• Journal of Korean Neurosurgical Society
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• 제49권2호
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• pp.83-91
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• 2011

Objective : Minocycline, a second-generation tetracycline-class antibiotic, has been well established to exert a neuroprotective effect in animal models and neurodegenerative disease through the inhibition of microglia. Here, we investigated the effects of minocycline on motor recovery and neuropathic pain in a rat model of spinal cord injury. Methods : To simulate spinal cord injury, the rats' spinal cords were hemisected at the 10th thoracic level (T10). Minocycline was injected intraperitoneally, and was administered 30 minutes prior surgery and every second postoperative day until sacrifice 28 days after surgery. Motor recovery was assessed via the Basso-Beattie-Bresnahan test Mechanical hyperalgesia was measured throughout the 28-day post -operative course via the von Frey test Microglial and astrocyte activation was assessed by immunohistochemical staining for ionized calcium binding adaptor molecule 1 (lba1) and glial fibrillary acidic protein (GFAP) at two sites: at the level of hemisection and at the 5th lumbar level (L5). Results : In rats, spinal cord hemisection reduced locomotor function and induced a mechanical hyperalgesia of the ipsilateral hind limb. The expression of lba1 and GFAP was also increased in the dorsal and ventral horns of the spinal cord at the site of hemisection and at the L5 level. Intraperitoneal injection of minocycline facilitated overall motor recovery and attenuated mechanical hyperalgesia. The expression of lba1 and GFAP in the spinal cord was also reduced in rats treated with minocycline. Conclusion : By inhibiting microglia and astrocyte activation, minocycline may facilitate motor recovery and attenuate mechanical hyperalgesia in individuals with spinal cord injuries.

• Journal of Rhinology
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• 제59권1호
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• pp.49-58
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• 2021

Background: Nasal polyps in the nasal cavity and mucous discharge inside the maxillary sinus exhibit compressive stress on the nasal mucosal epithelium. However, there have been only a few studies on how compressive stress impacts the human nasal mucosal epithelium. Methodology: We investigated the effect of compressive stress on collective migration, junctional proteins, transepithelial electrical resistance, epithelial permeability, and gene expression in well-differentiated normal human nasal epithelial (NHNE) cells and human nasal polyp epithelial (HNPE) cells. Results: NHNE cells barely showed collective migration at compressive stress up to 150 mmH₂0. However, HNPE cells showed much greater degree of collective migration at a lower compressive stress of 100 mmH₂0. The cell migration of HNPE cells subjected to 100 mmH₂O compression was significantly decreased at day 3 and was recovered to the status prior to the compressive stress by day 7, indicating that HNPE cells are relatively more sensitive to mechanical pressure than NHNE cells. Compressive stress also increased transepithelial electrical resistance and decreased epithelial permeability, indicating that the compressive stress disturbed the structural organization rather than physical interactions between cells. In addition, we found that compressive stress induced gene expressions relevant to airway inflammation and tissue remodelling in HNPE cells. Conclusion: Taken together, these findings demonstrate that compressive stress on nasal polyp epithelium is capable of inducing collective migration and induce increased expression of genes related to airway inflammation, innate immunity, and polyp remodelling, even in the absence of inflammatory mediators.

• Wind and Structures
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• 제25권5호
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• pp.459-474
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• 2017

In this study an analytical expression is derived for the natural frequency of the wind turbine towers supported on flexible foundation. The derivation is based on a Euler-Bernoulli beam model where the foundation is represented by a stiffness matrix. Previously the natural frequency of such a model is obtained from numerical or empirical method. The new expression is based on pure physical parameters and thus can be used for a quick assessment of the natural frequencies of both the real turbines and the small-scale models. Furthermore, a relationship between the diagonal and non-diagonal element in the stiffness matrix is introduced, so that the foundation stiffness can be obtained from either the p-y analysis or the loading test. The results of the proposed expression are compared with the measured frequencies of six real or model turbines reported in the literature. The comparison shows that the proposed analytical expression predicts the natural frequency with reasonable accuracy. For two of the model turbines, some errors were observed which might be attributed to the difference between the dynamic and static modulus of saturated soils. The proposed analytical solution is quite simple to use, and it is shown to be more reasonable than the analytical and the empirical formulas available in the literature.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1760-1763
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• 2002

