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A Fresnel zone plate based SPEM (scanning photoelectron microscope) is in operation at the Pohang Light Source. Space resolution of the SPEM is typically, $\lesssim $1 μm (0.4 μm in the best resolution) and the photon flux at the focused spot is ~109photons/s. The SPEM is working in the energy range between 400 and 1,000 eV. In taking images and spectra, the SPEM detects photoelectrons from the focused spot using a hemispherical analyzer with 16-channel detection capability at energy resolution of ~0.5 eV. The SPEM also measures sample current, with which comparative x-ray absorption micro-spectroscopy is available in limited energy range with spectral resolving power (E/ΔE) of ~3,000. The advantage of detecting sample current image and x-ray absorption spectrum at the Fe Llll,-edge is demonstrated for understanding the effect of electrochemically deposited Zn layer on Fe substrate.

Focused x-rays on insulating layers produce local charges and the local charges result in kinetic energy shift in photoelectron spectra. In our study, when the thickness of the insulating layers was in the range of micrometer, the amount of kinetic energy shift initially increased within seconds to a value depending on the thickness and chemical composition of the insulator. The amount of energy shift stayed at the same value as long as the insulator was resistant to radiation damage. When the insulator was susceptible to radiation damage, then the amount of energy shift decreased as a function of time. The main cause of this decrease is attributed to conductivity increase due to chemical state change at the x-ray exposed volume of the insulator. The implication of the results is that scanning photoelectron microscopy (SPEM) can be applied for investigation of microstructures containing insulating materials; for example, SPEM can be used for depth-probe conducting microstructures embedded in micrometer-thick insulating layers. This study was performed with a SPEM at the Pohang Light Source, with an x-ray intensity at the focused area of ~109photons/(s.μm2).

A simplified three‐dimensional Navier‐Stokes (3‐D NS) model for two fluids, water and landslide material (mudslide) is presented and validated with standard laboratory experiments. Dubbed TSUNAMI3D (Tsunami Solution Using Navier‐Stokes Algorithm with Multiple Interfaces) is applied to a 3‐D full‐scale landslide scenario in the Gulf of Mexico (GOM), i.e., the East‐Breaks underwater landslide. The simplified 3‐D NS model is conceived to be computationally efficient for tsunami calculations. The simplification is derived from the large aspect ratio of the tsunami waves (wavelength/wave‐height) and the selected computational grid that has a smaller aspect ratio. This allows us to assume a horizontal fluid surface in each individual cell containing the interface (air‐water, air‐mudslide, and water‐mudslide). The tracking of fluid interfaces is based on the Volume of Fluid method and the surfaces are obtained by integrating the fluxes of each individual fluid cell along the water column. In the momentum equation, the pressure term is split into two components, hydrostatic and nonhydrostatic. The internal friction is solved in a simplified manner by adjusting the viscosity coefficient. Despite the simplification to get an efficient solution, the numerical results agree fairly well with standard landslide laboratory experiments required by the National Tsunami Hazard Mitigation Program for tsunami model validation. The numerical effect caused by using a sharp versus a diffusive water‐mudslide interface for a full‐scale landslide‐tsunami scenario is also investigated. Observations from this experiment indicated that choosing a sharp or diffusive interface seems to have no remarkable effect at early stages of the tsunami wave propagation. Last, a large scale 3‐D numerical simulation is carried out for the ancient GOM's East‐Breaks landslide by using the simplified model to calculate the early stages of the tsunami wave propagation. To present the underlying physics of a 3‐D model for landslide tsunamiTo validated the model against laboratory experiments suggested by the NTHMPTo apply the 3‐D model to a submarine landslide scenario in the Gulf of Mexico

