Understanding cellular contributions to hemodynamic activity is essential for interpreting blood-based brain mapping signals. Optogenetic studies examining cell-specific influences on local hemodynamics have reported that excitatory activity results in cerebral perfusion and blood volume increase, while inhibitory activity contributes to both vasodilation and vasoconstriction. How specific subpopulations of interneurons regulate the brain’s blood supply is less examined. Parvalbumin interneurons are the largest subpopulation of GABAergic neurons in the brain, critical for brain development, plasticity, and long-distance excitatory neurotransmission. Despite their essential role in brain function, the contribution of parvalbumin neurons to neurovascular coupling has been relatively unexamined. Using optical intrinsic signal imaging and laser speckle contrast imaging, we photostimulated awake and anesthetized transgenic mice expressing channelrhodopsin under a parvalbumin promoter. Increased parvalbumin activity reduced local oxygenation, cerebral blood volume, and cerebral blood flow. These “negative” hemodynamic responses were consistent within and across mice and reproducible across a broad range of photostimulus parameters. However, the sign and magnitude of the hemodynamic response resulting from increased parvalbumin activity depended on the type and level of anesthesia used. Opposed hemodynamic responses following increased excitation or parvalbumin-based inhibition suggest unique contributions from different cell populations to neurovascular coupling.

In this study, we report that the carrier mobility of 2%-La-doped BaSnO 3 (LBSO) films on (001) SrTiO 3 and (001) MgO substrates strongly depends on the thickness whereas it is unrelated to the film/substrate lattice mismatch (+5.4 % for SrTiO 3 , −2.3 % for MgO). The films exhibited large differences in the lattice parameters, the lateral grain sizes (~85 nm for SrTiO 3 , ~20 nm for MgO), the surface morphologies, the threading dislocation densities, and the misfit dislocation densities. However, the mobility dependences on the film thickness in both cases were almost the same, saturating at ~100 cm 2 V −1 s −1 while the charge carrier densities approached the nominal carrier concentration (=[2 % La 3+ ]). Our study clearly indicates that the carrier mobility in LBSO films strongly depends on the thickness. These results would be beneficial for understanding the carrier transport properties and fruitful to further enhance the mobility of LBSO films.program funded from following programs of each country: International

Among many transition-metal oxides (TMOs), strontium cobalt oxide (SrCoO x ) is a promising active material for advanced memory devices due to the versatile valence state of cobalt ions. Several SrCoO x -based electrochemical devices have been proposed, but solid-state protonation from SrCoO 2.5 to H x SrCoO 2.5 (x = 1, 1.5, and 2) at room temperature has not been demonstrated thus far due to the absence of an appropriate solid electrolyte. Here, we demonstrate a solid-state electrochemical protonation of SrCoO 2.5 using mesoporous amorphous 12CaO• 7Al 2 O 3 (CAN) film as the solid electrolyte. The crystalline phase discretely changed from SrCoO 2.5 to HSrCoO 2.5 (phase A), H 1.5 SrCoO 2.5 (phase B), and H 2 SrCoO 2.5 (phase C) through formation of an intermediate phase of H 1.25 SrCoO 2.5 . H 1.5 SrCoO 2.5 (phase B) was colorless transparent and showed weak ferromagnetism. The present results indicate that the CAN film can be used as the solid electrolyte for the protonation treatment of TMOs.

Background Demographic, work environmental, and psychosocial features are associated with mental health of healthcare professionals at pandemic frontline. The current study aimed to find predictors of mental health for public health doctors from working experiences at frontline of COVID-19 pandemic. Methods With first-come and first-served manner, 350 public health doctors with experiences of work at COVID-19 frontline participated online survey on August 2020. Mental health was defined using the total scores of the Patient Health Questionnaire-9, the Generalized Anxiety Disorder-7, the Perceived Stress Scale, and the Stanford Presenteeism Scale-6. Multivariate logistic regression models of mental health with lowest Akaike Information Criterion were determined among all combinations of working environments, perceived threats and satisfaction at frontline, and demographics that were significant (P < 0.05) in the univariate logistic regression. Results Perceived distress, lowered self-efficacy at work, anxiety, and depressive mood were reported by 45.7, 34.6, 11.4, and 15.1% of respondents, respectively. Predictors of poor mental health found in the multivariate logistic regression analyses were environmental (insufficient personal protective equipment, workplace of screening center, prolonged workhours) and psychosocial (fear of infection and death, social stigma and rejection) aspects of working experiences at frontline. Satisfaction of monetary compensation and proactive coping (acceptance and willingness to volunteer at frontline) were predictive of better mental health. Conclusions Sufficient supply of personal protective equipment and training on infection prevention at frontline, proper workhours and satisfactory monetary compensation, and psychological supports are required for better mental health of public health doctors at frontline of COVID-19 pandemic.

