• Albright Drejer posted an update 1 week, 1 day ago

    In this study, two kinds of composites with the structure of graphene oxide (GO) sheets wrapped magnetic nanoparticles were investigated on their regeneration. The composites have a similar core-shell structure, but the interactions between the core and shell are quite different, which are electrostatic and covalent. They were characterized by scanning/transmission electron microscopy, power X-ray diffraction, and vibrating sample magnetometer analysis. Their morphologies and structures of the samples had been revealed using methylene blue and Pb(II) as adsorbates during regeneration. The results showed that the composites with covalent bonding interaction could maintain a stable core-shell structure and present a good regeneration performance for adsorption-desorption of methylene blue and Pb(II). The composites with electrostatic interaction could approximately preserve its core-shell structure and could be recyclable for adsorption-desorption of methylene blue, however, they would disintegrate its core-shell structure during adsorption/desorption of Pb(II), thus greatly decreasing their regeneration performance. The regeneration mechanisms of the composites were analyzed, which could provide a useful theoretical guide to design the GO sheets wrapped magnetic nanoparticles composites. Copyright © 2020 Hu, Zhang, Li and Zhu.Changes in the abundance of antennary fucosylated glycans in human total plasma N-glycome (TPNG) have been associated with several diseases ranging from diabetes to various forms of cancer. However, it is challenging to address this important part of the human glycome. Most commonly, time-consuming chromatographic separations are performed to differentially quantify core and antenna fucosylation. Obtaining sufficient resolution for larger, more complex glycans can be challenging. We introduce a matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) assay for the relative quantitation of antennary fucosylation in TPNG. N-linked glycans are released from plasma by PNGase F and further treated with a core fucosidase before performing a linkage-informative sialic acid derivatization. The core fucosylated glycans are thus depleted while the remaining antennary fucosylated glycans are quantitated. Simultaneous quantitation of α2,3-linked sialic acids and antennary fucosylation allows an estimation of the sialyl-Lewis x motif. The approach is feasible using either ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry or time-of-flight mass spectrometry. The assay was used to investigate changes of antennary fucosylation as clinically relevant marker in 14 colorectal cancer patients. In accordance with a previous report, we found elevated levels of antennary fucosylation pre-surgery which decreased after tumor resection. The assay has the potential for revealing antennary fucosylation signatures in various conditions including diabetes and different types of cancer. Copyright © 2020 Rebello, Nicolardi, Lageveen-Kammeijer, Nouta, Gardner, Mesker, Tollenaar, Spencer, Wuhrer and Falck.Anabasine (ANA), a major piperidine alkaloid originally isolated from wild tobacco trees (Nicotiana glauca), has been known to induce serious developmental toxicities such as skeletal deformities in livestock and humans. In this study, we thoroughly investigated the supramolecular nano-encapsulations of ANA by an artificial nanocontainer, cucurbit[7] uril (CB[7]), and examined the influences of the nano-encapsulation on ANA’s inherent developmental toxicities on a zebrafish model. We have shown that CB[7] formed 11 host-guest inclusion complexes with ANA via a relatively high binding strength [K a of (7.45 ± 0.31) × 104 M-1] in an aqueous solution, via UV-vis and 1H nuclear magnetic resonance spectroscopic titrations, as well as isothermal titration calorimetry titration. As a consequence, CB[7] significantly attenuated the developmental toxicity of ANA on zebrafish in vivo. In contrast, for a comparative purpose, β-CD didn’t exert any influence on the toxicity of ANA due to its weak binding with ANA, which was not even measurable via either spectroscopic methods or ITC titration. This is the first head-to-head comparison of this pair of nanocontainers, CB[7] and β-CD, on their potential roles in influencing the toxicity of guest molecules and the results suggested that CB[7] could become a more promising functional excipient for reducing the inherent toxicities of active pharmaceutical ingredients, particularly alkaloids that may form relatively strong host-guest binding species with the host. Copyright © 2020 Gao, Yang, Wang, Zhong, Hu and Wang.Oxygen reduction reaction (ORR) electrocatalysts derived from biomass have become one of the research focuses in hetero-catalysis due to their low cost, high performance, and reproducibility properties. Related researches are of great significance for the development of next-generation fuel cells and metal-air batteries. Herein, the preparation methods of various biomass-derived catalysts and their performance in alkaline, neutral, and acidic media are summarized. This review clarifies the research progress of biomass carbon-based electrocatalysts for ORR in acidic, alkaline and neutral media, and discusses the future development trends. This minireview can give us an important enlightenment to practical application in the future. Copyright © 2020 Wang, Wang, Yang, Ku, Yang, Liu and Lu.In the present study, we have synthesized silver-copper nanocomposites (Ag-Cu NCs) using an Olax scandens leaf extract (green synthesis method) and evaluated their antimicrobial potential against less susceptible pathogens. The kinetics of Ag-Cu NCs synthesis was followed by UV-VIS and fluorescence spectroscopy. The physicochemical characterization of as-synthesized Ag-Cu NCs was executed using electron microscopy, Energy