647 research outputs found
Introduction to Lattices and Its Applications in Compute-and-Forward Strategy
The Compute-and-Forward (CF) strategy was proposed as a physical layer network coding (PNC) framework by Nazer and Gastpar in 2011. CF exploits interference to obtain higher rates between users in a network. This thesis focuses on studying the application of the lattice network coding (LNC) for CF strategy using maximum-likelihood (ML) decoding through four influential papers in the area.Masteroppgave i informatikkINF399MAMN-PROGMAMN-IN
Market Monitor: Development of the Wholesale Electricity Market in 2006
Competition in the Dutch electricity market is stagnating. The market remains concentrated, with relatively high prices. The north-west European market must be further integrated by expanding the available interconnection capacity in order to achieve a structural improvement. That could cut consumers’ annual energy bills by several dozen euros per household. Consumers would also benefit indirectly since electricity prices for business would also fall, putting downward pressure on prices of other products. In order to achieve these benefits for consumers, the TSO’s must make headway with the expansion of the available interconnection capacity.Monitoring, electricity, competition, infrastructure
Intermolecular C-H activation with an Ir-METAMORPhos piano-stool complex: multiple reaction steps at a reactive ligand
Substrate activation by means of a reactive ligand is a topic of much interest. Herein we describe a stoichiometric anti-Markovnikov C-N bond formation involving ligand reactivity in multiple steps along the reaction coordinate, including ligand assisted substrate (de)protonation and C-N bond formation, as illustrated by a combined experimental, spectroscopic and computational study. This affords a highly unusual four-membered iridacycle bearing an exo-cyclic C=C double bond
Clinical consequences of antibody formation, serum concentrations, and HLA-Cw6 status in psoriasis patients on Ustekinumab
Background: Ustekinumab for the treatment of psoriasis is currently administered in a standard dosing regimen. However, some patients tend to benefit from alternative dosing regimens, a step toward personalized medicine. Methods: To investigate the role of ustekinumab serum concentrations, anti-ustekinumab antibodies [AUA] and HLA-Cw6 status as tools for optimizing ustekinumab treatment, a multicenter prospective cohort study was conducted at an academic hospital with affiliated nonacademic hospitals in Belgium (cohort 1) and 2 academic hospitals in the Netherlands (cohort 2 and 3). Patients with plaque-type psoriasis were eligible if treated with ustekinumab for >16 weeks. Serum samples and Psoriasis Area and Severity Index scores were obtained at baseline, week 16, 28, 40, 52, and/or >64 of ustekinumab treatment. Results: A total of 137 patients with 229 observations for serum concentrations and AUA and 61 observations for HLA-Cw6 status were included. Presence of AUA (prevalence of 8.7%) was significantly associated with a diminished clinical response (P = 0.032). The median ustekinumab trough concentration was 0.3 mcg/mL (<0.02-3.80). No differences in serum concentrations were observed between moderate to good responders and nonresponders (P = 0.948). Serum trough concentrations were not affected by methotrexate comedication. Prevalence of HLA-Cw6 positivity was 41% with no statistically significant difference in clinical response between HLA-Cw6-positive and HLA-Cw6-negative patients (P = 0.164). Conclusions: The presence of AUA was associated with treatment failure in this patient population; measurement of AUA may therefore be a candidate marker for personalized pharmacotherapy. The clinical utility of ustekinumab serum trough concentrations or HLA-Cw6 status determination remains less clear. Further exploration on the potential of measuring ustekinumab serum concentrations and other biomarkers in predicting therapy outcomes should be encouraged
Titanium-catalyzed esterification reactions: beyond Lewis acidity
Esterification is a key reaction and is used in many synthetic and industrial processes, yet the detailed mechanism of operation of often-used (Lewis acid) catalysts is unknown and subject of little research. Here, we report on mechanistic studies of a titanium aminotriphenolate catalyst, using stoichiometric and catalytic reactions combined with kinetic data and density functional theory (DFT) calculations. While often only the Lewis acidity of the Ti-center is taken into account, we found that the amphoteric nature of this catalyst, combining this Lewis acidity with Brønsted basicity of a Ti-bound and in situ formed carboxylate group, is crucial for catalytic activity. Furthermore, hydrogen bonding interactions are essential to pre-organize substrates and to stabilize various intermediates and transition states and thus enhancing the overall catalytic reaction. These findings are not only applicable to this class of catalysts, but could be important for many other esterification catalysts
Combinatorial strategies to find new catalysts for asymmetric hydrogenation based on the versatile coordination chemistry of METAMORPhos ligands
To extend the toolbox and find improved catalysts, anionic METAMORPhos ligands and neutral amino-acid-based ligands were used separately and in mixtures to form Rh complexes used in the asymmetric hydrogenation of eight industrially relevant substrates. Spectroscopic studies showed that under the catalytic conditions, the mononuclear complex with two different ligands (the heterocombination) is the main complex in solution if both the anionic and neutral ligands have the same chirality. If the neutral ligand and the anionic ligand have the opposite chirality at the P atom, monometallic and bimetallic heterocomplexes were detected by NMR spectroscopy and MS. For the majority of substrates evaluated in this study, higher enantioselectivities were obtained if the complexes used were based on the heterocombination of an anionic and a neutral ligand compared to respective homocombinations. After we found the initial leads, higher turnover numbers and enantioselectivities could be obtained easily by further exploring focused ligand libraries. The superior activity of the complexes based on the different ligands is highlighted by their robustness: significant divergence from a 1:1 ratio between the ligands does not lower the selectivity of the catalyst, although more of the competing homocomplexes are formed under these conditions
3-Methylindole-Based Tripodal Tetraphosphine Ruthenium Complexes in N<sub>2 </sub>Coordination and Reduction and Formic Acid Dehydrogenation
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