• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.183-193
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• 2022

The growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was evaluated using a large algae sample volume (10 L) for various ultrasonic irradiation times (0.5, 1, 1.5, 2, 2.5 and 3 hr) at a laboratory scale. Based on the analysis of Chl-a and cell number of M. aerginosa, algae growth inhibition was observed with the decrease in Chl-a and cell number in all experimental groups after the ultrasonic irradiation. For the experimental group (T_B, T_C, T_D) with an ultrasonic irradiation time of less than 2 hours, rapid regrowth of algae was observed after growth inhibition, but the experimental group (T_E, T_F, T_G) with an irradiation time of more than 2 hours successfully inhibited algal growth lasting one or two more days. Based on the comparison of the recovery time to initial cell number the experimental group (T_B, T_C, T_D) took less than 20 days whereas the experimental group (T_E, T_F, T_G) took about 30 days. Correspondingly, the experimental group showed a high first order decay rate (𝜅) in proportion to the ultrasonic irradiation time during the growth inhibition period. Additionally, the specific growth rates (𝜇) during regrowth in the experimental group with irradiation time of more than 2 hours were relatively low compared to those in the experimental group with less than 2 hours. Therefore, ultrasonic irradiation for more than 2 hours is required for long-term (30 days) inhibition of algal growth in stagnant waters. However, the appropriate ultrasonic irradiation time for algae growth inhibition should be determined according to various field conditions such as the volume of stagnant water, water depth, flow rate, algae concentration, etc. Finally, damages to the algal cell surface and cell membrane were clearly observed, and both destruction and disturbance of gas vesicles of M. aeruginosa in the experimental group were discovered, indicating the growth inhibitory effect of Microcystis aeruginosa according to the ultrasonic irradiation time was confirmed.

• Economic and Environmental Geology
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• v.55 no.5
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• pp.531-540
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• 2022

Various iron minerals that precipitate in acid mine drainage have a great influence on the concentration change and mobility of trace elements in the drainage during phase transition to other minerals as well as the precipitation process. This study investigated the change of mineral properties and the behaviors of trace elements influenced by pH and time for the precipitates collected from the acid mine drainage treatment system of the Dalsung mine, where schwertmannite is mainly precipitated. However, the main mineral precipitated in the drainage was goethite, suggesting schwetmannite has already undergone a phase transition to goethite to some extent, and it was observed that at higher pH, the peak width at half maximum of XRD peak was narrower. This can be interpreted as the transformation of small amount of amorphous schwetmannite to goethite or an increase in the crystallinity of goethite, and it showed that the higher the pH, the greater this change was. The concentration of Fe was also greatly affected by the pH values, and as the pH increased, the concentration of Fe in the drainage decreased. With increasing time, the Fe concentration increased and then decreased, which can be interpreted to indicate the dissolution of schwertmannite and precipitation of goethite. This mineral change probably resulted in the rapid increase of the concentration of S at initial stage, but its concentration was stabilized later. The concentration of S is also related to the stability of schwetmannite, showing a high concentration at a low pH at which schwertmannite is stable and a low concentration at a high pH at which goethite is stable. The trace elements present as cations in the drainage also showed a close relationship with the pH, generally the lower the pH, the higher the concentration, due to the solubility changes by the pH, and the precipitation and the changes in mineral surface charge at high pH. On the other hand, in the case of As, existing as an anion, although it showed a high concentration at low pH, its concentration increased with time at all pH values, which is probably related to the concentration of Fe which can be coprecipitated in the drainage, and the increase of As concentration with time is also considered to be related to the decrease in schwertmannite rather than the mineral surface charge.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.721-734
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• 2022

