A plausible mode of action of pseudin-2, an antimicrobial peptide from Pseudis paradoxa

AbstractThe search for new antibiotic agents is continuous, reflecting the continuous emergence of antibiotic-resistant pathogens. Among the new agents are the antimicrobial peptides (AMPs), which have the potential to become a leading alternative to conventional antibiotics. Studies for the mechanisms of action of the naturally occurring parent peptides can provide the structural and functional information needed for the development of effective new antibiotic agents. We therefore characterized pseudin-2, an AMP isolated from the skin of the South American paradoxical frog Pseudis paradoxa. We found that pseudin-2 organized to an aggregated state in aqueous solution, but that it dissociated into monomers upon binding to lipopolysaccharide (LPS), even though it did not neutralize LPS in Gram-negative bacteria. In addition, pseudin-2 assumed an α-helical structure in the presence of biological membranes and formed pores in both bacterial and fungal membranes, through which it entered the cytoplasm and tightly bound to RNA. Thus, the potent antimicrobial activity of pseudin-2 likely results from both the formation of pores capable of collapsing the membrane potential and releasing intracellular materials and its inhibition of macromolecule synthesis through its binding to RNA

DataSheet_1_Microplastic contamination and microbial colonization in coastal area of Busan City, Korea.docx

This study investigated the potential role of the concentration, shape, size, and polymer type of microplastics (MP), in addition to the microbial community in six coastal areas of Busan city, South Korea. The results showed that the average MP concentration was 94 ± 41 particles·m-3, and particles sized 20 μm –300 μm accounted for 67.5 ± 9.6% of the total MP abundance throughout the study sites. Further, polyethylene (PE), polypropylene (PP), and polystyrene (PS) polymers were abundant among the collected fragment- and fiber-shaped MPs, implying that highly populated and industrialized areas are major sources of MPs contamination. Moreover, the bacterial diversity and taxa-based on 16S rRNA gene sequencing was significantly different between MPs and seawater (SW) samples. Specifically, Psychrobacter, Pseudomonas, Flavobacterium, and Winogradskyella were significantly enriched in MPs compared with SW (p <0.05). Redundancy analysis revealed that nutrient concentrations, salinity, and temperature potentially contributed to shaping the microbial communities on MPs. These results indicate the dynamic and complicated interactions of MP contamination with the physiochemical and environmental factors of the surrounding area. Our findings would help in understanding of MP contamination levels in marine environments and their characteristics, as well as bacterial colonization on plastics in urban coastal areas of Busan, South Korea.</p

Investigation of Surface Bacterial Diversities and Compositions in the Global Subway Facilities

Indoor microbes are a key component of air contamination that causes human health risks. However, compared with the aquatic and soil environment, microbial diversity and taxonomic structure and composition in subway facility are not well characterized. This study tries to explore surface bacterial communities by using swabs collected from four global subway facilities, such as Busan, Boston, Mexico City, and Moscow using 16S rRNA gene amplicon sequencing. The alpha-diversities on bacterial communities were significantly different between Moscow and other samples, despite the different sample characteristics among Busan, Boston, Mexico City samples. For bacterial taxonomic composition, three phyla such as Actinobacteria (41.1%), Proteobacteria (27.7%), and Firmicutes (18.9%), were most dominant among all samples, indicating that there was no significance (p > 0.05). The subway station surface samples were mostly dominated by Gram-positive bacteria, including genera Corynebacterium, Staphylococcus, and Streptococcus. PCoA analysis also revealed that the Moscow bacterial communities were clearly separated from others. In addition, core genera were only shared 75 genera among all samples, but 486 genera were shared with three global stations, such as Busan, Boston and Mexico City. These results suggested that the human activity and geographical environment potentially affect the establishment of the bacterial community. Although this study provided basic information on surface bacterial communities in the subway system, there is a remaining unknown microbiome in the indoor air environment. Therefore, we consistently try to understand the indoor environment’s microbial ecology in the subway system

15 Focal Planes Head-Mounted Display using LED Array Backlight

Currently, commercial head-mounted displays suffer from limited accommodative states, which lead to vergence-accommodation conflict. In this work, we newly design the architecture of head-mounted display supporting 15 focal planes over wide depth of field (20cm-optical infinity) in real time to alleviate vergence-accommodation confict. Our system employs a low-resolution vertical scanning backlight, a display panel (e.g. liquid crystal panel), and focus-tunable lens. We demonstrate the compact prototype and verify its performance through experimental results.N

