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EMT induction in normal breast epithelial cells by COX2-expressing fibroblasts
No full textBackgroundThe tumor microenvironment (TME) plays a pivotal role in cancer progression, with cancer-associated fibroblasts (CAFs) significantly influencing tumor behavior. Especially, elevated COX2 expressing fibroblasts within the TME, notably in collagen-dense tumors like breast cancer, has been recently emphasized in the literature. However, the specific effect of COX2-expressing CAFs (COX2+ CAFs) on neighboring cells and their consequent role in cancer progression is not fully elucidated.MethodsWe induced COX2+ fibroblasts by forcing the fibroblasts forming aggregates to undergo Nemosis as a proxy for COX2+ CAFs. This approach enabled us to simulate the paracrine interactions between COX2+ CAFs and normal breast epithelial cells via conditioned media from COX2+ fibroblasts. We developed an innovative in vitro platform that combines cell mechanics-based analysis and biomolecular assays to study the interactions between COX2+ fibroblasts and normal breast epithelial cells. By focusing on the mechanical characteristics of the cells and the epithelial-mesenchymal transition (EMT) marker expressions, we aimed to elucidate the paracrine mechanisms through which COX2+ CAFs influence the tumor microenvironment.ResultsOur in vitro findings demonstrate that COX2+ fibroblasts, through conditioned media, induce significant alterations in the mechanical behavior of normal breast epithelial cells, as evidenced by monolayer expansion measurements using traction force microscopy (TFM). This transition was further corroborated by single-cell morphology and motility analyses, as well as increased expression of mesenchymal markers, including SNAI1 at the mRNA level and vimentin at the protein level. EP4 inhibition partially reversed these changes, preserving cell-cell interactions, limiting monolayer expansion, and reducing mesenchymal-like features, suggesting that PGE2-EP4 signaling plays a key role in mediating the paracrine effects of COX2+ fibroblasts. Together, our findings support a model in which PGE2-EP4 signaling contributes to EMT induction, potentially involving SNAI1 regulation, with implications for targeting stromal-epithelial interactions in breast cancer.ConclusionThis study advances our understanding of the potential mechanisms by which COX2+ CAFs influence tumor progression within the breast tumor microenvironment (TME) through controlled in vitro investigations. By integrating cell mechanics-based analysis, biomolecular assays, and innovative in vitro cell-based modeling of COX2+ CAFs, we have delineated the contributory role of these cells in a controlled setting. These insights lay a groundwork for future studies that could explore the implications of these findings in vivo, potentially guiding targeted therapeutic strategies.
Impact parameter selective Rydberg atom collision by optical tweezers
No full textOptical tweezers are used to facilitate cold collisions between two Rydberg rubidium atoms (87Rb) by controlling the impact parameter and collision energy. One atom is held stationary while the other is propelled to a constant velocity. After the tweezers are deactivated, both atoms are excited to a Rydberg state using a pi-pulse. Following the collision, a second pi-pulse is applied. If the stationary atom undergoes minimal momentum transfer and returns to its ground state, it can be recaptured when the tweezer is reactivated. The collision probability as a function of the impact parameter is extracted from the atom loss in the tweezer and used to determine the collisional cross section between Rydberg atoms. Numerical simulations of elastic two-body collisions agree well with the experimental data, providing valuable insights into the parameter regime where quantum effects will become important.
