Interference of the carbohydrate moiety in coomassie brilliant blue R-250 protein staining

The binding of Coomassie Brilliant Blue R-250 to several species of bovine pancreatic ribonuclease is affected by the presence of a carbohydrate moiety in the enzyme molecule. Enzymic deglycosylation of several chromatographic fractions of ribonuclease, which have different degrees of glycosylation, results in increased staining by Coomassie Brilliant Blue R-250. Ovalbumin and other glycoproteins tested show similar behavior. The results indicate that carbohydrate moieties may represent a common hindrance to the binding of Coomassie Brilliant Blue dyes to glycoproteins.     

1,2-dioxines as masked cis gamma-hydroxy enones and their versatility in the synthesis of highly substituted gamma-lactones

Addition of highly stabilized ester nucleophiles to 1,2-dioxines affords good to high yields of gamma-lactones with high diastereoselectivity. Heterolytic or homolytic cleavage of the 1,2-dioxines under appropriate conditions generates the key reactive cis gamma-hydroxy enones, which ultimately afford the observed gamma-lactones. Diastereoselectivity is installed as a result of anti 1,4-addition by the ester enolate to the cis enones followed by intramolecular cyclization. The reaction is tolerant of a range of substitution patterns on the 1,2-dioxine while a broad range of esters are also accommodated. In addition to the synthesis of racemic gamma-lactones, highly enantioenriched gamma-lactones can also be synthesized when chiral cobalt(II) catalysts are employed for the initial homolytic ring-opening of the 1,2-dioxine.     

Crystal and molecular structures of 2′-nitro-4-aminobiphenyl and 2-amino-7-nitrofluorene

2′-nitro-4-aminobiphenyl (5), C₁₂H₁₀N₂O₂, crystallizes in the monoclinic space groupP2₁/c:a = 6.043(2),b =15.795(3),c = 11.577(2) Å, β = 103.42(8) °;D _c = 1.324 g cm^?3 forZ = 4. 2-amino-7-nitrofluorene (3), C₁₃H₁₀N₂O₂, crystallizes in the monoclinic space groupP2₁ n:a = 10.765(2),b = 7.454(4),c = 12.959(2) Å, β = 95.44(1) °;D _c = 1.451 g cm^?3 forZ = 4. Three-dimensional CuKα intensity data were measured with a computer-controlled diffractometer, and the initial phases were obtained by direct methods. The two structures were refined by the full-matrix least-squares method, which gave finalR values for 5 and 3 of 0.045 and 0.043, respectively. Bond lengths in the compounds are normal, apart from slight shortening of the phenyl-phenyl C-C bond and some distortion of the phenyl rings caused by the amino and nitro groups. In 5, the two phenyl rings are twisted by 57.1 °, and the nitro group is twisted by 34.6 ° from the plane of its phenyl group. The carbon backbone of 3 is nearly planar with the two phenyl groups tilted by 4.0 ° to each other. The nitro group in 3 is twisted 5.7 ° from the plane of its phenyl group. There is amino hydrogen to nitro oxygen intermolecular hydrogen bonding in each structure.     

Adapting the task-taxon-task methodology to model the impact of chemical protective gear

The Task-Taxon-Task method (Anno et al. DNA-TR-95-115, 1996) is a statistical modeling approach to predict performance decrements on behavioral tasks in response to various stressors. We describe the basics of the T3 method and our approach to adapting it to handle more acute stressors, which can require decomposition into task networks via logical or empirical analysis. We provide an illustrative example showing how the method can be used to account for performance decrements in manual tasks associated with wearing protective gloves. This illustration provides a substantive application in which the current T3 method can be augmented to account for performance decrements in a new sub-domain, while additionally providing lessons for extending the method to new stressors, performance domains, and behavior modeling systems.     

Clifford Fourier Transformation and Uncertainty Principle for the Clifford Geometric Algebra Cl 3,0

First, the basic concept of the vector derivative in geometric algebra is introduced. Second, beginning with the Fourier transform on a scalar function we generalize to a real Fourier transform on Clifford multivector-valued functions Third, we show a set of important properties of the Clifford Fourier transform on Cl_3,0 such as differentiation properties, and the Plancherel theorem. Finally, we apply the Clifford Fourier transform properties for proving an uncertainty principle for Cl_3,0 multivector functions.