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Sample records for carbon tetrachloride induced

  1. Hepatoprotective effect of Centella asiatica (L in carbon tetrachloride-induced liver injury in rats

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    Antony B

    2006-01-01

    Full Text Available The present study was conducted to evaluate the hepatoprotective effects of the Centella asiatica extract in carbon tetrachloride-induced liver injury in rats. Sprague Dawley rats were treated with alcohol extract of Centella asiatica orally in two doses (20 and 40 mg/kg/day for 3 mo along with intraperitoneal injection of carbon tetrachloride (1 ml/kg. Biochemical parameters such as serum total protein, albumin and marker enzymes (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were estimated both before and after the experiment. Histopathological studies of liver were also carried out to confirm the biochemical changes. Carbon tetrachloride-induced hepatotoxic effects were evident by a significant (p < 0.05 increase in the serum marker enzymes and a decrease in the total serum protein and albumin. Administration of extract of Centella asiatica effectively inhibited these changes in a dose-dependent manner; maximum effect was with 40 mg/kg. Histopathological examination of liver tissue corroborated well with the biochemical changes. Hepatic steatosis, hydropic degeneration and necrosis were observed in carbon tetrachloride-treated group, while these were completely absent in the treatment group. Centella asiatica extract exhibited hepatoprotective action against carbon tetrachloride-induced liver injury. This effect is attributed to the presence of asiaticoside (14.5% in the extract.

  2. Effect of the aqueous extract of Syzygium cumini on carbon tetrachloride-induced hepatotoxicity in rats.

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    Moresco, Rafael Noal; Sperotto, Rita Leal; Bernardi, Anie Schiavo; Cardoso, Ricardo França; Gomes, Patrícia

    2007-08-01

    The aim of this study was to evaluate the effect of the aqueous Syzygium cumini leaf extract, given either as a single dose or by 7 days of pretreatment, on hepatotoxicity induced by carbon tetrachloride in rats. Blood samples obtained after treatments were measured for aspartate aminotransferase (AST) and alanine aminotransferase (ALT). A significant increase in the AST and ALT activities occurred after carbon tetrachloride administration alone, which was significantly lowered by preadministration with the aqueous extract of Syzygium cumini, but not by a single dose. This suggests that the extract may be useful for liver protection but needs to be given over a significant period and prior to liver injury. PMID:17450508

  3. Hepatoprotective effect ofAverrhoea carambolafruit extract on carbon tetrachloride induced hepatotoxicity in mice

    Institute of Scientific and Technical Information of China (English)

    AK Azeem; Molly Mathew; Chandramohan Nair DilipC

    2010-01-01

    Objective:To investigate the hepatoprotective activity ofAverroha carambola fruit extract against carbon tetrachloride induced hepatic injury.Methods:Hepatotoxicity was induced on albino mice by intraperitoneal administration ofCCl4, half an hour after the administration of the last dose of the extract ofAverroha carambola fruit. Aqueous extract of the fruit ofAverroha carambola was administered at a dose of 0.9 g/kg body weight once daily for seven days. The hepatic injury and its prevention was assessed by the estimation of serum activities of alanine aminotransferase (ALT), aspartate aminotransferase(AST), alkaline phosphates(ALP), glutathione level and histopathological studies of liver.Results: Pre-treatment of mice with the fruit extract ofAverrhoea carambola significantly reduced serum levels ofALT, AST andALP enzyme and significantly increased the liver reduced glutathione levels24 h after the administration of carbon tetrachloride. A marked improvement in the enzyme activities and the liver reduced glutathione level was observed in the pre-treated mice 4 days after the administration of carbon tetrachloride. Histopathological studies provided supportive evidence for the biochemical analysis. Conclusions:The aqueous extract of the fruit ofAverrhoea carambola has hepatoprotective effect against carbon tetrachloride induced liver damage in mice.

  4. Attenuation of Carbon Tetrachloride-Induced Hepatotoxicity by Cow Urine Distillate in Rats

    Institute of Scientific and Technical Information of China (English)

    M PGURURAJA; A B JOSHI; HIMANSHU JOSHI; D SATHYANARAYANA; E V S SUBRAHMANYAM; K S CHANDRASHEKHAR

    2009-01-01

    Objectives To study the carbon tetrachloride-induced hepatoprotective activity in cow urine. Methods Effect of cow urine distillate on liver function was studied in vivo in rats intoxicated with carbon tetrachloride (CCl4). Hepatotoxicity was induced by a 1:1 (v/v) mixture of CCl4 in olive oil (5 mL/kg i.p). Protective effect of cow urine distillate (in three dose levels) and standard drug Silymarin (100 mg/kg, p.o) on liver function were studied in intoxicated rats. Parameters in the study included liver function tests and histological observations. Results The cow urine distillate decreased the levels of SGOT, SGPT, ALP, GGT, and total bilirubin in a dose-dependent manner (P<0.05) as sylimarin. Conclusion The observed protective effects of cow urine distillate on liver function might be due to the presence of antioxidants in cow urine.

  5. Yiguanjian decoction and its ingredients inhibit angiogenesis in carbon tetrachloride-induced cirrhosis mice

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    Zhou, Ya-Ning; Mu, Yong-Ping; Fu, Wen-Wei; Ning, Bing-Bing; Du, Guang-Li; Chen, Jia-Mei; Sun, Ming-yu; Zhang, Hua; Hu, Yi-yang; Liu, Cheng-Hai; Xu, Lie-Ming; Liu, Ping

    2015-01-01

    Background Cirrhosis is associated with angiogenesis and disruption of hepatic vascular architecture. Yiguanjian (YGJ) decoction, a prescription from traditional Chinese medicine, is widely used for treating liver diseases. We studied whether YGJ or its ingredients (iYGJ) had an anti-angiogenic effect and explored possible mechanisms underlying this process. Methods Cirrhosis was induced with carbon tetrachloride (CCl4) (ip) in C57BL/6 mice for 6 weeks. From week 4 to week 6, cirrhotic mice w...

  6. Buckwheat Honey Attenuates Carbon Tetrachloride-Induced Liver and DNA Damage in Mice

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    Ni Cheng; Liming Wu; Jianbin Zheng; Wei Cao

    2015-01-01

    Buckwheat honey, which is widely consumed in China, has a characteristic dark color. The objective of this study was to investigate the protective effects of buckwheat honey on liver and DNA damage induced by carbon tetrachloride in mice. The results revealed that buckwheat honey had high total phenolic content, and rutin, hesperetin, and p-coumaric acid were the main phenolic compounds present. Buckwheat honey possesses super DPPH radical scavenging activity and strong ferric reducing antiox...

  7. Dietary Antioxidants Effectiveness on Carbon Tetrachloride-Induced Hepatotoxicity in Adult Female Albino Rats

    International Nuclear Information System (INIS)

    Hepatic toxicity through carbon tetrachloride (CCI4) induced lipid peroxidation was extensively used in experimental models to understand the cellular mechanisms behind oxidative damage and to evaluate the therapeutic potential of drugs and dietary antioxidants. The ameliorative effect of Aloe vera juice and carrot supplementation on hepato carcinogenesis induced by carbon tetrachloride in adult female albino rats was investigated. The carcinogenic process was determined by measuring gamma-glutamyl transpeptidase (GGT), ornithine carbamyl transferase (OCT), thiobarbituric acid reactive substances (TBARs), representing levels of lipid peroxides, and carcinoembryonic antigen (CEA) in the sera of female albino rats. Carbon tetrachloride significantly elevated the serum GGT, OCT activities and the level of TBARs. Administration of Aloe vera leaf juice filtrate after CCl4 treatment resulted in a non-significant modification in GGT, OCT activities and significantly improved the level of TBARs in comparison with control. Supplementation of carrot to CCI4 treated animals led to a great amelioration in OCT activity and TBARs level, whereas GGT activity was ameliorated but statistically changed compared to control. There was a non-significant alteration in the level of CEA in all treated groups compared to normal control one

  8. Buckwheat Honey Attenuates Carbon Tetrachloride-Induced Liver and DNA Damage in Mice

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    Ni Cheng

    2015-01-01

    Full Text Available Buckwheat honey, which is widely consumed in China, has a characteristic dark color. The objective of this study was to investigate the protective effects of buckwheat honey on liver and DNA damage induced by carbon tetrachloride in mice. The results revealed that buckwheat honey had high total phenolic content, and rutin, hesperetin, and p-coumaric acid were the main phenolic compounds present. Buckwheat honey possesses super DPPH radical scavenging activity and strong ferric reducing antioxidant power. Administration of buckwheat honey for 10 weeks significantly inhibited serum lipoprotein oxidation and increased serum oxygen radical absorbance capacity. Moreover, buckwheat honey significantly inhibited aspartate aminotransferase and alanine aminotransferase activities, which are enhanced by carbon tetrachloride. Hepatic malondialdehyde decreased and hepatic antioxidant enzymes (superoxide dismutase and glutathione peroxidase increased in the presence of buckwheat honey. In a comet assay, lymphocyte DNA damage induced by carbon tetrachloride was significantly inhibited by buckwheat honey. Therefore, buckwheat honey has a hepatoprotective effect and inhibits DNA damage, activities that are primarily attributable to its high antioxidant capacity.

  9. Bioavailability of andrographolide and protection against carbon tetrachloride-induced oxidative damage in rats

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    Chen, Haw-Wen [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Huang, Chin-Shiu [Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China); Li, Chien-Chun [School of Nutrition, Chung Shan Medical University, Taichung, Taiwan (China); Department of Nutrition, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Ai-Hsuan; Huang, Yu-Ju [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Wang, Tsu-Shing [Department of Biomedical Science, Chung Shan Medical University, Taichung, Taiwan (China); Yao, Hsien-Tsung, E-mail: htyao@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Lii, Chong-Kuei, E-mail: cklii@mail.cmu.edu.tw [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan (China)

    2014-10-01

    Andrographolide, a bioactive diterpenoid, is identified in Andrographis paniculata. In this study, we investigated the pharmacokinetics and bioavailability of andrographolide in rats and studied whether andrographolide enhances antioxidant defense in a variety of tissues and protects against carbon tetrachloride-induced oxidative damage. After a single 50-mg/kg administration, the maximum plasma concentration of andrographolide was 1 μM which peaked at 30 min. The bioavailability of andrographolide was 1.19%. In a hepatoprotection study, rats were intragastrically dosed with 30 or 50 mg/kg andrographolide for 5 consecutive days. The results showed that andrographolide up-regulated glutamate cysteine ligase (GCL) catalytic and modifier subunits, superoxide dismutase (SOD)-1, heme oxygenase (HO)-1, and glutathione (GSH) S-transferase (GST) Ya/Yb protein and mRNA expression in the liver, heart, and kidneys. The activity of SOD, GST, and GSH reductase was also increased in rats dosed with andrographolide (p < 0.05). Immunoblot analysis and EMSA revealed that andrographolide increased nuclear Nrf2 contents and Nrf2 binding to DNA, respectively. After the 5-day andrographolide treatment, one group of animals was intraperitoneally injected with carbon tetrachloride (CCl{sub 4}) at day 6. Andrographolide pretreatment suppressed CCl{sub 4}-induced plasma aminotransferase activity and hepatic lipid peroxidation (p < 0.05). These results suggest that andrographolide is quickly absorbed in the intestinal tract in rats with a bioavailability of 1.19%. Andrographolide protects against chemical-induced oxidative damage by up-regulating the gene transcription and activity of antioxidant enzymes in various tissues. - Highlights: • The bioavailability of andrographolide is 1.19% in rats. • Plasma concentration reaches 1 μM after giving 50 mg/kg andrographolide. • Andrographolide up-regulates Nrf2-dependent antioxidant genes. • Andrographolide increases antioxidant defense

  10. Bioavailability of andrographolide and protection against carbon tetrachloride-induced oxidative damage in rats

    International Nuclear Information System (INIS)

    Andrographolide, a bioactive diterpenoid, is identified in Andrographis paniculata. In this study, we investigated the pharmacokinetics and bioavailability of andrographolide in rats and studied whether andrographolide enhances antioxidant defense in a variety of tissues and protects against carbon tetrachloride-induced oxidative damage. After a single 50-mg/kg administration, the maximum plasma concentration of andrographolide was 1 μM which peaked at 30 min. The bioavailability of andrographolide was 1.19%. In a hepatoprotection study, rats were intragastrically dosed with 30 or 50 mg/kg andrographolide for 5 consecutive days. The results showed that andrographolide up-regulated glutamate cysteine ligase (GCL) catalytic and modifier subunits, superoxide dismutase (SOD)-1, heme oxygenase (HO)-1, and glutathione (GSH) S-transferase (GST) Ya/Yb protein and mRNA expression in the liver, heart, and kidneys. The activity of SOD, GST, and GSH reductase was also increased in rats dosed with andrographolide (p < 0.05). Immunoblot analysis and EMSA revealed that andrographolide increased nuclear Nrf2 contents and Nrf2 binding to DNA, respectively. After the 5-day andrographolide treatment, one group of animals was intraperitoneally injected with carbon tetrachloride (CCl4) at day 6. Andrographolide pretreatment suppressed CCl4-induced plasma aminotransferase activity and hepatic lipid peroxidation (p < 0.05). These results suggest that andrographolide is quickly absorbed in the intestinal tract in rats with a bioavailability of 1.19%. Andrographolide protects against chemical-induced oxidative damage by up-regulating the gene transcription and activity of antioxidant enzymes in various tissues. - Highlights: • The bioavailability of andrographolide is 1.19% in rats. • Plasma concentration reaches 1 μM after giving 50 mg/kg andrographolide. • Andrographolide up-regulates Nrf2-dependent antioxidant genes. • Andrographolide increases antioxidant defense in various

  11. Carbon tetrachloride-induced liver injury in the rabbit.

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    Bernacchi, A. S.; de Castro, C. R.; de Ferreyra, E. C.; Villarruel, M. C.; Fernández, G.; de Fenos, O. M.; Castro, J. A.

    1983-01-01

    CCl4 administration to rabbits leads to early destruction of liver microsomal cytochrome P-450, to depression of glucose 6 phosphatase, to ultrastructurally revealable alterations and to an intense necrosis and fat accumulation in liver. Despite the known resistance of rabbit liver microsomes to lipid peroxidation, CCl4 administration to rabbits promoted lipid peroxidation of their liver microsomal lipids as revealable by the diene hyperconjugation technique, at periods of time from 1 to 12 h. Nevertheless, the intensity of this process is not equivalent to that occurring in rat liver microsomes, since the arachidonic acid content of rabbit liver microsomal lipids does not decrease at either 6 or 24 h after CCl4 administration. Rabbit liver is able to activate CCl4 to reactive metabolites that bind covalently to lipids. Relevance of covalent binding of CCl4 reactive metabolites and CCl4-promoted lipid peroxidation to CCl4-induced rabbit liver injury is analysed. Images Fig. 1 Fig. 2 PMID:6309207

  12. Hepatoprotective mechanism of lycorine against carbon tetrachloride induced toxicity in swiss albino mice - A proteomic approach

    Institute of Scientific and Technical Information of China (English)

    Soundarrajan Ilavenil; Dhanaraj Karthik; Mariadhas Valan Arasu; Mayakrishnan Vijayakumar; Srisesharam Srigopalram; Selvaraj Arokiyaraj; Sivanesan Ravikumar; Ki Choon Choi

    2015-01-01

    Objective: To investigate the differential of protein expression in CCl4 induced mice treated with lycorine. Methods: The present study was carried out to identify the differentially expressed protein in carbon tetrachloride (CCl4) induced oxidative stress mice treated with lycorine (5 mg/kg. bw) using 2D gel and MALDI-TOF. Results: We observed many kinds of differentially expressed protein in experimental liver. Among these, three are much differently expressed protein which is identified as ATP synthase, regucalcin and HSP60; these proteins are involved in the ATP synthesis, calcium regulation and rescue the integrity cellular proteins respectively. Conclusion: This investigation provided a molecular mechanism of the lycorine during CCl4 induced oxidative stress in mice liver.

  13. Hepatoprotective activity of Vitex trifolia against carbon tetrachloride-induced hepatic damage

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    Manjunatha B

    2008-01-01

    Full Text Available Aqueous and ethanol extracts of leaf of Vitex trifolia was investigated for hepatoprotective activity against carbon tetrachloride induced liver damage. To assess the hepatoprotective activity of the extracts, various biochemical parameters viz., total bilirubin, total protein, alanine transaminase, aspartate transaminase and alkaline phosphatase activities were determined. Results of the serum biochemical estimations revealed significant reduction in total bilirubin and serum marker enzymes and increase in total protein in the animals treated with ethanol and aqueous extracts. However significant rise in these serum enzymes and decrease in total protein level was noticed in CCl4 treated group indicating the hepatic damage. The hepatoprotective activity is also supported by histological studies of liver tissue. Histology of the liver tissue treated with ethanol and aqueous extracts showed normal hepatic architecture with few fatty lobules. Hence the present study revealed that Vitex trifolia could afford significant protection against CCl 4 induced hepatocellular injury.

  14. Hepatoprotective Efficacy of Cichorium intybus L. Extract Against Carbon Tetrachloride-induced Liver Damage in Rats.

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    Elgengaihi, Souad; Mossa, Abdel-Tawab H; Refaie, Amel A; Aboubaker, Doha

    2016-01-01

    The purpose of the study was to assess the phytochemical and hepatoprotective activity of different extracts of dried herb of Cichorium intybus L. against carbon tetrachloride (CCl4) intoxicated male albino rats. The hepatoprotective activity of different extracts at 500 mg/kg body weight was compared with carbon tetrachloride-treated animals. The animals were divided into five groups with six animals in each group. The first group represents control, the second group received carbon tetrachloride, the third received C. intybus, and the fourth group received C. intybus plus carbon tetrachloride. The fifth group received silymarin as hepato-slandered drug. There were significant changes in serum biochemical parameters such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, albumin, total protein, and γ-glutamyl transferase (GGT) in carbon tetrachloride intoxicated rats, which were restored towards normal values in C. intybus-treated animals. Histopathological examination of liver tissues further substantiated these findings. In conclusion, of this investigation, the results ascertain that the herb extracts of C. intybus possess significant hepatoprotective activity. PMID:26913368

  15. Bioavailability of andrographolide and protection against carbon tetrachloride-induced oxidative damage in rats.

    Science.gov (United States)

    Chen, Haw-Wen; Huang, Chin-Shiu; Li, Chien-Chun; Lin, Ai-Hsuan; Huang, Yu-Ju; Wang, Tsu-Shing; Yao, Hsien-Tsung; Lii, Chong-Kuei

    2014-10-01

    Andrographolide, a bioactive diterpenoid, is identified in Andrographis paniculata. In this study, we investigated the pharmacokinetics and bioavailability of andrographolide in rats and studied whether andrographolide enhances antioxidant defense in a variety of tissues and protects against carbon tetrachloride-induced oxidative damage. After a single 50-mg/kg administration, the maximum plasma concentration of andrographolide was 1μM which peaked at 30min. The bioavailability of andrographolide was 1.19%. In a hepatoprotection study, rats were intragastrically dosed with 30 or 50mg/kg andrographolide for 5 consecutive days. The results showed that andrographolide up-regulated glutamate cysteine ligase (GCL) catalytic and modifier subunits, superoxide dismutase (SOD)-1, heme oxygenase (HO)-1, and glutathione (GSH) S-transferase (GST) Ya/Yb protein and mRNA expression in the liver, heart, and kidneys. The activity of SOD, GST, and GSH reductase was also increased in rats dosed with andrographolide (p<0.05). Immunoblot analysis and EMSA revealed that andrographolide increased nuclear Nrf2 contents and Nrf2 binding to DNA, respectively. After the 5-day andrographolide treatment, one group of animals was intraperitoneally injected with carbon tetrachloride (CCl4) at day 6. Andrographolide pretreatment suppressed CCl4-induced plasma aminotransferase activity and hepatic lipid peroxidation (p<0.05). These results suggest that andrographolide is quickly absorbed in the intestinal tract in rats with a bioavailability of 1.19%. Andrographolide protects against chemical-induced oxidative damage by up-regulating the gene transcription and activity of antioxidant enzymes in various tissues. PMID:25110055

  16. Phytochemical and Pharmacological Standardisation of Polyherbal Tablets For Hepatoprotective Activity Against Carbon Tetrachloride Induced Hepatotoxicity

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    Vilas A. Arsul

    2010-10-01

    Full Text Available Literature survey revealed that phyllanthin and hypophyllanthin from Phyllanthus niruri, wedenolactone from Eclipta alba, and kutkin from Picrorhiza kurroa are responsible for hepatoprotective activity, and phenolic and flavonoids are responsible for antioxidant activity. A selected polyherbal formulation composed of 7 herbal extract mixtures such as Phyllanthus niruri, Eclipta alba, Cichorium intybus, Boerhaavia diffusa, Embelia ribes, Berberis aristata and Picrorhiza kurroa. The phytochemical evaluation was carried out by estimation of total phenolic content and total flavonoids. The antioxidant activity was compared with ascorbic acid (ASC and Rutin as standard. The hepatoprotective activity in carbon tetrachloride induced hepatotoxicity were studied. Assessment of liver function was made by estimating the activities of SGOT, SGPT, ALP, Cholesterol, Bilirubin and Total protein. From the study it is seen that formulation exhibit significant activity.

  17. Hepatoprotective effect of Vernonia cinerea and Cumin seeds on Carbon Tetrachloride Induced Hepatic Oxidative Stress

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    A. Nishadh

    2013-09-01

    Full Text Available In this study, we have examined the protective effect of Vernonia cinerea against carbon tetrachloride (1.0ml / kg b.wt / day administered intraperitoneally for 2 days in male albino Wistar rats. The levels of aspartate transaminase, alanine transaminase, lactate dehydrogenase, alkaline phosphatase, bilirubin, creatinine, and urea were determined. The activities of glutathione, Vitamin C and the levels of lipid peroxides in 10% w/v liver homogenate were also determined. The CCl4 induction resulted a significant elevation in the levels of serum marker enzymes, bilirubin and creatinine with decreased urea. The activities of hepatic glutathione and vitamin C were also significantly depleted with increased lipid peroxides in CCl4 intoxicated rats. The oral administration of herbal drug alone did not show any toxicity in the liver tissue. These results suggest that the herbal drug may probably act as a natural antioxidant against CCl4 induced hepatic oxidative stress.

  18. Hepatoprotective and antioxidant activity of pentagamavunon-0 against carbon tetrachloride-induced hepatic injury in rats

    Institute of Scientific and Technical Information of China (English)

    Arief Nurrochmad; Supardjan Amir Margono; Sardjiman; Arief Rahman Hakim; Ernawati; Erna Kurniawati; Erva Fatmawati

    2013-01-01

    Objective: To investigate the hepatoprotective and antioxidant activity of pentagamavunon-0(PGV-0) against CCl4-induced hepatic injury in rats. Methods: The groups of animals were administered with PGV-0 at the doses 2.5, 5, 10, and 20 mg/kg b.w., p.o. once in a day for 6 days and at day 7 the animals were administrated with carbon tetrachloride (CCl4) (20%, 2 mL/kg b.w. in liquid paraffin (i.p.). The effect of PGV-0 on serum transaminase (SGPT), alkaline phosphates (ALP) and total bilirubin were determined in CCl4-induced hepatotoxicity in rats. Further, the effects of PGV-0 on glutathione (GSH) content, catalase (CAT) and NO free radical scavenging activity also were investigated. Results: The results demonstrated that PGV-0 significantly reduced the activity of SGPT, serum ALP and total bilirubin in CCl4 induced rat hepatotoxicity. PGV-0 has effect on the antioxidant and free radical defense system. It prevented the depletion level of GSH and decrease activity of CAT in CCl4-induced liver injury in rats. PGV-0 also demonstrated the free radical scavenger effects on NO free radical scavenging activity with ES value of 32.32 μM. Conculsion: All of our findings suggests that PGV-0 could protect the liver cells from CCl4-induced liver damages and the mechanism may through the antioxidative effect of PGV-0 to prevent the accumulation of free radicals and protect the liver damage.

  19. Carbon tetrachloride-induced hepatotoxicity: Protective effect of 'Rocket' Eruca sativa L. in rats.

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    Alqasoumi, Saleh

    2010-01-01

    The hepatoprotective and antioxidant effect of an ethanolic extract of 'Rocket' Eruca sativa L. (EER), on liver injury induced by carbon tetrachloride (CCl(4)) was investigated. Wistar albino rats were administered 250 and 500 mg/kg body weight extract orally for 10 consecutive days. Marker enzymes GOT, GPT, ALP, GGT and bilirubin were estimated in serum. Whereas, non-protein sulfhydryl (NP-SH), total protein (TP) and malondialdehyde (MDA) were estimated in liver tissue as markers for oxidative stress. Histopathological assessment was also done on liver tissue. CCl(4) induced liver poisoning in all treated animals was evident by elevated serum GOT, GPT, ALP, GGT and bilirubin levels. Induction of oxidative stress in the liver tissue by CCl(4) was evidenced by a fall in the levels of NP-SH and TP; and an increased level of MDA concentration. EER administration for 10 days prevented the CCl(4) induced hepatic injury and oxidative stress. Furthermore, the extract also reduced the pentobarbital-induced prolongation of sleeping time in mice. The ability of rocket extract to protect the liver toxicity in rats was further confirmed by histological findings in the liver tissue. In conclusion, it was observed that Eruca sativa L. extract protects the liver against CCl(4) induced hepatic injury through its potent antioxidant activity in rats.

  20. Total Flavonoids from Mimosa Pudica Protects Carbon Tetrachloride -Induced Acute Liver Injury in Mice

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    Zhen-qin QIU

    2015-03-01

    Full Text Available Objective: To observe the protective effect of total flavonoids from Mimosa pudica on carbon tetrachloride (CCl4-induced acute liver injury in mice. Methods: CCl4-induced acute liver injury model in mice was established. The activity of ALT and AST, the content of serum albumin (Alb and total antioxidant capacity (T-AOC were determined. The content of malondiadehyde (MDA was measured and the activity of superoxide dismutase (SOD was determined. The histopathological changes of liver were observed.Results: Compared with CCl4 modle group, each dose group of total flavonouida from Mimosa pudica couldreduced the activity of ALT and AST in mice obviously (P<0.01, indicating they had remarkably protective effect on CCl4-induced acute liver injury in mice. high and middle dose groups of total flavonouida from Mimosa pudica couldincrease the content of Alb in mice (P<0.01. Each dose group of total flavonouida from Mimosa pudica could enhance the level of T-AOC (P<0.01. each dose group of total flavonouida from Mimosa pudica could lower the content of liver homogenate MDA but enhance the activity of SOD in a dose-depended manner (P<0.01. Conclusion: Total flavones from Mimosa Pudica have obvious protective effect on CCl4-induced acute liver injury in mice.

  1. Efficient amelioration of carbon tetrachloride induced toxicity in isolated rat hepatocytes by Syzygium cumini Skeels extract.

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    Veigas, Jyothi M; Shrivasthava, Richa; Neelwarne, Bhagyalakshmi

    2008-09-01

    Syzygium cumini, Indian black plum or Java plum, is a rich source for anthocyanins (230 mg/100g DW) showing high antioxidant activity in vitro. In the following study it is further demonstrated that S. cumini peel extract rich in anthocyanins (SCA) offers considerable protection against carbon tetrachloride (CCl(4))-induced damage in rat hepatocytes. SCA itself being non-toxic to primary rat hepatocytes at concentrations ranging from 50 to 500 ppm, was found to suppress CCl(4)-induced LDH leakage by 54% at 50ppm, thereby improving the cell viability by 39%. The SCA significantly reversed the CCl(4) induced changes in cellular glutathione (GSH) level, lipid peroxidation and activity of the antioxidant enzyme glutathione peroxidase. Exposure of hepatocytes to SCA after CCl(4) treatment was found to elevate GSH and GPx activities by 2-folds, whereas the activities of catalase and superoxide dismutase were not significantly affected. The fruit pulp extract (SPE) was less effective in offering protection to rat hepatocytes, particularly in terms of total GSH content and a consequent increase in lipid peroxidation although the higher GPx activity suggests the probable involvement of GSH as a substrate for GPx. These observations suggest that the fruit peel extract of S. cumini, is largely responsible for the reversal of CCl(4)-induced oxidative damage in rat hepatocytes. Both peel and pulp extract appear to offer protection to rat hepatocytes through GPx along with other biological pathways independent of catalase and superoxide dismutase. PMID:18538978

  2. Protection effect of kallistatin on carbon tetrachloride-induced liver fibrosis in rats via antioxidative stress.

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    Xiaoping Huang

    Full Text Available Prolonged inflammation and oxidative stress are emerging as key causes of pathological wound healing and the development of liver fibrosis. We have investigated the effects of recombinant human kallistatin, produced in Pichia. pastoris, on preventing carbon tetrachloride (CCl4-induced liver fibrosis in rats. Daily administration of kallistatin prevented development of CCl4-induced liver fibrosis, which was evidenced by histological study. In all kallistatin treated rats, activation of hepatic stellate cells (HSC as assessed by s-smooth muscle actin staining was attenuated, TGF- β1 expression was inhibited, class I serum biomarkers associated with the process of fibrogenesis, such as hyaluronic acid, laminin, and procollagen III, were lowered, compared with that in the model control group. Furthermore, residual hepatic functional reserve was improved by kallistatin treatment. CCl4 induced elevation of malondialdehyde level and reduced superoxide dismutase activity in the liver, while kallistatin reduced these oxidative parameters. We also investigated the effects of kallistatin on rat primary HSC and LX-2, the human HSC cell line. Kallistatin scavenged H2O2-induced ROS in the LX-2 cells, and suppressed the activation of primary HSC. These results suggest recombinant human kallistatin might be a promising drug candidate for therapeutic intervention of liver fibrosis.

  3. Protection Effect of Kallistatin on Carbon Tetrachloride-Induced Liver Fibrosis in Rats via Antioxidative Stress

    Science.gov (United States)

    Huang, Xiaoping; Wang, Xiao; Lv, Yinghui; Xu, Luli; Lin, Junsheng; Diao, Yong

    2014-01-01

    Prolonged inflammation and oxidative stress are emerging as key causes of pathological wound healing and the development of liver fibrosis. We have investigated the effects of recombinant human kallistatin, produced in Pichia. pastoris, on preventing carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Daily administration of kallistatin prevented development of CCl4-induced liver fibrosis, which was evidenced by histological study. In all kallistatin treated rats, activation of hepatic stellate cells (HSC) as assessed by s-smooth muscle actin staining was attenuated, TGF- β1 expression was inhibited, class I serum biomarkers associated with the process of fibrogenesis, such as hyaluronic acid, laminin, and procollagen III, were lowered, compared with that in the model control group. Furthermore, residual hepatic functional reserve was improved by kallistatin treatment. CCl4 induced elevation of malondialdehyde level and reduced superoxide dismutase activity in the liver, while kallistatin reduced these oxidative parameters. We also investigated the effects of kallistatin on rat primary HSC and LX-2, the human HSC cell line. Kallistatin scavenged H2O2-induced ROS in the LX-2 cells, and suppressed the activation of primary HSC. These results suggest recombinant human kallistatin might be a promising drug candidate for therapeutic intervention of liver fibrosis. PMID:24558397

  4. Hepatoprotective effect of pinoresinol on carbon tetrachloride-induced hepatic damage in mice.

    Science.gov (United States)

    Kim, Hyo-Yeon; Kim, Joon-Ki; Choi, Jun-Ho; Jung, Joo-Yeon; Oh, Woo-Yong; Kim, Dong Chun; Lee, Hee Sang; Kim, Yeong Shik; Kang, Sam Sik; Lee, Seung-Ho; Lee, Sun-Mee

    2010-01-01

    Forsythiae Fructus is known to have diuretic, anti-bacterial, and anti-inflammatory activities. This study examined the hepatoprotective effects of pinoresinol, a lignan isolated from Forsythiae Fructus, against carbon tetrachloride (CCl(4))-induced liver injury. Mice were treated intraperitoneally with vehicle or pinoresinol (25, 50, 100, and 200 mg/kg) 30 min before and 2 h after CCl4 (20 microl/kg) injection. In the vehicle-treated CCl(4 )group, serum aminotransferase activities were significantly increased 24 h after CCl4 injection, and these increases were attenuated by pinoresinol at all doses. Hepatic glutathione contents were significantly decreased and lipid peroxidation was increased after CCl4 treatment. These changes were attenuated by 50 and 100 mg/kg of pinoresinol. The levels of protein and mRNA expression of inflammatory mediators, including tumor necrosis factor-alpha, inducible nitric oxide synthase, and cyclooxygenase-2, were significantly increased after CCl4 injection; and these increases were attenuated by pinoresinol. Nuclear translocation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of c-Jun, one of the components of activating protein 1 (AP-1), were inhibited by pinoresinol. Our results suggest that pinoresinol ameliorates CCl4)-induced acute liver injury, and this protection is likely due to anti-oxidative activity and down-regulation of inflammatory mediators through inhibition of NF-kappaB and AP-1.

  5. Protective effects of polydatin from Polygonum cuspidatum against carbon tetrachloride-induced liver injury in mice.

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    Hong Zhang

    Full Text Available Polydatin is one of main compounds in Polygonum cuspidatum, a plant with both medicinal and nutritional value. The possible hepatoprotective effects of polydatin on acute liver injury mice induced by carbon tetrachloride (CCl(4 and the mechanisms involved were investigated. Intraperitoneal injection of CCl(4 (50 µl/kg resulted in a significant increase in the levels of serum aspartate aminotransferase (AST, alanine aminotransferase (ALT and hepatic malondialdehyde (MDA, also a marked enhancement in the expression of hepatic tumor necrosis factor-alpha (TNF-α, interleukin-1 beta (IL-1β, cyclooxygenase-2 (COX-2, inducible nitric oxide synthase (iNOS and nuclearfactor-kappa B (NF-κB. On the other hand, decreased glutathione (GSH content and activities of glutathione transferase (GST, superoxide dismutase (SOD, catalase (CAT and glutathione peroxidase (GPx were observed following CCl(4 exposure. Nevertheless, all of these phenotypes were evidently reversed by preadministration of polydatin for 5 continuous days. The mRNA and protein expression levels of hepatic growth factor-beta1 (TGF-β(1 were enhanced further by polydatin. These results suggest that polydatin protects mice against CCl(4-induced liver injury through antioxidant stress and antiinflammatory effects. Polydatin may be an effective hepatoprotective agent and a promising candidate for the treatment of oxidative stress- and inflammation-related diseases.

  6. Calretinin immunoreactivity in normal and carbon tetrachloride-induced nephrotoxic rats.

    Science.gov (United States)

    Kang, Ki Young; Kim, Jin Nam; Chang, In Youb; Park, Sung Ho; Yoon, Sang Pil

    2011-11-01

    Carbon tetrachloride (CCl(4)) is a potent hepatotoxic and nephrotoxic chemical. Little, however, is known about the association of CCl(4)-induced nephrotoxicity and calretinin. We hypothesized that calretinin might be localized in the proximal tubule cells and play a role against CCl(4)-induced nephrotoxicity, since the target of CCl(4) is the brush border-bearing tubule cells. CCl(4) (1 ml/kg) was administrated by oral gavage to 8-week old male Sprague-Dawley rats once a week for 4 weeks. A significant increase in serum blood urea nitrogen and creatinine was confirmed by serum analysis. Calretinin immunolocalization was compared with the calbindin D-28k immunoreactivity in normal and CCl(4)-treated kidneys. Calretinin was clearly immunolocalized in the apical surface of proximal convoluted tubule in the deeper cortex of normal kidney and blurred after CCl(4) administration, with only minor changes of calbindin D-28k immunoreactivity in the distal convoluted tubules and collecting ducts, irrelevant to the CCl(4) treatment. These findings might have significance since decreased immunolocalization of calretinin with CCl(4)-induced nephrotoxicity may contribute to the toxicity-related decrease in calcium transport or calcium buffering activity in the kidney. PMID:20947139

  7. In vitro and in vivo protective effects of proteoglycan isolated from mycelia of Ganoderma lucidum on carbon tetrachloride-induced liver injury

    OpenAIRE

    Yang, Xiao-Jun; Liu, Jing; Ye, Lin-Bai; Yang, Fan; Ye, Li; Gao, Jin-Rong; Wu, Zheng-Hui

    2006-01-01

    AIM: To investigate the possible mechanism of the protective effects of a bioactive fraction, Ganoderma lucidum proteoglycan (GLPG) isolated from Ganoderma lucidum mycelia, against carbon tetrachloride-induced liver injury.

  8. Role of the sympathetic nervous system in carbon tetrachloride-induced hepatotoxicity and systemic inflammation.

    Directory of Open Access Journals (Sweden)

    Jung-Chun Lin

    Full Text Available Carbon tetrachloride (CCl4 is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2, and tumor necrosis factor-α (TNF-α], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response.

  9. Carbon tetrachloride-induced kidney damage and protective effect of Amaranthus lividus L. in rats.

    Science.gov (United States)

    Yilmaz-Ozden, Tugba; Can, Ayse; Karatug, Ayse; Pala-Kara, Zeliha; Okyar, Alper; Bolkent, Sehnaz

    2016-06-01

    This study was designed to evaluate the protective effect of water extract of Amaranthus lividus L. (A. lividus) (Amaranthaceae) on carbon tetrachloride (CCl4)-induced toxicity in kidneys of rats. For this purpose, male albino Wistar rats were pretreated with A. lividus (250 and 500 mg/kg body weight (b.w.)) daily for 9 days and a single dose of CCl4 was applied intraperitoneally (50% in olive oil; 1.5 mL/kg b.w.) on the 10th day. All rats were killed 24 h after CCl4 administration, and kidneys were excised and used for determination of histopathological and biochemical parameters. CCl4 administration caused a remarkable increase in lipid peroxidation (LPO) and glutathione levels and glutathione-S-transferase, glutathione peroxidase, glutathione reductase, superoxide dismutase, myeloperoxidase (MPO) activities and a decrease in catalase (CAT) activity when compared to the control group. Pretreatment with A. lividus (250 and 500 mg/kg b.w.) significantly prevented the elevation in LPO level and MPO activity as well as protected the decrease in CAT activity but did not alter other biochemical parameters. The protective effect of A. lividus was further evident through the decreased histological alterations in kidneys. In conclusion, this study has indicated that A. lividus possesses protective and antioxidant effects against CCl4-induced oxidative kidney damage. PMID:25415872

  10. Phytochemical analysis and hepatoprotective properties of Tinospora cordifolia against carbon tetrachloride-induced hepatic damage in rats

    OpenAIRE

    Kavitha, B. T.; Shruthi, S. D.; Rai, S. Padmalatha; Ramachandra, Y. L.

    2011-01-01

    The present study was conducted to evaluate the hepatoprotective activity of different extracts of Tinospora cordifolia against carbon tetrachloride (CCl4) induced liver damage in rats. The pet ether, ethanol and aqueous extracts of various parts of the plant such as leaf, stem and root were tested at the dose of 200mg/kg body weight orally using Wistar albino rats and Silymarin was given as reference standard. Ethanolic extract of all the parts showed significant hepatoprotective effect by r...

  11. Protective Effect of Ssanghwa-Tang Fermented by Lactobacillus Fermentum Against Carbon Tetrachloride-Induced Acute Hepatotoxicity in Rats

    OpenAIRE

    Eum, Hyun-Ae; Lee, Ji-Hye; Yang, Min-Cheol; Shim, Ki Shuk; Lee, Jae-Hoon; Ma, Jin Yeul

    2011-01-01

    Ssanghwa-tang (SHT) is a traditional herbal medicine formula that has been used for the development of physical strength, relief of pain, and the reduction of fatigue. In this study, we fermented SHT with Lactobacillus fermentum (L. fermentum), Lactobacillus gasseri (L.gasseri), or Lactobacillus casei (L.casei) to investigate the hepatoprotective effects of SHT and fermented SHT with Lactobacillus on carbon tetrachloride (CCl4)-induced liver injury in rats. Rats were given CCl4 (1 ml/kg, 50% ...

  12. Protective Effect of the Total Saponins from Rosa laevigata Michx Fruit against Carbon Tetrachloride-Induced Liver Fibrosis in Rats

    OpenAIRE

    Deshi Dong; Lianhong Yin; Yan Qi; Lina Xu; Jinyong Peng

    2015-01-01

    In this study, the protective effect of the total saponins from Rosa laevigata Michx (RLTS) against liver fibrosis induced by carbon tetrachloride (CCl4) in rats was evaluated. The results showed that RLTS significantly rehabilitated the levels of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, glutathione, glutathione peroxidase, catalase, superoxide dismutase, hydroxyproline, α-smooth muscle actin, collagen I, collagen III and fibronectin, which were confirmed using ...

  13. Systemic inflammatory response syndrome (SIRS) induced by carbon tetrachloride in rats

    OpenAIRE

    Gergely, J.; Sipka, S; Csípo, J.; Udvardy, M.; Gy. Szegedi; Kulcsár, A.

    1997-01-01

    We have observed the symptoms of systemic inflammatory response syndrome (SIRS) in male rats intoxicated by carbon tetrachloride (CCl4). Severe hypothermia, tachypnoea and increase in the heart beat min were diagnosed. These symptoms developed in the first hour of intoxication. The hepatic dysfunction was characterized by elevated bilirubin levels. In the sera we have measured increases in the activity of secretable (group II) phospholipase A2 sPLA2 (2,8x) and 6-ketoprostaglandin F1α (KPGF) (...

  14. Phenylbutyric acid protects against carbon tetrachloride-induced hepatic fibrogenesis in mice

    International Nuclear Information System (INIS)

    A recent report showed that the unfolded protein response (UPR) signaling was activated in the pathogenesis of carbon tetrachloride (CCl4)-induced hepatic fibrosis. Phenylbutyric acid (PBA) is a well-known chemical chaperone that inhibits endoplasmic reticulum (ER) stress and unfolded protein response (UPR) signaling. In the present study, we investigated the effects of PBA on CCl4-induced hepatic fibrosis in mice. All mice were intraperitoneally (i.p.) injected with CCl4 (0.15 ml/kg BW, twice per week) for 8 weeks. In CCl4 + PBA group, mice were i.p. injected with PBA (150 mg/kg, twice per day) from the beginning of CCl4 injection to the end. As expected, PBA significantly attenuated CCl4-induced hepatic ER stress and UPR activation. Although PBA alleviated, only to a less extent, hepatic necrosis, it obviously inhibited CCl4-induced tumor necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β). Moreover, PBA inhibited CCl4-induced hepatic nuclear factor kappa B (NF-κB) p65 translocation and extracellular signal-regulated kinase (ERK) and c-Jun N-terminal Kinase (JNK) phosphorylation. Interestingly, CCl4-induced α-smooth muscle actin (α-SMA), a marker for the initiation phase of HSC activation, was significantly attenuated in mice pretreated with PBA. Correspondingly, CCl4-induced hepatic collagen (Col)1α1 and Col1α2, markers for the perpetuation phase of HSC activation, were inhibited in PBA-treated mice. Importantly, CCl4-induced hepatic fibrosis, as determined using Sirius red staining, was obviously attenuated by PBA. In conclusion, PBA prevents CCl4-induced hepatic fibrosis through inhibiting hepatic inflammatory response and HSC activation. Highlights: ► CCl4 induces hepatic ER stress, inflammation, HSC activation and hepatic fibrosis. ► PBA alleviates CCl4-induced hepatic ER stress and UPR signaling activation. ► PBA inhibits CCl4-induced hepatic NF-κB activation and ERK and JNK phosphorylation. ► PBA effectively protects

  15. Phenylbutyric acid protects against carbon tetrachloride-induced hepatic fibrogenesis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian-Qing [School of Pharmacy, Anhui Medical University, Hefei, 230032 (China); Second Affiliated Hospital, Anhui Medical University, Hefei 230601 (China); Chen, Xi [First Affiliated Hospital, Anhui Medical University, Hefei 230022 (China); Zhang, Cheng [Department of Toxicology, Anhui Medical University, Hefei, 230032 (China); Tao, Li [First Affiliated Hospital, Anhui Medical University, Hefei 230022 (China); Zhang, Zhi-Hui; Liu, Xiao-Qian [Department of Toxicology, Anhui Medical University, Hefei, 230032 (China); Xu, Yuan-Bao [Department of Toxicology, Anhui Medical University, Hefei, 230032 (China); First Affiliated Hospital, Anhui Medical University, Hefei 230022 (China); Wang, Hua [Department of Toxicology, Anhui Medical University, Hefei, 230032 (China); Li, Jun, E-mail: lijun@ahmu.edu.cn [School of Pharmacy, Anhui Medical University, Hefei, 230032 (China); Xu, De-Xiang, E-mail: xudex@126.com [Department of Toxicology, Anhui Medical University, Hefei, 230032 (China)

    2013-01-15

    A recent report showed that the unfolded protein response (UPR) signaling was activated in the pathogenesis of carbon tetrachloride (CCl{sub 4})-induced hepatic fibrosis. Phenylbutyric acid (PBA) is a well-known chemical chaperone that inhibits endoplasmic reticulum (ER) stress and unfolded protein response (UPR) signaling. In the present study, we investigated the effects of PBA on CCl{sub 4}-induced hepatic fibrosis in mice. All mice were intraperitoneally (i.p.) injected with CCl{sub 4} (0.15 ml/kg BW, twice per week) for 8 weeks. In CCl{sub 4} + PBA group, mice were i.p. injected with PBA (150 mg/kg, twice per day) from the beginning of CCl{sub 4} injection to the end. As expected, PBA significantly attenuated CCl{sub 4}-induced hepatic ER stress and UPR activation. Although PBA alleviated, only to a less extent, hepatic necrosis, it obviously inhibited CCl{sub 4}-induced tumor necrosis factor alpha (TNF-α) and transforming growth factor beta (TGF-β). Moreover, PBA inhibited CCl{sub 4}-induced hepatic nuclear factor kappa B (NF-κB) p65 translocation and extracellular signal-regulated kinase (ERK) and c-Jun N-terminal Kinase (JNK) phosphorylation. Interestingly, CCl{sub 4}-induced α-smooth muscle actin (α-SMA), a marker for the initiation phase of HSC activation, was significantly attenuated in mice pretreated with PBA. Correspondingly, CCl{sub 4}-induced hepatic collagen (Col)1α1 and Col1α2, markers for the perpetuation phase of HSC activation, were inhibited in PBA-treated mice. Importantly, CCl{sub 4}-induced hepatic fibrosis, as determined using Sirius red staining, was obviously attenuated by PBA. In conclusion, PBA prevents CCl{sub 4}-induced hepatic fibrosis through inhibiting hepatic inflammatory response and HSC activation. Highlights: ► CCl{sub 4} induces hepatic ER stress, inflammation, HSC activation and hepatic fibrosis. ► PBA alleviates CCl{sub 4}-induced hepatic ER stress and UPR signaling activation. ► PBA inhibits CCl{sub 4}-induced

  16. Liquiritigenin Protects Rats from Carbon Tetrachloride Induced Hepatic Injury through PGC-1α Pathway

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    Yiping Zhang

    2015-01-01

    Full Text Available The lack of effective treatment for liver cirrhosis and hepatocellular carcinomas imposes serious challenges to the healthcare system. Here, we investigated the efficacy and mechanism of liquiritigenin involved in preventing or retarding the progression of liver diseases in a rat model with chronic carbon tetrachloride (CCl4 exposure. Sprague Dawley rats were given CCl4 and lliquiritigenin alone or simultaneously for 8 weeks before liver was harvested to check histological changes by Hematoxylin and Eosin (H&E staining, apoptosis by TUNEL assay, ROS by dihydroethidium staining, antioxidant enzyme activities and malondialdehyde using specific kits, and gene expression by quantitative real-time PCR and western blot. Chronic CCl4 exposure caused profound changes in liver histology with extensive hepatocyte death (necrosis and apoptosis, fat accumulation, and infiltration of inflammatory cells, accompanied by depressed activities of antioxidant enzymes, increased oxidative stress, elevated expression of inflammation and fibrotic genes, and downregulation of PGC-1α, ND1, and Bcl-x in rat liver. All these changes were abolished or alleviated by lliquiritigenin. The results demonstrated that liquiritigenin is effective in protecting liver from injury or treating chronic liver diseases. The modulation of PGC-1α and its downstream genes might play a critical role in relieving CCl4-induced hepatic pathogenesis by liquiritigenin.

  17. Hydrogen sulfide attenuates carbon tetrachloride-induced hepatotoxicity, liver cirrhosis and portal hypertension in rats.

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    Gang Tan

    Full Text Available BACKGROUND: Hydrogen sulfide (H(2S displays vasodilative, anti-oxidative, anti-inflammatory and cytoprotective activities. Impaired production of H(2S contributes to the increased intrahepatic resistance in cirrhotic livers. The study aimed to investigate the roles of H(2S in carbon tetrachloride (CCl(4-induced hepatotoxicity, cirrhosis and portal hypertension. METHODS AND FINDINGS: Sodium hydrosulfide (NaHS, a donor of H(2S, and DL-propargylglycine (PAG, an irreversible inhibitor of cystathionine γ-lyase (CSE, were applied to the rats to investigate the effects of H(2S on CCl(4-induced acute hepatotoxicity, cirrhosis and portal hypertension by measuring serum levels of H(2S, hepatic H(2S producing activity and CSE expression, liver function, activity of cytochrome P450 (CYP 2E1, oxidative and inflammatory parameters, liver fibrosis and portal pressure. CCl(4 significantly reduced serum levels of H(2S, hepatic H(2S production and CSE expression. NaHS attenuated CCl(4-induced acute hepatotoxicity by supplementing exogenous H(2S, which displayed anti-oxidative activities and inhibited the CYP2E1 activity. NaHS protected liver function, attenuated liver fibrosis, inhibited inflammation, and reduced the portal pressure, evidenced by the alterations of serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, hyaluronic acid (HA, albumin, tumor necrosis factor (TNF-α, interleukin (IL-1β, IL-6 and soluble intercellular adhesion molecule (ICAM-1, liver histology, hepatic hydroxyproline content and α-smooth muscle actin (SMA expression. PAG showed opposing effects to NaHS on most of the above parameters. CONCLUSIONS: Exogenous H(2S attenuates CCl(4-induced hepatotoxicity, liver cirrhosis and portal hypertension by its multiple functions including anti-oxidation, anti-inflammation, cytoprotection and anti-fibrosis, indicating that targeting H(2S may present a promising approach, particularly for its prophylactic effects, against liver

  18. Chemopreventive Effect of Cinnamon Extract on Carbon Tetrachloride-Induced Physiological Changes in the Frog, Rana ridibunda

    Science.gov (United States)

    Al-Attar, Atef M.

    The present study examined the preventive influences of an aqueous extract of cinnamon on carbon tetrachloride-induced some physiological alterations in the frog, Rana ridibunda. The experimental animals were divided into five batches. The first batch was untreated and served as control. The other batches were treated for 6 weeks with carbon tetrachloride, cinnamon extract plus carbon tetrachloride, cinnamon and corn oil, respectively. Haematological, biochemical and hepatosomatic index indices were chosen as physiological indicators. These parameters were evaluated at 2, 4 and 6 weeks. In comparison with control and cinnamon plus CCl4 batches, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, mean corpuscular haemoglobin concentration and increases of glutamic pyruvic acid transaminase values were noted in CCl4-exposed batch at all experimental periods. Also, glutamic oxaloacetic acid transaminase and hepatosomatic index levels were significantly elevated, while mean corpuscular haemoglobin values were decreased at second and last periods. Mean cell volume values were only increased at the first period. In comparison with control batch, significant decreases of red blood cell count, haemoglobin concentration, haematocrit, and increases of glutamic oxaloacetic acid transaminase, glutamic pyruvic acid transaminase and hepatosomatic index values were observed in frogs treated with cinnamon plus CCl4 at 2 and 6 weeks. Mean cell volume and mean corpuscular haemoglobin values were statistically elevated at second period. Mean corpuscular haemoglobin concentration values were declined at last period. Moreover, the percentage changes of these parameters in cinnamon plus CCl4 batch tended to be lower than CCl4 treated the experimental animals. In addition, it is conceivable therefore, that the cinnamon aqueous extract exhibits a protective influence against carbon tetrachloride-induced some physiological changes, probably mediated

  19. Hepatoprotective effects of berberine on carbon tetrachloride-induced acute hepatotoxicity in rats

    OpenAIRE

    Feng Yibin; Siu Ka-Yu; Ye Xingshen; Wang Ning; Yuen Man-Fung; Leung Chung-Hang; Tong Yao; Kobayashi Seiichi

    2010-01-01

    Abstract Background Berberine is an active compound in Coptidis Rhizoma (Huanglian) with multiple pharmacological activities including antimicrobial, antiviral, anti-inflammatory, cholesterol-lowering and anticancer effects. The present study aims to determine the hepatoprotective effects of berberine on serum and tissue superoxide dismutase (SOD) levels, the histology in tetrachloride (CCl4)-induced liver injury. Methods Sprague-Dawley rats aged seven weeks were injected intraperitoneally wi...

  20. Response Pattern of Antioxidants to Lipid Peroxide Concentration in Carbon Tetrachloride-Induced Hepato-Toxicity Is Tightly Logistic in Rabbits

    OpenAIRE

    Alisi C. S.; Ojiako O. A.; Osuagwu C. G.; Onyeze G. O. C.

    2011-01-01

    Logistic response of antioxidants to lipid peroxide concentration in carbon tetrachloride toxicity in rabbit liver was evaluated. Carbon tetrachloride (CCl4), ethanol extracts of Chromolaena odorata (ETECO), sylimarin (a known hepatoprotective agent) and water, were used to induce variations in the oxidant/antioxidant balance in the test and control animals. This was used as a model to study the delicate balance between the activities and/or the intracellular concentrations of ...

  1. Hepatoprotective effect of Matrine salvianolic acid B salt on Carbon Tetrachloride-Induced Hepatic Fibrosis

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    Gao Hong-Ying

    2012-05-01

    Full Text Available Abstract The aim of this study was to investigate the hepatoprotective effect of Matrine salvianolic acid B salt on carbon tetrachloride (CCl4-induced hepatic fibrosis in rats. Salvianolic acid B and Matrine has long been used to treat liver fibrosis. Matrine salvianolic acid B salt is a new compound containing Salvianolic acid B and Matrine. Hepatic fibrosis induced by CCl4 was studied in animal models using Wistar rats. Organ coefficient, serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, hexadecenoic acid (HA, laminin (LN, hydroxyproline (Hyp, and glutathione (GSH, malondialdehyde (MDA, superoxide dismutase (SOD in liver tissues were measured, respectively. Histopathological changes in the livers were studied by hematoxylin-eosin (H&E staining and Masson Trichrome (MT examination. The expression of transforming growth factor-β1 (TGF-β1 and α-smooth muscle actin (α-SMA was observed by immunohistochemical analysis. A significant reduction in serum levels of AST, ALT, HA, LN and Hyp was observed in the Matrine salvianolic acid B salt treated groups, suggesting that the salt had hepatoprotective effects. The depletion of GSH and SOD, as well as MDA accumulation in liver tissues was suppressed by Matrine salvianolic acid B salt too. The expression of TGF-β1 and α-SMA measured by immunohistology was significantly reduced by Matrine salvianolic acid B salt in a dose-dependent manner. Matrine salvianolic acid B salt treatment attenuated the necro-inflammation and fibrogenesis induced by CCl4 injection, and thus it is promising as a therapeutic anti-fibrotic agent against hepatic fibrosis.

  2. Restrictive model of compensated carbon tetrachloride-induced cirrhosis in rats

    Institute of Scientific and Technical Information of China (English)

    Jean-Marc Regimbeau; David Fuks; Niaz Kohneh-Shahri; Benoit Terris; Olivier Soubrane

    2008-01-01

    AIM: To develop a simplified and quick protocol to induce cirrhosis and standardize models of partial liver resection in rats.METHODS: In Fischer F344 rats two modified protocols of phenobarbital-carbon tetrachloride (CCI4) (dilution 50%) gavage to induce cirrhosis (frequency adjusted according to weight, but each subsequent dose was systematically administered) were tested, i.e. the rapid and slow protocols. Prothrombin time (PT) and total bilirubin (TB) were also evaluated. Animals from the rapid group underwent 15% hepatectomy and animals from the slow group underwent 70% hepatectomy.RESULTS: Rapid protocol: This corresponded to 1 garage/4 d over 6 wk (mortality 30%). Mean PT was 35.2±2.8 s (normal: 14.5 s), and mean TB was 1.8±0.2mg/clL (normal: 0.1 mg/dL). Slow protocol: This corresponded to 1 gavage/6 d over 9 wk (mortality 10%).Mean PT was 11.8±0.2 s (normal: 14.5 s), and mean TB was 0.4 ± 0.04 mg/dL (normal: 0.1 mg/dL). Pathological analyses were performed in both protocols which showed persistent cirrhosis at 3 mo. Rat mortality in the rapid garage group who underwent 15% hepatectomy and in the slow garage group who underwent 70%hepatectomy was 50% and 70%, respectively.CONCLUSION: Our modified model is a simplified method to induce cirrhosis which is rapid (6 to 9 wk),efficient and stable up to 3 mo. Using this method, "Child Pugh A" or "Child Pugh BC" cirrhotic rats were obtained.Our models of cirrhosis and hepatectomy can be used in various situations focusing on postoperative survival.

  3. Erythropoietin decreases carbon tetrachloride-induced hepatic fibrosis by inhibiting transforming growth factor-beta

    Institute of Scientific and Technical Information of China (English)

    Soo Young Park; Joo Young Lee; Won Young Tak; Young Oh Kweon; Mi Suk Lee

    2012-01-01

    Background In addition to hematopoietic effect,the erythropoietin is known as a multifunctional cytokine with anti-fibrosis and organ-protective activities.The purpose of this study was to evaluate the effect of recombinant human erythropoietin (rhEPO) on hepatic fibrosis and hepatic stellate cells (HSCs).Methods Carbon tetrachloride (CCl4) induced hepatic fibrosis mice models were used for in vivo study and HSCs line for in vitro study.CCl4 and rhEPO (0,200 or 1000 U/kg) was injected intraperitoneally in BALB/c mice three times a week for 4 weeks.Immunohistochemistry and immunoblotting were performed to evaluate expressions of transforming growth factor-β31 (TGF-β1),α-smooth muscle actin (α-SMA),and fibronectin in explanted liver.Immunoblotting of α-SMA,phophorylated Smad-2 and Smad-2/3 was performed in HSCs treated with TGF-β1 and/or rhEPO.Results Expressions of TGF-β1,α-SMA,and fibronectin were increased in CCl4 injected mice livers,but significantly attenuated by co-treatment with CCl4 and rhEPO.Co-treatment of rhEPO markedly suppressed fibrosis in Masson's trichrome compared with treatment of only CCl4.TGF-β1 increased phosphorylated α-SMA,Smad-2 expressions in HSCs,which were decreased by rhEPO co-treatment.Conclusions Treatment of rhEPO effectively suppressed fibrosis in CCl4-induced liver fibrosis mice models.Anti-fibrosis effect of rhEPO could be related to inhibition of TGF-β1 induced activation of HSCs.

  4. Pharmacological investigation of Polyherbal formulation on Carbon tetrachloride (CCl4-induced liver damage in wistar rats

    Directory of Open Access Journals (Sweden)

    Hardik Soni

    2014-09-01

    Full Text Available Objective: To investigate effect of Polyherbal formulation on Carbon tetrachloride (CCl4-induced liver damage in wistar rats. Methods: Wistar albino rats weighing 180-230 g either sex were used. The selected animals were divided in to four groups where each group consisted of six animals. Experimentally liver damage was produced by intra-peritoneal administration of CCl4 and olive oil mixture (1:1 v/v (1 mL/kg, once daily, i.p. for 7 days. Test Drug, Polyherbal formulation was administered orally for 7 consecutive days at 3 mL/kg, once daily. On 8th day, Blood samples were collected to evaluate different serum biochemical parameters like Aspartate aminotransferase (AST, Alanine aminotransferase (ALT, Alkaline phosphatase (ALP, Total bilirubin and Total protein. Liver from animals of each group was dissected out for histopathological examination. Statistical analysis: Statistical calculation were done by analysis of variance (ANOVA followed by post hoc Dunnett’s test, with significant level of p<0.05. Results and dDiscussion: Polyherbal formulation showed significant effect on activity levels of serum AST, ALT, ALP and total bilirubin level while comparing test group to disease control group. It also showed significant elevation in decreased level of serum total protein. Pre-treatment of Polyherbal formulation restored the hepatic architecture and protected the liver tissue from fatty degenerative changes by preventing the toxic chemical reaction induced by CCl4. Conclusion: Finding of this study concludes that Polyherbal formulation (Vasuliv Syrup has promising hepatoprotective activity against CCl4-induced liver damage. It can be employed as safe and effective treatment for hepato-toxicity or liver damage.

  5. The effects of grape seed and colchicine on carbon tetrachloride induced hepatic damage in rats.

    Science.gov (United States)

    Atasever, Ayhan; Yaman, Duygu

    2014-10-01

    This study aims to determine the effects of grape seed and colchicine on carbon tetrachloride (CCl4) induced hepatic damage and on some serum biochemical parameters. Sixty male Wistar albino rats (200-250 g) were randomly divided into six groups (ten rats/group) and included the control group the group were given isotonic sodium chloride (1 mL/kg b.w) intraperitonealy (i.p.), group 2 the group treated i.p. injection of CCl4 (1.0 mL/kg b.w) in corn oil twice in the first week, Groups 3 and 4 injected with CCl4 as described for group 2 and the rats were orally given (100 mg/kg b.w) GSE and i.p. injected (10 μg/rat) with colchicine for four weeks, respectively and groups 5 and 6 were the grape seed and colchicine control groups in which rats were orally given grape seed (100 mg/kg b.w) and i.p. injected with colchicine (10 μg/rat), respectively. Anorexia, weight loss, motionlessness and hepatic colour variation at necropsy were observed in groups 2, 3, and 4. Hyperemia, focal bleeding, fat degeneration, changes ranging from degenerative to necrotic, increase in connective tissue elements, pronounced in portal sites in particular, and infiltration of lymphoid series cell observed in the livers of the rats in group 2, treated with CCl4. Histological hepatic changes in the rats in group 3 and 4 were similar to those in group 2. The levels of serum total protein, albumin and globulin decreased in groups 2, 3, and 4, compared with groups 1, 5 and 6; aspartate transaminase (ALT) activities increased. The lowest alkaline phosphatase (ALP) activities were in groups 4 and 5. We concluded that GSE and colchicine have not sufficient ameliorative effects to CCl4 induced acute hepatic damage.

  6. Amelioration of carbon tetrachloride-induced pulmonary toxicity with Oxalis corniculata.

    Science.gov (United States)

    Ahmad, Bushra; Khan, Muhammad Rashid; Shah, Naseer Ali

    2015-12-01

    This research work was planned to investigate the antioxidant potential of methanolic crude extract of Oxalis corniculata (OCME) against lung injuries initiated by carbon tetrachloride (CCl4) in rats at histological and biochemical level. A total of 42 female Sprague Dawley rats were randomly distributed in to seven groups and each group comprised of six rats. Experiment was completed in 22 days (10 doses at alternate days). Group I was not treated (control rats), while group II was administered with vehicles (olive oil and dimethyl sulfoxide), groups III, IV, and V were treated with 1 ml kg(-1) body weight (b.w.) of CCl4 (20% in olive oil). Group III received only CCl4, whereas groups IV and V were administered with 100 and 200 mg kg(-1) b.w. of OCME, respectively. Group VI was administered with OCME (200 mg kg(-1) b.w.) alone. Group VII was treated with sylimarin (50 mg kg(-1) b.w.). CCl4 enhanced the lipid peroxidation while reduced the glutathione in lung samples. Activities of antioxidant enzymes, catalase, peroxidase, superoxide dismutase, and glutathione-S-transferase decreased in lung homogenates with CCl4. Treatment of CCl4 induced deleterious changes in the microanatomy of lungs by rupturing the alveolar septa, thickening of alveolar walls, and damaging the cells with subsequent collapse of blood vessels due to the accumulation of degenerated blood cells. OCME, dose dependently, prevented the alterations in these parameters. These results suggest that OCME protected the lungs due to its intrinsic properties by scavenging of free radicals generated by CCl4. PMID:23796759

  7. Effect of WeiJia on carbon tetrachloride induced chronic liver injury

    Institute of Scientific and Technical Information of China (English)

    Pik-Yuen Cheung; Jay Chun; Hsiang-Fu Kung; Meng-su Yang; Qi Zhang; Ya-Ou Zhang; Gan-Rong Bai; Marie Chia-Mi Lin; Bernard Chan; Chi-Chun Fong; Lin Shi; Yue-Feng Shi

    2006-01-01

    AIM: To study the effect of WeiJia on chronic liver injury using carbon tetrachloride (CCl4) induced liver injury animal model.METHODS: Wistar rats weighing 180-220g were randomly divided into three groups: normal control group (Group A), CCl4 induced liver injury control group (Group B) and CCl4 induction with WeiJia treatment group (Group C). Each group consisted of 14 rats. Liver damage and fibrosis was induced by subcutaneous injection with 40% CCl4 in olive oil at 3 mL/kg body weight twice a week for eight weeks for Groups B and C rats whereas olive oil was used for Group A rats. Starting from the third week,Group C rats also received daily intraperitoneal injection of WeiJia at a dose of 1.25 μg/kg body weight. Animals were sacrificed at the fifth week (4 male, 3 female), and eighth week (4 male, 3 female) respectively. Degree of fibrosis were measured and serological markers for liver fibrosis and function including hyaluronic acid (HA), type Ⅳ collagen (CIV), γ-glutamyl transferase (γ-GT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. Alpha smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA) immunohistochemistry were also performed.RESULTS: CCl4 induction led to the damage of liver and development of fibrosis in Group B and Group C rats when compared to Group A rats. The treatment of WeiJia in Group C rats could reduce the fibrosis condition significantly compared to Group B rats. The effect could be observed after three weeks of treatment and was more obvious after eight weeks of treatment. Serum HA, CIV,ALT, AST and Y-GT levels after eight weeks of treatment for Group C rats were 58±22 μg/L (P0.05) respectively, similar to normal control group (Group A), but significantly different from CCl4 induced liver injury control group (Group B). An increase in PCNA and decrease in a-SMA expression level was also observed.CONCLUSION: WeiJia could improve liver function and reduce liver fibrosis

  8. Ameliorative effect of Ganoderma lucidum on carbon tetrachloride-induced liver fibrosis in rats

    Institute of Scientific and Technical Information of China (English)

    Wen-Chuan Lin; Wei-Lii Lin

    2006-01-01

    AIM: To investigate the effects of Reishi mushroom,Ganoderma lucidum extract (GLE), on liver fibrosis induced by carbon tetrachloride (CCl4) in rats.METHODS: Rat hepatic fibrosis was induced by CCl4.Forty Wistar rats were divided randomly into 4 groups:control, CCl4, and two GLE groups. Except for rats in control group, all rats were administered orally with CCl4(20%, 0.2 mL/100 g body weight) twice a week for 8weeks. Rats in GLE groups were treated daily with GLE (1 600 or 600 mg/kg) via gastrogavage throughout the whole experimental period. Liver function parameters,such as ALT, AST, albumin, and albumin/globulin (A/G)ratio, spleen weight and hepatic amounts of protein,malondiladehyde (MDA) and hydroxyproline (HP) were determined. Histochemical staining of Sirius red was performed. Expression of transforming growth factor β1(TGF-β1), methionine adenosyltransferase (MAT1) 1A and MAT2A mRNA were detected by using RT-PCR.RESULTS: CCl4 caused liver fibrosis, featuring increase in plasma transaminases, hepatic MDA and HP contents,and spleen weight; and decrease in plasma albumin,A/G ratio and hepatic protein level. Compared with CCl4group, GLE (600, 1 600 mg/kg) treatment significantly increased plasma albumin level and A/G ratio (P< 0.05)and reduced the hepatic HP content (P<0.01). GLE (1600 mg/kg) treatment markedly decreased the activities of transaminases (P< 0.05), spleen weight (P< 0.05) and hepatic MDA content (P<0.05); but increased hepatic protein level (P<0.05). Liver histology in the GLE (1600 mg/kg)-treated rats was also improved (P<0.01).RT-PCR analysis showed that GLE treatment decreased the expression of TGF-β1 (P< 0.05-0.001) and changed the expression of MAT1A (P<0.05-0.01) and MAT2A (P< 0.05-0.001).CONCLUSION: Oral administration of GLE significantly reduces CCl4-induced hepatic fibrosis in rats, probably by exerting a protective effect against hepatocellular necrosis by its free-radical scavenging ability.

  9. Melatonin ameliorates experimental hepatic fibrosis induced by carbon tetrachloride in rats

    Institute of Scientific and Technical Information of China (English)

    Ru-Tao Hong; Jian-Ming Xu; Qiao Mei

    2009-01-01

    AIM:To investigate the protective effects of melatonin on carbon tetrachloride (CCl4)-induced hepatic fibrosis in experimental rats. METHODS:All rats were randomly divided into normal control group, model control group treated with CCl4 for 12 wk, CCl4 + NAC group treated with CCl4 + NAC (100 mg/kg, i.p.) for 12 wk, CCl4 + MEL-1 group treated with CCl4 + melatonin (2.5 mg/kg) for 12 wk, CCl4 + MEL-2 group treated with CCl4 + melatonin (5.0 mg/kg) for 12 wk, and CCl4 + MEL-3 group treated with CCl4 + melatonin (10 mg/kg). Rats in the treatment groups were injected subcutaneously with sterile CCl4 (3 mL/kg, body weight) in a ratio of 2:3 with olive oil twice a week. Rats in normal control group received hypodermic injection of olive oil at the same dose and frequency as those in treatment groups. At the end of experiment, rats in each group were anesthetized and sacrificed. Hematoxylin and eosin (HE) staining and Van Gieson staining were used to examine changes in liver pathology. Serum activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and protein concentration were measured with routine laboratory methods using an autoanalyzer. Hydroxyproline (HYP) content in liver and malondialdehyde (MDA) and glutathione peroxidase (GPx) levels in liver homogenates were assayed by spectrophotometry. Serum hyaluronic acid (HA), laminin (LN), and procollagen Ⅲ N-terminal peptide (PⅢNP) were determined by radioimmunoassay. RESULTS:Pathologic grading showed that the fibrogenesis was much less severe in CCl4 + MEL3 group than in model control group ( u = 2.172, P < 0.05), indicating that melatonin (10 mg/kg) can significantly ameliorate CCl4-induced hepatic fibrotic changes. The serum levels of ALT and AST were markedly lower in CCl4 + MEL treatment groups (5, 10 mg/kg) than in model control group (ALT:286.23 serum laminin (LN) and hyaluronic acid (HA) levels and hydroxyproline (HYP) contents in liver were significantly lower in CCl4 + MEL-3 group (10

  10. Hepato protective effect of Spirulina Against Gamma Radiation and Carbon Tetrachloride induced Liver Injury in Rats

    International Nuclear Information System (INIS)

    The vast biodiversity of nature provides bioactive compounds that may be useful in the fight against chronic diseases. Although there are a number of drugs available in the market, long time use may cause a number of side effects. Spirulina is a microscopic and filamentous cyanobacterium that contains essential amino acids, essential fatty acids, vitamins, minerals and anti-oxidative components. In the present study, Spirulina platensis has been investigated as a possible modifier of radiation and carbon tetrachloride (CCl4) induced hepatic damage in albino rats. In the experiment, a total of 60 rats were used and divided into six groups of ten rats each: group 1, normal untreated rats; group 2, animals received only Spirulina (10 mg/kg) for 30 consecutive days; group 3, animals were exposed to 4 Gy whole body gamma radiation as a single shot dose; group 4, animals were injected intraperitoneally with CCl4 in olive oil (5 ml/kg i.p.) twice a week for four weeks ; group 5, rats were given orally Spirulina (10 mg/kg) for 30 days then exposed to 4 Gy gamma radiation as a single shot dose; and group 6, rats were given orally Spirulina (10 mg/kg) for 30 days and injected intraperitoneally with CCl4 in olive oil (5 ml/kg i.p.) twice a week for four weeks. The results revealed that animals treated with CCl4 or exposed to gamma radiation showed significant increase in the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β). Also, a marked increase in the liver tissue thiobarbituric acid reactive substances (TBARS) was observed. On the other hand, decrease in glutathione (GSH), glutathione transferase (GST), superoxide dismutase (SOD) and catalase (CAT) was observed in liver tissues of animal treated with CCl4 or exposed to gamma radiation. Oral pretreatment of rats with aqueous extract of Spirulina counteracted the radiation or CCl4 -induced lipid

  11. Cystamine ameliorates liver fibrosis induced by carbon tetrachloride via inhibition of tissue transglutaminase

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the anti-fibrosis effect of the tissue transglutaminase (tTG) specific inhibitor cystamine on liver fibrosis.METHODS: Sixty-eight male Sprague Dawley rats were divided into three groups: normal control, liver fibrosis control and cystamine-treated group. Liver fibrosis was induced by intraperitoneal injection of carbon tetrachloride (CCl4), and Cystamine was administrated by intraperitoneal injection starting 2 d before the first administration of CCl4. Animals in each group were further divided into 2 subgroups according to two time points of 4 wk and 8 wk after treatment. Hepatic function, pathological evaluation (semi-quantitative scoring system, SSS) and liver hydroxyproline (Hyp)content were examined. Real-time PCR was used to detect the expression of tTG, smooth muscle alpha actin (α-SMA), tissue inhibitor of metalloproteinase 1 (TIMP-1)and collagen-1 mRNA. The expressions of tTG and α-SMA protein were detected by Western Blotting.RESULTS: Eight weeks after treatment, the SSS score of liver was significantly less in the cystamine group than that in the fibrosis control group (P < 0.01). The levels of alanine aminotransferase (ALT) and total bile acid (TBA)at the 4 wk and 8 wk time points were decreased in the cystamine group compared with those in fibrosis controls (P < 0.01). Liver hydroxyproline content at the 4 wk and 8 wk time points showed a substantial reduction in the cystamine group compared to fibrosis controls (P < 0.01).The expression of tTG, α-SMA, collagen-1, TIMP-1 mRNA and tTG, as well as α-SMA protein was downregulated in the cystamine group compared to fibrosis controls.CONCLUSION: Cystamine can ameliorate CCl4 induced liver fibrosis and protect hepatic function. The possible mechanism is related to the reduced synthesis of the extracellular matrix (ECM) caused by the inhibition of hepatic stellate cell activation and decreased expression of TIMP-1.

  12. ANTIHEPATOTOXIC EFFECT OF MARRUBIUM VULGARE AND WITHANIA SOMNIFERA EXTRACTS ON CARBON TETRACHLORIDE-INDUCED HEPATOTOXICITY IN RATS

    OpenAIRE

    Elberry, Ahmed A; Fathalla M. Harraz; Salah A. Ghareib; Nagy, Ayman A.; Salah A. Gabr; Suliaman, Mansour I.; Abdel-Sattar, Essam

    2010-01-01

    Marrubium vulgare and Withania somnifera are used in folk medicine of several countries. Many researches showed that they are used for the treatment of variety of diseases due to their antioxidant effects. The present aim of this study was to evaluate the antihepatotoxic and antioxidant activities of the both extracts against carbon tetrachloride (CCl4)-induced hepatic damage in rats. Both extracts were given orally in a dose of 500 mg/kg/day for 4 weeks along with CCl4 started at the 7th wee...

  13. Inhibitory Effects of Pre and Post Radon Inhalation on Carbon Tetrachloride-induced Oxidative Damage in Mouse Organs

    OpenAIRE

    Nishiyama, Yuichi; Kataoka, Takahiro; Teraoka, Junichi; Sakoda, Akihiro; Ishimori, Yuu; Yamaoka, Kiyonori

    2012-01-01

    Radon inhalation activates antioxidative functions in some organs of mice. We examined the prevention effects of pre radon inhalation and the alleviation effects of post radon inhalation on carbon tetrachloride (CCl4)-induced oxidative damage in the brain, heart, lung, liver, and kidney of mice. In addition, we compared the effect of pre and post radon inhalation on oxidative damage. Mice inhaled radon at a concentration of 18000Bq/m3 for 6hrs before or after CCl4 administration. As a result,...

  14. Suppressive Effect of Kampo Formula "Juzen-taiho-to" on Carbon Tetrachloride-Induced Hepatotoxicity in Mice.

    Science.gov (United States)

    Yoshioka, Hiroki; Fukaya, Shiori; Miura, Nobuhiko; Onosaka, Satomi; Nonogaki, Tsunemasa; Nagatsu, Akito

    2016-01-01

    The aim of the present study was to investigate whether pretreatment with the Japanese herbal medicine, "Juzen-taiho-to" (JTX), had an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.e., alanine aminotransferase and aspartate aminotransferase), lipid peroxidation, and hepatic Ca(2+) levels. Pretreatment with JTX recovered the CCl4-induced anorexia. In addition, JTX pretreatment decreased CCl4-induced plasma levels of hepatic injury markers. Increased Ca(2+) is a known indicator of the final progression to hepatocyte death, and CCl4-induced hepatotoxicity is mainly caused by oxidative stress. The present study indicated CCl4-induced lipid peroxidation and hepatic Ca(2+) content decreased with JTX pretreatment. Our results suggest that JTX has potential to protect of CCl4-induced anorexia, and the modulation of oxidative stress. PMID:27582337

  15. 3-Alkynyl selenophene protects against carbon-tetrachloride-induced and 2-nitropropane-induced hepatic damage in rats.

