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Sample records for carbon tetrachloride induced

  1. Role of trimetazidine in carbon tetrachloride induced liver damage in rats

    OpenAIRE

    Vijay H. Mate; Vijaya A. Pandit; Dileep B. Wani; Priti P. Dhande

    2014-01-01

    Background: Hepatotoxicity by chemicals and drugs is a common clinical problem. Presently very few drugs are showing effectiveness in prevention and treatment of hepatic damage. So in this study, we evaluated the role of trimetazidine in carbon tetrachloride (CCl4) induced liver damage in rats. Objective of current study is to evaluate effects of prophylactic trimetazidine against carbon tetrachloride induced liver damage in rats. Methods: Liver damage was induced in 30 albino rats by CCl4...

  2. 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.

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

  5. Hepatoprotective effects of Rubus coreanus miquel concentrates on liver injuries induced by carbon tetrachloride in rats

    OpenAIRE

    Chae, Hyun-Jung; Yim, Jung-Eun; Kim, Kyung-Ah; Chyun, Jong-Hee

    2014-01-01

    As well-being foods pursuing healthy life are becoming popular, interest in Rubus coreanus Miquel (RCM) fruit, a type of Korean blackberry, is increasing due to its medicinal actions including protecting the liver, brightening the eyes, and alleviating diabetes. This study was carried out to evaluate the hepatoprotective effects of RCM concentrates on liver injuries induced by carbon tetrachloride (CCl4) in rats. RCM, produced in June ~ July 2008 at Chunbook, Gochang (South Korea), was finely...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  9. 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

  10. Ginseng extract and ginsenoside Rb1 attenuate carbon tetrachloride-induced liver fibrosis in rats

    OpenAIRE

    Hou, Ya-Ling; Tsai, Ya-Hui; Lin, Yun-Ho; Chao, Jane C-J

    2014-01-01

    Background Ginsenosides, the major bioactive compounds in ginseng root, have been found to have antioxidant, immunomodulatory and anti-inflammatory activities. This study investigated the effects of ginsenosides on carbon tetrachloride (CCl4)-induced hepatitis and liver fibrosis in rats. Methods Male Sprague–Dawley rats were randomly divided into four groups: control, CCl4, CCl4 + 0.5 g/kg Panax ginseng extract and CCl4 + 0.05 g/kg ginsenoside Rb1 groups. The treated groups were orally given ...

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

    Science.gov (United States)

    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.

    Science.gov (United States)

    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

    Directory of Open Access Journals (Sweden)

    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. Carbon tetrachloride under extreme conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pravica, Michael, E-mail: pravica@physics.unlv.edu; Sneed, Daniel; Wang, Yonggang; Smith, Quinlan [High Pressure Science and Engineering Center (HiPSEC) and Department of Physics, University of Nevada Las Vegas (UNLV), Las Vegas, Nevada 89154-4002 (United States); Subrahmanyam, Garimella [Canadian Light Source, Department of Physics, University of Saskatchewan, Saskatoon, Saskatchewan S7N 2V3 (Canada)

    2014-05-21

    We report on three experiments on carbon tetrachloride subjected to extreme conditions. In the first experiment, Raman spectra of CCl{sub 4} were acquired up to 28 GPa. Evidence was observed for at least two new phases of CCl{sub 4} above 14 GPa (phase VI) and above 22 GPa (phase VII). Decompression of the sample showed no evidence of pressure-induced decomposition. In the second experiment, a synchrotron x-ray diffraction study was performed up to 30 GPa verifying phase V and potential phases above 14 (VI) and 22 GPa (VII), respectively. In the third study, we examined irradiated CCl{sub 4} using synchrotron infrared spectroscopy to reduce fluorescent contamination. Some sort of carbon allotrope appears as a byproduct suggesting the following reaction with hard x-rays: CCl{sub 4}+ hν → C + 2Cl{sub 2}.

  19. 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.

  20. Toxicological and biochemical studies on Schinus terebinthifolius concerning its curative and hepatoprotective effects against carbon tetrachloride-induced liver injury

    OpenAIRE

    Abdou, Rania H.; Sherif Y Saleh; Khalil, Waleed F.

    2015-01-01

    Background: Recently, many efforts have been made to discover new products of natural origin which can limit the xenobiotic-induced hepatic injury. Carbon tetrachloride (CCl 4 ) is a highly toxic chemical that is widely used to study hepatotoxicity in animal models. Objective: The present study was conducted to investigate the curative and protective effects of Schinus terbenthifolius ethanolic extract against CCl 4 -induced acute hepatotoxicity in rats. Materials and Methods: S. terbenthifol...

  1. 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.

  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. Protective effect of potato peel extract against carbon tetrachloride-induced liver injury in rats.

    Science.gov (United States)

    Singh, Nandita; Kamath, Vasudeva; Narasimhamurthy, K; Rajini, P S

    2008-09-01

    Our earlier studies have shown that extracts derived from potato peel (PPE) are rich in polyphenols and possess strong antioxidant activity both in vitro and in vivo. The objective of the present study was to investigate its potential to offer protection against acute liver injury in rats. Rats pretreated with PPE (oral, 100mg/kgb.w./day for 7 days) were administered a single oral dose carbon tetrachloride (CCl(4), 3ml/kg b.w., 1:1 in groundnut oil) and sacrificed 8h of post-treatment. Hepatic damage was assessed by employing biochemical parameters (transaminase enzyme levels in plasma and liver [AST-aspartate transaminase; ALT-alanine transaminase, LDH-lactate dehydrogenase]). Further, markers of hepatic oxidative damage were measured in terms of malondialdehyde (MDA), enzymic antioxidants (CAT, SOT, GST, GPX) and GSH (reduced glutathione) levels. In addition, the CCl(4)-induced pathological changes in liver were evaluated by histopathological studies. Our results demonstrated that pretreatment of rats with PPE significantly prevented the increased activities of AST and ALT in serum, prevented the elevation of hepatic MDA formation as well as protected the liver from GSH depletion. PPE pretreatment also restored CCl(4)-induced altered antioxidant enzyme activities to control levels. The protective effect of PPE was further evident through the decreased histological alterations in liver. Our findings provide evidences to demonstrate that PPE pretreatment significantly offsets CCl(4)-induced liver injury in rats, which may be attributable to its strong antioxidant propensity. PMID:21791371

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

    Directory of Open Access Journals (Sweden)

    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. 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.

  7. 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.

  8. 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

  9. 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...

  10. 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% ...

  11. 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 ...

  12. 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) (...

  13. 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

  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. Carbon tetrachloride-mediated lipid peroxidation induces early mitochondrial alterations in mouse liver.

    Science.gov (United States)

    Knockaert, Laetitia; Berson, Alain; Ribault, Catherine; Prost, Pierre-Emmanuel; Fautrel, Alain; Pajaud, Julie; Lepage, Sylvie; Lucas-Clerc, Catherine; Bégué, Jean-Marc; Fromenty, Bernard; Robin, Marie-Anne

    2012-03-01

    Although carbon tetrachloride (CCl(4))-induced acute and chronic hepatotoxicity have been extensively studied, little is known about the very early in vivo effects of this organic solvent on oxidative stress and mitochondrial function. In this study, mice were treated with CCl(4) (1.5 ml/kg ie 2.38 g/kg) and parameters related to liver damage, lipid peroxidation, stress/defense and mitochondria were studied 3 h later. Some CCl(4)-intoxicated mice were also pretreated with the cytochrome P450 2E1 inhibitor diethyldithiocarbamate or the antioxidants Trolox C and dehydroepiandrosterone. CCl(4) induced a moderate elevation of aminotransferases, swelling of centrilobular hepatocytes, lipid peroxidation, reduction of cytochrome P4502E1 mRNA levels and a massive increase in mRNA expression of heme oxygenase-1 and heat shock protein 70. Moreover, CCl(4) intoxication induced a severe decrease of mitochondrial respiratory chain complex IV activity, mitochondrial DNA depletion and damage as well as ultrastructural alterations. Whereas DDTC totally or partially prevented all these hepatic toxic events, both antioxidants protected only against liver lipid peroxidation and mitochondrial damage. Taken together, our results suggest that lipid peroxidation is primarily implicated in CCl(4)-induced early mitochondrial injury. However, lipid peroxidation-independent mechanisms seem to be involved in CCl(4)-induced early hepatocyte swelling and changes in expression of stress/defense-related genes. Antioxidant therapy may not be an efficient strategy to block early liver damage after CCl(4) intoxication. PMID:22157718

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

    Directory of Open Access Journals (Sweden)

    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. Ferulic acid protects against carbon tetrachloride-induced liver injury in mice

    International Nuclear Information System (INIS)

    Ferulic acid (FA), isolated from the root of Scrophularia buergeriana, is a phenolic compound possessing antioxidant, anticancer, and antiinflammatory activities. Here, we have investigated the hepatoprotective effect of FA against carbon tetrachloride (CCl4)-induced acute liver injury. Mice were treated intraperitoneally with vehicle or FA (20, 40, and 80 mg/kg) 1 h before and 2 h after CCl4 (20 μl/kg) injection. The serum activities of aminotransferases and the hepatic level of malondialdehyde were significantly higher after CCl4 treatment, while the concentration of reduced glutathione was lower. These changes were attenuated by FA. The serum level and mRNA expression of tumor necrosis factor-α significantly increased after CCl4 treatment, and FA attenuated these increases. The levels of inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expression after CCl4 treatment were significantly higher and FA reduced these increases. CCl4-treated mice showed increased nuclear translocation of nuclear factor-κB (NF-κB), and decreased levels of inhibitors of NF-κB in cytosol. Also, CCl4 significantly increased the level of phosphorylated JNK and p38 mitogen-activated protein (MAP) kinase, and nuclear translocation of activated c-Jun. FA significantly attenuated these changes. We also found that acute CCl4 challenge induced TLR4, TLR2, and TLR9 protein and mRNA expression, and FA significantly inhibited TLR4 expression. These results suggest that FA protects from CCl4-induced acute liver injury through reduction of oxidative damage and inflammatory signaling pathways.

  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. 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 ...

  20. 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...

  1. 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.

  2. 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.

  3. 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.

  4. Melatonin enhances mitophagy and mitochondrial biogenesis in rats with carbon tetrachloride-induced liver fibrosis.

    Science.gov (United States)

    Kang, Jung-Woo; Hong, Jeong-Min; Lee, Sun-Mee

    2016-05-01

    Liver fibrosis leads to liver cirrhosis and failure, and no effective treatment is currently available. Growing evidence supports a link between mitochondrial dysfunction and liver fibrogenesis and mitochondrial quality control-based therapy has emerged as a new therapeutic target. We investigated the protective mechanisms of melatonin against mitochondrial dysfunction-involved liver fibrosis, focusing on mitophagy and mitochondrial biogenesis. Rats were treated with carbon tetrachloride (CCl4 ) dissolved in olive oil (0.5 mL/kg, twice a week, i.p.) for 8 wk. Melatonin was administered orally at 2.5, 5, and 10 mg/kg once a day. Chronic CCl4 exposure induced collagen deposition, hepatocellular damage, and oxidative stress, and melatonin attenuated these increases. Increases in mRNA and protein expression levels of transforming growth factor β1 and α-smooth muscle actin in response to CCl4 were attenuated by melatonin. Melatonin attenuated hallmarks of mitochondrial dysfunction, such as mitochondrial swelling and glutamate dehydrogenase release. Chronic CCl4 exposure impaired mitophagy and mitochondrial biogenesis, and melatonin attenuated this impairment, as indicated by increases in mitochondrial DNA and in protein levels of PTEN-induced putative kinase 1 (PINK1); Parkin; peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α); nuclear respiratory factor 1 (NRF1); and transcription factor A, mitochondrial (TFAM). CCl4 -mediated decreases in mitochondrial fission- and fusion-related proteins, such as dynamin-related protein 1 (DRP1) and mitofusin 2, were also attenuated by melatonin. Moreover, melatonin induced AMP-activated protein kinase (AMPK) phosphorylation. These results suggest that melatonin protects against liver fibrosis via upregulation of mitophagy and mitochondrial biogenesis, and may be useful as an anti-fibrotic treatment. PMID:26882442

  5. Effect of Ribavirin Alone or Combined with Silymarin on Carbon Tetrachloride Induced Hepatic Damage in Rats

    Directory of Open Access Journals (Sweden)

    Omar M.E. Abdel Salam

    2007-01-01

    Full Text Available The effect of the antiviral agent ribavirin given alone or in combination with silymarin on the development of liver injury induced in rats with carbon tetrachloride (CCl4; 2.8 ml/kg followed by 1.4 ml/kg after one week was studied. Ribavirin at three dose levels (30, 60 or 90 mg/kg, silymarin (25 mg/kg or combination of ribavirin (60 mg/kg and silymarin (25 mg/kg was administered once daily orally for 14 days, starting at time of administration of CCl4. The administration of ribavirin decreased the elevations in serum alanine aminotransferase (ALT by 78.5, 82.1, 75.1%, aspartate aminotransferase (AST 47.5, 37.4, 38.8%, and alkaline phosphatase (ALP by 23.4, 16, 21.6%, respectively and also prevented the development of hepatic necrosis caused by CCl4. In comparison, the elevated serum ALT, AST and ALP levels decreased to 43.3%, 46%, and 37.5% of controls, respectively by silymarin. When silymarin was combined with ribavirin, the serum activities of AST and ALP were further decreased, indicating a benefi cial additive effect. Morphometric analysis indicated signifi cant reduction in the area of necrosis and fi brosis on ribavirin treatment and this was further reduced after the addition of silymarin. Metabolic pertuberations caused by CCl4 as refl ected in a decrease in intracellular protein content in hepatocytes were improved by ribavirin monotherapy and to higher extent by combined silymarin and ribavirin therapy. Proliferating cell nuclear antigen was reduced in nuclei of hepatocytes by ribavirin montherapy or the combination of ribavirin and silymarin compared with CCl4-control group. The study demonstrates that ribavirin treatment in the model of CCl4- induced liver injury results in less liver damage. Results also indicate that the combined application of ribavirin and silymarin is likely to be a useful additive in reducing liver injury.

  6. Effect of ribavirin alone or combined with silymarin on carbon tetrachloride induced hepatic damage in rats.

    Science.gov (United States)

    Abdel Salam, Omar M E; Sleem, Amany A; Omara, Enayat A; Hassan, Nabila S

    2007-01-01

    The effect of the antiviral agent ribavirin given alone or in combination with silymarin on the development of liver injury induced in rats with carbon tetrachloride (CCl(4); 2.8 ml/kg followed by 1.4 ml/kg after one week) was studied. Ribavirin at three dose levels (30, 60 or 90 mg/kg), silymarin (25 mg/kg) or combination of ribavirin (60 mg/kg) and silymarin (25 mg/kg) was administered once daily orally for 14 days, starting at time of administration of CCl(4). The administration of ribavirin decreased the elevations in serum alanine aminotransferase (ALT) by 78.5, 82.1, 75.1%, aspartate aminotransferase (AST) 47.5, 37.4, 38.8%, and alkaline phosphatase (ALP) by 23.4, 16, 21.6%, respectively and also pre-vented the development of hepatic necrosis caused by CCl(4). In comparison, the elevated serum ALT, AST and ALP levels decreased to 43.3%, 46%, and 37.5% of controls, respectively by silymarin. When silymarin was combined with ribavirin, the serum activities of AST and ALP were further decreased, indicating a beneficial additive effect. Morphometric analysis indicated significant reduction in the area of necrosis and fibrosis on ribavirin treatment and this was further reduced after the addition of silymarin. Metabolic pertuberations caused by CCl(4) as reflected in a decrease in intracellular protein content in hepatocytes were improved by ribavirin monotherapy and to higher extent by combined silymarin and ribavirin therapy. Proliferating cell nuclear antigen was reduced in nuclei of hepatocytes by ribavirin montherapy or the combination of ribavirin and silymarin compared with CCl(4)-control group. The study demonstrates that ribavirin treatment in the model of CCl(4)-induced liver injury results in less liver damage. Results also indicate that the combined application of ribavirin and sily-marin is likely to be a useful additive in reducing liver injury. PMID:21901059

  7. Chlordecone potentiates hepatic fibrosis in chronic liver injury induced by carbon tetrachloride in mice.

    Science.gov (United States)

    Tabet, Elise; Genet, Valentine; Tiaho, François; Lucas-Clerc, Catherine; Gelu-Simeon, Moana; Piquet-Pellorce, Claire; Samson, Michel

    2016-07-25

    Chronic liver damage due to viral or chemical agents leads to a repair process resulting in hepatic fibrosis. Fibrosis may lead to cirrhosis, which may progress to liver cancer or a loss of liver function, with an associated risk of liver failure and death. Chlordecone is a chlorinated pesticide used in the 1990s. It is not itself hepatotoxic, but its metabolism in the liver triggers hepatomegaly and potentiates hepatotoxic agents. Chlordecone is now banned, but it persists in soil and water, resulting in an ongoing public health problem in the Caribbean area. We assessed the probable impact of chlordecone on the progression of liver fibrosis in the population of contaminated areas, by developing a mouse model of chronic co-exposure to chlordecone and a hepatotoxic agent, carbon tetrachloride (CCl4). After repeated administrations of chlordecone and CCl4 by gavage over a 12-week period, we checked for liver damage in the exposed mice, by determining serum liver transaminase (AST, ALT) levels, histological examinations of the liver and measuring the expression of genes encoding extracellular matrix components. The co-exposure of mice to CCl4 and chlordecone resulted in significant increases in ALT and AST levels. Chlordecone also increased expression of the Col1A2, MMP-2, TIMP-1 and PAI-1 genes in CCl4-treated mice. Finally, we demonstrated, by quantifying areas of collagen deposition and alpha-SMA gene expression, that chlordecone potentiated the hepatic fibrosis induced by CCl4. In conclusion, our data suggest that chlordecone potentiates hepatic fibrosis in mice with CCl4-induced chronic liver injury. PMID:26853152

  8. 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

  9. 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

  10. 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.

  11. 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

  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. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

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

    Directory of Open Access Journals (Sweden)

    Feng Yibin

    2010-09-01

    Full Text Available 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 with 50% CCl4 in olive oil. Berberine was orally administered before or after CCl4 treatment in various groups. Twenty-four hours after CCl4 injection, serum alanine aminotransferase (ALT and aspartate aminotransferase (AST activities, serum and liver superoxide dismutase (SOD activities were measured. Histological changes of liver were examined with microscopy. Results Serum ALT and AST activities significantly decreased in a dose-dependent manner in both pre-treatment and post-treatment groups with berberine. Berberine increased the SOD activity in liver. Histological examination showed lowered liver damage in berberine-treated groups. Conclusion The present study demonstrates that berberine possesses hepatoprotective effects against CCl4-induced hepatotoxicity and that the effects are both preventive and curative. Berberine should have potential for developing a new drug to treat liver toxicity.

  1. Possible Protective Effect of Kombucha Tea Ferment on Carbon Tetrachloride Induced Liver Damage in Irradiated Rats

    International Nuclear Information System (INIS)

    This study has shown that administration of kombucha ferment tea (KT) to rats improved the damage caused in livers of animals treated with toxic chemicals such as carbon tetrachloride (CCL4) and/ or exposed to y-irradiation. This work was undertaken to evaluate the possible protective effects of treatment with KT ferment in rat liver after a long-term treatment with CCL4 alone and with subsequent y-irradiation. Hepatic pathological changes observed in the CCL4-treated rats included increased serum alanine transaminase (ALT) , aspartate transaminase (AST), alkaline phosphatase (ALP) and gamma glutamyl transferase (GGT) activities as well as concentration of bilirubin in addition to a decrease in the concentration of serum albumin and total antioxidant capacity (TAC). Consistent with these changes, the increase in oxidative stress markers expressed as malondialdehyde (MDA) concentration and depletion in glutathione (GSH) contents in liver was observed. 24 h after the last dose of KT administration in a group of animals treated with CCL4 and/ or radiation exposure cessation, the pathological changes were recovered. These results demonstrate that most of the pathological alterations in the liver in response to CCL4 and/ or radiation exposure intoxication are recoverable upon treatment with KT ferments

  2. Hepatoprotective effect of grape seed oil against carbon tetrachloride induced oxidative stress in liver of γ-irradiated rat.

    Science.gov (United States)

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

    2016-07-01

    Carbon tetrachloride (CCl4) and ionizing radiation are well known environmental pollutants that generate free radicals and induce oxidative stress. The liver is the primary and major target organ responsible for the metabolism of drugs, toxic chemicals and affected by irradiation. This study investigated the effect of grape seed oil (GSO) on acute liver injury induced by carbon tetrachloride (CCl4) in γ-irradiated rats (7Gy). CCl4-intoxicated rats exhibited an elevation of ALT, AST activities, IL-6 and TNF-α level in the serum. Further, the levels of MDA, NO, NF-κB and the gene expression of CYP2E1, iNOS and Caspase-3 were increased, and SOD, CAT, GSH-Px, GST activities and GSH content were decreased. Furthermore, silent information regulator protein 1 (SIRT1) gene expression was markedly down-regulated. Additionally, alterations of the trace elements; copper, manganese, zinc and DNA fragmentation was observed in the hepatic tissues of the intoxicated group. These effects were augmented in CCl4-intoxicated-γ-irradiated rats. However, the administration of GSO ameliorated these parameters. GSO exhibit protective effects on CCl4 induced acute liver injury in γ-irradiated rats that could be attributed to its potent antioxidant, anti-inflammatory and anti-apoptotic activities. The induction of the antioxidant enzymes activities, down-regulation of the CYP2E1, iNOS, Caspase-3 and NF-κB expression, up-regulation of the trace elements concentration levels and activation of SIRT1 gene expression are responsible for the improvement of the antioxidant and anti-inflammatory status in the hepatic tissues and could be claimed to be the hepatoprotective mechanism of GSO. PMID:27085796

  3. 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

  4. Roles of Oxidized Diacylglycerol for Carbon Tetrachloride-induced Liver Injury and Fibrosis in Mouse

    International Nuclear Information System (INIS)

    Since there is a report that an inhibitor of protein kinase C (PKC) effectively suppresses the development of hepatic fibrosis, it is suggested that the PKC signaling pathway plays an important role in the pathogenesis of hepatic fibrosis. We reported that oxidized diacylglycerol (DAG), which is an activator of PKC, had a remarkably stronger PKC-activating action than un-oxidized DAG. In the present study, we explored the roles of oxidized DAG in hepatic fibrogenesis using mice, the livers of which developed fibrosis by long-term administration of carbon tetrachloride (CCl4). Liver fibrosis models were created by 4- or 8-week repetitive subcutaneous injections of CCl4 to the backs of C57BL/6J mice. The amount of oxidized DAG was significantly increased in the CCl4-treated group. Moreover, it was found that PKCα, βI, βII and δ were activated. In the CCl4-treated group, phosphorylation of ERK and JNK, which are downstream signal transmitters in the PKC pathway, was increased. It was also found in this group that there was an increase in TIMP-1, which is a fibrogenesis-promoting factor whose expression is enhanced by activated JNK, and of TNF-α, an inflammatory cytokine. Analysis by quantitative real-time RT-PCR showed that expressions of αSMA, collagen I, TNF-α and IL-10 were remarkably increased in the 8-week CCl4-treated group. The above results strongly suggested that oxidized DAG, which is increased by augmented oxidative stress, activated PKCα, βI, βII and δ molecular species and that these molecular species in turn stimulated the phosphorylation of MAP kinases including ERK and JNK, resulting in enhancement of hepatic fibrogenesis

  5. 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.

