This paper refines the nature of the interactions between electron-deficient arenes and halide anions. Conclusions are based on (i) new crystal structures containing alkali halide salts with 1,2,4,5-tetracyanobenzene (TCB) and 18-crown-6, (ii) evaluation of crystal structures found in the Cambridge Structural Database, and (iii) MP2/aug-cc-pVDZ calculations of F-, Cl-, and Br- complexes with TCB, 1,3,5-tricyanobenzene, triazine, and hexafluorobenzene. When the halide lies above the plane of the π system, the results establish that three distinctly different types of complexes are possible: strongly covalent σ complexes, weakly covalent donor−π-acceptor complexes, and noncovalent anion−π complexes. When aryl C−H groups are present, a fourth type of interaction leads to C−H · · · X- hydrogen bonding. Characterization of the different geometries encountered with the four possible binding motifs provides criteria needed to design host architectures containing electron-deficient arenes.
The lung is, more than other solid organs, susceptible for ischemia reperfusion injury after orthotopic transplantation. Corticosteroids are known to potently suppress pro-inflammatory processes when given in the post-operative setting or during rejection episodes. Whereas their use has been approved for these clinical indications, there is no study investigating its potential as a preservation additive in preventing vascular damage already in the phase of ischemia. To investigate these effects we performed orthotopic lung transplantations (LTX) in the rat. Prednisolone was either added to the perfusion solution for lung preservation or omitted and rats were followed for 48 hours after LTX. Prednisolone preconditioning significantly increased survival and diminished reperfusion edema. Hypoxia induced vasoactive cytokines such as VEGF were reduced. Markers of leukocyte invasiveness like matrix metalloprotease (MMP)-2, or common pro-inflammatory molecules like the CXCR4 receptor or the chemokine (C-C motif) ligand (CCL)-2 were downregulated by prednisolone. Neutrophil recruitment to the grafts was only increased in Perfadex treated lungs. Together with this, prednisolone treated animals displayed significantly reduced lung protein levels of neutrophil chemoattractants like CINC-1, CINC-2α/β and LIX and upregulated tissue inhibitor of matrix metalloproteinase (TIMP)-1. Interestingly, lung macrophage invasion was increased in both, Perfadex and prednisolone treated grafts, as measured by MMP-12 or RM4. Markers of anti-inflammatory macrophage transdifferentiation like MRC-1, IL-13, IL-4 and CD163, significantly correlated with prednisolone treatment. These observations lead to the conclusion that prednisolone as an additive to the perfusion solution protects from hypoxia triggered danger signals already in the phase of ischemia and thus reduces graft edema in the phase of reperfusion. Additionally, prednisolone preconditioning might also lead to macrophage polarization as a beneficial long-term effect.
A series of anionically functionalized polyfluorene-based conjugated polyelectrolytes were synthesized by the Suzuki polycondensation of the boronic ester 2,7-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9,9-di(1-(2-(2-methoxyethoxy)ethoxy)ethyl)fluorene with the ionic and nonionic dihalides 2,7-dibromo-9,9-di(6-sodium sulfonate-hexyl)fluorene and 2,7-dibromo-9,9-di(1-(2-(2-methoxyethoxy)ethoxy)ethyl)fluorene. The latter monomer served as a diluent to control the ionic functional group density. The use of the triethylene glycol monomethyl ether derivatives made possible a one-phase polycondensation in a THF/methanol/Na2CO3(aq) mixture using Pd(PPh3)4. The one-phase nature of the polymerization was essential to balancing the reactivity of the dihalides so that they were both incorporated into the same polymer and so that the polymer composition became dictated by the monomer feedstock composition. In closely related two-phase reactions, a mixture of polymers, one ionic and one nonionic, was isolated with no control over ionic functional group density possible. Using the one-phase approach, polyfluorene-based polyelectrolytes were synthesized with 2–20 aromatic rings per sulfonate group.
<b><i>Introduction:</i></b> Urolithiasis is a common disease leading to a high socioeconomic burden due to treatment costs and sickness leave. The aim of this study was to evaluate recent trends in the incidence of urolithiasis in Germany and in the use of therapeutic interventions. <b><i>Methods:</i></b> Treatment data for all in-patient hospital episodes for urolithiasis between 2005 and 2016 were extracted from the national DRG statistics at DESTATIS and analysed with regard to the corresponding procedures according to the OPS code. <b><i>Results:</i></b> Incidence for urolithiasis was stable at around 120,000 cases per year during the observation period with a male:female ratio of 2:1. Rising numbers were noted for patients >80 years. Nevertheless, the number of coded procedures rose significantly with a marked disproportionate transition from extracorporeal shock wave lithotripsy towards ureterorenoscopy. Percutaneous nephrolithotomy was performed more frequently on a smaller scale. <b><i>Discussion/Conclusion:</i></b> While the global incidence of urolithiasis is still rising, Germany, as other Western countries, has reached a plateau. There is a remarkable trend towards invasive treatment of even asymptomatic kidney stones. Besides the effects on individual patients with increased risk for complications, this results in a higher monetary burden to the health care system and society.
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