Protocol of a population-based prospective COVID-19 cohort study Munich, Germany (KoCo19)

Background: Due to the SARS-CoV-2 pandemic, public health interventions have been introduced globally in order to prevent the spread of the virus and avoid the overload of health care systems, especially for the most severely affected patients. Scientific studies to date have focused primarily on describing the clinical course of patients, identifying treatment options and developing vaccines. In Germany, as in many other regions, current tests for SARS-CoV2 are not conducted on a representative basis and in a longitudinal design. Furthermore, knowledge about the immune status of the population is lacking. Nonetheless, these data are needed to understand the dynamics of the pandemic and hence to appropriately design and evaluate interventions. For this purpose, we recently started a prospective population-based cohort in Munich, Germany, with the aim to develop a better understanding of the state and dynamics of the pandemic. Methods: In 100 out of 755 randomly selected constituencies, 3000 Munich households are identified via random route and offered enrollment into the study. All household members are asked to complete a baseline questionnaire and subjects ≥14 years of age are asked to provide a venous blood sample of ≤3 ml for the determination of SARS-CoV-2 IgG/IgA status. The residual plasma and the blood pellet are preserved for later genetic and molecular biological investigations. For twelve months, each household member is asked to keep a diary of daily symptoms, whereabouts and contacts via WebApp. If symptoms suggestive for COVID-19 are reported, family members, including children < 14 years, are offered a pharyngeal swab taken at the Division of Infectious Diseases and Tropical Medicine, LMU University Hospital Munich, for molecular testing for SARS-CoV-2. In case of severe symptoms, participants will be transferred to a Munich hospital. For one year, the study teams re-visits the households for blood sampling every six weeks. Discussion: With the planned study we will establish a reliable epidemiological tool to improve the understanding of the spread of SARS-CoV-2 and to better assess the effectiveness of public health measures as well as their socio-economic effects. This will support policy makers in managing the epidemic based on scientific evidence

Wikibase as an Infrastructure for Knowledge Graphs: The EU Knowledge Graph

info:eu-repo/semantics/publishe

Wikibase as an Infrastructure for Knowledge Graphs: the EU Knowledge Graph

International audienceKnowledge graphs are being deployed in many enterprises and institutions. An easy-to-use, well-designed infrastructure for such knowledge graphs is not obvious. After the success of Wikidata, many institutions are looking at the software infrastructure behind it, namely Wikibase. In this paper we introduce Wikibase, describe its different software components and the tools that have emerged around it. In particular, we detail how Wikibase is used as the infrastructure behind the "EU Knowledge Graph", which is deployed at the European Commission. This graph mainly integrates projects funded by the European Union, and is used to make these projects visible to and easily accessible by citizens with no technical background. Moreover, we explain how this deployment compares to a more classical approach to building RDF knowledge graphs, and point to other projects that are using Wikibase as an underlying infrastructure

Electrical Sensing of Phosphonates by Functional Coupling of Phosphonate Binding Protein PhnD to Solid-State Nanopores.

Combining the stability of solid-state nanopores with the unique sensing properties of biological components in a miniaturized electrical hybrid nanopore device is a challenging approach to advance the sensitivity and selectivity of small-molecule detection in healthcare and environment analytics. Here, we demonstrate a simple method to design an electrical hybrid nanosensor comprising a bacterial binding protein tethered to a solid-state nanopore allowing high-affinity detection of phosphonates. The diverse family of bacterial substrate-binding proteins (SBPs) binds specifically and efficiently to various substances and has been implicated as an ideal biorecognition element for analyte detection in the design of hybrid bionanosensors. Here, we demonstrate that the coupling of the purified phosphonate binding protein PhnD via primary amines to the reactive NHS groups of P(DMAA--NMAS) polymers inside a single track-etched nanopore in poly(ethylene terephthalate) (PET) foils results in ligand-specific and concentration-dependent changes in the nanopore current. Application of the phosphonate 2-aminoethylphosphonate (2AEP) or ethylphosphonate (EP) induces a large conformational rearrangement in PnhD around the hinge in a venus flytrap mechanism resulting in a concentration depended on increase of the single pore current with binding affinities of 27 and 373 nM, respectively. Thus, the specificity and stability of this simple hybrid sensor concept combine the advantages of both, the diversity of ligand-specific substrate-binding proteins and solid-state nanopores encouraging further options to produce robust devices amenable to medical or environmental high-throughput-based applications in nanotechnology