  6. Sympathetic Nervous System Control of Carbon Tetrachloride-Induced Oxidative Stress in Liver through α-Adrenergic Signaling

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    Jung-Chun Lin

    2016-01-01

    Full Text Available In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS in modulating the hepatic response to oxidative stress. Our aim was to investigate the role of the SNS in healthy and oxidatively stressed liver parenchyma. Mice treated with 6-hydroxydopamine hydrobromide were used to realize chemical sympathectomy. Carbon tetrachloride (CCl4 injection was used to induce oxidative liver injury. Sympathectomized animals were protected from CCl4 induced hepatic lipid peroxidation-mediated cytotoxicity and genotoxicity as assessed by 4-hydroxy-2-nonenal levels, morphological features of cell damage, and DNA oxidative damage. Furthermore, sympathectomy modulated hepatic inflammatory response induced by CCl4-mediated lipid peroxidation. CCl4 induced lipid peroxidation and hepatotoxicity were suppressed by administration of an α-adrenergic antagonist. We conclude that the SNS provides a permissive microenvironment for hepatic oxidative stress indicating the possibility that targeting the hepatic α-adrenergic signaling could be a viable strategy for improving outcomes in patients with acute hepatic injury.

  7. Protective Effects of Alpha Lipoic Acid on Carbon Tetrachloride-Induced Liver and Kidney Damage in Rats

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    A.O. Morakinyo

    2012-02-01

    Full Text Available Carbon tetrachloride (CCl4 is a well known toxicant and exposure to this chemical is known to induce oxidative stress by the formation of free radicals. The present study investigates the in vivo effects of alpha lipoic acid (ALA on CCl4-induced hepatic and renal toxicities. Twenty-four Sprague-Dawley rats were divided into four groups of 6 animals each and treated for 10 consecutive days. Group 1 was given olive oil only. Group 2 received CCl4 intra-peritoneally (i.p. at a dose of 0.8 mg/kg as a 30% olive oil solution. Group 3 was given ALA only at a dose 25 mg/kg. Group 4 was given both CCl4 and ALA, respectively. At the end of experiment, the antioxidant status in both the liver and kidney tissues were estimated by determining the activities of antioxidant enzymes; reduced glutathione, superoxide dismutase, catalase as well as the level of lipid peroxidation via thiobarbituric reactive substance. The liver and kidney functions tests were also performed in addition to their histopathological evaluation. Results obtained showed significant adverse changes in the levels of all measured parameters in CCl4 treated rats. However, treatment with ALA attenuated the adverse changes in the CCl4-induced rats. Our findings suggest that ALA protects the liver and kidney against CCl4-induced damage through its significant effects on the antioxidant activities.

  8. 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

  9. Fate of biomolecules during carbon tetrachloride induced oxidative stress and protective nature of Ammoniac baccifera Linn.: A natural antioxidant

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    Lavanya G

    2009-01-01

    Full Text Available Ethanol extract of Ammannia baccifera was studied for its protective nature against the oxidative damage of lipids, proteins and DNA in carbon tetrachloride (CCl 4 -induced toxicity in rats. CCl 4 administration to albino Wistar rats increased the levels of lipid peroxidation, protein carbonyls and decreased the levels of total sulfhydryls. CCl 4 also induced the elevation of DNA damage measured by the comet assay. The study revealed that the administration of the ethanol extract of A. baccifera to CCl 4 intoxicated rats could significantly ( P < 0.01 decrease the levels of lipid peroxidation, protein carbonyls and increased the levels of total sulfhydryls in a dose-dependent manner. It was also found that the ethanol extract of A. baccifera prevent the CCl 4 -induced elevation of DNA damage in hepatocytes. These results suggest that treatment with the ethanol extract of A. baccifera can minimize the deleterious effects caused by CCl 4 through its strong antioxidative and free radical scavenging properties.

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

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    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.

  11. Doxazosin Treatment Attenuates Carbon Tetrachloride-Induced Liver Fibrosis in Hamsters through a Decrease in Transforming Growth Factor β Secretion

    Science.gov (United States)

    Muñoz-Ortega, Martin Humberto; Llamas-Ramírez, Raúl Wiliberto; Romero-Delgadillo, Norma Isabel; Elías-Flores, Tania Guadalupe; de Jesus Tavares-Rodríguez, Edgar; del Rosario Campos-Esparza, María; Cervantes-García, Daniel; Muñoz-Fernández, Luis; Gerardo-Rodríguez, Martin; Ventura-Juárez, Javier

    2016-01-01

    Background/Aims The development of therapeutic strategies for the treatment of cirrhosis has become an important focus for basic and clinical researchers. Adrenergic receptor antagonists have been evaluated as antifibrotic drugs in rodent models of carbon tetrachloride (CCl4)-induced cirrhosis. The aim of the present study was to evaluate the effects of carvedilol and doxazosin on fibrosis/cirrhosis in a hamster animal model. Methods Cirrhotic-induced hamsters were treated by daily administration of carvedilol and doxazosin for 6 weeks. Hepatic function and histological evaluation were conducted by measuring biochemical markers, including total bilirubin, aspartate aminotransferase, alanine aminotransferase and albumin, and liver tissue slices. Additionally, transforming growth factor β (TGF-β) immunohistochemistry was analyzed. Results Biochemical markers revealed that hepatic function was restored after treatment with doxazosin and carvedilol. Histological evaluation showed a decrease in collagen type I deposits and TGF-β-secreting cells. Conclusions Taken together, these results suggest that the decrease in collagen type I following treatment with doxazosin or carvedilol is achieved by decreasing the profibrotic activities of TGF-β via the blockage of α1- and β-adrenergic receptor. Consequently, a diminution of fibrotic tissue in the CCl4-induced model of cirrhosis is achieved. PMID:26573293

  12. 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.

  13. Toxicological and biochemical studies on Schinus terebinthifolius concerning its curative and hepatoprotective effects against carbon tetrachloride-induced liver injury

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    Rania H Abdou

    2015-01-01

    Full Text Available Background: Recently, many efforts have been made to discover new products of natural origin which can limit the xenobiotic-induced hepatic injury. Carbon tetrachloride (CCl 4 is a highly toxic chemical that is widely used to study hepatotoxicity in animal models. Objective: The present study was conducted to investigate the curative and protective effects of Schinus terbenthifolius ethanolic extract against CCl 4 -induced acute hepatotoxicity in rats. Materials and Methods: S. terbenthifolius extract was orally administered in a dose of 350 mg dried extract/kg b.wt. before and after intoxication with CCl 4 for curative and protective experiments, respectively. A group of hepatotoxicity indicative enzymes, oxidant-antioxidant capacity, DNA oxidation, and apoptosis markers were measured. Results: CCl 4 increased liver enzyme leakage, oxidative stress, hepatic apoptosis, DNA oxidation, and inflammatory markers. Administration of S. terebinthifolius, either before or after CCl 4 intoxication, significantly decreased elevated serum liver enzymes and reinstated the antioxidant capacity. Interestingly, S. terebinthifolius extract inhibited hepatocyte apoptosis as revealed by approximately 20 times down-regulation in caspase-3 expression when compared to CCl 4 untreated group. On the other hand, there was neither protective nor curative effect of S. terebinthifolius against DNA damage caused by CCl 4 . Conclusion: The present study suggests that S. terebinthifolius extract could be a substantially promising hepatoprotective agent against CCl 4 toxic effects and may be against other hepatotoxic chemical or drugs.

  14. 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

  15. Hepatoprotective effect of the pulp/seed of Aegle marmelos correa ex Roxb against carbon tetrachloride induced liver damage in rats

    OpenAIRE

    Singh Ramnik; Rao Harwinder

    2008-01-01

    A number of herbal preparations are widely used in traditional system of medicine for the management of hepatic disorders. However, many of them have not been investigated for their described effects. Aegle marmelos Roxb is one such drug used in the treatment of hepatitis in folk medicine. Therefore, an attempt has been made to investigate for hepatoprotective effect of fruits of Aegle marmelos against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in rats. Sixty Albino Wistar rats were...

  16. 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 ...

  17. 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

  18. 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

  19. 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

  20. 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.

  1. Role of quercetin and vitamin c in quenching oxidative damage induced by ionizing radiation and carbon tetrachloride in rats

    International Nuclear Information System (INIS)

    The aim of the present investigation is to evaluate the protective effect of a mixture of quercetin and vitamin C against cirrhotic liver and oxidative stress induced in rats by administration of carbon tetrachloride (CCl4) and/ or exposure to ionizing radiation.Lipid peroxidation as malondialdehyde (MDA) was determined in plasma as an indicator for cytotoxicity. Blood glutathione (GSH) was estimated as a marker of antioxidant status. Total protein, albumin, globulin, A/G ratio, aminotransferases (AST, ALT) and alkaline phospahatase were assayed in plasma as indicators for liver function beside lactate dehydrogenase which was measured to evaluate liver inflammation.The data revealed significant elevation in MDA level accompanied by a reduced level of GSH due to CCl4 administration and / or radiation damage. Furthermore, the data obtained showed significant increase in A/G ratio and decrease in total protein and globulin beside significant increases in AST, ALT, ALP and LDH levels. Treatment with quercetin and vitamin C improved liver function and reduced the severity of liver injury which was reflected by the lower concentrations of lipid peroxidation and the proinflammatory indicator LDH. Those effects were linked to peroxyl radical trapping capacity of quercetin and vitamin C. It could be concluded that a mixture of quercetin and vitamin C is effective in this model of liver damage and could be used as useful supplement in the treatment of liver inflammatory status and oxidative stress

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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

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

    International Nuclear Information System (INIS)

    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 (CCl4)-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 CCl4-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 CCl4-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 CCl4-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 CCl4, 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

  8. 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.

  9. 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.

  10. The protective effect of silymarin on the carbon tetrachloride (CCl4)-induced liver injury in common carp (Cyprinus carpio).

    Science.gov (United States)

    Jia, Rui; Cao, Liping; Du, Jinliang; Xu, Pao; Jeney, Galina; Yin, Guojun

    2013-03-01

    Silymarin, a mixture of bioactive flavonolignans from the milk thistle (Silybum marianum), is traditionally used in herbal medicine to defend against various hepatotoxic agents. The aim of the present study was to evaluate the protective effect of silymarin against carbon tetrachloride (CCl4)-induced liver injury in fish. Common carp, with an average initial weight of 17.0 ± 1.1 g, were fed diet containing four doses of silymarin (0, 0.1, 0.5, and 1 g/kg diet) for 60 d. Fish were then given an intraperitoneal injection of CCl4 (30% in arachis oil) at a dose of 0.5 ml/kg body weight. At 72 h after CCl4 injection, blood and liver samples were collected for the analyses of serum biochemical parameters, liver index, peroxidation product, glutathione, and antioxidant enzyme activities. The results showed that administration of silymarin at 0.5 and 1 g/kg diet for 60 d prior to CCl4 intoxication significantly reduced the elevated activities of glutamate pyruvate transaminase, glutamate oxalate transaminase, lactate dehydrogenase (LDH), and increased the reduced levels of total protein and albumin in the serum. The reduced levels of liver index, superoxide dismutase, glutathione peroxidase, catalase, glutathione, and total antioxidant capacity were markedly increased, and malondialdehyde formation was significantly restrained in the liver. However, these parameters, except LDH, were not significantly changed in fish fed with silymarin at 0.1 g/kg diet. Based on the results, it can be concluded that silymarin has protective effect against CCl4-induced hepatotoxicity in fish. It is suggested that silymarin may be used as a hepatoprotective agent to prevent liver diseases in fish. PMID:23435858

  11. 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.

  12. 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.

  13. 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.

  14. 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,...

  15. 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

  16. 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

  17. 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

  18. Hepatoprotective effects of solanum nigrum extracts on carbon tetrachloride (CCl4) induced hepatotoxicity in rats

    International Nuclear Information System (INIS)

    Effects of aqueous and alcoholic extracts of Solanum nigrum were investigated against CCl4 induced hepatic damage in male albino rats of Sprague Dowley Strain. Enzymatic activities i.e. Aspartate Transaminase, Alanine Transaminase and Alkaline Phosphatase, and gross microscopic appearance of liver were used as parameters and hepato protective studies were performed. In case of hepato protective study i.e. pre-treatment of rats with aqueous extracts of plant (500 mg orally, two doses with 24 hours interval) prevented (p <0.001) CCl4 induced rise in activity of serum Transaminases (ALT and AST) and ALP, whereas the alcoholic extract did not prevent the rise of same enzymes, compared to the sham control group in which liver was damaged by CCI4, no treatment given. Histological examination of the liver of animals treated with aqueous extract of plant showed that change in fatty acids was less in comparison to the sham control group. In the treated group, reduction in body-weight was minimal and liver enlargement was also less, as compared to the animals in sham control group. These results indicate that only aqueous extract of Solanum nigrum exhibits hepatoprotective effects, at least within the parameters of the present study. (author)

  19. 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

  20. 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.

  1. Elucidation of the mechanism of vitamin A potentiation of carbon tetrachloride-induced liver injury

    International Nuclear Information System (INIS)

    Male SD rats were given Vitamin A daily for 7 days by oral gavage. 24 hr after the last dose of Vitamin A, they were then challenged with CCl4. Ethane, as a marker of lipid peroxidation, was measured during the first 2 hr and hepatic injury was assessed at 24 hr after CCl4. There was approximately 5-fold increase in ethane exhalation and 17-fold increase in Plasma GPT activity in Vitamin A/CCl4 group. There was also increase in the incidence of hepatocellular necrosis. Vitamin A pretreatment did not increase the metabolism of 14CCl4 as examined by the amount of exhaled 14CO2, and the covalent binding of 14C-equivalents to liver lipids and proteins. In addition, liver levels of Vitamin E or GSH were not changed by Vitamin A. Electron microscopic analysis of livers from Vitamin A treated rats revealed activated Kupffer cells. To determine if the Kupffer cells were functionally more active, the clearance of intravenously administered colloidal carbon from the blood of Vitamin A treated rats was compared to that of control rats

  2. Impact of a CXCL12/CXCR4 Antagonist in Bleomycin (BLM) Induced Pulmonary Fibrosis and Carbon Tetrachloride (CCl4) Induced Hepatic Fibrosis in Mice

    Science.gov (United States)

    Chow, Leola N.; Schreiner, Petra; Ng, Betina Y. Y.; Lo, Bernard; Hughes, Michael R.; Scott, R. Wilder; Gusti, Vionarica; Lecour, Samantha; Simonson, Eric; Manisali, Irina; Barta, Ingrid; McNagny, Kelly M.; Crawford, Jason; Webb, Murray; Underhill, T. Michael

    2016-01-01

    Modulation of chemokine CXCL12 and its receptor CXCR4 has been implicated in attenuation of bleomycin (BLM)-induced pulmonary fibrosis and carbon tetrachloride (CCl4)-induced hepatic injury. In pulmonary fibrosis, published reports suggest that collagen production in the injured lung is derived from fibrocytes recruited from the circulation in response to release of pulmonary CXCL12. Conversely, in hepatic fibrosis, resident hepatic stellate cells (HSC), the key cell type in progression of fibrosis, upregulate CXCR4 expression in response to activation. Further, CXCL12 induces HSC proliferation and subsequent production of collagen I. In the current study, we evaluated AMD070, an orally bioavailable inhibitor of CXCL12/CXCR4 in alleviating BLM-induced pulmonary and CCl4-induced hepatic fibrosis in mice. Similar to other CXCR4 antagonists, treatment with AMD070 significantly increased leukocyte mobilization. However, in these two models of fibrosis, AMD070 had a negligible impact on extracellular matrix deposition. Interestingly, our results indicated that CXCL12/CXCR4 signaling has a role in improving mortality associated with BLM induced pulmonary injury, likely through dampening an early inflammatory response and/or vascular leakage. Together, these findings indicate that the CXCL12-CXCR4 signaling axis is not an effective target for reducing fibrosis. PMID:26998906

  3. Hepatoprotective effects of citric acid and aspartame on carbon tetrachloride-induced hepatic damage in rats

    OpenAIRE

    Omar M. E. Abdel Salam; Shaffie, Nermeen M.; Sleem, Amany A.

    2009-01-01

    The aim of this study was to investigate the effect of citric acid or the sweetening agent aspartame on the CCl4-induced hepatic injury in rats. Citric acid (10 mg/kg, 100 mg/kg or 1000 mg/kg), aspartame (0.625 or 1.25 mg/kg) or silymarin (25 mg/kg) was given once daily orally simultaneously with CCl4 and for one week thereafter. The administration of citric acid at 100 mg/kg or 1000 mg/kg to CCl4-treated rats reduced elevated plasma ALT by 44.1-63.3 %, AST by 47.8-70.6 %, ALP by 41.7-67.2 %,...

  4. Epidermal growth factor protects against carbon tetrachloride-induced hepatic injury.

    Science.gov (United States)

    Berlanga, J; Caballero, M E; Ramirez, D; Torres, A; Valenzuela, C; Lodos, J; Playford, R J

    1998-03-01

    1. Epidermal growth factor (EGF) is known to protect the gastrointestinal tract against various noxious agents. Its potential value in preventing/ treating hepatic injury is, however, largely unexplored. We therefore examined whether EGF could influence CCl4-induced hepatic injury. 2. Female Sprague-Dawley rats (8 per group) received saline or recombinant EGF (500 or 750 micrograms/kg, intraperitoneal) 30 min before CCl4 (20% v/v, in olive oil, intraperitoneal). Eighteen hours later, animals were killed, serum was collected for assay of biochemical markers of hepatic injury and livers were removed for histological analyses. 3. Administration of CCl4 resulted in severe hepatic necrosis and caused a 10-fold rise in plasma alanine aminotransferase levels compared with levels seen in control animals (218 +/- 15 compared with 23 +/- 9 mumol/l in controls, mean +/- SEM, P < 0.01). Serum malondialdehyde levels, used as a marker of lipid peroxidation, showed a 2-fold rise in response to CCl4 treatment (median 4.0, quartile range 3.3-5.8 units/l compared with median 2.3, quartile range 2.1-2.5 units/l in controls, P < 0.05). Administration of EGF at 500 micrograms/kg, before the CCl4, did not protect against injury, as assessed by histology or rise in plasma alanine aminotransferase levels. In contrast, animals given EGF at 750 micrograms/kg, before the CCl4, had only minimal changes in histology, with only a minor rise in alanine aminotransferase levels (37 +/- 4 compared with 23 +/- 9 mumol/l in animals not given CCl4) and had no significant rise in malondialdehyde levels. 4. EGF protects against CCl4-induced hepatic injury and may provide a novel approach to the treatment of liver damage. PMID:9616254

  5. 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

  6. 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.

  7. 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

  8. (Z-5-(4-methoxybenzylidenethiazolidine-2,4-dione protects rats from carbon tetrachloride-induced liver injury and fibrogenesis

    Directory of Open Access Journals (Sweden)

    Zhi-Zhi Chen

    2012-01-01

    Full Text Available AIM: To evaluate the hepatoprotective roles of (Z-5-(4-methoxybenzylidenethiazolidine-2,4-dione (SKLB010 against carbon tetrachloride (CCl4-induced acute and chronic liver injury and its underlying mechanisms of action. METHODS: In the first experiment, rats were weighed and randomly divided into 5 groups (five rats in each group to assess the protective effect of SKLB010 on acute liver injury. For induction of acute injury, rats were administered a single intraperitoneal injection of 2 mL/kg of 50% (v/v CCl4 dissolved in olive oil (1:1. Group 1 was untreated and served as the control group; group 2 received CCl4 for induction of liver injury and served as the model group. In groups 3, 4 and 5, rats receiving CCl4 were also treated with SKLB010 at doses of 25, 50 and 100 mg/kg, respectively. Blood samples were collected at 6, 12 and 24 h after CCl4 intoxication to determine the serum activity of alanine amino transferase. Tumour necrosis factor-α (TNF-α, interleukin-1β (IL-1β were determined using enzyme-linked immunosorbent assay. At 24 h after CCl4 injection,liver fibrogenesis was evaluated by hematoxylin-eosin (HE staining and immunohistochemical analyses. Cytokine transcript levels of TNF-α, IL-1β and inducible nitric oxide synthase in the liver tissues of rats were measured using a reverse transcriptase reverse transcription-polymerase chain reaction technique. In the second experiment, rats were randomly divided into 2 groups (15 rats in each group, and liver injury in the CCl4-administered groups was induced by a single intraperitoneal injection of 2 mL/kg of 50% (v/v CCl4 dissolved in olive oil (1:1. The SKLB010-treated groups received oral 100 mg/kg SKLB010 before CCl4 administration. Five rats in each group were sacrificed at 2 h, 6 h, 12 h after CCl4 intoxication and small fortions of livers were rapidly frozen for extraction of total RNA, hepatic proteins and glutathione (GSH assays. In the hepatic fibrosis model group, rats

  9. Protective effect of compounds from the flowers of Citrus aurantium L. var. amara Engl against carbon tetrachloride-induced hepatocyte injury.

    Science.gov (United States)

    Lu, Qun; Yang, Li; Zhao, Hai-Yan; Jiang, Jian-Guo; Xu, Xi-Lin

    2013-12-01

    5-Hydroxy-6,7,3',4'-tetramethoxyflavone (HTF), limonexic acid (LA) are two compounds isolated from the flowers of Citrus aurantium L. var. amara Engl with various biological activities. This study was designed to investigate their protective effects against carbon tetrachloride (CCl4)-induced hepatocyte injury, using human hepatic cell line HL-7702 to determine the cell cytotoxicity, cell viability, levels of hepatic marker enzymes, malondialdehyde (MDA). Results showed that pretreatment with HTF, LA could significantly reverse CCl4-induced HL-7702 cell viability decrease, LA displayed a higher activity. HTF, LA also showed their capability of decreasing the CCl4-induced leakage of lactate dehydrogenase (LDH), aspartate aminotransferase (AST), inhibiting the lipid peroxidation, HTF showed more significant activity. Given that HTF, LA were not toxic, it is concluded that HTF, LA could effectively protect hepatocyte against CCl4-induced injury. PMID:23985451

  10. 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.

  11. 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

  12. Influence of methyl and isopropyl N-methyl antranilates on carbon tetrachloride-induced changes in rat liver morphology and function

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    Radulović Niko S.

    2013-01-01

    Full Text Available The aim of the present study was to examine potential protective effects of methyl N-methylanthranilate (M and isopropyl N-methylanthranilate (I in a rat model of acute intoxication with carbon tetrachloride (CCl4 by tracking the changes in liver morphology and function. Serum transaminase and bilirubin were significantly elevated in animals treated with CCl4 alone. A pretreatment with M and I prior to the administration of CCl4 significantly prevented the increase of serum levels of liver damage markers. Histopathological evaluation of the livers of the test animals also revealed that M and I reduced the incidence of liver lesions. Our experiments showed that both M and I possess protective effect in CCl4-induced liver damage in rats. The results are of interest due to the presence of natural or synthetic M in the human diet. [Projekat Ministarstva nauke Republike Srbije, br. 172061

  13. 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.

  14. 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.

  15. Hepatoprotective and anti-hepatitis C viral activity of Platycodon grandiflorum extract on carbon tetrachloride-induced acute hepatic injury in mice.

