ANALYTICAL CHEMISTRY
·
2018
·
IF 6.042
Xiaohua Zhu,Lin Fan,Shigong Wang,Chunyang Lei,Yan Huang,Zhou Nie,Shouzhuo Yao
As one of the emerging inorganic graphene analogues, two-dimensional titanium carbide (Ti3C2) nanosheets have attracted extensive attention in recent years because of their remarkable structural and electronic properties. Herein, a sensitive and selective nanoprobe to fluorescently probe phospholipase D activity was developed on the basis of an ultrathin Ti3C2 nanosheets-mediated fluorescence quenching effect. Ultrathin Ti3C2 nanosheets with ∼1.3 nm in thickness were synthesized from bulk Ti3AlC2 powder by a two-step exfoliation procedure and further modified by a natural phospholipid that is doped with rhodamine B-labeled phospholipid (RhB-PL-Ti3C2). The close proximity between RhB and Ti3C2 leads to efficient fluorescence quenching (>95%) of RhB by energy transfer. Phospholipase D-catalyzed lipolysis of the phosphodiester bond in RhB-PL results in RhB moving away from the surface of Ti3C2 nanosheets and subsequent fluorescence recovery of RhB, providing a fluorescent “switch-on” assay for the phospholipase D activity. The proposed nanoprobe was successfully applied to quantitatively determine phospholipase D activity with a low limit of detection (0.10 U L–1) and to measure its inhibition. Moreover, in situ monitoring and imaging the activity of phospholipase D in living cells were achieved using this biocompatible nanoprobe. These results reveal that Ti3C2 nanosheets-based probes exhibit great potential in fluorometric assay and clinical diagnostic applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEUROTOXICOLOGY
·
2018
·
IF 3.076
Jing Zheng,Juan Chen,Xiaohan Zou,Fang Zhao,Mengqi Guo,Hongbo Wang,Tian Zhang,Chunlei Zhang,Wei Feng,Isaac N. Pessah,Zhengyu Cao
Saikosaponins (SSs) are a class of naturally occurring oleanane-type triterpenoid saponins found in Radix bupleuri that has been widely used in traditional Chinese medicine. As the main active principals of Radix bupleuri , SSs have been shown to suppress mouse motor activity, impair learning and memory, and decrease hippocampal neurogenesis. In the present study, we investigated the effect of five SSs (SSa, SSb1, SSb2, SSc, and SSd) on neuronal viability and the underlying mechanisms in cultured murine neocortical neurons. We demonstrate that SSa, SSb1 and SSd produce concentration-dependent apoptotic neuronal death and induce robust increase in intracellular Ca 2+ concentration ([Ca 2+ ] i ) at low micromolar concentrations with a rank order of SSd > SSa > SSb1, whereas SSb2 and SSc have no detectable effect on both neuronal survival and [Ca 2+ ] i . Mechanistically, SSd-induced elevation in [Ca 2+ ] i is the primary result of enhanced extracellular Ca 2+ influx, which likely triggers Ca 2+ -induced Ca 2+ release through ryanodine receptor activation, but not SERCA inhibition. SSd-induced Ca 2+ entry occurs through a non-selective mechanism since blockers of major neuronal Ca 2+ entry pathways, including L-type Ca 2+ channel, NMDA receptor, AMPA receptor, Na + -Ca 2+ exchanger, and TRPV1, all failed to attenuate the Ca 2+ response to SSd. Further studies demonstrate that SSd increases calcein efflux and induces an inward current in neocortical neurons. Together, these data demonstrate that SSd elevates [Ca 2+ ] i due to its ability to increase membrane permeability, likely by forming pores in the surface of membrane, which leads to massive Ca 2+ influx and apoptotic neuronal death in neocortical neurons.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2019
·
IF 0
Ji Fu Du,Zhen Dong,Xin Yang,Long Zhao
Glycidyl methacrylate (GMA) was grafted onto the surface of HDPE particles by radiation grafting and emulsion graft copolymerization. And subsequent ring-opening reaction of expoxy groups in poly-GMA graft chains with N-methylglucamine (NMG) was conducted to synthesis the boron adsorbent. The synthesis condition (radiation dose and NMG concentration) was optimized and characterized by IR and SEM. Adsorption behaviors of the boron adsorbent for boron removal presented that adsorption kinetics was well described by pseudo-second-order kinetic mode. The adsorption isothermal was well fitted with both Langmuir and Freundlich isotherm models. The adsorption capacity for boron reached 15.63 mg/g at optimal pH 8. Dynamic experiment revealed that boron could be efficiently adsorbed by the boron adsorbent and fully desorbed using 13 BV of 1 mol/L HCl.
