查找使用阿拉丁产品的科研文献

Nickel nanoparticles embedded in N-doped carbon efficient selective hydrogenation of cinnamaldehyde in aqueous phase

Xingguo Yang,Xinhuan Lu,Qinjun Zhang,Hao Liu,Haotian Guo,Lin Zhao,Dan Zhou,Qinghua Xia

The selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) is challenging because the hydrogenation of C = C bonds is thermodynamically favored over that of the C = O group. In this work, Ni 3 /Fe@CN-x materials prepared by loading metal Ni onto carbon materials derived from Fe-ZIF were successfully used to selectively hydrogenate the C = O bond of cinnamaldehyde, while single metal Ni@CN-x materials derived from Ni-ZIF materials were successfully used to selectively hydrogenate the C = C bond in the side chain of CAL. Both catalysts shows admirable catalytic activity in the selective hydrogenation reaction of CAL. The reaction results show that the introduction of Ni species into Fe@CN-350 material significantly improved the conversion of CAL and the selectivity of COL, which is attributed to the synergistic effect of bimetallic Ni and Fe, and the excellent hydrogenation activity of metallic Ni. The Ni 3 /Fe@CN-350 catalytic system can achieved 94.3 % CAL conversion and 86.3 % COL selectivity, and the catalyst could be stably recycled 5 times. Under mild conditions (90 °C, 4 h), the single metal Ni@CN-600 catalytic system achieved 100 % CAL conversion and >99 % hydrocinnamaldehyde (HCAL) selectivity, and the catalyst could be stably recycled 10 times.

Synthesis and evaluation of antitumour activity in vitro and in vivo of chrysin salicylate derivatives

Xiangping Deng,Zihao Zhao,Shujuan Xiong,Runde Xiong,Juan Liu,Zhe Wang,Liu Zou,Xiaoyong Lei,Xuan Cao,Zhizhong Xie,Yanming Chen,Xing Zheng,Yunmei Liu,Guotao Tang

Development of Glass-sealed Gold Nanoelectrodes for in vivo Detection of Dopamine in Rat Brain

Shushu Ding,Yingzi Liu,Chunrong Ma,Junqi Zhang,Anwei Zhu,Guoyue Shi

In vivo monitoring of dopamine (DA) in cerebral nervous system with no traumatic brain injury is still a challenging work for reliably evaluating the role that DA plays in physical and cognitive functionality. In this work, to reduce the traumatic injury on the brain tissue, we develop a glass-sealed Au nanoelectrode (GSNE) with nanoscale physical dimention for cerebral DA detection. First, an Au microwire was sealed into the pre-thinned silica capillary. Then, the obtained Au/capillary assembly was pulled into two tips followed by polishing away the excess glass to expose the Au nanotip. The morphology of GSNE was characterized by scanning electron microscopy and transmission electron microscopy. The results showed that this nanoelectrode can be quickly fabricated with high reproducibility. By further electrodepositing cluster-like gold nanostructure on GSNE and modifying Nafion, amperometric detection of DA with high sensitivity and good selectivity were achieved on the Nafion-modified Au/GSNE. Moreover, the Nafion-modified Au/GSNE possessed advantages of easy tissue insertion and minimum tissue disturbance. Thus, the developed electrochemical nanosensor was successfully used for amperometrically monitoring DA level in the striatum of anesthetic rats.

In vitro and in vivo evaluation of didymin cyclodextrin inclusion complexes: characterization and chemosensitization activity

Qing Yao,Meng-Ting Lin,Qing-Hua Lan,Zhi-Wei Huang,Ya-Wen Zheng,Xue Jiang,Yin-Di Zhu,Longfa Kou,He-Lin Xu,Ying-Zheng Zhao

Differential in vivo hemocyte responses to nano titanium dioxide in mussels: Effects of particle size

Ting Wang,Xizhi Huang,Xiaoyu Jiang,Menghong Hu,Wei Huang,Youji Wang

Titanium dioxide nanoparticles (TiO 2 NPs) are widely used in various products and inevitably released with different sizes and forms into aquatic environment. The purpose of this study was to assess the differential immune toxicity of TiO 2 NPs with size difference on mussel hemocytes using flow cytometry (FCM) assays. Hemocyte parameters, including total hemocyte count (THC), hemocyte mortality (HM), phagocytosis activity (PA), lysosomal content (LC), esterase activity (EA), mitochondrial number (MN), mitochondrial membrane potential (MMP) and reactive oxygen species content (ROS) were evaluated in the mussels Mytilus coruscus exposed to two types of TiO 2 NPs (25nm & 100nm: 0.1, 1, 10 mg/L, respectively). In general, size- and concentration-dependent toxicity was pronounced with 25nm-NP and highest concentration (10mg/L) being the most toxic. Alhough a slight recovery from the TiO 2 exposure was observed, significant carry-over effects were still detected. These results highlight the importance of differential size effects of metal oxide NPs on toxicity mechanisms in aquatic animals.

