• 제목/요약/키워드: Heat Tolerance

검색결과 230건 처리시간 0.028초

남녀 고령자의 자각적 내한내열성과 겨울철 착의 행동 비교 (Comparison of Self-identified Thermal Tolerance and Wearing Habits in Winter between the Elderly Males and Females)

  • 박준희;백윤정;노상현;이주영
    • 한국의류학회지
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    • 제42권3호
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    • pp.530-543
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    • 2018
  • This study investigated elderly winter wearing habits and self-identified thermal tolerance in order to compare differences between older males and older females. We surveyed 269 participants: 119 males (age $76.9{\pm}5.9yr$) and 150 females (age $76.1{\pm}5.7yr$). Thirty one questionnaires were used: Self-identified cold and heat tolerance, clothing behavior, lifestyles related to the cold and health care, etc. High percentage of respondents (both males and females) felt vulnerable to the cold. The total number of outdoor clothes were $9.6{\pm}1.6$ and $10.6{\pm}1.6$ in males and females, respectively (p<.05). Wearing frequencies for thermal underwear were 84.0% and 82.4% in males and females, respectively. The using percentage of auxiliary heating devices was higher in females compared to males (p<.01). Males felt more cold in the head and face compared to females (p<.01). Self-identified cold tolerance had negative relationships with the total number of winter outdoor clothes for both males (r=-0.260) and females (r=-0.222) (p<.01). The perceived old age for both males and females was 72.4 yr. Sex differences should be considered when developing guidelines for winter clothing behavior for the elderly and educating them on how to improve health and cold tolerance.

Characterization of a Novel DWD Protein that Participates in Heat Stress Response in Arabidopsis

  • Kim, Soon-Hee;Lee, Joon-Hyun;Seo, Kyoung-In;Ryu, Boyeong;Sung, Yongju;Chung, Taijoon;Deng, Xing Wang;Lee, Jae-Hoon
    • Molecules and Cells
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    • 제37권11호
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    • pp.833-840
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    • 2014
  • Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.

불화계 양친매성 폴리아크릴아마이드의 합성과 용액거동 (Synthesis and Solution Properties of Fluorinated Amphiphilic Polyacrylamide)

  • Zhao, Fangyuan;Du, Kai;Yi, Zhuo;Du, Chao;Fang, Zhao;Mao, Bingquan
    • 폴리머
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    • 제39권3호
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    • pp.403-411
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    • 2015
  • A series of hydrophobically associating fluorinated amphiphilic polyacrylamide copolymers with remarkably high heat resistance and salt tolerance were synthesized by free radical micellar copolymerization, using acrylamide (AM) and sodium 2-acrylamido-tetradecane sulfonate ($AMC_{14}S$) as amphiphilic monomers, and 2-(perfluorooctyl) ethyl acrylate (PFHEA) as hydrophobic monomer. The structure of the terpolymer was characterized by FTIR, $^1H$ NMR and $^{19}F$ NMR. The solution properties of the terpolymers were investigated in details, and the results showed that the terpolymer solution had strong intermolecular hydrophobic association as the concentration exceeded the critical association concentration 1.5 g/L. The terpolymer solution possessed high surface activity, viscoelasticity, excellent heat resistance, salt tolerance and shearing resistance. The viscosity retention rate of copolymer solution was as high as 59.9% under the condition of fresh wastewater, $85^{\circ}C$ and a 60-days aging test.

하이드로포밍용 열연 강재의 레이저 용접성 및 성형 특성 (Laser Weldability and Formability of Hot Rolled Steels for Hydroforming Applications)