✓ 已验证
产品关联
DOI
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2019
·
IF 3.571
Feier Cheng,Lin Han,Yao Xiao,Chuanying Pan,Yunlong Li,Xinhui Ge,Yao Zhang,Shaoqing Yan,Min Wang
d-chiro-Inositol (DCI) is a biologically active component found in tartary buckwheat, which can reduce hyperglycemia and ameliorate insulin resistance. However, the mechanism underlying the antidiabetic effects of DCI remains largely unclear. This study investigated the effects and underlying molecular mechanisms of DCI on hepatic gluconeogenesis in mice fed a high fat diet and saturated palmitic acid-treated hepatocytes. DCI attenuated free fatty acid uptake by the liver via lipid trafficking inhibition, reduced diacylglycerol deposition, and hepatic PKCε translocation. Thus, DCI could improve insulin sensitivity by suppressing hepatic gluconeogenesis. Subsequent analyses revealed that DCI decreased hepatic glucose output and the expression levels of PEPCK and G6 Pase in insulin resistant mice through PKCε-IRS/PI3K/AKT signaling pathway. Likewise, such effects of DCI were confirmed in HepG2 cells with palmitate-induced insulin resistance. These findings indicate a novel pathway by which DCI prevents hepatic gluconeogenesis, reduces lipid deposition, and ameliorates insulin resistance via regulation of PKCε-PI3K/AKT axis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Functional Foods
·
2019
·
IF 3.197
Ze-hua Li,Ming Cai,Kai Yang,Pei-long Sun
Nanoemulsion loading finger citron essential oil (FCEO) can maintain bioactivities of FCEO and increase its water solubility. In this study, stability of FCEO nanoemulsions during digestion in vitro were evaluated and the release kinetics of d-limonene (the main component in the oil) were developed. Compared with free oil released to maximum for 6 min, all nanoemulsions kept sustainably releasing for 300 min or longer. Droplet size of the nanoemulsions increased from 10–18 nm of initial to 105–1106 nm after digestion, indicating coalescence or aggregation occurred. Zero-order, Hixcon-Crowell, Higuchi, Ritger-Peppas and Niebergull models were used to describe the release kinetics. The results showed zero-order and Ritger-Peppas models were the best fit models at mouth and intestinal stage, respectively. Both zero-order and Higuchi models were appropriate at gastric stage. This study could demonstrate the digestion mechanisms of FCEO loaded nanoemulsion and facilitate the design of hydrophobic nutraceuticals delivery systems in food industry.
