• Biomolecules & Therapeutics
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• v.29 no.5
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• pp.551-561
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• 2021

Thyroid cancer is the most common endocrine malignancy. Patients with well-differentiated thyroid cancers, such as papillary and follicular cancers, have a favorable prognosis. However, poorly differentiated thyroid cancers, such as medullary, squamous and anaplastic advanced thyroid cancers, are very aggressive and insensitive to radioiodine treatment. Thus, novel therapies that attenuate metastasis are urgently needed. We found that both PDGFC and PDGFRA are predominantly expressed in thyroid cancers and that the survival rate is significantly lower in patients with high PDGFRA expression. This finding indicates the important role of PDGF/PDGFR signaling in thyroid cancer development. Next, we established a SW579 squamous thyroid cancer cell line with 95.6% PDGFRA gene insertion and deletions (indels) through CRISPR/Cas9. Protein and invasion analysis showed a dramatic loss in EMT marker expression and metastatic ability. Furthermore, xenograft tumors derived from PDGFRA geneedited SW579 cells exhibited a minor decrease in tumor growth. However, distant lung metastasis was completely abolished upon PDGFRA gene editing, implying that PDGFRA could be an effective target to inhibit distant metastasis in advanced thyroid cancers. To translate this finding to the clinic, we used the most relevant multikinase inhibitor, imatinib, to inhibit PDGFRA signaling. The results showed that imatinib significantly suppressed cell growth, induced cell cycle arrest and cell death in SW579 cells. Our developed noninvasive apoptosis detection sensor (NIADS) indicated that imatinib induced cell apoptosis through caspase-3 activation. In conclusion, we believe that developing a specific and selective targeted therapy for PDGFRA would effectively suppress PDGFRA-mediated cancer aggressiveness in advanced thyroid cancers.

• Journal of Biomedical Engineering Research
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• v.43 no.1
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• pp.11-18
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• 2022

An electromagnetic generator with variable stimulation parameters is required to conduct basic research on magnetic flux density and frequency for pulsed electromagnetic fields (PEMFs). In this study, we design an electromagnetic generator that can conduct basic research by providing parameters optimized for cell and animal experimental conditions through adjustable stimulation parameters. The magnetic core was selected as a solenoid capable of uniform and stable electromagnetic stimulation. The solenoid was designed in consideration of the experimental mouse and cell culture dish insertion. A voltage and current adjustable power supply for variable magnetic flux density was designed. The system was designed to be adjustable in frequency and pulse width and to enable 3-channel output. The reliability of the system and solenoid was evaluated through magnetic flux density, frequency, and pulse width measurements. The measured magnetic flux density was expressed as an image and qualitatively observed. Based on the acquired image, the stimulation area according to the magnetic flux density decrease rate was extracted. The PEMF frequency and pulse width error rates were presented as mean ± SD, and were confirmed to be 0.0928 ± 0.0934% and 0.529 ± 0.527%, respectively. The magnetic flux density decreased as the distance from the center of the solenoid increased, and decreased sharply from 60 mm or more. The length of the magnetic stimulation area according to the degree of magnetic flux density decrease was obtained through the magnetic flux density image. A PEMF generator and stimulation parameter control system suitable for cell and animal models were designed, and system reliability was evaluated.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.273-279
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• 2022

In order to reduce the absorbed dose given to the patient during dental radiography, a sensor that inserts a shield into the intraoralsensor was designed. Using the designed sensor, the change in absorbed dose depending on whether or not a shield was used was evaluated. The system used to evaluate the absorbed dose is VEX-S300C from Vatech, and the energy spectrum of X-rays was obtained through SPEKTR simulation based on the irradiation conditions of 65 kV, 3 mA, and 0.15 sec, and the number of photons for each energy was derived. After designing the system through Genat4 Application for Tomographic Emission(GATE) simulation, the energy spectrum obtained was used as a radiation source to calculate the absorbed dose. Lead was used for the shield, and simulations were performed at 0.1 mm thickness intervals from 0.1 mm to 0.5 mm was evaluated. In the case of using an X-ray field with a diameter of 60 mm, the decrease in absorbed dose according to the presence or absence of a shield decreased exponentially as the thickness of the shield increased. In addition, when a 20 mm × 30 mm field was used, the absorbed dose was significantly reduced even when no shield was used, and it was confirmed that the absorbed dose was further reduced when a shield was used.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.6
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• pp.589-604
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• 2021

