• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.333-338
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• 2019

In the field of radiotherapy, the Quality Assurance(QA) procedure to verify the safety of treatment is considered to be very important. However, due to various problems of the conventional dosimeters used for the QA, researches on these dosimeters have been actively carried out to replace them. In this study, to maximize the sensitivity by visible light(VL) emitted from phosphors, blended hybrid sensors were fabricated by blending various weight percent(wt%) of $Gd_2O_2S:Tb$ which is a phosphor with excellent fluorescence efficiency into $PbI_2$. Then, the electrical properties to high energy radiation from the blended sensors and the pure $PbI_2$ sensor were compared and evaluated. As a result of the sensitivity evaluation, the sensor of 3wt% showed the highest value with more than 40% difference from the other sensors, and gradual decreasing in sensitivity was observed with increasing wt% except for the sensor of 3wt%. Also, in the reproducibility evaluation, the pure $PbI_2$ sensor exhibited a large variation in coefficient of variation(CV)>0.015, while all the blended sensors showed CV<0.015.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.533-536
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• 2019

Recombinant baculoviruses are widely used to express heterologous genes in cultured insect cells. Recombinant baculoviruses can serve as gene-transfer vectors for expression of recombinant proteins in a wide range of mammalian cell types. Baculovirus system has significant benefits in view of safety, large-scale, and high level of gene expression. In this study, baculoviral vectors which were reconstructed from pOPINEneo-3C-GFP vector, were recombined with cytomegalovirus (CMV) promoter, green fluorescent protein (GFP), and p53 with NcoI and XhoI. These recombinant vectors were infected with various cells and cell lines. The baculovirus vector thus developed was analyzed by comparing the metastasis and expression of the recombinant genes with conventional vectors. These results suggest that the baculovirus vector has higher efficiency in metastasis and expression than the control vector. This work was supported by a grant from Mid-Career Researcher Program(NRF-2016R1A2B4016552) through the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT & Future Planning(MSIP).

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.391-399
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• 2021

Eu²⁺ doped polyphosphate NaSr(PO₃)₃ blue-emitting phosphors were synthesized by the conventional solid state method in a reductive atmosphere. The phase formation of NaSr(PO₃)₃ phosphors were characterized by using the X-ray powder diffraction (XRD) measurement. The photoluminescence emission and excitation spectra of the NaSr(PO₃)₃:Eu²⁺ phosphor, and decay curves were measured. Under the near-UV excitation, the phosphor exhibits a band emission around 420 nm assigned to the 4f⁶5d→f7(8S^7/2) transition of Eu²⁺. The temperature dependent emission spectra and decay curves were measured to elevate the thermal properties of the Eu²⁺ doped phosphors. The as-prepared NaSr(PO₃)₃:Eu²⁺ phosphors show a strong temperature dependent performance, which can serve as a promising temperature sensor.

• Journal of fish pathology
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• v.34 no.1
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• pp.39-46
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• 2021

Tetracycline (TC) is one of the antibiotics used for treatment of bacterial infection in Korea. Inadequate usage and abuse cause the resistance to antibiotics, like Tetracycline, Erythromycin, and Fluoroquinolone. It can also affect severe economic loss in aquaculture field in Korea. We isolated 101 bacterial samples from diseased fish at aquaculture sites in Gyeonggi-do during 2015~2018. Minimum inhibitory concentration (MIC) method has been used to determine distribution and to identify bacterial isolates resistant to antibiotics including Oxytetracycline (OTC), Ampicillin (AMP), Clindamycin (CLI), Enrofloxacin (ENRO), Gentamycin (GEN). TC resistant isolates were confirmed antibiotic resistant genes by conventional PCR. Bacterial isolates were identified as Aeromonas spp. (43.5%), Pseudomonas spp. (4.0%) and Vibrio spp. (5.0%). It was confirmed that multi-resistant isolates (77.2%) were predominant over single-resistant one (22.8%). TC resistant genes like tet(A), tet(D), tet(E), tet(G), tet(M), and tet(S) were detected and tet(A) was the most prevalent. Aeromonas spp. is a dominant strain in bacterial infections in fishes of aquaculture sites, and further investigation on various antibiotic resistance genes will be needed for clear understanding of aquaculture sites in Gyeonggi-do.

