| 1. |
- Ablikim, M., et al.
(författare)
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Observation of the Semileptonic Decay D-0 -> a(0)(980)(-)e(+)nu(e) and Evidence for D+ -> a(0)(980)(0)e(+)nu(e)
- 2018
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 121:8
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Tidskriftsartikel (refereegranskat)abstract
- Using an e(+)e(-) collision data sample of 2.93 fb(-1) collected at a center-of-mass energy of 3.773 GeV by the BESIII detector at BEPCII, we report the observation of D-0 -> a(0)(980)(-)e(+)nu(e) and evidence for D+ -> a(0)(980)(0)e(+)nu(e) with significances of 6.4 sigma and 2.9 sigma, respectively. The absolute branching fractions are determined to be B(D-0 -> a(0)(980)(-)e(+)nu(e)) x B(a(0)(980)(-) -> eta pi(-)) = [1.33(-0.29)(+0.33)(stat) +/- 0.09(syst)] x 10(-4) and B(D+ -> a(0)(980)(0)e(+)nu(e)) x B(a(0)(980)(0) -> eta pi(0)) = [1.66(-0.66)(+0.81)(stat) +/- 0.11(syst) x 10(-4). This is the first time the a(0)(980) meson has been measured in a D-0 semileptonic decay, which would open one more interesting page in the investigation of the nature of the puzzling a(0)(980) states.
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| 2. |
- Farooq, U., et al.
(författare)
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Efficient transformation in characteristics of cations supported-reduced graphene oxide nanocomposites for the destruction of trichloroethane
- 2017
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Ingår i: Applied Catalysis A. - : Elsevier B.V.. - 0926-860X .- 1873-3875. ; 544, s. 10-20
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Tidskriftsartikel (refereegranskat)abstract
- Experiments were conducted to investigate the use of graphene-oxide supported metallic nanocomposites for improving the degradation of trichloroethane (TCA) by sodium percarbonate (SPC). Two methods of production, chemical reduction (CR) and solvo-thermal (ST), were tested for preparation of single (Fe) and binary (Fe-Cu) nanocomposites supported by reduced graphene oxide (rGO). A variety of analytical techniques including N2 adsorption Brunauer-Emmett-Teller (BET), x-ray diffraction (XRD), fourier-transfrom infrared spectroscopy (FTIR), and transmisison electron microscopy (TEM) were applied to characterize the physicochemical and microstructural properties of the synthesized nanocomposites. The characterization indicated that the CR method produced nanocomposites that comprised only mesoporous structure. Conversely, both micro and mesoporous structures were present for samples produced with the ST method. The synthesized single and bimetallic composites produced from the ST method showed higher surface areas, i.e. 93.6 m2/g and 119.2 m2/g as compared to the ones synthesized via the CR method, i.e. 13.8 m2/g and 38.0 m2/g respectively. The results of FTIR and XRD analyses confirmed that the ST method produced highly crystalline nanocomposites. SEM and TEM analysis validated that metallic particles with definite morphology well distributed on the surface of rGO. X-ray photoelectron spectroscopy (XPS) analysis confirmed the homogeneity nanocomposites and occurrence of variation in copper oxidation states during degradation process. EDS mapping validate the homogeneous distribution of Cu and Fe at reduced graphene oxide surface. The Fe-Cu/rGO (ST) activated SPC system effectively degraded TCA (92%) in 2.5 h at low nanocomposite dose compared to the Fe-Cu/rGO (CR) and only Fe, for which the maximum degradation efficiencies achieved were 81% and 34%. In conclusion, excellent catalytic characteristics were observed for the ST-synthesized single and bimetallic (Fe/rGO, Fe-Cu/rGO) catalysts. These catalysts were successful in improving the degradation of TCA via activated SPC.
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| 3. |
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| 4. |
- Sui, Y, et al.
(författare)
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Defense responses to short-term hypoxia and seawater acidification in the thick shell mussel Mytilus coruscus
- 2017
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- The rising anthropogenic atmospheric CO2 results in the reduction of seawater pH, namely ocean acidification (OA). In East China Sea, the largest coastal hypoxic zone was observed in the world. This region is also strongly impacted by ocean acidification as receiving much nutrient from Changjiang and Qiantangjiang, and organisms can experience great short-term natural variability of DO and pH in this area. In order to evaluate the defense responses of marine mussels under this scenario, the thick shell mussel Mytilus coruscus were exposed to three pH/pCO(2) levels (7.3/2800 [(mu atm, 7.7/1020 mu atm, 8.1/376 mu atm) at two dissolved oxygen concentrations (DO, 2.0, 6.0 mg L-1) for 72 h. Results showed that byssus thread parameters, such as the number, diameter, attachment strength and plaque area were reduced by low DO, and shell-closing strength was significantly weaker under both hypoxia and low pH conditions. Expression patterns of genes related to mussel byssus protein (MBP) were affected by hypoxia. Generally, hypoxia reduced MBP1 and MBP7 expressions, but increased MBP13 expression. In conclusion, both hypoxia and low pH induced negative effects on mussel defense responses, with hypoxia being the main driver of change. In addition, significant interactive effects between pH and DO were observed on shell-closing strength. Therefore, the adverse effects induced by hypoxia on the defense of mussels may be aggravated by low pH in the natural environments.
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| 5. |
- Huang, X. Z., et al.
