• 보존과학연구
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• s.28
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• pp.75-90
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• 2007

The ancient biomolecular remains are the potential source for paleobiology and paleoanthropology. Especially, ancient human specimens such as bone, teeth, and hair are powerful materials to identify historical origin and migration of ancestor population from the past. However, most excavated human specimens in archaeological sites have commonly problems as natural damage and exogenous contamination. We carried out histological and molecular analyses of excavated bone from the historic sites in South Korea from the recently discovered in tumulus of Seochun and Naju. Biological deterioration of bone was observed anatomically by optical and scanning electron microscope (SEM). We extracted degraded DNA, and amplified hyper variable region (HVR) of mitochondrial DNA (mtDNA) and amelogenin of nucleus DNA. This study applied and examined the relationships between histological preservation and DNA survival in excavated bone.

• The Korean Journal of Nuclear Medicine
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• v.21 no.2
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• pp.221-224
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• 1987

Uptake of $^{99m}Tc$ bone-scanning agents by extra osseous tissues has been frequently reported. However, lung and stomach uptake of $^{99m}Tc$ bone-scanning agents in lymphoma has been rarely described. We report here a case with lymphoma and hypercalcemia which showed diffuse uptake of $^{99m}Tc-MDP$ by lung and stomach.

• Journal of Veterinary Clinics
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• v.20 no.2
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• pp.229-232
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• 2003

Ultrasonographic examination of the stifle joint four clinically and radiographically normal adult dogs was performed before and after inducing the cranial cruciate ligament (CrCL) rupture of the bilateral stifle surgically. At Pre- or post-surgery, the hyperechoic patella ligament and the echogenic infrapatella fat interfered the visualization of the CrCL by the plain scanning method. However when the stifle joint was imaged by the scanning method injecting normal saline within the joint capsule, the hyperechogenic ligament was visualized by the separation of the infrapatella fat and the CrCL and the contrast effect of anechoic saline. When the stifle joint was imaged by the real time scanning method after the induction of the surgical rupture, fluttering of the ligament and anechoic area between the bone and the CrCL was identified due to the lack of tonicity and continuity of the ligament. Enlargement of the ligament because of its increased diameter as well as fluttering of the CrCL and the increased joint space's thickness was visualized. Consequently, confirming fluttering of the CrCL, increased ligament diameter and anechoic region between the CrCL and the bone, ultrasonographic examination is a valuable diagnostic tool as well as cranial drawer test and radiographic examination.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.1-7
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• 2016

In the dentistry field, an ultrasonic surgery unit is widely used in bone cutting and scaling to reduce operation time and minimize hemorrhage. The purpose of this study was to evaluate bone cutting and the effect of a specimen's temperature on the two-type ultrasonic surgery unit using a handpiece moving system(HMS). A HMS, which can cut the bone, was developed to perform the experimental procedure with precision of motion control. Bone specimens were prepared from a combination of epoxy-hardener and cortical bone of bovine leg. Through the bone-cutting experiment, the cutting depth was evaluated by not only scanning electron microscopy, but also Vernier calipers. Also, the temperature distribution was measured by a thermo-graphic camera. This study may be applied methodically in various experimental evaluations on a performance test by a HMS.

• The korean journal of orthodontics
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• v.46 no.6
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• pp.386-394
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• 2016

Objective: The objective of the study was to evaluate the practicality and the validity of different surface treatments of self-drilling orthodontic mini-implants (OMIs) by comparing bone cutting capacity and osseointegration. Methods: Self-drilling OMIs were surface-treated in three ways: Acid etched (Etched), resorbable blasting media (RBM), partially resorbabla balsting media (Hybrid). We compared the bone cutting capacity by measuring insertion depths into artificial bone (polyurethane foam). To compare osseointegration, OMIs were placed in the tibia of 25 rabbits and the removal torque value was measured at 1, 2, 4, and 8 weeks after placement. The specimens were analyzed by optical microscopy, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). Results: The bone cutting capacity of the etched and hybrid group was lower than the machined (control) group, and was most inhibited in the RBM group (p < 0.05). At 4 weeks, the removal torque in the machined group was significantly decreased (p < 0.05), but was increased in the etched group (p < 0.05). In the hybrid group, the removal torque significantly increased at 2 weeks, and was the highest among all measured values at 8 weeks (p < 0.05). The infiltration of bone-like tissue surface was evaluated by SEM, and calcium and phosphorus were detected via EDS only in the hybrid group. Conclusions: Partial RBM surface treatment (hybrid type in this study) produced the most stable self-drilling OMIs, without a corresponding reduction in bone cutting capacity.

• 대한핵의학회:학술대회논문집
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• 1977.05a
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• pp.99.1-99.1
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• 1977

• Advances in biomechanics and applications
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• v.1 no.1
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• pp.15-22
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• 2014

Computed tomography (CT) is being utilized in orthopaedics and related research to estimate bone strength. These applications benefit from calibration of Hounsfield units to mineral density typical of long bone, up to $1750mg/cm^3$. This study describes a method for establishing repeatable calibration of Hounsfield units to density, and determines the effects of imaging medium on calibration accuracy. Four hydroxyapatite standards were imaged in air on 7 occasions over 19 weeks using a helical multi-slice CT scanner. Each standard was scanned 5 times in different media: porcine soft tissue, water, and air. Calibrated densities were highly repeatable (CV<3.5%). No difference in density was observed between water and soft tissue conditions (p>0.08). This work provides a model for determining repeatable scanner-specific density calibration, demonstrates that the linear relationship between Hounsfield units and density extends to values typical of cortical bone, and supports the practice of imaging calibration standards in an environment similar to that of the target bone.

