• Tuberculosis and Respiratory Diseases
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• v.83 no.4
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• pp.268-275
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• 2020

Background: It is not evident that the attributable risk of smoking on mortality in Korea has decreased. We investigated the impact of smoking on all-cause mortality and estimated the attributable risk of smoking in Korean adults. Methods: Those aged ≥20 years with smoking history in the Korean National Health and Nutrition Examination Surveys (KNHANES) 2007-2015 were enrolled. We categorized the participants into three groups as follows: never smoker, <20 pack-years (PY) smokers, and ≥20 PY smokers. We applied inverse probability weighting using propensity scores to control various confounders between the groups. All-cause mortality risks were compared between the groups using the Kaplan-Meier log-rank test. The effects of smoking-attributable risks (ARs) on mortality were also calculated. Results: A total of 50,458 participants were included. Among them, 19,334 (38.3%) were smokers and 31,124 (61.7%) were never smokers. Those with a smoking history of 20 PY or more (≥20 PY smokers), those with a smoking history of less than 20 PY (<20 PY smokers), and never smokers were 18.1%, 20.2%, and 61.7%, respectively, of the study population. Smokers had a higher risk of all-cause mortality compared to never smokers (log-rank test p<0.01). The ARs of smoking were 21.8% (95% confidence interval [CI], 5.7%-37.9%) and 9.0% (95% CI, 6.1%-12.0%) in males and females, respectively. ARs decreased from 24.2% to 19.5% in males and from 9.5% to 4.1% in females between 2007-2010 and 2011-2015. Conclusion: Our study using KNHANES IV-VI data demonstrated that smoking increased the risk of all-cause mortality in a dose-response manner and the ARs of smoking on mortality were 21.8% in males and 9.0% in females during 2007-2015. This suggests that the ARs of smoking on mortality have decreased since around 2010.

• Journal of Biosystems Engineering
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• v.10 no.2
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• pp.27-35
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• 1985

This study was carried out to determine the optimum size and number of farm machines for various sizes of land coverage of the cooperative farm machinery utilization systems in Korea-namely Saemaul Mechanized Farming Group (SMFG). Fifty-one SMFG were selected from 8 counties in Chonnam province, and ownership, operation and management of farm machinery were surveyed. Annual covered area, cost and the break-even-point area of farm machinery were analyzed on the bases of the surveyed data and the present governmental subsidy policy, and then the optimum level of farm machinery ownership was determined. The results are summarized as follows: 1. The break-even-point areas of the tractors of 22-23ps, 28ps and 47-50ps were estimated as 12.1ha, 15.3ha and 21.6ha, respectively. The optimum size of a tractor for land sizes of 10-20ha, 20-30ha, and 30-40ha were estimated as 22-23ps, 28ps, and 47-50ps, respectively. 2. The break-even-point area of a rice transplanter was estimated as 3.3ha. The optimum numbers of rice transplanter for land sizes of 10-20ha, 20-30ha, and 30-40ha were estimated as 2,3, and 4, respectively. 3. The break-even-point areas of a speed sprayer (attached on power tiller) and a power sprayer were estimated as 114.6ha and 15.3ha, respectively. The optimum numbers of power sprayer for land sizes of 10-20ha, 20-30ha, and 30-40ha were estimated as 2,3 and 4, respectively. A speed sprayer is desirable for an area of more than 30ha coverage. 4. The break-even-point area of a combine was estimated as 10.7ha. The optimum numbers of combine for land sizes of 10-20ha, 20-30ha, and 30-40ha were estimated as 1,2, and 3, respectively.

• Journal of the Korean Vacuum Society
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• v.17 no.6
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• pp.528-537
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• 2008

60 nm and 20 nm thick hydrogenated amorphous silicon(a-Si:H) layers were deposited on 200 nm $SiO_2$/single-Si substrates by inductively coupled plasma chemical vapor deposition(ICP-CVD). Subsequently, 30 nm-Ni layers were deposited by an e-beam evaporator. Finally, 30 nm-Ni/(60 nm and 20 nm) a-Si:H/200 nm-$SiO_2$/single-Si structures were prepared. The prepared samples were annealed by rapid thermal annealing(RTA) from $200^{\circ}C$ to $500^{\circ}C$ in $50^{\circ}C$ increments for 40 sec. A four-point tester, high resolution X-ray diffraction(HRXRD), field emission scanning electron microscopy(FE-SEM), transmission electron microscopy(TEM), and scanning probe microscopy(SPM) were used to examine the sheet resistance, phase transformation, in-plane microstructure, cross-sectional microstructure, and surface roughness, respectively. The nickel silicide from the 60 nm a-Si:H substrate showed low sheet resistance from $400^{\circ}C$ which is compatible for low temperature processing. The nickel silicide from 20 nm a-Si:H substrate showed low resistance from $300^{\circ}C$. Through HRXRD analysis, the phase transformation occurred with silicidation temperature without a-Si:H layer thickness dependence. With the result of FE-SEM and TEM, the nickel silicides from 60 nm a-Si:H substrate showed the microstructure of 60 nm-thick silicide layers with the residual silicon regime, while the ones from 20 nm a-Si:H formed 20 nm-thick uniform silicide layers. In case of SPM, the RMS value of nickel silicide layers increased as the silicidation temperature increased. Especially, the nickel silicide from 20 nm a-Si:H substrate showed the lowest RMS value of 0.75 at $300^{\circ}C$.