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 21
·2706-2715
·
IF 4.76
Yongjie Yuan,Lifang He,Jindi Li,Hailiang Zhang
A series of luminescent side chain polymers containing a D–π-A structure and different flexible spacer lengths, namely, poly[(Z)-ω-(4-(1-cyano-2-(4-cyanophenyl)vinyl)phenoxy)alkyl methacrylate]s (PMmPVPCN, m = 2, 4, 6, 8), were successfully prepared. With the combination of aggregation-induced emission enhancement (AIEE) luminogens and mesogens, the resultant polymers are expected to possess both liquid crystal characteristics and AIEE characteristics. The phase structure of PMmPVPCN was explored by differential scanning calorimetry (DSC), polarized optical microscopy (POM), and one-dimensional wide-angle X-ray diffraction (1D WAXD). Photophysical properties of PMmPVPCN were studied by UV spectra and fluorescence spectra. Test results suggested that the phase structure of PMmPVPCN transformed from the amorphous phase (PMmPVPCN, m = 2, 4) to the nematic phase (PMmPVPCN, m = 6, 8) with the increase of polymer spacer length. All the synthetic monomers and polymers exhibited AIEE properties and the luminescence behavior of PMmPVPCN was associated with their chemical structure. The solid fluorescence quantum yields of PMmPVPCN increased from 22.4% to 42.7% with increasing spacer length. The polymer films also showed reversible fluorescence photo-responsive properties. The emission color and the emission intensity of polymer films changed when exposed to a 365 nm UV lamp. The change process was reversible and they could turn back to their original state when irradiated with a 254 nm UV lamp or heated at higher temperature.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Yi-bao Jiang,Chao Gao,Xian Zhang,Jin-shui Yao,Qin-ze Liu,Xiao-xia Cai
A novel triphenylamine derivative, 4,4′ -bis-([1,10]phenanthrolin-2-yl) imidazo -triphenylamine (IPTPA) with an A-π-D-π-A structure, has been synthesized and characterized. The UV absorption , single and two-photon fluorescence spectra showed that IPTPA was highly sensitive to Ag + with a lower detection limit of 3.97 nmoL/L and a moderate binding constant of 2.16 × 10 5 /M at room temperature . The two-photon active cross-section of IPTPA was calculated with a value of 94.68 GM at 800 nm in the tris-HCl buffer solution. The binding mechanism between IPTPA and Ag + were explored by the Job plot, ESI-MS and 1 H NMR. The A-π-D-π-A structure of IPTPA was substituted by the A-π-D-π-D structure of IPTPA-Ag to improve the fluorescence. Furthermore, the fluorescence microscopy images indicated that IPTPA could detect Ag + in living cells.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 2
·767-772
·
IF 1.289
Dagen Zhong,Zonghua Liu,Shasha Xie,Wei Zhang,Yuanming Zhang,Wei Xue
This work is to develop a novel dual drug delivery system that can simultaneously load and release 18β-glycyrrhetinic acid (GA, a hydrophobic drug) and bovine serum albumin (BSA, hydrophilic model drug) in a single formulation. The system consists of poly( D,L -lactic) (PDLLA) microspheres embedded in calcium alginate hydrogel beads. The GA-loaded microspheres were first prepared and then dispersed in the aqueous solution of sodium alginate and BSA. The resulting suspension was dropped into aqueous calcium chloride solution to obtain the dual drug delivery system. The morphology of the microspheres and beads, the drug content and loading efficiency, the interaction between GA and PDLLA, and the drug release behaviors were studied. Scanning electron microscope (SEM) revealed that the PDLLA microspheres were homogeneously distributed in the beads. Differential scanning calorimetry (DSC) measurement suggested certain interaction between GA and PDLLA, and the crystal structure of GA was influenced by the polymer. The dual release in vitro showed a rapid BSA release but a sustained GA release in all the systems. Furthermore, the release rate of BSA was accelerated by increasing PDLLA/alginate ratio, while the release rate of GA was decreased, and the release of both hydrophobic and hydrophilic drugs could be adjusted by changing the ratio of PDLLA/alginate. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 20122
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Jianmei Wang,Huihui Zhu,Yuanhong Xu,Wenrong Yang,Ao Liu,Fukai Shan,Mengmei Cao,Jingquan Liu
Herein, a uniform three-dimensional (3-D) graphene nanodots-encaged porous gold electrode was prepared via ion beam sputtering deposition (IBSD) and mild corrosion chemistry for efficient enzyme electrode fabrication. Enzymes, like glucose oxidase and catalase , were modified with pyrene functionalities and then loaded into the graphene nanodots encaged porous gold electrode via non-covalent π–π stacking interaction between pyrene and graphene. The fabricated enzyme electrodes showed profound reusability and repeatability, high sensitivity, inherent selectivity and enhanced detection range. As for glucose analysis a broad linear range from 0.05 to 100 mM was obtained and the linear range for hydrogen peroxide was 0.005 to 4 mM. Detection limits of 30 μM for glucose and 1 μM for hydrogen peroxide were achieved ( S / N = 3), respectively. These electrodes can be applied to analyze the clinical samples with reliable results. The formation mechanism and 3-D structure of the porous electrode were investigated using high resolution transmission electron microscope (HRTEM), atomic force microscopy (AFM), scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS). Most importantly, various other ideal biosensors can be fabricated using the same porous electrode and the same enzyme modification methodology.
