Solving a k-Node Minimum Label Spanning Arborescence Problem to Compress Fingerprint Templates

We present a novel approach for compressing relatively small unordered data sets by means of combinatorial optimization. The application background comes from the field of biometrics, where the embedding of fingerprint template data into images by means of watermarking techniques requires extraordinary compression techniques. The approach is based on the construction of a directed tree, covering a sufficient subset of the data points. The arcs are stored via referencing a dictionary, which contains “typical” arcs w.r.t. the particular tree solution. By solving a tree-based combinatorial optimization problem we are able to find a compact representation of the input data. As optimization method we use on the one hand an exact branch-and-cut approach, and on the other hand heuristics including a greedy randomized adaptive search procedure (GRASP) and a memetic algorithm. Experimental results show that our method is able to achieve higher compression rates for fingerprint (minutiae) data than several standard compression algorithms.     

Mott-Hubbard transition versus Anderson localization in correlated electron systems with disorder

The phase diagram of correlated, disordered electron systems is calculated within dynamical mean-field theory using the geometrically averaged ("typical") local density of states. Correlated metal, Mott insulator, and Anderson insulator phases, as well as coexistence and crossover regimes, are identified. The Mott and Anderson insulators are found to be continuously connected.     

Radical cube zero selfinjective algebras of finite complexity

One of our main results is a classification of all the possible quivers of selfinjective radical cube zero finite-dimensional algebras over an algebraically closed field having finite complexity. In the paper (Erdmann and Solberg, 2011) [5] we classified all weakly symmetric algebras with support varieties via Hochschild cohomology satisfying Dade’s Lemma. For a finite-dimensional algebra to have such a theory of support varieties implies that the algebra has finite complexity. Hence this paper is a partial extension of [5].     

Substrate-Enabled Room-Temperature Electrochemical Deposition of Crystalline ZnMnO3

Mixed transition metal oxides have emerged as promising electrode materials for electrochemical energy storage and conversion. To optimize the functional electrode properties, synthesis approaches allowing for a systematic tailoring of the materials’ composition, crystal structure and morphology are urgently needed. Here we report on the room-temperature electrodeposition of a ternary oxide based on earth-abundant metals, specifically, the defective cubic spinel ZnMnO₃. In this unprecedented approach, ZnO surfaces act as (i) electron source for the interfacial reduction of MnO₄⁻ in aqueous solution, (ii) as substrate for epitaxial growth of the deposit and (iii) as Zn precursor for the formation of ZnMnO₃. Epitaxial growth of ZnMnO₃ on the lateral facets of ZnO nanowires assures effective electronic communication between the electroactive material and the conducting scaffold and gives rise to a pronounced 2-dimensional morphology of the electrodeposit forming – after partial delamination from the substrate – twisted nanosheets. The synthesis strategy shows promise for the direct growth of different mixed transition metal oxides as electroactive phase onto conductive substrates and thus for the fabrication of binder-free nanocomposite electrodes.     

Photoaktivierte selective hydrierung von butindiol zu butendiol mit dem katalysator IrCl(CO)(PPh3)2

Under a weak UV irradiation butynediol is selectively hydrogenated to butenediol with IrCl(CO)(PPh₃)₂ as the catalyst in toluene/trifluroethanol ($\text{1}\text{1}$) at 60 °C.     

Polysulfonylamine. LXXXIV [1]. Zur Isotypie in den Dimesylamid-Komplexreihen [M(H2O)4{(CH3SO2)2N}2] (MMg,Ca, Ni,Cu, Zn,Cd) und [M(py)4{(CH3SO2)2N}2] (MNi,Cu, Zn,Cd)

Polysulfonylamines. LXXXIV. Isotypic Structures in the Dimesylamide Complex Series [M(H₂O)₄{(CH₃SO₂)₂N}₂] (M?Mg, Ca, Ni, Cu, Zn, Cd) and [M(py)₄{(CH₃SO₂)₂N}₂] (M?Ni, Cu, Zn, Cd) The crystal structures of the trans-octahedral complexes [M(H₂O)₄{(CH₃SO₂)₂N}₂] (M?Ca, Cd), in which the dimesylamide anion acts as a monodentate O-ligand and a tetrafunctional hydrogen bond acceptor, were determined by low-temperature X-ray diffraction. Both belong to an isotypic series (triclinic, space group P1 , Z = 1) that had previously been characterized for M?Mg, Ni, Cu and Zn (Z. Anorg. Allg. Chem. 1996 , 622, 1065). In this structure there exists an extended network of strong hydrogen bonds which is probably the underlying reason why the structure type surprisingly persists across the whole series. To support this explanation by indirect evidence from comparison with suitable structures devoid of strong hydrogen bonding, the analogous trans-octahedral complexes [M(py)₄{(CH₃SO₂)₂N}₂] (M?Mn, Co, Ni, Cu, Zn, Cd) were prepared by treating M[(CH₃SO₂)₂N]₂ with pyridine, and the crystal structures of the Ni, Cu, Zn and Cd compounds were studied by low-temperature X-ray crystallography. As anticipated, the four pyridine complexes do not form an isotypic series but instead two isotypic pairs consisting of the Ni and Zn compounds (monoclinic, space group P2₁/n, Z =2) and of the Cu and Cd complexes (triclinic, space group P1, Z = 1). All molecules of the aqua and the pyridine complexes display crystallographic centrosymmetry. In the hydrates, the mean M? OH₂ and the M? O(anion) distances are 232.6 and 232.7 pm for M ? Ca, 225.5 and 230.3 pm für M ? Cd. The mean M? N and the M? O(anion) bond lengths of the pyridine species amount to 211.8 and 213.1 pm for M ? Ni, 217.0 and 218.5 pm for M ? Zn, 232.8 and 234.4 pm for M ? Cd; the corresponding values for the severely Jahn-Teller distorted Cu complex are 203.6 and 254.5 pm. In the crystals of the pyridine complexes, each methyl group is connected through a weak C? H…?O bond to a sulfonyl oxygen atom of an adjacent molecule.     

