• Title/Summary/Keyword: stress concentration factors

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Physiological Changes of Saccharomyces cerevisiae KNU5377 Occurred in the Process of the 48-hour Ethanol Fermentation at 40℃ (40℃ 48시간 에탄올발효 과정 중 일어나는 Saccharomyces cerevisiae KNU5377의 생리 변화)

  • Kwak, Sun-Hye;Kim, Il-Sup;Kang, Kyung-Hee;Lee, Jung-Sook;Jin, Ingn-Yol
    • Journal of Life Science
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    • v.21 no.1
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    • pp.146-154
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    • 2011
  • In this study, physiological changes in a thermotolerant yeast Saccharomyces cerevisiae KNU5377 cell exposed to 48-hour alcohol fermentation at $40^{\circ}C$ were investigated. After 12 hours of alcohol fermentation at $40^{\circ}C$, the $C_{16:1}$ unsaturated acid of plasma membrane increased to 1.5 times more than the $C_{16:0}$ saturated fatty acid, and to about 2 times more for the $C_{18:1}$ unsaturated fatty acid. Fermentation at both $30^{\circ}C$ and $37^{\circ}C$ fermentation showed the same pattern as that done at $40^{\circ}C$. The pH of the alcohol-fermentation medium was reduced to pH 4.1 from a starting pH of 6.0 through the 12-hr fermentation and then maintained this level during the continuing fermentation. With the process of fermentation, the remaining glucose was reduced, but its amount remaining during the $40^{\circ}C$-fermentation was less reduced than those fermented at $30^{\circ}C$ and $37^{\circ}C$. In the study investigating the changing pattern of cellular proteins in the alcohol-fermenting cells, the SDS-PAGE and 2-D data indicated the most expressed dot was phosphoglycerate kinase, which is one enzyme involved in glycolysis. Why this enzyme was most expressed in the cells exposed to unfavorable conditions such as high temperature, increasing concentration of produced alcohol and long time exposure to other stress factors remains unsolved.

The Relationship between the Urinary Arsenic and 8-Hydroxydeoxyguanosine Levels in Women of Abandoned Mine Area (일부 폐금속광산 지역 거주 여성의 요중 비소와 8-hydroxydeoxyguanosine 농도 사이의 관련성)

  • Choi, Young-Sook;Eom, Sang-Yong;Choi, Byoung-Sun;Park, Jung-Duk;Kim, Yong-Dae;Kim, Heon
    • Journal of Life Science
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    • v.20 no.4
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    • pp.618-622
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    • 2010
  • This study examines the relationship between urinary arsenic concentration and urinary 8-hydroxydeoxyguanosine (8-OHdG) concentrations, an index of oxidative DNA damage, among women who live near abandoned metal mines. The sample consisted of 165 residents living near two abandoned metal mines located in Chungbuk Province. Demographic characteristics as well as environmental factors relevant to arsenic exposure were collected through interviews, and urinary arsenic concentrations and urinary 8-OHdG concentrations of the research subjects were measured. The collected data were subsequently analyzed using the statistics program SPSS 12.0. The geometric average of urinary arsenic concentrations among the research subjects was $5.65\;{\mu}g/g$ creatinine. In a correlation analysis between urinary arsenic and 8-OHdG concentrations, the correlation coefficient was significant (p<0.001) at 0.399. This study suggests that urinary 8-OHdG concentrations may be a DNA damage marker for chronic arsenic exposure in women.