• Fisheries and Aquatic Sciences
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• v.11 no.4
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• pp.183-189
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• 2008

In this study, tests were conducted to investigate the effects of three dietary growth hormones, administered in various amounts, on the growth performance and lysozyme activity in juvenile olive flounder, Paralichthys olivaceus. Three dietary growth hormones, recombinant human growth hormone (rHGH), recombinant bovine somatotropin A (rBST A) and recombinant bovine somatotropin B (rBST B) were tested at three different supplemental levels (10, 20 or 40 mg/kg body weight per week) by a $3{\times}3$ factorial design and a complete randomized design in comparison to a control group. Fish were fed one of the ten experimental diets (control, $rHGH_{10}$, $rHGH_{20}$, $rHGH_{40}$, rBST $A_{10}$, rBST $A_{20}$, rBST $A_{40}$, rBST $B_{10}$, rBST $B_{20}$ and rBST $B_{40}$) for 6 weeks and afterward were analyzed for growth performance by measuring weight gain (WG), feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER). Based on the factorial design analysis, fish fed rHGH diets demonstrated significantly higher growth performance than fish fed rBST A or rBST B diets. However there were no significant differences in WG, FE, SGR and PER between fish fed rBST A and rBST B diets. Neither hormone level nor the interaction between the different hormones and their various levels had a significant effect on WG, FE, SGR, PER, lysozyme activity or whole-body proximate composition. A complete randomized design analysis confirmed fish fed $rHGH_{10}$, $rHGH_{20}$, $rHGH_{40}$, rBST $A_{10}$, rBST $A_{20}$, rBST $A_{40}$, rBST $B_{20}$ and rBST $B_{40}$ diets for 6 weeks showed higher WG than fish fed the control diet (P<0.05). A higher FE was observed in fish fed $rHGH_{10}$, $rHGH_{20}$, $rHGH_{40}$, rBST $A_{20}$ and rBST $A_{40}$ diets in comparison to fish fed the control diet. Fish fed all graded rHGH, rBST A and rBST B supplemented diets showed a higher SGR than fish fed the control diet. Regarding PER, fish fed $rHGH_{10}$, $rHGH_{20}$, $rHGH_{40}$, rBST $A_{10}$, rBST $A_{20}$, rBST $A_{40}$ and rBST $B_{20}$ diets were higher than fish fed the control diet. Furthermore, the lysozyme activity of fish fed a diet of $rHGH_{20}$ was significantly higher than that of fish fed any other diet. The results measuring the growth and development of the fish clearly suggest the biopotency of dietary rHGH could be higher than those of both dietary rBST A and rBST B. Further implied is the probability that within the range of 10 to 40 mg/kg BW/week the dietary growth hormones could accelerate growth performance, and that 20 mg rHGH/kg BW/week could possibly enhance lysozyme activity in juvenile olive flounder, Paralichthys olivaceus.

• CELLMED
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• v.5 no.1
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• pp.5.1-5.5
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• 2015

In this first double-blind-placebo-controlled investigation of the Aeon Patch, electrocardiographic data were acquired from 50 well-hydrated volunteers [21 females and 29 males, age: 19-79, weight: 117-334 lbs, height: 5'-6',3"], under 3 different conditions for a total duration of 15 min (5 min/condition). Condition1: Control (C) - while wearing no Patch, Condition 2: Placebo (P) or Active (A) - after wearing either the Placebo or the Aeon Patch for 20 min, and Condition 3: Active (A) or Placebo (P) - after wearing either the Aeon or the Placebo Patch for 20 min. There was a washout period of 15 min between Conditions 2 and 3. All involved in the investigation were blind to the (A) and (P) Patches as they looked exactly the same and were assigned in a random fashion. The hypothesis to be tested was: Wearing the Aeon Patch for 20 min reduces stress. Data were first quality assured and those subjects who showed a parasympathetic response after wearing the Patch within 20 min were identified as early responders. Thirty subjects (60%) achieved a relaxed state after wearing the Aeon Patch as early as 20 min. Statistical analysis (one-sample inference) was used to compare the spectral features of the responders. The normalized LF/HF decreased significantly ($24%{\pm}9%$ after 20 min) in condition (A) compared to condition (P) with a p-value < 0.047 (n = 30) in responders. Therefore, the hypothesis that wearing the Aeon Patch for 20 min reduces stress was accepted as true.

