Improvement of heat and drought photosynthetic tolerance in wheat by overaccumulation of glycinebetaine

Wang, Gui-Ping,Hui, Zhen,Li, Feng,Zhao, Mei-Rong,Zhang, Jin,Wang, Wei The Korean Society of Plant Biotechnology 2010 Plant biotechnology reports Vol.4 No.3

Within their natural habitat, crops are often subjected to drought and heat stress, which suppress crop growth and decrease crop production. Causing overaccumulation of glycinebetaine (GB) has been used to enhance the crop yield under stress. Here, we investigated the response of wheat (Triticum aestivum L.) photosynthesis to drought, heat stress and their combination with a transgenic wheat line (T6) overaccumulating GB and its wild-type (WT) Shi4185. Drought stress (DS) was imposed by controlling irrigation until the relative water content (RWC) of the flag leaves decreased to between 78 and 82%. Heat stress (HS) was applied by exposing wheat plants to $40^{\circ}C$ for 4 h. A combination of drought and heat stress was applied by subjecting the drought-stressed plants to a heat stress as above. The results indicated that all stresses decreased photosynthesis, but the combination of drought and heat stress exacerbated the negative effects on photosynthesis more than exposure to drought or heat stress alone. Drought stress decreased the transpiration rate (Tr), stomatal conductance (Gs) and intercellular $CO_2$ concentration (Ci), while heat stress increased all of these; the deprivation of water was greater under drought stress than heat stress, but heat stress decreased the antioxidant enzyme activity to a greater extent. Overaccumulated GB could alleviate the decrease of photosynthesis caused by all stresses tested. These suggest that GB induces an increase of osmotic adjustments for drought tolerance, while its improvement of the antioxidative defense system including antioxidative enzymes and antioxidants may be more important for heat tolerance.

Effect of heat treatment residual stress on stress behavior of constant stress beam

Si Young Kwak,Ho Young Hwang 한국CDE학회 2018 Journal of computational design and engineering Vol.5 No.1

Although most casting and heat treatment processes generate significantly high residual stress in the products, this factor is generally not taken into account in the design stage of the product. In this study, experimental study and numerical analysis were conducted on a constant stress beam to examine effects of the residual stress generated during the heat treatment process on yielding behavior of the product in use. A constant stress beam of SUS 304 was designed in order to test the stress behavior related to resid-ual stress. The residual stresses generated during quenching heat treatment of the beam were measured in advance by ESPI (Electronic Speckle-Pattern Interferometry) equipment, and then the external stresses generated while applying a simple external load on the beam were measured. Also, the residual stress distribution generated during the heat treatment process was computed using a numerical analysis pro-gram designed for analyzing heat treatment processes. Then, the stress distribution by a simple external load to the beam was combined with the calculated residual stress results of the previous heat treatment step. Finally, the results were compared with experimental ones. Simulation results were in good agree-ment with the experimental results. Consistency between experimental results and computational results prove that residual stress has significant effects on the stress behavior of mechanical parts. Therefore, the residual stress generated in the previous heat treatment step of casting must be taken into account in the stage of mechanical product design.

Korean Red Ginseng and Korean black ginseng extracts, JP5 and BG1, prevent hepatic oxidative stress and inflammation induced by environmental heat stress

Song, Ji-Hyeon,Kim, Kui-Jin,Chei, Sungwoo,Seo, Young-Jin,Lee, Kippeum,Lee, Boo-Yong The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.2

