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1.
Ecotoxicol Environ Saf ; 200: 110744, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32460050

RESUMO

Hematite nanoparticles (α-Fe2O3 NPs) were successfully synthesized by a low-cost solvent-free reaction using Ferrous sulfate waste (FeSO4·7H2O) and pyrite (FeS2) as raw materials and employed for the decolorization of Methyl Orange by the photo-Fenton system. The properties of α-Fe2O3 NPs before and after photo-Fenton reaction were characterized by X-ray powder diffraction (XRD), Field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR) spectrum and X-ray photoelectron spectroscopy (XPS), and the optical properties of α-Fe2O3 NPs were analyzed by UV-vis diffuse reflectance spectra (UV-vis DRS) and Photoluminescence (PL) spectra. The analytic results showed that the as-formed samples having an average diameter of ~50 nm exhibit pure phase hematite with sphere structure. Besides, little differences were found by comparing the characterization data of the particles before and after the photo-Fenton reaction, indicating that the photo-Fenton reaction was carried out in solution rather than on the surface of α-Fe2O3 NPs. A 24 central composite design (CCD) coupled with response surface methodology (RSM) was applied to evaluate and optimize the important variables. A significant quadratic model (P-value<0.0001, R2 = 0.9664) was derived using an analysis of variance (ANOVA), which was adequate to perform the process variables optimization. The optimal process conditions were performed to be 395 nm of the light wavelength, pH 3.0, 5 mmol/L H2O2 and 1 g/L α-Fe2O3, and the decolorization efficiency of methyl orange was 99.55% at 4 min.

2.
Lasers Surg Med ; 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32173886

RESUMO

BACKGROUND AND OBJECTIVES: In our previous proof-of-principle study, transcranial photobiomodulation (tPBM) with 1,064-nm laser was reported to significantly increase concentration changes of oxygenated hemoglobin (∆[HbO]) and oxidized-state cytochrome c oxidase (∆[oxi-CCO]) in the human brain. This paper further investigated (i) its validity in two different subsets of young human subjects at two study sites over a period of 3 years and (ii) age-related effects of tPBM by comparing sham-controlled increases of ∆[HbO] and ∆[oxi-CCO] between young and older adults. STUDY DESIGN/MATERIALS AND METHODS: We measured sham-controlled ∆[HbO] and ∆[oxi-CCO] using broadband near-infrared spectroscopy (bb-NIRS) in 15 young (26.7 ± 2.7 years of age) and 5 older (68.2 ± 4.8 years of age) healthy normal subjects before, during, and after right-forehead tPBM/sham stimulation with 1,064-nm laser. Student t tests were used to test statistical differences in tPBM-induced ∆[HbO] and ∆[oxi-CCO] (i) between the 15 young subjects and those of 11 reported previously and (ii) between the two age groups measured in this study. RESULTS: Statistical analysis showed that no significant difference existed in ∆[HbO] and ∆[oxi-CCO] during and post tPBM between the two subsets of young subjects at two study sites over a period of 3 years. Furthermore, the two age groups showed statistically identical net increases in sham-controlled ∆[HbO] and ∆[oxi-CCO]. CONCLUSIONS: This study provided strong evidence to validate/confirm our previous findings that tPBM with 1,064-nm laser enables to increase cerebral ∆[HbO] and ∆[oxi-CCO] in the human brain, as measured by bb-NIRS. Overall, it demonstrated the robust reproducibility of tPBM being able to improve cerebral hemodynamics and metabolism of the human brain in vivo in both young and older adults. Lasers Surg. Med. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.

3.
Nanotechnology ; 31(25): 255402, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32143193

RESUMO

A system containing polyoxometalate ([Co-POM]2-) and [Ru(bpy)3]2+ as constructed for visible-light-induced CO2 conversion to syngas. In diluted CO2, high efficiency of 56.8 mmol g-1 h-1 in syngas production was gained, exceeding that of reported systems with [Ru(bpy)3]2+ participation in similar conditions. Mechanism studies revealed efficient photo-induced charge separation is achieved in the system and CO2 reduction tends to occur on [Ru(bpy)3]2+.

4.
Nanotechnology ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32018234

RESUMO

For the excellent optical property and unique electronic structure, halide perovskite has been employed as a photocatalyst for CO2 photoreduction. However, the photocatalytic performance is relatively poor. Herein, we demonstrate a new strategy with Mn-doped CsPb(Br/Cl)3 mixed-halide perovskites as catalysts to enhance the efficiency of CO2 photoreduction. Via tuning the content of Mn, a serial of CsPb(Br/Cl)3:Mn perovskites are obtained and show high efficiency in CO2 conversion to CO and CH4. Especially, for the optimum catalyst of sample, the yields of CO and CH4 are up to 1917 µmol/g and 82 µmol/g which are 14.2 and 1.4 folds higher than the ones of CsPbBr3. This work provides new insights to improve the reactivity of perovskites in CO2 photoreduction.

