查找使用阿拉丁产品的科研文献

Dielectric Properties of P(VDF-TrFE-CTFE) Composites Filled with Surface-Coated TiO2 Nanowires by SnO2 Nanoparticles

Qilong Zhang,Zhao Zhang,Nuoxin Xu,Hui Yang

Nanocomposites containing inorganic fillers embedded in polymer matrices have exhibited great potential applications in capacitors. Therefore, an effective method to improve the dielectric properties of polymer is to design novel fillers with a special microstructure. In this work, a combination of hydrothermal method and precipitation method was used to synthesize in situ SnO2nanoparticles on the surface of one-dimensional TiO2nanowires (TiO2NWs), and the TiO2NWs@SnO2fillers well-dispersed into the poly (vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] polymer. Hybrid structure TiO2NWs @SnO2introduce extra interfaces, which enhance the interfacial polarization and the dielectric constant. Typically, at 10 vol.% low filling volume fraction, the composite with TiO2NWs @SnO2shows a dielectric constant of 133.4 at 100 Hz, which is almost four times that of polymer. Besides, the TiO2NWs prevents the direct contact of SnO2with each other in the polymer matrix, so the composites still maintain good insulation performance. All the improved performance indicates these composites can be widely useful in electronic devices.Keywords:hybrid structure;composites;interfacial polarization;dielectric performances

Inhibitory Effect of Berberine on Broiler P-glycoprotein Expression and Function: In Situ and In Vitro Studies

Yujuan Zhang,Li Guo,Jinhu Huang,Yong Sun,Fang He,Mire Zloh,Liping Wang

Overcoming P-glycoprotein (P-gp) efflux is a strategy to improve the absorption and pharmacokinetics of its substrate drugs. Berberine inhibits P-gp and thereby increases the bioavailability of the P-gp substrate digoxin in rodents. However, the effects of berberine on P-gp in chickens are still unclear. Here, we studied the role of berberine in modulating broilers P-gp expression and function through both in situ and in vitro models. In addition, molecular docking was applied to analyze the interactions of berberine with P-gp as well as with chicken xenobiotic receptor (CXR). The results showed that the mRNA expression levels of chicken P-gp and CXR decreased in the ileum following exposure to berberine. The absorption rate constant of rhodamine 123 increased after berberine treatment, as detected using an in situ single-pass intestinal perfusion model. Efflux ratios of P-gp substrates (tilmicosin, ciprofloxacin, clindamycin, ampicillin, and enrofloxacin) decreased and the apparent permeability coefficients increased after co-incubation with berberine in MDCK-chAbcb1 cell models. Bidirectional assay results showed that berberine could be transported by chicken P-gp with a transport ratio of 4.20, and this was attenuated by verapamil (an inhibitor of P-gp), which resulted in a ratio of 1.13. Molecular docking revealed that berberine could form favorable interactions with the binding pockets of both CXR and P-gp, with docking scores of −7.8 and −9.5 kcal/mol, respectively. These results indicate that berberine is a substrate of chicken P-gp and down-regulates P-gp expression in chicken tissues, thereby increasing the absorption of P-gp substrates. Our findings suggest that berberine increases the bioavailability of other drugs and that drug-drug interactions should be considered when it is co-administered with other P-gp substrates with narrow therapeutic windows.Keywords:berberine;P-glycoprotein;inhibition;MDCK-chAbcb1 cell line;chicken

Novel homo- and co-poly(p-phenyene ether sulfone benzimidazole/sulfide sulfone benzimidazole)s: synthesis and properties