Changes of Phytohormones in Rice and Tobacco Protoplasts under Different Cultural Conditions (벼와 담배의 원형질체 배양조건에 따른 식물호르몬의 변화)

  • 황태익;민경수;임현옥;안장순
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.1
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    • pp.33-41
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    • 1997
  • This study was carried out to establish simple and easy methods to judge the survival, senescence and death of the protoplasts in culture system by identifying the marker substance related to metabolic status of the cells. When rice and tobacco protoplasts were cultured in MS and KM-8P media containing 2,4-D or coconut milk ABA decreased especially in the media containing coconut milk, but GA$_3$, IAA and zeatin increased as the cultures progressed. The decrease of ABA and increase of zeatin was especially remarkable. When the supraoptimal amount of osmoticum (mannitol) was added to the culture media ABA decreased after a momentary increase, but other growth hormones slowly increased as the concentration of the osmoticum increased. Contents of individual hormones were contrasted when protoplasts rice and tobacco were cultured on the same medium containing 10mM super mine or NaCl. Tobacco protoplasts were more sensitive to NaCl stress and stopped protoplast division at the late stage of culture. Protoplast viability decreased greatly in 48 hours when the protoplast were at 32$^{\circ}C$ on a medium lacking several components. ABA content increased up to 10 days from incubation in negative proportion to the protoplast viability. On the other hand contents of other growth hormones, especially zeatin, decreased. The present results clearly showed that the contents of individual growth hormones in the plant protoplasts in culture varied sensitively in response to environmental factors that they are faced with. This indicates that the physiological states of the protoplast, such as survival, senescence or death can be simply judged based on the quantitative analysis of those hormones by ELISA.

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Isolation of $NH_4^+$-Tolerant Mutants of Actinobacillus succinogenes for Succinic Acid Production by Continuous Selection

  • Ye, Gui-Zi;Jiang, Min;Li, Jian;Chen, Ke-Quan;Xi, Yong-Lan;Liu, Shu-Wen;Wei, Ping;Ouyang, Ping-Kai
    • Journal of Microbiology and Biotechnology
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    • v.20 no.8
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    • pp.1219-1225
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    • 2010
  • Actinobacillus succinogenes, a representative succinicacid-producing microorganism, is seriously inhibited by ammonium ions, thereby hampering the industrial use of A. succinogenes with ammonium-ion-based materials as the pH controller. Therefore, this study isolated an ammonium-ion-tolerant mutant of A. succinogenes using a continuous-culture technique in which all the environmental factors, besides the stress (ammonium ions), were kept constant. Instead of operating the mutant-generating system as a nutrient-limited chemostat, it was used as a nutrient-unlimited system, allowing the cells to be continuously cultured at the maximum specific growth rate. The mutants were isolated on agar plates containing the acid-base indicator bromothymol blue and a high level of ammonium ions that would normally kill the parent strain by 100%. When cultured in anaerobic bottles with an ammonium ion concentration of 354 mmol/l, the mutant YZ0819 produced 40.21 g/l of succinic acid with a yield of 80.4%, whereas the parent strain NJ113 was unable to grow. When using $NH_4OH$ to buffer the culture pH in a 3.0 l stirredbioreactor, YZ0819 produced 35.15 g/l of succinic acid with a yield of 70.3%, which was 155% higher than that produced by NJ113. In addition, the morphology of YZ0819 changed in the fermentation broth, as the cells were aggregated from the beginning to the end of the fermentation. Therefore, these results indicate that YZ0819 can efficiently produce succinic acid when using $NH_4OH$ as the pH controller, and the formation of aggregates can be useful for transferring the cells from a cultivation medium for various industrial applications.

Association of the Nutritional Status and Essential Amino Acids Intake in Hemodialysis Patients (혈액투석환자에서 영양상태와 필수아미노산 섭취의 관련성 연구)

