Biological nitrogen removal of high-strength ammonium industrial wastewater with two-sludge system

The biological nitrogen removal (BNR) process is the most common method for removing low quantities of ammonium from wastewater, but this is not the usual treatment for high-strength ammonium wastewater. The capacity to biologically remove the nitrogen content of a real industrial wastewater with a concentration of 5000 g N-NH(4)(+) L(-1) is demonstrated in this work. The experimental system used is based on a two-sludge system, with a nitrifying activated sludge and a denitrifying activated sludge. This system treated real industrial wastewater for 450 days, and during this period, it showed the capacity for oxidizing all the ammonium at average nitrification rates between 0.11 and 0.18 g N-NH(4)(+)g VSS(-1)d(-1). Two key process parameters were evaluated: the maximum nitrification rate (MNR) and the maximum denitrification rate (MDR). MNR was determined in continuous operation at three different temperatures: 15 degrees C, 20 degrees C and 25 degrees C, obtaining values of 0.10, 0.21 and 0.37 g N-NH(4)(+) g VSS(-1)d(-1), respectively. Complete denitrification was achieved using two different industrial carbon sources, one containing mainly ethanol and the other one methanol. The MDR reached with ethanol (0.64 g N-NO(x)(-) g VSS(-1)d(-1)) was about 6 times higher than the MDR reached with methanol (0.11g N-NO(x)(-)g VSS(-1)d(-1)).     

Geodesic Active Contours

A novel scheme for the detection of object boundaries is presented. The technique is based on active contours evolving in time according to intrinsic geometric measures of the image. The evolving contours naturally split and merge, allowing the simultaneous detection of several objects and both interior and exterior boundaries. The proposed approach is based on the relation between active contours and the computation of geodesics or minimal distance curves. The minimal distance curve lays in a Riemannian space whose metric is defined by the image content. This geodesic approach for object segmentation allows to connect classical snakes based on energy minimization and geometric active contours based on the theory of curve evolution. Previous models of geometric active contours are improved, allowing stable boundary detection when their gradients suffer from large variations, including gaps. Formal results concerning existence, uniqueness, stability, and correctness of the evolution are presented as well. The scheme was implemented using an efficient algorithm for curve evolution. Experimental results of applying the scheme to real images including objects with holes and medical data imagery demonstrate its power. The results may be extended to 3D object segmentation as well.     

Capturing “Extraordinary” Soft‐Assembled Charge‐Like Polypeptides as a Strategy for Nanocarrier Design

The rational design of nanomedicines is a challenging task given the complex architectures required for the construction of nanosized carriers with embedded therapeutic properties and the complex interface of these materials with the biological environment. Herein, an unexpected charge‐like attraction mechanism of self‐assembly for star‐shaped polyglutamates in nonsalty aqueous solutions is identified, which matches the ubiquitous “ordinary–extraordinary” phenomenon previously described by physicists. For the first time, a bottom‐up methodology for the stabilization of these nanosized soft‐assembled star‐shaped polyglutamates is also described, enabling the translation of theoretical research into nanomaterials with applicability within the drug‐delivery field. Covalent capture of these labile assemblies provides access to unprecedented architectures to be used as nanocarriers. The enhanced in vitro and in vivo properties of these novel nanoconstructs as drug‐delivery systems highlight the potential of this approach for tumor‐localized as well as lymphotropic delivery.     

Bioluminescent nanopaper for rapid screening of toxic substances

Environmental pollution is threatening human health and ecosystems as a result of modern agricultural techniques and industrial progress. A simple nanopaper-based platform coupled with luminescent bacteria Aliivibrio fischeri (A. fischeri) as a bio-indicator is presented here, for rapid and sensitive evaluation of contaminant toxicity. When exposed to toxicants, the luminescence inhibition of A. fischeri-decorated bioluminescent nanopaper (BLN) can be quantified and analyzed to classify the toxicity level of a pollutant. The BLN composite was characterized in terms of morphology and functionality. Given the outstanding biocompatibility of nanocellulose for bacterial proliferation, BLN achieved high sensitivity with a low cost and simplified procedure compared to conventional instruments for laboratory use only. The broad applicability of BLN devices to environmental samples was studied in spiked real matrices (lake and sea water), and their potential for direct and in situ toxicity screening was demonstrated. The BLN architecture not only survives but also maintains its function during freezing and recycling processes, endowing the BLN system with competitive advantages as a deliverable, ready-to-use device for large-scale manufacturing. The novel luminescent bacteria-immobilized, nanocelullose-based device shows outstanding abilities for toxicity bioassays of hazardous compounds, bringing new possibilities for cheap and efficient environmental monitoring of potential contamination.