6.
Dalton Trans ; 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-32083270

RESUMO

We synthesized a novel MOF with an sqc1575 topology as an ideal host matrix that exhibits luminescence energy transfer with polycyclic aromatic hydrocarbons (PAHs). What's more, the PAHs@MOF composites display an interesting quenching behavior in the presence of the electron donor triethanolamine (TEOA). We report for the first time that the well-defined porosity of a luminescent MOF enables it to serve as a host matrix for encapsulating chromophoric PAH molecules to modulate luminescence properties, and further exploit its reductive quenching properties by using a photocatalytic sacrificial electron donor.

7.
FASEB J ; 34(2): 2524-2540, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31908026

RESUMO

The main mechanism of hyaluronidase 1(HYAL-1) in the development of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) was unknown. In this study, a comprehensive inventory of pre-, intra-, and postoperative clinical and biological data of two cohorts (62 pancreatic cancer [PCa] and 111 pancreatic ductal adenocarcinoma [PDAC]) which could induce POPF were retrospectively analyzed. Then, a total of 7644 genes correlated with HYAL-1 was predicted in PDAC tissues and the enriched pathway, kinase targets and biological process of those correlated genes were evaluated. Finally, a mouse pancreatic fistula (PF) model was first built and in vitro studies were performed to investigate the effects of HYAL-1 on PF progression. Our data indicated that preoperative serum HYAL-1 level, pancreatic fibrosis score, and pancreatic duct size were valuable factors for detecting POPF of Grade B and C. The serum HYAL-1 level of 2.07 mg/ml and pancreatic fibrosis score of 2.5 were proposed as the cutoff values for indicating POPF. The bioinformatic analysis and in vitro and in vivo studies demonstrated that HYAL-1 facilitates pancreatic acinar cell autophagy via the dephosphorylation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and signal transducers and activators of transcription 3 (STAT3) signaling pathways, which exacerbate pancreatic secretion and inflammation. In summary, the preoperative serum HYAL-1 was a significant predictor for POPF in patients who underwent PD. Tumor-induced HYAL-1 is one of core risk in accelerating PF and then promoting pancreatic secretion and acute inflammation response through the AMPK and STAT3-induced autophagy.

8.
Chem Commun (Camb) ; 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31994540

RESUMO

A nanosized Ta/W mixed addendum polyoxometalate (Cs12K3H7[MnTa18Si6W54O231]·61H2O) based on the unprecedented {MnTa18} cluster was fabricated successfully under hydrothermal conditions. An excellent electrochemical performance of this compound was found in lithium-ion batteries (LIBs) as an anode material. The discharge capacity was 829.9 mA h g-1 at a current density of 100 mA g-1 in the first cycle and stable at 428.4 mA h g-1 after 100 cycles, which suggests the potential application of this new compound in LIBs.

9.
Chem Soc Rev ; 49(3): 765-838, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31942586

RESUMO

The development of metal complexes for optoelectronic applications is a fertile area of research. In contrast to the rigorous development of mononuclear metal complexes, dinuclear species have been less well studied and their fundamental chemistry and applications are under-explored. However, dinuclear species present special properties and functions compared with mononuclear species as a consequence of tuning the bridging ligands, the cyclometalated ligands or the two metal centers. More recently, dinuclear species have enabled important breakthroughs in the fields of OLEDs, photocatalytic water splitting and CO2 reduction, DSPEC, chemosensors, biosensors, PDT, smart materials and so on. Here we present an overview of recent developments of dinuclear metal complexes, their multifunctional properties and their various applications. The relationship between structure and property of dinuclear species and important factors which influence device performance are discussed. Finally, we illustrate some challenges and opportunities for future research into dinuclear metal complexes. This review aims to provide an up-to-date summary and outlook of functional dinuclear metal complexes and to stimulate more researchers to contribute to this exciting interdisciplinary field.

10.
Dalton Trans ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31967144

RESUMO

Two new cucurbit[6]uril (CB[6])-based metal-organic rotaxane networks (MORNs) were successfully obtained by tuning the coordination sphere of metal copper clusters. Compounds 1 and 2 exhibited relatively high proton conductivity at 85 °C and 97% relative humidity (RH), providing great promise for fuel cell electrolyte materials.

