COPPER BENZOCHLORIN, A NOVEL PHOTOSENSITIZER FOR PHOTODYNAMIC THERAPY: EFFECTS ON A TRANSPLANTABLE UROTHELIAL TUMOR

Abstract— An iminum salt of octaethylbenzochlorin with copper in the aromatic ring, CDSI, was tested for its tumoricidal effects on theA–27 N-[4-(5-notro-2-furyl)-2-thiazoly] formamide tumor line. CDSI was found to be an effective photosensitiz4r in vivo when used in combination with either a xenon arc lamp or a pulsed alexandrite laser. Hemodynamically, CDSI and light caused a rapid decrease in tumor blood flow. skin photosensitization was found to be minimal when drug-injected mice werwe illuminated in a solar simulator.     

The surface reconstructions of the (100) crystal faces of iridium,platinum and gold: I. Experimental observations and possible structural models

The structures of the reconstructed Ir(100), Pt(100) and Au(100) surfaces have been investigated. Low energy electron diffraction (LEED) patterns are analyzed and LEED intensity versus energy data are measured. A variety of structures is observed by LEED: Ir(100) exhibits a relatively simple (1 × 5) pattern; Pt(100) shows a series of closely related patterns, a typical representative of which has a $\text{(}\text{14}\text{1}\text{?1}\text{5}\text{)}$ structure; Au(100) usually exhibits a c(26 × 68) pattern, often inaccurately described in the literature as a (20 × 5) pattern. The reconstruction of Au(111) is also considered for comparison. Various plausible structural models are discussed, while laser simulation is used to lessen the number of these models. The analysis is completed in a companion paper where LEED intensity calculations are reported to determine the atomic locations.     

Nonlinear pedagogy: a constraints-led framework for understanding emergence of game play and movement skills

Team sport competition can be characterized as a complex adaptive system in which concepts from nonlinear dynamics can provide a sound theoretical framework to understand emergent behavior such as movement coordination and decision making in game play. Nonlinear Pedagogy is presented as a methodology for games teaching, capturing how phenomena such as movement variability, self-organization, emergent decision making, and symmetry-breaking occur as a consequence of interactions between agent-agent and agent-environment constraints. Empirical data from studies of basketball free-throw shooting and dribbling are used as task vehicles to exemplify how nonlinear phenomena characterize game play in sport. In this paper we survey the implications of these data for Nonlinear Pedagogy, focusing particularly on the manipulation of constraints in team game settings. The data and theoretical modeling presented in this paper provide a rationale in nonlinear dynamics for the efficacy of a prominent model of game play teaching, Teaching Games for Understanding approach.     

Evolution in predator–prey systems

We study the adaptive dynamics of predator–prey systems modeled by a dynamical system in which the traits of predators and prey are allowed to evolve by small mutations. When only the prey are allowed to evolve, and the size of the mutational change tends to 0, the system does not exhibit long term prey coexistence and the trait of the resident prey type converges to the solution of an ODE. When only the predators are allowed to evolve, coexistence of predators occurs. In this case, depending on the parameters being varied, we see that (i) the number of coexisting predators remains tight and the differences in traits from a reference species converge in distribution to a limit, or (ii) the number of coexisting predators tends to infinity, and we calculate the asymptotic rate at which the traits of the least and most “fit” predators in the population increase. This last result is obtained by comparison with a branching random walk killed to the left of a linear boundary and a finite branching–selection particle system.     

Combined Photoredox/Enzymatic C−H Benzylic Hydroxylations

Chemical transformations that install heteroatoms into C?H bonds are of significant interest because they streamline the construction of value‐added small molecules. Direct C?H oxyfunctionalization, or the one step conversion of a C?H bond to a C?O bond, could be a highly enabling transformation due to the prevalence of the resulting enantioenriched alcohols in pharmaceuticals and natural products,. Here we report a single‐flask photoredox/enzymatic process for direct C?H hydroxylation that proceeds with broad reactivity, chemoselectivity and enantioselectivity. This unified strategy advances general photoredox and enzymatic catalysis synergy and enables chemoenzymatic processes for powerful and selective oxidative transformations.     

