• Journal of Biosystems Engineering
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• v.39 no.3
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• pp.244-252
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• 2014

Purpose: The development of an efficient in vitro cell culture device to process various cells would represent a major milestone in biological science and engineering. However, the current conventional macro-scale in vitro cell culture platforms are limited in their capacity for detailed analysis and determination of cellular behavior in complex environments. This paper describes a microfluidic-based culture device that allows accurate control of parameters of physical cues such as pressure. Methods: A microfluidic device, as a model microbioreactor, was designed and fabricated to culture Saccharomyces cerevisiae and Chlamydomonas reinhardtii under various conditions of physical pressure stimulus. This device was compatible with live-cell imaging and allowed quantitative analysis of physical cue-induced behavior in yeast and microalgae. Results: A simple microfluidic-based in vitro cell culture device containing a cell culture channel and an air channel was developed to investigate physical pressure stress-induced behavior in yeasts and microalgae. The shapes of Saccharomyces cerevisiae and Chlamydomonas reinhardtii could be controlled under compressive stress. The lipid production by Chlamydomonas reinhardtii was significantly enhanced by compressive stress in the microfluidic device when compared to cells cultured without compressive stress. Conclusions: This microfluidic-based in vitro cell culture device can be used as a tool for quantitative analysis of cellular behavior under complex physical and chemical conditions.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.605-612
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• 2016

Membrane bioreactors (MBRs) employ a process of biological treatment that is based on a membrane that has the advantages of producing high-quality treated water and possessing a compact footprint. However, despite these advantages, the occurrence of "fouling" during the operation of these reactors causes the difficulty of maintenance. Hence, in this study, three physical cleaning methods, namely, backwashing, air scrubbing, and mechanical cleaning ball was performed to identify optimum operating conditions through laboratory scale experiments, and apply them in a pilot plant. Further, the existing MBR process was compared with these methods, and the field applicability of a combination of these physical cleaning methods was investigated. Consequently, MCB, direct control of cake fouling on the membrane surface was found to be the most effective. Moreover, as a result of operating with combination of the physical cleaning process in a pilot plant, the TMP increasing rate was found to be - 0.00007 MPa/day, which was 185% higher than that obtained using the existing MBR process. Therefore, assuming fouling only by cake filtration, about one year of operation without chemical cleaning is considered to be feasible through the optimization of the physical cleaning methods.

• Physical Therapy Korea
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• v.28 no.3
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• pp.200-207
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• 2021

Background: Postural control deficit is a major characteristic in patients with chronic ankle instability (CAI). Elastic ankle tapings are commonly used to facilitate postural control in patients with CAI as well as prevent relapse of a lateral ankle sprain. However, equivocal evidence exists concerning the effect of elastic ankle taping on postural control. Objects: This study aimed to evaluate the effects of elastic ankle tapings using kinesio taping (KT) and dynamic taping (DT) on static and dynamic postural control in patients with CAI. Methods: Fifteen subjects with CAI were participated in this study. The participants performed tests under three conditions (barefoot, KT, and DT). Static postural control was evaluated using the one-leg standing test (OLST) and dynamic postural control using the modified Star Excursion Balance Test (mSEBT). One-way repeated-measures analysis of variance was used to compare center of pressure (CoP) data and normalized mSEBT reach distances among the three conditions (with α = 0.05). Results: The CoP parameters (path length, ellipse area, and mean velocity) of the OLST significantly decreased on applying KT and DT compared with those when barefoot. The normalized reach distances in the anteromedial (AM), medial (M), and posteromedial (PM) directions of the mSEBT significantly increased with DT compared to that in the control condition. Further, the higher reach distances with KT compared with those in the control condition were obtained in the M and PM directions of the mSEBT. No significant differences were identified in any of the OLST and SEBT parameters between the two different taping applications. Conclusion: KT and DT improved static postural control during the OLST compared with the control condition. Moreover, these tapes improved dynamic postural control during the mSEBT compared to the control. Therefore, elastic ankle tapings are useful prophylactic devices for the prevention and treatment of ankle sprain in people with CAI.

