查找使用阿拉丁产品的科研文献

Electrochemical recognition for tryptophan enantiomers based on 3, 4, 9, 10-perylenetetracarboxylic acid–chitosan composite film

Mo Zunli,Niu Xiaohui,Gao Huhu,Li Zhenliang,Meng Shujuan,Guo Ruibin

A novel and simple chiral sensing platform had been successfully fabricated by means of amidation reaction between 3, 4, 9, 10-perylenetetracarboxylic acid (PTCA) and chitosan (CS) to form 3, 4, 9, 10-perylenetetracarboxylic acid–chitosan (PTCA–CS) composite film. Since CS has chiral center and PTCA has excellent electrical conductivity, the PTCA–CS composite modified glassy carbon electrode (PTCA–CS/GCE) could be treated as an effective electrochemical chiral sensor and applied for chiral discrimination of tryptophan (Trp) enantiomers theoretically. PTCA–CS composite was characterized by Fourier transform infrared (FTIR) spectroscopy and cyclic voltammetry (CV). When the prepared chiral sensing interface interacted with tryptophan isomers, a higher selectivity was received from D-Trp by differential pulse voltammetry (DPV). It indicated that the PTCA–CS/GCE can be treated as an electrochemical chiral sensor for the discrimination of Trp enantiomers. Further study demonstrated that the peak currents were linearly increased with the increasing percentage of L-Trp of Trp racemic mixture. Furthermore, the enantioselective interaction of the PTCA–CS/GCE was systematically studied by other experimental factors, such as the incubation time and acidity.

Synthesis and optoelectrochemical properties of a magenta-to-transmissive electrochromic polymer based on 3, 4-dioxythiophene

Xiaoming Chen,Qishu Qu

A new magenta-to-transmissive electrochromic polymer, poly(3,4-bis(3-bromopropoxy)thiophene) (PBBrPOT) was synthesized by electrochemical polymerization and its electrochromic properties were characterized in detail. Compared with the representative “large-volume alkyl substituents” strategy, herein we use bromines as the end-capping groups of two propoxyl substituents on the 3- and 4- position of the thiophene ring to introduce more steric repulsion within the polymer chains, and therefore obtain a magenta neutral state of the polymer. The PBBrPOT film shows a set of reasonable electrochromic features, including low driving potentials (−0.1   V and 0.9   V), appropriate transmittance change (38% at 556   nm), but a relatively longer response time in bleaching process ( t 95 = 6.5   s).

Enhanced flotation separation of ilmenite from titanaugite by novel N-hydroxy-3-(4-methoxyphenyl) acrylamide collector

Yao Yu,Zhifeng Zhang,Yijun Cao,Wei Sun,Zhiyong Gao,Haisheng Han,Pan Chen,Jian Cao

To improve the separation of ilmenite from its associated gangue mineral titanaugite through selective flotation, a novel hydroxamic acid derivative, N-hydroxy-3-(4-methoxyphenyl) acrylamide (HMPA), was successfully synthesized and evaluated as an efficient collector. Comparative flotation tests demonstrated that HMPA outperformed conventional sodium oleate, achieving superior separation efficiency with a TiO 2 concentrate grade of 48.95 % and an impressive recovery rate of 76.0 %. To understand the underlying mechanisms, the interactions between HMPA and the mineral surfaces were investigated meticulously by adsorption capacity tests, contact angle analysis, FTIR, and XPS. The results of contact angle and adsorption measurements intuitively revealed that HMPA exhibited significantly greater adsorption capacity on the ilmenite surface compared to titanaugite. FTIR and XPS analyses indicated that HMPA adsorbed strongly onto the ilmenite surface through chelation with reactive Ti and Fe sites. Density functional theory (DFT) calculations further suggested that HMPA could act as a bidentate ligand, forming a stable five-membered chelate structure through interactions with the Ti and Fe active sites on the ilmenite surface. In conclusion, HMPA demonstrated outstanding collecting ability and selectivity, making it a highly promising collector for ilmenite flotation.

