• Title/Summary/Keyword: Mg reduction

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Microstructure and High Temperature Deformation Behavior of Heat Resistant Stainless Steel for a Retort (열환원반응관용 내열강의 미세조직과 고온변형거동)

  • Choi, G.S.;Ha, T.K.
    • Transactions of Materials Processing
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    • v.22 no.3
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    • pp.165-170
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    • 2013
  • High temperature deformation behavior of a heat-resistant duplex stainless steel, used as a retort in the Pidgeon process for Mg production, was investigated in this study. 25Cr-8Ni based duplex stainless steels were cast into rectangular ingots, with dimensions of $350mm{\times}350mm{\times}100mm$. Nitrogen and yttrium were added at 0.3wt.% each to enhance the heat-resistance of the steel. Phase equilibrium was calculated using the thermodynamic software FactSage$^{(R)}$ and the database of FSStel. For comparison, cast 310S steel, a widely used heat-resistant austenitic stainless steel, was also examined in this study. Dilatometry was conducted on the as-cast ingots for the temperature range from RT to $1200^{\circ}C$ and the thermal expansion coefficients were evaluated. The nitrogen addition was found to have an effect on the thermal expansion behavior for temperatures between 800 and $1000^{\circ}C$. High temperature tensile and compression tests were conducted on the ingots for temperatures ranging from 900 to $1230^{\circ}C$, which is the operation temperature employed in Mg production by the Silico-thermic reduction process. The steel containing both N and Y showed much higher strength as compared to 310S.

Accumulation of Dietary Conjugated Linoleic Acid (CLA) in Silkworm, Bombyx mori

  • Park, Chung-Gyoo;Kim, Seck-Jong;Ha, Nam-Gue;Park, Bong-Il;Ha, Yeong-Lae
    • Preventive Nutrition and Food Science
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    • v.6 no.1
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    • pp.19-22
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    • 2001
  • Conjugated linoleic acid (CLA) exhibits potent anti-carcinogenic and other biological activities in several animal models. We report here that dietary CLA, chemically synthesized from corn oil, accumulates I silkworm, Bombyx mori, which is used as therapeutic agent for diabetes in Korea and Japan. Mulberry leaves treated with 0.1 or 10% CLA in ethanol were supplied to silkworms from the end of 3rd instar to the 3rd day of the 5th instar. Fresh mulberry leaves or leaves treated with 10% corn oil in ethanol were fed as a check treatment. the amount of total lipids in the larval body ranged from 17.4 to 19.1mg/g of body tissue, which was not significantly affected by the source of the diets. No CLA was found in the control silkworms. But the level of CLA significantly increased to 83.5 mg/g of fat, when fed with mulberry leaves treated with 10% CLA. Only trace amounts of CLA were detected in the larvae reared with check leaves and 0.1% CLA-treated leaves. Mulberry leaves treatd with corn oil or CLA were not palatable to the larvae, resulting in a reduction of larval weight. These results suggest that silkworms containing CLA in body lipids could be producted by dietary CLA.

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Toxic Effects of Serpentine Soils on Plant Growth

  • Kim, Jeong-Myeong;Shim, Jae-Kuk
    • Journal of Ecology and Environment
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    • v.31 no.4
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    • pp.327-331
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    • 2008
  • Serpentine soils are distributed in a small area in Korea, and generally exhibit high contents of Ni, Cr, Fe, Mn, Co and Mg. We investigated the growth of woody plants and herbs in the Andong serpentine area, Korea. Pinus densiflora and P. rigida growing on serpentine soils have high contents of Fe, Mg, Ni and Co, with contents approximately twice as high as those of non-serpentine plants. Tree species on serpentine soil also had lower ratios of tree height/DBH than trees in a control area. In greenhouse culture experiments on two bodenvag herb species, Setaria viridis and Cymbopogon tortilis, the biomass of the plants was significantly affected by soil type but not by seed origins. After 66 days, the growth of S. viridis and C. tortilis seedlings was significantly inhibited in serpentine soil, and the dry weight of each species showed significant negative correlations with soil heavy metal contents (Ni, Co and Cr). These results suggest that the growth of plants was inhibited by properties of the serpentine soil, and in particular, their high heavy metal concentration, which induced dwarfing in woody plants and reduction of total plant biomass in herbs.

Inhibition of Matrix Metalloproteinases-12 (MMP-12) and Anti-oxidant Effect of Xanthohumol from Hop (Humulus lupulus L.)

