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Vertical charge order shapes the electronic properties in layered charge density wave (CDW) materials. Various stacking orders inevitably create nanoscale domains with distinct electronic structures inaccessible to bulk probes. Here, the stacking characteristics of bulk 1T-TaS 2 are analyzed using scanning tunneling spectroscopy (STS) and density functional theory (DFT) calculations. It is observed that Mott-insulating domains undergo a transition to band-insulating domains restoring vertical dimerization of the CDWs. Furthermore, STS measurements covering a wide terrace reveal two distinct band insulating domains differentiated by band edge broadening. These DFT calculations reveal that the Mott insulating layers preferably reside on the subsurface, forming broader band edges in the neighboring band insulating layers. Ultimately, buried Mott insulating layers believed to harbor the quantum spin liquid phase are identified. These results resolve persistent issues regarding vertical charge order in 1T-TaS 2 , providing a new perspective for investigating emergent quantum phenomena in layered CDW materials., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

In this study, we investigate the coexistence of short- and long-term memory effects owing to the programmable retention characteristics of a two-dimensional Au/MoS 2 /Au atomristor device and determine the impact of these effects on synaptic properties. This device is constructed using bilayer MoS 2 in a crossbar structure. The presence of both short- and long-term memory characteristics is proposed by using a filament model within the bilayer transition-metal dichalcogenide. Short- and long-term properties are validated based on programmable multilevel retention tests. Moreover, we confirm various synaptic characteristics of the device, demonstrating its potential use as a synaptic device in a neuromorphic system. Excitatory postsynaptic current, paired-pulse facilitation, spike-rate-dependent plasticity, and spike-number-dependent plasticity synaptic applications are implemented by operating the device at a low-conductance level. Furthermore, long-term potentiation and depression exhibit symmetrical properties at high-conductance levels. Synaptic learning and forgetting characteristics are emulated using programmable retention properties and composite synaptic plasticity. The learning process of artificial neural networks is used to achieve high pattern recognition accuracy, thereby demonstrating the suitability of the use of the device in a neuromorphic system. Finally, the device is used as a physical reservoir with time-dependent inputs to realize reservoir computing by using short-term memory properties. Our study reveals that the proposed device can be applied in artificial intelligence-based computing applications by utilizing its programmable retention properties.

In addition to cellular damage, ischemia-reperfusion (IR) injury induces substantial damage to the mitochondria and endoplasmic reticulum. In this study, we sought to determine whether impaired mitochondrial function owing to IR could be restored by transplanting mitochondria into the heart under ex vivo IR states. Additionally, we aimed to provide preliminary results to inform therapeutic options for ischemic heart disease (IHD). Healthy mitochondria isolated from autologous gluteus maximus muscle were transplanted into the hearts of Sprague-Dawley rats damaged by IR using the Langendorff system, and the heart rate and oxygen consumption capacity of the mitochondria were measured to confirm whether heart function was restored. In addition, relative expression levels were measured to identify the genes related to IR injury. Mitochondrial oxygen consumption capacity was found to be lower in the IR group than in the group that underwent mitochondrial transplantation after IR injury (p < 0.05), and the control group showed a tendency toward increased oxygen consumption capacity compared with the IR group. Among the genes related to fatty acid metabolism, Cpt1b (p < 0.05) and Fads1 (p < 0.01) showed significant expression in the following order: IR group, IR + transplantation group, and control group. These results suggest that mitochondrial transplantation protects the heart from IR damage and may be feasible as a therapeutic option for IHD.

