• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.459-464
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• 2017

Biphenyl is used as an intermediate in the production of crop protection products, a solvent in pharmaceutical production, and as a component in the preservation of citrus fruits in many countries. Biphenyl is not authorized for use and also does not have standards or specifications as a food additive in Korea. National and imported food products are likely to contain biphenyl. Therefore, control and management of these products is required. In this study, a simple analytical method was developed and validated using HPLC to determine biphenyl in food. These methods are validated by assessing certain performance parameters: linearity, accuracy, precision, recovery, limit of detection (LOD), and limit of quantitation (LOQ). The calibration curve was obtained from 1.0 to $100.0{\mu}g/mL$ with satisfactory relative standard deviations (RSD) of 0.999 in the representative sample (orange). In the measurement of quality control (QC) samples, accuracy was in the range of 95.8~104.0% within normal values. The inter-day and inter-day precision values were less than 2.4% RSD in the measurement of QC samples. Recoveries of biphenyl from spiked orange samples ranged from 92.7 to 99.4% with RSD between 0.7 and 1.7% at levels of 10, 50, and $100{\mu}g/mL$. The LOD and LOQ were determined to be 0.04 and $0.13{\mu}g/mL$, respectively. These results show that the developed method is appropriate for biphenyl identification and can be used to examine the safety of citrus fruits and surface treatments containing biphenyl residues.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.331-338
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• 1996

Background : Lung cancer continues to be the leading cause of cancer death in the United States and it's incidence has been rapidly increasing in Korea, too. The overall cure rate for non-small cell lung cancer(NSCLC) is approximately 10%, and the cure is generally achieved by surgery. Unfortunately, however, less than 15% of all patients and less than 25% of those who present with localized disease are candidates for curative surgical resection. So preoperative staging evaluation followed by curative resection has a major role in determining the long tenn prognosis of NSCLC patients. Therefore, we have conducted this study to compare pre-operative and post-operative staging and the long-tenn relapse-free survival rates in NSCLC patients according to its stage. Methods : We analyzed the medical records of 217 NSCLC patients who were operated on for curative resection in Seoul National University Hospital, retrospectively. Among them, 170 patients who were completely resected were selected to determine the long term relapse-free survival rates. Results : Among 217 NSCLC patients, men were 157 and women were 30. The median age was 58 and the difference between men and women was not found. The discrepancy rate between preoperative and postoperative staging was 40.1%. Its major cause was due to the difference of nodal staging. The 3-year relapse-free survival rates were 73%, 53% and 48% in stage I, II and IIIa, respectively. There was no difference of relapse-free duration in recurred patients according to the stage or histologic types. Conclusion : The postoperative pathologic staging determines the long tenn prognosis of patients with NSCLC after surgery, but current preoperative clinical staging can not predict the postoperative pathologic staging correctly. So the improved modality of staging system is required to predict the pathologic staging more correctly.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.488-497
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• 1999

Background : Identification of the histologic cell type of lung cancer is important because it is related to the treatment modality and prognosis. Currently, many diagnostic methods are used to determine the cell type. We have studied to evaluate the histologic accuracy of each diagnostic methods in lung cancer. Method : 168 cases were analysed retrospectively, who underwent curative thoracotomy for lung cancer in Seoul National University Hospital from January, 1994 to February, 1997. Sputum cytology, percutaneous needle aspiration(PCNA), percutaneous needle biopsy(PCNB), bronchial washing cytology and flexible bronchoscopic biopsy were evaluated respectively. The k coefficient was applied to evaluate the degree of concordance between the histologic diagnosis obtained by each methods and the one derived from thoracotomy. Results : The k value in sputum cytology was 0.86. In the 34 cases with squamous cell carcinoma(SQ), 32 cases were finally diagnosed as having such by thoracotomy. 7 of the 8 cases with adenocarcinoma(AD) turned out to have the same. The k value in PCNA was 0.51. In the 31 cases with SQ, only 14 cases were finally diagnosed as having such. All of the 3 cases with small cell carcinoma(SC) turned out to have the same. The k value in PCNB was 0.77. The diagnosis was correct in 13 of the 16 patients with SQ and in 30 of the 32 cases with AD. The k value in bronchial washing cytology was 1.0. In all of the 29 cases with SQ and all of the 7 cases with AD, the diagnosis was correct. The k value in flexible bronchoscopic biopsy was 0.77. The diagnosis was correct in 51 of the 52 cases with SQ and in 1 of the 2 cases with SC. Conclusion : The concordance rate with the final histologic diagnosis in sputum cytology, PCNB, bronchial washing cytology and flexible bronchoscopic biopsy were excellent ($k{\geq}0.75$), while that in PCNA was fair (k=0.53). Because PCNA showed lower concordance rate than other diagnostic methods, PCNA is recommended to perform with PCNB.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.785-794
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• 1998