In this paper the authors present their attempt io realize a motion pattern detector that finds specified sequence of image from input motion image. The detector is intended to be used for time-varying facial expression understanding. Needless to say, facial expression understanding by machine is crucial and enriches quality of human machine interaction. Among various facial expressions, like blinking, there must be such expressions that can not be recognized if input expression image is static. Still image of blinking can not be distinguished from sleeping. In this paper, the authors discuss implementation of their motion pattern detector and describe experiments using the detector. Experimental results confirm the feasibility of the idea behind the implemented detector.

• 식물조직배양학회지
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• 제25권2호
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• pp.89-93
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• 1998

Tomato phenylalanine ammonia-lyase 5 (tPAL5) was identified that alternate initiation sites were utilized differentially in response to environmental stimuli (Lee et al, 1992b). In this study, we tried to look into tissue -or cell- specific expression pattern of tPAL5 gene by fusing with ${\beta}-glucuronidase$ (GUS) gene in transgenic tobacco plants. In transgenic plants, root and stem extracts contained 8~12 fold higher levels of GUS activity than petiole or leaf tissue while the highest levels of induction was observed from leaf tissue by mechanical wounding (5~11 fold). In trans-sections of stems and petioles, GUS activity was restricted to phloem cells(outer region) of developing vascular bundle and mainly at apical tip region in the root tissues. The levels of GUS activity was drastically reduced (10~12 fold reduction) when the 5'-upstream region of tPAL5 gene (-1151bp from ATG codon) was deleted up to -665. The levels of GUS expression, however, raised up by 6~8 fold when deleted up to -455. Therefore, we conclude that there are positive cis-elements at the region -1151 to -1008 and at -455 to -195 while the negative cis-element is at -1008 to -455.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제34권3호
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• pp.250-265
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• 2008

Distraction osteogenesis is a well-established clinical treatment for limb length discrepancy and skeletal deformities. Appropriate mechanical tension-stress is believed not to break the callus but rather to stimulate osteogenesis. In contrast to fracture healing, the mode of bone formation in distraction osteogenesis is primarily intramembranous ossification. Although the biomechanical, histological, and ultrastructural changes associated with distraction osteogenesis have been widely described, the basic biology of the process is still not well known. Moreover, the molecular mechanisms in distraction osteogenesis remain largely unclear. Recent studies have implicated the growth factor cascade is likely to play an important role in distraction. And current reserch suggested that mechanical tension-stress modulates cell shape and phenotype, and stimulates the expression of the mRNA for bone matrix proteins. The purpose of this study is to examine the pattern of expression of growth factors($TGF-{\beta}1$, IGF-I, bFGF) and extracellular matrix proteins(osteoclacin, osteonectin) related to osteogenesis by osteodistraction of the mandible in rabbits. 24 rabbits is used for this experiment. Experimental group are gradual distraction(0.7mm, twice/day), acute distraction(1.4mm, twice/day) and control group is only osteotomized. After 5 days latency, osteotomic site is distracted for each 7 days and 3.5 days. Consolidation period is 28 days. The animal is sacrificed at the 3th, 7th, 14th, 28th. The distracted bone is examined by immunohistochemical analysis and RT-PCR analysis. The results obtained from this study were as follow : No significant difference was found on clinical examination according to distraction rate, but gradual distraction was shown to improve regenerate bone formation on radiographic and histologic examination. Growth factors and extracelluar matrix proteins expression increased in distraction group than control group. From these results, it could be stated that graudal distraction is shown to improve and accelerate bone formation and mechanical stress like distraction has considerable effects on osteogenesis related factors. And rabbit is the most appropriate animal model for further reseach on the molecular mechanisms that mediate osteodistraction. It is believed that understanding the biomolecular mechanisms that mediate distraction osteogenesis may guide the development of targeted strategies designed to improve distraction osteogenesis and accelerate bone healing.

