A new carbazole derivative with two carbazole moieties on the C3 and C6 positions of carbazole and triphenylsilane directly linked to the N of carbazole is successfully used as a highly efficient ...blue phosphorescent host in an organic light‐emitting diode (PhOLED). The blue PhOLED, with this new host, gives an extremely high external quantum efficiency.
Krüppel-like factor 12 (KLF12) is a transcription factor that plays a role in normal kidney development and repression of decidualization. KLF12 is frequently elevated in esophageal adenocarcinoma ...and has been reported to promote gastric cancer progression. Here, we examined the role of KLF12 in colorectal cancer (CRC). Indeed, KLF12 promotes tumor growth by directly activating early growth response protein 1 (EGR1). The levels of KLF12 and EGR1 correlate synergistically with a poor prognosis. These results indicate that KLF12 likely plays an important role in CRC and could serve as a potential prognostic marker and therapeutic target.
Gate-controlled amplifiable ultraviolet phototransistors have been demonstrated using AlGaN/GaN high-electron-mobility transistors (HEMTs) with very thin AlGaN barriers. In the AlGaN/GaN HEMTs, the ...dark current between the source and drain increases with increasing thickness of the AlGaN barrier from 10 to 30 nm owing to the increase in piezoelectric polarization-induced two-dimensional electron gas (2-DEG). However, the photocurrent of the AlGaN/GaN HEMT decreases with increasing thickness of the AlGaN barrier under ultraviolet exposure conditions. It can be observed that a thicker AlGaN barrier exhibits a much higher 2-DEG than the photogenerated carriers at the interface between AlGaN and GaN. In addition, regardless of the AlGaN barrier thickness, the source-drain dark current increases as the gate bias increases from - 1.0 to + 1.0 V. However, the photocurrent of the phototransistor with the 30 nm thick AlGaN barrier was not affected by the gate bias, whereas that of the phototransistor with 10 nm thick AlGaN barrier was amplified from reduction of the gate bias. From these results, we suggest that by controlling the gate bias, a thin AlGaN barrier can amplify/attenuate the photocurrent of the AlGaN/GaN HEMT-based phototransistor.
Soluble forms of receptors play distinctive roles in modulating signal-transduction pathways. Soluble CD74 (sCD74) has been identified in sera of inflammatory diseases and implicated in their ...pathophysiology; however, few relevant data are available in the context of cancer. Here we assessed the composition and production mechanisms, as well as the clinical significance and biological properties, of sCD74 in melanoma. Serum sCD74 levels were significantly elevated in advanced melanoma patients compared with normal healthy donors, and the high ratio of sCD74 to macrophage-migration inhibitory factor (MIF) conferred significant predictive value for prolonged survival in these patients (p = 0.0035). Secretion of sCD74 was observed primarily in melanoma cell lines as well as a THP-1 line of macrophages from monocytes and primary macrophages, especially in response to interferon-γ (IFN-γ). A predominant form that showed clinical relevance was the 25-KDa sCD74, which originated from the 33-KDa isoform of CD74. The release of this sCD74 was regulated by either a disintegrin and metalloproteinase-mediated cell-surface cleavage or cysteine-protease-mediated lysosomal cleavage, depending on cell types. Both recombinant and THP-1 macrophage-released endogenous sCD74 suppressed melanoma cell growth and induced apoptosis under IFN-γ stimulatory conditions via inhibiting the MIF/CD74/AKT-survival pathway. Our findings demonstrate that the interplay between sCD74 and MIF regulates tumor progression and determines patient outcomes in advanced melanoma.