Criteria-Aware Graph Filtering: Extremely Fast Yet Accurate Multi-Criteria Recommendation
No full textMulti-criteria (MC) recommender systems, which utilize MC rating information for recommendation, are increasingly widespread in various e-commerce domains. However, the MC recommendation using training-based collaborative filtering, requiring consideration of multiple ratings compared to single-criterion counterparts, often poses practical challenges in achieving state-of-the-art performance along with scalable model training. To solve this problem, we propose CA-GF, a training-free MC recommendation method, which is built upon criteria-aware graph filtering for efficient yet accurate MC recommendations. Specifically, first, we construct an item–item similarity graph using an MC user-expansion graph. Next, we design CA-GF composed of the following key components, including 1) criterion-specific graph filtering where the optimal filter for each criterion is found using various types of polynomial low-pass filters and 2) criteria preference-infused aggregation where the smoothed signals from each criterion are aggregated. We demonstrate that CA-GF is (a) efficient: providing the computational efficiency, offering the extremely fast runtime of less than 0.2 seconds even on the largest benchmark dataset, (b) accurate: outperforming benchmark MC recommendation methods, achieving substantial accuracy gains up to 24% compared to the best competitor, and (c) interpretable: providing interpretations for the contribution of each criterion to the model prediction based on visualizations
Energy absorption of braided composite tubes under quasi-static combined shear-compression loading
No full textIn this paper, the energy absorption performance of braided composite tubes under combined shear-compression loading is investigated. ABAQUS/Explicit is employed to analyze the energy absorption of braided composite tubes, and quasi-static compression tests are carried out. Braided composite materials absorb energy through the damage accumulation in laminate. Thus, to maximize energy absorption performance, a progressive crushing mode should be induced. While extensive research has been conducted on cases of axial loading, understanding of the energy absorption performance of braided composite tubes under combined shear-compression loading remains limited. Experimental results reveal that under both axial and combined shear-compression loading at 30 degrees, the braided composite tube exhibits a progressive crushing mode. The test results are utilized to validate the finite element model. Through finite element analysis, it is confirmed that the damage accumulation in laminate is maximized due to the induction of a progressive crushing mode. It means that the energy absorption principles of braided composites apply similarly to combined shear-compression loading, allowing for the maintenance of superior energy absorption performance of braided composites under various load angles.
iBridge: genome-wide overexpression and downregulation target prediction tool based on the sum of covariances of the outgoing reaction fluxes
No full textMicrobial Synthesis of Carminic Acid: A Sustainable Alternative to Insect-Derived Production
No full textDevelopment of a Synthetic sRNA Platform for Targeted and HighThroughput Gene Knockdown in Diverse Bacteria
No full textQuantitative mapping of renal oxygen consumption using pseudo-continuous arterial spin labeling and quantitative susceptibility mapping in humans
No full textPurpose: To propose a new method for quantitatively mapping the renal metabolic rate of oxygen (RMRO2) and to evaluate the proposed method using a caffeine challenge. Theory and Methods: Pseudo-continuous arterial spin labeling (pCASL) and QSM sequences were used to obtain MR images in the kidney. Six healthy volunteers were scanned on caffeine and control days. The pCASL and QSM images were registered using DICOM information and rigid translation. The Fick principle was applied to estimate RMRO2. The results on caffeine and control days were compared to evaluate the capability of the proposed method to estimate renal oxygen consumption. A paired t-test was used to assess the statistical significance. Results: Estimated renal blood flow (RBF), QSM, and RMRO2 maps were consistent with those reported in the literature. RMRO2 values were higher than the cerebral metabolic rate of oxygen (CMRO2) and were significantly reduced on the caffeine days compared to the control days, consistent with findings from non-MRI literature. Conclusion: The feasibility of measuring renal oxygen consumption using pCASL and QSM images was demonstrated. To the best of our knowledge, this work provides quantitative maps of renal oxygen consumption in humans for the first time. The results were consistent with the literature, including the statistically significant reduction in renal oxygen consumption with caffeine challenge. These findings suggest the potential utility of our technique in measuring renal oxygen consumption noninvasively, especially for patients with complications associated with contrast agents.
Tunable Infrared Emissivity Using Laser-Sintered Liquid Metal Nanoparticle Films
No full textThis paper describes laser exposure to tune the infrared (IR) emissivity of a film of eutectic gallium indium (EGaIn) particles. EGaIn - a liquid metal at room temperature - forms a native oxide that keeps particles of the metal from spontaneously percolating. Photothermal energy from a CO2 laser percolates the particles into a conductive network. Here, it also causes a decrease in the IR emissivity of the film of particles from 0.4 to 0.24 over the range of 7.5-13 mu m wavelength (measured by an IR camera) with the increase of laser fluence from 1.4 to 1.9 J cm-2. The particles percolate most prominently at the bottom of the film, and thus, the apparent surface roughness does not change with laser exposure. This finding suggests the decrease in emissivity is not due to changes in the film's topography. Instead, the change in IR emissivity is attributed to a loss of the surface plasmonic resonance effect of EGaIn particles in the IR range after the sintering, which is confirmed by optical simulations. As a demonstration, it is shown that the ability to change the emissivity makes it possible to encrypt messages and camouflage laser-processed patterns.