• Korean Journal of Cognitive Science
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• v.32 no.1
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• pp.1-53
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• 2021

The aim of this study was to analyze word frequency effects on eye fixation duration in Korean reading with a one-boundary diffusion model and to show how these phenomena differ between adults (20-28yrs) and adolescents (13-14yrs). We predicted that the drift rate parameter in the boundary diffusion model would reflect the information processing of the fovea during silent reading. Through an eye movement tracking experiment while controlling word properties such as the word frequency and the age of acquisition, Experiment 1 and Experiment 2 show that the information processing pertaining to words to be placed in the fovea is connected to the drift rate of the one-boundary diffusion model parameters. In Experiment 1,in the adult group, the mean difference in the fixation time in the response proportion between the presence of high-frequency condition and low-frequency condition in the adult group was higher in quantile 0.9 than it was in the 0.1 quantile, but in the adolescent group, the mean difference in the fixation time in the response proportion between the two conditions was not significantly in the 0.9 quartile.In Experiment 2, the mean difference in the fixation time in the response proportion between early-acquired condition and late-acquired condition in both groups was also higher in the quantile 0.9 than in the 0.1 quantile. The distribution of the two conditions in the both groups was positively skewed, and the difference showed the same pattern found in the results of Ratcliff(Ratcliff & McKoon, 2008). Based on the experimental results, we propose one-boundary diffusion model as a tool to explain word property effects and individual differences in reading. In particular, we suggest that the drift rate parameter in the boundary diffusion model reflects the information processing of the fovea during reading. In addition, the results show that one-boundary diffusion model can be used to predict the aforementioned phenomena in reading.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.3
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• pp.276-280
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• 2011

BSSRO (bilateral sagittal split ramus osteotomy) is an effective surgical method for maxillofacial deformities. Rigid fixation using a plate and screws can stabilize bony segments and induce early mouth opening. Though this procedure has a low complication rate, normal function and esthetic recovery is achieved through proper and early management of the complications. Complications consisting of temporomandibular disorders, sensory disturbances due to inferior alveolar nerve damage, open bite, malunion or nonunion, and facial nerve palsy occur, but these rarely develop. Facial nerve palsy causes the muscles involved in facial expression to depress, which results in ocular dryness or retinal damage. When facial nerve palsy develops, early management involving steroid medication and physical therapy is effective. In the case of severe damage, surgical intervention should be considered. A 20-year-male patient came to the oral and maxillofacial surgery department for orthognathic surgery. The mandible was set back by BSSRO under general anesthesia. Facial nerve palsy was observed on the left side of the face: steroid and vitamins were administered early and physical therapy was performed daily. These forms of management can aid in function and allow for gradual esthetic recovery. Presumed causes were excessive soft tissue retraction or soft tissue injury by the osteotome at the horizontal osteotomy of the ramus. Careful dissection, retraction and a precise osteotomy are needed for protection of the facial nerve. If nerve damage is observed, early management can help in the recovery of facial nerve function and esthetics.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.1
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• pp.17-24
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• 2005

We experimented on growth in light and production of hydrogen and organic matters in dark fermentation by using C. reinhardtii. In the light, growth rate of C. reinhardtii following $CO_2$ fixation was proportional to consumption rate of nitrogen source. And the starch in cell was accumulated more when the period of culture was lengthened more. But the accumulation rate of starch in cell was decreased when the growth rate of cell become dull. In the dark fermentation, the production volume and production rate of hydrogen were the highest value in the mid exponential state among other states. The utilization efficiency of substrate was better in the early exponential state than other states. In production of organic matters, acetic acid didn't change remarkably and ethanol showed the highest value in early exponential state.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.4
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• pp.303-316
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• 1993

The auricular cartilage grafts have been widely used in replacement of the temporomandibular joint disk. Cartilage grafts itself have a low metabolism and high survival rate after grafting. In processing the grafting materials, it was important to preserve the properties of chondrocyte proper. We used 15% glycerol and 10% DMSO (Dimethyl Sulfoxide) solutions for cartilage fixation before deep freezing. We have performed the allogenic auricular cartilage graft in the temporomandibular joint of 20 rabbits which 10 specimen was treated with 15% glycerol and the other 10 specimen was treated with 10% DMSO respectively and examined in 1, 2, 4, 6 and 8 weeks after operation histopathologically. The result were : 1. Inflammatory cell infiltration around the grafted material appeared more glycerol groups than DMSO groups at 1 week, but each group has no differences after 2 weeks. 2. Degenerative changes of grafted auricular chondrocytes were more deveolped in glycerol group than DMSO groups till 4 weeks, but there were no differences between two groups after 6 weeks. 3. Fibrous union between grafted fragment and mandibular condyle was prominent in DMSO group. 4. Vascular proliferation of the grafted auricualr cartilage was more developed in DMSO groups than glycerol group in early stage. 5. Amount of the additional growth of grafted auricular cartilage was more existed in DMSO groups than glycerol group. 6. General survival rate after grafting was more prominent in DMSO group. In summary, allogenic auricular cartilage grafts treated with 15% glycerol and 10% DMSO solution have supported to survivalbility as a cryopreservative agents, especially DMSO groups have little inflammatory cell infiltration in early stages and degenerative changes and additional growth are more prominent than glycerol groups.