    Science.gov (United States)

    Kim, Tae-Won; Lim, Jong-Hwan; Song, In-Bae; Park, Sang-Jin; Yang, Jae-Won; Shin, Jung Cheul; Suh, Joo-Won; Son, Hwa-Young; Cho, Eun-Sang; Kim, Myoung-Seok; Lee, Sang-Wook; Kim, Jong-Woo; Yun, Hyo-In

    2012-01-01

    The present study aims to evaluate the anti-HCV activity of hotwater extract from Platycodon grandiflorum (BC703) with HCV genotype 1b subgenomic replicon system and investigate its hepatoprotective activity on carbon tetrachloride (CCl(4))-induced acute liver damage in mice. BC703 produced significant hepatoprotective effects against CCl(4)-induced acute hepatic injury by decreasing the activities of serum enzymes, nitric oxide and lipid peroxidation. Histopathological studies further substantiated the protective effect of BC703. Furthermore, BC703 inhibited the HCV RNA replication with an EC(50) value and selective index (CC(50)/EC(50)) of 2.82 µg/mL and above 35.46, respectively. However, digested BC703 using a simulated gastric juice showed poor protective effect against CCl(4)-induced hepatotoxicity in mice and decreased anti-HCV activity as compared to the intact BC703. Although further studies are necessary, BC703 may be a beneficial agent for the management of acute hepatic injury and chronic HCV infection. PMID:22878389

  16. Hepatoprotective effect of the pulp/seed of Aegle marmelos correa ex Roxb against carbon tetrachloride induced liver damage in rats

    Directory of Open Access Journals (Sweden)

    Singh Ramnik

    2008-01-01

    Full Text Available A number of herbal preparations are widely used in traditional system of medicine for the management of hepatic disorders. However, many of them have not been investigated for their described effects. Aegle marmelos Roxb is one such drug used in the treatment of hepatitis in folk medicine. Therefore, an attempt has been made to investigate for hepatoprotective effect of fruits of Aegle marmelos against carbon tetrachloride (CCl 4 induced hepatotoxicity in rats. Sixty Albino Wistar rats were divided into six equal groups of 10. Four groups received extracts of pulp/seeds of Aegle marmelos and intraperitoneal (i.p. CCl 4 (0.2 ml/100 g either before or after administration of pulp/seeds. Two groups were controls, one treated with CCl 4 and one with normal saline. Liver damage was assessed by plasma concentration of bilirubin and enzyme activities of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Treatment with aqueous extract of fruit pulp/seeds significantly reduced CCl 4 -induced elevation in plasma enzyme and bilirubin concentration in rats. This study suggests that CCl 4 -induced liver damage in rats can be ameliorated by treatment of extracts from fruits pulp/seeds.

  17. 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

  18. 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.

  19. Protective action of the immunomodulator ginsan against carbon tetrachloride-induced liver injury via control of oxidative stress and the inflammatory response

    International Nuclear Information System (INIS)

    The aim of the present study was to evaluate immunomodulator ginsan, a polysaccharide extracted from Panax ginseng, on carbon tetrachloride (CCl4)-induced liver injury. BALB/c mice were injected i.p. with ginsan 24 h prior to CCl4 administration. Serum liver enzyme levels, histology, expression of antioxidant enzymes, and several cytokines/chemokines were subsequently evaluated. Ginsan treatment markedly suppressed the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and hepatic histological necrosis increased by CCl4 treatment. Ginsan inhibited CCl4 induced lipid peroxidation through the cytochrome P450 2E1 (CYP2E1) downregulation. The hepatoprotective effect of ginsan was attributed to induction of anti-oxidant protein contents, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) as well as restoration of the hepatic glutathione (GSH) concentration. The marked increase of proinflammatory cytokines (IL-1β, IFN-γ) and chemokines (MCP-1, MIP-2β, KC) in CCl4 treated mice was additionally attenuated by ginsan, thereby preventing leukocyte infiltration and local inflammation. Our results suggest that ginsan effectively prevent liver injury, mainly through downregulation of oxidative stress and inflammatory response.

  20. 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

  1. Hepatoprotective effect of the solvent fractions of the stem of Hoslundia opposita Vahl (Lamiaceae against carbon tetrachloride- and paracetamol-induced liver damage in rats

    Directory of Open Access Journals (Sweden)

    Akah Peter

    2010-01-01

    Full Text Available The hepatoprotective potentials of the stem solvent fractions of Hoslundia opposita Vahl were investigated. The fractions were prepared and tested for hepatoprotective effect against carbon tetrachloride (CCl 4 and paracetamol-induced liver damage in rats. Changes in the levels of biochemical markers of hepatic injury viz; -aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP and bilirubin were determined in both treated and control groups of rats. The effects of the extracts were compared with that of sylimarin (100 mg/kg. Phytochemical analysis and acute toxicity studies of the extract were also performed. The results showed that CCl 4 and paracetamol (2 g/kg elevated the levels of AST, ALT, ALT and bilirubin. Treatment with the methanol extract and methanol and ethyl acetate fractions of Hoslundia opposita (100 mg/kg ameliorated the effects of the hepatoxins and significantly (P>0.05 reduced the elevated levels of the biochemical marker enzymes, while the chloroform and hexane fractions showed no significant (P< 0.05 hepatoprotective effect. The extracts showed good toxicity profile with an LD50 value above 5000 mg/kg for the methanol extract. Phytochemical analysis showed the presence of resins, flavonoids, sterols/triterpenes, tannins, saponins, alkaloids, reducing sugars, cardiac glycosides and proteins in the solvent fractions. These results suggest that the stem of Hoslundia opposita contains bioactive principles with hepatoprotective effect.

  2. 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.

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

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    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.

  4. Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats

    Science.gov (United States)

    Wohlenberg, Mariane; Almeida, Daniela; Bokowski, Liane; Medeiros, Niara; Agostini, Fabiana; Funchal, Cláudia; Dani, Caroline

    2014-01-01

    In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl4). The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS) were unchanged. However, CCl4 induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD) activity was increased by CCl4 in the cerebral cortex and decreased in other tissues. However, CCl4 increased catalase (CAT) activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract. PMID:26784867

  5. Antioxidant Activity of Grapevine Leaf Extracts against Oxidative Stress Induced by Carbon Tetrachloride in Cerebral Cortex, Hippocampus and Cerebellum of Rats

    Directory of Open Access Journals (Sweden)

    Mariane Wohlenberg

    2014-04-01

    Full Text Available In recent years, it has become increasingly important to study the beneficial properties of derivatives of grapes and grapevine. The objective of this study was to determine the antioxidant activity of Vitis labrusca leaf extracts, comparing conventional and organic grapevines, in different brain areas of rats. We used male Wistar rats treated with grapevine leaf extracts for a period of 14 days, and on the 15th day, we administered in half of the rats, mineral oil and the other half, carbon tetrachloride (CCl4. The animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were removed to assess oxidative stress parameters and the activity of antioxidant enzymes. Lipid peroxidation levels (TBARS were unchanged. However, CCl4 induced oxidative damage to proteins in all tissues studied, and this injury was prevented by both extracts. Superoxide dismutase (SOD activity was increased by CCl4 in the cerebral cortex and decreased in other tissues. However, CCl4 increased catalase (CAT activity in the cerebellum and decreased it in the cerebral cortex. The SOD/CAT ratio was restored in the cerebellum by both extracts and only in the cerebral cortex by the organic extract.

  6. Determination of the key innate genes related to individual variation in carbon tetrachloride-induced hepatotoxicity using a pre-biopsy procedure

    International Nuclear Information System (INIS)

    High inter-individual variation in chemical-induced liver injury is a frequent observation with many hepatotoxic chemicals, yet the mechanism underlying it remains poorly understood. Even with carbon tetrachloride (CCl4), a well-known model hepatotoxicant, substantial individual variations are observed in the severity of liver injury. Using microarray, many attempts have been made to identify the key genes in CCl4-induced liver injury but mostly, they examined the gene expression of liver after CCl4 exposure, unable to dissect out the complicating factors from pathological changes secondary to liver injury. To more accurately identify the genes for the individual variation in CCl4-induced hepatotoxicity, we compared the innate gene expression of the individual liver samples pre-biopsied prior to CCl4-treatment with the severity of liver injury after CCl4-treatment. Effect of biopsy procedure and 3 week recovery period on liver function and gene expression were confirmed to be insignificant. Using this design, we found that the expression of genes associated with immunity and defense, lipid metabolism, transport and complement-mediated immunity, which are previously known to be suppressed by CCl4-treatment, were innately lower in the susceptible animals than resistant animals. Moreover, we demonstrated that the genes such as Gsta2, Sult2a1, Fgl1 and C6 were newly found to be innately lower in the susceptible animals to CCl4-hepatotoxicity. These naturally lower gene expression patterns were further confirmed by RT-PCR. We believe that this pre-biopsy design may provide a useful tool for understanding the cause of variability of hepatotoxicity and for the prediction and pre-screening of the susceptible individual to drug-induced hepatotoxicity.

  7. 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

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

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. 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.

  11. 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

  12. 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...

  13. 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...

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. The Carbon Tetrachloride (CCl4) Budget: Mystery or Not

    Science.gov (United States)

    Liang, Qing; Newman, Paul A.; Daniel, John S.; Reimann, Stefan; Hall, Bradley; Dutton, Geoff; Kuijpers, Lambert J. M.

    2014-01-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance and greenhouse gas and has been regulated under the Montreal Protocol. However, atmospheric observations show a very slow decline in CCl4 concentrations, inconsistent with the nearly zero emissions estimate based on the UNEP reported production and feedstock usage in recent years. It is now apparent that there are either unidentified industrial leakages, an unknown production source of CCl4, or large legacy emissions from CCl4 contaminated sites. In this paper we use a global chemistry climate model to assess the budget mystery of atmospheric CCl4. We explore various factors that affect the global trend and the gradient between the Northern and Southern hemispheres or interhemispheric gradient (IHG): emissions, emission hemispheric partitioning, and lifetime variations. We find a present-day emission of 30-50 Gg per yr and a total lifetime 25 - 36 years are necessary to reconcile both the observed CCl4 global trend and IHG.

  11. Biological effects of pesticides on rats treated with carbon tetrachloride

    International Nuclear Information System (INIS)

    The present study investigates the effect of repeated oral doses of the organophosphorus pesticide, cytrolane on normal and pretreated rate with different oral doses of carbon tetrachloride. For that purpose the effect of cytrolane, CCl4 and their potential interaction had been studied on brain and erythrocyte acetylcholinesterase (Ache), plasma cholinesterase (Ch E), liver succinic dehydrogenase (SDH), serum alkaline phosphatase (SAP), liver succinic dehydrogenas (SDH), serum alkaline phosphatase (SAP), glutamic oxaloacetic (GOT) and glutamic pyruvic (GPT) transaminases. It also investigates the effect of an acute oral dose of cytrolane at short time intervals (1/2-24 hours) on brain and blood ache of normal and pretreated rate with a single oral dose of CCl4. The distribution and excretion of 14cc14 at different time intervals (2,6 and 24 hours) in normal rats and in rats pretreated with o.89 mg cytrolane/kg/day for a week had been determined in different organs, expired air, urine and faeces

  12. FY 93 site characterization status report and data package for the carbon tetrachloride site

    Energy Technology Data Exchange (ETDEWEB)

    Rohay, V.J. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-09-28

    This report provides the status and accomplishments from fiscal year site characterization activities conducted as part of the 200 West Area Carbon Tetrachloride Expedited Response Action and the Volatile Organic Compounds - Arid Integrated Demonstration. The report includes or references all available raw data collected as part of these tasks. During fiscal year 1993, the 200 West Area Carbon Tetrachloride Expedited Response Action and the Volatile Organic Compounds - Arid Integrated Demonstration programs focused on the carbon tetrachloride plume in the unsaturated zone underlying the 200 West Area at the Hanford Site in southeast Washington.

  13. Further details concerning the radiolysis of a carbon tetrachloride-benzene mixture (1961)

    International Nuclear Information System (INIS)

    The neutron-activation estimation of the chlorine fixed on DPPH during radiolysis of the mixture C6H6-CCl4 makes it possible to evaluate the contribution of the carbon tetrachloride to the overall phenomenon. (authors)

  14. Yields of light products in the radiolysis of isooctane-carbon tetrachloride mixtures

    International Nuclear Information System (INIS)

    The radiolysis of isooctane-carbon tetrachloride mixtures was studied. The yields of light froducts from isooctane (hydrogen, methane, isobutane and isobutene) were determined depending on the electron fraction of carbon tetrachloride. The isooctane parent ion C8H18+ produced by 'indirect' ionization was shown to be unstable and to decompose via a series of competing processes including C-C bond rupture. (author)

  15. Enhanced anaerobic transformations of carbon tetrachloride by soil organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Collins, R.; Picardal, F.

    1999-12-01

    Anaerobic, reductive dehalogenation of carbon tetrachloride (CT) by Shewanella putrefaciens 200 is enhanced by the presence of a high-organic-carbon soil. In microbial incubations without soil, 29% of the initial 3 ppm CT was transformed after 33 h, whereas 64% was transformed after only 18 h when soil was present. In sterile, biomimetic systems using a chemical reductant, 20 mM dithiothreitol, similar results were observed, suggesting that abiotic electron-transfer mediators in the soil were catalyzing the reaction. Destruction of 62% of the soil organic carbon by H{sub 2}O{sub 2} resulted in a soil that was less effective in enhancing CT dechlorination. Following separation of the soil organic matter into three humic fractions, the humic acid (HA) fraction catalyzed the dechlorination reaction to a greater extent than did the fulvic acid (FA) fraction, and both were more effective than the fraction containing humin and inorganic minerals. The results are consistent with a mechanism involving humic functional groups that serve as electron-transfer mediators able to enhance the reductive transformation of CT in the presence of a microbial or chemical reductant. Humic functional group analyses showed that the FA contained more total acidity and carboxylic acidity than did the HA; however, both fractions contained similar amounts of total carbonyl groups and quinone carbonyls. Abiotic, HA-mediated CT transformation was observed regardless of whether dithiothreitol was present or not. At circumneutral pH, HA-mediated CT transformation required the presence of dithiothreitol. At pH 8.7, HA-mediated reductive CT transformation occurred both in the absence or presence of dithiothreitol although the transformation was greater in the presence of a reductant. Trichloromethane (chloroform [CF]) production at pH 8.7 was much lower than at circumneutral pH, and volatile organic compounds other than CF were not detected as products in any case.

  16. 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

  17. 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.

  18. 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)

  19. 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

  20. Self-Templated Synthesis of Mesoporous Carbon from Carbon Tetrachloride Precursor for Supercapacitor Electrodes.

    Science.gov (United States)

    Tang, Duihai; Hu, Shi; Dai, Fang; Yi, Ran; Gordin, Mikhail L; Chen, Shuru; Song, Jiangxuan; Wang, Donghai

    2016-03-23

    A high-surface-area mesoporous carbon material has been synthesized using a self-templating approach via reduction of carbon tetrachloride by sodium potassium alloy. The advantage is the reduction-generated salt templates can be easily removed with just water. The produced mesoporous carbon has a high surface area and a narrow pore size distribution. When used as a supercapacitor electrode, this material exhibits a high specific capacitance (259 F g(-1)) and excellent cycling performance (>92% capacitance retention for 6000 cycles). PMID:26913815

  1. 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.

  2. 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

  3. 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

  4. Accelerated cleanup of carbon tetrachloride in a radiologically contaminated site at the Hanford Site

    International Nuclear Information System (INIS)

    Radioactively-contaminated acidic aqueous wastes and organic liquids were discharged to the soil column at three disposal sites within the Hanford Nuclear Reservation, resulting in the carbon tetrachloride contamination of the ground water and unsaturated soils. A CERCLA Expedited Response Action (ERA) has been initiated for the removal of carbon tetrachloride from the unsaturated soils to mitigate further contamination of the ground water. Based on the contaminant nature and distribution, site physical characteristics, and technology pilot tests, soil vapor extraction with above-ground treatment of the soil vapor was chosen as the preferred remedial technology for the ERA

  5. Performance Evaluation Report for Soil Vapor Extraction Operations at the Carbon Tetrachloride Site, February 1992 - September 1998

    International Nuclear Information System (INIS)

    Soil vapor extraction (SVE) is being used to remove carbon tetrachloride from the vadose zone at the 200-ZP-2 Operable Unit. The purpose of this report is to evaluate both the SVE system operating data and the effectiveness of SVE in remediating the carbon tetrachloride contamination. This report has been revised to cover the operating period from February 25, 1992 through September 30, 1998. The scope of the report includes the history of SVE operations at 200-ZP-2, the efficiency of those operations over time, the volume of vapor processed per extraction system, the change in carbon tetrachloride concentrations with time, the mass of carbon tetrachloride removed per site, and recommendations for future operations and evaluations. This revision includes an update to the carbon tetrachloride conceptual model

  6. 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

  7. Evaluation of the effectiveness of Rosmarinus officinalis (Lamiaceae) in the alleviation of carbon tetrachloride-induced acute hepatotoxicity in the rat.

    Science.gov (United States)

    Sotelo-Félix, J I; Martinez-Fong, D; Muriel, P; Santillán, R L; Castillo, D; Yahuaca, P

    2002-07-01

    The effect of oral administration of Rosmarinus officinalis L. (Lamiaceae) on CCl(4)-induced acute liver injury was investigated. Rats were daily treated with the plant extract at a dose of 200 mg/kg corresponding to 6.04 mg/kg of carnosol as determined by reverse phase high-performance liquid chromatography. The treatment was initiated 1 h after CCl(4) administration and Rosmarinus officinalis fully prevented CCl(4) effect on hepatic lipid peroxidation after 24 h of CCl(4) administration. The increase in bilirubin level and alanine aminotransferase activity in plasma induced by CCl(4) was completely normalized by Rosmarinus officinalis. The treatment also produced a significant recovery of CCl(4)-induced decrease in liver glycogen content. CCl(4) did not modify the activity of liver cytosolic glutathione S-transferase (GST) compared with that of control groups. However, Rosmarinus officinalis increased liver cytosolic GST activity and produced an additional increment in plasma GST activity in rats treated with CCl(4). Histological evaluation showed that Rosmarinus officinalis partially prevented CCl(4)-induced inflammation, necrosis and vacuolation. Rosmarinus officinalis might exert a dual effect on CCl(4)-induced acute liver injury, acting as an antioxidant and improving GST-dependent detoxification systems. PMID:12065145

  8. 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

  9. Induction of lipid peroxidation by hexachlorocyclohexane, dieldrin, TCDD, carbon tetrachloride, and hexachlorobenzene in rats

    Energy Technology Data Exchange (ETDEWEB)

    Goel, M.R.; Shara, M.A.; Stohs, S.J.

    1988-02-01

    Hexachlorobenzene (HCB), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), hexachlorocyclohexane (HCCH) and dieldrin are all halogenated lipophilic environmental contaminants. A common biologic property of these compounds is their ability to induce hepatic microsomal drug metabolizing enzymes. Furthermore, exposure of laboratory animals to these xenobiotics elicits a number of similar effects including porphyria, hypothyroidism, a wasting syndrome and lethality. Perturbation of membrane lipids and lipid peroxidation may be responsible for at least part of the toxic effects of HCCH. TCDD has been shown to induce lipid peroxidation in hepatic and extrahepatic tissues. Based on the similar toxic manifestations of HCB, HCCH, TCDD and dieldrin, the authors have examined the effects of these xenobiotics on hepatic lipid peroxidation following an acutely toxic dose. Lipid peroxidation was assessed by determining the content of thiobarbituric acid reactive substance (TBARS) in the liver, employing malondialdehyde as the standard. Animals were also treated with carbon tetrachloride, a well know inducer of lipid peroxidation, as a positive control. Furthermore, the ability of these xenobiotics to inhibit selenium dependent glutathione peroxidase (GSHPX) activity was determined.

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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

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

    OpenAIRE

    Butler, J. H.; S. A. Yvon-Lewis; Lobert, J. M.; King, D. B.; S. A. Montzka; Bullister, J. L.; Koropalov, V.; J. W. Elkins; B. D. Hall; Hu, L.; Liu, Y.

    2016-01-01

    Abstract. 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 ...

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

    OpenAIRE

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

    2016-01-01

    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 ...

  18. 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

  19. 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.

  20. Histoprotective effect of vitamin D against carbon tetrachloride nephrotoxicity in rats.

    Science.gov (United States)

    Elmubarak, Smeo; Özsoy, N

    2016-07-01

    This study investigated the protective effect of vitamin D against carbon tetrachloride (CCl4)-induced nephrotoxicity in rats. Adult male Wistar albino rats were divided into four groups ((A) control; (B) 10-week exposure to CCl4; (C) 10-week exposure to CCl4 + vitamin D treatment; and (D) 10-week exposure to CCl4 + 12 weeks of vitamin D treatment). The CCl4 dose (1.5 ml kg(-1)) was injected subcutaneously twice a week, while the 0.5 mg kg(-1) dose of vitamin D was administered intraperitoneally every day, as appropriate for each group. Whole animal and kidney weights as well as serum urea, creatinine, and glucose levels were measured. Kidney tissue sections were stained with hematoxylin-eosin, Masson's trichrome, and periodic acid-Schiff. Tubular and glomerular degeneration were detected in the kidney tissues of CCl4-treated rats, together with dilatation and vacuolization within the tubules and hemorrhage in the intertubular region. In the kidney glomeruli; congestion, atrophy, and adhesion to parietal layer were observed. Tissue disorganization and aggregation of Bowman's capsules were noted. Mononuclear cell infiltration was observed between the glomeruli and the tubules. In contrast, the kidney sections and functional parameters of vitamin D-treated rats were similar to the controls, suggesting that vitamin D treatment is able to reduce renal damage. PMID:26293661

  1. 1994 conceptual model of the carbon tetrachloride contamination in the 200 West Area at the Hanford Site

    International Nuclear Information System (INIS)

    Between 1955 and 1973, a total of 363,000 to 580,000 L (577,000 to kg) of liquid carbon tetrachloride, in mixtures with other organic and aqueous, actinide-bearing fluids, were discharged to the soil column at three disposal facilities -- the 216-Z-9 Trench, the 216-Z-lA TiTe Field, and the 216-Z-18 Crib -- in the 200 West Area at the Hanford Site. In the mid-1980's, dissolved carbon tetrachloride was found in the uppermost aquifer beneath the disposal facilities, and in late 1990, the US Environmental Protection Agency and the Washington State Department of Ecology requested that the US Department of Energy proceed with planning and implementation of an expedited response action (ERA) to minimize additional carbon tetrachloride contamination of the groundwater. In February 1992, soil vapor extraction was initiated to remove carbon tetrachloride from the unsaturated zone beneath these disposal facilities. By May 1994, a total of 10,560 L (16,790 kg) of carbon tetrachloride had been removed, amounting to an estimated 2% of the discharged inventory. In the spring of 1991, the Volatile Organic Compounds -- Arid Integrated Demonstration (VOC-Arid ID) program selected the carbon tetrachloride-contaminated site for demonstration and deployment of new technologies for evaluation and cleanup of volatile organic compounds and associated contaminants in soils and groundwater at arid sites. Site investigations conducted in support of both the ERA and the VOC-Arid ID have been integrated because of their shared objective to refine the conceptual model of the site and to promote efficiency. Site characterization data collected in fiscal year 1993 have supported and led to refinement of the conceptual model of the carbon tetrachloride site

  2. 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

    similar to those found in heavily contaminated groundwater close to polluted industrial sites (14 988 mu M) was reduced mainly to the fully dechlorinated products carbon monoxide (CO, yields >54 and formic acid (HCOOH, yields >6. Minor formation of chloroform (CF), the only chlorinated degradation product......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...

  3. 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

  4. 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

  5. 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

  6. 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.

  7. 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...

  8. Degradation Kinetics of Carbon Tetrachloride by Sulfate Green Rust as Influenced by pH and Copper Ions (Stillwater)

    Science.gov (United States)

    Chlorinated solvents such as trichloroethene (TCE, C2HCl3) and carbon tetrachloride (CT, CCl4) are priority groundwater contaminants at many EPA field sites. Green rust (GR) minerals are important corrosion products of zerovalent iron (Fe0) that has been used in permeable react...

  9. Degradation Kinetics of Carbon Tetrachloride by Sulfate Green Rust as Influenced by pH and Copper Ions

    Science.gov (United States)

    Chlorinated solvents such as trichloroethene (TCE, C2HCl3) and carbon tetrachloride (CT, CCl4) are priority groundwater contaminants at many EPA field sites. Green rust (GR) minerals are important corrosion products of zerovalent iron (Fe0) that has been used in permeable reactiv...