  • Lee, Keyong Ho;Yoon, Won Ho
    • Natural Product Sciences
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    • v.18 no.4
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    • pp.261-265
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    • 2012
  • Xanthohumol was isolated from hops (Humulus lupulus L.), and then investigated anti-oxidant effect by AAPH-induced LLC-PK1 cell and oxygen radical absorbance capacity (ORCA) assays and MMP-12 inhibitory effect by direct MMP-12 inhibition assay. The treatment of xanthohumol protected LLC-PK1 cells from AAPH-induced cell damage such as cell viability, SOD and GSH-px reduction in a dose dependant manner (0.1, 1, and $5{\mu}M$), the SOD value was 2.98, 4.51, and 5.77 U/mg protein, and GSH-px value was 30.12, 49.32, and 60.11 U/mg protein. ORAC value of xanthohumol was showed as 4320, 12004, and $14209{\mu}M$ TE/g at the concentration 0.1, 1, and $5{\mu}M$, respectively. The change of SOD and GSH-px values was significantly correlated with the results of ORAC assay, that is, AAPH-induced cell and ORCA assays. In addition, inhibition of MMP-12 that is known to play an important role in skin aging was 14%, 37%, 46%, and 79% at the concentration of 0.01, 0.1, 1, and $5{\mu}M$, respectively. On the basis of these results, xanthohumol from hops (Humulus lupulus L.) showed interesting biological and pharmacological activity such as anti-oxidant effect and anti-aging.

Effect of Luteolin on the Levels of Glycoproteins During Azoxymethane-induced Colon Carcinogenesis in Mice

  • Pandurangan, Ashok Kumar;Dharmalingam, Prakash;Sadagopan, Suresh Kumar Ananda;Ganapasam, Sudhandiran
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1569-1573
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    • 2012
  • Luteolin (LUT), a bioflavonoid has been used as a chemopreventive agent world-wide against chemically induced cancer. Hence we designed an experiment to assess chemopreventive action of LUT on lipid peroxidation (LPO) and glycoconjugates in azoxymethane (AOM)-induced colon carcinogenesis. Colon cancer was induced by 15 mg/body kg. body weight of AOM and administration of LUT (at the dose of 1.2 mg/kg. body weight) was till end of the study. Analysis of lipid peroxidative end products such as protein carbonyl (PC), malonadehyde (MDA) and conjucated dienes (CD) demonstrated significant increase in in AOM-induced animals with reduction by LUT (p<0.05). Increased levels of glycoconjugates such as hexose, hexosamine, sialic acid, fucose and mucoprotein were analyzed in serum and colon tissues examined histopathologically by periodic acid Schiff's (PAS) staining were also reversed by LUT l(p<0.05). The secondary marker of colon cancer mucin depleted foci (MDF) was assessed in control and experimental group of animals. A characteristic increase of MDF was observed in AOM-induced colon cancer animals. Treatment with LUT decreased the incidence of MDF. These results suggest that LUT alters the expression of glycoconjugates and suppress colon cancer. Hence, we speculate that LUT can be used as a chemopreventive agent to treat colon cancer.

Hypoglycemic and antihyperglycemic activity of leaf extract of pluchea indica Less

  • Pramanik Kartick Chandra;Bhattacharya Plaban;Biswas Ria;Bandyopadhyay Durba;Mishra Moumita;Chatterjee TK
    • Advances in Traditional Medicine
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    • v.6 no.3
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    • pp.232-236
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    • 2006
  • The hypoglycemic and antihyperglycemic activity of methanolic extract of Pluchea indica Less. (Asteraceae) (MEPI) leaves were studied in normal rats and in streptozotocin induced diabetic rats respectively. The blood glucose levels were measured at 1, 4, 8, 16 and 24 h intervals after the treatment. The MEPI leaves showed reduction in blood glucose level in normal (35.12% and 36.01 % for 200 and 400 mg/kg, p.o. respectively) and in steptozotocin induced diabetic rats (36.10% and 41.87% for 200 and 400 mg/kg respectively). A toxicity study has been performed for the extract, which revealed that the extract is safe to use even at the doses of 3.2 gm/kg of body weight orally.

The Effect of Methamphetamine on the Regional Levels of Dopamine and Serotonin in the Rat Brain (Methamphetamine 투여가 흰쥐 뇌 부위별 dopamine, serotonin량에 미치는 영향)