    Science.gov (United States)

    Wilhelm, Ethel Antunes; Jesse, Cristiano Ricardo; Prigol, Marina; Alves, Diego; Schumacher, Ricardo Frederico; Nogueira, Cristina Wayne

    2010-12-01

    The aim of this study was to investigate the protective effect of 3-alkynyl selenophene (3-ASP) on acute liver injury induced by carbon tetrachloride (CCl(4)) and 2-nitropropane (2-NP) in rats. On the first day of treatment, the animals received 3-ASP (25 mg/kg, p.o.). On the second day, the rats received CCl(4) (1 mg/kg, i.p.) or 2-NP (100 mg/kg, p.o.). Twenty-four hours after CCl(4) or 2-NP administration, the animals were euthanized, and their plasma and liver were removed for biochemical and histological analyses. The histological analysis revealed extensive injury in the liver of CCl(4)-exposed and 2-NP-exposed rats, which was attenuated by 3-ASP. 3-ASP significantly attenuated (1) the increase in plasmatic aspartate and alanine aminotransferase activities and lipid peroxidation levels induced by CCl(4) and 2-NP; (2) the inhibition of δ-aminolevulinic dehydratase activity caused by 2-NP; and (3) the decrease in ascorbic acid (AA) levels and catalase (CAT) activity caused by CCl(4). AA levels and CAT activity remained unaltered in the liver of rats exposed to 2-NP. The protective effect of 3-ASP on acute liver injury induced by CCl(4) and 2-NP in rats was demonstrated. PMID:20397041

  16. Effect of Apitherapy Formulations against Carbon Tetrachloride-Induced Toxicity in Wistar Rats after Three Weeks of Treatment

    Directory of Open Access Journals (Sweden)

    Calin Vasile Andritoiu

    2014-08-01

    Full Text Available The human body is exposed nowadays to increasing attacks by toxic compounds in polluted air, industrially processed foods, alcohol and drug consumption that increase liver toxicity, leading to more and more severe cases of hepatic disorders. The present paper aims to evaluate the influence of the apitherapy diet in Wistar rats with carbon tetrachloride-induced hepatotoxicity, by analyzing the biochemical determinations (enzymatic, lipid and protein profiles, coagulation parameters, minerals, blood count parameters, bilirubin levels and histopathological changes at the level of liver, spleen and pancreas. The experiment was carried out on six groups of male Wistar rats. Hepatic lesions were induced by intraperitoneal injection of carbon tetrachloride (dissolved in paraffin oil, 10% solution. Two mL per 100 g were administered, every 2 days, for 2 weeks. Hepatoprotection was achieved with two apitherapy diet formulations containing honey, pollen, propolis, Apilarnil, with/without royal jelly. Biochemical results reveal that the two apitherapy diet formulations have a positive effect on improving the enzymatic, lipid, and protein profiles, coagulation, mineral and blood count parameters and bilirubin levels. The histopathological results demonstrate the benefits of the two apitherapy diet formulations on reducing toxicity at the level of liver, spleen and pancreas in laboratory animals.

  17. Evaluation of silymarin and / or ginger effect on induced hepatotoxicity by carbon tetrachloride in male albino rats

    Directory of Open Access Journals (Sweden)

    Hassan H. A.* and EL-Gendy A. M

    2003-09-01

    Full Text Available Liver disease appears to be increase. Part of this increase may be due to our frequent contact with chemicals and other environmental pollutants. The amount of medicne consumed has increased greatly which could be danger to the liver. The hepatoprotective flavonoid, silymarin (7.56 mg/Kg b. wt. and ginger (Zingiber officinale (1% of diet for 4 weeks were used to ameliorate the liver injury in rats intoxicated with carbon tetrachloride (CCL4 , single acute dose 4 ml/ Kg b. wt. of 50% v/v CCL4 in olive oil, subcutaneous. The obtained results showed that CCL4 decreased serum and liver total protein and albumin. Also reduced glutathione content. The antioxidant enzymes; glutathione-S-transferase, superoxide dismutase and catalase activity decreased in the liver of CCL4 toxicity group. On the other hand, CCL4 toxicity increased serum and liver bilirubin, total lipid and total cholestertol levels. In addition, liver function (aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase and liver lipid peroxidation content showed significant increase in the CCL4 treated group. Previous parameters turned back to normal values in carbon tetrachloride intoxicated rats after treating with silymarin and/ or ginger for one month. Meanwhile, the most interesting effect was induced by a combination of silymarin and ginger. Hence, the present findings will provide a potential scope for future use of ginger for the treatment of liver disorders.

  18. Amelioration of carbon tetrachloride-induced hepatotoxicity and haemotoxicity by aqueous leaf extract of Cnidoscolus aconitifolius in rats.

    Science.gov (United States)

    Saba, A B; Oyagbemi, A A; Azeez, O I

    2010-01-01

    This study was conducted to explore possible protective effect ofCnidoscolus aconitifolius (CA) leaf extract on carbon tetrachloride (CCl4)-induced hepatotoxicity and haemotoxicity in experimental animal models. Thirty six rats of six per group were used in this study. Group I received 10ml/kg normal saline as control. Group II-VI rats were administered with 1.25ml/kg body weight (bwt) of carbon tetrachloride intraperitonealy. Animals in groups III, IV, V and VI were however pre-treated with aqueous extract of Cnidoscolus aconitifolius at 100, 250, 500 and 750mg/kg body weight (bwt) respectively. Administration of CCL4 in untreated rats led to microcytic hypochromic anaemia, thrombocytopenia, increased erythrocyte fragility and stress induced leucocytosis accompanied with significant increase in neutrophils and decrease in lymphocyte counts. CCl4 also led to significant increase in serum transaminases (ALT and AST) and phosphatase (ALP) respectively compared with control animals. Also, CCL4 produced significant increase in serum blood urea nitrogen (BUN) and creatinine compared with normal rats. Pre-treatment with Cnidoscolus aconitifolius leaf extract brought about significant restoration of the haematological parameters to values that were comparable to those of the control with concomitant decrease in the activities of the marker of hepatic damage enzymes (ALT, AST and ALP), in a dose-dependent manner. Similarly, serum levels of blood urea nitrogen (BUN) and creatinine were also brought to near normal by the CA in a dose-dependent manner. From this study, we conclude that pre-exposure to Cnidoscolus aconitifolius leaf extract considerably reduced the effect of CCl4 on the blood parameters and ameliorated hepatic damage by the haloalkane. PMID:22314953

  19. Hepatoprotective and antioxidant activity ofBombax ceiba lfowers against carbon tetrachloride-induced hepatotoxicity in rats

    Institute of Scientific and Technical Information of China (English)

    Manish M Wanjari; Rachna Gangoria; Yadu Nandan Dey; Sudesh N Gaidhani; Narendra K Pandey; Ankush D Jadhav

    2016-01-01

    Aim: The lfowers ofBombax ceibaare traditionaly used as home remedy in the treatment of jaundice and spleen enlargement. The present work investigated the effect of aqueous extract of lfowers ofBombax ceiba (BCAE) on experimentaly induced hepatotoxicity in rats to substantiate its traditional use as hepatoprotective agent.Methods: Hepatotoxicity was induced in rats by carbon tetrachloride (CCl4) treatment; at the same time vehicle or BCAE (250 or 500 mg/kg) or silymarin (25 mg/kg) were administered daily oraly for seven days. Hepatotoxicity was assessed by estimating the activities of marker enzymes and by histological studies. The antioxidant effect of BCAE was assessed by measuring amount of antioxidant phytochemicals (total phenolics and lfavonoids), and DPPH free radical scavenging assay of the extract.Results: BCAE treatment signiifcantly prevented the CCl4-induced elevations in levels of glutamate oxaloacatate transaminase, glutamic pyruvic transaminase, alkaline phosphatase, bilirubin, and triglycerides, and decreased the total protein levels. Treatment with BCAE attenuated the CCl4-induced cytotoxic damage to liver. BCAE exhibited presence of antioxidant phytochemicals and showed scavanging action on DPPH radicals. The hepatoprotective effect of BCAE was comparable to that of the standard antioxidant hepatoprotective agent, silymarin. These ifndings indicated that BCAE showed hepatoprotective effect against CCl4-induced hepatotoxicity and exhibitedin vitro antioxidant effects.Conclusion:Bombax ceiba lfowers exhibited hepatoprotective effect which may be attributed to antioxidant potential. This study also validated their traditional medicinal use in liver disorders.

  20. In vitro and in vivo protective effects of proteoglycan isolated from mycelia of Ganoderma lucidum on carbon tetrachloride-induced liver injury

    Institute of Scientific and Technical Information of China (English)

    Xiao-Jun Yang; Jing Liu; Lin-Bai Ye; Fan Yang; Li Ye; Jin-Rong Gao; Zheng-Hui Wu

    2006-01-01

    AIM: To investigate the possible mechanism of the protective effects of a bioactive fraction, Ganoderma lucidum proteoglycan (GLPG) isolated from Ganoderma lucidum mycelia, against carbon tetrachloride-induced liver injury.METHODS: A liver injury model was induced by carbon tetrachloride. Cytotoxicity was measured by MTT assay.The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined with an automatic multifunction-biochemical analyzer and the levels of superoxide dismutase (SOD) and TNF-α were determined following the instructions of SOD kit and TNF radioimmunoassay kit. Liver sections were stained with hematoxylin and eosin (H&E) for histological evaluation and examined under light microscope.RESULTS: We found that GLPG can alleviate the L-02liver cells injury induced by carbon tetrachloride (CCl4)through the measurements of ALT and AST activities and the administration of GLPG to L-02 cells did not display any toxicity. Furthermore, histological analysis of mice liver injury induced by CCl4 with or without GLPG pretreatment indicated that GLPG can significantly suppress the toxicity induced by CCl4 in mice liver. We also found that GLPG reduced TNF-α level induced by CCl4 in the plasma of mice, whereas increased SOD activity in the rat serum.CONCLUSION: GLPG has hepatic protective activity against CCl4-induced injury both in vitro and in vivo. The possible anti-hepatotoxic mechanisms may be related to the suppression of TNF-α level and the free radical scavenging activity.

  1. Prevention of carbon tetrachloride (CCl4)-induced toxicity in testes of rats treated with Physalis peruviana L. fruit.

    Science.gov (United States)

    Abdel Moneim, Ahmed E

    2016-06-01

    Treatment of rats with carbon tetrachloride (CCl4; 2 ml/kg body weight) once a week for 12 weeks caused a significant decrease in serum levels of testosterone, luteinizing hormone, and follicle-stimulating hormone. These decreases in sex hormones were reduced with Physalis peruviana L. (Cape gooseberry) juice supplementation. In addition, testicular activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase suppressed with CCl4 were elevated after P. peruviana juice supplements. P. peruviana juice supplementation significantly increased the testicular glutathione and significantly decreased the level of lipid peroxidation and the nitric oxide production compared with the CCl4 group. In addition, the decline in the activity of antioxidant enzymes after CCl4 was ameliorated by P. peruviana Moreover, degeneration of germ and Leydig cells along with deformities in spermatogenesis induced after CCl4 injections were prevented with the supplementation of P. peruviana juice. Furthermore, P. peruviana juice attenuated CCl4-induced apoptosis in testes tissue by inhibition of caspase-3 activity. The results clearly demonstrate that P. peruviana juice augments the antioxidants defense mechanism against CCl4-induced reproductive toxicity and provides evidence that the juice may have a therapeutic role in free radical-mediated diseases and infertility. PMID:25147302

  2. Folic acid and melatonin ameliorate carbon tetrachloride-induced hepatic injury, oxidative stress and inflammation in rats

    Directory of Open Access Journals (Sweden)

    Ebaid Hossam

    2013-02-01

    Full Text Available Abstract This study investigated the protective effects of melatonin and folic acid against carbon tetrachloride (CCl4-induced hepatic injury in rats. Oxidative stress, liver function, liver histopathology and serum lipid levels were evaluated. The levels of protein kinase B (Akt1, interferon gamma (IFN-γ, programmed cell death-receptor (Fas and Tumor necrosis factor-alpha (TNF-α mRNA expression were analyzed. CCl4 significantly elevated the levels of lipid peroxidation (MDA, cholesterol, LDL, triglycerides, bilirubin and urea. In addition, CCl4 was found to significantly suppress the activity of both catalase and glutathione (GSH and decrease the levels of serum total protein and HDL-cholesterol. All of these parameters were restored to their normal levels by treatment with melatonin, folic acid or their combination. An improvement of the general hepatic architecture was observed in rats that were treated with the combination of melatonin and folic acid along with CCl4. Furthermore, the CCl4-induced upregulation of TNF-α and Fas mRNA expression was significantly restored by the three treatments. Melatonin, folic acid or their combination also restored the baseline levels of IFN-γ and Akt1 mRNA expression. The combination of melatonin and folic acid exhibited ability to reduce the markers of liver injury induced by CCl4 and restore the oxidative stability, the level of inflammatory cytokines, the lipid profile and the cell survival Akt1 signals.

  3. Hepatoprotective activity of Chhit-Chan-Than extract powder against carbon tetrachloride-induced liver injury in rats

    Directory of Open Access Journals (Sweden)

    Yi-Chun Lin

    2014-06-01

    Full Text Available The capability of Chhit-Chan-Than extract powder (CCTEP, 10% aqueous Ocimum gratissimum L. extract to protect against carbon tetrachloride (CCl4-induced oxidative stress and hepatotoxicity in vivo was investigated. Wistar rats were divided into five groups. Group A was a normal control group given only vehicle; Group B, the hepatotoxic group, was injected intraperitoneally twice a week with repeated 8% CCl4/olive oil (0.1 mL/100 g of body weight; Groups C–E, extract-treated groups received CCl4 and different doses of CCTEP (100 mg/kg and 200 mg/kg or silymarin (200 mg/kg of body weight daily by gavage for 8 weeks, respectively. The results showed that the CCl4-induced histopathogical changes may be prevented by CCTEP through reducing the intercellular collogen stack, dropping blood serum alanine aminotransferase and aspartate aminotransferase levels, and restoring the catalase activity and glutathione content. The hepatoprotective properties were further confirmed by the marked improvement in histopathological examination and by quantitative steatosis-fibrosis scoring. The above results suggest that CCTEP is able to prevent the liver inflammation and fibrosis induced by repeated CCl4 administration, and the hepatoprotective effects might be correlated partly with its antioxidant and free radical scavenging effects.

  4. COMPARATIVE EFFECT BETWEEN CHITOSAN AND CHITOSAN-Cu COMPLEX ON CARBON-TETRACHLORIDE (CCL4 INDUCED LIVER DAMAGE IN RATS

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    El-Habibi, E.M.; Sirag, H.M. and Edrees, G.M.

    2009-09-01

    Full Text Available BACKGROUND: Carbon tetrachloride (CCl4 is a toxic material known to induce lipid peroxidation and liver damage. The possible protective roles that involved by chitosan or chitosan-Cu complex against CCl4 induced liver intoxication were investigated in male rats. RESULTS: CCl4 administred at dose 20 mg/kg body weight i.p., exceed malondialdehyde (MDA and protein carbonyle (PC, depleted superoxide dismutase (SOD and glutathione (GSH, in concomitant with marked increase in investigated liver function parameters , alanine aminotransferase and aspartate aminotransferase (ALT, AST, impaired serum and liver total protein , albumin and globulin. An elevation in serum and hepatic total lipids, total cholesterol, triglycerides and serum LDL and VLDL levels as well as a low level of HDL were recorded. In the same time, there was a significant increase in sodium and iron contents in the serum while a significant decrease in potassium and zinc contents were recorded. Animals pretreated with chitosan (200 mg /kg body weight orally by stomach tube for 21 consecutive days prior to CCl4 challenge significantly attenuated most of the tested parameters, strengthen antioxidant defense system, ameliorated liver function effectively. Chitosan-Cu complex has a protective effect by a higher degree than that of chitosan only. CONCLUSION: These findings suggest that pretreatment with chitosan-Cu complex has higher hepato-protective effects than that of only chitosan against CCl4 induced toxicity in rat.

  5. ABHRAK BHASMA MEDIATED ALTERATIONS IN LIVER AND KIDNEY FUNCTIONS IN MALE ALBINO RATS DURING CARBON TETRACHLORIDE INDUCED TOXICITY

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    Teli Parashuram

    2013-10-01

    Full Text Available Abhrak bhasma, an Ayurvedic drug used against many diseases including hepatitis. In present study various doses of abhrak bhasma (10, 20, 30 and 40 mg/kg body wt were tested for hepatoprotective efficacy against carbon tetrachloride (CCl4 intoxicated liver and kidney functions in male albino rat. Administration of CCl4 to the normal rat increased serum levels of AST, ALT, ALP and bilirubin indicated acute damage. Abhrak bhasma treatment counteracted the action of CCl4 on liver and kidney functions. With the administration of increasing doses of abhrak bhasma all activities were dropped progressively and significantly at 40 mg dose as compared with silicate control. Conjugation metabolism and excretion of bilirubin were improved with increasing doses of abhrak bhasma suggesting dose dependent protection of all metabolic steps in bilirubin metabolism. Also CCl4 induced acute toxicity increased serum urea and creatinine content, which was progressively controlled by increasing abhrak bhasma doses. The findings of this study indicated that abhrak bhasma exert dose dependent protective effects in liver and kidneys functions against CCl4 induced toxicity in albino rat.

  6. Antihepatotoxic effect of marrubium vulgare and withania somnifera extracts on carbon tetrachloride-induced hepatotoxicity in rats.

    Science.gov (United States)

    Elberry, Ahmed A; Harraz, Fathalla M; Ghareib, Salah A; Nagy, Ayman A; Gabr, Salah A; Suliaman, Mansour I; Abdel-Sattar, Essam

    2010-09-01

    Marrubium vulgare and Withania somnifera are used in folk medicine of several countries. Many researches showed that they are used for the treatment of variety of diseases due to their antioxidant effects. The present aim of this study was to evaluate the antihepatotoxic and antioxidant activities of the both extracts against carbon tetrachloride (CCl4)-induced hepatic damage in rats. Both extracts were given orally in a dose of 500 mg/kg/day for 4 weeks along with CCl4 started at the 7th week of induction of hepatotoxicity. The antihepatotoxic activity was assessed by measuring aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), tissue content and malondialdehyde (MDA) as well as histopathological examination. Both extracts showed a significant antihepatotoxic effect by reducing significantly the levels of AST, ALT and LDH. However, ALP levels were decreased non-significantly. Regarding the antioxidant activity, they exhibited significant effects by increasing the GPx, GR and GST activities with increased GSH tissue contents and decreased production of MDA level. Furthermore, both extracts alleviated histopathological changes in rats' liver treated with CCl4. M. vulgare and W. somnifera protect the rats' liver against CCl4-induced hepatotoxicity. This effect may be attributed, at least in part, to the antioxidant activities of these extracts. PMID:24825994

  7. Antihepatotoxic effect of marrubium vulgare and withania somnifera extracts on carbon tetrachloride-induced hepatotoxicity in rats.

    Science.gov (United States)

    Elberry, Ahmed A; Harraz, Fathalla M; Ghareib, Salah A; Nagy, Ayman A; Gabr, Salah A; Suliaman, Mansour I; Abdel-Sattar, Essam

    2010-09-01

    Marrubium vulgare and Withania somnifera are used in folk medicine of several countries. Many researches showed that they are used for the treatment of variety of diseases due to their antioxidant effects. The present aim of this study was to evaluate the antihepatotoxic and antioxidant activities of the both extracts against carbon tetrachloride (CCl4)-induced hepatic damage in rats. Both extracts were given orally in a dose of 500 mg/kg/day for 4 weeks along with CCl4 started at the 7th week of induction of hepatotoxicity. The antihepatotoxic activity was assessed by measuring aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), reduced glutathione (GSH), tissue content and malondialdehyde (MDA) as well as histopathological examination. Both extracts showed a significant antihepatotoxic effect by reducing significantly the levels of AST, ALT and LDH. However, ALP levels were decreased non-significantly. Regarding the antioxidant activity, they exhibited significant effects by increasing the GPx, GR and GST activities with increased GSH tissue contents and decreased production of MDA level. Furthermore, both extracts alleviated histopathological changes in rats' liver treated with CCl4. M. vulgare and W. somnifera protect the rats' liver against CCl4-induced hepatotoxicity. This effect may be attributed, at least in part, to the antioxidant activities of these extracts.

  8. Compound list: carbon tetrachloride [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available carbon tetrachloride CCL4 00003 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/car...ates/LATEST/Rat/in_vitro/carbon_tetrachloride.Rat.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open...-tggates/LATEST/Rat/in_vivo/Liver/Single/carbon_tetrachloride.Rat.in_vivo.Liver.S...ingle.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/carbon_tetrachloride.Rat.in_vivo.Liver.Repeat.zip ...

  9. Synthesis of platelet-activating factor and its receptor expression in Kupffer cells in rat carbon tetrachloride-induced cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Yin-Ying Lu; Chun-Ping Wang; Lin Zhou; Yan Chen; Shu-Hui Su; Yong-Yi Feng; Yong-Ping Yang

    2008-01-01

    AIM:To determine the platelet-activating factor (PAF)synthesis and its receptor expression in Kupffer cells in rat carbon tetrachloride-induce dcirrhosis.METHODS:Kupffer cells,isolated from the livers of control and CCl4-induced cirrhotic rats,were placed in serum-free medium overnight.PAF saturation binding,ET-1 saturation and competition binding were assayed.ET-1 induced PAF synthesis,mRNA expression of PAF,preproendothelin-1,endothelin A (ETA) and endothelin B (ETB) receptors were also determined.RESULTS:A two-fold increase of PAF synthesis (1.42±0.14 vs 0.66±0.04 pg/μg DNA) and a 1.48-fold increase of membrane-bound PAF (1.02±0.06 vs 0.69±0.07 Pg/μg DNA) were observed in activated Kupffer cells of cirrhotic rats.The application of ET-1 to Kupffer cells induced PAF synthesis in a concentration-dependent manner in both cirrhotic and normal rats via ETB receptor,but PAF synthesis in the activated Kupffer cells was more effective than that in the normal Kupffer cells.In activated Kupffer cells,PAF receptor expression and PAF binding capacity were markedly enhanced.Activated Kupffer cells raised the [125I]-ET-1 binding capacity,but changed neither the affinity of the receptors,nor the expression of ETA receptor.CONCLUSION:Kupffer cells in the course of CCl4-induced cirrhosis are the main source of increased PAF.ET-1 is involved endogenously in stimulating the PAF synthesis in activated Kupffer cells via ETB receptor by paracrine.ETA receptor did not appear in activated Kupffer cells,which may exacerbate the hepatic and extrahepatic complications of cirrhosis.

  10. Protective Effects of Garlic Oil against Liver Damage Induced by Combined Administration of Ethanol and Carbon Tetrachloride in Rats

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    Ashraf B. Abdel-Naim a, Amani E. Khalifaa, Sherif H. Ahmed b

    2002-03-01

    Full Text Available Herbs are known to play a vital role in the management of various liver diseases. Garlic oil (GO contains numerous organosulfur compounds with potential hepatoprotective effects. The present work was planned to evaluate the possible preventive role of GO on biochemical and histopathological alterations induced by combined administration of ethanol (EOH and carbon tetrachloride (CCl4 in rat liver. Two dose levels of GO (5 or 10 mg/kg/day were administered orally to rats for 7 consecutive days with EOH + CCl4-induced liver damage. Activity of GO against liver damage was compared with that of silymarin (25 mg/kg/day, p.o. for 7 consecutive days. Biochemical parameters including serum aspartate aminotransferase (AST, alanine aminotransferase (ALT, gamma glutamyl transpeptidase (­GT, alkaline phophatase (ALP and bilirubin were estimated to assess the liver function. In addition, the level of total proteins, triglycerides, total cholesterol, glutathione (GSH, and thiobarbituric acid reactive substances (TBARS, in liver tissues were estimated. Liver damage was evidenced by an increase in the activity/level of AST, ALT, -GT, ALP and bilirubin in sera of rats after the combined administration of EOH and CCl4 compared to normal animals. Pretreatment of rats with GO reduced the EOH + CCl4-induced elevated levels of the above indices. Similarly, GO significantly prevented the decline in total proteins and the increase in triglycerides and total cholesterol resulted after EOH + CCl4 administration in rat liver homogenates. In addition, GO pretreatment restored liver GSH levels decreased due to EOH + CCl4 administration. The elevation in liver TBARS level due to EOH + CCl4 administration was also prevented by pretreatment with both low and high doses of GO. Histopathological examination indicated that GO exhibited an obvious preventive effect against the centrilobular necrosis and nodule formation induced by EOH + CCl4 administration. In conclusion, GO

  11. Protective effects of alisol B 23-acetate from edible botanical Rhizoma alismatis against carbon tetrachloride-induced hepatotoxicity in mice.

    Science.gov (United States)

    Meng, Qiang; Chen, Xinli; Wang, Changyuan; Liu, Qi; Sun, Huijun; Sun, Pengyuan; Huo, Xiaokui; Liu, Zhihao; Liu, Kexin

    2015-04-01

    Carbon tetrachloride (CCl4)-induced hepatotoxicity is a common syndrome with simultaneous severe hepatocyte death and acute cholestasis. The purpose of the present study is to investigate the hepatoprotective effect of alisol B 23-acetate (AB23A), a natural triterpenoid from edible botanical Rhizoma alismatis, on acute hepatotoxicity induced by CCl4 in mice, and further to elucidate the involvement of farnesoid X receptor (FXR), signal transducers and activators of transcription 3 (STAT3) in the hepatoprotective effect. H&E staining, BrdU immunohistochemistry and TUNEL assay were used to identify the amelioration of histopathological changes, hepatocyte proliferation and apoptosis. Real-time PCR and western blot assay were used to elucidate the mechanisms underlying AB23A hepatoprotection. The results indicated that AB23A treatment in a dose-dependent manner resulted in protection against hepatotoxicity induced by CCl4via FXR activation. Through FXR activation, AB23A promoted hepatocyte proliferation via an induction in hepatic levels of FoxM1b, Cyclin D1 and Cyclin B1. AB23A also reduced hepatic bile acids through a decrease in hepatic uptake transporter Ntcp, bile acid synthetic enzymes Cyp7a1, Cyp8b1, and an increase in efflux transporter Bsep, Mrp2 expression. In addition, AB23A induced the expression of STAT3 phosphorylation, and STAT3 target genes Bcl-xl and SOCS3, resulting in decreased hepatocyte apoptosis. In conclusion, AB23A produces a protective effect against CCl4-induced hepatotoxicity, due to FXR and STAT3-mediated gene regulation. PMID:25747392

  12. Modulation of gamma-irradiation and carbon tetrachloride induced oxidative stress in the brain of female rats by flaxseed oil.

    Science.gov (United States)

    Ismail, Amel F M; Salem, Asmaa A M; Eassawy, Mamdouh M T

    2016-08-01

    The activity of flaxseed oil (FSO) on gamma-irradiation (7Gy) and/or carbon tetrachloride (CCl4) induced acute neurotoxicity in rats' brain was investigated. The results revealed a significant decrease (poxide (NO), Tumor Necrosis Factor-alpha (TNF-α), Interleukin-1-beta (IL-1β), Interleukin-6 (IL-6), transforming growth factor-beta-1 (TGF-β1), iron (Fe), calcium (Ca), copper (Cu) and magnesium (Mg) levels were observed. Furthermore, the relative ratio of xanthine oxidase (XO) and inducible nitric-oxide synthase (iNOS) gene expression levels were elevated in the brain tissues of γ-irradiated and CCl4 intoxicated animals. Those effects were augmented due to the effect of CCl4-induced toxicity in γ-irradiated rats. The treatment of FSO displayed significant amendment of the studied parameters in the brain tissues of γ-irradiated and CCl4 intoxicated animals. FSO has a neuroprotective effect against CCl4-induced brain injury in gamma-irradiated rats. This effect is interrelated to the ability of FSO to scavenges the free radicals, enhances the antioxidant enzymes activity, increases GSH contents, down-regulates the inflammatory responses, ameliorates the iron, calcium, copper, magnesium, manganese levels and inhibiting the gene expression level of XO and iNOS in the brain tissues of intoxicated animals. In conclusion, this study demonstrated that the potent antioxidant and anti-inflammatory activities of FSO have the ability to improve the antioxidant status, suppress the inflammatory responses, and regulate the trace elements in the brain tissues of γ-irradiated, CCl4, and their combined effect in intoxicated animals. Consequently, FSO exhibited neuroprotective activity on γ-irradiated, CCl4, and their combined effect induced brain injury in rats. PMID:27232147

  13. Study of protective effect of Avicennia marina hydroethanolic leaf extract on testes tissue and spermatogenesis in male rat induced with carbon tetrachloride

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    Z soleimani

    2015-11-01

    Full Text Available Aim: The toxic chemical compounds are widelyused in the world. Carbon tetrachloride which is used in hygiene industries caused tissue disorders. Medicinal plants have protective effects in body tissues. In this study the protective effect of Avicennia marina leaf extract (MLE on spermatogenesis in male rat were induced with ccl4 investigating. Method and materials: The 42 male rats with 220-250 gr body weight were divided randomly in 6 groups(n=7: control (taking normal saline,0.5ml/day, i,p , sham(taking olive oil, 0.5ml/day, i,p single dose,group induced by ccl4(carbon tetrachloride 1:1 with olive oil,0.5ml single dose, i,p, treated groups: (1,2 and3 by carbon tetrachloride 1:1 with olive oil,0.5ml single dose and 200mg/Kg, 400mg/Kg and 800mg/kg MLE /day for 96 hrs, i,p. After the examination the blood samples were collected from heart directly and testosterone , FSH, LH , sperm count, sperm motility and GSI were analyzed and the microscopic studies of testes tissue were done. All data were expressed as mean±SEM. and statistical significance differences were accepted at P<0.05. Results: Our results showed that the carbon tetrachloride has necrotic effect in testes. The number of sperm and motility were increased and microscopic study of testes tissue showed the necrosis and inflammation with decrease in spermatogonia and spermatocytes comparedwith ccl4 induced only group significantly (P<0.001 and treated groups were no changed. Conclusion: the Avicennia marina hydroethanolic extract has antioxidant and flavonoids compounds which can protect the testes tissues from toxic chemical agents.

  14. A proteomic method for analysis of CYP450s protein expression changes in carbon tetrachloride induced male rat liver microsomes

    International Nuclear Information System (INIS)

    Carbon tetrachloride (CCl4) is a well-known model compound for producing chemical hepatic injury. Cytochrome P450 is an important monooxygenase in biology. We investigated the CYP450 protein expression in the in vivo hepatotoxicity of rats induced by CCl4. In this experiment, CCl4 were administered to male rats, and their livers at 24 h post-dosing were applied to the proteomic analysis. Blood biochemistry and histopathology were examined to identify specific changes. At the same time, a novel acetylation stable isotopic labeling method coupled with LTQ-FTICR mass spectrometry was applied to disclose the changes of cytochrome P450 expression amounts. The quantitative proteomics method demonstrated its correlation coefficient was 0.9998 in a 100-fold dynamic range and the average ratio of the labeled peptides was 1.04, which was very close to the theoretical ratio of 1.00 and the standard deviation (S.D.) of 0.21. With this approach, 17 cytochrome P450 proteins were identified and quantified with high confidence. Among them, the expression amount of 2C11, 3A2, and 2 E1 were down-regulated, while that of 2C6, 2B2, and 2B1 were up-regulated

  15. Investigation of Antioxidant and Hepatoprotective Activity of Standardized Curcuma xanthorrhiza Rhizome in Carbon Tetrachloride-Induced Hepatic Damaged Rats

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    Sutha Devaraj

    2014-01-01

    Full Text Available Curcuma xanthorrhiza (CX has been used for centuries in traditional system of medicine to treat several diseases such as hepatitis, liver complaints, and diabetes. It has been consumed as food supplement and “jamu” as a remedy for hepatitis. Hence, CX was further explored for its potential as a functional food for liver related diseases. As such, initiative was taken to evaluate the antioxidant and hepatoprotective potential of CX rhizome. Antioxidant activity of the standardized CX fractions was determined using in vitro assays. Hepatoprotective assay was conducted against carbon tetrachloride- (CCl4- induced hepatic damage in rats at doses of 125, 250, and 500 mg/kg of hexane fraction. Highest antioxidant activity was found in hexane fraction. In the case of hepatoprotective activity, CX hexane fraction showed significant improvement in terms of a biochemical liver function, antioxidative liver enzymes, and lipid peroxidation activity. Good recovery was observed in the treated hepatic tissues histologically. Hence, the results concluded that CX hexane fraction possessed prominent hepatoprotective activities which might be due to its in vitro antioxidant activity. These findings also support the use of CX as a functional food for hepatitis remedy in traditional medicinal system.

  16. Protective Effect of the Total Saponins from Rosa laevigata Michx Fruit against Carbon Tetrachloride-Induced Liver Fibrosis in Rats

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    Deshi Dong

    2015-06-01

    Full Text Available In this study, the protective effect of the total saponins from Rosa laevigata Michx (RLTS against liver fibrosis induced by carbon tetrachloride (CCl4 in rats was evaluated. The results showed that RLTS significantly rehabilitated the levels of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, glutathione, glutathione peroxidase, catalase, superoxide dismutase, hydroxyproline, α-smooth muscle actin, collagen I, collagen III and fibronectin, which were confirmed using H&E, Sirius Red and Masson histopathological assays. Further research indicated that RLTS markedly reduced cytochrome P450 2E1 activity, attenuated oxidative stress, and suppressed inflammation. In addition, RLTS facilitated matrix degradation through down-regulation of matrix metalloproteinase2, matrix metalloproteinase 9 and metalloproteinases1, and exerted the anti-fibrotic effects through affecting transforming growth factor β/Smad, focal adhesion kinase/phosphatidylinositol-3-kinase/amino kinase terminal/70-kDa ribosomal S6 Kinase (FAK-PI3K-Akt-p70S6K and mitogen-activated protein kinase (MAPK signaling pathways. Taken together, our data indicate that RLTS can be applied as one effective candidate for the treatment of liver fibrosis in the future.

  17. Duration-dependent hepatoprotective effects of propolis extract against carbon tetrachloride-induced acute liver damage in rats.

    Science.gov (United States)

    Bhadauria, Monika; Nirala, Satendra Kumar; Shukla, Sangeeta

    2007-01-01

    Propolis is a natural product produced by bees that was discovered through the study of traditional cures and knowledge of indigenous people throughout the world. It is rich in vitamins A, B, C, and E, and in amino acids, copper, iron, manganese, and zinc. The investigators studied the duration-dependent hepatoprotective effects of propolis extract (200 mg/kg, orally) against carbon tetrachloride (CCl 4; 1.5 mL/kg, intraperitoneally)-induced liver damage in rats. Administration of CCl 4 caused a sharp elevation in the activity of serum transaminases and serum alkaline phosphatase. A significant depletion in hepatically reduced glutathione was observed with significantly enhanced hepatic lipid peroxidation. After CCl 4 administration, glycogen contents and activities of alkaline phosphatase, adenosine triphosphatase, and succinic dehydrogenase were significantly decreased, whereas total protein contents and activity of acid phosphatase were increased in the liver and kidney. Propolis extract reversed alterations in all parameters when administered within 6, 12, and 24 h of toxicant exposure. Propolis therapy produced duration-dependent protection, with maximal protection achieved at 24 h after CCl 4 exposure. It is believed that propolis in its natural form has general pharmacologic value and marked hepatoprotective potential because of its composition of minerals, flavonoids, and phenolic compounds. PMID:18029340

  18. Curative Effect of Bone Marrow Cells Transplantation and/or Low Dose Gamma Irradiation on Liver Injuries Induced by Carbon Tetrachloride

    Directory of Open Access Journals (Sweden)

    * Mohamed E.M. Zowail, ** Hanaa F. M. Waer, ** Noaman A. Eltahawy, * Eman H. S.

    2012-01-01

    Full Text Available Liver is the most common target for toxic injury. Toxic agents include chemicals such as carbon tetrachloride (CCl4 and trichloroethylene. This study aimed to evaluate the effect of bone marrow cells (BMC transplantation and/or fractionated low doses (0.5 Gy gamma radiation on established liver fibrosis induced by CCl4. BMCs of male albino rats were transplanted into 4-weeks carbon tetrachloride (CCl4­treated and/or fractionated low doses (0.5 Gy gamma irradiated rats through the tail vein, and the rats were treated for 4 more weeks with CCl4 (total 8 weeks. Histological and ultrastructural investigations revealed that both bone marrow cells transplantation and low dose (0.5 Gy gamma radiation exposure with continuous CCl4 injection had reduced liver fibrosis as compared with rats treated with CCl4 alone.

  19. New therapeutic aspect for carvedilol: Antifibrotic effects of carvedilol in chronic carbon tetrachloride-induced liver damage

    Energy Technology Data Exchange (ETDEWEB)

    Hamdy, Nadia [Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt); El-Demerdash, Ebtehal, E-mail: ebtehal_dm@yahoo.com [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)

    2012-06-15

    Portal hypertension is a common complication of chronic liver diseases associated with liver fibrosis and cirrhosis. At present, beta-blockers such as carvedilol remain the medical treatment of choice for protection against variceal bleeding and other complications. Since carvedilol has powerful antioxidant properties we assessed the potential antifibrotic effects of carvedilol and the underlying mechanisms that may add further benefits for its clinical usefulness using a chronic model of carbon tetrachloride (CCl4)-induced hepatotoxicity. Two weeks after CCl4 induction of chronic hepatotoxicity, rats were co-treated with carvedilol (10 mg/kg, orally) daily for 6 weeks. It was found that treatment of animals with carvedilol significantly counteracted the changes in liver function and histopathological lesions induced by CCl4. Also, carvedilol significantly counteracted lipid peroxidation, GSH depletion, and reduction in antioxidant enzyme activities; glutathione-S-transferase and catalase that was induced by CCl4. In addition, carvedilol ameliorated the inflammation induced by CCl4 as indicated by reducing the serum level of acute phase protein marker; alpha-2-macroglobulin and the liver expression of nuclear factor-kappa B (NF-κB). Finally, carvedilol significantly reduced liver fibrosis markers including hydroxyproline, collagen accumulation, and the expression of the hepatic stellate cell (HSC) activation marker; alpha smooth muscle actin. In conclusion, the present study provides evidences for the promising antifibrotic effects of carvedilol that can be explained by amelioration of oxidative stress through mainly, replenishment of GSH, restoration of antioxidant enzyme activities and reduction of lipid peroxides as well as amelioration of inflammation and fibrosis by decreasing collagen accumulation, acute phase protein level, NF-κB expression and finally HSC activation. -- Highlights: ► Carvedilol is a beta blocker with antioxidant and antifibrotic

  20. Neutralization of ADAM8 ameliorates liver injury and accelerates liver repair in carbon tetrachloride-induced acute liver injury.

    Science.gov (United States)

    Li, San-Qiang; Zhu, Sha; Wan, Xue-Dong; Xu, Zheng-Shun; Ma, Zhao

    2014-04-01

    Although some studies have described the function of ADAM8 (a disintegrin and metalloprotease 8) related with rheumatoid arthritis, cancer and asthma, etc., the concrete role of ADAM8 in acute liver injury is still unknown. So mice respectively received anti-ADAM8 monoclonal antibody (mAb) of 100 μg/100 μl, 200 μg/100 μl or 300 μg/100 μl in PBS or PBS pre-injection. Then acute liver injury was induced in the mice by intraperitoneal (i.p.) injection of carbon tetrachloride (CCl₄). Serum AST and ALT level, Haematoxylin-eosin (H&E) staining, the expression level of vascular endothelial growth factor (VEGF), cytochrome P450 1A2 (CYP1A2) and proliferating cell nuclear antigen (PCNA) were detected in the mice after CCl4 administration. Our results showed that anti-ADAM8 mAb pre-injection could effectively lower AST and ALT levels (P < 0.05 or P < 0.01) and reduce liver injury (P < 0.05 or P <0.01), induce the expression of VEGF, CYP1A2 and PCNA (P <0.05 or P < 0.01) in dose-dependent manner compared with the control mice which received PBS pre-injection. In summary, our study suggested that ADAM8 might promote liver injury by inhibiting the proliferation of hepatocytes, angiogenesis and affecting the metabolism function of liver during acute liver injury induced by CCl₄. Anti-ADAM8 mAb injection might be suitable as a potential method for acute liver injury therapy. PMID:24646716

  1. Hepatoprotective effects of Arctium lappa Linne on liver injuries induced by chronic ethanol consumption and potentiated by carbon tetrachloride.

    Science.gov (United States)

    Lin, Song-Chow; Lin, Chia-Hsien; Lin, Chun-Ching; Lin, Yun-Ho; Chen, Chin-Fa; Chen, I-Cheng; Wang, Li-Ya

    2002-01-01

    Arctium lappa Linne (burdock) is a perennial herb which is popularly cultivated as a vegetable. In order to evaluate its hepatoprotective effects, a group of rats (n = 10) was fed a liquid ethanol diet (4 g of absolute ethanol/ 80 ml of liquid basal diet) for 28 days and another group (n = 10) received a single intraperitoneal injection of 0.5 ml/kg carbon tetrachloride (CCl(4)) in order to potentiate the liver damage on the 21st day (1 day before the beginning of A. lappa treatment). Control group rats were given a liquid basal diet which did not contain absolute ethanol. When 300 mg/kg A. lappa was administered orally 3 times per day in both the 1-day and 7-day treatment groups, some biochemical and histopathological parameters were significantly altered, both in the ethanol group and the groups receiving ethanol supplemented with CCl(4). A. lappa significantly improved various pathological and biochemical parameters which were worsened by ethanol plus CCl(4)-induced liver damage, such as the ethanol plus CCl(4)-induced decreases in total cytochrome P-450 content and NADPH-cytochrome c reductase activity, increases in serum triglyceride levels and lipid peroxidation (the deleterious peroxidative and toxic malondialdehyde metabolite may be produced in quantity) and elevation of serum transaminase levels. It could even restore the glutathione content and affect the histopathological lesions. These results tended to imply that the hepatotoxicity induced by ethanol and potentiated by CCl(4) could be alleviated with 1 and 7 days of A. lappa treatment. The hepatoprotective mechanism of A. lappa could be attributed, at least in part, to its antioxidative activity, which decreases the oxidative stress of hepatocytes, or to other unknown protective mechanism(s).

  2. Evaluating the effects of different fractions obtained from Gundelia tournefortii extract against carbon tetrachloride-induced liver injury in rats

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    Hossein Niknahad

    2016-03-01

    Full Text Available Xenobiotics-induced liver injury is a major challenge for clinicians and pharmaceutical industry. Hence, finding new therapeutic molecules against this complication has clinical value. The current investigation aimed to evaluate the potential protective effects of different fractions obtained from Gundelia tournefortii (GT hydroalcoholic extract in a rat model of acute hepatic injury. Male Sprague-Dawley rats (200 250 g were treated with carbon tetrachloride (CCl4 (1.5 ml/kg, i.p. Then ethanol, water, chloroform, ethyl acetate, and n-Butanol fractions of GT extract were administered. Biochemical and histopathological markers of hepatic injury were assessed, and glutathione (GSH and lipid peroxidation were monitored in liver samples. CCl4 administration caused hepatotoxicity as revealed by an increase in serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, and lactate dehydrogenase (LDH activity, as well as pathological changes of the liver. Furthermore, a significant reduction in hepatic glutathione content and an elevation in lipid peroxidation were observed in CCl4 treated rats. It was found that the n butanol (200 mg/kg and the ethyl acetate (300 mg/kg fractions of GT extract protected liver against CCL4 induced damage as judged by lower AST, ALT, LDH and lipid peroxidation, prevention of tissue glutathione depletion, and alleviation of histopathological damages of liver in the extract treated animals. As n butanol and the ethyl acetate fractions of GT effectively alleviated the liver injury induced by CCl4 and provided antioxidant properties, we might be able to propose that the hepatoprotective chemicals of GT extract are present in these fractions.

  3. Electroporative interleukin-10 gene transfer ameliorates carbon tetrachloride-induced murine liver fibrosis by MMP and TIMP modulation

    Institute of Scientific and Technical Information of China (English)

    Wen-ying CHOU; Cheng-nan LU; Tsung-hsing LEE; Chia-ling WU; Kung-sheng HUNG; Allan M CONCEJERO; Bruno JAWAN; Cheng-haung WANG

    2006-01-01

    Aim:Liver fibrosis represents a process of healing and scarring in response to chronic liver injury.Effective therapies for liver fibrosis are lacking.Interleukin-10 (IL-10) is a cytokine that downregulates pro-inflammatory responses and has a modulatory effect on hepatic fibrogenesis.The aim of this study was to investigate whether electroporative IL-10 gene therapy has an hepatic fibrolytic effect on mice.Methods:Hepatic fibrosis was induced by administering carbon tetrachloride (CCl4) for 10 weeks in mice.The human IL-10 expression plasmid was delivered via electroporation after hepatic fibrosis was established.Histopathology,reverse transcription polymerase chain reaction (RT-PCR) ,immunoblotting,and gelatin zymography were used to investigate the possible mechanisms of action of IL-10.Results:Human IL-10 gene therapy reversed CCl4-induced liver fibrosis in mice.RT-PCR revealed that IL-10 gene therapy attenuated liver TGF-β1,collagen αl,fibronectin,and cell adhesion molecule mRNA upregulation.Following gene transfer,both the activation of α-smooth muscle actin and cyclooxygenase-2 were significantly attenuated.Furthermore.IL-10 significantly inhibited matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of matrix metalloproteinase (TIMP) activation after CCl4 intoxication.Conclusions:We demonstrated that IL-10 gene therapy attenuated CCl4-induced liver fibrosis in mice.IL-10 prevented upregulated fibrogenic and pro-inflammatory gene responses.Its collagenolytic effect may be attributed to MMP and TIMP modulation.IL-10 gene therapy may be an effective therapeutic modality against liver fibrosis with potential clinical use.

  4. Rat liver mitochondrial damage under acute or chronic carbon tetrachloride-induced intoxication: Protection by melatonin and cranberry flavonoids

    International Nuclear Information System (INIS)

    In current societies, the risk of toxic liver damage has markedly increased. The aim of the present work was to carry out further research into the mechanism(s) of liver mitochondrial damage induced by acute (0.8 g/kg body weight, single injection) or chronic (1.6 g/ kg body weight, 30 days, biweekly injections) carbon tetrachlorideinduced intoxication and to evaluate the hepatoprotective potential of the antioxidant, melatonin, as well as succinate and cranberry flavonoids in rats. Acute intoxication resulted in considerable impairment of mitochondrial respiratory parameters in the liver. The activity of mitochondrial succinate dehydrogenase (complex II) decreased (by 25%, p 4 displayed obvious irreversible impairments. Long-term melatonin administration (10 mg/kg, 30 days, daily) to chronically intoxicated rats diminished the toxic effects of CCl4, reducing elevated plasma activities of alanine aminotransferase and aspartate aminotransferase and bilirubin concentration, prevented accumulation of membrane lipid peroxidation products in rat liver and resulted in apparent preservation of the mitochondrial ultrastructure. The treatment of the animals by the complex of melatonin (10 mg/kg) plus succinate (50 mg/kg) plus cranberry flavonoids (7 mg/kg) was even more effective in prevention of toxic liver injury and liver mitochondria damage. Highlights: ► After 30-day chronic CCl4 intoxication mitochondria displayed considerable changes. ► The functional parameters of mitochondria were similar to the control values. ► Melatonin + succinate + flavonoids prevented mitochondrial ultrastructure damage. ► The above complex enhanced regenerative processes in the liver.

  5. Restorative effect of (5E, 13E)-5,13-Docosadienoic acid on carbon tetrachloride induced oxidative stress in rats

    Institute of Scientific and Technical Information of China (English)

    Anand Thiru; Gokulakrishnan Kannan; Kalaiselvan Ashokan; Velavan Sivanandam

    2012-01-01

    Objective: To evaluate the restorative effect of (5E, 13E)-5,13-Docosadienoic acid on carbon tetrachloride induced oxidative stress in rats. Methods: Wistar strain male albino rats, weighing 180-200 g/bw were selected for the study. Rats were divided into four groups. Group I animals were served as normal control. Group II was administered with corn oil (3 ml/kg, i.p.) as vehicle control. Group III was given single dose (29th day) of CCl4 in corn oil (1:1 v/v, 3 ml/kg, i.p.). Groups IV was treated with (5E, 13E)-5,13-Docosadienoic acid (DA) (6 mg/kg body weight) for 28 days and given single dose of (29th day) CCl4 in corn oil (1:1 v/v, 3 ml/kg, i.p.). Six hours after CCl4 intoxication, the experimental animals were sacrificed. The blood samples were collected. Liver was excised immediately and immersed in physiological saline. Results: The lipid peroxidation was initiated in CCl4 intoxicated rats which is evidenced by thiobarbituric acid (TBARS) and diminution of GSH content in liver. Super oxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), vitamin C and E in CCl4 intoxicated rats retrieved towards near normalcy. After treating with DA which significantly altered (P<0.001) serum marker enzyme level and antioxidant level near normal against CCl4 treated rats. Conclusions: It was observed that the entire variable tested i.e., SOD, CAT, GPx, reduced glutathione, vitamin C and E recorded a significant decline on CCl4 treatment. However, treatment with DA restored the levels to near normal value, suggesting the therapeutic effect of DA to counter the oxidative stress.

  6. Inhibition of soluble epoxide hydrolase attenuates hepatic fibrosis and endoplasmic reticulum stress induced by carbon tetrachloride in mice

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Todd R. [Department of Entomology and Comprehensive Cancer Center, University of California, Davis, CA 95616 (United States); Bettaieb, Ahmed [Department of Nutrition, University of California, Davis, CA 95616 (United States); Kodani, Sean; Dong, Hua [Department of Entomology and Comprehensive Cancer Center, University of California, Davis, CA 95616 (United States); Myers, Richard; Chiamvimonvat, Nipavan [Department of Internal Medicine: Cardiovascular, University of California, Davis, CA 95616 (United States); Haj, Fawaz G. [Department of Nutrition, University of California, Davis, CA 95616 (United States); Department of Internal Medicine: Endocrinology, Diabetes and Metabolism, University of California, Davis, CA 95616 (United States); Hammock, Bruce D., E-mail: bdhammock@ucdavis.edu [Department of Entomology and Comprehensive Cancer Center, University of California, Davis, CA 95616 (United States)

    2015-07-15

    Liver fibrosis is a pathological condition in which chronic inflammation and changes to the extracellular matrix lead to alterations in hepatic tissue architecture and functional degradation of the liver. Inhibitors of the enzyme soluble epoxide hydrolase (sEH) reduce fibrosis in the heart, pancreas and kidney in several disease models. In this study, we assess the effect of sEH inhibition on the development of fibrosis in a carbon tetrachloride (CCl{sub 4})-induced mouse model by monitoring changes in the inflammatory response, matrix remolding and endoplasmic reticulum stress. The sEH inhibitor 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) was administered in drinking water. Collagen deposition in the liver was increased five-fold in the CCl{sub 4}-treated group, and this was returned to control levels by TPPU treatment. Hepatic expression of Col1a2 and 3a1 mRNA was increased over fifteen-fold in the CCl{sub 4}-treated group relative to the Control group, and this increase was reduced by 50% by TPPU treatment. Endoplasmic reticulum (ER) stress observed in the livers of CCl{sub 4}-treated animals was attenuated by TPPU treatment. In order to support the hypothesis that TPPU is acting to reduce the hepatic fibrosis and ER stress through its action as a sEH inhibitor we used a second sEH inhibitor, trans-4-(4-[3-(4-trifluoromethoxy-phenyl)-ureido]-cyclohexyloxy)-benzoic acid (t-TUCB), and sEH null mice. Taken together, these data indicate that the sEH may play an important role in the development of hepatic fibrosis induced by CCl{sub 4}, presumably by reducing endogenous fatty acid epoxide chemical mediators acting to reduce ER stress. - Highlights: • We administer an inhibitor of sEH in a CCl4 murine model. • sEH inhibition reduces liver collagen deposition and pro-fibrotic gene expression. • sEH inhibition induces MMP-1a activity.

  7. Attenuation of carbon tetrachloride-induced hepatic fibrosis by glycine, vitamin E and vitamin C

    Directory of Open Access Journals (Sweden)

    Aziza A. Saad

    2014-09-01

    Conclusion: The results of this study confirmed the ameliorative effects of vitamin E plus C combination and glycine supplements against liver fibrosis in rats induced by CCl4 [J Exp Integr Med 2014; 4(3.000: 180-186

  8. Role of nuclear receptor CAR in carbon tetrachloride-induced hepatotoxicity

    Institute of Scientific and Technical Information of China (English)

    Yuichi Yamazaki; Satoru Kakizaki; Norio Horiguchi; Hitoshi Takagi; Masatomo Mori; Masahiko Negishi

    2005-01-01

    AIM: To investigate the precise roles of CAR in CCl4-induced acute hepatotoxicity.METHODS: To prepare an acute liver injury model, CCl4 was intraperitoneally injected in CAR+/+ and CAR-/- mice.RESULTS: Elevation of serum alanine aminotransferase and extension of centrilobular necrosis were slightly inhibited in CAR-/- mice compared to CAR+/+ mice without PB. Administration of a CAR inducer, PB, revealed that CCl4-induced liver toxicity was partially inhibited in CAR-/- mice compared with CAR+/+ mice. On the other hand,androstanol, an inverse agonist ligand, inhibited hepatotoxicity in CAR+/+ but not in CAR-/- mice. Thus, CAR activation caused CCl4 hepatotoxicity while CAR inhibition resulted in partial protection against CCl4-induced hepatotoxicity.There were no differences in the expression of CYP2E1, the main metabolizing enzyme for CCl4, between CAR+/+ and CAR-/- mice. However, the expression of other CCl4-metabolizing enzymes, such as CYP2B10 and 3A11, was induced by PB in CAR+/+ but not in CAR-/- mice. Although the main pathway of CCl4-induced acute liver injury is mediated by CYP2E1, CAR modulates its pathway via induction of CYP2B10 and 3A11 in the presence of activator or inhibitor.CONCLUSION: The nuclear receptor CAR modulates CCl4-induced liver injury via induction of CCl4-metabolizing enzymes in the presence of an activator. Our results suggest that drugs interacting with nuclear receptors such as PB might play critical roles in drug-induced liver injury or drugdrug interaction even though such drugs themselves are not hepatotoxic.

  9. Carbon tetrachloride induced kidney and lung tissue damages and antioxidant activities of the aqueous rhizome extract of Podophyllum hexandrum

    Directory of Open Access Journals (Sweden)

    Zargar Bilal

    2011-02-01

    Full Text Available Abstract Background The present study was conducted to evaluate the in vitro and in vivo antioxidant properties of aqueous extract of Podophyllum hexandrum. The antioxidant potential of the plant extract under in vitro situations was evaluated by using two separate methods, inhibition of superoxide radical and hydrogen peroxide radical. Carbon tetrachloride (CCl4 is a well known toxicant and exposure to this chemical is known to induce oxidative stress and causes tissue damage by the formation of free radicals. Methods 36 albino rats were divided into six groups of 6 animals each, all animals were allowed food and water ad libitum. Group I (control was given olive oil, while the rest groups were injected intraperitoneally with a single dose of CCl4 (1 ml/kg as a 50% (v/v solution in olive oil. Group II received CCl4 only. Group III animals received vitamin E at a concentration of 50 mg/kg body weight and animals of groups IV, V and VI were given extract of Podophyllum hexandrum at concentration dose of 20, 30 and 50 mg/kg body weight. Antioxidant status in both kidney and lung tissues were estimated by determining the activities of antioxidative enzymes, glutathione reductase (GR, glutathione peroxidase (GPX, glutathione-S-transferase (GST and superoxide dismutase (SOD; as well as by determining the levels of reduced glutathione (GSH and thiobarbituric acid reactive substances (TBARS. In addition, superoxide and hydrogen peroxide radical scavenging activity of the extract was also determined. Results Results showed that the extract possessed strong superoxide and hydrogen peroxide radical scavenging activity comparable to that of known antioxidant butylated hydroxy toluene (BHT. Our results also showed that CCl4 caused a marked increase in TBARS levels whereas GSH, SOD, GR, GPX and GST levels were decreased in kidney and lung tissue homogenates of CCl4 treated rats. Aqueous extract of Podophyllum hexandrum successfully prevented the alterations

  10. Rat liver mitochondrial damage under acute or chronic carbon tetrachloride-induced intoxication: Protection by melatonin and cranberry flavonoids

    Energy Technology Data Exchange (ETDEWEB)

    Cheshchevik, V.T. [Institute for Pharmacology and Biochemistry, National Academy of Sciences of Belarus, Len. Kom. Blvd. - 50, 230017 Grodno (Belarus); Department of Biochemistry, Yanka Kupala Grodno State University, Len. Kom. Blvd. - 50, 230017 Grodno (Belarus); Lapshina, E.A.; Dremza, I.K.; Zabrodskaya, S.V. [Institute for Pharmacology and Biochemistry, National Academy of Sciences of Belarus, Len. Kom. Blvd. - 50, 230017 Grodno (Belarus); Reiter, R.J. [Department of Cellular and Structural Biology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229–3900 (United States); Prokopchik, N.I. [Grodno State Medical University, Gorkogo - 80, 230015 Grodno (Belarus); Zavodnik, I.B., E-mail: zavodnik_il@mail.ru [Institute for Pharmacology and Biochemistry, National Academy of Sciences of Belarus, Len. Kom. Blvd. - 50, 230017 Grodno (Belarus); Department of Biochemistry, Yanka Kupala Grodno State University, Len. Kom. Blvd. - 50, 230017 Grodno (Belarus)

    2012-06-15

    In current societies, the risk of toxic liver damage has markedly increased. The aim of the present work was to carry out further research into the mechanism(s) of liver mitochondrial damage induced by acute (0.8 g/kg body weight, single injection) or chronic (1.6 g/ kg body weight, 30 days, biweekly injections) carbon tetrachlorideinduced intoxication and to evaluate the hepatoprotective potential of the antioxidant, melatonin, as well as succinate and cranberry flavonoids in rats. Acute intoxication resulted in considerable impairment of mitochondrial respiratory parameters in the liver. The activity of mitochondrial succinate dehydrogenase (complex II) decreased (by 25%, p < 0.05). Short-term melatonin treatment (10 mg/kg, three times) of rats did not reduce the degree of toxic mitochondrial dysfunction but decreased the enhanced NO production. After 30-day chronic intoxication, no significant change in the respiratory activity of liver mitochondria was observed, despite marked changes in the redox-balance of mitochondria. The activities of the mitochondrial enzymes, succinate dehydrogenase and glutathione peroxidase, as well as that of cytoplasmic catalase in liver cells were inhibited significantly. Mitochondria isolated from the livers of the rats chronically treated with CCl{sub 4} displayed obvious irreversible impairments. Long-term melatonin administration (10 mg/kg, 30 days, daily) to chronically intoxicated rats diminished the toxic effects of CCl{sub 4}, reducing elevated plasma activities of alanine aminotransferase and aspartate aminotransferase and bilirubin concentration, prevented accumulation of membrane lipid peroxidation products in rat liver and resulted in apparent preservation of the mitochondrial ultrastructure. The treatment of the animals by the complex of melatonin (10 mg/kg) plus succinate (50 mg/kg) plus cranberry flavonoids (7 mg/kg) was even more effective in prevention of toxic liver injury and liver mitochondria damage

  11. Study of protective effect of Avicennia marina hydroethanolic leaf extract on testes tissue and spermatogenesis in male rat induced with carbon tetrachloride

    OpenAIRE

    Soleimani, Z.; N Mirazi

    2015-01-01

    Aim: The toxic chemical compounds are widelyused in the world. Carbon tetrachloride which is used in hygiene industries caused tissue disorders. Medicinal plants have protective effects in body tissues. In this study the protective effect of Avicennia marina leaf extract (MLE) on spermatogenesis in male rat were induced with ccl4 investigating. Method and materials: The 42 male rats with 220-250 gr body weight were divided randomly in 6 groups(n=7): control (taking normal saline,0.5ml/day, i,...

  12. Nicotinamide late protective effects against carbon tetrachloride-induced liver necrosis.

    Science.gov (United States)

    de Ferreyra, E C; Bernacchi, A S; San Martín, M F; Castro, G D; Castro, J A

    1994-06-01

    Nicotinamide (NIC) is known to increase the synthesis of pyridine nucleotides and also to inhibit the hydrolysis of them to ADP-ribose, which in turn is involved in Ca2+ release from mitochondria via the ADP ribosylation of crucial mitochondrial proteins. In this work, we test the potential ability of NIC to be a late protective agent against CCl4-induced liver necrosis. We observed that 1 g/kg po NIC, 30 min before or 6 or 10 hr after CCl4 (1 ml/kg), given ip as a 20% (v/v) solution in olive oil, was able to significantly prevent the necrogenic effect of the hepatotoxin at 24 hr as evidenced by determination of isocitric dehydrogenase activity in plasma or by histological observation. NIC administration 6 hr after CCl4 prevented fatty liver induced by hepatotoxin at 24 hr. NIC did not modify CCl4-induced lipid peroxidation process at 1 hr after CCl4 and decreased the covalent binding of 14CCl4 to lipids. NIC decreased the levels of 14CCl4 reaching the liver when given 30 min before hepatotoxin but not when given 6 hr after it. NIC lowered body temperature of rats at 1, 3, and 6 hr and augmented it at 24 hr after CCl4. NIC concentrations in liver as determined by GC/MS/SIM analysis were 21 micrograms/g liver 1 hr after administration and 53 micrograms/g at 3 hr. Late preventive effects of NIC against CCl4 induced liver necrosis when given at 6 or 10 hr after CCl4 are compatible with the hypothesis that NIC restores mitochondrial ability for Ca2+ uptake. This hypothesis remains to be proved and is being further challenged in our laboratory. PMID:7957779

  13. Hepatoprotective effects of fermented Curcuma longa L. on carbon tetrachloride-induced oxidative stress in rats.

    Science.gov (United States)

    Kim, Yongjae; You, Yanghee; Yoon, Ho-Geun; Lee, Yoo-Hyun; Kim, Kyungmi; Lee, Jeongmin; Kim, Min Soo; Kim, Jong-Choon; Jun, Woojin

    2014-05-15

    The hepatoprotective effect of fermented Curcuma longa L. (FC) was investigated in rats under CCl4-induced oxidative stress. FC at a dose of 30 or 300 mg/kg body weight (b.w.) was orally administered for 14 days followed by a single dose of CCl4 (1.25 mL/kg b.w. in 20% corn oil) on day 14. Pretreatment with FC drastically prevented the elevated activities of serum AST, ALT, LDH, and ALP caused by CCl4-induced hepatotoxicity. Histopathologically evident hepatic necrosis was significantly ameliorated by FC pretreatment. When compared to the CCl4-alone treated group, rats pretreated with FC displayed the reduced level of malondialdehyde. Furthermore, FC enhanced antioxidant capacities with higher activities of catalase, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase, and level of reduced glutathione. These results suggest that FC could be a candidate used for the prevention against various liver diseases induced by oxidative stress via elevating antioxidative potentials and decreasing lipid peroxidation.

  14. Hepatoprotective Activity of Cassia fistula root against Carbon tetrachloride-Induced Hepatic Injury in rats (Wistar

    Directory of Open Access Journals (Sweden)

    SAGAR DAWADA

    2012-04-01

    Full Text Available The protective effects of the alcoholic extract of Cassia fistula root; against CCl4 induced hepatic failure in male albino rats (wistar strain was investigated. For acute and massive invasion of hepatopathy, CCl4 (s.c injection of CCl4+Olive Oil in 1:1 ratio; 2ml/kg was used and the insidious intoxication was evidenced bysignificant turmoil of various biochemical parameters followed by significant (p<0.001 weight loss in toxic control group. The administration of alcoholic root extract (200mg/kg and 100mg/kg of body weight for 7 days, elicited protective action since the elevated levels of marker enzymes (SGOT, SGPT, ALP of liver functionswere found to be decreasing progressively in a dose dependent manner. The final body weight was also significantly (p<0.001 increased when compared with the toxic control group. The serum total protein and theserum albumin were also approaching normal values. The results found in alcoholic extract 200mg/kg treated rat were quite promising and were comparable with a standard drug Silymarin. In the alcoholic extract 200mg/kg treated rat group all the marker enzymes were analyzed to be decreasing significantly. The statistically processed results support the conclusion, that the alcoholic root extract of Cassia fistula root (200mg/kg and 100mg/kg possesses dose dependent, significant protective activity against CCl4 induced hepatotoxicity.

  15. Late protective effects of the anticalmodulin drug fluphenazine on carbon tetrachloride-induced liver necrosis.

    Science.gov (United States)

    de Ferreyra, E C; Bernacchi, A S; San Martin, M F; Castro, G D; Castro, J A

    1995-09-01

    Fluphenazine (FP) treatment (50 mg/kg bw, ip in saline) 30 min before or 6 or 10 h after CCl4 administration (1 ml/kg ip in olive oil) significantly prevented the liver necrosis produced by the hepatotoxin at 24 h. FP had enhancing effects on the covalent binding of CCl4 reactive metabolites to cellular constituents and on CCl4 induced lipid peroxidation. FP lowered body temperature of the CCl4-poisoned animals during the 24 h observation period. The obtained results are compatible but do not prove the hypothesis that calmodulin (CaM) had participation in late occurring events preceding necrosis. FP lowering action on body temperature, however, might also play a role in the effects of this drug on the onset of CCl4 induced liver necrosis. FP levels in liver tissue as determined by gas chromatography-mass spectrometry evidenced the presence of the drug in amounts sufficient to inhibit CaM and that suggests that not all preventive effects of FP are due to its indirect actions on the central nervous system via decreased body temperature. PMID:8561921

  16. Modulatory effect of Mangifera indica against carbon tetrachloride induced kidney damage in rats

    Directory of Open Access Journals (Sweden)

    Awodele Olufunsho

    2015-12-01

    Full Text Available There is little scientific evidence on the local use of Mangifera indica in kidney diseases. This study investigated the reno-modulatory roles of the aqueous stem bark extract of Mangifera indica (MIASE against CCl4-induced renal damage. Rats were treated intragastrically with 125, 250 and 500 mg/kg/day MIASE for 7 days before and after the administration of CCl4 (3 ml/kg of 30% CCl4, i.p.. Serum levels of electrolytes (Na+, K+, Cl−, HCO3−, urea and creatinine were determined. Renal tissue reduced glutathione (GSH, malondialdehyde (MDA, catalase (CAT, superoxide (SOD activities were also assessed. The histopathological changes in kidneys were determined using standard methods. In CCl4 treated rats the results showed significant (p<0.05 increases in serum Na+, K+, Cl−, urea and creatinine. CCl4 also caused significant (p<0.05 decreases in renal tissue SOD, CAT and GSH and significant (p<0.05 increases in MDA. The oral MIASE treatment (125–500 mg/kg was found to significantly (p<0.05 attenuate the increase in serum electrolytes, urea and creatinine. Similarly, MIASE significantly (p<0.05 attenuated the decrease in SOD, CAT and GSH levels and correspondingly attenuated increases in MAD. Mangifera indica may present a great prospect for drug development in the management of kidney disease with lipid peroxidation as its etiology.

  17. Trifluopromazine late preventive effects on carbon tetrachloride-induced liver necrosis.

    Science.gov (United States)

    de Ferreyra, E C; Bernacchi, A S; San Martin, M F; Castro, G D; Castro, J A

    1995-04-01

    Trifluopromazine (TFPro) administration to rats (50 mg/kg, ip) 30 min before or 6 or 10 hr after CCl4 treatment (1 ml/kg ip in olive oil) partially prevented necrogenic effects of this compound at 24 hr. TFPro has only minor effects on the covalent binding (CB) of CCl4-reactive metabolites to cellular constituents and even an enhancing action on CCl4-promoted lipid peroxidation (LP). Determination of TFPro levels in liver 1 and 3 hr after administration by gas chromatography/mass spectrometry showed its presence in that tissue at concentrations well above those needed for calmodulin (CaM) inhibitory effects of this drug. TFPro lowered body temperature in CCl4-treated animals during the 24-hr observation period. Protective effects of TFPro at 6 or 10 hr, when most of the CB and all of the LP has already occurred, suggest but do not prove a role for CaM in late stages of CCl4-induced necrogenic effects. Decreases in the body temperature of CCl4-poisoned animals provoked by TFPro might also play a role in the preventive actions of this drug. PMID:8549698

  18. Management of carbon tetrachloride-induced acute liver injury in rats by syngeneic hepatocyte transplantation in spleen and peritoneal cavity

    Institute of Scientific and Technical Information of China (English)

    Charalampos Pilichos; Despina Perrea; Maria Demonakou; Athena Preza; Ismini Donta

    2004-01-01

    AIM: Acute hepatitis may seldom have a fulminant course.In the treatment of this medical emergency, potential liver support measure must provide immediate and sufficient assistance to the hepatic function. The goal of our study was to study the adequacy of hepatocyte transplantation (HCTx) in two different anatomical sites, splenic parenchyma and peritoneal cavity, in a rat model of reversible acute hepatitis induced by carbon tetrachloride (CCl4).METHODS: After CCl4 intoxication, 84 male Wistar rats used as recipients were divided in to four experimental groups accordingly to their treatment: Group A (n=24): intrasplenic transplantation of 10x106 isolated hepatocytes, Group B (n=24):intraperitoneal transplantation of 20xL06 isolated hepatocytes attached on plastic microcarriers, Group C (n= 18): i ntrasplenic injection of 1 mL normal saline (sham-operated controls),Group D (n=18): intraperitoneal injection of 2.5 mL normal saline (sham-operated controls). Survival, liver function tests (LFT) and histology were studied in all four groups, on d 2,5 and 10 post-HCTx.RESULTS: The ten-day survival (and mean survival) in the 4 groups was 72.2% (8.1±3.1), 33.3% (5.4±3.4), 0%(3.1±1.3) and 33.3% (5.4±3.6) in groups A, B, C, D,respectively (PAB<0.05, PAC<0.05, PBD=NS). In the final survivors, LFT (except alkaline phosphatase) and hepatic histology returned to normal, independently of their previous therapy. Viable hepatocytes were identified within splenic parenchyma (in group A on d 2) and both in the native liver and the fatty tissue of abdominal wall (in group B on d 5).CONCLUSION: A significantly better survival of the intrasplenically transplanted animals has been demonstrated.Intraperitoneal hepatocytes failed to promptly engraft. A different timing between liver injury and intraperitoneal HCTx may give better results and merits further investigation.

  19. The Vitamine D3 Analogue (1α Hydroxyvitamin D3) Aggravates Carbon Tetrachloride-Induced Hepatotoxicity In Albino Rats

    International Nuclear Information System (INIS)

    Provitamin D, cholecalciferol, undergoes hydroxylation at the 25 and the 1α position in the liver and the kidney, respectively, before it turns into a hormonally active form regulating calcium homeostasis. The main purpose of the present study is to assess the potential of the 1α hydroxyvitamin D3 analogue to aggravate the ability of carbon tetrachloride (CCl4) to cause hepatotoxicity in albino rats. For this purpose, four groups of male albino rats, each of five, were used as follow: control group (G 1) received no treatment, CCl4 treated group (G 2) received CCl4 at a dose of 0.2 ml/100 g body weight in sunflower oil (1/1) v/v ratio two times per week for three weeks subcutaneously, 1α hydroxyvitamin D3 treated group (G 3) received a total dose of 5 ng/g body weight of 1α hydroxyvitamin D3 dissolved in propyl alcohol divided into six doses each given twice weekly for three weeks via the subcutaneous route, and CCl4 + 1α hydroxyvitamin D3 treated group (G 4) received the same dose of CCl4 and 1α hydroxyvitamin D3 concomitantly as previously described. Liver tissues from sacrificed animals were fixed in 10% formalin before sectioning and stained with eosin and hematoxyline then were examined histopathologically. Sera from control and treated animals were separated from blood and examined for ALT, AST, alkaline phosphatase and LDH levels. Serum total protein, albumin, globulin, A/G, bilirubin, creatinine, phosphorous and Ca levels were also monitored. Data from the present study showed that administration of 1α hydroxyvitamin D3 aggravated CCl4-induced hepatotoxicity as evidenced by the exacerbation of the rise in serum ALT, AST, alkaline phosphatase levels. The analogue, however, had no effect on serum liver enzymes in CCl4 untreated rats. Though, CCl4 caused significant impairment of kidney function as shown by the rise in serum creatinine and urea levels which were differentially affected by the analogue. In conclusion, the 1α hydroxyvitamin D3 compound

  20. Hepatoprotective potential of Aloe barbadensis Mill. against carbon tetrachloride induced hepatotoxicity.

    Science.gov (United States)

    Chandan, B K; Saxena, A K; Shukla, Sangeeta; Sharma, Neelam; Gupta, D K; Suri, K A; Suri, Jyotsna; Bhadauria, M; Singh, B

    2007-05-22

    Aloe barbadensis Mill. Syn. Aloe vera Tourn. ex Linn.(Liliaceae) has been used in variety of diseases in traditional Indian system of medicine in India and its use for hepatic ailments is also documented. In the present study an attempt has been made to validate its hepatoprotective activity. The shade dried aerial parts of Aloe barbadensis were extracted with petroleum ether (AB-1), chloroform (AB-2) and methanol (AB-3). The plant marc was extracted with distilled water (AB-4). All the extracts were evaluated for hepatoprotective activity on limited test models as hexobarbitone sleep time, zoxazolamine paralysis time and marker biochemical parameters. AB-1 and AB-2 were observed to be devoid of any hepatoprotective activity. Out of two active extracts (AB-3 and AB-4), the most active AB-4 was studied in detail. AB-4 showed significant hepatoprotective activity against CCl4 induced hepatotoxicity as evident by restoration of serum transaminases, alkaline phosphatase, bilirubin and triglycerides. Hepatoprotective potential was confirmed by the restoration of lipid peroxidation, glutathione, glucose-6-phosphatase and microsomal aniline hydroxylase and amidopyrine N-demethylase towards near normal. Histopathology of the liver tissue further supports the biochemical findings confirming the hepatoprotective potential of AB-4. The present study shows that the aqueous extract of Aloe barbadensis is significantly capable of restoring integrity of hepatocytes indicated by improvement in physiological parameters, excretory capacity (BSP retention) of hepatocytes and also by stimulation of bile flow secretion. AB-4 did not show any sign of toxicity up to oral dose of 2 g/kg in mice.

  1. High-fat diet plus carbon tetrachloride-induced liver fibrosis is alleviated by betaine treatment in rats.

    Science.gov (United States)

    Bingül, İlknur; Aydın, A Fatih; Başaran-Küçükgergin, Canan; Doğan-Ekici, Işın; Çoban, Jale; Doğru-Abbasoğlu, Semra; Uysal, Müjdat

    2016-10-01

    Steatosis, the first lesion in non-alcoholic fatty liver disease (NAFLD), may progress to fibrosis, cirrhosis, and hepatocellular carcinoma. Steatosis predisposes the liver to oxidative stress, inflammation, and cytokines. Betaine (BET) has antioxidant, antiinflammatory and hepatoprotective effects. However, the effects of BET on liver fibrosis development are unknown. Rats were treated with high-fat diet (60% of total calories from fat) for 14weeks. Carbon tetrachloride (0.2mL/kg; two times per week; i.p.) was administered to rats in the last 6weeks with/without commercial food containing BET (2%; w/w). Serum liver function tests and tumor necrosis factor-α, insulin resistance, hepatic triglyceride (TG) and hydroxyproline (HYP) levels and oxidative stress parameters were determined along with histopathologic observations. Alpha-smooth muscle-actin (α-SMA), transforming growth factor-β1 (TGF-β1) and type I collagen (COL1A1) protein expressions and mRNA expressions of matrix metalloproteinase-2 (MMP-2) and its inhibitors (TIMP-1 and TIMP-2) were evaluated. BET decreased TG and HYP levels, prooxidant status and fibrotic changes in the liver. α-SMA, COL1A1 and TGF-β1 protein expressions, MMP-2, TIMP-1, and TIMP-2 mRNA expressions diminished due to BET treatment. BET has an antifibrotic effect and this effect may be related to its antioxidant and antiinflammatory actions together with suppression on HSC activation.

  2. Effects of carbon tetrachloride and azathioprine on diethylnitrosamine and N-2-fluorenylacetamide-induced hyperplastic liver nodule and hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Sakata,Tatsuro

    1984-12-01

    Full Text Available Effects of carbon tetrachloride (CCl4 and azathioprine (AZP on the evolution of hyperplastic liver nodules and foci and hepatocellular carcinoma (HCC were tested in short- and long-term in vivo experiments. In diethylnitrosamine (DEN-treated rats, which were fed a N-2-fluorenylacetamide (FAA-containing diet and additionally treated with repeated CCl4 injections, gamma-glutamyl transpeptidase (gamma-GTP-positive hyperplastic nodules were markedly developed in the 8th week of the experiment. However, their number and area in liver sections were remarkably small in DEN-treated rats fed a diet containing both FAA and AZP. Increased area of gamma-GTP-positive foci was also observed in the 12th week in DEN-injected rats fed a choline-devoid died alone or treated with repeated doses of CCl4 alone. Hepatocellular carcinoma in DEN-injected rats treated with both FAA and CCl4 was first detected in the 21st week, and the incidence up to the 36th week was very high. However, no hepatocellular carcinoma developed in DEN-injected rats treated with both FAA and AZP. The increased activity of liver aniline hydroxylase observed 12 h after the administration of FAA, AZP or DEN alone was not observed when AZP was administered simultaneously with FAA to DEN-injected rats. The mechanisms of the effects of CCl4 and AZP on hepatocarcinogenesis are discussed with special reference to drug interaction.

  3. Chemical Composition, Antimicrobial Activity of Propolis Ethanolic Extract and Its Improving Role of Biochemical Changes Induced by Carbon tetrachloride in Male Albino Rats

    International Nuclear Information System (INIS)

    Propolis (bee glue) is a sticky substance that is collected from plants by honeybees. Due to biological and pharmacological activities, it has been extensively used in folk medicine. The purpose of this study was to investigate the chemical composition, the antimicrobial activity and possible protective effects of ethanolic extract of propolis on carbon tetrachloride (CCl4)-induced biological damages in rats. The studied rats were allotted to four equal groups (6 rats each) : Group 1 served as control and was given the vehicle (Tween 80 dissolved in distilled water, 1:100 ) orally for 21 consecutive days after which they were sacrificed , group 2 treated orally with ethanolic extract of popolis (100μg/rat) for 21 successive days, group 3 ( CCl4 - treated group) administered orally with a single dose (0.5 ml/kg body weight) of carbon tetrachloride (mixed with an equal volume of olive oil) and group 4 (protected group) was treated with propolis extract (100μg/rat) for 21 successive days, after one hour of the last dose of the treatment, a single dose of CCl4 (0.5 ml/kg body weight) was given. Then all animals were sacrificed, 24 hr post experimental design period for each group. Our results revealed that, fourteen compounds were identified by chromatography-mass spectrometry analysis (GC- MS analysis). Propolis ethanolic extract inhibited the growth of six from the tested microorganisms including bacteria and fungi at 5 mg/ml against E. coli and B. subtilis and 20 mg/ml against S. aureus, P. aeruginosa, Penicillium italicum and Candida albicans, while it has no effect on A. fumigatus and Syncephalstrum racemasum. In experimental animals, Leucocytic counts and platelets, in addition, AST, ALT, CK and LDH were significantly increased, meanwhile, triiodothyronine (T3) and thyroxine (T4) level was decreased in CCl4 treated rats (group 3) compared to the control (group 1). Protection with ethanolic extract of propolis to rats received CCl4 (group 4) ameliorated the

  4. Hydrodynamic Gene Delivery of Interleukin-22 Protects the Mouse Liver from Concanavalin A-, Carbon Tetrachloride-, and Fas Ligand-Induced Injury via Activation of STAT3

    Institute of Scientific and Technical Information of China (English)

    HongnaPan; FengHong; SvetlanaRadaeva; BinGao

    2004-01-01

    Interleukin-22 (IL-22) is a recently identified T cell-derived cytokine whose biological significance remains obscure. Previously, we have shown that IL-22 plays a protective role in T cell-mediated hepatitis induced by Concanavalin A (Con A), acting as a survival factor for hepatocytes. In the present paper, we demonstrate that hydrodynamic gene delivery of IL-22 cDNA driven either by a liver-specific albumin promoter or a human cytomegalovirus (CMV) promoter results in IL-22 protein expression, STAT3 activation, and expression of several anti-apoptotic proteins, including Bcl-xL, Bcl-2, and Mcl-1 in the liver. Immunohistochemical analysis reveals that IL-22 protein expression is mainly detected in the cytoplasm of hepatocytes. Overexpression of IL-22 by hydrodynamic gene delivery significantly protects against liver injury, necrosis, and apoptosis induced by administration of Con A, carbon tetrachloride (CCl4), or the Fas agonist Jo-2 mAb. Western blot analyses show that overexpression of IL-22 significantly enhances activation of STAT3 and expression of Bcl-xL, Bcl-2, and Mcl-1 proteins in liver injury induced by Con A. In conclusion, hydrodynamic gene delivery of IL-22 protects against liver injury induced by a variety of toxins, suggesting the therapeutic potential of IL-22 in treating human liver disease. Cellular & Molecular Immunology. 2004;1(1):43-49.

