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Background/Objectives: Light therapy has emerged as a promising non-pharmacological treatment for depressive symptoms. This meta-analysis aims to evaluate the effectiveness of light therapy specifically for depressive symptoms in elderly populations, with a focus on how different light intensities and spectra influence treatment outcomes. Methods: A systematic search targeting studies on light therapy for depressive symptoms in older adults was performed across multiple databases, including PubMed, Google Scholar, PsycINFO, and EMBASE, covering studies from database inception until July 2024. A total of 565 records were identified, with 461 studies remaining after removing duplicates. Following the screening of titles and abstracts, 54 studies underwent full-text review, resulting in the inclusion of 22 studies with a total of 1290 participants (687 in the intervention group and 603 in the control group). Results: The overall effect size for light therapy on depressive symptoms was moderate (Hedges' g = 0.525, p < 0.001). Higher light intensities (10,000 lux and above) demonstrated significantly greater effectiveness compared to lower intensities. White light had the most substantial effect, while bluish light showed moderate efficacy. Significant heterogeneity was observed across studies (I2 = 80.459%), indicating variability in treatment outcomes based on study design, intensity, and light spectrum. Conclusions: This meta-analysis confirms that light therapy is an effective treatment for reducing depressive symptoms in older adults, particularly at higher intensities and with specific light spectra such as white light. Given the heterogeneity in results, future research should focus on optimizing treatment parameters to enhance clinical outcomes within this population. [ABSTRACT FROM AUTHOR]

Photothermal imaging is useful for detecting individual nanoparticles and obtaining the absorption spectra. This study presents a wide-field photothermal reflectance spectroscopy technique achieved by incorporating a pump beam, a probe beam, and a charge-coupled device (CCD) camera into a commercial microscopic setup. The presented design does not require precise alignment between the pump and the probe beams and enables the observation of numerous individual nanoparticles during image acquisition. Despite the use of a simple imaging processing method, i.e., a four-bucket method using a CCD camera, sufficient sensitivity for the spectral imaging of a single gold nanorod (20 nm diameter and 84 nm length) is demonstrated. Numerous individual nanoparticles within a wide field of view (240 μm × 180 μm) are detected in an image captures at an imaging measurement speed of 0.02 mm2 min−1. Furthermore, the proposed photothermal reflectance spectroscopy technique can detect the variation in the absorption peak of the measured spectra depending on the aspect ratio of individual nanoparticles within a spectral resolution of 1 nm.

This study presents a straightforward, efficient dual-mode thermoreflectance microscopy (TRM) system for analyzing the stationary and dynamic thermal properties of microelectronic devices. The proposed TRM system employs a standard visible microscope and implements two distinct imaging process schemes to obtain thermal images at different time scales. For TRM imaging of an ohmic microdevice, the optimal probing wavelength is predetermined from the thermoreflectance spectrum, acquired using a white light-emitting diode source and tunable bandpass filters to enhance thermal sensitivity. Thermoreflectance images are obtained in both stationary and transient modes using a four-bucket method and a pulsed boxcar averaging method, respectively. This thermography approach demonstrates highly sensitive, time-integrated stationary thermal imaging and time-gated transient thermal imaging with a temporal resolution of 200 ns. The system shows significant potential as an analytical tool with a sub-micron spatiotemporal resolution for evaluating heat generation and self-heating behavior in microelectronic devices. [ABSTRACT FROM AUTHOR]

Hypothalamic pro-opiomelanocortin (POMC) neurons promote satiety. Cannabinoid receptor 1 (C[B.sub.1]R) is critical for the central regulation of food intake. Here we test whether C[B.sub.1]R-controlled feeding in sated mice is paralleled by decreased activity of POMC neurons. We show that chemical promotion of C[B.sub.1]R activity increases feeding, and notably, C[B.sub.1]R activation also promotes neuronal activity of POMC cells. This paradoxical increase in POMC activity was crucial for C[B.sub.1]R -induced feeding, because designer-receptors-exclusively-activated-by-designer-drugs (DREADD)-mediated inhibition of POMC neurons diminishes, whereas DREADD-mediated activation of POMC neurons enhances C[B.sub.1]R-driven feeding. The Pomc gene encodes both the anorexigenic peptide a-melanocyte-stimulating hormone, and the opioid peptide β-endorphin. C[B.sub.1]R activation selectively increases β-endorphin but not α- melanocyte-stimulating hormone release in the hypothalamus, and systemic or hypothalamic administration of the opioid receptor antagonist naloxone blocks acute C[B.sub.1]R -induced feeding. These processes involve mitochondrial adaptations that, when blocked, abolish C[B.sub.1]R -induced cellular responses and feeding. Together, these results uncover a previously unsuspected role of POMC neurons in the promotion of feeding by cannabinoids., Feeding behaviour is under the control of hypothalamic circuits (1). In the hypothalamic arcuate nucleus (ARC), Agouti-related peptide (AgRP)expressing neurons, when activated, promote food intake (2,3), whereas POMC-producing neurons promote [...]