Topological band-order transition and quantum spin Hall edge engineering in functionalized X-Bi(111) (X = Ga, In, and Tl) bilayer

Functionalized X-Bi bilayers (X = Ga, In, and Tl) with halogens bonded on their both sides have been recently claimed to be the giant topological insulators due to the strong band inversion strengths. Employing the first-principles electronic structure calculation, we find the topological band order transition from the order p-p-s of the X-Bi bilayers with halogens on their both sides to the new order p-s-p of the bilayers (especially for X = Ga and In) with halogen on one side and hydrogen on the other side, where the asymmetric hydrogen bonding simulates the substrate. We further find that the p-s bulk band gap of the bilayer bearing the new order p-s-p sensitively depends on the electric field, which enables a meaningful engineering of the quantum spin Hall edge state by controlling the external electric field. © 2016 The Author(s).1

Effect of interlayer interactions on exciton luminescence in atomic-layered MoS2 crystals

The atomic-layered semiconducting materials of transition metal dichalcogenides are considered effective light sources with both potential applications in thin and flexible optoelectronics and novel functionalities. In spite of the great interest in optoelectronic properties of two-dimensional transition metal dichalcogenides, the excitonic properties still need to be addressed, specifically in terms of the interlayer interactions. Here, we report the distinct behavior of the A and B excitons in the presence of interlayer interactions of layered MoS 2 crystals. Micro-photoluminescence spectroscopic studies reveal that on the interlayer interactions in double layer MoS 2 crystals, the emission quantum yield of the A exciton is drastically changed, whereas that of the B exciton remains nearly constant for both single and double layer MoS 2 crystals. First-principles density functional theory calculations confirm that a significant charge redistribution occurs in the double layer MoS 2 due to the interlayer interactions producing a local electric field at the interfacial region. Analogous to the quantum-confined Stark effect, we suggest that the distinct behavior of the A and B excitons can be explained by a simplified band-bending model.1

Optical spectroscopic investigation on the coupling of electronic and magnetic structure in multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

We investigated the effects of temperature and magnetic field on the electronic structure of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using optical spectroscopy. As the magnetic ordering of the system was disturbed, a systematic change in the electronic structure was commonly identified in this series. The optical absorption peak near 1.7 eV showed an unexpectedly large shift of more than 150 meV from 300 K to 15 K, accompanied by an anomaly of the shift at the Neel temperature. The magnetic field dependent measurement clearly revealed a sizable shift of the corresponding peak when a high magnetic field was applied. Our findings indicated strong coupling between the magnetic ordering and the electronic structure in the multiferroic hexagonal RMnO3 compounds.Comment: 16 pages including 4 figure

Rectifying the Optical-Field-Induced Current in Dielectrics: Petahertz Diode

Investigating a theoretical model of the optical-field-induced current in dielectrics driven by strong few-cycle laser pulses, we propose an asymmetric conducting of the current by forming a heterojunction made of two distinct dielectrics with a low hole mass (m(h)(*) << m(e)(*)) and low electron mass (m(e)(*) << m(h)(*)), respectively. This proposition introduces the novel concept of a petahertz (10(15) Hz) diode to rectify the current in the petahertz domain, which should be a key ingredient for the electric signal manipulation of future light-wave electronics. Further, we suggest the candidate dielectrics for the heterojunction.open

Precise stacking of decellularized extracellular matrix based 3D cell-laden constructs by a 3D cell printing system equipped with heating modules

Three-dimensional (3D) cell printing systems allow the controlled and precise deposition of multiple cells in 3D constructs. Hydrogel materials have been used extensively as printable bioinks owing to their ability to safely encapsulate living cells. However, hydrogel-based bioinks have drawbacks for cell printing, e.g. inappropriate crosslinking and liquid-like rheological properties, which hinder precise 3D shaping. Therefore, in this study, we investigated the influence of various factors (e.g. bioink concentration, viscosity, and extent of crosslinking) on cell printing and established a new 3D cell printing system equipped with heating modules for the precise stacking of decellularized extracellular matrix (dECM)-based 3D cell-laden constructs. Because the pH-adjusted bioink isolated from native tissue is safely gelled at 37 degrees C, our heating system facilitated the precise stacking of dECM bioinks by enabling simultaneous gelation during printing. We observed greater printability compared with that of a non-heating system. These results were confirmed by mechanical testing and 3D construct stacking analyses. We also confirmed that our heating system did not elicit negative effects, such as cell death, in the printed cells. Conclusively, these results hold promise for the application of 3D bioprinting to tissue engineering and drug development.119Ysciescopu

