• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.469-483
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• 2012

The propagation characteristics of a mechanical wave in human soft tissue depend on its elastic properties. Investigation of these propagation characteristics is of paramount importance because it may enable us to diagnose cancer or tumor from the vibration response of the tissue. This paper investigates and compares displacement patterns generated in soft tissue due to several forms of low-frequency vibration sources placed on a surface. Among vibration sources considered are a normal load, tangential load, and antiplane shear load. We derive analytical expressions for displacements in viscoelastic single layers, and calculate displacement patterns in half space and infinite plate type tissue. Also, we simulate the vibration response of a finite-sized tissue using finite element method. The effects of the type of stress, the size and frequency of vibration sources, and medium boundaries on displacement patterns are discussed.

• Clinics in Orthopedic Surgery
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• v.10 no.4
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• pp.455-461
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• 2018

Background: Surgical-site, multimodal drug injection has recently evolved to be a safe and useful method for multimodal pain management even in patients with musculoskeletal trauma. Methods: Fifty consecutive patients who underwent plating for mid-shaft and distal clavicular fractures were included in the study. To evaluate whether surgical-site injections (SIs) have pain management benefits, the patients were divided into two groups (SI and no-SI groups). The injection was administered between the deep and superficial tissues prior to wound closure. The mixture of anesthetics consisted of epinephrine hydrochloride (HCL), morphine sulfate, ropivacaine HCL, and normal saline. The visual analogue scale (VAS) pain scores were measured at 6-hour intervals until postoperative hour (POH) 72; stress biomarkers (dehydroepiandrosterone sulfate [DHEA-S], insulin, and fibrinogen) were measured preoperatively and at POH 24, 48, and 72. In patients who wanted further pain control or had a VAS pain score of 7 points until POH 72, 75 mg of intravenous tramadol was administered, and the intravenous tramadol requirements were also recorded. Other medications were not used for pain management. Results: The SI group showed significantly lower VAS pain scores until POH 24, except for POH 18. Tramadol requirement was significantly lower in the SI group until POH 24, except for POH 12 and 18. The mean DHEA-S level significantly decreased in the no-SI group ($74.2{\pm}47.0{\mu}g/dL$) at POH 72 compared to that in the SI group ($110.1{\pm}87.1{\mu}g/dL$; p = 0.046). There was no significant difference in the insulin and fibrinogen levels between the groups. The correlation values between all the biomarkers and VAS pain scores were not significantly different between the two groups (p > 0.05). Conclusions: After internal fixation of the clavicular fracture, the surgical-site, multimodal drug injection effectively relieved pain on the day of the surgery without any complications. Therefore, we believe that SI is a safe and effective method for pain management after internal fixation of a clavicular fracture.

• Hip & pelvis
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• v.30 no.4
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• pp.269-275
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• 2018

Purpose: The purpose of this study is to describe a method of inserting cement in the femoral head before fixation with dynamic hip screw to prevent screw cut out due to osteoporosis and to evaluate its clinical outcome in these patients. Materials and Methods: In this prospective study, 30 patients aged 60 years and older with intertrochanteric fracture were included. Bone mineral density was measured. After reaming of the femoral head and neck with a triple reamer and polymethyl methacrylate, bone cement was introduced into the femoral head using a customized nozzle and a barrel fitted on a cement gun. A Richard screw was inserted and the plate was fixed over the femoral shaft. Patients were mobilized and clinical outcomes were rated using the Salvati and Wilson's scoring system. Results: More patients included in this study were between 66 and 70 years old than any other age group. The most common fracture according to the Orthopaedic Trauma Association classification was type 31A2.2 (46.7%). The T-score was found to be $-2.506{\pm}0.22$ (mean${\pm}$standard deviation); all patients were within the range of -2.0 to -2.8. The duration of radiological union was $13.67{\pm}1.77$ weeks. Salvati and Wilson's scoring at 12 months of follow up was $30.96{\pm}4.97$. The majority of patients were able to perform their normal routine activities; none experienced implant failure or screw cut out. Conclusion: Bone cement augmentation may effectively prevent osteoporosis-related hardware complications like screw cut out in elderly patients experiencing intertrochanteric fractures.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.352-358
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• 2021

Molar-incisor malformation (MIM) is characterized by malformation in the root with a normal crown. While MIM mostly occurs in the permanent first molar, it has also been reported in the maxillary central incisor and the primary second molar (PSM), but anatomical analysis of the primary teeth with MIM has not been studied to date. In this case report, a patient with MIM was reported, and an extracted PSM with MIM was analyzed with micro computed tomography (CT). A cervical constriction morphology of the cementoenamel junction (CEJ) can be observed in extracted PSM. In micro CT analysis, characteristics such a mineralized plate (cervical mineralized diaphragm) in the CEJ area, complex root canal morphologies, a calcified mass inside the pulp chamber, and constricted pulp chamber of crown portion were observed.

