Tetrahydrobiopterin, the cofactor required for hydroxylation of aromatic amino acids regulates its own synthesis in mammals through feedback inhibition of GTP cyclohydrolase I. This mechanism is mediated by a regulatory subunit called GTP cyclohydrolase I feedback regulatory protein (GFRP). The 2.6 A resolution crystal structure of rat GFRP shows that the protein forms a pentamer. This indicate...

in this paper, nonlinear behavior of composite steel plate shear wall systems, in which steel infill plate is strengthened by fiber reinforced polymer (frp) layers, are experimentally investigated. tests are designed to evaluate the effect of glass-frp layers, layers number of gfrp and orientation of gfrp layers on the stiffness, shear strength, cumulative dissipated energy and other seismic pa...

–The paper presents the results of a study on the performance of Glass Fibre Reinforced Polymer (GFRP) wrapped high strength concrete columns under uni-axial compression. The columns had slenderness ratios of 8, 16, 24 and 32. Three types of wrap materials (Chopped Strand Mat GFRP, Uni-Directional Cloth GFRP and Woven Roving GFRP) were used with 3 mm and 5 mm thicknesses. The columns were teste...

OBJECTIVE In our previous study, glass-fiber-reinforced plastics (GFRPs) made from polycarbonate and glass fibers were prepared for esthetic orthodontic wires using pultrusion. These laboratory GFRP wires are more transparent than the commercially available nickel-titanium wire; however, an investigation of the color stability of GFRP during orthodontic treatment is needed. Accordingly, in the ...

Several efforts were made over the years to control vibration of structural components made of composite materials. This paper consists of study on effect of using shape memory alloy (SMA) to increase the damping of glass fiber reinforced plastic (GFRP) composites. A comparative study between SMA and steel was made as reinforcement material in GFRP composites to enhance damping. Dimensions of e...

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Long-Term Performance of GFRP Reinforcement URL: http://tti.tamu.edu/documents/0-6069-1.pdf 16. Abstract Significant research has been performed on glass fiber-reinforced polymer (GFRP) concrete reinforcement. This research has shown that GF...

RATIONALE GTP cyclohydrolase I (GTPCH-1) is the rate-limiting enzyme involved in de novo biosynthesis of tetrahydrobiopterin (BH(4)), an essential cofactor for NO synthases and aromatic amino acid hydroxylases. GTPCH-1 undergoes negative feedback regulation by its end-product BH(4) via interaction with the GTP cyclohydrolase feedback regulatory protein (GFRP). Such a negative feedback mechanism...

Overproduction of nitric oxide (NO) by inducible NO synthase contributes toward refractory hypotension, impaired microvascular perfusion, and end-organ damage in septic shock patients. Tetrahydrobiopterin (BH4) is an essential NOS cofactor. GTP cyclohydrolase 1 (GCH1) is the rate-limiting enzyme for BH4 biosynthesis. Under inflammatory conditions, GCH1 activity and hence BH4 levels are increase...

Reinforced concrete structures consists of two main components and the behavior of these structures influenced by gender and material properties, in order to investigate the behavior of concrete reinforced beam that most important flexural element in reinforced concrete structures, we chosen High Strength Concrete (HSC) for concrete and GFRP and steel bars for reinforcement. For compare the new...