  5. Hydrodynamic Gene Delivery of Interleukin-22 Protects the Mouse Liver from Concanavalin A-, Carbon Tetrachloride-, and Fas Ligand-Induced Injury via Activation of STAT3

    Institute of Scientific and Technical Information of China (English)

    Hongna Pan; Feng Hong; Svetlana Radaeva; Bin Gao

    2004-01-01

    Interleukin-22 (IL-22) is a recently identified T cell-derived cytokine whose biological significance remains obscure. Previously, we have shown that IL-22 plays a protective role in T cell-mediated hepatitis induced by Concanavalin A (Con A), acting as a survival factor for hepatocytes. In the present paper, we demonstrate that hydrodynamic gene delivery of IL-22 cDNA driven either by a liver-specific albumin promoter or a human cytomegalovirus (CMV) promoter results in IL-22 protein expression, STAT3 activation, and expression of several anti-apoptotic proteins, including Bcl-xL, Bcl-2, and Mcl-1 in the liver. Immunohistochemical analysis reveals that IL-22 protein expression is mainly detected in the cytoplasm of hepatocytes. Overexpression of IL-22 by hydrodynamic gene delivery significantly protects against liver injury, necrosis, and apoptosis induced by administration of Con A, carbon tetrachloride (CCl4), or the Fas agonist Jo-2 mAb. Western blot analyses show that overexpression of IL-22 significantly enhances activation of STAT3 and expression of Bcl-xL, Bcl-2,and Mcl-1 proteins in liver injury induced by Con A. In conclusion, hydrodynamic gene delivery of IL-22 protects against liver injury induced by a variety of toxins, suggesting the therapeutic potential of IL-22 in treating human liver disease. Cellular & Molecular Immunology. 2004;1(1):43-49.

  6. Carbon Tetrachloride Emissions from the Amazon Forest

    Science.gov (United States)

    Jardine, K.; Chambers, J. Q.; Higuchi, N.; Jardine, A. B.; Martin, S. T.; Manzi, A. O.

    2014-12-01

    As a chemically inert greenhouse gas in the troposphere with lifetimes up to 50 years but active in ozone destruction in the stratosphere, carbon tetrachloride (CCl4) plays a major role in the atmospheric chlorine budget and is widely considered strictly of anthropogenic origin deriving from numerous industrial processes and products. However, satellite remote sensing studies have shown higher concentrations at the Equator, and earlier work has suggested possible biogenic sources. Here we present highly vertically-resolved atmospheric gradients of CCl4 within and above a primary rainforest ecosystem from three towers in the Central Amazon. The observed buildup of CCl4 mixing ratios near the top of the main canopies provides new evidence for a potentially large biogenic source from the Basin. By demonstrating the need to represent tropical forests as biogenic sources of CCl4, our study may help narrow the gap between remote sensing observations of CCl4 and emission, chemistry, and transport models and therefore lead to improved predictions of its role in atmospheric chemistry and climate.

  7. The Protective Properties of the Strawberry (Fragaria ananassa) against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Mediated by Anti-Apoptotic and Upregulation of Antioxidant Genes Expression Effects

    Science.gov (United States)

    Hamed, Sherifa S.; AL-Yhya, Nouf A.; El-Khadragy, Manal F.; Al-Olayan, Ebtesam M.; Alajmi, Reem A.; Hassan, Zeinab K.; Hassan, Salwa B.; Abdel Moneim, Ahmed E.

    2016-01-01

    The strawberry (Fragaria ananassa) has been extensively used to treat a wide range of ailments in many cultures. The present study was aimed at evaluating the hepatoprotective effect of strawberry juice on experimentally induced liver injury in rats. To this end, rats were introperitoneally injected with carbon tetrachloride (CCl4) with or without strawberry juice supplementation for 12 weeks and the hepatoprotective effect of strawberry was assessed by measuring serum liver enzyme markers, hepatic tissue redox status and apoptotic markers with various techniques including biochemistry, ELISA, quantitative PCR assays and histochemistry. The hepatoprotective effect of the strawberry was evident by preventing CCl4-induced increase in liver enzymes levels. Determination of oxidative balance showed that strawberry treatment significantly blunted CCl4-induced increase in oxidative stress markers and decrease in enzymatic and non-enzymatic molecules in hepatic tissue. Furthermore, strawberry supplementation enhanced the anti-apoptotic protein, Bcl-2, and restrained the pro-apoptotic proteins Bax and caspase-3 with a marked reduction in collagen areas in hepatic tissue. These findings demonstrated that strawberry (F. ananassa) juice possessed antioxidant, anti-apoptotic and anti-fibrotic properties, probably mediated by the presence of polyphenols and flavonoids compounds. PMID:27547187

  8. Negundoside, an irridiod glycoside from leaves of Vitex negundo, protects human liver cells against calcium-mediated toxicity induced by carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    Sheikh A Tasduq; Peerzada J Kaiser; Bishan D Gupta; Vijay K Gupta; Rakesh K Johri

    2008-01-01

    AIM: To evaluate the protective effect of 2'-p-hydroxy benzoylmussaenosidic acid [negundoside (NG), against carbon tetrachloride (CCl4)-induced toxicity in HUH-7 cells.METHODS: CCl4 is a well characterized hepatotoxin, and inducer of cytochrome P4502E1 (CYP2E1)-mediated oxidative stress. In addition, lipid peroxidation and accumulation of intracellular calcium are important steps in the pathway involved in CCl4 toxicity. Liver cells (HUH-7) were treated with CCl4, and the mechanism of the cytoprotective effect of NG was assessed. Silymarin, a known hepatoprotective drug, was used as control.RESULTS: NG protected HUH-7 cells against CCl4 toxicity and loss of viability without modulating CYP2E1 activity. Prevention of CCl4, toxicity was associated with a reduction in oxidative damage as reflected by decreased generation of reactive oxygen species (ROS), a decrease in lipid peroxidation and accumulation of intracellular Ca2+ levels and maintenance of intracellular glutathione homeostasis. Decreased mitochondrial membrane potential (MMP), induction of caspases mediated DNA fragmentation and cell cycle arrest, as a result of CCl4 treatment, were also blocked by NG. The protection afforded by NG seemed to be mediated by activation of cyclic adenosine monophosphate (cAMP) synthesis and inhibition of phospholipases (cPLA2).CONCLUSION: NG exerts a protective effect on CYP2El-dependent CCl4 toxicity via inhibition of lipid peroxidation, followed by an improved intracellular calcium homeostasis and inhibition of Ca2+-dependent proteases.

  9. A virus-like particle-based connective tissue growth factor vaccine suppresses carbon tetrachloride-induced hepatic fibrosis in mice.

    Science.gov (United States)

    Li, Shuang; Lv, Yi-Fei; Su, Hou-Qiang; Zhang, Qian-Nan; Wang, Li-Rong; Hao, Zhi-Ming

    2016-01-01

    Connective tissue growth factor (CTGF) has been recognized as a central mediator and promising therapeutic target in hepatic fibrosis. In this study, we generated a novel virus-like particle (VLP) CTGF vaccine by inserting the 138-159 amino acid (aa) fragment of CTGF into the central c/e1 epitope of C-terminus truncated hepatitis B virus core antigen (HBc, aa 1-149) using a prokaryotic expression system. Immunization of BALB/c mice with the VLP vaccine efficiently elicited the production of anti-CTGF neutralizing antibodies. Vaccination with this CTGF vaccine significantly protected BALB/c mice from carbon tetrachloride (CCl4)-induced hepatic fibrosis, as indicated by decreased hepatic hydroxyproline content and lower fibrotic score. CCl4 intoxication-induced hepatic stellate cell activation was inhibited by the vaccination, as indicated by decreased α-smooth muscle actin expression and Smad2 phosphorylation. Vaccination against CTGF also attenuated the over-expression of some profibrogenic factors, such as CTGF, transforming growth factor-β1, platelet-derived growth factor-B and tissue inhibitor of metalloproteinase-1 in the fibrotic mouse livers, decreased hepatocyte apoptosis and accelerated hepatocyte proliferation in the fibrotic mouse livers. Our results clearly indicate that vaccination against CTGF inhibits fibrogenesis, alleviates hepatocyte apoptosis and facilitate hepatic regeneration. We suggest that the vaccine should be developed into an effective therapeutic measure for hepatic fibrosis. PMID:27562139

  10. Chloroquine improved carbon tetrachloride-induced liver fibrosis through its inhibition of the activation of hepatic stellate cells: role of autophagy.

    Science.gov (United States)

    He, Wei; Wang, Bin; Yang, Jing; Zhuang, Yun; Wang, Liangzhi; Huang, Xiaodan; Chen, Jianping

    2014-01-01

    Autophagy is involved in the activation of hepatic stellate cells (HSCs), which is the key process of liver fibrosis. We reasoned that chloroquine, based on its ability to inhibit autophagy, might exert beneficial effects in liver fibrosis. Liver fibrosis in rats was induced by carbon tetrachloride (CCl4). Rats were divided into three groups, a normal control group (N group), model group (M group), and chloroquine group (CQ group). Liver fibrosis in the rats was evaluated by hematoxyline-eosin (H&E) and Masson staining. The activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TB) were determined using an automated biochemistry analyzer. Total hepatic hydroxyproline levels were determined with a kit. The expressions of α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) were detected by immunofluorescence staining, and the expressions of LC3-II and p62 were determined by Western blotting. Compared with N group, M group showed impaired liver function, liver fibrosis, increased hydroxyproline content, up-regulated expressions of α-SMA and TGF-β1, which have been reported to be pro-fibrogenic genes in vivo, and increased autophagy flux as indicated by the accumulation of LC3-II and degradation of p62. These changes were attenuated by chloroquine treatment. Chloroquine exerts beneficial effects in CCl4-induced liver fibrosis. The mechanism of action includes inhibition of autophagy pathways and inhibition of activation of HSCs. PMID:25177034

  11. Potential Probiotic Escherichia coli 16 Harboring the Vitreoscilla Hemoglobin Gene Improves Gastrointestinal Tract Colonization and Ameliorates Carbon Tetrachloride Induced Hepatotoxicity in Rats

    Directory of Open Access Journals (Sweden)

    Prasant Kumar

    2014-01-01

    Full Text Available The present study describes the beneficial effects of potential probiotic E. coli 16 (pUC8:16gfp expressing Vitreoscilla hemoglobin (vgb gene, associated with bacterial respiration under microaerobic condition, on gastrointestinal (GI colonization and its antioxidant activity on carbon tetrachloride (CCl4 induced toxicity in Charles Foster rats. In vitro, catalase activity in E. coli 16 (pUC8:16gfp was 1.8 times higher compared to E. coli 16 (pUC-gfp control. In vivo, E. coli 16 (pUC8:16gfp not only was recovered in the fecal matter after 70 days of oral administration but also retained antibacterial activities, whereas E. coli 16 (pUC-gfp was not detected. Oral administration of 200 and 500 μL/kg body weight of CCl4 to rats at weekly interval resulted in elevated serum glutamyl pyruvate transaminase (SGPT and serum glutamyl oxalacetate transaminase (SGOT levels compared to controls. Rats prefed with E. coli 16 (pUC8:16gfp demonstrated near to normal levels for SGPT and SGOT, whereas the liver homogenate catalase activity was significantly increased compared to CCl4 treated rats. Thus, pUC8:16gfp plasmid encoding vgb improved the growth and GI tract colonization of E. coli 16. In addition, it also enhanced catalase activity in rats harboring E. coli 16 (pUC8:16gfp, thereby preventing the absorption of CCl4 to GI tract.

  12. Phytochemical analysis, hepatoprotective and antioxidant activity of Alchornea cordifolia methanol leaf extract on carbon tetrachloride-induced hepatic damage in rats

    Institute of Scientific and Technical Information of China (English)

    Patience O Osadebe; Festus BC Okoye; Philip F Uzor; Nneka R Nnamani; Ijeoma E Adiele; Nkemakonam C Obiano

    2012-01-01

    ABSTRACT Objective:To investigate the hepatoprotective and antioxidant activities ofAlchornea cordifolia (A. cordifolia) leaf extract.Methods: Various solvent fractions of the methanol extract of the leaf of the plantA. cordifolia Mull. Arg (Fam: Euphorbiaceae) were evaluated for hepatoprotective activity by carbon tetrachloride-induced liver damage in rats. The degree of protection was measured by using biochemical parameters such as serum glutamate oxalate transaminase(SGOT/AST), serum glutamate pyruvate transaminase(SGPT/ALT), alkaline phosphatase(ALP) and total bilirubin. Thein vitro antioxidant activity of the extract was also evaluated by the 1, 1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging assay. The extract was subjected to preliminary phytochemical screening.Results:The ethyl acetate and chloroform fractions, at a dose of 300mg/kg, produced significant(P<0.05) hepatoprotection by decreasing the activities of the serum enzymes and bilirubin while there were marked scavenging of the DPPH free radicals by the fractions. The effects were comparable to those of the standard drugs used for the respective experiments, silymarin and ascorbic acid. Alkaloids, flavonoids, saponins and tannins were detected in the phytochemical screening.Conclusion: From this study, it was concluded that the plant ofA. cordifolia possesses hepatoprotective as well as antioxidant activities and these activities reside mainly in the ethyl acetate and acetone fractions of methanol leaf extract.

  13. IMPROVED RISK ESTIMATES FOR CARBON TETRACHLORIDE

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Janet M.; Springer, David L.

    1999-12-31

    Carbon tetrachloride has been used extensively within the DOE nuclear weapons facilities. Rocky Flats was formerly the largest volume consumer of CCl4 in the United States using 5000 gallons in 1977 alone (Ripple, 1992). At the Hanford site, several hundred thousand gallons of CCl4 were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl4 in groundwater at highly contaminated sites at the Hanford facility have exceeded 8 the drinking water standard of 5 ppb by several orders of magnitude (Illman, 1993). High levels of CCl4 at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl4 cleanup required at these sites and associated costs are driven by current human health risk estimates, which assume that CCl4 is a genotoxic carcinogen. The overall purpose of these studies was to improve the scientific basis for assessing the health risk associated with human exposure to CCl4. Specific research objectives of this project were to: (1) compare the rates of CCl4 metabolism by rats, mice and hamsters in vivo and extrapolate those rates to man based on parallel studies on the metabolism of CCl4 by rat, mouse, hamster and human hepatic microsomes in vitro; (2) using hepatic microsome preparations, determine the role of specific cytochrome P450 isoforms in CCl4-mediated toxicity and the effects of repeated inhalation and ingestion of CCl4 on these isoforms; and (3) evaluate the toxicokinetics of inhaled CCl4 in rats, mice and hamsters. This information has been used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). Another major objective of the project was to provide scientific evidence that CCl4, like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing and regenerative proliferation. In

  14. Assessment of Carbon Tetrachloride Groundwater Transport in Support of the Hanford Carbon Tetrachloride Innovative Technology Demonstration Program

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Murray, Christopher J.; Cole, Charles R.; Cameron, Richard J.; Johnson, Michael D.; Skeen, Rodney S.; Johnson, Christian D.

    2001-07-13

    Groundwater modeling was performed in support of the Hanford Carbon Tetrachloride Innovative Treatment Remediation Demonstration (ITRD) Program. The ITRD program is facilitated by Sandia National Laboratory for the Department of Energy Office of Science and Technology. This report was prepared to document the results of the modeling effort and facilitate discussion of characterization and remediation options for the carbon tetrachloride plume among the ITRD participants. As a first step toward implementation of innovative technologies for remediation of the carbon tetrachloride (CT) plume underlying the 200-West Area, this modeling was performed to provide an indication of the potential impact of the CT source on the compliance boundary approximately 5000 m distant. The primary results of the modeling bracket the amount of CT source that will most likely result in compliance/non-compliance at the boundary and the relative influence of the various modeling parameters.

  15. Hepatic Progenitor Cells Contribute to the Progression of 2-Acetylaminofluorene/Carbon Tetrachloride-Induced Cirrhosis via the Non-Canonical Wnt Pathway.

    Directory of Open Access Journals (Sweden)

    Jiamei Chen

    Full Text Available Hepatic progenitor cells (HPCs appear to play an important role in chronic liver injury. In this study, cirrhosis was induced in F-344 rats (n = 32 via subcutaneous injection of 50% carbon tetrachloride (CCl4 twice a week for 8 weeks. Then, 30% CCl4 was administered in conjunction with intragastric 2-acetylaminofluorine (2-AAF for 4 weeks to induce activation of HPCs. WB-F344 cells were used to provide direct evidence for differentiation of HPCs to myofibroblasts. The results showed that after administration of 2-AAF, the hydroxyproline content and the expressions of α-SMA, Col I, Col IV, TGF-β1, CD68, TNF-α, CK19 and OV6 were significantly increased. OV6 and α-SMA were largely co-expressed in fibrous septum and the expressions of Wnt5b, frizzled2, frizzled3 and frizzled6 were markedly increased, while β-catenin expression was not statistically different among the different groups. Consistent with the above results, WB-F344 cells, treated with TGF-β1 in vitro, differentiated into myofibroblasts and α-SMA, Col I, Col IV, Wnt5b and frizzled2 expressions were significantly increased, while β-catenin expression was decreased. After blocking the non-canonical Wnt pathway via WIF-1, the Wnt5b level was down regulated, and α-SMA and F-actin expressions were significantly decreased in the WIF-1-treated cells. In conclusion, these results indicate that HPCs appear to differentiate into myofibroblasts and exhibit a profibrotic effect in progressive cirrhosis via activation of the non-canonical Wnt pathway. Blocking the non-canonical Wnt pathway can inhibit the differentiation of HPCs into myofibroblasts, suggesting that blocking this pathway and changing the fate of differentiated HPCs may be a potential treatment for cirrhosis.

  16. Hepatic Progenitor Cells Contribute to the Progression of 2-Acetylaminofluorene/Carbon Tetrachloride-Induced Cirrhosis via the Non-Canonical Wnt Pathway.

    Science.gov (United States)

    Chen, Jiamei; Zhang, Xiao; Xu, Ying; Li, Xuewei; Ren, Shuang; Zhou, Yaning; Duan, Yuyou; Zern, Mark; Zhang, Hua; Chen, Gaofeng; Liu, Chenghai; Mu, Yongping; Liu, Ping

    2015-01-01

    Hepatic progenitor cells (HPCs) appear to play an important role in chronic liver injury. In this study, cirrhosis was induced in F-344 rats (n = 32) via subcutaneous injection of 50% carbon tetrachloride (CCl4) twice a week for 8 weeks. Then, 30% CCl4 was administered in conjunction with intragastric 2-acetylaminofluorine (2-AAF) for 4 weeks to induce activation of HPCs. WB-F344 cells were used to provide direct evidence for differentiation of HPCs to myofibroblasts. The results showed that after administration of 2-AAF, the hydroxyproline content and the expressions of α-SMA, Col I, Col IV, TGF-β1, CD68, TNF-α, CK19 and OV6 were significantly increased. OV6 and α-SMA were largely co-expressed in fibrous septum and the expressions of Wnt5b, frizzled2, frizzled3 and frizzled6 were markedly increased, while β-catenin expression was not statistically different among the different groups. Consistent with the above results, WB-F344 cells, treated with TGF-β1 in vitro, differentiated into myofibroblasts and α-SMA, Col I, Col IV, Wnt5b and frizzled2 expressions were significantly increased, while β-catenin expression was decreased. After blocking the non-canonical Wnt pathway via WIF-1, the Wnt5b level was down regulated, and α-SMA and F-actin expressions were significantly decreased in the WIF-1-treated cells. In conclusion, these results indicate that HPCs appear to differentiate into myofibroblasts and exhibit a profibrotic effect in progressive cirrhosis via activation of the non-canonical Wnt pathway. Blocking the non-canonical Wnt pathway can inhibit the differentiation of HPCs into myofibroblasts, suggesting that blocking this pathway and changing the fate of differentiated HPCs may be a potential treatment for cirrhosis. PMID:26087010

  17. Dose response and time course studies on superoxide dismutase as a urinary biomarker of carbon tetrachloride-induced hepatic injury in the Hanover Wistar rat.

    Science.gov (United States)

    Smyth, Rosemary; Munday, Michael R; York, Malcolm J; Clarke, Christopher J; Dare, Theo; Turton, John A

    2009-10-01

    Previous studies have shown that the enzyme copper/zinc superoxide dismutase (SOD-1) is increased in the urine of rats with carbon tetrachloride (CCl(4))-induced hepatotoxicity. The present experiments aimed to investigate further the usefulness of urinary SOD-1 as a non-invasive biomarker of liver injury. Two investigations were carried out, a dose response study and a time course study. In the dose response study, rats were given a single dose of CCl(4) at 0 (control), 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40 and 0.80 ml/kg and urine samples collected from 12 to 36 h postdosing. In the time course study, rats were dosed at 0.80 ml/kg CCl(4) and urine sampled at 4, 12, 24 and 36 h postdosing. In both studies, the presence of SOD-1 in the urine was confirmed by Western blotting with an SOD-1 antibody. In the dose response study, serum SOD activity was elevated in all CCl(4)-treated animals and urinary SOD-1 activity was increased 2.2 times at the lowest dose (0.10 ml/kg) and 60.4 times at the highest CCl(4) dose level (0.80 ml/kg). In the time course study, urinary SOD-1 was first detected in samples collected from 4 to 12 h postdosing. We conclude that urinary SOD-1 has potential as a sensitive non-invasive biomarker of CCl(4)-induced hepatocellular injury.

  18. Development of quercetin-phospholipid complex to improve the bioavailability and protection effects against carbon tetrachloride-induced hepatotoxicity in SD rats.

    Science.gov (United States)

    Zhang, Kexia; Zhang, Meiyu; Liu, Ziying; Zhang, Yuanyuan; Gu, Liqiang; Hu, Gaosheng; Chen, Xiaohui; Jia, Jingming

    2016-09-01

    Quercetin (QT) is a natural flavonoid with various biological activities and pharmacological actions. However, the bioavailability of QT is relatively low due to its low solubility which severely limits its use. In this study, we intended to improve the bioavailability of QT by preparing quercetin-phospholipid complex (QT-PC) and investigate the protective effect of QT-PC against carbon tetrachloride (CCl4) induced acute liver damage in Sprague-Dawley (SD) rats. The physicochemical properties of QT-PC were characterized in terms of infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), powder X-ray diffraction (XRPD) and water/n-octanol solubility. FTIR, DSC and XRPD data confirmed the formation of QT-PC. The water solubility of QT was improved significantly in the prepared complex, indicating its increased hydrophilicity. Oral bioavailability of QT and QT-PC was evaluated in SD rats, and the plasma QT was estimated by HPLC-MS. QT-PC exhibited higher Cmax (1.58±0.11 vs. 0.67±0.08μg/mL), increased AUC0-∞ (8.60±1.25 vs. 2.41±0.51mg/Lh) and t1/2z (7.76±1.09 vs. 4.81±0.87h) when compared to free QT. The greater absorption of QT-PC group suggested the improved bioavailability. Moreover, biochemical changes and histopathological observations revealed that QT-PC provided better protection to rat liver than free QT at the same dose. Thus, phospholipid complexation might be one of the suitable approaches to improve the oral bioavailability of QT and obtain better protective effects against CCl4 induced acute liver damage in SD rats than free QT at the same dose level. PMID:27431774

  19. Effects of Peppermint (Mentha piperita L. Alcoholic Extract on Carbon Tetrachloride-induced Hepatotoxicity in Broiler Chickens Under Heat Stress Condition

    Directory of Open Access Journals (Sweden)

    Khodadust MR

    2015-06-01

    Full Text Available In order to investigate the effects of peppermint (Mentha piperita L. alcoholic extract on liver injury caused by the oxidant carbon tetrachloride (CCl4, an experiment was performed as a completely randomized design in a factorial arrangement (2 × 2 with 4 replications of 10 broilers each. Factors included two levels of peppermint leaf alcoholic extract (0 and 2 mL/Kg body weight and CCl4 (0 and 1 mL/Kg body weight. Results showed significant (P interactions for body weight gain (BWG, feed intake (FI and feed conversion ratio (FCR on d 42 of the experiment. The alcoholic extract of peppermint leaf did not improve growth performance, whereas CCl4 worsened BWG and FCR (P. The interaction between peppermint extract and CCl4 indicated an ameliorative effect of peppermint extract on BWG and FCR (P. The interaction effects between peppermint extract and CCl4 significantly differed for blood serum concentrations of total protein, albumin, albumin:globulin ratio, glucose, triglyceride, total cholesterol, HDLC, LDLC, LDLC:HDLC ratio, and VLDLC as well as the amount of blood liver enzymes (P. Peppermint extract significantly increased blood serum concentrations of total protein, albumin, triglyceride and HDLC, whilst CCl4 decreased those concentrations (P. Blood serum concentrations of total cholesterol, LDLC, LDLC:HDLC ratio, VLDLC and glucose were decreased by peppermint extract, whereas those concentrations were increased by CCl4 (P. A significantly higher level of liver enzymes was found in blood serum of birds treated by CCl4 than those by peppermint extract (P. A moderate effect on blood serum liver enzymes was observed by the interaction between 2 mL of peppermint extract and 1 mL of CCl4 (P. Generally, this study indicated that in vivo administration of peppermint alcoholic extract ameliorated the adverse effects of CCl4 on growth performance and liver function, therefore it might be useful for the prevention of oxidative stress-induced

  20. Histopathological And Histochemical Studies On The Effect Of Taurine In Preventing Carbon Tetrachloride ­Induced Hepatic InjuryIn The Albino Rat

    OpenAIRE

    Nabila, S. Hassan, Naglaa, F. Abbas And Hafiza, A. Sharaf

    2003-01-01

    Taurine is an amino acid­ like compound, it is found mostly in meat and fish.This study was designed to evaluate the effects of carbon tetrachloride (CCL4) on liver Histopathological & Histochemical changes and the protective role of taurine (2amino-ethanosulfonic acid ) was studied . Fourty two albino rats were divided into seven groups : control, taurine alone (200mg/kg), CCL4 alone, CCL4 plus 50mg/kg of taurine, CCL4 plus 100mg/kg of taurine, CCL4 plus 200mg/kg of taurine (taurine was inje...

  1. Endogenous hydrogen sulfide is associated with angiotensin II type 1 receptor in a rat model of carbon tetrachloride-induced hepatic fibrosis

    Science.gov (United States)

    FAN, HUI-NING; CHEN, NI-WEI; SHEN, WEI-LIN; ZHAO, XIANG-YUN; ZHANG, JING

    2015-01-01

    The present study aimed to investigate the effects of endogenous hydrogen sulfide (H2S) on the expression levels of angiotensin II type 1 receptor (AGTR1) in a rat model of carbon tetrachloride (CCl4)-induced hepatic fibrosis. A total of 56 Wistar rats were randomly divided into four groups: Normal control group, model group, sodium hydrosulfide (NaHS) group, and DL-propargylglycine (PAG) group. Hepatic fibrosis was induced by CCl4. The rats in the PAG group were intraperitoneally injected with PAG, an inhibitor of cystathionine-γ-lyase (CSE). The rats in the NaHS group were intraperitoneally injected with NaHS. An equal volume of saline solution was intraperitoneally injected into both the control and model groups. All rats were sacrificed at week three or four following treatment. The serum levels of hyaluronidase (HA), laminin protein (LN), procollagen III (PcIII), and collagen IV (cIV) were detected using ELISA. The serum levels of alanine transaminase (ALT), aspartate transaminase (AST), and albumin (ALB) were detected using an automatic biochemical analyzer. The liver mRNA expression levels of CSE were detected by reverse transcription-quantitative polymerase chain reaction. The liver expression levels of AGTR1 and the plasma expression levels of H2S were detected using western blot analyses. The results indicated that the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly higher in the PAG group, as compared with the model group (P<0.05). Conversely, the expression levels of ALB were significantly lower in the PAG group, as compared with the model group. In addition, the severity of hepatic fibrosis, the serum expression levels of HA, LN, PcIII, cIV, ALT, and AST, the liver expression levels of CSE and AGTR1, and the plasma expression levels of H2S were significantly lower in the NaHS group, as compared with

  2. The Potential Protective Effect of Physalis peruviana L. against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Is Mediated by Suppression of Oxidative Stress and Downregulation of MMP-9 Expression

    OpenAIRE

    Al-Olayan, Ebtisam M.; El-Khadragy, Manal F.; Aref, Ahmed M.; Othman, Mohamed S.; Kassab, Rami B.; Ahmed E. Abdel Moneim

    2014-01-01

    The active constituent profile in Cape gooseberry (Physalis peruviana L.) juice was determined by GC-MS. Quercetin and kaempferol were active components in the juice. In this study we have evaluated its potential protective effect on hepatic injury and fibrosis induced by carbon tetrachloride (CCl4). Twenty-eight rats divided into 4 groups: Group I served as control group, and Group II received weekly i.p. injection of 2 mL CCl4/kg bwt for 12 weeks. Group III were supplemented with Physalis j...

  3. Preliminary studies on antihepatotoxic effect of Physalis peruviana Linn. (Solanaceae) against carbon tetrachloride induced acute liver injury in rats.

    Science.gov (United States)

    Arun, M; Asha, V V

    2007-04-20

    Physalis peruviana is a medicinal herb used by Muthuvan tribes and Tamilian native who reside in the shola forest regions of Kerala, India against jaundice. It was evaluated for its antihepatotoxic, phytochemical analysis and the acute toxicity of the most promising extract in rats. Water, ethanol and hexane extracts of Physalis peruviana (500mg/kg body weight) showed antihepatotoxic activities against CCl(4) induced hepatotoxicity. The ethanol and hexane extracts showed moderate activity compared to water extract, which showed activity at a low dose of 125mg/kg. The results were judged from the serum marker enzymes. Histopathological changes induced by CCl(4) were also significantly reduced by the extract. Further, the extract administration to rats resulted in an increase in hepatic GSH and decrease in MDA. Preliminary phytochemical analysis revealed the presence of various components in the crude aqueous extract. The extract was found to be devoid of any conspicuous acute toxicity in rats. PMID:17161567

  4. Protective effect of ethyl acetate fraction of Rhododendron arboreum flowers against carbon tetrachloride-induced hepatotoxicity in experimental models

    Directory of Open Access Journals (Sweden)

    Neeraj Verma

    2011-01-01

    Result and Discussion: The substantially elevated serum enzymatic activities of SGOT, SGPT, SALP, γ-GT, and bilirubin due to CCl 4 treatment were restored toward normal in a dose-dependent manner. Meanwhile, the decreased activities of GST and glutathione reductase were also restored toward normal. In addition, ethyl acetate fraction also significantly prevented the elevation of hepatic malondialdehyde formation and depletion of reduced glutathione content in the liver of CCl 4 -intoxicated rats in a dose-dependent manner. Silymarin used as standard reference also exhibited significant hepatoprotective activity on post-treatment against CCl 4 -induced hepatotoxicity in rats. The biochemical observations were supplemented with histopathological examination of rat liver sections. The results of this study strongly indicate that ethyl acetate fraction has a potent hepatoprotective action against CCl 4 -induced hepatic damage in rats.

  5. Hepatoprotective and Antioxidant Effect of Hibiscus Polyphenol Rich Extract (HPE) Against Carbon Tetrachloride (CCL4) - Induced Damage in Rats

    OpenAIRE

    Adetutu, Adewale; Owoade, Abiodun O.

    2013-01-01

    Aims: Hibiscus sabdariffa is a medicinal plant that is consumed for its health benefits in Africa. The study was designed to investigate the hepatoprotective potentials of Hibiscus polyphenolic rich extract (HPE), (a group of phenolic compounds occurring in the dried calyx of Hibiscus sabdariffa) against CCl4-induced damaged in rats. Place and Duration of Study: Department of Biochemistry, Ladoke Akintola University of Technology, Ogbomosho, Nigeria, between January 2011 and June 2012. Method...

  6. Antioxidant and Hepatoprotective Activity of Veronica ciliata Fisch. Extracts Against Carbon Tetrachloride-Induced Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Li Yin

    2014-06-01

    Full Text Available Veronica ciliata Fisch. has been traditionally used in Traditional Chinese Medicine prescriptions due to its curative effects for hepatitis, cholecystitis, rheumatism, and urticaria. The present study was focused on investigating the role of ethyl acetate and aqueous extracts of Veronica ciliata Fisch. Furthermore, in vitro antioxidant activity (scavenging of DPPH, ABTS, superoxide, and nitrite radicals; reducing power; β-carotene bleaching and the hepatoprotective effect of the ethyl acetate extract by means of CCl4-induced oxidative stress in mice were investigated. The ethyl acetate extract of Veronica ciliata Fisch. displayed more noteworthy in vitro antioxidant activities than the aqueous extract. Moreover, it significantly prevented the increase in serum T-AOC, ALT, AST and ALP level in acute liver damage induced by CCl4, decreased the extent of MDA formation in liver and elevated the activities of SOD and GSH in liver. This activity was found to be comparable to that of bifendate. Histopathological observation of the liver was also performed to further support the evidence from the biochemical analysis. The results indicated that strong antioxidant activities and a significant protective effect against acute hepatotoxicity induced by CCl4 of Veronica ciliata Fisch. were concentrated in the ethyl acetate extract. The results suggested that this activity may be due to free radical-scavenging and antioxidant properties.

  7. Icaritin ameliorates carbon tetrachloride-induced acute liver injury mainly because of the antioxidative function through estrogen-like effects.

    Science.gov (United States)

    Liu, Peng; Jin, Xiang; Lv, Hao; Li, Jing; Xu, Wen; Qian, Hai-hua; Yin, Zhengfeng

    2014-12-01

    To investigate the effects of icaritin, an active ingredient extracted from Epimedium Sagittatum (Sieb. et Zucc.), on CCl4-induced liver injury and its possible mechanisms. Hepatocytes isolated from Sprague-Dawley male rats were treated with 3 mmol/L CCl4 for 24 h to induce acute liver cell injury, then icaritin (0.1, 1, 10, 100 μmol/L, respectively) was administrated to the cells, and estrogen receptor antagonist ICI182,780 (1 μmol/L) was co-treated with 10 μmol/L icaritin. Biochemical parameters (alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), and superoxide dismutase (SOD)) and cell apoptosis were detected to evaluate the injury degree. Protein expressions of Bax, Bcl-2, liver fatty acid-binding protein (L-FABP), and peroxisome proliferator-activated receptor-α (PPAR-α) as well as reactive oxygen species (ROS) generation were determined by western blot. Icaritin alleviated CCl4-induced liver cell injury in a concentration-dependent manner and 10 μmol/L was the optimal concentration. Icaritin (10 μmol/L) significantly reduced activities of ALT, AST in cell culture medium and MDA level of the impaired liver cells, but increased the intercellular SOD activity. The apoptotic rate of the impaired liver cells was also decreased by icaritin (10 μmol/L) treatment. Icaritin might exert antioxidative and anti-apoptotic functions via estrogen-like effect, as the ratio of Bcl-2/Bax was significantly increased, while protein expressions of L-FABP and PPAR-α were markedly increased, and this function was blocked by the estrogen receptor antagonist ICI182,780 efficiently. Icaritin may be a promising drug candidate for acute liver injury benefiting from the antioxidative and anti-apoptotic functions via estrogen-like effect. PMID:25148823

  8. Modulatory potentials of the aqueous stem bark extract of Mangifera indica on carbon tetrachloride-induced hepatotoxicity in rats

    Science.gov (United States)

    Adeneye, Adejuwon Adewale; Awodele, Olufunsho; Aiyeola, Sheriff Aboyade; Benebo, Adokiye Senibo

    2015-01-01

    Among Yoruba herbalists (Southwest Nigeria), hot water infusion of Mangifera indica L. (芒果 Máng Guǒ) stem bark is reputedly used for the treatment of fever, jaundice and liver disorders. The present study, therefore, investigates the protective effects and mechanism(s) of chemopreventive and curative effects of 125–500 mg/kg/day of Mangifera indica aqueous stem bark extract (MIASE) in acute CCl4-induced liver damage in rats. Rats were treated intragastrically with 125, 250 and 500 mg/kg/day of MIASE for 7 days before and after the administration of CCl4 (3 ml/kg of 20% CCl4, i.p.). The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), total bilirubin (TB), conjugated bilirubin (CB) and fasting blood glucose (FBG) levels were estimated. In addition, hepatic tissue reduced glutathione (GSH) and the malondialdehyde (MDA) concentrations, catalase (CAT), superoxide (SOD) activities in the hepatic homogenate, and histopathological changes in the rat liver sections were determined. Preliminary qualitative phytochemical screening for bioactive compounds in MIASE was also conducted. Results showed that oral treatment with 125–500 mg/kg/day of MIASE significantly attenuated the increase in serum ALT, AST, ALP, FBG, TB, CB and LDL-c levels in acute liver injury induced by CCl4 treatment. Findings also revealed significant elevations in the serum TC, TG, HDL-c, TP and ALB levels. There was marked architectural remodeling in the hepatic lesions of hepatocyte vacuolation and centrilobular necrosis induced by CCl4 treatment, coupled with significant weight loss. MIASE also markedly enhanced SOD and CAT activities while reducing MAD formation; and increased GSH concentration in the hepatic homogenate compared with untreated CCl4-intoxicated

  9. Modulatory potentials of the aqueous stem bark extract of Mangifera indica on carbon tetrachloride-induced hepatotoxicity in rats.

    Science.gov (United States)

    Adeneye, Adejuwon Adewale; Awodele, Olufunsho; Aiyeola, Sheriff Aboyade; Benebo, Adokiye Senibo

    2015-04-01

    Among Yoruba herbalists (Southwest Nigeria), hot water infusion of Mangifera indica L. ( Máng Guǒ) stem bark is reputedly used for the treatment of fever, jaundice and liver disorders. The present study, therefore, investigates the protective effects and mechanism(s) of chemopreventive and curative effects of 125-500 mg/kg/day of Mangifera indica aqueous stem bark extract (MIASE) in acute CCl4-induced liver damage in rats. Rats were treated intragastrically with 125, 250 and 500 mg/kg/day of MIASE for 7 days before and after the administration of CCl4 (3 ml/kg of 20% CCl4, i.p.). The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total protein (TP), albumin (ALB), triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-c), low density lipoprotein cholesterol (LDL-c), total bilirubin (TB), conjugated bilirubin (CB) and fasting blood glucose (FBG) levels were estimated. In addition, hepatic tissue reduced glutathione (GSH) and the malondialdehyde (MDA) concentrations, catalase (CAT), superoxide (SOD) activities in the hepatic homogenate, and histopathological changes in the rat liver sections were determined. Preliminary qualitative phytochemical screening for bioactive compounds in MIASE was also conducted. Results showed that oral treatment with 125-500 mg/kg/day of MIASE significantly attenuated the increase in serum ALT, AST, ALP, FBG, TB, CB and LDL-c levels in acute liver injury induced by CCl4 treatment. Findings also revealed significant elevations in the serum TC, TG, HDL-c, TP and ALB levels. There was marked architectural remodeling in the hepatic lesions of hepatocyte vacuolation and centrilobular necrosis induced by CCl4 treatment, coupled with significant weight loss. MIASE also markedly enhanced SOD and CAT activities while reducing MAD formation; and increased GSH concentration in the hepatic homogenate compared with untreated CCl4-intoxicated group

  10. Further studies on the late preventive effects of the anticalmodulin trifluoperazine on carbon tetrachloride-induced liver necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, J.; Bernacchi, A.; Fernandez, G.; Villarruel, M.C.; Ferreyra, E.; Castro, C.; Fenos, O.

    1986-03-01

    The authors previously reported that trifluorperazine (TFP) administration 6 or 10 hr after CCl/sub 4/ is able to partially prevent liver necrosis by the hepatotoxin at 24 hr. Preventive effect is not due to interference by TFP on CCl/sub 4/ metabolic activation to CCl/sub 3/ or its covalent binding to cellular components or of lipid peroxidation. Now the authors report that TFP administration 10 hr after CCl/sub 4/ does not prevent calcium accumulation but increases glycogen content. Increases in glycogen are more marked in livers of animals receiving only TFP. Administration slightly stimulates /sup 14/C-leucine incorporation in liver proteins but it does not modify decay of radioactivity in (/sup 14/C-guanidino) arginine prelabelled liver protein. TFP does not modify decay of radioactivity in /sup 32/P prelabelled phospholipid. Electron microscopy studies of livers from CCl/sub 4/ poisoned rats receiving TFP 10 hr after the hepatoto toxin and sacrificed at 24 hr revealed the presence of glycogen granules in otherwise glycogen-depleted preparations. These preparations showed only slight dilatation of the endoplasmic reticulum or the perinuclear membrane and intact mitochondria. Results might suggest that TFP interaction with calmodulin might interfere with a process of propagation of CCl/sub 4/-induced liver damage sparked by calcium accumulation and requiring the hormone for operation.

  11. Transformation of carbon tetrachloride via sulfur and oxygen substitution by Pseudomonas sp. strain KC.

    OpenAIRE

    Lewis, T A; Crawford, R L

    1995-01-01

    Pseudomonas sp. strain KC transforms carbon tetrachloride into carbon dioxide and nonvolatile products, without chloroform as an intermediate. To define the pathway for hydrolysis, nonvolatile products were analyzed. Condensation products containing the carbon atom of carbon tetrachloride as carbonyl and thioxo moieties were identified, indicating the intermediacy of phosgene and thiophosgene in the pathway.

  12. Pharmacologic application of fourier transform IR spectroscopy: in vivo toxicity of carbon tetrachloride on rat liver.

    Science.gov (United States)

    Melin, A M; Perromat, A; Déléris, G

    2000-01-01

    Microsomal fractions from rat liver were examined by means of Fourier transform IR (FTIR) spectroscopy to study the in vivo toxic effect of carbon tetrachloride administered by intraperitoneal injection. Lipid content was significantly enhanced in the liver of treated rats compared with untreated ones. The level of saturated fatty acids largely increased while that of unsaturated acids slightly decreased as a consequence of lipid peroxidation induced by the xenobiotic compound. The conformational structure of membrane proteins was changed, which was shown by the large decrease in the alpha-helical configuration. In the polysaccharide region we observed an important loss in glucidic structures that could be related to the metabolic changes caused by carbon tetrachloride intoxication. Thus, FTIR spectroscopy appears to be a useful tool to rapidly investigate the chemical alterations induced by this drug in liver microsomes and to correlate them with biochemical and physiological data.

  13. Protective effects of pomegranate (Punica granatum) juice on testes against carbon tetrachloride intoxication in rats

    OpenAIRE

    Ebtesam M Al-Olayan; El-Khadragy, Manal F.; Metwally, Dina M; Ahmed E. Abdel Moneim

    2014-01-01

    Background Pomegranate fruit has been extensively used as a natural medicine in many cultures. The present study was aimed at evaluating the protective effects of pomegranate (Punica granatum) juice against carbon tetrachloride (CCl4)-induced oxidative stress and testes injury in adult Wistar rats. Methods Twenty eight Wistar albino male rats were divided equally into 4 groups for the assessment of protective potential of pomegranate juice. Rats of group I (control) received only vehicles and...

  14. Hepatoprotective effects of Quercus infectoria gall extract against carbon tetrachloride treated liver injury in rats

    OpenAIRE

    Gaurav Lodhi; Singh, Hemant K.; PANT, KAMLESH K.; Rao, Ch V; Zeashan Hussain

    2012-01-01

    Summary. In the present study, galls of Quercus infectoria possessing potent antioxidant and antiinflammatory properties were evaluated for their hepatoprotective effect against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Subcutaneous injection of CCl4, administered twice a week, produced a marked elevation in the serum levels of aspartate transaminase (AST), alanine transaminase (ALT) and tumor necrosis factor alpha (TNF-α). Histological analysis of the liver of these rats re...

  15. Toxic effect of carbon tetrachloride on the liver of chicken

    Directory of Open Access Journals (Sweden)

    M. G. Saeed

    2009-01-01

    Full Text Available The aim of the present study was assessment of gross and microscopic pathological changes resulting from sub acute and sub chronic toxicity of carbon tetrachloride CCl4 (99.5% in the liver of chicken and its relation with serum alanine aminotransferase (ALT and aspartate aminotransferase (AST levels. The approximate lethal dose in three weeks old chickens was equal to (994 mg/kg i.p.. In the sub acute toxicity experiment the given dose was (497 mg/kg i.p. twice a week for one week, the liver of treated animals with CCl4 grossly appeared pale and mottled with white yellowish color patches represent the necrotic tissue, the histopathological changes was severe hepatitis with infiltration of inflammatory cells specially heterophiles and diffused coagulative necrosis. In sub chronic toxicity experiment the dose was given (248.5 mg/kg i.p. twice a week for eight weeks, in gross appearance the liver was severely congested, the histopathological changes was hypertrophy of hepatocytes, hyperplasia of lining epithelium of bile ducts and chronic venous congestion, growth depression and significant decreased in the body weight of the treated animals also noticed at this experiment in compared with control group, a significant increased in (ALT and (AST activities also recorded. The results suggests that pathological changes and response of the chicken’s liver to the CCl4 toxicity relatively differs from other laboratory animal models like rats and mice when used approximate dose in the same duration of exposure, so it didn’t appear fibrosis or cirrhosis of the liver of chickens, therefore it can't use chickens as a model to induce experimental fibrosis or liver cirrhosis when treated with CCl4 according to the dose and duration of exposure of this study.

  16. Fusion curves and thermodynamic properties of carbon tetrachloride, chloroform, bromoform and silicon tetrachloride at pressure up to 3500 Mpa

    Institute of Scientific and Technical Information of China (English)

    Zhu Rong-Jiao; Xu Wei; Tian Yi-Ling; Hao Ji-Shuang

    2008-01-01

    The fusion temperature as a function of pressure for carbon tetrachloride, chloroform, bromoform and silicon tetrachloride at pressures up to 3500MPa has been determined. The experimental data were fitted by the equation Tfus = T0(1 + Ap/a1)a2 exp(-a3△p) and the changes of the molar enthalpy and molar internal energy on fusion were calculated using the parameters of the fitted equation. Comparisons with the data from the literature show that the experimental data, parameters of fitted equations, changes of the molar enthalpy and molar internal energy are reliable.

  17. Review of experimental models for inducing hepatic cirrhosis by bile duct ligation and carbon tetrachloride injection Revisão de modelos experimentais de cirrose hepática induzida por ligadura do ducto biliar e por injeção de tetracloreto de carbono

    OpenAIRE

    Thamirys Guimarães Marques; Eleazar Chaib; Juliana Hamati da Fonseca; Ana Cecília Rodrigues Lourenço; Felipe Duarte Silva; Marcelo Augusto Fontenelle Ribeiro Jr; Flavio Henrique Ferreira Galvão; Luiz Augusto Carneiro D'Albuquerque

    2012-01-01

    PURPOSE: To present a review about a comparative study of bile duct ligation versus carbon tetrachloride Injection for inducing experimental liver cirrhosis. METHODS: This research was made through Medline/PubMed and SciELO web sites looking for papers on the content "induction of liver cirrhosis in rats". We have found 107 articles but only 30 were selected from 2004 to 2011. RESULTS: The most common methods used for inducing liver cirrhosis in the rat were administration of carbon tetrachlo...

  18. Tratamento homeopático da hepatotoxicose aguda induzida por tetracloreto de carbono em coelhos Homeopatic treatment of acute carbon tetrachloride induced hepatotoxicity in rabbits

    Directory of Open Access Journals (Sweden)

    Maria Cecília Ribeiro Moncorvo

    1998-09-01

    animals in group I were treated with carbon tetrachloride 30 CH, once a day. The animals in group II were treated with Phosphorus 30 CH also once a day. The rabbits in group III served as a control receiving the same quantity of placebo with the same protocol of lhe others. The blood samples were obtained by cardiac puncture every 4 days. The seric concentrations of ALT, AST, GGT and FA were submited to estatistic avaliation. The variation of all enzimes tested was significant between the days, but not always between the groups. This study demonstrated thaf carbon tetrachloride 30 CH was efficient in acelerating the recuperation of normal levels of ALT, but the terapy with Phosphorus 30 CH was insufficient for reverting the hepatic intoxication.

  19. The effect of down-regulation of Smad3 by RNAi on hepatic stellate cells and a carbon tetrachloride-induced rat model of hepatic fibrosis

    Directory of Open Access Journals (Sweden)

    Z.R. Wang

    2011-02-01

    Full Text Available Searching for effective Smad3 gene-based gene therapies for hepatic fibrosis, we constructed siRNA expression plasmids targeting the rat Smad3 gene and then delivered these plasmids into hepatic stellate cells (HSCs. The effect of siRNAs on the mRNA levels of Smad2, Smad3, Smad4, and collagens I-α1, III-α1 and IV-α1 (Colα1, Col3α1, Col4α1, respectively was determined by RT-PCR. Eighty adult male Sprague-Dawley rats were randomly divided into three groups. Twice a week for 8 weeks, the untreated hepatic fibrosis model (N = 30 and the treated group (N = 20 were injected subcutaneously with 40% (v/v carbon tetrachloride (CCl4-olive oil (3 mL/kg, and the normal control group (N = 30 was injected with olive oil (3 mL/kg. In the 4th week, the treated rats were injected subcutaneously with liposome-encapsulated plasmids (150 µg/kg into the right liver lobe under general anesthesia once every 2 weeks, and the untreated rats were injected with the same volume of buffer. At the end of the 6th and 8th weeks, liver tissue and sera were collected. Pathological changes were assessed by a semi-quantitative scoring system (SSS, and a radioimmunoassay was used to establish a serum liver fibrosis index (type III procollagen, type IV collagen, laminin, and hyaluronic acid. The mRNA expression levels of the above cited genes were reduced in the HSCs transfected with the siRNA expression plasmids. Moreover, in the treated group, fibrosis evaluated by the SSS was significantly reduced (P < 0.05 and the serum indices were greatly improved (P < 0.01. These results suggest that Smad3 siRNA expression plasmids have an anti-fibrotic effect.

  20. Potentiation of carbon tetrachloride hepatotoxicity by pentosan polysulfate in rats.

    Science.gov (United States)

    Zim, M C A; Silveira, T R; Schwartsmann, G; Cerski, T; Motta, A

    2002-11-01

    Few data are available in the literature regarding the effect of pentosan polysulfate (PPS) on normal and fibrotic rat livers. In addition, the combination of PPS and carbon tetrachloride (CCl4) has not been studied so far. The objective of this study was to assess the effect of PPS on rat livers treated or not with CCl4 for the induction of liver fibrosis. The study consisted of four stages: 1) hepatic fibrosis induction with CCl4 (N = 36 rats); 2) evaluation of the effect of PPS on CCl4-induced hepatic fibrosis (N = 36 rats); 3) evaluation of the effect of higher doses of PPS in combination with CCl4 (N = 50 rats); 4) evaluation of the presence of an enzymatic inductor effect by PPS (N = 18 rats) using the sodium pentobarbital test which indirectly evaluates hepatic microsomal enzyme activity in vivo. Adult (60 to 70 days) male Wistar rats weighing 180 to 220 g were used. All animals receiving 0.5 ml 8% CCl4 (N = 36) developed hepatic fibrosis, and after 8 weeks they also developed cirrhosis. No delay or prevention of hepatic fibrosis was observed with the administration of 5 mg/kg PPS (N = 8) and 1 mg/kg PPS (N = 8) 1 h after the administration of CCl4, but the increased hepatotoxicity resulting from the combination of the two substances caused massive hepatic necrosis in most rats (N = 45). PPS (40 mg/kg) alone caused hepatic congestion only after 8 weeks, but massive hepatic necrosis was again observed in association with 0.5 ml CCl4 after 1 to 4 weeks of treatment. Unexpectedly, sleeping time increased with time of PPS administration (1, 2, or 3 weeks). This suggests that PPS does not function as an activator of the hepatic microsomal enzymatic system. Further studies are necessary in order to clarify the unexpected increase in hepatotoxicity caused by the combination of CCl4 and high doses of PPS, which results in massive hepatic necrosis.

  1. Potentiation of carbon tetrachloride hepatotoxicity by pentosan polysulfate in rats

    Directory of Open Access Journals (Sweden)

    Zim M.C.A.

    2002-01-01

    Full Text Available Few data are available in the literature regarding the effect of pentosan polysulfate (PPS on normal and fibrotic rat livers. In addition, the combination of PPS and carbon tetrachloride (CCl4 has not been studied so far. The objective of this study was to assess the effect of PPS on rat livers treated or not with CCl4 for the induction of liver fibrosis. The study consisted of four stages: 1 hepatic fibrosis induction with CCl4 (N = 36 rats; 2 evaluation of the effect of PPS on CCl4-induced hepatic fibrosis (N = 36 rats; 3 evaluation of the effect of higher doses of PPS in combination with CCl4 (N = 50 rats; 4 evaluation of the presence of an enzymatic inductor effect by PPS (N = 18 rats using the sodium pentobarbital test which indirectly evaluates hepatic microsomal enzyme activity in vivo. Adult (60 to 70 days male Wistar rats weighing 180 to 220 g were used. All animals receiving 0.5 ml 8% CCl4 (N = 36 developed hepatic fibrosis, and after 8 weeks they also developed cirrhosis. No delay or prevention of hepatic fibrosis was observed with the administration of 5 mg/kg PPS (N = 8 and 1 mg/kg PPS (N = 8 1 h after the administration of CCl4, but the increased hepatotoxicity resulting from the combination of the two substances caused massive hepatic necrosis in most rats (N = 45. PPS (40 mg/kg alone caused hepatic congestion only after 8 weeks, but massive hepatic necrosis was again observed in association with 0.5 ml CCl4 after 1 to 4 weeks of treatment. Unexpectedly, sleeping time increased with time of PPS administration (1, 2, or 3 weeks. This suggests that PPS does not function as an activator of the hepatic microsomal enzymatic system. Further studies are necessary in order to clarify the unexpected increase in hepatotoxicity caused by the combination of CCl4 and high doses of PPS, which results in massive hepatic necrosis.

  2. 四氯化碳诱导兔肝纤维化模型的改良%Modification of liver fibrosis model of rabbit induced by carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    侯洪伟; 潘峥; 陈敏; 徐佳佳; 李卫民; 嵇振岭

    2015-01-01

    the traditional process of carbon tetrachloride ( CCl4 ) induced liver fibrosis of rabbit.Methods:50 healthy male new Zealand rabbits were included in this research and divided into 2 batches on average.Rabbits in first batch( traditional batch) were separated into 2 groups:modeling group(n=21) and control group(n=4).Rabbits in modeling group were injected with 50%CCl4 olive oil solution subcutaneously twice a week for 12 weeks in succession while control group were treated with the same amount of pure olive oil.Rabbits in modeling group received color Doppler ultrasound, spiral computed tomography and serum biochemical examination every 4 weeks from the beginning to 12 weeks, 7 rabbits ( remanent were divided equally when rabbits died unexpected ) were sacrificed after blood drawing every 4 weeks to measure portal venous pressure(PVP) and obtained liver tissues for biopsy and immunohistochemical(IHC) staining as well as staging according the ISHAK grading system; Control group were treated with the same way with modeling group and sacrificed at 12 weeks.Modify disadvantages exposed during experiment of first batch and apply revised scheme to the second batch( modified batch) .Results:Mortality of traditional patch was 42.9%and significantly higher than modified batch of 9.5%( P<0.05 ) and the success rate of traditional patch ( 57.1%) was obviously lower than that of modified batch ( 85.7%) , too.With progression of modeling process, ALT, AST, ALB, TP of modeling group underwent significant changes compare to control group ( P<0.05 ); color doppler flow imaging showed the speed of portal venous blood flow of modeling group was obviously slower and CT values were significantly reduced comparing to control group;HE, Masson and IHC staining showed explicit liver fibrosis and pseudolobule could be seen, ISHAK score rised over time(1.33 ±0.52,1.83 ±0.75,4.17 ±0.75 of modified modeling group at 4,8,12 week respectively).Conclusion:Continuous injection of CCl4 can induce

  3. Aqueous extract of Gracilaria tenuistipitata suppresses LPS-induced NF-κB and MAPK activation in RAW 264.7 and rat peritoneal macrophages and exerts hepatoprotective effects on carbon tetrachloride-treated rat.

    Science.gov (United States)

    Tseng, Chin-Kai; Lin, Chun-Kuang; Chang, Hsueh-Wei; Wu, Yu-Hsuan; Yen, Feng-Lin; Chang, Fang-Rong; Chen, Wei-Chun; Yeh, Chi-Chen; Lee, Jin-Ching

    2014-01-01

    In addition to the previous investigations of bioactivity of aqueous extract of the edible Gracilaria tenuistipitata (AEGT) against H2O2-induced DNA damage and hepatitis C virus replication, the purpose of this study is to evaluate the potential therapeutic properties of AEGT against inflammation and hepatotoxicity using lipopolysaccharide (LPS)-stimulated mouse RAW 264.7 cells, primary rat peritoneal macrophages and carbon tetrachloride (CCl4)-induced acute hepatitis model in rats. AEGT concentration-dependently inhibited the elevated RNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2, thereby reducing nitric oxide and prostaglandin E2 levels, respectively. Moreover, AEGT significantly suppressed the production of LPS-induced proinflammatory cytokines, including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α. These inhibitory effects were associated with the suppression of nuclear factor-kappa B activation and mitogen-activated protein kinase phosphorylation by AEGT in LPS-stimulated cells. In addition, we highlighted the hepatoprotective and curative effects of AEGT in a rat model of CCl4-intoxicated acute liver injury, which was evident from reduction in the elevated serum aspartate aminotransferase and alanine aminotransferase levels as well as amelioration of histological damage by pre-treatment or post-treatment of AEGT. In conclusion, the results demonstrate that AEGT may serve as a potential supplement in the prevention or amelioration of inflammatory diseases.

  4. Aqueous extract of Gracilaria tenuistipitata suppresses LPS-induced NF-κB and MAPK activation in RAW 264.7 and rat peritoneal macrophages and exerts hepatoprotective effects on carbon tetrachloride-treated rat.

    Directory of Open Access Journals (Sweden)

    Chin-Kai Tseng

    Full Text Available In addition to the previous investigations of bioactivity of aqueous extract of the edible Gracilaria tenuistipitata (AEGT against H2O2-induced DNA damage and hepatitis C virus replication, the purpose of this study is to evaluate the potential therapeutic properties of AEGT against inflammation and hepatotoxicity using lipopolysaccharide (LPS-stimulated mouse RAW 264.7 cells, primary rat peritoneal macrophages and carbon tetrachloride (CCl4-induced acute hepatitis model in rats. AEGT concentration-dependently inhibited the elevated RNA and protein levels of inducible nitric oxide synthase and cyclooxygenase-2, thereby reducing nitric oxide and prostaglandin E2 levels, respectively. Moreover, AEGT significantly suppressed the production of LPS-induced proinflammatory cytokines, including interleukin (IL-1β, IL-6 and tumor necrosis factor-α. These inhibitory effects were associated with the suppression of nuclear factor-kappa B activation and mitogen-activated protein kinase phosphorylation by AEGT in LPS-stimulated cells. In addition, we highlighted the hepatoprotective and curative effects of AEGT in a rat model of CCl4-intoxicated acute liver injury, which was evident from reduction in the elevated serum aspartate aminotransferase and alanine aminotransferase levels as well as amelioration of histological damage by pre-treatment or post-treatment of AEGT. In conclusion, the results demonstrate that AEGT may serve as a potential supplement in the prevention or amelioration of inflammatory diseases.

  5. Separation of ruthenium from nitric acid solutions using carbon tetrachloride

    International Nuclear Information System (INIS)

    The noble metal, ruthenium is one of the major fission product elements produced with high fission yield, mainly in for breeder reactors using 239Pu fuels. In the aqueous reprocessing of spent fuels for the recovery of U and Pu by PUREX process ruthenium interferes in the solvent extraction stage. In the treatment of high level liquid waste for its disposal, oxides of Ru are formed, which contaminate the surrounding environment owing to their high vapour pressure. Hence, it is desirable to separate from the waste solution prior to its processing for disposal. A simple and feasible method has been employed in the present work for the separation and recovery of ruthenium from aqueous nitric acid medium using ammonium ceric nitrate (ACN) and carbon tetrachloride (CCl4). The efficiency in the separation of Ru was investigated under various experimental conditions such as acidity and ageing effect. Separation efficiency was observed to decrease with increasing nitric acid concentration. Maximum separation was achieved at 1 M nitric acid. Further studies were carried out to investigate the effect of ageing on the separation efficiency ruthenium. With increase in time, separation percentage of ruthenium was decreasing in all concentrations of nitric acid studied. (author)

  6. The potential protective effect of Physalis peruviana L. against carbon tetrachloride-induced hepatotoxicity in rats is mediated by suppression of oxidative stress and downregulation of MMP-9 expression.

    Science.gov (United States)

    Al-Olayan, Ebtisam M; El-Khadragy, Manal F; Aref, Ahmed M; Othman, Mohamed S; Kassab, Rami B; Abdel Moneim, Ahmed E

    2014-01-01

    The active constituent profile in Cape gooseberry (Physalis peruviana L.) juice was determined by GC-MS. Quercetin and kaempferol were active components in the juice. In this study we have evaluated its potential protective effect on hepatic injury and fibrosis induced by carbon tetrachloride (CCl4). Twenty-eight rats divided into 4 groups: Group I served as control group, and Group II received weekly i.p. injection of 2 mL CCl4/kg bwt for 12 weeks. Group III were supplemented with Physalis juice via the drinking water. The animals of Group IV received Physalis juice as Group III and also were intraperitoneally injected weekly with 2 mL CCl4/kg bwt for 12 weeks. Hepatoprotective effect was evaluated by improvement in liver enzymes serum levels, reduction in collagen areas, downregulation in expression of the fibrotic marker MMP-9, reduction in the peroxidative marker malonaldehyde and the inflammatory marker nitric oxide, and restoration of the activity of antioxidant enzymatic and nonenzymatic systems, namely, glutathione content, superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, and glutathione reductase activities. The results show that the potential hepatoprotective effects of Physalis peruviana may be due to physalis acts by promotion of processes that restore hepatolobular architecture and through the inhibition of oxidative stress pathway. PMID:24876910

  7. The Potential Protective Effect of Physalis peruviana L. against Carbon Tetrachloride-Induced Hepatotoxicity in Rats Is Mediated by Suppression of Oxidative Stress and Downregulation of MMP-9 Expression

    Directory of Open Access Journals (Sweden)

    Ebtisam M. Al-Olayan

    2014-01-01

    Full Text Available The active constituent profile in Cape gooseberry (Physalis peruviana L. juice was determined by GC-MS. Quercetin and kaempferol were active components in the juice. In this study we have evaluated its potential protective effect on hepatic injury and fibrosis induced by carbon tetrachloride (CCl4. Twenty-eight rats divided into 4 groups: Group I served as control group, and Group II received weekly i.p. injection of 2 mL CCl4/kg bwt for 12 weeks. Group III were supplemented with Physalis juice via the drinking water. The animals of Group IV received Physalis juice as Group III and also were intraperitoneally injected weekly with 2 mL CCl4/kg bwt for 12 weeks. Hepatoprotective effect was evaluated by improvement in liver enzymes serum levels, reduction in collagen areas, downregulation in expression of the fibrotic marker MMP-9, reduction in the peroxidative marker malonaldehyde and the inflammatory marker nitric oxide, and restoration of the activity of antioxidant enzymatic and nonenzymatic systems, namely, glutathione content, superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase, and glutathione reductase activities. The results show that the potential hepatoprotective effects of Physalis peruviana may be due to physalis acts by promotion of processes that restore hepatolobular architecture and through the inhibition of oxidative stress pathway.

  8. Activation of phospholipase A2 by carbon tetrachloride in isolated rat hepatocytes

    International Nuclear Information System (INIS)

    Freshly isolated rat hepatocytes were incubated with 3H-arachidonic acid or 14C-ethanolamine for 1 hour in order to label cellular lipids. Thin-layer chromatographic analysis indicated that of the 3H-arachidonate incorporated into lipid nearly 50% was found in phosphatidylcholine and 15% in phosphatidylethanolamine. 14C-Ethanolamine was incorporated mainly into phosphatidylethanolamine. Hepatocytes labeled as such were exposed to carbon tetrachloride (CCl4) for periods up to 4 hours. Phospholipase A2 of these preparations was determined by measuring either the release of 4H-arachidonic acid from cellular phospholipids prelabeled with 3H-arachidonic acid or measuring the formation of 14C-lysophosphatidylethanolamine from cellular lipids prelabeled with 14C-ethanolamine. Through the use of hexane-partition extraction and thin-layer chromatographic analysis of hepatocyte lipid extracts it was found that CCl, stimulated phospholipase A2 activity in a dose- an time-dependent manner. Carbon tetrachloride at concentrations of 0.23 to 1.3 mM produced a 1.4- to 5.3-fold increase in phospholipase activity which was initiated within 30 to 60 minutes of incubation at 370. A role for phospholipase activation as a secondary mechanism of CCl4-induced hepatocyte injury is proposed

  9. Improved ACE-FTS observations of carbon tetrachloride (CCl4)

    Science.gov (United States)

    Harrison, Jeremy; Chipperfield, Martyn; Boone, Chris; Bernath, Peter

    2016-04-01

    The Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS), on board the SCISAT satellite, has been recording solar occultation spectra through the Earth's atmosphere since 2004 and continues to take measurements with only minor loss in performance. ACE-FTS time series are available for a range of chlorine 'source' gases, including CCl3F (CFC-11), CCl2F2 (CFC-12), CHF2Cl (HCFC-22), CH3Cl and CCl4. Recently there has been much community interest in carbon tetrachloride (CCl4), a substance regulated by the Montreal Protocol because it leads to the catalytic destruction of stratospheric ozone. Estimated sources and sinks of CCl4 remain inconsistent with observations of its abundance. Satellite observations of CCl4 in the stratosphere are particularly useful in validating stratospheric loss (photolysis) rates; in fact the atmospheric loss of CCl4 is essentially all due to photolysis in the stratosphere. However, the latest ACE-FTS v3.5 CCl4 retrieval is biased high by ˜ 20-30%. A new ACE-FTS retrieval scheme utilising new laboratory spectroscopic measurements of CCl4 and improved microwindow selection has recently been developed. This improves upon the v3.5 retrieval and resolves the issue of the high bias; this new scheme will form the basis for the upcoming v4 processing version of ACE-FTS data. This presentation will outline the improvements made in the retrieval, and a subset of data will be compared with modelled CCl4 distributions from SLIMCAT, a state-of-the-art three-dimensional chemical transport model. The use of ACE-FTS data to evaluate the modelled stratospheric loss rate of CCl4 will also be discussed. The evaluated model, which also includes a treatment of surface soil and ocean sinks, will then be used to quantify current uncertainties in the global budget of CCl4.

  10. Palladium-Catalyzed Addition of Carbon Monoxide and Carbon Tetrachloride to 1-Octene in Supercritical Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    张群健; 孙均华; 江焕峰; 欧阳小月; 程金生

    2003-01-01

    The Pd-catalyzed addition of carbon monoxide and carbon tetrachloride to 1-octene gave coadduct [alkyl 2-( 2, 2, 2-trichloroethyl)octanoate] as the major product in supercritical carbon dioxide by using pyridine as the base. It was found that the selectivity and the yield of coadduct were greatly affected by the pressure of carbon dioxide, the reaction temperature and the amounts of alcohol and base used.

  11. Excess enthalpies from displacement calorimetry excess enthalpies for 1,1,1- trichloroethane+carbon tetrachloride and 2-chloro-2-methylpropane+carbon tetrachloride at 298.15 K

    NARCIS (Netherlands)

    Miltenburg, J.C. van der; Obbink, J.H.; Meijer, E.L.

    1979-01-01

    Excess enthalpies HE are reported for the 1,1,1-trichloroethane+carbon tetrachloride and 2-chloro-2-methylpropane+carbon tetrachloride systems. The results are fitted to the formula HE = x(1−x)Σiai(1−2x)i.

  12. Transformation of carbon tetrachloride in an anaerobic packed-bed reactor without addition of another electron donor

    NARCIS (Netherlands)

    de Best, JH; Hunneman, P; Doddema, HJ; Janssen, DB; Harder, W; Doddema, Hans J.

    1999-01-01

    Carbon tetrachloride (52 mu M) was biodegraded for more than 72% in an anaerobic packed-bed reactor without addition of an external electron donor. The chloride mass balance demonstrated that all carbon tetrachloride transformed was completely dechlorinated. Chloroform and dichloromethane were somet

  13. Transformation of carbon tetrachloride in an anaerobic packed-bed reactor without addition of another electron donor

    NARCIS (Netherlands)

    Best, J.H. de; Hunneman, P.; Doddema, H.J.; Janssen, D.B.; Harder, W.

    1999-01-01

    Carbon tetrachloride (52 μM) was biodegraded for more than 72% in an anaerobic packed-bed reactor without addition of an external electron donor. The chloride mass balance demonstrated that all carbon tetrachloride transformed was completely dechlorinated. Chloroform and dichloromethane were sometim

  14. Comprehensive characterization of serum clinical chemistry parameters and the identification of urinary superoxide dismutase in a carbon tetrachloride-induced model of hepatic fibrosis in the female Hanover Wistar rat.

    Science.gov (United States)

    Smyth, Rosemary; Munday, Michael R; York, Malcolm J; Clarke, Christopher J; Dare, Theo; Turton, John A

    2007-10-01

    Carbon tetrachloride (CCl(4)) was used to induce liver fibrosis in the rat. Using this model, we have identified changes in serum and urinary clinical chemistry parameters, and characterized histopathological lesions in the liver. Two experiments were conducted. In Experiment 1, rats were dosed at six levels of CCl(4) (0.06-0.36 ml/kg) twice weekly for 6 weeks, followed by a 6-week non-dosing recovery period (week 12). Livers were removed for histology at 6 and 12 weeks and serum parameters analysed. In Experiment 2, rats were given seven dose levels of CCl(4) (0.4-1.0 ml/kg) twice weekly for 6 weeks, followed by a 6-week recovery period (week 12); urine samples were analysed at 3, 6, 9 and 12 weeks using one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Liver fibrosis was evident at 6 weeks in Experiments 1 and 2, and the activity of serum enzymes (including alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase) was increased. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis (Experiment 2) revealed a protein band at 18.4 kDa in urine from rats treated with CCl(4), not present in control urine, which was identified as copper/zinc superoxide dismutase (Cu/Zn SOD). Western blotting revealed that SOD was increased in urine from rats treated with CCl(4) at 3 and 6 weeks, but not at 9 and 12 weeks. We conclude that Cu/Zn SOD is a urinary marker of hepatic necrosis, but not hepatic fibrosis.

  15. Abiotic degradation rates for carbon tetrachloride and chloroform: Final report.

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Humphrys, Daniel R.; Wietsma, Thomas W.; Truex, Michael J.

    2012-12-01

    This report documents the objectives, technical approach, and progress made through FY 2012 on a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater for carbon tetrachloride (CT) and chloroform (CF). The project also sought to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. We conducted 114 hydrolysis rate experiments in sealed vessels across a temperature range of 20-93 °C for periods as long as 6 years, and used the Arrhenius equation to estimate activation energies and calculate half-lives for typical Hanford groundwater conditions (temperature of 16 °C and pH of 7.75). We calculated a half-life of 630 years for hydrolysis for CT under these conditions and found that CT hydrolysis was unaffected by contact with sterilized, oxidized minerals or Hanford sediment within the sensitivity of our experiments. In contrast to CT, hydrolysis of CF was generally slower and very sensitive to pH due to the presence of both neutral and base-catalyzed hydrolysis pathways. We calculated a half-life of 3400 years for hydrolysis of CF in homogeneous solution at 16 °C and pH 7.75. Experiments in suspensions of Hanford sediment or smectite, the dominant clay mineral in Hanford sediment, equilibrated to an initial pH of 7.2, yielded calculated half-lives of 1700 years and 190 years, respectively, at 16 °C. Experiments with three other mineral phases at the same pH (muscovite mica, albite feldspar, and kaolinite) showed no change from the homogeneous solution results (i.e., a half-life of 3400 years). The strong influence of Hanford sediment on CF hydrolysis was attributed to the presence of smectite and its ability to adsorb protons, thereby buffering the solution pH at a higher level than would otherwise occur. The project also determined liquid-vapor partition coefficients for CT under the temperatures and pressures encountered in the sealed vessels that

  16. Ameliorative effects of pomegranate on carbon tetrachloride hepatotoxicity in rats: A molecular and histopathological study.

    Science.gov (United States)

    Ibrahim, Zein Shaban; Nassan, Mohamed Abdo; Soliman, Mohamed Mohamed

    2016-04-01

    The present study aimed to investigate the molecular mechanism underlying the hepatoprotective effects of pomegranate (POM) against oxidative stress in a rat model of carbon tetrachloride (CCl4)-induced liver damage. Injection of rats with CCl4 resulted in hepatic inflammation and lipid accumulation via the upregulation of interleukin (IL)‑6 and sterol regulatory element‑binding protein 1c (SREBP‑1c) mRNA expression. CCl4 induced downregulation of the anti‑inflammatory factors alpha 2‑macroglobulin (α‑2M) and IL‑10 in comparison with the POM treated group. In addition, CCl4 induced downregulation of superoxide dismutase (SOD), glutathione S‑transferase (GST) and catalase (CAT) expression. Conversely, prior administration of POM counteracted the deleterious alterations induced by CCl4. POM downregulated CCl4-induced IL‑6 upregulation, normalized the increase in SREBP‑1c expression, and prevented CCl4‑induced α‑2M downregulation. POM counteracted CCL4‑induced alterations via immunosuppressive, anti‑inflammatory and regenerative effects by upregulating transforming growth factor‑β1, HSP70 and IL-10 mRNA expression. In addition, POM increased reactive oxygen species scavenging activity by augmenting the antioxidant defense mechanism against CCl4 hepatotoxicity, as demonstrated by detecting SOD, CAT and GST expression. These results confirm that, at the molecular level, POM exerts hepatoprotective effects against CCl4‑induced oxidative stress and liver tissue damage. PMID:26936425

  17. Quinone-respiration improves dechlorination of carbon tetrachloride by anaerobic sludge

    NARCIS (Netherlands)

    Cervantes, F.J.; Vu-Thi-Thu, L.; Lettinga, G.; Field, J.A.

    2004-01-01

    The impact of humic acids and the humic model compound, anthraquinone-2,6-disulfonate (AQDS), on the biodegradation of carbon tetrachloride (CT) by anaerobic granular sludge was studied. Addition of both humic acids and AQDS at sub-stoichiometric levels increased the first-order rate of conversion o

  18. Enrichment and purification of total flavonoids from Cortex Juglandis Mandshuricae extracts and their suppressive effect on carbon tetrachloride-induced hepatic injury in Mice.

    Science.gov (United States)

    Zhao, Pan; Qi, Chao; Wang, Gang; Dai, Xinpeng; Hou, Xiaohong

    2015-12-15

    In the present work, a simple and efficient chromatographic separation method was developed for preparative separation and enrichment of total flavonoids (TFs) from Cortex Juglandis Mandshuricae (CJM) extracts and then the protective effect of TFs against CCl4-induced acute liver injury in mice was investigated. Enrichment and purification of TFs from CJM extracts were studied using six macroporous resins and HPD-750 resin was selected as the best resin according to its adsorption and desorption properties. The operating parameters of resin column chromatography were optimized. Under the optimal conditions, TFs from CJM with purity larger than 50% were produced and their antioxidant activity was further evaluated in vitro. The mice were orally administrated with the purified TFs for seven days and then given CCl4 (0.3%, 10mL/kg i.p.). The results showed that TFs of CJM significantly attenuated the activities of serum aspartate transaminase (AST) and alanine transaminase (ALT) compared with model group, as well as the relative liver weight. Histopathological observation also revealed that TFs reduced the incidence of liver lesions and improved hepatocyte abnormality. Moreover, oral administration of TFs significantly enhanced antioxidant enzyme activities (superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px)) and decreased the content of malondialdehyde (MDA). Histopathological and biochemical results elicited that TFs of CJM had significant hepatoprotective activity comparable to the standard silymarin. This is the first time to reveal the protective actions of the TFs from CJM against CCl4-induced liver damage in mice and this natural product should be developed as a new drug for treatment of live injury in future. PMID:26562802

  19. Silicon tetrachloride plasma induced grafting for starch-based composites

    Science.gov (United States)

    Ma, Yonghui C.

