Abstract: The frequency modulated continuous wave circular synthetic aperture radar (FMCW CSAR) is a high resolution imaging radar, which plays an important role in target recognition. However, the traditional wave number domain imaging algorithm has a low resolution for the target far from the scene center, which limits its wide applications in CSAR imaging. In this paper, when the targets are sparse or compressible, a circular convolution algorithm based on compressed sensing is proposed to improve the resolution. In the algorithm, the circular convolution and the Fourier transform is used to reduce computation cost. What’s more, the compressed sensing is applied…to improve the imaging resolution for the target far from the scene center, which can effectively avoid the complex calculation of the system kernel function in the traditional wave number domain algorithm. Some simulation results illustrate the effectiveness of the proposed method.
Show more
Abstract: Background: Depression is one of the most common symptoms in patients with dementia. Objective: This meta-analysis aimed to evaluate the effect of light therapy on depression associated with dementia by using a single scale. Methods: Published studies based on the terms including “Dementia”, “depression”, and “Phototherapy” were searched. Web of Science, PubMed, Embase, CiNii, CNKI, Wanfang Database, and China Biology Medicine disc were adopted to collect randomized controlled studies or cross-controlled studies using the Cornell Scale for Depression in Dementia (CSDD) until February 2022. GRADE and Review Manager Version 5.4.1 were employed to assess the risk of bias. A meta-analysis…was conducted by R 4.0.2 software based on the changes in CSDD scores. Results: A total of 1,055 studies were retrieved from the databases, and six studies were included after screening. Some 406 people with dementia were included with an average age of over 80 years. Forest plot results showed that light intervention improved depression scores of dementia patients (MD = –2.59, 95% CI: –4.46 to –0.71), and light intensity less than 1,000 lux improved depression symptoms of dementia patients (MD = –2.76, 95% CI: –4.55 to –0.97). An intervention that lasted 8 to 12 weeks was the most effective (MD = –3.77, 95% CI: –6.93 to –0.60), and non-stable interventions such as ceiling LED lights exerted more positive effects (MD = –2.12, 95% CI: –3.38 to –0.85). Conclusion: The overall results of the meta-analysis suggested that light intervention can improve the depressive symptoms of older patients with dementia.
Show more
Keywords: Alzheimer’s disease, cornell scale for depression in dementia, dementia, depression, light therapy, older patients
Abstract: Background: The associations between sleep characteristics and cognition are complicated. Alzheimer’s disease (AD) pathologies have been proven to be associated with sleep characteristics. Objective: We aimed to investigate the associations between sleep characteristics and cognitive function and examine the roles of AD pathologies in modulating the association of sleep duration with cognition. Methods: A total of 974 participants who had measurements of cerebrospinal fluid (CSF) amyloid-β (Aβ), phosphorylated tau (P-tau), total tau proteins (T-tau), cognitive function, and sleep characteristics were included from the Chinese Alzheimer’s Biomarker and Lifestyle (CABLE) study. Linear regression analyses were utilized to explore the associations of…sleep characteristics with cognition. Non-linear regression analyses were utilized to explore the associations of sleep habits with cognition. Causal mediation analyses were conducted to explore the mediation effects of AD pathologies on cognition. Results: The Pittsburgh Sleep Quality Index (PSQI) total score was significantly negatively correlated with Montreal Cognitive Assessment (MoCA) score (p = 0.0176). Long latency (p = 0.0054) and low efficiency (p = 0.0273) were associated with cognitive impairment. Habitual nap behavior was associated with lower MoCA scores (p = 0.0045). U-shaped associations were observed between sleep habits (bedtime and nocturnal sleep duration) and cognition. A causal mediation analysis indicated that P-tau/Aβ42 mediated the association of sleep duration with cognition. Conclusion: These findings showed sleep characteristics were associated with cognitive functions. Sleep habits (duration, bedtime) had U-shaped associations with cognition. AD core pathologies might partially mediate the influence of sleep duration on cognitive impairments.
Show more
Keywords: Alzheimer’s disease, cerebrospinal fluid, cognition, montreal cognitive assessment, sleep