H5N1 avian influenza virus (AIV) has emerged as a pathogenic entity for a variety of species, including humans, in recent years. Here we report an outbreak among migratory birds on Lake Qinghaihu, ...China, in May and June 2005, in which more than a thousand birds were affected. Pancreatic necrosis and abnormal neurological symptoms were the major clinical features. Sequencing of the complete genomes of four H5N1 AIV strains revealed them to be reassortants related to a peregrine falcon isolate from Hong Kong and to have known highly pathogenic characteristics. Experimental animal infections reproduced typical highly pathogenic AIV infection symptoms and pathology.
We study the process e^{+}e^{-}→Λ_{c}^{+}Λover ¯_{c}^{-} at twelve center-of-mass energies from 4.6119 to 4.9509 GeV using data samples collected by the BESIII detector at the BEPCII collider. The ...Born cross sections and effective form factors (|G_{eff}|) are determined with unprecedented precision after combining the single and double-tag methods based on the decay process Λ_{c}^{+}→pK^{-}π^{+}. Flat cross sections around 4.63 GeV are obtained and no indication of the resonant structure Y(4630), as reported by Belle, is found. In addition, no oscillatory behavior is discerned in the |G_{eff}| energy dependence of Λ_{c}^{+}, in contrast to what is seen for the proton and neutron cases. Analyzing the cross section together with the polar-angle distribution of the Λ_{c}^{+} baryon at each energy point, the moduli of electric and magnetic form factors (|G_{E}| and |G_{M}|) are extracted and separated. For the first time, the energy dependence of the form factor ratio |G_{E}/G_{M}| is observed, which can be well described by an oscillatory function.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
Sea-land and mount-valley circulations are the dominant mesoscale synoptic systems affecting the Beijing area during summertime. Under the influence of these two circulations, the prevailing wind is ...southwesterly from afternoon to midnight, and then changes to northeasterly till forenoon. In this study, surface ozone (O3), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxide (NOx) and non-methane hydrocarbons (NMHCs) were measured at four sites located along the route of prevailing wind, including two upwind urban sites (Fengtai "FT" and Baolian "BL"), an upwind suburban site (Shunyi "SY") and a downwind rural site (Shangdianzi "SDZ") during 20 June–16 September 2007. The purpose is to improve our understanding of ozone photochemistry in urban and rural areas of Beijing and the influence of urban plumes on ozone pollution in downwind rural areas. It is found that ozone pollution was synchronism in the urban and rural areas of Beijing, coinciding with the regional-scale synoptic processes. Due to the high traffic density and local emissions, the average levels of reactive gases NOx and NMHCs at the non-rural sites were much higher than those at SDZ. The level of long-lived gas CO at SDZ was comparable to, though slightly lower than, at the urban sites. We estimate the photochemical reactivity (LOH and the ozone formation potential (OFP) in the urban (BL) and rural (SDZ) areas using measured CO and NMHCs. The OH loss rate coefficient (LOH by total NMHCs at the BL and SDZ sites are estimated to be 50.7 s-1 and 15.8 s-1, respectively. While alkenes make a major contribution to the LOH, aromatics dominate OFP at both urban and rural sites. With respect to the individual species, CO has the largest ozone formation potential at the rural site, and at the urban site aromatic species are the leading contributors. While the O3 diurnal variations at the four sites are typical for polluted areas, the ozone peak values are found to lag behind one site after another along the route of prevailing wind from SW to NE. Intersection analyses of trace gases reveal that polluted air masses arriving at SDZ were more aged with both higher O3 and Ox concentrations than those at BL. The results indicate that urban plume can transport not only O3 but its precursors, the latter leading more photochemical O3 production when being mixed with background atmosphere in the downwind rural area.
Aims
Cucumber angular leaf spot caused by Pseudomonas syringae pv. lachrymans (Psl) is an important and destructive disease worldwide, and no effective technique has been developed for the control of ...the pathogen. Detection of infection or latent in cucumber plants is critical to evaluate disease progress and strengthening management to avoid a serious epidemic in the fields. In this paper, we developed a rapid and sensitive method for detection of Psl using an isothermal method known as loop‐mediated amplification (LAMP).
Methods and Results
A set of six primers was designed to amplify the gene coding for the hrpZ, and conditions for detection were optimized to complete in 60 min at 67°C, and the amplification were confirmed through gel electrophoresis or visually inspected using calcein stain. The specificity of LAMP primers set was widely validated on Psl and nontarget strains. In sensitivity testing, LAMP allowed detection as low as 104 CFU per ml bacterial cells without DNA extraction. The novel method was also applied for detecting Psl in infected cucumber leaves, and even the early onset of disease can be detected by the assay.
Conclusions
This study confirmed that the novel developed LAMP assay is an easy, rapid and sensitive method for the detection of Psl in infected leaves.
Significance and Impact of the Study
The method is suitable for direct detection of Psl without strain enrichment and complex DNA extraction from samples in the field, and hence it has the capability to be used for on‐site disease diagnosis and field surveys.
► Complete accounting of net GWP and GHGI including soil carbon change of a rice cropping system under 5 different management practices. ► Three integrated soil crop system management strategies ...(ISSMs) were examined for mitigating GHGs, increasing yield and NUE in rice agriculture. ► Two ISSMs are advocated for rice agriculture due to less net GWPs and GHGIs, while another ISSM need more work with increased net GWPs.
