본 연구는 고등학생의 자아존중감, 분노표현, SNS중독경향성의 정도 및 그들 변수 간의 관계와 SNS중독경향성에 미치는 영향 요인을 알아보고자 하는 서술적 조사연구이다. 대상자는 2020년 5월 18일~28일까지 총 10일 간 S시, G도 고등학교에 재학 중이며 SNS을 이용하고 있는 대상자에게 온라인 설문지를 이용하여 총 100부의 자료를 수집하였다. 연구결과, SNS중독경향성과 자아존중감(r=-.385, p<.001), 분노조절(r=-.354, p<.001)과는 보통의 역 상관관계, 분노표출(r=.321, p=.001), 분노억압(r=.308, p=.002)과는 보통의 순 상관관계를 나타냈다. SNS중독경향성에 미치는 영향 요인은 자아존중감(β =-.297, p=.001), 성별(β=.266, p=.003), 분노표출(β=.247, p=.007) 순으로 회귀모형의 설명력은 27.7% 로 나타났다(F=12.279, p<.001). 따라서 SNS중독경향성을 낮추기 위해 고등학생의 자아존중감을 높이고 분노표출을 낮추기 위한 프로그램 개발이 필요하며 특히 성별에서 여자 고등학생의 SNS중독경향성을 낮추기 위한 방안이 모색되어야 할 것이다.

This study examined the antioxidative and lipid accumulation inhibitory effects of 14 plants from Mongolia and Myanmar on 3T3-L1 and HepG2 cells. The total phenolic and flavonoid contents (TPC and TFC) of 14 plant extracts were measured, and the antioxidative activities were analyzed using DPPH, ABTS, FRAP, and ORAC. After measuring the pancreatic lipase levels and performing the thiobarbituric acid assay, the degree of lipid accumulation was determined by lipid (Oil Red O) staining and triglyceride assay in 3T3-L1 and HepG2 cells. M. paniculate (259.43 mgGAE/g) and C. benghalensis (130.78 mgNAE/g) had the highest TPC and TFC, respectively, among the 14 plants. R. acicularis Lindl. had the highest antioxidant activity in DPPH. The ABTS, FRAP, and ORAC results showed that the antioxidant activity of 11 species was higher than that of the positive control. The pancreatic lipase inhibitory effect of C. angustifolium Scop. was reduced to 23.65% at 0.1 mg/mL, and the level of lipid peroxidation of C. abrorescens Lam. was 0.63 nmol/mg. Five selected plants inhibited the lipid accumulation and triglyceride content, respectively, in 3T3-L1 and HepG2 cells. These results provide scientific evidence for developing functional foods using 14 plants from Mongolia and Myanmar, which have antioxidant activities and lipid accumulation reduction effects.

In this study, 11 plant extracts from Bangladesh were used to evaluate the total phenolic and flavonoid content, in vitro antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzthiazolin-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assay. Also, the inhibitory effect of nitric oxide (NO) production in RAW 264.7 macrophage cell line and the neuroprotective effect on H2O2-induced PC12 cells were tested. Our results revealed that Piper betle L. showed the highest total phenolic content (162.2 mg GAE/g extract) among the 11 plants from Bangladesh. Most plants showed strong radical scavenging effects and ferric reducing antioxidant power. Besides, Piper betle L. protected PC12 neuronal cells against H2O2 related oxidative stress in LPS-induced PC12 cells. Regarding the antiinflammatory effect, Piper betle L. significantly inhibited NO accumulation in LPS-induced RAW 264.7 cells. Our results provide evidence that Piper betle L. could be useful for the development of functional health foods.

In this study, we examined antioxidative effects and the anti-adipogenesis effect of different parts of Cudrania tricuspidata (C), and Morus alba (M). Total polyphenol contents were highest in M-root (34.56±0.045 mg GAE/g), and there was no significant difference, between C-root and M-leaf. Total flavonoid contents of C-root were highest (23.07±0.004 mg QE/g). To examine antioxidant activities of C and M extracts, DPPH and ABTS radical scavenging activity, and FRAP assay, was used. Results show that antioxidant activities of C and M extracts increased, in a dose-dependent manner. Adipocytes are generated by preadipocyte differentiation, during adipogenesis. Matured adipocytes accumulate in abnormal and cause obesity. We investigated effects of leaf and root extracts of C and M, on lipid accumulation, in 3T3-L1 adipocytes. Changes in cell morphology, and degrees of lipid accumulation in adipocytes, were evaluated by Oil Red O staining. Root extracts of C and M, reduced lipid content in a dose-dependent manner. Therefore, root extracts of C and M, may be good candidates for managing obesity.

