We report the experimental results of the commissioning phase in the 10 PW laser beamline of the Shanghai Superintense Ultrafast Laser Facility (SULF). The peak power reaches 2.4 PW on target without the last amplifying during the experiment. The laser energy of 72 ± 9 J is directed to a focal spot of approximately 6 μm diameter (full width at half maximum) in 30 fs pulse duration, yielding a focused peak intensity around 2.0 × 1021 W/cm2. The first laser-proton acceleration experiment is performed using plain copper and plastic targets. High-energy proton beams with maximum cut-off energy up to 62.5 MeV are achieved using copper foils at the optimum target thickness of 4 μm via target normal sheath acceleration. For plastic targets of tens of nanometers thick, the proton cut-off energy is approximately 20 MeV, showing ring-like or filamented density distributions. These experimental results reflect the capabilities of the SULF-10 PW beamline, for example, both ultrahigh intensity and relatively good beam contrast. Further optimization for these key parameters is underway, where peak laser intensities of 1022–1023 W/cm2 are anticipated to support various experiments on extreme field physics.

In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.

We developed a bedside instrument to predict carbapenem resistance in complicated urinary tract infections. A model assigning weighted points for admission from an extended care facility (1), history of weight loss (1), early mechanical ventilation (1), age <50 years (2), male gender (3), catheter-associated urinary tract infection (4), prior antibiotics treatment (4), and prior carbapenem-resistant infection (8) exhibited good discrimination (C statistic, 0.721).

The triplite LiFeSO4F displays both the highest potential ever reported for an Fe-based compound, as well as a comparable specific energy with that of popular LiFePO4. The synthesis is still a challenge because the present approaches are connected with long time, special equipments or organic reagents, etc. In this work, the triplite LiFeSO4F powder was synthesized through an ambient two-step solid-state route. The reaction process and phase purity were analyzed, coupled with structure refinement and electrochemical test.

This paper presents an analytical study on the buckling of cylindrical shells with arbitrary circumferential thickness variations under external pressure. Firstly, based on the thin shell theory and separation of variables, corresponding ordinary differential equations of laterally pressured cylinders are obtained. Secondly, the general asymptotic formula of buckling load, which is in terms of thickness variation parameter up to arbitrary order, is derived by combining the perturbation method and Fourier series expansion. Thirdly, the effects of uniform and circumferential modal thickness variations on the buckling of cylindrical shells under external pressure are investigated, respectively, and the results agree well with those available in literature. Particularly, the buckling load reduction of cylinders with circumferential modal thickness variation obtained by the proposed method coincides with the numerical results presented by Gusic et al. This analytical method is applicable for evaluating the stability of laterally pressured cylindrical shells with arbitrary circumferential thickness variations, once the thickness variation is known.

The herbicide chlorsulfuron is commonly applied to cereals and may persist in alkaline soil long enough to damage subsequent sensitive crops. Sewage water, a potential source of the heavy metal cadmium (Cd), is used to irrigate agricultural soils in many developing countries. The current work evaluated the effects of the residual herbicide chlorsulfuron and Cd on maize seedlings, with particular attention to the mechanism of their action on plant growth. Maize seeds were planted in soil that had been sprayed with chlorsulfuron and Cd, after which residues in both seedlings and the soil were measured. The chlorsulfuron dose was correlated with the amount of residue found in seedlings but not in the soil. In all, 39 metabolites were identified in seedlings using the Automated Mass spectral Deconvolution and Identification System software program and the retention index method. The combination of chlorsulfuron and Cd significantly reduced multiple metabolites in the shikimate pathway, malic acid and citric acid production in the tricarboxylic acid cycle, and lactic acid, glucose, aspartic acid, asparagine and 3-glycerophosphoric acid production. In addition, chlorsulfuron caused an increase in multiple amino acids, including tyrosine, methionine and asparagine, and a marked decrease in caffeic and cinnamic acids (the secondary metabolites derived from the shikimate pathway and galactose). Finally, chlorsulfuron and Cd stress markedly increased shikimate acid, decreased 3-glycerophosphoric acid and caused negative correlations between the amounts of phenylalanine and tyrosine and those of quinic- and cinnamic-acid. In conclusion, chlorsulfuron and Cd did not have a synergistic effect on maize seedlings; rather, the combination of these pollutants had an antagonistic effect on some amino acids.