Li Zhi-min,Zhang Gang,Li Yan,Yang Jie

The homo- and co-poly(p-phenyene ether sulfone benzimidazole/sulfide sulfone benzimidazole)s (PESI/PPSSI) had been prepared by solution polycondensation of the mixtures of 4,4′-dicarboxydiphenyl ether (DCDPE) and 4,4′-dicarboxydiphenyl sulfide (DCDPS) with 3,3′,4,4′-tetraanmino diphenyl sulfone (TADS) in polyphosphoric acid (PPA). The FT-IR, 1 H-NMR, DSC, TGA, XRD were used to characterize chemical structure and thermal stabilities of the resultant homo- and co-polymers. The inherent viscosities of the resultant polymers were in the range of 0.621–0.982 dl/g at the polymer concentration of 0.5 %. They were found to have excellent thermal properties with glass transition temperatures (T g ) of 386–393 °C, 5 % weight-loss temperature (T 5% ) of 512–525 °C. These polymers showed amorphous nature as charactered by XRD. Most importantly, the resultant polymers possess good solubility that they can be soluble in various aprotic solvents such as N-methyl-2-pyrolidinone (NMP), dimethyl sulfoxide (DMSO) and 1,3-dimethyl-2-imidazolidinone (DMI) and they could be easily formed transparent, tough and flexible membranes by solution casting method. The membranes showed good mechanical properties: the tensile strengths and Young’s Modulus were in the range of 68.8–98.6 MPa and 2.1–2.8 GPa, respectively.

Reversal of P-glycoprotein-mediated multidrug resistance by doxorubicin and quinine co-loaded liposomes in tumor cells

Qiying Shen,Liyan Qiu

Preparation and properties of Ni-W-P-TiO2 nanocomposite coatings developed by a sol-enhanced electroplating method

Zhen He,Yu Zhou,Yuxin Wang,Pingyi Guo,Wensen Jiang,Caizhen Yao,Xin Shu

Several Ni-W-P-TiO 2 nanocomposite coatings were developed by the sol-enhanced electroplating method. The phase and elemental compositions of coatings were determined, and the surface and cross-section morphology were characterized. The mechanical and corrosion performance were systematically tested. The results revealed the addition of 5 ml·L −1 TiO 2 sol caused a compact coating surface, while higher concentrations of TiO 2 reduced the coating thickness and led to the inferior surface microstructure. The comparison in physiochemical properties of prepared coatings confirmed the superior performance of the Ni-W-P-TiO 2 nanocomposite coating at 5 ml·L −1 TiO 2 sol addition. Under this condition, the best mechanical properties were achieved when abrasive wear was the dominating wear-resistance mechanism, and the best corrosion resistance was obtained due to its smooth and compact surface microstructure.

P-doped Co9S8 nanoparticles embedded on 3D spongy carbon-sheets as electrochemical catalyst for lithium-sulfur batteries

Yongpeng Li,Da Lei,Tianyi Jiang,Junling Guo,Xiaoyu Deng,Xu Zhang,Ce Hao,Fengxiang Zhang

Co 9 S 8 can catalyze polysulfides conversion in Lithium sulfur batteries (LSBs) owing to its metallic nature and rich catalytic sites. However, its catalytic activity and chemical adsorption is not strong enough to suppress the shuttle effect of Lithium polysulfides (LiPS) under high sulfur loading. Herein, Phosphorous (P)-doped Co 9 S 8 nanoparticle was synthesized and embedded into 3D Spongy carbon (SC) sheets as electrochemical catalyst for LSBs. Our Density functional theory (DFT) calculations and experimental results revealed that moderate P doping can modulate the electronic structure of Co 9 S 8 and simultaneously improve its interaction with LiPS and promote LiPS conversion. When P-doped Co 9 S 8 nanoparticles are in situ formed and homogeneously distributed on 3D spongy carbon sheet matrix, the resulting P-Co 9 S 8 @SC can ensure good exposure of their adsorption and catalytic sites. As a result, the LSB based on an optimized P-Co 9 S 8 @SC modified polypropylene separator exhibited excellent cycling stability (capacity decay of 0.05% per cycle over 900 cycles at 1 C) and high areal capacity (4.38 mAh cm −2 at 5.6 mg cm −2 sulfur loading at 0.1 C). Our work demonstrates that moderate heteroatom doping is a promising strategy to develop effective polysulfides catalysis.

