查找使用阿拉丁产品的科研文献

Effects of paeoniflorin-6′-O-benzene sulfonate on the pharmacokinetics, excretion and tissue distribution of leflunomide in rats

Ning Xiao,Feng Xiao,Jinzhang Gao,Zhengkun Xu,Qianlei Wang,Jiajie Kuai,Wei Wei,Chun Wang

Paeoniflorin-6′-O-benzene sulfonate (CP-25) is a novel ester derivative of paeoniflorin, which has been shown to have synergistic pharmacodynamic effects with leflunomide (LEF). To determine the effects of CP-25 on the pharmacokinetics of LEF in rats, we developed a ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based method for the determination of levels of teriflunomide (TER, an active metabolite of LEF). This method was used to determine TER concentrations in the plasma, urine, faeces and bile; heart, liver, spleen, lung, kidney, intestinal, brain and synovial tissues; and peripheral blood mononuclear cells (PBMCs) of rats in the control (LEF [10 mg/kg]) and combined (CP-25 [50 mg/kg × 7d] plus LEF [10 mg/kg]) groups. TER area under the curve [AUC], T max , mean residence time (MRT), t 1/2α and t 1/2β were significantly lower, and clearance (CL) was significantly higher in the combined group than in the control group. Oral CP-25 administration in combination with LEF was found to promote TER excretion in urine, faeces and bile and to reduce its contents in most tissues and organs, especially in the liver, which may reduce LEF-induced liver injury. CP-25 also increased TER exposure in the synovium and its absorption by PBMCs, and this could explain the synergistic effects of CP-25 and LEF.

The flame retardancy of polyamide 6—prepared by in situ polymerisation of ε-caprolactam—For T-RTM applications

Zsófia Kovács,Ákos Pomázi,Andrea Toldy

The complexity of recycling crosslinked polymer composites has promoted the use of thermoplastic in situ polymerisable matrices, including ε-caprolactam-based polyamide 6 (PA6) in long-fibre reinforced composites. Their uptake by the automotive industry has created a need for adequate flame retardancy, which poses several challenges: flame retardants may hinder the in situ polymerisation reaction; moreover, the fibre reinforcement can filter out the additives not soluble in ε-caprolactam during liquid moulding composite processing, such as thermoplastic resin transfer moulding (T-RTM). We discussed the feasibility of the flame retardancy of ε-caprolactam-based PA6 and its composites, including the solubility of the additives in ε-caprolactam and their effect on the polymerisation reaction and fire performance. We evaluated the correlations between the flame retardant structure and the inhibition of polymerisation. Finally, we briefly summarised the composite processing and coating technologies suitable for preparing flame retarded ε-caprolactam-based PA6 matrix and composite systems, as well as the most often used tests for their characterisation.

Fluorescent composite based on peptide nanotubes activating coumarin 6 for sensitive detection of new coccine in food samples

Fang Li,Rong Tang,Yujie Kang,Xiaoyan Cui,Ya Wang,Xiupei Yang

New coccine (NC), as a kind of common colorant, has been frequently used in our daily life. Herein, the fluorescent composite (PNTs@C6) prepared by the hydrophobic non-covalent interaction between peptide nanotubes and coumarin 6 (C6) was designed for the determination of NC. Due to the activation of C6 by peptide nanotubes, the composite exhibits strong green fluorescence emission, which can be selectively quenched by NC through the inner filter effect. Therefore, a new fluorescent method based on the PNTs@C6 composite for NC detection was constructed. Under optimal conditions, the fluorescence quenching of the sensor exhibits a good linear relationship with the concentration of NC in the range of 0.01–10 μM and the limit of detection is 3.6 nM. Furthermore, the strategy shows simplicity, rapid response and high selectivity and has been successfully applied to the detection of NC in food samples.

High-throughput screening of a nicotinate dehydrogenase producing Pseudomonas putida mutant for efficient biosynthesis of 6-hydroxynicotinic acid

Yu-Ting Shang,Jiufu Qin,Jin-Song Gong,Zi-Kai Wang,Heng Li,Hui Li,Jin-Song Shi,Zheng-Hong Xu

A nicotinate dehydrogenase producing strain was isolated and identified to be Pseudomonas putida , which could bio-transform nicotinic acid into 6-hydroxynicotinic acid. The activity of nicotinate dehydrogenase towards nicotinic acid could reach up to 1.11 U/mL and the yield of 6-hydroxynicotinic acid accumulated to 176 g/L within 30 h with a space time yield of 1.36 g/(g•h). In order to further improve its catalytic potential, a mutant library was constructed through atmospheric and room temperature plasma (ARTP) and rapidly screened by a high-throughput screening strategy, which obtained a mutant strain mut-5 with activity of 2.68 U/mL. Via developing a nitrilase-nicotinate dehydrogenase enzymatic cascade system, 54.5 g/L 6-hydroxynicotinic acid could be obtained within 585 min with 3-cyanopyridine as the substrate, which would further reduce the production costs. The results indicated that the nicotinate dehydrogenase (separately or combining with nitrilase) could serve as a superior catalyst for 6-hydroxynicotinic acid production. To our knowledge, the nicotinate dehydrogenase activity reported in this study was the highest level in literature to date.

