7141 research outputs found
Sort by
Characterization of Mechanical Property Evolution and Durability Life Prediction of Engineered Cementitious Composites Under Frozen State
Full text linkEngineered cementitious composites (ECCs) exhibit superior mechanical properties (MPs) and excellent crack control capabilities, making them widely used in practical engineering applications. However, the MPs of ECCs in frozen states (FSs), particularly their flexural properties (FPs), still need to be better understood. MP tests were designed for frozen ECC samples to investigate the service performance of ECCs in an FS. The samples underwent 0 to 300 freeze–thaw cycles (FTs), followed by compressive and flexural tests at a constant freezing temperature of −18 °C. The compressive properties (CPs) and FPs of the samples and their influencing mechanisms were analyzed. Based on this analysis, a life prediction model (LPM) for freeze–thaw-damaged (FTD) ECCs was established using the entropy weight method and the GM(1,1) model to predict the durability changes of ECCs in FS. The results indicate that with an increasing number of FTs, the uniaxial compressive strength (CS), elastic modulus (E), initial crack strength, and ultimate strength of ECCs in the FS are higher than those in the thawed state (TS), with a notable increase in brittleness at ultimate failure. The overall stiffness of the specimens increased under high FTs. The established model effectively predicts the durability changes of ECCs in the FS
The Optimization of a T-Cell Resonator: Towards Highly Sensitive Photoacoustic Spectroscopy for Noninvasive Blood Glucose Detection
Full text linkNoninvasive blood glucose monitoring is crucial for diabetes management, and photoacoustic spectroscopy (PAS) offers a promising solution by detecting glucose levels through human skin. However, weak acoustic signals in PAS systems require optimized resonator designs for enhanced detection sensitivity. Designing such resonators physically is complex, requiring the precise identification of critical parameters before practical implementation. This study focused on optimizing a T-shaped photoacoustic resonator using finite element modeling in a COMSOL Multiphysics environment. By systematically varying the geometric design parameters of the T-cell resonator, a maximum increase in the pressure amplitude of 12.76 times with a quality factor (Q-factor) of 47.5 was achieved compared to the previously designed reference acoustic resonator. This study took a significant step forward by identifying key geometric parameters that influence resonator performance, paving the way for more sensitive and reliable noninvasive glucose monitoring systems
The Circuitous and Meandering Road to Voting Rights: The 60th Anniversary of the Voting Rights Act of 1965
Full text linkHigh-Salt Tumor Microenvironment: Not as Bad as It Sounds, Not as Good as It Seems
Full text linkRecent evidence suggests a high-sodium microenvironment in breast tumors. However, the exact role of this high-sodium microenvironment on tumorigenesis is unknown. Salt (sodium chloride, NaCl) is a well-known inflammatory molecule playing a significant role in various chronic ailments like cardiovascular and autoimmune diseases. Importantly, chronic inflammation is recognized as one of the major hallmarks of carcinogenesis. Breast cancer cell culture-based studies demonstrated that high-salt (HS) treatment (Δ35–50 mM NaCl) induced cancer cell proliferation. However, preclinical murine research showed reduced tumor progression kinetics in mice fed a short-term HS diet (4% NaCl diet, 0–2 weeks prior to the injection of tumor cells). Molecular studies demonstrated that the short-term HS diet induced the inflammatory activation of naïve CD4+ T cells to the Th17/Th1 anti-tumor phenotype. As human health-related adverse outcomes from HS diets usually occur as a consequence of prolonged HS intake over a period of several years, we have developed a novel chronic HS dietary murine tumor model. In this model, tumor cells are sequentially passaged (four cycles) in vivo under high-salt conditions, and tumor kinetics were analyzed in the passage-4 mice. These studies demonstrated enhanced tumor progression (pro-tumor) under chronic HS dietary conditions through the activation of tumor-initiating stem cells, along with the exhaustion of immune cells. Based on the, apparently paradoxical, evidence, we propose a comprehensive unifying hypothesis to elucidate the complex role of a high-sodium microenvironment towards tumor immune sculpting. This understanding will enable novel drug repositioning strategies, the development of unique ion channel-based anti-cancer therapeutics and promote low-salt diet intake in breast cancer patients on immunotherapy