    Non-modified virgin starch is seldom used directly in industrial applications. Instead, it is often physically and/or chemically modified to achieve certain enhanced properties. For many of the non-food applications, these modifications involve changing its hydrophilicity to create hydrophobic starch. In this study, the hydrophobic starch was produced through silicon tetrachloride (SiCl4) plasma induced graft polymerization, so that it could be used as a renewable and biodegradable component of, or substitute for, the petrochemical-based plastics. It was suggested that this starch graft-copolymer might be used as reinforcing components in silicone-rubber materials for starch-based composites. To make this starch graft-copolymer, the ethyl ether-extracted starch powders were surface functionalized by SiCl4 plasma using a 13.56 MHz radio frequency rotating plasma reactor and subsequently stabilized by either ethylene diamine or dichlorodimethylsilane (DCDMS). The functionalized starch was then graft-polymerized with DCDMS to form polydimethylsiloxane (PDMS) layers around the starch granules. The presence of this PDMS layer was demonstrated by electron spectroscopy for chemical analysis (ESCA/XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), gas chromatography-mass spectroscopy (GC-MS), thermo gravimetry/differential thermal analysis (TG/DTA), and other analyses. It was shown that the surface morphology, thermal properties, swelling characteristic, and hydrophilicity of starch were all changed due to the existence of this protective hydrophobic PDMS layer. Several different procedures to carry out the functionalization and graft polymerization steps were evaluated to improve the effectiveness of the reactions and to prevent the samples from being hydrolyzed by the grafting byproduct HCl. Actinometry, GC-MS, and residual gas analyzer (RGA) were used to investigate the mechanisms of the SiCl4 discharge and to optimize the plasma

  20. IFNα-2a对CCl4诱导肝纤维化的作用及影响因素%Interferon α-2a reduces carbon tetrachloride-induced hepatic fibrosis in rats

    Institute of Scientific and Technical Information of China (English)

    张伟; 易珍; 叶长根; 刘翠芸; 孙水林; 李金明; 席文娜

    2011-01-01

    目的:观察干扰素α-2a(interferon alfa-2a,IFNα-2a)对CCl4诱导肝纤维化的作用及影响因素.方法:建立CCl4诱导大鼠肝纤维化模型,SD雌性大鼠50只,分成5组,每组10只,即生理盐水对照组(A组)、纤维化模型组(B组)、6×104 U/kg IFNα-2a干预组(C组)、12×104 U/kgIFNα-2a干预组(D组)及6×104 U/kg IFNα-2a对照组(E组).造模8 wk时采集血标本及肝组织标本,分别进行肝功能指标ALT、AST、TBIL、TP,肝纤维化指标HA、LN、PCIII检测,及组织病理形态学观察包括HE染色、Masson染色和网状纤维染色.结果:CCl4腹腔注射成功诱导大鼠肝纤维化模型,表现为汇管区周围纤维化明显,有芒状纤维和纤维间隔形成.血清学检测:B、C、D组ALT、AST、TBiL、HA、LN均明显高于A组(F值分别为14.8,4.4,7.8,51.3,68.9;均P<0.05);C、D组ALT、AST、TBiL均明显低于B组;D组的上述指标又明显低于C组.组织病理:HE染色、Masson染色和网状纤维染色均显示,C、D组肝组织炎症及肝纤维化程度较B组显著减轻,D组较C组肝纤维化程度更轻,A、E组肝组织未见炎症及纤维化.结论:IFNα-2a能够阻断CC14诱导肝纤维化,其作用效果随IFNα-2a剂量增加而增强.%AIM: To observe the effect of IFNα-2a on liver fibrosis induced with carbon tetrachloride (CCL,) in rats.METHODS: Fifty female Sprague-Dawley rats were equally and randomly into five groups: groups A, B, C, D and E. Liver fibrosis was induced in rats of groups B, C and D with CCl4. Group A was treated with normal saline, while groups C, D and E were treated with 60 000, 120 000 and 60 000 U/kg IFNα-2a, respectively. At week 8, blood and liver tissue samples were collected to measure liver function (ALT, AST, TBIL, TP), evaluate liver fibrosis (HA, LN, PCIII) and pathological changes (HE staining, masson staining and reticular fiber staining).RESULTS: Hepatic fibrosis was successfully induced by CCl4 injection, and significant fibrosis around the

  1. Effect of Mallotus Philippensis Muell.-Arg leaves against hepatotoxicity of Carbon tetrachloride in rats

    Directory of Open Access Journals (Sweden)

    Ramakrishna.S,

    2011-02-01

    Full Text Available Liver Toxicity is a major health problem of worldwide proportions. Herbal medicines derived from plant extracts are being increasingly utilized to treat a wide variety of clinical diseases. In the present study MEMP leaves is used to screen the hepatoprotective activity. Hepatotoxicity was induced in experimental animals by administration of carbon tetra chloride (CCl4 (25ml/kg, i.p.. Silymarin (25 mg/kg, p.o. was used as the standard. Functional parameters like onset of sleep and duration of sleep, Biochemical Parameters like serum glutamic oxaloacetic transaminase (SGOT, serum glutamic pyruvic transaminase (SGPT, serum alkaline phosphatase (SALP, total bilirubin and direct bilirubin were measured. Cytotoxicity of CCl4 was estimated by quantitating the release of malondialdehyde (MDA. The activity of tissue antioxidant enzymes namely super oxide dismutase (SOD, catalase (CAT, and the level of total protein (TP were also measured. Histopathological evaluation of liver sections was also done. CCl4 administration in rats elevated the levels of SGPT, SGOT, SALP and bilirubin. Administration of MEMP significantly (P<0.001 prevented this increase. The activity of anti-oxidant enzymes in carbon tetrachloride (CCl4 group was decreased and these enzyme levels were significantly (p<0.001 increased in Mallotus philippensis leaves groups. Histopathological studies revealed that the concurrent administration of MEMP with CCl4 exhibited protection of liver tissue, which further evidenced the above results. Thestudy confirmed the hepatoprotective activity of MEMP, which may be attributed to its antioxidant property.

  2. The in vivo toxicity of carbon tetrachloride and carrageenan on heart microsomes: analysis by Fourier transform infrared spectroscopy.

    Science.gov (United States)

    Melin, A M; Perromat, A; Deleris, G

    2001-09-01

    We investigated the sensitivity of rat heart microsomes to free radical attack using Fourier transform infrared (FT-IR) spectroscopy. This physico-chemical method seemed a valuable technique: quite sensitive to changes in the vibrational spectra. The spectral variations observed between normal and treated rats were in great part due to reactive oxygen species that led to changes in protein conformation involving beta-sheets, aggregation of proteins, and modification of protein synthesis. Carrageenan-induced inflammation slightly enhanced the total lipid content; rearrangement of acyl chains and accumulation of cholesterol esters and phospholipids also occurred in the treated rats. Carbon tetrachloride induced a decrease in both lipid and protein contents. The level of glucidic substrates was diminished with carbon tetrachloride and enhanced with carrageenan; these changes were due to metabolic interactions between cell components and drugs. FT-IR spectroscopy provided an accurate means to monitor, in rat heart, the in vivo effects of inflammatory and peroxidative damages, to discriminate and classify the affected cells, and to correlate the findings with known physiological and biochemical data in close relationship with metabolic disruptions induced by the two xenobiotics.

  3. In vitro study of lovastatin interactions with amiodarone and with carbon tetrachloride in isolated rat hepatocytes

    Institute of Scientific and Technical Information of China (English)

    AZ Krasteva; MK Mitcheva; MS Kondeva-Burdina; VA Descatoire

    2007-01-01

    AIM: To investigate the interactions at a metabolic level between lovastatin, amiodarone and carbon tetrachloride in isolated rat hepatocytes.METHODS: For cell isolation two-step collagenase liver perfusion was performed. Lovastatin was administered alone in increasing concentrations (1 μmol/L, 3 μmol/L,5 μmol/L and 10 μmol/L) and in combination with CCl4 (86 μmol/L). The cells were also pretreated with 14 μmol/Lamiodarone and then the other two compounds were added.RESULTS: Lovastatin promoted concentration-dependent significant toxicity estimated by decrease in cell viability and GSH level by 45% and 84%, respectively. LDH-activity increased by 114% and TBARS content by 90%. CCl4 induced the expected severe damage on the examined parameters. CCl4 induced toxicity was attenuated after lovastatin pretreatment, which was expressed in less increased values of LDH activity and TBARS levels, as well as in less decreased cell viability and GSH concentrations. However, the pretreatment of hepatocytes with amiodarone abolished the protective effect of lovastatin.CONCLUSION: We suggest that the observed cytoprotective effect was due to interactions between lovastatin,CCl4 and amiodarone at a metabolic level.

  4. Summary of canister overheating incident at the Carbon Tetrachloride Expedited Response Action site

    Energy Technology Data Exchange (ETDEWEB)

    Driggers, S.A.

    1994-03-10

    The granular activated carbon (GAC)-filled canister that overheated was being used to adsorb carbon tetrachloride vapors drawn from a well near the 216-Z-9 Trench, a subsurface disposal site in the 200 West Area of the Hanford Site. The overheating incident resulted in a band of discolored paint on the exterior surface of the canister. Although there was no other known damage to equipment, no injuries to operating personnel, and no releases of hazardous materials, the incident is of concern because it was not anticipated. It also poses the possibility of release of carbon tetrachloride and other hazardous vapors if the incident were to recur. All soil vapor extraction system (VES) operations were halted until a better understanding of the cause of the incident could be determined and controls implemented to reduce the possibility of a recurrence. The focus of this report and the intent of all the activities associated with understanding the overheating incident has been to provide information that will allow safe restart of the VES operations, develop operational limits and controls to prevent recurrence of an overheating incident, and safely optimize recovery of carbon tetrachloride from the ground.

  5. Hepatoprotective effects of Quercus infectoria gall extract against carbon tetrachloride treated liver injury in rats

    Directory of Open Access Journals (Sweden)

    Gaurav Lodhi

    2012-08-01

    Full Text Available Summary. In the present study, galls of Quercus infectoria possessing potent antioxidant and antiinflammatory properties were evaluated for their hepatoprotective effect against carbon tetrachloride (CCl4 induced hepatotoxicity in rats. Subcutaneous injection of CCl4, administered twice a week, produced a marked elevation in the serum levels of aspartate transaminase (AST, alanine transaminase (ALT and tumor necrosis factor alpha (TNF-α. Histological analysis of the liver of these rats revealed marked necro-inflammatory changes that were associated with increase in the levels of TBARS, PGE2 and catalase and decrease in the levels of glutathione (GSH, superoxide dismutase (SOD and glutathione peroxidase (GPx. Daily oral administration of aqueous ethanolic extract of Quercus infectoria galls at 200, 400 and 600 mg/kg doses produced a dose dependent reduction in the serum levels of liver enzymes and inflammatory mediators and attenuated the necroinflammatory changes in the liver. The QIE treatment also normalized various biochemical parameters of oxidative stress. Our study shows that the hepatoprotective effects of QIE and silymarin were comparable and suggests that QIE could be used as a hepatoprotective agent. Industrial relevance. Research in traditional medicine has lead to the development of many modern medicines. In recent times, focus on plants research has increased all over the world and a large body of evidence has been collected to show immense potential of medicinal plants used in various traditional systems. It is very interesting to note that there is no drug available in the modern system of medicine for treating hepatic disorders; only certain herbal preparations are available to treat this quite vulnerable disease. The situation/background thus explained above warrants for developing a safe, effective and scientifically validated hepatoprotective agent taking lead from traditional medicine, which is affordable for the rural poor

  6. Efficient dechlorination of carbon tetrachloride by hydrophobic green rust intercalated with dodecanoate anions

    DEFF Research Database (Denmark)

    Ayala Luis, Karina Barbara; Ginette Anneliese Cooper, Nicola; Bender Koch, Christian;

    2012-01-01

    The reductive dechlorination of carbon tetrachloride (CT) by Fe-II-Fe-III hydroxide (green rust) intercalated with dodecanoate, (Fe4Fe2III)-Fe-II (OH)(12)(C12H23O2)(2)center dot gamma H2O (designated GR(C12)), at pH similar to 8 and at room temperature was investigated. CT at concentration levels...

  7. In situ bioremediation for the Hanford carbon tetrachloride plume. Innovative technology summary report

    International Nuclear Information System (INIS)

    The 200 Area at Hanford (also called the Central Plateau) contains approximately 817 waste sites, 44 facilities to be demolished, and billions of gallons of contaminated groundwater resulting from chemical processing plants and associated waste facilities (e.g., waste tanks). From 1955 to 1973, carbon tetrachloride, nitrate, and other materials were discharged to subsurface liquid waste disposal facilities in the 200 Area. As much as 600,000 kilograms of carbon tetrachloride may have entered the soil column and a portion of this has contaminated the underlying aquifer. In Situ Bioremediation for the Hanford Carbon Tetrachloride Plume (ISB), which is the term used in this report for an in situ treatment process using indigenous micro-organisms with a computer based Accelerated Bioremediation Design Tool (ABDT), remediates groundwater contaminated with volatile organic compounds (VOCs) and nitrates under anaerobic conditions. ISB involves the injection of nutrients into the groundwater and subsequent extraction and re-injection of the groundwater to provide nutrient distribution in the aquifer

  8. Hepatoprotective potential of three sargassum species from Karachi coast against carbon tetrachloride and acetaminophen intoxication

    Directory of Open Access Journals (Sweden)

    Khan Hira

    2016-01-01

    Full Text Available Objective: To assess the hepatoprotective effect of ethanol extracts of Sargassum variegatum (S. variegatum, Sargassum tenerrimum (S. tenerrimum and Sargassum binderi occurring at Karachi coast against carbon tetrachloride (CCl4 and acetaminophen intoxication in rats. Methods: Sargassum species were collected at low tide from Buleji beach at Karachi coast. Effect of ethanol extracts of Sargassum spp., on lipid parameter, serum glucose and kidney function was examined. Liver damage in rats was induced by CCl4 or acetaminophen. Rats were administered with ethanol extracts of S. tenerrimum, S. variegatum and Sargassum binderi at 200 mg/kg body weight daily for 14 days separately. Hepatotoxicity was determined in terms of cardiac and liver enzymes and other biochemical parameters. Results: S. variegatum showed highest activity by reducing the elevated level of hepatic enzymes, bilirubin, serum glucose, triglyceride with restoration of cholesterol. Urea and creatinine concentrations were also significantly (P < 0.05 reduced as compared to acetaminophen intoxicated rats. S. tenerrimum and S. variegatum showed moderate activity against CCl4 hepatic toxicity. Conclusions: The protective role of S. variegatum against acetaminophen liver damage and its positive impact on disturbed lipid, glucose metabolism, kidney dysfunction and S. tenerrimum against CCl4 liver toxicity suggest that Sargassum species offer a non-chemical means for the treatment of toxicity mediated liver damage.

  9. Hepatoprotective potential of threesargassum species from Karachi coast against carbon tetrachloride and acetaminophen intoxication

    Institute of Scientific and Technical Information of China (English)

    Khan Hira; Viqar Sultana; Jehan Ara; Syed Ehteshamul-Haque; Mohammad Athar

    2016-01-01

    Objective:To assess the hepatoprotective effect of ethanol extracts ofSargassum variegatum (S. variegatum),Sargassum tenerrimum (S. tenerrimum) andSargassum binderi occurring at Karachi coast against carbon tetrachloride (CCl4) and acetaminophen intoxication in rats. Methods:Sargassum species were collected at low tide from Buleji beach at Karachi coast. Effect of ethanol extracts ofSargassum spp., on lipid parameter, serum glucose and kidney function was examined. Liver damage in rats was induced by CCl4 or acetaminophen. Rats were administered with ethanol extracts ofS. tenerrimum,S. variegatum andSargassum binderi at 200 mg/kg body weight daily for 14 days separately. Hepatotoxicity was determined in terms of cardiac and liver enzymes and other biochemical parameters. Results:S. variegatum showed highest activity by reducing the elevated level of hepatic enzymes, bilirubin, serum glucose, triglyceride with restoration of cholesterol. Urea and creatinine concentrations were also significantly (P < 0.05) reduced as compared to acetaminophen intoxicated rats.S. tenerrimum andS. variegatum showed moderate activity against CCl4 hepatic toxicity. Conclusions: The protective role ofS. variegatum against acetaminophen liver damage and its positive impact on disturbed lipid, glucose metabolism, kidney dysfunction andS. tenerrimum against CCl4 liver toxicity suggest thatSargassum species offer a non-chemical means for the treatment of toxicity mediated liver damage.

  10. Protective effects of luteolin-7-glucoside against liver injury caused by carbon tetrachloride in rats.

    Science.gov (United States)

    Qiusheng, Zheng; Xiling, Sun; Xubo; Meng, Song; Changhai, Wang

    2004-04-01

    Ixeris chinensis (Thunb.) Nakai has been used as a Chinese folk medicine; the information on the physiological and biochemical functions of the compounds extracted from I. chinensis is still scanty. We investigated the effects of luteolin -7-glucoside (LUTG) isolated from I. chinensis against liver injury caused by carbon tetrachloride (CCl4). CCl4 significantly increased the enzyme activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) in blood serum, as well as the level of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in liver tissue, and decreased the levels of reduced glutathione (GSH). Pretreatment with LUTG was not only able to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also reduce the damage of hepatocytes in vitro. On the other hand, we also found LUTG has strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. The hepatoprotective activity of LUTG was possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that LUTG had protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of LUTG may help in the development of a clinical application. PMID:15125574

  11. Therapeutic effect of arctigenin on carbon tetrachloride-induced liver fibrosis in rats%牛蒡子苷元对四氯化碳致大鼠肝纤维化的治疗作用

    Institute of Scientific and Technical Information of China (English)

    张晓珣; 王俊; 赵宇; 张景耀; 李傲

    2016-01-01

    目的:研究牛蒡子苷元(ATG)对四氯化碳(CCl4)诱导的大鼠肝纤维化的防治作用及可能的作用机制。方法成年Sprague-Dawley大鼠随机分为溶剂对照组、ATG 3.0 mg·kg-1、CCl4模型组、CCl4+ATG 1.0和3.0 mg·kg-1组和CCl4+秋水仙碱(COL)0.1 mg·kg-1阳性对照组,采用sc的方法复制大鼠CCl4肝纤维化模型,造模8周。从第5周开始,ig给予ATG和COL,连续治疗4周。测定各组大鼠血清中谷丙转氨酶(GPT)、谷草转氨酶(GOT)的活性以及白蛋白(ALB)、总胆红素(TBIL)的水平,肝组织中羟脯氨酸(HYP)的含量;HE和Masson染色观察肝组织病理改变,并采用组织免疫荧光法检测活化的肝星状细胞增殖,Western蛋白质印迹法检测细胞周期相关蛋白的表达。结果与CCl4模型组比较,ATG 1.0和3.0 mg·kg-1可显著升高纤维化大鼠血清中ALB含量(P<0.05),降低血清中GPT,AST和TBIL水平(P<0.05),从而降低肝损伤的程度;ATG 1.0和3.0 mg·kg-1还能显著降低纤维化大鼠肝组织中HYP的含量(P<0.05),减少肝内纤维组织的形成。同时,ATG 1.0和3.0 mg·kg-1还能抑制纤维化大鼠肝组织中活化的HSC增殖,显著降低细胞周期相关调控蛋白细胞周期蛋白D1(cyclin D1)、细胞周期蛋白依赖性蛋白激酶(CDK)2和4及增殖细胞核抗原的表达(P<0.05),同时上调细胞周期阻抑物蛋白p27kip1的表达水平(P<0.05)。结论 ATG对CCl4诱导的大鼠肝损伤和肝纤维化具有显著的治疗作用,其作用机制可能与抑制活化的HSC增殖相关。%OBJECTIVE To investigate the effect of arctigenin(ATG) on liver fibrosis in rats induced by carbon tetrachloride(CCl4)and to explore its underlying mechanism. METHODS Sprague-Dawley rats were randomly divided into six groups:vehicle,ATG 3.0 mg · kg-1 group,CCl4 model group,CCl4+ATG 1.0 and 3.0 mg·kg-1 groups,and CCl4+colchicine(COL)0.1 mg·kg-1

  12. Carbon tetrachloride/carbon disulfide exposures in grain fumigation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Marano, D.E.; White, K.L.; Deer, H.; Alexander, G.

    1986-03-01

    The use of 80/20 compounds as liquid-fumigant mixtures in the grain-handling industry was considered. Worker exposures to carbon tetrachloride and carbon disulfide were measured at representative facilities throughout the industry. Work practices that may contribute to high exposure levels were cited. Approximately equal amounts of liquid fumigants and solid formulations of phosphine are used throughout the industry. As spraying is done on a sporadic basis, it does not appear likely to present a major problem such as might be encountered in continuous exposure situations. The authors conclude that grain workers do not appear to be an ideal study group for a neurotoxicity morbidity study due to the fact that the physical distance between study sites and the small number of workers at each site makes it difficult logistically. A concerted effort throughout the grain industry to educate those workers in the grain-handling portions of that industry toward the safe handling of fumigants should go far in alleviating any problems arising from exposure to fumigants.

  13. Transformation of carbon tetrachloride by Pseudomonas sp. strain KC under denitrification conditions

    International Nuclear Information System (INIS)

    A denitrifying Pseudomonas sp. (strain KC) capable of transforming carbon tetrachloride (CT) was isolated from groundwater aquifer solids. Major products of the transformation of 14C-labeled CT by Pseudomonas strain KC under denitrification conditions were 14CO2 and an unidentified water-soluble fraction. Little or no chloroform was produced. Addition of dissolved trace metals, notably, ferrous iron and cobalt, to the growth medium appeared to enhance growth of Pseudomonas strain KC while inhibiting transformation of CT. It is hypothesized that transformation of CT by this organism is associated with the mechanism of trace-metal scavenging

  14. Adsorption of alkenyl succinic anhydride from solutions in carbon tetrachloride on a fine magnetite surface

    Science.gov (United States)

    Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

    2016-06-01

    The adsorption of alkenyl succinic anhydride from a solution in carbon tetrachloride on a fine magnetite surface at a temperature of 298.15 K is studied using fine magnetite, which forms the basis of magnetic fluids, as the adsorbent. An adsorption isotherm is recorded and interpreted in terms of the theory of the volume filling of micropores (TVFM). Adsorption process parameters are calculated on the basis of the isotherm. It is shown that at low equilibrium concentrations, the experimental adsorption isotherm is linear in the TVFM equation coordinates.

  15. Spectral luminescence and photochemical properties of chlorophyll a in solution containing carbon tetrachloride

    International Nuclear Information System (INIS)

    Studies were conducted on photophysical and photochemical processes in chlorophyll a in carbon tetrachloride and ether by means of flash photolysis, electron spin resonance, and fluorescence spectroscopy. Lifetimes and quenching of triplet states were analyzed and absorption spectra and fluorescence decay times are given. The kinetics of triplet-triplet absorption and hyperfine structure were determined. An absolute quantum yield of the photochemical reaction was measured within the range of linear dependence of the optical density on the time of chlorophyll a irradiation by a krypton laser and the excitation wavelength of 647.1 nm

  16. Therapeutic detoxification of quercetin against carbon tetrachloride-induced acute liver injury in mice and its mechanism%槲皮素对四氯化碳引起的小鼠急性肝损伤治疗作用及其机理

    Institute of Scientific and Technical Information of China (English)

    Jia-qi ZHANG; Liang SHI; Xi-ning XU; Si-chong HUANG; Bin LU; Li-li JI; Zheng-tao WANG

    2014-01-01

    This study observes the therapeutic detoxification of quercetin, a wel-known flavonoid, against carbon tetrachloride (CCl4) induced acute liver injuryin vivo and explores its mechanism. Quercetin decreased CCl4-increased serum activities of alanine and aspartate aminotransferases (ALT/AST) when orally taken 30 min after CCl4 intoxica-tion. The results of a histological evaluation further evidenced the ability of quercetin to protect against CCl4-induced liver injury. Quercetin decreased the CCl4-increased malondialdehyde (MDA) and reduced the glutathione (GSH) amounts in the liver. It also reduced the enhanced immunohistochemical staining of the 4-hydroxynonenal (4-HNE) in the liver induced by CCl4. Peroxiredoxin (Prx) 1, 2, 3, 5, 6, thioredoxin reductase 1 and 2 (TrxR1/2), thioredoxin 1 and 2 (Trx1/2), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) al play critical roles in maintaining celular redox homeostasis. Real-time polymerase chain reaction (PCR) results demonstrated that quercetin reversed the decreased mRNA expression of al those genes induced by CCl4. In conclusion, our results demonstrate that quercetin ameliorates CCl4-induced acute liver injuryin vivo via aleviating oxidative stress injuries when oraly taken after CCl4 intoxication. This protection may be caused by the elevation of the antioxidant capacity induced by quercetin.

  17. Effectiveness of enterosgel usage in the conditions of simultaneous destruction of rats by karbofos and carbon tetrachloride

    OpenAIRE

    L. А. Boyko; L. S. Fira; P. G. Lychatskiy

    2014-01-01

    The aim of our study was to examine the effectiveness of the enterosgel sorbent in the terms of simultaneous destruction of rats by karbofos and carbon tetrachloride. Experiments were carried out on white rats weighing 175–200 g, which were kept on a standard diet. Karbofos was administered intragastrically on daily basis in the aqueous solution at the rate of 20 mg/kg of the body weight, which is 1/10 of the LD50. Carbon tetrachloride was administered intraperitoneally, twice a day in the fo...

  18. Influence of Phenobarbital and Carbon tetrachloride on the Modulation of Tissue Retention Profile of Hexachlorocyclohexane in Rats

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The study was designed to investigate the role of hepatic metabolic activity on body burden of HCH residue. Male albino rats were orally administered 0, 5, and 10 mg/kg HCH for 90 days, followed by either sodium phenobarbital or carbon tetrachloride treatment for 0, 15 and 30 days after withdrawal of their respective HCH administration. The liver weight was significantly increased at 30 days after the administration of phenobarbital and carbon tetrachloride in both 5 mg and 10 mg/kg HCH withdrawal groups when compared to control. HCH residue was maximun in fat followed by adrenal>thymus>liver>kidney>spleen>testes>brain>plasma. Carbon tetrachloride caused an accumul-ation of HCH residues in the liver 15 and 30 days after administration of both doses of HCH. Phenobarbital did not show significant variation in HCH residues in hepatic tissue. Phenobarbital treatment caused significant induction of hepatic RED, APD, AHH, GST and QR activities. Significant decreases in activities were observed by carbon tetrachloride when compared to animals treated with HCH alone. The overall results clearly suggest the role of P450 protein on the body burden of HCH residues.

  19. Antihepatotoxic effect of golden berry (Physalis peruviana Linn.) in carbon tetrachloride (CCl4) intoxicated rats.

    Science.gov (United States)

    Taj, Darakhshan; Khan, Hira; Sultana, Viqar; Ara, Jehan; Ehteshamul-Haque, Syed

    2014-05-01

    Liver is the main site in the body for intense metabolism and excretion. A number of chemicals and drugs which are used routinely cause liver damage. The present study investigates the antihepatotoxic effect of Physalis peruviana whole ripe fruit, water and ethanol extracts of fruit in normal as well as in carbon tetrachloride (CCl(4)) intoxicated rats. The CCl(4) treated rats showed marked elevation in liver enzymes: alanine transaminse, aspratate transaminase, alkaline phosphatase, lactate dehydrogenase and other biochemical parameters: bilirubin, creatinine and urea, thus indicating liver injury. Whereas animal treated/fed with various preparations of Physalis peruviana showed significant lowering effect (pPhysalis peruviana showed highest activity in both rat models while ripe fruit and ethanol extract showed moderate activity compared to standard drug. PMID:24811807

  20. Efficiency of ethylene dichloride and carbon tetrachloride mixture for fumigation of important animal feeds

    Directory of Open Access Journals (Sweden)

    H. G. Khalsa

    1964-01-01

    Full Text Available It has been found that animal feeds like crushed barley, crushed gram and wheat bran can be effectively disinfested by fumigation with 3:1 mixture of ethylene dichloride and carbon tetrachloride at a dosage of 2.5 gallons per 1,000 cuft. The lowest average atmospheric temperatures, at which the fumigation for 48 hours and for 72 hours was found effective, were 28.6 and 24.15 degree celcius respectively. It was also found that the order of susceptibility of the three test insects, viz. Tribolium castaneum Herbst, Trogoderma granerium Everts and Latheticus oryzae Watrh and their various stages varied considerably. in all cases, adults and pupae were found to be more susceptible than larvae.

  1. A combination of Ang Ⅱ and carbon tetrachloride accelerates process of hepatic fibrosis

    Institute of Scientific and Technical Information of China (English)

    周馨; 李定国; 李宣海; 陆汉明; 张文竹

    2003-01-01

    Objective To assess whether Angiotensin Ⅱ (Ang Ⅱ) and carbon tetrachloride (CCl4) used in combination could accelerate the process of fibrosis and whether Ang Ⅱ play a role in exaggerating hepatic fibrosis in rats.Methods Ang Ⅱ was injected into the abdominal cavity of Sprague-Dawley (SD) rats together with subcutaneous injection of CCl4. Rats were killed after 14 and 28 d. Blood serum and liver specimen were collected. The extent of fibrosis in the stained liver tissue sections was determined with the KS 400 Image Analysis System. Results Rats receiving Ang Ⅱ and CCl4 for 28 d showed extensive liver fibrosis. Along with the increase of hepatic fibrosis, the serum concentration of Ang Ⅱ went up gradually. Conclusions A combination of Ang Ⅱ and CCl4 would accelerate the process of hepatic fibrosis. Ang Ⅱ probably took part in the occurrence of heparic fibrosis.

  2. Protective Effects of Dimethyl—4,4‘—Dinmethoxy—5,6,5’,6‘—Dimethylene Dioxybiphenyl—2,2’—Dicarboxylate on Damages of Isolated Rat Hepatocytes Induced by Carbon Tetrachloride and D—galactosam

    Institute of Scientific and Technical Information of China (English)

    FUTIEBO; LIUGENGTAO

    1992-01-01

    The rotective effect of biphenyl dimethyl dicarboxylate(DDB)on chemically induced damages was studied in isolated suspended rat hepatocytes.The experimental results showed that DDB(200μg/106cells) efficiently protected the hepatocytes against carbon tetrachloride(CCl4 10mmol·L-1)and D-galactosamine(1mmol·L1)induce damages.Membranal lipid peroxidation(malondialdehyde,MDA formation(and glutamic pyruvic transaminase(GPT) release from the hepatocytes were markedly decreased.The damage of the cell surfaces of the hepatocytes were also reduced as seen under a scanning electrom microscope(SEM). Pretreatment with DDB(300mg·kg-1)orally ameliorated the reduction of liver glycogen and blood glucose caused by ip injection of D-galactosamine(800mg·kg-1)in mice.When normal rats were given DDB 300mg·kg-1 once daily for 10d,the free ribosomal protein and RNA in the liver increased significantly.These results indicate that DDB is of beneficial effects on both damaged and normal hepatocytes.

  3. HEPATOPROTECTIVE ACTIVITY OF EXTRACTS FROM STEM OF MUSSAENDA ERYTHROPHYLLA LAM. AGAINST CARBON TETRACHLORIDE – INDUECD TOXICITY IN RATS

    Directory of Open Access Journals (Sweden)

    CHINNA ESWARAIAH, SATYANARAYANA

    2013-09-01

    Full Text Available Mussaenda erythrophylla (Rubiaceae is native to western tropical Africa, occasionally seen in gardens and parks as ornamental plant in India. The Hepatoprotective activity of ethyl acetate and methanol extracts of M.erythrophylla (ME Stem against carbon tetrachloride (CCl4 induced liver damage in Wistar albino rats. Ethyl acetate and methanolic extracts of ME (100,200mg/kg.p.o., were administerd respectively, Silymarin (25 mg/kg.p.o. was given as reference standard. The stem extracts were effective in protectingthe liver against the injury induced by CCl4 in animals. This was evident from significant reduction in serum enzyme, SGOT, SGPT, ALP and Total bilirubin (TB.Various pathological changes like centribular necrosis and vacuolization were observed in CCL4 treated rats, which were significant protective activity in groups treated with ME and silymarin. It was concluded from the study that ethyl acetate and methanolic extracts of ME possess hepatoprotective activity against CCl4 induced hepatotoxicity in rats.

  4. Reaction of carbon tetrachloride with methane in a non-equilibrium plasma at atmospheric pressure, and characterisation of the polymer thus formed.

    Science.gov (United States)

    Gaikwad, Vaibhav; Kennedy, Eric; Mackie, John; Holdsworth, Clovia; Molloy, Scott; Kundu, Sazal; Stockenhuber, Michael; Dlugogorski, Bogdan

    2014-09-15

    In this paper we focus on the development of a methodology for treatment of carbon tetrachloride utilising a non-equilibrium plasma operating at atmospheric pressure, which is not singularly aimed at destroying carbon tetrachloride but rather at converting it to a non-hazardous, potentially valuable commodity. This method encompasses the reaction of carbon tetrachloride and methane, with argon as a carrier gas, in a quartz dielectric barrier discharge reactor. The reaction is performed under non-oxidative conditions. Possible pathways for formation of major products based on experimental results and supported by quantum chemical calculations are outlined in the paper. We elucidate important parameters such as carbon tetrachloride conversion, product distribution, mass balance and characterise the chlorinated polymer formed in the process.

  5. D-Dopachrome tautomerase is a candidate for key proteins to protect the rat liver damaged by carbon tetrachloride

    International Nuclear Information System (INIS)

    Carbon tetrachloride (CCl4) is known to induce liver damage. Animal experiments with CCl4 injections have revealed many findings, especially mechanisms of liver damage and liver regeneration. Recently, proteomic approaches have been introduced in various studies to evaluate the quantitative and qualitative changes in the comprehensive proteome level. The aim of this research is to elucidate the key protein for liver damage, liver protection and liver regeneration by using proteomic techniques. 50 % (v/v) CCl4 in corn oil was administered intraperitoneally to adult male rats at a dose of 4 ml/kg body weight. Approximately 24 h after the injection, the liver was removed and extracted proteins were analyzed with cleavable isotope coded affinity tag (cICAT) reagents, two-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS). A twelvefold increase in D-dopachrome tautomerase (DDT) was indicated. This enzyme has been reported to be involved in the biosynthesis of melanin, an antioxidant. According to the histological analysis, melanin levels were increased in un-damaged hepatocytes of CCl4-treated rats. These results suggest that the increase in DDT is a response to liver damage, accelerates melanin biosynthesis and protects the liver from oxidative stress induced by CCl4

  6. Antioxidant Activity of Extract and Its Major Constituents from Okra Seed on Rat Hepatocytes Injured by Carbon Tetrachloride

    Directory of Open Access Journals (Sweden)

    Lianmei Hu

    2014-01-01

    Full Text Available The antioxidant activities and protective effects of total phenolic extracts (TPE and their major components from okra seeds on oxidative stress induced by carbon tetrachloride (CCl4 in rat hepatocyte cell line were investigated. The major phenolic compounds were identified as quercetin 3-O-glucosyl (1→6 glucoside (QDG and quercetin 3-O-glucoside (QG. TPE, QG, and QDG from okra seeds exhibited excellent reducing power and free radical scavenging capabilities including α, α-diphenyl-β-picrylhydrazyl (DPPH, superoxide anions, and hydroxyl radical. Overall, DPPH radical scavenging activity and reducing power of QG and QDG were higher than those of TPE while superoxide and hydroxyl radical scavenging activities of QG and TPE were higher than those of QDG. Furthermore, TPE, QG, and QDG pretreatments significantly alleviated the cytotoxicity of CCl4 on rat hepatocytes, with attenuated lipid peroxidation, increased SOD and CAT activities, and decreased GPT and GOT activities. The protective effects of TPE and QG on rat hepatocytes were stronger than those of QDG. However, the cytotoxicity of CCl4 on rat hepatocytes was not affected by TPE, QG, and QDG posttreatments. It was suggested that the protective effects of TPE, QG, and QDG on rat hepatocyte against oxidative stress were related to the direct antioxidant capabilities and the induced antioxidant enzymes activities.

  7. Reductive Dechlorination of Carbon Tetrachloride by Tetrachloroethene and Trichloroethene Respiring Anaerobic Mixed Cultures

    Science.gov (United States)

    Vickstrom, K. E.; Azizian, M.; Semprini, L.

    2015-12-01

    Carbon tetrachloride (CT) is a toxic and recalcitrant groundwater contaminant with the potential to form a broad range of transformation products. Of the possible biochemical pathways through which CT can be degraded, reductive dehalogenation to less chlorinated compounds and mineralization to carbon dioxide (CO2) appear to be the most frequently utilized pathways by anaerobic organisms. Results will be presented from batch experiments of CT degradation by the Evanite (EV), Victoria Strain (VS) and Point Mugu (PM) anaerobic dechlorinating cultures. The cultures are grown in chemostats and are capable of transforming tetrachloroethene (PCE) or trichloroethene (TCE) to ethene by halorespiration via reductive dehalogenase enzymes. For the batch CT transformation tests, the cells along with supernatant were harvested from chemostats fed PCE or TCE, but never CT. The batch reactors were initially fed 0.0085 mM CT and an excess of formate (EV and VS) or lactate (PM) as electron donor. Transformation of CT was 100% with about 20% converted to chloroform (CF) and undetected products. Multiple additions of CT showed a slowing of pseudo first-order CT transformation rates across all cultures. Batch reactors were then established and fed 0.085 mM CT with an excess of electron donor in order to better quantify the reductive pathway. CT was transformed to CF and dichloromethane (DCM), with trace amounts of chloromethane (CM) detected. Between 60-90% of the mass added to the system was accounted for, showing that the majority of the carbon tetrachloride present is being reductively dehalogenated. Results from batch reactors that were poisoned using sodium azide, and from reactors not provided electron donor will be presented to distinguish between biotic and abiotic reactions. Furthermore, results from reactors prepared with acetylene (a potent, reversible inhibitor of reductive dehalogenases (1)) will be presented as a means of identifying the enzymes involved in the

  8. Gas Phase Conversion of Carbon Tetrachloride to Alkyl Chlorides Catalyzed by Supported Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    SUN Aijun; ZHANG Jinlong; LI Chunxi; MENG Hong

    2009-01-01

    An efficient way of converting carbon tetrachloride(CTC)to alkyl chlorides is reported,which uses the catalysts of ionic liquids supported on granular active carbon.The catalytic performance was evaluated in a temperature range of 120-200℃ and atmospheric pressure for different ionic liquids,namely 1-butyl-3-methylimidazolium chloride,1-octyl-3-methylimidazolium chloride,hydrochloric salts of N-methylimidazole(MIm),pyridine and triethylamine,as well as bisulfate and dihydric phosphate of N-methylimidazole.On this basis,the reaction mechanism was proposed,and the influences of the reaction temperature and the attributes of ionic liquids were discussed.The overall reaction was assumed to be comprised of two steps,the hydrolysis of CTC and reaction of HCI with alcohols under acidic catalyst.The results indicate that the conversion of CTC increased monotonically with temperature and even approached 100% at 200 ℃,while the maximum selectivity to alkyl chlorides was obtained around 160 ℃.This reaction might be potentially applicable to the resource utilization of superfluous byproduct of CTC in the chloromethane industry.

  9. Cost/benefit analysis comparing ex situ treatment technologies for removing carbon tetrachloride from Hanford groundwater

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory conducted a cost/benefit and performance analysis to compare ex situ technologies that can be used to destroy the carbon tetrachloride (CCl4) in the ground water of Hanford's 200 West Area. The objective of this work was to provide a direct quantitative and qualitative comparison of competing technologies. The technologies examined included a biological system, the Thermochemical Environmental Energy System II (TEES II), and a UV/oxidation system. The factors examined included key system operation parameters, impact on inorganic contaminants in the ground water, and secondary waste production. The cost effectiveness of these destruction technologies was also compared to the cost for an air stripping/granular activated carbon (AS/GAC) system. While the AS/GAC system appeared to be more cost effective at many levels than the CCl4 destruction technologies, the secondary waste produced by this system may lead to significant cost and/or regulatory problems. The factors with the greatest influence on cost for each destruction technology are as follows: nutrient requirements for both of the biological systems, electricity requirements and the type of unit operations for the TEES II process, and electricity requirements for UV/oxidation

  10. Colchicine antimitosis abolishes resiliency of postnatally developing rats to chlordecone-amplified carbon tetrachloride hepatotoxicity and lethality.

    OpenAIRE

    Dalu, A; Rao, P S; Mehendale, H M

    1998-01-01

    We have previously reported that rats are resilient to the hepatotoxic and lethal combination of chlordecone (CD) and carbon tetrachloride (CCl4) during early postnatal development. The overall findings pointed to stimulated cell division and tissue repair mechanisms as the underlying cause of resistance. The objective of the current study was to investigate if the antimitotic effect of colchicine (CLC) abolishes this resiliency to CD + CCl4 by inhibiting ongoing and stimulated cell division....

  11. Investigation on preparation of uranium tetrachloride from chlorinating uranium dioxide by carbon tetrachloride and its mixing reagents

    International Nuclear Information System (INIS)

    By studying the change of the temperature for gaseous space and solid layer within the reactor and improving structure of reactor and types of feed material stocked in the boat pan, it is possible to reduce the volatilization loss of uranium, allowing the uranium yield to rise above 97%. A further study found that chlorination of UO2 by using a mixture of CHCl3 + CCl4 can markedly reduce the volatilization loss of uranium chlorides, and the uranium yield is above 99%. The content of free carbon is less than 100 ppm in the product. A new chlorination process has been developed

  12. Apoptosis initiated by carbon tetrachloride in mitochondria of rat primary cultured hepatocytes

    Institute of Scientific and Technical Information of China (English)

    Yan CAI; Li-kun GONG; Xin-ming QI; Xiang-hong LI; Jin REN

    2005-01-01

    Aim: To investigate the mitochondria-initiated apoptosis pathway involved in Carbon tetrachloride (CCl4) hepatotoxicity in vitro. Methods: Several cytotoxicity endpoints, including WST-8 metabolism, lactate dehydrogenase leakage and morphological changes, were examined. The 5,5'-dithio-bis(2-nitrobenzoic acid)reaction was used to measure reduced glutathione level, and the malondialdehyde level was determined using the thiobarbituric acid assay. The release of cytochrome c and Bcl-XL was detected by Western blot. Caspase-3 activity was measured using the fiuorogenic substrate Ac-DEVD-AMC. DNA fragmentation was used to evaluate cell apoptosis. Results: A time- and dose-dependent decrease in cellular glutathione content was observed, along with a concomitant increase in malondialdehyde levels following the application of CC14. Caspase 3 activity was stimulated at all doses of CCl4, with the most significant activation at 3 mmol/L.Cytochrome c was released obviously after CC14 treatment. A time-dependent decrease in Bcl-XL expression was observed. DNA fragmentation results revealed apoptosis and necrosis following CC14 treatment. Conclusion: Oxidative damage is one of the essential mechanisms of CC14 hepatotoxicity, which triggers apoptosis via the mitochondria-initiated pathway.

  13. Molecular Interaction Studies of Benzyl Alcohols with Methacrylates in Carbon Tetrachloride using Frequency Domain Technique

    Directory of Open Access Journals (Sweden)

    S. Radhakrishnan

    2016-08-01

    Full Text Available The dielectric relaxation of benzyl alcohol substitutents (benzyl alcohol, m-methylbenzyl alcohol and m-nitrobenzyl alcohol with methyl methacrylate and butyl methacrylate in dilute solution of carbon tetrachloride is measured at 9.37 GHz using Frequency domain (X-band technique. Different dielectric parameters like dielectric constant (ε׳, dielectric loss factor (ε״ at Microwave frequency, static dielectric constant (ε0 and dielectric constant at infinite dilution (ε∞ at optical frequency have been determined. From the measured dielectric data, the relaxation time (t calculated using Higasi method and activation energies (∆Ft and ∆Fη have been determined. All the dielectric parameters that are vary with the substitutent change in benzyl alcohol andchain length of acrylic esters. Suggests that, the proton donating ability is varying with the substitution of benzyl alcohol and proton accepting ability is varying with the chain length of acrylic esters. The relaxation time and molar free energy activation of 1:1 molar ratio is greater than other higher molar ratios (i.e. 3:1, 2:1, 1:2, 1:3 confirm that the existence of most likely 1:1 complex formation between the studied systems and also complex formation formed between free hydroxyl group of substituted benzyl alcohols and carbonyl group of acrylic esters (MMA and EMA.

  14. Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron

    Institute of Scientific and Technical Information of China (English)

    MENG Ya-feng; GUAN Bao-hong; WU Zhong-biao; WANG Da-hui

    2006-01-01

    Sorption of carbon tetrachloride (CT) by zero-valent iron (ZVI) is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVI is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide (CPB) was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide (CTAB) was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations (CMC) and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation.

  15. Improved risk estimates for carbon tetrachloride. Project status report and technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Nikula, K.J.; Barr, E.B. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Lovelace Respiratory Research Inst.; Springer, D.L.; Thrall, K.D. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-09-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. High levels of CCl{sub 4} at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The overall purpose of these studies is to improve the scientific basis for assessing the health risk associated with human exposure to CCl{sub 4}. Specifically, the authors will determine the toxicokinetics of inhaled and ingested CCl{sub 4} in F344/Crl rats. B6C3F{sub 1} mice, and Syrian hamsters. They will also evaluate species differences in the metabolism of CCl{sub 4} by rats, mice, hamsters, and man. Dose-response relationships will be determined in all these studies. This information will be used to improve the physiologically based pharmacokinetic (PBPK) model for CCl{sub 4} originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). The authors will also provide scientific evidence that CCl{sub 4}, like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation.

  16. Removal of Technetium, Carbon Tetrachloride, and Metals from DOE Properties - Final Report

    International Nuclear Information System (INIS)

    This research is a three year project involving close collaboration between chemists at Pennsylvania State University and materials scientists at Pacific Northwest National Laboratory (PNNL). The goal of the project is the development and characterization of supported reducing agents, and solid waste forms derived from them, which will be effective in remediation of aqueous wastes. The work follows the recent discovery that zero-valent metals, such as iron, are effective decontaminants for waste streams containing chlorinated hydrocarbons. Preliminary data, obtained at Penn State and elsewhere, have shown that the same strategy will be effective in reducing soluble compounds containing toxic metals (technetium, lead, mercury, and chromium) to insoluble forms. The Penn State group has prepared a new class of powerful reducing agents, called Ferragels, which consist of finely divided zero-valent metals on high surface area supports. Because the rate of the surface oxidation-reduction reaction depends on available surface area, Ferragels are more effective in every case tested to date than unsupported metals. The project will further develop and investigate the application of these composite materials to problems relevant to the DOE-EM mission, namely the detoxification of waste streams containing technetium, carbon tetrachloride, and toxic metal ions. The Penn State group will work closely with the PNNL group to prepare materials that are compatible with the highly corrosive liquid fraction of Hanford site tank waste, to conduct tests with waste simulants containing technetium, and to formulate and characterize vitrified waste forms derived from these materials

  17. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y. Mauricio; Vrabec, Jadran

    2016-03-01

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values.

  18. Mutual diffusion of binary liquid mixtures containing methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride.

    Science.gov (United States)

    Guevara-Carrion, Gabriela; Janzen, Tatjana; Muñoz-Muñoz, Y Mauricio; Vrabec, Jadran

    2016-03-28

    Mutual diffusion coefficients of all 20 binary liquid mixtures that can be formed out of methanol, ethanol, acetone, benzene, cyclohexane, toluene, and carbon tetrachloride without a miscibility gap are studied at ambient conditions of temperature and pressure in the entire composition range. The considered mixtures show a varying mixing behavior from almost ideal to strongly non-ideal. Predictive molecular dynamics simulations employing the Green-Kubo formalism are carried out. Radial distribution functions are analyzed to gain an understanding of the liquid structure influencing the diffusion processes. It is shown that cluster formation in mixtures containing one alcoholic component has a significant impact on the diffusion process. The estimation of the thermodynamic factor from experimental vapor-liquid equilibrium data is investigated, considering three excess Gibbs energy models, i.e., Wilson, NRTL, and UNIQUAC. It is found that the Wilson model yields the thermodynamic factor that best suits the simulation results for the prediction of the Fick diffusion coefficient. Four semi-empirical methods for the prediction of the self-diffusion coefficients and nine predictive equations for the Fick diffusion coefficient are assessed and it is found that methods based on local composition models are more reliable. Finally, the shear viscosity and thermal conductivity are predicted and in most cases favorably compared with experimental literature values. PMID:27036455

  19. Comparative efficiency of microbial systems for destroying carbon tetrachloride contamination in Hanford groundwater

    International Nuclear Information System (INIS)

    Past waste disposal practices at the US Department of Energy's (DOE) Hanford site have resulted in carbon tetrachloride (CCl4) and nitrate contamination in the groundwater. In situ bioremediation is currently being investigated as a cost effective means to destroy these groundwater contaminants. The cost effectiveness of bioremediation is significantly influenced by the nutrient amendments required to sustain the contaminant destruction reactions. This is particularly important for bioremediation of CCl4 because its biodestruction is the result of a cometabolic process. Nutrient amendments are also important in controlling the growth characteristics of the bacteria to prevent biofouling. Current and previous research has focused on determining the reaction kinetics and microbial processes for CCl4 destruction using acetate as the electron donor for indigenous microbes. This study was conducted to determine if electron donors other than acetate may be more cost effective, or may provide a better means of process control, for in situ bioremediation of CCl4 contamination. Three alternative electron donors, glycerol, methanol, and ethanol, were screened for their ability to stimulate CCl4 destruction. Detailed reaction kinetic experiments using an indigenous microbial consortium with these substrates and with acetate were conducted to determine the efficiency of each in destroying CCl4

  20. Iron-Sulfide-Associated Products Formed during Reductive Dechlorination of Carbon Tetrachloride.

    Science.gov (United States)

    Lan, Ying; Butler, Elizabeth C

    2016-06-01

    This paper investigated the mackinawite (FeS)-associated products formed during reaction between FeS and carbon tetrachloride (CT) at pH 7 and 8. At pH 8, reaction of FeS with CT led to formation of abundant spherical particles with diameters between 50 and 400 nm on the FeS surface and in solution; far fewer such particles were observed at pH 7. Analysis of the FeS surface by energy dispersive X-ray spectroscopy after reaction with CT at pH 8 showed decreased sulfur and elevated oxygen compared to unreacted FeS. The spherical particles that formed upon FeS reaction with CT were mostly amorphous with localized areas of poorly crystalline two-line ferrihydrite. X-ray photoelectron spectroscopy indicated that the predominant Fe surface species after reaction with CT at pH 8 was Fe(III)-O, consistent with ferrihydrite and other amorphous iron (hydr)oxides as major products. Powder X-ray diffraction analysis suggested formation of greigite upon reaction of FeS with CT at pH 7. Both ferrihydrite and Fe(2+), which is a product of greigite dissolution, can react with dissolved HS(-) to form FeS, suggesting that, after oxidation by chlorinated aliphatics, FeS can be regenerated by addition or microbial generation of sulfide. PMID:27138348

  1. Simultaneous biodegradation of carbon tetrachloride and trichloroethylene in a coupled anaerobic/aerobic biobarrier.

    Science.gov (United States)

    Kwon, Kiwook; Shim, Hojae; Bae, Wookeun; Oh, Juhyun; Bae, Jisu

    2016-08-01

    Simultaneous biodegradation of carbon tetrachloride (CT) and trichloroethylene (TCE) in a biobarrier with polyethylene glycol (PEG) carriers was studied. Toluene/methanol and hydrogen peroxide (H2O2) were used as electron donors and an electron acceptor source, respectively, in order to develop a biologically active zone. The average removal efficiencies for TCE and toluene were over 99.3%, leaving the respective residual concentrations of ∼12 and ∼57μg/L, which are below or close to the groundwater quality standards. The removal efficiency for CT was ∼98.1%, with its residual concentration (65.8μg/L) slightly over the standards. TCE was aerobically cometabolized with toluene as substrate while CT was anaerobically dechlorinated in the presence of electron donors, with the respective stoichiometric amount of chloride released. The oxygen supply at equivalent to 50% chemical oxygen demand of the injected electron donors supported successful toluene oxidation and also allowed local anaerobic environments for CT reduction. The originally augmented (immobilized in PEG carriers) aerobic microbes were gradually outcompeted in obtaining substrate and oxygen. Instead, newly developed biofilms originated from indigenous microbes in soil adapted to the coupled anaerobic/aerobic environment in the carrier for the simultaneous and almost complete removal of CT, TCE, and toluene. The declined removal rates when temperature fell from 28 to 18°C were recovered by doubling the retention time (7.2 days). PMID:27054665

  2. Simulation and reference interaction site model theory of methanol and carbon tetrachloride mixtures.

    Science.gov (United States)

    Munaò, G; Costa, D; Saija, F; Caccamo, C

    2010-02-28

    We report molecular dynamics and reference interaction site model (RISM) theory of methanol and carbon tetrachloride mixtures. Our study encompasses the whole concentration range, by including the pure component limits. We majorly focus on an analysis of partial, total, and concentration-concentration structure factors, and examine in detail the k-->0 limits of these functions. Simulation results confirm the tendency of methanol to self-associate with the formation of ring structures in the high dilution regime of this species, in agreement with experimental studies and with previous simulations by other authors. This behavior emerges as strongly related to the high nonideality of the mixture, a quantitative estimate of which is provided in terms of concentration fluctuation correlations, through the structure factors examined. The interaggregate correlation distance is also thereby estimated. Finally, the compressibility of the mixture is found in good agreement with experimental data. The RISM predictions are throughout assessed against simulation; the theory describes better the apolar solvent than the alcohol properties. Self-association of methanol is qualitatively reproduced, though this trend is much less marked in comparison with simulation results.

  3. A comprehensive estimate for loss of atmospheric carbon tetrachloride (CCl4) to the ocean

    Science.gov (United States)

    Butler, James H.; Yvon-Lewis, Shari A.; Lobert, Jurgen M.; King, Daniel B.; Montzka, Stephen A.; Bullister, John L.; Koropalov, Valentin; Elkins, James W.; Hall, Bradley D.; Hu, Lei; Liu, Yina

    2016-09-01

    Extensive undersaturations of carbon tetrachloride (CCl4) in Pacific, Atlantic, and Southern Ocean surface waters indicate that atmospheric CCl4 is consumed in large amounts by the ocean. Observations made on 16 research cruises between 1987 and 2010, ranging in latitude from 60° N to 77° S, show that negative saturations extend over most of the surface ocean. Corrected for physical effects associated with radiative heat flux, mixing, and air injection, these anomalies were commonly on the order of -5 to -10 %, with no clear relationship to temperature, productivity, or other gross surface water characteristics other than being more negative in association with upwelling. The atmospheric flux required to sustain these undersaturations is 12.4 (9.4-15.4) Gg yr-1, a loss rate implying a partial atmospheric lifetime with respect to the oceanic loss of 183 (147-241) yr and that ˜ 18 (14-22) % of atmospheric CCl4 is lost to the ocean. Although CCl4 hydrolyzes in seawater, published hydrolysis rates for this gas are too slow to support such large undersaturations, given our current understanding of air-sea gas exchange rates. The even larger undersaturations in intermediate depth waters associated with reduced oxygen levels, observed in this study and by other investigators, strongly suggest that CCl4 is ubiquitously consumed at mid-depth, presumably by microbiota. Although this subsurface sink creates a gradient that drives a downward flux of CCl4, the gradient alone is not sufficient to explain the observed surface undersaturations. Since known chemical losses are likewise insufficient to sustain the observed undersaturations, this suggests a possible biological sink for CCl4 in surface or near-surface waters of the ocean. The total atmospheric lifetime for CCl4, based on these results and the most recent studies of soil uptake and loss in the stratosphere is now 32 (26-43) yr.

  4. Dechlorination of carbon tetrachloride by the catalyzed Fe-Cu process

    Institute of Scientific and Technical Information of China (English)

    XU Wen-ying; GAO Ting-yao

    2007-01-01

    The electrochemical reduction characteristics of carbon tetrachloride (CT) were investigated using cyclic voltammetry in this study. In addition, the difference in reduction mechanisms of CT between Master Builders' iron and the catalyzed Fe-Cu process was discussed. The results showed that CT was reduced directly on the surface of copper rather than by atomic hydrogen produced at the cathode in the catalyzed Fe-Cu process. The reduction was realized largely by atomic hydrogen in Master Builders' iron. The entire CT in 350 ml aqueous solution with 320 mg/L was reduced to trichloromethane and dichloromethane in 2.25 h when 100 g of scrap iron with Fe/Cu ratio of 10:1 (w/w) were used. Moreover, the reduction rate slowed with time. CT could be reduced at acidic, neutral and alkaline pH from solution by Fe-Cu bimetallic media, but the mechanisms were different. The degradation rate was not significantly influenced by pH in the catalyzed Fe-Cu process; in Master Builders' iron it clearly increased with decreasing pH. The kinetics of the reductions followed pseudo-first order in both cases. Furthermore, the reductions under acidic conditions proceeded faster than that under the neutral and alkaline conditions. The catalyzed Fe-Cu process was superior to Master Builders' iron in treating CT-containing water and this advantage was particularly noticeable under alkaline conditions. The reduction was investigated in the cathode (Cu) and anode (Fe) compartments respectively, the results showed that the direct reduction pathway played an important role in the reduction by the catalyzed Fe-Cu process. The catalyzed Fe-Cu process is of practical value.

  5. Hepatoprotective activity of the neem-based constituent azadirachtin-A in carbon tetrachloride intoxicated Wistar rats.

    Science.gov (United States)

    Baligar, N S; Aladakatti, R H; Ahmed, Mukhtar; Hiremath, M B

    2014-04-01

    The aim of this study was to investigate the hepatoprotective role of azadirachtin-A in carbon tetrachloride (CCl4) induced hepatotoxicity in rats. The group allotment for the animals used in the hepatoprotective study included a vehicle treatment group, CCl4 (1 mL · (kg body mass)(-1)) treatment group, silymarin (100 μg · (kg body mass)(-1) · day(-1)) + CCl4 treatment group, and groups treated with different doses of azadirachtin-A (100 or 200 μg · (kg body mass)(-1) · day(-1)) + CCl4. On the 9th day, blood was obtained for measuring the biochemical parameters, and liver tissue was obtained for pathological examination. The acute toxicity test with azadirachtin-A (500, 1000, or 2000 μg · (kg body mass)(-1)) indicated no mortality after 14 days of treatment; further, there was no change in behavior, food consumption, or organ mass. However with the higher dose, some hematological parameters showed changes. Hepatoprotective studies revealed that the CCl4 treatment group exhibited a decrease in total protein and albumin levels, whereas a significant increase in BUN, AST, ALT, and ALP levels were noticed compared with the vehicle-treated control, indicating that there was liver damage caused by CCl4. Histology and ultrastructure study confirmed that pretreatment with azadirachtin-A dose-dependently reduced hepatocellular necrosis and, therefore, protected the liver against toxicity caused by CCl4. The results from this study indicate that pretreatment with azadirachtin-A at the higher dose levels, moderately restores the rat liver to normal. This study confirms that azadirachtin-A possesses greater hepatoprotective action; however, the effective concentration needs to be determined. PMID:24708208

  6. Treatment with L-valine ameliorates liver fibrosis and restores thrombopoiesis in rats exposed to carbon tetrachloride.

    Science.gov (United States)

    Nakanishi, Chikashi; Doi, Hideyuki; Katsura, Kazunori; Satomi, Susumu

    2010-06-01

    It has been reported that treatment with branched chain amino acids (BCAAs) increases the survival rates in cirrhotic patients. In this study, we investigated the effect of L-valine, one of BCAAs, on liver fibrosis in rat. To induce liver fibrosis, male Wistar rats were injected carbon tetrachloride (CCl(4)) intraperitoneally (2.0 mL/kg) twice a week for 12 weeks. The rats (seven to fifteen rats for each group) were then administered 1.688 g/kg/day of L-valine intravenously for 7 days or 10% amino acid preparation that provided the same amount of nitrogen. Seven days after the last administration, blood platelet counts and bone marrow megakaryocyte counts were significantly higher in the valine group than in the control group (131.2 +/- 38.3 vs. 106.3 +/- 14.5 x 10(4)/microL, p = 0.04; 18.0 +/- 2.1 vs. 13.5 +/- 2.2 per field, p valine group than the control group. Furthermore, hepatic fibrosis was significantly reduced in the valine group, and the mRNA levels of factors associated with liver fibrosis such as procollagen alpha1(III), transforming growth factor-beta1 and connective tissue growth factor were significantly lower in the liver of the valine group 10 days after the last administration. These results indicate that L-valine treatment ameliorates liver fibrosis and restores thrombopoiesis in rats exposed to CCl(4). Therefore, L-valine supplementation may be helpful for patients with liver cirrhosis.

  7. Performance and Serum Hepatic Enzymes of Hy-Line W-36 Laying Hens Intoxicated with Dietary Carbon Tetrachloride

    Directory of Open Access Journals (Sweden)

    Hadavi A

    2015-12-01

    Full Text Available An experiment was conducted to study the effects of carbon tetrachloride (CCl4 on post-peak performance and serum enzymes of Hy-Line W-36 laying hens from 32-36 weeks of age. The experiment was carried out with a total of 192 laying hens in a completely randomized block design. During the experiment laying hens were allocated to 4 groups consisted of T1 no CCl4 as control diet, T2, T3 and T4 control diet supplemented with 1, 3 and 5 mL CCl4/100 g diet, respectively. Each experimental group was divided into 6 blocks of 8 hens each. Egg production, cracked egg percentage and feed intake were recorded weekly. Blood samples were taken from wing veins of hens at the middle and end of the experiment to measure serum hepatic enzymes of alkaline phosphatase, alanine aminotransferase and aspartate aminotransferase. Data showed that in comparison with the control group, the inclusion of CCl4 to the diets had no significant effect on performance parameters. However, by increasing the level of CCl4, egg production was linearly decreased and feed intake was linearly increased (P < 0.05. The effect of CCl4 on cracked eggs was significant and this effect was linearly increased (P < 0.05. Dietary supplementation of 3 and 5 mL CCl4 elevated the serum concentration of hepatic enzymes of alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase, linearly (P < 0.0001. In conclusion, the dietary supplementation of CCl4 has the ability to decrease the performance and egg quality. CCl4 is also a potent hepatic toxicity inducer and may damage liver hepatocytes. Therefore, the level of 3 mL CCl4 was assigned as the one had the maximum negative effect on serum hepatic enzymes concentration (maximum liver damage alongside the minimum negative effect on laying hen performance for further studies.

  8. Implementing and operating the Hanford Environmental Information System and applying it to the carbon tetrachloride expedited response action

    International Nuclear Information System (INIS)

    To manage waste and perform environmental monitoring and restoration at the 1450-square kilometer (560-square mile) Hanford Site in southeastern Washington State, vast amounts of scientific and technical data are being generated from sampling. This paper provides an overview of the Hanford Environmental Information System (HEIS), a computerized system designed and implemented to manage the Site's environmental sampling data, lessons learned from putting HEIS into operation, and how HEIS is being applied to the carbon tetrachloride expedited response action being performed at the Site

  9. Full molecular dynamics simulations of liquid water and carbon tetrachloride for two-dimensional Raman spectroscopy in the frequency domain

    CERN Document Server

    Jo, Ju-Yeon; Tanimura, Yoshitaka

    2016-01-01

    Frequency-domain two-dimensional Raman signals, which are equivalent to coherent two-dimensional Raman scattering (COTRAS) signals, for liquid water and carbon tetrachloride were calculated using an equilibrium-nonequilibrium hybrid MD simulation algorithm. We elucidate mechanisms governing the 2D signal pro?les involving anharmonic mode-mode coupling and the nonlinearities of the polarizability for the intermolecular and intramolecular vibrational modes. The predicted signal pro?les and intensities can be utilized to analyze recently developed single-beam 2D spectra, whose signals are generated from a coherently controlled pulse, allowing the single-beam measurement to be carried out more efficiently.

  10. Performance and Serum Hepatic Enzymes of Hy-Line W-36 Laying Hens Intoxicated with Dietary Carbon Tetrachloride

    OpenAIRE

    Hadavi A; Kermanshahi H; Nassiri Moghaddam H; Golian A

    2015-01-01

    An experiment was conducted to study the effects of carbon tetrachloride (CCl4) on post-peak performance and serum enzymes of Hy-Line W-36 laying hens from 32-36 weeks of age. The experiment was carried out with a total of 192 laying hens in a completely randomized block design. During the experiment laying hens were allocated to 4 groups consisted of T1) no CCl4 as control diet, T2, T3 and T4) control diet supplemented with 1, 3 and 5 mL CCl4/100 g diet, respectively. Each experimental group...

  11. Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Rui [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Cao, Li-Ping; Du, Jin-Liang [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Wang, Jia-Hao; Liu, Ying-Juan [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Jeney, Galina [National Agricultural Research Center, Research Institute for Fisherie and, Aquaculture, Anna Light 8, Szarvas 5440 (Hungary); Xu, Pao, E-mail: xup@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Yin, Guo-Jun, E-mail: yingj@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China)

    2014-07-01

    Highlights: • We explored the underlying toxicology of CCl{sub 4} at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl{sub 4} activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl{sub 4})-induced hepatotoxicity in fish was investigated by studying the effects of CCl{sub 4} on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl{sub 4} in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl{sub 4} at 8 mM. The results showed that CCl{sub 4} significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl{sub 4} caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl{sub 4}-induced hepatotoxicity in fish.

  12. 乙胺嗪对四氯化碳致急性肝损伤大鼠的保护作用%Hepatoprotective effects of diethylcarbamazine in acute liver damage induced by carbon tetrachloride in rats

    Institute of Scientific and Technical Information of China (English)

    Gonzàlez R; Ancheta O; Màrquez M; Rodriguez S

    1994-01-01

    This research was carried out to determine a potential role of leukotrienes in the acute hepatotoxicity induced by CCl4 in rats. An inhibitor of leukotrienes biosynthesis,diethylcarbamazine (DEC, 25 and 50 mg creasing the activity of alanine aminotransferase in serum and the concentration of liver triglycerides. DEC reduced histological damage of liver evidenced by electron micr oscopy.The hepatoprotective effects of DEC were dose-dependent. The results favor the role of leukotrienes in CCl4 hepatotoxicity.

  13. Improved risk estimated from carbon tetrachloride. Annual progress report, October 1, 1996--September 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.

    1997-10-27

    'Carbon tetrachloride (CCl{sub 4}) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. Rocky Flats was formerly the largest volume user of CCl{sub 4} in the US, with 5,000 gallons used there in 1977 alone. At the Hanford site, several hundred thousand gallons of CCl{sub 4} were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl{sub 4} in groundwater at highly contaminated sites at the Hanford. facility have exceeded the drinking water standard of 5 ppb by several orders of magnitude. High levels of CCl{sub 4} at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl{sub 4} cleanup required at these sites and associated costs are driven by current human health risk estimates which assume that CCl{sub 4} is a genotoxic carcinogen. The overall purpose of these studies is to improve the scientific basis for assessing the health risk associated with human exposure to CCl{sub 4}. Specifically, the authors will determine the toxicokinetics of inhaled and ingested CCl{sub 4} in F344/Crl rats, B6C3F1 mice, and Syrian hamsters. They will also evaluate species differences in the metabolism of CCl{sub 4} by rats, mice, hamsters, and man. Dose-response relationships will be determined in all these studies. This information will be used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). They will also provide scientific evidence that CCl{sub 4} , like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation. In combination, the studies outlined in this proposal will provide the exact types of information needed to enable refined cancer risk estimates for CCl{sub 4} under the new guidelines for risk assessment proposed by

  14. Carbon tetrachloride-induced liver injury in the rabbit.

    OpenAIRE

    Bernacchi, A. S.; de Castro, C. R.; de Ferreyra, E. C.; Villarruel, M. C.; Fernández, G.; de Fenos, O. M.; Castro, J.A.

    1983-01-01

    CCl4 administration to rabbits leads to early destruction of liver microsomal cytochrome P-450, to depression of glucose 6 phosphatase, to ultrastructurally revealable alterations and to an intense necrosis and fat accumulation in liver. Despite the known resistance of rabbit liver microsomes to lipid peroxidation, CCl4 administration to rabbits promoted lipid peroxidation of their liver microsomal lipids as revealable by the diene hyperconjugation technique, at periods of time from 1 to 12 h...

  15. Reaction of carbon tetrachloride with methane in a non-equilibrium plasma at atmospheric pressure, and characterisation of the polymer thus formed

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Vaibhav [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia); Kennedy, Eric, E-mail: Eric.Kennedy@newcastle.edu.au [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia); Mackie, John [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia); Holdsworth, Clovia [Centre for Organic Electronics, Chemistry Building, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia); Molloy, Scott; Kundu, Sazal; Stockenhuber, Michael [Process Safety and Environment Protection Research Group, School of Engineering, The University of Newcastle, Callaghan, NSW 2308 (Australia); Dlugogorski, Bogdan [School of Engineering and Information Technology, Murdoch University, Murdoch, WA 6150 (Australia)

    2014-09-15

    Highlights: • CCl{sub 4} remediation using non-equilibrium plasma and non-oxidative conditions is proposed. • The reaction mechanism relies on experimental data and quantum chemical analysis. • Comprehensive mass balance for the reaction is provided. • CCl{sub 4} is converted to an environmentally benign and potentially useful polymer. • Characterisation of the polymer structure based on NMR and FTIR analyses is presented. - Abstract: In this paper we focus on the development of a methodology for treatment of carbon tetrachloride utilising a non-equilibrium plasma operating at atmospheric pressure, which is not singularly aimed at destroying carbon tetrachloride but rather at converting it to a non-hazardous, potentially valuable commodity. This method encompasses the reaction of carbon tetrachloride and methane, with argon as a carrier gas, in a quartz dielectric barrier discharge reactor. The reaction is performed under non-oxidative conditions. Possible pathways for formation of major products based on experimental results and supported by quantum chemical calculations are outlined in the paper. We elucidate important parameters such as carbon tetrachloride conversion, product distribution, mass balance and characterise the chlorinated polymer formed in the process.

  16. Interferon-alpha gene therapy prevents aflatoxin and carbon tetrachloride promoted hepatic carcinogenesis in rats.

    Science.gov (United States)

    Aziz, Talaat Abdel; Aziz, Mohammed Abdel; Fouad, Hanan Hassan; Rashed, Laila Ahmed; Salama, Hosny; Abd-Alla, Samira; Wehab, Mosaad Attia Abdel; Ahmed, Tauseef

    2005-01-01

    Retrovirus-mediated interferon alpha (IFN-alpha) gene transfer was evaluated with regard to its possible protective effects against aflatoxin B1 (AFB1)-initiated and carbon tetrachloride (CCl4)-promoted hepatic carcinogenesis in rats. To our knowledge, this is the first time an experimental in vivo gene therapy trial was conducted in Egypt. Two genes were examined in liver tissue by RT-PCR: the first was glutathione-S-transferase placental (GST-P) isoenzyme, as an early marker to detect hepatic malignancy; the second was IFN-alpha gene expression to detect the efficiency of gene uptake and its persistence after transduction. Forty male rats, divided equally into 4 groups, were included in the study: the first group was the control; the second group received CCl4 0.2 ml subcutaneously twice weekly for 12 weeks and AFB1 0.25 mg/kg body wt intraperitoneally twice weekly for 6 weeks; the third group received IFN-alpha (10(8) pfu) intravenously in the tail vein prior to the start of CCl4 and AFB1 injections; and the fourth group received IFN-alpha (10(8) pfu) by intrahepatic injection under ultrasonography guide after termination of the CCl4 and AFB1 injection schedule. The results showed that IFN-alpha has a marked and significant protective effect against hepatic fibrogenesis as well as hepatic carcinogenesis. Pathological examination of liver tissue proved that IFN-alpha minimized both fibrotic and cirrhotic processes. The amount of fibrosis was less in both groups receiving IFN-alpha, with more protection in the group that received IFN-alpha intravenously prior to CCl4 and AFB1. The results of RT-PCR showed that the IFN-alpha gene was significantly expressed in both groups receiving IFN-alpha, with a more intense expression in the group that received IFN-alpha by intrahepatic injection after termination of CCl4 and AFB1 injections. The IFN-alpha gene was detected after three months of gene transduction in rats receiving IFN-alpha intravenously prior to CCl4 and AFB1

  17. Abiotic Degradation Rates for Carbon Tetrachloride: and Chloroform: Progress in FY 2008

    Energy Technology Data Exchange (ETDEWEB)

    Amonette, James E.; Jeffers, Peter M.; Qafoku, Odeta; Russell, Colleen K.; Wietsma, Thomas W.; Truex, Michael J.

    2008-10-31

    This is a letter report summarizing work performed in FY2008 to determine the rates of carbon tetrachloride hydrolysis at temperatures close to actual groundwater temperatures. The report describes the project, the methodology, and the results obtained since the project's inception in FY2006. Measurements of hydrolysis rates in homogeneous solution have been completed for temperaturs of 70 C through 40 C, with additional data available at 30 C and 20 C. These results show no difference between the rates in deionized H2O and in filter-sterilized Hanford-Site groundwater. Moreover, the rates measured are 2-3 times slower than predicted from the open literature. Measurements of rates involving sterile suspensions of Hanford-Site sediment in Hanford-Site groundwater, however, show faster hydrolysis at temperatures below 40 C. Extrapolation of the current data available suggests a six-fold increase in rate would be expected at groundwater temperature of 16 C due to the presence of the sediment. This result translates into a 78-year half-life, rather than the 470-680 year half-life that would be predicted from rate determinations in homogeneous solution. The hydrolysis rate data at 20 C, in contrast to those at higher temperatures, are preliminary and have low statistical power. While significant (p < 0.05) differences between the heterogeneous and homogeneous systems are seen at 30 C, the results at 20 C are not statistically significant at this level due to limited data and the very slow nature of the reaction. More time is needed to collect data at these low temperatures to improve the statistical power of our observation. Given the critical need for hydrolysis rate data at temperatures relevant to groundwater systems, we have three recommendations for future work. First, we recommend a continuation of the sampling and analysis of the remaining long-term sealed-ampule experiments described in this report. These are primarily 20 C and 30 C experiments. The data at

  18. Pulmonary retention and tissue distribution of 239Pu nitrate in F344 rats and syrian hamsters inhaling carbon tetrachloride

    International Nuclear Information System (INIS)

    Carbon tetrachloride (CCl4) has been used extensively in the nuclear weapons industry, so it is possible that nuclear plant workers have been exposed to CCl4 and plutonium compounds. Potential for future exposure exists during open-quotes cleanupclose quotes operations at weapon production sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. The current Threshold Limit Value for CCl4 is 5 ppm; however, concentrations of CCl4 occurring in the nuclear weapons facilities over the past 40-50 y are unknown and may have exceeded this value. The pilot study described in this report is designed to determine whether subchronic inhalation of CCl4 by CDFregister(F-344)/CrlBR rats and Syrian golden hamsters, at concentrations expected to produce some histologic changes in liver, alters the hepatic retention and toxic effects of inhaled 239Pu nitrate 239Pu(NO3)4

  19. CCl4诱导大鼠纤维化肝组织 microRNA 差异表达及其初步分析%Differentially expressed and preliminary analysis of microRNA profiles in liver tissue of rat induced by carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    刘业方; 张传涛; 李白雪; 郭尹玲; 王宝家; 唐洪屈; 王政; 张凤; 杨宇

    2015-01-01

    Objective To explore the differences of expression profiles and significance of the microRNA in liver tissue of rat induced by carbon tetrachloride(CCl4 ).Methods The microRNA differential expression analysis between normal group(n = 10) and model group(n=10)was conducted on high-throughput methods.Gene ontology enrichment analysis and kyoto encyclopedia of genes and genomes pathway analysis of the targets of miRNA were carried out in this study.Results Some differentally expressed microRNA with 29 up-regulated and 8 down-regulated were identified in our study.Through evaluaing the value of microRNA in the network,we find that the key microRNA of rising are miR-184,miR-10b-5p,miR-1 99a-3p,and the key microRNA of cutting are miR-200b-3p,miR-1 99a-5p,miR-125b-5p and so on.Conclusion The microRNA expression level in the model group has a signifi-cant change.Therefore,the courses of liver fibrosis is related to some process which microRNA control the regulation of cell prolif-eration,cell apoptosis,cell cycle,and so on.%目的:探索 microRNA 在四氯化碳(CCl4)诱导的大鼠纤维化肝组织中的差异表达及其意义。方法采用 microR-NA 高通量测序分析技术检测对照组(n=10)与模型组(n=10)肝脏组织 microRNA 表达,对差异 microRNA 进行靶基因预测,对靶基因进行基因本(GO)分析、pathway 分析。结果对照组与模型组间筛选出37个差异 microRNA,上调29个,下调8个;从microRNA-基因网络图中发现关键上调为 miR-184、miR-10b-5p、miR-199a-3p 等;关键下调为 miR-200b-3p、miR-199a-5p、miR-125b-5p 等。结论模型组 microRNA 表达谱变化明显,肝纤维化的形成与 microRNA 调控细胞增殖、凋亡、细胞周期等有关。

  20. Isobaric vapor liquid equilibria data for the binary system (glycidyl butyrate + acetone, glycidyl butyrate + carbon tetrachloride, glycidyl butyrate + chloroform) at atmospheric pressure 101 kPa

    Science.gov (United States)

    Huang, Qiang; Meng, Qingyi; Ban, Chunlan; Zhang, Rui; Gao, Yingyu

    2016-09-01

    Isobaric vapor liquid equilibria (VLE) for the binary mixtures of glycidyl butyrate(1) + acetone(2), glycidyl butyrate(1) + carbon tetrachloride(2) and glycidyl butyrate(1) + chloroform(2) at 101 kPa were studied. The experimental data were satisfactorily correlated with the models of Wilson, NRTL and UNIQUAC activity coefficients. The activity coefficients for the equilibrium data were obtained by the nonlinear least square method. The average relative deviations between experimental temperatures and calculated temperatures by the Wilson, NRTL and UNIQUAC models were 0.16, 0.16, 0.23% for glycidyl butyrate(1) + chloroform( 2), 0.38, 0.12, 0.27% for glycidylbutyrate(1) + carbon tetrachloride(2), and 0.67, 0.13, 0.54% for glycidyl butyrate(1) + acetone(2). Azeotrope behavior was not found for these systems. The thermodynamic consistency of the correlations was checked by the Herrington's area test.

  1. H2O/D2O solubility isotope effects. An estimate of the extent of nonclassical rotational behavior of water, when dissolved in benzene or carbon tetrachloride

    International Nuclear Information System (INIS)

    The solubility of D2O in each of benzene, carbon tetrachloride, and cyclohexane was determined over a range of temperatures. The solubilities were converted to Henry's law constants, which were compared with previously obtained Henry's law constants for H2O in these solvents. This comparison, when made in the context of a recently derived first-order quantum correction to the free energy for a rigid rotor in the presence of other molecules, and approximately corrected for intramolecular frequency shifts, indicates that water, when dissolved in carbon tetrachloride at ordinary temperatures, is rotationally classical or very nearly so. Water in benzene appears to manifest small but noticeable nonclassical rotational behavior, which we estimate to be of the order of 5% in the free energy. Because of the very low solubility of H2O and D2O in cyclohexane, our data were not accurate enough to permit a meaningful discussion in terms of a rotational quantum effect in this solvent

  2. Subchronic inhalation of carbon tetrachloride alters the tissue retention of acutely inhaled plutonium-239 nitrate in F344 rats and syrian golden hamsters

    International Nuclear Information System (INIS)

    Carbon tetrachloride (CCl4) has been used extensively in the nuclear weapons industry, so it is likely that nuclear plant workers have been exposed to both CCl4 and plutonium compounds. Future exposures may occur during open-quotes cleanupclose quotes operations at weapons productions sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. Inhalation of 20 and 100 ppm CCl4 by hamsters reduces uptake of 239Pu solubilized from lung, shunting the 239Pu to the skeleton

  3. CYTOTOXIC ACTIVITY OF N-HEXANE, CHLOROFORM AND CARBON TETRACHLORIDE FRACTIONS OF THE ETHANOLIC EXTRACT OF LEAVES AND STEMS OF BACCAUREA RAMIFLORA (LOUR..