Glutathione S-Transferase Genes are Involved in Lambda-Cyhalothrin Resistance in Cydia pomonella via Sequestration

Chao Hu,Ji-Yuan Liu,Wei Wang,David Mota-Sanchez,Shun He,Yu Shi,Xue-Qing Yang

Pest management is mostly accomplished by the use of insecticides. However, the overuse of insecticides has led to the development of resistance. Glutathione S-transferases (GSTs) are vital detoxification enzymes involved in insecticide resistance in insects. In this study, we report the involvement of GSTs in insecticide resistance to lambda-cyhalothrin in Cydia pomonella, a globally quarantined fruit pest. A total of 25 GST, including 22 cytosolic genes and 3 microsomal genes, are identified from the genome database of C. pomonella. These cytosolic genes are further classified into six classes, including four in delta, eight in epsilon, three in omega, three in sigma, one in theta, and one in zeta class, as well as two unclassified genes. The real-time quantitative polymerase chain reaction (RT-qPCR) shows that the majority of these genes are mainly expressed throughout the larval stage and in the midgut of the fourth-instar larvae. Exposure to an LD10 dose of lambda-cyhalothrin resulted in the upregulation of 17 GST genes. Moreover, mRNA levels of most GST genes, with the exception of CpGSTe6, CpGSTd2, CpGSTd4, and CpGSTz1, are considerably higher in a lambda-cyhalothrin-resistant population (ZW_R) than those of susceptible strains. Recombinant CpGSTd1, CpGSTd3, CpGSTe3, and CpGSTs2 can bind and metabolize lambda-cyhalothrin, with the highest metabolic rate observed for CpGSTd3 but no metabolite(s) was detected, supporting the role of GSTs in sequestration of lambda-cyhalothrin. Molecular dynamics simulation analysis indicates that key residues of hydrophobic pocket-derived lipophilic energy S(lipo) interactions with a hydrophobic pharmacophore of lambda-cyhalothrin are crucial for metabolism by CpGSTd3 and further lead to resistance. Our study is the first to experimentally confirm the involvement of GSTs in lambda-cyhalothrin resistance via sequestration and provides new insights into resistance management in C. pomonella.

Ligustrazine Phosphate Ethosomes for Treatment of Alzheimer’s Disease, In Vitro and in Animal Model Studies

Shi Jun,Wang Yiming,Luo Guoan

In the present study, we have investigated transdermal administration of ligustrazine phosphate (LP), as an antioxidant, for the treatment of Alzheimer’s disease (AD). The LP transdermal ethosomal system was designed and characterized. Franz-type diffusion cells and confocal laser scanning microscopy were used for the in vitro permeation studies. Furthermore, the effect of LP transdermal ethosomal system on AD was evaluated in the scopolamine-induced amnesia rats by evaluating the behavioral performance in the Morris water maze test. The activities of the antioxidant enzymes and the levels of the lipid peroxidation product malondialdehyde (MDA) in the brain of rats were also determined. The results showed that both the penetration ability and the drug deposition in skin of the LP ethosomal system were significantly higher than the aqueous one. The LP transdermal ethosomal system could recover the activities of the antioxidant enzymes and the levels of MDA in the brain of the amnesic rats to the similar status of the normal rats, which was also indirectly reflected by the improvement in the behavioral performance. In conclusion, LP might offer a potential alternative therapeutic drug in the fight against AD, and ethosomes could be vesicles of choice for transdermal delivery of LP.

In Vitro and In Vivo Evidence for RNA Adduction Resulting from Metabolic Activation of Methyleugenol

Xiaojing Yang,Yukun Feng,Zhengyu Zhang,Hui Wang,Weiwei Li,Dan Ohtan Wang,Ying Peng,Jiang Zheng

Methyleugenol (ME) is a ubiquitous component in spices and other culinary herbal products. A prevailing theory in ME toxicity is its ability to be metabolically activated by P450 enzymes and sulfotransferases, which initiates sequential reactions of the resulting metabolites with functional biomolecules. The present study aimed at a potential interaction between the reactive metabolites of ME and RNA. Cultured mouse primary hepatocytes were incubated with ME followed by RNA extraction and NaOH and alkaline phosphatase-based RNA hydrolysis. Three adenosine adducts were detected in the hydrolytic mixture by LC–MS/MS. The same adenosine adducts were also detected in hepatic tissues harvested from ME-treated mice. These three adducts were chemically synthesized and structurally characterized by 1H NMR. Additionally, two guanosine adducts and one cytidine adduct were detected in the in vivo samples. These results provided solid evidence that the reactive metabolites of ME attacked RNA, resulting in RNA adduction.

