FIBERS AND POLYMERS
·
2020
·Vol. 21
·期 1
·119-126
·
IF 1.797
Xu Wenlong,Yang Xue,Xin Binjie
Polyacrylonitrile (PAN)/cellulose nanofibril (CNF) nanofiber membranes were successfully prepared by an electrospinning method, in which the amount of CNF kept 1 wt%. The effects of CNF sizes on the morphology and properly of spinning solutions and PAN electrospun nanofiber membrane were systematically investigated by rheological property test, conductivity test, SEM, TG, DSC, contact angle test and mechanical test. The results showed that the viscosity and conductivity of the spinning solution was improved with the increasing of CNF sizes, as the formation of the strong polar interactions of nitrile groups and the hydroxyl groups between PAN and CNF. All the morphology of the PAN/CNF nanofiber membrane exhibited a uniform diameter with no visible beads or beads to the string structure, and the average diameter of the PAN/CNF nanofiber was decreased with the increasing of the CNF size. Moreover, the addition of CNF could improve the thermal stability, mechanical properly, and hydrophilicity of the PAN membrane. And the PAN/CNF-10 nanofiber membrane exhibited the optimal properties.
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高影响因子
Chinese Medicine
·
2020
·Vol. 15
·期 1
·1-15
·
IF 2.96
Mohammadtursun Nabijan,Li Qiuping,Abuduwaki Muhammadjan,Jiang Shan,Zhang Hu,Sun Jing,Dong Jingcheng
Background Loki zupa formula is kind of a traditional medicines which used to treat airway diseases, especially those caused by abnormal phlegm, such as cough, asthma and chronic bronchitis. The study aim was to explore the anti-inflammatory and anti-remodeling effects of Loki zupa by using a cigarette-smoke induced rat model of chronic obstructive pulmonary disease.Methods The rats were divided into five groups: the normal group, the model group, the LZ 4 g/kg and LZ8g/kg group, and the positive control group. Rats were exposed to cigarette smoke for 24 weeks to induce a COPD rat model. Lung function was assessed. Histopathological changes were recorded using Haematoxylin–eosin and Masson’s trichrome staining. Mucus hypersecretion was evaluated by PAS staining. Inflammatory factors were measured in blood serum and bronchial alveolar lavage fluid using an enzyme-linked immunosorbent assay. Malondialdehyde and superoxide dismutase and glutathione S-transferase levels were tested by biochemical methods. Gene expression patterns were evaluated using GN-GeneChip Clariom S Array for rat from Affymetrix. And top upregulated and downregulated genes validated by qPCR. And these genes was also compared with gene transcriptomic data from smoker patients with emphysema and non-smokers in GEO dataset. IL-6/PLAGA2A signalling protein expression was assessed by western blot and immunohistochemistry. TGF-β1and smad2/3 signalling expressions were analysed by western Blot.Results Loki zupa improved COPD rats lung function as compared to the model group and pathological changes including inflammatory cell infiltration and goblet cell metaplasia was alleviated in rats treated with Loki zupa Inflammatory factors IL-6, TNF-α, IL-1β and TGF-β1 decreased while significant increase was observed in blood serum IL-10 content in rats treated with Loki zupa. And IL-6 and TNF-α level in bronchial alveolar lavage fluid showed same expression trend in blood serum, while there was no change in MMP-9 content. It also increased antioxidant enzyme SOD and GPX activity while reducing the lipid peroxidation. Gene microarray analysis showed that there were 355 differentially expressed gene in LZ treated COPD rat lung as compared to model group. Both microarray and qPCR results showed that top differentially expressed genes nxt1 (up regulated) and pla2g2a (down regulated) expression were also reversed by LZ treatment. And protein expression level of IL-6 and pla2g2a was also elevated in CS exposed rats while significant reduction was observed in LZ treated rats. Accordingly, Loki zupa inhibited Collagen-1 upstream protein expression of TGF-β/smad2/3 signalling pathway.Conclusion These results demonstrated that Loki zupa showed protective effects in the lung of the COPD rat model. This mainly because of Loki zupa exerts anti-inflammatory effects by blocking IL-6/pla2g2a signalling and inhibiting inflammatory gene expression and attenuates fibrotic responses by inhibiting TGF-β/smad2/3 signalling pathway.