Alzheimer's disease (AD) and its related age at onset (AAO) are highly heterogeneous, due to the inherent complexity of the disease. They are affected by multiple factors, such as neuroimaging and genetic predisposition. Multimodal integration of various data types is necessary; however, it has been nontrivial due to the high dimensionality of each modality. We aimed to identify multimodal biomarkers of AAO in AD using an extended version of sparse canonical correlation analysis, in which we integrated two imaging modalities, functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), and genetic data in the form of single-nucleotide polymorphisms (SNPs) obtained from the Alzheimer's disease neuroimaging initiative database. These three modalities cover low-to-high-level complementary information and offer multiscale insights into the AAO. We identified multivariate markers of AAO in AD using fMRI, PET, and SNP. Furthermore, the markers identified were largely consistent with those reported in the existing literature. In particular, our serial mediation analysis suggests that genetic variants influence the AAO in AD by indirectly affecting brain connectivity by mediation of amyloid-beta protein accumulation, supporting a plausible path in existing research. Our approach provides comprehensive biomarkers related to AAO in AD and offers novel multimodal insights into AD., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The bipolar resistive switching properties of Pt/TaO x /InO x /ITO-resistive random-access memory devices under DC and pulse measurement conditions are explored in this work. Transmission electron microscopy and X-ray photoelectron spectroscopy were used to confirm the structure and chemical compositions of the devices. A unique two-step forming process referred to as the double-forming phenomenon and self-compliance characteristics are demonstrated under a DC sweep. A model based on oxygen vacancy migration is proposed to explain its conduction mechanism. Varying reset voltages and compliance currents were applied to evaluate multilevel cell characteristics. Furthermore, pulses were applied to the devices to demonstrate the neuromorphic system's application via testing potentiation, depression, spike-timing-dependent plasticity, and spike-rate-dependent plasticity.

RRAM devices operating based on the creation of conductive filaments via the migration of oxygen vacancies are widely studied as promising candidates for next-generation memory devices due to their superior memory characteristics. However, the issues of variation in the resistance state and operating voltage remain key issues that must be addressed. In this study, we propose a TaO x /SiO 2 bilayer device, where the inserted SiO 2 layer localizes the conductive path, improving uniformity during cycle-to-cycle endurance and retention. Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) confirm the device structure and chemical properties. In addition, various electric pulses are used to investigate the neuromorphic system properties of the device, revealing its good potential for future memory device applications.

In this paper, we fabricate an ITO/SiN/TaN memristor device and analyze its electrical characteristics for a neuromorphic system. The device structure and chemical properties are investigated using transmission electron microscopy and X-ray photoelectron spectroscopy. Uniform bipolar switching is achieved through DC sweep under a compliance current of 5 mA. Also, the analog reset phenomenon is observed by modulating the reset voltage for long-term memory. Additionally, short-term memory characteristics are obtained by controlling the strength of the pulse response. Finally, bio-inspired synaptic characteristics are emulated using Hebbian learning rules such as spike-rate-dependent plasticity (SRDP) and spike-timing-dependent plasticity (STDP). As a result, we believe that the coexistence of short-term and long-term memories in the ITO/SiN/TaN device can provide flexibility in device design in future neuromorphic applications.

Although vertical configurations for high-density storage require challenging process steps, such as etching high aspect ratios and atomic layer deposition (ALD), they are more affordable with a relatively simple lithography process and have been employed in many studies. Herein, the potential of memristors with CMOS-compatible 3D vertical stacked structures of Pt/Ti/HfO x /TiN-NCs/HfO x /TiN is examined for use in neuromorphic systems. The electrical characteristics (including I - V properties, retention, and endurance) were investigated for both planar single cells and vertical resistive random-access memory (VRRAM) cells at each layer, demonstrating their outstanding non-volatile memory capabilities. In addition, various synaptic functions (including potentiation and depression) under different pulse schemes, excitatory postsynaptic current (EPSC), and spike-timing-dependent plasticity (STDP) were investigated. In pattern recognition simulations, an improved recognition rate was achieved by the linearly changing conductance, which was enhanced by the incremental pulse scheme. The achieved results demonstrated the feasibility of employing VRRAM with TiN nanocrystals in neuromorphic systems that resemble the human brain.

