Effects of selenium adaptation on intestinal morphology, antioxidant-relate genes expression and intestinal microflora of grass carp (Ctenopharyngodon idella)

In the study, the effects of selenium on intestinal tissue morphology, antioxidant-related genes, and intestinal flora of grass carp (Ctenopharyngodon idella) were studied. For this purpose, 180 healthy grass carps (20.0±2.0 g) were randomly divided into three groups with three replicates each: the corresponding amount of anhydrous sodium selenite was added to make experimental water solutions of different concentrations, including 0 μg/L Se4+ (control group), 200 μg/L Se4+ group and 300 μg/L Se4+ group. The experiment was carried out for 42 days. The obtained results showed that: at the end of the experiment, the 200 μg/L Se4+ adaptation can have beneficial effects on the intestinal villi height and goblet cells. The CuZnSOD and CAT genes mRNA levels of grass carp intestine were strongly upregulated in the 200ug/L Se4+ group. 200ug/L selenium could increase the expression level of the Hsp70 gene in the intestinal tract of grass carp after 42 days of adaptation. At the genus level, the most abundant sequence in the gut of Se-treated grass carp was Pseudomonas, while Aeromon, Flavobacterium, and Defluviimonas were more abundant in the control group. In conclusion, this study demonstrates that 200ug/L Se4+ selenium adaptation can positively affect gut morphology and antioxidant responses and can alter the gut microbiota structure of grass carp. The results will provide a theoretical basis for further research on the effect of selenium on aquatic animals

Unveiling microstructural damage for leakage current degradation in SiC Schottky diode after heavy ions irradiation under 200 V

Single-event burnout and single-event leakage current (SELC) in SiC power devices induced by heavy ions severely limit their space application, and the underlying mechanism is still unclear. One fundamental problem is lack of high-resolution characterization of radiation damage in the irradiated SiC power devices, which is a crucial indicator of the related mechanism. In this letter, high-resolution transmission electron microscopy (TEM) was used to characterize the radiation damage in the 1437.6 MeV 181Ta-irradiated SiC junction barrier Schottky diode under 200 V. The amorphous radiation damage with about 52 nm in diameter and 121 nm in length at the Schottky metal (Ti)-semiconductor (SiC) interface was observed. More importantly, in the damage site the atomic mixing of Ti, Si, and C was identified by electron energy loss spectroscopy and high-angle annular dark-field scanning TEM. It indicates that the melting of the Ti-SiC interface induced by localized Joule heating is responsible for the amorphization and the formation of titanium silicide, titanium carbide, or ternary phases. These modifications at nanoscale in turn cause the localized degradation of the Schottky contact into Ohmic contact, resulting in the permanent increase in leakage current. This experimental study provides some valuable clues to thorough understanding of the SELC mechanism in SiC diode.Comment: 4 pages,4 figure

Osmotic Stress Induced Cell Death in Wheat Is Alleviated by Tauroursodeoxycholic Acid and Involves Endoplasmic Reticulum Stress–Related Gene Expression

Although, tauroursodeoxycholic acid (TUDCA) has been widely studied in mammalian cells because of its role in inhibiting apoptosis, its effects on plants remain almost unknown, especially in the case of crops such as wheat. In this study, we conducted a series of experiments to explore the effects and mechanisms of action of TUDCA on wheat growth and cell death induced by osmotic stress. Our results show that TUDCA: (1) ameliorates the impact of osmotic stress on wheat height, fresh weight, and water content; (2) alleviates the decrease in chlorophyll content as well as membrane damage caused by osmotic stress; (3) decreases the accumulation of reactive oxygen species (ROS) by increasing the activity of antioxidant enzymes under osmotic stress; and (4) to some extent alleviates osmotic stress–induced cell death probably by regulating endoplasmic reticulum (ER) stress–related gene expression, for example expression of the basic leucine zipper genes bZIP60B and bZIP60D, the binding proteins BiP1 and BiP2, the protein disulfide isomerase PDIL8-1, and the glucose-regulated protein GRP94. We also propose a model that illustrates how TUDCA alleviates osmotic stress–related wheat cell death, which provides an important theoretical basis for improving plant stress adaptation and elucidates the mechanisms of ER stress–related plant osmotic stress resistance

Highly Ductile and Ultra-Thick P-Doped FeSiB Amorphous Alloys with Excellent Soft Magnetic Properties

Herein, we demonstrate the successful synthesis of novel Fe80Si9B(11−x)Px (x = 0, 1, 3, 5, 7) ultra-thick amorphous ribbons by planar flow casting. The influence of P alloying on glass forming ability (GFA), microstructure, thermal stability, soft magnetic properties, and ductility has been systematically investigated. The results reveal that introduction of P into Fe80Si9B11 alloy can remarkably enhance the GFA and increase critical thickness (tc) of the alloy from 45 to 89 um. Furthermore, the annealed FeSiBP amorphous alloys exhibited excellent soft magnetic properties, including high saturation magnetic flux density of 1.54 T, the low coercivity of 1.5 A/m, and low core losses of 0.15 W/kg. In addition, the representative Fe80Si9B8P3 ultra-thick amorphous alloy demonstrate excellent ductility even after annealing at 400 °C for 10 min, which indicates the superior performance of P-doped FeSiB alloys as compared to the commercial Fe78Si9B13 (Metglas 2605 S2) alloy. The combination of high GFA, excellent ductility, and low core losses of newly developed FeSiBP amorphous soft magnetic alloys makes them attractive candidates for magnetic applications in the high-frequency and high-speed electric devices

FPGA-based signal processing in an optical feedback self-mixing interferometry system