(N,Se) and (Se,N,Se) ligands based on carborane and pyridine fragments – reactivity of 2,6-[(1′-Me-1′,2′-closo-C2B10H10)SeCH2]2C5H3N towards Copper and silver

Two new closo-carborane selenolated ligands, 2-[(1′-Me-1′,2′-closo-CBH)SeCH]CHN (L) and 2,6-[(1′-Me-1′,2′-closo-CBH)SeCH]CHN (L), were prepared by the C–H activation of 1-Me-1,2-CBH with nBuLi, followed by the insertion of elemental selenium into the C–Li bond and reaction with 2-(BrCH)CHN or 2,6-(BrCH)CHN, respectively. The closo species L and L were deboronated with CsF to give the nido-carborane cesium salts Cs[2-{(1′-Me-1′,2′-nido-CBH)SeCH}CHN] (1) and Cs[2,6-{(1′-Me-1′,2′-nido-CBH)SeCH}CHN] (2). The isolation of the complexes [Ag(OTf)(L)] (3, OTf = triflate), [Ag(PPh)(L)][OTf] (4), [Cu(L)(MeCN)][PF] (5), and [Cu(L)][PF] (6) indicates the coordination ability of L towards these metals. The molecular structures of L and L were established by single-crystal X-ray diffraction. Quantum-chemical calculations confirmed the molecular geometries and also the presence of C–H···Se intramolecular interactions as well as C–H···H–B and B–H···π intermolecular interactions.This work was supported by the National University Research Council of Romania CNCSIS (grants TD66/2007 and PN-II-ID-PCCE-2011-2-0050/Partener 3) and MINECO-FEDER (CTQ2016-75816-C2-1-P).Peer Reviewe

Another Torture Track for Quantum Chemistry: Reinvestigation of the Benzaldehyde Amidation by Nitrogen‐Atom Transfer from Platinum(II) and Palladium(II) Metallonitrenes

We showcase here a dramatic failure of CCSD(T) theory that originates from the pronounced multi‐reference character of a key intermediate formed in the benzaldehyde amidation by N‐atom transfer from Pd(II) and Pt(II) metallonitrenes studied recently in combined experimental and theoretical work. For detailed analysis we devised a minimal model system, for which we established reliable reference energies based on approximate full configuration interaction theory, to assess the performance of single‐reference coupled‐cluster theory up to the CCSDTQ(P) excitation level. While RHF‐based CCSD(T) theory suffered dramatic errors, in one case exceeding 220 kcal mol−1, we show that the use of broken‐symmetry (BS) or Kohn‐Sham (KS) orbital references yields substantially improved CCSD(T) results. Further, the EOM‐SF‐CCSD(T)(a)* approach met the reference data with excellent accuracy. We applied the KS‐CCSD(T*)‐F12b variant as high‐level part of an ONIOM(KS‐CC:DFT) scheme to reinvestigate the reactivity of the full Pt(II) and Pd(II) metallonitrenes. The revised reaction pathway energetics provide a detailed mechanistic rationale for the experimental observations.Deutsche Forschungsgemeinschaft (DFG)Deutsche Forschungsgemeinschaft (DFG)TRR 146Peer Reviewe

Another Torture Track for Quantum Chemistry: Reinvestigation of the Benzaldehyde Amidation by Nitrogen‐Atom Transfer from Platinum(II) and Palladium(II) Metallonitrenes

We showcase here a dramatic failure of CCSD(T) theory that originates from the pronounced multi‐reference character of a key intermediate formed in the benzaldehyde amidation by N‐atom transfer from Pd(II) and Pt(II) metallonitrenes studied recently in combined experimental and theoretical work. For detailed analysis we devised a minimal model system, for which we established reliable reference energies based on approximate full configuration interaction theory, to assess the performance of single‐reference coupled‐cluster theory up to the CCSDTQ(P) excitation level. While RHF‐based CCSD(T) theory suffered dramatic errors, in one case exceeding 220 kcal mol⁻¹, we show that the use of broken‐symmetry (BS) or Kohn‐Sham (KS) orbital references yields substantially improved CCSD(T) results. Further, the EOM‐SF‐CCSD(T)(a)* approach met the reference data with excellent accuracy. We applied the KS‐CCSD(T*)‐F12b variant as high‐level part of an ONIOM(KS‐CC:DFT) scheme to reinvestigate the reactivity of the full Pt(II) and Pd(II) metallonitrenes. The revised reaction pathway energetics provide a detailed mechanistic rationale for the experimental observations