The objective of this study was to evaluate novel usability as natural anti-obesity supplement of Selaginella tamariscina extract. The total phenol contents and total flavonoid contents were 60.29±3.11 GAE mg/g and 14.90±0.34 QE mg/g, respectively. To evaluate anti-obesity activity of Selaginella tamariscina extract, pancreatic lipase inhibition activity as well as its inhibition effect of lipid accumulation in adipocytes were conducted by Oil Red O staining and lipolysis assay. The result of pancreatic lipase inhibition activity of S. tamariscina extract showed a wide range between 40 and 73% dose dependently. While the incubation of 3T3-L1 cells with S. tamariscina extract inhibited differentiation of preadipocytes and reduced lipid accumulation, the level of released free glycerol into culturing medium was increased in multiple concentrations. These results showed that S. tamariscina extract inhibit adipogenesis and pancreatic lipase activity. Thus, S. tamariscina extract can be a candidate for regulating lipid accumulation in obesity.

Additive manufacturing by electron beam melting is an affordable process for fabricating near net shaped parts of titanium and its alloys. 3D additive-manufactured parts have various kinds of voids, lack of fusion, etc., and they may affect crack initiation and propagation. Post process is necessary to eliminate or minimize these defects. Hot isostatic pressing (HIP) is the main method, which is expensive. The objective of this paper is to achieve an optimum and simple post heat treatment process without the HIP process. Various post heat treatments are conducted for the 3Dprinted Ti-6Al-4V specimen below and above the beta transus temperature (996oC). The as-fabricated EBM Ti-6Al-4V alloy has an α‘-martensite structure and transforms into the α+β duplex phase during the post heat treatment. The fatigue strength of the as-fabricated specimen is 400 MPa. The post heat treatment at 1000oC/30 min/AC increases the fatigue strength to 420 MPa. By post heat treatment, the interior pore size and the pore volume fraction are reduced and this can increase the fatigue limit.

This study was designed to evaluate the antioxidant activities and protective effects on PC12 cells of the extract of Epimedium koreanum and its main constituents icariin and icariside I. After screening the seven identified flavonoid glycosides from E. koreanum through DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay, E. koreanum, Icariin and Icariside I exhibited significant effect on radical scavenging activity. E. koreanum, icariin and icariside I were examined using DPPH, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) and FRAP (ferric reducing ability power) assay. In all antioxidant assays, E. koreanum, icariin and icariside I showed high radical scavenging activities in a dose-dependent manner. Protective effects against H2O2-induced PC12 cells were assessed with MTT assay. The results indicated that cell viability and protection on PC12 cells of icariside I and icariin increased dose dependently. These study results suggest that E. koreanum, icariin and icariside showed high antioxidant capacities and cell protective effects. Icariside I, one of the metabolites of icariin, may be a new and effective flavonoid compound as a functional component.

Nutrition labeling can provide information in order for people to select products suitable for their own health, and sodium content labeling for processed foods is important since sodium is one of the main causes of cardiac diseases. This study had carried out to propose the desirable sodium content labeling by conducting surveys on the awareness of sodium content in processed foods, understanding of sodium content labeling, and requirements for new sodium comparative claims. The survey period was from 12th of September, 2016 through the 24th, during which a self-administered questionnaire survey was given to 1,003 persons through demographic quota sampling by age and region. As a result of the survey, 66.0% of respondents assuring nutrition labeling answered they check sodium content labeling, whereas 83.2% were aware of excessive intake of sodium having a negative effect on health. Exactly 49.9% of respondents answered that the current system for nutrition labeling on processed foods does not help one to understand the content of sodium, whereas 72.9% answered they wanted to compare sodium contents with those of other products when buying or taking processed foods. As 92.5% cited the importance of sodium comparative claims made by processed foods, preparation of a new system for food labeling should be considered by which consumers can easily compare sodium contents with those of other similar products.

