Optical alignment and optical orientation of excitons are studied experimentally on an ensemble of core/shell CdSe/CdS colloidal nanoplatelets. Linear and circular polarization of photoluminescence during resonant excitation of excitons is measured at cryogenic temperatures and with magnetic fields applied in the Faraday geometry. The developed theory addresses the optical alignment and optical orientation of excitons in colloidal nanocrystals, taking into account both bright and dark exciton states in the presence of strong electron-hole exchange interaction and the random in-plane orientation of nanoplatelets within the ensemble.
View Article and Find Full Text PDFβ-Amyloid (Aβ) plaques can trigger chronic inflammation in the cellular environment that recruits infiltrating macrophages during the course of Alzheimer disease (AD). Activated macrophages release pro-inflammatory cytokines that increase neurotoxicity associated with AD. A major impediment to investigating neuroinflammation involving macrophage activity is the inability to discriminate resident microglial macrophages (mMϕ) from hematogenous macrophages (hMϕ), as they are morphologically and phenotypically similar when activated.
View Article and Find Full Text PDFSpinal cord injury (SCI) causes sexual dysfunction, including anejaculation in men. Likewise, chronic mid-thoracic contusion injury impairs ejaculatory reflexes in male rats. Ejaculation is controlled by a spinal ejaculation generator (SEG) comprised of a population of lumbar spinothalamic (LSt) neurons.
View Article and Find Full Text PDFSpinal Cord Ser Cases
February 2017
Introduction: The objective of this study was to assess the feasibility of the use of functional magnetic resonance imaging (fMRI) to evaluate the spinal activation during sexual response of the thoracic, lumbar and sacral spinal cord.
Materials And Methods: This is a laboratory-based pilot study in human females at a University-based medical center in the United States. In three healthy spinal cord injury (SCI) females, spinal cord activations during sexual audiovisual stimulation (alone), genital self-stimulation (alone) and simultaneous audiovisual and genital self-stimulation (combined) were assessed and then compared with each subjects' remaining sensory and motor function.
The spinal ejaculation generator is comprised of lumbar spinothalamic (LSt) cells and their axonal projections to autonomic and motor neurons in the lumbosacral spinal cord. LSt cells regulate ejaculatory reflexes by release of neuropeptides that are co-expressed in their axons, as previously demonstrated for gastrin-releasing peptide and enkephalin. Here, the role of two other neuropeptides co-expressed in LSt cells for ejaculatory reflexes is demonstrated: galanin and cholecystokinin (CCK).
View Article and Find Full Text PDF