• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.4
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• pp.319-324
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• 2011

This paper dealt with a partial discharge (PD) detection method for insulation diagnosis in cast-resin transformers. To detect PD pulse, a planar-capacitive probe was designed and fabricated. The probe has no insulation problem and can be installed on cast-resin transformers even in operation since it does not connect with high voltage conductor. The PD measurement system consists of the capacitive probe, a coupling network of 100 [kHz] low-cutoff frequency, and an amplifier with a gain of 40 [dB] and a frequency bandwidth of 500 [Hz]~45 [MHz]. A plane-needle and a plane-plane electrode system were fabricated to simulate insulation defects in a cast-resin transformer. Sensitivity of the PD measurement system, which is evaluated by a standard calibrator was 0.35 [mV/pC] for positive and 0.45 [mV/pC] for negative, respectively. The PD detection by the capacitive probe was less sensitive than that by a coupling capacitor according to IEC 60270, but we could analyze the magnitude and the phase distribution of PD pulse.

• Journal of the Korean Society of Radiology
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• v.81 no.1
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• pp.147-156
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• 2020

Purpose The objective of this study was to evaluate the diagnostic value and threshold levels of cytokeratin fragment 21-1 (CYFRA 21-1) in fine-needle aspiration (FNA) washouts for detection of lymph node (LN) recurrence in postoperative breast cancer patients. Materials and Methods FNA cytological assessments and CYFRA 21-1 measurement in FNA washouts were performed for 64 axillary LNs suspicious for recurrence in 64 post-operative breast cancer patients. Final diagnosis was made on the basis of FNA cytology and follow-up data over at least 2 years. The concentration of CYFRA 21-1 was compared between recurrent LNs and benign LNs. Diagnostic performance and cut-off value were evaluated using a receiver operating characteristic curve. Results Regardless of the non-diagnostic results, the median concentration of CYFRA 21-1 in recurrent LNs was significantly higher than that in benign LNs (p < 0.001). The optimal diagnostic cut-off value was 1.6 ng/mL. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of CYFRA 21-1 for LN recurrence were 90.9%, 100%, 100%, 98.1%, and 98.4%, respectively. Conclusion Measurement of CYFRA 21-1 concentration from ultrasound-guided FNA biopsy aspirates showed excellent diagnostic performance with a cut-off value of 1.6 ng/mL. These results indicate that measurement of CYFRA 21-1 concentration in FNA washouts is useful for the diagnosis of axillary LN recurrence in post-operative breast cancer patients.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.7 no.2
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• pp.208-221
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• 2000

The objective of this research was to compare the flushing effects using 1:1,000 diluted heparin or 0.9% normal saline in relation to needle gauge and frequency of IV medications. The comparative categories were clotting, duration of patency, and incidence of phlebitis. The design of research was a Nonequivalent Control group, Post test, Nonsynchrorized Design. The independent variable was 0.9% normal saline flushing the IV locks and the dependent variables were clotting, duration of patency, and incidence of phlebitis. Subjects were medical-surgical inpatients over 15 years old and with peripherally placed IVs who were hospitalized in a university medical center. Exclusion criteria included foreigners and those who were rejected for this research. The final sample for data analysis included 295 IV sites in 194 patients; 154 were in the saline group and 141 were in the heparin group. Subjects were assigned to have IV locks is flushed with 0.9% normal saline in the experimental group and to have IV lock flushed with 1:1,000 diluted heparin(100 units) in the control group. In order to increase reliability, the nurses who were assigned to the units involved in the study received an explanation on the standard method for locking an IV, recording method for observational data and criteria for the detection of phlebitis. Data were collected for a period of 2 weeks, from March 16, 2000 to March 29, 2000. Total duration of IV was defined the time of IV insertion to the time of discontinuation. Phlebitis was defined as the presence of the following : pain, swelling. erythema at the insertion site. Chi-square was used to determine the association between the degree of clotting, duration of patency, and incidence of phlebitis for the diluted heparin or the normal saline and needle gauge and frequency of IV medications. The results are summarized as follows : (a) There was difference in the degree of clotting between two groups($X^2=5.882$, p=.015). (b) There was no difference in the degree of duration of patency between two groups($X^2=2.439$, p=.295). (c) There was no difference in the incidence of phlebitis between two groups($X^2=0.190$, p=.663). (d) There was difference in the degree of clotting($X^2=6.209$, p=.013) and in the degree of duration of patency($X^2=6.978$, p=.031) according the needle guage between the two groups. (e) There was difference in the incidence of phlebitis($X^2=5.008$, p=.025) according to the frequencies of IV injection between two groups.