The impact of management practices on the net global warming potential (GWP) and greenhouse gas intensity (GHGI) of rice cropping systems is not well documented. A field experiment was established in 2009 to gain insight into the net ecosystem carbon budget and the net GWP and GHGI on the crop seasonal scale over two cycles of rice–wheat rotations. With the local farmer's practices (FP) as the control, three integrated soil–crop system management (ISSM) practices at different nitrogen (N) application rates were established – ISSM-N1, ISSM-N2 and ISSM-N3 – for improvement of rice yield and agronomic nitrogen use efficiency (NUE). Compared with the FP, the rice yields significantly increased by 8.2%, 18% and 31%, while the agronomic NUE increased by 68%, 74% and 99% for ISSM-N1, ISSM-N2 and ISSM-N3, respectively. Within the three ISSM practices averaged over the two cycles, the soil organic carbon sequestration potentials, CH4 and N2O emissions were estimated to be 0.089–0.67tCha−1yr−1, 166–288kgCH4Cha−1yr−1 and 4.27–5.47kgN2ONha−1yr−1, respectively. Compared to the net GWPs (8.36tCO2eqha−1yr−1) and GHGI (0.58kgCO2eqkg−1 grain) from the FP, the ISSM-N1 and ISSM-N2 reduced both the net GWPs and GHGIs to some extent, indicating that GHG mitigation can be simultaneously achieved with improved food production and NUE. Although it produced similar GHGIs, the ISSM-N3 increased the net GWPs by 16% compared to the FP, indicating that more research is required on ISSMs for mitigating GHGs to further increase the grain yield and NUE in rice agriculture.
Based on electron-positron collision data collected with the BESIII detector operating at the Beijing Electron-Positron Collider II storage rings, the value of ...R≡σ(e^{+}e^{-}→hadrons)/σ(e^{+}e^{-}→μ^{+}μ^{-}) is measured at 14 center-of-mass energies from 2.2324 to 3.6710 GeV. The resulting uncertainties are less than 3.0% and are dominated by systematic uncertainties.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
Two-dimensional topological insulators with a large bulk band gap are promising for experimental studies of quantum spin Hall effect and for spintronic device applications. Despite considerable ...theoretical efforts in predicting large-gap two-dimensional topological insulator candidates, none of them have been experimentally demonstrated to have a full gap, which is crucial for quantum spin Hall effect. Here, by combining scanning tunneling microscopy/spectroscopy and angle-resolved photoemission spectroscopy, we reveal that ZrTe5 crystal hosts a large full gap of ∼100meV on the surface and a nearly constant density of states within the entire gap at the monolayer step edge. These features are well reproduced by our first-principles calculations, which point to the topologically nontrivial nature of the edge states.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
We present an analysis of the process ψ(3686)→Ω^{-}Ωover ¯^{+} (Ω^{-}→K^{-}Λ, Ωover ¯^{+}→K^{+}Λover ¯, Λ→pπ^{-}, Λover ¯→pover ¯π^{+}) based on a dataset of 448×10^{6} ψ(3686) decays collected with ...the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process ψ(3686)→Ω^{-}Ωover ¯^{+} and the decay parameters of the subsequent decay Ω^{-}→K^{-}Λ (Ωover ¯^{+}→K^{+}Λover ¯) are measured for the first time by a fit to the angular distribution of the complete decay chain, and the spin of the Ω^{-} is determined to be 3/2 for the first time since its discovery more than 50 years ago.
Full text
Available for:
CMK, CTK, FMFMET, NUK, UL
Hypoxia has been shown to inhibit reactive oxygen species (ROS) production in nucleus pulposus (NP) cells. The TP53-induced glycolysis and apoptosis regulator (TIGAR) has been reported to suppress ...oxidative stress. We sought to explore the role of TIGAR in the effect of hypoxia on ROS production and apoptosis.
An intervertebral disc degeneration (IDD) model of Sprague–Dawley (SD) rat caudal spine was established by puncturing the Co6–7 disc. TIGAR expression was detected by immunohistochemistry and western blotting in human and SD rat NP tissues of degenerated discs. Rat primary NP cells treated with hypoxia and cobalt chloride (CoCl2) were analyzed by western blotting for TIGAR expression. After TIGAR silence with TIGAR siRNA transfection, apoptosis percentage, mitochondrial and total intracellular ROS levels were measured. H2O2 was used to further check the effects of TIGAR on oxidative stress. Finally, NADPH/NADP+ and GSH/GSSH ratio were examined after TIGAR silencing under hypoxic conditions and after H2O2 treatment.
A degree-dependent increase in TIGAR expression was observed in human and rat degenerated NP tissues. Hypoxia and hypoxia-inducer CoCl2 enhanced TIGAR and P53 expressions in rat NP cells. TIGAR silence reversed the inhibitory effects of hypoxia on intracellular and mitochondrial ROS production, as well as apoptosis percentage. However, TIGAR silence aggravated H2O2-induced ROS production. In addition, TIGAR increased NADPH/NADP+ and GSH/GSSH ratio in NP cells.
These results suggested that TIGAR appears to mediate the protective role of hypoxia on ROS production and apoptosis percentage by enhancing NADPH/NADP+ and GSH/GSSH ratio.
•Evolution of the passive film on DSS induced by chloride is directly visualized.•The passive film has a step-like unevenness at the austenite/ ferrite boundary.•Passive film on austenite has a more ...pronounced growth rate yielding lower interface.•Chloride ions attack mechanisms differ from austenite to ferrite phase.•Chloride induces a thicker Mo-rich passive film from the original Cr-rich film.
Passive films on duplex stainless steels are heterogeneous, with properties depending on the two-phase microstructure. Accordingly, the interaction of chloride ions with the passive films on either of the two phases ought to vary. These issues have been investigated by some indirect methods, not sufficiently nor directly corroborated by experimental evidence. Using aberration-corrected transmission electron microscopy, we simultaneously investigate the films on the ferrite and austenite phase near the phase boundary, as well as the film evolution in chloride-containing media. This study provides some virtual experimental insights into the features of chloride attack on the passive film of duplex alloys.
PDF
