Reducing a Piezoelectric Field in InGaN Active Layers by Varying Pattern Sapphire Substrates

Internal quantum efficiency (IQE) and piezoelectricfield (PZ) in InGaN light-emitting diodes (LEDs) were analyzedthat were grown on a truncated pyramid (TP)- and a pyramid(P)-shaped pattern sapphire substrates. Lower flat-band voltagewas measured at −8 V in the P-LED compared with the TP-LED(−12 V) that showed a low PZ was observed in the P-LEDstructure. The IQE value of the P-LED was measured as 86%,which is higher than that of the TP-LED (76%). High IQE, lowPZ, and high light extraction efficiency were observed in theInGaN LED structure grown on the P-shaped pattern sapphiresubstrate

Prothymosin α overexpression contributes to the development of pulmonary emphysema

Emphysema is one of the disease conditions that comprise chronic obstructive pulmonary disease. Prothymosin α transgenic mice exhibit an emphysema phenotype, but the pathophysiological role of prothymosin α in emphysema remains unclear. Here we show that prothymosin α contributes to the pathogenesis of emphysema by increasing acetylation of histones and nuclear factor-kappaB, particularly upon cigarette smoke exposure. We find a positive correlation between prothymosin α levels and the severity of emphysema in prothymosin α transgenic mice and emphysema patients. Prothymosin α overexpression increases susceptibility to cigarette smoke-induced emphysema, and cigarette smoke exposure further enhances prothymosin α expression. We show that prothymosin α inhibits the association of histone deacetylases with histones and nuclear factor-kappaB, and that prothymosin α overexpression increases expression of nuclear factor-kappaB-dependent matrix metalloproteinase 2 and matrix metalloproteinase 9, which are found in the lungs of patients with chronic obstructive pulmonary disease. These results demonstrate the clinical relevance of prothymosin α in regulating acetylation events during the pathogenesis of emphysema

Solution-processed Li–Al layered-doublehydroxide platelet structures for high efficiency InGaN light emitting diodes

High-oriented Li–Al layered double hydroxide (LDH) films were grown on an InGaN light-emitting diode (LED) structures by immersing in an aqueous alkaline Al3+- and Li+-containing solution. The stand upward and adjacent Li-Al LDH platelet structure was formed on the LED structure as a textured film to increase the light extraction efficiency. The light output power of the LED structure with the Li-Al LDH platelet structure had a 31% enhancement compared with a conventional LED structure at 20 mA. The reverse leakage currents, at -5V, were measured at - 2.3×10-8A and -1.0×10-10A for the LED structures without and with the LDH film that indicated the Li-Al LDH film had the insulated property acted a passivation layer that had potential to replace the conventional SiO2 and Si3N4 passivation layers. The Li-Al LDH layer had the textured platelet structure and the insulated property covering whole the LED surface that has potential for high efficiency InGaN LED applications

Fabricated InGaN Membranes through a Wet Lateral Etching Process

Epitaxial layers of InGaN light-emitting diodes (LED) were separated from undoped GaN/sapphire structures through a wet lift-off process. A 0.1-µm-thick Si-heavy-doped GaN:Si (n+-GaN) layer was inserted in the InGaN LED structure that acted as a sacrificial layer for a lateral wet etching process. The lateral etching rate of the n+-GaN sacrificial layer was 315 µm/h. The Fabry–Pérot interferences of the lift-off InGaN LED membranes were observed in the angle-resolved photoluminescence spectra that indicated that the lift-off InGaN membranes had a flat etched surface. High light extraction efficiency, narrow divergent angle, and flat wet-etched GaN surface were observed on the lift-off InGaN membrane

InGaN-based Light-Emitting Diodes with a Sawtooth-shaped Sidewall on Sapphire Substrate

An InGaN light emitting diode (LED) with a cone-shaped GaN structure and a sawtooth-shaped sapphire sidewall structure was fabricated through a laser-drilling process. The fabricated procedures consisted of a laser scribing/drilling process, a wet etching process, and a chip cleaving process. In the treated LED structure with the laser-drilling sawtooth-shaped sidewall, the light output power had a 16% enhancement compared to a conventional LED structure with a laser-scribing sidewall. A periodic high light emission intensity, with a 2.6μm-width spaced at regular intervals of 3.8μm, was observed on the treated LED sidewall structure corresponding to the laser-drilling patterns. The LED structure consists of a laser-drilling sidewall and a cone-shaped GaN structure that increases the light extraction efficiency for high efficiency InGaN LED applications

