• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5829-5834
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• 2012

Background: Breast cancer is the most common cancer in women worldwide. Although different metabolic factors have been implicated in breast cancer development, the relationship between hypertension and breast cancer has not been elucidated. Aim: To evaluate hypertension as a risk factor for breast cancer in Chilean women of low and middle socio-economic status. Methods: We conducted an age-matched (1:1) case-control study in 3 hospitals in Santiago, Chile. Breast cancer cases (n=170) were histopathologically confirmed. Controls had been classified as Breast Imaging Reporting and Data System I (negative) or II (benign findings) within 6 months of recruitment. Blood pressure was measured using a mercury sphygmomanometer and standardized procedures. We used 2 hypertension cut-off points: blood pressures of ${\geq}140/90$ mmHg and ${\geq}130/85$ mmHg. Fasting insulin and glucose levels were assessed, and anthropometric, sociodemographic, and behavioral information were collected. Odds ratios and 95% confidence intervals were estimated for the entire sample and restricted to postmenopausal women using multivariable conditional logistic regression models. Results: Hypertension (${\geq}140/90$ mmHg) was significantly higher in cases (37.1%) than controls (17.1%) for the entire sample and in postmenopausal pairs (44.0% compared to 23.8%). In crude and adjusted models, hypertensive women had a 4-fold increased risk of breast cancer (adjusted odds ratio: 4.2; 95% confidence interval: 1.8; 9.6) compared to non-hypertensive women in the entire sample. We found a similar association in the postmenopausal group (adjusted odds ratio: 2.8; 95% confidence interval: 1.1; 7.4). A significant effect was also observed when hypertension was defined as blood pressure of ${\geq}130/85$ mmHg. Conclusion: A significant association was found between hypertension and breast cancer over the entire sample and when restricted to postmenopausal women. Hypertension is highly prevalent in Latin America and may be a modifiable risk factor for breast cancer; therefore, a small association between hypertension and breast cancer may have broad implications.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.1
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• pp.5-10
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• 2011

The effect of sample handling condition on the rheological measurement of regenerated silk fibroin formic acid solution using parallel plate geometry was investigated. In case of loading method, the loading by pouring sample solution resulted in the best reproducibility of rheological measurement. Loading with spoon showed a high variance of viscosity value at low shear rate region ($0.01{\sim}1sec^{-1}$) while loading with syringe exhibited a low reproducibility of viscosity at high shear region ($1{\sim}100sec^{-1}$) with a disappearance of shear thinning phenomenon. It was revealed that the sample loading with small extra amount lead to the most reproducible result. The sample loading with the exact amount for the measuring plate resulted in a lack of reproducibility of high shear viscosity, while the loading with large extra volume produced a limited consistency of low shear viscosity. It was turned out that 3 min. of waiting time before measurement was the optimum condition for reliable result. When the waiting time was less than 1 min., the low shear viscosity was obtained with a lack of consistency. On the other hand, the sample solution started drying when the waiting time increased up to 5 min.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3788-3794
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• 2022

The possibility of denuclearization of the Korean Peninsula has been continuously debated, and the initiative participation of the Republic of Korea has necessitated preemptive measures against neighboring countries. In this study, we present a proposal for formulating a site survey plan when the amount of site information provided is insufficient and the accuracy of the information is not guaranteed. Considering a case wherein "a soil sample analysis is used to determine the presence or absence of nuclear activity" in a radiochemical laboratory, which is a typical key facility for denuclearization, the optimal soil sample collection plan is designed based on international guidelines and public information. In the event of denuclearization, a scenario that is not based on the expertise of the sample collector is set, and the data quality objective (DQO) process is applied to ensure reality. Consequently, the primary sample collection points can be derived in consideration of accessibility, and the sample collection scale can be adjusted according to the cost. By applying the DQO process to ensure sample representativeness and reality, reliable and resource-efficient soil sample collection can be achieved in radiochemical laboratories and other denuclearization facilities.

• Journal of the Korean Applied Science and Technology
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• v.41 no.2
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• pp.520-529
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• 2024

Lycium barbarum extract has a high potential to be developed as a health functional food due to the various health-promoting effects of Lycium barbarum. This study analyzed changes in nutritional and functional components depending on the extraction solvent (purified water and a mixture of purified water and alcohol) and the condition of the sample. The nutritional components (carbohydrates, protein, fat, ash), organic acids, amino acids, total phenolic compounds, and total flavonoids of the extract produced during the extraction process were analyzed. The nutritional composition and functional substances of the extracts showed some differences depending on the type of solvent and the condition of the sample. The amounts of crude protein (7.61%), crude fat (1.63%), carbohydrate (90.22%), and ash (0.54%) of dried Lycium barbarum extract using purified water as a solvent were similar to those of the powder sample extract. The highest content of citric acid was 4.31 mg/mL, similar to the case of acetic acid, when the powder sample used a mixture of purified water and alcohol as a solvent. The highest amino acid content was 357.39 mg/mL when the powder sample was mixed with purified water and alcohol as a solvent. The total amount of phenolic compounds was 686.16 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent. The highest total flavonoid content was 111.32 g/L when the powder sample was extracted with a mixture of purified water and alcohol as a solvent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2251-2258
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• 2012

This study compared the unweighted sample design, frequency weighted sample design and complex sample design to using 2009 Korea National Health and Nutrition Examination Survey in an effort to identify whether or not there is any difference in potential risk factors. Pearson chi-square test and Rao-scott chi-square test were applied to the analytic methods. As a result of analyses, all the variables were overestimated as significant risk factors in case of the unweighted sample design to which only the frequency weights were applied. In addition, there were differences in the confidence levels and results from the simple random sampling analysis and complex sample design to which no weight was applied. It is necessary to carry out the complex sample design rather than the analysis to which the frequency weights are applied, in order to ensure the findings to represent the whole population when our national statistics data is used.