    Directory of Open Access Journals (Sweden)

    Apurba Sarker Apu et al.

    2012-03-01

    Full Text Available The purpose of the study was to find out the cytotoxic activity of the n-hexane, chloroform and carbon tetrachloride fractions of the ethanolic extracts of the leaves and stems of Baccaurea ramiflora (Lour.. Ethanolic extracts of the leaves and stems of Baccaurea ramiflora were subjected to solvent-solvent partitioning using n-hexane, chloroform and carbon tetrachloride to obtain n-hexane leaves fraction, chloroform leaves fraction, n-hexane stems fraction, chloroform stems fraction and carbon tetrachloride stems fraction. Each fraction was assayed for their cytotoxic effect using brine shrimp lethality bioassay. Among the fractions, the n-hexane fractions of leaves and stems showed significant cytotoxic effects having LC50 values of 7.79 µg/ml (95% confidence interval 6.48-9.37 and 5.78 µg/ml (95% confidence interval 4.76-6.99 respectively as compared to vincristine sulfate (LC50= 2.81 µg/ml (95% confidence interval 1.97-4.01 which was used as positive control. The results support the traditional uses of B. ramiflora for various medicinal purposes and thus demand the isolation and identification of active principles and thorough bioassay.

  4. MR T1{rho} as an imaging biomarker for monitoring liver injury progression and regression: an experimental study in rats with carbon tetrachloride intoxication

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng; Wang, Yi-Xiang J.; Yuan, Jing; Deng, Min; Ahuja, Anil T. [Chinese University of Hong Kong, Department of Imaging and Interventional Radiology, Prince of Wales Hospital, Hong Kong SAR (China); Wong, Hing Lok [School of Public Health and Primary Care, Prince of Wales Hospital, The Chinese University of Hong Kong, Jockey Club Centre for Osteoporosis Care and Control, Hong Kong SAR (China); Chu, Eagle S.H.; Go, Minnie Y.Y.; Yu, Jun [Chinese University of Hong Kong, Institute of Digestive Disease and Department of Medicine and Therapeutics, Li Ka Shing Institute of Health Sciences, Hong Kong SAR (China); Teng, Gao-Jun [Southeast University, Department of Radiology, Zhongda Hospital, Nanjing (China)

    2012-08-15

    Recently it was shown that the magnetic resonance imaging (MRI) T1{rho} value increased with the severity of liver fibrosis in rats with bile duct ligation. Using a rat carbon tetrachloride (CCl{sub 4}) liver injury model, this study further investigated the merit of T1{rho} relaxation for liver fibrosis evaluation. Male Sprague-Dawley rats received intraperitoneal injection of 2 ml/kg CCl{sub 4} twice weekly for up to 6 weeks. Then CCl{sub 4} was withdrawn and the animals were allowed to recover. Liver T1{rho} MRI and conventional T2-weighted images were acquired. Animals underwent MRI at baseline and at 2 days, 2 weeks, 4 weeks and 6 weeks post CCl{sub 4} injection, and they were also examined at 1 week and 4 weeks post CCl{sub 4} withdrawal. Liver histology was also sampled at these time points. Liver T1{rho} values increased slightly, though significantly, on day 2, and then increased further and were highest at week 6 post CCl{sub 4} insults. The relative liver signal intensity change on T2-weighted images followed a different time course compared with that of T1{rho}. Liver T1{rho} values decreased upon the withdrawal of the CCl{sub 4} insult. Histology confirmed the animals had typical CCl{sub 4} liver injury and fibrosis progression and regression processes. MR T1{rho} imaging can monitor CCl{sub 4}-induced liver injury and fibrosis. (orig.)

  5. MR T1ρ as an imaging biomarker for monitoring liver injury progression and regression: an experimental study in rats with carbon tetrachloride intoxication

    International Nuclear Information System (INIS)

    Recently it was shown that the magnetic resonance imaging (MRI) T1ρ value increased with the severity of liver fibrosis in rats with bile duct ligation. Using a rat carbon tetrachloride (CCl4) liver injury model, this study further investigated the merit of T1ρ relaxation for liver fibrosis evaluation. Male Sprague-Dawley rats received intraperitoneal injection of 2 ml/kg CCl4 twice weekly for up to 6 weeks. Then CCl4 was withdrawn and the animals were allowed to recover. Liver T1ρ MRI and conventional T2-weighted images were acquired. Animals underwent MRI at baseline and at 2 days, 2 weeks, 4 weeks and 6 weeks post CCl4 injection, and they were also examined at 1 week and 4 weeks post CCl4 withdrawal. Liver histology was also sampled at these time points. Liver T1ρ values increased slightly, though significantly, on day 2, and then increased further and were highest at week 6 post CCl4 insults. The relative liver signal intensity change on T2-weighted images followed a different time course compared with that of T1ρ. Liver T1ρ values decreased upon the withdrawal of the CCl4 insult. Histology confirmed the animals had typical CCl4 liver injury and fibrosis progression and regression processes. MR T1ρ imaging can monitor CCl4-induced liver injury and fibrosis. (orig.)

  6. The formation of sinusoidal capillarization in the process of liver fibrosis induced by carbon tetrachloride in rats%四氯化碳诱导的肝纤维化大鼠肝窦毛细血管化的形成

    Institute of Scientific and Technical Information of China (English)

    郭杞兰; 黄月红; 陈治新; 王小众

    2014-01-01

    Objective To observe the formation of sinusoidal capillarization in the process of liver fibrosis induced by carbon tetrachloride (CCl4 )in rats,and to explore the relevance between sinusoidal capillarization and hepatic fibrosis. Methods Thirty-two SD rats were divided randomly into control group (group N)and fibrosis model group (group M). Rats in group N were treated with 2 ml/kg normal sodium twice a week for eight weeks via intraperitoneal injection,while rats in group M were treated with 2 ml/kg a mixture of 50% CCl4 and castor oil twice a week for eight weeks. Rats were executed at the end of 2th wk,4th wk,6th wk,8th wk to collect samples of liver tissue and serum. Grading and staging of hepatic fibrosis were measured by HE staining and masson staining. Changes of HA from serum were measured by radioimmunoassay. Structure of sinus wall in liver sinusoids was observed by TEM. Expressions of CD3 1 ,LN and Col-IV in liver tissue were measured by S-P immunohistochemistry. Results Liver pathohistology analysis confirmed that hepatic fibrosis rat model induced by CCl4 was established successfully. Fibrous septum could be observed at the end of 6th wk. TEM showed that fenestrae of some liver sinusoidal endothelial cells (LSECs)diminished after treated with CCl4 for two weeks with observing no basement membrane (BM). Fenestrae of LSECs diminished along with the development of hepatic fibrosis,even disappeared. Consecutive BM formed at the end of 6th wk~8th wk in local sinusoidal endothelium. Concentration of HA from serum,and expressions of CD31 ,Col-IV and LN in hepatic sinusoids increased gradually along with development of hepatic fibrosis. Conclusion Formation of sinusoidal capillarization was occurred gradually along with development of hepatic fibrosis. Fibrous septa formed later than fenestrae losing in LSECs,but earlier than formation of sinusoidal endothelial basement membrane.%目的:观察四氯化碳(CCl4)诱导的大鼠肝纤维化过程中肝窦

  7. Dielectric properties of liquid systems: study of interactions in the systems carbon tetrachloride with benzene, toluene, and p-xylene

    Directory of Open Access Journals (Sweden)

    Adrián H. Buep

    2014-12-01

    Full Text Available Intermolecular associations in liquid systems of non-polar and slightly polar compounds were studied through excess molar volumes (VEM and excess dielectric properties (εE and n2ED for mixtures of carbon tetrachloride (CCl4 with benzene (C6H6, toluene (C6H5CH3, and p-xylene (p-(CH32C6H4. These excess properties were calculated from measurements of density (ρ, static permittivity (ε, and refractive index (nD over the whole range of concentrations at 298.15 K. The values of the excess dielectric properties for these mixtures were fitted in two different ways, one through least squares using the Redlich–Kister equation and the other using a model developed to explain deviations from ideality. The first fit was found to be descriptive while the second gave the equilibrium constant values for the interaction products actually formed in the mixtures and the respective electronic polarizabilities and dipole moments, indicating the existence of interaction products.

  8. Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses

    Science.gov (United States)

    Hu, Lei; Montzka, Stephen A.; Miller, Ben R.; Andrews, Arlyn E.; Miller, John B.; Lehman, Scott J.; Sweeney, Colm; Miller, Scot M.; Thoning, Kirk; Siso, Carolina; Atlas, Elliot L.; Blake, Donald R.; de Gouw, Joost; Gilman, Jessica B.; Dutton, Geoff; Elkins, James W.; Hall, Bradley; Chen, Huilin; Fischer, Marc L.; Mountain, Marikate E.; Nehrkorn, Thomas; Biraud, Sebastien C.; Moore, Fred L.; Tans, Pieter

    2016-03-01

    National-scale emissions of carbon tetrachloride (CCl4) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration's flask air sampling network. We estimate an annual average US emission of 4.0 (2.0-6.5) Gg CCl4 y-1 during 2008-2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y-1) but only 8% (3-22%) of global CCl4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl4 emission during 2008-2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

  9. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

    Science.gov (United States)

    Xiao, X.; Prinn, R. G.; Fraser, P. J.; Weiss, R. F.; Simmonds, P. G.; O'Doherty, S.; Miller, B. R.; Salameh, P. K.; Harth, C. M.; Krummel, P. B.; Golombek, A.; Porter, L. W.; Butler, J. H.; Elkins, J. W.; Dutton, G. S.; Hall, B. D.; Steele, L. P.; Wang, R. H. J.; Cunnold, D. M.

    2010-11-01

    Carbon tetrachloride (CCl4) has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CCl4 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996-2004. The Model of Atmospheric Transport and Chemistry (MATCH), driven by offline National Center for Environmental Prediction (NCEP) reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions.

  10. Angiotensin-converting enzyme inhibitor prevents oxidative stress, inflammation, and fibrosis in carbon tetrachloride-treated rat liver.

    Science.gov (United States)

    Reza, Hasan Mahmud; Tabassum, Nabila; Sagor, Md Abu Taher; Chowdhury, Mohammed Riaz Hasan; Rahman, Mahbubur; Jain, Preeti; Alam, Md Ashraful

    2016-01-01

    Hepatic fibrosis is a common feature of chronic liver injury, and the involvement of angiotensin II in such process has been studied earlier. We hypothesized that anti-angiotensin II agents may be effective in preventing hepatic fibrosis. In this study, Long Evans female rats were used and divided into four groups such as Group-I, Control; Group-II, Control + ramipril; Group-III, CCl4; and Group-IV, CCl4 + ramipril. Group II and IV are treated with ramipril for 14 d. At the end of treatment, the livers were removed, and the level of hepatic marker enzymes (aspartate aminotransferase, Alanine aminotransferase, and alkaline phosphatase), nitric oxide, advanced protein oxidation product , catalase activity, and lipid peroxidation were determined. The degree of fibrosis was evaluated through histopathological staining with Sirius red and trichrome milligan staining. Carbon-tetrachloride (CCl4) administration in rats developed hepatic dysfunction and raised the hepatic marker enzymes activities significantly. CCl4 administration in rats also produced oxidative stress, inflammation, and fibrosis in liver. Furthermore, angiotensinogen-inhibitor ramipril normalized the hepatic enzymes activities and improved the antioxidant enzyme catalase activity. Moreover, ramipril treatment ameliorated lipid peroxidation and hepatic inflammation in CCl4-treated rats. Ramipril treatment also significantly reduced hepatic fibrosis in CCl4-administered rats. In conclusion, our investigation suggests that the antifibrotic effect of ramipril may be attributed to inhibition of angiotensin-II mediated oxidative stress and inflammation in liver CCl4-administered rats. PMID:26862777

  11. Effects of cyclooxygenase-2 on sinusoidal capillarization in cirrhotic rats induced by carbon tetrachloride%环氧合酶-2在四氯化碳诱导肝硬化大鼠肝窦毛细血管化形成中的作用

    Institute of Scientific and Technical Information of China (English)

    涂传涛; 王吉耀; 郭津生

    2009-01-01

    目的 观察环氧合酶-2(COX-2)在实验性肝硬化大鼠肝窦毛细血管化形成中的作用.方法 腹腔注射CCl4每周2次共8周诱导雄性SD大鼠肝硬化模型.将SD大鼠分成3组:正常对照组(n=10)、模型对照组(n=15)和罗非昔布治疗组(10 mg·kg-1·d-1,n=15).光镜下观察肝组织标本,电镜观察肝窦超微结构改变.用Western印迹和免疫组化法检测基底膜蛋白主要成分层粘连蛋白(LN)和Ⅳ型胶原,同时通过Ⅷ因子相关抗原(vWF)免疫组化标记微血管牛成密度.结果 与模型对照组相比,罗非昔布干预治疗能减少肝纤维化面积(分别为30.7±8.9和23.5±6.5,P<0.05).光镜及电镜提示,在模型对照组可见肝窦内皮细胞窗孔减少、缩小,有完整的基底膜形成,Disse腔隙内有大量的胶原纤维沉积,罗非昔布组上述病变有所减轻.随着肝硬化的形成,肝组织微血管密度明显升高,罗非昔布组肝组织微血管密度(6.4±0.7)较模型对照组(11.3±1.6)明显降低(P<0.01).肝硬化时肝组织表达Ⅳ型胶原和LN蛋白明显增加(分别为3.8±0.4和3.7±0.5),罗非昔布能降低Ⅳ犁胶原和LN的表达(分别为3.0±0.5和3.0±0.5;与模型对照组相比两者均为Pcarbon tetrachloride (CCl4) twice a week for 8 weeks to induce liver cirrhosis. The rats were randomly divided into three groups: normal control group (n= 10), model control group (n= 15) and rofecoxib treated group (received 10 mg/kg of rofecoxib daily, n = 15). Liver histopathology was examined by light microscopy, and sinusoidal ultrastructure was observed by transmission electron microscopy. Furthermore, the level of basement membrane proteins (collagen type

  12. Effectiveness of enterosgel usage in the conditions of simultaneous destruction of rats by karbofos and carbon tetrachloride

    Directory of Open Access Journals (Sweden)

    L. А. Boyko

    2014-10-01

    Full Text Available The aim of our study was to examine the effectiveness of the enterosgel sorbent in the terms of simultaneous destruction of rats by karbofos and carbon tetrachloride. Experiments were carried out on white rats weighing 175–200 g, which were kept on a standard diet. Karbofos was administered intragastrically on daily basis in the aqueous solution at the rate of 20 mg/kg of the body weight, which is 1/10 of the LD50. Carbon tetrachloride was administered intraperitoneally, twice a day in the form of a 50% oil solution at a dose of 1.0 ml/kg of animal. Animals received enterosgel daily by intragastric way at the rate of 120 mg/kg of body weight. The activity of free radical processes in rats was assessed by thiobarbituric acid content – active products (TBA-AP in serum, liver and heart homogenates. Level of endogenous intoxication was determined by the content of average weight molecules (AWM in serum and liver homogenate. The degree of cytolysis of hepatocytes was assessed by the activity of alanine and aspartate aminotransferase (AlAT, AsAT, alkaline phosphatase (ALP in serum, liver and heart homogenates. The degree of damage of the nervous system was studied by the activity of acetylcholinesterase (AChE in serum and liver homogenate. Content of TBA-AP in serum, liver and myocardium increased throughout the period of study. Reduction of TBA-AP was observed in studied tissues after applying of enterosgel sorbent in the affected body. After the defeat by toxicants we showed significant increase of fraction of AM1 (chain aminoacids dominate and AM2 (aromatic aminoacids dominate in serum and liver of experimental rats throughout the experiment. Enterosgel showed a positive effect on this index, reducing the content of MSM molecules. Due to toxic effects of endogenous and exogenous toxins in cells degradation and changing the permeability of plasma membranes of hepatocytes was observed as evidenced by the increased activity of both AlAT and As

  13. Phospholipid hydroperoxide accumulation in liver of rats intoxicated with carbon tetrachloride and its inhibition by dietary alpha-tocopherol.

    Science.gov (United States)

    Miyazawa, T; Suzuki, T; Fujimoto, K; Kaneda, T

    1990-05-01

    The formation and accumulation of phospholipid hydroperoxides, especially of phosphatidylcholine hydroperoxide (PCOOH), a primary peroxidation product of phosphatidylcholine (PC), in livers of carbon tetrachloride-intoxicated rats was investigated. PCOOH in liver and blood plasma was measured by a chemiluminescence-high-performance liquid chromatography procedure originally developed by Miyazawa et al. (Anal. Lett. 20, 915, 1987; Free Radical Biol. Med. 7, 209, 1989). Male Sprague-Dawley rats (120 g body wt., 5 weeks of age) were used in the experiments. The amount of PCOOH in the liver of control rats (CCl4-untreated) was 160 +/- 20 pmol/100 mg protein (mean +/- SD) and the PCOOH/PC molar ratio was 1.1 +/- 0.1 X 10(-5). In CCl4 (0.1 ml/100 g body wt.)-dosed rats, the liver PCOOH was 289 +/- 65 pmol/100 mg protein (PCOOH/PC = 2.4 +/- 0.4 X 10(-5], 764 +/- 271 pmol/100 mg protein (PCOOH/PC = 5.2 +/- 1.7 X 10(-5], and 856 +/- 165 pmol/100 mg protien (PCOOH/PC = 6.0 +/- 0.8 X 10(-5] at 6 h, 24 h, and 1 week after the dose, respectively. Under such conditions, the liver phosphatidylethanolamine hydroperoxide (PEOOH) level was not altered and the concentration was less than 100 pmol/100 mg protein even after the dose. The increments of liver PCOOH were suppressed 56% by the oral supplementation of DL-alpha-tocopherol (5 mg/100 g body wt./day) for a week before CCl4 administration. A relatively larger amount of PEOOH was found after stimulation of PC hydroperoxidation in the liver of rats with a large amount of CCl4 (0.25 ml/100 g body wt.) rather than with the small amount of CCl4 (0.1 ml/100 g body wt.).(ABSTRACT TRUNCATED AT 250 WORDS)

  14. In vivo gene transfer of endothelial nitric oxide synthase decreases portal pressure in anaesthetised carbon tetrachloride cirrhotic rats

    Science.gov (United States)

    Van de Casteele, M; Omasta, A; Janssens, S; Roskams, T; Desmet, V; Nevens, F; Fevery, J

    2002-01-01

    Background: Portal hypertension in cirrhosis results from enhanced intrahepatic resistance to an augmented inflow. The former is partly due to an imbalance between intrahepatic vasoconstriction and vasodilatation. Enhanced endothelin-1 and decreased activity of hepatic constitutive endothelial nitric oxide synthase (NOS 3) was reported in carbon tetrachloride (CCl4) cirrhotic rat liver. Aims: To study whether an increase in hepatic NOS 3 could be obtained in the CCl4 cirrhotic rat liver by in vivo cDNA transfer and to investigate a possible effect on portal pressure. Methods: Hepatic NOS 3 immunohistochemistry and western blotting were used to measure the amount of NOS 3 protein. Recombinant adenovirus, carrying cDNA encoding human NOS 3, was injected into the portal vein of CCl4 cirrhotic rats. Cirrhotic controls received carrier buffer, naked adenovirus, or adenovirus carrying the lac Z gene. Results: NOS 3 immunoreactivity and amount of protein (western blotting) were significantly decreased in CCl4 cirrhotic livers. Following cDNA transfer, NOS 3 expression and the amount of protein were partially restored. Portal pressure was 11.4 (1.6) mm Hg in untreated cirrhotic (n=9) and 11.8 (0.6) in lac Z transfected (n=4) cirrhotic rats but was reduced to 7.8 (1.0) mm Hg (n=9) five days after NOS 3 cDNA transfer. No changes were observed in systemic haemodynamics, in liver tests or urinary nitrates, or in NOS 3 expression in lung or kidney, indicating a highly selective transfer. Conclusions: NOS 3 cDNA transfer to cirrhotic rat liver is feasible and the increase in hepatic NOS 3 leads to a marked decrease in portal hypertension without systemic effects. These data indicate a major haemodynamic role of intrahepatic NOS 3 in the pathogenesis of portal hypertension in CCl4 cirrhosis. PMID:12171971

  15. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

    Directory of Open Access Journals (Sweden)

    X. Xiao

    2010-11-01

    Full Text Available Carbon tetrachloride (CCl4 has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CCl4 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996–2004. The Model of Atmospheric Transport and Chemistry (MATCH, driven by offline National Center for Environmental Prediction (NCEP reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE and the Earth System Research Laboratory (ESRL of the National Oceanic and Atmospheric Administration (NOAA and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions.

  16. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

    Directory of Open Access Journals (Sweden)

    X. Xiao

    2010-05-01

    Full Text Available Carbon tetrachloride (CCl4 has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CC14 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996–2004. The Model of Atmospheric Transport and Chemistry (MATCH, driven by offline National Center for Environmental Prediction (NCEP reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE and NOAA Earth System Research Laboratory (ESRL and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions.

  17. Hepatoprotective activity of methanolic leaves extract of Rostellularia procumbens by using carbon tetrachloride intoxicated rats

    Directory of Open Access Journals (Sweden)

    M. Mamatha

    2014-12-01

    Conclusion: The results confirm that R. procumbens have hepatoprotective activity against CCl4 induced hepatotoxicity and significant hepatoprotection seen at 500 mg/kg dose. [Int J Basic Clin Pharmacol 2014; 3(6.000: 964-969

  18. Subchronic inhalation of carbon tetrachloride alters the tissue retention of acutely inhaled plutonium-239 nitrate in F344 rats and syrian golden hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Benson, J.M.; Barr, E.B.; Lundgren, D.L. [and others

    1995-12-01

    Carbon tetrachloride (CCl{sub 4}) has been used extensively in the nuclear weapons industry, so it is likely that nuclear plant workers have been exposed to both CCl{sub 4} and plutonium compounds. Future exposures may occur during {open_quotes}cleanup{close_quotes} operations at weapons productions sites such as the Hanford, Washington, and Rocky Flats, Colorado, facilities. Inhalation of 20 and 100 ppm CCl{sub 4} by hamsters reduces uptake of {sup 239}Pu solubilized from lung, shunting the {sup 239}Pu to the skeleton.

  19. Improved Predictions of Carbon Tetrachloride Contaminant Flow and Transport: Implementation of Kinetic Volatilization and Multicomponent NAPL Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Martinus; Zhang, Z. F.; Freedman, Vicky L.; Tartakovsky, Guzel D.

    2008-09-29

    Carbon tetrachloride (CT) was discharged to waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. The RI/FS process and remedial investigations for the 200-PW-1, 200 PW-3, and 200-PW-6 Operable Units are described in the Plutonium/Organic-Rich Process Condensate/Process Waste Groups Operable Unit RI/FS Work Plan. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the STOMP simulator (White and Oostrom, 2006) by incorporating kinetic volatilization of nonaqueous phase liquids (NAPL) and multicomponent flow and transport. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy. Previous numerical simulation results with the STOMP simulator have overestimated the effect of soil vapor extraction (SVE) on subsurface CT, showing rapid removal of considerably more CT than has actually been recovered so far. These previous multiphase simulations modeled CT mass transfer between phases based on equilibrium partitioning. Equilibrium volatilization can overestimate volatilization because mass transfer limitations present in the field are not considered. Previous simulations were also conducted by modeling the NAPL as a single component, CT. In reality, however, the NAPL mixture disposed of at the Hanford site contained several non-volatile and nearly insoluble organic components, resulting in time-variant fluid properties as the CT component volatilized or dissolved over time. Simulation of CT removal from a DNAPL mixture using single-component DNAPL properties typically leads to an overestimation of CT removal. Other possible reasons for the discrepancy

  20. Potentiation of carbon tetrachloride hepatotoxicity and lethality in type 2 diabetic rats.

    Science.gov (United States)

    Sawant, Sharmilee P; Dnyanmote, Ankur V; Shankar, Kartik; Limaye, Pallavi B; Latendresse, John R; Mehendale, Harihara M

    2004-02-01

    There is a need for well characterized and economical type 2 diabetic model that mimics the human disease. We have developed a type 2 diabetes rat model that closely resembles the diabetic patients and takes only 24 days to develop robust diabetes. Nonlethal doses of allyl alcohol (35 mg/kg i.p.), CCl(4) (2 ml/kg i.p.), or thioacetamide (300 mg/kg i.p.) yielded 80 to 100% mortality in diabetic rats. The objective of the present study was to investigate two hypotheses: higher CCl(4) bioactivation and/or inhibited compensatory tissue repair were the underlying mechanisms for increased CCl(4) hepatotoxicity in diabetic rats. Diabetes was induced by feeding high fat diet followed by a single dose of streptozotocin on day 14 (45 mg/kg i.p.) and was confirmed on day 24 by hyperglycemia, normoinsulinemia, and oral glucose intolerance. Time course studies (0-96 h) of CCl(4) (2 ml/kg i.p.) indicated that although initial liver injury was the same in nondiabetic and diabetic rats, it progressed only in the latter, culminating in hepatic failure, and death. Hepatomicrosomal CYP2E1 protein and activity, lipid peroxidation, glutathione, and (14)CCl(4) covalent binding to liver tissue were the same in both groups, suggesting that higher bioactivation-based injury is not the mechanism. Inhibited tissue repair resulted in progression of injury and death in diabetic rats, whereas in the nondiabetic rats robust tissue repair resulted in regression of injury and survival after CCl(4) administration. These studies show high sensitivity of type 2 diabetes to model hepatotoxicants and suggest that CCl(4) hepatotoxicity is potentiated due to inhibited tissue repair. PMID:14610242

  1. Potentiation of carbon tetrachloride hepatotoxicity and lethality in type 2 diabetic rats.

    Science.gov (United States)

    Sawant, Sharmilee P; Dnyanmote, Ankur V; Shankar, Kartik; Limaye, Pallavi B; Latendresse, John R; Mehendale, Harihara M

    2004-02-01

    There is a need for well characterized and economical type 2 diabetic model that mimics the human disease. We have developed a type 2 diabetes rat model that closely resembles the diabetic patients and takes only 24 days to develop robust diabetes. Nonlethal doses of allyl alcohol (35 mg/kg i.p.), CCl(4) (2 ml/kg i.p.), or thioacetamide (300 mg/kg i.p.) yielded 80 to 100% mortality in diabetic rats. The objective of the present study was to investigate two hypotheses: higher CCl(4) bioactivation and/or inhibited compensatory tissue repair were the underlying mechanisms for increased CCl(4) hepatotoxicity in diabetic rats. Diabetes was induced by feeding high fat diet followed by a single dose of streptozotocin on day 14 (45 mg/kg i.p.) and was confirmed on day 24 by hyperglycemia, normoinsulinemia, and oral glucose intolerance. Time course studies (0-96 h) of CCl(4) (2 ml/kg i.p.) indicated that although initial liver injury was the same in nondiabetic and diabetic rats, it progressed only in the latter, culminating in hepatic failure, and death. Hepatomicrosomal CYP2E1 protein and activity, lipid peroxidation, glutathione, and (14)CCl(4) covalent binding to liver tissue were the same in both groups, suggesting that higher bioactivation-based injury is not the mechanism. Inhibited tissue repair resulted in progression of injury and death in diabetic rats, whereas in the nondiabetic rats robust tissue repair resulted in regression of injury and survival after CCl(4) administration. These studies show high sensitivity of type 2 diabetes to model hepatotoxicants and suggest that CCl(4) hepatotoxicity is potentiated due to inhibited tissue repair.

  2. PROTECTIVE ABILITY OF MOMORDICA CHARANTIA L AGAINST CCL4 INDUCED HEPATIC DAMAGE IN RATS

    OpenAIRE

    Pingale Shirish S

    2010-01-01

    The aim of this study is to evaluate the efficacy of Momordica charantia on the experimental hepatotoxicity induced by carbon tetrachloride (CCl4). Carbon tetrachloride was administered once and simultaneously suspension of dry fruit powder was prepared in aqueous medium and was daily administered at a dose level of 1mg/kg body weight for 4 days. Silymarin was used as a standard drug for this study. Administration of carbon tetrachloride showed significant changes in the levels of serum amino...

  3. Use of 13C Labeled Carbon Tetrachloride to Demonstrate the Transformation to Carbon Dioxide under Anaerobic Conditions in a Continuous Flow Column

    Science.gov (United States)

    Semprini, L.; Azizian, M.

    2012-12-01

    The demonstration of transformation of chlorinated aliphatic compounds (CAHs) in the subsurface is a challenge, especially when the products are carbon dioxide (CO2) and chloride ion. The groundwater contaminant carbon tetrachloride (CT) is of particular interest since a broad range of transformation products can be potentially formed under anaerobic conditions. The ability to demonstrate the transformation of CT to CO2 as a non toxic endproduct, is also of great interest. Results will be presented from a continuous flow column study where 13C labeled CT was used to demonstrate its transformation to CO2. The column was packed with a quartz sand and bioaugmented the Evanite Culture (EV) that is capable of transforming tetrachloroethene (PCE) to ethene. The column was continously fed a synthetic groundwater that was amended with PCE (0.10 mM) and either formate (1.5 mM) or lactate (1.1 mM), which ferments to produce hydrogen (H2) as the ultimate electron donor. Earlier CT transformation studies with the column, in the absence of sulfate reduction, and with formate added as a donor found CT (0.015 mM) was over 98% transformed with about 20% converted to chloroform (CF) (0.003 mM) and with a transient detection of chloromethane (CM). Methane and carbon disulfide, as potential products, were not detected. Neither CT nor CF inhibited the reductive dehalogenation of PCE to ethene. A series of transient studies conducted after these initial CT transformation tests, but in the absence of CT, showed formate remained an effective substrate for maintaining sulfate reduction and PCE transformation. Lactate, which was effectively fermented prior to CT addition, was not effectively fermented, with propionate accumulating as a fermentation product. When lactate was added, PCE was mainly transformed to cis-dichloroethene (cis-DCE) and VC, and sulfate reduction did not occur. In order to restore effective lactate fermentation the column was then bioaugmented with an EV culture that

  4. 典型场地四氯化碳污染的健康风险评价%A typical carbon tetrachloride contaminated site and health risk assessment

    Institute of Scientific and Technical Information of China (English)

    张新钰; 王晓红; 辛宝东; 叶超; 郭高轩

    2011-01-01

    以华北某污染场地为研究区域,采集了场地内大气、土壤、地表水和地下水4个类别共196个样品.分析了25项挥发性有机物在不同区域的分布特征,探讨了超标污染物的污染来源,最后,应用美国环保局的健康风险评价方法,对场地超标污染物进行了健康风险评价.结果表明,场地超标污染物仅为四氯化碳;主要赋存于地下水中,其污染晕的平面分布与地下水流向显著相关,垂向分布与深度相关;四氯化碳致癌危害程度总体表现为饮水途径〉洗浴呼吸吸入途径〉洗浴皮肤接触途径,其中饮水暴露途径致癌危害指数最大达到了3.03×10-5,超出了可接受的风险水平,由此将导致每百万人30.3个癌症患者的可能,村民长期以目前水井作为主要的水源,身体健康将受到严重影响;洗浴呼吸吸入途径和皮肤接触途径的致癌危害指数在(10-10~10-7)范围,在可接受风险水平之内.四氯化碳非致癌危害指数均小于1,风险较低.%This study was focused on characterization of organic pollutants in a typical site of north China.A total of 196 samples,including soil,air,surface water and groundwater,were collected from the site.Based on the analysis results,the distribution characteristics and possible sources of 25 volatile organics at various regions were analyzed.The health risk assessment standard of the US Environmental Protection Agency was applied to assess the health risk of the pollutants in the site.The results showed that carbon tetrachloride was the only non-attainment pollutant and mainly distributed in the groundwater.The horizontal distribution of the pollution plume was highly related with the direction of the groundwater flow and the vertical distribution was affected fairly by the samples' depth.The largest carcinogenic potentials of the carbon tetrachloride were known to be from drinking water,with the carcinogenic index value of 3.03×10-5.It exceeded the

  5. 四氯化碳液相催化加氢反应动力学的研究%KINETIC STUDIES ON THE CATALYTIC HYDROGENATION OF CARBON TETRACHLORIDE TO CHLOROFORM IN LIQUID PHASE

    Institute of Scientific and Technical Information of China (English)

    毛建新; 蒋晓原; 陆维敏; 郑小明

    2001-01-01

    Carbon tetrachloride is an ozone-depleting chemical, while chloroform is not. Therefore it is important for the catalytic hydrodechlorination of CCl4 to CHCl3. In this paper, kinetics on the catalytic hydrogenation of carbon tetrachloride to chloroform in liquid phase was studied. A reaction mechanism was proposed. Hydrogen molecular was activated on the surface of catalyst, the activated hydrogen atom then reacted with CCl4 in the solution and produced CHCl3. A definite kinetic equation could be deduced from the reaction mechanism. The reaction rate constant is concerned with the intial concentration of CCl4 in the solution, pressure, reaction temperature and the concentration of active center. All these factors were investigated over Pt-Pd/C catalyst and fit in with the kinetic equation. The activation energy of the reaction is 86?KJ/mol according to the experimental results.

  6. COMPORTAMENTO DA GLICOSE E DAS MUCOPROTEÍNAS EM BOVINOS INTOXICADOS EXPERIMENTALMENTE PELO TETRACLORETO DE CARBONO GLUCOSE AND MUCOPROTEIN BEHAVIOR IN BOVINES EXPERIMENTALLY INTOXICATED BY CARBON TETRACHLORIDE

    Directory of Open Access Journals (Sweden)

    Eduardo Cavalheiro Jardim

    2007-09-01

    Full Text Available

    Para o presente experimento foram utilizados cinco bovinos, azebuados, machos, de 16 a 18 meses de idade, com o peso corporal variando de 95 a 150 quilos e clinicamente sadios, que foram alojados em baias individuais, recebendo cada um deles diariamente gramíneas trituradas “ad libtum” e um quilo de ração de mantença. Os animais foram dosificados com tetracloreto de carbono diluído a 50% em óleo de milho, recebendo em cada dose (ml/k.p.v.: 0,1; 0,3; 0,5; 0,7 e 0,9, respectivamente para os animais de I a V, administrado por punção intraruminal na fossa paralombar esquerda, com o animal mantido em decúbito lateral direito. A pesquisa foi realizada durante 61 dias, sendo colhidas cinqüenta amostras de sangue por punção da jugular. Foram analisados, através da colorimetria, os níveis séricos de glicose e das mucoproteínas. Foram colhidas e analisadas amostras hepáticas.

    For the present experiment it was used five crossbred zebu steer from 16 to 18 months old with weight varying from 95 to 150 kilograms and all clinically healthy. They were stabled in individual stalls, receiving daily chopped forage “ad libtum” and one Kilogram of balanced maintenance ration. The animals were dosed with carbon tetrachloride diluted at 50 % in corn oil, each animal from I to V respectively receiving a dose (ml/p/lw: 0.1; 0.3; 0.5; 0.7 and 0.9. The carbon tetrachloride was administered by intraruminal puncture in the left flank. The duration of the trial was 61 days. Fifty blood samples were collected from the jugular vein. The serum levels of glucose and mucoproteins were analyzed by photocolorimeter. Hepatic samples were also collected and analysed.

  7. UV absorption cross sections of nitrous oxide (N2O and carbon tetrachloride (CCl4 between 210 and 350 K and the atmospheric implications

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2010-07-01

    Full Text Available Absorption cross sections of nitrous oxide (N2O and carbon tetrachloride (CCl4 are reported at five atomic UV lines (184.95, 202.548, 206.200, 213.857, and 228.8 nm at temperatures in the range 210–350 K. In addition, UV absorption spectra of CCl4 are reported between 200–235 nm as a function of temperature (225–350 K. The results from this work are critically compared with results from earlier studies. For N2O, the present results are in good agreement with the current JPL recommendation enabling a reduction in the estimated uncertainty in the N2O atmospheric photolysis rate. For CCl4, the present cross section results are systematically greater than the current recommendation at the reduced temperatures most relevant to stratospheric photolysis. The new cross sections result in a 5–7% increase in the modeled CCl4 photolysis loss, and a slight decrease in the stratospheric lifetime, from 51 to 50 years, for present day conditions. The corresponding changes in modeled inorganic chlorine and ozone in the stratosphere are quite small. A CCl4 cross section parameterization for use in atmospheric model calculations is presented.

  8. UV absorption cross sections of nitrous oxide (N2O and carbon tetrachloride (CCl4 between 210 and 350 K and the atmospheric implications

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2010-04-01

    Full Text Available Absorption cross sections of nitrous oxide (N2O and carbon tetrachloride (CCl4 are reported at five atomic UV lines (184.95, 202.548, 206.200, 213.857, and 228.8 nm at temperatures in the range 210–350 K. In addition, UV absorption spectra of CCl4 are reported between 200–235 nm as a function of temperature (225–350 K. The results from this work are critically compared with results from earlier studies. For N2O, the present results are in good agreement with the current JPL recommendation enabling a reduction in the estimated uncertainty in the N2O atmospheric photolysis rate. For CCl4, the present cross section results are systematically greater than the current recommendation at the reduced temperatures most relevant to stratospheric photolysis. The new cross sections result in a 5–7% increase in the modeled CCl4 photolysis loss, and a slight decrease in the stratospheric lifetime, from 51 to 50 years, for present day conditions. The corresponding changes in modeled inorganic chlorine and ozone in the stratosphere are quite small. A CCl4 cross section parameterization for use in atmospheric model calculations is presented.

  9. Antioxidant, hepatoprotective and hypolipidemic effects of methanolic root extract of Cassia singueana in rats following acute and chronic carbon tetrachloride intoxication

    Institute of Scientific and Technical Information of China (English)

    Ottu OJ; Atawodi SE; Onyike E

    2013-01-01

    Objective: To evaluate in vivo antioxidant and hepatoprotective activities of the methanolic extract of the root of Cassia singueana in rats following acute and chronic carbon tetrachloride intoxication. Methods: Malondialdehyde (MDA), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and bilirubin as indices of liver damage and lipid peroxidation were detected in rats after intraperitoneal administration of extract (5 mg/kg). Results: The liver, kidney and heart showed significant reduction (P<0.05) in the levels of MDA from (0.18±0.04), (0.23±0.07) and (0.26±0.10) nmol/mg respectively in the CCl4 control to (0.15±0.03), (0.17±0.04) and (0.17±0.07) nmol/mg protein in groups pre-treated with the extract for three days at 5 mg/kg). Similarly, compared to the CCl4 control, significant reduction (P<0.05) in serum AST, ALT and bilirubin as well as in level of total cholesterol and MDA with concomitant increase in HDL cholesterol, superoxide dismutase and catalase levels when CCl4-intoxicated rats were treated with Cassia singueana root extract for two weeks. Conclusions:These results suggest that methanolic extract of Cassia singueana contain potent antioxidant compounds that can offer significant protection against hepatic and oxidative injuries.

  10. Atmospheric carbon tetrachloride in rural background and industry surrounded urban areas in Northern Iberian Peninsula: Mixing ratios, trends, and potential sources.

    Science.gov (United States)

    de Blas, Maite; Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen; Navazo, Marino; Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley

    2016-08-15

    Latest investigations on atmospheric carbon tetrachloride (CTC) are focused on its ozone depleting potential, adverse effects on the human health, and radiative efficiency and Global Warming Potential as a greenhouse gas. CTC mixing ratios have been thoroughly studied since its restriction under the Montreal Protocol, mostly in remote areas with the aim of reporting long-term trends after its banning. The observed decrease of the CTC background mixing ratio, however, was not as strong as expected. In order to explain this behavior CTC lifetime should be adjusted by estimating the relative significance of its sinks and by identifying ongoing potential sources. Looking for possible sources, CTC was measured with high-time resolution in two sites in Northern Spain, using auto-GC systems and specifically developed acquisition and processing methodologies. The first site, Bilbao, is an urban area influenced by the surrounding industry, where measurements were performed with GC-MSD for a one-year period (2007-2008). The second site, at Valderejo Natural Park (VNP), is a rural background area where measurements were carried out with GC-FID and covering CTC data a nonsuccessive five-year period (2003-2005, 2010-2011, and 2014-2015years). Median yearly CTC mixing ratios were slightly higher in the urban area (120pptv) than in VNP (80-100pptv). CTC was reported to be well mixed in the atmosphere and no sources were noticed to impact the rural site. The observed long-term trend in VNP was in agreement with the estimated global CTC emissions. In the urban site, apart from industrial and commercial CTC sources, chlorine-bleach products used as cleaning agents were reported as promotors of indoor sources. PMID:27092418

  11. Non-covalent C-Cl…π interaction in acetylene-carbon tetrachloride adducts: Matrix isolation infrared and ab initio computational studies

    Science.gov (United States)

    Ramanathan, N.; Sundararajan, K.; Vidya, K.; Jemmis, Eluvathingal D.

    2016-03-01

    Non-covalent halogen-bonding interactions between π cloud of acetylene (C2H2) and chlorine atom of carbon tetrachloride (CCl4) have been investigated using matrix isolation infrared spectroscopy and quantum chemical computations. The structure and the energies of the 1:1 C2H2-CCl4 adducts were computed at the B3LYP, MP2 and M05-2X levels of theory using 6-311 ++G(d,p) basis set. The computations indicated two minima for the 1:1 C2H2-CCl4 adducts; with the C-Cl…π adduct being the global minimum, where π cloud of C2H2 is the electron donor. The second minimum corresponded to a C-H…Cl adduct, in which C2H2 is the proton donor. The interaction energies for the adducts A and B were found to be nearly identical. Experimentally, both C-Cl…π and C-H…Cl adducts were generated in Ar and N2 matrixes and characterized using infrared spectroscopy. This is the first report on halogen bonded adduct, stabilized through C-Cl…π interaction being identified at low temperatures using matrix isolation infrared spectroscopy. Atoms in Molecules (AIM) and Natural Bond Orbital (NBO) analyses were performed to support the experimental results. The structures of 2:1 ((C2H2)2-CCl4) and 1:2 (C2H2-(CCl4)2) multimers and their identification in the low temperature matrixes were also discussed.

  12. 通风速率对土壤中四氯化碳污染物去除效率的影响研究%Effects of Airflow Velocity on the Removal Efficiency of Carbon Tetrachloride from Polluted Soil

    Institute of Scientific and Technical Information of China (English)

    卢中华; 裴宗平; 鹿守敢; 王岩; 胡佳佳

    2011-01-01

    某重要岩溶地下水源地受到四氯化碳的严重污染,为此采用上柱通风试验模拟土壤气相抽提(SVE)净化四氯化碳污染物的过程,对通风速率为40 mL·min-1和70 mL·min-1两种条件下土壤四氯化碳的去除过程进行了主试验模拟研究,,结果表明,土柱通风能有效太除土壤中的四氯化碳污染物,通风条件下土壤中四氯化碳的去除过程符合一级反应动力学,土壤中四氯化碳浓度C的对数值In[C/(μg·L-1)]与时间t呈良好的线性关系,相关系数均在0.95以上.通风速率为40 mL·min-1的土柱A各取样口四氯化碳去除反应速率常数k值在0.013 2~0.015 5 h-1之间,通风速率为70 mL· min-1的土柱B各取样口k值在0.017 8~0.022 2 h-1之间,说明增大通风速率能提高土壤中四氯化碳污染物的去除效率.%A main Karst groundwater supply source in North China was polluted by carbon tetrachloride. Researches at home and abroad proved that soil vapor extraction( SVE ) was an effective in-situ remediation technology for groundwater pollution. In this paper, two soil columns of pilot scale were designed to Simulate the SVE process and study the removal of carbon tetrachloride from soil. The airflow velocities of two soil columns were 70 mL per minute and 40 mL per minute respectively. The experimental results showed that the carbon tetrachloride could be effectively removed by ventilation. The removal of carbon tetrachloride in soil followed the first order reaction kinetics.There was a good linear relationship between the logarithm of the concentration of carbon tetrachloride and time, and the correlation coefficients were all above 0.95. The reaction rate constant k of column A with venting velocity of 40 mL per minute was between 0.013 2 h-1 to 0.015 5 h-1, and the reaction rate constant k of column B with venting velocity of 70 mL per minute was between 0.017 8 h-1 to 0.022 2 h-1.The reaction rate constant of column B was greater than

  13. Evaluation of Antioxidant and Hepatoprotective Activities of Moringa oleifera Lam. Leaves in Carbon Tetrachloride-Intoxicated Rats

    OpenAIRE

    Dharmendra Singh; Priya Vrat Arya; Ved Prakash Aggarwal; Radhey Shyam Gupta

    2014-01-01

    The antioxidant and hepatoprotective activities of the extract of Moringa oleifera leaves were investigated against CCl4-induced hepatotoxicity in rats. Hepatotoxic rats were treated with ethanol extract of Moringa oleifera for a period of 60 days at the following three dose levels; 100, 200 and 400 mg/kg body weight/day, orally. The activities were studied by assaying the serum marker enzymes like SGOT, SGPT, GGT, LDH, ALP, ACP, as well as total bilirubin, total protein and albumin in serum ...

  14. Moderate (2%, v/v) Ethanol Feeding Alters Hepatic Wound Healing after Acute Carbon Tetrachloride Exposure in Mice.

    Science.gov (United States)

    Deshpande, Krutika T; Liu, Shinlan; McCracken, Jennifer M; Jiang, Lu; Gaw, Ta Ehpaw; Kaydo, Lindsey N; Richard, Zachary C; O'Neil, Maura F; Pritchard, Michele T

    2016-01-06

    Wound healing consists of three overlapping phases: inflammation, proliferation, and matrix synthesis and remodeling. Prolonged alcohol abuse can cause liver fibrosis due to deregulated matrix remodeling. Previous studies demonstrated that moderate ethanol feeding enhances liver fibrogenic markers and frank fibrosis independent of differences in CCl₄-induced liver injury. Our objective was to determine whether or not other phases of the hepatic wound healing response were affected by moderate ethanol after CCl₄ exposure. Mice were fed moderate ethanol (2% v/v) for two days and then were exposed to CCl₄ and euthanized 24-96 h later. Liver injury was not different between pair- and ethanol-fed mice; however, removal of necrotic tissue was delayed after CCl₄-induced liver injury in ethanol-fed mice. Inflammation, measured by TNFα mRNA and protein and hepatic Ly6c transcript accumulation, was reduced and associated with enhanced hepatocyte apoptosis after ethanol feeding. Hepatocytes entered the cell cycle equivalently in pair- and ethanol-fed mice after CCl₄ exposure, but hepatocyte proliferation was prolonged in livers from ethanol-fed mice. CCl₄-induced hepatic stellate cell activation was increased and matrix remodeling was prolonged in ethanol-fed mice compared to controls. Taken together, moderate ethanol affected each phase of the wound healing response to CCl₄. These data highlight previously unknown effects of moderate ethanol exposure on hepatic wound healing after acute hepatotoxicant exposure.

  15. Role of biotransformation in the activation of rat hepatic phospholipase C by carbon tetrachloride and related haloalkanes

    International Nuclear Information System (INIS)

    CCl4 exerts its hepatotoxicity through a reactive metabolite. Phospholipid degradation has been proposed as a mechanism by which CCl4-induced alterations at the endoplasmic reticulum result in damage to organelles distant from it. Activation of the hepatic phospholipid degradative enzyme phospholipase C (PLC) occurs rapidly after CCl4 exposure, yet the role of CCl4 metabolites in this activation has been uncertain. 1000 g rat hepatocellular fractions exposed to CCl4 exhibited time- and concentration-dependent increases in the conversion of membrane bound 14C-phosphatic acid into 14C-neutral lipid when 14C-glycerol-3-phosphate was incubated with the fraction in the presence of Ca2+, CoA, ATP, and palmitate. CCl4-induced PLC activation in the presence of NADPH (when CCl4 metabolism occurred) was 2-3 fold greater than in its absence at CCl4 concentrations below 1 mM. The metabolism-dependent activation occurred subsequent to the plateau of CCl4 metabolism, and was inhibited by metyrapone,whereas the metabolism-independent component was not

  16. Hepatoprotective activity of Leptadenia reticulata stems against carbon tetrachloride-induced hepatotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Amit Kumar Nema

    2011-01-01

    Conclusion: The ethanolic and aqueous extracts of stems of L. reticulata showed significant hepatoprotective activity. The ethanolic extract is more potent in hepatoprotection in CCl 4 -indiced liver injury model as compared with aqueous extract.

  17. Protection by pantethine, pantothenic acid and cystamine against carbon tetrachloride-induced hepatotoxicity in the rat.

    Science.gov (United States)

    Nagiel-Ostaszewski, I; Lau-Cam, C A

    1990-02-01

    The daily ip administration of pantethine (500 mg/kg), pantothenic acid (100 mg/kg) or cystamine (50 mg/kg) for 5 days conferred significant protection against the hepatotoxic and peroxidative actions of a 0.5 mL/kg ip dose of CCl4 in rats. All three treatments lessened the increases in serum ALT and liver TBARS values, and the reductions in serum triglyceride levels, and prevented the development of hepatic steatosis caused by the halocarbon. Pantethine was found to offer the greatest protection. PMID:2333416

  18. Renal effects of inhaled carbon tetrachloride and the influence of inhaled isopropanol: a comparison with the hepatic effects

    Energy Technology Data Exchange (ETDEWEB)

    Henry, E.C.

    1979-01-01

    These experiments suggest that direct interaction of CC1/sub 4/ in the kidney leading to a toxic response via the peroxidative mechanism proposed for its hepatotoxicity probably does not occur in rats and mice. Although the kidney does contain lipid peroxidizable in vitro, renal metabolism of CC1/sub 4/ initiating membrane lipid peroxidation as monitored by loss G-6-Pase activity cannot be detected in vivo following exposures which cause severe peroxidation in liver. Like liver, kidney tissue contains P-450 activity which is inducible and other data in the literature indicate its possible importance in mediating renal toxicity of some agents. However, the results of our experiments are more consistent with the hypothesis that renal effects of CC1/sub 4/ are secondary to the more severe response in liver.

  19. 水中三氯甲烷、四氯化碳的QHSS -40自动进样顶空气相色谱测定法%Determination of chloroform and carbon tetrachloride in water by automatic headspace gas chromatography

    Institute of Scientific and Technical Information of China (English)

    罗黎明

    2012-01-01

    目的 建立测定水中三氯甲烷和四氯化碳含量的全自动顶空气相色谱法.方法 利用全自动顶空进样技术,采用ECD检测器测定水中三氯甲烷和四氯化碳.结果 在测定条件下,方法的检出限三氯甲烷为0.06 μg/L,四氯化碳为0.03μg/L;三氯甲烷的RSD为1.7% ~2.5%,四氯化碳的RSD为1.5~2.8%;回收率三氯甲烷为101%~103%,四氯化碳为99.6% ~ 102%.结论 该方法简便、快速、具有较好的精密度与准确度,适用于水中三氯甲烷、四氯化碳测定.%[ Objective] To establish the method for determination of chloroform and carbon tetrachloride in water by automatic head-space gas chromatography. [ Methods ] Automated headspace sampling technology was adopted to detect chloroform and carbon tetrachloride in drinking water with ECD detector. [Results] Under the determination conditions, the detection limit was 0.03μg / L of chloroform and 0.06 μg/ L of carbon tetrachloride; RSD of chloroform and carbon tetrachloride was 1.7-2.5% andl.5-2. 8% , respectively; recoveries of chloroform and carbon tetrachloride were 101%-103% and 99. 6% ~ 102% , respectively. [ Conclusion] This method is simple, rapid, with good precision and accuracy, and suitable for determination of chloroform and carbon tetrachloride in drinking water.

  20. Evaluation of Antioxidant and Hepatoprotective Activities of Moringa oleifera Lam. Leaves in Carbon Tetrachloride-Intoxicated Rats.

    Science.gov (United States)

    Singh, Dharmendra; Arya, Priya Vrat; Aggarwal, Ved Prakash; Gupta, Radhey Shyam

    2014-01-01

    The antioxidant and hepatoprotective activities of the extract of Moringa oleifera leaves were investigated against CCl₄-induced hepatotoxicity in rats. Hepatotoxic rats were treated with ethanol extract of Moringa oleifera for a period of 60 days at the following three dose levels; 100, 200 and 400 mg/kg body weight/day, orally. The activities were studied by assaying the serum marker enzymes like SGOT, SGPT, GGT, LDH, ALP, ACP, as well as total bilirubin, total protein and albumin in serum concomitantly with the activities of LPO, SOD, CAT, GSH, GR and GPx in liver. The activities of all parameters registered a significant (p ≤ 0.001) alteration in CCl₄ treated rats, which were significantly recovered towards an almost normal level in rats co-administered with M. oleifera extract in a dose-dependent manner. All the biochemical investigations were confirmed by the histopathological observations and compared with the standard drug. silymarin. Results suggest that the antioxidant and hepatoprotective activities of M. oleifera leaves are possibly related to the free radical scavenging activity which might be due to the presence of total phenolics and flavonoids in the extract and/or the purified compounds β-sitosterol, quercetin and kaempferol, which were isolated from the ethanol extract of M. oleifera leaves. PMID:26785072

  1. Protective Effects of Quercetin and Quercetin-5',8-Disulfonate against Carbon Tetrachloride-Caused Oxidative Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Yanmang Cui

    2013-12-01

    Full Text Available Oxidative stress is one of the major factors in the pathogenesis of liver disease. Quercetin is a plant-based antioxidant traditionally used as a treatment for hepatic injury, but its poor solubility affects its bioavailability. We here report the regulative effects on hepatoprotection and absorption in mice of quercetin sulfation to form quercetin-5',8-disulfonate (QS, a novel synthetic compound. Oral administration of both QS and the parent quercetin at 100, 200 and 500 mg/kg·bw prior to acute CCl4 oxidative damage in mice, effectively attenuated serum alanine aminotransferase (ALT, aspartate aminotransferase (AST and lactate dehydrogenase (LDH activities and hepatic malondialdehyde (MDA levels (p < 0.05, and suppressed the CCl4-induced depletion of glutathione peroxidase (GSH-Px and total superoxide dismutase (T-SOD. Selective 5',8-sulfation of quercetin increased the hepatoprotective effect, and its relative absorption relative to quercetin (p < 0.05 as indicated by an improved 24-hour urinary excretion and a decreased fecal excretion determined by HPLC. These results and histopathological observations collectively demonstrate that quercetin sulfation increases its hepatoprotective effects and absorption in mice, and QS has potential as a chemopreventive and chemotherapeutic agent for liver diseases.

  2. Evaluation of Antioxidant and Hepatoprotective Activities of Moringa oleifera Lam. Leaves in Carbon Tetrachloride-Intoxicated Rats

    Directory of Open Access Journals (Sweden)

    Dharmendra Singh

    2014-09-01

    Full Text Available The antioxidant and hepatoprotective activities of the extract of Moringa oleifera leaves were investigated against CCl4-induced hepatotoxicity in rats. Hepatotoxic rats were treated with ethanol extract of Moringa oleifera for a period of 60 days at the following three dose levels; 100, 200 and 400 mg/kg body weight/day, orally. The activities were studied by assaying the serum marker enzymes like SGOT, SGPT, GGT, LDH, ALP, ACP, as well as total bilirubin, total protein and albumin in serum concomitantly with the activities of LPO, SOD, CAT, GSH, GR and GPx in liver. The activities of all parameters registered a significant (p ≤ 0.001 alteration in CCl4 treated rats, which were significantly recovered towards an almost normal level in rats co-administered with M. oleifera extract in a dose-dependent manner. All the biochemical investigations were confirmed by the histopathological observations and compared with the standard drug. silymarin. Results suggest that the antioxidant and hepatoprotective activities of M. oleifera leaves are possibly related to the free radical scavenging activity which might be due to the presence of total phenolics and flavonoids in the extract and/or the purified compounds β-sitosterol, quercetin and kaempferol, which were isolated from the ethanol extract of M. oleifera leaves.

  3. Evaluation of Antioxidant and Hepatoprotective Activities of Moringa oleifera Lam. Leaves in Carbon Tetrachloride-Intoxicated Rats

    Science.gov (United States)

    Singh, Dharmendra; Arya, Priya Vrat; Aggarwal, Ved Prakash; Gupta, Radhey Shyam

    2014-01-01

    The antioxidant and hepatoprotective activities of the extract of Moringa oleifera leaves were investigated against CCl4-induced hepatotoxicity in rats. Hepatotoxic rats were treated with ethanol extract of Moringa oleifera for a period of 60 days at the following three dose levels; 100, 200 and 400 mg/kg body weight/day, orally. The activities were studied by assaying the serum marker enzymes like SGOT, SGPT, GGT, LDH, ALP, ACP, as well as total bilirubin, total protein and albumin in serum concomitantly with the activities of LPO, SOD, CAT, GSH, GR and GPx in liver. The activities of all parameters registered a significant (p ≤ 0.001) alteration in CCl4 treated rats, which were significantly recovered towards an almost normal level in rats co-administered with M. oleifera extract in a dose-dependent manner. All the biochemical investigations were confirmed by the histopathological observations and compared with the standard drug. silymarin. Results suggest that the antioxidant and hepatoprotective activities of M. oleifera leaves are possibly related to the free radical scavenging activity which might be due to the presence of total phenolics and flavonoids in the extract and/or the purified compounds β-sitosterol, quercetin and kaempferol, which were isolated from the ethanol extract of M. oleifera leaves. PMID:26785072

  4. THE USE OF VAPOR EXTRACTION SYSTEM AND ITS SUBSEQUENT REDUCTION OF WORKER EXPOSURE TO CARBON TETRACHLORIDE DURING RETRIEVAL OF HANFORDS LEGACY WASTE

    Energy Technology Data Exchange (ETDEWEB)

    PITTS DA

    2008-03-18

    The Hanford Site is a decommissioned nuclear productions complex located in south eastern Washington and is operated by the Department of Energy (DOE). From 1955 to 1973, carbon tetrachloride (CCl{sub 4}), used in mixtures with other organic compounds, was used to recover plutonium from aqueous streams at Z Plant located on the Hanford Site. The aqueous and organic liquid waste that remained at the end of this process was discharged to soil columns in waste cribs located near Z Plant. Included in this waste slurry along with CCl{sub 4} were tributyl phosphate, dibutyl butyl phosphate, and lard oil. (Truex et al., 2001). In the mid 1980's, CCl{sub 4} was found in the unconfined aquifer below the 200 West Area and subsequent ground water monitoring indicated that the plume was widespread and that the concentrations were increasing. It has been estimated that approximately 750,000 kg (826.7 tons) of CCl{sub 4} was discharged to the soil from 1955 to 1973. (Truex et al., 2001). With initial concentration readings of approximately 30,000 parts per million by volume (ppmv) in one well field alone, soil vapor extraction began in 1992 in an effort to remove the CCl{sub 4} from the soil. (Rohay, 1999). Since 1992, approximately 78,607.6 kg (86.65 tons) of CCl{sub 4} have been extracted from the soil through the process of soil vapor extraction and 9,409.8 kg (10.37 tons) have been removed from the groundwater. (EPA, 2006). The success of this environmental cleanup process benefited not only the environment but also workers who were later involved in the retrieval of solid waste from trenches that were in or near the CCl{sub 4} plume. Solid waste was buried in trenches near Z Plant from 1967 to 1990. The solid waste, some of which was chemically and/or radioactively contaminated, was buried in trenches in steel or fiber drums, fiberboard boxes, fiberglass-reinforced plywood boxes, and steel, concrete, or wooden boxes. Much of this waste was buried with the intention of

  5. Comparative study of the pharmacokinetics of carbon tetrachloride in the rat following repeated inhalation exposures of 8 and 11.5 hr/day

    International Nuclear Information System (INIS)

    To evaluate whether exposure to inhaled vapors for periods longer than 8 hr/day could affect the rates and routes of elimination, male Sprague-Dawley rats were repeatedly exposed to 100 ppm of radiolabeled carbon tetrachloride (14CCl4) in a closed-loop chamber. One group was exposed for 8 hr/day for 5 days and another group for 11.5 hr/day for 4 days. Two other groups were exposed for either 8 hr/day for 10 of 12 consecutive days or 11.5 hr/day for 7 of 10 days. The elimination of 14C activity was measured in the expired air, urine, and feces for up to 100 hr following exposure and the pharmacokinetic parameters were determined. Following 2 weeks of exposure to the 8-hr/day schedule, 14CCl4 in the breath and 14C activity in the feces comprised 45 and 48% of the total 14C excreted, respectively. Following 2 weeks of exposure to the 11.5-hr/day schedule, the values were 32 and 62%, respectively, indicating that repeated exposure to the longer schedule altered the route of elimination of CCl4. Regardless of the period of exposure, less than 8% of the inhaled 14CCl4 was excreted in the urine and less than 2% was exhaled in the breath as the 14CO2 metabolite. Approximately 97-98% of the 14C activity in the expired air was 14CCl4. The quantities of 14C noted in the feces and urine suggest that more than 60% of the inhaled CCl4 was metabolized. Elimination of 14CCl4 and 14CO2 in the breath followed a two-compartment, first-order pharmacokinetic model (r2 = 0.98). For rats exposed 8 hr/day and 11.5 hr/day for 2 weeks, the average half-lives for elimination of 14CCl4 in the breath for the fast (alpha) and slow (beta) phases averaged 96 and 455 min, and 89 and 568 min, respectively. The average alpha and beta half-lives for elimination of 14CO2 in the breath

  6. 四氯化碳过程助剂及其替代技术的应用与发展现状%Carbon tetrachloride as a process agent,and application and current development situation of its substitute technology

    Institute of Scientific and Technical Information of China (English)

    李春喜; 汪文川; 杨礼荣; 刘援; 王淑燕

    2000-01-01

    简要介绍了破坏臭物质的主要品种、用途和国家淘汰计划,着重介绍了四氯化碳在过程助剂领域中的主要用途、用量以及替代技术的开发现状和趋势,指出了研究四氯化碳转化技术的紧迫性、重要性和选择转化反应需要考虑的因素。%The main species,uses and phaseout programof ozone depleting substances are described briefly.The main uses and consumption of carbon tetrachloride are introduced emphatically as well as the current development situation and trend of its substitute technology.The urgency,importance and factors needing to be considered in the development of carbon tetrachloride substitute technology are pointed out.

  7. A Continuous Flow Column Study of the Anaerobic Transformation of a CAH Mixture of Tetrachloroethene and Carbon Tetrachloride Using Formate as an Electron Donor

    Science.gov (United States)

    Semprini, L.; Azizian, M. F.; Kim, Y.

    2011-12-01

    Many groundwater sites are contaminated with mixtures of chlorinated aliphatic hydrocarbons (CAHs) that represent a challenge when biological remediation processes are being considered. This is especially challenging when high concentrations of CAHs are present.Trichloromethane (CF), for example, has been observed to inhibit and potentially exert toxicity on reductive dehalogenation of tetrachloroethene (PCE) and trichloroethene (TCE). Results will be presented from a continuous flow column study where the simultaneous transformation of PCE and carbon tetrachloride (CT) was achieved. The column was packed with a quartz sand and bioaugmented with the Evanite Culture (EV) that is capable of transforming PCE to ethene. The column was fed a synthetic groundwater that was amended with PCE to achieve an influent concentration near its solubility limit (0.10 mM) and formate (1.5 mM) that reacts to produce hydrogen as the ultimate electron donor. The column was operated for over 1600 days prior to the addition of CT. During this period PCE was transformed mainly to vinyl chloride (VC) and ethene (ETH) and minor amounts of cis-dichloroethene (cis-DCE) and TCE. The transformation extent achieved based on the column effluent concentrations ranged from about 50% ETH, 30% VC, and 20 cis-DCE up to 80% ETH and 20% VC. When the column was fed sulfate, it was completely transformed via sulfate reduction. Ferrous iron production from ferric iron reduction was observed early in the study. Acetate was also formed as a result of homoacetogenesis from hydrogen utilization. CT addition (0.015 mM) was started at 1600 days while PCE addition was continued. During the first 25 days of CT addition, CT concentrations gradually increased to 50% of the injection concentration and chloromethane (CM) and CF were observed as transformation products. CT concentrations then decreased with over 98% transformation achieved.CM was removed to below the detection limit and CF concentration decreases to

  8. Protective effect of recombinant human IL-1Ra on CCl4-induced acute liver injury in mice

    OpenAIRE

    Zhu, Run-Zhi; Xiang, Di; Xie, Chao; Li, Jing-Jing; Hu, Jian-Jun; He, Hong-Lin; Yuan, Yun-Sheng; GAO, JIN; HAN, WEI; Yu, Yan

    2010-01-01

    AIM: To evaluate the effects of positive regulation of recombinant human interleukin 1 receptor antagonist (rhIL-1Ra) on hepatic tissue recovery in acute liver injury in mice induced by carbon tetrachloride (CCl4).

  9. 柿叶提取物对CCl4致小鼠急性肝损伤保护作用的研究%Protective effects of extract from persimmon leaves on tetrachloride-induced hepatotoxicity in mice

    Institute of Scientific and Technical Information of China (English)

    张艳; 杨建雄; 马蕊; 王芳

    2013-01-01

    探讨了柿叶醇提物的乙酸乙酯萃取制剂(EAF)对小鼠急性肝损伤的保护作用.腹腔注射四氯化碳(CCl4)致小鼠急性肝损伤模型,测定不同剂量的EAF对血清谷丙转氨酶(ALT)、谷草转氨酶(AST)和碱性磷酸酶(AKP)活性,肝超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)、过氧化氢酶(CAT)活性及丙二醛(MDA)含量的影响,同时对肝组织进行病理学检查.结果表明,EAF具有剂量依赖性地降低血清中ALT、AST、AKP值,增强肝中SOD、GPx、CAT的活性,降低肝组织匀浆中MDA的含量,减轻CCl4对肝脏细胞的病理损伤.100mg/kg是EAF对肝损伤的合适保护剂量.适量的EAF对CCl4所致小鼠急性肝损伤有较好的保护作用.%The effects of ethyl acetate fraction (EAF) containing substances ethanol extracted from persimmon leaves on carbon tetrachloride-induced hepatotoxicity in mice were inrestigated. The acute hepatic injury model was carried out by CC14 injected intraperitoneally. Then, the therapeutic effects of EAF were evaluated based on the activities of alanine aminotransferas (ALT), aspartate aminotransf erase ( AST) , alkaline phosphatase (AKP), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and the content of malondialdehyde (MDA) in liver, and the changes of hepatic pathohistology. The results indicated that different doses of EAF significantly lowered ALT, AST, AKP levels in serum and MDA level in liver along with the restoring of hepatic enzymes like SOD, GPx, and CAT against CC14 treated mice. The pathological changes were also significantly improved in the mice of treating group. Furthermore, it was found that 100 mg/kg was the optimal dose for exhibiting the greatest hepatoprotective effects on CCL,-induced liver injury, indicating that EAF of adequate dose exhibits potent hepatoprotective effects on CC14-induced acute liver damages in mice.

  10. Carbon Tetrachloride Flow and Transport in the Subsurface of the 216-Z-18 Crib and 216-Z-1A Tile Field at the Hanford Site: Multifluid Flow Simulations and Conceptual Model Update

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Mart; Rockhold, Mark L.; Thorne, Paul D.; Last, George V.; Truex, Michael J.

    2006-10-31

    Carbon tetrachloride (CT) was discharged to the 216-Z-9, Z-1A, and Z-18 waste sites that are included in the 200-PW-1 Operable Unit in Hanford 200 West Area. Fluor Hanford, Inc. is conducting a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) remedial investigation/feasibility study (RI/FS) for the 200-PW-1 Operable Unit. As part of this overall effort, Pacific Northwest National Laboratory (PNNL) was contracted to improve the conceptual model of how CT is distributed in the Hanford 200 West Area subsurface through use of numerical flow and transport modeling. This work supports the U.S. Department of Energy's (DOE's) efforts to characterize the nature and distribution of CT in the 200 West Area and subsequently select an appropriate final remedy.

  11. PROTECTIVE ABILITY OF MOMORDICA CHARANTIA L AGAINST CCL4 INDUCED HEPATIC DAMAGE IN RATS

    Directory of Open Access Journals (Sweden)

    Pingale Shirish S

    2010-12-01

    Full Text Available The aim of this study is to evaluate the efficacy of Momordica charantia on the experimental hepatotoxicity induced by carbon tetrachloride (CCl4. Carbon tetrachloride was administered once and simultaneously suspension of dry fruit powder was prepared in aqueous medium and was daily administered at a dose level of 1mg/kg body weight for 4 days. Silymarin was used as a standard drug for this study. Administration of carbon tetrachloride showed significant changes in the levels of serum aminotransferase, alkaline phosphatase, bilirubin and total proteins levels, however necrosis, collagen deposition and altered hepatic architecture were also observed. Markers of liver injury, altered aminotransferase, alkaline phosphatase, bilirubin etc. and morphological changes such as necrosis and collagen deposition were significantly decreased in the rats treated with Momordica charantia fruit powder. These results suggest that the Momordica charantia showed hepatoprotective effect on carbon tetrachloride induced hepatic damage and may be a potential clinical application for treatment of liver diseases.

  12. Titanium tetrachloride burns to the eye.

    OpenAIRE

    Chitkara, D K; McNeela, B. J.

    1992-01-01

    We present eight cases of chemical burns of the eyes from titanium tetrachloride, an acidic corrosive liquid. However it causes severe chemical burns which have a protracted course and features more akin to severe alkali burns. Injuries related to titanium tetrachloride should be treated seriously and accordingly appropriate management is suggested.

  13. Volumetric properties of binary mixture of ethyl acetate and carbon tetrachloride%乙酸乙酯/四氯化碳二元混合体系的体积性质

    Institute of Scientific and Technical Information of China (English)

    赵秀琴; 黄荣谊

    2011-01-01

    The densities of the binary mixture formed by ethyl acetate with carbon tetrachloride were determined in the entire composition range and at the temperature of 288.15-323. IS K and atmospheric pressure. The calculation equations of densities and composition and temperature for the binary system were established, respectively. The results show that the excess molar volumes are positive in entire composition range and at determining temperature. It increases slightly when temperature increases. The regression coefficients and standard deviations were given by fitting the Redlich-Kister equation. Besides, the relation of apparent molar volumes and the molar volumes to the temperature and composition were investigated from density measurements, both values also increase with temperature rise.%常压下测定了乙酸乙酯与四氯化碳二元体系在288.15-323.15 K内全摩尔分数范围的密度,分别建立了该二元体系密度与组成和温度的计算方程.在此基础上,计算了该二元体系的超额摩尔体积,结果表明:该二元体系的超额摩尔体积在所测定温度和全摩尔分数范围内均呈正偏差,且均随温度的升高而偏差增大,并利用Redlich-Kister方程进行了关联,给出了回归系数和标准偏差.另外还探讨了该二元体系的组分表观摩尔体积和摩尔体积与温度和组成的关系,其值随温度的升高均呈增大的趋势.

  14. A mixed quantum-classical molecular dynamics study of the hydroxyl stretch in methanol/carbon tetrachloride mixtures III: nonequilibrium hydrogen-bond dynamics and infrared pump-probe spectra.

    Science.gov (United States)

    Kwac, Kijeong; Geva, Eitan

    2013-06-27

    We present a mixed quantum-classical molecular dynamics study of the nonequilibrium hydrogen-bond dynamics following vibrational energy relaxation of the hydroxyl stretch in a 10 mol % methanol/carbon tetrachloride mixture and pure methanol. The ground and first-excited energy levels and wave functions are identified with the eigenvalues and eigenfunctions of the hydroxyl's adiabatic Hamiltonian and as such depend parametrically on the configuration of the remaining, classically treated, degrees of freedom. The dynamics of the classical degrees of freedom are in turn governed by forces obtained by taking the expectation value of the force with respect to the ground or excited vibrational wave functions. Polarizable force fields and nonlinear mapping relations between the hydroxyl transition frequencies and dipole moments and the electric field along the hydroxyl bond are used, which were previously shown to quantitatively reproduce the experimental infrared steady-state absorption spectra and excited state lifetime [Kwac, K.; Geva, E. J. Phys. Chem. B 2011, 115, 9184; 2012, 116, 2856]. The relaxation from the first-excited state to the ground state is treated as a nonadiabatic transition. Within the mixed quantum-classical treatment, relaxation from the excited state to the ground state is accompanied by a momentum-jump in the classical degrees of freedom, which is in turn dictated by the nonadiabatic coupling vector. We find that the momentum jump leads to breaking of hydrogen bonds involving the relaxing hydroxyl, thereby blue-shifting the transition frequency by more than the Stokes shift between the steady-state emission and absorption spectra. The subsequent nonequilibrium relaxation toward equilibrium on the ground state potential energy surface is thereby accompanied by red shifting of the transition frequency. The signature of this nonequilibrium relaxation process on the pump-probe spectrum is analyzed in detail. The calculated pump-probe spectrum is found

  15. 四氯化碳淘汰背景下氯化聚丙烯的生产技术选择%Technical options for production of chlorinated polypropylene under phaseout of carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    陆颖舟; 杨礼荣; 王开祥; 王林宏; 李春喜

    2011-01-01

    综述了氯化聚丙烯(CPP)的主要生产工艺,提出了几种不使用四氯化碳(CTC)的CPP生产新工艺。分析了不同生产工艺的可行性和适用性,得出非CTC溶剂法是生产油墨用途的低氯化度CPP的最佳选择,而水相悬浮法适用于生产材料等用途的CPP产品,固相法虽有节能减排的特点但还不成熟,值得深入研究的结论。建议大力开发CPP新品种,满足日益多样化的产品需求。%This paper summarizes technologies of chlorinated polypropylene (CPP) production, and presents several new technologies for CPP production that do not use carbon tetrachloride (CTC). The feasibility and applicability of different technologies for CPP production are analyzed. Non-CTC solvent technology is the optimum process to produce CPP with low chlorinity which could be used for printing ink production. Water phase suspension technology is suitable for preparing CPP for applied materials production. Despite its advantage of energy-saving and emission-reduction, solid-phase technology is still not mature and should be further improved. Finally, it is suggested that new varieties of CPP should be developed to meet the increasing demands of diversified production.

  16. Impact of abhrak bhasma and silicon dioxide on histological architecture of liver and kidney in single dose of carbon tetrachloride intoxicated male albino rat

    Directory of Open Access Journals (Sweden)

    Parashuram Teli

    2015-01-01

    Full Text Available Abhrak bhasma is a widely used Ayurvedic drug in various diseases including hepatotoxicity. In the present study, protective effect of graded doses (10, 20, 30 and 40mg/kg body wt of abhrak bhasma and its silica control, SiO2 was studied against CCl4 induced liver and kidney damage in male albino rats during single dose experimental schedule for 24 hrs. Administration of CCl4 (3.0ml/ kg body wt induced fatty necrosis in hepatic cells without affecting kidney histology. Treatment of abhrak bhasma showed dose dependent protection against CCl4 induced liver damage by free radical scavenging activity. Silica in SiO2 form also positively influences liver fatty degeneration induced by single dose of CCl4 but is associated with some hepatocytes hypertrophy.

  17. 静态顶空毛细管柱气相色谱法测定生活饮用水中三氯甲烷和四氯化碳%Determination on Trichloromethane and Carbon tetrachloride in Drinking Water by Static Headspace Capillary Gas Chromatography

    Institute of Scientific and Technical Information of China (English)

    纪增香

    2012-01-01

    建立了静态顶空毛细管柱气相色谱法测定生活饮用水中三氯甲烷和四氯化碳的方法。实验结果显示:三氯甲烷和四氯化碳在其测定范围内线性关系良好,相关系数为0.998~0.997,回收率为89.0%~107.0%。该方法简便、快速、可行。%To establish a static headspace capillary gas chromatography method for the determination of trichloromethane and carbon tetrachloride in drinking water.The results showed that the trichloromehane and carbon tetrachloride in the scope had a good linear relationship,the correlation coefficient were all 0.998~0.997,the recovery rate were 89%~107%.The method is simple,rapid and feasible.

  18. Hyperkalaemia induced by carbonic anhydrase inhibitor.

    OpenAIRE

    Wakabayashi, Y.

    1991-01-01

    An 81-year-old man developed hyperkalaemic and hyperchloraemic metabolic acidosis following treatment with a carbonic anhydrase inhibitor for his glaucoma. He had mild renal failure and selective aldosterone deficiency was confirmed. In this case the treatment did not lead to hypokalaemia because of the limited potassium secretory capacity in the renal tubules from selective aldosterone deficiency; rather, it may have led to hyperkalaemia because metabolic acidosis induced by the carbonic anh...

