Deposition-Temperature Dependence of Vortex Pinning Property in YBa2Cu3O7+BaHfO3 Films

Improvement of critical current density (Jc) in magnetic fields is required in YBa2Cu3O7 films, and process parameters should be optimized for controlling pinning centers. In the present study, a deposition temperature was varied in pulsed laser deposition of YBa2Cu3O7+BaHfO3 films to control the nanorod structure, and its influence on Jc was analyzed. The YBa2Cu3O7+BaHfO3 film deposited at 850°C exhibited pinning force maximum (Fp,max) as high as 413 GN/m3 at 40 K, while the Fp,max for the deposition temperature of 850°C at 77 K was smaller than that in the YBa2Cu3O7+BaHfO3 film deposited at 900°C. A critical temperature decreased and matching field increased with decreasing the deposition temperature. Increase in deposition temperature is effective in improving the Fp,max in high temperatures, since the critical temperature and matching field dependences of Jc value dominate the Fp,max. On the other hand, low deposition temperature improves the Fp,max in low temperatures since the Fp shift in accordance with matching field is dominant to the Fp,max. Thus, the deposition temperature should be set in pulsed laser deposition of YBa2Cu3O7 films containing nanorods considering the Jc variation with critical temperature and matching field

Influence of matching field on critical current density and irreversibility temperature in YBa2Cu3O7 films with BaMO3(M=Zr, Sn, Hf) nanorods

The influence of the matching field (BΦ) on critical current density (Jc) and irreversibility temperature (Tirr) in YBa2 Cu3O7 films containing BaMO3 (M=Zr, Sn, Hf) nanorods was investigated. It was revealed that the irreversibility temperature normalized by the critical temperature (Tirr/Tc) was influenced by BΦ, for B>BΦ, but Tirr/Tc did not depend on which BaMO3 material was used for B<BΦ, i.e., there was no dependence on nanorod density, diameter, interface sharpness, or Tc in the case of ideal nanorods. However, Jc/Jc(0 T) was found to decrease with increasing BΦ at low magnetic field strengths and to improve at high magnetic field strengths. In addition to Jc being dependent on BΦ, the Tc term in Tirr and Jc(0 T) were also found to have an effect on Jc

Control of the glass-liquid transition temperature in YBa2Cu3O7-x films

Magnetic field dependences of the glass-liquid transition temperature (Tg) were studied in YBa2Cu3O7−x films containing various types of nanoinclusions. The vortex configuration entangled or straight and pinning strength for each vortex are crucial to the behaviors of Tg. c-axis correlated pinning centers optimize these factors and achieve the upper limit of Tg, which is determined by loss of line tension of vortices, if they are elongated through a thickness of a sample. By optimizing pinning centers, critical temperature, and a matching field, a Tg value of 77 K can be obtained in YBa2Cu3O7−x in a magnetic field as high as 27 T

Training Attention to the Other’s Need Improves Helping Behaviors in Children with Autism Spectrum Disorder: A Behavioral Analysis Using a Two-dimensional Motion Capture System

While children with autism spectrum disorder (ASD) can acquire helping behaviors through appropriate interventions, changes in behaviors prior to helping (pre-helping behaviors) remain unclear. In the present study, we examined the effects of social skills training (SST) on helping and pre-helping behaviors in two children with ASD by using a two-dimensional motion capture system. During the SST, the children learned one helping behavior that they lent their items to their partners, and we measured their head movements before initiating the helping behavior (i.e., pre-helping behavior). As a result of SST, the participants became able to help others in response to less-explicit social stimuli after the intervention. Regarding pre-helping behaviors, the children with ASD before the intervention looked straight at the helpee (i.e., recipient of the help) more often than did typically developing peers, and such a behavior was shown to increase after SST. These results indicate that although spontaneous attention to social stimuli may be reduced in children with ASD, success in attending to a helpee could lead to the emergence of helping behaviors. Moreover, the changes in pre-helping behavior indicate an increase in children’s attention to the helpee after the intervention, which may have enhanced their sensitivity to persons in need

Pin potential effect on vortex pinning in YBa2Cu3O7-δ films containing nanorods: Pin size effect and mixed pinning

The pin size effect and mixed pinning of nanorods and matrix defects are discussed for YBa2Cu3O7-δ films containing nanorods. BaSnO3 nanorods with a diameter of 11 nm and BaHfO3 nanorods with a diameter of 7 nm were prepared, and critical current density (Jc) and resistivity were measured in the films. When the coherence length was larger than the nanorod size at high temperatures near the critical temperature, the trapping angle and activation energy of the vortex flow depended on the nanorod diameter. At a moderate temperature of 65-77K, the pin size effect on Jc disappeared since the coherence length became smaller than the nanorod size. At a low temperature of 20K, the contribution from matrix pinning became comparable to that of nanorods in a high magnetic field due to the small coherence length. Thus, the temperature-dependent coherence length caused the pin potential situation to vary significantly, namely, the pin size effect and mixed pinning, which strongly affected vortex pinning in YBa2Cu3O7-d containing nanorods

Nanostructures and flux pinning properties in YBa2Cu3O7−y thin films with double perovskite Ba2LuNbO6 nanorods

Double perovskite Ba2LuNbO6 (BLNO)-doped YBa2Cu3O7−y (YBCO) thin films are fabricated on a SrTiO3 (001) substrate by pulsed laser deposition, and their nanostructures are characterized by transmission electron microscopy and scanning transmission electron microscopy. Cross-sectional observations and elemental mapping reveal that BLNO self-assembles during thin film deposition, and consequently, nanorods extending straight from the substrate to the surface are formed in the YBCO thin films. It is confirmed that stacking faults perpendicular to the growth direction disturb the formation of BLNO nanorods. Strain maps extracted by geometric phase analysis reveal that the tensile strain occurs in the YBCO matrix around the BLNO nanorods. Misfit dislocations are periodically introduced at the interface between the nanorod and the matrix, which results in the inhomogeneous strain of YBCO around the BLNO nanorods. The superconducting properties of the YBCO + BLNO thin films are compared with those of other previously reported YBCO thin films with normal perovskite and double perovskite nanorods

The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

DOCK2 is involved in the host genetics and biology of severe COVID-19

「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target