A regiosymmetric blue-to-transmissive electrochromic polymer based on 3, 4-ethylenedioxythiophene with bromomethyl pendant groups

Xiaoming Chen,Mingdi Yang,Qishu Qu,Qingchun Zhao,Wensheng Zou

The synthesis and electrochromic properties of a novel regiosymmetric polymer based on 3,4-ethylenedioxythiophene, poly(2,3-bis(bromomethyl)-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT(MeBr) 2 ) were highlighted. The monomer was electrochemically polymerized via repetitive cycling between 0 and 1.8 V in lithium perchlorate (LiClO 4 )–acetonitrile (ACN) electrolytic medium. The corresponding polymer was characterized by FTIR spectra, scanning electron microscopy, cyclic voltammetry , UV–Vis-NIR spectroscopy and colorimetry . It features a reversible redox process and demonstrates a stable blue-to-transmissive electrochromic behavior with very low driving potentials (−0.1 and 0.65 V). Additionally the polymer film exhibits enhanced optical contrast (60% at 669 nm) and improved coloration efficiency (183.1 cm 2 /C at 100% full contrast during bleaching process) which are higher than those of PEDOT, a relatively longer response time compared with PEDOT and reasonable redox stability.

Effects of hydrogen sulfide (H2S) on respiration control of state 3/4 in mitochondria from bovine heart

Y Su,Y Cheng,D Wang,F Zhang,Y Su,Z Li

Secreted phosphoprotein 1 regulates natural compound 3’,4’,5,7-tetrahydroxyflavone to inhibit mast cell-mediated allergic inflammation

Shiling Hu,Jue Wang,Haoyun Bai,Chaohua Feng,Zhenqi Zhou,Zhuoyin Xue,Wen Zhang,Yongjing Zhang,Nan Wang,Langchong He

Background Mast cells (MCs) are important effector cells in anaphylaxis and anaphylactic disease. 3’,4’,5,7-tetrahydroxyflavone (THF) presents in many medicinal plants and exerts a variety of pharmacological effects. In this study, we evaluated the effect of THF on C48/80-induced anaphylaxis and the mechanisms underlying its effects, including the role of secreted phosphoprotein 1 (SPP1), which has not been reported to IgE-independent MC activation.Results THF inhibited C48/80-induced Ca2+ flow and degranulation via the PLCγ/PKC/IP3 pathway in vitro. RNA-seq showed that THF inhibited the expression of SPP1 and downstream molecules. SPP1 is involved in pseudo-anaphylaxis reactions. Silencing SPP1 affects the phosphorylation of AKT and P38. THF suppressed C48/80-induced paw edema, hypothermia and serum histamine, and chemokines release in vivo.Conclusions Our results validated SPP1 is involved in IgE-independent MC activation anaphylactoid reactions. THF inhibited C48/80-mediated anaphylactoid reactions both in vivo and in vitro, suppressed calcium mobilization and inhibited SPP1-related pathways.

Low loss Ba3Ti4Nb4O21 microwave dielectric ceramics through (Mn1/3Nb2/3)4+ ion control engineering for LTCC applications

Xiaohui Wu,Qin Zhang,Fangyi Huang,Xingyu Huo,Fuyu Li,Yulan Jing,Yuanxun Li,Hua Su

In this work, a new low loss Ba 3 Ti 4- x (Mn 1/3 Nb 2/3 ) x Nb 4 O 21 (MN-BTN, 0 ≤  x  ≤ 12 mol%) ceramics configuration was presented through preparing by the solid-state route. The XRD patterns, Rietveld refinement , microstructure, and microwave properties were systematically analyzed. All the fabricated MN-BTN ceramics belonged to the hexagonal structure with a P 6 3 / mcm space group. More specifically, the 6MN-BTN ceramic exhibited a high relative density of ~92.3 %, homogeneous grains distribution with an average size of ~71.95 µm, and several excellent microwave dielectric properties : ε r = 59.67, Q× f = 16,226 GHz, τ f = +103.9 ppm/℃ sintered at 1220 ℃. The incorporation of 1.5  wt % BaCu(B 2 O 5 ) (BCB) compound within the 6MN-BTN ceramic not only effectively reduced the sintering temperature from 1220 ℃ to 950 ℃, but also the excellent microwave dielectric properties were maintained: ε r = 42.33, Q× f = 11,300 GHz, τ f = +24.7 ppm/℃. Interestingly, the 6MN-BTN + 1.5  wt % BCB ceramic showed better chemical compatibility with Ag. The proposed 6MN-BTN + 1.5  wt % BCB ceramic configuration could be regarded as a promising material for LTCC applications.

