In the search for high-energy density materials for Li-ion batteries, silicon has emerged as a promising candidate for anodes due to its ability to absorb a large number of Li atoms. Lithiation of Si leads to large deformation and concurrent changes in its mechanical properties, from a brittle material in its pure form to a material that can sustain large inelastic deformation in the lithiated form. These remarkable changes in behavior pose a challenge to theoretical treatment of the material properties. Here, we provide a detailed picture of the origin of changes in the mechanical properties, based on first-principles calculations of the atomic-scale structural and electronic properties in a model amorphous silicon (a-Si) structure. We regard the reactive flow of lithiated silicon as a nonequilibrium process consisting of concurrent Li insertion driven by unbalanced chemical potential and flow driven by deviatoric stress. The reaction enables the material to flow at a lower level of stress. Our theoretical model is in excellent quantitative agreement with experimental measurements of lithiation-induced stress on a Si thin film.
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http://dx.doi.org/10.1021/nl302261w | DOI Listing |
Clin Exp Med
January 2025
Department of Hepatobiliary Surgery, the First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Donafenib is an improved version of sorafenib in which deuterium is substituted into the drug's chemical structure, enhancing its stability and antitumor activity. Donafenib exhibits enhanced antitumor activity and better tolerance than sorafenib in preclinical and clinical studies. However, the specific mechanism of its effect on hepatocellular carcinoma has not been reported.
View Article and Find Full Text PDFNeuroimage
January 2025
Department of Radiology, Mayo Clinic, Rochester, MN, USA. Electronic address:
Cardiorespiratory signals have long been treated as "noise" in functional magnetic resonance imaging (fMRI) research, with the goal of minimizing their impact to isolate neural activity. However, there is a growing recognition that these signals, once seen as confounding variables, provide valuable insights into brain function and overall health. This shift reflects the dynamic interaction between the cardiovascular, respiratory, and neural systems, which together support brain activity.
View Article and Find Full Text PDFBackground: Tauopathies are a group of neurodegenerative disorders which are characterized by the accumulation of abnormal tau protein in the brain. However, the mechanistic understanding of pathogenic tau formation and spread within the brain remains elusive. Astrocytes are major immune reactive cells in the brain and have been implicated in exacerbating tau pathology by releasing extracellular vesicles (AEVs) containing pro-inflammatory cytokines and chemokines upon activation.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
University of California, San Francisco (UCSF), San Francisco, CA, USA.
Background: Microglia responses to Aβ and tau pathology and the dysregulation of the microglial role in synaptic function may determine the onset and course of Alzheimer's disease (AD). While significant work has been performed in mouse models, we still lack a complete understanding of physiological and pathological microglial states and functions in human AD brain.
Method: For immunoblotting of brain homogenates against multiple microglial markers, and flow cytometry (FC) analysis of synaptosomal fractions (SNAP25/CD47/Aβ(10G4)/phospho-tau(AT8)), 49 cryopreserved human parietal cortex samples were categorized into four groups: low pathology control (LPC), high Aβ control (HAC), high pathology control (HPC), and AD.
Alzheimers Dement
December 2024
University of Miami, Coral Gables, FL, USA.
Background: Cerebral blood flow is decreased in mouse models and patients of Alzheimer's disease (AD). We identified that about 2% of cortical capillaries in the APP/PS1 mouse model of AD had stalled blood flow due to neutrophils obstructing capillaries and contributing to vascular inflammation. Neutrophils are more reactive in AD.
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