N, P co-doped core/shell porous carbon as a highly efficient peroxymonosulfate activator for phenol degradation

Xiaojuan Li,Lanmei Ye,Ziyu Ye,Shuhan Xie,Yueming Qiu,Fengzhen Liao,Chunxiang Lin,Minghua Liu

A nitrogen and phosphorus co-doped metal-free porous carbon (NPC) with core/shell structure was successfully synthesized by pyrolysis of ZIF-8@phytic acid (PA) and demonstrated outstanding catalytic performance on PMS activation for the degradation of phenol (98.0% within 30 min at pH = 7.0). Results suggested that optimized N-P co-doping strategy played a synergistic effect in promoting the catalytic activity of NPC. In addition, NPC displayed excellent acid-base tolerance (pH = 3.0–10.0) and insensitive to anions (Cl − , HCO 3 – and H 2 PO 4 − ) and humic acid when employed as PMS activator for phenol degradation. Based on quenching tests, electron paramagnetic resonance (EPR) measurements and electrochemical analysis, singlet oxygen ( 1 O 2 ) is the key active specie and the surface-bound sulfate radical (SO 4 − ) plays an auxiliary role in the removal of phenol in NPC/PMS system while surface electron transfer is also a non-radical pathway. Large BET specific surface areas (SSA), total pore volumes (TPV) and hierarchical porous structure are beneficial to expose more active sites (essentially graphite N and C O) for generating 1 O 2 and surface-bound SO 4 − to enhance catalytic performance of NPC. This work opens up a new way for the synthesis of highly efficient N-P co-doped metal-free PMS activators and provides novel insights into the mechanism of PMS activation by NPC.

Efficient preparation of P-doped carbon with ultra-high mesoporous ratio from furfural residue for dye removal

Xiang Zhou,Xiaohao Liu,Fenglei Qi,Haixia Shi,Ying Zhang,Peiyong Ma

P-doped mesoporous carbon material is receiving increasing attention in various fields due to its special physicochemical properties, but the research in the field of pollutant removal is rarely reported. Herein, P-doped furfural residue-based carbon materials (PFRC) with ultra-high mesoporous ratio (93.9%), narrow pore size distribution and large surface area (1769.4 m 2  g −1 ) was prepared by a simple method of fast pyrolysis of phosphoric acid treated furfural residue (FR). A series of characterizations were carried out to explore the physicochemical properties and P-doping mechanism of the materials systematically. With the increase of the activation temperature, the evolution of the P-doped structure is as follows: adsorbed phosphate → P-O-C aromatic  → O3P-C aromatic  → O2P-C2 aromatic  → OP-C3 aromatic . The PFRC500 prepared at 500 °C has the most abundant P-O-C aromatic and P-C aromatic structures, which lead to a higher specific surface area, more developed pore structure and more graphite edge defects than other PFRCs. Methylene blue (MB) adsorption studies showed that PFRC500 had a good adsorption performance with 486 mg g −1 equilibrium adsorption capacity and 97.2% of removal rate (T = 298 K, C 0  = 100 mg L −1 ). The adsorption kinetics and thermodynamics were studied. The role of P structure in MB adsorption was explored for the first time. the adsorption mechanism was explored. The P-O-C aromatic , O3P-C aromatic and O2P-C2 aromatic structures are the main chemical adsorption sites, but C3 aromatic -PO is not. This work can provide guidance for the design of P-doped mesoporous carbon materials with better adsorption performance in the future.

Multifunctional integrated electrochromic device by p-n conductive polymers for self-powered smart windows and miniaturized spectrometers

Zhang Xiaojian,Hao Lu,Xie Juxuan,Tan Zhaohong,Li Shuaiqi,Gan Chongwu,Xiong Wei,Duan Xianghao,Li Shuai,Xu Zishuo,Zhang Kai,Wang Yazhong,Tang Haoran,Huang Fei

