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Intrinsically stretchable sensory-neuromorphic system for sign language translation
No full textSoft wearable strain sensors with mechanically invisible interactions with skin tissue have enabled precise diagnosis and effective treatment of neurological movement disorders in a closed-loop manner that quantitatively measures motion-related strains without noise intervention and provides feedback information. Because of the immediate interpretation from motion-driven sign language to general conversation, such on-skin strain sensors have recently been considered promising candidates for facilitating communication either within deaf and hard-of-hearing communities or among people with disabilities. Despite advances in soft strain sensors, the lack of intrinsically stretchable neuromorphic modules that mimic biological synapses and efficiently perform neural computation and dynamics has resulted in inaccurate translation of sign language. In this study, we present an intrinsically stretchable organic electrochemical transistor (is-OECT) synapse integrated with crack-based strain sensors conformally mounted onto fingers to implement an interactive sensory-neuromorphic system (iSNS) capable of overcoming auditory impediments. The is-OECT synapse in the iSNS shows stable electrical performance (a large number of states (∼100 states) and a linear weight update) in the skin deformation range (approximately 30%). Based on pre-trained data gathered from on-finger strain-sensing information, the iSNS wirelessly translates sign language while maintaining high accuracy. © 2024 Elsevier Ltd11Nsciescopu
Combined radiomics-clinical model to predict platinum-sensitivity in advanced high-grade serous ovarian carcinoma using multimodal MRI
No full textIntroduction We aimed to predict platinum sensitivity using routine baseline multimodal magnetic resonance imaging (MRI) and established clinical data in a radiomics framework.Methods We evaluated 96 patients with ovarian cancer who underwent multimodal MRI and routine laboratory tests between January 2016 and December 2020. The patients underwent diffusion-weighted, contrast-enhanced T1-weighted, and T2-weighted MRI. Subsequently, 293 radiomic features were extracted by manually identifying tumor regions of interest. The features were subjected to the least absolute shrinkage and selection operators, leaving only a few selected features. We built the first prediction model with a tree-based classifier using selected radiomics features. A second prediction model was built by combining the selected radiomic features with four established clinical factors: age, disease stage, initial tumor marker level, and treatment course. Both models were built and tested using a five-fold cross-validation.Results Our radiomics model predicted platinum sensitivity with an AUC of 0.65 using a few radiomics features related to heterogeneity. The second combined model had an AUC of 0.77, confirming the incremental benefits of the radiomics model in addition to models using established clinical factors.Conclusion Our combined radiomics-clinical data model was effective in predicting platinum sensitivity in patients with advanced ovarian cancer.11Ysciescopu
Mapping cerebral perfusion in mice under various anesthesia levels using highly sensitive BOLD MRI with transient hypoxia
No full textCerebral perfusion is critical for the early detection of neurological diseases and for effectively monitoring disease progression and treatment responses. Mouse models are widely used in brain research, often under anesthesia, which can affect vascular physiology. However, the impact of anesthesia on regional cerebral blood volume and flow in mice has not been thoroughly investigated. In this study, we have developed a whole-brain perfusion MRI approach by using a 5-second nitrogen gas stimulus under inhalational anesthetics to induce transient BOLD dynamic susceptibility contrast (DSC). This method proved to be highly sensitive, repeatable within each imaging session, and across four weekly sessions. Relative cerebral blood volumes measured by BOLD DSC agree well with those by contrast agents. Quantitative cerebral blood volume and flow metrics were successfully measured in mice under dexmedetomidine and various isoflurane doses using both total vasculature-sensitive gradient-echo and microvasculature-sensitive spin-echo BOLD MRI. Dexmedetomidine reduces cerebral perfusion, while isoflurane increases cerebral perfusion in a dose-dependent manner. © 2024 American Association for the Advancement of Science. All rights reserved.11Ysciescopu