(författare)
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Oxidative stress induced by titanium dioxide nanoparticles increases under seawater acidification in the thick shell mussel Mytilus coruscus
- 2018
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Ingår i: Marine Environmental Research. - 0141-1136. ; 137, s. 49-59
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Tidskriftsartikel (refereegranskat)abstract
- Biochemical responses of the mussel Mytflrn coruscus exposed to different concentrations of titanium dioxide nanoparticles (nano-Ti0(2)) (0, 2.5, 10mgL(-1)) and two pH levels (pH 8.1 and pH 7.3) for 14 days. Mussel responses were also investigated after a 7 days recovery period (pH 8.1 and no nanoparticle). Exposure to nanoTi0(2) led changes in antioxidant indexes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione (GSH)), biotransformation enzyme activity (GST) and malondialdehyde level (MDA) in gills and digestive glands. An increase in MDA level and a decrease in SOD and GSH activities were observed in gill of mussels exposed to 10 mg L-n1 nano-TiO2. This effect was more severe in mussels kept at pH 7.3 as compared to pH 8.1. A different response was observed in the digestive gland as SOD, CAT and GSH levels increased in mussels exposed to nano-TiO2. These contrasting results in digestive glands and gills were only evident at high concentration of nano-TiO2 and low pH. A 7 days recovery period was not sufficient to fully restore SOD, GPx, GST, GSH and MDA levels to levels before exposure to nano-TiO2 and low pH. Overall, our results confirmed that seawater acidification modulates effects of nanoparticles in mussels, and that gills are more sensitive to these stressors as compared with digestive glands.
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| 6. |
- Lin, X., et al.
(författare)
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Positioning for the Internet of Things : A 3GPP Perspective
- 2017
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Ingår i: IEEE Communications Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 0163-6804 .- 1558-1896. ; 55:12, s. 179-185
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Tidskriftsartikel (refereegranskat)abstract
- Many use cases in the Internet of Things (IoT) will require or benefit from location information, making positioning a vital dimension of the IoT. The 3GPP has dedicated a significant effort during its Release 14 to enhance positioning support for its IoT technologies to further improve the 3GPPbased IoT eco-system. In this article, we identify the design challenges of positioning support in LTE-M and NB-IoT, and overview the 3GPP's work in enhancing the positioning support for LTE-M and NB-IoT. We focus on OTDOA, which is a downlink based positioning method. We provide an overview of the OTDOA architecture and protocols, summarize the designs of OTDOA positioning reference signals, and present simulation results to illustrate the positioning performance.
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| 7. |
- Sui, Y., et al.
(författare)
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Combined effects of short-term exposure to elevated CO2 and decreased O2 on the physiology and energy budget of the thick shell mussel Mytilus coruscus
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535. ; 155, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- Hypoxia and ocean acidification are two consequences of anthropogenic activities. These global trends occur on top of natural variability. In environments such as estuarine areas, short-term acute pH and O2 fluctuations are occurring simultaneously. The present study tested the combined effects of short-term seawater acidification and hypoxia on the physiology and energy budget of the thick shell mussel Mytilus coruscus. Mussels were exposed for 72 h to six combined treatments with three pH levels (8.1, 7.7 and 7.3) and two dissolved oxygen (DO) levels (2 mg L-1, 6 mg L-1). Clearance rate (CR), food absorption efficiency (AE), respiration rate (RR), ammonium excretion rate (ER), O:N ratio and scope for growth (SFG) were significantly reduced, and faecal organic dry weight ratio (E) was significantly increased at low DO. Low pH did not lead to a reduced SFG. Interactive effects of pH and DO were observed for CR, E and RR. Principal component analysis (PCA) revealed positive relationships among most physiological indicators, especially between SFG and CR under normal DO conditions. These results demonstrate that Mytilus coruscus was sensitive to short-term (72 h) exposure to decreased O2 especially if combined with decreased pH levels. In conclusion, the short-term oxygen and pH variation significantly induced physiological changes of mussels with some interactive effects. © 2016 Elsevier Ltd.
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| 8. |
- Sui, Y. M., et al.
(författare)
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Antioxidant response of the hard shelled mussel Mytilus coruscus exposed to reduced pH and oxygen concentration
- 2017
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Ingår i: Ecotoxicology and Environmental Safety. - : Elsevier BV. - 0147-6513. ; 137, s. 94-102
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Tidskriftsartikel (refereegranskat)abstract
- Ocean acidification (OA) and hypoxic events are increasing worldwide problems, their interactive effects have not been well clarified, although their co-occurrence is prevalent. The East China Sea (the Yangtze River estuary area) suffers from not only coastal hypoxia but also pH fluctuation, representing an ideal study site to explore the combined effect of OA and hypoxia on marine bivalves. We experimentally evaluated the antioxidant response of the mussel Mytilus coruscus exposed to three pH levels (8.1, 7.7 and 7.3) at two dissolved oxygen (DO) levels (2.0 mg L-1 and 6.0 mg L-1) for 72 h. Activities of superoxide dismutase, catalase, glutathione peroxidase, acid phosphatase, and alkaline phosphatase and levels of malondialdehyde were measured in gills and hemolymph. All enzymatic activities in hemolymph and gills followed a similar pattern throughout the experiment duration. Generally, low DO showed greater effects on enzyme activities than elevated CO2. Significant interactions between DO, pH and time were only observed at superoxide dismutase and catalase in both tissues. PCA revealed positive relationships between most enzyme activities in both gills and hemolymph with the exception of alkaline phosphatase activity and the level of malondialdehyde in the hemolymph. Overall, our results suggested that decreased pH and low DO induced similar antioxidant responses in the hard shelled mussel, and showed an additive effect on most enzyme activities. The evaluation of multiple environmental stessors, a more realistic scenario than single ones, is crucial to predict the effect of future global changes on coastal species and our results supply some insights on the potential combined effects of reduced pH and DO on marine bivalves.
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