A new methodology for image sensor modulation transfer function measurement using band-limited laser speckle is presented. We use a circular opal milk glass diffuser illuminated by a 5 mW He-Ne laser and a linear polarizer to generate band-limited speckle on the sensor. The power spectral density cut-off frequency of the speckle is chosen to be twice that of the sensor Nyquist frequency by placing the sensor at the specific Z location along the optical axis. For the speckle input, we calculate the power spectral density at the sensor using the Rayleigh-Sommerfeld integral and then measure the output power spectral density for the speckle pattern captured by the sensor. With these data, the two-dimensional image sensor modulation transfer function (MTF) is calculated.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/oe.16.020047 | DOI Listing |
J Lipid Res
January 2025
Department of Biological Sciences, Kent State University, P.O. Box 5190, Kent, OH 44242, USA. Electronic address:
Phosphatidic acid (PA) through its unique negatively charged phosphate headgroup binds to various proteins to modulate multiple cellular events. To perform such diverse signaling functions, the ionization and charge of PA's headgroup relies on the properties of vicinal membrane lipids and changes in cellular conditions. Cholesterol has conspicuous effects on lipid properties and membrane dynamics.
View Article and Find Full Text PDFRedox Biol
January 2025
Redox Biology Group, Danish Cancer Institute, 2100, Copenhagen, Denmark. Electronic address:
Focal adhesions (FAs), multi-protein complexes that link the extracellular matrix to the intracellular cytoskeleton, are key mediators of cell adhesion, migration, and proliferation. These dynamic structures act as mechanical sensors, transmitting stimuli from the extracellular to intracellular environment activating in this way signaling pathways and enabling cells to adapt to environmental changes. As such, FAs are critical for tissue organization and serve as hubs governing cell spatial arrangement within the organism.
View Article and Find Full Text PDFiScience
February 2025
Jiangsu Key Laboratory of Immunity and Metabolism, Department of Pathogenic Biology and Immunology, Xuzhou Medical University, Xuzhou, Jiangsu, China.
Pattern recognition receptors (PRRs), consisting of Toll-like receptors, RIG-I-like receptors, cytosolic DNA sensors, and NOD-like receptors, sense exogenous pathogenic molecules and endogenous damage signals to maintain physiological homeostasis. Upon activation, PRRs stimulate the sensitization of nuclear factor κB, mitogen-activated protein kinase, TANK-binding kinase 1-interferon (IFN) regulatory factor, and inflammasome signaling pathways to produce inflammatory factors and IFNs to activate Janus kinase/signal transducer and activator of transcription signaling pathways, resulting in anti-infection, antitumor, and other specific immune responses. Palmitoylation is a crucial type of post-translational modification that reversibly alters the localization, stability, and biological activity of target molecules.
View Article and Find Full Text PDFLaser absorption spectroscopy (LAS) is a well-established measurement technique for quantitative chemical speciation in a combustion environment. However, LAS measurement of nitric oxide (NO) in ammonia flames has never been reported in the literature. This is despite the community's recent strong interest in carbon-neutral ammonia combustion and the associated NO formation problem.
View Article and Find Full Text PDFDual-parameter temperature and humidity sensors based on optical fiber sensing have wide applications. Among various optical fiber sensors, surface plasmon resonance (SPR) sensors exhibit excellent sensing sensitivity. To address the bandwidth issue and expand the sensitivity, this paper proposes a multimode fiber-no core fiber (MMF-NCF) SPR sensor.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!