• Current Optics and Photonics
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• v.7 no.6
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• pp.701-707
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• 2023

In laser imaging, accurate extraction of the laser's center is essential. Several methods exist to extract the laser's center in an image, such as the geometric mean, the parabolic curve fitting, and the Gaussian curve fitting, etc. The Gaussian curve fitting is the most suitable because it is based on the physical properties of the laser. The width of the Gaussian laser beam depends on the distance from the laser source to the target object. It is assumed in general that the distance remains constant at a laser spot resulting in a symmetric Gaussian model for the laser image. However, on a curved surface of the object, the distance is not constant; The laser beam is narrower on the side closer to the focal point of the laser light and wider on the side closer to the laser source, which causes the distribution of the laser beam to skew. This study presents a modified Gaussian model in the laser imaging to incorporate the slant angle of a curved object. The proposed method is verified with simulation and experiments.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.3
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• pp.225-236
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• 2012

In this study, the cellular protective effects on HaCaT cells and human erythrocytes and antioxidative effects of P. tricuspidata stem extracts were investigated. The ethyl acetate ($50{\mu}g/mL$) and aglycone fraction ($25{\mu}g/mL$) of P. tricuspidata stem extracts doesn't show any characteristics of cytotoxicity. When HaCaT cells were treated with 10 mM $H_2O_2$ and $30{\mu}M$ rose bengal, the ethyl acetate ($6.25{\sim}50{\mu}g/mL$) and aglycone ($6.25{\sim}25{\mu}g/mL$) fraction protected the cells against the oxidative damage in a concentration dependent manner. The P. tricuspidata stem extracts showed more prominent cellular protective effect than (+)-${\alpha}$-tocopherol, known as lipid antioxidant at $10{\mu}g/mL$. The ethylacetate fraction of P. tricuspidata stem extracts ($18.5{\mu}g/mL$) showed more free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activity ($FSC5_{50}$). Reactive oxygen species (ROS) scavenging activity ($OSC_{50}$) of P. tricuspidata stem extracts on ROS generated in $Fe^{3+}$-EDTA/$H_2O_2$ system was investigated using the luminol-dependent chemiluminescence assay. The ethyl acetate ($1.72{\mu}g/mL$) and the aglycone fraction ($1.53{\mu}g/mL$) showed similar ROS scavenging activity of L-ascorbic acid ($1.50{\mu}g/mL$). These results indicate that extract/fractions of P. tricuspidata stem extracts can function as natural cytoprotective agents and antioxidants in biological systems, particularly skin exposed to UV radiation by protecting cellular membrane against ROS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.6
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• pp.407-410
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• 2018

As the operating frequency of an electromagnetic wave increases, the maximum output and wavelength of the wave decreases, so that the size of the circuit cannot be reduced. As a result, the fabrication of a circuit with high power (of the order of or greater than kW range) and terahertz wave frequency band is limited, due to the problem of circuit size, to the order of ${\mu}m$ to mm. In order to overcome these limitations, we propose a source design technique for 0.1 THz~0.3 GW level with cylindrical shape (diameter ~2.4 cm). Modeling and computational simulations were performed to optimize the design of the high-power electromagnetic sources based on Cherenkov radiation generation technology using the principle of plasma wakefield acceleration with ponderomotive force and artificial dielectrics. An effective design guideline has been proposed to facilitate the fabrication of high-power terahertz wave vacuum devices of large diameter that are less restricted in circuit size through objective verification.

