• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.125-135
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• 2023

Here, we investigated the observed sunspot areas with respect to latitudes using the Hilbert transform technique. Conventional study of the cyclic patterns of sunspots is based on the Lomb-Scargle periodogram, which only obtains the amplitude information. In comparison, our approach characterizes the amplitude as well as the phase of solar activity. We demonstrated the solar North-South asymmetry in the instantaneous amplitude by analyzing daily sunspot data set spanning from the solar cycles 11 to 24. Our findings confirm that the northern hemisphere is dominant in the solar cycles 14, 15, 16, 18, and 20. Unlike the amplitude, the North-South asymmetry in the period of solar activity could not be established. We have also found that the standard deviation as a measure of fluctuation in the phase derivative is minimum in the latitude band 10° < l < 20°, and the fluctuations obtained for latitudes above 30° are considerable.

• Journal of Life Science
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• v.32 no.11
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• pp.841-846
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• 2022

The purpose of this study was to evaluate the antioxidant properties of Rosa rugosa extract and to identify which of its components are responsible for these properties. Reactive oxygen species play an important role in diseases such as cancer, arteriosclerosis, and heart disease as a consequence of increased metabolic rates, gene mutations, and relative hypoxia. Therefore, the antioxidant effect of R. rugosa extract was confirmed by HPLC, HPLC-MS/MS, the total polyphenol content, the total flavonoid content, and the radical scavenging activity. HPLC and HPLC-MS/MS analyses were conducted to identify and quantify the main components of the R. rugosa extract. Gallic acid and epigallocatechin gallate were identified as the main components, with 17.4 and 4.35 mg/g dry matter (DM), respectively. The antioxidant activity of R. rugosa extract was evaluated based on its total polyphenol content, total flavonoid content, and radical scavenging activity, which were 72.3 mg gallic acid equivalent/g DM, 11.2 mg quercetin equivalent/g DM, and 87.9%, respectively. The radical scavenging activities of the main components, gallic acid and epigallocatechin gallate, were 80.5% and 89.7%, respectively. Therefore, R. rugosa has a high polyphenol content and antioxidant activity, and it can be used as a natural antioxidant in food, cosmetics, and pharmaceuticals.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.187-194
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• 2023

The remote sensing technique of measuring the magnetic field was applied first to sunspots by Hale (1908). Later Babcock (1961) showed that the solar surface magnetic field on a global scale is a dipole in first-order approximation and that this dipole field reverses once every solar cycle. The Wilcox Solar Observatory (WSO) supplies the spherical harmonics coefficients of the solar corona magnetic field of each Carrington Rotation, calculated based on the remotely-sensed photospheric magnetic field of the solar surface. To infer the internal current system producing the global solar coronal magnetic field structure and evolution of the Sun, we calculate the multipole components of the solar magnetic field using the WSO data from 1976 to 2019. The prominent cycle components over the last 4 solar activity cycles are axis-symmetric fields of the dipole and octupole. This implies that the current inversion driving the solar magnetic field reversal originates from the equatorial region and spreads to the whole globe. Thus, a more accurate solar dynamo model must include an explanation of the origin and evolution of such solar internal current dynamics.

• Journal of Nutrition and Health
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• v.40 no.6
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• pp.576-583
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• 2007

The purpose of this study was to assess the daily steps, physical activities and activity coefficient of policemen (average age: 31.5 ${\pm}$ 5.1 years) who do shift work. Body weight, height and daily steps were measured and one-day activity diary was collected by interviewing with policemen. Average height, body weight, BMI, body fat (%) and muscles (%) of subjects were 173.1 ${\pm}$ 5.2 cm, 73.7 ${\pm}$ 9.7 kg, 24,6 $kg/m^{2}$, 15.5 ${\pm}$ 1.9% and 37.3 ${\pm}$ 5.8%, respectively. The average daily numbers of steps were found to be 9,812 steps/day on day shift duty and 10,888 steps/day on night shift duty and 6,551 steps/day on holiday duty. Hourly step rates on day shift, night shift and holiday came to 1946 steps/hr, 2,130 steps/hr and 1,318 steps/hr, respectively. Activity coefficient (1.75) in night shift of the subjects was the highest and activity coefficient (1.52) in day shift was significantly higher than that (1.31) in holiday (p < 0.05). The rate of expending time for very light activity in holiday (91.5%) was significantly higher than that (70.0%) in night shift. The muscle mass (kg, %) had significantly positive relationship with daily steps in day shift (r = 0.592, r = 0.632) and night shift (r = 0.550, r = 0.503). Triceps skinfold thickness was negatively correlated with daily steps in day shift (r = -0.366, p < 0.05). There were remarkable differences in physical activities and sleeping hours depending on shift works of policemen. In the case of night shift work, sleeping hours was the lowest and activity coefficient was the highest among day shift, night shift and holiday. These results suggest that energy requirements of policemen should be differentiated according to shift work duty.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.672-673
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• 2003