Granular Cell Tumor of the Urinary Bladder

A 67-year-old Korean man presented with gross, painless hematuria that had lasted for the previous 2 months. Cystoscopy showed a semispherical tumor approximately 1 cm in diameter that was covered with normal bladder mucosa and extended from the bladder neck to the posterior wall of the bladder. The patient underwent transurethral resection of the tumor. Histological examination and immunohistochemical staining showed a granular cell tumor (GCT). There were no features suggesting a malignant phenotype. On follow-up, the patient has remained free of bladder recurrence. We herein report this case of a GCT of the urinary bladder and review the literature

Antimicrobial peptide from Bacillus subtilis CSB138: characterization, killing kinetics, and synergistic potency

We studied the prospect of synergy between the antimicrobial peptide p138c and non-peptide antibiotics for increasing the potency and bacterial killing kinetics of these agents. The production of p138c was maximized in the late exponential growth phase of Bacillus subtilis CSB138. Purification of p138c resulted in a total of 4800 arbitrary units (AU) with 19.15-fold and 3.2% recovery. Peptide p138c was thermo-tolerant up to 50 °C and stable at pH 5.8 to 11. The biochemical nature of p138c was determined by a bioassay, similar to tricine-SDS-PAGE, indicating inhibition at 3 kDa. The amino acid sequence of p138c was Gly-Leu-Glu-Glu-Thr-Val-Tyr-Ile-Tyr-Gly-Ala-Asn-Met-X-Ser. Potency and killing kinetics against vancomycin-resistant Staphylococcus aureus improved considerably when p138c was synergized with oxacillin, ampicillin, and penicillin G. The minimal inhibitory concentration (MIC) of p138c showed a 4-, 8-, and 16-fold improvement when p138c was combined with oxacillin, ampicillin, and penicillin G, respectively. The fractional inhibitory concentration index for the combination of p138c and oxacillin, ampicillin, and penicillin G was 0.3125, 0.25, and 0.09, respectively. Synergy with non-peptide antibiotics resulted in enhanced killing kinetics of p138c. Hence, the synergy between antimicrobial peptide and non-peptide antibiotics may enhance the potency and bacterial killing kinetics, providing more potent and rapidly acting agents for therapeutic use. [Int Microbiol 20(1):43-53 (2017)]Keywords: Bacillus subtilis · antimicrobial peptides · killing kinetic

Decreased DBC1 Expression Is Associated With Poor Prognosis in Patients With Non-Muscle-Invasive Bladder Cancer

Purpose The deleted in bladder cancer 1 (DBC1) gene is located within chromosome 9 (9q32-33), a chromosomal region that frequently shows loss of heterozygosity in bladder cancer (BC). It is suspected that it acts as a tumor suppressor gene, but its prognostic value remains unclear. The aim of the present study was to investigate the value of DBC1 as a prognostic marker in BC. Materials and Methods The expression of DBC1 was determined by real-time polymerase chain reaction analysis in 344 patients with BC (220 non-muscle-invasive BC [NMIBC] and 124 muscle-invasive BC [MIBC]) and in 34 patients with normal bladder mucosa. The results were compared with clinicopathologic parameters, and the prognostic value of DBC1 was evaluated by Kaplan-Meier analysis and a multivariate Cox regression model. Results: DBC1 expression was significantly decreased in patients with MIBC compared with those diagnosed with NMIBC (p=0.010). Patients with aggressive tumor characteristics had lower DBC1 expression levels in NMIBC (each, p<0.05). By multivariate Cox regression analysis, low DBC1 expression was a predictor of progression to MIBC (hazard ratio, 7.104; p=0.013). Kaplan-Meier estimates revealed a significant difference in tumor recurrence, progression to MIBC, and cancer-specific survival depending on the level of DBC1 expression in NMIBC (log-rank test, each, p<0.05). Conclusions: The expression of DBC1 was associated with tumor aggressiveness, progression to MIBC, and survival in NMIBC. Our results suggest that DBC1 expression can be a useful prognostic marker for patients with NMIBC

C-terminally mutated tubby protein accumulates in aggresomes

The tubby protein (Tub), a putative transcription factor, plays important roles in the maintenance and function of neuronal cells. A splicing defect-causing mutation in the 3&apos;-end of the tubby gene, which is predicted to disrupt the carboxy-terminal region of the Tub protein, causes maturity-onset obesity, blindness, and deafness in mice. Although this pathological Tub mutation leads to a loss of function, the precise mechanism has not yet been investigated. Here, we found that the mutant Tub proteins were mostly localized to puncta found in the perinuclear region and that the C-terminus was important for its solubility. Immunocytochemical analysis revealed that puncta of mutant Tub co-localized with the aggresome. Moreover, whereas wild-type Tub was translocated to the nucleus by extracellular signaling, the mutant forms failed to undergo such translocation. Taken together, our results suggest that the malfunctions of the Tub mutant are caused by its misfolding and subsequent localization to aggresomes.ope