NF-E2-related factor 2 (Nrf2), the key transcription regulator of phase II enzymes, has been considered beneficial for neuronal protection. We previously designed a novel chalcone analog, 1-(2,3,4-trimethoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-acrylketone (Tak), that could specifically activate Nrf2 in vitro. Here, we report that Tak confers significant hippocampal neuronal protection both in vitro and in vivo. Treatment with Tak has no significant toxicity on cultured neuronal cells. Instead, Tak increases cellular ATP production by increasing mitochondrial function and decreases the levels of reactive oxygen species by activating Nrf2-mediated phase II enzyme expression. Tak pretreatment prevents glutamate-induced excitotoxic neuronal death accompanied by suppressed mitochondrial respiration, increased superoxide production, and activation of apoptosis. Further investigation indicates that the protective effect of Tak is mediated by the Akt signaling pathway. Meanwhile, Tak administration in mice can sufficiently abrogate scopolamine-induced cognitive impairment via decreasing hippocampal oxidative stress. In addition, consistent benefits are also observed in an energy stress mouse model under a high-fat diet, as the administration of Tak remarkably increases Akt signaling-mediated antioxidative enzyme expression and prevents hippocampal neuronal apoptosis without significant effect on the mouse metabolic status. Overall, our study demonstrates that Tak protects cognitive function by Akt-mediated Nrf2 activation to maintain redox status both vivo and in vitro, suggesting that Tak is a promising pharmacological candidate for the treatment of oxidative neuronal diseases.

Piperine amino acid derivatives containing phenolic hydroxyl groups were synthesized using piperine as the raw material by amide hydrolysis, amidation, ester hydrolysis, and deacetalization. The obtained products were characterized by mass spectrometry and nuclear magnetic resonance. The antioxidant activity of the piperine derivatives was evaluated by the DPPH and ABTS scavenging rates and the total antioxidant capacity. The results showed that the piperine amino acid (4a–4d) had relatively weak radical-scavenging ability, while the piperine amino acid derivatives (5a–5d) containing phenolic hydroxyl groups had significant radical-scavenging effects. In addition, the total reducing ability of 5a–5d was better than that of piperine. The study also found that piperine derivatives containing phenolic hydroxyl groups played an important role in inhibiting oxidative damage in DNA and erythrocytes.

Piperine was used in this study in its raw form, and different steps, such as amide hydrolysis and amidation, were used to synthesize piperine derivatives containing a phenolic hydroxyl group. DPPH and ABTS free radical scavenging assays were used to assess piperine derivative antioxidant activities. We constructed an AAPH oxidative stress erythrocyte model to study the effect of piperine derivatives on the hemolysis rate of oxidatively damaged erythrocytes as well as the hemoglobin oxidation rate. This AAPH model was also used to determine piperine derivative effects on antioxidant enzyme activity and malondialdehyde (MDA) content. Results showed that spectroscopic methods could synthesize and identify piperine derivatives containing phenolic hydroxyl groups (H-1∼H-3). Moreover, DPPH and ABTS assay results showed that piperine derivative free radical clearance rates were higher compared with the parent compound. Additionally, piperine derivatives (H-1∼H-3) were found to provide protection to AAPH oxidatively damaged erythrocytes in their ability to inhibit AAPH-induced erythrocyte lysis, while hemoglobin oxidation was higher compared with the parent compound. Piperine derivatives may protect intracellular glutathione peroxidase (GSH-Px) antioxidant enzyme system activities, safeguarding against oxidative damage. This study synthesized novel piperine derivatives for use as potential antioxidant agent candidates.

Oxidative stress-induced degeneration of retinal pigment epithelial (RPE) cells is known to be a key contributor to the development of age-related macular degeneration (AMD). Activation of the nuclear factor-(erythroid-derived 2)-related factor-2 (Nrf2)-mediated cellular defense system is believed to be a valid therapeutic approach. In the present study, we designed and synthesized a novel chalcone analogue, 1-(2,3,4-trimethoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-acrylketone (Tak), as a Nrf2 activator. The potency of Tak was measured in RPE cells by the induction of the Nrf2-dependent antioxidant genes HO-1, NQO-1, GCLc, and GCLm, which were regulated through the Erk pathway. We also showed that Tak could protect RPE cells against oxidative stress-induced cell death and mitochondrial dysfunction. Furthermore, by modifying the α, β unsaturated carbonyl entity in Tak, we showed that the induction of antioxidant genes was abolished, indicating that this unique feature in Tak was responsible for the Nrf2 activation. These results suggest that Tak is a potential candidate for clinical application against AMD.

