Overproduction of oxidants (reactive oxygen species and reactive nitrogen species) in the human body is responsible for the pathogenesis of some diseases. The scavenging of these oxidants is thought ...to be an effective measure to depress the level of oxidative stress of organisms. It has been reported that intake of vegetables and fruits is inversely associated with the risk of many chronic diseases, and antioxidant phytochemicals in vegetables and fruits are considered to be responsible for these health benefits. Antioxidant phytochemicals can be found in many foods and medicinal plants, and play an important role in the prevention and treatment of chronic diseases caused by oxidative stress. They often possess strong antioxidant and free radical scavenging abilities, as well as anti-inflammatory action, which are also the basis of other bioactivities and health benefits, such as anticancer, anti-aging, and protective action for cardiovascular diseases, diabetes mellitus, obesity and neurodegenerative diseases. This review summarizes recent progress on the health benefits of antioxidant phytochemicals, and discusses their potential mechanisms in the prevention and treatment of chronic diseases.
As one of the fascinating high capacity cathodes, O3‐type layered oxides usually suffer from their intrinsic air sensitivity and sluggish kinetics originating from the spontaneous lattice Na ...extraction during air exposure and high tetrahedral site energy of Na+ diffusion transition state. What is worse, the improvement on the two handicaps is hard to simultaneously realize because of the contradiction between Na containment suggested in air stability mechanism and enhanced Na diffusion mentioned in kinetics strategy. Herein, it is shown that a simple strategy of introducing proper Na vacancies into lattice can simultaneously realize a dual performance improvement. Na vacancies decrease the charge density on transitional metal ions and enhance the antioxidative capability of material, ensuring a stable lattice Na containment for Na0.93Li0.12Ni0.25Fe0.15Mn0.48O2 when exposed to air. Additionally, more Na+ diffusional sites and enlarged Na layer spacing are obtained and result in a significantly decreased energy barrier from ≈1000 to 300 meV and a high rate capability of 70.8% retention at 2000 mA g−1. Remarkably, such a strategy can be easily realized by either pre‐ or post‐treating, which exhibits excellent universality for various O3 materials, implying its enormous potential to promote the commercial application of O3‐type cathodes.
A universal strategy of introducing proper Na vacancies into a crystal lattice is proposed to simultaneously improve air‐stability and kinetics of O3‐type layered oxide cathodes. The dual improvement benefits from the multiple effects of Na vacancies on crystalline and electronic structure, namely, decreased charge density on transition metal ions, enhanced antioxidative capability, decreased Na+ diffusion barrier, and optimized migration path.
Gut bacteria are an important component of the microbiota ecosystem in the human gut, which is colonized by 1014 microbes, ten times more than the human cells. Gut bacteria play an important role in ...human health, such as supplying essential nutrients, synthesizing vitamin K, aiding in the digestion of cellulose, and promoting angiogenesis and enteric nerve function. However, they can also be potentially harmful due to the change of their composition when the gut ecosystem undergoes abnormal changes in the light of the use of antibiotics, illness, stress, aging, bad dietary habits, and lifestyle. Dysbiosis of the gut bacteria communities can cause many chronic diseases, such as inflammatory bowel disease, obesity, cancer, and autism. This review summarizes and discusses the roles and potential mechanisms of gut bacteria in human health and diseases.
