• Title/Summary/Keyword: Life-stress

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A Study on Durability Improvement of Breech Block for 30mm Automatic Gun (30mm 자동포용 폐쇄기의 내구성 향상에 관한 연구)

  • Park, Young Min;Kim, Sung Hoon;Noh, Sang Wan;Kim, Sung Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.5
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    • pp.47-53
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    • 2020
  • The purpose of this study was to increase product reliability by improving the durability of the breech block for a 30mm Automatic Gun. The breech block is a key component of a gun that functions as chambering, closing, and extracting. The breech block requires high reliability, which needs to be improved because cracks of a breech block can occur early in operation. Cause analysis confirmed that the crack is caused by repeated impacts. Therefore, the following improvement measures were studied, and the effects were demonstrated using a firing test. The energy of impact absorption was increased by changing the material, and the stress concentration was mitigated by increasing the value of R. In addition, the fatigue life was increased by adding Shot-peening, deleting chromium plating, and changing the forging method. The firing test did not show firing trouble for up to 5,000 rounds. The start timing of the crack was delayed, and the depth was small. Therefore, the improved product was more durable than the existing product. This study can be used as a useful reference when assessing the improvement of the durability of similar products, life study, and criteria for crack acceptance.

The Effect of Carrot Juice, ${\beta}$-carotene Supplementation on Plasma Antioxidant Status of Korean Smokers (당근즙 및 ${\beta}$-Carotene의 섭취가 흡연자의 혈장 항산화 영양 상태에 미치는 영향)

  • Lee, Hye-Jin;Park, Yoo-Kyoung;Kang, Myung-Hee
    • Journal of Nutrition and Health
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    • v.42 no.8
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    • pp.750-758
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    • 2009
  • Smoking is associated with an increased incidence of numerous cancers and other degenerative diseases. It has been suggested that high consumption of fruits and vegetables may give some protection. Especially carrot is the most important source of dietary ${\beta}$-carotene. Therefore, the objective of this study is to investigate whether carrot juice supplementation to smokers have different or superior effect of compared to the effect supplementing purified ${\beta}$-carotene. The study was conducted in a randomized and placebo-controlled design, after a depletion period of 14 days, 48 smokers were supplemented either carrot juice (n = 18), purified ${\beta}$-carotene (n = 16) or placebo (n = 14). Each group was supplemented for 8 weeks with approximately 20.49 mg of ${\beta}$-carotene/day and 1.2 mg of vitamin C/day, as carrot juice (300 mL/day) or purified ${\beta}$-carotene (1 capsule/day). Plasma vitamin C, vitamin E and ${\beta}$-carotene level were significantly increased after carrot juice and ${\beta}$-carotene supplementation. These results suggest that carrot juice containing ${\beta}$-carotene or ${\beta}$-carotene itself have similar antioxidative potentials by increasing the antioxidant potential in smokers. Therefore, we suggest moderate dose of vitamin supplementation (amount of two servings of vegetable intake) may help to replenish the decreased oxidative stress levels in smokers.

Effect of Korean Soup(Tang) upon Customers Royalty in the Food Service Industry in Korea (외식급식산업에 있어서 국(탕)이 고객 충성도에 미치는 영향)

  • 이영남;노성윤
    • Journal of the East Asian Society of Dietary Life
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    • v.13 no.5
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    • pp.482-493
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    • 2003
  • This study has been designed to stress the thoughts that soups should be offered taking into account customer's preference aimed at leading to eventual customer's satisfaction and the importance that Korean traditional food should take the lead in shifting dining-out industry's paradigm to customer-orientation instead of product-orientation. From August 15 through August 30, 2003, the drawn-up questionnaires were handed out to 500 numbers of adults aged over 20 living in Seoul, metropolitan city of Korea and the finally collected 361 questionnaires from them have been analysed as a subject for this study. It showed that the male respondents(44%) dined out much more frequently than the female respondents(35%) and their rate of 5,000-7,000 Won for a meal was most preferred as their average expenditure at one sitting in the restaurant. When eating Korean food at home or in a restaurant, the majority(5l,3%) of them think the soups(Tang) should be served coupled with their ordered meals. Among soups using flesh and meat as a staple material, they most preferred beef & bone soup(33.2%), followed by beep rib soup(30.4%) and beef soup with seasoned red pepper(l0.8%), and among soups using fish & shell and crustacean as a staple material, most preferred were hot fish soup(20.6%), loach soup(l5.2%) and hot crab soup(11.4%). Among soups using beans as a staple material, they most preferred soybean paste stew(33.2%), uncurdled soybean curd stew(29.4%) and Dambuk stew(l5.8%). Among soups using fowls and birds as a staple material, chicken soup with ginseng(51.9%), plain chicken soup(l8.4%) and chicken soup with red pepper sauce(l2.3%) falls on the most preferred. Among soups using vegetables and seaweeds as a staple material, most preferred are sea mustard soup(25.3%), Kimchi soup(16.8%), soybean paste soup with Chinese cabbage(13.0%) and bean sprout soup(10.1%). The soups(Tang) most preferred in the morning time are those soups whose staple materials are vegetables and seaweeds, such as sea mustard soup, bean sprout soup, Kimchi soup and soybean paste soup with Chinese cabbage while the soups most preferred for the lunch time are beef & bone soup, beep rib soup, chicken soup with ginseng and beef soup with seasoned red pepper while beef soup with seasoned red pepper, beef & bone soup, soybean curd stew and Kimchi soup are most preferred soups for the dinner time. The survey showed that 41 % of the subject preferred chicken soup with ginseng for a food considered good by themselves for their health. The male respondents preferred Bosin-tang(soup of edible-dog meat) than the female counterparts did, while the female respondents preferred chicken soup with ginseng than the male counterparts did. The survey showed that when eating korean traditional food, 70% of the subject are visiting a restaurant where soups are cooked delicious while 61% of the subject think that price does not matter if only food tastes good, which is reflecting that taste of food is a decisive factor in selecting menu rather than its price is. In conclusion, you can say that taste of soup is the most important factor creating steady customer in the restaurant, taking it into account Korean people most prefer their traditional food when dining out.

