The anticipation for substituting conventional fossil fuels with cellulosic biofuels is growing in the face of increasing demand for energy and rising concerns of greenhouse gas emissions. However, ...commercial production of cellulosic biofuel has been hampered by inefficient fermentation of xylose and the toxicity of acetic acid, which constitute substantial portions of cellulosic biomass. Here we use a redox balancing strategy to enable efficient xylose fermentation and simultaneous in situ detoxification of cellulosic feedstocks. By combining a nicotinamide adenine dinucleotide (NADH)-consuming acetate consumption pathway and an NADH-producing xylose utilization pathway, engineered yeast converts cellulosic sugars and toxic levels of acetate together into ethanol under anaerobic conditions. The results demonstrate a breakthrough in making efficient use of carbon compounds in cellulosic biomass and present an innovative strategy for metabolic engineering whereby an undesirable redox state can be exploited to drive desirable metabolic reactions, even improving productivity and yield.
Nitrogen-doped carbon microspheres (NCSs) were fabricated via a simple, fast and energy-saving microwave-assisted method followed by thermal treatment under an ammonia atmosphere. NCSs thermally ...treated at different temperatures were investigated as anode materials for lithium ion batteries (LIBs). The results show that NCSs treated at 900 °C exhibit a maximum reversible capacity of 816 mA h g(-1) at a current density of 50 mA g(-1) and preserve a capacity of 660 mA h g(-1) after 50 cycles, and even at a high current density of 1000 mA g(-1), a capacity of 255 mA h g(-1) is maintained. The excellent electrochemical performance of NCSs is due to their porous structure and nitrogen-doping. The present NCSs should be promising low-cost anode materials with a high capacity and good cycle stability for LIBs.
Biochar amendments have been used in agriculture to improve soil fertility and enhance crop productivity. A greenhouse experiment was conducted to test the hypothesis that biochar amendment could ...also enhance the productivity of salt-affected soils. The trial was conducted over two consecutive growing seasons to investigate the effect of biochar amendment (four application rates as: B
= 0%, B
= 2%, B
= 4%, and B
= 8% by mass of soil) on yield and quality of tomatoes grown in a silt loam soil using non-saline water (I
= 0.7 dS m
) and saline water (I
= 1 dS m
; I
= 3 dS m
) irrigation. Furthermore, the study investigated the mechanism by which biochar addresses the salt stress on plant. The results showed that soil productivity as indicated by the vegetative growth and tomato yield components was adversely and significantly affected by saline water irrigation (P < 0.05). Tomato yield decreased from 689 ± 35.6 to 533 ± 79.0 g per plant as salinity of irrigation water increased from I
to I
. Then, biochar amendment increased vegetative growth, yield, and quality parameters under saline irrigation water regimes, and ameliorated the salt stresses on crop growth. The highest (8.73 ± 0.15 and 4.10 ± 0.82 g kg
) and the lowest (8.33 ± 0.08 and 2.42 ± 0.76 g kg
) values of soil pH and soil organic matter were measured at B
I
and B
I
treatments, respectively. Also, the highest rate of biochar amendment combining with non-saline water irrigation (B
I
) produced tomato with the highest plant photosynthetic (17.08 ± 0.19 μmol m
s
) and transpiration rate (8.16 ± 0.18 mmol H
O m
s
). Mechanically, biochar amendment reduced transient sodium ions by adsorption and released mineral nutrients such as potassium, calcium, and magnesium into the soil solution. Therefore, biochar amendments have the potential in ameliorating salt stress and enhancing tomato production.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Summary
What is known and objective
Vancomycin is one of the most widely used antibiotics for treating serious Gram‐positive infections in children. Few clinical studies have examined the potential ...risk factors for treatment failure in children receiving vancomycin. The objectives of this study were to evaluate the relationships between vancomycin trough concentration and treatment outcomes in Chinese paediatric patients with suspected Gram‐positive infections and to identify baseline characteristics that may affect treatment failure associated with vancomycin use.
