Crystals
·
2022
·Vol. 12
·期 2
·210
·
IF 2.67
Xingyuan Diao,Xiaonan Chen,Shihao Deng,Hongwei Bai
Stereocomplex-type polylactide (SC-PLA) created by alternate packing of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) chains in a crystalline state has emerged as a growingly popular engineering bioplastic that possesses excellent hydrolytic stability and thermomechanical properties. However, it is extremely difficult to acquire high-performance SC-PLA products via melt-processing of high-molecular-weight PLLA/PDLA blends because both SC crystallites and homocrystallites (HCs) are competitively formed in the melt-crystallization. Herein, a facile yet powerful way was employed to boost SC formation by introducing trace amounts of some epoxy-functionalized small-molecule modifiers into the enantiomeric blends during reactive melt-blending. The results show that the SC formation is considerably enhanced with the in situ generation of multi-arm stereo-block PLA copolymers, based on the reaction between epoxy groups of the modifiers and hydroxyl end groups of PLAs. More impressively, it is intriguing to find that the introduction of only 0.5 wt% modifiers can induce exclusive SC formation in the blends upon isothermal and non-isothermal melt-crystallizations. The outstanding SC crystallizability might be attributed to the suppressing effect of such unique copolymers on the separation of the alternately arranged PLLA/PDLA chain segments in molten state as a compatibilizer. Furthermore, the generation of these copolymers does not result in a significant increase in melt viscosity of the blends. These findings suggest new opportunities for the high-throughput processing of SC-PLA materials into useful products.Keywords:polylactide;stereocomplex;crystallization;copolymer;compatibilization
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高影响因子
DESALINATION
·
2015
·
IF 3.756
Shengji Xia,Muzi Ni,Tongren Zhu,Yu Zhao,Nana Li
The peculiar two-dimensional structure and chemical properties of GO offer a facile stacking method for preparing this new type of membrane. In this study, GO membranes were made using the pressure-assisted filtration method, which was cross-linked by three diamine monomers on a polyethersulfone (PES) support. The prepared GO membranes had a well stacked layer structure that was formed by nanosheets and were stable because they were covalently bonded by cross-linking. The effects of various diamine monomers on the synthesized membrane were analyzed using several characterization methods, including Fourier transform infrared spectroscopy (FTIR), dynamic contact angle (CA) measurements, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The performance of the GO membranes for removing natural organic matter (NOM) was investigated in detail. The permeate water was analyzed for dissolved organic carbon (DOC), ultraviolet absorbance (UV 254 ), molecular weight distribution (MWD) and fluorescence excitation–emission matrices (EEMs). The results showed that C–N covalent bonds formed between the GO and diamine and effectively suppressed the interlayer spacing and stretching, which resulted in the best ethylenediamine performance. Overall, the ultrathin GO composite membrane not only effectively removed various contaminants from the NOM, but also qualified the water flux and fouling resistance performance.
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高影响因子
DYES AND PIGMENTS
·
2014
·
IF 3.468
Xu-Feng Zang,Teng-Long Zhang,Zu-Sheng Huang,Zafar Iqbal,Dai-Bin Kuang,Lingyun Wang,Herbert Meier,Derong Cao
Three organic dyes with double D–A system were synthesized and applied in the dye-sensitized solar cells. These dyes contain phenothiazine as an electron donor and cyanoacetic acid as an acceptor/anchor. Linkages were incorporated at the ortho-, meta- and para-positions and their impact on the performance of photovoltaic was observed. Among them, the dye with a para-position linkage exhibited the highest short-circuit photocurrent density (12.26 mA cm −2 ) and open-circuit photovoltage (756 mV), leading to the best overall efficiency (6.14%) due to better light harvesting capacity under standard global 1.5 AM conditions. Under similar measuring conditions the dyes with ortho and meta-position linkage delivered sunlight to electricity conversion efficiencies of 5.25% and 5.85% respectively. The result shows the position isomer of the linkage units influences the photophysical characteristics, dye loading on the film and electron lifetime .