In this study, two lytic bacteriophages (LMP1 and LMP7) targeting L. monocytogeneswere isolated from the intestinal content of healthy chickens to identify those with the greatest potential in reducing L. monocytogenesin dairy foods. The host specificity of these bacteriophages was determined with different serotypes of L. monocytogenesstrains by the formation of lytic zones and plaques on host lawns. Genomic and morphological analyses of these phages were also performed to investigate their potential as a means of biocontrol of L. monocytogenesin the dairy industry. Lytic activity of Listeriabacteriophages was assessed in tryptic soy broth inoculated with L. monocytogenesATCC 7644 or ATCC 19114 and incubated at 30°C for 24 h. Phage lytic activity was also evaluated at 10°C for 5 d in the same composition. LMP1 and LMP7 were able to inhibit the growth of L. monocytogenesATCC 7644 and ATCC 19114 compared with the untreated control both at 30°C and 10°C. LMP1 was more effective than LMP7 against L. monocytogenesATCC 19114; contrary to this, LMP7 was more effective than LMP1 against L. monocytogenesATCC 7644. Morphological characterization from electron microscopy reveals that both LMP1 and LMP7 belong to the Siphoviridaefamily. Bacteriophage genome sequences were determined by next-generation sequencing, and they contain about 40 kb and 47 kb with 69 and 67 coding sequence genes, respectively. Comparative genome analyses could provide some evidence of their different host specificity. The effectiveness of phage cocktail (LMP1 and LMP7) on the growth of L. monocytogenesin milk samples was investigated at 30°C and 10°C. The growth of L. monocytogenesin milk was effectively inhibited by using the phage cocktail. In conclusion, two listeriaphages (LMP1 and LMP7) exhibiting different host specificity were isolated and further characterized; a phage cocktail with these phages could serve as a tool of biocontrol of L. monocytogenesin dairy foods.

The purpose of this study was to screen lactic acid bacteria (LAB) for anti-inflammatory activities using RAW 264.7 cells and a dextran sulfate sodium (DSS)-induced colitis animal model. Among 150 lactic acid bacteria strains isolated from healthy human feces, eight LAB strains showing excellent nitric oxide (NO) inhibitory activities were selected for further study. Peptidoglycan extracts of these strains were conducted in NO assay, western blot, and enzyme-linked immunosorbent assay (ELISA). Peptidoglycan extracts of four LAB strains significantly inhibited the production of NO related enzyme activities, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), and key cytokine levels, such as tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), in RAW 264.7 cells. These four isolates were identified as Lactobacillus plantarumbased on biochemical and molecular biological characterization. Additionally, the oral administration of the four LAB strains inhibited dextran sulfate sodium (DSS)-induced loss of body weight, colon shortening, and damage of colon tissue in ICR mice. Important protein level in their colon tissue, including iNOS, COX-2, TNF-α, and IL-6, were significantly reduced in the L. plantarumtreated group. Therefore, these isolates could be used as candidate probiotic strains for the prevention and treatment of inflammatory bowel disease (IBD). We need to further investigate the mechanisms of interaction between peptidoglycans of the L. plantarumstrain and the upstream cellular signaling mediators.

In this study, we investigated the effect of dietary supplementation of Cu-Met chelate (Cu-Met) and Cu-soy proteinate (Cu-SP) on the performance, blood parameters, liver mineral content, and intestinal microflora in broiler chickens. A total of 1,008 hatched Ross broiler chickens were randomly assigned to 1 of 6 dietary treatments (T): T1, control; T2, antibiotic (6 ppm of avilamycin); T3, 50 ppm of Cu as Cu-Met; T4, 100 ppm of Cu as Cu-Met; T5, 50 ppm of Cu as Cu-SP; and T6, 100 ppm of Cu as Cu-SP. Each treatment had 3 replicates of 56 birds (28 birds of each sex). During the 4-wk feeding period, the BW increase of birds in the antibiotic treatment was 3.25% and those of birds in the 100 ppm of Cu treatments were 2.67% on average compared with the control group. The production efficiency factor {[livability (%) × live weight (kg)/age (d) × FCR] × 100} was increased by 5.23% for birds in the antibiotic treatment and by 0.7 to 7.8% for birds in Cu treatments, among which the treatment with 100 ppm of Cu as Cu-SP was highest. The red blood cell level, hematocrit level, and mean corpuscular volume of birds in the Cu treatments were lower than were those of birds in the control group. Copper concentration in the liver increased as the level of Cu supplementation increased. The populations of lactobacilli and total bacteria increased, and that of Escherichia coli decreased as the level of Cu increased, whereas all microbes, including Clostridium perfringens, decreased in the antibiotic treatment.