Background: Phase II enzymes are antioxidative enzymes that are regulated by the key transcription factor Nrf2, and activated Nrf2 has been considered beneficial for neuronal protection. Methods: We synthesized a novel synthetic chalcone analog, 1-(2,3,4-trimethoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-acrylketone (Tak), and evaluated its hippocampal neuronal protection in both in vitro glutamate toxicity model and in vivo high fat-diet (HFD) associated neuronal disorders.Findings: We found that treatment with Tak has no significant toxicity on cultured neuronal cells. Instead, Tak increases cellular ATP production by increasing mitochondrial function and decreases ROS levels by increasing phase II enzyme expression. Tak pretreatment prevents glutamate-induced excitotoxic neuronal death accompanied by suppressed mitochondrial respiration, increased superoxide production, and activation of apoptosis. Further investigation showed that the protective effect of Tak is mediated by the Akt/Erk signaling pathway. In addition, an energy stress animal model showed that HFD induces metabolic disorders in mice and suppresses Akt/Erk signaling and mitochondrial activity in the hippocampus. Administration of Tak had no significant effects on the mouse metabolic status but sufficiently increased Akt/Erk signaling-mediated antioxidative enzyme expression and prevented hippocampal neuronal apoptosis.Interpretation: Our study demonstrated that Tak exerts neuronal protection via Akt/Erk signaling in vivo and in vitro, suggesting a promising pharmacological candidate for the treatment of neuronal diseases.Funding Statement: This work was supported by the National Basic Research Program (2015CB553602), the National Natural Science Foundation of China (81571050, 31770917, 31570777, 91649106, and 31701025), the General Financial Grant from the China Postdoctoral Science Foundation (2017M613108) and the Fundamental Research Funds for the Central Universities (Z201806073).Declaration of Interests: The authors declare no competing financial interests.Ethics Approval Statement: Animal procedures were approved by the Xi’an Jiaotong University Animal Care and Use Committee.

以脂肪族树脂K126和3-乙基-3-羟甲基氧杂环丁烷为主要原料,加入光引发剂三苯基硫鎓六氟磷酸盐配制成阳离子光固化体系.通过固化前后红外谱图的对比表明光引发剂三苯基硫鎓六氟磷酸盐在紫外光的照射下可有效的引发脂肪族环氧化合物的光聚合,并且对体系的固化时间,黏度,固化速度,体积收缩率等进行了测试,重点研究了光固化树脂以及稀释剂含量对体系收缩率的影响,配制出了性能优异、黏度低且收缩率低的配方.同时向体系中加入纳米二氧化硅进行配方实验,通过SEM,TEM对其分散性进行表征,证明了加入纳米二氧化硅可有效地降低体系的收缩率并且提升复合材料的力学性能.

A novel tetra-armed D-A type small molecule 4BTF-DTPA-T was designed here by utilizing the thiophene connected ditriphenylamine (DTPA) core and fluorinated benzothiadiazole (BTF) arms. To make a better comparison, tri-armed (star-shaped) 3BTF-TPA was also synthesized. Although a similar absorption spectra covering from 300 to 600 nm was observed for 3BTF-TPA and 4BTF-DTPA-T, much higher extinction coefficient was achieved for tetra-armed 4BTF-DTPA-T in both solution and thin films. Bulk hetero-junction (BHJ) organic solar cells were also fabricated to investigate their photovoltaic performance and as anticipated, a moderate PCE value of 2.61% with a V-oc of 1.00 eV was observed in 3BTF-TPA-based solar cells. However, when the tetra-armed 4BTF-DTPA-T was employed as the electron-donors, much enhanced J(EC) and FF values up to 9.33 mA/cm(2) and 44.80% were achieved for its homogeneous morphology in solar cells, finally leading to the maximum PCE value of 3.68%, indicating that the tetra-armed small molecules could be the promising electron-donors for solution processed organic solar cells.