• 대한핵의학회:학술대회논문집
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• 1972.11a
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• pp.68.2-68.2
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• 1972

• The Korean Journal of Physiology
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• v.16 no.1
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• pp.63-68
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• 1982

The change of plasma renin activity is one of the most important parameters explaining the pathological physiology of the hypertension. The relation between renal renin activity and plasma renin activity has not well been documented since last decades. In an attempt to clarify the relationship a series of experiments have been done in rats. The following results were observed. 1) Renal renin activity of clamped kidney increased after silver clipping and the increments were maintained until four to five weeks of operation. 2) Renal renin activity of the untouched contralateral kidney was vulnerable to be suppressed just after clamping, and the activity disappered almost below the limitation of the radioimmunoassay sensitivity up to four weeks. 3) Plasma lenin activity was changed by the renal renin activity, but the regression coefficient from the two kidney one clip Goldblatt hypertensive rats was different from the sham-operated, or age-matched control rats. 4) Plasma renin activity of all the groups tested has the exponential curve in terms of renal renin activity. These data suggest that the renal renin activity is important to control the plasma renin activity in certain experimental condition, especially in chronic status.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.12
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• pp.1793-1798
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• 2015

Antioxidant activities of various solvent extracts from Coriolus versicolor were investigated for their total polyphenol content, total flavonoid content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging activity. C. versicolor extracts were produced by organic solvents such as ethanol, ethyl acetate, and methanol. Total polyphenol and flavonoid contents in the ethanol and ethyl acetate extracts were higher than those in the methanol extract. DPPH radical scavenging activity of methanol extract showed the highest value of 80.3%, which was similar to that of ascorbic acid (85.5%). All extracts showed good (>90.0%) ABTS cation radical scavenging activity. The antimicrobial activities of these extracts from C. versicolor were evaluated against six strains of bacteria using the disc diffusion method. All extracts showed antimicrobial activities against all tested bacteria except Staphylococcus aureus. These results indicate that various extracts from C. versicolor could be useful as natural antioxidant and antimicrobial agents.

• Korean Journal of Medicinal Crop Science
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• v.19 no.5
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• pp.368-372
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• 2011

In this study, we investigated on antioxidative activity and nitric oxide production inhibitory activity of various solvent extracts of Lespedeza bicolor. The total polyphenol content of the methanol extract was 192.6 mg/g and flavonoid content of the acetone extract was 40.6 mg/g, as the highest content. In DPPH radical scavenging ability, $SC_{50}$ values of the ethanol and methanol extract were exhibited $0.69mg/m{\ell}$ and $0.89mg/m{\ell}$, respectively. However, in nitric oxide(NO) scavenging ability, $SC_{50}$ values of the acetone was exhibited $0.72mg/m{\ell}$ as the highest activity. Moreover, the acetone extract showed strong NO production inhibitory effect in lipopolysaccharide(LPS)-stimulated Raw 264.7 cell. In the cytotoxicity measurement by MTT assay, the extracts were exhibited Raw 264.7 cell viabilities of 92.57~129.04% as nontoxic result in concentration of $65{\sim}650{\mu}g/m{\ell}$. As a result, the acetone extract of L. bicolor could be applicable to functional materials for anti-inflammatory related fields.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.55-60
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• 1997

A lysosomal and matrix degrading enzyme $\beta$-glucuronidase activity was measured in BALS/c mice fed high and low Ca in combination with the i.p. adminstration of calcium-regulating hormones including parathyoid hormone(PTH), calcitonin(CT) and cholecalciferol(Vit D). After feeding experimental diets for five weeks, mice were sacrificed by cervical dislocation and the enzyme was fluometrically measured at 440nm. $\beta$-Glucuronidase activity was inhibited by high calcium in the diet. in addition, vitamin D also inhibited the enzyme activity in the serum regardless of the level of dietary calcium. In contrast, PTH has shown to stimulate the enzyme at all the levels of dietary calcium. Calcitonin, and inhibitor of PTH action for bone resorption, revealed to curb PTH effect in this enzyme, whereas CT stimulated the action of vitamin D in the serum. The above results led us to conclude that osteoclastic bone resorption and senile osteoporosis may be reduced by adequate dietary calcium and vitamin D.