  19. 某水源地地下水四氯化碳污染特征分析%Characteristics of Carbon Tetrachloride Pollution in Groundwater in a Water Source

    Institute of Scientific and Technical Information of China (English)

    郭英; 田西昭; 张立宝; 何微; 单强

    2011-01-01

    通过对某水源地地下水的四氯化碳污染调查和日常监测数据分析,研究了该水源地四氯化碳污染晕的形态和变化特征,并选取典型水源井对其四氯化碳动态特征进行了分析.在污染发现初期,污染面积为2.73 km2,最高污染浓度为249.7μg/L,随着后期污染治理工作的开展,污染面积减小到1.24 km2,最高污染浓度下降到3.62μg/L.分析认为,污染晕形态在空间分布上主要受地下水流场的控制,同时受降水量、地下水位标高及开采量等多种因素控制,污染物由北区井群向南区井群扩散.单井四氯化碳含量动态则呈现出南北区的相反特征:在北区,四氯化碳含量随着地下水位的上升而上升,并随地下水流向南扩散;在南区,四氯化碳含量随着地下水位的上升而下降,并随地下水流向地下水漏斗中心汇集.这是由于赋存于SD1井附近包气带中的四氯化碳尚未清除造成的.%Based on the investigation and everyday monitoring data of the carbon tetrachloride (CT) pollution in the groundwater occurring at a water source zone,this paper studies the form of the contaminant plume as well as the changing features,and also it analyzes the dynamic characteristics of the CT in several chosen water source wells.The contaminated area at the initial stage reached 2.73 km2 ,with the max contaminant concentration of 249.7 μg/L.As the pollution control is carried out at the later stage,the contaminated area reduces to 1.24 km2 ,with the max contaminant concentration reduces to 3.62 μg/L.The results indicated that the form of contaminant plume was spatially determined by the groundwater flow field as a primary factor, and other factors included precipitation, elevation of groundwater level as well as the yield etc.The contaninant plume extends form the northern wells to the southern ones.In terms of the dynamic content of the CT in a single well, it's quite different in the northern and southern areas

  20. Chloroform and Carbon Tetrachloride Determination in Drinking Water with Headspace Capillary Column Gas Chromatography%顶空毛细管柱气相色谱法测定生活饮用水中的氯仿和四氯化碳

    Institute of Scientific and Technical Information of China (English)

    袁波; 徐文清

    2014-01-01

    本方法采用顶空气相色谱法,利用毛细管柱、μ-ECD微电子捕获检测器对饮用水中氯仿和四氯化碳残留量进行了检测分析,检出限分别为0.02和0.2μg/L,回收率90.4%~95.6%,本方法分析简便,容易操作。%Residue of chloroform and carbon tetrachloride in drinking water were measured by using headspace gas chromatography with capillary column or μ-ECD microelectronics capture detector. Detection limit was 0.02 and 0.2μg/L, respectively. Recovery was 90.4%-95.6%. This method was simple and sasy.

  1. Substrate-induced strain in carbon nanodisks

    International Nuclear Information System (INIS)

    Graphitic nanodisks of typically 20–50 nm in thickness, produced by the so-called Kvaerner Carbon Black and Hydrogen Process were dispersed on gold substrate and investigated by atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), and confocal Raman spectroscopy. The roughness of the gold surface was drastically changed by annealing at 400 °C. AFM measurements show that this change in the surface roughness induces changes also in the topography of the nanodisks, as they closely follow the corrugation of the gold substrate. This leads to strained nanodisks, which is confirmed also by confocal Raman microscopy. We found that the FE-SEM contrast obtained from the disks depends on the working distance used during the image acquisition by In-lens detection, a phenomenon which we explain by the decrease in the amount of electrons reaching the detector due to diffraction. This process may affect the image contrast in the case of other layered materials, like hexagonal boron nitride, and other planar hybrid nanostructures, too. - Highlights: • Bending of carbon nanodisks is induced by the roughness of the gold substrate. • Confocal Raman microscopy shows a compressive strain induced in the nanodisks. • The electron microscopy contrast of nanodisks depends on the working distance

  2. Stationary plume induced by carbon dioxide dissolution

    International Nuclear Information System (INIS)

    In this paper, laminar convection flows induced by carbon dioxide absorption are addressed from experimental, numerical and theoretical points of view. A vertical glass tube (of centimetre scale) filled with distilled water is subjected to a sudden increase in the partial pressure of carbon dioxide. As a result of the diffusion of the gas into the unsaturated solution, a thin layer of fluid located underneath the surface becomes heavier. This initial density gradient first destabilizes to form a plume, which goes downwards through the entire cell. After a first transient pulsating regime (periodic succession of such Rayleigh-Benard plumes), a stationary flow settles in the tube, which is maintained by the constant supply of gas at the surface. At late stages, this stationary regime is followed by an aperiodic regime, which lasts until the complete saturation of the solution (thermodynamic equilibrium). The present study only focuses on the stationary regime, whose characteristics appear to be almost independent of the Bond number and the aspect ratio but strongly dependent on the chemical Rayleigh number. Three decades of Rayleigh numbers are explored using particle image velocimetry measurements, which allows for a precise determination of the scaling exponents for the vertical velocity amplitude and the plume width. The assumption that gravity and a constant pressure gradient balance the viscous effects enables us to derive an analytic expression for the stationary vertical velocity on the axis, which scales as Ra2/3 (ln Ra)1/3. As a consequence, the width of the plume scales as Ra-1/6 (ln Ra)-1/3 and the mass Nusselt number as (Ra= ln Ra)1/3. These scalings are in excellent agreement with the experimental and numerical results. The multiplicative constants of these scalings can also be calculated and show a fairly good agreement if a rigid boundary condition (no-slip) is assumed at the free surface. (authors)

  3. Microbially induced corrosion of carbon steel in deep groundwater environment

    Directory of Open Access Journals (Sweden)

    Pauliina eRajala

    2015-07-01

    Full Text Available The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland for periods of three and eight months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel.

  4. Microbially induced corrosion of carbon steel in deep groundwater environment

    Science.gov (United States)

    Rajala, Pauliina; Carpén, Leena; Vepsäläinen, Mikko; Raulio, Mari; Sohlberg, Elina; Bomberg, Malin

    2015-01-01

    The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste. Here we studied the corrosion inducing ability of indigenous microbial community from a deep bedrock aquifer. Carbon steel coupons were exposed to anoxic groundwater from repository site 100 m depth (Olkiluoto, Finland) for periods of 3 and 8 months. The experiments were conducted at both in situ temperature and room temperature to investigate the response of microbial population to elevated temperature. Our results demonstrate that microorganisms from the deep bedrock aquifer benefit from carbon steel introduced to the nutrient poor anoxic deep groundwater environment. In the groundwater incubated with carbon steel the planktonic microbial community was more diverse and 100-fold more abundant compared to the environment without carbon steel. The betaproteobacteria were the most dominant bacterial class in all samples where carbon steel was present, whereas in groundwater incubated without carbon steel the microbial community had clearly less diversity. Microorganisms induced pitting corrosion and were found to cluster inside the corrosion pits. Temperature had an effect on the species composition of microbial community and also affected the corrosion deposits layer formed on the surface of carbon steel. PMID:26257707

  5. Isomerization of -carotene by titanium tetrachloride catalyst

    Indian Academy of Sciences (India)

    V Rajendran; B H Chen

    2007-05-01

    Isomerization of all-trans--carotene occurs during shaking with 0.5% of titanium tetrachloride catalyst in methylene chloride at room temperature. In the present study we compared two types of columns C18 and C30 and various solvent systems for the separation of -carotene and its cis isomers by high performance liquid chromatography (HPLC). Results showed that -carotene isomers were resolved by employing a C30 column with a mobile phase of methanol (100%) (A) and methylene chloride (100%) (B) under a gradient elution condition. A total of eleven cis isomers and one all-trans--carotene isomer were resolved within 50 min at a flow rate of 1 ml/min and detection wave-length of 470 nm.

  6. EVALUATION OF ANTI-INFLAMMATORY PROPERTY OF VANILLIN IN CARRAGEENAN INDUCED PAW EDEMA MODEL IN RATS

    OpenAIRE

    SRIKANTH D, Vishma Hydie Menezes, Nischal Saliyan, Rathnakar UP*, Shiv Prakash G, Sahana D Acaharya, Ashok Shenoy K, Udupa AL

    2013-01-01

    Introduction: Vanillinis known to have antimutagenic, anti-invasive and metastatic suppression potential. Antinociceptive property in acetic acid induced visceral pain models, antioxidant and hepato-protective properties of in carbon tetrachloride-treated rats have also been demonstrated. Objective of this study is to evaluate the effect of vanillin on acute inflammation induced by carrageenan in rats.Methods: Rats were assigned to five groups [Control, Asprin and three Vanillin groups,] of s...

  7. Literature information applicable to the reaction of uranium oxides with chlorine to prepare uranium tetrachloride

    International Nuclear Information System (INIS)

    The reaction of uranium oxides and chlorine to prepare anhydrous uranium tetrachloride (UCl4) are important to more economical preparation of uranium metal. The most practical reactions require carbon or carbon monoxide (CO) to give CO or carbon dioxide (CO2) as waste gases. The chemistry of U-O-Cl compounds is very complex with valances of 3, 4, 5, and 6 and with stable oxychlorides. Literature was reviewed to collect thermochemical data, phase equilibrium information, and results of experimental studies. Calculations using thermodynamic data can identify the probable reactions, but the results are uncertain. All the U-O-Cl compounds have large free energies of formation and the calculations give uncertain small differences of large numbers. The phase diagram for UCl4-UO2 shows a reaction to form uranium oxychloride (UOCl2) that has a good solubility in molten UCl4. This appears more favorable to good rates of reaction than reaction of solids and gases. There is limited information on U-O-Cl salt properties. Information on the preparation of titanium, zirconium, silicon, and thorium tetrachlorides (TiCl4, ZrCl4, SiCl4, ThCl4) by reaction of oxides with chlorine (Cl2) and carbon has application to the preparation of UCl4

  8. Irradiation-induced structure and property changes in tokamak plasma-facing, carbon-carbon composites

    International Nuclear Information System (INIS)

    Carbon-carbon composites are an attractive choice for fusion reactor plasma-facing components because of their low atomic number, superior thermal shock resistance, and low neutron activation. Next generation plasma fusion reactors, such as the International Thermonuclear Experimental Reactor (ITER), will require advanced carbon-carbon composite materials possessing high thermal conductivity to manage the anticipated severe heat loads. Moreover, ignition machines such as ITER will produce large neutron fluxes. Consequently, the influence of neutron damage on the structure and properties of carbon-carbon composite materials must be evaluated. Data from two irradiation experiments are reported and discussed here. Carbon-carbon composite materials were irradiated in target capsules in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL). A peak damage dose of 4.7 displacements per atom (dpa) at 600 degree C was attained. The carbon materials irradiated included uni-directional, two-directional, and three-directional carbon-carbon composites. Dimensional changes are reported for the composite materials and are related to single crystal dimensional changes through fiber and composite structural models. Moreover, the irradiation-induced dimensional changes are reported and discussed in terms of their architecture, fiber type, and graphitization temperature. The effect of neutron irradiation on thermal conductivity of two three-directional, carbon-carbon composites is reported and the recovery of thermal conductivity due to thermal annealing is discussed

  9. Hydrogenation of Silicon Tetrachloride in Microwave Plasma

    Institute of Scientific and Technical Information of China (English)

    卢振西; 张伟刚

    2014-01-01

    This study investigated the hydrogenation of silicon tetrachloride (SiCl4) in microwave plasma. A new launcher of argon (Ar) and hydrogen (H2) plasma was introduced to produce a non-thermodynamic equilibrium ac-tivation plasma. The plasma state exhibited a characteristic temperature related to the equilibrium constant, which was termed“Reactive Temperature”in this study. Thus, the hydrogenation of SiCl4 in the plasma could easily be handled with high conversion ratio and very high selectivity to trichlorosilane (SiHCl3). The effects of SiCl4/Ar and H2/Ar ratios on the conversion were also investigated using a mathematical model developed to determine the op-timum experimental parameters. The highest hydrogenation conversion ratio was produced at a H2/SiCl4 molar ratio of 1, with mixtures of SiCl4 and H2 to Ar molar ratio of 1.2 to 1.4. In this plasma, the special system pressure and incident power were required for the highest energy efficiency of hydrogenating SiCl4, while the optimum system pressure varies from 26.6 to 40 kPa depending on input power, and the optimum feed gas (H2 and SiCl4) molar en-ergy input was about 350 kJ·mol-1.

  10. The protective effect of Murraya koenigii leaves against carbon tetra chloride-induced hepatic damage in rats

    Institute of Scientific and Technical Information of China (English)

    Brahma Naidu Parimi; Ramgopal Mopuri; Balaji Meriga

    2014-01-01

    Objective: To evaluate the efficacy of methanolic extract of Murraya koenigii (MMK) leaves in attenuating the hepatic damage inflicted by carbon tetrachloride (CCl4), a potent oxidative stress inducer and a model hepatotoxicant.Methods:Rats were divided into six groups of five each: normal control group, CCl4 group, CCl4+silymarin group, CCl4+MMK group (200 mg/kg body weight), CCl4+MMK group (300 mg/kg body weight) and CCl4+MMK group (500 mg/kg body weight). Rats were intraperitoneally injected with 20% CCl4 in corn oil (1 mL/kg body weight) and MMK was orally administered for 3 weeks. Levels of hepatic markers such as alanine transaminase, aspartate transaminase, alkaline phosphatase and total bilirubin were measured. Activities of superoxide dismutase, catalase and glutathione peroxidase were assayed and malondialdehyde content was measured. For histopathological examination, liver microtome sections were prepared and observed under light microscope.Results:Oral administration of MMK had significantly reduced the activities of aspartate transaminase, alanine transaminase, alkaline phosphatase and bilirubin content in a dose-dependent manner, which were elevated by CCl4. However, CCl4-induced rise in lipid peroxidation and drop in superoxide dismutase, catalase and glutathione peroxidase activities were reversed by MMK administration. Further, the hepatoprotective activity of MMK was supported by histopathological examination of liver microtome sections.Conclusions:Our biochemical and histological studies demonstrate the potential antioxidant and hepatoprotective activity of MMK and our results scientifically validate the often use of MMK leaves in food preparation and in Ayurvedic medicine in India and neighboring countries.

  11. Laser induced deformation in polydimethylsiloxane membranes with embedded carbon nanopowder

    International Nuclear Information System (INIS)

    We demonstrate optically induced micron-range deformation of polydimethylsiloxane (PDMS) membranes with embedded carbon nanopowder. The mechanical deformation can be controlled by low power laser irradiation of the samples and the resulting surface modifications are analyzed via dynamic speckle measurements. Photothermal effects due to optical absorption by the nanopowder are shown to deform the polymer samples leading to localized mechanical stresses induced via thermal expansion of the PDMS. (technical note)

  12. Antioxidant Activity of The Ancient Herb, Holy Basil in CCl4-Induced Liver Injury in Rats

    OpenAIRE

    Ponnusam, Yuvaraj; Louis, Therasilin; Madhavachandran, V; Kumar, Suresh; Thoprani, Neelam; Hamblin, Michael R.; Lakshmanan, Shanmugamurthy

    2015-01-01

    An herbal preparation called “holy basil plus herbal powder” (HBPP) containing Ocimum santum, Withania somnifera, Pongamia pinnata, Plumbago indica, Emblica officinalis and Curcuma longa was investigated as an antioxidant and hepatoprotective agent. The antioxidant activity of HBPP was investigated in rats with liver injury induced by oral administration of carbon tetrachloride:olive oil (1:1). HBPP was administered orally at 500 mg/kg daily for 7 days before. HBPP exhibited statistically sig...

  13. Pyrazole prevention of CC14-induced ultrastructural changes in rat liver.

    OpenAIRE

    Bernacchi, A. S.; de Castro, C. R.; De Toranzo, E. G.; Marzi, A.; de Ferreyra, E. C.; de Fenos, O. M.; Castro, J.A.

    1980-01-01

    Carbon tetrachloride (CC14) administration to rats leads to an early dilatation, vesiculation and disorganization of the liver endoplasmic reticulum (ER). This hepatotoxin also causes detachment of ribosomes from ER membranes, dilatation of the Golgi cisternae and occasionally dilatation of the perinuclear membrane. Prior treatment of the rats with pyrazole completely prevents CC14- induced ultrastructural alterations observed in liver at 3 h. This drug is known to decrease the intensity of t...

  14. Isorhamnetin-3-O-galactoside Protects against CCl4-Induced Hepatic Injury in Mice

    OpenAIRE

    Kim, Dong-Wook; Cho, Hong-Ik; Kim, Kang-Min; Kim, So-Jin; Choi, Jae Sue; Kim, Yeong Shik; Lee, Sun-Mee

    2012-01-01

    This study was performed to examine the hepatoprotective effect of isorhamnetin-3-O-galactoside, a flavonoid glycoside isolated from Artemisia capillaris Thunberg (Compositae), against carbon tetrachloride (CCl4)-induced hepatic injury. Mice were treated intraperitoneally with vehicle or isorhamnetin-3-O-galactoside (50, 100, and 200 mg/kg) 30 min before and 2 h after CCl4 (20 μl/kg) injection. Serum aminotransferase activities and hepatic level of malondialdehyde were significantly higher af...

  15. Identification of promoters and enhancers induced by carbon nanotube exposure

    DEFF Research Database (Denmark)

    Bornholdt, Jette; Lilje, Berit; Saber, Anne Thoustrup;

    Usage of carbon nanotubes (CNTs) is increasing in industry due to their mechanical and electrical properties. However, pulmonary exposure to CNTs induces, an asbestos-like toxicological response characterized by persistent inflammation, granuloma formation and fibrosis with low no-effect levels...

  16. Biogrout, ground improvement by microbial induced carbonate precipitation

    NARCIS (Netherlands)

    Van Paassen, L.A.

    2009-01-01

    Biogrout is a new ground improvement method based on microbially induced precipitation of calcium carbonate (MICP). When supplied with suitable substrates, micro-organisms can catalyze biochemical conversions in the subsurface resulting in precipitation of inorganic minerals, which change the mechan

  17. Current-induced dynamics in carbon atomic contacts

    DEFF Research Database (Denmark)

    Lu, Jing Tao; Gunst, Tue; Brandbyge, Mads;

    2011-01-01

    voltage, which can be used to explore current-induced vibrational instabilities due the NC/BP forces. Furthermore, using tight-binding and the Brenner potential we illustrate how Langevin-type molecular-dynamics calculations including the Joule heating effect for the carbon-chain systems can be performed...

  18. Study on Determination of Off in Water by Extraction Using Tetrachloroethylene Instead of Carbon Tetrachloride%四氯乙烯代替四氯化碳测定水中油类物质初探

    Institute of Scientific and Technical Information of China (English)

    熊杰; 孙方中; 罗晓慧; 王丽萍

    2011-01-01

    通过使用四氯乙烯代替四氯化碳测定水中油类物质的对比实验,得到如下结论:四氯乙烯作萃取剂时,标准曲线线性相关系数为0.9999,检出限为0.336mg/L,精密度和准确度符合质控要求。但标准曲线方程的斜率较差,在分析浓度较低的样品时,准确度相对误差较大,萃取回收率不高。由此可以看出,使用四氯乙烯分析油类物质的局限性较大,分析方法还需进一步研究。%By conducting contrast experiments for determination of oil in water using tetrachloroethylene instead of carbon tetrackloride, it concluded that when tetraehloroethylene was used as extractant, the liner correlation coefficient was 0. 9999, detection limit was 0. 336mg/L and the precision and accuracy met the requirements of the quality control. However the slope of the standard curve equation was low. When samples with low concentration were analyzed, the relative errors of accuracy were low and the extraction recovery was poor. It concluded that there were still limitations to use tetrachloreethylene for determination of oil in water, so the method needs further studies.

  19. Carbon analysis for inspecting carbonation of concrete using a TEA CO2 laser-induced plasma.

    Science.gov (United States)

    Kagawa, Kiichiro; Idris, Nasrullah; Wada, Munehide; Kurniawan, Hendrik; Tsuyuki, Kenichiro; Miura, Satoru

    2004-08-01

    It has been demonstrated that a spectrochemical analysis of carbon using the laser plasma method can be successfully applied to inspect the carbonation of concrete by detecting carbon produced in aged concrete by a chemical reaction of Ca(OH)2 with CO2 gas in environmental air, turning into CaCO3, which induces degradation of the quality of building concrete. A comparative study has been made using a TEA CO2 laser (500-1000 mJ) and a Q-switched Nd-YAG laser (50-200 mJ) to search for the optimum conditions for carbon analysis, proving the advantage of the TEA CO2 laser for this purpose. Also, it was clarified that laser irradiation with suitable defocusing conditions is a crucial point for obtaining high sensitivity in the detection of carbon. Practical experiments on the inspection of carbonation were carried out using both a concrete sample that had been intentionally carbonated by exposure to high concentrations of CO2 gas and a naturally carbonated concrete sample. As a result, good coincidence was observed between the laser method and the ordinary method, which uses the chemical indicator phenolphthalein, implying that this laser technique is applicable as an in situ quantitative method of inspection for carbonation of concrete. PMID:18070383

  20. Protective effect of Livactine against CCl4 and paracetamol induced hepatotoxicity in adult Wistar rats

    Directory of Open Access Journals (Sweden)

    Candasamy Mayuren

    2010-10-01

    Full Text Available Background: Liver disease has become one of the serious health problems as it is exposed to many kinds of xenobiotics and therapeutic agents. Moreover the rapidly growing morbidity and mortality from liver disease are attributable to the increasing number of chemical compounds and environmental pollution. Unfortunately, so far, in the modern era of medicine there is no specific treatment to counter the menacing impact of these dreaded diseases. Many polyherbal formulations are used widely to treat these disorders. Livactine is a polyherbal formulation and is claimed to be useful in jaundice and biliary dysfunctions. Most of these formulations do not have standard and approved reports stating their pharmacological action or therapeutic efficacy. Therefore, there is a need for experimental confirmation of the pharmacological effects of this formulation. The rationale behind the selection of carbon tetrachloride is due to its free radical mechanism based liver injury, and paracetamol is consumed widely by the human population and it is also a potential liver hazard. Aim: To evaluate the anti-hepatotoxic activity of Livactine against carbon tetrachloride & paracetamol induced toxicity in rats. Material and Methods: Albino rats of Wistar strain were used to evaluate the hepatoprotective activity of Livactine against carbon tetrachloride & paracetamol induced toxicity. Liver damage was assessed by estimating various biochemical parameters such as serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, lactate dehydrogenase, alkaline phosphatase, acid phosphatase, total bilirubin, and total protein. The results of the rats treated with Livactine were compared with that of Liv-52.Results: Livactine showed significant dose dependent hepatoprotective effect by reducing elevated serum enzyme levels when compared to that of Liv-52.Conclusion: Our findings confirm that the formulation was found to be effective pharmacologically at

  1. Agaricus blazei Murill as an efficient hepatoprotective and antioxidant agent against CCl4-induced liver injury in rats

    OpenAIRE

    Al-Dbass, Abeer M.; Al- Daihan, Sooad K.; Bhat, Ramesa Shafi

    2012-01-01

    Agaricus blazei Murill is one of the very popular edible medicinal mushrooms. The present study investigated the protective effect of this biologically active mushroom on the tissue peroxidative damage and abnormal antioxidant levels in carbon tetrachloride induced hepatotoxicity in male albino rats. Male albino rats of Sprague–Dawley strain weighting (120–150 g) were categorized into five groups. The first group served as the normal control, the second and the third groups were treated with ...

  2. Current-induced dynamics in carbon atomic contacts

    Directory of Open Access Journals (Sweden)

    Jing-Tao Lü

    2011-12-01

    Full Text Available Background: The effect of electric current on the motion of atoms still poses many questions, and several mechanisms are at play. Recently there has been focus on the importance of the current-induced nonconservative forces (NC and Berry-phase derived forces (BP with respect to the stability of molecular-scale contacts. Systems based on molecules bridging electrically gated graphene electrodes may offer an interesting test-bed for these effects.Results: We employ a semi-classical Langevin approach in combination with DFT calculations to study the current-induced vibrational dynamics of an atomic carbon chain connecting electrically gated graphene electrodes. This illustrates how the device stability can be predicted solely from the modes obtained from the Langevin equation, including the current-induced forces. We point out that the gate offers control of the current, independent of the bias voltage, which can be used to explore current-induced vibrational instabilities due the NC/BP forces. Furthermore, using tight-binding and the Brenner potential we illustrate how Langevin-type molecular-dynamics calculations including the Joule heating effect for the carbon-chain systems can be performed. Molecular dynamics including current-induced forces enables an energy redistribution mechanism among the modes, mediated by anharmonic interactions, which is found to be vital in the description of the electrical heating.Conclusion: We have developed a semiclassical Langevin equation approach that can be used to explore current-induced dynamics and instabilities. We find instabilities at experimentally relevant bias and gate voltages for the carbon-chain system.

  3. Destructive Adsorption of Carbon Tetrachloride on Alkaline Earth Metal Oxides

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Mestl, Gerhard; Rosynek, Michael P.; Krawietz, Thomas R.; Haw, James F.; Lunsford, Jack H.

    2001-01-01

    The destructive adsorption of CCl4 on MgO, CaO, SrO, and BaO has been studied as a function of the reaction temperature and the amount of CCl4 injected. The reaction was followed using in situ Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and 13 C mag

  4. Modeling of induced seismicity during mineral carbon sequestration

    Science.gov (United States)

    Yarushina, V.; Bercovici, D. A.

    2013-12-01

    Rapidly developing carbon capture and storage (CCS) technologies are a promising way of reducing the climate impact of greenhouse gases. These technologies involve injecting large amounts of CO2-bearing fluids underground, which potentially leads to high pore pressure and the conditions for seismic activity in the proximity of the injection site. Previously, we developed a simple conceptual model to estimate the seismic risk of mineral or mafic CCS operations (Yarushina & Bercovici, GRL vol.40, doi:10.1002/grl.50196, 2013). In this model, the storage reservoir is treated as a porous rock with grains that evolve during carbonation reactions. Seismic triggering occurs when local stresses at grain-grain contacts reach the Mohr-Coulomb failure criterion. We showed that injection of CO2 into reactive mafic or ultramafic rocks potentially reduces seismic risk since carbonation reactions increase the contact area between the rock grains and reduce the local stresses. Here we further develop this model and consider the effect of fluid injection flux and pressure gradients along grain boundaries on induced seismicity. Grain evolution not only changes the stress support but also alters the matrix permeability, which in turn affects the driving pressure gradients and the associated deviatoric stresses. The resulting coupled porous flow, chemical reactive grain-growth and failure model is an important step in understanding the seismic risks of carbon sequestration.

  5. Erythrocyte stiffness during morphological remodeling induced by carbon ion radiation.

    Directory of Open Access Journals (Sweden)

    Baoping Zhang

    Full Text Available The adverse effect induced by carbon ion radiation (CIR is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy or X-rays (2, 4, 6, and 12 Gy for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-α1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy. The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-α1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study

  6. UV-induced carbon monoxide emission from living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard;

    2013-01-01

    The global burden of carbon monoxide (CO) is rather uncertain. In this paper we address the potential for UV-induced CO emission by living terrestrial vegetation surfaces. Real-time measurements of CO concentrations were made with a cavity enhanced laser spectrometer connected in closed loop...... to either an ecosystem chamber or a plant-leaf scale chamber. Leaves of all examined plant species exhibited emission of CO in response to artificial UV-radiation as well as the UV-component of natural solar radiation. The UV-induced rate of CO emission exhibited a rather low dependence on temperature......, indicating an abiotic process. The emission of CO in response to the UV-component of natural solar radiation was also evident at the ecosystem scale....

  7. Effect of Fiber Length on Carbon Nanotube-Induced Fibrogenesis

    Directory of Open Access Journals (Sweden)

    Amruta Manke

    2014-04-01

    Full Text Available Given their extremely small size and light weight, carbon nanotubes (CNTs can be readily inhaled by human lungs resulting in increased rates of pulmonary disorders, particularly fibrosis. Although the fibrogenic potential of CNTs is well established, there is a lack of consensus regarding the contribution of physicochemical attributes of CNTs on the underlying fibrotic outcome. We designed an experimentally validated in vitro fibroblast culture model aimed at investigating the effect of fiber length on single-walled CNT (SWCNT-induced pulmonary fibrosis. The fibrogenic response to short and long SWCNTs was assessed via oxidative stress generation, collagen expression and transforming growth factor-beta (TGF-β production as potential fibrosis biomarkers. Long SWCNTs were significantly more potent than short SWCNTs in terms of reactive oxygen species (ROS response, collagen production and TGF-β release. Furthermore, our finding on the length-dependent in vitro fibrogenic response was validated by the in vivo lung fibrosis outcome, thus supporting the predictive value of the in vitro model. Our results also demonstrated the key role of ROS in SWCNT-induced collagen expression and TGF-β activation, indicating the potential mechanisms of length-dependent SWCNT-induced fibrosis. Together, our study provides new evidence for the role of fiber length in SWCNT-induced lung fibrosis and offers a rapid cell-based assay for fibrogenicity testing of nanomaterials with the ability to predict pulmonary fibrogenic response in vivo.

  8. The Significance and Insignificance of Carbon Nanotube-Induced Inflammation

    Directory of Open Access Journals (Sweden)

    Matthew S.P. Boyles

    2014-02-01

    Full Text Available In the present review article immune responses induced by carbon nanotubes (CNTs are addressed. As inhalation is considered to be the primary entry route, and concern has been raised by similar high aspect ratio materials, the main focus lies on immune responses upon pulmonary exposure. Inflammation-related findings from both in vivo studies and in vitro models are reviewed, and the major responsible characteristics, which may drive CNT-induced inflammation in the lung, are discussed. In a second part, responses upon intentional administration of CNTs via subcutaneous and intravenous application are addressed, including their potential benefits and drawbacks for immunotherapy. Finally, the gastrointestinal tract as an alternative exposure route is briefly discussed. While there are many studies identifying numerous other factors involved in CNT-driven toxicity, e.g., cytotoxicity, oxidative stress, and genotoxicity, the focus of this review was kept solely on CNT-induced inflammation. Overall the literature has shown that CNTs are able to induce inflammation, which in some cases was a particularly robust response coinciding with the development of pro-fibrotic conditions. In the majority of cases the greatest inflammatory responses were associated with CNTs of considerable length and a high aspect ratio, accompanied by other factors like dispersion and sample purity.

  9. The study of susceptibility to carbon tetrachloride and benzene in offspring of expanded simple tandem repeats mutation mice exposed to formaldehyde%甲醛致扩张性简单串联重复序列突变小鼠子代对四氯化碳和苯暴露易感性研究

    Institute of Scientific and Technical Information of China (English)

    王超; 刘云儒; 周印; 李爱萍; 周建伟

    2011-01-01

    为5.88‰±4.55‰,F10代为8.25‰±2.06‰;C组1000 mg/kg苯染毒组:F5代为7.50‰±6.99‰,F10代为10.67‰±1.16‰;H组500 mg/kg苯染毒组:F5代为7.88‰±3.09‰,F10代为9.20‰±1.30‰;H组1000 mg/kg苯染毒组:F5代为9.63‰±4.34‰,F10代为13.33‰±2.08‰)随苯剂量的增加而增加,与溶剂对照组(C组F5代为1.13‰±0.35‰,F10代为1.20‰±0.82‰;H组F5代为1.25‰±0.46‰,F10代为1.33‰±1.03‰)的差异均有统计学意义(P<0.05,P<0.01).结论 甲醛暴露引起的基因组ESTR突变可改变子代小鼠对CCl4和苯的易感性.ESTR突变可能是影响机体对化学物易感性的生物学标志,其分子机制有待进一步阐明.%Objective To investigate the susceptibility to carbon tetrachloride and benzene in offspring of expanded simple tandem repeats (ESTR) mutation mice exposed to formaldehyde (FA). Methods F5 and F10 offspring (200 mg/m3 ×2 hours) served as H group and ICR mice were used as control group(group C). The F5 and F10 offspring were exposed to 10 ml/kg carbon tetrachloride at the doses of 0.05%, 0.50% or 5.00% for 24 hours, respectively or 500 or 1000 mg/kg benzene for 24 hours, respectively by intraperitoneal injection. Serum alanine transaminase (ALT), aspartate transaminase (AST) and the hepatic superoxide dismutase (SOD) or malondialdehyde (MDA) were detected; also the hepatic pathological changes were observed under light microscope; the micronucleus in sternum bone marrow cells as the biomarker of benzene blood toxicity were measured. Results ALT and AST activities in group C of F5 mice exposed to 0.50% and 5.00% CCl4, ALT in groups C and H of F10 mice exposed to 0.05%, 0.50%, 5.00% CCl4, AST in groups C and H of F10 mice exposed to 0.50% and 5.00% CCl4 were significantly higher than those in controls, respectively (P<0.05); as compared to the control, hepatic SOD activities in group C of F5 and F10 mice exposed to 0.50% and 5.00% CCl4, in group H of F5 mice exposed to 0.50% and 5.00% CCl4, and

  10. Interannual Variations of MLS Carbon Monoxide Induced by Solar Cycle

    Science.gov (United States)

    Lee, Jae N.; Wu, Dong L.; Ruzmaikin, Alexander

    2013-01-01

    More than eight years (2004-2012) of carbon monoxide (CO) measurements from the Aura Microwave Limb Sounder (MLS) are analyzed. The mesospheric CO, largely produced by the carbon dioxide (CO2) photolysis in the lower thermosphere, is sensitive to the solar irradiance variability. The long-term variation of observed mesospheric MLS CO concentrations at high latitudes is likely driven by the solar-cycle modulated UV forcing. Despite of different CO abundances in the southern and northern hemispheric winter, the solar-cycle dependence appears to be similar. This solar signal is further carried down to the lower altitudes by the dynamical descent in the winter polar vortex. Aura MLS CO is compared with the Solar Radiation and Climate Experiment (SORCE) total solar irradiance (TSI) and also with the spectral irradiance in the far ultraviolet (FUV) region from the SORCE Solar-Stellar Irradiance Comparison Experiment (SOLSTICE). Significant positive correlation (up to 0.6) is found between CO and FUVTSI in a large part of the upper atmosphere. The distribution of this positive correlation in the mesosphere is consistent with the expectation of CO changes induced by the solar irradiance variations.

  11. Kinetics and Mechanism of Carbon Tetrachloride Rapid Reduction by Nanoscale Ni-Fe Particles Using Scanning Electron Microscope%利用扫描电镜技术研究纳米Ni-Fe 颗粒对四氯化碳快速脱氯的机理

    Institute of Scientific and Technical Information of China (English)

    黄园英; 王倩; 韩子金; 刘菲

    2015-01-01

    纳米铁具有高的比表面积和高反应活性,能快速将氯代烯烃还原成无毒氯离子、乙烯和乙烷,但对于氯代烷烃的脱氯仍能产生大量的氯代中间或最终产物,可以通过合成制得纳米双金属提高脱氯速率和减少氯代中间产物。本文利用扫描电镜测得实验室制备的纳米 Ni -Fe(2%,质量分数)颗粒直径为20~60 nm,通过批实验方式对纳米 Ni -Fe 降解四氯化碳的反应动力学性质、产物、持久性能和反应机理进行了探讨。结果表明,纳米 Ni -Fe 体系主要最终产物为42% CH4和17% CH2 Cl2。与铸铁屑和纳米铁相比,纳米Ni -Fe由于催化脱氯加氢,显著提高了氯代烃脱氯速率,同时降低了有毒氯代产物的产量,且 Ni 作为催化剂不会进入水体引起二次污染。纳米 Ni -Fe 颗粒在空气中具有很好的稳定性,虽然降解四氯化碳的最终产物CH4与纳米 Pd -Fe 相比少13%,但由于价格便宜,有望在工程上应用于氯代有机化合物水土污染治理。%The nanoscale iron particles have high specific surface area and high reactivity,can be used to rapidly reduce chlorinated alkene to the non-toxic chloride ions,chlorine-free end products ethene and ethane.But nanoscale iron particle degrades chlorinated alkanes with much toxic intermediate or end products.A small amount of a second metal deposited on the iron surface has proved to enhance the reactivity of metal particles.In this paper,laboratory-synthesized nanoscale Ni-Fe (2% by weight)particles have diameters on the order of 20 -60 nm using Scanning Electron Microscope.In batch experiments,the kinetics,products,stability of performance,and mechanism of carbon tetrachloride (CT)by Ni-Fe nanoparticles were investigated.CH4 (~42%)and CH2 Cl2 (~17%)in nanoscale Ni-Fe system were the major end products.Compared to nanoscale iron and the cast iron scarp,a major benefit of the nanoscale Ni-Fe particles

  12. Weldability of Low Carbon Transformation Induced Plasticity Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Mei; LI Lin; FU Ren-yu; ZHANG Ji-cheng; WAN Zi

    2008-01-01

    Transformation induced plasticity (TRIP) steel exhibited high or rather high carbon equivalent (CE) because of its chemical composition,which was a particularly detrimental factor affecting weldability of steels.Thus the weldability of a TRIP steel (grade 600) containing (in mass percent,%) 0.11C-1.19Si-1.67Mn was extensively studied.The mechanical properties and impact toughness of butt joint,the welding crack susceptibility of weld and heat affected zone (HAZ) for tee joint,control thermal severity (CTS) of the welded joint,and Y shape 60° butt joint were measured after the gas metal arc welding (GMAW) test.The tensile strength of the weld was higher than 700 Mpa.Both in the fusion zone (FZ) and HAZ for butt joint,the impact toughness was much higher than 27 J,either at room temperature or at -20 ℃,indicating good low temperature impact ductility of the weld of TRIP 600 steel.In addition,welding crack susceptibility tests revealed that weldments were free of surface crack and other imperfection.All experimental results of this steel showed fairly good weldability.For application,the crossmember in automobile made of this steel exhibited excellent weldability,and fatigue and durability tests were also accomplished for crossmember assembly.

  13. Protective effect of recombinant human IL-1Ra on CCl_4-induced acute liver injury in mice

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To evaluate the effects of positive regulation of recombinant human interleukin 1 receptor antagonist (rhIL-1Ra) on hepatic tissue recovery in acute liver injury in mice induced by carbon tetrachloride (CCl 4 ). METHODS: Acute liver damage was induced by injecting 8-wk-old mice with CCl 4 1 mL/kg (1:3 dilution in corn oil) intraperitoneally (ip). Survival after liver failure was assessed by injecting 8-wk-old mice with a lethal dose of CCl 4 2.6 mL/kg (1:1 dilution in corn oil) ip. Mice were subcutaneo...

  14. Using hydrocarbon as a carbon source for synthesis of carbon nanotube by electric field induced needle-pulsed plasma

    International Nuclear Information System (INIS)

    In this work different hydrocarbons are used as the carbon source, in the production of carbon nanotubes (CNTs) and nano onions. An electric field induced needle pulse arc-discharge reactor is used. The influence of starting carbon on the synthesis of CNTs is investigated. The production efficiency is compared for Acetone, Isopropanol and Naphthalene as simple hydrocarbons. The hydrocarbons are preheated and then pretreated by electric field before being exposed to plasma. The hydrocarbon vapor is injected into plasma through a graphite spout in the cathode assembly. The pulsed plasma takes place between two graphite rods while a strong electric field has been already established alongside the electrodes. The pulse width is 0.3 μs. Mechanism of precursor decomposition is discussed by describing three forms of energy that are utilized to disintegrate the precursor molecules: thermal energy, electric field and kinetic energy of plasma. Molecular polarity of a hydrocarbon is one of the reasons for choosing carbon raw material as a precursor in an electric field induced low power pulsed-plasma. The results show that in order to obtain high quality carbon nanotubes, Acetone is preferred to Isopropanol and Naphthalene. Scanning probe microscopy techniques are used to investigate the products. - Highlights: • We synthesized CNTs (carbon nano tubes) by needle pulsed plasma. • We use different hydrocarbons as carbon source in the production of CNTs. • We investigated the influence of starting carbon on the synthesis of CNTs. • Thermal energy, electric field and kinetic energy are used to break carbon bonds. • Polar hydrocarbon molecules are more efficient than nonpolar ones in production

  15. Carbon/Nitrogen Imbalance Associated with Drought-Induced Leaf Senescence in Sorghum bicolor

    OpenAIRE

    Daoqian Chen; Shiwen Wang; Binglin Xiong; Beibei Cao; Xiping Deng

    2015-01-01

    Drought stress triggers mature leaf senescence, which supports plant survival and remobilization of nutrients; yet leaf senescence also critically decreases post-drought crop yield. Drought generally results in carbon/nitrogen imbalance, which is reflected in the increased carbon:nitrogen (C:N) ratio in mature leaves, and which has been shown to be involved in inducing leaf senescence under normal growth conditions. Yet the involvement of the carbon/nitrogen balance in regulation of drought-i...

  16. Carbon-induced extreme ultraviolet reflectance loss characterized using visible-light ellipsometry

    NARCIS (Netherlands)

    Chen, J. Q.; E. Louis,; Wormeester, H.; Harmsen, R.; van de Kruijs, R.; Lee, C. J.; van Schaik, W.; F. Bijkerk,

    2011-01-01

    Carbon deposition on extreme ultraviolet (EUV) optics was observed due to photon-induced dissociation of hydrocarbons in a EUV lithography environment. The reflectance loss of the multilayer mirror is determined by the carbon layer thickness and density. To study the influence of various forms of ca

  17. Characterization of flow-induced structures in carbon nanotube suspensions

    Science.gov (United States)

    Khalkhal, Fatemeh

    Carbon nanotubes (CNTs) are fibre-like nano-particles with many different applications. Due to their high specific surface area, high electric current density, thermal stability and excellent mechanical properties, they are used to reinforce physical properties of polymer matrices. The macroscopic properties of suspensions are inherited from their properties at micron and sub-micron scales. The suspensions structure can be easily influenced by many parameters such as the extent of external shear forces, the suspension concentration, temperature, the particles specifications, etc. This makes the study of the suspension structure a very challenging task and has been the subject of interest to many researchers. In this thesis, the structure of a model carbon nanotube suspension dispersed in an epoxy is studied by employing a set of rheological methods, scaling and fractal theories and a structural thixotropic model. The effect of flow history on linear viscoelastic properties of suspensions and the evolution of structure upon cessation of shear flow has been studied over a wide range of pre-shearing rates, concentration and temperature. The results of these analyses are as follows. The effect of flow history is more pronounced on the suspensions structure in dilute and semi-dilute concentration regimes. By pre-shearing at low rates, more inter-particle entanglements were induced, which resulted in reduction of rheological percolation thresholds. After cessation of shear flow, for dilute and semi-dilute suspensions, the formed metastable structures were distinguishable by different storage moduli, which were inversely related to the rate of pre-shearing. However, for the concentrated suspensions, the formed metastable structures had an approximately equal storage modulus regardless of the rate of the applied pre-shearing. It was shown that the rate of formation of these metastable structures was enhanced by increasing concentration. Furthermore, the rate of structure

  18. Hepatoprotective activity of cinnamon ethanolic extract against CCl4-induced liver injury in rats

    OpenAIRE

    Bazargan, Maryam; Eidi, Akram; MORTAZAVI, Pejman; Zaringalam, Jalal

    2012-01-01

    The inner bark of cinnamon (Cinnamomum zeylanicum L.) is commonly used as a spice and has also been widely employed in the treatment and prevention of disease. The aim of the present study is to evaluate the protective effect of cinnamon bark extract against carbon tetrachloride (CCl4)-induced liver damage in male Wistar rats. Administration with cinnamon extracts (0.01, 0.05 and 0.1 g/kg) for 28 days significantly reduced the impact of CCl4 toxicity on the serum markers of liver damage, ...

  19. Carbon Sources for Yeast Growth as a Precondition of Hydrogen Peroxide Induced Hormetic Phenotype.

    Science.gov (United States)

    Vasylkovska, Ruslana; Petriv, Natalia; Semchyshyn, Halyna

    2015-01-01

    Hormesis is a phenomenon of particular interest in biology, medicine, pharmacology, and toxicology. In this study, we investigated the relationship between H2O2-induced hormetic response in S. cerevisiae and carbon sources in yeast growth medium. In general, our data indicate that (i) hydrogen peroxide induces hormesis in a concentration-dependent manner; (ii) the effect of hydrogen peroxide on yeast reproductive ability depends on the type of carbon substrate in growth medium; and (iii) metabolic and growth rates as well as catalase activity play an important role in H2O2-induced hormetic response in yeast. PMID:26843865

  20. Carbon Sources for Yeast Growth as a Precondition of Hydrogen Peroxide Induced Hormetic Phenotype

    Directory of Open Access Journals (Sweden)

    Ruslana Vasylkovska

    2015-01-01

    Full Text Available Hormesis is a phenomenon of particular interest in biology, medicine, pharmacology, and toxicology. In this study, we investigated the relationship between H2O2-induced hormetic response in S. cerevisiae and carbon sources in yeast growth medium. In general, our data indicate that (i hydrogen peroxide induces hormesis in a concentration-dependent manner; (ii the effect of hydrogen peroxide on yeast reproductive ability depends on the type of carbon substrate in growth medium; and (iii metabolic and growth rates as well as catalase activity play an important role in H2O2-induced hormetic response in yeast.

  1. Natural and Human-induced Disturbances and Their Impacts on Forest Carbon Budgets in North America

    Science.gov (United States)

    Pan, Y.; Birdsey, R.; Chen, J. M.; McCullough, K.; Zhang, F.

    2014-12-01

    Natural and human-induced disturbances have profound impacts on forest carbon dynamics, and may cause the greatest uncertainty in estimating forest carbon budgets. In North America, three countries show very different forest disturbance patterns: Canadian forests are dominated by natural disturbances such as wildfires and insect outbreaks; forests of Mexico are more affected by human-induced land disturbances such as land-use change; while US forests are equally affected by human-induced and natural disturbances. As human-induced disturbances are closely linked to socioeconomic factors, natural disturbances are usually viewed as a natural process in forests and have equilibrium impacts on forests over the long run. However, with climate change and related changes in natural disturbance regimes in terms of frequency, intensity and scale, there are now fundamental changes in the nature of the impact of natural disturbances on forest carbon dynamics and even greater uncertainty about forest carbon budgets and feedbacks to the atmosphere and climate. In this study, we synthesize disturbance information for North America based on existing remote-sensing products, ground-based observations and modeling studies, evaluating impacts of disturbances on forest carbon budgets that are relevant to disturbance types, scales, frequency and intensity. The work represents the initial step of a more ambitious project tackling this research challenge for North America that crosses a broad climate gradient and diverse socioeconomic entities. The goal is to ultimately improve the estimates of forest carbon budgets and their potential for climate mitigation under changing environments.

  2. Chicory (Cichorium intybus L.) Root Extract Regulates the Oxidative Status and Antioxidant Gene Transcripts in CCl4-Induced Hepatotoxicity

    OpenAIRE

    El-Sayed, Yasser S.; Lebda, Mohamed A.; Mohammed Hassinin; Neoman, Saad A.

    2015-01-01

    The ability of Cichorium intybus root extract (chicory extract) to protect against carbon tetrachloride (CCl4)-induced oxidative stress and hepatotoxicity was evaluated in male rats. The rats were divided into four groups according to treatment: saline (control); chicory extract (100 mg/kg body weight daily, given orally for 2 weeks); CCl4 (1 ml/kg body weight by intraperitoneal injection for 2 consecutive days only); or chicory extract (100 mg/kg body weight daily for 2 weeks) + CCl4 injecti...

  3. Significance of erosion-induced carbon fluxes in the carbon balance of a Mediterranean catchment

    Science.gov (United States)

    Nadeu, Elisabet; de Vente, Joris; Boix-Fayos, Carolina

    2014-05-01

    Large uncertainties surround our knowledge of the processes through which carbon (C) sequestration takes place in terrestrial ecosystems. Nevertheless, terrestrial ecosystems could be capturing up to one fourth of the CO2 that is emitted annually to the atmosphere from the burning of fossil fuels and land use changes. Soils are the third largest C reservoir in the C cycle, storing around 1500 Gt of C. Over the last decades, geomorphologists and soil scientists have claimed the role of soil erosion within the C cycle and its potential contribution to the terrestrial C sink. In order to assess the impact of soil erosion on the C cycle, however, an understanding and quantification of the impact of soil erosion on soil C stocks is needed. This implies quantifying lateral and vertical C fluxes associated to detachment, transport and deposition of soil and sediment at different spatial scales. As an example, we present a C budget for a mountainous catchment in south-eastern Spain for a 28 year study period during which the catchment underwent significant land use changes and hydrological correction works (i.e. check-dam construction and reforestations). We quantified lateral C fluxes induced by soil erosion processes and closed a soil/sediment C budget by combining field measurements and numerical modeling. In addition, correlation analysis was conducted between catchment properties (topographic, land use, lithology) and measured C deposition rates to understand the controlling factors on C yield (export) and C concentration in sediments. The results showed that the highest C yields (associated to high sediment yields) were found in subcatchments dominated by soft lithologies and high drainage densities. On the other hand, C concentration in deposited sediments was higher in areas dominated by forest cover, and presented high variability in those parts of the catchment with smoother slopes. Overall, we estimated that around 4000 Mg of C were mobilized from the catchment

  4. Carbon monoxide-induced reduction and healing of graphene oxide

    NARCIS (Netherlands)

    Narayanan, B.; Weeks, S. L.; Jariwala, B. N.; Macco, B.; Weber, J.; Rathi, S. J.; M. C. M. van de Sanden,; Sutter, P.; Agarwal, S.; Ciobanu, C. V.

    2013-01-01

    Graphene oxide holds promise as a carbon-based nanomaterial that can be produced inexpensively in large quantities. However, its structural and electrical properties remain far from those of the graphene sheets obtained by mechanical exfoliation or by chemical vapor deposition unless efficient reduc

  5. Fabrication of micro carbon pillar by laser-induced chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    周健; 罗迎社; 李立君; 钟琦文; 李新华; 殷水平

    2008-01-01

    Argon ion laser was used as the induced light source and ethane(C2H4) was selected as the precursor gas,in the variety ranges of laser power from 0.5 W to 4.5 W and the pressure of the precursor gas from 225×133.3 Pa to 680×133.3 Pa,the experiments of laser induced chemical vapor deposition were proceeded for fabrication of micro carbon pillar.In the experiments,the influences of power of laser and pressure of work gas on the diameter and length of micro carbon pillar were investigated,the variety on averaged growth rate of carbon pillar with the laser irradiation time and moving speed of focus was discussed.Based on experiment data,the micro carbon pillar with an aspect ratio of over 500 was built through the method of moving the focus.

  6. Ion-irradiation-induced defects in bundles of carbon nanotubes

    CERN Document Server

    Salonen, E; Nordlund, K

    2002-01-01

    We study the structure and formation yields of atomic-scale defects produced by low-dose Ar ion irradiation in bundles of single-wall carbon nanotubes. For this, we employ empirical potential molecular dynamics and simulate ion impact events over an energy range of 100-1000 eV. We show that the most common defects produced at all energies are vacancies on nanotube walls, which at low temperatures are metastable but long-lived defects. We further calculate the spatial distribution of the defects, which proved to be highly non-uniform. We also show that ion irradiation gives rise to the formations of inter-tube covalent bonds mediated by carbon recoils and nanotube lattice distortions due to dangling bond saturation. The number of inter-tube links, as well as the overall damage, linearly grows with the energy of incident ions.

  7. Carbonate biomineralization induced by soil bacterium Bacillus megaterium

    Science.gov (United States)

    Lian, Bin; Hu, Qiaona; Chen, Jun; Ji, Junfeng; Teng, H. Henry

    2006-11-01

    Biogenic carbonates spawned from microbial activities are common occurrences in soils. Here, we investigate the carbonate biomineralization mediated by the bacterium Bacillus megaterium, a dominant strain separated from a loess profile in China. Upon completing bacterial cultivation, the ensuring products are centrifuged, and the resultant supernatant and the concentrated bacterial sludge as well as the un-separated culture are added separately into a Ca-CO 3 containing solution for crystallization experiments. Results of XRD and SEM analysis indicate that calcite is the dominant mineral phase formed when the bacteria are present. When the supernatant alone is used, however, a significant portion of vaterite is also precipitated. Experimental results further reveal that the bacteria have a strong tendency to colonize the center area of the calcite {1 0 1¯ 4} faces. Observed crystal morphology suggests that the bacterial colony may promote the growth normal to each individual {1 0 1¯ 4} face of calcite when the cell concentration is high, but may retard it or even cause dissolution of the immediate substrate surfaces when the concentration is low. SEM images taken at earlier stages of the crystallization experiments demonstrate the nucleation of calcite on the bacterial cell walls but do not show obvious morphological changes on the nanometer- to submicron-sized nuclei. δ 13C measurements unveil that the crystals grown in the presence of bacteria are further enriched in the heavy carbon isotope, implying that the bacterial metabolism may not be the carbon sources for the mineralization. Based upon these findings, we propose a mechanism for the B. megaterium mediated calcite mineralization and conclude that the whole process involves epi- and inter-cellular growth in the local microenvironments whose conditions may be controlled by cell sequestration and proton pumping during bacterial respiration.

  8. Carbon Monoxide Suppresses Bleomycin-Induced Lung Fibrosis

    OpenAIRE

    Zhou, Zhihong; Song, Ruiping; Fattman, Cheryl L.; Greenhill, Sara; Alber, Sean; Oury, Tim D.; Augustine M K Choi; Morse, Danielle

    2005-01-01

    Idiopathic pulmonary fibrosis is an incurable fibrosing disorder that progresses relentlessly to respiratory failure. We hypothesized that a product of heme oxygenase activity, carbon monoxide (CO), may have anti-fibrotic effects. To test this hypothesis, mice treated with intratracheal bleomycin were exposed to low-concentration inhaled CO or ambient air. Lungs of mice treated with CO had significantly lower hydroxyproline accumulation than controls. Fibroblast proliferation, thought to play...

  9. Argon laser induced changes to the carbonate content of enamel

    International Nuclear Information System (INIS)

    Argon laser irradiation can be used to cure orthodontic brackets onto teeth in significantly less time than conventional curing lights. In addition, it has been shown that the argon laser seems to impart a demineralization resistance to the enamel. The purpose of this study was to use surface science techniques to ascertain if this demineralization resistance is possibly a result of a decrease in the carbonate content of enamel. Eleven mandibular third molars previously scheduled for extraction were collected and used in the present study. The teeth were sectioned in two and randomly assigned to either the argon laser (457-502 nm; 250 mW cm-2) or the control (no treatment) group. The sections assigned to the argon laser group were cured for 10 s and analyzed. To exaggerate any potential changes the experimental sections were then exposed to a further 110 s of argon laser irradiation. Surface analysis was performed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The results showed no statistically significant change in the carbonate content of enamel after argon laser irradiation (p > 0.05). Thus, it is suggested that any demineralization resistance imparted to the enamel surface by argon laser irradiation is not due to alterations in carbonate content.

  10. Hepatic injury induces contrasting response in liver and kidney to chemicals that are metabolically activated: Role of male sex hormone

    International Nuclear Information System (INIS)

    Injury to liver, resulting in loss of its normal physiological/biochemical functions, may adversely affect a secondary organ. We examined the response of the liver and kidney to chemical substances that require metabolic activation for their toxicities in mice with a preceding liver injury. Carbon tetrachloride treatment 24 h prior to a challenging dose of carbon tetrachloride or acetaminophen decreased the resulting hepatotoxicity both in male and female mice as determined by histopathological examination and increases in serum enzyme activities. In contrast, the renal toxicity of the challenging toxicants was elevated markedly in male, but not in female mice. Partial hepatectomy also induced similar changes in the hepatotoxicity and nephrotoxicity of a challenging toxicant, suggesting that the contrasting response of male liver and kidney was associated with the reduction of the hepatic metabolizing capacity. Carbon tetrachloride pretreatment or partial hepatectomy decreased the hepatic xenobiotic-metabolizing enzyme activities in both sexes but elevated the renal p-nitrophenol hydroxylase, p-nitroanisole O-demethylase and aminopyrine N-demethylase activities significantly only in male mice. Increases in Cyp2e1 and Cyp2b expression were also evident in male kidney. Castration of males or testosterone administration to females diminished the sex-related differences in the renal response to an acute liver injury. The results indicate that reduction of the hepatic metabolizing capacity induced by liver injury may render secondary target organs susceptible to chemical substances activated in these organs. This effect may be sex-specific. It is also suggested that an integrated approach should be taken for proper assessment of chemical hazards

  11. Faunal Influences on Fracture-Induced Carbon Flux Dynamics in Dryland Soils

    Science.gov (United States)

    DeCarlo, K. F.; Caylor, K. K.

    2015-12-01

    Organismal activity, in addition to its role in ecological feedbacks, ha the potential to serve as instigators or enhancers of atmospheric and hydrologic fluxes via alterations in soil structural regimes. We investigated the effect of faunally-induced crack morphology on soil carbon dynamics in three dryland soil systems in central Kenya: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer. Results show that faunal influenes play a divergent biomechanical role in bulk soil cracking morphology and topology: macrofauna-induced bioturbation creates shallow, large, well-connected networks relative to those from megaherbivore-induced biocompaction, with the latter showing a "memory" of past drying events through a crack layering effect. These morphologies may further drive differences in soil carbon flux: under dry conditions, bioturbated and control soils show a persistently high and low mean carbon flux, respectively - biocompacted soils suggest a diurnal trend, with daytime lows and nighttime highs comparable to the control and bioturbated soils, respectively. Overall fluxes under wet conditions are considerably higher, but also more variable, though higher mean carbon fluxes are observed in the biocompacted and bioturbated soils. Our results suggest that fracture morphology induced in biocompacted soils may enhance diffusive fluxes that are typical in undisturbed soils to levels that are as high as those from macrofaunal respiration, but that particular physical conditions in fracture morphology and topology may be necessary as a prerequisite.

  12. A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli.

    OpenAIRE

    Guilloton, M B; Lamblin, A F; Kozliak, E I; Gerami-Nejad, M; Tu, C.; Silverman, D.; Anderson, P. M.; Fuchs, J A

    1993-01-01

    Cyanate induces expression of the cyn operon in Escherichia coli. The cyn operon includes the gene cynS, encoding cyanase, which catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. A carbonic anhydrase activity was recently found to be encoded by the cynT gene, the first gene of the cyn operon; it was proposed that carbonic anhydrase prevents depletion of bicarbonate during cyanate decomposition due to loss of CO2 by diffusion out of the cell (M. B. Guilloto...

  13. Measurement and calculation of 238U fission reaction rates induced by neutrons reflected by carbon material

    International Nuclear Information System (INIS)

    To check the data of carbon material reflecting neutrons, the distribution of 238U fission reaction rates induced by D-T fusion neutrons reflected by carbon material was measured by using the small depleted uranium fission chamber and the capturing detector. For comparison, 238U fission rates without carbon material was measured too. The combined standard uncertainty of 238U fission reaction rate is 5.1%-6.4%. The measured results are consistent with the calculated ones with MCNP/4A code and ENDF/B-IV library data in the range of the error

  14. Oscillator-strength distributions for oxygen, carbon dioxide, water, methyl chloride, and carbon tetrachloride

    International Nuclear Information System (INIS)

    New measurements of photoabsorption give oscillator-strength values for the following gases and energy regions: O2, 7.34 to 11.79 eV; CO2, 7.34 to 11.77 eV; H2O, 6.62 to 11.80 eV; CH3CL, 6.14 to 11.25 eV; and CCl4, 6.14 to 11.49 eV. Comparisons are made with some values from the literature

  15. Synthesis of zirconium by zirconium tetrachloride reduction by magnesio-thermia. Experimental study and modelling

    International Nuclear Information System (INIS)

    This work deals with the synthesis of zirconium. The ore is carbo-chlorinated to obtain the tetrachloride which is then purified by selective condensation and extractive distillation. Zirconium tetrachloride is then reduced by magnesium and the pseudo-alloy is obtained according to the global following reaction (Kroll process): ZrCl4 + 2 Mg = 2 MgCl2. By thermodynamics, it has been shown that the volatilization of magnesium chloride and the formation of zirconium sub-chlorides are minimized when the combined effects of temperature and of dilution with argon are limited. With these conditions, the products, essentially zirconium and magnesium chloride, are obtained in equivalence ratio in the magnesio-thermia reaction. The global kinetics of the reduction process has been studied by a thermal gravimetric method. A thermo-balance device has been developed specially for this kinetics study. It runs under a controlled atmosphere and is coupled to a vapor tetrachloride feed unit. The transformation is modelled supposing that the zirconium and magnesium chloride formation result: 1)of the evaporation of magnesium from its liquid phase 2)of the transfer of magnesium and zirconium tetrachloride vapors towards the front of the reaction located in the gaseous phase 3)of the chemical reaction. In the studied conditions, the diffusion is supposed to be the limiting process. The influence of the following parameters: geometry of the reactive zone, temperature, scanning rate of the argon-zirconium tetrachloride mixture, composition of the argon-zirconium tetrachloride mixture has been experimentally studied and confronted with success to the model. (O.M.)

  16. Modeling electrostatically induced collapse transitions in carbon nanotubes.

    Science.gov (United States)

    Shklyaev, Oleg E; Mockensturm, Eric; Crespi, Vincent H

    2011-04-15

    Molecular dynamics simulations demonstrate how a mechanically bistable single-walled carbon nanotube can act as a variable-shaped capacitor. If the voltage is tuned so that collapsed and inflated states are degenerate, the tube's susceptibility to diverse external stimuli--temperature, voltage, trapped atoms--diverges following a universal curve, yielding an exceptionally sensitive sensor or actuator. The boundary between collapsed and inflated states can shift hundreds of angstroms in response to a single gas atom inside the tube. Several potential nanoelectromechanical devices could be based on this electrically tuned crossover between near-degenerate collapsed and inflated configurations.

  17. Laser-induced production of large carbon-based toroids

    International Nuclear Information System (INIS)

    We report on the production of large carbon-based toroids (CBTs) from fullerenes. The process involves two-step laser irradiation of a mixed fullerene target (76% C60, 22% C70). Transmission electron microscopy (TEM) clearly identifies toroidal-shaped structures as well as Q-shaped constructs. The typical diameters of the CBTs are ∼0.2-0.3 μm with tubular diameters of ∼50-100 nm, but toroids as wide as 0.5 μm are observed making them nanostructures on the verge of being microstructures

  18. Kinetic equation for the reaction of titanium tetrachloride with hydride functional groups of diamond

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, A.B.; Smirnov, E.P.

    1989-02-01

    This work is devoted to the study of the kinetics of the reaction of titanium tetrachloride with the hydride functional groups of diamond. The research was performed on submicron powders of ASM 0.7/0.3 grade synthetic diamond with a specific surface area of 8.0 m/sup 2//g as measured from the adsorption of nitrogen. The reaction was carried out in a flow-through quartz reactor in a flow of dry He. The content of the titanium in the samples was determined by a photocolorimetric method. A kinetic equation for the reaction of diamond with titanium tetrachloride was found on the basis of a statistical approach.

  19. Carbonation acceleration of calcium hydroxide nanoparticles: induced by yeast fermentation

    Science.gov (United States)

    Lopez-Arce, Paula; Zornoza-Indart, Ainara

    2015-09-01

    Carbonation of Ca(OH)2 nanoparticles and consolidation of limestone are accelerated by high humidity and a yeast fermentation system that supplies a saturated atmosphere on CO2, H2O vapor and ethanol during 28 days. Nanoparticles were analyzed by X-ray diffraction and differential thermal analyses with thermogravimetry. Spectrophotometry, scanning electron microscopy analyses, and hydric and mechanical tests were also performed in stones specimens. Samples exposed to the yeast environment achieve 100 % relative CaCO3 yield, whereas at high humidity but without the yeast and under laboratory environment, relative yields of 95 % CaCO3 and 15 % CaCO3 are, respectively, reached, with white crusts and glazing left on the stone surfaces when the nanoparticles are applied at a concentration of 25 g/l. The largest increase in the drilling resistance and surface hardness values with slight increase in the capillarity absorption and desorption coefficients and with lesser stone color changes are produced at a concentration of 5 g/l, in the yeast system environment. This especially happens in stone specimens initially with bimodal pore size distributions, more amounts of pores with diameters between 0.1 and 1 µm, higher open porosity values and faster capillary coefficients. An inexpensive and reliable method based on water and yeast-sugar solution is presented to speed up carbonation of Ca(OH)2 nanoparticles used as a consolidating product to improve the mechanical properties of decayed limestone from archaeological and architectural heritage.

  20. Characterization of carbon ion implantation induced graded microstructure and phase transformation in stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel 316L is ion implanted by carbon with implantation fluences of 1.2 × 1017 ions-cm− 2, 2.4 × 1017 ions-cm− 2, and 4.8 × 1017 ions-cm− 2. The ion implantation induced graded microstructure and phase transformation in stainless steel is investigated by X-ray diffraction, X-ray photoelectron spectroscopy and high resolution transmission electron microscopy. The corrosion resistance is evaluated by potentiodynamic test. It is found that the initial phase is austenite with a small amount of ferrite. After low fluence carbon ion implantation, an amorphous layer and ferrite phase enriched region underneath are formed. Nanophase particles precipitate from the amorphous layer due to energy minimization and irradiation at larger ion implantation fluence. The morphology of the precipitated nanophase particles changes from circular to dumbbell-like with increasing implantation fluence. The corrosion resistance of stainless steel is enhanced by the formation of amorphous layer and graphitic solid state carbon after carbon ion implantation. - Highlights: • Carbon implantation leads to phase transformation from austenite to ferrite. • The passive film on SS316L becomes thinner after carbon ion implantation. • An amorphous layer is formed by carbon ion implantation. • Nanophase precipitate from amorphous layer at higher ion implantation fluence. • Corrosion resistance of SS316L is improved by carbon implantation

  1. A climate-change policy induced shift from innovations in carbon-energy production to carbon-energy savings

    International Nuclear Information System (INIS)

    We develop an endogenous growth model with capital, labor and carbon-energy as production factors and three technology variables that measure accumulated innovations for carbon-energy production, carbon-energy savings, and neutral growth. All markets are complete and perfect, except for research, for which we assume that the marginal social benefits exceed the marginal private benefits by factor four. The model constants are calibrated so that the model reproduces the relevant global trends over the 1970-2000 period. The model contains a simple climate module, and is used to assess the impact of Induced Technological Change (ITC) for a policy that aims at a maximum level of atmospheric CO2 concentration (450 ppmv). ITC is shown to reduce the required carbon tax by more than a factor 2, and to reduce costs of such a policy by half. When we do not constrain aggregate R and D expenditures to benchmark levels, costs are further reduced. Numerical simulations show that knowledge accumulation shifts from energy production to energy saving technology. We discuss reasons for differences between our results and earlier results reported in the literature. (author)

  2. Impact of atmospheric and terrestrial CO2 feedbacks on fertilization-induced marine carbon uptake

    Directory of Open Access Journals (Sweden)

    A. Oschlies

    2009-04-01

    Full Text Available The sensitivity of oceanic CO2 uptake to alterations in the marine biological carbon pump, such as brought about by natural or purposeful ocean fertilization, has repeatedly been investigated by studies employing numerical biogeochemical ocean models. It is shown here that the results of such ocean-centered studies are very sensitive to the assumption made about the response of the carbon reservoirs on the atmospheric side of the sea surface. Assumptions made include prescribed atmospheric pCO2, an interactive atmospheric CO2 pool exchanging carbon with the ocean but not with the terrestrial biosphere, and an interactive atmosphere that exchanges carbon with both oceanic and terrestrial carbon pools. The impact of these assumptions on simulated annual to millennial oceanic carbon uptake is investigated for a hypothetical increase in the C:N ratio of the biological pump and for an idealized enhancement of phytoplankton growth. Compared to simulations with interactive atmosphere, using prescribed atmospheric pCO2 overestimates the sensitivity of the oceanic CO2 uptake to changes in the biological pump, by about 2%, 25%, 100%, and >500% on annual, decadal, centennial, and millennial timescales, respectively. Adding an interactive terrestrial carbon pool to the atmosphere-ocean model system has a small effect on annual timescales, but increases the simulated fertilization-induced oceanic carbon uptake by about 4%, 50%, and 100% on decadal, centennial, and millennial timescales, respectively. On longer than decadal timescales, a substantial fraction of oceanic carbon uptake induced by natural or purposeful ocean fertilization may not come from the atmosphere but from the terrestrial biosphere.

  3. Soil carbonation processes as evidence of tillage-induced erosion

    OpenAIRE

    Marques da Silva, José Rafael; Alexandre, C

    2004-01-01

    Tillage-induced soil erosion or redistribution increases spatial variation of several soil properties and often reduces the productive capacity of soil resources. Our objectives were to identify the extent of this type of erosion by observing the changes in soil morphological properties in the field and analysing its possible effects on soil productivity. The study was initiated in 2001 and conducted at two irrigated sites located approximately at Terena, Alandrol, 80 km east of Évor...

  4. Cross sections and kinematics of proton induced fragmentation of carbon

    Energy Technology Data Exchange (ETDEWEB)

    Streibel, T.; Roecher, H.; Huentrup, G.; Heinrich, W. [Siegen Univ. (Germany). Dept. of Physics

    1997-09-01

    Charge changing fragmentation cross sections for C at a proton energy of about 70 MeV were measured. The discrepancies between measurement and model predictions indicate the necessity of further investigations. We have also measured distributions of fragment emission angles which can be described using a model with a momentum transfer to the fragmenting nucleus. The developed model leads to predictions for momentum distributions of proton induced target fragments of C at small energies. (orig.)

  5. Effects of Strain-Induced Crystallization on Mechanical Properties of Elastomeric Composites Containing Carbon Nanotubes and Carbon Black

    International Nuclear Information System (INIS)

    The effects of strain-induced crystallization (SIC) on the mechanical properties of elastomeric composites as functions of extension ratio (λ), multi walled carbon nanotube (CNT) content, and carbon black (CB) content are investigated. The differential scanning calorimetry (DSC) analysis shows that the degree of crystallinity increases with the increase in the CB and CNT content. As λ increases, the glass transition temperature (Tg) of the composites increases, and the latent heat of crystallization (LHc) of the composites is maximum at λ=1.5. It is found that the mechanical properties have a linear relation with LHc, depending on the CNT content. According to the TGA (thermogravimetric analysis), the weight loss of the composite matrix is 94.3% and the weight of the composites decreases with the filler content. The ratio of tensile modulus (Ecomp/ Ematrix) is higher than that of tensile strength (σcomp/ σmatrix) because of the CNT orientation inside the elastomeric composites

  6. Drying induced upright sliding and reorganization of carbon nanotube arrays

    Energy Technology Data Exchange (ETDEWEB)

    Li Qingwen [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); De Paula, Raymond [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Zhang Xiefei [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Zheng Lianxi [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Arendt, Paul N [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mueller, Fred M [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Zhu, Y T [Materials Physics and Applications Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Tu Yi [CVD-First Nano, 1860 Smithtown Avenue, Ronkonkoma, NY 11779 (United States)

    2006-09-28

    Driven by capillary force, wet carbon nanotube (CNT) arrays have been found to reorganize into cellular structures upon drying. During the reorganization process, individual CNTs are firmly attached to the substrate and have to lie down on the substrate at cell bottoms, forming closed cells. Here we demonstrate that by modifying catalyst structures, the adhesion of CNTs to the substrate can be weakened. Upon drying such CNT arrays, CNTs may slide away from their original sites on the surface and self-assemble into cellular patterns with bottoms open. It is also found that the sliding distance of CNTs increases with array height, and drying millimetre tall arrays leads to the sliding of CNTs over a few hundred micrometres and the eventual self-assembly into discrete islands. By introducing regular vacancies in CNT arrays, CNTs may be manipulated into different patterns.

  7. Drying induced upright sliding and reorganization of carbon nanotube arrays

    International Nuclear Information System (INIS)

    Driven by capillary force, wet carbon nanotube (CNT) arrays have been found to reorganize into cellular structures upon drying. During the reorganization process, individual CNTs are firmly attached to the substrate and have to lie down on the substrate at cell bottoms, forming closed cells. Here we demonstrate that by modifying catalyst structures, the adhesion of CNTs to the substrate can be weakened. Upon drying such CNT arrays, CNTs may slide away from their original sites on the surface and self-assemble into cellular patterns with bottoms open. It is also found that the sliding distance of CNTs increases with array height, and drying millimetre tall arrays leads to the sliding of CNTs over a few hundred micrometres and the eventual self-assembly into discrete islands. By introducing regular vacancies in CNT arrays, CNTs may be manipulated into different patterns

  8. UV-induced carbon monoxide emission from sand and living vegetation

    DEFF Research Database (Denmark)

    Bruhn, Dan; Albert, Kristian Rost; Mikkelsen, Teis Nørgaard;

    2012-01-01

    The global burden of carbon monoxide, CO, is rather uncertain. In this paper we address the potential of UV-induced CO emission by terrestrial surfaces. Real-time measurements of [CO] were made with a cavity enhanced laser connected in closed loop to either an ecosystem chamber or a leaf scale...

  9. Current-induced changes of migration energy barriers in graphene and carbon nanotubes

    KAUST Repository

    Obodo, Tobechukwu Joshua

    2016-04-29

    An electron current can move atoms in a nanoscale device with important consequences for the device operation and breakdown. We perform first principles calculations aimed at evaluating the possibility of changing the energy barriers for atom migration in carbon-based systems. In particular, we consider the migration of adatoms and defects in graphene and carbon nanotubes. Although the current-induced forces are large for both the systems, in graphene the force component along the migration path is small and therefore the barrier height is little affected by the current flow. In contrast, the same barrier is significantly reduced in carbon nanotubes as the current increases. Our work also provides a real-system numerical demonstration that current-induced forces within density functional theory are non-conservative. © 2016 The Royal Society of Chemistry.

  10. Frost Induces Respiration and Accelerates Carbon Depletion in Trees

    Science.gov (United States)

    Sperling, Or; Earles, J. Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A.

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0°C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm-3 yr-1 on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics. PMID:26629819

  11. Frost Induces Respiration and Accelerates Carbon Depletion in Trees.

    Directory of Open Access Journals (Sweden)

    Or Sperling

    Full Text Available Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq. cm(-3 yr(-1 on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.

  12. Limited opportunities for management-induced soil carbon storage in New South Wales, Australia.

    Science.gov (United States)

    Wilson, Brian; Lonergan, Vanessa

    2013-04-01

    Soil management has been promoted internationally and in Australia as a means of storing additional soil carbon to offset greenhouse gas emissions (GHG) elsewhere. Despite considerable investment in research in Australia, difficulties with reliable detection and estimation of soil carbon change remain as significant barriers to soil carbon accounting and trading. Here we present examples from an extensive dataset across the diverse production landscapes of New South Wales, Australia generated from both the NSW Statewide Soil Monitoring Program and the National Soil Carbon Research Program. Issues relating to climate, spatial variability, historical and contemporary land-management are highlighted to illustrate the challenges of detecting and estimating management-induced soil carbon change. We further demonstrate that, where it is possible to detect soil carbon change resulting from agricultural management, the quantities stored are unlikely to make a significant contribution to reductions in net greenhouse gas emissions. Historical factors and non-agricultural land-use options are likely to provide more significant potential for long-term soil carbon storage in this environment.

  13. Inorganic carbon acquisition in potentially toxic and non-toxic diatoms: the effect of pH-induced changes in the seawater carbonate chemistry

    DEFF Research Database (Denmark)

    Trimborn, S; Lundholm, Nina; Thoms, S;

    2008-01-01

    The effects of pH-induced changes in seawater carbonate chemistry on inorganic carbon (C-i) acquisition and domoic acid (DA) production were studied in two potentially toxic diatom species, Pseudo-nitzschia multiseries and Nitzschia navis-varingica, and the non-toxic Stellarima stellaris. In vivo...

  14. Human induced impacts on soil organic carbon in southwest Iceland

    Science.gov (United States)

    Gísladóttir, Guðrún; Erlendsson, Egill; Lal, Rattan

    2013-04-01

    The Icelandic environment has been strongly influenced by natural processes during the Holocene. Since settlement in AD 874, the introduction of grazing animals and other land use has drastically affected the natural environment. This includes the diminishing of vegetative cover, which has led to soil exposure and accelerated erosion over large areas, especially when in conjunction with harsh climate. This has specifically impacted processes and properties of volcanic soils (Andosols), which are subject to accelerated erosion by wind and water. While approximately 46% of the land surface in Iceland has sustained continuous vegetation cover, large areas have lost some or all of their soil cover formed during the postglacial era. Elsewhere, remaining soils have sparse or no vegetation cover, thus impairing soil carbon (C) sequestration. Among their multifunctional roles, soils support plant growth, increase soil biotic activity, enhance nutrient storage and strengthen the cycling of water and nutrients. In contrast, soil degradation by accelerated erosion and other processes impairs soil quality, reduces soil structure and depletes the soil organic matter (SOM) pool. Depletion of the SOM pool has also global implications because the terrestrial C pool is the third largest pool and strongly impacts the global C cycle. Erosional-depositional processes may deplete soil organic C (SOC) by erosion and increase by deposition. Some SOC-enriched sediments are redistributed over the landscape, while others are deposited in depression sites and transported into aquatic ecosystems. SOC decomposition processes are severely constrained in some environmental settings and any SOC buried under anaerobic conditions is protected against decomposition. Yet, the impact of the SOC transported by erosional processes and redistributed over the landscape is not fully understood because the variability in its turnover characteristics has not been widely studied. Thus, the fate of C

  15. Gut microbiota dysbiosis is associated with inflammation and bacterial translocation in mice with CCl4-induced fibrosis.

    Directory of Open Access Journals (Sweden)

    Isabel Gómez-Hurtado

    Full Text Available BACKGROUND: Gut is the major source of endogenous bacteria causing infections in advanced cirrhosis. Intestinal barrier dysfunction has been described in cirrhosis and account for an increased bacterial translocation rate. HYPOTHESIS AND AIMS: We hypothesize that microbiota composition may be affected and change along with the induction of experimental cirrhosis, affecting the inflammatory response. ANIMALS AND METHODS: Progressive liver damage was induced in Balb/c mice by weight-controlled oral administration of carbon tetrachloride. Laparotomies were performed at weeks 6, 10, 13 and 16 in a subgroup of treated mice (n = 6/week and control animals (n = 4/week. Liver tissue specimens, mesenteric lymph nodes, intestinal content and blood were collected at laparotomies. Fibrosis grade, pro-fibrogenic genes expression, gut bacterial composition, bacterial translocation, host's specific butyrate-receptor GPR-43 and serum cytokine levels were measured. RESULTS: Expression of pro-fibrogenic markers was significantly increased compared with control animals and correlated with the accumulated dose of carbon tetrachloride. Bacterial translocation episodes were less frequent in control mice than in treated animals. Gram-positive anaerobic Clostridia spp count was decreased in treated mice compared with control animals and with other gut common bacterial species, altering the aerobic/anaerobic ratio. This fact was associated with a decreased gene expression of GPR43 in neutrophils of treated mice and inversely correlated with TNF-alpha and IL-6 up-regulation in serum of treated mice along the study protocol. This pro-inflammatory scenario favoured blood bacterial translocation in treated animals, showing the highest bacterial translocation rate and aerobic/anaerobic ratio at the same weeks. CONCLUSIONS: Gut microbiota alterations are associated with the development of an inflammatory environment, fibrosis progression and bacterial translocation in

  16. Current-induced strength degradation of activated carbon spheres in carbon supercapacitors

    Science.gov (United States)

    Sun, Yuan; Chen, Rong; Lipka, Stephen M.; Yang, Fuqian

    2016-05-01

    Activated carbon microspheres (ACSs), which are prepared using hydrothermal synthesis and ammonia activation, are used as the active materials in the anode and cathode of electric double layer capacitors (EDLCs). The ACS-based EDLCs of symmetrical electrodes exhibit good stability and a high degree of reversibility over 2000 charge-discharge cycles for electric current up to 10 A g-1. The ACSs maintain a nongraphitized carbon structure after over 2000 charge-discharge cycles. Nanoindentation experiments are performed on the ACSs, which are electrochemically cycled in a voltage window of 0-1 V at three electric currents of 0.5, 5, and 10 A g-1. For the same indentation load, both the contact modulus and indentation hardness of the ACSs decrease with the increase of the electric current used in the electrical charging and discharging. These results suggest that there exists strength degradation introduced by the electric current. A larger electric current will cause more strength degradation than a smaller electric current.

