• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.932-938
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• 2001

This study is concerned with the shape optimization of stem for the artificial hip prosthesis with unbonded cement mantle. The artificial hip prosthesis with unbonded cement mantle allows a stem to slip on cement mantle because of polished stem surface. Unbonded cement mantle type has several advantages compared with bonded cement mantle type, for example, small micro motion, preventing stress shielding and so on. In this study, 2-dimensional axisymmetric model was developed with considering characteristics of unbonded cement mantle. Moreover, optimal shape of stem was obtained by using feasible direction method. The objective of this optimization is maximizing supported vertical loading. The slip motion and stresses of stem, cement mantle and bone is used for constraints. The optimal shape which obtained by this study has slope of 0.15 in proximal part and maintains the width about 5mm in distal part In addition, simplified 3-dimensional analysis which applying optimal shape is carried out. The result of 3-dimensional analysis showed that optimal shape has some advantages for cement mantle stress. However, more realistic 3-dimensional analysis which including bending effect, complex geometries etc. is needed in further research.

• Archives of Plastic Surgery
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• 제36권2호
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• pp.225-228
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• 2009

Purpose: Urethral reconstruction following failed hypospadias repair is difficult because of a severe shortage of the skin on ventral surface of the penis. We experienced a successful reconstruction of a failed hypospadias repair using the radial forearm free flap. So we present our case. Methods: A 16 - year - old boy had a proximal shaft hypospadias and had been taken a transverse preputial island flap but it completely broke down. There was no spare skin on the shaft of the penis. So we reconstructed a neo - urethra and the ventral skin of the penis with the radial forearm free flap. Results: Postoperatively he made relatively good process. The urethral catheter was maintained for 10 days and self - voiding was started. The suprapubic catheter was removed at the postoperative 30th day after control of cystitis. The postoperative appearance of the penis is acceptable and a straight erection is achieved. Conclusion: In the scarred penis with hypospadias, the radial forearm free flap transfer is a reliable reconstructive method for the neo - urethra and the ventral skin of the penis.

• 대한치과보철학회지
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• 제37권1호
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• pp.127-133
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• 1999

The purpose of this study was to compare the fracture strength of the IPS Empress ceramic crown according to the occlusal depth (1.5mm, 2.0mm, 2.5mm) and axial inclination ($4^{\circ},\;8^{\circ},\;12^{\circ}$) of the upper first premolar. After 10 metal dies were made fir each group, the IPS Empress ceramic crowns were fabricated and each crown was cemented on each metal die with resin cement. The cemented crowns mounted on the testing jig were inclined 30 degrees and a universal testing machine was used to measure the fracture strength. The results were : 1. The fracture strength of the ceramic crown with 2.5mm depth and $12^{\circ}$ inclination was the highest (630N). Crowns of 1.5mm depth and $4^{\circ}$ inclination had the lowest strength(378N). There were no significant differences of the fracture strength by axial inclination in same occlusal depth group. 2. The fracture mode of the crowns was similar. Most of fracture lines began at the loading area and extended through proximal surface perpendicular to the margin, irrespective of occlusal depth.

• Advances in pediatric surgery
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• 제11권2호
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• pp.171-174
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• 2005

Chronic duodenal obstruction related to a congenital web is a rare anomaly, and is sometimes difficult to diagnose preoperatively. A case of partial duodenal obstruction by a foreign body in a 10-year-old girl with a congenital duodenal web is presented. She had a year history of intermittent epigastric discomfort without nausea, vomiting or growth retardation. Upper gastrointestinal series and gastroduodenoscopy disclosed a perforated web in the 2nd portion of the duodenum and a dark go stone just proximal to the web. The web was partly excised through a longitudinal duodenotomy crossing over the web. The Ampulla of Vater was located at 7 o'clock on the posterior surface of the duodenal web and was preserved. The duodenum was closed in transverse fashion. In cases of a longstanding duodenal foreign body, a congenital web should be considered.

• Animal cells and systems
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• 제16권6호
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• pp.479-487
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• 2012

Biological attachment device is optimized in insect legs for attachment onto the variety of natural substrate. We have studied the microstructural characteristics of the tarsal appendages in the ladybug Harmonia axyridis using scanning electron microscopy to reveal the attachment system of their legs. The attachment devices are composed of claws and adhesive pads. The claws are connected with pretarsal segment, and their apical diverged hooks are developed to hold rough substrates. In contrast, the adhesive pads have an adhesive function onto smooth surface. The pads are interspersed at the ventral part of each tarsomere, and are composed of two kinds of hairy setae. The discoid tip seta (DtS) has a spoon-shaped endplate usually with a rounded concave structure, whereas the pointed tip seta (PtS) has a pointed tip, usually with a hooked endplate. While the PtS is broadly localized concentrically on the marginal area of both the proximal and distal pads, the DtS can be seen at the central areas of each adhesive pad except for the hind legs. Our findings demonstrate the presence of the direction-dependence pattern of the fibrillar system as well as a functional modification of the tenent setae to achieve proper contact with almost any kind of substrates.