Volumetric Head-Mounted Display With Locally Adaptive Focal Blocks

A commercial head-mounted display (HMD) for virtual reality (VR) presents three-dimensional imagery with a fixed focal distance. The VR HMD with a fixed focus can cause visual discomfort to an observer. In this article, we propose a novel design of a compact VR HMD supporting near-correct focus cues over a wide depth of field (from 18 cm to optical infinity). The proposed HMD consists of a low-resolution binary backlight, a liquid crystal display panel, and focus-tunable lenses. In the proposed system, the backlight locally illuminates the display panel that is floated by the focus-tunable lens at a specific distance. The illumination moment and the focus-tunable lens&apos; focal power are synchronized to generate focal blocks at the desired distances. The distance of each focal block is determined by depth information of three-dimensional imagery to provide near-correct focus cues. We evaluate the focus cue fidelity of the proposed system considering the fill factor and resolution of the backlight. Finally, we verify the display performance with experimental results.N

Cases for the sole effect of the Indian Ocean Dipole in the rapid phase transition of the El Nino-Southern Oscillation

The role of the Indian Ocean sea surface temperature (SST) in the rapid phase transition of the El Nino-Southern Oscillation (ENSO) has received much attention over the last few decades. However, the distinctive role of the Indian Ocean Dipole (IOD) and its underlying dynamics in controlling the rapid transition remains debatable, since it is difficult to isolate the sole effect of the IOD using observation. By conducting model experiments, this study demonstrated that the positive IOD cases could contribute to the rapid phase transition from El Nino to La Nina without the assistance of the Indian Ocean Basin-wide Mode. The westerly wind anomalies over the tropical western Pacific induced not only the El Nino phase via descending Kelvin waves in the equatorial eastern Pacific but also the SST cooling in the off-equatorial western Pacific via ascending Rossby waves. The positive feedback between the upwelling Rossby waves and cool SST maintained the Philippine Sea anticyclone anomalies. The accompanying easterly wind anomalies over the tropical western Pacific triggered upwelling oceanic Kelvin waves, leading to the occurrence of La Nina. This study shows the possible role of the IOD in the rapid phase transition of ENSO.11Nsciescopu

Ruthenium(ii)-catalyzed regioselective direct C4-and C5-diamidation of indoles and mechanistic studies

A ruthenium(ii)-catalyzed regioselective direct diamidation of 3-carbonylindoles at the C4- and C5-positions using various dioxazolones is described. This novel protocol allows for the effective installation of two amide groups on the benzene ring in indole. A remarkably broad substrate scope, excellent functional group tolerance, and mild reaction conditions are notable features of this protocol. Further explorations reveal that benzo[b]thiophene-3-carboxaldehyde is a viable substrate and affords its corresponding diamidation products. The diamido indoles are further converted into various functionalized products and used as sensors for metal ion detection. Density functional theory studies are also conducted to propose a reaction mechanism and provide a detailed understanding of the regioselectivity observed in the reaction.11Nsciescopu

Mediating and Moderating Factors of Adherence to Nutrition and Physical Activity Guidelines, Breastfeeding Experience, and Spousal Support on the Relationship between Stress and Quality of Life in Breast Cancer Survivors

Spousal support may attenuate stress in breast cancer survivors and improve their health-related quality of life (HRQoL). However, there is limited evidence of a relationship between spousal support, stress, and HRQoL in Asian populations. The current study examined whether spousal support, adherence to the American Cancer Society (ACS) Guidelines on Nutrition and Physical Activity for Cancer Survivors, and breastfeeding experience mediated or moderated the relationship between stress and HRQoL in Korean breast-cancer survivors. Between June 2016 and May 2018, 144 Korean women who survived breast cancer were recruited for the current cross-sectional study. Structured questionnaires and medical records were used to collect data. Structural equation modeling was used to examine mediating and moderating factors. Spousal support buffered the adverse effect of stress on HRQoL (&beta; = &minus;0.22 for stress&rarr;spousal support; &beta; = 0.27 for spousal support&rarr;physical HRQoL; &beta; = 0.40 for spousal support&rarr;mental HRQoL). We found that adherence to ACS guidelines moderated the association between stress and HRQoL (&beta; = &minus;0.14 for stress&rarr;mental HRQoL in high ACS adherence; &beta; = &minus;0.79 for stress&rarr;mental HRQoL in low ACS adherence). Moreover, beta coefficients were &minus;0.22 for stress&rarr;mental HRQoL in women with breastfeeding experience, and &minus;0.71 in those without breastfeeding experience. In conclusion, spousal support mediated the association between stress and HRQoL and this association was moderated by both adherence to ACS guidelines and breastfeeding experience