  • Kim, Hye-Jin;Kim, Su-An;Sohn, Cheong-Min
    • Journal of Nutrition and Health
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    • v.39 no.7
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    • pp.617-623
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    • 2006
  • The mortality and morbidity rate of hemodialysis patients (HD) remain high. Among many factors, protein and calorie malnutrition has been shown to be a major risk factor for increased mortality in the HD patients population. Malnutrition can be caused by insufficient amino acid intake, nutrient losses in dialysate, oxidant stress and muscle catabolism. In this study, we evaluated the association of markers of nutritional status and essential amino acids intake in HD patients. We investigated nutritional status of 41 HD patients (mean age: $64.2\;{\pm}\;11.5\;y$, men: 24, women: 27) by measuring anthropometric, biochemical parameters and food intakes by using 24 hr recall methods. Subject's total energy intake and total protein intake were $1,648.0\;{\pm}\;397.31\;kcal/day,\;79.2\;{\pm}\;27.2\;g/day$:, respectively. The animal protein intake was $42.7\;{\pm}\;22.1\;g/day$, essential amino acids intake was $23.4\;{\pm}\;9.92\;g/day$, and the ratio of essential amino acids to total protein intake was $29.6\;{\pm}\;5.42%$. There were significantly positive correlation between muscle mass and lean body mass with serum creatinine level (r=0.435, p<0.01; r=0.435, p<0,01). There were also significant positive correlation in muscle mass and lean body mass with pre hemodialysis blood urea nitrogen (preHD BUN) (r=0.329, p<0.05; r=0.329, p<0.05). There were no significant correlation in total energy intake and total protein intake per kg ideal body weight (IBW) to muscle mass and lean body mass. However, there were significantly positive correlation between the ratio of essential amino acids and muscle mass and lean body mass (r=0.368, p<0.05; r=0.405, p<0.01). And serum hematocrit concentration was positively correlated with the ratio of essential amino acids (r=0.032, p<0.05). The results of this study indicate that strong associations exist in essential amino acid intakes with malnutrition than total protein intakes in HD patient. In conclusion, specialized nutrition education should be necessary to efficiently improve the quality of protein intakes.

Antioxidant Activity and Physiological Function of the Anomala albopilosa Extracts (청동풍탱이(Anomala albopilosa)추출물의 항산화성 및 생리기능)

  • Yoon, Weon-Jong;Lee, Jung-A;Kim, Ji-Young;Kim, Sang-Bum;Park, Soo-Yeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.670-677
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    • 2007
  • We analyzed antioxidant and physiological activities to investigate the functional effects of ethanol extracts of Anomala albopilosa imago and A. albopilosa larva. In order to effectively screen for anti-inflammatory agents, we first investigated the antioxidant activities such as DPPH radical scavenging capacity, superoxide radical scavenging capacity, xanthine oxidase inhibitory activity, and nitric oxide scavenging capacity of the A. albopilosa extracts. By the screening system, we found that A. albopilosa extracts had antioxidant activity which increased with increments of the extract concentration. Moreover, we examined the inhibitory effect of the A. albopilosa extracts on the production of anti-inflammatory factors that the nitric oxide (NO), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and prostaglandin $E_2\;(PGE_2)$ production activated with LPS ($1{\mu}g/mL$) in murine macrophage cell line RAW 264.7. A. albopilosa extracts potentially inhibited the iNOS and COX-2 in a dose-dependent manner. The inhibition of iNOS activity was correlated with the decrease in nitrite levels. Additionally, the $PEG_2$ production is markedly inhibited after a treatment with the A. albopilosa extracts.

Effects of Rhizoma Coptidis Herbal Acupuncture applied to HapGok $(LI_4)$ on TNBS-induced Colitis in rats (흰쥐의 합곡부위(合谷部位)에 황련약침(黃連藥鍼)이 TNBS로 유발된 대장염(大腸炎)에 미치는 영향(影響))

