A convergent approach to the marine natural product eleutherobin: synthesis of key intermediates and attempts to produce the basic skeleton

Synthesis of (1R,5R,6R)-2-(6-hydroxymethyl-5-isopropyl-2-methylcyclohex-2-enyl)-N- methoxy-N-methylacetamide 8 from R-(-)-phellandrene in six steps, and (3aR*,4S*,6R*,6aS*)- (6-hydroxymethyl-4-methoxy-2,2,6-trimethyltetrahydrofuro[3,4-d][1,3]dioxol- 4-yl)acetic acid methyl ester 17 from tetrabromoacetone and 2-methoxy-5-methylfuran in six steps, provided two key fragments which have been combined to produce intermediates for attempted construction of the basic skeleton of eleutherobin.     

Identification of prion protein genotype in sheep: 11 years of proficiency tests in Italy

Accreditation and Quality Assurance - Scrapie of sheep belongs to a group of fatal neurodegenerative diseases known as prion diseases. Scrapie is a naturally transmissible disease and sheep...     

Dirichlet‐to‐Neumann Map for a Nonlinear Diffusion Equation

A nonlinear diffusive equation with moving boundaries is analyzed by constructing the corresponding Dirichlet‐to‐Neumann map. In particular, the Dirichlet boundary value and the initial condition are used to derive the unknown Neumann boundary value. Then, a contraction‐mapping technique is used to prove existence and uniqueness of the solution for small times.     

Minimum cost multi-product flow lines

In this paper, the problem of finding the minimum cost flow line able to produce different products is considered. This problem can be formulated as a shortest path problem on an acyclic di-graph when the machines graph associated with each product family is a chain or a comb. These graphs are relevant in production planning when dealing with pipelined assembly systems. We solve the problem using A ^* algorithm which can be efficiently exploited when there is a good estimate on the value of an optimal solution. Therefore, we adapt a known bound for the Shortest Common Supersequence problem to our case and show the effectiveness of the approach by presenting an extensive computational experience.     

Synthesis and Crystal Structure of a New Diamine Complex CuCl_4(H_2tn)

Introduction During the past several decades, diamines and their derivatives have been extensively investigated in both basic research and their application. The result shows that they can form stable complexes with many transi-tion metals. These complexes would be widely applied in various fields such as biotechnology,1 synthesis,2 food processing industry,3 environmental science,4 biochemistry,5 etc. Especially, in recent years, more and more attention is placed on their other peculiarities.…     

Experimental cross section evaluation for innovative 99Mo production via the (α,n) reaction on 96Zr target

The high-specific activity ⁹⁹Mo accelerator-based production, via the (α,n) reaction on ⁹⁶Zr-enriched target, has been investigated in the present work. The excitation function measurement has been performed in the energy range 8–34 MeV at the ARRONAX facility, using the well-known stacked foils technique on natural zirconium as target. A general good agreement in the cross section trend has been observed, once compared to former measurements. A different (i.e. higher) peak value and a shift of about 2 MeV towards larger energies have however been found. Assuming a fully enriched ⁹⁶Zr target irradiated by an α-beam at suitable energy (E = 25 MeV), the ⁹⁹Mo production yield has thus been estimated. At last the alternative production routes, based on the ⁹⁶Zr(α,n)⁹⁹Mo and ¹⁰⁰Mo(p,x)⁹⁹Mo/^99mTc reactions, are compared.     

Parallel dedicated machines scheduling with chain precedence constraints

A set of n nonpreemptive tasks are to be scheduled on m parallel dedicated machines with a regular criterion. Chain precedence constraints among the tasks, deterministic processing times and processing machine of each task are given.     

Fragile to strong crossover and Widom line in supercooled water: A comparative study

The aim of this paper is to discuss the relationship between the dynamics and thermodynamics of water in the supercooled region. Reviewed case studies comprehend bulk water simulated with the SPC/E, TIP4P and TIP4P/2005 potentials, water at protein interfaces, and water in solution with electrolytes. Upon supercooling, the fragile to strong crossover in the α-relaxation of water is found to occur when the Widom line emanating from the liquid-liquid critical point is crossed. This appears to be a general characteristic of supercooled water, not depending on the applied interaction potential and/or different local environments.     

Toward a microscopic description of molecular electronic systems

The many-body perturbation theory is reformulated within the dielectric function method presented in the preceding paper [12]. The self-energy effects are explicitly considered. These corrections turn out to be important and are calculated to the same level of approximation as the corresponding local-field terms. The method is at the moment applicable to π-electron systems within the zero differential overlap approximation. Explicit calculations of the excitation energies for the benzene molecule, using different parametrizations, are presented. Comparison is made with the results obtained in the random phase approximation (RPA ) and other schemes.