• Journal of the Korean Vacuum Society
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• v.1 no.3
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• pp.353-359
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• 1992

본 연구에서는 HWE 방법에 의하여 GaAs(100) 기판위에 입방정의 단결정 박막을 성장하였다. 성장된 CdS 단결정 박막의 결정구조와 방향을 ECP(electron channeling pattern)로 결정하였다. CdS 박막의 (400)면이 기판과 평행하게 성장됨을 알았다. CdS 박 막의 photoluminescence를 20K에서 측정하였는데, free exception, bound exception 및 donor-acceptor pair에 의한 발광이 관측되었다.

• Korean Journal of Medicinal Crop Science
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• v.16 no.5
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• pp.313-319
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• 2008

Scutellaria barbata was examined to evaluate its modulatory effects on the functional activation of macrophages under lipopolysaccharide (LPS) treatment. To do this, hot water extract (Sb-HWE) was prepared from Scutellaria barbata and several inflammatory parameters such as nitric oxide (NO) production, phagocytosis, reactive oxygen species (ROS) determination and intracellular signaling pathway were selected to be tested. Sb-HWE strongly blocked NO production in LPS-activated RAW264.7 cells in a dose-dependent manner. However, it did not suppress inducible NO synthase (iNOS). In agreement, Sb-HWE did not diminish inflammatory signaling composed of NF-${\kappa}B$ and its upstream activation signaling enzymes such as Akt and $I{\kappa}B{\alpha}$. Sb-HWE protected RAW264.7 cells from LPS-induced cytotoxicity up to 80% at 400\;{\mu}g/ml$. Furthermore, this extract blocked phagocytic uptake of FITC-dextran, while sodium nitroprusside (SNP)-induced ROS generation in RAW264.7 cells was not decreased. Therefore, our data suggest that Sb-HWE may have differential immunoregulatory function depending on macrophage-mediated immune responses.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.68-74
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• 2014

Scientific study has investigated the body condition differences by habitat characteristics in larvae Korea salamander (Hynobius leechii) from March to April in 2012. To examine the sensitivity of external environment (predation risk), we divided two groups according to habitat characteristic; 1) Permanent pond and 2) Temporary pond. Howere, each larva was measured by head width at the level of the eye (HWE), largest head width (LHW) and snout-vent length, and we calculated the ratio of the head size by dividing HWE/LHW. As a result, larvae were larger in permanent pond group, had a faster growth rate than in temporary pond group. When exposed to the predator, larvae in permanent pond were smaller HWE/LHW than larvae in permanent pond. Therefore, these results indicate larvae in temporary pond more sensitive to the external environment.

• Journal of Wetlands Research
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• v.15 no.4
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• pp.485-491
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• 2013

This study examined the cannibalistic polyphenism of larval salamander Hynobius leechii by the level of predation risk. Salamander eggs were collected from three regions (Mountain Inwang, Mountain Surak and Gwangju). Eggs were treated by three different risk conditions: (1) high risk, predation risk three times a day; (2) medium risk, predation risk once a day; and (3) low risk, no predation risk. Predation risk was conducted using a chemical cue from Chinese minnows. The chemical cue treatment started from the day of collection and ended one week after hatching. Post-treatment measurements were head width at the level of the eyes (HWE), largest head width (LHW), and Snout-vent length of the each larva. To compare the morphological change according to the predation risk, we modified the two head size, HWE and LHW, to HWE/LHW. A significant difference in HWE/LHW and snout-vent length was evident according to the level of predation risk. And larval mortality was increase by the predation risk. The results indicate that predation risk can cause cannibalistic polyphenism of larval salamander and this morphological change could influence larval mortality.

• Food Science and Preservation
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• v.17 no.6
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• pp.861-866
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• 2010

We obtained hot-water extracts (HWE) and 70% (v/v) ethanol extracts (EE) from cultured wild ginseng roots (CWGR) and determined the saponin and total polyphenol contents, and antioxidant activities. The yields of freeze-dried powder from the HWE and EE were 27.86% and 18.33% (both w/w), respectively. The total polyphenol content of the EE (22.63 mg/g) was higher than that of the HWE (17.90 mg/g). Ginsenoside-Rb1 and -Rg1 contents of hot-air-dried CWGR were 17.90 mg/g and 22.63 mg/g, respectively. The electron-donating ability of HWE and EE were 2.82-60.58% and 3.88?70.88%, respectively, and the reducing powers ($OD_{700}$) were 0.02-0.17 and 0.07-1.90, respectively, at concentrations of 1-20 mg/mL. Thus, the HWE reducing power was markedly lower than that of the EE, but the SOD-like activity of the EE was significantly higher than that of the HWE. The nitrite-scavenging activities of HWE and EE were 9.25-19.18% and 11.94-53.49%, respectively, at concentrations of 1-20 mg/mL. Additionally, the TBARS (Thiobarbituric acid reactive substances, % value) of the EE (1-20 mg/mL) was 9.18-66.59%, thus 1.9-2.8-fold greater than that of the HWE (4.74-24.88%). In conclusion, we provide experimental evidence that extracts of CWGR may be natural antioxidants.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.96-113
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• 2016

The observation of the classic plant name 'Hwe', that is to be discussed in this thesis, must be primarily conducted in folk plant research made through old documents. Diverse information such as the characteristics, method of use, and distribution of plants is scattered in old documents. However, reviews of classic plant names should be made to use such information. This is because information on plants can only be used after thorough verifications are made of the plant names. 'Hwe' is interpreted as various meanings in Korea but it is mostly used to mean fir, old pine tree, and cypress. However, it is not known by what standards such interpretations have been made. In particular, 'Hwe' is interpreted at the discretion of the translator in classic translations, so direct quotations from these lead to further errors. Therefore, items in classic plant names must be reviewed again. Why is 'Hwe' interpreted in various ways as a plant name and according to what standards should it be interpreted? This study was conducted with these questions. Also, the significance of this study is placed in the setting of guidelines for the interpretation of 'Hwe' so that classic plant names can be properly interpreted and information on plants can be accurately secured.