  • Do, Jin-Woo;An, Sung-Hun;Koo, Sung-Tae;Baek, Tae-Bong;Kim, Kyung-Sik;Sohn, In-Chul
    • Korean Journal of Acupuncture
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    • v.21 no.2
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    • pp.95-110
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    • 2004
  • Objectives : Ulcerative colitis and Crohn's diseases are chronic inflammatory disease of the gastrointestinal tract identified mainly for diarrhea, stomachache, hemafecia. The source and pathologic mechanism about ulcerative colitis and Crohn's disease are still unknown but stress, infection, a genetic factor, environmental factors etc. may be the cause of chronic inflammatory disease of the gastrointestinal tract recently. Methods : Because ulcerative colitis and Crohn's disease is recognized as Ha-ri(下痢) or Jang-Byok(腸?) in Oriental Medicine, Rhizoma Coptidis Herbal acupunctures were injected in hapgok $(LI_4)$ which is used to treat intestinal disease in clinic. All animals were subjected to the injection of saline $(300\;{\mu}l,\;500\;{\mu}l)$ for a study control and TNBS $(300\;{\mu}l,\;500\;{\mu}l)$ into the lumen of the colon, 8cm proximal to the anus through the intestine. Rhizoma Coptidis Herbal (20 mg/ml, 0.4 ml) acupuncture solution was injected to the $LI_4$ (both hands) at the secondary injection time of TNBS in rats. And body weight, RBC count, WBC count, total protein, Paw edema rate, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels were observed to study the effects of Rhizoma Coptidis Herbal acupuncture in hapgok $(LI_4)$. Results : In results, Rhizoma Coptidis Herbal acupuncture in hapgok $(LI_4)$ on TNBS-induced colitis reduced the rate of weight loss but had no effect on RBC and WBC count. And it reduced total protein concentration, paw edema, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels. Conclusion : Data suggest that injection of Rhizoma Coptidis herbal acupuncture solution into hapgok has significant therapeutic effect on the colitis.

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Effect of Complex Extract Including Cornus officinalis on the Cimetidine/Ethanol-induced Erectile Dysfunction Model in Rats (산수유를 포함한 복합추출물이 cimetidine으로 발기부전을 유도한 동물모델에서 성기능 개선 효과)

  • Jang, Ji Hun;Kim, Tae Muk;Sim, Mi Ok;Nho, Jong Hyun;Jung, Ho Kyung;Lee, Mu Jin;Lee, Ki Ho;An, Byeong Kwan;Cho, Hyun Woo
    • Korean Journal of Plant Resources
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    • v.31 no.2
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    • pp.109-116
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    • 2018
  • Erectile dysfunction (ED), also known as impotence, is the inability to attain and sustain an erection firm enough to have sexual intercourse. Frequent ED may be a symptom of health problems including heart disease, obesity, alcoholism, stress, smoking, and depression, that need treatment. This study aimed to effect of complex extract (CPL) including Cornus officinalis on sexual function factor in the erectile dysfunction rat model. The erectile dysfuction rat model was induced by cimetidine (500 mg/kg in 5% ethanol, oral injection 2 weeks). Rats were oral administered with different concentration of CPL in rat erectile dysfunction model. As a results, sexual function factors (NO, cGMP) significantly improved in CPL treated groups (CPL-300, 600, 900 mg/kg) compared to CON group. Serum testosterone was increased in a dose-dependent manner after CPL treatment. Furthermore, administrations of CPL restored lumen areas of the prostate in the erectile dysfunction rat model. These results indicated that CPL alleviated erectile dysfunction by increasing sexual function factor and testosterone in rat model. CPL could be used to natural treatement for erectile dysfunction. However, further study is required to identify active ingredient and its mechanism of erectile dysfunction.

Artemisiae argyi herbal acupuncture of Hapgok (LI4) ameliorates TNBS-induced colitis in rats (합곡에 대한 애엽 약침이 흰쥐 대장염 완화에 미치는 효과)