• Tuberculosis and Respiratory Diseases
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• v.56 no.4
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• pp.374-380
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• 2004

Although exophytic endobronchial lesions can readily be diagnosed by routine forceps biopsy through the fiberoptic bronchoscope, submucosal or peribronchial tumor can be difficult to diagnose. So we evaluated the diagnostic utility of transbronchial needle aspiration (TBNA) through the fiberoptic bronchoscope in patients presenting with endoscopic abnormalities suggestive of submucosal or peribronchial tumor. Patients and Methods : Retrospective review of 120 lung cancer patients who were found to have the lesions suggestive of peribronchial and submucosal tumor during fiberoptic bronchoscopy was performed from Jan. 1994 to Dec. 2002 at Severance Hospital, Yonsei University College of Medicine. Results : Forcep biopsy was positive in 63 cases (52.5%) and TBNA in 91 (75.8%), which was significantly better than forcep biopsy (p=0.001). The combination of forceps biopsy and TBNA was positive in 106 cases (88.3%), which was significantly better than forceps biopsy alone (p=0.0001). The difference of TBNA yield according to cell type or bronchoscopic appearance of lesion was not significant, but it showed the relatively better result in small cell carcinoma. Conclusions : We concluded that TBNA significantly increase the yield over forcep biopsy alone in the detection of submucosal or peribronchial bronchogenic carcinoma.

• Food Engineering Progress
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• v.22 no.4
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• pp.309-314
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• 2018

In recent years, interest in halal authentication from the domestic food and cosmetics field has been growing for advances into the overseas halal market. For halal authentication, the product must not contain haram ingredients derived from pig, dog, human, GMO, etc. In this study, the presence of haram ingredients in plant extracts (carrot, oyster mushroom, and pine needle) treated with papain and bromelain and cosmetics (mask pack and cream) containing these extracts were analyzed by PCR to confirm whether these cosmetics were suitable for halal authentication. Detection limits of the PCR method that specifically detected template DNA of human, pig, dog, and GMO were $1.29{\times}10^3$, $1.14{\times}10^3$, $1.24{\times}10^2$ and $2.02{\times}10^3copies/tube$, respectively. PCR was not inhibited by the plant extracts or cosmetic ingredients. Results of PCR for the plant extracts or cosmetics containing these extracts were all negative. This PCR method could be used to rapidly identify the presence of haram ingredients in raw materials or final products during the manufacturing process of food and cosmetics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.147-152
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• 2012

This paper dealt with the frequency component analysis of acoustic signals produced by corona and series-arc discharges as a diagnostic technique for closed-switchboards. Corona and series-arc discharge were simulated by a needle-plane electrode and an arc generator specified in UL1699, respectively. Acoustic signal was detected by a wideband acoustic sensor with a frequency bandwidth of 4 Hz~100 kHz (-3 dB). We analyzed frequency spectrums of the acoustic signals detected in various discharge conditions. The results showed that acoustic signals mainly exist in ranges from 30 kHz to 60 kHz. From the experimental results, an acoustic detection system which consists of a constant current power supply (CCP), a low noise amplifier (LNA) and a band pass filter was designed and fabricated. The CCP separates the signal component from the DC source of acoustic sensor, and the LNA has a gain of 40 dB in ranges of 280 Hz~320 kHz. The high and the low cut-off frequency are 30 kHz and 60 kHz, respectively. We could detect corona and series-arc discharges without any interference by the acoustic detection system, and the best frequency is considered in ranges of 30 kHz~60 kHz.

