• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.90-95
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• 2008

Purpose: We wanted to assess the accuracy of ultrasound for detecting abnormality of the long head of the biceps tendon in patients with rotator cuff disorders. Materials and Methods: Between January 2006 and March 2007, we reviewed the arthroscopic findings of biceps tendons in 67 patients with rotator cuff disorder and who underwent ultrasonography pre-operatively. The patients' average age was 58 years and there were 41 males and 26 females. The statuses of the biceps tendons were described as 'normal', 'dislocation', 'subluxation', 'partial or complete tears', and 'tendinopathy'. We investigated the correspondence between the arthroscopic and ultrasonographic findings. Results: On ultrasonography, the biceps tendons were 'normal' in 37 patients and 'abnormal' in 30 patients. On arthroscopy, 5 biceps tendons turned out to have partial tears, which were 'normal' on ultrasonography. On the other hand, 8 biceps tendons were 'normal' which were 'abnormal' on ultrasonography. Three dislocations and 4 complete tears of biceps tendons were identified on arthroscopy, and all of them were detected by ultrasonography. Of the 20 cases of 'tendinopathy' seen on ultrasonography, 15 patients had partial tears and the remaining 5 patients were normal on arthroscopy. Conclusion: Ultrasonography is accurate for detecting some biceps pathologies, such as dislocation or complete tear, but it is not accurate for the detection of partial tear.

• Korean Journal of Materials Research
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• v.28 no.3
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• pp.174-181
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• 2018

Three kinds of STS304-Zr alloys were fabricated by varying the Zr content, and their microstructure and fracture properties were analyzed. Moreover, we performed heat treatment to improve their properties and studied their microstructure and fracture properties. The microstructure of the STS304-Zr alloys before and after the heat treatment process consisted of ${\alpha}-Fe$ and intermetallics: Zr(Cr, Ni, Fe)2 and Zr6Fe23. The volume fraction of the intermetallics increased with an increasing Zr content. The 11Zr specimen exhibited the lowest hardness and fine dimples and cleavage facets in a fractured surface. The 15Zr specimen had high hardness and fine cleavage facets. The 19Zr specimen had the highest hardness and large cleavage facets. After the heat treatment process, the intermetallics were spheroidized and their volume fraction increased. In addition, the specimens after the heat treatment process, the Laves phase (Zr(Cr, Ni, Fe) 2) decreased, the Zr6Fe23 phase increased and the Ni concentration in the intermetallics decreased. The hardness of all the specimens after the heat treatment process decreased because of the dislocations and residual stresses in ${\alpha}-Fe$, and the fine lamellar shaped eutectic microstructures changed into large ${\alpha}-Fe$ and spheroidized intermetallics. The cleavage facet size increased because of the decomposition of the fine lamellar-shaped eutectic microstructures and the increase in spheroidized intermetallics.

• Journal of the Korean Arthroscopy Society
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• v.9 no.2
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• pp.194-200
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• 2005

Purpose: To evaluate the short-term follow up outcome and the effectiveness of arthroscopic vertical shift of anteroinferior capsulolabral complex, plication of AIGHLC (anterior band of inferior glenohumeral ligament complex) and thermal capulorraphy, posteroinferior suture plication, rotator interval closure as an adjuncts in recurrent instability of megafrequency with night time dislocation. Materials & Methods: From March 1998 to February 2004, we have had 18 shoulders out of 156. All of the cases have been night time dislocation above more one time. The age were average 29.4$(21{\sim}37)$ year old. The average follow up were 21.1 $(12{\sim}45)$months We checked Rowe score and ROM at pre-operation, post-operation 6 months,1 year & last follow up period. Results: Above good results were 16 cases(88.9%). The excellent were 6 cases, good were 10, fair 1, poor 1. Conclusions: In recurrent anterior shoulder dislocation in greater than 50 frequency, arthroscopic stabilization can be an alternative technique for selected patients against open inferior capsular shift. But more long ter n follow up and large materials will be needed in the future study.

