• Journal of Trauma and Injury
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• v.19 no.2
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• pp.164-172
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• 2006

Background: The authors conducted a retrospective study to evaluate the mechanism of injury, the surgical techniques, the clinical features, the combined injuries, the treatment results, and the surgical complications in patients with atlantoaxial fracture/subluxations. Methods: The authors reviewed 71 cervical fracture/dislocations during a four-year period from September 2002 to August 2006. Among them, there were twenty one C1,2 fracture/subluxations. There were thirteen men (mean age : 43.5 years) and eight women (mean age : 50 years). Their follow-up period was at least 6 months, and the mean follow-up period was 9.6 months. Gardner-Wells tongs traction was used in all patients immediately on presentation. Surgical treatment was performed, depending on the pathologic conditions. Results: Of all 21 cases, 14 cases were injured in motor vehicle accidents, 5 were falls, and 2 were miscellaneous. There were four C1 fracture (5.6%), fourteen C2 fracture (66.7%), one C1 and 2 combined fracture (4.8%), and one C1-2 subluxation (4.8%). The C1 fractures in our series were classified as two Jefferson's fractures and two C1 lateral mass fracture. The C2 fractures were classified as one odontoid type I fracture, two odontoid type II fractures, five odontoid type III fractures, one hangman's fracture, and four C2 body tear-drop fractures. Atlantoaxial fractures were associated with six (28.6%) head injuries, four (19.0%) other spinal injuries, two (9.5%) chest injuries, and three (14.3%) spinal cord injuries. Surgical treatment was performed in nine cases, which included anterior odontoid screw fixation in two cases, transarticular screw fixation with iliac bone graft in one case, posterior fixation by using C2 pedicle screw and C3 lateral mass screw in three cases, lateral mass screw fixation C1-2 with iliac bone graft in one case, O(occipito)-C1-3-4 screw fixation in one case, posterior C2-3 wiring with allograft in one case, and halo vest in six cases. Conservative management was used in the rest of the patients in our trials. Bone fusion was complete in all cases. There were no operation-related complication, except one pin site infection in the case of halo vest. Conclusion: In this study, the choice of appropriate treatment according to the fracture types resulted in safe and effective management of unique atlantoaxial fracture/subluxations.

• Korean Journal of Plant Taxonomy
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• v.44 no.3
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• pp.222-232
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• 2014

The flora of vascular plants in Sumeunmulbaengdui wetland located in Hallasan National Park was surveyed 9 times from September, 2010 to May, 2014. This survey resulted in 236 taxa in total composed of 202 species, 2 subspecies, 27 varieties and 5 forms of 148 genera under 69 families. They were categorized by their life forms into 8 groups of 37 megaphanerophytes, 26 nanophanerophytes, 2 epiphytes, 3 chamaephytes, 84 hemicryptophytes, 33 geophytes, 21 hydrophytes, 30 therophytes. Among them, 10 taxa of Korean endemic plants and 9 taxa of rare and endangered plants were included. In addition, the floristic regional indicator plants were 43 taxa comprised of 3 taxa of grade V, 7 taxa of grade IV, 12 taxa of grade III, 8 taxa of grade II and 13 taxa of grade I. 2 species of alien plants, Erechtites hieracifolia Raf. and Taraxacum officinale Weber were found. Sustainable interest and protective measures to Sumeunmulbaengdui wetland are required, since this area is comparatively larger in size and higher in plant diversity than other Ramsar wetlands in Jeju-do Province.