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高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2020
·Vol. 130
·期 2
·1027-1042
·
IF 1.52
Shi Qiqi,Guo Heqin,Chen Congbiao,Hou Bo,Jia Litao,Li Debao
In the present work, a series of sulfonic polymer-based acid catalyst PDS-x’s was obtained by hydrothermal method. The physical and chemical properties of the catalysts were characterized by X-ray diffraction, N 2 adsorption–desorption isotherms, thermogravimetric analysis, Fourier transform infrared spectrometer, pyridine-adsorbing IR, acid–base titration, X-ray photoelectron spectroscopy, and CHNS elemental analysis. The carbonylation of formaldehyde was chosen as a probe reaction to test the catalytic performance. The results show that the content of acid sites and specific surface area can be adjusted by changing the molar ratio of sodium 4-vinylbenzenesulfonate (SVBS) to divinylbenzene (DVB). The catalyst performance results show that the PDS-x’s can efficiently catalyze glycolic acid synthesis. And a high glycolic acid yield up to 96% was obtained on PDS-2.1 due to its large specific surface area, plentiful mesoporosity as well as suitable acid concentration. This data are even higher than those on super-strong CF 3 SO 3 H and commercial resin Amberlyst-15. Moreover, the carbonylation of formaldehyde is a structure-sensitive reaction, the isolated and monolayer dispersed -SO 3 H is much more active than aggregated −SO 3 H. Furthermore, the catalyst has high stability.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 15
·12830-12841
·
IF 2.22
Li Xiang,Zhu Yao-Feng,Meng Fan-Bin,Ni Qing-Qing
Micro-nano structure regulation of polyaniline and impedance-matching design of its composites are two crucial but challenging works in microwave absorption. In this study, an in situ sacrificial templates polymerization is applied to regulate the porous structures of polyaniline decorated on vapor-grown carbon fiber (VGCF). By manipulating porous polyaniline structures, heterogeneous interfaces, polarization centers, and geometric structures are introduced into porous VGCF@polyaniline nanohybrids. Porous VGCF@polyaniline demonstrated robust microwave absorption ability with a minimum reflection loss of − 55.9 dB at 10.3 GHz with a filler loading of 18 wt% and a thinner thickness of 1.33 mm. The investigation of the novel porous polyaniline structures and composition relationship suggest that the microwave absorption ability of porous VGCF@polyaniline is originated from the optimal impedance-matching ratio, enhanced dielectric loss, and synergistic effect, which is enhanced by conductive loss and interfacial polarization. A universal approach was proposed to address the critical issue of hybridizing porous VGCF@polyaniline with flexible polyurethane sponge as practical electromagnetic absorption structures. The hybrids exhibited interesting dual absorption properties with minimum reflection loss of − 28.8 and − 35.5 dB at frequencies of 8.5 and 8.7 GHz, respectively. This study provides a new approach for designing lightweight and practical microwave absorbers.
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Tungsten
·
2020
·Vol. 2
·期 2
·194-202
·
IF 0
Yu Xue-Ping,Yang Chan,Song Pin,Peng Juan
Ultra-small MoS 2 quantum dots (QDs) with an average size of 2.48 nm coated on Au nanoparticles with a core-satellite structure (Au/MoS 2 QDs) are successfully prepared by a self-assembly strategy through the strong bonding between Au and S. Benefited from the unique structure, the Au/MoS 2 QDs hybrid exhibits outstanding electrocatalytic performance toward hydrogen evolution reaction (HER). The Au/MoS 2 QDs hybrid needs overpotentials of 112, 146, and 206 mV to approach current densities of 10, 20, and 50 mA·cm −2 in 0.5 mol·L −1 H 2 SO 4 (pH = 0.3), respectively. And a low Tafel slope (83 mV·dec −1 ) is obtained. The catalyst also displays satisfactory stability and durability, indicating a negligible current density loss after 20 h of electrolysis. The high hydrogen generation activities and stability are attributed to the great number of active sites, high conductivity and synergistic effects between gold nanoparticles (Au NPs) and MoS 2 QDs. Last but not least, this strategy opens up a favorable way to combine MoS 2 QDs with other metals.
