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This paper addresses the inherent limitations in traditional color modeling techniques for measuring the flame equivalence ratio (Φ), particularly focusing on the subjectivity involved in threshold settings and the challenges posed by uneven 2D color distribution. To overcome these issues, this study introduces an attention-based convolutional neural network (ACN) model, a novel approach that transcends the conventional reliance on B/G color features (Tf). The ACN model leverages adaptive feature extraction, augmented by a spatial attention mechanism, to more effectively analyze flame images. By amplifying key features, autonomously minimizing background noise, and standardizing variations in color distribution, the ACN model in this experiment achieved a prediction accuracy of 99%, with a 76% reduction in error rate compared to the original model, significantly improving the accuracy and objectivity of flame Φ measurement. This method marks a substantial development in the precision and reliability of flame analysis. [ABSTRACT FROM AUTHOR]

Objective: We aimed to test whether region‐specific factors, including spatial expression patterns of the tau‐encoding gene MAPT and regional levels of amyloid positron emission tomography (PET), enhance connectivity‐based modeling of the spatial variability in tau‐PET deposition in the Alzheimer disease (AD) spectrum. Methods: We included 685 participants (395 amyloid‐positive participants within AD spectrum and 290 amyloid‐negative controls) with tau‐PET and amyloid‐PET from 3 studies (Alzheimer's Disease Neuroimaging Initiative, 18F‐AV‐1451‐A05, and BioFINDER‐1). Resting‐state functional magnetic resonance imaging was obtained in healthy controls (n = 1,000) from the Human Connectome Project, and MAPT gene expression from the Allen Human Brain Atlas. Based on a brain‐parcellation atlas superimposed onto all modalities, we obtained region of interest (ROI)‐to‐ROI functional connectivity, ROI‐level PET values, and MAPT gene expression. In stepwise regression analyses, we tested connectivity, MAPT gene expression, and amyloid‐PET as predictors of group‐averaged and individual tau‐PET ROI values in amyloid‐positive participants. Results: Connectivity alone explained 21.8 to 39.2% (range across 3 studies) of the variance in tau‐PET ROI values averaged across amyloid‐positive participants. Stepwise addition of MAPT gene expression and amyloid‐PET increased the proportion of explained variance to 30.2 to 46.0% and 45.0 to 49.9%, respectively. Similarly, for the prediction of patient‐level tau‐PET ROI values, combining all 3 predictors significantly improved the variability explained (mean adjusted R2 range across studies = 0.118–0.148, 0.156–0.196, and 0.251–0.333 for connectivity alone, connectivity plus MAPT expression, and all 3 modalities combined, respectively). Interpretation: Across 3 study samples, combining the functional connectome and molecular properties substantially enhanced the explanatory power compared to single modalities, providing a valuable tool to explain regional susceptibility to tau deposition in AD. ANN NEUROL 2024;95:274–287 [ABSTRACT FROM AUTHOR]

In this work, a focused ultrasonic radiator is proposed for cooling the electrical heating elements in the focal region, and its working characteristics are investigated. The analyses of the FEM computational and flow field visualization test results indicate that focused ultrasound can generate forced convective heat transfer by the acoustic streaming in the focal region, which can cool the heating elements effectively. Experiments show that when the input voltage is 30Vp-p and the ambient temperature is 25 °C, the focused ultrasonic radiator can cause the surface temperature of the heating element (high-temperature alumina ceramic heating plate with a diameter of 5 mm) in the focal region to drop from 100 °C to about 55 °C. When the diameter of the electrical heating element is changed from 5 mm to 30 mm, the cooling effect is similar in the focal region. Compared with a fan, the focused ultrasound radiator has a shorter cooling time and a more concentrated cooling area. The focused ultrasonic radiator proposed in this work is suitable for some special environments. [ABSTRACT FROM AUTHOR]

