The Fabrication, Actuation, and Application of Magnetically Actuated Self-Assembled Artificial Cilia

"Artificial cilia", "biomimetics", "microfluidics"NI. Introduction 1 II. Development and Biomimetic Cilia Motion of Reprogrammable Magnetically Actuated Self-Assembled (RMS) Cilia Array 5 2.1 Motivation 5 2.2 Methods 7 2.2.1 Fabrication, Magnetization, and Characterization of RMS Cilia Array 7 2.2.2 Motion Measurement of RMS Cilia Array 10 2.2.3 Flow Measurement in Fluid Channel 11 2.2.4 Particle Intensity Analysis for Fluid Flow Evaluation 13 2.2.5 Simulations of RMS Cilia Array 14 2.3 Results 15 2.3.1 Fabrication of RMS Cilia Array 15 2.3.2 Fundamental Motions of RMS Cilia Array 17 2.3.3 Fluid Tests using Unilateral Cilia Array Channel 19 2.3.4 Fluid Tests using Bilateral Cilia Array Channels 21 2.4 Discussion 26 III. Heavy Metal Adsorption Using CNT Permeated Magnetically Actuated Self-Assembled Cilia (CMSC) 29 3.1 Motivation 29 3.2 Methods 32 3.2.1 Materials 32 3.2.2 Fabrication and Characterization of CMSC 32 3.2.3 Experimental Setup and Magnetic Actuation of CMSC 34 3.2.4 Heavy Metal Adsorption and Desorption Performance of CMSC 35 3.3 Results 37 3.3.1 Fabrication and Characterization of CMSC 37 3.3.2 Methylene Blue Adsorption Performance Test 38 3.3.3 Heavy Metal Ion Adsorption Performance Test 40 3.4 Discussion 41 IV. Conclusion and Future Work 43 V. Reference 45 요 약 문 53MasterdCollectio

Reprogrammable Magnetically Actuated Self‐Assembled Cilia Array

Motile cilia move in an asymmetric pattern and implement a metachronal wave (MCW) to facilitate fluid movement in a viscous environment. Studies have been conducted to mimic MCW movement of motile cilia, but the fabrication process is too complicating or there are difficulties in accurately mimicking the shape of the cilia. To overcome these limitations, a self‐assembly method is introduced to fabricate a reprogrammable magnetically actuated self‐assembled (RMS) cilia array that can be reprogrammed by changing the magnetization direction through additional magnetization. Using the RMS cilia array, a unilateral cilia array (UCA) channel and a bilateral cilia array (BCA) channel are constructed, and the motion and fluid flow of the RMS cilia array are analyzed by applying different magnetic fields (strike magnetic field and rotating magnetic field). When a rotating magnetic field is applied to the UCA channel, a distinct MCW appears. In the BCA channel test, fluid pumping is observed when a strike magnetic field is applied, whereas fluid mixing is observed when a rotating magnetic field is applied. Based on these results, it is expected that the proposed RMS cilia array and magnetic field actuation can be applied to lab‐on‐a‐chip or microfluidic channels for fluid mixing and pumping

Particulate Behavior in Subway Airspace

The most pivotal approach to improve subway indoor air quality (IAQ) is to examine the emission sources and particulate behavior. Therefore, the main objective of this study is to investigate the particulate behavior in the subway. In order to examine IAQ in the subway, a sampling and measurement campaign was carried out for 35 sites during the summer and winter seasons from May, 2005 to February, 2006. In case of 24 hour measurement, the mean concentrations (PM10-24 hr) of platform and waiting room were 156.18±53.79 μg/m3 and 111.00±53.31 μg/m3. Besides, as a result of 20 hour measurement, the mean concentrations (PM10-20 hr) of platform and waiting room were 146.09±53.71 μg/m3 and 99.08±42.77 μg/m3, respectively. In general, PM10-24 hr was higher than PM10-20 hr, and both PM concentrations showed a high correlation coefficient (r=0.803). It was found that the PM2.5 concentration (109.56±28.24 μg/m3) in winter was higher than that (83.66±57.82 μg/m3) in summer

Magnetically Steerable Asymmetric Magnetized Soft Continuum Robot (AMSCR) for Minimally Invasive Surgery

Soft continuum robots have been widely used as guide wires or catheters for minimally invasive surgery (MIS), and the miniaturization and dexterity are very important characteristics of soft continuum robots. As a representative actuation method for soft continuum robots, the steering using an external magnetic field has been actively studied. The magnetic actuation method is appropriate for the miniaturization of soft continuum robots but shows limitations in implementing high dexterity. To achieve miniaturization and high dexterity, this paper proposes a magnetically steerable asymmetric magnetized soft continuum robot (AMSCR). The proposed AMSCR includes an active steering part (ASP) of a thin PDMS cylinder in which NdFeB powder is uniformly dispersed and magnetized asymmetrically to the longitudinal direction. Therefore, compared to the conventional symmetric magnetized soft continuum robot (SMSCR), the proposed AMSCR has a larger steering range and high dexterity. Through various experiments, simulations, and phantom experiments using the proposed AMSCR, we analyzed its characteristics, verified its enhanced steering range, and demonstrated the applicability to the surgeries requiring high dexterity in the eye or cerebrovascular. © 2022 IEEE

Persistent Drug-Induced Parkinsonism in Patients with Normal Dopamine Transporter Imaging.

Functional neuroimaging for the dopamine transporter (DAT) is used to distinguish drug-induced parkinsonism (DIP) from subclinical Parkinson's disease (PD). Although DIP patients who show a normal DAT image are expected to recover completely, some do not. We investigated whether these patients showed changes in striatal DAT activity using semi-quantitative analysis of 18F-FP-CIT PET data. DIP patients with visually normal DAT images were selected from medical records. The subjects were classified as patients who recovered partially (PR) or completely within 12 months (CR). The 18F-FP-CIT uptake in each striatal subregion was compared between the CR and the PR groups. In total, 41 and 9 patients of the CR and PR groups were assessed, respectively. The two patient groups were comparable in terms of clinical characteristics including age, sex, and severity of parkinsonism. From semi-quantitative analysis of the PET image, the PR patients showed a relatively lower ligand uptake in the ventral striatum, the anterior putamen and the posterior putamen compared with the CR patients. This result suggests that persistent DIP in patients with visually normal DAT imaging may be associated with subtle decrement of DAT activity

Apathy and Olfactory Dysfunction in Early Parkinson’s Disease

Objective Olfactory and emotional dysfunctions are very common in patients with Parkinson’s disease (PD). Olfaction and emotions share common neuroanatomical substrates. Therefore, in this study, we evaluated the association between olfactory and emotional dysfunctions in patients with PD. Methods Parkinson’s disease patients who had been assessed for their olfactory function and neuropsychiatric symptoms including emotional dysfunction were included. A logistic regression analysis was performed to evaluate the association between low olfaction and different neuropsychiatric symptoms. Results The patients with low olfaction (cross cultural smell identification test score ≤ 6) showed a higher prevalence of apathy when compared with those with high olfaction, whereas the frequencies of other neuropsychiatric symptoms were comparable between the two groups. A multivariate logistic regression analysis revealed that the presence of apathy/indifference [odds ratio (OR) = 2.859, p = 0.007], age 70 years or more (OR = 2.281, p = 0.009), and the male gender (OR = 1.916, p = 0.030) were significantly associated with low olfaction. Conclusions Our results demonstrate that apathy/indifference is a unique emotional dysfunction associated with olfactory dysfunction in PD. The findings also suggest that PD patients with low olfaction have a high prevalence of apathy