Cross-Linking of Polyamidoxime Nanofibers by a Hyperbranched Macromolecule for Enhancing [UO2(CO3)3]4– Ion Capture

Zixu Ren,Yu Yu,Dingyang Chen,Minsi Shi,Rui Zhao

Polyamidoxime fibers have been widely studied for uranium extraction from seawater, but improving the amidoxime (AO) group utilization and increasing the selectivity toward uranium remain challenging. Herein, a hyperbranched macromolecular cross-linking strategy was employed to construct hyperbranched polyethylenimine (PEI) among the molecular chains of polyamidoxime nanofibers (PAN/PEI-AO nanofibers). This approach simultaneously suppressed chain entanglement and effectively reduced hydrogen bond formation between amidoxime groups, thereby significantly enhancing the utilization efficiency of AO groups. Moreover, the PEI structure also facilitated the dissociation of CO32– from uranyl tricarbonate ([UO2(CO3)3]4–) and comprised amino groups as assistant groups for enhanced uranium uptake. The above cross-linking effect by PEI was confirmed by experimental data and theoretical calculation, resulting in high uranium uptake (474.8 mg g–1) alongside good deep removal capability (kd = 7.7 × 105 mL g–1) from [UO2(CO3)3]4– solution. Moreover, PAN/PEI-AO nanofibers also exhibited good selectivity and reusability toward uranium and showed a uranium extraction capacity of 8.24 mg g–1 after 20 days’ testing from natural seawater. The obtained adsorption performance of PAN/PEI-AO nanofibers exceeded traditional polyamidoxime nanofibers and many reported uranium adsorbents. Overall, this work offers a strategy to improve the performance of polyamidoxime fibers, which possess the potential to extract real uranium species from natural seawater.

Design, Synthesis and Biological Evaluation of Novel 1, 3, 4-Oxadiazole PD176252 Analogues as Potential GRPR Inhibitors

Zhu Yuting,Wang Huai,Yu Mingjun,Li Chao,Meng Xiaoming,He Meng,Yao Risheng

Background: GRPR is over-expressed in cancer cells and is a potential drug target for the treatment of cancer. PD176252, as the most representative non-peptide inhibitor of GRPR, can inhibit the growth of cancer cells, but its low selectivity to cancer cells and normal cells limits its further application. Objective: The aim of this study was to design and synthesize novel GRPR inhibitor with stronger anti-cancer activity and higher affinity with GRPR than the lead compound PD176252. Methods: A series of 1, 3, 4-oxadiazole derivatives as PD176252 analogues (4a-4j, 6a-6q) were synthesized and their cytotoxic activity was investigated on four cancer lines with high expression of GRPR (gastric (HGC-27), colon (HCT- 116), prostate (PC-3), and lung (A549)) and one human cell line (gastric mucosal epithelial (GES-1)) by MTT assay. Flow cytometry analysis and Western Blot were used to determine whether the compound induced programmed apoptosis of cancer cells. Competitive binding experiment was used to verify the affinity between GRPR and the optimal compound. Results: Compound 6m exhibited significant growth inhibition on all tested cancer cell lines, especially gastric cancer cells (HGC-27 cellular IC50 0.37 ± 0.04μM). Also, the selectivity of 6m to HGC-27 was much higher than that of PD176252. Flow cytometric analysis and Western Blot proved that 6m significantly promoted the apoptosis of HGC- 27 cells. Moreover, competitive binding experiment confirmed the close binding of 6m with GRPR, which indicated 6m with a higher affinity than lead compound PD176252. Conclusion: Our results suggested that 6m, as a novel GRPR inhibitor, had a higher affinity with GRPR and potential anti-cancer effect than PD176252, which can be used as a template for further optimization.

In vitro and In Vivo Drug Metabolism Analysis of BPI-460372 - A Covalent TEAD1/3/4 Inhibitor