Climatological Madden-Julian Oscillation during boreal spring leads to abrupt Australian monsoon retreat and Asian monsoon onsets
No full textAbrupt monsoon onsets/retreats are indispensable targets for climate prediction and future projection, but the origins of their abruptness remain elusive. This study establishes the existence of three climatological Madden-Julian Oscillation (CMJO) episodes contributing to the rapid Australian summer monsoon retreat in mid-March, the South China Sea (or East Asian) summer monsoon onset in mid-May, and the Indian summer monsoon onset in early June. The CMJO displays a dynamically coherent convection-circulation structure resembling its transitionary counterpart, demonstrating its robustness as a convectively coupled circulation system and the tendency of the transient MJOs' phase-lock to the annual cycle. The CMJO is inactive during the boreal winter due to destructive year-to-year modulations of El Nino-Southern Oscillation. We hypothesize that the interaction between atmospheric internal variability (MJO) and the insolation-forced slow annual cycle generates the sudden monsoon withdrawal/onset during the boreal spring. Understanding the factors determining the timing and location of the MJO's phase-locking and its variability is vital for monsoon forecasting and climate projection.11Ysciescopu
Northern Hemisphere Extratropical Cyclone Clustering in ERA5 Reanalysis and the CESM2 Large Ensemble
No full textExtratropical cyclones are a dominant feature of the midlatitudes, and often occur as storm sequences. This phenomenon is known as cyclone clustering, which is common over regions like the eastern North Atlantic and western Europe. Here, intense clustered cyclones may lead to large cumulative socioeconomic impacts. There are several different approaches to quantify cyclone clustering, but a detailed evaluation on how clustering may change in a warmer climate is missing. We perform a cyclone clustering analysis for the Northern Hemisphere midlatitudes using the ERA5 reanalysis to characterize clustering during 1980-2020. Moreover, we use large ensemble simulations of the Community Earth System Model version 2 following the SSP3-7.0 scenario to compare clustering during 2060-2100 to 1980-2020. Our model simulations show significant enhancement in cyclone clustering over Europe for 3 and 4 cyclones within 7 days in the future decades, which is increasing by up to 25% on average during 2060-2100 compared to 1980-2020. In contrast, cyclone clustering decreases along the west coast of the United States and Canada by up to 24.3% and by 10.1% in the Gulf of Alaska for the same periods. In a warmer climate, clustered cyclones have lower minimum pressure and larger radii and depths compared to nonclustered events. Our findings suggest that change in future cyclone clustering depends on regions affected by global warming, with implications for the cumulative windstorm risk.11Nsciescopu
Correlation of Work Function and Conformation of C80 Endofullerenes on <i>h</i>-BN/Ni(111)
No full textChange of conformation or polarization of molecules is an expression of their functionality. If the two correlate, electric fields can change the conformation. In the case of endofullerene single-molecule magnets the conformation is linked to an electric and a magnetic dipole moment, and therefore magnetoelectric effects are envisoned. The interface system of one monolayer Sc2TbN@C-80 on hexagonal boron nitride (h-BN) on Ni(111) has been studied. The molecular layer is hexagonally close packedbut incommensurate. With photoemission the polarization and the conformation of the molecules are addressed by the work function and angular intensity distributions. Valence band photoemission (ARPES) shows a temperature-induced energy shift of the C-80 molecular orbitals that is parallel to a change in work function of 0.25 eV without charging the molecules. ARPES indicates a modification in molecular conformations between 30 and 300 K. This order-disorder transition involves a polarization change in the interface and is centered at 125 K as observed with high-resolution X-ray photoelectron spectroscopy (XPS). The temperature dependence is described with a thermodynamic model that accounts for disordering with an excitation energy of 74 meV into a high entropy ensemble. All experimental results are supported by density functional theory (DFT).11Ysciescopu
Dephasing Dynamics Accessed by High Harmonic Generation: Determination of Electron-Hole Decoherence of Dirac Fermions
