ACTA PHARMACOLOGICA SINICA
·
2018
·Vol. 40
·期 1
·133-142
·
IF 3.562
Zhang Yi-ting,Yu Yu-qi,Yan Xiao-xia,Wang Wen-jie,Tian Xiao-ting,Wang Le,Zhu Wei-liang,Gong Li-kun,Pan Guo-yu
Berberine, berberrubine, thalifendine, demethyleneberberine, jatrorrhizine, and columbamine are six natural protoberberine alkaloid (PA) compounds that display extensive pharmacological properties and share the same protoberberine molecular skeleton with only slight substitution differences. The oral delivery of most PAs is hindered by their poor bioavailability, which is largely caused by P-glycoprotein (P-gp)-mediated drug efflux. Meanwhile, P-gp undergoes large-scale conformational changes (from an inward-facing to an outward-facing state) when transporting substrates, and these changes might strongly affect the P-gp-binding specificity. To confirm whether these six compounds are substrates of P-gp, to investigate the differences in efflux capacity caused by their trivial structural differences and to reveal the key to increasing their binding affinity to P-gp, we conducted a series of in vivo, in vitro, and in silico assays. Here, we first confirmed that all six compounds were substrates of P-gp by comparing the drug concentrations in wild-type and P-gp-knockout mice in vivo. The efflux capacity (net efflux) ranked as berberrubine > berberine > columbamine ~ jatrorrhizine > thalifendine > demethyleneberberine based on in vitro transport studies in Caco-2 monolayers. Using molecular dynamics simulation and molecular docking techniques, we determined the transport pathways of the six compounds and their binding affinities to P-gp. The results suggested that at the early binding stage, different hydrophobic and electrostatic interactions collectively differentiate the binding affinities of the compounds to P-gp, whereas electrostatic interactions are the main determinant at the late release stage. In addition to hydrophobic interactions, hydrogen bonds play an important role in discriminating the binding affinities.
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JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2018
·
IF 1.946
Amin Khan,Li Wang,Haojie Yu,Muhammad Haroon,Raja Summe Ullah,Ahsan Nazir,Tarig Elshaarani,Muhammad Usman,Shah Fahad,Kaleem-ur-Rehman Naveed
Three novel polymers (P(FHEMA- co -MAAT)s) having redox and photoresponsive moieties were prepared by free radical polymerization . The structures and molecular weights of the synthesized copolymers were characterized by nuclear magnetic resonance ( 1 H NMR) and gel permeation chromatography (GPC) respectively. Thermal properties, optical features and electroactive properties were studied with the help of thermogravimetric (TG), differential thermogravimetric (DTG) analysis, ultraviolet-visible spectroscopy (UV-vis) and cyclic voltammetry (CV). It was seen that synthesized copolymers had excellent redox and photoresponsive properties. These results exhibited that these polymers can be applied further for redox/photo responsive information storage devices.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 12
·8951-8962
·
IF 2.993
Wang Hongzhi,Zhou Haibin,Zhang Weiguo,Yao Suwei
Amorphous molybdenum sulfide on P-doped carbon nanotubes (MoS
x
/P-CNTs) composite with an original leaves–branch architecture for hydrogen evolution reaction (HER) is successfully fabricated by urea-assisted synthesis via a facile hydrothermal process. It is found that urea used in the process of preparation played a crucial role in the establishment of this unique structure, where leaves-like MoS
x
nanosheets are uniformly anchored on P-CNTs substrate. Besides, the optimal amount of MoS
x
on P-CNTs bundles is investigated in this paper. Due to the synergistic coupling effects of MoS
x
nanosheets and P-CNTs bundles, as a result, the unique structure maintains abundant active sites, a high electrical conductivity as well as distinctive electrons transport mechanism, which gives the optimum MoS
x
/P-CNTs composite, a higher activity for HER with an overpotential of 151 mV (vs. RHE) to reach a current density of 10 mA cm −2 and a smaller Tafel slope of 49 mV dec −1 . Stability tests indicate that the catalyst exhibits excellent electrochemical durability in 0.5 M H 2 SO 4 solution. We envision that this work could provide new insights into the rational design of MoS
x
-based electrocatalysts for energy conversion and storage.