  10. Charge Transfer Complex Role in the Formation of Chlorobenzene in the γ-Irradiated Carbon Tetrachloride - Benzene System

    International Nuclear Information System (INIS)

    The formation of carbon tetrachloride-benzene charge transfer complex was confirmed by UV and NMR spectrometric studies. A change in UV spectrum of benzene is observed upon addition of carbon tetrachloride. The appearance of new bands supports the formation of charge transfer complex. NMR study shows that benzene proton chemical shift depends on the CCI4-C6H6 molar ratio. This observation is another criterion for the formation of benzene - carbon tetrachloride charge transfer complex. Job's Continuous Variation method indicates that a 2:1 CCI4-C6H6 charge transfer complex(2:1 CTC) could be formed. The association constants (K2:1) of this 2:1 CTC was found to be 0.0197 M-2 .The maximum concentration of 2:1 CTC was found at about 33% benzene mole percent. The maximum yield of chlorobenzene was obtained, also, upon radiolysis of CCI4-C6H6 samples at 2:1 molar ratio (33% benzene mole percent). Therefore, it could be concluded that 2:1 CTC participates in thc formation of chlorobenzene upon radiolysis of benzene - carbon tetrachloride system.This conclusion was supported by the dependence of the chlorobenzene yield of γ-irradiated 2: 1 carbon tetrachloride - benzene system on irradiation time according to third order kinetic equation with a very good linearity (R2 = 0.9977). Accordingly, the rate constant for the chlorobenzene formation under this condition, was found to be ∼ 5.5 x 10-7 L2 .moI-2.h-1. We propose a radiation chemical mechanism in which the 2: 1 CTC plays a role in the formation of chlorobenzene

  11. 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.

  12. The atmospheric partial lifetime of carbon tetrachloride with respect to the global soil sink

    Science.gov (United States)

    Rhew, Robert C.; Happell, James D.

    2016-03-01

    The magnitude of the terrestrial soil sink for atmospheric carbon tetrachloride (CCl4) remains poorly constrained, with the estimated uncertainty range of CCl4 partial lifetimes between ~110 and 910 years. Field observations are sparse, and there are uncertainties in extrapolating these results to the global scale. Here we add to the published CCl4 fluxes with additional field measurements, and we employ a land cover classification scheme based on Advanced Very High Resolution Radiometer measurements that align more closely with the measurement sites to reevaluate the global CCl4 soil sink. We calculate an updated partial lifetime of CCl4 with respect to the soil sink to be 375 (288-536) years, which is 50 to 90% longer than the most recently published best estimates of the soil sink partial lifetime (195 and 245 years). This translates into a longer overall atmospheric lifetime estimate, which is more consistent with the observed atmospheric concentration trend and interhemispheric gradient.

  13. Abiotic Degradation Rates for Carbon Tetrachloride and Chloroform: Progress in FY2009

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-31

    This report documents the progress made through FY 2009 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 study seeks also to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. In previous years the work was funded as two separate projects by various sponsors, all of whom received their funding from the U.S. Department of Energy (DOE). In FY2009, the projects were combined and funded by CH2MHill Plateau Remediation Corporation (CHPRC). Work in FY2009 was performed by staff at the Pacific Northwest National Laboratory (PNNL). Staff from the State University of New York at Cortland (SUNY–Cortland) contributed in previous years.

  14. Carbon Tetrachloride and Chloroform Attenuation Parameter Studies: Heterogeneous Hydrolytic Reactions -- Status Report

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-18

    This report documents 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 study sought also to explore the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. It was funded by the U.S. Department of Energy (DOE) through the Office of Environmental Management Columbia River Protection Supplemental Technologies (CRPST) project and complements work initiated by the Hanford Groundwater Project in FY 2006 that focused primarily on CT in homogenous solution. Work was performed by staff at the Pacific Northwest National Laboratory (PNNL) and the State University of New York at Cortland (SUNY-Cortland).

  15. One-electron oxidation in irradiated carbon tetrachloride solutions of ZnTPP, TMPD, and phenols

    International Nuclear Information System (INIS)

    One-electron oxidation of phenol, p-methoxphenol, N,N,N',N'-tetramethyl-p-phenylenediamine, chlorpromazine, and zinc tetraphenolporphyrin (ZnTPP) was studied by pulse radiolysis in carbon tetrachloride solutions. Phenols form phenoxyl radicals and the other compounds form cation radicals with yields strongly dependent on solute concentration. The highest yield in deoxygenated solutions approached G = 4. In the presence of oxygen an additional oxidation step is observed owing to CCl3O2 radicals and the overall oxidation yield approached G = 8. ZnTPP was found to be oxidized to the cation radical without any side effects, unlike oxidation in 1,2-dichloroethane which was accompanied by demetallation owing to HCl production

  16. Irradiation of poly(vinyl alcohol) fibers in the presence of chloroform and carbon tetrachloride

    International Nuclear Information System (INIS)

    Radiolysis of poly(vinyl alcohol) fibers (PVA) in the presence of chloroform and carbon tetrachloride was investigated. Decrease in intrinsic viscosity was observed at lower dosages (up to 2.3 megarads); and above this, an increase was noted. The blank samples irradiated under similar conditions showed a continuous decrease in intrinsic viscosity. A discoloration in the samples irradiated in the presence of CCl4 and CHCl3 was also observed. It is attributed to double bond formation in the backbone. A marginal decrease in the tensile strength of the irradiated fibers was observed. However, the surface characteristics of the fibers did not change on irradiation. The thermogravimetric analysis revealed a better heat resistance in irradiated fibers

  17. 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

  18. Constraining the carbon tetrachloride (CCl4) budget using its global trend and inter-hemispheric gradient

    Science.gov (United States)

    Liang, Qing; Newman, Paul A.; Daniel, John S.; Reimann, Stefan; Hall, Bradley D.; Dutton, Geoff; Kuijpers, Lambert J. M.

    2014-07-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance and greenhouse gas and has been regulated under the Montreal Protocol. However, the near-zero 2007-2012 emissions estimate based on the UNEP reported production and feedstock usage cannot be reconciled with the observed slow decline of atmospheric concentrations and the inter-hemispheric gradient (IHG) for CCl4. Our 3-D model simulations suggest that the observed IHG (1.5 ± 0.2 ppt for 2000-2012) is primarily caused by ongoing current emissions, while ocean and soil losses and stratosphere-troposphere exchange together contribute a small negative gradient (~0 - -0.3 ppt). Using the observed CCl4 global trend and IHG, we deduce that the mean global emissions for the 2000-2012 period are 393445 Gg/yr (~30% of the peak 1980s emissions) and a corresponding total lifetime of 353732 years.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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....

  5. Hepatic ultrasonographic findings in experimental carbon tetrachloride intoxication of the dog.

    Science.gov (United States)

    Vörös, K; Albert, M; Vetési, F; Harmat, G y; Binder, K; Szaniszló, F

    1997-01-01

    An experimental study was undertaken in dogs with carbon tetrachloride (CCl4) intoxication to describe and follow the changes in the ultrasound appearance of the liver. Characteristic ultrasound features (enlarged liver, increased echogenicity with fine, tightly-packed echoes, and loss of echogenicity of the portal vein walls) were seen from day 2 of the experiment, culminating between days 2 and 7. Subsequently the liver gradually and almost completely regained its normal ultrasound appearance. Ultrasonographic findings corresponded to the severity of the clinicopathological parameters, and changed parallel with the results of liver biopsies. Histology of the biopsy samples revealed acute centrolobular lipid accumulation with necrobiosis and necrosis in the hepatocytes in the first stage of the disease. In the second stage, a secondary reparatory-inflammatory process and reparation in the interstitial tissue were seen. In some dogs, ill-defined hyperechoic foci were observed within the liver during the regenerative phase. Hepatic ultrasonography seems to be a reliable and relatively sensitive method for monitoring liver dystrophy with necrobiosis and lipid accumulation and to follow the course of steatosis in clinical cases. Ultrasound-guided biopsy can further improve the diagnostic accuracy of ultrasonography in liver dystrophy. PMID:9270137

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

    Energy Technology Data Exchange (ETDEWEB)

    Mallouk, Thomas E.

    2000-09-01

    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.

  7. 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.

  8. Effects of ethanol and carbon tetrachloride upon vitamin A status of rats

    International Nuclear Information System (INIS)

    The effects of ethanol (ET) and carbon tetrachloride (CCL4) upon tissue vitamin A, liver lipids, liver cytochrome P450 and hepatic morphology were investigated. After a two week feeding period, young male rats were divided into four groups. For 5 weeks one group of rats (n=18) received ET in liquid diets (30% of calories) while another (n=8) was exposed to CCL4 inhalation twice a week along with phenobarbitol in the diet. All groups received the NRC recommended level for vitamin A. Comparison of ET and its pair-fed control group revealed; decreased hepatic vitamin A, no change in serum vitamin A, increased % liver lipid and cytochrome P450 with minimal fat accumulation in hepatocytes. Comparison of CCL4 group with pair-fed controls showed; increased serum vitamin A, decreased hepatic vitamin A, increased cytochrome P450, marked hepatic fat accumulation, hepatic cell necrosis and early cirrhosis. Thus, CCL4, which is a more potent hepatotoxin as evidenced by a more elevated cytochrome P450 and distorted liver morphology, not only reduced liver vitamin A, but also increased serum vitamin A. The hepatic response to CCL4 may mimic a more cirrhotic condition such as that resulting from longer-termed ET intake

  9. Abiotic Degradation Rates for Carbon Tetrachloride and Chloroform: Progress in FY 2010

    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.

    2010-12-08

    This report documents the progress made through FY 2010 on a project initiated in FY 2006 to help address uncertainties related to the rates of hydrolysis in groundwater at the Hanford Site for carbon tetrachloride (CT) and chloroform (CF). The study also explores the possible effects of contact with minerals and sediment (i.e., heterogeneous hydrolysis) on these rates. The research was initiated to decrease the uncertainties in abiotic degradation rates of CT and chloroform CF associated with temperature and possible heterogeneous effects. After 2 years of data collection, the first evidence for heterogeneous effects was identified for hydrolysis of CT, and preliminary evidence for the effects of different mineral types on CF hydrolysis rates also was reported. The CT data showed no difference among mineral types, whereas significant differences were seen in the CF results, perhaps due to the fact that CF hydrolyzes by both neutral and base-catalyzed mechanisms whereas CT follows only the neutral hydrolysis path. In this report, we review the project objectives, organization, and technical approaches taken, update the status and results of the hydrolysis-rate experiments after 4 years of experimentation (i.e., through FY 2010), and provide a brief discussion of how these results add to scientific understanding of the behavior of the CT/CF plume at the Hanford Site.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Interleukin-6 production by peritoneal mesothelial cells and its regulation by inflammatory factors in rats administered carbon tetrachloride intraperitoneally

    International Nuclear Information System (INIS)

    We previously reported that a high level of interleukin-6 (IL-6), which is protective against CCl4-induced hepatotoxicity, is produced in the peritoneal cavity in the early period after ip carbon tetrachloride (CCl4) administration. The objective of this study was to identify the tissues and cells involved in IL-6 production and clarify the mechanisms underlying its regulation. IL-6 mRNA levels increased significantly in the serous membranes of the mesentery and peritoneum, but not in the parenchymal organs including liver, kidney and spleen, 3 h after ip CCl4 administration. Peritoneal mesothelial cells (PMCs), a major cell population in serous membranes, were isolated from rat peritoneal walls by trypsin digestion and cultured with peritoneal exudate fluid (PEF) from CCl4-administered rats. PMCs produced a high level of IL-6 in the presence of PEF recovered 0.5 h after ip CCl4 administration. Analyses of PEF revealed that the levels of prostaglandin E2 (PGE2), histamine, IL-1α, IL-1β and tumor necrosis factor-α (TNF-α) increased immediately after ip CCl4 administration. These inflammatory factors, except for histamine, stimulated IL-6 production to varying degrees, in the following order: IL-1α > IL-1β > TNF-α >> PGE2. In summary, the present study indicates that the high level of IL-6 observed in the rat peritoneal cavity after ip CCl4 administration is at least partially produced by PMCs stimulated cooperatively with IL-1α, IL-1β, TNF-α and PGE2. These inflammatory factors may be released from tissues or cells either stimulated or injured directly by CCl4

  19. 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.

  20. 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

  1. 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.

  2. 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...

  3. 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.

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

    International Nuclear Information System (INIS)

    Highlights: • We explored the underlying toxicology of CCl4 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. • CCl4 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 (CCl4)-induced hepatotoxicity in fish was investigated by studying the effects of CCl4 on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl4 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 CCl4 at 8 mM. The results showed that CCl4 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, CCl4 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 CCl4-induced hepatotoxicity in fish

  5. Carbon Tetrachloride (CCl4) in the Atmosphere: A Mystery Between Sources and Sinks

    Science.gov (United States)

    Reimann, S.; Newman, P. A.; Liang, Q.; Rigby, M. L.; Kuijpers, L.

    2013-12-01

    Carbon tetrachloride (CCl4) is an ozone depleting substance and therefore has been banned from usage under the Montreal Protocol. However, it is still allowed for contained use in industrial processes as so-called feedstock substance, where emissions should be negligible. The regulation of CCl4 in the Montreal Protocol suggests that, presently, emission should be zero, and that CCl4 ought to be declining exponentially depending on its atmospheric lifetime. Although atmospheric CCl4 concentrations are declining, the rate is slower than expected, suggesting that there is an unknown source of CCl4 or that the combined partial lifetimes in different environmental compartments (atmosphere, ocean, soil) are slower than our understood processes. In the last years there were increasing discrepancies between emissions reported under the Montreal Protocol ('bottom-up method') and those which are inferred from measurements at global background sites ('top-down method'). In 2012 the potential gap in global emissions between the two methods widened to several ten thousand tons per year. In order to close this gap several possibilities were tested with atmospheric models and results are verified against the global trends and the interhemispheric gradients. 1) Existing data from sources and sinks were fed into the models to test the incompatibility of the existing emission data with the observed atmospheric observation for CCl4. 2) A newly revised 44-year steady-state atmospheric lifetime was assessed. This new lifetime together with an improved uncertainty has been carefully evaluated within a lifetime assessment for ODSs and related substances under SPARC (Stratosphere-troposphere Processes And their Role in Climate). The new atmospheric lifetime is substantially longer than the 35-years which were used in WMO (2011) for the atmosphere alone. However, estimates of soil sinks (195 yr) and ocean sinks (81 yr) lead to a best-estimated global lifetime of only 25 years, comparable

  6. 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

  7. Solving the carbon tetrachloride (CCl4) budget mystery using surface observations

    Science.gov (United States)

    Liang, Q.; Newman, P. A.; Daniel, J. S.; Reimann, S.; Hall, B. D.; Dutton, G. S.; Kuijpers, L. J. M.

    2014-12-01

    Carbon tetrachloride (CCl4) is a major anthropogenic ozone-depleting substance, with an ozone depletion potential (with respect to CFC-11) of 0.82. CCl4 is also a greenhouse gas and the 100-yr global warming potential is 1,400. In 1987, the Montreal Protocol (MP) included CCl4, and production and consumption were phased out for developed countries in 1996. Developing countries were allowed a delayed reduction, but CCl4 was fully phased out from emissive uses in 2010. However, the near-zero 2007-2012 emissions estimate based on the UNEP reported production and feedstock usage cannot be reconciled with the observed slow decline of atmospheric concentrations, year-to-year variability, and the inter-hemispheric gradient (IHG). We use available source and sink data in the NASA 3-Dimensional (3-D) Chemistry Climate Model, GEOSCCM, to test existing emissions and lifetime estimates against CCl4 mixing ratio observations. Our model results show that the IHG and global trend provide useful information for quantitatively constraining CCl4 emissions and lifetime estimates. The observed IHG (1.5±0.2 ppt for 2000-2012) is primarily caused by ongoing current emissions, while ocean and soil losses and stratosphere-troposphere exchange together contribute a small negative gradient (~0 - -0.3 ppt). Using the observed CCl4 global trend and IHG from the National Oceanic and Atmospheric Administration - Global Monitoring Division (NOAA-GMD) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks, we deduce the mean global emissions for the 2000-2012 period are 39 (34-45, lower-upper limit emission estimates) Gg/yr (~ 30% of the peak 1980s emissions) and a corresponding total lifetime of 35 (37-32, upper-lower limit lifetime estimates) years. These results point to the need for a more accurate bottom-up estimate of CCl4 emissions as well as re-evaluation of the CCl4 best estimate lifetime (currently 25 years).

  8. Kadar Perasan Kunyit yang Efektif Memperbaiki Kerusakan Hati Mencit yang Dipicu Karbon Tetrachlorida (THE EFFICACY OF TURMERIC JUICE ON PATHOLOGICAL CHANGES OF THE MICE LIVER BY INDUCED CARBON TETRACHLORIDE

    Directory of Open Access Journals (Sweden)

    I Made Kardena

    2012-03-01

    Full Text Available A study on effect of various concentrations of turmeric juice on pathological changes mice liver hasbeen carried out. As many as 25 mice were used in this study and they were divided into 5 groups, i.e.: groupK-: 0.2 ml vegetable oil without CCl4; group K+: CCl4 without turmeric extract; group T1: CCl4 with 10%turmeric extract; group T2: CCl4 with 20% turmeric extract and group T3: CCl4 with 30% turmeric extract.All mice, except the K- group, were treated with 0.2 ml CCl4 orally for 7 days. On day-8 to day-29, the CCl4treated mice were given various concentrations of turmeric extract, i.e.: 10%, 20% and 30%; whereas, the KandK+ groups were given drinking water adlibitum. On day-30, all mice were sacrificed and their livertissues were collected and then processed to histopathological staining with haematoxylin-eosin. Theresult showed a clear evidence to suggest that turmeric extract can induce a better recovery compared tonon-treated mice. The improvement of pathological condition was characterized by reduction of pathologicalchanges found in the liver cells of mice, such as: hidrophic degeneration. fatty degeneration, and necrosis.More importantly, treatment with 30% of turmeric juice induced a better recovery than those with 10%and 20%.

  9. Pulse radiolysis of porphyrin and ferriporphyrin solutions in 2-propanol-carbon tetrachloride systems. Protonation and ligand exchange kinetics

    International Nuclear Information System (INIS)

    Pulse radiolysis of aqueous and nonaqueous 2-propanol-acetone-carbon tetrachloride mixtures has been investigated by means of conductivity measurements and spectrophotometry. In these solvent mixtures, a pulse of hydrochloric acid originating from either primary events of solvent radiolysis or from further reactions of carbon tetrachloride with radicals derived from 2-propanol and acetone, is produced within ca 100 nanoseconds. Further production of hydrochloric acid occurs as a result of chain reactions involving hydrogen abstraction by CCl3 or CCl3O2 radicals. These latter radicals appear to be much more reactive and are likely to be involved in the reaction unless the solutions have been thoroughly deoxygenated. Protonation Reactions of porphyrins and ferriporphyrins, which do not react rapidly with the above radicals, were followed by means of spectrophotometric measurements. In turn, these reactions may be used to monitor hydrochloric acid formation. Spectrophotometric measurements on porphyrins corroborate conductivity results, although a quantitative comparison is not feasible because of differences in solvent properties. 6 figures

  10. 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...

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

    International Nuclear Information System (INIS)

    Highlights: • CCl4 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. • CCl4 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

  12. EFFECT OF GAVAGE VEHICLE ON HEPATOTOXICITY OF CARBON TETRACHLORIDE IN CD-1 MICE: CORN OIL VERSUS TWEEN-60 AQUEOUS EMULSION (JOURNAL VERSION)

    Science.gov (United States)

    The investigation was conducted to evaluate the effect of corn oil gavage on the subchronic hepatotoxicity of carbon tetrachloride (CCl(4)). Male and female CD-1 mice were gavaged with 0, 1.2, 12, and 120 mg/kg CCl(4) in either corn oil or 1% Tween-60 vehicles once daily for five...

  13. Overcoming Barriers to the Remediation of Carbon Tetrachloride Through Manipulation of Competing Reaction Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Tratnyek, Paul G.

    2003-06-01

    Quantify the kinetics of all competing product-formation pathways, over a range of conditions relevant to groundwater remediation, using well-mixed batch reactors and analysis primarily by chromatography. At OGI, batch experiments were conducted on Fe(0) systems (both Fisher Electrolytic and Nano-sized iron). The experiments were done with and without buffer. The buffered experiments tried to contrast two buffers: an organic buffer (EPPS, presumably a H atom donor), and the inorganic borate. In the buffered experiments, the pH was varied (7.3 and 8.4). For the pre-exposure treatment, after trying a variety of methods, like shaking and not shaking for varied amounts of time, it was decided to stick with not shaking and have a pre-exposure of 24 hours. The unbuffered data did not show any marked trend with increasing mass of Felc. However, 3.5 g of Fe showed about 100% conversion to CHCl3, and 1g of Fe showed 50% conversion. At pHs 8.4 and 7.3, there was no trend observed for branching ratios between EPPS and Borate buffer. kCT (disappearance rate constant of carbon tetrachloride) values were found to be different from CT and CF fits. Experiments with nano-iron (unbuffered, buffered with both buffers at pH 8.3), did not show any trend with respect to Fisher Iron, except for the unbuffered experiments, where the CF ''yield'' was less in the nano iron case. Future experiments involve testing for chloride, formate and CO, and performing experiments over a wider range of pH and buffers. Batch experiments were conducted at PNNL to compare the efficiency and product distribution of representative Fe(II) and Fe(0) systems applied to dechlorination of CCl4. These experiments involved (1) a smectite clay with Fe(III) in its structure that had been reduced to Fe(II) by dithionite treatment, (2) the same clay to which Fe(II) was added as an exchangeable cation, (3) electrolytic Fe(0) from Fisher, and (4) a mixture of the reduced clay and Fe(0). Experiments

  14. 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

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.)

  20. 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.)

  1. 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

  2. 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).

  3. Carbon tetrachloride contamination, 200 West Area, Hanford Site: Arid Site Integrated Demonstration for remediation of volatile organic compounds

    International Nuclear Information System (INIS)

    The Arid State Integrated Demonstration is a US Department of Energy (DOE) program targeted at the acquisition, development, demonstration, and deployment of technologies for evaluation and cleanup of volatile organic and associated contaminants in soils and ground waters. Several DOE laboratories, universities, and industry will participate in the program. Candidate technologies will be demonstrated in the areas of site characterization; performance prediction, monitoring, and evaluations; contaminant extraction and ex situ treatment; in situ remediations; and site closure and monitoring. The performance of these demonstrated technologies will be compared to baseline technologies and documented to promote the transfer of new technologies to industry for use at DOE facilities. The initial host site is the Hanford Site's 200 West Area. The location of the demonstration contains primarily carbon tetrachloride (CCl4), chloroform, and a variety of associated mixed waste contaminants. Chemical processes used to recover and purify plutonium at Hanford's plutonium finishing plant (Z Plant) resulted in the production of actinide-bearing waste liquid. Both aqueous and organic liquid wastes were generated, and were routinely discharged to subsurface disposal facilities. The primary radionuclide in the waste streams was plutonium, and the primary organic was CCl4. This paper contains brief descriptions of the principal CCl4 waste disposal facilities in Hanford's 200 West Area, associated hydrogeology, existing information on the extent of soil and ground-water contamination, and a conceptual outline of suspected subsurface CCl4 distributions

  4. Reactions of Hot Cl38 Atoms in Mixtures of Carbon Tetrachloride with Aliphatic Alcohols

    International Nuclear Information System (INIS)

    Investigations of the chemical effects of nuclear reactions in binary systems are expected to yield much useful information. Study of the recoil processes of the halogen derivatives when the second component is suitably chosen and its concentration varied in a wide range might permit inferences to be made on the role and mechanism of the various stabilizing processes. Considering the results obtained with CCl4-Cl2, CCl4-SiCl4, CCl4-C6H6 and CCl4-c-hexane mixtures as well as the energy scavenger property of alcohol, it seemed of interest to study the contribution of the alcohols to the stabilization of hot Cl38. Chemical processes induced by hot Cl38 from the nuclear reaction Cl97 (n, γ)Cl38 were investigated in mixtures of CCl4-ROH (where R = CH3-, C2H5-, C3H7- and (CH3)2CH-). The irradiations were performed in the thermal column of the 2 MW VVRS reactor using rather short exposure times to keep the radiation chemical effects at negligible level. The organic fractions were separated from the inorganic ones by extraction and the former were analysed by gas chromatographic method. Total retention and the yield of the complete set of organic chlorine compounds were determined in terms of alcohol concentration. Some interesting results are that the yield of reaction products in which the OH radical of aliphatic alcohol has been replaced by Cl38 increases with increasing alcohol concentration with a simultaneous decrease in the labelled CCI4 yield and that, in addition to the monochlorine derivates with less carbon atoms than the alcohol molecule, a considerable amount of chloroform is formed with maximum yield at a given alcohol concentration. The relative contributions of the hot and the epithermal stabilization processes of energetic Cl38 and the mechanism of the various reactions are discussed. (author)

  5. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. Carbon Tetrachloride Increases the Pro-inflammatory Cytokines Levels in Different Brain Areas of Wistar Rats: The Protective Effect of Acai Frozen Pulp.