Dispersive X-Ray, Fourier Transform Infrared Spectroscopy, and a Differential Light Scattering method. As-synthesized Ag-Cu NCs induced the formation of Reactive Oxygen Species (ROS), thereby causing alteration and decrementation of cellular proteins, DNA, lipids, etc., and eventually leading to cell death, as determined by a Live/Dead assay. Next, we assessed the anti-biofilm potential of as-synthesized Ag-Cu NCs against biofilm forming bacteria. The as-synthesized Ag-Cu NCs, when compared to monometallic silver nanoparticles, exhibited significantly higher anti-microbial activity against both sensitive as well as drug resistant microbial isolates. Copyright © 2020 Mujeeb, Khan, Jamal, Badre Alam, Saeed, Kazmi, Alshameri, Kashif, Ghazi and Owais.In this manuscript, we constructed a Ni/MWCNTs absorber and properly adjusted the permittivity resulted from absorber content in the PVDF to optimize impedance matching properties. Both ε’ and ε″ increase obviously with the increasing content of Ni/MWCNTs in PVDF, demonstrating that dielectric properties are dependent on the conductivity. Moderate dielectric properties and excellent impedance matching can be obtained for the filler content of 20 wt% Ni/MWCNTs. Reasonable impedance matching allows electromagnetic waves to propagate into the materials and finally realize energy dissipation through dielectric loss and interfacial polarization. As expected, the minimum reflection loss (RL) of -46.85 dB at 6.56 GHz with a low filler loading (20 wt%) and wide effective bandwidth (RL less then -10 dB) of 14.0 GHz in the thickness range of 1.5-5.0 mm was obtained for the commercial Ni/MWCNTs composites, which is promising for mass production in industrial applications. Our findings offer an effective and industrialized way to design high-performance material to facilitate the research in microwave absorption. Copyright © 2020 Zhao, Wang and Wang.Graphene-based MoS2 nanocomposites are expected to be promising anode materials for lithium ion batteries because of their large specific capacity and high conductivity. However, the aggregation of graphene and the weak interaction between the two components hinder their practical application. Inspired by the sandwich structure, novel three-dimensional flower-like MoS2-PrGO sandwich composites were proposed as an advanced anode material for lithium-ion batteries. The separated 2D ultrathin rGO nano-sheets were connected by PEO chains and assembled into a well-organized 3D layered spatial structure, which not only avoids the aggregation of graphene but also accommodates a high mass loading of the micro-scale MoS2 nano-flowers. MoS2 nano-flowers with open architecture deliver large specific area. The rGO interlayers act as a conductive framework, making all flower-like MoS2 nano-stuffing electrochemically active. learn more The ultra-thin 2D nano-sheets provide excellent cycle stability due to their neglectable volume changes during cycling. The 3D flower-like MoS2-PrGO sandwich composites deliver high energy density, excellent conductivity and stable cyclic performance during charge-discharge process. With a nearly 100% coulombic efficiency, their reversible capacity is retained at 1,036 mA h g-1 even after 500 cycles at current densities of 100 mA g-1. This novel design strategy provides a broad prospect for the development of advanced anode materials for superior lithium storage. Copyright © 2020 Zhao, Zhang, Zhang, Zhou, Weng and Xiong.The root barks of perennial herb Dictamnus dasycarpus (Cortex Dictamni) were reported to be rich in anti-inflammation activity constituents, limonoids. Then, the investigation of anti-inflammation therapeutic limonoids from this plant was developed in the present study. Through the combination of various chromatographies isolation, six new limonoids, named dictamlimonol A (1), dictamlimonoside B (2), and dictamlimonols C-F (3-6), along with seven known ones (7-13), were obtained. Their structures were ascertained based on the extensive spectroscopic methods and ECD data analysis. Among them, compound 1 was the first 7,19-epoxy limonoid found in natural products. The anti-inflammatory effects of all limonoids were evaluated in lipopolysaccharide (LPS)-treated RAW 264.7 cell lines. Compounds 5, 7-11, and 13 were found to inhibit LPS-induced nitric oxide (NO) production. Moreover, dictamlimonol D (5), fraxinellone (11), and dasylactone A (13) were found to reduce the LPS-induced expressions of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and cyclooxygenase-2 (COX-2) at the protein levels in a dose-dependent manner. These findings support that the administration of Cortex Dictamni may be beneficial for inflammation. Copyright © 2020 Chen, Ruan, Sun, Wang, Yang, Zhang, Yan, Yu, Guo, Zhang and Wang.Purpose This study aimed to explore the association of occupational stress with fatigue and to examine the mediating role of psychological capital (PsyCap) among Chinese physicians. Materials and Methods A cross-sectional study was conducted in Liaoning province, China, in 2018. Using a multistage stratified sampling method, a total of 1,500 physicians participated and 1,104 (73.6%) physicians responded effectively. The study used a self-administered questionnaire consisting of the 14-item Fatigue Scale (FS-14), the Effort-reward Imbalance questionnaire (ERI), the Psychological Capital Questionnaire (PCQ) and items about demographic and working characteristics. Hierarchical multiple regression analyses were performed to explore the association of occupational stress, PsyCap, and fatigue among physicians. Asymptotic and resampling strategies were used to examine the mediating effect. Results The incidence of fatigue among Chinese physicians was 83.70%. The average level of fatigue was 7.96 ± 3.95 (mean ± SD). Occupational stress and PsyCap were significantly associated with fatigue.