In this paper, we have developed a series of rare earth fluoride nanocrystals (NCs) that can be used for multi modal imaging applications. Three highly monodisperse and water dispersible NaGdF4:Yb,Ln@NaGdF4 (Ln = Er, Tm, Ho) upconversion luminescence (UCL) NCs with an average size of 75 nm were prepared using a facile and efficient microwave assisted solvothermal reaction in ethylene glycol (EG). The morphology, crystal structures, size distributions and zeta potentials of the resulting NCs were fully characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Nano-ZS90 Zetasizer. The obtained NaGdF4:Yb,Ln@ NaGdF4 (Ln = Er, Tm, Ho) NCs could emit bright blue, green and red luminescence in water upon laser excitation at 980 nm. Furthermore, these core shell NCs exhibited low cytotoxicity for HeLa and C9H2 cells, separately. Moreover, these NCs also displayed excellent Hounsfield units (HU) values in X-ray computed tomography (CT) imaging and high relaxivity parameters (r(1)) in magnetic resonance (MR) imaging in vitro. Thus, these small, water dispersible and biocompatible NCs show excellent potential as contrast agents for UCL/CT/ MR multimodal imaging and other biomedical applications.

To release the steric-strain in largely fused molecular backbone and achieve the much planar molecules for efficient organic solar cells, a facile method was proposed by dividing the rigidly fused dibenzo-sexithiophene (DBST) units in FT3 with large molecular skeletons to two smaller building blocks to construct the electron donor-acceptor type compound FT4. As observed, much improved molecular co-planarity was achieved for FT4 in contrast to that of FT3, then leading to the higher charge carrier mobilities up to 6.7 x 10(-4) cm(2)V(-1)s(-1) by SCLC method. Meanwhile, FT4-based BHJ solar cells also exhibited much enhanced photovoltaic performance with the maximum PCE value of 3.07% and higher Jsc value of 8.23 mA/cm(2), which is only 2.13% and 5.67 mA/cm(2) for FT3-based solar cells. The results here indicated that the strain-released method, especially in the highly fused molecules, is beneficial to further improve their co-planarity, then leading to the high charge carrier mobilities and much enhanced photovoltaic performance in solar cells. (C) 2017 Elsevier Ltd. All rights reserved.

In order to reduce the use of organic solvents in manufacturing and construction, new type of resin was prepared from the polyethylene glycol -600 (PEG-600) and bisphenol-A epoxy resin through two steps. This new resin was characterized by infrared spectroscopy. This new non-ionic resin without charge has good stability.

The invention relates to a method for simulating peroxidase by manganese dioxide nanosheet for detection of reductive biological molecules. The peroxidase simulated by manganese dioxide nanosheet can perform catalytic oxidation on substrates of 3,3',5,5'-tetramethyl benzidine TMB, 2,2-azino-di(3-ethyl-benzothiazoles-6-sulfonic acid) diammonium salt ABTS and o-phenylenediamine OPD, and changes the color from colorless to blue, green and orange respectively, at the same time, the manganese dioxide nanosheet can sensitively and selectively perform an oxidation reduction reaction with reductive biological molecules such as glutathione and ascorbic acid, oxidation product concentration of the substrates such as TMB, ABTS and OPD is changed, and then, the reductive biological molecules such as glutathione and ascorbic acid are subjected to quantitative determination through a colorimetric analysis method. The method has the characteristics of simple operation, high sensitivity, good reappearance and high selectivity; a detection linear scope of glutathione is 1-15 [mu]M, the detection limit is 0.3 [mu]M; the detection linear scope of ascorbic acid is 3-100 [mu]M, the detection limit is 0.8 [mu]M; and the method can be used for detecting various phenolic compounds.

本文以环氧丙烯酸树脂(EA)、甲苯二异氰酸酯(TDI)和聚乙二醇单甲醚750 (MPEG750)为原料,合成了水性自乳化单组分热固化树脂.讨论了固化温度、引发剂含量对涂膜固化时间的影响,研究了环氧丙烯酸树脂和季戊四醇三丙烯酸酯(PET3A)的含量对涂膜铅笔硬度、附着力、耐酸碱性和耐水性能的影响,同时也研究了涂膜的耐热性能及树脂的贮存稳定性.实验表明:当固化温度为200℃、引发剂含量为3％、预聚体中环氧丙烯酸树脂和季戊四醇三丙烯酸酯的含量分别为22.5％和2.5％时,制得的热固化树脂性能良好,树脂贮存稳定性较好,使用非常方便.

