The reversible and cooperative activation process, which includes electron transfer from surrounding redox mediators, the reversible valence change of cofactors and macroscopic functional/structural ...change, is one of the most important characteristics of biological enzymes, and has frequently been used in the design of homogeneous catalysts. However, there are virtually no reports on industrially important heterogeneous catalysts with these enzyme-like characteristics. Here, we report on the design and synthesis of highly active TiO2 photocatalysts incorporating site-specific single copper atoms (Cu/TiO2) that exhibit a reversible and cooperative photoactivation process. Our atomic-level design and synthetic strategy provide a platform that facilitates valence control of co-catalyst copper atoms, reversible modulation of the macroscopic optoelectronic properties of TiO2 and enhancement of photocatalytic hydrogen generation activity, extending the boundaries of conventional heterogeneous catalysts.Reversible and cooperative activation processes are important characteristics of biological enzymes and can be used in designing catalysts. Highly active TiO2 photocatalysts incorporated with site-specific single copper atoms are now shown to exhibit such a photoactivation process.
Environmental air pollution encompasses various particulate matters (PMs). The increased ambient PM from industrialization and urbanization is highly associated with morbidity and mortality ...worldwide, presenting one of the most severe environmental pollution problems. This article focuses on the correlation between PM and skin diseases, along with related immunological mechanisms. Recent epidemiological studies on the cutaneous impacts of PM showed that PM affects the development and exacerbation of skin diseases. PM induces oxidative stress via production of reactive oxygen species and secretion of pro-inflammatory cytokines such as TNF-α, IL-1α, and IL-8. In addition, the increased production of ROS such as superoxide and hydroxyl radical by PM exposure increases MMPs including MMP-1, MMP-2, and MMP-9, resulting in the degradation of collagen. These processes lead to the increased inflammatory skin diseases and skin aging. In addition, environmental cigarette smoke, which is well known as an oxidizing agent, is closely related with androgenetic alopecia (AGA). Also, ultrafine particles (UFPs) including black carbon and polycyclic aromatic hydrocarbons (PAHs) enhance the incidence of skin cancer. Overall, increased PM levels are highly associated with the development of various skin diseases via the regulation of oxidative stress and inflammatory cytokines. Therefore, anti-oxidant and anti-inflammatory drugs may be useful for treating PM-induced skin diseases.
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Chronic hepatitis B virus (HBV) infection can cause cirrhosis and hepatocellular carcinoma and is therefore a serious public health problem. Infected patients are currently treated with ...nucleoside/nucleotide analogs and interferon α, but this approach is not curative. Here, we screen 978 FDA-approved compounds for their ability to inhibit HBV replication in HBV-expressing HepG2.2.15 cells. We find that ciclopirox, a synthetic antifungal agent, strongly inhibits HBV replication in cells and in mice by blocking HBV capsid assembly. The crystal structure of the HBV core protein and ciclopirox complex reveals a unique binding mode at dimer-dimer interfaces. Ciclopirox synergizes with nucleoside/nucleotide analogs to prevent HBV replication in cells and in a humanized liver mouse model. Therefore, orally-administered ciclopirox may provide a novel opportunity to combat chronic HBV infection by blocking HBV capsid assembly.
Post-translational modifications of one or more central "clock" proteins, most notably time-of-day-dependent changes in phosphorylation, are critical for setting the pace of circadian (≅24 h) clocks. ...In animals, PERIOD (PER) proteins are the key state variable regulating circadian clock speed and undergo daily changes in abundance and cytoplasmic-nuclear distribution that are partly driven by a complex phosphorylation program. Here, we identify O-GlcNAcylation (O-GlcNAc) as a critical post-translational modification in circadian regulation that also contributes to setting clock speed. Knockdown or overexpression of Drosophila O-GlcNAc transferase (ogt) in clock cells either shortens or lengthens circadian behavioral rhythms, respectively. The Drosophila PERIOD protein (dPER) is a direct target of OGT and undergoes daily changes in O-GlcNAcylation, a modification that is mainly observed during the first half of the night, when dPER is predominantly located in the cytoplasm. Intriguingly, the timing of when dPER translocates from the cytoplasm to the nucleus is advanced or delayed in flies, wherein ogt expression is reduced or increased, respectively. Our results suggest that O-GlcNAcylation of dPER contributes to setting the correct pace of the clock by delaying the timing of dPER nuclear entry. In addition, OGT stabilizes dPER, suggesting that O-GlcNAcylation has multiple roles in circadian timing systems.