Thiohalogeno-Verbindungen von Niob und Tantal: NbSCl3, TaSCl3, [NbSCl5]2−, [TaSCl5]2−, [NbSBr4]− Die Kristallstrukturen von (PPh4)2[NbSCl5] · 2 CH2Cl2 und NEt4[NbCl6]

Thiohalo Compounds of Niobium and Tantalum: NbSCl₃, TaSCl₃, [NbSCl₅]^2?, [TaSCl₅]^2?, [NbSBr₄]^?. Crystal Structures of (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ and NEt₄[NbCl₆] NbSCl₃ can be obtained from NbCl₅ by reaction with H₂S or bistrimethylsilyl sulfide in a suspension of CCl₄ or CH₂Cl₂, respectively; in the latter case the product contains a rest of trimethylsilyl groups. This also applies for TaSCl₃, NbSBr₃ and TaSBr₃, which are formed from the metal pentahalides and S(SiMe₃)₂. NEt₄[NbSCl₄] is formed together with NEt₄[NbCl₆] in the reaction of NbCl₅ with NEt₄SH in CH₂Cl₂. PPh₄[NbCl₆] reacts with S(SiMe₃)₂ in dichloromethane yielding (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂, whereas PPh₄[NbSBr₄] is obtained from PPh₄[NbBr₆] and S(SiMe₃) under the same conditions. (PPh₄)₂[TaSCl₅] · 2 CH₂Cl₂ was obtained from TaSCl₃ and PPh₄Cl in CH₂Cl₂. According to an X-ray crystal structure determination (PPh₄)₂[NbSCl₅] · 2 CH₂Cl₂ crystallizes in the β-(AsPh₄)₂[UCl₆] · 2 CH₂Cl₂ type with positionally disordered, octahedral anions. Crystal data: a = 1 021.7, b = 1120.4, c = 1 243.3 pm, α = 70.77, β = 80.24, γ = 80.54°, space group P1 , Z = 2; 2462 unique observed reflexions, R = 0.036. NEt₄[NbCl₆] crystallizes isotypic to NEt₄[WCl₆], a = 723.5, b = 1 018.0, c = 1 174.6 pm, β = 100.07°, space group P2₁/n, Z = 2; 1 875 reflexions, R = 0.075.     

In Silico Analysis of Metabolites from Peruvian Native Plants as Potential Therapeutics against Alzheimer’s Disease

Background: Despite research on the molecular bases of Alzheimer’s disease (AD), effective therapies against its progression are still needed. Recent studies have shown direct links between AD progression and neurovascular dysfunction, highlighting it as a potential target for new therapeutics development. In this work, we screened and evaluated the inhibitory effect of natural compounds from native Peruvian plants against tau protein, amyloid beta, and angiotensin II type 1 receptor (AT1R) pathologic AD markers. Methods: We applied in silico analysis, such as virtual screening, molecular docking, molecular dynamics simulation (MD), and MM/GBSA estimation, to identify metabolites from Peruvian plants with inhibitory properties, and compared them to nicotinamide, telmisartan, and grapeseed extract drugs in clinical trials. Results: Our results demonstrated the increased bioactivity of three plants’ metabolites against tau protein, amyloid beta, and AT1R. The MD simulations indicated the stability of the AT1R:floribundic acid, amyloid beta:rutin, and tau:brassicasterol systems. A polypharmaceutical potential was observed for rutin due to its high affinity to AT1R, amyloid beta, and tau. The metabolite floribundic acid showed bioactivity against the AT1R and tau, and the metabolite brassicasterol showed bioactivity against the amyloid beta and tau. Conclusions: This study has identified molecules from native Peruvian plants that have the potential to bind three pathologic markers of AD.