Bendable InGaN Light-Emitting Nanomembranes with Tunable Emission Wavelength

The integration of light-emitting diodes (LEDs) into the flexible devices has exhibited a great potential in the next-generation consumer electronics. In this study, we have demonstrated an exfoliated InGaN nanomembrane LED (NM-LED) separated from a GaN/sapphire substrate through an electrochemically wet etching process. The peak wavelengths blue-shifted phenomenon of the photoluminescence (PL) and the electroluminescence spectra were observed on the free-standing NM-LED compared to the nontreated LED with the same structure, which can be ascribed to the partial strain relaxation of the LED structure confirmed by the Raman spectra and the X-ray diffraction curves. A small divergent angle of the PL emission light has also been observed on the NM-LED. Moreover, the peak emission wavelength of this NM-LED can be even modulated from a red shift (521.7 nm) to a blue shift (500.4 nm) compared with that of the flat state (509.4 nm) while being curved convexly from top p-GaN:Mg side to bottom n-GaN:Si side. Our study provides an elegant way to develop a bendable light source with variable emission wavelengths through the mechanical deformation method

Syngeneic mesenchymal stem cells loaded with telomerase-dependent oncolytic adenoviruses enhance anti-metastatic efficacy.

Oncolytic adenoviruses have emerged as a promising therapeutic approach for cancer therapy. However, systemic delivery of the viruses to metastatic tumors remains a major challenge. Mesenchymal stem cells (MSCs) possess tumor tropism property and can be used as cellular vehicles for delivering oncolytic adenoviruses to tumor sites. Since telomerase activity is found in ~90% of human carcinomas, but undetected in normal adult cells, the human telomerase reverse transcriptase gene (TERT) promoter can be exploited for regulating the replication of oncolytic adenoviruses. Here, we evaluated the antitumor effects of syngeneic murine MSCs loaded with the luciferase-expressing, telomerase-dependent oncolytic adenovirus Ad.GS2 (MSC-Ad.GS2) and Ad.GS2 alone on metastatic MBT-2 bladder tumors. MSCs supported a low degree of Ad.GS2 replication, which could be augmented by coculture with MBT-2 cells or tumor-conditioned medium (TCM), suggesting that viral replication is increased when MSC-Ad.GS2 migrates to tumor sites. MBT-2 cells and TCM enhanced viral replication in Ad.GS2-infected MSCs. SDF-1 is a stem cell homing factor. Our results suggest that the SDF-1/STAT3/TERT signaling axis in MSCs in response to the tumor microenvironment may contribute to the enhanced replication of Ad.GS2 carried by MSCs. Notably, we demonstrate the potent therapeutic efficacy of systemically delivered MSC-Ad.GS2 in pleural disseminated tumor and experimental metastasis models using intrapleural and tail vein injection of MBT-2 cells, respectively. Treatment with MSC-Ad.GS2 significantly reduced tumor growth and prolonged the survival of mice bearing metastatic bladder tumors. Since telomerase is expressed in a broad spectrum of cancers, this therapeutic strategy may be broadly applicable. [Abstract copyright: © The Author(s) 2024. Published by Oxford University Press.

A Novel Detection Platform for Shrimp White Spot Syndrome Virus Using an ICP11-Dependent Immunomagnetic Reduction (IMR) Assay

<div><p>Shrimp white spot disease (WSD), which is caused by white spot syndrome virus (WSSV), is one of the world’s most serious shrimp diseases. Our objective in this study was to use an immunomagnetic reduction (IMR) assay to develop a highly sensitive, automatic WSSV detection platform targeted against ICP11 (the most highly expressed WSSV protein). After characterizing the magnetic reagents (Fe₃O₄ magnetic nanoparticles coated with anti ICP11), the detection limit for ICP11 protein using IMR was approximately 2 x 10⁻³ ng/ml, and the linear dynamic range of the assay was 0.1~1 x 10⁶ ng/ml. In assays of ICP11 protein in pleopod protein lysates from healthy and WSSV-infected shrimp, IMR signals were successfully detected from shrimp with low WSSV genome copy numbers. We concluded that this IMR assay targeting ICP11 has potential for detecting the WSSV.</p></div

Fabrication of current confinement aperture structure by transforming a conductive GaN:Si epitaxial layer into an insulating GaOx layer

We report here a simple and robust process to convert embedded conductive GaN epilayers into insulating GaOx and demonstrate its efficacy in vertical current blocking and lateral current steering in a working LED device. The fabrication processes consist of laser scribing, electrochemical (EC) wet-etching, photoelectrochemical (PEC) oxidation, and thermal oxidization of a sacrificial n(+)-GaN:Si layer. The conversion of GaN is made possible through an intermediate stage of porosification where the standard n-type GaN epilayers can be laterally and selectively anodized into a nanoporous (NP) texture while keeping the rest of the layers intact. The fibrous texture of NP GaN with an average wall thickness of less than 100 nm dramatically increases the surface-to-volume ratio and facilitates a rapid oxidation process of GaN into GaOX. The GaOX aperture was formed on the n-side of the LED between the active region and the n-type GaN layer. The wavelength blueshift phenomena of electroluminescence spectra is observed in the treated aperture-emission LED structure (441.5 nm) when compared to nontreated LED structure (443.7 nm) at 0.1 mA. The observation of aperture-confined electroluminescence from an InGaN LED structure suggests that the NP GaN based oxidation will play an enabling role in the design and fabrication of III-nitride photonic devices