It is difficult to apply traditional Minimum spanning tree(MST) algorithms to a large dataset since the time complexity of the algorithms is quadratic. In this paper, we present a fast approximate MST framework on the complete graph of N points, and any exact MST algorithm can be incorporated into the framework and speeded up. The proposed framework employs a divide-and-conquer scheme to produc...

Styrene is widely used in the manufacture of synthetic rubber, resins, polyesters and plastics. Styrene and the primary metabolite styrene-7,8-oxide are genotoxic and carcinogenic. Long-term chemical carcinogenesis bioassays showed that styrene caused lung cancers in several strains of mice and mammary cancers in rats and styrene-7,8-oxide caused tumours of the forestomach in rats and mice and ...

The structure and vibrational frequencies of styrene and trans-b-methyl styrene in the lowest three singlet states ~S0 , S1 , and S2! have been calculated using ab initio quantum chemical methods. The frequencies are compared with experimental data obtained in the bulk and in a supersonic jet. The calculation shows that in the ground state the molecules have a broad shallow potential as a funct...

Styrene is one of the most important monomers produced worldwide. IARC classified styrene as a possible carcinogen to humans (group 2B). Styrene-7,8-oxide (SO) is the main reactive metabolite of styrene, and it is found to be genotoxic in several in vitro test systems. Styrene and styrene-7,8-oxide (SO) toxicity to HepG2 cells was investigated by evaluating end-points such as heat shock protein...

The aim of this study was to investigate whether genetic polymorphisms of CYP2E1, GSTM1, and GSTT1 and lifestyle habits (smoking, drinking, and exercise) modulate the levels of urinary styrene metabolites such as mandelic acid (MA) and phenylglyoxylic acid (PGA) after occupational exposure to styrene. We recruited 79 male workers who had received chronic exposure in styrene fiberglass-reinforce...

Currently, about 75% of Finnish reinforced polyester lamination workers are exposed to styrene concentrations exceeding the current occupational exposure limit of 20 ppm. Several measures have been proposed to control styrene exposure, but only a few of them are capable of keeping the styrene concentration below 20 ppm. The present study was carried out to evaluate current ventilation systems i...