This study analyzed the spatio-temporal variation characteristics of major environmental factors such as primary productivity (PP), chlorophyll a, nutrients, sinking particle matters, and organic contamination and biochemical composition of surface sediment on a monthly basis for approximately 2 years around shellfish mariculture in Jaran Bay, Korea. In addition, PP in Jaran Bay was compared with that in other coastal areas and related policy plans were proposed. The average PP of the study area was high in summer and autumn with 6.43~115.43 mgC m^-2 hr^-1 range. This was lower than that in Gamak Bay and Masan Bay, whereas higher than that in Garorim Bay and the West Sea. The PP in coastal waters, where many aquaculture farms were distributed, significantly fluctuated. The different size compositions of phytoplanktons constituting chlorophyll a slightly varied by month, and little restriction existed on the productivity of phytoplanktons owing to the depletion of nutrients. Typically, the Redfield ratio was less than 16, indicating that nitrogen was the limiting factor for the growth of phytoplanktons. The biochemical composition of particulate organic matters in the water column showed the highest carbohydrates, but lipids and protein contents were high in surface sediments. The concentration of TOC and AVS of the surface sediments was high at inside of bay, and sometimes, exceeded the environmental criteria of fishing grounds. The organic C:N ratio of sediments ranged from 8.1 to 10.4 on average. PP had the highest correlation with chlorophyll a, nitrogen and protein of particle organic materials. Recently, chlorophyll a, DIN, and DIP of water column trends tended to decrease, however, the contamination of sediments increased. Considering the annual PP of 125.9 gC m^-2 yr^-1 and mariculture area (oyster) of 4.97 km², the annual carbon production from phytoplanktons was estimated to be about 625 tons, and the annual total wet weight of shellfish (oyster) was estimated to be about 6,250 tons.

• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.417-427
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• 2022

In this study, we investigated in vitro immuno-stimulatory and anti-obesity activity of fruit (LIF), leaves (LIL) and stems (LIS) from Lonicera insularis Nakai in mouse macrophages RAW264.7 cells and mouse pre-adipocytes 3T3-L1 cells. LIF, LIL and LIS increased the production of immunostimulatory factors such as nitric oxide (NO), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α) and activated phagocytosis in RAW264.7 cells. Inhibition of toll-like receptor 2/4 (TLR2/4) partly blocked LIF, LIL and LIS mediated production of immunostimulatory factors. In addition, inhibition of mitogen-activated protein kinases (MAPK) signaling attenuated the production of immunostimulatory factors induced by LIF, LIL and LIS. Based on these results of this study, LIF, LIL and LIS is thought to activate macrophages the production of immunostimulatory factors and phagocytosis through toll-like receptor 2/4 (TLR2/4) and MAPKs signaling pathway. In anti-obesity study, LIF reduced the lipid accumulation in 3T3-L1 cells. LIF increased the protein phosphorylation expressions such as AMP-activated protein kinase (AMPK), hormone sensitive lipase (HSL), adipose triglyceride lipase (ATGL) related to the lipolysis of the adipocytes. In addition, LIF increased the expression of proteins involved in energy metabolism and brown adipose tissues differentiation such as peroxisome proliferator-activated receptor gamma coativator 1α (PGC-1α) and PR domain-containing16 (PRDM16). These results suggest that LIF is involved in lipid accumulation inhibition through expressing the proteins such as lipolysis and differentiation of white adipocytes to brown adipocytes.

• Journal of Wetlands Research
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• v.24 no.3
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• pp.185-195
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• 2022

This study conducted a survey over spring and autumn from 2014 to 2020 to confirm the ecological characteristics of the size of streams and habitats, centering on the ecological landscape conservation area, and a total 256 species of benthic macroinvertebrates in 105 families, 25 orders, 8 classes, and 5 phyla appeared. In terms of appearance species, by region, the rate of appearance of Ephemeroptera and Trichoptera was high in regions consisting of lotic area and the rate of appearance of Coleoptera and Odonata was high in regions consisting of lentic areas. When comparing the population of Ephemeroptera-Plecoptera-Trichoptera (EPT) groups by region, they were classified into three groups: upstream area, mainstream area, and lentic areas, and it was confirmed that the population ratio of EPT changed as it moved from upstream to downstream. As the stream order increased, the number of species and populations increased. The Shredder group (SH) tended to decrease as the size of stream increased(r=0.9925), and the Collector-Filtering (CF) tended to increase as the size of stream increased(r=0.9319). It was confirmed that the Scraper (SC) replaced each other between species with the same ecological status as it went downstream from upstream, and it is thought that the SC did not differ significantly by stream order. In order to maintain a healthy ecosystem in the designation and management of ecological landscape conservation areas, it is necessary to consider ecological factors such as competition and physico-chemistry factors such as water quality and substrate conditions. Therefore, if the competent authority designated survey areas including buffer areas that include streams and physical habitats of various sizes, it will be advantageous to the conservative area and securing more biological resources.