Xiaoyun Liu,Dafang Zhong,Chongzhuang Tang,Xiaofeng Xu,Hong Lan,Xingxing Diao

Background BPI-460372 is an orally available, covalent, irreversible small molecule inhibitor of the transcriptional enhanced associate domain (TEAD) 1/3/4, which is currently in clinical development for the treatment of cancers with Hippo pathway alterations. Objectives This study aimed to determine the cytochrome P450 (CYP) phenotyping, metabolic stability, and in vitro and in vivo metabolic profile of BPI-460372. Methods The CYP phenotyping and metabolic stability were assessed by measuring the depletion of substrate. The metabolic profile in hepatocytes and rat and dog plasma was analyzed using ultra-high-performance liquid chromatography combined with Orbitrap tandem mass spectrometry (UHPLC-Orbitrap-HRMS). Results BPI-460372 was mainly metabolized by CYP2D6, CYP3A4, and CYP1A2. BPI-460372 exhibited low clearance in human, monkey, and rat hepatocytes, while moderate clearance in dog and mouse hepatocytes. A total of 10 metabolites were identified in five species of hepatocytes, and no human-unique metabolite was detected. In rat plasma and dog plasma, the primary metabolites were M407 (BPI-460430) and M423 (BPI-460456), respectively. The two metabolites were quantitatively determined in rat and dog plasma in pharmacokinetic and toxicological studies. The major metabolic site was 2-fluoro-acrylamide, and major metabolic pathways in hepatocytes, and rat and dog plasma involved oxidative defluorination, hydration, glutathione (GSH) conjugation, hydrolysis, cysteine conjugation, and N-acetyl cysteine conjugation. β-lyase pathway contributed to the metabolism of BPI-460372 in rats to a certain degree. Conclusion This study elucidated the metabolism of BPI-460372 and provided a basis for pharmacokinetic and toxicological species selection, human pharmacokinetics prediction, and assessment of clinical co-administration limitations and possible metabolic pathways in humans.

Bandgap Engineering for Photocatalytic Polymerization of 3, 4-Ethylenedioxythiophene (EDOT) over Cs3BixSb(2-x)Br9 Inverse Opals

Siwei Zhao,Shaohua Jin,Huanmin Liu,Youxin Su,Wei Liu,Shengfu Li,Chongchong She,Haonan Li,Kun Chen

Graphical A series of all-inorganic lead-free halide perovskite inverse opals were prepared and furtherly used as the photocatalysts to promote the polymerization of EDOT under the irradiation of visible light. All the samples exhibited the nice replica of the artificial template and high crystallinity. The bandgap of the catalysts was adjusted by screening the ratios of bromide to iodide and antinomy to bismuth. Cs 3 Bi 0.5 Sb 1.5 Br 9 showed the highest performance of the photocatalytic polymerization for EDOT, indicating the dual halide perovskites are more flexible than single halide perovskite in terms of bandgap engineering. A series of all-inorganic lead-free halide perovskite inverse opals were prepared and furtherly used as the photocatalysts to promote the polymerization of 3, 4-ethylenedioxythiophene (EDOT) under the irradiation of visible light. All the samples exhibited the nice replica of the artificial template and high crystallinity. The bandgap of the catalysts was adjusted by screening the ratios of bromide to iodide and antinomy to bismuth, respectively. Among all the samples, Cs 3 Bi 0.5 Sb 1.5 Br 9 inverse opal showed the best catalytic performance and the excellent stability in terms of the morphology and the crystalline phase after four cycles of photocatalytic polymerization. Since EDOT is commercially available, the present observation suggested a convenient protocol of preparing the composited materials or optoelectronic devices based on the lead-free halide perovskites and the conductive poly(3, 4-ethylenedioxythiophene).

Integrated flexible supercapacitor based on poly (3, 4-ethylene dioxythiophene) deposited on Au/porous polypropylene film/Au

Na Wang,Gaoyi Han,Hua Song,Yaoming Xiao,Yanping Li,Ying Zhang,Hongfei Wang

Thin layers of continuous gold have been deposited on the both sides of porous polypropylene films (PPF) via electroless plating method to form a sandwich structure with two conductive surfaces and an intermediate insulating layer (Au/PPF/Au). Then poly (3, 4-ethylenedioxy thiophene) (PEDOT) layers are electrodeposited on the two conductive sides via cyclic voltammetry method to form the sandwich-structured PEDOT-Au/PPF/Au-PEDOT. Gel electrolyte of H 3 PO 4 /polyvinyl alcohol (H 3 PO 4 /PVA) is then added to the sandwich-structured PEDOT-Au/PPF/Au-PEDOT to form the integrated flexible supercapacitor of Au-PEDOT|H 3 PO 4 /PVA|PEDOT-Au. The PEDOT-Au/PPF/Au-PEDOT sandwiched structures are characterized and the capacitive performances of the integrated flexible cells are investigated in detail. The results show that the optimum integrated flexible cell exhibits excellent cycling stability (91.8% capacitance retention after 20000 cycles) and relatively high areal specific capacitance. Furthermore, the cells of Au-PEDOT|H 3 PO 4 /PVA|PEDOT-Au not only exhibit excellent bending endurance (99.1% capacitance retention after 5000 repeated bending cycles), but also can be conveniently connected in series without additional wires. This integrated flexible cell may exhibit potential application in portable electronics.