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Chinese Medicine
·
2020
·Vol. 15
·期 1
·1-18
·
IF 2.96
Qin Zifei,Jia Mengmeng,Yang Jing,Xing Han,Yin Zhao,Yao Zhihong,Zhang Xiaojian,Yao Xinsheng
Background Kang-Ai injection is widely used as an adjuvant therapy drug for many cancers, leukopenia, and chronic hepatitis B. Circulating alkaloids and saponins are believed to be responsible for therapeutic effects. However, their pharmacokinetics (PK) and excretion in vivo and the risk of drug–drug interactions (DDI) through inhibiting human cytochrome P450 (CYP) and UDP-glucuronosyltransferase (UGT) enzymes remain unclear.Methods PK and excretion of circulating compounds were investigated in rats using a validated ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC–MS) method. Further, the inhibitory effects of nine major compounds against eleven CYP and UGT isozymes were assayed using well-accepted specific substrate for each enzyme.Results After dosing, 9 alkaloids were found with Cmax and t1/2 values of 0.17–422.70 μmol/L and 1.78–4.33 h, respectively. Additionally, 28 saponins exhibited considerable systemic exposure with t1/2 values of 0.63–7.22 h, whereas other trace saponins could be negligible or undetected. Besides, over 90% of alkaloids were excreted through hepatobiliary and renal excretion. Likewise, astragalosides and protopanaxatriol (PPT) type ginsenosides also involved in hepatobiliary and/or renal excretion. Protopanaxadiol (PPD) type ginsenosides were mainly excreted to urine. Furthermore, PPD-type ginsenosides were extensively bound (fu-plasma approximately 1%), whereas astragalosides and PPT-type ginsenosides displayed fu-plasma values of 12.35% and 60.23–87.36%, respectively. Moreover, matrine, oxymatrine, astragaloside IV, ginsenoside Rg1, ginsenoside Re, ginsenoside Rd, ginsenoside Rc, and ginsenoside Rb1 exhibited no inhibition or weak inhibition against several common CYP and UGT enzymes IC50 values between 8.81 and 92.21 μM. Through kinetic modeling, their inhibition mechanisms towards those CYP and UGT isozymes were explored with obtained Ki values. In vitro-in vivo extrapolation showed the inhibition of systemic clearance for CYP or UGT substrates seemed impossible due to [I]/Ki no more than 0.1.Conclusion sWe summarized the PK behaviors, excretion characteristics and protein binding rates of circulating alkaloids, astragalosides and ginsenosides after intravenous Kang-Ai injection. Furthermore, weak inhibition or no inhibition towards these CYP and UGT activities could not trigger harmful DDI when Kang-Ai injection is co-administered with clinical drugs primarily cleared by these CYP or UGT isozymes.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 15
·6669-6677
·
IF 3.553
Li Wan
Hydrogels as drug carriers for delivery of antibiotics are rarely derived from natural molecules and often require complicated synthesis. Puerarin is an herbal natural product that can self-assemble to form pH-sensitive hydrogels without any structural modification. However, Puerarin hydrogels have poor thermostability and weak mechanical strength. In this work, we prepared N -(9-fluorenylmethoxycarbonyl)- l -phenylalanine (Fmoc–Phe–OH) nanofiber-reinforced Puerarin hydrogels with good mechanical and antibacterial properties for suitable drug carriers. The phase transition temperature of Puerarin hydrogels can be increased from 35 to 55 °C by adding only 6 mg/mL of Fmoc–Phe–OH. Rheological study indicated that the presence of Fmoc–Phe–OH not only increased the storage modulus of Puerarin hydrogels by five times, but also did not affect their pH sensitivity. SEM study and pore analysis indicated that Fmoc–Phe–OH nanofibers intertwined with the Puerarin assembly, leading to enhancement of mechanical property of hydrogel. Antibacterial test indicated that the reinforced Puerarin hydrogels have antibacterial property compared with Puerarin hydrogels. Based on these features, a controllable release of loaded model drug (berberine hydrochloride) can be realized from the reinforced Puerarin hydrogels, showing a good synergistic antimicrobial effect on the S. aureus .
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2020
·Vol. 94
·期 2
·416-424
·
IF 2.008
Tian Wei,Du Bin,Shui Anze,Ke Shanjun,Shan Qingliang,He Chao,Ma Juan
In this work, a silica-based mesoporous oxide (SMO) was directly fabricated via a template-free method using the abundant and inexpensive volcanic ash as raw material. By alkali hydrothermal activation and acid hydrothermal etching of volcanic ash, the SMO with large mesopore size (7.94 nm), high specific surface area (459.5 m 2 /g), and total pore volume of 1.05 cm 3 /g was produced. The main ingredient of SMO is amorphous microporous silica. The structural evolutions of the mesoporous materials were revealed by X-ray powder diffraction, scanning electron microscope, Fourier transform infrared spectrometry, N 2 adsorption/desorption, and transmission electron microscopy techniques. The as-prepared SMO possessed excellent adsorption of water vapor as high as 616.0 g/m 2 at the relative humidity ranging from 33 to 75%. This SMO provides a platform for preparing high performance template-freely humidity self-regulating material.
This figure shows that silica-based mesoporous oxide (SMO) quickly adsorbs moisture at RH = 75% and reaches to 616.0 g/m 2 , and then the adsorbed water releases at 33% RH. These results suggest SMO have an excellent humidity self-regulating function in the RH ranging from 33 to 75%.