    Science.gov (United States)

    de Souza Machado, Fernanda; Marinho, Jéssica Pereira; Abujamra, Ana Lúcia; Dani, Caroline; Quincozes-Santos, André; Funchal, Cláudia

    2015-09-01

    Acai offers health benefits associated with its high antioxidante capacity, phytochemical composition, nutritional and sensory value. Therefore, the objective of this study was to evaluate the protective effect of acai frozen pulp on carbon tetrachloride (CCl4)-induced damage via modulation of anti- and pro-inflammatory cytokines in rat brain tissue. The rats were treated via oral (gavage) daily with water or acai frozen pulp for 14 days at a dose of 7 μL/g. On the 15th day, the animals in each group received a single intraperitoneal injection of CCl4 in a dose of 3.0 mL/kg or the same volume of mineral oil. After 4 h, the animals were euthanized by decapitation and the cerebral cortex, hippocampus and cerebellum were dissected and homogenated to evaluate the levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), interleukin 18 (IL-18), interleukin 6 (IL-6) and interleukin 10 (IL-10). Data were statistically analyzed by analysis of variance followed by the Tukey post hoc test. It was observed that CCl4 increased TNF-α, IL-1β and IL-18 levels in all brain tissues, and that acai frozen pulp was able to prevent this increase. IL-6 and IL-10 brain tissue levels remained unchanged during all treatments. CCl4 experimental model was suitable to investigate brain tissue anti and pro-inflammatory cytokines. Acai frozen pulp prevented an increase in IL-1β, IL-18 and TNF-α, while IL-6 and IL-10 levels remained unchanged. The precise pathway by which inflammation contribute to hepatic encephalopathy, as well as to how this pathway can be modulated, is still under investigation. PMID:26283513

  12. 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.

  13. Hepatoprotective effects of polymethoxyflavones against acute and chronic carbon tetrachloride intoxication.

    Science.gov (United States)

    Kim, Tae-Won; Lee, Dong-Ryung; Choi, Bong-Keun; Kang, Hwan-Kyu; Jung, Ju-Young; Lim, Seol-Wa; Yang, Seung Hwan; Suh, Joo-Won

    2016-05-01

    In the present study, we explore the protective effects of Citrus aurantium L. extract (CAE) against acute and chronic CCl4-induced hepatotoxicity. The quantitative analysis of CAE was performed using HPLC-UV to determine the nobiletin content was approximately 27%. For the acute model, the male ICR mice were orally treated with water, silymarin (positive control, 200 mg/kg) and CAE (50 and 200 mg/kg) for 3 days prior to CCl4 (1 mL/kg, 50% v/v in olive oil) IP injection. For the chronic model (n = 6/group), the mice were treated with each treatment for 28 consecutive days and CCl4 (1 mL/kg, 20%) was injected twice a week. In both the acute and chronic models, the CCl4 alone treated group showed histopathologic alterations with a significantly increase in serum hepatic enzyme levels together with a disrupted anti-oxidative status. In contrast, the CAE treatments restored pathologic alterations and recovered the oxidative status by enhancing antioxidant enzymes and reducing lipid peroxidation levels. Furthermore, CAE enhanced nuclear factor E2-related factor 2 (Nrf2) and its related cytoprotective signals, including NAD(P)H quinone oxidoreductase 1, UDP-glucuronosyltransferase, and γ-glutamylcysteine synthetase. Taken together, the present study demonstrates that CAE exerts a protective effect against CCl4-induced hepatotoxicity with its anti-oxidant, anti-inflammatory, and anti-apoptotic activity. PMID:26980244

  14. DIURNAL RHYTHM OF CARBON TETRACHLORIDE HEPATOTOXICITY IF A LIGHT SYNCHRONIZER IS CHANGED UNNATURALLY

    Directory of Open Access Journals (Sweden)

    Vysotskiy I. Yu.

    2013-07-01

    Full Text Available The experiments were carried out on 72 white male rodents weighing 150-220 g with ad libitum diet during the light and dark periods. These periods were striped in the ratio of 12:12. The toxic damage of liver was caused during the various day periods (at 6am, 10am, 2pm, 6pm, 10pm and 2am by the intramuscular injection of CCl4 solution at a dose of 0.5 ml per 100 g body weight. The samples were gathered in 24 hours after the injection of CCl4. It was pointed that the most significant hepatotoxic influence of CCl4 was at 6pm and 10pm. Perhaps, it is connected to large amount of enzymes contained in the membrane, such as cytochrome P450-3A–reductase and succinate dehydrogenase. The low level of diene conjugates was observed during this period of time, which was the evidence for more serious damages and disruption of the endoplasmic reticulum membranes. Later these membranes were slightly able to metabolize CCl4 to active radicals, which normally induce lipid peroxidation. The significant increase of malondialdehyde level was measured on a background of these conditions. It can be considered as the result of antioxidant system activity exhaustion.

  15. 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

  16. 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...

  17. 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.

  18. 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

  19. 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.

  20. 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

    2016-03-15

    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. PMID:26722673

  1. 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

  2. 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.

  3. 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 ...

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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).

  16. 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

  17. Hafnium tetrachloride adducts with aminophenols

    International Nuclear Information System (INIS)

    Adducts of hafnium tetrachloride with aminophenols of a general composition of HfCl4x4L have been obtained by addition of ethyl acetate solutions of hafnium tetrachloride with solutions of o-aminophenol in dioxan, m-aminophenol in ethyl acetate and n-aminophenol in dioxan at a ratio Hf/L=1/2. In the investigated adducts, aminophenols are connected to hafnium both through an oxygen atom and a nitrogen atom, the latter's coordination being preferable. A thermal investigation of synthesized complexes has determined the quantity of heat evolving on addition of 4 moles of aminophenol to 1 mole of crystalline hafnium tetrachloride

  18. 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.

  19. 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.

  20. Chlorobenzene, chloroform, and carbon tetrachloride adsorption on undoped and metal-doped sol-gel substrates (SiO2, Ag/SiO2, Cu/SiO2 and Fe/SiO2)

    International Nuclear Information System (INIS)

    Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO2, and metal-doped Ag/SiO2, Cu/SiO2 and Fe/SiO2 substrates were measured in the temperature range of 398-593 K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO2 materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO2 samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption

  1. 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.

  2. Effect of sublethal (5, 15, 40, 150, 400 R) whole-body x irradiation on collagen metabolism in the liver manifest as a subnormal response to subsequent carbon tetrachloride injury

    International Nuclear Information System (INIS)

    The effect of sublethal, whole body x-irradiation on the induction of synthesis and the maturation of hepatic collagen was studied. The findings of this study support suggestions made by others that problems in wound healing observed in x-irradiated subjects can be traced in part to defects in collagen metabolism. The model employed was that of acute carbon tetrachloride (CCl4) poisoning of mouse liver. This model was chosen instead of the more conventional skin wounding technique because of its relative ease of application, the uniformity of response, and the ability to clearly define the limits of assay. The fibrotic response of liver to CCl4 was studied 1, 3 and 6 weeks following irradiation (0, 5, 15, 40, 150 or 400 R) and three days after the administration of CCl2. The significance of this work rests with the fact that an alteration of collagen synthesis was demonstrated under CCl4 stress following exposure to a dose as low as 150 R. This x-ray effect was expressed as a reduction in prolyl hydroxylase activity, a key enzyme in the biosynthesis of collagen. Previously, such an effect has only been demonstrated indirectly and with higher doses of radiation, e.g. 1500 R. Further, this sublethal injury was found to require more than 1 week for repair as opposed to 1 hour for the repair of classical sublethal radiation damage. These findings indicate that impaired wound healing observed following x-irradiation may be linked to defects in collagen metabolism and that these defects may remain for more extended periods and result from lower x-ray doses than previously reported

  3. Chlorobenzene, chloroform, and carbon tetrachloride adsorption on undoped and metal-doped sol-gel substrates (SiO{sub 2}, Ag/SiO{sub 2}, Cu/SiO{sub 2} and Fe/SiO{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, M.A. [Postgrado de Ciencias Ambientales and Departamento de Investigacion en Zeolitas, Instituto de Ciencias, Universidad Autonoma de Puebla, Edificio 76, Complejo de Ciencias, Ciudad Universitaria, CP 72570 Puebla (Mexico)], E-mail: mighern@siu.buap.mx; Gonzalez, A.I.; Corona, L.; Hernandez, F. [Postgrado de Ciencias Ambientales and Departamento de Investigacion en Zeolitas, Instituto de Ciencias, Universidad Autonoma de Puebla, Edificio 76, Complejo de Ciencias, Ciudad Universitaria, CP 72570 Puebla (Mexico); Rojas, F.; Asomoza, M.; Solis, S. [Departamento de Quimica, Universidad Autonoma Metropolitana-Iztapalapa, P.O. Box 55-534, D.F. Mexico (Mexico); Portillo, R.; Salgado, M.A. [Facultad de Ciencias Quimicas, Universidad Autonoma de Puebla (Mexico)

    2009-02-15

    Adsorption isotherms of chlorobenzene, chloroform and carbon tetrachloride vapors on undoped SiO{sub 2}, and metal-doped Ag/SiO{sub 2}, Cu/SiO{sub 2} and Fe/SiO{sub 2} substrates were measured in the temperature range of 398-593 K. These substrates were prepared from a typical sol-gel technique in the presence of metal dopants that rendered an assortment of microporous-mesoporous solids. The relevant characteristic of these materials was the different porosities and micropore to mesopore volume ratios that were displayed; this was due to the effect that the cationic metal valence exerts on the size of the sol-gel globules that compose the porous solid. The texture of these SiO{sub 2} materials was analyzed by X-ray diffraction (XRD), FTIR, and diverse adsorption methods. The pore-size distributions of the adsorbents confirmed the existence of mesopores and supermicropores, while ultramicropores were absent. The Freundlich adsorption model approximately fitted the chlorinated compounds adsorption data on the silica substrates by reason of a heterogeneous energy distribution of adsorption sites. The intensity of the interaction between these organic vapors and the surface of the SiO{sub 2} samples was analyzed through evaluation of the isosteric heat of adsorption and standard adsorption energy; from these last results it was evident that the presence of metal species within the silica structure greatly affected the values of both the amounts adsorbed as well as of the isosteric heats of adsorption.

  4. Sympathetic Nervous System Control of Carbon Tetrachloride-Induced Oxidative Stress in Liver through α-Adrenergic Signaling

    OpenAIRE

    Jung-Chun Lin; Yi-Jen Peng; Shih-Yu Wang; Mei-Ju Lai; Ton-Ho Young; Salter, Donald M.; Herng-Sheng Lee

    2015-01-01

    In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS) in m...

  5. Sympathetic Nervous System Control of Carbon Tetrachloride-Induced Oxidative Stress in Liver through a-Adrenergic Signaling

    OpenAIRE

    Lin, Jung-Chun; Peng, Yi-Jen; Wang, Shih-Yu; Lai, Mei-Ju; Young, Ton-Ho; Salter, Donald; Lee, Herng-Sheng

    2016-01-01

    In addition to being the primary organ involved in redox cycling, the liver is one of the most highly innervated tissues in mammals. The interaction between hepatocytes and sympathetic, parasympathetic, and peptidergic nerve fibers through a variety of neurotransmitters and signaling pathways is recognized as being important in the regulation of hepatocyte function, liver regeneration, and hepatic fibrosis. However, less is known regarding the role of the sympathetic nervous system (SNS) in m...

  6. 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...

  7. 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.

  8. Drought-induced carbon loss in peatlands

    Science.gov (United States)

    Fenner, Nathalie; Freeman, Chris

    2011-12-01

    Peatlands store vast amounts of organic carbon, amounting to approximately 455 Pg. Carbon builds up in these water-saturated environments owing to the presence of phenolic compounds--which inhibit microbial activity and therefore prevent the breakdown of organic matter. Anoxic conditions limit the activity of phenol oxidase, the enzyme responsible for the breakdown of phenolic compounds. Droughts introduce oxygen into these systems, and the frequency of these events is rising. Here, we combine in vitro manipulations, mesocosm experiments and field observations to examine the impact of drought on peatland carbon loss. We show that drought stimulates bacterial growth and phenol oxidase activity, resulting in a reduction in the concentration of phenolic compounds in peat. This further stimulates microbial growth, causing the breakdown of organic matter and the release of carbon dioxide in a biogeochemical cascade. We further show that re-wetting the peat accelerates carbon losses to the atmosphere and receiving waters, owing to drought-induced increases in nutrient and labile carbon levels, which raise pH and stimulate anaerobic decomposition. We suggest that severe drought, and subsequent re-wetting, could destabilize peatland carbon stocks; understanding this process could aid understanding of interactions between peatlands and other environmental trends, and lead to the development of strategies for increasing carbon stocks.

  9. 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.

  10. 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

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

    OpenAIRE

    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 abil...

  12. 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)

  13. Radiation induced effects in carbon materials

    International Nuclear Information System (INIS)

    Full text: The level of safe exploiting nuclear reactor depends on radiation-induced changes of the neutron-absorbing material shape. The dimensional effects in carbon materials including those containing boron carbides B4C, irradiated in the water-water cooled reactor of the INP AS RUz operating at the power of 10 MW were studied in the temperature interval of 300-1500 K up to the integral fluence of 4·1021 neutrons per cm2. Two methods of dimensional control were used: dilatometry (change of linear dimensions and calculation of the volume change) and X-ray diffraction analysis (determination of the lattice parameters and the elementary unit volume). In all samples of low-ash and pyrolytic graphite (oriented parallel and normal to the pressing axis), irradiated up to the fluences above 1021 n/cm2 in the temperature range of 700-1100 K the shrinkage of linear dimensions was found from 6 to 8 %. While there occurred the primary swelling of graphite in the temperature interval of 300-700 K. The secondary swelling began at the fluence of 4·1021 cm-2 and 1100 K. Basing on these data, the neutron-absorbing graphite rods, containing B4C particles, were tested under the analogous irradiation conditions. The comparison of the rates of B4C swelling and graphite matrix shrinkage showed, that unfortunately, there was not gained the complete compensation of the swelling at the expense of shrinkage. The samples of fiber graphite, which were studied under the same conditions as the above mentioned, turned out stable in dimensions - changes in linear dimensions did not exceed 2 %. The X-diffraction study of ultra disperse amorphous carbon film irradiated in the water reactor discovered the formation of a denser carbon phase. The position of the observed structure reflection with d/n = 7.5 A did not correspond to the peaks of stable single phases of fullerenes C60 and C70. Perhaps, the irradiation creates a mixture of these phases in the amorphous matrix

  14. 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

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. Induced nucleation of carbon dust in red giant stars

    Science.gov (United States)

    Cadwell, Brian J.; Wang, Hai; Feigelson, Eric D.; Frenklach, Michael

    1994-01-01

    This study quantitatively tests the proposed model of induced nucleation of carbonaceous grains in carbon-rich red giant stars. Induced nucleation is the process of grain growth initiated by the presence of reactive surfaces provided by seed particles. The numerical study was performed using a deailed chemical kinetic model of carbon deposition, grain coagulation, and homogeneous nucleation of polycyclic aromatic hydrocarbons (PAHs). The model uses a method of moments to keep track of developing grain population in the forming dust shell. We test the efficiency of grain formation for large ranges of dust shell parameters typical for carbon stars. Our model is capable of producing a range of optically thick and thin dust shells in carbon stars. Results are in accord with (IRAS) spectral classes of carbon stars. The resulting composite grains produced are consistent with those recently found in ancient meteorites. This model also provides a realistic explanation for high abundances of (PAHs) in the interstellar medium and some planetary nebulae.

  20. Role Of Shark Cartilage In Quenching The Oxidative Damage Induced By GAMMA Radiation And Carbon Tetrachloride In Liver Of Guinea Pig

    International Nuclear Information System (INIS)

    The study aimed to determine the effect of CCl4 and/or gamma radiation on Mn-SOD, Cu-Zn-SOD and GPx, nitric oxide NO stable end products (N2, N3, NOx), eNOS, iNOS RNA gene expression, gene expression of tumour necrotic factor (TNF-Α ) and immunohistochemistry of fibronectin (FN) in the liver of guinea pig that triggers cirrhosis and allows to obtain harmful physiological modifications. The study was also carried out to evaluate the role of shark cartilage (SC) as antioxidant to minimize the side effects of CCl4 . The results revealed significant increase in iNOS and TNF-gene expression, and significant decrease in Mn-SOD, Cu-Zn-SOD and GPx enzymes in liver tissues of guinea pig treated with CCl4 and/or gamma radiation. Moreover, the results demonstrated that SC can minimize the hazardous effects of CCl4 and gamma radiation on liver of guinea pig.

  1. 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

  2. Erosion-induced massive organic carbon burial and carbon emission in the Yellow River basin, China

    OpenAIRE

    Ran, L.; X. X. Lu; Z. Xin

    2013-01-01

    Soil erosion and terrestrial deposition of soil organic carbon (SOC) can potentially play a significant role in global carbon cycling. Assessing the fate of SOC during erosion and subsequent transport and sedimentation is of critical importance. Using hydrological records of soil erosion and sediment load, and compiled organic carbon (OC) data, budgets of the eroded soils and OC induced by water in the Yellow River basin during 1950–2010 were analyzed. The Yellow River basin has experi...

  3. 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

  4. 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)

  5. Mechanism of lithium carbonate induced hyperdipsia

    OpenAIRE

    Brime Casanueva, Juan Ignacio; López-Sela Melendez de Arvás, Purificacion; Argüelles Luis, Juan; Costales Pérez, Marina; Vijande Vázquez, Manuel

    1999-01-01

    Los pacientes psiquiátricos y los animales de laboratorio tratados con carbonato de litio desarrollan una importante poliuria y polidipsia. La polidipsia puede ser un fenómeno primario que induce una poliuria secundaria o alternativamente, una poliuria primaria podría ser la causa de la polidipsia observada. Nuestros experimentos utilizando ratas macho nefrectomizadas tratadas con litio, sugieren que la poliuria sea primaria y la polidipsia secundaria. Estos resultados se confirman cuando se ...

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. 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

  11. Zirconium tetrachloride production using the fluidized bed chlorination technique

    International Nuclear Information System (INIS)

    In this paper the results of a study of the process for production nuclear grade zirconium tetrachloride by fluidized bed chlorination technique are presented. A reactor with a gas distributor has been developed and this permitted to establish a procedure of zirconium tetrachloride production with adequate purity, satisfactories efficiency of reaction and reproducible results. Some relevant parameters of the kinetics of chlorination process such as: time and temperature of reaction, size and minimum fluidizing velocity of microspheres and percentage of the reducing agent have been studied. (author). 15 refs., 5 figs

  12. 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

  13. 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 ...

  14. 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.

  15. Damage to plasmid DNA induced by low energy carbon ions

    International Nuclear Information System (INIS)

    The damage induced in supercoiled plasmid DNA molecules by 1-6 keV carbon ions has been investigated as a function of ion exposure, energy and charge state. The production of short linear fragments through multiple double strand breaks has been demonstrated and exponential exposure responses for each of the topoisomers have been found. The cross section for the loss of supercoiling was calculated to be (2.2 ± 0.5) x 10-14 cm2 for 2 keV C+ ions. For singly charged carbon ions, increased damage was observed with increasing ion energy. In the case of 2 keV doubly charged ions, the damage was greater than for singly charged ions of the same energy. These observations demonstrate that ion induced damage is a function of both the kinetic and potential energies of the ion

  16. Th2-Associated Alternative Kupffer Cell Activation Promotes Liver Fibrosis without Inducing Local Inflammation

    Directory of Open Access Journals (Sweden)

    Giuliana López-Navarrete, Espiridión Ramos-Martínez, Karina Suárez-Álvarez, Jesús Aguirre-García, Yadira Ledezma-Soto, Sonia León-Cabrera, Marco Gudiño-Zayas, Carolina Guzmán, Gabriela Gutiérrez-Reyes

    2011-01-01

    Full Text Available Cirrhosis is the final outcome of liver fibrosis. Kupffer cell-mediated hepatic inflammation is considered to aggravate liver injury and fibrosis. Alternatively-activated macrophages are able to control chronic inflammatory events and trigger wound healing processes. Nevertheless, the role of alternative Kupffer cell activation in liver harm is largely unclear. Thus, we evaluated the participation of alternatively-activated Kupffer cells during liver inflammation and fibrosis in the murine model of carbon tetrachloride-induced hepatic damage. To stimulate alternative activation in Kupffer cells, 20 Taenia crassiceps (Tc larvae were inoculated into BALBc/AnN female mice. Six weeks post-inoculation, carbon tetrachloride or olive oil were orally administered to Tc-inoculated and non-inoculated mice twice per week during other six weeks. The initial exposure of animals to T. crassiceps resulted in high serum concentrations of IL-4 accompanied by a significant increase in the hepatic mRNA levels of Ym-1, with no alteration in iNOS expression. In response to carbon tetrachloride, recruitment of inflammatory cell populations into the hepatic parenchyma was 5-fold higher in non-inoculated animals than Tc-inoculated mice. In contrast, carbon tetrachloride-induced liver fibrosis was significantly less in non-inoculated animals than in the Tc-inoculated group. The latter showed elevated IL-4 serum levels and low IFN-γ concentrations during the whole experiment, associated with hepatic expression of IL-4, TGF-β, desmin and α-sma, as well as increased mRNA levels of Arg-1, Ym-1, FIZZ-1 and MMR in Kupffer cells. These results suggest that alternative Kupffer cell activation is favored in a Th2 microenvironment, whereby such liver resident macrophages could exhibit a dichotomic role during chronic hepatic damage, being involved in attenuation of the inflammatory response but at the same time exacerbation of liver fibrosis.