• Journal of Life Science
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• v.29 no.1
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• pp.52-59
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• 2019

The leave of Polygonum tinctorium (LPT) have been used for centuries as a traditional medicine and as a food ingredient and natural dye. The aim of the current study was to develop high-value added products using LPT. Hot water extract (HWE) and ethanol extract (EE) of LPT were prepared, respectively, and their bioactivity was evaluated. The extraction ratio for the HWE was 27.6%, which was two-fold higher than that of the EE. The contents of total polyphenol in the HWE and total sugar in the EE were 51.2 mg/g and 297.8 mg/g, respectively. The total flavonoid and reducing sugar contents were similar in the extracts, irrespective of the extraction solvent. The HWE did not show antimicrobial activity in a disc-diffusion assay, but the EE showed strong growth inhibition against gram-positive bacteria. The EE exhibited stronger DPPH and ABTS radical scavenging activities and reducing power than those of the HWE. The HWE was particularly effective as a scavenger of nitrite ($RC_{50}$ of $6.0{\mu}g/ml$). In an antithrombosis activity assay, the EE showed significant anticoagulation activity as determined by an extended blood coagulation time (thrombin time, prothrombin time, and activated partial thromboplastin time), in addition to platelet aggregation activity. The HWE also showed platelet aggregation inhibitory activity. This report provides the first evidence of antithrombosis activities of LPT. Our results suggest that LPT has potential as a new antioxidant and antithrombosis agent.

• Journal of Life Science
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• v.31 no.2
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• pp.183-191
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• 2021

Euglena gracilis is a microalga of great biotechnological interest that can create high levels of bioactive compounds, such as tocopherol, paramylon, and folic acid. The objective of this study was to investigate the biological activities of extracts from E. gracilis, especially those focused on immunological activity. E. gracilis biomass was extracted with hot water (HWE) and the remaining pellet was continuously extracted with methanol (HWME). First, we examined the effect of two extracts from E. gracilis on the production of nitric oxide (NO) and the expression of pro-inflammation cytokines, including IL-1β, IL-6, and TNF-α in murine macrophage RAW 264.7 cells. HWE treatment dose-dependently increased the production of IL-1β and TNF-α. On the other hand, treatment with HWME significantly decreased the generation of NO and pro-inflammatory cytokines (IL-6 and TNF-α) in lipopolysaccharide (LPS)-stimulated macrophage cells. In addition, other biological activities of the extracts were further analyzed: α-glucosidase inhibition, protein tyrosine phosphatase (PTP1B) inhibition, tyrosinase inhibition, xanthine oxidase (XO) inhibition, and angiotensin-converting enzyme (ACE) inhibition. Analysis of these biological activities showed that HWE has more inhibitory effects than HWME against α-glucosidase, tyrosinase, and XO agents. However, the inhibition of PTP1B and ACE with HWME were higher than with HWE. Taken together, the results suggested that E. gracilis possesses various biological activities―especially immunological capabilities―through regulation of cytokine production. Therefore, E. gracilis extract may be potentially useful for food material with immune-regulating effects.

• Biomedical Science Letters
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• v.10 no.1
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• pp.9-13
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• 2004

We have investigated the effects of hypha-water extracts (HWE), fruit body-water extracts (FWE) and cordycepin from Cordyceps militaris on serotonin release out of human platelets and human platelet aggregation. HWE and FWE inhibited the release of [$^3H$]-serotonin from human platelet stimulated by thrombin (2 U/ml) or collagen (20$\mu$g/ml) in a dose-dependent manner. Furthermore, cordycepin, a major component of Cordyceps militaris, inhibited the human platelet aggregation induced by collagen (10$\mu$g/ml) in a dose-dependent manner. These results suggest that cordycepin containing in HWE and FWE may inhibit the serotonin release by suppressing the collagen-induced human platelet aggregation. Accordingly, our data demonstrate that HWE and FWE containing much cordycepin might have antithrombotic and antimigrainous functions.

• Journal of Environmental Health Sciences
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• v.37 no.5
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• pp.342-347
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• 2011

Healthy worker effect (HWE) refers to the consistent tendency for actively employed individuals to have a more favorable mortality experience than the population at large. Although HWE has been well known since the 1970s, only a few studies in occupational epidemiology have attempted to fully define and evaluate HWE. HWE can be separated into effects on the initial hiring into the workforce (healthy worker hire effect) and those on continuing employment (healthy worker survival effect). In this review, we summarize the methods for minimizingor adjusting for the healthy worker effect available in occupational epidemiology. It is noteworthy that healthy worker survival effect appears complicated, considering that employment status plays simultaneous roles as a counfounding variable and intermediate variable, whereas healthy worker hire effect may be adjusted by incorporating health status at baseline into the statistical model. In addition, two retrospective cohort studies for workers in the semiconductor industry and Vietnam veterans in Korea, respectively, were introduced, and their results were explained in terms of healthy worker effect.