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Resveratrol Upregulates p21, Cell Cycle Regulator, in Gaucher Disease Cells (Gaucher병에서 resveratrol의 세포주기 조절자 p21을 통한 세포보호 효과 연구)

  • Kim, Dong-Hyun;Heo, Tae-Hwe;Kim, June-Bum;Kim, Sung-Jo
    • Journal of Life Science
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    • v.20 no.8
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    • pp.1281-1286
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    • 2010
  • Gaucher disease (GD) is caused by glucocerebrosidase functional deficiency and the most prevalent lysosomal storage disorder (LSD), with an incidence of about 1 in 20,000 new births. Resveratrol, one kind of phytoalexin, is a produced naturally by several plants and has anti-tumor, anti-aging, anti-inflammatory and neuro-protective effects. In this paper we provide the cellular protective effect of resveratrol in both type I and type II Gaucher disease cells. Resveratrol treatment did not show any significant change in the p21 and p53 mRNA expression level, however expression level of the p21 protein, a cell cycle arrest factor, shows significant increment in both types of Gaucher disease cells. These cell cycle arrest patterns were confirmed by both MTT assay measurement and microscopy detection. In comparison, expression level of poly ADP ribose polymerase (PARP), an apoptosis indicator protein, was significantly decreased in both type I and II Gaucher disease cells after treatment with resveratrol. This result indicates that resveratrol relievescellular apoptotic stress fromtype I and II Gaucher disease cells. Therefore, we demonstrate that resveratrol inhibits cell proliferation via p21 activity and activates cellular repair systems for Gaucher disease cells. Our results provide at least one of the molecular mechanisms of Gaucher disease and may allow the verification of potential drug targets for therapeutic trials.

The Effect of Aerobic Exercise and Allium Tuberosum Intake on Blood Lipids, MDA and Antioxidant Enzyme in Rats (유산소 운동과 부추섭취가 혈중지질, 지질과산화 및 항산화효소에 미치는 영향)

  • Baek, Yeong-Ho;Lee, Sang-Ho
    • Journal of Life Science
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    • v.20 no.2
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    • pp.245-252
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    • 2010
  • The purpose of this study was to investigate the effects of aerobic exercise and Allium tuberosum intake on blood lipids, MDA and antioxidant enzyme in rats. Twenty four male Sprague-Dawley rats, 4 weeks old, were used. Experimental groups were aerobic exercise with Allium tuberosum intake group (A, n=6), aerobic exercise group (B, n=6), Allium tuberosum intake group (C, n=6), and the control group (D, n=6). Aerobic exercise was administered through a treadmill running program (14~15 m/min, $0^{\circ}$ grade, 25~30 min/day, 5 day/wk) and these rats were given 5% Allium tuberosum for 2 wk. The results of this study are as follows: TC and TG didn't show change; groups A, B, C showed a significant increase in HDL-C compared to the D group; groups A, B, and C showed a significant decrease in LDL-C compared to the D group; groups B and C showed a significant decrease in MDA level compared to the D group; groups B and C showed a significant increase in SOD activity compared to the D group; and the A group showed a significant increase in CAT activity compared to the D group. In conclusion, low intensity aerobic exercise and intake of the natural antioxidant Allium tuberosum seem to have the health promoting effect of retarding oxidative stress by decreasing lipid peroxidation.

