Metal/graphene sheets as p-type transparent conducting electrodes in GaN light emitting diodes

We demonstrate the use of graphene based transparent sheets as a p-type current spreading layer in GaN light emitting diodes (LEDs). Very thin Ni/Au was inserted between graphene and p-type GaN to reduce contact resistance, which reduced contact resistance from similar to 5.5 to similar to 0.6 Omega/ cm(2), with no critical optical loss. As a result, LEDs with metal-graphene provided current spreading and injection into the p-type GaN layer, enabling three times enhanced electroluminescent intensity compared with those with graphene alone. We confirmed very strong blue light emission in a large area of the metal-graphene layer by analyzing image brightness.open281

Vertical transverse transport induced by hidden in-plane Berry curvature in two dimensions

The discovery of Berry curvature (BC) has spurred a tremendous surge of research into various quantum phenomena such as the anomalous transport of electrons and the topological phases of matter. In two-dimensional crystalline systems, the conventional definition of the BC lacks the in-plane components and thus it cannot explain the transverse transport along the plane-normal direction. Here, we modify the BC to provide in-plane components in two dimensions, giving rise to the vertical Hall effects that describe out-of-plane transports in response to in-plane perturbations and their Onsager reciprocity. Our first-principles calculations show that a large in-plane BC can appear even in an atomic-thick GdAg2 monolayer, and a hexagonal BiAg2 monolayer can host a large BC dipole known to vanish in the conventional BC. The quantum transports driven by the hitherto-hidden BC will become more significant in recently emerging two-dimensional platforms, including van der Waals heterostructures

Mind Bomb 1-Expressing Intermediate Progenitors Generate Notch Signaling to Maintain Radial Glial Cells

SummaryNotch signaling is critical for the stemness of radial glial cells (RGCs) during embryonic neurogenesis. Although Notch-signal-receiving events in RGCs have been well characterized, the signal-sending mechanism by the adjacent cells is poorly understood. Here, we report that conditional inactivation of mind bomb-1 (mib1), an essential component for Notch ligand endocytosis, in mice using the nestin and hGFAP promoters resulted in complete loss of Notch activation, which leads to depletion of RGCs, and premature differentiation into intermediate progenitors (IPs) and finally neurons, which were reverted by the introduction of active Notch1. Interestingly, Mib1 expression is restricted in the migrating IPs and newborn neurons, but not in RGCs. Moreover, sorted Mib1+ IPs and neurons can send the Notch signal to neighboring cells. Our results reveal that not only newborn neurons but also IPs are essential Notch-ligand-presenting cells for maintaining RGC stemness during both symmetric and asymmetric divisions

Evaluation of an immunochromatographic assay for the detection of anti-hepatitis A virus IgM

<p>Abstract</p> <p>Background</p> <p>Hepatitis A virus (HAV) is a causative agent of acute hepatitis, which is transmitted by person-to-person contact and via the faecal-oral route. Acute HAV infection is usually confirmed by anti-HAV IgM detection. In order to detect anti-HAV IgM in the serum of patients infected with HAV, we developed a rapid assay based on immunochromatography (ICA) and evaluated the sensitivity of this assay by comparing it with a commercial microparticle enzyme immunoassay (MEIA) that is widely used for serological diagnosis.</p> <p>Results</p> <p>The newly developed ICA showed 100% sensitivity and specificity when used to test 150 anti-HAV IgM-positive sera collected from infected patients and 75 negative sera from healthy subjects. Also, the sensitivity of ICA is about 10 times higher than MEIA used in this study by determining end point to detect independent on infected genotype of HAV. In addition, the ICA was able to detect 1 positive sample from among 50 sera from acute hepatitis patients that had tested negative for anti-HAV IgM using the MEIA.</p> <p>Conclusion</p> <p>Conclusively, ICA for the detection of anti-HAV IgM will be very effective for rapid assay to apply clinical diagnosis and epidemiological investigation on epidemics due to the simplicity, rapidity and specificity.</p

Air-stable n-type operation of Gd-contacted carbon nanotube field effect transistors