Methods
A retrospective cohort study was conducted from April 2007 to October 2015. Patients were included in this study if they were <18 years old, had received vancomycin for at least 72 h and had at least one bacterial culture and one serum steady‐state vancomycin trough concentration. Treatment outcomes were defined as success or failure. Nephrotoxicity was defined as a serum creatinine (Scr) increase ≥44·2 μmol/L or a ≥50% increase in baseline Scr for at least two consecutive days. Univariate and multivariate logistic regression analyses were performed to identify risk factors for treatment failure with vancomycin.
Results and discussion
One hundred and eighty‐two patients were included. Vancomycin treatment failure occurred in 52 patients (28·6%), and the incidence of nephrotoxicity was low. No significant difference was observed in the vancomycin trough concentrations between the treatment success and failure groups. Multivariate logistic regression analyses showed that the vancomycin trough concentration odds ratio (OR), 1·046; 95% confidence interval (CI), 0·979–1·118; P = 0·179, statistical power: 62·04%) was not associated with treatment outcome, and only intensive care unit (ICU) admission (OR, 3·808; 95% CI, 1·714–8·465; P = 0·001, statistical power: 90·40%) was found to be independently associated with vancomycin treatment failure.
What is new and conclusion
Our findings suggest that the vancomycin trough concentration is not associated with treatment outcome. ICU admission is an independent predictor of treatment failure.
Our findings suggest that the vancomycin trough concentration is not associated with treatment outcome. Intensive care unit (ICU) admission is an independent predictor of treatment failure.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VSZLJ
We investigated phase constitutions, ferroelectric, magnetic, and nanomechanical characteristics of BiFeO3 films with Dy substitution. Bi1−xDyxFeO3 (x = 0.00–0.15) thin film were prepared on the Pt ...buffered glass substrates by pulsed laser deposition. BDFO films with x = 0.00–0.15 were confirmed to mainly consist of the perovskite phase. The structure is transformed from rhombohedral for x = 0.00 to pseudo-cubic for x = 0.05, and an additional phase, orthorhombic, is coexisted for x = 0.10 and 0.15. The studied BDFO polycrystalline films exhibit the desired ferroelectric and ferromagnetic properties at the same time. The remanent polarization (2Pr) of 165.7 μC/cm2 and electrical coercive field (Ec) of 337.5 kV/cm are obtained for BDFO films at x = 0.05. Leakage mechanisms in BDFO films with various contents x are also discussed. Besides, the saturation magnetization (Ms) of 2.1–26.8 emu/cm3 and coercivity (Hc) of 133–522 Oe are found. The increased Ms with Dy content x is related to the magnetic moment of the doped Dy3+ ion in addition to the suppressed spiral spin configuration. Furthermore, the hardness of 5.3–8.0 GPa for the BDFO films is found. The relationship between the hardness and grain size well agrees with the impeded propagation of dislocation by grain boundary mainly dominates the hardness. The result of this work indicates that the radius and magnetic moment of the Dy3+ ions plays a critical role in the structural evolution, refined microstructure, and therefore enhanced multiferroic and nanomechanical properties for Dy substituted BiFeO3 polycrystalline films.