This study attempted to establish the optimal conditions for storage of spring kimchi cabbage to stably control supply and demand. To this end, this study stored kimchi cabbages in various manners for different periods and compared the quality characteristics of kimchi using these cabbages. According to the results, pre-drying with photocatalytic and pre-cooling treatments showed average selectivity loss rates of 18.83 and 21.37%, respectively, which were lower than those of other treatments. Spring kimchi cabbages were stored for 15 weeks under various conditions, and the kimchi was stored for 4 weeks at 4°C. After ripening, each kimchi was analyzed for their soluble solid content, pH, acidity, and salinity. The average pH of kimchi was 4.60 and tended to rise, whereas average acidity was 0.38% and fell by 0.24 to 0.31% as the storage period was extended. Extension of the storage period caused decreases in soluble solid content and salinity, and the number of lactic acid bacteria decreased due to increased pH and reduced acidity (p<0.05). Sensory evaluation showed that all experts and non-professionals preferred kimchi treated by precooling compared to any other treatment.

To stabilize the supply of kimchi by extending the storage period of spring kimchi cabbage, this study manufactured kimchi from spring kimchi cabbage under varying storage conditions and periods, and analyzed their quality and sensory characteristics following the maturing period. Trimming loss was lowest in the group of plasma+reverse direction+predrying+ HDPE film processing. The salting yield of spring kimchi cabbage stored for 12 weeks was lower than that of spring kimchi cabbage stored for 6 weeks, and the kimchi yield was low in the pre-treatment group of spring kimchi cabbage stored for 12 weeks. The firmness was slightly different according to the storage period from one month of maturation. From the perspective of pH and acidity, the maturation in the reverse direction+pre-drying+HDPE film processing group was slower than that in the normal group (<0.05). In the sensory evaluation, the preference was increased in the low temperature storage processing group as the maturation period was increased (<0.05).

This study was designed to investigate the contents of icariin during ripening of Epimedium koreanum with sugar and Soju (25, 30, and 35% alcohol contents) using a homemade method. Contents of icariin of Epimedium wine were examined using high performance liquid chromatography. Icariin levels in Epimedium wine increased during the first 3 days of storage; after 6 days, icariin contents decreased gradually until 30 days. Contents of icariin in Epimedium wine by storage temperature (5 and 20°C) were not different during storage. After 30 days, icaiin was not detected in all tested Epimedium wines. Epimedium wines were assessed for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azinobis( 3-ethylbenzothiazoline-6-sulfonic acid) and (ABTS) radical scavenging activity. DPPH and ABTS radical scavenging activities increased in early storage periods, however, after 6 or 9 days, activities decreased gradually.

본 연구는 월동배추를 주로 이용하는 한국인의 전통적인 김장방법으로 인한 김장철 배추가격 급등락의 문제해결에 기 여하고자 상대적으로 사용도가 낮은 봄배추를 이용한 김치 의 저장기간 연장과 품질유지를 목적으로 수행되었다. 실험 결과, 경도는 수확시기가 가장 늦은 7월초 김치가 6월 중순 김치보다 유의적으로 높았으나(p<0.01) 숙성이 진행됨에 따 라 저장 8주차에는 수확시기에 따른 유의적인 차이를 보이 지 않았다. 김치 숙성과 상관성이 높은 pH와 산도 측정결과 전반적으로 저장 초기에 비해 pH는 감소하였고, 산도는 증 가하는 경향을 나타내었다. 관능평가 결과, 외관은 김치의 제 조시기와 숙성기를 종합하여 6월말 제조 김치의 외관이 가 장 우수하였고(p<0.05), 저장 4주차와 8주차에는 7월초 김치 가 가장 우수한 것으로 평가되었으나 유의적인 차이는 없었 다. 조직감 및 전반적인 기호도 항목에 있어서도 처리구별 유의적인 차이는 보이지 않았다. 따라서 수확시기에 차이를 둔 봄배추로 김치 제조 시 생배추 상태 또는 제조직후의 차이에 비해 절임과 숙성과정, 양념의 첨가 등을 통해 그 유의 적 차이가 감소됨에 따라 수확시기가 봄배추로 제조된 김치 품질에 미치는 영향은 크지 않음을 확인할 수 있었다. 다만, 수확시기가 가장 늦은 배추로 제조된 김치의 경우 생배추 상 태에서 경도가 유의적으로 높았으며 숙성기간 및 저장기간 이 연장되었으므로 이를 수확시기나 작황사정과 연결하여 차 후 심화된 연구가 필요할 것으로 사료된다.