Background: Chemical pleurodesis is a widely used method for the control of symptomatic and recurrent malignant pleural effusions. Talc has been accepted to be the most effective sclerosing agent for chemical pleurodesis. This study was undertaken to evaluate the usefulness of talc pleurodesis via video-assisted thoracoscopic surgery (VATS) in treatment of malignant pleural effusions. Methods : A retrospective analysis of the medical records and radiographic findings was performed. The success of the procedure was defined as daily pleural fluid drainage below 100ml within 1 week after pleurodesis and complete expansion of the lung on simple chest radiograph. Recurrence was defined as reaccumulation of pleural fluid on follow-up chest radiographs, and complete response as no fluid accumulation on follow-up chest radiographs. Results: Between October 1994 and August 1996, talc pleurodesis via VATS was performed in 35 patients. Duration of follow-up ranged from 5 days to 828 days(median 79days). The initial success rate of procedure was 88.6%(31 of 35 cases). Complete responses were observed in 92.8% at 30 days, 75.7% at 90 days and 64.9% at 180 days. Postoperative complications were fever (54.3%), subcutaneous emphysema(11.4%), reexpansion pulmonary edema(2.9%) and respiratory failure(5.7%). But procedure related mortality or respiratory failure was not found. Conclusion: Talc pleurodesis via VATS is a safe and effective method for the control of symptomatic malignant pleural effusions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.10
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• pp.1449-1455
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• 2006

Raw oysters were treated at $10^{\circ}C$ and $22^{\circ}C/350$ Mpa/15 min, and microbial counts and quality were measured during storage of 14 days at $10^{\circ}C$. Total viable cell count (TVCC) in untreated oyster increased greatly during storage from starting inoculum of $1.6\times10^2\;CFU/mL$, and reached to $5.6\times10^2\;CFU/mL$ after 4 days of storage. TVCC of the pressure-treated was about $10^1\;CFU/mL$ right after high hydrostatic pressure treatment and increased slowly during storage, and about $10^3\;CFU/mL$ even after 7 days of storage. Lactic acid bacteria count (LABC) in the untreated was increased greatly during storage from starting inoculum of $3.3\times10^3\;CFU/mL$ at 3 days of storage and $7.2\times10^4\;CFU/mL$ after 4 days of storage. LABC in the pressure-treated was detected only after 5 days of storage, and about $10^2\;CFU/mL$ after 8 days of storage. The pH of the untreated was 6.19 and decreased gradually during storage, and 5.83 after 4 days of storage. The pH of the pressure-treated showed little change during storage, and 6.07, 6.03 and 5.82 after storage of 4, 8 and 14 days, respectively. Volatile basic nitrogen (VBN) in the untreated was 16.8 mg%, and maintained almost constant until 1 day of storage, and then increased suddenly, and 30.1 mg% after 4 days of storage. VBN of the pressure-treated stayed unchanged during storage, and about 20 and 23 mg% even after 4 and 8 days of storage, respectively. Hunter $L^*,\;a^*\;and\;b^*$ values were increased until 2 days of storage and then showed no change during storage. Demerit score was the lowest in the thawed raw oyster, and then in the increasing order of the pressure-treated (4 day and 8 day storage) and the untreated (4 day storage).

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.251-255
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• 2008

Cholesterol and cholesterol oxide products (COPs) of Gulbi (Pseudosciaena manchurica) processed and stored at different salting times of 5 hours and 5 days were analyzed. The content of cholesterol was $133.4{\pm}5.20\;mg/100\;g$ in the fresh sample. Cholesterol content was decreased during salting and storage; its contents were $130.3{\pm}2.95\;mg/100\;g$ and $87.2{\pm}3.49\;mg/100\;g$ in 5 hours and 5 days salting samples, respectively. The content of 7-ketocholesterol in 5 hours and 5 days salting samples were $75.2{\pm}2.70\;{\mu}g/100\;g$ and $82.4{\pm}3.30\;{\mu}g/100\;g$. The 7-ketocholesterol content of salting sample for 5 hours had no significantly difference for 2 days sun drying, but it was dramatically increased during 5 days sun drying and then increased during storage days. $7{\alpha}-$ and $7{\beta}-hydroxycholesterol$ were not detected in fresh sample, but increased during Gulbi processing and storage. The $7{\alpha}-hydroxycholesterol$ was increased during Gulbi processing and storage and a higher level of $658.1{\pm}6.20\;{\mu}g/100\;g$ was detected in 5 hours salting sample than in 5 days salting sample after 21 days storage. The $7{\beta}-hydroxycholesterol$ also showed similar tendency with $7{\alpha}-hydroxycholesterol$; it was largely increased between 7 and 14 days storage in 5 days salting sample.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.34-43
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• 1996

