A heuristic approach for a scheduling problem with periodic maintenance and sequence-dependent setup times

In this paper we study a problem of sequencing jobs in a machine with programmed preventive maintenance and sequence-dependent setup times. To the authors’ knowledge, this problem has not been treated as such in the operations research literature. Computational experiments show that it is very hard to solve the problem by exact methods. Therefore, the contribution of this paper is to design and implement a solution approach based on metaheuristic procedures. The proposed method finds high quality solutions in very short computational times.     

葡萄籽“弹”起熟龄肤

皮肤老化永远是美丽最大的敌人,而抗氧化就成了延缓肌肤衰老的最有力武器。然而,自由基无时不在打击、破坏着我们的肌肤细胞,怎样才能挫败“氧化杀手”的“催老行动”,让我们美丽的肌肤放心地行驶在老化的慢行道上？     

Cyclic-cubes: a new family of interconnection networks of evenfixed-degrees

We introduce a new family of interconnection networks that are Cayley graphs with fixed degrees of any even number greater than or equal to four. We call the proposed graphs cyclic-cubes because contracting some cycles in such a graph results in a generalized hypercube. These Cayley graphs have optimal fault tolerance and logarithmic diameters. For comparable number of nodes, a cyclic-cube can have a diameter smaller than previously known fixed-degree networks. The proposed graphs can adopt an optimum routing algorithm known for one of its subfamilies of Cayley graphs. We also show that a graph in the new family has a Hamiltonian cycle and, hence, there is an embedding of a ring. Embedding of meshes and hypercubes are also discussed     

Multiple functionalization of fluorescent nanoparticles for specific biolabeling and drug delivery of dopamine

The development of fluorescent biolabels for specific targeting and controlled drug release is of paramount importance in biological applications due to their potential in the generation of novel tools for simultaneous diagnosis and treatment of diseases. Dopamine is a neurotransmitter involved in several neurological diseases, such as Parkinson's disease and attention deficit hyperactivity disorder (ADHD), and the controlled delivery of its agonists already proved to have beneficial effects both in vitro and in vivo. Here, we report the synthesis and multiple functionalization of highly fluorescent CdSe/CdS quantum rods for specific biolabeling and controlled drug release. After being transferred into aqueous media, the nanocrystals were made highly biocompatible through PEG conjugation and covered by a carbohydrate shell, which allowed specific GLUT-1 recognition. Controlled attachment of dopamine through an ester bond also allowed hydrolysis by esterases, yielding a smart nanotool for specific biolabeling and controlled drug release.