  17. Substrate effect on the enhanced biodegradation of carbon tetrachloride

    Science.gov (United States)

    Wu, Shian C.; Doong, Rueyan

    1993-03-01

    The effects of different substrates on the biotransformation of heavily chlorinated hydrocarbons under anaerobic conditions were investigated to evaluate the feasibility of in-situ bioremediation of the contaminated groundwaters by amending different substrates. The substrate-fed batches were anaerobically incubated with the addition of either acetate, glucose, methanol, or dissolved organic matter (DOM) with concentrations ranging from 10 to 30 mg/L. Experimental results demonstrated that the effect of the substrates on the dechlorination of the compounds varied. The removal efficiency was observed greatest for glucose- then methanol- and acetate-fed batches and least for DOM-fed batches. The sequence of the enhancement efficiency is consistent with the sequence of the reducing potentials of these substrates. Changing the substrate concentration could vary the dechlorination capability of the system. The viable counts of microorganisms determined by the direct epifluorescence counting technique showed that the batches with higher concentration of the supplemental substrate produced higher bacterial cell numbers. Moreover, from microscopic observations, different compositions of bacterial population were found. Small-sized bacteria with spheric shape were observed when culture bottles were amended with either acetate or DOM, whereas large-sized bacteria with rod-shape were predominant for bottles amended with glucose. Also, higher DNA contents were demonstrated for glucose-fed batches.

  18. Low-energy electron scattering by carbon tetrachloride

    Science.gov (United States)

    Moreira, Giseli M.; Souza Barbosa, Alessandra; Pastega, Diego F.; Bettega, Márcio H. F.

    2016-02-01

    In this work we report calculated integral and differential elastic cross sections for the scattering of low-energy electrons by CCl4. We employ the Schwinger multichannel method with pseudopotentials to compute the cross sections in the static-exchange and static-exchange plus polarization approximations for energies up to 15 eV. We report two shape resonances located at 0.75 eV and 8 eV belonging to the T 2 and E symmetries of the T d group respectively. We also look at the s-wave contribution to the integral cross section and find no evidence of the presence of a Ramsauer-Townsend minimum. We compare our calculated cross sections with available experimental and theoretical results and find that in general the agreement is good.

  19. 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.

  20. Femtosecond laser-induced surface structures on carbon fibers.

    Science.gov (United States)

    Sajzew, Roman; Schröder, Jan; Kunz, Clemens; Engel, Sebastian; Müller, Frank A; Gräf, Stephan

    2015-12-15

    The influence of different polarization states during the generation of periodic nanostructures on the surface of carbon fibers was investigated using a femtosecond laser with a pulse duration τ=300  fs, a wavelength λ=1025  nm, and a peak fluence F=4  J/cm². It was shown that linear polarization results in a well-aligned periodic pattern with different orders of magnitude concerning their period and an alignment parallel and perpendicular to fiber direction, respectively. For circular polarization, both types of uniform laser-induced periodic surface structures (LIPSS) patterns appear simultaneously with different dominance in dependence on the position at the fiber surface. Their orientation was explained by the polarization-dependent absorptivity and the geometrical anisotropy of the carbon fibers. PMID:26670499

  1. Dislocation core reconstruction induced by carbon segregation in bcc iron

    Science.gov (United States)

    Ventelon, Lisa; Lüthi, B.; Clouet, E.; Proville, L.; Legrand, B.; Rodney, D.; Willaime, F.

    2015-06-01

    The relative stability of dislocation core configurations in body-centered-cubic metals is profoundly modified by the presence of solutes. Considering the Fe(C) system, we demonstrate by using density functional theory that carbon atoms destabilize the usual easy core to the benefit of the hard core configuration of the screw dislocation, which is unstable in pure metals. The carbon atom is at the center of a regular prism in a cementitelike local environment. The same dislocation core reconstruction is also found with other solutes (B, N, O) and in W(C). This unexpected low-energy configuration induces a strong solute-dislocation attraction, leading to dislocation core saturation by solute atoms, even for very low bulk solute concentrations. This core reconstruction will constitute an essential factor to account for in solute-segregation related phenomena, such as strain aging.

  2. 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

  3. 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.

  4. 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.

  5. Erosion-induced massive organic carbon burial and carbon emission in the Yellow River basin, China

    Science.gov (United States)

    Ran, L.; Lu, X. X.; Xin, Z.

    2014-02-01

    Soil erosion and terrestrial deposition of soil organic carbon (SOC) can potentially play a significant role in global carbon cycling. Assessing the redistribution of SOC during erosion and subsequent transport and burial is of critical importance. Using hydrological records of soil erosion and sediment load, and compiled organic carbon (OC) data, estimates of the eroded soils and OC induced by water in the Yellow River basin during the period 1950-2010 were assembled. The Yellow River basin has experienced intense soil erosion due to combined impact of natural process and human activity. Over the period, 134.2 ± 24.7 Gt of soils and 1.07 ± 0.15 Gt of OC have been eroded from hillslopes based on a soil erosion rate of 1.7-2.5 Gt yr-1. Approximately 63% of the eroded soils were deposited in the river system, while only 37% were discharged into the ocean. For the OC budget, approximately 0.53 ± 0.21 Gt (49.5%) was buried in the river system, 0.25 ± 0.14 Gt (23.5%) was delivered into the ocean, and the remaining 0.289 ± 0.294 Gt (27%) was decomposed during the erosion and transport processes. This validates the commonly held assumption that 20-40% of the eroded OC would be oxidized after erosion. Erosion-induced OC redistribution on the landscape likely represented a carbon source, although a large proportion of OC was buried. In addition, about half of the terrestrially redeposited OC (49.4%) was buried behind dams, revealing the importance of dam trapping in sequestering the eroded OC. Although several uncertainties need to be better constrained, the obtained budgetary results provide a means of assessing the redistribution of the eroded OC within the Yellow River basin. Human activities have significantly altered its redistribution pattern over the past decades.

  6. Erosion-induced massive organic carbon burial and carbon emission in the Yellow River basin, China

    Directory of Open Access Journals (Sweden)

    L. Ran

    2013-08-01

    Full Text Available Soil erosion and terrestrial deposition of soil organic carbon (SOC can potentially play a significant role in global carbon cycling. Assessing the fate of SOC during erosion and subsequent transport and sedimentation is of critical importance. Using hydrological records of soil erosion and sediment load, and compiled organic carbon (OC data, budgets of the eroded soils and OC induced by water in the Yellow River basin during 1950–2010 were analyzed. The Yellow River basin has experienced intense soil erosion due to integrated impact of natural process and human activity. Over the period, 134.2 ± 24.7 Gt of soils and 1.07 ± 0.26 Gt of OC have been eroded from slope lands based on a soil erosion rate of 1.7–2.5 Gt yr–1. Among the produced sediment, approximately 63% of it was deposited on land, while only 37% was discharged into the ocean. For the OC budget, approximately 0.53 ± 0.18 Gt (49.5% was buried on land, 0.25 ± 0.14 Gt (23.5% was delivered into the ocean, and the remaining 0.289 ± 0.202 Gt (27% was decomposed during the erosion and transport processes. This validates the commonly used assumption that 20–40% of the eroded OC would be oxidized after erosion. Erosion-induced OC transport in the basin likely represents an atmospheric carbon source. In addition, about half of the terrestrially redeposited OC (around 49.4% was buried in reservoirs and behind silt check dams, revealing the importance of dam sedimentation in trapping the eroded OC. Although with several uncertainties to be better constrained, the obtained budgetary results provide a means of assessing the potential fates of the eroded OC within the Yellow River basin.

  7. Biofilm-induced calcium carbonate precipitation: application in the subsurface

    Science.gov (United States)

    Phillips, A. J.; Eldring, J.; Lauchnor, E.; Hiebert, R.; Gerlach, R.; Mitchell, A. C.; Esposito, R.; Cunningham, A. B.; Spangler, L.

    2012-12-01

    We have investigated mitigation strategies for sealing high permeability regions, like fractures, in the subsurface. This technology has the potential to, for example, improve the long-term security of geologically-stored carbon dioxide (CO2) by sealing fractures in cap rocks or to mitigate leakage pathways to prevent contamination of overlying aquifers from hydraulic fracturing fluids. Sealing technologies using low-viscosity fluids are advantageous since they potentially reduce the necessary injection pressures and increase the radius of influence around injection wells. In this technology, aqueous solutions and suspensions are used to promote microbially-induced mineral precipitation which can be applied in subsurface environments. To this end, a strategy was developed to twice seal a hydraulically fractured, 74 cm (2.4') diameter Boyles Sandstone core, collected in North-Central Alabama, with biofilm-induced calcium carbonate (CaCO3) precipitates under ambient pressures. Sporosarcina pasteurii biofilms were established and calcium and urea containing reagents were injected to promote saturation conditions favorable for CaCO3 precipitation followed by growth reagents to resuscitate the biofilm's ureolytic activity. Then, in order to evaluate this process at relevant deep subsurface pressures, a novel high pressure test vessel was developed to house the 74 cm diameter core under pressures as high as 96 bar (1,400 psi). After determining that no impact to the fracture permeability occurred due to increasing overburden pressure, the fractured core was sealed under subsurface relevant pressures relating to 457 meters (1,500 feet) below ground surface (44 bar (650 psi) overburden pressure). After fracture sealing under both ambient and subsurface relevant pressure conditions, the sandstone core withstood three times higher well bore pressure than during the initial fracturing event, which occurred prior to biofilm-induced CaCO3 mineralization. These studies suggest

  8. Carbon induced magnetism of SnO2 surfaces

    International Nuclear Information System (INIS)

    The magnetism induced by Carbon (C) in SnO2 surfaces are investigated by first principle calculations. The results show that C substitution at the outmost surface oxygen sites can induce magnetism in (110), (001) and (101) surfaces of SnO2. (110) surface is the most stable surface and the magnetism in which is stronger than that in other two surfaces, indicating that it is (110), but not other surfaces provides the main contribution to the surface magnetism of C-doped SnO2 (SnO2:C). The magnetic moments predominantly come from C-2p orbitals, which arise from the crystal field transformation induced by the loss of coordinated atoms and the destroy of the local symmetry, and is enhanced by the local lattice distortion due to the Jahn–Teller effect. In all three surface slabs, the magnetism decays when C dopants are deeper from the outmost surfaces and disappears eventually. This work provides more rational understanding to the observed magnetism in SnO2:C materials than ever. - Highlights: • We investigate surface magnetism in (110), (001) and (101) surfaces of SnO2:C. • (110) surface provides the main contribution to the surface magnetism of SnO2:C. • Magnetism predominantly come from C-2p orbitals and crystal field transformation

  9. 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.

  10. 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

  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. Radiation induced chemical reaction of carbon monoxide and hydrogen mixture

    International Nuclear Information System (INIS)

    Previous studies of radiation induced chemical reactions of CO-H2 mixture have revealed that the yields of oxygen containing products were larger than those of hydrocarbons. In the present study, methane was added to CO-H2 mixture in order to increase further the yields of the oxygen containing products. The yields of most products except a few products such as formaldehyde increased with the addition of small amount of methane. Especially, the yields of trioxane and tetraoxane gave the maximum values when CO-H2 mixture containing 1 mol% methane was irradiated. When large amounts of methane were added to the mixture, the yields of aldehydes and carboxylic acids having more than two carbon atoms increased, whereas those of trioxane and tetraoxane decreased. From the study at reaction temperature over the range of 200 to 473 K, it was found that the yields of aldehydes and carboxylic acids showed maxima at 323 K. The studies on the effects of addition of cationic scavenger (NH3) and radical scavenger (O2) on the products yields were also carried out on the CO-H2-CH4 mixture. (author)

  13. 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.

  14. 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...

  15. Analysis of mutagenic effects induced by carbon beams at different LET in a red yeast strain

    International Nuclear Information System (INIS)

    To evaluate inactive and mutagenic effects of carbon beam at different LET, the inactivation cross section and mutation cross section induced by carbon beams of different LET values were investigated in a red yeast strain Rhodotorula glutinis AY 91015. It was found that the maximum inactivation cross section of 4.37μm2, which was very close to the average nucleus cross section, was at LET of 120.0 keV/μm. The maximum mutation cross section was at LET of 96.0 keV/μm. Meanwhile, the highest mutagenicity of carbon ion was found around 58.2 keV/μm. It implied that the most efficient LET to induce mutation in survival yeasts was 58.2 keV/μm, which corresponded to energy of 35 MeV/u carbon beam. The most effective carbon beam to induce inactivation and mutation located at different energy region. (authors)

  16. 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

  17. 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...

  18. Carbon monoxide poisoning-induced cardiomyopathy from charcoal at a barbecue restaurant: a case report

    OpenAIRE

    Kim, Hyun-Jun; Chung, Yun Kyung; Kwak, Kyeong Min; Ahn, Se-Jin; Kim, Yong-Hyun; Ju, Young-Su; Kwon, Young-Jun; Kim, Eun-A

    2015-01-01

    Objective Acute carbon monoxide poisoning has important clinical value because it can cause severe adverse cardiovascular effects and sudden death. Acute carbon monoxide poisoning due to charcoal is well reported worldwide, and increased use of charcoal in the restaurant industry raises concern for an increase in occupational health problems. We present a case of carbon monoxide poisoning induced cardiomyopathy in a 47-year-old restaurant worker. Materials and methods A male patient was broug...

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

    OpenAIRE

    Ruslana Vasylkovska; Natalia Petriv; Halyna Semchyshyn

    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) meta...

  20. On the properties of zirconium and hafnium tetrachlorides and their saturated solutions

    International Nuclear Information System (INIS)

    The properties of saturated vapor of zirconium tetrachloride and hafnium tetrachloride were determined by investigating the P-V-T-N dependence of these compounds in gas phase. For each compound measurements were made of the molar volume and pressure of saturated vapor and the dependence of these parameters on the temperature. The saturated vapor of zirconium tetrachloride and hafnium tetrachloride obeys the ideal gas law starting with the following values of pressure, molar volume and temperature respectively: 2.5 kg/cm2, 20600 cm3/mole, 360 deg C and 2.6 kg/cm2, 19600 cm3/mole, 340 deg C. Phase diagram within P-N coordinates of the ZrCl4-HfCl4 system, calculated by using the state equation and Biron equation, was approximately the same as reported in previous papers

  1. Carbon particle induced foaming of molten sucrose for the preparation of carbon foams

    Energy Technology Data Exchange (ETDEWEB)

    Narasimman, R.; Vijayan, Sujith; Prabhakaran, K., E-mail: kp2952002@gmail.com

    2014-11-15

    Graphical abstract: - Highlights: • An easy method for the preparation of carbon foam from sucrose is presented. • Wood derived activated carbon particles are used to stabilize the molten sucrose foam. • The carbon foams show relatively good mechanical strength. • The carbon foams show excellent CO{sub 2} adsorption and oil absorption properties. • The process could be scaled up for the preparation of large foam bodies. - Abstract: Activated carbon powder was used as a foaming and foam setting agent for the preparation of carbon foams with a hierarchical pore structure from molten sucrose. The rheological measurements revealed the interruption of intermolecular hydrogen bonding in molten sucrose by the carbon particles. The carbon particles stabilized the bubbles in molten sucrose by adsorbing on the molten sucrose–gas interface. The carbon foams obtained at the activated carbon powder to sucrose weight ratios in the range of 0–0.25 had a compressive strength in the range of 1.35–0.31 MPa. The produced carbon foams adsorb 2.59–3.04 mmol/g of CO{sub 2} at 760 mmHg at 273 K and absorb oil from oil–water mixtures and surfactant stabilized oil-in-water emulsions with very good selectivity and recyclability.

  2. 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, ...

  3. Study of interaction of zirconium- and hafnium tetrachlorides with some amino acids

    International Nuclear Information System (INIS)

    Zirconium complexes with α-alanine, anthranilic and nicotinic acids, as well as hafnium complex with anthranilic acid have been synthesized by interaction of zirconium and hafnium tetrachlorides with the amino acids in absolute ethylacetate in dry atmosphere. Coordination of ligands is being deduced from the infrared spectra of the compounds. Tetrachlorides of the metals in non-aqueous media react with amino acids to form compounds involving participation of nitrogen atoms

  4. Radiation polymerization of vinylene carbonate

    International Nuclear Information System (INIS)

    The radiation-induced polymerization of vinylene carbonate of 99,97% purity has been investigated. The relationship between conversion and irradiation time is strictly linear, even at the lowest conversions, thus proving that the normal induction period observed for the polymerization of lower-purity vinylene carbonate indeed results from the presence of an inhibitor. Although the identity of the inhibitor has not been established, it has been shown that it is not dichlorovinylene carbonate. An activation energy of 15,1 kJ/mole was calculated for the homopolymerization process. The radiation-induced copolymerization of vinylene carbonate (M1) with isobutyl vinyl ether (M2) has been investigated over the temperature range of 40-80 degrees Celcius. The monomer reactivity ratios r1 and r2 were determined to be 0,118 and 0,148 respectively, and an activation energy of 31,8kJ/mole was calculated for the copolymerization process. The radiation-induced telomerization of vinylene carbonate with carbon tetrachloride has been investigated over a telogen to monomer concentration ratio range of 4 to 20. The rate of formation of the n=1 adduct was found to be independent of monomer concentration, directly proportional to the telogen concentration, and exhibiting a 0,38 order power dependence on the radiation intensity, in general agreement with the derived rate equations. The rate of formation of the n=2 telomer was found to be independent of both monomer and telogen concentrations and radiation intensity, which is not in agreement with the derived rate equations. The first and second chain-transfer coefficients C1 and C2 were determined to be 0,116 and 0,34 respectively, and the activation energies for the formation of the n=1 adduct and n=2 telomer were calculated to be 17,6 and 64,9 kJ/mole respectively

  5. Charge-induced strains in single-walled carbon nanotubes.

    Science.gov (United States)

    Li, Chun-Yu; Chou, Tsu-Wei

    2006-09-28

    This paper investigates the electromechanical coupling in single-walled carbon nanotubes. In the model system, the extra electric charge of the nanotube is assumed to be uniformly distributed on carbon atoms. The electrostatic interactions between charged carbon atoms are calculated using the Coulomb law. The deformation of the charged nanotube is obtained by using the molecular structural mechanics method and considering the electrostatic interactions as an external loading acting on carbon atoms. The axial strain is found to be a symmetric function of applied charge, and our predictions are in very good agreement with those from ab initio calculations. The present results indicate that the nanotube aspect ratio has a strong effect on the axial strain when the ratio is less than 10 and the general trend is that the strain increases with the aspect ratio. The peak axial and radial strains occur at nanotube diameters of around 1.2-1.5 nm. PMID:21727586

  6. Soil carbon and nitrogen erosion in forested catchments: implications for erosion-induced terrestrial carbon sequestration

    Science.gov (United States)

    Stacy, E. M.; Hart, S. C.; Hunsaker, C. T.; Johnson, D. W.; Berhe, A. A.

    2015-08-01

    Lateral movement of organic matter (OM) due to erosion is now considered an important flux term in terrestrial carbon (C) and nitrogen (N) budgets, yet most published studies on the role of erosion focus on agricultural or grassland ecosystems. To date, little information is available on the rate and nature of OM eroded from forest ecosystems. We present annual sediment composition and yield, for water years 2005-2011, from eight catchments in the southern part of the Sierra Nevada, California. Sediment was compared to soil at three different landform positions from the source slopes to determine if there is selective transport of organic matter or different mineral particle size classes. Sediment export varied from 0.4 to 177 kg ha-1, while export of C in sediment was between 0.025 and 4.2 kg C ha-1 and export of N in sediment was between 0.001 and 0.04 kg N ha-1. Sediment yield and composition showed high interannual variation. In our study catchments, erosion laterally mobilized OM-rich litter material and topsoil, some of which enters streams owing to the catchment topography where steep slopes border stream channels. Annual lateral sediment export was positively and strongly correlated with stream discharge, while C and N concentrations were both negatively correlated with stream discharge; hence, C : N ratios were not strongly correlated to sediment yield. Our results suggest that stream discharge, more than sediment source, is a primary factor controlling the magnitude of C and N export from upland forest catchments. The OM-rich nature of eroded sediment raises important questions about the fate of the eroded OM. If a large fraction of the soil organic matter (SOM) eroded from forest ecosystems is lost during transport or after deposition, the contribution of forest ecosystems to the erosion-induced C sink is likely to be small (compared to croplands and grasslands).

  7. 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.

  8. 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

  9. Low concentration of exogenous carbon monoxide protects mammalian cells against proliferation induced by radiation-induced bystander effect

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Liping [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Yu, K.N. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong (Hong Kong); Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Bao, Lingzhi; Wu, Wenqing; Wang, Hongzhi [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China); Han, Wei, E-mail: hanw@hfcas.cn [Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031 (China)

    2014-01-15

    Highlights: • We show the possibility of modulate proliferation induced by radiation-induced bystander effect with low concentration carbon monoxide. • Carbon monoxide inhibited proliferation via modulating the transforming growth factor β1 (TGF-β1)/nitric oxide (NO) signaling pathway. • Exogenous carbon monoxide has potential application in clinical radiotherapy. - Abstract: Radiation-induced bystander effect (RIBE) has been proposed to have tight relationship with the irradiation-caused secondary cancers beyond the irradiation-treated area after radiotherapy. Our previous studies demonstrated a protective effect of low concentration carbon monoxide (CO) on the genotoxicity of RIBE after α-particle irradiation. In the present work, a significant inhibitory effect of low-dose exogenous CO, generated by tricarbonyldichlororuthenium (II) dimer [CO-releasing molecule (CORM-2)], on both RIBE-induced proliferation and chromosome aberration was observed. Further studies on the mechanism revealed that the transforming growth factor β1/nitric oxide (NO) signaling pathway, which mediated RIBE signaling transduction, could be modulated by CO involved in the protective effects. Considering the potential of exogenous CO in clinical applications and its protective effect on RIBE, the present work aims to provide a foundation for potential application of CO in radiotherapy.

  10. Low concentration of exogenous carbon monoxide protects mammalian cells against proliferation induced by radiation-induced bystander effect

    International Nuclear Information System (INIS)

    Highlights: • We show the possibility of modulate proliferation induced by radiation-induced bystander effect with low concentration carbon monoxide. • Carbon monoxide inhibited proliferation via modulating the transforming growth factor β1 (TGF-β1)/nitric oxide (NO) signaling pathway. • Exogenous carbon monoxide has potential application in clinical radiotherapy. - Abstract: Radiation-induced bystander effect (RIBE) has been proposed to have tight relationship with the irradiation-caused secondary cancers beyond the irradiation-treated area after radiotherapy. Our previous studies demonstrated a protective effect of low concentration carbon monoxide (CO) on the genotoxicity of RIBE after α-particle irradiation. In the present work, a significant inhibitory effect of low-dose exogenous CO, generated by tricarbonyldichlororuthenium (II) dimer [CO-releasing molecule (CORM-2)], on both RIBE-induced proliferation and chromosome aberration was observed. Further studies on the mechanism revealed that the transforming growth factor β1/nitric oxide (NO) signaling pathway, which mediated RIBE signaling transduction, could be modulated by CO involved in the protective effects. Considering the potential of exogenous CO in clinical applications and its protective effect on RIBE, the present work aims to provide a foundation for potential application of CO in radiotherapy

  11. 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

    in a myograph. After precontraction with the prostaglandin analogue U46619, the vasorelaxing effect of the carbonic anhydrase inhibitors methyl bromopyruvate, ethyl bromopyruvate, acetazolamide, and dorzolamide were studied. RESULTS: All the examined carbonic anhydrase inhibitors induced a...

  12. Kadar Perasan Kunyit yang Efektif Memperbaiki Kerusakan Hati Mencit yang Dipicu Karbon Tetrachlorida (THE EFFICACY OF TURMERIC JUICE ON PATHOLOGICAL CHANGES OF THE MICE LIVER BY INDUCED CARBON TETRACHLORIDE)

    OpenAIRE

    I Made Kardena; Ida Bagus Oka Winaya

    2012-01-01

    A study on effect of various concentrations of turmeric juice on pathological changes mice liver hasbeen carried out. As many as 25 mice were used in this study and they were divided into 5 groups, i.e.: groupK-: 0.2 ml vegetable oil without CCl4; group K+: CCl4 without turmeric extract; group T1: CCl4 with 10%turmeric extract; group T2: CCl4 with 20% turmeric extract and group T3: CCl4 with 30% turmeric extract.All mice, except the K- group, were treated with 0.2 ml CCl4 orally for 7 days. O...