• Korean Journal of Food Science and Technology
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• v.40 no.2
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• pp.123-128
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• 2008

The MRLs (maximum residue limits) of DDT (DDD and DDE) in fresh ginseng, dried ginseng, and steamed red ginseng are set as low as 0.01 mg/kg, 0.05 mg/kg, and 0.05 mg/kg, respectively. Therefore, this study was undertaken to develop a simple and highly sensitive analysis method, as well as to reduce interfering ginseng matrix peaks, for the determination of DDT isomers (o,p'-DDE, p,p'-DDE, o,p'-DDD, p,p'-DDD, o,p'-DDT, and p,p'-DDT) in fresh ginseng, dried ginseng, and steamed red ginseng at the 0.01 mg/kg level. The method used acetonitrile extraction according to simultaneous analysis, followed by normal-phase Florisil solid-phase extraction column clean-up. The purification method entailed the following steps: (1) dissolve the concentrated sample extract in 7 mL hexane; (2) add 3 mL of $H_2SO_4$; (3) vigorously shake on avortex mixer; (4) cetrifuge at 2000 rpm for 5 min; (5) transfer 3.5 mL of the supernatant to the Florisil-SPE (500 mg/6 mL);and (6) elute the SPE column with 1.5 mL of hexane and 10 mL of ether/hexane (6:94). The determination of DDT isomers was carried out by a gas chromatography-electron capture detector (GC-${\mu}$ECD). The hexane and ether/hexane (6:94) eluate significantly removed chromatographic interferences, and the addition of 30% $H_2SO_4$ to the acetonitrile extract effectively reduced many interfering ginseng matrix peaks, to allow for the determination of the DDT isomers at the 0.01 mg/kg level. The recoveries of the 6 fortified (most at 0.01 mg/kg) DDT isomers from fresh ginseng, dried ginseng, and steamed red ginseng ranged from 87.9 to 99.6%. The MDLs (method detection limits) ranged from 0.003 to 0.009 mg/kg. Finally, the application of this method for the determination of DDT isomers is sensitive, rapid, simple, and inexpensive.

• Journal of Families and Better Life
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• v.32 no.6
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• pp.19-30
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• 2014

The purpose of this study was to identify the relationships between Healthy Family Support Center (HFSC) program participation and family strengths and program needs based on HFSC participants' individual, family, and community characteristics. A total of 695 HFSC participants who were married and had participated in HFSC programs were recruited through 25 local HFSCs in Seoul. A multiple regression method was conducted for data analysis. The major findings are as follows. Family strengths was related to the variables of age, education, monthly household income, and participation in family counseling and sharing family care programs. In terms of program needs, the variables of marital conflict, difficulty in care, financial distress, family strengths, and family-friendly community were associated with HFSC program needs while participants' socio-demographic characteristics were not related to program needs. This study highlights that HFSC programs have different target populations considering that the level of family strengths was different among the various programs' participants. In addition, program needs are different depending upon the HFSC participants' experiences in the family and community. These findings suggest that it is important to consider participants' family and community characteristics as well as participants' socio-demographic characteristics to provide appropriate programs for all HFSC participants.

• Journal of Chest Surgery
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• v.30 no.11
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• pp.1154-1158
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• 1997

Synovial sarcoma is an uncommon malignant mesenchymal tumor that occurs in the vicinity of the joints, bursae, and tendon sheaths. Typically the lesions are located in the extremities, especially in the lower extremities. They also occur in the abdominal and thoracic walls, but rarely in the head and neck. We experienced a case of synovial sarcoma of the rib in 17-year -old woman. We performed on bloc chest wall resection including the right second rib tumor, fi st and third ribs. The postoperative course was uneventful. She received chemotherapy because of a relapse of the tumor in sternum and both lung during follow-up.

• Journal of Pharmaceutical Investigation
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• v.16 no.3
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• pp.118-123
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• 1986

Time-concentration curves of recombinant human interferon alpha$(rIFN-{\alpha}A)$ in the skin and serum of nude mice or rats were studied after topical application of IFN ointment. IFN appeared in the skin and serum in less than 30 minutes and lasted for more than 10-12 hours at high concentration level after the application to nude mice at a dose of $9.0{\times}10^5\;IU/g$ mouse. But in the rats, IFN was not detected in the serum even 7 hours after the application at a dose of $6.0{\times}10^5\;IU/g$ rat. Topical application of IFN might be useful for the topical and systemic treatment if the human skin resembles that of nude mouse in respect to transport characteristics.