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高影响因子
Chemical and Biological Technologies in Agriculture
·
2026
·
IF 5.8
Tian Shu,Cheng Feng,Wu Pan,Jia Xuewei,Qu Lili,Xu Chunping
Background Microbial exopolysaccharides (EPS) are renewable biopolymers of increasing importance in the agri-food sector, and producing them from low-cost substrates offers a route to valorize agro-industrial resources. Aureobasidium pullulans is an industrially important fungus that secretes the α-glucan pullulan; however, the structure of the EPS it produces under lactose fermentation—a means of upgrading a low-value, dairy-derived carbon source—has not been clearly defined, which limits its rational use as an agri-food bioproduct. This study aimed to produce, structurally characterize, and preliminarily evaluate the physiological activity of this EPS. Results A homogeneous EPS was obtained by ethanol precipitation, Sevag deproteinization, and gel-filtration chromatography. Fourier-transform infrared spectroscopy indicated an α-configured, neutral polysaccharide, and gas chromatography identified glucose as the sole monosaccharide. Size-exclusion chromatography coupled with multi-angle laser light scattering showed a high-molecular-weight polymer. One- and two-dimensional NMR analyses established that the EPS is a linear pullulan-type α-D-glucan with the repeating unit [→6)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→] n, in which two α-(1→4)-linked glucose residues alternate with an α-(1→6) linkage. In a high-fat-diet-induced obese rat model, dietary supplementation with the glucan attenuated body-weight gain, improved serum lipid profiles (TG, TC, HDL-C/TC), and lowered serum endotoxin and tumour necrosis factor-α, together with enhanced colonic short-chain fatty acid production, consistent with fermentation of the glucan by the gut microbiota. Conclusions Lactose fermentation by A. pullulans yields a structurally defined, linear pullulan-type α-D-glucan, demonstrating a route to convert a low-value dairy-derived substrate into a value-added biopolymer. Its prebiotic-associated metabolic effects indicate potential as a functional ingredient for the agri-food chain and warrant further mechanistic and safety studies. Graphical abstract
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Analytical Methods
·
2023
·Vol. 15
·期 44
·6009-6014
·
IF 3.1
Qin-Feng Zhang,Hua-Ming Xiao,Na An,Quan-Fei Zhu,Yu-Qi Feng
Vitamin D (VD) metabolites are involved in a variety of important metabolic processes and physiological effects in organisms. Profiling of VD metabolites favors a deep understanding of the physiological role of VD. However, VD metabolites are difficult to detect due to their high chemical structural rigidity, structural similarity, and low sensitivities under liquid chromatography-tandem mass spectrometry (LC-MS). Herein, we present a chemical derivatization assisted LC-MS/MS strategy for the detection of VDs, in which 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) is employed to derivatize the conjugated diene of VD metabolites and provides sensitizing reporters for MS detection. After PTAD derivatization, the sensitivities of seven VD metabolites increased by 24–276 folds, with the limits of detection ranging from 3 to 20 pg mL−1. Using this method, we achieved a sensitive and accurate quantification of 7 VD metabolites (vitamin D2, vitamin D3, 25-hydroxyvitamin D2, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D2, 1,25-dihydroxyvitamin D3, and 1,24,25-trihydroxyvitamin D3) of the VD metabolic pathway in different trace biological samples, including human serum, mouse tissues (namely liver, kidney, lung, and spleen), and cells. We believe that the present method can provide a promising tool for an in-depth analysis of VD metabolism.