  13. 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...

  14. Oscillation induced worm-like locomotion of carbon nanotubes.

    Science.gov (United States)

    Cheng, Tung-Wen; Lu, Chieh-Lien; Lai, Yao-Chen; Kuo, Hsin-Fu; Fang, Weileun; Tai, Nyan-Hwa; Hsu, Wen-Kuang

    2010-08-21

    Harmonic oscillation of a doubly clamped single-walled carbon nanotube rope is significantly damped by the resistive force of friction at intertube contacts and the energy transmission rate has been estimated to be lower than that on a metal wire excited at similar frequency and vibrating length by one order of magnitude. PMID:20532280

  15. 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

  16. 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.

  17. 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.

  18. 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...

  19. Argon laser induced changes to the carbonate content of enamel

    Energy Technology Data Exchange (ETDEWEB)

    Ziglo, M.J. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Private Practice, Regina, Saskatchewan (Canada); Nelson, A.E., E-mail: aenelson@dow.com [Department of Chemical and Materials Engineering, Faculty of Engineering, University of Alberta (Canada); Heo, G.; Major, P.W. [Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta (Canada)

    2009-05-15

    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{sup -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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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

  5. Current-induced dynamics in carbon atomic contacts

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  6. 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.

  7. Thermal and radiation induced polymerisation of carbon sub-oxide

    International Nuclear Information System (INIS)

    This research thesis addresses the study of the polymerisation of carbon sub-oxide (C3O2) in gaseous phase. As this work is related to other researches dealing with the reactions of the graphite-CO2 system which occur in graphite-moderated nuclear reactors, a first intention was to study the behaviour of C3O2 when submitted to radiations. Preliminary tests showed that the most remarkable result of this action was the formation of a polymer. It was also noticed that the polymerisation of this gas was spontaneous however slower at room temperature. The research thus focused on this polymerisation, and on the formula of the obtained polymer. After some generalities, the author reports the preparation, purification and storage and conservation of the carbon sub-oxide. The next parts report the kinetic study of thermal polymerisation, the study of polymerisation under γ rays, the study of the obtained polymer by using visible, UV and infrared spectroscopy, electronic paramagnetic resonance, and semi-conductivity measurements

  8. 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

  9. 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

  10. Desorption Behavior of Carbon Tetrachloride and Chloroform in contaminated Low Organic Carbon Aquifer Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert G.; Szecsody, Jim E.; Sklarew, Debbie S.; Mitroshkov, Alexandre V.; Gent, Philip M.; Brown, Christopher F.; Thompson, Christopher J.

    2010-05-01

    Experimental determination of contaminant behavior in deep aquifer sediments is challenging because of the cost and difficulty associated with sample collection. On the other hand, parameter values important to contaminant transport (e.g., distribution coefficient) derived from such sediments may be more accurate than those determined by estimation methods. Furthermore, experiments performed with sediments where the contaminants have been in contact with the sediments for decades are more likely to reveal kinetic controls on contaminant transport not as readily revealed in short contact time experiments. We report the first measurements of CCl4 and CHCl3 distribution coefficients in contaminated Hanford sediments with varying physical/chemical properties.

  11. 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)

  12. 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...

  13. 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.)

  14. 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.)

  15. 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

  16. 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.

  17. 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

  18. 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...

  19. Current-induced changes of migration energy barriers in graphene and carbon nanotubes.

    Science.gov (United States)

    Obodo, J T; Rungger, I; Sanvito, S; Schwingenschlögl, U

    2016-05-21

    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. PMID:27127889

  20. Rechargeable Batteries with High Energy Storage Activated by In-situ Induced Fluorination of Carbon Nanotube Cathode

    OpenAIRE

    Xinwei Cui; Jian Chen; Tianfei Wang; Weixing Chen

    2014-01-01

    High performance rechargeable batteries are urgently demanded for future energy storage systems. Here, we adopted a lithium-carbon battery configuration. Instead of using carbon materials as the surface provider for lithium-ion adsorption and desorption, we realized induced fluorination of carbon nanotube array (CNTA) paper cathodes, with the source of fluoride ions from electrolytes, by an in-situ electrochemical induction process. The induced fluorination of CNTA papers activated the revers...

  1. Charge-induced actuation in carbon nanotubes and resistance changes in carbon nanotube networks

    Science.gov (United States)

    Sippel-Oakley, Jennifer Ann

    In 1999 it was demonstrated that macroscopic films comprised of single wall carbon nanotubes exhibited dimensional changes with charge injection onto the films. A fundamental mechanism was proposed for this effect related to the dimensional changes observed in graphite intercalation complexes upon charge transfer doping with the intercalant species. The major fraction of this thesis concerns experiments at the single nanotube level designed to test the validity of this mechanism. The metals compatible with our fabrication processes inevitably p-dope the nanotubes resulting in smaller dimensional changes. Additionally, there are contact barriers that prevent the injection of electrons onto the nanotubes. Although the proposed mechanism may still be responsible for the results seen in the nanotube films, the effect is too small to be consistently measured in individual nanotubes. The conductivity of a carbon nanotube can be varied by exposure to various chemicals having utility in chemical sensing applications. We use thin films of carbon nanotubes to exploit this effect. The films are made sensitive to hydrogen by association with palladium metal. Such sensors operate at room temperature with very low power dissipation of ˜0.25 mV.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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......H. In terms of carbon source, all species took up both CO2 and HCO3-. K-1/2 values for inorganic carbon uptake decreased with increasing pH in two species, while in N. navis-varingica apparent affinities did not change. While the contribution of HCO3- to net fixation was more than 85% in S. stellaris...

  11. 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...

  12. 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.

  13. 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.

  14. Shear-induced structure evolution of carbon nanotubes dispersions in polyacrylonitrile-dimethylsulfoxide solution

    Science.gov (United States)

    Karpushkin, Evgeny; Lapshina, Maria; Sergeyev, Vladimir

    2015-04-01

    Rheological behavior of carbon nanotubes finely dispersed in polyacrylonitrile-dimethylsulfoxide solution has been studied as function of the applied pre-shear stress and discussed in view of possible structural changes induced by the pre-shearing of the samples. The observed effects can be ascribed to a combination of internal processes involving alignment and association of the macromolecules as well as orientation and association of carbon nanotubes. The effects caused by the macromolecules alignment and association are mainly observed at low concentration of the filler and at higher shear stress, whereas the processes involving carbon nanotubes reorganization are mainly observed at the higher filler content and at low pre-shear stress.

  15. High ordered biomineralization induced by carbon nanoparticles in the sea urchin Paracentrotus lividus

    International Nuclear Information System (INIS)

    A surprising and unexpected biomineralization process was observed during toxicological assessment of carbon nanoparticles on Paracentrotus lividus (sea urchin) pluteus larvae. The larvae activate a process of defense against external material, by incorporating the nanoparticles into microstructures of aragonite similarly to pearl oysters. Aiming at a better understanding of this phenomenon, the larvae were exposed to increasing concentrations of carbon nanoparticles and the biomineralization products were analyzed by electron microscopy, x-ray diffraction and Raman spectroscopy. In order to evaluate the possible influence of Sp-CyP-1 expression on this biomineralization process by larvae, analyses of gene expression (Sp-CyP-1) and calcein labeling were performed. Overall, we report experimental evidence about the capability of carbon nanoparticles to induce an increment of Sp-CyP-1 expression with the consequent activation of a biomineralization process leading to the production of a new pearl-like biomaterial never previously observed in sea urchins. (paper)

  16. Ozone-induced stomatal sluggishness changes carbon and water balance of temperate deciduous forests

    OpenAIRE

    Yasutomo Hoshika; Genki Katata; Makoto Deushi; Makoto Watanabe; Takayoshi Koike; Elena Paoletti

    2015-01-01

    Tropospheric ozone concentrations have increased by 60–100% in the Northern Hemisphere since the 19th century. The phytotoxic nature of ozone can impair forest productivity. In addition, ozone affects stomatal functions, by both favoring stomatal closure and impairing stomatal control. Ozone-induced stomatal sluggishness, i.e., a delay in stomatal responses to fluctuating stimuli, has the potential to change the carbon and water balance of forests. This effect has to be included in models for...

  17. 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 ...

  18. Assembly of Carbon Nanotubes between Electrodes by Utilizing Optically Induced Dielectrophoresis and Dielectrophoresis

    OpenAIRE

    Gwo-Bin Lee; Pei-Fang Wu

    2011-01-01

    This study reports a new approach for assembling carbon nanotubes (CNTs) between electrodes combination of optically induced dielectrophoresis force and dielectrophoresis force. Metal electrodes and amorphous silicon layer were first patterned and then used to assemble CNTs. By utilizing moving light patterns, the CNTs could be collected to the central area between two metal electrodes. The CNTs with different concentrations can be collected and aligned to form CNTs lines with different width...

  19. Carbon monoxide inhibits Fas activating antibody-induced apoptosis in endothelial cells

    OpenAIRE

    Wang Xue; Wang Yong; Lee Seon-Jin; Kim Hong Pyo; Choi Augustine MK; Ryter Stefan W

    2011-01-01

    Abstract Background The extrinsic apoptotic pathway initiates when a death ligand, such as the Fas ligand, interacts with its cell surface receptor (ie., Fas/CD95), forming a death-inducing signaling complex (DISC). The Fas-dependent apoptotic pathway has been implicated in several models of lung or vascular injury. Carbon monoxide, an enzymatic product of heme oxygenase-1, exerts antiapoptotic effects at low concentration in vitro and in vivo. Methods Using mouse lung endothelial cells (MLEC...

  20. Carbon Monoxide Inhibits Hypoxia/Reoxygenation-Induced Apoptosis and Secondary Necrosis in Syncytiotrophoblast

    OpenAIRE

    Bainbridge, Shannon A.; Belkacemi, Louiza; Dickinson, Michelle; Graham, Charles H.; Smith, Graeme N

    2006-01-01

    Pre-eclampsia, a hypertensive disorder of pregnancy, affects 5 to 7% of pregnancies. Oxidative stress-induced placental injury and subsequent release of placental debris into the maternal circulation are key pathogenic events in the progression of pre-eclampsia. Women who smoke cigarettes throughout pregnancy are 33% less likely to develop this disorder than nonsmoking women. We postulated that elevated carbon monoxide concentrations in serum of smoking women inhibits apoptosis and debris she...

  1. Carbon nanotubes induce inflammation but decrease the production of reactive oxygen species in lung

    OpenAIRE

    Crouzier, D.; Follot, S.; Gentilhomme, E.; Flahaut, Emmanuel; Arnaud, R.; Dabouis, V.; Castellarin, C.; Debouzy, J.C.

    2010-01-01

    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. ...

  2. 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

  3. Laser-induced breakdown spectroscopy (LIBS) for carbon single shot analysis of micrometer-sized particles

    International Nuclear Information System (INIS)

    The purpose of this work is to study the ability of the laser-induced breakdown spectroscopy (LIBS) technique to perform in situ (without sample preparation) detection of graphite particles circulating in a gas loop used to simulate the cooling gas circuit of a helium-cooled nuclear reactor. Results obtained with a laboratory scale set up are presented. The experiments were performed in nitrogen with micrometer-sized particles containing carbon (glucose particles and sodium hydrogeno-carbonate particles). Statistical shot to shot analysis was used to determine the concentration of the analyte. The variation of LIBS signal as a function of glucose particle diameter showed an underestimation of the signal of particles of diameters larger than 5 μm. This phenomenon is likely to be correlated to an incomplete vaporization in the laser-induced plasma of particles of sizes above 5 μm. Analytical measurements were performed with glucose particles and sodium hydrogeno-carbonate particles, and the concentration-based limit of detection of carbon was evaluated to be about 60 μg m-3. (authors)

  4. Low concentration of exogenous carbon monoxide protects mammalian cells against proliferation induced by radiation-induced bystander effect.

    Science.gov (United States)

    Tong, Liping; Yu, K N; Bao, Lingzhi; Wu, Wenqing; Wang, Hongzhi; Han, Wei

    2014-01-01

    Radiation-induced bystander effect (RIBE) has been proposed to have tight relationship with the irradiation-caused secondary cancers beyond the irradiation-treated area after radiotherapy. Our previous studies demonstrated a protective effect of low concentration carbon monoxide (CO) on the genotoxicity of RIBE after α-particle irradiation. In the present work, a significant inhibitory effect of low-dose exogenous CO, generated by tricarbonyldichlororuthenium (II) dimer [CO-releasing molecule (CORM-2)], on both RIBE-induced proliferation and chromosome aberration was observed. Further studies on the mechanism revealed that the transforming growth factor β1/nitric oxide (NO) signaling pathway, which mediated RIBE signaling transduction, could be modulated by CO involved in the protective effects. Considering the potential of exogenous CO in clinical applications and its protective effect on RIBE, the present work aims to provide a foundation for potential application of CO in radiotherapy. PMID:24333162

  5. 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

  6. 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

  7. 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...

  8. 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.

  9. 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

  10. 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.

  11. Climate-induced tree mortality: earth system consequences for carbon, energy, and water exchanges

    Science.gov (United States)

    Adams, H. D.; Macalady, A.; Breshears, D. D.; Allen, C. D.; Luce, C.; Royer, P. D.; Huxman, T. E.

    2010-12-01

    subsurface flow, runoff, groundwater recharge, and streamflow. Under some circumstances there may also be increased flood risks. We hypothesized thresholds of mean annual precipitation and canopy cover reduction identified from the forest harvesting literature as minima that must be exceeded for die-off to noticeably affect hydrologic processes. We note exceptions to these thresholds when snowmelt dominates the watershed hydrology and when mortality affects a single species with a unique hydrologic role. Management options for mitigating die-off effects on ecosystem and earth system processes and implementing post-die-off restoration will likely be limited and costly, requiring ecological and societal adaptation in many areas. As such, climate-induced tree mortality poses a significant risk to the current earth system function through altered exchanges of carbon, energy, and water between the land surface and atmosphere.

  12. 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.

  13. 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 ...

  14. 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.

  15. Ground state C2 density measurement in carbon plume using laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    The temporal evolution and spatial distribution of C2 molecules produced by laser ablation of a graphite target is studied using optical emission spectroscopy, dynamic imaging and laser-induced fluorescence (LIF) investigations. We observe peculiar bifurcation of carbon plume into two parts; stationary component close to the target surface and a component moving away from the target surface which splits further in two parts as the plume expands. The two distinct plumes are attributed to recombination of carbon species and formation of nanoparticles. The molecular carbon C2 moves with a faster velocity and dies out at ∼ 800 ns whereas the clusters of nanoparticle move with a slower velocity due to their higher mass and can be observed even after 1600 ns. C2 molecules in the d3Πg state were probed for laser-induced fluorescence during ablation of graphite using the Swan (0,0) band at 516.5 nm. The fluorescence spectrum and images of fluorescence d3Πg - a3Πu(0,1)(λ = 563.5 nm) are recorded using a spectrograph attached to the ICCD camera. To get absolute ground state C2 density from fluorescence images, the images are calibrated using complimentary absorption experiment. This study qualitatively helps to get optimum conditions for nanoparticle formation using the laser ablation of graphite target and hence deducing optimum conditions for thin film deposition.

  16. Characterization of ion-irradiation-induced defects in multi-walled carbon nanotubes

    Science.gov (United States)

    Lehtinen, Ossi; Nikitin, Timur; Krasheninnikov, Arkady V.; Sun, Litao; Banhart, Florian; Khriachtchev, Leonid; Keinonen, Juhani

    2011-07-01

    We study the effects of Ar+, He+ and C+ ion irradiation on multi-walled carbon nanotubes at room and elevated temperatures with transmission electron microscopy (TEM) and Raman spectroscopy. Based on the TEM data, we introduce a universal damage scale for the visual analysis and characterization of irradiated nanotubes. We show for the first time that the amount of irradiation-induced damage in nanotubes is larger than the value predicted for bulk materials using the simple binary collision approximation, which may be associated with higher defect production due to electronic stopping in these nanoscale systems. The Raman spectra of the irradiated samples are in qualitative agreement with the TEM data and indicate the presence of irradiation-induced defects. However, it is difficult to obtain quantitative information on defect concentration due to non-uniform distribution of defects in the nanotube films and in part due to the presence of other carbon nanosystems in the samples, such as graphitic crystallites and carbon onions.

  17. 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

  18. Inducing low-carbon investment in the electric power industry through a price floor for emissions trading

    International Nuclear Information System (INIS)

    Uncertainty about long-term climate policy is a major driving force in the evolution of the carbon market price. Since this price enters the investment decision process of regulated firms, this uncertainty increases the cost of capital for investors and might deter investments into new technologies at the company level. We apply a real options-based approach to assess the impact of climate change policy in the form of a constant or growing price floor on investment decisions of a single firm in a competitive environment. This firm has the opportunity to switch from a high-carbon “dirty” technology to a low-carbon “clean” technology. Using Monte Carlo simulation and dynamic programming techniques for real data, we determine the optimal CO2 price floor level and growth rate in order to induce investments into the low-carbon technology. We find that a carbon price floor can be used to induce earlier low-carbon technology investment and show this result to be robust to a large variety of input parameter settings. - Highlights: ► We model the investment decision of an electricity generating company. ► The company can invest in low and high carbon technologies. ► We investigate different carbon price floor designs. ► A carbon price floor leads to earlier investment into low-carbon technology.

  19. 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

  20. Optimization of the Deposition Conditions of Titanium Nitride from Ammonia and Titanium Tetrachloride

    OpenAIRE

    Nadal, M.; Teyssandier, F.

    1995-01-01

    TiN has been used in numerous technological applications including : cutting or milling tools and inserts, cold extrusion nozzles and punches, forming or stamping tools, and diffusion barrier. It is currently deposited from an initial gas mixture composed of hydrogen, ammonia and titanium tetrachloride. This paper reports on the optimization of its deposition conditions at atmospheric pressure. A complete factorial design with three factors and two levels, thus requiring 23=8 experiments, has...

  1. A reversible strain-induced electrical conductivity in cup-stacked carbon nanotube

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, T [Shinshu University; Morokuma, Keiji [ORNL; Meunier, Vincent [ORNL; Meunier, V. [Rensselaer Polytechnic Institute (RPI); Terrones Maldonado, Mauricio [ORNL; Muramatsu, H [Shinshu University; Sumpter, Bobby G [ORNL; Kim, Y A [Shinshu University

    2013-01-01

    We have used in-situ current-voltage measurements of cup-stacked carbon nanotubes (CSCNTs) to establish a reversible strain induced (compressive bending) semiconducting to metallic behavior. The corresponding electrical resistance decreases by two orders of magnitude during the process, and reaches values comparable to those of highly crystalline multi-walled carbon nanotube (MWCNT) and graphite. Joule heating experiments on the same CSCNTs showed that the edges of individual cups merge to form loops induced by the heating process. The resistance of these looped CSCNTs was close to that of highly deformed CSCNTs (and crystalline MWCNTs), thus suggesting that a similar conduction mechanism took place in both cases. Using a combination of molecular dynamics and first-principles calculations based on density functional theory, we conclude that an edge-to-edge interlayer transport mechanism results in conduction channels at the compressed side of the CSCNTs due to electronic density overlap between individual cups, thus making CSCNT more conducting. This strain-induced CSCNT semiconductor to metal transition could potentially be applied to enabling functional composite materials (e.g. mechanical sensors) with enhanced and tunable conducting properties upon compression.

  2. Magnetic-field-induced diameter-selective synthesis of single-walled carbon nanotubes.

    Science.gov (United States)

    Su, Yanjie; Zhang, Yaozhong; Wei, Hao; Zhang, Liling; Zhao, Jiang; Yang, Zhi; Zhang, Yafei

    2012-03-01

    We report a facile and scalable approach to synthesize single-walled carbon nanotubes (SWNTs) with selected diameter distribution by applying a magnetic field perpendicular to the electric field in the arc plasma region. It is found that this magnetic field-induced diameter-selectivity strategy enables the control of the SWNTs with different diameter distributions in different regions, and the diameter-selective efficiency could be enhanced by modifying the direction of magnetic field. Our results indicate that the motions of the catalysts with different particle sizes, positive carbon ions and electrons are significantly influenced by the magnetic field and electromagnetic force, resulting in the different nucleation and growth processes of SWNTs due to the collective interactions between the magnetic field and arc plasma. This approach would enable a viable route towards the synthesis of SWNTs with desired diameter through the tuning of arc parameters in the arc discharge process. PMID:22301844

  3. Compositional analysis of ferroelectric films coated with carbon layer using laser-induced plasmas spectroscopy

    International Nuclear Information System (INIS)

    An experimental investigation of the effect of different thickness of carbon layer coated on ferroelectric films on the atomic emission intensity using laser-induced plasmas spectroscopy technique with charge-coupled device (CCD) experimental system has been conducted. The experimental results show that the intensity of the spectra emitted with the carbon layer thickness of 15 μm is much higher than that of pure ferroelectric films. By using this best experimental condition, the atomic concentration ratios of ferroelectric films are evaluated by rationing the integrated intensities of selected spectral emission lines of the plasma produced from the films. And the experimental results show that NLa/NCo and NSr/NCo atomic concentration ratios are almost in agreement with the corresponding values obtained by traditional compositional analysis techniques of inductively coupled plasma (ICP).

  4. Analysis of allyl diglycol carbonate by laser induced-breakdown spectroscopy

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) has been used to identify the impurities in the allyl diglycol carbonate, which is used as a charged particle track recording material in solid-state nuclear track detectors. Impurities of magnesium, calcium, sodium and silicon are detected. Plasma parameters such as temperature and electron density are also calculated at optimized conditions in air and argon atmosphere using the silicon lines. The temperature of the LIBS plasma produced in argon atmosphere was higher than the temperature of the LIBS plasma produced in air. Variation in the emission intensity of the carbon I line (247.8561 nm) with respect to acquisition delay and laser power is also studied. It is found that the intensities of Ca and Na lines from LIBS spectra were enhanced 30–40 times in an argon atmosphere as compared to air. Hence LIBS in an argon atmosphere can be used for better identification of impurities in plastics. (paper)

  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. Study of lifetimes of fluorescence levels of tetravalent uranium in the incommensurate phase of thorium tetrabromide and tetrachloride

    International Nuclear Information System (INIS)

    The lifetimes of radiative levels of tetravalent uranium in the incommensurate phase of thorium tetrahalides have been measured as a function of different parameters: site symmetry, temperature and concentration. The incommensurate phase of thorium tetrabromide and tetrachloride is characterized by a continuous distribution of site symmetries induced by a continuous and weak displacement of the halides around the thorium (uranium) ions. At low temperature, 4.2 K, the lifetime variation as a function of excited classes of symmetry is governed by the radiative process probability as well as the energy transfer between uranium ions in different sites. At higher temperature, a model based on a Boltzmann equilibrium between closed energy levels is able to reproduce the experimental lifetime variation as a function of the temperature, for a given class of symmetry. For the variation of lifetime as a function of uranium ion concentrations, at high dilution and in the case of U4+: ThBr4, there is a competition between the energy transfer and thermal population of excited states

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  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. 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

  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. Inducing chalcogenide phase change with ultra-narrow carbon nanotube heaters

    Science.gov (United States)

    Xiong, Feng; Liao, Albert; Pop, Eric

    2009-12-01

    Carbon nanotube (CNT) heaters with sub-5 nm diameter induce highly localized phase change in Ge2Sb2Te5 (GST) chalcogenide. A significant reduction in resistance of test structures is measured as the GST near the CNT heater crystallizes. Effective GST heating occurs at currents as low as 25 μA, significantly lower than in conventional phase change memory with metal electrodes (0.1-0.5 mA). Atomic force microscopy reveals nucleation sites associated with phase change in GST around the CNT heater. Finite element simulations confirm electrical characteristics consistent with the experiments, and reveal the current and phase distribution in GST.