• 한국자기공명학회:학술대회논문집
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• 한국자기공명학회 2002년도 International Symposium on Magnetic Resonance
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• pp.90-90
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• 2002

Syndecans, transmembrane heparan sulfate proteoglycans, are coreceptors with integrin in cell adhesion process. It forms a ternary signaling complex with protein kinase C and phosphatidylinositol 4,5 bisphosphate (PIP2) for integrin signaling. NMR data indicates that cytoplasmic domain of syndecan-4 (4L) undergoes a conformational transition in the presence of PIP2, forming oligomeric conformation. The structure based on NMR data demonstrated that syndecan-4L itself forms a compact intertwined symmetric dimer with an unusual clamp shape for residues Leu$^{186}$ -Ala$^{195}$ . The molecular surface of the syndecan-4L dimer is highly positively charged. In addition, no inter-subunit NOEs in membrane proximal amino acid resides (Cl region) has been observed, demonstrating that the Cl region is mostly unstructured in syndecan-4L dimmer. However, the complex structure in the presence of PIP2 induced a high order multimeric conformation in solution. In addition, phosphorylation of cytoplasmic domain induces conformational change of syndecan-4, resulting inhibition of PKC signaling. The NMR structural data strongly suggest that PIP2 promotes oligomerization of syndecan-4 cytoplasmic domain for PKC activation and further induces structural reorganization of syndecan for mediating signaling network in cell adhesion procedure.

• Journal of Chest Surgery
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• 제27권6호
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• pp.489-493
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• 1994

Our patient was a 2.3 kg, male of 33 weeks gestation and spontaneous vaginal delivery. Copious salivary secretion, mild aspiration pneumonia episode due to tracheoesophageal fistula and intermittent cyanotic appearance due to hypoxia were noted shortly after birth. Head up position, frequent upper pouch suction, and adequate fluid and antibiotic therapy were done in incubator. Combined Chest and abdominal film was revealed gas in the stomach and an haziness in right chest with mediastinal shift to the right side. Esophagogram revealed markedly dilated proximal esophagus as blind pouch, and Two dimensional echocardiography showed the Ventricular Septal Defect. The conclusion was congenital esophageal atresia with tracheoesophageal fistula, Vogt-Gross type C, Waterston Risk Category B. Surgical correction with Beardmore anastomosis was performed extrapleurally through 3rd rib bed after the cannulation of umbilical vein and preliminary gastrostomy. The fistula was closed by triple ligation and the upper pouch was then brought down to the presenting surface of the lower esophageal segment that incised, and end to side anastomosis was underwent using interrupt suture placed through the full thickness of both upper pouch and lower esophageal segment. The postoperative patient was well tolerated and recovered uneventfully, permitted feeding on 7th postoperative day after esophagogram.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.345-349
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• 2005

Objective: Anterior screw fixation provides the best anatomical and functional results for type II odontoid process fracture (type II-A, II-N, and II-P) with intact transverse ligament. The purpose of this study is to evaluate the usefulness of the 4.5mm diameter, cannulated Herbert screw in anterior screw fixation. Methods: From Jan. 2003 to Feb. 2004, consecutive 10cases of type II odontoid process fractures were treated with anterior screw fixation using a Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. It was originally developed for treating scaphoid fractures. Results: There were 8male and 2female patients whose ages ranged from 15 to 67years (mean 42.1years). The fracture type was type II-A in 4patients, II-N in 3 patients, and II-P in 3 patients. The fracture line was oblique downward and backward in 6cases, oblique downward and forward in 1 case, and horizontal in 3cases. The range of follow-up was 5 to 18months (mean 12months). Bone fusions were achieved in all cases without any instrumental failures or postoperative complications. Conclusion: The Herbert screw is very useful in anterior fixation for type II odontoid process fracture. This series showed successful results also in type II-A odontoid fracture when treated with the Herbert screw, but further more studies are required.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.288-295
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• 1998

The microleakage of direct-access Class 2 restorations was evaluated. Cavities were prepared at mesial and distal proximal enamel surfaces of 20 extracted human molars through buccal window. Prepared cavities were filled with Ketac-Fil, Ketac-Silver, and Fuji II LC, following manufacturer's instructions. 4 specimens of each restorations were made through sectioning 1/4 of bucco-lingual length mesio-distally after thermocycling between $5^{\circ}C$ and $60^{\circ}C$ and imerging 0.5% basic-fuchsin dye solution. Leakage at both occlusal and gingival margin of each specimen was scored 0 to 3 with stereomicroscope. The results were as follows: 1. At occlusal margin, leakage in Ketac-Fil group was more than Ketac-Silver and Fuji II LC group (ANOVA p<0.05) and there was no significant difference between Ketac-Silver and Fuji II LC group(p>0.05), and at gingival margin, there was no significant difference amang materials (p>0.05). 2. Occlusal margin leaked more than gingival margin in Ketac-Silver and Fuji II LC group (t-test p<0.05). 3. Leakage was different according to bucco-lingual location in Ketac-Fil and Fuji II LC group, and lingaul specimen exhibited more leakage(ANOVA p<0.05).

• The Journal of Korean Physical Therapy
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• 제33권1호
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• pp.40-46
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• 2021

Purpose: This study compared the muscle activity of the lower limb according to the three types of fixed angles of the ankle joint during a lunge exercise. Methods: Twenty healthy subjects performed the lunge motion in a trial including the three types of fixed angle. The lunge motion with a neutral, 20° dorsiflexion, and 20° plantarflexion of the ankle joint were randomized and measured repeatedly. The muscle activity of the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST) was measured by surface electromyography. Results: In the change in ankle joint angle, the RF, VL, BF, and ST muscle activity showed significant differences (p<0.05). In the 20° dorsiflexion position, the muscle activity of VL, BF, and ST showed a significant decrease compared to that in the neutral position (p<0.017). The muscle activity of RF and VL in the neutral position was greater than that in the 20° plantarflexion position (p<0.017). Only the muscle activity of the BF in the 20° plantarflexion position was significantly greater than the 20° dorsiflexion position (p<0.017). Conclusion: These results revealed a difference in the muscle activity of lower extremities in the proximal region according to the angle of the ankle joint during the lunge.