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PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Kun Liu,Shengyue Tang,Wenyan Li,Wei Wen,Shan Ding,Mingxian Liu,Hong Li,Changren Zhou,Binghong Luo
To date, designing a perfect poly(d,l-lactide) (PDLLA) bone repair material still remains a major challenge. Inspired by the superior cell affinity, osteogenic activity, and mechanical properties of polysaccharide chitin whiskers, here, positively charged chitin whiskers (HCHW) and negatively charged maleated chitin whiskers (mCHW) are prepared for strengthening and biofunctionalizing the PDLLA membrane via a layer-by-layer (LBL) electrostatic self-assembly method. At a pH value of 4.3, the process of LBL electrostatic self-assembly between the HCHW and mCHW on the membranes is successfully performed, which can be directly proved by the cross-sectional morphology, light transmittance, surface composition, and topography of the membranes. Especially, polydopamine, as an intermediate layer, can greatly enhance the stability and adhesion of the first chitin whisker layer on the PDLLA substrate. Compared with the PDLLA membrane, the mechanical properties of self-assembly membranes are highly enhanced and controllable by adjusting the number of self-assembly whisker layers. Furthermore, in vitro biological evaluations indicate that the HCHW-assembled surface has a higher cell affinity than that of the mCHW-assembled one, which may be attributed to different protein adsorption. Meanwhile, interesting directional cell migration behavior is observed on the HCHW-assembled surface, which can be explained by the guiding effect of surface ordered topology and collective cell migration. These findings provide a new strategy for designing bioactive PDLLA composites with superior and tunable mechanical properties for bone regeneration materials.
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高影响因子
International Journal of Nanomedicine
·
2021
·
IF 6.4
Qiangqiang Wang,Xiaoke Sun,Xin Huang,Jianmei Huang,Muhammad Waqqas Hasan,RuoFeng Yan,Lixin Xu,Xiaokai Song,Xiangrui Li
Background Hepatocellular carcinoma-associated antigen 59 (HCA59) from excretory/secretory products of Haemonchus contortus is known to have the ability to modulate the functions of host cells. However, its immunogenicities using different nanoparticles adjuvants remain poorly understood. Purpose The study aimed to select an efficient nanoparticle antigen delivery system, which could enhance the immune responses of Haemonchus contortus HCA59 in mice. Methods Here, the immune responses induced by the recombinant protein of HCA59 (rHCA59) with poly-D,L-lactide-co-glycolide (PLGA) nanoparticles, Chitosan nanoparticles, mixture of PLGA and Chitosan nanoparticles (rHCA59-Chitosan-PLGA), and Freund’s complete adjuvant were observed, respectively, in mice. Cytokine and antibody levels induced by different groups were detected by ELISA assay. The effects of lymphocyte proliferations on different groups were examined using CCK-8 kit. Phenotypes of T cells and dendritic cells were analyzed by flow cytometry. Results On day 14 post vaccination, levels of IgM, IgG1, IgG2a, IFN-γ, IL-4, and IL-17 were significantly increased in the groups immunized with rHCA59 encapsulated with nanoparticles. After mice were vaccinated with rHCA59 loaded with Chitosan/PLGA nanoparticles, lymphocytes proliferated significantly. Additionally, the percentages of CD4 + T cells (CD3 + CD4 + ), CD8 + T cells (CD3 + CD8 + ), and dendritic cells (CD11c + CD83 + , CD11c + CD86 + ) were obviously up-regulated in the mice immunized with nanoparticles, especially in the rHCA59-Chitosan-PLGA antigen delivery system group. Conclusion The findings of this research demonstrated that rHCA59-Chitosan-PLGA antigen delivery system could induce higher immune responses in mice model and indicated that rHCA59 might be a good candidate molecule to develop nanovaccines against Haemonchus contortus in future study.
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PubMed
高影响因子
MEDICINAL CHEMISTRY RESEARCH
·
2020
·Vol. 29
·期 10
·1867-1873
·
IF 1.783
Yang Xin-Bin,Huang Yu
The water-soluble sulfated derivatives, apigenin-8-sulfonate sodium (AS) and apigenin-3′, 8-disulfonate sodium (ADS) derived from parent apigenin (AP), were synthesized and characterized by infrared (IR) spectra, hydrogen nuclear magnetic resonance ( 1 H NMR), carbon nuclear magnetic resonance ( 13 C NMR), high-resolution mass spectra (HRMS), and elemental analysis. The mice model of hepatotoxicity induced by d -Galactosamine ( d -GalN) was used to evaluate the hepatoprotective effects of AP, AS, and ADS. The results indicated that AP, AS, and ADS could reduce the level of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatic malondialdehyde (MDA) induced by d -GalN, and restore the activities of antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) toward normal levels. The histological results also suggested that AP, AS, and ADS could alleviate liver toxicity. The possible mechanisms could be ascribed to the protection role of AP, AS, and ADS, which kept hepatic cells from oxidative damage and maintain intracellular antioxidant enzyme activity. These findings uncovered that AP, AS, and ADS were able to protect liver from d -GalN-induced acute damage, and AS was the most potent hepatoprotective drug among the three compounds.
