Reversibly controlled ternary polar states and ferroelectric bias promoted by boosting square???tensile???strain

Interaction between dipoles often emerges intriguing physical phenomena, such as exchange bias in the magnetic heterostructures and magnetoelectric effect in multiferroics, which lead to advances in multifunctional heterostructures. However, the defect-dipole tends to be considered the undesired to deteriorate the electronic functionality. Here, we report deterministic switching between the ferroelectric and the pinched states by exploiting a new substrate of cubic perovskite, BaZrO3, which boosts square-tensile-strain to BaTiO3 and promotes four-variants in-plane spontaneous polarization with oxygen vacancy creation. First-principles calculations propose a complex of an oxygen vacancy and two Ti3+ ions coins a charge-neutral defect-dipole. Cooperative control of the defect-dipole and the spontaneous polarization reveals ternary in-plane polar states characterized by biased/pinched hysteresis loops. Furthermore, we experimentally demonstrate that three electrically controlled polar-ordering states lead to switchable and non-volatile dielectric states for application of non-destructive electro-dielectric memory. This discovery opens a new route to develop functional materials via manipulating defect-dipoles and offers a novel platform to advance heteroepitaxy beyond the prevalent perovskite substrates

Effects of Simultaneous Cognitive Task on Gait Event Accuracy with Auditory Stimuli: Comparison between Young Adults in Their 20s and the Elderly in their 70s

The purpose of this study was to compare the difference in the accuracy of gait events between young and older adults during metronomic walking by auditory cueing. Additionally, age-specific changes in the gait event accuracy according to additional simultaneous cognitive tasks were examined. The time interval (or temporal error) between the auditory cue (i.e., metronome) and the heel contact was used as the accuracy of the gait event. Fifteen young group (YG, 24.7 ± 0.8 years) and 14 elderly (EG, 78.4 ± 5.5 years) people participated in the experiment. The temporal errors under two gait conditions (MET: walking with metronome; MET + BC: walking with metronome while counting backward) were compared for each group. The results revealed that all the temporal errors of EG were significantly greater than those of YG. While the addition of simultaneous cognitive tasks resulted in a significant increase in temporal error in both age groups, the coefficient of variation (CV) of the temporal error significantly increased only in the EG group. In other words, although heel contact accuracy with auditory stimuli was affected by the simultaneous cognitive task in both groups, it was demonstrated that the variability of the error in the young adults remained constant. Therefore, the time error measurement used in this study has the potential to be used as a tool to judge the gait instability of the elderly compared with young adults

Effects of Simultaneous Cognitive Task on Gait Event Accuracy with Auditory Stimuli: Comparison between Young Adults in Their 20s and the Elderly in their 70s

The purpose of this study was to compare the difference in the accuracy of gait events between young and older adults during metronomic walking by auditory cueing. Additionally, age-specific changes in the gait event accuracy according to additional simultaneous cognitive tasks were examined. The time interval (or temporal error) between the auditory cue (i.e., metronome) and the heel contact was used as the accuracy of the gait event. Fifteen young group (YG, 24.7 ± 0.8 years) and 14 elderly (EG, 78.4 ± 5.5 years) people participated in the experiment. The temporal errors under two gait conditions (MET: walking with metronome; MET + BC: walking with metronome while counting backward) were compared for each group. The results revealed that all the temporal errors of EG were significantly greater than those of YG. While the addition of simultaneous cognitive tasks resulted in a significant increase in temporal error in both age groups, the coefficient of variation (CV) of the temporal error significantly increased only in the EG group. In other words, although heel contact accuracy with auditory stimuli was affected by the simultaneous cognitive task in both groups, it was demonstrated that the variability of the error in the young adults remained constant. Therefore, the time error measurement used in this study has the potential to be used as a tool to judge the gait instability of the elderly compared with young adults

Developmental expression of transferrin binding protein in oligodendrocyte lineage cells of the embryonic chick spinal cord

Oligodendrocytes develop from precursor cells in the neuroepithelium of the ventral ventricular zone. Oligodendrocytes in the different stages of development are characterized by expression of a number of different marker molecules such as myelin genes, growth factors, and specific antigens. We have previously identified that transferrin binding protein (TfBP), a member of heat shock protein 90 families, is a novel avian ER-associated membrane protein that is specifically localized in oligodendrocytes in adult chicken CNS. In this study we describe the developmental expression of TfBP in the embryonic chick spinal cord. A few, distinct, TfBP+ cells appeared at the lateral margin of the subventricular neuroepithelium of the spinal cord at E7. Thereafter, some TfBP+ cells, exhibited a migrative form of unipolar or bipolar shape occurred around E8 in the mantle layer, midway between the neuroepithelium and the marginal layer of the primitive spinal cord. Thereafter, the TfBP+ cells rapidly increased in number as well as their staining intensity, and overall distribution of TfBP+ cells at E15 was comparable to that of a mature spinal cord. Our observations suggest that TfBP is expressed in the subpopulation of oligodendrocyte lineage in the development and a putative role of TfBP in relation to transferrin and iron trafficking is considered

Development of Poly(2-Methacryloyloxyethyl Phosphorylcholine)-Functionalized Hydrogels for Reducing Protein and Bacterial Adsorption

A series of hydrogels with intrinsic antifouling properties was prepared via surface-functionalization of poly(2-hydroxyethyl methacrylate) [p(HEMA)]-based hydrogels with the biomembrane-mimicking zwitterionic polymer, poly(2-methacryloyloxyethyl phosphorylcholine) [p(MPC)]. The p(MPC)-modified hydrogels have enhanced surface wettability, high water content retention (61.0%–68.3%), and good transmittance (>90%). Notably, the presence of zwitterionic MPC moieties at the hydrogel surfaces lowered the adsorption of proteins such as lysozyme and bovine serum albumin (BSA) by 73%–74% and 59%–66%, respectively, and reduced bacterial adsorption by approximately 10%–73% relative to the unmodified control. The anti-biofouling properties of the p(MPC)-functionalized hydrogels are largely attributed to the dense hydration layer formed at the hydrogel surfaces by the zwitterionic moieties. Overall, the results demonstrate that biocompatible and antifouling hydrogels based on p(HEMA)-p(MPC) structures have promising potential for application in biomedical materials

Astrocytic expressions of phosphorylated Akt, GSK3beta and CREB following an excitotoxic lesion in the mouse hippocampus

Glycogen synthase kinase 3beta (GSK3beta) is believed to play important roles in the regulation of synaptic plasticity, cell survival and circadian rhythms in the mature CNS. However, although several studies have been focused on the GSK3beta, little is known about GSK3beta changes in glial cells under neuropathological conditions. In this study, we evaluated the expressions of molecules associated with the GSK3beta signaling pathway, following the induction of an excitotoxic lesion in mouse brain by kainic acid (KA) injection, which caused pyramidal cell degeneration in the hippocampal CA3 region. In injured hippocampi, Ser47-Akt (protein kinase B, PKB) phosphorylation increased from 4 h until 1 day post-injection (PI). Ser9-GSK3beta and Ser133-cAMP responsive element-binding protein (CREB) phosphorylations showed similar spatiotemporal patterns in hippocampi at 1 day until 3 days PI. Double immunohistochemistry also showed that these phosphorylated forms of Akt, GSK3beta and CREB were expressed in astrocytes. For the first time, our data demonstrate the injury-induced astrocytic changes in the levels of phosphorylation of Akt, -GSK3beta and -CREB in vivo, which may reflect mechanisms of glial cells protection or adaptive response to damage