Waterjets for rocks have various advantages of the non-contact and eco-friendly excavation using only water and abrasive. To overcome the problems (e.g., dust and noise occurrence) of the conventional drilling methods, waterjet excavation methods are broadly used. It is advantageous to operate a couple of nozzles in order to increase the waterjet excavation efficiency. When multiple nozzles are used, it is essential to analyze the excavation performance and shape according to the nozzle operation method. In this study, nozzle angle, horizontal distance between nozzles, and standoff distance were defined as nozzle operating parameters and the excavation performance and shape were analyzed. As a result of the experiment, when the nozzle angle and standoff distance are increased, the excavation depth is decreased and the effective depth tends to be increased. In addition, based on the experimental results, the excavation shape criteria required for nozzle insertion were proposed and optimal nozzle operating parameters were derived according to the criteria. This study result is expected to be used as useful basic research in the future development of multiple waterjet nozzles for rock drilling.

• Journal of the Society of Disaster Information
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• v.18 no.3
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• pp.542-549
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• 2022

Purpose: Pipes are widely used as applied devices in many industrial fields such as machinery, electronics, electricity, and plants, and are also widely used in safety-related fields such as firefighting and chemistry. With the diversification of products, the importance of technology in the piping field is also increasing. In particular, when changing the existing copper pipe to stainless steel, it is necessary to evaluate safety and flow characteristics through structural analysis or flow analysis. Method: This study investigated the structural stability of the 6.35 and 15.88 socket models, which are integrated insert type connectors developed by a company, using FEM. For structural analysis, HyperMesh as pre-processor, HYPER VIEW as post-processor, and LS-DYNA as solver were used. Result: In the case of 6.35 socket, the maximum stresses at hook, holder and hinge were 95.02MPa, 19.59MPa and 44.01MPa, respectively, and in case of 15.88 socket, it was 127.7 MPa, 40.09MPa and 45.23MPa, respectively. Conclusion: Comparing the stress distribution of the two socket models, the stress in the 15.88 socket, which has a relatively large outer diameter, appears to be large overall, but it is significantly lower than the yield stress of each material, indicating that there is no problem in structural safety in both models.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.313-319
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• 2022

Complete dentures are one of the most basic treatment methods for the treatment of edentulous patients. The manufacturing process of traditional complete dentures goes through the steps of taking primary impressions, secondary impressions, jaw relation record, trying in wax denture, and final denture insertion. Multiple visits and complex manufacturing procedures are required, and errors may occur in each step. With the development of digital technology, manufacturing steps have been reduced by introducing digital technology to the denture treatment process. In the process of manufacturing dentures by introducing a digital process, a more precise work is possible using Computer-Aided Design, and it is possible to shorten the period of labor and reduce the number of visits. In this case, the anterior teeth arrangement of the patient's existing dentures was transferred to the final dentures using a digital method. After taking impression, try-in dentures were digitally fabricated and tried in the oral cavity to evaluate their retention in the oral cavity. Final dentures were manufactured by milling process. The number of visits was reduced, satisfactory retention and stability of dentures were obtained, and aesthetic recovery was achieved.

• Journal of Chest Surgery
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• v.55 no.6
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• pp.435-441
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• 2022

Background: This study aimed to evaluate the impact of the treatment modality on post-procedural acute kidney injury (AKI) and other clinical outcomes in patients with advanced chronic kidney disease who underwent surgical or transcatheter aortic valve replacement (AVR). Methods: A total of 147 patients with advanced chronic kidney disease (stage 3 to 5) who underwent isolated surgical AVR (SAVR group; n=70) or transcatheter AVR (TAVR group; n=77) were retrospectively studied. Postprocedural AKI was defined according to the RIFLE definition (an acronym corresponding to the risk of renal dysfunction, injury to the kidney, failure of kidney function, loss of kidney function, and end-stage kidney disease). Factors associated with postoperative complications and mortality were analyzed using multivariable logistic regression models and Cox proportional hazard models. Results: Postprocedural AKI occurred in 17 (24.3%) and 6 (7.8%) patients in the SAVR and TAVR groups, respectively (p=0.006). Multivariable analyses demonstrated that the SAVR group had higher risks of AKI (odds ratio [OR], 5.63; 95% confidence interval [CI], 1.85-17.73; p=0.002) and atrial fibrillation (OR, 16.65; 95% CI, 4.44-62.50; p<0.001), whereas the TAVR group had a higher risk of permanent pacemaker insertion (OR, 5.67; 95% CI, 1.21-26.55; p=0.028). The Cox proportional hazard models showed that the occurrence of AKI, contrary to the treatment modality, was associated with overall survival. Conclusion: In patients with chronic kidney disease, the risk of postprocedural AKI might be higher after SAVR than after TAVR.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.6
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• pp.463-470
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• 2022