Background: Continuous exposure to high temperatures can lead to heat stress. This stress response alters the expression of multiple genes and can contribute to the onset of various diseases. In particular, heat stress induces oxidative stress by increasing the production of reactive oxygen species. The liver is an essential organ that plays a variety of roles, such as detoxification and protein synthesis. Therefore, it is important to protect the liver from oxidative stress caused by heat stress. Korean ginseng has a variety of beneficial biological properties, and our previous studies showed that it provides an effective defense against heat stress. Methods: We investigated the ability of Korean Red Ginseng and Korean black ginseng extracts (JP5 and BG1) to protect against heat stress using a rat model. We then confirmed the active ingredients and mechanism of action using a cell-based model. Results: Heat stress significantly increased gene and protein expression of oxidative stress-related factors such as catalase and SOD2, but treatment with JP5 (Korean Red Ginseng extract) and BG1 (Korean black ginseng extract) abolished this response in both liver tissue and HepG2 cells. In addition, JP5 and BG1 inhibited the expression of inflammatory proteins such as p-NF-κB and tumor necrosis factor alpha-α. In particular, JP5 and BG1 decreased the expression of components of the NLRP3 inflammasome, a key inflammatory signaling factor. Thus, JP5 and BG1 inhibited both oxidative stress and inflammation. Conclusions: JP5 and BG1 protect against oxidative stress and inflammation induced by heat stress and help maintain liver function by preventing liver damage.

Korean Red Ginseng and Korean black ginseng extracts, JP5 and BG1, prevent hepatic oxidative stress and infl ammation induced by environmental heat stress

송지현,김귀진,Sungwoo Chei,Young-Jin Seo,Kippeum Lee,Boo Yong Lee 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.2

Background: Continuous exposure to high temperatures can lead to heat stress. This stress responsealters the expression of multiple genes and can contribute to the onset of various diseases. In particular,heat stress induces oxidative stress by increasing the production of reactive oxygen species. The liver isan essential organ that plays a variety of roles, such as detoxification and protein synthesis. Therefore, itis important to protect the liver from oxidative stress caused by heat stress. Korean ginseng has a varietyof beneficial biological properties, and our previous studies showed that it provides an effective defenseagainst heat stress. Methods: We investigated the ability of Korean Red Ginseng and Korean black ginseng extracts (JP5 andBG1) to protect against heat stress using a rat model. We then confirmed the active ingredients andmechanism of action using a cell-based model. Results: Heat stress significantly increased gene and protein expression of oxidative stresserelatedfactors such as catalase and SOD2, but treatment with JP5 (Korean Red Ginseng extract) and BG1(Korean black ginseng extract) abolished this response in both liver tissue and HepG2 cells. In addition,JP5 and BG1 inhibited the expression of inflammatory proteins such as p-NF-kB and tumor necrosisfactor alpha-a. In particular, JP5 and BG1 decreased the expression of components of the NLRP3inflammasome, a key inflammatory signaling factor. Thus, JP5 and BG1 inhibited both oxidative stressand inflammation. Conclusions: JP5 and BG1 protect against oxidative stress and inflammation induced by heat stress andhelp maintain liver function by preventing liver damage.

Korean ginseng extract ameliorates abnormal immune response through the regulation of inflammatory constituents in Sprague Dawley rat subjected to environmental heat stress

Song, Ji-Hyeon,Kim, Kui-Jin,Choi, Seo-Yun,Koh, Eun-Jeong,Park, JongDae,Lee, Boo-Yong The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.2

Background: Increases in the average global temperature cause heat stress-induced disorders by disrupting homeostasis. Excessive heat stress triggers an imbalance in the immune system; thus protection against heat stress is important to maintain immune homeostasis. Korean ginseng (Panax ginseng Meyer) has been used as a herbal medicine and displays beneficial biological properties. Methods: We investigated the protective effects of Korean ginseng extracts (KGEs) against heat stress in a rat model. Following acclimatization for 1 week, rats were housed at room temperature for 2 weeks and then exposed to heat stress ($40^{\circ}C$/2 h/day) for 4 weeks. Rats were treated with three KGEs from the beginning of the second week to the end of the experiment. Results: Heat stress dramatically increased secretion of inflammatory factors, and this was significantly reduced in the KGE-treated groups. Levels of inflammatory factors such as heat shock protein 70, interleukin 6, inducible nitric oxide synthase, and tumor necrosis factor-alpha were increased in the spleen and muscle upon heat stress. KGEs inhibited these increases by down-regulating heat shock protein 70 and the associated nuclear $factor-{\kappa}B$ and mitogen-activated protein kinase signaling pathways. Consequently, KGEs suppressed activation of T-cells and B-cells. Conclusion: KGEs suppress the immune response upon heat stress and decrease the production of inflammatory cytokines in muscle and spleen. We suggest that KGEs protect against heat stress by inhibiting inflammation and maintaining immune homeostasis.

