Objective: To determine the frequency range of a-b wave complex in the dark- and light-adapted electroretinogram (ERG) and to isolate the pure a- and b- waves.
Methods: Case series study. Full-field ERGs were recorded in 16 eyes of 8 normal volunteers from October to November 2011. Digital filtering technique was used to extract the a- and b-waves from dark- and light-adapted ERG responses. The timings of a- and b-wave were measured to determine the frequency range of a-b wave complex. Major frequency components were determined from power spectra using fast Fourier transform (FFT). The effect of different order settings in the digital filter were compared to investigate the optimum condition, where the oscillatory potential (OP) was completely removed while the amplitudes and phases of the a- and b- waves were less affected. The Student-t test was used to compare the frequency range of a-b wave complex in dark- and light-adapted ERG.
Results: The averaged frequency range of the dark-adapted a-b wave complex was from (14.99 ± 2.39) to (25.35 ± 3.77) Hz, compared with (25.22 ± 6.56) to (32.47 ± 3.68) Hz for the light-adapted a-b wave complex, respectively, indicating the frequency range of the dark-adapted a-b wave complex was significantly less than the light-adapted a-b wave complex (t = 7.910, 7.693; both P < 0.01). The third order of the digital filter and a passband of 1 to 45 Hz was the best choice in term of removing the high frequency OP from the waveform of ERG and keeping the amplitude and phase of the a- and b- waves.
Conclusions: The frequency of a-b wave complex is lower than that of OP. Therefore the a- and b- waves can be isolated from OP using different digital filter settings in human ERG. A third order and a passband of 1 to 45 Hz is the best choice to extract pure a- and b- waves from the original ERG.
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Int J Ophthalmol
December 2024
Department of Ophthalmology & Visual Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai 200031, China.
Aim: To investigate the features of retinal ischemic injuries in a novel mouse model with bilateral carotid artery stenosis (BCAS).
Methods: BCAS was induced with microcoil implantation in 6-8-week-old C57BL6 mice. Cerebral blood flow was monitored at 2, 7, and 28d postoperatively.
Int J Biometeorol
December 2024
School of Landscape Architecture, Zhejiang Agricultural and Forestry University, Hangzhou, 311300, China.
The surface color and materials of sidewalk pavements exhibit different albedo characteristics, leading to varied surface urban heat island effects in subtropical regions. To quantify the effect of pavement surface color and material on SUHI, Prefabricated Concrete Structure brick (PCB), Granite brick (GB) and Dutch brick (DB) totaling 14 pavement samples in Hangzhou were placed under unshaded, cloud shaded and tree shaded conditions. CIELAB (International Commission on Illumination L*a*b*) color data, short-wave radiation (incoming and outgoing) and surface temperature were measured.
View Article and Find Full Text PDFCirculation
December 2024
Department of Cardiology (D.T., T.P., J.L., S.W.), Cardiovascular Center, Bern University Hospital, Inselspital, University of Bern, Switzerland.
bioRxiv
December 2024
Department of Ophthalmology, Emory University, Atlanta, Georgia, United States.
Purpose: Pigment epithelium-derived factor (PEDF) is a neurotrophic glycoprotein secreted by the retinal pigment epithelium (RPE) that supports retinal photoreceptor health. Deficits in PEDF are associated with increased inflammation and retinal degeneration in aging and diabetic retinopathy. We hypothesized that light-induced stress in C57BL/6J mice deficient in PEDF would lead to increased retinal neuronal and RPE defects, impaired expression of neurotrophic factor Insulin-like growth factor 1 (IGF-1), and overactivation of Galectin-3-mediated inflammatory signaling.
View Article and Find Full Text PDFMult Scler Relat Disord
November 2024
Buffalo Neuroimaging Analysis Center, Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States; Center for Biomedical Imaging at the Clinical Translational Science Institute, University at Buffalo, State University of New York, Buffalo, NY, United States.
Background: The deep gray matter (DGM), especially the pulvinar, and the white matter surrounding chronic active lesions have demonstrated depleted iron levels, indicating a possible mechanistic link. However, no studies have investigated the potential relationship between these phenomena.
Objectives: The study aimed to determine whether PRLs were associated with pulvinar iron depletion and, if so, whether this relationship was spatially mediated.
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