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High precision roll-to-roll processes are believed to be one of the most promising technologies for manufacturing flexible and large-area thin film electronics. However, broadband frictional disturbances caused by the guiding ball bearings affect the precision of the processing roller in the roll-to-roll system, severely hampering the quality of the manufactured products. Conventional feedback control techniques encounter difficulties in mitigating the broadband frictional disturbances. This paper presents a novel rotary system for high-precision roll-to-roll manufacturing process. Friction isolator (FI), a robust and cost-effective mechatronics method, is implemented in the system to mitigate the undesirable effects of friction during continuous printing processes. Frequency domain analysis shows that the proposed rotary system with FI achieves significantly improved attenuation of frictional disturbance, compared to the case without it. A rotary FI is designed and optimized to minimize the adverse effects of bearing friction without overly sacrificing the high rigidity of the machine. A precision rotary system is then built using the designed FI prototype. Experiments carried out on the prototype friction-isolated rotary system demonstrate up to 61% reduction in root-mean-square tracking error during constant velocity motion, compared to a conventional roll-to-roll system without FI.

Objective Alzheimer’s disease (AD) is the most common type of dementia and the prevalence rapidly increased as the elderly population increased worldwide. In the contemporary model of AD, it is regarded as a disease continuum involving preclinical stage to severe dementia. For accurate diagnosis and disease monitoring, objective index reflecting structural change of brain is needed to correctly assess a patient’s severity of neurodegeneration independent from the patient’s clinical symptoms. The main aim of this paper is to develop a random forest (RF) algorithm-based prediction model of AD using structural magnetic resonance imaging (MRI).Methods We evaluated diagnostic accuracy and performance of our RF based prediction model using newly developed brain segmentation method compared with the Freesurfer’s which is a commonly used segmentation software.Results Our RF model showed high diagnostic accuracy for differentiating healthy controls from AD and mild cognitive impairment (MCI) using structural MRI, patient characteristics, and cognitive function (HC vs. AD 93.5%, AUC 0.99; HC vs. MCI 80.8%, AUC 0.88). Moreover, segmentation processing time of our algorithm (

In this paper, the development of an ultra-precision XY nanopositioning stage is presented. For system structure, the actuator decoupled parallel compliant mechanism is designed to have the same dynamics in both x- and y-direction so that the coupling crosstalk between two axes can be minimized. Throughout the simulation validation of the deformed XY stage, the motion in the x-axis is not transferred to the motion in the y-axis. For the control structure, the simplified feedforward compensator provides the piezoelectric actuator to reduce the control effort of the system. A proportional double integral (PII) feedback controller is used to minimize the ramp-like disturbances so that the compensation of hysteretic nonlinearity and other disturbances can be effectively reduced. Moreover, the jerk-based optimal reference trajectory is designed so that 10 $\mu \text{m}$ displacement at the constant speed with the smooth accel/deceleration period can be achieved. Having an experimental setup with several scenarios such as the constant speed of 10 $\mu \text{m}$ /s, 20 $\mu \text{m}$ /s, and 40 $\mu \text{m}$ /s, the tracking error can minimize within ± 2.5 nanometers, ± 3 nanometers, and ± 5 nanometers in the x-axis for each case. Moreover, the hysteresis variable is well compensated that the relationship between the reference trajectory and output displacement is almost linear. The proposed control strategies and implementation methods can operate the piezoelectric actuated XY stage system with the nanoscale precision motion for convenience.

Objective Previous studies investigating association of alcohol intake and fracture risk in elderly yielded conflicting results. We first examined the association between alcohol intake and total fracture risk in elderly subjects and further analyzed whether the association varied by fracture locations.Methods This is a nationwide population-based cohort study which included all people aged 66 (n=1,431,539) receiving the National Screening Program during 2009–2014. Time-to-event were defined as duration from study recruitment, the day they received health screening, to the occurrence of fracture.Results Total fracture was significantly lower in mild drinkers [adjusted hazard ratio (aHR)=0.952; 95% confidence interval (95% CI) =0.931–0.973] and higher in heavy drinkers (aHR=1.246; 95% CI=1.201–1.294) than non-drinkers. Risk pattern of alcohol consumption and fracture differed according to affected bones. Similar J-shaped trends were observed for vertebra fractures, but risk of limb fracture showed a linear relationship with alcohol intake. For hip fracture, risk decrement was more pronounced in mild and moderate drinkers, and significant increment was noted only in very severe drinkers [≥60 g/day; (aHR)=1.446; 1.162–1.801].Conclusion Light to moderate drinking generally lowered risk of fractures, but association between alcohol and fracture risk varied depending on the affected bone lesions.

Objective We aimed to explore the impact of moderate intensity exercise on the cortical thickness and subcortical volumes of preclinical Alzheimer’s disease (AD) patients.Methods Sixty-three preclinical AD patients with magnetic resonance imaging (MRI) and 18-florbetaben positron emission tomography (PET) data were enrolled in the study. Information on demographic characteristics, cognitive battery scores, self-reported exercise habits were attained. Structural magnetic resonance images were analyzed and processed using Freesurfer v6.0.Results Compared to Exercise group, Non-Exercise group demonstrated reduced cortical thickness in left parstriangularis, rostral middle frontal, entorhinal, superior frontal, lingual, superior parietal, lateral occipital, inferior parietal gyrus, temporal pole, precuneus, insula, fusiform gyrus, right precuneus, superiorparietal, lateral orbitofrontal, rostral middle frontal, medial orbitofrontal, superior frontal, lingual, middle temporal gyrus, insula, supramarginal, parahippocampal, paracentral gyrus. Volumes of right thalamus, caudate, putamen, pallidum, hippocampus, amygdala were also reduced in Non-Exercise group.Conclusion Moderate intensity exercise affects cortical and subcortical structures in preclinical AD patients. Thus, physical exercise has a potential to be an effective intervention to prevent future cognitive decline in those at high risk of AD.

Electrostatic self-potentials of individual particles trapped at an oil–water interface were determined, and the effects of surface chemical nonuniformity on heterogeneous self-potentials and equilibrium microstructures were investigated. Direct measurement of the pair interactions and the self-potentials of polystyrene microspheres were performed using optical laser tweezers. The individual particles had different self-potentials even when they possessed the same surface functionalities. Atomic force microscopy measurements elucidated the relationship between nonuniform surface charge distribution and heterogeneity and magnitude of self-potentials. Monte Carlo simulations demonstrated that self-potential heterogeneity led to the formation of more melted microstructures that showed excellent consistency with experiments.

Additional file 2. Study inclusion spreadsheet.

Additional file 3. Data extraction spreadsheet.

Additional file 1. Supplementary material-CONSORT diagram.

Additional file 1. PRISMA-P Checklist.