A Platinum(II) Metallonitrene with a Triplet Ground State

Metallonitrenes (M–N) are complexes with a subvalent, atomic nitrogen ligand that have been proposed as key reactive intermediates in nitrogen atom transfer reactions. However, in contrast to the common class of nitride complexes (Mo≡N) and organic nitrenes (R–N), authentic, persistent metallonitrenes remain elusive. We here report that the photolysis of a platinum(II) pincer azide complex enabled the crystallographic, spectroscopic, magnetic and computational characterization of a metallonitrene that is best described as a singly bonded, atomic nitrogen diradical ligand bound to platinum(II). The photoproduct exhibits selective C–H, B–H, and B–C nitrogen atom insertion reactivity. Mechanistic examination of aldehyde C–H amidation surprisingly reveals nucleophilic reactivity of the subvalent N-diradical ligand.</div

A Preorganized Ditopic Borane as Highly Efficient One- or Two-Electron Trap

Reduction of the bis­(9-borafluorenyl)­methane <b>1</b> with excess lithium furnishes the red dianion salt Li₂[<b>1</b>]. The corresponding dark green monoanion radical Li­[<b>1</b>] is accessible through the comproportionation reaction between <b>1</b> and Li₂[<b>1</b>]. EPR spectroscopy on Li­[<b>1</b>] reveals hyperfine coupling of the unpaired electron to two magnetically equivalent boron nuclei (<i>a</i>(¹¹B) = 5.1 ± 0.1 G, <i>a</i>(¹⁰B) = 1.7 ± 0.2 G). Further coupling is observed to the unique B–C<i>H</i>–B bridgehead proton (<i>a</i>(¹H) = 7.2 ± 0.2 G) and to eight aromatic protons (<i>a</i>(¹H) = 1.4 ± 0.1 G). According to X-ray crystallography, the B···B distances continuously decrease along the sequence <b>1</b> → [<b>1</b>]^•– → [<b>1</b>]^2– with values of 2.534(2), 2.166(4), and 1.906(3) Å, respectively. Protonation of Li₂[<b>1</b>] leads to the cyclic borohydride species Li­[<b>1H</b>] featuring a B–H–B two-electron-three-center bond. This result strongly indicates a nucleophilic character of the boron atoms; the reaction can also be viewed as rare example of the protonation of an element–element σ bond. According to NMR spectroscopy, EPR spectroscopy, and quantum-chemical calculations, [<b>1</b>]^2– represents a closed-shell singlet without any spin contamination. Detailed wave function analyses of [<b>1</b>]^•– and [<b>1</b>]^2– reveal strongly localized interactions of the two boron p_<i>z</i>-type orbitals, with small delocalized contributions of the 9-borafluorenyl π systems. Overall, our results provide evidence for a direct B–B one-electron and two-electron bonding interaction in [<b>1</b>]^•– and [<b>1</b>]^2–, respectively

Insight into the Oriented Growth of Surface-Attached Metal–Organic Frameworks: Surface Functionality, Deposition Temperature, and First Layer Order

The layer-by-layer growth of a surface-attached metal–organic framework (SURMOF), [Cu₂­(F₄bdc)₂­(dabco)] (F₄bdc = tetrafluorobenzene-1,4-dicarboxylate and dabco = 1,4-diazabicyclo-[2.2.2]­octane), on carboxylate- and pyridine-terminated surfaces has been investigated by various surface characterization techniques. Particular attention was paid to the dependency of the crystal orientation and morphology on surface functionality, deposition temperature, and first layer order. For the fully oriented deposition of SURMOFs, not only a suitable surface chemistry but also the appropriate temperature has to be chosen. In the case of carboxylate-terminated surfaces, the expected [100] oriented [Cu₂(F₄bdc)₂(dabco)] SURMOF can be achieved at low temperatures (5 °C). In contrast, the predicted [001] oriented SURMOF on pyridine-terminated surface was obtained only at high deposition temperatures (60 °C). Interestingly, we found that rearrangement processes in the very first layer determine the final orientation (distribution) of the growing crystals. These effects could be explained by a surprisingly hampered substitution at the apical position of the Cu₂-paddle wheel units, which requires significant thermal activation, as supported by quantum-chemical calculations