• Physical Therapy Korea
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• v.29 no.2
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• pp.124-130
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• 2022

Background: During postural control, older adults are more dependent on proprioception than are young adults. Ankle proprioception, which plays an important role in maintaining postural balance, decreases with age. Published studies are insufficient to establish a significant age difference in postural sway resulting from the known age-related decrease in ankle proprioception and do not examine various detailed test conditions. Objects: The present study aimed to compare ankle proprioception between older and younger groups along dimensions of position vs. force proprioception and dorsiflexion vs. plantarflexion. The present study also aimed to compare postural sway between young and older women during quiet standing under two sensory conditions. Methods: We recruited seven young women aged 21-24 and seven older women aged 60-63. Ankle proprioception was assessed as the accuracy of the joint position sense (JPS) and the force sense (FS). Postural sway was assessed using center-of-pressure measurements recorded during quiet standing under two sensory positions: eyes open and eyes closed with head tilted back. Results: Older women had lower JPS in dorsiflexion and lower FS in plantarflexion than did younger women. We found no significant age differences in JPS in plantarflexion or in FS in dorsiflexion. We observed a main effect of group on postural sway in two sway parameters out of three. We observed significant differences in JPS with dorsiflexion, and in FS with plantarflexion. Conclusion: Proprioception for ankle plantar flexor decreased more significantly with aging than did that for ankle dorsiflexor, accounting for the impaired postural balance observed in older women.

• Journal of Korean Physical Therapy Science
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• v.25 no.2
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• pp.62-72
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• 2018

Background: The purpose of this study was to investigate a study about undergraduate students' participation in general sports. Method: A questionnaire survey was conducted on 200 students attending physical therapy at Gimcheon university students. four items of general characteristics, 2 conditions of sports for all, 2 activities of current sports for all, and 1 thing of sports for all, were extracted from the questionnaires of total 40 items. Result: In the present study, it was found that through the cross-sectional analysis of various variables related to life sports activities according to grade, sex, age and living cost level, students participated in less sports activities than other college students. And they participated in non-living sports activities such as appreciation and movie appreciation. In addition, it was found that factors such as watching sports games mainly affect the lives of women, especially with less sports activities, and men are more active at 20 to 28 years of age than those aged 20. Conclusion: These findings suggest that it is necessary to provide various opportunities to encourage the physical activities of female students and young students of the university and actively participate in sports for all.

• Physical Therapy Korea
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• v.13 no.3
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• pp.102-110
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• 2006

To improve trunk stability, various exercise protocols were introduced into the clinical field. Trunk and lumbar stability exercises on unstable surfaces are especially recommended to improve lumbar stability. The purpose of this study was to compare abdominal oblique muscle activity during leg raising in hook-lying position among 3 different type of surface conditions (on floor (F), vestibular board (VB), and foam roll (FR)). Sixteen able-bodied volunteers, who had no medical history of lower extremity or lumbar spine disease, were recruited for this study. Surface electromyography (EMG) activity was recorded from the internal and external oblique muscles of both sides. The normalized EMG activity was compared using a one-way repeated ANOVA. The results showed that the EMG activities of the internal oblique and external oblique of the lifted leg side during straight leg raising significantly increased under the FR condition when compared to the F condition. There was no significant difference of the EMG activity in abdominal oblique muscles between the VB and the FR conditions. The EMG activity of the internal oblique of supported leg side during the straight leg raising was significantly greater under the FR condition than the VB and F conditions (p<.05). The composition ratio of EMG activity of internal oblique muscles during straight leg raising was significantly increased under the FR condition. Therefore, straight leg raising exercise on foam roll in hook lying position could be beneficial to improve trunk and lumbar stability.

• Journal of Korean Physical Therapy Science
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• v.18 no.2
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• pp.29-40
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• 2011

Purpose: The purpose of this study was to analyze the changes of parameters of foot contact by various carrying a pack methods during walking. Method: The subjects were consisted of normal forty four persons (males 30, females 14, mean age 23). The carrying a pack methods were classified into five conditions: carrying no bag(Con 1), carrying a backpack(Con 2), carrying a shoulder bag(Con 3), carrying a cross bag(Con 4), carrying a one-hand bag(Con 5). All subjects were participated in these five condition and measured foot pressure by F-scan system during walking. Then foot contact time, foot contact area, foot contact length and width were measured and analyzed. The repeated one-way analysis of variance (ANOVA) was used to get difference between conditions and independent t-test was used to get difference between left and right foot within condition. Result: In the comparison of parameters of foot, contact time, contact area and mid foot width were significantly different between conditions(p<.05), and in both foot contact time at condition 5 showed the most significant reduction(p<.05). In the comparison of parameters of foot between left and right foot within condition, every conditions were not significantly different(p>.05). Conclusion: In this study various carrying methods changed the parameters of foot contact and showed significant difference in some articles between carrying methods. However, asymmetric load of pack by carrying methods didn't affected symmetry of parameters of foot contact between left and right foot.