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JOURNAL OF PROTEOME RESEARCH
·
2013
·
IF 5.056
Chengjian Wang,Zhiyu Wu,Jiangbei Yuan,Bo Wang,Ping Zhang,Ying Zhang,Zhongfu Wang,Linjuan Huang
Fast, sensitive, and simple methods for quantitative analysis of disparities in glycan expression between different biological samples are essential for studies of protein glycosylation patterns (glycomics) and the search for disease glycan biomarkers. Relative quantitation of glycans based on stable isotope labeling combined with mass spectrometric detection represents an emerging and promising technique. However, this technique is undermined by the complexity of mass spectra of isotope-labeled glycans caused by the presence of multiple metal ion adduct signals, which result in a decrease of detection sensitivity and an increase of difficulties in data interpretation. Herein we report a simplified quantitative glycomics strategy, which features nonreductive isotopic labeling of reducing glycans with either nondeuterated (d0-) or deuterated (d5-) Girard’s reagent P (GP) without salts introduced and simplified mass spectrometric profiles of d0- and d5-GP derivatives of neutral glycans as molecular ions without complex metal ion adducts, allowing rapid and sensitive quantitative comparison between different glycan samples. We have obtained optimized GP-labeling conditions and good quantitation linearity, reproducibility, and accuracy of data by the method. Its excellent applicability was validated by comparatively quantitative analysis of the neutral N-glycans released from bovine and porcine immunoglobulin G as well as of those from mouse and rat sera. Additionally, we have revealed the potential of this strategy for the high-sensitivity analysis of sialylated glycans as GP derivatives, which involves neutralization of the carboxyl group of sialic acid by chemical derivatization.
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MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Waqar Ahmad,Liang Chu,Majid Raissan Al-bahrani,Xiaoliang Ren,Jun Su,Yihua Gao
P-type nickel oxide acetylene black nanoparticles composite (NiO/AB) enables facile low cost counter electrode for dye-sensitized solar cells (DSSCs), prepared by simple chemical process and doctor-blading method. Nanocrystalline p-type NiO contributes in the improvement of holes conduction at the acetylene black surface and escalates the electrocatalytic activity, confirmed by our cyclic voltammetry and electrochemical impedance spectroscopy measurements. Owing to the improvement of electrocatalytic activity, the mutual porous acetylene black surface with p-type NiO nanoparticles counter electrode and dye-sensitized TiO 2 photoanodes yielded significantly enhanced power conversion efficiency of 7.75%, which is superior to that of 6.51% and 6.96% of AB and expensive Pt in our experiment respectively.
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ANALYTICA CHIMICA ACTA
·
2015
·
IF 4.513
Yuhan Zhu,Kai Yan,Yong Liu,Jingdong Zhang
A photoelectroactive film composed of CdS quantum dots and graphene sheets (GS) was coated on F-doped SnO 2 (FTO) conducting glass for studying the electrochemical response of p -phenylenediamine (PPD) under photoirradiation. The result indicated that the cyclic voltammogram of PPD on CdS–GS hybrid film became sigmoidal in shape after exposed under visible light, due to the photoelectrocatalytic reaction. Such a photovoltammetric response was used to rapidly optimize the photoelectrocatalytic activity of hybrid films composed of different ratios of CdS to GS toward PPD. The influences of scan rate and pH on the photovoltammetric behavior of PPD on CdS–GS film revealed that although the controlled step for electrochemical process was not changed under photoirradiation, more electrons than protons might participate the photoelectrocatalytic process. Furthermore, the photoelectroactive CdS–GS hybrid film was explored for PPD determination based on the photocurrent response of film toward PPD. Under optimal conditions, the photocurrent signal on CdS–GS film was linearly proportional to the concentration of PPD ranging from 1.0 × 10 −7 to 3.0 × 10 −6 mol L −1 , with a detection limit (3S/N) of 4.3 × 10 −8 mol L −1 . Our work based on CdS–GS hybrid film not only demonstrated a new facile photovoltammetric way to study the photoinduced electron transfer process of PPD, but also developed a sensitive photoelectrochemical strategy for PPD determination.
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Chinese Physics B
·
2013
·Vol. 22
·期 11
·117805
·
IF 1.148
Zhang Xiao-Jin,He Zhi-Qun,Wang Jing,Mu Lin-Ping,Zhao Huan,Liang Chun-Jun,Zhuang Qi-Xin,Han Zhe-Wen
In this work, we report the preparation of a series of electroluminescent (EL) devices based on a high-performance polymer, poly(p-phenylene benzobisoxazole) (PBO), and their optoelectronic properties, which have been rarely explored. The device structure is optimised using a complex cathode structure of tris-(8-hydoxyquinoline) aluminium (Alq3)/LiF/Al. By tuning the thickness of the Alq3 layer, we improve the device efficiency dramatically in an optimized condition. Further analysis reveals that the Alq3 layer in the complex cathode structure acts as a hole blocker in addition to its electron-injection role. A green light emission with a maximum brightness of 8.7 × 103 cd/m2 and a moderate current efficiency of 4.8 cd/A is obtained. These values are the highest ever reported for PBO devices. The high operational stability demonstrated by the present device makes it a promising tool for display and lighting applications. A new material is added to the selection of polymers used in this field up to now.