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SN Applied Sciences
·
2020
·Vol. 2
·期 3
·1-10
·
IF 0
Guo Liulong,Yan Hongxia,Chen Zhengyan,Lv Qing,Bai Tian,Zhang Yuanbo
A novel hyperbranched polysiloxane functionalized graphene oxide (HPBSi-GO) containing abundant primary amine, tertiary amine and hydroxyl groups was designed and successfully synthesized though efficient “grafting to” method. The as-synthesized HBPSi-GO was confirmed by FT-IR, XPS and AFM. Moreover, the HPBSi-GO was incorporated into epoxy (EP) resin matrix to fabricate HPBSi-GO/EP composites. The results showed that the HPBSi-GO has better dispersibility than that of unmodified GO in EP matrix. Interestingly, the mechanical and frictional properties of HPBSi-GO/EP composites were simultaneously superior to those of neat epoxy resin. AFM and TOM results revealed that the good properties mainly attributed to the unique inorganic–organic structure of HBPSi-GO, as well as the good interfacial adhesion between HBPSi-GO and EP matrix.
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CATALYSIS LETTERS
·
2020
·Vol. 150
·期 7
·1890-1897
·
IF 2.482
Zhou Na,Yan Ruiyao,Pan Yanlin,Fang Xue-Qian
The fast recombination of photogenerated electrons and holes in the pure TiO 2 leads to a low photocatalytic efficiency in hydrogen generation or solar energy conversion. Noble metal nanoparticles have been used to combine with TiO 2 for effective photocatalysis. Herein, Au@Ag@TiO 2 nanorods (NRs) with core–shell structure have been prepared by hydrolysis the precursor of titanium in acid environment. UV light–driven H 2 generation rate of Au@Ag@TiO 2 samples demonstrated 14 times enhancement compared to P25 TiO 2 at the same experimental conditions. The improved photocatalytic performance was due to the charge transfer from the conduction band of excited TiO 2 to Au@Ag NRs leading to effective separation of electron–hole pairs. This mechanism has been proved by transient absorption spectroscopy and photo-electrochemical (PEC) measurements. The time resolved photocurrents of P25 TiO 2 NPs is ~ 13 times higher that of Au@Ag@TiO 2 , indicating that a fraction of the photogenerated electrons of TiO 2 driven by UV light transfer to Au@Ag nanocores instead of transporting entirely to the ITO substrates. The ultrafast transient absorption and pump-probe measurements demonstrated a faster decay in Au@Ag@TiO 2 NRs compared to pure TiO 2 system, indicating that the photogenerated electron–hole recombination in TiO 2 is substantially suppressed by Au@Ag@TiO 2 NRs attributed to the effective trapping of the photogenerated electrons by the Au@Ag cores. Graphic Abstract Au@Ag@TiO 2 nanocomposites with core-shell structure have been prepared and its UV light–driven H 2 generation rate has been demonstrated 14 times enhancement compared to P25 TiO 2 at the same experimental conditions. The improved photocatalytic performance was due to the charge transfer, which has been proved by photocurrent measurement and the ultrafast transient absorption and pump-probe measurements.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 19
·8403-8419
·
IF 3.553
Zhang Yuhui,Lin Ligang,Wang Qi,Qiang Rongrong,Gao Yixin,Ma Sisi,Cheng Qi,Zhang Yuzhong
A new strategy was proposed that simultaneously improves the pervaporation (PV) performance and solvent resistance via the construction of a movable crosslinked structure in ethyl cellulose/polyvinylidene fluoride (EC/PVDF) composite membrane for the purpose of benzene/cyclohexane separation. Based on the molecular design of the macrocyclic compound cyclodextrin, polyrotaxane crosslinking agent (PR=) with a special sliding/rotating property and cavity structure was successfully synthesized. Furthermore, for convenient comparative study, cyclodextrin crosslinking agent (CD=) with cavity structure bereft of a sliding/rotating property and pentaerythritol triacrylate (PETA) without sliding/rotating property and cavity structure were prepared. The composite membranes were fabricated with crosslinking modified EC as active layer, together with PVDF support layer. The molecular structure and microstructure were confirmed. The pervaporation and swelling performance of the fabricated membranes for benzene/cyclohexane were investigated. PR= modified membranes showed good solvent resistance and exhibited a flux of 4332 g·m −2 ·h −1 and separation factor of 6.26, which was higher than CD= and PETA modified membranes. The results were attributed to the facilitated transport behavior, which was markedly related with the sliding/rotating property and cavity structure of polyrotaxane (PR). The related research provides interesting suggestions for PV membrane design for the separation of organic mixtures.
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 9
·2703-2708
·
IF 2.482
Zhao Zhaohui,Wang Yanhua
Abstract Thermoregulated phase-transfer Pd nanocatalyst was firstly employed in the selective hydrogenation of 1,5-cyclooctadiene (1,5-COD) at atmospheric hydrogen pressure. Under the optimal conditions, > 99% conversion and 95% selectivity to cyclooctene (COE) were obtained. The Pd nanocatalyst can be easily separated from products and directly reused. The turnover frequency (TOF) of 1411 h −1 is the highest value ever reported among Pd nanocatalysts at atmospheric hydrogen pressure. Graphic Abstract
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