Observed through the stories of herbal remedies Jeom-hyeol-gigong, philological research of Su-gi therapy (점혈기공요법(點穴氣功療法)을 통해 본 수기요법(手氣療法)의 문헌적(文獻的) 연구(硏究))

  • Kim, In-Chang;Seo, Yun-Huie
    • Journal of Korean Medical Ki-Gong Academy
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    • v.11 no.1
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    • pp.236-261
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    • 2009
  • 'Jeom-hyeol-gigong(點穴氣功)' gives a drill, Gi(氣) as a place to jam. This pathogen(邪氣) is removed. Given the low places and supplement it energy to flow up the well is the cure. This is an internal organ and muscular Gi allows a natural flow. Blood, one that moves and guides Gi is Gi I still feel that it makes any blood, making you feel good in life is flowing with vitality. Gi driving our whole body, while supplying vital energy and blood circulation, helping to defend the body is functioning. 'Jeom-hyeol-gigong' principle of Gi where the blockages to flow naturally energy is to let the flow. Aura of the voluntary and proactive action will be to have healthy bodies. Gi as a whole-body blood circulation leading to the cells in each tissue to supply energy and nutrients to every cell as the original principles of free activities that will maximize your life. Gi to prevent the three causes Internal causes: 5 greed and 7 emotions External causes: climate, food, pathogens, stress, etc. The internal nor the external causes: internal and external factors that cause the complex elements, incorrect position of the bone caused by an imbalance Heart disease will be police officers and raise their resistance to disease than the body, what jung-gi(正氣) have to develop. Beneficial to human body's resistance to raise the jung-gi people young-gi(營氣) and wi-gi(衛氣) should be enhanced. If the form is perfectly possible, Gi cycle itself should not have to breathe. Abdominal diagnosis 'bok-su-ap-an-beop(伏手壓按法)', 'sam-ji-tam-an-beop(三指探按法)' hands are like this, which outlined five viscera in order to understand the problem, the lower side of the clavicle (lung), the pit of stomach (Heart), both the lower ribs (liver), navel below (kidney) can be diagnosed at such areas. In each area of the skin, abdominal muscle tension, aching, or pressing a fuss about, beating the ruling of the state and the problem is a clue. And mo-hyeol(募穴) and certain Acupressure group, the chest, back, belly, so that scattered around each' book 'of the problem can be found. This is also the target of such a diagnosis, such as shape, color of skin, muscle Mostly the scope of the pitch in the cervical spine is broad across the hips. sugi(手氣) method that 'an method(按法) and 'ma method(摩法), bak method(拍法) is.

Triathlon-Related Overuse Injury and Medical Issues (트라이애슬론의 과사용 부상과 의학적 위험요인에 대한 고찰)

  • Park, Chan-Ho;Kwak, Yi-Sub;Kim, Tae-Un
    • Journal of Life Science
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    • v.20 no.2
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    • pp.314-320
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    • 2010
  • As the nature of triathlons is competition in three successive sports, triathletes experience elevated levels of stress on the body that are absent in single-sport athletic events, and consequently there are more potential medical problems to prepare for. Triathletes can also experience problems such as hypothermia, heat illness, excessive exposure to ultraviolet radiation, musculoskeletal injuries and trauma, immunosuppression, and haemolysis. Depending on the potentiality of such above-listed problems occurring in any given race, race organizers will prepare preventative measures and treatments accordingly. Olympic distance is not the only triathlon racing distance. Sprints, which are normally around half the Olympic distance, are common distances, as well as Long (2 km swim, 80 km bike, 20 km run), Ironman (3.8 km swim, 180 km bike, 42 km run), and ultra-distance events varying in length. Races of longer duration normally result in a higher percentage of athletes experiencing the above-mentioned medical problems, as well as inducing additional health risks such as hyponatraemia. Minimizing the occurrences of serious health issues is possible through the following means: carefully preparing for the probable race-day weather conditions; proper management and organization of the race; preparing an extensive water-safety and ground-course safety plan; distributing necessary nutrition along the course; and stressing the importance for athletes to have proper knowledge concerning race nutrition, biomechanical technique, physical preparation, and utilization of safe equipment. While risks of competing in triathlon are many, the instances of such medical problems are not excessive, and the triathlon has a reputation of being a reasonably safe sport as long as athletes with high risk take added precautions.

