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•Hierarchical ZnO nanospheres are prepared by microwave-assisted gas-liquid interfacial method.•The performances of ZnO nanospheres gas sensor are studied.•The ZnO sensor shows ...excellent selectivity and high response to NO2 even at room temperature and ppb concentration.
The development of high-performance nitrogen dioxide gas sensors is indispensable and critical for environmental monitoring and medical fields. Different nanostructural ZnO were efficiently synthesized via a microwave-assisted gas-liquid interface method and the gas sensing performance of ZnO-based gas sensors with different morphologies was comparatively investigated. The results show that the ZnO-3 sensor (microwave reaction temperature is 180 ℃) has the best sensing performance to NO2 at lower operating temperature (120 ℃). It exhibits a high response (Rg/Ra = 397), short response/recovery time (21 s/30 s), and good selectivity to 100 ppm NO2. Moreover, the ZnO-3 sensor exhibits remarkably high response (185 to 100 ppm NO2) even at 25 ℃. In addition, the ZnO sensor can maintain good stability and repeatability in long-term cycling tests to 5 ppm NO2. Evidently, this research offers a reference value for the efficient synthesis of ZnO nanomaterials and real-time detection of nitrogen dioxide emissions.
IMPORTANCE: The association of nonmotor features and Parkinson disease (PD) is increasingly recognized. Evidence suggests that inflammation may play a role in PD pathologic features and symptoms. ...OBJECTIVE: To quantitatively summarize the peripheral inflammatory cytokine data available for patients with PD. DATA SOURCE: A systematic search of peer-reviewed English-language articles from PubMed, PsycINFO, and the Cochrane Library without year limitation was performed from December 7, 2015, to March 23, 2016. The search terms included inflammation or cytokine or chemokine or tumor necrosis factor or interleukin or interferon or C-reactive protein AND Parkinson disease. STUDY SELECTION: Studies were included if they provided data on peripheral blood cytokine concentrations in patients with PD and a healthy control group. Studies were excluded if they contained in vitro analysis of stimulated or unstimulated levels of cytokines, samples that overlapped with other studies, patients not diagnosed with PD at blood sampling, or if the cytokine analyzed was assessed in fewer than 3 studies. DATA EXTRACTION AND SYNTHESIS: Data were extracted from the 25 included studies encompassing 1547 unique patients with PD and 1107 unique controls by 2 independent investigators. Data were pooled using a random-effects model with the Comprehensive Meta-analysis software. Effect sizes were generated as standardized mean differences of cytokine concentrations between patients with PD and healthy controls and converted to the Hedges g statistic. MAIN OUTCOMES AND MEASURES: Blood cytokine concentrations in patients with PD compared with controls. Aberrations in peripheral cytokine levels were hypothesized to be related to PD. RESULTS: Among the 2654 study participants, concentrations of interleukin 6 (IL-6) (Hedges g, 0.325; 95% CI, 0.007-0.643; P = .045) in 13 studies, tumor necrosis factor (Hedges g, 0.354; 95% CI, 0.144-0.563; P = .001) in 9 studies, IL-1β (Hedges g, 0.382; 95% CI, 0.142-0.621; P = .002) in 6 studies, C-reactive protein (Hedges g, 0.323; 95% CI, 0.052-0.593; P = .02) in 6 studies, IL-10 (Hedges g, 0.329; 95% CI, 0.051-0.607; P = .02) in 5 studies, RANTES (regulated on activation, normal T-expressed, and presumably secreted) (Hedges g, 0.605; 95% CI, 0.111-1.099; P = .02) in 5 studies, and IL-2 (Hedges g, 0.789; 95% CI, 0.105-1.472; P = .02) in 3 studies were significantly higher in patients with PD compared with healthy controls. No differences were found between patients with PD and healthy controls for concentrations of interferon-γ (Hedges g, 0.745; 95% CI, −0.192 to 1.682; P = .12) in 5 studies, IL-4 (Hedges g, 0.031; 95% CI, −0.191 to 0.253; P = .79) in 3 studies, and IL-8 (Hedges g, 0.072; 95% CI, −0.136 to 0.279; P = .50) in 3 studies. CONCLUSIONS AND RELEVANCE: The findings of the meta-analysis demonstrated higher peripheral concentrations of IL-6, tumor necrosis factor, IL-1β, IL-2, IL-10, C-reactive protein, and RANTES in patients with PD, strengthening the clinical evidence that PD is accompanied by an inflammatory response.