  • Ro, Ihl-Hyeob;Chung, Hee-Sun
    • YAKHAK HOEJI
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    • v.34 no.5
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    • pp.311-322
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    • 1990
  • This study primarily attempted to investigate the effects of methamphetamine on stereotyped behavior. Furthermore, an extensive experiment was conducted to examine the cortex methamphetamine concentration and levels of dopamine, serotonin, and their metabolites in striatum, septum and hypothalamus. Following treatment with 10 mg/kg methamphetamine, stereotyped behavior was observed in 10 minutes. Consequently female rats displayed more intense and longer lasting activity than the male. The concentration of cortex methamphetamine was even higher in female than male. The administration of methamphetamine increased the rate of dopamine turnover-i.e. lower dopamine, higher homovanillic acid in the striatum, septum. The highest rate was found in the striatum. Methamphetamine decreased the levels of serotonin, and its metabolite of 5-indoleacetic acid in the striatum, septum. An intensity in behavioral response was accompanied by an increase in dopamine turnover, a decrease in serotonergic transmission. The reduction of 3,4-dihydroxyphenylacetic acid-i.e. the metabolite of dopamine was due not to the inhibition of monoamine oxidase but to the induction of monoamine oxidase but to the induction of catechol-O-methyltransferase. The phenomenon of biogenic amines by methamphetamine concurred upon the concentration of methamphetamine in the brain. This process preceded stereotyped behavior. After single injection of 10 mg/kg methamphetamine, the levels of biogenic amines recovered within 6 hours.

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Aphrodisiac Evaluation in Sexually Naive Male Mice after Chronic Administration of Eurycoma longifolia Jack

  • Ang, Hooi Hoon;Sim, Meng-Kwoon
    • Natural Product Sciences
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    • v.4 no.2
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    • pp.58-61
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    • 1998
  • Eurycoma longifolia Jack was evaluated for aphrodisiac property on sexually naive male mice using the electrical copulation cage. Optimum condition was provided for this study and the male mice were treated with 500 mg/kg of either chloroform, methanol, water or n-butanol fractions from E. longifolia Jack. However, the mice in the yohimbine and control groups received 30 mg/kg and 3 ml/kg of yohimbine and normal saline respectively. The male mice were then conditioned to seek either an estrous female, sexually vigorous male or no mouse, a measurement of right, wrong or no choice respectively. Besides this, hesitation time which was the time spent before the sexually naive male mice crossed the electrical grid (maintained at 0.12 mA) was also determined. Results showed that E. longifolia Jack possesses aphrodisiac property on the sexually naive male mice as shown by the slow and transient reduction in hesitation time and also a similar manner in the increase in the % of sexually naive male mice scoring right choice throughout the investigation period. Hence, this further supports the folkuse of this plant as aphrodisiac.

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Hypoglycemic Activity of Ficus racemosa L. (Moraceae) Leaves in Streptozotocin-induced Diabetic Rats

  • Mandal, Subhash C.;Mukherjee, Pulok K.;Saha, Kakali;Das, J.;Pal, M.;Saha, B.P.
    • Natural Product Sciences
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    • v.3 no.1
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    • pp.38-41
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    • 1997
  • The hypoglycemic effect of the extract of Ficus racemosa leaves was studied on streptozotocin-induced diabetic rats. Petroleum ether $(60-80^{\circ}C)$ extract of the plant obtained by soxhlet extraction from coarsely pulverised leaves was used. In the $LD_{50}$ determination of the extract no abnormalities were observed at the dose range of 3 g/kg (p.o.) of the extract. The extract (200 mg/kg and 400 mg/kg orally) caused a reduction of blood glucose levels in streptozotocin-induced diabetic rats by 28.9% (P<0.00l) and 34.6% (P<0.001) respectively at the end of 9 days. The results. of this study indicate that the petroleum ether $(60-80^{\circ}C)$ extract of the leaves possesses significant hypoglycemic activity in hyperglycemic animals compared with glybenclamide as standard drug.

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Effect on the Inhibition of Pancreatic Lipase and Lipid Metabolism of Zanthoxylum piperitum Extracts (산초 추출물의 췌장 리파아제 저해 및 지질대사에 미치는 영향)

  • Park, Jang-Soon
    • The Korean Journal of Food And Nutrition
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    • v.26 no.4
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    • pp.615-619
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    • 2013
  • Obesity is the most common nutritional disorder in the developed world and has become a global epidemic in recent years. In this study, Zanthoxylum planispinum extracts (ZPE) were evaluated on the effect on inhibition of pancreatic lipase and lipid metabolism by oral treatment for 2 months in high-fed diet obesity-induced Balb/c mice. The ZPE showed pancreatic lipase inhibitory activity with $IC_{50}$ of $0.3{\mu}g/ml$. No significant difference in feed intake was observed among the groups. The high-fat diet-treated Z. planispinum extracts groups (HFD+ZPE, 100mg/kg) significantly decreased body weight compared to the high-fat diet vehicle groups (HFD, p<0.05). The high-fat diet-treated Xenical$^{(R)}$ groups (HFD+Xenical, n=10, 30mg/kg) also showed a significant reduction of body weight compared to HFD (p<0.05). Biochemical parameters (triglyceride, total cholesterol, and high-density lipoprotein cholesterol) in HFD plus ZPE diet groups were significantly lower than those of the HFD groups (p<0.05). These results indicated that ZPE more effectively suppressed the effects of HFD on body fat gain with the inhibitory effect on pancreatic lipase.