Enhanced Production of Astaxanthin in Paracoccus haeundaensis Strain by Physical and Chemical Mutagenesis (물리·화학적 돌연변이 유도를 통한 Paracoccus haeundaensis의 astaxanthin 생산량 증대)

  • Seo, Yong Bae;Jeong, Tae Hyug;Choi, Seong Seok;Lim, Han Kyu;Kim, Gun-Do
    • Journal of Life Science
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    • v.27 no.3
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    • pp.339-345
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    • 2017
  • Carotenoids are natural lipid-soluble pigments, which are produced primarily by bacteria, algae, and plants. Many studies have focused on the identification, production, and utilization of natural sources of astaxanthin from algae, yeast, and crustacean byproducts as an alternative to the synthetic pigment, which is mostly used today. The aim of the present study was to identify a mutant of Paracoccus haeundaensis by exposure to UV and ethyl methanesulfonate (EMS). The mutant was then exposed to nutrient stress conditions to isolate an astaxanthin-hyperproducing strain, followed by characterization of the mutant. The survival rate decreased in accordance with an increase in the UV exposure time and an increase in the EMS concentration. A mutant of the original P. haeundaensis strain was identified that showed hyperproduction of astaxanthin following exposure to UV irradiation (20 min) and EMS treatment (0.4 M concentration). The optimal culture conditions for the PUE mutant were $25^{\circ}C$, pH 7-8, and 3% NaCl. The effects of various carbon and nitrogen sources on the growth and astaxanthin production of PUE were examined. The addition of 1% raffinose and 3% potassium nitrate influenced cell growth and astaxanthin production. The selected mutant exhibited an increase of 1.58 folds in astaxanthin content compared to initial wild type strain. A genetically stable mutant strain obtained using mutagen (UV irradiation and EMS treatment) may be a suitable candidate for further industrial scale production of astaxanthin.

Ethanol Extracts of Rheum undulatum and Inula japonica Protect Against Oxidative Damages on Human Keratinocyte HaCaT cells through the Induction of ARE/NRF2-dependent Phase II Cytoprotective Enzymes (종대황과 선복화 에탄올 추출물의 인간 피부 세포주인 HaCaT 세포에서 NRF2/ARE에 의존적인 유전자 발현의 유도를 통한 항산화 효과)

  • Yoo, Ok-Kyung;Lee, Yong-Geol;Do, Ki-Hoan;Keum, Young-Sam
    • Journal of Life Science
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    • v.27 no.3
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    • pp.310-317
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    • 2017
  • Mammalian cells control cellular homeostasis using a variety of defensive enzymes in order to combat against environmental oxidants and electrophiles. NF-E2-related factor-2 (NRF2) is a transcription factor that, in response to an exposure to oxidative stress, translocates into the nucleus and modulates the inducible expression of various phase II cytoprotective enzymes by binding to the antioxidant response element (ARE). In the present study, we have acquired 400 ethanol extracts of traditional medicinal plants and attempted to find out possible extract(s) that can increase the NRF2/ARE-dependent gene expression in human keratinocytes. As a result, we have identified that ethanol extracts of Rheum undulatum and Inula japonica strongly activated the ARE-dependent luciferase activity in HaCaT- ARE-luciferase cells. Exposure of ethanol extracts of Rheum undulatum and Inula japonica increased the viability and activated transcription and translation of NRF2-dependent phase II cytoprotective enzymes in HaCaT cells, such as heme oxygenase-1 (HO-1) and NAD[P]H:quinone oxidorecutase-1 (NQO1). In addition, ethanol extracts of Rheum undulatum and Inula japonica suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced generation of intracellular reactive oxygen species (ROS), thereby inhibiting the formation of 8-hydroxyguanosine (8-OHG) and 4-hydroxynonenal (4-HNE) in HaCaT cells. Together, our results demonstrate that ethanol extracts of Rheum undulatum and Inula japonica exert anti-oxidant effects via the induction of NRF2/ARE-dependent gene expression in human keratinocytes.

The Structural and Functional Role of p53 as a Cancer Therapeutic Target (암 치료 표적으로서 p53의 구조적 및 기능적 역할)

  • Han, Chang Woo;Park, So Young;Jeong, Mi Suk;Jang, Se Bok
    • Journal of Life Science
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    • v.28 no.4
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    • pp.488-495
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    • 2018
  • The p53 gene plays a critical role in the transcriptional regulation of cellular response to stress, DNA damage, hypoxia, and tumor development. Keeping in mind the recently discovered manifold physiological functions of p53, its involvement in the regulation of cancer is not surprising. In about 50% of all human cancers, inactivation of p53's protein function occurs either through mutations in the gene itself or defects in the mechanisms that activate it. This disorder plays a crucial role in tumor evolution by allowing the evasion of a p53-dependent response. Many recent studies have focused on directly targeting p53 mutants by identifying selective, small molecular compounds to deplete them or to restore their tumor-suppressive function. These small molecules should effectively regulate various interactions while maintaining good drug-like properties. Among them, the discovery of the key p53-negative regulator, MDM2, has led to the design of new small molecule inhibitors that block the interaction between p53 and MDM2. Some of these small molecule compounds have now moved from proof-of-concept studies into clinical trials, with prospects for further, more personalized anti-carcinogenic medicines. Here, we review the structural and functional consequences of wild type and mutant p53 as well as the development of therapeutic agents that directly target this gene, and compounds that inhibit the interaction between it and MDM2.