Electroluminescent devices with function of electro-optic shutter

The polymer-dispersed liquid crystal (PDLC) was used as a dielectric layer of electroluminescent (EL) device to provide multi-function of electroluminescence and electro-optic shutter. A 50 μm-thick PDLC layer was formed between a transparent electrode and a ZnS:Cu phosphor layer. The electro-optic properties of the EL device were not distorted by the introduction of the PDLC layer. The extraction efficiency of luminescence was improved by more than 14% by PDLC layer. The transmittance of the PDLC was also founded not to be degraded significantly by excitation frequency. Therefore, the electroluminescence of the device was ignited by excitation frequency at a given voltage for full transparency of the PDLC. This device has great potential for applications in transparent displays with the function of a privacy window. © 2012 Optical Society of America.1

Bidirectional two colored light emission from stress-activated ZnS-microparticles-embedded polydimethylsiloxane elastomer films

Bidirectional two-colored mechanoluminescent light emission has been demonstrated by unifying two polydimethylsiloxane elastomer layers functionalized with zinc sulfide doped with Cu (ZnS:Cu) or Cu and Mn (ZnS:Cu,Mn). The bilayered composite films are simply fabricated by dispensing uncured ZnS:Cu,Mn + PDMS onto previously spin-coated and ardened ZnS:Cu + PDMS film. The robust PDMS-PDMS bonding yields a ilm which can simultaneously emit light with color coordinates of (0.25, 0.56) and (0.50, 0.48), similar to the intrinsic colors of ZnS:Cu and ZnS:Cu,Mn, respectively. Composite films can emit light in upper and lower directions without fracture when it is stretched. © 2013 Optical Society of America.1

Luminance enhancement of electroluminescent devices using highly dielectric UV-curable polymer and oxide nanoparticle composite

A flexible hybrid structure electroluminescent (HSEL) device was fabricated from ZnS:Cu phosphor microparticles dispersed in a UVcurable polymer matrix. We observed a maximum luminance of 111 cd/m2 at 10 kHz and 170 V from a device wherein the mixing ratio between the phosphor particles and highly dielectric polymer binder was 70:30 wt%. Furthermore, by uniformly dispersing highly dielectric BaTiO3 nanoparticles within the polymer matrix, we were able to obtain a luminance of up to 211 cd/m2 in the HSEL device. Compared to the conventional thermal curing process, this UV process greatly simplifies the fabrication steps by combining phosphors and dielectric materials at room temperature. This process also demonstrates a promising pathway toward creating flexible and printed EL devices in the future. © 2014 Optical Society of America.1

Enhanced blue photoluminescence realized by copper diffusion doping of ZnO thin films

ZnO thin films with blue photoluminescence (PL) have been fabricated through Cu diffusion doping. A CuOx-ZnO mixture, and Cu/ZnO double layer, films were prepared on amorphous SiOx/Si substrates by pulsed laser deposition (PLD), and electron beam (e-beam) deposition, respectively. After sequential oxygen annealing, CuOx-ZnO mixture films exhibited green emission centered at 523 nm. However, Cu/ZnO double layer films differed in producing a blue emission centered at 480 nm. Detailed analysis identified that this blue shift in the emission center resulted from increased blue emissions attributed to Cu dopants in the film by e-beam deposition. Luminescence intensity was increased to 6 cd/m2 for a sample annealed at 700 deg;C. Color points were close to the locus of points following the line of a black-body-radiator on the CIE 1931 XY chromaticity diagram. The present results show that Cu-doped ZnO has strong potential as a cost effective phosphor for use in down converting LEDs. © 2013 Optical Society of America.1

Electrically tunable birefringence of a polymer composite with long-range orientational ordering of liquid crystals

We report an optical film with electrically tunable birefringence in which the liquid crystals (LCs), mixed with the host polymer, form longrange ordering. The film was prepared through polymerization without phase separation between the LCs and polymers. Driving voltage below 30 V for full switching of birefringence is achieved in a 6 μm-thick film. Electro-optical investigations for the film suggest that the long-range ordering of the LCs mixed in the film caused by polymerization lead to rotations of the LCs as well as optical anisotropy in the film. These films with electrically tunable birefringence could have applications as flexible light modulators and phase retardation films for 2D-3D image switching. © 2014 Optical Society of America.1

Superparamagnetic Iron Oxide Nanoparticles Coated with Galactose-Carrying Polymer for Hepatocyte Targeting