• Journal of Food Hygiene and Safety
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• v.37 no.4
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• pp.260-270
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• 2022

In this study, we tested for pesticide residues in 114 samples representing 20 different types of fruit circulating in Gyeonggido. A total of 341 pesticides were identified via a multi-residue method using GC-NPD, GC-ECD, GC-MSMS, and LC-MSMS. In whole fruit, pesticides were detected in 48 cases, with a concentration range of 0.0025-0.1663 mg/kg. In the peels, pesticides were detected in 85 cases, with a concentration range of 0.0026-4.7185 mg/kg and a higher average concentration than was found in whole fruit. In the pulp, pesticides were detected in 8 cases, with a concentration range of 0.0021-0.0993 mg/kg. In most of the peels, pesticides were detected below MRL. In the kiwi peel, deltamethrin (with an MRL of 0.05 mg/kg) was detected at 0.1020 mg/kg. Since MRLs are applied to whole fruit, these levels are not unsuitable for ingestion. However, washing is recommended before ingestion to promote healthier and safer inclusion of the peel in the diet. Continuous monitoring of the peel and pulp is indicated.

• Journal of Life Science
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• v.32 no.8
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• pp.622-632
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• 2022

The purpose of this study was to investigate activities as functional cosmetic materials, focusing on Rhododendron brachycarpum (RB) and Rhododendron fortunei (RF). The tyrosinase inhibitory effect, related to skin-whitening, was 32.6% and 39.3% respectively at the concentration of 1,000 ㎍/ml. The elastase inhibitory effect, related to skin anti-wrinkling activity, was 30% and 36.2% at 1,000 ㎍/ml concentration. Collagenase inhibitory activity showed 77.7%, and 80.2% respectively at 1,000 ㎍/ml concentration, which demonstrated excellent inhibitory activity. For a cell viability test, that measured on fibroblast cells by RB and RF extracts. Furthermore, the cell viability test showed 100.9% and 98.9% with cell viability at 100 ㎍/ml concentration in CCD-986Sk. The protein expression inhibitory effect of RB and RF extracts was measured by western blot at 25, 50, and 100 ㎍/ml concentrations, and the β-actin was used as a positive control. As a result, western blot of RB and RF extracts was measured by the expression inhibition rate of the MMP-1, MMP-2, MMP-3 protein, and was decreased by 67.2%, 65.5%, 13.6%, and 89.1%, 85.0%, and 62.7% at 100 ㎍/ml concentration. The mRNA expression inhibitory effect of RB and RF extracts was measured by RT-PCR at 25, 50, and 100 ㎍/ml concentrations, and the GAPDH was used as a positive control. According to the results of RT-PCR of RB and RF extracts, the expression inhibition rate of the MMP-1, MMP-2, and MMP-3 mRNA was decreased by 70.1%, 9.1%, 37.9%, and 38.2%, 8.3%, 57.3% at 100 ㎍/ml concentrations. So, RB and RF extracts showed the anti-wrinkle effectiveness as a functional cosmetic material.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.143-148
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• 2022

This study was to investigate an analytical method for determining dieckol content in Ecklonia stolonifera extract. According to the guidelines of International Conference on Harmonization. Method validation was performed by measuring the specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) of dieckol using high-performance liquid chromatography-photodiode array. The results showed that the correlation coefficient of calibration curve (R²) for dieckol was 0.9997. The LOD and LOQ for dieckol were 0.18 and 0.56 ㎍/mL, respectively. The intra- and inter-day precision values of dieckol were approximately 1.58-4.39% and 1.37-4.64%, respectively. Moreover, intra- and inter-day accuracies of dieckol were approximately 96.91-102.33% and 98.41-105.71%, respectively. Thus, we successfully validated the analytical method for estimating dieckol content in E. stolonifera extract.