• Journal of Microbiology and Biotechnology
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• v.31 no.2
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• pp.327-337
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• 2021

Fibrinolytic enzymes with a direct mechanism of action and safer properties are currently requested for thrombolytic therapy. This paper reports on a new enzyme capable of degrading blood clots directly without impairing blood coagulation. This enzyme is also non-cytotoxic and constitutes an alternative to other thrombolytic enzymes known to cause undesired side effects. Twenty-four Bacillus isolates were screened for production of fibrinolytic enzymes using a fibrin agar plate. Based on produced activity, isolate S127e was selected and identified as B. subtilis using the 16S rDNA gene sequence. This strain is of biotechnological interest for producing high fibrinolytic yield and consequently has potential in the industrial field. The purified fibrinolytic enzyme has a molecular mass of 27.3 kDa, a predicted pI of 6.6, and a maximal affinity for Ala-Ala-Pro-Phe. This enzyme was almost completely inhibited by chymostatin with optimal activity at 48℃ and pH 7. Specific subtilisin features were found in the gene sequence, indicating that this enzyme belongs to the BPN group of the S8 subtilisin family and was assigned as AprE127. This subtilisin increased thromboplastin time by 3.7% (37.6 to 39 s) and prothrombin time by 3.2% (12.6 to 13 s), both within normal ranges. In a whole blood euglobulin assay, this enzyme did not impair coagulation but reduced lysis time significantly. Moreover, in an in vitro assay, AprE127 completely dissolved a thrombus of about 1 cc within 50 min and, in vivo, reduced a thrombus prompted in a rat tail by 11.4% in 24 h compared to non-treated animals.

• Smart Structures and Systems
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• v.28 no.6
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• pp.745-760
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• 2021

Dynamic buckling of structure is one of the failure modes that needs to be considered since it may result in catastrophic failure of the structure in a short period of time. For a thin fiber-reinforced polymer (FRP) plate under compression, buckling is an inherent hazard which will be intensified by the existence of defects like holes, cracks, and delamination. On the other hand, the growth of the delamination is another prime concern for thin FRP plates. In the current paper, reinforcing the plates against buckling is realized by using SMA wires in the form of stitches. A numerical framework is proposed to simulate the dynamic instability emphasizing the effect of the SMA stitches in suppressing delamination growth. The suggested algorithm is more accurate than the other methods when considering the transformation point of the SMA wires and the modeling of the cohesive zone using simple and yet reliable technique. The computational design of the method by producing the line by line orders leads to a simple algorithm for simulating the super-elastic behavior. The Lagoudas constitutive model of the SMA material is implemented in the form of user material subroutines (VUMAT). The normal bilinear spring model is used to reproduce the cohesive zone behavior. The nonlinear finite element formulation is programmed into FORTRAN using the Newmark-beta numerical time-integration approach. The obtained results are compared with the results obtained by the finite element method using ABAQUS/Explicit solver. The obtained results by the proposed algorithm and those by ABAQUS are in good agreement.

• Journal of Microbiology and Biotechnology
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• v.33 no.4
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• pp.543-551
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• 2023

In this study, five endophytic fungi belonging to the Aspergillus and Alternaria genera were isolated from Lagopsis supina. The antimicrobial activity of all fungal fermented extracts against Staphylococcus and Fusarium graminearum was tested using the cup-plate method. Among them, Aspergillus ochraceus XZC-1 showed the best activity and was subsequently selected for large-scale fermentation and bioactivity-directed separation of the secondary metabolites. Four compounds, including 2-methoxy-6-methyl-1,4-benzoquinone (1), 3,5-dihydroxytoluene (2), oleic acid (3), and penicillic acid (4) were discovered. Here, compounds 1 and 4 displayed anti-fungal activity against F. graminearum, F. oxysporum, F. moniliforme, F. stratum, Botrytis cinerea, Magnaporthe oryzae, and Verticillium dahlia with diverse MIC values (128-512 ㎍/ml), which were close to that of the positive control antifungal, actidione (64-128 ㎍/ml). Additionally, compounds 1 and 4 also exhibited moderate antibacterial activity against S. aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica, with low MIC values (8-64 ㎍/ml). Moreover, compounds 1 and 4 displayed selective cytotoxicity against cancer cell lines as compared with the normal fibroblast cells. Therefore, this study proposes that the endophytic fungi from L. supina can potentially produce bioactive molecules to be used as lead compounds in drugs or agricultural antibiotics.

• Journal of Veterinary Science
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• v.25 no.4
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• pp.49.1-49.15
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• 2024

