Model representation of secondary organic aerosol in CMAQv4.7

Numerous scientific upgrades to the representation of secondary organic aerosol (SOA) are incorporated into the Community Multiscale Air Quality (CMAQ) modeling system. Additions include several recently identified SOA precursors: benzene, isoprene, and sesquiterpenes; and pathways: in-cloud oxidation of glyoxal and methylglyoxal, particle-phase oligomerization, and acid enhancement of isoprene SOA. NO(x)-dependent aromatic SOA yields are also added along with new empirical measurements of the enthalpies of vaporization and organic mass-to-carbon ratios. For the first time, these SOA precursors, pathways and empirical parameters are included simultaneously in an air quality model for an annual simulation spanning the continental U.S. Comparisons of CMAQ-modeled secondary organic carbon (OC(sec)) with semiempirical estimates screened from 165 routine monitoring sites across the U.S. indicate the new SOA module substantially improves model performance. The most notable improvement occurs in the central and southeastern U.S. where the regionally averaged temporal correlations (r) between modeled and semiempirical OC(sec) increase from 0.5 to 0.8 and 0.3 to 0.8, respectively, when the new SOA module is employed. Wintertime OC(sec) results improve in all regions of the continental U.S. and the seasonal and regional patterns of biogenic SOA are better represented.     

Superradiant Emission from Coherent Excitons in van Der Waals Heterostructures

Recent advancements in isolation and stacking of layered van der Waals materials have created an unprecedented paradigm for demonstrating varieties of 2D quantum materials. Rationally designed van der Waals heterostructures composed of monolayer transition-metal dichalcogenides (TMDs) and few-layer hBN show several unique optoelectronic features driven by correlations. However, entangled superradiant excitonic species in such systems have not been observed before. In this report, it is demonstrated that strong suppression of phonon population at low temperature results in a formation of a coherent excitonic-dipoles ensemble in the heterostructure, and the collective oscillation of those dipoles stimulates a robust phase synchronized ultra-narrow band superradiant emission even at extremely low pumping intensity. Such emitters are in high demand for a multitude of applications, including fundamental research on many-body correlations and other state-of-the-art technologies. This timely demonstration paves the way for further exploration of ultralow-threshold quantum-emitting devices with unmatched design freedom and spectral tunability.     

Adapting technology: effect of high-involvement HRM and organisational trust

This study is designed to empirically test a model of high-involvement human resource management (HIHRM), organisational trust, and technology adaptation grounded on social exchange theory in the context of the private banking sector. The proposed model intends to add to the understanding of the effect of HIHRM on technology adaptation via the mediating influence of organisational trust. Frontline employees were surveyed using a self-administered questionnaire. Results from partial least square-structural equation modelling suggest that there is a significant influence of HIHRM on technology adaptation. Organisational trust further mediates the relationship. Thus, this paper finds an answer to the ‘black box’ of human resource management (HRM) practices, explaining how HIHRM influences employees’ attitudes towards technology adaptation. The study can help management have a better understanding of the importance of employee involvement-oriented HRM in introducing and implementing a new technology through the integration of trust processes in the organisation.     

Effect of alpha-tocopherol on lipid peroxidation and total antioxidant status in spontaneously hypertensive rats

The aim of this study was to determine the effects of alpha-tocopherol on lipid peroxidation and total antioxidant status of spontaneously hypertensive rats (SHR), comparing them with normal Wistar-Kyoto (WKY) rats. SHR were divided into three groups and treated with different doses of alpha-tocopherol (alpha1, 17 mg/kg diet; alpha2, 34 mg/kg diet; and alpha3, 170 mg/kg diet). Normal WKY and untreated SHR were used as normal (N) and hypertensive control (HC). Blood pressures were recorded every 10 days for 3 months. At the end of the trial, animals were killed and measurement of plasma total antioxidant status, plasma superoxide dismutase (SOD) activity, and lipid peroxide levels in plasma and blood vessels was carried out following well-established methods. From our study it was found that lipid peroxides in thoracic aorta (N, 0.47 +/- 0.17; H, 0.96 +/- 0.37; P < .0001) and plasma (N, 0.06 +/- 0.01; H, 0.13 +/- 0.01) were significantly higher in hypertensives than in normal rats. SOD activity was significantly lower in hypertensive than normal rats (N, 172.93 +/- 46.91; H, 110.08 +/- 14.38; P < .005). Total antioxidant status was significantly higher in normal than hypertensive rats (N, 0.88 +/- 0.05; H, 0.83 +/- 0.02; P < .05). After the antioxidant trial, it was found that in the treated groups rise of blood pressure was prevented significantly (P < .001) and lipid peroxides in blood vessels were significantly reduced more than in the controls (P < .001). For plasma lipid peroxide it was only significant for groups alpha2 (P < .001) and alpha3 (P < .05). Although all three treated groups showed improved total antioxidant status, only groups alpha2 (0.87 +/- 0.04, P < .005) and alpha3 (1.20 +/- 0.18, P < .001) were statistically significant. All the three groups showed significant increases in their SOD activity (P < .001). Correlation studies showed that total antioxidant status and SOD were significantly negatively correlated with blood pressure in normal rats (P = .007; P = .008). Lipid peroxides in both blood vessel and plasma showed a positive correlation. In the treated groups, lipid peroxides in blood vessels maintained a significant positive correlation with blood pressure in all groups (alpha1, P = .021; alpha2, P = .019; alpha3, P = .002), whereas for plasma lipid peroxides the correlation was in groups alpha1 (P = .005) and alpha2 (P = .009). For SOD activity, significant negative correlations were found with blood pressure in the alpha2 (P = .017) and alpha3 (P = .025) groups. Total antioxidant status maintained a significant negative correlation with blood pressure in all three groups (alpha1, P = .012; alpha2, P = .044; alpha3, P = .014). In conclusion it was found that supplement of alpha-tocopherol may prevent development of increased blood pressure, reduce lipid peroxides in plasma and blood vessels, and enhance the total antioxidant status, including SOD activity.     

Adsorption of proteins on electro-conductive polymer films

Shapable electro-conductive (SEC) polymer films (polyanion-doped polypyrrole films) show several interesting properties for bioelectrochemical applications. The SEC film can be used as an inert, stable and hydrophobic electrode in aqueous solution over a wide potential range. In this study, the physical and the potential-assisted adsorption of various proteins on the SEC film is described. Because of the hydrophobic surface characteristic proteins easily adsorb and retain on the film surface by strong hydrophobic interactions. The amount of the adsorbed protein varies from 2.2 to 4.8 μg cm⁻² depending on the protein when the film is incubated for 22 h in the protein solution. The adsorption is effectively accelerated and enhanced by applying a positive potential in the range from 0.4 V to 1.0 V (vs. Ag/AgCl). The potential-assisted adsorption process is completed by 10–15 min and the amount of the adsorbed protein is nearly doubled as compared to the adsorption without potential. The adsorbed protein is chemically very stable in comparison with the protein in solution. More than 85% of the initial adsorbed proteins retains on the surface after three weeks of incubation in buffer solution. The initial adsorption rate is studied by quartz crystal micro-balance measurements on a thin polymer film coated quartz crystal. In addition, the SEC film surface is etched with air plasma which leads to a four-fold increase of the adsorption of proteins.