Bis(thio­cyanato-κN)[tris­(2-pyridylmeth­yl)amine-κ4 N,N′,N′′,N′′′]nickel(II) methanol hemisolvate

The title complex, [Ni(NCS)2(C18H18N4)]·0.5CH3OH, consists of two crystallographically distinct complexes and a methanol solvent mol­ecule. The NiII complexes are pseudo-octa­hedral six-coordinate, with the tris­(2-pyridylmeth­yl)amine (TPA) ligand providing four N atoms and two N-bound thio­cyanates providing the final two N atoms. The distances and angles are typical for NiII–TPA complexes. The compound has unit-cell parameters that are surprisingly similar to the previously reported hydrate

Ethyl 2-(4-chloro-2-oxo-2,3-dihydro-1,3-benzothia­zol-3-yl)acetate

In the mol­ecule of the title compound, C11H10ClNO3S, the benzene and thia­zole rings are oriented at a dihedral angle of 1.25 (3)°. Intra­molecular C—H⋯O and C—H⋯Cl inter­actions result in the formation of two five-membered rings which both adopt envelope conformations

An Experimental and Analytical Investigation of Stirling Space Power Converter Heater Head

NASA has identified the Stirling power converter as a prime candidate for the next generation power system for space applications requiring 60000 hr of operation. To meet this long-term goal, several critical components of the power converter have been analyzed using advanced structural assessment methods. Perhaps the most critical component, because of its geometric complexity and operating environment, is the power converter's heater head. This report describes the life assessment of the heater head which includes the characterization of a viscoplastic material model, the thermal and structural analyses of the heater head, and the interpolation of fatigue and creep test results of a nickel-base superalloy, Udimet 720 LI (Low Inclusions), at several elevated temperatures for life prediction purposes

2-Amino-5,7-bis­(4-fluoro­phen­yl)-1′,3′-dimethyl-7,8-dihydro­spiro­[pyrido[2,3-d]pyrimidine-6(5H),5′-pyrimidine]-2′,4,4′,6′(3H,1′H,3′H,5′H)-tetra­one ethanol solvate

In the mol­ecule of the title compound, C24H20F2N6O4·C2H5OH, the pyrimidine ring is oriented at dihedral angles of 42.64 (3) and 62.94 (3)° with respect to the benzene rings, while the dihedral angle between the benzene rings is 74.45 (3)°. The pyridine ring adopts an envelope conformation. In the crystal structure, inter­molecular N—H⋯O and O—H⋯N hydrogen bonds link the mol­ecules into a two-dimensional network, forming R 2 2(8) ring motifs. π–π contacts between the pyrimidine and benzene rings [centroid–centroid distances = 3.516 (1) and 3.927 (1) Å] may further stabilize the structure

Topology of biological networks and reliability of information processing

Biological systems rely on robust internal information processing: Survival depends on highly reproducible dynamics of regulatory processes. Biological information processing elements, however, are intrinsically noisy (genetic switches, neurons, etc.). Such noise poses severe stability problems to system behavior as it tends to desynchronize system dynamics (e.g. via fluctuating response or transmission time of the elements). Synchronicity in parallel information processing is not readily sustained in the absence of a central clock. Here we analyze the influence of topology on synchronicity in networks of autonomous noisy elements. In numerical and analytical studies we find a clear distinction between non-reliable and reliable dynamical attractors, depending on the topology of the circuit. In the reliable cases, synchronicity is sustained, while in the unreliable scenario, fluctuating responses of single elements can gradually desynchronize the system, leading to non-reproducible behavior. We find that the fraction of reliable dynamical attractors strongly correlates with the underlying circuitry. Our model suggests that the observed motif structure of biological signaling networks is shaped by the biological requirement for reproducibility of attractors.Comment: 7 pages, 7 figure

catena-Poly[[[diiodidocadmium(II)]-μ-1-(4-pyridylmeth­yl)-1H-benzimidazole] methanol hemisolvate]

In the title coordination polymer, {[CdI2(C13H11N3)]·0.5CH4O}n, each CdII center is four-coordinated by two N-atom donors from two 1-(4-pyridylmeth­yl)-1H-benzimidazole (L) ligands and two iodide anions, forming a tetra­hedral coordination geometry. L ligands bridge adjacent CdII ions, generating two crystallographically independent approximately orthogonal one-dimensional chains. The methanol solvent mol­ecule associates with one of the chains via O—H⋯I inter­actions

TRPA1 mediates changes in heart rate variability and cardiac mechanical function in mice exposed to acrolein

Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone. Conscious unrestrained wild-type C57BL/6 (WT) and TRPA1 knockout (KO) mice implanted with radiotelemeters were exposed once to 3 ppm acrolein, 0.3 ppm ozone, or filtered air. Heart rate (HR) and electrocardiogram (ECG) were recorded continuously before, during and after exposure. Analysis of ECG morphology, incidence of arrhythmia and heart rate variability (HRV) were performed. Cardiac mechanical function was assessed using a Langendorff perfusion preparation 24 h post-exposure. Acrolein exposure increased HRV independent of HR, as well as incidence of arrhythmia. Acrolein also increased left ventricular developed pressure in WT mice at 24 h post-exposure. Ozone did not produce any changes in cardiac function. Neither gas produced ECG effects, changes in HRV, arrhythmogenesis, or mechanical function in KO mice. These data demonstrate that a single exposure to acrolein causes cardiac dysfunction through TRPA1 activation and autonomic imbalance characterized by a shift toward parasympathetic modulation. Furthermore, it is clear from the lack of ozone effects that although gaseous irritants are capable of eliciting immediate cardiac changes, gas concentration and properties play important roles

2-Chloro-5-methyl-3-nitro­pyridine

The title compound, C6H5ClN2O2, crystallizes with two independent mol­ecules in the asymmetric unit. Inter­molecular C—H⋯O hydrogen bonds stabilize the crystal structure

3-Bromo-9-(4-chloro­benz­yl)-9H-carbazole

The title compound, C19H13BrClN, was synthesized by N-alkyl­ation of 4-chloro-1-(chloro­meth­yl)benzene with 3-bromo-9H-carbazole. The carbazole ring system is essentially planar, with a mean deviation of 0.028 Å, and it makes a dihedral angle of 91.2 (3) Å with the plane of the benzene ring