Background: While coronary artery plaque burden and stenosis are important for development of ischemia, the role of lumen size remains underexplored. This study evaluated the relationship between average lumen area (ALA) and vessel-specific ischemia beyond diameter stenosis (DS) and percent atheroma volume (PAV).

Methods: This post-hoc analysis included coronary arteries from the CREDENCE (n ​= ​1716) and PACIFIC-1 (n ​= ​612) trials, involving patients with suspected stable coronary artery disease (CAD) who underwent coronary computed tomography angiography (CTA) and invasive fractional flow reserve (FFR) measurement. AI-enabled quantitative CTA was used to assess plaque burden and composition. Ischemia was defined as FFR≤0.80. Each major coronary artery was analyzed. ALA was stratified into tertiles.

Results: Larger ALA was associated with younger age, higher body mass index, and more nitrate use in both cohorts (all p ​< ​0.05). Increasing ALA correlated with lower diameter stenosis, reduced ischemia prevalence, and smaller plaque burden despite greater total plaque and non-calcified plaque volumes. In both cohorts, ischemia prevalence increased with stenosis severity, yet within each stenosis category, vessels with smaller ALA showed consistently higher ischemia rates. E.g., in CREDENCE vessels with 50 ​%-70 ​% stenosis, ischemia was observed in 60.0 ​% of small, 43.8 ​% of medium, and 27.8 ​% of large vessels (all p ​< ​0.05). Similar patterns were observed within PAV strata across all plaque subtypes. Multivariable analysis confirmed ALA independently associated with lower ischemia prevalence in both studies (both p ​< ​0.001).

Conclusions: Coronary artery lumen size significantly attenuates the relationship between atherosclerosis/stenosis and ischemia. These findings support integrating lumen assessment in coronary CTA-based risk stratification.

Keywords: Coronary CT angiography; Coronary artery disease; Ischemia; Lumen size; Plaque burden.     

Physiologically relevant 3D tumor models incorporating extracellular matrix (ECM) and cancer-associated fibroblasts (CAFs) are essential for studying tumor progression and drug resistance, yet often suffer from hydrogel contraction and instability-especially in microfluidic formats, where ECM deformation hampers long-term culture and quantitative imaging. Here, we present a microfluidic tumor-fibroblast co-culture platform for head and neck squamous cell carcinoma (HNSCC) that overcomes these limitations via a dual strategy: APTES-mediated surface silanization anchors the ECM to the chip, combined with Genipin-based crosslinking, which modestly increases hydrogel stiffness and progressively reinforces the network without compromising cell viability, as confirmed by time- and frequency-resolved rheology. Fourier-transform infrared spectroscopy (FTIR) verified successful collagen crosslinking while preserving reactive & horbar;OH and & horbar;NH2 groups, enabling covalent bonding to the APTES-functionalized chip. The platform further integrates semi-automated segmentation and high-content imaging to quantify dynamic phenotypic drug responses at both single-cell and multicellular/tissue organization levels. Drug chemosensitivity assays, including co-culture with patient-derived CAFs, enabled quantitative assessment of clinically relevant chemoprotective effects. By combining biomaterial engineering with functional microfluidic design, this system enables reproducible, physiologically relevant modeling of tumor-fibroblast interactions, offering a scalable tool for preclinical drug chemosensitivity screening and clinical translation.

We conduct a photometric study of star clusters (or knots) in the collisional ring galaxy (CRG) Arp 147 to trace the star formation history across its empty ring. Using Hubble Space Telescope F450W, F606W, and F814W images, we find that Arp 147 hosts 211 knots and six kpc-size clumps, nearly 60 per cent of which have ages below 10 Myr, and two-thirds have masses above 10⁵ M ⁠. The cluster mass function (CMF) of knots with ages between 100-200 Myr deviates from a power-law and follows a Schechter function with a characteristic truncation mass of M_c = 6.2 × 10⁵ M ⁠. This shape of the CMF is more prominent for a subsample of knots in the eastern region of the ring. Over the same age interval, we derive a low rate of disruption (δ ∼ 0.25⁠⁠) from the cluster age function and a cluster formation efficiency (CFE) of ∼3 per cent. In contrast, the CFE in the 1-10 Myr age range is nearly 40 per cent. We note the lack of high-resolution ultraviolet and Hα observations to help break age–extinction degeneracy which affects the derived ages for dusty young clusters and old ones with low reddening. Nevertheless, this study has shown, at least to a first-order approximation, that collision-triggered starburst events happening across the CRG offer an ideal environment for a second generation of young blue knots to form in abundance. It also suggests that the drop-through collision between the two galaxies can fuel at least mild cluster disruption over time.