• Journal of Biomedical Engineering Research
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• v.24 no.1
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• pp.9-13
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• 2003

An assist device was developed to identify the epidural space by continously monitoring the air-filled catheter pressure. The pressure signal appropriately amplified and filtered enabled to alarm the needle introduction into the epidural space by thresholding detection. Ten LEDs provided a visual change of catheter pressure before alarming for user convenience. Clinical trials were performed in 30 patients with 83% success rate at the first trial. When failed, the second trial was enough for successful anesthesia. The air volume introduced during each anesthesia was less than 1ml, causing side effects. Air filling of the catheter could also minimize infection possibility. Therefore, the present device guarantees safe anesthesia with user convenience.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1668-1670
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• 2002

Since more than two decades, the conventional PD detecting systems have been employed in order to detect the partial discharges occurring inside the HV power apparatus for their diagnosis by use of different type of detection such as acoustic and UHF detection method. Regardless of their wide on-site application, a certain number of technical inconveniences have been disclosed as follows : multistage amplification. large volume, susceptible to external noise and high price. In this respect, the optical measurement techniques are widely proposed in these days in this concerned field ascribed to the following advantages : immune to external EMI noise and broad band response of the Pockels cell covering from DC to GHz. However, the reliability of several proposed techniques enabling to measure the electric field inside the large high power apparatus has not yet been well approved In this work, an optical measuring system, based on the Pockels effect, has been developed for measuring the field variation due to the corona discharges occurring in air and in oil. This system consists of He-Ne laser, single mode optical fiber, multi mode optical fiber, polarizing film, Y-cut LiNbO3 cell, photo detector, digital oscilloscope and personal computer with GPIB. For this purpose, optical probe has been specially designed and realized and put into the needle-plane electrode. Afterward, same measurement is carried out in oil. We demonstrate the characteristic of the optical measuring system and the measurement results.

• Korean Journal of Head & Neck Oncology
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• v.15 no.2
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• pp.177-181
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• 1999

Objective: The clinical significance of mass screening for thyroid carcinoma remains unclear. This study was carried out to clarify the value of mass screening for thyroid carcinoma. Materials and Methods: From December 1997 through July 1998, a total of 1,401 subjects who were enrolled to receive breast screening or follow-up examination for breast cancer were included in this study. Thyroid glands were examined by 10 MHz ultrasonography by one experienced radiologist. The patients with thyroid nodules were classified into 2 groups according to their potential risk of malignancy by ultrasonographic findings(high-risk : hypoechogenicity, microcalcification, irregular margin, taller than wider shape). High-risk patients were advised to undergo fine-needle aspiration biopsy and thyroidectomy. The characteristics of the thyroid cancers detected by ultrasonographic mass screening were compared by those of clinical thyroid cancer excluding male patients during the same period. Results: Thyroid nodules were detected in 353(25.2%) of the subjects and 259(73.4%) were listed in the low-risk group and 94(26.6%) in high-risk group. Among 94 patients in the high-risk group, 43 underwent thyroidectomy and 37 turned out to have thyroid carcinomas. Thus, the detection rates for carcinoma were 2.6% of all subject, 10.5% of the detected nodules, 36.4% of the high risk women and 86.0% of the operated cases. The tumor size was significantly smaller in the mass-screening group than in the clinical cancer group(p<0.05). However, there was no statistical differences between two groups in the prevalences of neck node involvement and extracapsular invasion and the patients distributions by AMES score, MACIS score and TNM stage. Conclusion: Ultrasonogrpahic mass screening may be useful for the early detection of thyroid carcinoma in women who are scheduled to have breast examination.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2771-2776
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• 2014

Background: Breast cancer screening and higher quality mammography have resulted in an increase in the diagnosis of ductal carcinoma in situ worldwide. We compared the incidence and other factors in our cases of ductal carcinoma in situ between two recent decades. Materials and Methods: Medical records of cases of ductal carcinoma in situ who had been admitted to the surgery wards of the Cancer Institute of Tehran, Iran were evaluated from March 1993 to March 2003 as phase 1, and from April 2003 to April 2013 as phase 2. Results: Ratio of ductal carcinoma in situ to overall breast cancer was 1.27 and 3.93 in phases 1 and 2, respectively. Rates of excisional or incisional biopsies versus core needle biopsies and clinically versus mammographically detected cases as well as median size of tumors dropped between the 2 phases while a substantial rise in the number of patients attending for screening was seen in this time period. Surgical treatments followed a trend from modified radical mastectomy and axillary lymphatic dissection toward breast conserving surgery and sentinel node dissection or no axillary intervention. Conclusions: Our study shows a considerable trend toward earlier detection of breast cancer and evolution of treatment strategies toward standard less invasive surgery of DCIS in Iran.