In-rich InGaN/GaN quantum wells grown by metal-organic chemical vapor deposition

Growth mechanism of In-rich InGaN/GaN quantum wells (QWs) was investigated. First, we examined the initial stage of InN growth on GaN template considering strain-relieving mechanisms such as defect generation, islanding, and alloy formation at 730 degrees C. It was found that, instead of formation of InN layer, defective In-rich InGaN layer with thickness fluctuations was formed to relieve large lattice mismatch over 10% between InN and GaN. By introducing growth interruption (GI) before GaN capping at the same temperature, however, atomically flat InGaN/GaN interfaces were observed, and the quality of In-rich InGaN layer was greatly improved. We found that decomposition and mass transport processes during GI in InGaN layer are responsible for this phenomenon. There exists severe decomposition in InGaN layer during GI, and a 1-nm-thick InGaN layer remained after GI due to stronger bond strength near the InGaN/GaN interface. It was observed that the mass transport processes actively occurred during GI in InGaN layer above 730 degrees C so that defect annihilation in InGaN layer was greatly enhanced. Finally, based on these experimental results, we propose the growth mechanism of In-rich InGaN/GaN QWs using GI.open9

Observation of oxide precipitates in InN nanostructures

We observed the formation of oxide precipitates (bcc-In(2)O(3)) in InN nanostructures formed during metal-organic chemical vapor deposition (MOCVD) and/or subsequent postgrowth procedures in H(2) ambient. It was found that InN is extremely unstable in H(2) ambient and the activation energy of N(2) desorption of InN is measured to be similar to 0.28 eV, which is one order of magnitude smaller than that of reported value of InN in vacuum. Instability of InN nanostructures under H(2) ambient together with residual oxidant in the reactor facilitates the formation of indium oxide precipitates in the nanostructure matrix during MOCVD or the oxidation of residual indium at the surface, resulting in indium oxide dots.open3

Clinical Impact of Viral Load on the Development of Hepatocellular Carcinoma and Liver-Related Mortality in Patients with Hepatitis C Virus Infection

Aim. This study aimed to assess clinical impact of hepatitis C viral load on the development of hepatocellular carcinoma (HCC) and liver-related mortality in HCV-infected patients. Methods. A total of 111 subjects with chronic HCV infection who were available for serum quantitation of HCV RNA were recruited in this retrospective cohort. Cox-proportional hazards models were used to calculate hazard ratio (HR) of developing HCC and liver-related mortality according to serum HCV RNA titers. Results. HCC was developed in 14 patients during follow-up period. The cumulative risk of HCC development was higher in subjects with high HCV RNA titer (log HCV RNA IU/mL > 6) than subjects with low titer (log HCV RNA IU/mL ≦ 6) (HR = 4.63, P=0.032), giving an incidence rate of 474.1 and 111.5 per 10,000 person-years, respectively. Old age (HR = 9.71, P=0.014), accompanying cirrhosis (HR = 19.34, P=0.004), and low platelet count (HR = 13.97, P=0.009) were other independent risk factors for the development of HCC. Liver-related death occurred in 7 patients. Accompanying cirrhosis (HR = 6.13, P=0.012) and low albumin level (HR = 9.17, P=0.002), but not HCV RNA titer, were significant risk factors related to liver-related mortality. Conclusion. Serum HCV RNA titer may be considered an independent risk factor for the development of HCC but not liver-related mortality

Admission levels of high-density lipoprotein and apolipoprotein A-1 are associated with the neurologic outcome in patients with out-of-hospital cardiac arrest

Objective To investigate whether serum levels of high-density lipoprotein (HDL) and apolipoprotein A-1 (ApoA1), after the return of spontaneous circulation, can predict the neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA). Methods This was a retrospective observational study conducted in a single tertiary hospital intensive care unit. All adult OHCA survivors with admission lipid profiles were enrolled from March 2013 to December 2015. Good neurologic outcome was defined as discharge cerebral performance categories 1 and 2. Results Among 59 patients enrolled, 13 (22.0%) had a good neurologic outcome. Serum levels of HDL (56.7 vs. 40 mg/dL) and ApoA1 (117 vs. 91.6 mg/dL) were significantly higher in patients with a good outcome. Areas under the HDL and ApoA1 receiver operating curves to predict good outcomes were 0.799 and 0.759, respectively. The proportion of good outcome was significantly higher in patients in higher tertiles of HDL and ApoA1 (test for trend, both P=0.003). HDL (P=0.018) was an independent predictor in the multivariate logistic regression model. Conclusion Admission levels of HDL and ApoA1 are associated with neurologic outcome in patients with OHCA. Prognostic and potential therapeutic values of HDL and ApoA1 merit further evaluation in the post-cardiac arrest state, as in other systemic inflammatory conditions such as sepsis