Background: In clinical trials, an important question is which brain regions show high tau accumulation within 1‐2 years. Building upon our previous epicenter‐connectivity‐based distance model for predicting the progression of tau‐PET accumulation from initial seed regions of high tau (epicenters) to other regions (Franzmeier et al. Sci Adv. 2020), we incorporate here epicenter‐based distance within spatial gradients of gene expression and amyloid‐PET to enhance the predictive power. Method: We included 351 participants encompassing Ab(+) non‐demented subjects (controls & MCI), characterized by cross‐sectional 11‐F florbetaben amyloid‐PET and longitudinal 11‐F flortaucipir tau‐PET (longitudinal, n = 172, mean/range = 1,7 yrs (0.7 – 5.2 yrs)) from ADNI. For transcriptomic gene expression maps obtained from the Allen Human Brain Atlas, we computed for each of the 18,686 genes maps spatial correlations with the average tau‐PET map in a randomly selected training sample (n = 106), and retained the top 5% of positively/inversely tau‐correlating gene maps. For each imaging modality, spatial gradients were subsequently computed across amyloid‐PET scans in the training sample, the subset of gene expression maps, and functional connectivity (FC) matrices from Human Connectome project. In the test sample (n = 245), tau‐PET epicenters at baseline (Franzmeier et al. Sci Adv 2020) were projected onto the gradient maps and epicenter‐based gradient distance was computed. In step‐wise spatial regression analyses, we tested which gradient distances predicted the spatial patterns of cross‐sectional and longitudinal tau‐PET accumulation, accounting for spatial autocorrelations. Result: For cross‐sectional tau‐PET (Fig. 1A), a total of 54.6% (p < 0.0001) of the spatial tau pattern could be explained, where an amyloid‐PET gradients and a FC gradient (spanning the transmodal axis from primary sensory to DMN regions) showed the strongest effects (Fig. 2, upper row & Fig. 3A). For longitudinal tau‐PET (Fig. 1B), a total of 47.8% (p < 0.0001) of tau increases could be explained, where gene‐expression gradients showed the strongest effects (Fig. 2 lower row & Fig. 3B). Conclusion: Epicenter‐based gradient distances of connectivity and molecular brain properties show additive, high predictive accuracy for predicting regions of high future tau‐accumulation, providing an attractive approach to define tau‐PET outcome ROIs in clinical trials. [ABSTRACT FROM AUTHOR]

In recent years, piezoelectric actuators, represented by inertial and inchworm actuators, have been widely applied because of their high accuracy and excellent responsiveness. Despite the development of various piezoelectric actuators, there remain some flaws in this technology. The sticking point is that the piezoelectric actuators based on the friction driving principle are prone to unwanted backward motion when outputting stepping motion. It is thus urgent to explore solutions from the perspectives of principle and structure. In this paper, a clamping-drive alternating operation piezoelectric actuator is proposed, the two feet of which are driven by two piezoelectric stacks, respectively. Due to double-foot alternate drive guide movement, backward movement is prevented in theory. By adopting the double-layer stator structure, integrated processing and assembly are facilitated. Meanwhile, a double flexible hinge mechanism is installed in the stator to prevent the drive foot from being overturned due to ineffectiveness and premature wear. In addition, the stator is equipped with the corresponding preload mechanism and clamping device. After the cycle action mechanism of one cycle and four steps is expounded, a model is established in this study to further demonstrate the principle. With the prototype produced, a series of experiments are performed. In addition, the amplitude of actuation of the stator is tested through amplitude experiment. The performance of the stator is evaluated by conducting experiments in the alternating step and single step actuation modes. Finally, the test results are analyzed to conclude that the actuator operating in either of these two modes can meet the practical needs of macro and micro actuation. [ABSTRACT FROM AUTHOR]

Background: It is unclear whether miR-491-5p, miR-206, miR-21-5p or miR-3123 are associated with functional outcomes and hemorrhagic transformation (HT) after acute ischemic stroke (AIS). In this study, we aimed to investigate the correlation between these four microRNAs and functional outcomes, as well as spontaneous HT after AIS; Methods: We included 215 AIS patients and retrospectively assayed for miR-21-5p, miR-206, miR-3123 and miR-491-5p levels in serum. Poor functional outcome was defined as a modified Rankin Scale score ≥ 3. Spontaneous HT referred to hemorrhage detected in follow-up brain imaging but not on admission, without reperfusion therapies. Logistic regression, generalized additive model and 2-piecewise regression model were used to explore the independent, non-linear correlation between miRNA expression levels and outcomes; Results: We included 215 AIS patients. Higher miR-491-5p level independently reduced the risk of poor functional outcomes at 1 year (OR 0.90, 95% CI 0.82–0.98, corrected p value = 0.044). Higher miR-206 level significantly increased the risk of spontaneous HT (OR 1.64, 95% CI 1.17–2.30, corrected p value = 0.016). There was a nonlinear correlation found between miR-491-5p level and 1 year outcome with an inflection point of 2.180, while an approximately linear correlation was observed with an inflection point of 2.037 between miR-206 level and spontaneous HT; Conclusions: Higher serum miR-491-5p level independently reduced risk of 1-year poor functional outcome of AIS patients. Higher serum miR-206 level independently increased the risk of spontaneous HT in AIS patients. These two miRNAs may be as the potential biomarkers for improving prognosis after AIS. [ABSTRACT FROM AUTHOR]