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 45
·期 3
·1721-1726
·
IF 3.288
Yin Zheng,Jiabing Chen,Youluan Lu,Xinjian Song,Zhen Shi
Three-dimensional interconnected porous carbon nanosheets were prepared through pyrolyzing sodium D-isoascorbic acid, and were thoroughly characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The specific surface area and pore size distribution of the porous carbon nanosheets were characterized by N2 adsorption desorption. The thickness of the carbon nanosheet was measured by atomic force microscopy (AFM). An electrochemical sensor was fabricated by the modification of the porous carbon nanosheets onto a glassy carbon electrode surface. The electrochemical behaviors of hydroquinone (HQ) and catechol (CA) on the electrochemical sensor were investigated by cyclic voltammetry and differential pulse voltammetry. Under the optimized conditions, the peak currents were found to be linear to the HQ and CA concentrations in the range from 0.4 to 20 μmol L−1, and the detection limits were 0.028 μmol L−1 (HQ) and 0.035 μmol L−1 (CA), respectively.
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高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
·
2020
·
IF 3.69
Liping Wang,Qiangwei Chen,Suqi Zhuang,Yuying Wen,Wanqiu Cheng,Zhijun Zeng,Tao Jiang,Chunping Tang
Ethnopharmacological relevance Anoectochilus roxburghii ( A. roxburghii ) is a popular folk medicine in many Asian countries, which has been used traditionally for treatment of some diseases such as diabetes, tumors, hyperlipemia , and hepatitis. The ethanol extract from A. roxburghii was recently shown to exert better ability to scavenge free radicals in vitro and possess antioxidant on natural aging mice in vivo . Aim of the study This study is to characterize the chemical composition, and investigate the protective effect of the A. roxburghii flavonoids extract (ARF) against hydrogen peroxide (H 2 O 2 )-induced oxidative stress in LO2 cells in vitro and D-galactose (D-gal)-induced aging mice model in vivo , and explore the underlying mechanisms. Materials and methods The chemical components of the flavonoids extract fro m A. roxburghii were detected by ultraperformance lipid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UPLC-QTOF-MS/MS). H 2 O 2 was used to establish an oxidative stress model in LO2 cells. Cytotoxic and protective effects of ARF on the LO2 cells were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Moreover, the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and malondialdehyde (MDA) in cell supernatants were measured by commercial reagent kits. Kun-Ming mice were induced to aging with D-gal (400 mg/kg, BW) by subcutaneous injection for 58 days. From the 28th day to the 58th day of D-gal treatment, ARF (122.5, 245 and 490 mg/kg, BW) and vitamin E (100 mg/kg, BW) were orally administrated to aging mice once a day for consecutive 30 days. After 25 days of the treatment with ARF, learning and memory were assessed using Morris Water Maze (MWM). At the end of the test period, the animals were euthanized by cervical dislocation , and the levels of SOD, GSH-PX, and MDA in serum, liver homogenates and brain homogenates were measured. The levels of monoamine oxidase (MAO) and acetylcholinesterase (AchE) were determined in brain homogenates. Skin and liver histopathological morphology were observed by H&E staining. Furthermore, antioxidant-related gene expression levels in the liver were carried out by quantitative real-time polymerase chain reaction (qRT-PCR). Results Nine flavonoids were identified in the extracts of A. roxburghii . In vitro assay, a high concentration of ARF (>612.5 μg/ml) reduced the survival rate and had toxic effects on LO2 cells. In addition, ARF (245 μg/ml, 490 μg/ml) and Vitamin C (200 μg/ml) markedly inhibited generations of MDA and increased activities of SOD, GSH-PX in H 2 O 2 -induced LO2 cells supernatants. In vivo assay, ARF (122.5 mg/kg, 245 mg/kg and 490 mg/kg) and Vitamin E (100 mg/kg) not only ameliorated learning and memory ability but also improved skin and liver pathological alterations. Strikingly, ARF significantly decreased MDA and MAO levels, markedly enhanced antioxidant enzyme (SOD and GSH-PX) activities. Further, compared to the D-gal group, ARF could obviously up-regulate glutathione peroxidase-1 (GPx-1) and glutathione peroxidase-4 (GPx-4) mRNA levels. Conclusions These findings suggested that ARF protects LO2 cells against H 2 O 2 -induced oxidative stress and exerts the potent anti-aging effects in D-gal aging mice model, which may be related to the inhibition of oxidative stress. Flavonoid compounds may contribute to the anti-oxidative capability and modulating aging.
