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  1. Zinc In CCl4 Toxicity

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To investigate the protective effect of zinc in CCl4-induced hepatotoxicity. Methods Rats were treated with zinc acetate for four days. The zinc doses were 5 mg Zn/kg and 10 mg Zn/kg body weight respectively. Two groups of the zinc acetate-treated rats were later challenged with a single dose of CCl4 (1.5 mL/kg body weight). Results Compared to control animals, the plasma of rats treated with CCl4 showed hyperbilirubinaemia, hypoglycaemia, hypercreatinaemia and hypoproteinaemia. When the animals were however supplemented with zinc in form of zinc acetate before being dosed with CCl4, the 5 mg Zn/kg body weight of zinc acetate reversed the hypoproteinaemia induced by CCl4, whereas the 10mg Zn/kg body weight of zinc acetate reversed the hypoglycaemia, hyperbilimbinaemia and hypercreatinaemia induced by CCl4. Conclusion The 10mug Zn/kg body weight of zinc acetate is more consistent in protecting against CCl4 hepatotoxicity. The possible mechanisms of protection are highlighted.

  2. Adsorption of CCl4 on graphite

    Science.gov (United States)

    Stephens, Peter W.; Huth, Martin F.

    1985-08-01

    We have performed a comprehensive x-ray scattering study of CCl4 adsorbed on exfoliated graphite. We observe the following features. At low coverages, there is an incommensurate triangular monolayer solid, with a gas-liquid-solid triple point at 195 K. Below a temperature of 215 K the graphite is partially wet by only one monolayer. The monolayer solid has a maximum melting temperature of ~246 K. A two-layer solid phase, which melts at 236 K, does not have a simple triangular structure. There is a liquid prewetting film of at least ten layers thickness at 246 K, 4 K below the bulk CCl4 triple point.

  3. 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.

  4. Fucoidan partly prevents CCl4-induced liver fibrosis

    OpenAIRE

    Hayashi, Shinji; Itoh, Ayano; Isoda, Katsuhiro; Kondoh, Masuo; KAWASE, Masaya; Yagi, Kiyohito

    2008-01-01

    Fucoidan, a sulfated polysaccharide extracted from brown algae, has a wide range of biological activities, including anti-inflammatory, anti-viral, and anti-tumor activities. In the present study, we investigated the effects of fucoidan on CCl4-induced liver fibrosis. Administration of fucoidan reduced CCl4-induced acute and chronic liver failure. Hepatic fibrosis induced by CCl4 was also attenuated by injection of fucoidan. Damage to hepatocytes and activation of hepatic stellate cells are k...

  5. 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.

  6. Estrogen reduces CCL4- induced liver fibrosis in rats

    Institute of Scientific and Technical Information of China (English)

    Jun-Wang Xu; Jun Gong; Xin-Ming Chang; Jin-Yan Luo; Lei Dong; Zhi-Ming Hao; Ai Jia; Gui-Ping Xu

    2002-01-01

    AIM: Chronic liver diseases, such as fibrosis or cirrhosis,are more common in men than in women. This genderdifference may be related to the effects of sex hormones onthe liver. The aim of the present work was to investigatethe effects of estrogen on CCL4-induced fibrosis of the liverin rats.METHODS: Liver fibrosis was induced in male, female andovariectomized rats by CCL4 administration. All the groupswere treated with estradiol(1 mg/kg) twice weekly. Andtamoxifen wasgiven to male fibrosis model. At the end of 8weeks, all therats were killed to study serum indicators andthe livers.RESULTS: Estradiol treatment reduced aspartateaminotransferase(AST), alanine aminotransferase (ALT),hyaluronic acid(HA) and type IV collagen(CIV) in sera,suppressed hepatic collagen content, decreased the areas ofhepatic stellate cells (HSC) positive for α-smooth muscle actin(α-SMA), and lowered the synthesis of hepatic type I collagensignificantly in both sexes and ovariectomy fibrotic rats inducedby CCL4 administration. Whereas, tamoxifen had the oppositeeffect. The fibrotic response of the female liver to CCL4treatment was significantly weaker than that of male liver.CONCLUSION: Estradiol reduces CCL4-induced hepaticfibrosis in rats. The antifibrogenic role of estrogen in theliver may be one reason for the sex associated differencesin the progression from hepatic fibrosis to cirrhosis.

  7. Dynamic Heterogeneity In The Monoclinic Phase Of CCl$_4$

    CERN Document Server

    Caballero, Nirvana B; Carignano, Marcelo; Serra, Pablo

    2016-01-01

    Carbon tetrachloride (CCl$_4$) is one of the simplest compounds having a translationally stable monoclinic phase while exhibiting a rich rotational dynamics below 226 K. Recent nuclear quadrupolar resonance (NQR) experiments revealed that the dynamics of CCl$_4$ is similar to that of the other members of the isostructural series CBr$_{n}$Cl$_{4-n}$, suggesting that the universal relaxation features of canonical glasses such as $\\alpha$- and $\\beta$-relaxation are also present in non-glass formers. Using molecular dynamics (MD) simulations we studied the rotational dynamics in the monoclinic phase of CCl$_4$. The molecules undergo $C3$ type jump-like rotations around each one of the four C-Cl bonds. The rotational dynamics is very well described with a master equation using as the only input the rotational rates measured from the simulated trajectories. It is found that the heterogeneous dynamics emerges from faster and slower modes associated with different rotational axes, which have fixed orientations relat...

  8. Effect of schisandrin B and sesamin mixture on CCl(4)-induced hepatic oxidative stress in rats.

    Science.gov (United States)

    Chang, Chia-Yu; Chen, Ya-Ling; Yang, Suh-Ching; Huang, Guan-Cheng; Tsi, Daniel; Huang, Chi-Chang; Chen, Jiun-Rong; Li, Joe-Sharg

    2009-02-01

    To study the effects of schisandrin B and sesamin mixture on carbon tetrachloride (CCl(4))-induced hepatic oxidative stress in male Sprague-Dawley rats. The rats were randomly assigned to five groups: control group (olive oil injection), CCl(4) group (CCl(4) injection), silymarin group (CCl(4) injection combined with supplementation of silymarin, 7.5 mg/kg/day), low dose group (CCl(4) injection combined with supplementation of schisandrin B and sesamin mixture at a low dose, 43 mg/kg/day) and high dose group (CCl(4) injection combined with the supplementation of schisandrin B and sesamin mixture at a high dose, 215 mg/kg/day). The hepatic superoxide dismutase and glutathione peroxidase activities of rats in the low dose and high dose groups were increased significantly compared with those in the CCl(4) group. The hepatic reduced glutathione concentration in the silymarin, low dose and high dose groups were increased significantly (48%, 45% and 53%, respectively) when compared with those of the CCl(4) group. In addition, the concentration of glutathione in the erythrocytes of the low dose group was significantly higher than the CCl(4) group by 25%. These results suggest that the schisandrin B-sesamin mixture exerted a hepatoprotective effect by improving the antioxidative capacity in rats under CCl(4)-induced hepatic oxidative stress.

  9. Decomposition of CCl4 and CHCl3 on gliding arc plasma

    Institute of Scientific and Technical Information of China (English)

    Antonius Indarto; CHOI Jae-wook; LEE Hwaung; SONG Hyung-keun

    2006-01-01

    Decomposition of chlorinated hydrocarbons, CCl4 and CHCl3, in gliding plasma was examined. The effects of initial concentrations, total gas flow rates, and power consumption have been investigated. The conversion result was relatively high. It reached 80% for CCl4 and 97% for CHCl3. Using atmospheric air as the carrier gas, the plasma reaction occurred at exothermic reaction and the main products were CO2, CO, and Cl2. Transformation into CCl4 was also detected for CHCl3 decomposition reaction.The conversion of CCl4 and CHCl3 were increased with the increasing applied frequency and decreasing total gas flow rate.

  10. Lygodium flexuosum extract down regulates the expression of proinflammatory cytokines in CCl4 -induced hepatotoxicity

    Institute of Scientific and Technical Information of China (English)

    Pallara Janardhanan Wills; Velikkakathu Vasumathi Asha

    2012-01-01

    Objective:To examine the downregulation of proinflammatory cytokines in a time dependant manner on carbon tetrachloride induced toxicity in experimental animals.Methods:CCl4(150 μL/100 g) was dissolved in corn oil(1:1 v/v%) and administered orally.GroupI was treated as normal control and received corn oil on8th day.GroupII was toxic control and was given a single dose ofCCl4 on8th days.GroupIII wastreated withLygodium flexuosum(L. flexuosum)n-hexane extract(200 mg/kg) for8 days and on8th day a single dose ofCCl4 was received.GroupIV(negative control) receivedL. flexuosumn-hexane extract(200 mg/kg) alone for8 days.Results:Treatment withn-hexane extract prior to the administration ofCCl4 significantly prevented an increase in serumAST,ALT,LDH activity and lipid peroxidation and prevented the depletion of glutathione (GSH).Rats treated withL. flexuosum had reduced mRNA levels ofTGF-β1,TNF-α andIL-1βgenes in liver ofCCl4 intoxicated rats when compared toCCl4 control as evidenced byRT-PCR. Conclusions:The data suggest that L. flexuosum, a widely available fern, significantly reduces CCl4 induced acute hepatotoxicity by down-regulating the expression of pro-inflammatory cytokines in rats.

  11. 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.

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

    OpenAIRE

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

    2012-01-01

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

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

    Science.gov (United States)

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

    2012-07-01

    This study was performed to examine the hepatoprotective effect of isorhamnetin-3-O-galactoside, a flavonoid glycoside isolated from Artemisia capillaris Thunberg (Compositae), against carbon tetrachloride (CCl4)-induced hepatic injury. Mice were treated intraperitoneally with vehicle or isorhamnetin-3-O-galactoside (50, 100, and 200 mg/kg) 30 min before and 2 h after CCl4 (20 μl/kg) injection. Serum aminotransferase activities and hepatic level of malondialdehyde were significantly higher after CCl4 treatment, and these increases were attenuated by isorhamnetin-3-O-galactoside. CCl4 markedly increased serum tumor necrosis factor-α level, which was reduced by isorhamnetin-3-O-galactoside. The levels of inducible nitric oxide synthase (iNOS), cyclooxygenase- 2 (COX-2), and heme oxygenase-1 (HO-1) protein and their mRNA expression levels were significantly increased after CCl4 injection. The levels of HO-1 protein and mRNA expression levels were augmented by isorhamnetin-3-O-galactoside, while isorhamnetin- 3-O-galactoside attenuated the increases in iNOS and COX-2 protein and mRNA expression levels. CCl4 increased the level of phosphorylated c-Jun N-terminal kinase, extracellular signal-regulated kinase and p38, and isorhamnetin-3-O-galactoside reduced these increases. The nuclear translocation of nuclear factor kappa B (NF-κB), activating protein-1, and nuclear factor erythroid 2-related factor 2 (Nrf2) were signifi cantly increased after CCl4 administration. Isorhamnetin-3-O-galactoside attenuated the increases of NF-κB and c-Jun nuclear translocation, while it augmented the nuclear level of Nrf2. These results suggest that isorhamnetin-3-O-galactoside ameliorates CCl4-induced hepatic damage by enhancing the anti-oxidative defense system and reducing the inflammatory signaling pathways.

  14. Vibrational spectroscopy of SnBr4 and CCl4 using Lie algebraic approach

    Indian Academy of Sciences (India)

    Joydeep Choudhury; Srinivasa Rao Karmuri; Nirmal Kumar Sarkar; Ramendu Bhattacharjee

    2008-09-01

    The stretching and bending vibrational energies of SnBr4 and CCl4 are calculated in the one-dimensional framework. The dynamical symmetry group of tetrahedral molecule was taken into consideration to construct the model Hamiltonian in this frame-work. Casimir and Majorana invariant operators were also determined accordingly. Using the model Hamiltonian so constructed, we reported the vibrational energy levels of SnBr4 and CCl4 molecules accurately.

  15. Face-Centred-Cubic Artificial Opal Embedded with CdS Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    徐岭; 李明海; 张宇; 马懿; 徐骏; 黄信凡; 陈坤基

    2002-01-01

    Highly monodispersed colloidal silica spheres in sub-micrometre size with distribution standard deviation less than 5% were synthesized by a chemical method. Using the self-crystallization of the silica spheres, we successfully obtained the three-dimensional close-packed face-centred-cubic silica matrices and artificial opals. Then,a colloidal photonic crystal embedded with CdS quantum dots (QDs) was also chemically prepared by using artificial opals as a template. A reflection spectra study reveals that both artificial opals with and without CdS QDs possess (111) directional photonic bandgap features.

  16. Experimental study on CCl4/CH)4/O2/N2 oxidation

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Oxidation within the system CCl4/CH4/O2/N2 is studied at atmospheric pressure in a tubular flow reactor to investigate the influence of reaction temperature and chlorine content on chlorinated waste combustion and find incineration process optimization methods for pollution control.The reaction temperature varies from 700℃ to 1000℃ and the CCl4/CH4(or Cl/H) mole ratio of the inlet mixture varies from 0.21 to 0.84.Products profiles are measured with FT-IR.It is shown that at the same initial CCl4 concentration and reaction temperature adding CH4 favors CCl4 destruction and CO2 formation.But the destruction and removal efficiency(DRE) of CH4 decreases with lower Cl/H and higher concentrations of toxic products of incomplete combustion such as COCl2 and CH3Cl are formed at the same time.The chlorine in the system favors CH4 decomposition,but it also inhibits further oxidation of CO.Higher temperature assists in both CCl4 destruction and CH4 conversion,and the concentration of toxic combustion intermediates is reduced.Increasing the temperature is the most effective way to enhance CCl4 oxidation.The CO2 concentration increases with temperature.A CO concentration peak is observed around 800℃:with a certain Cl/H,the CO concentration first increases with temperature and then declines.The effect of increasing CH4 concentration on CCl4 destruction becomes mild above 900℃.Rather,it enhances the interaction between chlorine and carbonaceous radicals,which leads to higher concentration of toxic products.

  17. STRATIGRAPHIC CONTROL ON CCL4 AND CHCL3 CONCENTRATIONS IN THE 200 WEST AREA, HANFORD SITE

    Energy Technology Data Exchange (ETDEWEB)

    Winsor, K.; Last, G.V.

    2008-01-01

    An extensive subsurface contaminant plume of carbon tetrachloride (CCl4) is the focus of a remedial effort in the 200 West Area of the U.S. Department of Energy’s Hanford Site in eastern Washington. Remediation requires a high-resolution understanding of the region’s spatially variable lithofacies and of the effect these lithofacies have on CCl4 migration through the unconfi ned aquifer. To increase the level of detail of our current understanding, a transect was chosen along the primary groundwater fl ow path in the most heavily contaminated area. Borehole logs of wells along this 3.7 km-long transect were standardized and used to create a cross section displaying the depth and continuity of lithofacies. Natural and spectral gamma geophysical logs were examined to pinpoint the depths of geologic units. Depth discrete concentrations of CCl4 and its reductive dechlorination product, chloroform (CHCl3), were overlain on this cross section. Comparison of stratigraphy to contaminant levels shows that peaks in CCl4 concentration occur in thin, fine-grained layers and that other fine-grained layers frequently form lower boundaries to regions of high concentration. Peaks in CCl4 concentrations are frequently located at different depths from those of CHCl3, suggesting that these concentrations are affected by dechlorination of CCl4. Transformation of CCl4 to CHCl3 appears to be more prevalent within reduced, iron-containing sediments. The infl uence of thin, fine-grained layers within the larger aquifer unit indicates that characterization of contamination in this locality should consider subsurface geology with at least as much resolution as provided in this study.

  18. Effect of Platelet-Rich Plasma on CCl4-Induced Chronic Liver Injury in Male Rats

    Directory of Open Access Journals (Sweden)

    Zahra Hesami

    2014-01-01

    Full Text Available Platelet-rich plasma (PRP has been of great concern to the scientists and doctors who are involved in wound healing and regenerative medicine which focuses on repairing and replacing damaged cells and tissues. Growth factors of platelet-rich plasma are cost-effective, available, and is more stable than recombinant human growth factors. Given these valuable properties, we decided to assess the effect of PRP on CCl4-induced hepatotoxicity on rats. The rats received CCl4 (1 mL/kg, i.p. 1 : 1 in olive oil twice per week for 8 weeks. Five weeks after CCl4 injection, the rats also received PRP (0.5 mL/kg, s.c. two days a week for three weeks. Twenty-four hours after last CCl4 injection, the animals bled and their livers dissected for biochemical and histopathological studies. Blood analysis was performed to evaluate enzyme activity. The results showed that PRP itself was not toxic for liver and could protect the liver from CCl4-induced histological damages and attenuated oxidative stress by increase in glutathione content and decrease in lipid peroxidative marker of liver tissue. The results of the present study lend support to our beliefs in hepatoprotective effects of PRP.

  19. Protective effects of L-carnosine on CCl4 -induced hepatic injury in rats.

    Science.gov (United States)

    Alsheblak, Mehyar Mohammad; Elsherbiny, Nehal M; El-Karef, Amro; El-Shishtawy, Mamdouh M

    2016-03-01

    The present study was undertaken to investigate the possible protective effect of L-carnosine (CAR), an endogenous dipeptide of alanine and histidine, on carbon tetrachloride (CCl4)-induced hepatic injury. Liver injury was induced in male Sprague-Dawley rats by intraperitoneal (i.p.) injections of CCl4, twice weekly for six weeks. CAR was administered to rats daily, at dose of 250 mg/kg, i.p. At the end of six weeks, blood and liver tissue specimens were collected. Results show that CAR treatment attenuated the hepatic morphological changes, necroinflammation and fibrosis induced by CCl4, as indicated by hepatic histopathology scoring. In addition, CAR treatment significantly reduced the CCl4-induced elevation of liver-injury parameters in serum. CAR treatment also combatted oxidative stress; possibly by restoring hepatic nuclear factor erythroid 2-related factor 2 (Nrf-2) levels. Moreover, CAR treatment prevented the activation of hepatic stellate cells (HSCs), as indicated by reduced α-smooth muscle actin (α-SMA) expression in the liver, and decreased hepatic inflammation as demonstrated by a reduction in hepatic tumor necrosis factor-α (TNF-α) and restoration of interleukin-10 (IL-10) levels. In conclusion, CCl4-induced hepatic injury was alleviated by CAR treatment. The results suggest that these beneficial, protective effects are due, at least in part, to its anti-oxidant, anti-inflammatory and anti-fibrotic activities.

  20. Herbal Supplement Ameliorates Cardiac Hypertrophy in Rats with CCl4-Induced Liver Cirrhosis

    Directory of Open Access Journals (Sweden)

    Ping-Chun Li

    2012-01-01

    Full Text Available We used the carbon tetrachloride (CCl4 induced liver cirrhosis model to test the molecular mechanism of action involved in cirrhosis-associated cardiac hypertrophy and the effectiveness of Ocimum gratissimum extract (OGE and silymarin against cardiac hypertrophy. We treated male wistar rats with CCl4 and either OGE (0.02 g/kg B.W. or 0.04 g/kg B.W. or silymarin (0.2 g/kg B.W.. Cardiac eccentric hypertrophy was induced by CCl4 along with cirrhosis and increased expression of cardiac hypertrophy related genes NFAT, TAGA4, and NBP, and the interleukin-6 (IL-6 signaling pathway related genes MEK5, ERK5, JAK, and STAT3. OGE or silymarin co-treatment attenuated CCl4-induced cardiac abnormalities, and lowered expression of genes which were elevated by this hepatotoxin. Our results suggest that the IL-6 signaling pathway may be related to CCl4-induced cardiac hypertrophy. OGE and silymarin were able to lower liver fibrosis, which reduces the chance of cardiac hypertrophy perhaps by lowering the expressions of IL-6 signaling pathway related genes. We conclude that treatment of cirrhosis using herbal supplements is a viable option for protecting cardiac tissues against cirrhosis-related cardiac hypertrophy.

  1. Oxidative stress modulation by Rosmarinus officinalis in CCl4-induced liver cirrhosis.

    Science.gov (United States)

    Gutiérrez, Rosalinda; Alvarado, José L; Presno, Manuel; Pérez-Veyna, Oscar; Serrano, Carmen J; Yahuaca, Patricia

    2010-04-01

    Rosmarinus officinalis (Lamiaceae) possesses antioxidant activity and hepatoprotective effects, and so may provide a possible therapeutic alternative for chronic liver disease. The effect produced by a methanolic extract of Rosmarinus officinalis on CCl(4)-induced liver cirrhosis in rats was investigated using both prevention and reversion models. Over the course of the development of cirrhosis, the increased enzymatic activities of gamma-glutamyl transpeptidase and alanine aminotransferase, and the rise in bilirubin levels caused by CCl(4) administration, were prevented by Rosmarinus officinalis co-administration. When the cirrhosis by oxidative stress was evaluated as an increase on liver lipoperoxidation, total lipid peroxides, nitric oxide in serum, and loss of erythrocyte plasma membrane stability, R. officinalis was shown to prevent such alterations. On cirrhotic animals treated with CCl(4), histological studies showed massive necrosis, periportal inflammation and fibrosis which were modified by R. officinalis. These benefits on experimental cirrhosis suggest a potential therapeutic use for R. officinalis as an alternative for liver cirrhosis.

  2. PROTECTIVE EFFECT OF Solanum Pubescens LINN ON CCL4 INDUCED HEPATOTOXICITY IN ALBINO RATS

    Directory of Open Access Journals (Sweden)

    M.Pushpalatha

    2012-01-01

    Full Text Available Ethanol extract of Solanum pubescens Linn was evaluated for hepato protective and antioxidant activities in rats. The plant extract (500mg/kg/day showed a remarkable hepatoprotective and antioxidant activity against Carbon tetrachloride (CCl4-induced hepatotoxicity as judged from the serum marker enzymes and antioxidant levels in liver tissues. CCl4 induced a significant rise in aspartate amino transferase (AST, alanine amino transferase (ALT, alkaline phosphatase (ALP, total bilirubin, LPO with a reduction of total protein, superoxide dismutase (SOD, catalase, and reduced glutathione (GSH. Treatment of rats with plant extract (500 mg/kg significantly (P<0.01 altered serum marker enzymes and antioxidant levels to near normal against CCl4 - treated rats. The activity of the extract at dose of 500 mg/kg was comparable to the standard drug, Silymarin (50 mg/kg, p.o.. Histopathological examination of the liver tissues supported the hepatoprotective activity of plant.

  3. Effects of platelet-rich plasma on liver regeneration in CCl4-induced hepatotoxicity model.

    Science.gov (United States)

    Mafi, Afsaneh; Dehghani, Farzaneh; Moghadam, Abbas; Noorafshan, Ali; Vojdani, Zahra; Talaei-Khozani, Tahereh

    2016-12-01

    Numerous bioactive growth factors and cytokines in platelet-rich plasma (PRP) have recently made it an attractive biomaterial for therapeutic purposes. These growth factors have the potential to regenerate the injured tissues. The aim of this study was to investigate the therapeutic effects of PRP in hepatotoxic animal model. Hepatotoxicity was induced in rats by oral administration of 4 mL/kg/week of CCl4 diluted 1:1 in corn oil for 10 weeks. To confirm the hepatotoxicity, 24 h after the last CCl4 administration, blood samples were collected via cardiac puncture to assess the serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, albumin, total protein, and total bilirubin. Twenty-four hours after blood collection, the experimental animals received a single injection of PRP (1 mL) via the anterior mesenteric vein. One week later, all biochemical tests were performed again, and the rats were scarified and their livers were removed, prepared histologically, and stained. The stereological analyses were performed to evaluate the effects of PRP on histopathological features of CCl4-treated livers. The results were compared statistically with the corresponding control and CCl4+normal saline (NS)-treated animals. A significant decrease in the number and volume of hepatocytes (p = 0.01), and also a reduction in the volume of sinusoids (p = 0.001) and connective tissue (p = 0.04), were observed in the PRP-treated animals compared with the CCl4+NS-treated ones. Our findings demonstrated that application of PRP had beneficial effects on CCl4-induced fibrosis; however, it had detrimental effects on the total number of hepatocytes and the volume of hepatocytes and sinusoidal spaces.

  4. Isoflavones-Enriched Soy Protein Prevents CCL4-Induced Hepatotoxicity in Rats

    OpenAIRE

    Sarhan, Nesma A. Z.; Ezzeldein S. El-Denshary; Hassan, Nabila S.; Abu-Salem, Ferial M.; Abdel-Wahhab, Mosaad A.

    2012-01-01

    The burden of liver disease in Egypt is exceptionally high due to the highest prevalence of hepatitis C virus (HCV) resulting in rising rates of hepatocellular carcinoma (HCC). The aim of the current study was to determine the isoflavones in soy and to evaluate the protective role of soy against CCl4-induced liver damage in rats. Four experimental groups were treated for 8 weeks and included the control group, soy-supplemented diet (20% w/w) group, the group treated orally with CCl4 (100 mg/k...

  5. Antioxidant and protective effect of inulin and catechin grafted inulin against CCl4-induced liver injury.

    Science.gov (United States)

    Liu, Jun; Lu, Jian-feng; Wen, Xiao-yuan; Kan, Juan; Jin, Chang-hai

    2015-01-01

    In this study, the antioxidant activity and hepatoprotective effect of inulin and catechin grafted inulin (catechin-g-inulin) against carbon tetrachloride (CCl4)-induced acute liver injury were investigated. Results showed that both inulin and catechin-g-inulin had moderate scavenging activity on superoxide radical, hydroxyl radical and H2O2, as well as lipid peroxidation inhibition effect. The antioxidant activity decreased in the order of Vc > catechin >catechin-g-inulin > inulin. Administration of inulin and catechin-g-inulin could significantly reduce the elevated levels of serum aspartate transaminase, alanine transaminase and alkaline phosphatase as compared to CCl4 treatment group. Moreover, inulin and catechin-g-inulin significantly increased the levels of hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione and total antioxidant capacity, whereas markedly decreased the malondialdehyde level when compared with CCl4 treatment group. Notably, catechin-g-inulin showed higher hepatoprotective effect than inulin. In addition, the hepatoprotective effect of catechin-g-inulin was comparable to positive standard of silymarin. Our results suggested that catechin-g-inulin had potent antioxidant activity and potential protective effect against CCl4-induced acute liver injury.

  6. Hepatoprotection with a chloroform extract of Launaea procumbens against CCl4-induced injuries in rats

    Directory of Open Access Journals (Sweden)

    Khan Rahmat A

    2012-08-01

    Full Text Available Abstract Background Launaea procumbens (Asteraceae is used as a folk medicine to treat hepatic disorders in Pakistan. The effect of a chloroform extract of Launaea procumbens (LPCE was evaluated against carbon-tetrachloride (CCl4-induced liver damage in rats. Methods To evaluate the hepatoprotective effects of LPCE, 36 male Sprague–Dawley rats were equally divided into six groups. Animals of group 1 (control had free access to food and water. Group II received 3 ml/kg of CCl4 (30% in olive oil v/v via the intraperitoneal route twice a week for 4 weeks. Group III received 1 ml of silymarin via gavage (100 mg/kg b.w. after 48 h of CCl4 treatment whereas groups IV and V were given 1 ml of LPCE (100 and 200 mg/kg b.w., respectively after 48 h of CCl4 treatment. Group VI received 1 ml of LPCE (200 mg/kg b.w. twice a week for 4 weeks. The activities of the antioxidant enzymes catalase, peroxidase (POD, superoxide dismutase (SOD, glutathione peroxidase (GSH-Px, glutathione S-transferase (GST, glutathione reductase (GSR, glutathione (GSH and lipid peroxidation (thiobarbituric acid reactive substances (TBARS were measured in liver homogenates. DNA damage, argyrophilic nucleolar organizer regions (AgNORs counts and histopathology were studied in liver samples. Serum was analyzed for various biochemical parameters. Phytochemical composition in LPCE was determined through high-performance liquid chromatography (HPLC. Results LPCE inhibited lipid peroxidation, and reduced the activities of aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase in serum induced by CCl4. GSH contents were increased as were the activities of antioxidant enzymes (catalase, SOD, GST, GSR, GSH-Px when altered due to CCl4 hepatotoxicity. Similarly, absolute liver weight, relative liver weight and the number of hepatic lesions were reduced with co-administration of LPCE. Phyochemical analyses of LPCE indicated that it contained catechin

  7. Ferroelectric phase transition in hydrogen-bonded 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4

    CERN Document Server

    Czapla, Z; Waskowska, A

    2003-01-01

    A new crystal of 2-aminopyridine phosphate (NC sub 4 H sub 4 NH sub 2)centre dot H sub 3 PO sub 4 has been grown and its x-ray structure and physical properties were studied. At room temperature the crystals are monoclinic, space group C2/c. The flat 2-aminopyridine cations are hydrogen bonded to the anionic [PO sub 4 ] groups. The interesting feature of the crystal structure is the three-dimensional network of hydrogen bonds including, among others, two strong, symmetrical O centre dot centre dot centre dot H, H centre dot centre dot centre dot O interactions with disordered proton locations. Symmetrically related PO sub 4 anions linked through these protons form infinite (PO sub 4) subinfinity chains along the crystal a-axis. The anomalies in the temperature dependence of the electric permittivity showed that the crystal undergoes ferroelectric phase transition at T sub c = 103.5 K. The spontaneous polarization takes place along the crystal a-axis, being parallel to the chains of the hydrogen-bonded PO sub ...

  8. Decorin prevents the development of CCl4-induced liver fibrosis in mice

    Institute of Scientific and Technical Information of China (English)

    Ma Rui; He Shilin; Liang Xiao; Yu Hong; Liang Yuelong; Cai Xiujun

    2014-01-01

    Background Liver fibrosis normally progresses to cirrhosis and destroys the normal architecture of the liver,resulting in liver dysfunction and irreversible cirrhosis.The aim of this study was to investigate the anti-fibrosis effect and the possible underlying mechanisms of decorin.Methods The mice model of liver fibrosis was induced by intraperitoneal injection of 50% (v/v) of carbon tetrachloride (CCl4) diluted in olive oil (1 ml/kg body weight) once every 2 days for 5 weeks.Three weeks after injecting CCl4 intraperitoneally,mice were randomly divided into normal control with vehicles only (olive oil),mouse model given CCl4 only,and CCl4 plus decorin (DCN,250 μg/kg).Two weeks later,all the mice were sacrificed and their liver tissues were analyzed for the expressions of genes related to liver fibrosis and under hematoxylin-eosin staining,Masson staining,and immunohistochemical staining of all groups.Aspartate transaminase,alanine transaminase,and total bilirubin of the serum were determined for evaluation of the liver function.Results Exogenous protein decorin could reduce liver fibrosis induced by CCl4 in mice.The degree of fibrosis in the experimental group was alleviated,and the contents of collagen fibers were lower in the experimental group than those of the control group.In addition,expressions of transforming growth factor β1 and α-smooth muscle actin decreased in the experimental group.Conclusions Taking liver fibrosis model of mouse as the experimental target and by injecting exogenous protein decorin into the model,we confirmed that decorin could inhibit the expression of proteins related to fibrosis and reduce the formation of liver fibrosis in mice.

  9. Protective role of Juniperus phoenicea and Cupressus sempervirens against CCl4

    Institute of Scientific and Technical Information of China (English)

    Sanaa; Ahmed; Ali; Maha; Zaki; Rizk; Nabawia; Ali; Ibrahim; Mohga; Shafik; Abdallah; Hayat; Mohamed; Sharara; Magda; Mohamed; Moustafa

    2010-01-01

    AIM: To investigate the role of Cupressus sempervirens (C. sempervirens) and Juniperus phoenicea (J. phoe-nicea) extracts as therapeutic effect against CCl4 with biochemical, histopathological evaluations. METHODS: A single intraperitoneal dose of 10% CCl4 in olive oil (1 mL/kg body weight) was administered to a group of female Wister rats, sacrificed after 24 h (as the injury group). The other groups were given CCl4 as de-scribed above and divided as follows: two groups of ten rats each were orally administered either J. phoenicea extract or C. sempervirens extract three times per week for six weeks and a further group administered CCl4 was left for six weeks to allow self-recovery. At the end of experiment, the rats from all groups were sacrificed for sampling and for biochemical and histological analysis. RESULTS: Remarkable disturbances were observed in the levels of all tested parameters. On the other hand,rats injected with the toxic agent and left for one and a half month to self recover showed moderate improve-ments in the studied parameters while, treatment with both medicinal herbal extracts ameliorated the levels of the disturbed biochemical parameters. The group treated with J. phoenicea extract showed a remarkable improvement in comparison to the CCl4 treated group. The C. sempervirens group revealing an even more re-markable effect showing histopathological liver& kidney profiles close to those of the control group.CONCLUSION: C. sempervirens and J. phoenicea leaf extracts show a remarkable effect in enhancing liver and kidney functions and may thus be of therapeutic potential in treatment hepatotoxicity and nephrotoxicity.

  10. AN INTERMOLECULAR 13C{1H} NUCLEAR OVERHAUSER EFFECT FOR THE CARBON OF CCl4 IN POLYMER SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    YAN Xin; WANG Dehua; QIAN Baogong

    1991-01-01

    An intermolecular 13C{1H} NOE of CCl4 in the solutions of polystyrene and polybutadiene and their copolymers was observed. The results show that the defined polymer-CCl4 interaction variable has a linear relation with the polymer composition and the difference of solubility parameters and exponentially depends on the reciprocal of temperature.

  11. The biofunction of orange-spotted grouper (Epinephelus coioides) CC chemokine ligand 4 (CCL4) in innate and adaptive immunity.

    Science.gov (United States)

    Hsu, Yi-Jiou; Hou, Chia-Yi; Lin, Shih-Jie; Kuo, Wan-Ching; Lin, Han-Tso; Lin, John Han-You

    2013-12-01

    CC chemokine (motif) ligand 4 (CCL4) is indispensable to the chemoattraction of macrophages, natural killer cells, and lymphocytes in mammals; however, it has only been cloned in a limited number of fish species and information related to its biofunction remains ambiguous with regard to teleosts. To explore the role of teleost CCL4, we first evaluated the mRNA expression of the Epinephelus coioides CCL4 (gCCL4) gene in various organs under LPS and poly (I:C) stimulated; secondary, we evaluated the immune-related genes expression of fish under the recombinant gCCL4 protein stimulated. Our results revealed an increase in the mRNA of gCCL4 in immune organs immediately following stimulation by poly (I:C); however, in LPS stimulated fish, the expression did not increase until nearly 24 h after induction. In biofunction assays, recombinant gCCL4 was found to induce chemotactic activity in the peripheral blood leukocytes of groupers and up-regulate the gene expressions of grouper TNFA1 (TNF-α1), TNFA2 (TNF-α2), IFNG (IFN-γ), MX, TBX21 (T-bet), CD8 (α and β chain). These findings indicate that grouper CCL4 attracts leukocytes, induces an inflammatory response, and drives lymphocyte differentiation into the Th1 pathway.

  12. Deuteron and triton production in Pb+Pb collisions at 158 A centre dot GeV.

    CERN Document Server

    Hansen, A G; Bøggild, H; Boissevain, J G; Conin, L; Christiansen, P; Dodd, J; Erazmus, B; Esumi, S; Fabjan, Christian Wolfgang; Ferenc, D; Fields, D E; Franz, A; Gaardhøje, J J; Hansen, A G; Hansen, O; Hardtke, D; Hecke, H V; Holzer, E B; Humanic, T J; Hummel, P; Jacak, B V; Jayanti, R; Kaimi, K; Kaneta, M; Kohama, T; Kopytine, M; Leltchouk, M; Ljubicic, A; Lörstad, B; Martin, L; Maeda, N; Malina, R; Medvedev, A; Murray, M; Ohnishi, H; Paic, G; Pandey, S U; Piuz, François; Pluta, J; Polychronakos, V; Potekhin, M V; Poulard, G; Reichhold, D M; Sakaguchi, A; Simon-Gillo, J; Schmidt-Sørensen, J; Sondheim, W E; Sugitate, T; Sullivan, J P; Sumi, Y; Willis, W J; Wolf, K L; Xu, N; Zachary, D S

    1999-01-01

    NA44 has measured the invariant cross section of deuterons and tritons at non zero p sub t in 158 A centre dot GeV lead on lead collisions at CERN SPS. Normalized transverse mass spectra and coalescence parameters versus p sub t have been calculated showing a significant transverse flow. Radius parameters have been extracted using a simple thermal coalescence model. Results from RQMD+coalescence calculations are compared to the data.

  13. Protective effect of alcoholic extract of Entada pursaetha DC. against CCl4-induced hepatotoxicity in rats.

    Science.gov (United States)

    Gupta, Gaurav; More, Amar Sunil; Kumari, Rashmi Rekha; Lingaraju, Madhu Cholenahalli; Kumar, Dhirendra; Kumar, Dinesh; Mishra, Santosh Kumar; Tandan, Surender Kumar

    2014-03-01

    The alcoholic extract of stem of E. pursaetha (PSE, 30, 100, 300 mg/kg body weight, po for 7 days) showed hepatoprotective activity against CCl4 (2 mL/kg body weight, ip)-induced hepatotoxicity. The extract exhibited a significant dose-dependent hepatoprotective effect comparable to standard drug silymarin, by preventing increase in serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total protein, and total bilirubin, lactate dehydrogenase; by lowering hepatic levels of malonaldehyde, nitrate-nitrite, myeloperoxidase activity; enhancing activities of antioxidant enzymes, superoxide dismutase, catalase and increasing reduced glutathione levels in liver, which suggests the antioxidant property of PSE. Histopathological studies also supported the above biochemical parameters. The results suggested that alcoholic extract of E. pursaetha possesses significant hepatoprotective activity in CCl4-induced acute hepatotoxicity in rats and this is likely to be mediated through its antioxidant activities.

  14. 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.

  15. Volumetric Properties of the Mixture Tetrachloromethane CCl4 + CHCl3 Trichloromethane (VMSD1212, LB4576_V)

    Science.gov (United States)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Tetrachloromethane CCl4 + CHCl3 Trichloromethane (VMSD1212, LB4576_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

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

    Directory of Open Access Journals (Sweden)

    Hardik Soni

    2014-09-01

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

  17. Hepatoprotective effects of baicalein against CCl4-induced acute liver injury in mice

    Institute of Scientific and Technical Information of China (English)

    Hai-Li Huang; Ya-Jing Wang; Qing-Yu Zhang; Bin Liu; Fang-Yuan Wang; Jing-Jing Li; Run-Zhi Zhu

    2012-01-01

    AIM:To investigate the hepatoprotective effect of baicalein against carbon tetrachloride (CCl4)-induced liver damage in mice.METHODS:Mice were orally administered with baicalein after CCl4 injection,and therapeutic baicalein was given twice a day for 4 d.The anti-inflammation effects of baicalein were assessed directly by hepatic histology and serum alanine aminotranferease and aspartate aminotransferase measurement.Proliferating cell nuclear antigen was used to evaluate the effect of baicalein in promoting hepatocyte proliferation.Serum interleukin (IL)-6,IL-1β and tumor necrosis factor-α (TNF-α) levels were measured by enzyme-linked immunosorbent assay and liverIL-6,TNF-α,transforming growth factor-α (TGF-α),hepatocyte growth factor (HGF) and epidermal growth factor (EGF) genes expression were determined by quantitative real-time polymerase chain reaction.RESULTS:CCl4-induced acute liver failure model offers a survival benefit in baicalein-treated mice.The data indicated that the mRNA levels of IL-6 and TNF-α significantly increased within 12 h after CCl4 treatment in baicalein administration groups,but at 24,48 and 72h,the expression of IL-6 and TNF-α was kept at lower levels compared with the control.The expression of TGF-α,HGF and EGF was enhanced dramatically in baicalein administration group at 12,24,48 and 72 h.Furthermore,we found that baicalein significantly elevated the serum level of TNF-α and IL-6 at the early phase,which indicated that baicalein could facilitate the initiating events in liver regeneration.CONCLUSION:Baicalein may be a therapeutic candidate for acute liver injury.Baicalein accelerates liver regeneration by regulating TNF-α and IL-6 mediated pathways.

  18. MicroRNA Expression Profiling in CCl4-Induced Liver Fibrosis of Mus musculus

    Directory of Open Access Journals (Sweden)

    Jeongeun Hyun

    2016-06-01

    Full Text Available Liver fibrosis is a major pathological feature of chronic liver diseases, including liver cancer. MicroRNAs (miRNAs, small noncoding RNAs, regulate gene expression posttranscriptionally and play important roles in various kinds of diseases; however, miRNA-associated hepatic fibrogenesis and its acting mechanisms are poorly investigated. Therefore, we performed an miRNA microarray in the fibrotic livers of Mus musculus treated with carbon-tetrachloride (CCl4 and analyzed the biological functions engaged by the target genes of differentially-expressed miRNAs through gene ontology (GO and in-depth pathway enrichment analysis. Herein, we found that four miRNAs were upregulated and four miRNAs were downregulated more than two-fold in CCl4-treated livers compared to a control liver. Eight miRNAs were predicted to target a total of 4079 genes. GO analysis revealed that those target genes were located in various cellular compartments, including cytoplasm, nucleolus and cell surface, and they were involved in protein-protein or protein-DNA bindings, which influence the signal transductions and gene transcription. Furthermore, pathway enrichment analysis demonstrated that the 72 subspecialized signaling pathways were associated with CCl4-induced liver fibrosis and were mostly classified into metabolic function-related pathways. These results suggest that CCl4 induces liver fibrosis by disrupting the metabolic pathways. In conclusion, we presented several miRNAs and their biological processes that might be important in the progression of liver fibrosis; these findings help increase the understanding of liver fibrogenesis and provide novel ideas for further studies of the role of miRNAs in liver fibrosis.

  19. 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.

  20. Ameliorative effects of 7-methylcoumarin and 7-methoxycoumarin against CCl4-induced hepatotoxicity in rats.

    Science.gov (United States)

    Sancheti, Sandesh; Sancheti, Shruti; Seo, Sung-Yum

    2013-01-01

    The available conventional remedies for the treatment of drug-induced liver diseases are highly inadequate and possess serious adverse effects; therefore, the development of new, effective drugs is considered necessary. This article explores the hepatoprotective and antioxidant potential of 7-methylcoumarin (MC) and 7-methoxycoumarin (MOC) in CCl(4)-induced hepatotoxicity in rats. MC and MOC individually, at doses of 50 and 100 mg/kg body weight, were administered orally once-daily for 7 days. The hepatoprotective activity was assessed using various biochemical parameters, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum bilirubin (TB), total protein (TP), and albumin (TA). Serum antioxidant enzyme [e.g., superoxide dismutase (SOD) and catalase (CAT)] levels were determined. Also, thiobarbituric-acid-related substances (TBARS) levels, along with histopathological studies of liver tissue, were scrutinized. Pretreatment with MC and MOC significantly decreased ALT, AST, and TB in the serum of CCl(4)-induced liver damaged rats in a dose-dependent manner. TA and TP levels in the serum were also restored significantly in all presupplemented MC and MOC groups. In addition, oxidative stress induced by CCl(4) was prevented significantly; thereby, increasing SOD and CAT levels and decreasing TBARS levels in liver homogenates. Histopathological studies revealed the ameliorative natures of both the compounds. This study demonstrates the strong hepatoprotective activity of MC and MOC, which could be attributed to their potent antioxidant effects.

  1. The protective effect of ENA Actimineral resource A on CCl4-induced liver injury in rats.

    Science.gov (United States)

    Hong, Il-Hwa; Ji, Hoon; Hwa, Sung-Yong; Jeong, Won-Il; Jeong, Da-Hee; Do, Sun-Hee; Kim, Ji-Min; Ki, Mi-Ran; Park, Jin-Kyu; Goo, Moon-Jung; Hwang, Ok-Kyung; Hong, Kyung-Sook; Han, Jung-Youn; Chung, Hae-Young; Jeong, Kyu-Shik

    2011-06-01

    ENA Actimineral Resource A (ENA-A) is alkaline water that is composed of refined edible cuttlefish bone and two different species of seaweed, Phymatolithon calcareum and Lithothamnion corallioides. In the present study, ENA-A was investigated as an antioxidant to protect against CCl(4)-induced oxidative stress and hepatotoxicity in rats. Liver injury was induced by either subacute or chronic CCl(4) administration, and the rats had free access to tap water mixed with 0% (control group) or 10% (v/v) ENA-A for 5 or 8 weeks. The results of histological examination and measurement of antioxidant activity showed that the reactive oxygen species production, lipid peroxidation, induction of CYP2E1 were decreased and the antioxidant activity, including glutathione and catalase production, was increased in the ENA-A groups as compared with the control group. On 2-DE gel analysis of the proteomes, 13 differentially expressed proteins were obtained in the ENA-A groups as compared with the control group. Antioxidant proteins, including glutathione S-transferase, kelch-like ECH-associated protein 1, and peroxiredoxin 1, were increased with hepatocyte nuclear factor 3-beta and serum albumin precursor, and kininogen precursor decreased more in the ENA-A groups than compared to the control group. In conclusion, our results suggest that ENA-A does indeed have some protective capabilities against CCl(4)-induced liver injury through its antioxidant function.

  2. Attenuation of CCl4-Induced Oxidative Stress and Hepatonephrotoxicity by Saudi Sidr Honey in Rats

    Directory of Open Access Journals (Sweden)

    Mohammed Al-Yahya

    2013-01-01

    Full Text Available The present study was undertaken to investigate the possible protective effect of Saudi Sidr honey (SSH on carbon tetrachloride (CCl4 induced oxidative stress and liver and kidney damage in rat. Moreover, the antioxidant activity and the phenolic and flavonoidal contents were determined. The hepatorenal protective activity of the SSH was determined by assessing biochemical, hematological, and histological parameters. Serum transaminases, ALP, GGT, creatinine, bilirubin urea, uric acid, and MDA level in liver and kidney tissues were significantly elevated, and the antioxidant status of nonprotein sulfhydryls, albumin, and total protein levels in liver and kidney were declined significantly in CCl4 alone treated animals. Pretreatment with SSH and silymarin prior to the administration of CCl4 significantly prevented the increase of the serum levels of enzyme markers and reduced oxidative stress. SSH also exhibited a significant lipid-lowering effect and caused an HDL-C enhanced level in serum. The histopathological evaluation of the liver and kidney also revealed that honey protected incidence of both liver and kidney lesions. Moreover, SSH showed a strong antioxidant activity in DPPH and β-carotene-linoleic acid assays. SSH was found to contain phenolic compounds. Additionally, the SSH supplementation restored the hepatocytes viability against 2′,7′-dichlorofluorescein (DCF toxicity in ex vivo test.

  3. Protective effect of Sida cordata leaf extract against CCl4 induced acute liver toxicity in rats

    Institute of Scientific and Technical Information of China (English)

    Sunil Mistry; KR Dutt; J Jena

    2013-01-01

    Objective: To investigate the hepatoprotective potential of Sida cordata (Malvaceae) (S. cordata) in experimental rats to validate its traditional claim. Methods: Wister albino rats were divided into 6 groups: Group Ⅰ served as control; Group Ⅱ served as hepatotoxic (CCl4 treated) group;Group Ⅲ, Ⅳ and Ⅴ served as (100, 200 and 400 mg/kg b.w.) S. cordata leaf extract (SCLE) treated groups; Group Ⅵ served as positive control (Silymarin) treated group. Liver marker enzymes serum glutamate oxyloacetic transaminase, serum glutamic pyruvic transaminase, pancreatic enzymatic antioxidants superoxide dismutase (SOD), lipid peroxidation, catalase (CAT), reduced glutathione (GSH) were measured and compared along with histopathological studies. Results:Obtained results show that the treatment with SCLE significantly (P<0.05-<0.001) and dose-dependently reduced CCl4 induced elevated serum level of hepatic enzymes. Furthermore, SCLE significantly (up to P<0.001) reduced the lipid peroxidation in the liver tissue and restored activities of defence antioxidant enzymes GSH, SOD and CAT towards normal levels, which was confirmed by the histopathological studies. Conclusions: The results of this study strongly indicate the protective effect of SCLE against CCl4 induced acute liver toxicity in rats and thereby scientifically support its traditional use.

  4. Hepatoprotective properties of sesamin against CCl4 induced oxidative stress-mediated apoptosis in mice via JNK pathway.

    Science.gov (United States)

    Ma, Jie-Qiong; Ding, Jie; Zhang, Li; Liu, Chan-Min

    2014-02-01

    Sesamin (Ses), one of the major lignan derived from sesame seeds, has been reported to have many benefits and medicinal properties. However, its protective effects against carbon tetrachloride (CCl4) induced injury in liver have not been clarified. The aim of the present study was to investigate the hepatoprotective effects of sesamin on oxidative stress and apoptosis in mice exposed to CCl4. Our data showed that sesamin significantly prevented CCl4-induced hepatotoxicity in a dose-dependent manner, indicated by both diagnostic indicators of liver damage (serum aminotransferase activities) and histopathological analysis. Moreover, CCl4-induced profound elevation of reactive oxygen species (ROS) production and oxidative stress, as evidenced by increasing of lipid peroxidation level and depleting of the total antioxidant capacity (TAC) in liver, were suppressed by treatment with sesamin. Furthermore, TUNEL assay showed that CCl4-induced apoptosis in mouse liver was significantly inhibited by sesamin. In exploring the underlying mechanisms of sesamin action, we found that activities of caspase-3 were markedly inhibited by the treatment of sesamin in the liver of CCl4 treated mice. Sesamin increased expression levels of phosphorylated Jun N-terminal kinases (JNK) in liver, which in turn inactivated pro-apoptotic signaling events restoring the balance between mitochondrial pro- and anti-apoptotic Bcl-2 proteins and decreasing the release of mitochondrial cytochrome c in liver of CCl4 treated mice. JNK was also involved in the mitochondrial extrinsic apoptotic pathways of sesamin effects against CCl4 induced liver injury by regulating the expression levels of phosphorylated c-Jun proteins, necrosis factor-alpha (TNF-α) and Bak. In conclusion, these results suggested that the inhibition of CCl4-induced apoptosis by sesamin is due at least in part to its anti-oxidant activity and its ability to modulate the JNK signaling pathway.

  5. Differential hepatoprotective mechanisms of rutin and quercetin in CCl4-intoxicated BALB/cN mice

    Institute of Scientific and Technical Information of China (English)

    Robert DOMITROVI(C); Hrvoje JAKOVAC; Vanja VASILJEV MARCHESI; Sanda VLADIMIR-KNE(Z)EVI(C); Olga CVIJANOVI(C); (Z)arko TADI(C); (Z)eljko ROMI(C); Dario RAHELI(C)

    2012-01-01

    Aim:To investigate the mechanisms underlying the protective effects of quercetin-rutinoside (rutin) and its aglycone quercetin against CCl4-induced liver damage in mice.Methods:BALB/cN mice were intraperitoneally administered rutin (10,50,and 150 mg/kg) or quercetin (50 mg/kg) once daily for 5 consecutive days,followed by the intraperitoneal injection of CCl4 in olive oil (2 mL/kg,10% v/v).The animals were sacrificed 24 h later.Blood was collected for measuring the activities of ALT and AST,and the liver was excised for assessing Cu/Zn superoxide dismutase (SOD) activity,GSH and protein concentrations and also for immunoblotting.Portions of the livers were used for histology and immunohistochemistry. Results:Pretreatment with rutin and,to a lesser extent,with quercetin significantly reduced the activity of plasma transaminases and improved the histological signs of acute liver damage in CCl4-intoxicated mice.Quercetin prevented the decrease in Cu/Zn SOD activity in CCl4-intoxicated mice more potently than rutin.However,it was less effective in the suppression of nitrotyrosine formation.Quercetin and,to a lesser extent,rutin attenuated the inflammation in the liver by down-regulating the CCl4-induced activation of nuclear factor-kappa B (NF-κB),tumor necrosis factor-α (TNF-α) and cyclooxygenase (COX-2).The expression of inducible nitric oxide synthase (iNOS) was more potently suppressed by rutin than by quercetin.Treatment with both flavonoids significantly increased NF-E2-related factor 2 (Nrf2) and heme oxygenase (HO-1) expression in injured livers,although quercetin was less effective than rutin at an equivalent dose.Quercetin more potently suppressed the expression of transforming growth factor-β1 (TGF-β1) than rutin.Conclusion:Rutin exerts stronger protection against nitrosative stress and hepatocellular damage but has weaker antioxidant and antiinflammatory activities and antifibrotic potential than quercetin,which may be attributed to the presence of a

  6. Hepatoprotective potential of kumaryasava and its concentrate against CCl4-induced hepatic toxicity in Wistar rats

    Science.gov (United States)

    Khan, Mohammad Ahmed; Gupta, Arun; Sastry, J. L. N.; Ahmad, Sayeed

    2015-01-01

    Objective: Kumaryasava (KS) is a marketed Ayurvedic formulation containing Aloe vera as the main ingredient. It has been used widely for the treatment of liver disorders; however, there is a lack of modern scientific data on hepatoprotection. The recommended dose of KS is high and up to 60 mL/day. The present study describes the preparation of new KS concentrate and evaluation of comparative hepatoprotective activity of KS and prepared KS concentrate at one-third of KS dose against CCl4-induced hepatic toxicity. Materials and Methods: Animals were divided into different groups (n = 6). The first group received normal saline (control) 1.0 mL/Kg/day p.o. for 10 days. The second group (toxicant) was given normal saline 1.0 mL/Kg/day p.o. for 10 days with CCl4 in olive oil (1:1 v/v) at 1.0 mL/Kg/day p.o. Third, fourth, and fifth groups received KS, KS concentrate and a marketed formulation as standard) at doses of 5.0 mL/Kg/day p.o., 1.6 mL/Kg/day p.o., and 100 mL/Kg/day p.o. (tablet suspended in water using 0.1% carboxymethyl cellulose) respectively for 10 days along with CCl4 as given to the toxicant group. On the 11th day, blood was withdrawn from retro-orbital plexus and serum was separated for biochemical estimation of serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatase (ALP), and albumin levels. Later, animals were sacrificed under high dose of anesthesia to remove liver tissue, which were removed and washed with ice cold saline for the estimation of lipid peroxidation. Liver tissue from each group was also fixed in 10% formalin for histopathological analysis. Results: Results demonstrated that both KS and KS concentrate showed the protection against CCl4-induced hepatic toxicity. This was evident from the reduction in serum SGOT, SGPT, ALP levels, and elevation in serum albumin levels observed post treatment of CCl4 treated rats with KS and KS concentrate, which were supported by histopathological data

  7. Curcumin or saikosaponin a improves hepatic antioxidant capacity and protects against CCl4-induced liver injury in rats.

    Science.gov (United States)

    Wu, Shu-Ju; Lin, Yun-Ho; Chu, Chia-Chou; Tsai, Ya-Hui; Chao, Jane C-J

    2008-06-01

    Curcumin and saikosaponin a, the bioactive phytochemicals of turmeric and Bupleurum, act as antioxidants. This study investigated the effects of supplementation with curcumin and/or saikosaponin a on hepatic lipids and antioxidant status in rats with CCl(4)-induced liver injury. Male Sprague-Dawley rats were randomly divided into control, CCl(4), CCl(4) + curcumin (0.005%; CU), CCl(4) + saikosaponin a (0.004%; SS), and CCl(4) + curcumin + saikosaponin a (0.005% + 0.004%; CU+SS) groups. CCl(4) (40% in olive oil) was injected intraperitoneally at a dose of 0.75 mL/kg once a week. Curcumin and/or saikosaponin a was administered orally 1 week before CCl(4) injection for 8 weeks. The pathological results showed that liver fibrosis was ameliorated in the SS and CU+SS groups. After 8 weeks, supplementation with curcumin and/or saikosaponin a significantly decreased plasma alanine aminotransferase and aspartate aminotransferase activities, as well as plasma and hepatic cholesterol and triglyceride levels. The CU+SS group showed reversal of the impaired hepatic superoxide dismutase activity and an increase in total glutathione level. Supplementation with curcumin and/or saikosaponin a significantly improved hepatic antioxidant status and suppressed malondialdehyde formation. Therefore, supplementation with curcumin and/or saikosaponin a protects against CCl(4)-induced liver injury by attenuating hepatic lipids and lipid peroxidation and enhancing antioxidant defense. Curcumin and saikosaponin a had no additive effects on hepatoprotection except for greater improvement in the total glutathione level and antioxidant status.

  8. The Protective Effect of Liquorice Plant Extract on CCl4-Induced Hepatotoxicity in Common Carp (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Hassan Malekinejad

    2010-12-01

    Full Text Available The protective effect of liquorice plant extract (LPE on CCl4-induced hepatotoxicity in common carp was evaluated using fifty adult carps. The fish were cultured in a standard environment in terms of water flow rate, oxygen, pH, food and temperature. The fish were assigned into 5 groups (N = 10 as control, sham, and tests. The test groups were pre-treated for 3 h with various concentrations of LPE, 3 days before CCl4 exposure. The control and sham groups received normal saline before and after CCl4 exposure. To induce hepatotoxicity, animals in the sham and test groups were exposed against 100 l L-1 CCl4 for 45 min. The fish in all groups 1 h after CCl4 exposure were anesthetized and the blood samples were collected. Immediately the liver specimens were dissected out and were stored in 10 % formalin for further pathological studies. Determination of serum level of ALP and SGOT revealed that acute form of CCl4 exposure elevated significantly (P < 0.05 the serum level of either tested hepatic marker enzymes. While 3 days pretreatment with LPE prevented from ALP and SGOT enhancement. The pathological evaluation revealed that the CCl4 exposure resulted in a minor pathologic manifestation such as slight congestion, which the LPE pretreated groups showed the remarkable improvement. The anti-oxidant capacity of LPE was assayed by FRAP and DPPH methods. Both provided techniques showed that LPE exerts an excellent anti-oxidant effect. This data suggest that LPE exerts protective effect against CCl4-induced hepatotoxicity. Moreover, the hepatoprotective effect of LPE may attribute to its antioxidant capacity.

  9. Protective effect of Tetracera scandens L. leaf extract against CCl4-induced acute liver injury in rats

    OpenAIRE

    Tung Bui Thanh; Hai Nguyen Thanh; Hue Pham Thi Minh; Huong Le-Thi-Thu; Huong Duong Thi Ly; Loi Vu Duc

    2015-01-01

    Objective: To investigate the protective potential of ethanolic extracts of Tetracera scandens L. (T. scandens) against CCl4 induced oxidative stress in liver tissues. Methods: Dried leaf powder of T. scandens was extracted with ethanol and concentrated to yield a dry residue. Rats were administered with 100 mg/kg of ethanolic extracts orally once daily for one week. Animals were subsequently administered with a single dose of CCl4 (1 mL/kg body weight, intraperitoneal injection). Various ...

  10. [Studies on the metabolic fate of gomisin A (TJN-101). II. Absorption and excretion in CCl4 treated rats].

    Science.gov (United States)

    Matsuzaki, Y; Matsuzaki, T; Ono, H; Koguchi, S; Takeda, S; Takeda, S; Funo, S; Aburada, M; Hosoya, E; Oyama, T

    1991-09-01

    The absorption and excretion of gomisin A (TJN-101) in rats whose livers were injured by carbon tetrachloride (CCl4) were investigated. After intravenous administration of TJN-101 at a dose of 5 mg/kg, the terminal elimination half-life was 1.5 h in the CCl4-treated rats, which was two times that in normal rats. The mean area under the blood concentration-time curve (AUC) value of TJN-101 in the CCl4-treated rats was twice that in normal rats, and this difference was significant (p less than 0.05). Therefore, the total body clearance of TJN-101 in the CCl4-treated rats decreased less than half of that in normal rats. Similar results were observed when it was administered orally. In the CCl4-treated rats, the serum concentration of Met. B, which was identified as a demethylenated substance and one of major metabolites, tended to decrease more than that in normal rats. On the other hand, the cumulative biliary excretion ratio of TJN-101 in 24 h after dosing in the CCl4-treated rats was 2.5 times that in normal rats. The excretion rate of Met. B in the bile in the CCl4-treated rats tended to be delayed. However, the quantitative variance of biliary excretion of Met. B was not found in both groups. The urinary excretion of TJN-101 or Met. B in 72 h after dosing in the CCl4-treated rats was lower than that in normal rats. Similar results were also observed in excretion in the feces.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Protective effect of Tetracera scandens L.leaf extract against CCl4-induced acute liver injury in rats

    Institute of Scientific and Technical Information of China (English)

    Tung; Bui; Thanh; Hai; Nguyen; Thanh; Hue; Pham; Thi; Minh; Huong; Le-Thi-Thu; Huong; Duong; Thi; Ly; Loi; Vu; Duc

    2015-01-01

    Objective:To investigate the protective potential of ethanolic extracts of Tetracera scandens L.(T.scandens) against CCl4 induced oxidative stress in liver tissues.Methods:Dried leaf powder of T.scandens was extracted with ethanol and concentrated to yield a dry residue.Rats were administered with 100 mg/kg of ethanolic extracts orally once daily for one week.Animals were subsequently administered with a single dose of CCl4(I mL/kg body weight,intraperitoneal injection).Various assays,such as serum levels of alanine aminotransferase,aspartate aminotransferase,lipid peroxidation,protein oxidation(carbonyl protein group),tumor necrosis factor alpha,catalase,superoxide dismutase,and glutathione peroxidase,were used to assess damage caused by CCl4 and the protective effects of the ethanol extract on liver tissues.Results:Hepatotoxicity induced by CCl4 was evidenced by a significant increase in serum aspartate aminotransferase and alanine aminotransferase level,lipid peroxidation,protein carbonyl group,and tumor necrosis factor alpha,as well as decreased activity of the hepatic antioxidant enzymes(catalase.superoxide dismutase.and glutathione peroxidase).Treatment with ethanolic T.scandens extracts prevented all of these typically observed changes in CCl4-treated rats.Conclusions:Our findings indicate that T.scandens has a significant protective effect against CCl4 induced hepatotoxicity in rat.which may be due to its antioxidant properties.

  12. Hepatoprotective effects of Lycium chinense Miller fruit and its constituent betaine in CCl4-induced hepatic damage in rats.

    Science.gov (United States)

    Ahn, Meejung; Park, Jong Sang; Chae, Sungwook; Kim, Seungjoon; Moon, Changjong; Hyun, Jin Won; Shin, Taekyun

    2014-07-01

    The hepatoprotective activities of Lycium chinense Miller (LC) fruit extract and its component betaine were investigated under carbon tetrachloride (CCl4)-induced hepatotoxicity in rats. The treatment of LC fruit extract significantly suppressed the increase of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the sera of CCl4 injured rats, and restored the decreased levels of anti-oxidant enzymes such as total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) and suppressed the expression of inflammatory mediators including inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-1 and -2. To visualize the potential activity of betaine, a component of LC fruit, betaine was substituted for LC extract in CCl4 injured rats. The biochemical profile in CCl4 injured rats co-treated with betaine matched those of LC fruit treated CCl4 injured rats. The ameliorative effects of LC extract, as well as betaine, were also confirmed by histopathological examination. Collectively, the present findings imply that LC fruit, via its component betaine, mitigate CCl4-induced hepatic injury by increasing antioxidative activity and decreasing inflammatory mediators including iNOS and COX-1/COX-2.

  13. Ameliorating Effect of Various Fractions of Rumex hastatus Roots against Hepato- and Testicular Toxicity Caused by CCl4

    Directory of Open Access Journals (Sweden)

    Sumaira Sahreen

    2013-01-01

    Full Text Available Effect of methanolic extract of Rumex hastatus roots (MRR and its derived fractions, n-hexane (HRR, ethyl acetate (ERR, chloroform (CRR, butanol (BRR, and aqueous extract (ARR, was studied against carbon tetrachloride (CCl4 induced hepato and testicular toxicity in rats. Intraperitoneal dose of 20 percent CCl4 (0.5 ml/kg bw was administered twice a week for eight weeks to a group of rats. Other groups were given CCl4 and various fractions of R. hastatus roots (200 mg/kg bw. CCl4 treatment depleted glutathione contents and activities of antioxidant enzymes while increased the concentration of lipid peroxides (TBARS along with corresponding DNA injuries and histopathological damages. Supplementation with various fractions of R. hastatus roots (200 mg/kg body weight attenuated the toxicity of CCl4 in liver and testis tissues through improvement in the serological, enzymatic, and histological parameters towards the normal. Posttreatment of R. hastatus roots (200 mg/kg body weight also reversed the alteration in reproductive hormonal secretions and DNA damages in CCl4 treated rats. The results clearly demonstrated that R. hastatus treatment augments the antioxidants defense mechanism and provides the evidence that it may have a therapeutic role in free radical mediated diseases.

  14. Sipa1l1 is an early biomarker of liver fibrosis in CCl4-treated rats

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    Santiago Marfà

    2016-06-01

    Full Text Available At present, several procedures are used for staging liver fibrosis. However, these methods may involve clinical complications and/or present diagnostic uncertainty mainly in the early stages of the disease. Thus, this study was designed to unveil new non-invasive biomarkers of liver fibrosis in an in vivo model of fibrosis/cirrhosis induction by CCl4 inhalation by using a label-free quantitative LC-MS/MS approach. We analyzed 94 serum samples from adult Wistar rats with different degrees of liver fibrosis and 36 control rats. Firstly, serum samples from 18 CCl4-treated rats were clustered into three different groups according to the severity of hepatic and the serum proteome was characterized by label-free LC-MS/MS. Furthermore, three different pooled serum samples obtained from 16 control Wistar rats were also analyzed. Based on the proteomic data obtained, we performed a multivariate analysis which displayed three main cell signaling pathways altered in fibrosis. In cirrhosis, more biological imbalances were detected as well as multi-organ alterations. In addition, hemopexin and signal-induced proliferation-associated 1 like 1 (SIPA1L1 were selected as potential serum markers of liver fibrogenesis among all the analyzed proteins. The results were validated by ELISA in an independent group of 76 fibrotic/cirrhotic rats and 20 controls which confirmed SIPA1L1 as a potential non-invasive biomarker of liver fibrosis. In particular, SIPA1L1 showed a clear diminution in serum samples from fibrotic/cirrhotic rats and a great accuracy at identifying early fibrotic stages. In conclusion, the proteomic analysis of serum samples from CCl4-treated rats has enabled the identification of SIPA1L1 as a non-invasive marker of early liver fibrosis.

  15. THE ROLE OF ENALAPRIL IN PATHOGENESIS OF CCL4 INDUCED HEPATIC FIBROSIS

    Institute of Scientific and Technical Information of China (English)

    魏红山; 李定国; 陆汉明; 展玉涛; 王志荣; 黄新; 徐芹芳

    2001-01-01

    Objective The present study was designed to examine whether the renin-angiotensin system would be implicated in the development of hepatic fibrosis induced by CCl4. The effects of enalapril on the expression of platelet derived growth factor receptor (PDGFR) in liver tissue were also investigated. Methods 50 Sprague-Dawley rats were randomly divided into 5 groups (control group, model group, and 3 enalapril treated groups ). Except rats of the model group, all rats received subcutanous injection of 40% CCl4 (every 3d for 6 weeks). Rats of enalapril treated groups were given enalapril (10mg/kg, 5mg/kg, 2.5mg/kg per day, orally) for 6 weeks before they were killed. Serum levels of hyaluronic acid (HA) and laminin ( LN) were deterrnined by radioimmunoassay techniques. Van Gieson collagen staining was used to evaluate the extracellular matrix of the liver. The expressions of PDGFR and a-smooth muscle actin ( α-SMA ) were confirmed by immunohistochemical methods. Results Compared with those in the model group, it was found in enalapril treated groups: (1) serum levels of collagen type Ⅳ and LN were significantly reduced (P<0.01); (2) the progression of fibrosis was delayed (P<0.01); (3) the expressions of PDGFR and a-SMA were decreased. Conclusion The renin-angiotensin system was involved in the development of hepatic fibrosis induced by CCl4. Angiotensin-converting enzyme (ACE) inhibitor and enalapril could slow down the rate of hepatic fibrosis. This effect might be due to the ability of this drug in suppressing the expression of PDGFR of liver tissue.

  16. Embryonic stem cells develop into hepatocytes after intrasplenic transplantation in CCl4-treated mice

    Institute of Scientific and Technical Information of China (English)

    Kei Moriya; Masahide Yoshikawa; Ko Saito; Yukiteru Ouji; Mariko Nishiofuku; Noriko Hayashi; Shigeaki Ishizaka; Hiroshi Fukui

    2007-01-01

    AIM: To transplant undifferentiated embryonic stem (ES) cells into the spleens of carbon tetrachloride (CCl4)-treated mice to determine their ability to differentiate into hepatocytes in the liver.METHODS: CCU, 0.5 mL/kg body weight, was injected into the peritoneum of C57BL/6 mice twice a week for 5 wk. In group 1 (n = 12), 1 x 105 undifferentiated ES cells (0.1 mL of 1 x 106/mL solution), genetically labeled with GFP, were transplanted into the spleens 1 d after the second injection. Group 2 mice (n = 12) were injected with 0.2 mL of saline twice a week, instead of CCU, and the same amount of ES cells was transplanted into the spleens. Group 3 mice (n = 6) were treated with CCU and injected with 0.1 mL of saline into the spleen, instead of ES cells. Histochemical analyses of the livers were performed on post-transplantation d (PD) 10, 20, and 30.RESULTS: Considerable numbers of GFP-immunopositive cells were found in the periportal regions in group 1 mice (CCl4-treated) on PD 10, however, not in those untreated with CCl4 (group 2). The GFP-positive cells were also immunopositive for albumin (ALB), alpha-1 antitrypsin, cytokeratin 18, and hepatocyte nuclear factor 4 alpha on PD 20. Interestingly, most of the GFP-positive cells were immunopositive for DLK, a hepatoblast marker, on PD 10. Although very few ES-derived cells were demonstrated immunohistologically in the livers of group 1 mice on PD 30, improvements in liver fibrosis were observed. Unexpectedly, liver tumor formation was not observed in any of the mice that received ES cell transplantation during the experimental period.CONCLUSION: Undifferentiated ES cells developed into hepatocyte-like cells with appropriate integration into tissue, without uncontrolled cell growth.

  17. Antioxidant Potential of Plumieride against CCl4-Induced Peroxidative Damage in Rats

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    Dharmendra Singh

    2014-11-01

    Full Text Available In search of a new potent as an antioxidant from natural sources, plumieride—an iridoid isolated from the methanol extract of the bark of Plumeria bicolor (family Apocynaceae was evaluated for its antioxidant potential against CCl4-induced peroxidative damage in liver of rats. The antioxidant potential was evaluated by using hepatic tissue for SOD (superoxide dismutase, CAT (catalase, GSH (reduced glutathione, GPx (glutathione peroxidase, GR (glutathione reductase and LPO (lipid peroxidation alongwith the concomitant blood serum for AST & ALT (aspartate and alanine transaminases, GGT (gamma glutamyl transpeptidase, ALP (alkaline phosphatase, total bilirubin and total protein contents. All the biochemical parameters were significantly (p ≤ 0.001 altered by CCl4 (0.3 mL/kg body weight/twice a week, intra-peritoneally for 30 days. Simultaneously, oral treatment with plumieride (5, 10 and 20 mg/kg body weight/day for 30 days, restored all the parameters towards a normal level, remarkably. The histological findings of liver sections further corroborated the antioxidant potential of plumieride compared with standard drug-silymarin. In conclusion, plumieride consists of sugar molecules, which have alcoholic groups. Therefore, the alcoholic groups of sugar increase its antioxidant potential through intermolecular hydrogen bonding along with the thiol(SH group of non-protein thiols and enzymes resulting in the restoration of the antioxidant system. Therefore, it might be considered a natural antioxidant against peroxidative damage in rats.

  18. Protective effects of Carissa opaca fruits against CCl4-induced oxidative kidney lipid peroxidation and trauma in rat

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    Sumaira Sahreen

    2015-09-01

    Full Text Available Background: Carbon tetrachloride (CCl4 is a potent nephrotoxin, as it causes acute as well as chronic toxicity in kidneys. Therefore, this study was carried out to assess the pharmacological potential of different fractions of Carissa opaca fruits on CCl4-induced oxidative trauma in the kidney. Methods: The parameters studied in this respect were the kidney function tests viz, serum profile, urine profile, genotoxicity, characteristic morphological findings, and antioxidant enzymatic level of kidneys. Result: The protective effects of various fractions of C. opaca fruits against CCl4 administration were reviewed by rat renal function alterations. Chronic toxicity caused by 8-week treatment of CCl4 to the rats significantly decreased the pH level, activities of antioxidant enzymes, and glutathione contents, whereas a significant increase was found in the case of specific gravity, red blood cells, white blood cells, level of urea, and lipid peroxidation in comparison to control group. Administration of various fractions of C. opaca fruit with CCl4 showed protective ability against CCl4 intoxication by restoring the urine profile, activities of antioxidant enzymes, and lipid peroxidation in rat. CCl4 induction in rats also caused DNA fragmentation and glomerular atrophy by means of dilation, disappearance of Bowmen's space, congestion in the capillary loops, dilation in renal tubules, and foamy look of epithelial cells of tubular region, which were restored by co-admiration of various fractions of C. opaca. Conclusion: Results revealed that the methanolic fractions of C. opaca are the most potent and helpful in kidney trauma.

  19. Effect of leaf extracts of Taraxacum officinale on CCl4 induced hepatotoxicity in rats, in vivo study.

    Science.gov (United States)

    Gulfraz, Muhammad; Ahamd, Dawood; Ahmad, Muhammad Sheeraz; Qureshi, Rehmatullah; Mahmood, Raja Tahir; Jabeen, Nyla; Abbasi, Kashif Sarfraz

    2014-07-01

    Taraxacum officinale L is a medicinal plant, which has enormous medicinal values against various types of liver disorders and it has traditionally been used for the treatment of liver problems by people from the South East Asia. Previously we have screened the crude methanolic extract of T. officinale against cytotoxicity induced by CCl4. Present study was designed to compare the protective effect of ethanolic and n-hexane extract of leaves in carbon tetrachloride (CCl4) induced liver toxicity in rats. The extract (200 mg/kg and 400mg/kg body weight) along with silymarin (100 mg/kg) a standard drug was administered to experimental animals. It was observed that ethanolic plant extract has significantly reduced the negative effect of CCl4 as compared to n-hexane extract and effect of extract was increased with increasing dose level. Although both leaf extracts decreased the concentration of TBARS, H2O2 and nitrite contents which enhance due to CCl4 toxicity but effect was higher in ethanolic extract. The results clearly indicated that Taraxacum officinale ethanolic leaves extract has better protective effect against CCl4 induced liver tissues toxicity. This claim was also supported by histopathological results obtained during this study and this might be due to presence of various polar phytochemicals that might be more prevent in this extract.

  20. Comparative Study of Decomposition of CCl4 in Different Atmosphere Thermal Plasmas

    Institute of Scientific and Technical Information of China (English)

    HUANG Jianjun; GUO Wenkang; XU Ping

    2007-01-01

    Decomposition of carbon tetrachloride was studied theoretically in the most commonly used thermal plasma atmosphere such as H2, N2, O2 and water steam. A code developed by the National Aeronautics and Space Administration (NASA) was adopted to calculate the chemical equilibrium distribution and energy consumption of the decomposition of CCl4 in the H2, N2, O2 and water steam atmosphere thermal plasma respectively, with a temperature range of 500 K to 5000 K. In the neutral condition (H2, N2, atmosphere) formation of solid carbon was observed and in the oxygen-atmosphere (O2 and water steam) solid carbon formation disappeared through controlling the ratio of C/O. This indicates that the formation of polycyclic aromatic hydrocarbons (PAHs) is impossible theoretically. The energy consumption in the N2 atmosphere was much higher than that in the H2, O2 and water steam atmosphere at 1500 K.

  1. Nanodiamond-based nanostructures for coupling nitrogen-vacancy centres to metal nanoparticles and semiconductor quantum dots

    Science.gov (United States)

    Gong, Jianxiao; Steinsultz, Nat; Ouyang, Min

    2016-06-01

    The ability to control the interaction between nitrogen-vacancy centres in diamond and photonic and/or broadband plasmonic nanostructures is crucial for the development of solid-state quantum devices with optimum performance. However, existing methods typically employ top-down fabrication, which restrict scalable and feasible manipulation of nitrogen-vacancy centres. Here, we develop a general bottom-up approach to fabricate an emerging class of freestanding nanodiamond-based hybrid nanostructures with external functional units of either plasmonic nanoparticles or excitonic quantum dots. Precise control of the structural parameters (including size, composition, coverage and spacing of the external functional units) is achieved, representing a pre-requisite for exploring the underlying physics. Fine tuning of the emission characteristics through structural regulation is demonstrated by performing single-particle optical studies. This study opens a rich toolbox to tailor properties of quantum emitters, which can facilitate design guidelines for devices based on nitrogen-vacancy centres that use these freestanding hybrid nanostructures as building blocks.

  2. Attenuation of CCl4-induced hepatic fibrosis in mice by vaccinating against TGF-β1.

    Directory of Open Access Journals (Sweden)

    Xiaobao Fan

    Full Text Available Transforming growth factor β1 (TGF-β1 is the pivotal pro-fibrogenic cytokine in hepatic fibrosis. Reducing the over-produced expression of TGF-β1 or blocking its signaling pathways is considered to be a promising therapeutic strategy for hepatic fibrosis. In this study, we evaluated the feasibility of attenuating hepatic fibrosis by vaccination against TGF-β1 with TGF-β1 kinoids. Two TGF-β1 kinoid vaccines were prepared by cross-linking TGF-β1-derived polypeptides (TGF-β1(25-[41-65] and TGF-β1(30-[83-112] to keyhole limpet hemocyanin (KLH. Immunization with the two TGF-β1 kinoids efficiently elicited the production of high-levels of TGF-β1-specific antibodies against in BALB/c mice as tested by enzyme-linked immunosorbent assay (ELISA and Western blotting. The antisera neutralized TGF-β1-induced growth-inhibition on mink lung epithelial cells (Mv1Lu and attenuated TGF-β1-induced Smad2/3 phosphorylation, α-SMA, collagen type 1 alpha 2 (COL1A2, plasminogen activator inhibitor-1 (PAI-1 and tissue inhibitor of metalloproteinase-1 (TIMP-1 expression in the rat hepatic stellate cell (HSC line, HSC-T6. Vaccination against TGF-β1 with the kinoids significantly suppressed CCl4-induced collagen deposition and the expression of α-SMA and desmin, attenuated hepatocyte apoptosis and accelerated hepatocyte proliferation in BALB/c mice. These results demonstrated that immunization with the TGF-β1 kinoids efficiently attenuated CCl4-induced hepatic fibrosis and liver injury. Our study suggests that vaccination against TGF-β1 might be developed into a feasible therapeutic approach for the treatment of chronic fibrotic liver diseases.

  3. Effect of Yiguanjian decoction on cell differentiation and proliferation in CCl4-treated mice

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ling Wang; Dong-Wei Jia; Hui-Yang Liu; Xiao-Feng Yan; Ting-Jie Ye; Xu-Dong Hu; Bo-Qin Li

    2012-01-01

    AIM:To investigate the cellular mechanisms of action of Yiguanjian (YGJ) decoction in treatment of chronic hepatic injury.METHODS:One group of mice was irradiated,and received enhanced green fluorescent protein (EGFP)-positive bone marrow transplants followed by 13 wk of CCl4 injection and 6 wk of oral YGJ administration.A second group of Institute for Cancer Research mice was treated with 13 wk of CCl4 injection and 6 wk of oral YGJ administration.Liver function,histological changes in the liver,and Hyp content were analyzed.The expression of α-smooth muscle actin (α-SMA),F4/80,albumin (Alb),EGFP,mitogen-activated protein kinase-2 (PKM2),Ki-67,α fetoprotein (AFP),monocyte chemotaxis protein-1 and CC chemokine receptor 2 were assayed.RESULTS:As hepatic damage progressed,EGFP-positive marrow cells migrated into the liver and were mainly distributed along the fibrous septa.They showed a conspicuous coexpression of EGFP with α-SMA and F4/80 but no coexpression with AIb.Moreover,the expression of PKM2,AFP and Ki-67 was enhanced dynamically and steadily over the course of liver injury.YGJ abrogated the increases in the number of bone marrow-derived fibrogenic cells in the liver,inhibited expression of both progenitor and mature hepatocyte markers,and reduced fibrogenesis.CONCLUSION:YGJ decoction improves liver fibrosis by inhibiting the migration of bone marrow cells into the liver as well as inhibiting their differentiation and suppressing the proliferation of both progenitors and hepatocytes in the injured liver.

  4. Group IVA phospholipase A(2) deficiency prevents CCl4-induced hepatic cell death through the enhancement of autophagy.

    Science.gov (United States)

    Ishihara, Keiichi; Kanai, Shiho; Tanaka, Kikuko; Kawashita, Eri; Akiba, Satoshi

    2016-02-26

    Group IVA phospholipase A2 (IVA-PLA2), which generates arachidonate, plays a role in inflammation. IVA-PLA2-deficiency reduced hepatotoxicity and hepatocyte cell death in mice that received a single dose of carbon tetrachloride (CCl4) without any inhibitory effects on CCl4-induced lipid peroxidation. An immunoblot analysis of extracts from wild-type mouse- and IVA-PLA2 KO mouse-derived primary hepatocytes that transiently expressed microtubule-associated protein 1 light chain 3B (LC3) revealed a higher amount of LC3-II, a typical index of autophagosome formation, in IVA-PLA2-deficient cells, suggesting the enhancement of constitutive autophagy. IVA-PLA2 may promote CCl4-induced cell death through the suppression of constitutive autophagy in hepatocytes.

  5. Investigation on improving characteristics of two-cell SBS system with CCl4/C2H5OH liquid mixture

    Institute of Scientific and Technical Information of China (English)

    Hasi Wu-Li-Ji; Lü Li-Qiang; He Wei-Ming

    2007-01-01

    In order to improve the performance of the two-cell stimulated Brillouin scattering(SBS) system,this paper proposes the methods of using mixtures,which require amplifier media to have small absorption rate,and generator media to have high optical breakdown threshold and Brillouin frequency shift equal to that of the amplification media.The characteristics of the two-cell SBS system are studied experimentally by using CCl4 as amplifier medium and CCl4,C2H5OH and CCl4/C2H5OH liquid mixture as generator medium pumped by Nd:YAG Q-switched laser.The obtained results show that liquid mixture in generator cell improves the power load ability,phase conjugation fidelity,energy reflectivity (ER) and ER stability.

  6. Inhibitory effects of saikosaponin-d on CCl4-induced hepatic fibrogenesis in rats

    Institute of Scientific and Technical Information of China (English)

    Shuang-Suo Dang; Bao-Feng Wang; Yan-An Cheng; Ping Song; Zhen-Guo Liu; Zong-Fang Li

    2007-01-01

    AIM: To investigate the suppressive effect of saikosaponin-d (SSd) on hepatic fibrosis in rats induced by CCl4 injections in combination with alcohol and high fat, low protein feeding and its relationship with the expression of nuclear factor-κB (NF-κB), tumor necrosis factor-alpha (TNF-α) and interleukins-6 (IL-6).METHODS: Hepatic fibrosis models were induced by subcutaneous injection of CCl4 at a dosage of 3 mL/kg in rats. At the same time, rats in treatment groups were injected intraperitoneally with SSd at different doses (1.0,1.5 and 2.0 mg/kg) once daily for 6 wk in combination with CCl4, while the control group received olive oil instead of CCl4. At the end of the experiment, rats were anesthetized and killed (except for 8 rats which died during the experiment; 2 from the model group, 3 in high-dose group, 1 in medium-dose group and 2 in lowdose group). Hematoxylin and eosin (HE) staining and Van Gieson staining were used to examine the changes in liver pathology. The levels of alanine aminotransferase (ALT), triglyeride (TG), albumin (ALB), globulin (GLB),hyaluronic acid (HA) and laminin (LN) in serum and the content of hydroxyproline (HYP) in liver were measured by biochemical examinations and radioimmuneoassay,respectively. In addition, the expression of TNF-α and IL-6 in liver homogenate was evaluated by enzymelinked immunosorbent assay (ELISA) and the levels of NF-κBp65 and I-κBα in liver tissue were analyzed by Western blotting.RESULTS: Both histological examination and Van Gieson staining demonstrated that SSd could attenuate the area and extent of necrosis and reduce the scores of liver fibrosis. Similarly, the levels of ALT, TG, GLB, HA, and LN in serum, and the contents of HYP, TNF-α and IL-6 in liver were all significantly increased in model group in comparison with those in control group. Whereas,the treatment with SSd markedly reduced all the above parameters compared with the model group, especially in the medium group (ALT: 412 ± 94

  7. Evaluation of protective effect of Sapindus mukorossi saponin fraction on CCl4-induced acute hepatotoxicity in rats

    Science.gov (United States)

    Rao, M Srinivasa; Asad, B Syed; Fazil, MA; Sudharshan, RD; Rasheed, SA; Pradeep, HA; Aboobacker, S; Thayyil, AH; Riyaz, AK; Mansoor, M; Aleem, MA; Zeeyauddin, K; Narasu, M Lakshmi; Anjum, A; Ibrahim, M

    2012-01-01

    Aim This investigation aimed to assess the hepatoprotective effect of saponin fraction isolated from the fruit pericarp of Sapindus mukorossi on carbon tetrachloride (CCl4)-induced hepatotoxicity. Methods Fruit of S. mukorossi was collected and authenticated, and dried pericarp powder subjected to extraction with cold ethanol (70%) by maceration followed by isolation of total saponin fraction. Hepatoprotective activity was demonstrated in the CCl4-damaged primary monolayer culture. In in vivo studies, pretreatment with total saponin fraction (50,100 and 150 mg/kg per os once a day for 4 days before CCl4 introduction and continued afterward for 3 days) attenuated the CCl4-induced acute increase in serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, and alkaline phosphatase activities and considerably reduced histopathological alterations. Further, saponin fraction reduced thiopentone-induced (4 mg/kg, intraperitoneal) sleeping time in rats. Results Saponin fraction pretreatment improves bromsulphalein clearance and also increases cellular viability. Saponin administration replenished depleted hepatic glutathione and superoxide dismutase by improving the antioxidant status of the liver and liver function enzymes. These effects substantiate protection of cellular phospholipids from peroxidative damage induced by highly reactive toxic intermediate radicals formed during biotransformation of CCl4. Conclusion The above findings lead to the conclusion that the saponin fraction of S. mukorossi has a protective capability both in vitro on primary hepatocyte cultures and in vivo in a rat model of CCl4-mediated liver injury. Hence, we suggest that the inclusion of this S. mukorossi fruit pericarp in the management of liver disorders is justified. PMID:22888266

  8. Mechanism of the Inhibitory Effects of Eucommia ulmoides Oliv. Cortex Extracts (EUCE in the CCl4-Induced Acute Liver Lipid Accumulation in Rats

    Directory of Open Access Journals (Sweden)

    Chang-Feng Jin

    2013-01-01

    Full Text Available Eucommia ulmoides Oliv. (EU has been used for treatment of liver diseases. The protective effects of Eucommia Ulmoides Oliv. cortex extracts (EUCE on the carbon tetrachloride- (CCl4- induced hepatic lipid accumulation were examined in this study. Rats were orally treated with EUCE in different doses prior to an intraperitoneal injection of 1 mg/kg CCl4. Acute injection of CCl4 decreased plasma triglyceride but increased hepatic triglyceride and cholesterol as compared to control rats. On the other hand, the pretreatment with EUCE diminished these effects at a dose-dependent manner. CCl4 treatment decreased glutathione (GSH and increased malondialdehyde (MDA accompanied by activated P450 2E1. The pretreatment with EUCE significantly improved these deleterious effects of CCl4. CCl4 treatment increased P450 2E1 activation and ApoB accumulation. Pretreatment with EUCE reversed these effects. ER stress response was significantly increased by CCl4, which was inhibited by EUCE. One of the possible ER stress regulatory mechanisms, lysosomal activity, was examined. CCl4 reduced lysosomal enzymes that were reversed with the EUCE. The results indicate that oral pretreatment with EUCE may protect liver against CCl4-induced hepatic lipid accumulation. ER stress and its related ROS regulation are suggested as a possible mechanism in the antidyslipidemic effect of EUCE.

  9. Effect of Misgurnus anguillicaudatus Lyophilized Power on Liver Fibrosis Induced by CCl 4 in Mice%泥鳅冻干粉抗CCl4小鼠肝纤维化作用

    Institute of Scientific and Technical Information of China (English)

    张倩; 商萌萌; 凌去非; 刘春宇

    2014-01-01

    To study the effect of Misgurnus anguillicaudatus lyophilized power on liver fibrosis, the model in mice was established by using CCl4. Given different doses of Misgurnus anguillicaudatus lyophilized power, the serum ALT and AST activities and tissue Hyp content were detected. The pathological changes of liver were observed. Results showed that the AST and ALT activities and Hyp levels were significantly decreased (P<0.05) in three doses groups of Misgurnus Anguillicaudatus lyophilized power, compared with the model group. The pathological improvements were observed. The fibrogenesis in liver tissues were markedly reduced and the formation of liver pseudoluboli was alleviated. The Misgurnus anguillicaudatus lyophilized power can prevent the formation of liver fibrosis induced by CCl4 in mice.%采用CCl4小鼠肝纤维化模型,给予不同剂量泥鳅冻干粉,检测小鼠血清中ALT、AST活性及肝组织中羟脯氨酸(Hyp)含量,并观察肝组织病理变化,探讨泥鳅冻干粉抗CCl4小鼠肝纤维化作用。结果表明,与模型组相比,泥鳅粉冻干粉明显降低CCl4诱导的肝纤维化小鼠血清ALT、AST活性,显著降低肝组织Hyp含量(P<0.05)。病理学观察结果,泥鳅粉冻干粉给药组小鼠胶原纤维沉积明显减轻,假小叶结构明显减少。泥鳅冻干粉能预防小鼠肝纤维化的形成,具有抗肝纤维化作用。

  10. Alterations of mast cells and TGF-β1 on the silymarin treatment for CCl4-induced hepatic fibrosis

    Institute of Scientific and Technical Information of China (English)

    Da-Hee Jeong; Gi-Ppeum Lee; Won-Il Jeong; Sun-Hee Do; Hai-Jie Yang; Dong-Wei Yuan; Ho-Yong Park; Kyu-Jong Kim; Kyu-Shik Jeong

    2005-01-01

    AIM: Silymarin is a potent antioxidant, antiinflammatory and anti-fibrogenic agent in the liver, which is mediated by alteration of hepatic Kupffer cell function, lipid peroxidation, and collagen production. Especially, in hepatic fibrogenesis, mast cells are expressed in chronic inflammatory conditions, and promote fibroblast growth and stimulate production of the extracellular matrix by hepatic stellate cells.METHODS: We examined the inhibitory mechanism of silymarin on CCl4-induced hepatic cirrhosis in rats. At 4, 8,and 12 wk, liver tissues were examined histopathologically for fibrotic changes produced by silymarin treatment.RESULTS: In the silymarin with CCl4-treated group,increase of hepatic stellate cells and TGF-β1 production were lower than in the CCl4-treated group at early stages.Additionally, at the late fibrogenic stage, expressions of TGF-β1 were weaker and especially not expressed in hepatocytes located in peripheral areas. Moreover, the number of mast cell in portal areas gradually increased and was dependent on the fibrogenic stage, but those of CCl4+silymarin-treated group decreased significantly.CONCLUSION: Anti-fibrotic and antiinflammatory effects of silymarin were associated with activation of hepatic stellate cells through the expression of TGF-β1 and stabilization of mast cells. These results suggest that silymarin prevent hepatic fibrosis through suppression of inflammation and hypoxia in the hepatic fibrogenesis.

  11. Ameliorative effect of Grewia tenax (Forssk) fiori fruit extract on CCl(4)-induced oxidative stress and hepatotoxicity in rats.

    Science.gov (United States)

    Al-Said, Mansour S; Mothana, Ramzi A; Al-Sohaibani, Mohammed O; Rafatullah, Syed

    2011-01-01

    The ethanol extract of Grewia tenax (GTE) fruit was tested for possible efficacy against carbon tetrachloride (CCl(4)) induced liver toxicity in Wistar albino rats. GTE at doses of 250 and 500 mg/kg were administered orally to CCl(4)-treated rats. Acute toxicity test and sleeping time determination were done with mice. The results showed that oral administration of GTE for 3 wk to rats significantly reduced the CCl(4)-induced elevated levels of serum glutamate oxaloacetate transaminase, glutamate pyruvate transaminase, gamma-glutamyl transferase, alkaline phosphatase, bilirubin, cholesterol, high-density lipoproteins, low-density lipoproteins, very low density lipoproteins, and triglycerides. Moreover, it was found that the treatment with GTE significantly elevated the hemoglobin level in serum and increased the nonprotein sulfhydryl and total protein contents in the liver tissue, and a significant diminution was observed in the CCl(4)-induced elevated levels of malondialdehyde in the liver tissue. The biochemical findings were supported by an evaluation with liver histopathology. Pentobarbital-induced prolongation of narcolepsy in mice was shortened significantly by the extract. The observed hepatoprotective effect is believed to occur due to antioxidant properties of the contents of G. tenax extract, which may provide a new drug to be used for fighting liver diseases and it validates its folkloric use in anemic and other conditions.

  12. [Pharmacotherapeutical efficiency of the dry extract "Ce-god-5" in liver injury induced by CCl4 in white rats].

    Science.gov (United States)

    Dashinamzhilov, Zh B; Turtuev, C D

    2014-01-01

    It has been established that the complex plant remedy "Ce-god-5" possesses the marked hepatoprotective effect in liver injury induced by CCl4 in white rats. The ability to inhibit the processes of lipid peroxidation and stimulate antioxidant system of the body is a basic mechanism of hepatoprotective activity of "Ce-god-5".

  13. Protective effects of polyphenols-enriched extract from Huangshan Maofeng green tea against CCl4-induced liver injury in mice.

    Science.gov (United States)

    Cui, Yanmang; Yang, Xingbin; Lu, Xinshan; Chen, Jinwen; Zhao, Yan

    2014-09-01

    The study was to characterize the polyphenolic composition, antioxidant properties, and hepatoprotective effects of a polyphenols-enriched extract (HMTP) from Huangshan Maofeng green tea. HPLC analysis showed that three predominantly polyphenolic compounds present in HMTP were epigallocatechin (271.2 μg/mg extract), rutin (239.3 μg/mg) and epicatechin (89.3 μg/mg). HMTP was shown to exhibit strong scavenging activities against DPPH, O2(-), and OH, and ferric-reducing antioxidant power in vitro. Administration of HMTP at 200, 400 and 800 mg/kg bw in mice prior to CCl4 injury significantly decreased the CCl4-induced elevation of serum ALT, AST and ALP activities, and prevented an increase in hepatic MDA levels (p<0.05). Mice with HMTP pretreatment displayed a better profile of hepatosomatic index and the improved GSH-Px and SOD activities in the liver, relative to CCl4-intoxicated mice. Liver pathological observation also confirmed the protection on CCl4-caused histological alteration, suggesting that HMTP has potential to be explored as valuable hepatoprotective function food.

  14. A New Oleanolic Acid Derivative against CCl4-Induced Hepatic Fibrosis in Rats

    Directory of Open Access Journals (Sweden)

    Hongjun Xiang

    2017-03-01

    Full Text Available A novel hepatoprotective oleanolic acid derivative, 3-oxours-oleana-9(11, 12-dien-28-oic acid (Oxy-Di-OA, has been reported. In previous studies, we found that Oxy-Di-OA presented the anti-HBV (Hepatitis B Virus activity (IC50 = 3.13 µg/mL. Remarkably, it is superior to lamivudine in the inhibition of the rebound of the viral replication rate. Furthermore, Oxy-Di-OA showed good performance of anti-HBV activity in vivo. Some studies showed that liver fibrosis may affiliate with HBV gene mutations. In addition, the anti-hepatic fibrosis activity of Oxy-Di-OA has not been studied. Therefore, we evaluated the protective effect of Oxy-Di-OA against carbon tetrachloride (CCl4-induced liver injury in rats. Daily intraperitoneally administration of Oxy-Di-OA prevented the development of CCl4-induced liver fibrosis, which was evidenced by histological study and immunohistochemical analysis. The entire experimental protocol lasted nine weeks. Oxy-Di-OA significantly suppressed the increases of plasma aspartate aminotransferase (AST and alanine aminotransferase (ALT levels (p < 0.05. Furthermore, Oxy-Di-OA could prevent expression of transforming growth factor β1 (TGF-β1. It is worth noting that the high-dose group Oxy-Di-OA is superior to bifendate in elevating hepatic function. Compared to the model group, Oxy-Di-OA in the high-dose group and low-dose group can significantly reduce the liver and spleen indices (p < 0.05. The acute toxicity test showed that LD50 and a 95% confidence interval (CIs value of Oxy-Di-OA were 714.83 mg/kg and 639.73–798.73 mg/kg via intraperitoneal injection in mice, respectively. The LD50 value of Oxy-Di-OA exceeded 2000 mg/kg via gavage in mice. In addition, a simple and rapid high performance liquid chromatography-ultraviolet (HPLC-UV method was developed and validated to study the pharmacokinetic characteristics of the compound. After single-dose oral administration, time to reach peak concentration of Oxy-Di-OA (Cmax

  15. Protective effects of gomisin A isolated from Schisandra chinensis against CCl(4)-induced hepatic and renal injury.

    Science.gov (United States)

    Hwang, In Sik; Kim, Jee Eun; Lee, Yong Ju; Kwak, Moon Hwa; Choi, Young Hwan; Kang, Byeong Cheol; Hong, Jin Tae; Hwang, Dae Youn

    2013-04-01

    The aim of the present study was to investigate the protective effects of gomisin A, a lignan compound isolated from Schisandra chinensis, against liver and kidney damage induced by CCl(4) exposure. We assessed alterations in organ weights, levels of serum biochemical indicators, and activation of the caspase-3 and MAPK signaling pathways and carried out histological analysis of liver and kidney tissue in rats pretreated with gomisin A for four days. In the gomisin A/CCl(4)-treated group, only the liver experienced a significant increase in weight, whereas the other organs did not undergo any changes. Five biochemical indicators in serum indicated that liver and kidney toxicity dramatically decreased upon gomisin A pretreatment, although the decrease in ratios varied. Upon histological analysis, the gomisin A/CCl(4)-treated group showed less hepatocellular necrosis, a poorly dilated central vein in the liver section, decreased diameter of the glomerulus, a lower number of capillaries, and a convoluted tubule in the kidney section. Furthermore, the formation of active caspase-3 was inhibited by gomisin A pretreatment in the gomisin A/CCl(4)-treated group, whereas the expression level of Bax protein was slightly increased. Western blot analysis revealed that there were differences between the liver and kidney in terms of activation of the MAPK signaling pathway. In the liver, gomisin A pretreatment increased phosphorylation of three members of the MAPK pathway when compared to that in the vehicle pretreatment group. However, in the kidney, only the phosphorylation level of p38 was elevated upon gomisin A pretreatment, whereas levels of the other two members were decreased. These results suggest that gomisin A induces marked protective effects against hepatic and renal injury induced by CCl(4) exposure through differential regulation of the MAPK signal transduction pathway.

  16. Fast food diet with CCl4 micro-dose induced hepatic-fibrosis –a novel animal model

    Science.gov (United States)

    2014-01-01

    Background Non-alcoholic fatty liver disease (NAFLD) is defined as a spectrum of conditions ranging from hepatocellular steatosis to steatohepatitis and fibrosis, progressing to cirrhosis, which occur in the absence of excessive alcohol use. Several animal models capture aspects of NAFLD but are limited either in their representation of the disease stages or use for development of therapeutics due to the extended periods of time required to develop full histological features. Methods Here, we report the development of a novel rat model for NAFLD that addresses some of these limitations. We used a fast food diet (FFD) and a CCl4 micro dose (0.5 ml/kg B.wt) for 8 weeks in Wistar rats. Serological analyses, gene expression profiling and liver histology studies were conducted to investigate the development of steatosis, steatohepatitis and fibrosis in the FFD-CCl4 model when compared to the individual effects of a FFD or a micro dose of CCl4 in rats. Results The serum biochemical profile of the FFD-CCl4 model showed an increase in liver injury and fibrosis. This was also accompanied by a significant increase in liver triglycerides (TG), inflammation and oxidative stress. Importantly, we observed extensive fibrosis confirmed by: i) increased gene expression of fibrosis markers and, ii) moderate to severe collagen deposition seen as perisinusoidal and bridging fibrosis using H&E, Trichome and Sirius Red staining. Conclusions In summary, we find that the FFD-CCl4 rat model developed NAFLD histological features including, steatosis, inflammation and fibrosis in 8 weeks showing promise as a model that can be used to develop NAFLD therapeutics and liver anti-fibrotics. PMID:24884574

  17. Nanoemulsified ethanolic extract of Pyllanthus amarus Schum & Thonn ameliorates CCl4 induced hepatotoxicity in Wistar rats.

    Science.gov (United States)

    Deepa, V; Sridhar, R; Goparaju, A; Reddy, P Neelakanta; Murthy, P Balakrishna

    2012-11-01

    Phyllanthus amarus (PA) is commonly used in traditional medicine for hepatoprotectivity. The major limitation is that, treatment requires a large quantity of herbal extract for a longer duration. Aim of the present study was to encapsulate ethanolic plant extract for sustained release of constituents in intestine and facilitate maximum absorption. The efficacy was compared for the hepatoprotective activity of nanoencapsulated ethanolic extract of P. amarus (NPA) and PA in carbon tetrachloride (CCl4) induced hepatotoxic male rats. Based on total phenol content (TPC), the loading efficiency of nanocapsules was 89% (pH 7.0) and optimum concentration was 2:18 (mg/mL) for plant extract: olive oil. Scanning electron microscopy (SEM) showed a spherical morphology, photon correlation spectroscopy (PCS) identified mean particle diameter as 213 nm and Fourier transform infrared spectroscopy (FT-IR) revealed that the phytoconstituents were stable. An oral dose of NPA (20 mg/kg body wt.) showed a better hepatoprotective activity than PA (100 mg/kg body wt.) and also repeated dose oral toxicity proved to be safe. These biochemical assessments were supported by rat biopsy examinations. In conclusion, the nanoemulsification method may be applied for poor water-soluble ethanolic herbal extracts to reduce the dosage and time.

  18. Bamboo salt attenuates CCl4-induced hepatic damage in Sprague-Dawley rats.

    Science.gov (United States)

    Zhao, Xin; Song, Jia-Le; Kil, Jeung-Ha; Park, Kun-Young

    2013-08-01

    Bamboo salt, a Korean folk medicine, is prepared with solar salt (sea salt) and baked several times at high temperatures in a bamboo case. In this study, we compared the preventive effects of bamboo salt and purified and solar salts on hepatic damage induced by carbon tetrachloride in Sprague-Dawley rats. Compared with purified and solar salts, bamboo salts prevented hepatic damage in rats, as evidenced by significantly reduced serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase (P Bamboo salt (baked 9×) triggered the greatest reduction in these enzyme levels. In addition, it also reduced the levels of the proinflammatory cytokines interleukin (IL)-6, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α. Histopathological sections of liver tissue demonstrated the protective effect of bamboo salt, whereas sections from animals treated with the other salt groups showed a greater degree of necrosis. We also performed reverse transcription-polymerase chain reaction and western blot analyses of the inflammation-related genes iNOS, COX-2, TNF-α, and IL-1β in rat liver tissues. Bamboo salt induced a significant decrease (~80%) in mRNA and protein expression levels of COX-2, iNOS, TNF-α, and IL-1β, compared with the other salts. Thus, we found that baked bamboo salt preparations could prevent CCl4-induced hepatic damage in vivo.

  19. Optical limiting effect based on stimulated Brillouin scattering in CCl4

    Institute of Scientific and Technical Information of China (English)

    LueZhi-Wei; LueYue-Lan; YangJun

    2003-01-01

    The optical limiting effect based on stimulated Brillouin scattering(SBS) in a nonlinear medium was investigated. We numerically treated the nonlinear propagation process with a theoretical model, which includes the spontansous nature of the initiation of SBS, and obtained optical limiting effect in the process. Energy limiting,pulse reshaping and stabilization have been demonstrated on SBS mechanism with the nonlinear medium CCl4. The input optical signals were Nd:YAG nanosecond laser pulses with width varying from 16ns to 7ns then to 2ns, the relationship between the transmitted signal and launched pump signal was shown. In the experimental regime, the most stable pulse the transmitted signal and launched pump signal was shown. In the experimental regime, the most stable pulse and a superior energy stabilization of the transmitted pulse were obtained when the laser pulse-width became as short as 2ns. For the energy variation of laser pulses in a wide range of 14-88mJ, the output energy was limited in a quite narrow range 4.5-5.5mJ.

  20. Acute toxicity of CCl4 but not of paracetamol induces a transcriptomic signature of fibrosis in precision-cut liver slices

    NARCIS (Netherlands)

    Vatakuti, Suresh; Schoonen, Willem G E J; Elferink, Maria; Groothuis, Geny M M; Olinga, Peter

    2015-01-01

    In rat in vivo, both paracetamol (APAP) and carbon tetrachloride (CCl4) induce liver necrosis, but long-term treatment with CCl4, in contrast to paracetamol, causes liver fibrosis. The aim of this study was to perform transcriptomic analysis to compare the early changes in mRNA expression profiles i

  1. Protective effect of selenium-enriched lactobacillus on CCl4-induced liver injury in mice and its possible mechanisms

    Institute of Scientific and Technical Information of China (English)

    Long Chen; Dao-Dong Pan; Juan Zhou; Ying-Zi Jiang

    2005-01-01

    AIM: To study the protective effects and mechanisms of Se-enriched lactobacillus on liver injury caused by carbon tetrachloride (CCl4) in mice.MWTHODS: Seventy-two ICR mice were randomly divided into four groups: normal group, CCl4-induced model group,low Se-enriched lactobacillus treatment group (L-Se group),and high Se-enriched lactobacillus treatment group (H-Se group). During a 3-wk experimental period, the common complete diet was orally provided daily for normal group and model group, and the mice in L-Se and H-Se groups were given a diet with 2 and 4 mg of organoselenium from Se-enriched lactobacillus per kg feed, respectively. From the 2nd wk of experiment, the model group, L-Se group,and H-Se group received abdominal cavity injection of olive oil solution containing 500 mL/L CCl4 (0.07 mL/100 g body mass) to induce liver injury, and the normal group was given olive oil on every other day for over 2 wk. In the first 2 wk post injection with CCl4, mice in each group were killed. The specimens of blood, liver tissue, and macrophages in abdominal cavity fluid were taken. Then the activities of the following liver tissue injury-associated enzymes including glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as well as malondialdehyde (MDA) content were assayed. Changes of phagocytic rate and phagocytic index in macrophages were observed with Wright-Giemsa stain. Plasma TNF-α level was measured by radioimmunoassay. The level of intracellular free Ca2+ ([Ca2+]i) in hepatocytes was detected under a laser scanning confocal microscope.RESULTS: During the entire experimental period, the AST and ALT activities in liver were greatly enhanced by CCl4 and completely blunted by both low and high doses of Se-enriched lactobacillus. The Se-enriched lactobacillus-protected liver homogenate GSH-Px and SOD activities were higher or significantly higher than those in model group and were close to

  2. Interference effects on (e, 2e) electron momentum profiles: a comparative study for CCl4 and CF4*

    Science.gov (United States)

    Watanabe, Noboru; Katafuchi, Keisuke; Yamazaki, Masakazu; Takahashi, Masahiko

    2016-12-01

    Interference effects on electron momentum density distributions have been studied using electron momentum spectroscopy (EMS) for the three outermost orbitals of CCl4, which are constructed from the Cl 3p nonbonding atomic orbitals. The EMS experiment was conducted in the symmetric noncoplanar geometry at an incident electron energy of 2.0 keV. Interference pattern has then been obtained by dividing the experimental data by distorted-wave-Born-approximation cross section for an isolated Cl 3p atomic orbital. A comparison with the result of our earlier study on CF4 [N. Watanabe, X.-J. Chen, M. Takahashi, Phys. Rev. Lett. 108, 173201 (2012)] has demonstrated that the period of the interference pattern reflects the internuclear distance between the constituent halogen atoms. Furthermore, the present result strongly suggests that distorted-wave effects lead to partial destruction of the interference for CCl4 at large momentum.

  3. sup 5 sup 9 Co NQR study on superconducting Na sub x CoO sub 2 centre dot yH sub 2 O

    CERN Document Server

    Kobayashi, Y; Sato, M

    2003-01-01

    Layered Co oxide Na sub x CoO sub 2 centre dot yH sub 2 O with a superconducting transition temperature T sub c =4.5 K has been studied by sup 5 sup 9 Co NQR. The nuclear spin relaxation rate 1/ sup 5 sup 9 T sub 1 is nearly proportional to temperature T in the normal state. In the superconducting state, it exhibits the coherence peak and decreases with decreasing T below approx 0.8T sub c. Detailed comparison of the 1/T sub 1 T values and the magnetic susceptibilities between Na sub x CoO sub 2 centre dot yH sub 2 O and Na sub x CoO sub 2 implies that the metallic state of the former system is closer to a ferromagnetic phase than that of the latter. These experimental results impose a restriction on the mechanism of the superconductivity.

  4. Hepatoprotective potential of antioxidant potent fraction from Urtica dioica Linn. (whole plant in CCl4 challenged rats

    Directory of Open Access Journals (Sweden)

    Bhuwan Chandra Joshi

    2015-01-01

    Full Text Available The aim of the present study was to isolate hepatoprotective component from Urtica dioica Linn. (whole plant against CCl4-induced hepatotoxicity in-vitro (HepG2 cells and in-vivo (rats model. Antioxidant activity of hydro alcoholic extract and its fractions petroleum ether fraction (PEF, ethyl acetate fraction (EAF, n-butanol fraction (NBF and aqueous fraction (AF were determined by DPPH and NO radicals scavenging assay. Fractions were subjected to in-vitro HepG2 cell line study. Further, the most potent fraction (EAF was subjected to in-vivo hepatoprotective potential against CCl4 challenged rats. The in-vivo hepatoprotective active fraction was chromatographed on silica column to isolate the bioactive constituent(s. Structure elucidation was done by using various spectrophotometric techniques like UV, IR, 1H NMR, 13C NMR and MS spectroscopy. Ethyl acetate fraction (EAF of hydro-alcoholic extract of U. dioica possessed the potent antioxidant activity viz. DPPH (IC50 78.99 ± 0.17 μg/ml and NO (IC50101.39 ± 0.30 μg/ml. The in-vitro HepG2 cell line study showed that the EAF prevented the cell damage. The EAF significantly attenuated the increased liver enzymes activities in serum and oxidative parameters in tissue of CCl4-induced rats, suggesting hepatoprotective and anti-oxidant action respectively. Column chromatography of most potent antioxidant fraction (EAF lead to the isolation of 4-hydroxy-3-methoxy cinnamic acid (ferulic acid which is responsible for its hepatoprotective potential. Hence, the present study suggests that EAF of hydro-alcoholic extract has significant antioxidant and hepatoprotective potential on CCl4 induced hepatotoxicity in-vitro and in-vivo.

  5. Tracer Experimental Study of the Main Conveying Conduits of CCl4 Pollutant in the Qiligou Water Supply Resource

    Institute of Scientific and Technical Information of China (English)

    PEI Zong-ping; HAN Bao-ping; LIU Han-hu; LIANG Zhi; ZHOU Dong-lai; ZHU Xue-qiang

    2007-01-01

    The Ordovician karst groundwater in the Qiligou basin is an important water supply source. This groundwater has been seriously contaminated in recent years by CCl4 from a pesticide plant located in the recharge area. The highest concentration of CCl4 in the groundwater is 3909.2 μg/L. Large scale tracer experiments were carried out to study the conveying conduits for CCl4 in the basin on May 1-6, 2005. Nontoxic, edible glucose was used as a tracer and it was detected by spectrophotometric techniques. Well X-61, located near the pesticide plant in the southern recharge area of the basin, was employed for injecting the tracer. Ten wells widely located in the groundwater runoff area were used as observing and sampling wells. The results show that the migration of the pollutants is controlled by the water hydrodynamic field and by the development of karst conduits. The tracer did not enter the up-drainage wells, X-49 and X-47, near the injection point because the water levels at these wells are higher than at the injection point. The adjacent well X-62 is close to the injection site, but the tracer reached the well after eleven hours. Wells X-43, X-59, X-58, YY-1 and X-57, located in the syncline axis runoff area, are respectively 2.5, 3.5, 4.33, 4.38 and 5.44 kilometers from the injection site. The time for initial appearance of tracer was 4, 4, 2, 6 and 4 hours, respectively. The maximum runoff velocity (well X-58) is over two kilometers per hour, indicating that the karst conduits are well developed along the syncline basin axis. These conduits are the main conveying conduits for groundwater and CCl4. Closer wells were not necessarily the first to receive tracer. This shows the inhomogeneity in karst development which causes complex runoff, and pollutant migration, patterns.

  6. Hepatoprotective effect of flavonol glycosides rich fraction from Egyptian Vicia calcarata Desf. against CCl4-induced liver damage in rats.

    Science.gov (United States)

    Singab, Abdel Nasser B; Youssef, Diaa T A; Noaman, Eman; Kotb, Saeed

    2005-07-01

    The hepatoprotective activity of flavonol glycosides rich fraction (F-2), prepared from 70% alcohol extract of the aerial parts of V. calcarata Desf., was evaluated in a rat model with a liver injury induced by daily oral administration of CCl4 (100 mg/kg, b.w) for four weeks. Treatment of the animals with F-2 using a dose of (25 mg/kg, b.w) during the induction of hepatic damage by CCl4 significantly reduced the indices of liver injuries. The hepatoprotective effects of F-2 significantly reduced the elevated levels of the following serum enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant activity of F-2 markedly ameliorated the antioxidant parameters including glutathione (GSH) content, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), plasma catalase (CAT) and packed erythrocytes glucose-6-phosphate dehydrogenase (G6PDH) to be comparable with normal control levels. In addition, it normalized liver malondialdehyde (MDA) levels and creatinine concentration. Chromatographic purification of F-2 resulted in the isolation of two flavonol glycosides that rarely occur in the plant kingdom, identified as quercetin-3, 5-di-O-beta-D-diglucoside (5) and kaempferol-3, 5-di-O-beta-D-diglucoside (4) in addition to the three known compounds identified as quercetin-3-O-alpha-L-rhamnosyl- (1-->6)-beta-D-glucoside [rutin, 3], quercetin-3-O-beta-D-glucoside [isoquercitrin, 2] and kaempferol-3-O-beta-D-glucoside [astragalin, 1]. These compounds were identified based on interpretation of their physical, chemical, and spectral data. Moreover, the spectrophotometric estimation of the flavonoids content revealed that the aerial parts of the plant contain an appreciable amount of flavonoids (0.89%) calculated as rutin. The data obtained from this study revealed that the flavonol glycosides of F-2 protect the rat liver from hepatic damage induced by CCl4 through inhibition of

  7. Effect of compound rhodiola sachalinensis A Bor on CCl4-induced liver fibrosis in rats and its probable molecular mechanisms

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ling Wu; Wei-Zheng Zeng; Pi-Long Wang; Chun-Tao Lei; Ming-De Jiang; Xiao-Bin Chen; Yong Zhang; Hui Xu; Zhao Wang

    2003-01-01

    AIM: To explore the anti-fibrotic effect of a traditional Chinese medicine, compound rhodiola sachalinensis A Bor on CCl4-induced liver fibrosis in rats and its probable molecular mechanisms.METHODS: Ninety healthy male SD rats were randomly divided into three groups: normal group (n=10), treatment group of compound rhodiola sachalinensis A Bor (n=40) and CCl4-induced model group (n=40). The liver fibrosis was induced by CCl4 subcutaneous injection. Treatment group was administered with compound rhodiola sachalinensis A Bor (0.5 g/kg) once a day at the same time. Then the activities of several serum fibrosis-associated enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST),N-acetyl-beta-D-glucosaminidase (β-NAG) and the levels of serum procollagen Ⅲ (PCⅢ), collagen IV (CIV), hyaluronic acid (HA) were assayed. The histopathological changes were observed with HE, VG and Masson stain. The expression of TGF-β1 mRNA, α1 (I) mRNA and Na+/Ca2+ exchanger (NCX)mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) in situ.RESULTS: Compound rhodiola sachalinensis A Bor significantly reduced serum activities of ALT, AST, β-NAG and decreased the levels of PCⅢ, CIV, HA, improved the liver histopathological changes, inhibited the expression of TGFβ1 mRNA, α(I) mRNA and Na+/Ca2+ exchanger mRNA in rats.CONCLUSION: Compound rhodiola sachalinensis A Bor can intervene in CCl4-induced liver fibrosis in rats, in which potential mechanisms may be decreasing the production of TGF-β1, reducing the production of collagen, preventing the activation of hepatic stellate cell (HSC) and inhibiting the expression of TGF-β1 mRNA, α1(I) mRNA and Na+/Ca2+exchanger mRNA.

  8. Oligonol Ameliorates CCl4-Induced Liver Injury in Rats via the NF-Kappa B and MAPK Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Jeonghyeon Bak

    2016-01-01

    Full Text Available Oxidative stress is thought to be a key risk factor in the development of hepatic diseases. Blocking or retarding the reactions of oxidation and the inflammatory process by antioxidants could be a promising therapeutic intervention for prevention or treatment of liver injuries. Oligonol is a low molecular weight polyphenol containing catechin-type monomers and oligomers derived from lychee fruit. In this study, we investigated the anti-inflammatory effect of oligonol on carbon tetrachloride- (CCl4- induced acute hepatic injury in rats. Oral administration of oligonol (10 or 50 mg/kg reduced CCl4-induced abnormalities in liver histology and serum AST and serum ALT levels. Oligonol treatment attenuated the CCl4-induced production of inflammatory mediators, including TNF-α, IL-1β, cyclooxygenase-2 (COX-2, and inducible nitric oxide synthase (iNOS mRNA levels. Western blot analysis showed that oligonol suppressed proinflammatory nuclear factor-kappa B (NF-κB p65 activation, phosphorylation of extracellular signal-regulated kinase (ERK, c-Jun NH2-terminal kinase (JNK, and p38 mitogen-activated protein kinases (MAPKs as well as Akt. Oligonol exhibited strong antioxidative activity in vitro and in vivo, and hepatoprotective activity against t-butyl hydroperoxide-induced HepG2 cells. Taken together, oligonol showed antioxidative and anti-inflammatory effects in CCl4-intoxicated rats by inhibiting oxidative stress and NF-κB activation via blockade of the activation of upstream kinases including MAPKs and Akt.

  9. Red Sea Suberea mollis Sponge Extract Protects against CCl4-Induced Acute Liver Injury in Rats via an Antioxidant Mechanism

    Directory of Open Access Journals (Sweden)

    Aymn T. Abbas

    2014-01-01

    Full Text Available Recent studies have demonstrated that marine sponges and their active constituents exhibited several potential medical applications. This study aimed to evaluate the possible hepatoprotective role as well as the antioxidant effect of the Red Sea Suberea mollis sponge extract (SMSE on carbon tetrachloride- (CCl4- induced acute liver injury in rats. In vitro antioxidant activity of SMSE was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH assay. Rats were orally administered three different concentrations (100, 200, and 400 mg/kg of SMSE and silymarin (100 mg/kg along with CCl4 (1 mL/kg, i.p., every 72 hr for 14 days. Plasma aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, and total bilirubin were measured. Hepatic malondialdehyde (MDA, reduced glutathione (GSH, nitric oxide (NO, superoxide dismutase (SOD, glutathione peroxidase (GPx, and catalase (CAT were also measured. Liver specimens were histopathologically examined. SMSE showed strong scavenging activity against free radicals in DPPH assay. SMSE significantly reduced liver enzyme activities. Moreover, SMSE significantly reduced hepatic MDA formation. In addition, SMSE restored GSH, NO, SOD, GPx, and CAT. The histopathological results confirmed these findings. The results of this study suggested a potent protective effect of the SMSE against CCl4-induced hepatic injury. This may be due to its antioxidant and radical scavenging activity.

  10. Hepatoprotective potential of ethanolic and aqueous extract of flowers of Sesbania grandiflora (Linn) induced by CCl4

    Institute of Scientific and Technical Information of China (English)

    Ishwer Kale; Mohd Asif Khan; Yusufuddin Irfan; Veerana Goud A

    2012-01-01

    Objective: To investigate the hepatoprotective activity of ethanolic and aqueous extract of Sesbania grandiflora(Linn) flower in CCl4 induced hepatotoxicity models in rats. Methods:The ethanolic and aqueous extract of Sesbania grandiflora (Linn) flower are screened for its hepatoprotective activity in CCl4 (0.5 ml/kg, i.p) induced liver damage in Swiss albino rats at a dose of 200 mg/kg bw. Results: The ethanolic and aqueous extract of Sesbania grandiflora (Linn) flower significantly (P<0.001) decreases the biochemical parameters (SGOT, SGPT, ALP, TP, and TB). Silymarin (25 mg/kg), a known hepatoprotective drug used for comparison exhibited significant activity (P<0.001). The extract did not shown any mortality up to a dose of 2000 g/kg bw. These findings suggest that the ethanolic and aqueous extract of Sesbania grandiflora (Linn) flower (500mg/kg) was effective in bringing about functional improvement of hepatocytes. The healing effect of this extract was also confirmed by histological observations. Conclusions: The ethanolic extract at doses of 250 and 500 mg/kg, p.o. and aqueous extract at a dose of 500 mg/kg, p.o. of Sesbania grandiflora (Linn) flower have significant effect on the liver of CCl4 induced hepatotoxicity animal models.

  11. The ethanolic extract of Juglans sinensis leaves and twigs attenuates CCl4-induced hepatic oxidative stress in rats

    Directory of Open Access Journals (Sweden)

    Heejung Yang

    2015-01-01

    Full Text Available Background: The nuts of Juglans sinensis Dode, walnut tree, are rich in unsaturated fatty acids and bioactive compounds with antioxidant activity on liver damages. However, hepatoprotective activity of the leaves and twigs of J. sinensis have not intensively studied yet. Objective: Hepatoprotective activity of the refined ethanolic extract of J. sinensis (JSE3 was evaluated using carbon tetrachloride (CCl4 intoxicated rats. Materials and Methods: Hepatotoxicity was induced in Sprague Dawley rats by intraperitoneal injection of CCl4 for 6 weeks in the presence or absence of JSE3 (100 and 200 mg/kg body weight. The hepatoprotective activity of JSE3 was assessed by biochemical parameters including plasma aspartate aminotransferase (AST, alanine aminotransferase (ALT, and antioxidant enzymes, such as superoxide dismutase (SOD, glutathione reductase, glutathione peroxide, reduced glutathione and oxidized glutathione, along with histopathological studies on hepatic tissue. Results: JSE3 significantly decreased the elevated levels of AST and ALT and restored the reduced levels of antioxidant enzymes. JSE3 also decreased the amounts of collagen content accumulated by CCl4 intoxication. Conclusion: These results suggested that the refined extract of J. sinensis may have a potential to be developed as a therapeutic agent to treat hepatic diseases, such as fatty liver and hepatic fibrosis.

  12. Hepatoprotective effect of manual acupuncture at acupoint GB34 against CCl4-induced chronic liver damage in rats

    Institute of Scientific and Technical Information of China (English)

    Yun-Kyoung Yim; Hyun Lee; Kwon-Eui Hong; Young-Il Kim; Byung-Ryul Lee; Tae-Han Kim; Ji-Young Yi

    2006-01-01

    AIM: To investigate the hepatoprotective effect of manual acupuncture at Yanglingquan (GB34) on CCl4-induced chronic liver damage in rats.METHODS: Rats were injected intraperitoneally with CCl4 (1 mL/kg) and treated with manual acupuncture using reinforcing manipulation techniques at left GB34(Yanglingquan) 3 times a week for 10 wk. A nonacupoint in left gluteal area was selected as a sham point. To estimate the hepatoprotective effect of manual acupuncture at GB34, measurement of liver index,biochemical assays including serum ALT, AST, ALP and total cholesterol, histological analysis and blood cell counts were conducted.RESULTS: Manual acupuncture at GB34 reduced the liver index, serum ALT, AST, ALP and total cholesterol levels as compared with the control group and the sham acupuncture group. It also increased and normalized the populations of WBC and lymphocytes.CONCLUSION: Manual acupuncture with reinforcing manipulation techniques at left GB34 reduces liver toxicity, protects liver function and liver tissue, and normalizes immune activity in CCl4-intoxicated rats.

  13. Biochemical and molecular modulation of CCl4-induced peripheral and central damage by Tilia americana var. mexicanaextracts.

    Science.gov (United States)

    Coballase-Urrutia, Elvia; Cárdenas-Rodríguez, Noemí; González-García, María Carolina; Núñez-Ramírez, Eithan; Floriano-Sánchez, Esaú; González-Trujano, María Eva; Fernández-Rojas, Berenice; Pedraza-Chaverrí, José; Montesinos-Correa, Hortencia; Rivera-Espinosa, Liliana; Sampieri, Aristides Iii; Carmona-Aparicio, Liliana

    2017-03-01

    Around the world, species from the genus Tilia are commonly used because of their peripheral and central medicinal effects; they are prepared as teas and used as tranquilizing, anticonvulsant, and analgesic agents. In this study, we provide evidence of the protective effects of organic and aqueous extracts (100 mg/kg, i.p.) obtained from the leaves of Tilia americana var. mexicana on CCl4-induced liver and brain damage in the rat. Protection was observed in the liver and brain (cerebellum, cortex and cerebral hemispheres) by measuring the activity of antioxidant enzymes and levels of malondialdehyde (MDA) using spectrophotometric methods. Biochemical parameters were also assessed in serum samples from the CCl4-treated rats. The T. americana var. mexicana leaf extracts provided significant protection against CCl4-induced peripheral and central damage by increasing the activity of antioxidant enzymes, diminishing lipid peroxidation, and preventing alterations in biochemical serum parameters, such as the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), γ-globulin (γ-GLOB), serum albumin (ALB), total bilirubin (BB), creatinine (CREA) and creatine kinase (CK), relative to the control group. Additionally, we correlated gene expression with antioxidant activity in the experimental groups treated with the organic and aqueous Tilia extracts and observed a non-statistically significant positive correlation. Our results provide evidence of the underlying biomedical properties of T. americana var. mexicana that confer its neuro- and hepatoprotective effects.

  14. Biochemical and molecular modulation of CCl4-induced peripheral and central damage by Tilia americana var. mexicana

    Directory of Open Access Journals (Sweden)

    Elvia Coballase-Urrutia

    2017-03-01

    Full Text Available Around the world, species from the genus Tilia are commonly used because of their peripheral and central medicinal effects; they are prepared as teas and used as tranquilizing, anticonvulsant, and analgesic agents. In this study, we provide evidence of the protective effects of organic and aqueous extracts (100 mg/kg, i.p. obtained from the leaves of Tilia americana var. mexicana on CCl4-induced liver and brain damage in the rat. Protection was observed in the liver and brain (cerebellum, cortex and cerebral hemispheres by measuring the activity of antioxidant enzymes and levels of malondialdehyde (MDA using spectrophotometric methods. Biochemical parameters were also assessed in serum samples from the CCl4-treated rats. The T. americana var. mexicana leaf extracts provided significant protection against CCl4-induced peripheral and central damage by increasing the activity of antioxidant enzymes, diminishing lipid peroxidation, and preventing alterations in biochemical serum parameters, such as the levels of aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, γ-globulin (γ-GLOB, serum albumin (ALB, total bilirubin (BB, creatinine (CREA and creatine kinase (CK, relative to the control group. Additionally, we correlated gene expression with antioxidant activity in the experimental groups treated with the organic and aqueous Tilia extracts and observed a non-statistically significant positive correlation. Our results provide evidence of the underlying biomedical properties of T. americana var. mexicana that confer its neuro- and hepatoprotective effects.

  15. In-Vivo Antioxidant activity of ethanolic extract of Mentha pulegium leaf against CCl4 induced toxicity in rats

    Institute of Scientific and Technical Information of China (English)

    Sachin Jain; Dinesh Kumar Jain; Neelam Balekar

    2012-01-01

    Objective: To evaluate the in-vivo antioxidant potential of ethanolic extract of Mentha Pulegium against CCl4 induced toxicity in rats. Methods: Animals were treated with plant extract for 7 days and then toxicity was induced with a single CCl4 intraperitoneal injection. Pre-treatment with 600 mg/kg (p.o.) of ethanolic extract of Mentha Pulegium improved the glutathione, SOD, catalase, and peroxidase levels significantly as compared to control group. Results: The present studies revealed that Mentha Pulegium has significant in-vivo antioxidant activity and can be used to protect tissue from oxidative stress. The result showed that the activities of glutathione, SOD, catalase and peroxidase in group treated with CCl4 declined significantly than that of normal group. Conclusion: Ethanolic extract of Mentha Pulegium in the dose of 600 mg/kg, p.o., has improved the glutathione, SOD, catalase, and peroxidase levels significantly, which were comparable with Liv 52. Based on this study we conclude that Ethanolic extract of MenthaPulegium possesses in vivo antioxidant activity and can be employed in protecting tissue from oxidative stress.

  16. Hepatoprotective potential of ether insoluble phenolic components of n-butanol fraction (EPC-BF of flaxseed against CCl 4 -induced liver damage in rats

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    D M Kasote

    2012-01-01

    Full Text Available Objective: to investigate the hepatoprotective potential of ether insoluble phenolic components of n-butanol fraction (EPC-BF of flaxseed against CCl 4 -induced liver damage in rats. Materials and Methods: Hepatotoxicity was induced to Wistar rats by administration of 0.2% CCl 4 in olive oil (8 mL/kg, i.p. on the seventh day of treatment. Hepatoprotective potential of EPC-BF at doses, 250 and 500 mg/kg, p.o. was assessed through biochemical and histological parameters. Results: EPC-BF and silymarin pretreated animal groups showed significantly decreased activities of Aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP, and level of total bilirubin, elevated by CCl 4 intoxication. Hepatic lipid peroxidation elevated by CCl 4 intoxication were also found to be alleviated at almost normal level in the EPC-BF and silymarin pretreated groups. Histological studies supported the biochemical findings and treatment of EPC-BF at doses 250 and 500 mg/kg, p.o. was found to be effective in restoring CCl 4 -induced hepatic damage. However, EPC-BF did not show dose-dependent hepatoprotective potential. EPC-BF depicted maximum protection against CCl 4 -induced hepatic damage at lower dose 250 mg/kg than higher dose (500 mg/ kg. Conclusion: EPC-BF possesses the significant hepatoprotective activity against CCl 4 induced liver damage, which could be mediated through increase in antioxidant defenses.

  17. Hepatoprotective and antioxidant properties of marine halophyte Luminetzera racemosa bark extract in CCL4 induced hepatotoxicity

    Institute of Scientific and Technical Information of China (English)

    MurugesanGnanadesigan; SundaramRavikumar; SamuelJacobInbaneson

    2011-01-01

    Objective:To identify the hepatoprotective and antioxidant activity of Luminetzera racemosa (L. racemosa )bark extract. Methods:Wistar albino rats were divided into 6 groups:Group 1 served as control;Group 2 served as hepatotoxin (CCL4 treated) group;Group 3 served as positive control (Silymarin) treated groups;Group 4, 5 and 6 served as (100, 200 and 300 mg/kg bw p.o.) L. racemosa bark extract treated groups. Moreover, in vitro antioxidant indexes, including DPPH, hydroxyl radical scavenging activity (HRSA), NO, ferric reducing antioxidant power (FRAP), lipid hydroperoxide (LPO) and super oxide dismutase (SOD) were also analyzed in the bark extract. Results:The results suggested that, the level of serum glutamate oxyloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), alkaline phosphatise (ALP), bilurubin, cholesterol, sugar and lactate dehydrogenase (LDH) were significantly (P<0.05) increased in hepatotoxin treated rats when compared with the control group. But, the maximum reduction of SGOT [(225.36±13.65) IU/L], SGPT [(96.85±17.36) IU/L], ALP [(315.37±17.16) IU/L], bilirubin [(2.97±0.46) mg/dL], cholesterol [(163.73±17.54) mg/dL], sugar [(127.35±27.35) mg/dL] and LDH [(1 784.00±268.36) IU/L] were observed with 300 mg/kg bw of bark extract treated rats. Histopathological scores showed that, no visible changes were observed with high dose (300 mg/kg bw) of bark extract treated rats except mild fatty changes. The in vitro antioxidant assays showed that, the IC50 values were observed as (44.17±6.87)μg/mL, (42.45±2.81)μg/mL, (62.37±3.98)μg/mL, (54.24±3.09)μg/mL, (87.25±5.90)μg/mL and (71.54±5.42)μg/mL for DPPH, HRSA, NO, FRAP, LPO and SOD radical scavenging activities, respectively. Conclusions:The hepatoprotective and antioxidant activities of the bark extract might be to the presence of unique chemical classes such as flavonoids, alkaloids and polyphenols.

  18. Suppressive effects of 17β-estradiol on hepatic fibrosis in CCl4-induced rat model

    Institute of Scientific and Technical Information of China (English)

    Qing-Hua Liu; Ding-Guo Li; Xin Huang; Chun-Hua Zong; Qin-Fang Xu; Han-Ming Lu

    2004-01-01

    AIM: To investigate the pathway via which 17β-estradiol (β-Est) exerts suppressive effects on rat hepatic fibrosis.METHODS: In vivo study was done in CCl4-induced female hepatofibrotic rats. Fibrosis-suppressive effect of β-Est rat models. Six weeks after the treatment, all the rats were sacrificed and specimens of serum or liver tissue were collected for the studies. Serum liver enzymes,fibrosis markers and estradiol levels were determined by standard enzymatic methods, ELISA and RIA, respectively.Degrees of fibrosis and areas of hepatic stellate cells (HSCs) positive for alpha-smooth muscle actin (α-SMA) in the liver were determined by van Gieson (VG) stain and immunohistochemistry.In vitro studies, HSCs were isolated by a combination of pronase-collagenase perfusion and density gradient centrifugation. First-passage HSCs were randomly divided into 10 groups, and different concentrations of β-Est, 2-hydroxyestradiol (2OHE) or 2-methoxyestradiol (2MeOE) were separately added to the cell groups. After incubation for 72 h, the degree of cell proliferation, collagen production, α-SMA or estrogen receptor (ER) expression was determined by MTT assay, ELISA and immunohistochemistry,respectively.RESULTS: β-Est treatment reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), hyaluronic acid (HA) and type Ⅳ collagen (C Ⅳ) in sera, suppressed hepatic collagen content, decreased the areas of HSCs positive for α-SMA significantly in both intact and ovariectomized female hepatofibrotic rats. There was a negative correlation between the percentage of fibrotic area of liver tissue and the serum estradiol level; the calculated correlation coefficient was -0.57 (P<0.01). β-Est and its metabolites concentration-dependently (10-9 mol/L-10-7 mol/L) inhibited HSC proliferation and collagen synthesis. At the concentration of 10-7 mol/L, they could inhibit α-SMA expression. The order of potency was 2MeOE>2OHE>β-Est.CONCLUSION: β-Est may suppress

  19. Hepatocurative potential of Vitex doniana root bark, stem bark and leaves extracts against CCl4-induced liver damage in rats

    Institute of Scientific and Technical Information of China (English)

    James Dorcas Bolanle; Kadejo Olubukola Adetoro; Sallau Abdullahi Balarabe; Owolabi Olumuyiwa Adeyemi

    2014-01-01

    Objective: To evaluate the hepatocurative effects of aqueous root bark, stem bark and leaves ofVitex doniana in carbon tetrachloride (CCl albino rats.Methods:4) induced liver damage and non induced liver damage were assigned into liver damage and non liver damage groups of 6 rats in a group. The animals in the CCl4 induced liver damage groups, were induced by intraperitoneal injection with a single dose of CCl4 (1 mL/kg body weight) as a 1:1(v/v) solution in olive oil and were fasted for 36 h before the subsequent treatment with aqueous root bark, stem bark and leaves extracts of Vitex doniana and vitamin E as standard drug (100 mg/kg body weight per day) for 21 d, while the animals in the non induced groups were only treated with the daily oral administration of these extracts at the same dose. The administration of CCl4 was done once a week for a period of 3 weeks.Results:There was significant (P<0.05) increase in concentration of all liver marker enzymes, A total of 60 albino rats (36 induced liver damage and 24 non induced liver damage) alanine aminotransferase, aspartate aminotransferase and alkaline aminotransferase (ALT, AST and ALP) and significant (P<0.05) decrease in albumin in the CCl4 induced liver damage control when compared to the normal control. The extracts caused a significant (P<0.05) reduction in the serum activities of liver marker enzymes (ALT, AST and ALP) and a significant (P<0.05) increase in albumin of all the induced treated groups. Only stem bark extract and vitamin E significantly (P<0.05) increased total protein. All the extracts significantly (P<0.05) lowered serum creatinine whereas only root bark extract significantly (P<0.05) lowered serum level of urea in the rats with CCl4 induced liver damage.Conclusion:Hepatocurative study shows that all the plant parts (root bark, stem bark and leaves) possess significant hepatocurative properties among other therapeutic values justifying their use in folklore medicine.

  20. 核苷酸补偿对CCl_4致肝纤维化大鼠血清蛋白和尿酸水平的影响

    Institute of Scientific and Technical Information of China (English)

    朱善良

    2012-01-01

    本研究以添加核苷酸的日粮饲喂四氯化碳(CCl4)致肝纤维化大鼠,测定大鼠血清蛋白和尿酸等生化指标变化,以探讨外源核苷酸对CCl4致肝纤维化的干预作用.结果表明,CCl4组大鼠体重均低于或显著低于C组和CCl4+NTs组;CCl4组血清总蛋白含量显著低于CCl4+NTs组和C组,而CCl4+NTs组与C组之间差异不显著.C组、CCl4组和CCl4+NTs组之间的血清A含量存在显著差异,其中C组最高,CCl4+NTs组次之,CCl4组最低.CCl4组和CCl4+NTs组的血清G含量显著高于与C组,而CCl4+NTs组显著高于CCl4组.CCl4+NTs组和CCl4组的A/G比值显著低于C组,而CCl4组与CCl4+NTs组间无显著差异.CCl4组血清UA水平显著低于CCl4+NTs组和C组,而CCl4+NTs组与C组UA水平基本持平.结果提示,日粮补偿核苷酸引起CCl4致肝纤维化大鼠的血清白蛋白、球蛋白和尿酸等生化指标发生了明显变化,这可能是外源核苷酸干预肝纤维化损伤的重要机制之一.

  1. Protective effect of rhizoma polygoni cuspidati decoction on liver fibrosis induced by CCL4%中药虎杖水煎液对CCL4诱导肝纤维化的保护作用

    Institute of Scientific and Technical Information of China (English)

    杨先振; 赵有亮; 秦红兵

    2011-01-01

    目的 观察虎杖水煎液对四氯化碳(CCL4)诱导肝纤维化的作用.方法 40只大鼠随机均分为正常对照(A)组、肝纤维化模型(B)组、虎杖水煎液低剂量3 g/kg(C)组和高剂量6 g/kg(D)组.10周后,检测血清ALT、AST以及肝纤维化血清标志物透明质酸(HA)与Ⅵ型胶原(C-Ⅳ)水平,测定肝组织匀浆中超氧化物歧化酶(SOD)活性与丙二醛(MDA)含量,并取肝组织做病理形态学检查.结果 与B组相比,C、D组血清ALT、AST、HA和C-Ⅳ水平降低,肝组织中MDA含量减少,而SOD活性增加(P<0.05或P<0.01),肝纤维化的组织学改变亦减轻.结论 虎杖水煎液对CCL4诱导的肝纤维化具有一定保护作用.%Objective To investigate the effect of rhizoma polygoni cuspidati(RPC) decoction on the liver fibrosis induced by carbon tetrachloride ( CCL4 ). Methods Forty rats were equally randomized into four groups of A(normal controls),B(liver fibrosis model),C(liver fibrosis treated with RPC decoction 3 g/kg) and D( liver fibrosis treated with RPC decoction 6 g/kg). After 10 weeks of administration, serum alanine aminotransferase( ALT), aspartate aminotransf erase (AST) and liver fibrosis markers such as hyaluronic acid(HA) and collagen type W(C-IV) were detected, the activity of superoxide dismutase(SOD) and content of malondialdehyde(MDA) in the hepatic homogenates were measured and the changes of pathomorphology were observed by light microscopy. Results Compared with group B.the levels of ALT, AST, HA,C-IV and the content of MDA were decreased, while the activity of SOD was increased (P<0. 05 or P<0. 01) and the histological changes of liver fibrosis were also improved in groups of C and D. Conclusion RPC decoction has a protective effect on the liver fibrosis induced by CCL4.

  2. Hepatoprotective and cytoprotective properties of Hyptis suaveolens against oxidative stress-induced damage by CCl4 and H2O2

    Institute of Scientific and Technical Information of China (English)

    Hadi Ghaffari; Behrouz Jalali Ghassam; HS Prakash

    2012-01-01

    Objective:To investigate capacity of Hyptis suaveolens (H. suaveolens) methanol extract as an antioxidant to protect against carbon tetrachloride (CCl4)-induced oxidative stress, hepatotoxicity in Albino Wistar rats and cytoprotective effect of hydrogen peroxide (H2O2) induced cell death in HepG2 cell line. Methods: Two different doses of methanol extract of H. suaveolens were evaluated for the hepatoprotective activity against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Animals in Group I: served as control, group II:H. suaveolens (100 mL/kg b.w), group III:H. suaveolens (50 mL/kg b.w) + CCl4 (1 mg/kg), group IV:H. suaveolens (100 mL/kg b.w) + CCl4 (1 mL/kg) and group V: CCl4 (1 mL/kg). Histopathologic changes of liver were also evaluated. Cytotoxicity was also determined by 3, (4,5-dimethylthiazol-2-yl)2,5-diphenyl-tetrazolium bromide (MTT) assay. Results:Oral sigle dose treatment of CCl4 produced a marked elevation in the serum levels of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP) and Lactate dehydrogenase (LDH). Histopathological analysis of the liver of CCl4-induced rats revealed marked liver cell necrosis with inflammatory collections that were conformed to increase in the levels of SOD, GSH, GST, GR and LPO. Treatment with H2O2 significantly induced death of HepG2 cell. Pretreatment with H. suaveolens methanol extract inhibited or attenuated H2O2 induced cytotoxicity. Conclusions: This study shows that H. suaveolens methanol extract can be proposed to protect the liver against CCl4-induced oxidative damage in rats and protect the cells against H2O2-induced oxidative damage in HepG2 cells. The hepatoprotective and cytoprotective effects might be correlated with its antioxidant and free radical scavenger effects.

  3. Two side liquid-cooled and passively Q-switched disk oscillator with nanosheets in flowing CCl4

    Science.gov (United States)

    Nie, Rongzhi; She, Jiangbo; Li, Dongdong; Li, Fuli; Peng, Bo

    2016-09-01

    A passively Q-switched and two side liquid-cooled Nd:YAG disk oscillator is demonstrated, which is operated at a pump pulse width of 300 μs and a pump repetition rate of 10 Hz. The coolant flows over the two large surfaces of the disk and will be passed through by laser beam, so it can also serve as a saturable absorber. For the unmodulated laser, the pure CCl4 was employed as coolant and a plane output mirror of 15 % transmission was employed. The maximum output energy of 795 mJ is realized corresponding to the optical-optical efficiency of 27.4 % and the slope efficiency of 30 %; for the graphene Q-switched laser, the CCl4 with graphene nanosheets was employed as coolant and a plane output mirror of 40 % transmission was employed. The maximum output energy of 376 mJ is realized corresponding to the optical-optical efficiency of 13 % and the slope efficiency of 18 %. The maximum average Q-switching repetition rate is 385 kHz, and the minimum average pulse width is 116 ns; for the MoS2 Q-switched laser, the CCl4 with MoS2 nanosheets was employed as coolant and a plane output mirror of 30 % transmission was employed. The maximum output energy of 486 mJ is realized corresponding to the optical-optical efficiency of 17 % and the slope efficiency of 22 %.The maximum average Q-switching repetition rate is 470 kHz, and the minimum average pulse width is 137 ns.

  4. Antioksidan Ekstrak Air Biji Kopi Robusta Lampung dalam Menghambat Degenerasi Sel Hati Tikus Model Hepatitis yang Diinduksi CCL4

    Directory of Open Access Journals (Sweden)

    Asep Sukohar

    2012-09-01

    Full Text Available Liver plays an important role in maintaining homeostasis and is critical for physiological functions of other organs. Morphological changes of the liver will have an impact on changes in liver function and may appear as clinical manifestations. Hepatitis is a serious disorder that causes inflammation of the liver cells and is caused by viruses, chemicals and toxins. Reactions that occur in the form of oxidative stress, free radicals dominant condition of antioxidants. Traditionally coffee is used as an everyday beverage and known as antioxidants because it contains flavonoids (chlorogenic acid. This study aim was to determine the hepatoprotective/antioxidant effect of coffee growing in Pesawaran Lampung, on the description of hepatocyte cell damage in Wistar rats hepatitis model induced with carbon tetrachloride (CCl4. Laboratory experimental research has been conducted in Pharmacology >Department, Faculty Medicine Padjadjaran University Bandung and pathology examinations was performed at the Hospital Abdoel Moeloek Lampung in December 2008–July 2009, using 15 male Wistar rats divided in three groups, the negative control group, positive control as a model of hepatitis, and hepatitis model that received the water extract of robusta coffee beans 25 mg/kgBW/days for 7 days and then received CCl4 induction. The results were analyzed by analysis of variance and independent t test. Administration of water extract of robusta coffee beans can prevented damage to the liver cell degeneration picture from 58.4±7.09 to 34.4±5.85, these results differed significantly (p≤0.05 compared with positive and negative control. In conclusion, water extract of robusta coffee beans has the potential to prevent interference with the effects of liver function as antioxidants in the ra model of hepatitis which has been inducted with CCL4.

  5. Oxymatrine improves intestinal epithelial barrier function involving NF-κB-mediated signaling pathway in CCl4-induced cirrhotic rats.

    Directory of Open Access Journals (Sweden)

    Jian-Bo Wen

    Full Text Available Accumulating evidence suggests that intestinal epithelial barrier dysfunction plays an important role in the pathogenesis of hepatic cirrhosis and its complications such as gastrointestinal injury and hepatic encephalopathy. To date, there is no cure for cirrhosis-associated intestinal mucosal lesion and ulcer. This study aimed to investigate the effect of oxymatrine on intestinal epithelial barrier function and the underlying mechanism in carbon tetrachloride (CCl4-induced cirrhotic rats. Thirty CCl4-induced cirrhotic rats were randomly divided into treatment group, which received oxymatrine treatment (63 mg/kg, and non-treatment group, which received the same dose of 5% glucose solution (vehicle. The blank group (n = 10 healthy rats received no treatment. Terminal ileal samples were collected for histopathological examination. The expression level of nuclear factor-κB (NF-κB p65 in ileal tissue was evaluated by immunohistochemistry. The gene and protein expression levels of tumor necrosis factor-α (TNF-α and interleukin 6 (IL-6 in ileal tissues were analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR and enzyme-linked immunosorbent assay (ELISA, respectively. Additionally, plasma endotoxin level was determined. In comparison to the blank group, a significant alteration in the morphology of intestinal mucosal villi in the non-treatment group was observed. The intestinal mucosal villi were atrophic, shorter, and fractured, and inflammatory cells were infiltrated into the lamina propria and muscular layer. Besides, serious swell of villi and loose structure of mucous membrane were observed. Oxymatrine reversed the CCl4-induced histological changes and restored intestinal barrier integrity. Moreover, oxymatrine reduced the protein expression level of NF-κB p65, TNF-α, and IL-6, which were elevated in the vehicle-treated group. In addition, the serum endotoxin level was significantly decreased after oxymatrine treatment in

  6. Effects of Rhus tripartitum fruit extract on CCl4-induced hepatotoxicity and cisplatin-induced nephrotoxicity in rats.

    Science.gov (United States)

    Tlili, Nizar; Feriani, Anouar; Allagui, Mohamed Salah; Saadoui, Ezzeddine; Khaldi, Abdelhamid; Nasri, Nizar

    2016-08-01

    Rhus tripartitum D.C., Anacardiaceae, has traditionally been used in Tunisia against many illnesses. The present study investigates, for the first time, the protective effects of the methanol extract of Rhus tripartitum fruit (MERT) against CCl4-induced hepatotoxicity and cisplatin-induced nephrotoxicty in Wistar rats. ALT, AST, LDH, GGT, creatinin, urea, and uric acid levels were studied. The changes in antioxidant parameters such as malondialdehyde (MDA) and protein carbonyl contents were also determined. The increased levels of MDA (30.97 and 11.50 nmol MDA/mg protein in liver and kidney, respectively) and protein carbonyls (13.4 and 17.95 nmol/mg protein in liver and kidney, respectively) were attenuated by MERT pretreatment (19.35 and 6.1 nmol MDA/mg protein and 9.15 and 12 nmol/mg protein in liver and kidney, respectively). The MERT pretreatment significantly reduced the increased biochemical parameters of liver and kidney caused by CCl4 and cisplatin treatment. The histopathologic observation showed that MERT pretreatment restores the altered tissues. The observed results could be due to the high phenolic content and to MERT's important antioxidant potential. This study supports the hepatoprotective and nephroprotective effects of R. tripartitum.

  7. Accelerated CCl4-induced liver fibrosis in Hjv-/- mice, associated with an oxidative burst and precocious profibrogenic gene expression.

    Directory of Open Access Journals (Sweden)

    Giada Sebastiani

    Full Text Available Hereditary hemochromatosis is commonly associated with liver fibrosis. Likewise, hepatic iron overload secondary to chronic liver diseases aggravates liver injury. To uncover underlying molecular mechanisms, hemochromatotic hemojuvelin knockout (Hjv-/- mice and wild type (wt controls were intoxicated with CCl(4. Hjv-/- mice developed earlier (by 2-4 weeks and more acute liver damage, reflected in dramatic levels of serum transaminases and ferritin and the development of severe coagulative necrosis and fibrosis. These responses were associated with an oxidative burst and early upregulation of mRNAs encoding α1-(I-collagen, the profibrogenic cytokines TGF-β1, endothelin-1 and PDGF and, notably, the iron-regulatory hormone hepcidin. Hence, CCl4-induced liver fibrogenesis was exacerbated and progressed precociously in Hjv-/- animals. Even though livers of naïve Hjv-/- mice were devoid of apparent pathology, they exhibited oxidative stress and immunoreactivity towards α-SMA antibodies, a marker of hepatic stellate cells activation. Furthermore, they expressed significantly higher (2-3 fold vs. wt, p<0.05 levels of α1-(I-collagen, TGF-β1, endothelin-1 and PDGF mRNAs, indicative of early fibrogenesis. Our data suggest that hepatic iron overload in parenchymal cells promotes oxidative stress and triggers premature profibrogenic gene expression, contributing to accelerated onset and precipitous progression of liver fibrogenesis.

  8. Effects of Zwitterionic buffers on sorption of ferrous iron at goethite and its oxidation by CCl4.

    Science.gov (United States)

    Buchholz, Anke; Laskov, Christine; Haderlein, Stefan B

    2011-04-15

    A major factor which controls sorption and oxidation of Fe(II) at the mineral-water interface is pH, hence buffers are commonly used to control pH in experimental studies. Here, we examined the effects of widely used organic buffers (3-morpholinopropane-1-sulfonic acid (MOPS) and 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES)) on Fe(II) uptake and oxidation by CCl(4) in aqueous suspensions of goethite. Significant sorption of these zwitterionic buffers occurred only at Fe(II)-loaded goethite but not at native goethite. The addition of MOPS and HEPES caused substantial release of Fe(II) from goethite, retarded the oxidation of surface-bound Fe(II) by CCl(4) and changed the reaction pathway as indicated by lower yields of CHCl(3). To explore electrostatic and steric contributions of MOPS and HEPES to the observed phenomena we studied sorption and competitive effects of model sorbates (Ca(2+), sulfonates) which suggest the formation of a complex between surface-bound Fe(II) and MOPS or HEPES. Our study shows for the first time that these frequently used zwitterionic organic buffers may interfere significantly with the surface chemistry and thus with redox reactions of Fe(II) at goethite. Hence, kinetic or mechanistic information obtained in such systems requires careful interpretation.

  9. Tyrosine kinase inhibitor BIBF1120 ameliorates inflammation, angiogenesis and fibrosis in CCl4-induced liver fibrogenesis mouse model

    Science.gov (United States)

    Öztürk Akcora, Büsra; Storm, Gert; Prakash, Jai; Bansal, Ruchi

    2017-01-01

    Hepatic fibrosis, a progressive chronic disease mainly caused by hepatitis viral infections, alcohol abuse or metabolic syndrome leading to liver dysfunction and is the growing cause of mortality worldwide. Tyrosine kinase inhibitor BIBF1120 (Nintedanib) has been evaluated in clinical trials for idiopathic pulmonary fibrosis and advanced Hepatocellular carcinoma, but has not been explored for liver fibrosis yet. In this study, we aimed to investigate the therapeutic effects and mechanism of BIBF1120 in liver fibrogenesis. The effects of BIBF1120 were evaluated in TGFβ-activated mouse 3T3 fibroblasts, LX2 cells, primary human hepatic stellate cells (HSCs) and CCl4-induced liver fibrogenesis mouse model. Fibroblasts-conditioned medium studies were performed to assess the paracrine effects on macrophages and endothelial cells. In-vitro in TGFβ-activated fibroblasts, BIBF1120 significantly inhibited expression of major fibrotic parameters, wound-healing and contractility. In vivo in CCl4-induced acute liver injury model, post-disease BIBF1120 administration significantly attenuated collagen accumulation and HSC activation. Interestingly, BIBF1120 drastically inhibited intrahepatic inflammation and angiogenesis. To further elucidate the mechanism of action, 3T3-conditioned medium studies demonstrated increased 3T3-mediated macrophage chemotaxis and endothelial cells tube formation and activation, which was significantly decreased by BIBF1120. These results suggests that BIBF1120 can be a potential therapeutic approach for the treatment of liver fibrosis. PMID:28291245

  10. 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.

  11. Activation of silicon quantum dots and coupling between the active centre and the defect state of the photonic crystal in a nanolaser

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Chen Hang-Qiong; Shu Qin; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    A new nanolaser concept using silicon quantum dots (QDs) is proposed.The conduction band opened by the quantum confinement effect gives the pumping levels.Localized states in the gap due to some surface bonds on Si QDs can be formed for the activation of emission.An inversion of population can be generated between the localized states and the valence band in a QD fabricated by using a nanosecond pulse laser.Coupling between the active centres formed by localized states and the defect states of the two-dimensional (2D) photonic crystal can be used to select the model in the nanolaser.

  12. Ferroelectric TGS ((NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4) under high pressure

    CERN Document Server

    Kobayashi, Y; Furuta, H; Endo, S; Deguchi, K

    2002-01-01

    The ferroelectric transition temperature T sub c of (NH sub 2 CH sub 2 COOH) sub 3 centre dot H sub 2 SO sub 4 (TGS), which is a typical order-disorder-type ferroelectric, was determined by dielectric constant and Raman scattering measurements under high pressure. T sub c increased, passed through a maximum and then decreased slightly with increasing pressure, and then abruptly dropped at about 2.5 GPa, where a transition to a new high-pressure phase was confirmed to exist. A tentative p-T phase diagram was proposed for TGS.

  13. Copy number variation in chemokine superfamily: the complex scene of CCL3L-CCL4L genes in health and disease.

    Science.gov (United States)

    Colobran, R; Pedrosa, E; Carretero-Iglesia, L; Juan, M

    2010-10-01

    Genome copy number changes (copy number variations: CNVs) include inherited, de novo and somatically acquired deviations from a diploid state within a particular chromosomal segment. CNVs are frequent in higher eukaryotes and associated with a substantial portion of inherited and acquired risk for various human diseases. CNVs are distributed widely in the genomes of apparently healthy individuals and thus constitute significant amounts of population-based genomic variation. Human CNV loci are enriched for immune genes and one of the most striking examples of CNV in humans involves a genomic region containing the chemokine genes CCL3L and CCL4L. The CCL3L-CCL4L copy number variable region (CNVR) shows extensive architectural complexity, with smaller CNVs within the larger ones and with interindividual variation in breakpoints. Furthermore, the individual genes embedded in this CNVR account for an additional level of genetic and mRNA complexity: CCL4L1 and CCL4L2 have identical exonic sequences but produce a different pattern of mRNAs. CCL3L2 was considered previously as a CCL3L1 pseudogene, but is actually transcribed. Since 2005, CCL3L-CCL4L CNV has been associated extensively with various human immunodeficiency virus-related outcomes, but some recent studies called these associations into question. This controversy may be due in part to the differences in alternative methods for quantifying gene copy number and differentiating the individual genes. This review summarizes and discusses the current knowledge about CCL3L-CCL4L CNV and points out that elucidating their complete phenotypic impact requires dissecting the combinatorial genomic complexity posed by various proportions of distinct CCL3L and CCL4L genes among individuals.

  14. 苯巴比妥联合 CCl4法建立肝硬化腹水大鼠模型%To establish the model of cirrhotic rats with ascites phenobarbital combined with CCl4 method

    Institute of Scientific and Technical Information of China (English)

    方庆; 王成业; 姚瑶; 王满媛; 许钒

    2015-01-01

    Objective To establish a stable rat model of liver cirrhosis by using carbon tetrachloride combined with Phenobarbital Sodi-um.Methods 35%Phenobarbital Sodium was carried out in SD rats for 7 days to activate hepatic microsomal enzyme P450.From the second week,gradient carbon tetrachloride oil solution was offered by intraperitoneal injection (twice per week for 14 weeks).24 h u-rine of rats was collected and measured at the end time of the trial.HE staining of liver tissue was used to observe pathological process of liver.Results After induced with Phenobarbital Sodium for 7 days and then injected with carbon tetrachloride into abdominal cavity continuously for 13 weeks,a stable rat model of liver cirrhosis could be achieved.Conclusion The procedure is stable and reliable for building liver cirrhosis model,and the model has lower mortality and shorter cycle time than traditional one.%目的:采用苯巴比妥联合四氯化碳构建稳定的肝硬化腹水大鼠模型,为抗肝硬化腹水药物的研究提供有效可靠的动物模型。方法采用苯巴比妥联合CCl4法复制肝硬化腹水大鼠模型。35%苯巴比妥溶液诱导1周,激活肝脏肝药酶P450活性,第二周开始,按梯度腹腔注射CCl4油溶液,每周2次至第14周。实验进行至中后期,收集大鼠24 h尿液,测量尿量;检查腹腔积液量;肝组织HE染色观察肝脏病理进程。结果大鼠经苯巴比妥溶液诱导1周后,连续腹腔注射CCl4油溶液13周,可复制稳定的肝硬化腹水模型。结论该法可建立稳定、可靠的肝硬化腹水模型,比传统模型降低了死亡率,且造模时间缩短。

  15. Resisin stimulates the expression of CCL3 and CCL4 in chondrocytes%抵抗素刺激软骨细胞趋化因子CCL3及CCL4基因表达及机制

    Institute of Scientific and Technical Information of China (English)

    张紫机; 廖威明; 张志奇; 康焱; 杨子波; 侯昌禾; 黄广鑫; 陈蔚深; 盛璞义; 何爱珊; 傅明

    2015-01-01

    BACKGROUND:Previous studies have indicated that resistin stimulates a large set of chemokines in chondrocytes that are known to be important in inflammatory joint lesions. OBJECTIVE:To further investigate the mechanism of co-regulation roles of transcription and post-transcription in the up-regulation of two chemokine genes CCL3 and CCL4 in chondrocytes in response to resistin. METHODS:Human chondrocytes, T/C-28a2 and ATDC5 cels were cultured. The function of resistin on the chemokine genes, and the expression of C/EBPβ, nuclear factor-κB isoforms and chondrogenic specific miRNAs were tested by qPCR. The co-regulation of C/EBPβ and nuclear factor-κB was investigated by nuclear factor-κB inhibitor (IKK-NBD) and C/EBPβ inhibitor (SB303580) treatments, and subcelular localization was detected with or without resistin stimulation. RESULTS AND CONCLUSION:Resistin could increase the expression of chemokine genes independently. Chondrocytes reacted in a non-restrictedly cel-specific manner to resistin; C/EBPβ inhibitor, nuclear factor-κB and some chondrogenic specific miRNAs in a combinatorial manner regulated chemokine gene expression. The activity of C/EBPβ was augmented by a transient increase in activity of nuclear factor-κB, and both transcription factors acted independently on the chemokine genes, CCL3 and CCL4.%背景:既往研究表明抵抗素可刺激软骨细胞产生大量趋化因子,在炎症性关节病变中具重要作用,但具体作用机制未明。  目的:进一步探讨抵抗素刺激软骨细胞趋化因子CCL3及CCL4基因表达上调的机制。  方法:培养人源性软骨细胞,T/C-28a2细胞及ATDC5细胞,采用qPCR检测抵抗素刺激趋化因子基因的作用,C/EBPβ表达,核因子κB亚型及软骨特异性miRNAs。给予核因子κB抑制剂(IKK-NBD)和C/EBPβ抑制剂(SB303580),对C/EBPβ及核因子κB的共同调节作用进行检测。在给予抵抗素刺激或无抵抗素刺激时分别进

  16. Hepatocyte-specific ablation of spermine/spermidine-N1-acetyltransferase gene reduces the severity of CCl4-induced acute liver injury

    Science.gov (United States)

    Barone, Sharon L.; Xu, Jie; Steinbergs, Nora; Schuster, Rebecca; Lentsch, Alex B.; Amlal, Hassane; Wang, Jiang; Casero, Robert A.; Soleimani, Manoocher

    2012-01-01

    Activation of spermine/spermidine-N1-acetyltransferase (SSAT) leads to DNA damage and growth arrest in mammalian cells, and its ablation reduces the severity of ischemic and endotoxic injuries. Here we have examined the role of SSAT in the pathogenesis of toxic liver injury caused by carbon tetrachloride (CCl4). The expression and activity of SSAT increase in the liver subsequent to CCl4 administration. Furthermore, the early liver injury after CCl4 treatment was significantly attenuated in hepatocyte-specific SSAT knockout mice (Hep-SSAT-Cko) compared with wild-type (WT) mice as determined by the reduced serum alanine aminotransferase levels, decreased hepatic lipid peroxidation, and less severe liver damage. Cytochrome P450 2e1 levels remained comparable in both genotypes, suggesting that SSAT deficiency does not affect the metabolism of CCl4. Hepatocyte-specific deficiency of SSAT also modulated the induction of cytokines involved in inflammation and repair as well as leukocyte infiltration. In addition, Noxa and activated caspase 3 levels were elevated in the livers of WT compared with Hep-SSAT-Cko mice. Interestingly, the onset of cell proliferation was significantly more robust in the WT compared with Hep-SSAT Cko mice. The inhibition of polyamine oxidases protected the animals against CCl4-induced liver injury. Our studies suggest that while the abrogation of polyamine back conversion or inhibition of polyamine oxidation attenuate the early injury, they may delay the onset of hepatic regeneration. PMID:22723264

  17. TOP1 and 2, polysaccharides from Taraxacum officinale, attenuate CCl(4)-induced hepatic damage through the modulation of NF-kappaB and its regulatory mediators.

    Science.gov (United States)

    Park, Chung Mu; Youn, Hyun Joo; Chang, Hee Kyung; Song, Young Sun

    2010-05-01

    In this work, we estimate the inhibitory effect of two polysaccharides from Taraxacum officinale (TOP) on CCl(4)-induced oxidative stress and inflammation in Sprague-Dawley rats. TOP1 and 2 (304, 92 mg/kg bw) were administered for 7 days via a stomach sonde, and hepatitis was induced by a single dose of CCl(4) (50% CCl(4)/olive oil; 0.5 mL/kg bw) administration. CCl(4) significantly elevated serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities. Histopathological observation further revealed that CCl(4)-induced moderate levels of inflammatory cell infiltration, centrilobular fatty change, apoptosis, and necrosis. However, TOPs pretreatment markedly decreased AST and ALT activities as well as hepatic lesions. TOPs also increased free radical scavenging activity, as exhibited by a lowered TBARS concentration. TOPs pretreatment also reversed other hepatitis-associated symptoms, including GSH depletion, inhibited anti-oxidative enzyme activities, up-regulation of NF-kappaB and increased expression of its regulatory inflammatory mediators, such as inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta. These results suggest that TOPs have a hepatoprotective effect by modulating inflammatory responses and ameliorating oxidative stress.

  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. Interaction of O2 with CH4, CF4, and CCl4 by Molecular Beam Scattering Experiments and Theoretical Calculations.

    Science.gov (United States)

    Cappelletti, David; Aquilanti, Vincenzo; Bartocci, Alessio; Nunzi, Francesca; Tarantelli, Francesco; Belpassi, Leonardo; Pirani, Fernando

    2016-07-14

    Gas phase collisions of O2 by CH4, CF4, and CCl4 have been investigated with the molecular beam technique by measuring both the integral cross section value, Q, and its dependence on the collision velocity, v. The adopted experimental conditions have been appropriate to resolve the oscillating "glory" pattern, a quantum interference effect controlled by the features of the intermolecular interaction, for all the three case studies. The analysis of the Q(v) data, performed by adopting a suitable representation of the intermolecular potential function, provided the basic features of the anisotropic potential energy surfaces at intermediate and large separation distances and information on the relative role of the physically relevant types of contributions to the global interaction. The present work demonstrates that while O2-CH4 and O2-CF4 are basically bound through the balance between size (Pauli) repulsion and dispersion attraction, an appreaciable intermolecular bond stabilization by charge transfer is operative in O2-CCl4. Ab initio calculations of the strength of the interaction, coupled with detailed analysis of electronic charge displacement promoted by the formation of the dimer, fully rationalizes the experimental findings. This investigation indicates that the interactions of O2, when averaged over its relative orientations, are similar to that of a noble gas (Ng), specifically Ar. We also show that the binding energy in the basic configurations of the prototypical Ng-CF4,CCl4 systems [ Cappelletti , D. ; Chem. Eur. J. 2015 , 21 , 6234 - 6240 ] can be reconstructed by using the interactions in Ng-F and Ng-Cl systems, previously characterized by molecular beam scattering experiments of state-selected halogen atom beams. This information is fundamental to approach the modeling of the weak intermolecular halogen bond. On the basis of the electronic polarizability, this also confirms [ Aquilanti , V. ; Angew. Chem., Int. Ed. 2005 , 44 , 2356 - 2360 ] that O2

  1. Quantum yield of Cl∗ (21/2) production in the gas phase photolysis of CCl4 in the ultraviolet

    Indian Academy of Sciences (India)

    Manish Tak; Manabendra Chandra; Dulal Senapati; Puspendu K Das

    2006-07-01

    In this paper, we have probed the dynamics of chlorine atom production from the gas phase photodissociation of carbon tetrachloride at 222 and 235 nm. The quantum yield, * of Cl∗ (21/2) production has been determined by probing the nascent concentrations of both excited (21/2) and ground state (23/2) chlorine atoms by suitable resonance-enhanced multiphoton ionization (REMPI) detection schemes. Although at the photolysis wavelengths the absorption of carbon tetrachloride is weak, significant amounts of Cl∗ are produced. Surprisingly, the quantum yield of Cl∗ production does not follow the absorption spectrum closely, which gives rise to the possibility of an indirect dissociation mechanism present in CCl4 along with direct dissociation at these ultraviolet wavelengths.

  2. Hepatoprotective effect of Carissa carandas Linn root extract against CCl4 and paracetamol induced hepatic oxidative stress.

    Science.gov (United States)

    Hegde, Karunakar; Joshi, Arun B

    2009-08-01

    Oral pre-treatment with ethanolic extract of the roots of C. carandas (ERCC; 100, 200 and 400 mg/kg, po) showed significant hepatoprotective activity against CCl4 and paracetamol induced hepatotoxicity by decreasing the activities of serum marker enzymes, bilirubin and lipid peroxidation, and significant increase in the levels of uric acid, glutathione, super oxide dismutase, catalase and protein in a dose dependent manner, which was confirmed by the decrease in the total weight of the liver and histopathological examination. Data also showed that ERCC possessed strong antioxidant activity, which may probably lead to the promising hepatoprotective activities of C. carandas root extract. These findings therefore supported the traditional belief on hepatoprotective effect of the roots of C. carandas.

  3. CH3Cl, CH2Cl2, CHCl3, and CCl4: Infrared spectra, radiative efficiencies, and global warming potentials

    Science.gov (United States)

    Wallington, Timothy J.; Pivesso, Bruno Pasquini; Lira, Alane Moura; Anderson, James E.; Nielsen, Claus Jørgen; Andersen, Niels Højmark; Hodnebrog, Øivind

    2016-05-01

    Infrared spectra for the title compounds were measured experimentally in 700 Torr of air at 295 K and systematically modeled in B3LYP, M06-2X and MP2 calculations employing various basis sets. Calibrated infrared spectra over the wavenumber range 600-3500 cm-1 are reported and combined with literature data to provide spectra for use in experimental studies and radiative transfer calculations. Integrated absorption cross sections are (units of cm-1 molecule-1): CH3Cl, 660-780 cm-1, (3.89±0.19)×10-18; CH2Cl2, 650-800 cm-1, (2.16±0.11)×10-17; CHCl3, 720-810 cm-1, (4.08±0.20)×10-17; and CCl4, 730-825 cm-1, (6.30±0.31)×10-17. CH3Cl, CH2Cl2, CHCl3, and CCl4 have radiative efficiencies of 0.004, 0.028, 0.070, and 0.174 W m-2 ppb-1 and global warming potentials (100 year horizon) of 5, 8, 15, and 1775, respectively. Quantum chemistry calculations generally predict larger band intensities than the experimental values. The best agreement with experiments is obtained in MP2(Full) calculations employing basis sets of at least triple-zeta quality augmented by diffuse functions. The B3LYP functional is found ill-suited for calculating vibrational frequencies and infrared intensities of halocarbons.

  4. Chemopreventive effect of Fumaria indica that modulates the oxidant-antioxidant imbalance during N-nitrosodiethylamine and CCl4-induced hepatocarcinogenesis in Wistar rats

    Institute of Scientific and Technical Information of China (English)

    Talib Hussain; Hefazat H Siddiqui; Sheeba Fareed; K Sweety; M Vijayakumar; Chandana V Rao

    2012-01-01

    Objective: To investigation the chemopreventive efficiency of Fumaria indica extract (FIE) on the antioxidant status of N-nitrosodiethylamine (NDEA) and CCl4-induced hepatocarcinogenesis in Wistar rats. Methods: The experimental animals were divided into six groups (n = 6). HCC was induced by single intraperitoneal injection of NDEA in normal saline at a dose of 200 mg/kg body weight followed by weekly subcutaneous injections of CCl4 (3 mL/kg/week) for 6 weeks, as the promoter of carcinogenic effect. After administration of the carcinogen, 200 and 400 mg/kg of FIE were administered orally once a day throughout the study. At the end of 20 weeks, the body weight, liver weight and relative liver weight were measured. The level of hepatic malondialdehyde (MDA) formation, reduced glutathione (GSH) and the activities of antioxidant enzymes viz. CAT, SOD, GPx, and GST in the liver of NDEA and CCL4-treated rats were assessed. Results: Obtained results demonstrated that the cotreatment with FIE (200 and 400 mg/kg) significantly prevented the decrease of the body weight and also increased in relative liver weight caused by NDEA and CCl4 administration. FIE also significantly prevented hepatic malondialdehyde (MDA) formation and reduced glutathione (GSH) in NDEA-treated rats which were dose dependent. Additionally, FIE also markedly increased the activities of antioxidant enzymes such as CAT, SOD, GPx, and GST in the liver of NDEA and CCL4-treated rats. Conclusions: These finding powerfully supports thatFumaria indica exert a chemopreventive effect by reversing the oxidant-antioxidant imbalance during hepatocarcinogenesis induced by NDEA and CCl4.

  5. Structures of human CCL18, CCL3, and CCL4 reveal molecular determinants for quaternary structures and sensitivity to insulin-degrading enzyme.

    Science.gov (United States)

    Liang, Wenguang G; Ren, Min; Zhao, Fan; Tang, Wei-Jen

    2015-03-27

    CC chemokine ligands (CCLs) are 8- to 14-kDa signaling proteins involved in diverse immune functions. While CCLs share similar tertiary structures, oligomerization produces highly diverse quaternary structures that protect chemokines from proteolytic degradation and modulate their functions. CCL18 is closely related to CCL3 and CCL4 with respect to both protein sequence and genomic location, yet CCL18 has distinct biochemical and biophysical properties. Here, we report a crystal structure of human CCL18 and its oligomerization states in solution based on crystallographic and small-angle X-ray scattering analyses. Our data show that CCL18 adopts an α-helical conformation at its N-terminus that weakens its dimerization, explaining CCL18's preference for the monomeric state. Multiple contacts between monomers allow CCL18 to reversibly form a unique open-ended oligomer different from those of CCL3, CCL4, and CCL5. Furthermore, these differences hinge on proline 8, which is conserved in CCL3 and CCL4 but is replaced by lysine in human CCL18. Our structural analyses suggest that a mutation of proline 8 to alanine stabilizes a type 1 β-turn at the N-terminus of CCL4 to prevent dimerization but prevents dimers from making key contacts with each other in CCL3. Thus, the P8A mutation induces depolymerization of CCL3 and CCL4 by distinct mechanisms. Finally, we used structural, biochemical, and functional analyses to unravel why insulin-degrading enzyme degrades CCL3 and CCL4 but not CCL18. Our results elucidate the molecular basis for the oligomerization of three closely related CC chemokines and suggest how oligomerization shapes CCL chemokine function.

  6. Preventive effect of D-002, a mixture of long-chain alcohols from beeswax, on the liver damage induced with CCl4 in rats.

    Science.gov (United States)

    Mendoza, Sarahí; Noa, Miriam; Pérez, Yohani; Mas, Rosa

    2007-06-01

    D-002 is a mixture of higher aliphatic primary alcohols purified from beeswax with antioxidant effects. Acute hepatotoxicity induced with CCl4 in rats has been related to increased hepatic lipid peroxidation and prevented with some antioxidants. This study investigated whether D-002 could prevent the acute CCl4-induced hepatotoxicity in rats. Animals were randomly distributed into four groups: a negative control treated orally with the vehicle and three groups injected with CCl4 (1 mL/kg) and treated orally either with the vehicle (positive control) or with D-002 (25 and 100 mg/kg). Eighteen hours after CCl4 dosing, rats were anesthetized, and livers were removed for histopathological studies. Some portions were taken and homogenized for assessing malondialdehyde (MDA) concentrations. Positive, but not negative, controls showed ballooned cells, swollen hepatocytes, and lipid-included hepatocytes, as well as necrotic areas and inflammatory infiltrates. D-002 (25 and 100 mg/kg) dose-dependently and significantly (P < .01) decreased the frequency of all abnormal liver cell types and increased that of normal hepatocytes compared with the positive controls, not showing necrotic areas or inflammatory infiltrates. D-002 dose-dependently decreased hepatic MDA levels, but only in the highest dose group were these levels significantly lower than in the positive control. In conclusion, D-002 effectively prevented the histological liver disturbances and lowered MDA levels, a marker of cellular lipid peroxidation, in rats treated with CCl4. Since increased liver lipid peroxidation has been postulated as a cause of CCl4-induced liver damage in rats, the preventive effects of D-002 could be due to its antioxidant action, but such a proposal still requires further research.

  7. In vivo antioxidant and hepatoprotective potential of Glycyrrhiza glabra extract on carbon tetra chloride (CCl4 induced oxidative-stress mediated hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Varsha Sharma

    2014-02-01

    Results: The results suggest that, the crude extract of root of G. glabra at the doses of 300 and 600mg/kg body wt. expressed significant hepatoprotective potential against CCl4 induced oxidative stress mediated hepatotoxicity in student ‘t’ test (p [Int J Res Med Sci 2014; 2(1.000: 314-320

  8. 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.

  9. A study to evaluate antioxidant and hepatoprotective activity of aqueous extract of roots of Valeriana wallichii in CCl4 induced hepatotoxicity in rats

    Directory of Open Access Journals (Sweden)

    Shariq Naeem Syed

    2014-04-01

    Conclusion: The aqueous extract of roots of V. Wallichii in a dose of 500 mg/kg offers partial protection against hepatotoxicity produced by CCl4 in albino rats. [Int J Basic Clin Pharmacol 2014; 3(2.000: 354-358

  10. Effect of different levels of marigold (Calendula officinails oil extract on performance, blood parameters and immune response of broiler chickens challenged with CCl4

    Directory of Open Access Journals (Sweden)

    Reyhaneh Vahed

    2016-04-01

    Full Text Available Introduction Although use of antibiotic as growth promoter in poultry and animal nutrition have led to positive effects, researches indicated that antibiotic residues in animal and poultry products caused resistance of bacteria and fungi strains and a resistance to antibiotics as a treatment tool for human diseases. Herbal extracts, probiotics and enzymes are suggested as replacers for antibiotics in animal and poultry nutrition. Plants and their active substances with their variety of functions are used as medicinal plants for years to prevent and treat many diseases in human, animal and poultry. Oil extracts of marigold has many active substances such as saponins, flavonoids and antioxidants and serve as a strong antioxidant to control free radicals. Therefore, the extract of marigold was used to test its curing effects on challenged birds with tetra hydrochloride (CCl4, an inducer for liver damage. Material and methods This experiment was conducted to evaluate the effects of marigold oil extracts (MOE on performance, blood parameters and immune response of broiler chickens in a 42-day period. A total of 200 Ross 308 male broiler chickens were allocated to five dietary treatments with four replicates of 10 birds each. Treatments consisted of 1 control (without marigold extract and CCl4, 2 CCl4, 3-5 150, 300, and 450 mg/kg marigold oil extract as supplement + CCl4 (1 mg/kg body weight. CCl4 was injected intraperitoneally from 21 to 30 days of age in a 2- day intervals. During this period sodium chloride (0.9% was added to control group. At day 33, one chick from each replicate of treatments was selected, and their blood and internal organs were used for different bio assays. Results and Discussion No significant differences detected among treatments for performance. However, the highest and the lowest feed intake at starter and grower periods obtained from the treatments used MOE and control groups, respectively (table 2. The highest and the

  11. Glutamine inhibits CCl4 induced liver fibrosis in mice and TGF-β1 mediated epithelial-mesenchymal transition in mouse hepatocytes.

    Science.gov (United States)

    Shrestha, Nirajan; Chand, Lokendra; Han, Myung Kwan; Lee, Seung Ok; Kim, Chan Young; Jeong, Yeon Jun

    2016-07-01

    Glutamine, traditionally a non-essential amino acid, now has been considered as essential in serious illness and injury. It is a major precursor for glutathione synthesis. However, the anti-fibrotic effect of glutamine and its molecular mechanism in experimental liver fibrosis have not been explored. In the present study we aimed to examine the potential role of glutamine in carbon tetrachloride (CCl4) induced liver fibrosis and TGF-β1 mediated epithelial mesenchymal transition (EMT) and apoptosis in mouse hepatocytes. Liver fibrosis was induced by intraperitoneal injection of CCl4 three times a week for 10 weeks. Glutamine treatment effectively attenuated liver injury and oxidative stress. Collagen content was significantly decreased in liver sections of glutamine treated mice compared to CCl4 model mice. Furthermore, glutamine decreased expression level of α-SMA and TGF-β in liver tissue. Our in vitro study showed that TGF-β1 treatment in hepatocytes resulted in loss of E-cadherin and increased expression of mesenchymal markers and EMT related transcription factor. In addition, TGF-β1 increased the expression of apoptotic markers. However, glutamine interestingly suppressed TGF-β1 mediated EMT and apoptosis. In conclusion, our results suggest that glutamine ameliorates CCl4 induced liver fibrosis and suppresses TGF-β1 induced EMT progression and apoptosis.

  12. Effect of pumpkin seed (Cucurbita pepo) protein isolate on the activity levels of certain plasma enzymes in CCl4-induced liver injury in low-protein fed rats.

    Science.gov (United States)

    Nkosi, C Z; Opoku, A R; Terblanche, S E

    2005-04-01

    The effects of pumpkin seed (Cucurbita pepo) protein isolate on the activity levels of lactate dehydrogenase (LD), alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP) against carbon tetrachloride (CCl4)-induced acute liver injury in low-protein fed rats were investigated. A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl4 intoxication one of the two subgroups was administered with pumpkin seed protein isolate. All three subgroups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all four enzymes were significantly higher than their counterparts on a normal balanced diet. CCl4 intoxication resulted in significant increases in the activity levels of all four enzymes investigated. The administration of pumpkin seed protein isolate after CCl4 intoxication resulted in significantly reduced activity levels of all four enzymes. It is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein malnutrition.

  13. Quantitative Phytochemical Estimation and Evaluation of Hepatoprotective Activity of Methanolic Extract of Dendrobium ovatum (L. Kraenzl. Whole Plant against CCl4 Induced Hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Seru Ganapaty

    2013-09-01

    Full Text Available A large number of populations suffer due to various reasons from hepatic diseases of unknown origin. The development of antihepatotoxic drugs being a major thrust area has drawn the attention of workers in the field of natural product research because synthetic drugs may cause serious side effects. The present research was aimed to study the in vivo hepatoprotective activity of methanolic extract of Dendrobium ovatum (L. Kraenzl. Whole plant, which was used traditionally in Chittoor and Khammam districts of Andhra Pradesh, by carbon tetrachloride (CCl4 induced hepatotoxicity animal model and standard drug silymarin. The level of serum aspartate aminotransferase (SGOT, alanine aminotransferase (SGPT, alkaline phosphatase (ALP and total bilirubin (T. BILI. were determined to assay hepatotoxicity. CCl4 administration caused severe hepatic damage in rats as evidenced by elevated serum SGOT, SGPT, ALP and T. BILI. Levels. The D. ovatum and silymarin administration prevented the toxic effect of CCl4 on the above serum parameters in both preventive and curative models. The present study concludes that, methanolic extract of D. ovatum has significant hepatoprotective activity against CCl4 induced hepatotoxicity, which support folkloric utilization and further confirmed by the histological investigation. The observed activity may be associated with its high bioactive compounds including flavonoids, alkaloids, triterpenoids, glycosides, steroids and carbohydrates.

  14. Essential roles of the interaction between cancer cell-derived chemokine, CCL4, and intra-bone CCR5-expressing fibroblasts in breast cancer bone metastasis.

    Science.gov (United States)

    Sasaki, Soichiro; Baba, Tomohisa; Nishimura, Tatsunori; Hayakawa, Yoshihiro; Hashimoto, Shin-Ichi; Gotoh, Noriko; Mukaida, Naofumi

    2016-08-01

    From a murine breast cancer cell line, 4T1, we established a subclone, 4T1.3, which consistently metastasizes to bone upon its injection into the mammary fat pad. 4T1.3 clone exhibited similar proliferation rate and migration capacity as the parental clone. However, the intra-bone injection of 4T1.3 clone caused larger tumors than that of the parental cells, accompanied with increases in fibroblast, but not osteoclast or osteoblast numbers. 4T1.3 clone displayed an enhanced expression of a chemokine, CCL4, but not its specific receptor, CCR5. CCL4 shRNA-transfection of 4T1.3 clone had few effects on its in vitro properties, but reduced the tumorigenicity arising from the intra-bone injection. Moreover, intra-bone injection of 4T1.3 clone caused smaller tumors in mice deficient in CCR5 or those receiving CCR5 antagonist than in wild-type mice. The reduced tumor formation was associated with attenuated accumulation of CCR5-positive fibroblasts expressing connective tissue growth factor (CTGF)/CCN2. Tumor cell-derived CCL4 could induce fibroblasts to express CTGF/CCN2, which could support 4T1.3 clone proliferation under hypoxic culture conditions. Thus, the CCL4-CCR5 axis can contribute to breast cancer metastasis to bone by mediating the interaction between cancer cells and fibroblasts in bone cavity.

  15. Effects of Biphenyldimethyl-dicarboxylate Administration Alone or Combined with Silymarin in the CCL4 Model of Liver Fibrosis in Rats

    Directory of Open Access Journals (Sweden)

    Omar M. E. Abdel-Salam

    2007-01-01

    Full Text Available The effect of biphenyldimethyldicarboxylate (DDB, a synthetic compound, in use for the treatment of chronic hepatitis was studied on hepatic injury caused in rats by administration of carbon tetrachloride (CCl4. Starting at time of administration of the first dose of CCl4, rats received DDB at four dose levels (3, 15, 75 or 375 mg/kg, silymarin (22 mg/kg, a combination of DDB (75 mg/kg and silymarin (22 mg/kg or saline (control once orally daily for 30 days. The administration of DDB in CCl4-treated rats at 75 or 375 mg/kg resulted in 61.2-76.2% decrease in alanine aminotransferase (ALT and 46.9-60.8% decrease in aspartate aminotransferase (AST, respectively compared with the CCl4 control group. Silymarin treatment resulted in 34.6 and 30% decrease in ALT and AST, while DDB (75 mg/kg combined with silymarin (22 mg/kg resulted in 58.2 and 31% decrease in ALT and AST, respectively. Serum creatinine increased by 50% by DDB at 375 mg/kg. After treatment with DDB at 75 or 375 mg/kg or DDB combined with silymarin, the development of liver necrosis and fibrosis caused by CCl4 was markedly reduced, while after DDB combined with silymarin no DNA aneuploid cells could be observed. The decrease in glycogen and protein contents in hepatocytes caused by CCl4 was markedly prevented by co-treatment with DDB at 75 or 375 mg/kg or DDB combined with silymarin. It is concluded that in the model of hepatic injury caused by chronic administration of CCl4 in rats, the synthetic compound DDB, limits hepatocellular injury and exerts antifibrotic effect. Better improvement in protein, DNA, mucopolysaccharide content was seen after both DDB and silymarin compared to DDB alone. It is suggested, therefore, that DDB alone or in combination with silymarin might prove of benefit in the therapy of chronic liver disease. Monitoring of kidney functions in patients taking DDB is warranted.

  16. Involvement of the TNF and FasL produced by CD11b Kupffer cells/macrophages in CCl4-induced acute hepatic injury.

    Directory of Open Access Journals (Sweden)

    Atsushi Sato

    Full Text Available We previously reported that F4/80(+ Kupffer cells are subclassified into CD68(+ Kupffer cells with phagocytic and ROS producing capacity, and CD11b(+ Kupffer cells with cytokine-producing capacity. Carbon tetrachloride (CCl4-induced hepatic injury is a well-known chemical-induced hepatocyte injury. In the present study, we investigated the immunological role of Kupffer cells/macrophages in CCl4-induced hepatitis in mice. The immunohistochemical analysis of the liver and the flow cytometry of the liver mononuclear cells showed that clodronate liposome (c-lipo treatment greatly decreased the spindle-shaped F4/80(+ or CD68(+ cells, while the oval-shaped F4/80+ CD11b(+ cells increased. Notably, severe hepatic injury induced by CCl4 was further aggravated by c-lipo-pretreatment. The population of CD11b(+ Kupffer cells/macrophages dramatically increased 24 hour (h after CCl4 administration, especially in c-lipo-pretreated mice. The CD11b(+ Kupffer cells expressed intracellular TNF and surface Fas-ligand (FasL. Furthermore, anti-TNF Ab pretreatment (which decreased the FasL expression of CD11b(+ Kupffer cells, anti-FasL Ab pretreatment or gld/gld mice attenuated the liver injury induced by CCl4. CD1d-/- mouse and cell depletion experiments showed that NKT cells and NK cells were not involved in the hepatic injury. The adoptive transfer and cytotoxic assay against primary cultured hepatocytes confirmed the role of CD11b(+ Kupffer cells in CCl4-induced hepatitis. Interestingly, the serum MCP-1 level rapidly increased and peaked at six h after c-lipo pretreatment, suggesting that the MCP-1 produced by c-lipo-phagocytized CD68(+ Kupffer cells may recruit CD11b(+ macrophages from the periphery and bone marrow. The CD11b(+ Kupffer cells producing TNF and FasL thus play a pivotal role in CCl4-induced acute hepatic injury.

  17. 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.

  18. 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.

  19. Anti-apoptotic effect of San Huang Shel Shin Tang cyclodextrin complex (SHSSTc) on CCl4 -induced hepatotoxicity in rats.

    Science.gov (United States)

    Yang, Cheng-Hsun; Ting, Wei-Jen; Shen, Chia-Yao; Hsu, Hsi-Hsien; Lin, Yueh-Min; Kuo, Chia-Hua; Tsai, Fuu-Jen; Tsai, Chang-Hai; Tsai, Yuhsin; Huang, Chih-Yang

    2016-06-01

    The metabolic loading is heavier in liver especially when injured or inflammation. San Huang Shel Shin Tang (SHSST) was an old traditional herbal decoction, which composed with Rheum officinale Baill, Scutellaria baicalnsis Geprgi and Coptis chinensis Franch (1:1:2 in weight), can provide a liver protection effects. We used a beta-cyclodextrin (β-CD) drug modification method in reduce of the necessary dose of the SHSST. As the results, the FAS-FADD expressions leaded apoptosis in CCl4 intraperitoneal (IP) injection induced acute liver injury in rats. Silymarin, baicalein, SHSST, and SHSST β-CD complex (SHSSTc) pretreatments protected liver through the decreasing of the expressions of FAS-FADD and downstream caspase-3 and caspase-8. Particularly, SHSSTc (30 mg/kg day) treatment enhanced cell survival pathway activation through the PI3K, Akt and Bad phosphorylation. Compared with SHSST as well as silymarin and baicalein, SHSSTc provided a magnificent liver protection effect, especially in survival pathway activation/TUNEL-apoptotic cell reduction/serum cholesterol level suppression. All these data suggested that β-CD complex modified the SHSST and promoted the bioavailability and liver protection effects. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 663-670, 2016.

  20. Reduced SHARPIN and LUBAC Formation May Contribute to CCl4- or Acetaminophen-Induced Liver Cirrhosis in Mice

    Directory of Open Access Journals (Sweden)

    Takeshi Yamamotoya

    2017-02-01

    Full Text Available Linear ubiquitin chain assembly complex (LUBAC, composed of SHARPIN (SHANK-associated RH domain-interacting protein, HOIL-1L (longer isoform of heme-oxidized iron-regulatory protein 2 ubiquitin ligase-1, and HOIP (HOIL-1L interacting protein, forms linear ubiquitin on nuclear factor-κB (NF-κB essential modulator (NEMO and induces NF-κB pathway activation. SHARPIN expression and LUBAC formation were significantly reduced in the livers of mice 24 h after the injection of either carbon tetrachloride (CCl4 or acetaminophen (APAP, both of which produced the fulminant hepatitis phenotype. To elucidate its pathological significance, hepatic SHARPIN expression was suppressed in mice by injecting shRNA adenovirus via the tail vein. Seven days after this transduction, without additional inflammatory stimuli, substantial inflammation and fibrosis with enhanced hepatocyte apoptosis occurred in the livers. A similar but more severe phenotype was observed with suppression of HOIP, which is responsible for the E3 ligase activity of LUBAC. Furthermore, in good agreement with these in vivo results, transduction of Hepa1-6 hepatoma cells with SHARPIN, HOIL-1L, or HOIP shRNA adenovirus induced apoptosis of these cells in response to tumor necrosis factor-α (TNFα stimulation. Thus, LUBAC is essential for the survival of hepatocytes, and it is likely that reduction of LUBAC is a factor promoting hepatocyte death in addition to the direct effect of drug toxicity.

  1. Recovery of the Cell Cycle Inhibition in CCl4-Induced Cirrhosis by the Adenosine Derivative IFC-305

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    Victoria Chagoya de Sánchez

    2012-01-01

    Full Text Available Introduction. Cirrhosis is a chronic degenerative illness characterized by changes in normal liver architecture, failure of hepatic function, and impairment of proliferative activity. The aim of this study is to know how IFC-305 compound induces proliferation of the liver during reversion of cirrhosis. Methods. Once cirrhosis has been installed by CCl4 treatment for 10 weeks in male Wistar rats, they were divided into four groups: two received saline and two received the compound; all were euthanized at 5 and 10 weeks of treatment. Liver homogenate, mitochondria, and nucleus were used to measure cyclins, CDKs, and cell cycle regulatory proteins PCNA, pRb, p53, E2F, p21, p27, HGF, liver ATP, and mitochondrial function. Results. Diminution and small changes were observed in the studied proteins in the cirrhotic animals without treatment. The IFC-305-treated rats showed a clear increase in most of the proteins studied mainly in PCNA and CDK6, and a marked increased in ATP and mitochondrial function. Discussion/Conclusion. IFC-305 induces a recovery of the cell cycle inhibition promoting recovery of DNA damage through the action of PCNA and p53. The increase in energy and preservation of mitochondrial function contribute to recovering the proliferative function.

  2. Effectiveness of xenotransplantation of human fetal hepatocytes in spleen of rats with acute liver failure induced by CCL4

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    Abdukhakim Khadjibaev

    2013-04-01

    Full Text Available Human’s fetal hepatocytes (HFH were intrasplenic transplanted white non-pedigree rats with acute liver failure (ALF challenged by single per oral administration of hepatotropic toxin diluted in oil ССl4 at a dose 10 ml/kg (volumetric correlation 1:1 (10 mL/kg body weight as a 1:1 mixture of CCl4 and mineral oil. Transplantation had positive effect on all biochemical blood parameters of the studying animals. Morphologic study showed that reparative-restorative processes were arising in hepatic parenchyma after administration of HFH into splenic pulp of rats with model of ALF on days 14-21. Substantial and main factor in restoration of parenchyma was restoration of micro topographic interrelations in acinus as well as polyploidy of hepatic cells expressed in increase of hepatocytes’ nuclei sizes and hypertrophy of cells themselves. It is an indirect confirmation of engraftment of HFH in liver of rats with model of ALF.

  3. Polymerization of MIP-1 chemokine (CCL3 and CCL4) and clearance of MIP-1 by insulin-degrading enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Min; Guo, Qing; Guo, Liang; Lenz, Martin; Qian, Feng; Koenen, Rory R.; Xu, Hua; Schilling, Alexander B.; Weber, Christian; Ye, Richard D.; Dinner, Aaron R.; Tang, Wei-Jen (IIT); (Aachen); (UC); (UIC)

    2010-12-07

    Macrophage inflammatory protein-1 (MIP-1), MIP-1{alpha} (CCL3) and MIP-1{beta} (CCL4) are chemokines crucial for immune responses towards infection and inflammation. Both MIP-1{alpha} and MIP-1{beta} form high-molecular-weight aggregates. Our crystal structures reveal that MIP-1 aggregation is a polymerization process and human MIP-1{alpha} and MIP-1{beta} form rod-shaped, double-helical polymers. Biophysical analyses and mathematical modelling show that MIP-1 reversibly forms a polydisperse distribution of rod-shaped polymers in solution. Polymerization buries receptor-binding sites of MIP-1{alpha}, thus depolymerization mutations enhance MIP-1{alpha} to arrest monocytes onto activated human endothelium. However, same depolymerization mutations render MIP-1{alpha} ineffective in mouse peritoneal cell recruitment. Mathematical modelling reveals that, for a long-range chemotaxis of MIP-1, polymerization could protect MIP-1 from proteases that selectively degrade monomeric MIP-1. Insulin-degrading enzyme (IDE) is identified as such a protease and decreased expression of IDE leads to elevated MIP-1 levels in microglial cells. Our structural and proteomic studies offer a molecular basis for selective degradation of MIP-1. The regulated MIP-1 polymerization and selective inactivation of MIP-1 monomers by IDE could aid in controlling the MIP-1 chemotactic gradient for immune surveillance.

  4. Hepatoprotective effect ofSolanum xanthocarpum fruit extract against CCl4 induced acute liver toxicity in experimental animals

    Institute of Scientific and Technical Information of China (English)

    Ramesh K Gupta; Talib Hussain; G Panigrahi; Avik Das; Gireesh Narayan Singh; K Sweety; Md Faiyazuddin; Chandana Venkateswara Rao

    2011-01-01

    Objective:To investigate the hepatoprotective potential ofSolanum xanthocarpum (Solanaceae) (S. xanthocarpum) in experimental rats to validate its traditional claim.Methods: 50%ethanolic fruit extract ofS. xanthocarpum (SXE, 100, 200or400 mg/kg body weight) was administered daily for14days in experimental animals. Liver injury was induced chemically, byCCl4administration (1 mL/kg i.p.).The hepatoprotective activity was assessed using various biochemical parameters like aspartate aminotransferase (AST), alanine aminotransferase(ALT), Serum alkaline phosphatise (SALP) and total bilirubin. Meanwhile, in vivo antioxidant activities as lipid peroxidation (LPO), reduced glutathione(GSH), superoxide dismutase(SOD) and catalase(CAT) were screened along with histopathological studies.Results: Obtained results demonstrated that the treatment with SXE significantly (P<0.05- <0.001) and dose-dependently prevented chemically induced increase in serum levels of hepatic enzymes. Furthermore,SXE significantly (up toP<0.001) reduced the lipid peroxidation in the liver tissue and restored activities of defence antioxidant enzymes GSH, SOD and catalase towards normal levels. Histopathology of the liver tissue showed thatSXE attenuated the hepatocellular necrosis and led to reduction of inflammatory cells inflltration. Conclusions: The results of this study strongly indicate the protective effect ofSXE against acute liver injury which may be attributed to its hepatoprotective activity, and there by scientifically support its traditional use.

  5. Alteration in membrane protein, antioxidant status and hexokinase activity in erythrocytes of CCl4- induced cirrhotic rats.

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    Amir Hossein Doustimotlagh

    2014-11-01

    Full Text Available Several studies have shown that hepatocyte membrane composition changes in patients with cholestasis and cirrhosis. These alterations that are because of intracellular oxidative stress are supposed to be reflected in erythrocyte membrane. The aim of this study was to investigate the modification of erythrocyte membrane along with hexokinase and antioxidant enzymes during development of cirrhosis. Cirrhosis was induced by intraperitoneal injection of CCl4 in male Wistar rats. The test groups were: baseline, cholestatic, early cirrhotic and advanced cirrhotic along with an equal number of sham-control animals. The erythrocyte membrane modifications (protein sulfhydryl, protein carbonyl, and lipid peroxidation, as well as NO metabolites, were assessed. Activities of GPX, CAT, SOD and HK were also measured. Protein sulfhydryl content of the erythrocyte membrane (after 2, 6 and 10 weeks of injection had significant progressive decrease. In contrast, protein carbonyls were remarkably increased 2 weeks after injection but significantly decreased after 6 weeks and returned to normal levels after 10 weeks. No significant difference in erythrocyte HK activity or MDA content was observed. Test groups showed significantly lower erythrocyte GPx activity after six weeks and CAT and SOD activities along with NO metabolites content after two weeks (P<0.05. This study indicates that the progression of cirrhosis is accompanied by alterations in antioxidant enzyme and decreased NO metabolites. Protein carbonyl alteration occurs in the early stages of cirrhosis while protein sulfhydryl alterations have a progressive decrease in advanced cirrhosis.

  6. Inhibitory effects of four flavonoids on CCl4 induced liver fibrosis in mice%4种黄酮类化合物对CCl4致小鼠肝纤维化的防治作用

    Institute of Scientific and Technical Information of China (English)

    张硕; 洪波; 王庆林; 牛爱丽; 陈玉霜

    2012-01-01

    OBJECTIVE To study the effect of four flavonoids(apigenin,phloridzin,oligomeric proanthocyanidins and neohesperidin dihydrochaleone) on anti -hepatic fibrosis in mice. METHODS The experimental model mice of hepatic fibrosis was induced by CC14 105 male Kunming mice were randomly divided into 7 groups: normal control group, model group, colchicines group, apigenin group,phloridzin group,oligomeric proanthocyanidins group and neohesperidin dihydrochaleone group. All of them were sacrificed after five weeks of administration. The serum levels of ALT, AST,TP, ALB,HYP and liver index were determined. Liver tissue was handled with HE and Masson staining for hispathological study. RESULTS The four flavonoids significantly reduced the serum levels of ALT, AST,HYP and liver index. Histopathological observations showed that the four flavonoids could ameliorate the liver fibrosis in different degree. CONCLUSION The study showed that apigenin,phloridzin,oligomeric proanthocyanidins and neohesperidin dihydrochaleone had effect on preventing hepatic fibrosis.%目的 探讨芹菜素、根皮苷、原花青素和新橙皮苷二氢查尔酮等黄酮类化合物在CC14诱导的小鼠肝纤维化模型中的抗肝纤维化作用.方法 将♂昆明种小鼠105只随机均分为正常对照组、CCl4模型组、秋水仙碱组、芹菜素组、根皮苷组、原花青素组、新橙皮苷二氢查尔酮组.给药5周后采血并处死小鼠,测定并比较各组小鼠血清中丙氨酸氨基转移酶(ALT)、天门冬氨酸氨基转移酶(AST)的活性,总蛋白(TP)、白蛋白(ALB)及肝组织中的羟辅氨酸(HYP)的含量,计算小鼠的肝指数,观察肝脏的病理变化.结果 4种黄酮类化合物均可使模型小鼠血清中ALT、AST的含量、肝组织中羟脯氨酸的含量降低;病检也证明各组小鼠的肝细胞变性、坏死和肝纤维化均有不同程度的减轻.结论 芹菜素、根皮苷、原花青素及新橙皮苷二氢查尔酮有抗CCl4致小鼠肝纤维化的作用.

  7. Effect of Nrf2 signal pathway on acute hepatotoxicity induced by CCl4 in rat%Nrf2抗氧化通路在CCl4所致大鼠急性肝损伤中的保护作用

    Institute of Scientific and Technical Information of China (English)

    周清平; 蒋孝华; 符小波

    2016-01-01

    目的 研究Nrf2氧化损伤通路在CCl4所致大鼠急性肝损伤中的保护作用.方法 将20只雄性Wistar大鼠随机分为溶剂对照组和CCl4组,每组10只,另选10只雄性Wistar大鼠,通过载体进行转基因大鼠雄原核显微注射,获得了目的基因Nrf2-tk整合与特异表达的转基因大鼠,作为CCl4+Nrf2整合组.溶剂对照组静脉给予1%聚山梨酯-80,共4 d,CCl4组和Nrf2-tk整合组静脉给予1%聚山梨酯-80,共4 d,第4天给予1%聚山梨酯-8030 min后,静脉给予7.5 mg/kg CCl4,24 h后处死大鼠.测定血清中AST、ALT和LDH的水平,分别测定肝脏组织中MDA、GSH、GSSG的含量,并计算GSH/GSSG比值.留取肝脏组织,常规石蜡包埋切片,HE染色,光学显微镜下观察肝脏组织的病理变化.结果 和溶剂对照组相比,CCl4组大鼠的血清AST,ALT和LDH的水平明显升高(P0.05).肝脏的MDA含量以及GSH/GSSG比值显示Nrf2-tk整合组可以有效降低CCl4造成的脂质过氧化损伤和谷胱甘肽的消耗,肝脏病理观察结果显示和CCl4组相比,Nrf2-tk整合组明显减轻了CCl4造成的损伤.结论 Nrf2抗氧化损伤通路在CCl4所致大鼠急性肝损伤中的起着重要的保护作用.%Objective To determine the effect of Nuclear factor-erythroid 2-related factor 2 ( Nrf2 ) on acute hephrotoxicity induced by CCl4 in male rat.Methods 20 male Wistar rats were randomly divided into control group and CCl4 group, 10 rats in each group, another 10 male Wistar rats were transgenic rats microinjection through the carrier, obtained the Nrf2-tk gene integration and specific transgenic rats, as the CCl4 +Nrf2 integration group.The groups was given 1%polysorbate 80 for 4 days,Then the CCl4 and CCl4 +Nrf2 integration group were intraperitoneally injected with a single dose of CCl47.5 mg· kg-1 and were killed 24 h after CCl4 injection.The serum chemical parameters including asparate aminotransferase ( AST) ,alanine aminotransferase ( ALT) and lactate dehydrogenase ( LDH) were

  8. 18α、18β-甘草酸及其不同配比物对CCl4肝损伤大鼠的影响%Influence of 18α-,18β-Glycyrrhizic Acids and their Different Proportions on CCl4 Hepatotoxicity in Rats

    Institute of Scientific and Technical Information of China (English)

    茹仁萍; 尤琳雅; 陈晓瑾

    2011-01-01

    Objective: To study the protective function and select the optimal formulation of 18α-, 18β -glycyrrhizic acid and their different proportions against CCl4induced hepatotoxicity in rats. Methods:Healthy SD male rats, weighting (200 ± 20) g, 10 per group were randomized into 7 groups: control group, CCl4 - injured group, 18α - glycyrrhizic acid group, 18β - glycyrrhizic acid group and their proportions of 4∶ 6, 3∶ 7, 2∶ 8 groups. 6% CCl4 was given to rats by intraperitoneal (ip) injection, with the exception of control group. The rats were killed 24 h and 48h after CCl4 injury respectively. Serum alanine amiotransferase (ALT) ,aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) activities were determined; the liver and spleen weights of each rat as well as superoxide dismutase (SOD) activity in the liver homogenate were also detected. The liver pathological examination was also judged. Results :The acute CCl4 - injured model was successfully established due to increased serum enzyme level, swollen liver, atrophied spleen, decreased SOD activity and change in liver pathological examination Among the five formulations, the 3∶7 group did best in inhibiting the increases of serum ALT, AST and liver index, preventing the decreases of spleen index and SOD activity, and alleviating the lesion in liver cell obviously. Conclusion: In all, the formulation of 3∶ 7 showed the most potent liver protection against CCl4 - induced hepatotoxicity.%目的:研究不同配比的18α、18β-甘草酸(GL)对四氯化碳(CCl4)肝损伤大鼠的保护作用,探讨临床应用合理比例.方法取健康雄性SD大鼠(200±20)g 70只,随机分为7组,即正常组、CCl4肝损伤组、18α-GL、18β-GL和3个不同配比组(α:β比例分别为4:6、3:7和2:8).采用腹腔注射CCl4复制大鼠急性肝损伤模型.分别于24h和48h后摘眼球取血,测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)、乳酸脱氢酶(LDH)活性,同时测定肝脾重量,

  9. s-wave threshold in electron attachment - Observations and cross sections in CCl4 and SF6 at ultralow electron energies

    Science.gov (United States)

    Chutjian, A.; Alajajian, S. H.

    1985-01-01

    The threshold photoionization method was used to study low-energy electron attachment phenomena in and cross sections of CCl4 and SF6 compounds, which have applications in the design of gaseous dielectrics and diffuse discharge opening switches. Measurements were made at electron energies from below threshold to 140 meV at resolutions of 6 and 8 meV. A narrow resolution-limited structure was observed in electron attachment to CCl4 and SF6 at electron energies below 10 meV, which is attributed to the divergence of the attachment cross section in the limit epsilon, l approaches zero. The results are compared with experimental collisional-ionization results, electron-swarm unfolded cross sections, and earlier threshold photoionization data.

  10. Oxymatrine attenuates CCl4-induced hepatic fibrosis via modulation of TLR4-dependent inflammatory and TGF-β1 signaling pathways.

    Science.gov (United States)

    Zhao, Hong-Wei; Zhang, Zhen-Fang; Chai, Xuan; Li, Guang-Quan; Cui, He-Rong; Wang, Hong-Bo; Meng, Ya-Kun; Liu, Hui-Min; Wang, Jia-Bo; Li, Rui-Sheng; Bai, Zhao-Fang; Xiao, Xiao-He

    2016-07-01

    Oxymatrine (OMT) is able to effectively protect against hepatic fibrosis because of its anti-inflammatory property, while the underlying mechanism remains incompletely understood. In this study, forty rats were randomly divided into five groups: control group, model group (carbon tetrachloride, CCl4) and three OMT treatment groups (30, 60, 120mg/kg). After CCl4 alone, the fibrosis score was 20.2±0.8, and the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline content, and collagen I expression was elevated, but OMT blunted these parameters. Treatment with OMT prevented CCl4-induced increases in expression of pro-inflammatory and pro-fibrotic cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-α, meanwhile OMT promoted the expression of anti-inflammatory and anti-fibrotic factors such as interleukin (IL)-10 and bone morphogenetic protein and activin membrane-bound inhibitor (Bambi). Moreover, lipopolysaccharides (LPS) and high mobility group box-1 (HMGB1), which activates Toll-like receptor 4 (TLR4) and modulate hepatic fibrogenesis through hepatic stellate cells (HSCs) or Kupffer cells, were significantly decreased by OMT treatment. These results were further supported by in vitro data. First, OMT suppressed the expression of TLR4 and its downstream pro-inflammatory cytokines, lowered the level of HMGB1, TGF-β1 in macrophages. Then, OMT promoted Bambi expression and thereby inhibited activation of HSCs mediated by transforming growth factor (TGF)-β1. In conclusion, this study showed that OMT could effectively attenuate the CCl4-induced hepatic fibrosis, and this effect may be due to modulation of TLR4-dependent inflammatory and TGF-β1 signaling pathways.

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

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    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.

  12. Efficacy of a traditional unani formulation Jawarish-e-Amla Sada against CCl 4 induced liver toxicity in Albino Wistar rats: Comparison with silymarin treatment

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    Sunita Shailajan

    2015-01-01

    Full Text Available Background: Jawarish-e-Amla Sada (JAS; a polyherbal Unani formulation, is claimed as a potential hepatoprotective agent in traditional Unani medicine treatise. Aims and Objectives: Though, JAS has its composition recorded in ancient Unani texts, there have been minimal attempts to scientifically validate its hepatoprotective potential. The present work is an attempt to evaluate the hepatoprotective activity of JAS in vivo. Materials and Methods: CCl 4 intoxicated Albino Wistar rats were used to evaluate the hepatoprotective activity of JAS (0.7 g/kg and 1.0 g/kg, p.o. and the results were compared with, silymarin. The efficacy was established on the basis of altered levels of biochemical markers and histopathological analysis of the liver tissue. Results and Discussion: Treatment with the aqueous slurry of JAS significantly reduced the level of biochemical markers in CCl 4 intoxicated rats. These findings were well-supported by the histopathological analysis of liver tissue. The effect shown by JAS was found to be at par with silymarin treatment. Conclusion: This study suggests that CCl 4 induced liver damage can be ameliorated by traditional Unani formulation JAS. This justifies the traditional claim of JAS being a hepatoprotective agent.

  13. Protective Effect of Aframomum melegueta phenolics Against CCl4-Induced Rat Hepatocytes Damage; Role of Apoptosis and Pro-inflammatory Cytokines inhibition

    Science.gov (United States)

    El-Halawany, Ali M.; Dine, Riham Salah El; El Sayed, Nesrine S.; Hattori, Masao

    2014-01-01

    Aframomum melegueta is a commonly used African spice. Through a hepatoprotective bioassay-guided isolation, the chloroform fraction of A.melegueta seeds yielded one new diarylheptanoid named 3-(S)-acetyl-1-(4′-hydroxy-3′, 5′-di methoxyphenyl)-7-(3″,4″, 5″-trihydroxyphenyl)heptane (1), and two new hydroxyphenylalkanones, [8]-dehydrogingerdione (2) and [6]-dehydroparadol (3), in addition to six known compounds (4–9). The hepatoprotective effect of A. melegueta methanol extract, sub-fractions and isolated compounds was investigated using carbon tetrachloride (CCl4)-induced liver injury in a rat hepatocytes model. The methanol, chloroform extracts and compounds 1, 5, 8 and 9 of A. melegueta significantly inhibited the elevated serum alanine aminotransferase (ALT), thiobarbituric acid reactive substances (TBARS), tumor necrosis factor (TNFα), interleukin-1beta (Il-1β), caspase3 and 9 and enhanced the reduced liver glutathione (GSH) level caused by CCl4 intoxication. These results indicate that A.melegueta extracts, and isolated compounds play a protective role in CCl4 induced acute liver injury which might be due to elevated antioxidative defense potentials, suppressed inflammatory responses and apoptosis of liver tissue. PMID:25077538

  14. Effect of parsley (Petroselinum crispum (Mill.) Nym. ex A.W. Hill, Apiaceae) extracts on some biochemical parameters of oxidative stress in mice treated with CCl(4).

    Science.gov (United States)

    Popović, Mira; Kaurinović, Biljana; Jakovljević, Vida; Mimica-Dukic, Neda; Bursać, Marija

    2007-08-01

    The in vitro and in vivo antioxidant activity of different extracts of leaves and root of parsley (Petroselinum crispum (Mill.) Nym. ex A.W. Hill, Apiaceae) were studied. Free radical scavenging capacity (RSC) was evaluated measuring the scavenging activity on the 2,2-diphenyl-1-picrylhydrazil (DPPH) and OH radicals. Also, the effects on lipid peroxidation (LP) were evaluated. The results obtained showed that all examined extracts act as good scavengers of DPPH and OH radicals and reduce the intensity of LP. The in vivo effects were evaluated on some antioxidant systems (activities of LPx, GSH-Px, Px, CAT and XOD, and GSH content) in the mice liver and blood after treatment with the examined parsley extracts, or in combination with carbon tetrachloride (CCl(4)). On the basis of the results obtained it can be concluded that the examined extracts exhibited a certain protective effect. However, combined treatments with CCl(4) and the examined extracts showed both positive and negative synergism, inducing or suppressing the influence of CCl(4) alone.

  15. Highly potent HIV inhibition: engineering a key anti-HIV structure from PSC-RANTES into MIP-1 beta/CCL4.

    Science.gov (United States)

    Gaertner, Hubert; Lebeau, Olivier; Borlat, Irène; Cerini, Fabrice; Dufour, Brigitte; Kuenzi, Gabriel; Melotti, Astrid; Fish, Richard J; Offord, Robin; Springael, Jean-Yves; Parmentier, Marc; Hartley, Oliver

    2008-02-01

    The HIV coreceptor CCR5 is a validated target for both the prevention and therapy of HIV infection. PSC-RANTES, an N-terminally modified analogue of one of the natural chemokine ligands of CCR5 (RANTES/CCL5), is a potent inhibitor of HIV entry into target cells. Here, we set out to engineer the anti-HIV activity of PSC-RANTES into another natural CCR5 ligand (MIP-1beta/CCL4), by grafting into it the key N-terminal pharmacophore region from PSC-RANTES. We were able to identify MIP-1beta/CCL4 analogues that retain the receptor binding profile of MIP-1beta/CCL4, but acquire the very high anti-HIV potency and characteristic inhibitory mechanism of PSC-RANTES. Unexpectedly, we discovered that in addition to N-terminal structures from PSC-RANTES, the side chain of Lys33 is also necessary for full anti-HIV potency.

  16. «Evaluation of the anti-icterus effect of crude powdered leaf of Argemone mexicana L. (Papaveraceae against CCl4-induced liver injury in rats».

    Directory of Open Access Journals (Sweden)

    T.S. SOURABIE

    2012-10-01

    Full Text Available Leaves of Argemone mexicana L. (Papaveraceae are used in the folk medicine of Burkina Faso (West Africa to treat a variety of illness. Aqueous decoction of the drug is indicated in the treatment of malaria fever, abdominal pains, and jaundice. A preliminary study led by the authors showed a good anti-icterus (hepatoprotective activity of leaves extracts on intoxicated Wistar rats. The aim of the present investigation was to evaluate the anti-icterus activity of crude leaf powder against CCl4 induced hepatotoxicity in rats. Liver functions were assessed by the activities of liver marker enzymes, ASAT/GOT, ALAT/GPT, ALP, Total Bilirubin (TBIL and Direct Bilirubin (DBIL.A crude powdered leaf suspended in acacia gum solution (2% p/w was administered orally to the animal at doses of 125, 250 and 500 mg/kg attenuated significantly (p<0,05 the elevation of serum enzymes level and bilirubin (total and direct if compared to the CCl4 treated groups. Silymarin (100 mg/kg, p.o., a known antihepatoprotective drug was used as reference. The results showed a dose-dependent anti-hepatotoxic effect against liver injury induced by CCl4 in rats. These findings give an opportunity for a future elaboration of galenic formulation as phytomedicament.

  17. Snailase Preparation of Ginsenoside M1 from Protopanaxadiol-Type Ginsenoside and Their Protective Effects Against CCl4-Induced Chronic Hepatotoxicity in Mice

    Directory of Open Access Journals (Sweden)

    Li Chen

    2011-12-01

    Full Text Available To investigate the protective effects of protopanaxadiol-type ginsenoside (PDG and its metabolite ginsenoside M1 (G-M1 on carbon tetrachloride (CCl4-induced chronic liver injury in ICR mice, we carried out conversion of protopanaxadiol-type ginsenosides to ginsenoside M1 using snailase. The optimum time for the conversion was 24 h at a constant pH of 4.5 and an optimum temperature of 50 °C. The transformation products were identified by high-performance liquid chromatography and electrospray ion-mass spectrometry. Subsequently, most of PDG was decomposed and converted into G-M1 by 24 h post-reaction. During the study on hepatoprotective in a mice model of chronic liver injury, PDG or G-M1 supplement significantly ameliorated the CCl4-induced liver lesions, lowered the serum levels of select hepatic enzyme markers (alanine aminotransferase, ALT, and aspartate aminotransferase, AST and malondialdehyde and increased the activity of superoxide dismutase in liver. Histopathology of the liver tissues showed that PDG and G-M1 attenuated the hepatocellular necrosis and led to reduction of inflammatory cell infiltration. Therefore, the results of this study show that PDG and G-M1 can be proposed to protect the liver against CCl4-induced oxidative injury in mice, and the hepatoprotective effect might be attributed to amelioration of oxidative stress.

  18. A study of the x-irradiated Cs sub 5 H sub 3 (SO sub 4) sub 4 centre dot H sub 2 O crystal by EPR in the 80-415 K temperature range

    CERN Document Server

    Waplak, S; Baranov, A I; Shuvalov, L A

    1997-01-01

    The EPR spectra of the x-irradiated fast proton conductor Cs sub 5 H sub 3 (SO sub 4) sub 4 centre dot H sub 2 O were investigated in the temperature range of 80-415 K. Two kinds of paramagnetic SO sub 4 sup - centres with different proton configurations below about 370 K and freeze-out behaviour of one of them below about 200 K were observed. The role of acid proton dynamics with respect to the glassy-like transition is discussed. (author)

  19. Aspects of the historical development of targetry for heavy ions of 0.05-2000 A centre dot MeV at GSI

    CERN Document Server

    Folger, H

    1999-01-01

    The progressively improved GSI accelerators provide beams of heavy ions from energies of 0.05-2000 A centre dot MeV at high particle intensities now. Therefore, a wide variety of common and new heavy-ion target techniques had to be installed and developed during the past 25 years to prepare and characterize self-supported or backed heavy-ion-targets of chemical elements and compounds from hydrogen (as polyethylene) to uranium. The thickness ranged from 2x10 sup - sup 6 to 20 g/cm sup 2 for beam spots of about 5 mm in diameter. Homogeneity, surface structure or individual shape had to be adapted to the needs of each experiment. Special setups were required for targets of poisonous materials, of highly enriched stable isotopes or those of radioactive species in minute amounts. The capability of thin-layer technologies was as well applied to prepare and measure stripper foils or various high-vacuum deposits for experimental or accelerator purposes. The development of different rotating target wheels and control ...

  20. NMR investigation on isotope effect of glycinium phosphite H sub 3 NCH sub 2 COOH centre dot H sub 2 PO sub 3

    CERN Document Server

    Ishibashi, T

    2003-01-01

    The motions of the phosphite anions and glycinium cations in H sub 3 NCH sub 2 COOH centre dot H sub 2 PO sub 3 (GPI) and its deuterated analogue (DGPI) were investigated by sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P spin-lattice relaxation times T sub 1. For both GPI and DGPI, T sub 1 's of the sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P nuclei reflect the amino rotation, methylene libration and motion of the phosphite anions, respectively. Activation energies obtained from T sub 1 's of sup 1 H, sup 1 sup 3 C and sup 3 sup 1 P nuclei are 28.6(2), 26.0(4) and 26.2(4) kJ/mol for GPI and are 34.9(6), 27(1), 47(2) kJ/mol for DGPI, respectively. The deuterium substitution increases E sub a for the motion influenced by the hydrogen bonding. In all the observed motions, correlation times of DGPI are larger than those of GPI. (author)

  1. In vivo antioxidant effect of aqueous root bark, stem bark and leaves extracts of Vitex doniana in CCl4 induced liver damage rats

    Institute of Scientific and Technical Information of China (English)

    Kadejo Olubukola Adetoro; James Dorcas Bolanle; Sallau Balarebe Abdullahi; Ozigi Abdulrahaman Ahmed

    2013-01-01

    Objective: The antioxidant effects of aqueous root bark, stem bark and leaves of Vitex doniana (V. doniana) were evaluated in carbon tetrachloride (CCl4) induced liver damage and non induced liver damage albino rats. Methods: A total of 60 albino rats (36 induced liver damage and 24 non induced liver damage) were assigned into liver damage and non liver damage groups of 6 rats in a group. The animals in the CCl4 induced liver damage groups, were induced by intraperitoneal injection with a single dose of CCl4 (148 mg·ml-1·kg-1 body weight) as a 1:1 (v/v) solution in olive oil and were fasted for 36 h before the subsequent treatment with aqueous root bark, stem bark and leaves extracts of V. doniana and vitamin E as standard drug (100 mg/kg body weighy per showed that the induction with CCl4, significantly (P0.05) difference between TBARS, SOD and CAT in the liver of the induced treated groups and normal control group. In the kidney, TBARS showed no significant (P>0.05) difference between the normal and the induced groups, SOD was significantly CAT compared with the normal control except in the kidney of animals treated with stem extract animals, there was no significant (P>0.05) change in the liver and kidney level of TBARS, SOD and not treated group. The studies also showed that when the extracts were administered to normal was significantly (P<0.05) increased in root and vitamin E groups when compared to induced (P<0.05) reduced in the CCl4 group compared to standard drug and normal control groups, CAT where TBARS was significantly (P<0.05) lowered compared to control group. Conclusion: The result of the present study suggests that application of V. doniana plant would play an important role in increasing the antioxidant effect and reducing the oxidative damage that formed both in liver and in kidney tissues. However stem bark has potential to improve renal function in normal rats.

  2. Antioxidative effects of pumpkin seed (Cucurbita pepo) protein isolate in CCl4-induced liver injury in low-protein fed rats.

    Science.gov (United States)

    Nkosi, C Z; Opoku, A R; Terblanche, S E

    2006-11-01

    The effects of pumpkin seed (Cucurbita pepo) protein isolate on the plasma activity levels of catalase (CA), superoxide dismutase (SOD), glutathione peroxidase (GSHpx) and total antioxidant capacity (TAC) as well as glucose-6-phosphatase (G6Pase) in liver homogenates and lipid peroxidation (LPO-malondialdehyde-MDA) levels in liver homogenates and liver microsomal fractions against carbon tetrachloride (CCl(4))-induced acute liver injury in low-protein fed Sprague-Dawley rats (Rattus norvegicus) were investigated. A group of male Sprague-Dawley rats maintained on a low-protein diet for 5 days were divided into three subgroups. Two subgroups were injected with carbon tetrachloride and the other group with an equivalent amount of olive oil. Two hours after CCl(4) intoxication one of the two subgroups was administered with pumpkin seed protein isolate and thereafter switched onto a 20% pumpkin seed protein isolate diet. The other two groups of rats were maintained on the low-protein diet for the duration of the investigation. Groups of rats from the different subgroups were killed at 24, 48 and 72 h after their respective treatments. After 5 days on the low-protein diet the activity levels of all the enzymes as well as antioxidant levels were significantly lower than their counterparts on a normal balanced diet. However, a low-protein diet resulted in significantly increased levels of lipid peroxidation. The CCl(4) intoxicated rats responded in a similar way, regarding all the variables investigated, to their counterparts on a low-protein diet. The administration of pumpkin seed protein isolate after CCl(4) intoxication resulted in significantly increased levels of all the variables investigated, with the exception of the lipid peroxidation levels which were significantly decreased. From the results of the present study it is concluded that pumpkin seed protein isolate administration was effective in alleviating the detrimental effects associated with protein

  3. Systemic levels of CCL2, CCL3, CCL4 and CXCL8 differ according to age, time period and season among children newly diagnosed with type 1 diabetes and their healthy siblings

    DEFF Research Database (Denmark)

    Thorsen, S U; Eising, S; Mortensen, H B;

    2014-01-01

    -based registry of children diagnosed with T1D from 1997 to 2005, we studied five different inflammatory chemokines (CCL2, CCL3, CCL4, CCL5 and CXCL8). Four hundred and eighty-two cases and 479 sibling frequencies matched on age and sample year distribution were included. Patients showed lower levels of CCL4...... compared to siblings, but this result was not significant after correction for multiple testing. CCL2, CCL3, CCL4 and CXCL8 levels were highest in the most recent cohorts (P siblings. A significant seasonal variation - for most of the chemokines - was demonstrated...... with the highest level during the summer period in both patients and siblings. In addition, there was a significant inverse relationship between CCL4 levels and age. When comparing patients and siblings, remarkably few differences were identified, but interestingly chemokine levels varied with age, season...

  4. Hepatoprotective and antioxidant activity of methanolic extract of flowers ofNerium oleander against CCl4-induced liver injury in rats

    Institute of Scientific and Technical Information of China (English)

    Kumar Gaurav Singhal; Ghanshyam Das Gupta

    2012-01-01

    Objective:To investigate the antioxidant and hepatoprotective activity of methanolic flower extract ofNerium oleander againstCCl4-induced hepatotoxicity in rats.Methods:In vitro antioxidant activity of methanolic extract of flowers of Nerium oleander(MENO-F) was evaluated by various assays, including reducing power, lipid peroxidation,DPPH,ABTS, superoxide anion, hydroxyl radicals and metal chelation.The hepatoprotective andin vivo antioxidant activity ofMENO-F were evaluated againstCCl4-induced hepatic damage in rats.TheMENO-F at dose of100,200 and400 mg/kg were administered orally once daily for seven days.Serum enzymatic levels of serum glutamate oxaloacetate transaminase(AST), serum glutamate pyruvate transaminase(ALT), serum alkaline phosphatase(ALP) and total bilirubin were estimated along with estimation of superoxide dismutase(SOD) and malondialdehyde(MDA) levels in liver tissues.Further histopathological examination of the liver sections was carried out to support the induction of hepatotoxicity and hepatoprotective efficacy.Results:The extract showed potent activities on reducing power, lipid peroxide,DPPH,ABTS, superoxide anion, hydroxyl radical and metal chelation.The substantially elevated serum enzymatic levels ofAST,ALT,ALP and total bilirubin were found to be restored towards normalization significantly by theMENO-F in a dose dependent manner with maximum hepatoprotection at400 mg/kg dose level.The histopathological observations supported the biochemical evidences of hepatoprotection.Elevated level ofSOD and decreased level ofMDA further strengthen the hepatoprotective observations.Conclusions:The results of the present study strongly reveal thatMENO-F has potent antioxidant activity and hepatoprotective activity againstCCl4-induced hepatic damage in experimental animals.

  5. Adipose derived mesenchymal stem cells transplantation via portal vein improves microcirculation and ameliorates liver fibrosis induced by CCl4 in rats

    Directory of Open Access Journals (Sweden)

    Wang Yu

    2012-06-01

    Full Text Available Abstract Introduction Adipose derived mesenchymal stem cells (ADMSCs, carrying the similar characteristics to bone marrow mesenchymal stem cells, only much more abundant and easier to obtain, may be a promising treatment for liver fibrosis. We aim to investigate the therapeutic potential of ADMSCs transplantation in liver fibrosis caused by carbon tetrachloride (CCl4 in rats as well as its underlying mechanism, and to further explore the appropriate infusion pathway. Methods ADMSCs were isolated, cultured and identified. Placebo and ADMSCs were transplanted via portal vein and tail vein respectively into carbon tetrachloride (CCl4-induced liver fibrosis rats. Computed tomography (CT perfusion scan and microvessel counts were performed to measure the alteration of liver microcirculation after therapy. Liver function tests and histological findings were estimated. Results CT perfusion scan shown significant decrease of hepatic arterial perfusion index, significant increased portal vein perfusion, total liver perfusion in rats receiving ADMSCs from portal vein, and Factor VIII (FVIII immunohistochemical staining shown significant decrease of microvessels in rats receiving ADMSCs from portal vein, indicating microcirculation improvement in portal vein group. Vascular endothelial growth Factor (VEGF was significantly up-regulated in fibrosis models, and decreased after ADMSCs intraportal transplantation. A significant improvement of liver functional test and histological findings in portal vein group were observed. No significance was found in rats receiving ADMSCs from tail vein. Conclusions ADMSCs have a therapeutic effect against CCl4-mediated liver fibrosis. ADMSCs may benefit the fibrotic liver through alteration of microcirculation, evidenced by CT perfusion scan and down-regulation of VEGF. Intraportal transplantation is a better pathway than tail vein transplantation.

  6. Evaluation of chemopreventive effect ofFumaria indica against N-nitrosodiethylamine and CCl4-induced hepatocellular carcinoma in Wistar rats

    Institute of Scientific and Technical Information of China (English)

    Talib Hussain; Hefazat H Siddiqui; Sheeba Fareed; M Vijayakumar; Chandana V Rao

    2012-01-01

    Objective:To investigation the chemopreventive potential ofFumaria indica (F. indica) extract (FIE) on N-nitrosodiethylamine and CCl4-induced hepatocarcinogenesis in Wistar rats.Methods:The experimental animals were divided into six groups (n=6). Hepatocellular carcinoma was induced by single intraperitoneal injection ofN-nitrosodiethylamine (NDEA) in normal saline at a dose of 200 mg/kg body weight followed by weekly subcutaneous injections of CCl4 (3 mL/kg/week) for 6 weeks, as the promoter of carcinogenic effect. After administration of the carcinogen, 200 and 400 mg/kg of FIE were administered orally once a day throughout the study. At the end of 20 weeks, the body weight, liver weight and relative liver weight were measured. The percentage of nodule incidence and liver cancer markers such as aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP),γ-glutamyl transferase (γ-GT), total bilirubin level (TBL), α-feto protein (AFP) and carcinoembryonic antigen were estimated along with histopathological investigation in experimental groups of rats. Results: Obtained results demonstrated that the cotreatment with FIE significantly prevented the decrease of the body weight and also increased in relative liver weight caused by NDEA. The treatment with FIE significantly reduced the nodule incidence and nodule multiplicity in the rats after NDEA administration. The levels of liver cancer markers such as AST, ALT, ALP,γ-glutamyl transferase, TBL, AFP and carcinoembryonic antigen were substantially increased by NDEA treatment. However, FIE treatment significantly reduced the liver injury and restored the entire liver cancer markers. Histological observations of liver tissues too correlated with the biochemical observations.Conclusions: These finding powerfully supports thatF. indica exert chemopreventive effect by suppressing the tumor burden and restoring the activities of hepatic cancer marker enzymes on NDEA and CCl4-induced

  7. Balance between oxidative damage and proliferative potential in an experimental rat model of CCl4-induced cirrhosis: protective role of adenosine administration.

    Science.gov (United States)

    Hernández-Muñoz, R; Díaz-Muñoz, M; López, V; López-Barrera, F; Yáñez, L; Vidrio, S; Aranda-Fraustro, A; Chagoya de Sánchez, V

    1997-11-01

    Oxidative stress and its consequent lipid peroxidation (LP) exert harmful effects, which have been currently involved in the generation of carbon tetrachloride-induced cirrhosis. However, the recent report that "physiological" LP can be associated with liver regeneration (LR) makes it necessary to discriminate between oxidative stress-induced and LR-associated LP. In rats rendered cirrhotic by continuous CCl4 administration for 4 weeks, moderate cell necrosis and fine fatty infiltration were found. The histological abnormalities were accompanied by increased LP, mainly accounted for by the microsomal and cytosolic fractions and evidence of oxidative stress (decreased hepatic glutathione content and changes in xanthine oxidase and pentose phosphate pathway activities). After 8 weeks, a micronodular cirrhosis developed, but oxidative stress was greatly attenuated, only persisting in the enhanced LP confined to microsomes. Simultaneous administration of adenosine, a reliable hepatoprotector that readily prevents the onset of liver fibrosis, was able to block the oxidative stress induced by the long-term CCl4 treatment but elicited a selective subcellular distribution of increased LP, similar to that found during LR. The adenosine-induced changes in liver LP (mainly in the nuclear fraction) correlated with an increased activity of thymidine kinase. Therefore, data suggest that adenosine-mediated preservation of energy availability and mitochondrial function could participate in preventing the onset of oxidative stress in cirrhotic rats. The latter could induce a successful liver recovery, curtailing the sequence of events leading to fibrogenesis.

  8. 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

  9. 慈菇对CCl4致大鼠肝纤维化血清cyfra21-1和CEA影响的探讨%The Effect of Sagittaria Agittifolia on Changes of Cyfra21-1 and CEA in Rats of CCl4 Experimental Liver Fibrosis

    Institute of Scientific and Technical Information of China (English)

    吴小南; 汪家梨; 盛健; 黄建宏

    2001-01-01

    目的探讨慈菇对CCl4致大鼠肝纤维化的干预作用.方法对5月龄Wistar大鼠,用CCl4染毒致大鼠形成肝组织纤维化,以ELISA法和放射免疫分析法检测大鼠血清cyfra21-1和CEA的浓度的变化,并观察慈菇的干预效果.结果染毒组大鼠cyfra21-1和CEA明显高于对照组,慈菇可减轻CCl4致大鼠肝纤维化程度并减少cyfra21-1和CEA的产生.结论大鼠肝纤维化后血清cyfra21-1和CEA升高,提示慈菇干预作用的机理值得深入探讨.

  10. Energies and wave functions of an off-centre donor in hemispherical quantum dot: Two-dimensional finite difference approach and ritz variational principle

    Energy Technology Data Exchange (ETDEWEB)

    Nakra Mohajer, Soukaina; El Harouny, El Hassan [Laboratoire de Physique de la Matière Condensée, Département de Physique, Faculté des Sciences, Université Abdelmalek Essaadi, B.P. 2121 M’Hannech II, 93030 Tétouan (Morocco); Ibral, Asmaa [Equipe d’Optique et Electronique du Solide, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida Principale, El Jadida (Morocco); Laboratoire d’Instrumentation, Mesure et Contrôle, Département de Physique, Faculté des Sciences, Université Chouaïb Doukkali, B. P. 20 El Jadida Principale, El Jadida (Morocco); El Khamkhami, Jamal [Laboratoire de Physique de la Matière Condensée, Département de Physique, Faculté des Sciences, Université Abdelmalek Essaadi, B.P. 2121 M’Hannech II, 93030 Tétouan (Morocco); and others

    2016-09-15

    Eigenvalues equation solutions of a hydrogen-like donor impurity, confined in a hemispherical quantum dot deposited on a wetting layer and capped by an insulating matrix, are determined in the framework of the effective mass approximation. Conduction band alignments at interfaces between quantum dot and surrounding materials are described by infinite height barriers. Ground and excited states energies and wave functions are determined analytically and via one-dimensional finite difference approach in case of an on-center donor. Donor impurity is then moved from center to pole of hemispherical quantum dot and eigenvalues equation is solved via Ritz variational principle, using a trial wave function where Coulomb attraction between electron and ionized donor is taken into account, and by two-dimensional finite difference approach. Numerical codes developed enable access to variations of donor total energy, binding energy, Coulomb correlation parameter, spatial extension and radial probability density with respect to hemisphere radius and impurity position inside the quantum dot.

  11. Biosynthesis of silver nanoparticles from Premna serratifolia L. leaf and its anticancer activity in CCl4-induced hepato-cancerous Swiss albino mice

    Science.gov (United States)

    Arockia John Paul, J.; Karunai Selvi, B.; Karmegam, N.

    2015-11-01

    In this study, we report the biosynthesis of silver nanoparticles using the ethanolic leaf powder extract of Premna serratifolia L. and its anticancer activity in carbon tetra chloride (CCl4)-induced liver cancer in Swiss albino mice (Balb/c). The synthesized silver nanoparticles were characterized by SEM, FTIR and XRD analyses. The Debye-Scherrer equation was used to calculate particle size and the average size of silver nanoparticles synthesized from P. serratifolia leaf extract was 22.97 nm. The typical pattern revealed that the sample contained cubic structure of silver nanoparticles. FTIR analysis confirmed that the bioreduction of silver ions to silver nanoparticles is due to reduction by capping material of the plant extract. The silver nanoparticles of P. serratifolia leaf extract were effective in treating liver cancer in Swiss albino mice when compared with P. serratifolia leaf extract with isoleucine.

  12. Accumulation of xenotransplanted canine bone marrow cells in NOD/SCID/γc(null) mice with acute hepatitis induced by CCl4.

    Science.gov (United States)

    Kato, Takashi; Hisasue, Masaharu; Segawa, Kazuhito; Fujimoto, Ayumi; Makiishi, Eri; Neo, Sakurako; Yasuno, Kyohei; Kobayashi, Ryosuke; Tsuchiya, Ryo

    2013-07-31

    Bone marrow cell infusion (BMI) has recently been suggested as an effective therapy for refractory liver disease; however, the efficiency of BMI using canine bone marrow cells (cBMCs) has not been reported. We evaluated the accumulation potential of cBMCs in a mouse model of acute liver failure. Acute hepatitis was induced by carbon tetrachloride (CCl4) treatment in NOD/SCID/γc(null)(NOG) mice and wild-type (WT) C57BL mice, and the characteristics of liver dysfunction and the degree of hepatic injury and regeneration were compared between the two mouse models. Next, female CCl4-treated NOG mice were xenotransplanted with male PKH26-labeled cBMCs, and the potential of cBMCs to accumulate in injured liver tissue compartments was examined. Fluorescence microscopy was performed to histologically detect the infused cBMCs, and DNA polymerase chain reaction was performed for detection of the male Y chromosome (SRY gene) in the recipient female NOG mice. The number of PKH26-positive cBMCs transplanted in the liver tissue gradually increased in the NOG mice. The infused cBMCs were located in the necrotic area of the liver at an early stage after transplantation, and most had accumulated a week after transplantation. However, the therapeutic efficacy of the xenotransplantation remained unclear, because no significant differences were observed concerning the extent liver injury and regeneration between the cBMC-transplanted and saline control mice. These results suggest that cBMCs will specifically accumulate in injured liver tissue and that BMC transplantation may have the potential to repair liver deficiency.

  13. Therapeutic efficacy of ethanolic extract of Aerva javanica aerial parts in the amelioration of CCl4-induced hepatotoxicity and oxidative damage in rats

    Directory of Open Access Journals (Sweden)

    Ahmed H. Arbab

    2016-04-01

    Full Text Available Background: Liver diseases, the fifth most common cause of global death, can be metabolic, toxin-induced, or infective. Though approximately 35 Saudi medicinal plants are traditionally used to treat liver disorders, the hepatoprotective potential of Aerva javanica has not been explored. Objective: To investigate the antioxidative and hepatoprotective effect of Aerva javanica. Design: Total ethanol extract of A. javanica aerial parts was prepared and tested on DCFH-toxicated HepG2 cells ex vivo, and in CCl4-injured Wistar rats in vivo. MTT assay was used to determine cell viability and the serum biochemical markers of liver injury as well as histopathology was performed. In vitro 1,1-diphenyl-2-picrylhydrazyl and β-carotene free-radical scavenging assay and phytochemical screening of the extract were done. Furthermore, A. javanica total extract was standardized and validated by high-performance thin layer chromatographic method. Results: MTT assay showed that, while DCFH-injured cells were recovered to ~56.7% by 100 µg/ml of the extract, a 200 µg/ml dose resulted in hepatocytes recovery by ~90.2%. Oral administration of the extract (100 and 200 mg/kg.bw/day significantly normalized the serum glutamate oxaloacetate transaminase, serum glutamate pyruvate transaminase, gamma-glutamyl transferase, alkaline phosphatase, bilirubin, cholesterol, high-density lipoprotein, low-density lipoprotein, very-low-density lipoprotein, triglyceride, and malondialdehyde levels, including tissue nonprotein sulfhydryl and total protein in CCl4-injured rats. In addition, the histopathology of dissected liver also revealed that A. javanica cured the tissue lesion compared to silymarin treatment. In vitro assays revealed strong free-radical scavenging ability of the extract and presence of alkaloids, flavonoids, tannins, sterols, and saponins where rutin, a well-known antioxidant flavonoid, was identified. Conclusions: Our findings demonstrate the potential of A

  14. Mutant MMP-9 and HGF gene transfer enhance resolution of CCl4-induced liver fibrosis in rats: role of ASH1 and EZH2 methyltransferases repression.

    Directory of Open Access Journals (Sweden)

    Hussein Atta

    Full Text Available Hepatocyte growth factor (HGF gene transfer inhibits liver fibrosis by regulating aberrant cellular functions, while mutant matrix metalloproteinase-9 (mMMP-9 enhances matrix degradation by neutralizing the elevated tissue inhibitor of metalloproteinase-1 (TIMP-1. It was shown that ASH1 and EZH2 methyltransferases are involved in development of liver fibrosis; however, their role in the resolution phase of liver fibrosis has not been investigated. This study evaluated the role of ASH1 and EZH2 in two mechanistically different therapeutic modalities, HGF and mMMP-9 gene transfer in CCl4 induced rat liver fibrosis. Liver fibrosis was induced in rats with twice a week intraperitoneal injection of CCl4 for 8 weeks. Adenovirus vectors encoding mMMP-9 or HGF genes were injected through tail vein at weeks six and seven and were sacrificed one week after the second injection. A healthy animal group was likewise injected with saline to serve as a negative control. Rats treated with mMMP-9 showed significantly lower fibrosis score, less Sirius red stained collagen area, reduced hydroxyproline and ALT concentration, decreased transforming growth factor beta 1 (TGF-β1 mRNA and lower labeling indices of α smooth muscle actin (α-SMA and proliferating cell nuclear antigen (PCNA stained cells compared with HGF- or saline-treated rats. Furthermore, TIMP-1 protein expression in mMMP-9 group was markedly reduced compared with all fibrotic groups. ASH1 and EZH2 protein expression was significantly elevated in fibrotic liver and significantly decreased in mMMP-9- and HGF-treated compared to saline-treated fibrotic livers with further reduction in the mMMP-9 group.Gene transfer of mMMP-9 and HGF reduced liver fibrosis in rats. ASH1 and EZH2 methyltransferases are significantly reduced in mMMP-9 and HGF treated rats which underlines the central role of these enzymes during fibrogenesis. Future studies should evaluate the role of selective pharmacologic inhibitors

  15. The Effects of Taoren-Honghua Herb Pair on Pathological Microvessel and Angiogenesis-Associated Signaling Pathway in Mice Model of CCl4-Induced Chronic Liver Disease

    Directory of Open Access Journals (Sweden)

    Shengyan Xi

    2016-01-01

    Full Text Available Chronic liver disease is one of the most common diseases that threaten human health. Effective treatment is still lacking in western medicine. Semen Persicae (Taoren and Flos Carthami (Honghua are known to relieve acute hepatic injury and inflammation, improve microcirculation, and reduce tissue fiber. The aim of our study is to investigate the potential mechanisms of Taoren-Honghua Herb Pair (THHP in murine model of chronic liver disease caused by Carbon Tetrachloride (CCl4. Mice were randomly divided into seven groups: (1 blank, (2 model, (3 control (colchicine, 0.1 mg/kg, (4 THHP (5.53, 2.67, and 1.33 g/kg, and (5 Tao Hong Siwu Decoction (THSWD (8.50 g/kg. Histological change and microvessels density were examined by microscopy. Hepatic function, serum fibrosis related factors, and hepatic vascular endothelial growth factor (VEGF were measured with ELISA. VEGF, kinase insert domain-containing receptor (KDR, Flt-1, and Akt mRNA expression in hepatic tissue were determined with PCR. Tissues of Akt, pAkt, KDR, and Flt-1 were measured with western blotting. Data from this study showed that THHP improved hepatic function and restrained the hepatic inflammation and fibrosis. Its role in inhibiting pathological angiogenesis and hepatic fibrogenesis may be through affecting the angiogenesis-associated VEGF and its upstream and downstream signaling pathways.

  16. The Effects of Taoren-Honghua Herb Pair on Pathological Microvessel and Angiogenesis-Associated Signaling Pathway in Mice Model of CCl4-Induced Chronic Liver Disease.

    Science.gov (United States)

    Xi, Shengyan; Yue, Lifeng; Shi, Mengmeng; Peng, Ying; Xu, Yangxinzi; Wang, Xinrong; Li, Qian; Kang, Zhijun; Li, Hanjing; Wang, Yanhui

    2016-01-01

    Chronic liver disease is one of the most common diseases that threaten human health. Effective treatment is still lacking in western medicine. Semen Persicae (Taoren) and Flos Carthami (Honghua) are known to relieve acute hepatic injury and inflammation, improve microcirculation, and reduce tissue fiber. The aim of our study is to investigate the potential mechanisms of Taoren-Honghua Herb Pair (THHP) in murine model of chronic liver disease caused by Carbon Tetrachloride (CCl4). Mice were randomly divided into seven groups: (1) blank, (2) model, (3) control (colchicine, 0.1 mg/kg), (4) THHP (5.53, 2.67, and 1.33 g/kg), and (5) Tao Hong Siwu Decoction (THSWD) (8.50 g/kg). Histological change and microvessels density were examined by microscopy. Hepatic function, serum fibrosis related factors, and hepatic vascular endothelial growth factor (VEGF) were measured with ELISA. VEGF, kinase insert domain-containing receptor (KDR), Flt-1, and Akt mRNA expression in hepatic tissue were determined with PCR. Tissues of Akt, pAkt, KDR, and Flt-1 were measured with western blotting. Data from this study showed that THHP improved hepatic function and restrained the hepatic inflammation and fibrosis. Its role in inhibiting pathological angiogenesis and hepatic fibrogenesis may be through affecting the angiogenesis-associated VEGF and its upstream and downstream signaling pathways.

  17. Altered thymocyte migration during experimental acute Trypanosoma cruzi infection: combined role of fibronectin and the chemokines CXCL12 and CCL4.

    Science.gov (United States)

    Mendes-da-Cruz, Daniella Arêas; Silva, João Santana; Cotta-de-Almeida, Vinícius; Savino, Wilson

    2006-06-01

    We previously showed migration disturbances in the thymus during experimental infection with Trypanosoma cruzi, the causative agent of Chagas disease. These changes were related to the enhanced expression of extracellular matrix ligands and receptors, leading to the escape of immature cells to the periphery. Here, we analyzed the expression and role of selected chemokines (CXCL12 and CCL4) and their receptors (CXCR4 and CCR5) in regulating thymocyte migration in conjunction with extracellular matrix during acute T. cruzi infection. We found increased chemokine deposition in the thymus of infected mice when compared to controls, accompanied by enhanced co-localization with fibronectin as well as up-regulated surface expression of CXCR4 and CCR5 in thymocytes. We also noticed altered thymocyte migration towards the chemokines analyzed. Such an enhancement was even more prominent when fibronectin was added as a haptotatic stimulus in combination with a given chemokine. Our findings suggest that thymocyte migration results from a combined action of chemokines and extracellular matrix (ECM), which can be altered during pathological conditions such as T. cruzi infection, and may be at the origin of the changes in the T cell repertoire seen in this pathological process.

  18. Improvement and optimization of CCl4 induced liver cirrhosis rats model accompanied with ascites%四氯化碳诱导大鼠肝硬化腹水模型的改进与优化

    Institute of Scientific and Technical Information of China (English)

    唐倩; 王卓; 赵雄; 吕茂贞; 吕茂民; 章金刚

    2012-01-01

    Objective To establish a stable, homogeneous, well-tolerated and efficient protocol to induce rat cirrhosis models accompanied with ascites using an improved carbon tetrachloride(CCl4) combined with phenobarbital sodium and alcohol method, thus establishing a basis for serum albumin effectiveness evaluation test. Methods Ninety male Wistar rats were randomly divided into five groups: blank control group containing 10 rats, CCl4 group, CC14 + phenobarbital sodium group, CCl4 + alcohol group and CC14 + phenobarbital sodium + alcohol group containing 20 rats respectively as model groups. The control group was given normal drinking water and injected with olive oil intraperitoneally. Rats in model groups were given different drinking water and an intraperitoneal injection of CC14 in a 2: 3 mixture with olive oil. The drugs given intraperitoneally were all at a dose of 2 ml/kg body mass, twice weekly for 12 weeks. We further measured the body mass and abdominal circumference, and tested the biochemical liver function indices as well as the colloid osmotic pressure ( COP) to evaluate the different processes in these groups. At the end of the induced operation the randomly selected rats in each group were sacrificed, and a section of right liver lobe was obtained and examined by histopathological method. The statistical analysis data were performed. Results Cirrhosis accompanied with ascites developed in all model groups between 8 and 12 weeks. However, at the end of the eighth week, rats in CCl4 + phenobarbital sodium + alcohol group were firstly detected to correspond with the model standards, CC14 + phenobarbital sodium group and CC14 + alcohol group were detected to have positive model signs at the ninth week. Only at the tenth week a few rats appeared to have ascites in CC14 group. All the model groups showed significant differences in the biochemical liver function indices, COP and body mass than the rats in control group, and the most significant differences were

  19. 鬼针聚炔苷对CCl4诱导的小鼠急性肝损伤的保护作用%Protective effect of bipinnatpolyacetylenicloside on acute liVer injury induced by CCl4 in mice

    Institute of Scientific and Technical Information of China (English)

    刘建军; 陈飞虎; 许慧; 王晓宇; 林梅英; 汤文建; 张群林

    2012-01-01

    Objective To study the protective effect of bipinnatpolyacetylenicloside on acute liver injury induced by CCl4in mice. Methods Mice were divided into 6 groups including control group, model group, positive group Silymarin, and bipinnatpolyacetylenicloside treatment(12.5,25,50 mg · kg-1 ) group. Acute hepatic injury was induced by injecting 0. 1ml( 10g)-1 0.2% olive oil solution of carbon tetrachloride and mice in bipinnatpolyacetylenicloside treatment group were intragastric administered with bipinnatpolyacetylenicloside for 6 days before given carbon tetrachloride. Serum AST and ALT were detemined. The contents of SOD, GSH-Px , MDA, and NO in liver homogenate were determined. The index as well as the histopathological test of liver was observed and the expression of NF-ΚB p65 in liver was tested by immunohistochemistry. Results Compared with those in model group, the levels of AST, ALT in serum, the contents of MDA, NO in liver homogenate were reduced significantly while the levels of SOD, GSH-Px in liver homogenate were markedly increased. In bipinnatpolyacetylenicloside treatment (12. 5,25,50 mg ·kg-1) groups, histopathological study showed that the degenerative and necrotic liver cells could be evidently ameliorated , and, immunohistochemistry research demonstrated that the expression of NF-ΚB was dramatically decreased. Conclusion The bipinnatpolyacetylenicloside has a protective effect on the carbon tetrachloride induced acute liver injury in mice, the mechanism of which may be related to its antioxidant characteristic as well as the production of NO and the expression of NF-ΚB being inhibited.%目的 研究鬼针聚炔苷(BPC)对CCl4诱导的小鼠急性肝损伤的保护作用.方法 腹腔注射0.2%CCl4橄榄油溶液建立小鼠急性肝损伤模型,以水飞蓟素为阳性对照,鬼针聚炔苷(12.5、25、50 mg·kg-1)灌胃给药6 d,测定各组小鼠血清中丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)的含量;检测肝组织

  20. Profile of circulating levels of IL-1Ra, CXCL10/IP-10, CCL4/MIP-1β and CCL2/MCP-1 in dengue fever and parvovirosis

    Directory of Open Access Journals (Sweden)

    Luzia Maria de-Oliveira-Pinto

    2012-02-01

    Full Text Available Dengue virus (DENV and parvovirus B19 (B19V infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL-1 receptor antagonist (Ra, CXCL10/inducible protein-10 (IP-10, CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1 were determined by multiplex immunoassay in serum samples obtained from B19V (37 and DENV-infected (36 patients and from healthy individuals (7. Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.

  1. Profile of circulating levels of IL-1Ra, CXCL10/IP-10, CCL4/MIP-1β and CCL2/MCP-1 in dengue fever and parvovirosis.

    Science.gov (United States)

    de-Oliveira-Pinto, Luzia Maria; Gandini, Mariana; Freitas, Laís Picinini; Siqueira, Marilda Mendonça; Marinho, Cíntia Ferreira; Setúbal, Sérgio; Kubelka, Claire Fernandes; Cruz, Oswaldo Gonçalves; Oliveira, Solange Artimos de

    2012-02-01

    Dengue virus (DENV) and parvovirus B19 (B19V) infections are acute exanthematic febrile illnesses that are not easily differentiated on clinical grounds and affect the paediatric population. Patients with these acute exanthematic diseases were studied. Fever was more frequent in DENV than in B19V-infected patients. Arthritis/arthralgias with DENV infection were shown to be significantly more frequent in adults than in children. The circulating levels of interleukin (IL)-1 receptor antagonist (Ra), CXCL10/inducible protein-10 (IP-10), CCL4/macrophage inflammatory protein-1 beta and CCL2/monocyte chemotactic protein-1 (MCP-1) were determined by multiplex immunoassay in serum samples obtained from B19V (37) and DENV-infected (36) patients and from healthy individuals (7). Forward stepwise logistic regression analysis revealed that circulating CXCL10/IP-10 tends to be associated with DENV infection and that IL-1Ra was significantly associated with DENV infection. Similar analysis showed that circulating CCL2/MCP-1 tends to be associated with B19V infection. In dengue fever, increased circulating IL-1Ra may exert antipyretic actions in an effort to counteract the already increased concentrations of IL-1β, while CXCL10/IP-10 was confirmed as a strong pro-inflammatory marker. Recruitment of monocytes/macrophages and upregulation of the humoral immune response by CCL2/MCP-1 by B19V may be involved in the persistence of the infection. Children with B19V or DENV infections had levels of these cytokines similar to those of adult patients.

  2. 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.

  3. PENGARUH PERLINDUNGAN EKSTRAK RIMPANG BANGLE (Zingiber cassumunar ROXB TERHADAP KERUSAKAN HATI TIKUS YANG DIINDUKSI CCI4 [Protective Effect of Bangle (Zingiber cassumunar ROXB Rhizome Extract on CCl4-Induced Liver Damage of Rats

    Directory of Open Access Journals (Sweden)

    Elmeizy Arafah1

    2004-12-01

    Full Text Available Zingiber cassumunar Roxb known as Bangle, has antioxidative and antiinflammatory activities. It has been used for medicinal purposes traditionally. The aim of this study was to investigate whether administration of Z. cassumunar extracts orally may prevent acute liver damage induced by carbontetrachloride (CCl4 in rats. The study was carried out on 5 groups of male Sprague-Dawley rats (n=5. Group 1 was given ethyl acetate fraction of Bangle rhizome extract (30 mg/kg bw (KS, group 2 was given dry juice of Bangle rhizome (30 mg/kg bw (SK, group 3 was given curcuminoid (30 mg/kg bw (KUR, group 4 as negative control (KN given 5% Tween 80 solution (10 ml/kg bw and Group 5 as control (K. Carbontetrachloride 0,1 ml/kg bw was given orally after 7 days to group KS, SK, KUR and KN. Rats were terminated 24 hours after CCl4-induction. Liver injury was evaluated by analyzed SGPT and SGOT activities from the serum and histopathologycal examination was conducted on the liver. The results clearly indicated that extracts of Z. cassumunar could reduced significantly the degree of liver damage induced by CCl4. It may be concluded that Z. cassumunar rhizome could be used as substance for hepatoprotector

  4. Magnetic susceptibility of Co sup 2 sup + pairs in [Co sub 2 (ox)tpmc](ClO sub 4) sub 2 centre dot 3H sub 2 O cluster complex

    CERN Document Server

    Spasojevic, V; Sovilj, S P; Mrozinski, J

    2000-01-01

    Calculation of the magnetic susceptibility of Co sup 2 sup + pairs in the recently synthesized cobaltous cluster complex [Co sub 2 (ox)tpmc](ClO sub 4) sub 2 centre dot 3H sub 2 O has been conducted by the use of two different theoretical models. The calculated results were compared to the experimental data collected in a wide temperature region. Conclusions on both the magnetic properties of Co sup 2 sup + dimers and the validity of the proposed models have been drawn. In the temperature region above chi(T) maximum, the best results are obtained with the Heisenberg model that includes spin-orbit coupling and excited single-ion levels. In the low-temperature region anisotropy of the magnetic properties dominates and Ising dimer ground-state model gives a more appropriate description. Obtained g-values (g sub p sub a sub r sub a sub l sub l sub e sub l a=5.67, g sub p sub a sub r sub a sub l sub l sub e sub l b=5.73, and g sub p sub e sub r sub p sub e sub n sub d sub i sub c sub u sub l sub a sub r =1.54) con...

  5. Effect of Pleurotus citrinopileatus Polysaccharides on Antioxidant Enzyme Activities and Isozyme Profiles in Liver,Heart and Kidney of Mice with CCl_4-induced Acute Liver Injury%金顶侧耳多糖对CCl_4所致急性肝损伤小鼠肝、心、肾抗氧化酶活性及同工酶影响

    Institute of Scientific and Technical Information of China (English)

    刘俊; 陶明煊; 程光宇; 周斌

    2011-01-01

    Objective:To investigate the effect of Pleurotus citrinopileatus polysaccharides(PCP) on antioxidant enzyme activities and isozyme profiles in the liver,heart and kidney of mice with carbon tetrachloride-induced acute liver injury.Methods:Mice were randomly divided into 6 groups:control group,model group,drug group(bifendate pills,150 mg/(kg·d)),low-dose PCP group(100 mg/(kg·d)),medium-dose PCP group(200 mg/(kg·d)) and high-dose PCP group(400 mg/(kg·d)).All mice were administered for 30 consecutive days,and were fasted for 16 h after the end of the administration period before oral administration of CCl4 dispersed in salad oil for creating CCl4-inducedacute liver injury model.At 24 h postadministration,all mice were sacrificed to assay the activities of ALT,AST and antioxidant enzymes in the blood,liver,heart and kidney and analyze the isozyme profiles of CAT and SOD by gradientpolyacrylamide gel electrophoresis.Results:Compared with the control group,the model group exhibited a significant increase in the activities of serum ALT and AST and a significant decrease in the activities of the investigated antioxidant enzymes in the liver,heart and kidney of mice(P 0.05 or 0.01).PCP administration resulted in a significant decrease in the activities of serum ALT and AST,and the medium-dose and high-dose PCP group exhibited significantly increased activities of CAT,GSH-Px and MnSOD in the liver,heart and kidney and could resume their normal levels.One CAT band was detected in the liver,heart and kidney and CCl4-induced acute liver injury resulted in a significant decrease in its staining intensity.In contrast,the staining intensity of the band was restored to the normal level after PCP administration.Similarly,One MnSOD and three CuZnSOD were detected in the liver and kidney,and PCP administration resulted in an increase in the staining intensity of total SOD and MnSOD,one MnSOD and two CuZnSOD were detected in the

  6. Stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O from measurements made by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    A. T. Brown

    2013-07-01

    Full Text Available Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long-term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS we present calculations of the stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O. The lifetimes were calculated using the slope of the tracer–tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft – along with the effective linear trend of the volume mixing ratio (VMR from tropical ground based AGAGE (Advanced Global Atmospheric Gases Experiment sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (− 26 (18 yr (CFC-12, 35 + (− 11 (7 yr (CCl4, 69 + (− 65 (23 yr (CH3Cl, 123 + (− 53 (28 yr (N2O and 195 + (− 75 (42 yr (CH4. The errors on these values are the weighted 1σ non-systematic errors. Systematic errors were estimated by recalculating lifetimes using VMRs which had been modified to reflect differences between ACE-FTS retrieved VMRs and those from other instruments. The results of these calculations, including systematic errors, were as follows: 113 + (− 32 (20 for CFC-12, 123 + (− 83 (35 for N2O, 195 + (− 139 (57 for CH4, 35 + (− 14 (8 for CCl4 and 69 + (− 2119 (34 yr for CH3Cl. For CH3Cl & CH4 this represents the first calculation of the stratospheric lifetime using data from a space based instrument.

  7. Preventative effects of prostaglandin E1 in combination with iodized olive oil on liver fibrosis after transcatheter arterial chemoembolization in a rabbit model of CCl4-induced liver fibrosis.

    Science.gov (United States)

    Jin, Shuqiang; Cao, Haili; Wang, Kaibing; Li, Ying; Bai, Bin

    2015-06-01

    To explore the preventative effects of prostaglandin E1 (PGE1) on a rabbit model of CCl4-induced liver fibrosis after transcatheter arterial chemoembolization (TACE), we generated a rabbit model of CCl4-induced liver fibrosis by treatment with 40% CCl4 in iodized olive oil for 16 weeks. Body mass and serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total protein (TP), albumin (ALB), albumin:globulin ratio (A:G), total bilirubin (TBIL), and direct bilirubin (DBIL) were measured. After TACE, the levels of hyaluronic acid (HA), procollagen III (PC III), laminin (LN), and collagen IV (IV-C) were measured, and the severity of liver fibrosis as well as the morphology of liver tissues were determined. Body mass in the model group was significantly decreased from 10 to 16 weeks, and the serum levels of ALT, AST, TP, TBIL, and DBIL levels were significantly increased while the model was being generated; the levels of ALB and A:G were significantly decreased. After TACE, serum levels of HA, PC III, and LN in the group injected with 1.0 mL iodized olive oil (Group B) were higher than in the group that were injected with 1.0 mL iodized olive oil + 0.2 mL PGE1 (Group C), whereas the serum levels of IV-C were lower. The severity of liver fibrosis was ameliorated in Group C. The combination of PGE1 and iodized olive oil prevented the development of liver fibrosis following TACE.

  8. Protective Effect of Human Umbilical Cord Mesenchymal Stem Cell on Hepatocirrhosis Rats Induced by CCl4%人脐带间充质干细胞对CCl4致大鼠肝硬化的保护作用研究

    Institute of Scientific and Technical Information of China (English)

    李晓飞; 金旭鹏; 郭莲怡

    2012-01-01

    目的:研究人脐带间充质干细胞(HUC-MSCs)对CCl4致大鼠肝硬化的保护作用及其机制.方法:对大鼠皮下注射CCl4建立肝硬化模型,并于造模成功后继续半剂量注射CCl4,建模成功后随机分为模型组、生理盐水(NS)组、HUC-MSCs组(1×107个/mL),每组24只,后2组通过尾静脉注射,移植相应药物或细胞1 mL,移植后第1、3、5周末观察各组大鼠肝组织病理学变化及其血清中丙氨酸氨基转移酶( ALT)、天冬氨酸氨基转移酶(AST)、胆固醇(CHO)、白蛋白(ALB)、转化生长因子β1(TGF-β1)、肝细胞生长因子(HGF)水平和肝组织中人表皮生长因子受体(EGF-R)的表达情况;另选取8只正常大鼠设为正常对照组.结果:模型组和NS组相似,大鼠肝内胶原纤维增生明显,肝细胞排列紊乱,HUC-MSCs组移植后5周大鼠的肝内胶原纤维增生减少,有较多正常肝细胞;与正常对照组比较,模型组和NS组大鼠的ALT、AST、TGF-β1、HGF水平均明显升高,CHO、ALB含量明显降低(P<0.01);与模型组比较,HUC-MSCs组上述指标均明显好转(P<0.05或P<0.01),其中ALT、ALB、TGF-β1水平与移植后的时间呈正相关;HUC-MSCs组移植后1、3、5周大鼠肝组织中均有人EGF-R的阳性表达.结论:HUC-MSCs可促进肝功能的改善,修复肝硬化损伤的肝脏组织.%OBJECTIVE: To investigate the protective effect of human umbilical cord mesenchymal stem cells (HUC-MSCs) on hepatocirrhosis in rats and its mechanism. METHODS: Rats hepatocirrhosis model was induced by subcutaneous injection of Ccli. Model rats were given half dose of CC14 continuously after modeling. The experimental animals were randomly divided into model group, normal saline (NS) group and HUC-MSCs group (l×107 counts/mL) with 24 rats in each group. The latter 2 groups were given intravenous injection of drug or cell 1 mL via tail vein. After transplantation, respectively at the 1st, 3rd, 5th weekend rats were sacrificed for

  9. 氨基葡萄糖、N-乙酰氨基葡萄糖和小分子壳聚糖对C_2H_5OH和CCl_4所致肝细胞损伤的预防和修复作用%Preventive and recoverable effects of GlcNH_2,GlcNAc and low molecular CS against C_2H_5OH or CCl_4-induced hepatocytes damage

    Institute of Scientific and Technical Information of China (English)

    王永恒; 党奇峰; 陈军; 陈丽媛; 宋磊; 刘成圣

    2011-01-01

    研究了氨基葡萄糖(D-glucosamine,Glc-NH2),N-乙酰氨基葡萄糖(N-acetyl-D-glucosamine,GlcNAc)和小分子壳聚糖(chitosan,CS)对酒精(C2H5OH)或四氯化碳(CCl4)诱导的小鼠肝细胞损伤的预防和修复作用。采用组织块培养法获取小鼠肝细胞,通过对小鼠传代培养过程中肝细胞活性的测定,证实该细胞在第6d达到最佳生长状态。分别用无糖培养基,含500或1000μg/mL GlcNH2、GlcNAc或小分子CS的培养基对肝细胞培养3d后用C2H5OH或CCl%The protective effects of D-glucosamine(GlcNH2),N-acetyl-D-glucosamine(GlcNAc) and low molecular chitosan(CS) on C2H5OH-induced or CCl4-induced mouse hepatocytes damage were investigated in the present study.The mouse hepatocytes were obtained through tissue culture.The cells activity was investigated during the subculture and the results showed the mouse hepatocytes had optimal growth condition at 6d culture.The hepatocytes were exposed to C2H5OH or CCl4 for different times after 3d culture of sugar-free medium,500 or 1000μg/mL of GlcNH2,GlcNAc or low molecular CS medium,and the MTT assay was measured after 6d culture.The results indicated the GlcNH2,GlcNAc and low molecular CS all had preventive effect to CCl4-induced damage and only the low molecular CS had preventive effect to the C2H5OH-induced hepatocytes damage.2000μg/mL of GlcNH2,GlcNAc and low molecular CS all had positively effects on C2H5OH-induced hepatocytes damage recovery,indicating the potential applications in the treatment of C2H5OH-induced liver disease.

  10. Absorption by XeCl* excimer molecules of their own emission of the B-X transition (λ = 308 nm) in a dense Ar-Xe-CCl4 medium upon pumping by fast electrons and uranium-235 fission fragments

    Science.gov (United States)

    Mis'kevich, A. I.; Dyuzhov, Yu. A.; Suvorov, A. A.

    2016-08-01

    Luminescence of dense Ar-Xe-CCl4 gas mixtures with a low CCl4 content upon pumping by fast electrons and uranium-235 fission fragments is studied by spectroscopic methods. It is found that, in a cell with a resonator tuned to the B-X transition of the XeCl* molecule (λ = 308 nm), the D-state population of the XeCl* excimer molecule (the D-X transition, λ = 235 nm) depends on the B-state population and increases by many times with increasing B-state population of the XeCl* molecule. The stimulated absorption coefficient k = 1.2 × 10-16 of B-X transition emission of the XeCl* molecule (λmax = 308 nm), which leads to population of the D-state of this molecule, and the coefficient of amplification μ = 2.5 × 10-4 cm-1 of B-X transition emission of the Xe Cl* molecule (λ = 308 nm) are measured upon pumping by uranium- 235 fission fragments with the specific energy input into the gas medium of ~60 mJ/cm3 and a specific power of energy input of about 240 W/cm3.

  11. TA1 oncofetal rat liver cDNA and putative amino acid permease: temporal correlation with c-myc during acute CCl4 liver injury and variation of RNA levels in response to amino acids in hepatocyte cultures.

    Science.gov (United States)

    Shultz, V D; Campbell, W; Karr, S; Hixson, D C; Thompson, N L

    1999-01-01

    TA1 is a rat liver oncofetal cDNA and a member of an emerging family of evolutionarily conserved molecules with homology to amino acid transporters and permeases. The aim of these studies was to characterize the regulation and role of TA1 in acute rat liver injury by examining its relation to regeneration and metabolic stress. Following a single dose of CCl4, TA1 message was expressed 3-48 h. The major 3.3-kb TA1 transcript correlated temporally with c-myc expression. A novel 2.9-kb TA1 transcript was expressed more variably 24-48 h. TA1 protein was restricted to hepatocytes in G0 and G1 phases of the cell cycle. Relative to CCl4, a much smaller increase in TA1 was noted after partial hepatectomy and TA1 preceded the peak of c-myc expression. In vitro TA1 was not induced in hepatocytes by EGF or the acute-phase cytokines IL-6 and TNF-alpha, but was found to be modulated in response to amino acid availability. TA1 expression increased in media without arginine and glutamine and was repressed by total amino acid levels 5-fold over basal MEM. Together, these results contrast with the constitutive expression observed in transformed cells and suggest an adaptive role for TA1 during liver injury.

  12. p62 Is Required for Stem Cell/Progenitor Retention through Inhibition of IKK/NF-κB/Ccl4 Signaling at the Bone Marrow Macrophage-Osteoblast Niche

    Directory of Open Access Journals (Sweden)

    Kyung Hee Chang

    2014-12-01

    Full Text Available In the bone marrow (BM, hematopoietic progenitors (HPs reside in specific anatomical niches near osteoblasts (Obs, macrophages (MΦs, and other cells forming the BM microenvironment. A connection between immunosurveillance and traffic of HP has been demonstrated, but the regulatory signals that instruct the immune regulation of HP circulation are unknown. We discovered that the BM microenvironment deficiency of p62, an autophagy regulator and signal organizer, results in loss of autophagic repression of macrophage contact-dependent activation of Ob NF-κB signaling. Consequently, Ob p62-deficient mice lose bone, Ob Ccl4 expression, and HP chemotaxis toward Cxcl12, resulting in egress of short-term hematopoietic stem cells and myeloid progenitors. Finally, Ccl4 expression and myeloid progenitor egress are reversed by deficiency of the p62 PB1-binding partner Nbr1. A functional “MΦ-Ob niche” is required for myeloid progenitor/short-term stem cell retention, in which Ob p62 is required to maintain NF-κB signaling repression, osteogenesis, and BM progenitor retention.

  13. Stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O from measurements made by the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS

    Directory of Open Access Journals (Sweden)

    P. F. Bernath

    2013-02-01

    Full Text Available Long lived halogen-containing compounds are important atmospheric constituents since they can act both as a source of chlorine radicals, which go on to catalyse ozone loss, and as powerful greenhouse gases. The long term impact of these species on the ozone layer is dependent on their stratospheric lifetimes. Using observations from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS we present calculations of the stratospheric lifetimes of CFC-12, CCl4, CH4, CH3Cl and N2O. The lifetimes were calculated using the slope of the tracer-tracer correlation of these species with CFC-11 at the tropopause. The correlation slopes were corrected for the changing atmospheric concentrations of each species based on age of air and CFC-11 measurements from samples taken aboard the Geophysica aircraft – along with the effective linear trend of the VMR from tropical ground-based AGAGE sites. Stratospheric lifetimes were calculated using a CFC-11 lifetime of 45 yr. These calculations produced values of 113 + (− 26 (18 yr (CFC-12, 35 + (− 11 (7 yr (CCl4, 195 + (− 75 (42 yr (CH4, 69 + (− 65 (23 yr (CH3Cl and 123 + (− 53 (28 yr (N2O. The errors on these values are the weighted 1-σ non-systematic errors. The stratospheric lifetime of CH3Cl represents the first calculations of the stratospheric lifetime of CH3Cl using data from a space based instrument.

  14. 纳米红色元素硒对CCl4诱导小鼠急性肝损伤的保护作用%The protective effect of nano red elemental selenium on acute liver injury in mice induced by CCl4

    Institute of Scientific and Technical Information of China (English)

    张劲松; 高学云; 张立德

    2001-01-01

    @@ 已知亚硒酸钠和硒蛋氨酸等硒化合物有较高生物活性和毒性,灰和黑色零价元素硒几乎无生物活性和毒性[1]。对于零价元素硒中的红色元素硒,目前缺乏研究,一般将其视为与灰和黑色元素硒类同,无生物利用价值[2]。纳米粒子有大量特性[3],纳米红色元素硒以蛋白质为核,以红色元素硒为膜和以蛋白质为分散剂的新型纳米粒子。本文研究其对CCl4诱导小鼠急性肝损伤保护作用,考查其生物利用和药用价值。 1 材料与方法 1.1 纳米红色元素硒通过蛋白质控制元素硒原子聚合,形成以蛋白质为核,以红色元素硒为膜和以蛋白质为分散剂的纳米红色元素硒粒子。经透射电镜观察约100个粒子直径,其尺度范围为20~60 nm,算术平均尺度为36 nm(图1),其X光电子能谱(XPS)电子结合能为55.3 eV,为零价元素硒(图2)。 1.2 试剂 2、3-二氨基萘(DAN)为Sigma公司产品,其余为国产分析或优级纯试剂。 1.3 动物昆明种小鼠,体重21.8±2.1 g,♀♂各半,购自安徽医科大学动物中心。

  15. Quadra-Quantum Dots and Related Patterns of Quantum Dot Molecules: Basic Nanostructures for Quantum Dot Cellular Automata Application

    Directory of Open Access Journals (Sweden)

    Somsak Panyakeow

    2010-10-01

    Full Text Available Laterally close-packed quantum dots (QDs called quantum dot molecules (QDMs are grown by modified molecular beam epitaxy (MBE. Quantum dots could be aligned and cross hatched. Quantum rings (QRs created from quantum dot transformation during thin or partial capping are used as templates for the formations of bi-quantum dot molecules (Bi-QDMs and quantum dot rings (QDRs. Preferable quantum dot nanostructure for quantum computation based on quantum dot cellular automata (QCA is laterally close-packed quantum dot molecules having four quantum dots at the corners of square configuration. These four quantum dot sets are called quadra-quantum dots (QQDs. Aligned quadra-quantum dots with two electron confinements work like a wire for digital information transmission by Coulomb repulsion force, which is fast and consumes little power. Combination of quadra-quantum dots in line and their cross-over works as logic gates and memory bits. Molecular Beam Epitaxial growth technique called 'Droplet Epitaxy' has been developed for several quantum nanostructures such as quantum rings and quantum dot rings. Quantum rings are prepared by using 20 ML In-Ga (15:85 droplets deposited on a GaAs substrate at 390'C with a droplet growth rate of 1ML/s. Arsenic flux (7'8'10-6Torr is then exposed for InGaAs crystallization at 200'C for 5 min. During droplet epitaxy at a high droplet thickness and high temperature, out-diffusion from the centre of droplets occurs under anisotropic strain. This leads to quantum ring structures having non-uniform ring stripes and deep square-shaped nanoholes. Using these peculiar quantum rings as templates, four quantum dots situated at the corners of a square shape are regrown. Two of these four quantum dots are aligned either or, which are preferable crystallographic directions of quantum dot alignment in general.

  16. 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 .

  17. Administration of Myelin Basic Protein Peptides Encapsulated in Mannosylated Liposomes Normalizes Level of Serum TNF-α and IL-2 and Chemoattractants CCL2 and CCL4 in Multiple Sclerosis Patients

    Directory of Open Access Journals (Sweden)

    Yakov Lomakin

    2016-01-01

    Full Text Available We have previously shown that immunodominant MBP peptides encapsulated in mannosylated liposomes (Xemys effectively suppressed experimental allergic encephalomyelitis (EAE. Within the frames of the successfully completed phase I clinical trial, we investigated changes in the serum cytokine profile after Xemys administration in MS patients. We observed a statistically significant decrease of MCP-1/CCL2, MIP-1β/CCL4, IL-7, and IL-2 at the time of study completion. In contrast, the serum levels of TNF-α were remarkably elevated. Our data suggest that the administration of Xemys leads to a normalization of cytokine status in MS patients to values commonly reported for healthy subjects. These data are an important contribution for the upcoming Xemys clinical trials.

  18. Administration of Myelin Basic Protein Peptides Encapsulated in Mannosylated Liposomes Normalizes Level of Serum TNF-α and IL-2 and Chemoattractants CCL2 and CCL4 in Multiple Sclerosis Patients.

    Science.gov (United States)

    Lomakin, Yakov; Belogurov, Alexey; Glagoleva, Irina; Stepanov, Alexey; Zakharov, Konstantin; Okunola, John; Smirnov, Ivan; Genkin, Dmitry; Gabibov, Alexander

    2016-01-01

    We have previously shown that immunodominant MBP peptides encapsulated in mannosylated liposomes (Xemys) effectively suppressed experimental allergic encephalomyelitis (EAE). Within the frames of the successfully completed phase I clinical trial, we investigated changes in the serum cytokine profile after Xemys administration in MS patients. We observed a statistically significant decrease of MCP-1/CCL2, MIP-1β/CCL4, IL-7, and IL-2 at the time of study completion. In contrast, the serum levels of TNF-α were remarkably elevated. Our data suggest that the administration of Xemys leads to a normalization of cytokine status in MS patients to values commonly reported for healthy subjects. These data are an important contribution for the upcoming Xemys clinical trials.

  19. A Modified Potential Method for Electrons Scattering Total Cross Section Calculations on Several Molecules at 30 ~ 5000 eV: CF4, CCl4, CFCl3, CF2Cl2, and CF3Cl

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A complex optical model potential modified by the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is employed to calculate the total cross sections (TCSs) for electrons scattering from several molecules (CF4, CCl4, CFCl3, CF2 Cl2, and CF3 Cl) over an incident energy range 30 ~ 5000 eV using the additivity rule model at Hartree-Fock level. The quantitative TCSs are compared with those obtained by experiments and other theories wherever available, and good agreement is obtained above 100 eV.It is shown that the modified potential can successfully calculate the TCSs of electron-molecule scattering over a wide energy range, especially at lower energies.

  20. Nanometer range correlations between molecular orientations in liquids of molecules with perfect tetrahedral shape: CCl4, SiCl4, GeCl4, and SnCl4

    Science.gov (United States)

    Pothoczki, Sz.; Temleitner, L.; Jóvári, P.; Kohara, S.; Pusztai, L.

    2009-02-01

    Neutron and x-ray weighted total scattering structure factors of liquid carbon, silicon, germanium, and tin tetrachlorides, CCl4, SiCl4, GeCl4, and SnCl4, have been interpreted by means of reverse Monte Carlo modeling. For each material the two sets of diffraction data were modeled simultaneously, thus providing sets of particle coordinates that were consistent with two experimental structure factors within errors. From these particle configurations, partial radial distribution functions, as well as correlation functions characterizing mutual orientations of molecules as a function of distance between molecular centers were calculated. Via comparison with reference systems, obtained by hard sphere Monte Carlo simulations, we demonstrate that orientational correlations characterizing these liquids are much longer ranged than expected, particularly in carbon tetrachloride.

  1. Nanometer range correlations between molecular orientations in liquids of molecules with perfect tetrahedral shape: CCl(4), SiCl(4), GeCl(4), and SnCl(4).

    Science.gov (United States)

    Pothoczki, Sz; Temleitner, L; Jóvári, P; Kohara, S; Pusztai, L

    2009-02-14

    Neutron and x-ray weighted total scattering structure factors of liquid carbon, silicon, germanium, and tin tetrachlorides, CCl(4), SiCl(4), GeCl(4), and SnCl(4), have been interpreted by means of reverse Monte Carlo modeling. For each material the two sets of diffraction data were modeled simultaneously, thus providing sets of particle coordinates that were consistent with two experimental structure factors within errors. From these particle configurations, partial radial distribution functions, as well as correlation functions characterizing mutual orientations of molecules as a function of distance between molecular centers were calculated. Via comparison with reference systems, obtained by hard sphere Monte Carlo simulations, we demonstrate that orientational correlations characterizing these liquids are much longer ranged than expected, particularly in carbon tetrachloride.

  2. ACEI attenuates the progression of CCl4-induced rat hepatic fibrogenesis by inhibiting TGF-β1, PDGF-BB, NF-κB and MMP-2,9

    Institute of Scientific and Technical Information of China (English)

    Xu Li; Ying Meng; Xi-Shan Yang; Ling-Fei Mi; Shao-Xi Cai

    2005-01-01

    AIM: Angiotensin Ⅱ has pro-fibrotic function in the liver.Blockade of the renin-angiotensin-aldosterone-system (RAAS) attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiotensinconverting enzyme inhibitor (ACEI) on the progression of rat hepatic fibrosis.METHODS: Forty male Wistar rats were divided into three groups. Model group (Mo): The rats were injected subcutaneously with 40% of CCl4 0.25 mL/100 g. Perindopril group (Pe): The rats were injected subcutaneously with administrated. Control group (Nc): the rats were treated with olive oil only. After 4 and 6 wk, the rats were killed.The liver sections were stained with Masson. The protein expressions of AT1R, TGF-β1 and PDGF-BB were examined by Western blot. Nuclear factor κB (NF-κB) DNA binding activity was examined by EMSA (Electrophoretic gel mobility shift assay). Matrix metalloproteinase-2,9(MMP-2,9) activity was assessed by zymography. Serum laminin (LN) and hyaluronic acid (HA) were measured using radioimmunoassays.RESULTS: Using Western blot, we clearly provided direct evidence for the expression of AT1R in liver. The expression was up-regulated when fibrogenesis occurred. Perindopril treatment significantly reduced mean fibrosis score,protein levels of AT1R, TGF-β1 and PDGF-BB, serum levels of HA and LN, and the activity of MMP-2,9. NF-κB DNA binding activity markedly increased in model group, perindopril treatment considerably reduced NF-κB DNA binding activity.CONCLUSION: Perindopril attenuates CCl4-induced hepatic fibrogenesis of rat by inhibiting TGF-β1, PDGF-BB,NF-κB and MMP-2,9.

  3. 门静脉灌注胶原酶逆转四氯化碳致实验兔肝硬化%Portal administration of collagenase reverse liver cirrhosis in rabbit CCl4 model

    Institute of Scientific and Technical Information of China (English)

    邱慧彬; 金博; 孙涛; 于晓红; 杨英祥; 付山峰; 路平

    2011-01-01

    目的 观察门静脉灌注胶原酶对逆转兔实验性肝硬化的作用。方法 实验动物分4组,1组:四氯化碳注射12周后行门静脉置管,1周后开始门静脉灌注胶原酶4周;2组:四氯化碳注射12周后行门静脉置管,1周后开始门静脉灌注生理盐水4周;3组:橄榄油注射12周后行门静脉置管,1周后开始门静脉灌注胶原酶4周;4组:橄榄油注射12周后行门静脉置管,1周后开始门静脉灌注生理盐水4周。以上各组取肝组织,用氯胺T法检测门静脉灌注实验前后肝组织的羟脯氨酸含量及肝组织的病理检查。结果 经过的四氯化碳(CCL4)注射和胶原酶门静脉灌注后,应用胶原酶灌注的动物肝羟脯氨酸含量显著低于用生理盐水灌注的对照组,肝组织学检查也显示胶原酶治疗后肝硬化消退,肝肾功能检查未发现胶原酶的毒性反应。结论 门静脉灌注胶原酶可以促进已形成的肝硬化向正常肝组织结构逆转,并未发现对肝、肾组织毒性反应。%Objective To investigate whether portal collagenase administration can reverse liver cirrhosis. Methods Rabbits divided into 4 groups; group 1: Rabbits received carbon tetrachloride (CC14) subcutaneously (sc) for 12 weeks,then have an operation to put an cannulation in portal vein, collagenase portally for 4 weeks, group 2: Rabbits received CC14 sc for 12 weeks, then have an operation to put an cannulation in portal vein, normal saline portally for 4 weeks, group 3: Rabbits received olive oil sc for 12 weeks,then have an operation to put an cannulation in portal vein collagenase portally for 4 weeks, group 4: Rabbits received olive oil sc for 12 weeks,then have an operation to put an cannulation in portal vein normal saline portally for 4 weeks. Then take tissues of liver, portal vein, brain,kidney, lung and heart in 4 groups. After the zoopery,use chloramine T to test the hydroxypro-line content in liver tissues after

  4. 炉料浸泡法制备低羟基含量锗酸盐玻璃%Low OH content germanate glass prepared by batch soaking process in CCl4

    Institute of Scientific and Technical Information of China (English)

    肖卓豪; 陈媛媛; 左成钢; 卢安贤

    2008-01-01

    CCl4为除水剂,采用炉料浸泡处理工艺制备40GeO2-30SiO2-12Al2O3-6BaO-6CaO-6MgO光学玻璃,研究该工艺对锗酸盐玻璃的红外透过性能以及析晶行为的影响.结果表明,锗酸盐玻璃中OH吸收峰位于3 338 /cm(3.0 μm)附近,通过Gauss分解将其分解为5个单峰并分别对其进行分析,认为锗酸盐玻璃中羟基振动频率的红移是由氢键强度变弱引起的.红外光谱分析表明,采用普通工艺制备的锗酸盐玻璃OH吸收系数为1.71/cm,而处理后玻璃OH吸收系数减少至0.25/cm.对样品的DTA与XRD分析表明,采用新工艺制备的玻璃中由于残留氯离子的存在,起到成核剂的作用,降低玻璃的析晶温度,提高玻璃的析晶速率.氯化物的引入使得玻璃中晶粒形貌由岛状转变为板状,提高玻璃的析晶程度.

  5. Cyclic RGD-peptide-modified nanoliposome significantly reduced the effective dosage and administration frequency of oxymatrine on CCl4-induced hepatic fibrosis in rats%RGD环肽修饰纳米脂质体显著降低氧化苦参碱抗大鼠四氯化碳肝纤维化有效剂量与用药频次

    Institute of Scientific and Technical Information of China (English)

    唐东; 吴建新; 陆伟跃; 陈源文; 葛文松; 朱长红; 周韵斓; 熊敏莉; 范建高

    2011-01-01

    Objective To investigate whether cRGD-NL-OM could reduce the effective dosage and administration frequency of oxymatrine on carbon tetrachloride ( CCl4)-induced hepatic fibrosis in rats by structuring cyclic RGD-pep-tide modified nanoliposome (cRGD-NL) to encapsulate oxymatrine and comparing the antifibrotic effect between low dosage OM (2 mg/kg, q2w) alone and oxymatrine nanoliposome ( with or without cRGD modification) delivering similiar amount of oxymatrine. Methods Sprague-Dawely rats were divided into 6 groups (n = 8 per group): normal group,model (CCl4) group, NL-treated (CCl4 + NL) group, OM-treated ( CCl4 + OM) group, NL-OM-treated (CCl4 + NL-OM) group and cRGD-NL-OM-treated ( CCl4 + cRGD-NL-OM) group. After modeling for 4 weeks, corresponding drugs or vehicles were given twice a week for another 4 weeks in each group (OM 2 mg/kg body mass). At the end of 8th week, all animals were sacrificed to sample serum and livers. HE and Masson staining were performed for evaluation of liver histopathological changes;liver function and collagen metabolism status were determined by biochemical analysis and ELISA respectively; collagen type 1 alpha 2 (COL1 A2) mRNA was measured by quantitative real-time PCR; the expression of α-smooth muscle actin (α-SMA) was detected by Western blot. Results Compared with model group,cRGD-NL-OM group and NL-OM treatment group significantly improved the serum indexes and liver histopathology,COL1A2 mRNA expression and α-SMA protein level also significantly decreased in the two groups. Moreover, cRGD-NL-OM treatment group showed further improvement than NL-OM-treated group. In contrast, NL-treated group and OM-treated group showed no significant improvement compared with model group. Conclusion cRGD-NL-OM could significantly reduce the effective antifibrotic dosage and administration frequency of oxymatrine. This new compound may be promising for clinical application.%目的构建RGD环肽修饰纳米脂质体(cRGD-NL),利用其包

  6. The fate of atmospheric phosgene and the stratospheric chlorine loadings of its parent compounds: CCl4, C2Cl4, C2HCL3, CH3CCl3, and CHCl3

    Science.gov (United States)

    Kindler, T. P.; Chameides, W. L.; Wine, P. H.; Cunnold, D. M.; Alyea, F. N.; Franklin, J. A.

    1995-01-01

    A study of the tropospheric and stratospheric cycles of phosgene is carried out to determine its fate and ultimate role in controlling the ozone depletion potentials of its parent compounds. Tropospheric phosgene is produced from the OH-initiated oxidation of C2Cl4, CH3CCl3, CHCl3, and C2HCl3. Simulations using a two-dimensional model indicate that these processes produce about 90 pptv/yr of tropospheric phosgene with an average concentration of about 18 pptv, in reasonable agreement with observations. We estimate a residence time of about 70 days for tropospheric phosgene, with the vast majority being removed by hydrolysis in cloudwater. Only about 0.4% of the phosgene produced in the troposphere avoids wet removal and is transported to the stratosphere, where its chlorine can be released to participate in the catalytic destruction of ozone. Stratospheric phosgene is produced from the photochemical degradation of CCl4, C2Cl4, CHCl3, and CH3CCl3 and is removed by photolysis and downward transport to the troposphere. Model calculations, in good agreement with observations, indicate that these processes produce a peak stratospheric concentration of about 25-30 pptv at an altitude of about 25 km. In contrast to tropospheric phosgene, stratospheric phosgene is found to have a lifetime against photochemical removal of the order of years. As a result, a significant portion of the phosgene that is produced in the stratosphere is ultimately returned to the troposphere, where it is rapidly removed by clouds. This phenomenon effectively decreases the amount of reactive chlorine injected into the stratosphere and available for ozone depletion from phosgene's parent compounds. A similar phenomenon due to the downward transport of stratospheric COFCl produced from CFC-11 is estimated to cause a 7% decrease in the amount of reactive chlorine injected into the stratosphere from this compound. Our results are potentially sensitive to a variety of parameters, most notably the rate

  7. Genetically graded activation of Nrf2 protects mice against carbon tetrachloride-induced hepatotoxicity%Nrf2抗氧化损伤通路在CCl4所致小鼠肝毒性中的保护作用

    Institute of Scientific and Technical Information of China (English)

    陆远富; Connie Wu; 刘杰; Curtis Dean Klaassen

    2015-01-01

    目的 观察核转录相关因子2(nuclear factor erythroid 2-related factor 2,Nrf2)抗氧化损伤通路对四氯化碳(CCl4)所致小鼠肝毒性的保护作用.方法 选取Nrt2-null、Wild-type、Keap1-KD、Keapl-HKO小鼠,按基因型分为4组,分别给予40 mg/kg CCl4腹腔注射,腹腔注射生理盐水(10 mL/kg)作对照,16 h后收集血浆和肝组织样本,检测血中谷丙转氨酶(alanine transaminase,ALT)和乳酸脱氢酶(lactic dehydrogenase,LDH)活性以及肝组织中丙二醛(malondialdehyde,MDA)含量;HE染色观察肝组织病理学变化,Real-time PCR和Western blot法检测相关基因表达.结果 CCl4增加Nrf2-null组和Wild-type组血中ALT、LDH活性及肝组织MDA含量,同时造成肝组织病理损伤,而在Keap1-KD组和Keap1-HKO组影响不明显;Nrf2因子靶基因(Nqo1和Gclc)在CCl4的诱导表达逐渐增高(顺序为Nrf2-null、Wild-type、Keapl-KD、Keap1-HKO),继而使炎症因子、内质网应激基因、细胞凋亡基因、细胞坏死基因的表达(mKC、MIP-2、IL-1β、TNFα、Gadd45、Chop10、Bax、Caspase3、Mcl、Noxa)按Nrf2-null、Wild-type、Keap1-KD、Keap1-HKO顺序逐渐下降.结论 Nrf2因子激活保护CCl4所致小鼠肝损伤反应.

  8. CMS Centre at CERN

    CERN Multimedia

    2007-01-01

    A new "CMS Centre" is being established on the CERN Meyrin site by the CMS collaboration. It will be a focal point for communications, where physicists will work together on data quality monitoring, detector calibration, offline analysis of physics events, and CMS computing operations. Construction of the CMS Centre begins in the historic Proton Synchrotron (PS) control room. The historic Proton Synchrotron (PS) control room, Opened by Niels Bohr in 1960, will be reused by CMS to built its control centre. TThe LHC@FNAL Centre, in operation at Fermilab in the US, will work very closely with the CMS Centre, as well as the CERN Control Centre. (Photo Fermilab)The historic Proton Synchrotron (PS) control room is about to start a new life. Opened by Niels Bohr in 1960, the room will be reused by CMS to built its control centre. When finished, it will resemble the CERN Contro...

  9. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    Semiconductor quantum dots ("solid-state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra. Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dot states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  10. Quantum dot spectroscopy

    DEFF Research Database (Denmark)

    Leosson, Kristjan

    1999-01-01

    Semiconductor quantum dots ("solid state atoms") are promising candidates for quantum computers and future electronic and optoelectronic devices. Quantum dots are zero-dimensional electronic systems and therefore have discrete energy levels, similar to atoms or molecules. The size distribution...... of quantum dots, however, results in a large inhomogeneous broadening of quantum dot spectra.Work on self-assembled InGaAs/GaAs quantum dots will be presented. Properties of atom-like single-dots states are investigated optically using high spatial and spectral resolution. Single-dot spectra can be used...

  11. Probing individual quantum dots: noise in self-assembled systems.

    Science.gov (United States)

    Vicaro, K O; Gutiérrez, H R; Seabra, A C; Schulz, P A; Cotta, M A

    2009-11-01

    In this work we explore the noise characteristics in lithographically-defined two terminal devices containing self-assembled InAs/InP quantum dots. The experimental ensemble of InAs dots show random telegraph noise (RTN) with tuneable relative amplitude-up to 150%-in well defined temperature and source-drain applied voltage ranges. Our numerical simulation indicates that the RTN signature correlates with a very low number of quantum dots acting as effective charge storage centres in the structure for a given applied voltage. The modulation in relative amplitude variation can thus be associated to the altered electrostatic potential profile around such centres and enhanced carrier scattering provided by a charged dot.

  12. Morphology of portal hypertension at the early stage of liver damage induced by CCl4:an experimental study with dogs%四氯化碳诱导犬早期肝损害所致门静脉高压的形态学观察

    Institute of Scientific and Technical Information of China (English)

    张日平; 张伟辉; 薛东波; 魏云巍

    2004-01-01

    目的探讨实验性犬肝脏早期损害所致的门静脉高压形成的形态学基础.方法以小剂量四氯化碳(CCl4)腹腔内注射诱导犬早期肝损害,制备门静脉高压犬模型.通过光镜、电镜观察肝脏形态学的改变.结果腹腔内注射CCl4 7周后,共有15头犬形成门静脉高压(门静脉压力22.7 cm H2O±1.5 cm H2O,1 cm H2O=0.098 kPa,与给药前相比,P<0.05).HE染色示肝脏损害轻微.Masson染色、电镜,示肝窦毛细血管化.α-平滑肌肌动蛋白(α-SMA)免疫组化染色示肝星形细胞(HSC)大量活化.结论肝脏受损早期,门静脉高压形成的可能原因是肝窦毛细血管化和HSC活化所致的肝窦血流阻力增加.

  13. Connecting dots

    DEFF Research Database (Denmark)

    Murakami, Kyoko; Jacobs, Rachel L.

    2017-01-01

    of connecting the dots of recalled moments of individual family members lives and is geared towards building a family’s shared future for posterity. Lastly, we consider a wider implication of family reminiscence in terms of human development. http://www.infoagepub.com/products/Memory-Practices-and-Learning...... and Middleton, 1995). A reminiscence conversation is a dynamic talk-in-interaction, which can produce valuable learning experience for the participants involved. Reminiscence talk contains rich, personal, historic data that can reveal and inform family members of an unknown past. In this seminar/chapter, we...... shall present a discursive approach, a methodology that captures the dynamics of reminiscence. We analyse collected conversational data of British family members reminiscing on their past as a joint family activity. Through such talk-in-interaction, the family members develop continuity within...

  14. Client Centred Desing

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Nielsen, Janni; Levinsen, Karin

    2008-01-01

    In this paper we argue for the use of Client Centred preparation phases when designing complex systems. Through Client Centred Design human computer interaction can extend the focus on end-users to alse encompass the client's needs, context and resources....

  15. 栀子柏皮汤不同配伍对四氯化碳诱导肝纤维化小鼠的治疗作用%Therapeutical effects of Zhizi Bopi Decoction and its compatibility on CCl4 induced hepatic fibrosis in mice

    Institute of Scientific and Technical Information of China (English)

    钱正月; 李俊; 黄成; 孟晓明; 马陶陶; 陈昭琳

    2016-01-01

    Objective To study the anti-hepatofibrotic effects of Zhizi Bopi Decoction and its compatibility on liver fibrosis. Methods The model of mouse liver fibrosis which was induced by carbon tetraehlofide ( CCl4 ) was used to investigate the effects of Zhizi Bopi Decoction and its compatibility by gavage. Indicators of hepatic fibrosis and inflammation were detected with automated biochemistry analyzer and liver fibrosis of the mice was assessed by Mas-son staining and HE staining. Meanwhile, the protein levels of collagen typeⅠ and α-smooth muscle actin (α-SMA) were evaluated by Western blot analysis. Results Zhizi Bopi Decoction and each different treatment group could evidently inhibit the increased serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), hydroxyproline ( Hyp) and hyaluronic acid ( HA) activities, and improve the pathological changes of mouse livers. Furthermore, the therapeutic effects on liver fibrosis induced by CCl4 in mice were primarily ascribed to the syner-gic effect of Gardenia jasminoides Ellis, Cortex phellodendri and Glycyrrhizae Radix et Rhizoma ( P<0. 01 ) . And they could obviously reduce the protein expression levels of collagen typeⅠandα-SMA in the liver ( P<0. 01 ) . In addition, Zhizi Bopi Decoction could also obviously reduce the contents of transforming growth factor-beta ( TGF-β) . Conclusion Zhizi Bopi Decoction and its compatibility all perform significant anti-fibrotic effects on the liver in different degree, but the compatibility of Gardenia jasminoides Ellis, Cortex phellodendri and Glycyrrhizae Radix et Rhizoma exert the most distinctly anti-fibrotic effects among them, possibly by reducing the contents of TGF-β.%目的 研究栀子柏皮汤不同配伍组合的抗肝纤维化药理作用. 方法 采用四氯化碳( CCl4 )引起的肝纤维化小鼠模型观察栀子柏皮汤各配伍组的抗肝纤维化作用,同时给予不同配伍的栀子柏皮汤进行灌胃治疗. 生化检测相关肝纤

  16. The IGU Knowledge Centre

    NARCIS (Netherlands)

    Huizing, Bernardus

    2005-01-01

    This article describes an innovative service for members of the International Gas Union - IGU. The IGU Knowledge Centre provides members with relevant information and data. In this article is described why, how and where.

  17. Virtual particle therapy centre

    CERN Multimedia

    2015-01-01

    Particle therapy is an advanced technique of cancer radiation therapy, using protons or other ions to target the cancerous mass. This advanced technique requires a multi-disciplinary team working in a specialised centre. 3D animation: Nymus3D

  18. Academic Drug Discovery Centres

    DEFF Research Database (Denmark)

    Kirkegaard, Henriette Schultz; Valentin, Finn

    2014-01-01

    Academic drug discovery centres (ADDCs) are seen as one of the solutions to fill the innovation gap in early drug discovery, which has proven challenging for previous organisational models. Prior studies of ADDCs have identified the need to analyse them from the angle of their economic and organi......Academic drug discovery centres (ADDCs) are seen as one of the solutions to fill the innovation gap in early drug discovery, which has proven challenging for previous organisational models. Prior studies of ADDCs have identified the need to analyse them from the angle of their economic...... their performance....

  19. Town Centre Redevelopment Strategies

    DEFF Research Database (Denmark)

    Vagnby, Bo Hellisen

    After many years of urban growth Danish downtowns are facing some important choices. Shall the stake one-sidedly be on the town centres as driving forces for growth and 'city marketing', or do they still have a role to play in a broader socio-economic context? In the paper we look back on eight...... during late years, where increased internationalisation is in focus and where it seems as if the social dimension of the town centre planning is slipping out of the hands of the urban planners....

  20. From DOT to Dotty

    CERN Document Server

    CERN. Geneva

    2017-01-01

    - Module types are interfaces, which can be abstracted. In this talk Martin will present DOT, a particularly simple calculus that can express systems following these principles. DOT has been developed as the foundation of the next version of Scala. He will also report on dotty, a new Scala compiler that implements the constructs of DOT in its core data structures and that uses the lessons learned to drive Scala’s evolution.

  1. The GSO Data Centre

    CERN Document Server

    Paletou, F; Génot, V; Rouillard, A; Petit, P; Palacios, A; Caux, E; Wakelam, V

    2015-01-01

    Hereafter we describe the activities of the $Grand \\, Sud-Ouest$ Data Centre operated for INSU/CNRS by the OMP-IRAP and the Universit\\'e Paul Sabatier (Toulouse), in a collaboration with the OASU-LAB (Bordeaux) and OREME-LUPM (Montpellier).

  2. Implementing Responsibility Centre Budgeting

    Science.gov (United States)

    Vonasek, Joseph

    2011-01-01

    Recently, institutes of higher education (universities) have shown a renewed interest in organisational structures and operating methodologies that generate productivity and innovation; responsibility centre budgeting (RCB) is one such process. This paper describes the underlying principles constituting RCB, its origin and structural elements, and…

  3. ATLAS Visitors Centre

    CERN Multimedia

    claudia Marcelloni

    2009-01-01

    ATLAS Visitors Centre has opened its shiny new doors to the public. Officially launched on Monday February 23rd, 2009, the permanent exhibition at Point 1 was conceived as a tour resource for ATLAS guides, and as a way to preserve the public’s opportunity to get a close-up look at the experiment in action when the cavern is sealed.

  4. Quantitative analyses of the combined effects of nanored elemental selenium and glucurolactone on formingliver fibrosis induced by CCl4 in rats%纳米红色元素硒与葡萄糖醛酸内酯联用对大鼠肝纤维化形成过程的干预及其定量分析

    Institute of Scientific and Technical Information of China (English)

    郑青山; 张劲松; 桂常青; 王学文; 杨会杰; 李爱华; 汪幼霞; 孙瑞元

    2002-01-01

    目的将纳米红色元素硒(nano red elemental selenium, Nse)与葡萄糖醛酸内酯μglucurolactone,Glu)联用,观察对大鼠肝纤维化形成过程的干预作用,试图通过药物间的相互作用,增效减毒,从而降低硒用量.方法根据权重配方法设计,设立两药不同组合的6个用药组和2个对照组.用CCl4造成大鼠急性肝损伤后开始用药,于用药3wk和6 wk,观察与急慢性肝损伤的相关指标,包括ALT,MDA和PCIII.结果急性肝损伤阶段的短期用药(3wk),宜用大剂量Nse,权重配方法的理论计算提示,Nse 200 μg·kg-1单用即可;两药联合长期使用(6wk),在小剂量就可获效,尤以Nse 100 μg·kg-1 + Glu 50mg·kg-1为好,对大鼠实验性肝纤维化已呈现明显的防治作用,联用Nse和Glu作用强于单用Nse.理论计算认为,Nse和Glu间产生协同作用,优化的组合剂量为Nse100 μg·kg-1 + Glu 60 m g·kg-1(ig).结论 Nse和Glu联合用药,对大鼠CCl4所致的肝纤维化有防治作用,可降低Nse用量.

  5. Observation of the B (s) (0) -> aEuro parts per thousand J/psi I center dot I center dot decay

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M. -O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. Campora; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Akiba, K. Carvalho; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Cheung, S. -F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Dean, C. -T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Faerber, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fohl, K.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frei, C.; Frosini, M.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Garcia Pardinas, J.; Tico, J. Garra; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gotti, C.; Grabalosa Gandara, M.; Graciani Diaz, R.; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koppenburg, P.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. -P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Lemos Cid, E.; Leroy, O.; Lesiak, T.

    2016-01-01

    The B (s) (0) -> aEuro parts per thousand J/psi I center dot I center dot decay is observed in pp collision data corresponding to an integrated luminosity of 3 fb(-1) recorded by the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first observation of this decay channel, wit

  6. Quantum dot density studies for quantum dot intermediate band solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Thomassen, Sedsel Fretheim; Zhou, Dayong; Vitelli, Stefano; Mayani, Maryam Gholami; Fimland, Bjoern-Ove; Reenaas, Turid Worren

    2010-07-01

    Quantum dots (QDs) have been an active area of research for many years and have been implemented in several applications, such as lasers and detectors. During the last years, some attempts have been made to increase the absorption and efficiency of solar cells by inserting QDs into the intrinsic region of pin solar cells. So far, these attempts have been successful in increasing the absorption, but not the cell efficiency. There are probably several reasons for this lack of efficiency increase, but we believe that one important reason is the low density of the implemented QDs. In this work, samples of single layer InAs QDs on n-GaAs(001) substrates have been grown by molecular beam epitaxy (MBE) and we have performed a systematic study of how deposition parameters affect the QD density. The aim is to achieve densities > 1011 cm-2. The nominal substrate temperature (360 - 500 deg. C), the InAs growth rate (0.085 - 1 ML/s) and thickness (2.0 - 2.8 ML) have been varied in a systematic way for two different deposition methods of InAs, i.e. continuous deposition or deposition with interruptions. In addition, we have for the continuous growth samples also varied the As-flux (0.5 - 6 centre dot10-6 torr). Scanning electron microscopy (SEM) has been the main characterization method to determine quantum dot sizes and densities, and atomic force microscopy (AFM) has been used for evaluation of the quantum dot heights. We find that the QD density increases with reduced growth temperature and that it is higher for samples grown continuously than for samples grown with growth interruptions. The homogeneity is also strongly affected by temperature, InAs deposition method and the As-flux. We have observed QD densities as high as 2.5 centre dot1011 cm-2 for the samples grown at the lowest growth temperatures. (Author)

  7. Quantum Dots: Theory

    Energy Technology Data Exchange (ETDEWEB)

    Vukmirovic, Nenad; Wang, Lin-Wang

    2009-11-10

    This review covers the description of the methodologies typically used for the calculation of the electronic structure of self-assembled and colloidal quantum dots. These are illustrated by the results of their application to a selected set of physical effects in quantum dots.

  8. Quantum Dot Solar Cells

    Science.gov (United States)

    Raffaelle, Ryne P.; Castro, Stephanie L.; Hepp, Aloysius; Bailey, Sheila G.

    2002-01-01

    We have been investigating the synthesis of quantum dots of CdSe, CuInS2, and CuInSe2 for use in an intermediate bandgap solar cell. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Bawendi, et. al., in the early 1990's. However, unlike previous work in this area we have also utilized single-source precursor molecules in the synthesis process. We will present XRD, TEM, SEM and EDS characterization of our initial attempts at fabricating these quantum dots. Investigation of the size distributions of these nanoparticles via laser light scattering and scanning electron microscopy will be presented. Theoretical estimates on appropriate quantum dot composition, size, and inter-dot spacing along with potential scenarios for solar cell fabrication will be discussed.

  9. Elderly Care Centre

    Science.gov (United States)

    Wagiman, Aliani; Haja Bava Mohidin, Hazrina; Ismail, Alice Sabrina

    2016-02-01

    The demand for elderly centre has increased tremendously abreast with the world demographic change as the number of senior citizens rose in the 21st century. This has become one of the most crucial problems of today's era. As the world progress into modernity, more and more people are occupied with daily work causing the senior citizens to lose the care that they actually need. This paper seeks to elucidate the best possible design of an elderly care centre with new approach in order to provide the best service for them by analysing their needs and suitable activities that could elevate their quality of life. All these findings will then be incorporated into design solutions so as to enhance the living environment for the elderly especially in Malaysian context.

  10. Tele-centres in Ghana

    DEFF Research Database (Denmark)

    Falch, Morten

    2004-01-01

    Tele-centres offer a low cost opportunity for the many who cannot afford their own phone or Internet connection. This paper presents a field study of tele-centres in Ghana and analyses how they contribute to universal access.......Tele-centres offer a low cost opportunity for the many who cannot afford their own phone or Internet connection. This paper presents a field study of tele-centres in Ghana and analyses how they contribute to universal access....

  11. Study of Tuberculosis cases under RNTCP attending Designated Microscopy Centre at Pravara Rural Hospital, Loni

    Directory of Open Access Journals (Sweden)

    Phalke Deepak Baburao

    2009-12-01

    Full Text Available Pulmonary Tuberculosis is most common form of tuberculosis (TB. The present study was conducted to study the TB cases attending DMC cum DOTS centre at PRH, Loni. It is a retrospective record based study. TB patients information was collected from the record registers at DOTS centre. Out of 611 patients diagnosed, 188 (30% are from the age group 0- 10 years. Extrapulmonary TB patients were more 222(36%. New smear positive TB cases were 196 (32%. Total 61% patients were categorized in CAT- I, 9% in CAT-II & 30% in CAT III. Treatment completion rate was 93.69%. In view of the high success of DOTS strategy, the same is recommended to be continued. For transferred cases, a better system of follow up may be explored for monitoring all these cases.

  12. Binding Energies of Negatively Charged Donors in a Gaussian Potential Quantum Dot

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2005-01-01

    @@ We investigate a negatively charged donor centre (D-) trapped by a quantum dot, which is subjected to a Gaussian potential confinement. Calculations are carried out by using the method of numerical diagonalization of Hamiltonian within the effective-mass approximation. The dependence of the ground state of the negatively charged donor on the dot size and the potential depth is studied. The same calculations performed with the parabolic approximation of the Gaussian potential lead to the results that are qualitatively and quantitatively different.

  13. Graphene quantum dots

    CERN Document Server

    Güçlü, Alev Devrim; Korkusinski, Marek; Hawrylak, Pawel

    2014-01-01

    This book reflects the current status of theoretical and experimental research of graphene based nanostructures, in particular quantum dots, at a level accessible to young researchers, graduate students, experimentalists and theorists. It presents the current state of research of graphene quantum dots, a single or few monolayer thick islands of graphene. It introduces the reader to the electronic and optical properties of graphite, intercalated graphite and graphene, including Dirac fermions, Berry's phase associated with sublattices and valley degeneracy, covers single particle properties of

  14. 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。

  15. Protective Effects of Different Dosing Position of Misgurnus Anguillicaudatus Lyophilized Power on Chemical Liver Injury in Mice Induced by CCl4%泥鳅不同部位冻干粉对小鼠四氯化碳化学性肝损伤保护作用

    Institute of Scientific and Technical Information of China (English)

    商萌萌; 凌去非; 汪务诚; 刘春宇

    2013-01-01

    Objective: To investigate different dosing position of Misgurnus Anguiliicaudatus lyophilized power on chemical liver injury in mice induced by CCl4, screening of the best effective part. Methods: A mouse model of acute liver injury was induced by carbon tetraohloride, determining of serum ALT and AST activities so as to observe different parts of Misgurnus Anguiliicaudatus lyophilized power protective effect. Results: Misgurnus Anguiliicaudatus whole lyophilized power and muscle lyophilized power can significantly reduce the mice serum ALT and AST activities ( P0.05 ) . Conclusion: The Misgurnus Anguiliicaudatus lyophilized power had significant effect on mice liver injury induced by carbon tetrachloride. The effect of Misgurnus Anguiliicaudatus whole lyophilized power is most obvious, which is the main effective part of liver protection.%目的:本文研究不同部位泥鳅冻干粉对小鼠四氯化碳肝损伤的保护作用,筛选有效部位.方法:采用小鼠四氯化碳急性肝损伤模型,测定小鼠血清ALT、AST活性,观察泥鳅不同部位冻干粉的保护作用.结果:泥鳅全冻干粉和泥鳅肌肉冻干粉显著降低小鼠血清中ALT、AST活性(P<0.05),而泥鳅皮冻干粉的作用不明显(P>0.05).结论:泥鳅冻干粉对小鼠四氯化碳肝损伤具有显著的保护作用,其中泥鳅全冻干粉的作用最明显,是泥鳅保肝的主要有效部位.

  16. A cancer help centre.

    Science.gov (United States)

    Daniel, R

    1996-06-01

    The diagnosis of cancer can be shattering to all involved. The treatment of cancer is intense and often very challenging. Prevailing attitudes to cancer are sometimes fearful, negative and depressing. This combination may leave those affected by cancer shocked, disorientated and without hope. Even worse than this, on asking consultants 'What can I do to help myself?' patients are frequently told 'Absolutely nothing'--crushing in one fell swoop their remaining fighting spirit. Not so in the case of Penny Brohn, who, when faced with the diagnosis of breast cancer, travelled the world to find alternative cancer treatments, and having successfully brought her own cancer under control, dedicated her life to creating a Centre for others wishing to fight their disease.

  17. Stavanger Squash Centre, Norway

    Energy Technology Data Exchange (ETDEWEB)

    Rostvik, H. [Sunlab/ABB, Stavanger (Norway)

    1999-07-01

    Although Stavanger is the technological and financial oil-capital of Norway, the Stavanger Squash Centre was until recently the largest solar building in Norway, with 120 m{sup 2} of collectors. The active, building-integrated, solar air collector in the 45 {sup o} roof facing 15 {sup o} east of due south, has now been delivering solar-heated hot water for the showers for 15 years. The solar system consists of several standard products put together in a new way. Monitoring has shown that the system produced 18,000 kWh/m{sup 2} a (150 kWh/m{sub coll} {sup 2}a). If operated as planned, it could have had a solar contribution of 45,000 kWh/a) (375 kWh/m{sub coll} {sup 2}a), resulting in a 19% solar fraction of total demand. (author)

  18. 重组Akt腺病毒对CCl4诱导的肝硬化门静脉高压症大鼠模型的影响%Effects of Ad-myr-HA-Akt on cirrhotic portal hypertension in rats

    Institute of Scientific and Technical Information of China (English)

    邓刚; 黄飞舟; 刘浔阳; 罗成群

    2009-01-01

    Objective To probe the effects of recombinant adenovirus containing Akt on carbon tetrachioride-induced rat liver cirrhosis and portal hypertension. Methods Cirrhosis was induced in rats by a complex method of carbon tetrachloride. Recombinant adenovirus Ad-myr-HA-Akt was produced by homologous recombination in 293 cells. Rats received Ad-myr-HA-Akt via the tail vein at the second and the sixth week respectively. The pathological changes in liver tissues were observed after Van Gieson (VG) staining. Fas antigen in rat livers were determined by immunohistochemical method. The levels of alanine minotransferase( ALT), aspartate aminotransferase ( AST), albumin( ALB ) and hydroxyproline (Hyp) were measured. Fas antigen in rat livers were determined with immunohistochemical method. Expression of Akt, p-Akt, Fas and DR5 were evaluated by Western blotting. Frozen sections of the liver, heart,lung,kidney, brain,spleen and testis were made to examine the expression of enhance green flourescent protein (EGFP) by fluorescence microscopy in EGFP group. After 8-week CCl4 treatment, portal hypertensive rats in the saline group and Ad-Akt group received saline and Ad-myr-HA-Akt via the tail vein respectively. Portal vein pressure, mean arterial pressure and heart rate were measured in all rats on Day 3. Results In comparison with other cirrhosis rats, the pathological changes in the Akt group was markedly attenuated, and the levels of ALT, AST and Hyp were significantly lowered. Western blotting showed that the protein expression of p-Akt in the Akt group was higher significantly as compared with those in the negtive control group, saline group and EGFP group. Western blot also showed that the protein expression of Fas and DR5 in the Akt group was lower significantly. EGFP expression was mainly demonstrated by fluorescence microscopy on the frozen section of liver, very little fluorescene were detected in lung and kidney and there was no detectable EGFP in the other organs

  19. Call Centre- Computer Telephone Integration

    Directory of Open Access Journals (Sweden)

    Dražen Kovačević

    2012-10-01

    Full Text Available Call centre largely came into being as a result of consumerneeds converging with enabling technology- and by the companiesrecognising the revenue opportunities generated by meetingthose needs thereby increasing customer satisfaction. Regardlessof the specific application or activity of a Call centre, customersatisfaction with the interaction is critical to the revenuegenerated or protected by the Call centre. Physical(v, Call centreset up is a place that includes computer, telephone and supervisorstation. Call centre can be available 24 hours a day - whenthe customer wants to make a purchase, needs information, orsimply wishes to register a complaint.

  20. Council celebrates CERN Control Centre

    CERN Multimedia

    2006-01-01

    With the unveiling of its new sign, the CERN Control Centre was officially inaugurated on Thursday 16 March. To celebrate its startup, CERN Council members visited the sleek centre, a futuristic-looking room filled with a multitude of monitoring screens.

  1. Hexagonal graphene quantum dots

    KAUST Repository

    Ghosh, S.

    2016-12-05

    We study hexagonal graphene quantum dots, using density functional theory, to obtain a quantitative description of the electronic properties and their size dependence, considering disk and ring geometries with both armchair and zigzag edges. We show that the electronic properties of quantum dots with armchair edges are more sensitive to structural details than those with zigzag edges. As functions of the inner and outer radii, we find in the case of armchair edges that the size of the band gap follows distinct branches, while in the case of zigzag edges it changes monotonically. This behaviour is further analyzed by studying the ground state wave function and explained in terms of its localisation.

  2. Quantum dot solar cells

    CERN Document Server

    Wu, Jiang

    2013-01-01

    The third generation of solar cells includes those based on semiconductor quantum dots. This sophisticated technology applies nanotechnology and quantum mechanics theory to enhance the performance of ordinary solar cells. Although a practical application of quantum dot solar cells has yet to be achieved, a large number of theoretical calculations and experimental studies have confirmed the potential for meeting the requirement for ultra-high conversion efficiency. In this book, high-profile scientists have contributed tutorial chapters that outline the methods used in and the results of variou

  3. CMCC Data Distribution Centre

    Science.gov (United States)

    Aloisio, Giovanni; Fiore, Sandro; Negro, A.

    2010-05-01

    The CMCC Data Distribution Centre (DDC) is the primary entry point (web gateway) to the CMCC. It is a Data Grid Portal providing a ubiquitous and pervasive way to ease data publishing, climate metadata search, datasets discovery, metadata annotation, data access, data aggregation, sub-setting, etc. The grid portal security model includes the use of HTTPS protocol for secure communication with the client (based on X509v3 certificates that must be loaded into the browser) and secure cookies to establish and maintain user sessions. The CMCC DDC is now in a pre-production phase and it is currently used only by internal users (CMCC researchers and climate scientists). The most important component already available in the CMCC DDC is the Search Engine which allows users to perform, through web interfaces, distributed search and discovery activities by introducing one or more of the following search criteria: horizontal extent (which can be specified by interacting with a geographic map), vertical extent, temporal extent, keywords, topics, creation date, etc. By means of this page the user submits the first step of the query process on the metadata DB, then, she can choose one or more datasets retrieving and displaying the complete XML metadata description (from the browser). This way, the second step of the query process is carried out by accessing to a specific XML document of the metadata DB. Finally, through the web interface, the user can access to and download (partially or totally) the data stored on the storage device accessing to OPeNDAP servers and to other available grid storage interfaces. Requests concerning datasets stored in deep storage will be served asynchronously.

  4. Fuzzy Dot Structure of BG-algebras

    Directory of Open Access Journals (Sweden)

    Tapan Senapati

    2014-09-01

    Full Text Available In this paper, the notions of fuzzy dot subalgebras is introduced together with fuzzy normal dot subalgebras and fuzzy dot ideals of BG-algebras. The homomorphic image and inverse image are investigated in fuzzy dot subalgebras and fuzzy dot ideals of BG-algebras. Also, the notion of fuzzy relations on the family of fuzzy dot subalgebras and fuzzy dot ideals of BG-algebras are introduced with some related properties.

  5. Electron correlations in quantum dots

    CERN Document Server

    Tipton, D L J

    2001-01-01

    Quantum dot structures confine electrons in a small region of space. Some properties of semiconductor quantum dots, such as the discrete energy levels and shell filling effects visible in addition spectra, have analogies to those of atoms and indeed dots are sometimes referred to as 'artificial atoms'. However, atoms and dots show some fundamental differences due to electron correlations. For real atoms, the kinetic energy of electrons dominates over their mutual Coulomb repulsion energy and for this reason the independent electron approximation works well. For quantum dots the confining potential may be shallower than that of real atoms leading to lower electron densities and a dominance of mutual Coulomb repulsion over kinetic energy. In this strongly correlated regime the independent electron picture leads to qualitatively incorrect results. This thesis concentrates on few-electron quantum dots in the strongly correlated regime both for quasi-one-dimensional and two-dimensional dots in a square confining p...

  6. 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

  7. Colloidal Double Quantum Dots.

    Science.gov (United States)

    Teitelboim, Ayelet; Meir, Noga; Kazes, Miri; Oron, Dan

    2016-05-17

    Pairs of coupled quantum dots with controlled coupling between the two potential wells serve as an extremely rich system, exhibiting a plethora of optical phenomena that do not exist in each of the isolated constituent dots. Over the past decade, coupled quantum systems have been under extensive study in the context of epitaxially grown quantum dots (QDs), but only a handful of examples have been reported with colloidal QDs. This is mostly due to the difficulties in controllably growing nanoparticles that encapsulate within them two dots separated by an energetic barrier via colloidal synthesis methods. Recent advances in colloidal synthesis methods have enabled the first clear demonstrations of colloidal double quantum dots and allowed for the first exploratory studies into their optical properties. Nevertheless, colloidal double QDs can offer an extended level of structural manipulation that allows not only for a broader range of materials to be used as compared with epitaxially grown counterparts but also for more complex control over the coupling mechanisms and coupling strength between two spatially separated quantum dots. The photophysics of these nanostructures is governed by the balance between two coupling mechanisms. The first is via dipole-dipole interactions between the two constituent components, leading to energy transfer between them. The second is associated with overlap of excited carrier wave functions, leading to charge transfer and multicarrier interactions between the two components. The magnitude of the coupling between the two subcomponents is determined by the detailed potential landscape within the nanocrystals (NCs). One of the hallmarks of double QDs is the observation of dual-color emission from a single nanoparticle, which allows for detailed spectroscopy of their properties down to the single particle level. Furthermore, rational design of the two coupled subsystems enables one to tune the emission statistics from single photon

  8. 25 years Nuclear Research Centre

    Energy Technology Data Exchange (ETDEWEB)

    Harde, R.

    1981-07-01

    On June 12, the Karlsruhe Nuclear Research Centre celebrated its 25th anniversary. The Centre was founded on July 19, 1956. The importance of this institution became apparent by the large number of prominent guests, at the head, the Federal President, Karl Carstens. Minister President Spaeth and the Federal Minister for Research and Technology, von Buelow, appreciated the achievements obtained by this big science centre of nuclear technology. The ceremony held in the State theatre of Baden-Wuerttemberg gave testimony of an impressing confession in favour of nuclear energy. Excerpts from the speech of the Chairman of the Managing Board, Prof. Harde, are quoted.

  9. Minister unveils new nanotech centres

    Science.gov (United States)

    Dumé, Belle

    2009-06-01

    Three new nanotechnology research centres are to be set up in France as part of a €70m government plan to help French companies in the sector. Researchers at the new centres, which will be located in Grenoble, Saclay (near Paris) and Toulouse, will be encouraged to collaborate with industry to develop new nanotech-based products. Dubbed NANO-INNOV, the new plan includes €46m for two new buildings at Saclay, with the rest being used to buy new equipment at the three centres and to fund grant proposals from staff to the French National Research Agency (ANR).

  10. The World Heritage Centr

    Directory of Open Access Journals (Sweden)

    Ayman G. Abdel Tawab

    2014-09-01

    Full Text Available New Gourna Village, which is located inside one of the World Heritage Sites in Egypt, has never been recognized as an element contributing to the site’s Outstanding Universal Value. The recognition of the village as a contributing element is reliant on the successful assessment of its authenticity and integrity. Responding to the dramatically declining integrity of the village, the World Heritage Centre has carried out an architectural study to guide the potential conservation works in the property. The study has recommended that a group of objectives and two approaches to the conservation of the village should be adopted. One of these two approaches has been concerned with the conservation of the village according to the architect’s original intentions and principles. The previous approach can be called the principles-based approach. The main aim of this study was to examine the agreement of the World Heritage Centre’s objectives and their proposed principles-based approach to the conservation of the village with the aim to improve its chance in meeting the conditions of authenticity and integrity. The study approached the previous aim by assessing, by means of a proposed methodology; the level of significance, authenticity and integrity of the property. Based on the previous assessment, a list of conservation interventions was proposed to improve the property’s chance in meeting the conditions of authenticity and integrity. Finally, the World Heritage Centre’s recommended approaches and objectives were examined against the previous proposed conservation interventions. The findings indicated the possibility to adopt the principles-based approach to the conservation of New Gourna Village, as well as the other World Heritage Centre’s objectives, without limiting the property’s chance in meeting the conditions of authenticity and integrity. The study recommends to carry out further studies that are concerned with the identification

  11. Measurement of the B (s) (0) -> aEuro parts per thousand I center dot I center dot branching fraction and search for the decay B (0) -> phi phi

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M-O; van Beuzekom, M.; Bien, A.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Buchanan, E.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. Campora; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S-F; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Dean, C-T; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fohl, K.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Gandara, M. Grabalosa; Graciani Diaz, R.; Granado Cardoso, L. A.; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Latham, T.; Lazzeroni, C.

    2015-01-01

    Using a dataset corresponding to an integrated luminosity of 3.0 fb(-1) collected in pp collisions at centre-of-mass energies of 7 and 8 TeV, the B (s) (0) -> aEuro parts per thousand I center dot I center dot branching fraction is measured to be B(B-0 -> phi phi) = (1.84 +/- 0.05(stat) +/- 0.07 (sy

  12. The centre of the action

    CERN Document Server

    2008-01-01

    The CERN Control Centre (CCC) has all the ingredients of an action movie control room: hundreds of screens, technicians buzzing in and out, huge floor-to-ceiling windows revealing the looming vista of a mountain range, flashing lights, microphones… This is the place where not just the LHC, but the whole of CERN’s accelerator complex and technical support is based - truly the centre of the action at CERN.

  13. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Science.gov (United States)

    Alert, Bianca; Michalik, Andreas; Helduser, Sascha; Mouritsen, Henrik; Güntürkün, Onur

    2015-01-01

    Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  14. Perceptual strategies of pigeons to detect a rotational centre--a hint for star compass learning?

    Directory of Open Access Journals (Sweden)

    Bianca Alert

    Full Text Available Birds can rely on a variety of cues for orientation during migration and homing. Celestial rotation provides the key information for the development of a functioning star and/or sun compass. This celestial compass seems to be the primary reference for calibrating the other orientation systems including the magnetic compass. Thus, detection of the celestial rotational axis is crucial for bird orientation. Here, we use operant conditioning to demonstrate that homing pigeons can principally learn to detect a rotational centre in a rotating dot pattern and we examine their behavioural response strategies in a series of experiments. Initially, most pigeons applied a strategy based on local stimulus information such as movement characteristics of single dots. One pigeon seemed to immediately ignore eccentric stationary dots. After special training, all pigeons could shift their attention to more global cues, which implies that pigeons can learn the concept of a rotational axis. In our experiments, the ability to precisely locate the rotational centre was strongly dependent on the rotational velocity of the dot pattern and it crashed at velocities that were still much faster than natural celestial rotation. We therefore suggest that the axis of the very slow, natural, celestial rotation could be perceived by birds through the movement itself, but that a time-delayed pattern comparison should also be considered as a very likely alternative strategy.

  15. Nanocrystal quantum dots

    CERN Document Server

    Klimov, Victor I

    2010-01-01

    ""Soft"" Chemical Synthesis and Manipulation of Semiconductor Nanocrystals, J.A. Hollingsworth and V.I. Klimov Electronic Structure in Semiconductor Nanocrystals: Optical Experiment, D.J. NorrisFine Structure and Polarization Properties of Band-Edge Excitons in Semiconductor Nanocrystals, A.L. EfrosIntraband Spectroscopy and Dynamics of Colloidal Semiconductor Quantum Dots, P. Guyot-Sionnest, M. Shim, and C. WangMultiexciton Phenomena in Semiconductor Nanocrystals, V.I. KlimovOptical Dynamics in Single Semiconductor Quantum Do

  16. Quantum dot nanostructures

    Directory of Open Access Journals (Sweden)

    Mohamed Henini

    2002-06-01

    These sophisticated technologies for the growth of high quality epitaxial layers of compound semiconductor materials on single crystal semiconductor substrates are becoming increasingly important for the development of the semiconductor electronics industry. This article is intended to convey the flavor of the subject by focusing on the technology and applications of self-assembled quantum dots (QDs and to give an introduction to some of the essential characteristics.

  17. The ideal Atomic Centre; Le Centre Atomique ideal

    Energy Technology Data Exchange (ETDEWEB)

    Mas, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The author presents considerations which should prove to be of interest to all those who have to design, to construct and to operate a nuclear research centre. A large number of the ideas presented can also be applied to non-nuclear scientific research centres. In his report the author reviews: various problems with which the constructor is faced: ground-plan, infrastructure, buildings and the large units of scientific equipment in the centre, and those problems facing the director: maintenance, production, supplies, security. The author stresses the relationship which ought to exist between the research workers and the management. With this aim in view he proposes the creation of National School for Administration in Research which would train administrative executives for public or private organisations; they would be specialised in the fields of fundamental or applied research. (author) [French] L'auteur propose une base de reflexions a tous ceux qui doivent concevoir, realiser et faire vivre un Centre d'Etudes Nucleaires. Un grand nombre des idees exprimees peut d'ailleurs s'appliquer a un Centre d'Etudes Scientifiques non nucleaires. Dans son ouvrage, l'auteur passe en revue les differents problemes qui se posent au constructeur: plan, masse, infrastructure, batiments et grands appareils du Centre, et ceux qu'a a resoudre le directeur: entretien, fabrication, approvisionnements, securite. L'auteur insiste sur l'aspect des rapports qui doivent exister entre les chercheurs et ceux qui les administrent. Il propose a cette fin la creation d'une Ecole Nationale d'Administration de la Recherche qui formerait des cadres administratifs pour les organismes publics ou prives, specialises dans la Recherche fondamentale ou appliquee. (auteur)

  18. Inter-dot coupling effects on transport through correlated parallel coupled quantum dots

    Indian Academy of Sciences (India)

    Shyam Chand; G Rajput; K C Sharma; P K Ahluwalia

    2009-05-01

    Transport through symmetric parallel coupled quantum dot system has been studied, using non-equilibrium Green function formalism. The inter-dot tunnelling with on-dot and inter-dot Coulomb repulsion is included. The transmission coefficient and Landaur–Buttiker like current formula are shown in terms of internal states of quantum dots. The effect of inter-dot tunnelling on transport properties has been explored. Results, in intermediate inter-dot coupling regime show signatures of merger of two dots to form a single composite dot and in strong coupling regime the behaviour of the system resembles the two decoupled dots.

  19. 腹腔注射四氯化碳辅以饮食改良制备犬慢性肝纤维化模型%Induction of Liver Fibrosis and Cirrhosis in a New Canine Model by Using Intraperitoneal Injection of CCl4 Plus Diet Modification

    Institute of Scientific and Technical Information of China (English)

    章雅琴; 李丛蕊; 骆雷; 胡跃群; 容鹏飞; 王维

    2011-01-01

    探讨一种经典的、与人类慢性肝纤维化-肝硬化进程相似的大动物模型建立方法.采用15只成年健康中华田园犬:对照组5只,使用生理盐水腹腔注射及正常饲料干预;实验组10只,采用小剂量四氯化碳(CCl4)腹腔注射及高脂饮食干预.间断采血检测肝功能、血清学肝纤维化指标,B超引导下定期肝穿活检作HE染色和Masson染色.56周后所有实验动物成功诱导至不同程度的肝纤维化.丙氨酸氨基转移酶、门冬氨酸转氨酶、球蛋白、总胆红素、γ-谷氨酰基转肽酶以及透明质酸与对照组相比,差异均有统计学意义(P<0.05).联合应用小剂量CCl4和单纯高脂饮食可成功诱导犬慢性肝纤维化-肝硬化模型,该方法动物存活率和成模率均较高,可为后续的相关研究提供更好的平台.%To explore the procedures for creating a classic large animal model that mimics the chronic disease progress of hepatic fibrosis and cirrhosis in human subjects. Fifteen adult cross-bred dogs were divided into two groups: the normal control group (n=5) received intraperitoneal injection of normal saline and normal diet, and the experimental group (ra=10) were administered 50% CCLt in vegetable oil by intraperitoneal injection and high fat diet. Every 4 weeks after injection, blood samples in all animals were collected and analyzed to monitor the liver function and serum markers of liver fibrosis. Additionally, ultrasound-guided liver biopsy was performed for HE and Masson staining. Different degree of liver cirrhosis in subjects from the experimental group was successfully induced at the end of 56 week. The serum level of alanine amino-transferase (ALT), aspartate aminotransferase (AST), globulin (GLB), total bilirubin (TBIL), y-glutamyl trans-ferase (GGT) and hyaluronic acid (HA) in the experimental group were significantly increased relative to the control group (P<0.05). A chronic hepatic fibrosis and cirrhosis animal model

  20. Person-centred reflective practice.

    Science.gov (United States)

    Devenny, Bob; Duffy, Kathleen

    Person-centred health and person-centred care have gained prominence across the UK following the publication of reports on public inquiries exploring failings in care. Self-awareness and participation in reflective practice are recognised as vital to supporting the person-centred agenda. This article presents an education framework for reflective practice, developed and used in one NHS board in Scotland, and based on the tenets of the clinical pastoral education movement. Providing an insight into the usefulness of a spiritual component in the reflective process, the framework provides an opportunity for nurses and other healthcare professionals to examine the spiritual dimensions of patient encounters, their own values and beliefs, and the effect these may have on their practice.

  1. Construction of the Wigner Data Centre

    CERN Document Server

    2013-01-01

    A remote extension of the CERN data centre has recently been inaugurated. Hosted at the Wigner Research Centre for Physics in Hungary, it provides extra computing power required to cover CERN’s needs. This video presents the construction of the Wigner Data Centre from initial demolishing work through to its completion and details the major technical characteristics of the Data Centre.

  2. Single quantum dot nanowire photodetectors

    NARCIS (Netherlands)

    Van Kouwen, M.P.; Van Weert, M.H.M.; Reimer, M.E.; Akopian, N.; Perinetti, U.; Algra, R.E.; Bakkers, E.P.A.M.; Kouwenhoven, L.P.; Zwiller, V.

    2010-01-01

    We report InP nanowire photodetectors with a single InAsP quantum dot as light absorbing element. With excitation above the InP band gap, the nanowire photodetectors are efficient (quantum efficiency of 4%). Under resonant excitation of the quantum dot, the photocurrent amplitude depends on the line

  3. LDE centres: sprint or marathon?

    NARCIS (Netherlands)

    Bonger, S.; Van Rein, E.

    2015-01-01

    The aim of the Strategic Leiden-Delft-Erasmus Alliance, established by the three universities in 2012, was to improve research and education and competitiveness. Projects are intended to develop from the ground up, which led to the establishment of eight joint centres in 2013. A quick look around re

  4. Complex dynamics in planar two-electron quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Schroeter, Sebastian Josef Arthur

    2013-06-25

    Quantum dots play an important role in a wide range of recent experimental and technological developments. In particular they are promising candidates for realisations of quantum bits and further applications in quantum information theory. The harmonically confined Hooke's atom model is experimentally verified and separates in centre-of-mass and relative coordinates. Findings that are contradictory to this separability call for an extension of the model, in particular changing the confinement potential. In order to study effects of an anharmonic confinement potential on spectral properties of planar two-electron quantum dots a sophisticated numerical approach is developed. Comparison between the Helium atom, Hooke's atom and an anharmonic potential model are undertaken in order to improve the description of quantum dots. Classical and quantum features of complexity and chaos are investigated and used to characterise the dynamics of the system to be mixed regular-chaotic. Influence of decoherence can be described by quantum fidelity, which measures the effect of a perturbation on the time evolution. The quantum fidelity of eigenstates of the system depends strongly on the properties of the perturbation. Several methods for solving the time-dependent Schrödinger equation are implemented and a high level of accuracy for long time evolutions is achieved. The concept of offset entanglement, the entanglement of harmonic models in the noninteracting limit, is introduced. This concept explains different questions raised in the literature for harmonic quantum dot models, recently. It shows that only in the groundstate the electrons are not entangled in the fermionic sense. The applicability, validity, and origin of Hund's first rule in general quantum dot models is further addressed. In fact Hund's first rule is only applicable, and in this case also valid, for one pair of singlet and triplet states in Hooke's atom. For more realistic models of two

  5. The CCCB is a cultural centre, not a tourist centre

    Directory of Open Access Journals (Sweden)

    Elena Xirau

    2004-04-01

    Full Text Available Last February, Barcelona's Centre of Contemporary Culture (CCCB celebrated its first ten years in existence. During this time, this institution has looked to be a showcase to the most modern and innovative cultural expressions focused on reflecting on the concept of the city. In this interview, Josep Ramoneda offers his personal view, as the CCCB's director. He talks of how this cultural project was born, of how the concept of the institution took shape in the CCCB, of its relations with Barcelona's Strategic Plan, of how the project has evolved, of the architectural remodelling of the Casa de la Caritat building for its conversion into a cultural centre, of the relations with other institutions and its future.

  6. European Centre for Disease Prevention and Control.

    Science.gov (United States)

    Evans, Roger

    2014-11-04

    The European Centre for Disease Prevention and Control was set up in 2005 to strengthen Europe's defences against infectious diseases. The centre is an independent agency of the European Union and is based in Stockholm, Sweden.

  7. Quantum dots: Rethinking the electronics

    Science.gov (United States)

    Bishnoi, Dimple

    2016-05-01

    In this paper, we demonstrate theoretically that the Quantum dots are quite interesting for the electronics industry. Semiconductor quantum dots (QDs) are nanometer-scale crystals, which have unique photo physical, quantum electrical properties, size-dependent optical properties, There small size means that electrons do not have to travel as far as with larger particles, thus electronic devices can operate faster. Cheaper than modern commercial solar cells while making use of a wider variety of photon energies, including "waste heat" from the sun's energy. Quantum dots can be used in tandem cells, which are multi junction photovoltaic cells or in the intermediate band setup. PbSe (lead selenide) is commonly used in quantum dot solar cells.

  8. Hydrophobin-Encapsulated Quantum Dots.

    Science.gov (United States)

    Taniguchi, Shohei; Sandiford, Lydia; Cooper, Maggie; Rosca, Elena V; Ahmad Khanbeigi, Raha; Fairclough, Simon M; Thanou, Maya; Dailey, Lea Ann; Wohlleben, Wendel; von Vacano, Bernhard; de Rosales, Rafael T M; Dobson, Peter J; Owen, Dylan M; Green, Mark

    2016-02-01

    The phase transfer of quantum dots to water is an important aspect of preparing nanomaterials that are suitable for biological applications, and although numerous reports describe ligand exchange, very few describe efficient ligand encapsulation techniques. In this report, we not only report a new method of phase transferring quantum dots (QDs) using an amphiphilic protein (hydrophobin) but also describe the advantages of using a biological molecule with available functional groups and their use in imaging cancer cells in vivo and other imaging applications.

  9. Quantum Dots in Cell Biology

    OpenAIRE

    Barroso, Margarida M.

    2011-01-01

    Quantum dots are semiconductor nanocrystals that have broad excitation spectra, narrow emission spectra, tunable emission peaks, long fluorescence lifetimes, negligible photobleaching, and ability to be conjugated to proteins, making them excellent probes for bioimaging applications. Here the author reviews the advantages and disadvantages of using quantum dots in bioimaging applications, such as single-particle tracking and fluorescence resonance energy transfer, to study receptor-mediated t...

  10. Quantum dots in cell biology.

    Science.gov (United States)

    Barroso, Margarida M

    2011-03-01

    Quantum dots are semiconductor nanocrystals that have broad excitation spectra, narrow emission spectra, tunable emission peaks, long fluorescence lifetimes, negligible photobleaching, and ability to be conjugated to proteins, making them excellent probes for bioimaging applications. Here the author reviews the advantages and disadvantages of using quantum dots in bioimaging applications, such as single-particle tracking and fluorescence resonance energy transfer, to study receptor-mediated transport.

  11. Fuzzy dot ideals and fuzzy dot H-ideals of BCH-algebras

    Institute of Scientific and Technical Information of China (English)

    PENG Jia-yin

    2008-01-01

    The notions of fuzzy dot ideals and fuzzy dot H-ideals in BCH-algebras are intro duced,several appropriate examples are provided,and their some properties are investigated.The relations among fuzzy ideal,fuzzy H-ideal,fuzzy dot ideal and fuzzy dot H-ideals in BCH algebras are discussed,several equivalent depictions of fuzzy dot ideal are obtained. How to deal with the homomorphic image and inverse image of fuzzy dot ideals (fuzzy dot H-ideals) are studied. The relations between a fuzzy dot ideal (fuzzy dot H-ideal) in BCH-algebras and a fuzzy dot ideal (fuzzy dot H-ideal) in the product algebra of BCH-algebras are given.

  12. Scheduling participants of Assessment Centres

    DEFF Research Database (Denmark)

    Lysgaard, Jens; Løber, Janni

      Assessment Centres are used as a tool for psychologists and coaches to observe a number of dimensions in a person's behaviour and test his/her potential within a number of chosen focus areas. This is done in an intense course, with a number of different exercises which expose each participant......'s ability level in the chosen focus areas. The participants are observed by assessors with the purpose of gathering material for reaching a conclusion on each participant's personal profile. We consider the particular case that arises at the company Human Equity (www.humanequity.dk), where Assessment...

  13. InAs/GaAs submonolayer quantum dot superluminescent diode emitting around 970 nm

    Institute of Scientific and Technical Information of China (English)

    Li Xin-Kun; Liang De-Chun; Jin Peng; An Qi; Wei Heng; Wu Jian; Wang Zhan-Guo

    2012-01-01

    According to the InAs/GaAs submonolayer quantum dot active region,we demonstrate a bent-waveguide superlnminescent diode emitting at a wavelength of around 970 nm.At a pulsed injection current of 0.5 A,the device exhibits an output power of 24 mW and an emission spectrum centred at 971 nm with a full width at half maximum of 16 nm.

  14. Single to quadruple quantum dots with tunable tunnel couplings

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, T.; Noiri, A.; Obata, T.; Yoneda, J.; Yoshida, K. [Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Otsuka, T.; Tarucha, S. [Department of Applied Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); RIKEN, Center for Emergent Matter Science, 3-1 Wako-shi, Saitama 351-0198 (Japan)

    2014-03-17

    We prepare a gate-defined quadruple quantum dot to study the gate-tunability of single to quadruple quantum dots with finite inter-dot tunnel couplings. The measured charging energies of various double dots suggest that the dot size is governed by the gate geometry. For the triple and quadruple dots, we study the gate-tunable inter-dot tunnel couplings. For the triple dot, we find that the effective tunnel coupling between side dots significantly depends on the alignment of the center dot potential. These results imply that the present quadruple dot has a gate performance relevant for implementing spin-based four-qubits with controllable exchange couplings.

  15. Neighbourhood Centres – Organisation, Management and Finance

    DEFF Research Database (Denmark)

    Larsen, Jacob Norvig

    public subsidy. Some of the centres have high number of users on a daily basis, whereas others are only rarely used. It is explored how organisation, management and financial set-up differs among the centres. Quantitative data on financial issues and annual accounts of fifteen centres were analysed......From the late 1990s neighbourhood centres were brought to the fore of public urban regen-eration policy, because they were seen as a means to accelerate the formation of social capital in deprived urban neighbourhoods. A number of such local community centres were established with substantial...... to identify different financial models and analyse economic sustainability. As regards organisational and management models data were collected through documentary sources and by means of personal interviews and field visits to ten centres. Even within the analysed limited population of centres economic...

  16. Engineering colloidal quantum dot solids within and beyond the mobility-invariant regime

    KAUST Repository

    Zhitomirsky, David

    2014-05-06

    © 2014 Macmillan Publishers Limited. Colloidal quantum dots are attractive materials for efficient, low-cost and facile implementation of solution-processed optoelectronic devices. Despite impressive mobilities (1-30 cm2V-1 s-1) reported for new classes of quantum dot solids, it is-surprisingly-the much lower-mobility (10-3-10-2 cm2V-1 s-1) solids that have produced the best photovoltaic performance. Here we show that it is not mobility, but instead the average spacing among recombination centres that governs the diffusion length of charges in today\\'s quantum dot solids. In this regime, colloidal quantum dot films do not benefit from further improvements in charge carrier mobility. We develop a device model that accurately predicts the thickness dependence and diffusion length dependence of devices. Direct diffusion length measurements suggest the solid-state ligand exchange procedure as a potential origin of the detrimental recombination centres. We then present a novel avenue for in-solution passivation with tightly bound chlorothiols that retain passivation from solution to film, achieving an 8.5% power conversion efficiency.

  17. Perceptual centres in speech - an acoustic analysis

    Science.gov (United States)

    Scott, Sophie Kerttu

    Perceptual centres, or P-centres, represent the perceptual moments of occurrence of acoustic signals - the 'beat' of a sound. P-centres underlie the perception and production of rhythm in perceptually regular speech sequences. P-centres have been modelled both in speech and non speech (music) domains. The three aims of this thesis were toatest out current P-centre models to determine which best accounted for the experimental data bto identify a candidate parameter to map P-centres onto (a local approach) as opposed to the previous global models which rely upon the whole signal to determine the P-centre the final aim was to develop a model of P-centre location which could be applied to speech and non speech signals. The first aim was investigated by a series of experiments in which a) speech from different speakers was investigated to determine whether different models could account for variation between speakers b) whether rendering the amplitude time plot of a speech signal affects the P-centre of the signal c) whether increasing the amplitude at the offset of a speech signal alters P-centres in the production and perception of speech. The second aim was carried out by a) manipulating the rise time of different speech signals to determine whether the P-centre was affected, and whether the type of speech sound ramped affected the P-centre shift b) manipulating the rise time and decay time of a synthetic vowel to determine whether the onset alteration was had more affect on P-centre than the offset manipulation c) and whether the duration of a vowel affected the P-centre, if other attributes (amplitude, spectral contents) were held constant. The third aim - modelling P-centres - was based on these results. The Frequency dependent Amplitude Increase Model of P-centre location (FAIM) was developed using a modelling protocol, the APU GammaTone Filterbank and the speech from different speakers. The P-centres of the stimuli corpus were highly predicted by attributes of

  18. The new AMS control centre

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    Construction work for the future AMS control room began in November 2010 and should be finished this June. The new building, which will have been completed in record time thanks to the professionalism of the project team, will soon be ready to receive the initial data from the AMS experiment.     Luigi Scibile and Michael Poehler, from the GS department, at the AMS control centre construction site.   The Alpha Magnetic Spectrometer (AMS) is due to wing its way towards the International Space Station (ISS) on board the shuttle Discovery in April. Mainly intended for research on antimatter and dark matter, the data collected by AMS will be sent to Houston in the United States and then directly to CERN’s new Building 946. Construction work for the AMS control centre building on the Route Gentner at CERN’s Prévessin site started in November 2010 and must be completed in time to receive the first data from the spectrometer in June. “It normall...

  19. Optically active quantum dots

    Science.gov (United States)

    Gerard, Valerie; Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii K.

    2015-10-01

    The main goal of our research is to develop new types of technologically important optically active quantum dot (QD) based materials, study their properties and explore their biological applications. For the first time chiral II-VI QDs have been prepared by us using microwave induced heating with the racemic (Rac), D- and L-enantiomeric forms of penicillamine as stabilisers. Circular dichroism (CD) studies of these QDs have shown that D- and L-penicillamine stabilised particles produced mirror image CD spectra, while the particles prepared with a Rac mixture showed only a weak signal. It was also demonstrated that these QDs show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. These QDs have demonstrated highly specific chiral recognition of various biological species including aminoacids. The utilisation of chiral stabilisers also allowed the preparation of new water soluble white emitting CdS nano-tetrapods, which demonstrated circular dichroism in the band-edge region of the spectrum. Biological testing of chiral CdS nanotetrapods displayed a chiral bias for an uptake of the D- penicillamine stabilised nano-tetrapods by cancer cells. It is expected that this research will open new horizons in the chemistry of chiral nanomaterials and their application in nanobiotechnology, medicine and optical chemo- and bio-sensing.

  20. Fossil Dot Com

    DEFF Research Database (Denmark)

    2011-01-01

    technological examples from his background as director of the innovation centre at DONG Energy, Charles Nielsen will discuss the impact of upcoming changes to the backbone of industry: the energy supply. DONG Energy has an ambitious strategy of changing the energy supply from 15% to 85% renewable energy before...... 2040. Embodiment of the corporate strategy into designs including urban design, bio refineries, offshore wind, sun and electric vehicles will serve as a platform for describing design challenges of the future - A future where society at large becomes the most important stakeholder demanding sustenance....... Management gurus have taught us for the last 20 years that in the end we all are delivering products and services to end users. This may still hold true; however, we now need to learn that we all are nothing but subsidiary companies of the nature....

  1. Powering the Future Data Centre

    DEFF Research Database (Denmark)

    Zhang, Zhe

    2010-01-01

    . Considering the input impendence of fuel cell and super-cap, the small-signal stability of cascaded converter is analyzed. The system small-signal model is rebuilt and controllers for current loop and voltage loop are designed to obtain good transient performance. Through analysis and synthesis......The extended run Uninterruptible Power Supply system (UPSs) which powered by fuel cells and supercapcitors, is a promising solution for future data centre to obtain environmentfriendly energy efficient and cost effective. There are many challenges in power electronic interface circuits, because...... of the characteristics of these two power sources: long warm-up stage and low dynamics for fuel cell, and variable terminal voltage for supercapacitors. The motivation for this project was to find ways which can overcome those limitations to integrate fuel cells and supercapcitors to the system with high efficiency...

  2. Self-assembled quantum dots in a nanowire system for quantum photonics.

    Science.gov (United States)

    Heiss, M; Fontana, Y; Gustafsson, A; Wüst, G; Magen, C; O'Regan, D D; Luo, J W; Ketterer, B; Conesa-Boj, S; Kuhlmann, A V; Houel, J; Russo-Averchi, E; Morante, J R; Cantoni, M; Marzari, N; Arbiol, J; Zunger, A; Warburton, R J; Fontcuberta i Morral, A

    2013-05-01

    Quantum dots embedded within nanowires represent one of the most promising technologies for applications in quantum photonics. Whereas the top-down fabrication of such structures remains a technological challenge, their bottom-up fabrication through self-assembly is a potentially more powerful strategy. However, present approaches often yield quantum dots with large optical linewidths, making reproducibility of their physical properties difficult. We present a versatile quantum-dot-in-nanowire system that reproducibly self-assembles in core-shell GaAs/AlGaAs nanowires. The quantum dots form at the apex of a GaAs/AlGaAs interface, are highly stable, and can be positioned with nanometre precision relative to the nanowire centre. Unusually, their emission is blue-shifted relative to the lowest energy continuum states of the GaAs core. Large-scale electronic structure calculations show that the origin of the optical transitions lies in quantum confinement due to Al-rich barriers. By emitting in the red and self-assembling on silicon substrates, these quantum dots could therefore become building blocks for solid-state lighting devices and third-generation solar cells.

  3. Chiral Graphene Quantum Dots.

    Science.gov (United States)

    Suzuki, Nozomu; Wang, Yichun; Elvati, Paolo; Qu, Zhi-Bei; Kim, Kyoungwon; Jiang, Shuang; Baumeister, Elizabeth; Lee, Jaewook; Yeom, Bongjun; Bahng, Joong Hwan; Lee, Jaebeom; Violi, Angela; Kotov, Nicholas A

    2016-02-23

    Chiral nanostructures from metals and semiconductors attract wide interest as components for polarization-enabled optoelectronic devices. Similarly to other fields of nanotechnology, graphene-based materials can greatly enrich physical and chemical phenomena associated with optical and electronic properties of chiral nanostructures and facilitate their applications in biology as well as other areas. Here, we report that covalent attachment of l/d-cysteine moieties to the edges of graphene quantum dots (GQDs) leads to their helical buckling due to chiral interactions at the "crowded" edges. Circular dichroism (CD) spectra of the GQDs revealed bands at ca. 210-220 and 250-265 nm that changed their signs for different chirality of the cysteine edge ligands. The high-energy chiroptical peaks at 210-220 nm correspond to the hybridized molecular orbitals involving the chiral center of amino acids and atoms of graphene edges. Diverse experimental and modeling data, including density functional theory calculations of CD spectra with probabilistic distribution of GQD isomers, indicate that the band at 250-265 nm originates from the three-dimensional twisting of the graphene sheet and can be attributed to the chiral excitonic transitions. The positive and negative low-energy CD bands correspond to the left and right helicity of GQDs, respectively. Exposure of liver HepG2 cells to L/D-GQDs reveals their general biocompatibility and a noticeable difference in the toxicity of the stereoisomers. Molecular dynamics simulations demonstrated that d-GQDs have a stronger tendency to accumulate within the cellular membrane than L-GQDs. Emergence of nanoscale chirality in GQDs decorated with biomolecules is expected to be a general stereochemical phenomenon for flexible sheets of nanomaterials.

  4. Quantum-dot emitters in photonic nanostructures

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Stobbe, Søren; Lodahl, Peter

    2010-01-01

    The spontaneous emission from self-assembled semiconductor quantum dots is strongly influenced by the environment in which they are placed. This can be used to determine fundamental optical properties of the quantum dots as well as to manipulate and control the quantum-dot emission itself....

  5. Beer's law in semiconductor quantum dots

    CERN Document Server

    Adamashvili, G T

    2010-01-01

    The propagation of a coherent optical linear wave in an ensemble of semiconductor quantum dots is considered. It is shown that a distribution of transition dipole moments of the quantum dots changes significantly the polarization and Beer's absorption length of the ensemble of quantum dots. Explicit analytical expressions for these quantities are presented.

  6. Membrane analysis with amphiphilic carbon dots.

    Science.gov (United States)

    Nandi, Sukhendu; Malishev, Ravit; Parambath Kootery, Kaviya; Mirsky, Yelena; Kolusheva, Sofiya; Jelinek, Raz

    2014-09-14

    Newly-synthesized amphiphilic carbon dots were used for spectroscopic analysis and multicolour microscopic imaging of membranes and live cells. We show that Förster resonance energy transfer (FRET) occurred from the amphiphilic carbon dots to different membrane-associated fluorescence acceptors. The amphiphilic carbon dots enabled imaging of membrane disruption by the beta-amyloid peptide.

  7. Criteria of Categorizing Logistics and Distribution Centres

    OpenAIRE

    Darko Babić; Anđelko Šćukanec; Kristijan Rogic

    2011-01-01

    Logistics and distribution centres represent very significant infrastructure elements of the macro-logistic system. The creation of the logistics and distribution centres and their connection into a wide (global) network have resulted in the creation of conditions for an adequate distribution of labour and significant increase in the productivity of all the logistics elements and processes, noting that the logistics and distribution centres in this concept have a superregional significance. ...

  8. Smart work centres in rural areas

    DEFF Research Database (Denmark)

    Lorentzen, Anne Birte

    This paper discusses the establishment of telework centres as an element in local development strategies in rural areas, with a particular view to two new telework centres in region North Denmark. The paper argues that telework centres do not represent an easy solution to problems of local develo...... development and environmental sustainability, and further, that technology may not even be the most important feature needed to make them function as such....

  9. Activities of Radiation Protection Centre in 2000

    CERN Document Server

    Radiat. Prot. Cent. Vilnius

    2001-01-01

    Description of the activities of Radiation Protection Centre in 2000 is presented. Radiation Protection Centre is responsible for radiation protection issues. Currently there are six departments at Radiation Protection Centre: two in Vilnius - Department of Radiation Protection Supervision and Control and Department of Programs and Expertise, and four in the districts. Brief information on subject controlled by each departments is provided focusing on main achievements and events.

  10. Criteria of Categorizing Logistics and Distribution Centres

    Directory of Open Access Journals (Sweden)

    Darko Babić

    2011-07-01

    Full Text Available Logistics and distribution centres represent very significant infrastructure elements of the macro-logistic system. The creation of the logistics and distribution centres and their connection into a wide (global network have resulted in the creation of conditions for an adequate distribution of labour and significant increase in the productivity of all the logistics elements and processes, noting that the logistics and distribution centres in this concept have a superregional significance. This paper represents the summary (results of the research that was carried out on a large number of logistics and distribution centres with the aim of considering the complexity and the issues related to the logistics and distribution centres and the distribution network, their elements and action of the subsystems according to the following criteria: spatial, technical, technological, and organizational, with the aim of defining the categorisation model of the logistics and distribution centres. The analysis of the selected data collected during the research has resulted in defining of the categorisation model of the logistics and distribution centres which foresees six categories. Each of the foreseen categories has been defined according to the set model by the mentioned traffic, technical and technological, and organisational characteristics and the level of service. This is precisely where the application of the categorisation model of the logistics and distribution centres can be found, which will define the relevant categories of the centres applicable in the creation of effective distribution

  11. Nanoscale quantum-dot supercrystals

    Science.gov (United States)

    Baimuratov, Anvar S.; Turkov, Vadim K.; Rukhlenko, Ivan D.; Baranov, Alexander V.; Fedorov, Anatoly V.

    2013-09-01

    We develop a theory allowing one to calculate the energy spectra and wave functions of collective excitations in twoand three-dimensional quantum-dot supercrystals. We derive analytical expressions for the energy spectra of twodimensional supercrystals with different Bravias lattices, and use them to analyze the possibility of engineering the supercrystals' band structure. We demonstrate that the variation of the supercrystal's parameters (such as the symmetry of the periodic lattice and the properties of the quantum dots or their environment) enables an unprecedented control over its optical properties, thus paving a way towards the development of new nanophotonics materials.

  12. Spin storage in quantum dot ensembles and single quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Heiss, Dominik

    2009-10-15

    This thesis deals with the investigation of spin relaxation of electrons and holes in small ensembles of self-assembled quantum dots using optical techniques. Furthermore, a method to detect the spin orientation in a single quantum dot was developed in the framework of this thesis. A spin storage device was used to optically generate oriented electron spins in small frequency selected quantum dot ensembles using circularly polarized optical excitation. The spin orientation can be determined by the polarization of the time delayed electroluminescence signal generated by the device after a continuously variable storage time. The degree of spin polarized initialization was found to be limited to 0.6 at high magnetic fields, where anisotropic effects are compensated. The spin relaxation was directly measured as a function of magnetic field, lattice temperature and s-shell transition energy of the quantum dot by varying the spin storage time up to 30 ms. Very long spin lifetimes are obtained with a lower limit of T{sub 1}=20 ms at B=4 T and T=1 K. A strong magnetic field dependence T{sub 1}{proportional_to}B{sup -5} has been observed for low temperatures of T=1 K which weakens as the temperature is increased. In addition, the temperature dependence has been determined with T{sub 1}{proportional_to}T{sup -1}. The characteristic dependencies on magnetic field and temperature lead to the identification of the spin relaxation mechanism, which is governed by spin-orbit coupling and mediated by single phonon scattering. This finding is qualitatively supported by the energy dependent measurements. The investigations were extended to a modified device design that enabled studying the spin relaxation dynamics of heavy holes in self-assembled quantum dots. The measurements show a polarization memory effect for holes with up to 0.1 degree of polarization. Furthermore, investigations of the time dynamics of the hole spin relaxation reveal surprisingly long lifetimes T{sub 1}{sup h

  13. Laparoscopic adrenalectomy: Single centre experience.

    LENUS (Irish Health Repository)

    O'Farrell, N J

    2012-02-01

    BACKGROUND: Laparoscopic adrenalectomy is an attractive alternative to the traditional open approach in the surgical excision of an adrenal gland. It has replaced open adrenalectomy in our institution and we review our experience to date. METHODS: All cases of laparoscopic adrenalectomies in our hospital over eight years (from 2001 to May 2009) were retrospectively reviewed. Patient demographics, diagnosis, length of hospital stay, histology and all operative and post-operative details were evaluated. RESULTS: Fifty-five laparoscopic adrenalectomies (LA) were performed on 51 patients over eight years. The mean age was 48 years (Range 16-86 years) with the male: female ratio 1:2. Twenty-three cases had a right adrenalectomy, 24 had a left adrenalectomy and the remaining four patients had bilateral adrenalectomies. 91% were successfully completed laparoscopically with five converted to an open approach. Adenomas (functional and non functional) were the leading indication for LA, followed by phaeochromocytomas. Other indications for LA included Cushing\\'s disease, adrenal malignancies and rarer pathologies. There was one mortality from necrotising pancreatitis following a left adrenalectomy for severe Cushing\\'s disease, with subsequent death 10 days later. CONCLUSION: Laparoscopic adrenalectomy is effective for the treatment of adrenal tumours, fulfilling the criteria for the ideal minimally invasive procedure. It has replaced the traditional open approach in our centre and is a safe and effective alternative. However, in the case of severe Cushing\\'s disease, laparoscopic adrenalectomy has the potential for significant adverse outcomes and mortality.

  14. Polymer-coated quantum dots

    NARCIS (Netherlands)

    Tomczak, Nikodem; Liu, Rongrong; Vancso, Julius G.

    2013-01-01

    Quantum Dots (QDs) are semiconductor nanocrystals with distinct photophysical properties finding applications in biology, biosensing, and optoelectronics. Polymeric coatings of QDs are used primarily to provide long-term colloidal stability to QDs dispersed in solutions and also as a source of addit

  15. DOT strategies versus orbiter strategies

    NARCIS (Netherlands)

    Rutten, R.J.

    2001-01-01

    The Dutch Open Telescope is a high-resolution solar imager coming on-line at La Palma. The definition of the DOT science niche, strategies, and requirements resemble Solar Orbiter considerations and deliberations. I discuss the latter in the light of the former, and claim that multi-line observation

  16. Nuclear Spins in Quantum Dots

    NARCIS (Netherlands)

    Erlingsson, S.I.

    2003-01-01

    The main theme of this thesis is the hyperfine interaction between the many lattice nuclear spins and electron spins localized in GaAs quantum dots. This interaction is an intrinsic property of the material. Despite the fact that this interaction is rather weak, it can, as shown in this thesis, stro

  17. Luminescent Surface Quaternized Carbon Dots

    KAUST Repository

    Bourlinos, Athanasios B.

    2012-01-10

    Thermal oxidation of a salt precursor made from the acid base combination of tris(hydroxymethyl)aminomethane and betaine hydrochloride results in light-emitting surface quaternized carbon dots that are water-dispersible, display anion exchange properties, and exhibit uniform size/surface charge. © 2011 American Chemical Society.

  18. Danish Anaesthesia Allergy Centre - preliminary results

    DEFF Research Database (Denmark)

    Garvey, L H; Roed-Petersen, J; Menné, T

    2001-01-01

    BACKGROUND: Anaphylactoid reactions in anaesthesia are rare and should ideally be investigated in specialist centres. At Gentofte University Hospital, we established such a centre in 1998 as a joint venture between the Departments of Anaesthesiology and Dermatology. We present the methodology, di...

  19. Oil Trading Centre to Reopen in Shanghai

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Chinese oil companies will likely resume activities at the oil trading centre in Shanghai this year, a move to further liberalize the once tightly controlled oil market. The centre will trade forward contracts for refined oil products,including gasoline, diesel oil, kerosene and fuel oil, industrial sources said.

  20. The Press Research Centre, 1956-1976.

    Science.gov (United States)

    Press Research Centre, Krakow (Poland).

    In 1956, the Press Research Centre was established in Cracow, Poland by a group of journalists and publishers, for the purpose of instituting press research that would have practical applications. The aims of the Centre were to conduct studies on the history of the Polish press, the contemporary press, press readership, and editorial techniques.…

  1. The role of the sexual assault centre.

    LENUS (Irish Health Repository)

    Eogan, Maeve

    2013-02-01

    Sexual Assault Centres provide multidisciplinary care for men and women who have experienced sexual crime. These centres enable provision of medical, forensic, psychological support and follow-up care, even if patients chose not to report the incident to the police service. Sexual Support Centres need to provide a ring-fenced, forensically clean environment. They need to be appropriately staffed and available 24 hours a day, 7 days a week to allow prompt provision of medical and supportive care and collection of forensic evidence. Sexual Assault Centres work best within the context of a core agreed model of care, which includes defined multi-agency guidelines and care pathways, close links with forensic science and police services, and designated and sustainable funding arrangements. Additionally, Sexual Assault Centres also participate in patient, staff and community education and risk reduction. Furthermore, they contribute to the development, evaluation and implementation of national strategies on domestic, sexual and gender-based violence.

  2. Spin transport through quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Lima, A.T. da Cunha; Anda, Enrique V. [Pontificia Univ. Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil)

    2003-07-01

    Full text: We investigate the spin polarized transport properties of a nanoscopic device constituted by a quantum dot connected to two leads. The electrical current circulates with a spin polarization that is modulated via a gate potential that controls the intensity of the spin-orbit coupling, the Rashba effect. We study a polarized field-effect transistor when one of its parts is constituted by a small quantum dot, which energies are controlled by another gate potential operating inside the confined region. The high confinement and correlation suffered by the charges inside the dot gives rise to novel phenomena. We show that through the manipulation of the gate potential applied to the dot it is possible to control, in a very efficient way, the intensity and polarization of the current that goes along the system. Other crucial parameters to be varied in order to understand the behavior of this system are the intensity of the external applied electric and magnetic field. The system is represented by the Anderson Impurity Hamiltonian summed to a spin-orbit interaction, which describes the Rashba effect. To obtain the current of this out-of-equilibrium system we use the Keldysh formalism.The solution of the Green function are compatible with the Coulomb blockade regime. We show that under the effect of a external magnetic field, if the dot is small enough the device operates as a complete spin filter that can be controlled by the gate potential. The behavior of this device when it is injected into it a polarized current and modulated by the Rashba effect is as well studied. (author)

  3. Big Surveys, Big Data Centres

    Science.gov (United States)

    Schade, D.

    2016-06-01

    Well-designed astronomical surveys are powerful and have consistently been keystones of scientific progress. The Byurakan Surveys using a Schmidt telescope with an objective prism produced a list of about 3000 UV-excess Markarian galaxies but these objects have stimulated an enormous amount of further study and appear in over 16,000 publications. The CFHT Legacy Surveys used a wide-field imager to cover thousands of square degrees and those surveys are mentioned in over 1100 publications since 2002. Both ground and space-based astronomy have been increasing their investments in survey work. Survey instrumentation strives toward fair samples and large sky coverage and therefore strives to produce massive datasets. Thus we are faced with the "big data" problem in astronomy. Survey datasets require specialized approaches to data management. Big data places additional challenging requirements for data management. If the term "big data" is defined as data collections that are too large to move then there are profound implications for the infrastructure that supports big data science. The current model of data centres is obsolete. In the era of big data the central problem is how to create architectures that effectively manage the relationship between data collections, networks, processing capabilities, and software, given the science requirements of the projects that need to be executed. A stand alone data silo cannot support big data science. I'll describe the current efforts of the Canadian community to deal with this situation and our successes and failures. I'll talk about how we are planning in the next decade to try to create a workable and adaptable solution to support big data science.

  4. Carbon dots as antioxidants and prooxidants.

    Science.gov (United States)

    Christensen, Ingeborg Lie; Sun, Ya-Ping; Juzenas, Petras

    2011-10-01

    In this study we report the effect of classical CdSe/ZnS quantum dots and novel spherical carbon dots on generation of singlet oxygen and other reactive oxygen species (ROS) in aqueous solutions in vitro. Free radicals were initiated either chemically using 2,2'-azodiisobutyramidine dihydrochloride (AAPH) or by radiation with a blue light source emitting 390-470 nm (peak 420 nm). Two reagents, dihydrorhodamine 123 (Dhr123) and singlet oxygen sensor green (SOSG), were used as radical probes. Quantum dots and carbon dots inhibited oxidation of the radical probes under decomposition of AAPH. However, when subjected to the blue light both the quantum dots and carbon dots induced oxidation of Dhr123 to a greater extent than SOSG in water. Generation of singlet oxygen was remarkably enhanced in deuterium oxide solutions while oxidation of Dhr123 remained unchanged. For comparison, traditional photosensitizer protoporphyrin IX mainly induced oxidation of SOSG in water. In conclusion, upon external radiation carbon dots or quantum dots generate reactive oxygen species acting as prooxidants. Carbon dots or quantum dots also scavenge free radicals that are generated chemically by an azo compound. Such dual properties of these nanoparticles can be used for photodynamic and photocatalytic or antioxidant applications.

  5. Probing silicon quantum dots by single-dot techniques

    Science.gov (United States)

    Sychugov, Ilya; Valenta, Jan; Linnros, Jan

    2017-02-01

    Silicon nanocrystals represent an important class of non-toxic, heavy-metal free quantum dots, where the high natural abundance of silicon is an additional advantage. Successful development in mass-fabrication, starting from porous silicon to recent advances in chemical and plasma synthesis, opens up new possibilities for applications in optoelectronics, bio-imaging, photovoltaics, and sensitizing areas. In this review basic physical properties of silicon nanocrystals revealed by photoluminescence spectroscopy, lifetime, intensity trace and electrical measurements on individual nanoparticles are summarized. The fabrication methods developed for accessing single Si nanocrystals are also reviewed. It is concluded that silicon nanocrystals share many of the properties of direct bandgap nanocrystals exhibiting sharp emission lines at low temperatures, on/off blinking, spectral diffusion etc. An analysis of reported results is provided in comparison with theory and with direct bandgap material quantum dots. In addition, the role of passivation and inherent interface/matrix defects is discussed.

  6. Holistic design : learning from the Learning Centre

    Energy Technology Data Exchange (ETDEWEB)

    Simon, C. [Charles Simon Architect and Planner, Eden Mills, ON, (Canada); McKee, C. [Kitchener-Waterloo YMCA Outdoor Services, ON (Canada)

    2004-08-01

    The energy efficiency of several solar technologies currently in operation at the Kitchener-Waterloo YMCA's Environmental Learning Centre was evaluated. The off-grid earth-sheltered building dug into a south-facing slope features a sod roof, and protection from north winds by coniferous tree plantations. Passive solar strategies are evaluated, including average indoor temperatures and lighting requirements in both summer and winter. Also evaluated were the centre's ventilation systems, windows and passive heat recovery ventilators (HRVs), solar collectors, masonry heaters, and photovoltaic panels. The centre's composting toilets and use of the Living Machine{sup TM} were also discussed and details of the centre's building materials were provided. Ten straw-bale cabins are currently under construction at the centre, using passive solar strategies for heating, ventilation and cooling and combination propane fired/solar hot water heaters, straw bale building envelope and wood frame roof. Further suggestions for the centre's potential uses, and an outline of the centre's ongoing priorities were outlined. 4 refs.

  7. Near-infrared quantum dots for HER2 localization and imaging of cancer cells

    Directory of Open Access Journals (Sweden)

    Rizvi SB

    2014-03-01

    Full Text Available Sarwat B Rizvi,1 Sepideh Rouhi,1 Shohei Taniguchi,2 Shi Yu Yang,1 Mark Green,2 Mo Keshtgar,1,3 Alexander M Seifalian1,3 1UCL Centre for Nanotechnology and Regenerative Medicine, University College London, 2Department of Physics, King's College London, 3Royal Free London NHS Foundation Trust Hospital, London, UK Background: Quantum dots are fluorescent nanoparticles with unique photophysical properties that allow them to be used as diagnostic, therapeutic, and theranostic agents, particularly in medical and surgical oncology. Near-infrared-emitting quantum dots can be visualized in deep tissues because the biological window is transparent to these wavelengths. Their small sizes and free surface reactive groups that can be conjugated to biomolecules make them ideal probes for in vivo cancer localization, targeted chemotherapy, and image-guided cancer surgery. The human epidermal growth factor receptor 2 gene (HER2/neu is overexpressed in 25%–30% of breast cancers. The current methods of detection for HER2 status, including immunohistochemistry and fluorescence in situ hybridization, are used ex vivo and cannot be used in vivo. In this paper, we demonstrate the application of near-infrared-emitting quantum dots for HER2 localization in fixed and live cancer cells as a first step prior to their in vivo application. Methods: Near-infrared-emitting quantum dots were characterized and their in vitro toxicity was established using three cancer cell lines, ie, HepG2, SK-BR-3 (HER2-overexpressing, and MCF7 (HER2-underexpressing. Mouse antihuman anti-HER2 monoclonal antibody was conjugated to the near-infrared-emitting quantum dots. Results: In vitro toxicity studies showed biocompatibility of SK-BR-3 and MCF7 cell lines with near-infrared-emitting quantum dots at a concentration of 60 µg/mL after one hour and 24 hours of exposure. Near-infrared-emitting quantum dot antiHER2-antibody bioconjugates successfully localized HER2 receptors on SK-BR-3 cells

  8. Review of CERN Data Centre Infrastructure

    CERN Document Server

    Andrade, P; van Eldik, J; McCance, G; Panzer-Steindel, B; Coelho dos Santos, M; Traylen, S; Schwickerath, U

    2012-01-01

    The CERN Data Centre is reviewing strategies for optimizing the use of the existing infrastructure and expanding to a new data centre by studying how other large sites are being operated. Over the past six months, CERN has been investigating modern and widely-used tools and procedures used for virtualisation, clouds and fabric management in order to reduce operational effort, increase agility and support unattended remote data centres. This paper gives the details on the project’s motivations, current status and areas for future investigation.

  9. Modelling total energy costs of sports centres

    Energy Technology Data Exchange (ETDEWEB)

    Boussabaine, A.H.; Kirkham, R.J.; Grew, R.J. [Liverpool Univ., School of Architecture and Building Engineering, Liverpool (United Kingdom)

    1999-12-07

    Providing and maintaining safe and comfortable conditions in sport centres raises many issues, particularly cost. The paper gives an overview of the factors associated with sport centre servicing and attempts to highlight the governing factors associated with this, particularly energy costs. A total of 19 sport centres in the City of Liverpool in the UK are investigated, using data elicited from the Liverpool Leisure Services Directorate. The energy operating costs were analysed using statistical methods. Six models were developed to predict total energy costs. Testing and validation results showed a high level of model accuracy. The models would be of use to professionals involved in feasibility studies at the design stage. (Author)

  10. Potential of Natural Ventilation in Shopping Centres

    DEFF Research Database (Denmark)

    Diederichsen, Alice; Friis, Kristina; Brohus, Henrik;

    2008-01-01

    The indoor environmental quality (IEQ) is a fundamental requirement for a well performing shopping centre. This paper contains a pilot study of the potential of using hybrid ventilation (a combination of automatically controlled natural and mechanical ventilation - respectively NV and MV......) in shopping centres with focus on both the achieved IEQ and energy consumptions for air movement. By thermal building simulations it is found that there exists an interesting potential for hybrid ventilation of shopping centres, which can lead to great savings in the electrical energy consumptions...... for ventilation and cooling without compromising IEQ....

  11. New centre for intelligent mining systems

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, W.

    2002-10-01

    A Centre for Intelligent Mining Systems has been opened by the University of Alberta's Computing Science Department, a collaborative effort by the University and Syncrude Canada Ltd. The objective of the new Centre is to apply technologies in the area of artificial intelligence and robotics to the problems of surface mining. The Centre has already attracted attention from other players within the industry and a long-term funding proposal by a consortium that includes Syncrude is in the works. Noranda Inc and Inco Inc have also shown interest.

  12. Planetary Radars Operating Centre PROC

    Science.gov (United States)

    Catallo, C.; Flamini, E.; Seu, R.; Alberti, G.

    2007-12-01

    Planetary exploration by means of radar systems, mainly using Ground Penetrating Radars (GPR) plays an important role in Italy. Numerous scientific international space programs are currently carried out jointly with ESA and NASA by Italian Space Agency, the scientific community and the industry. Three important experiments under Italian leadership ( designed and manufactured by the Italian industry), provided by ASI either as contribution to ESA programs either within a NASA/ASI joint venture framework, are now operating: MARSIS on-board Mars Express, SHARAD on-board Mars Reconnaissance Orbiter and CASSINI Radar on-board Cassini spacecraft. In order to support all the scientific communities, institutional customers and experiment teams operation three Italian dedicated operational centers have been realized, namely SHOC, (Sharad Operating Centre), MOC (Marsis Operating Center) and CASSINI PAD ( Processing Altimetry Data). Each center is dedicated to a single instrument management and control, data processing and distribution. Although they had been conceived to operate autonomously and independently one from each other, synergies and overlaps have been envisaged leading to the suggestion of a unified center, the Planetary Radar Processing Center (PROC). PROC is conceived in order to include the three operational centers, namely SHOC, MOC and CASSINI PAD, either from logistics point of view and from HW/SW capabilities point of view. The Planetary Radar Processing Center shall be conceived as the Italian support facility to the scientific community for on-going and future Italian planetary exploration programs. Therefore, scalability, easy use and management shall be the design drivers. The paper describes how PROC is designed and developed, to allow SHOC, MOC and CASSINI PAD to operate as before, and to offer improved functionalities to increase capabilities, mainly in terms of data exchange, comparison, interpretation and exploitation. Furthermore, in the frame of

  13. Dot-in-Well Quantum-Dot Infrared Photodetectors

    Science.gov (United States)

    Gunapala, Sarath; Bandara, Sumith; Ting, David; Hill, cory; Liu, John; Mumolo, Jason; Chang, Yia Chung

    2008-01-01

    Dot-in-well (DWELL) quantum-dot infrared photodetectors (QDIPs) [DWELL-QDIPs] are subjects of research as potentially superior alternatives to prior QDIPs. Heretofore, there has not existed a reliable method for fabricating quantum dots (QDs) having precise, repeatable dimensions. This lack has constituted an obstacle to the development of uniform, high-performance, wavelength-tailorable QDIPs and of focal-plane arrays (FPAs) of such QDIPs. However, techniques for fabricating quantum-well infrared photodetectors (QWIPs) having multiple-quantum- well (MQW) structures are now well established. In the present research on DWELL-QDIPs, the arts of fabrication of QDs and QWIPs are combined with a view toward overcoming the deficiencies of prior QDIPs. The longer-term goal is to develop focal-plane arrays of radiationhard, highly uniform arrays of QDIPs that would exhibit high performance at wavelengths from 8 to 15 m when operated at temperatures between 150 and 200 K. Increasing quantum efficiency is the key to the development of competitive QDIP-based FPAs. Quantum efficiency can be increased by increasing the density of QDs and by enhancing infrared absorption in QD-containing material. QDIPs demonstrated thus far have consisted, variously, of InAs islands on GaAs or InAs islands in InGaAs/GaAs wells. These QDIPs have exhibited low quantum efficiencies because the numbers of QD layers (and, hence, the areal densities of QDs) have been small typically five layers in each QDIP. The number of QD layers in such a device must be thus limited to prevent the aggregation of strain in the InAs/InGaAs/GaAs non-lattice- matched material system. The approach being followed in the DWELL-QDIP research is to embed In- GaAs QDs in GaAs/AlGaAs multi-quantum- well (MQW) structures (see figure). This material system can accommodate a large number of QD layers without excessive lattice-mismatch strain and the associated degradation of photodetection properties. Hence, this material

  14. Towards Human-Centred Design

    Science.gov (United States)

    Bannon, Liam J.

    The field of HCI has evolved and expanded dramatically since its origin in the early 1980’s. The HCI community embraces a large community of researchers and practitioners around the world, from a variety of disciplinary backgrounds in the human and social sciences, engineering and informatics, and more recently, the arts and design disciplines. This kaleidoscope of cultures and disciplines as seen at INTERACT Conferences provides a rich pool of resources for examining our field. Applications are increasingly exploring our full range of sensory modalities, and merging the digital and physical worlds. WiFi has opened up a huge design space for mobile applications. A focus on usability of products and services has been complemented by an emphasis on engagement, enjoyment and experience. With the advent of ubiquitous computing, and the emergence of “The Internet of Things”, new kinds of more open infrastructures make possible radically new kinds of applications. The sources of innovation have also broadened, to include human and social actors outside of the computing and design organizations. The question is to what extent is our mainstream thinking in the HCI field ready for the challenges of this Brave New World? Do the technological and social innovations that we see emerging require us to re-shape, or even, re-create, our field, or is it a case of a more gradual evolution and development of that which we already know? In this closing Keynote, I will provide a perspective on the evolution and development of the HCI field, looking backwards as well as forwards, in order to determine what are some of the changes of significance in the field. This “broad-brush” approach to what I term “ human-centred design” will be complemented by the examination of specific projects and applications, to help anchor some of the discussion. Areas such as user-centred design, participatory design, computer-supported cooperative work and learning, and interaction design, in

  15. Brightness-equalized quantum dots

    Science.gov (United States)

    Lim, Sung Jun; Zahid, Mohammad U.; Le, Phuong; Ma, Liang; Entenberg, David; Harney, Allison S.; Condeelis, John; Smith, Andrew M.

    2015-10-01

    As molecular labels for cells and tissues, fluorescent probes have shaped our understanding of biological structures and processes. However, their capacity for quantitative analysis is limited because photon emission rates from multicolour fluorophores are dissimilar, unstable and often unpredictable, which obscures correlations between measured fluorescence and molecular concentration. Here we introduce a new class of light-emitting quantum dots with tunable and equalized fluorescence brightness across a broad range of colours. The key feature is independent tunability of emission wavelength, extinction coefficient and quantum yield through distinct structural domains in the nanocrystal. Precise tuning eliminates a 100-fold red-to-green brightness mismatch of size-tuned quantum dots at the ensemble and single-particle levels, which substantially improves quantitative imaging accuracy in biological tissue. We anticipate that these materials engineering principles will vastly expand the optical engineering landscape of fluorescent probes, facilitate quantitative multicolour imaging in living tissue and improve colour tuning in light-emitting devices.

  16. Synthesis and applications of carbon dots

    OpenAIRE

    Nolan, Andrew Steven

    2015-01-01

    The use of non-invasive methods to visualise and monitor processes inside living organisms is vital in the understanding and diagnosis of disease. The work in this thesis details the synthesis and applications of a new imaging modality; carbon dots, whose inherent fluorescence and non-toxic nature makes them attractive alternatives to more traditional ‘quantum dots’. In this thesis, different methods of carbon dot synthesis were attempted in order to produce carbon dots of t...

  17. Colloidal quantum dots: synthesis, properties and applications

    Science.gov (United States)

    Brichkin, S. B.; Razumov, V. F.

    2016-12-01

    Key recent results obtained in studies of a new class of luminophores, colloidal quantum dots, are analyzed. Modern methods for the synthesis and post-synthetic treatment of colloidal quantum dots that make it possible to achieve record high quantum yield of luminescence and to modify their characteristics for specific applications are considered. Currently important avenues of research on colloidal quantum dots and the problems in and prospects for their practical applications in various fields are discussed. The bibliography includes 272 references.

  18. Occupational deprivation in an asylum centre:

    DEFF Research Database (Denmark)

    Morville, Anne-Le; Erlandsson, Lena-Karin

    2013-01-01

    explored the participants’ occupational history and its influence on their occupations in the asylum centre. A thematic analysis showed that the participants had been subjected to occupational disruption and deprivation by politically oppressive systems even before their flight. Their occupations...

  19. Symmetric centres of braided monoidal categories

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper introduces the concept of‘symmetric centres' of braided monoidal categories. Let H be a Hopf algebra with bijective antipode over a field k. We address the symmetric centre of the Yetter-Drinfel'd module category HH(yD) and show that a left Yetter-Drinfel'd module M belongs to the symmetric centre of HH(yD) if and only if M is trivial. We also study the symmetric centres of categories of representations of quasitriangular Hopf algebras and give a sufficient and necessary condition for the braid of H(M) to induce the braid of (H(H)(A),(○)A,A,φ,l,r), or equivalently, the braid of (A#H(H),(○)A,A,φ,l,r), where A is a quantum commutative H-module algebra.

  20. Identity Theft: A Study in Contact Centres

    Science.gov (United States)

    Moir, Iain; Weir, George R. S.

    This paper explores the recent phenomenon of identity theft. In particular, it examines the contact centre environment as a mechanism for this to occur. Through a survey that was conducted amongst forty-five contact centre workers in the Glasgow area we determined that contact centres can and do provide a mechanism for identity theft. Specifically, we found a particularly high incidence of agents who had previously dealt with phone calls that they considered suspicious. Furthermore, there are agents within such environments who have previously been offered money in exchange for customers' details, or who know of fellow workers who received such offers. Lastly, we identify specific practices within contact centres that may contribute to the likelihood of identity theft.

  1. Social innovation for People-Centred Development

    DEFF Research Database (Denmark)

    Hulgård, Lars; P.K., Shajahan

    2013-01-01

    Social innovation is closely related to the people-centred development (PCD) framework of knowledge production. The discussion of PCD in this chapter particularly expands on the feature of empowerment and socio-political mobilization of people in social innovation......Social innovation is closely related to the people-centred development (PCD) framework of knowledge production. The discussion of PCD in this chapter particularly expands on the feature of empowerment and socio-political mobilization of people in social innovation...

  2. Thermoelectric energy harvesting with quantum dots.

    Science.gov (United States)

    Sothmann, Björn; Sánchez, Rafael; Jordan, Andrew N

    2015-01-21

    We review recent theoretical work on thermoelectric energy harvesting in multi-terminal quantum-dot setups. We first discuss several examples of nanoscale heat engines based on Coulomb-coupled conductors. In particular, we focus on quantum dots in the Coulomb-blockade regime, chaotic cavities and resonant tunneling through quantum dots and wells. We then turn toward quantum-dot heat engines that are driven by bosonic degrees of freedom such as phonons, magnons and microwave photons. These systems provide interesting connections to spin caloritronics and circuit quantum electrodynamics.

  3. Activation of silicon quantum dots for emission

    Institute of Scientific and Technical Information of China (English)

    Huang Wei-Qi; Miao Xin-Jian; Huang Zhong-Mei; Liu Shi-Rong; Qin Chao-Jian

    2012-01-01

    The emission of silicon quantum dots is weak when their surface is passivated well. Oxygen or nitrogen on the surface of silicon quantum dots can break the passivation to form localized electronic states in the band gap to generate active centers where stronger emission occurs.From this point of view,we can build up radiative matter for emission.Emissions of various wavelengths can be obtained by controlling the surface bonds of silicon quantum dots.Our experimental results demonstrate that annealing is important in the treatment of the activation,and stimulated emissions at about 600 and 700 nm take place on active silicon quantum dots.

  4. Synthetic Developments of Nontoxic Quantum Dots.

    Science.gov (United States)

    Das, Adita; Snee, Preston T

    2016-03-03

    Semiconductor nanocrystals, or quantum dots (QDs), are candidates for biological sensing, photovoltaics, and catalysis due to their unique photophysical properties. The most studied QDs are composed of heavy metals like cadmium and lead. However, this engenders concerns over heavy metal toxicity. To address this issue, numerous studies have explored the development of nontoxic (or more accurately less toxic) quantum dots. In this Review, we select three major classes of nontoxic quantum dots composed of carbon, silicon and Group I-III-VI elements and discuss the myriad of synthetic strategies and surface modification methods to synthesize quantum dots composed of these material systems.

  5. POLARON IN CYLINDRICAL AND SPHERICAL QUANTUM DOTS

    Directory of Open Access Journals (Sweden)

    L.C.Fai

    2004-01-01

    Full Text Available Polaron states in cylindrical and spherical quantum dots with parabolic confinement potentials are investigated applying the Feynman variational principle. It is observed that for both kinds of quantum dots the polaron energy and mass increase with the increase of Frohlich electron-phonon coupling constant and confinement frequency. In the case of a spherical quantum dot, the polaron energy for the strong coupling is found to be greater than that of a cylindrical quantum dot. The energy and mass are found to be monotonically increasing functions of the coupling constant and the confinement frequency.

  6. Random Feature Maps for Dot Product Kernels

    CERN Document Server

    Kar, Purushottam

    2012-01-01

    Approximating non-linear kernels using feature maps has gained a lot of interest in recent years due to applications in reducing training and testing times of SVM classifiers and other kernel based learning algorithms. We extend this line of work and present low distortion embeddings for dot product kernels into linear Euclidean spaces. We base our results on a classical result in harmonic analysis characterizing all dot product kernels and use it to define randomized feature maps into explicit low dimensional Euclidean spaces in which the native dot product provides an approximation to the dot product kernel with high confidence.

  7. Semiconductor quantum-dot lasers and amplifiers

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Borri, Paola; Ledentsov, N. N.

    2002-01-01

    -power surface emitting VCSELs. We investigated the ultrafast dynamics of quantum-dot semiconductor optical amplifiers. The dephasing time at room temperature of the ground-state transition in semiconductor quantum dots is around 250 fs in an unbiased amplifier, decreasing to below 50 fs when the amplifier...... is biased to positive net gain. We have further measured gain recovery times in quantum dot amplifiers that are significantly lower than in bulk and quantum-well semiconductor optical amplifiers. This is promising for future demonstration of quantum dot devices with high modulation bandwidth...

  8. Dissipative tunneling in structures with quantum dots and quantum molecules

    OpenAIRE

    Dahnovsky, Yu. I.; Krevchik, V. D.; Semenov, M. B.; Yamamoto, K.; Zhukovsky, V. Ch.; Aringazin, A. K.; Kudryashov, E. I.; Mayorov, V. G.

    2005-01-01

    The problem of tunneling control in systems "quantum dot - quantum well" (as well as "quantum dot - quantum dot" or quantum molecule) and "quantum dot - bulk contact" is studied as a quantum tunneling with dissipation process in the semiclassical (instanton) approximation. For these systems temperature and correlation between a quantum dot radius and a quantum well width (or another quantum dot radius) are considered to be control parameters. The condition for a single electron blockade is fo...

  9. The Imperial College Thermophysical Properties Data Centre

    Science.gov (United States)

    Angus, S.; Cole, W. A.; Craven, R.; de Reuck, K. M.; Trengove, R. D.; Wakeham, W. A.

    1986-07-01

    The IUPAC Thermodynamic Tables Project Centre in London has at its disposal considerable expertise on the production and utilization of high-accuracy equations of state which represent the thermodynamic properties of substances. For some years they have been content to propagate this information by the traditional method of book production, but the increasing use of the computer in industry for process design has shown that an additional method was needed. The setting up of the IUPAC Transport Properties Project Centre, also at Imperial College, whose products would also be in demand by industry, afforded the occasion for a new look at the problem. The solution has been to set up the Imperial College Thermophysical Properties Data Centre, which embraces the two IUPAC Project Centres, and for it to establish a link with the existing Physical Properties Data Service of the Institution of Chemical Engineers, thus providing for the dissemination of the available information without involving the Centres in problems such as those of marketing and advertising. This paper outlines the activities of the Centres and discusses the problems in bringing their products to the attention of industry in suitable form.

  10. Perspectives on recycling centres and future developments.

    Science.gov (United States)

    Engkvist, I-L; Eklund, J; Krook, J; Björkman, M; Sundin, E

    2016-11-01

    The overall aim of this paper is to draw combined, all-embracing conclusions based on a long-term multidisciplinary research programme on recycling centres in Sweden, focussing on working conditions, environment and system performance. A second aim is to give recommendations for their development of new and existing recycling centres and to discuss implications for the future design and organisation. Several opportunities for improvement of recycling centres were identified, such as design, layout, ease with which users could sort their waste, the work environment, conflicting needs and goals within the industry, and industrialisation. Combining all results from the research, which consisted of different disciplinary aspects, made it possible to analyse and elucidate their interrelations. Waste sorting quality was recognized as the most prominent improvement field in the recycling centre system. The research identified the importance of involving stakeholders with different perspectives when planning a recycling centre in order to get functionality and high performance. Practical proposals of how to plan and build recycling centres are given in a detailed checklist.

  11. Quantum Dot Spectrum Converters for Enhanced High Efficiency Photovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research proposes to enhance solar cell efficiency, radiation resistance and affordability. The Quantum Dot Spectrum Converter (QDSC) disperses quantum dots...

  12. Transmission of HIV in dialysis centre.

    Science.gov (United States)

    Velandia, M; Fridkin, S K; Cárdenas, V; Boshell, J; Ramirez, G; Bland, L; Iglesias, A; Jarvis, W

    1995-06-01

    In August, 1993, 13 dialysis patients at one dialysis centre in Colombia, South America, were found to be HIV positive, and this prompted an epidemiological investigation. We carried out a cohort study of all dialysis centre patients during January, 1992 to December, 1993 (epidemic period) to determine risk factors for HIV seroconversion. Haemodialysis and medical records were reviewed, dialysis centre staff and surviving patients were interviewed, and dialysis practices were observed. Stored sera from all dialysis centre patients were tested for HIV antibody. 12 (52%) of 23 patients tested positive for HIV antibody by enzyme immunoassay and western blot during the epidemic period. Of the 23 tested, 9 (39%) converted from HIV antibody negative to positive (seroconverters) and 10 (44%) remained HIV negative (seronegatives). The HIV seroconversion rate was higher among patients dialysed at the centre while a new patient, who was HIV seropositive, was dialysed there (90% vs 0%; p dialysis centre reprocessed access needles, dialysers, and bloodlines (60% vs 0%). While 2 of 9 HIV seroconverters had had sex with prostitutes, none had received unscreened blood products or had other HIV risk factors. No surgical or dental procedures were associated with HIV seroconversion. Dialysers were reprocessed separately with 5% formaldehyde and were labelled for use on the same patient. Access needles were reprocessed by soaking them in a common container with a low-level disinfectant, benzalkonium chloride; 4 pairs of needles were placed in one pan creating the potential for cross-contamination or use of one patient's needles on another patient. HIV transmission at the dialysis centre was confirmed. Improperly reprocessed patient-care equipment, most probably access needles, is the likely mechanism of transmission. This outbreak was discovered by accident and similar transmission may be occurring in many other countries where low-level disinfectants are used to sterilise critical

  13. Nitrogen-Doped Carbon Dots for "green" Quantum Dot Solar Cells.

    Science.gov (United States)

    Wang, Hao; Sun, Pengfei; Cong, Shan; Wu, Jiang; Gao, Lijun; Wang, Yun; Dai, Xiao; Yi, Qinghua; Zou, Guifu

    2016-12-01

    Considering the environment protection, "green" materials are increasingly explored for photovoltaics. Here, we developed a kind of quantum dots solar cell based on nitrogen-doped carbon dots. The nitrogen-doped carbon dots were prepared by direct pyrolysis of citric acid and ammonia. The nitrogen-doped carbon dots' excitonic absorption depends on the N-doping content in the carbon dots. The N-doping can be readily modified by the mass ratio of reactants. The constructed "green" nitrogen-doped carbon dots solar cell achieves the best power conversion efficiency of 0.79 % under AM 1.5 G one full sun illumination, which is the highest efficiency for carbon dot-based solar cells.

  14. Thick-shell nanocrystal quantum dots

    Science.gov (United States)

    Hollingsworth, Jennifer A.; Chen, Yongfen; Klimov, Victor I.; Htoon, Han; Vela, Javier

    2011-05-03

    Colloidal nanocrystal quantum dots comprising an inner core having an average diameter of at least 1.5 nm and an outer shell, where said outer shell comprises multiple monolayers, wherein at least 30% of the quantum dots have an on-time fraction of 0.80 or greater under continuous excitation conditions for a period of time of at least 10 minutes.

  15. Optically active quantum-dot molecules.

    Science.gov (United States)

    Shlykov, Alexander I; Baimuratov, Anvar S; Baranov, Alexander V; Fedorov, Anatoly V; Rukhlenko, Ivan D

    2017-02-20

    Chiral molecules made of coupled achiral semiconductor nanocrystals, also known as quantum dots, show great promise for photonic applications owing to their prospective uses as configurable building blocks for optically active structures, materials, and devices. Here we present a simple model of optically active quantum-dot molecules, in which each of the quantum dots is assigned a dipole moment associated with the fundamental interband transition between the size-quantized states of its confined charge carriers. This model is used to analytically calculate the rotatory strengths of optical transitions occurring upon the excitation of chiral dimers, trimers, and tetramers of general configurations. The rotatory strengths of such quantum-dot molecules are found to exceed the typical rotatory strengths of chiral molecules by five to six orders of magnitude. We also study how the optical activity of quantum-dot molecules shows up in their circular dichroism spectra when the energy gap between the molecular states is much smaller than the states' lifetime, and maximize the strengths of the circular dichroism peaks by optimizing orientations of the quantum dots in the molecules. Our analytical results provide clear design guidelines for quantum-dot molecules and can prove useful in engineering optically active quantum-dot supercrystals and photonic devices.

  16. Research on Self-Assembling Quantum Dots.

    Science.gov (United States)

    1995-10-30

    0K. in a second phase of this contract we turned our efforts to the fabrication and studies of self assembled quantum dots . We first demonstrated a...method for producing InAs-GasAs self assembled quantum dots (SAD) using MBE. (AN)

  17. Double Acceptor Interaction in Semimagnetic Quantum Dot

    Directory of Open Access Journals (Sweden)

    A. Merwyn Jasper D. Reuben

    2011-01-01

    Full Text Available The effect of geometry of the semimagnetic Quantum Dot on the Interaction energy of a double acceptor is computed in the effective mass approximation using the variational principle. A peak is observed at the lower dot sizes as a magnetic field is increased which is attributed to the reduction in confinement.

  18. Quantum Dots Coupled to a Superconductor

    DEFF Research Database (Denmark)

    Jellinggaard, Anders Robert

    are tuned electrostatically. This includes tuning the odd occupation of the dot through a quantum phase transition, where it forms a singlet with excitations in the superconductor. We detail the fabrication of these bottom gated devices, which additionally feature ancillary sensor dots connected...

  19. Detecting the chirality for coupled quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Cao Huijuan [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China); Hu Lian [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China)], E-mail: huliancaohj@yahoo.com

    2008-04-21

    We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots.

  20. Optical anisotropy in vertically coupled quantum dots

    DEFF Research Database (Denmark)

    Yu, Ping; Langbein, Wolfgang Werner; Leosson, Kristjan;

    1999-01-01

    We have studied the polarization of surface and edge-emitted photoluminescence (PL) from structures with vertically coupled In0.5Ga0.5As/GaAs quantum dots (QD's) grown by molecular beam epitaxy. The PL polarization is found to be strongly dependent on the number of stacked layers. While single...... number due to increasing dot size....

  1. Optical studies of capped quantum dots

    NARCIS (Netherlands)

    Wuister, S.F.

    2005-01-01

    This thesis describes the synthesis and spectroscopy of CdSe and CdTe semiconductor quantum dots (QDs). The first chapter gives an introduction into the unique size dependent properties of semiconductor quantum dots. Highly luminescent QDs of CdSe and CdTe were prepared via a high temperature method

  2. Optical Properties of Semiconductor Quantum Dots

    NARCIS (Netherlands)

    Perinetti, U.

    2011-01-01

    This thesis presents different optical experiments performed on semiconductor quantum dots. These structures allow to confine a small number of electrons and holes to a tiny region of space, some nm across. The aim of this work was to study the basic properties of different types of quantum dots mad

  3. Scavenger hunt in the CERN Computing Centre

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    Hidden among the racks of servers and disks in the CERN Computing Centre, you’ll find Hawaiian dancers, space aliens, gorillas… all LEGO® figurines! These characters were placed about the Centre for the arrival of Google’s Street View team for the world to discover.   PLEASE NOTE THAT THE COMPETITION IS OVER. ONLY FOR REFERENCE, HERE IS THE ORIGINAL ARTICLE. We’re pleased to announce our first global scavenger hunt! Spot three LEGO® figurines using Google’s Street View and you’ll be entered to win a gift of your choice from our CERN Gift Guide. A LEGO® figurine in the CERN Computing Centre, as seen on Google Street View. Here are the details: Find at least three LEGO® figurines hidden around the CERN Computing Centre using Google Street View.   Take screencaps of the figurines and e-mail the pictures to TreasureHunt-ComputingCentre@cern.ch. This email is no longer active.   The...

  4. Visits to Tier-1 Computing Centres

    CERN Multimedia

    Dario Barberis

    At the beginning of 2007 it became clear that an enhanced level of communication is needed between the ATLAS computing organisation and the Tier-1 centres. Most usual meetings are ATLAS-centric and cannot address the issues of each Tier-1; therefore we decided to organise a series of visits to the Tier-1 centres and focus on site issues. For us, ATLAS computing management, it is most useful to realize how each Tier-1 centre is organised, and its relation to the associated Tier-2s; indeed their presence at these visits is also very useful. We hope it is also useful for sites... at least, we are told so! The usual participation includes, from the ATLAS side: computing management, operations, data placement, resources, accounting and database deployment coordinators; and from the Tier-1 side: computer centre management, system managers, Grid infrastructure people, network, storage and database experts, local ATLAS liaison people and representatives of the associated Tier-2s. Visiting Tier-1 centres (1-4). ...

  5. Coherent control of quantum dots

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Lodahl, Peter; Hvam, Jørn Märcher

    In recent years much effort has been devoted to the use of semiconductor quantum dotsystems as building blocks for solid-state-based quantum logic devices. One importantparameter for such devices is the coherence time, which determines the number ofpossible quantum operations. From earlier...... measurements the coherence time of the selfassembledquantum dots (QDs) has been reported to be limited by the spontaneousemission rate at cryogenic temperatures1.In this project we propose to alter the coherence time of QDs by taking advantage of arecent technique on modifying spontaneous emission rates...

  6. Biocompatible quantum dots for biological applications.

    Science.gov (United States)

    Rosenthal, Sandra J; Chang, Jerry C; Kovtun, Oleg; McBride, James R; Tomlinson, Ian D

    2011-01-28

    Semiconductor quantum dots are quickly becoming a critical diagnostic tool for discerning cellular function at the molecular level. Their high brightness, long-lasting, size-tunable, and narrow luminescence set them apart from conventional fluorescence dyes. Quantum dots are being developed for a variety of biologically oriented applications, including fluorescent assays for drug discovery, disease detection, single protein tracking, and intracellular reporting. This review introduces the science behind quantum dots and describes how they are made biologically compatible. Several applications are also included, illustrating strategies toward target specificity, and are followed by a discussion on the limitations of quantum dot approaches. The article is concluded with a look at the future direction of quantum dots.

  7. Quantum-dot supercrystals for future nanophotonics

    Science.gov (United States)

    Baimuratov, Anvar S.; Rukhlenko, Ivan D.; Turkov, Vadim K.; Baranov, Alexander V.; Fedorov, Anatoly V.

    2013-01-01

    The study of supercrystals made of periodically arranged semiconductor quantum dots is essential for the advancement of emerging nanophotonics technologies. By combining the strong spatial confinement of elementary excitations inside quantum dots and exceptional design flexibility, quantum-dot supercrystals provide broad opportunities for engineering desired optical responses and developing superior light manipulation techniques on the nanoscale. Here we suggest tailoring the energy spectrum and wave functions of the supercrystals' collective excitations through the variation of different structural and material parameters. In particular, by calculating the excitonic spectra of quantum dots assembled in two-dimensional Bravais lattices we demonstrate a wide variety of spectrum transformation scenarios upon alterations in the quantum dot arrangement. This feature offers unprecedented control over the supercrystal's electromagnetic properties and enables the development of new nanophotonics materials and devices.

  8. Effect of different uranium compounds on the properties of U-Pt-Y-Ba-O double-perovskite pinning centres in textured Y-Ba-Cu-O superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Sawh, Ravi-Persad; Weinstein, Roy; Parks, Drew; Gandini, Alberto [Beam Particle Dynamics Laboratories, University of Houston, Houston, TX 77204-5005 (United States); Department of Physics, University of Houston, Houston, TX 77204-5005 (United States); Texas Center for Superconductivity and Advanced Materials, University of Houston, Houston, TX 77204-5005 (United States)

    2005-02-01

    An experiment was performed to test the effect of different uranium compounds on the properties of chemical pinning centres. UO{sub 2}, UO{sub 3}, and UO{sub 4}{center_dot}2H{sub 2}O wereadmixed to Y 123+Pt, and textured. Tests of J{sub c} via measurements of trapped field (B{sub trap}) indicate a clear dependence of B{sub trap} on the U compound admixed to create the pinning centres. In all three cases there is a monotonic increase in B{sub trap} as the mass (M{sub U}) of U is increased. However, the magnitude of the increase in B{sub trap} depends on the admixed U compound. The highest increase in B{sub trap} is measured in samples doped with UO{sub 4}{center_dot}2H{sub 2}O, and the lowest is obtained in samples doped with UO{sub 2}. Microstructure studies indicate that the composition of the U-rich pinning deposits is the same in all three cases, i.e. all are the previously identified (U{sub 0.6}Pt{sub 0.4})Y Ba{sub 2}O{sub 6} compound. The primary difference among the three types of samples is that the size of the U-Pt-Y-Ba-O pinning deposits depends on the admixed U compound. While all are in the nanometre domain, the diameter of these deposits was markedly larger in UO{sub 2} doped samples than in UO{sub 3} doped samples, and smallest in UO{sub 4}{center_dot}2H{sub 2}O doped samples. Because some form of poisoning limits the amount of U that can be added to create pinning centres, to M{sub U} {approx}1 wt%, smaller deposits result in a greater number of pinning centres. We conclude that UO{sub 4}{center_dot}2H{sub 2}O is more effective than either UO{sub 3} or UO{sub 2} in the formation of U-Pt-Y-Ba-O pinning centres because of diminished pinning centre size, and consequent increase in pinning centre density.

  9. The Aube centre. 1997 statement; Le centre de l`Aube. Bilan 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-09-01

    Since January 1992 the Aube centre ensures the storage of 90% of the short life radioactive wastes produced in France. This educational booklet describes the organization of the activities in the centre from the storage of wastes to the radioactivity surveillance of the environment (air, surface and ground waters, river sediments, plants and milk). (J.S.)

  10. Blood Compatibility Evaluations of Fluorescent Carbon Dots.

    Science.gov (United States)

    Li, Sha; Guo, Zhong; Zhang, Yi; Xue, Wei; Liu, Zonghua

    2015-09-02

    Because of their unique advantages, fluorescent carbon dots are gaining popularity in various biomedical applications. For these applications, good biosafety is a prerequisite for their use in vivo. Studies have reported the preliminary biocompatibility evaluations of fluorescent carbon dots (mainly cytotoxicity); however, to date, little information is available about their hemocompatibility, which could impede their development from laboratory to bedside. In this work, we evaluated the hemocompatibility of fluorescent carbon dots, which we prepared by hydrothermal carbonization of α-cyclodextrin. The effects of the carbon dots on the structure and function of key blood components were investigated at cellular and molecular levels. In particular, we considered the morphology and lysis of human red blood cells, the structure and conformation of the plasma protein fibrinogen, the complement activation, platelet activation, and in vitro and in vivo blood coagulation. We found that the carbon dots have obvious concentration-dependent effects on the blood components. Overall, concentrations of the fluorescent carbon dots at ≤0.1 mg/mL had few adverse effects on the blood components, but at higher doses, the carbon dots impair the structure and function of the blood components, causing morphological disruptions and lysis of red blood cells, interference in the local microenvironments of fibrinogen, activation of the complement system, and disturbances in the plasma and whole blood coagulation function in vitro. However, the carbon dots tend to activate platelets only at low concentrations. Intravenous administration of the carbon dots at doses up to 50 mg/kg did not impair the blood coagulation function. These results provide valuable information for the clinical application of fluorescent carbon dots.

  11. Peptide dot immunoassay and immunoblotting: electroblotting from aluminum thin-layer chromatography plates and isoelectric focusing gels to activated nitrocellulose

    DEFF Research Database (Denmark)

    Bjerrum, O.J.; Holm, A.; Lauritzen, Edgar;

    1993-01-01

    Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins......Peptide dot immunoassay, electroblotting, activated nitrocellulose, dot blot, membranes, peptides and proteins...

  12. Learning Styles of Independent Learning Centre Users

    Directory of Open Access Journals (Sweden)

    Tarik Uzun

    2014-09-01

    Full Text Available Learning style research has been a significant field within language teaching and learning. There have been very few attempts, however, to seek possible links between independent learning and learning style preferences. This paper aims to identify the learning styles of students who use the Independent Learning Centre (ILC on a regular basis at a state university in Turkey (n=102. The findings of the learning style analysis revealed that, contrary to expectations, most of the regular users of the centre were synoptic learners, which implies that these learners might not necessarily have conscious control over their own learning processes. An in-depth analysis of learning styles and recommendations to improve the services offered in the centre are also included in the paper.

  13. A day in the CERN Control Centre

    CERN Multimedia

    Rosaria Marraffino

    2015-01-01

    The CERN Control Centre (CCC) is the nerve centre of the CERN beam systems. From this room, the experts prepare, monitor, adjust, and control the particle beams that circulate throughout the accelerator complex while ensuring that the services and the technical infrastructure work flawlessly. Buttons, screens, telephones, lights (but no sound): in the CCC, everything is ready to make it possible for the LHC to reach the unprecedented energies expected at Run 2.   Seen from above, the CERN Control Centre resembles the shape of a quadrupole magnet. The consoles are distributed in four circles, called “islands”, dedicated to the LHC, the SPS, the PS Complex and the Technical Infrastructure (TI) respectively. Spread between TI and LHC are the Cryogenics consoles. Being in the same room allows the 24h-manned islands to be constantly in touch with one another, thus ensuring the best performance of the machines. At the LHC island, operators are currently busy training the magnet...

  14. THE ELUSIVENESS OF LEARNER-CENTRED TEACHING

    Directory of Open Access Journals (Sweden)

    Ervin Kovačević

    2016-03-01

    Full Text Available This research will explore teaching styles of university professors. Teaching style is an umbrella term for teaching decisions made during the entire teaching process – planning, delivery, and evaluation. Contemporary university teachers are advised to adopt the learner-centred teaching style which is assumed to produce remarkable possibilities. In the Fall Semester 2015 fifty-two respondents in different faculties of International University of Sarajevo were surveyed using The Principles of Adult Learning Scale inventory designed by Gary J. Conti. Inventory scores were calculated according to guidelines suggested by the author of the inventory. The scores revealed that majority of respondents strongly supported teacher-centred rather than learner-centred styles of instruction. Scores were analysed on gender lines and across three different faculties, namely: Arts and Social Sciences; Business and Administration; Engineering and Natural Sciences. In all five groups none of the seven teaching style indicators was found to conform with the learner-centred teaching criteria. There was no statistically significant difference between the two genders’ preference for a teaching style. And there was no statistically significant difference between teaching style preference across the three different faculties.The results of this research imply that the learner-centred style of instruction is not frequently implemented. Secondly, the results indicate that the requirements necessary for proper application of the learner-centred teaching style are not easy to meet in current written and unwritten norms. Finally, the results show that traditional teaching styles, which have been preserved in different scientific fields, still predominate in universities.

  15. Enhancing person-centred communication in NICU

    DEFF Research Database (Denmark)

    Weis, Janne; Zoffmann, Vibeke; Egerod, Ingrid

    2015-01-01

    Aims of this article were (a) to explore how parents of premature infants experience guided family-centred care (GFCC), and (b) to compare how parents receiving GFCC versus standard care (SC) describe nurse-parent communication in the neonatal intensive care unit.......Aims of this article were (a) to explore how parents of premature infants experience guided family-centred care (GFCC), and (b) to compare how parents receiving GFCC versus standard care (SC) describe nurse-parent communication in the neonatal intensive care unit....

  16. Byurakan Astrophysical Observatory as Cultural Centre

    Science.gov (United States)

    Mickaelian, A. M.; Farmanyan, S. V.

    2016-12-01

    NAS RA V. Ambartsumian Byurakan Astrophysical Observatory is presented as a cultural centre for Armenia and the Armenian nation in general. Besides being scientific and educational centre, the Observatory is famous for its unique architectural ensemble, rich botanical garden and world of birds, as well as it is one of the most frequently visited sightseeing of Armenia. In recent years, the Observatory has also taken the initiative of the coordination of the Cultural Astronomy in Armenia and in this field, unites the astronomers, historians, archaeologists, ethnographers, culturologists, literary critics, linguists, art historians and other experts.

  17. Electron transport in quantum dots

    CERN Document Server

    2003-01-01

    When I was contacted by Kluwer Academic Publishers in the Fall of 200 I, inviting me to edit a volume of papers on the issue of electron transport in quantum dots, I was excited by what I saw as an ideal opportunity to provide an overview of a field of research that has made significant contributions in recent years, both to our understanding of fundamental physics, and to the development of novel nanoelectronic technologies. The need for such a volume seemed to be made more pressing by the fact that few comprehensive reviews of this topic have appeared in the literature, in spite of the vast activity in this area over the course of the last decade or so. With this motivation, I set out to try to compile a volume that would fairly reflect the wide range of opinions that has emerged in the study of electron transport in quantum dots. Indeed, there has been no effort on my part to ensure any consistency between the different chapters, since I would prefer that this volume instead serve as a useful forum for the...

  18. Chiral quantum dot based materials

    Science.gov (United States)

    Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii

    2014-05-01

    Recently, the use of stereospecific chiral stabilising molecules has also opened another avenue of interest in the area of quantum dot (QD) research. The main goal of our research is to develop new types of technologically important quantum dot materials containing chiral defects, study their properties and explore their applications. The utilisation of chiral penicillamine stabilisers allowed the preparation of new water soluble white emitting CdS quantum nanostructures which demonstrated circular dichroism in the band-edge region of the spectrum. It was also demonstrated that all three types of QDs (D-, L-, and Rac penicillamine stabilised) show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. In this work the chiral CdS based quantum nanostructures have also been doped by copper metal ions and new chiral penicilamine stabilized CuS nanoparticles have been prepared and investigated. It was found that copper doping had a strong effect at low levels in the synthesis of chiral CdS nanostructures. We expect that this research will open new horizons in the chemistry of chiral nanomaterials and their application in biotechnology, sensing and asymmetric synthesis.

  19. [Accreditation criteria and quality standards for Poisons centres: development of a quality management system within the Milan Poisons centre].

    Science.gov (United States)

    Della Puppa, Tiziana; Manfrè, Sergio; Grezzi, Marinella

    2006-01-01

    Poisons centres throughout Italy and Europe vary considerably in terms of their institutions and organisation. The European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) has laid down the activities that a poisons centre must carry out, specifying minimum and maximum standards required. These directions allow an evaluation of the service provided. In 2002 Milan Poisons Centre began a project aiming to introduce concepts and methodology proper of the quality systems within poisons centres' institutional activity. Concluded, the project resulted in the centre's certification and the documentation of its procedures: this may now contribute to help define the status and activity of poisons centres in Italy.

  20. Quantum dots with single-atom precision.

    Science.gov (United States)

    Fölsch, Stefan; Martínez-Blanco, Jesús; Yang, Jianshu; Kanisawa, Kiyoshi; Erwin, Steven C

    2014-07-01

    Quantum dots are often called artificial atoms because, like real atoms, they confine electrons to quantized states with discrete energies. However, although real atoms are identical, most quantum dots comprise hundreds or thousands of atoms, with inevitable variations in size and shape and, consequently, unavoidable variability in their wavefunctions and energies. Electrostatic gates can be used to mitigate these variations by adjusting the electron energy levels, but the more ambitious goal of creating quantum dots with intrinsically digital fidelity by eliminating statistical variations in their size, shape and arrangement remains elusive. We used a scanning tunnelling microscope to create quantum dots with identical, deterministic sizes. By using the lattice of a reconstructed semiconductor surface to fix the position of each atom, we controlled the shape and location of the dots with effectively zero error. This allowed us to construct quantum dot molecules whose coupling has no intrinsic variation but could nonetheless be tuned with arbitrary precision over a wide range. Digital fidelity opens the door to quantum dot architectures free of intrinsic broadening-an important goal for technologies from nanophotonics to quantum information processing as well as for fundamental studies of confined electrons.

  1. [The coordination of care in health centres].

    Science.gov (United States)

    Ribardière, Olivia

    2016-06-01

    Health centres are structurally designed to facilitate the coordination of care. However, evolutions in society have resulted in forms of consumption of health care which are not necessarily compatible with efficient care coordination. On a local level, teams are nevertheless organising and structuring themselves to offer the right form of care, to the right patient and at the right time.

  2. Tensions in human-centred design

    NARCIS (Netherlands)

    Steen, M.G.D.

    2011-01-01

    In human-centred design (HCD), researchers and designers attempt to cooperate with and learn from potential users of the products or services which they are developing. Their goal is to develop products or services that match users' practices, needs and preferences. In this position paper it is argu

  3. Frequency selectivity at very low centre frequencies

    DEFF Research Database (Denmark)

    Orellana, Carlos Andrés Jurado; Pedersen, Christian Sejer; Marquardt, Torsten

    2010-01-01

    -3638 (2007)]. Recent experiments showed that the exact frequency varies from individual to individual. Besides, the helicotrema region in the METF has been found to highly influence frequency selectivity for centre frequencies (CFs) below 80 Hz (Jurado and Moore in prep). By using individual METF...

  4. Visiting a science centre: what's on offer?

    Science.gov (United States)

    Russell, Ian

    1990-09-01

    Science centres are a valuable resource, used more frequently by family groups and primary school parties than by secondary schools. The importance of affective learning, involving attitude changes, is stressed. Provided the right approach is used, accompanying adults can help children get the most out of a visit.

  5. Mandibular trauma: a two-centre study

    NARCIS (Netherlands)

    Boffano, P.; Kommers, S.C.; Karagozoglu, K.H.; Gallesio, C.; Forouzanfar, T.

    2015-01-01

    The aims of this study were to assess and compare epidemiological data on mandibular fractures from two European centres and to perform a review of the literature. Between 2001 and 2010, a total of 752 patients with a total of 1167 mandibular fractures were admitted to a hospital in Turin, and 245 p

  6. Renovation of the CERN Computer Centre

    CERN Multimedia

    Patrice Loïez

    2003-01-01

    The Computer Centre at CERN is seen after half of the equipment is the large ground floor room has been removed. A large-scale spring-cleaning operation took place before renovation work for the new CERN Grid system began. Fifteen kilometres of cables that were no longer needed were removed from the cavity floor for recycling.

  7. Cactus: The Centres of a Triangle

    Science.gov (United States)

    Hyde, Hartley

    2009-01-01

    This is the first of two articles which describe how to use "JavaSketchPad" to explore the centres of a triangle. This introductory exercise is suggested in the GSP "Workshop Guide". Students can use "JavaSketchPad Interactive Geometry" (JSP) at home at no cost. They are likely to impress their parents with their enthusiasm for geometry and all…

  8. Scanning gate microscopy of ultra clean carbon nanotube quantum dots

    OpenAIRE

    Xue, Jiamin; Dhall, Rohan; Cronin, Stephen B.; LeRoy, Brian J.

    2015-01-01

    We perform scanning gate microscopy on individual suspended carbon nanotube quantum dots. The size and position of the quantum dots can be visually identified from the concentric high conductance rings. For the ultra clean devices used in this study, two new effects are clearly identified. Electrostatic screening creates non-overlapping multiple sets of Coulomb rings from a single quantum dot. In double quantum dots, by changing the tip voltage, the interactions between the quantum dots can b...

  9. An evaluation of the dot-ELISA procedure as a diagnostic test in an area with a high prevalence of human Toxocara canis infection

    Directory of Open Access Journals (Sweden)

    María V Bojanich

    2012-03-01

    Full Text Available The aim of this work was to evaluate a dot-enzyme-linked immunosorbent assay (dot-ELISA using excretory-secretory antigens from the larval stages of Toxocara canis for the diagnosis of toxocariasis. A secondary aim was to establish the optimal conditions for its use in an area with a high prevalence of human T. canis infection. The dot-ELISA test was standardised using different concentrations of the antigen fixed on nitrocellulose paper strips and increasing dilutions of the serum and conjugate. Both the dot-ELISA and standard ELISA methods were tested in parallel with the same batch of sera from controls and from individuals living in the problem area. The best results were obtained with 1.33 µg/mL of antigen, dilutions of 1/80 for the samples and controls and a dilution of 1/5,000 for the anti-human IgG-peroxidase conjugate. All steps of the procedure were performed at room temperature. The coincidence between ELISA and dot-ELISA was 85% and the kappa index was 0.72. The dot-ELISA test described here is rapid, easy to perform and does not require expensive equipment. Thus, this test is suitable for the serological diagnosis of human T. canis infection in field surveys and in the primary health care centres of endemic regions.

  10. Time-bin Entanglement from Quantum Dots

    CERN Document Server

    Weihs, Gregor; Predojević, Ana

    2016-01-01

    The desire to have a source of single entangled photon pairs can be satisfied using single quantum dots as emitters. However, we are not bound to pursue only polarization entanglement, but can also exploit other degrees of freedom. In this chapter we focus on the time degree of freedom, to achieve so-called time-bin entanglement. This requires that we prepare the quantum dot coherently into the biexciton state and also build special interferometers for analysis. Finally this technique can be extended to achieve time-bin and polarization hyper-entanglement from a suitable quantum dot.

  11. Fluorescent Quantum Dots for Biological Labeling

    Science.gov (United States)

    McDonald, Gene; Nadeau, Jay; Nealson, Kenneth; Storrie-Lomardi, Michael; Bhartia, Rohit

    2003-01-01

    Fluorescent semiconductor quantum dots that can serve as "on/off" labels for bacteria and other living cells are undergoing development. The "on/off" characterization of these quantum dots refers to the fact that, when properly designed and manufactured, they do not fluoresce until and unless they come into contact with viable cells of biological species that one seeks to detect. In comparison with prior fluorescence-based means of detecting biological species, fluorescent quantum dots show promise for greater speed, less complexity, greater sensitivity, and greater selectivity for species of interest. There are numerous potential applications in medicine, environmental monitoring, and detection of bioterrorism.

  12. Quantum dot devices for optical communications

    DEFF Research Database (Denmark)

    Mørk, Jesper

    2005-01-01

    . The main property of semiconductor quantum dots compared to bulk material or even quantum well structures is the discrete nature of the allowed states, which means that inversion of the medium can be obtained for very low electron densities. This has led to the fabrication of quantum dot lasers with record......-low threshold currents and amplifiers with record-high power levels. In this tutorial we will review the basic properties of quantum dots, emphasizing the properties which are important for laser and amplifier applications, as well as devices for all-optical signal processing. The high-speed properties...

  13. Electronic properties of aperiodic quantum dot chains

    Science.gov (United States)

    Korotaev, P. Yu.; Vekilov, Yu. Kh.; Kaputkina, N. E.

    2012-04-01

    The electronic spectral and transport properties of aperiodic quantum dot chains are investigated. The systems with singular continuous energy spectrum are considered: Thue-Morse chain, double-periodic chain, Rudin-Shapiro chain. The influence of electronic energy in quantum dot on the spectral properties, band structure, density of states and spectral resistivity, is discussed. Low resistivity regions correspond to delocalized states and these states could be current states. Also we discuss the magnetic field application as the way to tune electronic energy in quantum dot and to obtain metallic or insulating conducting states of the systems.

  14. Amplification Without Inversion in Semiconductor Quantum Dot

    Science.gov (United States)

    Hajibadali, A.; Abbasian, K.; Rostami, A.

    In this paper, we have realized amplification without inversion (AWI) in quantum dot (QD). A Y-type four-level system of InxGa1-xN quantum dot has been obtained and investigated for AWI. It has been shown that, with proper setting of control fields' amplitude, we can obtain reasonable gain. With proper setting of phase difference of control fields and probe field, we can obtain considerable gain in resonant wavelength. We have designed this system by solving the Schrödinger-Poisson equations for InxGa1-xN quantum dot in GaN substrate, self-consistently.

  15. Quantum Dots Investigated for Solar Cells

    Science.gov (United States)

    Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Hepp, Aloysius F.

    2001-01-01

    The NASA Glenn Research Center has been investigating the synthesis of quantum dots of CdSe and CuInS2 for use in intermediate-bandgap solar cells. Using quantum dots in a solar cell to create an intermediate band will allow the harvesting of a much larger portion of the available solar spectrum. Theoretical studies predict a potential efficiency of 63.2 percent, which is approximately a factor of 2 better than any state-of-the-art devices available today. This technology is also applicable to thin-film devices--where it offers a potential four-fold increase in power-to-weight ratio over the state of the art. Intermediate-bandgap solar cells require that quantum dots be sandwiched in an intrinsic region between the photovoltaic solar cell's ordinary p- and n-type regions (see the preceding figure). The quantum dots form the intermediate band of discrete states that allow sub-bandgap energies to be absorbed. However, when the current is extracted, it is limited by the bandgap, not the individual photon energies. The energy states of the quantum dot can be controlled by controlling the size of the dot. Ironically, the ground-state energy levels are inversely proportional to the size of the quantum dots. We have prepared a variety of quantum dots using the typical organometallic synthesis routes pioneered by Ba Wendi et al., in the early 1990's. The most studied quantum dots prepared by this method have been of CdSe. To produce these dots, researchers inject a syringe of the desired organometallic precursors into heated triocytlphosphine oxide (TOPO) that has been vigorously stirred under an inert atmosphere (see the following figure). The solution immediately begins to change from colorless to yellow, then orange and red/brown, as the quantum dots increase in size. When the desired size is reached, the heat is removed from the flask. Quantum dots of different sizes can be identified by placing them under a "black light" and observing the various color differences in

  16. A study on socio-demographic profile and feasibility of DOTS provider registered under RNTCP in Varanasi district Uttar Pradesh

    Directory of Open Access Journals (Sweden)

    Mohd. Afzalul Haque

    2014-03-01

    Full Text Available Introduction: Tuberculosis is a major chronic disorder affecting the larger population more than any other disease in the country. DOTS was introduced in India in 1993 as part of the Revised National Tuberculosis Programme (RNTCP following a review of India’s National Tuberculosis Programme (NTP a year earlier (1 .Patient satisfaction is an important parameter for assessing the quality of patient care services. There is need to assess the health care provider regarding the consumer satisfaction as often as possible, this paper summarizes our experience about role of DOTS provider in the management of TB patient in rural population of Varanasi districts Utter Pradesh. Objective: (1 To assess the perception of registered tuberculosis patients regarding DOTS provider for the treatment of tuberculosis. (2 To assess the accessibility, acceptability & availability of community DOTS provider. Design: A longitudinal study. Setting: Three microscopic centre of Cholapur Tuberculosis unit of Varanasi districts. Methods: Registered patients were interviewed twice: once in the beginning and another at the completion of the treatment or after the permanent discontinuation of the treatment. Patients were interviewed for their socio-demographic profiles, opinion about DOTS and its providers. Side effects experienced and action taken etc. Data was collected on a semi-structured, pre-tested questionnaire. DOTS providers were interviewed and treatment cards analyzed for any interruption of treatment and action taken. Data was collected from 1st June 2004 to 31th June 2005 till the completion of the regimen. Results: Majority of DOTS providers were young males (82.7% of 26 years to 40 years, while the representation of females was only 5 (17.3%. Almost more than 80% of the patients started their treatment within 1-10 days. For majority of cases (83% the distance of DOTS provider from patient’s house was within 1 km. Mean time spent to go to DOTS provider was 27

  17. Person-centred care in nursing documentation.

    LENUS (Irish Health Repository)

    Broderick, Margaret C

    2012-12-07

    BACKGROUND: Documentation is an essential part of nursing. It provides evidence that care has been carried out and contains important information to enhance the quality and continuity of care. Person-centred care (PCC) is an approach to care that is underpinned by mutual respect and the development of a therapeutic relationship between the patient and nurse. It is a core principle in standards for residential care settings for older people and is beneficial for both patients and staff (International Practice Development in Nursing and Healthcare, Chichester, Blackwell, 2008 and The Implementation of a Model of Person-Centred Practice in Older Person Settings, Dublin, Health Service Executive, 2010a). However, the literature suggests a lack of person-centredness within nursing documentation (International Journal of Older People Nursing 2, 2007, 263 and The Implementation of a Model of Person-Centred Practice in Older Person Settings, Dublin, Health Service Executive, 2010a). AIMS AND OBJECTIVES: To explore nursing documentation in long-term care, to determine whether it reflected a person-centred approach to care and to describe aspects of PCC as they appeared in nursing records. METHOD: A qualitative descriptive study using the PCN framework (Person-centred Nursing; Theory and Practice, Oxford, Wiley-Blackwell, 2010) as the context through which nursing assessments and care plans were explored. RESULTS: Findings indicated that many nursing records were incomplete, and information regarding psychosocial aspects of care was infrequent. There was evidence that nurses engaged with residents and worked with their beliefs and values. However, nursing documentation was not completed in consultation with the patient, and there was little to suggest that patients were involved in decisions relating to their care. IMPLICATIONS FOR PRACTICE: The structure of nursing documentation can be a major obstacle to the recording of PCC and appropriate care planning. Documentation

  18. Quantum dot heterojunction solar cells: the mechanism of device operation and impacts of quantum dot oxidation

    OpenAIRE

    Ihly, Rachelle

    2014-01-01

    This thesis explores the understanding of the chemistry and physics of colloidal quantum dots for practical solar energy photoconversion. Solar cell devices that make use of PbS quantum dots generally rely on constant and unchanged optical properties such that band gap energies remain tuned within the device. The design and development of unique experiments to ascertain mechanisms of optical band gap shifts occurring in PbS quantum dot thin-films exposed to air are discussed. The systematic s...

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

    Directory of Open Access Journals (Sweden)

    Candasamy Mayuren

    2010-10-01

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

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

    Directory of Open Access Journals (Sweden)

    Candasamy Mayuren.

    2010-01-01

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

  1. FINAL REPORT - Mechanisms of CCl4 Retention and Slow Release in Model Porous Solids and Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Reid C. Miller; Dr. Brent M. Peyton

    2006-12-11

    A magnetically coupled microbalance system has been used to measure adsorption and desorption isotherms and rates of desorption for carbon tetrachloride on dry prepared porous silica particles with narrow pore size distributions in the mesoporous range. Pore size distributions estimated from the carbon tetrachloride isotherms were found to be in close agreement with those determined using standard low temperature nitrogen adsorption. Three different types of particles were studied, with average pore diameters of 2.7 nm, 4.6 nm, and 5.9 nm. Prior to desorption rate studies, evacuated particulate samples were charged with volatile organic vapor at pressures sufficient to fill all mesopores with condensed fluid. Desorption rates into dry flowing helium were determined at 25 °C and atmospheric pressure, using the microbalance system combined with chromatographic analysis of the exit helium stream. Initial rates were found to decrease significantly, as mass adsorbed decreased. This residual mass was desorbing at such a low rate, that it can be considered a migration resistant fraction of the original mass adsorbed. Attempts to remove this residual mass at higher temperatures were partially successful; however, differences between the microbalance and gas chromatograph responses leave open uncertainty about whether the residual mass was pure carbon tetrachloride. To date, attempts at analysis of the residual mass using solvent extraction have not removed completely this uncertainty. For particles prepared using the same template surfactant, but with different average pore sizes, desorption rates were higher for the larger-pore particles, with correspondingly lower residual mass. Particles prepared with another template surfactant did not follow this pattern, exhibiting intermediate desorption rates and slightly lower residual mass, even though these particles had the smallest pores. These particles exhibited desorption isotherm behavior characteristic of larger pores connected by smaller openings. Except for peculiar behavior in the very early part of desorption experiments for one type of particles, the carbon tetrachloride desorption curves could be fit by a two-part model, employing a diffusion model for the bulk of the desorption, followed by a deactivation model as the mass adsorbed approached residual values. Simultaneous microbalance and gas chromatograph measurements were used to determine carbon tetrachloride and water desorption rates from silica particles initially containing both volatile components. Varying water to carbon tetrachloride ratios were loaded on two types of particles with different pore sizes, with water always loaded first. With water on the particles, pore volumes were significantly reduced. When compared at the same mass adsorbed values, total desorption rates consistently decreased with increasing water content. Total residual mass was found to be a strong function of initial water content, increasing nonlinearly from as initial water content increased from 0 % to 100 %. As expected, during the first few hours of all desorption rate experiments, the rates of carbon tetrachloride desorption were larger than for water. At low initial water contents, total desorption rates were controlled throughout by the carbon tetrachloride rates. For higher water contents, the water rates became larger than the carbon tetrachloride rates for at least some period of intermediate times, after the bulk of the carbon tetrachloride had been desorbed. Although the compositions of the residual mass have not been independently measured, there is evidence that both components were retained, but that water was the major component when there was significant initial water on the particles.

  2. A novel fluorinated stilbene exerts hepatoprotective properties in CCl(4)-induced acute liver damage.

    Science.gov (United States)

    Rivera, Horacio; Morales-Ríos, Martha S; Bautista, Wendy; Shibayama, Mineko; Tsutsumi, Víctor; Muriel, Pablo; Pérez-Álvarez, Víctor

    2011-10-01

    There has been a recently increase in the development of novel stilbene-based compounds with in vitro anti-inflamatory properties. For this study, we synthesized and evaluated the anti-inflammatory properties of 2 fluorinated stilbenes on carbon tetrachloride (CCl₄)-induced acute liver damage. To achieve this, CCl₄ (4 g·kg(-1), per os) was administered to male Wistar rats, followed by either 2-fluoro-4'-methoxystilbene (FME) or 2,3-difluoro-4'-methoxystilbene (DFME) (10 mg·kg(-1), per os). We found that although both of the latter compounds prevented cholestatic damage (γ-glutamyl transpeptidase activity), only DFME showed partial but consistent results in the prevention of necrosis, as assessed by both alanine aminotransferase activity and histological analysis. Since inflammatory responses are mediated by cytokines, mainly tumour necrosis factor α (TNF-α), we used the Western blot technique to determine the action of FME and DFME on the expression level of this cytokine. The observed increase in the level of TNF-α caused by CCl₄ administration was only prevented by treatment with DFME, in agreement with our biochemical findings. This result was confirmed by measuring interleukin-6 (IL-6) levels, since the expression of this protein depends on the level of TNF-α. In this case, DFME completely blocked the CCl₄-induced increase of IL-6. Our results suggest that DFME possesses greater anti-inflammatory properties in vivo than FME. DFME constitutes a possible therapeutic agent for liver disease and could serve as a template for structure optimization.

  3. Tailoring Magnetism in Quantum Dots

    Science.gov (United States)

    Zutic, Igor; Abolfath, Ramin; Hawrylak, Pawel

    2007-03-01

    We study magnetism in magnetically doped quantum dots as a function of particle numbers, temperature, confining potential, and the strength of Coulomb interaction screening. We show that magnetism can be tailored by controlling the electron-electron Coulomb interaction, even without changing the number of particles. The interplay of strong Coulomb interactions and quantum confinement leads to enhanced inhomogeneous magnetization which persists at substantially higher temperatures than in the non-interacting case or in the bulk-like dilute magnetic semiconductors. We predict a series of electronic spin transitions which arise from the competition between the many-body gap and magnetic thermal fluctuations. Cond-mat/0612489. [1] R. Abolfath, P. Hawrylak, I. Zuti'c, preprint.

  4. Large quantum dots with small oscillator strength

    DEFF Research Database (Denmark)

    Stobbe, Søren; Schlereth, T.W.; Höfling, S.

    2010-01-01

    We have measured the oscillator strength and quantum efficiency of excitons confined in large InGaAs quantum dots by recording the spontaneous emission decay rate while systematically varying the distance between the quantum dots and a semiconductor-air interface. The size of the quantum dots...... is measured by in-plane transmission electron microscopy and we find average in-plane diameters of 40 nm. We have calculated the oscillator strength of excitons of that size assuming a quantum-dot confinement given by a parabolic in-plane potential and a hard-wall vertical potential and predict a very large...... oscillator strength due to Coulomb effects. This is in stark contrast to the measured oscillator strength, which turns out to be so small that it can be described by excitons in the strong confinement regime. We attribute these findings to exciton localization in local potential minima arising from alloy...

  5. Ge Quantum Dot Infrared Imaging Camera Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Luna Innovations Incorporated proposes to develop a high performance Ge quantum dots-based infrared (IR) imaging camera on Si substrate. The high sensitivity, large...

  6. Measurement of Eccentricity of the Centre of Mass from the Geometric Centre of a Sphere

    Institute of Scientific and Technical Information of China (English)

    郭俊起; 胡忠坤; 顾邦明; 罗俊

    2004-01-01

    The eccentricity of the centre of mass from the geometric centre of a spherical attracting mass in determining the Newtonian gravitational constant G is tested by means of an electronic balance. The experimental result shows that the eccentricity of the sample is about 0.31 μm with uncertainty of 0.05 μm. Two density distribution models are discussed to estimate the uncertainty to G by the eccentricities of the attracting masses.

  7. Treatment Outcomes of Patients Placed on Treatment Under Directly Observed Therapy Short-Course (Dots)

    Science.gov (United States)

    Kaur, Gurpreet; Goel, N.K.; Kumar, Dinesh; Janmeja, A.K.; Swami, H.M.; Kalia, Meenu

    2008-01-01

    Background: Tuberculosis continues to be a pressing health problem in India. The Revised National Tuberculosis Programme (RNTCP), an application of Directly Observed Treatment Short-course (DOTS) in India, launched in 1997 needs continuous evaluation. Objective: To study the outcomes of treatment among the patients put on DOTS under RNTCP in Chandigarh, UT. Material & Methods: A Longitudinal study was conducted during 2004-2005 in 13 Microscopic centres (MC's) spread over 2 Tuberculosis Units (TU's) under District Tuberculosis Centre (DTC) in Union Territory (UT), Chandigarh. A sample of 265 respondents, selected by two-stage stratified random sampling technique, was recruited in the study cohort. Data analysis was done using SPSS-10 statistical software package. Results: For Category I and Category II patients, the Success rate was 98.6% and 90.4% respectively. The overall default rate was 1.1% and failure rate was 2.6%. For re-treatment cases, failure rate was higher i.e. 5.8%. The sputum conversion rate among the new smear positive cases was 93.8% at 3 months of treatment. For the re-treatment cases, spu-tum conversion rate at 3 months was 94.1%. Conclusion: The study concludes that RNTCP is running successfully in UT Chandigarh, having high success rate and low default rate. The reasons for high failure rate should be explored in depth. PMID:20165654

  8. Treatment outcomes of patients placed on treatment under directly observed therapy short-course (DOTS

    Directory of Open Access Journals (Sweden)

    Kaur Gurpreet

    2008-01-01

    Full Text Available Background : Tuberculosis continues to be a pressing health problem in India. The Revised National Tuberculosis Programme (RNTCP, an application of Directly Observed Treatment Short-course (DOTS in India, launched in 1997 needs contin-uous evaluation. Objective : To study the outcomes of treatment among the patients put on DOTS under RNTCP in Chandigarh, UT. Material & Methods : A Longitudi-nal study was conducted during 2004-2005 in 13 Microscopic centres (MC′s spread over 2 Tuberculosis Units (TU′s under District Tuberculosis Centre (DTC in Union Territory (UT, Chandigarh. A sample of 265 respondents, selected by two-stage stratified random sampling technique, was recruited in the study cohort. Data analysis was done using SPSS-10 statistical software package. Results : For Category I and Category II patients, the Success rate was 98.6% and 90.4% respectively. The overall default rate was 1.1% and failure rate was 2.6%. For re-treatment cases, failure rate was higher i.e. 5.8%. The sputum conversion rate among the new smear positive cases was 93.8% at 3 months of treatment. For the re-treatment cases, spu-tum conversion rate at 3 months was 94.1%. Conclusion : The study concludes that RNTCP is running successfully in UT Chandigarh, having high success rate and low default rate. The reasons for high failure rate should be explored in depth.

  9. Effects of unstratified and centre-stratified randomization in multi-centre clinical trials.

    Science.gov (United States)

    Anisimov, Vladimir V

    2011-01-01

    This paper deals with the analysis of randomization effects in multi-centre clinical trials. The two randomization schemes most often used in clinical trials are considered: unstratified and centre-stratified block-permuted randomization. The prediction of the number of patients randomized to different treatment arms in different regions during the recruitment period accounting for the stochastic nature of the recruitment and effects of multiple centres is investigated. A new analytic approach using a Poisson-gamma patient recruitment model (patients arrive at different centres according to Poisson processes with rates sampled from a gamma distributed population) and its further extensions is proposed. Closed-form expressions for corresponding distributions of the predicted number of the patients randomized in different regions are derived. In the case of two treatments, the properties of the total imbalance in the number of patients on treatment arms caused by using centre-stratified randomization are investigated and for a large number of centres a normal approximation of imbalance is proved. The impact of imbalance on the power of the study is considered. It is shown that the loss of statistical power is practically negligible and can be compensated by a minor increase in sample size. The influence of patient dropout is also investigated. The impact of randomization on predicted drug supply overage is discussed.

  10. Start Shift of Individual Quantum Dots

    Science.gov (United States)

    1999-06-18

    We will here describe the results of the influence of electric field on InP quantum dots embedded in GalnP, lattice matched to GaAs. Experimental...details The sample we used was grown by metal-organic vapour phase epitaxy, and contained InP quantum dots in GanP, lattice matched to GaAs (n-type

  11. Exciton in type-II quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Sierra-Ortega, J; Escorcia, R A [Universidad del Magdalena, A. A. 731, Santa Marta (Colombia); Mikhailov, I D, E-mail: jsierraortega@gmail.co [Universidad Industrial de Santander, A. A. 678, Bucaramanga (Colombia)

    2009-05-01

    We study the quantum-size effect and the influence of the external magnetic field on the exciton ground state energy in the type-II InP quantum disk, lens and pyramid deposited on a wetting layer and embedded in a GaInP matrix. We show that the charge distribution over and below quantum dot and wetting layer induced by trapped exciton strongly depends on the quantum dot morphology and the strength of the magnetic field.

  12. Random Feature Maps for Dot Product Kernels

    OpenAIRE

    Kar, Purushottam; Karnick, Harish

    2012-01-01

    Approximating non-linear kernels using feature maps has gained a lot of interest in recent years due to applications in reducing training and testing times of SVM classifiers and other kernel based learning algorithms. We extend this line of work and present low distortion embeddings for dot product kernels into linear Euclidean spaces. We base our results on a classical result in harmonic analysis characterizing all dot product kernels and use it to define randomized feature maps into explic...

  13. Chaotic quantum dots with strongly correlated electrons

    OpenAIRE

    Shankar, R.

    2007-01-01

    Quantum dots pose a problem where one must confront three obstacles: randomness, interactions and finite size. Yet it is this confluence that allows one to make some theoretical advances by invoking three theoretical tools: Random Matrix theory (RMT), the Renormalization Group (RG) and the 1/N expansion. Here the reader is introduced to these techniques and shown how they may be combined to answer a set of questions pertaining to quantum dots

  14. Dot-dye-immunoassay for the diagnosis of schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Teles Rabello

    1992-06-01

    Full Text Available A new serological assay dot-dye-immunoassay (dot-DIA was evaluated for the diagnosis of schistosomiasis mansoni. This method consist of four steps: (a biding of antigens to a nitrocellulose membrane (NC; (b blocking of free sites of the NC; (c incubation in specific primary antibody; (d detection of primary antibody reactivity by color development using second antibody coupled to textile dyes. Sera from 82 individuals, 61 with Schistosoma mansoni eggs in the stool and 21 stool negative were tested by ELISA, dot-ELISA, and dotDIA. A high level of agreement between the methods tested was observed for all sera tested: ELISA x dot-ELISA: 95.1%, ELISA x dot-DIA: 92.7% and dot-ELISA x dot-DIA: 97.6%. In this study, dot-DIA proved to be a feasible, sensitive, rapid and practical test for the diagnosis of shcistosomiasis.

  15. Quantum-dot-in-perovskite solids

    KAUST Repository

    Ning, Zhijun

    2015-07-15

    © 2015 Macmillan Publishers Limited. All rights reserved. Heteroepitaxy - atomically aligned growth of a crystalline film atop a different crystalline substrate - is the basis of electrically driven lasers, multijunction solar cells, and blue-light-emitting diodes. Crystalline coherence is preserved even when atomic identity is modulated, a fact that is the critical enabler of quantum wells, wires, and dots. The interfacial quality achieved as a result of heteroepitaxial growth allows new combinations of materials with complementary properties, which enables the design and realization of functionalities that are not available in the single-phase constituents. Here we show that organohalide perovskites and preformed colloidal quantum dots, combined in the solution phase, produce epitaxially aligned \\'dots-in-a-matrix\\' crystals. Using transmission electron microscopy and electron diffraction, we reveal heterocrystals as large as about 60 nanometres and containing at least 20 mutually aligned dots that inherit the crystalline orientation of the perovskite matrix. The heterocrystals exhibit remarkable optoelectronic properties that are traceable to their atom-scale crystalline coherence: photoelectrons and holes generated in the larger-bandgap perovskites are transferred with 80% efficiency to become excitons in the quantum dot nanocrystals, which exploit the excellent photocarrier diffusion of perovskites to produce bright-light emission from infrared-bandgap quantum-tuned materials. By combining the electrical transport properties of the perovskite matrix with the high radiative efficiency of the quantum dots, we engineer a new platform to advance solution-processed infrared optoelectronics.

  16. Coherent transport through interacting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Hiltscher, Bastian

    2012-10-05

    The present thesis is composed of four different works. All deal with coherent transport through interacting quantum dots, which are tunnel-coupled to external leads. There a two main motivations for the use of quantum dots. First, they are an ideal device to study the influence of strong Coulomb repulsion, and second, their discrete energy levels can easily be tuned by external gate electrodes to create different transport regimes. The expression of coherence includes a very wide range of physical correlations and, therefore, the four works are basically independent of each other. Before motivating and introducing the different works in more detail, we remark that in all works a diagrammatic real-time perturbation theory is used. The fermionic degrees of freedom of the leads are traced out and the elements of the resulting reduced density matrix can be treated explicitly by means of a generalized master equation. How this equation is solved, depends on the details of the problem under consideration. In the first of the four works adiabatic pumping through an Aharonov-Bohm interferometer with a quantum dot embedded in each of the two arms is studied. In adiabatic pumping transport is generated by varying two system parameters periodically in time. We consider the two dot levels to be these two pumping parameters. Since they are located in different arms of the interferometer, pumping is a quantum mechanical effect purely relying on coherent superpositions of the dot states. It is very challenging to identify a quantum pumping mechanism in experiments, because a capacitive coupling of the gate electrodes to the leads may yield an undesired AC bias voltage, which is rectified by a time dependent conductance. Therefore, distinguishing features of these two transport mechanisms are required. We find that the dependence on the magnetic field is the key feature. While the pumped charge is an odd function of the magnetic flux, the rectified current is even, at least in

  17. Danish Polymer Centre annual report 2001

    DEFF Research Database (Denmark)

    Hassager, O.; Hvilsted, S.; Mortensen, Kell

    The centre is a collaboration between the Risø National Laboratory and the Technical University of Denmark (DTU). At the DTU the Department of Chemical Engineering and the Department of Manufacturing Engineering and Management participate in the centre.From 2001 the Polymer Department at Risø coo....... The Annual Report for 2001 represents therefore the first report from a period in which the new facilitieshave been utilized to full advantage....... coordinates the activities at Risø From the outset it was considered important with common laboratories to obtain the full effect of the collaboration between the two departments at the DTU and Risø NationalLaboratory. In 2001 new laboratories for polymer research and education were established at the DTU...

  18. Patient-centred Prevention among PAD Patients

    DEFF Research Database (Denmark)

    Pii, Kathrine Hoffmann

    2014-01-01

    Intro: This paper discusses a central professional dilemma in patient-centred education: on one hand the concern for ensuring patients autonomy and right to make their own decisions regarding their treatment and, on the other hand, a concern for getting patients to make the “right” decisions......-centredness is thus promoted as a way to organize health more effectively (in terms of cost and treatment outcomes) and as a way to ensure patients’ autonomy and fundamental right to make their own decisions regarding their treatment. Critical voices within social and nursing theory have however argued...... of a patient-centred prevention programme aimed at PAD patients, which includes medical treatment as well as individual nurse-led lifestyle-oriented conversations (inspired by psychological theory and methods such as Motivational Interviewing). Method: The findings are based on four months ethnographic field...

  19. JOB CENTRE FOR DOMESTIC STAFF IN SWITZERLAND

    CERN Multimedia

    Relations with the Host States Service; http://www.cern.ch/relations/

    2001-01-01

    The Permanent mission of Switzerland to the International Organisations in Geneva has informed CERN that the Geneva Welcome Centre has set up an employment registration desk for the domestic staff of international civil servants. The aim of this pilot project is, on the one hand, to help international civil servants find domestic staff and, on the other hand, to help domestic staff holding an 'F'-type carte de légitimation find employment within 30 days after the expiry of a contract. For more information, please contact the Geneva Welcome Centre, La Pastorale, 106, route de Ferney, Case postale 103, 1211 Genève 20, tel. (+41.22) 918 02 70, fax (+41.22) 918 02 79), http://geneva-international.org/Welcome.E.html.

  20. Institutional profile: the London Centre for Nanotechnology.

    Science.gov (United States)

    Weston, David; Bontoux, Thierry

    2009-12-01

    Located in the London neighborhoods of Bloomsbury and South Kensington, the London Centre for Nanotechnology is a UK-based multidisciplinary research center that operates at the forefront of science and technology. It is a joint venture between two of the world's leading institutions, UCL and Imperial College London, uniting their strong capabilities in the disciplines that underpin nanotechnology: engineering, the physical sciences and biomedicine. The London Centre for Nanotechnology has a unique operating model that accesses and focuses the combined skills of the Departments of Chemistry, Physics, Materials, Medicine, Electrical and Electronic Engineering, Mechanical Engineering, Chemical Engineering, Biochemical Engineering and Earth Sciences across the two universities. It aims to provide the nanoscience and nanotechnology required to solve major problems in healthcare, information processing, energy and the environment.

  1. Emergency Centre Organization and Automated Triage System

    CERN Document Server

    Golding, Dan; Marwala, Tshilidzi

    2008-01-01

    The excessive rate of patients arriving at accident and emergency centres is a major problem facing South African hospitals. Patients are prioritized for medical care through a triage process. Manual systems allow for inconsistency and error. This paper proposes a novel system to automate accident and emergency centre triage and uses this triage score along with an artificial intelligence estimate of patient-doctor time to optimize the queue order. A fuzzy inference system is employed to triage patients and a similar system estimates the time but adapts continuously through fuzzy Q-learning. The optimal queue order is found using a novel procedure based on genetic algorithms. These components are integrated in a simple graphical user interface. Live tests could not be performed but simulations reveal that the average waiting time can be reduced by 48 minutes and priority is given to urgent patients

  2. Achieving competences in patient-centred care

    DEFF Research Database (Denmark)

    Lomborg, Kirsten; Nielsen, Else Skånning; Jensen, Annesofie Lunde

    2011-01-01

    Aim: To document the efficacy of a training programme in patient-centred care in which the nursing staff was trained to involve chronic obstructive pulmonary patients in assisted personal body care (APBC). The objectives were to describe the programme and uncover the outcomes. Background: Chronic...... obstructive pulmonary patients suffer from breathlessness and may need comprehensive assistance with personal body care. The patients’ wellbeing may be improved and their integrity safeguarded if nurses are able to involve the patients in accordance with their illness conditions and personal preferences....... The training was time-consuming. Conclusion: A comprehensive training programme can improve nursing competences to action patient-centred and involve severely ill respiratory patients in APBC. Further studies are needed to investigate the efficacy from the patients’ perspective. Relevance to clinical practice...

  3. It's all change at the Computer Centre

    CERN Multimedia

    Laëtitia Pedroso

    2011-01-01

    The IT and EN Departments are modernising the infrastructure of the Computer Centre to improve the conditions in which the equipment has to operate and to increase capacity. The construction work has already begun and is due to be completed in October 2012.   Every year CERN experiences around ten power cuts lasting from less than a second to several hours. In most cases the two protection systems - the UPS* and the diesel generators – are able to ensure that the operation of the Computer Centre is not affected. As Vincent Doré, the project leader for the IT Department, and Paul Pepinster, the EN Department's technical coordinator in charge of modernising the infrastructure, explains: "Building 513 has two types of computing facilities – the "non-critical" ones, such as the servers for "off-line" computing, which have UPS systems ensuring that they can operate for 10 minutes after a power cut, and the "critical&...

  4. [The development process of colon cancer centres].

    Science.gov (United States)

    Sahm, M; Wesselmann, S; Kube, R; Schöffel, N; Pross, M; Lippert, H; Kahl, S

    2013-02-01

    Colon carcinomas are the most common malignant tumours in the Western world. Important findings about the overall quality of medical care have been reported in multi-centre observational studies. A quality enhancement of therapeutic care can be achieved by an additional increase in diagnostic and therapeutic measures in the interdisciplinary setting. The development of colon cancer centres improves the chance to objectively observe the results of medical care induced by the development of an interdisciplinary and cross-sectoral unit that includes a comprehensive medical care for patients. The implementation of the current medical findings based on evidence in clinical routine, the inspection of the usage of guidelines by external specialists as part of an audit and the continuous correction of analysed deficits in the course of treatment guarantee a continuous improvement of service.

  5. Birth of a science centre. Italian phenomenology

    Directory of Open Access Journals (Sweden)

    Paola Rodari

    2006-06-01

    Full Text Available In May 2004 the Balì Museum, Planetarium and interactive science museum, was opened to the public in Italy: 35 hands-on exhibits designed according to the interactive tradition of the Exploratorium in San Francisco, an astronomic observatory for educational activities, a Planetarium with 70 places. With a total investment of about three million euros, about two thirds of which were spent on restructuring the splendid eighteenth-century villa in which it is housed, the undertaking may be considered a small one in comparison with other European science centres. Three million euros: perhaps enough to cover the cost of only the splendid circular access ramp to the brand-new Cosmocaixa in Barcelona, an investment of one hundred million euros. But the interesting aspect of the story of the Balì Museum (but also of other Italian stories, as we shall see lies in the fact that this lively and advanced science centre stands in the bucolic region of the Marches, next to a small town of only 800 inhabitants (Saltara, in the Province of Pesaro and Urbino, in a municipal territory that has a total of 5000. Whereas in Italy the projects for science centres comparable with the Catalan one, for example projects for Rome and Turin, never get off the ground, smaller ones are opening in small and medium-sized towns: why is this? And what does the unusual location of the centres entail for science communication in Italy? This Focus does not claim to tell the whole truth about Italian interactive museums, but it does offer some phenomenological cues to open a debate on the cultural, economic and political premises that favour their lives.

  6. User-Centred Design Using Gamestorming.

    Science.gov (United States)

    Currie, Leanne

    2016-01-01

    User-centered design (UX) is becoming a standard in software engineering and has tremendous potential in healthcare. The purpose of this tutorial will be to demonstrate and provide participants with practice in user-centred design methods that involve 'Gamestorming', a form of brainstorming where 'the rules of life are temporarily suspended'. Participants will learn and apply gamestorming methods including persona development via empathy mapping and methods to translate artefacts derived from participatory design sessions into functional and design requirements.

  7. CMS Centres Worldwide - a New Collaborative Infrastructure

    CERN Document Server

    Taylor, Lucas

    2011-01-01

    Webcasts, and generic Web tools such as CMS-TV for broadcasting live monitoring and outreach information. Being Web-based and experiment-independent, these systems could easily be extended to other organizations. We describe the experiences of using CMS Centres Worldwide in the CMS data-taking operations as well as for major media events with several hundred TV channels, radio stations, and many more press journalists simultaneously around the world.

  8. Enhancing Safety at Airline Operations Control Centre

    Directory of Open Access Journals (Sweden)

    Lukáš Řasa

    2015-04-01

    Full Text Available In recent years a new term of Safety Management System (SMS has been introduced into aviation legislation. This system is being adopted by airline operators. One of the groundbased actors of everyday operations is Operations Control Centre (OCC. The goal of this article has been to identify and assess risks and dangers which occur at OCC and create a template for OCC implementation into SMS.

  9. Training science centre Explainers. The Techniquest experience

    Directory of Open Access Journals (Sweden)

    Colin Johnson

    2005-12-01

    Full Text Available Techniquest was established in 1986, and in 1995 moved to its current premises at Cardiff Bay, South Wales. This was the first purpose-built science centre in the UK. It receives around 200,000 visitors every year to its exhibition, and to its programmes for schools and public audiences in the theatre, laboratory, discovery room and planetarium. The author joined the Techniquest project in 1985, became a staff member in 1990 and was the Chief Executive from 1997 until his retirement in 2004. Techniquest has three “out-stations” in Wales, and is responsible for the supply and maintenance of exhibits to the Look Out Discovery Centre in Bracknell, England. There is a Techniquest gallery at the Lisbon Pavilhão do Conhecimento - Ciência Viva, and a traveling exhibition, SciQuest, in South Africa which was also supplied by Techniquest. All these centres rely on the effective intervention of “Explainers” (at Techniquest we call them “Helpers” to provide the best possible experience for visitors. At its most demanding, the tasks of an Explainer are varied and intensive, yet there may be times when the duties are mundane or even dull. When you rely on people to act as both hosts and housekeepers, to provide both support and stimulus, and to be both welcoming and watchful, you are asking a great deal. This article raises some of the issues concerned with the recruitment and retention of Explainers, their training and management, and the way in which their role is recognized and valued by the science centre as a whole.

  10. Bismuth centred magnetic perovskite: A projected multiferroic

    Energy Technology Data Exchange (ETDEWEB)

    Kundu, Asish K., E-mail: asish.k@gmail.com [Discipline of Physics, Indian Institute of Information Technology, Design and Manufacturing, Dumna Airport Road, Jabalpur 482005 (India); Seikh, Md. Motin [Department of Chemistry, Visva-Bharati University, Santiniketan, West Bengal 731235 (India); Nautiyal, Pranjal [Discipline of Mechanical Engineering, Indian Institute of Information Technology, Design and Manufacturing, Dumna Airport Road, Jabalpur 482005 (India)

    2015-03-15

    In recent time substantial attention has been initiated to understand the physics behind multiferroism and to design new multiferroic materials. BiMnO{sub 3} and BiFeO{sub 3} are the well-studied Bi-centred multiferroic oxides. BiMnO{sub 3} is a ferromagnetic–ferroelectric (metastable) phase and require drastic conditions to synthesize. However, lanthanum substituted BiMnO{sub 3} phases stabilized at ambient pressure. It is thus of major importance to increase the number of ferromagnetic perovskites with Bi cations that could be designed under ambient conditions. In this article, we have presented an up to date report of investigations on Bi-centred magnetic perovskites, a prospective material for multiferroic application. Central focus is concentrated on La{sub 0.5}Bi{sub 0.5}MnO{sub 3} perovskite with various substitutions at different levels. A few of these perovskites are found to be of practical importance e.g. La{sub 0.5}Bi{sub 0.5}Mn{sub 0.67}Co{sub 0.33}O{sub 3} with high dielectric permittivity coupled with ferromagnetism. A comprehensive analysis of different physical functionalities and their interrelation for a wide range of compositions of these Bi-centred perovskites is presented. It has been found that the complex magnetic behaviour originates from mixed valence metal ions. The ferroelectricity is associated with the 6s{sup 2} lone pair of Bi{sup 3+} cations. The magnetic ground state influences the dielectric properties reflecting the multiferroism in a single material. - Highlights: • Multiferroics have attracted increasing attention due to their possible device applications. • Bismuth centred magnetic perovskite is one kind of such promising multiferroic materials. • Ferromagnetic Bi-perovskites, which are synthesized at ambient conditions, have been discussed.

  11. Upcoming opening of CERN's new Mobility Centre

    CERN Multimedia

    2016-01-01

    On 29 February, CERN’s brand new Mobility Centre opened in the Globe car park. The Centre has been created to cater to the transport needs of everyone at CERN, to simplify procedures and to centralise all the transport services on offer: the rental of CERN bikes and cars, the CERN car-sharing scheme and SIXT car rental.   From 29 February onwards, the Mobility Centre in the Globe car park will be the place to go for all your duty travel needs: rental of CERN cars (with or without the CERN logo), SIXT car rental, CERN bike rental, distribution of cards allowing the use of CERN’s self-service bike- and car-sharing schemes. That same day, the premises currently housing the Car Pool in Building 130 will become the CERN garage, responsible for: upkeep and repairs on CERN bikes, minor maintenance work on CERN vehicles (e.g. replacing windscreen wipers, bulbs and fuses, refilling windscreen washer fluid, pumping up tyres, etc.), arranging and following up the repair and maintenan...

  12. Bismuth centred magnetic perovskite: A projected multiferroic

    Science.gov (United States)

    Kundu, Asish K.; Seikh, Md. Motin; Nautiyal, Pranjal

    2015-03-01

    In recent time substantial attention has been initiated to understand the physics behind multiferroism and to design new multiferroic materials. BiMnO3 and BiFeO3 are the well-studied Bi-centred multiferroic oxides. BiMnO3 is a ferromagnetic-ferroelectric (metastable) phase and require drastic conditions to synthesize. However, lanthanum substituted BiMnO3 phases stabilized at ambient pressure. It is thus of major importance to increase the number of ferromagnetic perovskites with Bi cations that could be designed under ambient conditions. In this article, we have presented an up to date report of investigations on Bi-centred magnetic perovskites, a prospective material for multiferroic application. Central focus is concentrated on La0.5Bi0.5MnO3 perovskite with various substitutions at different levels. A few of these perovskites are found to be of practical importance e.g. La0.5Bi0.5Mn0.67Co0.33O3 with high dielectric permittivity coupled with ferromagnetism. A comprehensive analysis of different physical functionalities and their interrelation for a wide range of compositions of these Bi-centred perovskites is presented. It has been found that the complex magnetic behaviour originates from mixed valence metal ions. The ferroelectricity is associated with the 6s2 lone pair of Bi3+ cations. The magnetic ground state influences the dielectric properties reflecting the multiferroism in a single material.

  13. Energy Efficiency Improvements Using DC in Data Centres

    OpenAIRE

    Bergqvist, Sofia

    2011-01-01

    The installed power usage in a data centre will often amount to several megawatts (MW). Thetotal power consumption of the data centres in the world is comparable to that of the airtraffic. The high energy costs and carbon dioxide emissions resulting from the operation of adata centre call for alternative, more efficient, solutions for the power supply design. Oneproposed solution to decrease the energy usage is to use a direct current power supply (DCUPS) for all the servers in the data centr...

  14. Optimal catchment area and primary PCI centre volume revisited

    DEFF Research Database (Denmark)

    Schoos, Mikkel Malby; Pedersen, Frants; Holmvang, Lene;

    2015-01-01

    AIMS: The currently stated optimal catchment population for a pPCI centre is 300,000-1,100,000, resulting in 200-800 procedures/year. pPCI centres are increasing in number even within small geographic areas. We describe the organisation and quality of care after merging two high-volume centres...

  15. Tele-centres as a way of achieving universal access

    DEFF Research Database (Denmark)

    Falch, Morten; Anyimadu, Amos

    2003-01-01

    The success of tele-centres in Ghana is discussed. The tele-centres offer a low cost opportunity to empower local communities in developed and developing countries to meet the challenges of the information society. The tele-centres can also contribute more directly to the supply of non-commercial...

  16. Advancements in the Field of Quantum Dots

    Science.gov (United States)

    Mishra, Sambeet; Tripathy, Pratyasha; Sinha, Swami Prasad.

    2012-08-01

    Quantum dots are defined as very small semiconductor crystals of size varying from nanometer scale to a few micron i.e. so small that they are considered dimensionless and are capable of showing many chemical properties by virtue of which they tend to be lead at one minute and gold at the second minute.Quantum dots house the electrons just the way the electrons would have been present in an atom, by applying a voltage. And therefore they are very judiciously given the name of being called as the artificial atoms. This application of voltage may also lead to the modification of the chemical nature of the material anytime it is desired, resulting in lead at one minute to gold at the other minute. But this method is quite beyond our reach. A quantum dot is basically a semiconductor of very tiny size and this special phenomenon of quantum dot, causes the band of energies to change into discrete energy levels. Band gaps and the related energy depend on the relationship between the size of the crystal and the exciton radius. The height and energy between different energy levels varies inversely with the size of the quantum dot. The smaller the quantum dot, the higher is the energy possessed by it.There are many applications of the quantum dots e.g. they are very wisely applied to:Light emitting diodes: LEDs eg. White LEDs, Photovoltaic devices: solar cells, Memory elements, Biology : =biosensors, imaging, Lasers, Quantum computation, Flat-panel displays, Photodetectors, Life sciences and so on and so forth.The nanometer sized particles are able to display any chosen colour in the entire ultraviolet visible spectrum through a small change in their size or composition.

  17. Submonolayer Quantum Dot Infrared Photodetector

    Science.gov (United States)

    Ting, David Z.; Bandara, Sumith V.; Gunapala, Sarath D.; Chang, Yia-Chang

    2010-01-01

    A method has been developed for inserting submonolayer (SML) quantum dots (QDs) or SML QD stacks, instead of conventional Stranski-Krastanov (S-K) QDs, into the active region of intersubband photodetectors. A typical configuration would be InAs SML QDs embedded in thin layers of GaAs, surrounded by AlGaAs barriers. Here, the GaAs and the AlGaAs have nearly the same lattice constant, while InAs has a larger lattice constant. In QD infrared photodetector, the important quantization directions are in the plane perpendicular to the normal incidence radiation. In-plane quantization is what enables the absorption of normal incidence radiation. The height of the S-K QD controls the positions of the quantized energy levels, but is not critically important to the desired normal incidence absorption properties. The SML QD or SML QD stack configurations give more control of the structure grown, retains normal incidence absorption properties, and decreases the strain build-up to allow thicker active layers for higher quantum efficiency.

  18. Quantum dots as biophotonics tools.

    Science.gov (United States)

    Cesar, Carlos L

    2014-01-01

    This chapter provides a short review of quantum dots (QDs) physics, applications, and perspectives. The main advantage of QDs over bulk semiconductors is the fact that the size became a control parameter to tailor the optical properties of new materials. Size changes the confinement energy which alters the optical properties of the material, such as absorption, refractive index, and emission bands. Therefore, by using QDs one can make several kinds of optical devices. One of these devices transforms electrons into photons to apply them as active optical components in illumination and displays. Other devices enable the transformation of photons into electrons to produce QDs solar cells or photodetectors. At the biomedical interface, the application of QDs, which is the most important aspect in this book, is based on fluorescence, which essentially transforms photons into photons of different wavelengths. This chapter introduces important parameters for QDs' biophotonic applications such as photostability, excitation and emission profiles, and quantum efficiency. We also present the perspectives for the use of QDs in fluorescence lifetime imaging (FLIM) and Förster resonance energy transfer (FRET), so useful in modern microscopy, and how to take advantage of the usually unwanted blinking effect to perform super-resolution microscopy.

  19. Electromechanical transition in quantum dots

    Science.gov (United States)

    Micchi, G.; Avriller, R.; Pistolesi, F.

    2016-09-01

    The strong coupling between electronic transport in a single-level quantum dot and a capacitively coupled nanomechanical oscillator may lead to a transition towards a mechanically bistable and blocked-current state. Its observation is at reach in carbon-nanotube state-of-art experiments. In a recent publication [Phys. Rev. Lett. 115, 206802 (2015), 10.1103/PhysRevLett.115.206802] we have shown that this transition is characterized by pronounced signatures on the oscillator mechanical properties: the susceptibility, the displacement fluctuation spectrum, and the ring-down time. These properties are extracted from transport measurements, however the relation between the mechanical quantities and the electronic signal is not always straightforward. Moreover the dependence of the same quantities on temperature, bias or gate voltage, and external dissipation has not been studied. The purpose of this paper is to fill this gap and provide a detailed description of the transition. Specifically we find (i) the relation between the current-noise and the displacement spectrum; (ii) the peculiar behavior of the gate-voltage dependence of these spectra at the transition; (iii) the robustness of the transition towards the effect of external fluctuations and dissipation.

  20. Quantum dots for terahertz generation

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H C; Aslan, B; Gupta, J A; Wasilewski, Z R; Aers, G C; SpringThorpe, A J; Buchanan, M [Institute for Microstructural Sciences, National Research Council, Ottawa, K1A 0R6 (Canada)], E-mail: h.c.liu@nrc.ca

    2008-09-24

    Nanostructures made of semiconductors, such as quantum wells and quantum dots (QD), are well known, and some have been incorporated in practical devices. Here we focus on novel structures made of QDs and related devices for terahertz (THz) generation. Their potential advantages, such as low threshold current density, high characteristic temperature, increased differential gain, etc, make QDs promising candidates for light emitting applications in the THz region. Our idea of using resonant tunneling through QDs is presented, and initial results on devices consisting of self-assembled InAs QDs in an undoped GaAs matrix, with a design incorporating a GaInNAs/GaAs short period superlattice, are discussed. Moreover, shallow impurities are also being explored for possible THz emission: the idea is based on the tunneling through bound states of individual donor or acceptor impurities in the quantum well. Initial results on devices having an AlGaAs/GaAs double-barrier resonant tunneling structure are discussed.

  1. Inorganic passivation and doping control in colloidal quantum dot photovoltaics

    KAUST Repository

    Hoogland, Sjoerd H.

    2012-01-01

    We discuss strategies to reduce midgap trap state densities in colloidal quantum dot films and requirements to control doping type and magnitude. We demonstrate that these improvements result in colloidal quantum dot solar cells with certified 7.0% efficiency.

  2. Low energy use at Vaestervik sports centre

    Energy Technology Data Exchange (ETDEWEB)

    2009-05-15

    Vaestervik, in south Sweden, has saved both energy and money since modern energy efficiency equipment was installed in its swimming pool and bowling alley. Energy use in the sports centre has so far fallen by around 830 MWh/year, and operating costs have been reduced by efficient heat recovery. Energy efficiency at the Vaestervik sports centre is a good example of how a local authority can save energy and money by installing modern equipment for ventilation and heat recovery in a facility with high energy consumption. The well-used sports centre, including a swimming pool and bowling alley, is in central Vaestervik. In 1999 the Municipality received grants from the local investment programme (LIP) to improve the facility's energy efficiency. An efficient ventilation system with a dehumidifier and heat exchanger was installed at the swimming pool, reducing the need to introduce cold air. In addition the bowling alley, which did not have heat recovery, was given a modern heat-recovery plant. - Lower operating costs due to efficient heat recovery. - Reduced energy use (electricity and district heating) for the plant at around 830 MWh/year. The modern and highly efficient units for heat recovery, dehumidification and heat exchange result in lower operating costs and reduced energy use, which means that the Municipality of Vaestervik saves energy and money. Installation at the swimming pool resulted in slightly higher air humidity, but a relative humidity of 60% is common in swimming pools and difficult to reduce without inconveniencing bathers. A new fan room installed in the roof contributed to higher than anticipated costs, but the financial and economic gains outweigh these. New frequency-controlled circulation pumps for the pool water were installed in 2007. They are to have occupancy control capability, giving a further improvement of energy saving and heat recovery

  3. Photoluminescence of carbon dots from mesoporous silica

    Science.gov (United States)

    Nelson, D. K.; Razbirin, B. S.; Starukhin, A. N.; Eurov, D. A.; Kurdyukov, D. A.; Stovpiaga, E. Yu; Golubev, V. G.

    2016-09-01

    Photophysical properties of carbon dots were investigated under various excitation conditions and over a wide temperature region - from room to liquid helium temperatures. The carbon dots (CDs) were synthesized using mesoporous silica particles as a reactor and (3-aminopropyl)triethoxysilane (APTES) as a precursor. The photoluminescence spectra of CDs exhibit a strong dependence on the excitation wavelength and demonstrate a significant inhomogeneous broadening. Lowering sample temperature reveals the doublet structure of the spectra, which is associated with the vibronic structure of radiative transitions. The vibration energy ∼1200 cm-1 is close to the energy of Csbnd O stretching vibration. Long-lived phosphorescence of carbon dots with its decay time ∼0.2 s at T = 80 K was observed. The fluorescence and phosphorescence spectra are shown to be spectrally separated. The long-lived component of the emission was ascribed to optically forbidden triplet-singlet transitions. The value of the singlet-triplet splitting was found to be about 0.3 eV. Photo-induced polarization of the luminescence of carbon dots was revealed. The degree of the linear polarization is dependent on the wavelengths of both excitation and emitted light. The effect indicates a hidden anisotropy of optical dipole transitions in the dots and demonstrates the loss of the dipole orientation during the electron energy relaxation.

  4. Biological Inspiration in Human Centred Robotics

    Institute of Scientific and Technical Information of China (English)

    HU Huo-sheng; LIU Jin-dong; Calderon Carlos A

    2004-01-01

    Human centred robotics (HCR) concerns with the development of various kinds of intelligent systems and robots that will be used in environments coexisting with humans. These systems and robots will be interactive and useful assistants/companions for people in different ages, situations, activities and environments in order to improve the quality of life. This paper presents the autors' current research work toward the development of advanced theory and technologies for HCR applications, based on inspiration from biological systems. More specifically, both bio-mimetic system modelling and robot learning by imitation are discussed respectively, and some preliminary results are demonstrated.

  5. Dynamics of B cells in germinal centres.

    Science.gov (United States)

    De Silva, Nilushi S; Klein, Ulf

    2015-03-01

    Humoral immunity depends on the germinal centre (GC) reaction during which somatically mutated high-affinity memory B cells and plasma cells are generated. Recent studies have uncovered crucial cues that are required for the formation and the maintenance of GCs and for the selection of high-affinity antibody mutants. In addition, it is now clear that these events are promoted by the dynamic movements of cells within and between GCs. These findings have resolved the complexities of the GC reaction in greater detail than ever before. This Review focuses on these recent advances and discusses their implications for the establishment of humoral immunity.

  6. The INTEGRAL science data centre (ISDC)

    DEFF Research Database (Denmark)

    Courvoisier, T.J.L.; Walter, Rasmus; Beckmann, V.;

    2003-01-01

    The INTEGRAL Science Data Centre (ISDC) provides the INTEGRAL data and means to analyse them to the scientific community. The ISDC runs a gamma ray burst alert system that provides the position of gamma ray bursts on the sky within seconds to the community. It operates a quick-look analysis...... of the data within few hours that detects new and unexpected sources as well as it monitors the instruments. The ISDC processes the data through a standard analysis the results of which are provided to the observers together with their data....

  7. LUMINESCENCE OF CADMIUM SULFIDE QUANTUM DOTS IN FLUOROPHOSPHATE GLASSES

    OpenAIRE

    Z. O. Lipatova; E. V. Kolobkova; V. A. Aseev

    2015-01-01

    Cadmium sulfide quantum dots are perspective materials in optics, medicine, biology and optoelectronics. Fluorophosphate glasses, doped with cadmium sulfide quantum dots, were examined in the paper. Heat treatment led to the formation of quantum dots with diameters equal to 2.8 nm, 3.0 nm and 3.8 nm. In view of such changes in the quantum dots size the fundamental absorption edge shift and the luminescence band are being displaced to the long wavelengths. Luminescence lifetime has been fou...

  8. Coherence and dephasing in self-assembled quantum dots

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher; Leosson, K.; Birkedal, Dan

    2003-01-01

    We measured dephasing times in InGaAl/As self-assembled quantum dots at low temperature using degenerate four-wave mixing. At 0K, the coherence time of the quantum dots is lifetime limited, whereas at finite temperatures pure dephasing by exciton-phonon interactions governs the quantum dot...... coherence. The inferred homogeneous line widths are significantly smaller than the line widths usually observed in the photoluminescence from single quantum dots indicating an additional inhomogeneours broadening mechanism in the latter....

  9. Quantum Dots and Their Multimodal Applications: A Review

    OpenAIRE

    Holloway, Paul H; Teng-Kuan Tseng; Lei Qian; Debasis Bera

    2010-01-01

    Semiconducting quantum dots, whose particle sizes are in the nanometer range, have very unusual properties. The quantum dots have band gaps that depend in a complicated fashion upon a number of factors, described in the article. Processing-structure-properties-performance relationships are reviewed for compound semiconducting quantum dots. Various methods for synthesizing these quantum dots are discussed, as well as their resulting properties. Quantum states and confinement of their excitons ...

  10. Filtering algorithm for dotted interferences

    Energy Technology Data Exchange (ETDEWEB)

    Osterloh, K., E-mail: kurt.osterloh@bam.de [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Buecherl, T.; Lierse von Gostomski, Ch. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany); Zscherpel, U.; Ewert, U. [Federal Institute for Materials Research and Testing (BAM), Division VIII.3, Radiological Methods, Unter den Eichen 87, 12205 Berlin (Germany); Bock, S. [Technische Universitaet Muenchen, Lehrstuhl fuer Radiochemie, Walther-Meissner-Str. 3, 85748 Garching (Germany)

    2011-09-21

    An algorithm has been developed to remove reliably dotted interferences impairing the perceptibility of objects within a radiographic image. This particularly is a major challenge encountered with neutron radiographs collected at the NECTAR facility, Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II): the resulting images are dominated by features resembling a snow flurry. These artefacts are caused by scattered neutrons, gamma radiation, cosmic radiation, etc. all hitting the detector CCD directly in spite of a sophisticated shielding. This makes such images rather useless for further direct evaluations. One approach to resolve this problem of these random effects would be to collect a vast number of single images, to combine them appropriately and to process them with common image filtering procedures. However, it has been shown that, e.g. median filtering, depending on the kernel size in the plane and/or the number of single shots to be combined, is either insufficient or tends to blur sharp lined structures. This inevitably makes a visually controlled processing image by image unavoidable. Particularly in tomographic studies, it would be by far too tedious to treat each single projection by this way. Alternatively, it would be not only more comfortable but also in many cases the only reasonable approach to filter a stack of images in a batch procedure to get rid of the disturbing interferences. The algorithm presented here meets all these requirements. It reliably frees the images from the snowy pattern described above without the loss of fine structures and without a general blurring of the image. It consists of an iterative, within a batch procedure parameter free filtering algorithm aiming to eliminate the often complex interfering artefacts while leaving the original information untouched as far as possible.

  11. Bright infrared LEDs based on colloidal quantum-dots

    KAUST Repository

    Sun, Liangfeng

    2013-01-01

    Record-brightness infrared LEDs based on colloidal quantum-dots have been achieved through control of the spacing between adjacent quantum-dots. By tuning the size of quantum-dots, the emission wavelengths can be tuned between 900nm and 1650nm. © 2013 Materials Research Society.

  12. AHE measurements of very thin films and nanosized dots

    NARCIS (Netherlands)

    Kikuchi, N.; Murillo, R.; Lodder, J.C.

    2005-01-01

    In this paper we present anomalous Hall effect analysis from very thin Co (0.5 nm) film, Co/Pt multilayers and large areas of nanosized dots as well as from a few magnetic dots having a diameter of 120 nm. The dot arrayis prepared from Co/Pt multilayer by using laser interference lithography (LIL) w

  13. Evidence for curvilinear interpolation from dot alignment judgements

    NARCIS (Netherlands)

    van Assen, MA; Vos, PG

    1999-01-01

    Visual interpolation between dots responsible for rectilinear versus curvilinear contour interpretation was examined with the psychophysical forced directional response (FDR) paradigm. Regular four-dot polygon segments, together with a target dot, were presented to the subjects for 150 ms. Subjects

  14. Toward structurally defined carbon dots as ultracompact fluorescent probes.

    Science.gov (United States)

    LeCroy, Gregory Ethan; Sonkar, Sumit Kumar; Yang, Fan; Veca, L Monica; Wang, Ping; Tackett, Kenneth N; Yu, Jing-Jiang; Vasile, Eugeniu; Qian, Haijun; Liu, Yamin; Luo, Pengju George; Sun, Ya-Ping

    2014-05-27

    There has been much discussion on the need to develop fluorescent quantum dots (QDs) as ultracompact probes, with overall size profiles comparable to those of the genetically encoded fluorescent tags. In the use of conventional semiconductor QDs for such a purpose, the beautifully displayed dependence of fluorescence color on the particle diameter becomes a limitation. More recently, carbon dots have emerged as a new platform of QD-like fluorescent nanomaterials. The optical absorption and fluorescence emissions in carbon dots are not bandgap in origin, different from those in conventional semiconductor QDs. The absence of any theoretically defined fluorescence color-dot size relationships in carbon dots may actually be exploited as a unique advantage in the size reduction toward having carbon dots serve as ultracompact QD-like fluorescence probes. Here we report on carbon dots of less than 5 nm in the overall dot diameter with the use of 2,2'-(ethylenedioxy)bis(ethylamine) (EDA) molecules for the carbon particle surface passivation. The EDA-carbon dots were found to be brightly fluorescent, especially over the spectral range of green fluorescent protein. These aqueous soluble smaller carbon dots also enabled more quantitative characterizations, including the use of solution-phase NMR techniques, and the results suggested that the dot structures were relatively simple and better-defined. The potential for these smaller carbon dots to serve as fluorescence probes of overall sizes comparable to those of fluorescent proteins is discussed.

  15. Coupling of single quantum dots to a photonic crystal waveguide

    DEFF Research Database (Denmark)

    Lund-Hansen, Toke; Stobbe, Søren; Julsgaard, Brian;

    . An alternative approach is to couple the quantum dot directly to the propagating mode of a photonic waveguide. We demonstrate the coupling of single quantum dots to a photonic crystal waveguide using time-resolved spontaneous emission measurements. A pronounced effect is seen in the decay rates of dots coupled...

  16. Charged-Exciton Complexes in Quantum Dots

    Institute of Scientific and Technical Information of China (English)

    XIE Wen-Fang

    2001-01-01

    It is known experimentally that stable charged-exciton complexes can exist in low-dimensional semiconductor nanostructures. Much less is known about the properties of such charged-exciton complexes since three-body problems are very difficult to be solved, even numerically. Here we introduce the correlated hyperspherical harmonics as basis functions to solve the hyperangular equation for negatively and positively charged excitons (trions) in a harmonic quantum dot. By using this method, we have calculated the energy spectra of the low-lying states of a charged exciton as a function of the radius of quantum dot. Based on symmetry analysis, the level crossover as the dot radius increases can be fully explained as the results of symmetry constraint.``

  17. Barrier Li Quantum Dots in Magnetic Fields

    Institute of Scientific and Technical Information of China (English)

    LIUYi-Min; LIXiao-Zhu; YANWen-Hong; BAOCheng-Guang

    2003-01-01

    The methods for the few-body system are introduced to investigate the states of the barrier Li quantum dots (QDs) in an arbitrary strength of magnetic field. The configuration, which consists of a positive ion located on the z-axis at a distaneed from the two-dimensional QD plane (the x-y plane) and three electrons in the dot plane bound by the positive ion, is called a barrier Li center. The system, which consists of three electrons in the dot plane bound by the ion,is called a barrier Li QD. The dependence of energy of the state of the barrier Li QD on an external magnetic field B and the distance d is obtained. The angular momentum L of the ground states is found to jump not only with the variation orB but also with d.

  18. Branch management into micropipeline joint dot

    Directory of Open Access Journals (Sweden)

    Dimitar Tyanev

    2011-11-01

    Full Text Available This paper considers problems related to hardware implementation of computational process with conditional jumps. Hardware refers to asynchronous pipeline organization at microoperational level. Exploration is dedicated to one of the tasks presented in (Tyanev, D., 2009 concerning to micropipeline controller design to control micropipeline stage into joint dot of branch algorithm. Joint dot is the point at which few preceding branches are combined. It appears inevitably into conditional jump structures and this is the reason for the actuality of its problem. Analysis of this new task is presented and request arbitration functioning principles are formulated for the incoming to joint dot requests. The arbiter is responsible for the fair choice on which depends steady peformance of separate pipeline brances. Paper also describes pipeline controller synthesis and analysis of its operation in two variants: about 2-phase and 4-phase data transfer protocol. The synthesized asynchronous arbiter scheme is invariant to the type of pipeline protocol.

  19. Angiogenic Profiling of Synthesized Carbon Quantum Dots.

    Science.gov (United States)

    Shereema, R M; Sruthi, T V; Kumar, V B Sameer; Rao, T P; Shankar, S Sharath

    2015-10-20

    A simple method was employed for the synthesis of green luminescent carbon quantum dots (CQDs) from styrene soot. The CQDs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, and Raman spectroscopy. The prepared carbon quantum dots did not show cellular toxicity and could successfully be used for labeling cells. We also evaluated the effects of carbon quantum dots on the process of angiogenesis. Results of a chorioallantoic membrane (CAM) assay revealed the significant decrease in the density of branched vessels after their treatment with CQDs. Further application of CQDs significantly downregulated the expression levels of pro-angiogenic growth factors like VEGF and FGF. Expression of VEGFR2 and levels of hemoglobin were also significantly lower in CAMs treated with CQDs, indicating that the CQDs inhibit angiogenesis. Data presented here also show that CQDs can selectively target cancer cells and therefore hold potential in the field of cancer therapy.

  20. Quantum Dots in Photonic Crystal Waveguides

    DEFF Research Database (Denmark)

    Sollner, Immo Nathanael

    This Thesis is focused on the study of quantum electrodynamics in photonic crystal waveguides. We investigate the interplay between a single quantum dot and the fundamental mode of the photonic crystal waveguide. We demonstrate experimental coupling eciencies for the spontaneous emission...... into the mode exceeding 98% for emitters spectrally close to the band-edge of the waveguide mode. In addition we illustrate the broadband nature of the underlying eects, by obtaining coupling eciencies above 90% for quantum dots detuned from the band edge by as far as 20nm. These values are in good agreement...... quantum-dot-waveguide coupling. Such a structure is ideally suited for a number of applications in quantum information processing and among others we propose an on-chip spin-photon interface, a single photon transistor, and a deterministic cNOT gate....

  1. WISB: Warwick Integrative Synthetic Biology Centre.

    Science.gov (United States)

    McCarthy, John

    2016-06-15

    Synthetic biology promises to create high-impact solutions to challenges in the areas of biotechnology, human/animal health, the environment, energy, materials and food security. Equally, synthetic biologists create tools and strategies that have the potential to help us answer important fundamental questions in biology. Warwick Integrative Synthetic Biology (WISB) pursues both of these mutually complementary 'build to apply' and 'build to understand' approaches. This is reflected in our research structure, in which a core theme on predictive biosystems engineering develops underpinning understanding as well as next-generation experimental/theoretical tools, and these are then incorporated into three applied themes in which we engineer biosynthetic pathways, microbial communities and microbial effector systems in plants. WISB takes a comprehensive approach to training, education and outreach. For example, WISB is a partner in the EPSRC/BBSRC-funded U.K. Doctoral Training Centre in synthetic biology, we have developed a new undergraduate module in the subject, and we have established five WISB Research Career Development Fellowships to support young group leaders. Research in Ethical, Legal and Societal Aspects (ELSA) of synthetic biology is embedded in our centre activities. WISB has been highly proactive in building an international research and training network that includes partners in Barcelona, Boston, Copenhagen, Madrid, Marburg, São Paulo, Tartu and Valencia.

  2. CMS tracker slides into centre stage

    CERN Multimedia

    2006-01-01

    As preparations for the magnet test and cosmic challenge get underway, a prototype tracker has been carefully inserted into the centre of CMS. The tracker, in its special platform, is slowly inserted into the centre of CMS. The CMS prototype tracker to be used for the magnet test and cosmic challenge coming up this summer has the same dimensions -2.5 m in diameter and 6 m in length- as the real one and tooling exactly like it. However, the support tube is only about 1% equipped, with 2 m2 of silicon detectors installed out of the total 200 m2. This is already more than any LEP experiment ever used and indicates the great care needed to be taken by engineers and technicians as these fragile detectors were installed and transported to Point 5. Sixteen thousand silicon detectors with a total of about 10 million strips will make up the full tracker. So far, 140 modules with about 100 000 strips have been implanted into the prototype tracker. These silicon strips will provide precision tracking for cosmic muon...

  3. ALICE opens its new nerve centre

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    Twenty-nine fully equipped and ergonomic workstations, one meeting area and 11 large format screens in a completely refurbished room: the ALICE Run Control Centre (ARC) implements the best and newest solutions for its shift workers and expert operators, including access for persons with reduced mobility and very soon a magic window for Point 2 visitors.   The ALICE Run Control Centre. “Our initial intention was just to optimise the old layout,” says Federico Ronchetti from Laboratori Nazionali di Frascati (Italy), a CERN scientific associate currently appointed as ALICE Run Coordinator and person in charge of the ALICE Consolidation Task Force. “However, during the review process, we carried out a study of all the existing control rooms at CERN and became aware we needed a radical change. Hence we started planning a complete redesign of the workspace.” Designed and equipped over many years, the old ALICE control room did not have enough space to fit al...

  4. KNMI Data Centre: Easy access for all

    Science.gov (United States)

    van de Vegte, John; Som de Cerff, Wim; Plieger, Maarten; de Vreede, Ernst; Sluiter, Raymond; Willem Noteboom, Jan; van der Neut, Ian; Verhoef, Hans; van Versendaal, Robert; van Binnendijk, Martin; Kalle, Henk; Knopper, Arthur; Spit, Jasper; Mastop, Joeri; Klos, Olaf; Calis, Gijs; Ha, Siu-Siu; van Moosel, Wim; Klein Ikkink, Henk-Jan; Tosun, Tuncay

    2013-04-01

    KNMI is the Dutch institute for weather, climate research and seismology. It disseminates weather information to the public at large, the government, aviation and the shipping industry in the interest of safety, the economy and a sustainable environment. To gain insight into long-term developments KNMI conducts research on climate change. Making the knowledge, data and information on hand at KNMI accessible is one core activity. A huge part of the KNMI information is from numerical models, insitu sensor networks and remote sensing satellites. This digital collection is mostly internal only available and is a collection of non searchable , non standardized file formats, lacking documentation and has no references to scientific publications. With the KNMI Data Centre (KDC) project these issues are tackled. In the project a user driven development approach with SCRUM was chosen to get maximum user involvement in a relative short development timeframe. Building on open standards and proven open source technology (which includes in-house developed software like ADAGUC WMS and Portal) resulted in a first release in December 2012 This presentation will focus on the aspects of KDC relating to its technical challenges, the development strategy and the initial usage results of the data centre.

  5. Glowing graphene quantum dots and carbon dots: properties, syntheses, and biological applications.

    Science.gov (United States)

    Zheng, Xin Ting; Ananthanarayanan, Arundithi; Luo, Kathy Qian; Chen, Peng

    2015-04-08

    The emerging graphene quantum dots (GQDs) and carbon dots (C-dots) have gained tremendous attention for their enormous potentials for biomedical applications, owing to their unique and tunable photoluminescence properties, exceptional physicochemical properties, high photostability, biocompatibility, and small size. This article aims to update the latest results in this rapidly evolving field and to provide critical insights to inspire more exciting developments. We comparatively review the properties and synthesis methods of these carbon nanodots and place emphasis on their biological (both fundamental and theranostic) applications.

  6. Resonant tunneling in graphene pseudomagnetic quantum dots.

    Science.gov (United States)

    Qi, Zenan; Bahamon, D A; Pereira, Vitor M; Park, Harold S; Campbell, D K; Neto, A H Castro

    2013-06-12

    Realistic relaxed configurations of triaxially strained graphene quantum dots are obtained from unbiased atomistic mechanical simulations. The local electronic structure and quantum transport characteristics of y-junctions based on such dots are studied, revealing that the quasi-uniform pseudomagnetic field induced by strain restricts transport to Landau level- and edge state-assisted resonant tunneling. Valley degeneracy is broken in the presence of an external field, allowing the selective filtering of the valley and chirality of the states assisting in the resonant tunneling. Asymmetric strain conditions can be explored to select the exit channel of the y-junction.

  7. Cadmium telluride quantum dots advances and applications

    CERN Document Server

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  8. Polymers in Carbon Dots: A Review

    Directory of Open Access Journals (Sweden)

    Yiqun Zhou

    2017-02-01

    Full Text Available Carbon dots (CDs have been widely studied since their discovery in 2004 as a green substitute of the traditional quantum dots due to their excellent photoluminescence (PL and high biocompatibility. Meanwhile, polymers have increasingly become an important component for both synthesis and modification of CDs to provide polymeric matrix and enhance their PL property. Furthermore, critical analysis of composites of CDs and polymers has not been available. Herein, in this review, we summarized the use of polymers in the synthesis and functionalization of CDs, and the applications of these CDs in various fields.

  9. Bilayer graphene quantum dot defined by topgates

    Energy Technology Data Exchange (ETDEWEB)

    Müller, André; Kaestner, Bernd; Hohls, Frank; Weimann, Thomas; Pierz, Klaus; Schumacher, Hans W., E-mail: hans.w.schumacher@ptb.de [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (Germany)

    2014-06-21

    We investigate the application of nanoscale topgates on exfoliated bilayer graphene to define quantum dot devices. At temperatures below 500 mK, the conductance underneath the grounded gates is suppressed, which we attribute to nearest neighbour hopping and strain-induced piezoelectric fields. The gate-layout can thus be used to define resistive regions by tuning into the corresponding temperature range. We use this method to define a quantum dot structure in bilayer graphene showing Coulomb blockade oscillations consistent with the gate layout.

  10. Mitigation of quantum dot cytotoxicity by microencapsulation.

    Directory of Open Access Journals (Sweden)

    Amelia Romoser

    Full Text Available When CdSe/ZnS-polyethyleneimine (PEI quantum dots (QDs are microencapsulated in polymeric microcapsules, human fibroblasts are protected from acute cytotoxic effects. Differences in cellular morphology, uptake, and viability were assessed after treatment with either microencapsulated or unencapsulated dots. Specifically, QDs contained in microcapsules terminated with polyethylene glycol (PEG mitigate contact with and uptake by cells, thus providing a tool to retain particle luminescence for applications such as extracellular sensing and imaging. The microcapsule serves as the "first line of defense" for containing the QDs. This enables the individual QD coating to be designed primarily to enhance the function of the biosensor.

  11. Spectroscopic characteristics of carbon dots (C-dots) derived from carbon fibers and conversion to sulfur-bridged C-dots nanosheets.

    Science.gov (United States)

    Vinci, John C; Ferrer, Ivonne M; Guterry, Nathan W; Colón, Verónica M; Destino, Joel F; Bright, Frank V; Colón, Luis A

    2015-09-01

    We synthesized sub-10 nm carbon nanoparticles (CNPs) consistent with photoluminescent carbon dots (C-dots) from carbon fiber starting material. The production of different C-dots fractions was monitored over seven days. During the course of the reaction, one fraction of C-dots species with relatively high photoluminescence was short-lived, emerging during the first hour of reaction but disappearing after one day of reaction. Isolation of this species during the first hour of the reaction was crucial to obtaining higher-luminescent C-dots species. When the reaction proceeded for one week, the appearance of larger nanostructures was observed over time, with lateral dimensions approaching 200 nm. The experimental evidence suggests that these larger species are formed from small C-dot nanoparticles bridged together by sulfur-based moieties between the C-dot edge groups, as if the C-dots polymerized by cross-linking the edge groups through sulfur bridges. Their size can be tailored by controlling the reaction time. Our results highlight the variety of CNP products, from sub-10 nm C-dots to ~200 nm sulfur-containing carbon nanostructures, that can be produced over time during the oxidation reaction of the graphenic starting material. Our work provides a clear understanding of when to stop the oxidation reaction during the top-down production of C-dots to obtain highly photoluminescent species or a target average particle size.

  12. Photoluminescence studies of single InGaAs quantum dots

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Jensen, Jacob Riis; Hvam, Jørn Märcher

    1999-01-01

    Semiconductor quantum dots are considered a promising material system for future optical devices and quantum computers. We have studied the low-temperature photoluminescence properties of single InGaAs quantum dots embedded in GaAs. The high spatial resolution required for resolving single dots...... to resolve luminescence lines from individual quantum dots, revealing an atomic-like spectrum of sharp transition lines. A parameter of fundamental importance is the intrinsic linewidth of these transitions. Using high-resolution spectroscopy we have determined the linewidth and investigated its dependence...... on temperature, which gives information about how the exciton confined to the quantum dot interacts with the surrounding lattice....

  13. The Influence of Formulating a Damping Solution on Dot Gain

    Directory of Open Access Journals (Sweden)

    Povilas Mikalainis

    2011-02-01

    Full Text Available Difference in dot gain using various additives to the damping solution was investigated on two offset web presses. Dot gain was measured using a densitometer and calculated considering CIE L*a*b* coordinates. It was found that while using a non alcohol additive instead of the alcohol one, dot gain became smaller and printing stability was lower. Changes in dot gain depend on the ink that may vary in colours. The influence of changes in dot gain on the colour was determined. Besides, it was found that differences in colour were unacceptable in many cases.Article in Lithuanian

  14. Photoluminescent carbon dots from 1,4-addition polymers.

    Science.gov (United States)

    Jiang, Zhiqiang; Nolan, Andrew; Walton, Jeffrey G A; Lilienkampf, Annamaria; Zhang, Rong; Bradley, Mark

    2014-08-25

    Photoluminescent carbon dots were synthesised directly by thermopyrolysis of 1,4-addition polymers, allowing precise control of their properties. The effect of polymer composition on the properties of the carbon dots was investigated by TEM, IR, XPS, elemental analysis and fluorescence analysis, with carbon dots synthesised from nitrogen-containing polymers showing the highest fluorescence. The carbon dots with high nitrogen content were observed to have strong fluorescence in the visible region, and culture with cells showed that the carbon dots were non-cytotoxic and readily taken up by three different cell lines.

  15. Electrically addressing a single self-assembled quantum dot

    CERN Document Server

    Ellis, D J P; Atkinson, P; Ritchie, D A; Shields, A J

    2006-01-01

    We report on the use of an aperture in an aluminum oxide layer to restrict current injection into a single self-assembled InAs quantum dot, from an ensemble of such dots within a large mesa. The insulating aperture is formed through the wet-oxidation of a layer of AlAs. Under photoluminescence we observe that only one quantum dot in the ensemble exhibits a Stark shift, and that the same single dot is visible under electroluminescence. Autocorrelation measurements performed on the electroluminescence confirm that we are observing emission from a single quantum dot.

  16. Sensitivity of quantum-dot semiconductor lasers to optical feedback.

    Science.gov (United States)

    O'Brien, D; Hegarty, S P; Huyet, G; Uskov, A V

    2004-05-15

    The sensitivity of quantum-dot semiconductor lasers to optical feedback is analyzed with a Lang-Kobayashi approach applied to a standard quantum-dot laser model. The carriers are injected into a quantum well and are captured by, or escape from, the quantum dots through either carrier-carrier or phonon-carrier interaction. Because of Pauli blocking, the capture rate into the dots depends on the carrier occupancy level in the dots. Here we show that different carrier capture dynamics lead to a strong modification of the damping of the relaxation oscillations. Regions of increased damping display reduced sensitivity to optical feedback even for a relatively large alpha factor.

  17. High-resolution photoluminescence studies of single semiconductor quantum dots

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Østergaard, John Erland; Jensen, Jacob Riis;

    2000-01-01

    Semiconductor quantum dots, especially those formed by self-organized growth, are considered a promising material system for future optical devices [1] and the optical properties of quantum dot ensembles have been investigated in detail over the past years. Recently, considerable interest has...... developed in the study of single quantum dots, characterized by sharp atomic-like transition lines revealing their zero-dimensional density of states. Substantial information about the fundamental properties of individual quantum dots, as well as their interactions with other dots and the host lattice, can...

  18. A study of the lunisolar secular resonance $2\\dot{\\omega}+\\dot{\\Omega}=0$

    CERN Document Server

    Celletti, Alessandra

    2016-01-01

    The dynamics of small bodies around the Earth has gained a renewed interest, since the awareness of the problems that space debris can cause in the nearby future. A relevant role in space debris is played by lunisolar secular resonances, which might contribute to an increase of the orbital elements, typically of the eccentricity. We concentrate our attention on the lunisolar secular resonance described by the relation $2\\dot{\\omega}+\\dot{\\Omega}=0$, where $\\omega$ and $\\Omega$ denote the argument of perigee and the longitude of the ascending node of the space debris. We introduce three different models with increasing complexity. We show that the growth in eccentricity, as observed in space debris located in the MEO region at the inclination about equal to $56^\\circ$, can be explained as a natural effect of the secular resonance $2\\dot{\\omega}+\\dot{\\Omega}=0$, while the chaotic variations of the orbital parameters are the result of interaction and overlapping of nearby resonances.

  19. Synthesis of CdSe quantum dots for quantum dot sensitized solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Neetu, E-mail: singh.neetu1985@gmail.com; Kapoor, Avinashi [Department of Electronic Science, University of Delhi South Campus, New Delhi-110 021 (India); Kumar, Vinod [Department of Physics, University of the Free State, Bloemfontein, ZA9300 (South Africa); Mehra, R. M. [School of Engineering and Technology, Sharda University, Greater Noida-201 306, U.P. (India)

    2014-04-24

    CdSe Quantum Dots (QDs) of size 0.85 nm were synthesized using chemical route. ZnO based Quantum Dot Sensitized Solar Cell (QDSSC) was fabricated using CdSe QDs as sensitizer. The Pre-synthesized QDs were found to be successfully adsorbed on front ZnO electrode and had potential to replace organic dyes in Dye Sensitized Solar Cells (DSSCs). The efficiency of QDSSC was obtained to be 2.06 % at AM 1.5.

  20. Children's Centre "3 in 1 - together"

    Science.gov (United States)

    Gancheva, Hristina

    2013-04-01

    "There are only two ways to life your live. One is as though nothing is a miracle. The other is as though everything is a miracle." Albert Einstein Children's Centre "3 in 1" is an extracurricular unit linked to the High School of Zlatartitsa, St. Cyril and St. Methodius, accomplished with the help of the municipality and many volunteers from the local community. With its activity it forms in children patriotic spirit, love for nature, active citizenship, and an impulse for a healthy life through communication with nature, saving the traditions and history, insurance of equality of the kids of the local five ethnicities and participation in activities in the sphere of science, art, sport and tourism. The educational work is mainly directed towards kids with difficulties with communication, hyperactivity, aggression, problems in their families, or those deprived of parental care. For a few years in the Children's Centre there have been clubs of interests: "Gardeners" - kids cultivate a garden. They plow, dig, plant, put in, irrigate and weed under the watch of Ms Stafka Nikolova, parents, and volunteers of the local community. The ecologically clean products - vegetables and fruits, kids use to cook delicious meals, sell, or give away. Weeds are also utilized; they are making herbarium out of them. "Cooks" - "What to have for lunch, when mom is out?". One can learn a lot of wonderful recipes from the club "Cooks". Products are own made, raised with love. In 2010, on the on the annual traditional holiday of the garden soup in Zlataritsa, the little cooks won third prize for making a delicious vegetable soup. On the same day, the 26 years old Nadezhda Savova, Cultural and Social Anthropology PhD in Princeton, founded the second community bakery in Bulgaria in Children's Centre "3 in1". Nadezhda Savova was declared traveler of 2012 by National Geographic. After the baking house in Gabrovo and Zlataritsa, Nadezhda also founded such projects in Sofia, Varna and Ruse

  1. Data communication at the CERN computer centre

    CERN Document Server

    Bruins, T; Pieters, R; Slettenhaar, Hendrik J; Van de Kerk, P

    1972-01-01

    The growing interest for on-line computer service and process control at CERN decentralises certain computer activities. Small process computers, remote batch stations and user terminals are to be backed by a powerful central computer. The present data network is principally star shaped. At the centre of it is a CDC 6600-6500 computer combination. It has a front end CDC 3100 computer with a Hewlett Packard 2116 as multiplexer. Some details about the fast parallel connections between the CDC 3100 and the HP 2116B are given in the paper, as well as descriptions of some computer simulation techniques used to test the present systems. Finally some plans on a future network are given. (12 refs).

  2. Learner-Centred Education in International Perspective

    Directory of Open Access Journals (Sweden)

    Michele Schweisfurth

    2013-04-01

    Full Text Available Abstract: This article provides an overview of Learner-Centred ducation (LCE as a travelling policy and outlines some of the arguments and pathways that have been used to fuel its travel. Despite the rich promises it offers and its proliferation as a global phenomenon and national policy, there is evidence that implementation and changes to classroom practice have proved to be problematic in many contexts. This seems particularly true in developing countries, and the article explores some of the reasons behind these perennial gaps. It concludes by arguing for the importance of both a birds-eye view and local understandings in researching and operationalising LCE, and suggests ways that the local and the global might be reconciled so that the promise of LCE is not lost in translation.

  3. MATERNAL MORTALITY IN A TERTIARY CARE CENTRE

    Directory of Open Access Journals (Sweden)

    Harpreet

    2013-06-01

    Full Text Available ABSTRACT: Maternal Mortality in A Tertiary Care Centre. OBJECTIVE: To study maternal mortality and the complications leading to maternal death. METHODS: A retrospective study of hospital record to study maternal mortality and its causes over 3 years from January 2010 to December 2012. RESULTS: There were a total of 58 maternal deaths out of 2823 live births giving a maternal mortality ratio of 2054.55 per one lakh live births. Unbooked and late referrals account for 77.58% of maternal deaths. The majority of deaths around 75.86% were in 20-30 years age group. Haemorrhage was the commonest causes of death (24.12% followed by sepsis (18.96% and pregnancy induced hypertension 15.51% Anemia contributed to the most common indirect cause of maternal morality. CONCLUSION: Haemorrhage, sepsis and pregnancy induced hypertension including eclampsia were the direct major causes of death. Anaemia and cardiac diseases were other indirect causes of death.

  4. Stimulated emission from NV centres in diamond

    CERN Document Server

    Jeske, Jan; McGuinness, Liam P; Reineck, Philip; Johnson, Brett C; McCallum, Jeffrey C; Jelezko, Fedor; Volz, Thomas; Cole, Jared H; Gibson, Brant C; Greentree, Andrew D

    2016-01-01

    Stimulated emission is the process fundamental to laser operation, thereby producing coherent photon output. Despite negatively-charged nitrogen-vacancy (NV$^-$) centres being discussed as a potential laser medium since the 1980's, there have been no definitive observations of stimulated emission from ensembles of NV$^-$ to date. Reasons for this lack of demonstration include the short excited state lifetime and the occurrence of photo-ionisation to the neutral charge state by light around the zero-phonon line. Here we show both theoretical and experimental evidence for stimulated emission from NV$^-$ states using light in the phonon-sidebands. Our system uses a continuous wave pump laser at 532 nm and a pulsed stimulating laser that is swept across the phononic sidebands of the NV$^-$. Optimal stimulated emission is demonstrated in the vicinity of the three-phonon line at 700 nm. Furthermore, we show the transition from stimulated emission to photoionisation as the stimulating laser wavelength is reduced fro...

  5. Project for a renewable energy research centre

    Directory of Open Access Journals (Sweden)

    Andrea Giachetta

    2011-04-01

    Full Text Available In Liguria, where sustainable approaches to the design, construction and management of buildings enjoy scant currency, the idea of a company from Milan (FERA s.r.l. setting up a research centre for studies into renewable energy resources, could well open up very interesting development opportunities.The project includes: environmental rehabilitation (restoration projects; strategies for the protection of water resources and waste management systems; passive and active solar systems (solar thermal and experiments with thermodynamic solar energy; hyperinsulation systems, passive cooling of buildings; use of natural materials; bio-climatic use of vegetation. The author describes the project content within the context of the multidisciplinary work that has gone into it.

  6. A novel POSS-coated quantum dot for biological application

    Directory of Open Access Journals (Sweden)

    Rizvi SB

    2012-08-01

    Full Text Available Sarwat B Rizvi,1 Lara Yildirimer,1 Shirin Ghaderi,1 Bala Ramesh,1 Alexander M Seifalian,1,2 Mo Keshtgar1,21UCL Centre for Nanotechnology and Regenerative Medicine, Division of Surgery and Interventional Science, University College London, United Kingdom; 2Royal Free Hampstead NHS Trust Hospital, London, United KingdomAbstract: Quantum dots (QDs are fluorescent semiconductor nanocrystals that have the potential for major advancements in the field of nanomedicine through their unique photophysical properties. They can potentially be used as fluorescent probes for various biomedical imaging applications, including cancer localization, detection of micrometastasis, image guided surgery, and targeted drug delivery. Their main limitation is toxicity, which requires a biologically compatible surface coating to shield the toxic core from the surrounding environment. However, this leads to an increase in QD size that may lead to problems of excretion and systemic sequestration. We describe a one pot synthesis, characterization, and in vitro cytotoxicity of a novel polyhedral oligomeric silsesquioxane (POSS-coated CdTe-cored QD using mercaptosuccinic acid (MSA and D-cysteine as stabilizing agents. Characterization was performed using transmission electron microscopy Fourier transform infrared spectroscopy, and photoluminescence studies. POSS-coated QDs demonstrated high colloidal stability and enhanced photostability on high degrees of ultraviolet (UV excitation compared to QDs coated with MSA and D-cysteine alone (P value < 0.05. In vitro toxicity studies showed that both POSS and MSA-QDs were significantly less toxic than ionized salts of Cd+2 and Te-2. Confocal microscopy confirmed high brightness of POSS-QDs in cells at both 1 and 24 hours, indicating that these QDs are rapidly taken up by cells and remain photostable in a biological environment. We therefore conclude that a POSS coating confers biological compatibility, photostability, and colloidal

  7. Communications Centre Model in Insurance Business

    Directory of Open Access Journals (Sweden)

    Danijel Bara

    2013-07-01

    Full Text Available The aim of this paper is to define a communications centre model in an insurance company that essentially has two objectives. The first objective is focused on providing quality support with the sales process thereby creating a strategic advantage over the competition while the second objective is focused on improving the link between internal organizational units whose behaviour can often render decision-making at all levels difficult. The function of sales is fundamental for an insurance company. Whether an insurance company will fulfil its basic function, which is transfer of risk from the insured party to the insurer who agrees tonreimburse incidental damages to the damaged party and distribute them among all members of the risk group on the principles of reciprocity and solidarity, depends on successful sales and billing (Andrijašević & Petranović, 1999. For an insurance company to operate successfully in a demanding market, it is necessary to meet the needs of potential clients who then must be at the centre of all the activities of the insurer. A satisfied policy holder, who is respected by the insurer as a partner, is a guarantee that the sales of insurance services will be successful and that the insured party will come back to the same insurance company. In the era of globalization and all-pervading new technologies and modes of communication, policy holders need to be able to communicate with insurance company employees. Quality communication is a good foundation for a sales conversation. A fast flow of all types of information within an organisation using a single communication module makes decision-making at all levels quicker and easier.

  8. Optical Properties of Quantum-Dot-Doped Liquid Scintillators

    CERN Document Server

    Aberle, C; Weiss, S; Winslow, L

    2013-01-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO.

  9. Collaborating at a distance: operations centres, tools, and trends

    Energy Technology Data Exchange (ETDEWEB)

    Gottschalk, Erik E.; /Fermilab

    2009-05-01

    Successful operation of the LHC and its experiments is crucial to the future of the worldwide high-energy physics program. Remote operations and monitoring centres have been established for the CMS experiment in several locations around the world. The development of remote centres began with the LHC{at}FNAL ROC and has evolved into a unified approach with distributed centres that are collectively referred to as 'CMS Centres Worldwide'. An overview of the development of remote centres for CMS will be presented, along with a synopsis of collaborative tools that are used in these centres today and trends in the development of remote operations capabilities for high-energy physics.

  10. Producing Quantum Dots by Spray Pyrolysis

    Science.gov (United States)

    Banger, Kulbinder; Jin, Michael H.; Hepp, Aloysius

    2006-01-01

    An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

  11. Enabling biomedical research with designer quantum dots

    NARCIS (Netherlands)

    Tomczak, N.; Janczewski, D.; Dorokhin, D.V.; Han, M-Y; Vancso, G.J.; Navarro, Melba; Planell, Josep A.

    2012-01-01

    Quantum Dots (QDs) are a new class of semiconductor nanoparticulate luminophores, which are actively researched for novel applications in biology and nanomedicine. In this review, the recent progress in the design and applications of QD labels for in vitro and in vivo imaging of cells is presented.

  12. Electron Scattering in Intrananotube Quantum Dots

    NARCIS (Netherlands)

    Buchs, G.; Bercioux, D.; Ruffieux, P.; Gröning, P.; Grabert, H.; Gröning, O.

    2009-01-01

    Intratube quantum dots showing particle-in-a-box-like states with level spacings up to 200 meV are realized in metallic single-walled carbon nanotubes by means of low dose medium energy Ar+ irradiation. Fourier-transform scanning tunneling spectroscopy compared to results of a Fabry-Perot electron r

  13. Quantum dot waveguides: ultrafast dynamics and applications

    DEFF Research Database (Denmark)

    Chen, Yaohui; Mørk, Jesper

    2009-01-01

    In this paper we analyze, based on numerical simulations, the dynamics of semiconductor devices incorporating quantum dots (QDs). In particular we emphasize the unique ultrafast carrier dynamics occurring between discrete QD bound states, and its influence on QD semiconductor optical amplifiers...... (SOAs). Also the possibility of realizing an all-optical regenerator by incorporating a QD absorber section in an amplifier structure is discussed....

  14. Amphoteric CdSe nanocrystalline quantum dots.

    Science.gov (United States)

    Islam, Mohammad A

    2008-06-25

    The nanocrystal quantum dot (NQD) charge states strongly influence their electrical transport properties in photovoltaic and electroluminescent devices, optical gains in NQD lasers, and the stability of the dots in thin films. We report a unique electrostatic nature of CdSe NQDs, studied by electrophoretic methods. When we submerged a pair of metal electrodes, in a parallel plate capacitor configuration, into a dilute solution of CdSe NQDs in hexane, and applied a DC voltage across the pair, thin films of CdSe NQDs were deposited on both the positive and the negative electrodes. Extensive characterizations including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR) and Raman studies revealed that the films on both the positive and the negative electrodes were identical in every respect, clearly indicating that: (1) a fraction (<1%) of the CdSe NQDs in free form in hexane solution are charged and, more importantly, (2) there are equal numbers of positive and negative CdSe NQDs in the hexane solution. Experiments also show that the number of deposited dots is at least an order of magnitude higher than the number of initially charged dots, indicating regeneration. We used simple thermodynamics to explain such amphoteric nature and the charging/regeneration of the CdSe NQDs.

  15. Coherent transport through interacting quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Hiltscher, Bastian

    2012-10-05

    The present thesis is composed of four different works. All deal with coherent transport through interacting quantum dots, which are tunnel-coupled to external leads. There a two main motivations for the use of quantum dots. First, they are an ideal device to study the influence of strong Coulomb repulsion, and second, their discrete energy levels can easily be tuned by external gate electrodes to create different transport regimes. The expression of coherence includes a very wide range of physical correlations and, therefore, the four works are basically independent of each other. Before motivating and introducing the different works in more detail, we remark that in all works a diagrammatic real-time perturbation theory is used. The fermionic degrees of freedom of the leads are traced out and the elements of the resulting reduced density matrix can be treated explicitly by means of a generalized master equation. How this equation is solved, depends on the details of the problem under consideration. In the first of the four works adiabatic pumping through an Aharonov-Bohm interferometer with a quantum dot embedded in each of the two arms is studied. In adiabatic pumping transport is generated by varying two system parameters periodically in time. We consider the two dot levels to be these two pumping parameters. Since they are located in different arms of the interferometer, pumping is a quantum mechanical effect purely relying on coherent superpositions of the dot states. It is very challenging to identify a quantum pumping mechanism in experiments, because a capacitive coupling of the gate electrodes to the leads may yield an undesired AC bias voltage, which is rectified by a time dependent conductance. Therefore, distinguishing features of these two transport mechanisms are required. We find that the dependence on the magnetic field is the key feature. While the pumped charge is an odd function of the magnetic flux, the rectified current is even, at least in

  16. Decoherence in Nearly-Isolated Quantum Dots

    DEFF Research Database (Denmark)

    Folk, J.; M. Marcus, C.; Harris jr, J.

    2000-01-01

    Decoherence in nearly-isolated GaAs quantum dots is investigated using the change in average Coulomb blockade peak height upon breaking time-reversal symmetry. The normalized change in average peak height approaches the predicted universal value of 1/4 at temperatures well below the single...

  17. System and method for making quantum dots

    KAUST Repository

    Bakr, Osman M.

    2015-05-28

    Embodiments of the present disclosure provide for methods of making quantum dots (QDs) (passivated or unpassivated) using a continuous flow process, systems for making QDs using a continuous flow process, and the like. In one or more embodiments, the QDs produced using embodiments of the present disclosure can be used in solar photovoltaic cells, bio-imaging, IR emitters, or LEDs.

  18. Saturating optical resonances in quantum dots

    Science.gov (United States)

    Nair, Selvakumar V.; Rustagi, K. C.

    Optical bistability in quantum dots, recently proposed by Chemla and Miller, is studied in a two-resonance model. We show that for such classical electromagnetic resonances the applicability of a two-resonance model is far more restrictive than for those in atoms.

  19. Single Molecule Applications of Quantum Dots

    DEFF Research Database (Denmark)

    Rasmussen, Thomas Elmelund; Jauffred, Liselotte; Brewer, Jonathan R.

    2013-01-01

    Fluorescent nanocrystals composed of semiconductor materials were first introduced for biological applications in the late 1990s. The focus of this review is to give a brief survey of biological applications of quantum dots (QDs) at the single QD sensitivity level. These are described as follows:...

  20. Carbon dots (C-dots) from cow manure with impressive subcellular selectivity tuned by simple chemical modification.

    Science.gov (United States)

    D'Angelis do E S Barbosa, Cintya; Corrêa, José R; Medeiros, Gisele A; Barreto, Gabrielle; Magalhães, Kelly G; de Oliveira, Aline L; Spencer, John; Rodrigues, Marcelo O; Neto, Brenno A D

    2015-03-23

    Improved cellular selectivity for nucleoli staining was achieved by simple chemical modification of carbon dots (C-dots) synthesized from waste carbon sources such as cow manure (or from glucose). The C-dots were characterized and functionalized (amine-passivated) with ethylenediamine, affording amide bonds that resulted in bright green fluorescence. The new modified C-dots were successfully applied as selective live-cell fluorescence imaging probes with impressive subcellular selectivity and the ability to selectively stain nucleoli in breast cancer cell lineages (MCF-7). The C-dots were also tested in four other cellular models and showed the same cellular selection in live-cell imaging experiments.

  1. VIA Ageing and Dementia, Research Centre, VIA University College, Denmark

    DEFF Research Database (Denmark)

    Munk, Karen Pallesgaard; Maibom, Kirsten

    2016-01-01

    New research environments are evolving in Denmark. Following a legislative change in 2013, the conditions for research in University Colleges have been improved. University Colleges (professionshøjskoler) includes the undergraduate-level educations such as nursing, occupational therapy and physio...... and physiotherapy and related research centres. The article describes such a research centre, namely VIA Ageing and Dementia, Research Centre, VIA University College, Denmark....

  2. Crystalline roof glazing - Westside shopping centre, Berne; Kristalline Dachverglasungen

    Energy Technology Data Exchange (ETDEWEB)

    Enkerli, W.

    2009-07-01

    This illustrated article takes a look at the new shopping and leisure centre on the western outskirts of Berne, Switzerland. In particular, the roof of this unusual building over the motorway with its sloping walls and zig-zag design is looked at. The centre's shopping mall, adventure baths and spa, a multiplex cinema, an old peoples' home and a hotel are briefly discussed, as is the embedding of the centre in its suburban environment. The roof construction with its crystalline skylights is examined and discussed in detail. The centre's building technical services are also briefly commented on.

  3. Optical power limiting in ensembles of colloidal Ag{sub 2}S quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Ovchinnikov, O V; Smirnov, M S; Perepelitsa, A S; Shatskikh, T S [Voronezh State University, Voronezh (Russian Federation); Shapiro, B I [M.V. Lomonosov Moscow State Academy of Fine Chemical Technology, Moscow (Russian Federation)

    2015-12-31

    The effect of power limiting for optical radiation at a wavelength of 660 nm with a pulse duration of 10 ms and operation threshold of 2.2 – 3.1 mJ cm{sup -2} is observed in ensembles of colloidal Ag{sub 2}S quantum dots (QDs). Using the z-scanning method in an open-aperture scheme it is found that the power is limited mainly due to reverse saturable absorption caused by two-photon optical transitions that involve energy levels of Ag{sub 2}S photoluminescence centres, related to structural impurity defects in colloidal Ag{sub 2}S QDs. At the same time, the z-scanning in a closed-aperture scheme demonstrates the formation of a thermal dynamic lens. (nonlinear optical phenomena)

  4. Entrapment in phospholipid vesicles quenches photoactivity of quantum dots

    Directory of Open Access Journals (Sweden)

    Generalov R

    2011-09-01

    Full Text Available Roman Generalov1,2, Simona Kavaliauskiene1, Sara Westrøm1, Wei Chen3, Solveig Kristensen2, Petras Juzenas11Department of Radiation Biology, Institute for Cancer Research, Norwegian Radium Hospital, Oslo University Hospital, Oslo, Norway; 2School of Pharmacy, University of Oslo, Oslo, Norway; 3Department of Physics, The University of Texas at Arlington, Arlington, TX, USAAbstract: Quantum dots have emerged with great promise for biological applications as fluorescent markers for immunostaining, labels for intracellular trafficking, and photosensitizers for photodynamic therapy. However, upon entry into a cell, quantum dots are trapped and their fluorescence is quenched in endocytic vesicles such as endosomes and lysosomes. In this study, the photophysical properties of quantum dots were investigated in liposomes as an in vitro vesicle model. Entrapment of quantum dots in liposomes decreases their fluorescence lifetime and intensity. Generation of free radicals by liposomal quantum dots is inhibited compared to that of free quantum dots. Nevertheless, quantum dot fluorescence lifetime and intensity increases due to photolysis of liposomes during irradiation. In addition, protein adsorption on the quantum dot surface and the acidic environment of vesicles also lead to quenching of quantum dot fluorescence, which reappears during irradiation. In conclusion, the in vitro model of phospholipid vesicles has demonstrated that those quantum dots that are fated to be entrapped in endocytic vesicles lose their fluorescence and ability to act as photosensitizers.Keywords: fluorescence lifetime, free radicals, liposomes, lipodots, reactive oxygen species

  5. Entrapment in phospholipid vesicles quenches photoactivity of quantum dots.

    Science.gov (United States)

    Generalov, Roman; Kavaliauskiene, Simona; Westrøm, Sara; Chen, Wei; Kristensen, Solveig; Juzenas, Petras

    2011-01-01

    Quantum dots have emerged with great promise for biological applications as fluorescent markers for immunostaining, labels for intracellular trafficking, and photosensitizers for photodynamic therapy. However, upon entry into a cell, quantum dots are trapped and their fluorescence is quenched in endocytic vesicles such as endosomes and lysosomes. In this study, the photophysical properties of quantum dots were investigated in liposomes as an in vitro vesicle model. Entrapment of quantum dots in liposomes decreases their fluorescence lifetime and intensity. Generation of free radicals by liposomal quantum dots is inhibited compared to that of free quantum dots. Nevertheless, quantum dot fluorescence lifetime and intensity increases due to photolysis of liposomes during irradiation. In addition, protein adsorption on the quantum dot surface and the acidic environment of vesicles also lead to quenching of quantum dot fluorescence, which reappears during irradiation. In conclusion, the in vitro model of phospholipid vesicles has demonstrated that those quantum dots that are fated to be entrapped in endocytic vesicles lose their fluorescence and ability to act as photosensitizers.

  6. Studies of silicon quantum dots prepared at different substrate temperatures

    Science.gov (United States)

    Al-Agel, Faisal A.; Suleiman, Jamal; Khan, Shamshad A.

    2017-03-01

    In this research work, we have synthesized silicon quantum dots at different substrate temperatures 193, 153 and 123 K at a fixed working pressure 5 Torr. of Argon gas. The structural studies of these silicon quantum dots have been undertaken using X-ray diffraction, Field Emission Scanning Electron Microscopy (FESEM) and High Resolution Transmission Electron Microscopy (HRTEM). The optical and electrical properties have been studied using UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Fluorescence spectroscopy and I-V measurement system. X-ray diffraction pattern of Si quantum dots prepared at different temperatures show the amorphous nature except for the quantum dots synthesized at 193 K which shows polycrystalline nature. FESEM images of samples suggest that the size of quantum dots varies from 2 to 8 nm. On the basis of UV-visible spectroscopy measurements, a direct band gap has been observed for Si quantum dots. FTIR spectra suggest that as-grown Si quantum dots are partially oxidized which is due exposure of as-prepared samples to air after taking out from the chamber. PL spectra of the synthesized silicon quantum dots show an intense peak at 444 nm, which may be attributed to the formation of Si quantum dots. Temperature dependence of dc conductivity suggests that the dc conductivity enhances exponentially by raising the temperature. On the basis above properties i.e. direct band gap, high absorption coefficient and high conductivity, these silicon quantum dots will be useful for the fabrication of solar cells.

  7. The Centres for Environment-friendly Energy Research (FME)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    High expectations for Norway's Centres for Environment-friendly Energy Research (FME).The FME centres address a broad range of areas, allcentral to developing the energy sector of the future. The activities of the eight centres established in 2009 focus on renewable energy, raising energy efficiency, energy planning, and carbon capture and storage (CCS). In 2011 three new FME centres were established which focus on social science-related energy research. The FME scheme is a direct follow-up of the broad-based political agreement on climate policy achieved in the Storting in January 2008, and of the national RandD Energi21 strategy submitted in February 2008 to the Ministry of Petroleum and Energy. In April 2008 the Research Council of Norway's Executive Board decided to launch a process to establish centres for environment-friendly energy research, and a funding announcement was issued that same year. In 2010 it was decided that additional FME centres would be established in the field of social science-related energy research. After a thorough assessment of each project (based on feasibility, scientific merit, potential to generate value creation and innovation, and composition of the consortium) eight applicants were selected to become FME centres in February 2009. A new call for proposals was issued in 2010, and three more centres were awarded FME status in February 2011. The objective of the FME scheme is to establish time-limited research centres which conduct concentrated, focused and long-term research of high international calibre in order to solve specific challenges in the energy sphere. The selected centres must exhibit higher goals, a longer-term perspective and a more concentrated focus than is required under other funding instruments for the same scientific area. The make-up of the centres is critical to achieving this objective. The centres bring together Norway's leading research institutions and key players in private enterprise, the

  8. Mass Segregation in the Galactic Centre

    CERN Document Server

    Hopman, Clovis

    2010-01-01

    Two-body energy exchange between stars orbiting massive black holes (MBHs) leads to the formation of a power-law density distribution n(r)~r^(-a) that diverges towards the MBH. For a single mass population, a=7/4 and the flow of stars is much less than N(centre (GC) is t_r ~2-3 * 10^(10) yr, a cusp should form in less than a Hubble time. The absence of a visible cusp of old stars in the GC poses a challenge to these models, ...

  9. Detecting pulsars in the Galactic centre

    CERN Document Server

    Rajwade, Kaustubh; Anderson, Loren

    2016-01-01

    Although high-sensitivity surveys have revealed a number of highly dispersed pulsars in the inner Galaxy, none have so far been found in the Galactic centre (GC) region, which we define to be within a projected distance of 1~pc from Sgr~A*. This null result is surprising given that several independent lines of evidence predict a sizeable population of neutron stars in the region. Here, we present a detailed analysis of both the canonical and millisecond pulsar populations in the GC and consider free-free absorption and multi-path scattering to be the two main sources of flux mitigation. We demonstrate the sensitivity limits of previous surveys are not sufficient to detect GC pulsar population, and investigate the optimum observing frequency for future surveys. Depending on the degree of scattering and free-free absorption in the GC, current surveys constrain the size of the potentially observable population (i.e. those beaming towards us) to be up to 50 canonical pulsars and 1430 millisecond pulsars. We find ...

  10. The Galactic Centre in the Far Infrared

    CERN Document Server

    Etxaluze, M; Tolls, V; Stark, A A; Gonzalez-Alfonso, E

    2011-01-01

    We analyse the far infrared dust emission from the Galactic Centre region, including the Circumnuclear Disk (CND) and other structures, using Herschel PACS and SPIRE photometric observations. These Herschel data are complemented by unpublished observations by the Infrared Space Observatory Long Wavelength Spectrometer (ISO LWS), which used parallel mode scans to obtain photometric images of the region with a larger beam than Herschel but with a complementary wavelength coverage and more frequent sampling with ten detectors observing at ten different wavelengths in the range from 46 to 180 \\mum, where the emission peaks. We also include data from the MSX at 21.3 \\mum for completeness. We model the combined ISO LWS continuum plus Herschel PACS and SPIRE photometric data toward the central 2 pc in Sgr A*, a region that includes the CND. We find that the FIR spectral energy distribution is best represented by a continuum that is the sum of three greybody curves from dust at temperatures of 90, 44.5, and 23 K. We ...

  11. Rockshire Care Centre, Rockshire Road, Ferrybank, Waterford.

    LENUS (Irish Health Repository)

    Bushe, Chris J

    2008-01-01

    BACKGROUND: Weight gain is commonly observed during psychotropic treatments for chronic forms of severe mental illness and is most rapid during the early treatment phases. All formats of behavioural weight intervention programmes have suggested that weight gain can be prevented or reversed in some patients. There is no data on these programmes in acutely unwell inpatients whom may be the major beneficiaries. METHODS: A modular behavioural intervention programme (Solutions for Wellness) used in SMI outpatients since 2002 in Ireland has been adapted for inpatient use. Preliminary data is reported from 5 centres in Ireland. RESULTS: In 47 inpatients the mean weight change was +0.26 kg (SD 2.02) with a median change of 0 kg. Mean follow-up was 23.7 (SD 21.6) days, and median 14 days (range 6-98 days). There was no difference in mean weight change in those patients involved for > 35 days compared with < 35 days (+0.26 kg; 0.25 kg; p = 0.5). Weight loss or maintenance was seen in 70% of patients. CONCLUSION: These preliminary data are supportive of the concept that acutely unwell inpatients with SMI may engage with a behavioural weight programme. Weight change observed contrasts with the significant weight gain often seen in most subjects. Further clinical trials are warranted.

  12. The LHC Physics Centre at CERN

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    As the LHC goes on line for its first exploration of the new high-energy frontier, CERN is also getting ready to enhance the support it provides for the analysis and interpretation of the emerging data.    The LHC Physics Centre at CERN (LPCC) has started up over the past couple of months, beginning with a series of initiatives ranging from Workshops to lectures for students. More details about the LPCC will be featured in a forthcoming Bulletin article. In the meantime, you can consult the LPCC web page, now available at http://cern.ch/lpcc. This offers the high energy physics community a portal to the LPCC's activities, as well as to useful resources, tools and information about the LHC physics programme, the progress of accelerator operations, relevant workshops and events around the world, and much more. The LPCC will shortly begin issuing a weekly bulletin of its own, distributed by e-mail. Members of the CERN physics community and subscribers to the CERN Bulletin will receive the ...

  13. The LHC Physics Centre at CERN

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Although raw physics data is produced at CERN, thanks to the GRID its analysis is performed in various institutes worldwide. In addition, workshops, conferences and meetings take place all over the world. The physicist community is decentralized, and CERN must continue to provide intellectual leadership. The LHC Physics Centre is the tool that will make this possible.   Until the early days of LEP, a large part of the scientific activity related to CERN’s experiments was strongly centered at the Laboratory. Few places had the infrastructure to host activities such as the working groups preparing the Yellow Reports, and the limited access to information in the pre-web era made CERN the natural place to learn what was happening in the field. “I remember the days when we, the theorists, would come to CERN just to read the most recent preprints, which were reaching CERN's Library before we could get them in our institutes”, says Michelangelo Mangano, a member of the Theo...

  14. The Charles Perkins Centre's Twins Research Node.

    Science.gov (United States)

    Ferreira, Lucas C; Craig, Jeffrey M; Hopper, John L; Carrick, Susan E

    2016-08-01

    Twins can help researchers disentangle the roles of genes from those of the environment on human traits, health, and diseases. To realize this potential, the Australian Twin Registry (ATR), University of Melbourne, and the Charles Perkins Centre (CPC), University of Sydney, established a collaboration to form the Twins Research Node, a highly interconnected research facility dedicated specifically to research involving twins. This collaboration aims to foster the adoption of twin designs as important tools for research in a range of health-related domains. The CPC hosted their Twins Research Node's launch seminar entitled 'Double the power of your research with twin studies', in which experienced twin researchers described how twin studies are supporting scientific discoveries and careers. The launch also featured twin pairs who have actively participated in research through the ATR. Researchers at the CPC were surveyed before the event to gauge their level of understanding and interest in utilizing twin research. This article describes the new Twins Research Node, discusses the survey's main results and reports on the launch seminar.

  15. Radio polarimetry of Galactic centre pulsars

    CERN Document Server

    Schnitzeler, D H F M; Ferrière, K; Kramer, M; Lee, K J; Noutsos, A; Shannon, R M

    2016-01-01

    To study the strength and structure of the magnetic field in the Galactic centre (GC) we measured Faraday rotation of the radio emission of pulsars which are seen towards the GC. Three of these pulsars have the largest rotation measures (RMs) observed in any Galactic object with the exception of Sgr A*. Their large dispersion measures, RMs and the large RM variation between these pulsars and other known objects in the GC implies that the pulsars lie in the GC and are not merely seen in projection towards the GC. The large RMs of these pulsars indicate large line-of-sight magnetic field components between ~ 16-33 microgauss; combined with recent model predictions for the strength of the magnetic field in the GC this implies that the large-scale magnetic field has a very small inclination angle with respect to the plane of the sky (~ 12 degrees). Foreground objects like the Radio Arc or possibly an ablated, ionized halo around the molecular cloud G0.11-0.11 could contribute to the large RMs of two of the pulsar...

  16. The Discharge Coefficient of a Centre-Pivot Roof Window

    DEFF Research Database (Denmark)

    Iqbal, Ahsan; Afshari, Alireza; Nielsen, Peter V.

    2012-01-01

    value of discharge coefficient is used. The constant value of discharge coefficient leads to deceptive airflow estimation in the cases of centre-pivot roof windows. The object of this paper is to study and evaluate the discharge coefficient of the centre pivot roof window. Focus is given...

  17. Importance of patient centred care for various patient groups.

    NARCIS (Netherlands)

    Rademakers, J.J.D.J.M.; Delnoij, D.M.J.; Boer, D. de

    2010-01-01

    Background: Though patient centred care is a somewhat ‘fuzzy’ concept, in general it is considered as something to strive for. However, preliminary evidence suggests that the importance of elements of patient-centred care (PCC), such as communication, information and shared decision making, may vary

  18. Opportunity Centred Learning: An Innovation in Enterprise Education?

    Science.gov (United States)

    Rae, David

    2003-01-01

    This paper describes an approach called opportunity centred learning that has been developed by the author and applied in the field of enterprise education. The relationship between opportunity centred learning and existing theory and practice in learning and education is outlined in comparison with problem-based learning and action learning, and…

  19. Low-Income Parents' Adult Interactions at Childcare Centres

    Science.gov (United States)

    Reid, Jeanne L.; Martin, Anne; Brooks-Gunn, Jeanne

    2017-01-01

    Little is known about the extent and nature of low-income parents' interactions with other parents and staff at childcare centres, despite the potential for these interactions to provide emotional, informational, and instrumental support. This study interviewed 51 parents at three childcare centres in low-income neighbourhoods in New York City.…

  20. Science Centres: A Resource for School and Community

    Science.gov (United States)

    Pilo, Miranda; Mantero, Alfonso; Marasco, Antonella

    2011-01-01

    We present a science centre established in Genoa on an agreement between Municipality of Genoa and Department of Physics of University of Genoa. The aim is to offer children, young people and community an opportunity to approach science in a playful way. The centre staffs guide the visitors through the exhibits, attracting their interests towards…