Background: Myelin is the cholesterol‐rich layer ensheathing axons in the white matter (WM). The APOE ε4 allele has been associated with both reduced cholesterol transport to myelin layers in mice and with faster tau progression in individuals with AD. Here we asked the questions whether 1) APOE ε4 is associated with lower myelin and 2) any myelin decreases mediate the association between APOE ε4 and the rate of tau‐PET accumulation in Aβ+ individuals. To assess myelin, we repurposed florbetapir‐PET tracer binding, previously shown to be sensitive to myelin binding protein in the WM (Stankow et al. Annals Neurol 2011). Method: We included 43 Aβ‐ cognitively normal (CN, global florbetapir SUVR < 1.11) and AD‐spectrum participants (56 CN Aβ+, 32 MCI Aβ+, and 20 AD Aβ+) from ADNI. To extract individual myelin levels, we averaged each participant's florbetapir SUVR within individual T1‐MRI based WM masks (global myelin) or 58 fiber‐tracts generated from multishell DTI (fiber‐tract myelin). To control for a putative influence by grey‐matter florbetapir levels, we adjusted the individual WM‐florbetapir SUVRs for grey‐matter florbetapir SUVR via linear regression analysis and computed z‐scores of the adjusted WM‐florbetapir SUVRs across all participants (Moscoso et al. EJNNMI, 2022). For tau‐PET, flortaucipir SUVRs were extracted in Braak‐stage GM ROIs or in the tracts' cortical projection zones, and mixed effect linear regression was used to estimate the rate of regional flortaucipir change. Result: Higher APOE ε4 score was associated with both lower WM‐florbetapir z‐score (β = ‐0.329, p<0.001) and faster tau‐PET increase in Braak stage 3+4 ROIs (β = 0.224, p = 0.01) in Aβ+ participants (Fig. 1A&B). Using bootstrapped mediation analysis, we found that the WM‐florbetapir z‐score mediated the effect of APOE dosage on the rate of tau‐PET accumulation in Braak 3+4 (b = 2´10‐4 [95% CI: 2´10‐5, 3´10‐4], p = 0.02, Fig 1C). At the fiber‐tract level, APOE ε4 dosage exacerbated the association between decreased fiber‐tract florbetapir and faster tau‐PET increase in the tracts' projection zones (p<0.001). Conclusion: APOE ε4 may contribute to the accumulation of tau pathology in a myelin dependent manner. Myelin impairment is treatable by several known drugs and therefore an attractive therapeutic target in AD. [ABSTRACT FROM AUTHOR]

Objective: To study the relationship between cerebral small vessel disease (CSVD) and hematoma volume in mixed‐location intracerebral hemorrhage (ICH), and non‐mixed ICH (hypertensive arteriopathy/cerebral amyloid angiopathy‐related ICH). Methods: We consecutively collected patients with primary ICH with MRI. Mixed‐location ICH was defined as having ICH or cerebral microbleeds (CMBs) in both lobar and deep regions. CSVD markers including lacunes, white matter hyperintensities (WMH), CMBs, and enlarged perivascular spaces (EPVS) were assessed on brain MRI during hospitalization. Multivariable binary logistic regression (≥30 ml vs. <30 ml) and linear regression analyses (log‐transformed hematoma volume as dependent variable) were implemented to explore the association between CSVD and hematoma volume. Results: Of the 167 included patients, 69 (41.3%) had mixed‐location ICH, with higher prevalence of lacune, more CMB count, higher WMH score and total CSVD score than those with non‐mixed ICH (all p <.001). Higher WMH score was associated with lower risk of hematoma volume ≥30 ml (adjusted OR 0.521, 95% CI 0.299–0.908, p =.021) in patients with mixed‐location ICH. Also, multivariable linear regression showed the association of smaller hematoma volume with higher CSVD burden, especially in mixed‐location ICH (β = −0.349, p =.019 for CMB ≥ 5; β = −0.183, p <.001 for WMH score; β = −0.456, p =.002 for EPVS>20 in basal ganglia and/or centrum semiovale; β = −0.256, p =.002 for CSVD score), while these relationships were not observed in non‐mixed ICH. Conclusions: Higher CSVD burden is associated with smaller hematoma volume in mixed‐location ICH, but not in non‐mixed ICH, which is novel and needs further studies with larger sample size to confirm our results and explore the underlying mechanisms. [ABSTRACT FROM AUTHOR]

