We propose a procedure to deconvolute the spectral power distribution (SPD) of phosphor-converted LEDs (pc-LEDs). The procedure involves a two-step process using multiple Gaussian functions. The first step is a preliminary process to deconvolute an SPD using a pair of Gaussian functions. Using the results from the first step, the second step determines (a) the number of Gaussian functions to be used in the analysis and (b) the initial values and regression domains of the coefficients of each Gaussian function for subsequent multiple-regression operations. Successful deconvolution is confirmed by comparing the values of lumen, correlated color temperature, and color rendering index with the experimental data of cool and warm pc-LEDs. The proposed approach is illustrated to evaluate the yellow-to-blue ratio and the phosphor power conversion efficiency.
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http://dx.doi.org/10.1364/AO.52.001016 | DOI Listing |
Alzheimers Dement
December 2024
Vanderbilt Genetics Institute, Vanderbilt University Medical Center, Nashville, TN, USA.
Background: Genome-wide association studies (GWAS) in Alzheimer's disease (AD) leveraging endophenotypes beyond case/control diagnosis, such as brain amyloid β pathology, have shown promise in identifying novel variants and understanding their potential functional impact. In this study, we leverage two brain amyloid β pathology measurement modalities, PET imaging and neuropathology, to address sample size limitations and to discover novel genetic drivers of disease.
Method: We conducted a meta-analysis on an amyloid PET imaging GWAS (N = 7,036, 35% amyloid positive, 53.
Alzheimers Dement
December 2024
The University of Sydney, Sydney, NSW, Australia.
Background: SMOC1 has recently emerged as one of the most significant and consistent new biomarkers of early Alzheimer's disease (AD). SMOC1 is one of the earliest changing proteins in AD, with SMOC1 cerebrospinal fluid levels increasing 29 years before symptom onset in autosomal dominant AD. Despite this clear association with disease, very little is known about the role of SMOC1 in AD or its function in the brain.
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December 2024
Texas Tech University Health and Sciences Center El Paso, El Paso, TX, USA.
Background: Mitochondria plays a crucial role at synapses in providing synaptic energy, healthy synaptic function, and cognitive functions. Amyloid-beta and phosphorylated tau protein oligomers cause severe mitochondrial defects in Alzheimer's disease (AD), which leads to the lack of synaptic energy and impaired synapse functions in AD. MicroRNAs (miRNAs) present within the mitochondria are involved in multiple mitochondrial activities and mitochondrial function.
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December 2024
Dementia Research Centre, UCL Queen Square Institute of Neurology, London, United Kingdom.
Background: Knowledge of the chemical composition of amyloid plaques and tau tangles at the earlier stages of Alzheimer's disease (AD) pathology is sparse. This is due to limited access to human brain during life and at the earlier stages of AD pathophysiology and technical limitations in quantifying amyloid and tau species at a subcellular level. Understanding the chemical composition of plaques and tangles, how rapidly they grow and what factors drive growth is important for developing and refining therapeutics.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Homi Bhabha National Institute, Mumbai, Maharashtra, India.
Background: Receptor Tyrosine kinase-mediated signaling is indispensable for the cell's normal functioning, the perturbation of which leads to disease conditions. The altered expression and activity of several Receptor Tyrosine kinases (RTKs) are known to regulate the pathophysiology of Alzheimer's disease (AD). However, the mechanistic details remain illusive.
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