Recent advancements in computer vision and neural networks have facilitated the medical imaging survival analysis for various medical applications. However, challenges arise when patients have multiple images from multiple lesions, as current deep learning methods provide multiple survival predictions for each patient, complicating result interpretation. To address this issue, we developed a deep learning survival model that can provide accurate predictions at the patient level. We propose a deep attention long short-term memory embedded aggregation network (DALAN) for histopathology images, designed to simultaneously perform feature extraction and aggregation of lesion images. This design enables the model to efficiently learn imaging features from lesions and aggregate lesion-level information to the patient level. DALAN comprises a weight-shared CNN, attention layers, and LSTM layers. The attention layer calculates the significance of each lesion image, while the LSTM layer combines the weighted information to produce an all-encompassing representation of the patient's lesion data. Our proposed method performed better on both simulated and real data than other competing methods in terms of prediction accuracy. We evaluated DALAN against several naive aggregation methods on simulated and real datasets. Our results showed that DALAN outperformed the competing methods in terms of c-index on the MNIST and Cancer dataset simulations. On the real TCGA dataset, DALAN also achieved a higher c-index of 0.803±0.006 compared to the naive methods and the competing models. Our DALAN effectively aggregates multiple histopathology images, demonstrating a comprehensive survival model using attention and LSTM mechanisms., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Kim, Lee. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Purely quantum electron systems exhibit intriguing correlated electronic phases by virtue of quantum fluctuations in addition to electron-electron interactions. To realize such quantum electron systems, a key ingredient is dense electrons decoupled from other degrees of freedom. Here, we report the discovery of a pure quantum electron liquid that spreads up to ~3 Å in a vacuum on the surface of an electride crystal. Its extremely high electron density and weak hybridization with buried atomic orbitals show the quantum and pure nature of the electrons, which exhibit a polarized liquid phase, as demonstrated by our spin-dependent measurement. Furthermore, upon enhancing the electron correlation strength, the dynamics of the quantum electrons change to that of a non-Fermi liquid along with an anomalous band deformation, suggestive of a transition to a hexatic liquid crystal phase. Our findings develop the frontier of quantum electron systems and serve as a platform for exploring correlated electronic phases in a pure fashion., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Complex electronic phases in strongly correlated electron systems are manifested by broken symmetries in the low-energy electronic states. Some mysterious phases, however, exhibit intriguing energy gap opening without an apparent signature of symmetry breaking (e.g., high- T C cuprates and heavy fermion superconductors). Here, we report an unconventional gap opening in a heterostructured, iron-based superconductor Sr 2 VO 3 FeAs across a phase transition at T 0 ∼150 K. Using angle-resolved photoemission spectroscopy, we identify that a fully isotropic gap opens selectively on one of the Fermi surfaces with finite warping along the interlayer direction. This band selectivity is incompatible with conventional gap opening mechanisms associated with symmetry breaking. These findings, together with the unusual field-dependent magnetoresistance, suggest that the Kondo-type proximity coupling of itinerant Fe electrons to localized V spin plays a role in stabilizing the exotic phase, which may serve as a distinct precursor state for unconventional superconductivity., Competing Interests: The authors declare no competing interest., (Copyright © 2021 the Author(s). Published by PNAS.)

The electronic states of Au-induced atomic nanowires on Ge(0 0 1) (Au/Ge(0 0 1) NWs) have been studied by angle-resolved photoelectron spectroscopy with linearly polarized light. We have found three electron pockets around the [Formula: see text] line, where the Fermi surfaces are closed in a surface Brillouin zone (SBZ). The results indicate 2D Fermi surfaces of Au/Ge(0 0 1) NWs whereas the atomic structure is 1D. On the basis of the polarization-dependent spectra, the relation between SBZ and the direction of the atomic NW, and the symmetry of the surface state are clarified. These are very useful for further studies on the atomic structure of NWs.

Surface states of platinum-induced atomic nanowires on a germanium (0 0 1) surface, which shows a structural phase transition at 80 K, were studied by angle-resolved photoelectron spectroscopy (ARPES). We observed four one-dimensional metallic surface states, among which, two bands were reported in our previous study (Yaji et al 2013 Phys. Rev. B 87 241413). One of the newly-found two bands is a quasi-one-dimensional state and is split into two due to the Rashba effect. Photoelectron intensity from one of the spin-polarized branches is reduced at a boundary of the surface Brillouin zone below the phase transition temperature. The reduction of the photoelectron intensity in the low temperature phase is interpreted as the interference of photoelectrons, not as the Peierls instability. We also discuss the low energy properties of the metallic surface states and their spin splitting using high-resolution ARPES with a vacuum ultraviolet laser.

Electron scattering in the topological surface state (TSS) of the topological insulator Bi1.5Sb0.5Te1.7Se1.3 was studied using quasiparticle interference observed by scanning tunneling microscopy. It was found that not only the 180° backscattering but also a wide range of backscattering angles of 100°-180° are effectively prohibited in the TSS. This conclusion was obtained by comparing the observed scattering vectors with the diameters of the constant-energy contours of the TSS, which were measured for both occupied and unoccupied states using time- and angle-resolved photoemission spectroscopy. The robust protection from backscattering in the TSS is good news for applications, but it poses a challenge to the theoretical understanding of the transport in the TSS.

