• Restorative Dentistry and Endodontics
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• v.45 no.3
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• pp.36.1-36.10
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• 2020

Objectives: This study aims to assess the effect of universal adhesives pretreatment on the bond strength of resin-modified glass ionomer cement to dentin. Materials and Methods: Fifty caries-free human third molars were employed. The teeth were randomly assigned into five groups (n = 10) based on dentin surface pretreatments: Single Bond Universal (3M Oral Care), Gluma Bond Universal (Heraeus Kulzer), Prime&Bond Elect (Dentsply), Cavity Conditioner (GC) and control (no surface treatment). After Fuji II LC (GC) was bonded to the dentin surfaces, the specimens were stored for 7 days at 37℃. The specimens were segmented into microspecimens, and the microspecimens were subjugated to microtensile bond strength testing (1.0 mm/min). The modes of failure analyzed using a stereomicroscope and scanning electron microscopy. Data were statistically analyzed with one-way analysis of variance and Duncan tests (p = 0.05). Results: The surface pretreatments with the universal adhesives and conditioner increased the bond strength of Fuji II LC to dentin (p < 0.05). Single Bond Universal and Gluma Bond Universal provided higher bond strength to Fuji II LC than Cavity Conditioner (p < 0.05). The bond strengths obtained from Prime&Bond Elect and Cavity Conditioner were not statistically different (p > 0.05). Conclusions: The universal adhesives and polyacrylic acid conditioner could increase the bond strength of resin-modified glass ionomer cement (RMGIC) to dentin. The use of universal adhesives before the application of RMGIC may be more beneficial in improving bond strength.

• Korean Journal of Exercise Nutrition
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• v.23 no.3
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• pp.50-55
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• 2019

[Purpose] The purpose of this study was to identify the relationships between muscle mass, muscle strength, and physical and cognitive functions and to examine the effects of resistive Theraband® exercise on sarcopenia-associated variables in the older population. [Methods] A total of 28 elderly women (age: 69.90 ± 0.8 years) participated in this study, 15 of whom underwent elastic band exercise for 1 hour per day, twice per week for 8 weeks. The correlation analysis was conducted to identify the associations between body composition, skeletal muscle mass indices, grip strength, and physical and cognitive functions. All variables were assessed at baseline and post-exercise. [Results] Skeletal muscle mass was significantly associated with grip strength and physical function. Gait speed was positively correlated with grip strength and physical function, but not with cognitive function. Theraband® exercise significantly improved gait speed and physical function. [Conclusion] The present data suggest that skeletal muscle mass is highly correlated with grip strength and physical function. Eight weeks of resistive Theraband® exercise favorably affects sarcopenia by improving gait speed and mobility of elderly women.

• Journal of Sasang Constitutional Medicine
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• v.15 no.3
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• pp.62-73
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• 2003

Lee, Jema recognized human being as human figure and human nature according to 'if threre is a thing, there are a law to explain the thing'. And he thought Sa-Sang is the most basic and proper concept to explain things and changes. This paper is to find his medical view why human beings are classified into four types. 1. A medical clue to classify human being is different viscera function. 2. The size of viscera means the strength and weakness of metabolic function of viscera. 3. The essence of different viscera function is related to metabolism of water and food, air and fluid. Lungs and Liver do metabolic function through exhale and inhale of air and fluid. Spleen and Kidneys do metabolic function through intake an d output water and food. 4. It is most important to consider and to treat the condition of small size viscera.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.11a
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• pp.188-189
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• 2013

The purpose of this research is to comprehend experimentally the characteristic of human dynamic load and provide the result as basic data to suggest a valid impact-resistance evaluation method. Human motions exerting dynamic load are classified to 3 types. Selecting 3 ranks of motion strength, 3 ranks of load plane stiffness (A:20kN/cm, B:4.7kN/cm, C:2.2kN/cm), and 30 male grownup inspectors in their twenties, load was measured when they applied force on load plane. Result of this research is as follows: (1) Human dynamic load has different nature from object collision in the highest load ratio depending on the load plane stiffness and action time (2) The highest load ratio for each motion was 10.06 for kicking, 4.44 for hitting with shoulder, and 5.58 for fist blow.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.505-508
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• 2006

Self-leveling mortar is walkable bottom mortar which can maintain the horizontality of self fluid and have the the quick-setting quality, the low-human-effort practicable material of high-quality bottom in construction. In accordance with more adhesive strength with bottom side and absorption control, Primer is used for purpose to prevent pin-hole occurrence by self leveling mortar application prior to construction. This study is composed measurement of absorption, adhesive strength. Used material is NP-40 as nonionic emulsifying agent, uses SA-210L as negative ion emulsifying agent, uses APS, SBS as ridical initiator. A result of test, in accordance with image of Primer, as low temperature and application frequency, indicates low absorption rate and adhesive strength, as solid powder and dryness time is increse, absorption rate and adhesive strength lowly shows figure.