  17. Carbon dioxide inhalation induces dose-dependent and age-related negative affectivity.

    Directory of Open Access Journals (Sweden)

    Eric J Griez

    Full Text Available BACKGROUND: Carbon dioxide inhalation is known to induce an emotion similar to spontaneous panic in Panic Disorder patients. The affective response to carbon dioxide in healthy subjects was not clearly characterized yet. METHODOLOGY/PRINCIPAL FINDINGS: Sixty-four healthy subjects underwent a double inhalation of four mixtures containing respectively 0, 9, 17.5 and 35% CO(2 in compressed air, following a double blind, cross-over, randomized design. Affective responses were assessed according to DSM IV criteria for panic, using an Electronic Visual Analogue Scale and the Panic Symptom List. It was demonstrated that carbon dioxide challenges induced a dose dependent negative affect (p<0.0001. This affect was semantically identical to the DSM IV definition of panic. Older individuals were subjectively less sensitive to Carbon Dioxide (p<0.05. CONCLUSIONS/SIGNIFICANCE: CO(2 induced affectivity may lay on a continuum with pathological panic attacks. Consistent with earlier suggestions that panic is a false biological alarm, the affective response to CO(2 may be part of a protective system triggered by suffocation and acute metabolic distress.

  18. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Eto, Shuzo; Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi; Tanaka, Masayoshi Y.

    2014-11-01

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously.

  19. Oxidation of a Single Carbon Monoxide Molecule Manipulated and Induced with a Scanning Tunneling Microscope

    International Nuclear Information System (INIS)

    A carbon monoxide molecule (CO) was positioned with a scanning tunneling microscope (STM) at various distances from an oxygen atom (O) on the Ag(110) surface at 13K. At the closest separation, carbon dioxide (CO2) production was induced by tunneling electrons. Direct reaction of a CO desorbed from the STM tip with an O atom on Ag(110) illustrates another catalytic oxidation mechanism. Inelastic electron tunneling spectroscopy with the STM was used to monitor the vibrations of CO in its different environment

  20. Numerical and experimental studies of the carbon etching in EUV-induced plasma

    CERN Document Server

    Astakhov, D I; Lee, C J; Ivanov, V V; Krivtsun, V M; Yakushev, O; Koshelev, K N; Lopaev, D V; Bijkerk, F

    2015-01-01

    We have used a combination of numerical modeling and experiments to study carbon etching in the presence of a hydrogen plasma. We model the evolution of a low density EUV-induced plasma during and after the EUV pulse to obtain the energy resolved ion fluxes from the plasma to the surface. By relating the computed ion fluxes to the experimentally observed etching rate at various pressures and ion energies, we show that at low pressure and energy, carbon etching is due to chemical sputtering, while at high pressure and energy a reactive ion etching process is likely to dominate.

  1. Interface Induced Carbonate Mineralization: A Fundamental Geochemical Process Relevant to Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    Teng, H. Henry [PI, The George Washington University; Xu, Huifang [Co-PI, University of Wisconsin-Madison

    2013-07-17

    We have approached the long-standing geochemical question why anhydrous high-Mg carbonate minerals (i.e., magnesite and dolomite) cannot be formed at ambient conditions from a new perspective by exploring the formation of MgCO{sub 3} and Mg{sub x}Ca{sub (1-x)}CO{sub 3} in non-aqueous solutions. Data collected from our experiments in this funding period suggest that a fundamental barrier, other than cation hydration, exists that prevents Mg{sup 2+} and CO{sub 3}{sup 2-} ions from forming long-range ordered structures. We propose that this barrier mainly stems from the lattice limitation on the spatial configuration of CO{sub 3} groups in magnesite crystals. On the other hand, the measured higher distribution coefficients of Mg between magnesian calcites formed in the absence and presence of water give us a first direct proof to support and quantify the cation hydration effect.

  2. Inhibition of hypoxia-inducible carbonic anhydrase-IX enhances hexokinase II inhibitor-induced hepatocellular carcinoma cell apoptosis

    OpenAIRE

    Yu, Su-jong; Yoon, Jung-Hwan; Lee, Jeong-Hoon; Myung, Sun-jung; Jang, Eun-sun; Kwak, Min-Sun; Cho, Eun-Ju; Jang, Ja-June; Kim, Yoon-jun; Lee, Hyo-Suk

    2011-01-01

    Aim: The hypoxic condition within large or infiltrative hypovascular tumors produces intracellular acidification, which could activate many signaling pathways and augment cancer cell growth and invasion. Carbonic anhydrase-IX (CA-IX) is an enzyme lowering pH. This study is to examine whether hypoxia induces CA-IX in hepatocellular carcinoma (HCC) cells, and to evaluate its clinical implication in HCC patients. Methods: Human HCC cell lines (Huh-7 and HepG2 cells) were used, and cell growth wa...

  3. Electric anisotropy in high density polyethylene + carbon black composites induced by mechanical deformation

    Energy Technology Data Exchange (ETDEWEB)

    Vigueras-Santiago, E; Hernandez-Lopez, S; Camacho-Lopez, M A; Lara-Sanjuan, O, E-mail: eviguerass@uaemex.m [Laboratorio de Investigacion y Desarrollo de Materiales Avanzados (LIDMA), Facultad de Quimica, UAEM. Paseo Colon esq. con Paseo Tollocan, s/n. C.P. 50000, Toluca (Mexico)

    2009-05-01

    High density polyethylene + carbon black composites with electrical anisotropy was studied. Electrical anisotropy was induced by uniaxial mechanical deformation and injection moulding. We show that anisotropy depends on the carbon black concentration and percentage deformation. Resistivity had the highest anisotropy resistivity around the percolation threshold. Perpendicular resistivity showed two magnitude orders higher than parallel resistivity for injected samples, whereas resistivity showed an inverse behaviour for 100% tensile samples. Both directions were set respect to the deformation axe. Anisotropy could be explained in terms of the molecular deformation (alignment) of the polymer chains as a response of the deformation process originating a redistribution of the carbon black particles in both directions. Alignment of the polymer chains was evidenced by polarized Raman spectroscopy.

  4. From small aromatic molecules to functional nanostructured carbon by pulsed laser-induced photochemical stitching

    Directory of Open Access Journals (Sweden)

    R. R. Gokhale

    2012-06-01

    Full Text Available A novel route employing UV laser pulses (KrF Excimer, 248 nm to cleave small aromatic molecules and stitch the generated free radicals into functional nanostructured forms of carbon is introduced. The process differs distinctly from any strategies wherein the aromatic rings are broken in the primary process. It is demonstrated that this pulsed laser-induced photochemical stitching (PLPS process when applied to routine laboratory solvents (or toxic chemical wastes when discarded Chlorobenzene and o-Dichlorobenzene yields Carbon Nanospheres (CNSs comprising of graphene-like sheets assembled in onion-like configurations. This room temperature process implemented under normal laboratory conditions is versatile and clearly applicable to the whole family of haloaromatic compounds without and with additions of precursors or other nanomaterials. We further bring out its applicability for synthesis of metal-oxide based carbon nanocomposites.

  5. Targeting one carbon metabolism with an antimetabolite disrupts pyrimidine homeostasis and induces nucleotide overflow

    OpenAIRE

    Ser, Zheng; GAO, XIA; Johnson, Christelle; Mehrmohamadi, Mahya; Liu, Xiaojing; Li, SiQi; Locasale, Jason W.

    2016-01-01

    Anti-metabolite agents that affect nucleotide metabolism are frontline chemotherapy agents in several cancers and often successfully target one carbon metabolism. However, the precise mechanisms and resulting determinants of their therapeutic value are unknown. We show that 5-fluorouracil (5-FU), a commonly used anti-metabolite therapeutic with varying efficacy, induces specific alterations to nucleotide metabolism by disrupting pyrimidine homeostasis. An integrative metabolomics analysis of ...

  6. Solvolysis of titanium tetrachloride in non-aqueous media as a method for producing titanium dioxide particles of different morphology

    OpenAIRE

    A. M Nemeryuk; M. M Lylina

    2015-01-01

    The processes of solvolysis of titanium tetrachloride in nonaqueous media were studied. The influence of the conditions of solvolysis on the size and morphology of the particles of titanium dioxide produced have been described.

  7. Continuous versus pulse neutron induced gamma spectroscopy for soil carbon analysis

    International Nuclear Information System (INIS)

    Neutron induced gamma spectra analysis (NGA) provides a means of measuring carbon in large soil volumes without destructive sampling. Calibration of the NGA system must account for system background and the interference of other nuclei on the carbon peak at 4.43 MeV. Accounting for these factors produced measurements in agreement with theoretical considerations. The continuous NGA mode was twice as fast and just as accurate as the pulse mode, thus this mode was preferable for routine soil carbon analysis. - Highlights: • Calibration of the neutron induced gamma analysis system must account for system background and the interference of other nuclei (mainly silicon-28) on the carbon peak at 4.43 MeV. • Spectra measured at a height of 250 cm above the ground could be considered the NGA system background spectrum. • The experimental cascade transition coefficient for silicon-28 (i.e. ratio of 4.50–1.78 MeV gamma ray intensities) agrees well with theoretical calculations. • The NGA continuous working mode halved the measurement time compared to the pulse working mode while retaining the same degree of accuracy

  8. Magnetic-field-induced microstructural features in a high carbon steel during diffusional phase transformation

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiaoxue, E-mail: zhangxiaoxue1213@gmail.com [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Zhang, Yudong, E-mail: yudong.zhang@univ-metz.fr [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Gong, Minglong, E-mail: gml@mail.neuq.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Esling, Claude, E-mail: claude.esling@univ-metz.fr [Laboratoire d' Etude des Microstructures et de Mecanique des Materiaux (LEM3), CNRS UMR 7239, Universite de Lorraine UL 57045 Metz (France); Laboratory of Excellence on Design of Alloy Metals for low-mAss Structures (DAMAS), Universite de Lorraine (France); Zhao, Xiang, E-mail: zhaox@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China); Zuo, Liang, E-mail: lzuo@mail.neu.edu.cn [Key Laboratory for Anisotropy and Texture of Materials (MOE), Northeastern University, Shenyang 110004 (China)

    2012-12-15

    In this work, a high purity, high carbon steel was heat treated without and with a 12-T magnetic field. The microstructural features induced by magnetic field during its diffusion-controlled austenite decomposition were investigated by means of optical microscopy and SEM/EBSD. It is found that the magnetic field increases the amount of the abnormal structure, which is composed of proeutectoid cementite along the prior austenite boundaries and ferrite around it, because magnetic field increases the austenite grain size and promotes the transformation of carbon-depleted austenite to ferrite. No specific orientation relationship between abnormal ferrite and cementite has been found in the non-field- or the field-treated specimens. Magnetic field evidently promotes the spheroidization of pearlite, due to its effect of enhancing carbon diffusion through raising the transformation temperature and its effect of increasing the relative ferrite/cementite interface energy. As magnetic field favors the nucleation of the high magnetization phase-pearlitic ferrite, the occurrence of the P-P2 OR that corresponds to the situation that ferrite nucleates prior to cementite during pearlitic transformation is enhanced by the magnetic field. - Highlights: Black-Right-Pointing-Pointer The field-induced microstructural features in a high carbon steel during diffusional phase transformation has been investigated. Black-Right-Pointing-Pointer Magnetic field increases the amount of the abnormal structure and promotes the spheroidization of pearlite. Black-Right-Pointing-Pointer Magnetic field enhances the occurrence of the P-P2 OR.

  9. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Shuzo, E-mail: eto@criepi.denken.or.jp [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Matsuo, Toyofumi; Matsumura, Takuro; Fujii, Takashi [Central Research Institute of Electric Power Industry, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan); Tanaka, Masayoshi Y. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 2-6-1 Nagasaka, Yokosuka, Kanagawa 240-0196 (Japan)

    2014-11-01

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm{sup 2} within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously. - Highlights: • We estimated the carbonation depth and the apparent diffusion coefficient of chlorine sodium in the reinforced concrete with cracking damage by LIBS. • Two-dimensional profile measurement of the emission intensity in each element was performed to visualize the chloride penetration and the carbonation in the reinforced concrete. • Apparent diffusion coefficient of chlorine and sodium can be estimated using the Fick

  10. Quantitative estimation of carbonation and chloride penetration in reinforced concrete by laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    The penetration profile of chlorine in a reinforced concrete (RC) specimen was determined by laser-induced breakdown spectroscopy (LIBS). The concrete core was prepared from RC beams with cracking damage induced by bending load and salt water spraying. LIBS was performed using a specimen that was obtained by splitting the concrete core, and the line scan of laser pulses gave the two-dimensional emission intensity profiles of 100 × 80 mm2 within one hour. The two-dimensional profile of the emission intensity suggests that the presence of the crack had less effect on the emission intensity when the measurement interval was larger than the crack width. The chlorine emission spectrum was measured without using the buffer gas, which is usually used for chlorine measurement, by collinear double-pulse LIBS. The apparent diffusion coefficient, which is one of the most important parameters for chloride penetration in concrete, was estimated using the depth profile of chlorine emission intensity and Fick's law. The carbonation depth was estimated on the basis of the relationship between carbon and calcium emission intensities. When the carbon emission intensity was statistically higher than the calcium emission intensity at the measurement point, we determined that the point was carbonated. The estimation results were consistent with the spraying test results using phenolphthalein solution. These results suggest that the quantitative estimation by LIBS of carbonation depth and chloride penetration can be performed simultaneously. - Highlights: • We estimated the carbonation depth and the apparent diffusion coefficient of chlorine sodium in the reinforced concrete with cracking damage by LIBS. • Two-dimensional profile measurement of the emission intensity in each element was performed to visualize the chloride penetration and the carbonation in the reinforced concrete. • Apparent diffusion coefficient of chlorine and sodium can be estimated using the Fick’s law

  11. Photo-induced absorption in the pump probe spectroscopy of single-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    Zhu Zi-Peng

    2013-01-01

    Femtosecond pump probe spectroscopy is employed to study the photo-induced absorption feature in the singlewalled carbon nanotube transient spectrum.The two advantages of the experiment,a chirality enriched sample and tuning the pump wavelength to the resonance of a specific nanotube species,greatly facilitate the identification of the photoinduced absorption signal of one tube species.It is found that a photo-induced absorption feature is located at one radial breathing mode to the blue side of the Eii state.This finding prompts a new explanation for the origin of the photoinduced absorption:the transition from the ground state to a phonon coupled state near the Eii state.The explanation suggests a superposition mechanism of the photo-bleach and photo-induced absorption signals,which may serve as a key to the interpretation of the complex pump probe transient spectrum of carbon nanotubes.The finding sheds some light on the understanding of the complex non-radiative relaxation process and the electronic structure of single-walled carbon nanotubes.

  12. The application of spectrum standardization method for carbon analysis in coal using laser-induced breakdown spectroscopy

    CERN Document Server

    Li, Xiongwei; Fu, Yangting; Li, Zheng; Liu, Jianming; Ni, Weidou

    2014-01-01

    Measurements of carbon content in coal using laser-induced breakdown spectroscopy (LIBS) is limited by its low measurement precision and accuracy. A spectrum standardization method was proposed to achieve both reproducible and accurate results for the quantitative analysis of carbon content in coal with LIBS. The proposed method utilized the molecular carbon emissions to compensate the diminution of atomic carbon emission caused by matrix effect. The compensated carbon line intensities were further converted into an assumed standard state with fixed plasma temperature, electron density, and total number density of elemental carbon, which is proportional to its concentration in the coal samples. In addition, in order to obtained better compensation for total carbon number density fluctuations, an iterative algorithm was applied, which is different from our previous standardization calculations. The modified spectrum standardization model was applied to the measurement of carbon content in 24 bituminous coal sa...

  13. Changes in Soil Carbon Pools Induced by Substitution of Plantation for Native Forest

    Institute of Scientific and Technical Information of China (English)

    XU QIUFANG; XU JIANMING

    2003-01-01

    Changes in soil carbon pools under Chinese fir (Cunninghamia lanceolata) and bamboo (Phyllostachyspubescens) plantations substituted for a native forest ( Quereus acutissima, Cyclobalanopsis glauca, Cas-tanopsis sclerophylla, Platycarya strobilacea, Lithocarpus glaber) were studied on the hills with acid parentrock and soils classified as red soils (Ferrisols) in Huzhou, Zhejiang Province of east China. It was foundthat total soil organic carbon (TSOC), easily oxidisable carbon (EOC) and water-soluble organic carbon(WSOC) under bamboo plantation were increased, but microbial biomass carbon (MBC) was decreased. Onthe contrary, Chinese fir induced declines of all fractions of C including TSOC, EOC, WSOC and MBC.The percentages of the active fractions of soil C (EOC and WSOC) were increased in the plantations ascompared to the native broad-leaved forest, but proportions of soil organic C as MBC were decreased. Itcould be concluded that bamboo plantation had a great ability of not only fixing C but also accelerating soilC pool cycle, improving nutrient and microorganism activity; therefore, it is a good ecosystem and could berecommended for wide development. Chinese fir would shrink the soil C pool and deteriorate soil biologicalfertility, so it did not benefit CO2 fixing and land sustainable utilization.

  14. Effects of Strain-Induced Crystallization on Mechanical Properties of Elastomeric Composites Containing Carbon Nanotubes and Carbon Black

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Jong Hwan; Ryu, Sang Ryeoul; Lee, Dong Joo [Yeungnam University, Gyeongsan (Korea, Republic of)

    2011-09-15

    The effects of strain-induced crystallization (SIC) on the mechanical properties of elastomeric composites as functions of extension ratio ({lambda}), multi walled carbon nanotube (CNT) content, and carbon black (CB) content are investigated. The differential scanning calorimetry (DSC) analysis shows that the degree of crystallinity increases with the increase in the CB and CNT content. As {lambda} increases, the glass transition temperature (Tg) of the composites increases, and the latent heat of crystallization (LHc) of the composites is maximum at {lambda}=1.5. It is found that the mechanical properties have a linear relation with LHc, depending on the CNT content. According to the TGA (thermogravimetric analysis), the weight loss of the composite matrix is 94.3% and the weight of the composites decreases with the filler content. The ratio of tensile modulus (E{sub comp}/ E{sub matrix}) is higher than that of tensile strength ({sigma}{sub comp}/ {sigma}{sub matrix}) because of the CNT orientation inside the elastomeric composites.

  15. Ameliorative effect of alkaloid extract of Cyclea peltata (Poir.) Hook. f. & Thoms. roots (ACP) on APAP/CCl4 induced liver toxicity in Wistar rats and in vitro free radical scavenging property

    Institute of Scientific and Technical Information of China (English)

    Varghese Jancy Shine; Somasekharan Nair Rajam Suja; Gangadharan Indira Anuja; Gopan Raj; Sreedharan Nair Rajasekharan

    2014-01-01

    Objective: To evaluate the hepatoprotective and antioxidant properties of alkaloid extract of Cyclea peltata (C. peltata) against paracetamol/carbon tetra chloride induced liver damage in Wistar rats.Methods: In vivo paracetamol/carbon tetrachloride induced liver damage in Wistar rats, in vitro free radical scavenging studies, HPTLC estimation of tetrandrine and direct analysis in real time-mass spectrometry of alkaloid extract of C. peltata were used for the validation. Results: The results showed that pretreatment with alkaloid extract of C. peltata caused significant reduction of serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase, serum alkaline phosphatase, serum cholesterol, liver malondialdehyde levels. The reduced glutathione, catalase, superoxide dismutase levels in liver were increased with alkaloid extract of C. peltata treatment. These results were almost comparable to silymarin and normal control. Histopathological studies also substantiated the biochemical findings. The in vitro hydroxyl, superoxide and DPPH scavenging study of alkaloid extract of C. peltata showed significant free radical scavenging property.Conclusions:The hepatoprotective property of alkaloid extract of C. peltata against paracetamol/carbon tetrachloride may be due the synergistic action of alkaloids especially tetrandrine, fangchinoline through free radical scavenging and thus preventing oxidative stress.

  16. Characterizing petrophysical properties of carbonate rocks using nuclear magnetic resonance and spectral induced polarization

    Science.gov (United States)

    Zhang, Fan; Zhang, Chi; Rankey, Eugene

    2016-04-01

    Unlike sandstones, with well-characterized correlations between porosity and permeability, carbonate rocks are well known for their highly complex petrophysical behaviors due to their intrinsically heterogeneous pore shape, pore size, and pore distributions and connectivity. The characterization of petrophysical properties of carbonate rocks, including rock properties and rock-fluid interactions, remains big challenges. This laboratory study focuses on integrating two geophysical methods: nuclear magnetic resonance (NMR) and spectral induced polarization (SIP) to determine porosity, pore size distribution, and permeability of carbonate rocks. NMR measures the relaxation of hydrogen nuclei at pore scale. Samples with different pore structures saturated by fluids have molecular relaxation responses to the external magnetic field which could generate various NMR signals. Permeability estimation from NMR in siliciclastic rocks is routine, however, is problematic in carbonates. SIP determines complex resistivity of a sample across a wide range of frequency and is sensitive to variations in the properties of solid-fluid and fluid-fluid interfaces in porous media. Previous studies investigated the relationships between permeability and parameters derived from SIP data, but are restricted to narrow lithology range. Our study used carbonate core samples from three depositional environments: tidal zone, shallow marine, and platform/reef margin of an atoll. Samples were fully saturated by water for T2 relaxation measurements and complex conductivity measurements at low frequencies. We compare the pore volume to surface area ratio measured from NMR and SIP and assess the applicability of established petrophysical models to estimate permeability from NMR and SIP data. We hope to build a relationship between NMR signals, SIP responses and petrophysical properties in carbonate rocks. The results could also provide new data and help further understand the unique and complex pore

  17. Stabilization of positive charge on polytetrafluoroethylene electret films treated with titanium-tetrachloride vapor

    Science.gov (United States)

    Rychkov, Dmitry; Gerhard, Reimund

    2011-03-01

    The surface of polytetrafluoroethylene films was treated with titanium-tetrachloride vapor. The treatment was carried out in a flow reactor by means of molecular-layer deposition, a method from the arsenal of chemical nanotechnology. X-ray photoelectron spectroscopy reveals that such a treatment results in considerable changes in the chemical composition at and near the surface of the fluoropolymer film. Both, defluorination and oxidation of the surface were observed. At the same time, samples treated with titanium tetrachloride show a significant enhancement in the thermal stability of the positive homocharge. The thermally stimulated surface-potential-decay curves were observed to shift to higher temperatures by more than 100 °C

  18. Characterizations of Dynamic Strain-induced Transformation in Low Carbon Steel

    Institute of Scientific and Technical Information of China (English)

    Luhan Hao; Mingyue Sun; Namin Xiao; Dianzhong Li

    2012-01-01

    Dynamic strain-induced transformation of the low carbon steel Q(235) at 770℃ and 850℃ leads to fine ferrite grains. The microstructure characterization and mechanism of the fine ferrite grain were studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) technique. The results show that strain-induced microstructure is the mixed microstructure of ferrite and pearlite, with cementite randomly distributed on ferrite grain boundaries and the grains interiors. EBSD images of grain boundaries demonstrate that high angle grain boundaries (HAGBs) are dominant in both of the deformation induced microstructures occurring below and above A(e3) , with only a few low angle grain boundaries (LAGBs) existing in the grain interiors. It implies that the dynamic strain-induced transformation (DSIT) happens above and below A(e3) temperature and has the same phase transition mechanisms. The refinement of ferrite is the cooperative effect of DSIT and continuous dynamic recrystallization (CDRX) of ferrite. Besides, DSIT is deemed as an incomplete carbon diffusion phase transition through the analysis of microstructure and the previous simulated results. The strengths of the Q(235) steel with refined ferrite and pearlite structure get doubled than the initial state without treated by DSIT and the residual stress in the refined structure is partly responsible for the ductility loss.

  19. Effects of carbon dioxide therapy on the healing of acute skin wounds induced on the back of rats

    OpenAIRE

    Maria Vitória Carmo Penhavel; Victor Henrique Tavares Nascimento; Eliana Ferreira Ribeiro Durães; Fabiana Pirani Carneiro; João Batista de Sousa

    2013-01-01

    PURPOSE: To evaluate the healing effect of carbon dioxide therapy on skin wounds induced on the back of rats. METHODS: Sixteen rats underwent excision of a round dermal-epidermal dorsal skin flap of 2.5 cm in diameter. The animals were divided into two groups, as follows: carbon dioxide group - subcutaneous injections of carbon dioxide on the day of operation and at three, six and nine days postoperatively; control group - no postoperative wound treatment. Wounds were photographed on the day ...

  20. Carbon black nanoparticles induce type II epithelial cells to release chemotaxins for alveolar macrophages

    Directory of Open Access Journals (Sweden)

    Donaldson Ken

    2005-12-01

    Full Text Available Abstract Background Alveolar macrophages are a key cell in dealing with particles deposited in the lungs and in determining the subsequent response to that particle exposure. Nanoparticles are considered a potential threat to the lungs and the mechanism of pulmonary response to nanoparticles is currently under intense scrutiny. The type II alveolar epithelial cell has previously been shown to release chemoattractants which can recruit alveolar macrophages to sites of particle deposition. The aim of this study was to assess the responses of a type II epithelial cell line (L-2 to both fine and nanoparticle exposure in terms of secretion of chemotactic substances capable of inducing macrophage migration. Results Exposure of type II cells to carbon black nanoparticles resulted in significant release of macrophage chemoattractant compared to the negative control and to other dusts tested (fine carbon black and TiO2 and nanoparticle TiO2 as measured by macrophage migration towards type II cell conditioned medium. SDS-PAGE analysis of the conditioned medium from particle treated type II cells revealed that a higher number of protein bands were present in the conditioned medium obtained from type II cells treated with nanoparticle carbon black compared to other dusts tested. Size-fractionation of the chemotaxin-rich supernatant determined that the chemoattractants released from the epithelial cells were between 5 and 30 kDa in size. Conclusion The highly toxic nature and reactive surface chemistry of the carbon black nanoparticles has very likely induced the type II cell line to release pro-inflammatory mediators that can potentially induce migration of macrophages. This could aid in the rapid recruitment of inflammatory cells to sites of particle deposition and the subsequent removal of the particles by phagocytic cells such as macrophages and neutrophils. Future studies in this area could focus on the exact identity of the substance(s released by the

  1. Quantification of tsunami-induced flows on a Mediterranean carbonate ramp reveals catastrophic evolution

    Science.gov (United States)

    Slootman, Arnoud; Cartigny, Matthieu J. B.; Moscariello, Andrea; Chiaradia, Massimo; de Boer, Poppe L.

    2016-06-01

    Cool-water carbonates are the dominant limestones in the Mediterranean Basin since the Early Pliocene. Their deposition typically resulted in ramp morphologies due to high rates of resedimentation. Several such fossil carbonate ramps are characterised by a bimodal facies stacking pattern, where background deposition of subaqueous dune and/or tempestite deposits is repeatedly interrupted by anomalously thick sedimentary units, dominated by backset-stratification formed by supercritical flows. A multitude of exceptional triggers (e.g. storms, floods, tsunamis) have been invoked to explain the origin of these supercritical flows, which, in the absence of a quantitative analysis, remains speculative as yet. Here, for the first time, the catastrophic evolution of one such Mediterranean carbonate ramp, on Favignana Island (Italy), is quantified by combining 87Sr/86Sr dating, outcrop-based palaeoflow reconstructions and hydraulic calculations. We demonstrate that rare tsunami-induced flows, occurring on average once every 14 to 35 kyr, lasting a few hours only, deposited the anomalously thick backset-bedded units that form half of the sedimentary record. In between such events, cumulative two years of storm-induced flows deposited the remaining half of the succession by the stacking of subaqueous dunes. The two to four orders of magnitude difference in average recurrence period between the two flow types, and their associated sedimentation rates, emphasises the genetic differences between the two styles of deposition. In terms of sediment transport, the studied carbonate ramp was inactive for at least 99% of the time with gradual progradation during decennial to centennial storm activity. Carbonate ramp evolution attained a catastrophic signature by the contribution of rare tsunamis, producing short-lived, high-energy sediment gravity flows.

  2. Enhanced electric field-induced strain in non-percolative carbon nanopowder/polyurethane composites

    International Nuclear Information System (INIS)

    This study deals with the improvement of electric field-induced thickness strain of polyurethane (PU) elastomer films by carbon black (C) nanopowder incorporation in the polymer matrix. Different carbon volume concentrations-0.5, 0.7, 1 and 1.5%-have been tested. Weak-field dielectric and resistivity measurements revealed that a percolative effect is not induced by carbon filling up to 1.5 vol%. Thickness strain measurements showed that both pure PU and C/PU composite films exhibit similar strain variations which are not governed only by electrostatic forces (Maxwell stress) and/or electrostriction forces. The highest strain amplitude value observed was obtained for 1% C composite thin film (Sa = -7.4% at E = 17.8 kV mm-1). In comparison the highest Sa for pure PU thin film was -6.7% at E = 37.5 kV mm-1). In the case of thick samples, the thickness strain was not enhanced by C loading, which strongly suggests interfacial space charge effects in pure PU film, confirmed by the frequency dependence of strain level

  3. A physiological role for cyanate-induced carbonic anhydrase in Escherichia coli.

    Science.gov (United States)

    Guilloton, M B; Lamblin, A F; Kozliak, E I; Gerami-Nejad, M; Tu, C; Silverman, D; Anderson, P M; Fuchs, J A

    1993-03-01

    Cyanate induces expression of the cyn operon in Escherichia coli. The cyn operon includes the gene cynS, encoding cyanase, which catalyzes the reaction of cyanate with bicarbonate to give ammonia and carbon dioxide. A carbonic anhydrase activity was recently found to be encoded by the cynT gene, the first gene of the cyn operon; it was proposed that carbonic anhydrase prevents depletion of bicarbonate during cyanate decomposition due to loss of CO2 by diffusion out of the cell (M. B. Guilloton, J. J. Korte, A. F. Lamblin, J. A. Fuchs, and P. M. Anderson, J. Biol. Chem. 267:3731-3734, 1992). The function of the product of the third gene of this operon, cynX, is unknown. In the study reported here, the physiological roles of cynT and cynX were investigated by construction of chromosomal mutants in which each of the three genes was rendered inactive. The delta cynT chromosomal mutant expressed an active cyanase but no active carbonic anhydrase. In contrast to the wild-type strain, the growth of the delta cynT strain was inhibited by cyanate, and the mutant strain was unable to degrade cyanate and therefore could not use cyanate as the sole nitrogen source when grown at a partial CO2 pressures (pCO2) of 0.03% (air). At a high pCO2 (3%), however, the delta cynT strain behaved like the wild-type strain; it was significantly less sensitive to the toxic effects of cyanate and could degrade cyanate and use cyanate as the sole nitrogen source for growth. These results are consistent with the proposed function for carbonic anhydrase. The chromosomal mutant carrying cynS::kan expressed induced carbonic anhydrase activity but no active cyanase. The cynS::kan mutant was found to be much less sensitive to cyanate than the delta cynT mutant at a low pCO2, indicating that bicarbonate depletion due to the reaction of bicarbonate with cyanate catalyzed by cyanase is more deleterious to growth than direct inhibition by cyanate. Mutants carrying a nonfunctional cynX gene (cynX::kan and

  4. Use of Activated Carbon in Packaging to Attenuate Formaldehyde-Induced and Formic Acid-Induced Degradation and Reduce Gelatin Cross-Linking in Solid Dosage Forms.

    Science.gov (United States)

    Colgan, Stephen T; Zelesky, Todd C; Chen, Raymond; Likar, Michael D; MacDonald, Bruce C; Hawkins, Joel M; Carroll, Sophia C; Johnson, Gail M; Space, J Sean; Jensen, James F; DeMatteo, Vincent A

    2016-07-01

    Formaldehyde and formic acid are reactive impurities found in commonly used excipients and can be responsible for limiting drug product shelf-life. Described here is the use of activated carbon in drug product packaging to attenuate formaldehyde-induced and formic acid-induced drug degradation in tablets and cross-linking in hard gelatin capsules. Several pharmaceutical products with known or potential vulnerabilities to formaldehyde-induced or formic acid-induced degradation or gelatin cross-linking were subjected to accelerated stability challenges in the presence and absence of activated carbon. The effects of time and storage conditions were determined. For all of the products studied, activated carbon attenuated drug degradation or gelatin cross-linking. This novel use of activated carbon in pharmaceutical packaging may be useful for enhancing the chemical stability of drug products or the dissolution stability of gelatin-containing dosage forms and may allow for the 1) extension of a drug product's shelf-life when the limiting attribute is a degradation product induced by a reactive impurity, 2) marketing of a drug product in hotter and more humid climatic zones than currently supported without the use of activated carbon, and 3) enhanced dissolution stability of products that are vulnerable to gelatin cross-linking.

  5. Use of Activated Carbon in Packaging to Attenuate Formaldehyde-Induced and Formic Acid-Induced Degradation and Reduce Gelatin Cross-Linking in Solid Dosage Forms.

    Science.gov (United States)

    Colgan, Stephen T; Zelesky, Todd C; Chen, Raymond; Likar, Michael D; MacDonald, Bruce C; Hawkins, Joel M; Carroll, Sophia C; Johnson, Gail M; Space, J Sean; Jensen, James F; DeMatteo, Vincent A

    2016-07-01

    Formaldehyde and formic acid are reactive impurities found in commonly used excipients and can be responsible for limiting drug product shelf-life. Described here is the use of activated carbon in drug product packaging to attenuate formaldehyde-induced and formic acid-induced drug degradation in tablets and cross-linking in hard gelatin capsules. Several pharmaceutical products with known or potential vulnerabilities to formaldehyde-induced or formic acid-induced degradation or gelatin cross-linking were subjected to accelerated stability challenges in the presence and absence of activated carbon. The effects of time and storage conditions were determined. For all of the products studied, activated carbon attenuated drug degradation or gelatin cross-linking. This novel use of activated carbon in pharmaceutical packaging may be useful for enhancing the chemical stability of drug products or the dissolution stability of gelatin-containing dosage forms and may allow for the 1) extension of a drug product's shelf-life when the limiting attribute is a degradation product induced by a reactive impurity, 2) marketing of a drug product in hotter and more humid climatic zones than currently supported without the use of activated carbon, and 3) enhanced dissolution stability of products that are vulnerable to gelatin cross-linking. PMID:27262203

  6. Hepatoprotective and cytoprotective properties of Hyptis suaveolens against oxidative stress-induced damage by CCl4 and H2O2

    Institute of Scientific and Technical Information of China (English)

    Hadi Ghaffari; Behrouz Jalali Ghassam; HS Prakash

    2012-01-01

    Objective:To investigate capacity of Hyptis suaveolens (H. suaveolens) methanol extract as an antioxidant to protect against carbon tetrachloride (CCl4)-induced oxidative stress, hepatotoxicity in Albino Wistar rats and cytoprotective effect of hydrogen peroxide (H2O2) induced cell death in HepG2 cell line. Methods: Two different doses of methanol extract of H. suaveolens were evaluated for the hepatoprotective activity against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Animals in Group I: served as control, group II:H. suaveolens (100 mL/kg b.w), group III:H. suaveolens (50 mL/kg b.w) + CCl4 (1 mg/kg), group IV:H. suaveolens (100 mL/kg b.w) + CCl4 (1 mL/kg) and group V: CCl4 (1 mL/kg). Histopathologic changes of liver were also evaluated. Cytotoxicity was also determined by 3, (4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. Results:Oral sigle dose treatment of CCl4 produced a marked elevation in the serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and Lactate dehydrogenase (LDH). Histopathological analysis of the liver of CCl4-induced rats revealed marked liver cell necrosis with inflammatory collections that were conformed to increase in the levels of SOD, GSH, GST, GR and LPO. Treatment with H2O2 significantly induced death of HepG2 cell. Pretreatment with H. suaveolens methanol extract inhibited or attenuated H2O2 induced cytotoxicity. Conclusions: This study shows that H. suaveolens methanol extract can be proposed to protect the liver against CCl4-induced oxidative damage in rats and protect the cells against H2O2-induced oxidative damage in HepG2 cells. The hepatoprotective and cytoprotective effects might be correlated with its antioxidant and free radical scavenger effects.

  7. PROTECTIVE EFFECT OF Solanum Pubescens LINN ON CCL4 INDUCED HEPATOTOXICITY IN ALBINO RATS

    Directory of Open Access Journals (Sweden)

    M.Pushpalatha

    2012-01-01

    Full Text Available Ethanol extract of Solanum pubescens Linn was evaluated for hepato protective and antioxidant activities in rats. The plant extract (500mg/kg/day showed a remarkable hepatoprotective and antioxidant activity against Carbon tetrachloride (CCl4-induced hepatotoxicity as judged from the serum marker enzymes and antioxidant levels in liver tissues. CCl4 induced a significant rise in aspartate amino transferase (AST, alanine amino transferase (ALT, alkaline phosphatase (ALP, total bilirubin, LPO with a reduction of total protein, superoxide dismutase (SOD, catalase, and reduced glutathione (GSH. Treatment of rats with plant extract (500 mg/kg significantly (P<0.01 altered serum marker enzymes and antioxidant levels to near normal against CCl4 - treated rats. The activity of the extract at dose of 500 mg/kg was comparable to the standard drug, Silymarin (50 mg/kg, p.o.. Histopathological examination of the liver tissues supported the hepatoprotective activity of plant.

  8. Pyrazole prevention of CC14-induced ultrastructural changes in rat liver.

    Science.gov (United States)

    Bernacchi, A. S.; de Castro, C. R.; de Toranzo, E. G.; Marzi, A.; de Ferreyra, E. C.; de Fenos, O. M.; Castro, J. A.

    1980-01-01

    Carbon tetrachloride (CC14) administration to rats leads to an early dilatation, vesiculation and disorganization of the liver endoplasmic reticulum (ER). This hepatotoxin also causes detachment of ribosomes from ER membranes, dilatation of the Golgi cisternae and occasionally dilatation of the perinuclear membrane. Prior treatment of the rats with pyrazole completely prevents CC14- induced ultrastructural alterations observed in liver at 3 h. This drug is known to decrease the intensity of the irreversible binding of CC14 reactive metabolites to cellular constituents without modifying the intensity of the CC14- induced lipid peroxidation, either in vitro or in vivo, as measured by the diene conjugation procedure or by decreases inthe arachidonic acid content of microsomal phospholipids. Results suggest that interaction of reactive metabolites rather than lipid peroxidation mediates deleterious effects of CCl4 on the liver ER. Images Fig. 1 Fig. 2 Fig. 3 PMID:7448119

  9. Integrated inventory-based carbon accounting for energy-induced emissions in Chongming eco-island of Shanghai, China

    International Nuclear Information System (INIS)

    The majority of the total carbon emissions in China are energy induced. A clear understanding of energy-induced carbon emissions is therefore necessary for local communities to develop a better carbon emissions management system. We develop an integrated inventory method for energy-induced carbon emissions accounting in local Chinese communities. The method combines scope and sectoral analyses on the basis of local statistical features. As an outcome four core findings are presented: (1) From 2000 to 2009, the energy-induced carbon emissions of Chongming rapidly increased from 1.75 to 4.90 million tons, with the annual growth rate of 12.12%. (2) Emissions from manufacturing, construction, and household sectors accounted for 84.44%; manufacturing is the biggest emitting sector. (3) Carbon emissions from imported electricity reached a historic high of 22.51% in 2009, indicating the necessity of taking the imported carbon emissions into consideration. (4) In 2008, the per capita carbon emissions of Chongming were lower than that of the United States and Shanghai, but higher than that of the global average. Three strategic approaches are proposed: to optimize industrial structure and improve efficiency, reinforce carbon management for the household sector, and enhance carbon statistics. - Highlights: ► The use of natural gas in the large-sized industrial and commercial sectors is shown. ► This study estimates the market potential and characterizes the energy consumption. ► It makes a selection of technological alternatives for the use of natural gas. ► The residual oil and diesel consumption decline over time by the natural gas use. ► In 2017, the cogeneration could provide 7.7% of total electricity demand in Peru.

  10. Defect-Induced Photoluminescence from Dark Excitonic States in Individual Single-Walled Carbon Nanotubes

    OpenAIRE

    Harutyunyan, Hayk; Gokus, Tobias; Green, Alexander A.; Hersam, Mark C.; Allegrini, Maria; Hartschuh, Achim

    2009-01-01

    We show that new low-energy photoluminescence (PL) bands can be created in the spectra of semiconducting single-walled carbon nanotubes by intense pulsed excitation. The new bands are attributed to PL from different nominally dark excitons that are “brightened” because of a defect-induced mixing of states with different parity and/or spin. Time-resolved PL studies on single nanotubes reveal a significant reduction of the bright exciton lifetime upon brightening of the dark excitons. The lowes...

  11. Sunlight-Induced Photochemical Degradation of Methylene Blue by Water-Soluble Carbon Nanorods

    Directory of Open Access Journals (Sweden)

    Anshu Bhati

    2016-01-01

    Full Text Available Water-soluble graphitic hollow carbon nanorods (wsCNRs are exploited for their light-driven photochemical activities under outdoor sunlight. wsCNRs were synthesized by a simple pyrolysis method from castor seed oil, without using any metal catalyst or template. wsCNRs exhibited the light-induced photochemical degradation of methylene blue used as a model pollutant by the generation of singlet oxygen species. Herein, we described a possible degradation mechanism of methylene blue under the irradiation of visible photons via the singlet oxygen-superoxide anion pathway.

  12. Control of tribological properties of diamond-like carbon films with femtosecond-laser-induced nanostructuring

    Science.gov (United States)

    Yasumaru, Naoki; Miyazaki, Kenzo; Kiuchi, Junsuke

    2008-02-01

    This paper reports tribological properties of diamond-like carbon (DLC) films nanostructured by femtosecond (fs) laser ablation. The nanostructure was formed in an area of more than 15 mm × 15 mm on the DLC surface, using a precise target-scan system developed for the fs-laser processing. The frictional properties of the DLC film are greatly improved by coating a MoS 2 layer on the nanostructured surface, while the friction coefficient can be increased by surface texturing of the nanostructured zone in a net-like patterning. The results demonstrate that the tribological properties of a DLC surface can be controlled using fs-laser-induced nanostructuring.

  13. Carbon dioxide induced panic attacks and short term clonazepam treatment: preliminary study

    OpenAIRE

    NARDI ANTONIO EGIDIO; VALENÇA ALEXANDRE M.; ZIN WALTER; NASCIMENTO ISABELLA

    1999-01-01

    AIMS: 1. To verify the sensibility of panic patients to a mixture of 35% CO2 and 65% O2. 2. To determine if a ten days treatment with clonazepam attenuates the panic attacks induced by the inhalation of 35% carbon dioxide in panic disorder. METHOD: We randomly selected six panic disorder subjects, using the Structured Clinical Interview for DSM-IV. All subjects went double-blindly through an inhalation of 35% CO2 and compressed gas (atmospheric air) on two occasions. First, at baseline, when ...

  14. Crystal structure of polymeric carbon nitride and the determination of its process-temperature-induced modifications

    Science.gov (United States)

    Tyborski, T.; Merschjann, C.; Orthmann, S.; Yang, F.; Lux-Steiner, M.-Ch; Schedel-Niedrig, Th

    2013-10-01

    Based on the arrangement of two-dimensional ‘melon’, we construct a unit cell for polymeric carbon nitride (PCN) synthesized via thermal polycondensation, whose theoretical diffraction powder pattern includes all major features measured in x-ray diffraction. With the help of this unit cell, we describe the process-temperature-induced crystallographic changes in PCN that occur within a temperature interval between 510 and 610 °C. We also discuss further potential modifications of the unit cell for PCN. It is found that both triazine- and heptazine-based g-C3N4 can only account for minor phases within the investigated synthesis products.

  15. Spin-Filter Effect Induced by Magnetic Edge States of Zigzag Carbon Nanotube

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhan-Feng; LI Jian; SHEN Shun-Qing; LIU Wu-Ming

    2008-01-01

    @@ Spin-filter effect is predicted in a weak coupled junction composed of a nonmagnetic metal electrode and a zigzag carbon nanotube. This effect is induced by the magnetic edge states of the nanotube, and can produce spinpolarized current in the absence of an external magnetic field. We find that the spin polarization of the current changes its sign at the half-filling point of the nanotube, thus electric field control of spin transport can be realized. Furthermore, we find the coupling strength of the junction may cause a magnetic transition on the edge of the nanotube.

  16. Time-resolved laser-induced incandescence from multiwalled carbon nanotubes in air

    Energy Technology Data Exchange (ETDEWEB)

    Mitrani, J. M. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08540, USA; Shneider, M. N. [Department of Mechanical Engineering, Princeton University, Princeton, New Jersey 08544, USA

    2015-01-26

    We observed temporal laser-induced incandescence (LII) signals from multiwalled carbon nanotubes(MWCNTs) suspended in ambient air. Unlike previous LII experiments with soot particles, which showed that primary particles with larger diameters cool at slower timescales relative to smaller particles, we observed that thicker MWCNTs with larger outer diameters (ODs) cool at faster timescales relative to thinner MWCNTs with smaller ODs. We suggested a simple explanation of this effect, based on the solution of one-dimensional nonstationary heat conduction equation for the initial non-uniform heating of MWCNTs with ODs greater than the skin depth.

  17. Fabrication of Carbon Nanotube Thin Films by Evaporation-Induced Self-Assembly

    OpenAIRE

    Li, Han

    2015-01-01

    In summary, we have prepared single-wall carbon nanotube (SWNT) thin films by the method of evaporation-induced self-assembly (EISA). Using the scalable two-plate or lens setups, sorts of different film types or patterns of SWNTs has been successfully fabricated directly from the evaporation of solvents and could be precisely controlled by the concentrations of SWNT in ambient conditions. The special geometry of meniscus as the capillary bridge has not only given rise to a much higher efficie...

  18. Flow Field Induced Steady Alignment of Oxidized Multi-walled Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    Ai Zhong XU; Ming Shu YANG; Qiang WU; Xiao Ming HU; Lei JIANG

    2005-01-01

    The steady ordered micro-ribbons of oxidized multi-walled carbon nanotubes (MWNTs)were obtained through micro-aperture PTFE membrane by vacuum filtration. After treatment by mixture of concentrated nitric acid and sulfuric acid, the surface functional groups modified MWNTs can be easily dispersed to form a homogeneous suspension. It is found that the steady micro-ribbons existed in the films obtained by vacuum filtration of the suspension. The filtration formed steady flow field and induced steady alignment of oxidized MWNTs. The chemical treatment of MWNTs forming strong interaction between MWNTs is necessity to keep steady of the micro-ribbons microstructure.

  19. Carbon dioxide activation and reaction induced by electron transfer at an oxide-metal interface.

    Science.gov (United States)

    Calaza, Florencia; Stiehler, Christian; Fujimori, Yuichi; Sterrer, Martin; Beeg, Sebastian; Ruiz-Oses, Miguel; Nilius, Niklas; Heyde, Markus; Parviainen, Teemu; Honkala, Karoliina; Häkkinen, Hannu; Freund, Hans-Joachim

    2015-10-12

    A model system has been created to shuttle electrons through a metal-insulator-metal (MIM) structure to induce the formation of a CO2 anion radical from adsorbed gas-phase carbon dioxide that subsequently reacts to form an oxalate species. The process is completely reversible, and thus allows the elementary steps involved to be studied at the atomic level. The oxalate species at the MIM interface have been identified locally by scanning tunneling microscopy, chemically by IR spectroscopy, and their formation verified by density functional calculations.

  20. Liquid flow-induced energy harvesting in carbon nanotubes: a molecular dynamics study.

    Science.gov (United States)

    Xu, Baoxing; Chen, Xi

    2013-01-28

    Energy harvesting by the flow of a hydrochloric acid-water solution through a carbon nanotube (CNT) is explored using atomistic simulations. Through ion configurations near the CNT wall, the ion drifting velocity is obtained, and the induced voltage along the axial direction is obtained as a function of key material and system parameters, including the applied flow rate, ambient temperature, solution concentration and nanotube diameter. The molecular mechanism of ion hopping and motion is elucidated and related to the variation of material and system parameters. PMID:23223386

  1. Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

    International Nuclear Information System (INIS)

    Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for ''direct-write'' processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple ''beams'' of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications' prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials. (orig.)

  2. Focused-electron-beam-induced processing (FEBIP) for emerging applications in carbon nanoelectronics

    Science.gov (United States)

    Fedorov, Andrei G.; Kim, Songkil; Henry, Mathias; Kulkarni, Dhaval; Tsukruk, Vladimir V.

    2014-12-01

    Focused-electron-beam-induced processing (FEBIP), a resist-free additive nanomanufacturing technique, is an actively researched method for "direct-write" processing of a wide range of structural and functional nanomaterials, with high degree of spatial and time-domain control. This article attempts to critically assess the FEBIP capabilities and unique value proposition in the context of processing of electronics materials, with a particular emphasis on emerging carbon (i.e., based on graphene and carbon nanotubes) devices and interconnect structures. One of the major hurdles in advancing the carbon-based electronic materials and device fabrication is a disjoint nature of various processing steps involved in making a functional device from the precursor graphene/CNT materials. Not only this multi-step sequence severely limits the throughput and increases the cost, but also dramatically reduces the processing reproducibility and negatively impacts the quality because of possible between-the-step contamination, especially for impurity-susceptible materials such as graphene. The FEBIP provides a unique opportunity to address many challenges of carbon nanoelectronics, especially when it is employed as part of an integrated processing environment based on multiple "beams" of energetic particles, including electrons, photons, and molecules. This avenue is promising from the applications' prospective, as such a multi-functional (electron/photon/molecule beam) enables one to define shapes (patterning), form structures (deposition/etching), and modify (cleaning/doping/annealing) properties with locally resolved control on nanoscale using the same tool without ever changing the processing environment. It thus will have a direct positive impact on enhancing functionality, improving quality and reducing fabrication costs for electronic devices, based on both conventional CMOS and emerging carbon (CNT/graphene) materials.

  3. Deposition of calcium carbonate films by a polymer-induced liquid-precursor (PILP) process

    Science.gov (United States)

    Gower, Laurie B.; Odom, Damian J.

    2000-03-01

    A polypeptide additive has been used to transform the solution crystallization of calcium carbonate to a solidification process of a liquid-phase mineral precursor. In situ observations reveal that polyaspartate induces liquid-liquid phase separation of droplets of a mineral precursor. The droplets deposit on the substrate and coalesce to form a coating, which then solidifies into calcitic tablets and films. Transition bars form during the amorphous to crystalline transition, leading to sectorization of calcite tablets, and the defect textures and crystal morphologies are atypical of solution grown crystals. The formation of nonequilibrium crystal morphologies using an acidic polypeptide may have implications in the field of biomineralization, and the environmentally friendly aspects of this polymer-induced liquid-precursor (PILP) process may offer new techniques for aqueous-based processing of ceramic films, coatings, and particulates.

  4. Charge trapping in aligned single-walled carbon nanotube arrays induced by ionizing radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Esqueda, Ivan S., E-mail: isanchez@isi.edu [Information Sciences Institute, University of Southern California, Arlington, Virginia 22203 (United States); Cress, Cory D. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States); Che, Yuchi; Cao, Yu; Zhou, Chongwu [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States)

    2014-02-07

    The effects of near-interfacial trapping induced by ionizing radiation exposure of aligned single-walled carbon nanotube (SWCNT) arrays are investigated via measurements of gate hysteresis in the transfer characteristics of aligned SWCNT field-effect transistors. Gate hysteresis is attributed to charge injection (i.e., trapping) from the SWCNTs into radiation-induced traps in regions near the SWCNT/dielectric interface. Self-consistent calculations of surface-potential, carrier density, and trapped charge are used to describe hysteresis as a function of ionizing radiation exposure. Hysteresis width (h) and its dependence on gate sweep range are investigated analytically. The effects of non-uniform trap energy distributions on the relationship between hysteresis, gate sweep range, and total ionizing dose are demonstrated with simulations and verified experimentally.

  5. Laser-induced breakdown spectroscopy (LIBS) to measure quantitatively soil carbon with emphasis on soil organic carbon. A review.

    Science.gov (United States)

    Senesi, Giorgio S; Senesi, Nicola

    2016-09-28

    Soil organic carbon (OC) measurement is a crucial factor for quantifying soil C pools and inventories and monitoring the inherent temporal and spatial heterogeneity and changes of soil OC content. These are relevant issues in addressing sustainable management of terrestrial OC aiming to enhance C sequestration in soil, thus mitigating the impact of increasing CO2 concentration in the atmosphere and related effects on global climate change. Nowadays, dry combustion by an elemental analyzer or wet combustion by dichromate oxidation of the soil sample are the most recommended and commonly used methods for quantitative soil OC determination. However, the unanimously recognized uncertainties and limitations of these classical laboursome methods have prompted research efforts focusing on the development and application of more advanced and appealing techniques and methods for the measurement of soil OC in the laboratory and possibly in situ in the field. Among these laser-induced breakdown spectroscopy (LIBS) has raised the highest interest for its unique advantages. After an introduction and a highlight of the LIBS basic principles, instrumentation, methodologies and supporting chemometric methods, the main body of this review provides an historical and critical overview of the developments and results obtained up-to-now by the application of LIBS to the quantitative measurement of soil C and especially OC content. A brief critical summary of LIBS advantages and limitations/drawbacks including some final remarks and future perspectives concludes this review. PMID:27619082

  6. Carbon Monoxide Inhibits Receptor Activator of NF-κB (RANKL-Induced Osteoclastogenesis

    Directory of Open Access Journals (Sweden)

    Feng-Jen Tseng

    2015-07-01

    Full Text Available Background: Low concentrations of carbon monoxide (CO have anti-inflammatory effects and can reduce bone erosion in a murine collagen-induced arthritis model. The objective of this study was to assess the effects of CO on receptor activator of NF-γB ligand (RANKL, one of the key stimulators of osteoclastogenesis. Methods: The in vivo effects of CO on RANKL expression were assessed in a collagen antibody-induced arthritis model in mice. Cell proliferation and apoptosis were assessed in the RAW246.7 cell line stimulated with RANKL and exposed to either air or CO. The number of tartrate resistant acid phosphatase (TRAP-positive RAW246.7 cells was also examined after treatment with RANKL and the peroxisome proliferator-activated receptor gamma (PPARγ agonist, Troglitazone. Results: CO reduced RANKL expression in the synovium of arthritic mice. Although CO slightly increased RAW246.7 cell proliferation, no differences in activated caspase 3 levels were detected. In addition, Troglitazone ameliorated the inhibitory effects of CO on RANKL-induced TRAP expression by RAW246.7 cells. Conclusions: CO suppresses osteoclast differentiation by inhibiting the RANKL-induced activation of PPAR-γ. Given the role of the PPAR-γ/cFos (AP-1 pathway in regulating the transcription factor, NFATc1, the master regulator of osteoclastogenesis, further studies are warranted to explore CO in treating inflammatory bone disorders.

  7. Inhibition of hypoxia-inducible carbonic anhydrase-IX enhances hexokinase Ⅱ inhibitor-induced hepatocellular carcinoma cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Su-jong YU; Hyo-suk LEE; Jung-hwan YOON; Jeong-hoon LEE; Sun-jung MYUNG; Eun-sun JANG; Min-sun KWAK; Eun-ju CHO; Ja-june JANG; Yoon-jun KIM

    2011-01-01

    Aim: The hypoxic condition within large or infiltrative hypovascular tumors produces intracellular acidification, which could activate many signaling pathways and augment cancer cell growth and invasion. Carbonic anhydrase-Ⅸ (CA-Ⅸ) is an enzyme lowering pH. This study is to examine whether hypoxia induces CA-Ⅸ in hepatocellular carcinoma (HCC) cells, and to evaluate its clinical implication in HCC patients.Methods: Human HCC cell lines (Huh-7 and HepG2 cells) were used, and cell growth was assessed using MTS assay. CA-IX expression and apoptotic/kinase signaling were evaluated using immunoblotting. The cells were transfected with CA-Ⅸ-specific siRNA, or treated with its inhibitor 4-(2-aminoethyl) benzenesulfonamide (CAI#1), and/or the hexokinase Ⅱ inhibitor, 3-bromopyruvate (3-BP). A clinic pathological analysis of 69 patients who underwent an HCC resection was performed using a tissue array.Results: Incubation of HCC cells under hypoxia (1% 02, 5% C02, 94% N2) for 36 h significantly increased CA-IX expression level. CAI#1(400 μmol/L) or CA-IX siRNA (100 μmol/L) did not influence HCC cell growth and induce apoptosis. However, CAI#1 or CA-IX siRNA at these concentrations enhanced the apoptosis induced by 3-BP (100 μmol/L). This enhancement was attributed to increased ER stress and JNK activation, as compared with 3-BP alone. Furthermore, a clinic pathological analysis of 69 HCC patients revealed that tumor CA-Ⅸ intensity was inversely related to E-cadherin intensity.Conclusion: Inhibition of hypoxia-induced CA-Ⅸ enhances hexokinase Ⅱ inhibitor-induced HCC apoptosis. Furthermore, CA-IX expres sion profiles may have prognostic implications in HCC patients. Thus, the inhibition of CA-Ⅸ, in combination with a hexokinase Ⅱ inhibitor, may be therapeutically useful in patients with HCCs that are aggressively growing in a hypoxic environment.

  8. Carbon dioxide induced panic attacks and short term clonazepam treatment: preliminary study

    Directory of Open Access Journals (Sweden)

    NARDI ANTONIO EGIDIO

    1999-01-01

    Full Text Available AIMS: 1. To verify the sensibility of panic patients to a mixture of 35% CO2 and 65% O2. 2. To determine if a ten days treatment with clonazepam attenuates the panic attacks induced by the inhalation of 35% carbon dioxide in panic disorder. METHOD: We randomly selected six panic disorder subjects, using the Structured Clinical Interview for DSM-IV. All subjects went double-blindly through an inhalation of 35% CO2 and compressed gas (atmospheric air on two occasions. First, at baseline, when they were drug free. Second, after a 10 days clonazepam treatment. RESULTS: Neither at baseline nor after treatment any patient had a panic attack during compressed gas inhalation. At the first test five patients (83.3% had a severe panic attack with high levels of subjective anxiety during carbon dioxide inhalation. After 9.6 (± 3.4 days of clonazepam treatment, only two (33.3% patients experienced a mild panic attack. CONCLUSION: This pilot study suggests the efficacy of the short term clonazepam therapy in attenuating panic attacks and supports the usefulness of the 35% carbon dioxide challenge test as an analogue method for study the efficacy of anti-panic drugs. Further placebo-controlled studies to pharmacological treatment are warranted.

  9. Application of laser-induced breakdown spectroscopy in carbon sequestration research and development

    Indian Academy of Sciences (India)

    Jinesh Jain; Dustin Mcintyre; Krishna Ayyalasomayajula; Vivek Dikshit; Christian Goueguel; F Yu-Yueh; Jagdish Singh

    2014-08-01

    The success of carbon capture and storage (CCS) programme relies on the long-term isolation of CO2 from the atmosphere. Therefore, technologies concomitant to physical storage of CO2 such as reliable measurement, monitoring, and verification (MMV) techniques are needed to ensure that the integrity of the storage site is maintained. We propose the use of laser-induced breakdown spectroscopy (LIBS) analytical technique to detect carbon dioxide leaks to aid in the successful application of CCS. LIBS has a real-time monitoring capability and can be reliably used for the elemental and isotopic analysis of solid, liquid, and gas samples. The flexibility of probe design and use of fibre optics make it a suitable technique for real-time measurements in harsh conditions and at hard-to-reach places. Proposed monitoring with LIBS includes terrestrial soil samples, water samples from monitoring wells or from different formations, air samples from monitoring wells or suspected leakage areas. This work details the laboratory scale experiments to measure carbon contents in soil, aqueous, and air samples. The potential of the technology for measurements in high-pressure, high-temperature conditions has been discussed.

  10. Flow induced vibration and stability analysis of multi wall carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Kyung Jae [Agency for Defense Development, Daejeon (Korea, Republic of); Choi, Jong Woon [Korean Intellectual Property Office, Daejeon (Korea, Republic of); Kim, Sung Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Song, Oh Seop [Chungnam National Univ., Daejeon (Korea, Republic of)

    2012-12-15

    The free vibration and flow induced flutter instability of cantilever multi wall carbon nanotubes conveying fluid are investigated and the nanotubes are modeled as thin-walled beams. The non-classical effects of the transverse shear, rotary inertia, warping inhibition, and van der Waals forces between two walls are incorporated into the structural model. The governing equations and associated boundary conditions are derived using Hamilton's principle. A numerical analysis is carried out by using the extended Galerkin method, which enables us to obtain more accurate solutions compared to the conventional Galerkin method. Cantilevered carbon nanotubes are damped with decaying amplitude for a flow velocity below a certain critical value. However, beyond this critical flow velocity, flutter instability may occur. The variations in the critical flow velocity with respect to both the radius ratio and length of the carbon nanotubes are investigated and pertinent conclusions are outlined. The differences in the vibration and instability characteristics between the Timoshenko beam theory and Euler beam theory are revealed. A comparative analysis of the natural frequencies and flutter characteristics of MWCNTs and SWCNTs is also performed.

  11. Facile synthesis of gradient mesoporous carbon monolith based on polymerization-induced phase separation

    Science.gov (United States)

    Xu, Shunjian; Luo, Yufeng; Zhong, Wei; Xiao, Zonghu; Luo, Yongping; Ou, Hui; Zhao, Xing-Zhong

    2014-06-01

    In this paper, a gradient mesoporous carbon (GMC) monolith derived from the mixtures of phenolic resin (PF) and ethylene glycol (EG) was prepared by a facile route based on polymerization-induced phase separation under temperature gradient (TG). A graded biphasic structure of PF-rich and EG-rich phases was first formed in preform under a TG, and then the preform was pyrolyzed to obtain the GMC monolith. The TG is mainly induced by the thermal resistance of the preferential phase separation layer at high temperature region. The pore structure of the monolith changes gradually along the TG direction. When the TG varies from 58°C to 29°C, the pore size, apparent porosity and specific surface area of the monolith range respectively from 18 nm to 83 nm, from 32% to 39% and from 140.5 m2/g to 515.3 m2/g. The gradient porous structure of the monolith is inherited from that of the preform, which depends on phase separation under TG in the resin mixtures. The pyrolysis mainly brings about the contraction of the pore size and wall thickness as well as the transformation of polymerized PF into glassy carbon.

  12. Removal of technetium, carbon tetrachloride, and metals from DOE properties. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, T.E.; Darab, J.G.; Ponder, S.M.

    1998-06-01

    'The objective of the project is to develop and characterize supported reducing agents, and solid waste forms derived from them, which will be effective in the removal of transition metal ions, chlorinated organic molecules, and technetium from aqueous mixed wastes. This work follows the discovery that a nanoscale form of zero-valent iron, dispersed on high surface area supports, reduces metal ions (chromium, mercury, and lead) and rhenium (as a surrogate for technetium) to insoluble forms much faster than does unsupported iron. The scientific goals of the project are to better understand the mechanism of the reduction process, to develop supports that are compatible with a variety of mixed waste compositions, and to develop surface modifiers for the supported iron aggregates that will optimize their selectivity for the contaminants of interest. The support composition is of particular interest in the case of technetium (Tc) separation and stabilization in the Hanford tank wastes. While it is expected that pertechnetate will be reduced insoluble TcO{sub 2} , the support material must be compatible with the vitrification process used in the final waste disposition. The surface modifications are also a focal point for Hanford applications because of the complex and variable makeup of the tank wastes. This report summarizes progress in the first 8 months of a 3-year collaborative project involving Penn State and Pacific Northwest National Laboratory (PNNL).'

  13. The reduction of uranium hexafluoride by carbon tetrachloride in the gaseous phase

    International Nuclear Information System (INIS)

    The reduction of UF6 to UF4 by CCl4 in a 0.08 m diameter vertical glass reactor has been studied. In the tests, UF6 and CCl4, preheated to about 350 deg C, were fed into the reactor and the tower walls were held at about 500 deg C, the reaction was taking place almost completely in the gaseous phase. A high temperature flames can be visually observed by increasing in the reactant feed rates, and the brightness of the flame changes with the reactant feed rates. The conversion of UF6 is essentially complete if a CCl4 excess is maintained. The method is considered to be an effective process to meet continuous conversion of slightly enriched UF6

  14. Covalent modification of hepatic microsomal lipids of rats by carbon tetrachloride

    International Nuclear Information System (INIS)

    The present study was undertaken to isolate and identify various lipids bound to 14C label during hepatic microsomal metabolism of 14CCl4 in vitro under anaerobic conditions and in vivo in rats. The two major radioactive fractions identified by thin-layer chromatography each for neutral lipids and phospholipids from in vitro and in vivo experiments corresponded to fatty acids and triglycerides and to phosphatidylcholine (PC) and phosphatidylethanolamine (PE), respectively. Approximately 89% of the radioactivity associated with phospholipids was found in PC and PE fractions. Hydrolysis of PC and PE with phospholipase A2 released about 50% of the total radioactivity as lipid moieties corresponding to fatty acids. The radioactive neutral lipids and the lipid moieties hydrolyzed from PC and PE were methylated with boron trifluoride in methanol. These methylated lipids were separated by reversed-phase high-performance liquid chromatography (HPLC), and the elution profiles of 14C label found for the lipids obtained from in vitro experiments were similar to those from in vivo. The major radioactive fractions eluted immediately after methyl oleate were identified as trichloromethyloctadecenoic and trichloromethyleicosatrienoic acid methyl esters by chemical ionization mass spectrometry. The mass spectral analysis of these fractions also indicated the formation of dichlorocarbene adduct of oleic acid. However, similar mass spectrometric detection of trichloromethylated lipids was not evident in neutral lipids and phospholipids isolated from in vivo studies. The 14C-labeled lipids eluted as a nonpolar fraction exhibited a high molecular weight containing more than three chlorines. Dimerization and cross-linking of trichloromethylated lipids based on HPLC and mass spectral analysis are also discussed in this paper

  15. The n-Octyldodecylsulfoxide(ODSO)-carbon tetrachloride extracting uranium(VI)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The liquid-liquid extraction behavior of uranium(VI) from nitric acid aqueous solution with n-octyldodecylsulfoxide(ODSO) has been studied over a wide range of conditions. The extracted species appear to be UO2(NO3)2.2ODSO. It was found that the extraction was increased with increasing sodium nitrate concentration. Extracting also increases with increasing extractant concentration. The influence of temperature and nitric acid concentration on extraction equilibrium was also investi gated and the enthalpy of the extraction reaction was obtained.

  16. Effect of carbon tetrachloride on glycogen metabolism in fasted and refed mice

    International Nuclear Information System (INIS)

    Hepatic glycogen was depleted rapidly in fasted mice treated with CCl4. Glycogen breakdown was slow when CCl4 was administered after 1 hr of refeeding. There was an initial increase and then a reduction in liver glycogen of mice refed for 2 hr prior to CCl4 injection. The incorporation of glucose-U-14C into glycogen was higher in mice which were refed before CCl4 administration than in fasted mice treated with the hepatotoxin. The specific activity of lactate was higher in CCl4 treated mice. The data suggested differences in glycogen metabolism of fasted and refed mice in response to CCl4 treatment. (author)

  17. Localized surface grafting reactions on carbon nanofibers induced by gamma and e-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Evora, M.C., E-mail: cecilia@ieav.cta.br [Institute for Advanced Studies-IEAV/DCTA, Av. Cel Jose Alberto Albano do Amarante, 1-Putim, 12228-001 São Jose dos Campos, SP (Brazil); Araujo, J.R., E-mail: jraraujo@inmetro.gov.br [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Ferreira, E.H.M. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil); Strohmeier, B.R. [Thermo Fisher Scientific, 5225 Verona Road, Madison, WI 53711 (United States); Silva, L.G.A., E-mail: lgasilva@ipen.br [Institute for Nuclear and Energy Research- IPEN, Av. Prof lineu Prestes, 2242- Cidade Universitaria, 05508-000 SP (Brazil); Achete, C.A. [Instituto Nacional de Metrologia, Qualidade e Tecnologia, Av. Nossa Sra. das Graças, 50, 25250-020 Duque de Caxias, RJ (Brazil)

    2015-04-30

    Graphical abstract: - Highlights: • Methodology for the functionalization of carbon nanofibers was investigated. • Two radiation sources were used to promote grafting reactions: gamma and electron beam. • We report the optimum inhibitor concentration to achieve the functionalization. • Surface of carbon nanofibers showed an increase of oxygen content after irradiation. • The radiation-induced graphitization did not damage the overall sp{sup 2} structure. - Abstract: Electron beam and gamma-ray irradiation have potential application to modify the carbon fiber nanostructures in order to produce useful defects in the graphitic structure and create reactive sites. In this study, the methodology to functionalize carbon nanofiber (CNF), via a radiation process and using acrylic acid as a source of oxygen functional groups, was investigated. The samples were submitted to a direct grafting radiation process with electron beam and gamma-ray source. Several parameters were changed such as: acrylic acid concentration, radiation dose and percentage of inhibitor necessary to achieve functionalization, with higher percentage of oxygen functional groups on CNF surface, and better dispersion. The better results achieved were when mixing CNF in a solution of acrylic acid with 6% of inhibitor (FeSO{sub 4}·7H{sub 2}O) and irradiated at 100 kGy. The samples were characterized by X-ray photoelectron spectroscopy and the surface composition (atomic%) showed a significant increase of oxygen content for the samples after irradiation. Also, the dispersion of the functionalized CNF in water was stable during months which may be a good indication that the functionalization process of CNF via ionizing radiation was successful.

  18. Impact of brine-induced stratification on the glacial carbon cycle

    Directory of Open Access Journals (Sweden)

    N. Bouttes

    2010-04-01

    Full Text Available During the cold period of the Last Glacial Maximum (LGM, about 21 000 years ago atmospheric CO2 was around 190 ppm (Monnin et al., 2001, much lower than the pre-industrial concentration of 280 ppm. The causes of this substantial drop remain partially unresolved, despite intense research. Understanding the origin of reduced atmospheric CO2 during glacial times is crucial to comprehend the evolution of the different carbon reservoirs within the Earth system (atmosphere, terrestrial biosphere and ocean. In this context, the ocean is believed to play a major role as it can store large amounts of carbon (Sigman and Boyle, 2000, especially in the abyss, which is a carbon reservoir that is thought to have expanded during glacial times. To create this larger reservoir, one possible mechanism is to produce very dense glacial waters, thereby stratifying the deep ocean and reducing the carbon exchange between the deep and surface ocean (Paillard and Parrenin, 2004. The existence of such very dense waters has been inferred in the LGM deep Atlantic from sediment pore water salinity (Adkins et al., 2002. Based on these observations, we study the impact of a brine mechanism on the glacial carbon cycle. This mechanism relies on the formation and rapid sinking of brines, very salty water released during sea ice formation, which brings salty dense water down to the bottom of the ocean. It provides two major features: a direct link from the surface to the deep ocean along with an efficient way of setting a strong stratification. We show with the CLIMBER-2 coupled carbon-climate model (Petoukhov et al., 2000 that such a brine mechanism can account for a significant decrease in atmospheric CO2 and contribute to the glacial-interglacial change. This mechanism can be amplified by low vertical diffusion resulting from the brine-induced stratification. The results obtained substantially improve the modeled glacial distribution of oceanic

  19. Impact of brine-induced stratification on the glacial carbon cycle

    Directory of Open Access Journals (Sweden)

    N. Bouttes

    2010-09-01

    Full Text Available During the cold period of the Last Glacial Maximum (LGM, about 21 000 years ago atmospheric CO2 was around 190 ppm, much lower than the pre-industrial concentration of 280 ppm. The causes of this substantial drop remain partially unresolved, despite intense research. Understanding the origin of reduced atmospheric CO2 during glacial times is crucial to comprehend the evolution of the different carbon reservoirs within the Earth system (atmosphere, terrestrial biosphere and ocean. In this context, the ocean is believed to play a major role as it can store large amounts of carbon, especially in the abyss, which is a carbon reservoir that is thought to have expanded during glacial times. To create this larger reservoir, one possible mechanism is to produce very dense glacial waters, thereby stratifying the deep ocean and reducing the carbon exchange between the deep and upper ocean. The existence of such very dense waters has been inferred in the LGM deep Atlantic from sediment pore water salinity and δ18O inferred temperature. Based on these observations, we study the impact of a brine mechanism on the glacial carbon cycle. This mechanism relies on the formation and rapid sinking of brines, very salty water released during sea ice formation, which brings salty dense water down to the bottom of the ocean. It provides two major features: a direct link from the surface to the deep ocean along with an efficient way of setting a strong stratification. We show with the CLIMBER-2 carbon-climate model that such a brine mechanism can account for a significant decrease in atmospheric CO2 and contribute to the glacial-interglacial change. This mechanism can be amplified by low vertical diffusion resulting from the brine-induced stratification. The modeled glacial distribution of oceanic δ13C as well as the deep ocean salinity are substantially improved and better agree with reconstructions from

  20. Structure and bonding in crystalline cesium uranyl tetrachloride under pressure.

    Science.gov (United States)

    Osman, Hussien H; Pertierra, Pilar; Salvadó, Miguel A; Izquierdo-Ruiz, F; Recio, J M

    2016-07-21

    A thorough investigation of pressure effects on the structural properties of crystalline cesium uranyl chloride was performed by means of first-principles calculations within the density functional theory framework. Total energies, equilibrium geometries and vibrational frequencies were computed at selected pressures up to 50 GPa. Zero pressure results present good agreement with available experimental and theoretical data. Our calculated equation of state parameters reveal that Cs2UO2Cl4 is a high compressible material, similar to other ionic compounds with cesium cations, and displays a structural anisotropic behavior guided by the uranyl moiety. An unexpected variation of the U-O bond length, dUO, is detected as pressure is applied. It leads to a dUO-stretching frequency relationship that cannot be described by the traditional Badger's rule. Interestingly enough, it can be explained in terms of a change in the main factor controlling dUO. At low pressure, the charge transferred to the uranyl cation induces an increase of the bond length and a red shift of the stretching frequencies, whereas it is the mechanical effect of the applied pressure above 10 GPa that is the dominant factor that leads to a shortening of dUO and a blue shift of the stretching frequencies. PMID:27340008

  1. Structure and bonding in crystalline cesium uranyl tetrachloride under pressure.

    Science.gov (United States)

    Osman, Hussien H; Pertierra, Pilar; Salvadó, Miguel A; Izquierdo-Ruiz, F; Recio, J M

    2016-07-21

    A thorough investigation of pressure effects on the structural properties of crystalline cesium uranyl chloride was performed by means of first-principles calculations within the density functional theory framework. Total energies, equilibrium geometries and vibrational frequencies were computed at selected pressures up to 50 GPa. Zero pressure results present good agreement with available experimental and theoretical data. Our calculated equation of state parameters reveal that Cs2UO2Cl4 is a high compressible material, similar to other ionic compounds with cesium cations, and displays a structural anisotropic behavior guided by the uranyl moiety. An unexpected variation of the U-O bond length, dUO, is detected as pressure is applied. It leads to a dUO-stretching frequency relationship that cannot be described by the traditional Badger's rule. Interestingly enough, it can be explained in terms of a change in the main factor controlling dUO. At low pressure, the charge transferred to the uranyl cation induces an increase of the bond length and a red shift of the stretching frequencies, whereas it is the mechanical effect of the applied pressure above 10 GPa that is the dominant factor that leads to a shortening of dUO and a blue shift of the stretching frequencies.

  2. Effect of the Chronic Use of Lithium Carbonate on Induced Tooth Movement in Wistar Rats

    Science.gov (United States)

    da Silva Kagy, Viviane; Trevisan Bittencourt Muniz, Luciana; Michels, Arieli Carini; Luiz, Suelen Teixeira; Reis Azevedo Alanis, Luciana; Brancher, João Armando; Grégio, Ana Maria Trindade; Ignácio, Sérgio Aparecido; Camargo, Elisa Souza; Machado, Maria Ângela Naval

    2016-01-01

    Patients who seek dental treatment may have bipolar disorder, and lithium carbonate (LC) is the drug of choice used in the treatment of this disorder. Taking into consideration the controversial results found in the literature, and the possible influence of LC on induced tooth movement, the objective was to evaluate tooth movement induced in rats after administration of lithium carbonate. One hundred and ninety-two rats were divided into 3 groups. In the L group, the animals received daily 60mg/kg of LC, they were not subjected to orthodontic movement, and they were euthanized after 33, 37, 44 or 51 days. In the LM group, the LC was administered for 30 days and during the subsequent 3, 7, 14 and 21 days, corresponding to the period of induced tooth movement, and they received a spring that produced a 30cN force. In the SM group, saline solution was applied. Measurements were made of tooth displacement, the numbers of osteoclasts and serum lithium phosphate (PO4), alkaline phosphatase (ALP) and creatinine levels. The tooth displacement was lower in the LM group compared to the SM group at 44 days. A tendency toward reduction in the number of osteoclasts was observed in the LM group compared to the SM group at 44 days. The average lithium were higher in the L and LM groups compared to the SM group. The opposite was observed for the PO4 group. A higher value for the ALP was found in the L group. The average creatinine level was lower in the LM group. LC inhibited tooth movement for 14 days, possibly due to the reduction in the number of osteoclasts. PMID:27487121

  3. Effect of pumpkin seed (Cucurbita pepo) protein isolate on the activity levels of certain plasma enzymes in CCl4-induced liver injury in low-protein fed rats.