Purpose: Focal cortical dysplasia (FCD) is the most common pathological diagnosis in patients who have undergone surgical treatment for intractable neocortical epilepsy. However, presurgical identification of MRI abnormalities in FCD patients remains difficult, and there are no highly sensitive imaging parameters available that can reliably differentiate among FCD subtypes. The purpose of our study was to investigate the surgical outcome in FCD patients with identifiable MRI abnormalities and to evaluate the prognostic role of the various MRI features and the characteristics of FCD pathology., Methods: We retrospectively recruited epilepsy patients who had undergone surgical treatment for refractory epilepsy with focal MRI abnormalities and the pathological diagnosis of FCD. We evaluated the surgical outcome according to the pathological subtypes, and studied the prognostic roles of various MRI features. We used recently proposed three-tiered FCD classification system which included FCD type III when FCD occurs in association with other potentially epileptogenic pathologies., Results: A total of 69 patients were included, and 68.1% of patients became seizure free. Patients with FCD type III had a lower chance for achieving seizure freedom (7/15) than in patients with isolated FCD (FCD types I and II) (40/54, p=0.044). Cortical thickness and blurring of gray-white matter junction were more common in isolated FCD than in FCD type III, but most MRI features failed to differentiate between FCD types I and II, and only the transmantle sign was specific for FCD type II. We failed to find a prognostic value of specific MRI abnormalities of prognostic value in terms of post-epilepsy surgery outcome in FCD patients., Conclusions: Our study showed that patients with FCD III have poor surgical outcome. Typical MRI features of isolated FCD such as cortical thickness and blurring of gray-white matter junction were less common in FCD type III and only transmantle sign was helpful in differentiating between FCD types I and II., (Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Objective: This study examined test-retest reliability, internal consistency, and construct and predictive validity of the Physical Activity and Nutrition Self-Efficacy (PANSE) scale, an 11-item instrument to assess weight-loss self-efficacy among postpartum women of lower income., Methods: Seventy-one women completed the PANSE scale and psychosocial measures at baseline and at 7 and 13 weeks of a pilot study of weight loss., Results: Test-retest reliability of PANSE scores was r = 0.55 (P < .01). Cronbach α was r = 0.89. Construct validity was supported by correlations with less-healthful behaviors (r = -0.33, P = .005), perceived stress (r = -0.24, P = .04), and decisional balance (r = 0.25, P = .03). PANSE change scores correlated with intervention group weight changes (r = -0.54, P < .01), although baseline scores did not. One factor emerged (loadings .80 to .57)., Conclusions and Implications: The PANSE scale demonstrated adequate reliability, internal consistency, construct validity, and moderate predictive validity. Replication is needed to confirm study findings., (Copyright © 2011 Society for Nutrition Education. Published by Elsevier Inc. All rights reserved.)

Developing focused and relevant health promotion interventions is critical for behavioral change in a low-resource or special population. Evidence-based interventions, however, may not match the specific population or health concern of interest. This article describes the Multisource Method (MSM), which, in combination with a workshop format, may be used by health professionals and researchers in health promotion program development. The MSM draws on positive deviance practices and processes, focus groups, community advisors, behavioral change theory, and evidence-based strategies. Use of the MSM is illustrated in the development of ethnic-specific weight loss interventions for low-income postpartum women. The MSM may be useful in designing future health programs designed for other special populations for whom existing interventions are unavailable or lack relevance.

Although siblings are thought to be influential in child development, little is known about the influence of sibling status on the health of older adults. Using structural equation modeling, the authors created and tested a series of models with data from a sample (N = 3,968) of 1957 high school graduates from the Wisconsin Longitudinal Study. The results indicated that socioeconomic status of origin, adolescent aptitude, and educational attainment did have significant total effects on health in later life, but sibling status did not. Adults who grew up in families of higher socioeconomic status and who had greater aptitude in high school attained more education, and this advantage, in turn, led to better health in later life. Although the final model was cross-validated, it was not equally plausible for men and women., (Copyright 2009 APA, all rights reserved)