Physical Sciences and Mathematics Commons^™

Copper(I) Complexes Of Heterocyclic Thiourea Ligands, Aakarsh Saxena, Emily C. Dugan, Jeffrey Liaw, Matthew D. Dembo, Robert D. Pike

Arts & Sciences Articles

The coordination of heterocyclic thiourea ligands (L = N-(2-pyridyl)-N′-phenylthiourea (1), N-(2-pyridyl)-N′-methylthiourea (2), N-(3-pyridyl)-N′-phenylthiourea (3), N-(3-pyridyl)-N′-methylthiourea (4), N-(4-pyridyl)-N′-phenylthiourea (5), N-(2-pyrimidyl)-N′-phenylthiourea (6), N-(2-pyrimidyl)-N′-methylthiourea (7), N-(2-thiazolyl)-N′-methylthiourea (8), N-(2-benzothiazolyl)-N′-methylthiourea (9), N,N′-bis(2-pyridyl)thiourea (10) and N,N′-bis(3-pyridyl)thiourea (11)) with CuX (X = Cl, Br, I, NO3) has been investigated. CuX:L product stoichiometries of 1:1–1:5 were found, with 1:1 being most common. X-ray structures of four 3-coordinate mononuclear CuXL2 complexes (CuCl(6)2, CuCl(7)2, CuBr(6)2, and CuBr(9)2) …

The Capacity For Multistability In Small Gene Regulatory Networks, Dan Siegal-Gaskins, Erich Grotewold, Gregory D. Smith

Arts & Sciences Articles

Background

Recent years have seen a dramatic increase in the use of mathematical modeling to gain insight into gene regulatory network behavior across many different organisms. In particular, there has been considerable interest in using mathematical tools to understand how multistable regulatory networks may contribute to developmental processes such as cell fate determination. Indeed, such a network may subserve the formation of unicellular leaf hairs (trichomes) in the model plant Arabidopsis thaliana.

Results

In order to investigate the capacity of small gene regulatory networks to generate multiple equilibria, we present a chemical reaction network (CRN)-based modeling formalism and describe …

Aqua {6,60-Dimethoxy-2,20-[Ethane-1,2- Diylbis(Nitrilomethylidyne)]Diphenolato}- (4-Hydroxybenzoato)Manganese(Iii), R. Reshma, V. Soumya, S. M. Simi, V. S. Thampidas, Robert D. Pike

Arts & Sciences Articles

The title compound, [Mn(C18H18N2O4)(C7H5O3)(H2O)], was synthesized by a template reaction of ethane-1,2-diamine and 3-methoxy­salicylaldehyde in presence of manganese(II) 4-hydroxy­benzoate. The Jahn-Teller-distorted manganese(III) centre has an octa­hedral geometry. Extensive O-HO hydrogen-bonding inter­actions generate a two-dimensional sheet structure parallel to (103).

Preparation Of 5-Bromo-2-Naphthol: The Use Of A Sulfonic Acid As A Protecting And Activating Group, Christopher J. Abelt

Arts & Sciences Articles

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2-naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid.

Enhanced Capacitative Calcium Entry And Sarcoplasmic-Reticulum Calcium Storage Capacity With Advanced Age In Murine Mesenteric Arterial Smooth Muscle Cells, John N. Buchholz, Sean M. Wilson, Ravi Goyal, Gregory D. Smith

Arts & Sciences Articles

Intracellular Ca(2+) signaling is important to perfusion pressure related arterial reactivity and to vascular disorders including hypertension, angina and ischemic stroke. We have recently shown that advancing-age leads to calcium signaling adaptations in mesenteric arterial myocytes from C57 BL/6 mice [Corsso, C.D., Ostrovskaya. O., McAllister, C.E., Murray, K., Hatton, W.J., Gurney, A.M., Spencer, N.J., Wilson, S.M., 2006. Effects of aging on Ca(2+) signaling in murine mesenteric arterial smooth muscle cells. Mech. Ageing Dev. 127, 315-323)] which may contribute to decrements in perfusion pressure related arterial contractility others have shown occur. Even still, the mechanisms underlying the changes in Ca(2+) signaling …

Piperazinium Chlorocuprates(I), Jacob E. Kuperstock, Amanda N. Ley, Robert D. Pike

Arts & Sciences Articles

The formation from aqueous solution of networks containing piperazinium hydrochlorides with copper(I) chloride is described. Four new X-ray crystal structures are reported: (H2Pip)[Cu2Cl4] (two isomeric phases: 1A and 1B), (H2MePip)[Cu3Cl5] (2), and (H2Me2Pip)[Cu4Cl6] (3) (Pip = piperazine, MePip = N-methylpiperazine, Me2Pip = N,N′-dimethylpiperazine. In 1A (P-1, a = 6.3141(2), b = 6.8248(2), c = 6.9067(2), α = 90.707(2), β = 110.748(2), γ = 110.799(2), V = 256.918(13), Z = 2) corner-sharing Cu2Cl2 rhomboid dimers form infinite chains running parallel to the a-axis. In 1B (Pbcn, a = 9.9442(6), b = 8.0622(5), …

Reduction Of Calcium Release Site Models Via Fast/Slow Analysis And Iterative Aggregation/Disaggregation, Yan Hao, Peter Kemper, Gregory D. Smith

Arts & Sciences Articles

Mathematical models of calcium release sites derived from Markov chain models of intracellular calcium channels exhibit collective gating reminiscent of the experimentally observed phenomenon of calcium puffs and sparks. Such models often take the form of stochastic automata networks in which the transition probabilities of each channel depend on the local calcium concentration and thus the state of the other channels. In order to overcome the state-space explosion that occurs in such compositionally defined calcium release site models, we have implemented several automated procedures for model reduction using fast/slow analysis. After categorizing rate constants in the single channel model as …