1,064 research outputs found
Reconstruction of Konrad Zuse’s Z3
No full textPart 9: Reconstruction StoriesInternational audienceThis paper describes the reconstruction of Konrad Zuse’s Machine Z3 by the author Horst Zuse from 2008. Konrad Zuse built the Z3 machine between 1939 and 1941 with some friends and a small amount of support by the government. The main idea for reconstructing the Z3 was to learn how this machine works and how much effort is necessary to build such a machine. Another main topic was to show this machine to the public
Author Correction: The dengue-specific immune response and antibody identification with machine learning
No full textCorrection to: npj Vaccineshttps://doi.org/10.1038/s41541-023-00788-7, published online 20 January 2024 In this article, the affiliation details for author Alexander Horst were incorrectly given as Alexander Horst1,2 but should have been Alexander Horst1 and other affiliations are renumbered. The original article has been corrected
Three manganese(II) coordination polymers with mixed donor ligands: synthesis, X-ray structures and luminescence properties
No full textThree new coordination polymers of manganese(II) of formulae [Mn3(phen)2(phdac)3]2H2O (1), [Mn(4,40-bipy)(H2O)4](cbprop)(2) and [Mn(2,20-bipy)(4-nph)(H2O)2]2 (3) (phen = 1,10-phenanthroline, 4,40-bipy = 4,40-bipyridine, 2,20-bipy = 2,20-bipyridine, H2phdac = 1,4-phenylenediacetic acid, H2cbprop = 4-carboxybenzenepropanoic acid and H2nph = 4-nitrophthalic acid) have been synthesized and structurally characterized by X-ray single-crystal diffraction analysis. The metal complexes possess 2D (1), 1D (2) and 0D (3) dimensionalities. In each case, the crystal packing shows three-dimensional architecture by means of p–p interactions and/or hydrogen bonding supported by coordinated and lattice water molecules. The emission spectra show metal-perturbed intra-ligand p*–p charge transfer transitions for 1 and p*–p and p*–n charge transfer transitions for 3
Three New Co-ordination Polymers of Zinc(II) and Cadmium(II) with Dicarboxylate and Bipyridine Ligands: Synthesis, Structure and Luminescence Study
No full textThree coordination polymers of zinc(II) and cadmium(II) of formula {[Zn(bipy)(NIPH)]0.15H2O}n(1), {[Cd2(bipy)2(NIPH)2]2H2O}n (2) and {[Cd2(bipy)4
(BDAC)(NO3)](NO3)6H2O}n (3) (NIPH = 5-nitro-isophthalic acid, H2BDAC = 1,4-benzenediacrylic acid and bipy = 2,20-bipyridine) have been synthesized and structurally characterized by X-ray single crystal diffraction analysis. All the complexes display 1D coordination polymers where M(bipy) units are connected by dicarboxylate anions(and also by nitrate in 3)acting as bridging ligands. While in 1 and 3 a zig–zag chain is generated, in case of 2 a double linear chain is formed by the two crystallographic distinct Cd atoms. In solid state all the complexes expand the dimensionality to 3D by means of p–p interactions among p rings and H-bonds generated by lattice water molecules. The fluorescence study indicates intraligand p–p* charge transfer is the reason for emission in all the complexes
1D lead(II) coordination chains with carboxylate containing ligands. A rare example of polyrotaxane 1D → 1D interpenetrated coordination polymer
No full textThe structural determination of twointeresting lead(II) coordination polymers, namely [Pb(ind)2(H2O)]n (1) and
[Pb2(dbsf)2(bipy)]n (2) (Hind = indane-2-carboxylic acid, H2dbsf= 4,4′-sulfonyldibenzoic acid, and bipy 4,4′-
bipyridine), reveals in the second an unexpected polyrotaxane 1D → 1D interpenetrated coordination polymer
thanks to the hemidirected coordination geometry of the metal and the rings formed by the dicarboxybiphenyl
sulfone ligands along the 1D chain
Horst Wessel Dachau Street Sign
No full textBlack metal sign reading, 24 Horst Wessel-Strasse.