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Anticancer Activity Driven by Drug Linker Modification in a Polyglutamic Acid‐Based Combination‐Drug Conjugate

Combination nanotherapies for the treatment of breast cancer permits synergistic drug targeting of multiple pathways. However, poor carrier degradability, poor synergism of the combined drugs, low drug release regulation, and a lack of control on final macromolecule solution conformation (which drives the biological fate) limit the application of this strategy. The present study describes the development of a family of drug delivery systems composed of chemotherapeutic (doxorubicin) and endocrine therapy (aromatase inhibitor aminoglutethimide) agents conjugated to a biodegradable poly‐l ‐glutamic acid backbone via various linking moieties. Data from in vitro cytotoxicity and drug release assessments and animal model validation select a conjugate family member with optimal biological performance. Exhaustive physicochemical characterization in relevant media (including the study of secondary structure, size measurements, and detailed small‐angle neutron scattering analysis) correlates biological data with the intrinsic supramolecular characteristics of the conjugate. Overall, this study demonstrates how a small flexible Gly linker can modify the spatial conformation of the entire polymer–drug conjugate, promote the synergistic release of both drugs, and significantly improve biological activity. These findings highlight the need for a deeper understanding of polymer–drug conjugates at supramolecular level to allow the design of more effective polymer–drug conjugates.     

In Vivo Imaging of MMP‐13 Activity Using a Specific Polymer‐FRET Peptide Conjugate Detects Early Osteoarthritis and Inhibitor Efficacy

Imaging early molecular changes in osteoarthritic (OA) joints is instrumental for the development of disease‐modifying drugs. To this end, a fluorescent resonance energy transfer‐based peptide probe that is cleavable by matrix metalloproteinase 13 (MMP‐13) has been developed. This protease degrades type II collagen, a major matrix component of cartilage. The probe exhibits high catalytic efficiency (k_cat/K_M = 6.5 × 10⁵m ^?1 s^?1) and high selectivity for MMP‐13 over a set of nine MMPs. To achieve optimal in vivo pharmacokinetics and tissue penetration, the probe has been further conjugated to a linear l ‐polyglutamate chain of 30 kDa. The conjugate detects early biochemical events that occur in a surgically induced murine model of OA before major histological changes. The nanometric probe is suitable for the monitoring of in vivo efficacy of an orally bioavailable MMP‐13 inhibitor, which effectively blocks cartilage degradation during the development of OA. This new polymer‐probe can therefore be a useful tool in detecting early OA, disease progression, and in developing MMP‐13‐based disease‐modifying drugs for OA.     

Reaching unanimous agreements within agent-based negotiation teams with linear and monotonic utility functions

In this article, an agent-based negotiation model for negotiation teams that negotiate a deal with an opponent is presented. Agent-based negotiation teams are groups of agents that join together as a single negotiation party because they share an interest that is related to the negotiation process. The model relies on a trusted mediator that coordinates and helps team members in the decisions that they have to take during the negotiation process: which offer is sent to the opponent, and whether the offers received from the opponent are accepted. The main strength of the proposed negotiation model is the fact that it guarantees unanimity within team decisions since decisions report a utility to team members that is greater than or equal to their aspiration levels at each negotiation round. This work analyzes how unanimous decisions are taken within the team and the robustness of the model against different types of manipulations. An empirical evaluation is also performed to study the impact of the different parameters of the model.     

Study of the cellular retention time and the partial biomass renovation in a fungal decolourisation continuous process

The long-term continuous decolourisation treatment of the textile dye Grey Lanaset G (150 mg/l) was carried out in an air-pulsed bed bioreactor with retained pellets of the white-rot fungus Trametes versicolor. Maximum cellular retention time (CRT) was established at 40 days. During this time period, colour reduction remained at 90% and laccase activity was over 400 AU/l. Higher CRTs involved operational problems related to biomass conglomerates formed at the top of the bioreactor, which made individual movement of the pellets difficult. In order to carry out the long-term continuous treatment, a strategy of purge and biomass renovation that had to allow fungal stable activity levels to be maintained was planned. The purge and biomass renovation strategy consists of partial biomass renovations: 1/3 of the total biomass of the system is renewed every 1/3 of the CRT. Different CRTs were tested; with a CRT of 21 days carrying out partial biomass renovations every 7 days and with a hydraulic retention time of 2 days, decolourisation percentages higher than 80% were obtained, maintaining a young culture in the bioreactor and guaranteeing microbial activity. In accordance with the strategy observed, different simulations of the age of the biomass in the bioreactor were carried out, obtaining suitable age distributions for CRT of 20-21 days.