  17. Carbon dots with aggregation induced emission enhancement for visual permittivity detection.

    Science.gov (United States)

    Liu, Ze Xi; Wu, Zhu Lian; Gao, Ming Xuan; Liu, Hui; Huang, Cheng Zhi

    2016-01-26

    Photoluminescent carbon dots (CDs), hydrothermally prepared using tannic acid (TA), show visual aggregation induced emission enhancement (AIEE) properties at 455 nm when excited at 350 nm owing to the rotational hindering of the surface groups on CDs such as aromatic rings and phenolic hydroxyl ones, causing exponential decay between the ratio of the photoluminescence intensity in organic solvents to that in water and the permittivity of the solvent, and thus dazzling emissions of the CDs in the presence of solvents with small permittivity, tetrahydrofuran (THF), for instance, could be visually observed. PMID:26688276

  18. 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...

  19. 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.

  20. 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

  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. 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.

  3. 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.

  4. Effects of exogenous carbon monoxide on radiation-induced bystander effect in zebrafish embryos in vivo

    International Nuclear Information System (INIS)

    In the present work, the influence of a low concentration of exogenous carbon monoxide (CO) liberated from tricarbonylchloro(glycinato)ruthenium (II) (CORM-3) on the radiation induced bystander effect (RIBE) in vivo between embryos of the zebrafish was studied. RIBE was assessed through the number of apoptotic signals revealed on embryos at 25 h post fertilization (hpf). A significant attenuation of apoptosis on the bystander embryos induced by RIBE in a CO concentration dependent manner was observed. - Highlights: ► RIBE between zebrafish embryos in vivo was assessed by the level of apoptosis. ► CO from 10 and 20 μM CORM-3 entirely suppressed the RIBE. ► CO from 5 μM CORM-3 significantly attenuated the level of apoptosis. ► Inactive CORM-3 did not lead to suppression of RIBE. ► Suppression of RIBE by CO depended on the concentration of CORM-3.

  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. Study on the adaptive response of mammalian cells induced by low dose radiation of carbon ions

    International Nuclear Information System (INIS)

    The effect of high LET carbon ions irradiation with low dose on V79 Chinese hamster cells and B16 melanoma cells were investigated. The cells were treated with inducing doses of 0.02 Gy and 0.05 Gy first, and then with challenge dose of 1 Gy after-additional culture of 4h. The adaptive responses including survival fraction and micronucleus frequency were studied. Authors' results showed that when the inducing dose was chosen as 0.02 Gy, there were marked increase of surviving fraction and decrease of micronucleus frequency in both cell lines. On the contrary, when the inducing dose was chosen as 0.05 Gy, there was no statistical change of surviving fraction, furthermore, the micronucleus frequency increased a little. This meant that high LET radiation of 0.02 Gy could induce the adaptive response of cultured cells while 0.05 Gy can not. Meanwhile, there was a good linear relationship between micronucleus frequency and surviving fraction, cells pre-exposed to low dose such as 0.02 Gy had low micronucleus frequency and high surviving fraction

  7. 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.

  8. 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.

  9. Flow induced vibration and stability analysis of multi wall carbon nanotubes

    International Nuclear Information System (INIS)

    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

  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. 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.

  12. 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.

  13. Laser-induced breakdown spectroscopy analysis of minerals: Carbonates and silicates

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy (LIBS) provides an alternative chemical analytical technique that obviates the issues of sample preparation and sample destruction common to most laboratory-based analytical methods. This contribution explores the capability of LIBS analysis to identify carbonate and silicate minerals rapidly and accurately. Fifty-two mineral samples (18 carbonates, 9 pyroxenes and pyroxenoids, 6 amphiboles, 8 phyllosilicates, and 11 feldspars) were analyzed by LIBS. Two composite broadband spectra (averages of 10 shots each) were calculated for each sample to produce two databases each containing the composite LIBS spectra for the same 52 mineral samples. By using correlation coefficients resulting from the regression of the intensities of pairs of LIBS spectra, all 52 minerals were correctly identified in the database. If the LIBS spectra of each sample were compared to a database containing the other 51 minerals, 65% were identified as a mineral of similar composition from the same mineral family. The remaining minerals were misidentified for two reasons: 1) the mineral had high concentrations of an element not present in the database; and 2) the mineral was identified as a mineral with similar elemental composition from a different family. For instance, the Ca-Mg carbonate dolomite was misidentified as the Ca-Mg silicate diopside. This pilot study suggests that LIBS has promise in mineral identification and in situ analysis of minerals that record geological processes

  14. 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.

  15. 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

  16. 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

  17. Heavy duty piezoresistivity induced strain sensing natural rubber/carbon black nanocomposites reinforced with different carbon nanofillers

    Science.gov (United States)

    He, Qingliang; Yuan, Tingting; Zhang, Xi; Guo, Shimei; Liu, Jingjing; Liu, Jiurong; Liu, Xinyu; Sun, Luyi; Wei, Suying; Guo, Zhanhu

    2014-09-01

    Durable piezoresistive effects of natural rubber nanocomposites have been demonstrated, i.e., with stable and reversible electrical resistance change within the tested 3000 cycles upon applying a small compressive strain (˜16.7%) under a relatively high frequency (0.5 Hz, 2 s/cycle). This unique function was achieved for the first time by combining carbon nanotubes and carbon nanofibers with natural rubber composites pretreated with carbon black. Even though the combination of different carbon nanomaterials, such as graphene nanosheets and carbon nanotubes, can improve the dispersion quality of both the nanostructures in solution or in polymer matrices, this type of synergistic effect between carbon nanotubes and carbon nanofibers in producing stable and reversible piezoresistive effect has been rarely reported. Besides, the strong reinforcement (compressive stress at a maximum strain of 16.7% was increased from 12.6 for untreated to 18.5 MPa for the natural rubber/carbon black composites treated with a combination of 1.0 wt% carbon nanotubes and 1.0 wt% carbon nanofibers) makes the as-prepared composites promising for heavy duty pressure sensors, i.e., healthy motion monitoring of industrial machinery vibrations.

  18. Effects of CO2-induced changes in seawater carbonate chemistry speciation on Coccolithus braarudii: a conceptual model of coccolithophorid sensitivities

    Directory of Open Access Journals (Sweden)

    U. Riebesell

    2010-12-01

    Full Text Available Ocean acidification and associated shifts in carbonate chemistry speciation induced by increasing levels of atmospheric carbon dioxide (CO2 have the potential to impact marine biota in various ways. The process of biogenic calcification, for instance, is usually shown to be negatively affected. In coccolithophores, an important group of pelagic calcifiers, changes in cellular calcification rates in response to changing ocean carbonate chemistry appear to differ among species. By applying a wider CO2 range we show that a species previously reported insensitive to seawater acidification, Coccolithus braarudii, responds both in terms of calcification and photosynthesis, although at higher thresholds. Thus, observed differences between species seem to be related to individual sensitivities while the underlying mechanisms could be the same. On this basis we develop a conceptual model of coccolithophorid calcification and photosynthesis in response to CO2-induced changes in seawater carbonate chemistry speciation.

  19. 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

  20. Impact of nitrogenous fertiliser-induced proton release on cultivated soils with contrasting carbonate contents: A column experiment

    OpenAIRE

    Gandois, Laure; Perrin, Anne-Sophie; Probst, Anne

    2010-01-01

    An experimental study was carried out in order to evaluate the impact of nitrogen fertiliser-induced acidification in carbonated soils. Undisturbed soil columns containing different carbonate content were sampled in the field. Fertiliser spreading was simulated by NH4Cl addition on top of the soil column. Soil solution composition (mainly nitrate and base cations) was studied at the soil column’s base. Nitrification occurred to a different extent depending on soil type. Higher nitrification r...

  1. 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...

  2. 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

  3. 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

  4. 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

  5. Elastic-resilience-induced dispersion of carbon nanotubes: a novel way of fabricating high performance elastomer

    Science.gov (United States)

    Wu, Siwu; Lin, Tengfei; Guo, Baochun

    2013-11-01

    State-of-the-art processes cannot achieve rubber/multi-walled carbon nanotube (MWCNT) composites with satisfactory performance by using pristine MWCNTs and conventional processing equipment. In this work, high performance rubber/MWCNT composites featuring a combination of good mechanical properties, electrical and thermal conductivities and damping capacity over a wide temperature range are fabricated based on a well-developed master batch process. It is demonstrated that the MWCNTs are dispersed homogeneously due to the disentanglement induced by well-wetting and shearing, and the elastic-resilience-induced dispersion of the MWCNTs by rubber chains via the novel processing method. To further enhance the efficacy of elastic-resilience-induced dispersion for MWCNTs, a slightly pre-crosslinked network is constructed in the master batch. Consequently, we obtain rubber/MWCNT composites with unprecedented performance by amplifying the reinforcing effect of relatively low MWCNT loading. This work provides a novel insight into the fabrication of high performance functional elastomeric composites with pristine CNTs by taking advantage of the unique elastic resilience of rubber chains as the driving force for the disentanglement of CNTs.

  6. Elastic-resilience-induced dispersion of carbon nanotubes: a novel way of fabricating high performance elastomer

    International Nuclear Information System (INIS)

    State-of-the-art processes cannot achieve rubber/multi-walled carbon nanotube (MWCNT) composites with satisfactory performance by using pristine MWCNTs and conventional processing equipment. In this work, high performance rubber/MWCNT composites featuring a combination of good mechanical properties, electrical and thermal conductivities and damping capacity over a wide temperature range are fabricated based on a well-developed master batch process. It is demonstrated that the MWCNTs are dispersed homogeneously due to the disentanglement induced by well-wetting and shearing, and the elastic-resilience-induced dispersion of the MWCNTs by rubber chains via the novel processing method. To further enhance the efficacy of elastic-resilience-induced dispersion for MWCNTs, a slightly pre-crosslinked network is constructed in the master batch. Consequently, we obtain rubber/MWCNT composites with unprecedented performance by amplifying the reinforcing effect of relatively low MWCNT loading. This work provides a novel insight into the fabrication of high performance functional elastomeric composites with pristine CNTs by taking advantage of the unique elastic resilience of rubber chains as the driving force for the disentanglement of CNTs. (paper)

  7. 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.

  8. Elastic-resilience-induced dispersion of carbon nanotubes: a novel way of fabricating high performance elastomer.

    Science.gov (United States)

    Wu, Siwu; Lin, Tengfei; Guo, Baochun

    2013-11-22

    State-of-the-art processes cannot achieve rubber/multi-walled carbon nanotube (MWCNT) composites with satisfactory performance by using pristine MWCNTs and conventional processing equipment. In this work, high performance rubber/MWCNT composites featuring a combination of good mechanical properties, electrical and thermal conductivities and damping capacity over a wide temperature range are fabricated based on a well-developed master batch process. It is demonstrated that the MWCNTs are dispersed homogeneously due to the disentanglement induced by well-wetting and shearing, and the elastic-resilience-induced dispersion of the MWCNTs by rubber chains via the novel processing method. To further enhance the efficacy of elastic-resilience-induced dispersion for MWCNTs, a slightly pre-crosslinked network is constructed in the master batch. Consequently, we obtain rubber/MWCNT composites with unprecedented performance by amplifying the reinforcing effect of relatively low MWCNT loading. This work provides a novel insight into the fabrication of high performance functional elastomeric composites with pristine CNTs by taking advantage of the unique elastic resilience of rubber chains as the driving force for the disentanglement of CNTs. PMID:24164916

  9. 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.

  10. 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.

  11. 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

  12. Study by X-ray diffraction of structure modifications induced by pressure in different actinide compounds: AnO2 dioxides (An=Th, Pu, Am), AnCl4 tetrachlorides (An=Th, U), UBx borides (x=2,4,12) and the carbide UC2

    International Nuclear Information System (INIS)

    Structural transitions, induced by pressure, of actinide compounds are studied by X-ray diffraction, the determination of incompressibility is also studied at atmospheric pressure. The crystal structure of ThO2, PuO2 and AmO2 evolves, near 40 MPa from a fcc lattice to an orthorhombic lattice. Incompressibility values associated to UO2 and NpO2 incompressibility evidence an important discontinuity between UO2 and NpO2 and other dioxides due to their different electronic structure. Tetragonal ThCl4 and UCl4 undergo a structure transition respectively at 2 and 5 GPa. UCl4 becomes monoclinic and its color changes. At higher pressure these compounds become progressively amorphous. The crystal structure of uranium borides is not changed up to 50 GPa. UC2 presents a phase transition at 17.6 GPa from a tetragonal to a hexagonal lattice

  13. 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.

  14. Anti-oxidative and inflammatory responses induced by fly ash particles and carbon black in lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Diabate, Silvia; Plaumann, Diana; Uebel, Caroline; Weiss, Carsten [Karlsruhe Institute of Technology, Institute of Toxicology and Genetics, Eggenstein-Leopoldshafen (Germany); Bergfeldt, Britta [Karlsruhe Institute of Technology, Institute of Technical Chemistry, Eggenstein-Leopoldshafen (Germany)

    2011-12-15

    Combustion-derived nanoparticles as constituents of ambient particulate matter have been shown to induce adverse health effects due to inhalation. However, the components inducing these effects as well as the biological mechanisms are still not fully understood. The fine fraction of fly ash particles collected from the electrostatic precipitator of a municipal solid waste incinerator was taken as an example for real particles with complex composition released into the atmosphere to study the mechanism of early biological responses of BEAS-2B human lung epithelial cells. The studies include the effects of the water-soluble and -insoluble fractions of the fly ash and the well-studied carbon black nanoparticles were used as a reference. Fly ash induced reactive oxygen species (ROS) and increased the total cellular glutathione (tGSH) content. Carbon black also induced ROS generation; however, in contrast to the fly ash, it decreased the intracellular tGSH. The fly ash-induced oxidative stress was correlated with induction of the anti-oxidant enzyme heme oxygenase-1 and increase of the redox-sensitive transcription factor Nrf2. Carbon black was not able to induce HO-1. ROS generation, tGSH increase and HO-1 induction were only induced by the insoluble fraction of the fly ash, not by the water-soluble fraction. ROS generation and HO-1 induction were markedly inhibited by pre-incubation of the cells with the anti-oxidant N-acetyl cysteine which confirmed the involvement of oxidative stress. Both effects were also reduced by the metal chelator deferoxamine indicating a contribution of bioavailable transition metals. In summary, both fly ash and carbon black induce ROS but only fly ash induced an increase of intracellular tGSH and HO-1 production. Bioavailable transition metals in the solid water-insoluble matrix of the fly ash mostly contribute to the effects. (orig.)

  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. 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).'

  17. Removal of technetium, carbon tetrachloride, and metals from DOE properties. 1998 annual progress report

    International Nuclear Information System (INIS)

    '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 TcO2 , 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).'

  18. 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)

  19. 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

  20. 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

  1. Carbon Tetrachloride and Chloroform Partition Coefficients Derived from Aqueous Desorption of Contaminated Hanford Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert G.; Sklarew, Debbie S.; Brown, Christopher F.; Gent, Philip M.; Szecsody, Jim E.; Mitroshkov, Alexandre V.; Thompson, Christopher J.

    2005-07-08

    Researchers at PNNL determined CCl4 and CHCl3 groundwater/sediment partition coefficients (Kd values) for contaminated aquifer sediments collected from borehole C3246 (299-W15-46) located in the 200 West Area adjacent to the Z-9 trench. Having realistic values for this parameter is critical to predict future movement of CCl4 in groundwater from the 200 West Area.

  2. GO-induced assembly of gelatin toward stacked layer-like porous carbon for advanced supercapacitors

    Science.gov (United States)

    Zhang, Xiaomeng; Jiao, Yanqing; Sun, Li; Wang, Lei; Wu, Aiping; Yan, Haijing; Meng, Meichen; Tian, Chungui; Jiang, Baojiang; Fu, Honggang

    2016-01-01

    Layer-like nanocarbons with high surface area and good conductivity are promising materials for supercapacitors due to their good ability for effective charge-transfer and mass-transfer. In this paper, stacked layer-like porous carbon containing RGO (reduced graphene oxides) (LPCG) was constructed via the GO-induced assembly of gelatin followed by carbonization and activation processes. Under suitable conditions, LPCG-based materials with a thickness of about 100 nm and a high specific surface area (up to 1476 m2 g-1) could be obtained. In the materials, the closed combination of RGO and porous carbon can be observed, which is favourable for the development of the synergistic effects of both components. The presence of GO can not only enhance the conductivity of LPCG-based materials, but also is essential for the formation of a thin carbon sheet with a stacked structure. Otherwise, the plate-like, non-stacked carbon with a thickness of about 500 nm could be formed in the absence of RGO. The porous structure along with the presence of RGO allows rapid charge-transfer and easy access and diffusion of electrolyte ions. As a result, the materials exhibited a high discharge specific capacitance (455 F g-1 at 0.5 A g-1, 366 F g-1 at 1 A g-1), good rate capability (221 F g-1 at density 30 A g-1) and good cycling stability. In aqueous electrolytes, the energy density could be up to 9.32 W h kg-1 at a relatively low power density of 500 W kg-1 with a good cycling stability (>96% over 5000 cycles). It was found that (1) the rational combination of RGO and porous carbon is essential for enhancing the capacitance performance and improving the cycling stability and (2) the high conductivity is favorable for improving the rate performance of the materials. The LPCG-based materials have extensive potential for practical applications in energy storage and conversion devices.Layer-like nanocarbons with high surface area and good conductivity are promising materials for

  3. Disproportionation of zirconium and hafnium hydroxochlorides to tetrachlorides in the presence of dimethylsulfoxide

    International Nuclear Information System (INIS)

    Interaction of zirconium and hafnium hydroxochlorides with dimethylsulfoxide (DMSO) has been studied. It is shown, that the formation of coordination compounds of zirconium and hafnium tetrachlorides with DMSO in 96% ethanol solution with the yield 4x9DMSO (M - Zr, Hf) are well soluble in water and ethanol, they are hydrolyzed in the air. Melting points of both compounds are equal to 68 deg. On the basis of IR-spectroscopy data it has been shown, that DMSO coordination by zirconium and hafnium atoms takes place via sulphur atom of ligand molecule

  4. 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.

  5. 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

  6. 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

  7. Concentration gradient induced morphology evolution of silica nanostructure growth on photoresist-derived carbon micropatterns

    Science.gov (United States)

    Liu, Dan; Shi, Tielin; Xi, Shuang; Lai, Wuxing; Liu, Shiyuan; Li, Xiaoping; Tang, Zirong

    2012-09-01

    The evolution of silica nanostructure morphology induced by local Si vapor source concentration gradient has been investigated by a smart design of experiments. Silica nanostructure or their assemblies with different morphologies are obtained on photoresist-derived three-dimensional carbon microelectrode array. At a temperature of 1,000°C, rope-, feather-, and octopus-like nanowire assemblies can be obtained along with the Si vapor source concentration gradient flow. While at 950°C, stringlike assemblies, bamboo-like nanostructures with large joints, and hollow structures with smaller sizes can be obtained along with the Si vapor source concentration gradient flow. Both vapor-liquid-solid and vapor-quasiliquid-solid growth mechanisms have been applied to explain the diverse morphologies involving branching, connecting, and batch growth behaviors. The present approach offers a potential method for precise design and controlled synthesis of nanostructures with different features.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. Preparation and characterization of activated carbon from pistachio nut shells via microwave-induced chemical activation

    International Nuclear Information System (INIS)

    In this work, pistachio nut shell, a biomass residue abundantly available from the pistachio nut processing industries, was utilized as a feedstock for the preparation of activated carbon (PSAC) via microwave assisted KOH activation. The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. The porosity, functional and surface chemistry were featured by means of low temperature nitrogen adsorption, scanning electron microscopy and Fourier transform infrared spectroscopy. Result showed that the BET surface area, Langmuir surface area, and total pore volume of PSAC were 700.53 m2 g-1, 1038.78 m2 g-1 and 0.375 m3 g-1, respectively. The adsorptive property of PSAC was tested using methylene blue dye as the targeted adsorbate. Equilibrium data was best fitted by the Langmuir isotherm model, showing a monolayer adsorption capacity of 296.57 mg g-1. The study revealed the potentiality of microwave-induced activation as a viable activation method. -- Highlights: → Pistachio nut shell activated carbon (PSAC) was prepared via microwave assisted KOH activation. → The activation step was performed at the microwave input power of 600 W and irradiation time of 7 min. → BET surface area of PSAC was 700.53 m2/g. → Monolayer adsorption capacity of PSAC for MB was 296.57 mg/g.

  15. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements.

    Energy Technology Data Exchange (ETDEWEB)

    Peng, B.; Locascio, M.; Zapol, P.; Li, S.; Mielke, S. L.; Schatz, G. C.; Espinosa, H. D.; Northwestern Univ.

    2008-01-01

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are {approx}80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  16. Measurements of near-ultimate strength for multiwalled carbon nanotubes and irradiation-induced crosslinking improvements

    International Nuclear Information System (INIS)

    The excellent mechanical properties of carbon nanotubes are being exploited in a growing number of applications from ballistic armour to nanoelectronics. However, measurements of these properties have not achieved the values predicted by theory due to a combination of artifacts introduced during sample preparation and inadequate measurements. Here we report multiwalled carbon nanotubes with a mean fracture strength >100 GPa, which exceeds earlier observations by a factor of approximately three. These results are in excellent agreement with quantum-mechanical estimates for nanotubes containing only an occasional vacancy defect, and are ∼80% of the values expected for defect-free tubes. This performance is made possible by omitting chemical treatments from the sample preparation process, thus avoiding the formation of defects. High-resolution imaging was used to directly determine the number of fractured shells and the chirality of the outer shell. Electron irradiation at 200 keV for 10, 100 and 1,800 s led to improvements in the maximum sustainable loads by factors of 2.4, 7.9 and 11.6 compared with non-irradiated samples of similar diameter. This effect is attributed to crosslinking between the shells. Computer simulations also illustrate the effects of various irradiation-induced crosslinking defects on load sharing between the shells.

  17. Tree ring carbon isotopes record predisposition to drought-induced mortality and survival.

    Science.gov (United States)

    McDowell, N.; Allen, C.; Levanič, T.; Marshall, L.

    2009-04-01

    Drought-induced tree mortality is predicted to increase in intensity and frequency in mid-latitude regions over the next 50 years. We report on tree ring records of growth and carbon isotope discrimination in a variety of species from N. America and Europe that demonstrate a consistent pattern of predisposition to mortality during drought. Trees that die show greater sensitivity of growth to climate as has been previously demonstrated. Trees that die; however, have consistently lower discrimination and significantly less sensitivity of discrimination to climate than trees that survive. A simple hydraulic model based on Darcy's law successfully recreated the observed patterns of discrimination, and supports the interpretation that trees that die have consistently lower leaf-level stomatal conductance than trees that survive. Furthermore, the model supports the conclusion that these trees are less responsive to inter-annual climate variation due to chronic water stress. It appears that such chronic water stress predisposes trees to mortality. Consideration of the sensitivity of these isotope records to mesophyll conductance, photosynthetic capacity, photorespiration, and carbon recyling is critical to robust conclusions. Continued intensification of drought in mid-latitude regions may force trees undergoing chronic water stress to undergo increased mortality, resulting in ecotone shifts and regional mortality events in temperate forests.

  18. 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

  19. Damage induced by proton irradiation in carbonate based natural painting pigments

    Energy Technology Data Exchange (ETDEWEB)

    Enguita, Olga E-mail: olga.enguita@uam.es; Calderon, T.; Fernandez-Jimenez, M.T.; Beneitez, P.; Millan, A.; Garcia, G

    2004-06-01

    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.

  20. 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