We investigated the vegetation structure, and effects of canopy degree(gap or purlieu to 25%, 50%, 75%, over 75%) of the overstory on seedling regeneration and survivorship, and sapling density, growth and growth type of Abies koreana in subalpine of Mt. Chiri. The stem density in Abies koreana stand was higher in middle story than upper story, individual trees in upper story occupied larger area and were more apart, resulted in uniform distribution. The regeneration and survivorship of seedlings and saplings were best in 25% of crown closure, in order of 50%, gap, but lowest in over 75% of crown closure. The annual growth rate and recent 5 years growth rate of saplings were highest in gap or purlieu and getting lower toward gradually higher coverage of overstory. And 10- to 20-Year-old saplings were mainly regenerated in stands with lower density(I or II), but most of 20 to 30 years old saplings were growing in stands with higher density (III or IV). The number of "A" type saplings grown normally in gap or purlieu was gradually decreased in stand with higher density but the number of "D" or "E" types of which growth was supressed or prohibited by the high density was abruptly increased. Saplings normally growing in the gap and purlieu showed the panicle type, but those grown under dense crown were greatly suppressed and showed the umbellate type.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.556-566
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• 2010

A new kinetic spectrophotometric method is developed for the measurement of Mn(II) in natural water samples. The method is based on the catalytic effect of Mn(II) with the oxidation of Gallocyanin by $KIO_4$ using nitrilotriacetic acid (NTA) as an activation reagent at 620 nm. The optimum conditions obtained are $4.00{\times}1^{-5}\;M$ Gallocyanin, $KIO_4$, $1.00{\times}10^{-4}\;M$ NTA, 0.1 M HAc/NaAc buffer of pH = 3.50, the reaction time of 5 min and the temperature of $30^{\circ}C$. Under the optimum conditions, the proposed method allows the measurement of Mn(II) in a range of $0.1\;-\;4.0\;ng\;mL^{-1}$ and with a detection limit of down to $0.025\;ng\;mL^{-1}$. The recovery efficiency in measuring the standard Mn(II) solution is in a range of 98.5 - 102%, and the RSD is in a range of 0.76 - 1.25%. The newly developed kinetic method has been successfully applied to the measurement of Mn(II) in both some environmental water samples and certified standard reference river water sample, JAC-0031 with satisfying results. Moreover, few cations and anions interfere with the measurement of Mn(II). Compared with the other catalytic-kinetic methods and instrumental methods, the proposed kinetic method shows fairly good selectivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can easily and successfully be applied to the real water samples with relatively low salt content and complex matrices such as bottled drinking water, cold and hot spring waters, lake water, river water samples.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.175-184
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• 2008

To screen highly active Bacillus thuringiensis isolates against Spodoptera litura (Lepidoptera, Noctuidae), 46 B. thuringiensis was isolated from 115 samples obtained from several crop soils. Especially, B. thuringiensis subsp. kurstaki CAB133 and CAB162 isolates showed 100% mortality against S. litura. $LD_{50}$ values of CAB 133, CAB162 and HD-1 strains of B. thuringiensis subsp. kurstaki were 0.089, 3.144 and $0.513{\mu}g/ml$ against 2nd larva of S. litura, respectively. The weight of 3rd larva of S. litura which were fed crystal inclusion protein $(1.267{\mu}g/ml)$ with B. thuringiensis subsp. kurstaki CAB133 was about 30 times lass than control group. CAB133 and CAB 162 strains of B. thuringiensis subsp. kurstaki which were taken a highly toxity against S. litura were analyzed by SDS-PAGE, and estimated the molecular weight of the Cry proteins. Their serological identification by H serotypes were showed B. thuringiensis subsp. kurstaki (3abc) type.

• Journal of Bio-Environment Control
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• v.18 no.2
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• pp.166-170
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• 2009

The temperature fluctuations was investigated in cold distribution chain of radish sprout, typical of commercial practice. Although the temperature of distribution chain was maintained below 5$^{\circ}C$ in precooling and packaging steps, and 10$^{\circ}C$ in transporting, temperature of loading step increased up to 18$^{\circ}C$ at market. Based on this investigation, the simulated cold distribution conditions were consisted of precooling and packaging step; 5$^{\circ}C$ for 12 hours and transporting and loading steps; 5$^{\circ}C$, 10$^{\circ}C$, 20$^{\circ}C$ and $^{\circ}C$ for 6 hours, and storage and market steps; 5$^{\circ}C$ and 10$^{\circ}C$ for 17 days. The radish sprouts were cultivated at 25$^{\circ}C$ and dark condition for S days and placed in light condition for greening. They were packaged by 25 ${\mu}m$ ceramic film after precooling for 6 hours in 5$^{\circ}C$. The fresh weight loss and visual quality of radish sprout decreased with the increase of the temperature in transporting and loading steps. The carbon dioxide content of packages increased, but the oxygen content decreased rapidly in 1day after storage, as the temperature of transporting and loading steps increased. The ethylene content in packages increased fastest in higher temperature of transporting and loading steps treatment, and showed highest in 5$^{\circ}C$-30$^{\circ}C$-10$^{\circ}C$ treatment (temperature of precooling and packaging steps for 12 hours - temperature of transporting and loading steps for 6 hours - temperature of storage step for 14 days) followed by 5$^{\circ}C$-20$^{\circ}C$-10$^{\circ}C$ treatment. The high temperature of transporting and loading steps resulted in deterioration qualities and atmosphere conditions in packages of sprout. These results suggested that the temperature fluctuation in distribution should influence the shelf-life of radish sprouts, even thought the periods of fluctuation was just 6 hours.