Expression of Heat Shock Proteins by Heat Stress in Soybean

( Kitae Song ),( Won Cheol Yim ),( Byung-moo Lee ) 한국육종학회 2017 Plant Breeding and Biotechnology Vol.5 No.4

Heat stress is one of the factors disturb productivity and growth of plants. Many genes including heat shock protein (HSP), heat shock transcription factors (HSF) and chaperones, were identified and characterized in many plants to play role in increased tolerance to abiotic stress. To reveal responsive gene to heat stress, we performed RNA-seq using two Korean soybean varieties under heat stress and normal conditions. The transcripts were analyzed, and we obtained 2,458 genes including 46 co-up regulation and 55 co-down regulated genes in both soybean varieties. We also revealed HSPs, HSFs and chaperones in the differentially expressed genes using BLAST and Pfam analyzation and verified expression changes under heat stress. Finally, we find 68 genes involved in HSP, HSF, chaperones in heat responsive genes associated increasing heat tolerance. As a result, relatively small HSP families were up regulated and continuously expressed in long period heat stress. On the other hand, large molecule HSPs, HSFs and chaperonin did not response to long heat stress. The expression profiling and characterization provide invaluable information to understand heat tolerance of soybean.

황련해독탕(黃連解毒湯)이 외열 스트레스(火邪)에 의한동물모델에서 c-fos 발현에 미치는 영향 연구

황덕상 ( Deok Sang Hwang ),김효근 ( Hyo Geun Kim ),김태미 ( Tae Mi Kim ),이태희 ( Tae Hee Lee ),오명숙 ( Myung Sook Oh ) 대한한방부인과학회 2014 大韓韓方婦人科學會誌 Vol.27 No.3

Objectives: Hwangryunhaedok-tang (HH) is a representative heat clearing multiherb prescription. We evaluated the protective effect of HH against heat stress exposure in mice. Methods: Six weeks old ICR mice were used for this study. After 43℃ heat stressfor 15 minutes, we evaluated the changes of motor activity and c-fos expression level to determine the proper heat stress and evaluation time. The subjects were divided into 4 groups (1. control group, 2. heat stress group with normal saline, 3. heat stress group with administration of 100 mg/kg, and 4. heat stress group with administration of 1000 mg/kg). After oral administration of HH once a day for 3 days,2, 3, 4 groups were exposed to 43℃ heat stress for 15 minutes. Then, we evaluated the motor activity for 120 minutes and analyzed the c-fos expression using western blot. We investigated the effect of HH and its ingredients on c-fos expressions afterheat stress. The mice were administrated HH, Scutellariae Radix, Coptidis Rhizoma, Phellodendri Cortex, and Gardeniae Fructus for 3 days. After one hour of last treatment, the mice were exposed to heat stress at 43℃ for 15 min. After two hours, the hypothalamus was dissociated and lysed to measure c-fos expression. Results: After oral administration of HH for 3 days, motor activity was recovered insignificantly. 100 mg/kg HH treatment reduced the c-fos expression after heat stress but insignificantly. Among the ingredients of HH, Coptidis Rhizoma and Scutellariae Radix treatment groups significantly reduced the c-fos after stress. Conclusions: These results show that Hwangryunhaedok-tang may be effective to reduce the heat stress response.