Graphene produced by chemical vapor deposition (CVD) has attracted great interest as a transparent conducting material, due to its extraordinary characteristics such as flexibility, optical ...transparency, and high conductivity, especially in next‐generation displays. Graphene‐based novel electrodes have the potential to satisfy the important factors for high‐performance flexible organic light‐emitting diodes (OLEDs) in terms of sheet resistance, transmittance, work function, and surface roughness. In this study, flexible and transparent graphene electrode architecture is proposed by adopting a selective defect healing technique for CVD‐grown graphene, which results in several benefits that produce high‐performance devices with excellent stabilities. The proposed architecture, which has a multi‐layer graphene structure treated by a layer‐by‐layer healing process, exhibits significant improvement in sheet resistance with high optical transparency. For improving the charge transport property and mechanical robustness, various defect sites of the CVD‐grown graphene are successfully decorated with gold nanoparticles through a simple electroplating (EP) method. Further, a graphene‐based OLED device that integrates the proposed electrode architecture on flexible substrates is demonstrated. Therefore, this architecture provides a new strategy to fabricate graphene electrode in OLEDs, extending graphene's immense potential as an advanced conductor toward high‐performance, flexible, and transparent displays.
Flexible and transparent graphene electrode architecture with layer‐by‐layer defect healing is proposed for the high‐performance graphene‐based flexible organic light‐emitting diodes. Improved performance including excellent charge transport and mechanical robustness of the proposed electrode architecture is systemically investigated, showing synergetic effects of selective defect healing and structural advantages. The new graphene electrode architecture demonstrates the great possibilities for flexible and transparent graphene‐based displays.
To address the increasing demand for multicolor light-emitting diodes (LEDs), a monolithic multicolor LED with a simple process and high reliability is desirable. In this study, organic–inorganic ...hybrid LEDs with violet and green wavelengths were fabricated by depositing CsPbBr3 perovskite green quantum dots (QDs) as the light-converting material on InGaN-based violet LEDs. As the injection current was increased, the total electroluminescence (EL) intensities of the hybrid LEDs increased, whereas the light-converted green emission efficiency of the CsPbBr3 QDs decreased. The maximum green-to-violet EL spectral intensity ratio of the hybrid LEDs with CsPbBr3 QDs was achieved with the injection current of <10 mA. Moreover, the EL spectral ratio of the green-to-violet emission decreased at an injection current of 100 mA. The light-conversion intensity of the CsPbBr3 QDs decreased linearly as the junction temperature of the hybrid LEDs was increased with increasing injection current, similar to the temperature-dependent photoluminescence degradation of CsPbBr3 QDs. In addition, the junction temperature of the hybrid LED was minimized by pulse injection to suppress the thermal degradation of QDs and increase the light conversion efficiency to green emission. Therefore, the overall emission spectrum color coordinates of the hybrid LEDs exhibited a red shift from violet to blue in the low-current region and a blue shift toward violet as the green emission of the QDs was decreased above 10 mA.
The manipulation of radiative properties of light emitters coupled with surface plasmons is important for engineering new nanoscale optoelectronic devices, including lasers, detectors and single ...photon emitters. However, so far the radiative rates of excited states in semiconductors and molecular systems have been enhanced only moderately, typically by a factor of 10-50, producing emission mostly from thermalized excitons. Here, we show the generation of dominant hot-exciton emission, that is, luminescence from non-thermalized excitons that are enhanced by the highly concentrated electromagnetic fields supported by the resonant whispering-gallery plasmonic nanocavities of CdS-SiO(2)-Ag core-shell nanowire devices. By tuning the plasmonic cavity size to match the whispering-gallery resonances, an almost complete transition from thermalized exciton to hot-exciton emission can be achieved, which reflects exceptionally high radiative rate enhancement of >10(3) and sub-picosecond lifetimes. Core-shell plasmonic nanowires are an ideal test bed for studying and controlling strong plasmon-exciton interaction at the nanoscale and opens new avenues for applications in ultrafast nanophotonic devices.