  • 이원범;이종봉
    • Journal of Welding and Joining
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    • 제22권6호
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    • pp.19-24
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    • 2004
  • The laser welding and its analysis of thin-sheet carbon steels were carried out with high power $CO_{2}$ laser. The main factor of weld quality of laser welding is gap and edge quality. This work was preformed to focus on the gap tolerance problem during laser welding. First, bead on plate welding of thin sheet was examined to investigate the effect of laser welding variables, and to obtain optimum welding condition. Butt welding was also carried out to show the effect of gap on the laser weldability of thin sheet. In order to investigate the effect of gap on formability of welded thin sheet, LDH test was caried out. At high welding speed, the partial penetration was obtained by low heat input. Otherwise, porosity was formed in the bead at low weld speed because of too much heat input. The optimum welding condition of welding was derived from bead width, penetration and hardness property. The maximum gap tolerance on laser welding was observed to be about 0.2mm. This gap size has good relationship with beam size of laser spot(about 0.3mm). The formability of welded sheet was about $80{\%}$ value of base metal and the gap size has not affected on the formability, although weld quality is dependent on the gap size.

Immobilized Saccharomyces cerevisia의 반응특성에 관한 연구 (Studies on the Reactive Characteristics of Immobilized Saccharomyces cerevisia in Ethanol Production)

  • 김성기
    • 한국환경보건학회지
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    • 제18권1호
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    • pp.84-94
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    • 1992
  • In an attempt to develop the immobilized biocatalysts based on immobilized Saccharomyces cerevisiae, immobilized yeast was investigated with respect to the conditions affected to ethanol productivities. Saccharomyces cerevisiae was immobilized in the form of the beads by magnetic-calcium alginate, non magnetic-calcium alginate and acrylamide polymerization. Magnetic immobilized yeast, nonmagnetic immobilized yeast and polyacrylamide immobilized yeast were compared in respect of their pH stability, thermostability, heat tolerance, the relation between the concetration of native yeast and retained activity of immobilized yeast, the activity depending on bead size of immobilized yeast, and the effects of magnesium and cobalt on the activities. The more small bead had retained the higher activity for the three kinds of immobilized yeast. In case of 1.0mm diameter of beads, the retained activity was 40~50% for the all groups. The pH stability profile for the immobilized yeast showed a broad range of optimun activity while the native yeast gave a sharp pick for its optimun pH value. The thermostability was at the range of 25~55$^{\circ}$C for the immobilized yeast groups. It was investigated that the influent magnesium and cobalt concentration, and the relative activity have an influent on heat tolerance at steady state. Both protein content released from immobilized yeast and activity of immobilized yeast were changed after activation of immobilized yeast cell.

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Saccharomyces cerevisiae KNU5377 with Multiple Stress Tolerance and its Potential as a Worldwide On-site Industrial Strain for Alcohol Fermentation

  • Paik, Sang-Kyoo;Ingnyol Jin;Yun, Hae-Sun;Park, Sae-Hun;Shin, Seong-Chul;Kim, Jae-Wan;Shin, Ki-Sun;Lee, Jung-Sook;Park, Yong-Ha
    • 한국미생물·생명공학회지
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    • 제30권4호
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    • pp.425-429
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    • 2002
  • Saccharomyces cerevisiae KNU5377 was examined to assay the recovering capacity against heat and other stressors. Along with a particular fermentation ability that is able to produce ethanol even at high temperature such as $40^{\circ}C$ with a comparable rate to the fermentation at $33^{\circ}C$, this strain also exhibited higher viability than a reference strain owing to its own thermotolerance that conferred the survival after the severe heat shock at $60^{\circ}C$ for 30 minutes. Furthermore, this strain showed outstanding tolerances against $H_2O_2$, ethanol and some chemical compounds. But, especially due to the thermotolerance, this strain has been suspected of other species of yeast. However, ITS (internally transcribed spacer) 1 and 2 sequencing data confirmed this strain was a typical strain of S. cerevisiae. The outstanding tolerances to various environmental stressors Indicate this S. cerevisiae KNU5377 is enough to use both as an on-site potential strain for world-wide alcohol fermentation industry and as a model strain for researches into the routes to acquire the tolerance to various stressors.