11.
J Hazard Mater ; 384: 121260, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31586912

RESUMO

A novel ternary hybrid nanoflake (GPZ) based on graphene oxide (GO), phenylphosphinic acid (PPA) and nano metal-organic framework (nano ZIF-8) particles has been designed and synthesized via a simple two-step strategy. GPZ shows high thermal stability and good compatibility with PLA matrix. When GPZ nanoflakes are added into PLA, the tensile strength and toughness of the PLA-4 with 2.0 wt% of GPZ reach 44.1 MPa and 86.0 MPa compared with 30.0 MPa and 12.8 MPa of pure PLA owing to the good dispersion of GPZ in PLA matrix and their reinforcing effects. The incorporation of GPZ also dramatically enhances the flame retardancy of PLA and the PHRR of PLA-4 with 2.0 wt% of GPZ achieves about 316.2 W/g, which is decreased by 39.5% relative to 523.0 W/g of pure PLA, respectively. The LOI of PLA-4 is 27.0%, increasing about 31.7% compared to 20.5% of pure PLA. Meanwhile, the HRR and THR in the cone calorimeter test curves for the PLA nanocomposites have also been evidently reduced. The TG-IR is applied to characterize the pyrolysis gaseous products and volatile components are suppressed with addition of GPZ. The SEM, Raman and XPS results of char residues show that a protective graphitized char layer plays a major role in improving the flame retardancy, which mainly because of the catalytic and cross-linking effects of GO, nano ZIF-8 and PPA during combustion of PLA nanocomposites.

12.
Chemistry ; 26(12): 2735-2740, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-31808202

RESUMO

At present, the fixation of CO2 always requires it to be extracted from the atmosphere first, which leads to more energy consumption. Thus, direct photoreduction of low-concentration CO2 to useful chemicals (e.g., syngas) under sunlight is significant from an energy-saving and environmentally friendly perspective. Here, the design and fabrication of a [Ru(bpy)3 ]/[Co20 Mo16 P24 ] composite is demonstrated for visible-light-driven syngas production from diluted CO2 (3-20 %) gas with a high yield of approximately 1000 TONs (turnover number of syngas). This activity is an order of magnitude higher than the reported system with [Ru(bpy)3 ]2+ participation. With evidence from ultrafast transient absorption, GC-MS, 1 H NMR spectroscopy and in situ transient photovoltage tests, a clear and fundamental understanding of the highly efficient photoreduction of CO2 by the [Ru(bpy)3 ]/[Co20 Mo16 P24 ] composite is achieved. Making use of the structure and property designable polyoxometalates towards the photo-fixation of CO2 is a conceptually distinct and commercially interesting strategy for making useful chemicals and environmental protection.

13.
Front Neurosci ; 13: 1225, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31798406

RESUMO

Aim: Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive and safe technique for treatment of central and peripheral nerve injury. In recent years, this technique has been widely used in clinic, and an increasing number of studies have reported its mechanisms. In this study, we investigated the mechanisms of rTMS-mediated autophagy flux in human bone mesenchymal stromal cells (BMSCs). Methods: A frequency of 50 Hz was employed. Cells were divided into five groups: (1) normal, (2) sham, (3) 0.5 T, (4) 1.0 T, and (5) 1.5 T. Cells were stimulated for 20 min/day. The levels of p62, LC3-II/I, phosphorylated extracellular signal-regulated kinase (p-ERK), ERK, phosphorylated-AKT (p-AKT), AKT, phosphorylated mammalian target of rapamycin (p-mTOR), mTOR, phosphorylated protein kinase A (p-PKA), PKA, phosphorylated epidermal growth factor receptor (p-EGFR), EGFR, Nanog, Oct4, Sox2, and NMDA receptor (NMDAR1) were investigated by western blotting. Intracellular calcium (Ca2+) levels were quantified by flow cytometry. p62 and LC3 expression was also assessed by immunofluorescence analysis. Results: In the 0.5 T group, rTMS increased the expression of LC3-II/I, p-ERK/ERK, and NMDAR1 and decreased the levels of p62 and p-mTOR/mTOR than in the normal group. The ratio of p-AKT/AKT, p-PKA/PKA, and p-EGFR/EGFR and the expression of Nanog, Oct4, and Sox2 remained unchanged. Immunofluorescence analysis revealed colocalization of p62 with LC3 puncta, and flow cytometry analysis displayed that Ca2+ levels were elevated. However, in the 1.0 and 1.5 T groups, no changes in the expression of these autophagy markers were observed. Conclusion: In the 0.5 T group, high-frequency rTMS can induce autophagy through NMDAR-Ca2+-ERK-mTOR signaling in BMSCs. In the 1.0 and 1.5 T groups, autophagy is not activated.