Our goal is to develop the functionalized superparamagnetic iron oxide nanoparticles (SPIONs) demonstrating the capacities to be delivered in liver specifically and to be dispersed in physiological environment stably. For this purpose, SPIONs were coated with polyvinylbenzyl-O-β-D-galactopyranosyl-D-gluconamide (PVLA) having galactose moieties to be recognized by asialoglycoprotein receptors (ASGP-R) on hepatocytes. For use as a control, we also prepared SPIONs coordinated with 2-pyrrolidone. The sizes, size distribution, structure, and coating of the nanoparticles were characterized by transmission electron microscopy (TEM), electrophoretic light scattering spectrophotometer (ELS), X-ray diffractometer (XRD), and Fourier transform infrared (FT-IR), respectively. Intracellular uptake of the PVLA-coated SPIONs was visualized by confocal laser scanning microscopy, and their hepatocyte-specific delivery was also investigated through magnetic resonance (MR) images of rat liver. MRI experimental results indicated that the PVLA-coated SPIONs possess the more specific accumulation property in liver compared with control, which suggests their potential utility as liver-targeting MRI contrast agent

Efficacy evaluation of combination vaccine of recombinant C-terminal fragments of ApxIA, ApxIIA and ApxIIIA in piglets

The efficacy of the combination vaccine of the individual C-terminal fragments of ApxIA, ApxIIA and ApxIIIA of Actinobacillus pleuropneumoniae (APP) was evaluated in piglets. Twenty piglets were divided equally into 2 groups (n=10). All piglets were intramuscularly primed at 4 week-of-age (0 week post prime inoculation (WPPI)) and were intramuscularly boosted at 6 week-of-age (2 WPPI). Group A piglets were inoculated with sterile PBS and group B piglets were inoculated with the combination vaccine. Concentrations of each of the C-terminal fragment-specific IgG as determined by ELISA were significantly higher in group B than in group A from 2 WPPI until the end of this study. Clinical signs were observed from only 10% of group B piglets after the challenge with the mixture of APP serotypes 1, 2 and 5 at 4 WPPI, while 50% of group A piglets were protected against APP infections. Overall, intramuscular inoculation with the vaccine candidate can efficiently protect piglets against APP infection

Effect of blood pressure and glycemic control on the plasma cell-free DNA in hemodialysis patients

AbstractBackgroundThe plasma levels of cell-free DNA (cfDNA) are known to be elevated under inflammatory or apoptotic conditions. Increased cfDNA levels have been reported in hemodialysis (HD) patients. The aim of this study was to investigate the clinical significance of cfDNA in HD patients.MethodsA total of 95 patients on HD were enrolled. We measured their predialysis cfDNA levels using real-time EIF2C1 gene sequence amplification and analyzed its association with certain clinical parameters.ResultsThe mean plasma cfDNA level in the HD patients was 3,884 ± 407 GE/mL, and the mean plasma cfDNA level in the control group was 1,420 ± 121 GE/mL (P < 0.05). Diabetic patients showed higher plasma cfDNA levels compared with nondiabetic patients (P < 0.01). Patients with cardiovascular complications also showed higher plasma cfDNA levels compared with those without cardiovascular complication (P < 0.05). In univariable analysis, the cfDNA level was associated with 3-month mean systolic blood pressure (SBP), white blood cell, serum albumin, creatinine (Cr), normalized protein catabolic rate in HD patients. In diabetic patients, it was significantly correlated with SBP, hemoglobin A1c, and serum albumin. In multivariate analysis, SBP was the independent determinant for the cfDNA level. In diabetic patients, cfDNA level was independently associated with hemoglobin A1c and SBP.ConclusionsIn patients with HD, cfDNA is elevated in diabetic patients and patients with cardiovascular diseases. Uncontrolled hypertension and poor glycemic control are independent determinants for the elevated cfDNA. Our data suggest that cfDNA might be a marker of vascular injury rather than proinflammatory condition in HD patients

Quality of Service Control for WLAN-based Converged Personal Network Service

This paper proposes a framework for quality of service (QoS) control in WLAN-based converged personal network service (CPNS). First, we show that the CPNS devices in WLANs occupy the shared wireless channel in an unfair manner; and thus, QoS is degraded. The reasons of such problem are analyzed from two viewpoints of (i) channel access mechanism according to carrier sensing multiple access protocol of WLAN and (ii) TCP congestion control mechanism in response to packet loss. To improve QoS and assure fair channel sharing, we propose an integrated QoS control framework consisting of admission control and rate control. Based on the available capacity, the admission control determines whether or not a specific QoS service can be admitted. The rate control is implemented using congestion window control or token bucket algorithm. The proposed mechanism differentiates QoS service from best-effort (BE) service such that the QoS service is preferentially served to satisfy its QoS requirements and the BE service is served to share the remaining resource in a fair manner. The extensive simulation results confirm that the proposed scheme assures QoS and fair channel sharing for WLAN-based CPNS