Elevated neurofilament light chain and its correlation with MRS-based metabolites suggest early neuronal injury in a subset of participants with primary HIV infection through mechanisms involving central nervous system inflammation.

Objective: We examined the longitudinal effects of primary HIV infection (PHI) and responses to early antiretroviral therapy (ART) on the brain using high-field magnetic resonance spectroscopy (MRS).Methods: Cerebral metabolites were measured longitudinally with 4T proton MRS and assessed for ART effects in participants with PHI. Levels of glutamate (Glu), N-acetylaspartate (NAA), myo-inositol (MI), and choline-containing metabolites (Cho) were measured relative to creatine 1 phosphocreatine (Cr) in anterior cingulate, basal ganglia, frontal white matter, and parietal gray matter.Results: Fifty-three participants recruited at median 3.7 months post HIV transmission were followed a median 6.0 months. A total of 23 participants initiated ART during follow-up. Prior to ART, increases per month were observed in Cho/Cr (slope 5 0.0012, p 5 0.005) and MI/Cr (slope 5 0.0041, p 5 0.005) in frontal white matter as well as increases in MI/Cr (slope 5 0.0041, p , 0.001) and NAA/Cr (slope 5 0.0024, p 5 0.030) in parietal gray matter. After initiation of ART, prior positive slopes were no longer significantly different from zero, while Glu/Cr in basal ganglia decreased (slope 5 20.0038, p 5 0.031). Conclusions: Early in HIV infection, increases of Cho/Cr and MI/Cr in treatment-naive participantssuggest progressive inflammation and gliosis in the frontal white matter and parietal gray matter, which is attenuated after initiation of ART. Elevated baseline Glu/Cr in basal ganglia may signal excitotoxicity; its subsequent stabilization and downward trajectory with ART may lend further support for early ART initiation. Neurology ® 2014;83:1592-1600 GLOSSARY ART 5 antiretroviral therapy; CHI 5 chronic HIV infection; Cho 5 choline-containing metabolites; Cr 5 creatine-containing metabolites; Glu 5 glutamate; 1 H-MRS 5 proton magnetic resonance spectroscopy; IQR 5 interquartile range; MI 5 myoinositol; MPRAGE 5 magnetization-prepared rapid gradient echo; MR 5 magnetic resonance; NAA 5 N-acetylaspartate; PHI 5 primary HIV infection; TCA 5 tricarboxylic acid; TE 5 echo time; VOI 5 volume of interest.Proton magnetic resonance spectroscopy ( 1 H-MRS) can detect dynamic cerebral metabolite changes indicative of inflammation and neuronal injury in individuals with HIV.

A methodology for the design and optimization of a composite wind turbine tower for use on a floating offshore platform is presented. A composite turbine tower on a floating offshore platform not only has the potential to reduce maintenance and upkeep costs associated with the use of steel offshore but also has potential to reduce the tower mass and subsequently the support platform mass. The optimization problem is formulated to obtain a turbine tower that meets all strength and serviceability criteria and minimizes the tower mass. The optimization and design process link a number of dynamic analyses and finite element routines using a genetic algorithm. This work documents the optimization and design software and illustrates its use in various case studies for a 6 MW floating wind turbine system. Case studies include the optimization of a steel tower as a comparison to a composite material tower and the use of a cored, sandwich panel composite tower versus a solid composite tower. The results demonstrate that significant reductions in the tower mass are likely when comparing a steel tower with a composite tower. Also demonstrated for the platform and turbine configuration considered in this work is that the minimum mass tower design is driven towards a solid shell composite configuration, rather than a sandwich panel tower shell, in the face of reasonable design constraints.