Proton-transfer-induced 3D/2D hybrid perovskites suppress ion migration and reduce luminance overshoot

Abstract: Perovskite light-emitting diodes (PeLEDs) based on three-dimensional (3D) polycrystalline perovskites suffer from ion migration, which causes overshoot of luminance over time during operation and reduces its operational lifetime. Here, we demonstrate 3D/2D hybrid PeLEDs with extremely reduced luminance overshoot and 21 times longer operational lifetime than 3D PeLEDs. The luminance overshoot ratio of 3D/2D hybrid PeLED is only 7.4% which is greatly lower than that of 3D PeLED (150.4%). The 3D/2D hybrid perovskite is obtained by adding a small amount of neutral benzylamine to methylammonium lead bromide, which induces a proton transfer from methylammonium to benzylamine and enables crystallization of 2D perovskite without destroying the 3D phase. Benzylammonium in the perovskite lattice suppresses formation of deep-trap states and ion migration, thereby enhances both operating stability and luminous efficiency based on its retardation effect in reorientation

True image construction in quantum-secured single-pixel imaging under spoofing attack

In this paper, we introduce a quantum-secured single-pixel imaging technique designed to withstand spoofing attacks, wherein adversaries attempt to deceive imaging systems with fake signals. Unlike previous quantum-secured protocols that impose a threshold error rate limiting their operation, even with the existence of true signals, our approach not only identifies spoofing attacks but also facilitates the reconstruction of a true image. Our method involves the analysis of a specific mode correlation of a photon-pair, which is independent of the mode used for image construction, to check security. Through this analysis, we can identify both the targeted image region of the attack and the type of spoofing attack, enabling reconstruction of the true image. A proof-of-principle demonstration employing the polarization-correlation of a photon-pair is provided, showcasing successful image reconstruction even under the condition of spoofing signals that are 2000 times stronger than true signals. We expect our approach to be applied to quantum-secured signal processing, such as quantum target detection or ranging

The mechanism of hot ductility loss and recovery in Nb-bearing low alloy steels

In low alloy steels containing Nb, the poor hot ductility is basically due to the austenite grain boundary segregation of sulfur and the additional matrix strengthening of Nb(C,N) precipitates, both of which decrease the equicohesive temperature. The recovery of hot ductility is therefore attributed to not only the clean grain boundaries that the segregated sulfur is scavenged through the MnS reaction but also the matrix softening by the coarse Nb(C,N) precipitates.X1144sciescopu

Correlation Between MnS Precipitation, Sulfur Segregation Kinetics, and Hot Ductility in C-Mn Steel

In a C-Mn steel without Nb, the mechanism of hot ductility loss and recovery has been understood. The specimens were solution treated at 1673 K (1400 °C), subsequently cooled to 1273 K (1000 °C) at a rate of 1 or 20 K/s and finally held at the temperature. At a rate of 1 K/s, the segregation concentration of sulfur at prior austenite grain boundaries decreases gradually with holding time. At the rate of 20 K/s, the segregation concentration of sulfur shows a convex profile in a time versus segregation concentration plot. Such segregation behaviors of sulfur are deeply related to the MnS reaction during cooling to 1273 K (1000 °C) or holding at the temperature. The high-temperature intergranular fracture observed in this steel is due to the sulfur segregated at the grain boundaries. The recovery of hot ductility results from the combination between the decrease in sulfur segregation concentration governed by the MnS reaction and the overall decohesion at the interface of the MnS particles which act as a strong sink of the free sulfur tending to segregate to the grain boundaries.X1173Nsciescopu

Neuron-specific enolase level as a predictor of neurological outcome in near-hanging patients: A retrospective multicenter study.

ObjectivesNeuron-specific enolase (NSE) is frequently used to predict neurological outcomes in patients with hypoxic brain injury. Hanging can cause hypoxic brain damage, and survivors can suffer from neurological deficits that may impair daily activities. Here, we investigated the utility of the initial serum NSE level as a predictor of neurological outcomes in near-hanging patients with decreased consciousness.MethodsThis retrospective multicenter study was conducted in patients who visited the emergency department due to near-hanging injury from October 2013 to February 2019 at three university hospitals in Korea. They were divided into two groups according to the presence of out-of-hospital cardiac arrest. The neurological outcome was determined using the Cerebral Performance Category (CPC) measured at the time of discharge. Multivariate analysis was performed to determine whether initial serum NSE is an independent predictor of neurological outcome.ResultsOf the 70 patients included in the study, 44 showed a poor neurological outcome (CPC score = 3-5). Among the 52 patients with cardiac arrest, only 10 (19.2%) were discharged with good neurological outcome (CPC score = 1-2). In the whole cohort, a high serum NSE level was a significant predictor of poor neurological outcome (odds ratio [OR], 1.343; 95% confidence interval [CI], 1.003-1.800, p = 0.048). Among the patients with cardiac arrest, a high serum NSE level was a significant predictor of poor neurological outcome (OR, 1.138; 95% CI, 1.009-1.284, p = 0.036).ConclusionsIn near-hanging patients, a high initial serum NSE level is an independent predictor of poor neurological outcome

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Characteristics of the study population according to NAFLD severity.

Characteristics of the study population according to NAFLD severity.</p

sUA AUC, cut-off value, sensitivity, specificity.

BackgroundWith the prevalence of non-alcoholic fatty liver disease (NAFLD) increasing worldwide, many noninvasive techniques have been used to improve its diagnosis. Recently, the serum uric acid/creatinine (sUA/sCr) ratio was identified as an indicator of fatty liver disease. Therefore, we examined the relationship between sUA/sCr levels and ultrasound-diagnosed NAFLD in Korean adults.MethodsThis study included 16,666 20-year-olds or older who received health checkups at a university hospital’s health promotion center from January to December 2021. Among them, 11,791 non-patients with and without NAFLD were analyzed, excluding those without abdominal ultrasound, those without data on fatty liver, cancer, or chronic kidney disease severity, those with a history of alcohol abuse, and those with serum hs-CRP ResultssUA/sCr increased with fatty liver severity, and the post-correction OR in the NAFLD group was 1.183 (95% CI: 1.137–1.231) compared to the group without NAFLD. Concerning the fatty liver severity, the post-correction OR in the mild NAFLD group increased to 1.147 (95% CI: 1.099–1.196), and that in the moderate-to-severe NAFLD group increased to 1.275 (95% CI: 1.212–1.341) compared to the group without NAFLD. The sensitivity of sUA/sCr to fatty liver severity was 57.9% for the non-NAFLD group, 56.7% for the mild NAFLD group, and 59.0% for the moderate-to-severe NAFLD group; the specificity of sUA/sCr to fatty liver severity 61.4% for the non-NAFLD group, 57.3% for the mild NAFLD group, and 65.2% for the moderate-to-severe NAFLD group.ConclusionNAFLD severity is associated with sUA/sCR.</div