Abstract: The performance of the ring laser gyroscope (RLG) can be affected by variations of the optical path length, due to temperature change and other operation environment factors. This paper focuses on the optimization of the path length control (PLC) transducer to get the largest displacement of the grooved mirror by the finite element method (FEM). To verify the analysis results, a mode-scanning experiment is carried out. The experimental result shows agreement with that of the FEM analysis. We show that a careful selection of material and geometry parameters allows the displacement amplitude to be maximized as 6.48 μm, a value…that is 3 times the displacement in the existing structure. A minimization of the number of mode reset is achieved, leading to an improvement of RLG performance.
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Keywords: Ring laser gyroscope, path length control transducer, piezoelectric actuator, design optimization, finite element analysis
Abstract: Background: CC-chemokine ligand 2 (CCL2), the key immunomodulatory chemokine for microglial activation, has been implicated in the pathogenesis of Alzheimer’s disease (AD). Whether the association of CCL2 single nucleotide polymorphisms (SNPs) and the risk of AD is still controversial. Objective: We aimed to investigate whether CCL2 rs4586 SNP is associated with the pathological changes and cognitive decline of AD. Methods: A total of 486 participants with longitudinal cerebrospinal fluid (CSF) amyloid-β (Aβ) and phospho-tau (P-tau) biomarkers, 18 F-Florbetapir and 18 F-flortaucipir-positron emission tomography (PET), and cognitive assessments from the Alzheimer’s disease Neuroimaging Initiative were included in the study. The effects…of CCL2 rs4586 SNP on the pathological changes and cognitive decline of AD were assessed with linear mixed-effects models and evaluated according to the Aβ-status so as to identify whether the effects were independent of Aβ status. Results: CCL2 rs4586-CC carriers exhibited a slower global Aβ-PET accumulation, particularly within stage I and stage II. However, they exhibited a faster accumulation of CSF P-tau and global tau-PET standard uptake value ratios, especially in Braak I and Braak III/IV and the inferior temporal gyrus. The congruent effects of CCL2 rs4586 on tau accumulation existed only in the Aβ–group, as is shown in global tau-PET and Braak I. However, CCL2 rs4586 was not associated with the cognitive decline. Conclusion: Our findings showed that the CCL2 rs4586-CC (versus TT/TC) genotype was associated with slower Aβ deposition and faster tau accumulation, and the latter of which was independent of Aβ status.
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Keywords: Alzheimer’s disease, Alzheimer’s Disease Neuroimaging Initiative, amyloid-β, CCL2, tau
Abstract: Background: Inflammation plays a role in occurrence and progression of Alzheimer’s disease (AD). Whether peripheral immune cells are involved in major pathological processes including amyloid-β plaques and tau tangles is still controversial. Objective: We aimed to examine whether peripheral immune cells counts were associated with early changes in cerebrospinal fluid (CSF) biomarkers of AD pathology in cognitively intact older adults. Methods: This study included 738 objective cognitive normal participants from the Chinese Alzheimer’s Biomarker and Lifestyle (CABLE) database. Group comparisons of peripheral immune cells counts were tested by analysis of covariance. Multiple linear regression models were used to examine the…associations of peripheral immune cells counts with CSF AD biomarkers. Results: In preclinical AD, peripheral lymphocytes and eosinophils changed dynamically along with disease progression. Consistently, regression analysis showed that lymphocytes and eosinophils were associated with Aβ pathology. There were no interaction effects of peripheral immune cells counts with APOE ɛ4, gender, age, and educate. Eosinophil to lymphocyte ratio were also significantly associated with Aβ-related biomarkers. Conclusion: Our findings showed the relationship between peripheral immune cells and Aβ pathological biomarkers, which indicated that peripheral immune might play a role in progression of AD pathology.
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