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PubMed
高影响因子
ELECTROPHORESIS
·
2020
·Vol. 41
·期 12
·1060-1066
·
IF 3.081
Zijie Feng,Yue Yang,Guangfu Xu,Yingxiang Du,Xiaodong Sun
The authors describe a synergistic system for nanoparticle based chiral separation. It is based on the use of a conventional chiral selector hydroxyproyl-β-cyclodextrin and a kind of gold nanoparticle functionalized with D-penicillamine as an additive. This nanomaterial displays a synergistic effect on the efficiency of the enantioseparation of the chiral drugs amlodipine, tropicamide, and ofloxacin. A comparative study on the enantioseparation capability of three separation systems, viz. (a) single hydroxyproyl-β-cyclodextrin system, (b) achiral citrate capped gold nanoparticle/ hydroxyproyl-β-cyclodextrin system, and (c) chiral D-penicillamine functionalized gold nanoparticle/ hydroxyproyl-β-cyclodextrin system was performed. The results show that the D-penicillamine functionalized gold nanoparticle/hydroxyproyl-β-cyclodextrin synergistic system has remarkable superiority. The effects of concentrations of D-penicillamine functionalized gold nanoparticle and hydroxyproyl-β-cyclodextrin, of buffer pH value and concentration, and of applied voltage on the performance of enantioseparation were investigated.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2020
·Vol. 27
·期 11
·11990-12000
·
IF 3.056
Cui Yanping,Thathsarani Nimesha,Peng Liang,Gao Ya,Lei Lidan,Zhou Zhengwei,Liang Lili,Shi Xiaoyan
Innovative paramagnetic one-dimensional (1-D) core-shell Fe-Ag@AgCl visible light-driven photocatalysts are synthesized through a template-assisted electrodeposition method trailed by FeCl 3 in-situ oxidation. The metallic nature of Fe-Ag@AgCl is confirmed through scanning electron microscopy (SEM) and crystal nature through X-ray diffraction (XRD). The controllable diameter of Fe-Ag is obtained through the selection of hollow size of the polycarbonate (PC) template. Electron impedance spectroscopy (EIS) confirms through the introduction of Fe to the Ag core that has prolonged the recombination of electron and hole. Escherichia coli ( E. coli ) are employed as the target bacteria to evaluate the photocatalytic disinfection performances. A total of 1.30 mg of Fe-Ag@AgCl is proved to be able to completely inactivate 10 7 CFU (colony forming units)/mL after 120 min of visible light irradiation. The transition electron microscopy (TEM) confirms the stability of the material after the photo reaction. As Fe-Ag@AgCl possesses magnetic properties, the material is recovered through the application of an external magnetic field. SEM images and results of 3D emission extraction matrix (EEM) depict that the bacteria cell death is caused by membrane permeability changes caused by the reduction of membrane associated proteins.
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高影响因子
危险品化学品经营许可证（带存储）