Using heat sink technology to decrease residual stress in 316L stainless steel welding joint: Finite element simulation

Jiang, Wenchun,Zhang, Yucai,Woo, Wanchuck Elsevier 2012 The International journal of pressure vessels and Vol.92 No.-

<P><B>Abstract</B></P><P>316L type stainless steel is widely used in chemical industries due to its excellent resistance to corrosion. But the welding residual stresses have a great effect on stress corrosion cracking. This paper used finite element method to study the effect of heat sink on residual stress. The effects of contact length and the average heat transfer coefficient on residual stress have been investigated. It is found that the heat sink technology can decrease the residual stress greatly. Compared to the model without heat sink, 20% of the peak longitudinal stress has been reduced. The heat sink decreases the dwell time during cooling from 850 °C to 400 °C, which is helpful to decrease the risk of sensitization of 316L stainless steel. With the contact length increase, the transverse stress is decreased. Further increase of the contact length has no positive effect on reducing the longitudinal stress. With the average heat transfer coefficient increase, the transverse stress is decreased greatly while the longitudinal stress decreases slightly, and some tensile residual stresses have been changed to compressive in some zone.</P> <P><B>Highlights</B></P><P>► Heat sink decreases the residual stress and increases the cooling rate. ► The heat sink decreases the dwell time during the cooling from 850 to 400 °C. ► With the contact length increases, residual stresses are decreased. ► With the heat transfer coefficient increases, residual stresses are decreased.</P>

Effect of heat treatment residual stress on stress behavior of constant stress beam

Kwak, Si Young,Hwang, Ho Young Society for Computational Design and Engineering 2018 Journal of computational design and engineering Vol.5 No.1

Although most casting and heat treatment processes generate significantly high residual stress in the products, this factor is generally not taken into account in the design stage of the product. In this study, experimental study and numerical analysis were conducted on a constant stress beam to examine effects of the residual stress generated during the heat treatment process on yielding behavior of the product in use. A constant stress beam of SUS 304 was designed in order to test the stress behavior related to residual stress. The residual stresses generated during quenching heat treatment of the beam were measured in advance by ESPI (Electronic Speckle-Pattern Interferometry) equipment, and then the external stresses generated while applying a simple external load on the beam were measured. Also, the residual stress distribution generated during the heat treatment process was computed using a numerical analysis program designed for analyzing heat treatment processes. Then, the stress distribution by a simple external load to the beam was combined with the calculated residual stress results of the previous heat treatment step. Finally, the results were compared with experimental ones. Simulation results were in good agreement with the experimental results. Consistency between experimental results and computational results prove that residual stress has significant effects on the stress behavior of mechanical parts. Therefore, the residual stress generated in the previous heat treatment step of casting must be taken into account in the stage of mechanical product design.

소방관의 열 압박에 대한 수분의 영향

윤기종 한국섬유공학회 2019 한국섬유공학회지 Vol.56 No.1

The greatest cause of fatality of fire fighters is heat stress rather than suffocation or burns. Heat stress increases the probability of heart attacks to a great extent and this was found to be the major cause of fatality of fire fighters. The effect of humidity on heat stress has been studied and is widely documented, however it appears that not enough attention is practiced in fire fighting. As fire fighter turnout gear often get wet when they are fighting fire, this paper attempts emphasize the importance of trying to keep the turnout gear as dry as possible to reduce the damaging effect of moisture on the heat stress that fire fighters experience. When fire fighters enter burning buildings other fire fighters spray water from a distance at the point of entry to reduce the intensity of fire there. The effect of added moisture on the temperature and relative humidity between the internal layers of the turnout gear is studied to infer the effect on heat stress. Preliminary experiments exposing a multilayer assembly whose outer layer is either conditioned or wetted on a radiant heat transfer equipment and measuring the change in temperature and humidity at two locations between the layers suggest that the transport of moisture carrying the external heat inward has a significant effect on the heat stress a fire fighter might experience. The data is analyzed with a typical heat stress index table as a first approximation of the heat stress the fire fighter might experience. The results suggests that the presence of moisture has extensive effect on the heat stress and that they should try to keep their turnout gear as dry as possible.