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.643-648
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• 2010

Production of biodiesel from soybean oil catalyzed by Lewis acidic ionic liquids(ILs) containing metal chloride salts was investigated in this study. Metal chloride salts, such as $SnCl_2$, $ZnCl_2$, $AlCl_3$, $FeCl_3$ and CuCl, were screened for oil transesterification in the range of 363-423 K. Among these metal chlorides, tin chloride showed particularly high catalytic property for the oil transesterification. Similarly, among these Lewis acidic ionic liquid catalysts, $[Me_3NC_2H_4OH]Cl-2SnCl_2$ resulted in a high fatty acid methyl esters(FAMEs) content of 91.1% under the following reaction conditions: 403 K, 14 h, and a molar ratio of 1:12:0.9 (oil:methanol:catalyst). Unlike the pure tin chloride catalysts, Lewis acidic ILs containing tin chloride $[Me_3NC_2H_4OH]Cl-2SnCl_2$ catalyst could be recycled up to five times without any significant loss of activity by separating from the FAMEs with simple decantation. The Lewis acidity and high moisture-stability of this catalyst appeared to be responsible for the excellent catalytic performance. The effects of reaction time and the molar ratio of methanol/catalyst to oil on the FAMEs production were also studied in this work.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.1-6
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• 2000

Dentinogenesis imperfecta is an inherited disorder of dentin formation, usually exhibiting an autosomal dominant mode of transmission. Type I dentinogenesis imperfecta occurs in patients afflicted with osteogenesis imperfecta. Type II dentinogenesis imperfecta is not associated with osteogenesis imperfecta. Type III dentinogenesis imperfecta (Brandywine type) occurs in a racial isolate area in the state of Maryland. In all three types, teeth of both dentitions are affected with variable clinical appearances. The teeth are opalescent with the color ranging from bluish-gray to brown to yellowish. The dentin is abnormally soft, providing inadequate functional support to the overlying enamel. Although the enamel is normal, it fractures or chips away easily, exposing the occlusal and incisal dentin. The exposed soft dentin often undergoes rapid and severe functional attrition. The teeth exhibit bulb-shaped crowns with constricted cementoenamel junctions and thin roots. The teeth will exhibit varying stages of obliteration of the coronal and root pulpal chambers. The cementum, periodontal ligament and supporting alveolar bone appear normal. The enamel is normal. The mantle dentin remains nearly normal, whereas the remaining dentin is severely dysplastic. The dentinal tubules are disoriented, irregular, widely spaced, and usually larger than normal.

• The Korean Journal of Nuclear Medicine
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• v.15 no.2
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• pp.1-9
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• 1981

Bone scans with $^{99m}Tc-MDP$ (methylene diphosphonate) were obtained and analysed in 574 patients with biopsy-proven malignancy, who visited Seoul National University Hospital from April, 1979 to June, 1931. Clinical staging was done in all patients without bone scan information and compared with bone scan to determine the predictive value of bone scanning. 1. Primary site of the maligancies were lung in 152, breast in 97, stomach in 43, colon in 15, esophagus in 9, liver and pancreas in 11, kidney in 14, bladder in 27, prostate in 22, thyroid in 20, skin in 11, bone in 9, head and neck in 36, ovary and uterus in 17, hematopoietic and lymphoretic ular system in 33, nervous system in 10, and others in 9 cases. Primary site was not defined in 39 cases. 2. Bone scans were positive in 186 cases (32.4%), which, included 48 cases (31.6%) of lung cancer, 27 cases (27.8%) of breast cancer, 12 cases(28%) of stomach cancer, 6 cases(40%) of colon cancer, 6 cases(43%) of kidney tumor, 4 cases(15%) of bladder cancer, 14 cases(64%) of prostate cancer, 3 cases(15%) of thyroid cancer and 66 other cases. 3. Bone scans were suspicious in 64 cases (11.2%) which included 29 cases (19.1%) of lung cancer, 10 cases (10.3%) of breast cancer, 4 cases (9.3%) of stomach cancer, one case (7%) of colon cancer, 3 cases(11%) of bladder cancer, 2 cases(10%) of thyroid cancer and 15 other cases. 4. Out of 121 cases with early stage of malignancy (which included 20 cases of lung cancer in stage I, II, 38 cases of breast cancer, 13 cases of stomach cancer, 8 cases of kidney tumor, 14 cases of thyroid cancer in stage $I{\sim}III$, and 6 cases of colon cancer, 14 cases of bladder cancer, 8 cases of prostate cancer in stage $A{\sim}C$, bone scans were positive in 5 cases (4.1%) which included 3 cases of lung cancer one case of breast cancer and one case of prostate cancer, and considered as further advanced stage. Out of 121 cases with early stage of malgnancy, bone scans were suspicious in 21 cases (17.4%) which inlcuded 9 cases of lung cancer, 4 cases of breast cancer, 2 cases of stomach cancer, one case of colon cancer, 3 cases of bladder cancer, and 2 cases of thyroid cancer. From these results, we concluded bone scan was useful in detecting bone metastasis in patients of early stage of malignancy, determining prognosis and establishing therapentic plan.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.363-373
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• 2013