The aryl hydrocarbon receptor (AhR) regulates peripheral immunity; but its role in microglia‐mediated neuroinflammation in the brain remains unknown. Here, we demonstrate that AhR mediates both ...anti‐inflammatory and proinflammatory effects in lipopolysaccharide (LPS)‐activated microglia. Activation of AhR by its ligands, formylindolo3,2‐bcarbazole (FICZ) or 3‐methylcholanthrene (3MC), attenuated LPS‐induced microglial immune responses. AhR also showed proinflammatory effects, as evidenced by the findings that genetic silence of AhR ameliorated the LPS‐induced microglial immune responses and LPS‐activated microglia‐mediated neurotoxicity. Similarly, LPS‐induced expressions of tumor necrosis factor α (TNFα) and inducible nitric oxide synthase (iNOS) were reduced in the cerebral cortex of AhR‐deficient mice. Intriguingly, LPS upregulated and activated AhR in the absence of AhR ligands via the MEK1/2 signaling pathway, which effects were associated with a transient inhibition of cytochrome P450 1A1 (CYP1A1). Although AhR ligands synergistically enhance LPS‐induced AhR activation, leading to suppression of LPS‐induced microglial immune responses, they cannot do so on their own in microglia. Chromatin immunoprecipitation results further revealed that LPS‐FICZ co‐treatment, but not LPS alone, not only resulted in co‐recruitment of both AhR and NFκB onto the κB site of TNFα gene promoter but also reduced LPS‐induced AhR binding to the DRE site of iNOS gene promoter. Together, we provide evidence showing that microglial AhR, which can be activated by LPS, exerts bi‐directional effects on the regulation of LPS‐induced neuroinflammation, depending on the availability of external AhR ligands. These findings confer further insights into the potential link between environmental factors and the inflammatory brain disorders. GLIA 2015;63:1138–1154
Main Points
LPS upregulates and activates AhR in microglia.
AhR mediates the LPS‐induced pro‐inflammatory responses in microglia and mouse brain.
AhR ligand application shunts LPS‐activated AhR to the anti‐inflammatory mode involving AhR‐NFκB crosstalk.
We report here a simple, high-yield yet low-cost approach to design single-layer MoS2 nanosheets with controllable size via an improved oleum treatment exfoliation process. By decorating MoS2 ...nanosheets with chitosan, these functionalized MoS2 nanosheets have been developed as a chemotherapeutic drug nanocarrier for near-infrared (NIR) photothermal-triggered drug delivery, facilitating the combination of chemotherapy and photothermal therapy into one system for cancer therapy. Loaded doxorubicin could be controllably released upon the photothermal effect induced by 808 nm NIR laser irradiation. In vitro and in vivo tumor ablation studies demonstrate a better synergistic therapeutic effect of the combined treatment, compared with either chemotherapy or photothermal therapy alone. Finally, MoS2 nanosheets can also be used as a promising contrast agent in X-ray computed tomography imaging due to the obvious X-ray absorption ability of Mo. As a result, the high-throughput oleum treatment exfoliation process could be extended for fabricating other 2D nanomaterials, and the NIR-triggered drug release strategy was encouraging for simultaneous imaging-guided cancer theranostic application.
Layered molybdenum disulfide (MoS2)–graphene composite is synthesized by a modified l-cysteine-assisted solution-phase method. The structural characterization of the composites by energy dispersive ...X-ray analysis, X-ray powder diffraction, Fourier transform infrared spectroscopy, XPS, Raman, and transmission electron microscope indicates that layered MoS2–graphene coalescing into three-dimensional sphere-like architecture. The electrochemical performances of the composites are evaluated by cyclic voltammogram, galvanostatic charge–discharge and electrochemical impedance spectroscopy. Electrochemical measurements reveal that the maximum specific capacitance of the MoS2–graphene electrodes reaches up to 243 F g−1 at a discharge current density 1 A g−1. The energy density is 73.5 Wh kg−1 at a power density of 19.8 kW kg−1. The MoS2–graphene composites electrode shows good long-term cyclic stability (only 7.7% decrease in specific capacitance after 1000 cycles at a current density of 1 A g−1). The enhancement in specific capacitance and cycling stability is believed to be due to the 3D MoS2–graphene interconnected conductive network which promotes not only efficient charge transport and facilitates the electrolyte diffusion, but also prevents effectively the volume expansion/contraction and aggregation of electroactive materials during charge–discharge process. Taken together, this work indicates MoS2–graphene composites are promising electrode material for high-performance supercapacitors.
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•Layered MoS2–graphene composite were synthesized.•Supercapacitor electrode based on layered MoS2–graphene composite were fabricated.•Microstructures and electrochemical properties of the electrodes were tested.•Improved electrochemical properties of the novel electrodes were observed.•MoS2–graphene composite exhibited good cycling stability and capacitance retention.
A novel Salamo-Salen-Salamo-Zn(II) complex fluorescent sensor ZT was successfully synthesized, and exhibited fluorescent quenching effect and excellent applicability through solid-state fluorescent ...strips and biological imaging experiments on zebrafish and bean sprout to highly sensitive monitoring H2PO4- ions.