Intravenous injection is widely used for patient treatment, including injection drugs, fluids, parenteral nutrition, and blood products, and is the most frequently performed invasive treatment for inpatients, including blood collection, peripheral catheter insertion, and other IV therapy, and more than 1 billion cases per year. Intravenous injection is one of the difficult procedures performed only by experienced nurses who have been trained in intravenous injection, and failure can lead to thrombosis and hematoma or nerve damage to the vein. Nurses who frequently perform intravenous injections may also make mistakes because it is not easy to detect veins due to factors such as obesity, skin color, and age. Accordingly, studies on auxiliary equipment capable of visualizing the venous structure of the back of the hand or arm have been published to reduce mistakes during intravenous injection. This paper is about the development of venous detection equipment that visualizes venous structure during intravenous injection, and the optimal combination was selected by comparing the brightness of acquired images according to the combination of near-infrared (NIR) LED and Filter with different wavelength bands. In addition, an image processing algorithm was derived to threshehold and making blood vessel part to green through grayscale conversion, histogram equilzation, and sharpening filters for clarity of vein images obtained through the implemented venous detection experimental module.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.6
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• pp.485-491
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• 2022

Intravenous injection is the most frequent invasive treatment for inpatients and is widely used for parenteral nutrition administration and blood products, and more than 1 billion procedures are used for peripheral catheter insertion, blood collection, and other IV therapy per year. Intravenous injection is one of the difficult procedures to be performed only by trained nurses with intravenous injection training, and failure can lead to thrombosis and hematoma or nerve damage to the vein. Accordingly, studies on auxiliary equipment capable of visualizing the vein structure of the back of the hand or arm are being published to reduce errors during intravenous injection. This study is a study on the performance difference according to the number of LEDs irradiating the 850nm wavelength band on a vein detector that visualizes the vein during intravenous injection. Four LED PCBs were produced by attaching NIR filters to CCD and CMOS camera lenses irradiated on the skin to acquire images, sharpen the acquired images using image processing algorithms, and project the sharpened images onto the skin. After that, each PCB was attached to the front end of the vein detector to detect the vein image and create a performance comparison questionnaire based on the vein image obtained for performance evaluation. The survey was conducted on 20 nurses working at K Hospital.

• Journal of Mushroom
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• v.20 no.3
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• pp.178-182
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• 2022

Despite the long history of mushroom use, studies examining the genetic function of mushrooms and the development of new varieties via bio-molecular methods are significantly lacking compared to those examining other organisms. However, owing to recent developments, attempts have been made to use a novel gene-editing technique involving CRISPR/Cas9 technology and genetic scissors in mushroom studies. In particular, research is actively being conducted to utilize ribonucleoprotein particles (RNPs) that can be genetically edited with high efficiency without foreign gene insertion for ease of selection. However, RNPs are too large for Cas9 protein to pass through the cell membrane of the protoplasmic reticulum. Furthermore, guide RNA is unstable and can be easily decomposed, which remarkably affects gene editing efficiency. In this study, nanoparticles were used to mitigate the shortcomings of RNP-based gene editing techniques and to obtain transformants stably. We used Lentinula edodes (shiitake mushroom) Sanjo705-13 monokaryon strain, which has been successfully used in previous genome editing experiments. To identify a suitable osmotic buffer for the isolation of protoplast, 0.6 M and 1.2 M sucrose, mannitol, sorbitol, and KCl were treated, respectively. In addition, with various nanoparticle-forming materials, experiments were conducted to confirm genome editing efficiency via the formation of nanoparticles with calcium phosphate (CaP), which can be bound to Cas9 protein without any additional amino acid modification. RNPs/NP complex was successfully formed and protected nuclease activity with nucleotide sequence specificity.