• Journal of Yeungnam Medical Science
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• v.5 no.1
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• pp.61-67
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• 1988

The treatment of tibial shaft fracture has become one of the most controversial subjects in orthopedic surgery. Comminuted, segmental and rotationally unstable fractures or bone defect at fracture site have problems of the fixation. The interlocking nail solve these problems. We have experienced 8 cases of the tibial shaft fractures treated with interlocking nail from 1986 to 1988. Authors analysed these cases and our own clinical study. The results were as follows. 1. The average bone union rate was about 15 weeks. 2. The interval between operation and crutch walking was 4:3 weeks. 3. The merits of this operation were the short hospitalization and early adaptation of social activity. 4. The advantage is be able to do early ambulation without following muscular atrophy or joint stiffness. 5. The results were assessed on clinical examination and radiographic appearance by Hamza et al. An excellent results were 7 cases and good result was 1 case.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.71-74
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• 1994

In cementless total hip arthroplasty(THA), an initial stability of the femoral component is mandatory to achieve bony ingrowth and secondary long term fixation. Bone ingrowth depends strongly on relative micromotion and stress distributions at the interface. Primary stability of the femoral component can be obtained by minimizing the magnitude of relative micromotions at bone-prosthesis interface, Hence an accurate evaluation of interface behavior and stress/strain fields in the bone implant system may be relevant for better understanding of clinical situations and improving THA design. However, complete evaluation of load transfer in the bone remains difficult to assess experimentally, Hence, recently finite element method (FEM) was introduced in orthopaedic research field to fill the gap due to its unique capacity to evaluate stress in structure of complex shape, loading and material behavior. The authors developed the 3-dimensional numerical finite element model which is composed of totally 1179 elements off and 8 node blick. We also analyzed the micromotions at the bone-stem interface and mechanical behavior of existing bone prosthesis for a loading condition simulating the single leg stance. The result indicates that the values of relative motion for this well fit Multilock stem were $150{\mu}m$ in maximum, $82{\mu}m$ in minimum, and the largest relative motion developed in medial region of proximal femur with anterior-posterior direction. The proximal region of the bone was much larger in motion than the distal region and the stress pattern shows high stress concentration on the cortex near the tip of the stem. These findings indicates that the loading in the proximal femoral bone in the early postoperative situation can produce micromotions on the interface and clinically cementless TEA patient should not be allowed weight bearing strictly early in the postoperative period.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.6
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• pp.816-831
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• 1998

Bony fixation of implants during the early phase of healing is important in order to get secondary stability of the implant assuring the success of the treatment. Because the successful placement of the implant is limited by the quality and quantity of bone, other agents which stimulate bone formation in the peri-implant spaces has been illustrated. Platelet-derived growth factor (PDGF) has been shown to regulate DNA and protein synthesis in bone cells in vitro and to interact synergistically to enhance soft tissue wound healing in vivo. The purpose of this study was to evaluate bone promotion around implants which were augmented with sagittal split osteotomy or autogenous veneer bone graft using the platelet derived growth factor(PDGF). After placement of newly designed twenty four screw-type implants, which were 12mm in length and 4mm in diameter in 6 dogs. $4{\mu}g$ of PDGF B/B was applied with surgicel carriers. The dogs were sacrificed at 3 days, 1, 2, 3, 6, and 12 weeks after implantation. Specimens were examined clinically, radiographically, histologically, and histomorphometrically. The results were as follows: 1. Clinically and radiologically, there was no significant difference in bone formation and healing pattern between experimental and control group. 2. In autogenous veneer bone graft group, bone formation was observed at 1st week in the experimental groups but 2nd week in the control groups. At 3rd week, the expeimental groups showed more bone formation comparing to the control groups. 3. In sagittal split osteotomy group, bone formation was observed at 1st week in both groups. But the experimental groups showed more bone formation comparing to the control groups after 2nd week. 4. The bone growth rate of experimental group was more rapid than that of control group. These results indicated that PDGF did not affect the initiation of new bone formation, but it accelerated the bone formation at the early period.