This study investigates the dispersion and behavior of Au and heavy metals in the water system (soil, AMD and stream sediment) at the abandoned Bonjeong gold mine, based on XRD, aqua regia, sequential extraction, and physico-chemical analyses. The XRD analyses targeted quartz and kaolinite in the mine waste soil and quartz and goethite in stream sediment. The physico-chemical analyses of AMD with increasing distance from water system showed that pH increased from 3.00 to 3.19 and Eh decreased from 450 to 396 mV. The Au content in AMD ranged from 0.68 to 0.97 mg/L upstream, but was not detected downstream. The Au content of stream sediment was 13.76 to 22.85 mg/kg. Sequential extraction from stream sediment revealed 10.84% exchangeable (STEP I), 11.09% carbonates (STEP II), 25.53% Fe-Mn oxides (STEP III), 26.62% organic matter (STEP IV), and 24.61% residual (STEP V).

• Journal of Food Hygiene and Safety
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• v.4 no.3
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• pp.177-184
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• 1989

Contents of inorganic compounds in various cereals (Rice: 62, Barley: 39, Soybean: 58, Unhulled barley: 59) collected from Youngnam Districts in 1989 were determined by the atomic absorption spectophotometer. The results abtained as follows: The ranges of zinc level in rice, barley, soybean and unhulled barley were 46.91-76.28 ppm, 42.24-77.06 ppm, 73.39-103.69 ppm and 48.08-272.49 ppm, and those of manganes in each samples were 4.96-14.75 ppm, 20.62-16.28 ppm, 23.31-42.488 ppm and 23.52-30.15 ppm respectively. The ranges of iron level in rice, barley, soybean and unhulled barley were 65.38-141.33 ppm, 52.22-133.25 ppm, 106.32-240.20 ppm and 66.44-108.64 ppm, and those of calcium in each samples were 10.25-33.67 ppm, 68.94-136.62 ppm, 492.20-967.84 ppm and 75.30-165.85 ppm respectively. Meanwhile, contents of sodium in rice, barley, soybean and unhulled barley were 291.60-453.60 ppm, 462.25-773.60 ppm, 463.83-792.67 ppm and 777.90-950.90 ppm and those of potassium in above samples were 716.00-1180.60 ppm, 1363.60-1686.00 ppm, 2233.84-2792.67 ppm and 2042.10-2141.46 ppm respectively.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.397-409
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• 2014

In this study, the assessment scheme has been developed to evaluate the ecological function of rivers which were changed by the river improvement project. The evaluating factors are composed of physical structure in river channels and ecological connectivity in river areas, and each value of the factors is quantified based on 4 and 2 variables, respectably. This scheme was applied to past (1918, before artificial river improvement) and present Mankyung River area. A GIS model was adopted for calculating, analysing, and presenting river ecological conditions using the 204 grids and 7 reaches in study area. Comparison results show that the evaluation grade was decreased in both factors after river improvement. The main causes of lower grade (from II to IV) for physical structure are the river straightening and crossing structures. The reduction (from II to III) in ecological connectivity grade effected by linear fragmentation due to roads and rails is found to be greater than areal fragmentation due to land-use. In particular, it is also found that a high degree of ecological connectivity in 1918 was distributed along the river, but that one in 2007 showed a tendency to scatter because of the construction of levee and increase of urbanized area.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.652-672
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• 1996