• Clinics in Shoulder and Elbow
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• v.9 no.2
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• pp.189-195
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• 2006

Purpose: To analyze the result of the accurate open reduction of acromioclavicular (AC) joint and pin fixation, coracoclavicular (CC) screw fixation without CC ligament repair for AC joint injuries. Materials and Methods: Between January 2000 and December 2003, seventeen cases with at least one year follow-up among twenty-one cases underwent operation for AC-CC ligament injuries. A transverse incision approximately 5 cm in length was made over the clavicle, and the AC joint was reduced accurately. Under the image intensifier, a cannulated screw and washer were inserted for the CC ligament. Two Steinman pins were inserted for the AC joint and the AC ligament was repaired with nonabsorbable suture. Gentle passive range of motion was begun postoperative 2 weeks. The pins were removed at $6{\sim}8$ weeks and the screw was removed at $10{\sim}12$ weeks. The results were evaluated by a distance between AC and CC joints on plain films and ASES score at last follow-up. Results: At the last follow-up, there was no limitation of motion and average ASES score was 96($86{\sim}100$ points). There was no failure showing over 5 mm difference of distance compared to opposite side on the plain films. Seven cases had the skin damages and local infection due to pin migration and three cases showed the loosening of CC screw. Conclusion: We could have satisfactory results by accurate reduction of AC joint and simple pins and screw fixation for AC-CC ligament injuries.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.92-98
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• 2010

Purpose: To analyze results of treating acromioclavicular injuries using clavicle hook plates. Materials and Methods: Between February 2008 and April 2010, 18 patients with acromioclavicular joint injury treated by clavicle hook plates were reviewed. Using the Rockwood classification, 7 dislocations were classified as type III injuries and 11 as type V injuries. Implant removal was done at least 3 months from initial fixation. Simple X-rays were taken for comparing the state of reduction, and clinical outcomes were evaluated by the Korean Shoulder Scoring System and the American Shoulder Elbow Society score. The average follow-up period was 9 months. Results: On weight bearing X-rays, the average coracoclavicular distance showed a 114% increase compared to the contralateral side at the time of injury. It decreased to 23% by the last follow-up. The mean Korean Shoulder Scoring System and the American Shoulder Elbow Society score were 80 and 74 at the last follow-up. Conclusion: The immediate stability these plates provide allows rapid rehabilitation. Clavicle hook plate fixation for acromioclavicular joint dislocation is considered an effective method for ensuring satisfactory results both radiologically and clinically.

• Clinics in Shoulder and Elbow
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• v.13 no.1
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• pp.34-39
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• 2010

Purpose: The purpose of this study was to present methods and results for the modified Phemister operation, with a suture anchor added for augmentation of the conoid ligament in cases of acute dislocation of the acromioclavicular joint. Materials and Methods: We evaluated 14 cases of acute dislocation of the acromioclavicular joint. This included 11 cases of Rockwood type 3, and 3 cases of type 5. The mean age of patients was 45.2 years. We operated on them using an anchor for augmentation of the conoid ligament in the modified Phemister operation. The average follow-up period was 14 months and post-operative clinical analysis was conducted using the Weitzman classification, VAS Score, Constant Score and KSS Score. Results: According to Weitzman scores, 13 cases were evaluated as excellent, and one case was good. They had mean joint ranges of forward elevation of $170.7^{\circ}$, lateral elevation of 166.4, external rotation of 68.2, and internal rotation to the level of T7. The mean VAS Score was 1.9, mean Constant Score 90.8, and the mean KSS Score 91. Radiologic analysis indicated that all cases had a good result. Conclusion: The modified Phemister operation with a suture anchor added for augmentation of the conoid ligament is very effective clinically in acute dislocations of the acromioclavicular joint.

• Journal of the Korean Society for Heat Treatment
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• v.19 no.1
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• pp.10-19
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• 2006

Microstructure and morphology of precipitates in $Ni_3Al$- and TiAl-based intermetallics containing carbon have been investigated in terms of transmission electron microscopy(TEM). In an $L1_2$-ordered $Ni_3Al$ alloy with 4 mol.% of chromium and 0.2~3.0 mol.% of carbon, fine octahedral precipitates of $M_{23}C_6$ type carbide were formed in the matrix by aging at temperatures around 973 K after solution annealing at 1423 K. TEM examination revealed that the $M_{23}C_6$ phase and the matrix lattices have a cube-cube orientation relationship and keep partial atomic matching at the {111} interface. After prolonged aging or by aging at higher temperatures, the $M_{23}C_6$ precipitates then adopt a rod-like morphology elongated parallel to the <100> directions. In the $L1_0$-ordered TiAl containing 0.1~2.0 mol.% carbon, TEM observations revealed that needle-like precipitates, which lie only in one direction parallel to the [001] axis of the $L1_0$ matrix, appear in the matrix and preferentially at dislocations. Selected area electron diffraction(SAED) patterns analyses have shown that the needle-shaped precipitate is $Ti_3AlC$ of perovskite type. The orientation relationship between the $Ti_3AlC$ and the $L1_0$ matrix is found to be $(001)_{Ti3AlC}//(001)_{L10\;matrix}$ and $[010]_{Ti3AlC}//[010]_{L10\;matrix}$. By aging at higher temperatures or for longer period at 1073 K, plate-like precipitates of $Ti_2AlC$ with a hexagonal structure are formed on the {111} planes of the $L1_0$ matrix. The orientation relationship between the $Ti_2AlC$ and the $L1_0$ matrix is $(0001)_{Ti2AlC}//(111)_{L10\;matrix}$ and $_{Ti2AlC}//_{L10\;matrix}$.