    Science.gov (United States)

    Nkosi, C Z; Opoku, A R; Terblanche, S E

    2005-04-01

    The effects of pumpkin seed (Cucurbita pepo) protein isolate on the activity levels of lactate dehydrogenase (LD), alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) against carbon tetrachloride (CCl4)-induced acute liver injury in low-protein fed rats were investigated. A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl4 intoxication one of the two subgroups was administered with pumpkin seed protein isolate. All three subgroups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all four enzymes were significantly higher than their counterparts on a normal balanced diet. CCl4 intoxication resulted in significant increases in the activity levels of all four enzymes investigated. The administration of pumpkin seed protein isolate after CCl4 intoxication resulted in significantly reduced activity levels of all four enzymes. It is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein malnutrition. PMID:16041732

  4. 有机质对土壤气相抽提去除四氯化碳效率的影响%Tetrachloride from Soils by Soil Vapor Extraction

    Institute of Scientific and Technical Information of China (English)

    卢中华; 裴宗平; 鹿守敢; 王岩; 胡佳佳; 闫姗

    2011-01-01

    A main Karst groundwater supply source was polluted by carbon tetrachloride. Column-venting experiment was done to simulate soil vapor extraction in order to inquiry the removal of carbon tetrachloride from soil. Experiment was done at 20 ℃ with venting velocity of 40 mL/min, the two kinds of experimental soils moisture content were both 10%, but organic matter content were 3.02% and 0.13% respectively. Results showed that carbon tetrachloride can be effectively removed by ventilation. Removal of carbon tetrachloride in soil follows the first order reaction kinetics. There is a good linear relationship between lnC and temperature, with correlation coefficients above 0.95. When soil organic matter content is 3.02%, reaction rate constants of the removal of carbon tetrachloride are 0.013 2 h-1~0.015 5 h-1 in Column Ⅰ. When soil organic matter content is 0.13%, the reaction rate constants are 0.017 1 h-1~0.020 6 h-1 in Colum Ⅱ, which showed that the removal efficiency of soil vapor extraction is related to soil organic matter content, soil with lower organic matter content has higher removal efficiency.%某重要岩溶地下水源地因附近农药厂排放含四氯化碳污水而受到严重污染,实验采用土柱通风试验模拟土壤气相抽提(SVE),研究环境温度为20℃,通风速率为40mL/min,土壤含水率10%,而土壤有机质含量分别为3.02%和0.13%条件下的两种供试土壤中四氯化碳污染物的去除过程.结果表明,土柱通风能有效去除土壤中的四氯化碳污染物;通风条件下四氯化碳的去除过程符合一级反应动力学,土壤中四氯化碳浓度C(μg/L)的对数值lnC与时间t呈良好的线性关系,相关系数均在0.95以上;土壤有机质含量为3.02%的土柱Ⅰ各取样口四氯化碳去除反应速率常数k值在0.0132~0.0155h-1之间,有机质含量为0.13%的土柱Ⅱ各取样口k值在0.0171~0.0206h-1之间,说明土壤气相抽提去除四氯化碳的效率与土

  5. Denture-induced fibrous hyperplasia. Treatment with carbon dioxide laser and a two year follow-up

    Directory of Open Access Journals (Sweden)

    Naveen Kumar J

    2007-01-01

    Full Text Available Denture-induced fibrous hyperplasia (DIFH is a persistent lesion caused mostly by the prolonged wear of an ill-fitting, over-extended denture. Although the condition frequently coexists with denture stomatitis, it is a distinct entity with a different protocol for management. The article describes successful treatment for a case of DIFH using carbon dioxide laser and a two year follow-up. The inherent advantages of using carbon dioxide laser over conventional surgical techniques are discussed.

  6. Real-world carbon nanoparticle exposures induce brain and gonadal alterations in zebrafish (Danio rerio) as determined by biospectroscopy techniques

    OpenAIRE

    Li, Junyi; Ying, Guang-Guo; Jones, Kevin C.; Martin, Francis L.

    2015-01-01

    Carbon-based nanoparticles (CNPs) have emerged as novel man-made materials with diverse applications, which may present significant risks to organisms. To bridge the gap in our knowledge of nano-toxicology, a number of in vitro or in vivo studies have been carried out. However, toxicity data remains limited. Herein, we employed a biospectroscopy approach to assess CNP-induced effects in zebrafish (Danio rerio). Zebrafish were exposed to Fullerene (C60), long or short multi-walled carbon nanot...

  7. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules

    OpenAIRE

    Elizabeth A. Dawson; Parkes, Gareth M. B.; Bond, Gary; Mao, Runjie

    2009-01-01

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic p...

  8. Group IVA phospholipase A(2) deficiency prevents CCl4-induced hepatic cell death through the enhancement of autophagy.

    Science.gov (United States)

    Ishihara, Keiichi; Kanai, Shiho; Tanaka, Kikuko; Kawashita, Eri; Akiba, Satoshi

    2016-02-26

    Group IVA phospholipase A2 (IVA-PLA2), which generates arachidonate, plays a role in inflammation. IVA-PLA2-deficiency reduced hepatotoxicity and hepatocyte cell death in mice that received a single dose of carbon tetrachloride (CCl4) without any inhibitory effects on CCl4-induced lipid peroxidation. An immunoblot analysis of extracts from wild-type mouse- and IVA-PLA2 KO mouse-derived primary hepatocytes that transiently expressed microtubule-associated protein 1 light chain 3B (LC3) revealed a higher amount of LC3-II, a typical index of autophagosome formation, in IVA-PLA2-deficient cells, suggesting the enhancement of constitutive autophagy. IVA-PLA2 may promote CCl4-induced cell death through the suppression of constitutive autophagy in hepatocytes.

  9. The dynamics of carbon stored in xylem sapwood to drought-induced hydraulic stress in mature trees.

    Science.gov (United States)

    Yoshimura, Kenichi; Saiki, Shin-Taro; Yazaki, Kenichi; Ogasa, Mayumi Y; Shirai, Makoto; Nakano, Takashi; Yoshimura, Jin; Ishida, Atsushi

    2016-04-15

    Climate-induced forest die-off is widespread in multiple biomes, strongly affecting the species composition, function and primary production in forest ecosystems. Hydraulic failure and carbon starvation in xylem sapwood are major hypotheses to explain drought-induced tree mortality. Because it is difficult to obtain enough field observations on drought-induced mortality in adult trees, the current understanding of the physiological mechanisms for tree die-offs is still controversial. However, the simultaneous examination of water and carbon uses throughout dehydration and rehydration processes in adult trees will contribute to clarify the roles of hydraulic failure and carbon starvation in tree wilting. Here we show the processes of the percent loss of hydraulic conductivity (PLC) and the content of nonstructural carbohydrates (NSCs) of distal branches in woody plants with contrasting water use strategy. Starch was converted to soluble sugar during PLC progression under drought, and the hydraulic conductivity recovered following water supply. The conversion of NSCs is strongly associated with PLC variations during dehydration and rehydration processes, indicating that stored carbon contributes to tree survival under drought; further carbon starvation can advance hydraulic failure. We predict that even slow-progressing drought degrades forest ecosystems via carbon starvation, causing more frequent catastrophic forest die-offs than the present projection.

  10. The dynamics of carbon stored in xylem sapwood to drought-induced hydraulic stress in mature trees.

    Science.gov (United States)

    Yoshimura, Kenichi; Saiki, Shin-Taro; Yazaki, Kenichi; Ogasa, Mayumi Y; Shirai, Makoto; Nakano, Takashi; Yoshimura, Jin; Ishida, Atsushi

    2016-01-01

    Climate-induced forest die-off is widespread in multiple biomes, strongly affecting the species composition, function and primary production in forest ecosystems. Hydraulic failure and carbon starvation in xylem sapwood are major hypotheses to explain drought-induced tree mortality. Because it is difficult to obtain enough field observations on drought-induced mortality in adult trees, the current understanding of the physiological mechanisms for tree die-offs is still controversial. However, the simultaneous examination of water and carbon uses throughout dehydration and rehydration processes in adult trees will contribute to clarify the roles of hydraulic failure and carbon starvation in tree wilting. Here we show the processes of the percent loss of hydraulic conductivity (PLC) and the content of nonstructural carbohydrates (NSCs) of distal branches in woody plants with contrasting water use strategy. Starch was converted to soluble sugar during PLC progression under drought, and the hydraulic conductivity recovered following water supply. The conversion of NSCs is strongly associated with PLC variations during dehydration and rehydration processes, indicating that stored carbon contributes to tree survival under drought; further carbon starvation can advance hydraulic failure. We predict that even slow-progressing drought degrades forest ecosystems via carbon starvation, causing more frequent catastrophic forest die-offs than the present projection. PMID:27079677

  11. Carbon monoxide-induced adventitious rooting of hypocotyl cuttings from mung bean seedling

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, the regulatory role of exogenous carbon monoxide (CO) during the generation and development of adventitious roots in mung bean (Phaseolus radiatus L. cv. Mingguang) hypocotyl cuttings was surveyed. The results indicated that, like nitric oxide (NO), CO donor Hematin induced adventitious rooting in dose- and time-de- pendent manners. These responses were also prov- en by the addition of gaseous CO aqueous solution with different concentrations. Additionally, the above CO-mediated effect was differently reversed when CO scavenger hemoglobin (Hb), CO specific synthetic inhibitor ZnPPIX, the auxin transport inhibitor NPA and nitric oxide synthase (NOS) inhibitor L-NAME were added with Hematin, respectively. Furthermore, after being treated with CO for 36 h, NO fluorescence was significantly enhanced and mainly distributed in the zone of vascular bundles whereas the specific NO scavenger cPTIO significantly inhibited NO fluorescence induced by CO, indicating that CO induces adventitious rooting of hypocotyl cuttings from mung bean seedling probably mediated by NO/NOS pathway.

  12. Mechanisms of carbon nanotube-induced toxicity: Focus on oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Shvedova, Anna A., E-mail: ats1@cdc.gov [Pathology and Physiology Research Branch, Health Effects Laboratory Division, National Institute for Occupational Safety and Health, University of Rome “Tor Vergata”, Rome (Italy); Department of Physiology and Pharmacology, West Virginia University, Morgantown, WV, University of Rome “Tor Vergata”, Rome (Italy); Pietroiusti, Antonio [Department of Biopathology, University of Rome “Tor Vergata”, Rome (Italy); Fadeel, Bengt [Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA (United States); Kagan, Valerian E. [Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA (United States)

    2012-06-01

    Nanotechnologies are emerging as highly promising technologies in many sectors in the society. However, the increasing use of engineered nanomaterials also raises concerns about inadvertent exposure to these materials and the potential for adverse effects on human health and the environment. Despite several years of intensive investigations, a common paradigm for the understanding of nanoparticle-induced toxicity remains to be firmly established. Here, the so-called oxidative stress paradigm is scrutinized. Does oxidative stress represent a secondary event resulting inevitably from disruption of biochemical processes and the demise of the cell, or a specific, non-random event that plays a role in the induction of cellular damage e.g. apoptosis? The answer to this question will have important ramifications for the development of strategies for mitigation of adverse effects of nanoparticles. Recent examples of global lipidomics studies of nanoparticle-induced tissue damage are discussed along with proteomics and transcriptomics approaches to achieve a comprehensive understanding of the complex and interrelated molecular changes in cells and tissues exposed to nanoparticles. We also discuss instances of non-oxidative stress-mediated cellular damage resulting from direct physical interference of nanomaterials with cellular structures. -- Highlights: ► CNT induced non-random oxidative stress associated with apoptosis. ► Non-oxidative mechanisms for cellular toxicity of carbon nanotubes. ► Biodegradation of CNT by cells of innate immune system. ► “Omics”-based biomarkers of CNT exposures.

  13. Surface-induced patterns from evaporating droplets of aqueous carbon nanotube dispersions

    KAUST Repository

    Zeng, Hongbo

    2011-06-07

    Evaporation of aqueous droplets of carbon nanotubes (CNTs) coated with a physisorbed layer of humic acid (HA) on a partially hydrophilic substrate induces the formation of a film of CNTs. Here, we investigate the role that the global geometry of the substrate surfaces has on the structure of the CNT film. On a flat mica or silica surface, the evaporation of a convex droplet of the CNT dispersion induces the well-known "coffee ring", while evaporation of a concave droplet (capillary meniscus) of the CNT dispersion in a wedge of two planar mica sheets or between two crossed-cylinder sheets induces a large area (>mm 2) of textured or patterned films characterized by different short- and long-range orientational and positional ordering of the CNTs. The resulting patterns appear to be determined by two competing or cooperative sedimentation mechanisms: (1) capillary forces between CNTs giving micrometer-sized filaments parallel to the boundary line of the evaporating droplet and (2) fingering instability at the boundary line of the evaporating droplet and subsequent pinning of CNTs on the surface giving micrometer-sized filaments of CNTs perpendicular to this boundary line. The interplay between substrate surface geometry and sedimentation mechanisms gives an extra control parameter for manipulating patterns of self-assembling nanoparticles at substrate surfaces. © 2011 American Chemical Society.

  14. Carbon Monoxide Alleviates Salt-Induced Oxidative Damage in Wheat Seedling Leaves

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Carbon monoxide (CO), a by-product released during the degradation of heme by heme oxygenases (EC 1.14.99.3) in animals, is regarded as an important physiological messenger or bioactive molecule involved in many biological events that has been recently reported as playing a major role in mediating the cytoprotection against oxidant-induced lung injury. In the present study, we first determined the protective effect of exogenous CO against salt-induced oxidative damage in wheat seedling leaves. Wheat seedlings treated with 0.01 μmol/L hematin as the CO donor demonstrated significant reversal of chlorophyll decay, dry weight, and water loss induced by 300 mmol/L NaCI stress. Interestingly, the increase in lipid peroxidation observed in salt-treated leaves was reversed by 0.01 μmol/L hematin treatment. Time-course analyses showed that application of 0.01μmol/L hematin enhanced guaiacol peroxidase, superoxide dismutase, ascorbate peroxidase and catalase activities in wheat seedling leaves subjected to salt stress. These effects are specific for CO because the CO scavenger hemoglobin (1.2 mg/L) blocked the actions of the CO donor hematin. However, higher concentration of the CO donor (1.0 μmol/L) did not alleviate dry weight and water loss of salt-stressed wheat seedlings. These results suggest that exogenous application of low levels of a CO donor may be advantageous against salinity toxicity.

  15. Carrier dynamics and design optimization of electrolyte-induced inversion layer carbon nanotube-silicon Schottky junction solar cell

    Science.gov (United States)

    Chen, Wenchao; Seol, Gyungseon; Rinzler, Andrew G.; Guo, Jing

    2012-03-01

    Carrier dynamics of the electrolyte-induced inversion layer carbon nanotube-silicon Schottky junction solar cells is explored by numerical simulations. Operation mechanisms of the solar cells with and without the electrolyte-induced inversion layer are presented and compared, which clarifies the current flow mechanisms in a solar cell with an induced inversion layer. A heavily doped back contact layer can behave as a hole block layer. In addition to lowering contact resistance and surface recombination, it is particularly useful for improving carrier separation in an electrolyte-induced inversion layer solar cell or a metal-insulator-semiconductor grating solar cell.

  16. Uncovering the pKa dependent fluorescence quenching of carbon dots induced by chlorophenols

    Science.gov (United States)

    Zhang, Yu; Wang, Yu; Guan, Yafeng; Feng, Liang

    2015-03-01

    Fluorescence quenching induced by targets is always an alluring strategy to elucidate the possible photoluminescence origin of carbon dots. In this study, a new kind of N, S co-doped carbon dots (NSCDs) was synthesized and the fluorescence of NSCDs was surprisingly found to be quenched by chlorophenols (CPs) in a pKa dependent mode. Detailed investigation of this behavior demonstrated that phenolate was the responsible species and N and/or S dopants in NSCDs failed to play a role in the fluorescence quenching. Further evidence uncovered that the quenching was a static one, where a non-fluorescent intermediate was formed between electron-deficient C&z.dbd;O on the CDs surface and the electron-rich phenolic oxygen anion of chlorophenolate via nucleophilic addition. Moreover, one of the main photoluminescence origins of this kind of CDs was derived, namely surface emissive sites mostly attributed to carbonyl groups.Fluorescence quenching induced by targets is always an alluring strategy to elucidate the possible photoluminescence origin of carbon dots. In this study, a new kind of N, S co-doped carbon dots (NSCDs) was synthesized and the fluorescence of NSCDs was surprisingly found to be quenched by chlorophenols (CPs) in a pKa dependent mode. Detailed investigation of this behavior demonstrated that phenolate was the responsible species and N and/or S dopants in NSCDs failed to play a role in the fluorescence quenching. Further evidence uncovered that the quenching was a static one, where a non-fluorescent intermediate was formed between electron-deficient C&z.dbd;O on the CDs surface and the electron-rich phenolic oxygen anion of chlorophenolate via nucleophilic addition. Moreover, one of the main photoluminescence origins of this kind of CDs was derived, namely surface emissive sites mostly attributed to carbonyl groups. Electronic supplementary information (ESI) available: Texts, figures and tables giving partial experimental procedures, detailed characterizations

  17. Critical role of surface chemical modifications induced by length shortening on multi-walled carbon nanotubes-induced toxicity

    Directory of Open Access Journals (Sweden)

    Bussy Cyrill

    2012-11-01

    Full Text Available Abstract Given the increasing use of carbon nanotubes (CNT in composite materials and their possible expansion to new areas such as nanomedicine which will both lead to higher human exposure, a better understanding of their potential to cause adverse effects on human health is needed. Like other nanomaterials, the biological reactivity and toxicity of CNT were shown to depend on various physicochemical characteristics, and length has been suggested to play a critical role. We therefore designed a comprehensive study that aimed at comparing the effects on murine macrophages of two samples of multi-walled CNT (MWCNT specifically synthesized following a similar production process (aerosol-assisted CVD, and used a soft ultrasonic treatment in water to modify the length of one of them. We showed that modification of the length of MWCNT leads, unavoidably, to accompanying structural (i.e. defects and chemical (i.e. oxidation modifications that affect both surface and residual catalyst iron nanoparticle content of CNT. The biological response of murine macrophages to the two different MWCNT samples was evaluated in terms of cell viability, pro-inflammatory cytokines secretion and oxidative stress. We showed that structural defects and oxidation both induced by the length reduction process are at least as responsible as the length reduction itself for the enhanced pro-inflammatory and pro-oxidative response observed with short (oxidized compared to long (pristine MWCNT. In conclusion, our results stress that surface properties should be considered, alongside the length, as essential parameters in CNT-induced inflammation, especially when dealing with a safe design of CNT, for application in nanomedicine for example.

  18. Variable involvement of the perivascular retinal tissue in carbonic anhydrase inhibitor induced relaxation of porcine retinal arterioles in vitro

    DEFF Research Database (Denmark)

    Kehler, Anne Katrine; Holmgaard, Kim; Hessellund, Anders;

    2007-01-01

    PURPOSE: Inhibition of carbonic anhydrase in the eye is an important treatment modality for reducing the intraocular pressure in glaucoma. However, evidence suggests that carbonic anhydrase inhibition also exerts a relaxing effect on the vessels in the optic nerve, and it has been suggested......, and the vasodilating effect of acetazolamide almost disappeared. CONCLUSIONS: A further elucidation of the mechanisms of action of carbonic anhydrase-induced dilation of retinal arterioles may contribute to a better understanding of the regulation of retinal blood flow. The perivascular retinal tissue may play...... a significant role in diameter control of retinal arterioles. Udgivelsesdato: 2007-Oct...

  19. Raman Spectroscopy of Irradiation Effect in Three Carbon Allotropes Induced by Low Energy B Ions

    Institute of Scientific and Technical Information of China (English)

    FU Yun-Chong; JIN Yun-Fan; YAO Cun-Feng; ZHANG Chong-Hong

    2009-01-01

    Irradiation effect in three carbon allotropes C6o, diamond and highly oriented pyrolytic graphite (HOPG) induced by 170 keV B ions, mainly including the process of the damage creation, is investigated by means of Rarnan spectroscopy technique. The differences on irradiation sensitivity and structural stability for C6o, HOPG and diamond are compared. The analysis results indicate that C6o is the most sensitive for B ions irradiation, diamond is the second one and the structure of HOPG is the most stable under B ion irradiation. The damage cross sections σ of C6o, diamond and HOPG deduced from the Raman spectra are 7.78 × 10-15, 6.38 × 10-15 and 1.31 × 10-15 cm-2, respectively.

  20. Electric-Field Induced Activation of Dark Excitonic States in Carbon Nanotubes.

    Science.gov (United States)

    Uda, T; Yoshida, M; Ishii, A; Kato, Y K

    2016-04-13

    Electrical activation of optical transitions to parity-forbidden dark excitonic states in individual carbon nanotubes is reported. We examine electric-field effects on various excitonic states by simultaneously measuring photocurrent and photoluminescence. As the applied field increases, we observe an emergence of new absorption peaks in the excitation spectra. From the diameter dependence of the energy separation between the new peaks and the ground state of E11 excitons, we attribute the peaks to the dark excited states which became optically active due to the applied field. Field-induced exciton dissociation can explain the photocurrent threshold field, and the edge of the E11 continuum states has been identified by extrapolating to zero threshold. PMID:26999284

  1. Study of deformation-induced phase transformation in plain low carbon steel at low strain rate

    International Nuclear Information System (INIS)

    Hot-deformation behavior of super-cooled austenite within the austenite-ferrite (γ-α) phase field was studied in low carbon steels (0.15 wt.%) at various strain rates. Flow softening was observed during the hot-deformation at temperatures lower than critical temperature. The critical temperature was observed to be significantly higher than T0 temperature. This was due to large shift of γ-α phase-equilibrium to a higher temperature during hot-deformation. A thermodynamic model to account the effect of non-uniform deformation-induced stress on the γ-α phase-equilibrium during hot-deformation was proposed and its prediction was in good agreement with the experimentally measured critical temperature.

  2. Selected durability studies of geopolymer concrete with respect to carbonation, elevated temperature, and microbial induced corrosion

    Science.gov (United States)

    Badar, Mohammad Sufian

    This thesis reports a comprehensive study related to the experimental evaluation of carbonation in reinforced geopolymer concrete, the evaluation of geopolymer concretes at elevated temperature, and the resistance of geopolymer concrete to microbial induced corrosion (MIC). Carbonation: Reinforced concretes, made of geopolymer, prepared from two class F fly ashes and one class C fly ash, were subjected to accelerated carbonation treatment for a period of 450 days. Electrochemical, microstructure and pore structure examinations were performed to evaluate the effect of corrosion caused due to carbonation. GPC specimens prepared from class F fly ash exhibited lower corrosion rates by a factor of 21, and higher pH values (pH>12) when compared with concrete specimens prepared from class C Fly ash (GPCMN). Microstructure and pore characterization of GPC prepared using class F fly ash revealed lower porosity by a factor of 2.5 as compared with thier counterparts made using GPC-MN. The superior performace of GPC prepared with the class F fly ash could be attributed to the dense pore structure and formation of the protective layer of calcium and sodium alumino silicate hydrates (C/N-A-S-H) geopolymeric gels around the steel reinforcement. Elevated Temperature: Geopolymers are an emerging class of cementitious binders which possess a potential for high temperature resistance that could possibly be utilized in applications such as nozzles, aspirators and refractory linings. This study reports on the results of an investigation into the performance of a fly ash based geopolymer binder in high temperature environments. Geopolymer concrete (GPC) was prepared using eleven types of fly ashes obtained from four countries. High content alumina and silica sand was used in the mix for preparing GPC. GPC was subjected to thermal shock tests following ASTM C 1100-88. The GPC samples prepared with tabular alumina were kept at 1093° C and immediately quenched in water. GPC specimens

  3. Mechanism of electrolyte-induced brightening in single-wall carbon nanotubes.

    Science.gov (United States)

    Duque, Juan G; Oudjedi, Laura; Crochet, Jared J; Tretiak, Sergei; Lounis, Brahim; Doorn, Stephen K; Cognet, Laurent

    2013-03-01

    While addition of electrolyte to sodium dodecyl sulfate suspensions of single-wall carbon nanotubes has been demonstrated to result in significant brightening of the nanotube photoluminescence (PL), the brightening mechanism has remained unresolved. Here, we probe this mechanism using time-resolved PL decay measurements. We find that PL decay times increase by a factor of 2 on addition of CsCl as the electrolyte. Such an increase directly parallels an observed near-doubling of PL intensity, indicating the brightening results primarily from changes in nonradiative decay rates associated with exciton diffusion to quenching sites. Our findings indicate that a reduced number of these sites results from electrolyte-induced reorientation of the surfactant surface structure that partially removes pockets of water from the tube surface where excitons can dissociate, and thus underscores the contribution of interfacial water in exciton recombination processes.

  4. Oscillation control of carbon nanotube mechanical resonator by electrostatic interaction induced retardation

    Science.gov (United States)

    Yasuda, Masaaki; Takei, Kuniharu; Arie, Takayuki; Akita, Seiji

    2016-01-01

    Despite the superb intrinsic properties of carbon nanotube mechanical resonators, the quality factors at room temperature are 1,000 or less, even in vacuum, which is much lower than that of mechanical resonators fabricated using a top-down approach. This study demonstrates the improvement of the quality factor and the control of nonlinearity of the mechanical resonance of the cantilevered nanotube by electrostatic interaction. The apparent quality factor of the nanotube supported by insulator is improved drastically from approximately 630 to 3200 at room temperature. Results show that retardation of the electrostatic force induced by the contact resistance between the nanotube and the insulator support improves the quality factor. Finite element method calculation reveals that the nonuniform pileup charge on the insulator support strongly influences the nonlinearity of the resonance. PMID:26935657

  5. Structure Evolution of Ordered Mesoporous Carbons Induced by Water Content of Mixed Solvents Water/Ethanol.

    Science.gov (United States)

    Li, Peng; Liang, Shujun; Li, Zhenzhong; Zhai, Yan; Song, Yan

    2016-12-01

    In this work, mesostructure evolution of ordered mesoporous carbons (OMCs) from the 2-D hexagonal (space group p6mm) to the discontinuous cubic [Formula: see text], then towards the face-centered cubic lattice [Formula: see text], and finally, to the simple cubic Pm3n is achieved by simply adjusting the cosolvent water content of the mixed solvents water/ethanol in the presence of a reverse nonionic triblock copolymer and low molecular resin by evaporation-induced self-assembly method. Experimental results demonstrate that both the cosolvent and the reverse triblock copolymer play a key role in the mesophase transitions of OMCs. Furthermore, the OMCs with Pm3n symmetry are reported for the first time. Finally, the mechanism of mesostructure transition was discussed and proposed. PMID:27518232

  6. DOSE TO RADIOLOGICAL TECHNOLOGISTS FROM INDUCED RADIONUCLIDES IN CARBON ION RADIOTHERAPY.

    Science.gov (United States)

    Yonai, S; Spano, V

    2016-09-01

    Radioactive nuclides are induced in irradiation devices and patients during high-energy photon and ion beam radiotherapies. These nuclides potentially become sources of exposure to radiation workers. Radiological technologists (RTs) are often required to enter an irradiation room and approach activated devices and patients. In this study, annual doses to RTs working in a carbon ion radiotherapy facility were estimated based on measurements with the Si-semiconductor personal dosemeter. In addition, the time decay of dose around a patient couch after irradiation was obtained by phantom experiments. The annual Hp(10) values for passive and scanned beams were estimated to be 61 and 2 μSv, respectively, when assuming the number of treatments in 2013. These are much lower than the ICRP recommended dose limit for radiation workers. The time-series data of dose to RTs during their work and the time decay of the dose should be helpful for reducing their dose further. PMID:27179122

  7. Lysosomal membrane permeabilization: Carbon nanohorn-induced reactive oxygen species generation and toxicity by this neglected mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Mei, E-mail: happy_deercn@163.com [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Zhang, Minfang; Tahara, Yoshio; Chechetka, Svetlana; Miyako, Eijiro [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Iijima, Sumio [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan); Faculty of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tenpaku, Nagoya 468-8502 (Japan); Yudasaka, Masako, E-mail: m-yudasaka@aist.go.jp [Nanotube Research Center, National Institute of Advanced Industrial Science and Technology 5-2, 1-1-1 Higashi, Tsukuba 305-8565 (Japan)

    2014-10-01

    Understanding the molecular mechanisms responsible for the cytotoxic effects of carbon nanomaterials is important for their future biomedical applications. Carbon nanotubular materials induce the generation of reactive oxygen species (ROS), which causes cell death; however, the exact details of this process are still unclear. Here, we identify a mechanism of ROS generation that is involved in the apoptosis of RAW264.7 macrophages caused by excess uptake of carbon nanohorns (CNHs), a typical type of carbon nanotubule. CNH accumulated in the lysosomes, where they induced lysosomal membrane permeabilization (LMP) and the subsequent release of lysosomal proteases, such as cathepsins, which in turn caused mitochondrial dysfunction and triggered the generation of ROS in the mitochondria. The nicotinamide adenine dinucleotide phosphate oxidase was not directly involved in CNH-related ROS production, and the ROS generation cannot be regulated by mitochondrial electron transport chain. ROS fed back to amplify the mitochondrial dysfunction, leading to the subsequent activation of caspases and cell apoptosis. Carbon nanotubules commonly accumulate in the lysosomes after internalization in cells; however, lysosomal dysfunction has not attracted much attention in toxicity studies of these materials. These results suggest that LMP, a neglected mechanism, may be the primary reason for carbon nanotubule toxicity. - Highlights: • We clarify an apoptotic mechanism of RAW264.7 cells caused by carbon nanohorns. • In the meantime, the mechanism of CNH-induced ROS generation is identified. • LMP is the initial factor of CNH-induced ROS generation and cell death. • Cathepsins work as mediators that connect LMP and mitochondrial dysfunction.

  8. Reactive Transport Modeling of CO2-induced Porosity and Permeability Changes in Heterogeneous Carbonate Rocks

    Science.gov (United States)

    Hao, Y.; Smith, M. M.; Mason, H. E.; Carroll, S.

    2015-12-01

    It has long been appreciated that chemical interactions have a major effect on rock porosity and permeability evolution and may alter the behavior or performance of both natural and engineered reservoir systems. Such reaction-induced permeability evolution is of particular importance for geological CO2 sequestration and storage associated with enhanced oil recovery. In this study we used a three-dimensional Darcy scale reactive transport model to simulate CO2 core flood experiments in which the CO2-equilibrated brine was injected into dolostone cores collected from the Arbuckle carbonate reservoir, Wellington, Kansas. Heterogeneous distributions of macro pores, fractures, and mineral phases inside the cores were obtained from X-ray computed microtomography (XCMT) characterization data, and then used to construct initial model macroscopic properties including porosity, permeability, and mineral compositions. The reactive transport simulations were performed by using the Nonisothermal Unsaturated Flow and Transport (NUFT) code, and their results were compared with experimental data. It was observed both experimentally and numerically that the dissolution fronts became unstable in highly heterogeneous and less permeable formations, leading to the development of highly porous flow paths or wormholes. Our model results indicate that the continuum-scale reactive transport models are able to adequately capture the evolution of distinct dissolution fronts as observed in carbonate rocks at a core scale. The impacts of rock heterogeneity, chemical kinetics and porosity-permeability relationships were also examined in this study. The numerical model developed in this study will not only help improve understanding of coupled physical and chemical processes controlling carbonate dissolution, but also provide a useful basis for upscaling transport and reaction properties from core scale to field scale. This work was performed under the auspices of the U.S. Department of Energy

  9. MgAl2O4 spinel: Synthesis, carbon incorporation and defect-induced luminescence

    Science.gov (United States)

    Raj, Sanu S.; Gupta, Santosh K.; Grover, V.; Muthe, K. P.; Natarajan, V.; Tyagi, A. K.

    2015-06-01

    The present work explores the synthesis of carbon-doped MgAl2O4 and investigates the effect of doping on the photophysical properties of MgAl2O4. Pure MgAl2O4 spinel was synthesized by gel combustion followed by annealing at 1100 °C. The carbon doping was performed by two methods. The first method involved heating the sample with electron beam (from electron gun) in graphite crucible (A) and second method involved heating the sample up to 2100 °C in graphite furnace (B). The photoluminescence spectroscopy exhibited defect-induced emissions with enhanced intensity in the case of sample B. A significant blue shift in the emission band was also observed in the case of sample B. The photoluminescence decay studies indicated that multiple trapping and detrapping events are experienced before the radiative recombination process, which eventually occurs. Average lifetime was observed to be 4.83 μs which is typical of defect-related emission. The results were complimented by electron paramagnetic resonance (EPR) technique. The CIE co-ordinates for sample B were found to be x = 0.231 and y = 0.227 which establish it as a blue-emitter.

  10. Carbon nanotubes induce inflammation but decrease the production of reactive oxygen species in lung.

    Science.gov (United States)

    Crouzier, D; Follot, S; Gentilhomme, E; Flahaut, E; Arnaud, R; Dabouis, V; Castellarin, C; Debouzy, J C

    2010-06-01

    With the rapid spread of carbon nanotubes (CNTs) applications, the respiratory toxicity of these compounds has attracted the attention of many scientists. Several studies have reported that after lung administration, CNTs could induce granuloma, fibrosis, or inflammation. By comparison with the mechanisms involved with other toxic particles such as asbestos, this effect could be attributed to an increase of oxidative stress. The aim of the present work was to test this hypothesis in vivo. Mice were intranasally instilled with 1.5mg/kg of double walled carbon nanotubes (DWCNTs). Six, 24, or 48h after administration, inflammation and localisation of DWCNTs in lungs were microscopically observed. Local oxidative perturbations were investigated using ESR spin trapping experiments, and systemic inflammation was assessed by measuring the plasma concentration of cytokines TNF-alpha, IL-1alpha, IL-1beta, IL-6, IGF-1, Leptin, G-CSF, and VEGF. Examination of lungs and the elevation of proinflammatory cytokines in the plasma (Leptin and IL-6 at 6h) confirmed the induction of an inflammatory reaction. This inflammatory reaction was accompanied by a decrease in the local oxidative stress. This effect could be attributed to the scavenger capability of pure CNTs.

  11. Biotic and abiotic effects on CO2 sequestration during microbially-induced calcium carbonate precipitation.

    Science.gov (United States)

    Okyay, Tugba Onal; Rodrigues, Debora F

    2015-03-01

    In this study, CO2 sequestration was investigated through the microbially-induced calcium carbonate precipitation (MICP) process with isolates obtained from a cave called 'Cave Without A Name' (Boerne, TX, USA) and the Pamukkale travertines (Denizli, Turkey). The majority of the bacterial isolates obtained from these habitats belonged to the genera Sporosarcina, Brevundimonas, Sphingobacterium and Acinetobacter. The isolates were investigated for their capability to precipitate calcium carbonate and sequester CO2. Biotic and abiotic effects of CO2 sequestration during MICP were also investigated. In the biotic effect, we observed that the rate and concentration of CO2 sequestered was dependent on the species or strains. The main abiotic factors affecting CO2 sequestration during MICP were the pH and medium components. The increase in pH led to enhanced CO2 sequestration by the growth medium. The growth medium components, on the other hand, were shown to affect both the urease activity and CO2 sequestration. Through the Plackett-Burman experimental design, the most important growth medium component involved in CO2 sequestration was determined to be urea. The optimized medium composition by the Plackett-Burman design for each isolate led to a statistically significant increase, of up to 148.9%, in CO2 uptake through calcification mechanisms. PMID:25764465

  12. Impacts of natural and human-induced disturbances on carbon dynamics in Northern Eurasia

    Science.gov (United States)

    Shvidenko, A.; Shchepashchenko, D.

    2012-12-01

    Disturbance regimes (DR) of vegetation ecosystems of Northern Eurasia (NE, limited to Russian territories) are represented by complicated and interacting sets of natural and human-induced disturbances (D). We present a unified classification of D and DR in major land cover classes of Northern Eurasia (forests, agriculture, wetlands, shrubs & grasses), their connections to succession regularities, and minimal informative set of indicators, which are able to describe both specifics of individual types of D and their impacts on annual carbon budget. The assessment of extent, severity and consequences of D was done based on an Integrated Land Information System for Russia, which accumulated all relevant spatially distributed information including multi-sensor and multi-temporal remote sensing concept, in situ measurements and ground data from diverse inventories and surveys. Major emissions caused by D are produced by consumption of plant products (agriculture and forestry), wild fire, and biotic D (basically insect outbreaks). For example, the annual flux due to human consumption of plant products is estimated at 170 Tg C yr-1. Wild fire in 1998-2010 enveloped 106.9 x 106 ha-1, on average 8.23 x 106 ha-1 yr-1, with variation from 4.2 to 17.3 x 106 ha-1 yr-1. Average direct carbon emissions due to wildfire were estimated to be at 121.0 Tg C yr-1, including 84.6% as C-CO2, 8.2% C-CO, C-CH4 - 1.1%, C-NMHC - 1.2%, organic carbon - 1.2% and black carbon - 0.1%, particulate matter 3.5%, of which PM2.5 - 1.2%. About 2/3 of burnt area and carbon emissions were on forest land. While the area of fire on wetlands was only 7.3%, this land class delivered 15.2% of the total fire emissions. Emissions caused by biotic D (accounted for forests only) is estimated at 50.8 Tg C yr-1. Overall, direct emissions due to D amounted at about 350 Tg C yr-1, or ~7% of annual Net Primary Production of terrestrial ecosystems of Russia. These data do not include long-term consequences of D, which

  13. A comparative investigation on strain induced crystallization for graphene and carbon nanotubes filled natural rubber composites

    Directory of Open Access Journals (Sweden)

    D. H. Fu

    2015-07-01

    Full Text Available Natural rubber containing graphene and carbon nanotubes (CNTs composites were prepared by ultrasonicallyassisted latex mixing. Natural rubber filled by both graphene and CNTs show significant enhanced tensile strength, while graphene exhibits a better reinforcing effect than CNTs. Strain-induced crystallization in natural rubber composites during stretching was determined by synchrotron wide-angle X-ray diffraction. With the addition of CNTs or graphene, the crystallization for natural rubber occurs at a lower strain compared to unfilled natural rubber, and the strain amplification effects were observed. The incorporation of graphene results in a faster strain-induced crystallization rate and a higher crystallinity compared to CNTs. The entanglement-bound rubber tube model was used to analyze the chain network structure and determine the network parameters of composites. The results show that the addition of graphene or CNTs has an influence on the molecular network structure and improves the contribution of entanglement to the conformational constraint, while graphene has a more marked effect than CNTs.

  14. Strain-induced photoconductivity in thin films of Co doped amorphous carbon.

    Science.gov (United States)

    Jiang, Y C; Gao, J

    2014-01-01

    Traditionally, strain effect was mainly considered in the materials with periodic lattice structure, and was thought to be very weak in amorphous semiconductors. Here, we investigate the effects of strain in films of cobalt-doped amorphous carbon (Co-C) grown on 0.7PbMg(1/3)Nb(2/3)O3-0.3PbTiO3 (PMN-PT) substrates. The electric transport properties of the Co-C films were effectively modulated by the piezoelectric substrates. Moreover, we observed, for the first time, strain-induced photoconductivity in such an amorphous semiconductor. Without strain, no photoconductivity was observed. When subjected to strain, the Co-C films exhibited significant photoconductivity under illumination by a 532-nm monochromatic light. A strain-modified photoconductivity theory was developed to elucidate the possible mechanism of this remarkable phenomenon. The good agreement between the theoretical and experimental results indicates that strain-induced photoconductivity may derive from modulation of the band structure via the strain effect. PMID:25338641

  15. Particle number scaling for diffusion-induced dissipation in graphene and carbon nanotube nanomechanical resonators

    Science.gov (United States)

    Rhén, Christin; Isacsson, Andreas

    2016-03-01

    When a contaminant diffuses on the surface of a nanomechanical resonator, the motions of the two become correlated. Despite being a high-order effect in the resonator-particle coupling, such correlations affect the system dynamics by inducing dissipation of the resonator energy. Here, we consider this diffusion-induced dissipation in the cases of multiple particles adsorbed on carbon nanotube and graphene resonators. By solving the stochastic equations of motion, we simulate the ringdown of the resonator, in order to determine the resonator energy decay rate. We find two different scalings with the number of adsorbed particles K and particle mass m . In the regime where the adsorbates are inertially trapped at an antinode of vibration, the dissipation rate Γ scales with the total adsorbed mass Γ ∝K m . In contrast, in the regime where particles diffuse freely over the resonator, the dissipation rate scales as the product of the total adsorbed mass and the individual particle mass: Γ ∝K m2 .

  16. Spectroscopic and MD simulation studies on unfolding processes of mitochondrial carbonic anhydrase VA induced by urea.

    Science.gov (United States)

    Idrees, Danish; Prakash, Amresh; Haque, Md Anzarul; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2016-09-01

    Carbonic anhydrase VA (CAVA) is primarily expressed in the mitochondria and involved in numerous physiological processes including lipogenesis, insulin secretion from pancreatic cells, ureagenesis, gluconeogenesis and neuronal transmission. To understand the biophysical properties of CAVA, we carried out a reversible urea-induced isothermal denaturation at pH 7.0 and 25°C. Spectroscopic probes, [θ]222 (mean residue ellipticity at 222 nm), F344 (Trp-fluorescence emission intensity at 344 nm) and Δε280 (difference absorption at 280 nm) were used to monitor the effect of urea on the structure and stability of CAVA. The urea-induced reversible denaturation curves were used to estimate [Formula: see text], Gibbs free energy in the absence of urea; Cm, the mid-point of the denaturation curve, i.e. molar urea concentration ([urea]) at which ΔGD = 0; and m, the slope (=∂ΔGD/∂[urea]). Coincidence of normalized transition curves of all optical properties suggests that unfolding/refolding of CAVA is a two-state process. We further performed 40 ns molecular dynamics simulation of CAVA to see the dynamics at different urea concentrations. An excellent agreement was observed between in silico and in vitro studies.

  17. Damage induced by proton irradiation in carbonate based natural painting pigments

    International Nuclear Information System (INIS)

    The so called 'dark spot' phenomenon produced during proton irradiation of pigments is an important factor to determine experimental conditions of ion beam analysis of pigments in paintings, miniatures, pottery and other art objects. Recently it has been suggested that this phenomenon could be due to the formation of colour centres during irradiation, but there is scarce knowledge about the characteristics and the reversibility of the damage. In this work a representative set of natural carbonate minerals, traditionally used as pigments, were exposed to proton irradiation in an external beam set-up, in order to simulate routine external proton induced X-ray emission (PIXE) analysis conditions of an art object. During irradiation ionoluminescence (IL) combined with PIXE were employed to identify the microscopic processes involved in the proton damage. After irradiation, two well-established techniques for the study of colour centres, thermoluminescence (TL) and optical absorption were used. Particularly, TL is a very sensitive technique to detect very low concentrations of radiation induced defects

  18. Biologically Induced Hydrogen Production Drives High Rate/High Efficiency Microbial Electrosynthesis of Acetate from Carbon Dioxide

    NARCIS (Netherlands)

    Jourdin, Ludovic; Lu, Yang; Flexer, Victoria; Keller, Jurg; Freguia, Stefano

    2016-01-01

    Electron-transfer pathways occurring in biocathodes are still unknown. We demonstrate here that high rates of acetate production by microbial electrosynthesis are mainly driven by an electron flux from the electrode to carbon dioxide, occurring via biologically induced hydrogen, with (99±1)% elec

  19. Carbon monoxide induced PPARγ SUMOylation and UCP2 block inflammatory gene expression in macrophages.

    Directory of Open Access Journals (Sweden)

    Arvand Haschemi

    Full Text Available Carbon monoxide (CO dampens pro-inflammatory responses in a peroxisome proliferator-activated receptor-γ (PPARγ and p38 mitogen-activated protein kinase (MAPK dependent manner. Previously, we demonstrated that CO inhibits lipopolysaccharide (LPS-induced expression of the proinflammatory early growth response-1 (Egr-1 transcription factor in macrophages via activation of PPARγ. Here, we further characterize the molecular mechanisms by which CO modulates the activity of PPARγ and Egr-1 repression. We demonstrate that CO enhances SUMOylation of PPARγ which we find was attributed to mitochondrial ROS generation. Ectopic expression of a SUMOylation-defective PPARγ-K365R mutant partially abolished CO-mediated suppression of LPS-induced Egr-1 promoter activity. Expression of a PPARγ-K77R mutant did not impair the effect of CO. In addition to PPARγ SUMOylation, CO-activated p38 MAPK was responsible for Egr-1 repression. Blocking both CO-induced PPARγ SUMOylation and p38 activation, completely reversed the effects of CO on inflammatory gene expression. In primary macrophages isolated form C57/BL6 male mice, we identify mitochondrial ROS formation by CO as the upstream trigger for the observed effects on Egr-1 in part through uncoupling protein 2 (UCP2. Macrophages derived from bone marrow isolated from Ucp2 gene Knock-Out C57/BL6 mice (Ucp2(-/-, produced significantly less ROS with CO exposure versus wild-type macrophages. Moreover, absence of UCP2 resulted in a complete loss of CO mediated Egr-1 repression. Collectively, these results indentify p38 activation, PPARγ-SUMOylation and ROS formation via UCP2 as a cooperative system by which CO impacts the inflammatory response.

  20. ENDOGENOUS HEME OXYGENASE/CARBON MONOXIDE SYSTEM MEDIATES LIPOPOLYSACCHARIDE- INDUCED INTUSSUSCEPTION IN RATS

    Institute of Scientific and Technical Information of China (English)

    王平; 余奇志; 欧和生; 佟利家; 杨军; 唐朝枢

    2000-01-01

    Objectives. To investigate the role d endogenous heine oxygenase ( HO )/carbon monoxide ( CO ) system in regulating the process of intussusception (IN) induced by administration of lipopolysaccharide (LPS) in rats. Methods. IN model of rats were induced by lipopolysaccharide. HO activity was determined by the amonnl of bilirubin formation which was measured with a double-beam spectrophotometer, and HbCO formation was measured by CO-aximeter. Results. The results showed that LPS (10mg/kg) caused IN in up to 40% d the rats at 6h after treatment of LPS. The incidence dIN were significantly increased by50% (P<0.05) and by83.2%(P<0.01) in HO substrate (heme-L-lysinate)-treated rats and in exogenous CO-treated rats, respectively; but it was significantly decreased by 41.8%(P <0.05) after administration dZnDPBG, an inhibitor dheme oxygenase (HO) activity. Furthermore, LPS increased HO activity, HbCO formation cGMP content within colic smooth muscle and the plasma level d cGMP, and these parameters were significantly elevated by 62.6% (P < 0.01), 40.0% (P < 0.01), 49.3% (P < 0.05) and 38.9%(P< 0.05), respectively, compared with LPS-non-IN rats. Conclusion. It is suggested that endogenous HO/CO system plays an important role in the process d IN induced by LPS, and inhibition d HO activity may decrease the formation of IN.

  1. ENDOGENOUS HEME OXYGENASE/CARBON MONOXIDE SYSTEM MEDIATES LIPOPOLYSACCHARIDE-INDUCED INTUSSUSCEPTION IN RATS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objectives. To investigate the role of endogenous heme oxygenase (HO)/carbon monoxide (CO) system in regulating the process of intussusception (IN) induced by administration of lipopolysaccharide (LPS) in rats.Methods. IN model of rats were induced by lipopolysaccharide. HO activity was determined by the amount of bilirubin formation which was measured with a double-beam spectrophotometer, and HbCO formation was measured by CO-oximeter.Results. The results showed that LPS (10mg/kg) caused IN in up to 40% of the rats at 6h after treatment of LPS. The incidence of IN were significantly increased by 50% (P<0.05) and by 83.2%(P<0.01) in HO substrate(heme-L-lysinate)-treated rats and in exogenous CO-treated rats, respectively; but it was significantly decreased by 41.8%(P<0.05) after administration of ZnDPBG, an inhibitor of heme oxygenase (HO) activity. Furthermore, LPS increased HO activity, HbCO formation cGMP content within colic smooth muscle and the plasma level of cGMP, and these parameters were significantly elevated by 62.6%(P<0.01), 40.0%(P<0.01), 49.3%(P<0.05) and 38.9%(P<0.05), respectively, compared with LPS-non-IN rats.Conclusion. It is suggested that endogenous HO/CO system plays an important role in the process of IN induced by LPS, and inhibition of HO activity may decrease the formation of IN.

  2. Highly purified, multi-wall carbon nanotubes induce light-chain 3B expression in human lung cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsukahara, Tamotsu, E-mail: ttamotsu@kanazawa-med.ac.jp [Department of Hematology and Immunology, Kanazawa Medical University, 1-1 Daigaku, Uchinada, Ishikawa 920-0293 (Japan); Matsuda, Yoshikazu [Clinical Pharmacology Educational Center, Nihon Pharmaceutical University, Ina-machi, Saitama 362-0806 (Japan); Usui, Yuki [Research Center for Exotic Nanocarbons, Shinshu University, 4-17-1 Wakasato, Nagano-shi, Nagano 380-8553 (Japan); Haniu, Hisao [Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621 (Japan)

    2013-10-18

    Highlights: •HTT2800-treated BEAS-2B cells induced LC3B in a time-dependent manner. •HTT2800-treated BEAS-2B cells showed decreased cell proliferation that was both time- and dose-dependent. •Addition of 3-MA, LC3B-II protein and mRNA levels were significantly decreased. •3-MA and E64-d + pepstatin A, but not brefeldin A, provided protection against HTT2800-induced cell death. •These results suggest that HTT2800 predominantly causes autophagy rather than apoptotic cell death in BEAS-2B cells. -- Abstract: Bronchial epithelial cells are targets of inhalation and play a critical role in the maintenance of mucosal integrity as mechanical barriers against various particles. Our previous result suggest that vapor-grown carbon fiber, HTT2800, which is one of the most highly purified multi-wall carbon nanotubes (MWCNT) showed cellular uptake of the carbon nanotube, increased cell death, enhanced DNA damage, and induced cytokine release. Increasing evidence suggests that autophagy may critically influence vital cellular processes such as apoptosis, cell proliferation and inflammation and thereby may play a critical role in pulmonary diseases. Autophagy was recently recognized as a critical cell death pathway, and autophagosome accumulation has been found to be associated with the exposure of various nanoparticles. In this study, the authors focus on the autophagic responses of HTT2800 exposure. The HTT2800-exposed cells induced LC3B expression and induced cell growth inhibition.

  3. A system to investigate the remediation of organic vapors using microwave-induced plasma with fluidized carbon granules

    Science.gov (United States)

    Dawson, Elizabeth A.; Parkes, Gareth M. B.; Bond, Gary; Mao, Runjie

    2009-03-01

    This article describes a system to investigate the parameters for the remediation of organic vapors using microwave-induced plasma on fluidized carbon granules. The system is based on a single mode microwave apparatus with a variable power (2.45 GHz) generator. Carbon granules are fluidized in a silica tube situated in the sample section of a waveguide incorporating two additional ports to allow plasma intensity monitoring using a light sensor and imaging with a digital camera. A fluoroptic probe is used for in situ measurement of the carbon granule temperature, while the effluent gas temperature is measured with a thermocouple situated in the silica tube outside the cavity. Data acquisition and control software allow experiments using a variety of microwave power regimes while simultaneously recording the light intensity of any plasma generated within the carbon bed, together with its temperature. Evaluation using two different granular activated carbons and ethyl acetate, introduced as a vapor into the fluidizing air stream at a concentration of 1 ppm, yielded results which indicated that significant destruction of ethyl acetate, as monitored using a mass spectrometer, was achieved only with the carbon granules showing high plasma activity under pulsed microwave conditions. The system is therefore suitable for comparison of the relative microwave activities of various activated carbon granules and their performance in microwave remediation and regeneration.

  4. VEGF-induced angiogenesis following localized delivery via injectable, low viscosity poly(trimethylene carbonate).

    Science.gov (United States)

    Amsden, Brian G; Timbart, Laurianne; Marecak, Dale; Chapanian, Rafi; Tse, M Yat; Pang, Stephen C

    2010-07-14

    The purpose of this study was to examine the potential of low molecular weight poly(trimethylene carbonate) for localized vascular endothelial growth factor (VEGF) delivery. Poly(trimethylene carbonate) of various molecular weights was prepared by ring-opening polymerization initiated by 1-octanol. The resultant polymers were liquid at room temperature with low glass transition temperatures and viscosities at 37 degrees C that permitted their injection through an 18 (1/2) G 1.5'' needle. Particles consisting of VEGF co-lyophilized with trehalose were mixed into the polymers and the rate of release of VEGF was assessed in vitro. With a 1% particle loading, VEGF was released from the polymer at a rate of 20 ng/day over a period of 3 weeks. This release behavior was independent of the molecular weight of polymer used. Increasing the VEGF content in the lyophilized particles did not increase the VEGF release rate, an effect attributed to the solubility limit of VEGF in the solution formed upon dissolution of the particles. The VEGF released retained its bioactivity at greater than 95% of that of as-lyophilized VEGF, as assessed using a human aortic endothelial cell proliferation assay. This high bioactivity was supported by in vivo release experiments, wherein VEGF containing polymer implants induced the generation of significantly greater numbers of blood vessels towards the polymer implant than controls. The blood vessels did not remain stable and were reduced in number by three weeks, due to the unsustained and low concentration of VEGF released. This formulation approach, of using a low viscosity polymer delivery vehicle, is potentially useful for localized delivery of acid-sensitive proteins, such as VEGF. PMID:20381557

  5. Protection of carbon monoxide intraperitoneal administration from rat intestine injury induced by lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    LIU Shao-hua; MA Ke; XU Bing; XU Xin-rong

    2010-01-01

    Background Treatment with inhaled carbon monoxide (CO) has been shown to ameliorate intestinal injury in experimental animals induced by lipopolysaccharide (LPS) or ischemia-reperfusion. We hypothesized that CO intraperitoneal administration (i.p.) might provide similar protection to inhaled gas. This study aimed to investigate the effects of continuous 2 L/min of 250 ppm CO i.p. on rat intestine injury induced by LPS and to try to develop a more practical means of delivering the gas.Methods A total of 72 male Sprague-Dawley rats were randomly assigned to 4 groups: control group, CO i.p. group, LPS group and LPS+CO i.p. group. One hour after intravenously received 5 mg/kg LPS, the rats in LPS group and LPS+CO i.p. group were exposed to room air and 2 L/min of 250 ppm CO i.p., respectively, and the rats of control group and CO i.p. group intravenously received an equal volume of 0.9% NaClI and 1 hour later, were exposed to room air and 2 L/min of 250 ppm CO i.p., respectively. One, 3 and 6 hour of each group after treated with room air or CO i.p., the animals (n=6 for each time point) were sacrificed and intestinal tissues were collected for determinating the levels of platelet activator factor (PAF) and intercellular adhesion molecule-1 (ICAM-1) with enzyme-lined immunosorbent assays. The maleic dialdehyde (MDA) content and the myeloperoxidase (MPO) activity were determined with a chemical method. The phosphorylated p38 mitogen activated protein kinase (MAPK) expression was assayed with Western blotting and the cell apoptotic rate with flow cytometery. The arterial oxygenation was measured by blood gas analysis, and the pathology determined by light microscope.Results After treatment with 2 L/min of 250 ppm CO i.p., the increase of PAF, ICAM-1, MDA, MPO, and cell apoptotic rate induced by LPS was markedly reduced (P<0.05 or 0.01), and accompanied by ameliorating intestine injury. Western blotting showed that these effects of CO i.p. were mediated by p38 MAPK

  6. Electron irradiation-induced change of structure and damage mechanisms in multi-walled carbon nanotubes

    Science.gov (United States)

    Yang, Jian-Qun; Li, Xing-Ji; Liu, Chao-Ming; Ma, Guo-Liang; Gao, Feng

    2015-11-01

    Owing to their unique structure and excellent electrical property, carbon nanotubes (CNTs) as an ideal candidate for making future electronic components have great application potentiality. In order to meet the requirements for space application in electronic components, it is necessary to study structural changes and damage mechanisms of multi-walled carbon nanotubes (MWCNTs), caused by the irradiations of 70 and 110 keV electrons. In the paper, the changes of structure and damage mechanisms in the irradiated MWCNTs, induced by the irradiations of 70 and 110 keV electrons, are investigated. The changes in surface morphology and structure of the irradiated MWCNT film are characterized using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, x-ray diffraction analysis (XRD), and electron paramagnetic resonance (EPR) spectroscopy. It is found that the MWCNTs show different behaviors in structural changes after 70 and 110 keV electron irradiation due to different damage mechanisms. SEM results reveal that the irradiation of 70 keV electrons does not change surface morphology of the MWCNT film, while the irradiation of 110 keV electrons with a high fluence of 5 × 1015 cm-2 leads to evident morphological changes, such as the formation of a rough surface, the entanglement of nanotubes and the shrinkage of nanotubes. Based on Raman spectroscopy, XPS, and XRD analyses, it is confirmed that the irradiation of 70 keV electrons increases the interlayer spacing of the MWCNTs and disorders their structure through electronic excitations and ionization effects, while the irradiation of 110 keV electrons obviously reduces the interlayer spacing of the MWCNTs and improves their graphitic order through knock-on atom displacements. The improvement of the irradiated MWCNTs by 110 keV electrons is attributed to the restructuring of defect sites induced by knock-on atom displacements. EPR spectroscopic analyses reveal that the MWCNTs exposed

  7. Electron irradiation-induced change of structure and damage mechanisms in multi-walled carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    杨剑群; 李兴冀; 刘超铭; 马国亮; 高峰

    2015-01-01

    Owing to their unique structure and excellent electrical property, carbon nanotubes (CNTs) as an ideal candidate for making future electronic components have great application potentiality. In order to meet the requirements for space appli-cation in electronic components, it is necessary to study structural changes and damage mechanisms of multi-walled carbon nanotubes (MWCNTs), caused by the irradiations of 70 and 110 keV electrons. In the paper, the changes of structure and damage mechanisms in the irradiated MWCNTs, induced by the irradiations of 70 and 110 keV electrons, are investigated. The changes in surface morphology and structure of the irradiated MWCNT film are characterized using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, x-ray diffraction analysis (XRD), and electron paramagnetic resonance (EPR) spectroscopy. It is found that the MWCNTs show different behaviors in structural changes after 70 and 110 keV electron irradiation due to different damage mechanisms. SEM results reveal that the irra-diation of 70 keV electrons does not change surface morphology of the MWCNT film, while the irradiation of 110 keV electrons with a high fluence of 5 × 1015 cm−2 leads to evident morphological changes, such as the formation of a rough surface, the entanglement of nanotubes and the shrinkage of nanotubes. Based on Raman spectroscopy, XPS, and XRD analyses, it is confirmed that the irradiation of 70 keV electrons increases the interlayer spacing of the MWCNTs and disorders their structure through electronic excitations and ionization effects, while the irradiation of 110 keV electrons obviously reduces the interlayer spacing of the MWCNTs and improves their graphitic order through knock-on atom dis-placements. The improvement of the irradiated MWCNTs by 110 keV electrons is attributed to the restructuring of defect sites induced by knock-on atom displacements. EPR spectroscopic analyses reveal that the MWCNTs

  8. Investigation of a cell design for electrowinning zirconium metal from zirconium tetrachloride

    International Nuclear Information System (INIS)

    A cell concept adaptable to large-scale electrowinning of Zr metal from zirconium tetrachloride was investigated. Tests were made in twin cells, each 12 in. in dia x 33 in. long. Electrowinning was performed in one chamber from which the electrolyte was transferred after electrolysis to the other chamber where it was renewed by the introduction of ZrCl4 by direct sublimation. The formation of a salt plug in the connecting pipe provided a seal between the chambers. Optimum electrolyte composition, with respect to quality of the metal product (91% meeting ASTM standards except for the O content) and current-carrying capability (approximately 350 A) was determined to be 16.7 wt% NaF--83.3 wt% NaCl mixture plus ZrCl4 equal to approximately 3 wt% Zr. A twin-cell design incorporating the unit operations covered by this investigation is proposed

  9. Influence of viscosity of the medium on the disposition of carbon nanotubes anisotropic structures formation induced by electric field

    International Nuclear Information System (INIS)

    To obtain carbon nanotubes (CNT)-polymer composites with anisotropic physical properties an electric field application can be used. This investigation considers factors of CNT anisotropic distribution formation induced by electric field and consideration is supported with experimental results where some factors were varied. In the article an influence of magnitude and type of electric field and time of processing by electric field on CNT anisotropic structures formation in polymer mediums of different viscosities (oil, epoxy resins) is investigated. The aim of this work was to examine the CNT structuration process induced by electric field in viscous mediums and to find out the most optimal conditions of preparation of polymer/carbon composite materials (CM) with specified distribution of carbon filler induced by electric field. Scoping on polymer/carbon CM structuration was conducted by optical microscopy method. It was found that the main factors during CNT network formation are the type and viscosity of polymer binder and applied electric field parameters. It was observed that for high viscous polymer CNT network formation is unfeasible even at high applied electric field strength. But also for low viscous medium at relatively low electric field strength the CNT network formation is complicated too. And it was seen from optical observation that a type of the polymer variation causes different response of network form under the same experimental conditions. These distinctions are considered in the article

  10. Carbon Heavy-ion Radiation Induced Biological effects on Oryza sativa L.

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Gong, Ning; Meng, Qingmei; Liu, Jiawei; Wang, Ting

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pplant. Keywords: Heavy-ion radiation; Low dose; Stimulation effect; Inhibition effect; Rice.

  11. Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice

    Energy Technology Data Exchange (ETDEWEB)

    Nabeshima, T.; Katoh, A.; Ishimaru, H.; Yoneda, Y.; Ogita, K.; Murase, K.; Ohtsuka, H.; Inari, K.; Fukuta, T.; Kameyama, T. (Meijo Univ., Nagoya (Japan))

    1991-01-01

    We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, (3H)glutamate and (3H)glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of (3H)quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus.

  12. Synergistic neurotoxicity of carbon tetrachloride/carbon disulfide (80/20 fumigants) and other pesticides in grain storage workers.

    Science.gov (United States)

    Peters, H A; Levine, R L; Matthews, C G; Sauter, S; Chapman, L

    1986-01-01

    Neurophysiologic, neurobehavioral, and neuropsychologic profiles in 17 grain storage workers, 1 grain inspector, and 4 malting laboratory workers are described. The effects of CS2 toxicity as seen in viscose rayon workers as well as in experimental animals is remarkably similar to the clinical profile of our grain storage workers. CS2 use explains the dysfunction of peripheral axons, auditory nerve, the optic nerve, and the extrapyramidal system, as well as altered behavior and cognition changes. The signs and symptoms in these workers seem to be dose-related and we note that workers separated out from the areas where fumigation took place reported improvement not seen by fellow workers who continued the fumigant treatment routine. Likewise, malting laboratory workers exposed only to the grain dust from 3 to 7 years showed only minimal symptoms. Though a number of mechanism have been suggested for the alteration of neuropsychological function, the chelating ability of DDC derived from CS2 and its ability to markedly increase copper and zinc within the central nervous system suggests a mechanism of toxicity analogous to copper intoxication as in Wilson's Disease and may explain the production of extrapyramidal symptoms in these patients. Chelation of copper might prove therapeutic in CS2 poisoning. It is obvious that both basic and clinical research will be necessary to sort out the questions raised. We applaud the EPA's decision to ban the use of 80/20 fumigants and also methyl bromide, and trust that similar toxic substances be carefully studied before their selection for replacing these previous toxic agents. We further decry the technique of re-introducing grain dust into the food chain rather than destroying it, since the dust contains very high residues of fumigant material. We speculate on the possible role of CS2 and other pesticides in the food chain and the incidence of Parkinsonian symptoms in these patients and the general public.

  13. Clay improved dispersion of carbon nanotubes in different solvents

    International Nuclear Information System (INIS)

    Hybrid nano fillers composed of different ratios of carbon nanotubes (CNTs) and sodium montmorillonite (MMT) were prepared by physically pulverizing both materials in powder form. Their dispersion behavior was investigated in different solvents (water, toluene and carbon tetrachloride). UV-vis spectroscopy showed that the absorbance at 550 nm for the CNTs becomes more intense with the increasing amount of added MMT, when water is used as a solvent, implying their improved dispersion. This is not so evident for toluene and carbon tetrachloride. TGA analyses showed that the thermal stability of the hybrid nano fillers increases with the increase of the MMT content. Raman spectroscopy confirmed the mutual interaction between CNTs and MMT, demonstrated by shift of D and G band with addition of MMT in the nano filler.(Author)

  14. Enhanced electro-oxidation resistance of carbon electrodes induced by phosphorus surface groups

    OpenAIRE

    Berenguer Betrián, Raúl; Ruiz Rosas, Ramiro; Gallardo, Aurora; Cazorla Amorós, Diego; Morallón Núñez, Emilia; Nishihara, Hirotomo; Kyotani, Takashi; Rodríguez-Mirasol, José; Cordero, Tomás

    2015-01-01

    The electro-oxidation of carbon materials enormously degrades their performance and limits their wider utilization in multiple electrochemical applications. In this work, the positive influence of phosphorus functionalities on the overall electrochemical stability of carbon materials has been demonstrated under different conditions. We show that the extent and selectivity of electroxidation in P-containing carbons are completely different to those observed in conventional carbons without P. T...

  15. Laser-induced forward transfer of carbon nanowalls for soft electrodes fabrication

    Science.gov (United States)

    Constantinescu, Catalin; Vizireanu, Sorin; Ion, Valentin; Aldica, Gheorghe; Stoica, Silviu Daniel; Lazea-Stoyanova, Andrada; Alloncle, Anne-Patricia; Delaporte, Philippe; Dinescu, Gheorghe

    2016-06-01

    Carbon nanowalls (CNW) are two-dimensional interconnected graphitic nanostructures that have a few μm in length and height, reaching typical thicknesses of a few tens of nm. We present results on such layers synthesized in a low pressure argon plasma jet, injected with acetylene and hydrogen, on transparent substrates (quartz) heated at 600 °C, without catalyst. Thermogravimetric analysis reveals that the CNW are stable up to 420 °C in air, and Raman spectroscopy investigations highlight their graphene-like structure. Finally, using a pulsed Nd:YAG laser device (355 nm, 50 ps), we show that 2D-arrays of CNW (pixels and lines) can be printed by laser-induced forward transfer (LIFT), preserving their architecture and structure. Electrical measurements on 1 μm thick CNW demonstrate typical values in the range of 357.5-358.4 Ω for the samples grown on Au/Cr electrodes, and in the range of 450.1-474.7 Ω for the LIFT printed lines (under positive, negative, and neutral polarization; 1 kHz-5 MHz frequency range; 500 mV and 1 V, respectively). Their morphology is highlighted by means of optical and electronic microscopy. Such structures have potential applications as soft conductive lines, in sensor development and/or embedding purposes.

  16. Multiwalled Carbon Nanotube-TiO2 Nanocomposite for Visible-Light-Induced Photocatalytic Hydrogen Evolution

    Directory of Open Access Journals (Sweden)

    Ke Dai

    2014-01-01

    Full Text Available Multiwalled carbon nanotube- (MWCNT- TiO2 nanocomposite was synthesized via hydrothermal process and characterized by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, field emission scanning electron microscope, thermogravimetry analysis, and N2 adsorption-desorption isotherms. Appropriate pretreatment on MWCNTs could generate oxygen-containing groups, which is beneficial for forming intimate contact between MWCNTs and TiO2 and leads to a higher thermal stability of MWCNT-TiO2 nanocomposite. Modification with MWCNTs can extend the visible-light absorption of TiO2. 5 wt% MWCNT-TiO2 derived from hydrothermal treatment at 140°C exhibiting the highest hydrogen generation rate of 15.1 μmol·h−1 under visible-light irradiation and a wide photoresponse range from 350 to 475 nm with moderate quantum efficiency (4.4% at 420 nm and 3.7% at 475 nm. The above experimental results indicate that the MWCNT-TiO2 nanocomposite is a promising photocatalyst with good stability and visible-light-induced photoactivity.

  17. Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions

    Science.gov (United States)

    Mejía, C.; Bender, M.; Severin, D.; Trautmann, C.; Boduch, Ph.; Bordalo, V.; Domaracka, A.; Lv, X. Y.; Martinez, R.; Rothard, H.

    2015-12-01

    Solid carbon dioxide (CO2) is found in several bodies of the solar system, the interstellar medium (ISM) and young stellar objects, where it is exposed to cosmic and stellar wind radiation. Here, the chemical and physical modifications induced by heavy ion irradiation of pure solid CO2 at low temperature (T = 15-30 K) are analyzed. The experiments were performed with Ti (550 MeV) and Xe (630 MeV) ions at the UNILAC of GSI/Darmstadt and with Ni ions (46 and 52 MeV) at IRRSUD of GANIL/Caen. The evolution of the thin CO2 ice films (deposited on a CsI window) was monitored by mid-infrared absorption spectroscopy (FTIR). The dissociation rate of CO2, determined from the fluence dependence of the IR absorption peak intensity, is found to be proportional to the electronic stopping power Se. We also confirm that the sputtering yield shows a quadric increase with electronic stopping power. Furthermore, the production rates of daughter molecules such as CO, CO3 and O3 were found to be linear in Se.

  18. Light-induced vibration characteristics of free-standing carbon nanotube films fabricated by vacuum filtration

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junying; Zhu, Yong, E-mail: yongzhu@cqu.edu.cn; Wang, Ning; Zhang, Jie [The Key Laboratory of Optoelectronic Technology and System, Education Ministry of China, Chongqing University, Chongqing, 400044 (China); Wang, Xin [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, 610054 (China)

    2014-07-14

    In this paper, we fabricated carbon nanotube (CNT) films with different thickness by vacuum filtration method, and the films were separated from Mixed Cellulose Ester membranes with burn-off process. The thickness of CNT films with different concentrations of CNTs 50 mg, 100 mg, 150 mg, and 200 mg are 10.36 μm, 20.90 μm, 30.19 μm, and 39.98 μm respectively. The CNT bundles are homogeneously distributed and entangled with each other, and still maintain 2D continuous network structures after burn-off process. The optical absorptivity of the films is between 84% and 99% at wavelengths ranging from 400 nm to 2500 nm. Vibration characteristics were measured with the Fabry-Perot (F-P) interferometer vibration measurement system. CNT films vibrate only under the xenon light irradiating perpendicularly to the surface. Vibration recorded by Fabry-Perot interferometer is considered to be caused by the time-dependent thermal moment, which is due to the temperature differences of two sides of CNT films. The vibration frequency spectrums between 0.1 ∼ 0.5 Hz were obtained by the Fast Fourier Transform spectra from time domain to frequency domain, and showed a linear relationship with films thickness, which is in accordance with theoretical model of thermal induced vibration.

  19. Adsorption of the reactive azo dyes onto NH4Cl-induced activated carbon

    Directory of Open Access Journals (Sweden)

    Sakine Shekoohiyan

    2016-03-01

    Full Text Available Background: The efficacy of NH4Cl-induced activated carbon (NAC was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10, adsorbent dose (0.1 to 1.2 g/L, dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

  20. Carbon Disulphide Induced Sensitivity Changes of Rat Anococcygeus Muscle to Noradrenaline(NA)

    Institute of Scientific and Technical Information of China (English)

    D.N.GANDHI; H.VENKATAKRISHNA-BHATT

    1993-01-01

    The sensitivity of rat anococcygeus muscle to noradrenaline(NA)was reduced following carbon disulphide(CS2)pretreatment.Preparations incubated in excess Ca++(4.2mmol·L-1)or Zero Ca++(0.0mmol·L-1)media showed decrease in sensitivity to NA.Reserpinization failed to induce supersensitivity to NA in any Mg++ concentration in the media.Reserpinized tissue in Mg++ free media with EDTA showed increased sensitivity while decreased sensitivity and maximum response to NA in Mg++(1.2mmol·L-1)and excess Mg++(3.6mmol·L-1)concentration of the medium.In the presence of EDTA,the inhibition obsevved with CS2 in excess Mg++(3.6mmol·L-1)medium was comparatively much less in both non-reserpinized and reserpinized preparations.In normal Ca++ and its deficient medium decrease in sensitivity to CS2 and the relevant maximum response to NA were observed.In excess Ca++,the CS2 effect depressed corresponding to its maximal response to NA.Thus CS2 may be inhibiting responss to NA by interfering with Ca++ utilization.

  1. Immunotoxicity and allergic potential induced by topical application of dimethyl carbonate (DMC) in a murine model.

    Science.gov (United States)

    Anderson, Stacey E; Franko, Jennifer; Anderson, Katie L; Munson, Albert E; Lukomska, Ewa; Meade, B Jean

    2013-01-01

    Dimethyl carbonate (DMC) is an industrial chemical, used as a paint and adhesive solvent, with the potential for significant increases in production. Using select immune function assays, the purpose of these studies was to evaluate the immunotoxicity of DMC following dermal exposure using a murine model. Following a 28-day exposure, DMC produced a significant decrease in thymus weight at concentrations of 75% and greater. No effects on body weight, hematological parameters (erythrocytes, leukocytes, and their differentials), or immune cell phenotyping (B-cells, T-cells, and T-cell sub-sets) were identified. The IgM antibody response to sheep red blood cell (SRBC) was significantly reduced in the spleen but not the serum. DMC was not identified to be an irritant and evaluation of the sensitization potential, conducted using the local lymph node assay (LLNA) at concentrations ranging from 50-100%, did not identify increases in lymphocyte proliferation. These results demonstrate that dermal exposure to DMC induces immune suppression in a murine model and raise concern about potential human exposure and the need for occupational exposure regulations. PMID:22953780

  2. Bystander effects induced by medium from carbon-ion irradiated human cancer cells

    Institute of Scientific and Technical Information of China (English)

    WANG Ju-Fang; LI Wen-Jian; ZHOU Guang-Ming; DANG Bing-Rong; MA Qiu-Feng; FENG Yan

    2005-01-01

    The bystander effects induced by medium from human hepatoma SMMC-7721 and adenocarcinoma F56 cells irradiated with carbon ions were investigated. It was found that the survival fraction (SF) of the irradiated cells decreased exponentially along with the increased dose. SMMC-7721 cells were more radiosensitive than F56 cells.The plating efficiency (PE) of the non-irradiated cells treated with irradiated conditioned medium (ICM) was obviously lower than the PE of control cells for SMMC-7721 cells but not for F56 cells. Moreover, the reduced PE and SF by ICM treatment were more significant for 1Gy irradiation than for 6Gy irradiation on SMMC-7721 cells. These results suggest that the irradiated cells can secrete factor(s) into medium that is cytotoxic to bystander non-irradiated cells. The bystander effects are dependent on cell genotype presented at the time of irradiation and radiation dose.This makes impact on the precise estimation of the effects of radiation and tumor radiotherapy.

  3. Lattice mismatch induced curved configurations of hybrid boron nitride-carbon nanotubes

    Science.gov (United States)

    Zhang, Jin

    2016-10-01

    A unique curved configuration is observed in freestanding hybrid boron nitride-carbon nanotubes (BN-CNTs) based on molecular dynamics simulations, which, in previous studies, was tacitly assumed as a straight configuration. The physical fundamentals of this phenomenon are explored by using the continuum mechanics theory, where the curved configuration of BN-CNTs is found to be induced by the bending effect due to the lattice mismatch between the C domain and the BN domain. In addition, our results show that the curvature of the curved BN-CNTs is determined by their radius and composition. The curvature of BN-CNTs decreases with growing radius of BN-CNTs and becomes ignorable when their radius is relatively large. A non-monotonic relationship is detected between the curvature and the composition of BN-CNTs. Specifically, the curvature of BN-CNTs increases with growing BN concentration when the molar fraction of BN atoms is smaller than a critical value 0.52, but decreases with growing BN concentration when the molar fraction of BN atoms is larger than this critical value.

  4. Effect of Mg/Ca ratios on microbially induced carbonate precipitation

    Science.gov (United States)

    Balci, Nurgul; Demirel, Cansu; Seref Sonmez, M.; Kurt, M. Ali

    2016-04-01

    Influence of Mg/Ca ratios on microbially induced carbonate mineralogy were investigated by series of experiments carried out under various environmental conditions (Mg/Ca ratio, temperature and salinity). Halophilic bacterial cultures used for biomineralization experiments were isolated from hypersaline Lake Acıgöl (Denizli, SW Turkey), displaying extreme water chemistry with an average pH around 8.6 (Balci eta l.,2015). Enriched bacterial culture used in the experiments consisted of Halomonas saccharevitans strain AJ275, Halomonas alimentaria strain L7B; Idiomarina sp. TBZ29, 98% Idiomarina seosensis strain CL-SP19. Biomineralization experiments were set up using above enriched culture with Mg/Ca ratios of 0.05, 1, 4 and 15 and salinity of 8% and 15% experiments at 30oC and 10oC. Additionally, long-term biomineralization experiments were set up to last for a year, for Mg/Ca=4 and Mg/Ca=15 experiments at 30oC. For each experimental condition abiotic experiments were also conducted. Solution chemistry throughout incubation was monitored for Na, K, Mg, Ca, bicarbonate, carbonate, ammonium and phosphate for a month. At the end of the experiments, precipitates were collected and morphology and mineralogy of the biominerals were investigated and results were evaluated using the software DIFFRAC.SUITE EVA. Overall the preliminary results showed chemical precipitation of calcite, halite, hydromagnesite and sylvite. Results obtained from biological experiments indicate that, low Mg/Ca ratios (0.05 and 1) favor chlorapatite precipitation, whereas higher Mg/Ca ratios favor struvite precipitation. Biomineralization of dolomite, huntite and magnesite is favorable at high Mg/Ca ratios (4 and 15), in the presence of halophilic bacteria. Moreover, results indicate that supersaturation with respect to Mg (Mg/Ca=15) combined with NaCl (15%) inhibits biomineralization and forms chemical precipitates. 15% salinity is shown to favor chemical precipitation of mineral phases more than

  5. Chemical bonding modifications of tetrahedral amorphous carbon and nitrogenated tetrahedral amorphous carbon films induced by rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    McCann, R. [NIBEC, School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, Co. Antrim, BT37 OQB, N. Ireland (United Kingdom); Roy, S.S. [NIBEC, School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, Co. Antrim, BT37 OQB, N. Ireland (United Kingdom)]. E-mail: s.sinha-roy@ulster.ac.uk; Papakonstantinou, P. [NIBEC, School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, Co. Antrim, BT37 OQB, N. Ireland (United Kingdom); Bain, M.F. [Queens University of Belfast, School of Elect and Elect Engineering, Belfast, Antrim, N. Ireland (United Kingdom); Gamble, H.S. [Queens University of Belfast, School of Elect and Elect Engineering, Belfast, Antrim, N. Ireland (United Kingdom); McLaughlin, J.A. [NIBEC, School of Electrical and Mechanical Engineering, University of Ulster at Jordanstown, Newtownabbey, Co. Antrim, BT37 OQB, N. Ireland (United Kingdom)

    2005-06-22

    Tetrahedral amorphous carbon (ta-C) and nitrogenated tetrahedral amorphous carbon films (ta-CN {sub x}), deposited by double bend off plane Filtered Vacuum Cathodic Arc were annealed up to 1000 deg. C in flowing argon for 2 min. Modifications on the chemical bonding structure of the rapidly annealed films, as a function of temperature, were investigated by NEXAFS, X-ray photoelectron and Raman spectroscopies. The interpretation of these spectra is discussed. The results demonstrate that the structure of undoped ta-C films prepared at