14.
Artigo em Inglês | MEDLINE | ID: mdl-31714245

RESUMO

Transcranial infrared laser stimulation (TILS) is a promising noninvasive intervention for neurological diseases. Though some experimental work has been done to understand the mechanism of TILS, the reported statistical analysis of data is quite simple and could not provide a comprehensive picture on the effect of TILS. This study learns the effect of TILS on hemodynamics of the human brain from experimental data using longitudinal data analysis methods. Specifically, the repeated measures analysis of variance (ANOVA) is first applied to confirm the significance of the TILS effect and its characteristics. Based on that, two parametric mixed-effect models and non-parametric functional mixed-effect model are proposed to model the population-level performance and individual variation of this effect. Interpretation on the fitted models are provided, and comparison of the three proposed models in terms of their fitting and prediction performance is made to select the best model. According to the selected model, TILS increases the concentration of oxygenated hemoglobin in the brain and this effect sustains even after the treatment stops. Also, there is considerable variation among individual responses to TILS.

15.
Chemistry ; 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31705556

RESUMO

Multi-component tungsten carbide-based hybrid materials featuring different heteroatom dopants coated with X,N dual-doped carbon layers (X/W2 C@X,N-C, XWXNC) were prepared by selecting Keggin-type polyoxometalates (POMs) (NH4 )n [XW12 O40 ] (X=Co, Si, Ge, B, and P) and dicyandiamide (DCA) as precursors. The electrocatalytic activity of these nanocomposites as counter electrode (CE) catalysts for dye-sensitized solar cells (DSSCs) was systematically investigated. Structure characterizations show that X,N heteroatoms were successfully introduced into the W2 C and carbon frameworks. The obtained X,N dual-doped carbon layers were modified and loaded with W2 C nanoparticles, promoting the improvement of catalytic performance by a synergistic effect. The consequence of photoelectric conversion efficiency (PCE) is CoWCoNC (6.68 %)>SiWSiNC (6.56 %)>GeWGeNC (6.49 %)>BWBNC (6.45 %)>PWPNC (6.20 %)>WNC (6.05 %). With the increase in electronegativity of the dopants, the photovoltaic performance decreases in a reverse order. This work provides a shortcut to the rational design of highly efficient and cost-effective catalysts for DSSCs.

16.
Chemistry ; 25(67): 15326-15332, 2019 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-31568591

RESUMO

A new supramolecular nanocage, VMOP-31, based on polyoxovanadate as the molecular building block, has been designed and synthesized under solvothermal conditions. The structure of VMOP-31 was determined by single-crystal and powder X-ray diffraction, FTIR spectroscopy, UV/Vis spectrophotometry, and thermogravimetric analysis. The nanocage exhibits octahedral geometry and is constructed of six {V5 O9 Cl(COO)4 } at the vertices and eight TATB (H3 TATB=4,4',4''-(s-triazine-2,4,6-triyl)tribenzoic acid) ligands on the faces. Impressively, VMOP-31 exhibited high efficiency in the inhibition of cell growth of solid tumors, such as human liver cancer cells SMMC-7721, and superior results in the treatment of liver tumors in mice compared with classic cisplatin. Detailed studies revealed that the potential mechanism of cell death induced by VMOP-31 involves cell cycle arrests, DNA damage, and subsequent apoptosis. Moreover, VMOP-31 exhibited negligible side effects in the mice compared with cisplatin. To the best of our knowledge, VMOP-31 is the first supramolecular nanocage applied to hepatic tumors both in vitro and in vivo.

17.
Chemistry ; 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31631411

RESUMO

Hybrid materials have obtained well-deserved attention for energy storage devices, because they show high capacitances and high energy densities induced by the synergistic effect between complementary components. Polyoxometalate-based metal-organic frameworks (POMOFs) possess the abundant redox-active sites and ordered structures of polyoxometalates (POMs) and metal-organic frameworks (MOFs), respectively. Here, an asymmetric supercapacitor (ASC) NENU-5/PPy/60//FeMo/C was fabricated in which both its electrodes are prepared from POMOF precursors. A typical POMOF material, NENU-5, was first connected with polypyrrole (PPy) through electrodeposition to form the cathode material NENU-5/PPy. Another representative POMOFs material, PMo12 @MIL-100, was carbonized to obtain the anode material FeMo/C. Cathode NENU-5/PPy exhibited an extraordinary capacitance of 508.62 F g-1 (areal capacitance: 2034.51 mF cm-2 ). In addition, anode FeMo/C shows excellent cyclic stability attributed to its unique structure. Finally, benefiting from the outstanding capacitances and structural merits of the anode and cathode, assembled asymmetric supercapacitor NENU-5/PPy/60//FeMo/C achieves an energy density of 1.12 mWh cm-3 at a power density output of 27.78 mW cm-3 , as well as a notable life of 10 000 cycles with an capacity retention of 80.62 %. Thus, the unique ASC is strongly competitive in high capacitance, long cycle life, and high energy-required energy storage devices.