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2015
·
IF 4.074
Cong Chen,Yan Meng,Sheng Li,Wenhua Wu,Chuanjun Liu,Xiaojuan Xu,Lina Zhang
A polysaccharide coded as PR-CA was extracted from Polyporus rhinoceros and determined to be a β-(1→3)- d -glucan with multiple branches. The weight-average molecular weights ( M w ) of PR-CA in dimethylsulfoxide (DMSO) and in water were determined with static light scattering (SLS) to be 3.57 × 10 5 and 1.79 × 10 7 , indicating existence of the single chains in DMSO and co-existence of single chains and aggregates in water. Moreover, the stiffness of single chains of PR-CA in water was directly visualized by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The hollow structure of PR-CA nanofibers with width of 30–40 nm and length of ∼350 nm formed in the water/DMSO (9:1, v:v) was demonstrated by a fluorescent probe tetraphenylethylene (TPE) via aggregation-induced emission (AIE). The formation of PR-CA nanofibers was ascribed to the parallel aggregation of the extended PR-CA chains due to the hydrogen bonding and hydrophobic interaction. This work offered valuable results for promising applications of natural branched β-glucans in the biological fields of drug inclusion, delivery and disease diagnosis.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2014
·
IF 2.129
Peng Wang,Bang Lin Li,Nian Bing Li,Hong Qun Luo
In this contribution, a luminescent gold nanoclusters which were synthesized by bovine serum albumin as novel fluorescent probes were successfully utilized for the determination of d -penicillamine for the first time. Cupric ion was employed to quench the strong fluorescence of the gold nanoclusters, whereas the addition of d -penicillamine caused obvious restoration of fluorescence intensity of the Cu 2+ -gold nanoclusters system. Under optimum conditions, the increment in fluorescence intensity of Cu 2+ -gold nanoclusters system caused by d -penicillamine was linearly proportional to the concentration of d -penicillamine in the range of 2.0 × 10 −5 –2.39 × 10 −4 M. The detection limit for d -penicillamine was 5.4 × 10 −6 M. With the off–on fluorescence signal at 650 nm approaching the near-infrared region, the present sensor for d -penicillamine detection had high sensitivity and low spectral interference. Furthermore, the novel gold nanoclusters-based fluorescent sensor has been applied to the determination of d -penicillamine in real biological samples with satisfactory results.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2017
·
IF 0
Jiale Cui,Zhihua Zhou,Yun Yang,Wenjuan Liu,Yunfei Zhao,Cheng Peng,Tianlong Huang,Hu Zhou,Lihua Liu,Qiao Zhang
In order to improve hydrophilicity and settle the acidity in hydrolysis, a novel ethanediamine (EDA) and maleic anhydride (MAH) modified poly(D,L-lactide-co-glycolide) (PLGA) polymer (EMPLGA) was synthesized. Fourier Transform Infrared Spectrometer (FTIR), Gel Permeation Chromatography (GPC), Nuclear Magnetic Resonance (1HNMR), titration and the water contact angles were employed to characterize the synthesized polymer. The effects of various polymerization conditions on weight average molecular mass (Mw), polydispersity index (PDI) and anhydride content of MPLGA were investigated. The degradation behaviors of PLGA, MPLA and EMPLGA were also studied by observation of the changes of the pH value of incubation medium, molecular weight and weight loss ratio for a time interval of 25 days in-vitro, respectively. The results showed that MPLGA with high anhydride content was successfully obtained by directly ring-opening polymerization and ethanediamine was further grafted onto MPLGA, and there is almost unchanged in Mw between MPLGA and EMPLGA polymers. The introduction of anhydride and amino groups improved the hydrophilicity of PLGA. A uniform degradation of EMPLGA was observed in comparison with an acidity-induced auto-accelerating degradation featured by PLGA and MPLGA. The results revealed that the introduction of ethanediamine into PLGA has weakened or neutralized the acidity of PLGA degradation products.
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）