계절별 착의량이 안정시 에너지 대사량에 미치는 영향 (The Effect of Seasonal Clothing Weight on Resting Metabolic Rate)

  • 황수정;최정화;성화경
    • 한국의류학회지
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    • 제23권3호
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    • pp.483-494
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    • 1999
  • This study investigated the relation between seasonal variation of clothing weight and its resting metabolic rate to determine the relation between proper living temperature and cold/heat tolerance. Thirty six subjects(18 males and females twenties) were composed to obtain the clothing weight(Total clothing weight) and resting metabolic rate for a year and grouped four seasons : spring (Mar-May) Summer(Jun-Aug) Fall(Sep-Nov) and Winter(Dec-Feb). The data of males and females were respectively divided into three groups by cluster analysis with clothing weight. 1. The resting metabolic rate of male(41.1kcal/m2/hr) was higher than that of female(33.2kcal/m2/hr). It is suggested there is gender difference in the resting metabolic rate(p<.001) 2. The resting metabolic rate of male and female was the highest in Winter. It is suggested there is seasonal variation in the resting metabolic rate(p<.001) 3. It was found that there was relation between clothing weight and resting metabolic rate. The difference of resting metabolic rate between Summer and Winter which is profitable to adaptation to living temperature was significant in light clothing weight in male as well as in female. 4. In comfortable sensation most subjects responded that he/she felt 'comfortable' except Winter. However the heavy clothing weight group felt 'a little uncomfortable' throughout all seasons. l In thermal sensation most subjects responded that he/she felt 'neutral' And then the heavy clothing weight group responded warmer in summer and cooler in winter than light clothing weight group. From the results it was confirmed that male and female showed seasonal variations in clothing weight and resting metabolic rate. Also the resting metabolic rate of male and female was influenced by the clothing weight. In short seasonal variation of resting metabolic rate was larger in light clothing weight group than in heavy clothing weight group. Therefore light clothing weight group is advantgeous in living temperature to improve cold/heat tolerance and it also shows that living with the light clothing weight may enhance the degree of adaptation to change of living environment

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The immune enhancing effects and characteristics of Bifidobacterium longum and Bifidobacterium breve for the probiotic use in humans and animals

  • Park, Ho-Eun;Um, Hyun-Bum;Lee, Wan-Kyu
    • Journal of Biomedical and Translational Research
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    • 제19권4호
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    • pp.65-72
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    • 2018
  • The purpose of this study was to investigate probiotic characteristics and immune enhancing effects of Bifidobacterium (B.) longum KBB1-26 and BIF-4, B. breve KBB5-22 isolated from human intestine for probiotic use in humans and animals. We measured acid, bile and heat tolerance, antimicrobial activity against pathogenic bacteria, Escherichia (E.) coli, Salmonella (S.) Enteritidis, Staphylococcus (S.) aureus, and Listeria (L.) monocytogenes. Immune enhancing effects of B. longum and B. breve were investigated by measuring nitric oxide (NO), nuclear factor ($NF-{\kappa}b$), $interleukin-1{\beta}$ ($IL-1{\beta}$), interleukin-6 (IL-6), interleukin-12 (IL-12) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) in RAW 264.7 cells or RAW BLUE cells. B. longum KBB1-26 was survived at pH 2.0. B. longum KBB1-26 and BIF-4, B. breve KBB5-22 also showed tolerance to 0.3% of oxgall bile salt. B. longum KBB1-26 was able to survive at $70^{\circ}C$ and $80^{\circ}C$ for 20 min. KBB1-26 showed the antimicrobial inhibition zone to pathogenic bacteria such as E. coli (12 mm), S. Enteritidis (14 mm), S. aureus (14 mm) and L. monocytogenes (41 mm). The production of NO ($4.5{\pm}0.00{\mu}M/mL$) and $IL-1{\beta}$ ($39.7{\pm}0.55pg/mL$) of KBB1-26 significantly higher than BIF-4 and KBB5-22, respectively. In addition, KBB1-26 and KBB5-22 induce the production of high level of $TNF-{\alpha}$ and IL-6 in macrophages. Collectively, B. longum KBB1-26 have acid, bile, heat tolerance, antimicrobial activity and immune enhancing effects. These results suggest that KBB1-26 can be used as probiotics for humans and animals.