Carrier transport mechanisms of hybrid ZnO nanorod-polymer LEDs

A hybrid polymer-nanorod (NR) light-emitting diode (LED), consisting of a hole-conducting polymer poly (9-vinyl carbazole) (PVK) and ZnO nanorod (NR) composite, with the device structure of glass/indium-tin-oxide (ITO)/PEDOT:PSS/(PVK + ZnO nanorods)/Al is fabricated through a simple spin coating technique. TEM images shows inhomogeneous deposition and the agglomeration of ZnO NRs, which is explained through their low probability of adsorption on PVK due to two-dimensional structural property. In the current-voltage characteristics, negative differential resistance (NDR) phenomenon is observed corresponding to device structure without ZnO NRs. The carrier transport behavior in the LED device is well described by both ohmic and space-chargelimited-current (SCLC) mechanisms. Broad blue electroluminescence (EL) consisting of two sub peaks, are centered at 441 nm and the other at 495 nm, is observed, which indicates that the ZnO nanorod play a role as a recombination center for excitons. The red shift in the position of the EL compared to that photoluminescence is well explained through band offsets at the heterojunction between the PVK and ZnO NRs

Burst Packet Loss Concealment Using Multiple Codebooks and Comfort Noise for CELP-Type Speech Coders in Wireless Sensor Networks

In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed in order to improve the quality of decoded speech under burst packet loss conditions in a wireless sensor network. Conventional receiver-based PLC algorithms in the G.729 speech codec are usually based on speech correlation to reconstruct the decoded speech of lost frames by using parameter information obtained from the previous correctly received frames. However, this approach has difficulty in reconstructing voice onset signals since the parameters such as pitch, linear predictive coding coefficient, and adaptive/fixed codebooks of the previous frames are mostly related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook-based approach that includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm currently employed in G.729 via a perceptual evaluation of speech quality, a waveform comparison, and a preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC algorithm employed in G.729 under all the test conditions

Chronic Pelvic Paragonimiasis: Radiological Findings

Two cases of ectopic paragonimiasis involving pelvic peritoneal cavity and omentum were confirmed surgically and pathologically, The lesions were manifested as nodules of faintly calcified periphery on various imaging modalities. Ectopic paragonimiasis should be included in the differential diagnosis of nodular calcifications in the pelvic cavity

Synchronous double primary cancers associated with a choledochal cyst and anomalous pancreaticobiliary ductal union

A 60-year-old female was admitted with epigastric pain lasting a month. Preoperative diagnosis was choledochal cyst with anomalous pancreaticobiliaryductal union (APBDU), C-P type. A papillary mass measuring 2.5 × 1.9 cm was found adjacent to the pancreaticocholedochal junction. Gallbladder (GB) cancer was also observed. Pyloric-preserving pancreaticoduodenectomy (PPPD) was performed. The patient received adjuvant chemotherapy/radiation therapy on the tumor bed. The gallbladder cancer showed serosal invasion, while the bile duct cancer extended into the pancreas. Although common bile duct (CBD) cancer lesion showed focally positive for p53 and the gallbladder cancer lesion showed negative for p53, the Ki-67 labeling index of the CBD cancer and GB cancer were about 10% and 30%, respectively. Nine months after curative resection, a stricture on the subhepatic colon developed due to adjuvant radiation therapy. Localized peritoneal seedings were incidentally found during a right hemicolectomy. The patient underwent chemotherapy and had no evidence of tumor recurrence for two years after PPPD

Natural Course of Allergic and Nonallergic Rhinitis After 2 Years in Korean Children

Objectives. Allergic and nonallergic rhinitis are very common disease for children, however, little is known about their natural courses in the general population. The purpose is to evaluate the natural course of allergic and nonallergic rhinitis in children. Methods. We analyzed data from Snoring Child Cohort of 178 children (107 boys and 71 girls). All children entered the study at the age of 7 years (range, 6.5 to 7.4 years). Questionnaires regarding chronic rhinitis, a skin prick test (SPT) for 5 inhalent allergens, and specific IgE for 2 dust mites were administered. Children were classified into 4 groups: allergic rhinitis (rhinitis, positive SPT), nonallergic rhinitis (rhinitis, negative SPT), sensitization only (no rhinitis, positive SPT), and control (no rhinitis, negative SPT). We repeated follow them annually, and analyzed the data of first and third year for this study. Results. Finally, the data of 122 children were analyzed. Among 18 children with allergic rhinitis at 7 years, 13 (72%) became sensitization only after 2 years and 5 (28%) were remained having allergic rhinitis. Five out of 19 children (26%) with nonallergic rhinitis developed into allergic rhinitis and 7 (37%) into control at 9 years. Twenty-four out of 28 children (86%) with sensitization only at 7 years remained the same at 9 years. Among 57 control children at 7 years, 2 (4%) developed into allergic rhinitis, 7 (12%) with nonallergic rhinitis, and 16 (28%) with sensitization only at 9 years. Conclusion. The status of chronic rhinitis and allergen sensitization is ever-changing in children

Variability of extracorporeal cardiopulmonary resuscitation utilization for refractory adult out-of-hospital cardiac arrest: an international survey study.

Objective: A growing interest in extracorporeal cardiopulmonary resuscitation (ECPR) as a rescue strategy for refractory adult out-of-hospital cardiac arrest (OHCA) currently exists. This study aims to determine current standards of care and practice variation for ECPR patients in the USA and Korea. Methods: In December 2015, we surveyed centers from the Korean Hypothermia Network (KORHN) Investigators and the US National Post-Arrest Research Consortium (NPARC) on current targeted temperature management and ECPR practices. This project analyzes the subsection of questions addressing ECPR practices. We summarized survey. Results: Overall, 9 KORHN and 4 NPARC centers reported having ECPR programs and had complete survey data available. Two KORHN centers utilized extracorporeal membrane oxygenation only for postarrest circulatory support in patients with refractory shock and were excluded from further analysis. Centers with available ECPR generally saw a high volume of OHCA patients (10/11 centers care for \u3e75 OHCA a year). Location of, and providers trained for cannulation varied across centers. All centers in both countries (KORHN 7/7, NPARC 4/4) treated comatose ECPR patients with targeted temperature management. All NPARC centers and four of seven KORHN centers reported having a standardized hospital protocol for ECPR. Upper age cutoff for eligibility ranged from 60 to 75 years. No absolute contraindications were unanimous among centers. Conclusion: A wide variability in practice patterns exist between centers performing ECPR for refractory OHCA in the US and Korea. Standardized protocols and shared research databases might inform best practices, improve outcomes, and provide a foundation for prospective studies