Electrochromic devices enable dynamic modulation of light and heat, yet their broader adoption is hindered by limited color tunability, slow switching kinetics, and low coloration efficiency. Here, we present a complementary organic electrochromic device that addresses these challenges by employing dual conductive polymers: poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) and poly(benzodifurandione). The resulting device delivers exceptional performance, featuring a high optical contrast of 51% at 570 nm, ultrafast switching speeds (0.17/0.36 s for coloration/bleaching), a record-high coloration efficiency (1688 cm 2 C⁻ 1 at 550 nm), and excellent cycling stability over 10,000 cycles. By integrating the device with a semitransparent organic solar cell, we realize a fully self-powered smart window with reducing indoor temperatures by 7 °C. Furthermore, coupling the electrochromic filter with a 4 × 4 organic photodetector array featuring on-chip Fabry–Pérot cavities enables a miniaturized spectrometer with 7.2 nm spectral resolution. This multifunctional electrochromic platform seamlessly bridges smart-window technology and spectral sensing, paving the way for energy-efficient, and compact optoelectronic systems.

CO spillover on CuO/ZnO p-n heterojunction facilitating the electrochemical reduction of carbon dioxide to ethylene

Huihui Bao,Wenzheng Nie,Yingchun Liu,Linglan Men,Mingzheng Ren,Changlei Xia,Huan Xie

The electrochemical CO 2 reduction (ECO 2 R) driven by the renewable energy represents an effective approach to mitigate atmospheric CO 2 concentration and to achieve carbon neutrality. Zinc (Zn) and its oxides, being among the most abundant metal materials, are frequently employed in the generation of CO by ECO 2 R. Cooper and its oxides have the moderate *CO affinity which enables the C-C coupling reaction to produce the higher value C2+ products. In this work, we have developed the novel CuO/ZnO p-n heterojunction tandem catalyst using a straightforward solvothermal method. By optimizing the content of CuO/ZnO heterojunction, a maximum Faradaic efficiency of 37% for C 2 H 4 can be achieved in a gas diffusion flow cell, which is one of the highest among the Cu-Zn-based catalysts for ECO 2 R. Mechanism investigations illuminate that CuO/ZnO heterojunction interface enhances the adsorption of *CO 2 – intermediates facilitating the formation of *CO intermediates than pristine CuO, meanwhile weakens the adsorption of *H impeding the competitive hydrogen evolution reaction. Therefore, the spillover of CO from ZnO to CuO sites and the electrons rebalance on CuO/ZnO heterojunction interface promote the C-C coupling reaction rates, thus greatly enhances the selectivity for C 2 H 4 .

P(NMe2)3-Mediated Regioselective N-Alkylation of 2-Pyridones via Direct Deoxygenation of α-Keto Esters

Nan Wang,Yuanyuan Huang,You Zi,Mengke Wang,Weichun Huang

A practical and regioselective direct N-alkylation of 2-pyridones is enabled by use of α-keto esters in the P(NMe2)3-mediated deoxygenation process. The reaction proceeds under mild conditions to produce N-alkylated 2-pyridones with high selectivity and generality, and the protocol is shown to be applicable for the scale-up synthesis, which makes it promising for practical applications.

Integrated control of bacterial growth and stress response by (p)ppGpp in Escherichia coli: A seesaw fashion.

Manlu Zhu,Haoyan Mu,Xiongfeng Dai

To thrive in nature, bacteria have to reproduce efficiently under favorable conditions and persist during stress. The global strategy that integrates the growth control and stress response remains to be explored. Here, we find that a moderate induction of (p)ppGpp reduces growth rate but significantly enhances the stress tolerance of E. coli , resulting from a global resource re-allocation from ribosome synthesis to the synthesis of stress-responsive proteins. Strikingly, the activation of stress response by (p)ppGpp is still largely retained in the absence of RpoS. In addition, (p)ppGpp induction could activate the catabolism of alanine and arginine, facilitating the adaption of bacteria to nutrient downshift. Our work demonstrates that the activation of stress response by (p)ppGpp could occur in an RpoS-independent manner and (p)ppGpp enables bacteria to integrate the control of growth and stress response in a seesaw fashion, thus acting as an important global regulator of the bacterial fitness landscape.