.1 mW cm −2 is achieved at a current density of 64 mA cm −2 . The crosslinked AEMs also exhibit excellent alkaline stability in a 4 M KOH solution at 60 °C for 1320 h.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2016
·
IF 8.328
Xuyang Xiong,Liyong Ding,Qingqian Wang,Yongxiu Li,Qingqing Jiang,Juncheng Hu
A series of BiOBr nanosheets with tunable exposing proportion of (0 1 0) facets had been synthesized. In the synthesis process, different n -alcohols are used, which not only promote the exposure of (0 1 0) facets, but also modulate the size and thickness of these BiOBr nanosheets in a wide range. Furthermore, these nanosheets showed an efficient photodegradation activity for salicylic acid (SA) and Rhodamine B (RhB). By comparison, the sample prepared in n -hexanol possessed the highest photocatalytic activity than those synthesized in n -butanol and methanol, respectively. This excellent photocatalytic activity was attributed to the thin lamellar thickness and the exposure of (0 1 0) facets, which facilitated the separation of photoinduced electrons and holes.
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COLLOIDS AND SURFACES B-BIOINTERFACES
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2016
·
IF 3.902
Lin Li,Xingsheng Di,Shenwu Zhang,Qiming Kan,Hao Liu,Tianshu Lu,Yongjun Wang,Qiang Fu,Jin Sun,Zhonggui He
The therapeutic outcome of glioma treatment is rigorously limited by blood–brain barrier (BBB) and infiltrating growth of glioma. To tackle the dilemma, more and more attentions were focused on developing nutrient transporters-mediated dual-targeted drug delivery system, in one side for BBB penetration, another for intracranial glioma targeting. Herein, Large amino acid transporter 1 (LAT1), overexpressed both on BBB and glioma cells, was selected as a target. Docetaxel-loaded glutamate- d -α-tocopherol polyethylene glycol 1000 succinate copolymer (Glu-TPGS) functionalized LAT1-targeting liposomes (DTX-TGL) were applied to enhance the BBB penetration and glioma therapy. The in vivo results of the fluorescent image indicated that TGL possessed an effective BBB penetration than that of unmodified ones in mice. The LAT1 targeting effcicacy and cell cytotoxicity of TGL were investigated in C6 glioma cells. Compared with unmodified liposomes, a significant higher cellular uptake and cell cytotoxicity was found in TGL treated group. Our results indicated that LAT1-targeting docetaxel-loaded liposome paves up a new direction using LAT1 transporter as a good target in designing brain glioma-targeting nanosystems.
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FOOD SCIENCE AND BIOTECHNOLOGY
·
2016
·Vol. 25
·期 4
·1115-1122
·
IF 0.699
Feng Yanli,Chen Wanping,Chen Fusheng
Monacolin K (MK) produced by Monascus spp. is mostly used to regulate cholesterol level, while it can be contaminated by citrinin, a mycotoxin yielded by some Monascus strains. To develop production of citrinin-free MK, an M . sp. MS-1 strain, identified as M. pilosus by morphologies and internal transcribed spacer sequences analysis, was isolated from red fermented rice. After 14 days of fermentation, yields of citrinin-free MK could be up to 0.58 mg/mL and 16.45 mg/g in liquid- and solidstate fermentation products under optimal conditions, respectively. Further determination revealed that no citrinin biosynthesis related genes such as ctnA , pksCT , ctnE , and ctnR were detected. Thus, HPLC combined with citrinin-related gene analyses can be used for rapid screening of non-citrinin production Monascus strains.
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Cell Death & Disease
·
2017
·Vol. 8
·期 2
·e2609
·
IF 5.965
Yang Mengliu,Wang Jinzhi,Wu Shaobo,Yuan Lei,Zhao Xiaodong,Liu Chaohong,Xie Jing,Jia Yanjun,Lai Yerui,Zhao Allan Zijian,Boden Guenther,Li Ling,Yang Gangyi
Intestinal glucagon-like peptide-1 (GLP-1) is a hormone that stimulates insulin secretion and acts as a neuropeptide to control glucose homeostasis, but little is known whether intestinal GLP-1 has any effect in the control of hepatic glucose production (HGP). Here we found that intraduodenal infusion of GLP-1 activated duodenal PKC- δ , lowered HGP and was accompanied by a decrease in hepatic expression of gluconeogenic enzymes and an increase in hepatic insulin signaling in rats. However, gut co-infusion of either the GLP-1 receptor antagonist Ex-9, or the PKC- δ inhibitor rottlerin with GLP-1, negated the ability of gut GLP-1 to lower HGP and to increase hepatic insulin signaling during clamps. The metabolic and molecular signal effects of duodenal GLP-1 were also negated by co-infusion with tetracaine, pharmacologic inhibition of N -methyl- d -aspartate receptors within the dorsalvagal complex, or hepatic vagotomy in rats. In summary, we identified a neural glucoregulatory function of gut GLP-1 signaling.
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PHARMACOLOGY
·
2014
·
IF 1.581
Ping Mao,Xiao Wei,Mo Liqian,Xiao Xiaoyan,Song Shaolian,Tang Waijiao,Yang Xixiao
Background: Paeonol (2'-hydroxy-4'-methoxyacetophenone) is thought to possess a broad range of clinically curative effects that are likely mediated by its anti-inflammatory and antioxidant activities. Aims: To elucidate the efficacy of paeonol's anti-inflammatory and antioxidant activities and the underlying mechanism of paeonol in advanced oxidation protein product (AOPP) stimulation of THP-1 macrophages. Materials and Methods: After incubating cells with AOPP plus paeonol, nitric oxide (NO) production and the levels of inducible NO synthase (iNOS), receptor for advanced glycation end products (RAGE), CD36, scavenger receptor (SR)-A, and SR-B1 were calculated. Moreover, THP-1 macrophages were preincubated with paeonol, the free radical scavenger N-acetylcysteine (NAC), NADPH oxidase inhibitors [apocynin, diphenylene iodonium (DPI)], and the specific inhibitor of nuclear factor-κB pyrrolidine dithiocarbamate (PDTC) prior to incubation with AOPP, and the levels of intracellular reactive oxygen species (ROS) production and tumor necrosis factor-a (TNF-a), interleukin (IL)-1ß, IL-6, and monocyte chemotactic protein 1 (MCP-1) were determined. Results: Paeonol increased NO production and the mRNA level of iNOS, whereas it decreased ROS production. ROS production was also effectively attenuated by apocynin, DPI, NAC, and PDTC. Furthermore, these inhibitors and paeonol could downregulate the mRNA and protein levels of proinflammatory cytokines (TNF-a, IL-1ß, IL-6, and MCP-1). Paeonol significantly reduced the expression levels of RAGE and CD36 but increased the expression levels of SR-A and SR-B1. Conclusions: These results indicate that paeonol can decrease proinflammatory cytokines in THP-1 macrophages, likely through RAGE-, CD36-, SR-A-, and SR-B1-mediated signals involving NADPH oxidase-dependent ROS generation. This suggests that paeonol can be used as a therapeutic agent for diseases contributing to oxidative stress injury
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