• Journal of Yeungnam Medical Science
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• v.10 no.1
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• pp.114-126
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• 1993

The fractures of the cervical spine are relatively uncommon, but they may cause serious neurologic deficits temporarily or permanently. So, it is very important to treat the patients early by way of exact evaluation for the sites and the mechanisms of the injuries. The authors reviewed retrospectively 188 cervical spinal fractures in 100 patients from Sep. 1984 to Aug. 1990. Commonly involved levels were $C_5$ and $C_6$ in lower cervical level and $C_2$ in upper cervical level and the sites in each spine were body, lamina and odontoid process. The hyperflexion injury was the most common type of the cervical spinal fractures occupying 53% of all cervical fractures and cause more multiple fractures(2.26 fractures/patient) than in hyperextension(1.68 fractures/patient). In hyperflexion injuries, body, transverse and spinous process were commonly involved but lamina fracture was relatively common in hyperextension injury. The dislocations associated with fractures were developed most commonly in hyperflexion injury and 70% of these were anterior dislocation and the most commonly involved levels were $C_{5-6}$ and $C_{6-7}$. In conclusion, hyperflexion injury needs more close examination for the entire spinal levels than injuries of other mechanisms because it results in more severe fractures with or without dislocation and relatively frequent multiple fractures in different levels.

• Korean Journal of Materials Research
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• v.5 no.2
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• pp.169-177
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• 1995

The diffusion barrier property of 100-nm-thick titanium nitride (TiN) film between Cu and Si was investigated using sheet resistance measurements, etch-pit observation, x-ray diffractometry, Auger electron spectroscopy, and transmission electron microscopy. The TiN barrier fails due to the formation of crystalline defects (dislocations) and precipitates (presumably Cu-silicides) in the Si substrate which result from the predominant in-diffusion of Cu through the TiN layer. In contrast with the case of Al, it is identified that the TiN barrier fails only the in-diffusion of Cu because there is no indication of Si pits in the Si substrate. In addition, it appears that the stuffing of TiN does not improve the diffusion barrier property in the Cu/TiN/Si structure. This indicates that in the case of Al, the chemical effect that impedes the diffusion of Al by the reaction of Al with $TiO_{2}$ which is present in the grain boundaries of TIN is very improtant. On the while, in the case of Cu, there is no chemical effect because Cu oxides, such as $Cu_{2}O$ or CuO, is thermodynamically unstable in comparison with $TiO_{2}$. For this reason, it is considered that the effect of stuffing of TiN on the diffusion barrier property is not significant in the Cu/ TiN/Si structure.

• Journal of the Korean Vacuum Society
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• v.11 no.1
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• pp.50-58
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• 2002

The growth of GaN films on Si substrate has many advantages in that Si is less expensive than sapphire substrate and that integration of GaN-based devices with Si substrate is easier The difference of lattice constant and thermal expansion coefficient between GaN and Si is larger than those between GaN and sapphire. However, which results in many defects into the grown GaN. In order to obtain high duality GaN films on Si substrate, we need to reduce defects using the buffer layer such as AlN. In this study, we prepared three types of AlN buffer layer with various crystallinity on Si (111) substrate using MOCVD, Sputtering and MOMBE methods. GaN was grown by MOCVD on three types of AlN/Si substrate. Using TEM and XRD, we carried out comparative investigation of growth and properties of GaN deposited on the various AlN buffers by characterizing lattice coherency, crystallinity, growth orientation and defects formed (voids, stacking faults, dislocations, etc). It is found that the crystallinity of AlN buffer layer has strong effects on growth of GaN. The AlN buffer layers grown by MOCVD and MOMBE showed the reduction of out-of-plane misorientation of GaN at the initial growth stage.