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•A novel and effective Salamo-Salen-Salamo-Zn fluorescent sensor ZT was successfully developed.•It is worth noting that ZT serves as a fluorescence ON-OFF sensor by adding H2PO4- in the presence of excess other anions.•The sensor ZT was successfully studied using the solid-state fluorescence of the test strips.•Bioimaging experiments were conducted on zebrafish and bean sprouts using a confocal microscope.
A newly designed and synthesized Salamo-Salen-Salamo-Zn(II) complex sensor (sensor ZT) was extensively explored for anion sensing studies. The selectivity and sensitivity of the sensor ZT towards H2PO4- ions were based on ICT and CHEF effects, and via displacement pathways in DMSO/H2O (9:1, v/v) medium in the presence of other anions like, PO43-, HPO42- and P2O74- in a short time, separately. The prepared ZT sensor has excellent association constant and low detection lines. The sensing mechanism and binding mode of the sensor were studied by UV–Vis spectroscopy, HR-MS, 1H NMR titration and theory calculations (DFT & TD-DFT) for analytes. The time response and stability of the sensor are also given. Meanwhile, the sensor ZT can be widely used as a simple and effective solid-state optical sensor to detect H2PO4- by intuitive fluorescence changes. In addition, besides the environment can be used as a powerful instrument for detecting H2PO4-, based on the good biocompatibility and tissue permeability of ZT, effectively monitoring H2PO4- in cellular distribution by confocal microscopy using Zebrafish and bean sprout.
The Layered tungsten sulfide (WS2)-graphene (Gr) composites were prepared by a facile l-cysteine-assisted solution-phase method. Field emission scanning electron microscopy (SEM) and transmission ...electron microscopy (TEM) characterizations showed that layered WS2 nanosheets were highly wrapped in the creasy Gr. The electrochemical properties of the nanocomposite film were investigated by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The as-prepared WS2-Gr composite showed excellent electrochemical catalytic activities toward the oxidation of catechol (CT), resorcinol (RS) and hydroquinone (HQ). The superior electrochemical performances of the composites could be attributed to the robust composite structure and superior conductivity, large surface area and good flexibility of WS2-Gr composites. Some kinetic parameters, such as the electron transfer number (n), charge transfer coefficient (α) and the apparent heterogeneous electron transfer rate constant (ks), were calculated. Differential pulse voltammetry was used for the simultaneous determination of CT, RS and HQ in their ternary mixture. The calibration curves for CT, RS and HQ were obtained in the range of 1×10−6 to 1×10−4. The detection limits were 1×10−7molL−1 for RS and HQ, and 2×10−7molL−1 for CT (S/N=3). The developed sensor was used to detect CT, RS and HQ in environmental water samples with recoveries of 93.6–104.8%
To evaluate the value of fasting plasma glucose (FPG) value in the first prenatal visit to diagnose gestational diabetes mellitus (GDM).
Medical records of 17,186 pregnant women attending prenatal ...clinics in 13 hospitals in China, including the Peking University First Hospital (PUFH), were examined. Patients with pre-GDM were excluded; data for FPG at the first prenatal visit and one-step GDM screening with 75-g oral glucose tolerance test (OGTT) performed between 24 and 28 weeks of gestation were collected and analyzed.
The median ± SD FPG value was 4.58 ± 0.437. FPG decreased with increasing gestational age. FPG level at the first prenatal visit was strongly correlated with GDM diagnosed at 24-28 gestational weeks (χ(2) = 959.3, P < 0.001). The incidences of GDM were 37.0, 52.7, and 66.2%, respectively, for women with FPG at the first prenatal visit between 5.10 and 5.59, 5.60 and 6.09, and 6.10-6.99 mmol/L. The data of PUFH were not statistically different from other hospitals.
Pregnant women (6.10 ≤ FPG < 7.00 mmol/L) should be considered and treated as GDM to improve outcomes; for women with FPG between 5.10 and 6.09 mmol/L, nutrition and exercise advice should be provided. An OGTT should be performed at 24-28 weeks to confirm or rule out GDM. Based on our data, we cannot support an FPG value ≥5.10 mmol/L at the first prenatal visit as the criterion for diagnosis of GDM.
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