Thermal transistors that electrically control heat flow have attracted growing attention as thermal management devices and phonon logic circuits. Although several thermal transistors are demonstrated, the use of liquid electrolytes may limit the application from the viewpoint of reliability or liquid leakage. Herein, a solid‐state thermal transistor that can electrochemically control the heat flow with an on‐to‐off ratio of the thermal conductivity (κ) of ≈4 without using any liquid is demonstrated. The thermal transistor is a multilayer film composed of an upper electrode, strontium cobaltite (SrCoOx), solid electrolyte, and bottom electrode. An electrochemical redox treatment at 280 °C in air repeatedly modulates the crystal structure and κ of the SrCoOx layer. The fully oxidized perovskite‐structured SrCoO3 layer shows a high κ ≈3 .8 W m−1 K−1, whereas the fully reduced defect perovskite‐structured SrCoO2 layer shows a low κ ≈ 0.95 W m−1 K−1. The present solid‐state electrochemical thermal transistor may become next‐generation devices toward future thermal management technology.

Transparent oxide semiconductors (TOSs) showing both high visible transparency andhigh electron mobility have attracted great attention towards the realization of advanced optoelectronic devices. 1-5 La-doped BaSnO 3 (LBSO) is one of the most promising TOSs because its single crystal exhibits a high electron mobility. 6-9 However, in the LBSO films, it is very hard to obtain high mobility due to the threading dislocations, which are originated from the lattice mismatch between the film and the substrate. Therefore, many researchers have tried to improve the mobility by inserting a buffer layer 6, 10-14 .While the buffer layers increased the electron mobilities, this approach leaves much to be desired since it involves a two-step film fabrication process and the enhanced mobility values are still significantly lower than single crystal values. We show herein that the electron mobility of LBSO films can be improved without inserting any buffer layers if the films are grown under highly oxidative ozone (O 3 ) atmospheres. The O 3 environments relaxed the LBSO lattice and reduced the formation of Sn 2+ states, which are known to suppress the electron mobility in LBSO. 15 The resultant O 3 -LBSO films showed improved mobility values up to 115 cm 2 V −1 s −1 , which is among the highest in LBSO films on SrTiO 3 substrates and comparable to LBSO films with buffer layers. Perovskite transparent oxide BaSnO 3 has attracted great interest since substituting La in Ba sites turns it to an n-type degenerate semiconductor with a very high electrical conductivity and electron mobility. Studies have shown that La-doped BaSnO 3 (La x Ba 1−x SnO 3, LBSO)single crystals can exhibit a high electrical conductivity (~10 4 S cm −1 ) and electron mobility (320 cm 2 V −1 s −1 ) 6, 7 with a carrier concentration of 8 × 10 19 cm −3 at room temperature (RT).Although the bandgap (E g ) of BaSnO 3 is ~3.1 eV, the E g of LBSO is ~3.5 eV due to the Burstein-Moss shift 8,9 . Since these properties are attractive for designing next generation transparent thin film electronic devices, 1, 4, 5 the electrical transport properties of thin LBSO epitaxial films have been examined many times. However, the electron mobility values in LBSO films are widely scattered from 10 to 183 cm 2 V −1 s −1 , which are much lower than the single crystal values. 6,[10][11][12][13][14] Many reports attribute the mobility suppression to the charge carrier propagation hindrance at threading dislocations or grain boundaries, which are mainly caused by the lattice mismatch at the film/substrate interface [16][17][18][19] . Therefore, many researchers inserted thick insulating buffer layers between doped BaSnO 3 film and substrate to reduce the threading dislocations. For example, A. Prakash et al. 13 optimized the thickness of buffer and La doped BSO layer and

Strontium cobalt oxide (SrCoO2.5) has recently attracted increasing attention as their optoelectronic and magnetic properties can be widely controlled using electrochemical oxidation/protonation at room temperature in air. To utilize the versatile properties of SrCoO2.5, it is essential to evaluate the location of the Fermi energy (EF) in the electronic structure, which is sensitive to the oxidation state of the Co ions. Here we show that the thermopower is an excellent measure for analyzing the EF in SrCoO2.5 epitaxial films. The lattice mismatch caused grain size reduction, which induced a slight increase in the oxidation state of the Co ions due to additional adsorbed oxygen. Although X-ray spectroscopy analyses revealed the difference of the oxidation state of the Co ions among the samples are small, an unusually large change in thermopower from +330 μV K −1 (lattice-matched) to −185 μV K −1 (lattice-mismatched) is observed from the samples due to shifts in the EF to lower energy side. The present results demonstrate the excellent sensitivity of thermopower measurement for analyzing the location of EF in the electronic structure of SrCoO2.5 in the practically usable environment.

Thermal transistors have potential as thermal management devices because they can electrically control the thermal conductivity (κ) of the active layer. Recently, we realized solid-state electrochemical thermal transistors by utilizing the electrochemical redox reaction of SrCoO y (2 ≤ y ≤ 3). However, the guiding principle to improve the on/off κ ratio has yet to be clarified because the κ modulation mechanism is unclear. This study systematically modulates κ of SrCo1–x Fe x O y (0 ≤ x ≤ 1, 2 ≤ y ≤ 3) solid solutions used as the active layers in solid-state electrochemical thermal transistors. When y = 3, the lattice κ of SrCo1–x Fe x O y is ∼2.8 W m–1 K–1 and insensitive to x. When x = 0 and y = 3, κ increases to ∼3.8 W m–1 K–1 due to the contribution of the electron κ. When y = 2, κ slightly depends on the ordered atomic arrangement. Materials that are high electrical conductors with highly ordered lattices when the transistor is on but are electrical insulators with disordered lattices when the transistor is off should be well-suited for the active layers of solid-state electrochemical thermal transistors.