• Journal of Acupuncture Research
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• 제21권1호
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• pp.240-251
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• 2004

Objective: We have studied to know effects of acupuncture at SI3, BL40, SI3 BL40 on mechnical allodynia, cold allodynia and c-fos protein expression in a model of neuropathic pain of rat. Methods: A model of neuropathic pain was made by injuring tibial nerve and sural nerve while common peroneal nerve was maintained. after 2 weeks, we performed behavioral tests for 7 days to try out mechnical allodynia using von frey filament and cold allodynia using acetone, which are calculated by counting withdrawal response on foot. Rat brains removed and sliced on 8th days. Serial sections were immunohistochemically reacted with polyclonal c-fos antibody. The numbers of c-Fos protein immunoreactive neurons in the central gray were examined using scion image program. Results: Mechanical allodynia in the SI3, BL40, SI3 BL40 groups were diminished compared with the control group. Cold allodynia in the SI3, BL40, SI3 BL40 groups were diminished compared with the control group. c-Fos protein expression on the central gray in the SI3 group were lower than that of the control group. Conclusions: We have noticed that acupuncture at SI3, BL40, SI3 BL40 diminished mechanical allodynia and cold allodynia in a model of neuropathic pain compared with the control group. c- Fos protein expression in the central gray of that group was also decreased compared with the control group. pain control using acupunture was accumulated as time goes by. This study can be used as a basic resource on a study and a treatment of pain.

• 한국기계가공학회지
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• 제13권2호
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• pp.1-7
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• 2014

Recent experimental observations support the hypothesis that mechanical stimuli play a role in regulating the specialized molecular expression of articular cartilage in vitro and in vivo. Other studies have demonstrated that the continuous passive motion(CPM)bioreactor for whole joints can provide a platform for possible future in vitro studies and applications, including possible interactions of bio-mechanical and biochemical signals. In this study, we have developed acustom-made bioreactor capable of bending and stretching with circular type motion, and a biomimetic knee joint model, using a 3D printer. This system could be used to investigate the effects of rehabilitative joint motion of dynamic culture.

• 펄프종이기술
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• 제40권2호
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• pp.65-72
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• 2008

This work evaluated the extractability of tobacco stem biomass for the papermaking type Reconstituted Tobacco Sheet(RTS). The effects of the soaking conditions on the hydration of stem biomass and the effects of the hydrated state on the mechanical extraction were investigated. In order to simulate the mechanical expression process of a papermaking type RTS mill, for example, the screw press process, the novel mechanical pressing analyzer was developed for this study. The hydration of stem biomass by soaking process was greatly affected by the soaking time and the soaking temperature. The longer soaking time and the higher soaking temperature resulted in the higher hydrated stem biomass. Since the higher hydrated stem had more combined water in the inner structure and resulted in the more flexible structure, the higher hydrated stem leaded to the more compressed filter cake and the higher water contents in the filter cake after the mechanical pressing. The pilot pulping experiments showed the difference in hydration and extractability between burley and bright tobacco stem. The bulkier structure of the burley stem resulted in the faster hydration by pilot pulping and leaded to the larger reduction in water soluble components. And the hydration process showed the major influence on the separation efficiency of water soluble components.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1585-1587
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• 2008

Fibroblast is constantly subjected to mechanical loads in connective tissues where mechanical signals are converted to intercellular biochemical events. The aim of this study is to understand the effects of tensile stress on the neurotrophin (NT) and transforming growth factor (TGF) expression of fibroblast in vitro. Nerve growth factor (NGF) stimulates fibroblast migration, and TGF is related to tissue repair. In this study, at the uniaxial stretch of 10% strain and frequency of 0.5 Hz, different resting times of 0, 20, and 60 min are placed in between 10 min stimulations periods. Results show increase in NGF mRNA levels and a substantial decrease in NT3 mRNA after 1 hr of stimulation, indicating that the tensile stress may regulate NGF and NT3, key factors for the neurocosmetic applications. The mRNA level for TGF-${\alpha}$ and TGF-${\beta}2$ had increased up to two-folds after 1 hr of stimulation, showing that the tensile stress may control TGF, an important part of wound healing.