To evaluate whether genotype-guided antiplatelet therapy reduces the rates of cardiovascular events and bleeding events in patients with acute coronary syndrome (ACS). We systematically searched Pubmed, Embase and the Cochrane Central Register of Controlled Trials (CENTRAL) (searched in September 2018) for controlled studies evaluating genotype-guided antiplatelet therapy in ACS with percutaneous coronary intervention (PCI) or without PCI. The primary endpoint was a composite of death, myocardial infarction (MI), stroke, targeted vessel revascularization and/or major bleeding. A total of five studies involving 2900 patients were included. Compared with the conventional group, the genotype-guided group had a decreased risk of primary composite outcomes (RR= 0.54; 95% CI: 0.41–0.72; I2 = 30%), death (RR = 0.54; 95% CI: 0.32–0.94; I2 = 21%), MI (RR = 0.52; 95% CI: 0.31–0.88; I2 = 49%), targeted vessel revascularization (RR = 0.59; 95% CI: 0.35–0.98; I2 = 0%), but not for stroke (RR = 0.53; 95% CI: 0.22–1.24; I2 = 0%) and bleeding events (RR = 0.80; 95% CI: 0.51–1.25; I2 = 33%). Genotype-guided strategies could reduce the rates of cardiovascular events without increasing bleeding events compared with conventional treatment in ACS. Future multi-centre genotype-based randomized control trials are required to confirm these findings. [ABSTRACT FROM AUTHOR]

The flame chemiluminescent emission fluctuations and the vortex structure of the lifted jet flame under acoustic excitation were studied in this investigation. By employing high-speed visualization and DFCD (Digital Flame Colour Discrimination) image processing method, the fluctuation of the instantaneous mixture fraction has been found highly correlated with the lifted height variations. It has been observed that during the flame drifting to downstream, there is no obvious shifting on the mixture fraction. However, when the flame travels back to upstream, the fuel mixture has been evidently diluted. In addition, the stabilisation mechanism can be further explained by analysing the velocity fluctuation of the vortices in the shear layer via PIV. Measurements show that, the turbulent stretching at the shear layer generated by the excitation leading to the flame lift-off. On the other hand, the Kelvin-Helmholtz vortices in the unburn part play a key role in preventing flame lift-off. But, the excessive external acoustic excitation leads to blow-off due to over dilution and increased lifted height. [ABSTRACT FROM AUTHOR]

Background: Serum albumin level is associated with infection after stroke, but whether albumin predicts post-stroke pneumonia is unclear. The potential relationship between albumin level and pneumonia in patients with acute ischemic stroke (AIS) was evaluated in this study., Methods: A consecutive sample of 798 AIS patients who were admitted to West China Hospital within 24 h after onset, from the year 2017 to 2018, were retrospectively analyzed. Blood was collected on admission and assayed for serum albumin. Univariate analyses, multivariate logistic regression, and stratified logistic regression were performed to identify the risk factors of post-stroke pneumonia., Results: Out of the 798 patients, 240 (30.2%) developed pneumonia at a median of 48 h after onset (interquartile range, 27-74 h). Patients with pneumonia had significantly lower serum albumin levels than those without pneumonia (40.6 vs. 42.9 g/l, p<0.001). After adjustment, the albumin level was still significantly associated with pneumonia in multivariate logistic regression (odds ratio [OR] 0.87, 95% confidence interval [CI] 0.81-0.94). The association between serum albumin and pneumonia tended to depend on National Institutes of Health Stroke Scale score (p = 0.045), but this was significant only in patients with mild stroke (OR 0.84, 95% CI 0.77-0.93). A dosedependent inverse relationship was found between albumin levels and the risk of pneumonia after AIS. Albumin values predicted pneumonia with an area under the curve of 0.661 (95% CI 0.620- 0.701), and the optimal cutoff was 42.6 g/L., Conclusion: Low serum albumin levels may be independent predictors of pneumonia in patients with AIS, especially in mild stroke. In fact, the risk of pneumonia may vary inversely with albumin level., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Studies suggest that microRNAs that regulate expression of matrix metalloproteinase (MMP)-9 may be involved in hemorrhagic transformation (HT) after cardioembolic stroke, so we examined whether such microRNAs could predict HT in acute cardioembolic stroke patients. Blood samples were prospectively collected from patients who later experienced HT ( n = 29) or did not ( n = 29), and the samples were assayed for eight microRNAs identified as related to MMP-9 based on three microRNA databases. Expression levels of these microRNAs were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) in 28 of the 58 patients, 14 of whom suffered HT and 14 of whom did not. Four differentially expressed miRNAs were identified: hsa-miR-21-5p, hsa-miR-206, hsa-miR-491-5p , and hsa-miR-3123 . Subsequent qRT-PCR analysis of these four miRNAs across all 58 patients showed that levels of miR-21-5p, miR-206 , and miR-3123 were significantly higher in patients with HT than in those without HT, while expression of miR-491-5p was similar between the two groups. The area under the receiver operating characteristic curve for predicting HT was 0.677 (95% CI 0.535-0.818) for miR-21-5p , 0.687 (95% CI 0.543-0.830) for miR-206 , and 0.661 (95% CI 0.512-0.810) for miR-3123 . Our results suggest that these three microRNAs may be prognostic markers for HT after cardioembolic stroke, which should be verified by future studies with large samples.