• Journal of Gastric Cancer
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• v.21 no.1
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• pp.93-102
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• 2021

Purpose: With advances in surgical techniques, reduced-port laparoscopic surgery is increasingly being performed for the treatment of gastric carcinoma. Many studies have reported satisfactory short-term outcomes after reduced 3-port laparoscopic gastrectomy (LG). The aim of this study was to investigate the long-term oncological outcomes of 3-port LG in patients with gastric carcinoma. Materials and Methods: We reviewed the medical records of 1,117 patients who underwent LG for gastric carcinoma in three major institutions between 2012 and 2015. The data showed that 460 patients underwent 3-port LG without assistance, and 657 underwent conventional 5-port LG. We compared the overall and disease-free survival rates between the 2 groups. Results: There were 642 male and 475 female patients with a mean age of 56.1 years. Among them, 1,028 (92.0%) underwent distal gastrectomy and 89 (8.0%) underwent total gastrectomy. In the final pathologic examination, 1,027 patients (91.9%) were stage I, 73 (6.5%) were stage II, and 17 (1.5%) were stage III, and there were no significant difference in the pathologic stage between groups. The 3- and 5-port LG groups showed no significant differences in the 5-year overall survival (94.3% vs. 96.7%, P=0.138) or disease-free survival (94.3% vs. 95.9%, P=0.231). Stratified analyses according to pT and pN stages also showed no significant differences in overall or disease-free survival between the two groups. Conclusions: Long-term survival after 3- and 5-port LG was comparable in patients with early-stage gastric carcinoma. The 3-port technique requiring limited surgical assistance may be an appropriate surgical option for this patient population.

• Journal of Veterinary Science
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• v.24 no.3
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• pp.44.1-44.17
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• 2023

Background: Antibiotic resistance is a significant public health concern around the globe. Antimicrobial peptides exhibit broad-spectrum and efficient antibacterial activity with an added advantage of low drug resistance. The higher water content and 3D network structure of the hydrogels are beneficial for maintaining antimicrobial peptide activity and help to prevent degradation. The antimicrobial peptide released from hydrogels also hasten the local wound healing by promoting epithelial tissue regeneration and granulation tissue formation. Objective: This study aimed at developing sodium alginate based hydrogel loaded with a novel antimicrobial peptide Chol-37(F34-R) and to investigate the characteristics in vitro and in vivo as an alternative antibacterial wound dressing to treat infectious wounds. Methods: Hydrogels were developed and optimized by varying the concentrations of crosslinkers and subjected to various characterization tests like cross-sectional morphology, swelling index, percent water contents, water retention ratio, drug release and antibacterial activity in vitro, and Pseudomonas aeruginosa infected wound mice model in vivo. Results: The results indicated that the hydrogel C proved superior in terms of cross-sectional morphology having uniformly sized interconnected pores, a good swelling index, with the capacity to retain a higher quantity of water. Furthermore, the optimized hydrogel has been found to exert a significant antimicrobial activity against bacteria and was also found to prevent bacterial infiltration into the wound site due to forming an impermeable barrier between the wound bed and external environment. The optimized hydrogel was found to significantly hasten skin regeneration in animal models when compared to other treatments in addition to strong inhibitory effect on the release of pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-α). Conclusions: Our results suggest that sodium alginate -based hydrogels loaded with Chol-37(F34-R) hold the potential to be used as an alternative to conventional antibiotics in treating infectious skin wounds.

• Journal of Korean Neurosurgical Society
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• v.65 no.1
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• pp.64-73
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• 2022

Objective : To evaluate the surgical outcomes of partial pedicle subtraction osteotomy (PPSO) in patients with thoracolumbar fractures and compare the outcomes of PPSO for burst fractures with those for posttraumatic kyphosis (PTK). Methods : From June 2013 to May 2019, 20 consecutive adult patients underwent PPSO for thoracolumbar fractures at the levels of T10 to L2. Of these patients, 10 underwent surgery for acute fractures (burst fractures), and 10 for sequelae of thoracolumbar fractures (PTK). Outcomes of PPSO were evaluated and compared between the groups. Results : Twenty patients (each 10 patients of burst fractures and PTK) with a mean age of 64.7±11.1 years were included. The mean follow-up period was 21.8±11.0 months. The mean correction of the thoracolumbar angle was -34.9°±18.1° (from 37.8°±20.5°preoperatively to 2.8°±15.2° postoperatively). The mean angular correction at the PPSO site was -38.4°±13.6° (from 35.5°±13.6° preoperatively to -2.9°±14.1° postoperatively). The mean preoperative sagittal vertical axis was 93.5±6.7 cm, which was improved to 37.6±35.0 cm postoperatively. The mean preoperative kyphotic angle at the PPSO site was significant greater in patients with PTK (44.8°±7.2°) than in patients with burst fractures (26.2°±12.2°, p=0.00). However, the mean postoperative PPSO angle did not differ between the two groups (-5.9°±15.7° in patients with burst fractures and 0.2°±12.4° in those with PTK, p=0.28). The mean angular correction at the PPSO site was significantly greater in patients with PTK (-44.6°±10.7°) than in those with burst fractures (-32.1°±13.7°, p=0.04). The mean operation time was 188.1±37.6 minutes, and the mean amount of surgical bleeding was 1030.0±533.2 mL. There were seven cases of perioperative complications occurred in five patients (25%), including one case (5%) of neurological deficit. The operation time, surgical bleeding, and complication rates did not differ between groups. Conclusion : In cases of burst fracture, PPSO provided enough spinal cord decompression without corpectomy and produced sagittal correction superior to that achieved with corpectomy. In case of PTK, PPSO achieved satisfactory curve correction comparable to that achieved with conventional PSO, with less surgical time, less blood loss, and lower complication rates. PPSO could be a viable surgical option for both burst fractures and PTK.