线粒体功能异常和外界刺激引起细胞内活性氧(reactive oxygen species，ROS)含量的长期增高会对脂质体、蛋白和DNA造成损伤，可能诱发癌症、心血管疾病、风湿性关节炎和各种神经性疾病等。日常食用和药用的植物中含有的维生素、胡萝卜素和多酚类化合物等种类众多的抗氧化剂能帮助清除过量ROS，是近年来食品化学、药学和生命科学等领域的一个研究热点。本文主要从化学角度介绍常见天然抗氧化剂的结构和抗氧化机理，重点是从化学检测实验、细胞实验和动物实验三个层面综述抗氧化性能的检测方法和化学反应机理。试图帮助读者正确理解抗氧化反应的化学本质，有助于合理组合使用抗氧化检测方法获得可靠的评价结果。最后对天然抗氧化剂研究中存在的主要问题以及未来的热点方向进行了分析和展望。 Excess reactive oxygen species (ROS) caused by mitochondrial dysfunction and adverse external stimulus would damage the liposomes, proteins, even DNA in cells, which is one of the lead causes for cancer, cardiovascular disease, rheumatoid arthritis and a variety of neurological diseases. The most important natural antioxidants are the vitamins, carotenes and polyphenol compounds in daily consumption and medicinal plants. These antioxidants can eliminate the ROS effectively and have become a research hotspot recently. This article reviews the structures and antioxidation mechanisms of these important natural antioxidants from a chemical perspective, and focuses on the available test methods of the toxicity and antioxidant properties at three levels, i.e. chemical test, cell experiments and animal experiments, respectively. We believe that this article may help the readers to understand correctly the chemical nature of the antioxidants’ antioxidation, and guide researches to choose proper test methodologies to obtain reliable evaluation results. Finally, some future opportunities and challenges in the antioxidant field are discussed to our un-derstanding.

The near-infrared (NIR) fluorescence imaging technologies have attracted considerable interest in recent years. They take great advantages for in vivo bioimaging because of their deep tissue penetration, minimum photo-damage to biological samples, and minimum interference from background auto-fluorescence by biomolecules in the living systems. It is still a crucial issue to develop NIR fluorescent dyes with high efficiency and low toxicity for fluorescence bioimaging technology. This article reviews the advances in the development of organic NIR fluorescent dyes including cyanines, BODIPYs, rhodamine analogues, squaraines, porphyrins; and the relationship between the structure and optical properties is highlighted to guide the design and preparation of NIR fluorescent dyes. In addition, We focus on discussing the main methodologies of functional modification to improve the biocompatibility and targeting capacities of organic NIR fluorescent dyes to realize multifunction and high performance. Finally, the future opportunities and challenges of NIR fluorescent dyes and NIR fluorescence imaging technologies are addressed to our understanding.

Optical fiber smart composites can be used to continuously monitor internal stress and damage of composite materials with good stability and reliability. However,these optical fibers are embedded manually at present,which results in low efficiency and poor consistency. Aiming at this problem,a high-efficiency automotive placement of optical-fiber smart composites manufacturing method is proposed and investigated in this paper. The parameters of conveying roller material,convey pressure,laying pressure and heating temperature are determined by the designed automotive placement. Optimized results indicate that small optical-fiber loss and a stable opticalfiber grating reflection spectrum can be obtained when the optical fiber is placed parallelly to carbon fiber with silicone rubber convey roller,the convey pressure of 15 N and the laying pressure of 300 N at 80 ℃,which can ensure the sensing performance of the optical fiber grating.

NdF3 nanoflakes and hexagonal NaNdF4 nanorods were successfully prepared in a facile manner by the one-pot microwave-assisted hydrothermal reaction of Nd(NO3)(3)center dot 6H(2)O and NaF within 3 h at pH = 1 and pH = 3-10, respectively. Ethylenediaminetetraacetic acid disodium salt (C10H14N2O8Na2 center dot 2H(2)O, EDTA-2Na) was used as the morphology-controlling agent. The size, morphology, and crystallinity of the resulting nanocrystals can be easily tuned by adjusting the reaction temperature and time. The as-prepared NdF3 nanoflakes and NaNdF4 hexagonal prisms were characterized by X-ray diffraction and scanning electron microscope. All nanocrystals exhibited a typical hexagonal phase, and their crystallization improved with increasing reaction temperature and reaction time. A strong emission spectrum was observed at approximately 850-900, 1060, and 1330 nm for both NdF3 nanoflakes and NaNdF4 nanorods under a laser excitation of 354 nm, indicating that Nd3+ exhibits high luminescence in these two nanocrystals. (C) 2015 Elsevier B.V. All rights reserved.

