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Geometric and electronic structures of silicene on Cu(111) covered with a monolayer of hexagonal boron nitride (h-BN) were investigated by ab initio density functional theory calculations. We found that a silicene with a regularly buckled configuration is stabilized on h-BN layer stacking commensurately to the Cu(111) substrate. The electronic band structure projected to Si 3pz orbital clearly shows a band crossing similar to a Dirac cone emerging in the band structure of freestanding buckled silicene. This is in contrast to the silicene on Cu(111), in which the Dirac fermion features disappear entirely due to the strong interactions at the interface. These examples demonstrate that the h-BN monolayer effectively prevents silicene from interacting with the underlying Cu(111) substrate and that the h-BN monolayer on Cu(111) is a promising candidate for use as a substrate on which to realize silicene hosting the Dirac fermion features. [ABSTRACT FROM AUTHOR]

The light output and reliability testing of the GaN-based blue light-emitting diode (LED) packaging have been carried out with TiO2 nanoparticles (NPs) doped into silicone encapsulation. The LED samples including pure silicone and silicone with various doping concentrations of TiO2 NPs were fabricated and analyzed. The average refractive index of silicone doped with TiO2 NPs with an average diameter of 21 nm was increased while the light extraction efficiency of GaN-based blue LEDs was also enhanced. Moreover, doping the silicone encapsulation with 0.0002 wt % TiO2 NPs could increase the light extraction efficiency by 4.1%. By analyzing the optical-thermal properties, reliability testing, and refractive index of silicone encapsulation, we also demonstrated that doping silicone encapsulation with TiO2 NPs not only enhanced the light extraction efficiency but also improved the reliability of LEDs compared with that of LEDs without TiO2 NP doping. It was considered that the increase in the average refractive index and light scattering reduced the internal reflection loss at the silicone encapsulation between air interfaces, thereby significantly reducing the heat accumulation in LED packaging. [ABSTRACT FROM AUTHOR]

We have investigated the atomic structure of the "multilayer silicene" grown on the Ag(111) single crystal surface by using low energy electron diffraction (LEED) and scanning tunneling microscopy (STM). We measured the intensity of the LEED spot as a function of the incident electron energy (I-V curve) and analyzed the I-V curve using a dynamical LEED theory. We have found that the Si(111)( 3× 3)-Ag model well reproduces the I-V curve whereas the models consisting of the honeycomb structure of Si do not. The bias dependence of the STM image of multilayer silicene agrees with that of the Si(111)( 3× 3)-Ag reconstructed surface. Consequently, we have concluded that the multilayer silicene grown on Ag(111) is identical to the Si(111)( 3× 3)-Ag reconstructed structure. Graphical abstractImage 1Highlights· We have determined the atomic structure of "multilayer silicene" on Ag(111) single crystal by using LEED. · The Si(111) 3× 3-Ag reconstructed model well reproduced the experimental data while honeycomb models did not. · The structure of "multilayer silicene" is identical with that of Si(111) 3× 3-Ag reconstraction. [ABSTRACT FROM AUTHOR]

Tubulointerstitial fibrosis is a major pathological hallmark of diabetic nephropathy. Increasing evidence has shown that epithelial-to-mesenchymal transition (EMT) of renal proximal tubular cells plays a crucial role in tubulointerstitial fibrosis. Herein, we aimed to elucidate the detailed mechanism of EMT in renal tubular cells under high glucose (HG) conditions, and to investigate the potential of licorice, a medicinal herb, to inhibit HG-induced EMT. Our results showed that renal tubular epithelial cells (normal rat kidney cell clone 52E; NRK-52E) exposed to HG resulted in EMT induction characterized by increased fibronectin and α-SMA (alpha-smooth muscle actin) but decreased E-cadherin. Elevated levels of cleaved Notch2, MAML-1 (mastermind-like transcriptional coactivator 1), nicastrin, Jagged-1 and Delta-like 1 were also concomitantly detected in HG-cultured cells. Importantly, pharmacological inhibition, small interfering RNA (siRNA)-mediated depletion or overexpression of the key components of Notch2 signaling in NRK-52E cells supported that the activated Notch2 pathway is essential for tubular EMT. Moreover, we found that licorice extract (LE) with or without glycyrrhizin, one of bioactive components in licorice, effectively blocked HG-triggered EMT in NRK-52E cells, mainly through suppressing the Notch2 pathway. Our findings therefore suggest that Notch2-mediated renal tubular EMT could be a therapeutic target in diabetic nephropathy, and both LE and de-glycyrrhizinated LE could have therapeutic potential to attenuate renal tubular EMT and fibrosis. [ABSTRACT FROM AUTHOR]

The orf47-orf46-orf45 gene cluster of Kaposi's sarcoma-associated herpesvirus (KSHV) is known to serially encode glycoprotein L (gL), uracil DNA glycosylase, and a viral tegument protein. Here, we identify two novel mRNA variants, orf47/45-A and orf47/ 45-B, alternatively spliced from a tricistronic orf47-orf46-orf45 mRNA that is expressed in the orf47-orf46-orf45 gene locus during the early stages of viral reactivation. The spliced gene products, ORF47/45-A and ORF47/45-B, consist of only a partial region of gL (ORF47), a unique 7-amino-acid motif, and the complete tegument protein ORF45. Like the ORF45 protein, ORF47/45-A and ORF47/45-B expressed in cells sufficiently activate the phosphorylation of p90 ribosomal S6 kinase (RSK) and extracellular signal-regulated protein kinase (ERK). However, unlike ORF45, both ORF47/45-A and ORF47/45-B contain a signal peptide sequence and are localized at the endoplasmic reticulum (ER). Additionally, we found that ORF47/45-A and ORF47/45-B have an extra function that mediates the upregulation of GRP78, a master regulator of ER homeostasis. The important event regarding GRP78 upregulation can be observed in all tested KSHV-positive cell lines after viral reactivation, and knockdown of GRP78 in cells significantly impairs viral lytic cycle progression, especially at late lytic stages. Compared with some other viral glycoproteins synthesized through the ER, our results strongly implicate that the ORF47/45 proteins may serve as key effectors for controlling GRP78 expression and ER homeostasis in cells. Taken together, our findings provide evidence showing the reciprocal association between the modulation of ER homeostasis and the progression of the KSHV lytic cycle. [ABSTRACT FROM AUTHOR]