• Journal of Trauma and Injury
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• v.22 no.2
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• pp.254-259
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• 2009

Purpose: Pelvic trauma is a serious skeletal injury with high mortality. Especially in cases of severe injury trauma, treatment outcomes depend on early diagnosis and intervention. We expect trauma surgeon to play an important role in the management of severe multiple trauma patients. Methods: A retrospective study was performed on pelvic trauma patients with hemodynamic instability between March 2005 and September 2009. We divided the time period into period I (March 2005~Feburary 2009) and period II (March 2009~September 2009). The trauma surgeon and team started to work from period II. Data were collected regarding demographic characteristics, mechanism of injury, type of pelvic fracture, ISS(injury severity score), treatment modality, transfusion requirement, time to definitive treatment, and mortality. Results: During period I, among 7 hemodynamically unstable patients, 4(57.1%) patients died. However during Period II, only one of 6(16.6%) patients died. The demographic data and injury scores showed no differences between the two time periods, but the time to definitive treatment was very short with trauma team intervention(14.4 hrs vs. 3.9 hrs). Also, the amount of transfusion was less(41.1 U vs. 13.9 U). With arterial embolization, early pelvic external fixation led to less transfusion and made patients more stable. Conclusion: This study demonstrated the importance of the trauma surgeon and the trauma team in cases of hemodynamically unstable pelvic trauma. Even with the same facility and resources, an active trauma team approach can increase the survival of severely injured multiple trauma patients.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.61-68
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• 1996

In Fibrous dysplasia(FD) of the jaws, the majority of cases can await the cessation of growth before surgical intervention, and it seems prudent to delay surgery whenever possible until growth has ceased. In craniofacial FD, however, the dangers of dystopia, dystopia and loss of vision may require early surgery to prevent or control cranio-orbital complications. Delaying surgery in those circumstances may be significantly detrimental to such patients. Conservative surgical management of FD is widely practised and we advocate an extension to this conservative treatment by combining surgical recontouring with appropriate osteotomies if indicated, to achieve an optimal esthetic and functional results in craniofacial FD. One case will be presented to illustrate the feasiblility of such combined treatment, to report the uneventful healing of osteotomies in the FD of the jaws, and to demonstrate the use of titanium miniplate fixation in dysplastic bone. The other case had expansile disease of the left facial and fronto-temporal bones and osteolytic change left mandible. This patient complained of severe spontaneous bleeding of left mandibular premolar area and it was suspected as central hemangioma of the left mandible and craniofacial FD. Angiogram disclosed generalized dilation of the external carotid artery and its branches, especially terminal branches of the left facial and inferior alveolar arteries. But no specific abnormalities, such as A-V shunt, venous lake, or early venous drainage, was seen. So it was diagnosed craniofacial FD with hypercellularity and generalized bony recontouring was performed via coronal and transoral approaches.

• Journal of Chest Surgery
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• v.21 no.4
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• pp.619-629
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• 1988

The increasing number of replacement of the substitute cardiac valves were seen in these 2 years. Out of a total 1,408 patients with cardiac valve replacement, 54 required replacement of the substitute valves. Fifty-nine substitute valves replaced were 43 in mitral, 14 in aortic and 2 in tricuspid positions; and they were 36 Ionescu-Shiley, 15 Hancock and 3 Angell-Shiley bioprosthetic valves and 3 St. Jude Medical and 2 Bjork-Shiley prosthetic valves. Primary tissue failure was the most frequent reason of replacement[38 patients] followed by paravalvular leak[9 patients], prosthetic valve endocarditis[6 patients] and valve thrombosis[1 patient] in order. The most pronounced pathology of the failed xenograft valves seen in the primary tissue failure group was calcification and fixation of the cusps with or without tear and defect of the cuspal tissue. The operative mortality rate was 7.4%. Fifty early survivors were followed up for a total of 82.6 patient-years and there was no late death. Actuarial survival rate was 92.3*3.8% at 6 years after surgery. Although the definite tendency toward early and accelerated degeneration of the xenograft valves has been seen in patients younger than 20 to 25 years of age, no strict age limit from where the tissue failure slows down could be determined. The requirement of the ideal substitute valves would be the durability of the recently developed mechanical prostheses armed with the low thrombogenicity of the bioprostheses. At the present time, the need of compromise in selection between less thrombogenic bioprosthetic and more durable mechanical valves should be stressed. The difficulty in choice is yet important in patients of middle age and children where the use of homograft valves may be one of the solution despite of certain limitations from sociomedical reasons.