14 research outputs found

    Simulation study on flexibilities in the material and energy flows of an open-pit mine

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    The progressing introduction of renewable energy sources (RES) in the energy system creates an increasingly difficult market environment for traditional utility companies. While their fossil-fuelled power plants are important to secure the supply of electricity, the associated operations are costly and energy intensive. This paper presents a simulation study on an open-pit mine (OPM), where flexibilities are sought for increasing the operator’s overall energy efficiency. For this purpose, the OPM’s material flows and energy flows are simulated simultaneously. Drawing from discrete production systems in a “cross-learning” approach possibilities for and adjustments to the process control are investigated. Preliminary results show that some opportunities to increase efficiency exist but still require more scrutiny

    Irreversible Antagonists for the Adenosine A2B Receptor

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    Blockade of the adenosine A2B receptor (A2BAR) represents a potential novel strategy for the immunotherapy of cancer. In the present study, we designed, synthesized, and characterized irreversible A2BAR antagonists based on an 8-p-sulfophenylxanthine scaffold. Irreversible binding was confirmed in radioligand binding and bioluminescence resonance energy transfer(BRET)-based Gα15 protein activation assays by performing ligand wash-out and kinetic experiments. p-(1-Propylxanthin-8-yl)benzene sulfonyl fluoride (6a, PSB-21500) was the most potent and selective irreversible A2BAR antagonist of the present series with an apparent Ki value of 10.6 nM at the human A2BAR and >38-fold selectivity versus the other AR subtypes. The corresponding 3-cyclopropyl-substituted xanthine derivative 6c (PSB-21502) was similarly potent, but was non-selective versus A1- and A2AARs. Attachment of a reactive sulfonyl fluoride group to an elongated xanthine 8-substituent (12, Ki 7.37 nM) resulted in a potent, selective, reversibly binding antagonist. Based on previous docking studies, the lysine residue K2697.32 was proposed to react with the covalent antagonists. However, the mutant K269L behaved similarly to the wildtype A2BAR, indicating that 6a and related irreversible A2BAR antagonists do not interact with K2697.32. The new irreversible A2BAR antagonists will be useful tools and have the potential to be further developed as therapeutic drugs

    Single Stabilizing Point Mutation Enables High‐Resolution Co‐Crystal Structures of the Adenosine A 2A Receptor with Preladenant Conjugates

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    The G protein‐coupled adenosine A(2A) receptor (A(2A)AR) is an important new (potential) drug target in immuno‐oncology, and for neurodegenerative diseases. Preladenant and its derivatives belong to the most potent A(2A)AR antagonists displaying exceptional selectivity. While crystal structures of the human A(2A)AR have been solved, mostly using the A(2A)‐StaR2 protein that bears 9 point mutations, co‐crystallization with Preladenant derivatives has so far been elusive. We developed a new A(2A)AR construct harboring a single point mutation (S91(3.39)K) which renders it extremely thermostable. This allowed the co‐crystallization of two novel Preladenant derivatives, the polyethylene glycol‐conjugated (PEGylated) PSB‐2113, and the fluorophore‐labeled PSB‐2115. The obtained crystal structures (2.25 Å and 2.6 Å resolution) provide explanations for the high potency and selectivity of Preladenant derivatives. They represent the first crystal structures of a GPCR in complex with PEG‐ and fluorophore‐conjugated ligands. The applied strategy is predicted to be applicable to further class A GPCRs

    GD2-targeted chimeric antigen receptor T cells prevent metastasis formation by elimination of breast cancer stem-like cells

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    Expression of the disialoganglioside GD2 has been identified as a marker antigen associated with a breast cancer stem-like cell (BCSC) phenotype. Here, we report on the evaluation of GD2 as a BCSC-specific target antigen for immunotherapy. GD2 expression was confirmed at variable degree in a set of breast cancer cell lines, predominantly in triple-negative breast cancer (TNBC). To target GD2, we have generated novel anti-GD2 chimeric antigen receptors (GD2-CAR), based on single-chain variable fragments (scFv) derived from the monoclonal antibody (mAb) ch14.18, also known as dinutuximab beta. Expressed on T cells, GD2-CARs mediated specific GD2-dependent T-cell activation and target cell lysis. In contrast to previously described GD2-CARs, no signs of exhaustion by tonic signaling were found. Importantly, application of GD2-CAR expressing T cells (GD2-CAR-T) in an orthotopic xenograft model of TNBC (MDA-MB-231) halted local tumor progression and completely prevented lung metastasis formation. In line with the BCSC model, GD2 expression was only found in a subpopulation (4-6%) of MDA-MB-231 cells before injection. Significant expansion of GD2-CAR-T in tumor-bearing mice as well as T-cell infiltrates in the primary tumor and the lungs were found, indicating site-specific activation of GD2-CAR-T. Our data strongly support previous findings of GD2 as a BCSC-associated antigen. GD2-targeted immunotherapies have been extensively studied in human. In conclusion, GD2-CAR-T should be considered a promising novel approach for GD2-positive breast cancer, especially to eliminate disseminated tumor cells and prevent metastasis formation
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