• Journal of Food Hygiene and Safety
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• v.37 no.4
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• pp.225-231
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• 2022

In this study, the conditions of dry heat treatment (21 days at 65℃, 16 days at 70℃, 10 days at 75℃, and 7 days at 80℃) were investigated to inactivate Bacillus cereus ATCC 12480, Listeria monocytogenes ATCC SSA81, Staphylococcus aureus ATCC 6538, Escherichia coli O157:H7 ATCC 43894, and Salmonella Typhimurium ATCC 14028 on alfalfa seeds, without affecting the rate of germination of seeds. Alfalfa seeds were inoculated at levels of 6-7 log CFU/g and treated with dry heat at 65℃, 70℃, 75℃, and 80℃; thereafter, the rate of seed germination was determined. The rate of germination was set at 70%, according to the market standards. The bacteria were inactivated when B. cereus was treated with dry heat for 21 days at 65℃, 18 days at 70℃, 14 days at 75℃, and 4 days at 80℃; L. monocytogenes was treated for 21 days at 65℃, 18 days at 70℃, 12 days at 75℃, and 7 days at 80℃; S. aureus was treated for 18 days at 65℃, 18 days at 70℃, 11 days at 75℃, and 4 days at 80℃; E. coli O157:H7 was treated for 21 days at 65℃, 18 days at 70℃, 12 days at 75℃, and 6 days at 80℃; and Sal. Typhimurium was treated for 24 days at 65℃, 22 days at 70℃, 14 days at 75℃, and 7 days at 80℃. For all bacteria, the D-value (R² = 0.5656-0.7957) significantly decreased when the temperature increased from 65℃ to 80℃ (P<0.05). Since dry heat treatment of alfalfa seeds at 80℃ for 7 days affects their germination rate, dry heat treatment at 75℃ for 14 days is the most effective way to ensure their safety. This study suggests a potential method of bacterial inactivation using dry heat treatment to increase the microbiological safety of sprouts.

• Journal of agricultural medicine and community health
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• v.47 no.2
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• pp.67-77
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• 2022

Objective: This study was to evaluate the effectiveness of an individually tailored program based on self-measurement of blood glucose on health behavior and HbA1c in diabetes and pre-diabetes patients. Methods: The program consisted of seven sessions for 12 weeks which were carried out every two weeks. Almost all sessions were progressed on untact method except for the first and last session. The 71 subjects were assessed for their knowledge of diabetes, health behavior, the experience of self-measurement of blood glucose, body mass Index (BMI) and hemoglobin A1c (HbA1c) at before and after the program. They were also evaluated on their degree of utilization of blood glucose measurements after the program. Results: Each mean score on their knowledge of diabetes, health behavior and the experience of self-measurement of blood glucose was significantly increased from 14.77, 25.50, and 2.70 to 15.41, 28.40, and 4.81, respectively. Each mean score on both BMI and HbA1c (n=53) was significantly decreased from 24.47kg/m² and 7.27% to 24.01kg/m² and 6.67%, respectively. The post-HbA1c had a significant negative correlation(r=-0.415) with the degree of utilization of blood glucose measurements. The degree of utilization of blood glucose measurements had a significant positive correlation(r=0.581) with post-health behavior. Conclusions: The program shows effectiveness in improving HbA1c in Type 2 diabetes and pre-diabetes patients. The post-HbA1c might be related to the degree of utilization of blood glucose measurements which might be related to the health behavior.