Temporal Trends of Emergency Department Visits of Patients with Atrial Fibrillation:A Nationwide Population-Based Study

The question of list decoding error-correcting codes over finite fields (under the Hamming metric) has been widely studied in recent years. Motivated by the similar discrete linear structure of linear codes and point lattices in R N, and their many shared applications across complexity theory, cryptography, and coding theory, we initiate the study of list decoding for lattices. Namely: for a lattice L ⊆ R N, given a target vector r ∈ R N and a distance parameter d, output the set of all lattice points w ∈ L that are within distance d of r. In this work we focus on combinatorial and algorithmic questions related to list decoding for the well-studied family of Barnes-Wall lattices. Our main contributions are twofold: 1. We give tight (up to polynomials) combinatorial bounds on the worst-case list size, showing it to be polynomial in the lattice dimension for any error radius bounded away from the lattice’s minimum distance (in the Euclidean norm). 2. Building on the unique decoding algorithm of Micciancio and Nicolosi (ISIT ’08), we give a list-decoding algorithm that runs in time polynomial in the lattice dimension and worst-case list size, for any error radius. Moreover, our algorithm is highly parallelizable, and with sufficiently many processors can run in parallel time only poly-logarithmic in the lattice dimension. In particular, our results imply a polynomial-time list-decoding algorithm for any error radius bounded away from the minimum distance, thus beating a typical barrier for natural error-correcting codes posed by the Johnson radius

Quick Sepsis-related Organ Failure Assessment score is not sensitive enough to predict 28-day mortality in emergency department patients with sepsis: a retrospective review

Objective To test the hypothesis that the quick Sepsis-related Organ Failure Assessment (qSOFA) score, derived from vital signs taken during triage and recommended by current sepsis guidelines for screening patients with infections for organ dysfunction, is not sensitive enough to predict the risk of mortality in emergency department (ED) sepsis patients. Methods Patients diagnosed with severe sepsis and septic shock using the old definition between May 2014 and April 2015 were retrospectively reviewed in three urban tertiary hospital EDs. The sensitivities of systemic inflammatory response syndrome (SIRS) criteria, qSOFA, and Sequential Organ Failure Assessment (SOFA) scores ≥2 were compared using McNemar’s test. Diagnostic performances were evaluated using specificity, positive predictive value, and negative predictive value. Results Among the 928 patients diagnosed with severe sepsis or septic shock using the old definition, 231 (24.9%) died within 28 days. More than half of the sepsis patients (493/928, 53.1%) and more than one-third of the mortality cases (88/231, 38.1%) had a qSOFA score <2. The sensitivity of a qSOFA score ≥2 was 61.9%, which was significantly lower than the sensitivity of SIRS ≥2 (82.7%, P<0.001) and SOFA ≥2 (99.1%, P<0.001). The specificity, positive predictive value, and negative predictive value of a qSOFA score ≥2 for 28-day mortality were 58.1%, 32.9%, and 82.2%, respectively. Conclusion The current clinical criteria of the qSOFA are less sensitive than the SIRS assessment and SOFA to predict 28-day mortality in ED patients with sepsis

Experience of a Korean Disaster Medical Assistance Team in Sri Lanka after the South Asia Tsunami

On 26 December 2004, a huge tsunami struck the coasts of South Asian countries and it resulted in 29,729 deaths and 16,665 injuries in Sri Lanka. This study characterizes the epidemiology, clinical data and time course of the medical problems seen by a Korean disaster medical assistance team (DMAT) during its deployment in Sri Lanka, from 2 to 8 January 2005. The team consisting of 20 surgical and medical personnel began to provide care 7 days after tsunami in the southern part of Sri Lanka, the Matara and Hambantota districts. During this period, a total of 2,807 patients visited our field clinics with 3,186 chief complaints. Using the triage and refer system, we performed 3,231 clinical examinations and made 3,259 diagnoses. The majority of victims had medical problems (82.4%) rather than injuries (17.6%), and most conditions (92.1%) were mild enough to be discharged after simple management. There were also substantial needs of surgical managements even in the second week following the tsunami. Our study also suggests that effective triage system, self-sufficient preparedness, and close collaboration with local authorities may be the critical points for the foreign DMAT activity

Soft, curved electrode systems capable of integration on the auricle as a persistent brain–computer interface

Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain–computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain–computer interface and elicitation of an event-related potential (P300 wave)