• Korean Institute of Interior Design Journal
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• v.19 no.4
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• pp.99-108
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• 2010

The goal of This study is to predict medical fee by accidents at home and the factors of accidents, and also to suggest the conditions of housing adaptations for elderly people. As the result of in-house accidents, on average 2.97 million Korean won was to be spent for medical care. Furthermore, 2808 billion Korean Won, which was predicted by multiplying the number of older people with the reported accident rates of 2.0% by the National Health and Nutrition Survey 2005, can be estimated to pay on medical care in 2005. And in addition it is analyzed on residential conditions and 65 cases of elderly housing. According to the 65 safety problem cases, it examines that in-house accidents of older people generally happen at the steps, toilet and bathroom. It is necessary to adapt physical conditions and it is more effective. As the result of research, medical fee by accident at home has been increasing and also it could be predicted to spend 280,800million won in 2005. To reduce medical fee, it is necessary to promote physical environment by renovation. When be decided to renovate a housing, we know that it is more effective to use a checklist of space using at home. And also it is suggested to amend a checklist with other factors including physical conditions and health condition and so on to promote a correctness.

• Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.103-112
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• 2007

High prices, overfishing, and contamination have limited the availability of natural caviar as a food product. We attempted to apply encapsulation by calcium-alginate gel membranes to caviar analog preparation in an effort to produce a high-quality replacement for natural caviar. Physical conditions of stirring speed $(X_1,\;rpm)$ and gelation time $(X_2,\;min)$ as the independent variables for gelation were optimized by response surface methodology. Sphericity $(Y_1,\;%)$, diameter $(Y_2,\;mm)$, membrane thickness $(Y_3,\;mm)$, rupture strength $(Y_4,\;g)$, and rupturing deformation $(Y_5,\;mm)$ were used as the dependent variables to compare characteristics of the capsules for caviar analogs with natural caviar. The values of the independent variables as evaluated by multiple response optimization were $X_1=-0.1271 (278 rpm) and $X_2=0.4436$ (12.2 min), respectively. Predicted values of the four dependent variables were $Y_1=97.7%,\;Y_2=2.97mm,\;Y_4=1,465g,\;and\;Y_5=1.15mm$. Membrane thickness $(Y_3)$ was eliminated from the dependent variables for multiple response optimization because it could not be measured with an image analyzer. The experimental values prepared under the optimal conditions for verification nearly coincided with the predicted values and satisfied the conditions of natural caviar.

• PNF and Movement
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• v.17 no.1
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• pp.129-136
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• 2019

Purpose: This study is a comparison of spatiotemporal parameters between straight and curved walking in individuals with chronic hemiparetic stroke, investigating whether those patients can adapt their walking according to task demands and environmental changes. Methods: Twenty-eight patients who diagnosed with their first stroke at least six months prior to this study were recruited. They were measured for spatiotemporal parameters in three different walking conditions: straight walking, walking with an inner curve to the more-affected leg, and walking with an inner curve to the less-affected leg. This study also measured secondary clinical factors, such as the timed up-and-go test, the trunk impairment scale, and the dynamic gait index. The statistical methods for the three different walking conditions, using the averaged value of each condition, was repeated measures ANOVA. Results: The difference in cadence was statistically significant when comparing straight walking, walking with an inner curve to the more-affected leg, and walking with an inner curve to the less-affected leg. Swing duration (%) was also a statistically significant difference between straight walking and walking with an inner curve to the more-affected leg. However, differences in other spatiotemporal parameters were not statistically significant among the three conditions. Conclusion: The results of this study suggest that stroke survivors could adapt their walking according to straight and curved walking conditions, although cadence and swing duration were different between straight and curved walking groups.