• The Mathematical Education
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• v.19 no.2
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• pp.19-22
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• 1981

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.149-152
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• 2014

Purpose: At our hospital blood is collected from a patient before an imaging test, with the concern of any effect possible when a nuclear medicine imaging test and an in-vitro test are carried out at the same time. However, occasionally, the blood collection is performed after an imaging test, with the reasons that the patient is not properly guided or the patient doesn't follow the guide correctly. In that case, we prefer to gather blood again after a few days. The purpose of this study is not only to see whether there is any effect of an imaging test on the result of the in-vitro test performed with the blood collected after the imaging test, but also to study how many days waiting after each test is appropriate to take a blood sample, if the effect exists. Materials and Methods: From September to October 2013, blood were collected from 13 patients in our hospital regardless of age and sex each time before and after the injection of the radioactive isotope from the tests : PET-CT, Gated Myocardial SPECT, and DTPA GFR Scan. Considering a half-life, AFP, CA19-9, CEA, TSH, and T3 were carried out right after the blood collection. In case of an iodine therapy, blood were taken each time before and after taking radioactive iodine, and, after AFP, CA19-9, and CEA, the difference between them in consistency and in cpm were compared. Results: With 10 patients after the imaging tests and 3 patients after the iodine therapy, their serum cpm was over 10,000. Over time, the cpm decreased in accordance with the half-life ($^{18}F$ 110minutes, $^{99}mTc$ 6hours, $^{201}Tl$ 72hours, $^{131}I$ 7days). Between the two cases, one before and the other after the injection of the radioactive isotope, the cpm and the results of AFP, CA19-9, CEA, TSH, and T3 from three patients each test, PET-CT, Gated Myocardial SPECT, and DTPA GFR Scan, were very similar. In addition, in case of an iodine therapy, there was also not a meaningful difference in the cpm and the results of AFP, CA19-9, and CEA, from three patients in an iodine therapy, between the two cases, one before and the other after taking the radioactive iodine. Conclusion: In case a blood collection was performed after the imaging test which required a radioactive isotope injection, the cpm increased, differently according to the kind of the radioactive isotope. However, the results of the in-vitro tests like AFP, CA19-9, CEA, TSH, T3, etc were nearly not affected. As the result, it's considered that there will not be any significant effect also from other tests, as the result from the performed seven tests.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.837-842
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• 2015

In this study, the characteristics of electrostatic attenuation in plain shape glass filament sample (0.29 mm thickness, cross section of $12.25cm^2$, $16cm^2$, $20.25cm^2$) for insulator has been measured at temperature of $5^{\circ}C{\sim}38^{\circ}C$, humidity of 50%~90%. The results of this study are as follows. In case of samples that the cross section is $12.25cm^2$, $16cm^2$, $20.25cm^2$ at humidity of 50%~90%, it found that the electrification voltage of electrostatic increased with increasing temperature, with a return to decrease at $20^{\circ}C$. In case of samples that the cross section is $12.25cm^2$, $16cm^2$, $20.25cm^2$ at temperature of $5^{\circ}C{\sim}38^{\circ}C$, it found that the electrification voltage of electrostatic decreased with increasing humidity. In case of the sample at temperature of $20^{\circ}C$ and humidity of 65%, 75%, it found that the electrification voltage of electrostatic increased with increasing cross section. In case of the sample at humidity of 65% and cross section of $12.25cm^2$, the time that it takes to reduce electrification voltage of electrostatic in half decreased to 0.912s, 0.736s, 0.673s with increasing temperature to $10^{\circ}C$ $20^{\circ}C$, $30^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.2 no.2
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• pp.57-65
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• 1987

ABSTRACT - To examine antihypertensive components of Ganoderma lucidum in Korea, two kinds of fruiting bodies (J and K) were used for extraction with water and the extracts were purified by ethanol precipitation and dialysis. Three fractions, i.e., the aqueous total extract(A), the ethanol supernatant(B} and the purified precipitate(C), were compared for antihypertensive activity in anesthetized spontaneously hypertensive rats (SUR). Although fractions A and B showed the activity, fraction C did not. Particularly, fraction B of sample K produced 44.3% reduction in diastolic blood pressure and 30.6% reduction in heart rate after i.v. administration of a dose of 10 mg/kg. Direct effects of this fraction B to the heart were observed in the isolated blood perfused heart preparation of the dog. It induced positive chronotropic and inotropic responses dose-dependently in the case of sample J. In the case of sample K, marked chronotropic and inotropic effects on atrial muscle but not on ventricular muscle were induced. In both samples, coronary blood flow (CBF) was dose-relatedly increased.reased.