This study aimed to comprehensively evaluate factors that influence the likelihood of syphilis infection from risk-taking behaviours and medical conditions. A retrospective case-control study was conducted by enrolling 664 syphilis inpatients (excluding 11 congenital syphilis patients) and 800 sex- and age-matched controls. Medical histories, clinical data and patient interview data were collected and subjected to logistic regression analyses. The prevalence of syphilis in the study population was 3·9% (675/17 304). By univariate analysis, syphilis infection was associated with migration between cities, marital status, smoking, reproductive history, hypertension, elevated blood urea nitrogen (BUN) and infection with hepatitis B virus (HBV) (P < 0·05). A high rate of syphilis-HBV co-infection was observed in HIV-negative patients and further research revealed an association between syphilis and specific HBV serological reactivity. Syphilis was also associated with the frequency, duration and status of tobacco use. Multivariate analysis indicated that syphilis infection was independently associated with migration between cities [adjusted odds ratio (aOR) 1·368, 95% confidence interval (CI) 1·048–1·785], current smoking (aOR 1·607, 95% CI 1·177–2·195), elevated BUN (aOR 1·782, 95% CI 1·188–2·673) and some serological patterns of HBV infection. To prevent the spread of infectious diseases, inpatients and blood donors should be tested for HIV, syphilis, HBV and HCV simultaneously.

Hand, foot and mouth disease (HFMD) is an acute contagious condition caused by a spectrum of human enteroviruses. HFMD reinfection is common in the absence of cross-protection from other virus subtypes. This study focused on reinfection in children in Anhui province, China between 2008 and 2013 using surveillance system data. We classified 8960 cases as reinfected, corresponding to a rate of 2·02%. The reinfection rate was higher in boys than in girls [odds ratio (OR) 1·27, 95% confidence interval (CI) 1·21–1·32, P < 0·001], children aged < 3 years (OR 3·82, 95% CI 3·58–4·07, P < 0·001), and children living in rural areas (OR 1·09, 95% CI 1·04–1·14, P = 0·001). The reinfection rate in children who were originally infected with non-enterovirus A71 (non-EVA71) enteroviruses was higher than those infected with EVA71 (OR 1·36, 95% CI 1·02–1·80, P = 0·034). Influential factors of reinfection rate included annual incidence (β coefficient = 0·715, P = 0·002) and the proportion of EVA71 in patients with mild HFMD (β coefficient = −0·509, P = 0·018). These results demonstrate that boys aged <3 years, especially those in rural areas or regions with a lower EVA71 proportion are more prone to reinfection, and specific health education programmes should be developed to protect these susceptible populations.

Ag–reduced graphene oxide (Ag/rGO) nanoparticle composites were synthesized through a facile one-step hydrothermal reaction using GO and silver carbonate (Ag2CO3) as raw materials. The homogeneous silver nanospheres with an average size of 50 nm well dispersed on the surface of rGO were obtained without other additives. During the formation process, GO both promotes the dispersion of Ag2CO3 in aqueous solution and acts as the substrate of silver cations, and the hydrolysis of Ag2CO3 provides silver cations and alkaline condition. Moreover, GO further serves as reducing agent to generate elemental silver in the alkaline condition. The as-prepared materials exhibit excellent surface-enhanced Raman scattering activities when used to detect the Raman signals of R6G absorbed on the Ag/rGO substrate.

High-redshift quasars are unique probes of the evolution of supermassive black holes and the intergalactic medium at the end of the epoch of reionization. We present the optical spectra of eight new z ~ 6 quasars selected from the Panoramic Survey Telescope & Rapid Response System 1 (Pan-STARRS1). Details of the selection strategy can be found in Bañados et al. (2014). With this work we increase the number of known quasars at z < 5.7 by more than 10%. The quasars discovered here span a large range of luminosities (19.6 ≤ zP1 ≤ 21.2) and are remarkably heterogeneous in their spectral features: half of them show bright emission lines whereas the other half show weak or no Lyα emission line. We find a larger fraction of weak–line emission quasars than in lower redshift studies, although still based on low number statistics, this may imply that the quasar population could be more diverse than previously thought.

