A cost effectiveness approach for determining the purchasing and operating policies of a combined meteorological data gathering system

The model we present in this paper was developed to solve a meteorological equipment operations problem involving the purchase and operation of specialized aircraft for the gathering of meteorological data. This aircraft system (termed ‘System B’) will be used to supplement an existing system using weather balloons (termed ‘System A’). The problem involves decision making based upon bi-criterion objectives. These objectives usually occur in the presence of one or both of the following factors: (a) The outputs of the systems have more than one attribute and (b) the outputs may be measured under varying environmental situations. The specific type of problem treated here involves a two objective situation arising from the latter factor. It was found out that due to the nature of this problem it was difficult to implement a utility approach to generate a solution. Therefore, a cost-effectiveness approach is presented to demonstrate a technique for finding the trade-off function between objectives for varying levels of systems and operating characteristics. This approach is similar to that of Subramanian and Ravichandran [8] where a complex two-unit electronic system was studied.     

Stereoselective synthesis of P-chiral phosphorus compounds from N-tert-butoxycarbonyl amino acids

Reaction of the N-t-Boc amino acids alanine and valine with PhPCl(2) gives the P-chiral trans-1,3,2-oxazaphospholidinones exclusively. Variable-temperature NMR and examination of the glycine derivative shows that the isomers observed are due to t-Boc rotation.     

Directed evolution of enzymes: new biocatalysts for asymmetric synthesis

Directed evolution has been employed to generate new enzymes for the deracemisation of chiral amines.     

Phenoxodiol protects against Cisplatin induced neurite toxicity in a PC-12 cell model

Background  

Many commonly used chemotherapeutic agents, such as Cisplatin, are restricted in their potential anti-neoplastic effectiveness by their side effects, with one of the most problematic being induction of peripheral neuropathy. Although a number of different neurotrophic, neuroprotective or anti-oxidant treatments have been tried in order to prevent or treat the neuropathies, to date they have met with limited success. Phenoxodiol is a new chemotherapeutic agent that has anti-proliferative and apoptotic effects on a range of cancer cells. PC12 cells are a commonly used neuronal cell model for examination of neurite outgrowth. In this study we examined whether phenoxodiol could protect against Cisplatin induced neurite inhibition in PC12 cells as an indication of the potential to protect against neuropathy.     

The molecular structure of different species of cuprous chloride from gas-phase electron diffraction and quantum chemical calculations

The molecular geometry of gaseous cuprous chloride oligomers was determined by gas-phase electron diffraction at two different temperatures. Quantum chemical calculations were also performed for Cu(n)Cl(n) (n=1-4) molecules. A complex vapor composition was found in both experiments. Molecules of Cu(3)Cl(3) and Cu(4)Cl(4) were present at the lower temperature (689 K), while dimeric molecules (Cu(2)Cl(2)) were found in addition to the trimers and tetramers at the higher temperature (1333 K). All Cu(n)Cl(n) species were found to have planar rings by both experiment and computation. The bond lengths from electron diffraction (r(g)) at 689 K are 2.166+/-0.008 A and 2.141+/-0.008 A and the Cu-Cl-Cu bond angles are 73.9+/-0.6 degrees and 88.0+/-0.6 degrees for the trimer and the tetramer, respectively. At 1333 K the bond lengths are 2.254+/-0.011 A, 2.180+/-0.011 A, and 2.155+/-0.011 A, and the Cu-Cl-Cu bond angles 67.3+/-1.1 degrees, 74.4+/-1.1 degrees, and 83.6+/-1.1 degrees for the dimer, trimer, and tetramer, respectively.