Fe3O4 nanomaterials have attracted tremendous attention in the field of magnetic resonance imaging (MRI) because of their low cost, good biocompatibility, favorable superparamagnetic properties. This article focuses on the controlled preparation methods of superparamagnetic Fe3O4 nanoparticles, and provides an in-depth discussion of the key factors and their influence rules for particle size, crystallinity and magnetic properties. The current status of available methodologies and mechanisms for the assembly and surface modification of Fe3O4 nanoparticles are highlighted to generate high performance and multifunction. We also systematically summarize the effect of particle size, morphology and surface properties on the magnetic and toxic properties of Fe3O4 nanoparticles. Finally, the future opportunities and challenges of Fe3O4 nanomaterials used as MRI contrast agents are addressed to our understanding.

An important problem for traditional nanoimprint resin is that they are difficult to completely fill the micro- and nanocavity. To address this issue, an ionic liquid-type acrylate compound(termed as I-M-PET3A) was synthesized and used to prepare nanoimprint resin with N,N-dimethyl ethanolamine as coinitiator, benzophenone as photosensitizers and hydroxypropyl acrylate as reactive diluents. The nanoimprint resin have a relatively low viscosity(530 mpa·s) and good conductivity(33.98μs·cm-1), therefore exhibiting excellent electrowetting properties. It can totally fill the 30μm×120μm microgrooves in 10 s under a square wave alternating current(200V, 10Hz). And terrific micropatterns could be obtained after being light-cured and demoulded. This nanoimprint resin with both light-cured and electrowetting properties provide a new way to develop high- performance nanoimprint resin.

The core–shell polysiloxane/fluoroacrylate copolymer latexes p(D4/D4V)/p(BA/MMA/FA) are prepared for coating materials. P(D4/D4V) core is synthesized by ring-opening polymerization of octamethylcyclotetrasiloxane (Si4O4(CH3)8, D4) and tetravinyltetramethylcyclotetrasiloxane (Si4O4(CH3)4(C2H3)4, D4V). P(BA/MMA/FA) shell is obtained by semi-continuous seed emulsion copolymerization of methyl methylacrylate (MMA), butyl acrylate (BA) and fluorinated acrylate (FA) via. Four different FA are used in this paper: hexafluorobutyl acrylate (6FA), trifluoroethyl methacrylate (3FMA), hexafluorobutyl methacrylate (6FMA) and dodecafluoroheptyl methacrylate (12FMA). The as-prepared latexes are characterized by Fourier transforms infrared (FT-IR) spectroscopy and 1H NMR measurement. The typical core–shell structure is proved by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The effect of different shells on the core–shell particles and the surface properties of films are characterized by TEM, dynamic light scattering (DLS), scanning electron microscope coupled with the energy dispersive spectrometry (SEM-EDX), static contact angles (SCA) for surface free energy, and quartz crystal microbalance with dissipation (QCM-D) monitoring for surface water absorption. With the increase of fluoridated side chain in the shell, the individual core–shell particles as 70–90nm are obtained. The surface free energy for p(D4/D4V)/p(BA/MMA/12FMA) film (19mN/m) is much lower than other three films (28–29mN/m). During the film formation, the self-aggregation of CF3 groups onto the film surface for lower surface free energy and the polysiloxane groups onto the substrate for better adhesion. Therefore, p(D4/D4V)/p(BA/MMA/12FMA) film is much more homogeneous, less wettability and less water absorption.

经两步反应合成了二苯甲烷型双马树脂(BDM)的改性剂二(2-氯代-3-羟丙基醚)二烯丙基双酚A,测定了产物粘度并以红外光谱和核磁谱图对其结构进行了表征.通过环氧值和产率测定研究了催化剂对反应的影响,结果表明,第一步反应中可以NaOH颗粒为催化剂和缚酸剂,第二步反应中缩水甘油醚化二烯丙基双酚A可在稀盐酸条件下进行开环反应.加入该改性剂后,BDM在环氧树脂中的添加质量分数可达到30％以上.