We report air-stable n -type operations of the single-walled carbon nanotube field effect transistors (SWNT-FETs) fabricated with Gd electrodes. Unlike previously reported n -type SWNT-FETs, our devices maintained their n -type operation characteristics in ambient atmosphere for more than two months. The shallow Gd films with a thickness below 20 nm are corroded by environmental oxygen, whereas the well-contacted Gd-SWNT interfaces underneath the thick Gd layers are protected from contaminations by air molecules. Theoretical studies based on the first-principles electronic structure calculations confirm that Gd layers have an excellent binding affinity to the SWNTs.open8

The impact of coping strategies and positive resources on post-traumatic stress symptoms among bereaved families of the Sewol ferry disaster

IntroductionThis study investigated the long-term prevalence of, and factors associated with, post-traumatic stress disorder (PTSD) among the bereaved families of the Sewol ferry disaster, in which 250 students lost their lives during a school excursion.MethodsEight years after the disaster, 181 family members were surveyed, and the prevalence of clinical PTSD symptoms was estimated. The Positive Resources Test (POREST), the Duke-UNC Functional Social Support Questionnaire, and the Brief COPE were evaluated using self-report measures. The multivariable binomial logistic regression was used to identify protective and risk factors for PTSD.ResultsPTSD symptoms were present in 49.7% of the family members 8 years after the incident. A one-point increase in the score on the optimism subscale of the POREST was associated with a 20.1% decreased likelihood of having clinical PTSD symptoms (OR = 0.799; p = 0.027; 95% CI = 0.655–0.975). Conversely, a one-point increase in the score on the avoidant subscale of Brief COPE was associated with a 13.2% increased likelihood of having clinical PTSD symptoms (OR = 1.132; p = 0.041; 95% CI = 1.005–1.274).DiscussionOur results provide evidence of the need for long-term mental health monitoring of bereaved families of disaster victims, along with valuable insights for the development of mental health intervention programs

Extracorporeal cardiopulmonary resuscitation for adult out-of-hospital cardiac arrest patients: time-dependent propensity score-sequential matching analysis from a nationwide population-based registry

Background There is inconclusive evidence regarding the effectiveness of extracorporeal cardiopulmonary resuscitation (ECPR) for out-of-hospital cardiac arrest (OHCA) patients. We aimed to evaluate the association between ECPR and neurologic recovery in OHCA patients using time-dependent propensity score matching analysis. Methods Using a nationwide OHCA registry, adult medical OHCA patients who underwent CPR at the emergency department between 2013 and 2020 were included. The primary outcome was a good neurological recovery at discharge. Time-dependent propensity score matching was used to match patients who received ECPR to those at risk for ECPR within the same time interval. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated, and stratified analysis by the timing of ECPR was also performed. Results Among 118,391 eligible patients, 484 received ECPR. After 1:4 time-dependent propensity score matching, 458 patients in the ECPR group and 1832 patients in the no ECPR group were included in the matched cohort. In the matched cohort, ECPR was not associated with good neurological recovery (10.3% in ECPR and 6.9% in no ECPR; RR [95% CI] 1.28 [0.85–1.93]). In the stratified analyses according to the timing of matching, ECPR with a pump-on within 45min after emergency department arrival was associated with favourable neurological outcomes (RR [95% CI] 2.51 [1.33–4.75] in 1–30min, 1.81 [1.11–2.93] in 31–45min, 1.07 (0.56–2.04) in 46–60min, and 0.45 (0.11–1.91) in over 60min). Conclusions ECPR itself was not associated with good neurological recovery, but early ECPR was positively associated with good neurological recovery. Research on how to perform ECPR at an early stage and clinical trials to evaluate the effect of ECPR is warranted

Positioning of the Fermi Level in Graphene Devices with Asymmetric Metal Electrodes

To elucidate the effect of the work function on the position of the Dirac point, we fabricated graphene devices with asymmetric metal contacts. By measuring the peak position of the resistance for each pair of metal electrodes, we obtained the voltage of the Dirac point VgDirac (V) from the gate response. We found that the position of VgDirac (V) in the hybrid devices was significantly influenced by the type of metal electrode. The measured shifts in VgDirac (V) were closely related to the modified work functions of the metal-graphene complexes. Within a certain bias range, the Fermi level of one of the contacts aligned with the electron band and that of the other contact aligned with the hole band