In this paper, the modified collocation Trefftz method (MCTM) and the exponentially convergent scalar homotopy algorithm (ECSHA) are adopted to analyze the inverse boundary determination problem governed by the biharmonic equation. The position for part of the boundary with given boundary condition is unknown and the position for the rest of the boundary with overspecified Cauchy boundary conditions is given a priori. Since the spatial position for portion of boundary is not given a priori, it is extremely difficult to solve such a boundary determination problem by any numerical scheme. In order to stably solve the boundary determination problem, the MCTM will be adopted in this study owing to that it can avoid the generation of mesh grid and numerical integration. When this problem is modeled by MCTM, a system of nonlinear algebraic equations will be formed and then be solved by ECSHA. Some numerical examples will be provided to demonstrate the ability and accuracy of the proposed scheme. In addition, the stability of the proposed meshless method will be tested by adding some noise into the prescribed boundary conditions and then to see how does that affect the numerical results.

In this paper, we estimated the black hole mass for some blazars with available variability time scales by assuming that the γ-ray emissions are from a distance of 200Rg from the center. The results show that the central black hole masses are in the range of log (M/M⊙) = 6.45 to 8.30.

In this paper, we compiled the X-ray observations for 138 Fermi blazars and calculated their Doppler factors, δγ. The calculated Doppler factors, δγ, are found strongly correlated with the γ-ray luminosity.

In this work, we investigate the emission of the nano-hole array in an ultrathin silver film at infrared regime. It is shown that when the incident light illuminates the nano-hole array, the localized surface plasmons are excited and serve as electric dipoles. The emission of the nano-hole array presents a strong directivity. The maximum radiation is located at infrared regime, and it can be tuned by the period of the nano-hole array, the incidence angle and the polarization of the excitation light. These findings extend our understandings of optical property of metallic nano-structures and provide a unique way to achieve infrared antenna arrays, which may achieve potential applications in photovoltaics and telecommunication.

Perovskites BaTi1 - z Mz O3 + δ (M = Fe, Cr, Mn, Co) has been sol-gel synthesized. Their transformation point of ferroelectric to paraelectric and the latent heat of the transformation were found a little lower than those for pure BaTiO3 (BTO), respectively. Layered composites Tb1 - x Dyx Fe2 - y –BaTi1 - z Mz O3 + δ have been fabricated. Their magnetoelectric (ME) effect has been investigated. All the bilayers containing the doped BTO displayed a stronger ME effects than that containing pure BTO does. The bilayer Tb1 - x Dyx Fe2 - y –BaTi0.99Cr0.01O3+δ was observed to show a larger ME coupling in the composites containing other doped BTO. While Tb1 - x Dyx Fe2 - y –BaTi0.985Fe0.015O3 + δ showed the largest ME effects in the bilayers Tb1 - x Dyx Fe2 - y –BaTi1 - z Fez O3 + δ (0 ≤z ≤ 0.02). Additionally, the ME voltage coefficient for the trilayers Tb1 - x Dyx Fe2 - y –BaTi0.99M0.01O3 + δ –Tb1 - x Dyx Fe2 - y was observed to be two or three times larger than that observed in the bilayers composed by the same substances. Theoretical analyses have been given for these observations. All the results suggest that the doped BTO can be a new choice of piezoelectrics in fabricating layered ME composites.

Five hundred strains of methicillin-resistant Staphylococcus aureus were tested against various anti-staphylococcal agents. Vancomycin, fusidic acid and fosfomycin were found to be the most effective. Only 1 strain out of 500 was resistant to fosfomycin. Three patients with methicillin-resistant Staphylococcus aureus septicaemia were successfully treated by fosfomycin. We conclude that fosfomycin could be the drug of choice for methicillin-resistant Staphylococcus aureus infection.