• Korean Journal of Plant Resources
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• v.28 no.4
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• pp.541-545
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• 2015

This study investigated the effect of planting density on growth and yield of elephant garlic. Three planting densities of 20 × 20, 20 × 15, and 20 × 10 ㎝ were tested with the furrow width fixed at 120 ㎝ for the evaluation of elephant galic growth and yield. The average date of emergence was middle and late November, requiring about 30 days for the all emergence. For the flowering, 221 days after sowing were required in all the treatments. Plant height and leaf growth were not significantly different according to the planting density. Flower stalk was shorter when planting density was narrow. The L/D ratio was decreased to form oval shape when planting density was narrow. The yield of elephant garlic was 1,811 ㎏ /10a in planting density 20 × 20 ㎝, 2,375 ㎏/10a in 20 × 15 ㎝, and 2,838 ㎏/10a in 20 × 10 ㎝ plot. The marketable garlic ratio was highest as 1,593 ㎏/10a in planting density of 20 × 15 ㎝.

• Food Engineering Progress
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• v.14 no.3
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• pp.217-221
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• 2010

Various conditions of acetic acid fermentation by Acetobacter aceti B20 strain were investigated and evaluated to optimize the fermentative production of acetic acid. The effects of the initial ethanol concentration on growth and acid productivity in a flask and fermentor were also studied. The growth of A. aceti B20 strain was inhibited as the concentration of ethanol increased. However, the highest total acidity and fermentation yield were 5.34% and 56.1%, respectively when the initial concentration of ethanol was 7% in the batch fermentation. Although the concentration of initial glucose influenced the growth rate of B20 strain, it did not influence the total acidity in the flask culture. When the agitation speed increased, the growth, total acidity and fermentation yield were all improved. In fed-batch fermentation, total acidities and fermentation yields were 7.14-8.76% and 39.1-53.0%, respectively, and their values mostly depended on the feeding methods.

• Korean Journal of Psychosomatic Medicine
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• v.7 no.1
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• pp.42-50
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• 1999

Alexithymia refers to a specific disturbance in psychic functioning characterized by difficulties in the capacity to verbalize affect and to elabolate fantasies. Although it was initially described in the context of psychosomatic illness, alexithymic charateristics may be observed in patients with a wide range of medical and psychiatric disorders. This study was designed to investigate alexithymic characteristics in the patients with alcoholism using Scored Archetypal 9 Test(SAT9) and Toronto Alexithymia Scale-20 Korea version(TAS-20K). Twenty patients with alcoholism and twenty-four normal controls completed these tests. The results were as follows. 1) Patient group with alcoholism were significantly more alexithymic than normal control group in both SAT9 and TAS-20K. 2) No significant difference in the alexithymic measures was found between genders of both group. 3) No significant correlation was found between alexithymic measures and age or education level in both group. 4) Measures between SAT9 and TAS-20K showed significant correlation in the patient group.

• Korean Journal of Animal Reproduction
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• v.16 no.2
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• pp.133-139
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• 1992

The study was conducted to find out the changes of progesterone and 20$\alpha$-dihydroprogesterone (20$\alpha$-OHP) levels during the oestrous cycle in Korean native goats. 4 cyclic goats were offered for this experiment. Blood samples were taken from jugular vein on day 0, 1, 3, 5, 7, 9, 11, 13, 15, 17 and 19 during the oestrous cycle, then the next oestrous day. The serum levels of progesterone and 20$\alpha$-OHP were measured by radioimmunoassay. The progesterone concentration in seurm of the cyclic goats was 0.29$\pm$0.06ng/ml on the first day of oestrous (day 0), increased to 5.29$\pm$0.73ng/ml on day 9, reached to a peak level of 5.73$\pm$0.61ng/ml on day 13, and thereafter decreased to 0.35$\pm$0.30ng/ml on day 1. The serum level of 20$\alpha$-OHP during the oestrous cycle was 0.42$\pm$0.33ng/ml on day 0 and then decreased to 0.28$\pm$0.01ng/ml on day 5. This basal level was maintained until day 13, increased gradually, and reached a peak level of 0.62$\pm$0.05ng/ml on day 19. From the above results, it was suggested that the enzyme 20$\alpha$-hydroxysteroid dehydrogenase(20$\alpha$-HSD) catalyzing the conversion of progesterone to a biologically inactive steroid, 20$\alpha$-OHP, should be active in the luteal cells during the oestrous cycle in Korean native goats.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.454-457
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• 1995

To improve the yield of genuine aglycones from glycosides, the conditions of alkaline hydrolysis were investigated, and a modified method was established. The modified method empolyed pyridine as an aprotic solvent. To complete the hydrolysis and obtain 20(S)-protopanaxadiol (1) and 20(S)-protopanaxatriol(2), which are the genuine aglycones of ginsenosides, total ginsenosides were refluxed with sodium methoxide in pyridine. Addition of methanol, a protic polar solvent to the reaction miuxture, led partial hydrolysis yielding a mixture of the genuine prosapogenols. Of the prosapogenols compound 3 and 6 characteristically possessed D-glucopyranosyl moiety attached at the sterically hindered C-20 hydroxyl group. 3 and 6 were not obtaijned by other hydrolysisw methods except by the soil bacterial hydrolysis.