Techniques have been developed to measure FdUMP, the active metabolite of 5-FUra; thymidylate synthetase (TMP synthase; 5,10-methylenetetrahydrofolate:dUMP C-methyltransferase, EC 2.1.1.45), the target enzyme for this antimetabolite; and dUMP, the substrate that competes with FdUMP for binding to TMP synthetase. As little as 0.02 pmol of FdUMP can be quantitated with a competitive ligand bindin...

The kinetics of the reaction catalyzed by thymidylate synthase from Lactobacillus casei were investigated at pH 6.8 and 30” with the natural isomer of 5,10-methylene5,6,7&tetrahydrofolate ((+)-CH,-H,folate). An apparatus for adding the enzyme to the reaction mixture and rapidly mixing without opening the sample compartment allowed the acquisition of spectrophotometric rate data within a few sec...

Mutant forms of thymidylate synthase (TS) with substitutions at the conserved active site residue, Trp 80, are deficient in the hydride transfer step of the TS reaction. These mutants produce a beta-mercaptoethanol (beta-ME) adduct of the 2'-deoxyuridine-5'-monophosphate (dUMP) exocyclic methylene intermediate. Trp 80 has been proposed to assist hydride transfer by stabilizing a 5,6,7,8-tetrahy...

OBJECTIVE This study aimed to determine if occupational exposure to whole-body vibration is associated with cervical intervertebral disc herniation among container truck drivers. METHODS We conducted a walk-through survey among container truck drivers and unexposed workers. We also measured the vibration hazard of the container truck over the driver's back and seat when the driver was loading...

Synchronous homopolar motors (SHMs) with an excitation winding located at the stator and a toothed salient pole rotor are good alternative to traditionally used in traction applications such as induction or interior permanent magnet synchronous (IPMSM). This study presents results of theoretical comparison between IPMSM SHM application constant power speed range 1:10, which is specific mining t...

dUTPase (deoxyuridine 5'-triphosphate nucleotide hydrolase) is an enzyme responsible for maintaining low levels of intracellular dUTP and thus prevents uracil incorporation into DNA by DNA polymerases during replication and repair processes. The thermodynamics of binding for both dUTP and dUMP (deoxyuridine 5'-monophosphate) to the D80A mutant form of Trypanosoma cruzi dUTPase have been investi...

Knopp et al. @J. Raman Spectrosc. 31, 51 ~2000!# have recently used resonant femtosecond coherent anti-Stokes Raman spectroscopy ~CARS! to prepare and probe highly excited vibrational wave packets on the ground electronic potential surface of molecular iodine. The experiment uses a sequence of three resonant femtosecond pulses with two independently variable time delays. The first two pulses ac...

This paper examines the determinants of truck accidents in the United States using a time series data set covering the period 1970–2001. Along with other factors, the effect of the Motor Carrier Act of 1980, which deregulated the trucking industry, is examined for its impact on truck accidents. In addition, the model accounts for the effect railroad freight mileage has on truck accidents. Empir...

We deployed a recently proposed single loop detector based, real-time freeway truck traffic volume estimation algorithm to a County-level traffic database. The scale-up of the algorithm is achieved by adding an extra layer, consisting of a spatial filtering component for removing noise and an aggregation component for efficient analysis. All calculations could be done in real-time to produce a ...

The Ports of Long Beach and Los Angeles are the largest container port complex in North America and fifth largest in the world. Growth in U.S. Pacific Rim trade has put pressure on the landside transportation systems serving these two ports. In order to address this growth and mitigate environmental impacts, the ports are implementing new operational strategies and infrastructure improvements. ...