Consumers have recently shown great interest in organic foods since they are considered to have higher antioxidant activity compared to conventionally farmed foods. The purpose of this study was to evaluate the general characteristics of organic and conventional spinach, such as length, weight, color, moisture contents, and antioxidant capacity based on ABTS radical scavenging activity, total phenol, and flavonoid contents. Spinach that was used in this study was grown conventionally and organically in Po-Hang, Korea. As the results, conventional spinach showed higher values for length, weight (p<0.001), and moisture content (p<0.05). For antioxidant capacity, organically grown spinach showed higher antioxidant activity than the conventional group based on total phenol and flavonoid contents, but only total flavonoid content was significantly different (p<0.05). For ABTS radical scavenging activity, the conventional group showed a slightly higher capacity, but the difference was not significant. Thus, the organic farming system in spinach showed similar or slightly higher antioxidant activities.

Demand for organic agriculture has greatly increased in the past decade. The objective of this study was to evaluate quality the characteristics and antioxidant activities of organically and conventionally grown carrots. Organically and conventionally grown carrots were harvested in Jeju Island, Korea. Carrot extracts were investigated for their antioxidative components (total phenolic and flavonoid contents) and their antioxidant activities (DPPH and ABTS radical scavenging activities). The quality characteristics of carrots were estimated in terms of hardness, length, weight, moisture contents, and soluble solid content (SSC). Conventionally grown carrots showed higher values than organic carrot in terms of hardness (p<0.05), but there was no significant difference in moisture contents or SSC. In the case of antioxidant activity, organic carrots showed a higher value for DPPH radical scavenging activity (p<0.05). However, there was no significant difference in other antioxidants. Consequently, quality characteristics and antioxidant activities were different between organically and conventionally grown carrots.

Increasing use of organically grown foods has renewed interest in the relationship between agricultural methods and food quality. The objective of this study was to evaluate the physicochemical characteristics and antioxidant activities of organic strawberries. For this study, strawberries were measured in terms of quality characteristics, including weight, length, diameter, hunter color, soluble solid contents (SSC), moisture contents, and pH, as well as antioxidant activities, including DPPH and ABTS radical scavenging activities and total phenol and flavonoid contents. Consequently, conventional strawberries showed higher weight, diameter, and L (lightness) and b (yellowness) values than organic strawberries (p<0.001). Length, moisture contents, pH, a (redness) value, and DPPH and ABTS radical scavenging activities were similar (p<0.05). However, organic strawberries showed higher SSC and total flavonoid and phenol contents than conventional strawberries (p<0.001). These results indicate that there were significant differences between organic and conventional agriculture techniques.

This research was conducted to investigate the effect of essential oil (EO) from Artemisia Princeps Pampanini on quality of tomato during storage. EO was extracted by steam distillation and diluted by 1 and 2%. Total phenolic contents and antioxidative activities of EO were analyzed. Tomato was packaged corrugated box covered with polypropylene (PP) film containing EO (1 and 2%) and then stored at room temperature for 10 days. During storage, appearance, weight loss rate, soluble solid contents, pH and a (redness) value were measured for tomato. Total phenolic contents of EO increased in a dose-dependence. The DPPH and ABTS radical scavenging activities also showed a concentration-dependent increase. The weight loss rate was lowest using the film packaged in 1% EO. During the storage period, soluble solid contents and pH increased in all treatments. The a value increased regardless of EO concentration in films. Especially, tomato packaged with EO film showed a lower a value than non EO-packaged ones. This result suggests that application of EO to film is effective for tomato quality preservation.