• IMMUNE NETWORK
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• v.21 no.6
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• pp.38.1-38.8
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• 2021

Recently, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (B.1.1.529) Omicron variant originated from South Africa in the middle of November 2021. SARS-CoV-2 is also called coronavirus disease 2019 (COVID-19) since SARS-CoV-2 is the causative agent of COVID-19. Several studies already suggested that the SARS-CoV-2 Omicron variant would be the fastest transmissible variant compared to the previous 10 SARS-CoV-2 variants of concern, interest, and alert. Few clinical studies reported the high transmissibility of the Omicron variant but there is insufficient time to perform actual experiments to prove it, since the spread is so fast. We analyzed the SARS-CoV-2 Omicron variant, which revealed a very high rate of mutation at amino acid residues that interact with angiostatin-converting enzyme 2. The mutation rate of COVID-19 is faster than what we prepared vaccine program, antibody therapy, lockdown, and quarantine against COVID-19 so far. Thus, it is necessary to find better strategies to overcome the current crisis of COVID-19 pandemic.

• Korean Journal of Radiology
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• v.21 no.11
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• pp.1210-1219
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• 2020

Objective: To compare the utility and diagnostic performance of automated breast ultrasound system (ABUS) with that of handheld ultrasound (HHUS) in evaluating pure non-mass enhancement (NME) lesions on breast magnetic resonance imaging (MRI). Materials and Methods: One hundred twenty-six consecutive MRI-visible pure NME lesions of 122 patients with breast cancer were assessed from April 2016 to March 2017. Two radiologists reviewed the preoperative breast MRI, ABUS, and HHUS images along with mammography (MG) findings. The NME correlation rate and diagnostic performance of ABUS were compared with that of HHUS, and the imaging features associated with ABUS visibility were analyzed. Results: Among 126 pure NME lesions, 100 (79.4%) were malignant and 26 (20.6%) were benign. The overall correlation rate was 87.3% (110/126) in ABUS and 92.9% (117/126) in HHUS. The sensitivity and specificity were 87% and 50% for ABUS and 92% and 42.3% for HHUS, respectively, with no significant differences (p = 0.180 and 0.727, respectively). Malignant NME was more frequently visualized than benign NME lesions on ABUS (93% vs. 65.4%, p = 0.001). Significant factors associated with the visibility of ABUS were the size of NME lesions on MRI (p < 0.001), their distribution pattern (p < 0.001), and microcalcifications on MG (p = 0.027). Conclusion: ABUS evaluation of pure NME lesions on MRI in patients with breast cancer is a useful technique with high visibility, especially in malignant lesions. The diagnostic performance of ABUS was comparable with that of conventional HHUS in evaluating NME lesions.

• Environmental Mutagens and Carcinogens
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• v.16 no.1
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• pp.6-12
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• 1996

To investigate the clastogenicity of taxol and its precursor, 10-aleacetyl baccatin III, we performed chromosomal aberration assay with chinese hamster lung cells in vitro. The IC$_{50}$ values of taxol and 10-deacetyl baccatin III were determined as $1/16 \times 10^{-4}$ M (5.34 $\mu$g/ml) and $1 \times 10^{-2}$ M (560 $\mu$g/ml) in MTT assay, respectively. It means that the cytotoxicity of taxol revealed 100 times more cytotoxic than 10-deacetyl baccatin III in chinese hamster lung cell line. Nevertheless the strong positive genetic toxicity of taxol in the bone marrow micronucleus assay in vivo which was recently reported, we observed weak positive clastogenicity of taxoi only in the absence of metabolic activation system in the concentration ranges used in this experiment. Moreover, to clarify the involvement of metabolic fate of taxol because of its strong positive result in vivo, 10-deacetyl baccatin III which is a precursor in taxol synthesis, also subjected in chromosomal aberration assay in vitro. However, we observed no clastogenicity of 10-deacetyl baccatin III in this experiment. From above results, it was suggested that the esterification at C-13 appears to be relative for its genetic toxicity in chromosome aberration using chinese hamster lung cell in vitro.