PubMed · 1872479
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
A R Newman. 1991-05-15. Electronic noses.. https://doi.org/10.1021/ac00010a735
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
Understanding electronic communication among the constituents in multicomponent macromolecular architectures is essential for the rational design of molecular devices for photonic, electronic, or optoelectronic applications. This Account describes studies aimed at understanding the mechanisms of electronic communication in porphyrin-based architectures that undergo excited-state energy migration and ground-state hole/electron hopping. Porphyrins are ideal building blocks for such constructs owing to their attractive and versatile physical properties and amenability to synthetic control. These properties have permitted the creation of covalently linked multiporphyrin arrays wherein the rates of excited-state energy migration and ground-state hole/electron hopping can be tuned over a wide range.
Studies of human perception of time-varying luminance often aim to estimate either temporal impulse response shapes or temporal modulation transfer functions (MTFs) of putative temporal processing mechanisms. Previously, temporal masking data have been used to estimate the properties and numbers of these temporal mechanisms in central vision for 1 cycle per degree (cpd) targets [Fredericksen and Hess (1998)]. The same methods have been used to explore how these properties change with stimulus energy [Fredericksen and Hess (1997)] and spatial frequency [Fredericksen and Hess (1999)]. We present here analyses of the properties of temporal mechanisms that detect temporal variations of luminance in peripheral vision. The results indicate that a two-filter model provides the best model for our masking data, but that no multiple filter model provides an acceptable fit across the range of parameters varied in this study. Single-filter modelling shows differences between processing mechanisms at 1 cpd in central vision and those that operate eccentrically. We find evidence that this change is because of differences in relative sensitivities of the mechanisms, and to differences in fundamental mechanism impulse responses.
Following an analysis of the literature, this article reviews the current practices, guidelines, and recommendations for electronic fetal monitoring of the preterm fetus. The physiologic aspects of fetal heart rate control, electronic fetal monitor parameters, and differences between the preterm and term fetus are discussed. Clearly identified is the need for clinical research regarding electronic fetal monitoring of the preterm fetus to establish evidence-based practice guidelines.