Optical feedback Self-mixing Interferometry (OFSMI) can achieve a high-resolution displacement sensing and measurement by using advanced digital signal processing. However, most existing signal processing algorithms used for OFSMI signals are implemented on a PC by Matlab or other programming languages. In this case, the whole structure of OFSMI sensing system is incompact and the measurement is in low speed. The design trends in sensing systems are towarding to small size, high integration and fast real time processing. These trends require us to improve the existing OFSMI design. It is a good solution to apply Field-programmable gate arrays (FPGAs) technique onto OFSMI sensing systems. In this work, we designed a FPGA based signal processing unit for an OFSMI displacement sensing system. The OFSMI sensing signals observed from an OFSMI system is connected to a FPGA development board (Spartan-3E) for high speed signal processing. The FPGA processing unit retrieves the displacement information carried in the OFSMI signals. The FPGA design includes noise reduction, signal peak detection and impulse magnitude tracking. As the magnitude of the sensing signal is time-varying, for adapting the variation, a dynamic updating algorithm is introduced in the magnitude tracking unit. Both simulation and hardware co-simulation show that the OFSMI system with a FPGA based signal processing unit can achieve fast and reliable displacement sensing

Analysis on the sources of value added of American crop exports and employment

This paper uses the WIOD database combined with the global value chain decomposition to measure the value added of the crop industry and other industries included in the US crop exports. Use the employment coefficient to further analyze the impact of US crop exports on the employment of its own industry and other industries and the impact of exports from other industries on employment in the crop industry. We found: (1) The value-added of the service industry included in the export of the US crop industry is higher than that of the manufacturing industry and the primary industry. (2) Among the exports of other industries, the crop industry included in the manufacturing export has the most value-added and continues to increase, while the value added of the service industry and the primary industry is low. (3) The number of employed people in the industry driven by the export of the US crop industry is increasing. Among the other industries, the service industry has the largest number of employed people driven by the export of the crop industry

Analysis of Vibration Responses Induced by Metro Operations Using a Probabilistic Method

The environmental vibrations of tunnels and soil caused by metro operations is one of the most important issues in the field of environmental geotechnical engineering. Recent studies in metro-induced vibrations have revealed significant uncertainties in the vibration responses of tunnels and the surrounding soil. A two-step method of obtaining train loads considering uncertainty was introduced. The first step was to obtain the train loads via an inverse model based on measurements, and the second step was to quantify the uncertainty of train loads based on complex principal component analysis. A portion of a tunnel of the Beijing metro was selected as the object of study, where the vertical accelerations on the rail and on the tunnel wall were measured under different train speeds of 35, 45 and 55 km/h. Inputting the train loads based on the measured rail accelerations into an axisymmetric numerical model, established using ANSYS, the vibration responses of the tunnel wall in a probabilistic framework were calculated and were compared with the measured results. By using an accuracy index that considers both calculation bias and uncertainty, the accuracy of the calculated vibration response was quantitatively evaluated. It can be concluded that the calculated vibration response can reflect the actual vibration level and uncertainty of the tunnel wall. The accuracies of the calculated results under different speeds were generally high while showing a slight difference in amplitude

Effects of the Gas-Atomization Pressure and Annealing Temperature on the Microstructure and Performance of FeSiBCuNb Nanocrystalline Soft Magnetic Composites

FeSiBCuNb powders prepared by the gas atomization method generally exhibit a wide particle size distribution and a high degree of sphericity. In addition, the correspondingly prepared nanocrystalline soft magnetic composites (NSMCs) perform good service stability. In this paper, effects of the gas-atomization pressure and annealing temperature on the microstructure and soft magnetic properties of FeSiBCuNb powders and NSMCs are investigated. The results show that the powders obtained by a higher gas-atomization pressure possess a larger amorphous ratio and a smaller average crystallite size, which contribute to the better soft magnetic performance of the NSMCs. After being annealed at 550 °C for 60 min, the NSMCs show a much better performance than those treated by the stress-relief annealing process under 300 °C, which indicates that the optimization of the soft magnetic properties resulting from the precipitation of the α-Fe(Si) nanocrystalline largely overwhelms the deterioration caused by the grain growth of the pre-existing crystals. In addition, the annealed NSMCs prepared by the powders with the gas-atomization pressure of 4 MPa show the best performance in this work, μe = 33.32 (f = 100 kHz), Hc = 73.08 A/m and Pcv = 33.242 mW/cm3 (f = 100 kHz, Bm = 20 mT, sine wave)

Effects of the Gas-Atomization Pressure and Annealing Temperature on the Microstructure and Performance of FeSiBCuNb Nanocrystalline Soft Magnetic Composites

FeSiBCuNb powders prepared by the gas atomization method generally exhibit a wide particle size distribution and a high degree of sphericity. In addition, the correspondingly prepared nanocrystalline soft magnetic composites (NSMCs) perform good service stability. In this paper, effects of the gas-atomization pressure and annealing temperature on the microstructure and soft magnetic properties of FeSiBCuNb powders and NSMCs are investigated. The results show that the powders obtained by a higher gas-atomization pressure possess a larger amorphous ratio and a smaller average crystallite size, which contribute to the better soft magnetic performance of the NSMCs. After being annealed at 550 °C for 60 min, the NSMCs show a much better performance than those treated by the stress-relief annealing process under 300 °C, which indicates that the optimization of the soft magnetic properties resulting from the precipitation of the α-Fe(Si) nanocrystalline largely overwhelms the deterioration caused by the grain growth of the pre-existing crystals. In addition, the annealed NSMCs prepared by the powders with the gas-atomization pressure of 4 MPa show the best performance in this work, μe = 33.32 (f = 100 kHz), Hc = 73.08 A/m and Pcv = 33.242 mW/cm3 (f = 100 kHz, Bm = 20 mT, sine wave)