16 research outputs found

    Quantifying Total Phosphorus and Heavy Metals in Residential Septage

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    Septic systems are used for wastewater treatment in rural areas. Septic tanks promote stratification of wastewater into solid (sludge and scum) and liquid layers. Pollutant concentrations in the layers of residential septic tanks may be highly variable, and thus septage pumped from tanks with different layer thicknesses may also be variable. The goal of this study was to quantify the total phosphorus (TP) and heavy metal concentrations and masses of residential septage. The solid and liquid layer thicknesses were measured in 37 septic tanks. Samples were collected from each layer for pollutant concentration analysis. The median TP concentration (10.6 mg L−1) was greatest in the sludge layer, followed by the scum (5.3 mg L−1) and liquid (1.8 mg L−1) layers. Concentrations of heavy metals were highly variable for each layer type. The masses of the TP, cadmium, copper, lead, nickel, and zinc contained median (range) values of 19.4 g (0.9–1041 g), <0.01 g (<0.01–1.99 g), 1.3 g (0.1–520 g), 1.8 g (<0.01–44.2 g), 1.3 g (<0.01–4.3 g), and 13.8 g (0.3–788 g), respectively. Since septage is typically applied on land as a soil amendment for crop growth, it is important that representative composite samples are collected to prevent excess buildup of TP and metals, which may harm yields or environmental health

    Supramolecular design of self-assembling nanofibers for cartilage regeneration

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    Molecular and supramolecular design of bioactive biomaterials could have a significant impact on regenerative medicine. Ideal regenerative therapies should be minimally invasive, and thus the notion of self-assembling biomaterials programmed to transform from injectable liquids to solid bioactive structures in tissue is highly attractive for clinical translation. We report here on a coassembly system of peptide amphiphile (PA) molecules designed to form nanofibers for cartilage regeneration by displaying a high density of binding epitopes to transforming growth factor β-1 (TGFβ-1). Growth factor release studies showed that passive release of TGFβ-1 was slower from PA gels containing the growth factor binding sites. In vitro experiments indicate these materials support the survival and promote the chondrogenic differentiation of human mesenchymal stem cells. We also show that these materials can promote regeneration of articular cartilage in a full thickness chondral defect treated with microfracture in a rabbit model with or even without the addition of exogenous growth factor. These results demonstrate the potential of a completely synthetic bioactive biomaterial as a therapy to promote cartilage regeneration

    Additional file 8: Table S8. of Neurogenin 3 is regulated by neurotrophic tyrosine kinase receptor type 2 (TRKB) signaling in the adult human exocrine pancreas

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    Genes involved with neurotrophin signaling. List of 320 genes annotated as being involved with, or downstream of, neurotrophin signaling. (DOCX 148 kb

    Additional file 1: Figure S1. of Cryptic protein-protein interaction motifs in the cytoplasmic domain of MHCI proteins

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    Categorization of PDZ ligands. The current study made use of forms of Lenfant et al.’s [44] and Nourry et al.’s [46] criteria to identify potential PDZ ligand motifs in MHCI proteins. Related rules were proposed in [45]. (PPTX 35 kb

    Autologous engineering of cartilage

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    Treatment of full-thickness damage to hyaline cartilage is hampered by the limited availability of autologous healthy cartilage and the lengthy, cost-prohibitive cell isolation and expansion steps associated with autologous cartilage implantation (ACI). Here we report a strategy for de novo engineering of ectopic autologous cartilage (EAC) within the subperiosteal space (in vivo bioreactor), through the mere introduction of a biocompatible gel that might promote hypoxia-mediated chondrogenesis, thereby effectively overcoming the aforementioned limitations. The EAC is obtained within 3 wk post injection of the gel, and can be press-fit into an osteochondral defect where it undergoes remodeling with good lateral and subchondral integration. The implanted EAC showed no calcification even after 9 mo and attained an average O’Driscoll score of 11 (versus 4 for controls). An “on demand” autologous source of autologous cartilage with remodeling capacity is expected to significantly impact the clinical options in repair of trauma to articular cartilage
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