Solubility Measurement and Model Correlating of 6-Propyl-2-Thiouracil in Four Binary Solvents at 278.15–323.15 K

Wenju Liu,Yanmin Shen,Fankun Zeng,Shuanghui Lu,Jun Li,Jinjin Yang,Kewen Zhang

The solubility of 6-propyl-2-thiouracil was determined in DMF + water, DMF + methanol, DMF + ethanol, and DMF + 1-propanol mixture solvents by a gravimetric method in the temperature range from 278.15 to 323.15 K under atmospheric pressure. The results indicated that the solubility of 6-propyl-2-thiouracil in the (DMF + methanol) mixture is greater than that in (DMF + ethanol), (DMF + 1-propanol), and (DMF + water) at the same DMF composition and temperature, and that the solubility increased with increase in the mass fraction of DMF in mixture solvents. The modified Apelblat model, λh model, Van′t Hoff model, and Jouyban Acree-Apelblat model were employed to correlate well with the solubility of 6-propyl-2-thiouracil in four binary solvents using values of ARD% and RD, and the four models were considered to be the reliable methods for the solubility prediction of 6-propyl-2-thiouracil.

Na3AMg7(PO4)6 (A = K, Rb and Cs): Structures, properties and theoretical studies of alkali metal magnesium orthophosphates

Jiahao Jiao,Wenqi Jin,Min Zhang,Zhihua Yang,Shilie Pan

Adsorption of fulvic acid onto polyamide 6 microplastics: Influencing factors, kinetics modeling, site energy distribution and interaction mechanisms

Shuai Tang,Lujian Lin,Xuesong Wang,Xuan Sun,Anqi Yu

Information on the interactions of microplastics (MPs) with dissolved organic matter (DOM) is essential for understanding their environmental impacts. This study selected fulvic acid (FA) as a typical DOM to investigate the influence of contact time, temperature, dosage, solution pH, salinity , and coexisting metal ions on the adsorption of FA onto polyamide 6 (PA6) MPs. The adsorption kinetic and isotherm can be successfully described by mixed-order (MO) and Freundlich models. The adsorption site energy distribution based on the Freundlich equation was applied to analyze the interaction between FA and PA6-MPs and the adsorption site heterogeneity. Thermodynamic analysis demonstrated that the values of parameters ( Δ G a d s ° , Δ S a d s ° , Δ H a d s ° ) were significantly affected by initial solution concentrations and the adsorption process was spontaneous, endothermic, and randomness-increased. Fourier transform-infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) revealed the importance of amide functional groups of PA6-MPs in controlling FA adsorption. Hydrogen bonds , hydrophobic, electrostatic, and n-π electron donor-acceptor (n-π EDA) interactions played different roles on adsorption of FA under different conditions of solution chemistry. These findings are beneficial to provide new insights involving the adsorption behavior and interaction mechanisms of FA onto PA6-MPs for the environmental risk assessment of MPs.

Synergistic effects of graphene oxide and paraffin wax on the tribological properties of monomer casting nylon-6 composites

Saisai Huang,Bingli Pan,Mengxin Xie,Jiayu Gao,Guangming Zhao,Yumiao Niu,Honggang Wang

In this work, monomer casting nylon-6 (MCPA6)/melamine foam (Me)/graphene oxide (GO)/paraffin wax (PW) composites were synthesized using Me foam as a three-dimensional template and adsorbing GO and PW on the Me foam skeleton. The microstructure and tribological behaviors of the MCPA6/Me/GO/PW composites were determined and the interaction of PW with GO were theoretical investigated. The results showed that the addition of both GO and PW significantly improved the tribological properties of the composites. Compared with pure MCPA6, the friction coefficient and specific wear rate of the composite with the ratio of 2:3.5 (GO to PW) were reduced by 82% and 84%, respectively. The improvement of tribological performance was attributed to the synergistic lubrication and anti-wear effects of PW and GO.

IL-6-targeted ultrasmall superparamagnetic iron oxide nanoparticles for optimized MRI detection of atherosclerotic vulnerable plaques in rabbits

Huaqiang Mo,Chenxing Fu,Zhiye Wu,Peng Liu,Zhibo Wen,Qingqing Hong,Yanbin Cai,Gongxin Li

Vulnerable plaques of atherosclerosis (AS) are the main culprit lesion for the serious risk of acute cardiovascular disease (CVD). Therefore, developing new non-invasive methods to detect vulnerable plaques and to evaluate their stability effectively is of great value in the early diagnosis of CVD. IL-6 plays a vital role in the development and rupture of AS. In this study, IL-6-targeted superparamagnetic iron oxide nanoparticles (Anti-IL-6-USPIO) are synthesized by a chemical condensation reaction. An AS model was established by damaging rabbit abdominal aortic intima with Foley's tube in combination with a high cholesterol diet. The results confirm that Anti-IL-6-USPIO have excellent IL-6-targeting ability and usefulness in detecting vulnerable plaques in vitro and in vivo, which may provide a novel, non-invasive strategy for evaluating acute cardiovascular risk or exploiting anti-atherosclerotic drugs.