Information Provided by Michael D. Bulmash: A small metal street sign from the concentration camp of Dachau. The streets in Dachau were named after so-called Nazi heroes, and this particular example identifies the address 24 Horst Wessel Strasse. Horst Ludwig Wessel (1907-1930) was a German Nazi activist who was made a posthumous hero of the Nazi movement following his violent death in 1940. He was the author of the lyrics to the Nazi Party anthem Die Fahnehoch ( The Flag on High ), usually known as the Horst Wessel Song.https://digital.kenyon.edu/bulmash/2251/thumbnail.jp
Electrical conductivity and luminescence properties of two silver(I) coordination polymers with heterocyclic nitrogen ligands
No full textThe synthesis and X-raystructural characterization of two novel silver(I) coordination polymers, [Ag
(NO3)(quin)]n (1) and[Ag8(HL)2(H2O)4(mpyz)] . 3H2O (2) arereported, wherequin= 5,6,7,8-tetrahydro-
quinoxaline, H6L = cyclohexane-1,2,3,4,5,6-hexacarboxylic acid andmpyz = 2-methylpyrazine.The single
crystal diffractionan alyses showed that complex 1 is a 2D layered structure, while 2 presents a 3D
polymeric architecture .In complex 2 the network is stabilized by argentophilic interactions and
hydrogen bonding. Electrical conductivity of order 3x10-4 S cm-1 (1) and1.6x10-4 S cm-1 (2) is
measured on thin film specimen at room temperature.The photoluminescence and thermal properties
of the complexes have also been studied
DNA/Protein Binding, Molecular Docking and Cytotoxicity Studies of Piperazinyl-Moiety-Based Copper(II) Complexes
No full textCopper(II) complexes {[Cu(HL)(ClO4)(H2O)](ClO4)⋅3H2O} (1), {[Cu
(HL)(m-phth)]⋅5H2O} (2) and {[Cu(HL)(NCS)]2(ClO4)2⋅2H2O} (3)
(HL=2-{[2-(1-piperazinyl)ethylimino]methyl}phenol; m-phth=
1,3-benzenedicarboxylate] have been synthesized and characterized
by structural determination and spectroscopic studies.
The mononuclear square pyramidal complex 1 resulted from
the reaction of HL with copper perchlorate hexahydrate. Then
mononuclear square planar complex 2 and dinuclear thiocyanato
bridged complex 3 were obtained by reacting 1 with
disodium 1,3-benzenedicarboxylate (Na2(m-phth)) and potassium
thiocyanate, respectively. The interactions of 1–3 with CTDNA
/ serum albumins were investigated by UV-visible
absorption and fluorescence spectroscopy. The intrinsic binding
constants of 1, 2 and 3 with CT-DNA were calculated. Study of the interactions of 1–3 with
human serum albumin (HSA) / bovine serum albumin (BSA)
showed that all the complexes could quench intrinsic
fluorescence of HSA and BSA through a static quenching
process. Molecular docking technique was utilised to confirm
the mode of interaction of complexes with CT-DNA / serum
albumin. Anticancer activities of the complexes have been
tested using human breast cancer cell lines MCF7 and MBAMB-
231. Among the complexes studied 3 shows the higher
cytotoxic activity and growth inhibition of cancer cells via
induction of apoptotic cell death
A full-Stokes polarimeter for the GREGOR Fabry-Perot interferometer
No full textOne of the first post-focus instruments of the new solar telescope GREGOR will be a Fabry-Perot spectrometer, which is an upgrade of the G¨ottingen Fabry-Perot interferometer at the Vacuum Tower Telescope (VTT) on Tenerife. This spectrometer is equipped with a full-Stokes polarimeter. The modulation is performed with two ferroelectric liquid crystals, one acting nominally as quarter-wave plate, and the other as half-wave plate. A modified Savart plate serves as polarimetric beam splitter. With the present liquid crystals, the optimum wavelength range of this polarimeter is between 580 and 660 nm. The spectro-polarimeter will benefit from the capabilities of the new telescope GREGOR which will provide a spatial resolution of about 0 . 1 (75 km on the solar surface). Thus we will be able to investigate small magnetic features, and we will study their development with high cadence
Trimerisation of carbon suboxide at a di-titanium centre to form a pyrone ring system
No full textThe reaction of the syn-bimetallic bis(pentalene)dititanium complex Ti2(μ:η5,η5-Pn†)2 (Pn† = C8H4(1,4-SiiPr3)2) 1 with carbon suboxide (OCCCO, C3O2) results in trimerisation of the latter and formation of the structurally characterised complex [{Ti2(μ:η5,η5-Pn†)2}{μ-C9O6}]. The trimeric bridging C9O6 unit in the latter contains a 4-pyrone core, a key feature of both the hexamer and octamer of carbon suboxide which are formed in the body from trace amounts of C3O2 and are, for example, potent inhibitors of Na+/K+-ATP-ase. The mechanism of this reaction has been studied in detail by DFT computational studies, which also suggest that the reaction proceeds via the initial formation of a mono-adduct of 1 with C3O2. Indeed, the carefully controlled reaction of 1 with C3O2 affords [Ti2(μ:η5,η5-Pn†)2 (η2-C3O2)], as the first structurally authenticated complex of carbon suboxide.</p
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