No full textWe reveal the critical effect of ultrashort dephasing on the polarization of high harmonic generation in Dirac fermions. As the elliptically polarized laser pulse falls in or slightly beyond the multiphoton regime, the elliptically polarized high harmonic generation is produced and exhibits a characteristic polarimetry of the polarization ellipse, which is found to depend on the decoherence time T2. T2 could then be determined to be a few femtoseconds directly from the experimentally observed polarimetry of high harmonics. This shows a sharp contrast with the semimetal regime of higher pump intensity, where the polarimetry is irrelevant to T2. An access to the dephasing dynamics would extend the prospect of high harmonic generation into the metrology of a femtosecond dynamic process in the coherent quantum control. © 2024 American Chemical Society.11Nsciescopu
https://2DMat.ChemDX.org: Experimental data platform for 2D materials from synthesis to physical properties
No full textWe present a comprehensive data platform for 2D materials research, https://2DMat.ChemDX.org, and a newly constructed 2D database collected through the platform. This platform integrates efficient data management, specialized visualization, and machine learning toolkits, enhancing research productivity. The platform supports data obtained from reflection high-energy electron diffraction (RHEED), photoluminescence (PL), and Raman measurements, providing a robust foundation for uploading, managing, and sharing research data through a web-based platform. Data templates and parsing systems specialized for handling these data help researchers manage large datasets, reduce manual efforts, and enhance data consistency. The platform features powerful analysis tools for RHEED, PL, and Raman spectra, facilitating easy data comprehension with just a few clicks. Additionally, the platform incorporates machine learning toolkits for investigating 2D film growth mechanisms and super-resolution techniques for analyzing PL/Raman mapping data, promising an increase in efficiency. The modular design and the systematic 2D database of our platform enable not only seamless expansion and adaptation but also valuable data collection, management, and utilization in the evolving field of 2D materials. © 2024 RSC.11Yscopu
Product structure of graph classes with bounded treewidth
No full textWe show that many graphs with bounded treewidth can be described as subgraphs of the strong product of a graph with smaller treewidth and a bounded-size complete graph. To this end, define the underlying treewidth of a graph class to be the minimum non-negative integer such that, for some function , for every graph there is a graph with such that is isomorphic to a subgraph of . We introduce disjointed coverings of graphs and show they determine the underlying treewidth of any graph class. Using this result, we prove that the class of planar graphs has underlying treewidth ; the class of -minor-free graphs has underlying treewidth (for ); and the class of -minor-free graphs has underlying treewidth . In general, we prove that a monotone class has bounded underlying treewidth if and only if it excludes some fixed topological minor. We also study the underlying treewidth of graph classes defined by an excluded subgraph or excluded induced subgraph. We show that the class of graphs with no subgraph has bounded underlying treewidth if and only if every component of is a subdivided star, and that the class of graphs with no induced subgraph has bounded underlying treewidth if and only if every component of is a star.11Nsciescopu
Monitoring the synthesis of neutral lipids in lipid droplets of living human cancer cells using two-color infrared photothermal microscopy
No full textThere has been growing interest in the functions of lipid droplets (LDs) due to recent discoveries regarding their diverse roles. These functions encompass lipid metabolism, regulation of lipotoxicity, and signaling pathways that extend beyond their traditional role in energy storage. Consequently, there is a need to examine the molecular dynamics of LDs at the subcellular level. Two-color infrared photothermal microscopy (2C-IPM) has proven to be a valuable tool for elucidating the molecular dynamics occurring in LDs with sub-micrometer spatial resolution and molecular specificity. In this study, we employed the 2C-IPM to investigate the molecular dynamics of LDs in both fixed and living human cancer cells (U2OS cells) using the isotope labeling method. We investigated the synthesis of neutral lipids occurring in individual LDs over time after exposing the cells to excess saturated fatty acids while simultaneously comparing inherent lipid contents in LDs. We anticipate that these research findings will reveal new opportunities for studying lesser-known biological processes within LDs and other subcellular organelles. © 2024 The Royal Society of Chemistry.11Ysciescopu