Importance: Endochondral ossification plays an important role in skeletal development. Recent studies have suggested a link between increased intracellular reactive oxygen species (ROS) and skeletal disorders. Moreover, previous studies have revealed that increasing the levels of myeloperoxidase (MPO) and osteopontin (OPN) while inhibiting NADPH oxidase 4 (NOX4) can enhance bone growth. This investigation provides further evidence by showing a direct link between NOX4 and MPO, OPN in bone function. Objective: This study investigates NOX4, an enzyme producing hydrogen peroxide, in endochondral ossification and bone remodeling. NOX4's role in osteoblast formation and osteogenic signaling pathways is explored. Methods: Using NOX4-deficient (NOX4^-/-) and ovariectomized (OVX) mice, we identify NOX4's potential mediators in bone maturation. Results: NOX4^-/- mice displayed significant differences in bone mass and structure. Compared to the normal Control and OVX groups. Hematoxylin and eosin staining showed NOX4^-/- mice had the highest trabecular bone volume, while OVX had the lowest. Proteomic analysis revealed significantly elevated MPO and OPN levels in bone marrow-derived cells in NOX4^-/- mice. Immunohistochemistry confirmed increased MPO, OPN, and collagen II (COLII) near the epiphyseal plate. Collagen and chondrogenesis analysis supported enhanced bone development in NOX4^-/- mice. Conclusions and Relevance: Our results emphasize NOX4's significance in bone morphology, mesenchymal stem cell proteomics, immunohistochemistry, collagen levels, and chondrogenesis. NOX4 deficiency enhances bone development and endochondral ossification, potentially through increased MPO, OPN, and COLII expression. These findings suggest therapeutic implications for skeletal disorders.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.2
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• pp.162-168
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• 2006

Purpose: Microbial colonization of the intestine begins just after birth and development of the normal flora is a gradual process. The first bacteria colonizing the intestine in newborns are Staphylococcus, Enterobacteriaceae and Streptococcus. For several days after birth, the number of Bifidobacterium spp. increase. The aim of this study was to investigate the changes of microflora for seven days postnatally in neonatal stool. Methods: Fifteen neonates (breast : formula : mixed feeding 1 : 8 : 6, vaginal delivery : cesarean section 3 : 12) who were born at the Kangdong Sacred Heart Hospital, Hallym University were enrolled. First meconium and stools of postnatal 1-, 3-, and 7-day were innoculated. Blood agar plates for total aerobes, trypton bile X-glucuronide agar for E. coli, phenylethyl alcohol agar for gram positive anaerobes, MRS agar for Lactobacillus spp., bifidobacterium selective agar for Bifidobacterium spp. and cefoxitin-cycloserine-fructose agar for Clostridium difficile were used in the general incubator ($CO_2$ free incubator), $CO_2$ incubator or the anaerobic chamber for 48 or 72 hours at $37^{\circ}C$ and then colony forming units were counted. Results: No microflora was identified in the first meconium. Total aerobes, E. coli, and gram positive anaerobes were significantly increased with advancing postnatal days. In only one baby, Lactobacillus acidophilus was detected $2{\times}10^5CFU/g$ in the seven-day stool. Bifidobacterium spp. was detected in two babies. Clostridium difficile was not detected during the seven days. There were no significant differences in the bowel flora depending on the delivery pattern and feeding method. Conclusion: This study shows many changes in the intestinal normal flora in neonatal stool during seven days postnatally. If these findings are confirmed with larger studies, the data may be preliminary findings to support use of probiotics in neonates.

• Radiation Oncology Journal
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• v.22 no.3
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• pp.165-176
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• 2004

Purpose: Firstly, to analyze facto in terms of radiation treatment that might potentially cause subfrontal relapse in two patients who had been treated by craniospinal irradiation (CSI) for medulloblastoma, Secondly, to explore an effective salvage treatment for these relapses. Materials and Methods: Two patients who had high-risk disease (T3bMl, T3bM3) were treated with combined chemoradiotherapy CT-simulation based radiation-treatment planning (RTP) was peformed. One patient who experienced relapse at 16 months after CSI was treated with salvage surgery followed by a 30.6 Gy IMRT (intensity modulated radiotherapy). The other patient whose tumor relapsed at 12 months after CSI was treated by surgery alone for the recurrence. To investigate factors that might potentially cause subfrontal relapse, we evaluated thoroughly the charts and treatment planning process including portal films, and tried to find out a method to give help for placing blocks appropriately between subfrotal-cribrifrom plate region and both eyes. To salvage subfrontal relapse in a patient, re-irradiation was planned after subtotal tumor removal. We have decided to treat this patient with IMRT because of the proximity of critical normal tissues and large burden of re-irradiation. With seven beam directions, the prescribed mean dose to PTV was 30.6 Gy (1.8 Gy fraction) and the doses to the optic nerves and eyes were limited to 25 Gy and 10 Gy, respectively. Results: Review of radiotherapy Portals clearly indicated that the subfrontal-cribriform plate region was excluded from the therapy beam by eye blocks in both cases, resulting in cold spot within the target volume, When the whole brain was rendered in 3-D after organ drawing in each slice, it was easier to judge appropriateness of the blocks in port film. IMRT planning showed excellent dose distributions (Mean doses to PTV, right and left optic nerves, right and left eyes: 31.1 Gy, 14.7 Gy, 13.9 Gy, 6.9 Gy, and 5.5 Gy, respectively. Maximum dose to PTV: 36 Gy). The patient who received IMRT is still alive with no evidence of recurrence and any neurologic complications for 1 year. Conclusion: To prevent recurrence of medulloblastoma in subfrontal-cribriform plate region, we need to pay close attention to the placement of eye blocks during the treatment. Once subfrontal recurrence has happened, IMRT may be a good choice for re-irradiation as a salvage treatment to maximize the differences of dose distributions between the normal tissues and target volume.