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MATERIALS CHEMISTRY AND PHYSICS
·
2015
·
IF 2.259
Yongliang Gui,Xuteng Xing,Chunyan Song
Reduced graphene oxide grafted with poly(p-styrenesulfonate) (rGO-g-PSS) was synthesized by i n-situ free radical polymerization . The rGO-g-PSS was used to induce formation of polyaniline (PANI) nanorod array and then assembled with MnO 2 to form rGO-g-PSS@PANI-MnO 2 hybrids. The rGO-g-PSS@PANI-MnO 2 hybrids were applied to modify electrodes and the specific capacitance (SC) of the rGO-g-PSS@PANI-MnO 2 hybrid reached 425 F/g at the scan rate of 20 mV/s, which was much higher than those of rGO-g-PSS (190 F/g), MnO 2 (203 F/g), rGO-g-PSS@PANI (305 F/g) and rGO-MnO 2 (295 F/g). In addition, the rGO-g-PSS@PANI-MnO 2 hybrid also showed good stability. These good electrochemical performances are due to that rGO-g-PSS@PANI-MnO 2 hybrid could make full use of the high SC of PANI and MnO 2 , high specific surface area and conductivity of rGO, and good interfacial properties of PSS linker.
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RSC Advances
·
2014
·Vol. 5
·期 9
·6413-6418
·
IF 3.708
Hui Li,Guoping Zhang,Libo Deng,Rong Sun,Xing Ou-Yang
Thermally responsive copolymer P(NIPAm-co-NMA) was prepared via a radical copolymerization and spun into nanofibers using electrospinning. After thermal crosslinking, the electrospun fibers were modified using KH590 and silver nanoparticles were introduced onto the fiber surface using a chemical plating method. The electrical resistance of the composite fibers containing 65.5% of silver at different temperatures was investigated and it was found that the resistance dropped by ∼60% as the temperature increased from 42 °C to 46 °C, which is consistent with the solubility transition of PNIPAm with the change of temperature as revealed by differential scanning calorimetry (DSC) measurement.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2015
·
IF 3.313
Qian Wen Bao,Wei Yuan Pan,Hao Liu,Bin Hong Liu,Zhou Peng Li
In this study, hydrogen release and uptake properties for composites of LiBH 4 with the conjugated polymer poly( p -phenylene) (PPP) were investigated. The incorporation of LiBH 4 with PPP led to a significant destabilization effect, decreasing the dehydrogenation temperature of LiBH 4 by 100 °C. Moreover, LiBH 4 could be regenerated at 450 °C under 9.0 MPa H 2 . By thorough analyses using XRD , HRTEM , FTIR , Raman, XPS as well as 11 B MAS NMR, the dehydrogenation product of LiBH 4 +PPP and the regeneration mechanism of LiBH 4 are elucidated. Also the reason of capacity degradation is discussed based on the analysis results. The formation condition of LiBH 4 was significantly moderated due to the presence of a simultaneously formed amorphous mixture of boron and carbon, which sheds light on the improvement of LiBH 4 reversibility .
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Xinzuo Fang,Long Jiao,Rui Zhang,Hai-Long Jiang
The sluggish kinetics of oxygen evolution reaction (OER) hampers the H2 production by H2O electrolysis, and it is very important for the development of highly efficient and low-priced OER catalysts. Herein, a representative metalloporphyrinic MOF, PCN-600-Ni, integrated with graphene oxide (GO), serves as an ideal precursor and template to afford bimetallic iron–nickel phosphide/reduced graphene oxide composite (denoted as Fe–Ni–P/rGO-T; T represents pyrolysis temperature) via pyrolysis and subsequent phosphidation process. Thanks to the highly porous structure, the synergetic effect of Fe and Ni elements in bimetallic phosphide, and the good conductivity endowed by rGO, the optimized Fe–Ni–P/rGO-400 exhibits remarkable OER activity in 1 M KOH solution, affording an extremely low overpotential of 240 mV at 10 mA/cm2, which is far superior to the commercial IrO2 and among the best in all non-noble metal-based electrocatalysts.
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APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Mengna Sun,Xueyuan Liu,Fei Zhang,Hongli Liu,Xicheng Liu,Shirong Wang,Yin Xiao,Dongmei Li,Qingbo Meng,Xianggao Li
Two simple hole-transporting materials, Me-QTPA and Me-BPZTPA, which consist of p -π conjugated structure, have been synthesized and studied in solid-state perovskite solar cells. Me-QTPA and Me-BPZTPA show outstanding thermal stabilities and appropriate HOMO levels; in addition, these two materials show wide band gaps, thus they can block the electron transport and hence suppress the carrier recombination. The solution-processed CH 3 NH 3 PbI 3 -based device using dopant-free Me-QTPA and Me-BPZTPA can achieve a power conversion efficiency of 9.07% and 8.16%, respectively. The perovskite solar cells with dopant-free Me-QTPA show better performance than the cells with dopant-free spiro -OMeTAD, especially in long-term stability. The power conversion efficiency for the perovskite solar cells with dopant-free Me-QTPA remains almost constant after 600 h. The dopant-free Me-QTPA layer shows strong hydrophobicity with a contact angle of 101.6° to water, which indicates that Me-QTPA has a promising long-term stability at room temperature.
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