Promising lanthanide-doped double molybdates KYb(MoO4)2 phosphors for highly efficient upconversion luminescence and temperature sensing.

Here we report the highly efficient upconversion luminescence (UCL) and optical temperature sensing based on the novel host of KYb(MoO4)2 doped with trivalent lanthanide (Ln3+) ions at 980 nm excitation. The high Yb3+ concentration and unique ordered layer structure in KYb(MoO4)2 host are beneficial for the enhancement of UCL efficiency by improving the absorption and the negative migration of excitation energy. Ho3+, Er3+, and Tm3+ ions were selected to singly dope the KYb(MoO4)2 host, achieving three primary colors of red, green, blue UCL, respectively. At the optimal doping concentration, the blue upconversion quantum yield (UCQY) of the KYb(MoO4)2: 1.0%Tm3+ phosphor reaches 0.13%, which is rare for the Tm3+-doped oxides. By leveraging the efficient blue light, we achieved high-brightness white UCL by co-doping Ho3+ in KYb(MoO4)2: Tm3+. Furthermore, the temperature sensing performance of the KYb(MoO4)2: Tm3+, Ho3+ phosphors operating within the first biological window (BW-I) was evaluated based on a thermo-responsive fluorescence intensity ratio (FIR) of far-red to near-infrared (NIR) emission from completely separated 3F2,3/3H4 → 3H6 transitions of Tm3+. At the excitation of 980 nm, the maximum absolute and relative sensitivities were determined as 0.25 × 10-3 K-1 at 673 K and 2.84% K-1 at 303 K, respectively. These results indicate that the double alkali-rare-earth molybdate KYb(MoO4)2 can be used as a promising host to achieve highly efficient UCL and temperature sensing, suggesting potential applications in the fields of anti-counterfeiting, displays, and non-contact temperature sensors.

One-Step Synthesis of Self-Supported Ni3S2/NiS Composite Film on Ni Foam by Electrodeposition for High-Performance Supercapacitors.

Herein, a facile one-step electrodeposition route was presented for preparing Ni3S2/NiS composite film on Ni foam substrate (denoted as NiSx/NF). The NiSx granular film is composed of mangy interconnected ultra-thin NiSx nanoflakes with porous structures. When applied as electrodes for supercapacitors, the ultra-thin nanoflakes can provide more active sites for redox reaction, and the interconnected porous structure has an advantage for electrolyte ions to penetrate into the inner space of active materials quickly. As expected, the obtained NiSx/NF sample exhibited high gravimetric capacitance of 1649.8 F·g-1 and areal capacitance of 2.63 F·cm-2. Furthermore, a gravimetric capacitance of 1120.1 F·g-1 can be maintained at a high current density of 20 mA·cm-2, suggesting a good rate capability. The influence of the different molar ratios of electrodeposition electrolyte (NiNO3 and thiourea) on the morphology and electrochemical properties of NiSx/NF sample was investigated to provide an optimum route for one-step electrodeposition of Ni3S2/NiS composite film. The outstanding performance indicated the Ni3S2/NiS composite film on Ni foam has great potential as an electrode material for supercapacitors.

Degradation of the UV-filter benzophenone-3 in aqueous solution using persulfate activated by heat, metal ions and light.

The goals of this study were to bring forward new data and insights into the effect of activation methods, operational variables and reaction pathways during sulfate radicals-based oxidation of benzophenone-3 (BP-3) in aqueous solution. Heat, transition metal ions (Fe2+, Cu2+, Co2+), UV and visible light irradiation were used to activate persulfate (PS) to degrade BP-3. The results showed that these three activation methods can remarkably enhance BP-3 removal efficiency. Under the conditions of [BP-3]0: [PS]0 = 1: 500, pH = 7.0, and 40 °C, complete removal of BP-3 (1.31 µM) was observed in 3 h. In the pH range of 3.0-9.0, the degradation of BP-3 decreased with increasing pH. Increasing the PS dosage accelerated the reaction, while the presence of humic acid (HA) significantly inhibited the efficiency of BP-3 removal. Based on electron paramagnetic resonance (EPR) and radical quenching studies, sulfate and hydroxyl radicals contributed to the oxidation process. According to the evolution of BP-3 and its 7 by-products, as well as frontier electron densities (FED) calculation, two routes were proposed involving hydroxylation, demethylation and direct oxidation. On the whole, this work is a unique contribution to the systematic elucidation of BP-3 removal by PS.

Fast removal of the antibiotic flumequine from aqueous solution by ozonation: Influencing factors, reaction pathways, and toxicity evaluation.