Imperfection originating from the ionic nature of organic inorganic hybrid perovskite (OIHP) is a major factor that degrades perovskite solar cells (PSCs) performance, and mitigating or removing it ...is essential for the implementation of high-performance PSCs. In this work, 2-hydroxyethyl acrylate (HEA), having both effective CO and O–H functional groups, is introduced as a functional additive that suppress imperfections by to control the crystallization process and passivate them at the same time, and the role of each function groups have been systematically investigated. We have found that O–H functional groups of HEA strongly interacts with organic cations (i.e., MABr, FAI) to form more stable organic cation-HEA complex selectively, delaying the crystallization process of perovskite. As a result, HEA improves crystallinity and grain size of perovskite and reduces charge trapping density by passivation and/or suppression of defect states. HEA raises average cell-efficiency from 17.37% to 19.01% and the maximum efficiency is reached to 21.01% for the inverted planar PSC. In addition, large-area (1.08 cm2) PSCs show an excellent efficiency of 20.40%, which is the highest efficiency in large-area inverted planar PSCs to date. PSCs with HEA also show long-term stability and better moisture resistance capabilities in ambient air conditions.
Display omitted
•2-hydroxyethyl acrylate (HEA) was introduced as a functional additive to suppress imperfections of perovskite.•HEA has formed more stable organic cation-HEA complex selectively.•HEA improves crystallinity and grain size of perovskite by delaying the crystallization process of perovskite.•HEA reduces charge trapping density by passivation and/or suppression of defect states.•Large-area PSCs with HEA achieved an excellent efficacy of 20.40%.
Abstract
Objective
Tinnitus is a common symptom of idiopathic sudden sensorineural hearing loss (ISSHL). This study aimed to investigate the characteristics and outcomes of acute tinnitus in patients ...with ISSHL.
Methods
A total of 59 patients with ISSHL and acute tinnitus were enrolled. All patients underwent audiological assessment, tinnitus matching for loudness and frequency, and steroid treatment for sudden hearing loss. Tinnitus‐related distress was assessed using the tinnitus handicap inventory (THI) questionnaire. The outcomes of hearing recovery and tinnitus remission were investigated retrospectively.
Results
The loudness and pitch of acute tinnitus were 63.2 ± 22.4 dB HL and 2010.63 ± 2368.99 Hz, respectively. Complete and partial recovery rates of acute tinnitus in ISSHL patients were 32.2% and 39% according to the THI scores. The group with complete recovery of hearing showed significantly greater improvement in tinnitus distress than the group with no improvement in hearing. The loudness and pitch of tinnitus did not correlate with tinnitus remission.
Conclusion
Hearing recovery is more important for tinnitus remission than the psychoacoustic characteristics of acute tinnitus. Timely identification and proper treatment of hearing loss are important to improve tinnitus remission in patients with ISSHL.
Level of Evidence
Level 4.
To document the experiences of converting a general hospital to a coronavirus disease 2019 (COVID-19) designated hospital during an outbreak in Daegu, Republic of Korea.
The hospital management ...formed an emergency task force team, whose role was to organize the COVID-19 hospital. The task force used different collaborative channels to redistribute resources and expertise to the hospital. Leading doctors from the departments of infectious diseases, critical care and pulmonology developed standardized guidelines for treatment coherence. Nurses from the infection control team provided regular training on donning and doffing of personal protective equipment and basic safety measures.
Keimyung University Daegu Dongsan hospital became a red zone hospital for COVID-19 patients on 21 February 2020. As of 29 June 2020, 1048 COVID-19 patients had been admitted to the hospital, of which 22 patients died and five patients were still being treated in the recovery ward. A total of 906 health-care personnel worked in the designated hospital, of whom 402 were regular hospital staff and 504 were dispatched health-care workers. Of these health-care workers, only one dispatched nurse acquired COVID-19. On June 15, the hospital management and Daegu city government decided to reconvert the main building to a general hospital for non-COVID-19 patients, while keeping the additional negative pressure rooms available, in case of resurgence of the disease.
Centralized coordination in frontline hospital operation, staff management, and patient treatment and placement allowed for successful pooling and utilization of medical resources and manpower during the COVID-19 outbreak.
PDF
