200871 research outputs found
Sort by
EACVI survey on the current multi-modality imaging practice in patients with tricuspid regurgitation
No full textAdaptive contrastive hierarchical clustering with nodes visualization
No full textDeep clustering has been dominated by flat models that split a dataset into a predefined number of groups. Although recent methods achieve an extremely high similarity to the ground truth on popular benchmarks, the information contained in a flat partition is limited. In this paper, we introduce CoHiClust, a Contrastive Hierarchical Clustering model based on deep neural networks, which can be applied to typical image data. By employing a self-supervised learning approach, CoHiClust distills the base network into a binary tree without access to any labeled data. The hierarchical clustering structure can be used to analyze the relationship between clusters, as well as to measure the similarity between data points. In addition to the hierarchical structure we propose two visualization techniques, which allow us to deliver an intuitive explanation of tree nodes. Experiments demonstrate that CoHiClust generates a reasonable structure of clusters, which is consistent with our intuition and image semantics. Moreover, it obtains superior clustering accuracy on most of the image datasets compared to the state-of-the-art flat clustering models
Nano bio-responsive systems avoiding methicillin resistant <i>Staphylococcus aureus</i> colonization on an implant surface
No full textBiomaterial-associated infections caused by Staphylococcus aureus represent a race between bacterial colonization and mammalian cell integration on implant surfaces. If bacteria win, biofilm forms, often causing persistent infection. To favor host cells, we developed a nano bio-responsive system (NanoBioRS) with two synergistic defense lines. The first is a bio-adhesive surface with polymer brushes that recruit mammalian cells. The second is a nano-bioactive coating of polyphosphate-encapsulated chimeric phage endolysin nanoparticles (M23-PP), activated by alkaline phosphatase—an enzyme vital for bone development and biofilm life cycle.
Using metal-free surface-initiated atom transfer radical polymerization, we synthesized poly(polyethylene glycol methacrylate) (PPEGMA), poly(glycidyl methacrylate) (PGMA), and their block copolymer polymer brushes. These brushes were characterized via ellipsometry, FTIR, contact angle, and XPS. Functionalization with Arg-Gly-Asp (RGD) peptide enhanced MC3T3-E1 preosteoblast recruitment, as confirmed by fluorescence microscopy. Further bioactivation with M23-PP nanoparticles provided targeted antibacterial action. NanoBioRS was biocompatible and its efficacy was validated through competitive colonization assays with methicillin sensitive or resistant S. aureus, together with MC3T3-E1 cells. This biocompatible platform shows strong potential to prevent bacterial colonization of implants
Cortical thinning and volumetric alterations in patients with unruptured intracranial aneurysms : insights from surface-based morphometry
No full text