• Journal of IKEEE
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• v.28 no.1
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• pp.97-103
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• 2024

Some drugs can offer far better medical effectiveness as it is injected through the intradermal layer of the skin, known as a needle-free injection. However, conventional needle-free devices might deliver a relatively large amount of drug in a just single spot of skin, splitting open the tissue layer structure, which might cause bruising and bleeding. By injecting the small volume with a fast repetition rate in a large surface area of skin, the patient may get much fewer injuries and pain. To achieve that specification, the driving force must be instantaneous and short-pulsed. Such a form of an injection device has been developed but the efficacy of those devices has been rarely examined. Therefore, this study developed the laser-induced microjet device that ejects microjet whose speed is ~310 m/s, during the 400~800 ㎲ of pulse time. The device can eject ~1 µL of the drug at the rate at which each shot repeated 10 shots per second. Using this specification, we evaluated the efficacy of drug injection onto mouse models. After injecting the insulin solution into the mouse model, the blood insulin level is detected, resulting in 20 % of blood insulin level with the ordinary needle syringe injection method.

• Journal of Life Science
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• v.22 no.6
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• pp.703-712
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• 2012

Adeno-associated virus (AAV) has been considered to be a very safe and efficient gene delivery system. However, the major obstacles to therapeutic usage of AAV have been to achieve highly efficient and reproducible production processes, and also to develop a reliable quantifying method of various serotypes with a simple protocol. We compared the efficiency of the conventional production protocol of AAV2 and adenovirus (Ad) co-infection to that of a new method containing AAV2 infection followed by pHelper transfection. We tested HEK293 and 293T, and further examined the time-dependent changes of AAV2 production. The new method of AAV2 and pHelper DNA gave about ten times higher production efficiency than that of the conventional protocol. The highest production efficiency in 293T was achieved as $1.61{\times}10^5$ virus genomes (v.g.)/cell by the new method of 10 MOI of AAV2 infection and 5 days post-infection. This protocol of the highest efficiency was then applied to produce various AAV serotypes and showed the efficiencies higher than $10^5$ v.g./cell. Next, we designed the universal PCR primers of highly conserved regions for various AAV serotypes to develop a simple and reliable titration method. The universal primers could amplify all the tested AAV serotypes with similar sensitivities by ten molecular copies. Therefore, this pair of universal primers can be further utilized to detect AAV contaminants in therapeutic adenoviral vectors.

• Journal of the Korean Arthroscopy Society
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• v.6 no.2
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• pp.195-199
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• 2002

This article is to report a new technique for reconstruction of the anteromedial and posterolateral bundles of anterior cruciate ligament by separate tensioning and fixation of the each bundle. Method : Tibial and femoral tunnels were made with conventional technique of anterior cruciate ligament reconstruction. Tibial tunnel was enlarged $5\~7$ mm in anterior-posterior direction to make oval it in cross section. When preparing the Achilles tendon allograft, bone plug portion was trimmed as the conventional technique. The tendinous portion was trimmed as two separate bundles by dividing the tendinous portion longitudinally, so the graft is shaped like 'Y'. The bone plug portion of allograft was inserted into the femoral tunnel and fixed with absorbable cross pins. Two ligamentous portionss of the distal part of the grafts were tensioned separately at the external orifice. Anteromedial bundle was fastened under maximum tension with the knee flexed 90 degrees by post-tie method. The posterolateral bundle was fixed by the same technique with the knee in full extension. Then, an absorbable interference screw was inserted between the two bundles upto the upper end of the tibial tunnel, to get more initial rigidity of the reconstructed graft as well as to locate the two bundles in more anatomic position.