Early synrift half‐grabens, herein named the Chilpo and Sinheung subbasins, have been newly recognised in the north‐central area of the Miocene Pohang Basin, Korea. The subbasins are closely aligned ...along an array of NNW‐trending strike‐slip faults and are bounded by ENE‐striking normal faults. The sediment infill of the subbasins consists of a deepening‐ and fining‐upward sequence of alluvial cobble to boulder conglomerate (FA1), alluvial to nearshore granule to pebble conglomerate and sandstone (FA2) and hemipelagic mudstone (FA3). The younger strata sequentially onlap the older strata in the hangingwall basement or transfer zones, whereas the footwall basement is directly onlapped by the younger hemipelagic mudstone. These patterns may have resulted from a series of domino‐style block rotations, in which subsidence along normal faults caused the differential creation of accommodation space, whilst simultaneous uplift in the upslope of rotated hangingwall blocks controlled denudation, the shedding of sediments to downslope areas and asymmetric stacking of sediments in both subbasins. In contrast to the western margin of the Pohang Basin, where large footwall‐derived fan‐delta systems developed along the bounding faults, in the Chilpo and Sinheung subbasins, small hangingwall‐derived alluvial‐fan deltas formed during rifting. The development of these domino‐style half‐grabens would have resulted from the detachment and simultaneous transrotation of the crustal block away from the northwest during accelerated extension in the Pohang Basin. Recent geophysical studies have detected very thin basin‐fill sediments in the north‐central Pohang Basin and faults that are similar in orientation to those identified in this study, thereby supporting our observations. These findings confirm the early opening of the Pohang Basin, supporting the hypothesis that all of the Miocene basins in southeastern Korea formed in a setting of NW–SE extension, and further suggest the development of the wedge‐shaped transtensional basin, in response to the opening of the East Sea (Sea of Japan) after 17 Ma.
Opening mode and morphology of the synrift half‐graben (Chilpo and Sinheung) subbasins and the possible movement of bounding faults during formation of the Miocene Pohang Basin. The opening of the subbasins was initiated along the NNW‐trending strike‐slip faults and extended by subvertical rotation of hangingwall blocks under the NW–SE extensional regime, suggesting a wedge‐shaped transtensional model for the Pohang Basin.
•Customer mistreatment was negatively related to job performance.•Organization-based self-esteem mediated the relationship between customer mistreatment and job performance.•Locus of control ...moderated the relationship between customer mistreatment and organization-based self-esteem.
The service encounter is an important social context for hospitality service providers who strive to satisfy their need for job competence by delivering excellent customer service. Customer mistreatment may be perceived as a sign of work-related goal failure by hospitality service providers. Building on the literature of goal attainment and failure in the workplace, we propose that hospitality employees, who experience customer mistreatment, undergo diminished organization-based self-esteem (OBSE), decreasing service performance. Moreover, employees’ locus of control is proposed to interact with customer mistreatment and predict service performance through the mediation of OBSE. The results of a multi-wave and multi-source survey, administered to a sample of hotel frontline employees (N = 180) and their direct supervisors (N = 38), show that customer mistreatment has a negative influence on service performance through OBSE, but only among employees with an external locus of control.
Common method variance has received much attention in the behavioral sciences. Nonetheless, scant scholarly effort has been invested in handling common method variance in hospitality research. This ...study investigates the current status of controlling for common method variance in hospitality research and assists researchers in taking appropriate actions. Study 1 shows hospitality researchers’ endeavors to control for common method bias through a critical review of literature published in four leading hospitality journals in the ten years from 2006 to 2015: International Journal of Hospitality Management, Journal of Hospitality & Tourism Research, Cornell Hospitality Quarterly and International Journal of Contemporary Hospitality Management. In Study 2, empirical investigations examine the effectiveness of a procedural remedy (temporal separation) and a statistical control (an unmeasured method factor approach) with two independent samples. The results of Study 1 reveal that most survey-related publications in the four journals fail to address or acknowledge common method variance. Moreover, only a limited number of techniques is found to be used to control for method variance. The findings of Study 2 suggest that temporal separation with a time lag of one day leads to a weak control for method variance; however, the use of an unmeasured method factor significantly helps control for method variance in the model.
The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 μmol m-2 ...s-1 for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 μmol m-2 s-1) and was lowered with decreased light intensity (70-80 μmol m-2 s-1). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment.
Abstract
We study the source regions of six solar energetic particle (SEP) events accelerated near or behind the limbs of the Sun. We use AI-generated farside magnetograms at a near real-time basis ...developed by Jeong et al. and AI
HMI
-PFSS extrapolations up to 2.5
R
⊙
computed using the input of the synchronic data combining AI-generated farside and HMI magnetograms. By comparing the AI
HMI
, HMI, Global Oscillations Network Group (GONG) synoptic magnetograms, and Air force Data Assimilative Photospheric flux Transport synchronic magnetograms, as well as the PFSS extrapolations, we find interesting differences between them in view of SEP source regions and magnetic field configurations. First, the structures and sizes of the source active regions (ARs) are changed. The total unsigned magnetic field fluxes of the ARs are mostly stronger in the AI
HMI
than in the HMI and GONG magnetograms. Second, newly emerging ARs are observed in the SEP source regions in the AI
HMI
magnetograms for two events. Third, the alterations in the magnetic flux, the emergence, and the dissipation of ARs lead to modifications in the locations of the global polarity inversion lines (PILs). The EUV wave propagation is typically observed to be oriented nearly perpendicular with respect to the local PIL, suggesting that the AI
HMI
-PFSS extrapolations around the source region are more realistic. This study shows that the continuous farside evolution of AR magnetic fields, which is accomplished by our AI synchronic magnetograms, can lead to an improved understanding of SEP source ARs.
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