Seung‐Jun Yoo

Anosmia, the loss of smell, is a common and often the sole symptom of COVID-19. The onset of the sequence of pathobiological events leading to olfactory dysfunction remains obscure. Here, we have developed a postmortem bedside surgical procedure to harvest endoscopically samples of respiratory and olfactory mucosae and whole olfactory bulbs. Our cohort of 85 cases included COVID-19 patients who died a few days after infection with SARS-CoV-2, enabling us to catch the virus while it was still rep

The exciplex forming co‐host with phosphorescent dopant system has potential to realize highly efficient phosphorescent organic light emitting didoes (PhOLEDs). However, the exciplex forming co‐host for blue phosphorescent OLEDs has been rarely introduced because of higher triplet level of the blue dopant than green and red dopants. In this work, a novel exciplex forming co‐host with high triplet energy level is developed by mixing a phosphine oxide based electron transporting material, PO‐T2T,

A high-efficiency blue-emitting organic light-emitting diode (OLED) approaching theoretical efficiency using an exciplex-forming co-host composed of N,N'-dicarbazolyl-3,5-benzene (mCP) and bis-4,6-(3,5-di-3-pyridylphenyl)- 2-methylpyrimidine (B3PYMPM) is fabricated. Iridium(III)bis[(4,6-difluorophenyl)- pyridinato-N,C2']picolinate (FIrpic) is used as the emitter, which turns out to have a preferred horizontal dipole orientation in the emitting layer. The OLED shows a maximum external quantum eff

Bimolecular and trap‐assisted recombination mechanisms are investigated in small molecule‐based phosphorescent organic light emitting diodes (PhOLEDs) using the current−voltage−luminance characteristics in the diffusion current region, along with transient electroluminescence and capacitance measurements. Two different PhOLEDs, one with a single host, 4,4′‐Bis(carbazol‐9‐yl)biphenyl, and the other with an exciplex‐forming co‐host, are studied. Trap‐assisted recombination with a large number of t

The external quantum efficiencies (EQEs) of the fluorescent organic light-emitting diodes (OLEDs) using exciplex as emitters are much lower than fluorescent OLEDs based on single-molecular thermally activated delayed fluorescent (TADF) emitters, even though exciplex can, in principle, realize 100% internal quantum efficiency (IQE). In addition, there are no clear guidelines to improve the efficiency in exciplex-based fluorescent OLEDs. Here, we quantitatively analyze the exciton dynamics influen

A 2,7-functionalized pyrene-based emitter for highly efficient OLEDs has been developed. It offers an exceptional deep blue photoluminescence (CIE: <italic>x</italic> = 0.16, <italic>y</italic> = 0.024) and good external quantum efficiency (EQE) of 3.1% when employed in a guest–host system OLED.

elicited AMPK-dependent lipophagy, breaking down lipid droplets into free fatty acids, thereby elevating ATP in a lipid stimulus. Our findings suggest that tanycytic TSPO affects systemic energy balance through macroautophagy/autophagy-regulated lipid metabolism, and highlight the physiological significance of TSPO in hypothalamic lipid sensing and bioenergetics in response to overnutrition. ABBREVIATIONS: : oxygen consumption.

Olfactory neuropathology is a cause of olfactory loss in Alzheimer's disease (AD). Olfactory dysfunction is also associated with memory and cognitive dysfunction and is an incidental finding of AD dementia. Here we review neuropathological research on the olfactory system in AD, considering both structural and functional evidence. Experimental and clinical findings identify olfactory dysfunction as an early indicator of AD. In keeping with this, amyloid- production and neuroinflammation are rela

The use of exciplex hosts is attractive for high-performance phosphorescent organic light-emitting diodes (PhOLEDs) and thermally activated delayed fluorescence OLEDs, which have high external quantum efficiency, low driving voltage, and low efficiency roll-off. However, exciplex hosts for deep-blue OLEDs have not yet been reported because of the difficulties in identifying suitable molecules. Here, we report a deep-blue-emitting exciplex system with an exciplex energy of 3.0 eV. It is composed

In the growing field of brain-machine interface (BMI), the interface between electrodes and neural tissues plays an important role in the recording and stimulation of neural signals. To minimize tissue damage while retaining high sensitivity, a flexible and a smaller electrode with low impedance is required. However, it is a major challenge to reduce electrode size while retaining the conductive characteristics of the electrode. In addition, the mechanical mismatch between stiff electrodes and s

On Dec 1, 2020, we reported a successful case of double-lung transplantation from a SARS-CoV-2 seropositive donor 105 days after the onset of mild COVID-19.1 Although repeated quantitative (q)RT-PCR analyses of donor nasopharyngeal swabs were negative, this technique detected RNA of the SARS-CoV-2 N gene (delta Ct 35) from a biopsy of the right lung taken during organ procurement. Viral culture of this biopsy was negative and donor-to-recipient transmission did not occur. Complementary orthogona

A perfect ohmic contact is formed at the interface of indium tin oxide (ITO) and N,N'-di(naphthalene-1-yl)-N,N'-diphenyl-benzidine (NPB) using ReO3 as the interfacial layer. The hole injection efficiency is close to 100% at the interface, which is much higher than those for interfacial layers of 1,4,5,8,9,11-hexaazatripheylene hexacarbonitrile (HAT-CN) and MoO3. Interestingly, the ReO3 and MoO3 interfacial layers result in the same hole injection barrier, ≈0.4 eV, to NPB, indicating that the Fer

Can SARS-CoV-2 hitchhike on the olfactory projection and take a direct and short route from the nose into the brain? We reasoned that the neurotropic or neuroinvasive capacity of the virus, if it exists, should be most easily detectable in individuals who died in an acute phase of the infection. Here, we applied a postmortem bedside surgical procedure for the rapid procurement of tissue, blood, and cerebrospinal fluid samples from deceased COVID-19 patients infected with the Delta, Omicron BA.1,

This article reviews recent progress on charge generation by doping and its influence on the carrier mobility in organic semiconductors (OSs). The doping induced charge generation efficiency is generally low in OSs which was explained by the integer charge transfer model and the hybrid charge transfer model. The ionized dopants formed by charge transfer between hosts and dopants can act as Coulomb traps for mobile charges, and the presence of Coulomb traps in OSs broadens the density of states (