Dysfunction of the inferior alveolar nerve may result from trauma, diseases or iatrogenic injury. The development and refinement of an objective method to evaluate this clinical problem is highly desirable and needed, especially concerning for an increasing medico-legal issue. Evoked potential techniques have attracted considerable attention as a means of assessing the function and integrity of nerve pathways. The purpose of this study was to characterize the Sensory Evoked Potentials(SEPs) and Somatosensory Evoked Potentials(SSEPs) elicited by electrical stimulation of mental nerve. SEPs and SSEPs were measured and analyzed statistically before and after needle injury on the inferior alveolar nerve of Sprague-Dawalye rats. Measuring SEPs was more sensitive in evaluation of the recovery of sensory function from inferior alveolar nerve injury then measuring SSEPs but we measured SSEPs in the hope of providing a safe, simple and objective test to check oral and facial sensibility, which is acceptable to the patient. We stimulated mental nerve after needle injury on the inferior alveolar nerve and SEPS on the level of mandibular foramen and SSEPs on the level of cerebral cortex were recorded. Threshold, amplitude, and latency of both of SEPs and SSEPs were analyzed. The results were as follows ; 1. Threshold of SEPs and SSEPs were $184{\pm}14{\mu}A$ and $164{\pm}14{\mu}A$ respectively. 2 SEPs were composed of 2 waves, i.e., N1 N2 in which N1 was conducted by II fibers and N2 was conducted by III fibers. 3. SSEPS were composed of 5 waves, of which N1 and N2 shower statistically significant changes(p<0.01, unpaired t-test). 4. SEPs and SSEPs were observed to be abolished immediately after local anesthesia and recovered 30 minutes later. 5. SEPs were abolished immediately after injury. N1 of SSEPs was abolished immediately and amplitued of N2 was decreased($20.7{\pm}12.2%$) immediately after 23G needle injury, but N3, N4 and N5 did not change significantly. Recovery of waveform delayed 30 minutes in SEPs and 45 minutes in SSEPs. 6. The degree of decrease in amplitude of SEPs and SSEPs, after 30G needle injury was smaller than those with 23G. SEPs recorded on the level of mandibular foramen were though to be reliable and useful in the assessment of the function of the inferior alveolar nerve after injury. Amplitude of SSEPs reflected the function and integrity of nerve and measuring them provided a safe, simple and abjective test to check oral and facial sensibility. These results suggest that measuring SEPs and SSEPs are meaningful methods for objective assessment in the diagnosis of nerve injury. N1 and N2 of SSEPs can be useful parameters for the evaluation of the nerve function following a needle injury.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2004.01a
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• pp.1-226
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• 2004

I. Title APMC'03(2003 Asia Pacific Microwave Conference) II. Objecuve $\bigcirc$Investigation of new trend in the field of microwave engineering $\bigcirc$Establishment of R＆D track for wireless and high speed communication III. Scope of investigation $\bigcirc$R＆D trend in various microwave engineering areas-Solid state Devices and circuits-Electromagnetic Field Theory-EMI＆EMC-Phased ＆ Active Array Antennas-Scattering ＆ Propagation $\bigcirc$Discussions with various technical topics-New research ＆ development topics-Establishment of wireless ＆ high speed communications IV. Results During the conference, very active academic exchange were possible between Korean and foreign microwave engineering scholars. It was also possible to introduce the level and activities of Korean microwave engineering researches to foreign countries. Also, it was good opportunity to contact foreign scholars and researchers for valuable academic discussion using technical paper presentations and inquiries.