New insight into the joint significance of dietary jujube polysaccharides and 6-gingerol in antioxidant and antitumor activities

Zhen Wu,Ruiping Gao,Hong Li,Yongde Wang,Yang Luo,Jiang Zou,Bo Zhao,Shiqi Chen

The combinatorial use of dietary jujube (Ziziphus jujuba) and ginger play a critical role in traditional Chinese medicines, folk medicine and dietary therapy. Joint effects were investigated from the viewpoint of the antioxidant (scavenging DPPH˙) and antitumor activities (against SW620 cells) of jujube polysaccharides and ginger 6-gingerol (G6G) alone and in combination. Jujube polysaccharides were extracted, purified, and characterized, and then their inhibiting and apoptotic effects alone and in combination with G6G were evaluated by the cytological tests, including Cell Counting Kit-8, colony-forming, Annexin V-FITC and propidium iodide, TdT-mediated dUTP nick end labeling (TUNEL) staining, and cell cycle assays. Results showed that the purified polysaccharide fraction (ZJPs-II) with average molecular weight of 115 kDa consisted of arabinose, rhamnose, glucose, xylose, and galactose. ZJPs-II and G6G alone dose-dependently scavenged DPPH˙ and inhibited the proliferation of SW620 cells, while their combination showed synergistic interactions (all combination index < 1). The studies further demonstrated that ZJPs-II and G6G alone reduced the cell colony-formation, induced apoptosis and arrested the cell-cycle at G2/M phase, while their combination achieved better effects and significantly arrested the growth at the G0/G1 phase. Collectively, our findings suggest enhancing the intake of jujube polysaccharides and G6G in a combinatorial approach for maintaining health and preventing cancer.

Synthesis of (Sn,Zn)(O,S) bimetallic oxysulfide catalyst for the detoxification of Cr+6 in aqueous solution

Osman Ahmed Zelekew,Dong-Hau Kuo,Hairus Abdullah

Herein, we report the bimetallic (Sn,Zn)(O,S) oxysulfide nanocatalyst with a facile method. The Sn-based catalyst with the addition of Zn was synthesized with the proportions of 0, 20, 30 and 50% of Zn to Sn precursors for preparation. The catalysts were characterized by XRD , TEM , SEM XPS , and UV–vis instruments. The nanocatalysts were also tested for the detoxification of Cr +6 . The Sn-20 catalyst with 20 M percent of Zn(Ac) 2 ·2H 2 O showed an excellent performance for the induced photocatalytic reduction of Cr +6 under visible light irradiation at room temperature. The complete reduction of Cr +6 was achieved within 80 min by Sn-20 catalyst. However, 85.6, 97, and 94% of Cr +6 reductions were achieved within 80 min under visible light illumination by Sn-0, Sn-30, and Sn-50 catalysts, respectively. Hence, the bimetallic (Sn,Zn)(O,S) oxysulfide nanocatalyst will be a candidate and highly potential material for the detoxification of Cr(VI)-containing polluted water.

Nrf2 deficiency aggravates Angiotensin II-induced cardiac injury by increasing hypertrophy and enhancing IL-6/STAT3-dependent inflammation

Dandan Chen,Zhe Li,Peiqing Bao,Miao Chen,Miao Zhang,Fangrong Yan,Yitao Xu,Caoyu Ji,Xinyue Hu,Daniel Sanchis,Yubin Zhang,Junmei Ye

Background NF-E2-related factor 2 (Nrf2) is a transcription factor playing cytoprotective effects in various pathological processes including oxidative stress and cardiac hypertrophy. Despite being a potential therapeutic target to treat several cardiomyopathies, the signaling underlying Nrf2-dependent cardioprotective action remains largely uncharacterized. Aim This study aimed to explore the signaling mediating the role of Nrf2 in the development of hypertensive cardiac pathogenesis by analyzing the response to Angiotensin II (Ang II) in the presence or absence of Nrf2 expression, both in vivo and in vitro. Results Our results indicated that Nrf2 deficiency exacerbated cardiac damage triggered by Ang II infusion. Mechanistically, our study shows that Ang II-triggered hypertrophy and inflammation is exacerbated in the absence of Nrf2 expression and points to the involvement of the IL-6/STAT3 signaling pathway in this event. Indeed, our results show that IL-6 abundance triggered by Ang II is increased in the absence of Nrf2 and demonstrate the requirement of IL-6 in STAT3 activation and cardiac inflammation induced by Ang II. Conclusion Our results show that Nrf2 is important for the protection of the heart against Ang II-induced cardiac hypertrophy and inflammation by mechanisms involving the regulation of IL-6/STAT3-dependent signaling.