The types and quantities of active sites play a critical role in catalysis. Herein, ZnO nanoparticles encapsulated into N‐doped porous carbon has been rationally prepared by the pyrolysis of a ...metal–organic framework (MOF) followed by a moderate oxidation treatment. The resulting catalyst exhibits excellent activity, selectivity, and recyclability in the CO2 cycloaddtion reactions with epoxides owing to the synergy of multiple sites inherited from the MOF and generated by the oxidation process.
Synergistic effects: ZnO nanoparticles encapsulated into N‐doped porous carbon with multiple catalytic sites are rationally synthesized by pyrolysis of a metal–organic framework followed by a moderate oxidation treatment. Based on the synergy of multiple sites (ZnO, pyridinic N, hydroxyl, and carboxyl groups), the resultant catalyst exhibits excellent activity, selectivity, and recyclability in the CO2 cycloaddtion reactions with epoxides under mild conditions.
Light‐responsive adsorbents capture significant attention due to their tailorable performance upon light irradiation. The modulation of such adsorbents is mainly based on weak (physical) interactions ...caused by steric hindrance while tuning strong interaction with target adsorbates is scarce. Here we report smart π‐complexation adsorbents, which can adjust the π‐complexation of active sites via light irradiation. A typical metal‐organic framework, MIL‐101‐NH2, was decorated with azobenzene motifs, and Cu+ as π‐complexation active sites were introduced subsequently. The reversible light‐induced isomerization of azobenzene regulates the surface electrostatic potentials around Cu+ from −0.038 to 0.008 eV, causing shielding and exposure effects. The alteration of CO uptake is achieved up to 54 % via changing light, while that on MIL‐101‐NH2 is negligible. This study provides a clue for designing target‐specific smart materials to meet the practical stimuli‐responsive adsorption demands.
Smart adsorbents are fabricated by introducing Cu+ into azobenzene‐decorated metal‐organic frameworks, in which azobenzene acts as light‐responsive motifs and Cu+ as π‐complexing sites. Ultraviolet‐/visible‐light irradiation triggers the isomerization of azobenzene, causing the changes in electrostatic potential around Cu+. This exposure/shelter effect adjusts CO capture and release by shifting light.
Summary
The sirtuin family of nicotinamide adenine dinucleotide‐dependant (NAD) deacetylases plays an important role in aging and metabolic regulation. In yeast, the Sir2 gene and its homolog Hst2 ...independently mediate the action of caloric restriction on lifespan extension. The mammalian Sir2 ortholog, SIRT1, is up‐regulated by caloric restriction and deacetylates a variety of substrates, including histones and the forkhead box O (FOXO) transcription factors. The mammalian ortholog of Hst2, SIRT2, was shown to co‐localize with microtubules and functions as α‐tubulin deacetylase. During G2/M phase, SIRT2 proteins enter nuclei and deacetylate histones. We report here that the expression of SIRT2 is elevated in the white adipose tissue and kidney of caloric‐restricted mice. Oxidative stress, such as hydrogen peroxide treatment, also increases SIRT2 expression in cells. We have demonstrated that SIRT2 binds to FOXO3a and reduces its acetylation level. SIRT2 hence increases FOXO DNA binding and elevates the expression of FOXO target genes, p27Kip1, manganese superoxide dismutase and Bim. As a consequence, SIRT2 decreases cellular levels of reactive oxygen species. Furthermore, as Bim is a pro‐apoptotic factor, SIRT2 promotes cell death when cells are under severe stress. Therefore, mammalian SIRT2 responds to caloric restriction and oxidative stress to deacetylate FOXO transcription factors.
Ag(I) have been applied as active sites to adsorptive desulfurization of transportation fuels. However, its introduction brings the issues of instability and difficulty in desorption. Here, Ag(0) was ...dispersed in metal‐organic frameworks and used as the photothermal active sites with high stability for desulfurization. Unlike Ag(I), Ag(0) is insensitive to light and can be precisely heated for desorption through surface plasmon resonance. Interestingly, Ag(0) has weak interactions with dibenzothiophene than π‐complexation, but shows the comparable uptake and selectivity to that of Ag(I). The weak adsorbent‐adsorbate interactions fit the photomodulation on desorption where light energy was precisely used to heat the active sites of Ag(0), avoiding heat conduction and loss in the traditional temperature‐swing adsorption. In a fixed bed, the desorption time of the photomodulation process was reduced by nearly half compared with the washing method with hot solvent, and the energy used can be saved by 46.2% in theory.