18.
Chem Commun (Camb) ; 55(82): 12328-12331, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31556436

RESUMO

A newly prepared tetraphenylethylene-based (TPE-based) covalent organic polymer (COP) named COP-1 exhibits high selectivity for sensing Fe3+ and the limit of detection (LOD) for Fe3+ is 0.42 µM, which is lower than the reported metal-free porous polymers. Furthermore, a WLED is fabricated and the CIE coordinates are (0.32, 0.33), very close to pure white light. The COP-1 shows potential applications in biosensors of Fe3+ and preparation of WLEDs.

19.
Inorg Chem ; 58(19): 12895-12904, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31532221

RESUMO

The reaction of mid-lanthanide (Ln) ions with the preformed {Se6W39} precursor under reasonably acidic aqueous conditions in the presence of organic amine cations results in an unprecedented nanoscale lanthanide-functionalized polyoxotungstate family, which are rare examples of mid-lanthanide-containing selenotungstates. (C4H10NO)9Na3[Dy3Se3.5W30O107.5(H2O)10]·22H2O (1) and (NH4)3(C2H8N)Na2[Dy4Se6W38O132(H2O)26(OH)6]·18H2O (2) reveal a trimeric Keggin assembly and a cyclic {Se6W38}-based chain, respectively, whereas (NH4)4Na8[Gd4Se6W48O166(H2O)20(OH)4]·21H2O (3) and (NH4)9(C2H8N)4Na5[Ln6Se6W58O202(H2O)20(OH)4]·58H2O (4; Ln = Gd, Tb, or Dy) are a few examples of polyoxometalates consisting of both classical Keggin and Wells-Dawson building blocks, and (NH4)4(C2H8N)5Na13[Ln4Se8W56O196(H2O)x(OH)10]·40H2O (5; Ln = Gd, Tb, or Dy; x = 12 for Gd and Tb and 10 for Dy) features the largest "pure" Wells-Dawson selenotungstate {Se8W56} bearing a length of 3.73 nm. A library of Se-templated species involving the first reported Keggin {α-SeW8} and Wells-Dawson {α-Se2W16} building blocks as well as some decisive assembly factors during the synthesis is responsible for these architectures. All of the compounds were structurally characterized in the solid and solution by single-crystal X-ray diffraction, IR, thermogravimetric-differential thermal analysis, and electrospray ionization mass spectrometry. Magnetic properties indicate that 1 and 4-Dy show probable single-molecule-magnet behavior with obvious frequency dependence, whereas 3 and 4-Gd present the antiferromagnetic interactions between the GdIII centers.

20.
Dalton Trans ; 48(37): 14115-14121, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31495846

RESUMO

CsPbBr3 is widely used in solar cells and LEDs for its excellent photoelectric properties that are also attractive for CO2 photoreduction, but it is less used in the photocatalytic reduction of CO2 mainly owing to its limited charge separation efficiency. To alleviate this issue, herein, all-inorganic orthorhombic CsPbBr3 was combined with graphitic carbon nitride (g-C3N4) and the resultant composite (CsPbBr3@g-C3N4) showed enhanced activity in CO2 photoreduction. Under the irradiation of AM1.5 filter for 12 h, CO2 was converted into CH4 and CO with high selectivity to methane (91%) and the total amount of gaseous products up to ∼300 µmol g-1. This reactivity is 6-fold and 4-fold higher than that of pure g-C3N4 and CsPbBr3, respectively. CsPbBr3@g-C3N4 also shows excellent catalytic activity at low concentrations of CO2. Studies of energy band level and steady-state and transient photoluminescence spectroscopy indicated that the incorporation of CsPbBr3 and g-C3N4 increases charge separation, which may result in sharply enhanced catalytic efficiency. This study has provided opportunities for the combination of CsPbBr3 and other semiconductor catalysts for the photocatalytic reduction of CO2.

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