As one of the first generation of fluoroquinolone antibiotics, flumequine (FLU) has been detected ubiquitously in surface waters and municipal wastewaters. In light of FLU's possible adverse effects on aquatic species, the removal of this antibiotic has received worldwide attention. In this study, the kinetics, transformation products, mechanisms and toxicity variations of the ozonation process for FLU were systematically determined. The possible effects of solution pH, addition of inorganic ions, dissolved organic matter, and tert-butyl-alcohol (a radical scavenger), as well as the type of water matrices on FLU removal by ozonation, were studied from the perspective of the degradation kinetics. The data obtained suggested that ozone can be used as an effective oxidant for the fast removal of FLU from natural waters. Using liquid chromatography-mass spectrometry, a total of thirteen transformation products of FLU during ozonation were identified, and their specific reaction mechanisms were also proposed. The degradation pathways involving the hydroxylation, decarboxylation and defluorination were tentatively proposed. Meanwhile, the generation of three low-molecular-weight carboxylic acids was also observed. In addition, the potential toxicity of the transformation mixtures of FLU by ozone was evaluated. Overall, this paper can be a unique contribution to the systematic elucidation of the ozonation process of this antibiotic in water.

Antioxidant defenses and histological changes in Carassius auratus after combined exposure to zinc and three multi-walled carbon nanotubes.

With the increasing applications of carbon nanotubes (CNTs) worldwide, considerable concerns have been raised regarding their inevitable releases into natural waters and ecotoxicity. It was supposed that CNTs may interact with some existing pollutants like zinc in aquatic systems and exhibit different effects when compared with their single treatments. However, data on their possible combined toxicity on aquatic species are still lacking. Moreover, the interactions of Zn with different functionalized CNTs may be distinct and thereby lead to diverse results. It is like that functional groups play a vital role in illustrating the differences in toxicity among various CNTs. In this study, the single and joint effects of multi-walled carbon nanotubes (MWCNTs) and two MWCNTs functionalized with carboxylation (COOH-MWCNTs) or hydroxylation (OH-MWCNTs) in the absence or presence of zinc (Zn) on antioxidant status and histopathological changes in Carassius auratus were evaluated. Synergistic effect was tentatively proposed for joint-toxicity action, which was supported by apparently observed oxidative stress and histopathological changes in joint exposure groups. The integrated biomarker response index was calculated to rank the toxicity order, from which the conclusion of synergistic effect was strengthened. Regarding differences among various CNTs, our data showed that OH-MWCNTs and COOH-MWCNTs were more stressful to fish than raw MWCNTs. This finding sustained that functionalization is an important factor in nanotoxicity, which may serve as clues for future design and application of CNTs. Overall, these results provided some valuable toxicological data on the joint effects of CNTs and heavy metals on aquatic species, which can facilitate further understanding on the potential impacts of other coexisting pollutants in the culture of freshwater fish.

Evaluation of single and joint toxicity of perfluorooctane sulfonate and zinc to Limnodrilus hoffmeisteri: Acute toxicity, bioaccumulation and oxidative stress.

Perfluorooctane sulfonate (PFOS) and zinc have been detected in aquatic environment widely. In order to study the combined effects of PFOS and Zn, a series of experiments was conducted to explore the acute mortality, bioaccumulation and antioxidant status of Limnodrilus hoffmeisteri. The acute toxicity was evaluated by calculating 24h-EC50 values, and it was observed that 24h-EC50 values in single and joint treatments decreased with decreasing pH value or increasing exposure concentration. Toxic unit analysis suggested that the combined effects of the PFOS+Zn binary mixture were mostly simple addition, with 8 groups showing synergism and only one group showing antagonism. The analysis of internal Zn and PFOS concentration showed that the possible interaction between Zn and PFOS can affect the bioaccumulation of the two chemicals in L. hoffmeisteri. In addition, oxidative stress status was assessed by measuring oxidation-related biochemical parameters such as superoxide dismutase, glutathione peroxidase and malondialdehyde, and the integrated biomarker response index was estimated to rank the toxicity order. Exposures to Zn and PFOS were found to evoke some changes in the antioxidant defense system, and a strong self-adaptive ability was noticed for L. hoffmeisteri after 10 d exposure.

C677T methylenetetrahydrofolate reductase gene polymorphism as a risk factor involved in venous thromboembolism: a population-based case-control study.

The aim of the current study was to investigate the possible correlation between the C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism and venous thromboembolism (VTE) in a population-based case-control study. Homocysteine (Hcy) was quantified by Abbott IMx immunoassay; screening for C677T MTHFR substitution was performed by polymerase chain reaction (PCR) and restriction analysis. The results from the two groups (440 patients and 440 controls) revealed that the frequency of T alleles and TT carriers was significantly higher in patients compared with that of the healthy controls. The plasma levels of Hcy in the VTE group (13.05±2.37 µmol/l) were significantly higher compared with those in the control group (11.94±2.03 µmol/l, P<0.001). The C677T MTHFR polymorphism is suggested to be associated with the risk for VTE. Plasma levels of Hcy were raised in individuals with the homozygous MTHFR 677TT genotype. In conclusion, the results of the current study suggest that hyperhomocysteinemia and the homozygous 677TT MTHFR genotype are risk factors for VTE.