High-entropy ceramics attract more and more attention in recent years. However, mechanical properties especially strength and fracture toughness for high-entropy ceramics and their composites have ...not been comprehensively reported. In this work, high-entropy (Ti
0.2
Zr
0.2
Hf
0.2
Nb
0.2
Ta
0.2
)B
2
(HEB) monolithic and its composite containing 20 vol% SiC (HEB–20SiC) are prepared by hot pressing. The addition of SiC not only accelerates the densification process but also refines the microstructure of HEB, resulting in improved mechanical properties. The obtained dense HEB and HEB–20SiC ceramics hot pressed at 1800 ℃ exhibit four-point flexural strength of 339±17 MPa and 447±45 MPa, and fracture toughness of 3.81±0.40 MPa·m
1/2
and 4.85±0.33 MPa·m
1/2
measured by single-edge notched beam (SENB) technique. Crack deflection and branching by SiC particles is considered to be the main toughening mechanisms for the HEB–20SiC composite. The hardness
Hv
0.2
of the sintered HEB and HEB–20SiC ceramics is 23.7±0.7 GPa and 24.8±1.2 GPa, respectively. With the increase of indentation load, the hardness of the sintered ceramics decreases rapidly until the load reaches about 49 N, due to the indentation size effect. Based on the current experimental investigation it can be seen that the room temperature bending strength and fracture toughness of the high-entropy diboride ceramics are within ranges commonly observed in structure ceramics.
Porous liquids (PLs), a summation of porous hosts and bulky solvents bestowing permanent cavities, are the prominent emerging materials. Despite great efforts, exploration of porous hosts and bulky ...solvents is still needed to develop new PL systems. Metal‐organic polyhedra (MOPs) with discrete molecular architectures can be considered as porous hosts; however, many of them are insoluble entities. Here we report the transformation of type III PL to type II PLs by tuning the surface rigidity of insoluble MOP, Rh24L24, in a bulky ionic liquid (IL). Functionalization of N‐donor molecules on Rh−Rh axial sites ensue their solubilization in bulky IL which confer type II PLs. Experimental and theoretical studies reveal the bulkiness of IL as per the cage apertures, and the cause of their dissolution as well. The obtained PLs, capturing more CO2 than neat solvent, have depicted higher catalytic activity for CO2 cycloaddition compared to individual MOPs and IL.
By incorporating N‐donor molecules on the Rh−Rh axial sites of insoluble RhMOP, and making it soluble as porous host in bulky ionic liquid, a type III porous liquid was transformed into type II porous liquids for better catalyzing the cycloaddition of CO2.
The limitations of liver biopsy have led to the development of indirect noninvasive models for liver fibrosis assessment. We aimed to evaluate and compare the performance of 30 noninvasive models to ...predict fibrosis stage in treatment‐naïve and treated chronic hepatitis B (CHB) patients. A total of 576 Chinese treatment‐naïve CHB patients and 236 treated CHB patients who had undergone percutaneous liver biopsy were included in the analysis. Histological grading and staging was assessed by the Ishak scoring system. The diagnostic accuracies of 30 noninvasive models were assessed by area under the receiver operating characteristic curves (AUROCs). In treatment‐naïve CHB patients, the AUROCs of the 30 noninvasive models for discriminating significant fibrosis (SF) were less than 0.800, and only the AUROC of the PP score for diagnosing advanced fibrosis (AF) was more than 0.800, while the AUROCs of FIB‐4, FibroQ, HB‐F, Lok index, PHP score and PP score for predicting cirrhosis were greater than 0.800. In treated CHB patients, only the AUROCs of APRI, GUCI, King's score and Wang I for identifying cirrhosis were more than 0.800. The Spearman correlation analysis identified that only the changes in FCI and Virahep‐C model values were weakly correlated with changes in Ishak fibrosis scores before and after treatment (r = 0.206, p = 0.008; r = 0.187, p = 0.016, respectively). In conclusion, in Chinese CHB patients, the 30 existing noninvasive models were not suitable for assessing each stage of fibrosis except cirrhosis before and after antiviral therapy, especially in gauging progression and regression of liver fibrosis following therapy.
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