•Simultaneous improvement in ferroelectric and ferromagnetic properties is found in Bi1−xDyxFeO3 films.•Good (110) texture, promoted crystallinity, and modified microstructure make BDFO have high ferroelectric properties.•Leakage mechanisms in BDFO films with x are also discussed.•The enhanced magnetic properties relates to the suppression of the spiral spin configuration and large magnetic moment of Dy3+ ion.•BDFO polycrystalline film is a high potential multiferroic material for advanced applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Wide Field-of-View Cherenkov Telescope Array (WFCTA) and the Water Cherenkov Detector Array (WCDA) of LHAASO are designed to work in combination for measuring the energy spectra of the cosmic ray ...species over a very wide energy range from a few TeV to 10 PeV. The energy calibration can be achieved with a proven technique of measuring the westward shift of the Moon shadow cast by galactic cosmic rays due to the geomagnetic field. This deflection angle Δ is inversely proportional to the cosmic ray rigidity. The precise measurement of the shifts by WCDA allows us to calibrate its energy scale for energies as high as 35 TeV. Through a set of commonly triggered events, the energy scales can be propagated to WFCTA. The energies of the events can be derived both by WCDA-1 and WFCTA with the median energies 23.4 ± 0.1 ± 1.3 TeV and ( 21.9 ± 0.1 TeV ), respectively, which are consistent within uncertainties. In addition, the propagation of the energy scale is also validated by the Moon shadow based on the same data selection criteria of the commonly triggered events. This paper reports, for the first time, an observational measurement of the absolute energy scale of the primary cosmic rays generating showers observed by air Cherenkov telescopes.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
An experimental investigation into noise reduction of supersonic jets through nozzle trailing-edge modifications was conducted, whereby far-field acoustic measurements were captured for two different ...stepped nozzles under two distinct under-expanded conditions. When compared to a baseline nozzle, results show that stepped nozzles lead to significant noise reductions at certain polar and azimuthal angles. In particular, a maximum noise reduction of 6 dB is observed for the longest stepped nozzle at a nozzle-pressure-ratio of 4 and 0° azimuthal angle. Spectral analysis shows that the noise reduction is mainly due to reduction in broadband shock associated noise and elimination of jet screech phenomenon. Abrupt changes in nozzle lip lengths of the stepped nozzles appear to disrupt acoustic feedback loop, thus resulting in screech cessation. Qualitative schlieren imaging and quantitative schlieren measurements were subsequently performed to correlate the shock structures and density gradient fields with the resulting noise components. Unlike those produced by the baseline nozzle, shock structures generated by the stepped nozzles are highly irregular and the jet plumes undergo discernible deflections. Lastly, the reduction in broadband shock associated noise is related to the lower shock strengths, as demonstrated by the density gradient profiles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Additive manufacturing (AM) of metallic materials and welding share many similarities in their physical processes and the way the microstructure and properties of the products evolve. This synergy ...can be a powerful driver for the scientific and technological advancements of both these important technologies for the benefit of all people. Science and Technology of Welding and Joining provides a forum for the exchange of emerging scientific and technological advancements in AM. This special issue of the journal highlights the current research in the AM processes, and the microstructure and properties of metallic components. Furthermore, it identifies some of the current challenges and opportunities for the future.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•Effects of temperature and voltage on the morphology of carbon product were evaluated.•Carbon products exhibited different forms (particles, sheets and nanostructured cages).•Carbon powders with ...surface area of 868.3m2g−1 can be prepared.•Optimized energy consumption for preparing the carbon products was 35.6kWhkg−1.
With a SnO2 inert anode, amorphous carbon powders were successfully deposited on a nickel cathode by electrochemical conversion of CO2 in Li2CO3–Na2CO3–K2CO3 eutectic melt in the temperature range of 450°C to 650°C and under the electrolysis voltages of 3.0V to 6.0V. The effects of electrolysis temperature and cell voltage on the morphology and structure of the produced carbon, and on the energy consumption of the process were systematically investigated. The morphologies and particle size of the carbon products were proven to be affected by the electrolysis cell voltage and temperature. As the electrolysis condition varied, the deposited carbon exhibited different forms, including nanoparticle, nanoflake, nanosheet and heart-shape nanostructured cage, etc. The particle sizes of the obtained carbon ranged from av. 2μm to 50nm, and smaller particles were obtained at higher cell voltage and lower electrolysis temperature. The carbon product obtained at 450°C under 5.5V exhibited the highest BET surface area of 868.3m2g−1. FTIR analysis demonstrated that oxygen-containing functional groups presented on the surface of the carbon product, which was most likely due to the active dangling bond on the carbon materials. The optimized energy consumption for producing 1 kg of carbon is as low as 35.59kWh with a current efficiency of 87.86% at 450°C under a constant cell voltage of 3.5V.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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