• The korean journal of orthodontics
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• v.21 no.3
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• pp.513-520
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• 1991

The purpose of this study was to compare the bracket placement and the shear bond strength of indirect-bonded brackets with those of direct-bonded ones. Forty eight extracted human teeth were collected and attached with brackets and tested on shear bond strength, using Instron. Fourteen patients from Wonkwang University Dental Hospital were selected for direct bonding of brackets and their teeth were measured on bracket angulation and bracket height. The obtained results were as follows: 1. The shear bond strengths of incisors were higher in direct-bonding,group, rather than in-direct-bonding group. But, the shear bond strength of premolars showed no significant differences between groups. 2. The bracket angulations of indirect-bonding group were preciser than those of direct-bonding group, especially in upper first premolars, lower lateral incisors, canines, premolars. 3. In bracket height, there were no significant differences between groups.

• Composites Research
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• v.30 no.3
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• pp.169-174
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• 2017

Demand of glass fiber reinforced composites (GFRC) increased with developing aircraft and defense industries using resin transfer molding (RTM) process to produce complex product. In this research, wetting, interfacial, and mechanical properties were evaluated with different Cross-linking Density by Molecular Weight of Hardener. Epoxy resin as matrices was used bisphenol-A type and amine-type hardeners with different molecular weight. Specimens were manufactured via RTM and wetting property of resin and glass fiber (GF) mat was evaluated to viscosity of epoxy and injection time of epoxy matrix. Mechanical property of GFRC was determined via flexural strength whereas interfacial properties were determined by interlaminar shear strength (ILSS) and interfacial shear strength (IFSS). The difference in mechanical property depends upon the fiber weight fraction (wt %) of GFRC by RTM as well as the different Molecular Weight of Hardener.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.510-513
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• 2006

Purpose: The Rectus abdominis muscle free flap is utilized in various reconstruction surgeries due to easiness in harvesting, consistency of vascular pedicle and reduced donor site morbidity. But rarely, femoral nerve injury during rectus abdominis harvesting can be resulted. We report a case of femoral nerve injury after rectus muscle harvesting and discuss the injury mechanism with the follow-up process of this injury. Methods: To reconstruct the defect of middle cranial base after wide excision of cystic adenocarcinoma of the external ear, rectus muscle free flap was havested in usual manner. To achieve a long vessel, inferior epigastric artery was dissected to the dividing portion of femoral artery and cut. Results: One week after the surgery, the patient noted sensory decrease in the lower leg, weakness in muscle strength, and disabilities in extension of the knee joint resulting in immobilization. EMG and NCV results showed no response on stimulation of the femoral nerve of the left leg, due to the defects in femoral nerve superior to the inguinal ligament. With routine neurologic evaluations and physical therapy, on the 75th day after the operation, the patient showed improvement in pain, sensation and muscle strength, and was able to move with walking frame. In 6 months after the operation, recovery of the muscle strength of the knee joint was observed with normal flexion and extension movements. Conclusion: Rarely, during dissection of the inferior epigastric artery, injuries to the femoral nerve can be resulted, probably due to excessive traction or pressure from the blade of the traction device. Therefore, femoral nerve injury can be prevented by avoiding excessive traction during surgery.

• Archives of Plastic Surgery
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• v.35 no.1
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• pp.7-12
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• 2008

Purpose: Since the report of artificial dermis manufacturing method using collagen by Yannas in 1980, collagen has been effectively used as dermal substitute with its merits such as, lower antigeneicity, controllable biodegradation rate, and minimal inflammatory cytotoxic properties in the dermal tissue engineering field. However, weak mechanical durability was the main drawback of collagen dermal substitute. To improve its stability, mechanical or chemical cross-linking was used. Despite of such process, its clinical use was restricted due to weak durability. To improve the durability of collagen matrix, we designed elastin-incorporated collagen matrix and compared its durability with conventional collagen matrix. Methods: 15mm diameter with 4mm thick collagen dermal matrix was made according to Yannas protocol by mixing 0.5% bovine collagen and chondroitin-6-sulfate followed by degassing, freeze drying, dehydrodermal cross-linking and chemical cross-linking procedure. In elastin incorporated collagen matrix, same procedure was performed by mixing elastin to previous collagen matrix in 4:1 ratio(collagen 80% elastin 20%). In comparison of the two dermal matrix in vitro tests, matrix contracture rate, strain, tensile strength, was measured and stiffness was calculated from comparative analysis. Results: In terms of matrix contracture, the elastin-incorperated added collagen dermis matrix showed 1.2 times more contraction compared to conventional collagen matrix. However, tensile strength showed 1.6 times and stiffness showed 1.6 times increase in elastin-incorporated matrix. Conclusion: Elastin incorperated collagen matrix manufactured by our team showed increased durability due to improvement in tensile strength and stiffness compared to previous collagen matrix($Integra^{(R)}$).

• Journal of Biomedical Engineering Research
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• v.15 no.3
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• pp.341-346
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• 1994

To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atel- ocollagen was produced. The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength.