WorldWideScience

Sample records for carbon tetrachloride

  1. Detection of carbon tetrachloride associates in isooctane

    Science.gov (United States)

    Byakov, V. M.; Lanshina, L. V.; Stepanova, O. P.; Stepanov, S. V.

    2010-07-01

    The cryoscopic and radiospectroscopic data revealed that carbon tetrachloride (CCl4) n agglomerates ( n ≥ 4) could form in cyclohexane and carbon tetrachloride itself. Additional arguments in favor of the formation of similar CCl4 agglomerates in isooctane were presented by analyzing the available data on positron annihilation in CCl4 solutions in isooctane.

  2. 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/carbon...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 ...

  3. Emissions of carbon tetrachloride from Europe

    Science.gov (United States)

    Graziosi, Francesco; Arduini, Jgor; Bonasoni, Paolo; Furlani, Francesco; Giostra, Umberto; Manning, Alistair J.; McCulloch, Archie; O'Doherty, Simon; Simmonds, Peter G.; Reimann, Stefan; Vollmer, Martin K.; Maione, Michela

    2016-10-01

    Carbon tetrachloride (CCl4) is a long-lived radiatively active compound with the ability to destroy stratospheric ozone. Due to its inclusion in the Montreal Protocol on Substances that Deplete the Ozone Layer (MP), the last two decades have seen a sharp decrease in its large-scale emissive use with a consequent decline in its atmospheric mole fractions. However, the MP restrictions do not apply to the use of carbon tetrachloride as feedstock for the production of other chemicals, implying the risk of fugitive emissions from the industry sector. The occurrence of such unintended emissions is suggested by a significant discrepancy between global emissions as derived from reported production and feedstock usage (bottom-up emissions), and those based on atmospheric observations (top-down emissions). In order to better constrain the atmospheric budget of carbon tetrachloride, several studies based on a combination of atmospheric observations and inverse modelling have been conducted in recent years in various regions of the world. This study is focused on the European scale and based on long-term high-frequency observations at three European sites, combined with a Bayesian inversion methodology. We estimated that average European emissions for 2006-2014 were 2.2 (± 0.8) Gg yr-1, with an average decreasing trend of 6.9 % per year. Our analysis identified France as the main source of emissions over the whole study period, with an average contribution to total European emissions of approximately 26 %. The inversion was also able to allow the localisation of emission "hot spots" in the domain, with major source areas in southern France, central England (UK) and Benelux (Belgium, the Netherlands, Luxembourg), where most industrial-scale production of basic organic chemicals is located. According to our results, European emissions correspond, on average, to 4.0 % of global emissions for 2006-2012. Together with other regional studies, our results allow a better constraint

  4. [Carbon tetrachloride poisoning: a report of 3 cases].

    Science.gov (United States)

    Casas, E; Martínez Ara, J; Valencia, M E; Mostaza, J M; Miguel, J L; Sánchez Sicilia, L

    1989-09-01

    Carbon tetrachloride is a toxic solvent easily obtained in our country. 3 cases of poisoning by accidental inhalation at place of work. The main clinical manifestations were acute renal failure and toxic hepatopathy. All patients, had a good evolution with dialysis therapy after a few weeks. We comment on some possible additional therapies to be used in treating patients with severe poisoning due to carbon tetrachloride.

  5. 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.

  6. Analytical methods for the determination of carbon tetrachloride in soils.

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, J. S.; Spokas, K.; Taylor, J.

    1999-06-01

    Improved methods for the determination of carbon tetrachloride are described. These methods incorporate purge-and-trap concentration of heated dry samples, an improved methanol extraction procedure, and headspace sampling. The methods minimize sample pretreatment, accomplish solvent substitution, and save time. The methanol extraction and headspace sampling procedures improved the method detection limits and yielded better sensitivity, good recoveries, and good performance. Optimization parameters are shown. Results obtained with these techniques are compared for soil samples from contaminated sites.

  7. Mechanism underlying carbon tetrachloride-inhibited protein synthesis in liver

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM: To study the mechanism underlying carbon tetrachloride (CCl4)-induced alterations of protein synthesis in liver. METHODS: Male Sprague-Dawley rats were given CCl4 (1 mL/100 g body weight) and 3H-leucine incorporation. Malondialdehyde (MDA) level in the liver, in vitro response of hepatocyte nuclei nucleotide triphosphatase (NTPase) to free radicals, and nuclear export of total mRNA with 3'-poly A+ were measured respectively. Survival response of HepG2 cells to CCl4 treatment was assessed by methyl thia...

  8. 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.

  9. 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.

  10. Recent Site-Wide Transport Modeling Related to the Carbon Tetrachloride Plume at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    Bergeron, Marcel P.; Cole, C R.

    2005-11-01

    Carbon tetrachloride transport in the unconfined aquifer system at the Hanford Site has been the subject of follow-on studies since the Carbon Tetrachloride Innovative Treatment Remediation Demonstration (ITRD) Program was completed in FY 2002. These scoping analyses were undertaken to provide support for strategic planning and guidance for the more robust modeling needed to obtain a final record of decision (ROD) for the carbon tetrachloride plume in the 200 West Area. This report documents the technical approach and the results of these follow-on, site-wide scale-modeling efforts. The existing site-wide groundwater model was used in this effort. The work extended that performed as part of the ITRD modeling study in which a 200 West Area scale submodel was developed to examine arrival concentrations at an arbitrary boundary between the 200 E and 200 W areas. These scoping analyses extended the analysis to predict the arrival of the carbon tetrachloride plume at the Columbia River. The results of these analyses illustrate the importance of developing field-scale estimates of natural attenuation parameters, abiotic degradation rate and soil/water equilibrium sorption coefficient, for carbon tetrachloride. With these parameters set to zero, carbon tetrachloride concentrations will exceed the compliance limit of 5 ?g/L outside the 200 Area Plateau Waste Management Area, and the aquifer source loading and area of the aquifer affected will continue to grow until arrival rates of carbon tetrachloride equal source release rates, estimated at 33 kg/yr. Results of this scoping analysis show that the natural attenuation parameters are critical in predicting the future movement of carbon tetrachloride from the 200 West Area. Results also show the significant change in predictions between continual source release from the vadose zone and complete source removal.

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

    Directory of Open Access Journals (Sweden)

    Antony B

    2006-01-01

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

  12. Telmisartan ameliorates carbon tetrachloride-induced acute hepatotoxicity in rats.

    Science.gov (United States)

    Atawia, Reem T; Esmat, Ahmed; Elsherbiny, Doaa A; El-Demerdash, Ebtehal

    2017-02-01

    This study assessed the potential hepatoprotective effect of telmisartan (TLM), a selective angiotensin II type 1 (AT1 ) receptor blocker, on carbon tetrachloride (CCl4 )-induced acute hepatotoxity in rats. Intraperitoneal injection of male Wistar rats with CCl4 1 mL kg(-1) , 1:1 mixture with corn oil for 3 days increased serum alanine transaminase, aspartate transaminase, and alkaline phosphatase activities as well as total bilirubin, triglycerides and total cholesterol levels. This is in addition to the disrupted histological architecture in the CCl4 group. Rats receiving CCl4 and co-treated with TLM (3 and 10 mg kg(-1) , orally) showed ameliorated serum biochemical and histological changes almost to the control level. Nevertheless, rats treated with TLM (1 mg kg(-1) ) didn't show any significant changes compared to CCl4 intoxicated group. In addition, TLM rectified oxidative status disrupted by CCl4 intoxication. Interestingly, TLM protected against CCl4 -induced expressions of nuclear factor-κB, inducible nitric oxide synthase and cyclooxygenase-II, in a dose related manner. Moreover, TLM (3 and 10 mg kg(-1) ) significantly modified CCl4 -induced elevation in tumor necrosis factor-α and nitric oxide levels. Furthermore, TLM showed a marked decline in CD68+ cells stained areas and reduced activity of myeloperoxidase enzyme compared to CCl4 -intoxicated group. In conclusion, both doses of TLM (3 and 10 mg kg(-1) ) showed significant hepato-protective effects. However, TLM at a dose of 10 mg kg(-1) didn't show significant efficacy above 3 mg kg(-1) which is nearly equivalent to the human anti-hypertensive dose of 40 mg. Thus, may be effective in guarding against several hepatic complications due to its antioxidant and anti-inflammatory activities. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 359-370, 2017.

  13. Carbon tetrachloride-induced hepatotoxicity in pregnant and lactating rats.

    Science.gov (United States)

    Mochizuki, Masahiro; Shimizu, Satomi; Urasoko, Yoshinaka; Umeshita, Kazuhiko; Kamata, Takashi; Kitazawa, Takahiro; Nakamura, Daichi; Nishihata, Yoshito; Ohishi, Takumi; Edamoto, Hiroshi

    2009-04-01

    Carbon tetrachloride (CCl4) is well known to induce hepatotoxicity after being metabolized to trichloromethyl free radical ((.)CCl3) by CYP2E1. In the present study, the hepatotoxicity induced by a single oral dose (2,000 mg/kg) of CCl4 was compared between pregnant (gestation days (GD) 13 and 19) or postpartum (postpartum days (PPD) 1, 13 and 27) and non-pregnant rats. Hepatotoxicity in CCl4-treated pregnant rats evaluated by blood chemistry (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities) and histopathological finding (area of damaged hepatocytes) was minimal on GD19, being weaker than that in non-pregnant rats. CYP2E1 expression in non-treated pregnant rats decreased as pregnancy progressed and reached minimum level on GD19. Thus, the degree of CCl4-induced hepatotoxicity roughly corresponded to CYP2E1 levels during pregnancy. After delivery, hepatotoxicity in CCl4-treated lactating rats was maximal on PPD13, being stronger than that in non-pregnant rats, and then it decreased slightly on PPD27. The CYP2E1 level in the non-treated lactating rats tended to increase but remained at lower levels until PPD13 compared with that in non-pregnant rats. Thus, the degree of CCl4-induced hepatotoxicity did not correspond to CYP2E1 levels during lactation. This suggests that during lactation, there may be certain factors other than CYP2E1 expression responsible for the degree of CCl4-induced hepatotoxicity.

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

    Science.gov (United States)

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

    2016-04-01

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

  15. 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).

  16. 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.

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

    NARCIS (Netherlands)

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

    1979-01-01

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

  18. 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

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Science.gov (United States)

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

    2002-11-01

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

  1. 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

  2. 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.

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    AK Azeem; Molly Mathew; Chandramohan Nair DilipC

    2010-01-01

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

  5. Observation of the hepatoprotective and antioxidant activities of Trianthema decandra Linn. (Vallai sharunnai roots on carbon tetrachloride-treated rats

    Directory of Open Access Journals (Sweden)

    G. Balamurugan

    2008-06-01

    Full Text Available The present study was carried out to observe the hepatoprotective effect and antioxidant activity of the ethanol extract of the roots of Trianthema decandra Linn. (200 and 400 mg/kg in rats treated with carbon tetrachloride for 8 weeks. Extract at the tested doses restored the levels of all serum (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin and total protein and liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase and catalase significantly. Histology demonstrated profound steatosis degeneration and nodule formation were observed in the hepatic architecture of carbon tetrachloride treated rats which were found to acquire near-normalcy in extract plus carbon tetrachloride administrated rats, and supported the biochemical observations. This study suggests that ethanol extract of T. decandra has a liver protective effect against carbon tetrachloride- induced hepatotoxicity and possess antioxidant activities.

  6. 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.

  7. 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.

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

    Science.gov (United States)

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

    2000-01-01

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

  9. Graphene oxide-mediated rapid dechlorination of carbon tetrachloride by green rust

    DEFF Research Database (Denmark)

    Huang, Li-Zhi; Hansen, Hans Christian B.; Daasbjerg, Kim

    2017-01-01

    Graphene-based nanomaterials can mediate environmentally relevant abiotic redox reactions of chlorinated aliphatic hydrocarbons. In this study as low amounts as ∼0.007 % of graphene oxide (GO) was found to catalyze the reduction of carbon tetrachloride by layered Fe(II)-Fe(III) hydroxide (Green....... This study indicates that traces of graphene oxide can affect reaction pathways as well as kinetics for dechlorination processes in anoxic sediments by facilitating a partial dechlorination....

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  11. Amelioration of carbon tetrachloride induced hepatotoxicity in rats by standardized Feronia limonia. Linn leaf extracts

    OpenAIRE

    Devkar, Ranjitsinh V; Jadeja, Ravirajsinh N.; Jain, Mahendra; Kapadia, Rakhee; Mishra, S. H.; Menaka C. Thounaojam

    2012-01-01

    The hepatoprotective potential of standardized Feronia limonia (Family, Rutaceae) methanolic extract (FL-7) and chloroform soluble fraction (FL-9) were assessed against carbon tetrachloride (CCl4) induced oxidative stress and hepatotoxicity in rats. Rats treated with CCl4 recorded significant elevation in plasma markers of hepatic injury, alteration in hepatic antioxidant status and histopathological damages. However, rats pretreated with FL-7 (200 or 400 mg/kg, p.o.) and FL-9 (100 or 200 mg/...

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

    Science.gov (United States)

    Cheng, Ni; Wu, Liming; Zheng, Jianbin; Cao, Wei

    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 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. PMID:26508989

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-03-01

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

  15. A Systematic Approach to In Situ Bioremediation in Groundwater Including Decision Trees on In Situ Bioremediation for Nitrates, Carbon Tetrachloride, and Perchlorate

    Science.gov (United States)

    2002-08-01

    facility also had associated seed treatment operations that may have contributed mercury compounds to the subsurface. The time of the releases will...tetrachloride is a dense nonaqueous-phase liquid ( DNAPL ) that does not occur naturally. The physical properties of carbon tetrachloride and its most...et al., 2001). DOE’s Y-12 Plant in Oak Ridge, Tennessee has an historical carbon tetrachloride plume with suspected DNAPL in fractured bedrock (see

  16. 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

  17. Hepatoprotective activity of Ficus carica Linn leaf extract against carbon tetrachloride-induced hepatotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Mohan G.K.

    2007-06-01

    Full Text Available The methanol extract of the leaves of Ficus carica Linn. (Moraceae was evaluated for hepatoprotective activity in rats with liver damage induced by carbon tetrachloride. The extract at an oral dose of 500 mg/kg exhibited a significant protective effect by lowering the serum levels of aspartate aminotransferase, alanine aminotransferase, total serum bilirubin, and malondialdehyde equivalent, an index of lipid peroxidation of the liver. These biochemical observations were supplemented by histopathological examination of liver sections. The activity of extract was also comparable to that of silymarin, a known hepatoprotective. 

  18. Sesamin ameliorates oxidative liver injury induced by carbon tetrachloride in rat

    OpenAIRE

    Lv, Dan; Zhu, Chang-Qing; Liu, Li

    2015-01-01

    Sesamin is naturally occurring lignan from sesame oil with putative antioxidant property. The present study was designed to investigate the protective role of sesamin against carbon tetrachloride induced oxidative liver injury. Male Wistar albino rats (180-200 g) were divided in to 5 groups (n=6). Hepatotoxicity was induced by the administration of CCl4 (0.1 ml/100 g bw., 50% v/v with olive oil) intraperitoneally. Sesamin was administered in two different dose (5 and 10 ml/kg bw) to evaluate ...

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

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

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

  20. Thermal diffusion factor for carbon tetrachloride-cyclohexane and benzene-n-heptane mixtures from thermogravitational column separation

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, J.L.; Madariaga, J.A.; Santamaria, C.M.; Saviron, J.M.; Carrion, J.A.

    1985-01-01

    Measurements of the separation of liquid mixtures of n-heptane/benzene and carbon tetrachloride/cyclohexane in a thermogravitational column are reported. The results show that thermal diffusion columns of little mechanical precision can furnish suitable thermal diffusion factors when the diffusion coefficient, viscosity, density, and compressibility factor for the mixture are known. 23 references, 3 figures, 1 table.

  1. HEPATOPROTECTIVE ACTIVITY OF ALSTONIA SCHOLARIS FRUITS AGAINST CARBON TETRACHLORIDE-INDUCED HEPATOTOXICITY IN RATS

    Directory of Open Access Journals (Sweden)

    K. RAVI SHANKAR, A. LAKSHMANA RAO, L. KALYANI

    2013-09-01

    Full Text Available The hepatoprotective activity of ethanolic extract of fruits of Alstonia scholaris was evaluated by carbon tetrachloride (CCL4-induced hepatotoxicity in rats. The toxicant CCL4 was used to induce hepatotoxicity at a dose of 2 ml/kg as 1:1 mixture with olive oil. The ethanolic extract of fruits of Alstonia scholaris was administered in the dose of 150 and 300 mg/kg/day orally for 5 days. Silymarin (50 mg/kg was used as standard drug. The hepatoprotective effect of the ethanolic extract was evaluated by the assessment of biochemical parameters such as SGOT, SGPT, SALKP, total bilirubin and histopathological studies of the liver. Treatment of animals with the ethanolic extract significantly reduced the liver damage and the symptoms of liver injury by restoration of architecture of liver as indicated by lower levels of serum bilirubin as compared with the normal and silymarin treated groups.

  2. 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.

  3. Protective effects of sodium molybdate on carbon tetrachloride-induced hepatotoxicity in rats.

    Science.gov (United States)

    Eidi, Akram; Eidi, Maryam; Al-Ebrahim, Mahsa; Rohani, Ali Haeri; Mortazavi, Pejman

    2011-01-01

    Molybdenum is an essential trace micronutrient element that plays an important role in animal and plant physiology. Molybdenum is a constituent of at least three mammalian metalloflavoproteins: xanthine oxidase, aldehyde oxidase and sulphite oxidase. In the present study, the hepatoprotective potential of sodium molybdate was investigated against carbon tetrachloride (CCl(4))-induced liver damage in rats. Administration of CCl(4) increased the serum alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase levels in rats and reduced levels of the antioxidant enzymes superoxide dismutase and catalase in the liver. Treatment with sodium molybdate significantly attenuated these changes to nearly undetectable levels. The histopathological changes induced by CCl(4) were also significantly attenuated by sodium molybdate treatment. Therefore, the results of this study suggest that sodium molybdate can protect the liver against CCl(4)-induced oxidative damage in rats, and this hepatoprotective effect might be attributable to its modulation of detoxification enzymes and/or its antioxidant and free radical scavenger effects.

  4. Carbon tetrachloride-induced hepatic and renal damages in rat: inhibitory effects of cacao polyphenol.

    Science.gov (United States)

    Suzuki, Koichiro; Nakagawa, Kiyotaka; Yamamoto, Takayuki; Miyazawa, Taiki; Kimura, Fumiko; Kamei, Masanori; Miyazawa, Teruo

    2015-01-01

    Here, we investigated the protective effect of cacao polyphenol extract (CPE) on carbon tetrachloride (CCl4)-induced hepato-renal oxidative stress in rats. Rats were administered CPE for 7 days and then received intraperitoneal injection of CCl4. Two hours after injection, we found that CCl4 treatment significantly increased biochemical injury markers, lipid peroxides (phosphatidylcholine hydroperoxide (PCOOH) and malondialdehyde (MDA)) and decreased glutathione peroxidase activity in kidney rather than liver, suggesting that kidney is more vulnerable to oxidative stress under the present experimental conditions. CPE supplementation significantly reduced these changes, indicating that this compound has antioxidant properties against CCl4-induced oxidative stress. An inhibitory effect of CPE on CCl4-induced CYP2E1 mRNA degradation may provide an explanation for CPE antioxidant property. Together, these results provide quantitative evidence of the in vivo antioxidant properties of CPE, especially in terms of PCOOH and MDA levels in the kidneys of CCl4-treated rats.

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

    Directory of Open Access Journals (Sweden)

    H. G. Khalsa

    1964-01-01

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

  6. Curcuma longa attenuates carbon tetrachloride-induced oxidative stress in T-lymphocyte subpopulations.

    Science.gov (United States)

    Abu-Rizq, H A; Mansour, Mohamed H; Afzal, Mohammad

    2015-01-01

    A comparison of crude curcuminoid extract and purified curcumin was made to evaluate the immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced selective cytolytic effects among immature (PNA(+)) thymocytes and peripheral helper (CD4(+)) T lymphocytes in the spleen were paralleled by a significant reduction in CD25, CD71, and Con A receptor expression. Treatment with curcumanoid crude extract, at two different doses, showed a significant restoration of lymphocyte viability and CD25, CD71, and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4(+)) T lymphocytes. Turmeric crude extract, at both low and high dose, was found to be more efficient as compared to purified curcumin, suggesting synergistic effect of curcumin with other components of the crude extract.

  7. Sesamin ameliorates oxidative liver injury induced by carbon tetrachloride in rat.

    Science.gov (United States)

    Lv, Dan; Zhu, Chang-Qing; Liu, Li

    2015-01-01

    Sesamin is naturally occurring lignan from sesame oil with putative antioxidant property. The present study was designed to investigate the protective role of sesamin against carbon tetrachloride induced oxidative liver injury. Male Wistar albino rats (180-200 g) were divided in to 5 groups (n=6). Hepatotoxicity was induced by the administration of CCl4 (0.1 ml/100 g bw., 50% v/v with olive oil) intraperitoneally. Sesamin was administered in two different dose (5 and 10 ml/kg bw) to evaluate the hepatoprotective activity. Sesamin significantly reduced the elevated serum liver marker enzymes (Psesamin treated groups shows the amelioration of oxidative stress induced by CCl4. Histopathological report also supported the hepatoprotection offered by sesamin. Sesamin effects in both the dose were in comparable to reference standard drug silymarin. From these above findings it has been concluded that sesamin ameliorate the oxidative liver injury in terms of reduction of lipid peroxidation and enhancement of liver antioxidant enzymes.

  8. Amelioration of carbon tetrachloride- and paracetamol-induced hepatotoxicity in rats by Ficus dalhousiae

    Directory of Open Access Journals (Sweden)

    Syed Safiullah Ghori

    2014-12-01

    Full Text Available The present study was undertaken to investigate hepatoprotective activity of Ficus dalhousiae leaves ethanolic extract based on its traditional claim. Paracetamol- and carbon tetrachloride-induced hepatotoxicity in albino Wistar rats, experimental models was used for the evaluation. Various biochemical parameters like SGPT, SGOT, serum albumin, alkaline phosphatase, total bilirubin, direct bilirubin and total protein were estimated. Oral treatment with the extract 250 and 500 mg/kg, significantly (p<0.01 altered all the serum marker levels to the normal in both the experimental models. The activity of the extract was comparable to that of standard drug, silymarin (25 mg/kg, p.o.. Histopathological observations also demonstrated protective effect of the test extract on liver anatomy. Overall results suggest that F. dalhousiae possesses in vivo hepatoprotective activity.

  9. 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.

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

    Science.gov (United States)

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

    2014-09-15

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

  11. Work Plan for a Limited CCC/USDA Investigation of the Current Carbon Tetrachloride Contamination in Groundwater at Navarre, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-05-01

    During private well testing in 1990-1991, carbon tetrachloride was identified in the groundwater at several locations in the town of Navarre, Kansas, at levels exceeding the Kansas Tier 2 level and U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 5.0 μg/L. Several subsequent investigations through 2006 evaluated the concentrations and distribution of carbon tetrachloride in groundwater. This work included the identification of the contaminant sources (Argonne 2007). The history of activities to address the contamination in soil and groundwater is summarized in Table 1.1. The most recent studies, conducted by the Kansas Department of Health and Environment (KDHE), include a brownfields investigation initiated in 2013 (Phase I) and continuing in early 2014 (Phase II), as well as private well testing.

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

    Institute of Scientific and Technical Information of China (English)

    SUN Aijun; ZHANG Jinlong; LI Chunxi; MENG Hong

    2009-01-01

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

  14. HEPATOPROTECTIVE ACTIVITY OF ETHANOLIC EXTRACT OF ALTHAEA OFFICINALIS LINN AGAINST CARBON TETRACHLORIDE INDUCED HEPATOTOXICITY ON ALBINO WISTAR RATS

    OpenAIRE

    Jabbar Zoobi; Ali Mohd.

    2011-01-01

    In Indian traditional system of medicine, herbal remedies are prescribed for the treatment of various diseases including liver diseases. The present study was aimed to investigate the hepatoprotective activity of the ethanolic extract of Althaea officinalis against Carbon tetrachloride induced hepatotoxicity in rats. Liver function were assessed by the determination of SGPT and SGOT studies. The serum biochemical analysis results suggested that the use of ethanolic extract of Althaea officina...

  15. Transcriptome Analysis of the Effects of Gomisin A on the Recovery of Carbon Tetrachloride-Induced Damage in Rat Liver

    OpenAIRE

    Choi, Young Mi; Choi, In Soo; Lee, Sang Mong; Hwang, Dae Youn; Choi, Young Whan; Park, Young Hoon

    2011-01-01

    Gomisin A possesses a hepatic function-facilitating property in liver-injured rats. Its preventive action on carbon tetrachloride-induced cholestasis is due to maintenance of the function of the bile acids-independent fraction. To investigate alterations in gene expression after gomisin A treatment on injured rat liver, DNA microarray analyses were performed on a Rat 44K 4-Plex Gene Expression platform with duplicated reactions after gomisin A treatment. We identified 255 up-regulated and 230...

  16. 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

  17. New and improved infra-red absorption cross sections and ACE-FTS retrievals of carbon tetrachloride (CCl4)

    Science.gov (United States)

    Harrison, Jeremy J.; Boone, Christopher D.; Bernath, Peter F.

    2017-01-01

    Carbon tetrachloride (CCl4) is one of the species regulated by the Montreal Protocol on account of its ability to deplete stratospheric ozone. As such, the inconsistency between observations of its abundance and estimated sources and sinks is an important problem requiring urgent attention (Carpenter et al., 2014) [5]. Satellite remote-sensing has a role to play, particularly limb sounders which can provide vertical profiles into the stratosphere and therefore validate stratospheric loss rates in atmospheric models. This work is in two parts. The first describes new and improved high-resolution infra-red absorption cross sections of carbon tetrachloride/dry synthetic air over the spectral range 700-860 cm-1 for a range of temperatures and pressures (7.5-760 Torr and 208-296 K) appropriate for atmospheric conditions. This new cross-section dataset improves upon the one currently available in the HITRAN and GEISA databases. The second describes a new, preliminary ACE-FTS carbon tetrachloride retrieval that improves upon the v3.0/v3.5 data products, which are biased high by up to 20-30% relative to ground measurements. Making use of the new spectroscopic data, this retrieval also improves the microwindow selection, contains additional interfering species, and utilises a new instrumental lineshape; it will form the basis for the upcoming v4.0 CCl4 data product.

  18. Hepatoprotective effects of Arctium lappa on carbon tetrachloride- and acetaminophen-induced liver damage.

    Science.gov (United States)

    Lin, S C; Chung, T C; Lin, C C; Ueng, T H; Lin, Y H; Lin, S Y; Wang, L Y

    2000-01-01

    The root of Arctium lappa Linne (A. lappa) (Compositae), a perennial herb, has been cultivated for a long time as a popular vegetable. In order to investigate the hepatoprotective effects of A. lappa, male ICR mice were injected with carbon tetrachloride (CCl4, 32 microl/kg, i.p.) or acetaminophen (600 mg/kg, i.p.). A. lappa suppressed the SGOT and SGPT elevations induced by CCl4 or acetaminophen in a dose-dependent manner and alleviated the severity of liver damage based on histopathological observations. In an attempt to elucidate the possible mechanism(s) of this hepatoprotective effect, glutathione (GSH), cytochrome P-450 (P-450) and malondialdehyde (MDA) contents were studied. A. lappa reversed the decrease in GSH and P-450 induced by CCl4 and acetaminophen. It was also found that A. lappa decreased the malondialdehyde (MDA) content in CCl4 or acetaminophen-intoxicated mice. From these results, it was suggested that A. lappa could protect the liver cells from CCl4 or acetaminophen-induced liver damages, perhaps by its antioxidative effect on hepatocytes, hence eliminating the deleterious effects of toxic metabolites from CCl4 or acetaminophen.

  19. Hepatocurative potential of sesquiterpene lactones of Taraxacum officinale on carbon tetrachloride induced liver toxicity in mice.

    Science.gov (United States)

    Mahesh, A; Jeyachandran, R; Cindrella, L; Thangadurai, D; Veerapur, V P; Muralidhara Rao, D

    2010-06-01

    The hepatocurative potential of ethanolic extract (ETO) and sesquiterpene lactones enriched fraction (SL) of Taraxacum officinale roots was evaluated against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in mice. The diagnostic markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin contents were significantly elevated, whereas significant reduction in the level of reduced glutathione (GSH) and enhanced hepatic lipid peroxidation, liver weight and liver protein were observed in CCl 4 induced hepatotoxicity in mice. Post-treatment with ETO and SL significantly protected the hepatotoxicity as evident from the lower levels of hepatic enzyme markers, such as serum transaminase (ALT, AST), ALP and total bilirubin. Further, significant reduction in the liver weight and liver protein in drug-treated hepatotoxic mice and also reduced oxidative stress by increasing reduced glutathione content and decreasing lipid peroxidation level has been noticed. The histopathological evaluation of the liver also revealed that ETO and SL reduced the incidence of liver lesions induced by CCl 4 . The results indicate that sesquiterpene lactones have a protective effect against acute hepatotoxicity induced by the administration of CCl 4 in mice. Furthermore, observed activity of SL may be due to the synergistic action of two sesquiterpene lactones identified from enriched ethyl acetate fraction by HPLC method.

  20. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2016-01-01

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

  2. Hepatoprotective effect of Origanum vulgare in Wistar rats against carbon tetrachloride-induced hepatotoxicity.

    Science.gov (United States)

    Sikander, Mohammad; Malik, Shabnam; Parveen, Kehkashan; Ahmad, Maqsood; Yadav, Deepak; Hafeez, Zubair Bin; Bansal, Manish

    2013-04-01

    The effect of an aqueous extract of Origanum vulgare (OV) leaves extract on CCl4-induced hepatotoxicity was investigated in normal and hepatotoxic rats. To evaluate the hepatoprotective activity of OV, rats were divided into six groups: control group, O. vulgare group, carbon tetrachloride (CCl4; 2 ml/kg body weight) group, and three treatment groups that received CCl4 and OV at doses of 50, 100, 150 mg/kg body weight orally for 15 days. Alanine amino transferase (ALT), alkaline phosphatase (ALP), and aspartate amino transferase (AST) in serum, lipid peroxide (LPO), GST, CAT, SOD, GPx, GR, and GSH in liver tissue were estimated to assess liver function. CCl4 administration led to pathological and biochemical evidence of liver injury as compared to controls. OV administration led to significant protection against CCl4-induced hepatotoxicity in dose-dependent manner, maximum activity was found in CCl4 + OV3 (150 mg/kg body weight) groups and changes in the hepatocytes were confirmed through histopathological analysis of liver tissues. It was also associated with significantly lower serum ALT, ALP, and AST levels, higher GST, CAT, SOD, GPx, GR, and GSH level in liver tissue. The level of LPO also decreases significantly after the administration of OV leaves extract. The biochemical observations were supplemented with histopathological examination of rat liver sections. Thus, the study suggests O. vulgare showed protective activity against CCl4-induced hepatotoxicity in Wistar rats and might be beneficial for the liver toxicity.

  3. The Aqueous Seed Extract Of Carica papaya Linn. Prevents Carbon Tetrachloride Induced Hepatotoxicity In Rats

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    A A Adeneye

    2009-06-01

    Full Text Available Summary: Carica papaya Linn. is known to have a versatile application in African folkloric medicine. In the current study, the dose-dependent (100 – 400 mg/kg/day/oral route and time-course protective effects of the 400 mg/kg/oral route of the aqueous seed extract of unripe and mature Carica papaya fruit (CPE were investigated in carbon tetrachloride (CCl4 hepatotoxic rats for 72 hours. Results showed the extract to cause significant (p<0.05, p<0.001, dose related attenuation in the elevation of serum liver enzyme markers of acute hepatocellular injury (ALT, AST, serum lipids (TG, TC, HDL-c, LDL-c and VLDL-c and serum proteins (TP and ALB. Maximum hepatoprotection was offered at an oral dose of 400 mg/kg/day of the extract. The biochemical results obtained were corroborated by improvements in the CCl4-induced hepatic histological changes. In addition, maximum hepatoprotection was offered at the 400 mg/kg of CPE for up to 3 hours post-CCl4 induction. In conclusion, the results obtained in the current study justify the folkloric application of CPE in the treatment of drug-related hepatic injury. Industrial relevance: Results of the current study provide some scientific information to develop safe and effective products such as food supplements, dietary supplements, etc. that could be useful in the clinical management of patients with drug related hepatic disorders.

  4. Carbon tetrachloride-induced hepatotoxicity in rat is reversed by treatment with riboflavin.

    Science.gov (United States)

    Al-Harbi, Naif O; Imam, Faisal; Nadeem, Ahmed; Al-Harbi, Mohammed M; Iqbal, Muzaffar; Ahmad, Sheikh Fayaz

    2014-08-01

    Liver is a vital organ for the detoxification of toxic substances present in the body and hepatic injury is associated with excessive exposure to toxicants. The present study was designed to evaluate the possible hepatoprotective effects of riboflavin against carbon tetrachloride (CCl4) induced hepatic injury in rats. Rats were divided into six groups. Hepatotoxicity was induced by the administration of a single intraperitoneal dose of CCl4 in experimental rats. Riboflavin was administered at 30 and 100mg/kg by oral gavage to test its protective effect on hepatic injury biochemically and histopathologically in the blood/liver and liver respectively. The administration of CCl4 resulted in marked alteration in serum hepatic enzymes (like AST, ALT and ALP), oxidant parameters (like GSH and MDA) and pro-inflammatory cytokine TNF-α release from blood leukocytes indicative of hepatic injury. Changes in serum hepatic enzymes, oxidant parameters and TNF-α production induced by CCl4 were reversed by riboflavin treatment in a dose dependent manner. Treatment with standard drug, silymarin also reversed CCl4 induced changes in biomarkers of liver function, oxidant parameters and inflammation. The biochemical observations were paralleled by histopathological findings in rat liver both in the case of CCl4 and treatment groups. In conclusion, riboflavin produced a protective effect against CCl4-induced liver damage. Our study suggests that riboflavin may be used as a hepato-protective agent against toxic effects caused by CCl4 and other chemical agents in the liver.

  5. Hepatoprotective effect of Rosa canina fruit extract against carbon tetrachloride induced hepatotoxicity in rat

    Directory of Open Access Journals (Sweden)

    Heibatollah Sadeghi

    2016-03-01

    Full Text Available Objective: The present study was conducted to investigate the hepatoprotective activity of hydro-ethanolic fruit extract of Rosa canina (R. canina against carbon tetrachloride (CCl4-induced hepatotoxicity in rats. Methods: Male Wistar albino rats were randomly divided into six groups of 8 animals of each, including control, toxic (CCl4, R. canina 250, 500, and 750 mg/kg + CCl4 and R. canina 750 mg/kg alone. R. canina (p.o., daily and CCl4 (1 ml/kg twice a week, 50% v/v in olive oil, i.p. were administered to animals for six weeks. Serum analysis was performed to assay the levels of aspartate aminotransferase (AST, alanine amino transaminase (ALT, alkaline phosphatase (ALP, albumin (ALB, total protein (TP and malondialdehyde (MDA. Biochemical observations were also supplemented with histopathological examination (haematoxylin and eosin staining of liver section.Results: Hepatotoxicity was evidenced by considerable increase in serum levels of AST, ALT, ALP, and lipid peroxidation (MDA and decrease in levels of ALB and TP. Injection of CCL4 also induced congestion in central vein, and lymphocyte infiltration. Treatment with hydro-alcoholic fruit extract of R. canina at doses of 500 and 750 mg/kg significantly reduced CCl4-elevated levels of ALT, AST, ALP and MDA (p

  6. Protective effects of Cornus mas fruit extract on carbon tetrachloride induced nephrotoxicity in rats.

    Science.gov (United States)

    Es Haghi, M; Dehghan, G; Banihabib, N; Zare, S; Mikaili, P; Panahi, F

    2014-09-01

    Oxidative damage is implicated in the pathogenesis of kidney injury. Cornus mas is used for in renal aliments traditionally in Iran. The present study was aimed to investigate the antioxidant activity of C. mas fruit extract (CMFE) on carbon tetrachloride (CCl4) treated oxidative stress in Wistar albino rats. Forty two male albino rats were divided into seven groups. Group I served as a sham; Group II served as a normal control; Group III served as a toxic control, with CCl4 (1 ml/kg body weight; 80% in olive oil); Groups IV and V received CMFE at doses of 300 and 700 mg/kg before CCl4 injection; Groups VI and VII received extract at same doses orally at 2, 6, 12, 24 and 48 h after CCl4 intoxication. CCl4 injection produced a significant rise in serum markers of oxidative stress and lipid peroxidation product malondialdehyde along with the reduction of antioxidant enzymes such as superoxide dismuta, catalase and glutathion peroxidase. Serum creatinine, urea and uric acid concentrations were increased whereas level of protein and albumin were reduced. Treatment of rats with different doses of fruit extract (300 and 700 mg/kg) significantly (P induced with CCl4 in lipid peroxidation, antioxidant defenses, biochemical and renal lesions. Based on these results, we conclude that CMFE protects kidney from oxidative stress induced by CCl4.

  7. 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.

  8. Evaluation of hepatoprotective effect of Amalkadi Ghrita against carbon tetrachloride-induced hepatic damage in rats.

    Science.gov (United States)

    Achliya, Girish S; Wadodkar, Sudhir G; Dorle, Avinash K

    2004-02-01

    Amalkadi Ghrita (AG), a polyherbal formulation, was evaluated for its hepatoprotective activity against carbon tetrachloride (CCl4)-induced hepatic damage in rats. The hepatoprotective activity of AG was evaluated by measuring levels of serum marker enzymes like serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), and acid phosphatase (ACP). The serum levels of total proteins and bilirubin were also estimated. The histological studies were also carried out to support the above parameters. Silymarin was used as standard drug. Administration of AG (100 and 300 mg/kg, p.o.) markedly prevented CCl4-induced elevation of levels of serum GPT, GOT, ACP, ALP, and bilirubin. The decreased level of total proteins due to hepatic damage induced by CCl4 was found to be increased in AG-treated group. The results are comparable to that of silymarin. A comparative histopathological study of liver exhibited almost normal architecture, as compared to CCl4-treated group. Hepatoprotective effect of AG is probably due to combined action of all ingredients.

  9. Sida rhombifolia ssp. retusa seed extract inhibits DEN induced murine hepatic preneoplasia and carbon tetrachloride hepatotoxicity.

    Science.gov (United States)

    Poojari, Radhika; Gupta, Sanjay; Maru, Girish; Khade, Bharat; Bhagwat, Sanjay

    2009-01-01

    Sida rhombifolia ssp. retusa is a well established drug in the Ayurvedic system of medicine used for antirheumatism and antiasthmatism. Inhibitory effects of S. rhombifolia ssp. retusa seed extract on DEN induced hepatocellular preneoplastic foci and carbon tetrachloride (CCl4) induced hepatotoxicity was investigated in rats. Rats received DEN, 1ppm/g b.w. in drinking water for 6 weeks or CCl(4), 0.7 ml/kg i.p. once a week for 4 weeks and seed extract 50 mg, 100 mg/kg b.w. orally prior, during and after exposure to DEN/CCl4 for 20 or 5 weeks, respectively. Treatment with seed extract significantly inhibited the increase in DEN/CCl(4) induced activities of pre-cancerous marker enzymes; gamma-glutamyl transpeptidase, glutathione-S-transferase, hepatotoxicity marker enzymes; glutamate pyruvate transaminase, glutamate oxaloacetate transaminase and alkaline phosphatase as well as lipid peroxidase. Depleted glutathione, protein and albumin levels were restored. Also, histopathological and transmission electron microscopic studies showed prevention of cellular degenerative changes. The chemopreventive and hepatoprotective potentials of seed extract are due to free radical scavenging activity and restoration of cellular structural integrity.

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

    Institute of Scientific and Technical Information of China (English)

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

    2005-01-01

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

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

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    S. Radhakrishnan

    2016-08-01

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

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

    Science.gov (United States)

    Alqasoumi, Saleh

    2010-01-01

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

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

    Science.gov (United States)

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

    2010-01-01

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

  14. 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.

  15. 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.

  16. The protective role of pomegranate juice against carbon tetrachloride-induced oxidative stress in rats.

    Science.gov (United States)

    Pirinççioğlu, Mihdiye; Kızıl, Göksel; Kızıl, Murat; Kanay, Zeki; Ketani, Aydın

    2014-11-01

    Most pomegranate (Punica granatum Linn., Punicaceae) fruit parts are known to possess enormous antioxidant activity. The present study was carried out to determine the phenolic and flavonoid contents of Derik pomegranate juice and determine its effect against carbon tetrachloride (CCl4)-induced toxicity in rats. Animals were divided into four groups (n = 6): group I: control, group II: CCl4 (1 ml/kg), group III: CCl4 + pomegranate juice and group IV: CCl4 + ursodeoxycholic acid (UDCA). Treatment duration was 4 weeks, and the dose of CCl4 was administered once a week to groups II, III and IV during the experimental period. CCl4-treated rats caused a significant increase in serum enzyme levels, such as aspartate aminotransferase, alanine aminotransferase and total bilirubin, and decrease in albumin, when compared with control. Administration of CCl4 along with pomegranate juice or UDCA significantly reduces these changes. Analysis of lipid peroxide (LPO) levels by thiobarbutiric acid reaction showed a significant increase in liver, kidney and brain tissues of CCl4-treated rats. However, both pomegranate juice and UDCA prevented the increase in LPO level. Histopathological reports also revealed that there is a regenerative activity in the liver and kidney cells. Derik pomegranate juice showed to be hepatoprotective against CCl4-induced hepatic injury. In conclusion, present study reveals a biological evidence that supports the use of pomegranate juice in the treatment of chemical-induced hepatotoxicity.

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

    Science.gov (United States)

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

    2010-02-28

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

  18. Xanthohumol prevents carbon tetrachloride-induced acute liver injury in rats.

    Science.gov (United States)

    Pinto, Carmen; Duque, Antonio L; Rodríguez-Galdón, Beatriz; Cestero, Juan J; Macías, Pedro

    2012-10-01

    Xanthohumol (XN), a prenyl flavonoid present in beer, prevents the acute hepatic injury induced by carbon tetrachloride (CCl4) in rats. Pre-treatment of rats with XN significantly reduced the increased liver weight observed in CCl4-intoxicated rats, normalised the increased values of plasma lactate dehydrogenase, glutamate oxaloacetate transaminase and glutamate pyruvate transaminase activities and reduced the incidence of histopathological alterations produced by CCl4. The oxidative stress induced by CCl4 administration elicited a significant decrease in the levels of reduced glutathione as well as an increase in thiobarbituric acid reactive substances (TBARS) and H2O2 concentrations. Pre-treatment of rats with XN resulted in a significant (p<0.05) increase in reduced glutathione (GSH) content and a reduction in TBARS and H2O2 concentrations to their normal values. XN pre-treatment also prevented the significant reductions of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione S-transferase activities observed in CCl4-treated rats compared to control animals. Our results suggest that the hepatoprotective effect of XN is based on its antioxidant properties as well as it being an efficient inhibitor of lipid peroxidation and a protector against the degradation of antioxidant enzymes induced by CCl4 intoxication.

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

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    Hong Zhang

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

  20. Radon inhalation protects mice from carbon-tetrachloride-induced hepatic and renal damage.

    Science.gov (United States)

    Kataoka, Takahiro; Nishiyama, Yuichi; Toyota, Teruaki; Yoshimoto, Masaaki; Sakoda, Akihiro; Ishimori, Yuu; Aoyama, Yutaka; Taguchi, Takehito; Yamaoka, Kiyonori

    2011-12-01

    We assessed whether radon inhalation provided protection from carbon tetrachloride (CCl4)-induced hepatic and renal damage in mice. Mice were subjected to intraperitoneal injection of CCl4 after inhaling approximately 18 kBq/m3 radon for 6 h. Radon inhalation significantly increased total glutathione (t-GSH) content and glutathione peroxidase (GPx) activity in the liver and kidney. Injection of CCl4 was associated with significantly higher levels of glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (ALP) activity and creatinine level in serum, and pretreatment with radon significantly decreased the GOT and ALP activity and creatinine level associated with CCl4 injection, suggesting that radon inhalation alleviates CCl4-induced hepatic and renal damage. The t-GSH contents and GPx activity in the liver and kidney of animals pretreated with radon were significantly higher than those of the CCl(4)-only group. These findings suggested that radon inhalation activated antioxidative functions and inhibited CCl4-induced hepatic and renal damage in mice.

  1. Total Flavonoids from Mimosa Pudica Protects Carbon Tetrachloride-Induced Acute Liver Injur y in Mice

    Institute of Scientific and Technical Information of China (English)

    QIU Zhen-qin; CAI Lei; CHEN Da-shuai

    2015-01-01

    Objective:To observe the protective effect of total lfavonoids 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 model group, each dose group of total lfavonouida from Mimosa pudica could reduced 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 lfavonouida from Mimosa pudica could increase the content of Alb in mice (P<0.01). Each dose group of total lfavonouida from Mimosa pudica could enhance the level of T-AOC (P<0.01), and lower the content of liver homogenate MDA, but enhance the activity of SOD in a dose-depended manner (P<0.01).

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. D-Pinitol Protects Against Carbon Tetrachloride-Induced Hepatotoxicity in Rats.

    Science.gov (United States)

    Rengarajan, Thamaraiselvan; Rajendran, Peramaiyan; Nandakumar, Natarajan; Lokeshkumar, Boobathy; Balasubramanian, Maruthaiveeran Periyasamy

    2015-01-01

    The aim of the study was to evaluate the protective activity of D-Pinitol against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The animals were divided into six groups, with each group consisting of six animals. Group I animals served as normal controls and received olive oil vehicle (1.0 ml/kg body weight intraperitoneally). Group II rats served as CCl4 controls, which received 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks. Group III rats were treated with 30% CCl4 suspended in olive oil (3.0 ml/kg body weight intraperitoneally) twice a week for 4 weeks, followed by D-Pinitol (100 mg/kg body weight) given for 28 days intragastrically. Group IV rats received D-Pinitol alone at a concentration of 100 mg/kg body weight for 28 days intragastrically. At the end of the experimental period, serum marker enzymes and lipid peroxidation (LPO) levels were significantly increased in group II animals. On the other hand, D-Pinitol treatment significantly decreased marker enzymes and LPO levels and increased the antioxidant level. CYP expression was also investigated. Therefore, the present study revealed that D-Pinitol acts as a protective agent by decreasing metabolic activation of xenobiotics through its antioxidant nature.

  5. 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.

  6. Contribution of mononuclear bone marrow cells to carbon tetrachloride-induced liver fibrosis in rats

    Institute of Scientific and Technical Information of China (English)

    Bao-Qiang Cao; Ji-Zong Lin; Yue-Si Zhong; Shao-Bin Huang; Nan Lin; Zhao-Feng Tang; Rui Chen; Peng Xiang; Rui-Yun Xu

    2007-01-01

    AIM:To study the inhibitory effect of mononuclear bone marrow cell (BMC) transplantation on carbon tetrachloride (CCIt) -induced liver fibrosis in rats.METHODS:Rat liver fibrosis models were induced by CCN and alcohol administration. After 8 wk,twenty rats were randomly allocated into treatment group (n = 10) and control group (n = 10). BMC were infused into the rats in treatment group via the portal vein,while heparinized saline was infused in control group. CCU was hypodermically injected into the rats twice a week for 4 wk. At the end of wk 12,all rats were humanely sacrificed. Liver samples were taken and stained with HE or Masson trichrome. The general conditions,liver fibrSsis (hydroxyproline and collagen fibre) and liver pathological grades in rats were evaluated.± 128.8μg/g in treatment group,and 596.0 ± 341. 8μg/g in control group.The percentage of collagen fibre was 3.75% ± 0.98% in treatment group and 5.02% ± 0.44% in control group.There was a significant difference berween the two groups (P<0.05).Liver pathological grade decreased from grade Ⅳ to grade Ⅲ partially in treatment group (P<0.05) with no obvious improvement in control group (P<0.05).There was a significant difference between treatment group and control group(P<0.05).CONCLUSION: Transplantation of BMC can improve liver fibrosis due to chronic liver injury in rats.

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

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    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.

  8. Antioxidant and hepatoprotective effects of flower extract of Millingtonia hortensis Linn. on carbon tetrachloride induced hepatotoxicity

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    S Babitha

    2012-01-01

    Full Text Available Objective: Millingtonia hortensis Linn is an abundant resource of flavonoids, which might be beneficial in protecting liver tissue from injury. The hepatoprotective and antioxidant potential of ethanolic extract of M. hortensis on carbon tetrachloride (CCl 4 induced hepatotoxicity and the possible mechanism involved therein were investigated in rats. Materials and Methods: Preliminary phytochemical studies were carried out to determine the total phenol and flavonoid contents. 30 adult Wistar rats were allocated into 5 groups. Control group received vehicle, group-2 received CCl 4 alone (1 ml/kg body weight, intraperitonially, groups 3 - 5 received the ethanolic flower extract in 2 dose levels (200 and 400 mg/kg and Curcumin (100 mg/kg as a standard for 8 days orally, followed by CCl 4 as a single dose on the 8 th day. 48 hours later, blood was withdrawn, serum was subjected to biochemical assessments, and liver homogenate was examined for lipid peroxides, glutathione, superoxide dismutase, catalase and total protein levels. Furthermore, hepatic tissues were subjected to histopatological studies. Results: CCl 4 treatment produced a profound increase in the levels of malondialdehyde, hepatic marker enzymes and bilirubin content compared with the control (P < 0.05. Pre-treatment with the flower extract of M. hortensis significantly enhanced the levels of endogenous antioxidants and reduced the levels of hepatic marker enzymes in relation to the CCl 4 treated group (P < 0.05. Balloning degeneration and fatty changes in hepatocytes was prevented by pre-treatment with the flower extract. Conclusion: The antioxidant nature of the flower extract of M. hortensis could be responsible for averting damage to the liver.

  9. Protective Effect of Berberis integerrima Fruit Extract on Carbon-Tetrachloride Induced Hepatotoxicity in Rats

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    fereshteh rafiee

    2013-09-01

    Full Text Available Background & Objective: Hepatoprotective effect of antioxidants such as flavnoids has been demonstrated. The aim of the present study was to assess the hepatoprotective effect of the methanolic extract of Berberis integerrima fruit (MEBIF on carbon-tetrachloride (CCL4 induced hepatotoxicity in rats. Materials & Methods: Forty male rats were divided into 5 groups as follows: 1 normal, 2 toxicant control (CCL4 was injected intraperitoneally (1 mg/kg bw, 3&4 toxicant rats treated with MEBIF at dose 250 and 500 mg/kg bw, and 5 toxicant rats treated with silymarin. At the end of the study, all the rats were sacrificed and some biochemical parameters of serum such as Alanine Aminotransferase (ALT, aspartate aminotransferase (AST and Alk‌aline Phosphatase (ALP, total proptein, total bilirubin and albumin, and concentrations of malondialdehyde (MDA, superoxide dismutase (SOD, Catalase (CAT and FRAP (Ferric Reducing/Antioxidant Power in liver tissue hemogenate were estimated. The Data was analyzed by one way variance analysis and Tukey’s test using SPSS 21. Results: injection of CCl4 significantly (P≤001/0 increased levels of ALT, AST, ALP, total bilirubin and MDA and decreased levels of total protein, albumin CAT, SOD (P≤ (001/0and FRAP in toxicant rats. In groups toxicant + Berberis (250&500 and toxicant + silymarin restored these changes to normal levels. Histopathological findings are cosistent with biochemical findings. Conclusion: MEBIF have a hepatoprotective effect on CCL4- induced hepatic damage in rats and these effects might be contributed to modulation of detoxification enzymes and antioxidant and free radical scavenger effects.

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

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    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.

  11. 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.

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

    Science.gov (United States)

    Atasever, Ayhan; Yaman, Duygu

    2014-10-01

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

  13. Metallocoenzyme-mediated reductive transformation of carbon tetrachloride in titanium (III) citrate aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, P.C.; Reinhard, M. [Stanford Univ., CA (United States)

    1995-03-01

    Transformation pathways for carbon tetrachloride (CCl{sub 4}) catalyzed by hematin or vitamin B{sub 12} in aqueous titanium(III) citrate solution are proposed. The reaction of CCl{sub 4} with B{sub 12} was zero order in CCl{sub 4} and first order in B{sub 12}, and the rate constant was measured from pH 7.3 to pH 10.3. The proposed rate-limiting step is the reduction of the stable trichloromethylcobalamin (CCl{sub 3}-Cbl) intermediate by titanium(III) citrate at alkaline pH and the sterically induced CCl{sub 3}-Cbl decomposition at neutral pH. The reaction kinetics can be described by a modified Michaelis-Menten model in the saturated regime. With hematin, only the pseudo-first-order rate constant was determined due to the significant deactivation of the coenzyme. The turnover number of hematin (molecules of CCl{sub 4} transformed/molecule of hematin deactivated) was 27 at pH 8.0 and 42 at pH 9.9. Vitamin B{sub 12} was a more stable and more effective catalyst (on a molar basis) than hematin with respect to CCl{sub 4}. Chloroform (CHCl{sub 3}) was the primary product in titanium(III) citrate solution, and the yield was a function of pH, Ti(III) concentration, and organic content regardless of whether a coenzyme was present or which coenzyme was used. Although B{sub 12} and hematin can both enhance the CCl{sub 4} transformation rate, they have little effect on the CHCl{sub 3} yield. Titanium(III) citrate, on the other hand, controls not only the transformation rate but also CHCl{sub 3} formation. 77 refs., 10 figs.

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

    Science.gov (United States)

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

    2016-09-01

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

  15. 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.

  16. Hepatoprotective effects of Bupleurum exalatum extracts against carbon tetrachloride induced liver injury in rats

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    s Roozbehi

    2015-03-01

    Full Text Available Background & aim: Some of natural and synthetic products have antioxidant properties which protect the liver against the destructive factors. This study aimed to investigate the effect of Bupleurum exelatum (B. exalatum extracts on rat liver. Material and method: This experimental study was conducted at Yasouj University of Medical Sciences in 2013 on 50 healthy adult male Wistar rats. Animals were randomly divided into five equal groups: the normal group (receiving, olive oil, control and experiment groups receiving different dose of carbon tetrachloride and olive oil. The experiment group was given daily doses of 75, 150 and 300 mg per Kg of B. exalatum extract by gavage respectively. After two months, the liver enzymes, total protein, albumin and bilirubin in animal’s sera were measured. Data were analyzed by the SPSS software, using ANOVA and tuky-test. Result: The toxicant significantly (P < 0.05 increased the levels of ALT, AST, ALP, TB, DB, and decrease the level of TP and ALB. Oral administration of B. exalatum extracts showed a significant (P < 0.05 decrease in all the elevated serum and significant increase (P < 0.05 in TP and ALB levels at all usage doses. These results indicate the maximum recovery was observed in 300 mg/kg/day. The histopathological changes i.e. fatty changes, necrosis etc were partly or fully prevented in animals treated with the extracts. Conclusion: These findings suggest that the extract of B. exalatum possessed hepatoprotective activity, which could be linked to their phytochemical constituents and antioxidant activity this therefore requires further in-depth studies.

  17. Hepatoprotective effect of commercial herbal extracts on carbon tetrachloride-induced liver damage in Wistar rats

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    Paula Cordero-Pérez

    2013-01-01

    Full Text Available Background : Various hepatoprotective herbal products from plants are available in Mexico, where up to 85% of patients with liver disease use some form of complementary and alternative medicine. However, only few studies have reported on the biological evaluation of these products. Objective : Using a model of carbon tetrachloride (CCl4 -induced hepatotoxicity in rats, we evaluated the effects of commercial herbal extracts used most commonly in the metropolitan area of Monterrey, Mexico. Materials and Methods : The commercial products were identified through surveys in public areas. The effect of these products given with or without CCl4 in rats was evaluated by measuring the serum concentrations of aspartate amino transferase (AST and alanine amino transferase (ALT, and histopathological analysis. Legalon® was used as the standard drug. Results : The most commonly used herbal products were Hepatisan® capsules, Boldo capsules, Hepavida® capsules, Boldo infusion, and milk thistle herbal supplement (80% silymarin. None of the products tested was hepatotoxic according to transaminase and histological analyses. AST and ALT activities were significantly lower in the Hepavida+CCl4 -treated group as compared with the CCl4 -only group. AST and ALT activities in the silymarin, Hepatisan, and Boldo tea groups were similar to those in the CCl4 group. The CCl4 group displayed submassive confluent necrosis and mixed inflammatory infiltration. Both the Hepatisan+CCl4 and Boldo tea+CCl4 groups exhibited ballooning degeneration, inflammatory infiltration, and lytic necrosis. The silymarin+CCl4 group exhibited microvesicular steatosis. The Hepavida+CCl4 - and Legalon+CCL4 -treated groups had lower percentages of necrotic cells as compared with the CCl4 -treated group; this treatment was hepatoprotective against necrosis. Conclusion : Only Hepavida had a hepatoprotective effect.

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

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    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.

  19. A Historical Perspective on Primary and Possible Secondary Sources of Atmospheric Carbon Tetrachloride

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    Singh, Hanwant B.

    2015-01-01

    Atmospheric sources of Carbon Tetrachloride (CTC) have been controversial since its detection in the early 1970. Initial proposals were that it is globally uniformly distributed and its lack of current emissions and inferred lifetime indicated that it was likely of natural origin. Historical analysis of CTC use and emissions showed that atmospheric CTC was long-lived and mainly of man-made origin although small natural sources and sinks (e. g. oceans) could not be ruled out. This deduction was hard because a majority of emissions had occurred in early part of the 20th century when CTC was commonly used as a fumigant, a solvent, and a raw material for the manufacture of many chemicals. In the 1940's adverse health effects of exposure to CTC became evident and its emissions were greatly curtailed and substituted with C2Cl4 which was thought to be much safer. There were smog chamber studies that showed that C2Cl4, a widely used solvent during the late 20th century, could produce CTC with up to a 7% yield. Subsequently it was discovered that this chemistry probably required Cl atoms and since Cl atoms were not abundant in the atmosphere actual yields based on OH oxidation were probably closer to 0.1%. CTC was subsequently banned by the Montreal Protocol to prevent stratospheric ozone depletion and its preferred substitute C2Cl4 was also banned by EPA for reasons of potential carcinogenicity and toxicity. CTC since has been measured in many airborne NASA campaigns in which plumes have been sampled from a variety of regions which may still be emitting CTC. I will briefly discuss this historical perspective of CTC and show some recent data that may shed light on its current sources or lack there off.

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

    Science.gov (United States)

    2012-01-01

    The aim of this study was to investigate the hepatoprotective effect of Matrine salvianolic acid B salt on carbon tetrachloride (CCl4)-induced hepatic fibrosis in rats. Salvianolic acid B and Matrine has long been used to treat liver fibrosis. Matrine salvianolic acid B salt is a new compound containing Salvianolic acid B and Matrine. Hepatic fibrosis induced by CCl4 was studied in animal models using Wistar rats. Organ coefficient, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), hexadecenoic acid (HA), laminin (LN), hydroxyproline (Hyp), and glutathione (GSH), malondialdehyde (MDA), superoxide dismutase (SOD) in liver tissues were measured, respectively. Histopathological changes in the livers were studied by hematoxylin-eosin (H&E) staining and Masson Trichrome (MT) examination. The expression of transforming growth factor-β1 (TGF-β1) and α-smooth muscle actin (α-SMA) was observed by immunohistochemical analysis. A significant reduction in serum levels of AST, ALT, HA, LN and Hyp was observed in the Matrine salvianolic acid B salt treated groups, suggesting that the salt had hepatoprotective effects. The depletion of GSH and SOD, as well as MDA accumulation in liver tissues was suppressed by Matrine salvianolic acid B salt too. The expression of TGF-β1 and α-SMA measured by immunohistology was significantly reduced by Matrine salvianolic acid B salt in a dose-dependent manner. Matrine salvianolic acid B salt treatment attenuated the necro-inflammation and fibrogenesis induced by CCl4 injection, and thus it is promising as a therapeutic anti-fibrotic agent against hepatic fibrosis. PMID:22559721

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

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    Gao Hong-Ying

    2012-05-01

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

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

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    Gang Tan

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

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

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    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.

  5. Simultaneous anaerobic transformation of tetrachloroethene and carbon tetrachloride in a continuous flow column

    Science.gov (United States)

    Azizian, Mohammad F.; Semprini, Lewis

    2016-07-01

    Tetrachloroethene (PCE) and carbon tetrachloride (CT) were simultaneously transformed in a packed column that was bioaugmented with the Evanite culture (EV). The data presented here have been obtained over a period of 1930 days. Initially the column was continuously fed synthetic groundwater with PCE (0.1 mM), sulfate (SO42 -) (0.2 mM) and formate (2.1 mM) or lactate (1.1 mM), but not CT. In these early stages of the study the effluent H2 concentrations ranged from 7 to 19 nM, and PCE was transformed to ethene (ETH) (81 to 85%) and vinyl chloride (VC) (11 to 17%), and SO42 - was completely reduced when using either lactate or formate as electron donors. SO42 - reduction occurred concurrently with cis-DCE and VC dehalogenation. Formate was a more effective substrate for promoting dehalogenation based on electron donor utilization efficiency. Simultaneous PCE and CT tests found CT (0.015 mM) was completely transformed with 20% observed as chloroform (CF) and trace amounts of chloromethane (CM) and dichloromethane (DCM), but no methane (CH4) or carbon disulfide (CS2). PCE transformation to ETH improved with CT addition in response to increases in H2 concentrations to 160 nM that resulted from acetate formation being inhibited by either CT or CF. Lactate fermentation was negatively impacted after CT transformation tests, with propionate accumulating, and H2 concentrations being reduced to below 1 nM. Under these conditions both SO42 - reduction and dehalogenation were negatively impacted, with sulfate reduction not occurring and PCE being transformed to cis-dichloroethene (c-DCE) (52%) and VC (41%). Upon switching to formate, H2 concentrations increased to 40 nM, and complete SO42 - reduction was achieved, while PCE was transformed to ETH (98%) and VC (1%), with no acetate detected. Throughout the study PCE dehalogenation to ethene was positively correlated with the effluent H2 concentrations.

  6. Protective Effect of the Persian Gulf brittle star Ophiocoma Erinaceus extract on carbon tetrachloride (CCl4 induced liver damage in adult male Wistar rats

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    Aida Soheili

    2015-12-01

    Full Text Available Background and Aim:  Brittle star possess  bioactive compounds which confer the wound healing capacity and regenerative potency of damaged  arms and organisms to this creature. The aim of the current study was to assess the   protective  effect  of  the  star extract on liver damages induced by carbon tetrachloride in adult male Wistar rats. Materials and Methods: In this experimental study, 32 adult male rats were randomly divided into 4 equal groups: control, Sham exposed, experimental 1 (treated with %25 extract and experimental 2 (treated with %50 extract of star Ophiocoma Erinaceus. The control group received no treatment. The sham exposed groups received carbon tetrachloride .(50% in olive oil .0.5 ml/kg for 7 days. The experimental groups firstly received carbon tetrachloride, then received %25, %50 brittle star extract as intragastric for 7 days. Finally, the animals were sacrificed, and their bodies and livers were weighed. Then, the livers sections were prepared and were examined by means of light microscope. Finally, the obtained  quantitative data was analyzed using SPSS (V; 20, Mini Tab software, ANOVA, and Tukey. at the significant level of P<0.001. Results: Carbon tetrachloride significantly decreased the rats’ body weight, but it increased their livers weight (P<0.001. Histopathological evaluations showed .extensive liver damage. On the other hand, treatment with brittle star extract .ncreased liver weight, reduced. body weight and significantly altered other induced changes by carbon tetrachloride on liver structure such as hepatocytes number, Kupffer cells, and arteritis, which indicated  the improvement of damaged liver tissue (P<0.001. Conclusion: It was found that brittle star extract can exert protective effects on  liver damages induced by carbon tetrachloride on male Wistar rat.

  7. 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.

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

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    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

  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. 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

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

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    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.

  12. Influence of 50-nm polystyrene particles in inducing cytotoxicity in mice co-injected with carbon tetrachloride, cisplatin, or paraquat.

    Science.gov (United States)

    Shimizu, Y; Isoda, K; Tezuka, E; Yufu, T; Nagai, Y; Ishida, I; Tezuka, M

    2012-08-01

    The toxicity of nanomaterials has yet to be fully investigated. In particular, the interactions between nanomaterials and therapeutic drugs require further study. We investigated whether nano-sized polystyrene particles affect drug-induced toxicity. The particles, which are widely used industrially, had diameters of 50 (NPP50), 200 (NPP200) or 1000 (NPP1000) nm. The toxic chemicals tested were carbon tetrachloride, cisplatin (a popular anti-tumor agent), and a widely used herbicide, paraquat. Mice were treated intraperitoneally with either carbon tetrachloride (0.01 ml/kg), cisplatin (100 micromol/kg) or paraquat (50 mg/kg), with or without intravenous administration of polystyrene particles. All treatments in the absence of the nanoparticles were non-lethal and did not result in severe toxicity. However, when mice were injected with paraquat or cisplatin together with polystyrene particles, synergistic, enhanced toxicity was observed in mice injected with NPP50. These synergic effects were not observed in mice co-injected with NPP200 or NPP1000. These findings suggest that further evaluation of the interactions between polystyrene nano-particles and drugs is a critical prerequisite to the pharmaceutical application of nanotechnology.

  13. Transcriptome analysis of the effects of gomisin a on the recovery of carbon tetrachloride-induced damage in rat liver.

    Science.gov (United States)

    Choi, Young Mi; Choi, In Soo; Lee, Sang Mong; Hwang, Dae Youn; Choi, Young Whan; Park, Young Hoon

    2011-06-01

    Gomisin A possesses a hepatic function-facilitating property in liver-injured rats. Its preventive action on carbon tetrachloride-induced cholestasis is due to maintenance of the function of the bile acids-independent fraction. To investigate alterations in gene expression after gomisin A treatment on injured rat liver, DNA microarray analyses were performed on a Rat 44K 4-Plex Gene Expression platform with duplicated reactions after gomisin A treatment. We identified 255 up-regulated and 230 down-regulated genes due to the effects of gomisin A on recovery of carbon tetrachloride-induced rat liver damage. For functional characterization of these genes, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes biochemical pathways analyses were performed. Many up-regulated or down-regulated genes were related to cell cycle or focal adhesion and cell death genes, respectively. Our microarray experiment indicated that the liver repair mechanism induced by gomisin A was strongly associated with increased gene expressions related to cell cycle and suppression of the gene expression related in cell death.

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

    Science.gov (United States)

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

    2001-09-01

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

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-09-15

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

  17. Hydrodechlorination of Silicon Tetrachloride to Trichlorosilane Over Ordered Mesoporous Carbon Catalysts: Effect of Pretreatment of Oxygen and Hydrochloric Acid.

    Science.gov (United States)

    Kwak, Do-Hwan; Akhtar, M Shaheer; Kim, Ji Man; Yang, O Bong

    2016-02-01

    This paper reports on the catalytic reaction for the conversion of silicon tetrachloride (STC) to trichlorosilane (TCS) over pretreated ordered mesoporous carbon (OMC) catalysts by oxygen (denoted as OMC-O2) and hydrochloric acid (denoted as OMC-HCl) at 300 degrees C under N2 atmosphere. The OMC-O2 shows significantly improved the surface area (1341.2 m2/g) and pore volume (1.65 cm3/g), which results in the highest conversion rate of 7.3% as compared to bare OMC (4.3%) and OMC-HCI (5.7%). It is found that the conversion rate of STC to TCS is proportional to the number of Si-O bond over OMC catalysts, which suggests that Si-O-C bond formation is crucial to the reaction as active sites. The O2 pretreatment seems to promote the generation of oxygenated species for the formation of Si-O-C.

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

    Directory of Open Access Journals (Sweden)

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

    2012-01-01

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

  19. The effects of carbon tetrachloride on rat liver microsomes during the first hour of poisoning in vivo, and the modifying actions of promethazine

    Science.gov (United States)

    Slater, T. F.; Sawyer, B. C.

    1969-01-01

    The effects of an oral administration of carbon tetrachloride on various liver microsomal and supernatant components were studied 1hr. and 2hr. after dosing. The modifications of such early changes resulting from a concomitant administration of promethazine together with the carbon tetrachloride were also investigated. The microsomal components studied were: cytochromes P-450 and b5; inorganic pyrophosphatase; NADH– and NADPH–cytochrome c reductases; NADH– and NADPH–neotetrazolium reductases; a lipid-peroxidation system associated with the oxidation of NADPH and stimulated by ADP and Fe2+. NAD– and NADP– DT-diaphorases were measured in the supernatant solution remaining after isolation of liver microsomes, and the distribution of RNA phosphorus between the microsomes and supernatant solution was also determined. Carbon tetrachloride produced a rapid fall in inorganic pyrophosphatase activity, a rather slower decrease in cytochrome P-450 content of the microsomes and small increases in the activities of NADH–cytochrome c reductase and neotetrazolium reductases. The activities of NADPH–cytochrome c reductase, the NADPH–ADP/Fe2+-linked lipid-peroxidation system, DT-diaphorases and the content of cytochrome b5 in the microsomes were unchanged. There was also a loss of RNA phosphorus from the microsomes into the supernatant solution. The RNA phosphorus redistribution, the decrease in inorganic pyrophosphatase and the increases in neotetrazolium reductase activities were at least partially prevented by a concomitant dosing with promethazine. However, the decrease in cytochrome P-450 was not affected by promethazine treatment. These early changes are discussed in terms of the liver necrosis produced by carbon tetrachloride and which is greatly retarded in its onset by the administration of promethazine. PMID:5767054

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

    Directory of Open Access Journals (Sweden)

    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. Loss of Discoidin Domain Receptor 2 Promotes Hepatic Fibrosis after Chronic Carbon Tetrachloride through Altered Paracrine Interactions between Hepatic Stellate Cells and Liver-Associated Macrophages

    OpenAIRE

    Olaso, Elvira; ARTETA, BEATRIZ; BENEDICTO, AITOR; Crende, Olatz; Friedman, Scott L.

    2011-01-01

    Hepatic stellate cells (HSCs) interact with fibrillar collagen through the discoidin domain receptor 2 (DDR2) in acute hepatic injury, generating increased fibrosis. However, the contribution of DDR2 signaling to chronic liver fibrosis in vivo is unclear, despite its relevance to chronic human liver disease. We administered carbon tetrachloride (CCl4) to DDR2+/+ and DDR2−/− mice twice weekly, and liver tissues and isolated HSCs were analyzed. In contrast to changes seen in acute injury, after...

  2. Protective Effects of Pleurotus tuber-regium on Carbon- Tetrachloride Induced Testicular Injury in Sprague Dawley Rats

    Science.gov (United States)

    Okolo, Kenneth O.; Siminialayi, Iyeopu M.; Orisakwe, Orish E.

    2016-01-01

    The high rate of male infertility and the meager resources to manage same in sub Saharan Africa have necessitated the search for cost effective and available alternatives. Mushrooms have been used traditionally in folk medicine and as nutraceuticals. This study has investigated the effect of the wild mushroom Pleurotus tuber-regium on carbon tetrachloride (CCl4) deleterious effects on the reproductive system of male rats. Thirty six rats were divided into six groups of six animals each. Group I (negative control) received 10 ml/kg olive oil intraperitoneal weekly in addition to feed and water ad libitum. Group II (positive control) received CCl4 10 ml/kg (30% in Olive oil) weekly. Group III, IV, and V received 100 mg, 20 0mg, and 500 mg P. tuber-regium (33.3% in feed) daily in addition to 10 ml/kg CCl4 weekly. Group VI received 500 mg P. tuber-regium (33.3% in feed) daily. After 4 weeks, sperm motility, epididymal count and vitality were determined. Serum malondialdehyde (MDA), testosterone, Luteinizing hormone (LH), Follicle stimulating hormone (FSH), prolactin and oestradiol were estimated using enzyme-linked immunosorbent assay (ELISA) kits. Histopathologic examinations of the testis were carried out. Carbon tetrachloride significantly reduced the sperm motility (54.33 ± 3.79%), epididymal count (28.73 ± 2.86 × 106/ml, vitality (4.96 ± 0.62), LH (0.88 ± 0.14), FSH (2.04 ± 0.33), and Testosterone (2.02 ± 0.24) when compared with control (89.33 ± 9.01), 91.91 ± 1.92 × 106/ml, 13.12 ± 0.19, 2.74 ± 0.32, 3.64 ± 0.62, and 4.16 ± 0.23, respectively, which were reversed by P. tuber-regium administration. Co-administration of P. tuber-regium plus CCl4 significantly reduced MDA level. P. tuber-regium showed dose dependent ameliorative activity against CCl4 deleterious action on the testis and may be beneficial in the management of male infertility. PMID:28018218

  3. 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.

  4. 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.

  5. 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.

  6. Protective effect of Silybum marianum and Taraxacum officinale extracts against oxidative kidney injuries induced by carbon tetrachloride in rats.

    Science.gov (United States)

    Karakuş, Ali; Değer, Yeter; Yıldırım, Serkan

    2017-11-01

    The protective effect of the extracts of the plants Silybum marianum and Taraxacum officinale by carbon tetrachloride (CCl4) was researched. Sixty-six female Wistar albino rats were divided into six groups: Control, Silybum marianum, Taraxacum officinale, CCl4, Silybum marianum+ CCl4, Taraxacum officinale+CCl4. The Silybum marianum and Taraxacum officinale extracts were administered as 100 mg/kg/day by gavage. The CCl4 was administered as 1.5 mL/kg (i.p.). At the end of the trial period, in the serums obtained from the animals, in the CCl4 group it was found that the MDA level increased in the kidney tissue samples as well as in the ALP and GGT enzyme activities. It was also found that the GSH level and the GST enzyme activities decreased (pTaraxacum officinale extracts were applied together, it was found that the serum ALP and GGT enzyme activities decreased and that the MDA level decreased in the kidney tissue, and that the GSH level and GST enzyme activities increased. It was observed that the histopathological changes caused by the CCl4 toxicity were corrected by applying the extracts. Eventually, it was determined that the Silybum marianum was more effective. Silybum marianum and Taraxacum officinale extracts which were used against histopathological changes in the kidney caused by toxication showed a corrective effect, which were supported by biochemical parameters.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Enhanced dechlorination of carbon tetrachloride by Geobacter sulfurreducens in the presence of naturally occurring quinones and ferrihydrite.

    Science.gov (United States)

    Doong, Ruey-an; Lee, Chun-chi; Lien, Chia-min

    2014-02-01

    The effect of naturally occurring quinones including lawsone (LQ), ubiquinone (UQ), juglone (JQ), and 1,4-naphthoquinone (NQ) on the biotransformation of carbon tetrachloride (CT) in the presence of Geobacter sulfurreducens and ferrihydrite was investigated. AQDS was used as the model compound for comparison. The reductive dissolution of ferrihydrite by G. sulfurreducens was enhanced by AQDS, NQ, and LQ. However, addition of UQ and JQ had little enhancement effect on Fe(II) production. The bioreduction efficiency and rate of ferrihydrite was highly dependent on the natural property and concentration of quinone compounds and the addition of low concentrations of LQ and NQ significantly accelerated the biotransformation rate of CT. The pseudo-first-order rate constants for CT dechlorination (kobsCT) in AQDS-, LQ- and NQ-amended batches were 5.4-5.8, 4.6-7.4 and 2.4-5.8 times, respectively, higher than those in the absence of quinone. A good relationship between kobsCT for CT dechlorination and bioreduction ratio of ferrihydrite was observed, indicating the important role of biogenic Fe(II) in dechlorination of CT under iron-reducing conditions. Spectroscopic analysis showed that AQDS and NQ could be reduced to semiquinones and hydroquinones, while only hydroquinones were generated in LQ-amended batches.

  9. Nigella sativa improves the carbon tetrachloride-induced lung damage in rats through repression of erk/akt pathway

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    Abdullah Aslan

    2015-08-01

    Full Text Available The objective of this study was to examine whether Nigella sativa plays a protective role against the damage in the lung by administering carbon tetra-chloride (CCl4 to rats. Male Wistar albino (n=28, 8 weeks old rats were divided into 4 groups: a negative control: Normal water consuming group to which no CCl4 and N. sativa was administered; b Positive control: Normal water consuming group to which no CCl4 was administered but N. sativa was administered; c CCl4 Group: Normal water consuming and group to which CCl4 was administered (1.5 mL/kg, ip; d N. sativa plus CCl4 group: CCl4 and N. sativa administered group (1.5 mL/kg, ip. Caspase-3, caspase -9, erk, akt protein syntheses were examined via Western blotting. Malondialdehyde determination in lung tissue was made using spectrophotometer. As a results, malondialdehyde amount was decreased in the CCl4 plus N. sativa group in comparison to CCl4 group whereas caspase-3, caspase-9 was increased and erk, akt had decreased. These results show that N. sativa protects the lung against oxidative damage.

  10. In vitro and in vivo antioxidant activity of alfalfa (Medicago sativa L.) on carbon tetrachloride intoxicated rats.

    Science.gov (United States)

    Al-Dosari, Mohammed S

    2012-01-01

    The present study was conducted to determine whether lyophilized aqueous extract of alfalfa, or Medicago sativa L. could exert antioxidant activity against carbon tetrachloride-induced oxidative stress and liver injury in rats. The hepatoprotective activity of alfalfa extract was determined by assessing the levels of serum transaminases, ALP, bilirubin and lipid profile. Further, the effect of the test substance on malondialdehyde (MDA), an end product of lipid peroxidation; antioxidant liver enzyme non-protein sulfhydryl (NP-SH); and total protein (TP) were also studied. Serum transaminase, ALP, bilirubin level, lipid profile and liver MDA were significantly elevated and the antioxidant status in liver NP-SH and TP contents were declined in animals treated with CCl (4) alone. Pretreatment with alfalfa and silymarin for three weeks prior to the administration of CCl (4) significantly prevented the increase in the serum levels of hepatic marker, LDL, VLDL levels enzymes and reduced oxidative stress indicated by elevated NP-SH and TP concentration. The histopathological examination of the livers also showed that the alfalfa extract reduced the incidence of liver lesions induced by CCl (4). The in vitro antioxidant assessment of alfalfa extract on DPPH and carotene-linoleic assays demonstrated a moderate antioxidant potential. Results suggest that the alfalfa extract possesses hepatoprotective and antioxidative stress properties possibly through its antioxidant phytochemical constituents and substantiates its use in various liver disorders as a hepatoprotector.

  11. Comparison of vitamin E, L-carnitine and melatonin in ameliorating carbon tetrachloride and diabetes induced hepatic oxidative stress.

    Science.gov (United States)

    Shaker, M E; Houssen, M E; Abo-Hashem, E M; Ibrahim, T M

    2009-09-01

    This study aimed to investigate whether treatments with vitamin E, L-carnitine and melatonin can protect against CCl(4) and diabetes-induced hepatic oxidative stress. Hepatic oxidative stress was performed in rats through 50% v/v carbon tetrachloride (CCl(4)) (1 ml/kg/3 days, i.p.), and through diabetes mellitus induced by streptozotocin (STZ) (40 mg/kg, i.p.). Vitamin E (100 mg/kg/day, i.p), L-carnitine (300 mg/kg/day, i.p.) and melatonin (10 mg/kg/day, i.p.) were injected for a period of 6 weeks. Thereafter, changes in serum glucose level, liver function tests, hepatic malondialdehyde (MDA) content, hepatic reduced glutathione (GSH) content, hepatic superoxide dismutase (SOD) activity, and serum total antioxidant capacity (TAC) level were evaluated. In CCl(4)-induced liver fibrosis, the efficacy order was melatonin > L-carnitine > vitamin E, while in STZ-induced diabetes, the efficacy order was vitamin E > or = melatonin > L-carnitine. In conclusion, these data indicate that low dose of melatonin is more effective than high doses of vitamin E and L-carnitine in reducing hepatic oxidative stress induced by CCl(4) and diabetes. Moreover, the potent effect of vitamin E in ameliorating diabetes can be linked not only to the antioxidant actions, but also to the superior effect in reducing diabetes-induced hyperglycaemia. Meanwhile, potency of L-carnitine was nearly the same in CCl(4) and diabetes-induced liver damage.

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

    Directory of Open Access Journals (Sweden)

    Ebaid Hossam

    2013-02-01

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

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

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    Adrián H. Buep

    2014-12-01

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

  14. 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).

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

    Science.gov (United States)

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

    2016-10-01

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

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

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    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.

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

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    Yi-Chun Lin

    2014-06-01

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

  18. Hepatoprotective effects of sesamol loaded solid lipid nanoparticles in carbon tetrachloride induced sub-chronic hepatotoxicity in rats.

    Science.gov (United States)

    Singh, Neha; Khullar, Neeraj; Kakkar, Vandita; Kaur, Indu Pal

    2016-05-01

    Sesamol is a phenolic component of sesame seed oil, which has been established as an antioxidant and also possesses potential for hepatoprotection. However, its protective role in carbon tetrachloride (CCl4 ) induced sub-chronic hepatotoxicity has not been studied. Limited oral bioavailability (BA) and rapid elimination (as conjugates) in rats is reported for sesamol. Considering its significant antioxidant potential and compromised BA, we packaged sesamol into solid lipid nanoparticles (S-SLNs) to enhance its hepatoprotective bioactivity. S-SLNs prepared by microemulsification method were nearly spherical in shape with an average particle size of 120.30 nm and their oral administration at 8 mg/kg body weight (BW) showed significantly (p induced sub-chronic liver injury in rats. Evaluations were done in terms of histological changes in the liver tissue, liver injury markers (serum alanine aminotransferase, serum aspartate aminotransferase, and serum lactate dehydrogenase); oxidative stress markers (lipid peroxidation, superoxide dismutase, and reduced glutathione) and proinflammatory response marker (tumor necrosis factor-alpha).

  19. Antioxidant and Protective Effect of Ethyl Acetate Extract of Podophyllum hexandrum Rhizome on Carbon Tetrachloride Induced Rat Liver Injury

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    Showkat Ahmad Ganie

    2011-01-01

    Full Text Available The antioxidant and hepatoprotective activities of ethyl acetate extract was carefully investigated by the methods of DPPH radical scavenging activity, Hydroxyl radical scavenging activity, superoxide radical scavenging activity, hydrogen peroxide radical scavenging activity, and its reducing power ability. All these in vitro antioxidant activities were concentration dependent, which were compared with standard antioxidants such as BHT, α-tocopherol. The hepatoprotective potential of Podophyllum hexandrum extract was also evaluated in male Wistar rats against carbon tetrachloride- (CCl4- induced liver damage. Pretreated rats were given ethyl acetate extract at 20, 30, and 50 mg/kg dose prior to CCl4 administration (1 mL/kg, 1:1 in olive oil. Rats pretreated with P. hexandrum extract remarkably prevented the elevation of serum AST, ALT, LDH, and liver lipid peroxides in CCl4-treated rats. Hepatic glutathione levels were significantly increased by the treatment with the extract in all the experimental groups. The extract at the tested doses also restored the levels of liver homogenate enzymes (glutathione peroxidase, glutathione reductase, superoxide dismutase, and glutathione-S-transferase significantly. This study suggests that ethyl acetate extract of P. hexandrum has a liver-protective effect against CCl4-induced hepatotoxicity and possess in vitro antioxidant activities.

  20. Protective effects of Chaenomeles thibetica extract against carbon tetrachloride-induced damage via the MAPK/Nrf2 pathway.

    Science.gov (United States)

    Ma, Bingxin; Wang, Jing; Tong, Jing; Zhou, Gao; Chen, Yuxin; He, Jingsheng; Wang, Youwei

    2016-03-01

    Chaenomeles thibetica, a type of fruit of the genus Chaenomeles, is commonly cultivated and used as Mugua in China and as liquor, candy, and functional food in Tibet. Total phenol, flavonoid, and proanthocyanidin contents were measured in C. thibetica extract (CTE). CTE had a positive effect on free radical scavenging and anti-lipid oxidation in vitro. The protective effects of CTE against carbon tetrachloride (CCl4)-induced oxidative damage in vivo were also measured. The results of antioxidative enzymes indicated that CTE can increase the activities of the catalase, superoxide dismutase, and glutathione contents and reduce the level of malondialdehyde in rats. The levels of alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and total bilirubin were significantly reversed by CTE compared with the elevated levels in the CCl4 group. Besides, CTE could reverse the cell viability of HepG2 inoculated with CCl4via phosphorylation of mitogen-activated protein kinases (MAPKs), activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and increasing the expression of phase II detoxification enzymes. These effects may expand the applications of C. thibetica and offer alternative food with antioxidant and hepatoprotective functions in the food industry.

  1. Protective effect of aqueous extracts from Rhizopus oryzae on liver injury induced by carbon tetrachloride in rats.

    Science.gov (United States)

    Suzuki, Takehito; Fukuoka, Hideo; Ushikoshi, Setsuo; Sato, Reiichiro; Morita, Hidetoshi; Takizawa, Tatsuya

    2015-05-01

    Hepatoprotective effects of Rhizopus oryzae/ U-1 aqueous extract (RU) were demonstrated in carbon tetrachloride (CCl4 )-induced liver-injured rats. In order to investigate the RU effects, the rats were administered RU at a dose of 10 or 100 mg/kg of body weight for 10 days before induction of the liver injury by oral administration of CCl4 (125 mg/kg body weight). (i) Pretreatment with RU caused a significant decrease in serum lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities that were increased by the administration of CCl4 . (ii) RU pretreatment (100 mg/kg) increased 5-bromo-2'-deoxyuridine incorporation at 48 h after CCl4 treatment in hepatocytes. (iii) Histological hematoxylin and eosin staining of the liver showed that RU pretreatment reduced the damage induced by CCl4 administration. (iv) Reverse transcriptase PCR analysis showed RU retreatment caused a transient but significant increase in hepatocyte growth factor (HGF) and a sustained and significant increase in insulin-like growth factor-I (IGF-I) gene expression in hepatocytes injured by CCl4 treatment. From these results, we conclude that oral pre-administration of RU was effective to suppress liver injury induced by the subsequent oral CCl4 administration, and RU-induced increase in IGF-I and HGF gene expression may be, even in part, involved in biological actions of RU in rats.

  2. Reconnaissance survey for lightweight and carbon tetrachloride extractable hydrocarbons in the central and eastern basins of Lake Erie: September 1978

    Energy Technology Data Exchange (ETDEWEB)

    Zapotosky, J.E.; White, W.S.

    1980-10-01

    A reconnaissance survey of the central and eastern basins of Lake Erie (22,240 km/sup 2/) was conducted from September 17 to 27, 1978. The survey provided baseline information on natural gas and oil losses from geologic formations, prior to any potential development of natural gas resources beneath the United States portion of the Lake. Lightweight hydrocarbons indicative of natural gas (methane, ethane, propane, isobutane, and n-butane) are introduced into the waters of Lake Erie by escape from geologic formations and by biological/photochemical processes. The geochemical exploration technique of hydrocarbon sniffing provided enough data to reveal significant distribution patterns, approximate concentrations, and potential sources. Twelve sites with elevated lightweight hydrocarbon concentrations had a composition similar to natural gas. In one area of natural gas input, data analysis suggested a potential negative effect of natural gas on phytoplanktonic metabolism (i.e., ethylene concentration). Samples taken for liquid hydrocarbon analysis (carbon tetrachloride extractable hydrocarbons) correlated best with biologically derived lightweight hydrocarbons.

  3. Protective effects of neohesperidin dihydrochalcone against carbon tetrachloride-induced oxidative damage in vivo and in vitro.

    Science.gov (United States)

    Hu, Lihua; Li, Lingrui; Xu, Demei; Xia, Xiaomin; Pi, Ruxian; Xu, Duo; Wang, Wenchao; Du, Hong; Song, Erqun; Song, Yang

    2014-04-25

    The purpose of this study was to investigate the possible hepatoprotective effects of neohesperidin dihydrochalcone (NHDC) on carbon tetrachloride (CCl4)-induced acute oxidative injury in vivo and in vitro. In a mouse model, intraperitoneal injection of CCl4 resulted in a significant increase in serum aspartate transaminase (AST) and alanine transaminase (ALT) activities. Histopathological examination revealed severe hepatocyte necrosis and destruction of architecture in liver lesions, and immunohistochemical staining illustrated a remarkable enhancement of COX-2 and iNOS expression. The levels of hepatic antioxidant, such as, catalase (CAT), total superoxide dismutase (T-SOD), glutathione peroxidase (GP-X) and glutathione (GSH) were decreased, compared to the control group. However, pretreatment of NHDC for six consecutive days significantly ameliorated these changes. Moreover, Western blotting assay indicated pretreatment with NHDC also down-regulated CCl4-induced protein expressions of NF-κB, IL-6, caspase 3 and caspase 8. In HepG2 cell model, CCl4-treatment caused significant decrease in cell viability, antioxidant activities and GSH level, increase in intracellular reactive oxygen species (ROS) and thiobarbituric acid reactive substances (TBARS) level. Interestingly, pretreatment of NHDC effectively relieved CCl4-induced oxidative damage in a dose-dependent manner. In conclusion, NHDC appeared to possess promising anti-oxidative and anti-inflammatory capacities, it is possible to be used as a hepatoprotective agent.

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

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    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

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

    Science.gov (United States)

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

    2002-01-01

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

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

    Science.gov (United States)

    Harris, Todd R.; Bettaieb, Ahmed; Kodani, Sean; Dong, Hua; Myers, Richard; Chiamvimonvat, Nipavan; Haj, Fawaz G.; Hammock, Bruce D.

    2015-01-01

    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. PMID:25827057

  7. Effect in the rat of the interaction of dichloromaleic acid and carbon tetrachloride on renal and hepatic function

    Energy Technology Data Exchange (ETDEWEB)

    Christenson, W.R.; Davis, M.E.; Berndt, W.O. (Univ. of Nebraska Medical Center, Omaha (USA))

    1989-10-01

    Water purification generates a variety of chlorinated contaminants, one of which is dichloromaleic acid (DCMA). Exposure to this compound is likely to occur in combination with other drinking water pollutants, some of which are hepatotoxic. This study was designed to examine the interactive effects of carbon tetrachloride (CCl4), a known hepatotoxin, with DCMA on liver and kidney function in the Sprague-Dawley rat. Administration of a single dose of DCMA (200-400 mg/kg, ip) caused modest dose-dependent increases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and plasma urea nitrogen, as well as a marked depletion of nonprotein sulfhydryls (NPSH) in the liver, but not the kidney, by 24 hr. Pretreatment with inducers (phenobarbital or 3-methylcholanthrene) or an inhibitor (SKF 525A) of cytochrome P-450 activity failed to alter the response observed with DCMA alone. Alterations in 24-hr urine volume, osmolality, and water consumption also were observed. DCMA-mediated changes in plasma urea nitrogen and NPSH were reduced in magnitude with coadministration of CCl4 (1 ml/kg, ip), while anticipated CCl4-induced increases in ALT and AST were reduced with coexposure to DCMA. Renal slice experiments indicated that DCMA-treated rats were less able to accumulate the organic anion p-aminohippurate (PAH), whereas DCMA had no effect on accumulation of the organic cation tetraethylammonium (TEA). The combination of CCl4 and DCMA produced only additive effects on organic ion accumulation. These results suggest hepatic interaction possibly related to the metabolism of CCl4 and DCMA, resulting in renal and hepatic toxicity diminished from that observed with exposure to either agent alone.

  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. 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

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

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    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.

  11. 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

  12. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

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

    Science.gov (United States)

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

    2010-06-01

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

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

    OpenAIRE

    Ramakrishna S; Geetha K.M,; Bhaskar gopal P.V.V.S,; Ranjit kumar P; Charan Madav. P,; Umachandar. L

    2011-01-01

    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...

  16. 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.

  17. Long-term treatment with shengmai san-derived herbal supplement (Wei Kang Su) enhances antioxidant response in various tissues of rats with protection against carbon tetrachloride hepatotoxicity.

    Science.gov (United States)

    Leong, Pou Kuan; Chen, Na; Chiu, Po Yee; Leung, Hoi Yan; Ma, Chung Wah; Tang, Qing Tao; Ko, Kam Ming

    2010-04-01

    Wei Kang Su (WKS) is a commercial herbal product based on a Chinese herbal formula, Shengmai San. Here, we investigated the effects of long-term treatment with WKS on mitochondrial antioxidant status and functional ability, as well as heat shock protein (Hsp) 25/70 production, in various tissues of rats. WKS treatment enhanced mitochondrial antioxidant status and ATP generation capacity, as well as Hsp 25/70 production in various rat tissues. WKS treatment suppressed plasma reactive oxygen metabolite levels and protected against carbon tetrachloride hepatotoxicity in rats. Long-term WKS treatment may prevent diseases by enhancing the resistance of mitochondria to oxidative stress.

  18. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-09-29

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

  20. 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.

  1. 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.

  2. Effect of Paeonia lactiflora formula granule against the damage of LO2 cells induced by carbon tetrachloride

    Directory of Open Access Journals (Sweden)

    Yan-qing REN

    2016-06-01

    Full Text Available Objective  To investigate the effect of Paeonia lactiflora formula granule (PLFG against the damage of LO2 cells induced by carbon tetrachloride (CCl4 and explore its mechanism. Methods  LO2 cells were divided into control group, CCl4 model group, PLFG (1, 5, 10mg/L groups and Vit E (50mmol/L group. LO2 cells of PLFG groups and Vit E group were pretreated by drugs for 24 hours, then except control group, other groups were treated by 10mmol/L CCl4 for 6 hours, which induced hepatic cell damage, the alanine aminotransferase (ALT and aspartate transaminase (AST content of the cell culture supernatant were measured, the survival rates of LO2 cells were analyzed by MTT method. LO2 cells were divided into control group, CCl4 model group, PLFG (10mg/L group and Vit E (50mmol/L group, cell loss, changes in nuclear size and morphology, DNA content, mitochondrial membrane potential (MMP, cell permeability changes, and cytochrome C release were measured simultaneously by high content analysis (HCA. Results  Compared with CCl4 model group, PLFG and Vit E pretreatment could obviously decrease the level of ALT and AST (P<0.05 or P<0.01, especially in the 10mg/L PLFG group and Vit E group. PLFG (1, 5, 10mg/L and Vit E could also significantly weaken the decrease of LO2 cell viability, which were induced by CCl4 treatment, the results showed in dose-dependent to some extents (P<0.05 or P<0.01. Meanwhile, treatment with 10mg/L PLFG and Vit E could significantly increase the level of MMP (P<0.01, prevent cytochrome C release (P<0.01, decrease the membrane permeability (P<0.01, increase nuclear size (P<0.01, decrease total nuclear intensity (P<0.01 and increase the cell count (P<0.05. Conclusion  PLFG may act an obvious protective effect against the liver injury induced by CCl 4, and it might be due to protecting the integrity of mitochondria membrane, decreasing cell membrane permeability and inhibiting the apoptosis of LO2 cells. DOI: 10.11855/j

  3. 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 tetrachloride – induced 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

  4. Application of Needle Trap Device Packed with Polydimethylsiloxane for Determination of Carbon Tetrachloride and Trichloroethylene in Air

    Directory of Open Access Journals (Sweden)

    M. Heidari

    2014-04-01

    Full Text Available Introduction & Objective: The use of modern microextraction techniques for determination and evaluation of pollutants is progressively increasing nowadays. Needle trap microextraction (NTME technique has privileges compared to the other techniques for sampling occupa-tional and environmental pollutants from air. In this study the application of NTD technique packed with polydimethylsiloxane as sorbent for determination of two organohalogen com-pounds (carbon tetrachloride and trichloroethylene was investigated. Material & Methods: In this experimental study NTDs were prepared with the same length of proposed sorbent and used after calibration of sampling pump. The parameters related to per-formance of NTD and proposed sorbent including temperature and relative humidity, sam-pling storage time and breakthrough volume were investigated. In analytical performances, the capability of NTD on time and temperature of desorption also carryover of analytes were assessed. Finally, the results for NTD microextraction e were compared to the NIOSH 1003 method. Results: Results have shown that, temperature and relative humidity had effects on the per-formance of NTD and it's sorbent, and NTD contained PDMS showed better performance in the lower temperature and relative humidity at the range of assessment. The performance of NTD and it's sorbent for storage of sampled analytes was more than 95% of analytes mass after 4 days of sampling. The proposed technique also showed a good performance for de-sorption parameters and desorption temperature and time was 290?C and 4 minutes, respec-tively. After desorption, the carryover was also investigated and measured as 4 min. Relative standard division (RSD for repeatability of method for NTD from different concentration levels of 1-250 µgL-1were 4.1-7.5%. Conclusions: The NTD technique as an active sampling method with high enrichment factor showed a good performance for sampling and analysis of volatile organohalogen

  5. 四氯化碳法兔肝硬化模型的建立%Establishment of Liver Cirrhosis in Rabbit by subcutaneous injection of carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    郭丽丽; 张铁成; 赵明; 杨雁萍; 张肇慧; 王阿樱; 付旷

    2011-01-01

    目的 探讨通过皮下注射四氯化碳(carbon tetrachloride,CCl4)-橄榄油溶液制备兔肝硬化模型的可行性.方法 体重在2.0-2.5 kg的新西兰大白兔42只,其中实验组36只,分成三组(Ⅰ、Ⅱ、Ⅲ),每组12只,前两周均每周两次皮下注射50%的CCl4-橄榄油溶液0.3 ml/kg,第三周起Ⅰ组每周两次皮下注射50%的CCl4-橄榄油溶液1.5 ml/kg; Ⅱ组每周两次皮下注射50%的CCl4-橄榄油溶液0.9 ml/kg;Ⅲ组每周两次皮下注射50%的CCl4-橄榄油溶液0.4 ml/kg,对照组6只,分成三组,每组2只,分别与实验组相对应注射等量的橄榄油,实验组与对照组均于第12周末处死并取肝组织做病理.结果 三个实验组均造成肝硬化模型,实验过程中兔子死亡率分别为67%、50%、8.3%.结论 皮下注射四氯化碳-橄榄油溶液制备兔肝硬化模型可行,且Ⅲ组造模成功率高,适用于临床研究.%Objective To evaluate the feasibility of rabbit model of liver cirrhosis established by subcutaneous injection of carbon tetrachloride-olive oil solution .Methods 42 body weight during 2.0-2.5 kg New Zealand white rabbits ,36 in experimental group were divided into three groups ( Ⅰ , Ⅱ ,Ⅲ ), 12 in each group, the first two weeks was injected subcutaneously by 0.3 ml/kg 50% carbon tetrachloride-olive oil solution twice-weekly, from the third week Ⅰ , Ⅱ, Ⅲ was injected subcutaneously by 1.5 ml/kg ,0.9 ml/kg ,0.4 ml/kg respectively 50% carbon tetrachloride-olive oil solution twice-weekly ;6 in control group were divided into three groups, 2 in each group corresponding to the experimental group ,was injected with te same amount of olive oil, all rabbits were sacrificed at 12 weeks and obtained liver tissues for pathology .Results Three experimental groups turned into liver cirrhosis models ,rabbit mortality rate during the experiment was 67% ,50% ,8.3% respectively .Conclusion The establishment of liver cirrhosis in rabbit by subcutaneous injection of

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

    Science.gov (United States)

    Semprini, L.; Azizian, M.

    2012-12-01

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

  7. 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.

  8. Headspace gas chromatography determination trichloromethane and carbon tetrachloride in water%顶空气相色谱法测定水中三氯甲烷和四氯化碳

    Institute of Scientific and Technical Information of China (English)

    张丹; 张雪茹; 孙艳梅

    2012-01-01

    Objective To establish a method for determine trichloromethane and carbon tetrachloride in water by headspace capillary column gas chromatography. Method Determination trichloromethane and carbon tetrachloride in water by headspace capillary column gas chromatography. Results The linear ranges of trichloromethane in 1. 0 to 8. 0μg/L and carbon tetrachloride in 0. 05 to 0.40μg/L showed good linear relation. The r value were 0. 9 991 and 0. 9 997, respectively, the recovery rates were during 97. 5% to 103. 3%. Conclusions This method was convenient and fast, it could used for determination the trichloromethane and carbon tetrachloride in water.%目的 建立测定水中三氯甲烷和四氯化碳含量的顶空毛细管柱气相色谱法.方法 采用顶空自动进样技术,用毛细管柱气相色谱法测定水中三氯甲烷和四氯化碳.结果 三氯甲烷在1.0~8.0μg/L、四氯化碳在0.05~0.40μg/L浓度范围内呈良好线性关系,其r值分别为0.9991和0.9997.水样回收率为92.6%-108.7%.结论 该方法简便、快速,可用于水中三氯甲烷、四氯化碳的测定.

  9. Hepatoprotective and antioxidant effects of Glycyrrhiza glabra extract against carbon tetrachloride (CCl(4))-induced hepatocyte damage in common carp (Cyprinus carpio).

    Science.gov (United States)

    Yin, Guojun; Cao, Liping; Xu, Pao; Jeney, Galina; Nakao, Miki; Lu, Chengping

    2011-03-01

    The present study is aiming at evaluating the hepatoprotective and antioxidant effects of Glycyrrhiza glabra extract (2.5, 5 and 10 μg/ml) on the carbon tetrachloride (CCl(4))-induced carp hepatocyte damage in vitro. Glycyrrhiza glabra extract was added to the carp primary hepatocytes before (pre-treatment), after (post-treatment) and both before and after (pre- and post-treatment) the incubation of the hepatocytes with CCl(4). CCl(4) at 8 mM in the culture medium produced significantly elevated levels of lactate dehydrogenase (LDH), glutamate oxalate transaminase (GOT), glutamate pyruvate transaminase (GPT) and malondialdehyde (MDA) and significantly reduced levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px). Pre-treatment (5 μg/ml) and pre- and post-treatment (5 and 10 μg/ml) of the hepatocytes with Glycyrrhiza glabra extract significantly reduced the elevated levels of LDH, GOT, GPT and MDA and increased the reduced levels of SOD and GSH-Px by CCl(4); post-treatment of the hepatocytes with Glycyrrhiza glabra extract at 5 μg/ml reduced the GPT and GOT levels and increased the GSH-Px level, but had no effect on the other parameters at all the studied concentrations. The results support the use of Glycyrrhiza glabra extract as a hepatoprotective and antioxidant agent in fish.

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

    Institute of Scientific and Technical Information of China (English)

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

    2008-01-01

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

  11. Umbelliferone and daphnetin ameliorate carbon tetrachloride-induced hepatotoxicity in rats via nuclear factor erythroid 2-related factor 2-mediated heme oxygenase-1 expression.

    Science.gov (United States)

    Mohamed, Mohamed R; Emam, Manal A; Hassan, Nahla S; Mogadem, Abeer I

    2014-09-01

    Among various phytochemicals, coumarins comprise a very large class of plant phenolic compounds that have good nutritive value, in addition to their antioxidant effects. The purpose of the present study was to investigate the protective effects of two coumarin derivatives, umbelliferone and daphnetin, against carbon tetrachloride (CCl4)-induced hepatotoxicity in rats and elucidate the underlying mechanism. Treatment of rats with either umbelliferone or daphnetin significantly improved the CCl4-induced biochemical alterations. In addition, both compounds alleviated the induced-lipid peroxidation and boosted the antioxidant defense system. Moreover, the investigated compounds attenuated CCl4-induced histopathological alterations of the liver. Finally, umbelliferone and daphnetin induced the nuclear translocation of the nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), thereby inducing the expression and activity of the cytoprotective heme oxygenase-1 (HO-1). These results suggest that umbelliferone and daphnetin ameliorate oxidative stress-related hepatotoxicity via their ability to augment cellular antioxidant defenses by activating Nrf2-mediated HO-1 expression.

  12. Wu-Chia-Pi Solution Attenuates Carbon Tetrachloride-Induced Hepatic Injury through the Antioxidative Abilities of Its Components Acteoside and Quercetin

    Directory of Open Access Journals (Sweden)

    Ching-Chiung Wang

    2012-12-01

    Full Text Available Wu-Chia-Pi medicated wine, composed nine Chinese medicines soaked in 35% alcohol, is widely used in Asia for its health-promoting functions. However, long-term consumption of alcohol could result in liver dysfunction. In this study, Wu-Chia-Pi solution (WCPS and extract (WCPE were prepared by modification of the principals given by the Committee on Chinese Medicine and Pharmacy in Taiwan. The aim of this study was to explore the protective effect of WCPS against carbon tetrachloride (CCl4-induced liver injury and to clarify its active component(s. Antioxidative effects of the test samples were evaluated via MDA inhibition, catalase activity and DPPH-scavenging assays. HPLC was used to analysis the active components. Results showed that WCPS (1 and 5 mL/kg significantly prevented CCl4-induced liver injury without chronic liver toxicity. Referring to the antioxidative activities, WCPE displayed significant MDA inhibitory and DPPH-scavenging activities with IC50 values of 0.91 ± 0.03 and 0.60 ± 0.04 mg/mL, respectively. Catalase activity was also enhanced by treatment of WCPE, acteoside and quercetin. Therefore, we suggest that acteoside and quercetin are the major contributors to the antioxidative and hepatoprotective activities of WCPS, and a possible mechanism could be mediated through reduction of oxidative stress.

  13. A Crucial Role of Bone Morphogenetic Protein Signaling in the Wound Healing Response in Acute Liver Injury Induced by Carbon Tetrachloride

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    Nao Oumi

    2012-01-01

    Full Text Available Background. Acute liver injury induced by administration of carbon tetrachloride (CCl4 has used a model of wound repair in the rat liver. Previously, we reported transient expression of bone morphogenetic protein (Bmp 2 or Bmp4 at 6–24 h after CCl4 treatment, suggesting a role of BMP signaling in the wound healing response in the injured liver. In the present study, we investigated the biological meaning of the transient Bmp expression in liver injury. Methods. Using conditional knockout mice carrying a floxed exon in the BMP receptor 1A gene, we determined the hepatic gene expressions and proliferative activity following CCl4-treated liver. Results. We observed retardation of the healing response in the knockout mice treated with CCl4, including aggravated histological feature and reduced expressions of the albumin and Tdo2 genes, and a particular decrease in the proliferative activity shown by Ki-67 immunohistochemistry. Conclusion. Our findings suggest a crucial role of BMP signaling in the amelioration of acute liver injury.

  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)

    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.

  15. 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.)

  16. Schisandra Lignan Extract Protects against Carbon Tetrachloride-Induced Liver Injury in Mice by Inhibiting Oxidative Stress and Regulating the NF-κB and JNK Signaling Pathways

    Science.gov (United States)

    Chen, Qingshan; Zhan, Qi; Li, Ying; Sun, Sen; Zhao, Liang

    2017-01-01

    Schisandra chinensis (S. chinensis) is a traditional Chinese herbal medicine widely used for the treatment of liver disease, whose main active components are lignans. However, the action mechanisms of the lignans in S. chinensis remain unclear. This study aimed to investigate the protective effect and related molecular mechanism of Schisandra lignan extract (SLE) against carbon tetrachloride- (CCl4-) induced acute liver injury in mice. Different doses of SLE at 50, 100, and 200 mg/kg were administered daily by gavage for 5 days before CCl4 treatment. The results showed that SLE significantly decreased the activities of serum ALT/AST and reduced liver pathologic changes induced by CCl4. Pretreatment with SLE not only decreased the content of MDA but increased SOD, GSH, and GSH-Px activities in the liver, suggesting that SLE attenuated CCl4-induced oxidative stress. The expression levels of inflammatory cytokines TNF-a, IL-1β, and IL-6 were decreased after oral administration of SLE, probably because lignans inhibited the NF-κB activity. Additionally, SLE also inhibited hepatocyte apoptosis by suppressing JNK activation and regulating Bcl-2/Bax signaling pathways. In conclusion, these results suggested that SLE prevented CCl4-induced liver injury through a combination of antioxidative stress, anti-inflammation, and antihepatocyte apoptosis and alleviated inflammation and apoptosis by regulating the NF-κB, JNK, and Bcl-2/Bax signaling pathways.

  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.

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

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2010-07-01

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

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

    Directory of Open Access Journals (Sweden)

    C. H. Jackman

    2010-04-01

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

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

    Institute of Scientific and Technical Information of China (English)

    Ottu OJ; Atawodi SE; Onyike E

    2013-01-01

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

  1. Assessment of changes in energy metabolism parameters provoked by carbon tetrachloride in Wistar rats and the protective effect of white grape juice

    Directory of Open Access Journals (Sweden)

    Tatiane Gabardo

    2015-01-01

    Full Text Available The objective of this study was to evaluate the effect of organic and conventional grape juices consumption on the behavior of rats and their neuroprotective effect on the activity of brain energy metabolism enzymes in different brain areas of adult rats on the experimental model of hepatic encephalopathy. Male Wistar rats (90-days-old were treated once a day with conventional or organic white grape juice by gavage for 14 days (7 μL/g. On the 15th day the rats received carbon tetrachloride (CCl4 in a single dose of 3.0 mL/kg. Cerebral cortex, hippocampus and cerebellum were dissected to measure the activity of creatine kinase (CK and pyruvate kinase (PK. No changes in feeding behavior were observed after the treatment with the grapes juices. However, there was an increase in grooming behavior in the open field test provoked by both juices. CCl4 inhibited CK activity in cerebral cortex and hippocampus of the rats and CCl4 also reduced PK activity in all brain structures studied. Furthermore, both white grape juices prevented the decrease in the activity of CK and PK. Therefore, we can suggest that organic and conventional white grape juices could restore the activity of enzymes with a central role in brain energy metabolism.

  2. The molecular mechanisms of the hepatoprotective effect of gomisin A against oxidative stress and inflammatory response in rats with carbon tetrachloride-induced acute liver injury.

    Science.gov (United States)

    Teraoka, Ryutaro; Shimada, Tsutomu; Aburada, Masaki

    2012-01-01

    Oxidative damage and inflammation are implicated in the pathogenesis of liver injury and fibrosis. In the present study, we investigated the molecular mechanism by which gomisin A conferred a hepatoprotective effect, focusing on its antioxidant and anti-inflammatory effects using rats with carbon tetrachloride (CCl(4))-induced acute liver injury. Pretreatment with gomisin A prior to the administration of CCl(4) markedly prevented an increase in alanine aminotransferase, aspartate aminotransferase, and histological hepatic lesions. Gomisin A was also associated with a decrease in hepatic lipid peroxidation, and increased superoxide dismutase activity, suggesting that gomisin A has an antioxidant effect. In addition gomisin A treatment ameliorated mRNA levels of CCl(4)-induced inflammatory mediators, including tumor necrosis factor-α, interleukin-1β and inducible nitric oxide (NO) synthase, and the protein levels of transcriptional upregulator nuclear factor kappa B (NF-κB) and phospho-inhibitor of NF-κB (IκB). Furthermore, α-smooth muscle actin (α-SMA), a myofibroblast marker, was also inhibited by gomisin A treatment. These results suggest that gomisin A inhibits the oxidative stress and activation of NF-κB, leading to down-regulation of pro-inflammatory mediators and amelioration of fibrogenesis.

  3. Effectiveness of cinnamon (Cinnamomum zeylanicum) bark oil in the prevention of carbon tetrachloride-induced damages on the male reproductive system.

    Science.gov (United States)

    Yüce, A; Türk, G; Çeribaşı, S; Güvenç, M; Çiftçi, M; Sönmez, M; Özer Kaya, Ş; Çay, M; Aksakal, M

    2014-04-01

    In this study, it was aimed to investigate the likelihood of detrimental effects of carbon tetrachloride (CCl4 ) on male reproductive system through oxidative stress mechanism and also protective effects of cinnamon bark oil (CBO). For this purpose, 28 healthy male Wistar rats were divided into four groups, seven rats in each. Group 1 received only olive oil daily; group 2 was treated with 100 mg kg(-1) CBO daily; group 3 was treated with only 0.25 ml kg(-1) CCl4 weekly; and group 4 received weekly CCl4 + daily CBO. All administrations were made by intragastric catheter and maintained for 10 weeks. Body and reproductive organ weights, sperm characteristics, testicular oxidative stress markers and testicular apoptosis were examined. CCl4 administration caused significant decreases in body and reproductive organ weights, testicular catalase (CAT) activity, sperm motility and concentration, and significant increases in lipid peroxidation (LPO) level, abnormal sperm rate and apoptotic index along with some histopathological damages compared with the control group. However, significant improvements were observed in absolute weights of testis and epididymis, all sperm quality parameters, LPO level, apoptotic index and testicular histopathological structure following the administration of CCl4 together with CBO when compared to group given CCl4 only. The findings of this study clearly suggest that CBO has protective effect against damages in male reproductive organs and cells induced by CCl4 .

  4. 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.

  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. 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

  7. Loss of discoidin domain receptor 2 promotes hepatic fibrosis after chronic carbon tetrachloride through altered paracrine interactions between hepatic stellate cells and liver-associated macrophages.

    Science.gov (United States)

    Olaso, Elvira; Arteta, Beatriz; Benedicto, Aitor; Crende, Olatz; Friedman, Scott L

    2011-12-01

    Hepatic stellate cells (HSCs) interact with fibrillar collagen through the discoidin domain receptor 2 (DDR2) in acute hepatic injury, generating increased fibrosis. However, the contribution of DDR2 signaling to chronic liver fibrosis in vivo is unclear, despite its relevance to chronic human liver disease. We administered carbon tetrachloride (CCl(4)) to DDR2(+/+) and DDR2(-/-) mice twice weekly, and liver tissues and isolated HSCs were analyzed. In contrast to changes seen in acute injury, after chronic CCl(4) administration, DDR2(-/-) livers had increased collagen deposition, gelatinolytic activity, and HSC density. Increased basal gene expression of osteopontin, transforming growth factor-β1, monocyte chemoattractant protein-1, and IL-10 and reduced basal gene expression of matrix metalloproteinase-2, matrix metalloproteinase-13, and collagen type I in quiescent DDR2(-/-) HSCs were amplified further after chronic CCl(4). In concordance, DDR2(-/-) HSCs isolated from chronically injured livers had enhanced in vitro migration and proliferation, but less extracellular matrix degradative activity. Macrophages from chronic CCl(4)-treated DDR2(-/-) livers showed stronger chemoattractive activity toward DDR2(-/-) HSCs than DDR2(+/+) macrophages, increased extracellular matrix degradation, and higher cytokine mRNA expression. In conclusion, loss of DDR2 promotes chronic liver fibrosis after CCl(4) injury. The fibrogenic sinusoidal milieu generated in chronic DDR2(-/-) livers recruits more HSCs to injured regions, which enhances fibrosis. Together, these findings suggest that DDR2 normally orchestrates gene programs and paracrine interactions between HSCs and macrophages that together attenuate chronic hepatic fibrosis.

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    Khodadust MR

    2015-06-01

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

  10. Urinary metabonomics study of the hepatoprotective effects of total alkaloids from Corydalis saxicola Bunting on carbon tetrachloride-induced chronic hepatotoxicity in rats using (1)H NMR analysis.

    Science.gov (United States)

    Wu, Fang; Zheng, Hua; Yang, Zheng-Teng; Cheng, Bang; Wu, Jin-Xia; Liu, Xu-Wen; Tang, Chao-Ling; Lu, Shi-Yin; Chen, Zhao-Ni; Song, Fang-Ming; Ruan, Jun-Xiang; Zhang, Hong-Ye; Liang, Yong-Hong; Song, Hui; Su, Zhi-Heng

    2017-03-19

    Chronic liver injury has been shown to cause liver fibrosis due to the sustained pathophysiological wound healing response of the liver, and eventually progresses to cirrhosis. The total alkaloids of Corydalis saxicola Bunting (TACS), a collection of important bioactive ingredients derived from the traditional Chinese folk medicine Corydalis saxicola Bunting (CS), have been reported to have protective effects on the liver. However, the underlying molecular mechanisms need further elucidation. In this study, the urinary metabonomics and the biochemical changes in rats with carbon tetrachloride (CCl4)-induced chronic liver injury due to treatment TACS or administration of the positive control drug-bifendate were studied via proton nuclear magnetic resonance ((1)H NMR) analysis. Partial least squares-discriminate analysis (PLS-DA) suggested that metabolic perturbation caused by CCl4 damage was recovered with TACS and bifendate treatment. A total of seven metabolites including 2-oxoglutarate, citrate, dimethylamine, taurine, phenylacetylglycine, creatinine and hippurate were considered as potential biomarkers involved in the development of CCl4-induced chronic liver injury. According to pathway analysis using identified metabolites and correlation network construction, the tricarboxylic acid (TCA) cycle, gut microbiota metabolism and taurine and hypotaurine metabolism were recognized as the most affected metabolic pathways associated with CCl4 chronic hepatotoxicity. Notably, the changes in 2-oxoglutarate, citrate, taurine and hippurate during the process of CCl4-induced chronic liver injury were significantly restored by TACS treatment, which suggested that TACS synergistically mediated the regulation of multiple metabolic pathways including the TCA cycle, gut microbiota metabolism and taurine and hypotaurine metabolism. This study could bring valuable insight to evaluating the efficacy of TACS intervention therapy, help deepen the understanding of the

  11. Protective effects of the apigenin-O/C-diglucoside saponarin from Gypsophila trichotoma on carbone tetrachloride-induced hepatotoxicity in vitro/in vivo in rats.

    Science.gov (United States)

    Simeonova, Rumyana; Kondeva-Burdina, Magdalena; Vitcheva, Vessela; Krasteva, Ilina; Manov, Vassil; Mitcheva, Mitka

    2014-01-15

    This study investigated the hepatoprotective activity of saponarin, isolated from Gypsophila trichotoma Wend., using in vitro/in vivo hepatotoxicity model based on carbone tetrachloride (CCl₄)-induced liver damage in male Wistar rats. The effect of saponarin was compared with those of silymarin. In vitro experiments were carried out in primary isolated rat hepatocytes. Cell incubation with CCl₄ (86 μmol l⁻¹) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH and elevation in MDA quantity. Cell pre-incubation with saponarin (60-0.006 μg/ml) significantly ameliorated CCl₄-induced hepatic damage in a concentration-dependent manner. These results were supported by the following in vivo study. Along with decreased MDA quantity and increased level of cell protector GSH, seven day pre-treatment of rats with saponarin (80 mg/kg bw; p.o.) also prevented CCl₄ (10%, p.o.)-caused oxidative damage by increasing antioxidant enzyme activities (CAT, SOD, GST, GPx, GR). Biotransformation phase I enzymes were also assessed. Administered alone, saponarin decreased EMND and AH activities but not at the same extent as CCl₄ did. However, pre-treatment with saponarin significantly increased enzyme activities in comparison to CCl₄ only group. The observed biochemical changes were consistent with histopathological observations where the hepatoprotective effect of saponarin was comparative to the effects of the known hepatoprotecor silymarin. Our results suggest that saponarin, isolated from Gypsophila trichotoma Wend., showed in vitro and in vivo hepatoprotective and antioxidant activity against CCl₄-induced liver damage.

  12. Puerarin attenuates carbon tetrachloride-induced liver oxidative stress and hyperlipidaemia in mouse by JNK/c-Jun/CYP7A1 pathway.

    Science.gov (United States)

    Ma, Jie-Qiong; Ding, Jie; Zhao, Hai; Liu, Chan-Min

    2014-11-01

    Puerarin (PU), a natural flavonoid, has been reported to have many benefits and medicinal properties. The aim of this study was to investigate the effects of puerarin on hepatic oxidative stress and hyperlipidaemia in mice exposed to carbon tetrachloride (CCl4). Male ICR mice were injected with CCl4 with or without puerarin co-administration (200 and 400 mg/kg intragastrically once-daily) for 8 weeks. Our data showed that puerarin significantly prevented CCl4-induced hepatotoxicity, indicated by both diagnostic indicators of the liver damage (serum aminotransferase levels) and histopathological analysis. Puerarin decreased the thiobarbituric acid reactive substances (TBARS) and the protein carbonyl content (PCO) in the liver of CCl4-treated mice. Puerarin also restored the levels of reduced glutathione (GSH) and total antioxidant capacity (TAC) in the liver. Furthermore, the increase in serum cholesterol, triglycerides and low-density lipoproteins (LDL) induced by CCl4 was effectively suppressed by puerarin. The high-density lipoprotein (HDL) level in the CCl4 treatment mice was also increased by puerarin. Western blot analysis showed that puerarin remarkably inhibited hyperlipidaemia by regulating the expression of phosphorylated Jun N-terminal kinases (JNK), phosphorylated c-Jun protein and cholesterol 7a-hydroxylase (CYP7A1) in the liver of CCl4-treated mice. Altogether, these results suggest that puerarin could protect the CCl4-induced liver injury and hyperlipidaemia by reducing reactive oxygen species S production, renewing the total antioxidant capacity and influencing expression of hepatic lipid biosynthesis and metabolism genes.

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

    Science.gov (United States)

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

    2016-09-01

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

  14. 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.

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

    Science.gov (United States)

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

    2009-10-01

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

  16. 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.

  17. 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.

  18. Evaluating genotoxicity data to identify a mode of action and its application in estimating cancer risk at low doses: A case study involving carbon tetrachloride.

    Science.gov (United States)

    Eastmond, David A

    2008-03-01

    In the new USEPA cancer risk assessment guidelines, mode of action (MoA) information, combined with a determination of whether or not a chemical is mutagenic, plays an important role in determining whether a linear or nonlinear approach should be used to estimate cancer risks at low doses. In this article, carbon tetrachloride (CT) is used as an example to illustrate how mixed genotoxicity data can be evaluated and used to identify a likely MoA. CT is essentially negative in inducing gene mutations in Salmonella, but is consistently positive in inducing recombination and aneuploidy in fungi. Negative or equivocal results were seen in most in vitro and in vivo studies in mammals, including mutation studies in transgenic mice. However, DNA adducts, primarily those derived from oxidation- and lipid-peroxidation-derived products as well as DNA double-strand breaks and micronucleated cells, have been seen repeatedly in the liver of CT-treated animals. On the basis of the weight of evidence, CT should not be considered a directly mutagenic agent. Mutagenic as well as other genotoxic effects, as they occur, will most likely be generated through indirect mechanisms resulting from oxidative and lipid peroxidative damage and/or damage occurring during necrosis or apoptosis. As key events in this process are expected to occur in a nonlinear fashion, the expected relationship between CT dose and carcinogenic response in the liver is likely to be nonlinear with a steep dose response. This conclusion is consistent with rodent cancer bioassay results in which steep nonlinear dose responses have been seen.

  19. P2X7 receptor-NADPH oxidase axis mediates protein radical formation and Kupffer cell activation in carbon tetrachloride-mediated steatohepatitis in obese mice.

    Science.gov (United States)

    Chatterjee, Saurabh; Rana, Ritu; Corbett, Jean; Kadiiska, Maria B; Goldstein, Joyce; Mason, Ronald P

    2012-05-01

    While some studies show that carbon tetrachloride-mediated metabolic oxidative stress exacerbates steatohepatitic-like lesions in obese mice, the redox mechanisms that trigger the innate immune system and accentuate the inflammatory cascade remain unclear. Here we have explored the role of the purinergic receptor P2X7-NADPH oxidase axis as a primary event in recognizing the heightened release of extracellular ATP from CCl(4)-treated hepatocytes and generating redox-mediated Kupffer cell activation in obese mice. We found that an underlying condition of obesity led to the formation of protein radicals and posttranslational nitration, primarily in Kupffer cells, at 24h post-CCl(4) administration. The free radical-mediated oxidation of cellular macromolecules, which was NADPH oxidase and P2X7 receptor-dependent, correlated well with the release of TNF-α and MCP-2 from Kupffer cells. The Kupffer cells in CCl(4)-treated mice exhibited increased expression of MHC Class II proteins and showed an activated phenotype. Increased expression of MHC Class II was inhibited by the NADPH oxidase inhibitor apocynin , P2X7 receptor antagonist A438709 hydrochloride, and genetic deletions of the NADPH oxidase p47 phox subunit or the P2X7 receptor. The P2X7 receptor acted upstream of NADPH oxidase activation by up-regulating the expression of the p47 phox subunit and p47 phox binding to the membrane subunit, gp91 phox. We conclude that the P2X7 receptor is a primary mediator of oxidative stress-induced exacerbation of inflammatory liver injury in obese mice via NADPH oxidase-dependent mechanisms.

  20. The inhibitory effects in vitro of phenothiazines and other drugs on lipid-peroxidation systems in rat liver microsomes, and their relationship to the liver necrosis produced by carbon tetrachloride

    Science.gov (United States)

    Slater, T. F.

    1968-01-01

    1. The effects of several phenothiazine derivatives on lipid-peroxidation systems in rat liver microsomes were studied and the results are considered in relation to the hepatotoxic action of carbon tetrachloride. 2. The lipid-peroxidation system coupled to NADPH2 oxidation and stimulated by an ADP–Fe2+ mixture is strongly inhibited in vitro by promethazine (50% inhibition at 29μm). Chlorpromazine and Stelazine also inhibit the peroxidation system but are less effective than promethazine. 3. The effects of promethazine on three other systems involving oxygen uptake (sulphite oxidation, orcinol oxidation and mitochondrial succinate oxidation) were also studied. Promethazine does not inhibit these systems to the same extent as it does the NADPH2–ADP–Fe2+ lipid-peroxidation system. 4. Promethazine also produces an inhibition of the NADPH2–ADP–Fe2+ system in liver microsomes after administration in vivo. It is concluded that the inhibition involves the interaction of the drug (or a metabolite of it) with the microsomal electron-transport chain. 5. Several other compounds known to protect the rat against liver necrosis after the administration of carbon tetrachloride were tested for inhibitory action on the NADPH2–ADP–Fe2+ system. No clear correlation was observed between effectiveness in vivo as a protective agent and inhibitory effects on the NADPH2–ADP–Fe2+ system in vitro. 6. Promethazine was found to inhibit the stimulation of lipid peroxidation produced in rat liver microsomes by low concentrations of carbon tetrachloride. This effect occurs at a concentration similar to that observed in vivo after administration of a normal clinical dose. PMID:4388686

  1. 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

  2. Study on mechanism of rat renal injury induced by carbon tetrachloride%四氯化碳诱发大鼠肾损伤的机制研究

    Institute of Scientific and Technical Information of China (English)

    阳建莹; 李文良; 李先华; 肖业伟

    2012-01-01

    Objective To explore the toxic mechanism of chronic kidney injury induced by carbon tetrachloride(CCl4)in rat. Methods Healthy Wistar rats were randomly divided into the control group and exposure group. Normal saline was intraperitoneally injected in control group. CCl4 soybean oil solution was intraperitoneally injected in exposure group. Blood serum samples of all rats were collected in the 8th week for detecting BUN, CRE, SOD and MDA contents. In addition, kidney tissues were collected in the 8th week for measuring SOD activity, MDA content and observing pathologic findings. Results Levels of BUN and CRE in serum were significantly higher (P< 0. 01), levels of MDA and NO in serum and kidney tissue increased significantly, while SOD activity was significantly lower than the control group(P<0. 01). Severe morphological changes were clearly seen in rat renal of the exposure group. Conclusions CCl4 could induce renal injury. The mechanism might be closely related with increased free radicals and lipid peroxidation.%目的 探讨四氯化碳(CCl4)致大鼠慢性肾损伤的毒性机制.方法 将健康的Wistar大鼠随机分为对照组和染毒组,对照组腹部皮下注射生理盐水;染毒组腹部皮下注射CCl4大豆油溶液.于第8周末分别检测血清中尿素氮(BUN)和肌酐(CRE)含量;血清和肾组织中丙二醛(MDA)、NO含量及超氧化物歧化酶(SOD)的活力,并作肾组织病理检查.结果 与对照组比较,染毒组血清中BUN、CRE明显增高(P<0.01),血清和肾组织中SOD活力明显降低、MDA和NO含量增加(P<0.01).染毒组肾组织病理学变化明显.结论 CCl4能诱发肾脏损伤,其机制可能与体内自由基增加和细胞脂质过氧化有关.

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

    Energy Technology Data Exchange (ETDEWEB)

    Blas, Maite de, E-mail: maite.deblas@ehu.eus [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Uria-Tellaetxe, Iratxe; Gomez, Maria Carmen [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain); Navazo, Marino [University College of Engineering of Vitoria-Gasteiz, University of the Basque Country UPV/EHU (Spain); Alonso, Lucio; García, Jose Antonio; Durana, Nieves; Iza, Jon; Ramón, Jarol Derley [School of Engineering of Bilbao, University of the Basque Country UPV/EHU (Spain)

    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 2014–2015 years). Median yearly CTC mixing ratios were slightly higher in the urban area (120 pptv) than in VNP (80–100 pptv). 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. - Highlights: • A methodology was developed to measure CTC using GC-MSD and GC-FID. • CTC ongoing sources were noticed in an industry surrounded urban area. • No noticeable nearby CTC sources impacted the rural site. • Long-term CTC trend in agreement

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

    Science.gov (United States)

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

    2015-01-01

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

  5. 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.

  6. 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

  7. (Z)-5-(4-methoxybenzylidene)thiazolidine-2,4-dione protects rats from carbon tetrachloride-induced liver injury and fibrogenesis

    Institute of Scientific and Technical Information of China (English)

    Zhi-Zhi Chen; Li-Juan Chen; Yu-Quan Wei; Zheng-Lin Wang; Chong-Yang Deng; Hao Zheng; Xian-Huo Wang; Liang Ma; Xia Ye; Ying-Hua Ma; Cai-Feng Xie

    2012-01-01

    AIM:To evaluate the hepatoprotective roles of (Z)-5-(4-methoxybenzylidene)thiazolidine-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 SKLB010on 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 were randomly divided into 2

  8. Adopting Vacuum Blood Collection Tube to Detect Chloroform and Carbon Tetrachloride in Water by Headspace Gas Chromatography%真空采血管顶空气相色谱法检测水中三氯甲烷、四氯化碳

    Institute of Scientific and Technical Information of China (English)

    黄志强

    2013-01-01

    Vacuum blood collection tube was adopted to detect chloroform and carbon tetrachlo-ride in water by headspace gas chromatography. Results showed that the linear range of chloroform was 10.0~50.0μg/L and carbon tetrachloride was 0.5~4.0μg/L, which showed a good linear rela-tion. The r value was 0.999 4 and 0.999 8. RSD of chloroform and carbon tetrachloride was 1.64%~2.27% and 1.45%~2.40% respectively. Recoveries of chloroform and carbon tetrachloride were 97.0%~103.5% and 94.0%~103.2% respectively. This method is simple and has good precision and accuracy, and suitable for detecting chloroform and carbon tetrachloride in water.%采用真空采血管顶空填充柱气相色谱法测定水中三氯甲烷和四氯化碳,结果表明,三氯甲烷在10.0~50.0μg/L,四氯化碳在0.5~4.0μg/L浓度范围内呈良好线性关系,其r值分别为0.9994和0.9998;三氯甲烷和四氯化碳RSD分别在1.64%~2.27%和1.45%~2.40%之间;加标回收率分别在97.0%~103.5%和94.0%~103.2%之间。该方法操作简单,具有较好的灵敏度和准确度,适用于水中三氯甲烷和四氯化碳的检测。

  9. 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.

  10. 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

  11. Establishment of carbon tetrachloride-induced acute liver injury model in mice%四氯化碳致小鼠急性肝损伤动物模型建立方法的研究

    Institute of Scientific and Technical Information of China (English)

    周琼; 刘芳萍; 刘颖姝; 赵玉林; 李昌文; 李睿; 张秀英

    2012-01-01

    通过对染毒途径、剂量和时间的研究,建立四氯化碳(CCl4)致小鼠急性肝损伤模型.采取腹腔注射和灌胃两种途径给予小鼠1% CCl4,染毒后24h检测血清转氨酶含量,并观察肝脏病变.结果显示,灌胃组比腹腔注射组小鼠血清转氨酶变化个体差异小,肝脏病变明显,病灶分布均匀,且与实际中毒途径一致,故采用灌胃方法进行确定染毒剂量及时间试验.分别以0.125%、0.25%、0.35%、0.5%的CCl4给小鼠灌胃,染毒24h后检测血清转氨酶含量,确定最佳染毒剂量.以该浓度给小鼠灌胃,分别于染毒后2、6、12、16、20、24、28、32、48h检测小鼠血清转氨酶含量.结果表明,灌胃0.35% CCl4,小鼠血清转氨酶升高与对照组相比差异极显著(P<0.01),此浓度灌胃后,20h血清转氨酶含量显著升高(P<0.01),24h达到最高值,与对照组相比差异极显著(P<0.01).因此,以0.35%四氯化碳,按0.1mL·10g-1体重灌胃,染毒24h,可建立较理想的小鼠急性肝损伤模型.%Established the model of carbon tetrachloride-induced acute liver injury in mice by investigating the optimal exposure pathway, dose and time. Mice were prepared with 1% CCU by intraperitoneal injection and gavage respectively. Serum transaminase levels were detected and liver lesions were examined after 24 h. The results showed that individual difference of serum transaminase level in gavage group was smaller than intraperitoneal injection group, liver lesions were more uniform. Optimal dose and time was investigated by gavage because it has the same poisoning way with reality. Mice were given carbon tetrachloride in oil solution by gavage, with concentration of 0.125%, 0.25%, 0.35% and 0.5%. Detected serum transaminase levels after 24 h to measure optimal exposure dose. Serum transaminase levels was detected at 2,6,12,16, 20, 24, 28, 32, 48 h after mice were expoed to optimal dose of CCU. The results showed that mice received 0.35% CCU

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Chin-Kai Tseng

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

  14. 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.

  15. 四氯化碳显色目视比色法测定溶解氧方法的研究%Research on Determining Dissolved Oxygen with Visual Colorimetry of Carbon Tetrachloride

    Institute of Scientific and Technical Information of China (English)

    韩丽媛

    2011-01-01

    This paper introduces the study of determination of dissolved oxygen by visual colorimetry with carbon tetrachloride. This method is proved quick and exact, clear in showing the experimental results and suit- able for emergency measurement by comparison of the choices of standard reagents, extraction solvents, the quantity of potassium iodide (KI) and tset of stability, denoisingt, environmental temperature and accuracy and precision.%本文介绍了四氯化碳显色目视比色法测定溶解氧方法的研究过程,通过时分析方法中,标准试剂的选择,萃取剂的选择,碘化钾(K1)用量的选择,及稳定性实验,消除干扰实验,环境温度实验,方法准确度及精密度实验,表明此方法快速、准确、分析结果直观、适合应急监测。

  16. Titanium tetrachloride burns to the eye.

    OpenAIRE

    Chitkara, D K; McNeela, B. J.

    1992-01-01

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

  17. Amelioration of SD rats acute liver injury model induced by carbon tetrachloride%CCl4致SD大鼠急性肝损伤模型制作的改进

    Institute of Scientific and Technical Information of China (English)

    张旻; 唐晓鹏; 李代强; 童敏; 王文龙

    2004-01-01

    Objective: The purpose of this study was to optimize carbon tetrachloride-induced hepatotoxicity in the rat with respect to dose and time course. Method: Carbon tetrachloride with different dosage was given to SD rats by abdominal injection. Rat ALT and AST in serum were analyzed 48 h and rats liver were observed with routine pathology technique, to determine mice liyers' functional and morphological changes after administration. Results: The serum level of ALT and AST increased significantly in 3A~7A CCl4 groups compared with the control group (P<0.05 or P<0.01). The pathological changes in can be seen in every ccl4 group, the damnification degree of liver cells were remarkably aggravated with the control group. Deceased rats were seen in 6A and 7A group. Conclusion: Ameliorated acute liver injury model of mice was established, which has definite liver injury with lower mortality rate and less damnification to other organs, can be used for the mechanism and treatment research of acute liver injury.%目的本文筛选CCl4致SD大鼠急性肝损伤模型的最佳给药浓度和剂量,追踪观察模型大鼠肝损伤后修复过程.方法本文采用随机对照分组的研究方法,对不同的SD大鼠模型组给予不同剂量的CCl4一次性腹腔注射.给药后48h检测大鼠血清ALT,AST.各组随机处死一只SD大鼠,取肝组织制成病理切片镜下观察.追踪观察筛选后的CCl4模型大鼠肝组织病理变化恢复情况.结果本实验发现3A-7A组的ALT,AST较对照组明显升高(P<0.05或P<0.01),随着CCl4的剂量的增加,大鼠肝组织的病理损伤加重,6A和7A组可见自然死亡大鼠.结论本试验筛选了CCl4致SD大鼠急性肝损伤模型的较好CCl4的剂量.该模型肝损伤明显,死亡率低,对其他重要脏器影响小,可作为急性肝损伤研究的较好模型.

  18. 四氯化碳皮下注射诱导兔肝硬化模型的建立%Development of Rabbit Liver Cirrhosis by Carbon Tetrachloride Subcutaneous Injection

    Institute of Scientific and Technical Information of China (English)

    于晓红; 金博; 邱慧彬; 付山峰; 路平

    2011-01-01

    Objective To establish a liver cirrhosis animal model in rabbit through carbon tetrachloride subcutaneous injections. Methods Total 50 male rabbits were divided into 2 groups randomly. The experimental group (n =35 ) were injected 50% CCl4-olive oil subcutaneously with the dosage 0. 23ml/kg in the gluteal region,twice a week. The same dosage of olive oil was injected in the control group by a same way. The liver function test and the histopathology were investigated at the end of 4,8,12weeks. Results The hepatic fibrosis progressed gradually as continuous injection of the toxin. The ALT,AST,GGT increased obviously. At the end of 12 weeks,the albumin/globulin ratio was reversed. A typical pathology of liver cirrhosis was detected. In the control group the liver function and histology were normal. The mortality is 20% at the end of experiment and the achievement ratio of animal model is 83%. Conclusion The rabbit liver cirrhosis model can be established by subcutaneous injection of carbon tetrachloride. This animal model can be used in liver cirrhosis experiment.%目的 应用四氯化碳(CCI4)皮下注射方法,建立兔肝硬化动物模型.方法 50只雄性新西兰大白兔随机分为实验组(n=35)和对照组(n=15).实验组臀部皮下注射50%CCI4橄榄油0.23 mL/kg,每周2次,对照组注射等量橄榄油.分别于4 w、8 w和12 w末检测各组兔肝脏功能及组织病理学变化.结果 随时间延长,实验组兔肝脏纤维化程度逐渐加重,血清谷丙转氨酶(ALT)、谷草转氨酶(AST)和γ-谷氨酰转肽酶(GGT)明显升高,12 w末出现白蛋白/球蛋白比例倒置,可观察到典型肝硬化病理表现,兔肝组织出现典型的假小叶结构,动物死亡率20%,造模成功率83%.对照组肝脏功能正常,肝脏组织学结构正常.结论 此方法可成功地建立兔肝硬化动物模型,该方法成功率高,可用于相关实验研究.

  19. 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.

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

    Institute of Scientific and Technical Information of China (English)

    赵秀琴; 黄荣谊

    2011-01-01

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

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

    Science.gov (United States)

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

    2007-10-01

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

  2. Mice deficient in N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase exhibit enhanced liver fibrosis and delayed recovery from fibrosis in carbon tetrachloride-treated mice

    Directory of Open Access Journals (Sweden)

    Hiroko Habuchi

    2016-08-01

    Results and conclusion: On 2 days after cessation of CCl4 administration, higher fibrosis was observed in KO mice than in WT mice by Sirius Red staining. Serum alanine aminotransferase activity was higher in KO mice than in WT mice. Hydroxyproline contents and Sirius Red staining showed that repair of liver fibrosis in the recovery stages appeared to be delayed in KO mice. Expression of mRNA of matrix metalloproteinase (MMP-2, MMP-13 and versican peaked at 2 days after cessation of CCl4 administration and was higher in KO mice than in WT mice. Expression of MMP-9 in the recovery stage was lower in KO mice than in WT mice. Our findings demonstrate that defect in GalNAc4S-6ST, which resulted in disappearance of CS/DS containing GalNAc(4,6SO4, appear to contribute to progression of liver fibrosis, delayed recovery from fibrosis, and various changes in the expression of proteoglycans and MMPs in carbon tetrachloride–treated mice.

  3. 番茄红素对CCl4诱导的正常肝细胞株HL-7702损伤的影响%Effect of lycopene on hepatocyte injuries induced by carbon tetrachloride

    Institute of Scientific and Technical Information of China (English)

    赵凯

    2013-01-01

    目的 体外观察番茄红素对人正常肝细胞株HL-7702细胞活力及凋亡的影响,探讨其对肝细胞的保护作用.方法 体外培养人正常肝细胞株HL-7702,建立CCl4肝损伤模型,终浓度为2、5、10 μmol·L-1的番茄红素干预处理,MTT法测定细胞活性、Horchest33342染色及TUNEL检测观察细胞凋亡.结论 番茄红素在2~10 μmol·L-1浓度范围内的对肝细胞无毒性,可抑制CCl4所致肝细胞活性下降,减少CCl4所致的肝细胞凋亡,一定剂量范围内与番茄红素浓度相关.结论番茄红素对正常肝细胞HL-7702具有保护作用.%Objectives To observe the effect of lycopene on the growth and apoptosis of HL -7702 hepatocyte strain and to explore the protection on hepatocyte. Methods The exoteric hepatic injuries model , caused by carbon tetrachloride ( CC14 ) , which was interfered by lycopene(at concentrations of 2,5,10 μmol? L-1),was established with well-cultivated HL-7702 hepatocyte strain.The growth conditions were detected by MTT method and apoptosis was observed with Horchest 33342 and TUNEL staining. Results Toxicity to hepato— cytes of lycopene ,at concentrations from 2 μmol?L-1 to 10 μmol?L-1,was not observed. Hepatocytes had some protective effects on the vigor impact induced , and could reduce the hepatic apoptosis provoked by CC14, and correlation with the concentrations of lycopene . Conclusions Lycopene had certain protective effects on hepatocyte .

  4. 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.

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

  6. 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.

  7. Determination of Trichloromethane and Carbon tetrachloride in water by Headspace Gas Chromatography%顶空气相色谱法测定饮用水中的三氯甲烷及四氯化碳

    Institute of Scientific and Technical Information of China (English)

    杨卫花; 李颖; 赵浩军; 王坤

    2012-01-01

    A method for the determination of trichloromethane and carbon tetraehloride in water by headspaee gas chromatography was studied. The results showed that the recovery was ranged between 92%- 99% and the relative standard deviations were ranged between 2.1% - 6.3 %. This method is accurate and the pre-proeessing of this method is simple.%利用国产顶空进样设备及GC-ECD(气相色谱-电子捕获检测器)建立了水中挥发性组份三氯甲烷、四氯化碳的测定方法。该方法的相对标准偏差为2.1—6.3%,样品的回收率为92%~99%。方法简化了样品处理过程,检出限与重复性均达到相关国家标准要求。

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

    Institute of Scientific and Technical Information of China (English)

    熊杰; 孙方中; 罗晓慧; 王丽萍

    2011-01-01

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

  9. Determination of Carbon Dioxide in Refined Titanium Tetrachloride by Infrared Spectroscopy%红外光谱法测定精四氯化钛中二氧化碳的含量

    Institute of Scientific and Technical Information of China (English)

    宋光林; 罗运军; 李晋庆; 谭红

    2015-01-01

    精 TiCl4是海绵钛生产的关键环节,且海绵钛中杂质碳和氧(C,O)与精 TiCl4中杂质 C 和 O 含量成4倍富集关系,因此,钛材质量控制的关键是控制精 TiCl4中杂质 C 和 O 的含量。为了控制精 TiCl4中的C 和 O,需要分析 C 和 O 杂质的来源,对精 TiCl4中杂质进行严格控制。测定精 TiCl4中 CO2的含量,对精TiCl4中杂质 C 和 O 的分析具有重要意义。CO2具有红外吸收谱线,因而能够利用红外光谱实现测定,然而精 TiCl4与空气中水气接触极易发生水解反应,生成强腐蚀性的盐酸烟雾,不能使用常规的红外吸收池进行测定。根据 Lambert-Beer 定律,被测组分浓度(cx )与吸光度(A)~样品光程(L)曲线的斜率成正比,本研究利用波数范围7800~440 cm-1的硒化锌窗片(10 mm×1 mm)和玻璃池体(42,22,12,7和4 mm 光程)组装成一套红外吸收池,采用加标法测定精 TiCl4中 CO2杂质含量。实验得出 CO2的 检 出 限 为0.92 mg· kg-1,样品回归方程Y =0.0311X ,相关系数 r 为0.9972,加标 CO2样品的回归方程Y =0.1317X ,相关系数 r 为0.9986,线性关系较好,测定精 TiCl4中 CO2含量为1.53 mg·kg-1,标准偏差(SD)为0.04 mg· kg-1,方法相对标准偏差(RSD)在0.53%~1.27%之间,加标回收率在89.2%~96.8%。此红外吸收池安全简便、容易拆洗、可重复使用,通过一次加标样品定量分析精 TiCl4中 CO2含量,可满足精 TiCl4中 CO2分析的要求。%Refined TiCl4 is the key procedure in producing titanium sponge.Besides,the content of carbon and oxygen (C and O)impurities in titanium sponge and that of C and O impurities in refined TiCl4 presents the 4-times enrichment relationship.Therefore,the content control of the C and O impurities in refined TiCl4 be-comes the key part for the quality control of titanium material.In order to control

  10. Destructive adsorption of carbon tetrachloride on lanthanum and cerium oxides

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Rosynek, M.P.; Lunsford, J.H.

    1999-01-01

    The destructive adsorption of CCl4 on La2O3 and CeO2 in the absence of any oxidant, such as oxygen, has been studied by X-ray photoelectron spectroscopy and insitu Raman spectroscopy as a function of the reaction temperature and the amount of CCl4 injected. La2O3 was much more reactive than CeO2, an

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

    NARCIS (Netherlands)

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

    2001-01-01

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

  12. Prophylactic effect of four prescriptions of traditional Chinese medicine on α-naphthylisothiocyanate and carbon tetrachloride induced toxicity in rats%中医四方剂对异硫氰酸α-萘酯及四氯化碳诱发的大鼠肝损伤的预防作用

    Institute of Scientific and Technical Information of China (English)

    林国瑞; 陈荣洲; 曹伟; 林俊清; 林昭庚; 蔡金川

    2001-01-01

    目的:探讨四种中医方剂对实验性肝损伤的作用.方法:事先给予四磨饮(SMY)、桂枝茯苓丸(GFW)、泻青丸(XQW)及四逆散(SNS)的水提取物,对异硫氰酸α-萘酯(ANIT)、四氯化碳(CCl4)诱发的肝损伤,进行预防保肝评估,包括生化指标、肝组织脂质过氧化及组织病理.结果:大鼠给予ANIT后,总胆红素(TBI)、碱性磷酸酶(ALP)、谷草转氨酶(GOT)、谷丙转氨酶(GPT)皆有明显升高,组织病理显示胆道郁阻及局部坏死.四磨饮、泻青丸及四逆散在生化指标及病理观察上皆有显著的预防效果.在四氯化碳诱发的肝损伤实验中,四方剂对肝功能生化指标与肝组织脂质过氧化及病理变化等,皆显示出预防效果.结论:虽然异硫氰酸α-萘酯、四氯化碳的肝损伤机制不同,但此四方都有不同程度的保肝作用,且其作用是由多重机制来完成的.方剂处方均由君臣佐使的配合来设计,显示对不同毒物的多重保护作用.%AIM: To study the prophylactic effects of four Chinese traditional prescriptions against experimental liver injury. METHODS: Liver toxins, a-naphthylisothiocyanate (ANIT), and carbon tetrachloride (CCl4) were used to induce acute liver injury. Simo Yin (SMY), Guizhi Fuling Wan (GFW), Xieqing Wan (XQW), and Sini San (SNS) were fed (500 mg/kg, in saline, po ) to the rats before toxin administration. All the animals were killed 48 h after toxin insulted. Serum index of liver function and hepatic lipid peroxidation (LPO) were estimated. Histopathological observation was conducted simultaneously. RESULTS: The rars treated with ANIT exhibited elevations of serum total bilirubin (TBI),alkaline phosphatase ( ALP ), glutamate-oxalatetransaminase ( GOT ), glutamate-pyruvate-transaminase (GPT), as well as cholestasis and parenchyma necrosis. In rats, challenged with ANIT, receiving the pretreatment of prescriptions of SMY, XQW, and SNS, the biochemical and morphological parameters of liver injury

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  14. 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

  15. 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

  16. In vitro and in vivo hepatoprotective and antioxidant effects of sily-marin against carbon tetrachloride-induced hepatocyte damage in crucian carp Carassius auratus%水飞蓟素对四氯化碳致鲫肝(细胞)损伤的保护和抗氧化作用

    Institute of Scientific and Technical Information of China (English)

    贾睿; 曹丽萍; 杜金梁; 徐跑; 殷国俊

    2013-01-01

    We evaluated the hepatoprotective and antioxidant effects of silymarin (SM) against carbon tetrachlo-ride (CCl4)-induced hepatocyte and liver injury in crucian carp (carassius auratus) in vitro and in vivo. In vitro, 100, 300, and 600 μg/mL silymarin were added to carp primary hepatocytes before (pre-treatment), after (post-treatment), or both before and after(pre- and post-treatment) incubation of the hepatocytes with 8 mmol/L CCl4 in culture medium. We then measured lactate dehydrogenase (LDH), glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), and malondialdehyde (MDA) levels. In vivo, crucian carp were fed a diet containing one of three concentrations of silymarin [0.1, 0.5, or 1 g/kg (diet)] for 60 d. Each fish was then given a single intraperitoneal injection of CCl4 (30%in arachis oil), and 72 h after the injection, we collected blood and liver samples from each fish. We measured the serum biochemical indices and liver tissue indices described above. Silymarin improved cell viability and decreased GPT, GOT, LDH, MDA, and SOD activ-ity. Administration of silymarin at 0.5 and 1 g/kg diet for 60 d prior to CCl4 intoxication significantly decreased GPT, GOT, and LDH activity, increased levels of total protein and albumin in the serum, and increased SOD, glu-tathione peroxidase, catalase, glutathione, total antioxidant capacity, and MDA formation in liver tissue. However, these parameters, except for LDH, were not significantly altered in fish fed 0.1 g silymarin per kg diet. Our data suggest that silymarin exhibits a protective effect against CCl4-induced hepatotoxicity in fish, which is likely re-lated to its antioxidant activity. We suggest that silymarin may be used as a hepatoprotective agent against fish liver diseases.%  为了评价水飞蓟素(Silymarin, SM)对鲫(Cyprinus carpio)肝(细胞)的保护和抗氧化作用,分别从体外和体内两个方面探讨其作用效果。在体外,利用8

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

    Institute of Scientific and Technical Information of China (English)

    郭杞兰; 黄月红; 陈治新; 王小众

    2014-01-01

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

  18. 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

  19. Toll-Like Receptor 3 Gene Deficiency Aggravates Carbon Tetrachloride-Induced Liver Fibrosis in Mice%Toll样受体3基因缺陷促进四氯化碳诱导的小鼠肝纤维化损伤

    Institute of Scientific and Technical Information of China (English)

    薛如意; 张丹瑛; 吴昊; 刘韬韬; 董玲; 沈锡中

    2016-01-01

    使肝组织中炎性因子 TNF‐α、IL‐6和 MCP‐1以及促纤维化分子TGF‐β、TIMP1和PDGFR表达升高。结论:TLR3基因缺陷可促进四氯化碳诱导的肝纤维化小鼠肝组织中的胶原沉积和肝星状细胞激活,促进肝组织炎性因子释放,使肝促纤维化分子上调。以上提示,T L R3是肝纤维化病理过程中的一个保护性基因。%Objective:To investigate the effect of Toll‐like receptor 3(TLR3) gene deficiency on the degree of liver fibrosis in mouse model of carbon tetrachloride(CCl4 )‐induced liver fibrosis .Methods :A total of 20 wild‐type male mice and 20 male mice with TLR3 gene deficiency (TLR3‐/‐) were divided into wild‐type control group and wild‐type model group ,TLR3‐/‐ control group and TLR3‐/‐ model group ,respectively ,with 10 mice in each group .The control group was injected with corn‐oil by intraperitoneal injection while the model group was injected with CCl4 by intraperitoneal injection .After 8 weeks ,blood sample wascollectedandserumlevelofalanineaminotransferase(ALT),aspartatetransaminase(AST),totalbilirubin(TBIL),and albumin(Alb) was analyzed by automatic biochemical analyzer .And the degree of collagen deposition in liver tissue was evaluated by Masson trichrome staining .And the activation of hepatic stellate cells was detected by immunohistochemistry staining of α‐smooth muscle actin(α‐SMA).And hydroxyproline content of liver tissue was detected with detection kit . Furthermore ,real‐time fluorescence polymerase chain reaction was used to detect the expression of liver fibrotic marker type I collagen ,and inflammatory cytokines including tumor necrosis factor‐alpha (TNF‐α) , interleukin‐6 (IL‐6 ) and monocyte chemotactic protein‐1(MCP‐1) ,as well as pro‐fibrotic molecule including transforming growth factor‐beta (TGF‐β) ,tissue inhibitor of metalloproteinase 1(TIMP1) and platelet‐derived growth factor receptor(PDGFR) .Results:TLR3 gene deficiency had no

  20. Plasma quench production of titanium from titanium tetrachloride

    Energy Technology Data Exchange (ETDEWEB)

    Sears, J.W.

    1994-10-01

    This project, Plasma Quench Production of Titanium from Titanium Tetrachloride, centers on developing a technique for rapidly quenching the high temperature metal species and preventing back reactions with the halide. The quenching technique chosen uses the temperature drop produced in a converging/diverging supersonic nozzle. The rapid quench provided by this nozzle prevents the back reaction of the halide and metal. The nature of the process produces nanosized particles (10 to 100 nm). The powders are collected by cyclone separators, the hydrogen flared, and the acid scrubbed. Aluminum and titanium powders have been produced in the laboratory-scale device at 1 gram per hour. Efforts to date to scale up this process have not been successful.

  1. Oxidation of carbon tetrachloride, bromotrichloromethane, and carbon tetrabromide by rat liver microsomes to electrophilic halogens

    Energy Technology Data Exchange (ETDEWEB)

    Mico, B.A. (National Inst. of General Medical Sciences, Bethesda, MD); Branchflower, R.V.; Pohl, L.R.; Pudzianowski, A.T.; Loew, G.H.

    1982-01-11

    In order to determine whether CCl/sub 4/, CBrCl/sub 3/, CBr/sub 4/ or CHCl/sub 3/ undergo oxidative metabolism to electrophilic halogens by liver microsomes, they were incubated with liver microsomes from phenobarbital pretreated rats in the presence of NADPH and 2,6-dimethylphenol. The analysis of the reaction mixtures by capillary gas chromatography mass spectrometry revealed that 4-chloro-2,6-dimethylphenol was a metabolite of CCl/sub 4/ and CBrCl/sub 3/ whereas 4-bromo-2,6-dimethylphenol was a metabolite of CBr/sub 4/. The formation of the metabolites was significantly decreased when the reactions were conducted with heat denatured microsomes, in the absence of NADPH or under an atmosphere of N/sub 2/. These results indicate that the chlorines of CBrCl/sub 3/ and CCl/sub 4/ and the bromines of CBr/sub 4/ are oxidatively metabolized by rat liver microsomes to electrophilic and potentially toxic metabolites.

  2. Kinetic equation for the reaction of titanium tetrachloride with hydride functional groups of diamond

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, A.B.; Smirnov, E.P.

    1989-02-01

    This work is devoted to the study of the kinetics of the reaction of titanium tetrachloride with the hydride functional groups of diamond. The research was performed on submicron powders of ASM 0.7/0.3 grade synthetic diamond with a specific surface area of 8.0 m/sup 2//g as measured from the adsorption of nitrogen. The reaction was carried out in a flow-through quartz reactor in a flow of dry He. The content of the titanium in the samples was determined by a photocolorimetric method. A kinetic equation for the reaction of diamond with titanium tetrachloride was found on the basis of a statistical approach.

  3. 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.

  4. Numerical investigation on three-dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere.

    Science.gov (United States)

    Jianwen, Zhang; Xinxin, Yin; Yanan, Xin; Jian, Zhang; Xiaoping, Zheng; Chunming, Jiang

    2015-05-15

    The world has experienced heavy thirst of energy as it has to face a dwindling supply of fossil fuel and polycrystalline silicon photovoltaic solar energy technology has been assigned great importance. Silicon tetrachloride is the main byproducts of polysilicon industry, and it's volatile and highly toxic. Once silicon tetrachloride releases, it rapidly forms a dense gas cloud and reacts violently with water vapor in the atmosphere to form a gas cloud consisting of the mixture of silicon tetrachloride, hydrochloric acid and silicic acid, which endangers environment and people. In this article, numerical investigation is endeavored to explore the three dimensional dispersion and conversion behaviors of silicon tetrachloride release in the atmosphere. The k-ϵ model with buoyancy correction on k is applied for turbulence closure and modified EBU model is applied to describe the hydrolysis reaction of silicon tetrachloride. It is illustrated that the release of silicon tetrachloride forms a dense cloud, which sinks onto the ground driven by the gravity and wind and spreads both upwind and downwind. Complicated interaction occurs between the silicon tetrachloride cloud and the air mass. The main body of the dense cloud moves downwind and reacts with the water vapor on the interface between the dense cloud and the air mass to generate a toxic mixture of silicon tetrachloride, hydrogen chloride and silicic acid. A large coverage in space is formed by the toxic mixture and imposes chemical hazards to the environment. The exothermic hydrolysis reaction consumes water and releases reaction heat resulting in dehydration and temperature rise, which imposes further hazards to the ecosystem over the affected space.

  5. The extraction of vanadium pentoxide from waste of titanium tetrachloride by various methods

    Directory of Open Access Journals (Sweden)

    Инна Михайловна Гунько

    2015-04-01

    Full Text Available In article the recovery possibility of vanadium pentoxide from wastes, formed as a result of purification from impurities of technical titanium tetrachloride is researched. The purification from impurities is realized by different methods – pulp of lower titanium chlorides, hydrocarbonic reducer and cascade-rectifying purification. Usage of these purification methods leads to formation of anthropogenic wastes. The researches is shown that processing of these wastes is reasonable for the purpose of vanadium pentoxide extraction

  6. Coagulation performance and floc characteristics of polytitanium tetrachloride (PTC) compared with titanium tetrachloride (TiCl4) and ferric chloride (FeCl3) in algal turbid water

    KAUST Repository

    Chekli, L.

    2016-11-11

    Seasonal green algae blooms in freshwaters have raised attention on the need to develop novel effective treatment processes for the removal of algae in water. In the present study, the performance of newly developed polytitanium tetrachloride (PTC) coagulant for the removal of freshwater microalga Chlorella vulgaris has been investigated and compared with titanium tetrachloride (TiCl4) coagulant and the conventional ferric chloride (FeCl3) coagulant. The main benefit of using titanium-based coagulants is that the sludge produced after flocculation may be recycled into a valuable product: titanium dioxide photocatalyst. Both titanium-based coagulants achieved good flocculation over a broader pH range and coagulant dose compared to conventional FeCl3 coagulant. All three coagulants achieved comparable performance in terms of turbidity removal (i.e. turbidity removal efficiency >97%); although TiCl4 performed slightly better at the lower tested dose (i.e. <9 mg/L). Zeta potential measurements indicated that charge neutralisation may not be the sole mechanism involved in the coagulation of algae for all three coagulants. Analysis of the dynamic floc size variation during floc breakage showed no regrowth after floc breakage for the three coagulants. The flocs formed by both Ti-based coagulants were larger than those formed by FeCl3 and also grew at a faster rate. This study indicates that Ti-based coagulants are effective and promising coagulants for algae removal in water.

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

    Science.gov (United States)

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

    2004-02-01

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

  8. Destruction of carbon tetrachloride in a dielectric barrier/packed-bed corona reactor

    Science.gov (United States)

    Tonkyn, R. G.; Barlow, S. E.; Orlando, T. M.

    1996-11-01

    The destruction of low concentrations (corona reactor was studied. We compare, in particular, the destruction efficiencies using either borosilicate or zirconia oxide (ZrO2) packing materials in dry and moist air, and nitrogen buffer gases. Measurements of contaminant removal in the effluent gas were made at atmospheric pressure as a function of energy dissipated in the reactor. In dry N2, destruction of CCl4 was most efficient using ZrO2 beads, whereas, in dry air, contaminant removal was approximately equal for borosilicate glass and ZrO2. The presence of water in the gas stream reduced the CCl4 destruction efficiency under all conditions. This reduction was likely a synergistic effect that involves changes in the plasma density, scavenging of low energy secondary electrons, and possible surface passivation. Assuming the primary step in CCl4 destruction is dissociative electron attachment, an estimate of the average density of low energy electrons as a function of input energy was made. We relate the enhancement in CCl4 destruction using the ZrO2 beads in N2 to a slight increase in the number density of low energy secondary electrons. A discussion of the importance of energy density measurements and a useful phenomenological kinetic model consistent with the observed results are presented.

  9. 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.

  10. Diethylcarbamazine Reduces Chronic Inflammation and Fibrosis in Carbon Tetrachloride- (CCl4- Induced Liver Injury in Mice

    Directory of Open Access Journals (Sweden)

    Sura Wanessa Santos Rocha

    2014-01-01

    Full Text Available This study investigated the anti-inflammatory effects of DEC on the CCl4-induced hepatotoxicity in C57BL/6 mice. Chronic inflammation was induced by i.p. administration of CCl4 0.5 μL/g of body weight through two injections a week for 6 weeks. DEC (50 mg/kg was administered by gavage for 12 days before finishing the CCl4 induction. Histological analyses of the DEC-treated group exhibited reduced inflammatory process and prevented liver necrosis and fibrosis. Immunohistochemical and immunofluorescence analyses of the DEC-treated group showed reduced COX-2, IL1β, MDA, TGF-β, and αSMA immunopositivity, besides exhibiting decreased IL1β, COX-2, NFκB, IFNγ, and TGFβ expressions in the western blot analysis. The DEC group enhanced significantly the IL-10 expression. The reduction of hepatic injury in the DEC-treated group was confirmed by the COX-2 and iNOS mRNA expression levels. Based on the results of the present study, DEC can be used as a potential anti-inflammatory drug for chronic hepatic inflammation.

  11. Hepatoprotective activity of Eclipta alba against carbon tetrachloride-induced hepatotoxicity in albino rats

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    Ravindra S. Beedimani

    2015-06-01

    Conclusion: The results of the study confirmed the hepatoprotective activity of aqueous extracts of E. alba at doses of 250 mg/kg and 500 mg/kg against CCl4 induced hepatotoxicity in rats. However, the dose adjustments may be necessary to optimize the similar hepatoprotective efficacy in clinical settings. [Int J Basic Clin Pharmacol 2015; 4(3.000: 404-409

  12. HEPATOPROTECTIVE ACTIVITY OF METHANOLIC EXTRACT OF ECBOLIUM VIRIDE (FORSSK. ALSTON ROOTS AGAINST CARBON TETRACHLORIDE INDUCED HEPATOTOXICITY

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    Ashoka Babu V.L

    2012-08-01

    Full Text Available In the present study, the methanolic extract of Ecbolium viride root was evaluated for its hepatoprotective effect against CCl4 induced hepatic injury in rats. Alteration in the levels of biochemical markers of hepatic damage like SGOT, SGPT, ALP, triglycerides, bilirubin, total proteins and liver weight were tested in both treated and untreated groups. CCl4 (1ml/kg enhanced the SGPT, SGOT, ALP, triglycerides, liver weight and reduced total proteins significantly. Treatment with methanolic extract of Ecbolium viride roots (200mg/kg and 400mg/kg has brought back the altered levels of altered levels of biochemical markers significantly to the near normal levels in the dose dependant manner.

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

    Science.gov (United States)

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

    2015-12-01

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

  14. Hepatoprotective activity of Haridradi ghrita on carbon tetrachloride-induced liver damage in rats.

    Science.gov (United States)

    Satturwar, P M; Fulzele, S V; Joshi, S B; Dorle, A K

    2003-12-01

    Haridradi ghrita, a ghee based polyherbal formulation, (50, 100, 200 and 300 mg/kg) significantly lowered marker enzymes (SGPT, SGOT, ALP) and bilirubin in serum and liver peroxide, superoxide dismutase and catalase in liver homogenate following CCl4 (0.7 ml/kg, ip) toxicity. The protective effect was further supported by reversal of CCl4 induced histological changes. The results demonstrate significant hepatoprotective action of H. ghrita in CCl4 damaged rats.

  15. Campomanesia adamantium (Myrtaceae fruits protect HEPG2 cells against carbon tetrachloride-induced toxicity

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    Thaís de Oliveira Fernandes

    2015-01-01

    Full Text Available Campomanesia adamantium (Myrtaceae is an antioxidant compounds-rich Brazilian fruit popularly known as gabiroba. In view of this, it was evaluated the hepatoprotective effects of pulp (GPE or peel/seed (GPSE hydroalcoholic extracts of gabiroba on injured liver-derived HepG2 cells by CCl4 (4 mM. The results showed the presence of total phenolic in GPSE was (60% higher when compared to GPE, associated with interesting antioxidant activity using DPPH·− assay. Additionally, HPLC chromatograms and thin layer chromatography of GPE and GPSE showed the presence of flavonoids. Pretreatment of HepG2 cells with GPE or GPSE (both at 800–1000 μg/mL significantly (p < 0.0001 protected against cytotoxicity induced by CCl4. Additionally, the cells treated with both extracts (both at 1000 μg/mL showed normal morphology (general and nuclear contrasting with apoptotic characteristics in the cells only exposed to CCl4. In these experiments, GPSE also was more effective than GPE. In addition, CCl4 induced a marked increase in AST (p < 0.05 and ALT (p < 0.0001 levels, while GPE or GPSE significantly (p < 0.0001 reduced these levels, reaching values found in the control group. In conclusion, the results suggest that gabiroba fruits exert hepatoprotective effects on HepG2 cells against the CCl4-induced toxicity, probably, at least in part, associated with the presence of antioxidant compounds, especially flavonoids.

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

    Science.gov (United States)

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

    2007-05-22

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

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

    Science.gov (United States)

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

    2014-05-15

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

  18. Zincovit syrup ameliorates oxidative stress induced by carbon tetrachloride in rats

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    S. M. Satyam

    2015-06-01

    Conclusion: The present findings revealed that ZVT syrup may be useful in oxidative stress associated tissue damage as a nutritional food supplement. [Int J Basic Clin Pharmacol 2015; 4(3.000: 449-452

  19. Atmospheric lifetime experiment. 6. Results for carbon tetrachloride based on 3 years data

    Energy Technology Data Exchange (ETDEWEB)

    Simmonds, P.G.; Alyea, F.N.; Cardelino, C.A.; Cunnold, D.M.; Crawford, A.J.; Rasmussen, R.A.; Lane, B.C.; Lovelock, J.E.; Prinn, R.G.

    1983-10-20

    The automated electron capture gas chromatographic determination of the atmospheric concentrations of CCl/sub 4/ are reported for the period July 1978 to June 1981 at five coastal monitoring stations. Adrigole (Ireland), Cape Meares (Oregon). Ragged Point (Barbados, West Indies), Point Matatula (American Samoa), and Cape Grim (Tasmania). Daily measurements at approximately 6-hourly intervals are always complimented by an equivalent number of on-site calibration measurements. Estimates of CCl/sub 4/ emissions to the atmosphere from known industrial sources are compared with the measured trends and the absolute values of the observed concentrations. A globally averaged atmospheric lifetime for CCl/sub 4/ is calculated by using an optimal estimation technique incorporating a nine-box model of the atmosphere. The average global concentration of CCl/sub 4/ from July 1978 to June 1981 in the lower troposphere was 118 pptv, and it was increasing 2.1 pptv/year over this period. Both the absolute concentration observed and its trend are consistent with the calculated releases of CCl/sub 4/ and its expected destruction by stratospheric photolysis.

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

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

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    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.

  2. 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.

  3. Carbon Tetrachloride Increases Intracellular Calcium in Rat Liver and Hepatocyte Cultures

    Science.gov (United States)

    1986-05-12

    Lehninger ~~., 1967). Although mitochondria provide a relatively high capacity Ca++ sink, the affinity of this pump for Ca ++ is much less that of the Ca... Lehninger , A. L., E. Carafoli, and c. s. Rossi. (1967) Energy-Linked Ion Movements in Mitochondrial Systems. Adv. Enzymology 29:259-320. Lowry, O. H

  4. Studies on the mechanism of enhancement of carbon tetrachloride hepatotoxicity by Triton WR 1339.

    OpenAIRE

    de Ferreyra, E. C.; de Toranzo, E. G.; de Fenos, O. M.; Castro, J A

    1981-01-01

    Pretreatment of rats with Triton WR 1339 significantly enhanced the intensity of CC14-induced liver necrosis. Previous workers suggested that this effect might be due to enhancement by Triton WR 1339 of cellular degradative processes. This pretreatment, however, also enhanced the intensity of covalent binding of [14C]CC14 metabolites to microsomal protein at 3 or 6 h, but not 1 h after its administration. This effect is not due to changes of microsomal P-450 content or increased activity of m...

  5. Protective effects of Coriandrum sativum extracts on carbon tetrachloride-induced hepatotoxicity in rats.

    Science.gov (United States)

    Sreelatha, S; Padma, P R; Umadevi, M

    2009-04-01

    Oxidative damage is implicated in the pathogenesis of various liver injuries. The study was aimed to investigate the antioxidant activity of Coriandrum sativum on CCl(4) treated oxidative stress in Wistar albino rats. CCl(4) injection induced oxidative stress by a significant rise in serum marker enzymes and thiobarbituric acid reactive substances (TBARS) along with the reduction of antioxidant enzymes. In serum, the activities of enzymes like ALP, ACP and protein and bilirubin were evaluated. Pretreatment of rats with different doses of plant extract (100 and 200mg/kg) significantly lowered SGOT, SGPT and TBARS levels against CCl(4) treated rats. Hepatic enzymes like SOD, CAT, GPx were significantly increased by treatment with plant extract, against CCl(4) treated rats. Histopathological examinations showed extensive liver injuries, characterized by extensive hepatocellular degeneration/necrosis, inflammatory cell infiltration, congestion, and sinusoidal dilatation. Oral administration of the leaf extract at a dose of 200mg/kg body weight significantly reduced the toxic effects of CCl(4). The activity of leaf extract at the dose of 200mg/kg was comparable to the standard drug, silymarin. Based on these results, it was observed that C. sativum extract protects liver from oxidative stress induced by CCl(4) and thus helps in evaluation of traditional claim on this plant.

  6. Synergistic neurotoxicity of carbon tetrachloride/carbon disulfide (80/20 fumigants) and other pesticides in grain storage workers.

    Science.gov (United States)

    Peters, H A; Levine, R L; Matthews, C G; Sauter, S; Chapman, L

    1986-01-01

    Neurophysiologic, neurobehavioral, and neuropsychologic profiles in 17 grain storage workers, 1 grain inspector, and 4 malting laboratory workers are described. The effects of CS2 toxicity as seen in viscose rayon workers as well as in experimental animals is remarkably similar to the clinical profile of our grain storage workers. CS2 use explains the dysfunction of peripheral axons, auditory nerve, the optic nerve, and the extrapyramidal system, as well as altered behavior and cognition changes. The signs and symptoms in these workers seem to be dose-related and we note that workers separated out from the areas where fumigation took place reported improvement not seen by fellow workers who continued the fumigant treatment routine. Likewise, malting laboratory workers exposed only to the grain dust from 3 to 7 years showed only minimal symptoms. Though a number of mechanism have been suggested for the alteration of neuropsychological function, the chelating ability of DDC derived from CS2 and its ability to markedly increase copper and zinc within the central nervous system suggests a mechanism of toxicity analogous to copper intoxication as in Wilson's Disease and may explain the production of extrapyramidal symptoms in these patients. Chelation of copper might prove therapeutic in CS2 poisoning. It is obvious that both basic and clinical research will be necessary to sort out the questions raised. We applaud the EPA's decision to ban the use of 80/20 fumigants and also methyl bromide, and trust that similar toxic substances be carefully studied before their selection for replacing these previous toxic agents. We further decry the technique of re-introducing grain dust into the food chain rather than destroying it, since the dust contains very high residues of fumigant material. We speculate on the possible role of CS2 and other pesticides in the food chain and the incidence of Parkinsonian symptoms in these patients and the general public.

  7. Titanium tetrachloride for silver nanoparticle-humic acid composite contaminant removal in coagulation-ultrafiltration hybrid process: floc property and membrane fouling.

    Science.gov (United States)

    Zhao, Yanxia; Sun, Yangyang; Tian, Chang; Gao, Baoyu; Wang, Yan; Shon, Hokyong; Yang, Yanzhao

    2017-01-01

    Titanium-based coagulation is expected to achieve both efficient water purification and sludge recycling. This study is the first attempt to use titanium tetrachloride (TiCl4) for silver nanoparticle (AgNP)-humic acid composite contaminant removal in a coagulation-ultrafiltration (C-UF) process, where characterization of flocs and membrane fouling under varied coagulant dose, initial solution pH, and AgNP concentration conditions are the main contents. Results suggested that the TiCl4 achieved high AgNP removal in the form of silver nanoparticle through adsorption and sweep flocculation and simultaneously exerted additional 68.2 % higher dissolved organic carbon removal than Al2(SO4)3. The TiCl4 produced larger and stronger flocs but with weaker recoverability and less compact degree than did Al2(SO4)3. Floc properties were independent of AgNP concentration except floc fractal dimension, which was negatively correlated with AgNP concentration. The TiCl4 precoagulation caused less membrane fouling within wider pH range than Al2(SO4)3 did in the C-UF process. Incorporation of AgNPs during the TiCl4 pretreatment process facilitated the mitigation of membrane fouling, which was, however, negligibly influenced by AgNP concentration in the case of Al2(SO4)3.

  8. Synthesis of some new bis-3,4-dihydropyrimidin-2(1H)-ones by using silica-supported tin chloride and titanium tetrachloride

    Institute of Scientific and Technical Information of China (English)

    Khodabakhsh; Niknam; Alireza; Hasaninejad; Madihe; Arman

    2010-01-01

    Silica-supported tin chloride and titanium tetrachloride were prepared by the reaction of tin chloride and titanium tetrachloride with activated silica gel in refluxing toluene.These solid acids have been employed as the catalysts for the synthesis of bisdihydropyrimidin -2(1H)-ones from aromatic dialdehydes,1,3-dicarbonyl compounds and urea at 90℃under solvent-free conditions.

  9. Effect of aluminum and tellurium tetrachloride addition on the loss of arsenic selenide optical fiber

    Science.gov (United States)

    Nguyen, Vinh Q.; Drake, Gryphon; Villalobos, Guillermo; Gibson, Daniel; Bayya, Shyam; Kim, Woohong; Baker, Colin; Chin, Geoff; Kung, Frederic H.; Kotov, Mikhail I.; Busse, Lynda; Sanghera, Jasbinder S.

    2017-02-01

    Arsenic selenide glass optical fibers typically possess extrinsic absorption bands in the infrared wavelength regions associated with residual hydrogen and oxygen related impurities, despite using 6N purified elemental precursors. Consequently, special additives and refined processing steps are utilized in an attempt to reduce these and other impurities. We investigate the formation of particulate impurities during a purification process based on the addition of 0.1 wt% elemental aluminum (Al) and 0.2 wt% tellurium tetrachloride (TeCl4) during glass synthesis. It was found that during purification and melting steps, Al reacts with TeCl4 to form AlCl3, which in turn reacts with oxygen and hydrogen impurities and the fused quartz (SiO2) ampoule to produce HCl and stable submicron Al2SiO5 compounds in the As-Se glass and fibers. The intensity of the H-Se absorption band centered at 4.57 μm has been significantly reduced from 18 dB/m to 0.8 dB/m. Using thermodynamic data, we have identified stable Al2SiO5 submicron inclusions in the glass and fibers. A two-step gettering process is proposed as a solution to eliminating these inclusions.

  10. Mechanism of Enhanced Performance of Dye-Sensitized Solar Cell Based TiO2 Films Treated by Titanium Tetrachloride

    Institute of Scientific and Technical Information of China (English)

    曾隆月; 戴松元; 王孔嘉; 潘旭; 史成武; 郭力

    2004-01-01

    Performance of dye-sensitized solar cells can be improved by treating the nanoporous TiO2 films with titanium tetrachloride (TiCl4) aqueous solution. We explore the reason why the performance of dye-sensitized solar cells is enhanced by this method. It is found that the effect of TiCl4 treatment not only reduces the films surface area and improves the electronic contact, but also enhances the binding of N719 with the TiO2 films surface.

  11. Modeling of Carbon Tetrachloride Flow and Transport in the Subsurface of the 200 West Disposal Sites: Large-Scale Model Configuration and Prediction of Future Carbon Tetrachloride Distribution Beneath the 216-Z-9 Disposal Site

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Mart; Thorne, Paul D.; Zhang, Z. F.; Last, George V.; Truex, Michael J.

    2008-12-17

    Three-dimensional simulations considered migration of dense, nonaqueous phase liquid (DNAPL) consisting of CT and co disposed organics in the subsurface as a function of the properties and distribution of subsurface sediments and of the properties and disposal history of the waste. Simulations of CT migration were conducted using the Water-Oil-Air mode of Subsurface Transport Over Multiple Phases (STOMP) simulator. A large-scale model was configured to model CT and waste water discharge from the major CT and waste-water disposal sites.

  12. Protective effects of melatonin against carbon tetrachloride-induced hepatotoxicity in rats: a light microscopic and biochemical study.

    Science.gov (United States)

    Kus, Ilter; Ogeturk, Murat; Oner, Hakan; Sahin, Semsettin; Yekeler, Hayrettin; Sarsilmaz, Mustafa

    2005-01-01

    The aim of this study was to examine the protective effects of melatonin against CCl4-induced hepatotoxicity in the rat. Twenty-four male Wistar rats were divided into three groups. Group I was used as a control. Rats in group II were injected every other day with CCl4 for 1 month, whereas rats in group III were injected every other day with CCl4 and melatonin for 1 month. At the end of the experiment, all animals were killed by decapitation and blood samples were obtained. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total and conjugated bilirubin levels were determined. For histopathological evaluation, livers of all rats were removed and processed for light microscopy. All serum biochemical parameters were significantly higher in animals treated with CCl4 than in the controls. When rats injected with CCl4 were treated with melatonin, significantly reduced elevations in serum biochemical parameters were found. In liver sections of the CCl4-injected group, necrosis, fibrosis, mononuclear cell infiltration, haemorrhage, fatty degeneration and formation of regenerative nodules were observed. Additionally, apoptotic figures, microvesicular steatosis and hydropic degeneration in hepatocytes were seen in this group. In contrast, the histopathological changes observed after administration of CCl4 were lost from rats treated with CCl4 and melatonin. Except for mild hydropic degeneration of the hepatocytes, a normal lobular appearance was seen in the livers of this group. The results of our study indicate that melatonin treatment prevents CCl4-induced liver damage in rats.

  13. 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.

  14. [Evaluation of the action of a fat diet on the state of the liver poisoned by carbon tetrachloride].

    Science.gov (United States)

    Sadykh-zade, K S; Volgarev, M N; Piatnitskiĭ, N N; Zhminchenko, V M; Mal'tsev, G Iu

    1981-01-01

    The effects of the diet containing different amounts of fat on the liver with CCl4 poisoning were studied in two series of experiments on 150 male Wistar rats. In the first series th priming was given in the presence of the laboratory diet for 1 1/2 months. In the second series, the 1 1/2-month priming was given in the presence of the diets tested. The control animals given no priming were kept on the laboratory diet in which the fat (sunflower oil) amount constituted 23% as regards the caloricity. The experimental animals were distributed into 2 groups kept on the diets containing 27 and 43% of fat as regards the caloricity (creamery butter and sunflower oil at a ratio of 2 : 1). All three diets were isocaloric, having the identical content of protein. Change in the fat amount was compensated for the respective change in the carbohydrate content. It was found that application of the diet with the increased content of milk and vegetable fat (43% as regards the caloricity) led to a marked improvement of the liver, while early application of the test diets in the presence of CCl4 brought about a significant decrease in the lethality of the experimental animals.

  15. 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

    2014-09-02

    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.

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

    Science.gov (United States)

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

    2016-01-06

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

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

    Directory of Open Access Journals (Sweden)

    Krutika T. Deshpande

    2016-01-01

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

  18. Session 6: Hydro-dechlorination of Carbon Tetrachloride: Study of the Deactivation and Regeneration of Pt Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Garetto, T.F.; Borgna, A. [Instituto de Investigaciones en Catalisis y Petroquimica-INCAPE. (UNL-CONICET), Santa Fe (Argentina); Montoya, J.A.; Acosta, D. [Zaragoza Univ., Dept. de Ingenieria Quimica y Tecnologias del Medio Ambiente. Facultad de Ciencias (Spain); Monzon, A. [Instituto Mexicano del Petroleo, D.F. (Mexico)

    2004-07-01

    The aim of this work is to get more insight on the deactivation-regeneration process of supported metal catalysts during CTC hydro-dechlorination. In this contribution we report a kinetic analysis on the deactivation-regeneration of Pt/Al{sub 2}O{sub 3} catalysts and the effect of the regeneration conditions. Particularly, the effectiveness of the regeneration treatment under different atmospheres is analyzed. (authors)

  19. TRANSFORMATION OF CARBON TETRACHLORIDE BY REDUCED VITAMIN B12 IN AQUEOUS CYSTEINE SOLUTION. (R825689C073)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  20. Treatability Test Report: Characterization of Vadose Zone Carbon Tetrachloride Source Strength Using Tomographic Methods at the 216-Z-9 Site

    Energy Technology Data Exchange (ETDEWEB)

    Truex, Michael J.; Carroll, Kenneth C.; Rohay, Virginia J.; Mackley, Rob D.; Parker, Kyle R.

    2012-09-28

    A treatability test was conducted in 2011 at the 216-Z-9 Trench to evaluate methods for collecting characterization information that supports refined assessment of SVE performance goals based on impact to groundwater. The characterization information can also provide input to operational strategies for continued SVE operation and decisions regarding closure of the SVE system or transition to other remedies, if necessary.

  1. Possible mechanism of adenosine protection in carbon tetrachloride acute hepatotoxicity. Role of adenosine by-products and glutathione peroxidase.

    Science.gov (United States)

    Chagoya de Sánchez, V; Hernández-Muñoz, R; Yáñez, L; Vidrio, S; Díaz-Muñoz, M

    1995-02-01

    Adenosine proved to be an effective hepatoprotector increasing the survival rate of rats receiving lethal doses of CCl4. Searching for the mechanism of action, we found that adenosine transiently prevents the necrotic liver damage associated to an acute CCl4 treatment. The antilipoperoxidative action of the nucleoside was evidenced by a decrease of TBA-reactive products and the diene conjugates elicited by the hepatotoxin. Adenosine's protective effect was demonstrated by reverting the decrease of cytochrome P-450 while preserved intact the activity of the microsomal enzyme glucose-6-phosphatase. CCl4 promoted an increase in the oxidant stress through an enhancement in oxidized glutathione levels. This action was also completely counteracted by the nucleoside. Adenosine was unable to prevent CCl4 activation and, even, increased .CCl3 formation in the presence of PBN in vivo. However, in the presence of the nucleoside, irreversible binding of 14CCl4 to the microsomal lipid fraction of the treated animals was decreased. These results suggest that adenosine protective action might be exerted at the level of the propagation reaction following CCl4 activation. Two possible mechanisms were associated to the nucleoside protection: (1) the peroxide-metabolyzed enzymes, GSH-per, showed a marked increase after 30 minutes of adenosine treatment, which was potentiated by the hepatotoxin, suggesting an important role of this enzyme in the nucleoside's action; (2) the adenosine catabolism induced an increase in uric acid level, and allopurinol, a purine metabolism inhibitor, prevented such elevation as well as the antilipoperoxidative action of adenosine and the increase of GSH-per associated with the nucleoside treatment. These facts strongly suggest that the protective effect elicited by adenosine is not a direct one, but rather is related to its catabolic products, such as uric acid, which has been recognized as a free radical scavenger.

  2. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Henry, E.C.

    1979-01-01

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

  5. Protective role of Cupressuflavone from Cupressus macrocarpa against carbon tetrachloride-induced hepato- and nephrotoxicity in mice.

    Science.gov (United States)

    Al-Sayed, Eman; Abdel-Daim, Mohamed M

    2014-12-01

    The hepatoprotective and nephroprotective activity of cupressuflavone isolated from Cupressus macrocarpa was investigated against CCl4-induced toxicity in mice. Cupressuflavone was administered (40, 80, and 160 mg/kg/day) for five days. CCl4 was administered (0.5 mL/kg intraperitoneally) at the end of the experiment. A substantial increase (p < 0.001) in the levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, total bilirubin, cholesterol, creatinine, uric acid, urea, and malondialdehyde was observed in the CCl4-treated group compared to the normal control group. In contrast, a significant reduction (p < 0.001) in glutathione and superoxide dismutase contents as well as the total protein level was evident in the CCl4-intoxicated mice. Cupressuflavone pretreatment markedly inhibited the CCl4-induced increase in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, cholesterol, creatinine, uric acid, urea, and malondialdehyde levels in a dose-dependent manner (p < 0.001 at all the tested doses). In addition, a significant (p < 0.001) and dose-dependent decrease in the total bilirubin levels was evident by cupressuflavone pretreatment (80 and 160 mg/kg/day) when compared to the CCl4-intoxicated group. Furthermore, cupressuflavone administration significantly increased the activity of antioxidant parameters glutathione and superoxide dismutase as well as the serum protein levels (p < 0.001 at all the tested doses) in a dose-dependent manner. Histological observations confirmed the strong hepato- and nephroprotective activity. These findings suggest that cupressuflavone could exert a beneficial effect against oxidative stress by enhancing the antioxidant defense status, reducing lipid peroxidation, and protecting against the pathological changes induced by CCl4 in the liver and kidney tissues. The structure of cupressuflavone was identified by NMR, UV, and HRESI-MS/MS spectral data.

  6. Synthesis of novel E-2-chlorovinyltellurium compounds based on the stereospecific anti-addition of tellurium tetrachloride to acetylene.

    Science.gov (United States)

    Musalova, Maria V; Potapov, Vladimir A; Amosova, Svetlana V

    2012-05-15

    The reaction of tellurium tetrachloride with acetylene proceeds in a stereospecific anti-addition manner to afford the novel products E-2-chlorovinyltellurium trichloride and E,E-bis(2-chlorovinyl)tellurium dichloride. Reaction conditions for the selective preparation of each of these products were found. The latter was obtained in 90% yield in CHCl(3) under a pressure of acetylene of 10-15 atm, whereas the former product was formed in up to 72% yield in CCl(4) under a pressure of acetylene of 1-3 atm. Synthesis of the previously unknown E,E-bis(2-chlorovinyl) telluride, E,E-bis(2-chlorovinyl) ditelluride, E-2-chlorovinyl 1,2,2-trichloroethyl telluride and E,E-bis(2-chlorovinyl)-tellurium dibromide is described.

  7. Transformation of Oximes and Alcohols to Carbonyl Compounds Using Amberlite IRA-400 Supported Chromic Acid in the Presence of Zirconium Tetrachloride

    Institute of Scientific and Technical Information of China (English)

    BAHRAMI, Kiumars; KHODAEIMohammad-Mehdi; GORGIN-KARAJI, Usef

    2009-01-01

    A wide variety of oximes and alcohols were efficiently converted to their corresponding aldehydes and ketones in good to excellent yields using amberlite IRA-400 supported chromic acid in the presence of zirconium tetrachlo-ride in refluxing acetonitrile-H2O. Selective oxidation of oximes and alcohols in the presence of other functional groups such as acetal, hydrazone, aldehyde, ether and alkene can be considered as a noteworthy advantage of this method. A wide variety of oximes and alcohols were efficiently converted to their corresponding aldehydes and ke-tones in good to excellent yields using amberlite IRA-400 supported chromic acid in the presence of zirconium tet-rachloride in refluxing acetonitrile-H2O. Selective oxidation of oximes and alcohols in the presence of other func-tional groups such as acetal, hydrazone, aldehyde, ether and alkene can be considered as a noteworthy advantage of this method.

  8. [Reaction of 3-aryl-2-nitroacrylates with titanium tetrachloride. Formation of 4H-1,2-oxazines and hydroxy-arylaldehydes].

    Science.gov (United States)

    Hirotani, S; Zen, S

    1994-04-01

    The reaction of ethyl 3-aryl-2-nitroacrylate (1a: aryl = 3-methoxyphenyl) with toluene in the presence of titanium tetrachloride gave 4-(4'-methyl-phenyl)-4H-1,2-benzoxazine (3) in a 44.2% yield. The acrylate 1a reacted with dichloromethane in the presence of titanium tetrachloride to give 5-methoxy-salicylaldehyde (2a) in a 61.8% yield. Therefore, 2a was presumed to be formed via an intermediate 4H-1,2-benzoxazine (3'), followed by ring opening to quinone methide and cyano formate. In a similar reaction using both toluene and dichloromethane, 1 bearing a 2-naphthyl group gave a dimer of quinone methide and 1-hydroxy-2-naphthaldehyde via 4H-naphth[2,1-e]-1,2-oxazine, respectively.

  9. Removal of natural organic matter by titanium tetrachloride: The effect of total hardness and ionic strength.

    Science.gov (United States)

    Zhao, Y X; Shon, H K; Phuntsho, S; Gao, B Y

    2014-02-15

    This study is the first attempt to investigate the effect of total hardness and ionic strength on coagulation performance and the floc characteristics of titanium tetrachloride (TiCl4). Membrane fouling under different total hardness and ionic strength conditions was also evaluated during a coagulation-ultrafiltration (C-UF) hybrid process. Coagulation experiments were performed with two simulated waters, using humic acid (HA, high molecular weight) and fulvic acid (FA, relatively low molecular weight), respectively, as model natural organic matter (NOM). Results show that both particle and organic matter removal can be enhanced by increasing total hardness and ionic strength. Floc characteristics were significantly influenced by total hardness and ionic strength and were improved in terms of floc size, growth rate, strength, recoverability and compactness. The results of the UF tests show that the pre-coagulation with TiCl4 significantly improves the membrane permeate fluxes. Under different total hardness and ionic strength conditions, the membrane permeate flux varied according to both NOM and floc characteristics. The increase in total hardness and ionic strength improved the membrane permeate flux in the case of HA simulated water treatment.

  10. Silicon nanocrystal production through non-thermal plasma synthesis: a comparative study between silicon tetrachloride and silane precursors

    Science.gov (United States)

    Yasar-Inceoglu, Ozgul; Lopez, Thomas; Farshihagro, Ebrahim; Mangolini, Lorenzo

    2012-06-01

    Silicon nanocrystals with sizes between 5 and 10 nm have been produced in a non-thermal plasma reactor using silicon tetrachloride as precursor. We demonstrate that high-quality material can be produced with this method and that production rates as high as 140 mg h-1 can be obtained, with a maximum precursor utilization rate of roughly 50%. Compared to the case in which particles are produced using silane as the main precursor, the gas composition needs to be modified and hydrogen needs to be added to the mixture to enable the nucleation and growth of the powder. The presence of chlorine in the system leads to the production of nanoparticles with a chlorine terminated surface which is significantly less robust against oxidation in air compared to the case of a hydrogen terminated surface. We also observe that significantly higher power input is needed to guarantee the formation of crystalline particles, which is a consequence not only of the different gas-phase composition, but also of the influence of chlorine on the stability of the crystalline structure.

  11. Visible and near-infrared excitation spectra from the neptunyl ion doped into a uranyl tetrachloride lattice

    Science.gov (United States)

    Barker, Beau J.; Berg, John M.; Kozimor, Stosh A.; Wozniak, Nicholas R.; Wilkerson, Marianne P.

    2016-03-01

    Visible and near-infrared illumination induces 5f-5f and ligand-to-metal charge-transfer (LMCT) transitions of the neptunyl tetrachloride anion in polycrystalline Cs2U(Np)O2Cl4, and results in near-infrared luminescence from the second electronically excited state to the ground state. This photoluminescence is used as a detection method to collect excitation spectra throughout the near-infrared and visible regions. The excitation spectra of LMCT transitions in excitation spectra were identified in previous work. Here the measurement and analysis is extended to include both LMCT and intra-5f transitions. The results manifest variation in structural properties of the neptunium-oxo bond among the low-lying electronic states. Vibronic intensity patterns and energy spacings are used to compare bond lengths and vibrational frequencies in the excited states, confirming significant characteristic differences between those excited by 5f-5f transitions from those due to LMCT transitions. Results are compared with recently published RASPT2/SO calculations of [NpO2Cl4]2-.

  12. Synthesis, growth, and structural, optical, mechanical, electrical properties of a new inorganic nonlinear optical crystal: Sodium manganese tetrachloride (SMTC

    Directory of Open Access Journals (Sweden)

    M. Packiya raj

    2017-01-01

    Full Text Available A new inorganic nonlinear optical single crystal of sodium manganese tetrachloride (SMTC has been successfully grown from aqueous solution using the slow evaporation technique at room temperature. The crystals obtained using the aforementioned method were characterized using different techniques. The crystalline nature of the as-grown crystal of SMTC was analyzed using powder X-ray diffraction. Single-crystal X-ray diffraction revealed that the crystal belongs to an orthorhombic system with non-centrosymmetric space group Pbam. The optical transmission study of the SMTC crystal revealed high transmittance in the entire UV–vis region, and the lower cut-off wavelength was determined to be 240 nm. The mechanical strength of the as-grown crystal was estimated using the Vickers microhardness test. The second harmonic generation (SHG efficiency of the crystal was measured using Kurtz's powder technique, which indicated that the crystal has a nonlinear optical (NLO efficiency that is 1.32 times greater than that of KDP. The dielectric constant and dielectric loss of the compound were measured at different temperatures with varying frequencies. The photoconductivity study confirmed that the title compound possesses a negative photoconducting nature. The growth mechanism and surface features of the as-grown crystals were investigated using chemical etching analysis.

  13. Synthesis and physicochemical characterization of titanium oxide and sulfated titanium oxide obtained by thermal hydrolysis of titanium tetrachloride

    Directory of Open Access Journals (Sweden)

    H. Esteban Benito

    2014-09-01

    Full Text Available This work reports the synthesis of titanium oxide (TiO2 and sulfated titanium oxide (TiO2-SO4(2- obtained by thermal hydrolysis of titanium tetrachloride. Titanium hydroxide synthesized by this method was impregnated with a 1 N H2SO4 solution, to give amounts of sulfate ions (SO4(2- of 3 and 7 wt%. The synthesized samples were dried at 120 °C during 24 h and then calcined for 3 h at 400 °C. Thermal analyses, X-ray diffraction, nitrogen physisorption, infrared spectroscopy, potentiometric titration with n-butylamine, U.V.-visible diffuse reflectance spectroscopy and scanning electron microscopy were used to characterize the materials. The results of physicochemical characterization revealed that a mixture of crystalline structures, anatase, brookite and rutile developed in the titanium oxide, stabilizing the anatase structure in the sulfated titanium oxides, and coexisting with a small amount of brookite structure. The synthesized mesoporous materials developed specific surface areas between 62 and 70 m² g-1, without detecting an important influence of sulfation on this parameter. The presence of sulfate ions improved the acidity of titanium oxide and modified the characteristics of light absorption in the 425-600 nm region, which suggests the possibility of using these materials in reactions assisted by visible light.

  14. Crystal structure and chemotherapeutic efficacy of the novel compound, gallium tetrachloride betaine, against breast cancer using nanotechnology.

    Science.gov (United States)

    Salem, Ahmed; Noaman, Eman; Kandil, Eman; Badawi, Abdelfattah; Mostafa, Nihal

    2016-08-01

    The objective of this study was to investigate the antitumor efficacy of a novel synthesized compound, betaine gallium-tetrachloride (BTG), alone or combined with ZnO-nanoparticles (BTG + ZnO-NPs) on the incidence of 7, 12-dimethylbenz-anthrathene-induced mammary tumor in female rats. Crystal and molecular structure of the prepared BTG were identified using X-ray crystallography. In vitro study revealed BTG more cytotoxic than BTG + ZnO-NPs on human breast cancer (MCF-7) cell line. In vivo study demonstrated that the blood antioxidant status of tumor-bearing rats (DMBA group) was significantly lower than normal noticeable by a significant decrease in GSH content, GPx, SOD, and CAT activities associated with a significantly high MDA content. Both treatments have significantly elevated SOD and CAT activities with a concomitant decrease of MDA level compared to DMBA group. However, BTG + ZnO-NPs accentuated the decrease of GSH regarding DMBA group. The results showed also that both treatments significantly activate caspase-3 enzyme and apoptosis in mammary glands. Their administration to tumor-bearing rats was found to significantly reduce plasma iron and iron-binding capacity (TIBC) compared to DMBA group. Regarding liver function, both treatments significantly reduced the increase of ALT and AST activities compared to DMBA group. However, BTG + ZnO-NPs decreased albumin below normal level. Histopathological studies showed that normalization of tissue structures was higher in BTG than BTG + ZnO-NPs treatment. According to the results obtained, it is observed that the antitumor effect of BTG alone was as strong as BTG + ZnO-NPs and even more efficient in some aspects accordingly, a combination is not needed. Thus, the novel synthetic gallium derivatives may potentially present a new hope for the development of breast cancer therapeutics, which should attract further scientific and pharmaceutical interest.

  15. Solution phase synthesis of aluminum-doped silicon nanoparticles via room-temperature, solvent based chemical reduction of silicon tetrachloride

    Science.gov (United States)

    Mowbray, Andrew James

    We present a method of wet chemical synthesis of aluminum-doped silicon nanoparticles (Al-doped Si NPs), encompassing the solution-phase co-reduction of silicon tetrachloride (SiCl4) and aluminum chloride (AlCl 3) by sodium naphthalide (Na[NAP]) in 1,2-dimethoxyethane (DME). The development of this method was inspired by the work of Baldwin et al. at the University of California, Davis, and was adapted for our research through some noteworthy procedural modifications. Centrifugation and solvent-based extraction techniques were used throughout various stages of the synthesis procedure to achieve efficient and well-controlled separation of the Si NP product from the reaction media. In addition, the development of a non-aqueous, formamide-based wash solution facilitated simultaneous removal of the NaCl byproduct and Si NP surface passivation via attachment of 1-octanol to the particle surface. As synthesized, the Si NPs were typically 3-15 nm in diameter, and were mainly amorphous, as opposed to crystalline, as concluded from SAED and XRD diffraction pattern analysis. Aluminum doping at various concentrations was accomplished via the inclusion of aluminum chloride (AlCl3); which was in small quantities dissolved into the synthesis solution to be reduced alongside the SiCl4 precursor. The introduction of Al into the chemically-reduced Si NP precipitate was not found to adversely affect the formation of the Si NPs, but was found to influence aspects such as particle stability and dispersibility throughout various stages of the procedure. Analytical techniques including transmission electron microscopy (TEM), FTIR spectroscopy, and ICP-optical emission spectroscopy were used to comprehensively characterize the product NPs. These methods confirm both the presence of Al and surface-bound 1-octanol in the newly formed Si NPs.

  16. Atomic layer deposition of zirconium dioxide from zirconium tetrachloride and ozone

    Energy Technology Data Exchange (ETDEWEB)

    Kukli, Kaupo, E-mail: kaupo.kukli@helsinki.fi [Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); Kemell, Marianna; Köykkä, Joel [Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland); Mizohata, Kenichiro [Accelerator Laboratory, Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 Helsinki (Finland); Vehkamäki, Marko; Ritala, Mikko; Leskelä, Markku [Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki (Finland)

    2015-08-31

    ZrO{sub 2} films were grown by atomic layer deposition using ZrCl{sub 4} and O{sub 3} as precursors. The films were grown on silicon substrates in the temperature range of 220–500 °C. The ALD rate was monotonously decreasing from 0.085 to 0.060 nm/cycle in this temperature range towards the highest temperatures studied. The content of chlorine in the films did not exceed 0.2 at.% as measured by elastic recoil detection analysis. The content of hydrogen was 0.30 and 0.14 at.% in the films grown at 300 and 400 °C, respectively. Structural studies revealed the films consisting of mixtures of stable monoclinic and metastable tetragonal/cubic polymorphs of ZrO{sub 2}, and dominantly metastable phases of ZrO{sub 2} below and above 300 °C, respectively. Permittivity of dielectric layers in Al/Ti/ZrO{sub 2}/(TiN/)Si capacitors with 15–40 nm thick ZrO{sub 2} ranged between 12 and 25 at 100 kHz and the dielectric breakdown fields were in the range of 1.5–3.0 MV/cm. - Highlights: • ZrO{sub 2} thin films were grown by atomic layer deposition from ZrCl{sub 4} and O{sub 3}. • Relatively high substrate temperatures promoted growth of metastable ZrO{sub 2} phases. • ZrO{sub 2} films exhibited electric properties characteristic of dielectric metal oxides. • ZrO{sub 2} grown in hydrogen- and carbon free process contained low amounts of impurities.

  17. Synthesis of zirconium by zirconium tetrachloride reduction by magnesio-thermia. Experimental study and modelling; Elaboration de zirconium par reduction de tetrachlorure de zirconium par magnesothermie. Etude experimentale et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Basin, N

    2001-01-01

    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): ZrCl{sub 4} + 2 Mg = 2 MgCl{sub 2}. 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.)

  18. Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

    Directory of Open Access Journals (Sweden)

    Le Quang Minh

    2015-09-01

    Full Text Available Nuclear power with strengthened safety regulations continues to be used as an important resource in the world for managing atmospheric greenhouse gases and associated climate change. This study examined the environmentally benign separation of zirconium tetrachloride (ZrCl4 and hafnium tetrachloride (HfCl4 for nuclear power reactor applications through extractive distillation using a NaCl-KCl molten salt mixture. The vapor–liquid equilibrium behavior of ZrCl4 and HfCl4 over the molten salt system was correlated with Raoult’s law. The molten salt-based extractive distillation column was designed optimally using a rigorous commercial simulator for the feasible separation of ZrCl4 and HfCl4. The molten salt-based extractive distillation approach has many potential advantages for the commercial separation of ZrCl4 and HfCl4 compared to the conventional distillation because of its milder temperatures and pressure conditions, smaller number of required separation trays in the column, and lower energy requirement for separation, while still taking the advantage of environmentally benign feature by distillation. A heat-pump-assisted configuration was also explored to improve the energy efficiency of the extractive distillation process. The proposed enhanced configuration reduced the energy requirement drastically. Extractive distillation can be a promising option competing with the existing extraction-based separation process for zirconium purification for nuclear power reactor applications.

  19. Development of the method of obtaining donor-acceptor complexes of titanium tetrachloride as a precursor of oxide materials based on titanium oxide and silicon matrix for the catalytically active nanoparticles of platinum group metals

    Directory of Open Access Journals (Sweden)

    A. M. Nemeryuk

    2015-12-01

    Full Text Available The method of preparation of the complex of titanium tetrachloride with dimethylformamide and reactivity when reacted with an alcohol and salts of hydrazine described. Obtained multinuclear complexes containing titanium and palladium as potential precursors of catalytically active materials.

  20. Adsorption of polar probe molecules on plasma-oxidised high-strength carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Montes-Moran, M.A.; Martinez-Alonso, A.; Tascon, J.M.D. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080, Oviedo (Spain)

    2002-06-20

    The objective of this work was to examine the effect of oxygen plasma treatment on the surface chemistry of carbon fibres. Virgin, unsized high-strength carbon fibres were subjected to oxygen plasma treatments with different degrees of severity. Adsorption of probe molecules with different acid-base characteristics (acetone, carbon tetrachloride, trichloromethane, dichloromethane, diethyl ether, nitromethane, tetrahydrofurane) was measured at 303-353 K using inverse gas chromatography (IGC) at infinite dilution. Plasma treatment brings about increases in the specific free energy of adsorption of either acidic, basic or amphoteric probe molecules, indicating creation of surface functionalities with various acid-base strengths. This helps to justify the improvement in interfacial adhesion in polycarbonate matrix composites following plasma treatment of carbon fibres.

  1. DETAILED ANALYSIS OF THE MOST PROMISING ALTERNATIVES TO USING GRANULAR ACTIVATED CARBON TO TREAT 200-ZP-1 GROUNDWATER AND 200-PW-1 SOIL VAPOR

    Energy Technology Data Exchange (ETDEWEB)

    BYRNES ME, KALMAR JA

    2007-11-26

    This document presents a detailed evaluation of selected alternative treatment options to granular activated carbon (GAC) for removing carbon tetrachloride generated from the groundwater pump-and-treat system at the 200-ZP-I Operable Unit (OU) in the 200 West Area of the Hanford Site. This evaluation of alternative treatment options to GAC is also applicable to the vadose zone soil vapor extraction (SVE) system at the 200-PW-l OU, which is also located in the Hanford Site's 200 West Area.

  2. 脱汞载硫活性炭的制备及表征%Preparation and Characterization of Sulfur-loaded Activated Carbon for Mercury Removal

    Institute of Scientific and Technical Information of China (English)

    范莉莉; 刘晓玲; 刘霞

    2016-01-01

    In this paper, the preparation of sulfur-loaded activated carbon was studied,Taixi Coal Based-Activated Carbon used as the carrier. Some factors were discussed such as the carbon tetrachloride adsorption, S/C and dipping time on the influence of amount of sulfur. Meantime the structure of the prepared carrier was characterized by BET. The results showed that:when the carbon tetrachloride adsorption value was 60%, S/C was 14%, and the time was 24h, the sulfur content of the prepared activated carbon was 10.89%, and the solvent recovery rate was 90%.%本文以太西煤基活性炭为载体,研究了载硫活性炭的制备工艺,并探讨了四氯化碳吸附值、S/C和浸渍时间对载硫量的影响,同时采用BET表征对制备的载硫体的结构进行了表征。结果表明:当四氯化碳吸附值为60%,S/C为14%,浸渍时间为24h时,所制备的载硫活性炭载硫量最高为10.89%,且溶剂回收率高达90%。

  3. Hepatoprotective Effect of the Aqueous Extract of Simarouba amara Aublet (Simaroubaceae Stem Bark against Carbon Tetrachloride (CCl4-Induced Hepatic Damage in Rats

    Directory of Open Access Journals (Sweden)

    Hélida M. L. Maranhão

    2014-10-01

    Full Text Available Simarouba amara stem bark decoction has been traditionally used in Brazil to treat malaria, inflammation, fever, abdominal pain, diarrhea, wounds and as a tonic. In this study, we investigate the hepatoprotective effects of the aqueous extract of S. amara stem bark (SAAE on CCl4-induced hepatic damage in rats. SAAE was evaluated by high performance liquid chromatography. The animals were divided into six groups (n = 6/group. Groups I (vehicle—corn oil, II (control-CCl4, III, IV, V and VI were pretreated during 10 consecutive days, once a day p.o, with Legalon® 50 mg/kg b.w, SAAE at doses 100, 250 and 500 mg/kg b.w, respectively. The hepatotoxicity was induced on 11th day with 2 mL/kg of 20% CCl4 solution. 24 h after injury, the blood samples were collected and their livers were removed to biochemical and immunohistochemical analyzes. The SAAE decreased the levels of liver markers and lipid peroxidation in all doses and increased the catalase levels at doses 250 and 500 mg/kg. Immunohistochemical results suggested hepatocyte proliferation in all doses. These results may be related to catechins present in SAAE. Thus, SAAE prevented the oxidative damage at the same time that increased regenerative and reparative capacities of the liver.

  4. Ameliorative and antidyslipidemic potentials of aqueous leaf extract of Gongronema latifolium in CCl4 carbon tetrachloride-induced oxidative stress rats

    Directory of Open Access Journals (Sweden)

    Asiat Na’Allah

    2016-10-01

    Full Text Available Objective: To investigate the effect of leaf aqueous extract from Gongronema latifolium (G. latifolium on CCl4 induced-oxidative stress in Wistar rat. This effect was assessed by measuring liver marker enzymes activity, analyzing the antioxidant parameters, lipid profile estimation and lipid peroxidation by-product following CCl4 induced-oxidative stress. Methods: Milled G. latifolium leaves were subjected to aqueous extraction and the filtrate was evaporated between 40–60 °C under reduced pressure and a calculated volume of the leaf extract was administered at a dose of 500 mg/kg body weight. Thirty-five rats were grouped into seven groups of 5 animals each namely; control and experimental groups. The experimental groups were treated with 2.0 mL/kg body weight CCl4, 25 mg/kg body weight/ day silymarin (a standard hepatoprotective antioxidant, 500 mg/kg body weight aqueous extract of G. latifolium leaves were administered to the CCl4 treated rats for 21 days. Results: Administration of the extract and silymarin increase significantly (P < 0.05 in liver marker enzyme (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transpeptidase activities in serum, liver and kidney in the treated groups when compared with untreated groups. The antioxidant parameters (catalase, peroxidase and glutathione S-transferase were significantly elevated (P < 0.05 in animals treated with the extract and silymarin in comparison with untreated groups. CCl4 induced oxidative stress mediated variations in total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low density lipoprotein cholesterol and very low-density lipoprotein cholesterol were restored significantly (P < 0.05 by the extract. Conclusions: The result obtained from this study indicated the antioxidant and antidyslipidemic potentials of the aqueous extract of G. latifolium leaves.

  5. 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.

  6. Ameliorative and antidyslipidemic potentials of aqueous leaf extract ofGongronema latifoliumin CCl4 carbon tetrachloride-induced oxidative stress rats

    Institute of Scientific and Technical Information of China (English)

    Asiat NaAllah; Aliu Babajide Sanusi; Hamdala AjokeOwoniyi; Abdulhakeem Olarewaju Sulyman; Jubril Olayinka Akolade

    2016-01-01

    Objective:To investigate the effect of leaf aqueous extract fromGongronema latifolium (G. latifolium) on CCl4 induced-oxidative stress in Wistar rat. This effect was assessed by measuring liver marker enzymes activity, analyzing the antioxidant parameters, lipid profile estimation and lipid peroxidation by-product following CCl4 induced-oxidative stress. Methods: MilledG. latifolium leaves were subjected to aqueous extraction and the filtrate was evaporated between 40–60°C under reduced pressure and a calculated volume of the leaf extract was administered at a dose of 500 mg/kg body weight. Thirty-five rats were grouped into seven groups of 5 animals each namely; control and experimental groups. The experimental groups were treated with 2.0 mL/kg body weight CCl4, 25 mg/kg body weight/day silymarin (a standard hepatoprotective antioxidant), 500 mg/kg body weight aqueous extract ofG. latifolium leaves were administered to the CCl4 treated rats for 21 days. Results: Administration of the extract and silymarin increase significantly (P < 0.05) in liver marker enzyme (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and gamma-glutamyl transpeptidase) activities in serum, liver and kidney in the treated groups when compared with untreated groups. The antioxidant parameters (catalase, peroxidase and glutathioneS-transferase) were significantly elevated (P < 0.05) in animals treated with the extract and silymarin in comparison with untreated groups. CCl4 induced oxidative stress mediated variations in total cholesterol, triacylglycerides, high-density lipoprotein cholesterol, low density lipoprotein cholesterol and very low-density lipoprotein cholesterol were restored significantly (P < 0.05) by the extract. Conclusions: The result obtained from this study indicated the antioxidant and antidyslipidemic potentials of the aqueous extract ofG. latifolium leaves.

  7. Determining Dissolved Oxygen with Carbon Tetrachloride Visual Colorimetry%四氯化碳显色法测定溶解氧

    Institute of Scientific and Technical Information of China (English)

    韩丽媛

    2011-01-01

    This paper introduces a new method for determining the content of dissolved oxygen. The method is suitable for emergent monitoring thanks to its speed, accuracy, manifest result of analysis.%本文介绍了一种测定溶解氧的新方法。此方法快速、准确、分析结果直观、适合应急监测。

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

    Directory of Open Access Journals (Sweden)

    Parashuram Teli

    2015-01-01

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

  9. Synthesis of linear alkylbenzene sulphonate intercalated iron(II) iron(III) hydroxide sulphate (green rust) and adsorption of carbon tetrachloride

    DEFF Research Database (Denmark)

    Ayala Luis, Karina Barbara; Kaldor, D.K.; Bender Koch, Christian;

    2007-01-01

    Green rusts, GRs, can act as both sorbents and reductants towards selected pollutants. Organo-GRs are expected to combine these properties with a high affinity for hydrophobic substances. A novel organo-GR, GRLAS, was synthesized by incorporating a mixture of linear alkylbenzenesulphonates (LAS......) into the interlayer space of synthetic sulphate green rust, GR . Mössbauer analysis of GRLAS indicates that the structure of the organo-GR is very similar to SO4 that of the initial GR with regard to the FeII/FeIII ratio and local coordination of Fe atoms. X-ray SO4 diffraction demonstrates that the GRLAS formed...

  10. Antioxidant and Prophylactic Effects of Delonix elata L., Stem Bark Extracts, and Flavonoid Isolated Quercetin against Carbon Tetrachloride-Induced Hepatotoxicity in Rats

    Directory of Open Access Journals (Sweden)

    Pradeepa Krishnappa

    2014-01-01

    Full Text Available Delonix elata L. (Ceasalpinaceae, is widely used by the traditional medical practitioners of Karnataka, India, to cure jaundice, and bronchial and rheumatic problems. The objective of this study was to screen the in vitro antioxidant and hepatoprotective activity of the stem bark extracts against CCl4-induced liver damage in rats. Among different stem bark extracts tested, the ethanol extract (DSE has shown significant in vitro antioxidant property in radicals scavenging, metal chelating, and lipid peroxidation inhibition assays. HPLC analysis of the DSE revealed the presence of known antioxidant molecules, namely, gallic acid, ellagic acid, coumaric acid, quercetin, and rutin. Bioassay-guided fractionation of DSE has resulted in the isolation and characterization of quercetin. DSE and quercetin have shown significant prophylactic effects by restoring the liver function markers (AST, ALT, ALP, serum bilirubin, and total protein and antioxidant enzymes (SOD, CAT, GPx, and GST. These results were proved to be hepatoprotective at par with silymarin and well supported by the histological observations of liver sections with distinct hepatic cells, and mild degree of fatty change and necrosis. The results indicated that the DSE and quercetin were significant for prophylactic activity against CCl4-induced liver damage in rats. This activity could be attributed to the antioxidant constituents in the DSE and hence justified the ethnomedicinal claims.

  11. Hepatoprotective effects of Nigella sativa L and Urtica dioica L on lipid peroxidation, antioxidant enzyme systems and liver enzymes in carbon tetrachloride-treated rats

    Institute of Scientific and Technical Information of China (English)

    Mehmet Kanter; Omer Coskun; Mustafa Budancamanak

    2005-01-01

    AIM: To investigate the effects of Nigella sativa L (NS)and Urtica dioica L (UD) on lipid peroxidation, antioxidant enzyme systems and liver enzymes in CCl4-treated rats.METHODS: Fifty-six healthy male Wistar albino rats were used in this study. The rats were randomly allotted into one of the four experimental groups: A (CCl4-only treated), B (CCl4+UD treated), C (CCl4+NS treated) and D (CCl4+UD+NS treated), each containing 14 animals.All groups received CCl4 (0.8 mL/kg of body weight, sc,twice a week for 60 d). Tn addition, B, C and D groups also received daily J.p. injections of 0.2 mL/kg NS or/and 2 mL/kg UD oils for 60 d. Group A, on the other hand,received only 2 mL/kg normal saline solution for 60 d.Blood samples for the biochemical analysis were taken by cardiac puncture from randomly chosen-seven rats in each treatment group at beginning and on the 60th d of the experiment.RESULTS: The CCl4 treatment for 60 d increased thelipid peroxidation and liver enzymes,and also decreasedthe antioxidant enzyme levels. NS or UD treatment (aloneor combination) for 60 d decreased the elevated lipidperoxidation and liver enzyme levels and also increasedthe reduced antioxidant enzyme levels.The weight ofrats decreased in group A,and increased in groups B, Cand D.CONCLUSION: NS and UD decrease the lipid peroxidation and liver enzymes, and increase the antioxidant defense system activity in the CCl4-treated rats.

  12. Physiologically-based pharmacokinetic (PBPK) modeling of two binary mixtures: metabolic activation of carbon tetrachloride by trichloroethylene and metabolic inhibition of chloroform by trichloroethylene.

    Science.gov (United States)

    The interaction between trichloroethylene (TCE) and chloroform (CHCI3) has been described as less than additive, with co-exposure to TCE and CHC13 resulting in less hepatic and renal toxicity than observed with CHCl3 alone. In contrast, the nonadditive interaction between TCE and...

  13. Carbon Carbon Composites: An Overview .

    Directory of Open Access Journals (Sweden)

    G. Rohini Devi

    1993-10-01

    Full Text Available Carbon carbon composites are a new class of engineering materials that are ceramic in nature but exhibit brittle to pseudoplastic behaviour. Carbon-carbon is a unique all-carbon composite with carbon fibre embeded in carbon matrix and is known as an inverse composite. Due to their excellent thermo-structural properties, carbon-carbon composites are used in specialised application like re-entry nose-tips, leading edges, rocket nozzles, and aircraft brake discs apart from several industrial and biomedical applications. The multidirectional carbon-carbon product technology is versatile and offers design flexibility. This paper describes the multidirectional preform and carbon-carbon process technology and research and development activities within the country. Carbon-carbon product experience at DRDL has also been discussed. Development of carbon-carbon brake discs process technology using the liquid impregnation process is described. Further the test results on material characterisation, thermal, mechanical and tribological properties are presented.

  14. Hepatoprotective activity of LIV-first against carbon tetra chloride-induced hepatotoxicity in albino rats

    Directory of Open Access Journals (Sweden)

    Lima T

    2010-01-01

    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, LIV-first (16.3 mg/kg, p.o. was used to screen the hepatoprotective activity. Hepatotoxicity was induced in experimental animals by administration of carbon tetrachloride (CCl 4 (1 ml/kg, i.p. Silymarin (25 mg/kg,p.o. was used as the standard. Biochemical parameters like serum glutamate oxaloacetate transaminase (SGOT, serum glutamate pyruvate transaminase (SGPT, alkaline phosphatase (ALP and serum bilirubin were measured. Cytotoxicity of CCl 4 was estimated by quantitating the release of malondialdehyde. The activity of tissue antioxidant enzymes namely superoxide dismutase, catalase and the level of total protein and glutathione were also measured. Histopathological evaluation of liver sections was also done. CCl 4 administration in rats elevated the levels of SGPT, SGOT, ALP and bilirubin. Administration of LIV-first significantly ( P< 0.01 prevented this increase. The activity of anti-oxidant enzymes in carbon tetrachloride CCl 4 -treated group was decreased and these enzyme levels were significantly ( P< 0.05 increased in LIV-first-treated groups. Histopathological studies revealed that the concurrent administration of CCl 4 with the extract exhibited protection of the liver tissue, which further evidenced the above results. The study confirmed the hepatoprotective activity of LIV-first, which may be attributed to its antioxidant property.

  15. Carbon/nitrogen-doped TiO2: New synthesis route, characterization and application for phenol degradation

    Directory of Open Access Journals (Sweden)

    Aboubakr M. Abdullah

    2016-03-01

    Full Text Available Porous nanocrystalline carbon and nitrogen (CN-doped TiO2 photocatalyst was prepared using carbon tetrachloride and polyaniline as precursors. The obtained powders were characterized by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, scanning electron microscopy (SEM, Raman spectroscopy, Fourier transform infrared (FT-IR spectroscopy, and gravimetric analysis. The purpose of this work was to explore the state and location of nitrogen and carbon atoms introduced inside the TiO2 lattice and to study the exploitation of the photocatalytic activity of the CN-doped TiO2 for application in phenol degradation under UV illumination. After 30 min from the illumination onset, 64% and 57% of the phenol were degraded when the CN-doped TiO2 and TiO2 catalysts were used respectively.

  16. Bonding titanium on multi-walled carbon nanotubes for hydrogen storage: An electrochemical approach

    Energy Technology Data Exchange (ETDEWEB)

    Brieno-Enriquez, K.M.; Ledesma-Garcia, J. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S.C., Parque Tecnologico Queretaro-Sanfandila, Pedro Escobedo, Qro, C.P. 76703 (Mexico); Perez-Bueno, J.J., E-mail: jperez@cideteq.mx [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S.C., Parque Tecnologico Queretaro-Sanfandila, Pedro Escobedo, Qro, C.P. 76703 (Mexico); Godinez, Luis A. [Centro de Investigacion y Desarrollo Tecnologico en Electroquimica, S.C., Parque Tecnologico Queretaro-Sanfandila, Pedro Escobedo, Qro, C.P. 76703 (Mexico); Terrones, H. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Division de Materiales Avanzados, Camino a la Presa San Jose 2055, Col. Lomas 4o Seccion C.P. 78216, San Luis Potosi (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Programa de Ingenieria Molecular, Eje Central Lazaro Cardenas 152, A.P. 14-805, 07730 Mexico D.F. (Mexico)

    2009-06-15

    This work explores the use of some procedures, involving electrochemistry, in order to bond atomic Ti on the outer surface of multi-walled carbon nanotubes (MWNTs). It is assumed that each titanium atom has the potential of host up to four hydrogen molecules and relinquish them by heated. As a way to spread and stick nanotubes on an electrode, a tested route was drying a solution with nanotubes on a glassy carbon flat electrode. The MWNTs were treated by anodic polarization in organic media. Dichloromethane was selected as the medium and titanium tetrachloride as the precursor for attaching atomic Ti onto the nanotubes. The hydrogen adsorption, estimated from voltamperometry was five times higher on Ti-MWNTs that on bare nanotubes. The use of anodic polarization during the preparation of Ti-MWNTs may represent great significance in procedure, which was manifest during the voltamperometric evaluation of samples.

  17. Carbonized asphaltene-based carbon-carbon fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, George; Lula, James; Bowen, III, Daniel E.

    2016-12-27

    A method of making a carbon binder-reinforced carbon fiber composite is provided using carbonized asphaltenes as the carbon binder. Combinations of carbon fiber and asphaltenes are also provided, along with the resulting composites and articles of manufacture.

  18. Study on Preparation Technology of TEOS from Silicon Tetrachloride%SiCl4制备正硅酸乙酯的工艺研究

    Institute of Scientific and Technical Information of China (English)

    赵云; 师琳霞; 但建明; 齐誉; 洪成林

    2014-01-01

    In this article,tetraethyl orthosilicate (TEOS) was prepared using silicon tetrachloride and alcohol as the raw materials. Effects of the ratio of SiCl4 and alcohol,reaction temperature,reaction time on yield and purity of TEOS were studied based on semi-continuous process.The results of orthogonal experiment indicated:At 15 ℃,14.21 g alcohol at a constant rate was dropped into 15 g SiCl4.After reaction 35 min,8.12 g alcohol was supplemented,then at 55 ℃ constant temperature 40 min.The yield of TEOS was up to 86.61% after removing low boiling point alcohol and hydrogen chloride through vacuum distillation. IR and GC demonstrated that the structure of TEOS was correct and its purity was over 99.0% and reach analytical reagent.%为寻找一条工序简单、耗价低、易于工业放大路线,实现多晶硅副产物四氯化硅(SiCl4)废物资源化制备正硅酸乙酯(TEOS),本文以多晶硅副产物SiCl4和无水乙醇为原料制备TEOS,在半连续化生产工艺的基础上研究了SiCl4与乙醇的摩尔比、反应温度、反应时间等因素对TEOS产率及纯度的影响。正交实验优化结果表明:15℃下,以恒定速率滴加14.21 g无水乙醇于15 g四氯化硅中,反应35 min,补加8.12 g无水乙醇;55℃下恒温40 min,经减压蒸馏,除去低沸点的乙醇和氯化氢,TEOS产率达到86.61%。对正交实验优水平下制得的产物进行红外光谱(IR)和气相色谱(GC)分析,结果表明:产物中TEOS结构正确,其纯度大于99.0%,达到市售分析纯纯度。

  19. Preparation of ZrC nano-particles reinforced amorphous carbon composite coating by atmospheric pressure chemical vapor deposition

    Science.gov (United States)

    Sun, W.; Xiong, X.; Huang, B. Y.; Li, G. D.; Zhang, H. B.; Xiao, P.; Chen, Z. K.; Zheng, X. L.

    2009-05-01

    To eliminate cracks caused by thermal expansion mismatch between ZrC coating and carbon-carbon composites, a kind of ZrC/C composite coating was designed as an interlayer. The atmospheric pressure chemical vapor deposition was used as a method to achieve co-deposition of ZrC and C from ZrCl 4-C 3H 6-H 2-Ar source. Zirconium tetrachloride (ZrCl 4) powder carrier was especially made to control accurately the flow rate. The microstructure of ZrC/C composite coating was studied using analytical techniques. ZrC/C coating shows same morphology as pyrolytic carbon. Transmission electron microscopy (TEM) shows ZrC grains with size of 10-50 nm embed in turbostratic carbon. The formation mechanism is that the growth of ZrC crystals was inhibited by surrounding pyrolytic carbon and kept as nano-particles. Fracture morphologies imply good combination between coating and substrate. The ZrC crystals have stoichiometric proportion near 1, with good crystalline but no clear preferred orientation while pyrolytic carbon is amorphous. The heating-up oxidation of ZrC/C coating shows 11.58 wt.% loss. It can be calculated that the coating consists of 74.04 wt.% ZrC and 25.96 wt.% pyrolytic carbon. The average density of the composite coating is 5.892 g/cm 3 by Archimedes' principle.

  20. Carbonate aquifers

    Science.gov (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  1. Carbon classified?

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2012-01-01

    How does a corporation know it emits carbon? Acquiring such knowledge starts with the classification of environmentally relevant consumption information. This paper visits the corporate location at which this underlying element for their knowledge is assembled to give rise to carbon emissions. Us...

  2. Porous carbons

    Indian Academy of Sciences (India)

    Satish M Manocha

    2003-02-01

    Carbon in dense as well as porous solid form is used in a variety of applications. Activated porous carbons are made through pyrolysis and activation of carbonaceous natural as well as synthetic precursors. Pyrolysed woods replicate the structure of original wood but as such possess very low surface areas and poor adsorption capacities. On activation, these exhibit increased adsorption volumes of 0.5–0.8 cm3 /gm and surface areas of 700–1800 m2 /gm depending on activation conditions, whether physical or chemical. Former carbons possess mixed pore size distribution while chemically activated carbons predominantly possess micropores. Thus, these carbons can be used for adsorption of wide distributions of molecules from gas to liquid. The molecular adsorption within the pores is due to single layer or multilayer molecule deposition at the pore walls and hence results in different types of adsorption isotherm. On the other hand, activated carbon fibres with controlled microporous structure and surface area in the range of 2500 m2 /gm can be developed by controlled pyrolysis and physical activation of amorphous carbon fibres. Active carbon fibres with unmatchable pore structure and surface characteristics are present and futuristic porous materials for a number of applications from pollution control to energy storage.

  3. Carbon photonics

    Energy Technology Data Exchange (ETDEWEB)

    Konov, V I [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-11-30

    The properties of new carbon materials (single-crystal and polycrystalline CVD diamond films and wafers, single-wall carbon nanotubes and graphene) and the prospects of their use as optical elements and devices are discussed. (optical elements of laser devices)

  4. Synergistic effect of carbon monoxide with other biologically active injurious factors on the organism

    Energy Technology Data Exchange (ETDEWEB)

    Pankow, D.; Ponsold, W.

    1974-09-01

    The combined effects on biological organisms are reported for carbon monoxide and carbon dioxide, nitrogen oxides, sodium nitrite, hydrocyanic acid, carbon disulfide, sulfur dioxide, ammonia, hydrogen peroxide, ethanol, trichloroethylene, carbon tetrachloride, methane, benzene, iodine acetate, cholesterol, benzpyrene, hexobarbitol, zoxazolamine, nembutal, luminal, morphine, adrenalin, persantin, cytochrome c, aldrin, carbaryl, cyclodiene epoxide; and physical influences such as ambient temperature, atmospheric pressure, ionizing radiation, noise, and vibration. A literature review shows that with increasing CO/sub 2/ and decreasing oxygen concentration in the inhalation air, the toxicity of CO increased in experiments with mice and canaries. Oxides of nitrogen enhance the toxic effect of CO in an additive way and at times synergistically. At 500 m from a metallurgical plant in the USSR the maximum allowable immission concentrations for CO and SO/sub 2/ were exceeded. In children residing there a higher normal erythrocyte number, hemoglobin content, and catalase activity were found in the blood along with higher concentrations of coproporphyrin and 17-ketosteroids. All values returned to normal after an 8-week stay of these children away from the metallurgical plant.

  5. Carbon-Carbon Piston Architectures

    Science.gov (United States)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved structure for carbon-carbon composite piston architectures is disclosed. The improvement consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat.No. 4,909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially, the carbon fabric of tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel, to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar, or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U"-channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.

  6. Carbon cyclist

    Science.gov (United States)

    Showstack, Randy

    A satellite launched in early August as part of NASA's Mission to Planet Earth could dramatically increase understanding of how carbon cycles through the Earth's biosphere and living organisms and how this process influences global climate. The Sea-viewing Wide Field-of-View Sensor (SeaWiFS) will measure the color of the oceans with a radiometer to determine the concentration of chlorophyll found in oceanic phytoplankton. The single-celled plants, at the base of food chains around the world, remove carbon dioxide from seawater through photosynthesis, which allows oceans to absorb more carbon dioxide from the atmosphere.

  7. Carbon Stars

    Indian Academy of Sciences (India)

    T. Lloyd Evans

    2010-12-01

    In this paper, the present state of knowledge of the carbon stars is discussed. Particular attention is given to issues of classification, evolution, variability, populations in our own and other galaxies, and circumstellar material.

  8. Carbon Nanoelectronics

    Directory of Open Access Journals (Sweden)

    Cory D. Cress

    2014-01-01

    Full Text Available Initiated by the first single-walled carbon nanotube (SWCNT transistors [1,2], and reinvigorated with the isolation of graphene [3], the field of carbon-based nanoscale electronic devices and components (Carbon Nanoelectronics for short has developed at a blistering pace [4]. Comprising a vast number of scientists and engineers that span materials science, physics, chemistry, and electronics, this field seeks to provide an evolutionary transition path to address the fundamental scaling limitations of silicon CMOS [5]. Concurrently, researchers are actively investigating the use of carbon nanomaterials in applications including back-end interconnects, high-speed optoelectronic applications [6], spin-transport [7], spin tunnel barrier [8], flexible electronics, and many more.

  9. Infiltrated carbon foam composites

    Science.gov (United States)

    Lucas, Rick D. (Inventor); Danford, Harry E. (Inventor); Plucinski, Janusz W. (Inventor); Merriman, Douglas J. (Inventor); Blacker, Jesse M. (Inventor)

    2012-01-01

    An infiltrated carbon foam composite and method for making the composite is described. The infiltrated carbon foam composite may include a carbonized carbon aerogel in cells of a carbon foam body and a resin is infiltrated into the carbon foam body filling the cells of the carbon foam body and spaces around the carbonized carbon aerogel. The infiltrated carbon foam composites may be useful for mid-density ablative thermal protection systems.

  10. Silver/Carbon Codoped Titanium Dioxide Photocatalyst for Improved Dye Degradation under Visible Light

    Directory of Open Access Journals (Sweden)

    P. Nyamukamba

    2017-01-01

    Full Text Available Herein, we report the synthesis of quartz supported TiO2 photocatalysts codoped with carbon and silver through the hydrolysis of titanium tetrachloride followed by calcination at 500°C. The prepared samples were characterized by UV-Vis diffuse reflectance spectroscopy, high resolution scanning electron microscopy (HRSEM, Raman spectroscopy, thermogravimetric analysis (TGA, X-ray photoelectron spectroscopy (XPS, and X-ray diffraction (XRD. Codoping of TiO2 with Ag and carbon resulted in an increase in the surface area of the photocatalyst and altered the ratio of the anatase to rutile phase. The absorption edge of all the doped TiO2 photocatalysts redshifted and the band gap was reduced. The lowest band gap of 1.95 eV was achieved by doping with 0.5% Ag. Doping TiO2 using carbon as the only dopant resulted in a quartz supported photocatalyst that showed greater photocatalytic activity towards methyl orange than undoped TiO2 and also all codoped TiO2 photocatalysts under visible light irradiation.

  11. Laser oxidative pyrolysis synthesis and annealing of TiO2 nanoparticles embedded in carbon-silica shells/matrix

    Science.gov (United States)

    Fleaca, C. T.; Scarisoreanu, M.; Morjan, I.; Luculescu, C.; Niculescu, A.-M.; Badoi, A.; Vasile, E.; Kovacs, G.

    2015-05-01

    Titania nanoparticles containing a mixture of anatase and rutile phases (with mean crystalline sizes up to 24 nm) covered with/embedded in carbon/silica thin layers or matrix were obtained in a single step using laser oxidative pyrolysis. Titanium tetrachloride and hexamethyldisiloxane (HMDSO) vapors were separately introduced into the reaction zone - both together with the laser-absorbing agent (sensitizer) ethylene - which acts also as carbon source - and the oxidant (air) - through the inner and the concentric nozzle, respectively. By increasing the air flow through the annular nozzle, while keeping constant the TiC4, inner air, HMDSO and C2H4 flows, the atomic carbon concentration as well as the rutile to anatase ratio in the resulted nanopowders decrease. A much brighter and extended flame was observed for the experiment involving the greatest air flow. The Ti/Si atomic ratio in the resulted nanocomposites was higher than that from the introduced precursors (1.8), indicating a partial siloxane conversion to silica. The annealed powders (at 450 °C to further carbon content reducing) exhibit a lower bandgap energy than those of the reference sample without silica (and also lower than the commercial Degussa P25 nano-TiO2).

  12. Calcium Carbonate

    Science.gov (United States)

    ... doctor if you have or have ever had kidney disease or stomach conditions.tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking calcium carbonate, call your doctor.

  13. The van der Waals coefficients between carbon nanostructures and small molecules: A time-dependent density functional theory study.

    Science.gov (United States)

    Kamal, C; Ghanty, T K; Banerjee, Arup; Chakrabarti, Aparna

    2009-10-28

    We employ all-electron ab initio time-dependent density functional theory based method to calculate the long-range dipole-dipole dispersion coefficient, namely, the van der Waals (vdW) coefficient (C(6)) between fullerenes and finite-length carbon nanotubes as well as between these structures and different small molecules. Our aim is to accurately estimate the strength of the long-range vdW interaction in terms of the C(6) coefficients between these systems and also compare these values as a function of shape and size. The dispersion coefficients are obtained via Casimir-Polder relation. The calculations are carried out with the asymptotically correct exchange-correlation potential-the statistical average of orbital potential. It is observed from our calculations that the C(6) coefficients of the carbon nanotubes increase nonlinearly with length, which implies a much stronger vdW interaction between the longer carbon nanostructures compared with the shorter ones. Additionally, it is found that the values of C(6) and polarizability are about 40%-50% lower for the carbon cages when compared with the results corresponding to the quasi-one-dimensional nanotubes with equivalent number of atoms. From our calculations of the vdW coefficients between the small molecules and the carbon nanostructures, it is observed that for H(2), the C(6) value is much larger compared with that of He. It is found that the rare gas atoms have very low values of vdW coefficient with the carbon nanostructures. In contrast, it is found that other gas molecules, including the ones that are environmentally important, possess much higher C(6) values. Carbon tetrachloride as well as chlorine molecule show very high C(6) values with themselves as well as with the carbon nanostructures. This is due to the presence of the weakly bound seven electrons in the valence state for the halogen atoms, which makes these compounds much more polarizable compared with the others.

  14. Synthesis, characterizations, and applications of carbon nanotubes and silicon nanowires

    Science.gov (United States)

    Xiong, Guangyong

    Carbon nanotubes (CNTs) have received great attention because of their unique structure and promising applications in microelectronic devices such as field electron emitters. Silicon nanowires (SiNWs) are also very popular because Si is a well established electronic material. This thesis will present my effort on synthesis, characterizations, and applications of CNTs and SiNWs by thermal chemical vapor deposition (CVD) method. For CNTs growth, block copolymer micelles were used as a template to create large area arrays of metal nanoclusters as catalysts for patterned arrays, and Fe/Al/Fe sandwich film on single crystal magnesium oxide (MgO) substrate was used as the catalyst for growth of long length aligned CNTs by CVD. The factors that affect the structure and length of CNTs have been investigated. CNTs were also grown on etched Si substrate by PECVD method. Continuous dropwise condensation was achieved on a biomimetic two-tier texture with short CNTs deposited on micromachined pillars. Superhydrophobic condensation model was studied. For SiNWs growth, hydrogen gold tetrachloride was uniformly mixed into the salt and decomposed into gold nanoparticles at the growth temperature and acted as the catalyst particles to start the growth of Si nanowires. The as-grown Si nanowires are about 70--90 nm in diameter and up to 200 micrometers long. The salt was completely removed by water rinse after growth. Field emission of aligned CNTs grown on Si substrates and SiNWs on Si substrates and carbon clothes has been studied. A post growth annealing procedure has been found to drastically improve the field emission performance of these CNTs and SiNWs.

  15. Health risk assessment of trichloromethane and carbon tetrachloride in drinking water, Jurong%句容市饮用水中三氯甲烷和四氯化碳健康风险评价

    Institute of Scientific and Technical Information of China (English)

    董淑江; 尹艳

    2015-01-01

    目的 初步评价句容市生活饮用水中三氯甲烷和四氯化碳对人体健康产生的潜在危害.方法 于2014年丰水期和枯水期,对句容市饮用水中的三氯甲烷和四氯化碳进行检测,并对饮水途径所引起的健康风险做出初步评价.结果 句容市饮水中三氯甲烷、四氯化碳的平均浓度分别为0.0162 mg/L和0.00159 mg/L,合格率分别为100%和78.9%,致癌个人年风险为0.158×10-6/a和9.27×10-6/a,非致癌健康风险值个人年风险为5.09×10-2/a和7.13×10-2/a.结论 句容市饮用水中三氯甲烷和四氯化碳对人体的健康产生的潜在致癌个人年风险和非致癌健康风险均在美国环境保护署(USEPA)可以接受的限值之内.

  16. Study on Kinetics of Catalytic Hydrogenation of Carbon Tetrachloride to Produce Trichloromethane in Liquid Phase%四氯化碳液相催化加氢制氯仿反应动力学研究

    Institute of Scientific and Technical Information of China (English)

    张文革; 邵丽莉; 许建帼

    2008-01-01

    使用高压搅拌釜,在123 ℃实验条件下,对四氯化碳、二氯甲烷、三氯甲烷、催化剂组成的反应体系进行动力学研究,用最小二乘法对数据进行回归处理,并建立反应动力学方程.

  17. Comparison of cytoprotective effects of saponins isolated from leaves of Aralia elata Seem. (Araliaceae) with synthesized bisdesmosides of oleanoic acid and hederagenin on carbon tetrachloride-induced hepatic injury.

    Science.gov (United States)

    Saito, S; Ebashi, J; Sumita, S; Furumoto, T; Nagamura, Y; Nishida, K; Isiguro, I

    1993-08-01

    Glycosylations of 3-O-(2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl(1-->2)- 3,4-di-O-acetyl-alpha-L-arabinopyranosyl)-23-O-acetylhederageni n (15) with mono- (16), di- (17) and trisaccharide bromide (18) gave the bisdesmoside peracetates 19, 20 and 22, respectively, which were treated with 5% KOH in MeOH to give the bisdesmosides 25-27. Hydrolysis of the glycosides 6 and 9 having beta-D-glucopyranose as a terminal sugar component with beta-glucosidase in acetate buffer (pH 4.7) gave compounds 28 and 29, respectively. Cytoprotective effects of the synthesized triterpenoidal saponins against CCl4-induced hepatic injury were compared with those of saponins isolated from the leaves of Aralia elata Seem. (Araliaceae) using isolated hepatocytes from rat liver. Although the monodesmosides 1-4 having neutral sugar components only at the O-3 position on the aglycones showed no cytoprotective effect, bisdesmosides having sugar components at both the O-3 and O-28 positions on the aglycones had potent effects, even when the species of the sugar components were different. The bisdesmosides 10, 11, and 27 having five monosaccharides in the molecules exhibited the most potent cytoprotective effects.

  18. Research of Portal Hypertension Model of Rata Bunt by Subcutaneous Injection of Carbon Tetrachloride%四氯化碳复合、梯段用药法制备大鼠门脉高压模型的研究

    Institute of Scientific and Technical Information of China (English)

    徐义军; 王超

    2010-01-01

    目的 探讨构建一种稳定,可靠的门脉高压大鼠模型的制备方法,并研究该模型肝脏病理结构以及血流动力学的改变.方法 雄性SD大鼠95只,体重150~170g,按编号法随机分为模型组和对照组.模型组:按0.4mL/100g剂量予以背部皮下注射50%CCl4橄榄油溶液,每周2次,持续4周.第5周开始改为以0.5mL/100g标准注射,每周2次,持续4周.对照组:仅注射橄税油,频度及剂量同模型组.结果 对照组10只大鼠全部存活.模型组85只大鼠,死亡24只,死亡率28%.存活61只大鼠,肝脏均可观察到纤维组织不同程度地增生,肝小叶结构破坏,假小叶形成,模型成功率100%.模型组门静脉压力和门静脉内径比对照组明显增加(P<0.05);血清TB、ALT及AST较正常对照组均明显升高(P<0.05),而ALB则明显降低(P<0.05).结论 该方法所构建的动物模型其组织学改变与人类肝硬变相似,门静脉压力显著增高,是研究门脉高压症的理想模型.

  19. Aqueous Date Flesh or Pits Extract Attenuates Liver Fibrosis via Suppression of Hepatic Stellate Cell Activation and Reduction of Inflammatory Cytokines, Transforming Growth Factor-β1 and Angiogenic Markers in Carbon Tetrachloride-Intoxicated Rats

    Directory of Open Access Journals (Sweden)

    Nouf M. Al-Rasheed

    2015-01-01

    Full Text Available Previous data indicated the protective effect of date fruit extract on oxidative damage in rat liver. However, the hepatoprotective effects via other mechanisms have not been investigated. This study was performed to evaluate the antifibrotic effect of date flesh extract (DFE or date pits extract (DPE via inactivation of hepatic stellate cells (HSCs, reducing the levels of inflammatory, fibrotic and angiogenic markers. Coffee was used as reference hepatoprotective agent. Liver fibrosis was induced by injection of CCl4 (0.4 mL/kg three times weekly for 8 weeks. DFE, DPE (6 mL/kg, coffee (300 mg/kg, and combination of coffee + DFE and coffee + DPE were given to CCl4-intoxicated rats daily for 8 weeks. DFE, DPE, and their combination with coffee attenuated the elevated levels of inflammatory cytokines including tumor necrosis factor-α, interleukin-6, and interleukin-1β. The increased levels of transforming growth factor-β1 and collagen deposition in injured liver were alleviated by both extracts. CCl4-induced expression of α-smooth muscle actin was suppressed indicating HSCs inactivation. Increased angiogenesis was ameliorated as revealed by reduced levels and expression of vascular endothelial growth factor and CD31. We concluded that DFE or DPE could protect liver via different mechanisms. The combination of coffee with DFE or DPE may enhance its antifibrotic effects.

  20. 四氯乙烯替代四氯化碳作为石油类测定萃取剂研究%Tetrachloroethylene Replacing Carbon Tetrachloride as Extractant Determining Petroleum Content

    Institute of Scientific and Technical Information of China (English)

    张保华; 王亮; 雷岗星

    2013-01-01

    四氯化碳作为石油类萃取剂对人体毒害较大,破坏臭氧层,已被联合国环境规划署列入加速淘汰计划.本研究尝试用四氯乙烯替代四氯化碳作为石油类测定萃取剂.结果表明,二者在线性、检出限、精密度、萃取率、加标回收率、质控样品测定方面没有显著差异,该替代方法基本可行.

  1. 番茄红素对四氯化碳肝肾损伤的保护作用%Protection of Lycopene on Acute Damage of Liver and Kidney Induced by Carbon Tetrachloride in Rats

    Institute of Scientific and Technical Information of China (English)

    潘洪志; 万丽葵; 胡万胜; 张剑峰; 那立欣

    2005-01-01

    番茄红素(Lycopene)属于烃类类胡萝卜素,存在于红色水果和蔬菜中,研究发现番茄红素具有淬灭单线态氧和清除自由基、阻断亚硝胺形成、抑制细胞增殖、诱导细胞分化、减少DNA损伤及诱导细胞间隙连接通讯等作用。番茄红素能够减缓动脉粥样硬化,防止冠心病的发生。番茄红素的生物学作用主要是通过提高机体的抗氧化能力实现的心。本实验以四氯化碳制备动物脂质过氧化损伤模型,研究番茄红素对四氯化碳(CCl4)所致损伤的保护作用,并对其作用机制进行探讨。

  2. 用改性膨润土去除水中四氯化碳的试验研究%Research on Removing Carbon Tetrachloride from Groundwater Using Modified Bentonite

    Institute of Scientific and Technical Information of China (English)

    卢杰; 潘嘉芬; 李梦红

    2008-01-01

    为完善地下水中氯代烃污染物的处理技术,进行了用改性膨润土吸附模拟水样中四氯化碳的试验研究.试验结果表明:天然钙基膨润土经十六烷基三甲基溴化铵改性后,颗粒问间距明显增大,颗粒表面由亲水性变为疏水性,可有效吸附去除水中的四氯化碳,其适宜的吸附条件为膨润土投加量5 g/L、吸附时间2 h、吸附温度30℃.按此条件用改性膨润土处理某CCl4含量为1.60 ms/L的实际四氯化碳污染地下水,CCI4的去除率可达70%~80%.

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

    Institute of Scientific and Technical Information of China (English)

    Gonzàlez R; Ancheta O; Màrquez M; Rodriguez S

    1994-01-01

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

  4. The protective effect of matrine in primary cultured rat hepatotoxicity induced by carbon tetrachloride%氧化苦参碱对四氯化碳损伤大鼠肝细胞的保护作用

    Institute of Scientific and Technical Information of China (English)

    张红菱

    2002-01-01

    目的:研究氧化苦参碱对肝细胞的保护作用.方法:采用原代肝细胞培养的方法,选用CCl430 mmol/L制备肝损伤模型,同时加以不同浓度的氧化苦参碱以保护肝细胞,培养12 h后以MTT法测细胞存活率,并测定培养基中AST、ALT、LDH.结果:氧化苦参碱对肝细胞的保护呈剂量依赖性,氧化苦参碱组细胞存活率明显高于CCl4损伤组(98.3%/3.2%,P<0.05);其AST、ALT、LDH较CCl4损伤组明显降低(依次为6.13±0.44/896.87±13.23、21.5±0.76/1502.13±35.80、19.5±0.68/287.38±5.79,均P<0.05).结论:氧化苦参碱对CCl4损伤的肝细胞具较好的保护作用,存在最佳剂量性关系.

  5. Carbonic inclusions

    Science.gov (United States)

    Van den Kerkhof, Alfons; Thiéry, Régis

    2001-01-01

    The paper gives an overview of the phase relations in carbonic fluid inclusions with pure, binary and ternary mixtures of the system CO 2-CH 4-N 2, compositions, which are frequently found in geological materials. Phase transitions involving liquid, gas and solid phases in the temperature range between -192°C and 31°C are discussed and presented in phase diagrams ( PT, TX and VX projections). These diagrams can be applied for the interpretation of microthermometry data in order to determine fluid composition and molar volume (or density).

  6. Carbon Farming as a Carbon Negative Technology

    Science.gov (United States)

    Anderson, C.; Laird, D.; Hayes, D. J.

    2015-12-01

    Carbon farms have a pivotal role in national and international efforts to mitigate and adapt to climate change. A carbon farm in its broadest sense is one that reduces greenhouse gas (GHG) emissions or captures and holds carbon in vegetation and soils. Their capacity to remove carbon from the air and store it safely and permanently, while providing additional human and ecosystem benefits, means they could contribute significantly to national efforts to stabilize or reduce GHGs. We examine carbon farms in the context of corn and soybean production agriculture. We illustrate, using Iowa data but with relevance across United States corn and soybean production, the potential for carbon farms to reduce human GHG emissions and sequester carbon permanently at a rate that has meaningful impact on global greenhouse gas concentration. Carbon has been viewed as a next generation cash crop in Iowa for over a decade. The carbon farm perspective, however, goes beyond carbon as cash crop to make carbon the center of an entire farm enterprise. The transformation is possible through slight adjustment crop practices mixed with advances in technology to sequester carbon through biochar. We examine carbon balance of Iowa agriculture given only the combination of slight reduction in fertilizer and sequestration by biochar. We find the following. Iowa carbon farms could turn Iowa agriculture into a carbon sink. The estimated range of GHG reduction by statewide implementation of carbon farms is 19.46 to 90.27 MMt CO2-equivalent (CO2-e), while the current agricultural CO2-e emission estimate is 35.38 MMt CO2-e. Iowa carbon farm GHG reduction would exceed Iowa GHG reduction by wind energy (8.7 MMt CO2-e) and could exceed combined reductions from wind energy and corn grain ethanol (10.7 MMt CO2-e; 19.4 MMt CO2-e combined). In fact, Iowa carbon farms alone could exceed GHG reduction from national corn grain ethanol production (39.6 MMt CO2-e). A carbon price accessible to agricultural

  7. Carbon Monoxide Safety

    Science.gov (United States)

    ... Materials Working with the Media Fire Protection Technology Carbon monoxide safety outreach materials Help inform residents in ... with these messages and free materials. What is carbon monoxide? Carbon monoxide, also known as CO, is ...

  8. Carbon monoxide poisoning

    Science.gov (United States)

    ... and smokers. Carbon monoxide can harm a fetus (unborn baby still in the womb). Symptoms of carbon ... symptoms Outlook (Prognosis) Carbon monoxide poisoning can cause death. For those who survive, recovery is slow. How ...

  9. Net Ecosystem Carbon Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Net Ecosystem Carbon Flux is defined as the year-over-year change in Total Ecosystem Carbon Stock, or the net rate of carbon exchange between an ecosystem and the...

  10. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept beh

  11. Carbon Residence Times in Pedogenic Carbonate Pools

    Science.gov (United States)

    Monger, H.; Feng, Y.; Karnjanapiboonwang, A.

    2013-12-01

    Soil carbonate is a huge pool of terrestrial carbon that contains at least 930 to 940 Pg C and has influx rates on the order of 1 to 12 g CaCO3/m2/yr. Such large mass to flux ratios yield long mean residence times for carbon (e.g., 85,000 years)--assuming steady state. Like other global carbon pools, the soil carbonate pool has smaller sub-pools with higher influx rates and shorter mean residence times. For example, pedogenic carbonate in coppice dunes known to have formed since 1858 and carbonate formed on lithic artifacts in soils at archaeology sites suggests mean residence times can be as short as 120 years--again assuming steady state. Harder to assess are efflux rates as CO2 emissions or bicarbonate leaching. Some Bowen-ratio studies have nevertheless found evidence for CO2 emissions resulting from carbonate dissolution, and other studies have found evidence for bicarbonate leaching based on dissolution pipes through calcic horizons using soil morphology studies. Since an understanding of mean residence times are prerequisite for a better understanding of soil carbonate in the global carbon cycle, especially in a scenario of an expanding Aridosphere, more influx and efflux measurements are needed to evaluate the possibility of carbon sequestration by soil carbonate in hyperarid, arid, semiarid, or subhumid soils.

  12. Composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, S.T.; Pekala, R.W.; Kaschmitter, J.L.

    1997-05-06

    Carbon aerogels used as a binder for granulated materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivity and power to system energy. 1 fig.

  13. Composite carbon foam electrode

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Steven T. (San Leandro, CA); Pekala, Richard W. (Pleasant Hill, CA); Kaschmitter, James L. (Pleasanton, CA)

    1997-01-01

    Carbon aerogels used as a binder for granularized materials, including other forms of carbon and metal additives, are cast onto carbon or metal fiber substrates to form composite carbon thin film sheets. The thin film sheets are utilized in electrochemical energy storage applications, such as electrochemical double layer capacitors (aerocapacitors), lithium based battery insertion electrodes, fuel cell electrodes, and electrocapacitive deionization electrodes. The composite carbon foam may be formed by prior known processes, but with the solid particles being added during the liquid phase of the process, i.e. prior to gelation. The other forms of carbon may include carbon microspheres, carbon powder, carbon aerogel powder or particles, graphite carbons. Metal and/or carbon fibers may be added for increased conductivity. The choice of materials and fibers will depend on the electrolyte used and the relative trade off of system resistivty and power to system energy.

  14. Carbon Nanomembranes

    Science.gov (United States)

    Angelova, Polina; Gölzhäuser, Armin

    2017-03-01

    This chapter describes the formation and properties of one nanometer thick carbon nanomembranes (CNMs), made by electron induced cross-linking of aromatic self-assembled monolayers (SAMs). The cross-linked SAMs are robust enough to be released from the surface and placed on solid support or over holes as free-standing membranes. Annealing at 1000K transforms CNMs into graphene accompanied by a change of mechanical stiffness and electrical resistance. The developed fabrication approach is scalable and provides molecular level control over thickness and homogeneity of the produced CNMs. The mechanisms of electron-induced cross-linking process are discussed in details. A variety of polyaromatic thiols: oligophenyls as well as small and extended condensed polycyclic hydrocarbons have been successfully employed, demonstrating that the structural and functional properties of the resulting nanomembranes are strongly determined by the structure of molecular monolayers. The mechanical properties of CNMs (Young's modulus, tensile strength and prestress) are characterized by bulge testing. The interpretation of the bulge test data relates the Young's modulus to the properties of single molecules and to the structure of the pristine SAMs. The gas transport through the CNM is measured onto polydimethylsiloxane (PDMS) - thin film composite membrane. The established relationship of permeance and molecular size determines the molecular sieving mechanism of permeation through this ultrathin sheet.

  15. From carbon nanotubes to carbon atomic chains

    Science.gov (United States)

    Casillas García, Gilberto; Zhang, Weijia; José-Yacamán, Miguel

    2010-10-01

    Carbyne is a linear allotrope of carbon. It is formed by a linear arrangement of carbon atoms with sp-hybridization. We present a reliable and reproducible experiment to obtain these carbon atomic chains using few-layer-graphene (FLG) sheets and a HRTEM. First the FLG sheets were synthesized from worm-like exfoliated graphite and then drop-casted on a lacey-carbon copper grid. Once in the TEM, two holes are opened near each other in a FLG sheet by focusing the electron beam into a small spot. Due to the radiation, the carbon atoms rearrange themselves between the two holes and form carbon fibers. The beam is concentrated on the carbon fibers in order excite the atoms and induce a tension until multi wall carbon nanotube (MWCNT) is formed. As the radiation continues the MWCNT breaks down until there is only a single wall carbon nanotube (SWCNT). Then, when the SWCNT breaks, an atomic carbon chain is formed, lasts for several seconds under the radiation and finally breaks. This demonstrates the stability of this carbon structure.

  16. Carbon nanotube composite materials

    Energy Technology Data Exchange (ETDEWEB)

    O' Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  17. Mutagenicity of carbon nanomaterials

    DEFF Research Database (Denmark)

    Wallin, Håkan; Jacobsen, Nicklas Raun; White, Paul A;

    2011-01-01

    Carbon nanomaterials such carbon nanotubes, graphene and fullerenes are some the most promising nanomaterials. Although carbon nanomaterials have been reported to possess genotoxic potential, it is imperitive to analyse the data on the genotoxicity of carbon nanomaterials in vivo and in vitro...

  18. Electroanalysis with carbon paste electrodes

    CERN Document Server

    Svancara, Ivan; Walcarius, Alain; Vytras, Karel

    2011-01-01

    Introduction to Electrochemistry and Electroanalysis with Carbon Paste-Based ElectrodesHistorical Survey and GlossaryField in Publication Activities and LiteratureCarbon Pastes and Carbon Paste ElectrodesCarbon Paste as the Binary MixtureClassification of Carbon Pastes and Carbon Paste ElectrodesConstruction of Carbon Paste HoldersCarbon Paste as the Electrode MaterialPhysicochemical Properties of Carbon PastesElectrochemical Characteristics of Carbon PastesTesting of Unmodified CPEsIntera

  19. Mesoporous carbon materials

    Science.gov (United States)

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  20. Pyrolyzed thin film carbon

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Liger, Matthieu (Inventor); Harder, Theodore (Inventor); Konishi, Satoshi (Inventor); Miserendino, Scott (Inventor)

    2010-01-01

    A method of making carbon thin films comprises depositing a catalyst on a substrate, depositing a hydrocarbon in contact with the catalyst and pyrolyzing the hydrocarbon. A method of controlling a carbon thin film density comprises etching a cavity into a substrate, depositing a hydrocarbon into the cavity, and pyrolyzing the hydrocarbon while in the cavity to form a carbon thin film. Controlling a carbon thin film density is achieved by changing the volume of the cavity. Methods of making carbon containing patterned structures are also provided. Carbon thin films and carbon containing patterned structures can be used in NEMS, MEMS, liquid chromatography, and sensor devices.

  1. A novel application of carbon dots for colorimetric determination of fenitrothion insecticide based on the microextraction method

    Science.gov (United States)

    Larki, A.

    2017-02-01

    In this work, the intrinsic colorimetric property of carbon dots (CDs) was utilized for the determination of fenitrothion by applying dispersive liquid-liquid microextraction (DLLME) method. Label free CDs are extracted into carbon tetrachloride via assistance of trioctylmethylammonium chloride (Aliquat 336), which also acts as a disperser agent in this technique. The enriched CDs show an absorption signal at 365 nm, which increases in the presence of fenitrothion. The absorbance increase of CDs in organic phase was used as an analytical signal for the determination of fenitrothion. The synthesized CDs were characterized by UV-visible, fluorescence, Fourier transform infrared (FT-IR) and transmission electron microscopic (TEM). Under the optimized conditions, beer's law was obeyed in the range of 1.0-250.0 ng mL- 1 of fenitrothion with the limit of detection for fenitrothion was 0.2 ng mL- 1. The relative standard deviation for eight replicate measurements of fenitrothion at concentrations of 25 and 100 ng mL- 1 were calculated to be 1.5 and 3.7%, respectively. The proposed method was successfully applied in the determination of fenitrothion in water samples with satisfactory results.

  2. Adsorption of Carbon Dioxide on Activated Carbon

    Institute of Scientific and Technical Information of China (English)

    Bo Guo; Liping Chang; Kechang Xie

    2006-01-01

    The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Freundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.

  3. Carbon fuel cells with carbon corrosion suppression

    Science.gov (United States)

    Cooper, John F [Oakland, CA

    2012-04-10

    An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

  4. Metallic carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M.L.; Crespi, V.H.; Louie, S.G.S.; Zettl, A.K.

    1999-11-30

    Novel metallic forms of planar carbon are described, as well as methods of designing and making them. Nonhexagonal arrangements of carbon are introduced into a graphite carbon network essentially without destroying the planar structure. Specifically a form of carbon comprising primarily pentagons and heptagons, and having a large density of states at the Fermi level is described. Other arrangements of pentagons and heptagons that include some hexagons, and structures incorporating squares and octagons are additionally disclosed. Reducing the bond angle symmetry associated with a hexagonal arrangement of carbons increases the likelihood that the carbon material will have a metallic electron structure.

  5. Synthesis of carbon nanotubes.

    Science.gov (United States)

    Awasthi, Kalpana; Srivastava, Anchal; Srivastava, O N

    2005-10-01

    Carbon nanotubes play a fundamental role in the rapidly developing field of nanoscience and nanotechnology because of their unique properties and high potential for applications. In this article, the different synthesis methods of carbon nanotubes (both multi-walled and single-walled) are reviewed. From the industrial point of view, the chemical vapor deposition method has shown advantages over laser vaporization and electric arc discharge methods. This article also presents recent work in the controlled synthesis of carbon nanotubes with ordered architectures. Special carbon nanotube configurations, such as nanocoils, nanohorns, bamboo-shaped and carbon cylinder made up from carbon nanotubes are also discussed.

  6. Substantial global carbon uptake by cement carbonation

    Science.gov (United States)

    Xi, Fengming; Davis, Steven J.; Ciais, Philippe; Crawford-Brown, Douglas; Guan, Dabo; Pade, Claus; Shi, Tiemao; Syddall, Mark; Lv, Jie; Ji, Lanzhu; Bing, Longfei; Wang, Jiaoyue; Wei, Wei; Yang, Keun-Hyeok; Lagerblad, Björn; Galan, Isabel; Andrade, Carmen; Zhang, Ying; Liu, Zhu

    2016-12-01

    Calcination of carbonate rocks during the manufacture of cement produced 5% of global CO2 emissions from all industrial process and fossil-fuel combustion in 2013. Considerable attention has been paid to quantifying these industrial process emissions from cement production, but the natural reversal of the process--carbonation--has received little attention in carbon cycle studies. Here, we use new and existing data on cement materials during cement service life, demolition, and secondary use of concrete waste to estimate regional and global CO2 uptake between 1930 and 2013 using an analytical model describing carbonation chemistry. We find that carbonation of cement materials over their life cycle represents a large and growing net sink of CO2, increasing from 0.10 GtC yr-1 in 1998 to 0.25 GtC yr-1 in 2013. In total, we estimate that a cumulative amount of 4.5 GtC has been sequestered in carbonating cement materials from 1930 to 2013, offsetting 43% of the CO2 emissions from production of cement over the same period, not including emissions associated with fossil use during cement production. We conclude that carbonation of cement products represents a substantial carbon sink that is not currently considered in emissions inventories.

  7. Potassium carbonate poisoning

    Science.gov (United States)

    Potassium carbonate is a white powder used to make soap, glass, and other items. This article discusses poisoning from swallowing or breathing in potassium carbonate. This article is for information only. Do ...

  8. Sodium carbonate poisoning

    Science.gov (United States)

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  9. Carbon nanotube nanoelectrode arrays

    Science.gov (United States)

    Ren, Zhifeng; Lin, Yuehe; Yantasee, Wassana; Liu, Guodong; Lu, Fang; Tu, Yi

    2008-11-18

    The present invention relates to microelectode arrays (MEAs), and more particularly to carbon nanotube nanoelectrode arrays (CNT-NEAs) for chemical and biological sensing, and methods of use. A nanoelectrode array includes a carbon nanotube material comprising an array of substantially linear carbon nanotubes each having a proximal end and a distal end, the proximal end of the carbon nanotubes are attached to a catalyst substrate material so as to form the array with a pre-determined site density, wherein the carbon nanotubes are aligned with respect to one another within the array; an electrically insulating layer on the surface of the carbon nanotube material, whereby the distal end of the carbon nanotubes extend beyond the electrically insulating layer; a second adhesive electrically insulating layer on the surface of the electrically insulating layer, whereby the distal end of the carbon nanotubes extend beyond the second adhesive electrically insulating layer; and a metal wire attached to the catalyst substrate material.

  10. Carbon Monoxide (CO)

    Science.gov (United States)

    ... IAQ) Share Facebook Twitter Google+ Pinterest Contact Us Carbon Monoxide's Impact on Indoor Air Quality On this ... length of exposure. Top of Page Sources of Carbon Monoxide Sources of CO include: unvented kerosene and ...

  11. Soil Organic Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Soil organic carbon (SOC) is the carbon held within soil organic constituents (i.e., products produced as dead plants and animals decompose and the soil microbial...

  12. Biomass Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Biomass carbon includes carbon stored in above- and below-ground live plant components (such as leaf, branch, stem and root) as well as in standing and down dead...

  13. Trading forest carbon - OSU

    Science.gov (United States)

    Issues associate with trading carbon sequestered in forests are discussed. Scientific uncertainties associated with carbon measurement are discussed with respect to proposed accounting procedures. Major issues include: (1) Establishing baselines. (2) Determining additivity from f...

  14. SILICA SURFACED CARBON FIBERS.

    Science.gov (United States)

    carbon fibers . Several economical and simple processes were developed for obtaining research quantities of silica surfaced carbon filaments. Vat dipping processes were utilized to deposit an oxide such as silica onto the surface and into the micropores of available carbon or graphite base fibers. High performance composite materials were prepared with the surface treated carbon fibers and various resin matrices. The ablative characteristics of these composites were very promising and exhibited fewer limitations than either silica or...treated

  15. Protolytic carbon film technology

    Energy Technology Data Exchange (ETDEWEB)

    Renschler, C.L.; White, C.A.

    1996-04-01

    This paper presents a technique for the deposition of polyacrylonitrile (PAN) on virtually any surface allowing carbon film formation with only the caveat that the substrate must withstand carbonization temperatures of at least 600 degrees centigrade. The influence of processing conditions upon the structure and properties of the carbonized film is discussed. Electrical conductivity, microstructure, and morphology control are also described.

  16. Carbon Goes To…

    Science.gov (United States)

    Savasci, Funda

    2014-01-01

    The purposes of this activity are to help middle school students understand the carbon cycle and realize how human activities affect the carbon cycle. This activity consists of two parts. The first part of the activity focuses on the carbon cycle, especially before the Industrial Revolution, while the second part of the activity focuses on how…

  17. Carbon nanotube quantum dots

    NARCIS (Netherlands)

    Sapmaz, S.

    2006-01-01

    Low temperature electron transport measurements on individual single wall carbon nanotubes are described in this thesis. Carbon nanotubes are small hollow cylinders made entirely out of carbon atoms. At low temperatures (below ~10 K) finite length nanotubes form quantum dots. Because of its small si

  18. Carbon sequestration on Mars

    OpenAIRE

    Edwards, Christopher S.; Ehlmann, Bethany L.

    2015-01-01

    On Earth, carbon sequestration in geologic units plays an important role in the carbon cycle, scrubbing CO_2 from the atmosphere for long-term storage. While carbonate is identified in low abundances within the dust and soils of Mars, at

  19. Global Carbon Budget 2016

    NARCIS (Netherlands)

    Quéré, Le Corinne; Andrew, Robbie M.; Canadell, Josep G.; Sitch, Stephen; Korsbakken, Jan Ivar; Peters, Glen P.; Manning, Andrew C.; Boden, Thomas A.; Tans, Pieter P.; Houghton, Richard A.; Keeling, Ralph F.; Alin, Simone; Andrews, Oliver D.; Anthoni, Peter; Barbero, Leticia; Bopp, Laurent; Chevallier, Frédéric; Chini, Louise P.; Ciais, Philippe; Currie, Kim; Delire, Christine; Doney, Scott C.; Friedlingstein, Pierre; Gkritzalis, Thanos; Harris, Ian; Hauck, Judith; Haverd, Vanessa; Hoppema, Mario; Klein Goldewijk, Kees; Jain, Atul K.; Kato, Etsushi; Körtzinger, Arne; Landschützer, Peter; Lefèvre, Nathalie; Lenton, Andrew; Lienert, Sebastian; Lombardozzi, Danica; Melton, Joe R.; Metzl, Nicolas; Millero, Frank; Monteiro, Pedro M.S.; Munro, David R.; Nabel, Julia E.M.S.; Nakaoka, S.; O'Brien, Kevin; Olsen, Are; Omar, Abdirahman M.; Ono, Tsuneo; Pierrot, Denis; Poulter, Benjamin; Rödenbeck, Christian; Salisbury, Joe; Schuster, Ute; Schwinger, Jörg; Séférian, Roland; Skjelvan, Ingunn; Stocker, Benjamin D.; Sutton, Adrienne J.; Takahashi, Taro; Tian, Hanqin; Tilbrook, Bronte; Laan-Luijkx, van der Ingrid T.; Werf, van der Guido R.; Viovy, Nicolas; Walker, Anthony P.; Wiltshire, Andrew J.; Zaehle, Sönke

    2016-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project futur

  20. Preparation and photocatalytic activity of TiO2 by hydrolysis of titanium tetrachloride%四氯化钛水解法制备TiO2及光催化性能的研究

    Institute of Scientific and Technical Information of China (English)

    赵婷婷; 田鹏; 苏桂田; 吕烨; 毛媚; 张璐

    2012-01-01

    Titanium tetrachloride with inorganic salts as raw materials in the experiment, TiO2 was prepared by the hydrolyzation method in ( NH4 ) 3 SO4 -modified TiCl4 solution, The photocatalytic activity to a number of different types of catalysts were investigated using methyl blue as the organic in wastewater, Considering these factors such as the amount of ammoonium sulfate,. water-bath temperature 、 different solvents 、 calcination temperature and SO4 2-, which affect the ability of photocatalytic degradation, the mechanism was analyzed. We came to optimal conditions of preparing TiO2 powder i. e. Degradation of methylene blue for 120 minutes, when the mole ratio of TiCl4: ( NH4 )2SO4 = 1 : 2, the degradation rate was 83% ; when the water-bath temperature of 90 ℃, the degradation rate was 87% ; when cleaning solvent with ethanol, the degradation rate was 80% ; when the calcination temperature of 500 ℃ , the degradation rate was 85%. So the best conditions of preparing TiO2 powder were that the mole ratio of TiCl4 : (NH4) 2SO4 = 1 : 2, the water-bath temperature of 90 ℃, cleaning solvent with ethanol and the calcination temperature of 500 ℃.%实验以无机盐四氯化钛为原料,采用水解法用硫酸铵修饰四氯化钛溶液制得二氧化钛粉末.以甲基蓝模拟废水中的有机污染物,考察了硫酸铵的用量、水解温度、不同溶剂、锻烧温度以及硫酸根离子对光催化降解能力的影响,并对其机理进行了分析.得到了二氧化钛粉末适宜的制备工艺条件,降解甲基蓝120min,当四氯化钛与硫酸铵的物质的量摩尔比为1:2时光催化降解率达到83%、水解温度为90℃时光催化降解率达到87%、用无水乙醇溶剂进行清洗时光催化降解率达到80%、锻烧温度在500℃条件下光催化降解率达到85%.因此,采用水解法制备二氧化钛粉末最佳反应条件为:四氯化钛与硫酸铵的物质的量摩尔比为1:2、水解温度为90℃、用无水

  1. Amorphous iron (II) carbonate

    DEFF Research Database (Denmark)

    Sel, Ozlem; Radha, A.V.; Dideriksen, Knud;

    2012-01-01

    exothermic than that of amorphous calcium carbonate (ACC). This suggests that enthalpy of crystallization in carbonate systems is ionic-size controlled, which may have significant implications in a wide variety of conditions, including geological sequestration of anthropogenic carbon dioxide.......Abstract The synthesis, characterization and crystallization energetics of amorphous iron (II) carbonate (AFC) are reported. AFC may form as a precursor for siderite (FeCO3). The enthalpy of crystallization (DHcrys) of AFC is similar to that of amorphous magnesium carbonate (AMC) and more...

  2. Catalysts in syntheses of carbon and carbon precursors

    OpenAIRE

    Mochida, Isao; Yoon, Seong-Ho; Qiao, Wenming

    2006-01-01

    Carbon materials have been applied in different fields because of their unique performances. Naturally, the physical and chemical structures of carbon precursors and carbon materials decide their properties and applications. Catalysts play a very important role in the synthesis of carbon precursors and carbon materials by controlling the molecular and compositional chemistry at the transformation of organic substrates into carbon through carbonaceous intermediates. Carbon materials of high pe...

  3. Carbon dioxide sensor

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Prabir K. (Worthington, OH); Lee, Inhee (Columbus, OH); Akbar, Sheikh A. (Hilliard, OH)

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  4. Recovery studies for plutonium machining oil coolant

    Energy Technology Data Exchange (ETDEWEB)

    Navratil, J. D.; Baldwin, C. E.

    1977-04-27

    Lathe coolant oil, contaminated with plutonium and having a carbon tetrachloride diluent, is generated in plutonium machining areas at Rocky Flats. A research program was initiated to determine the nature of plutonium in this mixture of oil and carbon tetrachloride. Appropriate methods then could be developed to remove the plutonium and to recycle the oil and carbon tetrachloride. Studies showed that the mixtures of spent oil and carbon tetrachloride contained particulate plutonium and plutonium species that are soluble in water or in oil and carbon tetrachloride. The particulate plutonium was removed by filtration; the nonfilterable plutonium was removed by adsorption on various materials. Laboratory-scale tests indicated the lathe-coolant oil mixture could be separated by distilling the carbon tetrachloride to yield recyclable products.

  5. Graphitic Carbons and Biosignatures

    OpenAIRE

    Bernard, S.; Papineau, D

    2014-01-01

    The unambiguous identification of graphitic carbons as remains of life in ancient rocks is challenging because fossilized biogenic molecules are inevitably altered and degraded during diagenesis and metamorphism of the host rocks. Yet, recent studies have highlighted the possible preservation of biosignatures carried by some of the oldest graphitic carbons. Laboratory simulations are increasingly being used to better constrain the transformations of organic molecules into graphitic carbons in...

  6. Carbon Dioxide Absorbents

    Science.gov (United States)

    1950-05-17

    carbondioxide content of the solution was then determined. A gas mixture containing 2.6% carbon dioxide and 97.4% nitrogen was prepared in the...which carbon dioxide is removed by heat0 Since this step is usually carried out by "steam stripping ", that is, contacting the solution at its boiling...required to produce the steam required for stripping the carbon dioxide from the s olution. The method ueed in this investigation for determining the

  7. Carbon emissions Inventory Games

    OpenAIRE

    Al-Emadi, Eiman Ali

    2016-01-01

    Carbon emissions reduction has been the center of attention in many organizations during the past few decades. Many international entities developed rules and regulations to monitor and control carbon emissions especially under supply chain context. Furthermore, researchers investigated techniques and methods on how reduce carbon emissions under operational adjustment which can be done by cooperation or coordination. The main contribution of this thesis is to measure to what extend cooperatio...

  8. Animating the Carbon Cycle

    OpenAIRE

    2014-01-01

    Understanding the biogeochemical processes reg- ulating carbon cycling is central to mitigating atmospheric CO2 emissions. The role of living organisms has been accounted for, but the focus has traditionally been on contributions of plants and microbes. We develop the case that fully ‘‘animating’’ the carbon cycle requires broader consideration of the functional role of animals in mediating biogeochemical processes and quanti- fication of their effects on carbon storage and exchange among ter...

  9. Nanographene reinforced carbon/carbon composites

    Science.gov (United States)

    Bansal, Dhruv

    Carbon/Carbon Composites (CCC) are made of carbon reinforcement in carbon matrix and have high thermal stability and fatigue resistance. CCC are used in nose cones, heat shields and disc brakes of aircrafts due to their exceptional mechanical properties at high temperature. The manufacturing process of CCC involves a carbonization stage in which unwanted elements, except carbon, are eliminated from the polymer precursor. Carbonization results in the formation of voids and cracks due to the thermal mismatch between the reinforcement and the matrix and expulsion of volatiles from the polymer matrix. Thermal cracks and voids decrease the density and mechanical properties of the manufactured CCC. In this work, Nanographene Platelets (NGP) were explored as nanofillers to fill the voids/cracks and reduce thermal shrinkage in CCC. They were first compared with Vapor Grown Carbon Nanofibers (VGCNF) by dispersion of different concentrations (0.5wt%, 1.5wt%, 3wt%) in resole-type phenolic resin and were characterized to explore their effect on rheology, heat of reaction and wetting behavior. The dispersions were then cured to form nanocomposites and were characterized for morphology, flexure and thermal properties. Finally, NGP were introduced into the carbon/carboncomposites in two stages, first by spraying in different concentrations (0.5wt%, 1.5wt%, 3wt%, 5wt %) during the prepreg formation and later during densification by directly mixing in the corresponding densification mix. The manufactured NGP reinforced CCC were characterized for microstructure, porosity, bulk density and mechanical properties (Flexure and ILSS) which were further cross-checked by non-destructive techniques (vibration and ultrasonic). In this study, it was further found that at low concentration (≤ 1.5 wt%) NGP were more effective in increasing the heat of reaction and in decreasing the viscosity of the phenolic resin. The decrease in viscosity led to better wetting properties of NGP / phenolic

  10. CARBON DIOXIDE REDUCTION SYSTEM.

    Science.gov (United States)

    CARBON DIOXIDE , *SPACE FLIGHT, RESPIRATION, REDUCTION(CHEMISTRY), RESPIRATION, AEROSPACE MEDICINE, ELECTROLYSIS, INSTRUMENTATION, ELECTROLYTES, VOLTAGE, MANNED, YTTRIUM COMPOUNDS, ZIRCONIUM COMPOUNDS, NICKEL.

  11. Effect of Ginkgo biloba Leaves Aqueous Extract on Carbon

    Directory of Open Access Journals (Sweden)

    Hala A.H. Khattab

    2012-07-01

    Full Text Available Bachground: Oxidative stress plays a pivotal role in the pathogenesis and progression of various liver diseases. Ginkgo biloba leaves extract (GbE have been proved to be an effective antioxidant, thereby can contribute to the prevention and treatment of diseases associated with oxidative stress. The present study aimed to investigate the hepatoprotective effect of GbE on acute liver injury induced using carbon tetrachloride (CCl4 in rats. Material and Methods: Hepatotoxicity was induced in male rats by intraperitoneal (i.p injection of CCl4 1mL/ kg body weight (b.w. for every 72 h for 14 days, GbE was administered orally at a dose of 150 mg/kg b.w., daily started two weeks prior to CCl4 injection and continued until the end of the experiment. Results: CCl4 caused acute liver damage in rats, as evidenced by significant increase serum enzymes activities of aspartate and alanine aminotransferase (ALT & AST and alkaline phosphatase (ALP, and hepatic malondialdehyde (MDA, as well as significant decrease in weight gain percent, serum total protein (TP, high-density lipoprotein cholesterol (HDL-C, and hepatic reduced glutathione (GSH. Pretreatment with GbE prior to CCl4 injection elicited hepatoprotetcive activity by significant decreased the activities of liver enzymes and hepatic MDA, and significant increased the levels of TP, and hepatic GSH, as well as induced significant ameliorated in weight gain percent and lipid profile parameters as compared with CCl4 group. Histopathological examination of the liver tissues of CCl4 group represented the presence of hepatic necrosis associated with cells infiltration and vacuolar degeneration of hepatocytes, while the pretreatment with GbE overcome these changes, the majority of the cells tend to be normal.Conclusion: The present findings indicated that the hepatoprotective effect of GbE against CCl4-induced oxidative damage may be due to its potent antioxidant activity. Therefore, GbE could be of potential

  12. Microbially mediated mineral carbonation

    Science.gov (United States)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  13. Carbon Dioxide Fountain

    Science.gov (United States)

    Kang, Seong-Joo; Ryu, Eun-Hee

    2007-01-01

    This article presents the development of a carbon dioxide fountain. The advantages of the carbon dioxide fountain are that it is odorless and uses consumer chemicals. This experiment also is a nice visual experiment that allows students to see evidence of a gaseous reagent being consumed when a pressure sensor is available. (Contains 3 figures.)…

  14. De-carbonizingChina

    Institute of Scientific and Technical Information of China (English)

    zhou; Xiaoyan

    2013-01-01

    Innovation in the energy sector will pave the way for the country’slow-carbon future Although its per-capita emission is roughly on par with the world’s average, China is the world’s largest carbon dioxide emitter,

  15. Carbon for sensing devices

    CERN Document Server

    Tagliaferro, Alberto

    2015-01-01

    This book reveals why carbon is playing such an increasingly prominent role as a sensing material. The various steps that transform a raw material in a sensing device are thoroughly presented and critically discussed.  The authors deal with all aspects of carbon-based sensors, starting from the various hybridization and allotropes of carbon, with specific focus on micro and nanosized carbons (e.g., carbon nanotubes, graphene) and their growth processes. The discussion then moves to the role of functionalization and the different routes to achieve it. Finally, a number of sensing applications in various fields are presented, highlighting the connection with the basic properties of the various carbon allotropes.  Readers will benefit from this book’s bottom-up approach, which starts from the local bonding in carbon solids and ends with sensing applications, linking the local hybridization of carbon atoms and its modification by functionalization to specific device performance. This book is a must-have in th...

  16. China's carbon conundrum

    Science.gov (United States)

    Qi, Ye; Wu, Tong; He, Jiankun; King, David A.

    2013-07-01

    China's carbon dioxide emissions are rising fast. Yet, per capita, gross domestic product and energy use are only a fraction of their United States equivalents. With a growing urban middle class, the trend will continue, but there is progress on the path to a low-carbon economy.

  17. Global carbon budget 2014

    NARCIS (Netherlands)

    Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Peters, G. P.; Ciais, P.; Friedlingstein, P.; Jones, S. D.; Sitch, S.; Tans, P.; Arneth, A.; Boden, T. A.; Bopp, L.; Bozec, Y.; Canadell, J. G.; Chevallier, F.; Cosca, C. E.; Harris, I.; Hoppema, M.; Houghton, R. A.; House, J. I.; Jain, A.; Johannessen, T.; Kato, E.; Keeling, R. F.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landa, C. S.; Landschützer, P.; Lenton, A.; Lima, I. D.; Marland, G.; Mathis, J. T.; Metzl, N.; Nojiri, Y.; Olsen, A.; Ono, T.; Peters, W.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, P.; Rödenbeck, C.; Saito, S.; Salisbury, J. E.; Schuster, U.; Schwinger, J.; Séférian, R.; Segschneider, J.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Werf, G. R.; Viovy, N.; Wang, Y.-P.; Wanninkhof, R.; Wiltshire, A.; Zeng, N.

    2014-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we descr

  18. Global Carbon Budget 2015

    NARCIS (Netherlands)

    Quéré, Le C.; Moriarty, R.; Andrew, R.M.; Canadell, J.G.; Sitch, S.; Korsbakken, J.I.; Friedlingstein, P.; Peters, G.P.; Andres, R.J.; Boden, T.A.; Houghton, R.A.; House, J.I.; Keeling, R.F.; Tans, P.; Arneth, A.; Bakker, D.C.E.; Barbero, L.; Bopp, L.; Chang, J.; Chevallier, F.; Chini, L.P.; Ciais, P.; Fader, M.; Feely, R.A.; Gkritzalis, T.; Harris, I.; Hauck, J.; Ilyina, T.; Jain, A.K.; Kato, E.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landschützer, P.; Lauvset, S.K.; Lefèvre, N.; Lenton, A.; Lima, I.D.; Metzl, N.; Millero, F.; Munro, D.R.; Murata, A.; Nabel, J.E.M.S.; Nakaoka, S.; Nojiri, Y.; O'Brien, K.; Olsen, A.; Ono, T.; Pérez, F.F.; Pfeil, B.; Pierrot, D.; Poulter, B.; Rehder, G.; Rödenbeck, C.; Saito, S.; Schuster, U.; Schwinger, J.; Séférian, R.; Steinhoff, T.; Stocker, B.D.; Sutton, A.J.; Takahashi, T.; Tilbrook, B.; Laan-Luijkx, Van Der I.T.; Werf, Van Der G.R.; Heuven, Van S.; Vandemark, D.; Viovy, N.; Wiltshire, A.; Zaehle, S.; Zeng, N.

    2015-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we de

  19. Global carbon budget 2013

    NARCIS (Netherlands)

    Le Quéré, C.; Peters, G. P.; Andres, R. J.; Andrew, R. M.; Boden, T. A.; Ciais, P.; Friedlingstein, P.; Houghton, R. A.; Marland, G.; Moriarty, R.; Sitch, S.; Tans, P.; Arneth, A.; Arvanitis, A.; Bakker, D. C E; Bopp, L.; Canadell, J. G.; Chini, L. P.; Doney, S. C.; Harper, A.; Harris, I.; House, J. I.; Jain, A. K.; Jones, S. D.; Kato, E.; Keeling, R. F.; Klein Goldewijk, Kees; Körtzinger, A.; Koven, C.; Lefèvre, N.; Maignan, F.; Omar, A.; Ono, T.; Park, G. H.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, Piere; Rödenbeck, C.; Saito, S.; Schwinger, J.; Segschneider, J.; Stocker, B. D.; Takahashi, T.; Tilbrook, B.; Van Heuven, S.; Viovy, N.; Wanninkhof, R.; Wiltshire, A.; Zaehle, S.

    2014-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we descr

  20. Global Carbon Budget 2015

    NARCIS (Netherlands)

    Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Canadell, J. G.; Sitch, S.; Korsbakken, J. I.; Friedlingstein, P.; Peters, G. P.; Andres, R. J.; Boden, T. A.; Houghton, R. A.; House, J. I.; Keeling, R. F.; Tans, P.; Arneth, A.; Bakker, D. C. E.; Barbero, L.; Bopp, L.; Chang, J.; Chevallier, F.; Chini, L. P.; Ciais, P.; Fader, M.; Feely, R. A.; Gkritzalis, T.; Harris, I.; Hauck, J.; Ilyina, T.; Jain, A. K.; Kato, E.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landschützer, P.; Lauvset, S. K.; Lefèvre, N.; Lenton, A.; Lima, I. D.; Metzl, N.; Millero, F.; Munro, D. R.; Murata, A.; Nabel, J. E. M. S.; Nakaoka, S.; Nojiri, Y.; O'Brien, K.; Olsen, A.; Ono, T.; Pérez, F. F.; Pfeil, B.; Pierrot, D.; Poulter, B.; Rehder, G.; Rödenbeck, C.; Saito, S.; Schuster, U.; Schwinger, J.; Séférian, R.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Laan-Luijkx, I. T.; van der Werf, G. R.; van Heuven, S.; Vandemark, D.; Viovy, N.; Wiltshire, A.; Zaehle, S.; Zeng, N.

    2015-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we descr

  1. Fly ash carbon passivation

    Science.gov (United States)

    La Count, Robert B; Baltrus, John P; Kern, Douglas G

    2013-05-14

    A thermal method to passivate the carbon and/or other components in fly ash significantly decreases adsorption. The passivated carbon remains in the fly ash. Heating the fly ash to about 500 and 800 degrees C. under inert gas conditions sharply decreases the amount of surfactant adsorbed by the fly ash recovered after thermal treatment despite the fact that the carbon content remains in the fly ash. Using oxygen and inert gas mixtures, the present invention shows that a thermal treatment to about 500 degrees C. also sharply decreases the surfactant adsorption of the recovered fly ash even though most of the carbon remains intact. Also, thermal treatment to about 800 degrees C. under these same oxidative conditions shows a sharp decrease in surfactant adsorption of the recovered fly ash due to the fact that the carbon has been removed. This experiment simulates the various "carbon burnout" methods and is not a claim in this method. The present invention provides a thermal method of deactivating high carbon fly ash toward adsorption of AEAs while retaining the fly ash carbon. The fly ash can be used, for example, as a partial Portland cement replacement in air-entrained concrete, in conductive and other concretes, and for other applications.

  2. Carbon Dioxide and Climate.

    Science.gov (United States)

    Brewer, Peter G.

    1978-01-01

    The amount of carbon dioxide in the atmosphere is increasing at a rate that could cause significant warming of the Earth's climate in the not too distant future. Oceanographers are studying the role of the ocean as a source of carbon dioxide and as a sink for the gas. (Author/BB)

  3. COMMITTED TO CARBON REDUCTION

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Chinese efforts to lower carbon emissions through environmentally friendly means begin gaining momentum Efforts to curb carbon emissions continue to take shape as China adheres to its pledge for a brighter, greener future. More importantly, as environmental measures take hold and develop

  4. Global carbon budget 2014

    NARCIS (Netherlands)

    Quéré, Le C.; Peters, W.; Moriarty, R.; Friedlingstein, P.

    2015-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we descr

  5. Carbon Capture and Storage

    NARCIS (Netherlands)

    Benson, S.M.; Bennaceur, K.; Cook, P.; Davison, J.; Coninck, H. de; Farhat, K.; Ramirez, C.A.; Simbeck, D.; Surles, T.; Verma, P.; Wright, I.

    2012-01-01

    Emissions of carbon dioxide, the most important long-lived anthropogenic greenhouse gas, can be reduced by Carbon Capture and Storage (CCS). CCS involves the integration of four elements: CO 2 capture, compression of the CO2 from a gas to a liquid or a denser gas, transportation of pressurized CO 2

  6. Synthesis of hydrated lutetium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Song Liu [South China Univ. of Technology, Dept. of Applied Chemistry, Guangdong (China); Rong-jun Ma [Changsha Research Institute of Minig and Metallurgy, Hunan (China)

    1997-09-01

    Crystalline lutetium carbonate was synthesized for the corresponding chloride using ammonium bicarbonate as precipitant. The chemical analyses suggest that the synthesized lutetium carbonate is a hydrated basic carbonate or oxycarbonate. The X-ray powder diffraction data are presented. The IR data for the compound show the presence of two different carbonate groups. There is no stable intermediate carbonate in the process of thermal decomposition of the lutetium carbonate. (au) 15 refs.

  7. Carbon dioxide conversion over carbon-based nanocatalysts.

    Science.gov (United States)

    Khavarian, Mehrnoush; Chai, Siang-Piao; Mohamed, Abdul Rahman

    2013-07-01

    The utilization of carbon dioxide for the production of valuable chemicals via catalysts is one of the efficient ways to mitigate the greenhouse gases in the atmosphere. It is known that the carbon dioxide conversion and product yields are still low even if the reaction is operated at high pressure and temperature. The carbon dioxide utilization and conversion provides many challenges in exploring new concepts and opportunities for development of unique catalysts for the purpose of activating the carbon dioxide molecules. In this paper, the role of carbon-based nanocatalysts in the hydrogenation of carbon dioxide and direct synthesis of dimethyl carbonate from carbon dioxide and methanol are reviewed. The current catalytic results obtained with different carbon-based nanocatalysts systems are presented and how these materials contribute to the carbon dioxide conversion is explained. In addition, different strategies and preparation methods of nanometallic catalysts on various carbon supports are described to optimize the dispersion of metal nanoparticles and catalytic activity.

  8. Preliminary hepatoprotective activity of Jigarine Cl on carbon tetra chloride induced hepatic damage in rats

    Directory of Open Access Journals (Sweden)

    Muhammad Ahmed

    2014-02-01

    Full Text Available Jigarine CL  is an herbal preparation of Hamdard laboratories waqf Pakistan that has been used as hepatoprotective agent. In this study, the protective effects of Jigarine CL  against liver damage were evaluated in carbon tetrachloride (CCl4-induced chronic hepatotoxicity in rats. Sprague-Dawley (SD rats were divided in to four groups (I, II, III, IV. Groups I received olive oil 10ml/kg p.o served as control and group II  and III were orally fed with Jigarine CL (20ml/kg for 14 consecutive days while Groups IV were orally fed with saline. After the last dose of jigarine CL and saline group III and IV received a single dose of CCl4 (0.3 ml/kg body weight in a 20% olive oil was injected intraperitoneally 30 min after the last dose of Barrisal and the animals were starved for 24 h. The degree of hepatic-protection was measured using biochemical parameters (serum glutamate oxaloacetate transaminase (SGOT and serum glutamate pyruvate transaminase (SGPT and Bilirubin and histopathology. Data obtained from results were compared using student’s t-test. The results showed that the treatment of Jigarine CL  significantly lowered the CCl4-induced serum levels of hepatic enzyme markers (GOT, GPT and total bilirubin indicated hepatoprotective effect of the Jigarine CL. Histopathological examination of liver sections confirmed that, pre-treatment with Jigarine CL  decreased the degree of hepatic damage induced by CCl4. The  significant reversal of the biochemical and histological changes induced by CCl4treatment in rats, indicating promising hepatoprotective activity of Jigarine CL in rats.

  9. Small diameter carbon nanopipettes

    Science.gov (United States)

    Singhal, Riju; Bhattacharyya, Sayan; Orynbayeva, Zulfiya; Vitol, Elina; Friedman, Gary; Gogotsi, Yury

    2010-01-01

    Nanoscale multifunctional carbon probes facilitate cellular studies due to their small size, which makes it possible to interrogate organelles within living cells in a minimally invasive fashion. However, connecting nanotubes to macroscopic devices and constructing an integrated system for the purpose of fluid and electrical signal transfer is challenging, as is often the case with nanoscale components. We describe a non-catalytic chemical vapor deposition based method for batch fabrication of integrated multifunctional carbon nanopipettes (CNPs) with tip diameters much smaller (10-30 nm) than previously reported (200 nm and above) and approaching those observed for multiwalled carbon nanotubes. This eliminates the need for complicated attachment/assembly of nanotubes into nanofluidic devices. Variable tip geometries and structures were obtained by controlled deposition of carbon inside and outside quartz pipettes. We have shown that the capillary length and gas flow rate have a marked effect on the carbon deposition. This gives us a flexible protocol, useful for growing carbon layers of different thicknesses at selective locations on a glass pipette to yield a large variety of cellular probes in bulk quantities. The CNPs possess an open channel for fluid transfer with the carbon deposited inside at 875 °C behaving like an amorphous semiconductor. Vacuum annealing of the CNP tips at temperatures up to 2000 °C yields graphitic carbon structures with an increase in conductivity of two orders of magnitude. Penetration of the integrated carbon nanoprobes into cells was shown to produce minimal Ca2+ signals, fast recovery of basal Ca2+ levels and no adverse activation of the cellular metabolism during interrogation times as long as 0.5-1 h.

  10. Carbon Superatom Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Canning, A. [Cray Research, PSE, EPFL, 1015 Lausanne (Switzerland); Canning, A.; Galli, G. [Institut Romand de Recherche Numerique en Physique des Materiaux (IRRMA), IN-Ecublens, 1015 Lausanne (Switzerland); Kim, J. [Department of Physics, The Ohio State University, Columbus, Ohio 43210 (United States)

    1997-06-01

    We report on quantum molecular dynamics simulations of C{sub 28} deposition on a semiconducting surface. Our results show that under certain deposition conditions C{sub 28} {close_quote}s act as building blocks on a nanometer scale to form a thin film of nearly defect-free molecules. The C{sub 28} {close_quote}s behave as carbon superatoms, with the majority of them being threefold or fourfold coordinated, similar to carbon atoms in amorphous systems. The microscopic structure of the deposited film supports recent suggestions about the stability of a new form of carbon, the hyperdiamond solid. {copyright} {ital 1997} {ital The American Physical Society}

  11. Production of carbon nanotubes

    Science.gov (United States)

    Journet, C.; Bernier, P.

    Carbon nanostructures such as single-walled and multi-walled nanotubes (SWNTs and MWNTs) or graphitic polyhedral nanoparticles can be produced using various methods. Most of them are based on the sublimation of carbon under an inert atmosphere, such as the electric arc discharge process, the laser ablation method, or the solar technique. But chemical methods can also be used to synthesize these kinds of carbon materials: the catalytic decomposition of hydrocarbons, the production by electrolysis, the heat treatment of a polymer, the low temperature solid pyrolysis, or the in situ catalysis.

  12. Carbon Disulfide (CS2) Interference in Glucose Metabolism from Unconventional Oil and Gas Extraction and Processing Emissions.

    Science.gov (United States)

    Rich, Alisa L; Patel, Jay T; Al-Angari, Samiah S

    2016-01-01

    Carbon disulfide (CS2) has been historically associated with the manufacturing of rayon, cellophane, and carbon tetrachloride production. This study is one of the first to identify elevated atmospheric levels of CS2 above national background levels and its mechanisms to dysregulate normal glucose metabolism. Interference in glucose metabolism can indirectly cause other complications (diabetes, neurodegenerative disease, and retinopathy), which may be preventable if proper precautions are taken. Rich et al found CS2 and 12 associated sulfide compounds present in the atmosphere in residential areas where unconventional shale oil and gas extraction and processing operations were occurring. Ambient atmospheric concentrations of CS2 ranged from 0.7 parts per billion by volume (ppbv) to 103 ppbv over a continuous 24-hour monitoring period. One-hour ambient atmospheric concentrations ranged from 3.4 ppbv to 504.6 ppbv. Using the U.S. Environmental Protection Agency Urban Air Toxic Monitoring Program study as a baseline comparison for atmospheric CS2 concentrations found in this study, it was determined that CS2 atmospheric levels were consistently elevated in areas where unconventional oil and gas extraction and processing occurred. The mechanisms by which CS2 interferes in normal glucose metabolism by dysregulation of the tryptophan metabolism pathway are presented in this study. The literature review found an increased potential for alteration of normal glucose metabolism in viscose rayon occupational workers exposed to CS2. Occupational workers in the energy extraction industry exposed to CS2 and other sulfide compounds may have an increased potential for glucose metabolism interference, which has been an indicator for diabetogenic effect and other related health impacts. The recommendation of this study is for implementation of regular monitoring of blood glucose levels in CS2-exposed populations as a preventative health measure.

  13. Authigenic Carbonate and the History of the Global Carbon Cycle

    Science.gov (United States)

    Schrag, Daniel P.; Higgins, John. A.; Macdonald, Francis A.; Johnston, David T.

    2013-02-01

    We present a framework for interpreting the carbon isotopic composition of sedimentary rocks, which in turn requires a fundamental reinterpretation of the carbon cycle and redox budgets over Earth's history. We propose that authigenic carbonate, produced in sediment pore fluids during early diagenesis, has played a major role in the carbon cycle in the past. This sink constitutes a minor component of the carbon isotope mass balance under the modern, high levels of atmospheric oxygen but was much larger in times of low atmospheric O2 or widespread marine anoxia. Waxing and waning of a global authigenic carbonate sink helps to explain extreme carbon isotope variations in the Proterozoic, Paleozoic, and Triassic.

  14. Carbon Stock and Carbon Cycle of Wetland Ecosystem

    Institute of Scientific and Technical Information of China (English)

    Zhangquan; ZENG; Canming; ZHANG; Jiao; LI; Nan; YANG; Xihao; LI; Yandong; NIU; Zijian; WU

    2014-01-01

    Wetland ecosystem is an essential ecosystem in the world. Its organic carbon stock and carbon cycle are important basis of global carbon cycle researches and also major contents of global climate change researches. Researches have shown that wetland protection and restoration can promote carbon accumulation and reduce emission of greenhouse gases. This paper discussed influence of carbon stock and carbon balance of wetland ecosystem and emission of greenhouse gases,as well as the relationship between wetland and global climate changes. Finally,it made prospect on researches about carbon cycle of Dongting Lake.

  15. A novel carbon fiber based porous carbon monolith

    Energy Technology Data Exchange (ETDEWEB)

    Burchell, T.D.; Klett, J.W.; Weaver, C.E.

    1995-06-01

    A novel porous carbon material based on carbon fibers has been developed. The material, when activated, develops a significant micro- or mesopore volume dependent upon the carbon fiber type utilized (isotropic pitch or polyacrylonitrile). The materials will find applications in the field of fluid separations or as a catalyst support. Here, the manufacture and characterization of our porous carbon monoliths are described. A novel adsorbent carbon composite material has been developed comprising carbon fibers and a binder. The material, called carbon fiber composite molecular sieve (CFCMS), was developed through a joint research program between Oak Ridge National Laboratory (ORNL) and the University of Kentucky, Center for Applied Energy Research (UKCAER).

  16. High performance carbon-carbon composites

    Indian Academy of Sciences (India)

    Lalit M Manocha

    2003-02-01

    Carbon-carbon composites rank first among ceramic composite materials with a spectrum of properties and applications in various sectors. These composites are made of fibres in various directions and carbonaceous polymers and hydrocarbons as matrix precursors. Their density and properties depend on the type and volume fraction of reinforcement, matrix precursor used and end heat treatment temperature. Composites made with thermosetting resins as matrix precursors possess low densities (1.55–1.75 g/cm3) and well-distributed microporosity whereas those made with pitch as the matrix precursor, after densification exhibit densities of 1.8–2.0 g/cm3 with some mesopores, and those made by the CVD technique with hydrocarbon gases, possess intermediate densities and matrices with close porosities. The former (resin-based) composites exhibit high flexural strength, low toughness and low thermal conductivity, whereas the latter (pitch- and CVD-based) can be made with very high thermal conductivity (400–700 W/MK) in the fibre direction. Carbon-carbon composites are used in a variety of sectors requiring high mechanical properties at elevated temperatures, good frictional properties for brake pads in high speed vehicles or high thermal conductivity for thermal management applications. However, for extended life applications, these composites need to be protected against oxidation either through matrix modification with Si, Zr, Hf etc. or by multilayer oxidation protection coatings consisting of SiC, silica, zircon etc.

  17. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of Consumer Products 2012 Annual Estimates OCTOBER 13, 2015 Incidents, Deaths, and In-Depth Investigations Associated with Non-Fire ...

  18. [Particle therapy: carbon ions].

    Science.gov (United States)

    Pommier, Pascal; Hu, Yi; Baron, Marie-Hélène; Chapet, Olivier; Balosso, Jacques

    2010-07-01

    Carbon ion therapy is an innovative radiation therapy. It has been first proposed in the forties by Robert Wilson, however the first dedicated centres for human care have been build up only recently in Japan and Germany. The interest of carbon ion is twofold: 1) the very sharp targeting of the tumour with the so called spread out Bragg peak that delivers most of the beam energy in the tumour and nothing beyond it, sparing very efficiently the healthy tissues; 2) the higher relative biological efficiency compared to X rays or protons, able to kill radioresistant tumour cells. Both properties make carbon ions the elective therapy for non resectable radioresistant tumours loco-regionally threatening. The technical and clinical experience accumulated during the recent decades is summarized in this paper along with a detailed presentation of the elective indications. A short comparison between conventional radiotherapy and hadrontherapy is proposed for the indications which are considered as priority for carbon ions.

  19. Global carbon budget 2014

    NARCIS (Netherlands)

    Le Quéré, C.; Moriarty, R.; Andrew, R. M.; Peters, G. P.; Ciais, P.; Friedlingstein, P.; Jones, S. D.; Sitch, S.; Tans, P.; Arneth, A.; Boden, T. A.; Bopp, L.; Bozec, Y.; Canadell, J. G.; Chevallier, F.; Cosca, C. E.; Harris, I.; Hoppema, M.; Houghton, R. A.; House, J. I.; Jain, A.; Johannessen, T.; Kato, E.; Keeling, R. F.; Kitidis, V.; Klein Goldewijk, K.; Koven, C.; Landa, C. S.; Landschützer, P.; Lenton, A.; Lima, I. D.; Marland, G.; Mathis, J. T.; Metzl, N.; Nojiri, Y.; Olsen, A.; Ono, T.; Peters, W.; Pfeil, B.; Poulter, B.; Raupach, M. R.; Regnier, P.; Rödenbeck, C.; Saito, S.; Salisbury, J. E.; Schuster, U.; Schwinger, J.; Séférian, R.; Segschneider, J.; Steinhoff, T.; Stocker, B. D.; Sutton, A. J.; Takahashi, T.; Tilbrook, B.; van der Werf, G. R.; Viovy, N.; Wang, Y.-P.; Wanninkhof, R.; Wiltshire, A.; Zeng, N.

    2015-01-01

    Accurate assessment of anthropogenic carbon dioxide (CO2)emissions and their redistribution among the atmosphere, ocean, andterrestrial biosphere is important to better understand the globalcarbon cycle, support the development of climate policies, and projectfuture climate change. Here we describe

  20. Total Ecosystem Carbon Stock

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Total ecosystem carbon includes above- and below-ground live plant components (such as leaf, branch, stem and root), dead biomass (such as standing dead wood, down...

  1. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Community Outreach Resource Center Toy Recall Statistics CO Poster Contest Pool Safely Business & Manufacturing Business & Manufacturing Business ... Featured Resources CPSC announces winners of carbon monoxide poster contest Video View the blog Clues You Can ...

  2. Carbon Monoxide Information Center

    Medline Plus

    Full Text Available ... Unites States die every year from accidental non-fire related CO poisoning associated with consumer products, including ... CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths Associated with the Use of ...

  3. Carbon Monoxide Information Center

    Science.gov (United States)

    ... and Criminal Penalties Federal Court Orders & Decisions Research & Statistics Research & Statistics Technical Reports Injury Statistics NEISS Injury Data ... On Safety Blogs: CO Safety More CO Blogs Research & Statistics JANUARY 07, 2016 Non-Fire Carbon Monoxide Deaths ...

  4. Carbon partitioning in photosynthesis.

    Science.gov (United States)

    Melis, Anastasios

    2013-06-01

    The work seeks to raise awareness of a fundamental problem that impacts the renewable generation of fuels and chemicals via (photo)synthetic biology. At issue is regulation of the endogenous cellular carbon partitioning between different biosynthetic pathways, over which the living cell exerts stringent control. The regulation of carbon partitioning in photosynthesis is not understood. In plants, microalgae and cyanobacteria, methods need be devised to alter photosynthetic carbon partitioning between the sugar, terpenoid, and fatty acid biosynthetic pathways, to lower the prevalence of sugar biosynthesis and correspondingly upregulate terpenoid and fatty acid hydrocarbons production in the cell. Insight from unusual but naturally occurring carbon-partitioning processes can help in the design of blueprints for improved photosynthetic fuels and chemicals production.

  5. Carbon Monoxide Nonattainment Areas

    Data.gov (United States)

    U.S. Environmental Protection Agency — This data layer identifies areas in the U.S. where air pollution levels have not met the National Ambient Air Quality Standards (NAAQS) for Carbon Monoxide and have...

  6. Applications for alliform carbon

    Energy Technology Data Exchange (ETDEWEB)

    Gogotsi, Yury; Mochalin, Vadym; McDonough, IV, John Kenneth; Simon, Patrice; Taberna, Pierre Louis

    2017-02-21

    This invention relates to novel applications for alliform carbon, useful in conductors and energy storage devices, including electrical double layer capacitor devices and articles incorporating such conductors and devices. Said alliform carbon particles are in the range of 2 to about 20 percent by weight, relative to the weight of the entire electrode. Said novel applications include supercapacitors and associated electrode devices, batteries, bandages and wound healing, and thin-film devices, including display devices.

  7. Carbon footprint of thermowood

    OpenAIRE

    Nordlund, Teemu

    2013-01-01

    Purpose of this Bachelor’s Thesis was to evaluate the carbon footprint of thermally modified wood and its manufacturing process and transportation cycle for several different ThermoWood producer. Research included the whole production cycle from harvesting raw wood to ThermoWood transportation in destination area. Carbon dioxide emissions from these areas were determined and calculated for every ThermoWood producer at first hand. Calculations were based on the PAS 2050:2011, which is ...

  8. Method for synthesizing carbon nanotubes

    Science.gov (United States)

    Fan, Hongyou

    2012-09-04

    A method for preparing a precursor solution for synthesis of carbon nanomaterials, where a polar solvent is added to at least one block copolymer and at least one carbohydrate compound, and the precursor solution is processed using a self-assembly process and subsequent heating to form nanoporous carbon films, porous carbon nanotubes, and porous carbon nanoparticles.

  9. Nano-Carbons as Theranostics

    Directory of Open Access Journals (Sweden)

    Zhuang Liu, Xing-Jie Liang

    2012-01-01

    Full Text Available Nano-carbons, including fullerenes, carbon nanoparticles, carbon nanotubes, graphene, and nano-diamonds, are an important class of nanostructures attracting tremendous interests in the past two decades. In this special issue, seven review articles and research reports are collected, to summarize and present the latest progress in the exploration of various nano-carbons for theranostic applications.

  10. Carbon based prosthetic devices

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Carroll, D.W.; Barbero, R.S.; Archuleta, T. [Los Alamos National Lab., NM (US); Klawitter, J.J.; Ogilvie, W.; Strzepa, P. [Ascension Orthopedics (US); Cook, S.D. [Tulane Univ., New Orleans, LA (US). School of Medicine

    1998-12-31

    This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project objective was to evaluate the use of carbon/carbon-fiber-reinforced composites for use in endoprosthetic devices. The application of these materials for the metacarpophalangeal (MP) joints of the hand was investigated. Issues concerning mechanical properties, bone fixation, biocompatibility, and wear are discussed. A system consisting of fiber reinforced materials with a pyrolytic carbon matrix and diamond-like, carbon-coated wear surfaces was developed. Processes were developed for the chemical vapor infiltration (CVI) of pyrolytic carbon into porous fiber preforms with the ability to tailor the outer porosity of the device to provide a surface for bone in-growth. A method for coating diamond-like carbon (DLC) on the articulating surface by plasma-assisted chemical vapor deposition (CVD) was developed. Preliminary results on mechanical properties of the composite system are discussed and initial biocompatibility studies were performed.

  11. Aspects of carbon dioxide utilization

    Energy Technology Data Exchange (ETDEWEB)

    Omae, Iwao [Omae Research Laboratories, 335-23 Mizuno, Sayama, Saitama 350-1317 (Japan)

    2006-06-30

    Carbon dioxide reacts with hydrogen, alcohols, acetals, epoxides, amines, carbon-carbon unsaturated compounds, etc. in supercritical carbon dioxide or in other solvents in the presence of metal compounds as catalysts. The products of these reactions are formic acid, formic acid esters, formamides, methanol, dimethyl carbonate, alkylene carbonates, carbamic acid esters, lactones, carboxylic acids, polycarbonate (bisphenol-based engineering polymer), aliphatic polycarbonates, etc. Especially, the productions of formic acid, formic acid methyl ester and dimethylformamide with a ruthenium catalyst; dimethyl carbonate and urethanes with a dialkyltin catalyst; 2-pyrone with a nickel-phosphine catalyst; diphenyl carbonate with a lead phenoxide catalyst; the alternating copolymerization of carbon dioxide and epoxides with a zinc catalyst has attracted attentions as the industrial utilizations of carbon dioxide. The further development of these production processes is expected. (author)

  12. Organic modification of carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The organic modification of carbon nanotubes is a novel research field being developed recently. In this article, the history and newest progress of organic modification of carbon nanotubes are reviewed from two aspects:organic covalent modification and organic noncovalent modification of carbon nanotubes. The preparation and properties of organic modified carbon nanotubes are discussed in detail. In addition, the prospective development of organic modification of carbon nanotubes is suggested.

  13. Implications of carbon dust emission for terrestrail carbon cycling and carbon accounting

    Science.gov (United States)

    Wind erosion preferentially removes the finest carbon- and nutrient-rich soil fractions, and consequently its role may be significant within terrestrial carbon (C) cycles. However, the impacts of wind erosion on soil organic carbon (SOC) redistribution are not considered in most carbon cycle models,...

  14. Measurement of carbon capture efficiency and stored carbon leakage

    Science.gov (United States)

    Keeling, Ralph F.; Dubey, Manvendra K.

    2013-01-29

    Data representative of a measured carbon dioxide (CO.sub.2) concentration and of a measured oxygen (O.sub.2) concentration at a measurement location can be used to determine whether the measured carbon dioxide concentration at the measurement location is elevated relative to a baseline carbon dioxide concentration due to escape of carbon dioxide from a source associated with a carbon capture and storage process. Optionally, the data can be used to quantify a carbon dioxide concentration increase at the first location that is attributable to escape of carbon dioxide from the source and to calculate a rate of escape of carbon dioxide from the source by executing a model of gas-phase transport using at least the first carbon dioxide concentration increase. Related systems, methods, and articles of manufacture are also described.

  15. Microbially mediated carbon mineralization: Geoengineering a carbon-neutral mine

    Science.gov (United States)

    Power, I. M.; McCutcheon, J.; Harrison, A. L.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2013-12-01

    Ultramafic and mafic mine tailings are a potentially valuable feedstock for carbon mineralization, affording the mining industry an opportunity to completely offset their carbon emissions. Passive carbon mineralization has previously been documented at the abandoned Clinton Creek asbestos mine, and the active Diavik diamond mine and Mount Keith nickel mine, yet the majority of tailings remain unreacted. Examples of microbe-carbonate interactions at each mine suggest that biological pathways could be harnessed to promote carbon mineralization. In suitable environmental conditions, microbes can mediate geochemical processes to accelerate mineral dissolution, increase the supply of carbon dioxide (CO2), and induce carbonate precipitation, all of which may accelerate carbon mineralization. Tailings mineralogy and the availability of a CO2 point source are key considerations in designing tailings storage facilities (TSF) for optimizing carbon mineralization. We evaluate the efficacy of acceleration strategies including bioleaching, biologically induced carbonate precipitation, and heterotrophic oxidation of waste organics, as well as abiotic strategies including enhancing passive carbonation through modifying tailings management practices and use of CO2 point sources (Fig. 1). With the aim of developing carbon-neutral mines, implementation of carbon mineralization strategies into TSF design will be driven by economic incentives and public pressure for environmental sustainability in the mining industry. Figure 1. Schematic illustrating geoengineered scenarios for carbon mineralization of ultramafic mine tailings. Scenarios A and B are based on non-point and point sources of CO2, respectively.

  16. Terrestrial Carbon Cycle Variability

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2, temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1), and

  17. Carbon fuel particles used in direct carbon conversion fuel cells

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

    A system for preparing particulate carbon fuel and using the particulate carbon fuel in a fuel cell. Carbon particles are finely divided. The finely dividing carbon particles are introduced into the fuel cell. A gas containing oxygen is introduced into the fuel cell. The finely divided carbon particles are exposed to carbonate salts, or to molten NaOH or KOH or LiOH or mixtures of NaOH or KOH or LiOH, or to mixed hydroxides, or to alkali and alkaline earth nitrates.

  18. Carbon Concentration of Austenite

    Directory of Open Access Journals (Sweden)

    Z. Ławrynowicz

    2007-07-01

    Full Text Available The investigation was carried out to examine the influence of temperature and times of austempering process on the maximum extend towhich the bainite reaction can proceed and the carbon content in retained austenite. It should be noted that a small percentage change in theaustenite carbon content can have a significant effect on the subsequent austempering reaction changing the volume fraction of the phasespresent and hence, the resulting mechanical properties. Specimens were prepared from an unalloyed ductile cast iron, austenitised at 950oCfor 60 minutes and austempered by the conventional single-step austempering process at four temperatures between BS and MS, eg., 250,300, 350 and 400oC. The samples were austempered at these temperatures for 15, 30, 60, 120 and 240 minutes and finally quenched toambient temperature. Volume fractions of retained austenite and carbon concentration in the residual austenite have been observed byusing X-ray diffraction. Additionally, carbon concentration in the residual austenite was calculated using volume fraction data of austeniteand a model developed by Bhadeshia based on the McLellan and Dunn quasi-chemical thermodynamic model. The comparison ofexperimental data with the T0, T0' and Ae3' phase boundaries suggests the likely mechanism of bainite reaction in cast iron is displacive rather than diffusional. The carbon concentration in retained austenite demonstrates that at the end of bainite reaction the microstructure must consist of not only ausferrite but additionally precipitated carbides.

  19. Flexible Carbon Aerogels

    Directory of Open Access Journals (Sweden)

    Marina Schwan

    2016-09-01

    Full Text Available Carbon aerogels are highly porous materials with a large inner surface area. Due to their high electrical conductivity they are excellent electrode materials in supercapacitors. Their brittleness, however, imposes certain limitations in terms of applicability. In that context, novel carbon aerogels with varying degree of flexibility have been developed. These highly porous, light aerogels are characterized by a high surface area and possess pore structures in the micrometer range, allowing for a reversible deformation of the aerogel network. A high ratio of pore size to particle size was found to be crucial for high flexibility. For dynamic microstructural analysis, compression tests were performed in-situ within a scanning electron microscope allowing us to directly visualize the microstructural flexibility of an aerogel. The flexible carbon aerogels were found to withstand between 15% and 30% of uniaxial compression in a reversible fashion. These findings might stimulate further research and new application fields directed towards flexible supercapacitors and batteries.

  20. Carbon nanotubes for supercapacitor.

    Science.gov (United States)

    Pan, Hui; Li, Jianyi; Feng, Yuanping

    2010-01-05

    As an electrical energy storage device, supercapacitor finds attractive applications in consumer electronic products and alternative power source due to its higher energy density, fast discharge/charge time, low level of heating, safety, long-term operation stability, and no disposable parts. This work reviews the recent development of supercapacitor based on carbon nanotubes (CNTs) and their composites. The purpose is to give a comprehensive understanding of the advantages and disadvantages of carbon nanotubes-related supercapacitor materials and to find ways for the improvement in the performance of supercapacitor. We first discussed the effects of physical and chemical properties of pure carbon nanotubes, including size, purity, defect, shape, functionalization, and annealing, on the supercapacitance. The composites, including CNTs/oxide and CNTs/polymer, were further discussed to enhance the supercapacitance and keep the stability of the supercapacitor by optimally engineering the composition, particle size, and coverage.

  1. Carbon Nanotubes for Supercapacitor

    Directory of Open Access Journals (Sweden)

    Li Jianyi

    2010-01-01

    Full Text Available Abstract As an electrical energy storage device, supercapacitor finds attractive applications in consumer electronic products and alternative power source due to its higher energy density, fast discharge/charge time, low level of heating, safety, long-term operation stability, and no disposable parts. This work reviews the recent development of supercapacitor based on carbon nanotubes (CNTs and their composites. The purpose is to give a comprehensive understanding of the advantages and disadvantages of carbon nanotubes-related supercapacitor materials and to find ways for the improvement in the performance of supercapacitor. We first discussed the effects of physical and chemical properties of pure carbon nanotubes, including size, purity, defect, shape, functionalization, and annealing, on the supercapacitance. The composites, including CNTs/oxide and CNTs/polymer, were further discussed to enhance the supercapacitance and keep the stability of the supercapacitor by optimally engineering the composition, particle size, and coverage.

  2. Superconductivity in carbon nanomaterials

    Science.gov (United States)

    Dlugon, Katarzyna

    The purpose of this thesis is to explain the phenomenon of superconductivity in carbon nanomaterials such as graphene, fullerenes and carbon nanotubes. In the introductory chapter, there is a description of superconductivity and how it occurs at critical temperature (Tc) that is characteristic and different to every superconducting material. The discovery of superconductivity in mercury in 1911 by Dutch physicist Heike Kamerlingh Onnes is also mentioned. Different types of superconductors, type I and type II, low and high temperatures superconductors, as well as the BCS theory that was developed in 1957 by Bardeen, Cooper, and Schrieffer, are also described in detail. The BCS theory explains how Cooper's pairs are formed and how they are responsible for the superconducting properties of many materials. The following chapters explain superconductivity in doped fullerenes, graphene and carbon nanotubes, respectively. There is a thorough explanation followed by many examples of different types of carbon nanomaterials in which small changes in chemical structure cause significant changes in superconducting properties. The goal of this research was not only to take into consideration well known carbon based superconductors but also to search for the newest available materials such as the fullerene nanowhiskers discovered quite recently. There is also a presentation of fairly new ideas about inducing superconductivity in a monolayer of graphene which is more challenging than inducing superconductivity in graphite by simply intercalating metal atoms between its graphene sheets. An effort has been taken to look for any available information about carbon nanomaterials that have the potential to superconduct at room temperature, mainly because discovery of such materials would be a real revolution in the modern world, although no such materials have been discovered yet.

  3. Porosity destruction in carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Ehrenberg, S.N. [Statoil, Stavanger (Norway)

    2006-01-15

    The important thing to understand about carbonate diagenesis is not how porosity is created, but how it is destroyed. Detailed core observations from two deeply-buried carbonate platform successions (the Finnmark platform, offshore north Norway; and the Khuff Formation, offshore Iran) show that in both cases most vertical porosity variation can be accounted for by only two or three factors, namely: (1) stylolite frequency, (2) proportion of argillaceous beds, and (3) anhydrite cement. The spatial distribution of these factors is determined by the depositional distribution of clay minerals (important for localizing chemical compaction) and the occurrence of hypersaline depositional conditions and associated brine reflux (important for localizing anhydrite precipitation and dolomitisation). However, the intensity of chemical compaction and consequent porosity loss in adjacent beds by carbonate cementation also depend upon thermal exposure (temperature as a function of time). Evidence from the Finnmark platform and other examples indicate that the stratigraphic distribution of early-formed dolomite is also important for porosity preservation during burial, but this factor is not apparent in the Khuff dataset. Insofar as the Finnmark and Khuff platforms can be regarded as representative of carbonate reservoirs in general, recognition of the above porosity-controlling factors may provide the basis for general models predicting carbonate reservoir potential both locally (reservoir-model scale) and regionally (exploration-scale). Distributions of clay, anhydrite, and dolomitization should be predictable from stratigraphic architecture, whereas variations in thermal exposure can be mapped from basin analysis. In the present examples at least, factors that do not need to be considered include eogenetic carbonate cementation and dissolution, depositional facies (other than aspects related to clay and anhydrite content), and mesogenetic leaching to create late secondary

  4. Inkjet Printing of Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Ryan P. Tortorich

    2013-07-01

    Full Text Available In an attempt to give a brief introduction to carbon nanotube inkjet printing, this review paper discusses the issues that come along with preparing and printing carbon nanotube ink. Carbon nanotube inkjet printing is relatively new, but it has great potential for broad applications in flexible and printable electronics, transparent electrodes, electronic sensors, and so on due to its low cost and the extraordinary properties of carbon nanotubes. In addition to the formulation of carbon nanotube ink and its printing technologies, recent progress and achievements of carbon nanotube inkjet printing are reviewed in detail with brief discussion on the future outlook of the technology.

  5. Nanomechanics of carbon nanotubes.

    Science.gov (United States)

    Kis, Andras; Zettl, Alex

    2008-05-13

    Some of the most important potential applications of carbon nanotubes are related to their mechanical properties. Stiff sp2 bonds result in a Young's modulus close to that of diamond, while the relatively weak van der Waals interaction between the graphitic shells acts as a form of lubrication. Previous characterization of the mechanical properties of nanotubes includes a rich variety of experiments involving mechanical deformation of nanotubes using scanning probe microscopes. These results have led to promising prototypes of nanoelectromechanical devices such as high-performance nanomotors, switches and oscillators based on carbon nanotubes.

  6. Ultrahard carbon nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    SIEGAL,MICHAEL P.; TALLANT,DAVID R.; PROVENCIO,PAULA P.; OVERMYER,DONALD L.; SIMPSON,REGINA L.; MARTINEZ-MIRANDA,L.J.

    2000-01-27

    Modest thermal annealing to 600 C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5--10%. The authors report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approximately} 15% due to the development of the nanocomposite structure.

  7. Ultrahard carbon nanocomposite films

    Energy Technology Data Exchange (ETDEWEB)

    Siegal, M. P. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Tallant, D. R. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Provencio, P. N. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Overmyer, D. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Simpson, R. L. [Sandia National Laboratories, Albuquerque, New Mexico 87185-1421 (United States); Martinez-Miranda, L. J. [Department of Materials and Nuclear Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2000-05-22

    Modest thermal annealing to 600 degree sign C of diamondlike amorphous-carbon (a-C) films grown at room temperature results in the formation of carbon nanocomposites with hardness similar to diamond. These nanocomposite films consist of nanometer-sized regions of high density a-C embedded in an a-C matrix with a reduced density of 5%-10%. We report on the evolution of density and bonding topologies as a function of annealing temperature. Despite a decrease in density, film hardness actually increases {approx}15% due to the development of the nanocomposite structure. (c) 2000 American Institute of Physics.

  8. Carbon-carbon mirrors for exoatmospheric and space applications

    Science.gov (United States)

    Krumweide, Duane E.; Wonacott, Gary D.; Woida, Patrick M.; Woida, Rigel Q.; Shih, Wei

    2007-09-01

    The cost and leadtime associated with beryllium has forced the MDA and other defense agencies to look for alternative materials with similar structural and thermal properties. The use of carbon-carbon material, specifically in optical components has been demonstrated analytically in prior SBIR work at San Diego Composites. Carbon-carbon material was chosen for its low in-plane and through-thickness CTE (athermal design), high specific stiffness, near-zero coefficient of moisture expansion, availability of material (specifically c-c honeycomb for lightweight substrates), and compatibility with silicon monoxide (SiO) and silicon dioxide (SiO II) coatings. Subsequent development work has produced shaped carbon-carbon sandwich substrates which have been ground, polished, coated and figured using traditional optical processing. Further development has also been done on machined monolithic carbon-carbon mirror substrates which have also been processed using standard optical finishing techniques.

  9. Atomic and Molecular Layer Deposition for Enhanced Lithium Ion Battery Electrodes and Development of Conductive Metal Oxide/Carbon Composites

    Science.gov (United States)

    Travis, Jonathan

    The performance and safety of lithium-ion batteries (LIBs) are dependent on interfacial processes at the positive and negative electrodes. For example, the surface layers that form on cathodes and anodes are known to affect the kinetics and capacity of LIBs. Interfacial reactions between the electrolyte and the electrodes are also known to initiate electrolyte combustion during thermal runaway events that compromise battery safety. Atomic layer deposition (ALD) and molecular layer deposition (MLD) are thin film deposition techniques based on sequential, self-limiting surface reactions. ALD and MLD can deposit ultrathin and conformal films on high aspect ratio and porous substrates such as composite particulate electrodes in lithium-ion batteries. The effects of electrode surface modification via ALD and MLD are studied using a variety of techniques. It was found that sub-nm thick coatings of Al2O 3 deposited via ALD have beneficial effects on the stability of LIB anodes and cathodes. These same Al2O3 ALD films were found to improve the safety of graphite based anodes through prevention of exothermic solid electrolyte interface (SEI) degradation at elevated temperatures. Ultrathin and conformal metal alkoxide polymer films known as "metalcones" were grown utilizing MLD techniques with trimethylaluminum (TMA) or titanium tetrachloride (TiCl4) and organic diols or triols, such as ethylene glycol (EG), glycerol (GL) or hydroquinone (HQ), as the reactants. Pyrolysis of these metalcone films under inert gas conditions led to the development of conductive metal oxide/carbon composites. The composites were found to contain sp2 carbon using micro-Raman spectroscopy in the pyrolyzed films with pyrolysis temperatures ≥ 600°C. Four point probe measurements demonstrated that the graphitic sp2 carbon domains in the metalcone films grown using GL and HQ led to significant conductivity. The pyrolysis of conformal MLD films to obtain conductive metal oxide/carbon composite films

  10. Simulations of phenol adsorption on activated carbon and carbon black

    OpenAIRE

    Prosenjak, Claudia; Valente Nabais, Joao; Laginhas, Carlos; Carrott, Peter; Carrott, Manuela

    2010-01-01

    We use grand canonical Monte Carlo and molecular dynamics simulations to study the adsorption of phenol on carbon materials. Activated carbon is modelled by pore size distributions based on DFT methods; carbon black is represented by a single carbon slab with varying percentages of surface atoms removed. GCMC results for the adsorption from the corresponding gas phase gave reasonable agreement with experimental adsorption results. MD simulations, that studied the influence of the presence of ...

  11. Method for production of carbon nanofiber mat or carbon paper

    Energy Technology Data Exchange (ETDEWEB)

    Naskar, Amit K.

    2015-08-04

    Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.

  12. Catalytic graphitization of carbon/carbon composites by lanthanum oxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Can; LU Guimin; SUN Ze; YU Jianguo

    2012-01-01

    Graphitized carbon/carbon composites were prepared by the process of catalytic graphitization with the rare-earth catalyst,lanthanum oxide (La2O3),in order to increase the degree of graphitization and reduce the electrical resistivity.The modified coal tar pitch and coal-based needle coke were used as carbon source,and a small amount of La2O3 was added to catalyze the graphitization of the disordered carbon materials.The effects of La2O3 catalyst on the graphitization degree and microstructure oftbe carbon/carbon composites were investigated by X-ray diffraction,scanning electron microscopy,and Raman spectroscopy.The results showed that La2O3 promoted the formation of more perfect and larger crystallites,and improved the electrical/mechanical properties of carbon/carbon composites.Carbon/carbon composites with a lower electrical resistivity (7.0 μΩ·m) could be prepared when adding 5 wt.% La2O3 powder with heating treatment at 2800 ℃.The catalytic effect of La2O3 for the graphitization of carbon/carbon composites was analyzed.

  13. Australian carbon dust emission: a carbon accounting omission?

    Science.gov (United States)

    Erosion preferentially removes the finest carbon- and nutrient-rich soil fractions, and consequently its role may be significant within terrestrial carbon (C) cycles. However, the impacts of wind erosion on soil organic carbon redistribution are not considered in most SOC models, or within the Austr...

  14. Carbon nanotube solar cells.

    Directory of Open Access Journals (Sweden)

    Colin Klinger

    Full Text Available We present proof-of-concept all-carbon solar cells. They are made of a photoactive side of predominantly semiconducting nanotubes for photoconversion and a counter electrode made of a natural mixture of carbon nanotubes or graphite, connected by a liquid electrolyte through a redox reaction. The cells do not require rare source materials such as In or Pt, nor high-grade semiconductor processing equipment, do not rely on dye for photoconversion and therefore do not bleach, and are easy to fabricate using a spray-paint technique. We observe that cells with a lower concentration of carbon nanotubes on the active semiconducting electrode perform better than cells with a higher concentration of nanotubes. This effect is contrary to the expectation that a larger number of nanotubes would lead to more photoconversion and therefore more power generation. We attribute this to the presence of metallic nanotubes that provide a short for photo-excited electrons, bypassing the load. We demonstrate optimization strategies that improve cell efficiency by orders of magnitude. Once it is possible to make semiconducting-only carbon nanotube films, that may provide the greatest efficiency improvement.

  15. Closing carbon cycles

    NARCIS (Netherlands)

    Patel, Martin

    2001-01-01

    Fossil fuels are used as raw materials for the manufacture of synthetic organic materials, e.g. plastics, fibres, synthetic rubber, paints, solvents, fertilisers, surfactants, lubricants and bitumen. Since fossil carbon is embodied in these products they may be particularly relevant to climate ch

  16. City Carbon Footprint Networks

    Directory of Open Access Journals (Sweden)

    Guangwu Chen

    2016-07-01

    Full Text Available Progressive cities worldwide have demonstrated political leadership by initiating meaningful strategies and actions to tackle climate change. However, the lack of knowledge concerning embodied greenhouse gas (GHG emissions of cities has hampered effective mitigation. We analyse trans-boundary GHG emission transfers between five Australian cities and their trading partners, with embodied emission flows broken down into major economic sectors. We examine intercity carbon footprint (CF networks and disclose a hierarchy of responsibility for emissions between cities and regions. Allocations of emissions to households, businesses and government and the carbon efficiency of expenditure have been analysed to inform mitigation policies. Our findings indicate that final demand in the five largest cities in Australia accounts for more than half of the nation’s CF. City households are responsible for about two thirds of the cities’ CFs; the rest can be attributed to government and business consumption and investment. The city network flows highlight that over half of emissions embodied in imports (EEI to the five cities occur overseas. However, a hierarchy of GHG emissions reveals that overseas regions also outsource emissions to Australian cities such as Perth. We finally discuss the implications of our findings on carbon neutrality, low-carbon city concepts and strategies and allocation of subnational GHG responsibility.

  17. Calcium carbonate overdose

    Science.gov (United States)

    Calcium carbonate is not very poisonous. Recovery is quite likely. But, long-term overuse is more serious than a single overdose, because it can cause kidney damage. Few people die from an antacid overdose. Keep all medicines in child-proof bottles and out ...

  18. Carbon nanotubes for microelectronics?

    Science.gov (United States)

    Graham, Andrew P; Duesberg, Georg S; Seidel, Robert V; Liebau, Maik; Unger, Eugen; Pamler, Werner; Kreupl, Franz; Hoenlein, Wolfgang

    2005-04-01

    Despite all prophecies of its end, silicon-based microelectronics still follows Moore's Law and continues to develop rapidly. However, the inherent physical limits will eventually be reached. Carbon nanotubes offer the potential for further miniaturization as long as it is possible to selectively deposit them with defined properties.

  19. From Carbon to Buckypaper

    Indian Academy of Sciences (India)

    Surabhi Potnis

    2017-03-01

    This article aims to highlight the amazing properties and potentialuses of the more recently developed allotropes of carbonsuch as carbon nanotubes, graphene, fullerene, and buckypaper.This is an area offering wide opportunity for research,especially due to the multidisciplinary nature of applications.

  20. Carbon sinks in temperate forests

    NARCIS (Netherlands)

    Martin, P.H.; Nabuurs, G.J.; Aubinet, M.; Karjalainen, T.; Vine, E.L.; Kinsman, J.; Heath, L.S.

    2001-01-01

    In addition to being scientifically exciting, commercially important, and environmentally essential, temperate forests have also become a key diplomatic item in international climate negotiations as potential sinks for carbon. This review presents the methods used to estimate carbon sequestration, i

  1. ROE Carbon Storage - Percent Change

    Data.gov (United States)

    U.S. Environmental Protection Agency — This polygon dataset depicts the percentage change in the amount of carbon stored in forests in counties across the United States, based on the difference in carbon...

  2. Where is mantle's carbon?

    Science.gov (United States)

    Oganov, A. R.; Ono, S.; Ma, Y.

    2008-12-01

    Due to the strongly reducing conditions (the presence of metallic iron was suggested both by experiments [1] and theory [2]), diamond was believed to be the main host of carbon through most of the lower mantle [3]. We showed [4] that cementite Fe3C is another good candidate to be the main host of "reduced" carbon in the mantle, reinforcing an earlier hypothesis [5]. The fate of "oxidised" carbon (in subducted slabs) is of particular importance - if carbonates decompose producing fluid CO2, this would have important implications for the chemistry and rheology of the mantle. Knowledge of crystal structures and phase diagrams of carbonates is crucial here. The high-pressure structures of CaCO3 were predicted [6] and subsequently verified by experiments. For MgCO3, Isshiki et al. [7] found a new phase above 110 GPa, and several attempts were made to solve it [8,9]. Here [4], using an evolutionary algorithm for crystal structure prediction [10], we show that there are two post-magnesite phases at mantle-relevant pressure range, one stable at 82-138 GPa, and the other from 138 GPa to ~160 GPa. Both are based on threefold rings of CO4-tetrahedra and are more favourable than all previously proposed structures. We show that through most of the P-T conditions of the mantle, MgCO3 is the major host of oxidized carbon in the Earth. We predict the possibility of CO2 release at the very bottom of the mantle (in SiO2-rich basaltic part of subducted slabs), which could enhance partial melting of rocks and be related to the geodynamical differences between the Earth and Venus. 1.Frost D.J., Liebske C., Langenhorst F., McCammon C.A., Tronnes R.G., Rubie D.C. (2004). Experimental evidence for the existence of iron-rich metal in the Earth's lower mantle. Nature 428, 409-412. 2.Zhang F., Oganov A.R. (2006). Valence and spin states of iron impurities in mantle-forming silicates. Earth Planet. Sci. Lett. 249, 436-443. 3.Luth R.W. (1999). Carbon and carbonates in the mantle. In: Mantle

  3. Templated Growth of Carbon Nanotubes

    Science.gov (United States)

    Siochik Emilie J. (Inventor)

    2007-01-01

    A method of growing carbon nanotubes uses a synthesized mesoporous si lica template with approximately cylindrical pores being formed there in. The surfaces of the pores are coated with a carbon nanotube precu rsor, and the template with the surfaces of the pores so-coated is th en heated until the carbon nanotube precursor in each pore is convert ed to a carbon nanotube.

  4. Boron nitride converted carbon fiber

    Science.gov (United States)

    Rousseas, Michael; Mickelson, William; Zettl, Alexander K.

    2016-04-05

    This disclosure provides systems, methods, and apparatus related to boron nitride converted carbon fiber. In one aspect, a method may include the operations of providing boron oxide and carbon fiber, heating the boron oxide to melt the boron oxide and heating the carbon fiber, mixing a nitrogen-containing gas with boron oxide vapor from molten boron oxide, and converting at least a portion of the carbon fiber to boron nitride.

  5. Managing woody bamboos for carbon farming and carbon trading

    Directory of Open Access Journals (Sweden)

    Arun Jyoti Nath

    2015-01-01

    Full Text Available Research on identifying cost-effective managed ecosystems that can substantially remove atmospheric carbon-dioxide (CO2 while providing essential societal benefits has gained momentum since the Kyoto Protocol of 1997. Carbon farming allows farmers and investors to generate tradable carbon offsets from farmlands and forestry projects through carbon trading. Carbon trading is pertinent to climate negotiations by decelerating the climate change phenomenon. Thus, the objective of this article is to describe the potential of woody bamboos in biomass carbon storage and as an option for carbon farming and carbon trading. Bamboo is an important agroforestry and forest plant managed and used by the rural communities in several countries of the Asia-Pacific region for generating diverse economic and socio-environmental needs. Mean carbon storage and sequestration rate in woody bamboos range from 30–121 Mg ha−1 and 6–13 Mg ha−1  yr−1, respectively. Bamboo has vigorous growth, with completion of the growth cycle between 120 and 150 days. Because of its rapid biomass accumulation and effective fixation of CO2, it has a high carbon sequestration capacity. Over and above the high biomass carbon storage, bamboo also has a high net primary productivity (12–26 Mg ha−1  yr−1 even with regular selective harvesting, thus making it a standing carbon stock and a living ecosystem that continues to grow. Despite its high potential in carbon storage and sequestration and its important role in livelihood of millions of rural poor’s worldwide, prospects of bamboo ecosystems in CDM (Clean Development Mechanism and REDD (Reduced Emission from Deforestation and Forest Degradation schemes remain to be explored. Thus, there is an urgent need to recognize ecosystem services that woody bamboo provides for well-being of rural communities and nature conservancy. Present synthesis suggests that bamboo offers tremendous opportunity for carbon farming and

  6. Carbon nanotube junctions and devices

    NARCIS (Netherlands)

    Postma, H.W.Ch.

    2001-01-01

    In this thesis Postma presents transport experiments performed on individual single-wall carbon nanotubes. Carbon nanotubes are molecules entirely made of carbon atoms. The electronic properties are determined by the exact symmetry of the nanotube lattice, resulting in either metallic or semiconduct

  7. Apparatus for producing carbon-coated nanoparticles and carbon nanospheres

    Energy Technology Data Exchange (ETDEWEB)

    Perry, W. Lee; Weigle, John C.; Phillips, Jonathan

    2015-10-20

    An apparatus for producing carbon-coated nano- or micron-scale particles comprising a container for entraining particles in an aerosol gas, providing an inlet for carbon-containing gas, providing an inlet for plasma gas, a proximate torch for mixing the aerosol gas, the carbon-containing gas, and the plasma gas, bombarding the mixed gases with microwaves, and providing a collection device for gathering the resulting carbon-coated nano- or micron-scale particles. Also disclosed is a method and apparatus for making hollow carbon nano- or micro-scale spheres.

  8. Graphene oxide assisted hydrothermal carbonization of carbon hydrates.

    Science.gov (United States)

    Krishnan, Deepti; Raidongia, Kalyan; Shao, Jiaojing; Huang, Jiaxing

    2014-01-28

    Hydrothermal carbonization (HTC) of biomass such as glucose and cellulose typically produces micrometer-sized carbon spheres that are insulating. Adding a very small amount of Graphene oxide (GO) to glucose (e.g., 1:800 weight ratio) can significantly alter the morphology of its HTC product, resulting in more conductive carbon materials with higher degree of carbonization. At low mass loading level of GO, HTC treatment results in dispersed carbon platelets of tens of nanometers in thickness, while at high mass loading levels, free-standing carbon monoliths are obtained. Control experiments with other carbon materials such as graphite, carbon nanotubes, carbon black, and reduced GO show that only GO has significant effect in promoting HTC conversion, likely due to its good water processability, amphiphilicity, and two-dimensional structure that may help to template the initially carbonized materials. GO offers an additional advantage in that its graphene product can act as an in situ heating element to enable further carbonization of the HTC products very rapidly upon microwave irradiation. Similar effect of GO is also observed for the HTC treatment of cellulose.

  9. Erosion of soil organic carbon: implications for carbon sequestration

    Science.gov (United States)

    Van Oost, Kristof; Van Hemelryck, Hendrik; Harden, Jennifer W.; McPherson, B.J.; Sundquist, E.T.

    2009-01-01

    Agricultural activities have substantially increased rates of soil erosion and deposition, and these processes have a significant impact on carbon (C) mineralization and burial. Here, we present a synthesis of erosion effects on carbon dynamics and discuss the implications of soil erosion for carbon sequestration strategies. We demonstrate that for a range of data-based parameters from the literature, soil erosion results in increased C storage onto land, an effect that is heterogeneous on the landscape and is variable on various timescales. We argue that the magnitude of the erosion term and soil carbon residence time, both strongly influenced by soil management, largely control the strength of the erosion-induced sink. In order to evaluate fully the effects of soil management strategies that promote carbon sequestration, a full carbon account must be made that considers the impact of erosion-enhanced disequilibrium between carbon inputs and decomposition, including effects on net primary productivity and decomposition rates.

  10. 27 CFR 21.127 - Shellac (refined).

    Science.gov (United States)

    2010-04-01

    ... Section 21.127 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... A—5 ml of phenol dissolved in 10 ml of carbon tetrachloride. Solution B—1 ml of bromine dissolved in 4 ml of carbon tetrachloride. To the residue obtained above add 2 ml of Solution A and transfer...

  11. CARBON DIOXIDE SEPARATION BY SELECTIVE PERMEATION.

    Science.gov (United States)

    CARBON DIOXIDE , SEPARATION), (*PERMEABILITY, CARBON DIOXIDE ), POROUS MATERIALS, SILICON COMPOUNDS, RUBBER, SELECTION, ADSORPTION, TEMPERATURE, PRESSURE, POLYMERS, FILMS, PLASTICS, MEMBRANES, HUMIDITY.

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

    Institute of Scientific and Technical Information of China (English)

    Brahma Naidu Parimi; Ramgopal Mopuri; Balaji Meriga

    2014-01-01

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

  13. Carbon Nanotube Biosensors

    Directory of Open Access Journals (Sweden)

    Carmen-Mihaela eTilmaciu

    2015-10-01

    Full Text Available Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular Carbon Nanotubes (CNTs can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we will describe their structural and physical properties, discuss functionalization and cellular uptake, biocompatibility and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers.

  14. Growing carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Yoshinori Ando

    2004-10-01

    Full Text Available The discovery of ‘fullerenes’ added a new dimension to the knowledge of carbon science1; and the subsequent discovery of ‘carbon nanotubes’ (CNTs, the elongated fullerene added a new dimension to the knowledge of technology2;. Today, ‘nanotechnology’ is a hot topic attracting scientists, industrialists, journalists, governments, and even the general public. Nanotechnology is the creation of functional materials, devices, and systems through control of matter on the nanometer scale and the exploitation of novel phenomena and properties of matter (physical, chemical, biological, electrical, etc. at that length scale. CNTs are supposed to be a key component of nanotechnology. Almost every week a new potential application of CNTs is identified, stimulating scientists to peep into this tiny tube with ever increasing curiosity.

  15. Carbon materials for supercapacitors

    Science.gov (United States)

    Gao, Yang

    As an important energy storage device, electrochemical supercapacitors or ultracapacitors fill the gap between conventional dielectric capacitors and batteries in terms of specific energy and power. Although supercapacitors have been used in electric vehicles, digital communication instruments, and pulsed lasers, further improvement of supercapacitor performance is highly needed to enhance the energy density without significantly losing the power density. Additionally, the conventional supercapacitors use rigid packages and liquid electrolytes, which limit applications in transparent and flexible electronics. To address these challenges, the research efforts in this dissertation mainly focused on: 1) improvement of the energy density of carbon nanoonions by chemical activation; 2) laser-assisted activation of carbon nanotubes for improved energy density; 3) fabrication of flexible solid-state supercapacitors based on nanocarbon and manganese dioxide (MnO2) hybrid electrodes; and 4) investigation of the electrochemical performance of graphene as transparent and flexible supercapacitor electrodes.

  16. Carbon Lorenz Curves

    Energy Technology Data Exchange (ETDEWEB)

    Groot, L. [Utrecht University, Utrecht School of Economics, Janskerkhof 12, 3512 BL Utrecht (Netherlands)

    2008-11-15

    The purpose of this paper is twofold. First, it exhibits that standard tools in the measurement of income inequality, such as the Lorenz curve and the Gini-index, can successfully be applied to the issues of inequality measurement of carbon emissions and the equity of abatement policies across countries. These tools allow policy-makers and the general public to grasp at a single glance the impact of conventional distribution rules such as equal caps or grandfathering, or more sophisticated ones, on the distribution of greenhouse gas emissions. Second, using the Samuelson rule for the optimal provision of a public good, the Pareto-optimal distribution of carbon emissions is compared with the distribution that follows if countries follow Nash-Cournot abatement strategies. It is shown that the Pareto-optimal distribution under the Samuelson rule can be approximated by the equal cap division, represented by the diagonal in the Lorenz curve diagram.

  17. Carbon neutron star atmospheres

    CERN Document Server

    Suleimanov, V F; Pavlov, G G; Werner, K

    2013-01-01

    The accuracy of measuring the basic parameters of neutron stars is limited in particular by uncertainties in chemical composition of their atmospheres. For example, atmospheres of thermally - emitting neutron stars in supernova remnants might have exotic chemical compositions, and for one of them, the neutron star in CasA, a pure carbon atmosphere has recently been suggested by Ho & Heinke (2009). To test such a composition for other similar sources, a publicly available detailed grid of carbon model atmosphere spectra is needed. We have computed such a grid using the standard LTE approximation and assuming that the magnetic field does not exceed 10^8 G. The opacities and pressure ionization effects are calculated using the Opacity Project approach. We describe the properties of our models and investigate the impact of the adopted assumptions and approximations on the emergent spectra.

  18. Properties of amorphous carbon

    CERN Document Server

    2003-01-01

    Amorphous carbon has a wide range of properties that are primarily controlled by the different bond hydridisations possible in such materials. This allows for the growth of an extensive range of thin films that can be tailored for specific applications. Films can range from those with high transparency and are hard diamond-like, through to those which are opaque, soft and graphitic-like. Films with a high degree of sp3 bonding giving the diamond-like properties are used widely by industry for hard coatings. Application areas including field emission cathodes, MEMS, electronic devices, medical and optical coatings are now close to market. Experts in amorphous carbon have been drawn together to produce this comprehensive commentary on the current state and future prospects of this highly functional material.

  19. Carbon nanotube biosensors

    Science.gov (United States)

    Tîlmaciu, Carmen-Mihaela; Morris, May C.

    2015-01-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular, carbon nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical, and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites, or disease biomarkers. Here we provide a comprehensive review on these carbon nanostructures, in which we describe their structural and physical properties, functionalization and cellular uptake, biocompatibility, and toxicity issues. We further review historical developments in the field of biosensors, and describe the different types of biosensors which have been developed over time, with specific focus on CNT-conjugates engineered for biosensing applications, and in particular detection of cancer biomarkers. PMID:26579509

  20. Increasing the Tensile Property of Unidirectional Carbon/Carbon Composites by Grafting Carbon Nanotubes onto Carbon Fibers by Electrophoretic Deposition

    Institute of Scientific and Technical Information of China (English)

    Qiang Song; Kezhi Li; Hejun Li; Qiangang Fu

    2013-01-01

    Although in-situ growing carbon nanotubes (CNTs) on carbon fibers could greatly increase the matrix-dominated mechanical properties of carbon/carbon composites (C/Cs),it always decreased the tensile strength of carbon fibers.In this work,CNTs were introduced into unidirectional carbon fiber (CF) preforms by electrophoretic deposition (EPD) and they were used to reinforce C/Cs.Effects of the content of CNTs introduced by EPD on tensile property of unidirectional C/Cs were investigated.Results demonstrated that EPD could be used as a simple and efficient method to fabricate carbon nanotube reinforced C/Cs (CNT-C/Cs) with excellent tensile strength,which pays a meaningful way to maximize the global performance of CNT-C/Cs.

  1. Digital carbonate rock physics

    Science.gov (United States)

    Saenger, Erik H.; Vialle, Stephanie; Lebedev, Maxim; Uribe, David; Osorno, Maria; Duda, Mandy; Steeb, Holger

    2016-08-01

    Modern estimation of rock properties combines imaging with advanced numerical simulations, an approach known as digital rock physics (DRP). In this paper we suggest a specific segmentation procedure of X-ray micro-computed tomography data with two different resolutions in the µm range for two sets of carbonate rock samples. These carbonates were already characterized in detail in a previous laboratory study which we complement with nanoindentation experiments (for local elastic properties). In a first step a non-local mean filter is applied to the raw image data. We then apply different thresholds to identify pores and solid phases. Because of a non-neglectable amount of unresolved microporosity (micritic phase) we also define intermediate threshold values for distinct phases. Based on this segmentation we determine porosity-dependent values for effective P- and S-wave velocities as well as for the intrinsic permeability. For effective velocities we confirm an observed two-phase trend reported in another study using a different carbonate data set. As an upscaling approach we use this two-phase trend as an effective medium approach to estimate the porosity-dependent elastic properties of the micritic phase for the low-resolution images. The porosity measured in the laboratory is then used to predict the effective rock properties from the observed trends for a comparison with experimental data. The two-phase trend can be regarded as an upper bound for elastic properties; the use of the two-phase trend for low-resolution images led to a good estimate for a lower bound of effective elastic properties. Anisotropy is observed for some of the considered subvolumes, but seems to be insignificant for the analysed rocks at the DRP scale. Because of the complexity of carbonates we suggest using DRP as a complementary tool for rock characterization in addition to classical experimental methods.

  2. Carbon Materials Research

    Science.gov (United States)

    2006-08-01

    electrodes, high temperature molds, rocket nozzles and exit cones, tires , ink, nuclear reactors and fuel particles, filters, prosthetics, batteries and...carbon would be highly oriented pyrolytic graphite (HOPG), which is formed by depositing one atom at a time on a surface utilizing the pyrolysis of a...Moreover, it is well known that during pyrolysis , mesophase converts into a matrix that is very anisotropic. The formation of onion-like “sheaths

  3. Carbon nanotube network varactor

    Science.gov (United States)

    Generalov, A. A.; Anoshkin, I. V.; Erdmanis, M.; Lioubtchenko, D. V.; Ovchinnikov, V.; Nasibulin, A. G.; Räisänen, A. V.

    2015-01-01

    Microelectromechanical system (MEMS) varactors based on a freestanding layer of single-walled carbon nanotube (SWCNT) films were designed, fabricated and tested. The freestanding SWCNT film was employed as a movable upper patch in the parallel plate capacitor of the MEMS. The measurements of the SWCNT varactors show very high tunability, nearly 100%, of the capacitance with a low actuation voltage of 10 V. The functionality of the varactor is improved by implementing a flexible nanocellulose aerogel filling.

  4. Carbon Nanotube Thermoelectric Coolers

    Science.gov (United States)

    2015-02-06

    conductance. Inside thecentral section of the carbon nanotube, we obtained an impressive Peltier cooling 57 K down from the liquid nitrogentemperature. 15... trapped charges or dipoles) that occur either at the interface between the CNT and the gate dielectric (interface defects) or at some position within... liquid nitrogen temperature 77T  K up to hot 134 8T  K, or decreases from 77T  K down to about cold 20 6T  K, thus evidencing a strong

  5. Carbon nanotube biosensors

    OpenAIRE

    Tîlmaciu, Carmen-Mihaela; Morris, May C

    2015-01-01

    Nanomaterials possess unique features which make them particularly attractive for biosensing applications. In particular, carbon nanotubes (CNTs) can serve as scaffolds for immobilization of biomolecules at their surface, and combine several exceptional physical, chemical, electrical, and optical characteristics properties which make them one of the best suited materials for the transduction of signals associated with the recognition of analytes, metabolites, or disease biomarkers. Here we pr...

  6. Improving Carbon Fixation Pathways

    OpenAIRE

    Ducat, Daniel C.; Silver, Pamela A

    2012-01-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing...

  7. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  8. Studies of Carbon Nanotubes

    Science.gov (United States)

    Caneba, Gerard T.

    2005-01-01

    The fellowship experience for this summer for 2004 pertains to carbon nanotube coatings for various space-related applications. They involve the following projects: (a) EMI protection films from HiPco-polymers, and (b) Thermal protection nanosilica materials. EMI protection films are targeted to be eventually applied onto casings of laptop computers. These coatings are composites of electrically-conductive SWNTs and compatible polymers. The substrate polymer will be polycarbonate, since computer housings are typically made of carbon composites of this type of polymer. A new experimental copolymer was used last year to generate electrically-conductive and thermal films with HiPco at 50/50 wt/wt composition. This will be one of the possible formulations. Reference films will be base polycarbonate and neat HiPco onto polycarbonate films. Other coating materials that will be tried will be based on HiPco composites with commercial enamels (polyurethane, acrylic, polyester), which could be compatible with the polycarbonate substrate. Nanosilica fibers are planned for possible use as thermal protection tiles on the shuttle orbiter. Right now, microscale silica is used. Going to the nanoscale will increase the surface-volume-per-unit-area of radiative heat dissipation. Nanoscale carbon fibers/nanotubes can be used as templates for the generation of nanosilica. A sol-gel operation is employed for this purpose.

  9. Securing tropical forest carbon

    DEFF Research Database (Denmark)

    Scharlemann, Jörn P. W.; Kapos, Valerie; Campbell, Alison;

    2010-01-01

    Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate...... that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation...... in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important...

  10. Carbon taxes and India

    Energy Technology Data Exchange (ETDEWEB)

    Fisher-Vanden, K.A.; Pitcher, H.M.; Edmonds, J.A.; Kim, S.H. [Pacific Northwest Lab., Richland, WA (United States); Shukla, P.R. [Indian Institute of Management, Ahmedabad (India)

    1994-07-01

    Using the Indian module of the Second Generation Model 9SGM, we explore a reference case and three scenarios in which greenhouse gas emissions were controlled. Two alternative policy instruments (carbon taxes and tradable permits) were analyzed to determine comparative costs of stabilizing emissions at (1) 1990 levels (the 1 X case), (2) two times the 1990 levels (the 2X case), and (3) three times the 1990 levels (the 3X case). The analysis takes into account India`s rapidly growing population and the abundance of coal and biomass relative to other fuels. We also explore the impacts of a global tradable permits market to stabilize global carbon emissions on the Indian economy under the following two emissions allowance allocation methods: (1) {open_quotes}Grandfathered emissions{close_quotes}: emissions allowances are allocated based on 1990 emissions. (2) {open_quotes}Equal per capita emissions{close_quotes}: emissions allowances are allocated based on share of global population. Tradable permits represent a lower cost method to stabilize Indian emissions than carbon taxes, i.e., global action would benefit India more than independent actions.

  11. A carbon sink pathway increases carbon productivity in cyanobacteria.

    Science.gov (United States)

    Oliver, John W K; Atsumi, Shota

    2015-05-01

    The burning of fossil reserves, and subsequent release of carbon into the atmosphere is depleting the supply of carbon-based molecules used for synthetic materials including plastics, oils, medicines, and glues. To provide for future society, innovations are needed for the conversion of waste carbon (CO2) into organic carbon useful for materials. Chemical production directly from photosynthesis is a nascent technology, with great promise for capture of CO2 using sunlight. To improve low yields, it has been proposed that photosynthetic capacity can be increased by a relaxation of bottlenecks inherent to growth. The limits of carbon partitioning away from growth within the cell and the effect of partitioning on carbon fixation are not well known. Here we show that expressing genes in a pathway between carbon fixation and pyruvate increases partitioning to 2,3-butanediol (23BD) and leads to a 1.8-fold increase in total carbon yield in the cyanobacterium Synechococcus elongatus PCC 7942. Specific 2,3-butanediol production increases 2.4-fold. As partitioning increases beyond 30%, it leads to a steep decline in total carbon yield. The data suggests a local maximum for carbon partitioning from the Calvin Benson cycle that is scalable with light intensity.

  12. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  13. Homogeneous Carbon Nanotube/Carbon Composites Prepared by Catalyzed Carbonization Approach at Low Temperature

    Directory of Open Access Journals (Sweden)

    Hongjiang Li

    2011-01-01

    Full Text Available We synthesize carbon nanotube (CNT/carbon composite using catalyzed carbonization of CNT/Epoxy Resin composite at a fairly low temperature of about 400∘C. The microstructure of the composite is characterized by scanning electron microscope (SEM, transmission electron microscope (TEM, and X-ray diffraction (XRD. The results indicate that CNTs and pyrolytic carbon blend well with each other. Pyrolytic carbon mainly stays in an amorphous state, with some of it forming crystalline structures. The catalyst has the effect of eliminating the interstices in the composites. Remarkable increases in thermal and electrical conductivity are also reported.

  14. Carbon footprinting : a classroom exercise

    Energy Technology Data Exchange (ETDEWEB)

    Bryan, H.; Grimm, M. [Arizona State Univ., Tempe (United States). School of Architecture and Landscape Architecture, College of Design

    2009-07-01

    This paper reported on an ongoing initiative at Arizona State University (ASU) to reduce the carbon footprint of buildings on campus. The College of Design and the Global Institute of Sustainability created a graduate level class where students in the fields of architecture, building design, urban planning, and sustainability applied a methodology to determine and improve a building's carbon footprint. Launched in 2008, the project currently has 13 buildings and will be expanded up to 50 buildings by the end of 2009. ASU is initially committing to carbon reduction and eventual carbon neutrality. The project offers students an opportunity to view the impact of their daily behaviours in terms of energy consumption and carbon emissions. The carbon footprinting methodology was used in a classroom setting by graduate students at ASU College of Design and School of Sustainability to determine the carbon footprint of 3 campus buildings. The methodology included an energy consumption analysis of the existing building, the creation of an as-built energy model, and the study of carbon footprint improvement scenarios with the ultimate goal of achieving carbon neutrality. Each improvement scenario was analyzed to determine its effect on overall carbon footprint and annual energy consumption, including electricity and natural gas use. 6 refs., 10 tabs., 4 figs.

  15. The Toxicology of Carbon Nanotubes

    Science.gov (United States)

    Donaldson, Ken; Poland, Craig; Duffin, Rodger; Bonner, James

    2012-06-01

    1. Carbon nanotube structure, synthesis and applications C. Singh and W. Song; 2. The aerodynamic behaviour and pulmonary deposition of carbon nanotubes A. Buckley, R. Smith and R Maynard; 3. Utilising the concept of the biologically effective dose to define the particle and fibre hazards of carbon nanotubes K. Donaldson, R. Duffin, F. Murphy and C. Poland; 4. CNT, biopersistence and the fibre paradigm D. Warheit and M. DeLorme; 5. Length-dependent retention of fibres in the pleural space C. Poland, F. Murphy and K. Donaldson; 6. Experimental carcinogenicity of carbon nanotubes in the context of other fibres K. Unfried; 7. Fate and effects of carbon nanotubes following inhalation J. Ryman-Rasmussen, M. Andersen and J. Bonner; 8. Responses to pulmonary exposure to carbon nanotubes V. Castranova and R. Mercer; 9. Genotoxicity of carbon nanotubes R. Schins, C. Albrecht, K. Gerloff and D. van Berlo; 10. Carbon nanotube-cellular interactions; macrophages, epithelial and mesothelial cells V. Stone, M. Boyles, A. Kermanizadeh, J. Varet and H. Johnston; 11. Systemic health effects of carbon nanotubes following inhalation J. McDonald; 12. Dosimetry and metrology of carbon nanotubes L. Tran, L. MacCalman and R. Aitken; Index.

  16. Black carbon and organic carbon emissions from wildfires in Mexico

    OpenAIRE

    XÓCHITL CRUZ NÚÑEZ; LOURDES VILLERS RUIZ; CARLOS GAY GARCÍA

    2014-01-01

    In Mexico, approximately 7650 wildfires occur annually, affecting 263 115 hectares of land. In addition to their impact on land degradation, wildfires cause deforestation, damage to ecosystems and promote land use change; apart from being the source of emissions of toxic substances to the environment (i.e., hydrogen cya - nide, black carbon and organic carbon). Black carbon is a short-lived greenhouse pollutant that also promotes snow and ice melting and decreased rainfall; it has an estimate...

  17. Carbon isotope anomalies in carbonates of the Karelian series

    Science.gov (United States)

    Iudovich, Ia. E.; Makarikhin, V. V.; Medvedev, P. V.; Sukhanov, N. V.

    1990-07-01

    Results are presented on carbon isotope distributions in carbonates of the Karelian complex. A highly anomalous isotopic composition was found in carbonate rocks aged from 2.6 to 1.9 b.y. In the stromatolitic carbonates of the Onega water table, delta-(C-13) reaches a value of +18 percent, while the shungite layer of the Zaonega horizon is characterized by a wide dispersion (from +7.9 to -11.8 percent). These data are in good agreement with the known geochemical boundary (about 2.2 b.y. ago) in the history of the earth.

  18. Multiporous carbon allotropes transformed from symmetry-matched carbon nanotubes

    Directory of Open Access Journals (Sweden)

    Yingxiang Cai

    2016-06-01

    Full Text Available Carbon nanotubes (CNTs with homogeneous diameters have been proven to transform into new carbon allotropes under pressure but no studies on the compression of inhomogeneous CNTs have been reported. In this study, we propose to build new carbon allotropes from the bottom-up by applying pressure on symmetry-matched inhomogeneous CNTs. We find that the (3,0 CNT with point group C3v and the (6,0 CNT with point group C6v form an all sp3 hybridized hexagonal 3060-Carbon crystal, but the (4,0 CNT with point group D4h and the (8,0 CNT with point group D8h polymerize into a sp2+sp3 hybridized tetragonal 4080-Carbon structure. Their thermodynamic, mechanical and dynamic stabilities show that they are potential carbon allotropes to be experimentally synthesized. The multiporous structures, excellently mechanical properties and special electronic structures (semiconductive 3060-Carbon and semimetallic 4080-Carbon imply their many potential applications, such as gases purification, hydrogen storage and lightweight semiconductor devices. In addition, we simulate their feature XRD patterns which are helpful for identifying the two carbon crystals in future experimental studies.

  19. Carbon Micronymphaea: Graphene on Vertically Aligned Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Jong Won Choi

    2013-01-01

    Full Text Available This paper describes the morphology of carbon nanomaterials such as carbon nanotube (CNT, graphene, and their hybrid structure under various operating conditions during a one-step synthesis via plasma-enhanced chemical vapor deposition (PECVD. We focus on the synthetic aspects of carbon hybrid material composed of heteroepitaxially grown graphene on top of a vertical array of carbon nanotubes, called carbon micronymphaea. We characterize the structural features of this unique nanocomposite by uses of electron microscopy and micro-Raman spectroscopy. We observe carbon nanofibers, poorly aligned and well-aligned vertical arrays of CNT sequentially as the growth temperature increases, while we always discover the carbon hybrids, called carbon micronymphaea, at specific cooling rate of 15°C/s, which is optimal for the carbon precipitation from the Ni nanoparticles in this study. We expect one-pot synthesized graphene-on-nanotube hybrid structure poses great potential for applications that demand ultrahigh surface-to-volume ratios with intact graphitic nature and directional electronic and thermal transports.

  20. Development of improved coating for advanced carbon-carbon components

    Science.gov (United States)

    Yamaki, Y. R.; Brown, J. J.

    1984-01-01

    Reaction sintered silicon nitride (RSSN) was studied as a substitute coating material on the carbon-carbon material (RCC) presently used as a heat shield on the space shuttle, and on advanced carbon-carbon (ACC), a later development. On RCC, RSSN showed potential in a 538 C (1000 F) screening test in which silicon carbide coated material exhibits its highest oxidation rate; RSSN afforded less protection to ACC because of a larger thermal expansion mismatch. Organosilicon densification and metallic silicon sealing methods were studied as means of further increasing the oxidation resistance of the coating, and some improvement was noted when these methods were employed.