A Motif for Infinite Metal Atom Wires

A new motif for infinite metal atom wires with tunable compositions and properties is developed based on the connection between metal paddlewheel and square planar complex moieties. Two infinite Pd chain compounds, [Pd₄(CO)₄(OAc)₄Pd(acac)₂] 1 and [Pd₄(CO)₄(TFA)₄Pd(acac)₂] 2 , and an infinite Pd? Pt heterometallic chain compound, [Pd₄(CO)₄(OAc)₄Pt(acac)₂] 3 , are identified by single‐crystal X‐ray diffraction analysis. In these new structures, the paddlewheel moiety is a Pd four‐membered ring coordinated by bridging carboxylic ligands and μ₂ carbonyl ligands. The planar moiety is either Pd(acac)₂ or Pt(acac)₂ (acac=acetylacetonate). These moieties are connected by metallophilic interactions. The results showed that these one‐dimensional metal wire compounds have photoluminescent properties that are tunable by changing ligands and metal ions. 3 can also serve as a single source precursor for making Pd₄Pt bimetallic nanostructures with precise control of metal composition.     

Confidence estimation for tolerance intervals

The post-data performances of normal tolerance intervals are studied. Under a robust Bayesian predictive scheme, we establish the ordering and bounds of the confidence estimators. It is found that the nominal confidence coefficient tends to be extreme yet coincides with the limiting Bayes estimators in some scenarios. A remark on the choice of beta priors is also given.     

Off-axis performance analysis of wavefront coded imaging system

Point spread functions at different field angles and phase deviations of the cubic mask are used for image restoration to analyze the off-axis performance of a wavefront coded imaging system.     

Regioselectivity of Catechol O-Methyltransferase Confers Enhancement of Catalytic Activity

Catechol O-methyltransferase (COMT) metabolizes catechol moieties by methylating a single hydroxyl group at the meta- or para- hydroxyl position. Hydrophobic amino acids near the active site of COMT influence the regioselectivity of this reaction. Our sequence analysis highlights their importance by showing that these residues are highly conserved throughout evolution. Reaction barriers calculated in the gas phase reveal a lower barrier during methylation at the meta- position, suggesting that the observed meta-regioselectivity of COMT can be attributed to the substrate itself, and that COMT has evolved residues to orient the substrate in a manner that increases the rate of catalysis.     

Total synthesis of moniliformediquinone and calanquinone A as potent inhibitors for breast cancer

The first synthesis of moniliformediquinone has been achieved in which the longest linear sequence is only nine steps. The synthesis proceeds in 23% overall yield from commercially available 2,4,5-trimethoxybenzaldehyde. The key transformations include a Pd-catalyzed coupling between a phenyl triflate and an acetylene, and a TiCl₄-mediated cyclization of a benzoquinone intermediate. In addition, in vitro inhibitory effects of moniliformediquinone, denbinobin, moscatilin, and calanquinone A were determined to have IC₅₀ values of 0.7, 1.6, 2.5, and 1.5 μM, respectively.     

Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)chromones

A general procedure was proposed for the synthesis of 3-(5-aryl-1,3,4-oxadiazol-2-yl)chromones by reaction of 3-formylchromone with aroylhydrazines, transformation of the corresponding acylhydrazones into 1,3-dipoles by the action of bromine in the presence of sodium acetate, and intramolecular ring closure.     

Improvement of productivity of yeast cell with a novel airlift loop reactor

Applied Biochemistry and Biotechnology - Two different strains of baker’s yeast are cultivated using a fed-batch process with a novel airlift loop reactor. The reactor can be operated not...     

A dual perturbation view of linear programming

Solving standard-form linear prograrns via perturbation of the primal objective function has received much attention recently. In this paper, we investigate a new perturbation scheme which obtains a dual optimal solution by perturbing the dual feasible domain under different norms. A dual-to-primal conversion formula is also provided. We show that this new perturbation scheme actually generalizes the primal entropic perturbation approach to linear programming.Partially sponsored by the North Carolina Supercomputing Center 1994 Cray Research Grant and the National Textile Center Research Grant.     

Nonrenormalizability of Einstein-Yang-Mills interactions at the one-loop level

The interactions between the quantized Einstein and quantized Yang-Mills fields are one-loop nonrenormalizable.