Biomimetic mineralization of carboxymethyl chitosan nanofibers with improved osteogenic activity in vitro and in vivo

Xiujuan Zhao,Liangyu Zhou,Qingtao Li,Qingxia Zou,Chang Du

Inspired by the natural extracellular matrix, the organic-inorganic composite nanofibers are promising scaffolds for bone tissue engineering. Chitosan-based nanofibers are widely used as bone tissue engineering scaffolds with good biocompatibility but pungent solvents are frequently used for its processing. Carboxymethyl chitosan (CMCS), a water-soluble derivative of chitosan, has better biodegradability and bioactivity which allows CMCS to chelate Ca 2+ and induce the deposition of apatite. Moreover, with water as solvent, CMCS nanofibers avoid the acidic salt removal comparing to electrospun-chitosan. In this study, we successfully prepared uniform CMCS nanofibers with the aid of polyethylene oxide (PEO) and obtained the optimized conditions with a voltage of 25 kV and PEO of molecular weight 1000 kDa. We further prepared hydroxyapatite (HA) coated electrospun CMCS nanofibers by biomimetic mineralization using 5 times simulated body fluid. The promotion of osteogenic differentiation of mouse bone marrow stromal cells (mBMSCs) in vitro was evaluated on the nanofibers scaffolds. Cell experiments revealed that CMCS-HA composite nanofibers increased the ALP activity. The gene expression level of Runx2 and ALP were about 1.6 and 4.3 folds at the 7 days, and 5.1 and 10 folds at the 14 days on CMCS-HA nanofibrous membranes than that on CMCS alone samples. The level of OCN increased by 24 and 1.5 times on the CMCS-HA scaffolds than CMCS scaffolds at the 14 and 21 days. In vivo new bone formation by nanofiber scaffolds was investigated in a critical-size rat calvarial bone defect model. Micro-CT results showed that the whole defect was covered by new bone after CMCS-HA filling the defect for 12 weeks. The results of H&E staining and Masson’s trichrome staining on histological sections further confirmed that composite nanofibers promoted new bone formation and maturation.

Direct conversion of biomass derived L-rhamnose to 5-methylfurfural in water in high yield

Yunchao Feng,Zheng Li,Sishi Long,Yong Sun,Xing Tang,Xianhai Zeng,Lu Lin

We report here that L-rhamnose, a less popular renewable and commercially available carbohydrate, can be used as a potential raw material to generate 5-methylfurfural (MF). In particular, nearly 100% yield of MF was achieved over 7 consecutive cycles in NaCl solution containing AlCl3 within 30 min, thus providing an alternative and industrializable way for the production of the potential bio-platform compound MF.

A Novel Fluorescent Nanoparticle for Sensitive Detection of Cry1Ab Protein In Vitro and In Vivo

Xu Xiao,Chen Hao,Cao Yuancheng,Lin Yongjun,Liu Jun’an

Here, we report the synthesis and characterization of CoFe 2 O 4 doping Ag 2 S dendrimer-modified nanoparticles (CoFe 2 O 4 -Ag 2 S DMNs) in Cry1Ab protein detection and imaging. The near-infrared Ag 2 S quantum dots were first prepared by using the thermal decomposition method, followed by modification of the water-soluble quantum dots using the method of solvent evaporation and ligand exchange, and finally the fluorescent magnetic bifunctional nanoparticles were obtained by binding with CoFe 2 O 4 . As-prepared CoFe 2 O 4 -Ag 2 S DMNs were characterized by fluorescence (FL) spectroscopy and transmission electron microscopy (TEM). Results showed that Ag 2 S DMNs could sensitively detect Cry1Ab both in vitro and in vivo. In vitro, the enhanced FL intensity as a function of the concentration is notably consistent with the Langmuir binding isotherm equation in the range of 0–200 ng/mL of Cry1Ab proteins. The detection limit of this method was found to be 0.2 ng/mL. Meanwhile, the fluorescence wavelength was extended to the second near-infrared range (NIR-II, 1.0~1.4 μm), which enables in vivo imaging. This study highlights the importance of NIR QDs doping magnetic materials as a new method to trace Bacillus thuringiensis (Bt) in insects and their potential applications in in vivo NIR tissue imaging.

In-situ reconstructed hollow iridium-cobalt oxide nanosphere for boosting electrocatalytic oxygen evolution in acid

Jiuyi Sun,Rong Zhao,Xiaopo Niu,Meng Xu,Zhihong Xu,Yue Qin,Wenli Zhao,Xinyue Yang,Yunxi Han,Qingfa Wang

Iridium oxide (IrO x )-based materials perform high efficiency and durability for oxygen evolution reaction (OER) in acidic environment. Developing highly efficient OER electrocatalysts with low Ir-loading in acid is still a great challenge. Herein, we fabricated a hollow IrCoO x nanosphere via in-situ electrochemistry reconstruction strategy. The developed hollow Ir 0.16 Co 0.84 O x electrocatalyst with low Ir-loading (51.91 μg cm −2 ) exhibits 71-fold and 42-fold improvement in OER mass activity and TOF value compared with commercial IrO 2 (1032.16 vs 14.44 A g Ir −1 , 0.754 vs 0.018 s −1 ) in 0.1M HClO 4 , respectively. Combining with the analysis of the IrCoO x structure, the electrochemical performance reveals that the superior activity ascribes to the favorable hollow structure, the abundant crystalline/amorphous heterostructure in the IrO x -enriched shell and the atomic heterointerfaces between Co and Ir oxides, which increase the electrochemical active area, accelerate the OER kinetics and lower the charge transfer resistance (2.8 Ω cm 2 ). This work is anticipated to aid the design of novel low Ir-loading electrocatalysts with outstanding catalytic activity for water splitting in acidic environments.