Crystal structures of the cobalt(III), nickel(II), copper(II), and zinc(II) complexes of 2-thio-6-picoline N-oxide

Structures of the following compounds have been solved: tris(2-thio-6-picoline N-oxide)cobalt(III), [Co(6MOS)₃], orthorhombic, Pca2₁, a = 17.871(3), b = 14.061(2), c = 15.964(2) Å, V = 4011(1) ų, Z = 8, and = 1.193 mm^–1; bis (2-thio-6-picoline N-oxide)nickel(II), [Ni(6MOS)₂], orthorhombic, Pbca, a = 15.602(8), b = 13.606(4), c = 13.348(8) Å, V = 2833(4) ų, Z = 8, and = 1.655 mm^–1; bis(2-thio-6-picoline N-oxide)copper(II), [Cu(6MOS)₂], orthorhombic, Pbca, a = 13.914(5), b = 12.984(5), c = 15.663(6) Å, V = 2830(2) ų, Z = 8, and = 1.836 mm^–1; and bis(2-thio-6-picoline N-oxide)zinc(II), [Zn(6MOS)₂], triclinic, P – 1, a = 7.9737(8), b = 11.7786(9), c = 7.9206(8) Å, = 104.502(7), = 104.495(8), = 93.445(8)°, V = 691.3(1) ų, Z = 2, and = 2.106 mm^–1. The steric effect of the methyl group in the six-position of the N-oxide ring is considered in comparing these structures to complexes of 2-thiopyridine N-oxide.     

Raney-Co mediated reductive cyclization of an alpha,beta-unsaturated nitrile

An expedient, five step synthesis of caprolactam 1 is reported starting from natural L-homoserine. The key step is a chemoselective reductive cyclization of alpha,beta-unsaturated nitrile 10 mediated by Raney-Co type metals. This hydrogenation is extensively investigated in order to account for the observed product distribution and yields.     

Spatially Directed Pyrolysis via Thermally Morphing Surface Adducts

Combustion is often difficult to spatially direct or tune associated kinetics—hence a run-away reaction. Coupling pyrolytic chemical transformation to mass transport and reaction rates (Damköhler number), however, we spatially directed ignition with concomitant switch from combustion to pyrolysis (low oxidant). A ‘surface-then-core’ order in ignition, with concomitant change in burning rate,is therefore established. Herein, alkysilanes grafted onto cellulose fibers are pyrolyzed into non-flammable SiO₂ terminating surface ignition propagation, hence stalling flame propagating. Sustaining high temperatures, however, triggers ignition in the bulk of the fibers but under restricted gas flow (oxidant and/or waste) hence significantly low rate of ignition propagation and pyrolysis compared to open flame (Liñán's equation). This leads to inside-out thermal degradation and, with felicitous choice of conditions, formation of graphitic tubes. Given the temperature dependence, imbibing fibers with an exothermically oxidizing synthon (MnCl₂) or a heat sink (KCl) abets or inhibits pyrolysis leading to tuneable wall thickness. We apply this approach to create magnetic, paramagnetic, or oxide containing carbon fibers. Given the surface sensitivity, we illustrate fabrication of nm- and μm-diameter tubes from appropriately sized fibers.     

Distribution of trenbolone residues in liver and various muscle groups of heifers that received multiple implants at the recommended site of application

Twenty heifers which were each administered 3 or 4 implants containing trenbolone acetate were slaughtered at 30 days post-implantation. Liquid chromatographic analyses were conducted on muscle collected from the rump, loin, shoulder, and neck, and on the liver of each animal. Residues present in liver were primarily 17alpha-trenbolone, and the residues found in the various muscle samples were primarily 17beta-trenbolone. The mean concentration of 17alpha-trenbolone in liver was 4.3 +/- 2.3 ng/g; the mean concentration of 17beta-trenbolone in muscle tissues was < 0.4 ng/g. There was a small but statistically significant effect of the number of implants used on the mean concentration of residues in loin muscles; animals with 3 trenbolone implants had higher mean residue concentrations than animals with 4 trenbolone implants. This suggests that, though the impact of implant numbers on the mean concentration of residues in muscle tissues is negligible relative to currently generally accepted maximum residue levels, mechanisms may exist for selective distribution and retention of residues within different muscle groups.