• Corrosion Science and Technology
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• v.7 no.3
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• pp.162-167
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• 2008

Degradable implants have been in use for bone surgery for decades. However, degradable metal implants are one of the new research areas of biomaterials science. Magnesium has good biocompatibility due to its low toxicity, and it is a corroding, i.e. dissolvable, metal. Furthermore, magnesium is needed in human body, and naturally found in bone tissue. There have been some published reports also asserting the potential bone cell activation or bone healing effect of high magnesium ion concentrations. The classic method for achieving intertransverse process fusion involves autogenous iliac crest bone graft. Several investigations have been performed to enhance this type of autograft fusion. However, there is no research which has been undertaken to investigate the efficiency of pure magnesium particles in posterolateral spinal fusion. In this study, corrosion behavior of magnesium metal at the bone interface, the possibility of new bone cell formation and the degree of effectiveness in producing intertransverse process lumbar fusion in a sheep model have been investigated. Cortical bone screws were machined from magnesium alloy AZ31 extruded rod and implanted to hip-bones of sheep via surgery. Three months after surgery, the bone segments carrying these screws were removed from the sacrificed animals. Samples were sectioned to reveal Mg/bone interfaces and investigated using optical microscope, SEM-EDS and radiography. Optical and SEM images showed that there was a significant amount of corrosion on the magnesium screw. The elemental mapping results indicate, due to the presence of calcium and phosphorus elements, that there exists new bone formation at the interface. Furthermore, sixteen sheep were subjected to intertransverse process spinal fusions with pedicle screw fixation at various locations along their spines. Each animal was treated with 5cc autograft bone at one fusion level and 1cc magnesium+5cc autograft bone at the other. Six months after surgery, bone formation was evaluated by gross inspection and palpation, and radiological, histological, scanning electron microscopic and x-ray diffraction analyses. It may be stated that the potential for using useful corrosion of magnesium alloys in medical applications is expected to be significant.

• Polymer(Korea)
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• v.27 no.3
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• pp.226-234
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• 2003

Ipriflavone (IP), a non-hormonal isoflavone derivative, has been shown to interfere with bone remodeling by inhibiting bone resorption and stimulating bone formation. IP consistently increased the amount of Ca incorporated into the cell layer by mesenchymal stem cells (MSCs). In this study, we developed the novel IP loaded poly(L-lactide-co-glycolide) (PLGA) scaffolds for the possibility of the application of the tissue engineered bone. IP/PLGA scaffo1ds were prepared by solvent casting/salt leaching method and were characterized by porosimeter, scanning electron microscopy, determination of residual salt amount, differential scanning calorimetry, and X-ray diffractometer, respectively. IP/PLGA scaffolds were implanted into the back of athymic nude mouse to observe the effect of IP on the osteoinduction compared with control PLGA scaffo1ds. Thin sections were cut from paraffin embedded tissues and histological sections were stained H&E, von Kossa, and immunohistochemical staining for Type I collagen and osteocalcin. It can be observed that the porosity was above 91.7% and the pore size was above 101 $\mu\textrm{m}$. Control scaffo1d and IP/PLGA scaffo1ds of 50% IP were implanted on the back of athymic nude mouse to observe the effect of IP on the induction of cells proliferation for 9 weeks. The evidence of calcification, osteoblast, and osteoid from the undifferentiated stem cells in the subcutaneous sites and other soft connective tissue sites having a preponderance of stem cells has been observed. From these results, it seems that IP plays an important role for bone induction in IP/PLCA scaffolds.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.3
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• pp.290-302
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• 1994

This study was aimed to clarify the histopathological changes in the experimental animal model subjcted to rigid fixation performed across the frontonasal sutrue in growing rabbits. Sixteen rabbits aged 6 weeks used. In experimental group(n=12), rigid fixation with miniplates and screws was performed across the frontonasal suture. Control group(n=4) was those with periosteal elevation only. Experimental animals were sacrificed on the 2nd, 4th, 8th, and 12th week after operation, and frontonasal suture area was excised for light microscopic and scanning electron microscopic examination. The results obtained were as follows : 1. In control groups, collagen fiber bundles ran in the midportion of bone sutrue and cambial layers were seen at bone surface. Sutural surfaces are beveled and external and internal bony projected portions were observed. 2. In experimental groups, distance of bone suture was decreased by new bone formation on the 2nd week, while increased by bone resorption at the miniplate applied area and bone formation in the adjacent bone on the 4th week. 3. In experimental groups, the original bone surface was almost resorbed and new bone formation was found on the 8th week. Regulary-run collagen fibers, smooth and dense bone surfaces were similar to the bone patterns of control groups on the 12th week. Above results suggest that bone formation is restricted where the miniplate is applied, while compensatory growth is appeared in the adjacent bont. It is considered that rigid fixation with miniplates and acrews results in a little disturbance of sutural growth of the craniofacial bone in infancy and children when applied for short duration.