  • Byun, Ki-Won;Lim, Yong-Soo;Koo, Sung-Tae;Kim, Jae-Hyo;Kim, Kyung-Sik;Sohn, In-Chul
    • Korean Journal of Acupuncture
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    • v.24 no.1
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    • pp.79-94
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    • 2007
  • Objectives : Ulcerative colitis and Crohn's disease are chronic inflammatory disease of the gastrointestinal tract was identified mainly for diarrhea, stomachache, hemafecia. The source and pathologic mechanism about ulcerative colitis and crohn's disease are still unknown but stress, infection, a genetic factor, environmental factors etc. may be the cause of chronic inflammatory disease of the gastrointestinal tract recently. The purpose of the present study is to evaluate the effects of herbal acupuncture with Artemisiae Argyi for the treatment to intestinal disease in the rat with 2, 4, 6 - trinitrobenzenesulfonic acid (TNBS) induced colitis. Methods : Artemisiae Argyi Herbal acupunctures were infected in HapGok (LI4) which is used to treat for intestinal disease in clinic. All animals were subjected to the injection of saline (300 ${\mu}l$, 500 ${\mu}l$) for a study control and TNBS (300 ${\mu}l$, 500 ${\mu}l$) into the lumen of the colon, 8cm proximal to the anus through the intestine. Artemisiae Agryi' Herbal (20 mg/ml, 0.4 ml) acupunctures were injected to the LI4 (both hands) at the secondary injection time of TNBS in rats. And body weight, RBC count, WBC count, total protein, Paw edema rate, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels were observed to study the effects of Artemisiae Argyi' Herbal acupuncture in HapGok (Ll4). Results : Artemisiae Argyi' Herbal acupuncture in HapGok (Ll4) on TNBS-induced colitis inhibit the body weight lose rate but not RBC and WBC count. Furthermore, it inhibited the reduction of total protein concentration, paw edema, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels. Conclusions : Herbal acupuncture with Artemisiae Argyi helps recover the TNBS-induced colonic damage and may be an important method for treatment of the colitis.

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Effect of the initial imperfection on the response of the stainless steel shell structures

  • Ali Ihsan Celik;Ozer Zeybek;Yasin Onuralp Ozkilic
    • Steel and Composite Structures
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    • v.50 no.6
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    • pp.705-720
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    • 2024
  • Analyzing the collapse behavior of thin-walled steel structures holds significant importance in ensuring their safety and longevity. Geometric imperfections present on the surface of metal materials can diminish both the durability and mechanical integrity of steel shells. These imperfections, encompassing local geometric irregularities and deformations such as holes, cavities, notches, and cracks localized in specific regions of the shell surface, play a pivotal role in the assessment. They can induce stress concentration within the structure, thereby influencing its susceptibility to buckling. The intricate relationship between the buckling behavior of these structures and such imperfections is multifaceted, contingent upon a variety of factors. The buckling analysis of thin-walled steel shell structures, similar to other steel structures, commonly involves the determination of crucial material properties, including elastic modulus, shear modulus, tensile strength, and fracture toughness. An established method involves the emulation of distributed geometric imperfections, utilizing real test specimen data as a basis. This approach allows for the accurate representation and assessment of the diversity and distribution of imperfections encountered in real-world scenarios. Utilizing defect data obtained from actual test samples enhances the model's realism and applicability. The sizes and configurations of these defects are employed as inputs in the modeling process, aiding in the prediction of structural behavior. It's worth noting that there is a dearth of experimental studies addressing the influence of geometric defects on the buckling behavior of cylindrical steel shells. In this particular study, samples featuring geometric imperfections were subjected to experimental buckling tests. These same samples were also modeled using Finite Element Analysis (FEM), with results corroborating the experimental findings. Furthermore, the initial geometrical imperfections were measured using digital image correlation (DIC) techniques. In this way, the response of the test specimens can be estimated accurately by applying the initial imperfections to FE models. After validation of the test results with FEA, a numerical parametric study was conducted to develop more generalized design recommendations for the stainless-steel shell structures with the initial geometric imperfection. While the load-carrying capacity of samples with perfect surfaces was up to 140 kN, the load-carrying capacity of samples with 4 mm defects was around 130 kN. Likewise, while the load carrying capacity of samples with 10 mm defects was around 125 kN, the load carrying capacity of samples with 14 mm defects was measured around 120 kN.